438 research outputs found
SELF-REPORTED ADHERENCE TO PHYSICAL ACTIVITY FOR CANCER SURVIVORS: AN UPDATE FROM THE 2015 NHIS DATABASE
Cancer is the second leading cause of death in America. It’s been suggested that regular physical activity (PA) can improve health outcomes in cancer survivors. An estimate from BRFSS data (2009) suggested that 47% of all cancer survivors met recommended guidelines and that this estimate was not different from the population at large (48%). Several factors were examined from these BRFSS data to determine whether subgroups of survivors existed who might benefit from interventions aimed at improving their PA status. The purpose of this investigation was to obtain more recent estimates of adherence to established PA guidelines for cancer survivors. Data from 2015 NHIS were obtained from the CDC website. Of the survivors, 40% met PA guidelines. Additionally, 79% were 54 years or older, more likely to be female (60%), predominantly white (80%), with more than 2 comorbidities (41%), and with some form of functional limitation (66%). Compared to a study based on 2009 BRFSS data, an even smaller proportion of survivors met PA guidelines in this study. This might be due to differences in age distributions and no limitation of the analysis according to time since diagnosis. Targeted interventions to increase activity in cancer survivors continue to be warranted
An investigation of the Eigenvalue Calibration Method (ECM) using GASP for non-imaging and imaging detectors
Polarised light from astronomical targets can yield a wealth of information
about their source radiation mechanisms, and about the geometry of the
scattered light regions. Optical observations, of both the linear and circular
polarisation components, have been impeded due to non-optimised
instrumentation. The need for suitable observing conditions and the
availability of luminous targets are also limiting factors. GASP uses division
of amplitude polarimeter (DOAP) (Compain and Drevillon) to measure the four
components of the Stokes vector simultaneously, which eliminates the
constraints placed upon the need for moving parts during observation, and
offers a real-time complete measurement of polarisation. Results from the GASP
calibration are presented in this work for both a 1D detector system, and a
pixel-by-pixel analysis on a 2D detector system. Following Compain et al. we
use the Eigenvalue Calibration Method (ECM) to measure the polarimetric
limitations of the instrument for each of the two systems. Consequently, the
ECM is able to compensate for systematic errors introduced by the calibration
optics, and it also accounts for all optical elements of the polarimeter in the
output. Initial laboratory results of the ECM are presented, using APD
detectors, where errors of 0.2% and 0.1{\deg} were measured for the degree of
linear polarisation and polarisation angle respectively. Channel-to-channel
image registration is an important aspect of 2-D polarimetry. We present our
calibration results of the measured Mueller matrix of each sample, used by the
ECM. A set of Zenith flat-field images were recorded during an observing
campaign at the Palomar 200 inch telescope in November 2012. From these we show
the polarimetric errors from the spatial polarimetry indicating both the
stability and absolute accuracy of GASP.Comment: Accepted for publication in Experimental Astronom
Employing pre-stress to generate finite cloaks for antiplane elastic waves
It is shown that nonlinear elastic pre-stress of neo-Hookean hyperelastic
materials can be used as a mechanism to generate finite cloaks and thus render
objects near-invisible to incoming antiplane elastic waves. This approach
appears to negate the requirement for special cloaking metamaterials with
inhomogeneous and anisotropic material properties in this case. These
properties are induced naturally by virtue of the pre-stress. This appears to
provide a mechanism for broadband cloaking since dispersive effects due to
metamaterial microstructure will not arise.Comment: 4 pages, 2 figure
Kinematics of the Broad Line Region in M81
A new model is presented which explains the origin of the broad emission
lines observed in the LINER/Seyfert nucleus of M81 in terms of a steady state
spherically symmetric inflow, amounting to 1 x 10^-5 Msun/yr, which is
sufficient to explain the luminosity of the AGN. The emitting volume has an
outer radius of ~1 pc, making it the largest broad line region yet to be
measured, and it contains a total mass of ~ 5 x 10^-2 Msun of dense, ~ 10^8
cm^-3, ionized gas, leading to a very low filling factor of ~ 5 x 10^-9. The
fact that the BLR in M81 is so large may explain why the AGN is unable to
sustain the ionization seen there. Thus, the AGN in M81 is not simply a scaled
down quasar.Comment: Accepted for Publication in ApJ 7/21/0
Flow Dependent Evaluation and Training of Random Forest based Probabilistic Forecasts of Severe Weather Hazards
There has been an increasing interest over the past ten years in the use of Machine Learning (ML) algorithms such as Random Forests (RF) in the context of severe weather prediction. RF-based methods have even been shown to outperform human-generated operational convective outlook guidance in some cases. However, there remain obstacles to fully integrating the ML algorithms into the operational forecasting process of severe wind, hail and tornado events. For example, the perceived black-box nature of complex RF models can inhibit forecaster confidence in the ML guidance for high impact or atypical events. Since the error characteristics of predictors based on numerical weather prediction, or NWP, and the relationships between these predictors and severe weather risk can vary in different flow patterns, there is a need to better understand the impacts of large-scale flow patterns on RF model performance. In addition to improving confidence in the RF-based forecast products, such understanding can also be incorporated into the model building process to further improve their performance.
This thesis discusses the development and evaluation of a flow-dependent approach to training RF models to produce severe weather convective outlook guidance. This work leverages 53 real-time cases from the 2019 and 2021 real time convection-allowing FV3-based ensemble forecasts produced by the University of Oklahoma (OU) Multi-scale data Assimilation and Predictability (MAP) Lab during the 2021 Hazardous Weather Testbed (HWT) forecasting experiments as model predictors. This study will focus mainly on the 29 cases from 2021. As a first step, the composite difference in large-scale flow between cases with relatively high and low importance of key predictors using Permutation Feature Importance were calculated. These composite differences were used to evaluate if discernible large scale flow patterns could be when the non-flow dependent model would perform the best. Two different methods of classifying cases based on the large-scale flow patterns are then evaluated for the purpose of training separate RF models on cases of similar flow patterns. The appropriate RF model for the pattern is then used to generating convective outlook guidance for a forecast case not included in the RF model training. First, the CAPE/shear parameter space over the region of interest is used as a classification metric. Second, EOF patterns that are qualitatively similar to the previously described composite flow patterns related to predictor importance and used as the classification metric. Finally, both methods will check how sensitive the performance is to changes in sample size by adding the 2019 cases. Both flow-dependent training methods will be compared to the non-flow dependent models and compared to each other. Results will emphasize both objective impacts on forecast skill and physical explanations of the difference in performance among the RF training approaches. Results show that both methods of flow-dependent training initially show improvement in forecasting severe weather compared to the non-flow dependent model. However, the parameter space classification remain to show significant skill with an increase in sample size while not all EOF patterns skill remained significant
The measurement of collective efficacy and its manipulation through imagery.
Previous investigations of collective efficacy have lacked consistency in the way in which it has been conceptualised, operationalised, measured, and analysed. In addition; limited research has considered how collective efficacy might be manipulated to improve overall team performance. The broad aim of this thesis therefore, was to advance the understanding of collective efficacy measurement and its application in sport psychology. In chapter three, two separate studies were conducted to design and preliminarily validate a collective efficacy inventory for sport. Confirmatory factor analysis was used in the first study to assess the factorial validity of a pool of 18-items, and indicated that either a 10-item single-factor model or two 5-item models provided the closest fit to the conceptual model. In the second study, data collected using the 10 remaining items revealed both the 10-item and two five-item models had robust construct and criterion validity when correlated with three other theoretically related inventories. However, the two five-item models were highly correlated, indicating they measured the same construct. Therefore, given that longer inventories have greater internal reliability, the 10-item model was adopted as a measure of collective efficacy (Collective Efficacy Inventory; CEI) for the remainder of the thesis. The remaining experimental chapters of the thesis considered the psychological strategies appropriate for the manipulation of collective efficacy. Of the four basic psychological skills, imagery was proposed to have the strongest conceptual link with collective efficacy. Therefore, chapter four examined the relationship between different imagery types and individual perceptions of collective efficacy as a function of skill. Motivational general- mastery (MG-M) type imagery significantly predicted collective efficacy scores for the elite sample, indicating that MG-M type imagery was a suitable intervention for improving levels of collective efficacy. In chapter five, a multiple baseline across-groups design was then used to examine the effects of an MG-M type imagery intervention on perceptions of collective efficacy. Collective efficacy increased for the first group, became more consistent for the second, and did not change for the final group. Lower levels of intra-group variability were reported for all groups following the introduction of the intervention. The findings provided partial support for the use of MG-M type imagery interventions to enhance collective efficacy in an elite sports team. The overall findings of this thesis have increased understanding of the measurement of collective efficacy and its manipulation using imagery interventions. Practical recommendations are suggested for how the CEI can be used to monitor the effects of an imagery intervention on collective efficacy, and specific design implications for the delivery of the intervention to team sports
Photon Correlation Spectroscopy for Observing Natural Lasers
Natural laser emission may be produced whenever suitable atomic energy levels
become overpopulated. Strong evidence for laser emission exists in astronomical
sources such as Eta Carinae, and other luminous stars. However, the evidence is
indirect in that the laser lines have not yet been spectrally resolved. The
lines are theoretically estimated to be extremely narrow, requiring spectral
resolutions very much higher (R approx.= 10**8) than possible with ordinary
spectroscopy. Such can be attained with photon-correlation spectroscopy on
nanosecond timescales, measuring the autocorrelation function of photon arrival
times to obtain the coherence time of light, and thus the spectral linewidth. A
particular advantage is the insensitivity to spectral, spatial, and temporal
shifts of emission-line components due to local velocities and probable
variability of 'hot-spots' in the source. A laboratory experiment has been set
up, simulating telescopic observations of cosmic laser emission. Numerically
simulated observations estimate how laser emission components within realistic
spectral and spatial passbands for various candidate sources carry over to
observable statistical functions.Comment: Paper presented at the conference 'High Time Resolution
Astrophysics', held in Edinburgh, Scotland, September 2007. To appear in
D.Phelan, O.Ryan & A.Shearer, eds.,'The Universe at sub-second timescales',
AIP Conf.Proc., in press, 2008 (American Institute of Physics,
http://www.aip.org/proceedings). 9 pages, 3 figures, 36 reference
HIV-1 pathogenesis: IFN-alpha-dependent and -independent mechanisms of T cell death and unresponsiveness
Saiu o dinheiro do coco?: avaliação de processo da política de garantia de preços mínimos para os produtos da sociobiodiversidade (PGPM-Bio) para a amêndoa do babaçu no Médio Mearim, Maranhão.
O objetivo central desta dissertação foi avaliar a eficácia da implementação da Política de Garantia de Preços Mínimos para Produtos da Sociobiodiversidade (PGPM-Bio) e seus efeitos na organização social das quebradeiras de coco babaçu no Médio Mearim, Maranhão, onde ocorre cerca de um terço da produção nacional de amêndoas. Passada uma década da criação da política pública, os atores sociais engajados no extrativismo demandam estudos sobre a eficácia de sua implementação. No período 2009-2018, 48% dos recursos da PGPM-Bio foram destinados para amêndoas de babaçu. A metodologia de pesquisa-ação proporcionou o envolvimento de instituições de representação e assessoria e a manifestação dos sujeitos sociais locais sobre os cenários de implementação da PGPM-Bio. A necessidade do envolvimento daqueles que viabilizam o acesso das quebradeiras de coco à PGPM-Bio (agentes mediadores) e das beneficiárias diretas levou à adoção de ferramentas participativas de fácil compreensão e assimilação. Os resultados obtidos incluem a identificação e análise da atuação de oito categorias de agentes mediadores, vinculados a organizações formais (sindicato, associação, cooperativa, Miqcb, órgãos governamentais) ou não (grupo informal, despachante autônomo, comerciante), sendo selecionadas 14 iniciativas em 10 municípios. As informações qualitativas a partir das experiências vividas pelos agentes mediadores receberam tratamento quantitativo por meio do gráfico radar de competência. Mais de 240 quebradeiras de coco babaçu beneficiárias participaram das atividades coletivas e narraram suas percepções sobre o efeito do acesso à subvenção econômica, no período de 2016 a 2018. As informações quantitativas foram analisadas a partir do gráfico radar comunitário. A triangulação das informações destacou potencialidades e limitações da política, dos agentes mediadores, e das organizações sociais envolvidas. Os resultados destacam a amplitude do acesso ao recurso e a heterogeneidade quanto às formas de apropriação, autonomia decisória e estratégias gerenciais. A avaliação evidenciou que as iniciativas conduzidas por Sindicatos de Trabalhadores Rurais apresentaram maior grau de eficácia, contrastando com aquelas de grupos informais, da cooperativa e despachante autônomo, que resultaram menos eficazes e demandam esforços adicionais. A pesquisa contribuiu para a estratégia organizativa dos grupos, que passaram a pensar e agir em redes de apoio e parceria, por meio da Comissão da PGPM-Bio no Médio Mearim.bitstream/item/225057/1/DISSERTAC807A771O-VERSA771O-FINAL-LETI769CIA-SALES-CD.pdfDissertação (Mestrado em Agricultura Familiar e Desenvolvimento Sustentável) - Universidade Federal do Pará; Embrapa Amazônia Oriental, Belém, PA. Orientador: Roberto Porro, CPATU
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