פרסומים

מטרה: לבחון את הכוחות המשפיעים על השיח הפוליטי הרב-תרבותי במסלולי ההכשרה לעבודה סוציאלית. נבדקים: 25 מרצים ומחנכים מתחום העבודה הסוציאלית. שיטה וכלי מחקר: הנבדקים השתתפו בראיונות עומק אשר בחנו את יחסם כלפי הדינמיקה הפוליטית במקצועם, תוך התמקדות בסביבות עבודה רב-תרבותיות. מן הממצאים: המונח רב-תרבותיות הומשג במונחים תאוריים, מעשיים וחברתיים-פוליטיים. המרואיינים נמנעו בדרך כלל מלבחון ולהתייחס לנושאים היכולים לבוא במגע עם היבטים פוליטיים בתחום העבודה הסוציאלית. ניתוח הראיונות הצביע על שלושה תהליכים באמצעותם הממד הפוליטי בחינוך לעבודת הרווחה מודר מהשיח המקצועי: העדפתה של תפיסת מיקרו על פני גישת המאקרו; הדרת ה"אחר", תוך השגת מידע עליו; וביסוס יחסי סכסוך בין קבוצות, מחוץ לגבולות השיח.   הממצאים מלמדים על הכוחות המדכאים והמשתיקים את השיח הפוליטי במקצוע העבודה הסוציאלית הרב-תרבותיות.    

Adolescents may engage in risk behaviors to cope with the negative psychological impacts resulting from exposure to political violence. Guided by the Deterioration Deterrence Model and General Strain Theory, the present study assessed the mediating role of school support and posttraumatic stress (PTS) on two adolescent risk behaviors (i.e., school violence and drug use) among Arab and Jewish Israeli adolescents. We analyzed data from a nationally representative survey that consisted of 4,733 Israeli high school students (54.5% females; 63.2% Jewish) following the Second Lebanon War. Structural equation modeling using weighted data bootstrapped with 2,000 iterations evaluated the mediated effects of school support and PTS. The results showed that both school support and PTS mediated the pathways from political violence exposure to school violence and drug use. However, although school support and PTS fully mediated the relationship between political violence exposure and these risk behaviors for Jewish students, school support and PTS only partially mediated the relationships for Arab students. While school support can help decrease the detrimental effect of exposure to terrorism and war, Israeli adolescents exposed to more political violence may perceive receiving less school support than those experiencing less exposure. Findings of this study provide evidence for the theorized mediated pathways between political violence exposure and adolescent risk behaviors by PTS and school support. The study serves as a basis for future research that can unpack the relationship between exposure to political violence and adolescent risk-taking behaviors. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Polyesters derived from the $\alpha$-hydroxy acids, lactic acid, and glycolic acid, are the most common biodegradable polymers in clinical use. These polymers have been tailored for a range of applications that require a physical material possessing. The physical and mechanical properties of these polymers fit the specific application and also safely biodegrade. These polymers are hydrophobic and do not possess functional side groups. This does not allow hydrophilic or hydrophobic manipulation, conjugation of active agents along the polymer chain, etc. These manipulations have partly been achieved by block copolymerization with, for example, poly(ethylene glycol), to obtain an amphiphilic copolymer. The objective of this review is to survey PLA functional copolymers in which functional $\alpha$-hydroxy acids derived from amino acids are introduced along the polymer chain, allowing endless manipulation of PLA. Biodegradable functional polyesters are one of the most versatile biomaterials available to biomedical scientists. Amino acids with their variable side chains are ideal candidates for synthesizing such structural as well as stereochemically diverse polymers. They render control over functionalization, conjugation, crosslinking, stimulus responsiveness, and tunable mechanical/thermal properties. Functionalized amino acid derived polyesters are widely used, mainly due to advancement in ring opening polymerization (primarily O-carboxyanhydride mediated). The reaction proceeds under milder conditions and yields high molecular weight polymers. We reviewed on advances in the synthetic methodologies for poly-$\alpha$-hydroxy esters derived from amino acids with appropriate recent examples.

Polylactide (PLA) and its copolymers are hydrophobic polyesters used for biomedical applications. Hydrogel medicinal implants have been used as drug delivery vehicles and scaffolds for tissue engineering, tissue augmentation and more. Since lactides are non-functional, they are copolymerized with hydrophilic monomers or conjugated to a hydrophilic moiety to form hydrogels. Copolymers of lactic and glycolic acids with poly(ethylene glycol) (PEG) provide thermo-responsive hydrogels. Physical crosslinking mechanisms of PEG-PLA or PLA-polysaccharides include: lactic acid segment hydrophobic interactions, stereocomplexation of D and L-lactic acid segments, ionic interactions, and chemical bond formation by radical or photo crosslinking. These hydrogels may also be tailored as stimulus responsive (pH, photo, or redox). PLA and its copolymers have also been polymerized to include urethane bonds to fabricate shape memory hydrogels. This review focuses on the synthesis, characterization, and applications of PLA containing hydrogels.

Marketing tools that enable pre-purchase experience (e.g., product trials, sampling) are considered efficient means of reducing uncertainty and increasing demand for unfamiliar products. It is widely agreed that having more information improves the quality of choice, so demonstrations, sampling, and other experience-generating marketing tools are expected to increase consumers' welfare. The current paper challenges this concept by suggesting that experiencing some product types for a limited time might provide unrepresentative information, and thus might result in suboptimal choices. In three experiments, we evaluated the effect of potentially unrepresentative experience on consumer product acceptance. The results show that while experiencing products affects consumers even when it provides little information, the effect might be positive or negative, depending on the product value distribution. Specifically, short experience with the product increases the appeal of negatively skewed products, which appear appealing after a short, yet unrepresentative experience. Yet short experience impairs the appeal of positively skewed products, which appear unappealing given short or low-intensity experience. This pattern emerges even though the most likely result of a given sample is not a good predictor of the expected utility of the product. Theoretical and practical implications are discussed.

A concise description of the history, classification, cytology, and botany of potato is presented. The effects of the environment on the morphology, physiology, and development of the potato plant and the adverse effects of high temperatures, drought, and salinity on growth, tuber development, and tuber quality are described. Tuber dormancy and its control in association with storage and with 'seed' tubers' vigor are discussed. Principles of crop production, storage, and tuber quality are presented. © 2017 Elsevier Ltd. All rights reserved.

Circadian rhythms in behaviour and physiology are important for animal health and survival. Studies with individually isolated animals in the laboratory have consistently emphasized the dominant role of light for the entrainment of circadian rhythms to relevant environmental cycles. Although in nature interactions with conspecifics are functionally significant, social signals are typically not considered important time-givers for the animal circadian clock. Our results challenge this view. By studying honeybees in an ecologically relevant context and using a massive data set, we demonstrate that social entrainment can be potent, may act without direct contact with other individuals and does not rely on gating the exposure to light. We show for the first time that social time cues stably entrain the clock, even in animals experiencing conflicting photic and social environmental cycles. These findings add to the growing appreciation for the importance of studying circadian rhythms in ecologically relevant contexts.

Single-cell transcriptomics has been employed in a growing number of animal studies, but the technique has yet to be widely used in plants. Nonetheless, early studies indicate that single-cell RNA-seq protocols developed for animal cells produce informative datasets in plants. We argue that single-cell transcriptomics has the potential to provide a new perspective on plant problems, such as the nature of the stem cells or initials, the plasticity of plant cells, and the extent of localized cellular responses to environmental inputs. Single-cell experimental outputs require different analytical approaches compared with pooled cell profiles and new tools tailored to single-cell assays are being developed. Here, we highlight promising new single-cell profiling approaches, their limitations as applied to plants, and their potential to address fundamental questions in plant biology.

The molecular and cellular mechanisms of enhanced toxic effects in tumor cells of the Pt(IV) derivatives of antitumor oxaliplatin containing axial dichloroacetate (DCA) ligands were investigated. DCA ligands were chosen because DCA has shown great potential as an apoptosis sensitizer and anticancer agent reverting the Wartburg effect. In addition, DCA reverses mitochondrial changes in a wide range of cancers, promoting tumor cell apoptosis in a mitochondrial-dependent pathway. We demonstrate that (i) the transformation of oxaliplatin to its Pt(IV) derivatives containing axial DCA ligands markedly enhances toxicity in cancer cells and helps overcome inherent and acquired resistance to cisplatin and oxaliplatin; (ii) a significant fraction of the intact molecules of DCA conjugates with Pt(IV) derivative of oxaliplatin accumulates in cancer cells where it releases free DCA; (iii) mechanism of biological action of the Pt(IV) derivatives of oxaliplatin containing DCA ligands is connected with the effects of DCA released in cancer cells from the Pt(IV) prodrugs on mitochondria and metabolism of glucose; (iv) treatments with the Pt(IV) derivatives of oxaliplatin containing DCA ligands activate an autophagic response in human colorectal cancer cells; (v) the toxic effects in cancer cells of the Pt(IV) derivatives of oxaliplatin containing DCA ligands can be potentiated if cells are treated with these prodrugs in combination with 5-fluorouracil. These properties of the Pt(IV) derivatives of oxaliplatin containing DCA ligands provide opportunities for further development of new platinum-based agents with the capability of killing cancer cells resistant to conventional antitumor platinum drugs used in the clinic.