text:
\section{Introduction}

Duality suggests that even the spacetime signature is a relative concept that depends on the description \cite{Hull:1998ym, Hull:1998vg}.  The change of signature induced by duality transformations can be given a group theoretical interpretation in terms of the infinite-dimensional  Kac-Moody algebras $E_{11}$ or $E_{10}$ that have been conjectured to be ``hidden symmetries" of 11-dimensional supergravity or an appropriate extension \cite{Julia:1980gr,Julia:1982gx,Julia1,Nicolai:1991kx,Julia:1997cy,West:2001as,Damour:2000hv,Damour:2002cu}.  Weyl reflections in the exceptional root may change the spacetime signature.   In the orbit of the standard signature $(10,1, +)$ of $M$-theory (the one on which we shall focus in this paper) appear also the signatures $(9,2,-)$ (``$M^*$-theory"), $(6,5,+)$ (``$M'$-theory"), and the theories with reversed signatures $(1,10, -)$, $(2,9, +)$ and $(5,6, -)$ \cite{Englert:2003py,Keurentjes:2004bv,Keurentjes:2004xx,Englert:2004ph}.  In $(s,t, \pm)$, $s$ is the number of space directions, $t$ the number of time directions, and  $\pm$ refers to the sign of the kinetic term of the $3$ form. The analysis can be extended to other hidden symmetry algebras \cite{deBuyl:2005it}.  Multiple time physics has a long history (for a survey of two-time physics, see \cite{Bars:2000qm}) and has recently been shown to be connected with supergroup gauge theories and negative branes \cite{Dijkgraaf:2016lym}.

For all these reasons, it is of interest to explore solutions with exotic spacetime signatures in the context of $M$-theory. This is the object of this note. The analogues of the Freund Rubin solutions \cite{Freund:1980xh} have been already studied in \cite{Hull:1998fh}. We derive here the analogue of the Englert solution \cite{Englert:1982vs}.

It is known that the seven-sphere $S^7 \equiv SO(8)/SO(7)$ is one of the only spheres that are parallelizable \cite{Cartan1,Cartan2,Adams}.   If one allows pseudo-riemannian signatures, the family includes also the pseudo-sphere $S^{3,4}$  \cite{Wolf1, Wolf2},  which is the space of constant curvature  $SO(4,4)/SO(3,4)$ or space of unit split octonions  (see also \cite{Ranjbar})\footnote{Of course, the negative curvature spaces obtained by multiplying the metric by an overall minus sign, which are the pseudo-hyperbolic spaces $H^{0,7}$ and $H^{4,3}$  (see appendix \ref{app-notation} for conventions), also  enjoy this property.}.   Now, the seven-sphere plays an important role in eleven-dimensional supergravity \cite{Cremmer:1978km}, either through the Freund-Rubin solution where it leads to the $SO(8)$ gauged supergravity  \cite{deWit:1982bul} or through the Englert solution \cite{Englert:1982vs} which breaks the $SO(8)$ symmetry down to $Spin(7)$ \cite{Englert:1983jc} through the turning on of internal fluxes.   We show that there is an analogue of the Englert solution in $M'$-theory, which takes the form $AdS_4 \times S^{3,4}$.  Just as its original parent, this exotic form of the Englert solution is characterized by internal fluxes provided by a torsion that parallelizes $S^{3,4}$.  These internal fluxes break the $SO(4,4)$ symmetry of the pseudo-sphere $S^{3,4} \equiv SO(4,4)/SO(3,4)$ down to $Spin^+(3,4)$ (see Appendix \ref{App:pseudo} for information on the pseudo-sphere $S^{3,4}$, the split octonions and the relevant associated groups).

\section{Action principle and general ansatz}

\subsection{Action}

Our starting point is the bosonic action of $11$-dimensional supergravity with mixed signature \cite{Cremmer:1978km,Hull:1998ym, Hull:1998vg}, written as
\be
S=\f{1}{2\kappa^2} \int dx^{s+t} \mathcal{L},
\ee
where the Lagrangian $\mathcal{L}$ is
\be
\mathcal{L}=\sqrt{|g^{s+t}|} (R-\f{\eta}{24}F_{MNPQ}F^{MNPQ}-\f{2\sqrt{2}}{12^4}\f{1}{\sqrt{|g^{s+t}|}}\varepsilon^{M_1...M_{11}}F_{M_1...M_4}F_{M_5...M_8}A_{M_9...M_{11}}).
\ee
Here, $s+t$-dimensions ($s+t=11$) refers to $s$ spacelike directions and $t$ timelike directions and $F_{MNPQ}=4\partial_{[M}A_{NPQ]}$. The sign of $\eta$ is determined as\footnote{From the point of view of fermionic content of the theory, whenever $\eta=+1$ there exists a purely real representation of Clifford algebra and as a result spinors are Majorana. However, if $\eta=-1$ then there exists a purely imaginary representation of Clifford algebra and the spinors are pseudo-Majorana \cite{Kugo:1982bn}.}
\begin{align}
\eta &= +1\quad \textrm{if}\quad (s-t)\, \textrm{mod}\,8=1\quad\textrm{i.e. in dimensions}\quad 10+1, 6+5, 2+9,\\
\eta &= -1\quad \textrm{if}\quad (s-t)\, \textrm{mod}\,8=7\quad\textrm{i.e. in dimensions}\quad 1+10, 5+6, 9+2.
\end{align}
The equations of motion are
\begin{align}
R_{MN}-\f{1}{2}g_{MN}R &= -\f{\eta}{48}(g_{MN}F^2-8 F_{MPQR}F\indices{_N^{PQR}}),\label{EOM:var-wt-metric}\\
F\indices{^{MNPQ}_{;M}} &= \f{1}{\eta} \f{18\sqrt{2}}{12^4}\f{1}{\sqrt{|g^{11}|}} \varepsilon^{M_1...M_8 NPQ}F_{M_1...M_4}F_{M_5...M_8}\label{EOM:var-wt-3form}.
\end{align}

As we mentioned in the introduction, $M$-theory corresponds to $\eta = 1$, $(s,t)= (10,1)$, whereas $M^*$-theory corresponds to $\eta = -1$, $(s,t) = (9,2)$ and $M'$-theory corresponds to $\eta = 1$, $(s,t) = (6,5)$.  The equations of motion are invariant under the sign change of the metric $g_{MN} \rightarrow - g_{MN}$ accompanied by $\eta \rightarrow - \eta$ as well as $A_{MNP} \rightarrow  A_{MNP}$.  We recall that with our conventions,  $\epsilon^{01\cdots 10}$ changes sign since in the transformation $g_{MN} \rightarrow - g_{MN}$,  the parity of the number of time directions changes.  Because of this invariance, we concentrate on $M$-theory, $M^*$-theory and $M'$-theory,  leaving to the reader  the trivial task of deriving the solutions for the reversed signature theories corresponding to the other theories in the same duality orbit as ordinary supergravity.

\subsection{Product of constant curvature spaces}

We assume that the eleven-dimensional spacetime manifold (referred to as the ``ambient space" in the sequel) splits as the product of a four-dimensional manifold (``background spacetime") and a seven-dimensional manifold (``internal space")\footnote{We stress that the ``internal space" is thus in our terminology always the seven-dimensional manifold, independently of its curvature or signature.}.  The metric itself is a direct sum and splits into two parts, the metric on the internal space, and the one on the background spacetime. Capital Latin indices $M,N,...$ run over $0,...,10$. Small Latin indices $m,n,...$ are internal space indices and run over $4,...,10$.  Greek indices $\mu,\nu,...$ are background spacetime indices running over $0,1,2,3$. Notice that here $|g^{11}|$ is the absolute value of the determinant of the metric of the total space. We use the absolute value everywhere when needed for the determinant of the ambient, internal and background metrics since, a priori, there is no restriction on the signature of the aforementioned metrics.

We also assume that spacetime and the internal space are spaces of constant curvature, i.e., either a pseudo-sphere or a pseudo-hyperbolic space, with curvatures respectively given by
\begin{align}
 R_{mnrs} &= \f{a}{6} \left(g_{mr} g_{ns} - g_{ms} g_{nr} \right) \label{CC1},\\
R_{\mu \nu \rho \sigma} &= \f{b}{3} \left(g_{\mu \rho} g_{\nu \sigma} - g_{\mu \sigma} g_{\nu \rho} \right) \label{CC2},
\end{align}
where $a$ and $b$ are constants, which are positive for pseudo-spheres and negative for pseudo-hyperbolic spaces.  The conventions and notations used in this paper are collected in Appendix \ref{app-notation}.  This implies in particular
\begin{align}
R_{mn} &=a\, g_{mn},\label{Ricci-internal-space}\\
R_{\mu\nu} &=b \, g_{\mu\nu},\label{Ricci-spacetime}\\
R_{m\mu} &=0.\label{Ricci-mixed}
\end{align}

\section{Freund-Rubin type solutions}

We first derive the analogues of the Freund-Rubin solutions.  These were already considered in \cite{Hull:1998fh}.

The Freund-Rubin ansatz assumes in addition to the above conditions on the metric that the only $4$-form flux is in spacetime and reads explicitly:
\begin{align}
F^{\mu\nu\rho\sigma} &=\f{1}{\sqrt{|g^4|}}\f{f}{\sqrt{4!}} \varepsilon^{\mu\nu\rho\sigma},\label{flux-background}\\
F^{mPQR} &=0,
\end{align}
where $f$ is a constant. There is no internal flux.

Now, from \eqref{EOM:var-wt-metric} and  the ansatz,  one finds that
\begin{align}
R_{mn} &= (-\f{1}{3}) \f{\eta}{24}f^2 (-1)^{T'}  g_{mn},\\
R_{\mu\nu} &= (+\f{2}{3}) \f{\eta}{24}f^2 (-1)^{T'}  g_{\mu\nu},
\end{align}
where $T'$ is the number of timelike directions in the four-dimensional background spacetime metric.  We shall also introduce $T$ as the number of timelike directions in the internal space, so that $t$  (the number of timelike directions of the eleven-dimensional ambient space) is equal to $t = T + T'$. Comparing with \eqref{Ricci-internal-space} and \eqref{Ricci-spacetime}, we find
\be\label{FR-solution}
a=-\f{1}{3}\f{\eta}{24}f^2 (-1)^{T'}, \qquad b=-2a,
\ee
as in \cite{Hull:1998fh}.
For example, the standard Freund-Rubin solution is obtained by setting $\eta=+1$, $T'=1$.

The Freund-Rubin solutions constitute a one-parameter family of solutions.  One can take $f$ as the free parameter characterizing the solutions.  The curvature of the background spacetime and of the internal space are then determined by $f$ and are of opposite signs.  Note that they depend in fact on $f^2$ and so are invariant under $f \rightarrow -f$ as it should.

The sign of $a$ is easily seen to be always equal to  $(-1)^T$: for  $M$-theory and $M'$-theory, one has $\eta = 1$ and $(-1)^{T'} =-(-1)^T$ because $T+T' = t $ is odd.  This is also true for the reversed $M^*$-theory with signature $(2,9)$ and $\eta = 1$. For  $M^*$-theory, one has $\eta = -1$ but $t$ is now even and then $(-1)^{T'} =(-1)^T$.  The same is true for the reversed signature $M$- and $M'$-theories.  In all cases, the curvatures in the four-dimensional spacetime and in the internal manifold have opposite signs.

All Freund-Rubin solutions that can be obtained in this way are maximally supersymmetric \cite{Hull:1998fh}.

\section{Englert type solutions}

\subsection{Ansatz}

The Englert type solutions \cite{Englert:1982vs} can be considered as spontaneous breakings of the Freund-Rubin solutions  through non-vanishing expectation values for some of the  internal components of the $4$-form.  In other words there is now an internal flux which breaks completely the supersymmetry.

The Englert construction is available when the internal manifold is parallelizable.  This occurs when the internal  space of constant curvature is either the sphere $S^{7,0}$, corresponding to the original Englert solution \cite{Englert:1982vs}, or the pseudo-sphere $S^{3,4}$ (as well, of course, as the cases trivially obtained from these ones by an overall change of sign of the metric, corresponding to the pseudo-hyperbolic spaces $H^{0,7}$ and $H^{4,3}$).  All the other cases ($S^{6,1}$, $S^{5,2}$,  $H^{6,1}$ etc) are not parallelizable.

By matching the signatures, one easily sees that there are a priori four cases where the parallelizable seven-(pseudo-)spheres might appear for the theories in the time-duality orbit of $M$-theory.  These are
\begin{itemize}
\item Case 1: $M$-theory with spacetime manifold  $M^{3,1} \times S^{7,0}$,
\item Case 2: $M^*$-theory with spacetime manifold $M^{2,2} \times S^{7,0}$,
\item Case 3: $M'$-theory with spacetime manifold $M^{3,1} \times S^{3,4}$,
\item Case 4: reversed $M'$-theory with spacetime manifold $M^{2,2} \times S^{3,4}$,
\end{itemize}
as well as the reversed signature solutions.  Here, $M^{p,q}$ is a priori either $S^{p,q}$ or $H^{p,q}$, i.e., we leave the sign of the curvature of four-dimensional spacetime open. It will be determined by the equations.  We shall show that only cases 1 and 3 are actually compatible with the equations of motion and furthermore, that $M^{3,1}$ is then the anti-de Sitter space $H^{3,1}$.

We note that in all cases, the product $\eta (-1)^{T'}$, where $T'$ is the number of time directions in the four-dimensional background spacetime, is equal to $-1$,
$$\eta (-1)^{T'} = -1.$$
Indeed, one has $\eta = 1$ for cases 1 and 3 with $T'$ odd, and $\eta = -1$ for cases 2 and 4 but $T'$ is now even.  Furthermore, the curvature $a$ of the internal space is positive,
$$a >0,$$
and the number of time directions in the internal space is even ($a$ would of course be negative and $T$ odd for the reversed signature solutions.)

The Englert ansatz \cite{Englert:1982vs} consists in imposing the earlier conditions (\ref{CC1}), (\ref{CC2}),  (\ref{flux-background}) and
\be
F^{m\mu QR} =0. \label{flux-mixed}
\ee
The condition that the internal flux should vanish is, however, dropped, i.e., one allows $F^{mnpq}  \neq 0$.
In fact, one postulates instead
\be
F_{mnpq}=\lambda S_{[npq,m]} = \lambda S_{npq;m}. \label{flux-internal}
\ee
where $S_{npq}$ is one of the (metric compatible) torsions that parallelizes the internal space, i.e., such that when added to the Levi-Civita torsion-free connection,   the resulting connection is
flat (zero curvature).  In (\ref{flux-internal}),   $\lambda$ is a constant parameter.

As Cartan and Schouten showed \cite{Cartan1, Cartan2} (see also \cite{Englert:1982vs}), the torsions satisfy the following identities:
\begin{align}
S\indices{^{tr}_m} S_{trn} &=a\, g_{mn}, \label{Torsion101}\\
S\indices{_{tm}^r} S\indices{_{rn}^s} S\indices{_{sp}^t} &=\f{1}{2}a\, S_{mnp}, \label{Torsion102}\\
S_{npq;m} = S_{t[np}S\indices{^t_{q]m}} &= S_{[npq,m]}.  \label{Torsion103}
\end{align}
The parallelisms are respectively related to the octonion and split octonion algebras.  Because these algebras are non-associative, there are in each case two infinite classes, denoted $+$ and $-$.  We refer to \cite{Rooman} for useful information concerning  the $S^{7,0}$ sphere, easily extendable to $S^{3,4}$.   The corresponding torsions can be expressed in terms of the structure constants of the octonion or split-octonion algebras.   The invariance group at any given point of these $3$-forms is isomorphic to $G_2$ ($G^*_{2,2}$) in the Riemannian
(pseudo-Riemannian) case (see Appendix \ref{App:pseudo}). The fact that there are only two possible internal manifolds $S^{7,0}$ or $S^{3,4}$, and that $S^{6,1}$, $S^{5,2}$ etc are excluded,  is connected with the fact that there are only two real forms of the octonion algebra, and two real forms of the Lie algebra $g_2$.

Furthermore, one finds from (\ref{Torsion101})-(\ref{Torsion103}) that the
torsion $3$-forms are eigenfunctions of the (pseudo-)Laplace operator in $7$ dimensions,
\be
S\indices{_{npq;m}^{;m}}=-\f{2}{3} a \, S_{npq}. \label{Laplace}
\ee
One can also prove that the torsions are dual or anti-dual to their curvature \cite{Englert:1982vs},
\begin{align}
S^{mnp} &= \pm \sqrt{\frac{6}{a}}\frac{1}{4!}\frac{1}{\sqrt{|g^7|}}\varepsilon^{mnpqrst}S_{[rst,q]},\\
S_{mnp} &= \pm \sqrt{\frac{6}{a}}\frac{1}{4!}\sqrt{|g^7|}\varepsilon_{mnpqrst}S^{[rst,q]}.
\end{align}
where the $\pm$ sign depends on the $\pm$-class to which the torsion belongs.

With the above assumptions, the equation \eqref{EOM:var-wt-3form} for $F_{MNPQ}$ reduces to
\be\label{EOM-for-F-Englert}
F\indices{_{mnpq}^{;m}}= \f{(-1)^{T'}}{\eta} \f{f}{2(12)^{3/2}}\sqrt{|g^{7}|}\,\varepsilon_{rstunpq}F^{rstu},
\ee
 and is therefore solved in view of (\ref{flux-internal}) and (\ref{Laplace}) if we impose
\be\label{alpha-for-Englert-sol}
a = -\f{3}{4}\f{\eta}{24}f^2 (-1)^{T'} = \f{1}{32}f^2.
\ee
Given $a$, the two choices $f=\pm |f|= \pm \sqrt{32 a}$  correspond to the $+$ or $-$ parallelism, respectively.

Now, the equation \eqref{EOM:var-wt-metric} is equivalent to
\be
R_{MN} = -\f{\eta}{48}\left(\f23 g_{MN}F^2-8 F_{MPQR}F\indices{_N^{PQR}}\right),\label{EOM:var-wt-metric2}
\ee
Using the form of the fields obtained so far, the $(mn)$-components of \eqref{EOM:var-wt-metric2} read
\be
a = \frac49 a + \frac{1}{24}\frac{10}{9} \eta \lambda^2 a^2,
\ee
yielding
\be
\lambda^2 = \eta \frac{12 }{a}.
\ee
Since $a>0$, this equation has no (real) solution when $\eta = -1$, i.e., for cases 2 and 4 above.   When $\eta = 1$, this equation determines $\lambda$ in terms of $a$,
\be
\lambda = \pm \sqrt{\frac{12}{a}}.
\ee
The $(\mu \nu)$-components of \eqref{EOM:var-wt-metric2} determine then the radius of curvature $b$ of the four-dimensional background spacetime,
\be
b = - \frac53 a,
\ee
which is thus negative.  The four-dimensional background spacetime is therefore anti-de Sitter space $AdS_4 \equiv H^{3,1}$.

\subsection{Summary of solutions}

We thus see that there are only two cases among the cases listed above that can actually be realized (and the cases obtained by reversing the signature). These are
\begin{enumerate}
\item The Englert solution $ H^{3,1} \times S^{7,0}$ in $M$-theory.
\item The ``exotic" Englert solution  $H^{3,1} \times S^{3,4}$  in $M'$-theory.
\end{enumerate}
For all these solutions $\lambda^2=\f{12}{a}$ and $b=-\f{5}{3} a$, in consistency with \cite{Englert:1982vs}.

The parallelizable seven-sphere or seven-pseudo-sphere with internal torsion (fluxes) turned on is therefore a possible solution only in $M$-theory and $M'$-theory. $M^*$-theory does not accomodate such solutions.  Furthermore, the four-dimensional background spacetime is in both cases anti-de Sitter, with a single time.  There is no solution with two time directions in the four-dimensional background spacetime.

\subsection{Breaking of symmetry}
The Englert solution of $M$-theory breaks both supersymmetry and the $SO(8)$-symmetry of the seven-sphere down to $Spin(7)$ \cite{Englert:1983jc}.

A similar situation prevails in $M'$-theory.
The internal fluxes of the Englert-type solution break the $SO(4,4)$ symmetry of the pseudo-sphere $S^{3,4}$.  This is because the $4$-form $F_{mnpq}$ at any given point is not invariant under the full isotropy subgroup $SO(3,4)$.  It is only invariant under the subroup $G^*_{2,2}$ of the split octonions, since the torsion is determined by the structure constants of the split octonions.  Now, the pseudo-sphere is also equal to $Spin^+(3,4)/G^*_{2,2}$, where the group $Spin^+(3,4)$ is the connected component of $Spin(3,4)$ (see \cite{Kath:1996gm} and Appendix \ref{App:pseudo}).  This implies that the symmetry group of the $M'$-theory Englert solution is $Spin(3,4)$.  Similarly,  supersymmetry is broken.

\section{Conclusions and comments}

If one adopts the idea suggested by duality that the spacetime signature is a relative concept that depends on the description \cite{Hull:1998ym, Hull:1998vg}, it is natural to explore solutions of the exotic forms of $M$-theory in which there is more than one time direction.  We have shown in this note that an exotic version of the Englert solution exists in $M'$-theory, where the internal manifold is the parallelizable pseudo-sphere $S^{3,4}$. Through the non-vanishing internal fluxes, this solution breaks the $SO(4,4)$ symmetry of the pseudo-sphere down to $Spin^+(3,4)$.

It is interesting to note that $M$-theory and $M'$-theory have differences $s-t$ of the number of space directions minus the number of time directions that are equal modulo $8$ ($10-1 = 6-5$ modulo $8$).  Accordingly, they have spinor representations with similar properties. In fact, the spinor representations of $SO(7)$ and $SO(3,4)$  are in both cases $8$-dimensional and real.

The pseudo-sphere $S^{3,4}$ admits Killing spinors in terms of which one can express the torsions \cite{Kath:1996gm}.  Deformation by squashing of the pseudo-sphere can aso be contemplated.

\section*{Acknowledgments}
This work was partially supported by the ERC Advanced Grant ``High-Spin-Grav" and by FNRS-Belgium (convention FRFC PDR T.1025.14 and  convention IISN 4.4503.15).
 \break

\begin{appendix}
\section{Notation}\label{app-notation}
In this paper, we generally follow the notation of \cite{Freedman}.  For concreteness, we spell out the needed ones here:
\begin{itemize}
\item
$s$: Number of space directions of the ambient space manifold

\item
$t$: Number of time directions of the ambient space manifold

\item
$T$: Number of time directions of the internal manifold

\item
$T'$: Number of time directions of spacetime ``background" manifold

\item
$g_{MN} =\left( \begin{smallmatrix} g_{\mu\nu} & 0 \\  0 & g_{mn} \end{smallmatrix} \right)$: the metric on $11$ dimensional ambient space, $M,N=0,...,10$.

\item
$g_{mn}$: the metric on $7$ dimensional internal space, $m,n=4,...,10$.

\item
$g_{\mu\nu}$: the metric on $4$ dimensional spacetime, $\mu,\nu=0,...,3$.

\item
$F_{MNPQ}=4 \partial_{[M}A_{NPQ]}$.

\item
$\varepsilon_{M_1...M_{11}}$: the $11$ dimensional Levi-Civita antisymmetric covariant tensor density of rank $11$ and weight $-1$,  with $\varepsilon_{01234...}=+1$.

\item
$\varepsilon^{M_1...M_{11}}$: the $11$ dimensional Levi-Civita antisymmetric contravariant tensor density of rank $11$ and weight $+1$,  with $\varepsilon^{01234...}=(-1)^t$.  This choice is such that
$$\f{1}{\sqrt{\vert g^{11}\vert}}\varepsilon^{M_1 ... M_p}= \sqrt{\vert g^{11}\vert}  g^{M_1 N_1} g^{M_2 N_2}\cdots g^{M_{11} N_{11}} \varepsilon_{N_1 ... N_p},$$  where $g^{11}$ is the determinant of $g_{MN}$.

\item
\begin{align}
\varepsilon_{M_1...M_k M_{k+1}...M_{k+p}}\varepsilon^{M_1...M_k N_{k+1}...N_{k+p}}&=(-1)^t\, k!\,\delta^{N_{k+1}...N_{k+p}}_{M_{k+1}...M_{k+p}}\nonumber\\
&=(-1)^t\, k!\, p!\, \delta^{N_{k+1}}_{[M_{k+1}}\delta^{N_{k+2}}_{M_{k+2}}...\delta^{N_{k+p}}_{M_{k+p}]}.\nonumber
\end{align}

\item
$SO(p,q)$: the group of all transformations which leaves invariant the bilinear form $\eta_{p,q}=\sum_{i=1}^{p} dx_i^2 - \sum_{j=1}^{q} dx_j^2$.

\item
The pseudo-sphere $S^{p-1,q}=SO(p,q)/SO(p-1,q)$ ($p \geq 1, q \geq 0$) is a manifold with induced metric of  signature $(p-1,q)$ and  positive curvature.  In particular, $S^{p-1,0}$ is the standard $(p-1)$-sphere $S^{p-1}$.

\item
The  pseudo-hyperbolic space $H^{p,q-1}=SO(p,q)/SO(p,q-1)$ ($p \geq 0, q \geq 1$) is a manifold with induced metric of  signature $(p,q-1)$ and negative curvature.  While one removes a spacelike direction from the ambient space to get $S^{p-1,q}$, one removes a timelike direction for $H^{p, q-1}$ (see Appendix \ref{App:pseudo} for an explicit example).  In particular, $H^{p,0}$ is the standard hyperbolic space $H^p$ of dimension $p$.

\end{itemize}

\section{The pseudo-sphere $S^{3,4}$ and the split octonions}
\label{App:pseudo}

\subsection{The pseudo-sphere $S^{3,4}$ as a homogeneous space}
Let $\mathbb{R}^{4,4}$ be the $8$-dimensional real vector space endowed with the flat metric of mixed signature $(4,4)$,
\be
ds^{2}_{4,4} = \left(dx^1\right)^2 + \left(dx^2\right)^2 + \left(dx^3\right)^2 + \left(dx^4\right)^2 - \left(dy^1\right)^2 -\left(dy^2\right)^2 - \left(dy^3\right)^2 - \left(dy^4\right)^2.
\ee
We consider the  hypersurfaces:
\begin{eqnarray}
S^{3,4} &:& \left(x^1\right)^2 + \left(x^2\right)^2 + \left(x^3\right)^2 + \left(x^4\right)^2 - \left(y^1\right)^2 -\left(y^2\right)^2 - \left(y^3\right)^2 - \left(y^4\right)^2 = 1,\\
H^{4,3} &:& \left(x^1\right)^2 + \left(x^2\right)^2 + \left(x^3\right)^2 + \left(x^4\right)^2 - \left(y^1\right)^2 -\left(y^2\right)^2 - \left(y^3\right)^2 - \left(y^4\right)^2 = -1.
\end{eqnarray}
These are connected. Because the signature of the embedding space is symmetric for the exchange of the space and time directions, these hypersurfaces are clearly isomorphic.  The ``pseudo-sphere" $S^{3,4}$ has an induced metric with signature $(3,4)$ (three $+$ signs and four $-$ signs), while the ``pseudo-hyperbolic space" $H^{4,3}$ has an induced metric with signature $(4,3)$.   One goes from one to the other by an overall sign change of the metric.

The split group $O(4,4)$ and its subgroups $SO(4,4)$ and $SO^+(4,4)$ act transitively on $S^{3,4}$ and $H^{4,3}$.  The stability subgroups at a point are respectively $O(3,4)$, $SO(3,4)$ and $SO^+(3,4)$ for $S^{3,4}$, and $O(4,3)$, $SO(4,3)$ and $SO^+(4,3)$ for $H^{4,3}$.  Of course, the groups $O(3,4)$ and $O(4,3)$ (as well as $SO(3,4)$ and $SO(4,3)$, or  $SO^+(3,4)$ and $SO^+(4,3)$) are isomorphic, but we prefer to adopt different notations in each case to keep track of the signature of the metric.  Thus, the pseudosphere $S^{3,4}$ and pseudo-hyperbolic space $H^{4,3}$ are the homogeneous spaces:
\be
S^{3,4} = \frac{O(4,4)}{O(3,4)} = \frac{SO(4,4)}{SO(3,4)} =  \frac{SO^+(4,4)}{SO^+(3,4)},
\ee
and
\be
H^{4,3} = \frac{O(4,4)}{O(4,3)} = \frac{SO(4,4)}{SO(4,3)} =  \frac{SO^+(4,4)}{SO^+(4,3)}.
\ee

The pseudo-sphere $S^{3,4}$ and pseudo-hyperbolic space $H^{4,3}$ are not only homogeneous spaces, they are in fact maximally symmetric and hence spaces of constant curvature,
\be R_{mnpq} = K \left(g_{mp}g_{nq} - g_{mq}g_{np} \right),
\ee
with $K=1 >0$ for the pseudo-sphere $S^{3,4}$ and $K = -1 <0$ for the pseudo-hyperbolic space $H^{4,3}$,  in agreement with the observation that under an overall change of sign of the metric, the Riemann curvature changes sign but the product $\left(g_{mp}g_{nq} - g_{mq}g_{np} \right)$ does not, so that $K$ changes sign.

\subsection{Split octonions}

Let $a$ and $b$ be two quaternions, $a = a_0 + a_1 i + a_2 j + a_3 k$, $b = b_0 + b_1 i + b_2 j + b_3 k$ ($a_i, b_i \in \mathbb{R}$, $i^2 = j^2 = k^2 = -1$, $ij = k = - ji$ etc). The split octonions are pairs of quaternions $a +   b \ell $, where $\ell $ is a new element, for which one defines the product as
\be
(a +  b \ell) (c +  d \ell ) = ac + (\ell)^2 \bar{d} b +  (d a + b \bar{c}) \ell, \label{Product}
\ee
where
\be \ell^2 = +1,
\ee
instead of $-1$ as for the standard octonions.  In (\ref{Product}), the overbar denotes quaternionic conjugation, $\bar{d} = d_0 - d_1 i - d_2 j - d_3 k$.

Setting $e_0 = 1$, $e_1 = i$, $e_2 = j$, $e_3 = k$, $e_4 = \ell$, $e_5 = i \ell$, $e_6 = j \ell$ and $e_7 = k \ell$, one gets the same products $e_i e_j$ as for the standard octonions, except when two $\ell$'s are involved, in which case one gets an additional minus sign. For instance $e_1 e_4 = e_5$ as for octonions, but $e_4 e_5 = -e_1$ while it is $+e_1$ for standard octonions.  Similarly, $e_4^2 = e_5^2 = e_6^2 = e_7^2 = +1$ instead of $-1$.

One defines octonionic conjugation for a general split octonion
\be
x =  x^0 e_0 + x^1 e_1 + x^2 e_2 + x^3 e_3 + x^4 e_4 + x^5 e_5 + x^6 e_6 + x^7 e_7 , \; \; \; x^i \in \mathbb{R}
\ee
as
\be
\bar{x}  =  x^0 e_0 - x^1 e_1 - x^2 e_2 - x^3 e_3 - x^4 e_4 - x^5 e_5 - x^6 e_6 - x^7 e_7.
\ee
One has
\be
\overline{xy} = \bar{y} \bar{x},
\ee
and of course $\overline{\bar{x}} = x$.
A scalar product can then be introduced as
\be
(x,y) = \frac12 \left( x \bar{y}+ y \bar{x} \right) = \frac12 \left( \bar{x} y+ \bar{y} x \right).
\ee
Explicitly, one finds
\begin{eqnarray}
(x,y) &=& x^0 y^0 + x^1 y^1 + x^2 y^2 + x^3 y^3 - x^4 y^4 - x^5 y^5 - x^6 y^6 - x^7 y^7 \\
&=& x^0 y^0 + \sum_{i=1}^7 \eta_{ij} x^i y^j,
\end{eqnarray}
where $\eta_{ij}$ is the flat metric with signature $(3,4)$.

An octonion is pure imaginary if $\bar{x} = - x$.  The unit octonions $e_i$ are pure imaginary.  The pure imaginary condition is equivalent to  $(e_0, x) = 0$.

One can rewrite the product of the unit octonions $e_i$ as
\be
e_i e_j = - \eta_{ij} e_0+ a_{ij}^{\; \; \; k} e_k,
\ee
where the structure constants $a_{ij}^{\; \; \; k}$ are such that the $a_{ijk} \equiv a_{ij}^{\; \; \; m} \eta_{km}$ are completely antisymmetric in $(i,j,k)$.   The tensor $a_{ijk}$ has value $+1$ for $(ijk) = (123)$, $(154)$, $(167)$, $(264)$, $(275)$, $(374)$ and $(356)$ (and cyclic permutations).

The squared norm $N(x) \equiv (x,x)$ of $x$ reads
\begin{eqnarray}
N(x)  &=& \left( x^0 \right)^2 +  \left( x^1 \right)^2 +  \left( x^2 \right)^2 +  \left( x^3 \right)^2 -  \left( x^4 \right)^2 - \left( x^5 \right)^2 -  \left( x^6 \right)^2 -  \left( x^7 \right)^2 \\
&=& \eta_{\lambda \mu} x^\lambda x^\mu, \; \; \; \; (\lambda, \mu = 0, 1, \cdots, 7)
\end{eqnarray}
where $\eta_{\lambda \mu}$ is the flat metric with signature $(4,4)$.  The split octonions form a composition algebra, i.e.,
\be
N(xy) = N(x) N(y).
\ee

Just as the standard octonions, the split octonions do not form an associative algebra.  However, in the same way as for the standard octonions, the associator $[x,y,z]$ of three split octonions $x$, $y$, $z$, defined through
\be
[x,y,z] = (xy)z - x(yz),
\ee
is an alternating function of $x$, $y$, $z$, i.e.
\be
[x,y,z] = [x,y,z] = [z,x,y] = - [y,x,z] = -[x,z,y] = -[z,y,x].
\ee

More information on the split octonions can be found in \cite{Gunaydin:1973rs,BaezHuerta}.

\subsection{Parallelizations of the pseudo-sphere $S^{3,4}$}

There exist two infinite families of parallelizations of the pseudo-sphere $S^{3,4}$.  We first start by describing one of these parallelizations.

Consider the pseudo-sphere $S^{3,4}$ of unit octonions, $x \in S^{3,4} \Leftrightarrow N(x) =1$.  The real number $1$ is the ``North pole".  The tangent space at the North pole can be identified with the seven-dimensional vector space of imaginary octonions.  A Lorentz basis of this tangent space is given by the $e_i$'s.  Let  $x \in S^{3,4}$.   Right multiplication by $x$ maps  the North pole to $x$, and the tangent space at the North pole to the tangent space at $x$.  Indeed, the vectors $e_i$ at the North pole are mapped on $t^+_i  \equiv e_i x$.  One has:
\be
(t^+_i, x) = 0, \; \; \; (t^+_i, t^+_j) = \eta_{ij}.
\ee
The first equality expresses that the seven octonions $t^+_i$, viewed as vector in $\mathbb{R}^{4,4}$ are orthogonal to $x$ and hence tangent to the pseudo-sphere $S^{3,4}$ at $x$.  The second equality expresses that the $t^+_i$'s form a Lorentz basis of that tangent space.

We have thus defined at each point of the pseudo-sphere $S^{3,4}$ a Lorentz basis of the tangent space.  This provides an absolute parallelism for $S^{3,4}$. The tangent vector at $x$ parallel to the tangent vector $e_i$ at $1$ is the vector $e_i x$ obtained by right multiplication with $x$.  The corresponding parallel transport preserves the metric of $S^{3,4}$ and its geodesics can be verified to coincide with those defined by the metric. The parallelization defined by $\{t^+_i\}$ is thus consistent with the metric.

Similarly, left multiplication also defines a parallelization of $S^{3,4}$ that maps the tangent basis $\{e_i\}$ at $1$ on the tangent basis $\{t_i^- \equiv x e_i\}$ at $x$.  The two parallelisms are inequivalent since the tangent vectors $t^+_i$ and $t_i^-$   coincide only at the North pole and at the ``South pole" $-1$.

Yet other parallelizations can be defined by using a reference point on  $S^{3,4}$ different from unity.  More precisely, let $\alpha \in S^{3,4}$.  One goes from $\alpha$ to $x$ by multiplying $\alpha$ by $\bar{\alpha} x$, $\alpha (\bar{\alpha } x) = x$.  One defines the tangent vector $^{(\alpha)} t_i^+$ at $x$ parallel to the tangent vector $e_i \alpha$ at $\alpha$ through right multiplication by the octonion $\bar{\alpha} x$ that connects $\alpha$ to $x$, $^{(\alpha)} t_i^+ = (e_i \alpha) (\bar{\alpha} x)$.  The tangent vectors $^{(\alpha)} t_i^+$ and $t^+_i$ at $x$ do not coincide because octonionic multiplication is not associative.  A similiar construction yields the parallelism $^{(\alpha)} t_i^- = (x \bar{\alpha})(\alpha e_i)$.

Because the families of parallelisms given by the above construction are consistent with the metric, the corresponding torsion tensors obey the equations (\ref{Torsion101})-(\ref{Torsion103}) given above \cite{Cartan1,Cartan2,Wolf1,Wolf2}.

The parallelisms of $S^{3,4}$ are related to the split octonions in the same way as the parallelisms of the seven-sphere are related to the standard octonions.  For that reason, the reader can find more information on the parallelisms of $S^{3,4}$ in the literature on the parallelisms of the seven-sphere.  A reference that we have found useful is \cite{Rooman}.

\section{$Spin^+(3,4)$ and $G_{2,2}^*$}

The complex Lie agebra $g_2$ possesses two real forms, the compact one and the split one.  To the compact real form corresponds the unique compact group $G_2$.  To the split real form correspond the simply connected non compact group $G_{2,2}$ with center $\mathbb{Z}_2$ and the quotient $G_{2,2}^* \equiv \frac{G_{2,2}}{\mathbb{Z}_2} $ (``adjoint real form") which has trivial center (and is not simply connected). The group  $G_{2,2}^*$ is the automorphism group of the split octonions.

The group $Spin(7)$ is well-known to have a transitive action on the seven-sphere $S^7$, with isotropy group $G_2$.  Similarly, the group $Spin^+(3,4)$ (connected component of $Spin(3,4)$) has a transitive action on the pseudo-sphere $S^{3,4}$ with isotropy group $G_{2,2}^*$ \cite{Kath:1996gm}.  We can thus also identify $S^{3,4}$ with the homogeneous space $Spin^+(3,4) /G_{2,2}^*$,
\be
S^{3,4} \simeq \frac{Spin^+(3,4)}{G_{2,2}^*}
\ee

\end{appendix}

redpajama_set_name: RedPajamaArXiv


Cakes are just one of one of the most searched for Valentine's Day presents online. It's noticeable that you would certainly would like to decide on an on-line present establishment for they are comfortable as well as effortlessly obtainable. An additional factor is that via on-line purchasing pies, you could reach your loved ones living throughout India as well as the UNITED STATE. As well as suppose just what? The delivery location is cost-free also! So we recommend you share the preference of love this Valentine's day via an on-line pastry shop. You'll have a minimum of 3 groups to pick from. Allow's take a more detailed look.
There's a wonderful screen of Normal Valentine Cakes on on-line pastry shops. Chocolate Pudding, Black Woodland, Valentine Red Velvet Cake Photo, Chocolate Fudge Chocolate Truffle are few of one of the most favored pies for Valentine's Day. Generally, it is the flavour of chocolate that's one of the most enticing. Or else, these pies have essentially the very same elements. They are, largely, baked with eggs. The sponge pies are saturated in Kirsch, sprayed with delightful dark chocolate, covered in a light valentine chocolate as well as a smooth chocolate polish, ornamented by attractive Belgian chocolate swirls, iced with wet chocolate truffle, layered with chocolate dessert, naturally laid total by the gold coin chocolates as well as some even more such approaches to make your mouth water as well as the day added unique.
Valentine Red Velvet Cake Photo was added at April 10, 2015. Hundreds of our reader has already save this stock images to their computer.
This images Labelled as: Valentine Cakes, bakerella cake pops subject, in conjunction with cake decorating ideas topic, as well as cake pop ideas subject, . You can also download the images under Valentine Red Velvet Cake Photo articles for free. Help us by share this images to your family.
Valentine Red Velvet Cake Photo was submitted by Sabhila Reynold at April 10, 2015 at 9:45pm.
Little Debbie Be My Valentine Vanilla Cakes is pretty image related with Valentine Cakes, upload on June 5, 2015 and has size 1024 x 768 px.
Dairy Queen Valentine Cakes Idea is lovely image under Valentine Cakes, entry on April 13, 2015 and has size 1024 x 709 px.
Valentine Cake House Birthday Cakes is cool picture inside Birthday Cake, posted on June 2, 2015 and has size 1024 x 1365 px.
Christmas Chocolate Covered Pretzel Rods is awesome picture related with Valentine Cakes, upload on June 4, 2015 and has size 620 x 679 px.


Dress up the meeting room with our classy new T-Leg Design. Same waterproof and virtually indestructible top as our standard R-Series seminar & folding tables. This seminar table h as a single 1x2 steel upright and our knife-lock folding mechanism for unobstructed leg room. All T-Leg tables have a 1x2 steel pedestal with nylon glides and fold easily for storage. 29" height, 18" x 72", Mocha granite with black frame.


text:
City of Elk Grove » Government » City Government » City Council » Council Member Appointments » District 3
Kevin Spease
Term: 12/2020 to 12/2024
Email Kevin
Kevin grew up in Elk Grove and after graduating from Christian Brothers High School, Kevin made the decision to serve his country. He enlisted in the California Army National Guard and later, the United States Air Force.
After 14 years of service to the nation living in several countries abroad, Kevin was honorably discharged and returned to Elk Grove to start a small business with his wife: ISSE Services. As President & CEO, Kevin has led the cyber security company as it has grown in Elk Grove and Utah.
As a small business owner, Kevin understands the challenges Californians have getting a business started and making it profitable. As the Chair of the Elk Grove Chamber of Commerce, Kevin has actively advocated at the California Assembly and Senate to improve legislation for small businesses.
Active as a leader in the community, Kevin has served as an Elk Grove Planning Commissioner and president of the Rotary Club of Laguna Sunrise. Kevin also volunteers his time with charities and non-profits, including the Elk Grove Food Bank, and the Sacramento County Veterans Treatment Court, where he helps veterans through legal issues related to PTSD. For his service to Elk Grove, in 2018 Kevin was honored by the Elk Grove Chamber as the Citizen of the Year.
Kevin graduated from the Community College of the Air Force with an Associate in Applied Science in Munitions Systems Technology, and from the University of Phoenix with a BS and MBA in business.
Kevin has been married to his wife Angela for over 30 years, and together they have a son, Jeremy and a Labradoodle, Indie Freckles.
District 3 Map
Locate your district

redpajama_set_name: RedPajamaCommonCrawl


text:
All Games Database
Picklemoose's Blog
Picklemoose's Blog
/ Wingspan Review (Physical Game)
Wingspan Review (Physical Game)
By	Chris	/	August 9, 2019
This is Picklemoose's Blog. A small section of Pixelated Cardboard dedicated to topics outside of digital board game ports. Posts here will be less formal & cover a range of topics.
Wingspan! Birds! Eggs! Components! Hype! Wingspan! If you pay any attention to the board game world, you've heard of Wingspan. It is the adorably-theme engine builder from Stonemaier games. It comes with ridiculously nice components, including linen rulebooks, because why not? It was released early this year and received a bunch of hype. That hype led to the inevitable "overhyped" backlash, but then it won the Kennerspiel des Jahres award (given to the "hobbyist game of the year"), ensuring that it will live on for a long time. Or not, if you look at the history, but do any games live on for a long time anymore in our overly consumerist culture? That's another topic.
So, Wingspan! What is it? You collect from a pile of 170 unique bird cards and use food resources to lure them into your wildlife reserve. Once there, birds provide one of four different abilities: an ability each time you activate it, an ability that can activate when an opponent does something, an ability that activates when you play it, or nothing at all. Birds also provide points and most provide nice, comfortable nests on which you can lay beautiful pastel eggs on to receive a point at the end of the game. Or use them to pay for more birds, because theme?
The game plays over four rounds with points being scored based on birds played, eggs gained, secret goals earned, open goals achieved, and eating giant piles of smaller prey. Wait, what? Yes, predators are in the game and there are one of the most fun aspects. Get a giant hawk and, when activates, you will be able to draw a card from the deck and if the bird drawn is small enough, you successfully found your bird's lunch and you get to tuck the card under said bird for a point at the end of the game. Circle of life! Those open goals are the most direct conflict the game contains, as you can play where the player who does the best at some goal gets the most points. There is a flip side to that sheet which is less conflict-heavy. Some other birds let you tuck cards in different ways or gather food onto them for end game points. The important takeaway from this paragraph is that you can hunt birds, the second, far less important, takeaway is that the game has a bunch of avenues to points which is always a great sign for replayability.
It's an engine builder. You start stacking those powerful "when activated" abilities in rows next to each other and suddenly you are laying seven eggs per turn, or hunting with three predators, or gathering five pieces of food. The possibilities are endless with 170 unique cards! (Well, not exactly, but we'll get to that later). It is an incredibly streamlined engine builder with a theme that is completely innocuous at first glance, but by the end of the game everybody involved will be looking up local ornithologist clubs. Seriously, almost every review says the same thing: "I couldn't care less about birds, but then I started playing and now I think the theme is genius." It is a really impressive feat the designer Elizabeth Hargrave pulled off, getting people to like birds. The nerve…
Eagle-Eyed Focus
Sorry, I've been rambling, back to the game. It's great. It's great because it streamlines engine building. One of the tricks of the game is that you use cubes to announce what action you will take, and you march your cube from right-to-left down a row when you take one of the three main actions (get food, get eggs, get cards). When I was teaching the game to my wife, she thought that marching the cube down these rows was pretty dumb. By the end of the game she was grateful for such a simple mechanical trick to allow her to easily track what she needed to do on a given turn. Compare this to some other, more unruly, engine builders where you have cards scattered all around your tableau and can easily lose track of things. Streamlining is a powerful tool, and when it is pulled off as well as Wingspan does, it deserves a heap of praise, even if the underlying mechanics of the game aren't breaking any new ground.
Pretty as a Peacock
That's a thing people say, right? The components are top notch and the artwork is great. Oh, the artwork. Each card has a unique, intricate drawing of the bird. It's just so much fun to grab a new card and check out the amazing artwork. The thing I didn't expect was how appealing the game would be to, well, everyone. After posting a picture on social media, I had people who don't play games asking about it. A couple of people followed up with me later asking for the name of the game. People see a beautiful game of birds and they want a piece of that action, apparently. This has no bearing on how good this game is or isn't, but it definitely affects the ability to get the game to the table. Any person who sees this game and doesn't want to let out their inner ornithologist at least once, well that is no friend of mine.
Easy as a Lark
This game teaches quite well. I highly recommend using this video as a guide. It eases players into the game, making it much more approachable than it would be with a big rule dump to begin. It is firmly a medium weight game, so experienced gamers will be fine, but teaching less experienced players can be pulled off rather easily compared to other games of similar weights.
The game also sails by in a very tidy amount of time. As advertised, two player games have consistently been right at, or a few minutes below, 40 minutes. With players who know the game, you can play probably up to four players in an hour or less, which is a great achievement. This is, relatively, a lot of game for that amount of time. My shelf is full of lighter games with longer play times.
I have not tried it, but the game features an extensive solo mode from the fine folks at Automa Factory. The game has you, essentially, playing against a dummy player who doesn't actually build a board, but rather grabs cards for points. You can scale the difficulty as your skill increases. That's an oversimplification, but go watch some video impressions of the solo mode, it appears to be a well thought out and engaging mode.
Clipped Wings
I'm going for bird puns on these headers and it fell apart a long time ago, but here is where I talk about the not-so-great aspects of the game. First, there are 170 unique bird cards which sounds bonkers upon first glance. It is technically true that there are 170 unique birds in this game and each is given beautiful artwork, nice factoids, realistic sizes, and thematically appropriate abilities. The gotcha here is that there are far, far less than 170 unique abilities. One bird will lay an extra egg in the nest type A, another will do so in nest type B, and so on. Some will even do the exact same thing, but have a different habitat, nest, or point value. There is still a lot of variety in the game, but the true variety falls well short of the headline of "170 unique birds!"
Another big issue people seem to have are those eggs. This is a popular "OP strategy" that detractors of the game are quick to bring up. Essentially, if you build an egg-production machine, the entire last round of the game (there are only four rounds) will be best spent simply turning the crank on that egg engine. First, this is a powerful strategy, but it isn't an impossible one to beat. I've beaten it before, and also lost to it. The problem (if there actually is a legitimate problem here, which is certainly debatable) is that if you spend the game building up this egg machine, then producing those eggs in the final round will clearly be the obvious play which can take some fun out of your last handful of turns. It's naturally more fun to get food to recruit a cool new bird which will earn you big points, but it's an engine builder, you have spent the majority of the game building something, now you must turn that crank to reap the rewards. I feel like the egg machine is more like a B+ strategy. If you get the cards to pull it off, it is probably going to be your best bet and you will probably do well and have a good shot at winning. In that way, it feels sort of restrictive. The counterpoint to this is that there are plenty of other viable strategies and if you are hell bent on winning above all else, maybe Wingspan isn't for you?
I also feel like both of these issues are entirely fixable via expansions. A game this popular which is primarily card based is certain to be expanded, so hooray for new abilities and maybe some egg machine balancing.
This One's For the Birds
You, the reader, are a bird in this bad section title scenario. Because this game is for you. Because it's good. Get it? I feel like it is pretty difficult to dislike Wingspan. It's just such an incredibly streamlined, pleasant experience that I have a hard time imagining too many people playing this game and coming away disappointed. Engine builder fans might not be blown away because Wingspan isn't doing anything groundbreaking for the mechanic, but again, it streamlines things in such a way that I suspect many experience engine building players will be able to appreciate it on that level. People who get too wrapped up in hype might come away disappointed that this didn't reinvent board games as we know it. People who enjoy stoking the hype backlash will probably have no problems picking out things to use to put down the game. In actual warning flags, the game is low on player interaction, with almost no negative interaction, so be warned if that is a turn off for you.
For the rest of us, Wingspan offers an incredibly pleasant engine building experience and everything about the game is a joy to look at and touch. If you are looking to break your group into engine building, or introduce some eager new players to an incredibly appealing game, Wingspan will fit the bill.
PARKS Review (Physical Game)
Jan 18, 2020 / By	Chris
Avowel (Wordsy) Review
Yellow and Yangtze Review
Dragon Castle Review
Dec 23, 2019 / By	Chris
King Tactics – Wars of the Roses Review
Terraforming Mars Review
Takenoko Review
Hex Roller Review
Nov 01, 2019 / By	Chris
Copyright 2017-2018 Pixelated Cardboard.


text:
Home/Press Releases/UBISOFT REACHES AGREEMENT WITH VIVENDI FOR ITS FULL EXIT FROM UBISOFT'S SHARE CAPITAL
UBISOFT REACHES AGREEMENT WITH VIVENDI FOR ITS FULL EXIT FROM UBISOFT'S SHARE CAPITAL
boaks March 20, 2018
Paris – March 20, 2018 – Today, Ubisoft announced that it has signed an agreement with Vivendi for its full exit from Ubisoft's share capital, with the sale of all Vivendi's 30,489,300 shares. The transaction includes an investment by two new long-term investors, the Relationship Investing arm of Ontario Teachers' Public Equities division, and Tencent, a share buy-back by Ubisoft, an acquisition of shares by Guillemot Brothers SE and an Accelerated Bookbuilding with institutional investors. Following the implementation of the transaction, Vivendi will no longer hold any shares in Ubisoft, and has committed not to acquire any shares in Ubisoft for 5 years.
As part of the transaction, Ubisoft and Tencent have also announced today a strategic partnership that will significantly accelerate the reach of Ubisoft franchises in China in the coming years.
Yves Guillemot, CEO and Co-Founder, said: "The evolution in our shareholding is great news for Ubisoft. It was made possible thanks to the outstanding execution of our strategy and the decisive support of Ubisoft talents, players and shareholders. I would like to warmly thank them all. The investment from new long-term shareholders in Ubisoft demonstrates their trust in our future value creation potential, and Ubisoft's share buy-back will be accretive to all shareholders. Finally, the new strategic partnership agreement we signed will enable Ubisoft to accelerate its development in China in the coming years and fully leverage a market with great potential."
"Today, Ubisoft is fully reaping the benefits of our long-term strategy and the successful transformation towards a more recurring and profitable business. Ubisoft is perfectly positioned to capture the numerous video game growth drivers in the coming years. We are focused more than ever on delivering on our strategic plan."
Investment from new long-term shareholders in Ubisoft
Ontario Teachers' has committed to acquire 3,787,878 Ubisoft shares (3.4% of capital), equivalent to approximately €250 million and Tencent has committed to acquire 5,591,469 Ubisoft shares (5.0% of capital). These investments are made at a price of €66 per share and do not grant any representation on Ubisoft's board of directors. Tencent has also undertaken not to transfer its shares nor to increase its shareownership and votings rights in Ubisoft.
As part of the transaction, Ubisoft and Tencent have also signed a strategic partnership agreement that will significantly accelerate the reach of Ubisoft franchises in China in the coming years.
The entry of these two high-profile investors in Ubisoft's share capital validates Ubisoft's strategy and confirms the value creation potential for its shareholders in coming years.
Ubisoft share buy-back
Ubisoft agreed to buy back up to 9,090,909 of its own shares (8.1% of capital) from Vivendi through a structured transaction taking the form of a forward sale of Vivendi shares to Crédit Agricole Corporate and Investment Bank (CACIB), and a forward buy-back mechanism of shares from CACIB by Ubisoft, enabling Ubisoft to progressively buy-back shares from 2019 to 2021. This buy-back will be structured through a derivative product whereby Ubisoft will enter into a pre-paid forward agreement on part of the shares, with settlement in shares at maturity in 2021 or by anticipation, and for the remainder of the shares, a total return swap with settlement either at maturity or by anticipation at Ubisoft's discretion, either in cash (Ubisoft either benefiting or supporting the variation in the value of the relevant shares) or with a settlement in shares against the payment of the price for such shares. The share buy-back will be financed mainly through Ubisoft's existing financial resources. In the event of an increase in the size of the accelerated private placement, the number of shares that are bought back by Ubisoft will be reduced accordingly.
These acquisitions will be made at a price of €66 per share.
Shares bought-back are primarily intended to be cancelled with an accretive effect for all Ubisoft shareholders or used as part of share compensation plans or share-indexed compensation plans for employees.
Finexsi, acting as independent financial expert, rendered a fairness opinion on the share buy-back confirming that the financial terms of the transaction were fair for the minority shareholders of Ubisoft and that the transaction was in the corporate interest of Ubisoft.
Guillemot Brothers SE acquisition of shares
As part of the transaction, Guillemot Brothers SE agreed to acquire 3,030,303 shares (2.7% of capital) at a price of €66 per share, bringing Guillemot Brothers SE's ownership to 17,406,414 shares representing 19.4% of voting rights and 15.6% of share capital and the Guillemot concert to 20,636,193 shares, representing 24.6% of voting rights and 18.5% of share capital. The purchase will be implemented through a structured financing in the form of derivative instruments by which Guillemot Brothers SE will enter into a forward contract with CACIB and a collar financing on these Ubisoft shares, maturing in 2021 or by anticipation, and settled in shares or in cash. Shares underlying the collar financing will be pledged to CACIB, who will be authorized to re-use them from Guillemot Brothers SE subject to certain conditions specified in the agreement.
Accelerated Bookbuilding with institutional investors
The remainder of Vivendi's stake, representing 8,988,741 shares (8.0% of capital), will be sold at a price of €66 per share through an Accelerated Bookbuilding with institutional investors. Based on the level of interest in the placement, the size of the Accelerated Bookbuilding could be increased up to 1,500,000 shares, reducing accordingly the number of shares bought back by Ubisoft.
J.P. Morgan Securities Plc is acting as Sole Global Coordinator on the Accelerated Bookbuilding.
As part of this Accelerated Bookbuilding, CACIB, as Guillemot Brothers SE's counterpart in the forward contract and the collar financing will also sell 2,887,879 shares in the hedging of its derivatives operations.
The transaction will be launched today. Final terms as well as the outcome of the placement will be determined at the end of the bookbuilding expected on March 21, 2018. Settlement will take place two trading days after closing of bookbuilding.
Ubisoft financial targets confirmed
Ubisoft confirms its financial targets for 2017-18 and 2018-19, as well as its long-term growth perspectives.
J.P. Morgan Securities Plc and Lazard Frères are acting as financial advisors to Ubisoft while Bredin Prat is acting as legal counsel.
About Ubisoft
Ubisoft is a leading creator, publisher and distributor of interactive entertainment and services, with a rich portfolio of world-renowned brands, including Assassin's Creed, Just Dance, Watch_Dogs, Tom Clancy's video game series, Rayman and Far Cry. The teams throughout Ubisoft's worldwide network of studios and business offices are committed to delivering original and memorable gaming experiences across all popular platforms, including consoles, mobile phones, tablets and PCs. For the 2016-17 fiscal year Ubisoft generated sales of €1,460 million. To learn more, please visit: www.ubisoftgroup.com
Pursuant to the commission implementing regulation (EU) 2016/1055 of 29 June 2016 laying down implementing technical standards with regard to the technical means for appropriate public disclosure of inside information and for delaying the public disclosure of inside information in accordance with Regulation (EU) No 596/2014 of the European Parliament and of the Council, this press release may contain inside information and has been sent to the authorized broadcaster of Ubisoft Entertainment on 20 March 2018 at 17h40 CET
Gaming Ubisoft Vivendi
Boomerang Watches Launch Their Sublime Collection, Blending Vintage Styling with a Modern Twist, and Turn to Popular Kickstarter for Development
Ubisoft and Tencent Team Up to Bring Ubisoft's Top Titles to China
DJI Unveils Technology To Identify And Track Airborne Drones
NC4 to Unveil All New NC4 Street Smart® at IACP 2018
Voyomotive Puts the Power in the Hands of the Consumer
VoIP Innovations Launches Showroom, First CPaaS Marketplace for the Channel


Use an upholstery tool or brush with clean all-white towels.
Never use more than a fine mist of detergent. The fabric should not even get wet.
Only use low pressure when cleaning any kind of fabric.
Use fast, light strokes, and avoid getting the fabric wet.
When cleaning silk, warm up the towel and then turn off the vapor entirely before touching the fabric i.e. if the towel is too hot to touch with your hand, it is too hot for silk.
Be patient with stubborn spots; work on a spot gently for no more than a minute at a time, then wait five minutes for the area to dry and repeat.
Use circular movements or back-and-forth and side-to-side movements to get all sides of surface fibre.
Finish with a brushing in one direction that will give the fabric a uniform appearance.
NOTE: Always determine the colour-fastness of any fabric – especially with reds or blues – by taking a clean, moist, warm towel and gently rubbing a small area as far down on the back or other out of the way place on the furniture as possible. If colour comes off on the towel you may need to have the piece dry-cleaned.


text:
Q: why Sphinxapi not return result? I'm confused about Sphinx. I say about the problem.  My system configuration :

*

*Ubuntu 16.04 LTS

*Apache 2.4.18

*PHP 5.6.21

*MariaDB 10.1.14

*sphinx 2.2.10
My database is test2 and it contains 2 tables (documents and users) and 1 view (search).

*

*documents (table):

*

*id

*name

*users (table):

*

*id

*fname

*lname

*email

*search (view):

*

*sphinxid

*itemid

*data

*datatype
search view query is
CREATE
    ALGORITHM = UNDEFINED
    DEFINER = root@localhost
    SQL SECURITY DEFINER
VIEW search AS
    SELECT
        UUID_SHORT() AS sphinxid,
        users.id AS itemid,
        CONCAT_WS(' ',
                users.fname,
                users.lname,
                users.email) AS data,
        1 AS datatype
    FROM
        users
    UNION SELECT
        UUID_SHORT() AS sphinxid,
        documents.id AS itemid,
        documents.name AS data,
        2 AS datatype
    FROM
        documents
Sphinx configuration file :
source my_search
{
        type                    = mysql

        sql_host                = localhost
        sql_user                = root
        sql_pass                = myPass
        sql_db                  = test2
        sql_port                = 3306  # optional, default is 3306

        sql_query               = \
                SELECT sphinxid,itemid, data, datatype \
                FROM test2.search;

        sql_attr_uint           = itemid
        sql_attr_uint           = data
}

index test1
{
        source                  = my_search
        path                    = /var/lib/sphinxsearch/data/test1
        morphology              = stem_en

        min_word_len            = 3
        # min_prefix_len          = 0
        # enable_star             = 0
}

searchd
{
        listen                  = 9312
        listen                  = 9306:mysql41
        log                     = /var/log/sphinxsearch/searchd.log
        query_log               = /var/log/sphinxsearch/query.log
        read_timeout            = 5
        max_children            = 30
        pid_file                = /var/run/sphinxsearch/searchd.pid
        # max_matches             = 1000
        seamless_rotate         = 1
        preopen_indexes         = 1
        unlink_old              = 1
        workers                 = threads # for RT to work
        binlog_path             = /var/lib/sphinxsearch
}

I used this command to make index indexer --config /etc/sphinxsearch/sphinx.conf --all --rotate . And the result is :
Sphinx 2.2.10-id64-release (2c212e0)
Copyright (c) 2001-2015, Andrew Aksyonoff
Copyright (c) 2008-2015, Sphinx Technologies Inc (http://sphinxsearch.com)

using config file '/etc/sphinxsearch/sphinx.conf'...
indexing index 'test1'...
collected 200 docs, 0.0 MB
total 200 docs, 200 bytes
total 0.007 sec, 28417 bytes/sec, 28417.16 docs/sec
total 2 reads, 0.000 sec, 1.5 kb/call avg, 0.0 msec/call avg
total 10 writes, 0.000 sec, 0.6 kb/call avg, 0.0 msec/call avg
rotating indices: successfully sent SIGHUP to searchd (pid=2287).

I used sphinxapi.php as client api and my php test file is :
<?php

include '../sphinxapi.php';

if(!empty($_GET['q'])){
    var_dump($_GET['q']);
    // Build search query
    $cl = new SphinxClient();
    $cl->SetServer( "localhost", 9312 );
    $cl->SetMatchMode( SPH_MATCH_EXTENDED  );
    $cl->SetRankingMode ( SPH_RANK_SPH04 );
    // Execute the query
    $q = '"' . $cl->EscapeString($_GET['q']) . '"/1';
    $searchresults = $cl->Query($q ,'test1');
    var_dump($cl->GetLastError());
    var_dump($cl->GetLastWarning());
}
?>
 <!DOCTYPE html>

<meta charset="UTF-8">
<title>Sphinx test 1</title>

        <form name="search" method="get" action="">
            <input type="text" name="q" id="q" />
            <input type="submit" value="GO" class="form-submit" />
        </form>

                <?php
                if(!empty($searchresults)){
                    print_r($searchresults);
                }
                ?>

I look at search view and I choose one field ( Scarlett Downsit.fermentum@sapienimperdiet.com) ,but when I search it (something like 'Scarlet') ,I get no result :
Array
(
    [error] =>
    [warning] =>
    [status] => 0
    [fields] => Array
        (
            [0] => datatype
        )

    [attrs] => Array
        (
            [itemid] => 1
            [data] => 1
        )

    [total] => 0
    [total_found] => 0
    [time] => 0.000
    [words] => Array
        (
        [scarlet] => Array
            (
                [docs] => 0
                [hits] => 0
            )

    )
)

Really I do not know the reason why it returns nothing ?

I use this command mysql -h0 -P9306 according to sphinx tutorial.you can see in the picture that I don't have any data (you can see my query in sphinx.conf) and It returns 20 rows!( users table has 100 rows and documents table has 90 rows).

I use this tutorial Integrating Sphinx Search into a PHP Application but I can't get result in my Application! :(

When I use default sphinx.conf and its test database,my application works.I think my sphinx.conf is wrong or maybe it caused by my view (search)!

A: Looking at your query
 SELECT sphinxid,itemid, data, datatype \
            FROM test2.search;

Taking each in turn

*

*sphinxid -> automatically the document_id (first column)

*itemid -> made into a uint attribute (due to sql_attr_uint)

*data -> made into a uint attribute (due to sql_attr_uint)

*datatype - not mentioned, so a text field.

But, your view
... CONCAT_WS(' ', users.fname,  users.lname,  users.email) AS data,
1 AS datatype ...

So looks like your actual text is in 'data', which is then stored in an integer attribute. Not going to work!
Suggests
    sql_attr_uint           = data

is a typo, and SHOULD be
    sql_attr_uint           = datatype

instead? (leaving data to be indexed as a textual field!)

redpajama_set_name: RedPajamaStackExchange


text:
Item #: SCP-551
Special Containment Procedures: SCP-551 is to be contained in a simple cardboard box. It must be of an adequate size to carry all pieces of SCP-551. The box should be stored in a locker unit on Storage Site-23 and at least one (1) Level 1 staff member is to be notified in the event of its removal.
Description: SCP-551 is a standard, five hundred and fifty (550) piece jigsaw puzzle, which should depict, in its finished form, the image of a solitary woman on a small rowboat, surrounded by a stormy sea. However, due to the nature of SCP-551's anomalous qualities, some details of the scene are left incomplete, such as the woman's face and [DATA EXPUNGED].
SCP-551 was found in the apartment of ███ ████ after other residents complained of an odor seeping out from under the door. The severely malnourished body of ███ ████ was discovered beside SCP-551, with several pieces still clutched in her hand. Roughly one third of SCP-551 was pieced together on her floor.
Multiple subjects testing SCP-551 stated that a completion of the puzzle seems inconceivable. The mental reactions of subjects to SCP-551 was diverse, apparently depending less on the puzzle and more on the personality of the subject (see Addenda 551-1/2/3), though the effects of SCP-551 on the psychology of subjects should not be overlooked.
Addendum 551-1
Standard Class-D personnel is tasked with piecing together SCP-551. Subject spent two weeks in a single room, trying to finish the puzzle, and pausing only to sleep. Subject became increasingly frustrated with his progress on SCP-551, which failed to span past forty (40) connected pieces after this time. Subject slept less during his last days working on the puzzle, and was permitted to stop when he [DATA EXPUNGED].
Class-D personnel with a history of addictive behavior is tasked with piecing together SCP-551. Subject acted aloof about the assignment at first, but after connecting two pieces, she seemed to become alarmingly obsessed with SCP-551. Subject stayed beside it for days, sometimes screaming about her lack of progress. After a period of four weeks, subject lost consciousness from lack of sleep, and the test was ended. One hundred and two (102) pieces of SCP-551 had been connected.
Dr. ██████, who scored above average on a standard IQ test, expressed skepticism about SCP-551 and was approved to test it. Dr. ██████ completed all but a couple of sections, specifically the woman's facial features and [DATA EXPUNGED]. Despite this success, Dr. ██████ showed confusion over his remaining pieces and adopted a fatalist attitude toward the puzzle, finally refusing to complete it after four days.
A computer-based approach was taken on the completion of the puzzle. The first tool used was a mechanical arm designed to take a piece and place it in the puzzle, used along with a camera and a desktop computer running an image processing algorithm. The application was tested extensively with normal puzzles; however, when tasked with completion of the puzzle, it would invariably trigger a blue screen or a kernel panic as soon as it finished scanning the piece. An embedded design approach was taken, and the computer was replaced by a microcontroller in charge of moving the piece linked to an image processing DSP; however, the value of the program counter register in all the CPUs would corrupt as soon as the DSP finished scanning the picture of the piece, and in several occasions a sudden, unexpected current peak would result in damage to the CPUs and other components. Automated solutions, therefore, had to be discarded.
« SCP-550 | SCP-551 | SCP-552 »
cognitohazardsafescptoy
page revision: 16, last edited: 01 May 2018 19:32
bpiqo
Balchipedia
The Encyclopedia of Balch History
IB Physics Stuff
- Wikified -
czifz


text:
Volume XX, issue 1, January - April 2014
COMPARATIVE ANALYSIS OF THREE SYNTHETIC UNIT HYDROGRAPHS IN TWO MEDITERRANEAN WATERSHEDS IN THE MAULE REGION OF CHILE
ANÁLISIS COMPARATIVO DE TRES HIDROGRAMAS UNITARIOS SINTÉTICOS EN DOS CUENCAS MEDITERRÁNEAS DE CHILE, REGIÓN DEL MAULE
Roberto Pizarro-Tapia;	Francisco J. Balocchi-Contreras;	Fernando Andrade-Vilaró;	Claudia Sangüesa-Pool;	José Vargas-Baecheler;	Carolina Morales-Calderón;	Mauricio Vera-Camiroaga;	Rodrigo Valdés-Pineda;	Carlos Vallejos-Carrera;	Romina Mendoza-Mendoza;	Claudio Olivares-Santelices;	Alejandro Abarza-Martínez;	Roberto Fuentes-Lagos
Available online: / pages 05-20
This paper compares three methods to obtain synthetic unit hydrographs (SUH).The Snyder (modified for Chile by Astorga and Benítez), the US Bureau of Reclamation, and the Témez methods are analyzed on two watersheds located in Mediterranean areas of Chile. To do so, each watershed was characterized in terms of its morphology and vegetation type. In addition, data from three actual storms, with high, medium, and low rainfall intensities, were used to obtain direct runoff hydrographs (DRH) for both watersheds. The NRCS Curve Number method was used to estimate runoff responses to storm events. Our results suggest that, in general, the SUH used had no significant differences between watersheds. On the other hand, the Snyder SUH method was the only one that found significant differences in the DRHs relative to the other methods and only under a high-intensity storm in the Cunculén watershed.
EFFECT OF THE STAND DENSITY IN THE PROFITABILITY OF Eucalyptus globulus PLANTATIONS
EFECTO DE LA DENSIDAD DE PLANTACIÓN EN LA RENTABILIDAD DE PLANTACIONES DE Eucalyptus globulus
Emilio Guerra-Bugueño;	Fabián Célis-Mosqueira;	Roberto Quiroz;	Norman Moreno-García
This study provides an economic evaluation of the response to planting densities and spacing patterns in Eucalyptus globulus planted for pulping. The Monte Carlo technique was used to examine the effect of price variations and the discount rate on profitability. The trial was carried out in the Central Valley of the IX Region of Chile. The treatments (T) were: 1,000 trees·ha−1 (T1); 1,428 trees· ha−1 (T2); 1,667 trees·ha−1 (T3); and 2,000 trees·ha−1 (T4). The production volume of each treatment was measured at harvest age (10 years), and then a financial analysis was made to obtain the profitability (present net value, PNV; economic land value, ELV; and internal rate of return, IRR). The highest PNV values were obtained with T1 (330 US$·ha−1) and T4 (322 US$·ha−1). The predictions obtained for the PNV of T1 showed a probable occurrence of 73 %, making it the least risky investment option. Higher volumetric yields (T4 and T3) do not lead to higher profitability, since the increase in planting density leads to an increase in the unit cost per plant for land management, weed control and fertilization.
EFFECT OF THE SEVERITY OF FIRE IN THE STRUCTURE CHARACTERISTICS OF CONIFER FOREST STANDS
EFECTO DE LA SEVERIDAD DEL FUEGO EN LAS CARACTERÍSTICAS DE LA ESTRUCTURA FORESTAL EN RODALES DE CONÍFERAS
Diana Yamilet Ávila-Flores;	Marco A. González-Tagle;	Javier Jiménez-Pérez;	Oscar A. Aguirre-Calderón;	Eduardo J. Treviño-Garza;	Benedicto Vargas- Larreta;	Eduardo Alanís-Rodríguez
In order to know to what extent the severity of a fire modifies the structural parameters of a stand, the objective of this research was to conduct an exploratory analysis of the spatial distribution of trees present in mixed conifer stands of the Sierra Madre Oriental, affected by fire during the summer of 1998. The selected area consisted of three mixed conifer stands with three different fire severity levels (low, medium and high). We analyzed the distribution patterns of trees through the Ripley's K function; likewise, we analyzed the spatial interaction of trees in relation to their size and species through a mark correlation function (MCF) kmm(r) . It was observed that according to an increasing fire severity, the spatial distribution of trees tend to aggregate and to maintained the formation of stands dimensionally heterogeneous, however tree species composition was no affected significantly. The influence of fire in these forests was observed as a promoter of dimensional diversity, although spatial mixing of species had a tendency to homogeneity
DISTRIBUTION OF Heliopsis longipes (Heliantheae: Asteraceae), AN ENDEMIC RESOURCE FROM CENTRAL-MEXICO
DISTRIBUCIÓN DE Heliopsis longipes (Heliantheae: Asteraceae), UN RECURSO ENDÉMICO DEL CENTRO DE MÉXICO
V. Gabriela Cilia-López;	J. Rogelio Aguirre-Rivera;	Guillermo Espinosa-Reyes;	Jorge A. Flores-Cano;	J. Antonio Reyes-Agüero;	Bertha I. Juárez-Flores
Heliopsis longipes is a perennial herb endemic to Sierra de Álvarez and Sierra Gorda in central México. It is a species of major economic importance within its genus, due to the traditional uses of its root. Chemical and pharmacological studies have been performed with H. longipes roots, however recent studies regarding its distribution are lacking. The objective of the current study was to establish and document the geographic distribution and existing ecologic conditions of H. longipes. A review of published works regarding this species, as well as an examination of herbarium specimens has been conducted. Explorations in Sierra de Álvarez and Sierra Gorda were also conducted to locate populations of H. longipes. In each site, the physical and biological factors associated with the population were recorded. Heliopsis. longipes is distributed in the states of San Luis Potosí, Guanajuato and Querétaro, in steep canyons with oak and oak-pine forests and substrates of igneous origin, in Sierra de Álvarez and Sierra Gorda.
DEVELOPMENT OF HUIZACHE (Acacia farnesiana) SEEDLINGS IN SUBSTRATES WITH VERMICOMPOST
DESARROLLO DE PLÁNTULAS DE HUIZACHE (Acacia farnesiana) EN SUSTRATOS CON VERMICOMPOST
Alejandro Moreno-Resendez;	Guadalupe Solís-Morales;	Eduardo Blanco-Contreras;	Jesús Vásquez-Arroyo;	Luz M. P. Guzmán-Cedillo;	N. Rodríguez-Dimas;	Uriel Figueroa-Viramontes
The effect of vermicompost, as part of the growth substrate, on the development of huizache (Acacia farnesiana) seedlings placed under a rustic shelter made from reeds was evaluated over a period of 240 days. Five vermicompost-sand mixtures with five ratios, namely 10:90, 20:80, 30:70, 40:60 and 50:50 (% by volume), were assessed, and natural soil from the area where huizaches grow was used as the control. Seeds for producing the seedlings were obtained from the huizaches of the area. The treatments were replicated 30 times, and five seedlings were harvested from each one to determine plant height, main stem diameter, number of branches, and fresh and dry weight. The effect of the treatments was determined using a completely randomized experimental design and the averages were compared by the LSD5 % test. Huitzache growth was not uniform in the different substrates; however, the 10:90 vermicompost-sand mixture had the best variable responses in terms of plant height and fresh and dry weight. Therefore, vermicompost at low concentration promoted the growth of A. farnesiana.
DAMAGE CAUSED BY THE LARGER GRAIN BORER Prostephanus truncatus (Horn) (COLEOPTERA: BOSTRICHIDAE) IN CORN AND BRANCHES OF WILD PLANTS
DAÑOS CAUSADOS POR EL BARRENADOR MAYOR DE LOS GRANOS Prostephanus truncatus (Horn) (COLEOPTERA: BOSTRICHIDAE) EN MAÍZ Y RAMAS DE PLANTAS SILVESTRES
Luz R. Bourne-Murrieta;	Francisco J. Wong-Corral;	Jesús Borboa-Flores;	Francisco J. Cinco-Moroyoqui
Prostephanus truncatus (Horn) is a wood borer insect adapted to stored food products, mainly maize. In this study we quantified losses and damages caused by this insect in 10 varieties of maize and 10 plant species to determine the susceptibility and effects that the insect could provoke if it adapts to the conditions in northwestern Mexico. Maize seeds and pieces of branches of tree species were subjected to artificial infestation by adult P. truncates, and then incubated at 27 ± 1 °C and 70 ± 3 % RH. The preference of insects and damage in each material were determined. Insects preferred and damaged most to "Maizon", a variety of native maize planted by producers of the mountainous region of Sonora. The pieces of branches with higher degree of damage by P. truncatus were Ricinus communis, Jatropha cardiophylla and Parkinsonia aculeata; however, the insect was unable to reproduce in any of the branches. "Maizón" was also the variety that had the most dramatic decline in germination and the highest number of adults of P. truncatus emerged.
MOISTURE AND INORGANIC SUBSTANCE CONTENT IN PINE TIMBER PRODUCTS FOR USE IN PELLETS AND BRIQUETTES
CONTENIDO DE HUMEDAD Y SUSTANCIAS INORGÁNICAS EN SUBPRODUCTOS MADERABLES DE PINO PARA SU USO EN PÉLETS Y BRIQUETAS
Fermín Correa-Méndez;	Artemio Carrillo-Parra;	José G. Rutiaga-Quiñones;	Francisco Márquez-Montesino;	Humberto González-Rodríguez;	Enrique Jurado-Ybarra;	Fortunato Garza-Ocañas
The forest industry in the municipal seat of Nuevo San Juan Parangaricutiro and the Indigenous Community of Nuevo San Juan Parangaricutiro, located in Michoacán state, Mexico, generates 1,232 m3·year-1 of underutilized pine sawdust and shavings. The sawdust and shavings of Pinus leiophylla Sch. Et Cham., P. montezumae Lamb. and P. pseudostrobus Lindl were subjected to physicochemical analyzes to determine if they meet the requirements for pellet and briquette production. The moisture, ash, and inorganic element contents in the byproducts were determined using international standards. Moisture content in ash was 51.5 ± 1.9 %, and 53.7 ± 0.1 % in shavings; these values exceeded the maximum allowable. Ash content in sawdust and shavings was 0.26 ± 0.03 % and 0.34 ± 0.03 %, respectively. For the three species evaluated, the average percentage of calcium, potassium, magnesium, phosphorus, sulfur, silicon, iron, aluminum and sodium in sawdust was 47.1 ± 2.8, 26.0 ± 2.5, 13.5 ± 0.4, 5.0 ± 0.4, 3.2 ± 0.4, 2.3 ± 0.8, 1.0 ± 0.1, 1.3 ± 0.4 and 1.4 ± 0.3, respectively, while the average percentage was 43.2 ± 7.0, 16.5 ± 3.0, 10.1 ± 4.8, 4.0 ± 0.6, 1.8 ± 0.2, 3.6 ± 0.3, 1.0 ± 0.6, 1.1 ± 0.1 and 1.0 ± 0.6 in shavings, respectively. Arsenic was only found in the shavings (17.1 ± 17.1). Based on the results, sawdust is the most suitable byproduct for pellet and briquette production.
BIOLOGICAL QUIALITY OF WASTEWATER USED IN IRRIGATION OF FORAGE CROPS IN TULANCINGO, HIDALGO, MEXICO
CALIDAD BIOLÓGICA DE AGUAS RESIDUALES UTILIZADAS PARA RIEGO DE CULTIVOS FORRAJEROS EN TULANCINGO,HIDALGO, MÉXICO
Elizabeth Hernández-Acosta;	Evangelina E. Quiñones-Aguilar;	David Cristobal-Acevedo;	J. Enrique Rubiños-Panta
Available online: / pages 89-100
The use of wastewater in irrigation of forage crops is a practice that increases daily in areas where water, for this purpose, is scarce. However, growers, when being in direct contact with wastewater, suffer from gastrointestinal diseases caused by coliforms and parasites (helminths). In the present study, we evaluated fecal coliform (in wastewater, soil and plants) and helminths (in wastewater) in module II, Irrigation District 028, Tulancingo, Hidalgo. Bacteriological and helminth analyzes were consistent with the methodologies reported in the NMX-AA-003-1980, NOM-001-SEMARNAT-1996, PROY NMX-AA-042-SCFI-2008 and section 9810 APHA. A total 16 water sampling sites were determined in irrigation channels and 54 samples of both soil and plants were taken. The highest fecal coliform concentrations were 2 x 1010 MPN·100 mL-1 of water, 109 MPN·100 g-1 of soil, 109 MPN·100 g-1 of root and 3 x 109 MPN·100 g-1 of stem. Eleven of the 16 sampling sites were helminths. We suggest treating wastewater before use, to prevent health problems among growers.
EFFECT OF CULTURE MEDIUM ON DEVELOPMENT OF Suillus granulatus (L.) Roussel AND S. brevipes (Pk.) Kuntze
EFECTO DEL MEDIO DE CULTIVO EN EL DESARROLLO DE Suillus granulatus (L.) Roussel y S. brevipes (Pk.) Kuntze
Dulce Ma. Murrieta-Hernández;	Juan Carlos Noa-Carrazana;	Martín Mata-Rosas;	María del Rosario Pineda-López;	Ramón Zulueta-Rodríguez;	Norma Flores-Estévez
The mycelial growth rates of ectomycorrhizal fungi Suillus granulatus and S. brevipes were assessed in three culture media (PDA, BAF and MMN) at two pH values (4.8 and 5.8) in order to select the best culture medium. The strains were isolated from sporocarps collected in a Pinus hartwegii forest in Cofre de Perote National Park, Veracruz, Mexico. Significant differences (Tukey, P ≤ 0.05) in the growth area of both species were found. The highest values were recorded in the PDA medium. Concerning the pH values tested, there were no significant differences. Each of the tested media can be used for culturing the S. granulatus and S. brevipes strains, depending on the objectives. The PDA medium was the best substrate for the growth of the strains. We suggest using the BAF medium for mass production of mycelium for inoculum, and the MMN medium for either strain maintenance or mycorrhization testing.
MINERAL AND CHLOROPHYLL CONTENT OF THE Psittacanthus calyculatus (DC) G. Don HEMIPARASITIC PLANT AND FOUR HOST TREES
CONTENIDO MINERAL Y DE CLOROFILA DE LA HEMIPARÁSITA Psittacanthus calyculatus (DC) G. Don Y DE CUATRO DE SUS ÁRBOLES HOSPEDEROS
J. Carlos Raya-Pérez;	J. Gabriel Ramírez-Pimentel;	Jorge Covarrubias-Prieto;	Bryan Acevedo-Lara;	César Aguirre-Mancilla
We collected leaves from the Psittacanthus calyculatus hemiparasitic plant and Salix taxifolia, Ulmus divaricate, Fraxinus uhdei y Prosopis laevigata host trees, to understand and compare the contents of Mg, Al, Si, P, S, K, Ca, chlorophyll and protein. Analyses were performed with a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). The results showed that the hemiparasitic plant accumulated (at least twice) more K compared to its host trees, indicating that the hemiparasitic plant use an active mechanism to achieve this accumulation. According to the statistical analysis (P = 0.05), U. divaricate is the species that accumulates more S, Si and Ca. Mg content was also higher in U. divaricate, but was statistically similar (P = 0.05) than in the hemiparasitic plant. P content was similar (P = 0.05) in both P. calyculatus and their host trees. Fraxinus uhdei accumulated more C than the rest of the species. Chlorophyll content was higher in F. uhdei and S. taxifolia, while P. laevigata had the lowest content. P. calyculatus leaves had high protein content (21 %).
TREE STRUCTURE AND DIVERSITY OF SECONDARY VEGETATION DERIVED FROM A SEMI-EVERGREEN TROPICAL FOREST IN QUINTANA ROO
ESTRUCTURA Y DIVERSIDAD ARBÓREA DE VEGETACIÓN SECUNDARIA DERIVADA DE UNA SELVA MEDIANA SUBPERENNIFOLIA EN QUINTANA ROO
Roy J. Carreón-Santos;	Juan I. Valdez-Hernández
The structure and diversity of a semi-evergreen tropical forest in the Andrés Quintana Roo ejido, located in the municipality of Felipe Carrillo Puerto, Quintana Roo, Mexico, was analyzed. To this end, six sampling units of 20 x 50 m (1,000 m2), two units per tropical forest development condition (age of disturbance), were established: a) forest fire 10 years ago (C10), b) agricultural use 24 years ago (C20) and c) pastoral use 33 years ago (C30). Forest structure was characterized by the diameter and height distribution of individuals in each condition, as well as using the importance value (IVI) and forest value (FVI) indices. Pouteria reticulata was the species with the highest IVI and Ficus sp. had the highest FVI, both in C10 and C20, while Bursera simaruba and Lysiloma latisiliquum obtained the highest IVI and FVI, respectively, in C30. Species diversity was evaluated using proportional abundance (Shannon: H') and floristic similarity (Sorensen: IS) indices. Species diversity of seedlings, poles and saplings was higher in C10, C30 and C20, respectively. Poles had on average floristic similarities of 60 % between forest development conditions, while seedlings and saplings had less than 50 %.
GROWTH AND PRODUCTION OF Trema micrantha (L.) Blume , TREE USED FOR AMATE PAPER
CRECIMIENTO Y PRODUCCIÓN DE Trema micrantha (L.) Blume, ÁRBOL PARA PAPEL AMATE
Udavi Cruz-Márquez;	Patricia Negreros-Castillo;	Citlalli López-Binnqüist;	Carl W. Mize
Received: 2013-07-13
Accepted: 2014-03-04
In the community of San Pablito in the Sierra Norte de Puebla, Trema micrantha (known in Mexico as jonote) generates 80 % of the bark used to produce one of the most important and well known Mexican handicrafts: amate paper. Most community members are involved in this economic activity; however, bark supply is irregular and inadequate and comes from far away. This study has three objectives: evaluate the interest of people from neighboring communities to increase the production of jonote, document the silvicultural practices and evaluate the growth rate (tree height and diameter). Out of 28 farmers interviewed 40 % were interested in increasing jonote production and 20 % use silvicultural practices such as pruning, elimination of shade, transplanting and adding organic matter. Based on the measurements of 396 trees of estimated age, this species can obtain an average diameter of 7 cm after one year and 16 cm after 5 years. The best growth was observed on sites with slopes less than 70 %, altitudes between 1,200-1,600 m, fertile soils and direct light. Recibido
THE STAND STRUCTURE AND ECOLOGICAL FUNCTION OF WOODS IN HEFEI ROUND-THE-CITY PARK, ANHUI PROVINCE, CHINA
LA ESTRUCTURA DEL RODAL Y LA FUNCIÓN ECOLÓGICA DEL ARBOLADO EN EL PARQUE CIRCUNDANTE DE HEFEI, PROVINCIA DE ANHUI, CHINA
Wang Jianan;	Wu Zemin;	Wang Yuan;	Hui Liu
Hefei Round-the-City Park has typical urban forest characteristics. This paper uses vegetation ecology methods to analyze the community structure of the park, and species composition, tree-height distribution and DBH (diameter at breast height) were described. There are 27,662 trees in the study area, which has an urban forest area of 42.5 hm2. The average DBH was 19.2 cm, stand density was 651 trees·hm2 and average basal area was 20.8 m2·hm-2. Based on a health assessment, the trees in the park are in generally good health, as the healthy trees in the urban forest in the park accounted for 53.4 % of the total number. Through calculation of tree growth index and association correlation of component species in the park, the community structures were analyzed. The results show that community structures in the park are complex; there are 22 pairs of species with positive association and individuals in the following communities grow well and are more stable, including mainly Platycladus orientalis-Prunus cerasifera f., atropurpurea-Osmanthus fragrans, Robinia pseudoacacia-Ligustrum lucidum, R. pseudoacacia-Ginkgo biloba-Photinia serrulata, Populus canadensis-L. lucidum-O. fragrans, Sophora japonica-L. lucidum-Buxus sinica, Cyclobalanopsis glauca-Distylium racemosum.


Generation Citizen Wants to Visit You!
Today's young people are passionate about changing the world – they want to make things better in their neighborhoods and cities. But they are inundated with negative media about the political process. And yet, it's still the way that real change happens in our country. Politics is the most effective way to drive lasting change. Generation Citizen is out to prove that politics can be positive – and that it starts with young people. To do this, we need to give them the necessary tools and knowledge to engage with the system, to make it work for them. Our Democracy Fellows are here to help.
Through Generation Citizen's Democracy Fellows Program, learn from young people who are building a positive voice for politics, and have made the process work for them. Engage with CoFounder Scott Warren (Brown University '09) on how to take action on the issues that matter most to you, like teen jobs, public transit, community policing, or education reform. Connect with middle, high school, and college students who are working to drive real change across the country. Get ready to use politics to make a difference in your community.
We want to visit your organization! We will work to coordinate a program that works for your timeframe and audience.


yeh, just looked at mine, it says that its loaded... but when i take it off and put it back on, it says the upload has failed.
Is it just me or is the calendar not working for 2007. When I click on Jan, it just displays december.


Something odd occurred this week: Fox News -- spewing filth churned out by the lowest depths of right-wing innuendo swamps -- was "reporting" the two-pronged falsehood that Barak Obama attended a "madrassa" as a child and that it was Hillary Clinton's campaign which maliciously disclosed that story. There is, of course, nothing at all odd about any of that.
But in response, the national media -- rather than merely passing those accusations along -- decided instead to subject them to critical scrutiny, investigate the claimed basis for the accusations, found that there was no basis, and then reported that the story was completely unfounded. Or, to put it another way, they fulfilled their most basic and defining function as "journalists" by investigating, rather than reciting, other people's claims.
Encouragingly, the media is beginning to engage in a similar exercise concerning the President's war-pushing accusations towards Iran. And they are finding that those accusations have about as much basis as Fox's Obama/Hillary story did.
In his "surge" speech two weeks ago, the President claimed that "Iran is providing material support for attacks on American troops." As a result, he vowed: "We will disrupt the attacks on our forces. We'll interrupt the flow of support from Iran and Syria. And we will seek out and destroy the networks providing advanced weaponry and training to our enemies in Iraq." By all accounts, he intends to repeat that accusation and those threats against Iran in his State of the Union speech.
If this were 2003, every front page headline and lead-in to every television news programs would declare: "Iran responsible for attacks on U.S. troops." The more conscientious ones might add the phrase ", the President reveals." But all of the stories would contain one paragraph after the next asserting the administration's claims about Iran as fact, and would include no investigation of those claims or any real contrary assertions. That was government propaganda masquerading as "independent reporting" -- entire stories, day after day, published as fact based on nothing other than the claims of the government ("Bush officials said"; "senior administration officials today disclosed", etc. etc.).
Since late August, British commandos in the deserts of far southeastern Iraq have been testing one of the most serious charges leveled by the United States against Iran: that Iran is secretly supplying weapons, parts, funding and training for attacks on U.S.-led forces in Iraq. . . . . There's just one thing.
The lack of publicly disclosed evidence has led to questions about whether the administration is overstating its case.
And, to the extent there is any evidence of Iranian involvement in Iraq, it is to aid Shiite factions (such as The Supreme Council for Islamic Revolution) which "are not those that have led attacks against U.S. forces. Instead, they are nominal U.S. allies."
I've come to a much darker interpretation of Iranian actions in the past 12 to 18 months . . . There is a clear line of evidence that points out the Iranians want to punish the United States, hurt the United States in Iraq, tie down the United States in Iraq.
But when Bush officials claim they have "evidence" of Iran's violent behavior towards the U.S. in Iraq, what they mean by "evidence" is the same kind of "evidence" on which the pre-war Iraq claims of WMDs and Iraq-Al Qaeda alliances were based: namely, wild, unverified claims from Chalabi-like, AEI-touted, pro-Iran-war "sources" -- the kind who rant recklessly to Michael Ledeen and other warmonger pundits.
As Justin Raimondo pointed out, there is a critical difference between "intelligence" and "evidence." In the Bush world, "intelligence" includes "anything said by 'sources' no matter their credibility or agenda," and they then characterize those unverified claims as "evidence" (as in: "There is a clear line of evidence that points out the Iranians want to punish the United States, hurt the United States in Iraq").
But as was true for the administration's pre-war Iraq claims, they have "intelligence" but no "evidence" (despite extensive searching) to support what they hope are their pre-war accusations against Iran. And no rational person -- and, apparently, even fewer journalists this time around -- are going to accept Bush accusations towards Iran without "evidence."
While it is certainly encouraging to see national media outlets subjecting Bush claims to genuine scrutiny, that alone is not going to defuse the grave threat posed by the President's clear intent to confront Iran one way or the other. It is highly doubtful that the administration believes it can roll out some grand marketing campaign for a new war against Iran similar to the one it unleashed for Iraq. That is not what it is attempting here.
Instead, the administration wants to take a more circuitous route to creating a conflict with Iran -- by provoking the Iranians, contriving a pretext for an attack, fostering war-generating miscalculation, etc. These increasingly bellicose accusations against Iran are designed to create and fuel that climate. Exposing the utter falsity of the President's statements regarding Iran is an important and valuable exercise, but it is not sufficient to impede an American attack of some sort on Iran.
The President's desire for war with Iran doesn't depend upon convincing Americans and the Congress as part of some grand debate of the need for a new war. They know they can't achieve that. The plan depends upon the hope (and belief) that nobody and nothing can stop the administration as it finds a way to escalate what we are doing in Iraq until it gradually includes Iran.
The administration and its allies have already begun aggressively asserting that the President does not need Congressional authorization or anything else in order an outright attack on Iran. When it comes to their war plans, they don't care about public opinion anymore. For that reason -- as was amply demonstrated by the President's now already underway "surge" plan -- merely winning the public debate over Iran will not be anywhere near sufficient to impede the President's plans regarding Iran.
I will be on Air America with Sam Seder this morning at 9:20 a.m. EST to discuss the testimony of Alberto Gonzales last week before the Senate Judiciary Committee. Local listings are here and you can listen by audio feed here.
UPDATE: Via Steve Clemons, this is a somewhat disturbing (though not at all surprising) account from The Financial Times' Gideon Rachman of an event (attended by Rachman) held in Herzliyah, Israel in which Iran War fervor was everywhere (h/t Freedom). The participants included John McCain and Rudy Guiliani (by satellite) and, in person: Newt Gingrich, Ehud Olmert, Benjamin Netanyahu, Richard Perle, James Woosley, the State Department's Nicholas Burns, and the Defense Department's Gordon England. John Edwards will appear by satellite, too. Anyone who doubts that an Iran-U.S. military confrontation is possible should read Rachman's account.


We opted to go to the Roseland Peninsula, as my wife had holidayed there as a child. On the whole the area was quiet (3 weeks before Easter), so not all attractions/coffee shops, etc, were open yet. Though the well stocked shop in Porthscatho was open, as well as the pub – The Plume of Feathers (it does a great Sticky Toffee pudding, with enough clotted cream that your arteries will harden on sight) and a little coffee truck at the National Trust car park at Porth (handy for Towan Beach).
Get the camera out of the bag!
As ever, on a family holiday, its not about the photography. However…I was not going to let the opportunity pass to photograph a new location. I'll be honest and say that the camera stayed firmly in the bag, only coming out for a couple of "classic" seascapes, that I will post about another time. It wasn't until I went on a walk, and actively chose to carry the camera, and shoot handheld, that I got my photographic mojo and started seeing things that I wasn't seeing before (as the camera was in the bag).
There is probably a good argument to be had for always carrying your camera, I feel it makes me think more creatively and there is less of an excuse not to bother with a shot (as you have to set up for it) as the camera is already out. So in my opinion it encourages play and experimentation, that if you had the camera in the bag, and shot with the tripod, the shots would never happen – or at least they won't happen with me as I am prone to a certain degree of laziness.
It did get me in to a wee bit of trouble when trying to get some shots, that either required me bumsliding down a smooth 45 degree rockface (and then getting back up it), or trying to find a stable footing on said rock face to take some more abstracts. I also found a lovely abandoned boat that was full of interesting detail on the same walk – more of that another time.