12,977 research outputs found
A Novel Approach to Recreational Reading: Creating a Virtual Collection on a Shoestring
Reading for recreation has been tied to academic achievement and lifelong learning, but not all academic libraries have the capacity to offer a separate recreational reading collection for their users. A low/no-cost option is to create a virtual recreational reading collection that allows patrons to browse for print titles by genre or book cover, much as they would in a bookstore or physical collection. The authors recently implemented this solution at their institution by dynamically compiling records of existing titles belonging to genres that are often of interest to recreational readers. This article addresses the justification for investing staff time in promoting recreational reading, discusses the technology employed to create and maintain a virtual collection, and shares the impacts of this effort on circulation
Searching for Planets in the Hyades. I. The Keck Radial Velocity Survey
We describe a high-precision radial velocity search for jovian-mass
companions to main sequence stars in the Hyades star cluster. The Hyades
provides an extremely well controlled sample of stars of the same age, the same
metallicity, and a common birth and early dynamical environment. This sample
allows us to explore the dependence of the process of planet formation on only
a single independent variable: the stellar mass. In this paper we describe the
survey and summarize results for the first five years.Comment: 8 pages, 3 figures; To appear in the July 2002 issue of The
Astronomical Journa
Efficacy of a self-help manual in increasing resilience in carers of adults with depression in Thailand
Caring for a person with a mental illness can have adverse effects on caregivers; however, little is known about how best to help such caregivers. The aim of the present study was to examine the efficacy of a cognitive behaviour therapy-guided self-help manual in increasing resilience in caregivers of individuals with depression, in comparison to caregivers who receive routine support only. A randomized, controlled trial was conducted, following CONSORT guidelines, with 54 caregivers allocated to parallel intervention (self-help manual) (n = 27) or control (standard support) (n = 27) groups. Resilience was assessed at baseline, post-test (week 8), and follow up (week 12). Intention-to-treat analyses were undertaken. Repeated-measures ANOVA indicated a significant difference in resilience scores between the three time points, showing a large effect. Pairwise comparisons between intervention and control groups indicated resilience to be significantly different between baseline and post-test, and between baseline and follow up, but not between post-test and follow up. Overall, the intervention group showed a slightly greater increase in resilience over time than the control group; however, the time–group interaction was not significant. Guided self-help is helpful in improving caregivers’ resilience and could be used as an adjunct to the limited support provided to carers by mental health nurses and other clinicians
Macroscopic control parameter for avalanche models for bursty transport
Similarity analysis is used to identify the control parameter RA for the subset of avalanching systems that can exhibit self-organized criticality (SOC). This parameter expresses the ratio of driving to dissipation. The transition to SOC, when the number of excited degrees of freedom is maximal, is found to occur when RA-->0. This is in the opposite sense to (Kolmogorov) turbulence, thus identifying a deep distinction between turbulence and SOC and suggesting an observable property that could distinguish them. A corollary of this similarity analysis is that SOC phenomenology, that is, power law scaling of avalanches, can persist for finite RA with the same RA-->0 exponent if the system supports a sufficiently large range of lengthscales, necessary for SOC to be a candidate for physical (RA finite) systems
Venous Air Embolism Leading to Cardiac Arrest in an Infant with Cyanotic Congenital Heart Disease
Gas emboli, including venous and arterial, are a rare but important complication of pediatric cardiac surgery. They have the potential to have devastating consequences and require prompt recognition and treatment. We present a case of gas embolism occurring in the immediate postoperative period in an infant with cyanotic congenital heart disease after palliative cardiac surgery resulting in cardiopulmonary arrest. The embolism was diagnosed by visualization of air within the vessel creating an airlock and occluding pulmonary blood flow
Scaling in long term data sets of geomagnetic indices and solar wind ϵ as seen by WIND spacecraft
We study scaling in fluctuations of the geomagnetic indices (AE, AU, and AL) that provide a measure of magnetospheric activity and of the ε parameter which is a measure of the solar wind driver. Generalized structure function (GSF) analysis shows that fluctuations exhibit self-similar scaling up to about 1 hour for the AU index and about 2 hours for AL, AE and ε when the most extreme fluctuations over 10 standard deviations are excluded. The scaling exponents of the GSF are found to be similar for the three AE indices, and to differ significantly from that of ε. This is corroborated by direct comparison of their rescaled probability density functions
The Decay of Accreting Triple Systems as Brown Dwarf Formation Scenario
We investigate the dynamical decay of non-hierarchical accreting triple
systems and its implications on the ejection model as Brown Dwarf formation
scenario. A modified chain-regularization scheme is used to integrate the
equations of motion, that also allows for mass changes over time as well as for
momentum transfer from the accreted gas mass onto the bodies. We integrate an
ensemble of triple systems within a certain volume with different accretion
rates, assuming several prescriptions of how momentum is transferred onto the
bodies. We follow their evolution until the systems have decayed. We analyze
the end states and decay times of these systems and determine the fraction of
Brown Dwarfs formed, their escape speeds as well as the semi-major axis
distribution of the formed Brown Dwarf binaries. We find that the formation
probability of Brown Dwarfs depends strongly on the assumed momentum transfer
which is related to the motion of the gas. Due to ongoing accretion and
consequent shrinkage of the systems, the median escape velocity is increased by
a factor of 2 and the binary separations are decreased by a factor of 5
compared with non-accreting systems. Furthermore, the obtained semi-major axis
distribution drops off sharply to either side of the median, which is also
supported by observations. We conclude that accretion and momentum transfer of
accreted gas during the dynamical decay of triple systems is able to produce
the observed distribution of close binary Brown Dwarfs, making the ejection
model a viable option as Brown Dwarf formation scenario.Comment: 31 pages, 8 figures, accepted for publication in Ap
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