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Institution

Bar-Ilan University

EducationRamat Gan, Israel
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.


Papers
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Journal ArticleDOI
TL;DR: This process is a previously unappriciated mortality mechanism that can lead to the termination of natural Trichodesmium blooms and that can influence the fluxes of organic matter in the ocean.
Abstract: We present experimental laboratory evidence and field observations of an autocatalyzed, programmed cell death (PCD) pathway in the nitrogen-fixing cyanobacteriumTrichodesmium spp., which forms massive blooms in the subtropical and tropical oceans. The PCD pathway was induced in response to phosphorus and iron starvation as well as high irradiance and oxidative stress. Transmission electron microscopy revealed morphological degradation of internal components including thylakoids, carboxysomes, and gas vesicles, whereas the plasma membranes remained intact. Physiologically stressed cells displayed significantly elevated endonuclease activity and terminal d-UTP nick-end labeling. Nucleic acid degradation was concordant with increased immunoreactivity to human caspase-3 polyclonal antisera and enhanced cleavage of a caspase-specific substrate, DEVD. Caspase activity was positively correlated with mortality and was inhibited by the irreversible caspase inhibitor Z-VAD-FMK. A search of the Trichodesmium erythraeumgenome identified several protein sequences containing a conserved caspase domain structure, including the histidine- and cysteine-containing catalytic diad found in true caspases, paracaspases, and metacaspases. Induction of PCD by caspase-like proteases in a bacterial photoautotroph with an ancient evolutionary history requires a reassessment about the origins and roles of cell death cascades. This process is a previously unappriciated mortality mechanism that can lead to the termination of natural Trichodesmium blooms and that can influence the fluxes of organic matter in the ocean.

271 citations

Journal ArticleDOI
Ruth Feldman1
TL;DR: A global 'parental caregiving' network is chart that integrates conserved structures supporting mammalian caregiving with later-evolving networks and implicates parenting in the evolution of higher order social functions aimed at maximizing infant survival.

271 citations

Journal ArticleDOI
TL;DR: It is shown that a synergy exists between the failure of connectivity and dependency links that leads to an iterative process of cascading failures that has a devastating effect on the network stability.
Abstract: Current network models assume one type of links to define the relations between the network entities. However, many real networks can only be correctly described using two different types of relations. Connectivity links that enable the nodes to function cooperatively as a network and dependency links that bind the failure of one network element to the failure of other network elements. Here we present an analytical framework for studying the robustness of networks that include both connectivity and dependency links. We show that a synergy exists between the failure of connectivity and dependency links that leads to an iterative process of cascading failures that has a devastating effect on the network stability. We present exact analytical results for the dramatic change in the network behavior when introducing dependency links. For a high density of dependency links, the network disintegrates in a form of a first-order phase transition, whereas for a low density of dependency links, the network disintegrates in a second-order transition. Moreover, opposed to networks containing only connectivity links where a broader degree distribution results in a more robust network, when both types of links are present a broad degree distribution leads to higher vulnerability.

271 citations

Journal ArticleDOI
TL;DR: A single-nucleotide resolution genomic map of the T. brucei transcriptome is reported, adding 1,114 new transcripts, including 103 non-coding RNAs, confirming and correcting many of the annotated features and revealing an extensive heterogeneity of 5' and 3' ends.
Abstract: The genome of Trypanosoma brucei, the causative agent of African trypanosomiasis, was published five years ago, yet identification of all genes and their transcripts remains to be accomplished. Annotation is challenged by the organization of genes transcribed by RNA polymerase II (Pol II) into long unidirectional gene clusters with no knowledge of how transcription is initiated. Here we report a single-nucleotide resolution genomic map of the T. brucei transcriptome, adding 1,114 new transcripts, including 103 non-coding RNAs, confirming and correcting many of the annotated features and revealing an extensive heterogeneity of 5′ and 3′ ends. Some of the new transcripts encode polypeptides that are either conserved in T. cruzi and Leishmania major or were previously detected in mass spectrometry analyses. High-throughput RNA sequencing (RNA-Seq) was sensitive enough to detect transcripts at putative Pol II transcription initiation sites. Our results, as well as recent data from the literature, indicate that transcription initiation is not solely restricted to regions at the beginning of gene clusters, but may occur at internal sites. We also provide evidence that transcription at all putative initiation sites in T. brucei is bidirectional, a recently recognized fundamental property of eukaryotic promoters. Our results have implications for gene expression patterns in other important human pathogens with similar genome organization (Trypanosoma cruzi, Leishmania sp.) and revealed heterogeneity in pre-mRNA processing that could potentially contribute to the survival and success of the parasite population in the insect vector and the mammalian host.

271 citations

Journal ArticleDOI
TL;DR: A sonochemical decomposition of solutions of volatile organic precursors, Fe(CO)5 and Ni(CO4), in decalin at 273 K, under an oxygen pressure of 100−150 kPa was reported in this article.
Abstract: Nanosized amorphous NiFe2O4 powder was prepared by sonochemical decomposition of solutions of volatile organic precursors, Fe(CO)5 and Ni(CO)4, in decalin at 273 K, under an oxygen pressure of 100−150 kPa. The amorphous nature of these particles was confirmed by various techniques, such as SEM, TEM, electron microdiffraction, and X-ray diffractograms. Magnetic measurements, Mossbauer, and EPR spectral studies indicated that the as-prepared NiFe2O4 ferrite particles were superparamagnetic. The Mossbauer spectrum of the crystallized sample showed a clear sextet pattern, with hyperfine field values of 500 and 508 kOe for A (tetrahedral) and B (octahedral) sublattices, respectively, of the inverse spinel NiFe2O4. Saturation magnetization of the annealed sample (25 emu/g) was significantly lower than that for the reported multidomain bulk prticles (55 emu/g), reflecting the ultrafine nature of the sample. Thermogravimetric measurements with a permanent magnet gave Curie temperatures of 440 °C for amorphous and...

271 citations


Authors

Showing all 13037 results

NameH-indexPapersCitations
H. Eugene Stanley1541190122321
Albert-László Barabási152438200119
Shlomo Havlin131101383347
Stuart A. Aaronson12965769633
Britton Chance128111276591
Mark A. Ratner12796868132
Doron Aurbach12679769313
Jun Yu121117481186
Richard J. Wurtman11493353290
Amir Lerman11187751969
Zhu Han109140748725
Moussa B.H. Youdim10757442538
Juan Bisquert10745046267
Rachel Yehuda10646136726
Michael F. Green10648545707
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023117
2022330
20212,286
20202,157
20191,920
20181,768