160 research outputs found

    Life history, habitat utilisation, and biomass of introduced Mysis relicta

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    AbstractLife history, habitat utilisation, and biomass of benthic and pelagic opossum shrimp (Mysis relicta) were studied in the oligotrophic Lake Jonsvatn, central Norway. Sampling in the pelagic zone was done by means of a closing zooplankton net; in the benthic zone by means of a benthic beam trawl.M. relicta had a mixed one or two year life cycle. In the autumn, the proportion of mature females and males were larger in the pelagic than in the benthic habitat. Copulation took place in late autumn, and the first females with eggs occurred in November. In February, the first juvenile M. relicta were released in the benthic habitat. In May and July, however, juveniles were found in large numbers in all parts of the lake. The length distribution of M. relicta indicates that juveniles partly segregate between benthic and pelagic habitats.Both juvenile and adult M. relicta performed vertical diel migrations in the pelagic habitat. In the benthic habitat, diel vertical migrations along the bottom were not as pronounced as vertical migrations in the pelagic habitat. In the benthic habitat, major migrations were performed only by adults in the autumn. Our results indicate that the light intensity in the green part of the spectrum gives the proximate cue for regulation of vertical distribution of M. relicta.The mean total biomass varied between 288 and 1576 kg dry weight, corresponding to 23.2–127.1 mg dry weight m−2 surface area. M. relicta had smallest biomass during late spring/early summer and largest biomass during autumn and early winter. Estimated pelagic biomasses were largest in February, August, October and November, while benthic biomasses were largest in May and July. Estimated biomass of pelagic M. relicta during autumn was approximately 1/10 of the estimated biomass of zooplankton in this lake

    Short range ferromagnetism and spin glass state in Y0.7Ca0.3MnO3\mathrm{Y_{0.7}Ca_{0.3}MnO_{3}}

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    Dynamic magnetic properties of Y0.7Ca0.3MnO3\mathrm{Y_{0.7}Ca_{0.3}MnO_{3}} are reported. The system appears to attain local ferromagnetic order at TSRF≈70T_{\mathrm{SRF}} \approx 70 K. Below this temperature the low field magnetization becomes history dependent, i.e. the zero field cooled (ZFC) and field cooled (FC) magnetization deviate from each other and closely logarithmic relaxation appears at our experimental time scales (0.3-10410^{4} sec). The zero field cooled magnetization has a maximum at Tf≈30T_{\mathrm{f}}\approx 30 K, whereas the field cooled magnetization continues to increase, although less sharply, also below this temperature. Surprisingly, the dynamics of the system shows non-equilibrium spin glass (SG) features not only below the maximum in the ZFC magnetization, but also in the temperature region between this maximum and TSRFT_{\mathrm{SRF}}. The aging and temperature cycling experiments show only quantitative differences in the dynamic behavior above and below the maximum in the ZFC-magnetization; similarly, memory effects are observed in both temperature regions. We attribute the high temperature behavior to the existence of clusters of short range ferromagnetic order below TSRFT_{\mathrm{SRF}}; the configuration evolves into a conventional spin glass state at temperatures below TfT_{\mathrm{f}}.Comment: REVTeX style; 8 pages, 8 figure

    Relationship Between Non-Hodgkin's Lymphoma and Blood Levels of Epstein-Barr Virus in Children in North-Western Tanzania: A Case Control Study.

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    Non-Hodgkin's Lymphomas (NHL) are common in African children, with endemic Burkitt's lymphoma (BL) being the most common subtype. While the role of Epstein-Barr Virus (EBV) in endemic BL is known, no data are available about clinical presentations of NHL subtypes and their relationship to Human Immunodeficiency Virus (HIV) infection and Epstein Barr Virus (EBV) load in peripheral blood of children in north-western, Tanzania. A matched case control study of NHL subtypes was performed in children under 15 years of age and their respective controls admitted to Bugando Medical Centre, Sengerema and Shirati district designated hospitals in north-western, Tanzania, between September 2010 and April 2011. Peripheral blood samples were collected on Whatman 903 filter papers and EBV DNA levels were estimated by multiplex real-time PCR. Clinical and laboratory data were collected using a structured data collection tool and analysed using chi-square, Fisher and Wilcoxon rank sum tests where appropriate. The association between NHL and detection of EBV in peripheral blood was assessed using conditional logistic regression model and presented as odds ratios (OR) and 95% confidence intervals (CI). A total of 35 NHL cases and 70 controls matched for age and sex were enrolled. Of NHLs, 32 had BL with equal distribution between jaw and abdominal tumour, 2 had large B cell lymphoma (DLBCL) and 1 had NHL-not otherwise specified (NHL-NOS). Central nervous system (CNS) presentation occurred only in 1 BL patient; 19 NHLs had stage I and II of disease. Only 1 NHL was found to be HIV-seropositive. Twenty-one of 35 (60%) NHL and 21 of 70 (30%) controls had detectable EBV in peripheral blood (OR = 4.77, 95% CI 1.71 - 13.33, p = 0.003). In addition, levels of EBV in blood were significantly higher in NHL cases than in controls (p = 0.024). BL is the most common childhood NHL subtype in north-western Tanzania. NHLs are not associated with HIV infection, but are strongly associated with EBV load in peripheral blood. The findings suggest that high levels of EBV in blood might have diagnostic and prognostic relevance in African children

    Static chaos and scaling behaviour in the spin-glass phase

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    We discuss the problem of static chaos in spin glasses. In the case of magnetic field perturbations, we propose a scaling theory for the spin-glass phase. Using the mean-field approach we argue that some pure states are suppressed by the magnetic field and their free energy cost is determined by the finite-temperature fixed point exponents. In this framework, numerical results suggest that mean-field chaos exponents are probably exact in finite dimensions. If we use the droplet approach, numerical results suggest that the zero-temperature fixed point exponent ξ\theta is very close to d−32\frac{d-3}{2}. In both approaches d=3d=3 is the lower critical dimension in agreement with recent numerical simulations.Comment: 28 pages + 6 figures, LateX, figures uuencoded at the end of fil

    Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions

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    Background: Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions. Methods: These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies. Results: Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level. Conclusions: These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible

    Mean-field theory of temperature cycling experiments in spin-glasses

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    We study analytically the effect of temperature cyclings in mean-field spin-glasses. In accordance with real experiments, we obtain a strong reinitialization of the dynamics on decreasing the temperature combined with memory effects when the original high temperature is restored. The same calculation applied to mean-field models of structural glasses shows no such reinitialization, again in accordance with experiments. In this context, we derive some relations between experimentally accessible quantities and propose new experimental protocols. Finally, we briefly discuss the effect of field cyclings during isothermal aging.Comment: Some misprints corrected, references updated, final version to apper in PR

    Tumoral CD105 is a novel independent prognostic marker for prognosis in clear-cell renal cell carcinoma

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    International audienceBackground: Angiogenesis is essential for tumour growth and metastasis. There are conflicting reports as to whether microvessel density (MVD) using the endothelial marker CD105 (cluster of differentiation molecule 105) in clear-cell renal cell carcinomas (ccRCC) is associated with prognosis. Recently, CD105 has been described as a RCC cancer stem cell marker.Methods: A total of 102 ccRCC were analysed. Representative tumour sections were stained for CD105. Vascularity (endothelial CD105) was quantified by MVD. The immunohistochemistry analysis detected positive (if present) or negative (if absent) CD105 tumoral staining. This retrospective population-based study was evaluated using Kaplan–Meier method, t-test and Cox proportional hazard model.Results: We found that the expression of endothelial CD105 (MVD) negatively correlated with nuclear grade (P<0.001), tumour stage (P<0.001) and Leibovitch score (P<0.001), whereas the expression of tumoral CD105 positively correlated with these three clinicopathological factors (P<0.001). In multivariate analysis, tumoral CD105 was found to be an independent predictor of poor overall survival (P=0.002).Conclusions: We have shown for the first time that tumoral CD105 is an independent predictive marker for death risk and unfavourable prognosis in patients with ccRCC after curative resection

    Influence of virtual reality soccer game on walking performance in robotic assisted gait training for children

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    BACKGROUND: Virtual reality (VR) offers powerful therapy options within a functional, purposeful and motivating context. Several studies have shown that patients' motivation plays a crucial role in determining therapy outcome. However, few studies have demonstrated the potential of VR in pediatric rehabilitation. Therefore, we developed a VR-based soccer scenario, which provided interactive elements to engage patients during robotic assisted treadmill training (RAGT). The aim of this study was to compare the immediate effect of different supportive conditions (VR versus non-VR conditions) on motor output in patients and healthy control children during training with the driven gait orthosis Lokomat*. METHODS: A total of 18 children (ten patients with different neurological gait disorders, eight healthy controls) took part in this study. They were instructed to walk on the Lokomat in four different, randomly-presented conditions: (1) walk normally without supporting assistance, (2) with therapists' instructions to promote active participation, (3) with VR as a motivating tool to walk actively and (4) with the VR tool combined with therapists' instructions. The Lokomat gait orthosis is equipped with sensors at hip and knee joint to measure man-machine interaction forces. Additionally, subjects' acceptance of the RAGT with VR was assessed using a questionnaire. RESULTS: The mixed ANOVA revealed significant main effects for the factor CONDITIONS (p < 0.001) and a significant interaction CONDITIONS x GROUP (p = 0.01). Tests of between-subjects effects showed no significant main effect for the GROUP (p = 0.592). Active participation in patients and control children increased significantly when supported and motivated either by therapists' instructions or by a VR scenario compared with the baseline measurement "normal walking" (p < 0.001). CONCLUSIONS: The VR scenario used here induces an immediate effect on motor output to a similar degree as the effect resulting from verbal instructions by the therapists. Further research needs to focus on the implementation of interactive design elements, which keep motivation high across and beyond RAGT sessions, especially in pediatric rehabilitation

    Wellness through a comprehensive Yogic breathing program – A controlled pilot trial

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    <p>Abstract</p> <p>Background</p> <p>Increasing rates of psychosocial disturbances give rise to increased risks and vulnerability for a wide variety of stress-related chronic pain and other illnesses. Relaxation exercises aim at reducing stress and thereby help prevent these unwanted outcomes. One of the widely used relaxation practices is yoga and yogic breathing exercises. One specific form of these exercises is Sudarshan Kriya and related practices (SK&P) which are understood to have favourable effects on the mind-body system. The goal of this pilot study was to design a protocol that can investigate whether SK&P can lead to increased feeling of wellness in healthy volunteers.</p> <p>Methods</p> <p>Participants were recruited in a small university city in Sweden and were instructed in a 6-day intensive program of SK&P which they practiced daily for six weeks. The control group was instructed to relax in an armchair each day during the same period. Subjects included a total of 103 adults, 55 in the intervention (SK&P) group and 48 in the control group. Various instruments were administered before and after the intervention. Hospital Anxiety Depression Scale measured the degree of anxiety and depression, Life Orientation Test measured dispositional optimism, Stress and Energy Test measured individual's energy and stress experiences. Experienced Deviation from Normal State measured the experience of altered state of consciousness.</p> <p>Results</p> <p>There were no safety issues. Compliance was high (only 1 dropout in the SK&P group, and 5 in the control group). Outcome measures appeared to be appropriate for assessing the differences between the groups. Subjective reports generally correlated with the findings from the instruments. The data suggest that participants in the SK&P group, but not the control group, lowered their degree of anxiety, depression and stress, and also increased their degree of optimism (ANOVA; p < 0.001). The participants in the yoga group experienced the practices as a positive event that induced beneficial effects.</p> <p>Conclusion</p> <p>These data indicate that the experimental protocol that is developed here is safe, compliance level is good, and a full scale trial is feasible. The data obtained suggest that adult participants may improve their wellness by learning and applying a program based on yoga and yogic breathing exercises; this can be conclusively assessed in a large-scale trial.</p> <p>Trial Registration</p> <p>Australian Clinical Trial Registry ACTRN012607000175471.</p
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