1,129 research outputs found
Conductors and newforms for U(1,1)
Let be a non-Archimedean local field whose residue characteristic is odd.
In this paper we develop a theory of newforms for , building on
previous work on . This theory is analogous to the results of
Casselman for and Jacquet, Piatetski-Shapiro, and Shalika for
. To a representation of , we attach an integer
called the conductor of , which depends only on the -packet
containing . A newform is a vector in which is essentially
fixed by a congruence subgroup of level . We show that our newforms are
always test vectors for some standard Whittaker functionals, and, in doing so,
we give various explicit formulae for newforms.Comment: 25 page
Reasoning and planning in dynamic domains: An experiment with a mobile robot
Progress made toward having an autonomous mobile robot reason and plan complex tasks in real-world environments is described. To cope with the dynamic and uncertain nature of the world, researchers use a highly reactive system to which is attributed attitudes of belief, desire, and intention. Because these attitudes are explicitly represented, they can be manipulated and reasoned about, resulting in complex goal-directed and reflective behaviors. Unlike most planning systems, the plans or intentions formed by the system need only be partly elaborated before it decides to act. This allows the system to avoid overly strong expectations about the environment, overly constrained plans of action, and other forms of over-commitment common to previous planners. In addition, the system is continuously reactive and has the ability to change its goals and intentions as situations warrant. Thus, while the system architecture allows for reasoning about means and ends in much the same way as traditional planners, it also posseses the reactivity required for survival in complex real-world domains. The system was tested using SRI's autonomous robot (Flakey) in a scenario involving navigation and the performance of an emergency task in a space station scenario
Phase locking below rate threshold in noisy model neurons
The property of a neuron to phase-lock to an oscillatory stimulus before adapting its spike rate to the stimulus frequency plays an important role for the auditory system. We investigate under which conditions neurons exhibit this phase locking below rate threshold. To this end, we simulate neurons employing the widely used leaky integrate-and-fire (LIF) model. Tuning parameters, we can arrange either an irregular spontaneous or a tonic spiking mode. When the neuron is stimulated in both modes, a significant rise of vector strength prior to a noticeable change of the spike rate can be observed. Combining analytic reasoning with numerical simulations, we trace this observation back to a modulation of interspike intervals, which itself requires spikes to be only loosely coupled. We test the limits of this conception by simulating an LIF model with threshold fatigue, which generates pronounced anticorrelations between subsequent interspike intervals. In addition we evaluate the LIF response for harmonic stimuli of various frequencies and discuss the extension to more complex stimuli. It seems that phase locking below rate threshold occurs generically for all zero mean stimuli. Finally, we discuss our findings in the context of stimulus detection
Challenges in cardiac device innovation: is neuroimaging an appropriate endpoint? Consensus from the 2013 Yale-UCL Cardiac Device Innovation Summit
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The Clinical Utility of a Precision Medicine Blood Test Incorporating Age, Sex, and Gene Expression for Evaluating Women with Stable Symptoms Suggestive of Obstructive Coronary Artery Disease: Analysis from the PRESET Registry.
Background: Evaluating women with symptoms suggestive of coronary artery disease (CAD) remains challenging. A blood-based precision medicine test yielding an age/sex/gene expression score (ASGES) has shown clinical validity in the diagnosis of obstructive CAD. We assessed the effect of the ASGES on the management of women with suspected obstructive CAD in a community-based registry. Materials and Methods: The prospective PRESET (A Registry to Evaluate Patterns of Care Associated with the Use of CorusÂź CAD in Real World Clinical Care Settings) Registry (NCT01677156) enrolled 566 patients presenting with symptoms suggestive of stable obstructive CAD from 21 United States primary care practices from 2012 to 2014. Demographics, clinical characteristics, and referrals to cardiology or further functional and/or anatomical cardiac studies after ASGES testing were collected for this subgroup analysis of women from the PRESET Registry. Patients were followed for 1-year post-ASGES testing. Results: This study cohort included 288 women with a median age 57 years. The median body mass index was 29.2, with hyperlipidemia and hypertension present in 48% and 43% of patients, respectively. Median ASGES was 8.5 (range 1-40), with 218 (76%) patients having low (â€15) ASGES. Clinicians referred 9% (20/218) low ASGES versus 44% (31/70) elevated ASGES women for further cardiac evaluation (odds ratio 0.14, pâ<â0.0001, adjusted for patient demographics and clinical covariates). Across the score range, higher ASGES were associated with a higher likelihood of posttest cardiac referral. At 1-year follow-up, low ASGES women experienced fewer major adverse cardiac events than elevated ASGES women (1.3% vs. 4.2% respectively, pâ=â0.16). Conclusions: Incorporation of ASGES into the diagnostic workup demonstrated clinical utility by helping clinicians identify women less likely to benefit from further cardiac evaluation
SaĂșde Brasil 2011 : uma anĂĄlise da situação de saĂșde e a vigilĂąncia da saĂșde da mulher
Introdução: No Brasil, ocorrem cerca de 3 milhĂ”es de nascimentos ao ano, sendo grande parte deles por meio de cesarianas. Entender como se distribui esse procedimento no PaĂs Ă© relevante para a reflexĂŁo sobre o papel das polĂticas pĂșblicas nesse contexto. Objetivos: a) Descrever: magnitude e tendĂȘncia da taxa de cesĂĄreas*1 no PaĂs; morbimortalidade materna e neonatal associada a tipo de parto; e caracterĂsticas dos hospitais; b) analisar o preenchimento das variĂĄveis da nova versĂŁo da Declaração de Nascido Vivo (DNV) que permitirĂŁo monitoramento das indicaçÔes de cesĂĄrea; c) descrever as respostas institucionais para o enfrentamento do problema. MĂ©todos: Estudo descritivo de sĂ©rie histĂłrica da taxa de cesarianas, no PaĂs e macrorregiĂ”es, segundo caracterĂsticas sociodemogrĂĄficas, morbimortalidade e tipo de provedor, com fonte em bancos de dados oficiais. Analisou-se a completitude de variĂĄveis da versĂŁo da DNV de 2010 para monitoramento das indicaçÔes de cirurgia. Foram pesquisados documentos oficiais, visando identificar iniciativas para qualificar a atenção a partos e nascimentos e reduzir cesarianas desnecessĂĄrias. Resultados: A taxa de cesarianas foi de 32%, em 1994, e de 52%, em 2010, sendo menor no Norte e Nordeste. Mulheres submetidas a cesĂĄreas tiveram 3,5 vezes mais probabilidade de morrer (entre 1992â2010) e 5 vezes mais de ter infecção puerperal (entre 2000â2011) que as de parto normal. No perĂodo, a proporção de prematuros se elevou, mais nas cesĂĄreas (7,8%, sendo 6,4% nos partos normais em 2010). Em 2010, hospitais nĂŁo pĂșblicos apresentaram taxas maiores (63,6%) e maior aumento no perĂodo de 2006 a 2010 (14,0%); para os pĂșblicos, as taxas foram de 47,8% (federais), de 39,6% (estaduais) e de 34,0% (municipais). ConclusĂŁo: A cesariana Ă© frequente e sua proporção ascende no PaĂs, sendo muito elevada no setor de SaĂșde Suplementar. Para reverter essa tendĂȘncia, serĂŁo necessĂĄrias vĂĄrias medidas, incluindo a qualificação da informação para monitorar a efetividade das medidas propostas
Motoneuron membrane potentials follow a time inhomogeneous jump diffusion process
Stochastic leaky integrate-and-fire models are popular due to their simplicity and statistical tractability. They have been widely applied to gain understanding of the underlying mechanisms for spike timing in neurons, and have served as building blocks for more elaborate models. Especially the OrnsteinâUhlenbeck process is popular to describe the stochastic fluctuations in the membrane potential of a neuron, but also other models like the square-root model or models with a non-linear drift are sometimes applied. Data that can be described by such models have to be stationary and thus, the simple models can only be applied over short time windows. However, experimental data show varying time constants, state dependent noise, a graded firing threshold and time-inhomogeneous input. In the present study we build a jump diffusion model that incorporates these features, and introduce a firing mechanism with a state dependent intensity. In addition, we suggest statistical methods to estimate all unknown quantities and apply these to analyze turtle motoneuron membrane potentials. Finally, simulated and real data are compared and discussed. We find that a square-root diffusion describes the data much better than an OrnsteinâUhlenbeck process with constant diffusion coefficient. Further, the membrane time constant decreases with increasing depolarization, as expected from the increase in synaptic conductance. The network activity, which the neuron is exposed to, can be reasonably estimated to be a threshold version of the nerve output from the network. Moreover, the spiking characteristics are well described by a Poisson spike train with an intensity depending exponentially on the membrane potential
A comparison of the long AVE microâą Stent II and the Palmaz-Schatz stent: a SMART trial registry
Confronting system barriers for ST- elevation MI in low and middle income countries with a focus on India
© 2017 Our previous research found seven specific factors that cause system delays in ST-elevation Myocardial infarction management in developing countries. These delays, in conjunction with a lack of organized STEMI systems of care, result in inefficient processes to treat AMI in developing countries. In our present opinion paper, we have specifically explored the three most pertinent causes that afflict the seven specific factors responsible for system delays. In doing so, we incorporated a unique strategy of global STEMI expertise. With this methodology, the recommendations were provided by expert Indian cardiologist and final guidelines were drafted after comprehensive discussions by the entire group of submitting authors. We expect these recommendations to be utilitarian in improving STEMI care in developing countries
Wage losses in the year after breast cancer: Extent and determinants among Canadian women
This article is available open access through the publisherâs website at the link below. © The Author 2008.Background - Wage losses after breast cancer may result in considerable financial burden. Their assessment is made more urgent because more women now participate in the workforce and because breast cancer is managed using multiple treatment modalities that could lead to long work absences. We evaluated wage losses, their determinants, and the associations between wage losses and changes for the worse in the family's financial situation among Canadian women over the first 12 months after diagnosis of early breast cancer.
Methods - We conducted a prospective cohort study among women with breast cancer from eight hospitals throughout the province of Quebec. Information that permitted the calculation of wage losses and information on potential determinants of wage losses were collected by three pretested telephone interviews conducted over the year following the start of treatment. Information on medical characteristics was obtained from medical records. The main outcome was the proportion of annual wages lost because of breast cancer. Multivariable analysis of variance using the general linear model was used to identify personal, medical, and employment characteristics associated with the proportion of wages lost. All statistical tests were two-sided.
Results - Among 962 eligible breast cancer patients, 800 completed all three interviews. Of these, 459 had a paying job during the month before diagnosis. On average, these working women lost 27% of their projected usual annual wages (median = 19%) after compensation received had been taken into account. Multivariable analysis showed that a higher percentage of lost wages was statistically significantly associated with a lower level of education (Ptrend = .0018), living 50 km or more from the hospital where surgery was performed (P = .070), lower social support (P = .012), having invasive disease (P = .086), receipt of chemotherapy (P < .001), self-employment (P < .001), shorter tenure in the job (Ptrend < .001), and part-time work (P < .001).
Conclusion - Wage losses and their effects on financial situation constitute an important adverse consequence of breast cancer in Canada.The Canadian Breast Cancer Research Alliance, Canadian
Institutes of Health Research, and Fondation de lâUniversitĂ© Laval
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