833 research outputs found
Real-Time Adaptive Event Detection in Astronomical Data Streams
A new generation of observational science instruments is dramatically increasing collected data volumes in a range of fields. These instruments include the Square Kilometer Array (SKA), Large Synoptic Survey Telescope (LSST), terrestrial sensor networks, and NASA satellites participating in "decadal survey"' missions. Their unprecedented coverage and sensitivity will likely reveal wholly new categories of unexpected and transient events. Commensal methods passively analyze these data streams, recognizing anomalous events of scientific interest and reacting in real time. Here, the authors report on a case example: Very Long Baseline Array Fast Transients Experiment (V-FASTR), an ongoing commensal experiment at the Very Long Baseline Array (VLBA) that uses online adaptive pattern recognition to search for anomalous fast radio transients. V-FASTR triages a millisecond-resolution stream of data and promotes candidate anomalies for further offline analysis. It tunes detection parameters in real time, injecting synthetic events to continually retrain itself for optimum performance. This self-tuning approach retains sensitivity to weak signals while adapting to changing instrument configurations and noise conditions. The system has operated since July 2011, making it the longest-running real-time commensal radio transient experiment to date
Detection of fast radio transients with multiple stations: a case study using the Very Long Baseline Array
Recent investigations reveal an important new class of transient radio
phenomena that occur on sub-millisecond timescales. Often transient surveys'
data volumes are too large to archive exhaustively. Instead, an on-line
automatic system must excise impulsive interference and detect candidate events
in real-time. This work presents a case study using data from multiple
geographically distributed stations to perform simultaneous interference
excision and transient detection. We present several algorithms that
incorporate dedispersed data from multiple sites, and report experiments with a
commensal real-time transient detection system on the Very Long Baseline Array
(VLBA). We test the system using observations of pulsar B0329+54. The
multiple-station algorithms enhanced sensitivity for detection of individual
pulses. These strategies could improve detection performance for a future
generation of geographically distributed arrays such as the Australian Square
Kilometre Array Pathfinder and the Square Kilometre Array.Comment: 12 pages, 14 figures. Accepted for Ap
Evaluation of a pilot cooperative medical scheme in rural China: impact on gender patterns of health care utilization and prescription practices
<p>Abstract</p> <p>Background</p> <p>In 2003 the Chinese government introduced voluntary cooperative medical schemes (CMS), soon to be in place throughout rural China. Families who chose to enroll do so as a single unit and nothing is known about any differential effect of these new schemes on family members. This study evaluates the impact of one pilot CMS in Anhui Province on health care use by girls aged less than 5 years and women 65 years or older, and on the pattern and cost of prescriptions.</p> <p>Methods</p> <p>Health care records were extracted covering a 10 year period, before, during and after the pilot CMS in 4 townships, one with the intervention and 3 comparison townships without. The impact of the intervention on the age and gender distribution of patients presenting for health care and on the prescription of certain drugs was assessed by logistic regression. The cost of prescriptions before, during and after the intervention period was also assessed.</p> <p>Results</p> <p>203,058 registration and 643,588 prescription records were identified. During the intervention there was a reduced likelihood overall that a patient was female (OR = 0.92: 95%CI 0.87 - 0.97) at the intervention site. Girls aged < 5 years had an increased likelihood of health care (OR = 1.41: 95%CI 1.23 - 1.59) during the CMS, but women ≥ 65 years were relatively disadvantaged (OR = 0.84: 95%CI 0.75 - 0.95). The use of antibiotics and systemic steroids increased disproportionately at the intervention site for patients ≥ 5 years. Prescription costs at the township hospital also increased at the intervention site, particularly for older men.</p> <p>Conclusions</p> <p>This evaluation suggests that all family members did not benefit equally from the pilot CMS and that women ≥ 65 years may be disadvantaged by the newly available reimbursements of health care costs through the CMS. It points to the need, in future evaluations, to use individuals rather than families as the unit of analysis, in order to determine whether such health care inequalities are wide-spread and persistent or are reduced in the longer term. The results also support earlier concerns about the influence of new funding resources on prescription practices and the need for regulation of for-profit prescribing.</p
The Commensal Real-time ASKAP Fast Transients (CRAFT) survey
We are developing a purely commensal survey experiment for fast (<5s)
transient radio sources. Short-timescale transients are associated with the
most energetic and brightest single events in the Universe. Our objective is to
cover the enormous volume of transients parameter space made available by
ASKAP, with an unprecedented combination of sensitivity and field of view. Fast
timescale transients open new vistas on the physics of high brightness
temperature emission, extreme states of matter and the physics of strong
gravitational fields. In addition, the detection of extragalactic objects
affords us an entirely new and extremely sensitive probe on the huge reservoir
of baryons present in the IGM. We outline here our approach to the considerable
challenge involved in detecting fast transients, particularly the development
of hardware fast enough to dedisperse and search the ASKAP data stream at or
near real-time rates. Through CRAFT, ASKAP will provide the testbed of many of
the key technologies and survey modes proposed for high time resolution science
with the SKA.Comment: accepted for publication in PAS
Noether Symmetry Approach in "Cosmic Triad" Vector Field Scenario
To realize the accelerations in the early and late periods of our universe,
we need to specify potentials for the dominant fields. In this paper, by using
the Noether symmetry approach, we try to find suitable potentials in the
"cosmic triad" vector field scenario. Because the equation of state parameter
of dark energy has been constrained in the range of by observations, we derive the Noether conditions for the vector field
in quintessence, phantom and quintom models, respectively. In the first two
cases, constant potential solutions have been obtained. What is more, a fast
decaying point-like solution with power-law potential is also found for the
vector field in quintessence model. For the quintom case, we find an
interesting constraint on the field potentials,
where and are constants related to the Noether symmetry.Comment: 15 pages, no figures, accepted by Classical and Quantum Gravity
Cosmology of a Scalar Field Coupled to Matter and an Isotropy-Violating Maxwell Field
Motivated by the couplings of the dilaton in four-dimensional effective
actions, we investigate the cosmological consequences of a scalar field coupled
both to matter and a Maxwell-type vector field. The vector field has a
background isotropy-violating component. New anisotropic scaling solutions
which can be responsible for the matter and dark energy dominated epochs are
identified and explored. For a large parameter region the universe expands
almost isotropically. Using that the CMB quadrupole is extremely sensitive to
shear, we constrain the ratio of the matter coupling to the vector coupling to
be less than 10^(-5). Moreover, we identify a large parameter region,
corresponding to a strong vector coupling regime, yielding exciting and viable
cosmologies close to the LCDM limit.Comment: Refs. added, some clarifications. Published in JHEP10(2012)06
The Development and Initial Validation of a Measure of Coaching Behaviors in a Sample of Soldiers Under Training
In this article we outline a model of coaching that is conceptually grounded in workplace and sport coaching literature and present 2 studies conducted to test this model: the extent that coaching behaviors are present in a military training setting, and their association with performance-related outcomes. Following an extensive review of literature and rigorous development and validation procedures the 28-item Military Coaching Behavior Scale was tested. The measure showed good content and predictive validity for 2 dependent variables (satisfaction and resilience). We concluded that the Military Coaching Behavior Scale offers a psychometrically sound, brief, and easy-to-administer measure of high-performance coaching behavior
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Enhancement of glucosinolate and isothiocyanate profiles in brassicaceae crops: addressing challenges in breeding for cultivation, storage, and consumer-related traits
Glucosinolates (GSLs) and isothiocyanates (ITCs) produced by Brassicaceae plants are popular targets for analysis due to the health benefits associated with them. Breeders aim to increase the concentrations in commercial varieties; however, there are few examples of this. The most well-known is Beneforté broccoli, which has increased glucoraphanin/ sulforaphane concentrations compared to those of conventional varieties. It was developed through traditional breeding methods with considerations for processing, consumption, and health made throughout this process. Many studies presented in the literature do not take a holistic approach, and key points about breeding, cultivation methods, postharvest storage, sensory attributes, and consumer preferences are not properly taken into account. In this review, we draw together data for multiple species and address how such factors can influence GSL profiles. We encourage researchers and institutions to engage with industry and consumers to produce research that can be utilized in the improvement of Brassicaceae crops
Social and ethical criteria for prioritizing patients: a survey of students and health professionals in Portugal
O estudo quali-quantitativo explora
o dilema ético da microalocação dos recursos da
saúde. Objetiva identificar e comparar a opinião
de dois grupos da sociedade portuguesa - estudantes
e profissionais de saúde sobre a importância
das características pessoais dos pacientes no momento
de os priorizar e se as escolhas se explicam
por referenciais bioéticos de caráter utilitaristas ou
deontológicos. Os dados foram recolhidos através
de um questionário aplicado a uma amostra de
180 estudantes universitários e 60 profissionais de
saúde. Os respondentes perante hipotéticos cená-
rios de emergência clínica tiveram de escolher de
entre dois pacientes (distinguidos por idade, sexo,
responsabilidade social, situação económica e laboral,
comportamentos lesivos da saúde e registo
criminal) quem tratar e justificar a escolha. Foram
usados testes estatísticos de associação para
comparar as respostas dos dois grupos e análise
de conteúdo para categorizar as justificações. Os
resultados sugerem a existência de diferenças nas
escolhas dos dois grupos, com os profissionais de
saúde a revelarem aceitar menos a utilização de
critérios sociais em contexto de escassez e coexistência
de critérios utilitaristas e deontológicos,
com predomínio da eficiência por parte dos profissionais
de saúde e da equidade por parte dos
estudantesThis qualitative/quantitative study examines
the ethical dilemma of microallocation of
health resources. It seeks to identify and compare
the opinion of two groups in Portuguese society
– students and health professionals – on the importance
of personal characteristics of patients at
the moment of prioritizing them and if the choices
can be explained by bioethical references of a
utilitarian or deontological nature. Data were
collected by means of a questionnaire administered
to a sample of 180 students and 60 health
professionals. Faced with hypothetical emergency
scenarios, the respondents had to choose between
two patients (distinguished by: age, gender, social
responsibility, economic and employment
situation, harmful health behaviors and criminal
record), duly selecting who to treat and then
justifying their choice. The results suggest the existence
of differences in choices between the two
groups, with health professionals revealing they
are less prepared to accept the use of social criteria
in a context of scarce resources and co-existence
of utilitarian and deontological criteria, with a
predominance of efficiency on the part of health
professionals and equity on the part of students.info:eu-repo/semantics/publishedVersio
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