1,344 research outputs found

    Optical vault: reconfigurable bottle beam by conically refracted light

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    We employ conical refraction of light in a biaxial crystal to create an optical bottle for trapping and manipulation of particles. We show that by just varying the polarization of the input light the bottle can be opened and closed at will. We experimentally demonstrate stable photophoretic trapping and controllable loading and unloading of light absorbing particles in the trap.Comment: 4 pages, 5 figure

    Pre- and post- prandial appetite hormone levels in normal weight and severely obese women

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    <p>Abstract</p> <p>Background</p> <p>Appetite is affected by many factors including the hormones leptin, ghrelin and adiponectin. Ghrelin stimulates hunger, leptin promotes satiety, and adiponectin affects insulin response. This study was designed to test whether the pre- and postprandial response of key appetite hormones differs in normal weight (NW) and severely obese (SO) women.</p> <p>Methods</p> <p>Twenty three women ages 25–50 were recruited for this study including 10 NW (BMI = 23.1 ± 1.3 kg/m<sup>2</sup>) and 13 SO (BMI = 44.5 ± 7.1 kg/m<sup>2</sup>). The study was conducted in a hospital-based clinical research centre. Following a 12-hour fast, participants had a baseline blood draw, consumed a moderately high carbohydrate meal (60% carbohydrate, 20% protein, 20% fat) based on body weight. Postprandially, participants had six blood samples drawn at 0, 15, 30, 60, 90, and 120 minutes. Primary measures included pre- and post-prandial total ghrelin, leptin, adiponectin and insulin. A repeated measures general linear model was used to evaluate the hormone changes by group and time (significance p ≤ 0.05).</p> <p>Results</p> <p>There were significant differences between the NW and the SO for all hormones in the preprandial fasting state. The postprandial responses between the SO versus NW revealed: higher leptin (p < 0.0001), lower adiponectin (p = 0.04), trend for lower ghrelin (p = 0.06) and insulin was not different (p = 0.26). Postprandial responses over time between the SO versus NW: higher leptin (p < 0.001), lower ghrelin and adiponectin (p = 0.004, p = 0.015, respectively), and trend for higher insulin (p = 0.06).</p> <p>Conclusion</p> <p>This study indicates that significant differences in both pre- and selected post- prandial levels of leptin, ghrelin, adiponectin and insulin exist between NW and SO women. Improving our understanding of the biochemical mechanisms accounting for these differences in appetite hormones among individuals with varying body size and adiposity should aid in the development of future therapies to prevent and treat obesity.</p

    Contribution of the d-Serine-Dependent Pathway to the Cellular Mechanisms Underlying Cognitive Aging

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    An association between age-related memory impairments and changes in functional plasticity in the aging brain has been under intense study within the last decade. In this article, we show that an impaired activation of the strychnine-insensitive glycine site of N-methyl-d-aspartate receptors (NMDA-R) by its agonist d-serine contributes to deficits of synaptic plasticity in the hippocampus of memory-impaired aged rats. Supplementation with exogenous d-serine prevents the age-related deficits of isolated NMDA-R-dependent synaptic potentials as well as those of theta-burst-induced long-term potentiation and synaptic depotentiation. Endogenous levels of d-serine are reduced in the hippocampus with aging, that correlates with a weaker expression of serine racemase synthesizing the amino acid. On the contrary, the affinity of d-serine binding to NMDA-R is not affected by aging. These results point to a critical role for the d-serine-dependent pathway in the functional alterations of the brain underlying memory impairment and provide key information in the search for new therapeutic strategies for the treatment of memory deficits in the elderly

    Mothers of Soldiers in Wartime: A National News Narrative

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    National news media represent mothers of US combat soldiers in the Iraq War as archetypal good mothers, that is, mothers who continue their maternal work even after their children are deployed. However, not all mothers are depicted as the archetypal patriotic mother, i.e., a good mother who is also stoic and silent about the war and her child\u27s role in it. Mothers of soldiers are portrayed as good mothers who sometimes also voice their attitudes about the war effort. The maternal attitudes ranged from complete support for the war to opposition to the war but support for the soldiers. The findings suggest a picture of wartime motherhood that is more nuanced than the historical image of the patriotic mother suggests

    STLV-1 co-infection is correlated with an increased SFV proviral load in the peripheral blood of SFV/STLV-1 naturally infected non-human primates

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    Simian T-Leukemia Virus type 1 and Simian Foamy Virus infect non-human primates. While STLV-1, as HTLV-1, causes Adult T-cell Leukemia/lymphoma, SFV infection is asymptomatic. Both retroviruses can be transmitted from NHPs to humans through bites that allow contact between infected saliva and recipient blood. Because both viruses infect CD4+ T-cells, they might interfere with each other replication, and this might impact viral transmission. Impact of STLV-1 co-infection on SFV replication was analyzed in 18 SFV-positive/STLV-1-negative and 18 naturally SFV/STLV-1 co-infected Papio anubis. Even if 9 animals were found STLV-1-positive in saliva, STLV-1 PVL was much higher in the blood. SFV proviruses were detected in the saliva of all animals. Interestingly, SFV proviral load was much higher in the blood of STLV-1/SFV co-infected animals, compared to STLV-1-negative animals. Given that soluble Tax protein can enter uninfected cells, we tested its effect on foamy virus promoter and we show that Tax protein can transactivate the foamy LTR. This demonstrates that true STLV-1 co-infection or Tax only has an impact on SFV replication and may influence the ability of the virus to be zoonotically transmitted as well as its ability to promote hematological abnormalities

    A qualitative study of goodbye letters in prison therapy: Imprisoned women who self-harm.

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    Background. Self-harm rates amongst imprisoned women in the UK are extremely high and there are limited psychological therapies available to support them in prison. This paper presents women's subjective accounts of receiving 'goodbye letters' at the end of brief Psychodynamic Interpersonal Therapy (PIT) and how these letters positively impacted on their incidents of self-harm. Aims. This study presents the accounts of 13 imprisoned women who self-harmed and received letters following completion of a minimum of 4 sessions of brief PIT in prison. Methods. A semi-structured interview covered several aspects of their experience, which included details of self-harm since completing brief therapy, usage of goodbye letter and its impact. The interviews were analysed using thematic analysis. Results. Three themes emerged from the analysis: connecting with the therapist: receiving the letter; connecting to self: understanding and awareness; and connecting to others: sharing the goodbye letter. Conclusions. Findings are discussed and show the positive impact the letters had for the women following therapy. The preliminary impressions suggest that letters may be a helpful tool enhancing the benefits of brief PIT therapy with imprisoned women who self-harm
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