University of Haifa

About: University of Haifa is a education organization based out in Haifa, Israel. It is known for research contribution in the topics: Population & Poison control. The organization has 7558 authors who have published 27141 publications receiving 711629 citations. The organization is also known as: Haifa University & Universiṭat Ḥefah.

Mechanisms of Amygdala Modulation of Hippocampal Plasticity

Abstract: Basolateral amygdala (BLA) activation by emotional arousal modulates memory-related processes in the hippocampus. We have shown (Akirav and Richter-Levin, 1999b) that activating the BLA before perforant path (PP) tetanization has a biphasic effect on hippocampal plasticity; priming the BLA immediately before PP tetanization results in the enhancement of dentate gyrus (DG) long-term potentiation (LTP) (an "emotional tag"), whereas stimulation in a spaced interval results in the suppression of DG-LTP. Here, we aimed to elucidate the mechanisms underlying BLA modulation of DG-LTP and specifically to examine whether the stress hormones norepinephrine (NE) and corticosterone (CORT) are main mediators of the BLA biphasic effects. We found that the BLA affects hippocampal plasticity in a complex manner; BLA priming enhanced DG-LTP, and both NE and CORT mediated this effect. Furthermore, we found that ipsilateral BLA spaced activation (2 hr before PP tetanization) suppressed DG-LTP and that this suppressive effect was also mediated by NE and CORT. Priming the contralateral BLA enhanced DG-LTP similarly to the ipsilateral enhancement, but neither NE nor CORT mediated this effect. The spaced activation of the contralateral BLA did not suppress DG-LTP. Taken together, these results suggest that differential mechanisms underlie the ipsilateral and contralateral BLA effects on hippocampal plasticity. Hence, the BLA modulates hippocampal memory processes, presumably via the mediation of the stress hormones NE and CORT, to establish a diverse memory of the experience. Possibly, at the onset of an emotional event the stress hormones permissively mediate plasticity. However, their prolonged presence in the system may suppress the cognitive response to stress.

Plant-Mediated Interactions Between Whiteflies, Herbivores, and Natural Enemies

Abstract: Whiteflies (Homoptera: Aleyrodidae) comprise tiny phloem-sucking insects. The sessile development of their immatures and their phloem-feeding habits (with minimal physical plant damage) often lead to plant-mediated interactions with other organisms. The main data come from the polyphagous pest species Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood), which are intricately associated with their host plants. Although these associations might not represent aleyrodids in general, we rely on them to highlight the fundamental role of host plants in numerous ecological interactions between whiteflies, other herbivores, and their natural enemies. Plant traits often affect the activity, preference, and performance of the whiteflies, as well as their entomopathogens, predators, and parasitoids. Leaf structure (primarily pubescence) and constitutive and induced chemical profiles (defensive and nutritional elements) are critically important determinants of whitefly fitness. Pest management-related and evolutionary biology studies could benefit from future research that will consider whiteflies in a multitrophic-level framework.

The effects of web personalization on user attitude and behavior: an integration of the elaboration likelihood model and consumer search theory

Abstract: Web personalization can achieve two business goals: increased advertising revenue and increased sales revenue. The realization of the two goals is related to two kinds of user behavior: item sampling and item selection. Prior research does not provide a model of attitude formation toward a personalization agent nor of how attitudes relate to these two behaviors. This limits our understanding of how web personalization can be managed to increase advertising revenues and/or sales revenues. To fill this gap, the current research develops and tests a theoretical model of user attitudes and behaviors toward a personalization agent. The model is based on an integration of two theories: the elaboration likelihood model (ELM) and consumer search theory (CST). In the integrated model, a user's attitude toward a personalization agent is influenced by both the number of items he/she has sampled so far (from CST) and the degree to which he/she cognitively processes each one (from ELM). In turn, attitude is modeled to influence both behaviors--that is, item selection and any further item sampling. We conducted a lab study and a field study to test six hypotheses. This research extends the theory on web personalization by providing a more complete picture of how sampling and processing of personalized recommendations influence a user's attitude and behavior toward the personalization agent. For online merchants, this research highlights the trade-off between item sampling and item selection and provides practical guidance on how to steer users toward the attitudes and behaviors that will realize their business goals.

Tibet is one of the centers of domestication of cultivated barley

Abstract: The Near East Fertile Crescent is well recognized as a primary center of barley origin, diversity, and domestication. A large number of wild barleys have been collected from the Tibetan Plateau, which is characterized by an extreme environment. We used genome-wide diversity array technology markers to analyze the genotypic division between wild barley from the Near East and Tibet. Our results confirmed the existence of Tibetan wild barley and suggested that the split between the wild barleys in the Near East and those in Tibet occurred around 2.76 million years ago (Mya). To test the concept of polyphyletic domestication of barley, we characterized a set of worldwide cultivated barley. Some Chinese hulless and six-rowed barleys showed a close relationship with Tibetan wild barley but showed no common ancestor with other cultivated barley. Our data support the concept of polyphyletic domestication of cultivated barley and indicate that the Tibetan Plateau and its vicinity is one of the centers of domestication of cultivated barley. The current results may be highly significant in exploring the elite germplasm for barley breeding, especially against cold and drought stresses.

Ultra-Low-Dose Buprenorphine as a Time-Limited Treatment for Severe Suicidal Ideation: A Randomized Controlled Trial.

Abstract: Objective:Suicidal ideation and behavior currently have no quick-acting pharmacological treatments that are suitable for independent outpatient use. Suicidality is linked to mental pain, which is modulated by the separation distress system through endogenous opioids. The authors tested the efficacy and safety of very low dosages of sublingual buprenorphine as a time-limited treatment for severe suicidal ideation.Method:This was a multisite randomized double-blind placebo-controlled trial of ultra-low-dose sublingual buprenorphine as an adjunctive treatment. Severely suicidal patients without substance abuse were randomly assigned to receive either buprenorphine or placebo (in a 2:1 ratio), in addition to their ongoing individual treatments. The primary outcome measure was change in suicidal ideation, as assessed by the Beck Suicide Ideation Scale at the end of each of 4 weeks of treatment.Results:Patients who received ultra-low-dose buprenorphine (initial dosage, 0.1 mg once or twice daily; mean final dos...