475 research outputs found
Learning Good Electronics or Coping With Challenging Tasks: The Priorities of Excellent Students
No full textThis paper, from Moshe Barak of the Department of Education in Science and Technology at Ben-Gurion University of the Negev, covers the state of high school technology education in Israel. A background is given, as well as research goals, analysis, and findings
Pulsed electromagnetic fields increase osteogenetic commitment of MSCs via the mTOR pathway in TNF-alpha mediated inflammatory conditions: an in-vitro study
No full textPulsed electromagnetic fields (PEMFs) have been considered a potential treatment modality for fracture healing, however, the mechanism of their action remains unclear. Mammalian target of rapamycin (mTOR) signaling may affect osteoblast proliferation and differentiation. This study aimed to assess the osteogenic differentiation of mesenchymal stem cells (MSCs) under PEMF stimulation and the potential involvement of mTOR signaling pathway in this process. PEMFs were generated by a novel miniaturized electromagnetic device. Potential changes in the expression of mTOR pathway components, including receptors, ligands and nuclear target genes, and their correlation with osteogenic markers and transcription factors were analyzed. Involvement of the mTOR pathway in osteogenesis was also studied in the presence of proinflammatory mediators. PEMF exposure increased cell proliferation and adhesion and the osteogenic commitment of MSCs even in inflammatory conditions. Osteogenic-related genes were over-expressed following PEMF treatment. Our results confirm that PEMFs contribute to activation of the mTOR pathway via upregulation of the proteins AKT, MAPP kinase, and RRAGA, suggesting that activation of the mTOR pathway is required for PEMF-stimulated osteogenic differentiation. Our findings provide insights into how PEMFs influence osteogenic differentiation in normal and inflammatory environments
Parameterized Complexity of Critical Node Cuts
No full textWe consider the following graph cut problem called Critical Node Cut (CNC): Given a graph G on n vertices, and two positive integers k and x, determine whether G has a set of k vertices whose removal leaves G with at most x connected pairs of vertices. We analyze this problem in the framework of parameterized complexity. That is, we are interested in whether or not this problem is solvable in f(kappa) * n^{O(1)} time (i.e., whether or not it is fixed-parameter tractable), for various natural parameters kappa. We consider four such parameters:
- The size k of the required cut.
- The upper bound x on the number of remaining connected pairs.
- The lower bound y on the number of connected pairs to be removed.
- The treewidth w of G.
We determine whether or not CNC is fixed-parameter tractable for each of these parameters. We determine this also for all possible aggregations of these four parameters, apart from w+k. Moreover, we also determine whether or not CNC admits a polynomial kernel for all these parameterizations. That is, whether or not there is an algorithm that reduces each instance of CNC in polynomial time to an equivalent instance of size kappa^{O(1)}, where kappa is the given parameter
Economic utopia of the Torah. Economic concepts of the Hebrew Bible interpreted according to the Rabbinical Literature
No full textHebrew Bible offers alternative Economic utopia for building Theocratic society. In this paper, various economic concepts and themes are presented, as found in the Hebrew Bible. These economic concepts include taxation, property rights, labor market, social policy, banking, years of Sabbath and Jubilee, and business cycles. Most economic issues of the Bible are found in the texts of Torah, also known as five Books of Moses. These texts are analyzed by using classical Rabbinical commentaries for better insight. Contrary to the modern Economic theory which is based on the assumptions of scarcity of resources and unlimited needs of consumers, Economics of the Torah is based on God’s resources which are enough for all true needs of His people.Hebrew Bible, History of Economics, History of Economic Thought, Ancient Israel, Judaism
Lessons from the Israeli-Egyptian peace talks: An interview with Aharon Barak
No full textThis article is based on an interview conducted in July 2018 with Aharon Barak. In it, Barak reflects on the peace negotiations with Egypt at Camp David during 13 days in September 1978. While expressing great appreciation for the American negotiating team, first and foremost for President Jimmy Carter, for bringing the talks to a successful close, Barak considers negotiating with Carter as the toughest experience of his life. According to Barak, who had just completed his role as legal advisor to the government (1975-1978) and was appointed to the Supreme Court, the key people in the Israeli delegation were Menachem Begin, Moshe Dayan, and Ezer Weizman, while the key players in the Egyptian delegation were Anwar Sadat and Osama El-Baz. The negotiations went through ups and downs and had reached the brink of collapse until the Americans proposed that Carter negotiate directly with El-Baz and Barak. In the article's conclusion, some important insights are deduced from this interview for future, successful negotiations
The Quest for Citations: Drivers of Article Impact
No full textWhy do some articles become building blocks for future scholars, while many others remain unnoticed? We aim to answer this question by contrasting, synthesizing and simultaneously testing three scientometric perspectives – universalism, social constructivism and presentation – on the influence of article and author characteristics on article citations. To do so, we study all articles published in a sample of five major journals in marketing from 1990 to 2002 that are central to the discipline. We count the number of citations each of these articles has received and regress this count on an extensive set of characteristics of the article (i.e. article quality, article domain, title length, the use of attention grabbers and expositional clarity), and the author (i.e. author visibility and author personal promotion). We find that the number of citations an article in the marketing discipline receives, depends upon “what one says†(quality and domain), on “who says it†(author visibility and personal promotion) and not so much on “how one says it†(title length, the use of attention grabbers, and expositional clarity). Our insights contribute to the marketing literature and are relevant to scientific stakeholders, such as the management of scientific journals and individual academic scholars, as they strive to maximize citations. They are also relevant to marketing practitioners. They inform practitioners on characteristics of the academic journals in marketing and their relevance to decisions they face. On the other hand, they also raise challenges towards making our journals accessible and relevant to marketing practitioners: (1) authors visible to academics are not necessarily visible to practitioners; (2) the readability of an article may hurt academic credibility and impact, while it may be instrumental in influencing practitioners; (3) it remains questionable whether articles that academics assess to be of high quality are also managerially relevant.Impact;Citation Analysis;Referencing;Scientometrics;Cite
A new device for improving dental implants anchorage: a histological and micro-computed tomography study in the rabbit.
No full textObjective: In the present study, a new healing cap that could generate a pulsed electromagnetic field (PEMF) around titanium implants to stimulate peri-implant osteogenesis was tested in the rabbit model.
Materials and methods: A total of 22 implants were inserted in the proximal tibial metaphysis of 22 rabbits. A healing cap containing the active device was inserted in half of the implants (11 test implants); an "empty" healing cap was inserted in the other ones (11 control implants). The animals were euthanized after 2 and 4 weeks, and the samples were processed for micro-computed tomography and histology. The peri-implant volume was divided into coronal (where the PEMF was the strongest) and apical regions.
Results: Most of the effects of the tested device were confined to the coronal region. Two weeks post-implantation, test implants showed a significant 56% higher trabecular bone fraction (BV/TV), associated with enhanced trabecular number (Tb.N, +37%) and connectivity density (Conn.D, +73%) as compared to the control group; at 4 weeks, the PEMF induced a 69% increase in BV/TV and 34% increase of Tb.N. There was no difference in the trabecular thickness (Tb.Th) at either time point. Furthermore, we observed a 48% higher bone-to-implant contact (BIC) in the test implants vs. controls after 2 weeks; this increase tended to remain stable until the fourth week. Mature trabecular and woven bone were observed in direct contact with the implant surface with no gaps or connective tissue at the bone-implant interface.
Conclusions: These results indicate that the PEMF device stimulated early bone formation around dental implants resulting in higher peri-implant BIC and bone mass already after 2 weeks which suggests an acceleration of the osseointegration process by more than three times
"Sefer beer Moshe" by Moshe Sertels, son of Isachar, as an example of a bilingual text for the study of the Torah
No full textMoshe Sertels was a son of Issachar and Sarah. He was born circa mid-16th century in Prague. He was a teacher and worked as a translator and exegete. Sertels wrote several texts that attracted wide interest. One of them was a work titled Sefer Beer Moshe, a bilingual commentary on the Torah and five megillot. The construction of the text, its clarity and intelligibility, made it an excellent tool for teaching the Torah in cheders (e.g. such usage of this text was noted in the books of the Cracovian brotherhood Talmud Torah). The article presents the figure of the author and his literary oeuvre with particular focus on the Sefer Beer Moshe as a work that served generations of Ashkenazi Jews to enhance their knowledge of the Torah. The author discusses characteristics of the text and underlines several issues in regard to the Yiddish language in the form that was used in Prague at the turn of the 17th century
Dead Sea Scrolls at Sixty: What HAVE they taught us? What CAN they teach us? What can they NOT teach us?
No full textScholar-in-residence, 2007. Dr. Moshe J. Bernstein, Associate Professor of Bible, Yeshiva University, and author of New Perspectives on Qumran Law and History.https://digitalcommons.fairfield.edu/bennettcenter-posters/1250/thumbnail.jp
WHO IS RABBI MOSHE \u27YAẔ\u27?
No full textThe name Rabbi Moshe \u27Yaẕ\u27 (י\u27ץ = yishmerehu ẕuro) appears in two letters written, and published, by Rabbi Saul Berlin in 1789 and 1790, respectively, in connection with the Miẕpeh Yoqte\u27el controversy. Accepting the view that Rabbi Moshe is a fictional character, the author suggests the following explanation for the usage of this name: The opening section of the first letter, which has been overlooked by the scholars, provides a clue to the identification. It reads: \u27Moshe Bar \u27Eẕri\u27, a name which appears twice in the Talmud (Baba Batra 174b; Arakhin 23a). The Talmud relates the story of Moshe Bar \u27Eẕri who was the guarantor of his daughter-in-law\u27s Ketubah. His son, Rav Huna, a student, who was pressed hard for money, was unable to implement the advice given him: to divorce his wife so that she should collect money guaranteed by his father, following which they would remarry. Since Rav Huna was a priest, he would not be permitted to remarry his divorcee. The use of the talmudic name is therefore intended to allude to Saul Berlin\u27s special predicament, to the advantages and disadvantages of attempting to secure some assistance from his father, the venerable Ẕevi Hirsch Levin, Rabbi of the Berlin community. Indeed, his father endeavoured to help him, but to no avail. Saul Berlin lost his position as Rabbi in Frankfort, has been considered excommunicated by some, and finally had to go into exile; he died in London shortly after
- …
