19 research outputs found

    Neuroinflammatory TNFα Impairs Memory via Astrocyte Signaling.

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    The occurrence of cognitive disturbances upon CNS inflammation or infection has been correlated with increased levels of the cytokine tumor necrosis factor-α (TNFα). To date, however, no specific mechanism via which this cytokine could alter cognitive circuits has been demonstrated. Here, we show that local increase of TNFα in the hippocampal dentate gyrus activates astrocyte TNF receptor type 1 (TNFR1), which in turn triggers an astrocyte-neuron signaling cascade that results in persistent functional modification of hippocampal excitatory synapses. Astrocytic TNFR1 signaling is necessary for the hippocampal synaptic alteration and contextual learning-memory impairment observed in experimental autoimmune encephalitis (EAE), an animal model of multiple sclerosis (MS). This process may contribute to the pathogenesis of cognitive disturbances in MS, as well as in other CNS conditions accompanied by inflammatory states or infections

    Modern trends of the development of excursion tourism in Belarus

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    экскурсионный туризм, экскурсионные маршруты, туристская индустрия, инновации в экскурсионном туризме = excursion tourism, excursion routes, tourism industry, innovations in excursion tourism.Статья посвящена анализу современного состояния и особенностей развития экскурсионного туризма в Беларуси. Выявлены основные тенденции развития и инновационной деятельности в сфере экскурсионного туризма.The article is devoted to the analysis of the current state and the most important features in the development of the excursion tourism in Belarus. The basic trends and areas of innovation in the field of excursion tourism were identified

    Construction elasticities and land availability: a two-stage least-squares model of housing supply using the variable elasticity approach

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    This paper uses data at English local authority district level to construct a simultaneous equation model of housing construction that compares elasticit ies of supply between two cross-sec tional periodsÐ 1988 (boom) and 1992 (slump)Ð using the variable elasticit y approach. Econometric issues raised by earlier supply studies are discussed and tested for. The paper also discusses the rationale for, and tests the existen ce of, a backward-bending supply relation ship, and ® nds that supply is concave in both periods, and `bends backwards’ during the boom. Evidence of a structural break between boom and bust is found, producing average price elasticit ies of supply noticeab ly smaller in the boom (0.58) than in the slump (1.03), with considerable variatio n across disticts. Land supply elasticit ies are found to be more stable over time, and marginally greater in the boom (0.75) than in the slump (0.71). The paper also calculates second partial derivativ es based on the whole demand± supply system to obtain estimates of the impact of land release on new house prices

    Heterogeneity in genetic variation and energy sink relationships for residual feed intake across research stations and countries

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    Our long-term objective is to develop breeding strategies for improving feed efficiency in dairy cattle. In this study, phenotypic data were pooled across multiple research stations to facilitate investigation of the genetic and nongenetic components of feed efficiency in Holstein cattle. Specifically, the heritability of residual feed intake (RFI) was estimated and heterogeneous relationships between RFI and traits relating to energy utilization were characterized across research stations. Milk, fat, protein, and lactose production converted to megacalories (milk energy; MilkE), dry matter intakes (DMI), and body weights (BW) were collected on 6,824 lactations from 4,893 Holstein cows from research stations in Scotland, the Netherlands, and the United States. Weekly DMI, recorded between 50 to 200 d in milk, was fitted as a linear function of MilkE, BW0.75, and change in BW (¿BW), along with parity, a fifth-order polynomial on days in milk (DIM), and the interaction between this polynomial and parity in a first-stage model. The residuals from this analysis were considered to be a phenotypic measure of RFI. Estimated partial regression coefficients of DMI on MilkE and on BW0.75 ranged from 0.29 to 0.47 kg/Mcal for MilkE across research stations, whereas estimated partial regression coefficients on BW0.75 ranged from 0.06 to 0.16 kg/kg0.75. Estimated partial regression coefficients on ¿BW ranged from 0.06 to 0.39 across stations. Heritabilities for country-specific RFI were based on fitting second-stage random regression models and ranged from 0.06 to 0.24 depending on DIM. The overall heritability estimate across all research stations and all DIM was 0.15±0.02, whereas an alternative analysis based on combining the first- and second-stage model as 1 model led to an overall heritability estimate of 0.18±0.02. Hence future genomic selection programs on feed efficiency appear to be promising; nevertheless, care should be taken to allow for potentially heterogeneous variance components and partial relationships between DMI and other energy sink traits across environments when determining RFI
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