The teachers and parents of Montessori students see many benefits from the practices of authentic Montessori teaching. This philosophy of education for the primary, middle, and upper Montessori programs offers a different kind of classroom and a different way of guiding social, emotional, and academic development. From a love of learning, to practical life skill mastery, to the growing independence and confidence in multiple contexts, students demonstrate the positive outcomes of one of Montessori's key practices: freedom of choice. These desirable characteristics and skills that Montessori Pre-school education fosters can be seen in the role of the teacher in the classroom, the classroom environment itself, and the ways parents bring the practice of freedom of choice into their homes.
In the Montessori classroom, teachers are observers, guides, and facilitators. In all these roles, the teacher creates space for freedom of choice. It is up to the student to determine what piques their curiosity, the best method to satisfy it, and the way they want to share or demonstrate mastery of the subject. Teachers utilize broad, relevant, and interconnected curriculum topics and substantial blocks of time during the classroom day to allow students to independently choose and pursue their learning goals.
In order to foster freedom of choice, while not overwhelming a student with a disorganized space or hobbling their curiosity with a chaotic classroom, Montessori teachers take great care to create an environment prepared for learning. The Montessori classroom is designed with all classroom amenities within reach and the learning tools and activities they need on accessible shelves. There are ample surfaces and space for students to do their independent work, to form small groups, or to access the teachers who are, themselves, ready classroom resources. The prepared environment evolves as students learn and acquire skills, and creates the dynamism necessary to truly host a student's freedom of choice in their learning process.
Some Montessori parents will extend these practices to their home and the way their family functions as a whole. While many families may not be able to achieve a prepared environment in the same way a Montessori elementary school classroom can, some will encourage the practice of practical life skills with child-sized household tools, like brooms or food preparation utensils, or provide access aids like stools and low-level storage. Families may also incorporate more choice into family time, authentically asking what activity their child wants to engage and how they want to help in the execution of it. There are many ways to bring Montessori practices home, and in this regard, Montessori teachers can be an excellent resource for parents too.
Day Star Montessori recommends introducing your Montessori preschool children to simple tasks and building to more advanced responsibilities as they get older. To give you an idea of what works best for preschool children, we've put together some simple ideas to get you started– and your children motivated.
Some of the activities that are common in Montessori preschool include picking up toys, sorting trash and recyclables, and placing books on a bookshelf. These are all great tasks for small children from daycare through kindergarten. In addition to gaining a sense of responsibility, these tasks also help with sorting sets of objects and other higher logic functions.
Preschoolers are ready to start putting dirty clothes in the hamper or even putting away their own clean clothes. They can also help with parts of the daily routine such as helping set or clear the dinner table, giving food or water to pets, and setting out their clothes or packing their book bag to prepare for school the next day.
By the time your child is ready for preschool, they are also ready to take a personal interest in hygiene. Brushing their teeth, washing up for dinner, and taking nightly baths are all appropriate for preschool children– although they may need a little help with bathing properly at first. You may even want to keep a whiteboard with a daily checklist which will help them learn to read in the process of doing regular chores.
Keep a partial jar of peanut butter and a small squeeze bottle of jelly available for your children to make their own simple snacks. You may want to use a clothespin to seal the bread bag, and pre-package chips or other finger food to reduce the potential for spills. Allowing your preschooler to be more independent is a big step in helping her prepare for the added responsibility which comes with going to 1st grade and beyond.
Becoming more responsible is a big part of Montessori preschool, and providing age-appropriate chores at home is beneficial in showing children that they can play an important role in home life, which in turn leads to taking on a more responsible role in their larger community.
Eating healthy is a subject which comes up early in Montessori preschool classrooms because it is such an important part of childhood development. The stereotype of children who refuse to eat fruits or vegetables is not as common as you may think, and there are some enjoyable ways to help build an interest in not only fruits and vegetables, but locally grown produce from your own community.
Because of their hands-on approach to learning, trying new foods can be easily adopted into the Montessori preschool. For example, preparing a tossed salad gives children an immersive way to become interested in fruits and vegetables. Allow your children to choose some of the ingredients themselves, and be sure to add healthy options like romaine lettuce, baby carrots, and bean sprouts. Sweet fruits like pineapple, fresh cherries, and watermelon chunks add a delightful flavor.
Make it a habit to visit the local farmer's market once or twice a month. Many communities have weekly markets which allow local farmers to offer their fruits and vegetables direct to the public. Seeing the kinds of organic foods are being produced locally helps children feel closer to the foods they eat and gives them a glimpse of who is providing them.
Instead of cookies and candy, keep a selection of fresh-cut fruits and vegetables on hand for anytime snacking. To satisfy their sweet tooth, provide sweet dips, fresh honey, or a fruit puree so your kids will still be getting a sugary flavor while they consume healthier foods.
All over the country, local communities hold festivals celebrating the harvest of their local fruits and vegetables. Strawberries, pumpkins, apples and even things like corn and avocados are celebrated within driving distance of the Bay Area. These cultural events include music, games and a taste of the local produce. Unlike the farmer's markets, produce festivals tend to be more entertaining for young children who are engaged in discovering the world they live in.
There are a lot of ways you can get your children to eat more fruits and vegetables without resorting to tricks or forcing them into unwanted behavior. When you make eating healthy foods exciting and fun, your children will begin to enjoy trying new taste sensations.
A portion of the daily curriculum at your local private elementary school is intended to help children become viable, responsible members of their community. Through projects and activities, children learn about many different subjects, with the underlying goal of building self-esteem and becoming personally responsible for their own actions.
Acting out scenarios in their private elementary school helps children learn to be more responsible. This also helps kids learn to see both sides of a disagreement or confrontation and learn alternative ways to deal with such problems.
The Montessori Method itself is intended to teach responsibility, although the concept can readily be applied to other educational systems. Children choose their own activities, but conform to an underlying structure and agree to abide by their decisions. In this way, they learn that their choices have meaning and the importance of following through on them. Even the mixed ages of Montessori classrooms are intended to help children be more responsible, not only for themselves but for the community that is their classroom.
Any classroom activity which requires the participation of multiple students is a type of cooperative project. When all of the children in the group work together and perform their individual tasks, the project can be successfully completed. This teaches personal responsibility and relies on students encouraging one another to complete their specific tasks.
Art, writing, and group discussion are all activities which can be geared toward lessons of responsibility. Students can work independently or in groups to develop examples of responsible behavior, while the teacher acts as a guide and advisor to help children reach responsible conclusions.
Performing responsibly is a critical component of learning. It gives children a sense of awareness concerning their role in group activities and ongoing projects. Without the self-control which comes from being responsible, children can develop unruly behavior patterns which are more difficult to overcome later in life.
Montessori classrooms differ from traditional classrooms in several ways, and one significant difference is the way the physical space is arranged. Vital to the Montessori Method is the "prepared environment," a term for the specific dynamic, layout, and learning materials that comprise the classroom. The prepared environment is a powerful tool for the Montessori teacher and is cultivated with care. Likewise, students from primary to upper elementary Montessori programs engage with the prepared environment with curiosity and help to guide its evolution throughout the school day and year.
In her experience teaching and as she cultivated the Montessori philosophy of education, Maria Montessori observed the powerful influence the physical properties of the classroom had on her students' capacity to learn. In her first position as a teacher, it did not take her long to see the need to alter the classroom layout she inherited: the familiar rows of desks and chairs that monopolize the space and face the front of the room where the teacher is positioned as the sole arbiter of learning. Instead, Montessori moved the desks into clusters around the room, introduced open spaces and unobstructed walkways for students to move through as they chose, and stationed learning tools and activities on easy-to-reach shelves on the periphery the room. She emphasized natural light, uncluttered surfaces, access to the outdoors, and physical movement. Montessori believed that students learn best by doing and by letting their innate interest and curiosity guide their acquisition of knowledge. In today's Montessori classrooms, the prepared environment is constructed to facilitate this learning process and offer opportunities for students to observe the teacher in hands-on demonstrations, collaborate with their peers in small groups, or have space to work independently.
When students are encouraged to guide their own learning, the classroom becomes a dynamic space. In the prepared environment of Montessori classrooms, teachers are not tasked with lecturing, corralling, or generally battling with energetic bodies to keep still. Instead, Montessori teachers are asked to observe students as they engage the learning tools and activities and offer support and new challenges. As students progress in a lesson and want to further explore the topic, or are in need of further practice with the concept, Montessori teachers can introduce new or different learning tools to the shelves, or encourage small groups to form where students can teach and learn from each other. Montessori teachers receive constant feedback in the form of the students' engagement with the prepared environment and can adapt the classroom to meet their curiosity.
As our nation's first President, George Washington is a very important person. Teaching preschoolers about him can be a little tricky, but there are quite a few activities available to make the task easier. We encourage you to incorporate a few educational activities at home as well.
Coloring in images related to George Washington will introduce children to the Father of our country in a fun way. You can use the images found here, or choose a few of your own. Better yet – tell your kids about some of Washington's greatest feats and ask them to draw their own interpretations. Keep in mind that the outcome does not have to be accurate so long as the children convey what George Washington means to them – and to all of us.
Creating a tri-cornered hat or wearing replica clothing of the era is another way to introduce kids to George Washington. The activity will do more than teach preschoolers about our first President – it will also help them develop fine motor skills and give them hours of fun things to do and talk about. The girls shouldn't be left out, and can dress up like George Washington's wife Martha or even Betsy Ross who designed the nation's first flag.
George Washington's life is well documented, and sharing some of the more notable achievements will help children understand why the man is so important. He was more than the first president – he also played a key role in the War of Independence and worked hard to shape the way our government worked after the war was won. You can even take your kids on a virtual tour of the White House, or Washington's home of Mount Vernon.
Unlike traditional education, Day Star Montessori uses play-based learning to teach kids about subjects of historical interest. This method is more effective than rote memorization from a textbook and can be a lot of fun for the kids. If you would like to know more about the Montessori Method or the curriculum we teach at Day Star, contact us today.
Preschool children need more sleep than older kids or adults. Experts agree that preschoolers need between 11 to 13 hours of sleep a day, including one daytime nap. This helps children develop properly and contributes to better health and fewer behavioral problems. To help you establish a sleep routine that works for your child, we have compiled some helpful information from specialists, parents, and educators.
Preschoolers need a schedule that they can adjust to. This includes routines and schedules that can be followed day after day. It is okay for your little ones to stay up later now and then, but they need a regular pattern that works for you and them most of the time. This includes bathing, dressing for bed, and even a bedtime reading session that you are able to stick to. If you are not able to adjust your schedule to the desired routines, you may have to modify the routines so that your schedule is not a problem.
Your child's sleep routine should be something simple. You want them to prepare for bed and follow a normal routine, but overloading the evening schedule can make doing so more difficult for everyone and may even have undesired consequences for small children. Try to keep the nightly routine down to a handful of specific tasks and perform those tasks in the same order every night.
Devise a chart or checklist to help your child with the nightly routine. This helps your child feel like they have more power over their lives and gives them a sense of accomplishment. In a busy household, it will also help you keep track of where your children are in the sleep routine process. The checklist should be a list of things which need to be done daily, including the parts you participate in as well, such as reading a bedtime story or assisting with choosing an outfit for the following day.
Your child's sleep routine will be different than other children. It may take a week or two to establish the best schedule, but once you have it worked out, it is important to stick to the routine. At Montessori Children's Center, we encourage our preschoolers to play and explore on their own, while still maintaining a set educational routine. To learn more about the Montessori Method, contact us today.


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Matt serves as an estimator in the commercial roofing department at Bone Dry Roofing Company. Matt brought his experience in both field management and site planning to create a perfect background and fit for our commercial estimating needs. Matt is a 2008 graduate of the University of Georgia. He enjoys spending time with his wife, family, and friends, as well as playing guitar with his church band, woodworking, and being outdoors. He lives with his wife Jacki and daughter Tensley in Watkinsville and are active members of Watkinsville First Baptist.


text:
\section{Introduction}

Speculations that instantons could induce  diquark condensation
in low temperature but high density quark matter \cite{RAPP,ALFORD}
have revived the interest in the diquark clustering in the nucleon.
It is  sometimes also argued that diquark condensation may occur even
at  moderate densities, for example in heavy nuclei. This problem is
strongly related to the question  of instanton induced  diquark clustering
in the nucleon. Indeed, the instanton-induced 't Hooft interaction
is strongly attractive for a quark-quark pair with quantum numbers
$T,J^P=0,0^+$ (scalar diquark). This raises expectations that
it binds a scalar diquark and
is responsible for the scalar diquark-quark structure of the nucleon
\cite{RAPP,SHURYAK}. This assumption is based on the iteration of
the 't Hooft interaction in the $qq$  s-channel. However, this
picture of the quark-quark interaction in baryons is only a small
part of a more general one, based on the effective meson-exchange
interaction \cite{GR,GLOZ}. When the 't Hooft interaction is first
iterated in the $qq$ t-channel it inevitably leads to  Goldstone
boson exchange between constituent quarks, which is drastically
different  from the initial (not iterated) 't Hooft interaction
due to  the (anti)screening effects.

The latter effective meson-exchange interaction does not induce
a bound scalar diquark, nor an appreciable diquark-quark
clustering in nucleon.
This effective meson exchange interaction
is also the most attractive  in $0,0^+$ $qq$ pairs, but the nature of this attraction
is very different  from that of the 't Hooft interaction.
This interaction, however, is not strong enough to bind the scalar
diquark. When it is combined with a confining interaction it binds
the diquark in the sense that there is no asymptotic state with
two free constituent quarks, though the mass of the scalar diquark
is a few tens of MeV above the two-constituent-quark threshold.
There is no significant diquark clustering in the nucleon either,
because the nucleon is intrinsically a three-quark system and the
fermionic-nature of the constituent quarks plays  an important  role.
If the subsystem of quarks 1 and 2 is in the $0,0^+$ state then
due to the antisymmetrization the quark pairs in the subsystems
1-3 and 2-3 are also partly in the $0,0^+$ state.
This implies that a strong attraction in $0,0^+$
quark pair contributes  in all quark subsystems simultaneously
and makes the nucleon compact, but without appreciable
quark-diquark clustering.

This paper consists of two independent, but
interrelated parts. In the first one we discuss
how the instanton-induced interaction
(or some general nonperturbative gluonic interaction)
leads to the poles when it is iterated in the
$qq$ t-channel. These pole contributions have an evident
meson-exchange interpretation. The latter meson-exchange
interaction is drastically different from the initial (bare)
't Hooft interaction which becomes strongly enhanced in the
channel of Goldstone boson exchange quantum numbers.

We also discuss the role of instantons in ${\bar q}q$
systems.
There is no new wisdom in that the nonperturbative
gluonic configurations, e.g. instantons, induce the dynamical
breaking of chiral symmetry  and explain the low-lying mesons.
We include the latter discussion only with the purpose of showing
how the nonperturbative gluonic interaction  both explains mesons
and  at the
same time  leads to the effective meson exchange
picture in the $qq$ systems. Through the latter it also explains
the baryon spectra and the nuclear force. Our discussion is rather
general, and does not necessarily rely on the instanton-induced
interaction picture. Any nonperturbative gluonic interaction,
which respects chiral symmetry and induces  the rearrangement
of the vacuum (i.e. dynamical breaking of chiral symmetry), will
automatically explain the $\pi - \rho$ mass splitting and will
imply a meson-exchange picture in baryons.

The second part of this paper is devoted to a detailed study
of diquark clustering in the nucleon, based on the effective
meson-exchange interactions in the baryons and the nucleon
wave functions obtained from the solution of
the semirelativistic three-body Schr\"odinger equation. We show
that there is no appreciable diquark clustering in the nucleon
and that the effective meson-exchange interaction, which is
adjusted to describe the baryon spectrum \cite{GPVW},  does not bind
the scalar diquark nor the nucleon. However, when this interaction
is combined with the confining interaction, one finds
a bound diquark
but with a mass above the two-quark threshold and
very similar in magnitude to that
obtained recently in lattice QCD  \cite{HES}.
Nevertheless, as soon as the strength of the effective meson-exchange
interaction is increased, not by a very big amount, it alone binds
a nucleon, even without a confining force.
While the contributions from the confining interaction to the nucleon
mass are not small,
the nucleon size, calculated with the confining interaction alone
and in a full model that includes both confinement and
effective meson exchange, is  different. It is substantially
smaller in the latter case, showing that there is indeed a soft interval
between the  scale when confinement becomes active, and the scale
where  chiral physics starts to work. However, for excited baryon
states, which are much bigger in  size, the role of confinement
increases.

\section{ How iteration in the t-channel
 of the instanton-induced interaction
leads to a meson-exchange picture and
 (anti)screens the short-range
behaviour.}

It has been shown in  recent years that a successful
explanation of light and strange baryon spectroscopy,
especially the correct ordering of the lowest states with
positive and negative parity, is
achieved if the hyperfine interaction between constituent
quarks $i$ and $j$ has a short-range behaviour
which reads schematically  \cite{GR}:

\begin{equation}
-\vec{ \lambda}_{i}^{F}
\cdot \vec{\lambda}_{j}^{F}
\vec{\sigma}_i \cdot \vec{\sigma}_j,
\label{GBE}
\end{equation}

\noindent
where $\lambda^F$ is a set of a flavor Gell-Mann matrices
for $F=1,...,8$ and $\lambda^0 = \sqrt{2/3}{\bf 1}$. This
interaction is supplied by the short-range parts of
Goldstone boson exchange (GBE)
\footnote{ $\pi$, $K$
and $\eta$ exchanges; due to the axial anomaly the $\eta'$
is not a Goldstone boson, but in the large $N_c$ limit it
also becomes a Goldstone boson, and thus the coupling
of $\eta'$ to a constituent quark should be essentially different
from that of octet mesons.},
vector-meson-like exchange and/or correlated two-pseudoscalar-meson-like
exchange \cite{GLOZ}, etc.

It is  sometimes stated that the instanton-induced
't Hooft interaction in $qq$ pairs could also provide a good baryon
spectrum  as it contains
a flavor- and spin-dependence and, iterated  in the $qq$
s-channel, produces a deeply bound scalar diquark which makes
the nucleon lighter than the $\Delta$ \cite{RAPP,SHURYAK}.
A similar picture of a deeply bound scalar diquark has been advocated
 in a generalized Nambu and Jona-Lasinio (NJL) model
\cite{VW,AR}. Then a baryon is constructed as an additive
diquark-quark system  or by solving ``relativistic
diquark-quark Faddeev equations'' that take into account the
quark exchange between the diquark and quark-spectator \cite{AR,BENTZ}.
In this section we show that such a  picture
of baryons, based on the iteration of the local 4-fermion
interaction in the $qq$ s-channel is only a small part of a more
general picture, based on the meson-exchange interaction. The reason
is that when the 't Hooft interaction (or generalized NJL one)
 is first iterated in the $qq$ t-channel, it  inevitably leads to
the effective meson-exchange between constituent quarks,
which is drastically
different  from the initial (not iterated) 4-fermion
local interaction due to (anti)screening effects. The difference is
not only in the flavor- and spin-dependence, but  sometimes also in the
sign of the interaction.

To demonstrate  this we  use a simple $2\times2$
't Hooft-determinant interaction
for two light flavors (u and d), neglecting
for the simplicity the tensor coupling term, which is
suppressed by the factor
$\frac{1}{4N_c} = \frac{1}{12}$
 \cite{DIAKONOV}. We also assume  zero masses
for the current u and d quarks in this section.
 For our illustrative purposes
such an approximation is justified. This Hamiltonian reads:

\begin{equation}
H=-G[(\bar{\psi}\psi)^2 +(\bar{\psi}i \gamma_5 \vec{\tau} \psi)^2
-(\bar{\psi} \vec{\tau} \psi)^2 - (\bar{\psi}i \gamma_5  \psi)^2].
\label{HOOFT}
\end{equation}

\noindent
The {\it dimensional} strength of the interaction $G$ as well as
the ultraviolet
cut-off scale $1/r_0$ can be related to parameters of the
instanton liquid \cite{DIAKONOV,SHURYAK}
(the dimensionless coupling constant is given by $G/4\pi r_0^2$).
The interaction (\ref{HOOFT})
is attractive in the scalar-isoscalar $\bar{q} q$ channel (the first
term), leading to  chiral symmetry breaking, or, which is
related, to a  massive $\sigma$-meson field and
the constituent mass $m$ of quarks.
This is readily obtained from the Schwinger-Dyson (gap)
equation for a quark Green function in the Hartree-Fock approximation.
The interaction in the $\bar{q}q$ pseudoscalar-isovector
channel is driven by the second term of (\ref{HOOFT}).
 It is so strong, that when it is iterated in the
$\bar{q}q$ s-channel by solving the Bethe-Salpeter equation,
see Fig. 1, it exactly compensates the $2m$-energy, supplied by the
first term in (\ref{HOOFT}), and thus there appear $T,J^P
=1,0^-$ mesons with zero mass as  deeply bound relativistic
$\bar{q}q$ systems - Nambu-Goldstone bosons. The nonzero mass
of the pseudoscalar mesons is brought about by the nonzero
 current quark mass as a perturbation, which is well
illustrated by the current algebra results
(Gell-Mann-Oakes-Renner relations). The first
two terms in the Hamiltonian (\ref{HOOFT}) form in fact
the classical NJL Hamiltonian \cite{NJL} and the statement
above is a theorem, proved by Nambu and
Jona-Lasinio many years ago. This scenario holds if the
fixed strength of the interaction $G$ exceeds some critical
level. In a more sophisticated derivation \cite{DIAKONOV}
the strength of the interaction $G$ is not fixed and should
be determined after one gets the chirally broken phase.

The Hamiltonian (\ref{HOOFT}) does not contain any
interaction in $\bar{q}q$ pairs with vector meson
quantum numbers. So, according to
the scenario above, the masses of vector mesons, $\rho$
and $\omega$, should be approximately $2m$, which is
well satisfied empirically. Thus, it cannot be overemphasized
that the $\pi-\rho$ mass splitting is brought about not by the
perturbative color-magnetic interaction between nonrelativistic
constituent quarks\footnote{It is also important  to remember
that the pion is not a simple  nonrelativistic two-body system,
but a purely relativistic
${\bar q}q$ system and its
Nambu-Goldstone boson nature (zero mass in the chiral limit)
cannot be obtained from a
nonrelativistic reduction of the second term in (\ref{HOOFT})
used in the Schr\"odinger equation.},
but by the detailed balance between the first and
second terms in (\ref{HOOFT}), which is determined exclusively
by the demand that the   gluonic interaction between
current quarks must satisfy chiral $SU(2)_L \times SU(2)_R$
symmetry\footnote{The interaction (\ref{HOOFT}) is color-independent.
One can, of course, rewrite  this interaction
using the Pauli principle in terms of  linear combinations
of different operators, like ${\bf 1}$, ${\bf color \cdot color}$,
${\bf spin \cdot spin}$, ${\bf color \cdot color~ spin \cdot spin}$,
${\bf isospin \cdot isospin}$,... The presence of the
${\bf color \cdot color~ spin \cdot spin}$ structure in this decomposition
does not mean that
the interaction (\ref{HOOFT}) becomes similar in its effect
to the color-magnetic
component  of the one gluon exchange interaction, which is
explicitly color-dependent. It is like
an identity $a = (a-b) +b$ does not mean that effect of $b$
is contained in $a$.}.
 An important question, which is actively debated
nowdays, is which particular {\it nonperturbative} gluonic
configurations in QCD, e.g. instantons, or abelian monopoles,
or other topological configurations, are intrinsically
responsible for the chiral symmetry breaking.

Among other attractive features of the instanton-induced
interaction (\ref{HOOFT}) is that it automatically solves
the $U(1)_A$ problem, giving a much bigger mass to the
pseudoscalar flavor-singlet (in the present 2-flavor
formulation that is isosinglet) meson $\eta'$ \cite{THOOFT}.
This is because of the last term in (\ref{HOOFT}). Only
this term contributes  in a
pseudoscalar flavor-singlet
quark-antiquark pair. Since this interaction is repulsive,
the $\eta'$ becomes heavy, contrary to $\pi$. We note in
passing that the color-magnetic interaction cannot explain
this big $\eta'-\pi$ mass splitting.

Clearly,  the simple Hamiltonian (\ref{HOOFT}) is only
some part of a more complicated physical situation. For
instance, one definitely needs some additionl attractive
interaction, e.g. confinement, otherwise the $\eta'$ meson
or vector mesons will be unbound, while the octet pseudoscalar
mesons are probably not affected  by the long-range
confining interaction.

Having mentioned all the positive features of the Hamiltonian
(\ref{HOOFT}) in the quark-antiquark system, we are now
going to discuss its implications in quark-quark systems,
i.e. in baryons. What is typically done is a Fierz-rearrangement
of the Hamiltonian (\ref{HOOFT}) into diquark $qq$ channels
\cite{RAPP,SHURYAK} (or, similarly, a Fierz-rearrangement
of the generalized NJL Hamiltonian into diquark channels
\cite{VW,AR}). Then the diquark Hamiltonian is iterated in the $qq$
s-channel, see Fig. 2. The interaction in the scalar
$T,J^P = 0,0^+$ diquark turns out to be attractive and
it produces a deeply bound scalar diquark\footnote{
In the first calculation
\cite{DFL} the scalar diquark was not bound for $N_c=3$.}.

However, as soon as the Hamiltonian (\ref{HOOFT}) is
iterated first in the $qq$ t-channel, see Fig. 3, it
implies  irreducible (for the $qq$ s-channel) pion- and
sigma-exchange interactions between quarks\footnote{We do not
show in Fig. 3 a lot of possible chains of bubbles which
would correspond to the irreducible two-meson-exchange with
crossed meson lines, three-meson-exchange, etc.}.
 This statement
comes about as a theorem since the iteration of the
Hamiltonian (\ref{HOOFT}) in $qq$ t-channel is equivalent
to its iteration in $\bar{q}q$ s-channel. Clearly
the set of  diagrams in Fig. 3 contains all the diagrams
of Fig. 2, but in addition it contains  many others,
and the effect of these additional diagrams
is so important that the physics implied by  Fig. 2
and Fig. 3 is drastically different\footnote{Sometimes
the Hamiltonian (\ref{HOOFT}) is applied in baryons
in the framework of the chiral quark-soliton model \cite{DPP}.
In this case  quark-quark correlations through
the self-consistent chiral {\it   mean field} and quantization of its
rotation take into account
 some part of the iterations in s-channel of
Fig. 2 and do not take into account the t-channel ladders of Fig. 3.}.

A simple example of the different physical implications
is that  Fig. 3 suggests a long-range meson-exchange
Yukawa tail, which is crucial for the interaction of
quarks, belonging to different nucleons, while if
the picture of Fig. 2 were correct the nuclear force
would be absent. Another evident difference is that
according to the Hamiltonian (\ref{HOOFT}) and Fig. 2
the interaction is absent in  flavor-symmetric, $T=1$,
quark pairs \footnote{I.e. the hyperfine
interaction is absent in the $\Delta$-resonance and its excitations.
If that were the case, the positive parity state $\Delta(1600)$,
which belongs to the $2\hbar\omega$ shell because of its
positive parity, would be approximately $\hbar\omega \simeq
500$ MeV above the negative parity pair $\Delta(1620) -
\Delta(1700)$.}, while the $qq$ interaction of Fig. 3
does not vanish in this case.

Less evident is that even the  ''short-range'' interaction
between quarks is crucially modified in Fig. 3
as compared to Fig. 2. We call it the ``(anti)screening effect''
and   illustrate it below \footnote{The subsequent qualitative
discussion will be extended and published in detail elsewhere
\cite{PREP}.}.

In order to see it one should avoid the Fierz-rearrangement
of (\ref{HOOFT}) into a diquark Hamiltonian. Instead, one
can use the initial Hamiltonian (\ref{HOOFT}), but assume
that all initial, intermediate and final state $q_i q_j$
wave functions are explicitly antisymmetric.

Consider
the first term of (\ref{HOOFT}). In the Nambu-Goldstone
mode of chiral symmetry a fermion field has a large
dynamical (constituent) mass $m$. Using a $1/m$
expansion, one obtains that to leading order ($m^0$)
 the first term of (\ref{HOOFT}) leads to
a $\delta$-function type attraction in all quark pairs allowed  by Pauli
principle:

\begin{equation}
-G(\bar{\Psi}\Psi)^2 \Longrightarrow V({\vec r}_{ij})
=- 2G \delta({\vec r}_{ij}).
\label{FIRST}
\end{equation}

\noindent
The effect of the third term in (\ref{HOOFT}) to the same
order is

\begin{equation}
G(\bar{\Psi}\vec{\tau}\Psi)^2 \Longrightarrow V({\vec r}_{ij})
=2G \vec{\tau}_i \cdot \vec{\tau}_j \delta({\vec r}_{ij}).
\label{THIRD}
\end{equation}

\noindent
The potentials (\ref{FIRST}) and (\ref{THIRD}), combined
together, produce

\begin{equation}
 V({\vec r}_{ij})
=-2G (1-\vec{\tau}_i \cdot \vec{\tau}_j) \delta({\vec r}_{ij}).
\label{COMB}
\end{equation}

\noindent
Note that at this order the second and  fourth terms
of (\ref{HOOFT}) do not contribute. The potential (\ref{COMB})
suggests a strong attraction in the isospin-zero quark pair,
and no interaction  in $T=1$ quark pairs. Assuming relative
angular momentum $L=0$ within the $T=0$
quark pair the Pauli principle implies that the spins of the quarks
should be antiparallel, $S=0$. When the theory is sensibly
regularized the delta-function attraction is smeared
out over the instanton size $r_0$

\begin{equation}
\delta(\vec r)\rightarrow \frac{1}{4\pi r_0^2}
\frac{e^{- r/r_0}}{r}.
\label{DELTA}
\end{equation}

\noindent
This substitution arises from a replacement of the static
Green function of the infinitely heavy particle in (\ref{HOOFT})

\begin{equation}
G_{\mu = \infty}({\vec x} - {\vec y}) = - r_0^2 \delta
({\vec x} - {\vec y}),
\label{heavy}
\end{equation}

\noindent
by the Green function of a particle with mass $\mu = 1/r_0$

\begin{equation}
G_{\mu = 1/r_0}({\vec x} - {\vec y}) = - \frac{1}{4\pi}
\frac{e^{-\mid{\vec x} - {\vec y}\mid/r_0}}{\mid{\vec x} - {\vec y}\mid}.
\label{INST}
\end{equation}

When the strength of the interaction is big enough, the
potential (\ref{COMB})-(\ref{DELTA}), iterated by solving the
semirelativistic Schr\"odinger
equation (i.e. when the kinetic energy operator is taken in
a relativistic form) can produce a deeply bound scalar diquark, in agreement
with \cite{RAPP,SHURYAK}. Indeed, when one takes the strength
$G=490\frac{1}{8N_c^2}$ GeV$^{-2}$, $N_c =3$,
with the instanton size
$r_0$ between 0.3 and 0.35 fm  and the constituent
mass $m=340-400$ MeV \cite{RAPP,SHURYAK} one  finds a very deeply bound diqurk.

 In the illustration above we have used
a simplified but transparent nonrelativistic picture that
adequately reflects in the present case the essential features
of a more rigorous Bethe-Salpeter approach.

Sometimes the potential (\ref{COMB}) is applied to explain
the hyperfine splittings in baryons \cite{SR,METSCH}. While
it can  generate the $\Delta - N$ mass splitting,
it fails to explain  the lowest levels with positive and
negative parity because it does not contain the necessary
spin-isospin dependence (\ref{GBE}). It will become evident from
the discussion below that such an interpretation of the role of
instantons in baryons does not survive as soon as the wider
class of diagrams in Fig. 3 is considered.

What happens  when the first term in (\ref{HOOFT}) is
iterated in the $qq$ t-channel? The corresponding
amplitude is

\begin{equation}
T_S(q^2) = 2G + 2G J_S(q^2) 2G +... = \frac{2G}{1-2G J_S(q^2)},
\label{ITER}
\end{equation}

\noindent
where $J_S(q^2)$ is the  loop integral
(bubble) with the scalar vertex which represents vacuum
polarization in the scalar channel. The eq. (\ref{ITER})
defines ``running amplitude'' and a negative sign in the
denominator implies its antiscreening behaviour.
The expression
(\ref{ITER}) is known to have a pole at $q^2 = 4m^2$
\cite{NJL}, which can be identified with the exchange by
scalar meson $\sigma$ with the mass $\mu_\sigma = 2m$
in the chiral limit. The coupling constant of the $\sigma$-meson
to constituent quark can be obtained as a residue of
(\ref{ITER}) at the pole

\begin{equation}
\frac{g_{\sigma q}^2 }{q^2-\mu_\sigma^2} = -\frac{2G}{1-2G J_S(q^2)}.
\label{POLE}
\end{equation}

\noindent
 Expanding
 the $\bar \Psi \sigma \Psi$ vertex in $1/m$, one obtains
to leading order $(m^0)$ the following well-known sigma-exchange
potential

\begin{equation}
 V_\sigma({ r}_{ij})
=-\frac{g^2_{\sigma q}}{4\pi} \frac{e^{-\mu_\sigma { r}_{ij}}}
{{r}_{ij}}.
\label{SIGMA}
\end{equation}

 The equivalence
between the t-channel ladder of bubbles in Fig. 3
beyond the $\sigma$-meson pole in the t-channel and
the meson-exchange diagram is achieved
only when some form factor $F_{\sigma q}(q^2)$ is inserted
into the meson-quark vertex, i.e. the left hand side
of eq. (\ref{POLE}) should be multiplied with
$F^2_{\sigma q}(q^2)$. The form factor is to be normalized
$F_{\sigma q}(q^2= \mu_\sigma^2) = 1$.

 In principle the eq. (\ref{POLE}) allows to obtain
a functional form for such a form factor. However, it will
be very far from reality because the toy model (\ref{HOOFT})
does not contain confinement, which should be important
for the interaction between quark and antiquark in the
weakly bound system like $\sigma$-meson (note that its mass
is just at the ``continuum threshold'' $2m$). In this situation
the best way is to rely on our general understanding of
the low-energy effective theory. Both constituent quarks
and chiral meson fields as well as their couplings make a sense
only in the Nambu-Goldstone mode of chiral symmetry.
When momentum transfer at the meson - quark vertex
exceeds the chiral symmetry breaking scale
$\Lambda_\chi$ ( which within all NJL-like models
coincides with the regularization scale $1/r_0$)
the effective theory should be
cut off. This cut off is accomplished by a form factor
in the meson - constituent quark vertex and should
be related to the internal structure of both quasiparticles.
But in any case the scale parameter in this form factor should
be comparable with $\Lambda_\chi$. At high momenta one can
use neither constituent quark nor chiral fields and original
quark-gluon degrees of freedom should be used instead.

Approximating this form factor by

\begin{equation}
F_{\sigma q}^2(q^2) =
\frac{\Lambda^2_\sigma - \mu_\sigma^2}{\Lambda^2_\sigma - q^2},
\label{FORM}
\end{equation}
 instead of the potential (\ref{SIGMA}) we arrive at

\begin{equation}
 V_\sigma({ r}_{ij})
=-\frac{g^2_{\sigma q}}{4\pi}\left( \frac{e^{-\mu_\sigma { r}_{ij}}}
{{r}_{ij}} -  \frac{e^{-\Lambda_\sigma { r}_{ij}}}
{{r}_{ij}}\right).
\label{SIGFOR}
\end{equation}

\noindent
Note, that any  functional form of form factor
leads to a similar suppression of the potential at
short range but it does not influence its long-range
part which is determined exclusively by the position
of the pole. If one takes a dipole form factor
the suppression will be stronger.

What is the  fate of the third term in (\ref{HOOFT}), when it is
iterated in the $qq$ t-channel? In this case one obtains
the following amplitude

\begin{equation}
T_S^{ab}(q^2)= -\left( 2G - 2G J_S(q^2) 2G +...\right) \delta_{ab}
= - \frac{2G}{1+2G J_S(q^2)} \delta_{ab},
\label{ITER2}
\end{equation}

\noindent
where $a,b$ are isospin indices.
The positive sign in the denominator indicates screening. For
instance, at $q^2 = 4m^2$ the strength of the interaction is
reduced by the factor 2 versus a bare vertex. Still, this
suppression of the interaction at low momenta is not realistic,
because the toy model (\ref{HOOFT}) does not contain confinement
and thus there is only a repulsion in the scalar-isovector quark-antiquark
system.
When confinement is added in the quark-antiquark pairs, there appear
heavy scalar-isovector mesons and the sign of the
amplitude (\ref{ITER2}) becomes opposite at small momenta! This
low-momentum amplitude corresponds to the exchange by
scalar-isovector mesons between quarks.
The corresponding meson-exchange interaction is
 similar in form to (\ref{SIGFOR}), but with an additional
factor $\vec \tau_i \cdot \vec \tau_j$.   The expectation value of
the operator $\vec{\tau}_i \cdot \vec{\tau}_j$
in the scalar diquark is
$-3$  and thus the interaction (\ref{COMB})
is stronger by the factor 4 through the interaction (\ref{THIRD})
in the picture of Fig. 2. In contrast, in the picture of Fig. 3 the
contributions from the scalar and scalar-isovector meson exchanges
tend to cancel each other.

Thus we see that the initial interaction is screened.
This screening means that  the interaction
(\ref{COMB}) becomes  weaken and that
its isospin dependence is modified.
It is  trivial to check that the attraction (\ref{SIGFOR})
does not lead to a bound scalar diquark with any reasonable coupling
constant, sigma-meson mass, cut-off mass $\Lambda_\sigma$ and
constituent quark mass (see discussion in the next chapter).
The scalar-isovector meson exchange
will further reduce this attraction, though the coupling
constant of the scalar-isovector mesons to constituent quarks
will be essentially smaller.

Both the scalar-isoscalar exchange and scalar-isovector
exchanges between constituent quarks do not contain the
 flavor-spin dependence  (\ref{GBE})
 which is necessary for baryon spectroscopy\footnote{
We do not state, however, that such an interaction
is unimportant. Just the opposite, the $\sigma$-exchange is known
to be very important for the medium-range attraction in the NN
system and it also contributes to binding nucleon.
 However it only has
a small influence on the splittings via different radial behaviour
of  baryon wave functions.}.

Now we shall extend our $1/m$ expansion of the Hamiltonian
(\ref{HOOFT}) to the next-to-leading order, taking into
account terms $m^{-2}$. The first and  third terms of
(\ref{HOOFT}) will give at this order the spin-orbit forces,
as well as some small corrections to the interactions
(\ref{FIRST}) and (\ref{THIRD}).
 The second and  fourth terms generate, however,
a flavor-spin dependent interaction. Consider the second
term in (\ref{HOOFT}). It gives both the spin-spin and
tensor force components. We ignore below the tensor force
as it is irrelevant to our simple discussion and
for the $L=0$ $qq$ pair. Then:

\begin{equation}
-G(\bar{\Psi}i\gamma_5\vec{\tau}\Psi)^2
\Longrightarrow V({\vec r}_{ij})
=2G \frac{1}{12m^2}\vec{\sigma}_i \cdot \vec{\sigma}_j
\vec{\tau}_i \cdot \vec{\tau}_j \Delta\delta({\vec r}_{ij}).
\label{SECOND}
\end{equation}

\noindent
Again, assuming that the instanton has a finite size $r_0$,
the potential (\ref{SECOND}) reads:

\begin{equation}
 V({\vec r}_{ij})
=\frac{2G}{4\pi r_0^2} \frac{1}{12m^2}\vec{\sigma}_i \cdot \vec{\sigma}_j
\vec{\tau}_i \cdot \vec{\tau}_j
\left(\frac{1}{r_0^2} \frac{e^{-r_{ij}/r_0}}{r_{ij}} -
4\pi\delta({\vec r}_{ij})\right).
\label{SECMOD}
\end{equation}

Let us now iterate the second term of (\ref{HOOFT}) in the $qq$
t-channel

\begin{equation}
T_P^{ab}(q^2) = \left(2G + 2G J_P(q^2) 2G +...\right)\delta_{ab} =
\frac{2G}{1-2G J_P(q^2)} \delta_{ab},
\label{ITERP}
\end{equation}

\noindent
where $J_P(q^2)$ is a bubble  with a pseudoscalar vertex
(vacuum polarization in the pseudoscalar channel).
There is a pole at $q^2=0$
 in (\ref{ITERP}) in the chiral
limit, which can be identified as a pion-exchange
(beyond the chiral limit it is shifted
to a physical pion mass $q^2=\mu_\pi^2$.) The coupling constant
of pion to constituent quark can be obtained as a residue
of (\ref{ITERP}) at the pole

\begin{equation}
\frac{g_{\pi q}^2 }{q^2} = -\frac{2G}{1-2G J_P(q^2)}.
\label{POLEP}
\end{equation}

\noindent

Thus near the pole (\ref{ITERP}) - (\ref{POLEP}) represents
a pion-exchange potential between quarks, which
in the chiral limit, $\mu_\pi =0$, at the order $1/m^2$
(omitting the tensor force component)
is:

\begin{equation}
V_\pi({\vec r}_{ij})
=-\frac{g_{\pi q}^2}{4\pi} \frac{1}{12m^2}\vec{\sigma}_i \cdot \vec{\sigma}_j
\vec{\tau}_i \cdot \vec{\tau}_j 4\pi\delta({\vec r}_{ij}).
\label{PION}
\end{equation}

The difference between (\ref{SECOND}-\ref{SECMOD}) and (\ref{PION}) is obvious:
the interaction (\ref{PION}) is much stronger.\footnote{One can easily see
it from comparison of $<\Psi_0 | \Delta \delta(\vec r) | \Psi_0>$
and $<\Psi_0 |  \delta(\vec r) | \Psi_0>$ where $\Psi_0$
is a zero order function stemming from confinement.} A source of
this enhancement is also obvious: near the pole the original bare
interaction
$2G$ becomes strongly reinforced \footnote{In essense this
antiscreening is some kind of asymptotic freedom: at space-like momenta
$q^2 \rightarrow -\infty$ the interaction is represented by
a bare vertex $2G$, but at $q^2 \rightarrow 0$ it becomes
infinitely enhanced in the channel with Goldstone boson exchange
quantum numbers.}. The pion pole is located just
near the space-like region and thus strongly influences the
quark-quark interaction at not very high momentum transfer.

 Again, to retain
the equivalence between the t-channel ladder of bubbles
in Fig. 3 and the pion-exchange diagram beyond the pole,
one must insert a form factor into the $\pi q$ vertex. The effect
of this form factor is to smear out the $\delta$-type
interaction in (\ref{PION}) over the region $1/\Lambda_{\pi q}$.
If this form factor is choosen in the form (\ref{FORM}),
then one obtains

\begin{equation}
V_\pi({\vec r}_{ij})
=-\frac{g_{\pi q}^2}{4\pi} \frac{1}{12m^2}\vec{\sigma}_i \cdot \vec{\sigma}_j
\vec{\tau}_i \cdot \vec{\tau}_j \Lambda_{\pi q}^2
\frac{e^{-\Lambda_{\pi q}r_{ij}}}
{r_{ij}}.
\label{PIONSM}
\end{equation}

The $m^{-2}$  expansion of the fourth term of
the Hamiltonian (\ref{HOOFT}) will give a result similar to
second term, without, however, isospin-dependent
factor and with the opposite sign.
Its iteration
in the $qq$ t-channel will produce screening
effects as it is repulsive in the ${\bar q} q$ s-channel. When,
however, this term is combined with an additional
attractive interaction, e.g. confinement, it will give
$\eta'$. Then the iteration in the $qq$ t-channel will
imply  $\eta'$-exchange between quarks. The latter
interaction is similar to (\ref{PION}), except that
the factor ${\vec \tau}_i \cdot {\vec \tau}_j$ is not
present and that in this case there appears a
Yukawa part of the potential because the mass of $\eta'$
is not zero in the chiral limit.

 The discussion above  suggests
that while for the picture of Fig. 2 the most important interaction
is (\ref{COMB}) and the interaction (\ref{SECOND}) is only some
very small correction to it, in the case of Fig. 3 the most
important interaction in baryons becomes (\ref{PION}) and the
one of (\ref{SIGFOR})  only plays a  modest role for splittings.
This is a consequence of an antiscreening. The antiscreening implies that
if a typical momentum transfer in the meson-quark vertex
(which in qq systems is of the same order as momentum of quarks)
is below the chiral symmetry breaking scale, then
 the original (bare) quark-quark vertex in the pseudoscalar channel is
strongly reinforced by the pole
which occurs when one iterates it in the t-channel.
These pole contributions represent the Goldstone boson exchange
interactions between constituent quarks in the Nambu-Goldstone
mode of chiral symmetry. Only at a rather high momentum
transfer (i.e. very far from the poles) there should appear
a sensitivity to the original (bare)
quark-quark vertex. In the latter case the constituent
quarks and chiral fields cannot be used as effective
degrees of freedom. So the crucial question is what  a
typical momentum transfer in the given system is. In the low-lying
baryons it is below the chiral symmetry breaking scale
thus justifying a use of the effective qq interactions there
\cite{GL}.

We hope that the discussion above has been transparent
enough to show a dramatic difference between the initial
't Hooft interaction, taken literally in $qq$ system,
and its implication after iteration in the t-channel, producing
meson exchange between constituent quarks.

In fact, what one needs for the chiral symmetry breaking
is a scalar interaction between quarks. Any pairwise
gluonic interaction between quarks in the local approximation
will necessarily contain the first and second terms of (\ref{HOOFT})
with fixed relative strength. This is because of the chiral
invariance. Thus all our conclusions are rather general and
do not rely necessarily on 't Hooft interaction.
An important
lesson is to see how this nonperturbative gluonic interaction,
which induces the dynamical breaking of chiral symmetry, suggests
an explanation of both the low-lying mesons and at the same time
of baryons and the nuclear force through the effective meson exchange
picure in $qq$ systems.
Among the various applications of this idea, will be to work out
how the meson-exchange interaction  shifts the transition
point from the chiral symmetry broken phase to the
color-superconductor phase.

We also mention a recent lattice study \cite{LIU} which shows
directly that the hyperfine $\Delta - N$ splitting is mostly
due to the meson-exchange interaction between quarks. Another
indirect evidence in favor of the picture in Fig. 3 versus that
 in Fig. 2 is that after cooling (the cooling means that
all gluonic configurations, except for instantons, are
removed) the $\Delta -N$ splitting disappears \cite{NEGELE}.
While the cooling does not affect the initial 't Hooft
interaction between quarks and thus the whole s-channel
ladder of Fig. 2 is active, it ruins the t-channel ladder
of Fig. 3. The reason is that there are not enough antiquarks
in the Fock space after cooling as  in quenched approximation
they are mostly produced by different gluons, including
perturbative ones, attached to valence quark lines (Z graphs).

\section{Are the diquark and nucleon bound by the meson-exchange
interaction?}

We start this section with a short description of the effective
meson-exchange interaction model, adjusted
to describe baryon spectroscopy within an exact semirelativistic
3-body formulation \cite{GPVW}. The
Hamiltonian of  ref. \cite{GPVW} reads:

\begin{equation}
\label{htot}
H=\sum_{i=1}^3\sqrt{\vec{p}_i{}^2+m_i^2}+\sum_{i<j=1}^3V_{ij},
\end{equation}

$$ \sum_{i=1}^3{\vec p}_i = 0.$$

\noindent
Here the relativistic form of the kinetic-energy operator is used, with
$\vec{p}_i$ the 3-momentum and $m_i$ the masses of the constituent quarks. The
dynamical part consists of the quark-quark interaction

\noindent
\begin{equation}
V_{ij}=V_{\chi}+V_{conf}.
\end{equation}

\noindent
The linear pairwise confining potential

\begin{equation}
V_{conf}(r_{ij})=V_0+C r_{ij},
\label{conf}
\end{equation}

\noindent
\noindent
includes both the color-electric string $Cr_{ij}$ with the
color factor absorbed into the string tension $C$ as well as a constant
$V_0$, which is large and negative, and
thus effectively includes all possible spin- and flavor-independent
attractive interactions between quarks, e.g. $\sigma$-exchange
(\ref{SIGFOR}), etc. The flavor- and spin-dependent part of
the above Hamiltonian is

\begin{eqnarray}
\label{voct}
V_\chi(\vec r_{ij})  &=&
\left[\sum_{F=1}^3 V_{\pi}(\vec r_{ij}) \lambda_i^F \lambda_j^F\right.
+\sum_{F=4}^7 V_K(\vec r_{ij}) \lambda_i^F \lambda_j^F
\nonumber \\
&&\left.\raisebox{0ex}[3ex][3ex]{}+V_{\eta}(\vec r_{ij}) \lambda_i^8
\lambda_j^8 + \frac{2}{3}V_{\eta'}(\vec r_{ij})\right]
\vec\sigma_i\cdot\vec\sigma_j,
\end{eqnarray}

\begin{equation}
\label{vyuk}
V_\gamma (\vec r_{ij})= \frac{g_\gamma^2}{4\pi
\frac{1}{12m_im_j}
\left\{\mu_\gamma^2\frac{e^{-\mu_\gamma r_{ij}}}{ r_{ij}}-
\Lambda_\gamma^2\frac{e^{-\Lambda_\gamma r_{ij}}}{ r_{ij}}\right\}.
\end{equation}

\noindent
with $\mu_\gamma$ ($\gamma=\pi,K,\eta,\eta'$) being the individual
phenomenological meson masses, and
$g_\gamma^2/4\pi$ the meson-quark coupling constants.

The constituent mass of the light quarks $m=m_u=m_d$ was fixed
in \cite{GPVW} to a typical value, $m=340$ MeV, implied
by a simple static quark model formula for the nucleon magnetic
moment.  It is astonishing  that the same value has
been obtained in a lattice measurement \cite{HES}. All
other parameters of the above Hamiltonian can be found in
ref. \cite{GPVW}.

In  light quark systems, like $N$ and $\Delta$, only the
$\pi$-like, $\eta$-like and $\eta'$-like parts of the
 potential (\ref{voct}) contribute. The $\pi$-like exchange
interaction is determined by the following matrix elements:

\begin{equation}
-\vec\tau_i\cdot\vec\tau_j \vec\sigma_i\cdot\vec\sigma_j
 = \left\{ \begin{array}{llll}
-1, & {\rm if} \; S_{ij} =1, & T_{ij} =1 \\
-9, & {\rm if} \; S_{ij} =0, & T_{ij} =0 \\
 3, & {\rm if}\; S_{ij} =1, & T_{ij} =0 \\
 3, & {\rm if}\; S_{ij} =0, & T_{ij} =1,
\end{array} \!\!\right.
\label{st}
\end{equation}

\noindent
while the $\eta$- and $\eta'$-like exchanges depend only
on the spin $S_{ij}$ of a quark pair.

\noindent
Combining all $\pi$, $\eta$ and $\eta'$ interactions
one finds that the potential (\ref{voct}) is most attractive at
short distances in $S_{ij},T_{ij}=0,0$ quark pair and essentially
less attractive in the $S_{ij},T_{ij}=1,1$ diquark system. In other
possible color-antitriplet $qq$ pairs it is repulsive.

Applying the Hamiltonian (\ref{htot}) in a color-antitriplet
$qq$ system, one finds a mass $m_{00}= 744$ MeV for a
scalar diquark, $T,J^P=0,0^+$, and a mass
$m_{11}= 869$ MeV for an
axial-vector diquark, $T,J^P=1,1^+$. In both cases
the relative orbital angular momentum is $L=0$, so
the total angular momentum coinsides with the spin
of two quarks. These values are very similar to
those obtained recently from the lattice
``diquark spectroscopy'' \cite{HES}.
The root-mean-square (r.m.s.) radius of the scalar diquark
is 0.354 fm and of the axial-vector one - 0.438 fm.
These radii do not include the size of the constituent
quark.

It is evident that the confining interaction
implies a bound diquark in the sense that there are no
asymptotically free constituent quarks. So it is very
instructive to compare the mass of the above diquarks
with the unphysical two-constituent-mass threshold,
$2m=680$ MeV. The scalar
diquark mass is a few tens of MeV above the threshold,
which indicates that the meson-exchange part of the
interaction, including $V_0$, does not bind a diquark
without the confining interaction $Cr_{ij}$.
This can also be checked explicitly. To this end
we combine the spin- and isospin-dependent interaction (\ref{voct})
with the $\sigma$-exchange potential (\ref{SIGFOR})
and drop the confining potential (\ref{conf}).
The $\sigma q$ coupling constant is constrained
to be equal to the $\pi q$ one, as suggested by chiral symmetry,

\begin{equation}
\frac{g^2_{\sigma q}}{4\pi} = \frac{g^2_{\pi q}}{4\pi} = 0.67.
\end{equation}

\noindent
The sigma mass is taken to be $\mu_\sigma  \simeq  2m$,
which is implied by the well known result for all
NJL-like interactions,  $\mu^2_\sigma = 4m^2 + \mu_\pi^2$.
With these constraints we do not find a bound diquark
with any reasonable value for $\Lambda_\sigma \sim 1$ GeV.
Only with  $\Lambda_\sigma > 3$ GeV does a weakly
bound scalar diquark appear. If one increases the
$\frac{g^2_{\sigma q}}{4\pi}$
coupling constant by a factor 1.5, but keeps the $\pi q$
coupling constant,
then we obtain a bound
diquark only at  $\Lambda_\sigma > 1.6$ GeV.
Thus we conclude that the meson-exchange interaction itself
does not bind a diquark.

The next question we address in this section is whether the
meson-exchange interaction binds nucleon itself, without
confinement. A-priori one cannot exclude the possibility
that while the diquark
is unbound the three quark system will be bound because of
genuine 3-body effects (compare, e.g.,
the binding energy of tritium and deuteron). Indeed,
a full model, including confinement (\ref{conf}), produces a
nucleon mass which is below the three constituent mass threshold,
$3m=1020$ MeV. Hence the positive contribution from the rising
potential $Cr_{ij}$, 631 MeV, is not big  compared
to the negative contribution
from $3V_0=-1248$ MeV in combination with the
negative contribution of the
spin-dependent part of interaction, -750 MeV.

Superficially one could thus conclude that the meson-exchange part of
the Hamiltonian could bind nucleon without any support from confinement.
However, such an interpretation  cannot be taken
for two reasons. Firstly, we do not know which
part of the negative constant $V_0$ comes from the $\sigma$-exchange,
and which - from the genuine color-electric confinement, because the
$Y$-shape of the gauge-invariant 3-body confining interaction
can be approximated by a sum of  pairwise potentials only when
some additional constant contribution is added. Secondly, a perfect
fit of the baryon spectrum with a quality similar to that
in ref. \cite{GPVW} can be obtained with a constituent mass
smaller than $m_N/3$. So we have performed a direct calculation
of the nucleon, replacing the potential (\ref{conf}) by the
$\sigma$-exchange potential  (\ref{SIGFOR}). We have found that
for  $\Lambda_\sigma \leq 1800$ MeV the nucleon is unbound and becomes
bound at higher values of $\Lambda_\sigma$. If one increases the
$\frac{g^2_{\sigma q}}{4\pi}$ by a factor 1.5, then the nucleon
becomes bound for   $\Lambda_\sigma > 1200$ MeV. These results
indicate that while the nucleon is unbound with the meson-exchange
potential parameters fixed of ref. \cite{GPVW}, it could be bound
as soon as a spin- and isospin-independent $\sigma$-like
exchange interaction and/or spin- and isospin-dependent interactions
are made stronger, not by a big amount.
It is  evident that a description
of all excited states demands the presence of  confinement
because all these states are much above the $3m$ threshold.

\section{Is there diquark clustering in the nucleon?}

 We shall use the following
set of Jacobi coordinates and a coupling scheme with self-evident notation:

\begin{equation}
\vec \rho =  {\vec r}_1 -  {\vec r}_2; ~
\vec \lambda =  {\vec r}_3 - \frac{ {\vec r}_1 + {\vec r}_2}{2},
\end{equation}

\begin{equation}
{\vec S}_{12} = {\vec S}_{1} + {\vec S}_{2}; ~
{\vec S} = {\vec S}_{12} + {\vec S}_{3},
\end{equation}

\begin{equation}
{\vec L} = {\vec L}_\rho + {\vec L}_\lambda,
\end{equation}

\begin{equation}
{\vec J} = {\vec L} + {\vec S},
\end{equation}

\begin{equation}
{\vec T}_{12} = {\vec T}_{1} + {\vec T}_{2}; ~
{\vec T} = {\vec T}_{12} + {\vec T}_{3}.
\end{equation}

Let $P_{S_{12}T_{12}}$  be a projector onto a
subspace with a given value of spin $S_{12}$ and
isospin $T_{12}$ of the particles 1 and 2. The probability
density for finding particles 1 and 2 in a spin-isospin state
$S_{12}T_{12}$ at a relative distance $r_{12}$ is given
by

\begin{equation}
g_{S_{12}T_{12}}(r_{12}) =
< \Psi |P_{S_{12}T_{12}} \delta(\rho - r_{12}) | \Psi>,
\end{equation}

\noindent
where $\Psi$ is an antisymmetric 3-body baryon wave function.
One can similarly
define the probability density for finding  the particle 3
at a
distance $r_{12,3}$
from the center of mass of particles 1 and 2

\begin{equation}
f_{S_{12}T_{12}}(r_{12,3}) =
< \Psi |P_{S_{12}T_{12}} \delta(\lambda - r_{12,3}) | \Psi>.
\end{equation}

\noindent
Then one can calculate the corresponding moments

\begin{equation}
<r_{12}^k> = \int dr_{12} r_{12}^k g_{S_{12}T_{12}}(r_{12}),
\end{equation}

\begin{equation}
<r_{12,3}^k> = \int dr_{12,3} r_{12,3}^k f_{S_{12}T_{12}}(r_{12,3}).
\end{equation}

In  Table 1 we present the $k=2$ moments
for $N$ and $\Delta$ in two cases: (i) full model,
(ii) no spin-dependent
interaction at all (i.e. only confinement is active).

Comparing the nucleon r.m.s. radius, $\sqrt{<r_N^2>}$ = 0.304 fm,
with the radius of a scalar diquark, 0.354 fm, we can deduce
the role of genuine 3 body effects - they make the nucleon essentially
more compact than the diquark.

The empirical mean square charge radius of the proton, $0.86^2$ fm$^2$,
consists of a few contributions: the contribution from the mean square
matter radius above, the charge mean square radius of the constituent
quark, the meson exchange current contribution \cite{HELM,BAR}, the proton
anomalous magnetic moment contribution, etc. The rather small
value of the matter radius, obtained above, is consistent with large
contributions from other sources. For instance, the charge radius
of the constituent quark should be mainly determined by the $\rho$-meson
pole in the time-like region (vector meson dominance) and thus
can be expected to be of the order $\sim 0.6$ fm.

The r.m.s. radius of the $\Delta$-resonance, $\sqrt{<r_\Delta^2>}$ = 0.390
fm, is larger than that of the nucleon. This result is easy
anticipate since the $\Delta$-resonance wave function does not
contain $S_{ij}=T_{ij}=L_{ij}=0$ components, where the potential
(\ref{voct}) is strongly attractive at short range, and thus
the size of the $\Delta$-resonance is
determined mainly by the weak attraction in the $S_{ij}=T_{ij}=1, L_{ij}=0$
quark pairs as well as by the confining interaction. The bigger size
of $\Delta$ has a well known experimental consequence: the $\Delta
\rightarrow N$  electromagnetic form factor falls off
 faster than the nucleon elastic one.

When the meson-exchange interaction is switched off, the nucleon
matter radius becomes larger, $\sqrt{<r_N^2>}$ = 0.442 fm.
 This illustrates that there is a
 soft gap between the scale where chiral physics starts to work and
the scale where confinement is important.

The crucial role of  three body effects can also be seen
from the comparison of the root mean square distance
between quarks in the $S_{12}T_{12} =00$ quark pair in the nucleon, 0.354 fm,
with the same distance in a free scalar diquark, 0.708 fm.
Similarly, the  three body effects
and the antisymmetrization
are responsible
for the fact that the root mean square distance in the
$S_{12}T_{12} =00$ quark pair in the nucleon, 0.354 fm,
is similar to that one in the $S_{12}T_{12} =11$ subsystem in the
nucleon, 0.387 fm,
while the potential is very different in both cases.
A comparison of the  two numbers above  gives an idea
about how unimportant  clustering is in the nucleon. It can also be
seen from Fig. 4 and Fig. 5 where we show probability
density distributions.

With a pure static ``right triangle'' 3q configuration the relation
between  $<r_{12}^2>$ and $<r_{12,3}^2>$ would be
$<r_{12,3}^2>= \frac{3}{4}<r_{12}^2>$. This relation is
almost exactly satisfied with the $\Delta$ wave function or
with the $3q$ wave function when the meson-exchange
interaction is switched off.
In the nucleon wave function there is a deviation
from this relation but it  is not large. We thus conclude that
there is no appreciable clustering in the nucleon.

What is the physical reason for the absense of a significant
clustering? The answer is that there are genuine 3-body
effects and the fermi-nature of quarks do not support
clustering. Indeed, if the quarks, say, with numbers
1 and 2 form a pair  $S_{12}T_{12} =00$, the antisymmetry
of the wave function suggests that there are at the same time
pairs with quantum numbers $S_{13}T_{13} =00$ or $S_{23}T_{23} =00$
(along with other quantum numbers). Thus a strong
attraction acts simultaneously  in all quark pairs
which makes the nucleon compact but not clustered much.
Only a much stronger and ``sharper'' interaction in the
$ST =00$ diquark would lead to an appreciable clustering,
but at a cost that $\Delta - N$ splitting will become
enormous.

\section{Summary}

Here we summarize our main conclusions.

1. The nonperturbative gluonic interaction between quarks,
e.g. instanton-induced one, which is responsible for the
dynamical breaking of chiral symmetry in  QCD  and thus
explains the $\pi - \rho$ mass splitting, iterated in the $qq$
t-channel implies a meson-exchange picture between constituent
quarks, and through the latter also explains  baryons and nuclear
force. This is a simple consequence of crossing symmetry:
if one obtains pion as a solution of the Bethe-Salpeter
equation in the quark-antiquark s-channel, then one inevitably
obtains a pion-exchange in the quark-quark systems as a result
of iterations in the $qq$ t-channel.

2. Due to (anti)screening effects the implications of this nonperturbative
gluonic interaction in $qq$ systems are drastically different when it
is  iterated only in the s-channel as compared to a more general case,
when it is first iterated in the t-channel, leading to a meson exchange,
and only after that iterated in the s-channel.

3. The effective meson-exchange interaction in $qq$ systems
does not bind diquarks without an additional confining force and
does not induce any appreciable clustering in the nucleon.

\section{Acknowledgement}

L.Ya.G. thanks D. Diakonov and D.O. Riska for  comments.
He is indebted to KEK-Tanashi and Tokyo Institute of
Technology Nuclear Theory Groups for a warm hospitality.
His work  is supported by a foreign visiting guestprofessorship
program of the Ministry of Education, Science, Sports and
Culture of Japan. Work of K.V. is supported by the
OTKA grant No. T17298 (Hungary) and
by the US Department of Energy,
Nuclear Physics Division, under contract No. W-31-109-ENG-39.

redpajama_set_name: RedPajamaArXiv


Nancy went through a rough time after losing her daughter. To deal with the depression, her doctor prescribed medication.
Nearly two years later, Nancy has a new grasp on life, a mending heart, and a strong support network. She is ready to stop taking her antidepressant medication, but she's finding it nearly impossible. She's battling headaches, insomnia, and nausea. She has no energy and overall feels terrible. In fact, she feels almost as bad as she did before she started taking the medication.
She worries she's addicted and will have to continue the drug use indefinitely. Nancy finds that extremely…depressing.
Nancy isn't alone in her depression-related struggle. Every patient who's given an antidepressant medication is warned about the potential side effects. Few, however, are made aware of the side effects of stopping the medication. Common withdrawal symptoms include the unpleasant experiences Nancy's having: fatigue, nausea, headache, and insomnia.
The side effects make it difficult to stop using the medication. Unfortunately, doctors seem unsure about what to do for these patients. Antidepressants were originally designed for short-term use. Patients were expected to take them for six to nine months. However, with a growing number of people on these drugs long-term (nearly 25 million Americans took antidepressants for at least two years, with 15.5 million on them for at least five years), doctors are finally realizing the absence of a safe plan to discontinue antidepressant use is a serious problem.
The difficulty Nancy and others experience when trying to quit antidepressants is often referred to as "discontinuation syndrome." Users don't expect this syndrome, were never warned about this syndrome, and often go back on the drug as a result of this syndrome. Other than a label for their condition, the medical field has offered little to this suffering population. The New York Times reports there are no guidelines, no customized solutions, and no methods for identifying at-risk individuals.
That's not to say researchers haven't looked into the issue; they've polled users suffering from antidepressant withdrawal symptoms. One study found that over half classified their symptoms as severe, and another discovered nearly half of users felt addicted to their prescription medication.
Can You Ever Ween Off?
All hope is not lost. While it can probably feel like the medical profession is unable to help problem, patients can – and do – recover. Many have turned to "microtapering." This involves slowly reducing the amount of medication over a long period of time, in order to slowly lessen and eventually eliminate any withdrawal symptoms.
For those who want a faster fix, it might be tough. Patients should always consult with their doctor before stopping medication. If a cold-turkey approach is approved, the patient may simply need supervision and support to work through the symptoms until withdrawal has ceased. If a dependence has developed, they will need further recovery support to find complete freedom from the medication.


text:
Meet our Team: Harriet Lowe
by Mel Abler | Nov 30, 2020 | Team TopRow, TopRow
If you've ever rowed with us in London, you've probably met (or at least emailed) Harriet. She joined our team in 2018 when our London Putney location first opened. It started as a summer coaching job after she graduated from university and before a winter working as a chalet host in France, but she enjoyed coaching so much that after the winter she came back to work with us. Harriet now handles most of our communications in London in addition to coaching.
Harriet tried a lot of sports growing up and "knew [she] lacked hand-eye coordination, so sports requiring throwing, catching, hitting, or kicking things" weren't a great fit. When she was 13, she saw a banner for an introductory rowing week and decided to give it a try. She loved it and "just kept coming back," rowing through both high school and university. Harriet also got into coaching while at university, spending her second year as a coach for the novice team to stay close to the sport while taking a break from rowing full-time. She now rows with London Rowing Club, and has continued training throughout the lockdowns to stay competitive.
According to Harriet "rowing is a great way to get outdoors, and it's relatively unique as a water sport because you can do it in the center of London." While there are plenty of competitive rowing programs in London, Harriet is excited to expand recreational rowing opportunities and make the sport more widely accessible. "Just enjoying your time on the water is a perfectly good reason to row."
Meet our Team: Lily Innes Irons
by Will Golding | Nov 1, 2021 | Team TopRow
My first introduction to rowing was during high school as a sports elective. Shortly after my introduction to rowing I joined my local club that had just reopened after 90 or so years of being closed. We didn't have any flash equipment, but we did have a hand full of...
Meet our Team: Kathryn Spinnler-Jenkins
by Will Golding | Oct 1, 2021 | Team TopRow
In high school rowing seemed daunting and inaccessible. Only ever picked as a goalie in netball for my height, I had decided that team sports, and sport in general, wasn't for me by age 13 or 14. When the opportunity came around to try for the rowing squad, I went...
Meet our Team: Xanthe Hadfield
by Will Golding | Aug 1, 2021 | Team TopRow
Sport has always played an important part of my life, but It wasn't love at first sight when I initially tried my hand at rowing at school. I was predominantly a competitive ballroom dancer, more concerned with getting blisters on my feet rather than my hands! After...
Meet the TopRow rowers: Cynthia Masters
Meet our Team: Thais Umbelino
Dock stories (1)
Rowing for everyone (2)

redpajama_set_name: RedPajamaCommonCrawl


text:
Rodrigo Pessoa
Rodrigo Pessoa ( born November 29, 1972 in Neuilly -sur- Seine) is a Brazilian show jumper and Olympic champion.
In February 2012 he was in the world ranking of FEI ranked 45th
In the 2004 Olympics he was on Baloubet du Rouet Olympic champion in show jumping. He benefited from the disqualification of the Irishman Cian O'Connor, whose horse Waterford Cristal was doped. 1996 and 2000, he had already won the bronze medal with the Brazilian team. At the World Equestrian Games in 1998 he won the individual gold medal. In 2006, he was unable to start because his horse Baloubet had just injured before. He participated as a coach of the Brazilian team.
In the years 1998, 1999 and 2000, he won in a row with Baloubet du Rouet the World Cup Finals Show Jumping. With Lianos Z he won the 1998 individual competition at the World Equestrian Games in Rome.
He also won in 2007 with Rufus as a member of the Brazilian team, the team gold medal and individual silver medal at the Pan American Games, the continental championships in the Americas. At the Pan American Games in 2011 he won team silver with Ashley.
As early as 1994 he won L.P. Special Envoy to the Grand Prize at the CHIO Aachen, Germany's most important equestrian events.
He was 2007-2011 President of the International Jumping Riders Club ( IJRC ), representing the interests of jumpers that are placed among the top 100 in the world rankings. He was succeeded by the Spaniard Cayetano Martínez de Irujo, who held this office before 2007.
Rodrigo Pessoa system is the " Haras de Ligny " in Fleurus near Brussels.
The show jumper Nelson Pessoa is his father.
In September 2009 he married the American show jumper Alexa Weeks, the two have a daughter born in 2011: Sophia. From his first marriage with the jumper Kery Potter, whom he married in June 2001, he has daughter Cecilia ( * 2004), who lives with her mother in San Diego.
In January 2011, Pessoa was honored as one of three athletes with the " Pierre de Coubertin World Fair Play Diploma " by the International Sports Journalists' Association AIPS. To be fair sporting behavior was rewarded, which he showed in the final four of the best show jumping with horse change at the World Equestrian Games 2010. Here he gave his rival Abdullah al - Sharbatly guidance on how this should Rebozzo ride ( Pessoa's horse), as well as the course. Al- Sharbatly, for this was the first singles final on the highest international standard, silver erritt in the individual competition; Pessoa missed the medals in fourth place.
At the opening ceremony of the Olympic Summer Games in 2012 he was given the honor of being flag bearer of the Brazilian team.
At the Olympic Games in 2008, he started with Rufus. He joined The individual competition here with fifth place. Even during the Olympics, however, it was announced that Pessoa's horse tested positive for nonivamide. Because at the time of the Olympic Equestrian Games 2008 nonivamide, was ( on the legs here as pain- causing substance ) classified the same way as capsaicin, depending on the application as unauthorized medication or doping, needed to be clarified to what facts it was in the case of Pessoa. The FEI Tribunal could prove no doping offense and sentenced Pessoa end of August 2008 on a four and a half month ban due to illegal medication. Pessoa himself founded the nonivamide - Fund on the one with the use of a nonivamidhaltigen ointment by the groom, on the other, so that Rufus and the horse Álvaro Affonso de Miranda Neto, Picolien Zeldenrust (which had to be operated during the Olympics ), a had to share ice machine and it was thereby come to contamination. At the same time he accused other riders ( no names ) to make regular manipulative measures to their horses. Rodrigo Pessoa appealed against the decision of the FEI Tribunal at the International Court of Sport (CAS ) against the judgment. A judgment of the CAS in this case is not known, the FEI evaluated Pessoa at the 2008 Olympic Games as disqualified.
Ciske van Overis (* 2002), brown Belgian Warmblood mare, Sire: Celano, Mother Father: Darco, ridden to May 2010 by Guy Williams, ridden by the end of 2011 from Edwina Alexander, from 2012 under Pessoa
Rufus (* 1998), brown KWPN gelding, Sire: Landaris, Mother Father: Renville
Baloubet du Rouet (* 1989) Selle Français stallion Fox, Father: Galoubet A, mother father: Starter
Lianos Z ( also Gandini Lianos, * 1987), brown Holsteiner gelding, Sire: Landlord, Mother Father: Landego
Special Envoy ( * 1980, † February 2010), Irish chestnut gelding, Sire: King of Diamonds
Summer Olympic Games 2007 Pan American Games 2011 Pan American Games Neuilly-sur-Seine Equestrian at the 2004 Summer Olympics Equestrian at the 1996 Summer Olympics Equestrian at the 2000 Summer Olympics 2010 FEI World Equestrian Games Abdullah Al-Sharbatly Brazil at the 2012 Summer Olympics Equestrian at the 2008 Summer Olympics Guy Williams (equestrian) Holsteiner horse Irish Sport Horse List of Olympic medalists in equestrian Jacques Cariou Alphonse Gemuseus Kurt Hasse William Steinkraus Graziano Mancinelli Jan Kowalczyk Pierre Durand, Jr. Ludger Beerbaum Ulrich Kirchhoff Jeroen Dubbeldam Eric Lamaze Steve Guerdat David Broome Hartwig Steenken Gerhard Wiltfang Gail Greenough Franke Sloothaak Dermott Lennon Jos Lansink


text:
Bosses can ban headscarves in some cases, EU court rules
A ban on religious symbols such as headscarves 'may be justified by the employer's need to present a neutral image towards customers or to prevent social disputes', the European Court of Justice says.
July 15, 2021 7:03 PM 2 minute read
In this March 15, 2013 file photo, a woman wearing a headscarf walks between other people on a street at the district Neukoelln in Berlin. The European Union's top court ruled July 15 that employers may forbid the wearing of visible symbols of religious or political belief, such as headscarves. Photo: AP
Employers can in principle ban staff from wearing headscarves in the workplace, an EU court ruled Thursday in two cases brought by Muslim women working in Germany.
A ban on religious symbols such as headscarves "may be justified by the employer's need to present a neutral image towards customers or to prevent social disputes", the European Court of Justice (ECJ) said in a statement.
The employer must also show it is not discriminating between different beliefs and religions in its policy, the court said.
The two women, a cashier in a chemist and a special needs carer, had taken their cases to German courts after being prohibited from wearing headscarves at work.
The German courts had then referred the cases to the ECJ for an interpretation of EU law.
The woman working at the chemist had been employed there since 2002 and had initially not worn a headscarf, but had wanted to begin wearing one after returning from parental leave in 2014.
However, the chemist instructed her to come to work "without conspicuous, large-sized signs of any political, philosophical or religious beliefs", the ECJ said.
The second woman was employed in 2016 as carer at a non-profit association and had initially worn a headscarf at work.
She too went on parental leave, during which time the association issued a policy prohibiting the wearing of visible signs of political, ideological or religious conviction in the workplace for employees with customer contact.
After returning from parental leave, she refused to remove the headscarf, which resulted in several warnings and eventually in her being dismissed.
National courts must examine in each individual case whether company rules are compatible with national laws on religious freedom and the need for a "policy of neutrality", the ECJ said.
There must be "a genuine need on the part of the employer" for such a policy, it said, and it must also not go against "national provisions on the protection of freedom of religion".
TagsReligionEUHeadscarves
UK MI5 chief says expulsion of Russian spies has delivered significant blow
EU set to pile more sanctions on Iran over crackdown on protesters
India can buy as much Russian oil as it wants, outside price cap, Yellen says


The Cartoonist of the magazine "Chayan".
Nasyrov was educated as a decorator and before coming to Moscow in 1976 he worked on performances in Kazan, Minsk, Chisinau. He also studied easel painting.
He was invited to Moscow by the magazine "Crocodile", where Nasyrov began to work in the genre of cartoons.
Also at one time was the main artist of the "Young Naturalist", who made him reconsider his attitude to animals.
Later he cooperated with the publishing house OLMA Media Group, which publishes the book series "Cats Warriors". Illustrated both books of cycles and special editions, as well as colored and colorful guidebooks.
Also he was an illustrator of the trilogy "War of Witches" by Maite Carranza, a series of Michael Ford's "Spartan" and other children's books.


text:
void smartsensor_init();

int ssIsActive();
void ssBlockUntilActive();
void registerSensorUpdateCallback(void(*func)(uint16_t i, SSState *sensor));

portTASK_FUNCTION_PROTO(smartSensorTX, pvParameters);
portTASK_FUNCTION_PROTO(smartSensorRX, pvParameters);

#endif  // INC_SMARTSENSOR_SMARTSENSOR_H_

redpajama_set_name: RedPajamaGithub


Removing adware from a computer is easy because there are plenty of Adware removal tools available for desktop operating systems. However, things become difficult when it comes to Android. So, here we have decided to share some of the best Adware removal tools for Android 2019.
If you keep great interest in the security world, then you might know about 'adware'. Usually, people think that malware and adware are the same, but it's not right. Adware is a kind of software which are designed to display ads to generate revenue.
Adware doesn't harm internet-connected devices, but it can ruin a user's web browsing experience. Adware usually enters your computer, smartphone or any other internet connected devices without your consent, and they bombard the system with ads.
Removing adware from a computer is easy because there are plenty of Adware removal tools available for desktop operating systems. However, things become difficult when it comes to Android. Let me tell you, there are not many adware removal tools available for Android, and removing them manually can be a challenging task.
So, here we have decided to share some of the best Adware removal tools for Android 2019. We have manually checked these apps, and they can remove hidden adware as well. So, let's explore the list of 5 best adware removal tools for Android smartphone.
Avast Antivirus is one of the leading security apps for Android available on the Google Play Store. Guess what? Avast Antivirus brings everything that you need to safeguard your Android smartphone. From call blocker to Photo vault, Avast Antivirus has it all. The most exciting thing about Avast Antivirus is its web shield feature which blocks malware-infected links, trojans, adware, and spyware.
Kaspersky Mobile Antivirus is another powerful Android security app on the list which can remove malware, adware, spyware from your device. The best thing about Kaspersky Mobile Antivirus is its background check feature that scans on-demand and in real-time for viruses, ransomware, adware, trojans. Not just that, but Kaspersky Mobile Antivirus also brings Find my phone, Anti-theft, App lock, anti-phishing features as well.
360 Security is another leading Android security app on the list which is now used by millions of users. Guess what? 360 Security brings a powerful virus removal tool that can scan and remove malware, vulnerabilities, adware, and trojans. Not just that, but 360 Security also offers users a few Android optimization tools like speed booster, junk cleaner, etc. So, 360 Security is another best Android adware removal tool that you can use right now.
Well, MalwareBytes needs no introduction because everyone knows about the leading security tool. Malwarebytes is also available for Android smartphone, and it can find and remove adware, malware, PUPs from your device. The great thing about Malwarebytes Security is that it searches all files and apps to remove malware, adware or PUPs. Not just that, but Malwarebytes Security can also detect ransomware before it can lock your device.
Norton Security and Antivirus is another best leading mobile security and virus protection app that's available on the Google Play Store. Norton Security and Antivirus help protect your Android phone against threats like malicious apps, fraud calls, theft, etc. The adware removal tool is not present in the free version of Norton security, but if you purchase the premium plan, then you can avail some extra features like Wifi security, real-time alerts, web protection, adware removal, ransomware protection, etc.


The Delhi Government led by Chief Minister Arvind Kejriwal recently announced their plan to implement odd-even scheme for traffic from January 2016. This huge step has been taken in wake of the frightening air pollution levels of the national capital. According to the recent data released by World Health Organization (WHO), New Delhi has the worst Air Quality among 1600 major cities of the world, including Karachi, and Beijing.
The Odd-Even scheme won't completely resolve the pollution problem, but at the least, will help in curbing its rise. Also there are other benefits, such as the traffic problem which has been a headache for Delhites will reduce, people will steer towards public transport such as Buses and Metro, increasing revenue, as 6000 new buses are scheduled to join the fleet of Delhi Transport Corporation (DTC) coming January. Next, if the formula succeeds in the national capital which has over 90 lakh registered vehicles (27 lakh cars) with 1500 new ones being added everyday, it will be much easier to implement it in other major cities such as Mumbai, Bangalore, etc. and even if it doesn't, we will have learnt the lessons so as to where things went wrong.
Odd number plates will be allowed on odd dates (1, 3, 5,..) and even number plates on even dates. Zero will be considered as even.
Will be applicable from 8am to 8pm from Monday to Saturday. Sundays are exempted.
Vehicles driven by women without any passengers also will be exempted.
This rule will be applicable to all ministries and bureaucrats in the National Capital Region (NCR).
The trial run will last from 1st January to 15th January of 2016 and after feedback from citizens, further course will be decided.
This system for Odd-Even vehicle restriction is new to India, but globally it has been successfully in practice for a long period, dating back to the era of Julius Caeser who declared the center of Rome off-limits between 6 a.m. and 4 p.m. to all vehicles except for carriages transporting priests, officials, visitors, and high ranking citizens.
In Beijing, temporary driving restrictions were imposed from 8 to 10 December 2015 as a measure to mitigate the red alert for hazardous smog. The smog alert system was put in place in 2013, and a red alert should go into effect if there is a prediction that the air quality index will stay over 200 for more than 72 hours. Cars with only even number plates were allowed on the first day of restriction. Electric cars were exempted as an incentive to promote the use of cleaner vehicles.
Partial driving restriction was imposed in Paris on March 17, 2014 to check the peak rise in air pollution caused by particulate matter. Complementary measures were implemented including reduced speed limits in the city, free public transportation, free residential parking, and free short-term use for subscribers of bike and car-sharing services.
There are some demerits too, but for now let's look at the brighter side of the picture and hope for such solutions from the Central Government as well, on a national level.


text:
Q: ZKTeco changing of ADMS Server IP Address remotely. Device IN01-A Im looking for a way to change the ADMS Server IP address remotely.
Currently i have a few devices onsite. Around 50+.
I am able to connect the device using public IP but
ATT software only allow me to change the Device IP.
My vendor helped me to change the ADMS Server IP using some standalone SDK for 1 device. But i need to change for more than 50 devices. They dont share with me the SDK. Cause they mentioned it quite old SDK. If anyone have some solution for me to try, do let me know. TIA!

redpajama_set_name: RedPajamaStackExchange


text:
Q: How to hide and show div if url is set to specific value using jquery/javascript? I'm sending a specific value through url and after that my page get refreshes.
The URL value is dynamic.Whenever URL sets I want to show div which is already hidden.
<button  id="show_id"  onclick="location.href='opdcasepaperreport.php?patient_nm='+document.getElementById('patient_id').value;" > View Report </button>

When user clicks on View Report , report div will be displayed.
I tried following 2 coding methods:
$( document ).ready(function()
{
    $("#show_id").click(function()
   {
       $('#main').toggle();

  });

});
and
$(document).ready(function ()
{
   if(window.location.href.indexOf("?patient_nm"))
   {
       //alert("your url contains ");
       //show code;
  }
});

in 1st case because of page refresh div get visible and un visible again.
Is there any solution for this like in php if(isset(---)){//do this;}

A: How about this:
$("#show_id").click(function(e)
{
  e.preventDefault();//this will prevent page refresh
  $('#main').toggle();
});

A: Changing location.href value will refresh the page anyway.
In order to hide/show div depending on url value you need to:

*

*get the value by searching in url params.

*show / hide div.

Get URL params.
You can use this script in order to get url params:
 var getQuery = function () {
  var url_params = {};
  var query = window.location.search.substring(1);
  if (query.length === 0) return false;
  var vars = query.split("&");
  for (var i=0;i<vars.length;i++) {
    var pair = vars[i].split("=");
    if (typeof url_params[pair[0]] === "undefined") {
      url_params[pair[0]] = pair[1];
    } else if (typeof url_params[pair[0]] === "string") {
      var arr = [ url_params[pair[0]], pair[1] ];
      url_params[pair[0]] = arr;
    } else {
      url_params[pair[0]].push(pair[1]);
    }
  }
 return url_params;
};

It will return an object (key, value).
Show / Hide div
If you using jQuery, you can simply is .toggle()
$("#your_div_name").toggle();

Or by using .show() / .hide()
So:
var query = getQuery();
if (query && query.some_param !== undefined) {
    $("#your_div_name").show()
} else {
    $("#your_div_name").hide()
}

But it's better not to use url params in order to change view.
Have fun.

A: Try following code:
 $( document ).ready(function()
    {
    function getParameterByName(name) {
        name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
        var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
        results = regex.exec(location.search);
        return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
    }

        var hasParam = getParameterByName('patient_nm');
        if(hasParam !== 'undefined') {
         $('#main').toggle();
        }
    });

As per your code, on button click the element will get toggled but after that the page gets refreshed immediately. On page refresh the element will be hidden again, so you are not able to view the effect.
As per my code above, when the page refreshes/loads, it will search for the parameter "patient_nm" that you are adding in the URL. If this parameter is not empty it will toggle the element. Since this process happens after page load, you will be able to see the results.
Hope this helps.


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