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.

Very early warning of next El Niño

Abstract: The most important driver of climate variability is the El Nino Southern Oscillation, which can trigger disasters in various parts of the globe. Despite its importance, conventional forecasting is still limited to 6 mo ahead. Recently, we developed an approach based on network analysis, which allows projection of an El Nino event about 1 y ahead. Here we show that our method correctly predicted the absence of El Nino events in 2012 and 2013 and now announce that our approach indicated (in September 2013 already) the return of El Nino in late 2014 with a 3-in-4 likelihood. We also discuss the relevance of the next El Nino to the question of global warming and the present hiatus in the global mean surface temperature.

The in vivo kinetics of RNA polymerase II elongation during co-transcriptional splicing.

Abstract: RNA processing events that take place on the transcribed pre-mRNA include capping, splicing, editing, 3′ processing, and polyadenylation. Most of these processes occur co-transcriptionally while the RNA polymerase II (Pol II) enzyme is engaged in transcriptional elongation. How Pol II elongation rates are influenced by splicing is not well understood. We generated a family of inducible gene constructs containing increasing numbers of introns and exons, which were stably integrated in human cells to serve as actively transcribing gene loci. By monitoring the association of the transcription and splicing machineries on these genes in vivo, we showed that only U1 snRNP localized to the intronless gene, consistent with a splicing-independent role for U1 snRNP in transcription. In contrast, all snRNPs accumulated on intron-containing genes, and increasing the number of introns increased the amount of spliceosome components recruited. This indicates that nascent RNA can assemble multiple spliceosomes simultaneously. Kinetic measurements of Pol II elongation in vivo, Pol II ChIP, as well as use of Spliceostatin and Meayamycin splicing inhibitors showed that polymerase elongation rates were uncoupled from ongoing splicing. This study shows that transcription elongation kinetics proceed independently of splicing at the model genes studied here. Surprisingly, retention of polyadenylated mRNA was detected at the transcription site after transcription termination. This suggests that the polymerase is released from chromatin prior to the completion of splicing, and the pre-mRNA is post-transcriptionally processed while still tethered to chromatin near the gene end.

A genome-wide map of hyper-edited RNA reveals numerous new sites

Abstract: Adenosine-to-inosine editing is one of the most frequent post-transcriptional modifications, manifested as A-to-G mismatches when comparing RNA sequences with their source DNA. Recently, a number of RNA-seq data sets have been screened for the presence of A-to-G editing, and hundreds of thousands of editing sites identified. Here we show that existing screens missed the majority of sites by ignoring reads with excessive ('hyper') editing that do not easily align to the genome. We show that careful alignment and examination of the unmapped reads in RNA-seq studies reveal numerous new sites, usually many more than originally discovered, and in precisely those regions that are most heavily edited. Specifically, we discover 327,096 new editing sites in the heavily studied Illumina Human BodyMap data and more than double the number of detected sites in several published screens. We also identify thousands of new sites in mouse, rat, opossum and fly. Our results establish that hyper-editing events account for the majority of editing sites.

Hardiness: An examination of its relationship with positive and negative long term changes following trauma

Abstract: Two models positing direct versus moderating effects of hardiness were examined in relation to long term positive and negative changes following exposure to traumatic stress. Participating in the study were 164 Israeli POWs and a matched group of 184 veterans of the 1973 Yom Kippur War. Participants completed a battery of questionnaires that included the Personal Views Survey (hardiness); the Trait, Attitude, and Behavior Change questionnaire; and questions related to their captivity/war experiences. Findings were consistent with a model that posits moderating effects of hardiness on both long term negative and positive changes. The discussion addresses the possible role of hardiness in relation to negative and positive outcomes of traumatic events.