1,434 research outputs found

    Programming the brain: common outcomes and gaps in knowledge from animal studies of IUGR

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    Available online 7 June 2016Abstract not availableDamien S. Hunter, Susan J. Hazel, Karen L. Kinda, Julie A. Owens, Julia B. Pitcher, Kathryn L. Gatfor

    数値地図データセットからの情報抽出および汎用地図ツールへの転用

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    We followed the abundance and distribution of ammonia-oxidizing Archaea (AOA) in the North Sea from April 2003 to February 2005 and from October 2007 to March 2008 by quantification of archaeal genes and core glycerol dibiphytanyl glycerol tetraether (GDGT) membrane lipids in suspended particulate matter, to determine whether their abundance in the North Sea is seasonal. GDGT and gene abundance increased during winters and was low during the summer. Crenarchaeol-a GDGT specific to AOA-was a major fraction of the GDGTs and varied in concert with AOA gene abundance, indicating that AOA are the predominant source of crenarchaeol. The presence of crenarchaeol-based intact polar lipids (IPLs) confirmed that the GDGTs recovered were derived from living AOA, as IPLs are rapidly degraded upon cell senescence and thus their occurrence represents living biomass more robustly than their fossil (i.e., core GDGT) counterparts. Dark incubations of North Sea water sampled during the 2007-2008 seasonal cycle with C-13-labeled bicarbonate revealed incorporation of inorganic carbon into IPL-derived GDGTs, directly showing autotrophic production of Thaumarchaeota biomass during the winter. Inhibition of C-13 uptake by nitrification inhibitors confirmed that ammonia oxidation was the main source of energy for carbon fixation. Winter blooms of planktonic AOA in the North Sea were recurrent and predictable, occurring annually between November and February, emphasizing the potential importance of AOA in nitrogen cycling in the North Sea

    Geographic variation in sperm traits reflects predation risk and natural rates of multiple paternity in the guppy

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    Guppies (Poecilia reticulata) are models for understanding the interplay between natural and sexual selection. In particular, predation has been implicated as a major force affecting female sexual preferences, male mating tactics and the level of sperm competition. When predation is high, females typically reduce their preferences for showy males and engage more in antipredator behaviours, whereas males exploit these changes by switching from sexual displays to forced matings. These patterns are thought to account for the relatively high levels of multiple paternity in high-predation populations compared to low-predation populations. Here, we assess the possible evolutionary consequences of these patterns by asking whether variation in sperm traits reflect differences in predation intensity among four pairs of Trinidadian populations: four that experience relatively low levels of predation from a gape-limited predator and four that experience relatively high levels of predation from a variety of piscivores. We found that males in high-predation populations had faster swimming sperm with longer midpieces compared to males in low-predation populations. However, we found no differences among males in high- and low-predation populations with respect to sperm number, sperm head length, flagellum length and total sperm length

    Contrasting Pressure Effects in Sr2VFeAsO3 and Sr2ScFePO3

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    We report the resistivity measurements under pressure of two Fe-based superconductors with a thick perovskite oxide layer, Sr2VFeAsO3 and Sr2ScFePO3. The superconducting transition temperature Tc of Sr2VFeAsO3 markedly increases with increasing pressure. Its onset value, which was Tc{onset}=36.4 K at ambient pressure, increases to Tc{onset}=46.0 K at ~4 GPa, ensuring the potential of the "21113" system as a high-Tc material. However, the superconductivity of Sr2ScFePO3 is strongly suppressed under pressure. The Tc{onset} of ~16 K decreases to ~5 K at ~4 GPa, and the zero-resistance state is almost lost. We discuss the factor that induces this contrasting pressure effect.Comment: 5 pages, 4 figures, to be published in J. Phys. Soc. Jpn. No.12 (2009

    Pair-Hopping Mechanism for Layered Superconductors

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    We propose a possible charge fluctuation effect expected in layered superconducting materials. In the multireference density functional theory, relevant fluctuation channels for the Josephson coupling between superconducting layers include the interlayer pair hopping derived from the Coulomb repulsion. When interlayer single-electron tunneling processes are irrelevant in the Kohn-Sham electronic band structure calculation, the two-body effective interactions stabilize a superconducting phase. This state is also regarded as a valence-bond solid in a bulk electronic state. The hidden order parameters coexist with the superconducting order parameter when the charging effect of a layer is comparable to the pair hopping. Relevant materials structures favorable for the pair-hopping mechanism are discussed.Comment: 24 pages, 2 figures, to be published in J. Phys. Soc. Jpn. (2009

    Anion height dependence of Tc for the Fe-based superconductor

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    We have established a plot of the anion height dependence of Tc for the typical Fe-based superconductors. The plot appeared a symmetric curve with a peak around 1.38 A. Both data at ambient pressure and under high pressure obeyed the unique curve. This plot will be one of the key strategies for both understanding the mechanism of Fe-based superconductivity and search for the new Fe-based superconductors with higher Tc.Comment: 13 pages, 4 figure

    Do I turn left or right? Effects of sex, age, experience and exit route on maze test performance in sheep

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    Abstract not availableDamien S. Hunter, Susan J. Hazel, Karen L. Kind, Hong Liu, Danila Marini, Julie A. Owens, Julia B. Pitcher, Kathryn L. Gatfor

    On our own terms : the working conditions of internet-based sex workers in the UK

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    The sex industry is increasingly operated through online technologies, whether this is selling services online through webcam or advertising, marketing or organising sex work through the Internet and digital technologies. Using data from a survey of 240 internet-based sex workers (members of the National Ugly Mug reporting scheme in the UK), we discuss the working conditions of this type of work. We look at the basic working patterns, trajectories and everyday experiences of doing sex work via an online medium and the impact this has on the lives of sex workers. For instance, we look at levels of control individuals have over their working conditions, prices, clientele and services sold, and discuss how this is mediated online and placed in relation to job satisfaction. The second key finding is the experience of different forms of crimes individuals are exposed to such as harassment and blackmail via the new technologies. We explore the relationship internet-based sex workers have with the police and discuss how current laws in the UK have detrimental effects in terms of safety and access to justice. These findings are placed in the context of the changing landscape of sex markets as the digital turn determines the nature of the majority of commercial sex encounters. These findings contribute significantly to the populist coercion/choice political debates by demonstrating levels and types of agency and autonomy experienced by some sex workers despite working in a criminalized, precarious and sometimes dangerous context
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