505 research outputs found
Anisotropic Cosmological Constant and the CMB Quadrupole Anomaly
There are evidences that the cosmic microwave background (CMB) large-angle
anomalies imply a departure from statistical isotropy and hence from the
standard cosmological model. We propose a LCDM model extension whose dark
energy component preserves its nondynamical character but wield anisotropic
vacuum pressure. Exact solutions for the cosmological scale factors are
presented, upper bounds for the deformation parameter are evaluated and its
value is estimated considering the elliptical universe proposal to solve the
quadrupole anomaly. This model can be constructed from a Bianchi I cosmology
with cosmological constant from two different ways: i) a straightforward
anisotropic modification of the vacuum pressure consistently with
energy-momentum conservation; ii) a Poisson structure deformation between
canonical momenta such that the dynamics remain invariant under scale factors
rescalings.Comment: 8 pages, 2 columns, 1 figure. v2: figure improved, added comments on
higher eccentricity powers and references. v3: typos corrected, version to
appear in PR
Incidence of mild cognitive impairment and dementia in Parkinson's disease: The Parkinson's disease cognitive impairment study
Background: Cognitive impairment in Parkinson's disease (PD) includes a spectrum varying from Mild Cognitive Impairment (PD-MCI) to PD Dementia (PDD). The main aim of the present study is to evaluate the incidence of PD-MCI, its rate of progression to dementia, and to identify demographic and clinical characteristics which predict cognitive impairment in PD patients. Methods: PD patients from a large hospital-based cohort who underwent at least two comprehensive neuropsychological evaluations were retrospectively enrolled in the study. PD-MCI and PDD were diagnosed according to the Movement Disorder Society criteria. Incidence rates of PD-MCI and PDD were estimated. Clinical and demographic factors predicting PD-MCI and dementia were evaluated using Cox proportional hazard model. Results: Out of 139 enrolled PD patients, 84 were classified with normal cognition (PD-NC), while 55 (39.6%) fulfilled the diagnosis of PD-MCI at baseline. At follow-up (mean follow-up 23.5 ± 10.3 months) 28 (33.3%) of the 84 PD-NC at baseline developed MCI and 4 (4.8%) converted to PDD. The incidence rate of PD-MCI was 184.0/1000 pyar (95% CI 124.7-262.3). At multivariate analysis a negative association between education and MCI development at follow-up was observed (HR 0.37, 95% CI 0.15-0.89; p = 0.03). The incidence rate of dementia was 24.3/1000 pyar (95% CI 7.7-58.5). Out of 55 PD-MCI patients at baseline, 14 (25.4%) converted to PDD, giving an incidence rate of 123.5/1000 pyar (95% CI 70.3-202.2). A five time increased risk of PDD was found in PD patients with MCI at baseline (RR 5.09, 95% CI 1.60-21.4). Conclusion: Our study supports the relevant role of PD-MCI in predicting PDD and underlines the importance of education in reducing the risk of cognitive impairment
Bound vortex states and exotic lattices in multi-component Bose-Einstein condensates: The role of vortex-vortex interaction
We numerically study the vortex-vortex interaction in multi-component
homogeneous Bose-Einstein condensates within the realm of the Gross-Pitaevskii
theory. We provide strong evidences that pairwise vortex interaction captures
the underlying mechanisms which determine the geometric configuration of the
vortices, such as different lattices in many-vortex states, as well as the
bound vortex states with two (dimer) or three (trimer) vortices. Specifically,
we discuss and apply our theoretical approach to investigate intra- and
inter-component vortex-vortex interactions in two- and three-component
Bose-Einstein condensates, thereby shedding light on the formation of the
exotic vortex configurations. These results correlate with current experimental
efforts in multi-component Bose-Einstein condensates, and the understanding of
the role of vortex interactions in multiband superconductors.Comment: Published in PR
The treatment of hyperinsulinemic hypoglycaemia in adults: an update
Treatment of hyperinsulinemic hypoglycaemia (HH) is challenging due to the rarity of this condition and the difficulty of differential diagnosis. The aim of this article is to give an overview of the recent literature on the management of adult HH
Evolution of Anisotropies in Eddington-Born-Infeld Cosmology
Recently a Born-Infeld action for dark energy and dark matter that uses
additional affine connections was proposed. At background level, it was shown
that the new proposal can mimic the standard cosmological evolution. In Bianchi
cosmologies, contrary to the scalar field approach (e.g., Chaplygin gas), the
new approach leads to anisotropic pressure, raising the issues of stability of
the isotropic solution under anisotropic perturbations and, being it stable,
how the anisotropies evolve. In this work, the Eddington-Born-Infeld proposal
is extended to a Bianchi type I scenario and residual post-inflationary
anisotropies are shown to decay in time. Moreover, it is shown that the shears
decay following a damped oscillatory pattern, instead of the standard
exponential-like decay. Allowing for some fine tuning on the initial
conditions, standard theoretical bounds on the shears can be avoided.Comment: 10 pages, 7 figures. v2: ref. added, v3: figs. improved, new
paragraph in the Conclusions. Accepted in PR
Vascular risk factors, white matter lesions and cognitive impairment in Parkinson’s disease: the PACOS longitudinal study
Background: Vascular risk factors (VRFs) may be associated with cognitive decline in early Parkinson’s disease (PD) but results are inconclusive. The identification of modifiable risk factors is relevant for prevention and treatment. Methods: Parkinson’s disease (PD) patients of the PACOS cohort who underwent a baseline and follow-up neuropsychological evaluation were enrolled in the study. PD with Mild Cognitive Impairment (MCI) and dementia (PDD) were diagnosed according to the MDS criteria. A Baseline 1.5 T brain MRI was used to calculate the white matter lesions (WMLs) burden using the Wahlund visual scale. Laboratory data, presence of hypertension, diabetes and use of anti-hypertensive drugs were collected and the Framingham Risk (FR) score was calculated. VRFs predicting PD-MCI and PDD were evaluated using Cox proportional hazard regression model. Results: Out of 139 enrolled patients, 84 (60.4%) were classified as normal cognition (NC) and 55 (39.6%) as MCI at baseline. At follow-up 28 (33.3%) PD-NC developed MCI and 4 (4.8%) PDD (follow-up time 23.5 ± 10.3 months). Out of 55 PD-MCI patients at baseline, 14 (25.4%) converted to PDD. At multivariate analysis among PD-NC a systolic blood pressure (SBP) > 140 mmHg was the stronger predictor of MCI (adjHR 4.04; 95% CI 1.41–11.3) while the presence of MCI at baseline (adj HR 7.55; 95% CI 1.76–32.3) and a severe WMLs burden (adj HR 2.80; 95% CI 0.86–9.04) were the strongest predictors of PDD, even if this latter association has a trend towards significance. Conclusion: Hypertension represents the most important modifiable risk factor for PD-MCI in the PACOS cohort, increasing the risk of about four times
Quantum corrections to gravity and their implications for cosmology and astrophysics
The quantum contributions to the gravitational action are relatively easy to
calculate in the higher derivative sector of the theory. However, the
applications to the post-inflationary cosmology and astrophysics require the
corrections to the Einstein-Hilbert action and to the cosmological constant,
and those we can not derive yet in a consistent and safe way. At the same time,
if we assume that these quantum terms are covariant and that they have relevant
magnitude, their functional form can be defined up to a single free parameter,
which can be defined on the phenomenological basis. It turns out that the
quantum correction may lead, in principle, to surprisingly strong and
interesting effects in astrophysics and cosmology.Comment: 15 pages, LaTeX, WS style, contribution to the Proceedings of the
QFEXT-2011 conference in the Centro de Ciencias de Benasque Pedro Pasqual,
Spai
Description of hospital pharmacy management practice
Health institutions, particularly hospitals, are characterized as complex structures that need managers with a global view of the institution and its relations with the external environment. The hospital pharmacy is a strategic unit, which cooperates with the institutional management and integrates the multiprofessional team in the process related to the acquisition, provision and control of essential inputs for the inpatient care process. The objective in this study is to demonstrate the applicability, in the context of hospital-based health, of a performance measuring system at the pharmacy. Method: A descriptive and longitudinal study was undertaken on the evolution of the key indicator Absence Rate of Standardized Drugs in inpatient care between March 2004 and December 2013. This indicator was employed to monitor the impact of changes the Pharmacy Division has been implementing, as the first step of the pharmaceutical care cycle in the model of the process-based managed approach at a public university hospital. Qualitative data collection methods were used, including observation and documentary analysis, as well as quantitative data collection. Results: After the application of the model, one point of change in the key performance indicator was detected in the tenth month, when the process-based management model was implemented at the pharmacy. Conclusions: The process-based management approach was effective for the hospital pharmacy. The premise adopted is that the administrative changes (interferences), focused on the improvement of the processes and the selection and monitoring of indicators, influence the processes, reducing the variability and improving the qualityAs instituições de saúde, especialmente hospitais, são caracterizadas como estruturas complexas que precisam de administradores com uma visão global da instituição e de suas relações com o ambiente externo. A farmácia hospitalar é uma unidade estratégica, que colabora com a administração institucional e integra a equipe multiprofissional no processo que tange a aquisição, provisão e controle de insumos essenciais para o processo do atendimento do paciente internado. Este estudo tem como objetivo demonstrar a aplicabilidade, no contexto da saúde hospitalar, de um sistema de medição de desempenho da farmácia. Método: Trata-se de um estudo descritivo, longitudinal, sobre a evolução do indicador chave Taxa de Falta de Medicamentos Padronizados na assistência do paciente internado, no perÃodo de março de 2004 a dezembro de 2013. Esse indicador foi empregado para monitoramento do impacto de mudanças que a Divisão de Farmácia vem implementando, como primeira etapa do ciclo de assistência farmacêutica dentro do modelo da abordagem de gestão por processos, em um hospital público universitário. Foram usados métodos de coleta de dados qualitativos, incluindo a observação e análise documental, bem como coleta de dados quantitativos. Resultados: Após a aplicação do modelo, um ponto de mudança no indicador chave de desempenho, foi detectado no 10º mês, quando o modelo de gestão baseado em processo foi implementado na farmácia. Conclusões: A abordagem de gestão baseada em processos foi eficaz para a farmácia hospitalar. A premissa adotada é que as mudanças administrativas (interferências), com foco na melhoria dos processos e seleção e acompanhamento de indicadores, têm influencia sobre os processos, reduzindo a variabilidade e melhoria da qualidad
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