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.

Oviposition habitat selection by mosquitoes (culiseta longiareolata) and consequences for population size

Abstract: Many kinds of adaptive behavior, including responses to risk of predation, have been documented, but there have been few attempts to translate these behaviors into consequences for populations. We present one of the first models to predict the consequences of adaptive behavior for population size in a specific natural system. Larvae of the mosquito Culiseta longiareolata (Diptera: Culicidae) develop in freshwater pools. They are vulnerable to predation by the backswimmer Notonecta maculata (Hemiptera: Heteroptera), and to intraspecific competition. Adult female C. longiareolata usually avoid ovipositing in pools that contain N. maculata. This is presumably an adaptive response that increases individual fitness, but it is also likely to affect the size of the population. We take a novel approach to understanding the relationship between adaptive behavior and population dynamics in C. longiareolata. We use a nonlinear stage-structured population model to predict the evolutionarily stable oviposition strategy and its consequences for the size of the C. longiareolata population. Our model predicts that female C. longiareolata should always avoid ovipositing in pools with N. maculata. Such avoidance will increase the equilibrium size of the C. longiareolata population, relative to a population in which oviposition is indiscriminate with respect to N. maculata. The qualitative effect on population size is the same even if, as observed, C. longiareolata occasionally oviposit in pools containing N. maculata. These predictions have important practical implications for assessing the effectiveness of predators as biological control agents.

β1-Integrin: A Potential Therapeutic Target in the Battle against Cancer Recurrence

Abstract: Primary cancer treatment, involving both local and often systemic adjuvant therapy, is often successful, especially if the cancer is detected at an early stage of progression. However, for some patients, the cancer may recur either locally or as distant metastases, in some cases many years after apparently successful primary treatment. Significant tumor dormancy has been documented in several cancers, such as breast, melanoma, and renal cancer. Tumor dormancy has long been recognized as an important problem in management of cancer patients. Recent work has clarified biologic aspects of tumor dormancy and has shown that dormant tumor cells may be resistant to cytotoxic chemotherapy and radiation. This work has led to recognition of a key role for β1-integrin in regulating the switch from a dormant state to active proliferation and metastasis. Here we discuss the role of β1-integrin and its signaling partners in regulating the dormant phenotype. We also consider possible therapeutic approaches, such as small molecules or antibodies (ATN-161, volociximab, and JSM6427), directed against β1-integrin signaling to target dormant cancer cells and to prevent metastatic recurrence.

Enhancement of conditioned fear extinction by infusion of the GABAA agonist muscimol into the rat prefrontal cortex and amygdala

Abstract: In auditory fear conditioning, repeated presentation of the tone in the absence of the shock leads to extinction of the acquired fear response. Both the infra limbic prefrontal cortex (IL) and the basolateral amygdala (BLA) are involved in extinction. In this study, we examine the involvement of these two regions in extinction by manipulating the gamma-aminobutyric acid (GABA)ergic system, in the Sprague-Dawley rat. We microinfused a low dose of the GABA(A) agonist muscimol into the IL or BLA. Muscimol infused to IL before extinction training, but not after either a short (five-trials) or long (15-trials) extinction training, resulted in long-term facilitation of extinction. Infusion of muscimol to the BLA following a short (five-trial) extinction session facilitated extinction at least 48-h post-drug infusion. The differences in the temporal parameters of the effects of muscimol in the IL or BLA, suggest differential involvement of these structures in long-term extinction of fear memory. We propose a facilitating role for GABA(A) neurotransmission in the IL in triggering the onset of fear extinction and its maintenance, whereas in the BLA, GABA(A) neurotransmission facilitates extinction consolidation. The involvement of GABA(A) receptors in fear extinction in the prefrontal cortex and amygdala is of particular interest, because of the role of these areas in emotional processes, and the role of the GABA(A) receptors in anxiety states.