573 research outputs found

    Quasifree Knockout Of Deuterons In The ⁶Li(α,αd)⁎He Reaction At 23.6 MeV

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    α−d correlations in quasi-elastic scattering of 23.6-MeV α particles on the deuteron cluster of the ⁶Li target were measured in and off the principal reaction plane. Despite the low c.m. energy of 14.2 MeV, the impulse approximation provides a reasonable description of the quasifree process. Computations were based on the asymptotic α−d S-state wave function and on the cluster-model wave function of ⁶Li. Insensitivity of the fits to the details of the ⁶Li cluster-model wave function indicates an extreme surface reaction mechanism. The full width at half-maximum of the spectator momentum distribution was found to be 48±6 MeV/c. By comparing the experimental cross section for the quasifree process at the maximum of the angular correlation ((d2σ/dΩddΩ)=68±9 mb/srÂČ at Ξ=25°,Ξ(d)=45°) with the corresponding cross section for the free process, the probability of finding ⁶Li as an α−d cluster was evaluated

    Repeated exposure to chlorpyrifos is associated with a dose-dependent chronic neurobehavioral deficit in adult rats

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    Organophosphate (OP) chemicals include commonly used pesticides and chemical warfare agents, and mechanistically they are potent inhibitors of the cholinesterase (ChE) enzyme. Epidemiological studies report long-term neuropsychiatric issues, including depression and cognitive impairments in OP-exposed individuals. Chlorpyrifos (CPF) is one of the most widely used pesticides worldwide. Multiple laboratory studies have reported on either the long-term behavioral effect of an acute high-dose CPF (30-250 mg/kg) or studied sub-chronic behavioral effects, particularly the motor and cognitive effects of repeated low-dose CPF. However, studies are lacking on chronic mood and depression-related morbidities following repeated CPF doses that would mimic occupationally relevant OP exposures. In this study, adult male rats were injected with CPF (1, 3, 5, or 10 mg/kg/d, s.c.) for 21 consecutive days. Dependent on the CPF dose, ChE activity was inhibited approximately 60-80% in the blood and about 20-50% in the hippocampus at 2-days after the end of CPF exposures. Following a 12-week washout period, a complete recovery of ChE activity was noted. However, CPF-treated rats exhibited a dose-dependent increase in signs related to anhedonia (sucrose preference test), anxiety (open-field and elevated plus-maze), and despair (forced swim test) at this stage. To the best of our knowledge, this could be the first laboratory study that demonstrates a cause-effect relationship between occupational-like CPF exposures in adult rats and the development of long-term depression-related outcomes and could provide an experimental system to study molecular mechanisms underlying environmental OP exposures and the elevated risk for chronic behavioral deficits

    Groundwater modeling in shales at a steep hill near Jena

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    Water flow and water storage in hill slopes have a strong interest in the hydrological scientific community. The use of the gravimetrical signal of superconducting gravimeters can help to understand water flow in such areas. At the Geodynamic Observatory Moxa of the Friedrich Schiller University Jena (Germany), the relation between hill slope hydrological processes and gravity residuals are investigated. For this purpose a linear reservoir model was developed to quantify canopy storage and storage changes in the unsaturated zone. A groundwater flow model (MODFLOW) was developed to quantify flow in fractured shales. Cross correlation showed significant gravimetrical response on heavy precipitation events after a dry period. The groundwater model simulated the expected flow patterns reasonably well

    Analysis of the intraspinal calcium dynamics and its implications on the plasticity of spiking neurons

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    The influx of calcium ions into the dendritic spines through the N-metyl-D-aspartate (NMDA) channels is believed to be the primary trigger for various forms of synaptic plasticity. In this paper, the authors calculate analytically the mean values of the calcium transients elicited by a spiking neuron undergoing a simple model of ionic currents and back-propagating action potentials. The relative variability of these transients, due to the stochastic nature of synaptic transmission, is further considered using a simple Markov model of NMDA receptos. One finds that both the mean value and the variability depend on the timing between pre- and postsynaptic action-potentials. These results could have implications on the expected form of synaptic-plasticity curve and can form a basis for a unified theory of spike time-dependent, and rate based plasticity.Comment: 14 pages, 10 figures. A few changes in section IV and addition of a new figur

    Circulating Cell-Free DNA in Dogs with Mammary Tumors: Short and Long Fragments and Integrity Index

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    Circulating cell-free DNA (cfDNA) has been considered an interesting diagnostic/prognostic plasma biomarker in tumor-bearing subjects. In cancer patients, cfDNA can hypothetically derive from tumor necrosis/apoptosis, lysed circulating cells, and some yet unrevealed mechanisms of active release. This study aimed to preliminarily analyze cfDNA in dogs with canine mammary tumors (CMTs). Forty-four neoplastic, 17 non-neoplastic disease-bearing, and 15 healthy dogs were recruited. Necrosis and apoptosis were also assessed as potential source of cfDNA on 78 CMTs diagnosed from the 44 dogs. The cfDNA fragments and integrity index significantly differentiated neoplastic versus non-neoplastic dogs (P<0.05), and allowed the distinction between benign and malignant lesions (P<0.05). Even if without statistical significance, the amount of cfDNA was also affected by tumor necrosis and correlated with tumor size and apoptotic markers expression. A significant (P<0.01) increase of Bcl-2 in malignant tumors was observed, and in metastatic CMTs the evasion of apoptosis was also suggested. This study, therefore, provides evidence that cfDNA could be a diagnostic marker in dogs carrying mammary nodules suggesting that its potential application in early diagnostic procedures should be further investigated

    Bisulfite-free analysis of 5MeC-binding proteins and locus-specific methylation density using a microparticle-based flow cytometry assay

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    DNA methylation analysis is emerging as a new technique with potential capabilities for early cancer detection. However, current state-of-the-art techniques are not easily translatable into routine clinical methods. Herein we describe a bead-based flow cytometry assay which combines DNA hybridization to microparticles with 5MeC-specific proteins/antibodies. These assays can be used to study the binding properties of current and emerging 5MeC-binding proteins and may also have potential in the measurement of 5MeC density in clinical samples for cancer detection

    Software project planning through comparison of Bio-inspired algorithms

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    Currently many organizations have adopted the development of software projects with agile methodologies, particularly Scrum, which has more than 20 years of development. In these methodologies, software is developed iteratively and delivered to the client in increments called releases. In the releases, the goal is to develop system functionality that quickly adds value to the client’s business. At the beginning of the project, one or more releases are planned. For solving the problem of replanning in the context of releases, a model is proposed considering the characteristics of agile development using Scrum. The results obtained show that the algorithm takes a little less than 7 min for solutions that propose replanning composed by 16 sprints, which is equivalent to 240 days of project. They show that applying a repair operator increases the hypervolume qualit

    Sedentary behaviour and brain health in middle-aged and older adults: A systematic review

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    Sedentary behaviour may increase the risk of dementia. Studying physiological effects of sedentary behaviour on cerebral health may provide new insights into the nature of this association. Accordingly, we reviewed if and how acute and habitual sedentary behaviour relate to brain health factors in middle-aged and older adults (≄45 years). Four databases were searched. Twenty-nine studies were included, with mainly cross-sectional designs. Nine studies examined neurotrophic factors and six studied functional brain measures, with the majority of these studies finding no associations with sedentary behaviour. The results from studies on sedentary behaviour and cerebrovascular measures were inconclusive. There was a tentative association between habitual sedentary behaviour and structural white matter health. An explanatory pathway for this effect might relate to the immediate vascular effects of sitting, such as elevation of blood pressure. Nevertheless, due to the foremost cross-sectional nature of the available evidence, reverse causality could also be a possible explanation. More prospective studies are needed to understand the potential of sedentary behaviour as a target for brain health

    Editorial note for the Geodesy and Geodynamics journal special issue Contemporary Research in Geodynamics and Earth Tides : An account of the 18th Geodynamics and Earth Tides Symposium 2016, Trieste, Italy

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    This volume aims at conveying the rich and interdisciplinary topics discussed at the 18th Geodynamics and Earth Tides Symposium, Trieste, 2016. For seventeen times the gathering was named the Earth Tides Symposium, when giving tribute to the evolution of the observed signals, the term geodynamics was added to the title.The present volume aims at a full coverage of the Symposium by including the entire list of abstracts that were presented either as oral or poster presentation
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