117 research outputs found

    Quantitatively measuring the influence of helium in plasma-exposed tungsten

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    AbstractTungsten samples are exposed to 3He plasma to quantify their helium retention behavior. The retention saturates quickly with helium fluence and increases only slightly from 4.3×1019He/m2 at 773K, to 7.5×1019He/m2 at 973K. The helium content increases dramatically to 6.8×1020He/m2 when fuzz is formed on the surface of a sample exposed at 1173K, but the majority of the retained helium (5.1×1020He/m2) is found to reside below the layer of fuzz tendrils. Additional tungsten samples were exposed to either simultaneous, or sequential, D/He plasma, followed by TDS. Measurements show the majority of the D retained during simultaneous exposures is located in the near surface region of helium nano-bubbles. No deuterium was detected in any of the samples after the heating to 1273K, but 67% of the helium was released from simultaneously exposed samples, and only 23% of the helium was released from the sequentially exposed samples

    Robust stationary entanglement of two coupled qubits in independent environments

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    The dissipative dynamics of two interacting qubits coupled to independent reservoirs at nonzero temperatures is investigated, paying special attention to the entanglement evolution. The counter-rotating terms in the qubit-qubit interaction give rise to stationary entanglement, traceable back to the ground state structure. The robustness of this entanglement against thermal noise is thoroughly analyzed, establishing that it can be detected at reasonable experimental temperatures. Some effects linked to a possible reservoir asymmetry are brought to light.Comment: 8 pages, 6 figures; version accepted for publication on Eur. Phys. J.

    Acute hepatitis C infection after sexual exposure

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    A case is described of a woman with acute hepatitis C infection whose partner had chronic hepatitis C infection and where heterosexual contact was the only major risk factor. Infection of both partners was confirmed serologically and by the finding of virus RNA by reverse transcription and polymerase chain reaction amplification. Nucleotide sequence analysis of the NS5 region (RNA polymerase) was used to show that both partners were infected with virus of the same genotype (1a). The nucleotide sequence of virus RNA found in the female patient is closest to variants cocirculating in the male contact, consistent with transmission having occurred between the two

    El Apego Va a Juicio: Problemas de Custodia y Protección Infantil1

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    Attachment theory and research are drawn upon in many applied settings, including family courts, but misunderstandings are widespread and sometimes result in misapplications. The aim of this consensus statement is, therefore, to enhance understanding, counter misinformation, and steer family-court utilisation of attachment theory in a supportive, evidence-based direction, especially with regard to child protection and child custody decision-making. This article is divided into two parts. In the first part, we address problems related to the use of attachment theory and research in family courts, and discuss reasons for these problems. To this end, we examine family court applications of attachment theory in the current context of the best-interest-of-the-child standard, discuss misunderstandings regarding attachment theory, and identify factors that have hindered accurate implementation. In the second part, we provide recommendations for the application of attachment theory and research. To this end, we set out three attachment principles: the child’s need for familiar, non-abusive caregivers; the value of continuity of good-enough care; and the benefits of networks of attachment relationships. We also discuss the suitability of assessments of attachment quality and caregiving behaviour to inform family court decision-making. We conclude that assessments of caregiver behaviour should take center stage. Although there is dissensus among us regarding the use of assessments of attachment quality to inform child custody and child-protection decisions, such assessments are currently most suitable for targeting and directing supportive interventions. Finally, we provide directions to guide future interdisciplinary research collaboration

    Wnt signalling and cancer stem cells

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    [Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e Innovación; SAF2008-0060
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