180 research outputs found

    A VEGF-A splice variant defective for heparan sulfate and neuropilin-1 binding shows attenuated signaling through VEGFR-2

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    Abstract.: The development of functional blood and lymphatic vessels requires spatio-temporal coordination of the production and release of growth factors such as vascular endothelial growth factors (VEGFs). VEGF family proteins are produced in multiple isoforms with distinct biological properties and bind to three types of VEGF receptors. A VEGF-A splice variant, VEGF-A165b, has recently been isolated from kidney epithelial cells. This variant is identical to VEGF-A165 except for the last six amino acids encoded by an alternative exon. VEGF-A165b and VEGF-A165 bind VEGF receptors 1 and 2 with similar affinity. VEGF-A165b elicits drastically reduced activity in angiogenesis assays and even counteracts signaling by VEGF-A165. VEGF-A165b weakly binds to heparan sulfate and does not interact with neuropilin-1, a coreceptor for VEGF receptor 2. To determine the molecular basis for altered signaling by VEGF-A165b we measured VEGF receptor 2 and ERK kinase activity in endothelial cells in culture. VEGF-A165 induced strong and sustained activation of VEGF receptor 2 and ERK-1 and −2, while activation by VEGF-A165b was only weak and transient. Taken together these data show that VEGF-A165b has attenuated signaling potential through VEGF receptor 2 defining this new member of the VEGF family as a partial receptor agonis

    Концептуальные основы региональной образовательной политики

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    У монографії висвітлено концептуальні засади регіональної освітньої політики, об’єктивовані в теоретичному описі основних підходів, принципів, умов реалізації концепції навчання впродовж життя як чинника регіональної розвитку. Проаналізовано основні передумови розроблення концепції освіти впродовж життя у світі та соціально-економічні результати її упровадження. Викладено особливості та специфіку освіти впродовж життя, освіти дорослих як її складової в умовах регіонального розвитку (національний і зарубіжний досвід). Охарактеризовано психологічні особливості розвитку особистості в дорослому віці, а також професійного становлення особистості на різних етапах дорослості. Висвітлено роль неформальної освіти дорослих як чинника розвитку регіонів, що навчаються, а також механізми розроблення та реалізації концепції міста, регіону, що навчається. Інтерпретовано результати соціологічного дослідження культурно-освітніх потреб жителів Запорізької обл. та рівня їх задоволеності.The monograph describes the conceptual foundations of regional educational policy, objectified in the theoretical description of the main approaches, principles, conditions to implement the lifelong learning concept as a factor of regional development. The basic prerequisites for the development of lifelong learning concept in the world and the socio-economic results of its implementation are analyzed. The peculiarities and specifics of lifelong learning, education of adults as a part of it in the conditions of regional development (national and foreign experience) are described. The psychological peculiarities of personality development in adulthood as well as professional development of personality at different stages of adolescence are characterized. The role of non-formal adults education as a factor of learning regions development as well as mechanisms of the city development and implementation of the concept is highlighted. The results of sociological research of cultural and educationalneeds of Zaporizhzhya region's residents and their level of satisfaction are interpreted.В монографии освещены концептуальные основы региональной образовательной политики, объективированные в теоретическом описании основных подходов, принципов, условий реализации концепции непрерывного обучения как фактора регионального развития. Проанализированы основные предпосылки для разработки концепции обучения на протяжении всей жизни в мире и социально-экономических результатов ее реализации. Описаны особенности и специфика обучения на протяжении всей жизни, образования взрослых как его составляющей в условиях регионального развития (национальный и зарубежный опыт). Охарактеризованы психологические особенности развития личности во взрослом возрасте, а также профессиональное развитие личности на разных этапах подросткового возраста. Освещена роль неформального образования взрослых как фактора развития обучающихся регионов, а также механизмы разработки и реализации концепции обучающихся городов

    Biophysical forcing of particle production and distribution during a spring bloom in the North Atlantic

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    Abstract: The beam attenuation serves as a proxy for particulate matter and is a key parameter in visibility algorithms for the aquatic environment. It is well known, however, that the beam attenuation is a function of the acceptance angle of the transmissometer used to measure it. Here we compare eight different transmissometers with four different acceptance angles using four different deployment strategies and sites, and find that their mean attenuation values differ markedly and in a consistent way with instrument acceptance angle: smaller acceptance angles provide higher beam attenuation values. This difference is due to variations in scattered light collected with different acceptance angles and is neither constant nor easy to parameterize. Variability (in space or time) in the ratios of beam attenuations measured by two different instruments correlates, in most cases, with the particle size parameter (as expected from Mie theory), but this correlation is often weak and can be the opposite of expectations based on particle size changes. We recommended careful consideration of acceptance angle in applications of beam transmission data especially when comparing data from different instruments

    Biophysical forcing of particle production and distribution during a spring bloom in the North Atlantic

    Get PDF
    Abstract: The beam attenuation serves as a proxy for particulate matter and is a key parameter in visibility algorithms for the aquatic environment. It is well known, however, that the beam attenuation is a function of the acceptance angle of the transmissometer used to measure it. Here we compare eight different transmissometers with four different acceptance angles using four different deployment strategies and sites, and find that their mean attenuation values differ markedly and in a consistent way with instrument acceptance angle: smaller acceptance angles provide higher beam attenuation values. This difference is due to variations in scattered light collected with different acceptance angles and is neither constant nor easy to parameterize. Variability (in space or time) in the ratios of beam attenuations measured by two different instruments correlates, in most cases, with the particle size parameter (as expected from Mie theory), but this correlation is often weak and can be the opposite of expectations based on particle size changes. We recommended careful consideration of acceptance angle in applications of beam transmission data especially when comparing data from different instruments

    Revisiting and modelling the woodland farming system of the early Neolithic Linear Pottery Culture (LBK), 5600–4900 B.C

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    International audienceThis article presents the conception and the conceptual results of a modelling representation of the farming systems of the Linearbandkeramik Culture (LBK). Assuming that there were permanent fields (PF) then, we suggest four ways that support the sustainability of such a farming system over time: a generalized pollarding and coppicing of trees to increase the productivity of woodland areas for foddering more livestock, which itself can then provide more manure for the fields, a generalized use of pulses grown together with cereals during the same cropping season, thereby reducing the needs for manure. Along with assumptions limiting bias on village and family organizations, the conceptual model which we propose for human environment in the LBK aims to be sustainable for long periods and can thereby overcome doubts about the PFs hypothesis for the LBK farming system. Thanks to a reconstruction of the climate of western Europe and the consequent vegetation pattern and productivity arising from it, we propose a protocol of experiments and validation procedures for both testing the PFs hypothesis and defining its eco-geographical area
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