1,370 research outputs found
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Conservation in conflict: Illegal drugs versus habitat in the Americas
About the book:
State of the Wild is a biennial series that brings together international conservation experts and writers to discuss emerging issues in the conservation of wildlife and wild places.
Each volume in the series combines evocative writings with a fascinating tour of conservation news highlights and vital statistics from around the world. One-third of each volume focuses on a topic of particular concern to conservationists working to protect wildlife and our last wild places. This 2008–2009 edition considers the integration of wildlife health, ecosystem health, human health, and the health of domestic animals—a “One World–One Health” approach to disease and conservation.
This focus is complemented with essays clustered into sections that address other key issues—conservation of species; conservation of wild places; people, culture, and conservation; and the art and practice of conservation. Essays cover a broad range of topics, from restoring biodiversity on the prairies to mapping the state of the oceans to the conservation impacts of lawlessness and coca cultivation in Colombia. Essay contributions come from people directly involved in on-the-ground conservation efforts and offer a unique and valuable perspective on often-overlooked topics.
State of the Wild’s accessible approach educates a wide range of audiences while at the same time presenting leading-edge scientific overviews of hot topics in conservation. Uniquely structured with magazine-like features up front, conservation news in the middle, and essays from eminent authors and experienced scientists throughout, this landmark series is an essential addition to any environmental bookshelf
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A novel approach to bioelectrical impedance plethysmography for the assessment of arterial and venous circulatory problems in the forearm
Peripheral vascular disease (PVD) and/or peripheral arterial disease (PAD) are sicknesses known to inadequate delivery of either arterial or venous blood towards the extremities. Such sickness may trigger complications owing to the lack of transport of oxygen and nutrients, thus causing hypoxic events that may eventually prompt to ischaemic tissue or even the loss of the compromised limb. One of the most prominent indicators of prosperous health is blood volume and flow. The basic information within these health parameters may show cardiovascular problems or the advance of further complications related to other diseases like diabetes. In clinical setting, there effective methods to measure these parameters like Doppler ultrasound, photoplethysmography or venous occlusion plethysmography.
These methods take measurements from either single vessels and/or small volume of tissue. However, it is difficult to establish a relation between the obstruction of arterial and/or venous circulation and the amount of blood received by the tissue. Bioelectrical impedance plethysmography (iPG) measures blood changes by driving a small amount of AC current into the body and after measuring the potential created by fluids flowing through tissue. This technique apart from taking measures within defined volumes of tissue, it is easy to use as only needs four electrodes on the skin.
Hence, a bespoken bioelectrical impedance device including hardware and software was built ready to measure changes in blood volume/flow in the upper limbs. The system was assessed in an in-vivo controlled environment with 8 participants. The blood flow towards their left arms was altered by constricting the upper arm with a cuff at three levels: 1) below venous pressure 2) amongst venous and arterial pressure and 3) during total occlusion. Simultaneously, measurements from various instruments like ECG, Doppler ultrasound, laser Doppler flowmetry and PPG were taken and compared to the measurements obtained from the iPG instrument and defining its correlation with the impedimetric signal.
The results from the experiments showed that the bioelectrical impedance signal changed in basal and arterial pulses showing specific characteristics for each kind of occlusion. The data indicated that it is possible to differentiate between a venous and arterial occlusion by examining both components of the impedance signal. The impedance during venous occlusion dropped in average 0.658±0.230% from the baseline. On the other hand, during arterial occlusion the base impedance dropped in a higher rate approximately 1.13±04.82%, indicating a differentiator during both type of blood flow disruption. Furthermore, the impedance plethysmography waveform morphology also reshaped during these occlusive periods. The whole waveform during artificial venous obstruction increased in magnitude, the systolic peak rose 31.80%, the dicrotic notch 47.73% and the diastolic point 31.92%, where the value of the latter was higher than the dicrotic notch point. In contrast, in the time of partial arterial occlusion the waveform also increased in size at all these points, but its shape was altered. The impedance magnitude at the diastolic point went below the ones at the dicrotic notch. These fluctuations provided additional further information that it might be possible to differentiate amongst venous and arterial occlusions. By consolidating the data obtained by the iPG device, it is possible to produce an index ratio between the basal impedance and these three reference points which may help to identify early circulatory problems in the arterial and/or venous systems
SimpatectomĂa toracoscĂłpica: una revisiĂłn de la literatura
INTRODUCTION: Since its first description by Kux in 1954, the thoracic endoscopic
(thoracoscopic) sympathectomy has rendered the open techniques obsolete in the
treatment of the hyperhidrosis and other sympathetic-related diseases. AIM. The
goal of this article is to present a critical review of the current indications,
results and complications of the endoscopic thoracic sympathectomy. MATERIAL AND
METHODS: An extensive search and review of published papers on the thoracoscopic
sympathectomy was undertaken. RESULTS: The thoracoscopic sympathectomy has
evolved as a therapeutic choice in patients with focal hyperhidrosis, pain
syndromes and peripheral vascular disorders, particularly. The results,
recurrences and complications are similar to the previously established open
procedures; nevertheless, the morbidity, the hospital stay and the time to return
to activities of daily living are substantially reduced. The highest success and
satisfaction rates (over 95%) were observed among patients treated for focal
hyperhidrosis. CONCLUSIONS: The success and complication rates of thoracoscopic
sympathectomy are comparable to those of open techniques, with an easier
postoperative period and an earlier return to labor and daily living
Dilaton thin-shell wormholes supported by a generalized Chaplygin gas
In this article, we construct spherical thin-shell wormholes with charge in
dilaton gravity. The exotic matter required for the construction is provided by
a generalized Chaplygin gas. We study the stability under perturbations
preserving the symmetry. We find that the increase of the coupling between the
dilaton and the electromagnetic fields reduces the range of the parameters for
which stable configurations are possible.Comment: 14 pages, 6 figures. v3: typos correcte
A Theoretical Construction of Thin Shell Wormhole from Tidal Charged Black hole
Recently, Dadhich et al [ Phys.Lett.B 487, 1 (2000)] have discovered a black
hole solution localized on a three brane in five dimensional gravity in the
Randall-Sundrum scenario. In this article, we develop a new class of thin shell
wormhole by surgically grafting above two black hole spacetimes. Various
aspects of this thin wormhole are also analyzed.Comment: 14 pages, 6 figures, Accepted in Gen.Rel.Gra
Assessing the relative accuracy of coral heights reconstructed from drones and structure from motion photogrammetry on coral reefs
Low-altitude high-resolution aerial photographs allow for the reconstruction of structural properties of shallow coral reefs and the quantification of their topographic complexity. This study shows the scope and limitations of two-media (air/water) Structure from Motion—Multi-View Stereo reconstruction method using drone aerial photographs to reconstruct coral height. We apply this method in nine different sites covering a total area of about 7000 m2, and we examine the suitability of the method to obtain topographic complexity estimates (i.e., seafloor rugosity). A simple refraction correction and survey design allowed reaching a root mean square error of 0.1 m for the generated digital models of the seafloor (without the refraction correction the root mean square error was 0.2 m). We find that the complexity of the seafloor extracted from the drone digital models is slightly underestimated compared to the one measured with a traditional in situ survey method
Motivation and Hedonic Hunger as Predictors of Self-Reported Food Intake in Adolescents: Disentangling Between-Person and Within-Person Processes
Background: Dietary behavior contributes substantially to health across the lifespan. Understanding interactions between stable characteristics and fluctuating drive states underlying youth’s food choices may inform methods for promoting more healthful food intake. The present study examined dietary motivation and hedonic hunger as interacting predictors of adolescents’ consumption of sweet, starchy, fatty, and fast foods. Methods: Intensive longitudinal data were collected from 50 adolescent participants (ages 13-18) over a 20-day study period. Participants completed a measure of dietary motivation at baseline and reported on hedonic hunger and consumption of palatable foods via a smartphone application at the end of each study day. Results: Results indicated that 66.7% of the variability in hedonic hunger was between-person and 33.3% was within-person. Between-person hedonic hunger was positively associated with consumption of fatty foods ( = .28, p < .05) and within-person hedonic hunger was positively associated with consumption of starchy foods ( = .38, p < .0001). A significant cross-level interaction indicated that as hedonic hunger increased, the slope relating controlled motivation to starchy food consumption become more strongly positive. Autonomous motivation was negatively associated with consumption of fast foods ( = -.14, p < .05). Additionally, the interaction term of within-person hedonic hunger and autonomous motivation indicated that as hedonic hunger increased, the slope relating autonomous motivation to fast food consumption became more strongly negative. Conclusions: Findings indicate that hedonic hunger has the potential to fluctuate over time, but conceptualization of the variable as both trait and state may be most appropriate given the current findings. Results confirmed that unique relationships exist between trait motivation and fluctuating hedonic hunger, and that the interactions of these variables may hold value in understanding and addressing unhealthful dietary choices. In particular, adolescents with high controlled motivation for diet may be vulnerable to the influence of hedonic hunger and especially prone to eating higher quantities of starchy foods. Adolescents with high autonomous motivation for diet may be less vulnerable to the experience of hedonic hunger and less likely to consume fast food
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