348 research outputs found
Light propagation and Anderson localization in disordered superlattices containing dispersive metamaterials: Effects of correlated disorder
Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We have investigated the effects of disorder correlations on light propagation and Anderson localization in one-dimensional dispersive metamaterials. We consider and compare the cases where disorder is uncorrelated to situations where it is totally correlated and anticorrelated. The photonic gaps of the corresponding periodic structure are not completely destroyed by the presence of disorder, which leads to minima in the localization length. In the vicinities of a gap, the behavior of the localization length depends crucially on the physical origin of the gap (Bragg or non-Bragg gaps). Within a Bragg gap, the localization length increases as the degree of disorder increases, an anomalous behavior that only occurs for the uncorrelated and completely correlated cases. In these cases, minima of the localization length at the positions of Bragg gaps are shifted by increasing disorder, which does not occur for the anticorrelated case, where the positions of the minima remain unaltered. Minima in the localization length corresponding to non-Bragg gaps are not shifted by increasing disorder, albeit the widths of these minima are changed. We have found that the asymptotic behavior for the localization length xi proportional to lambda(6) for disordered metamaterials is not affected by correlations. Finally, we have investigated the role of absorption on the delocalized Brewster modes and argue that it could be mitigated in light of the state-of-the-art of metamaterials research.849Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian Agency FUJBConselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Coupling models of cattle and farms with models of badgers for predicting the dynamics of bovine tuberculosis (TB)
Bovine TB is a major problem for the agricultural industry in several
countries. TB can be contracted and spread by species other than cattle and
this can cause a problem for disease control. In the UK and Ireland, badgers
are a recognised reservoir of infection and there has been substantial
discussion about potential control strategies. We present a coupling of
individual based models of bovine TB in badgers and cattle, which aims to
capture the key details of the natural history of the disease and of both
species at approximately county scale. The model is spatially explicit it
follows a very large number of cattle and badgers on a different grid size for
each species and includes also winter housing. We show that the model can
replicate the reported dynamics of both cattle and badger populations as well
as the increasing prevalence of the disease in cattle. Parameter space used as
input in simulations was swept out using Latin hypercube sampling and
sensitivity analysis to model outputs was conducted using mixed effect models.
By exploring a large and computationally intensive parameter space we show that
of the available control strategies it is the frequency of TB testing and
whether or not winter housing is practised that have the most significant
effects on the number of infected cattle, with the effect of winter housing
becoming stronger as farm size increases. Whether badgers were culled or not
explained about 5%, while the accuracy of the test employed to detect infected
cattle explained less than 3% of the variance in the number of infected cattle
Cardiosphere-derived cells suppress allogeneic lymphocytes by production of PGE2 acting via the EP4 receptor
derived cells (CDCs) are a cardiac progenitor cell population, which have been shown to possess cardiac regenerative properties and can improve heart function in a variety of cardiac diseases. Studies in large animal models have predominantly focussed on using autologous cells for safety, however allogeneic cell banks would allow for a practical, cost-effective and efficient use in a clinical setting. The aim of this work was to determine the immunomodulatory status of these cells using CDCs and lymphocytes from 5 dogs. CDCs expressed MHC I but not MHC II molecules and in mixed lymphocyte reactions demonstrated a lack of lymphocyte proliferation in response to MHC-mismatched CDCs. Furthermore, MHC-mismatched CDCs suppressed lymphocyte proliferation and activation in response to Concanavalin A. Transwell experiments demonstrated that this was predominantly due
to direct cell-cell contact in addition to soluble mediators whereby CDCs produced high levels of PGE2
under inflammatory conditions. This led to down-regulation of CD25 expression on lymphocytes via the
EP4 receptor. Blocking prostaglandin synthesis restored both, proliferation and activation (measured via CD25 expression) of stimulated lymphocytes. We demonstrated for the first time in a large animal model that CDCs inhibit proliferation in allo-reactive lymphocytes and have potent immunosuppressive activity mediated via PGE2
Study of scattered radiation during fluoroscopy in hip surgery
Objetivo: Medir a intensidade da dose de radiação espalhada em diferentes posições simulando uma intervenção cirúrgica no quadril.
Materiais e Métodos: Simulou-se uma intervenção cirúrgica no quadril com apoio da fluoroscopia para estudar a distribuição da radiação
espalhada no bloco operatório. Para simular o paciente foi utilizado um simulador antropomórfico de corpo inteiro e para medir a radiação
utilizou-se um detector especÃfico para medir raios X. Realizaram-se incidências com um equipamento de raios X tipo arco em C móvel,
em modo de escopia contÃnua, com a ampola a 0° (configuração 1) e a 90° (configuração 2). Os parâmetros operacionais utilizados
(voltagem, corrente, tempo de exposição) foram determinados por meio de um estudo estatÃstico resultante da observação de cirurgias
ortopédicas de quadril.
Resultados: Em todas as medições observaram-se exposições mais elevadas na configuração 2. Nas medições em função da altura,
observaram-se os valores máximos da taxa de dose de 1,167 (± 0,023) µSv/s e 2,278 (± 0,023) µSv/s nas configurações 1 e 2,
respectivamente, correspondendo à altura do tórax dos profissionais. No estudo em torno do paciente os valores máximos registraramse
na posição ocupada pelo médico cirurgião.
Conclusão: Concluiu-se que a exposição à radiação dos profissionais é baixa, podendo ainda ser reduzida mediante o uso de equipamentos
de proteção individualObjective: To measure the scattered radiation dose at different positions simulating hip surgery.
Materials and Methods: We simulated fluoroscopy-assisted hip surgery in order to study the distribution of scattered radiation in the
operating room. To simulate the patient, we used a anthropomorphic whole-body phantom, and we used an X-ray-specific detector to
quantify the radiation. Radiographs were obtained with a mobile C-arm X-ray system in continuous scan mode, with the tube at 0°
(configuration 1) or 90° (configuration 2). The operating parameters employed (voltage, current, and exposure time) were determined by
a statistical analysis based on the observation of orthopedic surgical procedures involving the hip.
Results: For all measurements, higher exposures were observed in configuration 2. In the measurements obtained as a function of
height, the maximum dose rates observed were 1.167 (± 0.023) µSv/s and 2.278 (± 0.023) µSv/s in configurations 1 and 2, respectively,
corresponding to the chest level of health care professionals within the operating room. Proximal to the patient, the maximum values were
recorded in the position occupied by the surgeon.
Conclusion: We can conclude that, in the scenario under study, health care professionals workers are exposed to low levels of radiation,
and that those levels can be reduced through the use of personal protective equipmen
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Cross-cultural adaptation and clinical validation of the neonatal skin condition score to Brazilian Portuguese
Objective: to describe the process of cross-cultural adaptation and clinical validation of the Neonatal Skin Condition Score.
Methods: this methodological cross-cultural adaptation study included five steps: initial translation, synthesis of the initial translation, back translation, review by an Committee of Specialists and testing of the pre-final version, and an observational cross-sectional study with analysis of the psychometric properties using the Adjusted Kappa, Intraclass Correlation Coefficient, and Bland- Altman Method statistical tests. A total of 38 professionals were randomly recruited to review the clarity of the adapted instrument, and 47 newborns hospitalized in the Neonatology Unit of the Clinical Hospital of Porto Alegre were selected by convenience for the clinical validation of the instrument.
Results: the adapted scale showed approximately 85% clarity. The statistical tests showed moderate to strong intra and interobserver item to item reliability and from strong to very strong in the total score, with a variation of less than 2 points among the scores assigned by the nurses to the patients.
Conclusions: the scale was adapted and validated to Brazilian Portuguese. The psychometric properties of the Brazilian version of the Neonatal Skin Condition Score instrument were similar to the validation results of the original scale
AP2γ controls adult hippocampal neurogenesis and modulates cognitive, but not anxiety or depressive-like behavior
Hippocampal neurogenesis has been proposed to participate in a myriad of behavioral responses, both in basal states and in the context of neuropsychiatric disorders. Here, we identify activating protein 2γ 3 (AP2γ 3, also known as Tcfap2c), originally described to regulate the generation of neurons in the developing cortex, as a modulator of adult hippocampal glutamatergic neurogenesis in mice. Specifically, AP2γ 3 is present in a sub-population of hippocampal transient amplifying progenitors. There, it is found to act as a positive regulator of the cell fate determinants Tbr2 and NeuroD, promoting proliferation and differentiation of new glutamatergic granular neurons. Conditional ablation of AP2γ 3 in the adult brain significantly reduced hippocampal neurogenesis and disrupted neural coherence between the ventral hippocampus and the medial prefrontal cortex. Furthermore, it resulted in the precipitation of multimodal cognitive deficits. This indicates that the sub-population of AP2γ 3-positive hippocampal progenitors may constitute an important cellular substrate for hippocampal-dependent cognitive functions. Concurrently, AP2γ 3 deletion produced significant impairments in contextual memory and reversal learning. More so, in a water maze reference memory task a delay in the transition to cognitive strategies relying on hippocampal function integrity was observed. Interestingly, anxiety- and d epressive-like behaviors were not significantly affected. Altogether, findings open new perspectives in understanding the role of specific sub-populations of newborn neurons in the (patho)physiology of neuropsychiatric disorders affecting hippocampal neuroplasticity and cognitive function in the adult brain.We acknowledge the excellent technical expertise of LuÃs Martins and Andrea
Steiner-Mezzadri. We would also like to acknowledge Magdalena Götz for the
insightful comments on the paper. AMP, PP, ARS, JS, VMS, NDA and JFO received
fellowships from the Portuguese Foundation for Science and Technology (FCT). LP
received fellowship from FCT and her work is funded by FCT (IF/01079/2014) and Bial
Foundation (427/14) projects. This work was cofunded by the Life and Health
Sciences Research Institute (ICVS), and Northern Portugal Regional Operational
Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through
the European Regional Development Fund (FEDER) (projects NORTE-01-0145-
FEDER-000013 and NORTE-01-0145-FEDER-000023). This work has been also funded
by FEDER funds, through the Competitiveness Factors Operational Programme
(COMPETE), and by National funds, through the FCT, under the scope of the project
POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio
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