165 research outputs found

    Persistence of magnetic field driven by relativistic electrons in a plasma

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    The onset and evolution of magnetic fields in laboratory and astrophysical plasmas is determined by several mechanisms, including instabilities, dynamo effects and ultra-high energy particle flows through gas, plasma and interstellar-media. These processes are relevant over a wide range of conditions, from cosmic ray acceleration and gamma ray bursts to nuclear fusion in stars. The disparate temporal and spatial scales where each operates can be reconciled by scaling parameters that enable to recreate astrophysical conditions in the laboratory. Here we unveil a new mechanism by which the flow of ultra-energetic particles can strongly magnetize the boundary between the plasma and the non-ionized gas to magnetic fields up to 10-100 Tesla (micro Tesla in astrophysical conditions). The physics is observed from the first time-resolved large scale magnetic field measurements obtained in a laser wakefield accelerator. Particle-in-cell simulations capturing the global plasma and field dynamics over the full plasma length confirm the experimental measurements. These results open new paths for the exploration and modelling of ultra high energy particle driven magnetic field generation in the laboratory

    Wearable technology and the cardiovascular system: the future of patient assessment

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    The past decade has seen a dramatic rise in consumer technologies able to monitor a variety of cardiovascular parameters. Such devices initially recorded markers of exercise, but now include physiological and health-care focused measurements. The public are keen to adopt these devices in the belief that they are useful to identify and monitor cardiovascular disease. Clinicians are therefore often presented with health app data accompanied by a diverse range of concerns and queries. Herein, we assess whether these devices are accurate, their outputs validated, and whether they are suitable for professionals to make management decisions. We review underpinning methods and technologies and explore the evidence supporting the use of these devices as diagnostic and monitoring tools in hypertension, arrhythmia, heart failure, coronary artery disease, pulmonary hypertension, and valvular heart disease. Used correctly, they might improve health care and support research

    Effects of Attractiveness and Social Status on Dating Desire in Heterosexual Adolescents: An Experimental Study

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    The present study examined to what extent adolescent dating desire is based on attractiveness and social status of a potential short-term partner. Further, we tested whether self-perceived mate value moderated the relationship between dating desire and attractiveness of a potential partner. Data were used from a sample of 1,913 adolescents aged 13–18. Participants rated the importance of various characteristics of a potential partner and also participated in an experimental vignette study in which dating desire was measured with either low or high attractive potential partners having either a high or low social status. The results showed that boys rated attractiveness as more important than girls, while social status was rated as relatively unimportant by both sexes. In addition, in the experimental vignette study, it was found that attractiveness was the primary factor for boys’ dating desire. Only when a potential partner was attractive, social status became important for boys’ dating desire. For girls, on the other hand, it appeared that both attractiveness and social status of a potential partner were important for their dating desire. Finally, boys and girls who perceived themselves as having a high mate value showed more dating desire toward an attractive potential partner compared to adolescents who perceived themselves as having a low mate value. The present results extend previous research by showing that attractiveness of a potential partner is important to both adolescent boys and girls, but social status does not strongly affect dating desire during this particular age period

    Priming by Chemokines Restricts Lateral Mobility of the Adhesion Receptor LFA-1 and Restores Adhesion to ICAM-1 Nano-Aggregates on Human Mature Dendritic Cells

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    LFA-1 is a leukocyte specific β2 integrin that plays a major role in regulating adhesion and migration of different immune cells. Recent data suggest that LFA-1 on mature dendritic cells (mDCs) may function as a chemokine-inducible anchor during homing of DCs through the afferent lymphatics into the lymph nodes, by transiently switching its molecular conformational state. However, the role of LFA-1 mobility in this process is not yet known, despite that the importance of lateral organization and dynamics for LFA-1-mediated adhesion regulation is broadly recognized. Using single particle tracking approaches we here show that LFA-1 exhibits higher mobility on resting mDCs compared to monocytes. Lymphoid chemokine CCL21 stimulation of the LFA-1 high affinity state on mDCs, led to a significant reduction of mobility and an increase on the fraction of stationary receptors, consistent with re-activation of the receptor. Addition of soluble monomeric ICAM-1 in the presence of CCL21 did not alter the diffusion profile of LFA-1 while soluble ICAM-1 nano-aggregates in the presence of CCL21 further reduced LFA-1 mobility and readily bound to the receptor. Overall, our results emphasize the importance of LFA-1 lateral mobility across the membrane on the regulation of integrin activation and its function as adhesion receptor. Importantly, our data show that chemokines alone are not sufficient to trigger the high affinity state of the integrin based on the strict definition that affinity refers to the adhesion capacity of a single receptor to its ligand in solution. Instead our data indicate that nanoclustering of the receptor, induced by multi-ligand binding, is required to maintain stable cell adhesion once LFA-1 high affinity state is transiently triggered by inside-out signals.Peer ReviewedPostprint (published version

    Mental health consultations in a prison population: a descriptive study

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    BACKGROUND: The psychiatric morbidity among prison inmates is substantially higher than in the general population. We do, however, have insufficient knowledge about the extent of psychiatric treatment provided in our prisons. The aim of the present study was to give a comprehensive description of all non-pharmacological interventions provided by the psychiatric health services to a stratified sample of prison inmates. METHODS: Six medium/large prisons (n = 928) representing 1/3 of the Norwegian prison population and with female and preventive detention inmates over-sampled, were investigated cross-sectionally. All non-pharmacological psychiatric interventions, excluding pure correctional programs, were recorded. Those receiving interventions were investigated further and compared to the remaining prison population. RESULTS: A total of 230 of the 928 inmates (25 %) had some form of psychiatric intervention: 184 (20 %) were in individual psychotherapy, in addition 40 (4 %) received ad hoc interventions during the registration week. Group therapy was infrequent (1 %). The psychotherapies were most often of a supportive (62 %) or behavioural-cognitive (26 %) nature. Dynamic, insight-oriented psychotherapies were infrequent (8 %). Concurrent psychopharmacological treatment was prevalent (52 %). Gender and age did not correlate with psychiatric interventions, whereas prisoner category (remanded, sentenced, or preventive detention) did (p < 0.001). Most inmates had a number of defined problem areas, with substance use, depression, anxiety, and personality disorders most prevalent. Three percent of all inmates were treated for a psychotic disorder. Remand prisoners averaged 14 sessions per week per 100 inmates, while sentenced inmates and those on preventive detention averaged 22 and 25 sessions per week per 100 inmates, respectively. Five out of six psychiatric health services estimated the inmates' psychiatric therapy needs as adequately met, both overall and in the majority of individual cases. CONCLUSION: Our results pertain only to prisons with adequate primary and mental health services and effective diversion from prison of individuals with serious mental disorders. Given these important limitations, we do propose that the service estimates found may serve as a rough guideline to the minimum number of sessions a prison's psychiatric health services should be able to fulfil in order to serve the inmates psychiatric needs. The results rely on the specialist services' own estimates only. Future studies should take other important informants, including the inmates themselves, into consideration

    Implementing chlamydia screening: what do women think? A systematic review of the literature

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    BACKGROUND: Chlamydia trachomatis is a common sexually transmitted infection that can have serious consequences. It is universally agreed that screening for chlamydia infection should be offered to sexually active young women. We undertook a literature review to document the views, attitudes and opinions of women about being screened, tested and diagnosed with Chlamydia trachomatis. METHODS: Online databases (MEDLINE, Meditext, PsycINFO, Web of Science) and reference lists searched up to August 2005. Search terms: chlamydia, attitude, attitude to health, interview, qualitative, women. Eligibility criteria: about chlamydia, included women, involved interviews/surveys/focus groups, looked at women's views/opinions/attitudes, published in English. Thematic analysis identified the main and recurrent themes emerging from the literature. We compared our thematic analysis with the Theory of Planned Behaviour to provide a model that could assist in planning chlamydia screening programs. RESULTS: From 561 identified articles, 25 fulfilled inclusion criteria and were reviewed. 22: USA, UK; 3: Holland, Sweden, Australia. Major themes identified: need for knowledge and information, choice and support; concerns about confidentiality, cost, fear, anxiety and stigma. Women are more likely to find chlamydia screening/testing acceptable if they think chlamydia is a serious, common condition which can cause infertility and if they understand that chlamydia infection can be asymptomatic. Women want a range of options for chlamydia testing including urine tests, self-administered swabs, pelvic exams and clinician-collected swabs, home-testing and community-based testing. Tests should be free, easy and quick. Women want support for dealing with the implications of a chlamydia diagnosis, they feel chlamydia diagnoses need to be normalised and destigmatised and they want assistance with partner notification. Women need to know that their confidentiality will be maintained. CONCLUSION: Our review found that women from various countries and ethnic backgrounds share similar views regarding chlamydia screening, testing and diagnosis. The acknowledged importance of women's views in planning an effective chlamydia screening program is expanded in this review which details the nature and complexity of such views and considers their likely impact

    Aspergillus antigen induces robust Th2 cytokine production, inflammation, airway hyperreactivity and fibrosis in the absence of MCP-1 or CCR2

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    BACKGROUND: Asthma is characterized by type 2 T-helper cell (Th2) inflammation, goblet cell hyperplasia, airway hyperreactivity, and airway fibrosis. Monocyte chemoattractant protein-1 (MCP-1 or CCL2) and its receptor, CCR2, have been shown to play important roles in the development of Th2 inflammation. CCR2-deficient mice have been found to have altered inflammatory and physiologic responses in some models of experimental allergic asthma, but the role of CCR2 in contributing to inflammation and airway hyperreactivity appears to vary considerably between models. Furthermore, MCP-1-deficient mice have not previously been studied in models of experimental allergic asthma. METHODS: To test whether MCP-1 and CCR2 are each required for the development of experimental allergic asthma, we applied an Aspergillus antigen-induced model of Th2 cytokine-driven allergic asthma associated with airway fibrosis to mice deficient in either MCP-1 or CCR2. Previous studies with live Aspergillus conidia instilled into the lung revealed that MCP-1 and CCR2 play a role in anti-fungal responses; in contrast, we used a non-viable Aspergillus antigen preparation known to induce a robust eosinophilic inflammatory response. RESULTS: We found that wild-type C57BL/6 mice developed eosinophilic airway inflammation, goblet cell hyperplasia, airway hyperreactivity, elevations in serum IgE, and airway fibrosis in response to airway challenge with Aspergillus antigen. Surprisingly, mice deficient in either MCP-1 or CCR2 had responses to Aspergillus antigen similar to those seen in wild-type mice, including production of Th2 cytokines. CONCLUSION: We conclude that robust Th2-mediated lung pathology can occur even in the complete absence of MCP-1 or CCR2
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