6,569 research outputs found
Spatial Entanglement From Off-Diagonal Long Range Order in a BEC
We investigate spatial entanglement - particle-number entanglement between
regions of space - in an ideal Bosonic gas. We quantify the amount spatial
entanglement around the transition temperature for condensation by probing the
gas with two localised two-level systems. We show that spatial entanglement in
the gas is directly related to filling of the ground state energy level and
therefore to the off-diagonal long-range order of the system and the onset of
condensation.Comment: 7 pages, 3 figures. Extended from 4 to 7 pages. More detailed
derivations of key formula. Extended introduction and background. Results
remain unchange
Magnetic Hole Formation from the Perspective of Inverse Scattering Theory
The dynamics of oblique, weakly dispersive nonlinear Alfven waves in the presence of weak resistive damping are investigated numerically through an extension of the derivative nonlinear Schrodinger (DNLS) equation. It is observed numerically that the nonlinear dynamics are organized around the dynamics and allowed interactions of the underlying DNLS soliton families. There are three types of oblique Alfven solitons: the compressive two-parameter soliton and one-parameter bright soliton along with the rare factive one-parameter dark soliton. The damping of either of these compressive solitons is accompanied by the formation of one or more dark solitons. The implication of these processes is that any initial wave profile containing solitons in its Inverse Scattering Transformation representation, in the presence of weak resistive damping, will result in a leading train of dark solitons. These dark soliton shave been identified with magnetic holes, and the results described above are discussed in the context of magnetic hole observations and theory
Equilibrium and Disorder-induced behavior in Quantum Light-Matter Systems
We analyze equilibrium properties of coupled-doped cavities described by the
Jaynes-Cummings- Hubbard Hamiltonian. In particular, we characterize the
entanglement of the system in relation to the insulating-superfluid phase
transition. We point out the existence of a crossover inside the superfluid
phase of the system when the excitations change from polaritonic to purely
photonic. Using an ensemble statistical approach for small systems and
stochastic-mean-field theory for large systems we analyze static disorder of
the characteristic parameters of the system and explore the ground state
induced statistics. We report on a variety of glassy phases deriving from the
hybrid statistics of the system. On-site strong disorder induces insulating
behavior through two different mechanisms. For disorder in the light-matter
detuning, low energy cavities dominate the statistics allowing the excitations
to localize and bunch in such cavities. In the case of disorder in the light-
matter coupling, sites with strong coupling between light and matter become
very significant, which enhances the Mott-like insulating behavior. Inter-site
(hopping) disorder induces fluidity and the dominant sites are strongly coupled
to each other.Comment: about 10 pages, 12 figure
Microfabricated silicon biosensors for microphysiometry
Microphysiometers are biosensor devices that measure the metabolic rate of living cells by detecting the rate of extracellular acidification caused by a small number of cells. The cells are entrapped in a microvolume chamber, whose bottom surface is a silicon sensor chip. In a further miniaturization step, we have recently fabricated multichannel flow-through chips that will allow greater throughput and multiplicity. Microphysiometer technology can be applied to the detection of microorganisms. We describe the sensitive detection of bacteria and yeast. Further applications of microphysiometry to the characterization of microorganisms can be anticipated
Non-Violent Resistance parent training and adolescent substance misuse
Adolescent substance misuse is increasingly being viewed as a systemic problem and several studies have shown the benefit of increased parental involvement. This article describes the evaluation of a ten-week Non-Violent Resistance (NVR) group parent training programme delivered within a Young People’s Specialist Substance Misuse Treatment Service. Eighteen participants completed questionnaires before and after the programme, and at follow-up. Eight participants also took part in semi-structured interviews. Parents reported experiencing the programme as unique and helpful, and highlighted some challenges. Measures of parental self-efficacy and goal-based outcomes showed significant improvement at the end of the programme, and improvement in parental self-efficacy remained significant at follow-up. This evaluation provides preliminary evidence that NVR parent training may be a useful intervention in this context. However, the generalisability of the data is limited and further research is needed. Practitioner points: Non-Violent Resistance parent training helps parents resist their child’s behaviour, manage their own emotional reactions, and recruit supporters from their wider network Qualitative data suggests that parents who have attended this programme experience additional benefits to those found in qualitative evaluations of other parenting interventions A group training programme delivered within a Young People’s Specialist Substance Misuse Treatment Service improves parents’ self-efficacy and helps them achieve their goals for their children.</p
Non-Violent Resistance parent training and adolescent substance misuse
Adolescent substance misuse is increasingly being viewed as a systemic problem and several studies have shown the benefit of increased parental involvement. This article describes the evaluation of a ten-week Non-Violent Resistance (NVR) group parent training programme delivered within a Young People’s Specialist Substance Misuse Treatment Service. Eighteen participants completed questionnaires before and after the programme, and at follow-up. Eight participants also took part in semi-structured interviews. Parents reported experiencing the programme as unique and helpful, and highlighted some challenges. Measures of parental self-efficacy and goal-based outcomes showed significant improvement at the end of the programme, and improvement in parental self-efficacy remained significant at follow-up. This evaluation provides preliminary evidence that NVR parent training may be a useful intervention in this context. However, the generalisability of the data is limited and further research is needed. Practitioner points: Non-Violent Resistance parent training helps parents resist their child’s behaviour, manage their own emotional reactions, and recruit supporters from their wider network Qualitative data suggests that parents who have attended this programme experience additional benefits to those found in qualitative evaluations of other parenting interventions A group training programme delivered within a Young People’s Specialist Substance Misuse Treatment Service improves parents’ self-efficacy and helps them achieve their goals for their children.</p
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Inducible interleukin-1 gene expression in human vascular smooth muscle cells.
Interleukin-1 (IL-1) mediates many components of generalized host response to injury and may also contribute to local vascular pathology during immune or inflammatory responses. Because altered function of smooth muscle cells (SMC) accompanies certain vascular diseases, we tested whether SMC themselves might produce this hormone. Unstimulated SMC contain little or no IL-1 mRNA. However, exposure to bacterial endotoxin caused accumulation of IL-1 mRNA in SMC cultured from human vessels. Endotoxin maximally increased IL-1 beta mRNA in SMC after 4-6 h. The lowest effective concentration of endotoxin was 10 pg/ml. 10 ng/ml produced maximal increases in IL-1 beta mRNA. Interleukin-1 alpha mRNA was detected when SMC were incubated with endotoxin under "superinduction" conditions with cycloheximide. Endotoxin-stimulated SMC also released biologically functional IL-1, measured as thymocyte costimulation activity inhibitable by anti-IL-1 antibody. Thus, human SMC can express IL-1 beta and IL-1 alpha genes, or very similar ones, and secrete biologically active product in response to a pathological stimulus. Endogenous local production of this inflammatory mediator by the blood vessel wall's major cell type could play an important early role in the pathogenesis of vasculitis and arteriosclerosis
Coping Behaviour as an Adaptation to Stress: Post-Disturbance Preening in Colonial Seabirds
In humans, coping behaviour is an action taken to soothe oneself during or after a stressful or threatening situation. Some human behaviours with physiological functions also serve as coping behaviours, for example, comfort sucking in infants and comfort eating in adults. In birds, the behaviour of preening, which has important physiological functions, has been postulated to soothe individuals after stressful situations. We combine two existing modelling approaches – logistic regression and Darwinian dynamics – to explore theoretically how a behaviour with crucial physiological function might evolve into a coping behaviour. We apply the method to preening in colonial seabirds to investigate whether and how preening might be co-opted as a coping behaviour in the presence of predators. We conduct an in-depth study of the environmental correlates of preening in a large gull colony in Washington, USA, and we perform an independent field test for comfort preening by computing the change in frequency of preening in gulls that were alerted to a predator, but did not flee
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Interferon-gamma deficiency prevents coronary arteriosclerosis but not myocardial rejection in transplanted mouse hearts
We have hypothesized that T cell cytokines participate in the pathogenesis of graft arterial disease (GAD). This study tested the consequences of IFN-gamma deficiency on arterial and parenchymal pathology in murine cardiac allografts. Hearts from C-H-2(bm12)KhEg (bm12, H-2(bm12)) were transplanted into C57/B6 (B6, H-2(b)), wild-type, or B6 IFN-gamma-deficient (GKO) recipients after immunosuppression by treatment with anti-CD4 and anti-CD8 mAbs. In wild-type recipients, myocardial rejection peaked at 4 wk, (grade 2. 1+/-0.3 out of 4, mean+/-SEM, n = 9), and by 8-12 wk evolved coronary arteriopathy. At 12 wk, the GAD score was 1.4+/-0.3, and the parenchymal rejection grade was 1.2+/-0.3 (n = 8). In GKO recipients of bm12 allografts, myocardial rejection persisted at 12 wk (grade 2.5+/-0.3, n = 6), but no GAD developed (score: 0.0+/-0.0, n = 6, P < 0.01 vs. wild-type). Mice treated with anti-IFN-gamma mAbs showed similar results. Isografts generally showed no arterial changes. In wild-type recipients, arterial and parenchymal cells showed increased MHC class II molecules, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 compared to normal or isografted hearts. The allografts in GKO recipients showed attenuated expression of these molecules (n = 6). Thus, development of GAD, but not parenchymal rejection, requires IFN-gamma. Reduced expression of MHC antigens and leukocyte adhesion molecules may contribute to the lack of coronary arteriopathy in hearts allografted into GKO mice
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