Dielectric study of the glass transition: correlation with calorimetric data

The glass transition in amorphous poly(ethylene terephthalate) is studied by thermally stimulated depolarization currents (TSDC) and differential scanning calorimetry (DSC). The ability of TSDC to decompose a distributed relaxation, as the glass transition, into its elementary components is demonstrated. Two polarization techniques, windows polarization (WP) and non-isothermal windows polarization (NIW), are employed to assess the influence of thermal history in the results. The Tool-Narayanaswami-Moynihan (TNM) model has been used to fit the TSDC spectra. The most important contributions to the relaxation comes from modes with non-linearity (x) around 0.7. Activation energies yield by this model are located around 1eV for polarization temperature (Tp) below 50C and they raise up to values higher than 8eV as Tp increases (up to 80C). There are few differences between results obtained with WP and NIW but, nonetheless, these are discussed. The obtained kinetic parameters are tested against DSC results in several conditions. Calculated DSC curves at several cooling and heating rates can reproduce qualitatively experimental DSC results. These results also demonstrate that modelization of the non-equilibrium kinetics involved in TSDC spectroscopy is a useful experimental tool for glass transition studies in polar polymers.Comment: 13 pages, 2 tables, 10 figures; minor change

A comprehensive fracture prevention strategy in older adults : The European union geriatric medicine society (EUGMS) statement

Published also in Aging Clinical and Experimental Research, Vol.28, No.4, WOS: 000379034800030Prevention of fragility fractures in older people has become a public health priority, although the most appropriate and cost-effective strategy remains unclear. In the present statement, the Interest group on falls and fracture prevention of the European union geriatric medicine society (EUGMS), in collaboration with the International association of gerontology and geriatrics for the European region (IAGG-ER), the European union of medical specialists (EUMS), the Fragility fracture network (FFN), the International osteoporosis foundation (IOF) - European society for clinical and economic aspects of osteoporosis and osteoarthritis (ECCEO), outlines its views on the main points in the current debate in relation to the primary and secondary prevention of falls, the diagnosis and treatment of bone fragility, and the place of combined falls and fracture liaison services for fracture prevention in older people. (C) 2016 Published by Elsevier Masson SAS.Peer reviewe

Construction, assembly and tests of the ATLAS electromagnetic end-cap calorimeters

The construction and the assembly of the two end-caps of the ATLAS liquid argon electromagnetic calorimeter as well as their test and qualification programs are described. The work described here started at the beginning of 2001 and lasted for approximately three years. The results of the qualification tests performed before installation in the LHC ATLAS pit are given. The detectors are now installed in the ATLAS cavern, full of liquid argon and being commissioned. The complete detectors coverage is powered with high voltage and readout

Performance of a large scale prototype of the ATLAS accordion electromagnetic calorimeter

A 2 m long prototype of a lead-liquid argon electromagnetic calorimeter with accordion-shaped electrodes, conceived as a sector of the barrel calorimeter of the future ATLAS experiment at the LHC, has been tested with electron and pion beams in the energy range 10 to 287 GeV. A sampling term of 10%/root E(GeV) was obtained for electrons in the rapidity range 0 < eta < 1, while the constant term measured over an area of about 1 m(2) is 0.69%. With a cell size of 2.7 cm the position resolution is. about 4 mm/root E(GeV)

Performance of an endcap prototype of the ATLAS accordion electromagnetic calorimeter

The design and construction of a lead-liquid argon endcap calorimeter prototype using an accordion geometry and conceived as a sector of the inner wheel of the endcap calorimeter of the future ATLAS experiment at the LHC is described. The performance obtained using electron beam data is presented. The main results are an energy resolution with a sampling term below $11\%/\sqrt{E(\rm GeV)}$ and a small local constant term, a good linearity of the response with the incident energy and a global constant term of 0.8\% over an extended area in the rapidity range of $2.2 < \eta <2.9$. These properties make the design suitable for the ATLAS electromagnetic endcap calorimeter

Exact Vlasov-Maxwell equilibria for asymmetric current sheets

The NASA Magnetospheric Multiscale mission has made in situ diffusion region and kinetic-scale resolution measurements of asymmetric magnetic reconnection for the first time, in the Earth's magnetopause. The principal theoretical tool currently used to model collisionless asymmetric reconnection is particle-in-cell simulations. Many particle-in-cell simulations of asymmetric collisionless reconnection start from an asymmetric Harris-type magnetic field but with distribution functions that are not exact equilibrium solutions of the Vlasov equation. We present new and exact equilibrium solutions of the Vlasov-Maxwell system that are self-consistent with one-dimensional asymmetric current sheets, with an asymmetric Harris-type magnetic field profile, plus a constant nonzero guide field. The distribution functions can be represented as a combination of four shifted Maxwellian distribution functions. This equilibrium describes a magnetic field configuration with more freedom than the previously known exact solution and has different bulk flow properties

Fatores de risco para fratura por osteoporose e baixa densidade óssea em mulheres na pré e pós-menopausa

OBJECTIVE: To estimate the prevalence and analyze risk factors associated to osteoporosis and low-trauma fracture in women. METHODS: Cross-sectional study including a total of 4,332 women older than 40 attending primary care services in the Greater São Paulo, Southeastern Brazil, between 2004 and 2007. Anthropometrical and gynecological data and information about lifestyle habits, previous fracture, medical history, food intake and physical activity were obtained through individual quantitative interviews. Low-trauma fracture was defined as that resulting from a fall from standing height or less in individuals 50 years or older. Multiple logistic regression models were designed having osteoporotic fracture and bone mineral density (BMD) as the dependent variables and all other parameters as the independent ones. The significance level was set at p<0.05. RESULTS: The prevalence of osteoporosis and osteoporotic fractures was 33% and 11.5%, respectively. The main risk factors associated with low bone mass were age (OR=1.07; 95% CI: 1.06;1.08), time since menopause (OR=2.16; 95% CI: 1.49;3.14), previous fracture (OR=2.62; 95% CI: 2.08;3.29) and current smoking (OR=1.45; 95% CI: 1.13;1.85). BMI (OR=0.88; 95% CI: 0.86;0.89), regular physical activity (OR=0.78; 95% CI: 0.65;0.94) and hormone replacement therapy (OR=0.43; 95% CI: 0.33;0.56) had a protective effect on bone mass. Risk factors significantly associated with osteoporotic fractures were age (OR=1.05; 95% CI: 1.04;1.06), time since menopause (OR=4.12; 95% CI: 1.79;9.48), familial history of hip fracture (OR=3.59; 95% CI: 2.88;4.47) and low BMD (OR=2.28; 95% CI: 1.85;2.82). CONCLUSIONS: Advanced age, menopause, low-trauma fracture and current smoking are major risk factors associated with low BMD and osteoporotic fracture. The clinical use of these parameters to identify women at higher risk for fractures might be a reasonable strategy to improve the management of osteoporosis.OBJETIVO: Estimar la prevalencia y analizar los factores de riesgo asociados con osteoporosis y fractura por bajo impacto entre mujeres. MÉTODOS: Estudio transversal realizado con 4.332 mujeres encima de 40 años de edad provenientes de atención primaria de salud en el área metropolitana de la gran São Paulo, SP, entre 2004 2007. Datos antropométricos y ginecológico y relativos a hábitos de vida, fractura previa, antecedentes personales, ingestión alimentaria y actividad física fueron evaluados por medio de entrevista individual y cuantitativa. Fractura por bajo impacto fue definida como decurrente de caída de la propia altura o menos en individuos con más de 50 años de edad. Modelos de regresión multivariada y logística analizaron, respectivamente, la densidad ósea y la fractura por osteoporosis, como variables dependientes y todas las otras como independientes. El nivel de significancia estadística establecido fue p<0,05. RESULTADOS: La prevalencia de osteoporosis y de fracturas por fragilidad ósea fue de 33% y 11,5%, respectivamente. Los principales factores de riesgo asociados con baja densidad ósea fueron edad (OR=1,07; IC 95%: 1,06;1,08), menopausia (OR=2,16; IC 95%: 1,49;3,14), fractura previa (OR=2,62; IC 95%: 2,08;3,29) y tabaquismo actual (OR=1,45; IC 95%: 1,13;1,85). Por otro lado, elevado IMC (OR=0,88; IC 95%: 0,86;0,89), actividad física regular (OR=0,78; IC 95%: 0,65;0,94) y terapia hormonal actual (OR=0,43; IC 95%: 0,33;0,56) desempeñaron papel protector. Los factores de riesgo significantemente relacionados con fractura por osteoporosis fueron edad (OR=1,05; IC 95%: 1,04;1,06), menopausia (OR=4,12; IC 95%: 1,79;9,48), historia familiar de fractura de cuadril (OR=3,59; IC 95%: 2,88;4,47) y baja densidad ósea (OR=2,28; IC 95%: 1,85;2,82). CONCLUSIONES: Edad avanzada, menopausia, fractura previa por bajo impacto y tabaquismo actual son los principales factores de riesgo asociados con baja densidad ósea y esta, con las fracturas por fragilidad ósea. El uso clínico de estos parámetros para identificar mujeres de mayor riesgo para fracturas puede ser una estrategia interesante para mejorar el abordaje de la osteoporosis.OBJETIVO: Estimar a prevalência e analisar os fatores de risco associados com osteoporose e fratura por baixo impacto entre mulheres. MÉTODOS: Estudo transversal realizado com 4.332 mulheres acima de 40 anos de idade provenientes de atendimento primário de saúde na área metropolitana da Grande São Paulo, SP, entre 2004 e 2007. Dados antropométricos e ginecológicos e relativos a hábitos de vida, fratura prévia, antecedentes pessoais, ingestão alimentar e atividade física foram avaliados por meio de entrevista individual e quantitativa. Fratura por baixo impacto foi definida como decorrente de queda da própria altura ou menos em indivíduos com mais de 50 anos de idade. Modelos de regressão multivariada e logística analisaram, respectivamente, a densidade óssea e a fratura por osteoporose como variáveis dependentes e todas as outras como independentes. O nível de significância estatística estabelecido foi p < 0,05. RESULTADOS: A prevalência de osteoporose e de fraturas por fragilidade óssea foi de 33% e 11,5%, respectivamente. Os principais fatores de risco associados com baixa densidade óssea foram idade (OR = 1,07; IC 95%: 1,06;1,08), menopausa (OR = 2,16; IC 95%: 1,49;3,14), fratura prévia (OR = 2,62; IC 95%: 2,08;3,29) e tabagismo atual (OR = 1,45; IC 95%: 1,13;1,85). Por outro lado, elevado IMC (OR = 0,88; IC 95%: 0,86;0,89), atividade física regular (OR = 0,78; IC 95%: 0,65;0,94) e terapia hormonal atual (OR = 0,43; IC 95%: 0,33;0,56) desempenharam papel protetor. Os fatores de risco significativamente relacionados com fratura por osteoporose foram idade (OR = 1,05; IC 95%: 1,04;1,06), menopausa (OR = 4,12; IC 95%: 1,79;9,48), história familiar de fratura de quadril (OR = 3,59; IC 95%: 2,88;4,47) e baixa densidade óssea (OR = 2,28; IC 95%: 1,85;2,82). CONCLUSÕES: Idade avançada, menopausa, fratura prévia por baixo impacto e tabagismo atual são os principais fatores de risco associados com baixa densidade óssea, a qual se associa com as fraturas por fragilidade óssea. O uso clínico desses parâmetros para identificar mulheres de maior risco para fraturas pode ser uma estratégia interessante para melhorar a abordagem da osteoporose.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP-EPM Instituto de Diagnóstico por ImagemUNIFESP-EPM Programa de Pós-Graduação em ReumatologiaUNIFESP-EPM Departamento de RadiologiaUNIFESP, EPM, Instituto de Diagnóstico por ImagemUNIFESP, EPM Programa de Pós-Graduação em ReumatologiaUNIFESP, EPM Depto. de RadiologiaSciEL

Bringing Back a Healthy Buzz? Invertebrate Parasites and Reintroductions:A Case Study in Bumblebees

Reintroductions can play a key role in the conservation of endangered species. Parasites may impact reintroductions, both positively and negatively, but few case studies of how to manage parasites during reintroductions exist. Bumblebees are in decline at regional and global scales, and reintroductions can be used to re-establish extinct local populations. Here we report on how the risks associated with parasites are being managed in an ongoing reintroduction of the short-haired bumblebee, Bombus subterraneus, to the UK. Disease risk analysis was conducted and disease risk management plans constructed to design a capture-quarantine-release system that minimised the impacts on both the bumblebees and on their natural parasites. Given that bumblebee parasites are (i) generalists, (ii) geographically ubiquitous, and (iii) show evidence of local adaptation, the disease risk management plan was designed to limit the co-introduction of parasites from the source population in Sweden to the destination site in the UK. Results suggest that this process at best eliminated, or at least severely curtailed the co-introduction of parasites, and ongoing updates of the plan enabled minimization of impacts on natural host-parasite dynamics in the Swedish source population. This study suggests that methods designed for reintroductions of vertebrate species can be successfully applied to invertebrates. Future reintroductions of invertebrates where the parasite fauna is less well known should take advantage of next-generation barcoding and multiple survey years prior to the start of reintroductions, to develop comprehensive disease risk management plans

Modulation of the <i>Neisseria gonorrhoeae </i>drug efflux conduit MtrE

We acknowledge funding through the Wellcome Trust Interdisciplinary Research Funds (grant WT097818MF), the Scottish Universities’ Physics Alliance (SUPA), Tenovus Tayside (grant T16/30) and the Tayside Charitable Trust. O.N.V. has been funded through a BBSRC CASE award (BB/J013072/1).Widespread antibiotic resistance, especially of Gram-negative bacteria, has become a severe concern for human health. Tripartite efflux pumps are one of the major contributors to resistance in Gram-negative pathogens, by efficiently expelling a broad spectrum of antibiotics from the organism. In Neisseria gonorrhoeae, one of the first bacteria for which pan-resistance has been reported, the most expressed efflux complex is MtrCDE. Here we present the electrophysiological characterisation of the outer membrane component MtrE and the membrane fusion protein MtrC, obtained by a combination of planar lipid bilayer recordings and in silico techniques. Our in vitro results show that MtrE can be regulated by periplasmic binding events and that the interaction between MtrE and MtrC is sufficient to stabilize this complex in an open state. In contrast to other efflux conduits, the open complex only displays a slight preference for cations. The maximum conductance we obtain in the in vitro recordings is comparable to that seen in our computational electrophysiology simulations conducted on the MtrE crystal structure, indicating that this state may reflect a physiologically relevant open conformation of MtrE. Our results suggest that the MtrC/E binding interface is an important modulator of MtrE function, which could potentially be targeted by new efflux inhibitors.Publisher PDFPeer reviewe