text:
\section{Introduction}
\label{intro}

Control of complex oscillatory networks is an important problem of nonlinear science,
with a number of practical applications. A particular challenge is to suppress collective
activity that emerges due to synchronization in a population of interacting
self-sustained units. This task is motivated by the ongoing research on efficient algorithms for the widely used medical technique called deep brain stimulation
(DBS)~\cite{Benabid_et_al-91,*Benabid_et_al-09,*Kuehn-Volkmann-17}.
DBS -- mostly used to treat Parkinson's disease -- entails high frequency open-loop
pulse stimulation of certain brain regions via implanted micro-electrodes.
The stimulation is typically supplied around the clock and can significantly relieve the limb tremor associated with the disease.
The exact mechanisms of DBS are still a matter of debate~\cite{Johnson2008,*Gradinaru-09,*Deniau_et_al-10},
and the working hypothesis, exploited by the nonlinear science groups
working in this field, assumes that the pathological brain activity emerges
due to an undesired synchronization of many interacting neurons.
Correspondingly, it is hypothesized that the goal of the DBS is to desynchronize
the large network of neurons, without suppressing the very oscillatory activity of
its nodes~\cite{Tass-99}.
Theoretical studies and computer simulations suggest that this goal can
be efficiently achieved by a feedback-based stimulation.
Proposed schemes exploit delayed or non-delayed, linear and nonlinear
control loops, with either continuous or pulsatile stimulation, and with adaptive tuning of the feedback
parameters~\cite{Rosenblum-Pikovsky-04,*Rosenblum-Pikovsky-04a,%
Popovych-Hauptmann-Tass-05,%
Tukhlina-Rosenblum-Pikovsky-Kurths-07,Montaseri_et_al-13,Lin_2013,*Zhou_2017,Popovych_et_al-17}.
An important advantage of these schemes is that they do not rely
on the phase approximation,
cf.~\cite{Tass-01,*Hauptmann-Tass-09,*Popovych-Tass-12,*Wilson-Moehlis-16,*Holt_et_al-16}.
Independently, the idea of feedback control is also being slowly developed  in the neuroscience
community and some simple feedback algorithms have already been tested experimentally~\cite{Rosin-11,*Little-13}.

Another line of recent development is related to the rapid growth of machine
learning (ML). The ML techniques are now extensively used for analysis and prediction of complex systems~\cite{Parlitz-18,*PhysRevLett.120.024102,*Zimmermann-Parlitz-18,%
*Quade-18,*Cestnik-Abel-19,*PhysRevE.99.042203,*Yeo-Melnyk-19}
and it is natural to try this framework for the purposes
of control as well. In this paper we propose to exploit an area of ML called reinforcement learning (RL) to suppress the collective mode in an oscillatory ensemble of globally coupled units.

Originally stemming from the optimal control problems and from the dynamical programming fields, reinforcement learning grew in popularity circa 1980~\cite{RL-Sutton1998}. RL algorithms differ from their predecessors in that they are capable of \emph{learning} the environment, effectively making it unnecessary to have a complete knowledge about the system in order to control it.
There are two major angles to RL that have been actively implemented in various adjacent disciplines: a Q-function based approach~\cite{RL-surveymain-kaelbling1996reinforcement} and a policy gradient approach~\cite{RL-PPO-schulman2017}. The Q-function methods rely on a piece-wise or a discrete reward and are, therefore, sub-optimal for the task of continuous synchrony suppression problem at hand. Instead, we will consider the policy-based approach, with the policy $\pi$ implying the optimal strategy or a set of rules to emit stimuli signals at different times to suppress self-sustained oscillations.

The policy gradient methods have many realizations based on stochastic gradient ascent algorithm~\cite{RL-Sutton1998}. In this work we will consider one of them, called Actor-Critic~\cite{RL-surveymain-kaelbling1996reinforcement}, and will conduct the Proximal Policy Optimization (PPO) for the purpose of synchrony suppression. Two artificial neural networks called Actor and Critic correspondingly are to be trained to suppress the collective mode, while relying on nothing but a reward for asynchrony. The role of the first network is to evaluate the policy, while the role of the other is to assess an advantage following each action by the Actor which sends the suppression stimuli to the environment. The overall Actor-Critic PPO RL module presented below can provide a robust data-driven control agnostic of the neuronal model and promises easy integration with current clinical DBS systems.

\section{The model}

In this work we consider a modern approach to RL based on proximal policy optimization with Actor and Critic algorithm~\cite{RL-stable-baselines} (see diagram of Fig.~\ref{fig:diagram}) to evaluate optimal policy $\pi$ for suppressing oscillations. There are five principal blocks that are involved in the control problem: (A)~Environment, (B)~Current State, (C)~Action block, (D)~Reward, (E)~PPO block containing two artificial neural networks (Actor and Critic). We will now describe each block and its function in detail.

\begin{figure}
\centering
\includegraphics[width=1.1\columnwidth]{RLfig1.pdf}
\caption{Principle diagram of Reinforcement Learning via PPO Actor-Critic algorithm.}
\label{fig:diagram}
\end{figure}

\subsection{The Environment.}
The first key component of the diagram in Fig.~\ref{fig:diagram} is the environment that the RL algorithm needs to interact with in order to suppress synchrony. The ``environment'' could be either a real patient or a numerical model that simulates pathological dynamics of neuronal ensembles. Herein, we focus on the latter, considering two models of collective neuronal activity. In both cases we deal with globally coupled networks. The first type of network units are the periodic Bonhoeffer-van der Pol oscillators that mimic regularly spiking cells. The second type are the chaotically bursting Hindmarsh--Rose neurons.

\subsubsection{Bonhoeffer--van der Pol oscillators}

Our first model is a population of $N$ globally coupled  Bonhoeffer--van der Pol oscillators:
\begin{equation}
\begin{cases}
\dot{x}_k &= x_k-x_k^3/3 - y_k +I_k +\varepsilon X + {\cal C}(t)\;,\\
\dot{y}_k &= 0.1 (x_k-0.8y_k+0.7)\;,\\
\end{cases}
\label{eq:bvdp}
\end{equation}
where $k=1,\ldots,N$, mean field $X=N^{-1}\sum_k x_k$, and ${\cal C}(t)$ is the action from the
controller, specified below in Section~\ref{sec:action}.
The units are not identical: the currents $I_k$ are taken from a Gaussian distribution with the mean $0.6$ and standard deviation $0.1$. The strength of the global coupling is determined by the parameter $\varepsilon$.
Collective dynamics of this system is illustrated by the phase portraits shown in Fig.~\ref{fig:BvdP1},
where we plot $Y=N^{-1}\sum_k y_k$ vs. $X$ for different values of the coupling strength $\varepsilon$,
as well as the limit cycle of an isolated Bonhoeffer-van der Pol oscillator.
\begin{figure}
\centering
\includegraphics[width=0.75\columnwidth]{RLfig2.pdf}
\caption{Phase portraits for the collective mode, for $N=1000$ and for different values of
the coupling strength $\varepsilon$ of the ensemble of Bonhoefer--van der Pol oscillators,
shown in mean-field coordinates $X=N^{-1}\sum_k x_k$, $Y=N^{-1}\sum_k y_k$.
Notice that for $\varepsilon=0.02$ the collective dynamics is chaotic.
For comparison, a phase portrait of one unperturbed oscillator is shown by a thick line (the case $N=1$, $\varepsilon=0$ is shown).
}
\label{fig:BvdP1}
\end{figure}

This model has two properties that make the control problem non-trivial.
First, for the sub-threshold coupling the  mean fields are $X_0\approx -0.27$, $Y_0\approx 0.55$,
i.e. the fixed point to be stabilized is not in the origin and is {\it a priori} unknown.
Next, this model exhibits chaotic collective dynamics for some values of $\varepsilon$ (see the broadened phase trajectory in Fig.~\ref{fig:BvdP1}).

\subsubsection{Bursting Hindmarsh--Rose neuronal model}
The second type of oscillators that we consider is an ensemble of Hindmarsh-Rose \cite{Hindmarsh-Rose-84} neurons in a bursting regime:
\begin{equation}\label{eq:HRn}
\begin{cases}
 {\dot x}_k &= 3x_k^2 - x_k^3 + y_k - z_k + I_k +\varepsilon X+{\cal C}(t)\;,  \\
 {\dot y}_k &= 1 - 5x_k^2 - y_k \;, \\
 {\dot z}_k &= 0.006[4 (x_k +1.56 ) - z_k]\;. \\

 \end{cases}
\end{equation}
The currents $I_k$ are taken from a Gaussian distribution with the mean
$3$ and the standard deviation $0.02$. For illustration, see Fig~\ref{fig:Bursting-TS} below.

\subsection{Current State Block}
\label{sec:state}
The Action and the Current State blocks in the algorithm shown in Fig.~\ref{fig:diagram}
are merely the input \emph{to} and the resulting response output \emph{from} the Environment.
We assume that both the input and the output are produced with a sampling rate $\delta$.
In a real experiment, $\delta$ is determined by the hardware, namely by the analog-to-digital and the digital-to-analog converters. In a numerical simulation, $\delta$ can be set by the solver of the ordinary differential equations,~\footnote{The complete cycle of the diagram in Fig.~\ref{fig:diagram} is a multiple of $\delta$.} effectively setting the smallest time-scale and a natural time unit in the results section below.

A particular number $M$ of the most recent points read from the Environment (to be used in the consequent averaging of the mean field $X$) should be chosen according to the given characteristic time-scale of the collective mode. A set of points corresponding to multiple period of oscillations for slow control algorithms, or a single period for the faster ones, could both be logical choices in the Current State block to provide proper feedback.

\subsection{Action Block}
\label{sec:action}

Generally, action can be of any complicated waveform. Here, we restrict our consideration to the case of pulse train action, with the constant
interval $\Delta$ between the pulses and an amplitude tuned for each pulse.
Taking into account that the pulse amplitude shall be limited by a
value $A_{max}$ specific to a given application, we write our action as
$${\cal C}(t) = \sum_n A_n{\cal P}(t_n)\,,$$
with $-A_{max}\leq A_n\leq A_{max}$ and $t_n=n\Delta$, $n=1,2,\ldots$. Here ${\cal P}(t_n)$
is a pulse of amplitude $A_n$ generated at the instant $t_n$.
Notice that $\Delta$ is a multiple of $\delta$.

We exploit pulses of two different forms.
The first one is a simple rectangular pulse (Fig.~\ref{fig:pulseform}a)
\begin{align*}
 {\cal P}(t_n) &=
  \begin{cases}
   1        & \text{if } t_n\le t < t_n+\tau_1\,,  \\
   0        & \text{otherwise}\,.
  \end{cases}
\end{align*}
Next, because possible neuroscience applications require the pulses to be bipolar and charge-balanced, we consider the pulses given by
\begin{align*}
 {\cal P}(t_n) &=
  \begin{cases}
   1        & \text{if } t_n\le t < t_n+\tau_1\,,  \\
   -\tau_1/\tau_2        &   \text{if } t_n+\tau_1\le t < t_n+\tau_1+\tau_2\,,\\
   0        & \text{otherwise}\,
  \end{cases}
\end{align*}
and illustrated in Fig.~\ref{fig:pulseform}b.~\footnote{
The currently available DBS devices deliver a pulsatile stimulation with a frequency of about 120 Hz. In particular, the pulse shape shown in Fig.~\ref{fig:pulseform}(b) is used.}

\begin{figure}
\centering
\includegraphics[width=0.75\columnwidth]{RLfig3.pdf}
\caption{Two types of pulses used for simulation.  The pulses appear at instants $t_n$ with
the interval $\Delta$. The pulse amplitude $A_n$ is determined by the neural network for each pulse; notice that it can be both positive or negative.
\textbf{(a)} Rectangular pulses have fixed width $\tau_1$. \textbf{(b)} Charged-balanced pulses
are determined by two fixed parameters $\tau_{1,2}$; the second amplitude parameter
$B_n$ is set to fulfil the condition $A_n\tau_1+B_n\tau_2=0$.
}
\label{fig:pulseform}
\end{figure}

Naturally, smaller values of  $A_{max}$ are commonly sought after in biological applications such
as the DBS in Parkinson's disease.
Being physically just a current, the action is deliberately applied to the first equation in
both~(\ref{eq:bvdp}) and (\ref{eq:HRn}), because it is that equation that describes the voltage across the neuron's membrane. The total ``energy'' per time supplied to the ensemble by $N_s$ pulses
\begin{equation}
A_\text{total}=(N_s\Delta)^{-1}\sum_{n=1}^{N_s} |A_n|\;,
\label{Atotal}
\end{equation}
is another measure that one aims to minimize in practice.

Similar to other control problems, the immediate feedback from the Environment is desired. For that, we use a Runge--Kutta-based solver to evaluate Eqns.~(\ref{eq:bvdp}) or (\ref{eq:HRn}) numerically, provided the input to the Environment is equal to the action ${\cal C}(t)$. The Current State block extracts the current value of the mean field, $X(t_n)$, from the solver, imitating a measurement.
To reflect a practical experimental realization, the PPO optimization will then rely only on the mean field array $X_{\text{state}}$ that contains a set of size $M$ of the most recent values of the mean field $X$, typically corresponding to a single period.
In other words, it is assumed that one can measure variable reflecting collective oscillation of the ensemble in practice.

\subsection{Reward Block}
In this work we are interested in intuitive reward functions that can be easily interpreted physically. Therefore, for a given action with the pulse amplitude $A_n$ and a given array of observations
$X_{\text{state}}$ at time $t_n$, we propose the following class of reward functions for synchrony suppression tasks:
\begin{equation}\label{eq:reward-general}
R\big[t_n\big] =-\sum_{j=0}^2 \alpha_j \big(X(t_n)-\langle X_{\text{state}}\rangle_n\big)^j - \beta|A_n|,
\end{equation}
where the sum term rewards convergence of the system to an average of the mean field over previous
$M$ values, $\langle X_{\text{state}}\rangle_n=M^{-1}\sum_{l=1}^M X(t_{n-l+1})$,
and the second term favors smaller values of the stimulus amplitude $A_n$.
Coefficients $\alpha_j$ and $\beta$ are the weight factors that, depending on an application, can introduce a bias towards a desired outcome (\textit{e.g.}, a more accurate convergence to a particular value of the mean field $X$ \emph{vs.} a smaller amplitude of the suppression pulse). Coefficients $\alpha_{1,2}$ define trajectory(rate) of desired suppression to the special point. The case of $\alpha_{1,2}$ = 0, $\alpha_0 > 0$ rewards for gradual decrease of stimuli to the baseline $A_n$=0.
Hence, the first term is a second order polynomial expanded around the target mean field value and the second term makes the action minimal while still suppressing the oscillations. We have the freedom to choose any reward function, but we chose the one that explicitly minimizes the stimuli amplitude.

Naturally, the Bonhoeffer-van der Pol ensemble of neurons~(\ref{eq:bvdp}) should be able to converge to the fixed point $\{X_0,Y_0\}$ if the system is rewarded simply as:
\begin{equation}\label{eq:reward-bvdp}
R_{\text{bvdp}}\big[t_n\big] = -\big(X(t_n)-\langle X_{\text{state}}\rangle_n\big)^2 - 2|A_n|,
\end{equation}
\noindent without the need to specify the values of $\{X_0,Y_0\}$ explicitly. We find empirically that this convergence is easily achievable in the regular model and the trade-off factor, responsible for minimization of the suppression pulse magnitude, could be increased to $\beta=2$ without any penalty.
On the other hand, the bursting oscillations of the Hindmarsh-Rose neurons impose an increased role on the second term in Eq.~\ref{eq:reward-general} (or a smaller parameter $\beta$ in the reward):
\begin{equation}\label{eq:reward-bursting}
R_{\text{burst}}\big[t_n\big]  = -2\big(X(t_n)-\langle X_{\text{state}}\rangle_n\big)^2 - 0.01 |A_n|.
\end{equation}

How to find the reward function automatically is the subject of active research in the machine learning community today~\cite{RL-rewardshaping}. For the scope of this manuscript, however, we restrict ourselves to the intuitive approaches of arriving at the coefficients $\alpha$ and $\beta$ in Eqns.~(\ref{eq:reward-bvdp}) and (\ref{eq:reward-bursting}). The problem of finding the reward automatically in the task of synchrony suppression and the corresponding strict optimization problem are yet to be solved.

\subsection{Proximal Policy Optimization Block}
We can now formally define our policy as a differentiable function (for brevity below we omit
index $n$ for the discrete time $t_n$):
\begin{equation}
\pi = \pi_\theta(X_{\text{state}},A)=\mathbb{P}_\theta\big\{X(t)=X_{\text{state}},\hspace{1pt} A(t)=A_n\big\},
\end{equation}
meaning that the policy $\pi$ is the probability of taking action $A_n$ when at state $X_{\text{state}}$ and the parameters approximating the action-state relationship are described by a vector $\theta$. Typically, $\theta$ represents weights of an artificial neural network that translates the values of an observed signal to an output action~\cite{RL-Sutton1998,RL-PPO-schulman2017}. The weights $\theta$ are initialized randomly and are then updated interatively as the network learns the proper translation.

In policy-based Reinforcement Learning we want to maximize our total Reward Function,
 \begin{equation}\mathcal{R}_\pi(\theta) =\mathbb{E}_{\pi}\Big[\sum^{T}_{t=0}\gamma^{t}\hspace{1pt}R\big[t\big]\Big],
 \label{eq:reward-Total}
 \end{equation}
which  shows  how  good  the  policy $\pi_{\theta}$ is  during  the  entire  synchrony  suppression  cycle of duration $T$ \footnote{$T$ is a macroscopic time-scale equal to the duration of stimuli application. For prospective wearable DBS systems, $T$ could be considered infinitely large.}. In Eq.~(\ref{eq:reward-Total}), $\mathbb{E}_{\pi}$ is a probabilistic expectation value, $\gamma$ is a discount factor that controls the trade-off between the long-term rewards and the immediate ones (typically equals to 0.99), and $R\big[t\big]$ is the reward at time $t$ described by any of the desired functions in Eqns.~(\ref{eq:reward-general})--(\ref{eq:reward-bursting}).

Following each measurement $X_{\text{state}}$ in the Current State block, the main idea of the PPO block is to be able to determine which action to take in order to maximize the reward given by Eq.~(\ref{eq:reward-Total}). The way to achieve this is to optimize the vector of parameters $\theta$.

The optimization follows Proximal Policy Optimization (PPO) algorithm that allows to choose optimal parameters to ascend in a direction of gradient in the policy, and towards maximal reward~\cite{RL-PolicyTheorem, RL-Sutton1998}.
Taking derivative of Eq.~(\ref{eq:reward-Total}) and using policy gradient theorem~\cite{RL-PolicyTheorem},
one can factor out a Score Function term $\bigtriangledown_\theta \log \pi_\theta$ and an Advantage Function term $\mathbb{A}^\pi$:
\begin{equation}
\bigtriangledown_\theta\mathcal{R}_\pi(\theta)=\mathbb{E}_{\pi \theta}\Big[\bigtriangledown_\theta \log \pi_\theta\big(X_{\text{state}},A_n\big)\hspace{2pt}\mathbb{A}^{\pi}\big(X_{\text{state}},A_n\big)\Big].
\label{eq:policygradient}
\end{equation}
It is these two factored terms in Eq.~(\ref{eq:policygradient}) that are evaluated by two artificial neural networks called ``Actor'' and ``Critic''.
The latter, Critic, is a neural network that estimates Advantage function $\mathbb{A}^{\pi}\big(X_{\text{state}},A_n\big)$ at the current time $t$. In simple words, the Advantage function is nothing but a deviation of the current reward from the maximal prior reward recorded during the experiment up until the time moment $t$; and the Critic network builds a fit approximating its value.
 This estimation is based on the reward function from Eq.~(\ref{eq:reward-general}), which will account both for the action optimization (minimize stimuli amplitude $A_n$) and for the state optimization (minimize $X(t)-X_{\text{state}}$) within the neural network.
 The Actor is the other neural network that predicts the probability of actions for all states and updates the policy distribution according to the suggestion by the Critic~\cite{RL-Sutton1998,RL-PPO-schulman2017,RL-stable-baselines}. Weights of both artificial networks $\theta$, the policy $\pi_\theta$, and the Advantage function $\mathbb{A}^\pi$ are updated after each complete cycle of the diagram in Fig.~\ref{fig:diagram}. We selected PPO algorithm because it has proven to be both fast and robust, providing a simple framework for optimizing all hyper-parameters in the neural networks and for implementing parallelization of computation~\cite{RL-Sutton1998,RL-PPO-schulman2017}.

\section{Results}

\subsection{Experimental configuration}

All calculations were carried out on a CPU of a Desktop computer (Intel(R) Core(TM) i7-6700K CPU @ 4GHz, quad-core 64-bit x86 architecture, 8GiB DIMM DDR4, GeForce GTX 670). Within the Environment block, we used the standard Runge--Kutta algorithm to solve the differential equations numerically. For proper resolution, we chose the integration step $\delta = 0.2$ in the Bonhoeffer-van der Pol neuronal model and $\delta = 0.1$ in the bursting Hindmarsh-Rose neuronal model. Specific parameters of suppression pulses $\tau_{1,2}$ and $\Delta$ (and the duration of suppression $T$) are provided in the Figure captions in units of $\delta$.

\begin{figure*}
\centering
\includegraphics[width=1.5\columnwidth]{RLfig4.pdf}
\caption{Suppression of synchrony in Bonhoeffer-van der Pol neurons (\ref{eq:bvdp}) for $N=1000$, $M$ = 160 using rectangular pulses ($\tau_1$ = 1, $\Delta$ = 5). \textbf{(a)} Coupling strength $\varepsilon = 0.03$. \textbf{(b)} Coupling strength $\varepsilon = 0.02$, chaotic regime for the collective mode. Action pulses used for suppression (bottom green curves) are plotted against the right axis in the units of the mean field.
Notice that in this and in the following figures, the time intervals $\tau_{1,2}$ and $\Delta$ are given in the units of integration step $\delta$.
}
\label{fig:TS-chaos}
\end{figure*}

We took a reliable library of stable releases of the PPO/A2C algorithm~\cite{RL-stable-baselines} and used an approach called PPO-Clip\cite{RL-PPO-schulman2017} that allows not to leave the vicinity of the original policy $\pi_\theta$ when an update is calculated. Both the Critic and the Actor were parameterized with dense neural networks in the Tensorflow~\cite{tensorflow2015-whitepaper} framework. Each network contained 2 hidden layers with 64 artificial neurons and with the \emph{tanh} function as the activation between the hidden layers. We fine-tuned the PPO-Clip to run with the following parameters:

\begin{center}
\begin{tabular}{ l l r l}
     $\bullet$ &\emph{gamma} = 0.99  & $\quad\bullet$ &\emph{n\_steps} = 128 \\
     $\bullet$ &\emph{ent\_coef} = 0.01 & $\quad\bullet$ &\emph{learning\_rate} = 0.00025 \\
     $\bullet$ &\emph{vf\_coef} = 0.5 &  $\quad\bullet$ &\emph{max\_grad\_norm}=0.5 \\
     $\bullet$ &\emph{lam} = 0.95 & $\quad\bullet$ &\emph{nminibatches} = 4 \\
     $\bullet$ &\emph{noptepochs} = 4  &  $\quad\bullet$ &\emph{cliprange} = 0.2 \\
\end{tabular}
\end{center}

During the stage of training the neural networks, the major optimization effort involved the step parameter \emph{n\_steps} and the entropy coefficient \emph{ent\_coef}. The former helps to find an optimal rate of updating the weights $\theta$ in the neural networks so that the solver has enough time to generate a substantially different output. The latter helps to reach the learning plateau faster by stochastically perturbing the current policy and effectively allowing it to reach its optima sooner.

The other parameters were kept at default values and are meant to provide a fast and robust convergence of the PPO algorithm. Despite quick convergence, the training was fixed to last 10 million steps to provide consistency in different experiments. The stimuli actions were restricted to take values in the range $-1\leq A_{max}\leq 1$. The values of errors reported below were calculated as a standard deviation in 16 repeated independent experiments.

\begin{figure*}
\centering
\includegraphics[width=1.55\columnwidth]{RLfig5.pdf}
\caption{Suppression of synchrony in Bonhoeffer-van der Pol neurons (\ref{eq:bvdp}) for $N=1000$, $M$ = 160 using charge-balanced pulses ($\tau_1$ = 1, $\tau_2 = 2$, $\Delta$ = 2), zoomed to the start of suppression. \textbf{(a)} Coupling strength $\varepsilon = 0.03$. \textbf{(b)} Coupling strength $\varepsilon = 0.02$, chaotic regime for the collective mode. Action pulses used for suppression (bottom green curves) are plotted against the right axis in the units of the mean field.
}
\label{fig:TS-CB}
\end{figure*}

\subsection{Synchrony suppression}
We first test the model on the ensemble of $N=1000$ self-sustained   Bonhoeffer-van der Pol neurons oscillating around a non-zero equilibrium point and globally coupled with $\varepsilon = 0.03$ (Fig.~\ref{fig:TS-chaos}(a)).
We selected $M=160$ last points for calculating the reward functions because it corresponds to a single period of $X(t)$, but we also studied the dependence on M experimentally (see Fig.~\ref{fig:sup-coef} below).
At $t=1000$ we initiate synchrony suppression by sending action pulses according to the pre-trained Actor-Critic duet of neural networks. We observe that the reward function described by Eq.~(\ref{eq:reward-bvdp}) rewards both the convergence to the natural equilibrium point, yielding a non-zero average {$X_0\approx -0.2676 \pm 0.0010$},
and the smaller values of the action amplitudes, yielding almost two orders of magnitude reduction in the action amplitude (right axis in Fig.~\ref{fig:TS-chaos}(a)). Immediately after $t=1000$ the action values are somewhat large; however, they become of the order of $\sim 0.02$ in about 300 time steps.
We also observe gradual relaxation of the ensemble to the original state as the stimulation is switched off at $t=4000$.

\begin{figure*}
\includegraphics[width=1.6\columnwidth]{RLfig6.pdf}
\caption{Suppression of synchrony in bursting Hindmarsh-Rose neurons (\ref{eq:HRn}) for $\varepsilon=0.2$, $N=5000$, $M$ = 160 with rectangular pulses ($\tau_1$ = 1, $\Delta$ = 5). \textbf{(a)} Mean field (top black curve) and action pulses used for suppression (bottom green curve, plotted against the right axis in the same units as the mean field). \textbf{(b)} Dynamics of two randomly chosen neurons illustrates that suppression of the collective mode is accompanied by desynchronization of individual units.}
\label{fig:Bursting-TS}
\end{figure*}
\begin{figure*}
\includegraphics[width=1.55\columnwidth]{RLfig7.pdf}
\caption{Zoomed regions from FIG.~\ref{fig:Bursting-TS}. \textbf{(a)} Initiation of suppression at $t = 500$. \textbf{(b)} Relaxation after the suppression is switched off at $t=2000$. Dotted curves are two different neurons. Thick curve is the mean field. Thin curves are the action pulses used for suppression, all of which are plotted against the right axis in the same units as the mean field.}
\label{fig:Bursting-TS-zoomed}
\end{figure*}

Reinforcement learning can also suppress synchronization in the Bonhoeffer-van der Pol ensemble
when the collective mode is chaotic ($\varepsilon = 0.02$). The results are shown in Fig.~\ref{fig:TS-chaos}(b). Although the oscillatory dynamics is now irregular, the Actor-Critic algorithm (rewarded with the same Eq.~(\ref{eq:reward-bvdp})) performs here similarly to the non-chaotic regimes, with {$X_0\approx -0.2596 \pm 0.0001$}, the same order of magnitude of the required amplitudes ($\sim 0.02$).
Naturally, relaxation to the original state of the ensemble in the chaotic regime, when the stimuli are switched off, occurs slower than in the regular regime with stronger coupling.

Charge-balanced pulses also prove functional to suppress synchrony both in the regular (Fig.~\ref{fig:TS-CB}(a)) and in the chaotic (Fig.~\ref{fig:TS-CB}(b)) regimes. The ensemble reaches the special point {$X_0\approx -0.2673 \pm 0.0029$} in the former and {$X_0\approx -0.2615 \pm 0.0010$} in the latter case.

Next, we consider the case of Hindmarsh-Rose neurons (\ref{eq:HRn}) for $\varepsilon=0.2$ and $N=5000$. The results of synchrony suppression, given a reward function Eq.~(\ref{eq:reward-bursting}), are shown in Figs.~\ref{fig:Bursting-TS} and ~\ref{fig:Bursting-TS-zoomed}. The bursting nature of the oscillators is seen in Fig.~\ref{fig:Bursting-TS}(b)
and its zoomed version Fig.~\ref{fig:Bursting-TS-zoomed}.
After a series of action pulses is applied at $t=500$,
the ensemble undergoes through a transient regime of about 400 time units and eventually desynchronizes.
This becomes obvious when one observes two randomly chosen individual neurons from the ensemble (see Fig.~\ref{fig:Bursting-TS}(b) and Fig.~\ref{fig:Bursting-TS-zoomed}(a) for a zoomed region around $t=500$).

As the Actor-Critic networks continue to adapt to the current state, the synchrony of oscillations vanishes around $t=600$ and the mean field converges to the special point {$X_0=-0.8754 \pm 0.0156$}.
Ultimately, when the suppression stimuli are switched off at $t=2000$, the ensemble enters the transient regime again, with initial enhancement and consequent weakening of synchrony as the mean field $X(t)$ gradually relaxes back to the original pattern, see Fig.~\ref{fig:Bursting-TS-zoomed}(b). In addition to rectangular-shaped stimuli, we observe a similar order of magnitude suppression in the Hindmarsh-Rose ensemble with charge-balanced pulses ($\tau_1$ = 1, $\tau_2$ = 5, $\Delta$ = 8) yielding $X_0=-0.8756 \pm 0.0003$.

\subsection{Quantitative analysis}
\label{sec:discussion}

In order to get additional insight into the efficacy of the RL-based suppression, we studied its dependence on various parameters of the system and of the stimulation.
The major factor that determines the amplitude of the collective oscillation is the coupling strength $\varepsilon$, which we thoroughly varied. The result for the Bonhoeffer -- van der Pol ensemble, Eq.~(\ref{eq:bvdp}), is shown in Fig.~\ref{fig:sup-coef}.

For the unperturbed system, the dependence of the standard deviation of the collective mode, $\text{std}(X_{\text{uncontrolled}})$, on the coupling strength $\varepsilon$ follows a threshold-like curve, typical for the Kuramoto transition~\cite{Kuramoto-84}, see dots in Fig.~\ref{fig:sup-coef}(a), while the $\text{std}(X_{\text{controlled}})$ for the suppressed field is shown in the same plot by boxes.
The latter quantity was computed when the Actor-Critic setup reached the best possible level of synchrony suppression. As can be seen in Fig.~\ref{fig:TS-chaos},
this final steady stage of the control is achieved soon after the stimuli application is switched on, at about $t_\text{steady}=1200$, and is preserved until the control is switched off at
$t_\text{off}=4000$. (The corresponding values for the Hindmarsh-Rose model are $t_\text{steady}\approx 700$ and $t_\text{off}=2000$, see Fig.~\ref{fig:Bursting-TS-zoomed}).

In the suppressed steady state the mean field continues to jitter due to the final size fluctuations.
The amplitude of the stimuli also fluctuates but the pulse sequence now has a uniform variance and a diminished range of amplitudes required to keep the control active.
The mean field fluctuations are known to depend on the ensemble size as~\cite{Pikovsky-Ruffo-99} $1/\sqrt{N}$.
Figure~\ref{fig:sup-coef}(a) suggests that the suppressed collective mode approximately reaches the finite size limit
~\footnote{The level of the finite-size fluctuations can be estimated as $\text{std}(X)$ for the sub-threshold values of the coupling $\varepsilon$.}.
We speculate that the additional source of fluctuations -- originating from the probabilistic uncertainty inherent to the Artificial Neural Networks that approximate the Score and the Advantage functions -- effectively trains the control algorithm to operate with noisy inputs, thus making it not only very efficient but also suitable for the experimental approbation in the future.

The extent of suppression of the mean field prior to the stimuli application, $X_{\text{uncontrolled}}$, given the mean-field values after, $X_{\text{controlled}}$, can be quantified by the following suppression coefficient
$$S=\text{std}\big[X_{\text{uncontrolled}}\big]\Big/\text{std}\big[X_{\text{controlled}}\big]\,.$$
Because the fluctuations of the suppressed field practically do not depend on $\varepsilon$, but the amplitude of the collective
mode of the unperturbed filed grows with $\varepsilon$, see Fig.~\ref{fig:sup-coef}(a), the suppression coefficient is maximal for strongly synchronized systems and achieves $S = 65.815 \pm 2.472$ for the Bonhoeffer--van der Pol ensemble. In the Hindmarsh-Rose model, the system is suppressed to $S=20.509 \pm 0.710$  by rectangular pulses ($\tau_1=1, \Delta = 5$) and to $S=24.821 \pm 0.900$ by charge-balanced pulses ($\tau_1$ = 1, $\tau_2$ = 5, $\Delta$ = 8).

\begin{figure}
\includegraphics[width=1\columnwidth]{RLfig8.pdf}
\caption{Quantitative analysis of suppression in Bonhoeffer-van der Pol ensemble via RL. \textbf{(a)} Standard deviation (std) of the mean field $X$ \emph{vs} coupling strength $\varepsilon$. Dots show dependence before suppression and boxes show std values after transient relaxation, when a steady suppressed state is achieved by virtue of \textit{rectangular} pulses. \textbf{(b)} Suppression coefficient as a function of length of observation $M$. \textbf{(c)} Suppression coefficient as a function of distance  $\Delta$ between stimuli of rectangular shape.
\textbf{(d)} Suppression coefficient as a function of pulse width $\tau_2$ in case of \textit{charge-balanced} pulses.
Error bars are standard deviations calculated on 16 experiments.
Bubble sizes are proportional to the total supplied energy $A_\text{total}$ (see Eq.~(\ref{Atotal}) for definition).
}
\label{fig:sup-coef}
\end{figure}

Figure~\ref{fig:sup-coef}bdemonstrates effect of the parameter $M$ which is the number of the stored recent values of the mean field. We see that suppression coefficient $S$ is not too sensitive with respect to variation
of $M$ around the value corresponding to the period of the field to be controlled. Notably, the spread of error bars on this dependence reduces around the single period value  $M$ = 160, suggesting a stable local minimum for optimizing the other parameters.

We have also studied the effect of pulse intervals $\Delta$ and $\tau_2$ on the suppression efficiency (Fig.~\ref{fig:sup-coef}c,d). The rationale behind this test is to look for the optimal frequency of action pulses in order to minimize the energy of the perturbation but to still suppress the synchrony.
 The resulting fall-off in the suppression efficiency in Figs.~\ref{fig:sup-coef}(c) and (d) can be deemed as a classic example of trade-off either when a limited stimuli energy $A_\text{total}$ must be used or when an incomplete suppression is desired.

\section{Discussion}
We demonstrated a successful adaptation of Reinforcement Learning to the synchrony suppression task in a globally coupled oscillatory network. Having considered limit-cycle  Bonhoeffer-van der Pol oscillators and bursting Hindmarsh-Rose neurons as the test models, the method proved functional both for regular and for chaotic collective oscillations, without having the knowledge about the ensemble model.
The suppression coefficient is of the same order of magnitude as the known feedback-based techniques~\cite{Popovych_et_al-17}, with the major differences occurring near the finite size fluctuations limit.
We foresee further enhancement of the performance with the development of the proposed RL-approach, along the following lines.

One option is to perform suppression via RL with architectures entailing deep artificial neural networks~\cite{RL-Deep-arulkumaran2017, Yeo-Melnyk-19} (instead of the two-layer ones considered herein). These approaches are known to be efficient when the networks of interacting neurons become especially large, as well as when a signal of interest is emitted at the same level as noise. As such, the deep control methods could be further enhanced by the signal-noise coupling techniques~\cite{dylov2011nonlinear, *dylov2011instability}, where the signal could be enhanced at expense of the noise thanks to the nonlinear nature of the environment~\cite{dylov2010natphotSR}.

Another option for improvement of the reported results entails introduction of a \emph{secondary} Actor-Critic model~\cite{RL-Multiagent-busoniu2006multi}.
In our preliminary experiment, we have trained such auxiliary model during the transient patterns such as those occurring immediately after $t=t_\text{on}$ in the suppressed regime.
We observe that when this secondary model overtakes the control, it further reduces the amplitude of the mean field $X$ and desynchronizes the ensemble beyond the performance of a single model (preliminary results show suppression improvement by 12\% compared to the single model).
This works because the response of the globally coupled ensembles is, generally speaking, nonlinear with respect to the stimuli amplitude.
Indeed, this response is determined by the corresponding phase response curve that does not depend on the stimuli amplitude only in the limit of an infinitely small action.

Long-term, one could envision a library of such Artificial Neural Networks pre-trained at different amplitude levels and at different values of pulse parameters ($A_{max}$, $\tau_{1,2}$, and $\Delta$) -- all to be embedded into the software controlling a DBS device. This promises a personalized approach to the patients with different signalling patterns and at different progression stages of the disease, regardless of its aetiology. The online learning could then utilize such a library and actively update the pre-trained models using the feedback signal measured by the DBS device.

We emphasise that the cause-effect relationship between the synchrony and the pathology is still an unproved hypothesis in neurobiology and computational neuroscience.
Control approaches that do not rely on this hypothesis are therefore naturally of interest, with the agnostic algorithms such as the RL method presented here being the most promising solution~\footnote{Notice that feedback-based techniques reported in [\cite{Popovych_et_al-17}] also do not use any information about the model of the system but explicitly assume that pathological activity emerges due to synchrony.
}.  Machine learning methods could be proposed for optimization of the stimulation parameters regardless of the aetiology of the disease. The way to demonstrate this before proceeding to the clinical experimentation is to go beyond our simplistic model
and to consider complex brain models such as the virtual brain~\cite{TheVirtualBrain},
also with account of synaptic plasticity in order to study long-lasting effects of desynchronization \cite{Tass-Majtanik-06}, or a live animal brain model~\cite{ParkinsonAnimalModel}.

Important advantage of the RL-based suppression method is that it is data-driven and universal. It could be readily implemented in an experimental setting, if one takes the measuring/stimulating equipment characteristics and limitations into account.
For example, currently available DBS devices are not capable of adjusting pulse amplitude sufficiently fast for the feedback-based technique, presented in Refs.~\cite{Popovych_et_al-17},~\footnote{Notice that the previously developed feedback-based suppression techniques were analyzed theoretically only for the unrealistic continuous-time stimulation and their modification to the pulsatile stimulation was an \emph{ad hoc}, relying on the assumption of a smooth continuous envelope.}. The suppression workflow proposed in diagram of Fig.~\ref{fig:diagram}, however, is universal and can be exploited for a predefined stimulation pattern. We find Reinforced Learning to be an ideal candidate for the clinical approbation as a ``smart'' control algorithm to be embedded into the deep brain stimulation devices.

The code used for simulations is available upon request from the authors.

\begin{acknowledgments}
DD acknowledges the support of IoT Center of Excellence of the National Technology Initiative of Russia.
\end{acknowledgments}

redpajama_set_name: RedPajamaArXiv


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text:
SAG-AFTRA Strike Against BBH Ends After Sides Reach Agreement
Saturday, Jul. 20, 2019
In this Jan. 21, 2018, file photo, SAG-AFTRA president Gabrielle Carteris speaks at the 24th annual Screen Actors Guild Awards at the Shrine Auditorium & Expo Hall in Los Angeles. (Photo by Vince Bucci/Invision/AP, File)
A 10-month strike by SAG-AFTRA against BBH in the U.S. is coming to an end after the advertising agency agreed to sign the union's new Commercials Contracts. BBH will produce all its commercials under these contracts, providing union wages and pension and health contributions to performers. As such, SAG-AFTRA members will be able to accept work on the ad shop's productions.
The dispute between the two parties came to the fore on Sept. 5, 2018 when BBH publicly announced it would withdraw as a signatory to the SAG-AFTRA contracts in place at that time, contending that they were outdated and not responsive to the realities of a dramatically changing marketplace. SAG-AFTRA, which had filed an unfair labor practice charge with the National Labor Relations Board (NLRB), called a strike against the agency later that month. Then in May 2019, an administrative law judge ruled against BBH and instructed the ad agency to both recognize SAG-AFTRA as the representative of commercial performers and to negotiate with the union.
"Our goal from the start was to produce high-level, cutting-edge creative work for our clients on a level playing field in a fast-evolving industry. We lost the battle, will respect the ruling and move on. We thank our clients for their unrelenting support throughout this process," read a statement from Brett Edgar, managing director of BBH NY. When asked by SHOOT for further comment, a BBH spokesperson declined to offer anything beyond what the agency and union released.
SAG-AFTRA president Gabrielle Carteris said in a released statement, "We're pleased that BBH has returned to their longtime status as a SAG-AFTRA signatory. Since the inception of our relationship nearly 20 years ago, we have partnered effectively to provide the best talent in the world to BBH clients while ensuring fair compensation and safe working conditions for SAG-AFTRA members. It has been and will continue to be an extraordinarily productive relationship delivering value to the entire industry. Now, with our new 2019 Commercials Contracts we are thrilled that BBH can take full advantage of the transformative compensation models in this groundbreaking agreement to better compete in the constantly evolving advertising industry."
David White, national executive director of SAG-AFTRA, stated, "We are pleased to welcome BBH back to the SAG-AFTRA family. The tremendous solidarity of our entire membership is to thank for helping bring BBH back to the table. Our members look forward to once again collaborating with BBH and providing their professional talent to create innovative, memorable and award-winning commercials."
BBH is an agency in the Publicis Groupe family which also includes such notable SAG-AFTRA signatory shops as Saatchi & Saatchi and Leo Burnett.
SAG-AFTRA
Andrew Wonder
TG Herrington
The Kacey Musgraves Christmas Show
In Finé
Krista Liney

redpajama_set_name: RedPajamaCommonCrawl


Dale Discusses, "Resetting the U.S.-Russian Relationship? Risks and Opportunities"
Follow Us on Social Media to Be a Part of Nunn School Adventures!
The Surveillance, Privacy, and Data across Borders: Transatlantic Perspectives Conference is on April 18th. For more details, please click here.
Check out our Facebook page to stay current with upcoming events!
Nunn School alumni and friends gathered for a networking reception on Monday, March 20th at the City Club in Washington, D.C. The cocktail reception commemorating the 20th anniversary of the Nunn School was generously hosted by David Cooper (INTA 1996) and Maranda Smith. The fourth annual Alumni and Friends Reception featured keynote speaker Gen. Philip Breedlove, USAF (Ret.), a Georgia Tech alumnus and distinguished professor at the Nunn School.
Congratulations to Dr. Jenna Jordan on her selection as one of the winners of the Center for Teaching and Learning/BP Junior Faculty Teaching Excellence Award.
Thank you for creating a great learning environment for your students!
Congratulations to Gen. Philip Breedlove, USAF (Ret.) and Adm. James "Sandy" Winnefeld, USN (Ret.) on their recognition by the Georgia House of Representatives through the State House Resolution adopted March 14, 2017 for their service to our nation and for returning to their alma mater, Georgia Tech as distinguished professors.
Senator Sam Nunn, our school's namesake, was recently interviewed by Atlanta's NPR station. In the two-part series, Senator Nunn spoke on North Korea, Trump, Nuclear Weapons and Russia.
To listen to part 1 on North Korea, click here.
To listen to part 2 on Trump, Nuclear Weapons, and Russia, click here.
The annual DC Career Visit was on Thursday, March 2nd and Friday, March 3rd, and fourteen students from the Nunn School, Mechanical Engineering, City and Regional Planning, and Public Policy participated. Students had a rewarding trip, click here for more information.
The Sam Nunn School of International Affairs at Georgia Tech Sam Nunn Security Fellows meeting with the Vice President's National Security Adviser & Senior Policy Advisors on March 21st in the original Secretary of the War offices (in the EEOB).
On March 21st, Gen. Philip Breedlove, USAF (Ret.) testified before the Senate Armed Services Committee on U.S. Policy and Strategy in Europe. Watch his testimony beginning at 30:45.
On March 13th, Center for International Strategy, Technology, and Policy & Center for European and Transatlantic Studies sponsored, Dr. Catherine Dale, who discussed "Resetting the U.S.-Russian Relationship? Risks and Opportunities." In her talk, she stressed four points. To read these four points, please click here.
An article written about our namesake, Senator Sam Nunn was published in the Macon Telegraph. The article was written by fellow Perryan, Larry Walker and begins explaining where the nickname, "Little" derived from. He continues listing the numerous accomplishments of Senator Nunn that have made fellow Perryans proud. Just as Perryans are proud of the Senator, we too are honored to have him as namesake and distinguished professor of our school. Read the article here.
Kirk Bowman and Jon Wilcox (sponsor of Dr. Bowman's Chair) presented their film, Bad' & the Birdieman, at the 41st Atlanta Film Festival on Saturday March 25 to a full and enthusiastic audience. This film tells the story of innovation, leadership, community building, and sports and development in a favela in Rio de Janeiro.
Make sure to follow us on Facebook, Twitter, Pinterest, Tumblr, and Instagram to see the incredible work being done at the Nunn School!


DELAND -- Midway through the third quarter, the DeLand boys basketball team looked beaten.
Their shots weren't falling, and Spruce Creek was doing pretty much what it pleased on offense.
And then, the blitz came from the home team in white and green, and it overwhelmed the Hawks.
Suddenly, DeLand's 3-pointers were raining down like snow in the Northeast, Spruce Creek's top scorer lost his poise and was ejected and DeLand ended up cruising home with a 65-54 victory.
The win avenged DeLand's early-season loss to Spruce Creek and tied the teams with one loss apiece atop the District 2-6A standings.
"We were pointing to this game for a while, and this is a huge, huge win for us," said DeLand junior Ryan Hagy, who scored 15 points to go with 10 rebounds. "We just turned it up and started playing harder in the second half because we needed this win."
Dennis Diaz added 14 points and 10 rebounds, and Logan Murray chipped in 13 points.
With Spruce Creek (13-5) leading 32-24 late in the third quarter, DeLand (10-5) suddenly started playing with more energy and roared back with an 8-0 run to tie the score at 32 with 2:01 left in the quarter.
Then Diaz, who is headed to Stetson next year, hit a driving layup and was fouled by Creek's Corey Favors. Favors got a technical for saying something either to the official or to Diaz, then got a second technical and was ejected for bumping DeLand's Jeramie Neal while walking back toward midcourt.
"Corey's an emotional player, and you want a guy to play with emotion," Spruce Creek coach Joe Giddens said. "We lost our composure and we got deflated after he left."
DeLand extended its burst to a 17-0 run, capped by Hagy's 3-pointer in the final seconds of the third quarter, to grab a 41-32 lead.
The Bulldogs went up by 12 in the fourth thanks to their balanced scoring attack, and the Hawks never recovered.
In the first meeting between the teams this season Nov. 30, Spruce Creek jumped out to a double-digit first-half lead and was never threatened en route to a 67-57 win.
On Friday night, Spruce Creek jumped out to an early lead again, thanks to six first-half points from Favors.
Diaz picked up two early fouls in the first quarter for DeLand, relegating him to the bench for most of the half.
Mike Castello led Spruce Creek with 14 points.
SPRUCE CREEK (13-5) Castello 14, Barnes 12,Marfiak 10, Favors 8, Nelson 4, Meseroll 3, Agers 3. Totals: 20 9-14 54.
DELAND (10-5) Hagy 15, Diaz 14, Murray 13,Neal 11, Mestre 4, Hamilton 3, Galliher 5. Totals: 23 16-28 65.
3-point goals-- Spruce Creek 5 (Marfiak 2, Barnes, Agers, Meseroll); DeLand 5 (Murray 3, Hagy 2). Total Fouls--SC 21; DeL 17. Fouled out--None. Technical fouls--Favors 2.


Some of you may be aware that Mary Forstbauer, longtime RCFM vendor selling organic produce, beef, and other farm products and BCAFM president, has undergone heart surgery. Above all, RCFM tries very hard to be a community and we thank everyone who has expressed their concern for Mary. She's doing well and is at home. She sent this note we wanted to pass along to everyone who has asked about her and sent along their good thoughts.
Thank you for all your prayers and healing thoughts this past month. Thank you for your calls, cards and flowers. I am now the proud owner of a new aortic heart valve. On Aug 19, 2010 My open heart surgery was successful. After one week in hospital I was released to the care of my family. At home I am taking it easy and walking as instructed by my medical team. (My walks the first week were 5 minutes but they felt like I had run a marathon). I am slowly increasing my walking time and activities. The healing time is about 12 weeks. Once my heart healing has been completed I will undergo knee replacement on my right knee hopefully late fall or early winter. I am healing and look forward to returning to the markets next spring as the new Super Organic Earth Mother. A special thank you to my good friend Mhora who has stepped forward and looked after the markets that she an I have been attending this summer.
We are so pleased that things have gone well, Mary! Can't wait to see you soon.


text:
Stonehenge Trilithon Blown Over - The Times
The Times letter pages and opinion pieces were buzzing in 1901 following the storm damage of Dec 31 1900. The arguments for and against restoration are familiar, the right of free access is argued as fences are erected and the public charged a shilling to enter; the right of the private owner to do as he will with his property and the case for state ownership are made.
A subscription to the Archive is good value.
Stonehenge Handed Over
The Times, October 28, 1918
STONEHENGE HANDED OVER.
SIR A MOND ON FURTHER EXCAVATIONS.
On Salisbury P1an on Saturday afternoon Stone
henge was formally banded over to the nation by
Mr. Chubb, of Bemerton Lodge, Salisbury, and
accepted on behalf of the Government by Sir Alfred
Moud. In receiving the deed of gift, the First
Commissioner of Works said the step that Mr. Chubb
had so generously and patriotically taken had aroused
the deepest feeling of gratitude throughout the
country. The Prime Minister had expressed his
personal appreciation of Mr. Chubb's action. Not
only had Stonehenge itself now become the property
of the nation, but 30 acres of surrounding ground
accompanied the gift. He hoped that steps would
be taken to improve the surroundings of Stonehenge.
There had been much criticism of the fencing, but
it would be impossible to leave the monument
entirely unguarded. It was proposed, by means of
a sunken fence to afford the necessary protection
without offending the eye. He, also hoped that it
would be possible to extend the important excava
tions which had already been made on the site.
There were in the local museum some of the stone
implements with which the huge stones of the temple
of Stonehenge were dressed and trimmed. It, was
hoped that, under supervision, discoveries would be
made on the site which would throw further light on
the history of the monument. "This ceremony takes
place," be concluded. "at a time which is perhaps
a turning point In the history of our country. After
four years of anxiety, toil and peril we see at last
the sun of victory shining over the horizon. It is
a good augury. Our ancestors hero worshipped the
sun when it rose. We to-day can turn our eyes
towards the sun of victory won so gallantly by the
men who have gone out and fought and died for us."
MPP - Researching Stonehenge: Theories Past and Present
Researching Stonehenge: Theories Past and Present
Mike Parker Pearson
Over the years archaeologists connected with the Institute of Archaeology and UCL have made substantial contributions to the study of Stonehenge, the most enigmatic of all the prehistoric stone circles in Britain. Two of the early researchers were Petrie and Childe. More recently, colleagues in UCL's Anthropology department – Barbara Bender and Chris Tilley – have also studied and written about the monument in its landscape. Mike Parker Pearson, who joined the Institute in 2012, has been leading a 10-year-long research programme on Stonehenge and, in this paper, he outlines the history and current state of research.
View the full article: Full text PDF
Posted by Tim Daw at Friday, October 25, 2013 1 comment:
Why was Stonehenge built where it was?
The excitement st Stonehenge has moved a mile or so east as the dig at Blick Mead continues to astonish with its finds. A major Mesolithic site, but was it even earlier? This ITV film suggests so:
http://www.itv.com/news/west/update/2013-10-23/why-was-stonehenge-built-where-it-was/
Posted by Tim Daw at Thursday, October 24, 2013 10 comments:
The Stonehenge Hidden Landscapes Project pdf
Download of pdf and online access:
http://www.academia.edu/1751987/The_Stonehenge_Hidden_Landscapes_Project
The Stonehenge Hidden Landscapes Project
by Vincent Gaffney
"Over the centuries many archaeologists have investigated the site of Stonehenge and we now know a great deal about the phasing and nature of the site. However, the area around the henge, while containing many symbolic and ritual elements, is curiously 'blank'. The Stonehenge Hidden Landscapes Project aims to place the site and its development through time within a landscape context using fast and accurate ground-based geophysical techniques. The project has developed a rapid strategy to map, visualize and interpret landscape-scale data and is applying the strategy to the area known as the Stonehenge 'envelope'. The data are interpreted within a data rich three-dimensional data cube that has provided new insights regarding the apparent blank areas surrounding Stonehenge. It is an aim of the project to discover more about Stonehenge by looking out from the site rather than looking at it."
Posted by Tim Daw at Sunday, October 20, 2013 No comments:
Series of Guides To Archaeological Features
INTRODUCTIONS TO HERITAGE ASSETS (ARCHAEOLOGY)
http://www.english-heritage.org.uk/caring/listing/criteria-for-protection/scheduling-selection-guides/IHAs/
"English Heritage's Introductions to Heritage Assets (IHAs) for archaeology are accessible, authoritative, well-illustrated summaries of what we know about specific classes of sites or monuments.
While there is no aspiration to have an entirely comprehensive series covering all types of sites from early prehistory to present, the 41 IHAs completed to date do include the majority of the main groups of heritage asset from early prehistory to the end of the Middle Ages."
Here's a few I have picked out as especially interesting to me, but they are all very good, why didn't I know about them before? (The subjects are in the URLS.)
http://www.english-heritage.org.uk/publications/iha-prehistoric-henges-circles/prehistorichengesandcircles.pdf
http://www.english-heritage.org.uk/publications/iha-prehistoric-avenues-alignments/prehistoricavenuesalignments.pdf
http://www.english-heritage.org.uk/publications/iha-hillforts/hillforts.pdf
http://www.english-heritage.org.uk/publications/iha-banjo-enclosures/banjoenclosures.pdf
http://www.english-heritage.org.uk/publications/iha-prehistoric-barrows-burial-mounds/prehistoricbarrowsandburialmounds.pdf
Early Photo of the Stonehenge Parchmarks
(click to embiggen)
An early postcard (1930?) shows Gowland's prop holes as pale parchmarks and also the stoneholes 17,18 and 19 as faint marks (17 is the clearest). They run in an arc from the upright stone on the left, stone 16, round in front of the group dressed in black towards the upright stone at the top middle of the picture. Stonehole 20 is mainly under the fallen stone with the black mark on it.
For details of their discovery this summer see here
Posted by Tim Daw at Wednesday, October 16, 2013 No comments:
Using A Crisp Packet To Date A Stonehenge Feature
To the west of Stonehenge there is a byway known as Byway 12 or The West Track. It originally went through the henge monument itself on the line of the present visitor path. After the Nation was given Stonehenge in 1918 it was moved just to the west of the henge and the local residents granted free access in return for not opposing the move.
Stonehenge with the West Track near to the henge.
Before the present visitors facilities and tunnel were opened in 1968 the track was moved again, much further to the west to its present position.
The moves can be seen in this series of maps dating from 1901, 1961 and 1972
But when was it moved?
Surprisingly I can't find out online, or in Cleal or any other book I have to hand. Sometime between 1961 and 1968....
But I have a crisp packet that surfaced this week from the buried surface of the track and it dates from 1965-66. That's how archaeology dates structures so I have narrowed the date down now to my satisfaction.
Dateable Artefact of the Stonehenge Builders Found on A344
As the careful works goes on of restoring the A344 to turf and realigning the visitor's path to Stonehenge I was fortunate enough to lay my hands on an artefact that was dug up by the tunnel. It nearly blew away in the wind but years of litter catching training at Stonehenge enabled me to pounce on it.
I think it dates from the late 1960s when the present visitor centre and tunnel was built and the West Track was moved. I will send it to EH for their archaeologists to identify and date it fully..
UPDATE: http://www.goldenwonder.com/history - 1965 Golden Wonder launched unique packaging to keep crisps fresher for longer – using the "Crackle Fresh" slogan
Wired Stonehenge
The path at Stonehenge is being resurfaced which involves changing the edging - it is all being done under close archaeological supervision.
A snippet of more reason history was uncovered today - the geophone cables which were installed in 1968 were uncovered.
The plan from Cleal et al below shows their route.
Click any to enlarge.
New science pinpoints source of Bluestones
Link to an interesting article:
http://www.earthheritage.org.uk/ehpdf/EH40_7-13final.pdf
Richard Bevins,
Keeper of Natural Sciences,
National Museum of Wales
Rob Ixer,
Institute of Archaeology,
REMODELLING STONEHENGE - 2013 BEN CULLEN PRIZE WINNER
THURSDAY 3RD OCTOBER 2013
Professor Timothy Darvill OBE, along with co-authors Peter Marshall, Mike Parker Pearson and Geoffrey Wainwright, have been awarded the 2013 Ben Cullen Prize by the leading international journal Antiquity for their article entitled 'Remodelling Stonehenge' which was published in the December 2012 issue.
You can read the full article here.
Further information on the Prize, and other Prize winners can be found here.
From http://www.pooleandpurbeckportal.co.uk/showcase/412/remodelling_stonehenge_2013_ben_cullen_prize/ - The Poole & the Poole & Purbeck Portal, a new online community created by the School of Applied Sciences at Bournemouth UniversityPurbeck Portal, a new online community created by the School of Applied Sciences at Bournemouth University
Posted by Tim Daw at Tuesday, October 08, 2013 No comments:
Stonehenge Landscape Poster
The Stonehenge landscape: restoring biodiversity and connectivity
Grace Twiston-Davies, Jonathan Mitchley, Simon Mortimer
11th INTECOL Congress 2013, Ecology: Into the next 100 years, 18 - 23 Aug 2013, B2.16
Background / Purpose:
Habitat restoration at the landscape scale has the potential to re-connect fragmented landscapes. The chalk grassland restoration project at the Stonehenge World Heritage Site, UK is a case study that provides an opportunity to investigate the landscape and species characteristics that lead to successful restoration.
Main conclusion:
Habitat restoration at the landscape scale is an effective, long term approach to enhance biodiversity and restore landscape connectivity. Quite rapid success is achievable for some habitats and species but additional management is needed for specialist species.
DOWNLOAD The Poster [1.15 MB] This poster is open access subject to the CC BY Creative Commons 3.0 License
Stonehenge World Heritage Site Management Plan Review 2013-14
http://www.stonehengeandaveburywhs.org/management-of-whs/stonehenge-whs-management-plan-review/
The current Stonehenge World Heritage Site Management Plan is under review and we want your help!
Stonehenge and Avebury World Heritage Site (WHS) was inscribed onto the World Heritage List in 1986, one of the first seven from the UK. The Stonehenge part of this WHS covers 26 square km centred on the Stonehenge monument stretching from the Packway to Lake in the Woodford Valley and from the A360 to the A345.
The WHS is managed by a partnership of public bodies, landowners and residents who meet regularly to discuss progress on the Management Plan which is the document which sets out the main issues for the WHS and actions to protect and enhance its "outstanding universal value". A WHS Coordinator oversees the implementation of the Management Plan and reports to the WHS Committee.
The last Management Plan was produced in 2009 and there was a great deal of high profile public consultation at that time as it coincided with a complete review of the location of the Stonehenge visitor centre following the decision of the government not to fund the proposed tunnel for the A303 at Stonehenge.
It has been decided by the steering committees of both parts of the WHS to produce a joint Management Plan for both Stonehenge and Avebury. Many of the issues are similar for both parts of the WHS and we are currently working on joining together more closely the management of Stonehenge and Avebury which have been managed separately until now. Avebury started work on their management plan last year and this year it is Stonehenge's turn. As it is only 4 years since the publication of the last management plan it is not expected that it will be radically different, more an update of the issues and a review of the action plan.
We would be very pleased to hear your point of view and to facilitate this there will be drop-in sessions when you can talk to the Stonehenge WHS Coordinator, Beth Thomas and discuss your issues and aspirations for the World Heritage Site and the community who live and work in and around it.
Sessions are being held at the end of October at: Durrington Library Wednesday 23 October 2 – 5pm, the Bowman Centre 24 October 12 – 3pm, Amesbury Library 24 October 4 – 7pm, Shrewton Recreation Hall 29 October 10am – 1pm and Salisbury Library 29 October 4 – 7pm. We can't promise to include all your suggestions into the new management plan but we would love to hear your thoughts! If you can't attend why not complete this questionnaire and email or post it back to us?
If you want to find out more please contact Beth Thomas, Stonehenge World Heritage Site Coordinator.
The Hidden Code in The Stonehenge Visitor Centre Roof
Detail of the new visitor centre at Stonehenge roof.
It has been suggested that the similarity of the holes punched in the roof in appearance to the holes of punched computer tape means that there is a meaning to them. That they can be deciphered to reveal a hidden message. I am assured that they are purely random and there is no meaning to them. Any decoding of them that creates a message is just another Stonehenge myth.
There is no hidden message in the Stonehenge Visitor Centre roof.
(And Paul is alive)
MPP - Researching Stonehenge: Theories Past and Pr...
Dateable Artefact of the Stonehenge Builders Found...
Stonehenge World Heritage Site Management Plan Rev...


text:
Moneyval: Internal corruption is Vatican's primary risk
News: Vatican finances
What happened: The Council of Europe's anti-money laundering watchdog has issued an in-depth review of efforts by the Holy See to combat financial crimes.
What's new: The long-awaited report from Moneyval recognized areas of progress, but highlighted the significant risk of abuse of office within the Vatican, and the lack of experience and resources among investigators and prosecutors in efforts to combat financial crime.
Why it matters: The report's recommendations appear linked directly to a slew of changes to Vatican financial law in recent months, and to the high-profile Vatican financial scandal.
EuroTower, Frankfurt, Germany. Credit: Michael Scheinost
The report from Moneyval, published Wednesday but originally expected to be released in April, presents the findings of a two-week onsite inspection of Vatican financial institutions last year, which wrapped up in October. The visit was the first time inspectors had visited the city state since 2012.
The report primarily focused on the Institute for Works of Religion (IOR), which is the sole Vatican commercial banking institution under Moneyval's oversight, and the efforts of the ASIF, the Holy See's financial intelligence unit, along with Vatican City prosecutors.
While generally praising Vatican institutions' assessment and efforts to combat money laundering and terrorist financing by non-Vatican residents and institutions, inspectors "disagreed" with the Holy See about the ongoing threat of internal financial misconduct by officials.
"[Vatican] authorities have advised that they consider the risk of abuse of office for personal or other benefits presented by insiders and related money laundering to be low," the report concluded. "However, the assessment team disagrees with this conclusion and is of the view that risks presented by insiders are important."
"Cases which have received wide coverage in the media have raised a red flag for potential abuse of the Holy See/Vatican City State system by mid-level and senior figures (insiders)," the report noted.
The Moneyval inspection covered the period up to October 2020, which includes the still ongoing investigation into the Secretariat of State's London property scandal, which has seen several senior officials dismissed or suspended, and at least one person arrested.
The investigation into the secretariat's investment of hundreds of millions of euros of borrowed money into a London building at 60 Sloane Avenue is being conducted by the Office of the Promoter of Justice for the Vatican City State and began in July, 2019.
The investigation was triggered by a suspicious activity report to the Vatican's financial intelligence unit, filed by the IOR, after senior officials at the secretariat, including Cardinal Pietro Parolin, attempted to pressure the IOR into approving a 150 million euro loan to help refinance the secretariat's investment.
Moneyval concluded that, while the system for internally reporting suspicious activity appeared to be functioning with "varied" results, "insufficient attention seems to be given to information provided in incoming mutual legal assistance requests" from foriegn jurisdictions.
The report was generally positive in its treatment of the IOR, which is the single financial institution under its review, and called the risk of money laundering "medium-low".
Because the IOR is in Vatican City, its accounts are not subject to taxation and other regulations imposed by other countries. This has made it a target for abuse by money launderers. But, a key finding of the report suggests that threat of internal corruption, not abuse by outside crime syndicates, presents the most likely risk of ongoing money laundering at the IOR.
While in 2012 the inspectors did not emphasize the risk of internal corruption ahead of external abuse of Vatican financial institutions, the 2021 report did just that. This change follows concerted efforts in the years 2014-20 to close suspicious accounts held by non-Vatican residents and institutions at the IOR and other Vatican institutions like APSA.
"The authorities originally concluded that the main risk of money laundering arose from tax evasion by non-residents," the report said. "It later became clear that tax evasion is no longer considered to be the main source of money laundering."
"The dominant typologies suggested by cases and suspicious activity reports include predicate offenses of fraud, misappropriation, giving and receiving bribes, and abuse of office" within the Vatican itself, Moneyval found.
According to the report, Vatican officials told Moneyval inspectors "that they consider the risk of abuse of office for personal or other benefits presented by insiders and related money laundering to be low."
"However," the report said, "the assessment team disagrees with this conclusion and is of the view that risks presented by insiders are important."
"The assessment team has concluded that the general risk assessment process cannot be fully complete without a comprehensive assessment and articulation of the risks presented by insiders and the risks in relation to public authorities."
The report, dated April 2021, was written prior to several recent changes to Vatican financial law issued by Pope Francis, which appear to address these specific concerns.
In the week the Moneyval report was originally slated for release, Francis issued two new laws for the Vatican.
The first, issued on April 29, aimed to combat corruption by senior officials in the curia and in the city state, and that bars investments in companies or businesses "contrary to the social doctrine of the Church." It also criminalized the Vatican's bustarella culture of officials exchanging cash gifts.
The second major change to Vatican law, issued by the pope on April 30, allowed for the criminal prosecution of cardinals and bishops in the ordinary court of Vatican City State with papal approval.
This change appears to have been a direct answer to a key action item recommended by the Moneyval report, which called for the Vatican to "establish a comprehensive procedure for petitioning the Holy Father when requesting consent to pursue a criminal prosecution against cardinals and bishops."
While recognizing that responses to Vatican requests for international cooperation in pursuing cases were sometimes late and delayed, Moneyval highlighted the Holy See's "under-resourcing on both prosecutorial and law enforcement sides, and insufficient specialisation of financial investigators until comparatively recently."
While the Vatican has made efforts in recent months to hire new specialist judges and prosecutors, the report recommends that the Vatican "recruit more prosecutors with practical experience of prosecuting financial crime in other jurisdictions, and ensure all new prosecutors work exclusively for the Holy See/Vatican City State."
On the key metric of securing legal convictions in instances of money laundering, Moneyval called the Vatican's results since the last inspection in 2012 "modest," and said that while crimes were investigated once detected, sentences imposed after convictions were arguably not enough to deter future offenses.
"Money laundering activities investigated and prosecuted so far are, in general, consistent with risks identified by the jurisdiction," the report said, but warned that "actual sanctions imposed in money laundering cases where there have been convictions are below the statutory thresholds for the money laundering offense and appear rather minimal."
"Arguably," the report said, "they are not proportionate and dissuasive."


India vs Australia First Test Match Live Score, Commentary, Stream, TV Channels Information. Australia vs India first test match will be played at "Adelaide Oval, Adelaide". Match Starts from 12:00 AM GMT time and on date December 06, 2018 to Monday 10, 2018.
Australia Team Squads : Pat Cummins, Aaron Finch, Tim Paen, Peter Handscomb, Marcus Harris, Josh Hazlewood, Travis Head, Usman Khawaja, Nathan Lyon, Mitchell Marsh, Shaun Marsh, Peter Siddle, Mitchell Starc, Chris Terman.
How to watch India vs Australia First Test Match Live Score, Commentary, Stream, TV Channels Information ?
Australian cricket lovers can watch india v australia first test match on fox sports television network. www.foxsports.com provides the live cricket match in australia country. India vs Australia 1st test match on hotstar application. Hotstar apps can download from google play store. www.hotstar.com provides the live score and live ball by ball commentary of india vs australia 1st test match. Hotstar is the digital platform of star sports network television.
We will now discuss about India vs Australia broadcast channel in india 2018. There are list of India vs Australia broadcast channel list. Fox Sports and Seven Network television channel provides india vs australia broadcast of first test match.


text:
Q: How do you use the Delegate Protocol Pattern with SpriteKit? So I have one UIViewController and two SKScenes. The UIViewController present the two scenes by rotating the device; landscape load SKScene 1 and portrait load SKScene 2 lie this:
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        print("TRIGGERED")

        if UIDevice.current.orientation.isLandscape {
            print("Landscape")
            presentView(name: "GameScene")
        } else {
            print("Portrait")
            presentView(name: "GameScene2")
        }
        super.viewWillTransition(to: size, with: coordinator)

    }

    func presentView(name: String) {
        if let view = self.view as! SKView? {
              if let scene = SKScene(fileNamed: name) {
                  scene.scaleMode = .aspectFill
                  view.presentScene(scene)
              }
              view.ignoresSiblingOrder = true
              view.showsFPS = true
              view.showsNodeCount = true
          }
    }

This works fine. My dilema, however, is that I want to implement a delegate-protocol pattern between the two SKScenes GameScene and GameScene2. The problem is that the UIViewController (self) of SKScene 1 should be passed as the delegate to the SKScene 2. So if the user for instance click something in landscape mode (GameScene), som data String is passed over to GameScene2 when orientation is changed to portrait.
So in SkScene 1:
protocol MyProtocol {
    func myProtocolFunc(someString: String)
}

class GameScene: SKScene{

    var myDelegate: MyProtocol!

and in the UIViewController how do I set the delegate? scene.myDelegate doesn't work. GameScene().myDelegate = GameScene2().self works but since view.presentScene(scene) is used to present the scene that's not relevant. How do I access and set the delegate? How do I set up the delegate-protocol pattern so that I get the desired result?

A: Using Swift 5:
protocol MyProtocol: AnyObject {
    func myProtocolFunc(someString: String)
}

class GameScene: SKScene {
    weak var myDelegate: MyProtocol?

    init(fileNamed: String) {
        super.init(fileNamed: fileNamed)
    }
}

Then you have to create the scene object in your presentView method as a GameScene, not a SKScene (as you did). So instead of:
if let scene = SKScene(fileNamed: name) // wrong

you have to:
if let scene = GameScene(fileNamed: name) // correct

and then you can easily set the delegate with scene.myDelegate

redpajama_set_name: RedPajamaStackExchange


Packaged food and drink consumption in Europe is projected to grow by 3% per annum to 953 billion packages by 2020 (Smithers Pira). This growth provides both opportunities for food packaging professionals; with more competition than ever before for your products to stand out and engage consumers in-store and in the home but also more chances to communicate with your customers never has it been more crucial for innovation within food packaging.
At Packaging Innovations, you will find the right packaging suppliers who are constantly discovering new and exciting ways of facing the challenges of today, by working with you to reinforce your brand and ensure the quality of your product.
This year in the Food Forum, Gousto will be sharing their approach to reducing packaging and plastic, Percol will reveal how they became the first coffee brand to launch plastic-free packaging, and the dried fruit company Wallaroo is debating if the future of snack packaging should be compostable.
These food brands have already registered to attend...have you?


text:
Градина је археолошки локалитет који се налази у месту Станишор, општина Гњилане. На овом вишеслојном налазишту, на остацима који припадају старијем гвозденом добу, подигнута је гробница током рановизантијског периода. Гробница се датује у 6. век. Озидана је опеком и има крстасти свод.

Основ за упис у регистар
Решење Покрајинског завода за заштиту споменика културе у Приштини, бр. 180 од 27.3.1980. г. Закон о заштити споменика културе (Сл. лист САПК бр. 19/77).

Види још
 Списак археолошких налазишта у Србији

Литература

Спољашње везе

Археолошка налазишта у Србији
Општина Гњилане
Косово и Метохија
Непокретна културна добра

redpajama_set_name: RedPajamaWikipedia


NASHVILLE, Tenn. — Puckett's Gro. & Restaurant's "Funds 4 Food" campaign will end this week and has nearly reached its ambitious goal to provide 40,000 meals to local families struggling with hunger through Second Harvest Food Bank of Middle Tennessee.
The month-long campaign, which started April 1, has given diners the opportunity to add an extra $1 to their total bill to help fund meals for those in need. In addition, Puckett's 5th & Church has pledged to match each donation up to $5,000.
According to Second Harvest Food Bank, one in seven people — including one in five children — struggle with hunger in Middle Tennessee. Nearly 15 percent of local residents are unable to regularly access the food they need to be healthy.


text:
U.S. Army to Purchase 15,000 More Beretta 92FS Pistols
10/10/11 10:37 PM | by Max Slowik
Despite their recent announcement that they're done with the M9/M92FS pistol, and that they would be (and presumably still are) shopping around for a new sidearm, the Army has gone ahead and bought an additional 15,778 Berettas to restock their worn supply and supply friendly forces around the world.
The Army, not quick to decide what to roll out next, is just going to get more of the same. Mind you, the military has suggested requirements for an Army sidearm and the M92FS, for all its strengths, meets none of them.
The Army wants a pistol that's got interchangeable sights, closed slide, dustcover/frame-mounted rail, and, well, it's big. The Army isn't just big dudes, and something with interchangeable backstraps would be nice for a change.
They've also reported problems with the slide safety being an issue with rap-tap-target-style clearing of jams and mis-feeds. And ultimately, they're considering a handgun in .40 S&W or .45 ACP.
Still, it's clear that they need something, even if they're going to be giving them away. (Snark: is there a branch of the government that isn't giving guns away, and why haven't we received any yet?)
"'This order reminds us that Beretta 9mm pistols remain a central part of the American arsenal,' commented Jeff Reh, Vice-General Manager for Beretta U.S.A. 'These particular pistols are being supplied as part of the U.S. Army Foreign Military Sales program in aid to Afghan troops and to assist other U.S. allies around the world.'
"The Beretta 92FS 9mm pistol and its U.S. military equivalent, designated the M9, have been manufactured in the U.S. since 1987 by an American work force that now stands at around 300 employees. To date, over 600,000 Beretta 9mm pistols have been delivered to the U.S. military by the Beretta U.S.A. facility in Accokeek, Maryland."
They are, at least, putting U.S. workers on the job.


I love to share my books, recommend my favourites, and talk about what I like about them. I rarely don't like something about a book. It is someone's heart and soul so you have to find something to like! Click here for my list to date.
In honour of my son's birthday, I thought it would be fitting to post a book that he loved. Now I could have posted Harry Potter (the books that got him reading), but I thought would be better to post about a book that he made us read over and over and over again. Barnyard Dance by Sandra Boynton with its "Stomp your feet! Clap your hands! Everybody ready for a Barnyard Dance!" This is actually the original cover of the book and I can, to this day, repeat all the words by memory.
What was the book that sticks out for you with your kids? Or your childhood?
These books made me laugh out loud so many times. There are four books in the series (The Mammy; The Chisellers; The Granny; The Scrapper). The main character, Agnes Brown, has been portrayed in movies, tv shows and theatre productions. Set in Ireland, it follows Agnes Brown after her husband dies and leaves her with seven children. Short books for a quick and entertaining read.
Buy this giggle worthy book at your local bookstore.
The Gargoyle completely surprised me when I read it. Reading the cover, I thought there was no way I was going to like this book. Love it when I'm surprised. The story begins with the narrator involved in a horrific accident, leaving him disfigured. While waiting to leave the hospital so he can commit suicide, he meets a sculptress of gargoyles, who insists they were once lovers in medieval Germany. I know bizarre! And it just gets better. This quote from the book is one of my favourites "You are mine, I am yours; you may be sure of this. You've been locked inside my heart, the key has been thrown away; within it, you must always stay". Don't be scared, read it.
Buy this unique but wonderful book at your local bookstore.
When I am asked for book recommendations, I almost always recommend The Red Tent by Anita Diamant. It is the story of Dinah, who is the daugther of Jacob in the Book of Genesis. But you do not have to be a religious person to enjoy this book. I recommend it because of the story, the beautiful writing, the tales of motherhood and the sisterhood amongst the female characters in the book. All women should read this book.
Buy this amazing book at your local bookstore!
I have read this book a number of times and have recommended it to so many people over the years. It was first published in 1989 by Australian author Bryce Courtenay, telling the story of a young English Boy growing up in South Africa during the 1930s and 1940s. Peekay goes through many adversities, meeting a number of unique characters along the way. I have read this book a couple of times as it's messages throughout have always made me think. I find it's one of those books where I want to meet the characters. They made a movie version of the book, but it's not near as good as the book. Great read for teenagers too.
Buy this wonderful book at your local bookstore!


text:
Food Active > Childhood Obesity > "Coca-Cola Christmas truck is not welcome in Cumbria"
"Coca-Cola Christmas truck is not welcome in Cumbria"
15 Dec, 2017 by Beth Bradshaw
A local newspaper the Time and Star published an article last week titled "Coca-Cola Christmas truck told to stay away from Cumbria – and not come back"
The article comes as the Director of Public Health at Cumbria County Council Colin Cox and Council Lead Stewart Young both signed the open-letter to Coca-Cola from Sugar Smart, co-ordinated by Food Active in November. Whilst the truck was not planned to visit Cumbria this year, both signed the letter on the grounds that we should not be welcoming this marketing stunt into our towns and cities given the current obesity crisis – in Cumbria, over 1/4 of reception aged children are overweight or obese, 4.5% greater than the national average [1].
In the article, Colin Cox is quoted:
"Excessive sugar consumption is one of the major public health challenges of our time, leading to high rates of obesity particularly in childhood.
"The Coca-Cola truck may seem like a bit of festive fun but it is actually a high profile marketing campaign for a sugar syrup that is contributing to our very worrying rates of childhood obesity"
Stewart Young also said:
"The way it is marketed, children find it very attractive. It is almost like Santa coming. That's how it is promoted. There's a clear attempt to conflate the two. It's clever marketing,"
"Yet we are facing this obesity epidemic and the real consequences won't be seen until much later on, when children grow up. We are heading for serious public health problems."
Cumbria were one of the 6 local authorities in the North West to sign the open letter to Coca-Cola, urging them to rethink their Christmas marketing campaign and market more responsibly to children. Following this letter signed nationally by 29 Directors of Public Health, Council Leads and Food Groups, there was significant media coverage across the country and was later followed by Public Health England releasing guidance to local authorities on Christmas promotions, such as the Coca-Cola truck. Duncan Selbie, Chief Executive of Public Health England, was quoted in the Guardian (29.11.2017):
"Local authorities celebrating sugary drinks in this way need to reflect on whether it's in the best interests of the health of local children and families."
Alison Tedstone, Director of Obesity at Public Health England also wrote in a blog:
"The link between childhood obesity and deprivation is well established and it's important to note the (Coca-Cola) truck will be visiting some of our poorest areas"
Over the last couple of years, Food Active has raised questions about welcoming the Coca-Cola truck to our towns and cities, given the amount of money and hard work spent by public health to reduce children's sugar consumption. We published an editorial in the BMJ in early 2017 and gained over 100 signatures from health professionals, Directors of Public Health and parents opposing the truck's arrival in 2016.
It is great to see the conversation continuing and we hope in times to come more can be done to prevent the truck from . Well done to Cumbria and all other North West local authorities who signed the open letter with Food Active and Sugar Smart.
To read the full article from the Time and Star, follow this link.
[1] Public Health England. (2017). NCMP Local Authority Profile Data [online]. Available at: https://fingertips.phe.org.uk/profile/national-child-measurement-programme/data#page/0 [Accessed: 15th December 2017].
Beth Bradshaw
More articles by Beth Bradshaw
Events 4 years ago
Food Active Event Summary: Promoting Healthy Weight – National Policy to Local Action
Food Active, Champs and NW ADPH recently facilitated and hosted the Regional Healthy Weight Event: 'Promoting Healthy Weight – National
Latest News 8 months ago
Guest blog: Why aren't all children walking to school? Current challenges and potential solutions.
Dr Rob Noonan is a Lecturer at the University of Liverpool. Twitter: @RobJNoonan Email: R.noonan@liverpool.ac.uk It's timely for us
Share your experiences of drink options in children's meals when eating out!
Food Active are seeking views from parents, grandparents, carers/guardians, aunties and uncles alike, to share their experiences of drink options


text:
Q: does length of name or id value matters in performance in javascript? is lenghth of name/id value affect the performance?
for example;
performance wise which option is better ?
<input type='text' name='candidatefirstname' id='candidatefirstnameID' />

or
 <input type='text' name='fname' id='fnameId' />

A: Modern computers are so fast that the difference is not significant.

A: Since Javascript is a runtime interpreted language (or formally known as Scripting Language), the variable name length does not make a difference.
However, you might want to consider that on a larger scale of many identifiers with long names, the size of the HTML that the client will  have to download is increased and that will increase loading time for the user.

A: As the previous poster states, it's minimal. Might matter slightly if the script is large and especially if it's not cached and used frequently, in that case use a minimizer.


Amazing collection of Food HD Wallpaper? Home Screen and Backgrounds?
Amazing collection of Food HD Wallpaper? Lock Screen Wallpapers, Home Screen and Backgrounds ? to set the picture as wallpaper on your phone in good quality.
* Automatically change Food HD Wallpaper.


One of the signature spells for Holy Priests is the ability to use the spell Guardian Spirit. GS is fantastic, however sometimes can require communication to prevent double duty from either the tank's cooldown or another priest's cooldown. Up until about a month or so ago, I had been using a macro that whispered my target should I have cast GS on them, letting them no that they have Guardian Spirit and I was watching over them… The downside to this is, should I start mashing my GS keybind and my target is out of range or line of sight, they still received the whisper spam.
Enter the mod: Guardian Spirited.
GuardianSpirited is a mod that provides whisper notification to your target, raid, raidwarning, battleground, yell, say, and/or custom channel that you have used GS on them. GuardianSpirited not only provides them notification when GS has been applied, but it also provides notification when the GS has faded. Making this even more useful it also provides notification should the GS have actually prevented a killing blow, thus not lasting the usual 10 seconds.
Above you'll see sample GS text informing the target (via whisper) and a custom channel that GS had been applied and then subsequently faded. I HIGHLY suggest Holy Priests being sure they are running this and broadcasting in ICecrown for the Dreamwalker encounter. Timing and chaining GS for the 40% healing buff will become a pivotal role in learning the encounter.
But Derevka, I dont play Holy! I'm Disc! Why would I want this addon?
This very simple, yet effective mod has proven to be very handy in raids. While some raid members do tend to tease me for spamming the healer channel, deep down they know its valuable information.
As always, please feel free to post comments here with questions, or email the address at the sidebar of this post!


text:
Welcome to Thick Skin's documentation!
======================================

Contents:

.. toctree::
   :maxdepth: 3

   readme
   installation
   usage
   reference/index
   contributing
   authors
   changelog

Indices and tables
==================

* :ref:`genindex`
* :ref:`modindex`
* :ref:`search`

redpajama_set_name: RedPajamaGithub