332 research outputs found

    A Computational Approach for Designing Tiger Corridors in India

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    Wildlife corridors are components of landscapes, which facilitate the movement of organisms and processes between intact habitat areas, and thus provide connectivity between the habitats within the landscapes. Corridors are thus regions within a given landscape that connect fragmented habitat patches within the landscape. The major concern of designing corridors as a conservation strategy is primarily to counter, and to the extent possible, mitigate the effects of habitat fragmentation and loss on the biodiversity of the landscape, as well as support continuance of land use for essential local and global economic activities in the region of reference. In this paper, we use game theory, graph theory, membership functions and chain code algorithm to model and design a set of wildlife corridors with tiger (Panthera tigris tigris) as the focal species. We identify the parameters which would affect the tiger population in a landscape complex and using the presence of these identified parameters construct a graph using the habitat patches supporting tiger presence in the landscape complex as vertices and the possible paths between them as edges. The passage of tigers through the possible paths have been modelled as an Assurance game, with tigers as an individual player. The game is played recursively as the tiger passes through each grid considered for the model. The iteration causes the tiger to choose the most suitable path signifying the emergence of adaptability. As a formal explanation of the game, we model this interaction of tiger with the parameters as deterministic finite automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201

    Impacts of traditional food consumption advisories: Compliance, changes in diet and loss of confidence in traditional foods

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    <p>Abstract</p> <p>Background</p> <p>Food consumption advisories are often posted when industrial activities are expected to affect the quality and availability of traditional foods used by First Nations. We were recently involved in a project and asked to summarize details regarding the impacts of traditional food consumption advisories with respect to compliance, broader changes in diet and loss of confidence in traditional foods by people.</p> <p>Methods</p> <p>Our review was not conducted as a formal systematic comprehensive review; rather, we focused on primary and grey literature presenting academic, health practitioner and First Nations viewpoints on the topic available from literature databases (i.e., PubMed, Web of Knowledge<sup>SM</sup>) as well as the internet search engine Google. Some information came from personal communications.</p> <p>Results</p> <p>Our overview suggests that when communicated effectively and clearly, and when community members are involved in the process, consumption advisories can result in a decrease in contaminant load in people. On the other hand, consumption advisories can lead to cultural loss and have been linked to a certain amount of social, psychological, nutritional, economic and lifestyle disruption. In some cases, communities have decided to ignore consumption advisories opting to continue with traditional lifestyles believing that the benefits of doing so outweigh the risk of following advisories.</p> <p>Conclusions</p> <p>We identified that there are both positive and negative aspects to the issuance of traditional food consumption advisories. A number of variables need to be recognized during the development and implementation of advisories in order to ensure a balance between human health, maintenance of cultures and industrial activity.</p

    Secular Evolution and the Formation of Pseudobulges in Disk Galaxies

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    We review internal processes of secular evolution in galaxy disks, concentrating on the buildup of dense central features that look like classical, merger-built bulges but that were made slowly out of disk gas. We call these pseudobulges. As an existence proof, we review how bars rearrange disk gas into outer rings, inner rings, and gas dumped into the center. In simulations, this gas reaches high densities that plausibly feed star formation. In the observations, many SB and oval galaxies show central concentrations of gas and star formation. Star formation rates imply plausible pseudobulge growth times of a few billion years. If secular processes built dense central components that masquerade as bulges, can we distinguish them from merger-built bulges? Observations show that pseudobulges retain a memory of their disky origin. They have one or more characteristics of disks: (1) flatter shapes than those of classical bulges, (2) large ratios of ordered to random velocities indicative of disk dynamics, (3) small velocity dispersions, (4) spiral structure or nuclear bars in the bulge part of the light profile, (5) nearly exponential brightness profiles, and (6) starbursts. These structures occur preferentially in barred and oval galaxies in which secular evolution should be rapid. So the cleanest examples of pseudobulges are recognizable. Thus a large variety of observational and theoretical results contribute to a new picture of galaxy evolution that complements hierarchical clustering and merging.Comment: 92 pages, 21 figures in 30 Postscript files; to appear in Annual Review of Astronomy and Astrophysics, Vol. 42, 2004, in press; for a version with full resolution figures, see http://chandra.as.utexas.edu/~kormendy/ar3ss.htm

    A Mathematical model for Astrocytes mediated LTP at Single Hippocampal Synapses

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    Many contemporary studies have shown that astrocytes play a significant role in modulating both short and long form of synaptic plasticity. There are very few experimental models which elucidate the role of astrocyte over Long-term Potentiation (LTP). Recently, Perea & Araque (2007) demonstrated a role of astrocytes in induction of LTP at single hippocampal synapses. They suggested a purely pre-synaptic basis for induction of this N-methyl-D- Aspartate (NMDA) Receptor-independent LTP. Also, the mechanisms underlying this pre-synaptic induction were not investigated. Here, in this article, we propose a mathematical model for astrocyte modulated LTP which successfully emulates the experimental findings of Perea & Araque (2007). Our study suggests the role of retrograde messengers, possibly Nitric Oxide (NO), for this pre-synaptically modulated LTP.Comment: 51 pages, 15 figures, Journal of Computational Neuroscience (to appear

    Hyperbaric oxygen therapy for painful bladder syndrome/interstitial cystitis resistant to conventional treatments: long-term results of a case series in Japan

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    <p>Abstract</p> <p>Background</p> <p>There is no confirmed strategy for treating painful bladder syndrome/interstitial cystitis (PBS/IC) with unclear etiology. Therefore, a pilot study was carried out to evaluate the efficacy and safety of hyperbaric oxygen (HBO) therapy in treatment-resistant PBS/IC patients.</p> <p>Methods</p> <p>HBO treatment (2.0 ATA for 60 minutes/day × 5 days/week for 2 or 4 weeks) was performed on 11 patients with severe symptoms that had not been improved by previous therapy regimens between December 2004 and July 2009.</p> <p>Results</p> <p>Seven of the 11 patients demonstrated persistent improvement in symptoms during the 12 months after HBO treatment. These responders demonstrated a decrease in the pelvic pain scale and urgency scale from 7.7 ± 1.0 and, 6.6 ± 0.9 to 3.4 ± 2.5 and 4.3 ± 2.4 after 12 months, respectively (p < 0.05). The total score of the interstitial cystitis symptom index and 24-hour urinary frequency demonstrated a significant sustained decrease from the baseline. Two responders, who received an additional course of HBO 12 and 13 months after initial treatment, respectively, did not suffer impairment for more than two years. There was one case of transient eustachian tube dysfunction and three cases of reversible exudative otitis media as a consequence of HBO treatment.</p> <p>Conclusions</p> <p>HBO is a potent treatment for PBS/IC patients resistant to conventional therapy. It was well tolerated and provided maintained amelioration of pain, urgency and urinary frequency for at least 12 months.</p

    Effects of prenatal food and micronutrient supplementation on child growth from birth to 54 months of age: a randomized trial in Bangladesh

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    <p>Abstract</p> <p>Background</p> <p>There is a lack of information on the optimal timing of food supplementation to malnourished pregnant women and possible combined effects of food and multiple micronutrient supplementations (MMS) on their offspring's growth. We evaluated the effects of prenatal food and micronutrient interventions on postnatal child growth. The hypothesis was that prenatal MMS and early invitation to food supplementation would increase physical growth in the offspring during 0-54 months and a combination of these interventions would further improve these outcomes.</p> <p>Methods</p> <p>In the large, randomized MINIMat trial (Maternal and Infant Nutrition Interventions in Matlab), Bangladesh, 4436 pregnant women were enrolled between November 2001 and October 2003 and their children were followed until March 2009. Participants were randomized into six groups comprising 30 mg Fe and 400 μg folic acid (Fe30F), 60 mg Fe and 400 μg folic acid (Fe60F) or MMS combined with either an early (immediately after identification of pregnancy) or a later usual (at the time of their choosing, i.e., usual care in this community) program invitation to food supplementation. The anthropometry of 3267 children was followed from birth to 54 months, and 2735 children were available for analysis at 54 months.</p> <p>Results</p> <p>There were no differences in characteristics of mothers and households among the different intervention groups. The average birth weight was 2694 g and birth length was 47.7 cm, with no difference among intervention groups. Early invitation to food supplementation (in comparison with usual invitation) reduced the proportion of stunting from early infancy up to 54 months for boys (p = 0.01), but not for girls (p = 0.31). MMS resulted in more stunting than standard Fe60F (p = 0.02). There was no interaction between the food and micronutrient supplementation on the growth outcome.</p> <p>Conclusions</p> <p>Early food supplementation in pregnancy reduced the occurrence of stunting during 0-54 months in boys, but not in girls, and prenatal MMS increased the proportion of stunting in boys. These effects on postnatal growth suggest programming effects in early fetal life.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN16581394">ISRCTN16581394</a></p

    Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters

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    Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the formation of massive star clusters, which includes several episodes of star formation. While this provides an explanation for several features of globular clusters, including the second parameter problem, it also opens new perspectives about the relation between globular clusters and the halo of our Galaxy, and by extension of all populations with a high specific frequency of globular clusters, such as, e.g., giant elliptical galaxies. We review progress in this area, focusing on the most recent studies. Several points remain to be properly understood, in particular those concerning the nature of the polluters producing the abundance pattern in the clusters and the typical timescale, the range of cluster masses where this phenomenon is active, and the relation between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review

    Measles and Rubella Incidence and Molecular Epidemiology in Senegal: Temporal and Regional Trends during Twelve Years of National Surveillance, 2010-2021.

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    We investigated the epidemiology of measles and rubella infections in Senegal based on data from twelve consecutive years of laboratory-based surveillance (2010-2021) and conducted phylogenetic analyses of circulating measles viruses. Sera from measles-suspected cases were collected and tested for measles and rubella-specific IgM antibodies using enzyme-linked immunosorbent assays (ELISA). Throat swabs were collected from patients with clinically diagnosed measles for confirmation by reverse-transcription polymerase chain reaction (RT-PCR) and viral genotyping. Among 8082 laboratory-tested specimens from measles-suspected cases, serological evidence of measles and rubella infection was confirmed in 1303/8082 (16.1%) and 465/6714 (6.9%), respectively. The incidence of rubella is now low-0.8 (95% CI 0.4-1.3) cases per million people in 2021-whereas progress towards measles pre-elimination targets (&lt;1.0 case per million people per year) appears to have stalled; there were 10.8 (95% CI 9.3-12.5) cases per million people in 2021. Phylogenetic analyses revealed that all Senegalese measles strains belonged to genotype B3. The rubella virus sequence obtained in this study was consistent with genotype 1C. Our national surveillance data suggest that despite their low incidence both measles and rubella remain endemic in Senegal with a concerning stagnation in the decline of measles infections that represents a significant challenge to the goal of regional elimination

    Training in childhood obesity management in the United States: a survey of pediatric, internal medicine-pediatrics and family medicine residency program directors

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    <p>Abstract</p> <p>Background</p> <p>Information about the availability and effectiveness of childhood obesity training during residency is limited.</p> <p>Methods</p> <p>We surveyed residency program directors from pediatric, internal medicine-pediatrics (IM-Peds), and family medicine residency programs between September 2007 and January 2008 about childhood obesity training offered in their programs.</p> <p>Results</p> <p>The response rate was 42.2% (299/709) and ranged by specialty from 40.1% to 45.4%. Overall, 52.5% of respondents felt that childhood obesity training in residency was extremely important, and the majority of programs offered training in aspects of childhood obesity management including prevention (N = 240, 80.3%), diagnosis (N = 282, 94.3%), diagnosis of complications (N = 249, 83.3%), and treatment (N = 242, 80.9%). However, only 18.1% (N = 54) of programs had a formal childhood obesity curriculum with variability across specialties. Specifically, 35.5% of IM-Peds programs had a formal curriculum compared to only 22.6% of pediatric and 13.9% of family medicine programs (p < 0.01). Didactic instruction was the most commonly used training method but was rated as only somewhat effective by 67.9% of respondents using this method. The most frequently cited significant barrier to implementing childhood obesity training was competing curricular demands (58.5%).</p> <p>Conclusions</p> <p>While most residents receive training in aspects of childhood obesity management, deficits may exist in training quality with a minority of programs offering a formal childhood obesity curriculum. Given the high prevalence of childhood obesity, a greater emphasis should be placed on development and use of effective training strategies suitable for all specialties training physicians to care for children.</p

    Yeast Methylotrophy and Autophagy in a Methanol-Oscillating Environment on Growing Arabidopsis thaliana Leaves

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    The yeast Candida boidinii capable of growth on methanol proliferates and survives on the leaves of Arabidopsis thaliana. The local methanol concentration at the phyllosphere of growing A. thaliana exhibited daily periodicity, and yeast cells responded by altering both the expression of methanol-inducible genes and peroxisome proliferation. Even under these dynamically changing environmental conditions, yeast cells proliferated 3 to 4 times in 11 days. Among the C1-metabolic enzymes, enzymes in the methanol assimilation pathway, but not formaldehyde dissimilation or anti-oxidizing enzymes, were necessary for yeast proliferation at the phyllosphere. Furthermore, both peroxisome assembly and pexophagy, a selective autophagy pathway that degrades peroxisomes, were necessary for phyllospheric proliferation. Thus, the present study sheds light on the life cycle and physiology of yeast in the natural environment at both the molecular and cellular levels
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