742 research outputs found

    Age modification of the relationship between C-reactive protein and fatigue: findings from Understanding Society (UKHLS)

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    Background: Systemic inflammation may play a role in the development of idiopathic fatigue, that is, fatigue not explained by infections or diagnosed chronic illness, but this relationship has never been investigated in community studies including the entire adult age span. We examine the association of the inflammatory marker C-reactive protein (CRP) and fatigue assessed annually in a 3-year outcome period for UK adults aged 16–98. Methods: Multilevel models were used to track fatigue 7, 19, and 31 months after CRP measurement, in 10 606 UK individuals. Models accounted for baseline fatigue, demographics, health conditions diagnosed at baseline and during follow-up, adiposity, and psychological distress. Sensitivity analyses considered factors including smoking, sub-clinical disease (blood pressure, anaemia, glycated haemoglobin), medications, ethnicity, and alcohol consumption. Results: Fatigue and CRP increased with age, and women had higher values than men. CRP was associated with future self-reported fatigue, but only for the oldest participants. Thus, in those aged 61–98 years, high CRP ( > 3 mg/L) independently predicted greater fatigue 7, 19, and 31 months after CRP measurement [odds ratio for new-onset fatigue after 7 months: 1.88, 95% confidence interval (CI) 1.21–2.92; 19 months: 2.25, CI 1.46–3.49; 31 months: 1.65, CI 1.07–2.54]. No significant longitudinal associations were seen for younger participants. Conclusions: Our findings support previously described CRP–fatigue associations in older individuals. However, there are clear age modifications in these associations, which may reflect a contribution of unmeasured sub-clinical disease of limited relevance to younger individuals. Further work is necessary to clarify intervening processes linking CRP and fatigue in older individuals

    Investigación conductual sobre memoria de trabajo: integrando métodos cualitativos y cuantitativos

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    The long lasting opposition between qualitative and quantitative methods for studying behaviour has been overridden by interdisciplinary work in which methods can be combined to approach animal and human behaviour, thus contributing to drawing rigorous and useful conclusions. We show an example of this by combining a quasi-experimental design and descriptive methods to study working memory for the resolution of a spatial problem task (the Tower of Hanoi) in a neuropsychiatric hospital inpatient with amnesia and executive deficits. Results from the quasi-experiment showed that the patient acquired strategies to solve the task with a high level of efficiency (F3/35 = 7, 19, p < .01). Qualitatively speaking, the patient developed more than one strategy to solve the problem, which indicates the presence of learning based on working memory. In the light of these findings, we discuss issues of mixed methods research and suggest the importance of developing mixed methods to study behaviour. Key words: Behavioural research, mixed methods, Tower of Hanoi, working memory RESUMEN La oposición duradera entre métodos cualitativos y cuantitativos para estudiar el comportamiento ha sido anulada por el trabajo interdisciplinario en que los métodos pueden combinarse para enfocar el comportamiento humano y animal, contribuyendo así a obtener conclusiones útiles y rigurosas. Se presenta una muestra, combinando métodos descriptivos y un diseño cuasiexperimental para estudiar la memoria de trabajo en la resolución de una tarea de problema espacial (la Torre de Hanoi), en un paciente internado en un hospital neuropsiquiátrico con amnesia y déficit ejecutivo. Resultados del cuasiexperimento demostraron que el paciente adquirió estrategias para resolver la tarea con un alto nivel de eficiencia (F3/35 = 7, 19, p < .01). Cualitativamente el paciente desarrolló más de una estrategia para resolver el problema, lo cual indica la presencia de aprendizaje basado en memoria de trabajo. A la luz de estos resultados, se discuten métodos de investigación mixtos y se sugiere la importancia de desarrollar métodos mixtos para estudiar el comportamiento.La oposición duradera entre métodos cualitativos y cuantitativos para estudiar el comportamiento ha sido anulada por el trabajo interdisciplinario en que los métodos pueden combinarse para enfocar el comportamiento humano y animal, contribuyendo así a obtener conclusiones útiles y rigurosas. Se presenta una muestra, combinando métodos descriptivos y un diseño cuasiexperimental para estudiar la memoria de trabajo en la resolución de una tarea de problema espacial (la Torre de Hanoi), en un paciente internado en un hospital neuropsiquiátrico con amnesia y déficit ejecutivo. Resultados del cuasiexperimento demostraron que el paciente adquirió estrategias para resolver la tarea con un alto nivel de eficiencia (F3/35 = 7, 19, p < .01). Cualitativamente el paciente desarrolló más de una estrategia para resolver el problema, lo cual indica la presencia de aprendizaje basado en memoria de trabajo. A la luz de estos resultados, se discuten métodos de investigación mixtos y se sugiere la importancia de desarrollar métodos mixtos para estudiar el comportamiento.Fil: Bacigalupe, Maria de Los Angeles. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Division Etnografia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tujague, María Paula. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Spath, Griselda M.. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Division Etnografia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lahitte, Hector Blas. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Division Etnografia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Semiclassical time--dependent propagation in three dimensions: How accurate is it for a Coulomb potential?

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    A unified semiclassical time propagator is used to calculate the semiclassical time-correlation function in three cartesian dimensions for a particle moving in an attractive Coulomb potential. It is demonstrated that under these conditions the singularity of the potential does not cause any difficulties and the Coulomb interaction can be treated as any other non-singular potential. Moreover, by virtue of our three-dimensional calculation, we can explain the discrepancies between previous semiclassical and quantum results obtained for the one-dimensional radial Coulomb problem.Comment: 8 pages, 4 figures (EPS

    Explant-derived human dental pulp stem cells enhance differentiation and proliferation potentials

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    Numerous stem cell niches are present in the different tissues and organs of the adult human body. Among these tissues, dental pulp, entrapped within the 'sealed niche' of the pulp chamber, is an extremely rich site for collecting stem cells. In this study, we demonstrate that the isolation of human dental pulp stem cells by the explants culture method (hD-DPSCs) allows the recovery of a population of dental mesenchymal stem cells that exhibit an elevated proliferation potential. Moreover, we highlight that hD-DPSCs are not only capable of differentiating into osteoblasts and chondrocytes but are also able to switch their genetic programme when co-cultured with murine myoblasts. High levels of MyoD expression were detected, indicating that muscle-specific genes in dental pulp cells can be turned on through myogenic fusion, confirming thus their multipotency. A perivascular niche may be the potential source of hD-DPSCs, as suggested by the consistent Ca(2+) release from these cells in response to endothelin-1 (ET-1) treatment, which is also able to significantly increase cell proliferation. Moreover, response to ET-1 has been found to be superior in hD-DPSCs than in DPSCs, probably due to the isolation method that promotes release of stem/progenitor cells from perivascular structures. The ability to isolate, expand and direct the differentiation of hD-DPSCs into several lineages, mainly towards myogenesis, offers an opportunity for the study of events associated with cell commitment and differentiation. Therefore, hD-DPSCs display enhanced differentiation abilities when compared to DPSCs, and this might be of relevance for their use in therapy

    The structural analysis of Cu(111)-Te (√3 × √3) R30° and (2√3 × 2√3)R30° surface phases by quantitative LEED and DFT,

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    The chemisorption of tellurium on atomically clean Cu(111) surface has been studied under ultra-high vacuum conditions. At room temperature, the initial stage of growth was an ordered 23×23R30° phase (0.08 ML). An ordered 3×3R30° phase is formed at 0.33 ML coverage of Te. The adsorption sites of the Te atoms on the Cu(111) surface at 0.08 ML and 0.33 ML coverages are explored by quantitative low energy electron diffraction (LEED) and density functional theory (DFT). Our results indicate that substitutional surface alloy formation starts at very low coverages

    Prospects for the development of odour baits to control the tsetse flies Glossina tachinoides and G. palpalis s.l.

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    Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (~5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2×) the trap catch significantly but not the catch from electric targets. For G. p. palpalis, odours from pigs and humans increased (~5×) the numbers of tsetse attracted to the vicinity of the odour source but had little effect on landing or trap-entry. For G. tachinoides a blend of POCA (P = 3-n-propylphenol; O = 1-octen-3-ol; C = 4-methylphenol; A = acetone) alone or synthetic cattle odour (acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol with carbon dioxide) consistently caught more tsetse than natural cattle odour. For G. p. gambiensis, POCA consistently increased catches from both traps and targets. For G. p. palpalis, doses of carbon dioxide similar to those produced by a host resulted in similar increases in attraction. Baiting traps with super-normal (~500 mg/h) doses of acetone also consistently produced significant but slight (~1.6×) increases in catches of male flies. The results suggest that odour-baited traps and insecticide-treated targets could assist the AU-Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) in its current efforts to monitor and control Palpalis group tsetse in West Africa. For all three species, only ~50% of the flies attracted to the vicinity of the trap were actually caught by it, suggesting that better traps might be developed by an analysis of the visual responses and identification of any semiochemicals involved in short-range interaction

    An evaluation of metal removal during wastewater treatment: The potential to achieve more stringent final effluent standards

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Taylor & Francis.Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible requirements for the removal of copper my be challenging

    Deficiency of Leishmania phosphoglycans influences the magnitude but does not affect the quality of secondary (memory) anti-Leishmania immunity

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    Despite inducing very low IFN-γ response and highly attenuated in vivo, infection of mice with phosphoglycan (PG) deficient Leishmania major (lpg2-) induces protection against virulent L. major challenge. Here, we show that mice infected with lpg2- L. major generate Leishmania-specific memory T cells. However, in vitro and in vivo proliferation, IL-10 and IFN-γ production by lpg2- induced memory cells were impaired in comparison to those induced by wild type (WT) parasites. Interestingly, TNF recall response was comparable to WT infected mice. Despite the impaired proliferation and IFN-γ response, lpg2- infected mice were protected against virulent L. major challenge and their T cells mediated efficient infection-induced immunity. In vivo depletion and neutralization studies with mAbs demonstrated that lpg2- L. major-induced resistance was strongly dependent on IFN-γ, but independent of TNF and CD8(+) T cells. Collectively, these data show that the effectiveness of secondary anti-Leishmania immunity depends on the quality (and not the magnitude) of IFN-γ response. These observations provide further support for consideration of lpg2- L. major as a live-attenuated candidate for leishmanization in humans since it protects strongly against virulent challenge, without inducing pathology in infected animals
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