670 research outputs found

    Study of adhesion and cohesion in vacuum fifth quarterly report, 1 oct. 1964 - 1 jan. 1965

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    Adhesion and cohesion tests under static loading conditions in vacuum - aluminum and titanium alloys and copper bondin

    Targeted Disruption of the Low-Affinity Leukemia Inhibitory Factor-Receptor Gene Causes Placental, Skeletal, Neural and Metabolic Defects and Results in Perinatal Death

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    The low-affinity receptor for leukemia inhibitory factor (LIFR)* interacts with gp130 to induce an intracellular signal cascade, The LIFR-gp130 heterodimer is implicated in the function of diverse systems, Normal placentation is disrupted in LIFR mutant animals, which leads to poor intrauterine nutrition but allows fetuses to continue to term. Fetal bone volume is reduced greater than three-fold and the number of osteoclasts is increased six-fold, resulting in severe osteopenia of perinatal bone. Astrocyte numbers are reduced in the spinal cord and brain stem. Late gestation fetal livers contain relatively high stores of glycogen, indicating a metabolic disorder. Hematologic and primordial germ cell compartments appear normal. Pleiotropic defects in the mutant animals preclude survival beyond the day of birth

    An experimentally-achieved information-driven Brownian motor shows maximum power at the relaxation time

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    We present an experimental realization of an information-driven Brownian motor by periodically cooling a Brownian particle trapped in a harmonic potential connected to a single heat bath, where cooling is carried out by the information process consisting of measurement and feedback control. We show that the random motion of the particle is rectified by symmetry-broken feedback cooling where the particle is cooled only when it resides on the specific side of the potential center at the instant of measurement. Studying how the motor thermodynamics depends on cycle period tau relative to the relaxation time tau(B) of the Brownian particle, we find that the ratcheting of thermal noise produces the maximum work extraction when tau >= 5 tau(B) while the extracted power is maximum near tau= tau(B), implying the optimal operating time for the ratcheting process. In addition, we find that the average transport velocity is monotonically decreased as tau increases and present the upper bound for the velocity

    Метафизическое значение категорий предмета и непредмета в логике, поясняемое примерами решения антиномии Рассела в теории типов и аксиоматической системе NBG

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    Метафизическое значение категорий предмета и непредмета в логике, поясняемое примерами решения антиномии Рассела в теории типов и аксиоматической системе NB

    Differences in trait impulsivity indicate diversification of dog breeds into working and show lines

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    Impulsiveness describes the inability to inhibit behaviour in the presence of salient cues. Trait-level impulsivity exists on a continuum and individual differences can be adaptive in different contexts. While breed related differences in behavioural tendency in the domestic dog (Canis familiaris) are well established, the phenomenon within lines of a breed which have been selected more recently is not well studied, although it may challenge the popular notion of breed-typical behaviour. We describe differences in impulsivity between and within two dog breeds with working and show lines selected for different levels of impulsivity: Border Collies (herding work) and Labrador Retrievers (gun work). Recent show line selection might have lessened differences in impulsivity between breeds. We tested this hypothesis on a dataset of 1161 individuals assessed using a validated psychometric tool (Dog Impulsivity Assessment Scale - DIAS). Collies were more impulsive on average, consistent with the original purpose of breed selection. Regarding line, working Collies differed from working Labradors, but show lines from the two breeds were not significantly different. Altered or relaxed artificial selection for behavioural traits when appearance rather than behaviour become the primary focus for breeders may reduce average differences in impulsivity between breeds in show lines

    Daidzein Prevents the Increase in CD4+CD28null T Cells and B Lymphopoesis in Ovariectomized Mice: A Key Mechanism for Anti-Osteoclastogenic Effect

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    Estrogen deficiency leads to an upregulation of TNF-α producing T cells and B-lymphopoesis which augments osteoclastogenesis. Estrogen deficiency also increases the population of premature senescent CD4+CD28null T cells which secrete a higher amount of TNF-α thus leading to enhanced osteoclastogenesis. Isoflavonoids like daidzein and genistein are found mostly in soybeans, legumes, and peas. These share structural similarity with 17β-stradiol (E2) and have osteoprotective role. This study explores the effect of daidzein (Daid) on the proliferation of TNF-α producing T cells, premature senescent T cells and B cell lymphopoesis under estrogen deficient conditions. For this study adult Balb/c mice were treated with Daid at 10 mg/kg body weight dose by oral gavage daily post ovariectomy (Ovx). After six weeks animals were autopsied and bone marrow and spleen cells were collected for FACS analysis. Blood serum was collected for ELISA. It was observed that Ovx mice treated with Daid for six weeks show reduction in Ovx induced expansion of CD4+ T cells in bone marrow and spleen when analysed by flow cytometry. Estrogen deficiency led to increased prevalence of TNF-α secreting CD4+CD28null T cells, however, treatment with Daid increased the percentage of CD4+CD28+ T cells. Co-culture of CD4+CD28null T cells and bone marrow resulted in enhanced osteoclastogenesis as evident by increased tartarate resistant acid phosphatase (TRAP) expression, an osteoclast marker. However, treatment with Daid resulted in reduced osteoclastogenesis in CD4+CD28null T cells and bone marrow cell co-culture. Daid also regulated B lymphopoesis and decreased mRNA levels of RANKL in B220+ cells. Taken together, we propose that one of the mechanisms by which Daid prevents bone loss is by reversing the detrimental immune changes as a result of estrogen deficiency
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