8,700 research outputs found

    Differentiating patterns of violence in the family

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    The feasibility and prevalence of Reciprocal, Hierarchical and Paternal patterns of family aggression hypothesised by Dixon and Browne (2003) were explored within a sample of maltreating families. The psychological reports of 67 families referred to services for alleged child maltreatment that evidenced concurrent physical intimate partner violence and child maltreatment were investigated. Of these, 29 (43.3%) cases were characterised by hierarchical; 28 (41.8%) Reciprocal and 10 (14.9%) Paternal patterns. Significant differences in the form of child maltreatment perpetrated by mothers and fathers and parent dyads living in different patterns were found. In Hierarchical sub-patterns, fathers were significantly more likely to have been convicted for a violent and/or sexual offence than mothers and were significantly less likely to be biologically related to the child. The findings demonstrate the existence of the different patterns in a sample of families involved in the Child Care Protection process in England and Wales, supporting the utility of a holistic approach to understanding aggression in the family

    On the well-posedness of the stochastic Allen-Cahn equation in two dimensions

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    White noise-driven nonlinear stochastic partial differential equations (SPDEs) of parabolic type are frequently used to model physical and biological systems in space dimensions d = 1,2,3. Whereas existence and uniqueness of weak solutions to these equations are well established in one dimension, the situation is different for d \geq 2. Despite their popularity in the applied sciences, higher dimensional versions of these SPDE models are generally assumed to be ill-posed by the mathematics community. We study this discrepancy on the specific example of the two dimensional Allen-Cahn equation driven by additive white noise. Since it is unclear how to define the notion of a weak solution to this equation, we regularize the noise and introduce a family of approximations. Based on heuristic arguments and numerical experiments, we conjecture that these approximations exhibit divergent behavior in the continuum limit. The results strongly suggest that a series of published numerical studies are problematic: shrinking the mesh size in these simulations does not lead to the recovery of a physically meaningful limit.Comment: 21 pages, 4 figures; accepted by Journal of Computational Physics (Dec 2011

    Protein farnesyltransferase and protein prenylation in Plasmodium falciparum

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    Comparison of the malaria parasite and mammalian protein prenyltransferases and their cellular substrates is important for establishing this enzyme as a target for developing antimalarial agents. Nineteen heptapeptides differing only in their carboxyl-terminal amino acid were tested as alternative substrates of partially purified Plasmodium falciparum protein farnesyltransferase. Only NRSCAIM and NRSCAIQ serve as substrates, with NRSCAIM being the best. Peptidomimetics, FTI-276 and GGTI-287, inhibit the transferase with IC50 values of 1 and 32 nm, respectively. Incubation of P. falciparum-infected erythrocytes with [H-3]farnesol labels 50- and 22-28-kDa proteins, whereas [H-3]geranylgeraniol labels only 22-28-kDa proteins. The 50-kDa protein is shown to be farnesylated, whereas the 22-28-kDa proteins are geranylgeranylated, irrespective of the labeling prenol. Protein labeling is inhibited more than 50% by either 5 mum FTI-277 or GGTI-298. The same concentration of inhibitors also inhibits parasite growth from the ring stage by 50%, decreases expression of prenylated proteins as measured with prenyl-specific antibody, and inhibits parasite differentiation beyond the trophozoite stage. Furthermore, differentiation specific prenylation of P. falciparum proteins is demonstrated. Protein labeling is detected predominantly during the trophozoite to schizont and schizont to ring transitions. These results demonstrate unique properties of protein prenylation in P. falciparum: a limited specificity of the farnesyltransferase for peptide substrates compared with mammalian enzymes, the ability to use farnesol to label both farnesyl and geranylgeranyl moieties on proteins, differentiation specific protein prenylation, and the ability of peptidomimetic prenyltransferase inhibitors to block parasite differentiation

    Acute ischemic preconditioning does not influence high-intensity intermittent exercise performance

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    This study evaluated the acute effect of ischemic preconditioning (IPC) on a high-intensity intermittent exercise performance and physiological indicators in amateur soccer players. Thirteen players (21.5 ± 2 yrs) attended three trials separated by 3–5 days in a counterbalanced randomized cross-over design: IPC (4 × 5-min occlusion 220 mmHg/reperfusion 0 mmHg) in each thigh; SHAM (similar to the IPC protocol but “occlusion” at 20 mmHg) and control (seated during the same time of IPC). After 6-min of each trial (IPC, SHAM or control), the players performed the YoYo Intermittent Endurance Test level 2 (YoYoIE2). The distance covered in the YoYoIE2 (IPC 867 ± 205 m; SHAM 873 ± 212 m; control 921 ± 206 m) was not different among trials (p = 0.10), furthermore, lactate concentration and rate of perceived exertion did not differ (P > 0.05) among protocols. There were also no significant differences in either mean heart rate (HR) or peak HR (p > 0.05) for both IPC and SHAM compared to control. Therefore, we conclude that acute IPC does not influence high-intensity intermittent exercise performance in amateur soccer players and that rate of perceived exertion, heart rate and lactate do not differ between the intervention IPC, SHAM and control

    The plight of the sense-making ape

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    This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception

    Is evolution faster at ecotones? A test using rates and tempo of diet transitions in Neotropical Sigmodontinae (Rodentia, Cricetidae)

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    We evaluated whether evolution is faster at ecotones as niche shifts may be needed to persist under unstable environment. We mapped diet evolution along the evolutionary history of 350 sigmodontine species. Mapping was used in three new tipbased metrics of trait evolution – Transition Rates, Stasis Time, and Last Transition Time – which were spatialized at the assemblage level (aTR, aST, aTL). Assemblages were obtained by superimposing range maps on points located at core and ecotone of the 93 South American ecoregions. Using Linear Mixed Models, we tested whether ecotones have species with more changes from the ancestral diet (higher aTR), have maintained the current diet for a shorter time (lower aST), and have more recent transitions to the current diet (lower aLT) than cores. We found lower aTR, and higher aST and aLT at ecotones than at cores. Although ecotones are more heterogeneous, both environmentally and in relation to selection pressures they exert on organisms, ecotone species change little from the ancestral diet as generalist habits are necessary toward feeding in ephemeral environments. The need to incorporate phylogenetic uncertainty in tip-based metrics was evident from large uncertainty detected. Our study integrates ecology and evolution by analyzing how fast trait evolution is across space

    Cross modal perception of body size in domestic dogs (Canis familiaris)

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    While the perception of size-related acoustic variation in animal vocalisations is well documented, little attention has been given to how this information might be integrated with corresponding visual information. Using a cross-modal design, we tested the ability of domestic dogs to match growls resynthesised to be typical of either a large or a small dog to size- matched models. Subjects looked at the size-matched model significantly more often and for a significantly longer duration than at the incorrect model, showing that they have the ability to relate information about body size from the acoustic domain to the appropriate visual category. Our study suggests that the perceptual and cognitive mechanisms at the basis of size assessment in mammals have a multisensory nature, and calls for further investigations of the multimodal processing of size information across animal species

    Fusion of green fluorescent protein to the C-terminus of granulysin alters its intracellular localization in comparison to the native molecule

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    The engineering of green fluorescent protein (GFP) fusion constructs in order to visibly tag a protein of interest has become a commonly used cell biology technique. Although caveats to this approach are obvious, literature reports in which the chimeric molecule behaves differently than the native molecule are scant. This brief report describes one such case. Granulysin, a small lytic and antimicrobial protein produced by cytotoxic lymphocytes, traffics to the regulated secretory system and is subsequently released from cells upon proper stimulus. In an attempt to elucidate mechanisms by which it accumulates in and is released from cytolytic granules, GFP was fused to the C-terminus of granulysin and expressed in an NK cell line. A control construct expressing the native protein was similarly expressed. The data demonstrate that, while the fusion protein is expressed and secreted, its subcellular localization is altered in comparison to native granulysin. Thus, the addition of GFP to the C-terminus of granulysin obscures the signal(s) that cytotoxic lymphocytes use to sort it to the regulated secretory pathway despite its normal biosynthesis and secretion. This example is offered as a cautionary account for other researchers who contemplate using this technology

    Mechanisms Underlying the Delayed Activation of the Cap1 Transcription Factor in Candida albicans following Combinatorial Oxidative and Cationic Stress Important for Phagocytic Potency

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    ACKNOWLEDGMENTS We are grateful to Brian Morgan and Elizabeth Veal for insightful discussions, Mélanie Ikeh for experimental assistance, and Scott Moye-Rowley (University of Iowa) for the gift of the anti-Cap1 antibody. This work was funded by the NIHR Newcastle Biomedical Research Centre (I.K.), a BBSRC DTG studentship (M.J.P.), the Wellcome Trust (grants 089930 and 097377 to J.Q. and 080088 and 097377 to A.J.P.B.), the BBSRC (grants BB/K016393/1 to J.Q. and BB/F00513X/1 and BB/K017365/1 to A.J.P.B.), the European Research Council (STRIFE Advanced grant ERC-2009-AdG-249793 to A.J.P.B.), the ANR (grant CANDIHUB, ANR-14-CE14-0018-01, to C.D.), and the French Government’s Investissement d’Avenir program (grant IBEID, ANR-10-LABX-62-IBEID, to C.D.). FUNDING INFORMATION This work, including the efforts of Alistair J.P. Brown, was funded by Wellcome Trust (097377 and 080088). This work, including the efforts of Janet Quinn, was funded by Wellcome Trust (097377 and 089930). This work, including the efforts of Alistair J.P. Brown, was funded by EC European Research Council (ERC) (ERC-2009-AdG-249793). This work, including the efforts of Alistair J.P. Brown, was funded by Biotechnology and Biological Sciences Research Council (BBSRC) (BB/F00513X/1 and BB/K017365/1). This work, including the efforts of Janet Quinn, was funded by Biotechnology and Biological Sciences Research Council (BBSRC) (BB/K016393/1). This work, including the efforts of Christophe d’Enfert, was funded by Agence Nationale de la Recherche (ANR) (ANR-14-CE14-0018-01 and ANR-10-LABX-62-IBEID).Peer reviewedPublisher PD
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