924 research outputs found
New Records of the Eastern Red Bat, Lasiurus borealis, from Cypress Hills Provincial Park, Saskatchewan: A Response to Climate Change?
During the summer of 2001 we captured two Eastern Red Bats (Lasiurus borealis) in Cypress Hills Provincial Park, Saskatchewan. A possible explanation for this range extension is a warming trend since 1965 documented for the area
Fractal Descriptors in the Fourier Domain Applied to Color Texture Analysis
The present work proposes the development of a novel method to provide
descriptors for colored texture images. The method consists in two steps. In
the first, we apply a linear transform in the color space of the image aiming
at highlighting spatial structuring relations among the color of pixels. In a
second moment, we apply a multiscale approach to the calculus of fractal
dimension based on Fourier transform. From this multiscale operation, we
extract the descriptors used to discriminate the texture represented in digital
images. The accuracy of the method is verified in the classification of two
color texture datasets, by comparing the performance of the proposed technique
to other classical and state-of-the-art methods for color texture analysis. The
results showed an advantage of almost 3% of the proposed technique over the
second best approach.Comment: Chaos, Volume 21, Issue 4, 201
Chronic y-secretase inhibition reduces amyloid plaque-associated instability of pre- and postsynaptic structures
The loss of synapses is a strong histological correlate of the cognitive decline in Alzheimer’s disease (AD). Amyloid bpeptide (Ab), a cleavage product of the amyloid precursor protein (APP), exerts detrimental effects on synapses, a process thought to be causally related to the cognitive deficits in AD. Here, we used in vivo two-photon microscopy to characterize the dynamics of axonal boutons and dendritic spines in APP/Presenilin 1 (APPswe/PS1L166P)–green fluorescent protein (GFP) transgenic mice. Time-lapse imaging over 4 weeks revealed a pronounced, concerted instability of pre- and postsynaptic structures within the vicinity of amyloid plaques. Treatment with a novel sulfonamide-type g-secretase inhibitor (GSI) attenuated the formation and growth of new plaques and, most importantly, led to a normalization of the enhanced dynamics of synaptic structures close to plaques. GSI treatment did neither affect spines and boutons distant from plaques in amyloid precursor protein/presenilin 1-GFP (APPPS1-GFP) nor those in GFP-control mice, suggesting no obvious neuropathological side effects of the drug
Hierarchical search strategy for the detection of gravitational waves from coalescing binaries: Extension to post-Newtonian wave forms
The detection of gravitational waves from coalescing compact binaries would
be a computationally intensive process if a single bank of template wave forms
(i.e., a one step search) is used. In an earlier paper we had presented a
detection strategy, called a two step search}, that utilizes a hierarchy of
template banks. It was shown that in the simple case of a family of Newtonian
signals, an on-line two step search was about 8 times faster than an on-line
one step search (for initial LIGO). In this paper we extend the two step search
to the more realistic case of zero spin 1.5 post-Newtonian wave forms. We also
present formulas for detection and false alarm probabilities which take
statistical correlations into account. We find that for the case of a 1.5
post-Newtonian family of templates and signals, an on-line two step search
requires about 1/21 the computing power that would be required for the
corresponding on-line one step search. This reduction is achieved when signals
having strength S = 10.34 are required to be detected with a probability of
0.95, at an average of one false event per year, and the noise power spectral
density used is that of advanced LIGO. For initial LIGO, the reduction achieved
in computing power is about 1/27 for S = 9.98 and the same probabilities for
detection and false alarm as above.Comment: 30 page RevTeX file and 17 figures (postscript). Submitted to PRD Feb
21, 199
Nanowired three-dimensional cardiac patches
Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds1, 2, 3. These biomaterials, which are usually made of either biological polymers such as alginate4 or synthetic polymers such as poly(lactic acid) (PLA)5, help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit6. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.National Institutes of Health (U.S.) (NIH, grant GM073626)National Institutes of Health (U.S.) (NIH, grant DE13023)National Institutes of Health (U.S.) (NIH, grant DE016516)American Heart Association (Postdoctoral Fellowship)National Institutes of Health (U.S.) (Ruth L. Kirschstein National Research Service Award (no. F32GM096546)
The Impact of Railway Stations on Residential and Commercial Property Value: A Meta-analysis
Railway stations function as nodes in transport networks and places in an urban environment. They have accessibility and environmental impacts, which contribute to property value. The literature on the effects of railway stations on property value is mixed in its finding in respect to the impact magnitude and direction, ranging from a negative to an insignificant or a positive impact. This paper attempts to explain the variation in the findings by meta-analytical procedures. Generally the variations are attributed to the nature of data, particular spatial characteristics, temporal effects and methodology. Railway station proximity is addressed from two spatial considerations: a local station effect measuring the effect for properties with in 1/4 mile range and a global station effect measuring the effect of coming 250 m closer to the station. We find that the effect of railway stations on commercial property value mainly takes place at short distances. Commercial properties within 1/4 mile rang are 12.2% more expensive than residential properties. Where the price gap between the railway station zone and the rest is about 4.2% for the average residence, it is about 16.4% for the average commercial property. At longer distances the effect on residential property values dominate. We find that for every 250 m a residence is located closer to a station its price is 2.3% higher than commercial properties. Commuter railway stations have a consistently higher positive impact on the property value compared to light and heavy railway/Metro stations. The inclusion of other accessibility variables (such as highways) in the models reduces the level of reported railway station impact. © 2007 Springer Science+Business Media, LLC
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Use of ceragenins to create novel biofouling resistant water-treatment membranes.
Scoping studies have demonstrated that ceragenins, when linked to water-treatment membranes have the potential to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced molecules that mimic antimicrobial peptides. Evidence includes measurements of CSA-13 prohibiting the growth of and killing planktonic Pseudomonas fluorescens. In addition, imaging of biofilms that were in contact of a ceragenin showed more dead cells relative to live cells than in a biofilm that had not been treated with a ceragenin. This work has demonstrated that ceragenins can be attached to polyamide reverse osmosis (RO) membranes, though work needs to improve the uniformity of the attachment. Finally, methods have been developed to use hyperspectral imaging with multivariate curve resolution to view ceragenins attached to the RO membrane. Future work will be conducted to better attach the ceragenin to the RO membranes and more completely test the biocidal effectiveness of the ceragenins on the membranes
Direct Gene Transfer for the Understanding and Treatment of Human Disease
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75762/1/j.1749-6632.1994.tb21709.x.pd
Mapping research activity on mental health disorders in Europe: Study protocol for the Mapping_NCD project
© 2016 The Author(s). Background: Mental health disorders (MHDs) constitute a large and growing disease burden in Europe, although they typically receive less attention and research funding than other non-communicable diseases (NCDs). This study protocol describes a methodology for the mapping of MHD research in Europe as part of Mapping_NCD, a 2-year project funded by the European Commission which seeks to map European research funding and impact for five NCDs in order to identify potential gaps, overlaps, synergies and opportunities, and to develop evidence-based policies for future research. Methods: The project aims to develop a multi-focal view of the MHD research landscape across the 28 European Union Member States, plus Iceland, Norway and Switzerland, through a survey of European funding entities, analysis of research initiatives undertaken in the public, voluntary/not-for-profit and commercial sectors, and expert interviews to contextualize the gathered data. The impact of MHD research will be explored using bibliometric analyses of scientific publications, clinical guidelines and newspaper stories reporting on research initiatives. Finally, these research inputs and outputs will be considered in light of various metrics that have been proposed to inform priorities for the allocation of research funds, including burden of disease, treatment gaps and cost of illness. Discussion: Given the growing burden of MHDs, a clear and broad view of the current state of MHD research is needed to ensure that limited resources are directed to evidence-based priority areas. MHDs pose a particular challenge in mapping the research landscape due to their complex nature, high co-morbidity and varying diagnostic criteria. Undertaking such an effort across 31 countries is further challenged by differences in data collection, healthcare systems, reimbursement rates and clinical practices, as well as cultural and socioeconomic diversity. Using multiple methods to explore the spectrum of MHD research funding activity across Europe, this project aims to develop a broad, high-level perspective to inform priority setting for future research
Torpor, arousal and activity of hibernating greater horseshoe bats (Rhinolophus ferrumequinum)
1. Patterns of torpor, arousal, and activity in free-living greater horseshoe bats, Rhinolophus ferrumequinum, were investigated during the hibernation period by using temperature-sensitive radio-transmitters. 2. Torpor bouts varied between 0.1 - 11.8 days, with individual means ranging from 1.3 - 7.4 days. Torpor bout duration decreased with increasing ambient temperature. 3. Activity duration varied from 37 minutes – 54 hours 24 minutes, with individual means ranging from 2:29 to 8:58 hours. Activity duration increased with ambient temperatures above approximately 10oC. 4. Ten of 11 bats synchronised their arousals with dusk. The circadian rhythm of one bat showed a free-running pattern over a period of about five weeks. Arousals were more highly synchronised, and closer to dusk, in individuals with lower body condition. 5. That bats forage in mild weather is supported by the strong synchronisation of arousals with dusk, especially in bats with low body condition. 6. Patterns of torpor and subsequent activity are consistent with predictions that torpor lasts until a critical metabolic or water imbalance is achieved. Because metabolism and water loss are temperature-dependent, torpor bout duration decreases with increasing temperature. The imbalance is corrected during subsequent activity, which is relatively constant in duration until a temperature threshold of 10oC, above which increasing levels of foraging lead to longer activity bouts
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