Competitive minimax universal decoding for several ensembles of random codes

Universally achievable error exponents pertaining to certain families of channels (most notably, discrete memoryless channels (DMC's)), and various ensembles of random codes, are studied by combining the competitive minimax approach, proposed by Feder and Merhav, with Chernoff bound and Gallager's techniques for the analysis of error exponents. In particular, we derive a single--letter expression for the largest, universally achievable fraction $\xi$ of the optimum error exponent pertaining to the optimum ML decoding. Moreover, a simpler single--letter expression for a lower bound to $\xi$ is presented. To demonstrate the tightness of this lower bound, we use it to show that $\xi=1$, for the binary symmetric channel (BSC), when the random coding distribution is uniform over: (i) all codes (of a given rate), and (ii) all linear codes, in agreement with well--known results. We also show that $\xi=1$ for the uniform ensemble of systematic linear codes, and for that of time--varying convolutional codes in the bit-error--rate sense. For the latter case, we also show how the corresponding universal decoder can be efficiently implemented using a slightly modified version of the Viterbi algorithm which em employs two trellises.Comment: 41 pages; submitted to IEEE Transactions on Information Theor

The skills needed to be re-elected are different to those needed to be an effective legislator

Osnat Akirav summarises a journal article which examines the ability of legislators to get re-elected by their fulfilling their three roles: legislation, oversight and representation. She also re-examines the claim that most legislators are motivated by a desire to be re-elected, and that this desire determines the utility of their legislative activity toward this end by advertising, credit claiming and position taking. She further argues that different skills are required to be selected as a party’s choice and be re-elected, and to enact legislation. Thus, she distinguishes between two types of legislators—those who are electable and those who are successful in the legislature

The Role of Cannabinoids in Modulating Emotional and Non-Emotional Memory Processes in the Hippocampus

Cannabinoid agonists generally have a disruptive effect on memory, learning, and operant behavior that is considered to be hippocampus-dependent. Nevertheless, under certain conditions, cannabinoid receptor activation may facilitate neuronal learning processes. For example, CB1 receptors are essential for the extinction of conditioned fear associations, indicating an important role for this receptor in neuronal emotional learning and memory. This review examines the diverse effects of cannabinoids on hippocampal memory and plasticity. It shows how the effects of cannabinoid receptor activation may vary depending on the route of administration, the nature of the task (aversive or not), and whether it involves emotional memory formation (e.g., conditioned fear and extinction learning) or non-emotional memory formation (e.g., spatial learning). It also examines the memory stage under investigation (acquisition, consolidation, retrieval, extinction), and the brain areas involved. Differences between the effects of exogenous and endogenous agonists are also discussed. The apparently biphasic effects of cannabinoids on anxiety is noted as this implies that the effects of cannabinoid receptor agonists on hippocampal learning and memory may be attributable to a general modulation of anxiety or stress levels and not to memory per se. The review concludes that cannabinoids have diverse effects on hippocampal memory and plasticity that cannot be categorized simply into an impairing or an enhancing effect. A better understanding of the involvement of cannabinoids in memory processes will help determine whether the benefits of the clinical use of cannabinoids outweigh the risks of possible memory impairments

Does changing electoral rules affect legislators’ productivity?

There have been numerous reforms to the electoral rules and candidate selection processes for the Israel parliament (Knesset) in recent years, making it an interesting case study for testing the hypothesis that such changes affect legislators’ productivity. Using a model that acknowledges there are many facets to legislators’ roles Osnat Akirav demonstrates that legislators’ productivity is affected changes to these rules – but that this does not in turn make it more likely that they will be re-elected

Legislators use of One-Minute Speeches

This study examines how legislators use one-minute speeches OMS in a venue never before considered the Israeli parliament the Knesset The study considers two research questions First do legislators use OMSs to set their agenda and make policy If so in what way Second what are the characteristics of the legislators who make extensive use of OMSs We consider these questions in light of the global economic crisis of 2007-2010 The findings show that legislators made very limited use of OMSs as tool for making policy about the economic crisis We found the same trend in the finance committee meetings and motions for the agenda Furthermore while opposition MKs junior MKs and Arab MKs used OMSs more extensively than other MKs they still rarely used them as a policy-making too

Cannabinoid CB1 and Dopamine D1 Receptors Partnership in the Modulation of Emotional Neural Processing

A commentary on The dopamine and cannabinoid interaction in the modulation of emotions and cognition: assessing the role of cannabinoid CB1 receptor in neurons expressing dopamine D1 receptor

The Role of the Medial Prefrontal Cortex-Amygdala Circuit in Stress Effects on the Extinction of Fear

Stress exposure, depending on its intensity and duration, affects cognition and learning in an adaptive or maladaptive manner. Studies addressing the effects of stress on cognitive processes have mainly focused on conditioned fear, since it is suggested that fear-motivated learning lies at the root of affective and anxiety disorders. Inhibition of fear-motivated response can be accomplished by experimental extinction of the fearful response to the fear-inducing stimulus. Converging evidence indicates that extinction of fear memory requires plasticity in both the medial prefrontal cortex and the amygdala. These brain areas are also deeply involved in mediating the effects of exposure to stress on memory. Moreover, extensive evidence indicates that gamma-aminobutyric acid (GABA) transmission plays a primary role in the modulation of behavioral sequelae resulting from a stressful experience, and may also partially mediate inhibitory learning during extinction. In this review, we present evidence that exposure to a stressful experience may impair fear extinction and the possible involvement of the GABA system. Impairment of fear extinction learning is particularly important as it may predispose some individuals to the development of posttraumatic stress disorder. We further discuss a possible dysfunction in the medial prefrontal cortex-amygdala circuit following a stressful experience that may explain the impaired extinction caused by exposure to a stressor

Populism and legislative backsliding

IntroductionThis study presents a comprehensive set of measurements for assessing legislative backsliding and authoritarian populist rhetoric.MethodsI demonstrate the use of these measures by comparing the discussions involved in passing three Basic Laws in Israel. One was enacted in the 20th Knesset term, whereas the other two were passed during the current 25th Knesset that began in 2022.Results and discussionThe findings indicate more legislative backsliding in the 25th Knesset than in the 20th Knesset. The quality of the deliberative process was poorer, there was less respect for informal institutions, and there was more use of formal procedures to change previous behavioral norms during the 25th Knesset. In addition, the use of authoritarian populist rhetoric increased during this Knesset term and was used to justify and legitimize legislative backsliding

Legislators' Patterns of Cooperation

This study attempts to identify the patterns of cooperation between legislators. We argue that if legislators decide to cooperate, they prefer to do so first with their colleagues who share similar affiliations and then across affiliations. In order to examine this hypothesis, we devised a unique cooperation scale and tested it using a sample of the private member bills that were initiated in the 18th Knesset (Israel’s parliament) between 2009 and 2013. We then looked at each bill with regard to its initiators and co-sponsors to see if they were members of the same party, members of the opposition or coalition, or members of a minority group. Based on the quantitative analysis, we found that of all of the factors, only being a minority was significant.  Based on the qualitative analysis, we determined that intra-party cooperation does exist. In three parties – Hadash, Meretz and Israel Beitenu -- legislators tended to cooperate with each other. Finally, with regard to inter-party cooperation, Jewish and Arab MKs tended to cooperate, and Russian Jewish legislators tended to cooperate regardless of party affiliation. Our study is innovative in its creation of a cooperation scale that can be used in other legislatures and that is based on measures of co-sponsorship instead of analyses of dyadic or social networks used in previous studies