Bar-Ilan University

About: Bar-Ilan University is a education organization based out in Ramat Gan, Israel. It is known for research contribution in the topics: Population & Poison control. The organization has 12835 authors who have published 34964 publications receiving 995648 citations. The organization is also known as: Bar Ilan University & BIU.

Power law scaling for a system of interacting units with complex internal structure

Abstract: We study the dynamics of a system composed of interacting units each with a complex internal structure comprising many subunits and treat the case in which each subunit grows in a multiplicative manner. We propose a model for such systems in which the interaction among the units is treated in a mean field approximation and the interaction among subunits is nonlinear. We test the model and find agreement between our predictions and empirical results based on a large economics database spanning 20 years. [S0031-9007(98)05355-1]

More efficient oblivious transfer and extensions for faster secure computation

Abstract: Protocols for secure computation enable parties to compute a joint function on their private inputs without revealing anything but the result. A foundation for secure computation is oblivious transfer (OT), which traditionally requires expensive public key cryptography. A more efficient way to perform many OTs is to extend a small number of base OTs using OT extensions based on symmetric cryptography.In this work we present optimizations and efficient implementations of OT and OT extensions in the semi-honest model. We propose a novel OT protocol with security in the standard model and improve OT extensions with respect to communication complexity, computation complexity, and scalability. We also provide specific optimizations of OT extensions that are tailored to the secure computation protocols of Yao and Goldreich-Micali-Wigderson and reduce the communication complexity even further. We experimentally verify the efficiency gains of our protocols and optimizations. By applying our implementation to current secure computation frameworks, we can securely compute a Levenshtein distance circuit with 1.29 billion AND gates at a rate of 1.2 million AND gates per second. Moreover, we demonstrate the importance of correctly implementing OT within secure computation protocols by presenting an attack on the FastGC framework.

Emotional prejudice, essentialism, and nationalism - The 2002 Tajfel lecture

Abstract: In explaining differences between groups, people ascribe the human essence to their ingroup and consider outgroups as less human. This phenomenon, called infra-humanization, occurs outside people's awareness. Because secondary emotions (e.g. love, hope, contempt, resentment) are considered uniquely human emotions, people not only attribute more secondary emotions to their ingroup than to outgroups, but are reluctant to associate these emotions with outgroups. Moreover, people behave less cooperatively (in terms of altruism, imitation, and approach) with an outgroup member who expresses himself through secondary emotions. Infra-humanization occurs for high and low status groups, even in the absence of conflict between groups. It does not occur when the outgroup target is adequately individualized, by a complete name or through perspective taking, for instance.

Situational versus chronic loneliness as risk factors for all-cause mortality.

Abstract: Background: Several international studies have substantiated the role of loneliness as a risk factor for mortality. Although both theoretical and empirical research has supported the classification of loneliness as either situational or chronic, research to date has not evaluated whether this classification has a differential impact upon mortality.Methods: To establish the definition of situational vs. chronic loneliness, we used three waves of the Health and Retirement Study (HRS), a nationally representative sample of Americans over the age of 50 years. Baseline data for the present study were collected in the years 1996, 1998, and 2000. The present study concerns the 7,638 individuals who completed all three waves; their loneliness was classified as either not lonely, situational loneliness or chronic loneliness. Mortality data were available through to the year 2004.Results: Those identified as “situationally lonely” (HR = 1.56; 95% CI: 1.52–1.62) as well as those identified as “chronically lonely” (HR = 1.83; 95% CI: 1.71–1.87) had a greater risk for all cause mortality net of the effect of possible demographic and health confounders. Nonetheless, relative to those classified as “situationally lonely,” individuals classified as “chronically lonely” had a slightly greater mortality risk.Conclusions: The current study emphasizes the important role loneliness plays in older adults’ health. The study further supports current division into situational vs. chronic loneliness, yet suggests that both types serve as substantial mortality risks.

Redox Mediators for Li-O2 Batteries: Status and Perspectives.

Abstract: Li-O2 batteries have received much attention due to their extremely large theoretical energy density. However, the high overpotentials required for charging Li-O2 batteries lower their energy efficiency and degrade the electrolytes and carbon electrodes. This problem is one of the main obstacles in developing practical Li-O2 batteries. To solve this problem, it is important to facilitate the oxidation of Li2 O2 upon charging by using effective electrocatalysis. Using solid catalysts is not too effective for oxidizing the electronically isolating Li-peroxide layers. In turn, for soluble catalysts, red-ox mediators (RMs) are homogeneously dissolved in the electrolyte solutions and can effectively oxidize all of the Li2 O2 precipitated during discharge. RMs can decompose solid Li2 O2 species no matter their size, morphology, or thickness and thus dramatically increase energy efficiency. However, some negative side effects, such as the shuttle reactions of RMs and deterioration of the Li-metal occur. Therefore, it is necessary to study the activity and stability of RMs in Li-O2 batteries in detail. Herein, recent studies related to redox mediators are reviewed and the mechanisms of redox reactions are illustrated. The development opportunities of RMs for this important battery technology are discussed and future directions are suggested.