2,853 research outputs found
Trends in potential exposure to Australian bat lyssavirus in South East Queensland, 1996 to 2003
This study examined trends in notifications of potential exposure to Australian bat lyssavirus reported to the Brisbane Southside Public Health Unit, Australia between 1 November 1996 and 31 January 2003. Notification rates declined among all population groups and potential exposures were notified more promptly. Concern exists regarding possible under-reporting of potential exposure to Australian bat lyssavirus especially among volunteer bat carers. (author abstract
Observations of H3+ in the Diffuse Interstellar Medium
Surprisingly large column densities of H3+ have been detected using infrared
absorption spectroscopy in seven diffuse cloud sightlines (Cygnus OB2 12,
Cygnus OB2 5, HD 183143, HD 20041, WR 104, WR 118, and WR 121), demonstrating
that H3+ is ubiquitous in the diffuse interstellar medium. Using the standard
model of diffuse cloud chemistry, our H3+ column densities imply unreasonably
long path lengths (~1 kpc) and low densities (~3 cm^-3). Complimentary
millimeter-wave, infrared, and visible observations of related species suggest
that the chemical model is incorrect and that the number density of H3+ must be
increased by one to two orders of magnitude. Possible solutions include a
reduced electron fraction, an enhanced rate of H2 ionization, and/or a smaller
value of the H3+ dissociative recombination rate constant than implied by
laboratory experiments.Comment: To be published in Astrophysical Journal, March 200
Linear and nonlinear modulus surfaces in stress space, from stress-strain measurements on Berea sandstone
International audienceThe elastic response of many rocks to quasistatic stress changes is highly nonlinear and hysteretic, displaying discrete memory. Rocks also display unusual nonlinear response to dynamic stress changes. A model to describe the elastic behavior of rocks and other consolidated materials is called the Preisach-Mayergoyz (PM) space model. In contrast to the traditional analytic approach to stress-strain, the PM space picture establishes a relationship between the quasistatic data and a number density of hysteretic mesoscopic elastic elements in the rock. The number density allows us to make quantitative predictions of dynamic elastic properties. Using the PM space model, we analyze a complex suite of quasistatic stress-strain data taken on Berea sandstone. We predict a dynamic bulk modulus and a dynamic shear modulus surface as a function of mean stress and shear stress. Our predictions for the dynamic moduli compare favorably to moduli derived from time of flight measurements. We derive a set of nonlinear elastic constants and a set of constants that describe the hysteretic behavior of the sandstone
Spatiotemporally Localized Multidimensional Solitons in Self-Induced Transparency Media
"Light bullets" are multi-dimensional solitons which are localized in both
space and time. We show that such solitons exist in two- and three-dimensional
self-induced-transparency media and that they are fully stable. Our approximate
analytical calculation, backed and verified by direct numerical simulations,
yields the multi-dimensional generalization of the one-dimensional Sine-Gordon
soliton.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let
Optimizing postprandial glucose management in adults with insulin-requiring diabetes: Report and recommendations
Faster-acting insulins, new noninsulin drug classes, more flexible insulin-delivery systems, and improved continuous glucose monitoring devices offer unprecedented opportunities to improve postprandial glucose (PPG) management and overall care for adults with insulin-treated diabetes. These developments led the Endocrine Society to convene a working panel of diabetes experts in December 2018 to assess the current state of PPG management, identify innovative ways to improve self-management and quality of life, and align best practices to current and emerging treatment and monitoring options. Drawing on current research and collective clinical experience, we considered the following issues for the âŒ200 million adults worldwide with type 1 and insulin-requiring type 2 diabetes: (i) the role of PPG management in reducing the risk of diabetes complications; (ii) barriers preventing effective PPG management; (iii) strategies to reduce PPG excursions and improve patient quality of life; and (iv) education and clinical tools to support endocrinologists in improving PPG management. We concluded that managing PPG to minimize or prevent diabetes-related complications will require elucidating fundamental questions about optimal ways to quantify and clinically assess the metabolic dysregulation and consequences of the abnormal postprandial state in diabetes and recommend research strategies to address these questions. We also identified practical strategies and tools that are already available to reduce barriers to effective PPG management, optimize use of new and emerging clinical tools, and improve patient self-management and quality of life
Impact of early exposure to a cafeteria diet on prefrontal cortex monoamines and novel object recognition in adolescent rats
© 2019 Elsevier B.V. The prefrontal cortex (PFC) undergoes protracted postnatal development such that its structure and behavioural function may be profoundly altered by environmental factors. Here we investigate the effect of lactational dietary manipulations on novel object recognition (NOR) learning and PFC monoamine neurotransmitter metabolism in early adolescent rats. To this end, Wistar rat dams were fed a high caloric cafeteria diet (CD) during lactation and resultant 24â26 day old offspring exposed to NOR testing and simultaneous PFC dopamine and serotonin metabolism measurement. In the second NOR choice trial where one familiar and one novel object were presented controls explored the novel preferentially to the familiar object both after a 5 min (P < 0.001) or 30 min (P < 0.05) inter-trial intervals (ITI). By contrast, offspring from dams fed on lactational CD failed to show any significant preference for the novel object at either time point. Compared with chow fed controls, their average exploration ratio of the novel object was lower after the 5 min ITI (P < 0.05). Following a 60 min ITI, neither CD nor control offspring showed a preference for the novel object. PFC dopamine metabolism was significantly reduced in the CD group (P < 0.001), whereas serotonin metabolism was increased (P < 0.001). These results suggest that an obesogenic lactational diet can have a detrimental impact on cognition in adolescent offspring associated with aberrant PFC serotonin and dopamine metabolism
Impact of hemoglobin levels and anemia on mortality in acute stroke: analysis of UK regional registry data, systematic review and meta-analysis
Background: The impact of hemoglobin levels and anemia on stroke mortality remains controversial. We aimed to systematically assess this association and quantify the evidence. Methods and Results: We analysed data from a cohort of 8,013 stroke patients (mean (sd) 77.81±11.83 years) consecutively admitted over 11 years (January 2003âMay 2015) using a UK Regional Stroke Register. The impact of hemoglobin levels and anemia on mortality was assessed by sex-specific values at different time points (7-day, 14-day, 1-month, 3-month, 6-month, 1 year), using multiple regression models controlling for confounders. Anemia was present in 24.5% of the cohort on admission and was associated with increased odds of mortality at most of the time points examined up to 1 year following stroke. The association was less consistent for males with hemorrhagic stroke. Elevated haemoglobin was also associated with increased mortality, mainly within the first month. We then conducted a systematic review using the EMBASE and Medline databases. Twenty studies met the inclusion criteria. When combined with the cohort from the current study, this gave a pooled population of 29,943 patients with stroke. The evidence base was quantified in a meta-analysis. Anemia on admission was found to be associated with an increased risk of mortality in both ischemic stroke (8 studies); OR 1.97(1.56â 2.47) and hemorrhagic stroke (4 studies); OR 1.46(1.23â1.74). Conclusions: There is strong evidence that patients with anemia have increased mortality in stroke. Targeted interventions in this patient population may improve outcomes and therefore require further evaluation
Spatiotemporally localized solitons in resonantly absorbing Bragg reflectors
We predict the existence of spatiotemporal solitons (``light bullets'') in
two-dimensional self-induced transparency media embedded in a Bragg grating.
The "bullets" are found in an approximate analytical form, their stability
being confirmed by direct simulations. These findings suggest new possibilities
for signal transmission control and self-trapping of light.Comment: RevTex, 3 pages, 2 figures, to be published in PR
Gyrotropic impact upon negatively refracting surfaces
Surface wave propagation at the interface between different types of gyrotropic materials and an isotropic negatively refracting medium, in which the relative permittivity and relative permeability are, simultaneously, negative is investigated. A general approach is taken that embraces both gyroelectric and gyromagnetic materials, permitting the possibility of operating in either the low GHz, THz or the optical frequency regimes. The classical transverse Voigt configuration is adopted and a complete analysis of non-reciprocal surface wave dispersion is presented. The impact of the surface polariton modes upon the reflection of both plane waves and beams is discussed in terms of resonances and an example of the influence upon the GoosâHĂ€nchen shift is given
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