12,329 research outputs found
GENERATION OF RECYCLABLES BY RURAL HOUSEHOLDS
Rising landfill costs have forced solid waste managers to consider ways to reduce the waste stream. Using survey data, models explaining the weight of recyclables generated by households are estimated for paper and glass. Results indicate that households respond to the time cost of recycling paper but not glass. The waste generation models imply total monthly willingness to pay for recycling is $5.78 per household. Waste managers may increase the weight of recycled waste stream with programs which lower perceived time costs of nonrecyclers and improve the efficiency of recyclers.Consumer/Household Economics, Environmental Economics and Policy,
EXPLAINING RURAL HOUSEHOLD PARTICIPATION IN RECYCLING
Rising landfill costs have forced solid waste managers to consider waste stream reduction alternatives such as household recycling. Explaining the factors which motivate households to recycle is important to regions where households must bear a large portion of the recycling cost because unit-based garbage disposal fees and curbside recycling are not feasible options. Empirical results indicate that residents are responsive to constraints introduced by the household production technology, such as time costs and storage space, but are not responsive to variables measuring a recycling promotional program. Promotion efforts should switch focus from broader "public good" benefits of recycling to reducing household-level household production constraints.Dropoff recycling, Household recycling participation, Rural regions, Environmental Economics and Policy,
Sequence similarity between stereocilin and otoancorin points to a unified mechanism for mechanotransduction in the mammalian inner ear
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Interaction between hair cells and acellular gels of the mammalian inner ear, the tectorial and otoconial membranes, is crucial for mechanoreception. Recently, otoancorin was suggested to be a mediator of gel attachment to nonsensory cells, but the molecular components of the interface between gels and sensory cells remain to be identified. Hypothesis We report that the inner ear protein stereocilin is related in sequence to otoancorin and, based on its localisation and predicted GPI-anchoring, may mediate attachment of the tectorial and otoconial membranes to sensory hair bundles. Testing It is expected that antibodies directed against stereocilin would specifically label sites of contact between sensory hair cells and tectorial/otoconial membranes of the inner ear. Implications Our findings support a unified molecular mechanism for mechanotransduction, with stereocilin and otoancorin defining a new protein family responsible for the attachment of acellular gels to both sensory and nonsensory cells of the inner ear.Published versio
Disrupted functional brain network organization in patients with obstructive sleep apnea.
IntroductionObstructive sleep apnea (OSA) subjects show impaired autonomic, affective, executive, sensorimotor, and cognitive functions. Brain injury in OSA subjects appears in multiple sites regulating these functions, but the integrity of functional networks within the regulatory sites remains unclear. Our aim was to examine the functional interactions and the complex network organization of these interactions across the whole brain in OSA, using regional functional connectivity (FC) and brain network topological properties.MethodsWe collected resting-state functional magnetic resonance imaging (MRI) data, using a 3.0-Tesla MRI scanner, from 69 newly diagnosed, treatment-naïve, moderate-to-severe OSA (age, 48.3 ± 9.2 years; body mass index, 31 ± 6.2 kg/m(2); apnea-hypopnea index (AHI), 35.6 ± 23.3 events/h) and 82 control subjects (47.6 ± 9.1 years; body mass index, 25.1 ± 3.5 kg/m(2)). Data were analyzed to examine FC in OSA over controls as interregional correlations and brain network topological properties.ResultsObstructive sleep apnea subjects showed significantly altered FC in the cerebellar, frontal, parietal, temporal, occipital, limbic, and basal ganglia regions (FDR, P < 0.05). Entire functional brain networks in OSA subjects showed significantly less efficient integration, and their regional topological properties of functional integration and specialization characteristics also showed declined trends in areas showing altered FC, an outcome which would interfere with brain network organization (P < 0.05; 10,000 permutations). Brain sites with abnormal topological properties in OSA showed significant relationships with AHI scores.ConclusionsOur findings suggest that the dysfunction extends to resting conditions, and the altered FC and impaired network organization may underlie the impaired responses in autonomic, cognitive, and sensorimotor functions. The outcomes likely result from the prominent structural changes in both axons and nuclear structures, which occur in the condition
Unilateral Lymphangiomatous Polyp of the Palatine Tonsil in a Very Young Child: A Clinicopathologic Case Report
Childhood lymphangiomatous polyp of the palatine tonsil is a very unusual lesion found in the head and neck. Tonsillectomy has been reported to be the curative procedure of choice for this lesion. We report a case of a very young child with unilateral lymphangiomatous polyp of the palatine tonsil
Dark-ages reionization and galaxy formation simulation XI: Clustering and halo masses of high redshift galaxies
We investigate the clustering properties of Lyman-break galaxies (LBGs) at
- . Using the semi-analytical model {\scshape Meraxes} constructed
as part of the Dark-ages Reionization And Galaxy-formation Observables from
Numerical Simulation (DRAGONS) project, we predict the angular correlation
function (ACF) of LBGs at - . Overall, we find that the predicted
ACFs are in good agreement with recent measurements at and from observations consisting of the Hubble eXtreme Deep Field (XDF), the
Hubble Ultra-Deep Field (HUDF) and Cosmic Assembly Near-infrared Deep
Extragalactic Legacy Survey (CANDELS) field. We confirm the dependence of
clustering on luminosity, with more massive dark matter haloes hosting brighter
galaxies, remains valid at high redshift. The predicted galaxy bias at fixed
luminosity is found to increase with redshift, in agreement with observations.
We find that LBGs of magnitude at reside in dark matter haloes of mean mass -
, and this dark matter halo mass does not evolve
significantly during reionisation.Comment: 14 pages, 10 figures, published in MNRA
The influence of electron collisions on non-LTE Li line formation in stellar atmospheres
The influence of the uncertainties in the rate coefficient data for
electron-impact excitation and ionization on non-LTE Li line formation in cool
stellar atmospheres is investigated. We examine the electron collision data
used in previous non-LTE calculations and compare them to recent calculations
that use convergent close-coupling (CCC) techniques and to our own calculations
using the R-matrix with pseudostates (RMPS) method. We find excellent agreement
between rate coefficients from the CCC and RMPS calculations, and reasonable
agreement between these data and the semi-empirical data used in non-LTE
calculations up to now. The results of non-LTE calculations using the old and
new data sets are compared and only small differences found: about 0.01 dex (~
2%) or less in the abundance corrections. We therefore conclude that the
influence on non-LTE calculations of uncertainties in the electron collision
data is negligible. Indeed, together with the collision data for the charge
exchange process Li(3s) + H Li^+ + H^- now available, and barring the
existence of an unknown important collisional process, the collisional data in
general is not a source of significant uncertainty in non-LTE Li line formation
calculations.Comment: 8 pages, accepted by Astronomy and Astrophysics; Replaced with minor
corrections following proof
Reduced regional brain cortical thickness in patients with heart failure.
AimsAutonomic, cognitive, and neuropsychologic deficits appear in heart failure (HF) subjects, and these compromised functions depend on cerebral cortex integrity in addition to that of subcortical and brainstem sites. Impaired autoregulation, low cardiac output, sleep-disordered-breathing, hypertension, and diabetic conditions in HF offer considerable potential to affect cortical areas by loss of neurons and glia, which would be expressed as reduced cortical thicknesses. However, except for gross descriptions of cortical volume loss/injury, regional cortical thickness integrity in HF is unknown. Our goal was to assess regional cortical thicknesses across the brain in HF, compared to control subjects.Methods and resultsWe examined localized cortical thicknesses in 35 HF and 61 control subjects with high-resolution T1-weighted images (3.0-Tesla MRI) using FreeSurfer software, and assessed group differences with analysis-of-covariance (covariates; age, gender; p<0.05; FDR). Significantly-reduced cortical thicknesses appeared in HF over controls in multiple areas, including the frontal, parietal, temporal, and occipital lobes, more markedly on the left side, within areas that control autonomic, cognitive, affective, language, and visual functions.ConclusionHeart failure subjects show reduced regional cortical thicknesses in sites that control autonomic, cognitive, affective, language, and visual functions that are deficient in the condition. The findings suggest chronic tissue alterations, with regional changes reflecting loss of neurons and glia, and presumably are related to earlier-described axonal changes. The pathological mechanisms contributing to reduced cortical thicknesses likely include hypoxia/ischemia, accompanying impaired cerebral perfusion from reduced cardiac output and sleep-disordered-breathing and other comorbidities in HF
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