Integration of Geographical Information Systems and Geophysical Applications with Distributed Computing Technologies.

Science.gov (United States)

Pierce, M. E.; Aktas, M. S.; Aydin, G.; Fox, G. C.; Gadgil, H.; Sayar, A.

2005-12-01

We examine the application of Web Service Architectures and Grid-based distributed computing technologies to geophysics and geo-informatics. We are particularly interested in the integration of Geographical Information System (GIS) services with distributed data mining applications. GIS services provide the general purpose framework for building archival data services, real time streaming data services, and map-based visualization services that may be integrated with data mining and other applications through the use of distributed messaging systems and Web Service orchestration tools. Building upon on our previous work in these areas, we present our current research efforts. These include fundamental investigations into increasing XML-based Web service performance, supporting real time data streams, and integrating GIS mapping tools with audio/video collaboration systems for shared display and annotation.

Geographic Distribution of CT, MRI and PET Devices in Japan: A Longitudinal Analysis Based on National Census Data.

Science.gov (United States)

Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

2015-01-01

Japan has the most CT and MRI scanners per unit population in the world; however, the geographic distribution of these technologies is currently unknown. Moreover, nothing is known of the cause-effect relationship between the number of diagnostic imaging devices and their geographic distribution. Data on the number of CT, MRI and PET devices and that of their utilizations in all 1829 municipalities of Japan was generated, based on the Static Survey of Medical Institutions conducted by the government. The inter-municipality equity of the number of devices or utilizations was evaluated with Gini coefficient. Between 2005 and 2011, the number of CT, MRI and PET devices in Japan increased by 47% (8789 to 12945), 19% (5034 to 5990) and 70% (274 to 466), respectively. Gini coefficient of the number of devices was largest for PET and smallest for CT (p for PET-MRI difference geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force.

Measuring Geographic Distribution of Economic Activity in Nigeria ...

African Journals Online (AJOL)

Measuring Geographic Distribution of Economic Activity in Nigeria Using Gross Domestic Product. ... and environmental factors in planning. There is need for adequate understanding of spatial pattern and centrographic analysis of economic activity to support evidence based economic and regional development policies.

Veterans Affairs Geographic Distribution of Expenditures FY07 by State and County

Data.gov (United States)

Department of Veterans Affairs — The Geographic Distribution of VA Expenditures (GDX) is an annual report that shows estimated VA expenditures for major programmatic areas by geographic area (state,...

Veterans Affairs Geographic Distribution of Expenditures FY08 by State and County

Data.gov (United States)

Department of Veterans Affairs — The Geographic Distribution of VA Expenditures (GDX) is an annual report that shows estimated VA expenditures for major programmatic areas by geographic area (state,...

Geographic distribution of hospital beds throughout China: a county-level econometric analysis.

Science.gov (United States)

Pan, Jay; Shallcross, David

2016-11-08

Geographical distribution of healthcare resources is an important dimension of healthcare access. Little work has been published on healthcare resource allocation patterns in China, despite public equity concerns. Using national data from 2043 counties, this paper investigates the geographic distribution of hospital beds at the county level in China. We performed Gini coefficient analysis to measure inequalities and ordinary least squares regression with fixed provincial effects and additional spatial specifications to assess key determinants. We found that provinces in west China have the least equitable resource distribution. We also found that the distribution of hospital beds is highly spatially clustered. Finally, we found that both county-level savings and government revenue show a strong positive relationship with county level hospital bed density. We argue for more widespread use of disaggregated, geographical data in health policy-making in China to support the rational allocation of healthcare resources, thus promoting efficiency and equity.

Modelling the geographic distribution of wind power and the impact on transmission needs

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2003-01-01

Through energy systems modelling, transmission systems modelling and geographical modelling, the article examines the sensitivity of the response of the transmission system to the geographic distributions of wind power and in particular the sensitivity of the results to the accuracy...... of the distributed modelled. The results show that accuracy of the geographic modelling while important for the analysis of specific single transmission lines is not important for the analysis of the general response of the transmission system. The analyses thus corroborate previous analyses that demonstrated...

Limited geographic distribution of the novel cyclovirus CyCV-VN.

Science.gov (United States)

Le, Van Tan; de Jong, Menno D; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F L; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H Rogier

2014-02-05

A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS infections in northern Vietnam, Cambodia, Nepal and The Netherlands were screened for the presence of CyCV-VN but all were negative. Sequence comparison and phylogenetic analysis between CyCV-VN and another novel cyclovirus recently identified in CSF from Malawian patients indicated that these represent distinct cycloviral species, albeit phylogenetically closely related. The data suggest that CyCV-VN has a limited geographic distribution within southern and central Vietnam. Further research is needed to determine the global distribution and diversity of cycloviruses and importantly their possible association with human disease.

Potential distribution of the endangered endemic lizard Liolaemus lutzae Mertens, 1938 (Liolaemidae: are there other suitable areas for a geographically restricted species?

Directory of Open Access Journals (Sweden)

GR. Winck

Full Text Available In this study we attempted to access further information on the geographical distribution of the endangered lizard Liolaemus lutzae, estimating its potential distribution through the maximum entropy algorithm. For this purpose, we related its points of occurrence with matrices of environmental variables. After examining the correlation between environmental matrices, we selected 10 for model construction. The main variables influencing the current geographic distribution of L. lutzae were the diurnal temperature range and altitude. The species endemism seemed to be a consequence of a reduction of the original distribution area. Alternatively, the resulting model may reflect the geographic distribution of an ancestral lineage, since the model selected areas of occurrence of the two other species of Liolaemus from Brazil (L. arambarensis and L. occipitalis, all living in sand dune habitats and having psamophilic habits. Due to the high loss rate of habitat occupied by the species, the conservation and recovery of the remaining areas affected by human actions is essential.

Spatially-explicit estimation of geographical representation in large-scale species distribution datasets.

Science.gov (United States)

Kalwij, Jesse M; Robertson, Mark P; Ronk, Argo; Zobel, Martin; Pärtel, Meelis

2014-01-01

Much ecological research relies on existing multispecies distribution datasets. Such datasets, however, can vary considerably in quality, extent, resolution or taxonomic coverage. We provide a framework for a spatially-explicit evaluation of geographical representation within large-scale species distribution datasets, using the comparison of an occurrence atlas with a range atlas dataset as a working example. Specifically, we compared occurrence maps for 3773 taxa from the widely-used Atlas Florae Europaeae (AFE) with digitised range maps for 2049 taxa of the lesser-known Atlas of North European Vascular Plants. We calculated the level of agreement at a 50-km spatial resolution using average latitudinal and longitudinal species range, and area of occupancy. Agreement in species distribution was calculated and mapped using Jaccard similarity index and a reduced major axis (RMA) regression analysis of species richness between the entire atlases (5221 taxa in total) and between co-occurring species (601 taxa). We found no difference in distribution ranges or in the area of occupancy frequency distribution, indicating that atlases were sufficiently overlapping for a valid comparison. The similarity index map showed high levels of agreement for central, western, and northern Europe. The RMA regression confirmed that geographical representation of AFE was low in areas with a sparse data recording history (e.g., Russia, Belarus and the Ukraine). For co-occurring species in south-eastern Europe, however, the Atlas of North European Vascular Plants showed remarkably higher richness estimations. Geographical representation of atlas data can be much more heterogeneous than often assumed. Level of agreement between datasets can be used to evaluate geographical representation within datasets. Merging atlases into a single dataset is worthwhile in spite of methodological differences, and helps to fill gaps in our knowledge of species distribution ranges. Species distribution

Application of a random walk model to geographic distributions of animal mitochondrial DNA variation.

Science.gov (United States)

Neigel, J E; Avise, J C

1993-12-01

In rapidly evolving molecules, such as animal mitochondrial DNA, mutations that delineate specific lineages may not be dispersed at sufficient rates to attain an equilibrium between genetic drift and gene flow. Here we predict conditions that lead to nonequilibrium geographic distributions of mtDNA lineages, test the robustness of these predictions and examine mtDNA data sets for consistency with our model. Under a simple isolation by distance model, the variance of an mtDNA lineage's geographic distribution is expected be proportional to its age. Simulation results indicated that this relationship is fairly robust. Analysis of mtDNA data from natural populations revealed three qualitative distributional patterns: (1) significant departure of lineage structure from equilibrium geographic distributions, a pattern exhibited in three rodent species with limited dispersal; (2) nonsignificant departure from equilibrium expectations, exhibited by two avian and two marine fish species with potentials for relatively long-distance dispersal; and (3) a progression from nonequilibrium distributions for younger lineages to equilibrium distributions for older lineages, a condition displayed by one surveyed avian species. These results demonstrate the advantages of considering mutation and genealogy in the interpretation of mtDNA geographic variation.

Geographic distribution of Aedes aegypti and Aedes albopictus collected from used tires in Vietnam.

Science.gov (United States)

Higa, Yukiko; Yen, Nguyen Thi; Kawada, Hitoshi; Son, Tran Hai; Hoa, Nguyen Thuy; Takagi, Masahiro

2010-03-01

The spatial distribution of Aedes aegypti and Aedes albopictus in environmental and geographical zones, e.g., urban-rural, coastal-mountainous, and north-south, was investigated throughout Vietnam. Immature stages were collected from used tires along roads. The effects of regions, seasons, and the degree of urbanization on the density and the frequency were statistically analyzed. Aedes aegypti predominated in the southern and central regions, while Ae. albopictus predominated in the northern region, which may be related to climatic conditions (temperature and rainfall). Larval collection from used tires may be suitable to assess rapidly the current distribution of dengue mosquitoes for estimating health risks and implementing vector control measures.

Formation and distribution of international tourism flows in geographical space

Directory of Open Access Journals (Sweden)

Oleksandr Korol

2017-10-01

Full Text Available Properties of geographical space that are of key importance for international tourism, as length and discreteness, are analyzed in the article. Length makes tourists cover distances, whereas discreteness manifests itself in spatial heterogeneity. Tourism in conditions of homogeneous space is vain. That is, heterogeneity brings sense to travels as well as determines their direction. So, the effect of geographical space’s length and spatial heterogeneity on formation and distribution of tourism flows is assessed, international tourism’s geographical essence is disclosed also. Apperception of geographical space in usual environment and its effect on tourist’s original motives are described. Following the bases of behaviorism, the tourism original motives, in particular those for migration, comfort, contrast and aesthetics are substantiated. The motive for migration is a kind of “pushing” tourists outside their usual environment. To stop all fears that may cause anxiety in destination, the latter should guarantee satisfaction of those human needs which A. Maslow refers to as basic needs. The necessity to satisfy these needs forms in tourists the motive for comfort. Closely located destinations in neighboring countries can be of little difference form usual environment. Driven by the motive for contrast, tourists aspire to visit places that totally differ from their usual environment, and contrast (are exotic to it. Thus, the motive for contrast seemingly “pulls” the tourists up to certain (exotic destinations. Finally, following the considered spatial specificities of land surface and tourist-driving original motives, a conceptual model of formation and distribution of international tourism flows in geographical space is developed.

[Geographic distribution of avoidable mortality in the community of Valencia (1975-1990)].

Science.gov (United States)

Ros, X A; Bayo Vila, A; Alfonso Sánchez, J L; Cortina Greus, P; Chana González, P; Sáiz Sánchez, C

1996-04-20

Avoidable mortality (AM) has been proposed as the indicator of the quality and the efficacy of health care services and a parameter useful to distribute health care resources. The aim of this study was to analyze the size and geographic variability of AM in the Community of Valencia, Spain (1975-1990). The causes of AM were analyzed by the classification of Holland divided into indicators of medical care (IMC) and indicators on national health care policy (INHCP) in addition to the causes of the Charlton classification. Standard rates for Spain and the European Community, the rate of masculinity and contribution to total mortality were calculated. Geographic distribution by areas and provinces was analyzed by the rate of standardized mortality. According to the Holland classification AM was 30% of the deaths from 5 to 64 years of age. Out of these cases, 18.5% corresponded to INHCP and 11.1% to IMC. According to the Charlton classification, this percentage was 3.6%. A considerable variation was observed among the 20 areas analyzed due to many causes. The geographic distribution by groups (IMC, INHCP and the Charlton classification) is quite homogeneous. The worse results corresponded to the city of Valencia and to the area 21 (area of the city of Alicante). A great variation was found in the results regarding geographic distribution for individual causes of death while the distribution was quite homogeneous for all of the groups of mortality with the worst results being observed in large urban centers.

Reptiles of Chubut province, Argentina: richness, diversity, conservation status and geographic distribution maps

Science.gov (United States)

Minoli, Ignacio; Morando, Mariana; Avila, Luciano Javier

2015-01-01

Abstract An accurate estimation of species and population geographic ranges is essential for species-focused studies and conservation and management plans. Knowledge of the geographic distributions of reptiles from Patagonian Argentina is in general limited and dispersed over manuscripts from a wide variety of topics. We completed an extensive review of reptile species of central Patagonia (Argentina) based on information from a wide variety of sources. We compiled and checked geographic distribution records from published literature and museum records, including extensive new data from the LJAMM-CNP (CENPAT-CONICET) herpetological collection. Our results show that there are 52 taxa recorded for this region and the highest species richness was seen in the families Liolaemidae and Dipsadidae with 31 and 10 species, respectively. The Patagónica was the phytogeographic province most diverse in species and Phymaturus was the genus of conservation concern most strongly associated with it. We present a detailed species list with geographical information, richness species, diversity analyses with comparisons across phytogeographical provinces, conservation status, taxonomic comments and distribution maps for all of these taxa. PMID:25931966

Epidemiology and geographical distribution of enteric protozoan infections in Sydney, Australia

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Stephanie Fletcher

2014-07-01

Full Text Available Background. Enteric protozoa are associated with diarrhoeal illnesses in humans; however there are no recent studies on their epidemiology and geographical distribution in Australia. This study describes the epidemiology of enteric protozoa in the state of New South Wales and incorporates spatial analysis to describe their distribution. Design and methods. Laboratory and clinical records from four public hospitals in Sydney for 910 patients, who tested positive for enteric protozoa over the period January 2007-December 2010, were identified, examined and analysed. We selected 580 cases which had residence post code data available, enabling us to examine the geographic distribution of patients, and reviewed the clinical data of 252 patients to examine possible links between protozoa, demographic and clinical features. Results. Frequently detected protozoa were Blastocystis spp. (57%, Giardia intestinalis (27% and Dientamoeba fragilis (12%. The age distribution showed that the prevalence of protozoa decreased with age up to 24 years but increasing with age from 25 years onwards. The geographic provenance of the patients indicates that the majority of cases of Blastocystis (53.1% are clustered in and around the Sydney City Business District, while pockets of giardiasis were identified in regional/rural areas. The distribution of cases suggests higher risk of protozoan infection may exist for some communities. Conclusions. These findings provide useful information for policy makers to design and tailor interventions to target high risk communities. Follow-up investigation into the risk factors for giardiasis in regional/rural area is needed.

[Geographic distribution of supportive care for disabled young people].

Science.gov (United States)

Bourgarel, Sophie; Piteau-Delord, Monique

2013-01-01

To analyse the logic for the distribution of home care services for disabled children (SESSAD) in a context of under-equipment. Questionnaire-based survey of 75 units (82% of the region's SESSAD units) concerning patient transport. Equipment and transport mapping. Support units for disabled children are often set up in the housing facilities that contributed to their creation. These sites are sometimes situated a long way from densely populated regions, thereby generating unnecessary travel times and expenses. Chronic under-equipment makes these sites viable, as the various units are always full, despite their distance from the children for whom they provide support. Mapping illustrates the extensive recruitment zones overlapping several units managing similar patients. The major revision of accreditation of these units, planned for 2017, could lead to redefinition of geographical zones of accreditations. New unit opening procedures based on ARS calls for tenders may help to improve the geographical distribution of this supportive care.

FEATURES OF THE GEOGRAPHICAL DISTRIBUTION OF TERRESTRIAL MOLLUSCS IN THE CAUCASUS

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M. Z. Magomedova

2015-01-01

Full Text Available Aim. High population, high proliferation rates, a large species diversity, low mobility and small ability to overcome geographic barriers, ease of collecting material and sensitive response to changes in the external environment makes this group a convenient object of biogeographic and ecological research. Methods. The inventory of Caucasian ground malacofauna made it possible to make a complete list of species; their characteristics were determined by the geographical distribution of major natural regions of the Caucasus. Results. The comparative analysis of the geographical distribution of terrestrial molluscs on key areas of the Caucasus showed that among the 352 species belonging to 140 genera of 36 families, most richly represented Western Caucasus, which accounts for 51% or 181 species from 80 genera of 20 families, while the share of Armenian, Eastern and Central Caucasus accounts for 35-37%. Talysh, in turn, is characterized by the presence of only 11% of the species composition of the Caucasian land mollusc. Caucasus limited in distribution among the analyzed species is 72% or 255 species belonging to 104 genera of 24 families. Conclusion. The results prove the species diversity of the different regions of theCaucasus and could serve as the basis to reconsider the possible ways of formation of fauna of the region discussed. 

Modelling grid losses and the geographic distribution of electricity generation

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

In Denmark more than 40% of the electricity consumption is covered by geographically scattered electricity sources namely wind power and local CHP (cogeneration of heat and power) plants. This causes problems in regard to load balancing and possible grid overloads. The potential grid problems...... and methods for solving these are analysed in this article on the basis of energy systems analyses, geographic distribution of consumption and production and grid load-flow analyses. It is concluded that by introducing scattered load balancing using local CHP plants actively and using interruptible loads...

Current distribution tomography for determination of internal current density distributions

International Nuclear Information System (INIS)

Gailey, P.C.

1993-01-01

A method is presented for determination of current densities inside a cylindrical object using measurements of the magnetic fields outside the object. The cross section of the object is discretized with the current assumed constant over each defined region. Magnetic fields outside the object are related to the internal current densities through a geometry matrix which can be inverted to yield a solution for the current densities in terms of the measured fields. The primary limitation of this technique results from singularities in the geometry matrix that arise due to cylindrical symmetry of the problem. Methods for circumventing the singularities to obtain information about the distribution of current densities are discussed. This process of current distribution tomography is designed to determine internal body current densities using measurements of the external magnetic field distribution. It is non-invasive, and relatively simple to implement. Although related to a more general study of magnetic imaging which has been used to investigate endogenous currents in the brain and other parts of the body, it is restricted to currents either applied directly or induced by exposure to an external field. The research is related to public concern about the possibility of health effects resulting from exposure to power frequency electric and magnetic fields

Analysis Of Educational Services Distribution-Based Geographic Information System GIS

Directory of Open Access Journals (Sweden)

Waleed Lagrab

2015-03-01

Full Text Available Abstract This study analyzes the spatial distribution of kindergarten facilities in the study area based on the Geographic Information Systems GIS in order to test an efficiency of GIS technology to redistribute the existing kindergarten and choose the best location in the future and applying the standard criteria for selecting the suitable locations for kindergarten. To achieve this goal the data and information are collected via interviews and comprehensive statistics on the education facilities in Mukalla districts in YEMEN which contributed to building a geographic database for the study area. After that the Kindergarten spatial patterns are analyzed in terms of proximity to each other and used near some other land in the surrounding area such as streets highways factories etc. Also measures the concentration dispersion clustering and distribution direction for the kindergarten this study showed the effectiveness of the GIS for spatial data analysis. One of the most important finding that most of the Kindergarten was established in Mukalla city did not take into account the criteria that set by the authorities. Furthermore almost district suffers from a shortage in the number of kindergarten and pattern of distribution of those kindergartens dominated by spatial dispersed.

Geographical distribution and eco-adaptability of calligonum l. in tarim basin

International Nuclear Information System (INIS)

Liu, N.; Guan, K.; Feng, Y.

2017-01-01

Global climate fluctuations have profoundly affected the current distribution patterns and created opportunities and challenges for the survival and development of species. Studies on geographical distribution and eco-adaptability are necessary for both biodiversity conservation and sustainable biological resource utilization. In this study, we focus on five species of Calligonum in Tarim Basin, i.e. Calligonum roborovskii, C. kurlaense, C. yengisaricum, C. juochiangense and C. taklimakanense to confirm the distribution range by carrying out field population survey, along with the studies of herbarium specimen and relevant literature and also to find out the associations between the five species, distribution correlated with climate and soil characteristics through the mean variance analysis and principal component analysis. The results of the study were as follows: (1) C. roborovskii was widely distributed in Tarim Basin, but C. kurlaense, C. yengisaricum, C. juochiangense and C. taklimakanense have narrow distribution. The distribution areas of four latter species were overlapping with that of C. roborovskii showing sympatric distribution. (2) All the five species belonged to the warm and arid zone. The adaptability of C. roborovskii to moisture was higher, that of C. juochiangense and C. taklimakanense which grew in more arid areas than that of C. kurlaense and C. yengisaricum, had stronger drought tolerance. The soil type of the five species main was brown desert soil with high salinity, alkaline, and low content of organic matter in the top soil. (3) Low temperature, moisture factor, salinity and alkalinity were the main reasons leading to the different distribution of the four narrow distributed species. (4) The main factors limiting the distribution range of the five species were high temperature and moisture factor, followed by soil properties. For C. juochiangense and C. taklimakanense, moisture factor was much stronger than temperature. The results of the

Limited geographic distribution of the novel cyclovirus CyCV-VN

NARCIS (Netherlands)

Le, Van Tan; de Jong, Menno D.; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F. L.; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E.; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H. Rogier

2014-01-01

A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS

The geographic distribution patterns of HIV-, HCV- and co-infections among drug users in a national methadone maintenance treatment program in Southwest China.

Science.gov (United States)

Zhou, Yi-Biao; Liang, Song; Wang, Qi-Xing; Gong, Yu-Han; Nie, Shi-Jiao; Nan, Lei; Yang, Ai-Hui; Liao, Qiang; Song, Xiu-Xia; Jiang, Qing-Wu

2014-03-10

HIV-, HCV- and HIV/HCV co-infections among drug users have become a rapidly emerging global public health problem. In order to constrain the dual epidemics of HIV/AIDS and drug use, China has adopted a methadone maintenance treatment program (MMTP) since 2004. Studies of the geographic heterogeneity of HIV and HCV infections at a local scale are sparse, which has critical implications for future MMTP implementation and health policies covering both HIV and HCV prevention among drug users in China. This study aimed to characterize geographic patterns of HIV and HCV prevalence at the township level among drug users in a Yi Autonomous Prefecture, Southwest of China. Data on demographic and clinical characteristics of all clients in the 11 MMTP clinics of the Yi Autonomous Prefecture from March 2004 to December 2012 were collected. A GIS-based geographic analysis involving geographic autocorrelation analysis and geographic scan statistics were employed to identify the geographic distribution pattern of HIV-, HCV- and co-infections among drug users. A total of 6690 MMTP clients was analyzed. The prevalence of HIV-, HCV- and co-infections were 25.2%, 30.8%, and 10.9% respectively. There were significant global and local geographic autocorrelations for HIV-, HCV-, and co-infection. The Moran's I was 0.3015, 0.3449, and 0.3155, respectively (P geographic autocorrelation analysis and the geographic scan statistical analysis showed that HIV-, HCV-, and co-infections in the prefecture exhibited significant geographic clustering at the township level. The geographic distribution pattern of each infection group was different. HIV-, HCV-, and co-infections among drug users in the Yi Autonomous Prefecture all exhibited substantial geographic heterogeneity at the township level. The geographic distribution patterns of the three groups were different. These findings imply that it may be necessary to inform or invent site-specific intervention strategies to better devote currently

Inorganic chemical quality of European tap-water: 2. Geographical distribution

International Nuclear Information System (INIS)

Flem, B.; Reimann, C.; Birke, M.; Banks, D.; Filzmoser, P.; Frengstad, B.

2015-01-01

Highlights: • European scale comparison of tap water. • 579 tap water samples have been analyses for more than 60 parameters. • Chemical geographical distribution. • Water treatment processes. • Importance of geology on tap water quality. - Abstract: 579 tap water samples were collected at the European scale and analysed at a single laboratory for more than 60 parameters. This dataset is analysed here in terms of the spatial and national distribution of the analysed inorganic chemical parameters. The distribution of most parameters is controlled by various artificial and natural factors (land use, distribution network, water source and treatment, geographical location and geology). The distribution of nitrate can be interpreted in terms of land use and climate. Water treatment affects the distribution of phosphorus in tap water; especially the policy of adding phosphate to potable water in the UK to suppress plumbosolvency. The distribution of alkalinity, Ca, Mg, Sr and Li appears to reflect both water source (low in surface waters) and the geological contrast between base-poor crystalline rock terrains and carbonate rich sedimentary rock. The Scandinavian nations’ tap water shows the highest concentrations of most of the rare earth elements, probably reflecting their geological availability and mobility in low pH raw water sources. The distribution of fluoride, uranium and arsenic also appear to exhibit geological and source (groundwater versus surface water) controls. Hungary returns several high As results, which may reflect As-rich reducing groundwaters of the Pannonian basin. Much Estonian tap water reflects a very specific hydrochemical environment, namely Palaeozoic near-coastal aquifers, which yield deep, reducing or saline groundwater (possibly influenced by marine intrusion), enriched in Ba, B, Br − , Cl − , Eu, F − , I, Li, K, Mn and Na

Angiostrongylus spp. in the Americas: geographical and chronological distribution of definitive hosts versus disease reports.

Science.gov (United States)

Valente, Romina; Robles, Maria Del Rosario; Navone, Graciela T; Diaz, Julia I

2018-03-01

Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the current distribution of Angiostrongylus species in America

Angiostrongylus spp. in the Americas: geographical and chronological distribution of definitive hosts versus disease reports

Science.gov (United States)

Valente, Romina; Robles, Maria del Rosario; Navone, Graciela T; Diaz, Julia I

2018-01-01

BACKGROUND Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. OBJECTIVES In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. METHODS The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). FINDINGS Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. MAIN CONCLUSIONS Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the

Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

Directory of Open Access Journals (Sweden)

Plasencia–Vázquez, A. H.

2014-12-01

Full Text Available The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.

The Geographic Information Grid System Based on Mobile Agent

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

We analyze the deficiencies of current application systems, and discuss the key requirements of distributed Geographic Information service (GIS). We construct the distributed GIS on grid platform. Considering the flexibility and efficiency, we integrate the mobile agent technology into the system. We propose a new prototype system, the Geographic Information Grid System (GIGS) based on mobile agent. This system has flexible services and high performance, and improves the sharing of distributed resources. The service strategy of the system and the examples are also presented.

The Geographical Aspect of Flexibility in Distribution Grids

DEFF Research Database (Denmark)

Kouzelis, Konstantinos; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2015-01-01

, the reason for this is that flexibility is a multidimensional commodity. It can be associated with a unit or a system, a time-frame and a time-horizon of measuring it, its power magnitude and ramp rate, its energy shifting capability, its location and several other features. In this paper, the locational...... aggregation taking into account the distribution grid's radial structure. By aggregating the flexibility in this manner, different geographical points for offering it are defined. Through an illustrative market scenario, it is demonstrated how utilities might profit from their local flexibility by assisting...

Geographic distributions and ecology of ornamental Curcuma (Zingiberaceae) in Northeastern Thailand.

Science.gov (United States)

Khumkratok, Sutthira; Boongtiang, Kriangsuk; Chutichudet, Prasit; Pramaul, Pairot

2012-10-01

The genus Curcuma is a very important economic plant. Members of this genus were used as food, medicine and ornament plants. The objectives of this study were to examine the geographic distributions and ecological conditions in the natural habitats of Curcuma in Northeastern Thailand. Species diversity was examined using the line transect method. Ecological conditions of the species were examined using a sampling plot of 20 x 20 m. A total of five species were found including Curcuma angustifolia Roxb., C. alismatifolia Gagnep., C. gracillima Gagnep., C. parviflora Wall. and C. rhabdota. These species were in an altitudinal range between 290 m and 831 m above sea level. Four species (C. angustifolia, C. alismatifolia, C. gracillima and C. rhabdota) were distributed in open gaps in dry dipterocarp forest. One species, C. parviflora was found in the contact zone between dry dipterocarp and bamboo (Gigantochloa sp.) forest. C. rhabdota was found only in a habitat with high humidity and shading along the Thailand-Lao PDR border. Significant ecological conditions of the natural habitats of these Curcuma species were identified. Altitude is the most important factor when determining the geographic distributions of these Curcuma species in Northeastern Thailand.

Predicting the geographical distribution of two invasive termite species from occurrence data.

Science.gov (United States)

Tonini, Francesco; Divino, Fabio; Lasinio, Giovanna Jona; Hochmair, Hartwig H; Scheffrahn, Rudolf H

2014-10-01

Predicting the potential habitat of species under both current and future climate change scenarios is crucial for monitoring invasive species and understanding a species' response to different environmental conditions. Frequently, the only data available on a species is the location of its occurrence (presence-only data). Using occurrence records only, two models were used to predict the geographical distribution of two destructive invasive termite species, Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki. The first model uses a Bayesian linear logistic regression approach adjusted for presence-only data while the second one is the widely used maximum entropy approach (Maxent). Results show that the predicted distributions of both C. gestroi and C. formosanus are strongly linked to urban development. The impact of future scenarios such as climate warming and population growth on the biotic distribution of both termite species was also assessed. Future climate warming seems to affect their projected probability of presence to a lesser extent than population growth. The Bayesian logistic approach outperformed Maxent consistently in all models according to evaluation criteria such as model sensitivity and ecological realism. The importance of further studies for an explicit treatment of residual spatial autocorrelation and a more comprehensive comparison between both statistical approaches is suggested.

What influences national and foreign physicians' geographic distribution? An analysis of medical doctors' residence location in Portugal.

Science.gov (United States)

Russo, Giuliano; Ferrinho, Paulo; de Sousa, Bruno; Conceição, Cláudia

2012-07-02

The debate over physicians' geographical distribution has attracted the attention of the economic and public health literature over the last forty years. Nonetheless, it is still to date unclear what influences physicians' location, and whether foreign physicians contribute to fill the geographical gaps left by national doctors in any given country. The present research sets out to investigate the current distribution of national and international physicians in Portugal, with the objective to understand its determinants and provide an evidence base for policy-makers to identify policies to influence it. A cross-sectional study of physicians currently registered in Portugal was conducted to describe the population and explore the association of physician residence patterns with relevant personal and municipality characteristics. Data from the Portuguese Medical Council on physicians' residence and characteristics were analysed, as well as data from the National Institute of Statistics on municipalities' population, living standards and health care network. Descriptive statistics, chi-square tests, negative binomial and logistic regression modelling were applied to determine: (a) municipality characteristics predicting Portuguese and International physicians' geographical distribution, and; (b) doctors' characteristics that could increase the odds of residing outside the country's metropolitan areas. There were 39,473 physicians in Portugal in 2008, 51.1% of whom male, and 40.2% between 41 and 55 years of age. They were predominantly Portuguese (90.5%), with Spanish, Brazilian and African nationalities also represented. Population, Population's Purchasing Power, Nurses per capita and Municipality Development Index (MDI) were the municipality characteristics displaying the strongest association with national physicians' location. For foreign physicians, the MDI was not statistically significant, while municipalities' foreign population applying for residence

What influences national and foreign physicians’ geographic distribution? An analysis of medical doctors’ residence location in Portugal

Directory of Open Access Journals (Sweden)

Russo Giuliano

2012-07-01

Full Text Available Abstract Background The debate over physicians’ geographical distribution has attracted the attention of the economic and public health literature over the last forty years. Nonetheless, it is still to date unclear what influences physicians’ location, and whether foreign physicians contribute to fill the geographical gaps left by national doctors in any given country. The present research sets out to investigate the current distribution of national and international physicians in Portugal, with the objective to understand its determinants and provide an evidence base for policy-makers to identify policies to influence it. Methods A cross-sectional study of physicians currently registered in Portugal was conducted to describe the population and explore the association of physician residence patterns with relevant personal and municipality characteristics. Data from the Portuguese Medical Council on physicians’ residence and characteristics were analysed, as well as data from the National Institute of Statistics on municipalities’ population, living standards and health care network. Descriptive statistics, chi-square tests, negative binomial and logistic regression modelling were applied to determine: (a municipality characteristics predicting Portuguese and International physicians’ geographical distribution, and; (b doctors’ characteristics that could increase the odds of residing outside the country’s metropolitan areas. Results There were 39,473 physicians in Portugal in 2008, 51.1% of whom male, and 40.2% between 41 and 55 years of age. They were predominantly Portuguese (90.5%, with Spanish, Brazilian and African nationalities also represented. Population, Population’s Purchasing Power, Nurses per capita and Municipality Development Index (MDI were the municipality characteristics displaying the strongest association with national physicians’ location. For foreign physicians, the MDI was not statistically significant

PlanetLab Europe as Geographically-Distributed Testbed for Software Development and Evaluation

Directory of Open Access Journals (Sweden)

Dan Komosny

2015-01-01

Full Text Available In this paper, we analyse the use of PlanetLab Europe for development and evaluation of geographically-oriented Internet services. PlanetLab is a global research network with the main purpose to support development of new Internet services and protocols. PlanetLab is divided into several branches; one of them is PlanetLab Europe. PlanetLab Europe consists of about 350 nodes at 150 geographically different sites. The nodes are accessible by remote login, and the users can run their software on the nodes. In the paper, we study the PlanetLab's properties that are significant for its use as a geographically distributed testbed. This includes node position accuracy, services availability and stability. We find a considerable number of location inaccuracies and a number of services that cannot be considered as reliable. Based on the results we propose a simple approach to nodes selection in testbeds for geographically-oriented Internet services development and evaluation.

[Analysis of the geographical distribution of cases of leprosy. Rio de Janeiro, 2001-2012].

Science.gov (United States)

Gracie, Renata; Peixoto, Julia Novaes de Barros; Soares, Fabiane Bertoni Dos Reis; Hacker, Mariana de Andrea Vilas-Boas

2017-05-01

Studies have demonstrated that the geographical distribution of leprosy is related to different socioeconomic factors. This article aims to study the geographical distribution of leprosy in the state of Rio de Janeiro. The cases of leprosy reported in the 2001-2012 period were mapped according to municipality. Epidemiological and socioeconomic indicators were calculated. The ArcMap program was used for the construction of maps and Earth View to calculate the Bayesian rate. It was observed that leprosy is presented in hyper-endemic levels especially in the metropolitan area. However, there is also a reduction of the detection rate in the most recent study period. In municipalities in the metropolitan region and the north western region detection in children under 15 is high, indicating an active transmission situation. In municipalities in the south-central region and especially in the coastal region, there was a high proportion of cases diagnosed with level II disability, reflecting late diagnosis. There was no linear correlation between socioeconomic indicators and leprosy rate. These results contribute to the analysis of the geographical distribution of leprosy, important for the identification of areas for resource allocation, aiming to control and eliminate the disease.

The geographical vector in distribution of genetic diversity for Clonorchis sinensis.

Science.gov (United States)

Solodovnik, Daria A; Tatonova, Yulia V; Burkovskaya, Polina V

2018-01-01

Clonorchis sinensis, the causative agent of clonorchiasis, is one of the most important parasites that inhabit countries of East and Southeast Asia. In this study, we validated the existence of a geographical vector for C. sinensis using the partial cox1 mtDNA gene, which includes a conserved region. The samples of parasite were divided into groups corresponding to three river basins, and the size of the conserved region had a strong tendency to increase from the northernmost to the southernmost samples. This indicates the availability of the geographical vector in distribution of genetic diversity. A vector is a quantity that is characterized by magnitude and direction. Geographical vector obtained in cox1 gene of C. sinensis has both these features. The reasons for the occurrence of this feature, including the influence of intermediate and definitive hosts on vector formation, and the possibility of its use for clonorchiasis monitoring are discussed. Graphical abstract ᅟ.

Reptilia, Gymnophthalmidae, Micrablepharus maximiliani (Reinhardt and Lutken, 1861: Distribution extension, new state record and geographic distribution map.

Directory of Open Access Journals (Sweden)

Moura, M. R.

2010-01-01

Full Text Available We provide records for Micrablepharus maximiliani from state of Minas Gerais and present a map representingits distribution. The record of M. maximiliani from municipality of Resplendor, Minas Gerais, represents a distributionextension of 1,050 km southern from the type locality at the municipality of Maruim, Sergipe. Others 57 new recordsare presented based on specimens housed in several Brazilian and Paraguayan herpetological collections, improving theknowledge on geographic distribution of M. maximiliani in South America.

A Heterogeneous Distributed Virtual Geographic Environment—Potential Application in Spatiotemporal Behavior Experiments

Directory of Open Access Journals (Sweden)

Shen Shen

2018-02-01

Full Text Available Due to their strong immersion and real-time interactivity, helmet-mounted virtual reality (VR devices are becoming increasingly popular. Based on these devices, an immersive virtual geographic environment (VGE provides a promising method for research into crowd behavior in an emergency. However, the current cheaper helmet-mounted VR devices are not popular enough, and will continue to coexist with personal computer (PC-based systems for a long time. Therefore, a heterogeneous distributed virtual geographic environment (HDVGE could be a feasible solution to the heterogeneous problems caused by various types of clients, and support the implementation of spatiotemporal crowd behavior experiments with large numbers of concurrent participants. In this study, we developed an HDVGE framework, and put forward a set of design principles to define the similarities between the real world and the VGE. We discussed the HDVGE architecture, and proposed an abstract interaction layer, a protocol-based interaction algorithm, and an adjusted dead reckoning algorithm to solve the heterogeneous distributed problems. We then implemented an HDVGE prototype system focusing on subway fire evacuation experiments. Two types of clients are considered in the system: PC, and all-in-one VR. Finally, we evaluated the performances of the prototype system and the key algorithms. The results showed that in a low-latency local area network (LAN environment, the prototype system can smoothly support 90 concurrent users consisting of PC and all-in-one VR clients. HDVGE provides a feasible solution for studying not only spatiotemporal crowd behaviors in normal conditions, but also evacuation behaviors in emergency conditions such as fires and earthquakes. HDVGE could also serve as a new means of obtaining observational data about individual and group behavior in support of human geography research.

[Spatial distribution of occupational disease prevalence in Guangzhou and Foshan city by geographic information system].

Science.gov (United States)

Tan, Q; Tu, H W; Gu, C H; Li, X D; Li, R Z; Wang, M; Chen, S G; Cheng, Y J; Liu, Y M

2017-11-20

Objective: To explore the occupational disease spatial distribution characteristics in Guangzhou and Foshan city in 2006-2013 with Geographic Information System and to provide evidence for making control strategy. Methods: The data on occupational disease diagnosis in Guangzhou and Foshan city from 2006 through 2013 were collected and linked to the digital map at administrative county level with Arc GIS12.0 software for spatial analysis. Results: The maps of occupational disease and Moran's spatial autocor-relation analysis showed that the spatial aggregation existed in Shunde and Nanhai region with Moran's index 1.727, -0.003. Local Moran's I spatial autocorrelation analysis pointed out the "positive high incidence re-gion" and the "negative high incidence region" during 2006~2013. Trend analysis showed that the diagnosis case increased slightly then declined from west to east, increase obviously from north to south, declined from? southwest to northeast, high in the middle and low on both sides in northwest-southeast direction. Conclusions: The occupational disease is obviously geographical distribution in Guangzhou and Foshan city. The corresponding prevention measures should be made according to the geographical distribution.

Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis.

Science.gov (United States)

Kato, Hirotomo; Gomez, Eduardo A; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

2016-07-01

A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.

Mapping the geographical distribution of lymphatic filariasis in Zambia

DEFF Research Database (Denmark)

Mwase, Enala T; Stensgaard, Anna-Sofie; Nsakashalo-Senkwe, Mutale

2014-01-01

to be an important determinant of medium-high prevalence levels. CONCLUSIONS/SIGNIFICANCE: LF was found to be surprisingly widespread in Zambia, although in most places with low prevalence. The produced maps and the identified environmental correlates of LF infection will provide useful guidance for planning...... volunteers from 108 geo-referenced survey sites across Zambia were examined for circulating filarial antigens (CFA) with rapid format ICT cards, and a map indicating the distribution of CFA prevalences in Zambia was prepared. 78% of survey sites had CFA positive cases, with prevalences ranging between 1......% and 54%. Most positive survey sites had low prevalence, but six foci with more than 15% prevalence were identified. The observed geographical variation in prevalence pattern was examined in more detail using a species distribution modeling approach to explore environmental requirements for parasite...

Analysis Of Educational Services Distribution-Based Geographic Information System GIS

OpenAIRE

Waleed Lagrab; Noura AKNIN

2015-01-01

Abstract This study analyzes the spatial distribution of kindergarten facilities in the study area based on the Geographic Information Systems GIS in order to test an efficiency of GIS technology to redistribute the existing kindergarten and choose the best location in the future and applying the standard criteria for selecting the suitable locations for kindergarten. To achieve this goal the data and information are collected via interviews and comprehensive statistics on the education facil...

Western Gulf of Mexico June 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Jun_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico April 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Apr_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Eastern Gulf of Mexico November 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Nov_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Eastern Gulf of Mexico February 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Feb_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Eastern Gulf of Mexico March 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Mar_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico October 1994 Ocean Currents, Geographic NAD83, MMS (1999)[ocean_currents_wgom_Oct_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico May 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_May_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico July 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Jul_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Western Gulf of Mexico May 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_May_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico August 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Aug_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Eastern Gulf of Mexico October 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Oct_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico August 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Aug_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Western Gulf of Mexico April 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Apr_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico September 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Sep_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico January 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Jan_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico June 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jun_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Eastern Gulf of Mexico July 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jul_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico March 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Mar_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Western Gulf of Mexico September 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Sep_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Western Gulf of Mexico February 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Feb_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico December 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Dec_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico November 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Nov_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico January 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jan_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Western Gulf of Mexico December 1994 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_Dec_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Mycobacterium tuberculosis Lineage 4 comprises globally distributed and geographically restricted sublineages

Science.gov (United States)

Coscolla, Mireia; Liu, Qingyun; Trauner, Andrej; Fenner, Lukas; Rutaihwa, Liliana; Borrell, Sonia; Luo, Tao; Gao, Qian; Kato-Maeda, Midori; Ballif, Marie; Egger, Matthias; Macedo, Rita; Mardassi, Helmi; Moreno, Milagros; Tudo Vilanova, Griselda; Fyfe, Janet; Globan, Maria; Thomas, Jackson; Jamieson, Frances; Guthrie, Jennifer L.; Asante-Poku, Adwoa; Yeboah-Manu, Dorothy; Wampande, Eddie; Ssengooba, Willy; Joloba, Moses; Henry Boom, W.; Basu, Indira; Bower, James; Saraiva, Margarida; Vaconcellos, Sidra E. G.; Suffys, Philip; Koch, Anastasia; Wilkinson, Robert; Gail-Bekker, Linda; Malla, Bijaya; Ley, Serej D.; Beck, Hans-Peter; de Jong, Bouke C.; Toit, Kadri; Sanchez-Padilla, Elisabeth; Bonnet, Maryline; Gil-Brusola, Ana; Frank, Matthias; Penlap Beng, Veronique N.; Eisenach, Kathleen; Alani, Issam; Wangui Ndung’u, Perpetual; Revathi, Gunturu; Gehre, Florian; Akter, Suriya; Ntoumi, Francine; Stewart-Isherwood, Lynsey; Ntinginya, Nyanda E.; Rachow, Andrea; Hoelscher, Michael; Cirillo, Daniela Maria; Skenders, Girts; Hoffner, Sven; Bakonyte, Daiva; Stakenas, Petras; Diel, Roland; Crudu, Valeriu; Moldovan, Olga; Al-Hajoj, Sahal; Otero, Larissa; Barletta, Francesca; Jane Carter, E.; Diero, Lameck; Supply, Philip; Comas, Iñaki; Niemann, Stefan; Gagneux, Sebastien

2016-01-01

Generalist and specialist species differ in the breadth of their ecological niche. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis Lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that Lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that while the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of Lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration. PMID:27798628

Coincidence between geographical distribution of Leptotrombidium scutellare and scrub typhus incidence in South Korea.

Directory of Open Access Journals (Sweden)

Jong Yul Roh

Full Text Available To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%, Leptotrombiduim scutellare (27.1%, Leptotrombidium palpale (8.2%, Leptotrombidium orientale (5.6%, and Neotrombicula tamiyai (1.7%. However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%, Jeollanam-Do (49.0%, and Gyeongsangnam-Do (88%, were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. L. pallidum could be another vector at all other parts of the Korean peninsula, including the eastern and northern regions that have a low level of scrub typhus incidence.

Geographical distribution of centenarians in Colombia: an analysis of three databases

Directory of Open Access Journals (Sweden)

Diego Rosselli

2017-07-01

Conclusions: Although the results are consistent with the number and geographical distribution of centenarians, some errors may be found in the date of birth stated in the records, which is the basis for estimating age in the three sources. Other factors potentially involved in the results may be physical activity, family and community support, low stress and healthy diet in these regions.

Geographic distribution of hepatitis C virus genotype 6 subtypes in Thailand.

Science.gov (United States)

Akkarathamrongsin, Srunthron; Praianantathavorn, Kesmanee; Hacharoen, Nisachol; Theamboonlers, Apiradee; Tangkijvanich, Pisit; Tanaka, Yasuhito; Mizokami, Masashi; Poovorawan, Yong

2010-02-01

The nucleotide sequence of hepatitis C virus (HCV) genotype 6 found mostly in south China and south-east Asia, displays profound genetic diversity. The aim of this study to determine the genetic variability of HCV genotype 6 (HCV-6) in Thailand and locate the subtype distribution of genotype 6 in various geographic areas. Four hundred nineteen anti-HCV positive serum samples were collected from patients residing in - the central part of the country. HCV RNA positive samples based on reverse transcriptase- polymerase chain reaction (RT-PCR) of the 5'UTR were amplified with primers specific for the core and NS5B regions. Nucleotide sequences of both regions were analyzed for the genotype by phylogenetic analysis. To determine geographic distribution of HCV-6 subtypes, a search of the international database on subtype distribution in the respective countries was conducted. Among 375 HCV RNA positive samples, 71 had HCV-6 based on phylogenetic analysis of partial core and NS5B regions. The subtype distribution in order of predominance was 6f (56%), 6n (22%), 6i (11%), 6j (10%), and 6e (1%). Among the 13 countries with different subtypes of HCV-6, most sequences have been reported from Vietnam. Subtype 6f was found exclusively in Thailand where five distinct HCV-6 subtypes are circulating. HCV-6, which is endemic in south China and south-east Asia, displays profound genetic diversity and may have evolved over a considerable period of time. (c) 2009 Wiley-Liss, Inc.

Mapping and modelling the geographical distribution of soil-transmitted helminthiases in Peninsular Malaysia: implications for control approaches

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Romano Ngui

2014-05-01

Full Text Available Soil-transmitted helminth (STH infections in Malaysia are still highly prevalent, especially in rural and remote communities. Complete estimations of the total disease burden in the country has not been performed, since available data are not easily accessible in the public domain. The current study utilised geographical information system (GIS to collate and map the distribution of STH infections from available empirical survey data in Peninsular Malaysia, highlighting areas where information is lacking. The assembled database, comprising surveys conducted between 1970 and 2012 in 99 different locations, represents one of the most comprehensive compilations of STH infections in the country. It was found that the geographical distribution of STH varies considerably with no clear pattern across the surveyed locations. Our attempt to generate predictive risk maps of STH infections on the basis of ecological limits such as climate and other environmental factors shows that the prevalence of Ascaris lumbricoides is low along the western coast and the southern part of the country, whilst the prevalence is high in the central plains and in the North. In the present study, we demonstrate that GIS can play an important role in providing data for the implementation of sustainable and effective STH control programmes to policy-makers and authorities in charge.

Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis

Science.gov (United States)

Kato, Hirotomo; Gomez, Eduardo A.; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

2016-01-01

A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas. PMID:27410039

Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis.

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Hirotomo Kato

2016-07-01

Full Text Available A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia guyanensis, L. (V. braziliensis, L. (V. naiffi, L. (V. lainsoni, and L. (Leishmania mexicana. Two dominant species, L. (V. guyanensis and L. (V. braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V. naiffi and L. (V. lainsoni were identified in Amazonian areas, and L. (L. mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V. braziliensis infection are increasing in Pacific coast areas.

Geographic distribution and ecological niche of plague in sub-Saharan Africa

DEFF Research Database (Denmark)

Neerinckx, Simon B; Peterson, Andrew T; Gulinck, Hubert

2008-01-01

Background Plague is a rapidly progressing, serious illness in humans that is likely to be fatal if not treated. It remains a public health threat, especially in sub-Saharan Africa. In spite of plague's highly focal nature, a thorough ecological understanding of the general distribution pattern...... of plague across sub-Saharan Africa has not been established to date. In this study, we used human plague data from sub-Saharan Africa for 1970-2007 in an ecological niche modeling framework to explore the potential geographic distribution of plague and its ecological requirements across Africa. Results We...... predict a broad potential distributional area of plague occurrences across sub-Saharan Africa. General tests of model's transferability suggest that our model can anticipate the potential distribution of plague occurrences in Madagascar and northern Africa. However, generality and predictive ability tests...

[Current status of the knowledge on Moroccan anophelines (Diptera: Culicidae): systematic, geographical distribution and vectorial competence].

Science.gov (United States)

Faraj, C; Ouahabi, S; Adlaoui, E; Elaouad, R

2010-10-01

This bibliographical study, based on published works, ministry of Health Reports, exploitation of the database relative to the entomological surveillance conducted in the framework of the National Malaria Control Program, as well as unpublished results obtained within the framework of the European project "Emerging disease in a changing European environment", summarizes and completes with new data current knowledge on the systematics, the distribution and the vectorial competence of moroccan anophelines. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

[Potential distribution and geographic characteristics of wild populations of Vanilla planifolia (Orchidaceae) Oaxaca, Mexico].

Science.gov (United States)

Hernandez-Ruiz, Jesús; Herrera-Cabrera, B Edgar; Delgado-Alvarado, Adriana; Salazar-Rojas, Víctor M; Bustamante-Gonzalez, Ángel; Campos-Contreras, Jorge E; Ramírez-Juarez, Javier

2016-03-01

Wild specimens of Vanilla planifolia represent a vital part of this resource primary gene pool, and some plants have only been reported in Oaxaca, Mexico. For this reason, we studied its geographical distribution within the state, to locate and describe the ecological characteristics of the areas where they have been found, in order to identify potential areas of establishment. The method comprised four stages: 1) the creation of a database with herbarium records, 2) the construction of the potential distribution based on historical herbarium records for the species, using the model of maximum entropy (MaxEnt) and 22 bioclimatic variables as predictors; 3) an in situ systematic search of individuals, based on herbarium records and areas of potential distribution in 24 municipalities, to determine the habitat current situation and distribution; 4) the description of the environmental factors of potential ecological niches generated by MaxEnt. A review of herbarium collections revealed a total of 18 records of V. planifolia between 1939 and 1998. The systematic search located 28 plants distributed in 12 sites in 95 364 Km(2). The most important variables that determined the model of vanilla potential distribution were: precipitation in the rainy season (61.9 %), soil moisture regime (23.4 %) and precipitation during the four months of highest rainfall (8.1 %). The species potential habitat was found to be distributed in four zones: wet tropics of the Gulf of Mexico, humid temperate, humid tropical, and humid temperate in the Pacific. Precipitation oscillated within the annual ranges of 2 500 to 4 000 mm, with summer rains, and winter precipitation as 5 to 10 % of the total. The moisture regime and predominating climate were udic type I (330 to 365 days of moisture) and hot humid (Am/A(C) m). The plants were located at altitudes of 200 to 1 190 masl, on rough hillsides that generally make up the foothills of mountain systems, with altitudes of 1 300 to 2 500 masl. In

Species composition and geographical distribution of Saharan scorpion fauna, Morocco

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Oulaid Touloun

2016-11-01

Full Text Available Objective: To describe the species composition of scorpions and to study its geographical distribution in Laayoune-Sakia El Hamra and Dakhla-Oued Ed Dahab regions in July 2014. Methods: To locate scorpions, the ground was examined through searching the places under the stones, rocks and in burrows. The nocturnal missions were also conducted using portable ultraviolet lamps. The scorpions were subsequently identified in the laboratory. Results: The results of the investigations in these regions showed the presence of five scorpion species, two of which Androctonus gonneti and Buthus bonito were endemic in Morocco. Conclusions: This work is allowed to complete the inventory of the studied scorpion fauna and provides some considerations on the distribution patterns in the study area.

Local knowledge, use pattern and geographical distribution of Moringa oleifera Lam. (Moringaceae) in Nigeria.

Science.gov (United States)

Popoola, Jacob O; Obembe, Olawole O

2013-11-25

All parts of Moringa oleifera are medicinally valuable with overlapping uses in treating myriads of ailments and diseases including body pains and weakness, fever, asthma, cough, blood pressure, arthritis, diabetes, epilepsy, wound, and skin infection. Moringa also has robust ability to challenge terminal diseases such as HIV/AIDs infections, chronic anemia, cancer, malaria and hemorrhage. The present study was to obtain ethnobotanical information on the use and local knowledge variation, geographical distribution, and to collect different landraces of Moringa oleifera from the different agro-ecological regions in Nigeria, for further studies. Ethnobotanical data were collected through face to face interviews, semi structured questionnaires and discussions with selected people who had knowledge about the plant. The fidelity level (FL %) and use value for different use categories of Moringa oleifera and its parts were estimated. The variation in ethnobotanical knowledge was evaluated by comparing the mean use value among ethnic, gender and age groups using sample T test. Garmi GPS was used to determine the locations (latitude and longitude) and height in different areas to assess the geographical spread of the species. Seven (7) categories of use (Food, medicine, fodder, fencing, firewood, gum and coagulant) were recorded for Moringa oleifera. Food and medicinal uses showed highest fidelity level while the leaves and the seeds were the plant parts most utilized for the same purposes. There were significant differences among the ethnic, gender and age groups regarding the ethno-botanical use value. The geographical distribution pattern shows that the Moringa oleifera is well distributed in all ecological zones of Nigeria, well adapted to the varied climatic conditions and gaining unprecedented awareness among the people. Though considered an introduced species, Moringa oleifera has found wide acceptance, recognition and usefulness among the various ethnicities in the

A Current Perspective on the Historical Geographic Distribution of the Endangered Muriquis (Brachyteles spp.): Implications for Conservation.

Science.gov (United States)

Ingberman, Bianca; Fusco-Costa, Roberto; Monteiro-Filho, Emygdio Leite de Araujo

2016-01-01

The muriqui (Brachyteles spp.), endemic to the Atlantic Forest of Brazil, is the largest primate in South America and is endangered, mainly due to habitat loss. Its distribution limits are still uncertain and need to be resolved in order to determine their true conservation status. Species distribution modeling (SDM) has been used to estimate potential species distributions, even when information is incomplete. Here, we developed an environmental suitability model for the two endangered species of muriqui (Brachyteles hypoxanthus and B. arachnoides) using Maxent software. Due to historical absence of muriquis, areas with predicted high habitat suitability yet historically never occupied, were excluded from the predicted historical distribution. Combining that information with the model, it is evident that rivers are potential dispersal barriers for the muriquis. Moreover, although the two species are environmentally separated in a large part of its distribution, there is a potential contact zone where the species apparently do not overlap. This separation might be due to either a physical (i.e., Serra da Mantiqueira mountains) or a biotic barrier (the species exclude one another). Therefore, in addition to environmental characteristics, physical and biotic barriers potentially shaped the limits of the muriqui historical range. Based on these considerations, we proposed the adjustment of their historical distributional limits. Currently only 7.6% of the predicted historical distribution of B. hypoxanthus and 12.9% of B. arachnoides remains forested and able to sustain viable muriqui populations. In addition to measurement of habitat loss we also identified areas for conservation concern where new muriqui populations might be found.

A Current Perspective on the Historical Geographic Distribution of the Endangered Muriquis (Brachyteles spp.: Implications for Conservation.

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Bianca Ingberman

Full Text Available The muriqui (Brachyteles spp., endemic to the Atlantic Forest of Brazil, is the largest primate in South America and is endangered, mainly due to habitat loss. Its distribution limits are still uncertain and need to be resolved in order to determine their true conservation status. Species distribution modeling (SDM has been used to estimate potential species distributions, even when information is incomplete. Here, we developed an environmental suitability model for the two endangered species of muriqui (Brachyteles hypoxanthus and B. arachnoides using Maxent software. Due to historical absence of muriquis, areas with predicted high habitat suitability yet historically never occupied, were excluded from the predicted historical distribution. Combining that information with the model, it is evident that rivers are potential dispersal barriers for the muriquis. Moreover, although the two species are environmentally separated in a large part of its distribution, there is a potential contact zone where the species apparently do not overlap. This separation might be due to either a physical (i.e., Serra da Mantiqueira mountains or a biotic barrier (the species exclude one another. Therefore, in addition to environmental characteristics, physical and biotic barriers potentially shaped the limits of the muriqui historical range. Based on these considerations, we proposed the adjustment of their historical distributional limits. Currently only 7.6% of the predicted historical distribution of B. hypoxanthus and 12.9% of B. arachnoides remains forested and able to sustain viable muriqui populations. In addition to measurement of habitat loss we also identified areas for conservation concern where new muriqui populations might be found.

Hospital distribution in a metropolitan city: assessment by a geographical information system grid modelling approach

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Kwang-Soo Lee

2014-05-01

Full Text Available Grid models were used to assess urban hospital distribution in Seoul, the capital of South Korea. A geographical information system (GIS based analytical model was developed and applied to assess the situation in a metropolitan area with a population exceeding 10 million. Secondary data for this analysis were obtained from multiple sources: the Korean Statistical Information Service, the Korean Hospital Association and the Statistical Geographical Information System. A grid of cells measuring 1 × 1 km was superimposed on the city map and a set of variables related to population, economy, mobility and housing were identified and measured for each cell. Socio-demographic variables were included to reflect the characteristics of each area. Analytical models were then developed using GIS software with the number of hospitals as the dependent variable. Applying multiple linear regression and geographically weighted regression models, three factors (highway and major arterial road areas; number of subway entrances; and row house areas were statistically significant in explaining the variance of hospital distribution for each cell. The overall results show that GIS is a useful tool for analysing and understanding location strategies. This approach appears a useful source of information for decision-makers concerned with the distribution of hospitals and other health care centres in a city.

[Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

Science.gov (United States)

Zhang, Qian; Zhong, Jin-Xin

2013-05-01

Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i. e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

Human migration, railways and the geographic distribution of leprosy in Rio Grande do Norte State – Brazil

Science.gov (United States)

Nobre, Mauricio Lisboa; Dupnik, Kathryn Margaret; Nobre, Paulo José Lisboa; De Souza, Márcia Célia Freitas; Dűppre, Nádia Cristina; Sarno, Euzenir Nunes; Jerŏnimo, Selma Maria Bezerra

2016-01-01

Summary Introduction Leprosy is a public health problem in Brazil where 31,044 new cases were detected in 2013. Rio Grande do Norte is a small Brazilian state with a rate of leprosy lower than other areas in the same region, for unknown reasons. Objectives We present here a review based on the analysis of a database of registered leprosy cases in Rio Grande do Norte state, comparing leprosy's geographic distribution among municipalities with local socio-economic and public health indicators and with historical documents about human migration in this Brazilian region. Results The current distribution of leprosy in Rio Grande do Norte did not show correlation with socio-economic or public health indicators at the municipal level, but it appears related to economically emerging municipalities 100 years ago, with spread facilitated by railroads and train stations. Drought-related migratory movements which occurred from this state to leprosy endemic areas within the same period may be involved in the introduction of leprosy and with its present distribution within Rio Grande do Norte. Conclusions Leprosy may disseminate slowly, over many decades in certain circumstances, such as in small cities with few cases. This is a very unusual situation currently and a unique opportunity for epidemiologic studies of leprosy as an emerging disease. PMID:26964429

A revised geographical range for Liolaemus elongates Koslowsky, 1896 (Squamata: Liolaemini in Argentina: review of reported and new-data based distribution with new localities

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Ignacio Minoli

2013-12-01

Full Text Available Estimating the effective geographical ranges of species is central to species-oriented conservation and management. In this paper, we review the geographical distribution of Liolaemus elongatus Koslowsky, 1896 with three new records for northern Chubut and southern Río Negro provinces, Argentina. Based on detailed locality records pooled from multiple data sources, including new records obtained for this study, we revise the range of L. elongatus sensu stricto and provide geographical distribution maps comparing the previously recognized range to that proposed herein. Our results show that L. elongatus possesses a much more limited geographic distribution than previously thought, being restricted to areas south of 38°S latitude; the newly proposed range is merely half the species formerly recognized geographical distribution.

Geographic Distribution of Teaching Talent in California. Consultant's Report Prepared for the State Committee on Public Education.

Science.gov (United States)

Guthrie, James; And Others

The central purpose of this study was to examine the relationship between distribution of teaching talent and geographic location of local school districts of California. School districts were assigned to one of four geographic categories (urban, suburban, rural, or small urban centers). Each category's teaching talent was assessed on six measures…

Implications of China's future bride shortage for the geographical distribution and social protection needs of never-married men.

Science.gov (United States)

Sharygin, Ethan; Ebenstein, Avraham; Das Gupta, Monica

2013-01-01

Because sex ratios at birth have risen sharply in China in recent decades, an increasing proportion of men will be unable to find a bride, and will face old age without the support of a wife and children. We project the proportions of never-married men and their geographical distribution in China in the coming decades. Our projections assume that two tendencies in current marriage patterns will persist: that women will continue to migrate to wealthier areas and to prefer men with better prospects. We find that, by 2030, more than 20 per cent of men in China aged 30-39 will never have married, and that the proportion will be especially high among poor men in low-income provinces that are least able to provide social protection programmes. The projected geographic concentration of bachelors could be socially disruptive, and the results suggest a need to expand the coverage and central financing of social protection programmes.

Factors Influence on Geographic Distribution of Physicians in Selected Countries: A Review Article

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Amir Ashkan Nasiripour

2013-12-01

Full Text Available Background: One of the most important inequalities of providing health services is misdistribution of human resources, especially physicians. Many factors contribute to the distribution of physicians in different regions. The present study was aimed to explore the effective factors in distributing physicians in different countries. Methods: This study is a systematic review, in which the data were gathered through literature review, online searches in multiple databases and relevant organizations’ websites. Later, the collected data were classified using content analysis method, and consequently, they were illustrated in comparative matrix. Results: The factors that influence the dispersion of the physicians are divided into 4 main groups. Firstly, Geographic and Demographic factors of the region such as, population, age, gender and climate. Secondly, Health factors of the region and the country such as, the number of hospitals, health centers and health indicators. Thirdly, Economic, Social and Political factors of the region such as, economic growth, culture and believes. And finally, the factors related to physicians' characteristics and motivation such as, age, gender and the compensation system. Conclusion: There are different reasons why physicians spread in different countries’ geographical regions. Regarding the unequal distribution of physicians in Iran, identifying these influential reasons and also the factors affecting the distribution of physicians, and the impact of each one of these, can lead to a fair and equal distribution of resources of the health sector.

Potential impacts of climatic change upon geographical distributions of birds

DEFF Research Database (Denmark)

Huntley, Brian; Collingham, Yvonne C.; Green, Rhys E.

2006-01-01

likely to decrease. Species with restricted distributions and specialized species of particular biomes are likely to suffer the greatest impacts. Migrant species are likely to suffer especially large impacts as climatic change alters both their breeding and wintering areas, as well as critical stopover......Potential climatic changes of the near future have important characteristics that differentiate them from the largest magnitude and most rapid of climatic changes of the Quaternary. These potential climatic changes are thus a cause for considerable concern in terms of their possible impacts upon...... biodiversity. Birds, in common with other terrestrial organisms, are expected to exhibit one of two general responses to climatic change: they may adapt to the changed conditions without shifting location, or they may show a spatial response, adjusting their geographical distribution in response...

Ecophysiological Traits of Leaves of Three Marsilea Species Distributed in Different Geographical Regions

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Tai-Chung Wu

2011-11-01

Full Text Available Marsilea, an amphibian fern genus (containing ca. 80 species characterized by their unusual leaves and reproductive structures, is distributed over the five continents. To investigate the adaptation traits of three Marsilea species (M. crenata, M. quadrifolia, and M. schelpiana, distributed in different geographic regions, to terrestrial conditions, we compared morphological features, optical properties and photosynthetic performance of leaflets of the three species grown in terrestrial environment. The results showed that leaflets of the three species had significant differences in some of the ecophysiogical traits. Among the three species, M. quadrifolia (distributed in temperate region where receiving low precipitation had the highest trichome density on its leaflet surface and the highest water use efficiency, M. schelpiana (mainly in southern Africa where accepting high level of solar irradiance had the tallest petiole and the highest leaf dissection index, total stomatal pore area index, PSII electron transport rate and photosaturated photosynthetic rate, M. crenata (mainly in southeastern Asia region where receiving high precipitation and with high humidity had the lowest leaf dissection index and water use efficiency. Accordingly, leaf characteristics of the three Marsilea species reflect the climate pattern of their habitats. The results also suggest that water availability and light intensity are two of the important factors contributing to the geographic distribution of the three species.

Comparison of the geographical distribution of feline immunodeficiency virus and feline leukemia virus infections in the United States of America (2000-2011).

Science.gov (United States)

Chhetri, Bimal K; Berke, Olaf; Pearl, David L; Bienzle, Dorothee

2013-01-05

Although feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) have similar risk factors and control measures, infection rates have been speculated to vary in geographic distribution over North America. Since both infections are endemic in North America, it was assumed as a working hypothesis that their geographic distributions were similar. Hence, the purpose of this exploratory analysis was to investigate the comparative geographical distribution of both viral infections. Counts of FIV (n=17,108) and FeLV (n=30,017) positive serology results (FIV antibody and FeLV ELISA) were obtained for 48 contiguous states and District of Columbia of the United States of America (US) from the IDEXX Laboratories website. The proportional morbidity ratio of FIV to FeLV infection was estimated for each administrative region and its geographic distribution pattern was visualized by a choropleth map. Statistical evidence of an excess in the proportional morbidity ratio from unity was assessed using the spatial scan test under the normal probability model. This study revealed distinct spatial distribution patterns in the proportional morbidity ratio suggesting the presence of one or more relevant and geographically varying risk factors. The disease map indicates that there is a higher prevalence of FIV infections in the southern and eastern US compared to FeLV. In contrast, FeLV infections were observed to be more frequent in the western US compared to FIV. The respective excess in proportional morbidity ratio was significant with respect to the spatial scan test (p < 0.05). The observed variability in the geographical distribution of the proportional morbidity ratio of FIV to FeLV may be related to the presence of an additional or unique, but yet unknown, spatial risk factor. Putative factors may be geographic variations in specific virus strains and rate of vaccination. Knowledge of these factors and the geographical distributions of these infections can inform

Differentiation between diploid and tetraploid Centaurea phrygia: mating barriers, morphology and geographic distribution

Czech Academy of Sciences Publication Activity Database

Koutecký, P.; Štěpánek, Jan; Baďurová, T.

2012-01-01

Roč. 84, č. 1 (2012), s. 1-32 ISSN 0032-7786 R&D Projects: GA ČR GA206/09/1126 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : geographic distribution * polyploidy * reproductive isolation Subject RIV: EF - Botanics Impact factor: 2.833, year: 2012

Geographic distribution and conservation status of Caiman latirostris (Crocodylia, Alligatoridae in Uruguay

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Claudio Borteiro

2006-12-01

Full Text Available Populations of Caiman latirostris are known to occur in Uruguay but their geographic distribution remains uncertain. This work presents anupdate of the species distribution and conservation status in Uruguay. Surveys conducted by the authors confirmed the presence of this species in the previously known distribution range of northwestern Uruguay, where it seems to be widespread and relatively abundant in contrast to earlier reports. We report new localities for C. latirostris, most relevant being those of the Cebollatí and Tacuarí Rivers, and the Pelotas, India Muerta and San Miguel stream basins, which significantly expand its distribution through important wetlands in the eastern part of the country. The overall distribution is coincident with different landscape types, where lagoons, artificial impoundments, livestock waterholes, rivers, streams, creeks and marshes are inhabited by caiman. Illegal non-commercial hunting was detected all over the country.

Temporal changes in the geographic distribution, elevation, and potential origin of the Martian outflow channels

Science.gov (United States)

Tribe, S.; Clifford, S. M.

1993-01-01

Observational evidence of outflow channel activity on Mars suggests that water was abundant in the planet's early crust. However, with the decline in the planet's internal heat flow, a freezing front developed within the regolith that propagated downward with time and acted as a thermodynamic sink for crustal H2O. One result of this thermal evolution is that, if the initial inventory of water on Mars was small, the cryosphere may have grown to the point where all the available water was taken up as ground ice. Alternatively, if the inventory of H2O exceeds the current pore volume of the cryosphere, then Mars has always possessed extensive bodies of subpermafrost groundwater. We have investigated the relative age, geographic distribution, elevation, and geologic setting of the outflow channels in an effort to accomplish the following: (1) identify possible modes of origin and evolutionary trends in their formation; (2) gain evidence regarding the duration and spatial distribution of groundwater in the crust; and (3) better constraint estimates of the planetary inventory of H2O.

Geographic distribution of Staphylococcus aureus causing invasive infections in Europe : A molecular-epidemiological analysis

NARCIS (Netherlands)

Grundmann, Hajo; Aanensen, David M; van den Wijngaard, Cees C; Spratt, Brian G; Harmsen, Dag; Friedrich, Alexander W; Tami, Adriana

Background: Staphylococcus aureus is one of the most important human pathogens and methicillin-resistant variants (MRSAs) are a major cause of hospital and community-acquired infection. We aimed to map the geographic distribution of the dominant clones that cause invasive infections in Europe.

Effective environmental factors on geographical distribution of traffic accidents on pedestrians, downtown Tehran city.

Science.gov (United States)

Moradi, Ali; Soori, Hamid; Kavousi, Amir; Eshghabadi, Farshid; Nematollahi, Shahrzad; Zeini, Salahdien

2017-01-01

In most countries, occurrence of traffic causalities is high in pedestrians. The aim of this study is to geographically analyze the traffic casualties in pedestrians in downtown Tehran city. The study population consisted of traffic injury accidents in pedestrians occurred during 2015 in Tehran city. Data were extracted from offices of traffic police and municipality. For analysis of environmental factors and site of accidents, ordinary least square regression models and geographically weighted regression were used. Fitness and performance of models were checked using the Akaike information criteria, Bayesian information criteria, deviance, and adjusted R 2 . Totally, 514 accidents were included in this study. Of them, site of accidents was arterial streets in 370 (71.9%) cases, collector streets in 133 cases (25.2%), and highways in 11 cases (2.1%). Geographical units of traffic accidents in pedestrians had statistically significant relationship with a number of bus stations, number of crossroads, and recreational areas. Distribution of injury traffic accidents in pedestrians is different in downtown Tehran city. Neighborhoods close to markets are considered as most dangerous neighborhoods for injury traffic accidents. Different environmental factors are involved in determining the distribution of these accidents. The health of pedestrians in Tehran city can be improved by proper traffic management, control of environmental factors, and educational programs.

Towards a theoretical determination of the geographical probability distribution of meteoroid impacts on Earth

Science.gov (United States)

Zuluaga, Jorge I.; Sucerquia, Mario

2018-06-01

Tunguska and Chelyabinsk impact events occurred inside a geographical area of only 3.4 per cent of the Earth's surface. Although two events hardly constitute a statistically significant demonstration of a geographical pattern of impacts, their spatial coincidence is at least tantalizing. To understand if this concurrence reflects an underlying geographical and/or temporal pattern, we must aim at predicting the spatio-temporal distribution of meteoroid impacts on Earth. For this purpose we designed, implemented, and tested a novel numerical technique, the `Gravitational Ray Tracing' (GRT) designed to compute the relative impact probability (RIP) on the surface of any planet. GRT is inspired by the so-called ray-casting techniques used to render realistic images of complex 3D scenes. In this paper we describe the method and the results of testing it at the time of large impact events. Our findings suggest a non-trivial pattern of impact probabilities at any given time on the Earth. Locations at 60-90° from the apex are more prone to impacts, especially at midnight. Counterintuitively, sites close to apex direction have the lowest RIP, while in the antapex RIP are slightly larger than average. We present here preliminary maps of RIP at the time of Tunguska and Chelyabinsk events and found no evidence of a spatial or temporal pattern, suggesting that their coincidence was fortuitous. We apply the GRT method to compute theoretical RIP at the location and time of 394 large fireballs. Although the predicted spatio-temporal impact distribution matches marginally the observed events, we successfully predict their impact speed distribution.

Current distribution in conducting nanowire networks

Science.gov (United States)

Kumar, Ankush; Vidhyadhiraja, N. S.; Kulkarni, Giridhar U.

2017-07-01

Conducting nanowire networks find diverse applications in solar cells, touch-screens, transparent heaters, sensors, and various related transparent conducting electrode (TCE) devices. The performances of these devices depend on effective resistance, transmittance, and local current distribution in these networks. Although, there have been rigorous studies addressing resistance and transmittance in TCE, not much attention is paid on studying the distribution of current. Present work addresses this compelling issue of understanding current distribution in TCE networks using analytical as well as Monte-Carlo approaches. We quantified the current carrying backbone region against isolated and dangling regions as a function of wire density (ranging from percolation threshold to many multiples of threshold) and compared the wired connectivity with those obtained from template-based methods. Further, the current distribution in the obtained backbone is studied using Kirchhoff's law, which reveals that a significant fraction of the backbone (which is believed to be an active current component) may not be active for end-to-end current transport due to the formation of intervening circular loops. The study shows that conducting wire based networks possess hot spots (extremely high current carrying regions) which can be potential sources of failure. The fraction of these hot spots is found to decrease with increase in wire density, while they are completely absent in template based networks. Thus, the present work discusses unexplored issues related to current distribution in conducting networks, which are necessary to choose the optimum network for best TCE applications.

Comparison of the geographical distribution of feline immunodeficiency virus and feline leukemia virus infections in the United States of America (2000–2011

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Chhetri Bimal K

2013-01-01

Full Text Available Abstract Background Although feline immunodeficiency virus (FIV and feline leukemia virus (FeLV have similar risk factors and control measures, infection rates have been speculated to vary in geographic distribution over North America. Since both infections are endemic in North America, it was assumed as a working hypothesis that their geographic distributions were similar. Hence, the purpose of this exploratory analysis was to investigate the comparative geographical distribution of both viral infections. Counts of FIV (n=17,108 and FeLV (n=30,017 positive serology results (FIV antibody and FeLV ELISA were obtained for 48 contiguous states and District of Columbia of the United States of America (US from the IDEXX Laboratories website. The proportional morbidity ratio of FIV to FeLV infection was estimated for each administrative region and its geographic distribution pattern was visualized by a choropleth map. Statistical evidence of an excess in the proportional morbidity ratio from unity was assessed using the spatial scan test under the normal probability model. Results This study revealed distinct spatial distribution patterns in the proportional morbidity ratio suggesting the presence of one or more relevant and geographically varying risk factors. The disease map indicates that there is a higher prevalence of FIV infections in the southern and eastern US compared to FeLV. In contrast, FeLV infections were observed to be more frequent in the western US compared to FIV. The respective excess in proportional morbidity ratio was significant with respect to the spatial scan test (p Conclusions The observed variability in the geographical distribution of the proportional morbidity ratio of FIV to FeLV may be related to the presence of an additional or unique, but yet unknown, spatial risk factor. Putative factors may be geographic variations in specific virus strains and rate of vaccination. Knowledge of these factors and the geographical

Using Metadata to Build Geographic Information Sharing Environment on Internet

Directory of Open Access Journals (Sweden)

Chih-hong Sun

1999-12-01

Full Text Available Internet provides a convenient environment to share geographic information. Web GIS (Geographic Information System even provides users a direct access environment to geographic databases through Internet. However, the complexity of geographic data makes it difficult for users to understand the real content and the limitation of geographic information. In some cases, users may misuse the geographic data and make wrong decisions. Meanwhile, geographic data are distributed across various government agencies, academic institutes, and private organizations, which make it even more difficult for users to fully understand the content of these complex data. To overcome these difficulties, this research uses metadata as a guiding mechanism for users to fully understand the content and the limitation of geographic data. We introduce three metadata standards commonly used for geographic data and metadata authoring tools available in the US. We also review the current development of geographic metadata standard in Taiwan. Two metadata authoring tools are developed in this research, which will enable users to build their own geographic metadata easily.[Article content in Chinese

Location of radiotherapy centers: An exploratory geographic analysis for Belgium

International Nuclear Information System (INIS)

Cotteels, C.; Peeters, D.; Coucke, P.A.; Thomas, I.

2012-01-01

Purpose. - The distance between the patient's home and a radiotherapy department may represent a hurdle for the patient and influence treatment choice. Therefore, it is necessary to check whether the geographical distribution of radiotherapy centers is in accordance with cancer incidence, taking also into account the cost of travelling to the radiotherapy department. The objective of this study is double; first, to map the current locations of radiotherapy centers across the country and second, to evaluate the observed spatial disparities with appropriate tools. Materials and methods. - A model of operational research (P-median) is used to suggest the optimal locations and allocations and to compare them with the current situation. This is an exploratory study with simple inputs. It helps to better understand the current geographical distribution of radiotherapy centers in Belgium as well as its possible limitations. Results-conclusion. - It appears that the current situation is on the average acceptable in terms of accessibility to the service and that the method presents huge potentialities for decision making so as to yield a spatial system that is both efficient and equitable. (authors)

The evolution of cooperation on geographical networks

Science.gov (United States)

Li, Yixiao; Wang, Yi; Sheng, Jichuan

2017-11-01

We study evolutionary public goods game on geographical networks, i.e., complex networks which are located on a geographical plane. The geographical feature effects in two ways: In one way, the geographically-induced network structure influences the overall evolutionary dynamics, and, in the other way, the geographical length of an edge influences the cost when the two players at the two ends interact. For the latter effect, we design a new cost function of cooperators, which simply assumes that the longer the distance between two players, the higher cost the cooperator(s) of them have to pay. In this study, network substrates are generated by a previous spatial network model with a cost-benefit parameter controlling the network topology. Our simulations show that the greatest promotion of cooperation is achieved in the intermediate regime of the parameter, in which empirical estimates of various railway networks fall. Further, we investigate how the distribution of edges' geographical costs influences the evolutionary dynamics and consider three patterns of the distribution: an approximately-equal distribution, a diverse distribution, and a polarized distribution. For normal geographical networks which are generated using intermediate values of the cost-benefit parameter, a diverse distribution hinders the evolution of cooperation, whereas a polarized distribution lowers the threshold value of the amplification factor for cooperation in public goods game. These results are helpful for understanding the evolution of cooperation on real-world geographical networks.

Geographic distribution of phlebotomine sandfly species (Diptera: Psychodidae) in Central-West Brazil

Science.gov (United States)

de Almeida, Paulo Silva; de Andrade, Andrey José; Sciamarelli, Alan; Raizer, Josué; Menegatti, Jaqueline Aparecida; Hermes, Sandra Cristina Negreli Moreira; de Carvalho, Maria do Socorro Laurentino; Gurgel-Gonçalves, Rodrigo

2015-01-01

This study updates the geographic distributions of phlebotomine species in Central-West Brazil and analyses the climatic factors associated with their occurrence. The data were obtained from the entomology services of the state departments of health in Central-West Brazil, scientific collections and a literature review of articles from 1962-2014. Ecological niche models were produced for sandfly species with more than 20 occurrences using the Maxent algorithm and eight climate variables. In all, 2,803 phlebotomine records for 127 species were analysed. Nyssomyia whitmani, Evandromyia lenti and Lutzomyia longipalpis were the species with the greatest number of records and were present in all the biomes in Central-West Brazil. The models, which were produced for 34 species, indicated that the Cerrado areas in the central and western regions of Central-West Brazil were climatically more suitable to sandflies. The variables with the greatest influence on the models were the temperature in the coldest months and the temperature seasonality. The results show that phlebotomine species in Central-West Brazil have different geographical distribution patterns and that climate conditions in essentially the entire region favour the occurrence of at least one Leishmania vector species, highlighting the need to maintain or intensify vector control and surveillance strategies. PMID:26018450

Behavioral and physiological correlates of the geographic distributions of amphibious sea kraits (Laticauda spp.)

Science.gov (United States)

Brischoux, François; Tingley, Reid; Shine, Richard; Lillywhite, Harvey B.

2013-02-01

The physiological costs of living in seawater likely influenced the secondary evolutionary transitions to marine life in tetrapods. However, these costs are alleviated for species that commute between the land and the sea, because terrestrial habitats can provide frequent access to fresh water. Here, we investigate how differences in the ecology and physiology of three sea krait species (Laticauda spp.) interact to determine their environmental tolerances and geographic distributions. These three species vary in their relative use of terrestrial versus marine environments, and they display concomitant adaptations to life on land versus at sea. A species with relatively high dehydration rates in seawater (Laticauda colubrina) occupied oceanic areas with low mean salinities, whereas a species with comparatively high rates of transcutaneous evaporative water loss on land (Laticauda semifasciata) occupied regions with low mean temperatures. A third taxon (Laticauda laticaudata) was intermediate in both of these traits, and yet occupied the broadest geographic range. Our results suggest that the abilities of sea kraits to acquire fresh water on land and tolerate dehydration at sea determine their environmental tolerances and geographic distributions. This finding supports the notion that speciation patterns within sea kraits have been driven by interspecific variation in the degree of reliance upon terrestrial versus marine habitats. Future studies could usefully examine the effects of osmotic challenges on diversification rates in other secondarily marine tetrapod species.

Geographic distribution of canine heartworm (Dirofilaria immitis infection in stray dogs of eastern Romania

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Lavinia Ciucă

2016-11-01

Full Text Available A survey was conducted in the eastern part of Romania to assess the prevalence and geographical distribution of Dirofilaria immitis in dogs. Plasma samples were collected from 458 stray dogs hosted in shelters in 8 counties and tested serologically for the presence of heartworm. In addition, 45 blood samples from dogs of a shelter in Galati city were examined by the modified Knott and multiplex polymerase chain reaction (PCR techniques. The immmunological assay showed a heartworm infection prevalence of 8.9% in the dogs. Optical density results for positive samples ranged between 0.217 and 2.683. Geographical information systems (GIS were used to produce overlays of distribution maps of D. immitis prevalence and predictive maps based on temperature suitability. High prevalence of D. immitis was found in the central East up to the northern border of the country, i.e. Galati county (60%, followed by the counties of Vaslui (12.0% and Iasi (7.7%. Out of 45 samples examined using the Knott test, 23 were positive for circulating microfilariae (51.1%, while 19 dogs were positive for D. immitis and 4 for both D. immitis and D. repens with the multiplex PCR test. The high prevalence for D. immitis shown in dogs in the Southeast (Galati, 42.2% also by multiplex PCR gave strong support to the results achieved by the serological tests. The present study confirms the ability of GIS to predict the distribution and epidemiology of dirofilariosis in different geographical territories as has been already demonstrated by the empirical epidemiological data obtained at the continental, national and intraregional levels.

Current Distribution Characteristics of CFRP Panels

Science.gov (United States)

Yamamoto, Kazuo

CFRP (Carbon Fiber Reinforced Plastic) is widely used in the structures of aircrafts, automobiles, wing turbines, and rockets because of its qualities of high mechanical strength, low weight, fatigue resistance, and dimensional stability. However, these structures are often at risk of being struck by lightning. When lightning strikes such structures and lightning current flows through the CFRP, it may be structurally damaged because of the impact of the lightning strike or ignitions between layers. If there are electronic systems near the CFRP, they may break down or malfunction because of the resulting electromagnetic disturbance. In fact, the generation mechanisms of these breakdowns and malfunctions depend on the current distribution in the CFRP. Hence, it is critical to clarify the current distribution in various kinds of CFRPs. In this study, two kinds of CFRP panels—one composed of quasi-isotropic lamination layers and the other composed of 0°/90° lamination layers of unidirectional CFRP prepregs—are used to investigate the dependence of current distribution on the nature of the lamination layers. The current distribution measurements and simulations for CFRP panels are compared with those for a same-sized aluminum plate. The knowledge of these current distribution characteristics would be very useful for designing the CFRP structures of aircrafts, automobiles, wing turbines, rockets, etc. in the future.

History Shaped the Geographic Distribution of Genomic Admixture on the Island of Puerto Rico

Science.gov (United States)

Via, Marc; Gignoux, Christopher R.; Roth, Lindsey A.; Fejerman, Laura; Galanter, Joshua; Choudhry, Shweta; Toro-Labrador, Gladys; Viera-Vera, Jorge; Oleksyk, Taras K.; Beckman, Kenneth; Ziv, Elad; Risch, Neil

2011-01-01

Contemporary genetic variation among Latin Americans human groups reflects population migrations shaped by complex historical, social and economic factors. Consequently, admixture patterns may vary by geographic regions ranging from countries to neighborhoods. We examined the geographic variation of admixture across the island of Puerto Rico and the degree to which it could be explained by historic and social events. We analyzed a census-based sample of 642 Puerto Rican individuals that were genotyped for 93 ancestry informative markers (AIMs) to estimate African, European and Native American ancestry. Socioeconomic status (SES) data and geographic location were obtained for each individual. There was significant geographic variation of ancestry across the island. In particular, African ancestry demonstrated a decreasing East to West gradient that was partially explained by historical factors linked to the colonial sugar plantation system. SES also demonstrated a parallel decreasing cline from East to West. However, at a local level, SES and African ancestry were negatively correlated. European ancestry was strongly negatively correlated with African ancestry and therefore showed patterns complementary to African ancestry. By contrast, Native American ancestry showed little variation across the island and across individuals and appears to have played little social role historically. The observed geographic distributions of SES and genetic variation relate to historical social events and mating patterns, and have substantial implications for the design of studies in the recently admixed Puerto Rican population. More generally, our results demonstrate the importance of incorporating social and geographic data with genetics when studying contemporary admixed populations. PMID:21304981

Virtual Geographic Simulation of Light Distribution within Three-Dimensional Plant Canopy Models

Directory of Open Access Journals (Sweden)

Liyu Tang

2017-12-01

Full Text Available Virtual geographic environments (VGEs have been regarded as an important new means of simulating, analyzing, and understanding complex geological processes. Plants and light are major components of the geographic environment. Light is a critical factor that affects ecological systems. In this study, we focused on simulating light transmission and distribution within a three-dimensional plant canopy model. A progressive refinement radiosity algorithm was applied to simulate the transmission and distribution of solar light within a detailed, three-dimensional (3D loquat (Eriobotrya japonica Lindl. canopy model. The canopy was described in three dimensions, and each organ surface was represented by a set of triangular facets. The form factors in radiosity were calculated using a hemi-cube algorithm. We developed a module for simulating the instantaneous light distribution within a virtual canopy, which was integrated into ParaTree. We simulated the distribution of photosynthetically active radiation (PAR within a loquat canopy, and calculated the total PAR intercepted at the whole canopy scale, as well as the mean PAR interception per unit leaf area. The ParaTree-integrated radiosity model simulates the uncollided propagation of direct solar and diffuse sky light and the light-scattering effect of foliage. The PAR captured by the whole canopy based on the radiosity is approximately 9.4% greater than that obtained using ray tracing and TURTLE methods. The latter methods do not account for the scattering among leaves in the canopy in the study, and therefore, the difference might be due to the contribution of light scattering in the foliage. The simulation result is close to Myneni’s findings, in which the light scattering within a canopy is less than 10% of the incident PAR. Our method can be employed for visualizing and analyzing the spatial distribution of light within a canopy, and for estimating the PAR interception at the organ and canopy

Geographic distribution of trauma centers and injury-related mortality in the United States.

Science.gov (United States)

Brown, Joshua B; Rosengart, Matthew R; Billiar, Timothy R; Peitzman, Andrew B; Sperry, Jason L

2016-01-01

Regionalized trauma care improves outcomes; however, access to care is not uniform across the United States. The objective was to evaluate whether geographic distribution of trauma centers correlates with injury mortality across state trauma systems. Level I or II trauma centers in the contiguous United States were mapped. State-level age-adjusted injury fatality rates per 100,000 people were obtained and evaluated for spatial autocorrelation. Nearest neighbor ratios (NNRs) were generated for each state. A NNR less than 1 indicates clustering, while a NNR greater than 1 indicates dispersion. NNRs were tested for difference from random geographic distribution. Fatality rates and NNRs were examined for correlation. Fatality rates were compared between states with trauma center clustering versus dispersion. Trauma center distribution and population density were evaluated. Spatial-lag regression determined the association between fatality rate and NNR, controlling for state-level demographics, population density, injury severity, trauma system resources, and socioeconomic factors. Fatality rates were spatially autocorrelated (Moran's I = 0.35, p center distribution. Fatality rate and NNR were correlated (ρ = 0.34, p = 0.03). Clustered states had a lower median injury fatality rate compared with dispersed states (56.9 [IQR, 46.5-58.9] vs. 64.9 [IQR, 52.5-77.1]; p = 0.04). Dispersed compared with clustered states had more counties without a trauma center that had higher population density than counties with a trauma center (5.7% vs. 1.2%, p distribution of trauma centers correlates with injury mortality, with more clustered state trauma centers associated with lower fatality rates. This may be a result of access relative to population density. These results may have implications for trauma system planning and require further study to investigate underlying mechanisms. Therapeutic/care management study, level IV.

Effect of Heterogeneity in Initial Geographic Distribution on Opinions’ Competitiveness

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Alexander S. Balankin

2015-05-01

Full Text Available Spin dynamics on networks allows us to understand how a global consensus emerges out of individual opinions. Here, we are interested in the effect of heterogeneity in the initial geographic distribution of a competing opinion on the competitiveness of its own opinion. Accordingly, in this work, we studied the effect of spatial heterogeneity on the majority rule dynamics using a three-state spin model, in which one state is neutral. Monte Carlo simulations were performed on square lattices divided into square blocks (cells. Accordingly, one competing opinion was distributed uniformly among cells, whereas the spatial distribution of the rival opinion was varied from the uniform to heterogeneous, with the median-to-mean ratio in the range from 1 to 0. When the size of discussion group is odd, the uncommitted agents disappear completely after  3.30 ± 0.05 update cycles, and then the system evolves in a two-state regime with complementary spatial distributions of two competing opinions. Even so, the initial heterogeneity in the spatial distribution of one of the competing opinions causes a decrease of this opinion competitiveness. That is, the opinion with initially heterogeneous spatial distribution has less probability to win, than the opinion with the initially uniform spatial distribution, even when the initial concentrations of both opinions are equal. We found that although the time to consensus , the opinion’s recession rate is determined during the first 3.3 update cycles. On the other hand, we found that the initial heterogeneity of the opinion spatial distribution assists the formation of quasi-stable regions, in which this opinion is dominant. The results of Monte Carlo simulations are discussed with regard to the electoral competition of political parties.

Western Gulf of Mexico, June 1993 to June 1994 Average Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_wgom_AVG_MMS_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the western...

Eastern Gulf of Mexico, February 1996 to June 1997 Average Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_AVG_MMS_1997

Data.gov (United States)

Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

Geographic Distribution of Trauma Centers and Injury Related Mortality in the United States

Science.gov (United States)

Brown, Joshua B.; Rosengart, Matthew R.; Billiar, Timothy R.; Peitzman, Andrew B.; Sperry, Jason L.

2015-01-01

Background Regionalized trauma care improves outcomes; however access to care is not uniform across the US. The objective was to evaluate whether geographic distribution of trauma centers correlates with injury mortality across state trauma systems. Methods Level I/II trauma centers in the contiguous US were mapped. State-level age-adjusted injury fatality rates/100,000people were obtained and evaluated for spatial autocorrelation. Nearest neighbor ratios (NNR) were generated for each state. A NNR1 indicates dispersion. NNR were tested for difference from random geographic distribution. Fatality rates and NNR were examined for correlation. Fatality rates were compared between states with trauma center clustering versus dispersion. Trauma center distribution and population density were evaluated. Spatial-lag regression determined the association between fatality rate and NNR, controlling for state-level demographics, population density, injury severity, trauma system resources, and socioeconomic factors. Results Fatality rates were spatially autocorrelated (Moran's I=0.35, pcenter distribution. Fatality rate and NNR were correlated (ρ=0.34, p=0.03). Clustered states had a lower median injury fatality rate compared to dispersed states (56.9 [IQR 46.5–58.9] versus 64.9 [IQR 52.5–77.1], p=0.04). Dispersed compared to clustered states had more counties without a trauma center that had higher population density than counties with a trauma center (5.7% versus 1.2%, pdistribution of trauma centers correlates with injury mortality, with more clustered state trauma centers associated with lower fatality rates. This may be a result of access relative to population density. These results may have implications for trauma system planning and requires further study to investigate underlying mechanisms PMID:26517780

Review of the geographic distribution of Micrurus decoratus (Jan, 1858 (Serpentes: Elapidae

Directory of Open Access Journals (Sweden)

Rodrigo Castellari Gonzalez

2014-08-01

Full Text Available Micrurus decoratus (Jan, 1858 is a poorly known species of coral snake, with a controversial history concerning its geographical range. The lack of consensus among researchers, since its original description, is largely due to the reporting of erroneous localities in publications. Herein we present the geographical range for the species based on the review of 184 records from 67 different municipalities in Brazil, including two new records for the state of Espírito Santo, extending its distribution to ca. 300 km northward from the previous northernmost locality. We also comment on doubtful records for the states of Rio Grande do Sul and Bahia, which contain no accurate data. We restrict the occurrence of Micrurus decoratus to the Atlantic Rainforest, with elevation range from 400 up to 1,600 m in the Brazilian states of Santa Catarina, Paraná, São Paulo, Rio de Janeiro, Minas Gerais and Espírito Santo.

On the geographical distribution of induced time-varying crustal magnetic fields

DEFF Research Database (Denmark)

Thebault, E.; Hemant, K.; Hulot, G.

2009-01-01

A long standing question in geomagnetism is whether the time variation of the induced crustal field is a detectable quantity and, if so, at which spatial wavelengths. We tackle this problem with the help of a forward modeling approach using a vertically integrated susceptibility (VIS) grid...... of the Earth's crust. For spherical harmonic degrees 15-90, we estimate the root mean square of the crustal magnetic field secular variation to amount 0.06-0.12 nT/yr at the terrestrial surface between epochs 1960-2002.5. The geographical distribution of the signal shows absolute values reaching 0.65-1.30 n...

Geographic distribution of suicide and railway suicide in Belgium, 2008-2013: a principal component analysis.

Science.gov (United States)

Strale, Mathieu; Krysinska, Karolina; Overmeiren, Gaëtan Van; Andriessen, Karl

2017-06-01

This study investigated the geographic distribution of suicide and railway suicide in Belgium over 2008--2013 on local (i.e., district or arrondissement) level. There were differences in the regional distribution of suicide and railway suicides in Belgium over the study period. Principal component analysis identified three groups of correlations among population variables and socio-economic indicators, such as population density, unemployment, and age group distribution, on two components that helped explaining the variance of railway suicide at a local (arrondissement) level. This information is of particular importance to prevent suicides in high-risk areas on the Belgian railway network.

Geographical distribution of the red howler monkey (Alouatta seniculus) and yellow fever in Colombia.

Science.gov (United States)

Piedrahita-Cortés, Juan; Soler-Tovar, Diego

2016-02-11

Colombia is a country with an important diversity of non-human primates, of which the red howler monkey (Alouatta seniculus) stands out because of its distribution and the role it plays in the occurrence of yellow fever.  To describe the geographic co-occurrence of Alouatta seniculus and the reported presence of yellow fever.  We conducted a descriptive study. The reported presence of yellow fever in Colombia was obtained from the reports and bulletins issued by the Instituto Nacional de Salud, and the study by Segura, et al. (2013). The occurrence of A. seniculus was determined based on the data from the Global Biodiversity Information Facility and the Colombian Biodiversity Information System. A map of the occurrence was developed using the DIVA-GIS program, and the ecological niche model under current conditions was created with the Maxent program.  The departments with the highest occurrence of A. seniculus were Antioquia, Meta and Casanare; 69.5% of the departments with reported history of yellow fever had co-occurrence with A. seniculus. The ecological niche model showed that Antioquia, Bolívar, La Guajira, Magdalena, Meta, Santander, Norte de Santander and Vichada had geographical portions with a probability rate nearing to 0.9 (90%).  In 69.5% of the departments with a history of yellow fever there was co-occurrence with A. seniculus, which is relevant because non-human primates play a well-known role as natural reservoirs of the virus, and they might contribute to the occurrence of the yellow fever, which makes them very useful as sentinels.

Current distribution characteristics of superconducting parallel circuits

International Nuclear Information System (INIS)

Mori, K.; Suzuki, Y.; Hara, N.; Kitamura, M.; Tominaka, T.

1994-01-01

In order to increase the current carrying capacity of the current path of the superconducting magnet system, the portion of parallel circuits such as insulated multi-strand cables or parallel persistent current switches (PCS) are made. In superconducting parallel circuits of an insulated multi-strand cable or a parallel persistent current switch (PCS), the current distribution during the current sweep, the persistent mode, and the quench process were investigated. In order to measure the current distribution, two methods were used. (1) Each strand was surrounded with a pure iron core with the air gap. In the air gap, a Hall probe was located. The accuracy of this method was deteriorated by the magnetic hysteresis of iron. (2) The Rogowski coil without iron was used for the current measurement of each path in a 4-parallel PCS. As a result, it was shown that the current distribution characteristics of a parallel PCS is very similar to that of an insulated multi-strand cable for the quench process

The geographic distribution of the otolaryngology workforce in the United States.

Science.gov (United States)

Lango, Miriam N; Handorf, Elizabeth; Arjmand, Ellis

2017-01-01

To describe the deployment of otolaryngologists and evaluate factors associated with the geographic distribution of otolaryngologists in the United States. Cross-sectional study. The otolaryngology physician supply was defined as the number of otolaryngologists per 100,000 in the hospital referral region (HRR). The otolaryngology physician supply was derived from the American Medical Association Masterfile or from the Medicare Enrollment and Provider Utilization Files. Multiple linear regression tested the association of population, physician, and hospital factors on the supply of Medicare-enrolled otolaryngologists/HRR. Two methods of measuring the otolaryngology workforce were moderately correlated across hospital referral regions (Pearson coefficient 0.513, P = .0001); regardless, the supply of otolaryngology providers varies greatly over different geographic regions. Otolaryngologists concentrate in regions with many other physicians, particularly specialist physicians. The otolaryngology supply also increases with regional population income and education levels. Using AMA-derived data, there was no association between the supply of otolaryngologists and staffed acute-care hospital beds and the presence of an otolaryngology residency-training program. In contrast, the supply of otolaryngology providers enrolled in Medicare independently increases for each HRR by 0.8 per 100,000 for each unit increase in supply of hospital beds (P otolaryngology residency-training program (P = .006), accounting for all other factors. Irrespective of methodology, the supply of otolaryngologists varies widely across geographic regions in the United States. For Medicare beneficiaries, regional hospital factors-including the presence of an otolaryngology residency program-may improve access to otolaryngology services. NA Laryngoscope, 127:95-101, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Spatial and temporal distribution of ionospheric currents-4: altitude ...

African Journals Online (AJOL)

(a) The continuous distribution of current density model reproduces the altitude distribution parameters of EEJ current density very well, (b) the altitude distribution parameters of EEJ current density in India and Peru are not significantly different and (c) The altitude distribution parameters of EEJ current density from rockets ...

Spatial distribution and influence factors of interprovincial terrestrial physical geographical names in China

Science.gov (United States)

Zhang, S.; Wang, Y.; Ju, H.

2017-12-01

The interprovincial terrestrial physical geographical entities are the key areas of regional integrated management. Based on toponomy dictionaries and different thematic maps, the attributes and the spatial extent of the interprovincial terrestrial physical geographical names (ITPGN, including terrain ITPGN and water ITPGN) were extracted. The coefficient of variation and Moran's I were combined together to measure the spatial variation and spatial association of ITPGN. The influencing factors of the distribution of ITPGN and the implications for the regional management were further discussed. The results showed that 11325 ITPGN were extracted, including 7082 terrain ITPGN and 4243 water ITPGN. Hunan Province had the largest number of ITPGN in China, and Shanghai had the smallest number. The spatial variance of the terrain ITPGN was larger than that of the water ITPGN, and the ITPGN showed a significant agglomeration phenomenon in the southern part of China. Further analysis showed that the number of ITPGN was positively related with the relative elevation and the population where the relative elevation was lower than 2000m and the population was less than 50 million. But the number of ITPGN showed a negative relationship with the two factors when their values became larger, indicating a large number of unnamed entities existed in complex terrain areas and a decreasing number of terrestrial physical geographical entities in densely populated area. Based on these analysis, we suggest the government take the ITPGN as management units to realize a balance development between different parts of the entities and strengthen the geographical names census and the nomination of unnamed interprovincial physical geographical entities. This study also demonstrated that the methods of literature survey, coefficient of variation and Moran's I can be combined to enhance the understanding of the spatial pattern of ITPGN.

Geographic Region, Size, and Program Type in Family Practice Residencies.

Science.gov (United States)

Berg, Jolene K.; Garrard, Judith

1981-01-01

Research on residency education in family practice is discussed. Programmatic variables are examined: geographic region, size, and type of program. Definitions of these variables are provided, the current distribution of family practice residency programs across each of these variables is described, and data for use by other researchers is…

Geographic distribution of ebony leaf monkey Trachypithecus auratus (E. Geoffroy Saint-Hilaire, 1812) (Mammalia: Primates: Cercopithecidae)

NARCIS (Netherlands)

Nijman, Vincent

2000-01-01

As one of the fundamental units of ecology and biogeography, the geographic distribution of the endemic and threatened ebony leaf monkey Trachypithecus auratus (E. Geoffroy Saint-Hilaire, 1812) on the islands of Java, Bali, and Lombok (Indonesia) has been assessed. All localities where the species

Geographically distributed hybrid testing & collaboration between geotechnical centrifuge and structures laboratories

Science.gov (United States)

Ojaghi, Mobin; Martínez, Ignacio Lamata; Dietz, Matt S.; Williams, Martin S.; Blakeborough, Anthony; Crewe, Adam J.; Taylor, Colin A.; Madabhushi, S. P. Gopal; Haigh, Stuart K.

2018-01-01

Distributed Hybrid Testing (DHT) is an experimental technique designed to capitalise on advances in modern networking infrastructure to overcome traditional laboratory capacity limitations. By coupling the heterogeneous test apparatus and computational resources of geographically distributed laboratories, DHT provides the means to take on complex, multi-disciplinary challenges with new forms of communication and collaboration. To introduce the opportunity and practicability afforded by DHT, here an exemplar multi-site test is addressed in which a dedicated fibre network and suite of custom software is used to connect the geotechnical centrifuge at the University of Cambridge with a variety of structural dynamics loading apparatus at the University of Oxford and the University of Bristol. While centrifuge time-scaling prevents real-time rates of loading in this test, such experiments may be used to gain valuable insights into physical phenomena, test procedure and accuracy. These and other related experiments have led to the development of the real-time DHT technique and the creation of a flexible framework that aims to facilitate future distributed tests within the UK and beyond. As a further example, a real-time DHT experiment between structural labs using this framework for testing across the Internet is also presented.

The bioclimatic envelope of the wolverine (Gulo gulo): do climatic constraints limit its geographic distribution?

Science.gov (United States)

J. P. Copeland; K. S. McKelvey; K. B. Aubry; A. Landa; J. Persson; R. M. Inman; J. Krebs; E. Lofroth; H. Golden; J. R. Squires; A. Magoun; M. K. Schwartz; J. Wilmot; C. L. Copeland; R. E. Yates; I. Kojola; R. May

2010-01-01

We propose a fundamental geographic distribution for the wolverine (Gulo gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with persistent spring snow cover for successful reproductive denning and by an upper limit of thermoneutrality. To investigate this hypothesis, we developed a composite of MODIS...

Geographic distribution of Staphylococcus aureus causing invasive infections in Europe: a molecular-epidemiological analysis.

Directory of Open Access Journals (Sweden)

Hajo Grundmann

2010-01-01

Full Text Available Staphylococcus aureus is one of the most important human pathogens and methicillin-resistant variants (MRSAs are a major cause of hospital and community-acquired infection. We aimed to map the geographic distribution of the dominant clones that cause invasive infections in Europe.In each country, staphylococcal reference laboratories secured the participation of a sufficient number of hospital laboratories to achieve national geo-demographic representation. Participating laboratories collected successive methicillin-susceptible (MSSA and MRSA isolates from patients with invasive S. aureus infection using an agreed protocol. All isolates were sent to the respective national reference laboratories and characterised by quality-controlled sequence typing of the variable region of the staphylococcal spa gene (spa typing, and data were uploaded to a central database. Relevant genetic and phenotypic information was assembled for interactive interrogation by a purpose-built Web-based mapping application. Between September 2006 and February 2007, 357 laboratories serving 450 hospitals in 26 countries collected 2,890 MSSA and MRSA isolates from patients with invasive S. aureus infection. A wide geographical distribution of spa types was found with some prevalent in all European countries. MSSA were more diverse than MRSA. Genetic diversity of MRSA differed considerably between countries with dominant MRSA spa types forming distinctive geographical clusters. We provide evidence that a network approach consisting of decentralised typing and visualisation of aggregated data using an interactive mapping tool can provide important information on the dynamics of MRSA populations such as early signalling of emerging strains, cross border spread, and importation by travel.In contrast to MSSA, MRSA spa types have a predominantly regional distribution in Europe. This finding is indicative of the selection and spread of a limited number of clones within health care

Temporal trend, geographic distribution, and publication quality in asbestos research.

Science.gov (United States)

Ugolini, Donatella; Bonassi, Stefano; Cristaudo, Alfonso; Leoncini, Giacomo; Ratto, Giovanni Battista; Neri, Monica

2015-05-01

Asbestos is a well-known cause of cancer and respiratory diseases. The aim of the current study was to investigate the scientific production in asbestos research evaluating temporal trend, geographic distribution, impact factor (IF) of published literature, and taking into account socioeconomic variables. The PubMed database was searched starting from 1970. Publication numbers and IF were evaluated as absolute values and after standardization by population and gross domestic product (GDP). Six thousand nine hundred seven articles related to asbestos were retrieved. Publications grew steeply in the 1970s, leveled off in the 1980s, decreased in the 1990s, and then increased again. Mesothelioma, lung neoplasms, and occupational diseases are the most commonly used keywords. In the period of 1988-2011, 4220 citations were retrieved, 3187 of whom had an impact factor. The US, Italy, and the UK were the most productive countries. European countries published about 20 % more asbestos-related articles than the US, although the latter reached a higher mean IF, ranking second after Australia. When the national scientific production (sum of IF) was compared taking into account socioeconomic variables, Australia and Scandinavian countries performed very well, opposite to all main asbestos producers like Russia, China, and Brazil (except for Canada). The American Journal of Industrial Medicine and the Italian La Medicina del Lavoro published the highest numbers of articles. This study provides the first bibliometric analysis of scientific production in asbestos research. Interest appears to be higher in selected countries, with strong national features, and is growing again in the new millennium.

Potential geographic distribution and conservation of Audubon's Shearwater, Puffinus lherminieri in Brazil

Directory of Open Access Journals (Sweden)

Ana Cecília P.A. Lopes

2014-01-01

Full Text Available Audubon's Shearwater (Puffinus lherminieri Lesson 1839 is a tropical seabird occurring mainly between southern Canada and the southeast coast of Brazil. Puffinus lherminieri is considered Critically Endangered on the Brazilian Red List because it only occurs in two known localities, both of which contain very small populations. However, many offshore islands along the Brazilian coast are poorly known and the discovery of new colonies would be of considerable significance for the conservation of this species. The aim of this study was to estimate the potential geographic distribution of Audubon's Shearwater in Brazil, based on ecological niche model (ENM using Maxent algorithm with layers obtained from AquaMaps environmental dataset. The ENM was based on 37 records for reproduction areas in North and South America. The model yielded a very broad potential distribution, covering most of the Atlantic coast ranging from Brazil to the US. When filtered for islands along the Brazilian coast, the model indicates higher levels of environmental suitability near the states of São Paulo, Rio de Janeiro, Espírito Santo and Bahia. However, P. lherminieri prefers islands in environments with warm saline water. Thus, based on the influence of currents that act on the Brazilian coast we can infer undiscovered colonies are most likely to occur on islands on coast of Bahia, Espírito Santo and extreme north of the Rio de Janeiro. These should be intensively surveyed while the islands south of Cabo Frio should be discarded. The existence of new populations would have profound effects on the conservation status of this enigmatic and rarely seen seabird.

Surveying and Mapping Geographical Information from the Perspective of Geography

Directory of Open Access Journals (Sweden)

LÜ Guonian

2017-10-01

Full Text Available It briefly reviewed the history of geographic information content development since the existence of geographic information system. It pointed out that the current definition of geographic information is always the extension from the "spatial+ attributes" basic mapping framework of geographic information. It is increasingly difficult to adapt to the analysis and application of spatial-temporal big data. From the perspective of geography research subject and content, it summarized systematically that the content and extension of the "geographic information" that geography needs. It put forward that a six-element expression model of geographic information, including spatial location, semantic description, attribute characteristics, geometric form, evolution process, and objects relationship.Under the guidance of the laws of geography, for geographical phenomenon of spatial distribution, temporal pattern and evolution process, the interaction mechanism of the integrated expression, system analysis and efficient management, it designed that a unified GIS data model which is expressed by six basic elements, a new GIS data structure driven by geographical rules and interaction, and key technologies of unstructured spatio-temporal data organization and storage. It provided that a theoretical basis and technical support for the shift from the surveying and mapping geographic information to the scientific geographic information, and it can help improving the organization, management, analysis and expression ability of the GIS of the geographical laws such as geographical pattern, evolution process, and interaction between elements.

Indoor radon concentration data: Its geographic and geologic distribution, an example from the Capital District, NY

International Nuclear Information System (INIS)

Thomas, J.J.; Overeynder, H.M.; Thomas, B.R.

1995-01-01

Most studies of the geographic distribution of indoor radon levels are plotted by county or ZIP code. This method is used for the radon potential maps produced by the U.S. Environmental Protection Agency (EPA) and the New York State Department of Health (NYSDOH). The basis for the mapping is the mean or median indoor radon count for all the data provided by NYSDOH within each geographic area. While testing the indoor radon analyses provided to the authors by CMT Independent Laboratories, we discovered data that deviated markedly from the EPA and NYSDOH means for the Capital District of New York (Albany and surrounding counties). Their screening indoor radon average concentrations in pCi/L, indicate low potential for Schenectady (3.0), Saratoga (3.2), and Albany (3.7) counties; and moderate potential for Rensselaer (6.4) and Columbia (7.0) counties. Our database of over 3,000 analyses contains over 800 records of indoor radon counts above 4 pCi/L (14-47% of each county's analyses), many high enough to be rated as a serious health hazard. In order to obtain greater precision of information, the authors plotted their indoor radon data by street address using MapInfo, a geographic Information System (GIS), and StreetInfo, MapInfo's TIGER address database. We compared the geographic distribution of our data to both the Bedrock Geology and Surficial Geology Maps of New York State. The results show a striking relationship of radon concentrations to bedrock, faults and permeability of surficial material. Data being compiled and mapped by street address by the NYSDOH in Erie County in western New York, confirm our results

Geographic distribution and clinical description of leishmaniasis cases in Peru.

Science.gov (United States)

Lucas, C M; Franke, E D; Cachay, M I; Tejada, A; Cruz, M E; Kreutzer, R D; Barker, D C; McCann, S H; Watts, D M

1998-08-01

Studies were conducted from 1986 through 1993 to further define the geographic distribution and relative importance of different species of Leishmania as a cause of leishmaniasis in Peru. Patients with a clinical diagnosis of cutaneous and/or mucosal or diffuse cutaneous leishmaniasis were enrolled at the Naval Medical Research Institute Detachment (NAMRID) Laboratory in Lima, the Tropical Disease Clinic at San Marcos University Daniel A. Carrión, the Central Military Hospital, and a Ministry of Health hospital in Cusco, Peru. Clinical features, lesion aspirates, and biopsy tissue were obtained from each patient. All specimens were collected and assayed separately, including multiple specimens from some of the same patients for Leishmania parasites by inoculating aliquots of either aspirates or biopsy tissue suspensions onto Senekji's blood agar medium. Stocks of Leishmania isolates were used to prepare promastigotes to produce extracts for identifying the Leishmania species by the cellulose acetate electrophoresis enzyme technique. A total of 351 isolates of Leishmania were obtained from 350 patients who were infected primarily in the low and high jungle of at least 15 different Departments of Peru. Of the 351 isolates, 79% were identified as L. (V.) braziliensis, 7% as L. (V.) guyanensis, 10% as L. (V.) peruviana, 2% as L. (V.) lainsoni, and 1.7% as L. (L.) amazonensis. The clinical form of disease varied depending on the species of Leishmania, with L. (V.) braziliensis being associated most frequently with cutaneous, mucosal ulcers and mixed cutaneous and mucosal disease, and L. (V) peruviana, L. (V.) guyanensis, L. (V.) lainsoni with cutaneous lesions. Leishmania (L.) amazonensis was isolated from six patients, three with cutaneous lesions, one with mucosal lesions, and two with diffuse cutaneous lesions. Among all of the leishmaniasis cases, males were affected more frequently, and cases occurred among patients less than 10 to more than 51 years of age. These

Global pyrogeography: the current and future distribution of wildfire.

Directory of Open Access Journals (Sweden)

Meg A Krawchuk

Full Text Available Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade. We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research

Global pyrogeography: the current and future distribution of wildfire.

Science.gov (United States)

Krawchuk, Meg A; Moritz, Max A; Parisien, Marc-André; Van Dorn, Jeff; Hayhoe, Katharine

2009-01-01

Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global

Mapping and Modelling the Geographical Distribution and Environmental Limits of Podoconiosis in Ethiopia

OpenAIRE

Deribe, Kebede; Cano, Jorge; Newport, Melanie J.; Golding, Nick; Pullan, Rachel L.; Sime, Heven; Gebretsadik, Abeba; Assefa, Ashenafi; Kebede, Amha; Hailu, Asrat; Rebollo, Maria P.; Shafi, Oumer; Bockarie, Moses J.; Aseffa, Abraham; Hay, Simon I.

2015-01-01

Background\\ud \\ud Ethiopia is assumed to have the highest burden of podoconiosis globally, but the geographical distribution and environmental limits and correlates are yet to be fully investigated. In this paper we use data from a nationwide survey to address these issues.\\ud \\ud Methodology\\ud \\ud Our analyses are based on data arising from the integrated mapping of podoconiosis and lymphatic filariasis (LF) conducted in 2013, supplemented by data from an earlier mapping of LF in western Et...

The impact of pesticide suicide on the geographic distribution of suicide in Taiwan: a spatial analysis.

Science.gov (United States)

Chang, Shu-Sen; Lu, Tsung-Hsueh; Sterne, Jonathan Ac; Eddleston, Michael; Lin, Jin-Jia; Gunnell, David

2012-04-02

Pesticide self-poisoning is the most commonly used suicide method worldwide, but few studies have investigated the national epidemiology of pesticide suicide in countries where it is a major public health problem. This study aims to investigate geographic variations in pesticide suicide and their impact on the spatial distribution of suicide in Taiwan. Smoothed standardized mortality ratios for pesticide suicide (2002-2009) were mapped across Taiwan's 358 districts (median population aged 15 or above = 27 000), and their associations with the size of agricultural workforce were investigated using Bayesian hierarchical models. In 2002-2009 pesticide poisoning was the third most common suicide method in Taiwan, accounting for 13.6% (4913/36 110) of all suicides. Rates were higher in agricultural East and Central Taiwan and lower in major cities. Almost half (47%) of all pesticide suicides occurred in areas where only 13% of Taiwan's population lived. The geographic distribution of overall suicides was more similar to that of pesticide suicides than non-pesticide suicides. Rural-urban differences in suicide were mostly due to pesticide suicide. Areas where a higher proportion of people worked in agriculture showed higher pesticide suicide rates (adjusted rate ratio [ARR] per standard deviation increase in the proportion of agricultural workers = 1.58, 95% Credible Interval [CrI] 1.44-1.74) and overall suicide rates (ARR = 1.06, 95% CrI 1.03-1.10) but lower non-pesticide suicide rates (ARR = 0.91, 95% CrI 0.87-0.95). Easy access to pesticides appears to influence the geographic distribution of suicide in Taiwan, highlighting the potential benefits of targeted prevention strategies such as restricting access to highly toxic pesticides.

Advanced model for expansion of natural gas distribution networks based on geographic information systems

Energy Technology Data Exchange (ETDEWEB)

Ramirez-Rosado, I.J.; Fernandez-Jimenez, L.A.; Garcia-Garrido, E.; Zorzano-Santamaria, P.; Zorzano-Alba, E. [La Rioja Univ., La Rioja (Spain). Dept. of Electrical Engineering; Miranda, V.; Montneiro, C. [Porto Univ., Porto (Portugal). Faculty of Engineering]|[Inst. de Engenharia de Sistemas e Computadores do Porto, Porto (Portugal)

2005-07-01

An advanced geographic information system (GIS) model of natural gas distribution networks was presented. The raster-based model was developed to evaluate costs associated with the expansion of electrical networks due to increased demand in the La Rioja region of Spain. The model was also used to evaluate costs associated with maintenance and amortization of the already existing distribution network. Expansion costs of the distribution network were modelled in various demand scenarios. The model also considered a variety of technical factors associated with pipeline length and topography. Soil and slope data from previous pipeline projects were used to estimate real costs per unit length of pipeline. It was concluded that results obtained by the model will be used by planners to select zones where expansion is economically feasible. 4 refs., 5 figs.

TNT Maritime Interdiction Operation Experiments: Enabling Radiation Awareness and Geographically Distributed Collaboration for Network-Centric Maritime Interdiction Operations [Preprint

National Research Council Canada - National Science Library

Bordetsky, Alex; Dougan, Arden; Chiann, Foo Y; Kilberg, Andres

2007-01-01

...) comprised of long-haul OFDM networks combined with self-forming wireless mesh links to radiation detection sensors, and real-time radiation awareness collaboration with geographically distributed partners...

[Predicting the impact of global warming on the geographical distribution pattern of Quercus variabilis in China].

Science.gov (United States)

Li, Yao; Zhang, Xing-wang; Fang, Yan-ming

2014-12-01

The geographical distribution of Quercus variabilis in China with its climate characteristics was analyzed based on DIVA-GIS which was also used to estimate the response of future potential distribution to global warming by Bioclim and Domain models. Analysis results showed the geographical distribution of Q. variabilis could be divided into 7 subregions: Henduan Mountains, Yunnan-Guizhou Plateau, North China, East China, Liaodong-Shandong Peninsula, Taiwan Island, and Qinling-Daba Mountains. These subregions are across 7 temperature zones, 2 moisture regions and 17 climatic subregions, including 8 climate types. The modern abundance center of Q. variabilis is Qinling, Daba and Funiu mountains. The condition of mean annual temperature 7.5-19.8 degrees C annual precipitation 471-1511 mm, is suitable for Q. variabilis. Areas under the receiver operating characteristic curve (AUC values), of Domain and Boiclim models were 0.910, 0.779; the former predicted that the potential regions of high suitability for Q. variabilis are Qinling, Daba, Funiu, Tongbai, and Dabie mountains, eastern and western Yunnan-Guizhou Plateau, hills of southern Jiangsu and Anhui, part of the mountains in North China. Global warming might lead to the shrinking in suitable region and retreating from the south for Q. variabilis.

The Distribution of Heavy Metal Pollutants in Suez Bay Using Geographic Information System (GIS)

International Nuclear Information System (INIS)

Hassan, H.B.; Mohamed, W.M.

2017-01-01

Suez city represents the southern entrance of the Suez Canal. As a result of the rapid development of industrialization and anthropogenic activities of Suez city may be entered containments such as heavy metals through Suez bay boundaries. The geographical information system (Arc GIS 9.1) is used to study the spatial distribution of heavy metals concentrations (Cd, Mn, Fe, Ni, Pb, Cu and Zn) of water samples which were collected in four different sampling sites (I, II, III and IV) from Suez bay. In this study, tabular data representation of the spatial distribution was developed using the inverse distance weighted (IDW) interpolation method. The GIS technique was applied to transfer the information into a final map illustrating the spatial distribution of heavy metals within the studied area. GIS models showed the high concentrations of heavy metals in some sites in the Suez city affecting by their activities. An overall distribution map of heavy metals is observed from GIS special analysis. Site (IV) in Suez City demonstrated the highest polluted are a in the overall distribution map

Understanding the geographic distribution of tropical cyclone formation for applications in climate models

Science.gov (United States)

Tory, Kevin J.; Ye, H.; Dare, R. A.

2018-04-01

Projections of Tropical cyclone (TC) formation under future climate scenarios are dependent on climate model simulations. However, many models produce unrealistic geographical distributions of TC formation, especially in the north and south Atlantic and eastern south Pacific TC basins. In order to improve confidence in projections it is important to understand the reasons behind these model errors. However, considerable effort is required to analyse the many models used in projection studies. To address this problem, a novel diagnostic is developed that provides compelling insight into why TCs form where they do, using a few summary diagrams. The diagnostic is developed after identifying a relationship between seasonal climatologies of atmospheric variables in 34 years of ECMWF reanalysis data, and TC detection distributions in the same data. Geographic boundaries of TC formation are constructed from four threshold quantities. TCs form where Emanuel's Maximum Potential Intensity, V_{{PI}}, exceeds 40 {ms}^{{ - 1}}, 700 hPa relative humidity, RH_{{700}}, exceeds 40%, and the magnitude of the difference in vector winds between 850 and 200 hPa, V_{{sh}}, is less than 20 {ms}^{{ - 1}}. The equatorial boundary is best defined by a composite quantity containing the ratio of absolute vorticity (η ) to the meridional gradient of absolute vorticity (β ^{*}), rather than η alone. {β ^*} is also identified as a potentially important ingredient for TC genesis indices. A comparison of detected Tropical Depression (TD) and Tropical Storm (TS) climatologies revealed TDs more readily intensify further to TS where {V_{PI}} is elevated and {V_{sh}} is relatively weak. The distributions of each threshold quantity identify the factors that favour and suppress TC formation throughout the tropics in the real world. This information can be used to understand why TC formation is poorly represented in some climate models, and shows potential for understanding anomalous TC formation

Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe

Directory of Open Access Journals (Sweden)

Medlock Jolyon M

2013-01-01

Full Text Available Abstract Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick’s geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.

The impact of pesticide suicide on the geographic distribution of suicide in Taiwan: a spatial analysis

Directory of Open Access Journals (Sweden)

Chang Shu-Sen

2012-04-01

Full Text Available Abstract Background Pesticide self-poisoning is the most commonly used suicide method worldwide, but few studies have investigated the national epidemiology of pesticide suicide in countries where it is a major public health problem. This study aims to investigate geographic variations in pesticide suicide and their impact on the spatial distribution of suicide in Taiwan. Methods Smoothed standardized mortality ratios for pesticide suicide (2002-2009 were mapped across Taiwan's 358 districts (median population aged 15 or above = 27 000, and their associations with the size of agricultural workforce were investigated using Bayesian hierarchical models. Results In 2002-2009 pesticide poisoning was the third most common suicide method in Taiwan, accounting for 13.6% (4913/36 110 of all suicides. Rates were higher in agricultural East and Central Taiwan and lower in major cities. Almost half (47% of all pesticide suicides occurred in areas where only 13% of Taiwan's population lived. The geographic distribution of overall suicides was more similar to that of pesticide suicides than non-pesticide suicides. Rural-urban differences in suicide were mostly due to pesticide suicide. Areas where a higher proportion of people worked in agriculture showed higher pesticide suicide rates (adjusted rate ratio [ARR] per standard deviation increase in the proportion of agricultural workers = 1.58, 95% Credible Interval [CrI] 1.44-1.74 and overall suicide rates (ARR = 1.06, 95% CrI 1.03-1.10 but lower non-pesticide suicide rates (ARR = 0.91, 95% CrI 0.87-0.95. Conclusion Easy access to pesticides appears to influence the geographic distribution of suicide in Taiwan, highlighting the potential benefits of targeted prevention strategies such as restricting access to highly toxic pesticides.

Quantitative Study of the Geographical Distribution of the Authorship of High-Energy Physics Journals

CERN Document Server

Krause, Jan; Mele, S

2007-01-01

The recent debate on Open Access publishing in High-Energy Physics has exposed the problem of assessing the scienti c production of every country where scholars are active in this discipline. This assessment is complicated by the highly-collaborative cross-border tradition of High-Energy Physics research. We present the results of a quantitative study of the geographical distribution of authors of High-Energy Physics articles, which takes into account cross-border co-authorship by attributing articles to countries on a pro-rata basis. Aggregated data on the share of scienti c results published by each country are presented together with a breakdown for the most popular journals in the eld, and a separation for articles by small groups or large collaborations. Collaborative patterns across large geographic areas are also investigated. Finally, the High-Energy Physics production of each country is compared with some economic indicators.

Managing Risks in Distributed Software Projects: An Integrative Framework

DEFF Research Database (Denmark)

Persson, John Stouby; Mathiassen, Lars; Boeg, Jesper

2009-01-01

techniques into an integrative framework for managing risks in distributed contexts. Subsequent implementation of a Web-based tool helped us refine the framework based on empirical evaluation of its practical usefulness.We conclude by discussing implications for both research and practice.......Software projects are increasingly geographically distributed with limited face-to-face interaction between participants. These projects face particular challenges that need carefulmanagerial attention. While risk management has been adopted with success to address other challenges within software...... development, there are currently no frameworks available for managing risks related to geographical distribution. On this background, we systematically review the literature on geographically distributed software projects. Based on the review, we synthesize what we know about risks and risk resolution...

[Geographic distribution of birds in the Sierra Madre Oriental of San Luis Potosi, Mexico: a regional analysis of conservation status].

Science.gov (United States)

Sahagún Sánchez, Francisco Javier; Navarro, Jaime Castro; Reyes Hernández, Humberto

2013-06-01

The Sierra Madre Oriental region in the mexican state of San Luis Potosi is a relevant place for bird conservation at a country level. Therefore the main goal of this study was to analyze the geographic patterns of distribution and the conservation current state of the birds, to support the needs to expand the conservation areas in the future. Data was collected from various databases of zoological museums and collections, and field sampling methods conducted from January 2009 to May 2011. Potential distributions were modeled for 284 species using GARP software and then a map was developed to determine areas with favorable environmental characteristics for the distribution of species richness. Finally, the importance of conservation areas for the potential distribution of birds in the region was evaluated. A total of 359 species were recorded of which 71.4% are permanent residents, 19% are winter migrants and 4% are summer residents. From this total, 41 species were endemic, 47 were species at risk and 149 were neotropical migrants. The largest species richness correspond to oak forests, cloud forests, and tropical moist forests located at altitudes from 100m to 1 500m. Their potential distribution was concentrated towards the center and Southeast of the study area. Only 10% of areas with a high potential conservation was included in areas of priority for bird conservation (AICA) and just 3% of all potential areas were under some governmental category of protection. However, no conservation area has a management plan currently applied and monitored. The information generated is important for the development of management proposals for birds conservation in the region.

Random-growth urban model with geographical fitness

Science.gov (United States)

Kii, Masanobu; Akimoto, Keigo; Doi, Kenji

2012-12-01

This paper formulates a random-growth urban model with a notion of geographical fitness. Using techniques of complex-network theory, we study our system as a type of preferential-attachment model with fitness, and we analyze its macro behavior to clarify the properties of the city-size distributions it predicts. First, restricting the geographical fitness to take positive values and using a continuum approach, we show that the city-size distributions predicted by our model asymptotically approach Pareto distributions with coefficients greater than unity. Then, allowing the geographical fitness to take negative values, we perform local coefficient analysis to show that the predicted city-size distributions can deviate from Pareto distributions, as is often observed in actual city-size distributions. As a result, the model we propose can generate a generic class of city-size distributions, including but not limited to Pareto distributions. For applications to city-population projections, our simple model requires randomness only when new cities are created, not during their subsequent growth. This property leads to smooth trajectories of city population growth, in contrast to other models using Gibrat’s law. In addition, a discrete form of our dynamical equations can be used to estimate past city populations based on present-day data; this fact allows quantitative assessment of the performance of our model. Further study is needed to determine appropriate formulas for the geographical fitness.

Temperature effects on gametophyte life-history traits and geographic distribution of two cryptic kelp species.

Directory of Open Access Journals (Sweden)

L Valeria Oppliger

Full Text Available A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29-30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1 estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2 compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed.

Diversity, natural history, and geographic distribution of snakes in the Caatinga, Northeastern Brazil.

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Guedes, Thaís B; Nogueira, Cristiano; Marques, Otavio A V

2014-09-19

The present study is a synthesis on snake diversity and distribution in the Caatinga region of northeastern Brazil, providing an updated species list and data on natural history and geographic distribution. Our study is based on the careful revision of 7,102 voucher specimens, housed in 17 herpetological collections, complemented by data on taxonomic literature. We recorded a total of 112 snake species in the Caatinga, belonging to nine families: Anomalepididae, Leptotyphlopidae, Typhlopidae, Aniliidae, Boidae, Viperidae, Elapidae, Colubridae, and Dipsadidae. Our list includes at least 13 never recorded species for this region, as well as distribution records for all species known from the Caatinga (including expansion and new records of distribution). The snake assemblage of the Caatinga is complex, sharing species with other continental open areas (38.4%), forested areas (27.7%), and both open and forested areas (32.1%). The richest areas were isolated plateaus, followed by contact areas, semi-arid caatinga, and sandy dunes of the São Franscisco River. We identified 22 Caatinga endemic species with the sandy dunes of São Franscico River showing the highest endemism level (12 species, with six endemic species restricted to the area) followed by semi-arid caatinga, and isolated plateaus (eight endemic species each, and six and three endemic species with restricted distribution to each area, respectively). Most species show relatively restricted ranges in parts of the Caatinga. The snake assemblage in Caatinga includes mainly terrestrial species (38.4%), followed by fossorial/cryptozoic (26.8%), arboreal/semi-arboreal (26.8%), and aquatic/semi-aquatic (7.1%) species. Vertebrates are the most important dietary item (80.4%), with 56.6% of species being generalist consumers of this kind of prey; 24.4% are frog-eaters, 7.8% prey on caecilians/amphisbaenians, 6.7% lizard-eaters, 3.3% mammal-eaters, and 1.1% are fish-eaters. Only 18.7% of the snakes eat invertebrate

Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

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Yu-San Han

Full Text Available Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

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Han, Yu-San; Yambot, Apolinario V; Zhang, Heng; Hung, Chia-Ling

2012-01-01

Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

Geographical distribution of a specific mitochondrial haplotype of Zymoseptoria tritici

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Sameh BOUKEF

2014-01-01

Full Text Available Severity of disease caused by the fungus Zymoseptoria tritici throughout world cereal growing regions has elicited much debate on the potential evolutionary mechanism conferring high adaptability of the pathogen to diverse climate conditions and different wheat hosts (Triticum durum and T. aestivum. Specific mitochondrial DNA sequence was used to investigate geographic distribution of the type 4 haplotype (mtRFLP4 within 1363 isolates of Z. tritici originating from 21 countries. The mtRFLP4 haplotype was detected from both durum and bread wheat hosts with greater frequency on durum wheat. The distribution of mtRFLP4 was limited to populations sampled from the Mediterranean and the Red Sea region. Greater frequencies of mtRFLP4 were found in Tunisia (87% and Algeria (60%. The haplotype was absent within European, Australian, North and South American populations except Argentina. While alternative hypotheses such as climatic adaptation could not be ruled out, it is postulated that mtRFLP4 originated in North Africa (e.g. Tunisia or Algeria as an adaptation to durum wheat as the prevailing cereal crop. The specialized haplotype has subsequently spread as indicated by lower frequency of occurrence in the surrounding Mediterranean countries and on bread wheat hosts.

Ethnic and geographic variations in HPV prevalence and genotype distribution in north-western Yunnan, China.

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Baloch, Zulqarnain; Yuan, Tao; Wang, Binghui; Tai, Wenlin; Feng, Yue; Liu, Yanqing; Li, Xiao; Feng, Yue; Liu, Li; Zhang, A-mei; Wu, Xiaomei; Xia, Xueshan

2016-03-01

The prevalence and genotype distribution of human papillomavirus (HPV) vary throughout the world. To assess the prevalence and genotype distribution of HPV among three ethnic groups in two geographic locations in north-western Yunnan, we recruited 522 women in Shangri-le (n = 255) and Lijiang (n = 267). PCR amplification of HPV DNA was performed on cervical cells from these women using two consensus primer systems (MY09/11 and GP5/6). Amplified-HPV DNA was genotyped using the HPV GenoArray test. Geographically, the HPV prevalence was significantly higher (P = 0.002) among Shangri-le women than among Lijiang women. Infections with high-risk (HR)-HPV and with multiple HPV genotypes were also significantly more common (P = 0.001) among women in Shangri-le than women in Lijiang. Additionally, the prevalence of overall, HR-HPV, and single genotype HPV infections was significantly higher (P = 0.001) among Tibetan women than among Naxi and Han women. HPV-16 and HPV-33 were significantly more frequent in Shangri-le women compared with Lijiang (P = 0.006) women. In addition, HPV-16 (9.81%) and HPV-33 (5.88%) were significantly more prevalent in Tibetan women than in Naxi and Han women. Here, for the first time, we highlight the significant variation in the prevalence and genotype distribution of HPV in various populations in the north-western region of Yunnan Province. © 2015 Wiley Periodicals, Inc.

Geographic information system-coupling sediment delivery distributed modeling based on observed data.

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Lee, S E; Kang, S H

2014-01-01

Spatially distributed sediment delivery (SEDD) models are of great interest in estimating the expected effect of changes on soil erosion and sediment yield. However, they can only be applied if the model can be calibrated using observed data. This paper presents a geographic information system (GIS)-based method to calculate the sediment discharge from basins to coastal areas. For this, an SEDD model, with a sediment rating curve method based on observed data, is proposed and validated. The model proposed here has been developed using the combined application of the revised universal soil loss equation (RUSLE) and a spatially distributed sediment delivery ratio, within Model Builder of ArcGIS's software. The model focuses on spatial variability and is useful for estimating the spatial patterns of soil loss and sediment discharge. The model consists of two modules, a soil erosion prediction component and a sediment delivery model. The integrated approach allows for relatively practical and cost-effective estimation of spatially distributed soil erosion and sediment delivery, for gauged or ungauged basins. This paper provides the first attempt at estimating sediment delivery ratio based on observed data in the monsoon region of Korea.

Changes in the geographical distribution of plant species and climatic variables on the West Cornwall peninsula (South West UK).

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Kosanic, Aleksandra; Anderson, Karen; Harrison, Stephan; Turkington, Thea; Bennie, Jonathan

2018-01-01

Recent climate change has had a major impact on biodiversity and has altered the geographical distribution of vascular plant species. This trend is visible globally; however, more local and regional scale research is needed to improve understanding of the patterns of change and to develop appropriate conservation strategies that can minimise cultural, health, and economic losses at finer scales. Here we describe a method to manually geo-reference botanical records from a historical herbarium to track changes in the geographical distributions of plant species in West Cornwall (South West England) using both historical (pre-1900) and contemporary (post-1900) distribution records. We also assess the use of Ellenberg and climate indicator values as markers of responses to climate and environmental change. Using these techniques we detect a loss in 19 plant species, with 6 species losing more than 50% of their previous range. Statistical analysis showed that Ellenberg (light, moisture, nitrogen) and climate indicator values (mean January temperature, mean July temperature and mean precipitation) could be used as environmental change indicators. Significantly higher percentages of area lost were detected in species with lower January temperatures, July temperatures, light, and nitrogen values, as well as higher annual precipitation and moisture values. This study highlights the importance of historical records in examining the changes in plant species' geographical distributions. We present a method for manual geo-referencing of such records, and demonstrate how using Ellenberg and climate indicator values as environmental and climate change indicators can contribute towards directing appropriate conservation strategies.

Changes in the geographical distribution of plant species and climatic variables on the West Cornwall peninsula (South West UK)

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Kosanic, Aleksandra; Anderson, Karen; Harrison, Stephan; Turkington, Thea; Bennie, Jonathan

2018-01-01

Recent climate change has had a major impact on biodiversity and has altered the geographical distribution of vascular plant species. This trend is visible globally; however, more local and regional scale research is needed to improve understanding of the patterns of change and to develop appropriate conservation strategies that can minimise cultural, health, and economic losses at finer scales. Here we describe a method to manually geo-reference botanical records from a historical herbarium to track changes in the geographical distributions of plant species in West Cornwall (South West England) using both historical (pre-1900) and contemporary (post-1900) distribution records. We also assess the use of Ellenberg and climate indicator values as markers of responses to climate and environmental change. Using these techniques we detect a loss in 19 plant species, with 6 species losing more than 50% of their previous range. Statistical analysis showed that Ellenberg (light, moisture, nitrogen) and climate indicator values (mean January temperature, mean July temperature and mean precipitation) could be used as environmental change indicators. Significantly higher percentages of area lost were detected in species with lower January temperatures, July temperatures, light, and nitrogen values, as well as higher annual precipitation and moisture values. This study highlights the importance of historical records in examining the changes in plant species’ geographical distributions. We present a method for manual geo-referencing of such records, and demonstrate how using Ellenberg and climate indicator values as environmental and climate change indicators can contribute towards directing appropriate conservation strategies. PMID:29401494

Relative importance of meteorological and geographical factors in the distribution of Fasciola hepatica infestation in farmed sheep in Qinghai province, China

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Qin Hongyu

2016-01-01

Full Text Available Fasciola hepatica is an important trematode parasite of economic importance that infests sheep and cattle worldwide. We conducted a detailed investigation into the spatial distribution of F. hepatica infestation in farmed sheep in Qinghai (Wutumeiren province, Mainland China. Mathematical modelling was used to assess the inter-relationships between meteorological and geographical factors and the risk of F. hepatica infestation across the province. A capture enzyme-linked immunosorbent assay (ELISA test (MM3-SERO was used to detect F. hepatica infestation. A niche model based on the maximum entropy method (MaxEnt was used to estimate the influence of meteorological and geographical factors on the observed spatial distribution of F. hepatica infestation. Results of jackknife analysis indicated that temperature, precipitation, solar radiation, digital elevation and slope were associated with the occurrence of F. hepatica infestation, and that infestation rates were significantly higher among animals from districts with a high percentage of grassland habitat. The findings indicate that meteorological and geographical factors may be important variables affecting the distribution of F. hepatica infestation and should be taken into account in the development of future surveillance and control programmes for fascioliasis.

[Current progress in food geographical origin traceability by near infrared spectroscopy technology].

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Ma, Dong-Hong; Wang, Xi-Chang; Liu, Li-Ping; Liu, Yuan

2011-04-01

The geographical origin traceability of food, an important part of traceability system, is effective in protecting the quality and safety of foodstuffs. Near-infrared spectroscopy (NIR), which is a powerful technique for geographical origin traceability, has attracted extensive attention by scientists due to its speediness, non-pollution and simple operation. This paper presents the advantages and disadvantages of techniques that have been used for food geographical origin traceability. The basic principles of NIR and its applications in different food geographical origin traceability are presented too. Furthermore, problems in applications are analyzed and the future development trends are discussed.

Geographic distribution of childhood diabetes and obesity relative to the supply of pediatric endocrinologists in the United States.

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Lee, Joyce M; Davis, Matthew M; Menon, Ram K; Freed, Gary L

2008-03-01

To determine the geographic distribution of childhood diabetes and obesity relative to the supply of US pediatric endocrinologists. Estimation of observed and "index" ratios of children with diabetes (by region and division) and obesity (body mass index >/=95th % for age and sex) (by region and state) to board-certified pediatric endocrinologists. At the national level, the ratio of children with diabetes to pediatric endocrinologists is 290:1, and the ratio of obese children to pediatric endocrinologists is 17,741:1. Ratios of children with diabetes to pediatric endocrinologists in the Midwest (370:1), South (335:1), and West (367:1) are twice as high as in the Northeast (144:1). Across states, there is up to a 19-fold difference in the observed ratios of obese children to pediatric endocrinologists. Under conditions of equitably distributed endocrinologist supply, variation across states would be mitigated considerably. The distribution of children with diabetes and obesity does not parallel the distribution of pediatric endocrinologists in the United States, due largely to geographic disparities in endocrinologist supply. Given the large burden of obese children to endocrinologists, multidisciplinary models of care delivery are essential for the US health care system to address the needs of children with diabetes and obesity.

Fine scale distribution constrains cadmium accumulation rates in two geographical groups of Franciscana dolphin from Argentina

International Nuclear Information System (INIS)

Polizzi, P.S.; Chiodi Boudet, L.N.; Romero, M.B.; Denuncio, P.E.; Rodríguez, D.H.

2013-01-01

Highlights: • Fine scale distribution of two Argentine stocks constrains the Cd accumulation rates. • Cadmium levels and accumulation patterns were different between geographic groups. • Marine diet has a major influence than the impact degree of origin environment. • Engraulis anchoita is the main Cd vector species in Argentine shelf for Franciscana. • Information is valuable for the conservation of Franciscana, a vulnerable species. -- Abstract: Franciscana dolphin is an endemic cetacean in the southwestern Atlantic Ocean and is classified as Vulnerable A3d by the International Union for Conservation of Nature. Cadmium accumulation was assessed in two geographic groups from Argentina; one inhabits the La Plata River estuary, a high anthropogenic impacted environment, and the other is distributed in marine coastal, with negligible pollution. Despite the environment, marine dolphins showed an increase of renal Cd concentrations since trophic independence; while in estuarine dolphins was from 6 years. This is associated with dietary Argentine anchovy which was absent in the diet of estuarine dolphins, being a trophic vector of cadmium in shelf waters of Argentina. Cluster analysis also showed high levels of cd in association with the presence of anchovy in the stomach. The difference in the fine scale distribution of species influences dietary exposure to Cd and, along with other data, indicates two stocks in Argentina

Comparison of geographic distributions of Irritable Bowel Syndrome with Inflammatory Bowel Disease fail to support common evolutionary roots: Irritable Bowel Syndrome and Inflammatory Bowel Diseases are not related by evolution.

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Szilagyi, Andrew; Xue, Xiaoqing

2018-01-01

Irritable Bowel Syndrome (IBS) shares overlapping symptoms and some features of pathogenesis with Inflammatory Bowel Diseases (IBD: Crohn's disease [CD], and Ulcerative Colitis [UC]). Geographic markers such as latitude/sunshine and more recently lactase population distributions are found to be correlated with IBD. As a result of clinical and pathogenic similarities between the 2 conditions, some authorities questioned whether a connection exists between them. We compare IBS directly with IBD, and indirectly with geographic markers associated with IBD, in order to evaluate possible evolutionary links between IBS and IBD. Similar correlations may link IBS as a precursor to IBD and possibly other conditions which are geographically connected with IBD. Data from four systematic reviews on IBD incidence and prevalence, IBS prevalence, and lactase distributions were included. Pearson's correlations were used for comparisons, with IBD values log-transformed because of skewed distribution. The articles provided 18-28 complete set of national data. Direct comparison between IBS and IBD showed no significant correlations (r = -0.14, r = -0.06 for CD and UC prevalence, r = -0.10 for CD incidence). Indirect comparisons also failed to show correlations of IBS with lactase distributions (r = -0.17), sunshine (r = -0.2) or latitude (r = 0.097); however, there was significant correlation between lactase distributions and CD incidence (r = -0.84), prevalence (r = -0.55) and UC prevalence (r = -0.59). Both sunshine (r= -0.53) and latitude (r = 0.58) are also significantly related to CD incidence. It is concluded that IBS and IBD do not follow similar global geographic patterns. This suggests a lack of an evolutionary genetic background coincident with emergence of lactase persistence. As well, vitamin D has no obvious impact on development of IBS. Similarities with IBD may result from sub groups (not yet identified) within the current Rome

Modelling the geographical distribution of soil-transmitted helminth infections in Bolivia.

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Chammartin, Frédérique; Scholte, Ronaldo G C; Malone, John B; Bavia, Mara E; Nieto, Prixia; Utzinger, Jürg; Vounatsou, Penelope

2013-05-25

The prevalence of infection with the three common soil-transmitted helminths (i.e. Ascaris lumbricoides, Trichuris trichiura, and hookworm) in Bolivia is among the highest in Latin America. However, the spatial distribution and burden of soil-transmitted helminthiasis are poorly documented. We analysed historical survey data using Bayesian geostatistical models to identify determinants of the distribution of soil-transmitted helminth infections, predict the geographical distribution of infection risk, and assess treatment needs and costs in the frame of preventive chemotherapy. Rigorous geostatistical variable selection identified the most important predictors of A. lumbricoides, T. trichiura, and hookworm transmission. Results show that precipitation during the wettest quarter above 400 mm favours the distribution of A. lumbricoides. Altitude has a negative effect on T. trichiura. Hookworm is sensitive to temperature during the coldest month. We estimate that 38.0%, 19.3%, and 11.4% of the Bolivian population is infected with A. lumbricoides, T. trichiura, and hookworm, respectively. Assuming independence of the three infections, 48.4% of the population is infected with any soil-transmitted helminth. Empirical-based estimates, according to treatment recommendations by the World Health Organization, suggest a total of 2.9 million annualised treatments for the control of soil-transmitted helminthiasis in Bolivia. We provide estimates of soil-transmitted helminth infections in Bolivia based on high-resolution spatial prediction and an innovative variable selection approach. However, the scarcity of the data suggests that a national survey is required for more accurate mapping that will govern spatial targeting of soil-transmitted helminthiasis control.

Age and Geographical Distribution in Families with BRCA1/BRCA2 Mutations in the Slovak Republic

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Ciernikova Sona

2006-12-01

Full Text Available Abstract Molecular diagnostics of hereditary breast and/or ovarian cancer is mainly based on detection of BRCA1 and BRCA2 germline mutations in suspected families. The aim of the study was to determine the frequency, age and geographical distribution in 130 Slovak hereditary breast and ovarian cancer (HBOC families diagnosed within the years 2000-2004. Mutation screening was performed by single-strand conformation polymorphism (SSCP, heteroduplex analysis (HDA and sequencing of PCR products showing an abnormal migration pattern. Twenty of 130 (15.6% HBOC suspected families were found to carry mutations in BRCA1 or BRCA2 genes. The glossary data from the National Cancer Registry of Slovakia (NCRS were compared with the results from HBOC suspected kindreds. Age distribution of breast cancer onset in our study group showed the highest proportion of onset in HBC families within the 5th decade of life, while NCRS reports at least a ten year later onset. These findings confirmed that cases of breast cancer under 50 years of age can be used as one of the principal criteria to assign a family as a hereditary breast and/or ovarian cancer kindred. In contrast with unselected ovarian cancer cases, about 75% of all HOC index cases were diagnosed between 40 and 49 years of age. To study the geographical distribution of hereditary breast and/or ovarian cancer, Slovakia was divided into three parts. The distribution of HBOC suspected families approximately follows this division, with an increasing number in the western area of the country.

Multiple sclerosis: a geographical hypothesis.

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Carlyle, I P

1997-12-01

Multiple sclerosis remains a rare neurological disease of unknown aetiology, with a unique distribution, both geographically and historically. Rare in equatorial regions, it becomes increasingly common in higher latitudes; historically, it was first clinically recognized in the early nineteenth century. A hypothesis, based on geographical reasoning, is here proposed: that the disease is the result of a specific vitamin deficiency. Different individuals suffer the deficiency in separate and often unique ways. Evidence to support the hypothesis exists in cultural considerations, in the global distribution of the disease, and in its historical prevalence.

Determination of distribution pattern of the heavy metal concentrations in the potable network of Gachsaran by Geographical Information System (GIS

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G Paraham

2013-12-01

. Methods: In this descriptive, cross-sectional study, samples were taken from11 spots of the drinking water distribution network and tested for concentration of 10 metals by Inductivity Coupled Ions Plasma (ICP method in summer of 2010. The research data were compared with national and international water standards. Then the distribution map of heavy metals concentrations in the drinking water wells of the region was prepared by using the Geographical Information System (GIS software. Data were analyzed by the Kruskal-Wallis tests. Results: In all samples, the average concentration of heavy metals were: Arsenic 0.54, Cadmium 0.05, Zinc 55.9, Lead 0.18, Copper .82, Chromium 1.6, Barium 36.5, Selenium0.5, Mercury 0.1 and Silver 0.05 micrograms per liter and was less than the water quality standard. Conclusion: Based on the results obtained, it can be concluded that concentrations of heavy metals in Gachsaran’s drinking water distribution network are not higher than national and international standards and therefore not harmful for people. Key words: Heavy metals, Distribution network, Gachsaran, geographical information system (GIS

Temporal, geographic, and host distribution of avian paramyxovirus 1 (Newcastle disease virus)

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Dimitrov, Kiril M.; Ramey, Andy M.; Qiu, Xueting; Bahl, Justin; Afonso, Claudio L.

2016-01-01

Newcastle disease is caused by virulent forms of avian paramyxovirus of serotype 1 (APMV-1) and has global economic importance. The disease reached panzootic proportions within two decades after first being identified in 1926 in the United Kingdom and Indonesia and still remains endemic in many countries across the world. Here we review information on the host, temporal, and geographic distribution of APMV-1 genetic diversity based on the evolutionary systematics of the complete coding region of the fusion gene. Strains of APMV-1 are phylogenetically separated into two classes (class I and class II) and further classified into genotypes based on genetic differences. Class I viruses are genetically less diverse, generally present in wild waterfowl, and are of low virulence. Class II viruses are genetically and phenotypically more diverse, frequently isolated from poultry with occasional spillovers into wild birds, and exhibit a wider range of virulence. Waterfowl, cormorants, and pigeons are natural reservoirs of all APMV-1 pathotypes, except viscerotropic velogenic viruses for which natural reservoirs have not been identified. Genotypes I and II within class II include isolates of high and low virulence, the latter often being used as vaccines. Viruses of genotypes III and IX that emerged decades ago are now isolated rarely, but may be found in domestic and wild birds in China. Containing only virulent viruses and responsible for the majority of recent outbreaks in poultry and wild birds, viruses from genotypes V, VI, and VII, are highly mobile and have been isolated on different continents. Conversely, virulent viruses of genotypes XI (Madagascar), XIII (mainly Southwest Asia), XVI (North America) and XIV, XVII and XVIII (Africa) appear to have a more limited geographic distribution and have been isolated predominantly from poultry.

Impact of uniform electrode current distribution on ETF

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Bents, D. J.

1982-01-01

The design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution are examined and the alternate consolidation design which occur are presented compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is given for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

Alcohol beverage control, privatization and the geographic distribution of alcohol outlets

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Grubesic Tony H

2012-11-01

Full Text Available Abstract Background With Pennsylvania currently considering a move away from an Alcohol Beverage Control state to a privatized alcohol distribution system, this study uses a spatial analytical approach to examine potential impacts of privatization on the number and spatial distribution of alcohol outlets in the city of Philadelphia over a long time horizon. Methods A suite of geospatial data were acquired for Philadelphia, including 1,964 alcohol outlet locations, 569,928 land parcels, and school, church, hospital, park and playground locations. These data were used as inputs for exploratory spatial analysis to estimate the expected number of outlets that would eventually operate in Philadelphia. Constraints included proximity restrictions (based on current ordinances regulating outlet distribution of at least 200 feet between alcohol outlets and at least 300 feet between outlets and schools, churches, hospitals, parks and playgrounds. Results Findings suggest that current state policies on alcohol outlet distributions in Philadelphia are loosely enforced, with many areas exhibiting extremely high spatial densities of outlets that violate existing proximity restrictions. The spatial model indicates that an additional 1,115 outlets could open in Philadelphia if privatization was to occur and current proximity ordinances were maintained. Conclusions The study reveals that spatial analytical approaches can function as an excellent tool for contingency-based “what-if” analysis, providing an objective snapshot of potential policy outcomes prior to implementation. In this case, the likely outcome is a tremendous increase in alcohol outlets in Philadelphia, with concomitant negative health, crime and quality of life outcomes that accompany such an increase.

Optimizing Geographic Allotment of Photovoltaic Capacity in a Distributed Generation Setting: Preprint

Energy Technology Data Exchange (ETDEWEB)

Urquhart, B.; Sengupta, M.; Keller, J.

2012-09-01

A multi-objective optimization was performed to allocate 2MW of PV among four candidate sites on the island of Lanai such that energy was maximized and variability in the form of ramp rates was minimized. This resulted in an optimal solution set which provides a range of geographic allotment alternatives for the fixed PV capacity. Within the optimal set, a tradeoff between energy produced and variability experienced was found, whereby a decrease in variability always necessitates a simultaneous decrease in energy. A design point within the optimal set was selected for study which decreased extreme ramp rates by over 50% while only decreasing annual energy generation by 3% over the maximum generation allocation. To quantify the allotment mix selected, a metric was developed, called the ramp ratio, which compares ramping magnitude when all capacity is allotted to a single location to the aggregate ramping magnitude in a distributed scenario. The ramp ratio quantifies simultaneously how much smoothing a distributed scenario would experience over single site allotment and how much a single site is being under-utilized for its ability to reduce aggregate variability. This paper creates a framework for use by cities and municipal utilities to reduce variability impacts while planning for high penetration of PV on the distribution grid.

The Geographic Distribution of Liver Cancer in Canada Does Not Associate with Cyanobacterial Toxin Exposure

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Meaghan A. Labine

2015-11-01

Full Text Available Background: The incidence of liver cancer has been increasing in Canada over the past decade, as has cyanobacterial contamination of Canadian freshwater lakes and drinking water sources. Cyanotoxins released by cyanobacteria have been implicated in the pathogenesis of liver cancer. Objective: To determine whether a geographic association exists between liver cancer and surrogate markers of cyanobacterial contamination of freshwater lakes in Canada. Methods: A negative binomial regression model was employed based on previously identified risk factors for liver cancer. Results: No association existed between the geographic distribution of liver cancer and surrogate markers of cyanobacterial contamination. As predicted, significant associations existed in areas with a high prevalence of hepatitis B virus infection, large immigrant populations and urban residences. Discussion and Conclusions: The results of this study suggest that cyanobacterial contamination of freshwater lakes does not play an important role in the increasing incidence of liver cancer in Canada.

A study of some political problems considering current geographical analytical parameters

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Héctor Adolfo Dupuy

2008-01-01

Full Text Available This paper intends to study some of the main problems presented, on different scales, by current politics, considering the spatial implications as well as various parameters offered lately by the geographical science. The proposal is supported by the theoretical bases developed from Emmanuel Wallerstein and Peter Taylor's statement about a world system structured as a world economy, based on the capitalist mode of production. Conversely, it attempts to provide a theoretical explanation for the dynamics experienced by the territories upon thee basis of such world system's mechanics. According to these assumptions, an analysis is proposed of some of the main phenomena resulting from the previous analysis and its spatial implications, such as the current power relations in the system, the subsistence of traditional power factors (Nation-states, ethnically based cultural configurations and the appearance of new ones (the forming of transnational blocs and associations, new social movements, new forms of local participation, the importance of hegemonic and counter-hegemonic discourses in the construction of symbolic representations and of the mass media in such processes or the new cultural identity and hybridization chart from population mobility.

Capacity of Physiotherapy Workforce Production in Thailand: Public-Private Mix, Secular Trend and Geographic Distribution.

Science.gov (United States)

Kaewsawang, Sarinee; Chongsuvivatwong, Virasakdi; Vongsirinavarat, Mantana

2016-06-01

In Thailand, the shortage of physiotherapists has been an increasing concern because of increased health burden from demographic and epidemiologic changes. This study aims to analyse the current situation of the physiotherapy workforce production system, secular trend, geographical distribution and comparison of public and private physiotherapy training institutes. Longitudinal data related to production capacity of the physiotherapy institutes were applied. Data from 2008 to 2012 were obtained from all 16 physiotherapy institutes in Thailand. Data during 2000-2007 were also retrieved from annual reports from the Ministry of Education. Descriptive statistics were initially used. Comparison was made between public and private physiotherapy institutes in terms of the number of students admitted and graduated, number of teachers, annual tuition fee, student-teacher ratio and dropout rate within 1 year. Predictive factors for graduation within 4 years were determined using logistic regression. In Thailand, there was an average of 800 physiotherapy graduates per year. New private institutes have been recently established and have steadily increased student admission rates. However, this has resulted in a high student-teacher ratio (median 7.1, inter-quartile range (IQR) 5.9-10.0). The first-year dropout rate in 2012 was 29.1%. Geographically, the majority of the institutes are clustered in the central region. Multivariate analysis revealed significantly lower probability of graduation within 4 years among students admitted to the private institutes and those in non-north-east region. The production capacity of the physiotherapy workforce is below an estimated need. Private physiotherapy institutes need more support to improve the situation of staff shortages and student graduation rates. The non-central regions should be encouraged to produce more physiotherapists. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Current Distributional Information on Freshwater Mussels (family Unionidae) in Mississippi National Forests

Science.gov (United States)

Wendell R. Haag; Melvin L. Warren

1995-01-01

Little is known about the distribution of freshwater mussels in Mississippi national forests. Review of the scant available information revealed that the national forests harbor a diverse mussel fauna of possibly 46 or more species (including confirmed, probable, and potential occurrences). Occurrence of 33 species is confirmed. Because of the geographic, physiographic...

Electric current distribution of a multiwall carbon nanotube

Energy Technology Data Exchange (ETDEWEB)

Chen, Li-Ying; Chang, Chia-Seng, E-mail: jasonc@phys.sinica.edu.tw [Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taiwan (China); Chen, Yu-Jyun [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China)

2016-07-15

The electric current distribution in a multiwall carbon nanotube (MWCNT) was studied by in situ measuring the electric potential along an individual MWCNT in the ultra-high vacuum transmission electron microscope (TEM). The current induced voltage drop along each section of a side-bonded MWCNT was measured by a potentiometric probe in TEM. We have quantitatively derived that the current on the outermost shell depends on the applied current and the shell diameter. More proportion of the total electronic carriers hop into the inner shells when the applied current is increased. The larger a MWCNT’s diameter is, the easier the electronic carriers can hop into the inner shells. We observed that, for an 8 nm MWCNT with 10 μA current applied, 99% of the total current was distributed on the outer two shells.

Geographical data structures supporting regional analysis

International Nuclear Information System (INIS)

Edwards, R.G.; Durfee, R.C.

1978-01-01

In recent years the computer has become a valuable aid in solving regional environmental problems. Over a hundred different geographic information systems have been developed to digitize, store, analyze, and display spatially distributed data. One important aspect of these systems is the data structure (e.g. grids, polygons, segments) used to model the environment being studied. This paper presents eight common geographic data structures and their use in studies of coal resources, power plant siting, population distributions, LANDSAT imagery analysis, and landuse analysis

Geographical distribution of β-globin gene mutations in Syria.

Science.gov (United States)

Murad, Hossam; Moasses, Faten; Dabboul, Amir; Mukhalalaty, Yasser; Bakoor, Ahmad Omar; Al-Achkar, Walid; Jarjour, Rami A

2018-04-11

Objectives β-Thalassemia disease is caused by mutations in the β-globin gene. This is considered as one of the common genetic disorders in Syria. The aim of this study was to identify the geographical distribution of the β-thalassemia mutations in Syria. Methods β-Globin gene mutations were characterized in 636 affected patients and 94 unrelated carriers using the amplification refractory mutations system-polymerase chain reaction technique and DNA sequencing. Results The study has revealed the presence of 38 β-globin gene mutations responsible for β-thalassemia in Syria. Important differences in regional distribution were observed. IVS-I.110 [G > A] (22.2%), IVS-I.1 [G > A] (17.8%), Cd 39 [C > T] (8.2%), IVS-II.1 [G > A] (7.6%), IVS-I.6 [T > C] (7.1%), Cd 8 [-AA] (6%), Cd 5 [-CT] (5.6%) and IVS-I.5 [G > C] (4.1%) were the eight predominant mutations found in our study. The coastal region had higher relative frequencies (37.9 and 22%) than other regions. A clear drift in the distribution of the third common Cd 39 [C > T] mutation in the northeast region (34.8%) to the northwest region (2.5%) was noted, while the IVS-I.5 [G > C] mutation has the highest prevalence in north regions. The IVS-I.6 [T > C] mutation had a distinct frequency in the middle region. Ten mutations -86 [C > G], -31 [A > G], -29 [A > G], 5'UTR; +22 [G > A], CAP + 1 [A > C], Codon 5/6 [-TG], IVS-I (-3) or codon 29 [C > T], IVS-I.2 [T > A], IVS-I.128 [T > G] and IVS-II.705 [T > G] were found in Syria for the first time. Conclusions These data will significantly facilitate the population screening, genetic counseling and prenatal diagnosis in Syrian population.

Geographic distance and ecosystem size determine the distribution of smallest protists in lacustrine ecosystems.

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Lepère, Cécile; Domaizon, Isabelle; Taïb, Najwa; Mangot, Jean-François; Bronner, Gisèle; Boucher, Delphine; Debroas, Didier

2013-07-01

Understanding the spatial distribution of aquatic microbial diversity and the underlying mechanisms causing differences in community composition is a challenging and central goal for ecologists. Recent insights into protistan diversity and ecology are increasing the debate over their spatial distribution. In this study, we investigate the importance of spatial and environmental factors in shaping the small protists community structure in lakes. We analyzed small protists community composition (beta-diversity) and richness (alpha-diversity) at regional scale by different molecular methods targeting the gene coding for 18S rRNA gene (T-RFLP and 454 pyrosequencing). Our results show a distance-decay pattern for rare and dominant taxa and the spatial distribution of the latter followed the prediction of the island biogeography theory. Furthermore, geographic distances between lakes seem to be the main force shaping the protists community composition in the lakes studied here. Finally, the spatial distribution of protists was discussed at the global scale (11 worldwide distributed lakes) by comparing these results with those present in the public database. UniFrac analysis showed 18S rRNA gene OTUs compositions significantly different among most of lakes, and this difference does not seem to be related to the trophic status. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration

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Vítor Jorge MB

2009-09-01

Full Text Available Abstract Background Helicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases. Results Independence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa. Conclusion This study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.

Geographical distribution of salmonella infected pig, cattle and sheep herds in Sweden 1993-2010

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Skog Lars

2011-10-01

Full Text Available Abstract Background The Swedish salmonella control programme covers the entire production chain, from feed to food. All salmonella serotypes are notifiable. On average, less than 20 cases of salmonella in food-producing animals are reported every year. In some situations, the cases would be expected to cluster geographically. The aim of this study was to illustrate the geographic distribution of the salmonella cases detected in pigs, cattle and sheep. Methods Data on all herds with pigs, cattle and sheep found to be infected with salmonella during the time period from 1993 to 2010 were obtained from the Swedish Board of Agriculture. Using the ArcGIS software, various maps were produced of infected herds, stratified on animal species as well as salmonella serotype. Based on ocular inspection of all maps, some were collapsed and some used separately. Data were also examined for temporal trends. Results No geographical clustering was observed for ovine or porcine cases. Cattle herds infected with Salmonella Dublin were mainly located in the southeast region and cattle herds infected with Salmonella Typhimurium in the most southern part of the country. Some seasonal variation was seen in cattle, but available data was not sufficient for further analyses. Conclusions Analyses of data on salmonella infected herds revealed some spatial and temporal patterns for salmonella in cattle. However, despite using 18 years' of data, the number of infected herds was too low for any useful statistical analyses.

Geographical information system analysis for oceanographic parameters in the coastal waters of Goa, India - A case study

Digital Repository Service at National Institute of Oceanography (India)

Suryanarayana, A.; Joglekar, V.V.

A geographical information system (GIS) is used to create oceanography database and to do the spatial analysis of physical, chemical and biological characteristics of the coastal waters of Goa, India. Vector maps depicting distributions of currents...

Positive identity entry control system with geographically distributed portals and enrollment stations

International Nuclear Information System (INIS)

McIntire, J.M.

1985-01-01

A positive identity entry control system using distributed processing to allow reliable geographically separated portals and enrollment stations has been installed and is fully operational at a large area DOE site. Identity verification requires a credential, a memorized number and measurement of a physical characteristic of the user. Additionally, all portal activity is monitored by guards. The portal system is dual redundant such that no single point failure will shut down operations. Each portal site maintains its own subset of the master data base so off-site failure of the central data base manager or its communication links will not significantly affect local portal activity. The system is suitable for installations with large populations requiring access control at several remote sites scattered over a large area

An Ambient Intelligence Framework for the Provision of Geographically Distributed Multimedia Content to Mobility Impaired Users

Science.gov (United States)

Kehagias, Dionysios D.; Giakoumis, Dimitris; Tzovaras, Dimitrios; Bekiaris, Evangelos; Wiethoff, Marion

This chapter presents an ambient intelligence framework whose goal is to facilitate the information needs of mobility impaired users on the move. This framework couples users with geographically distributed services and the corresponding multimedia content, enabling access to context-sensitive information based on user geographic location and the use case under consideration. It provides a multi-modal facility that is realized through a set of mobile devices and user interfaces that address the needs of ten different types of user impairments. The overall ambient intelligence framework enables users who are equipped with mobile devices to access multimedia content in order to undertake activities relevant to one or more of the following domains: transportation, tourism and leisure, personal support services, work, business, education, social relations and community building. User experience is being explored against those activities through a specific usage scenario.

Prevalence and geographic distribution of herniated intervertebral disc in Korean 19-year-old male from 2008 to 2009: a study based on Korean conscription -national and geographic prevalence of herniated intervertebral disc in Korean 19YO male-.

Science.gov (United States)

Lee, Sang Hun; Oh, Chang Hyun; Yoon, Seung Hwan; Park, Hyeong-chun; Park, Chong Oon

2013-09-01

This study was to determine the prevalence of herniated intervertebral disc (HIVD) among Korean 19-year-old male in a large national sample and to compare the prevalence across geographic regions based on the data of conscription. We analyzed the conscription data of 615508 cases who were 19-year-old male, given an examination for conscription at nationwide Korean Military Manpower Administration from January 2008 to December 2009. Prevalence was determined by dividing the number of cases by the number of persons enrolled for 2 years. The analyses included of a cross-tabulations and nonparametric chi-square to compare the prevalence according to geographic region, disc severity, and conscription year. The prevalence of HIVD among 19-year-old male was 0.47%. Seoul had the highest prevalence of HIVD (total HIVD was 0.60%, and severe HIVD was 0.44%). The prevalence of HIVD was lower in Jeollabuk- do and Jeollanam-do (total HIVD was 0.25-0.27%, and severe HIVD was 0.16-0.17%). Annual prevalence of HIVD was slightly decreased in 2009, but geographic distribution annually was not different. In Korean 19-year-old male, the national prevalence of adolescent HIVD was 0.60%, but different geographic distribution was observed. It is quite possible that secondary contributing factor(s) interfere with the different geographic prevalence of HIVD.

Modeling the geographic distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the contiguous United States

Science.gov (United States)

Hahn, Micah; Jarnevich, Catherine S.; Monaghan, Andrew J.; Eisen, Rebecca J.

2016-01-01

In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi ) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

The Current Status of the Distribution Range of the Western Pine Beetle, Dendroctonus brevicomis (Curculionidae: Solytinae) in Northern Mexico.

Science.gov (United States)

Valerio-Mendoza, O; Armendáriz-Toledano, F; Cuéllar-Rodríguez, G; Negrón, José F; Zúñiga, G

2017-09-01

The distribution range of the western pine beetle Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae) is supported only by scattered records in the northern parts of Mexico, suggesting that its populations may be marginal and rare in this region. In this study, we review the geographical distribution of D. brevicomis in northern Mexico and perform a geometric morphometric analysis of seminal rod shape to evaluate its reliability for identifying this species with respect to other members of the Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae) complex. Our results provide 30 new records, with 26 distributed in the Sierra Madre Occidental and 4 in the Sierra Madre Oriental. These records extend the known distribution range of D. brevicomis to Durango and Tamaulipas states in northern Mexico. Furthermore, we find high geographic variation in size and shape of the seminal rod, with conspicous differences among individuals from different geographical regions, namely west and east of the Great Basin and between mountain systems in Mexico. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Efficient workload management in geographically distributed data centers leveraging autoregressive models

Science.gov (United States)

Altomare, Albino; Cesario, Eugenio; Mastroianni, Carlo

2016-10-01

The opportunity of using Cloud resources on a pay-as-you-go basis and the availability of powerful data centers and high bandwidth connections are speeding up the success and popularity of Cloud systems, which is making on-demand computing a common practice for enterprises and scientific communities. The reasons for this success include natural business distribution, the need for high availability and disaster tolerance, the sheer size of their computational infrastructure, and/or the desire to provide uniform access times to the infrastructure from widely distributed client sites. Nevertheless, the expansion of large data centers is resulting in a huge rise of electrical power consumed by hardware facilities and cooling systems. The geographical distribution of data centers is becoming an opportunity: the variability of electricity prices, environmental conditions and client requests, both from site to site and with time, makes it possible to intelligently and dynamically (re)distribute the computational workload and achieve as diverse business goals as: the reduction of costs, energy consumption and carbon emissions, the satisfaction of performance constraints, the adherence to Service Level Agreement established with users, etc. This paper proposes an approach that helps to achieve the business goals established by the data center administrators. The workload distribution is driven by a fitness function, evaluated for each data center, which weighs some key parameters related to business objectives, among which, the price of electricity, the carbon emission rate, the balance of load among the data centers etc. For example, the energy costs can be reduced by using a "follow the moon" approach, e.g. by migrating the workload to data centers where the price of electricity is lower at that time. Our approach uses data about historical usage of the data centers and data about environmental conditions to predict, with the help of regressive models, the values of the

The spatial distribution of known predictors of autism spectrum disorders impacts geographic variability in prevalence in central North Carolina

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Hoffman Kate

2012-10-01

Full Text Available Abstract Background The causes of autism spectrum disorders (ASD remain largely unknown and widely debated; however, evidence increasingly points to the importance of environmental exposures. A growing number of studies use geographic variability in ASD prevalence or exposure patterns to investigate the association between environmental factors and ASD. However, differences in the geographic distribution of established risk and predictive factors for ASD, such as maternal education or age, can interfere with investigations of ASD etiology. We evaluated geographic variability in the prevalence of ASD in central North Carolina and the impact of spatial confounding by known risk and predictive factors. Methods Children meeting a standardized case definition for ASD at 8 years of age were identified through records-based surveillance for 8 counties biennially from 2002 to 2008 (n=532. Vital records were used to identify the underlying cohort (15% random sample of children born in the same years as children with an ASD, n=11,034, and to obtain birth addresses. We used generalized additive models (GAMs to estimate the prevalence of ASD across the region by smoothing latitude and longitude. GAMs, unlike methods used in previous spatial analyses of ASD, allow for extensive adjustment of individual-level risk factors (e.g. maternal age and education when evaluating spatial variability of disease prevalence. Results Unadjusted maps revealed geographic variation in surveillance-recognized ASD. Children born in certain regions of the study area were up to 1.27 times as likely to be recognized as having ASD compared to children born in the study area as a whole (prevalence ratio (PR range across the study area 0.57-1.27; global P=0.003. However, geographic gradients of ASD prevalence were attenuated after adjusting for spatial confounders (adjusted PR range 0.72-1.12 across the study area; global P=0.052. Conclusions In these data, spatial variation of ASD

About the Geographic Distribution of Economic Science in Asian Russia

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Alexander Nikolaevich Demyanenko

2014-12-01

Full Text Available The article presents the results of empirical studies of modern geographic distribution of economic science in Asian Russia (i. e. three macro-regions of Russia: Far East, Siberia and the Urals Region. The study is based on an original database of articles on Economics and related disciplines which arearranged within the Elibrary platformfor 2005-2013. These articles arewritten by fellows of research organizations that are located in the Asian part of Russia.Statistical analysis of the main indicators of publication activity shows that there are significant differences in the scope, dynamics, and quality of the results of this activity among the research organizations of various types.The authors focused on the territorial structure of the study of the economy defined as a set of scientific centers of varying scale and type, as well as networks of scientific communication.It is revealed that publication activity of economic research institutions in Asian Russia has a high level of spatial concentration and the system of scientific communication, formed by the scientific journals of the region, has a high level of fragmentation

Geographical cost-supply analysis forest biomass for distributed generation in Denmark

DEFF Research Database (Denmark)

Möller, Bernd

2004-01-01

The article presents a study which uses geographical information system (GIS) to perform cost-supply analysis of wood chips resources for energy production.......The article presents a study which uses geographical information system (GIS) to perform cost-supply analysis of wood chips resources for energy production....

Geographic Distribution of Radiologists and Utilization of Teleradiology in Japan: A Longitudinal Analysis Based on National Census Data.

Science.gov (United States)

Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

2015-01-01

Japan has the most CT and MRI scanners per unit population in the world, and as these technologies spread, their geographic distribution is becoming equalized. In contrast, the number of radiologists per unit population in Japan is the lowest among OECD countries and their geographic distribution is unknown. Likewise, little is known about the use of teleradiology, which can compensate for the uneven distribution of radiologists. Based on the Survey of Physicians, Dentists and Pharmacists and the Static Survey of Medical Institutions by the Ministry of Health, Labour and Welfare, a dataset of radiologists and CT and MRI utilizations in each of Japan's 1811 municipalities was created. The inter-municipality equity of the number of radiologists was evaluated using Gini coefficient. Logistic regression analysis, based on Static Survey data, was performed to evaluate the association between hospital location and teleradiology use. Between 2006 and 2012 the number of radiologists increased by 21.7%, but the Gini coefficient remained unchanged. The number of radiologists per 1,000 CT (MRI) utilizations decreased by 17.9% (1.0%); the number was highest in metropolis and lowest in town/village and the disparity has widened from 1.9 to 2.2 (1.6 to 2.0) times. The number of hospitals and clinics using teleradiology has increased (by 69.6% and 18.1%, respectively). Hospitals located in towns/villages (odds ratio 1.61; 95% confidence interval 1.26-2.07) were more likely to use teleradiology than those in metropolises. Contrary to the CT and MRI distributions, radiologist distribution has not been evened out by the increase in their number; in other words, the distribution of radiologists was not affected by market-derived spatial competition force. As a consequence, the gap of the radiologist shortage between urban and rural areas is increasing. Teleradiology, which is one way to ameliorate this gap, should be encouraged.

Geographic distribution of ebony leaf monkey Trachypithecus auratus (E. Geoffroy Saint-Hilaire, 1812) (Mammalia: Primates: Cercopithecidae)

OpenAIRE

Nijman, Vincent

2000-01-01

As one of the fundamental units of ecology and biogeography, the geographic distribution of the endemic and threatened ebony leaf monkey Trachypithecus auratus (E. Geoffroy Saint-Hilaire, 1812) on the islands of Java, Bali, and Lombok (Indonesia) has been assessed. All localities where the species has been collected are listed, and forty-two areas (each in itself consisting of numerous smaller sites) where the species has been recorded are discussed. The species occurs in a large variety of f...

Geographical Distribution of the Most Frequent Mutations of Familial Mediterranean fever in the World

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Soraya Hadi

2016-09-01

Full Text Available Background and objectives: Familial Mediterranean Fever (FMF is an autosomal recessive disease. Generally, the Mediterranean basin is the region where the first cases of FMF have been identified. The gene responsible for FMF is gene MEFV. Disease occurs due to mutations in the gene MEFV. Our aim was to determine the geographical distribution of the most frequent mutations in Familial Mediterranean Fever Disease in the world. Material and Methods: In this study, databases including Google Scholar, PubMed, Medline, Ovid, IranMedex, Irandoc, SID, Magiran and published papers were searched with no limitation in time. Then, all collected studies without any limitation were assessed to determine relevant studies. At the end, world map of the most frequent mutations of FMF was generated by Geographical Information System (GIS software. Results: Although more than 290 mutations of the MEFV gene have been described, only four mutations (M694V, M694I, V726A, and E148Q were prevalent among patients with FMF. Conclusion: The most frequent mutation associated with FMF mutation is M694V all over the world. E148Q mutation was found to be with mild clinical relevance.

Predicting the geographic distribution of Lutzomyia longipalpis (Diptera: Psychodidae) and visceral leishmaniasis in the state of Mato Grosso do Sul, Brazil.

Science.gov (United States)

Almeida, Paulo Silva de; Sciamarelli, Alan; Batista, Paulo Mira; Ferreira, Ademar Dimas; Nascimento, João; Raizer, Josué; Andrade Filho, José Dilermando; Gurgel-Gonçalves, Rodrigo

2013-12-01

To understand the geographic distribution of visceral leishmaniasis (VL) in the state of Mato Grosso do Sul (MS), Brazil, both the climatic niches of Lutzomyia longipalpis and VL cases were analysed. Distributional data were obtained from 55 of the 79 counties of MS between 2003-2012. Ecological niche models (ENM) of Lu. longipalpis and VL cases were produced using the maximum entropy algorithm based on eight climatic variables. Lu. longipalpis showed a wide distribution in MS. The highest climatic suitability for Lu. longipalpis was observed in southern MS. Temperature seasonality and annual mean precipitation were the variables that most influenced these models. Two areas of high climatic suitability for the occurrence of VL cases were predicted: one near Aquidauana and another encompassing several municipalities in the southeast region of MS. As expected, a large overlap between the models for Lu. longipalpis and VL cases was detected. Northern and northwestern areas of MS were suitable for the occurrence of cases, but did not show high climatic suitability for Lu. longipalpis. ENM of vectors and human cases provided a greater understanding of the geographic distribution of VL in MS, which can be applied to the development of future surveillance strategies.

Vascular plants of the Nevada Test Site and Central-Southern Nevada: ecologic and geographic distributions

Energy Technology Data Exchange (ETDEWEB)

Beatley, J.C.

1976-01-01

The physical environment of the Nevada Test Site and surrounding area is described with regard to physiography, geology, soils, and climate. A discussion of plant associations is given for the Mojave Desert, Transition Desert, and Great Basin Desert. The vegetation of disturbed sites is discussed with regard to introduced species as well as endangered and threatened species. Collections of vascular plants were made during 1959 to 1975. The plants, belonging to 1093 taxa and 98 families are listed together with information concerning ecologic and geographic distributions. Indexes to families, genera, and species are included. (HLW)

Geographic Distribution of Chagas Disease Vectors in Brazil Based on Ecological Niche Modeling

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Rodrigo Gurgel-Gonçalves

2012-01-01

Full Text Available Although Brazil was declared free from Chagas disease transmission by the domestic vector Triatoma infestans, human acute cases are still being registered based on transmission by native triatomine species. For a better understanding of transmission risk, the geographic distribution of Brazilian triatomines was analyzed. Sixteen out of 62 Brazilian species that both occur in >20 municipalities and present synanthropic tendencies were modeled based on their ecological niches. Panstrongylus geniculatus and P. megistus showed broad ecological ranges, but most of the species sort out by the biome in which they are distributed: Rhodnius pictipes and R. robustus in the Amazon; R. neglectus, Triatoma sordida, and T. costalimai in the Cerrado; R. nasutus, P. lutzi, T. brasiliensis, T. pseudomaculata, T. melanocephala, and T. petrocchiae in the Caatinga; T. rubrovaria in the southern pampas; T. tibiamaculata and T. vitticeps in the Atlantic Forest. Although most occurrences were recorded in open areas (Cerrado and Caatinga, our results show that all environmental conditions in the country are favorable to one or more of the species analyzed, such that almost nowhere is Chagas transmission risk negligible.

Energy gradients and the geographic distribution of local ant diversity.

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Kaspari, Michael; Ward, Philip S; Yuan, May

2004-08-01

Geographical diversity gradients, even among local communities, can ultimately arise from geographical differences in speciation and extinction rates. We evaluated three models--energy-speciation, energy-abundance, and area--that predict how geographic trends in net diversification rates generate trends in diversity. We sampled 96 litter ant communities from four provinces: Australia, Madagascar, North America, and South America. The energy-speciation hypothesis best predicted ant species richness by accurately predicting the slope of the temperature diversity curve, and accounting for most of the variation in diversity. The communities showed a strong latitudinal gradient in species richness as well as inter-province differences in diversity. The former vanished in the temperature-diversity residuals, suggesting that the latitudinal gradient arises primarily from higher diversification rates in the tropics. However, inter-province differences in diversity persisted in those residuals--South American communities remained more diverse than those in North America and Australia even after the effects of temperature were removed.

Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

International Nuclear Information System (INIS)

Rush, Scott A.; Borga, Katrine; Dietz, Rune; Born, Erik W.; Sonne, Christian; Evans, Thomas; Muir, Derek C.G.; Letcher, Robert J.; Norstrom, Ross J.; Fisk, Aaron T.

2008-01-01

To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984. Concentrations of most elements in the polar bears did not exceed toxicity thresholds, although Cd and Hg exceeded levels correlated with the formation of hepatic lesions in laboratory animals. - Geographical trends were observed for a number of elements in livers, including mercury, of polar bears collected across Alaska, Canada and Greenland and were similar to those observed in the early 1980s

Comparison of Measured Dark Current Distributions with Calculated Damage Energy Distributions in HgCdTe

Science.gov (United States)

Marshall, C. J.; Marshall, P. W.; Howe, C. L.; Reed, R. A.; Weller, R. A.; Mendenhall, M.; Waczynski, A.; Ladbury, R.; Jordan, T. M.

2007-01-01

This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [1]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using MRED [3-5], a Geant4 [4,6] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

Geography of current and future global mammal extinction risk.

Directory of Open Access Journals (Sweden)

Ana D Davidson

Full Text Available Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species' trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial

Geography of current and future global mammal extinction risk.

Science.gov (United States)

Davidson, Ana D; Shoemaker, Kevin T; Weinstein, Ben; Costa, Gabriel C; Brooks, Thomas M; Ceballos, Gerardo; Radeloff, Volker C; Rondinini, Carlo; Graham, Catherine H

2017-01-01

Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species' trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial variation in the

GEOGRAPHIC NAMES INFORMATION SYSTEM (GNIS) ...

Science.gov (United States)

The Geographic Names Information System (GNIS), developed by the U.S. Geological Survey in cooperation with the U.S. Board on Geographic Names (BGN), contains information about physical and cultural geographic features in the United States and associated areas, both current and historical, but not including roads and highways. The database also contains geographic names in Antarctica. The database holds the Federally recognized name of each feature and defines the location of the feature by state, county, USGS topographic map, and geographic coordinates. Other feature attributes include names or spellings other than the official name, feature designations, feature class, historical and descriptive information, and for some categories of features the geometric boundaries. The database assigns a unique feature identifier, a random number, that is a key for accessing, integrating, or reconciling GNIS data with other data sets. The GNIS is our Nation's official repository of domestic geographic feature names information.

Soil Survey Geographic (SSURGO) - Kinds and Distribution of Soils

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California Natural Resource Agency — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

Climate change effects on the geographic distribution of specialist tree species of the Brazilian tropical dry forests.

Science.gov (United States)

Rodrigues, P M S; Silva, J O; Eisenlohr, P V; Schaefer, C E G R

2015-08-01

The aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenanthera colubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant's adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly.

Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

KAUST Repository

Yukawa, Satoshi

2009-02-15

A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

KAUST Repository

Yukawa, Satoshi; Shimada, Takashi; Ogushi, Fumiko; Ito, Nobuyasu

2009-01-01

A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

Geographical patterns in cyanobacteria distribution: climate influence at regional scale.

Science.gov (United States)

Pitois, Frédéric; Thoraval, Isabelle; Baurès, Estelle; Thomas, Olivier

2014-01-28

Cyanobacteria are a component of public health hazards in freshwater environments because of their potential as toxin producers. Eutrophication has long been considered the main cause of cyanobacteria outbreak and proliferation, whereas many studies emphasized the effect of abiotic parameters (mainly temperature and light) on cell growth rate or toxin production. In view of the growing concerns of global change consequences on public health parameters, this study attempts to enlighten climate influence on cyanobacteria at regional scale in Brittany (NW France). The results show that homogeneous cyanobacteria groups are associated with climatic domains related to temperature, global radiation and pluviometry, whereas microcystins (MCs) occurrences are only correlated to local cyanobacteria species composition. As the regional climatic gradient amplitude is similar to the projected climate evolution on a 30-year timespan, a comparison between the present NW and SE situations was used to extrapolate the evolution of geographical cyanobacteria distribution in Brittany. Cyanobacteria composition should shift toward species associated with more frequent Microcystins occurrences along a NW/SE axis whereas lakes situated along a SW/NE axis should transition to species (mainly Nostocales) associated with lower MCs detection frequencies.

Geographic distribution and taxonomic circumscription of populations within Coryphantha section Robustispina (Cactaceae).

Science.gov (United States)

Baker, Marc A; Butterworth, Charles A

2013-05-01

Taxonomic circumscription of subspecific taxa within Coryphantha robustispina was evaluated with morphological data and microsatellites. This study was the first to compare adequately sampled morphological and DNA analyses at the population level in the Cactaceae. This comparison was important to test reliability of both methods and to gain a better understanding of phytogeography, evolution, and systematics of the species, knowledge that could prove useful for other taxa as well. Populations of C. robustispina subsp. robustispina are listed as endangered by the U. S. Fish and Wildlife Service. Our primary goal was to explore correlations among geographical distribution, morphology, and genetics of selected populations throughout the range of the species and the outgroup, C. poselgeriana. • Stem characters were measured for 638 individuals among 16 populations. Flower characters were measured for 180 individuals among 12 populations. Ten microsatellite DNA loci were isolated and characterized for 204 individuals among 13 populations. Data were analyzed using various multivariate analyses. • Our results indicated that, within Coryphantha robustispina, there were three morphologically, genetically, and geographically coherent groups represented by the names C. robustispina subsp. robustispina, C. robustispina subsp. uncinata, and C. robustispina subsp. scheeri. For most analyses, distinctions among the three groups were primarily not as great as those between any one of them and the outgroup. • Results suggested that the three subspecific taxa within Coryphantha robustispina are good subspecies but should not be elevated to species rank. The closely aligned results between morphology and microsatellite data support the design and utility of both methods.

Could natural selection change the geographic range limits of light brown apple moth (Lepidoptera, Tortricidae) in North America?

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Amy C. Morey; Robert C. Venette; William D. Hutchison

2013-01-01

We artificially selected for increased freeze tolerance in the invasive light brown apple moth. Our results suggest that, by not accounting for adaptation to cold, current models of potential geographic distributions could underestimate the areas at risk of exposure to this species.

Geographic Analysis of the Radiation Oncology Workforce

Energy Technology Data Exchange (ETDEWEB)

Aneja, Sanjay [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Cancer Outcomes, Policy, and Effectiveness Research Center at Yale, New Haven, CT (United States); Smith, Benjamin D. [University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Gross, Cary P. [Cancer Outcomes, Policy, and Effectiveness Research Center at Yale, New Haven, CT (United States); Department of General Internal Medicine, Yale University School of Medicine, New Haven, CT (United States); Wilson, Lynn D. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Haffty, Bruce G. [Cancer Institute of New Jersey, New Brunswick, NJ (United States); Roberts, Kenneth [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Yu, James B., E-mail: james.b.yu@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Cancer Outcomes, Policy, and Effectiveness Research Center at Yale, New Haven, CT (United States)

2012-04-01

Purpose: To evaluate trends in the geographic distribution of the radiation oncology (RO) workforce. Methods and Materials: We used the 1995 and 2007 versions of the Area Resource File to map the ratio of RO to the population aged 65 years or older (ROR) within different health service areas (HSA) within the United States. We used regression analysis to find associations between population variables and 2007 ROR. We calculated Gini coefficients for ROR to assess the evenness of RO distribution and compared that with primary care physicians and total physicians. Results: There was a 24% increase in the RO workforce from 1995 to 2007. The overall growth in the RO workforce was less than that of primary care or the overall physician workforce. The mean ROR among HSAs increased by more than one radiation oncologist per 100,000 people aged 65 years or older, from 5.08 per 100,000 to 6.16 per 100,000. However, there remained consistent geographic variability concerning RO distribution, specifically affecting the non-metropolitan HSAs. Regression analysis found higher ROR in HSAs that possessed higher education (p = 0.001), higher income (p < 0.001), lower unemployment rates (p < 0.001), and higher minority population (p = 0.022). Gini coefficients showed RO distribution less even than for both primary care physicians and total physicians (0.326 compared with 0.196 and 0.292, respectively). Conclusions: Despite a modest growth in the RO workforce, there exists persistent geographic maldistribution of radiation oncologists allocated along socioeconomic and racial lines. To solve problems surrounding the RO workforce, issues concerning both gross numbers and geographic distribution must be addressed.

Geographic Analysis of the Radiation Oncology Workforce

International Nuclear Information System (INIS)

Aneja, Sanjay; Smith, Benjamin D.; Gross, Cary P.; Wilson, Lynn D.; Haffty, Bruce G.; Roberts, Kenneth; Yu, James B.

2012-01-01

Purpose: To evaluate trends in the geographic distribution of the radiation oncology (RO) workforce. Methods and Materials: We used the 1995 and 2007 versions of the Area Resource File to map the ratio of RO to the population aged 65 years or older (ROR) within different health service areas (HSA) within the United States. We used regression analysis to find associations between population variables and 2007 ROR. We calculated Gini coefficients for ROR to assess the evenness of RO distribution and compared that with primary care physicians and total physicians. Results: There was a 24% increase in the RO workforce from 1995 to 2007. The overall growth in the RO workforce was less than that of primary care or the overall physician workforce. The mean ROR among HSAs increased by more than one radiation oncologist per 100,000 people aged 65 years or older, from 5.08 per 100,000 to 6.16 per 100,000. However, there remained consistent geographic variability concerning RO distribution, specifically affecting the non-metropolitan HSAs. Regression analysis found higher ROR in HSAs that possessed higher education (p = 0.001), higher income (p < 0.001), lower unemployment rates (p < 0.001), and higher minority population (p = 0.022). Gini coefficients showed RO distribution less even than for both primary care physicians and total physicians (0.326 compared with 0.196 and 0.292, respectively). Conclusions: Despite a modest growth in the RO workforce, there exists persistent geographic maldistribution of radiation oncologists allocated along socioeconomic and racial lines. To solve problems surrounding the RO workforce, issues concerning both gross numbers and geographic distribution must be addressed.

Molecular insight into systematics, host associations, life cycles and geographic distribution of the nematode family Rhabdiasidae.

Science.gov (United States)

Tkach, Vasyl V; Kuzmin, Yuriy; Snyder, Scott D

2014-04-01

Rhabdiasidae Railliet, 1915 is a globally distributed group of up to 100 known species of nematodes parasitic in amphibians and reptiles. This work presents the results of a molecular phylogenetic analysis of 36 species of Rhabdiasidae from reptiles and amphibians from six continents. New DNA sequences encompassing partial 18S rDNA, ITS1, 5.8S rDNA, ITS2 and partial 28S rDNA regions of nuclear ribosomal DNA were obtained from 27 species and pre-existing sequences for nine species were incorporated. The broad taxonomic, host and geographical coverage of the specimens allowed us to address long-standing questions in rhabdiasid systematics, evolution, geographic distribution, and patterns of host association. Our analysis demonstrated that rhabdiasids parasitic in snakes are an independent genus sister to the rest of the Rhabdiasidae, a status supported by life cycle data. Based on the combined evidence of molecular phylogeny, morphology and life cycle characteristics, a new genus Serpentirhabdias gen. nov. with the type species Serpentirhabdias elaphe (Sharpilo, 1976) comb. nov. is established. The phylogeny supports the monophyly of Entomelas Travassos, 1930, Pneumonema Johnston, 1916 and the largest genus of the family, Rhabdias Stiles and Hassall, 1905. DNA sequence comparisons demonstrate the presence of more than one species in the previously monotypic Pneumonema from Australian scincid lizards. The distribution of some morphological characters in the genus Rhabdias shows little consistency within the phylogenetic tree topology, in particular the apical structures widely used in rhabdiasid systematics. Our data suggest that some of the characters, while valuable for species differentiation, are not appropriate for differentiation among higher taxa and are of limited phylogenetic utility. Rhabdias is the only genus with a cosmopolitan distribution, but some of the lineages within Rhabdias are distributed on a single continent or a group of adjacent

Using rare earth elements for the identification of the geographic origin of food

Science.gov (United States)

Meisel, T.; Bandoniene, D.; Joebstl, D.

2009-04-01

The European Union defined regimes within the Protected Geographical Status (PGS) framework to protect names of regional food specialities. Thus only food produced in a specific geographical area with a specific way of production or quality can be protected by a protected geographical indication (PGI) label. As such Styrian Pumpkin Seed Oil has been approved with this label, but as with many other high priced regional specialities, fraud cannot be excluded or nor identified. Thus the aim of this work is, to develop an analytical method for the control of the geographic origin of pumpkin seed oil and also to test the method for other protected products. The development of such a method is not only of interest for scientists, but also of importance for the consumer wanting to know the origin of the food products and the assurance of the purity and quality. The group of rare earth elements (REE) in plants also have a characteristic distribution pattern similar to upper crustal REE distributions. Since the REE concentrations are extremely low in pumpkin seed oil (ppt to low ppb), ICP-MS was the only sensitive tool able to produce validated results. The carrier of the REE are most likely small particles distributed within the pumpkin seed oil. Unlike, e.g., olive oil, pumpkin seed oil is bottled and sold unfiltered, which makes this Styrian speciality an interesting sampling target. As pumpkin seed oils from different geographic origin show variable trace element and rare earth distribution patterns, is should possible to trace the origin of these oils. In the current project pumpkin seeds from different regions in Austria and from abroad were sampled. The trace element patterns in the extracted oil of these seeds were determined and a preliminary classification with discriminate analysis was successfully done on a statistical basis. In addition to the study of the geographic origin it was demonstrated that REE distribution patterns can also be used for the

Effects of Abiotic Factors on the Geographic Distribution of Body Size Variation and Chromosomal Polymorphisms in Two Neotropical Grasshopper Species (Dichroplus: Melanoplinae: Acrididae

Directory of Open Access Journals (Sweden)

Claudio J. Bidau

2012-01-01

Full Text Available We review the effects of abiotic factors on body size in two grasshopper species with large geographical distributions: Dichroplus pratensis and D. vittatus, inhabiting Argentina in diverse natural habitats. Geographical spans for both species provide an opportunity to study the effects of changes in abiotic factors on body size. The analyses of body size distribution in both species revealed a converse Bergmannian pattern: body size is positively correlated with latitude, altitude, and seasonality that influences time available for development and growth. Allen’s rule is also inverted. Morphological variability increases towards the ends of the Bergmannian clines and, in D. pratensis, is related with a central-marginal distribution of chromosomal variants that influence recombination. The converse Bergmannian patterns influence sexual size dimorphism in both species but in different fashions. Body size variation at a microspatial scale in D. pratensis is extremely sensitive to microclimatic clines. We finally compare our results with those for other Orthopteran species.

[Prediction of potential geographic distribution of Lyme disease in Qinghai province with Maximum Entropy model].

Science.gov (United States)

Zhang, Lin; Hou, Xuexia; Liu, Huixin; Liu, Wei; Wan, Kanglin; Hao, Qin

2016-01-01

To predict the potential geographic distribution of Lyme disease in Qinghai by using Maximum Entropy model (MaxEnt). The sero-diagnosis data of Lyme disease in 6 counties (Huzhu, Zeku, Tongde, Datong, Qilian and Xunhua) and the environmental and anthropogenic data including altitude, human footprint, normalized difference vegetation index (NDVI) and temperature in Qinghai province since 1990 were collected. By using the data of Huzhu Zeku and Tongde, the prediction of potential distribution of Lyme disease in Qinghai was conducted with MaxEnt. The prediction results were compared with the human sero-prevalence of Lyme disease in Datong, Qilian and Xunhua counties in Qinghai. Three hot spots of Lyme disease were predicted in Qinghai, which were all in the east forest areas. Furthermore, the NDVI showed the most important role in the model prediction, followed by human footprint. Datong, Qilian and Xunhua counties were all in eastern Qinghai. Xunhua was in hot spot areaⅡ, Datong was close to the north of hot spot area Ⅲ, while Qilian with lowest sero-prevalence of Lyme disease was not in the hot spot areas. The data were well modeled in MaxEnt (Area Under Curve=0.980). The actual distribution of Lyme disease in Qinghai was in consistent with the results of the model prediction. MaxEnt could be used in predicting the potential distribution patterns of Lyme disease. The distribution of vegetation and the range and intensity of human activity might be related with Lyme disease distribution.

Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).

Science.gov (United States)

Martins, Thiago F; Barbieri, Amália R M; Costa, Francisco B; Terassini, Flávio A; Camargo, Luís M A; Peterka, Cássio R L; de C Pacheco, Richard; Dias, Ricardo A; Nunes, Pablo H; Marcili, Arlei; Scofield, Alessandra; Campos, Artur K; Horta, Mauricio C; Guilloux, Aline G A; Benatti, Hector R; Ramirez, Diego G; Barros-Battesti, Darci M; Labruna, Marcelo B

2016-03-31

Until recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known. The distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens. From the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum. Our results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some

Current and field distribution in high temperature superconductors

International Nuclear Information System (INIS)

Johnston, M.D.

1998-01-01

The manufacture of wires from HTS materials containing copper-oxide planes is difficult because their physical and electrical properties are highly anisotropic. The electrical connectivity depends on the nearest-neighbour grain alignment and although a high degree of grain texture is achieved through processing, the tape microstructure is generally far from uniform, with weak links and porosity also complicating the picture. In order to optimise the processing, the microstructural features common to good tapes must be identified, requiring knowledge of the local properties. The preferential path taken by transport current is determined by the properties of the local microstructure and as such can be used to measure the variation in quality across the tape cross-section. By measuring the self-field profile generated by a current-carrying tape, it is possible to extract the associated current distribution. I have designed and built a Scanning Hall Probe Microscope to measure the normal field distribution above superconductor tapes carrying DC currents, operating at liquid nitrogen temperature and zero applied magnetic field. It has a spatial resolution of 50*50 μm and a field sensitivity of 5 μT, and can scan over a distance of 6 mm. The current extraction is performed by means of a deconvolution procedure based on Legendre functions. This allows a nondestructive, non-invasive method of evaluating the effects of the processing on the tapes - especially when correlated with transport and magnetisation measurement data. Conductors fabricated from Bi 2 Sr 2 Ca 2 Cu 3 O 10 , Bi 2 Sr 2 CaCu 2 O 8 and (Tl 0.78 Bi 0.22 )(Sr 0.8 Ba 0.2 ) 2 Ca 2 Cu 3 O x , have been investigated. I have confirmed the reports that in Bi-2223/Ag mono-core conductors produced by the oxide-powder-in-tube (OPIT) technique, the current flows predominantly at the edges of the tape, where the grains are long and well-aligned. This is in contrast to Bi-2212 ribbons, where the better microstructure

Mapping and Modelling the Geographical Distribution and Environmental Limits of Podoconiosis in Ethiopia.

Science.gov (United States)

Deribe, Kebede; Cano, Jorge; Newport, Melanie J; Golding, Nick; Pullan, Rachel L; Sime, Heven; Gebretsadik, Abeba; Assefa, Ashenafi; Kebede, Amha; Hailu, Asrat; Rebollo, Maria P; Shafi, Oumer; Bockarie, Moses J; Aseffa, Abraham; Hay, Simon I; Reithinger, Richard; Enquselassie, Fikre; Davey, Gail; Brooker, Simon J

2015-01-01

Ethiopia is assumed to have the highest burden of podoconiosis globally, but the geographical distribution and environmental limits and correlates are yet to be fully investigated. In this paper we use data from a nationwide survey to address these issues. Our analyses are based on data arising from the integrated mapping of podoconiosis and lymphatic filariasis (LF) conducted in 2013, supplemented by data from an earlier mapping of LF in western Ethiopia in 2008-2010. The integrated mapping used woreda (district) health offices' reports of podoconiosis and LF to guide selection of survey sites. A suite of environmental and climatic data and boosted regression tree (BRT) modelling was used to investigate environmental limits and predict the probability of podoconiosis occurrence. Data were available for 141,238 individuals from 1,442 communities in 775 districts from all nine regional states and two city administrations of Ethiopia. In 41.9% of surveyed districts no cases of podoconiosis were identified, with all districts in Affar, Dire Dawa, Somali and Gambella regional states lacking the disease. The disease was most common, with lymphoedema positivity rate exceeding 5%, in the central highlands of Ethiopia, in Amhara, Oromia and Southern Nations, Nationalities and Peoples regional states. BRT modelling indicated that the probability of podoconiosis occurrence increased with increasing altitude, precipitation and silt fraction of soil and decreased with population density and clay content. Based on the BRT model, we estimate that in 2010, 34.9 (95% confidence interval [CI]: 20.2-51.7) million people (i.e. 43.8%; 95% CI: 25.3-64.8% of Ethiopia's national population) lived in areas environmentally suitable for the occurrence of podoconiosis. Podoconiosis is more widespread in Ethiopia than previously estimated, but occurs in distinct geographical regions that are tied to identifiable environmental factors. The resultant maps can be used to guide programme planning

Mapping and Modelling the Geographical Distribution and Environmental Limits of Podoconiosis in Ethiopia.

Directory of Open Access Journals (Sweden)

Kebede Deribe

Full Text Available Ethiopia is assumed to have the highest burden of podoconiosis globally, but the geographical distribution and environmental limits and correlates are yet to be fully investigated. In this paper we use data from a nationwide survey to address these issues.Our analyses are based on data arising from the integrated mapping of podoconiosis and lymphatic filariasis (LF conducted in 2013, supplemented by data from an earlier mapping of LF in western Ethiopia in 2008-2010. The integrated mapping used woreda (district health offices' reports of podoconiosis and LF to guide selection of survey sites. A suite of environmental and climatic data and boosted regression tree (BRT modelling was used to investigate environmental limits and predict the probability of podoconiosis occurrence.Data were available for 141,238 individuals from 1,442 communities in 775 districts from all nine regional states and two city administrations of Ethiopia. In 41.9% of surveyed districts no cases of podoconiosis were identified, with all districts in Affar, Dire Dawa, Somali and Gambella regional states lacking the disease. The disease was most common, with lymphoedema positivity rate exceeding 5%, in the central highlands of Ethiopia, in Amhara, Oromia and Southern Nations, Nationalities and Peoples regional states. BRT modelling indicated that the probability of podoconiosis occurrence increased with increasing altitude, precipitation and silt fraction of soil and decreased with population density and clay content. Based on the BRT model, we estimate that in 2010, 34.9 (95% confidence interval [CI]: 20.2-51.7 million people (i.e. 43.8%; 95% CI: 25.3-64.8% of Ethiopia's national population lived in areas environmentally suitable for the occurrence of podoconiosis.Podoconiosis is more widespread in Ethiopia than previously estimated, but occurs in distinct geographical regions that are tied to identifiable environmental factors. The resultant maps can be used to guide

Description of the male of Eburella pinima Martins and notes on the geographical distribution of Eburodacrys aenigma Galileo & Martins and Eburodacrys lanei Zajciw (Coleoptera, Cerambycidae

Directory of Open Access Journals (Sweden)

Juan Pablo Botero

2013-12-01

Full Text Available Description of the male of Eburella pinima Martins and notes on the geographical distribution of Eburodacrys aenigma Galileo & Martins and Eburodacrys lanei Zajciw (Coleoptera, Cerambycidae. The male of Eburella pinima Martins, 1997 is described and illustrated for the first time. Information on Eburodacrys aenigma Galileo & Martins, 2006, previously known only from the female holotype, which lacked locality label, is herein complemented. This species is recorded from Brazil and the male is depicted for the first time. The geographical distribution of Eburodacrys lanei Zajciw, 1958 is further restricted here as some previous records are confirmed to result from misidentifications of E. aenigma.

Estimation of current density distribution under electrodes for external defibrillation

Directory of Open Access Journals (Sweden)

Papazov Sava P

2002-12-01

Full Text Available Abstract Background Transthoracic defibrillation is the most common life-saving technique for the restoration of the heart rhythm of cardiac arrest victims. The procedure requires adequate application of large electrodes on the patient chest, to ensure low-resistance electrical contact. The current density distribution under the electrodes is non-uniform, leading to muscle contraction and pain, or risks of burning. The recent introduction of automatic external defibrillators and even wearable defibrillators, presents new demanding requirements for the structure of electrodes. Method and Results Using the pseudo-elliptic differential equation of Laplace type with appropriate boundary conditions and applying finite element method modeling, electrodes of various shapes and structure were studied. The non-uniformity of the current density distribution was shown to be moderately improved by adding a low resistivity layer between the metal and tissue and by a ring around the electrode perimeter. The inclusion of openings in long-term wearable electrodes additionally disturbs the current density profile. However, a number of small-size perforations may result in acceptable current density distribution. Conclusion The current density distribution non-uniformity of circular electrodes is about 30% less than that of square-shaped electrodes. The use of an interface layer of intermediate resistivity, comparable to that of the underlying tissues, and a high-resistivity perimeter ring, can further improve the distribution. The inclusion of skin aeration openings disturbs the current paths, but an appropriate selection of number and size provides a reasonable compromise.

Geographic variation in ectoparasitic mites diversity in Tadarida Brasiliensis (Chiroptera, Molossidae

Directory of Open Access Journals (Sweden)

Tatiana C. Pesenti

2014-12-01

Full Text Available Tadarida brasiliensis (Geoffroy, 1824, the Brazilian free-tailed bat, is an insectivorous bat that occurs from southern United States of America to southern South America. In this study we present the first data on diversity of ectoparasitic mites of T. brasiliensis in Brazil. A compilation and analysis of the studies of mite diversity conducted in different points the geographic distribution this bat species are provided. The mites were collected from March 2010 to November 2011 on 160 T. brasiliensis adult bats captured in southern Brazil. Four species of mites have been found: Chiroptonyssus robustipes (Ewing, 1925, Ewingana longa (Ewing, 1938, Ewingana inaequalis (Radford, 1948, and specimens of Cheyletidae. Chiroptonyssus robustipes was the most prevalent species (100%, followed by E. longa (20%, E. inaequalis (10%, and specimens of Cheyletidae (1.25%. The data currently available show that C. robustipes parasitizes T. brasiliensis throughout its region of occurrence, and this mite is highly prevalent and abundant. The two species of Ewingana accompany the geographical distribution of T. brasiliensis, but with much lower prevalence and abundance.

Geographic Analysis of Neurosurgery Workforce in Korea

Science.gov (United States)

Park, Hye Ran; Park, Sukh Que; Kim, Jae Hyun; Hwang, Jae Chan; Lee, Gwang Soo; Chang, Jae-Chil

2018-01-01

Objective In respect of the health and safety of the public, universal access to health care is an issue of the greatest importance. The geographic distribution of doctors is one of the important factors contributing to access to health care. The aim of this study is to assess the imbalances in the geographic distribution of neurosurgeons across Korea. Methods Population data was obtained from the National Statistical Office. We classified geographic groups into 7 metropolitan cities, 78 non-metropolitan cities, and 77 rural areas. The number of doctors and neurosurgeons per 100000 populations in each county unit was calculated using the total number of doctors and neurosurgeons at the country level from 2009 to 2015. The density levels of neurosurgeon and doctor were calculated and depicted in maps. Results Between 2009 and 2015, the number of neurosurgeons increased from 2002 to 2557, and the ratio of neurosurgeons per 100000 populations increased from 4.02 to 4.96. The number of neurosurgeons per 100000 populations was highest in metropolitan cities and lowest in rural areas from 2009 to 2015. A comparison of the geographic distribution of neurosurgeons in 2009 and 2015 showed an increase in the regional gap. The neurosurgeon density was affected by country unit characteristics (p=0.000). Conclusion Distribution of neurosurgeons throughout Korea is uneven. Neurosurgeons are being increasingly concentrated in a limited number of metropolitan cities. This phenomenon will need to be accounted when planning for a supply of neurosurgeons, allocation of resources and manpower, and the provision of regional neurosurgical services. PMID:29354242

Geographic Analysis of Neurosurgery Workforce in Korea.

Science.gov (United States)

Park, Hye Ran; Park, Sukh Que; Kim, Jae Hyun; Hwang, Jae Chan; Lee, Gwang Soo; Chang, Jae-Chil

2018-01-01

In respect of the health and safety of the public, universal access to health care is an issue of the greatest importance. The geographic distribution of doctors is one of the important factors contributing to access to health care. The aim of this study is to assess the imbalances in the geographic distribution of neurosurgeons across Korea. Population data was obtained from the National Statistical Office. We classified geographic groups into 7 metropolitan cities, 78 non-metropolitan cities, and 77 rural areas. The number of doctors and neurosurgeons per 100000 populations in each county unit was calculated using the total number of doctors and neurosurgeons at the country level from 2009 to 2015. The density levels of neurosurgeon and doctor were calculated and depicted in maps. Between 2009 and 2015, the number of neurosurgeons increased from 2002 to 2557, and the ratio of neurosurgeons per 100000 populations increased from 4.02 to 4.96. The number of neurosurgeons per 100000 populations was highest in metropolitan cities and lowest in rural areas from 2009 to 2015. A comparison of the geographic distribution of neurosurgeons in 2009 and 2015 showed an increase in the regional gap. The neurosurgeon density was affected by country unit characteristics ( p =0.000). Distribution of neurosurgeons throughout Korea is uneven. Neurosurgeons are being increasingly concentrated in a limited number of metropolitan cities. This phenomenon will need to be accounted when planning for a supply of neurosurgeons, allocation of resources and manpower, and the provision of regional neurosurgical services.

The Geographical Distribution of Leadership in Globalized Clinical Trials

NARCIS (Netherlands)

Hoekman, J.; Frenken, K.; de Zeeuw, D.; Lambers-Heerspink, H.J.

2012-01-01

Background: Pharmaceutical trials are mainly initiated by sponsors and investigators in the United States, Western Europe and Japan. However, more and more patients are enrolled in Central and Eastern Europe, Latin America and Asia. The involvement of patients in new geographical settings raises

Geographical distribution of protozoan and metazoan parasites of farmed Nile tilapia Oreochromis niloticus (L.) (Perciformes: Cichlidae) in Yucatán, México.

Science.gov (United States)

Paredes-Trujillo, Amelia; Velázquez-Abunader, Iván; Torres-Irineo, Edgar; Romero, David; Vidal-Martínez, Víctor Manuel

2016-02-03

In Yucatán State, southern México, as in many other parts of the world where tilapia has been introduced for aquaculture, the deficient application of management measures has led to the establishment of non-native parasites. The aims of this study were to describe the geographical distribution of protozoan and helminth parasites of farmed Nile tilapia Oreochromis niloticus (L.) throughout the Yucatán and to examine the potential statistical associations of the prevalence and mean abundance of these parasites with management and environmental variables. All 29 Nile tilapia farms currently operating in Yucatán were surveyed. Maps were created to describe the geographical location of the parasites infecting Nile tilapia at each farm. We evaluated the statistical associations of management and environmental variables with the mean abundance values of each parasite species using a multivariate redundancy analysis (RDA) and generalized additive models (GAM). We also used Ripley's K to determine whether there were significant clusters of the mean abundance of particular parasite species in specific regions of the Yucatán State. A total of 580 O. niloticus were examined, and 11 species of parasites were recorded. Cichlidogyrus sclerosus was the most frequent and abundant parasite at all 29 farms, whereas Gyrodactylus cichlidarum was found in 26 of the 29 farms. The RDA showed that the most important predictors were the concentration of nitrites and ammonium and the water exchange rate. The GAM showed the significant effect of the tank capacity, no use of quarantine area and no use of prophylactic treatments on the mean abundance of G. cichlidarum. The geographical distribution patterns of the mean abundance of most parasite species exhibited clustering near to the coast of Yucatán. Two groups of farms were distinguished: (i) farms with medium to high technology, where the most frequent and abundant parasite was G. cichlidarum, and (ii) farms with low technology

distribution of euphausiid crustaceans from the agulhas current

African Journals Online (AJOL)

may set up a northeasterly counter-current close to the coast and cause local upwelling (aowes. 1950; Darbyshire 1964). The Agulhas Current shows considerable seasonal variation in its rate of flow (Darbyshire. 1964) and ...... detailed study of the biology and distribution of this interesting species in eastern Cape coastal.

Distributed team innovation - a framework for distributed product development

OpenAIRE

Larsson, Andreas; Törlind, Peter; Karlsson, Lennart; Mabogunje, Ade; Leifer, Larry; Larsson, Tobias; Elfström, Bengt-Olof

2003-01-01

In response to the need for increased effectivity in global product development, the Polhem Laboratory at Luleå University of Technology, Sweden, and the Center for Design Research at Stanford University, USA, have created the concept of Distributed Team Innovation (DTI). The overall aim of the DTI framework is to decrease the negative impact of geographic distance on product development efforts and to further enhance current advantages of worldwide, multidisciplinary collaboration. The DTI ...

A Geographic Method for High Resolution Spatial Heat Planning

DEFF Research Database (Denmark)

Nielsen, Steffen

2014-01-01

more detailed modelling that takes the geographic placement of buildings and the differences among DH systems into account. In the present article, a method for assessing the costs of DH expansions has been developed. The method was applied in a geographic information system (GIS) model that consists...... are considering distribution costs based on the geographic properties of each area and assessing transmission costs based on an iterative process that examines expansion potentials gradually. The GIS model is only applicable to a Danish context, but the method itself can be applied to other countries....... of three parts and assesses the costs of heat production, distribution, and transmission. The model was also applied to an actual case in order to show how it can be used. The model shows many improvements in the method for the assessment of distribution costs and transmission costs. Most notable...

Current distribution in a plasma erosion opening switch

International Nuclear Information System (INIS)

Weber, B.V.; Commisso, R.J.; Meger, R.A.; Neri, J.M.; Oliphant, W.F.; Ottinger, P.F.

1984-01-01

The current distribution in a plasma erosion opening switch is determined from magnetic field probe data. During the closed state of the switch the current channel broadens rapidly. The width of the current channel is consistent with a bipolar current density limit imposed by the ion flux to the cathode. The effective resistivity of the current channel is anomalously large. Current is diverted to the load when a gap opens near the cathode side of the switch. The observed gap opening can be explained by erosion of the plasma. Magnetic pressure is insufficient to open the gap

Current distribution in a plasma erosion opening switch

International Nuclear Information System (INIS)

Weber, B.V.; Commisso, R.J.; Meger, R.A.; Neri, J.M.; Oliphant, W.F.; Ottinger, P.F.

1985-01-01

The current distribution in a plasma erosion opening switch is determined from magnetic field probe data. During the closed state of the switch the current channel broadens rapidly. The width of the current channel is consistent with a bipolar current density limit imposed by the ion flux to the cathode. The effective resistivity of the current channel is anomalously large. Current is diverted to the load when a gap opens near the cathode side of the switch. The observed gap opening can be explained by erosion of the plasma. Magnetic pressure is insufficient to open the gap

Imaging of current distributions in superconducting thin film structures

International Nuclear Information System (INIS)

Doenitz, D.

2006-01-01

Local analysis plays an important role in many fields of scientific research. However, imaging methods are not very common in the investigation of superconductors. For more than 20 years, Low Temperature Scanning Electron Microscopy (LTSEM) has been successfully used at the University of Tuebingen for studying of condensed matter phenomena, especially of superconductivity. In this thesis LTSEM was used for imaging current distributions in different superconducting thin film structures: - Imaging of current distributions in Josephson junctions with ferromagnetic interlayer, also known as SIFS junctions, showed inhomogeneous current transport over the junctions which directly led to an improvement in the fabrication process. An investigation of improved samples showed a very homogeneous current distribution without any trace of magnetic domains. Either such domains were not present or too small for imaging with the LTSEM. - An investigation of Nb/YBCO zigzag Josephson junctions yielded important information on signal formation in the LTSEM both for Josephson junctions in the short and in the long limit. Using a reference junction our signal formation model could be verified, thus confirming earlier results on short zigzag junctions. These results, which could be reproduced in this work, support the theory of d-wave symmetry in the superconducting order parameter of YBCO. Furthermore, investigations of the quasiparticle tunneling in the zigzag junctions showed the existence of Andreev bound states, which is another indication of the d-wave symmetry in YBCO. - The LTSEM study of Hot Electron Bolometers (HEB) allowed the first successful imaging of a stable 'Hot Spot', a self-heating region in HEB structures. Moreover, the electron beam was used to induce an - otherwise unstable - hot spot. Both investigations yielded information on the homogeneity of the samples. - An entirely new method of imaging the current distribution in superconducting interference devices

Determinants of the geographical distribution of endemic giardiasis in Ontario, Canada: a spatial modelling approach.

Science.gov (United States)

Odoi, A; Martin, S W; Michel, P; Holt, J; Middleton, D; Wilson, J

2004-10-01

Giardiasis surveillance data as well as drinking water, socioeconomic and land-use data were used in spatial regression models to investigate determinants of the geographic distribution of endemic giardiasis in southern Ontario. Higher giardiasis rates were observed in areas using surface water [rate ratio (RR) 2.36, 95 % CI 1.38-4.05] and in rural areas (RR 1.79, 95 % CI 1.32-2.37). Lower rates were observed in areas using filtered water (RR 0.55, 95 % CI 0.42-0.94) and in those with high median income (RR 0.62, 95 % CI 0.42-0.92). Chlorination of drinking water, cattle density and intensity of manure application on farmland were not significant determinants. The study shows that waterborne transmission plays an important role in giardiasis distribution in southern Ontario and that well-collected routine surveillance data could be useful for investigation of disease determinants and identification of high-risk communities. This information is useful in guiding decisions on control strategies.

Ecological and Geographical Analysis of the Distribution of the Mountain Tapir (Tapirus pinchaque) in Ecuador: Importance of Protected Areas in Future Scenarios of Global Warming

Science.gov (United States)

Ortega-Andrade, H. Mauricio; Prieto-Torres, David A.; Gómez-Lora, Ignacio; Lizcano, Diego J.

2015-01-01

In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque’s potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador. PMID:25798851

Ecological and geographical analysis of the distribution of the mountain tapir (Tapirus pinchaque in Ecuador: importance of protected areas in future scenarios of global warming.

Directory of Open Access Journals (Sweden)

H Mauricio Ortega-Andrade

Full Text Available In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17% occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque's potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48% of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador.

Ecological and geographical analysis of the distribution of the mountain tapir (Tapirus pinchaque) in Ecuador: importance of protected areas in future scenarios of global warming.

Science.gov (United States)

Ortega-Andrade, H Mauricio; Prieto-Torres, David A; Gómez-Lora, Ignacio; Lizcano, Diego J

2015-01-01

In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque's potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador.

Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species.

Science.gov (United States)

Monahan, William B; Pereira, Ricardo J; Wake, David B

2012-03-12

In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (barriers - formed by groups of barriers (each 184,000 to 1.7 million km2) in close geographic proximity (totaling 1.9 to 2.3 million km2) - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no a priori information on the relative importance of features that define barriers, (ii) can be replicated using any kind of continuously distributed environmental variable, and (iii) generates spatially explicit hypotheses of

Molecular Identification of Paramecium bursaria Syngens and Studies on Geographic Distribution using Mitochondrial Cytochrome C Oxidase Subunit I (COI).

Science.gov (United States)

Zagata, Patrycja; Greczek-Stachura, Magdalena; Tarcz, Sebastian; Rautian, Maria

2015-01-01

Paramecium bursaria is composed of five syngens that are morphologically indistinguishable but sexually isolated. The aim of the present study was to confirm by molecular methods (analyses of mitochondrial COI) the identification of P. bursaria syngens originating from different geographical locations. Phylograms constructed using both the neighbor-joining and maximum-likelihood methods based on a comparison of 34 sequences of P. bursaria strains and P. multimicronucleatum, P. caudatum and P.calkinsi strains used as outgroups revealed five clusters which correspond to results obtained previously by mating reaction. Our analysis shows the existence of 24 haplotypes for the COI gene sequence in the studied strains. The interspecies haplotype diversity was Hd = 0.967. We confirmed genetic differentiation between strains of P. bursaria and the occurrence of a correlation between geographical distribution and the correspondent syngen.

Review of Current Geographic Information Systems Technology for TxDOT Pavement Management Information System

Science.gov (United States)

1998-05-01

A geographic information system (GIS) is a tool for effectively managing and analyzing tremendous amounts of geographic information. It employs the essential principle of geography to organize in formation and express relationships between real-world...

Current Density Distribution on the Perimeter of Waveguide Exciter Cylindrical Vibrator Conductor

OpenAIRE

Zakharia, Yosyp

2010-01-01

On ground of electrodynamic analysis the surface current distribution nonuniformity on the perimeter of waveguide-exciter cylindrical conductor is found. Considerable influence of current distribution nonuniformity on exciter input reactance is established. It is also showed, that the current distribution on the vibrator perimeter, for conductor radius no greater then 0,07 of waveguide cross section breadth, approximately uniform is.

The geographical co-distribution and socio-ecological drivers of childhood pneumonia and diarrhoea in Queensland, Australia.

Science.gov (United States)

Xu, Z; Hu, W; Tong, S

2015-04-01

SUMMARY This study aimed to explore the spatio-temporal patterns, geographical co-distribution, and socio-ecological drivers of childhood pneumonia and diarrhoea in Queensland. A Bayesian conditional autoregressive model was used to quantify the impacts of socio-ecological factors on both childhood pneumonia and diarrhoea at a postal area level. A distinct seasonality of childhood pneumonia and diarrhoea was found. Childhood pneumonia and diarrhoea were mainly distributed in the northwest of Queensland. Mount Isa city was the high-risk cluster where childhood pneumonia and diarrhoea co-distributed. Emergency department visits (EDVs) for pneumonia increased by 3% per 10-mm increase in monthly average rainfall in wet seasons. By comparison, a 10-mm increase in monthly average rainfall may cause an increase of 4% in EDVs for diarrhoea. Monthly average temperature was negatively associated with EDVs for childhood diarrhoea in wet seasons. Low socioeconomic index for areas (SEIFA) was associated with high EDVs for childhood pneumonia. Future pneumonia and diarrhoea prevention and control measures in Queensland should focus more on Mount Isa.

Modeling species’ realized climatic niche space and predicting their response to global warming for several western forest species with small geographic distributions

Science.gov (United States)

Marcus V. Warwell; Gerald E. Rehfeldt; Nicholas L. Crookston

2010-01-01

The Random Forests multiple regression tree was used to develop an empirically based bioclimatic model of the presence-absence of species occupying small geographic distributions in western North America. The species assessed were subalpine larch (Larix lyallii), smooth Arizona cypress (Cupressus arizonica ssp. glabra...

Estimating cyclopoid copepod species richness and geographical distribution (Crustacea across a large hydrographical basin: comparing between samples from water column (plankton and macrophyte stands

Directory of Open Access Journals (Sweden)

Gilmar Perbiche-Neves

2014-06-01

Full Text Available Species richness and geographical distribution of Cyclopoida freshwater copepods were analyzed along the "La Plata" River basin. Ninety-six samples were taken from 24 sampling sites, twelve sites for zooplankton in open waters and twelve sites for zooplankton within macrophyte stands, including reservoirs and lotic stretches. There were, on average, three species per sample in the plankton compared to five per sample in macrophytes. Six species were exclusive to the plankton, 10 to macrophyte stands, and 17 were common to both. Only one species was found in similar proportions in plankton and macrophytes, while five species were widely found in plankton, and thirteen in macrophytes. The distinction between species from open water zooplankton and macrophytes was supported by nonmetric multidimensional analysis. There was no distinct pattern of endemicity within the basin, and double sampling contributes to this result. This lack of sub-regional faunal differentiation is in accordance with other studies that have shown that cyclopoids generally have wide geographical distribution in the Neotropics and that some species there are cosmopolitan. This contrasts with other freshwater copepods such as Calanoida and some Harpacticoida. We conclude that sampling plankton and macrophytes together provided a more accurate estimate of the richness and geographical distribution of these organisms than sampling in either one of those zones alone.

How far could the alien boatman Trichocorixa verticalis verticalis spread? Worldwide estimation of its current and future potential distribution.

Directory of Open Access Journals (Sweden)

Simone Guareschi

Full Text Available Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv is a corixid (Hemiptera originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of

How Far Could the Alien Boatman Trichocorixa verticalis verticalis Spread? Worldwide Estimation of Its Current and Future Potential Distribution

Science.gov (United States)

Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J.; Millán, Andrés

2013-01-01

Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on

Transient current distributions in porous zinc electrodes in KOH electrolyte

Energy Technology Data Exchange (ETDEWEB)

Liu, M.B.; Yamazaki, Y.; Cook, G.M.; Yao, N.P.

1981-02-01

A zero-resistance ammeter circuit with a 10-channel operational amplifier was used to measure the current distribution during a discharge of 10 to 100 mA with simulated zinc porous electrodes in 7.24 M KOH saturated with ZnO. The reaction distribution was found to be highly nonuniform, with 70 to 78% of the charge transfer reaction completed in a depth of 0.01 cm. The high nonuniformity of the initial reaction profile was believed to be due to low conductivity of the electrolyte in the electrode pores. The current distribution changes during passivation of the electrode were experimentally obtained. A mathematical model based upon a macroscope averaging technique was used to predict the time dependence of charge transfer reaction profiles. With mathematical model, current distributions and overpotentials were predicted as a function of time for the segmented zinc electrode discharged at a current of 10 to 100 mA; for these predictions, assumed values of both precipitation rate constants for porous ZnO and diffusion coefficients for hydroxide and zincate ions were used. A gradual decrease in the specific conductivity of the pore electrolyte to 20% of the initial value during discharge yields predictions of current distributions and overpotentials in good agreement with the experimental data. The extent of reduction in the specific conductivity of the pore electrolyte implies a supersaturation of zincate of four times chemical saturation, which was been observed experimentally.At high discharge current (25 to 100 mA), the passivation behavior of the electrode has been simulated. The results of the experiments and mathematical model show that the effective reaction penetration depth is less than 0.02 cm.

Effect of a superconducting coil as a fault current limiter on current density distribution in BSCCO tape after an over-current pulse

International Nuclear Information System (INIS)

Tallouli, M; Yamaguchi, S.; Shyshkin, O.

2017-01-01

The development of power transmission lines based on long-length high temperature superconducting (HTS) tapes is complicated and technically challenging task. A serious problem for transmission line operation could become HTS power cable damage due to over-current pulse conditions. To avoid the cable damage in any urgent case the superconducting coil technology, i.e. superconductor fault current limiter (SFCL) is required. Comprehensive understanding of the current density characteristics of HTS tapes in both cases, either after pure over-current pulse or after over-current pulse limited by SFCL, is needed to restart or to continue the operation of the power transmission line. Moreover, current density distribution along and across the HTS tape provides us with the sufficient information about the quality of the tape performance in different current feeding regimes. In present paper we examine BSCCO HTS tape under two current feeding regimes. The first one is 100A feeding preceded by 900A over-current pulse. In this case none of tape protection was used. The second scenario is similar to the fist one but SFCL is used to limit an over-current value. For both scenarios after the pulse is gone and the current feeding is set up at 100A we scan magnetic field above the tape by means of Hall probe sensor. Then the feeding is turned of and the magnetic field scanning is repeated. Using the inverse problem numerical solver we calculate the corresponding direct and permanent current density distributions during the feeding and after switch off. It is demonstrated that in the absence of SFCL the current distribution is highly peaked at the tape center. At the same time the current distribution in the experiment with SFCL is similar to that observed under normal current feeding condition. The current peaking in the first case is explained by the effect of an opposite electric field induced at the tape edges during the overcurrent pulse decay, and by degradation of

Advertisement call of Dendropsophus studerae (Carvalho-e-Silva, Carvalho-e-Silva and Izecksohn, 2003) (Anura: Hylidae), with new record and geographic distribution extension.

Science.gov (United States)

Napoli, Marcelo Felgueiras; De Abreu, Rafael Oliveira; Cruz, Deise; Herrera, Jocilene Brandão; Petersen, Emanuela; Klein, Wilfried

2014-10-30

The treefrog genus Dendropsophus Fitzinger comprises 95 species, with geographic distribution from northern Argentina and Uruguay north through tropical South and Central America to tropical southern Mexico (Frost 2014). Dendropsophus studerae was included in the D. microcephalus clade by Faivovich et al. (2005), which currently consists of 39 species (Frost 2014). The species that most resembles D. studerae is D. bipunctatus (Spix), as already stated in the original description of the former (Carvalho-e-Silva et al. 2003). Thus far, Dendropsophus studerae was only known from its type locality, in the municipality of Quebrangulo (09º19'08"S, 36º28'16"W), State of Alagoas, northeastern Brazil. The original description of the species also included data on its eggs, tadpole (oral disc and external morphology) and some natural history information of adults and larvae, but its advertisement call remains undescribed. 

Predicting the current and future potential distributions of lymphatic filariasis in Africa using maximum entropy ecological niche modelling.

Directory of Open Access Journals (Sweden)

Hannah Slater

Full Text Available Modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. Here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (LF, in Africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. We used 508 community-specific infection presence data collated from the published literature in conjunction with five predictive environmental/climatic and demographic variables, and a maximum entropy niche modelling method to construct the first ecological niche maps describing potential distribution and burden of LF in Africa. We also ran the best-fit model against climate projections made by the HADCM3 and CCCMA models for 2050 under A2a and B2a scenarios to simulate the likely distribution of LF under future climate and population changes. We predict a broad geographic distribution of LF in Africa extending from the west to the east across the middle region of the continent, with high probabilities of occurrence in the Western Africa compared to large areas of medium probability interspersed with smaller areas of high probability in Central and Eastern Africa and in Madagascar. We uncovered complex relationships between predictor ecological niche variables and the probability of LF occurrence. We show for the first time that predicted climate change and population growth will expand both the range and risk of LF infection (and ultimately disease in an endemic region. We estimate that populations at risk to LF may range from 543 and 804 million currently, and that this could rise to between 1.65 to 1.86 billion in the future depending on the climate scenario used and thresholds applied to signify infection presence.

Geographic distribution of otolaryngologists in the United States.

Science.gov (United States)

Vickery, Thad W; Weterings, Robbie; Cabrera-Muffly, Cristina

2016-06-01

We conducted a study to determine the demographic traits, training characteristics, and geographic distribution of otolaryngologists in the United States using publicly available data. We then correlated our findings with U.S. census data. Univariate analysis was performed to analyze results, with a p value of <0.05 determined as significant. We used data from the American Board of Otolaryngology's list of 18,587 board-certified allopathic otolaryngologists through 2013 and the American Osteopathic Colleges of Ophthalmology & Otolaryngology-Head & Neck Surgery's list of 428 osteopathic otolaryngologists. From these two databases, 9,642 otolaryngologists met inclusion criteria, which included an active practice in the United States and an age of 70 years and younger. This group was made up of 8,185 men (84.9%) and 1,449 women (15.0%); we were not able to identify the sex of 8 otolaryngologists (0.1%). The median age of the women was significantly lower than that of the men (54 vs. 48 yr; p < 0.001). A total of 8,510 otolaryngologists (88.3%) graduated from a U.S. allopathic medical school, and 8,520 (88.4%) graduated from a U.S. allopathic residency program. We determined that 25.9% of otolaryngologists established their practice in the same metropolitan statistical area where they completed their residency training. Older practitioners (p < 0.001) and women (p < 0.001) were significantly more likely to stay in the same area than younger physicians and men. In terms of population, 61.8% of the otolaryngologists practiced in metropolitan areas with more than 1 million residents; by comparison, these areas represent only 55.3% of the total U.S. population, indicating that otolaryngologists are over-represented in larger U.S. cities.

Identification of geographically distributed sub-populations of Leishmania (Leishmania major by microsatellite analysis

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Schwenkenbecher Jan

2008-06-01

Full Text Available Abstract Background Leishmania (Leishmania major, one of the agents causing cutaneous leishmaniasis (CL in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of L. (L. major isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of Leishmania. Results Multilocus Microsatellite Typing (MLMT based on 10 different microsatellite markers was applied to 106 strains of L. (L. major from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA; the Middle East (ME; and Africa (AF. This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration. Conclusion The model- and distance-based analyses of the microsatellite data exposed three main populations of L. (L. major, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.

Species-free species distribution models describe macroecological properties of protected area networks.

Science.gov (United States)

Robinson, Jason L; Fordyce, James A

2017-01-01

Among the greatest challenges facing the conservation of plants and animal species in protected areas are threats from a rapidly changing climate. An altered climate creates both challenges and opportunities for improving the management of protected areas in networks. Increasingly, quantitative tools like species distribution modeling are used to assess the performance of protected areas and predict potential responses to changing climates for groups of species, within a predictive framework. At larger geographic domains and scales, protected area network units have spatial geoclimatic properties that can be described in the gap analysis typically used to measure or aggregate the geographic distributions of species (stacked species distribution models, or S-SDM). We extend the use of species distribution modeling techniques in order to model the climate envelope (or "footprint") of individual protected areas within a network of protected areas distributed across the 48 conterminous United States and managed by the US National Park System. In our approach we treat each protected area as the geographic range of a hypothetical endemic species, then use MaxEnt and 5 uncorrelated BioClim variables to model the geographic distribution of the climatic envelope associated with each protected area unit (modeling the geographic area of park units as the range of a species). We describe the individual and aggregated climate envelopes predicted by a large network of 163 protected areas and briefly illustrate how macroecological measures of geodiversity can be derived from our analysis of the landscape ecological context of protected areas. To estimate trajectories of change in the temporal distribution of climatic features within a protected area network, we projected the climate envelopes of protected areas in current conditions onto a dataset of predicted future climatic conditions. Our results suggest that the climate envelopes of some parks may be locally unique or have

Fungi identify the geographic origin of dust samples.

Directory of Open Access Journals (Sweden)

Neal S Grantham

Full Text Available There is a long history of archaeologists and forensic scientists using pollen found in a dust sample to identify its geographic origin or history. Such palynological approaches have important limitations as they require time-consuming identification of pollen grains, a priori knowledge of plant species distributions, and a sufficient diversity of pollen types to permit spatial or temporal identification. We demonstrate an alternative approach based on DNA sequencing analyses of the fungal diversity found in dust samples. Using nearly 1,000 dust samples collected from across the continental U.S., our analyses identify up to 40,000 fungal taxa from these samples, many of which exhibit a high degree of geographic endemism. We develop a statistical learning algorithm via discriminant analysis that exploits this geographic endemicity in the fungal diversity to correctly identify samples to within a few hundred kilometers of their geographic origin with high probability. In addition, our statistical approach provides a measure of certainty for each prediction, in contrast with current palynology methods that are almost always based on expert opinion and devoid of statistical inference. Fungal taxa found in dust samples can therefore be used to identify the origin of that dust and, more importantly, we can quantify our degree of certainty that a sample originated in a particular place. This work opens up a new approach to forensic biology that could be used by scientists to identify the origin of dust or soil samples found on objects, clothing, or archaeological artifacts.

Nonequilibrium Distribution of the Microscopic Thermal Current in Steady Thermal Transport Systems

KAUST Repository

Yukawa, Satoshi; Ogushi, Fumiko; Shimada, Takashi; Ito, Nobuyasu

2010-01-01

Nonequilibrium distribution of the microscopic thermal current is investigated by direct molecular dynamics simulations. The microscopic thermal current in this study is defined by a flow of kinetic energy carried by a single particle. Asymptotic parallel and antiparallel tails of the nonequilibrium distribution to an average thermal current are identical to ones of equilibrium distribution with different temperatures. These temperatures characterizing the tails are dependent on a characteristic length in which a memory of dynamics is completely erased by several particle collisions. This property of the tails of nonequilibrium distribution is confirmed in other thermal transport systems. In addition, statistical properties of a particle trapped by a harmonic potential in a steady thermal conducting state are also studied. This particle feels a finite force parallel to the average thermal current as a consequence of the skewness of the distribution of the current. This force is interpreted as the microscopic origin of thermophoresis.

Crack problem in superconducting cylinder with exponential distribution of critical-current density

Science.gov (United States)

Zhao, Yufeng; Xu, Chi; Shi, Liang

2018-04-01

The general problem of a center crack in a long cylindrical superconductor with inhomogeneous critical-current distribution is studied based on the extended Bean model for zero-field cooling (ZFC) and field cooling (FC) magnetization processes, in which the inhomogeneous parameter η is introduced for characterizing the critical-current density distribution in inhomogeneous superconductor. The effect of the inhomogeneous parameter η on both the magnetic field distribution and the variations of the normalized stress intensity factors is also obtained based on the plane strain approach and J-integral theory. The numerical results indicate that the exponential distribution of critical-current density will lead a larger trapped field inside the inhomogeneous superconductor and cause the center of the cylinder to fracture more easily. In addition, it is worth pointing out that the nonlinear field distribution is unique to the Bean model by comparing the curve shapes of the magnetization loop with homogeneous and inhomogeneous critical-current distribution.

Modeling the current distribution in HTS tapes with transport current and applied magnetic field

NARCIS (Netherlands)

Yazawa, T.; Yazawa, Takashi; Rabbers, J.J.; Chevtchenko, O.A.; ten Haken, Bernard; ten Kate, Herman H.J.; Maeda, Hideaki

1999-01-01

A numerical model is developed for the current distribution in a high temperature superconducting (HTS) tape, (Bi,Pb)2Sr2 Ca2Cu3Ox-Ag, subjected to a combination of a transport current and an applied magnetic field. This analysis is based on a two-dimensional formulation of Maxwell's equations in

Forensic genetic analysis of bio-geographical ancestry.

Science.gov (United States)

Phillips, Chris

2015-09-01

With the great strides made in the last ten years in the understanding of human population variation and the detailed characterization of the genome, it is now possible to identify sets of ancestry informative markers suitable for relatively small-scale PCR-based assays and use them to analyze the ancestry of an individual from forensic DNA. This review outlines some of the current understanding of past human population structure and how it may have influenced the complex distribution of contemporary human diversity. A simplified description of human diversity can provide a suitable basis for choosing the best ancestry-informative markers, which is important given the constraints of multiplex sizes in forensic DNA tests. It is also important to decide the level of geographic resolution that is realistic to ensure the balance between informativeness and an over-simplification of complex human diversity patterns. A detailed comparison is made of the most informative ancestry markers suitable for forensic use and assessments are made of the data analysis regimes that can provide statistical inferences of a DNA donor's bio-geographical ancestry. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Welding Current Distribution in the Work-piece and Pool in Arc Welding

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A. M. Rybachuk

2015-01-01

Full Text Available In order to select the optimal configuration of controlling magnetic fields and build rational construction of magnetic systems, we need to know the distribution of welding current in the molten metal of the weld pool. So the objective of the work is to establish the calculated methods for determining current density in the weld pool during arc welding. The distribution of welding current in the pool depends on the field of the electrical resistance, which is determined by the deformed temperature field while arc moves with the welding speed. The previous works have shown experimentally and by simulation on the conductive paper that deformation of temperature field defines deformation of electric field. On the basis thereof, under certain boundary conditions the problem has been solved to give a general solution of differential equation, which relates the potential distribution to the temperature in the product during arc welding. This solution is obtained under the following boundary conditions: 1 metal is homogeneous; 2 input and output surfaces of heat flux and electric current coincide; 3 input and output surfaces of heat flux and electric current are insulated and equipotential; 4 other (lateral surfaces are adiabatic boundaries. Therefore, this paper pays basic attention to obtaining the analytical solution of a general differential equation, which relates distribution of potential to the temperature in the product. It considers the temperature field of the heat source, which moves at a welding speed with normal-circular distribution of the heat flow at a certain concentration factor. The distribution of current density is calculated on the assumption that the welding current is introduced through the same surface as the heat flux and the distribution of current density corresponds to the normally circular at a certain concentration factor. As a result, we get an expression that allows us to calculate the current density from the known

Geographical differences in food allergy.

Science.gov (United States)

Bartra, Joan; García-Moral, Alba; Enrique, Ernesto

2016-06-01

Food allergy represents a health problem worldwide and leads to life-threatening reactions and even impairs quality of life. Epidemiological data during the past decades is very heterogeneous because of the use of different diagnostic procedures, and most studies have only been performed in specific geographical areas. The aim of this article is to review the available data on the geographical distribution of food allergies at the food source and molecular level and to link food allergy patterns to the aeroallergen influence in each area. Systematic reviews, meta-analysis, studies performed within the EuroPrevall Project and EAACI position papers regarding food allergy were analysed. The prevalence of food allergy sensitization differs between geographical areas, probably as a consequence of differences among populations, their habits and the influence of the cross-reactivity of aeroallergens and other sources of allergens. Geographical differences in food allergy are clearly evident at the allergenic molecular level, which seems to be directly influenced by the aeroallergens of each region and associated with specific clinical patterns.

Large-scale geographic variation in distribution and abundance of Australian deep-water kelp forests.

Directory of Open Access Journals (Sweden)

Ezequiel M Marzinelli

Full Text Available Despite the significance of marine habitat-forming organisms, little is known about their large-scale distribution and abundance in deeper waters, where they are difficult to access. Such information is necessary to develop sound conservation and management strategies. Kelps are main habitat-formers in temperate reefs worldwide; however, these habitats are highly sensitive to environmental change. The kelp Ecklonia radiate is the major habitat-forming organism on subtidal reefs in temperate Australia. Here, we provide large-scale ecological data encompassing the latitudinal distribution along the continent of these kelp forests, which is a necessary first step towards quantitative inferences about the effects of climatic change and other stressors on these valuable habitats. We used the Autonomous Underwater Vehicle (AUV facility of Australia's Integrated Marine Observing System (IMOS to survey 157,000 m2 of seabed, of which ca 13,000 m2 were used to quantify kelp covers at multiple spatial scales (10-100 m to 100-1,000 km and depths (15-60 m across several regions ca 2-6° latitude apart along the East and West coast of Australia. We investigated the large-scale geographic variation in distribution and abundance of deep-water kelp (>15 m depth and their relationships with physical variables. Kelp cover generally increased with latitude despite great variability at smaller spatial scales. Maximum depth of kelp occurrence was 40-50 m. Kelp latitudinal distribution along the continent was most strongly related to water temperature and substratum availability. This extensive survey data, coupled with ongoing AUV missions, will allow for the detection of long-term shifts in the distribution and abundance of habitat-forming kelp and the organisms they support on a continental scale, and provide information necessary for successful implementation and management of conservation reserves.

The Current State and Historico-geographical Background of Mt. Chirisan Region Immigrants

Directory of Open Access Journals (Sweden)

Sungho Kang

2016-08-01

Full Text Available This paper examined the historico-geographical background and current state of immigrants in the area designated as the “Mt. Chirisan Region,” their characteristics, and related integration issues. This article defines the Mt. Chirisan Region as the 7 cities/kuns of Namwŏn-si, Changsu-kun, Koksŏng-kun, Kurye-kun, Hadong-kun, Sanchŏng-kun, and Hamyang-kun. As the Mt. Chirisan Region mainly consists of mountainous and agricultural areas, the immigrant induction effect socio-economically was low relative to urban and industrial areas. It was also noted that, as the percentage of marriage immigration in Mt. Chirisan was high relative to urban or industrial areas, the female foreigner ratio was higher than that of male foreigners. In regard to the home countries of immigrants, women from South-East Asia and North-East Asia accounted for the majority. Also, this article examines the current situation of support programs of 7 local Multicultural Family Support Centers in the Mt. Chirisan Region, their problems, and probably solutions. Based on the historical development of the region and recent social changes, our society and government need to actively develop a higher level of social integration and employment education support programs, and carry out policies that will protect the diverse cultural identities of immigrants. In addition, differentiated multicultural family support programs appropriate for Mt. Chirisan, an inland mountain region, need to be developed.

Translocation 1;7 in dyshematopoiesis: possibly induced with a nonrandom geographic distribution

International Nuclear Information System (INIS)

Scheres, J.M.; Hustinx, T.W.; Holdrinet, R.S.; Geraedts, J.P.; Hagemeijer, A.; van der Blij-Philipsen, M.

1984-01-01

Eight patients with various hematologic disorders had an identical chromosomal aberration in their bone marrow or unstimulated peripheral blood, a translocation t(1;7) interpreted as t(1;7)(p11;p11). The translocation chromosome replaced one normal chromosome number7; therefore, the karyotype of the abnormal cells was trisomic for 1q and monosomic for 7q. Including four cases from the literature, a total of 12 patients (4 women, 8 men) with this translocation are known at the moment. The translocation does not seem to be associated with a specific disorder, but almost all patients had a preleukemic syndrome during some stage of their disease. It is very remarkable that 11 of the 12 patients lived in the Netherlands, and 7 patients had a history of iatrogenic exposure to alkylating agents or irradiation; one patient was a radiation worker and another one had a history of toxic exposure to chloramphenicol. It is suggested, therefore, that the t(1;7) is a possibly induced chromosomal aberration with a clearly nonrandom geographic distribution

Geographic variability in elevation and topographic constraints on the distribution of native and nonnative trout in the Great Basin

Science.gov (United States)

Warren, Dana R.; Dunham, Jason B.; Hockman-Wert, David

2014-01-01

Understanding local and geographic factors influencing species distributions is a prerequisite for conservation planning. Our objective in this study was to model local and geographic variability in elevations occupied by native and nonnative trout in the northwestern Great Basin, USA. To this end, we analyzed a large existing data set of trout presence (5,156 observations) to evaluate two fundamental factors influencing occupied elevations: climate-related gradients in geography and local constraints imposed by topography. We applied quantile regression to model upstream and downstream distribution elevation limits for each trout species commonly found in the region (two native and two nonnative species). With these models in hand, we simulated an upstream shift in elevation limits of trout distributions to evaluate potential consequences of habitat loss. Downstream elevation limits were inversely associated with latitude, reflecting regional gradients in temperature. Upstream limits were positively related to maximum stream elevation as expected. Downstream elevation limits were constrained topographically by valley bottom elevations in northern streams but not in southern streams, where limits began well above valley bottoms. Elevation limits were similar among species. Upstream shifts in elevation limits for trout would lead to more habitat loss in the north than in the south, a result attributable to differences in topography. Because downstream distributions of trout in the north extend into valley bottoms with reduced topographic relief, trout in more northerly latitudes are more likely to experience habitat loss associated with an upstream shift in lower elevation limits. By applying quantile regression to relatively simple information (species presence, elevation, geography, topography), we were able to identify elevation limits for trout in the Great Basin and explore the effects of potential shifts in these limits that could occur in response to changing

Geographic information system for pigweed distribution in the US Southeast

Science.gov (United States)

In the southeastern United States, pigweeds have become troublesome weeds in agricultural systems. To implement management strategies to control them, agriculturalists need information on areas affected by pigweeds. Geographic information systems (GIS) afford users the ability to evaluate agricult...

Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

Directory of Open Access Journals (Sweden)

Monahan William B

2012-03-01

relative importance of features that define barriers, (ii can be replicated using any kind of continuously distributed environmental variable, and (iii generates spatially explicit hypotheses of geographic species formation. The methods developed here - combined with study of the geographical ecology and genetics of taxa in their environments - should enable recognition of ring species phenomena throughout the world.

Comprehensive Monitoring for Heterogeneous Geographically Distributed Storage

Energy Technology Data Exchange (ETDEWEB)

Ratnikova, N. [Fermilab; Karavakis, E. [CERN; Lammel, S. [Fermilab; Wildish, T. [Princeton U.

2015-12-23

Storage capacity at CMS Tier-1 and Tier-2 sites reached over 100 Petabytes in 2014, and will be substantially increased during Run 2 data taking. The allocation of storage for the individual users analysis data, which is not accounted as a centrally managed storage space, will be increased to up to 40%. For comprehensive tracking and monitoring of the storage utilization across all participating sites, CMS developed a space monitoring system, which provides a central view of the geographically dispersed heterogeneous storage systems. The first prototype was deployed at pilot sites in summer 2014, and has been substantially reworked since then. In this paper we discuss the functionality and our experience of system deployment and operation on the full CMS scale.

Experimental results of current distribution in Rutherford-type LHC cables

CERN Document Server

Verweij, A P

2000-01-01

Current distribution among the wires of multi-strand superconducting cables is an important item for accelerator magnets. A non-uniform distribution could cause additional field distortions in the magnet bore and can as well be one of the reasons of premature quenching. Since two years electrical measurements on superconducting Rutherford-type cables are performed at CERN as part of the reception tests for the Large Hadron Collider (LHC). Cable samples of 2.4 m length are tested at currents up to 32 kA, temperatures around 1.9 and 4.3 K, and fields up to 10 T, applied perpendicularly as well as parallel to the broad face of the cable. Last year, an array of 24 Hall probes was installed in the test set-up in order to measure the self-field of the cable samples along one cable pitch. Each of the probes measures the local field generated by the current in the strands close by, and the results of the all probes reflect therefore the distribution of the strand currents. Experiments are done varying the applied fie...

New records and update on the geographic distribution of Clitocybula lignicola (Lj.N. Vassiljeva) E.F. Malysheva & O.V. Morozova (Basidiomycota: Agaricales) in Russia

OpenAIRE

Shiryaeva, Olga

2016-01-01

Clitocybula lignicola is predominantly distributed in the Asian part of Russia. In Europe it was found only in the Urals (Komi Republic, Russia). Two new localities are situated in the northwestern part of Vologda Region (Russia). These are the first records of this species from the East European Plain, as well as the most western ones known in Europe. New records extend the geographic distribution of C. lignicola 1,204 km west of the closest site in the Urals. An updated distribution map for...

Current and voltage distribution in the diffuse vacuum arc

NARCIS (Netherlands)

Schellekens, H.; Schram, D.C.

1985-01-01

On the basis of extensive measurements, a model is developed for the diffuse plasma of the high-current vacuum arc. The model shows that the current constriction and the voltage distribution in the diffuse vacuum arc prior to anode-spot formation are caused by the pressure source to which the

Spatial distribution of dengue disease in municipality of Mossoró, Rio Grande do Norte, using the Geographic Information System

Directory of Open Access Journals (Sweden)

Francisco Narcísio Bessa Júnior

2013-09-01

Full Text Available The dengue viral infection is one of the most relevant vector-borne diseases in the world. The disease can manifest in a variety of forms, from asymptomatic to a condition of dengue hemorrhagic fever (DHF. The last reported cases in Brazil correspond to 80% of the cases reported in the Americas, which emphasizes the magnitude of the problem. This study was conducted using Geographic Information System (GIS techniques, in order to evaluate the spatial distribution of the disease in the urban area of Mossoró, Rio Grande do Norte. In the period between 2001 and 2007, 867 new cases were listed. About 85.7% of the addresses were georeferenced, with a larger number of cases, 14.8%, in the neighborhoods of Santo Antônio and Santa Delmira (north region, and 11.7% in the neighborhoods of Conjunto Vingt-Rosado and Alto de São Manoel (east region. There were 18 confirmed cases of dengue hemorrhagic fever associated with regions with the highest incidence of classic cases of the disease. The use of Geographic Information System (GIS proved a great benefit for better visualization of the endemic, especially in elucidating the actual distribution of dengue cases in the county and providing an effective tool for planning the monitoring of the disease at a local level.

Impact of uniform electrode current distribution on ETF. [Engineering Test Facility MHD generator

Science.gov (United States)

Bents, D. J.

1982-01-01

A basic reason for the complexity and sheer volume of electrode consolidation hardware in the MHD ETF Powertrain system is the channel electrode current distribution, which is non-uniform. If the channel design is altered to provide uniform electrode current distribution, the amount of hardware required decreases considerably, but at the possible expense of degraded channel performance. This paper explains the design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution, and presents the alternate consolidation designs which occur. They are compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is presented for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

An Analysis of the Geographic Distribution of Recently Graduated Dentists from the University of Western Australia: The World's Most Isolated Dental School

Science.gov (United States)

Gurbuxani, Amit; Kruger, Estie; Tennant, Marc

2013-01-01

Objective: The purpose of this study was to determine the geographic distribution of all new dentists who graduated over a period of six years. Perth, the capital city of Western Australia, is one of the world's most isolated cities, with a population of approximately 1.6 million people, situated over 2000km from its nearest next major capital…

Distribution of ionospheric currents induced by the solar wind interaction with Venus

International Nuclear Information System (INIS)

Daniell, R.E. Jr.; Cloutier, P.A.

1977-01-01

The electric currents induced in the atmosphere of a non-magnetic planet such as Venus by the interaction of the solar wind satisfy a generalized Ohm's Law relationship with tensor conductivity. The distribution of these currents within the planetary ionosphere may be calculated by a variational technique which minimizes the Joule heating over the ionospheric volume. In this paper, we present the development of the variational technique, and apply it to a model of the solar wind interaction with Venus. Potential and current distributions are shown, and the use of these distributions in determining convective transport patterns of planetary ions is discussed. (author)

Temperature responses of some North Atlantic Cladophora species (Chlorophyceae) in relation to their geographic distribution

Science.gov (United States)

Cambridge, M.; Breeman, A. M.; van Oosterwijk, R.; van den Hoek, C.

1984-09-01

The temperature responses for growth and survival have been experimentally tested for 6 species of the green algal genus Cladophora (Chlorophyceae; Cladophorales) (all isolated from Roscoff, Brittany, France, one also from Connecticut, USA), selected from 4 distribution groups, in order to determine which phase in the annual temperature regime might prevent the spread of a species beyond its present latitudinal range on the N. Atlantic coasts. For five species geographic limits could be specifically defined as due to a growth limit in the growing season or to a lethal limit in the adverse season. These species were: (1) C. coelothrix (Amphiatlantic tropical to warm temperate), with a northern boundary on the European coasts formed by a summer growth limit near the 12°C August isotherm. On the American coasts sea temperatures should allow its occurrence further north. (2) C. vagabunda (Amphiatlantic tropical to temperate), with a northern boundary formed by a summer growth limit near the 15°C August isotherm on both sides of the Atlantic. (3) C. dalmatica, as for C. vagabunda. (4) C. hutchinsiae (Mediterranean-Atlantic warm temperate), with a northern boundary formed by a summer growth limit near the 12°C August isotherm, and possibly also a winter lethal limit near the 6°C February isotherm; and a southern boundary formed by a southern lethal limit near the 26°C August isotherm. It is absent from the warm temperate American coast because its lethal limits, 5° and 30°C, are regularly reached there. (5) Preliminary data for C. rupestris (Amphiatlantic temperate), suggest the southeastern boundary on the African coast to be a summer lethal limit near the 26°C August isotherm; the southwestern boundary on the American coast lies on the 20°C August isotherm. For one species, C. albida, the experimental growth and survival range was wider than expected from its geographic distribution, and reasons to account for this are suggested.

Genetic diversity and geographic distribution of genetically distinct rabies viruses in the Philippines.

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Mariko Saito

Full Text Available BACKGROUND: Rabies continues to be a major public health problem in the Philippines, where 200-300 human cases were reported annually between 2001 and 2011. Understanding the phylogeography of rabies viruses is important for establishing a more effective and feasible control strategy. METHODS: We performed a molecular analysis of rabies viruses in the Philippines using rabied animal brain samples. The samples were collected from 11 of 17 regions, which covered three island groups (Luzon, Visayas, and Mindanao. Partial nucleoprotein (N gene sequencing was performed on 57 samples and complete glycoprotein (G gene sequencing was performed on 235 samples collected between 2004 and 2010. RESULTS: The Philippine strains of rabies viruses were included in a distinct phylogenetic cluster, previously named Asian 2b, which appeared to have diverged from the Chinese strain named Asian 2a. The Philippine strains were further divided into three major clades, which were found exclusively in different island groups: clades L, V, and M in Luzon, Visayas, and Mindanao, respectively. Clade L was subdivided into nine subclades (L1-L9 and clade V was subdivided into two subclades (V1 and V2. With a few exceptions, most strains in each subclade were distributed in specific geographic areas. There were also four strains that were divided into two genogroups but were not classified into any of the three major clades, and all four strains were found in the island group of Luzon. CONCLUSION: We detected three major clades and two distinct genogroups of rabies viruses in the Philippines. Our data suggest that viruses of each clade and subclade evolved independently in each area without frequent introduction into other areas. An important implication of these data is that geographically targeted dog vaccination using the island group approach may effectively control rabies in the Philippines.

On the Inverse EEG Problem for a 1D Current Distribution

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George Dassios

2014-01-01

Full Text Available Albanese and Monk (2006 have shown that, it is impossible to recover the support of a three-dimensional current distribution within a conducting medium from the knowledge of the electric potential outside the conductor. On the other hand, it is possible to obtain the support of a current which lives in a subspace of dimension lower than three. In the present work, we actually demonstrate this possibility by assuming a one-dimensional current distribution supported on a small line segment having arbitrary location and orientation within a uniform spherical conductor. The immediate representation of this problem refers to the inverse problem of electroencephalography (EEG with a linear current distribution and the spherical model of the brain-head system. It is shown that the support is identified through the solution of a nonlinear algebraic system which is investigated thoroughly. Numerical tests show that this system has exactly one real solution. Exact solutions are analytically obtained for a couple of special cases.

Using geographical semi-variogram method to quantify the difference between NO2 and PM2.5 spatial distribution characteristics in urban areas.

Science.gov (United States)

Song, Weize; Jia, Haifeng; Li, Zhilin; Tang, Deliang

2018-08-01

Urban air pollutant distribution is a concern in environmental and health studies. Particularly, the spatial distribution of NO 2 and PM 2.5 , which represent photochemical smog and haze pollution in urban areas, is of concern. This paper presents a study quantifying the seasonal differences between urban NO 2 and PM 2.5 distributions in Foshan, China. A geographical semi-variogram analysis was conducted to delineate the spatial variation in daily NO 2 and PM 2.5 concentrations. The data were collected from 38 sites in the government-operated monitoring network. The results showed that the total spatial variance of NO 2 is 38.5% higher than that of PM 2.5 . The random spatial variance of NO 2 was 1.6 times than that of PM 2.5 . The nugget effect (i.e., random to total spatial variance ratio) values of NO 2 and PM 2.5 were 29.7 and 20.9%, respectively. This indicates that urban NO 2 distribution was affected by both local and regional influencing factors, while urban PM 2.5 distribution was dominated by regional influencing factors. NO 2 had a larger seasonally averaged spatial autocorrelation distance (48km) than that of PM 2.5 (33km). The spatial range of NO 2 autocorrelation was larger in winter than the other seasons, and PM 2.5 has a smaller range of spatial autocorrelation in winter than the other seasons. Overall, the geographical semi-variogram analysis is a very effective method to enrich the understanding of NO 2 and PM 2.5 distributions. It can provide scientific evidences for the buffering radius selection of spatial predictors for land use regression models. It will also be beneficial for developing the targeted policies and measures to reduce NO 2 and PM 2.5 pollution levels. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of current distribution in a large superconductor; Chodendo dotai nai no denryu bunpu kaiseki

Energy Technology Data Exchange (ETDEWEB)

Hamajima, K.; Alamgir, A.K.M.; Harada, N.; Tsuda, M. [Yamaguchi Univ., Yamaguchi (Japan); Ono, M.; Takano, H. [Toshiba Corp., Tokyo (Japan)

2000-04-25

An imbalanced current distribution is often observed in cable-in-conduit (CIC) superconductors, which are composed of multistaged, triplet type sub-cables, and deteriorates the performance of the coils. Therefore, it is very important to analyze the current distribution in a superconductor and find out methods to obtain a homogeneous current distribution in the conductor. We apply a magnetic flux conservation in a loop contoured by electric center lines of filaments in two arbitrary strands located on adjacent layers in a coaxial multilayer superconductor, and then analyze the current distribution in the conductor. A generalized formula governing the current distribution can be described as explicit functions of the superconductor construction parameters, such as twist pitch, twist direction and radius of each layer. It is shown that we can obtain a homogeneous current distribution using this fundamental formula, which is a function of the twist pitches of layers. Moreover, it is demonstrated that we can control current distribution in the coaxial superconductor. (author)

Polarized parton distributions from charged-current deep-inelastic scattering and future neutrino factories

CERN Document Server

Forte, Stefano; Ridolfi, G; Forte, Stefano; Mangano, Michelangelo L.; Ridolfi, Giovanni

2001-01-01

We discuss the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments. We summarize the next-to-leading order treatment of charged-current polarized structure functions, their relation to polarized parton distributions and scale dependence, and discuss their description by means of a next-to-leading order evolution code. We discuss current theoretical expectations and positivity constraints on the unmeasured C-odd combinations Delta q-Delta qbar of polarized quark distributions, and their determination in charged-current deep-inelastic scattering experiments. We give estimates of the expected errors on charged-current structure functions at a future neutrino factory, and perform a study of the accuracy in the determination of polarized parton distributions that would be possible at such a facility. We show that these measurements have the potential to distinguish between different theoretical scenarios for the proton spin structure.

Polarized parton distributions from charged-current deep-inelastic scattering and future neutrino factories

International Nuclear Information System (INIS)

Forte, Stefano; Mangano, Michelangelo L.; Ridolfi, Giovanni

2001-01-01

We discuss the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments. We summarize the next-to-leading-order treatment of charged-current polarized structure functions, their relation to polarized parton distributions and scale dependence, and discuss their description by means of a next-to-leading-order evolution code. We discuss current theoretical expectations and positivity constraints on the unmeasured C-odd combinations Δq-Δq-bar of polarized quark distributions, and their determination in charged-current deep-inelastic scattering experiments. We give estimates of the expected errors on charged-current structure functions at a future neutrino factory, and perform a study of the accuracy in the determination of polarized parton distributions that would be possible at such a facility. We show that these measurements have the potential to distinguish between different theoretical scenarios for the proton spin structure

New data on the ecology and geographic distribution of Saguinus inustus Schwarz, 1951 (Primates, Callitrichidae

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J. Valsecchi

Full Text Available Saguinus inustus (Schwarz, 1951 is one of the neotropical primates least studied. The distribution of the species ranges from the north of the Solimões River, between the Negro and Japurá Rivers in Brazil, and Guayabero-Guaviare Rivers in Colombia. Nevertheless, due to the low number of specimens collected from the lower Japurá and lower Negro Rivers areas, the geographic distribution is so far poorly delineated. In this study, field data was composed of sightings and the collection of specimens during a survey of mammal diversity in the Amana Sustainable Development Reserve (ASDR. For this survey, two 40-day expeditions were carried out in 2004. The first one occurred during the flooded season in June and July, and the second was during the peak of the dry season in October. Direct sightings were made through hiking along transects, navigation along water channels with a 30-hp speedboat, and gliding along flooded trails in the forest. New records of S. inustus were made in 11 different localities in ASDR. The study has confirmed the presence of the species in the Amanã area, carrying out the first records of the species in flooded forest habitats.

Estimation of current density distribution of PAFC by analysis of cell exhaust gas

Energy Technology Data Exchange (ETDEWEB)

Kato, S.; Seya, A. [Fuji Electric Co., Ltd., Ichihara-shi (Japan); Asano, A. [Fuji Electric Corporate, Ltd., Yokosuka-shi (Japan)

1996-12-31

To estimate distributions of Current densities, voltages, gas concentrations, etc., in phosphoric acid fuel cell (PAFC) stacks, is very important for getting fuel cells with higher quality. In this work, we leave developed a numerical simulation tool to map out the distribution in a PAFC stack. And especially to Study Current density distribution in the reaction area of the cell, we analyzed gas composition in several positions inside a gas outlet manifold of the PAFC stack. Comparing these measured data with calculated data, the current density distribution in a cell plane calculated by the simulation, was certified.

Statistical analysis of the distribution of critical current and the correlation of n value to the critical current of bent Bi2223 composite tape

International Nuclear Information System (INIS)

Ochiai, S; Matsubayashi, H; Okuda, H; Osamura, K; Otto, A; Malozemoff, A

2009-01-01

Distributions of local and overall critical currents and correlation of n value to the critical current of bent Bi2223 composite tape were studied from the statistical viewpoint. The data of the local and overall transport critical currents and n values of the Bi2223 composite tape specimens were collected experimentally for a wide range of bending strain (0-1.1%) by using the specimens, designed so as to characterize the local and overall critical currents and n values. The measured local and overall critical currents were analyzed with various types of Weibull distribution function. Which of the Weibull distribution functions is suitable for the description of the distribution of local and overall critical currents at each bending strain, and also how much the Weibull parameter values characterizing the distribution vary with bending strain, were revealed. Then we attempted to reproduce the overall critical current distribution and correlation of the overall n value to the overall critical current from the distribution of local critical currents and the correlation of the local n value to the local critical current by a Monte Carlo simulation. The measured average values of critical current and n value at each bending strain and the correlation of n value to critical current were reproduced well by the present simulation, while the distribution of critical current values was reproduced fairly well but not fully. The reason for this is discussed.

Methylmercury in fish from the South China Sea: geographical distribution and biomagnification.

Science.gov (United States)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-12-15

We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ(15)N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log10MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log10(MeHg) and δ(15)N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of Current Controllers for Distributed Power Generation Systems

DEFF Research Database (Denmark)

Timbus, Adrian; Liserre, Marco; Teodorescu, Remus

2009-01-01

This paper discusses the evaluation of different current controllers employed for grid-connected distributed power generation systems having variable input power, such as wind turbines and photovoltaic systems. The focus is mainly set on linear controllers such as proportional-integral, proportio......This paper discusses the evaluation of different current controllers employed for grid-connected distributed power generation systems having variable input power, such as wind turbines and photovoltaic systems. The focus is mainly set on linear controllers such as proportional......-integral, proportional-resonant, and deadbeat (DB) controllers. Additionally, an improved DB controller robust against grid impedance variation is also presented. Since the paper discusses the implementation of these controllers for grid-connected applications, their evaluation is made in three operating conditions....... First, in steady-state conditions, the contribution of controllers to the total harmonic distortion of the grid current is pursued. Further on, the behavior of controllers in the case of transient conditions like input power variations and grid voltage faults is also examined. Experimental results...

Geographic distribution and spatial differentiation in the color pattern of abdominal stripes of the Neotropical stingless bee Melipona quadrifasciata (Hymenoptera: Apidae

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Henrique Batalha-Filho

2009-06-01

Full Text Available Melipona quadrifasciata Lepeletier, 1836, regionally known as "mandaçaia", has been traditionally divided in two distinct subspecies: M. quadrifasciata anthidioides and M. quadrifasciata quadrifasciata. The main difference between the subspecies refers to the yellow metasomal stripes which are continuous in M. q. quadrifasciata and discontinuous in M. q. anthidioides. This study investigated the geographic differentiation in the metasomal stripes and characterized the restriction sites in the mtDNA of both chromatic types. Specimens from 198 localities were examined, and the variation observed in the pattern of stripes was grouped into distinct classes. The distribution pattern found in the present work agrees with the previously reported pattern: M. q. quadrifasciata inhabits the southern portion of the distribution, from Misiones, Argentina, southeastern Paraguay and Rio Grande do Sul to southern São Paulo, and M. q. anthidioides ranges from northeastern São Paulo to the northern Diamantina Plateau, Bahia, and westwards to the central portion of the Goiás state. It is documented for the first time the occurrence of two populations with continuous stripes inhabiting disjunct areas in relation to M. q. quadrifasciata - one in northern Minas Gerais and another in northeastern Bahia and Sergipe. The data of RFLP showed two restriction patterns, one present in M. q. quadrifasciata, and another in M. q. anthidioides and in populations with continuous metasomal stripes from northern Minas Gerais and northeastern Bahia and Sergipe. The observed patterns of geographic differentiation of M. quadrifasciata suggests the occurrence of repeated events of geographical isolation, followed by range expansion, that occurred probably during the cycles of climatic changes in the Pleistocene.

The structure, distribution, and biomass of the world's forests

Science.gov (United States)

Yude Pan; Richard A. Birdsey; Oliver L. Phillips; Robert B. Jackson

2013-01-01

Forests are the dominant terrestrial ecosystem on Earth. We review the environmental factors controlling their structure and global distribution and evaluate their current and future trajectory. Adaptations of trees to climate and resource gradients, coupled with disturbances and forest dynamics, create complex geographical patterns in forest assemblages and structures...

Effects of geographical extent on the determinants of woody plant diversity

DEFF Research Database (Denmark)

Wang, Zhiheng; Rahbek, Carsten; Fang, Jingyun

2012-01-01

the quantitative effects of geographical extent are rarely tested. Here, using distribution maps of 11,405 woody species found in China and associated environmental data to the domain, we investigated the influence of geographical extent on the determinants of species richness patterns. Our results revealed...

Epstein-Barr virus strains and variations: Geographic or disease-specific variants?

Science.gov (United States)

Neves, Marco; Marinho-Dias, Joana; Ribeiro, Joana; Sousa, Hugo

2017-03-01

The Epstein-Barr Virus (EBV) is associated with the development of several diseases, including infectious mononucleosis (IM), Burkitt's Lymphoma (BL), Nasopharyngeal Carcinoma, and other neoplasias. The publication of EBV genome 1984 led to several studies regarding the identification of different viral strains. Currently, EBV is divided into EBV type 1 (B95-8 strain) and EBV type 2 (AG876 strain), also known as type A and type B, which have been distinguished based upon genetic differences in the Epstein-Barr nuclear antigens (EBNAs) sequence. Several other EBV strains have been described in the past 10 years considering variations on EBV genome, and many have attempted to clarify if these variations are ethnic or geographically correlated, or if they are disease related. Indeed, there is an increasing interest to describe possible specific disease associations, with emphasis on different malignancies. These studies aim to clarify if these variations are ethnic or geographically correlated, or if they are disease related, thus being important to characterize the epidemiologic genetic distribution of EBV strains on our population. Here, we review the current knowledge on the different EBV strains and variants and its association with different diseases. J. Med. Virol. 89:373-387, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Hierarchical Distributed-Lag Models: Exploring Varying Geographic Scale and Magnitude in Associations Between the Built Environment and Health.

Science.gov (United States)

Baek, Jonggyu; Sanchez-Vaznaugh, Emma V; Sánchez, Brisa N

2016-03-15

It is well known that associations between features of the built environment and health depend on the geographic scale used to construct environmental attributes. In the built environment literature, it has long been argued that geographic scales may vary across study locations. However, this hypothesized variation has not been systematically examined due to a lack of available statistical methods. We propose a hierarchical distributed-lag model (HDLM) for estimating the underlying overall shape of food environment-health associations as a function of distance from locations of interest. This method enables indirect assessment of relevant geographic scales and captures area-level heterogeneity in the magnitudes of associations, along with relevant distances within areas. The proposed model was used to systematically examine area-level variation in the association between availability of convenience stores around schools and children's weights. For this case study, body mass index (weight kg)/height (m)2) z scores (BMIz) for 7th grade children collected via California's 2001-2009 FitnessGram testing program were linked to a commercial database that contained locations of food outlets statewide. Findings suggested that convenience store availability may influence BMIz only in some places and at varying distances from schools. Future research should examine localized environmental or policy differences that may explain the heterogeneity in convenience store-BMIz associations. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation.

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Anahí E Formoso

Full Text Available The Patagonian opossum (Lestodelphys halli, the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32 °S and ~49 °S. Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic "space" currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future.

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation

Science.gov (United States)

Formoso, Anahí E.; Martin, Gabriel M.; Teta, Pablo; Carbajo, Aníbal E.; Sauthier, Daniel E. Udrizar; Pardiñas, Ulyses F. J.

2015-01-01

The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32°S and ~49°S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic “space” currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future. PMID:26203650

The current distribution in Bi-2223/Ag HTS conductors: comparing Hall probe and magnetic knife

NARCIS (Netherlands)

Demencik, E.; Dhalle, Marc M.J.; ten Kate, Herman H.J.; Polak, M.

2006-01-01

We analyzed the current distribution in three Bi-2223/Ag tapes with different filament lay-out, comparing the results of magnetic knife and Hall probe experiments. Detailed knowledge of the current distribution can be useful for the diagnostics of HTS conductors. The lateral current distribution was

Current distribution in Cable-In-Conduit Conductors

International Nuclear Information System (INIS)

Ferri, M.A.

1994-05-01

A numerical study of the current distribution in Cable-In-Conduit Conductors (CICC's) experiencing linearly ramping transport currents and transverse magnetic fields was conducted for both infinitely long, periodic cables and finite length cables terminated in low resistance joints. The goal of the study was to gain insight into the phenomenon known as Ramp Rate Limitation, an as yet unexplained correspondence between maximum attainable current and the ramp time taken to reach that current in CICC superconducting magnets. A discrete geometric model of a 27 strand multiply twisted CICC was developed to effectively represent the flux linkages, mutual inductances, and resistive contact points between the strands of an experimentally tested cable. The results of the numerical study showed that for fully periodic cables, the current imbalances due to ramping magnetic fields and ramping transport currents are negligible in the range of experimentally explored operating conditions. For finite length, joint terminated cables, however, significant imbalances can exist. Unfortunately, quantitative results are limited by a lack of knowledge of the transverse resistance between strands in the joints. Nonetheless, general results are presented showing the dependency of the imbalance on cable length, ramp time, and joint resistance for both ramping transverse magnet fields and ramping transport currents. At the conclusion of the study, it is suggested that calculated current imbalances in a finite length cable could cause certain strands to prematurely ''quench'' -- become non-superconducting --thus leading to an instability for the entire cable. This numerically predicted ''current imbalance instability'' is compared to the experimentally observed Ramp Rate Limitation for the 27 strand CICC sample

The distribution and habitat preferences of the declining species Orobanche arenaria Borkh at the northern limit of its geographical range

Directory of Open Access Journals (Sweden)

Renata Piwowarczyk

2011-01-01

Full Text Available Three new sites of Orobanche arenaria were discovered during floristic investigations in the Wyżyna Małopolska upland in central Poland. The new localities are concentrated in the Ponidzie area (Garb Pińczowski ridge and Niecka Połaniecka basin and form the northern limit of the geographical range of O. arenaria. The paper presents information on the distribution of Orobanche arenaria in Poland, the abundance at the sites and habitats occupied by the species.

Field-emission from parabolic tips: Current distributions, the net current, and effective emission area

Science.gov (United States)

Biswas, Debabrata

2018-04-01

Field emission from nano-structured emitters primarily takes place from the tips. Using recent results on the variation of the enhancement factor around the apex [Biswas et al., Ultramicroscopy 185, 1-4 (2018)], analytical expressions for the surface distribution of net emitted electrons, as well as the total and normal energy distributions are derived in terms of the apex radius Ra and the local electric field at the apex Ea. Formulae for the net emitted current and effective emission area in terms of these quantities are also obtained.

Remote sensing research in geographic education: An alternative view

Science.gov (United States)

Wilson, H.; Cary, T. K.; Goward, S. N.

1981-01-01

It is noted that within many geography departments remote sensing is viewed as a mere technique a student should learn in order to carry out true geographic research. This view inhibits both students and faculty from investigation of remotely sensed data as a new source of geographic knowledge that may alter our understanding of the Earth. The tendency is for geographers to accept these new data and analysis techniques from engineers and mathematicians without questioning the accompanying premises. This black-box approach hinders geographic applications of the new remotely sensed data and limits the geographer's contribution to further development of remote sensing observation systems. It is suggested that geographers contribute to the development of remote sensing through pursuit of basic research. This research can be encouraged, particularly among students, by demonstrating the links between geographic theory and remotely sensed observations, encouraging a healthy skepticism concerning the current understanding of these data.

Geographic distribution of the tortoises and freshwater turtles of Colombia and their representation in the protected area network

International Nuclear Information System (INIS)

Forero Medina, German; Yusti Munoz, Ana Paola; Castano Mora, Olga V

2014-01-01

Colombia has a remarkable diversity of tortoises and freshwater turtles. However, a considerable portion of these species is threatened, and for others there is not enough information to make an adequate evaluation of their conservation status. This study is a first approximation to the quantitative evaluation of the geographic distribution of Colombia's non-marine chelonians. Based on records of occurrence for each species, we evaluated the geographic distribution using statistical models (maxent), hydrological basins, and the extent of occurrence and area of occupancy. Based on the presence data and the models, we studied the representation of each species in national natural parks (NNP), which correspond to the most rigorous conservation category of IUCN classification in Colombia, and other types of protected areas such as private reserves. We generated distribution models and estimated the area (km"2) for 25 out of 27 species in the country. This information will be valuable for updating and evaluating the threat categories at the national level. The areas with the highest species richness correspond to the riverine ecosystems of the Amazon and Orinoco River Basins and the Caribbean Region, particularly the Western Caribbean. This region is a top priority not only because of its richness but also because of the presence of endemics and its high level of threat. Only 56 % of the species have confirmed records within national parks. A greater portion could be present in these areas according to the statistical models, but only ten of those species would have more than 10 % of their ranges within a park's boundary. Although the resulting models have certain limitations due to the nature of the data and analyses, they can be a starting point for research on the occurrence of turtles in NNP. Endemic species are poorly represented in protected areas, both in NNP and in other categories. Thus, protected areas that can assure the persistence of their populations are

[Temporal variation and geographical distribution: congenital heart defects in the Comunitat Valenciana].

Science.gov (United States)

Cavero Carbonell, C; Zurriaga, O; Pérez Panadés, J; Barona Vilar, C; Martos Jiménez, C

2013-09-01

The objective of this study is to estimate the prevalence of congenital heart defects (CHD) in the Comunitat Valenciana (CV) in children less than one year old and identify whether there are temporal and geographic variations within this prevalence. The minimum basic data set from hospital discharge reports was used to select patients, who were born between 1999-2008, were less than one year old, and who lived in the CV with at least one hospital admission in which the primary diagnosis and/or any of the events were coded as CHD (codes 745-747 of the International Classification of Diseases 9th Revision Clinical Modification). The first hospital discharge report with CHD was selected, using the health card number to detect duplication. The prevalence and 95% confidence intervals were calculated, and the prevalence ratio (PR) and smoothed PR was obtained for each municipality to identify geographic patterns. In the period 1999-2008 there were 6.377 patients younger than one year with some CHD, representing the 43.2% of cases of congenital anomalies. The prevalence was 134.3 per 10.000 live births (95% CI: 131.1-137.6). There was a significant increase in the prevalence, from 115.8 in the 1999-2003 period to 149.5 in the 2004-2008 period. A higher risk was identified in the north of the CV, and in some municipalities of the province of Alicante, in the south. The observed increase in CHD agrees with the findings in other countries and it can be explained, at least in part, by improved diagnostic techniques. The geographic pattern identified requires a more detailed analysis that could explain the geographic variations found. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Correlation of geographic distributions of haptoglobin alleles with prevalence of multiple sclerosis (MS) - a narrative literature review.

Science.gov (United States)

Bamm, Vladimir V; Geist, Arielle M; Harauz, George

2017-02-01

We have proposed that the myelin damage observed in multiple sclerosis (MS) may be partly mediated through the long-term release and degradation of extracellular hemoglobin (Hb) and the products of its oxidative degradation [Cellular and Molecular Life Sciences, 71, 1789-1798, 2014]. The protein haptoglobin (Hpt) binds extracellular Hb as a first line of defense, and can serve as a vascular antioxidant. Humans have two different Hpt alleles: Hpt1 and Hpt2, giving either homozygous Hpt1-1 or Hpt2-2 phenotypes, or a heterozygous Hpt1-2 phenotype. We questioned whether those geographic regions with higher frequency of the Hpt2 allele (conversely, lower frequency of Hpt1 allele) would correlate with an increased incidence of MS, because different Hpt phenotypes will have variable anti-oxidative potentials in protecting myelin from damage inflicted by extracellular Hb and its degradation products. To test this hypothesis, we undertook a systematic analysis of the literature on reported geographic distributions of Hpt alleles to compare them with data reported in the World Health Organization Atlas of worldwide MS prevalence. We found the frequency of the Hpt1 allele to be low in European and North American countries with a high prevalence of MS, consistent with our hypothesis. However, this correlation was not observed in China and India, countries with the lowest Hpt1 frequencies, yet low reported prevalence of MS. Nevertheless, this work shows the need for continued refinement of geographic patterns of MS prevalence, including data on ethnic or racial origin, and for new clinical studies to probe the observed correlation and evaluate Hpt phenotype as a predictor of disease variability and progression, severity, and/or comorbidity with cardiovascular disorders.

[Prediction and spatial distribution of recruitment trees of natural secondary forest based on geographically weighted Poisson model].

Science.gov (United States)

Zhang, Ling Yu; Liu, Zhao Gang

2017-12-01

Based on the data collected from 108 permanent plots of the forest resources survey in Maoershan Experimental Forest Farm during 2004-2016, this study investigated the spatial distribution of recruitment trees in natural secondary forest by global Poisson regression and geographically weighted Poisson regression (GWPR) with four bandwidths of 2.5, 5, 10 and 15 km. The simulation effects of the 5 regressions and the factors influencing the recruitment trees in stands were analyzed, a description was given to the spatial autocorrelation of the regression residuals on global and local levels using Moran's I. The results showed that the spatial distribution of the number of natural secondary forest recruitment was significantly influenced by stands and topographic factors, especially average DBH. The GWPR model with small scale (2.5 km) had high accuracy of model fitting, a large range of model parameter estimates was generated, and the localized spatial distribution effect of the model parameters was obtained. The GWPR model at small scale (2.5 and 5 km) had produced a small range of model residuals, and the stability of the model was improved. The global spatial auto-correlation of the GWPR model residual at the small scale (2.5 km) was the lowe-st, and the local spatial auto-correlation was significantly reduced, in which an ideal spatial distribution pattern of small clusters with different observations was formed. The local model at small scale (2.5 km) was much better than the global model in the simulation effect on the spatial distribution of recruitment tree number.

Geographic Distribution of Ammonia-Oxidizing Archaea along the Kuril Islands in the Western Subarctic Pacific

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Hongmei Jing

2017-06-01

Full Text Available Community composition and abundance of ammonia-oxidizing archaea (AOA in the ocean were affected by different physicochemical conditions, but their responses to physical barriers (such as a chain of islands were largely unknown. In our study, geographic distribution of the AOA from the surface photic zone to the deep bathypelagic waters in the western subarctic Pacific adjacent to the Kuril Islands was investigated using pyrosequencing based on the ammonia monooxygenase subunit A (amoA gene. Genotypes of clusters A and B dominated in the upper euphotic zone and the deep waters, respectively. Quantitative PCR assays revealed that the occurrence and ammonia-oxidizing activity of ammonia-oxidizing archaea (AOA reached their maxima at the depth of 200 m, where a higher diversity and abundance of actively transcribed AOA was observed at the station located in the marginal sea exposed to more terrestrial input. Similar community composition of AOA observed at the two stations adjacent to the Kuril Islands maybe due to water exchange across the Bussol Strait. They distinct from the station located in the western subarctic gyre, where sub-cluster WCAII had a specific distribution in the surface water, and this sub-cluster seemed having a confined distribution in the western Pacific. Habitat-specific groupings of different WCB sub-clusters were observed reflecting the isolated microevolution existed in cluster WCB. The effect of the Kuril Islands on the phylogenetic composition of AOA between the Sea of Okhotsk and the western subarctic Pacific is not obvious, possibly because our sampling stations are near to the Bussol Strait, the main gateway through which water is exchanged between the Sea of Okhotsk and the Pacific. The vertical and horizontal distribution patterns of AOA communities among stations along the Kuril Islands were essentially determined by the in situ prevailing physicochemical gradients along the two dimensions.

Current distribution between petals in PF-FSJS sample

International Nuclear Information System (INIS)

Zani, L.

2003-01-01

6 Rogowski coils have been installed on each leg of each of the 12 petals in the PF-FSJS sample (poloidal field - full size joint sample) in order to diagnostic current. It appears that Rogowski signal seem reliable for current distribution analysis (Ampere's law is checked and reproducibility is assured) but there is some limitations for qualitative diagnostics. In the series of transparencies results are detailed for the PU1 position, for both leg and right legs and for various unique-angle shift (Δθ) configurations but only results for 0 < Δθ < -5 are consistent

Geomagnetic storms, the Dst ring-current myth and lognormal distributions

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Campbell, W.H.

1996-01-01

The definition of geomagnetic storms dates back to the turn of the century when researchers recognized the unique shape of the H-component field change upon averaging storms recorded at low latitude observatories. A generally accepted modeling of the storm field sources as a magnetospheric ring current was settled about 30 years ago at the start of space exploration and the discovery of the Van Allen belt of particles encircling the Earth. The Dst global 'ring-current' index of geomagnetic disturbances, formulated in that period, is still taken to be the definitive representation for geomagnetic storms. Dst indices, or data from many world observatories processed in a fashion paralleling the index, are used widely by researchers relying on the assumption of such a magnetospheric current-ring depiction. Recent in situ measurements by satellites passing through the ring-current region and computations with disturbed magnetosphere models show that the Dst storm is not solely a main-phase to decay-phase, growth to disintegration, of a massive current encircling the Earth. Although a ring current certainly exists during a storm, there are many other field contributions at the middle-and low-latitude observatories that are summed to show the 'storm' characteristic behavior in Dst at these observatories. One characteristic of the storm field form at middle and low latitudes is that Dst exhibits a lognormal distribution shape when plotted as the hourly value amplitude in each time range. Such distributions, common in nature, arise when there are many contributors to a measurement or when the measurement is a result of a connected series of statistical processes. The amplitude-time displays of Dst are thought to occur because the many time-series processes that are added to form Dst all have their own characteristic distribution in time. By transforming the Dst time display into the equivalent normal distribution, it is shown that a storm recovery can be predicted with

Natural Scales in Geographical Patterns

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Menezes, Telmo; Roth, Camille

2017-04-01

Human mobility is known to be distributed across several orders of magnitude of physical distances, which makes it generally difficult to endogenously find or define typical and meaningful scales. Relevant analyses, from movements to geographical partitions, seem to be relative to some ad-hoc scale, or no scale at all. Relying on geotagged data collected from photo-sharing social media, we apply community detection to movement networks constrained by increasing percentiles of the distance distribution. Using a simple parameter-free discontinuity detection algorithm, we discover clear phase transitions in the community partition space. The detection of these phases constitutes the first objective method of characterising endogenous, natural scales of human movement. Our study covers nine regions, ranging from cities to countries of various sizes and a transnational area. For all regions, the number of natural scales is remarkably low (2 or 3). Further, our results hint at scale-related behaviours rather than scale-related users. The partitions of the natural scales allow us to draw discrete multi-scale geographical boundaries, potentially capable of providing key insights in fields such as epidemiology or cultural contagion where the introduction of spatial boundaries is pivotal.

The effect of electrodeposition process parameters on the current density distribution in an electrochemical cell

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R. M. STEVANOVIC

2001-02-01

Full Text Available Cell voltage – current density dependences for a model electrochemical cell of fixed geometry were calculated for different electrolyte conductivities, Tafel slopes and cathodic exchange current densities. The ratio between the current density at the part of the cathode nearest to the anode and the one furthest away were taken as a measure for the estimation of the current density distribution. The calculations reveal that increasing the conductivity of the electrolyte, as well as increasing the cathodic Tafel slope should both improve the current density distribution. Also, the distribution should be better under total activation control or total diffusion control rather than at mixed activation-diffusion-Ohmic control of the deposition process. On the contrary, changes in the exchange current density should not affect it. These results, being in agreement with common knowledge about the influence of different parameters on the current distribution in an electrochemical cell, demonstrate that a quick estimation of the current distribution can be performed by a simple comparison of the current density at the point of the cathode closest to anode with that at furthest point.

[Geographic distribution and exposure population of drinking water with high concentration of arsenic in China].

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Zhang, L; Chen, C

1997-09-01

According to the data obtained from the "National Survey on Drinking Water Quality and Waterborne Diseases", the geographic distribution and exposure population of high arsenic drinking water were reported. From the data of more than 28,800 water samples, we found 9.02 million people drinking the water with As concentration of 0.030-0.049 mg/L, 3.34 million people having their water of 0.050-0.099 mg/L and 2.29 million people having water of > 0.1 mg/L. A total of 14.6 million people, about 1.5% of the surveyed population was exposed to As (> 0.030 mg/L) from drinking water. 80% of high-As-drinking water was groundwater. The situation of As in drinking water in provinces, autonomous regions and municipalities were listed. The locations of sampling site where water As exceeded the national standard for drinking water were illustrated.

Elevational distribution and extinction risk in birds.

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Rachel L White

Full Text Available Mountainous regions are hotspots of terrestrial biodiversity. Unlike islands, which have been the focus of extensive research on extinction dynamics, fewer studies have examined mountain ranges even though they face increasing threats from human pressures - notably habitat conversion and climate change. Limits to the taxonomic and geographical extent and resolution of previously available information have precluded an explicit assessment of the relative role of elevational distribution in determining extinction risk. We use a new global species-level avian database to quantify the influence of elevational distribution (range, maximum and midpoint on extinction risk in birds at the global scale. We also tested this relationship within biogeographic realms, higher taxonomic levels, and across phylogenetic contrasts. Potential confounding variables (i.e. phylogenetic, distributional, morphological, life history and niche breadth were also tested and controlled for. We show that the three measures of elevational distribution are strong negative predictors of avian extinction risk, with elevational range comparable and complementary to that of geographical range size. Extinction risk was also found to be positively associated with body weight, development and adult survival, but negatively associated with reproduction and niche breadth. The robust and consistent findings from this study demonstrate the importance of elevational distribution as a key driver of variation in extinction dynamics in birds. Our results also highlight elevational distribution as a missing criterion in current schemes for quantifying extinction risk and setting species conservation priorities in birds. Further research is recommended to test for generality across non-avian taxa, which will require an advance in our knowledge of species' current elevational ranges and increased efforts to digitise and centralise such data.

Monitoring potential geographical distribution of four wild bird species in China

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Dai, S.; Feng, D.; Xu, B.

2015-12-01

The outbreak of highly pathogenic avian influenza (HPAI) of the H5N1 subtype in wild birds and poultry have caught worldwide attention. To explore the association between wild bird migration and avian influenza virus transmission, we monitored potential geographical distribution of four wild bird species that might carry the avian influenza viruses in China. They are Bar-headed geese (Anser indicus), Ruddy Shelduck (Tadorna ferruginea), Whooper Swan (Cygnus cygnus) and Black-headed Gull (Larus ridibundus). They served as major reservoir of the avian influenza viruses. We used bird watching records with the precise latitude/longitude coordinates from January 2002 to August 2014, and environmental variables with a pixel resolution of 5 km × 5 km from 2002 to 2014. The study utilized maximum entropy (MaxEnt) model based on ecological niche model approaches, and got the following results: 1) MaxEnt model have good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.86-0.97; 2) The four wild bird species were estimated to concentrate in the North China Plain, the middle and lower region of the Yangtze River, Qinghai Lake, Tianshan Mountain and Tarim Basin, part of Tibet Plateau, and Hengduan Mountains; 3) Radiation and the minimum temperature were found to provide the most significant information. Our findings will help to understand the spread of avian influenza viruses by wild bird migration in China, which benefits for effective monitoring strategies and prevention measures.

[Analysis on geographic distribution of high blood pressure prevalence in children and adolescents aged 7-18 years in China, 2014].

Science.gov (United States)

Dong, Y H; Zou, Z Y; Wang, Z H; Wang, S; Yang, Z P; Chen, Y J; Ma, J

2017-07-10

Objective: To understand and evaluate the characteristics of geographic distribution of high blood pressure prevalence in children and adolescents aged 7-18 years in China in 2014, and provide evidence for the prevention of hypertension in children and adolescents. Methods: The data of 2014 Chinese National Surveys on Students Constitution and Health conducting 31 provinces (except Hong Kong, Macao and Taiwan) were collected. A total of 216 299 children and adolescents who had complete blood pressure records were selected as study subjects. The low, middle and high prevalence areas were identified according to their high blood pressure detection rates in the children and adolescents,7 % , to analyze the geographic distribution of high blood pressure prevalence in the children and adolescents. The environmental data in the capitals of 31 provinces in 2014 were collected to analyze the correlation between environmental factors and blood pressure Z score in the children and adolescents. Results: The average detection rates of high blood pressure was 6.4 % in 31 provinces (1.5 % -14.2 % ). The high prevalence areas were mainly distributed in the eastern China, especially the Circum-Bohai sea area, low prevalence areas were mainly distributed in the central and western areas of China and some provinces in the east. Correlation analysis results showed that the annual average temperature, annual average air humidity and local altitude were negatively correlated with blood pressure Z score, including diastolic and systolic blood pressure, in both boys and girls. The annual average sunshine time, PM(2.5) and PM(10) concentrations, content of SO(2) were positively correlated with blood pressure Z score in both boys and girls. Conclusions: There was a significant difference in high blood pressure of children and adolescents among 31 provinces. More attention should be paid to the children and adolescents living high prevalence area. And it is necessary to understand

Estimating the accuracy of geographical imputation

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Boscoe Francis P

2008-01-01

Full Text Available Abstract Background To reduce the number of non-geocoded cases researchers and organizations sometimes include cases geocoded to postal code centroids along with cases geocoded with the greater precision of a full street address. Some analysts then use the postal code to assign information to the cases from finer-level geographies such as a census tract. Assignment is commonly completed using either a postal centroid or by a geographical imputation method which assigns a location by using both the demographic characteristics of the case and the population characteristics of the postal delivery area. To date no systematic evaluation of geographical imputation methods ("geo-imputation" has been completed. The objective of this study was to determine the accuracy of census tract assignment using geo-imputation. Methods Using a large dataset of breast, prostate and colorectal cancer cases reported to the New Jersey Cancer Registry, we determined how often cases were assigned to the correct census tract using alternate strategies of demographic based geo-imputation, and using assignments obtained from postal code centroids. Assignment accuracy was measured by comparing the tract assigned with the tract originally identified from the full street address. Results Assigning cases to census tracts using the race/ethnicity population distribution within a postal code resulted in more correctly assigned cases than when using postal code centroids. The addition of age characteristics increased the match rates even further. Match rates were highly dependent on both the geographic distribution of race/ethnicity groups and population density. Conclusion Geo-imputation appears to offer some advantages and no serious drawbacks as compared with the alternative of assigning cases to census tracts based on postal code centroids. For a specific analysis, researchers will still need to consider the potential impact of geocoding quality on their results and evaluate

Interactive analysis of geographically distributed population imaging data collections over light-path data networks

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van Lew, Baldur; Botha, Charl P.; Milles, Julien R.; Vrooman, Henri A.; van de Giessen, Martijn; Lelieveldt, Boudewijn P. F.

2015-03-01

The cohort size required in epidemiological imaging genetics studies often mandates the pooling of data from multiple hospitals. Patient data, however, is subject to strict privacy protection regimes, and physical data storage may be legally restricted to a hospital network. To enable biomarker discovery, fast data access and interactive data exploration must be combined with high-performance computing resources, while respecting privacy regulations. We present a system using fast and inherently secure light-paths to access distributed data, thereby obviating the need for a central data repository. A secure private cloud computing framework facilitates interactive, computationally intensive exploration of this geographically distributed, privacy sensitive data. As a proof of concept, MRI brain imaging data hosted at two remote sites were processed in response to a user command at a third site. The system was able to automatically start virtual machines, run a selected processing pipeline and write results to a user accessible database, while keeping data locally stored in the hospitals. Individual tasks took approximately 50% longer compared to a locally hosted blade server but the cloud infrastructure reduced the total elapsed time by a factor of 40 using 70 virtual machines in the cloud. We demonstrated that the combination light-path and private cloud is a viable means of building an analysis infrastructure for secure data analysis. The system requires further work in the areas of error handling, load balancing and secure support of multiple users.

An assessment of geographical distribution of different plant functional types over North America simulated using the CLASS-CTEM modelling framework

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Shrestha, Rudra K.; Arora, Vivek K.; Melton, Joe R.; Sushama, Laxmi

2017-10-01

The performance of the competition module of the CLASS-CTEM (Canadian Land Surface Scheme and Canadian Terrestrial Ecosystem Model) modelling framework is assessed at 1° spatial resolution over North America by comparing the simulated geographical distribution of its plant functional types (PFTs) with two observation-based estimates. The model successfully reproduces the broad geographical distribution of trees, grasses and bare ground although limitations remain. In particular, compared to the two observation-based estimates, the simulated fractional vegetation coverage is lower in the arid southwest North American region and higher in the Arctic region. The lower-than-observed simulated vegetation coverage in the southwest region is attributed to lack of representation of shrubs in the model and plausible errors in the observation-based data sets. The observation-based data indicate vegetation fractional coverage of more than 60 % in this arid region, despite only 200-300 mm of precipitation that the region receives annually, and observation-based leaf area index (LAI) values in the region are lower than one. The higher-than-observed vegetation fractional coverage in the Arctic is likely due to the lack of representation of moss and lichen PFTs and also likely because of inadequate representation of permafrost in the model as a result of which the C3 grass PFT performs overly well in the region. The model generally reproduces the broad spatial distribution and the total area covered by the two primary tree PFTs (needleleaf evergreen trees, NDL-EVG; and broadleaf cold deciduous trees, BDL-DCD-CLD) reasonably well. The simulated fractional coverage of tree PFTs increases after the 1960s in response to the CO2 fertilization effect and climate warming. Differences between observed and simulated PFT coverages highlight model limitations and suggest that the inclusion of shrubs, and moss and lichen PFTs, and an adequate representation of permafrost will help improve

An overview of trends in distribution network planning: A movement towards smart planning

DEFF Research Database (Denmark)

You, Shi; Bindner, Henrik W.; Hu, Junjie

2014-01-01

Distribution network planning, historically known as a ‘predict and provide’ process, seeks to determine a set of optimal network solutions for supplying electric demands spatially distributed over a geographic area. Today, the rapid development and deployment of distributed generation and smart...... grid products (e.g., control, communication, and new economic measures) call for urgent improvements in distribution network planning to allow the utilities to proactively modernize their existing distribution grids. This paper reviews the current practices in this area and the emerging trends towards...

The current duration design for estimating the time to pregnancy distribution

DEFF Research Database (Denmark)

Gasbarra, Dario; Arjas, Elja; Vehtari, Aki

2015-01-01

This paper was inspired by the studies of Niels Keiding and co-authors on estimating the waiting time-to-pregnancy (TTP) distribution, and in particular on using the current duration design in that context. In this design, a cross-sectional sample of women is collected from those who are currently...... attempting to become pregnant, and then by recording from each the time she has been attempting. Our aim here is to study the identifiability and the estimation of the waiting time distribution on the basis of current duration data. The main difficulty in this stems from the fact that very short waiting...... times are only rarely selected into the sample of current durations, and this renders their estimation unstable. We introduce here a Bayesian method for this estimation problem, prove its asymptotic consistency, and compare the method to some variants of the non-parametric maximum likelihood estimators...

Present, past and future of the European rock fern Asplenium fontanum: combining distribution modelling and population genetics to study the effect of climate change on geographic range and genetic diversity.

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Bystriakova, Nadia; Ansell, Stephen W; Russell, Stephen J; Grundmann, Michael; Vogel, Johannes C; Schneider, Harald

2014-02-01

Climate change is expected to alter the geographic range of many plant species dramatically. Predicting this response will be critical to managing the conservation of plant resources and the effects of invasive species. The aim of this study was to predict the response of temperate homosporous ferns to climate change. Genetic diversity and changes in distribution range were inferred for the diploid rock fern Asplenium fontanum along a South-North transect, extending from its putative last glacial maximum (LGM) refugia in southern France towards southern Germany and eastern-central France. This study reconciles observations from distribution models and phylogeographic analyses derived from plastid and nuclear diversity. Genetic diversity distribution and niche modelling propose that genetic diversity accumulates in the LGM climate refugium in southern France with the formation of a diversity gradient reflecting a slow, post-LGM range expansion towards the current distribution range. Evidence supports the fern's preference for outcrossing, contradicting the expectation that homosporous ferns would populate new sites by single-spore colonization. Prediction of climate and distribution range change suggests that a dramatic loss of range and genetic diversity in this fern is possible. The observed migration is best described by the phalanx expansion model. The results suggest that homosporous ferns reproducing preferentially by outcrossing accumulate genetic diversity primarily in LGM climate refugia and may be threatened if these areas disappear due to global climate change.

On the Electromagnetic Momentum of Static Charge and Steady Current Distributions

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Gsponer, Andre

2007-01-01

Faraday's and Furry's formulae for the electromagnetic momentum of static charge distributions combined with steady electric current distributions are generalized in order to obtain full agreement with Poynting's formula in the case where all fields are of class C[superscript 1], i.e., continuous and continuously differentiable, and the…

Geographic variation in genetic and demographic performance: new insights from an old biogeographical paradigm.

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Pironon, Samuel; Papuga, Guillaume; Villellas, Jesús; Angert, Amy L; García, María B; Thompson, John D

2017-11-01

The 'centre-periphery hypothesis' (CPH) is a long-standing postulate in ecology that states that genetic variation and demographic performance of a species decrease from the centre to the edge of its geographic range. This hypothesis is based on an assumed concordance between geographical peripherality and ecological marginality such that environmental conditions become harsher towards the limits of a species range. In this way, the CPH sets the stage for understanding the causes of distribution limits. To date, no study has examined conjointly the consistency of these postulates. In an extensive literature review we discuss the birth and development of the CPH and provide an assessment of the CPH by reviewing 248 empirical studies in the context of three main themes. First, a decrease in species occurrence towards their range limits was observed in 81% of studies, while only 51% demonstrated reduced abundance of individuals. A decline in genetic variation, increased differentiation among populations and higher rates of inbreeding were demonstrated by roughly one in two studies (47, 45 and 48%, respectively). However, demographic rates, size and population performance less often followed CPH expectations (20-30% of studies). We highlight the impact of important methodological, taxonomic, and biogeographical biases on such validation rates. Second, we found that geographic and ecological marginality gradients are not systematically concordant, which casts doubt on the reliability of a main assumption of the CPH. Finally, we attempt to disentangle the relative contribution of geographical, ecological and historical processes on the spatial distribution of genetic and demographic parameters. While ecological marginality gradients explain variation in species' demographic performance better than geographic gradients, contemporary and historical factors may contribute interactively to spatial patterns of genetic variation. We thereby propose a framework that integrates

Leishmania in the Old World: 1. The geographical and hostal distribution of L. major zymodemes.

Science.gov (United States)

Le Blancq, S M; Schnur, L F; Peters, W

1986-01-01

135 stocks of Leishmania major from man, reservoir hosts and sandflies were characterized using thin-layer starch-gel electrophoresis of 13 enzymes: MDH, 6PGD, GD, SOD, ASAT, ALAT, PK, PGM, ES, NH, PEPD, MPI, GPI. Homogeneity in this species was demonstrated by identical electrophoretic mobilities in nine enzymes. Polymorphism in four enzymes: 6PGD, GPI, PEPD, ES, gave six zymodemes among the collection. Stocks from sandflies and several species of burrowing rodents were indistinguishable from those from man in the same areas. Stocks of Leishmania from North-West India were identified as L. major. In some foci the distribution of zymodemes has some correlation with the presence of particular rodent reservoir hosts. The enzymic homogeneity of L. major throughout its geographical and host range appears to be correlated with the close association between L. major and sandflies of the subgenus Phlebotomus. The status of L. major as a distinct species is supported.

Geographically isolated wetlands: Rethinking a misnomer

Science.gov (United States)

Mushet, David M.; Calhoun, Aram J.K.; Alexander, Laurie C.; Cohen, Matthew J.; DeKeyser, Edward S.; Fowler, Laurie G.; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Walls, Susan

2015-01-01

We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective of regulatory and management information needs, (3) implies wetlands so described are in some way “isolated,” an often incorrect implication, (4) is inconsistent with more broadly used and accepted concepts of “geographic isolation,” and (5) has injected unnecessary confusion into scientific investigations and discussions. Instead, we suggest other wetland classification systems offer more informative alternatives. For example, hydrogeomorphic (HGM) classes based on well-established scientific definitions account for wetland functional diversity thereby facilitating explorations into questions of connectivity without an a priori designation of “isolation.” Additionally, an HGM-type approach could be used in combination with terms reflective of current regulatory or policymaking needs. For those rare cases in which the condition of being surrounded by uplands is the relevant distinguishing characteristic, use of terminology that does not unnecessarily imply isolation (e.g., “upland embedded wetlands”) would help alleviate much confusion caused by the “geographically isolated wetlands” misnomer.

The impact of travel time on geographic distribution of dialysis patients.

Science.gov (United States)

Kashima, Saori; Matsumoto, Masatoshi; Ogawa, Takahiko; Eboshida, Akira; Takeuchi, Keisuke

2012-01-01

The geographic disparity of prevalence rates among dialysis patients is unclear. We evaluate the association between travel time to dialysis facilities and prevalence rates of dialysis patients living in 1,867 census areas of Hiroshima, Japan. Furthermore, we study the effects of geographic features (mainland or island) on the prevalence rates and assess if these effects modify the association between travel time and prevalence. The study subjects were all 7,374 people that were certified as the "renal disabled" by local governments in 2011. The travel time from each patient to the nearest available dialysis facility was calculated by incorporating both travel time and the capacity of all 98 facilities. The effect of travel time on the age- and sex-adjusted standard prevalence rate (SPR) and 95% confidence intervals (CIs) at each census area was evaluated in two-level Poisson regression models with 1,867 census areas (level 1) nested within 35 towns or cities (level 2). The results were adjusted for area-based parameters of socioeconomic status, urbanity, and land type. Furthermore, the SPR of dialysis patients was calculated in each specific subgroup of population for travel time, land type, and combination of land type and travel time. In the regression analysis, SPR decreased by 5.2% (95% CI: -7.9--2.3) per 10-min increase in travel time even after adjusting for potential confounders. The effect of travel time on prevalence was different in the mainland and island groups. There was no travel time-dependent SPR disparity on the islands. The SPR among remote residents (>30 min from facilities) in the mainland was lower (0.77, 95% CI: 0.71-0.85) than that of closer residents (≤ 30 min; 0.95, 95% CI: 0.92-0.97). The prevalence of dialysis patients was lower among remote residents. Geographic difficulties for commuting seem to decrease the prevalence rate.

Inferring geographic isolation of wolverines in California using historical DNA

Science.gov (United States)

Michael K. Schwartz; Keith B. Aubry; Kevin S. McKelvey; Kristine L. Pilgrim; Jeffrey P. Copeland; John R. Squires; Robert M. Inman; Samantha M. Wisely; Leonard F. Ruggiero

2007-01-01

Delineating a species' geographic range using the spatial distribution of museum specimens or even contemporary detection-non-detection data can be difficult. This is particularly true at the periphery of a species range where species' distributions are often disjunct. Wolverines (Gulo gulo) are wide-ranging mammals with discontinuous and...

Effects of polar field-aligned currents on the distribution of the electric field and current in the middle and low latitudes ionosphere

International Nuclear Information System (INIS)

Maekawa, Koichiro

1978-01-01

According to the analysis of the magnetic records from the Triad satellite, it has been found that there are two regions of the field-aligned current of magnetospheric origin along the auroral oval; Region 1 in higher latitude and Region 2 in lower latitude. These currents seem to have important effect on the distribution of electric field and current in the ionosphere, in addition to the Sq electric field and current of ionospheric origin. The global current systems generated by the field-aligned current were calculated, using some simplified ionospheric models. The effect of the field-aligned current on the distribution of electric field and current of the ionosphere at middle and low latitudes was investigated. (Yoshimori, M.)

Accidental hazardous material releases with human impacts in the United States: exploration of geographical distribution and temporal trends.

Science.gov (United States)

Sengul, Hatice; Santella, Nicholas; Steinberg, Laura J; Chermak, Christina

2010-09-01

To investigate the circumstances and geographic and temporal distributions of hazardous material releases and resulting human impacts in the United States. Releases with fatalities, injuries, and evacuations were identified from reports to the National Response Center between 1990 and 2008, correcting for data quality issues identified in previous studies. From more than 550,000 reports, 861 deaths, 16,348 injuries and 741,427 evacuations were identified. Injuries from releases of chemicals at fixed facilities and natural gas from pipelines have decreased whereas evacuations from petroleum releases at fixed facilities have increased. Results confirm recent advances in chemical and pipeline safety and suggest directions for further improvement including targeted training and inspections and adoption of inherently safer design principles.

Calculation of the self-consistent current distribution and coupling of an RF antenna array

International Nuclear Information System (INIS)

Ballico, M.; Puri, S.

1993-10-01

A self-consistent calculation of the antenna current distribution and fields in an axisymmetric cylindrical geometry for the ICRH antenna-plasma coupling problem is presented. Several features distinguish this calculation from other codes presently available. 1. Variational form: The formulation of the self consistent antenna current problem in a variational form allows good convergence and stability of the algorithm. 2. Multiple straps: Allows modelling of (a) the current distribution across the width of the strap (by dividing it up into sub straps) (b) side limiters and septum (c) antenna cross-coupling. 3. Analytic calculation of the antenna field and calculation of the antenna self-consistent current distribution, (given the surface impedance matrix) gives rapid calculation. 4. Framed for parallel computation on several different parallel architectures (as well as serial) gives a large speed improvement to the user. Results are presented for both Alfven wave heating and current drive antenna arrays, showing the optimal coupling to be achieved for toroidal mode numbers 8< n<10 for typical ASDEX upgrade plasmas. Simulations of the ASDEX upgrade antenna show the importance of the current distribution across the antenna and of image currents flowing in the side limiters, and an analysis of a proposed asymmetric ITER antenna is presented. (orig.)

Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

Science.gov (United States)

Ramasindrazana, Beza; Dellagi, Koussay; Lagadec, Erwan; Randrianarivelojosia, Milijaona; Goodman, Steven M; Tortosa, Pablo

2016-01-01

We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae); a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae) embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae), Otomops madagascariensis (Molossidae), and Paratriaenops furculus (Hipposideridae). We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

Directory of Open Access Journals (Sweden)

Beza Ramasindrazana

Full Text Available We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae; a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae, Otomops madagascariensis (Molossidae, and Paratriaenops furculus (Hipposideridae. We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

Bounding species distribution models

Directory of Open Access Journals (Sweden)

Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

2011-10-01

Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

Bounding Species Distribution Models

Science.gov (United States)

Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

2011-01-01

Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

Distribution of local critical current along sample length and its relation to overall current in a long Bi2223/Ag superconducting composite tape

International Nuclear Information System (INIS)

Ochiai, S; Doko, D; Okuda, H; Oh, S S; Ha, D W

2006-01-01

The distribution of the local critical current and the n-value along the sample length and its relation to the overall critical current were studied experimentally and analytically for the bent multifilamentary Bi2223/Ag/Ag-Mg alloy superconducting composite tape. Then, based on the results, it was attempted to simulate on a computer the dependence of the critical current on the sample length. The main results are summarized as follows. The experimentally observed relation of the distributed local critical current and n-value to the overall critical current was described comprehensively with a simple voltage summation model, in which the sample was regarded as a one-dimensional series circuit. The sample length dependence of the critical current was reproduced on the computer by a Monte Carlo simulation incorporating the voltage summation model and the regression analysis results for the local critical current distribution and the relation of the n-value to the critical current

Geographic proximity to specialized pediatric neurosurgical care in the contiguous United States.

Science.gov (United States)

Ahmed, Abdul-Kareem; Duhaime, Ann-Christine; Smith, Timothy R

2018-04-01

OBJECTIVE Absent from an analysis of supply is consideration of the geographic distribution of pediatric neurosurgeons. Several patient socioeconomic metrics are known to be associated with outcome in pediatric neurosurgical diseases, such as hydrocephalus. The purpose of this study was to determine current geographic proximity to pediatric neurosurgical care using professional society databases. This study also sought to establish how socioeconomic factors are related to distance to care, using federal government-collected data. METHODS A list of currently practicing American Board of Pediatric Neurological Surgery (ABPNS)-certified neurosurgeons was compiled (ABPNS group). A separate list of practicing members of the Joint Pediatric Section (JPS) of the American Association of Neurological Surgeons/Congress of Neurological Surgeons was prepared (JPS group). Current primary practice locations were collected from each professional society database for each ABPNS or JPS neurosurgeon and were charted using ArcGIS mapping software (ESRI, version 10.3) on a United States Census Bureau map. The straight distance from the centroid of each zip code tabulation area (ZCTA) to the nearest neurosurgeon was determined by group type of neurosurgeon (ABPNS vs ABPNS + JPS). ZCTA-level data on demographic and socioeconomic factors were acquired from the American Community Survey, including data in children and young adults (0-18 or 0-24 years old) and the general population. These data were compared by distance to care and by groups of neurosurgeons (Pearson's chi-square analysis; the threshold of significance was set at 0.05). RESULTS Three hundred fifty-five practicing neurosurgeons providing pediatric care were located, of whom 215 surgeons were certified by the ABPNS and 140 were JPS members only. The analysis showed that 1 pediatric neurosurgeon is in practice for every 289,799 persons up to the age of 24 years. The average distance between a ZCTA and the nearest pediatric

Distributed Secondary Control for DC Microgrid Applications with Enhanced Current Sharing Accuracy

DEFF Research Database (Denmark)

Lu, Xiaonan; Guerrero, Josep M.; Sun, Kai

2013-01-01

With the consideration of line resistances in a dc microgrid, the current sharing accuracy is lowered down, since the dc output voltage cannot be exactly the same for different interfacing converters. Meanwhile, the dc bus voltage deviation is involved by using droop control. In this paper...... control diagram is accomplished and the requirement of distributed configuration in a microgrid is satisfied. The experimental validation based on a 2×2.2 kW prototype was implemented to demonstrate the proposed approach......., a distributed secondary control method is proposed. Droop control is employed as the primary control method for load current sharing. Meanwhile, the dc output voltage and current in each module is transferred to the others by the low bandwidth communication (LBC) network. Average voltage and current controllers...

Geographic variation in the advertisement calls of Hyla eximia and its possible explanations.

Science.gov (United States)

Rodríguez-Tejeda, Ruth E; Méndez-Cárdenas, María Guadalupe; Islas-Villanueva, Valentina; Macías Garcia, Constantino

2014-01-01

Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproductive character displacement (RCD). We investigated whether variation in the advertisement call of the mountain treefrog (Hyla eximia) is linked to geographic distribution with respect to major Mexican river basins (Panuco, Lerma, Balsas and Magdalena), or to coexistence with its sister (the canyon treefrog, Hyla arenicolor) or another related species (the dwarf treefrog, Tlalocohyla smithii). We also evaluated whether call divergence across the main river basins could be linked to genetic structure. We found that the multidimensional acoustic space of calls from two basins where H. eximia currently interacts with T. smithii, was different from the acoustic space of calls from H. eximia elsewhere. Individuals from these two basins were also distinguishable from the rest by both the phylogeny inferred from mitochondrial sequences, and the genetic structure inferred from nuclear markers. The discordant divergence of H. eximia advertisement calls in the two separate basins where its geographic range overlaps that of T. smithii can be interpreted as the result of two independent events of RCD, presumably as a consequence of acoustic interference in the breeding choruses, although more data are required to evaluate this possibility.

Geographic variation in the advertisement calls of Hyla eximia and its possible explanations

Directory of Open Access Journals (Sweden)

Ruth E. Rodríguez-Tejeda

2014-06-01

Full Text Available Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproductive character displacement (RCD. We investigated whether variation in the advertisement call of the mountain treefrog (Hyla eximia is linked to geographic distribution with respect to major Mexican river basins (Panuco, Lerma, Balsas and Magdalena, or to coexistence with its sister (the canyon treefrog, Hyla arenicolor or another related species (the dwarf treefrog, Tlalocohyla smithii. We also evaluated whether call divergence across the main river basins could be linked to genetic structure. We found that the multidimensional acoustic space of calls from two basins where H. eximia currently interacts with T. smithii, was different from the acoustic space of calls from H. eximia elsewhere. Individuals from these two basins were also distinguishable from the rest by both the phylogeny inferred from mitochondrial sequences, and the genetic structure inferred from nuclear markers. The discordant divergence of H. eximia advertisement calls in the two separate basins where its geographic range overlaps that of T. smithii can be interpreted as the result of two independent events of RCD, presumably as a consequence of acoustic interference in the breeding choruses, although more data are required to evaluate this possibility.

On Optimal Geographical Caching in Heterogeneous Cellular Networks

NARCIS (Netherlands)

Serbetci, Berksan; Goseling, Jasper

2017-01-01

In this work we investigate optimal geographical caching in heterogeneous cellular networks where different types of base stations (BSs) have different cache capacities. Users request files from a content library according to a known probability distribution. The performance metric is the total hit

No Geographic Correlation between Lyme Disease and Death Due to 4 Neurodegenerative Disorders, United States, 2001-2010.

Science.gov (United States)

Forrester, Joseph D; Kugeler, Kiersten J; Perea, Anna E; Pastula, Daniel M; Mead, Paul S

2015-11-01

Associations between Lyme disease and certain neurodegenerative diseases have been proposed, but supportive evidence for an association is lacking. Similar geographic distributions would be expected if 2 conditions were etiologically linked. Thus, we compared the distribution of Lyme disease cases in the United States with the distributions of deaths due to Alzheimer disease, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and Parkinson disease; no geographic correlations were identified. Lyme disease incidence per US state was not correlated with rates of death due to ALS, MS, or Parkinson disease; however, an inverse correlation was detected between Lyme disease and Alzheimer disease. The absence of a positive correlation between the geographic distribution of Lyme disease and the distribution of deaths due to Alzheimer disease, ALS, MS, and Parkinson disease provides further evidence that Lyme disease is not associated with the development of these neurodegenerative conditions.

The National Geographic Names Data Base: Phase II instructions

Science.gov (United States)

Orth, Donald J.; Payne, Roger L.

1987-01-01

The Geographic Names Information System is a computer-based information system developed to meet major national needs by providing information for named entities in the United States, its territories, and outlying areas. The National Geographic Names Data Base, a component of the Geographic Names Information System, currently contains most names and associated information recorded on the 1:24,000-scale (or largest scale available) topographic maps of the U.S. Geological Survey. The work involved in this initial compilation of names shown on the topographic-map series, and the development and editing of the National Geographic Names Data Base, is referred to as Phase I. Optimal use and effectiveness of an automated names system require that the names of features

Development of hardwood seed zones for Tennessee using a geographic information system

Science.gov (United States)

Post, L.S.; Schlarbaum, S.E.; Van Manen, F.; Cecich, R.A.; Saxton, A.M.; Schneider, J.F.

2003-01-01

For species that have no or limited information on genetic variation and adaptability to nonnative sites, there is a need for seed collection guidelines based on biological, climatological, and/or geographical criteria. Twenty-eight hardwood species are currently grown for reforestation purposes at the East Tennessee State Nursery. The majority of these species have had no genetic testing to define guidelines for seed collection location and can be distributed to sites that have a very different environment than that of seed origin(s). Poor survival and/or growth may result if seedlings are not adapted to environmental conditions at the planting location. To address this problem, 30 yr of Tennessee county precipitation and minimum temperature data were analyzed and grouped using a centroid hierarchical cluster analysis. The weather data and elevational data were entered into a Geographic Information System (GIS) and separately layered over Bailey's Ecoregions to develop a seed zone system for Tennessee. The seed zones can be used as a practical guideline for collecting seeds to ensure that the resulting seedlings will be adapted to planting environments.

Fauna and Geographical Distribution of Scorpions in Ilam Province, South Western Iran.

Science.gov (United States)

Sharifinia, Narges; Gowhari, Iman; Hoseiny-Rad, Manijeh; Aivazi, Ali Ashraf

2017-06-01

Scorpions' stings and their own mortalities place them among the most important health and medical problems. The dreadful features and especially their poisonous stings are considered a major cause of human stress and abhorrence/phobia. The current study aimed to study the scorpion fauna of Ilam Province, south western Iran in order to manage scorpionism related problems. In this field-laboratory investigation during March 2014 to February 2015, different parts of Ilam Province were surveyed. Nine sampling parts were selected based on geographical situation, scorpionism reports, weather, flora, and local data. Capturing scorpion was done employing a black light, and a long forceps from dusk to midnight. The collected scorpions were placed to 70% ethyl alcohol. All specimens were determined based on the valid taxonomic keys, furthermore their sexes were studied. Out of the 391 collected scorpions, 11 species were identified as follows: Hottentotta saulcyi , Mesobuthus eupeus , Compsobuthus matthiesseni , Razianus zarudnyi , Hemiscorpius lepturus , Androctonus crassicauda , Orthochirus iranus , Odontobuthus bidentatus , Buthacus macrocentrus , Scorpio maurus , and Polisius persicus . Eleven species of Buthidae, Scorpionidae and Hemiscorpiidae families from high risk areas were identified. Despite the low surface of the province, such different species reveals a diverse scorpion fauna that, in turn, shows good and suitable habits of scorpions, as considered by health staff.

The pollutants from livestock and poultry farming in China-geographic distribution and drivers.

Science.gov (United States)

Gan, Ling; Hu, Xisheng

2016-05-01

Livestock and poultry farming is a major source of agricultural pollution. However, our knowledge of the constraining factors of the geographic distribution of pollutants from livestock and poultry farming is still limited. In this study, using the optimized pollutant generation coefficients, we estimated the annual pollutant productions of eight livestock and poultry species at the provincial level in 2005 and 2013 and their growth rates during the study period in China; using canonical correlation analysis, we also explored the association between the eight pollutant measurements as dependent variables and 14 factors (including resource endowment, developmental level, and economic structure factors) as independent variables. Results indicate that there exist spatial disparity in the distribution of pollutants from livestock and poultry farming across regions, with provinces in the Huang-Huai-Hai region and the southwestern region accounting for approximately 50 % of the total productions in the nation. Cattle, pig, and poultry constitute the primary pollution sources in terms of livestock and poultry farming not only at the national level but also at the province level. While the species constitute and their respective growth rates of the pollutants can be also characterized by spatial disparity across regions, canonical correlation analysis shows that the observed regional patterns of the pollutants can be largely explained by the resource endowment factors (positive effects) and the developmental level factors (negative effects). In addition, we found that the development of livestock and poultry farming is negatively associated with the growing rate of both the resource endowment and the socioeconomic factors. This indicates that there exist different driving patterns in the gross and increment of the pollutant productions. Our research has significant implications for the appropriate environmental protection policy formulation and implementation in livestock

Model Checking Geographically Distributed Interlocking Systems Using UMC

DEFF Research Database (Denmark)

Fantechi, Alessandro; Haxthausen, Anne Elisabeth; Nielsen, Michel Bøje Randahl

2017-01-01

the relevant distributed protocols. By doing that we obey the safety guidelines of the railway signalling domain, that require formal methods to support the certification of such products. We also show how formal modelling can help designing alternative distributed solutions, while maintaining adherence...

Geographic distribution of habitat, development, and population growth rates of the Asian citrus psyllid, Diaphorina citri, in Mexico.

Science.gov (United States)

López-Collado, José; Isabel López-Arroyo, J; Robles-García, Pedro L; Márquez-Santos, Magdalena

2013-01-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an introduced pest in Mexico and a vector of huanglongbing, a lethal citrus disease. Estimations of the habitat distribution and population growth rates of D. citri are required to establish regional and areawide management strategies and can be used as a pest risk analysis tools. In this study, the habitat distribution of D. citri in Mexico was computed with MaxEnt, an inductive, machine-learning program that uses bioclimatic layers and point location data. Geographic distributions of development and population growth rates were determined by fitting a temperature-dependent, nonlinear model and projecting the rates over the target area, using the annual mean temperature as the predictor variable. The results showed that the most suitable regions for habitat of D. citri comprise the Gulf of Mexico states, Yucatán Peninsula, and areas scattered throughout the Pacific coastal states. Less suitable areas occurred in northern and central states. The most important predictor variables were related to temperature. Development and growth rates had a distribution wider than habitat, reaching some of the northern states of México. Habitat, development, and population growth rates were correlated to each other and with the citrus producing area. These relationships indicated that citrus producing states are within the most suitable regions for the occurrence, development, and population growth of D. citri, therefore increasing the risk of huanglongbing dispersion.

Polarized parton distributions from charged-current deep-inelastic scattering

International Nuclear Information System (INIS)

Ridolfi, G

2003-01-01

We investigate the capabilities of a neutrino factory in the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments, with special attention to the accuracy of this kind of measurements. We show that a neutrino factory would allow to distinguish between different theoretical scenarios for the proton spin structure

Current distribution evaluation of dye-sensitized solar cell using HTS-SQUID-based magnetic measurement system

Energy Technology Data Exchange (ETDEWEB)

Sakai, Kenji, E-mail: Sakai-k@okayama-u.ac.jp; Tanaka, Kohei; Kiwa, Toshihiko; Tsukada, Keiji

2016-11-15

Highlights: • Current distribution and direction of dye-sensitized solar cell (DSSC) was measured. • Electrical current flowing in the indium tin oxide (ITO) glass substrate was uniform. • The distribution of electrical current depended on I–V characteristic. • Current direction changed when the performance of DSSC is low. - Abstract: The current flowing inside a dye-sensitized solar cell (DSSC) was measured using a high-temperature superconductor superconducting quantum interference device (HTS-SQUID)-based magnetic measurement system. Further, a new evaluation method of the DSSC, which is difficult to measure using the conventional method, was investigated to improve the characteristics of the DSSC. The tangential components of the magnetic field generated from the DSSC were measured using two HTS-SQUIDs, and the intensity and direction related to the electrical current were obtained by the measured magnetic field. The DSSCs prepared with different dyes and catalytic substances showed different current-intensity mapping. The current direction was different for the DSSC with low performance. In addition, the current flowing in the ITO layer of the ITO glass substrate was also measured and the results confirmed that it had uniform distribution. These results show that the current mapping and the direction of the electrical current depend on the internal factors of the DSSC, and the detection of the magnetic field distribution generated from it is expected to lead to its new evaluation method.

An emendation of the generic diagnosis of the monotypic Glanitaenia (Cestoda: Proteocephalidae), with notes on the geographical distribution of G-osculata, a parasite of invasive wels catfish

Czech Academy of Sciences Publication Activity Database

de Chambrier, A.; Scholz, Tomáš

2016-01-01

Roč. 123, č. 1 (2016), s. 1-9 ISSN 0035-418X R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Cestoda * Glanitaenia osculata * morphology * redescription * freshwater fish * geographical distribution * Europe Subject RIV: EG - Zoology Impact factor: 0.380, year: 2016

[Geographic data for Neotropical bats (Chiroptera)].

Science.gov (United States)

Noguera-Urbano, Elkin A; Escalante, Tania

2014-03-01

The global effort to digitize biodiversity occurrence data from collections, museums and other institutions has stimulated the development of important tools to improve the knowledge and conservation of biodiversity. The Global Biodiversity Information Facility (GBIF) enables and opens access to biodiversity data of 321 million of records, from 379 host institutions. Neotropical bats are a highly diverse and specialized group, and the geographic information about them is increasing since few years ago, but there are a few reports about this topic. The aim of this study was to analyze the number of digital records in GBIF of Neotropical bats with distribution in 21 American countries, evaluating their nomenclatural and geographical consistence at scale of country. Moreover, we evaluated the gaps of information on 1 degrees latitude x 1 degrees longitude grids cells. There were over 1/2 million records, but 58% of them have no latitude and longitude data; and 52% full fit nomenclatural and geographic evaluation. We estimated that there are no records in 54% of the analyzed area; the principal gaps are in biodiversity hotspots like the Colombian and Brazilian Amazonia and Southern Venezuela. In conclusion, our study suggests that available data on GBIF have nomenclatural and geographic biases. GBIF data represent partially the bat species richness and the main gaps in information are in South America.

Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV.

Science.gov (United States)

Barros, Juliana Helena S; Xavier, Samanta Cristina C; Bilac, Daniele; Lima, Valdirene Santos; Dario, Maria Augusta; Jansen, Ana Maria

2017-08-01

Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species. Copyright © 2017. Published by Elsevier B.V.

Geographical Simulation and Optimization System (GeoSOS and Its Application in the Analysis of Geographic National Conditions

Directory of Open Access Journals (Sweden)

LI Xia

2017-10-01

Full Text Available Since the Chinese first survey on geographic national conditions has completed, an urgent need is to analyze these geographical data, such as mining of spatial distribution patterns, land use transition rules, development trends. The analysis is crucial for extracting the knowledge from these big data about geographic national conditions. The remote sensing interpretation data and land use/cover data generated by these geographic national conditions monitoring projects are the basic data sources for a variety of research and applications in terms of land use change detection, urban dynamic analysis, and urban/land use planning. The information can be used for assisting in the coordination of land resource use and decision making for urban and rural development, ecological environment protection and other issues that depends on spatial intelligent decisions. We proposed the theoretical framework of geographical simulation and optimization system (GeoSOS, which coupled geographic process simulation/prediction and spatial optimization, provides powerful theoretical support and practical tools for above researches. This paper develops the extension of GeoSOS software-GeoSOS for ArcGIS, which is an ArcGIS Add-In runs on ArcGIS platform for facilitating the above analyses. We take the urban expansion and ecological protection research in rapid urbanization area as an example, use the software to tackle a series of urbanization issues in the study area. The simulation results show that the predicted land development intensity of Guangdong Province will exceed the constraint index in 2020 according to the national development plan. However, the urbanization expansion based on the constraints of land development intensity and ecological protection can satisfy these constraints, and obtain a more compact landscape pattern. The analysis has shown that GeoSOS can be a useful tool for assisting in the analysis of geographic national conditions information

Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode

OpenAIRE

Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.

2010-01-01

Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma def...

Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis.

Directory of Open Access Journals (Sweden)

Xingmin Wang

Full Text Available The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR mutations (C677T and A1298C and methionine synthase reductase (MTRR mutation (A66G remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China.We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex.Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001. The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001.Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations.

Mapping the Distribution and Flora of the Weeds in Canola Fields of Gorgan Township by Geographic Information System (GIS

Directory of Open Access Journals (Sweden)

sahar jannati ataie

2018-02-01

Full Text Available Introduction: Oil seeds are the second world’s food supply after cereals. These crops are grown primarily for the oil contained in the seeds. The major world sources of edible seed oils are soybeans, sunflowers, canola, cotton and peanuts. Canola is one of the most important plants in the world that has great importance. The plant belongs to the Brassica genus, the botanical family that includes cauliflower and cabbages. Weeds are one of the major problems in canola production that reduce yield and its quality. In general, one of the most important factors in development of management plans is information about the weed’s flora and geographic distribution. Knowledge of weed flora enables one to use the required herbicide and formulate other suitable management strategies. It is also useful in exploiting abundant weeds as a cover crop or pasture and for other economic uses. The geographic information system has the proper use in weed science and management of agricultural information and their analysis. In this study, distribution and flora of the weeds in canola fields of Gorgan Township investigated by Geographic Information System. Material and Methods: Crop sampling was conducted during May and June 2014, in 58 canola fields in Gorgan Township (Golestan province and the weed species were sampled and detected using a W method and by specific formula of density, frequency, uniformity, and abundance of each weed species was calculated. Also, geographic coordinates of fields (latitude, altitude and elevation were determined by using GPS model Garmin map 60. After collecting data, in order to create a database of weed distribution, the data was transferred from GPS to ArcGIS 9/3.1 software. From all information obtained, consistently a database with location was created and after separation of data based on present or absence of weeds on fields, distribution maps were produced. Results and Discussion: The results showed that there are 35 weed

Review of the fossil matamata turtles: earliest well-dated record and hypotheses on the origin of their present geographical distribution

Science.gov (United States)

Ferreira, Gabriel S.; Rincón, Ascanio D.; Solórzano, Andrés; Langer, Max C.

2016-04-01

The matamata ( Chelus fimbriatus) is a highly aquatic chelid turtle known exclusively from northern South America. Due to its extremely modified morphology, it is well circumscribed among living taxa, but that is not the case of the two extinct species ascribed to the taxon, Chelus colombianus and Chelus lewisi. These were originally described for the Miocene of Colombia and Venezuela, respectively, and are known mostly from post-cranial material. Few traits have been considered diagnostic for these fossil taxa, and their shared geographic and temporal distributions raise doubts about their distinctiveness. Here, we describe new turtle remains from the early Miocene Castillo Formation, at Cerro la Cruz, northwestern Venezuela, assigning them to C. colombianus. We also review the taxonomy and diagnostic features of the fossil species of Chelus, comparing them with the variation recognized within C. fimbriatus. All alleged differences between the fossil Chelus species were found in our sample of the extant species, and may represent intraspecific variation of a single fossil species. Further, we reviewed the fossil record of Chelus spp. and proposed a paleobiogeographic hypothesis to explain its present geographic range.

Geographic thougth in Latin America: A retrospective and general balance

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Pedro Sergio Urquijo Torres

2016-08-01

Full Text Available In this paper we report results of a thorough contemporary historiographic revision of published geographic research and geography research departments and centers in Latin America. The main focus was on the recognition of transnational subjects and global processes and patterns. We argue that this type of retrospective analyses allows the understanding of the what and the what for of Latin America (LAG Geography. First we describe the current situation of LAG as a social science. Second, we explain the nature of LA social processes that, in the 90s, triggered geographic change and subsequent theoretical reflection on this change in LAG and in other related social sciences. To this end, we describe how the major traditions in geographic research have influenced LAG thinking. To conclude, we suggest the major achievements that we think characterize the current situation of LAG.

An assessment of geographical distribution of different plant functional types over North America simulated using the CLASS–CTEM modelling framework

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R. K. Shrestha

2017-10-01

Full Text Available The performance of the competition module of the CLASS–CTEM (Canadian Land Surface Scheme and Canadian Terrestrial Ecosystem Model modelling framework is assessed at 1° spatial resolution over North America by comparing the simulated geographical distribution of its plant functional types (PFTs with two observation-based estimates. The model successfully reproduces the broad geographical distribution of trees, grasses and bare ground although limitations remain. In particular, compared to the two observation-based estimates, the simulated fractional vegetation coverage is lower in the arid southwest North American region and higher in the Arctic region. The lower-than-observed simulated vegetation coverage in the southwest region is attributed to lack of representation of shrubs in the model and plausible errors in the observation-based data sets. The observation-based data indicate vegetation fractional coverage of more than 60 % in this arid region, despite only 200–300 mm of precipitation that the region receives annually, and observation-based leaf area index (LAI values in the region are lower than one. The higher-than-observed vegetation fractional coverage in the Arctic is likely due to the lack of representation of moss and lichen PFTs and also likely because of inadequate representation of permafrost in the model as a result of which the C3 grass PFT performs overly well in the region. The model generally reproduces the broad spatial distribution and the total area covered by the two primary tree PFTs (needleleaf evergreen trees, NDL-EVG; and broadleaf cold deciduous trees, BDL-DCD-CLD reasonably well. The simulated fractional coverage of tree PFTs increases after the 1960s in response to the CO2 fertilization effect and climate warming. Differences between observed and simulated PFT coverages highlight model limitations and suggest that the inclusion of shrubs, and moss and lichen PFTs, and an adequate representation of

Balanites aegyptiaca (L. Delile: geographical distribution and ethnobotanical knowledge by local populations in the Ferlo (north Senegal

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Sagna, MB.

2014-01-01

Full Text Available Balanites aegyptiaca (L. Delile is a species of tropical flora for which the variety aegyptiaca is adapted to Sahelian climate. The species is among those chosen for the restoration of Sahelian ecosystems in the context of the pan-African reforestation project, the Great Green Wall for the Sahara and Sahel Initiative (GGW. This study redefines the distribution range and its ecology and studies its uses in the Ferlo region in the north of Senegal using surveys carried out among the local population. The eco-geographical study shows that the species occupies several Sahel-Saharan regions of Africa and the Middle East. With broad ecological amplitude, it is very resistant to drought and relatively indifferent to the type of soil. Results of the ethno-botanical survey show that local people in the Ferlo region have a wealth of knowledge and expertise on B. aegyptiaca. These surveys also revealed the extent to which local populations rely on the tree for food, fodder, construction and medicine. The fruit and wood are the most highly prized parts of the tree, with the greatest use of the fruit in people's diets. In medicinal terms, B. aegyptiaca is used to treat several affections. Marketing the fruits could be of socio-economic interest for local people, and in particular, for women. This study is particularly opportune since B. aegyptiaca var. aegyptiaca is currently being planted in large numbers within the Great Green Wall for the Sahara and the Sahel Initiative (GGW. It also provides information that could help in better management of this natural resource, adapted both to the hostile Sahelian climate and of great use to Mankind.

Seasonal and geographical distribution of bacillary dysentery (shigellosis) and associated climate risk factors in Kon Tam Province in Vietnam from 1999 to 2013.

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Lee, Hu Suk; Ha Hoang, T T; Pham-Duc, Phuc; Lee, Mihye; Grace, Delia; Phung, Dac Cam; Thuc, Vu Minh; Nguyen-Viet, Hung

2017-06-21

Bacillary dysentery (BD) is an acute bacterial infection of the intestine caused by Shigella spp., with clinical symptoms ranging from fever to bloody diarrhoea to abdominal cramps to tenesmus. In Vietnam, enteric bacterial pathogens are an important cause of diarrhoea and most cases in children under 5 years of age are due to Shigella strains. The serogroups S. flexneri and S. sonnei are considered to be the most common. The main objective of this study was to, for the first time, assess the seasonal patterns and geographic distribution of BD in Vietnam, and to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, where the highest rate of bacillary dysentery was observed from 1999 to 2013. The seasonal patterns and geographic distribution of BD was assessed in Vietnam using a seasonal-trend decomposition procedure based on loess. In addition, negative binomial regression models were used to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, from 1999 to 2013. Overall, incidence rates of BD have slightly decreased over time (except for an extremely high incidence in 2012 in the north of Vietnam). The central regions (north/south central coast and central highlands) had relatively high incidence rates, whereas the northwest/east and Red River Delta regions had low incidence rates. Overall, seasonal plots showed a high peak in the mid-rainy reason and a second smaller peak in the early or late rainy season. The incidence rates significantly increased between May and October ("wet season") across the country. In Kon Tum Province, temperature, humidity, and precipitation were found to be positively associated with the incidence of BD. Our findings provide insights into the seasonal patterns and geographic distribution of BD in Vietnam and its associated climate risk factors in Kon Tum Province. This study may help clinicians and the general public to better understand the timings of

Current distribution and enhancement of the engineering critical current density in multifilament Bi-2223 tapes

DEFF Research Database (Denmark)

Wang, W.G.; Jensen, M.B.; Kindl, B.

2000-01-01

The spatial distribution of the critical current density (Jc) and engineering critical current density (Je) along the tape width direction was studied by a cutting technique on Bi-2223 multifilamentary tapes. In general, an increase of Jc towards the centre of the tape was measured. We attribute...... microstructure with a great amount of secondary phases. Local variation of Jc was measured within the centre segment of the tape. This indicates the influence of other factors on Jc, such as filament shape, connectivity of the filaments, and sausaging. Enhancement of Je has been pursued in which average Je of 12...

Geographic distance and pH drive bacterial distribution in alkaline lake sediments across Tibetan Plateau

Science.gov (United States)

Xiong, Jinbo; Liu, Yongqin; Lin, Xiangui; Zhang, Huayong; Zeng, Jun; Hou, Juzhi; Yang, Yongping; Yao, Tandong; Knight, Rob; Chu, Haiyan

2012-01-01

Continent-scale biogeography has been extensively studied in soils and marine systems, but little is known about biogeographical patterns in non-marine sediments. We used barcode pyrosequencing to quantify the effects of local geochemical properties and geographic distance for bacterial community structure and membership, using sediment samples from 15 lakes on the Tibetan Plateau (4–1670 km apart). Bacterial communities were surprisingly diverse, and distinct from soil communities. Four of 26 phyla detected were dominant: Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria, albeit 20.2% of sequences were unclassified at the phylum level. As previously observed in acidic soil, pH was the dominant factor influencing alkaline sediment community structure, phylotype richness and phylogenetic diversity. In contrast, archaeal communities were less affected by pH. More geographically distant sites had more dissimilar communities (r = 0.443, P = 0.030). Variance partitioning analysis showed that geographic distance (historical contingencies) contributed more to bacterial community variation (12.2%) than any other factor, although the environmental factors explained more variance when combined (28.9%). Together, our results show that pH is the best predictor of bacterial community structure in alkaline sediments, and confirm that both geographic distance and chemical factors govern bacterial biogeography in lake sediments. PMID:22676420

The advertisement call and geographic distribution of Proceratophrys dibernardoi Brandão, Caramaschi, Vaz-Silva & Campos 2013 (Anura, Odontophrynidae).

Science.gov (United States)

Ferreira, Cláudia Márcia Marily; Sugai, José Luiz Massao Moreira; DE Souza, Franco Leandro; DE Andrade, Sheila Pereira; Vaz-Silva, Wilian; Bastos, Rogério Pereira; DE Morais, Alessandro Ribeiro

2016-12-09

Proceratophrys dibernardoi Brandão, Caramaschi, Vaz-Silva & Campos 2013 has recently been described and allocated into the P. cristiceps species group, but no information about its advertisement calls has been provided (Brandão et al. 2013). Here, we describe for the first time the advertisement calls of P. dibernardoi based on specimens from Central Brazil. We also expand P. dibernardoi´s geographic distribution by reporting a new population in the State of Mato Grosso do Sul, Brazil, constituting the westernmost record for this species, and extending its known range approximately 330 km westward of the municipality of Aporé, State of Goiás (P. dibernardoi´s former westernmost record).

La mortalidad evitable y no evitable: distribución geográfica en áreas pequeñas de España (1990-2001 Avoidable and nonavoidable mortality: geographical distribution in small areas in Spain (1990-2001

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Montse Vergara Duarte

2009-02-01

Full Text Available Objetivo: La comparación de la mortalidad que puede ser evitada por intervención médica (mortalidad evitable en áreas geográficas pequeñas proporciona una herramienta útil para analizar con detalle la calidad de los servicios sanitarios. No hay estudios que analicen para toda España la distribución geográfica de la mortalidad evitable en áreas pequeñas. El objetivo de este estudio es describir la distribución geográfica de la mortalidad evitable y no evitable en áreas pequeñas según el sexo para el período 1990-2001. Métodos: Se consideraron 2.218 áreas pequeñas formadas por municipios o municipios agregados de todo el territorio español. Se analizaron las muertes evitables producidas en 1990-2001. Se estimó el riesgo relativo de muerte ajustado por edad utilizando un modelo bayesiano empírico. Los riesgos relativos se representaron en mapas para cada grupo de causas de muerte según el sexo. Resultados: La distribución geográfica de la mortalidad evitable en ambos sexos es heterogénea. Se observan áreas de mayor riesgo de mortalidad en el sur y el noroeste de España. Esta distribución se presenta claramente diferenciada, principalmente en hombres, para las causas de hipertensión, enfermedades y enfermedad isquémica del corazón. La distribución geográfica de la mortalidad no evitable, en ambos sexos, es similar a la de las tres causas mencionadas. Conclusiones La descripción de la mortalidad evitable en áreas pequeñas de toda España ha permitido identificar zonas geográficas con una elevada mortalidad. Para determinar los factores asociados a la distribución cerebrales vasculares de la mortalidad evitable se deberían realizar estudios más detallados.Objective: Comparison of mortality amenable to medical intervention (avoidable mortality in small geographical areas provides a useful tool to analyse quality of health care services. Currently there are no studies that analyse avoidable mortality by

AC losses in a type II superconductor strip with inhomogeneous critical current distribution

International Nuclear Information System (INIS)

Tsukamoto, Osami

2005-01-01

Analytical formulae derived by Brandt and Indenbom (1993 Phys. Rev. B 48 12893-906) and Norris (1970 J. Phys. D: Appl. Phys. 3 489-507) are often used to calculate the magnetization and AC transport current losses in HTS strip conductors, respectively. In these formulae, homogeneous distribution of critical sheet current density σ c in the strip is assumed. However, it is considered that σ c distributions are inhomogeneous in actual HTS strips and that the inhomogeneous σ c distributions cause deviations of the measured AC loss data of actual HTS strips from those formulae. A semi-analytical method to calculate AC transport current and magnetization losses is derived for a type II superconductor strip with inhomogeneous distribution of σ c in the direction of the strip width. The method is derived modifying the analysis of Brandt et al. The validity of the semi-analytical method is shown by comparing the results calculated by this method with those calculated by the Norris and Brandt formulae and by a different method of our previous work and also with experimental data. Moreover, it is shown that the deviation of the measured data from the Norris and Brandt models can be estimated by assuming proper σ c distributions

Geographic distribution of lung and stomach cancers in England and Wales over 50 years: changing and unchanging patterns.

Science.gov (United States)

Swerdlow, A J; dos Santos Silva, I

1991-05-01

The distribution of cancers of the lung and stomach in the counties of England and Wales in 1968-81 was mapped, and compared to the distribution in the country in 1921-30 described by Stocks. The high risk of stomach cancer in North Wales noted by Stocks was found still to exist in each sex, although its disparity from the rest of the country has diminished. In general the geographic distribution of stomach cancer in both periods has paralleled that of post-neonatal mortality, at the same time and earlier, as an index of general poverty, but postneonatal mortality in North Wales has not been exceptionally high. In 1921-30 the highest risk of lung cancer was in and around London. In the modern data this was still true for older women, but for men and women under 45 years of age, and to a lesser extent for older men, the pattern has changed greatly; the epidemic has moved north, and highest risk is now in Northumberland and Durham. This spread appears to have occurred earlier for men than for women, and for urban than for rural areas, occurring latest of all for women in rural areas. Regional disparity has also increased, especially in males: risks in the northern regions are now over twice those in much of Wales and the South.

[Geographical distribution and indicators entomologic of sinantropic triatomines captured in the State of Goiás].

Science.gov (United States)

de Oliveira, Antônio Wilson Soares; da Silva, Ionizete Garcia

2007-01-01

The geographic distribution of triatomines in Goiás and entomological indicators in the home environment are presented: home infestation, home triatomine density and vector infection by Trypanosoma cruzi. The indicators studied were from triatomines captured inside and outside homes in 201 municipalities in the State of Goiás, Brazil, between 2000 and 2003. A total of 249,868 home units were investigated and 51,570 triatomines were captured, and 335 specimens were found to be infected with Trypanosoma cruzi. Infestation outside the home was significantly greater than infestation inside the home for the species Triatoma sordida, followed by Panstrongylus megistus. The contrary was observed with the species Rhodnius neglectus, Panstrongylus geniculatus and Triatoma pseudomaculata (p<0.018). There was no significant difference between infestations inside and outside the home for the species Panstrongylus diasi, Triatoma costalimai and Triatoma williami. Only one specimen of Triatoma infestans was captured in the year 2000.

Predicting geographic distributions of Phacellodomus species (Aves: Furnariidae in South America based on ecological niche modeling

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Maria da Salete Gurgel Costa

2014-08-01

Full Text Available Phacellodomus Reichenbach, 1853, comprises nine species of Furnariids that occur in South America in open and generally dry areas. This study estimated the geographic distributions of Phacellodomus species in South America by ecological niche modeling. Applying maximum entropy method, models were produced for eight species based on six climatic variables and 949 occurrence records. Since highest climatic suitability for Phacellodomus species has been estimated in open and dry areas, the Amazon rainforest areas are not very suitable for these species. Annual precipitation and minimum temperature of the coldest month are the variables that most influence the models. Phacellodomus species occurred in 35 ecoregions of South America. Chaco and Uruguayan savannas were the ecoregions with the highest number of species. Despite the overall connection of Phacellodomus species with dry areas, species such as P. ruber, P. rufifrons, P. ferrugineigula and P. erythrophthalmus occurred in wet forests and wetland ecoregions.

Current distribution and conductance quantization in the integer quantum Hall regime

International Nuclear Information System (INIS)

Cresti, Alessandro; Farchioni, Riccardo; Grosso, Giuseppe; Parravicini, Giuseppe Pastori

2003-01-01

Charge transport of a two-dimensional electron gas in the presence of a magnetic field is studied by means of the Keldysh-Green function formalism and the tight-binding method. We evaluate the spatial distributions of persistent (equilibrium) and transport (nonequilibrium) currents, and give a vivid picture of their profiles. In the quantum Hall regime, we find exact conductance quantization both for persistent currents and for transport currents, even in the presence of impurity scattering centres and moderate disorder. (letter to the editor)

Current distribution and conductance quantization in the integer quantum Hall regime

Energy Technology Data Exchange (ETDEWEB)

Cresti, Alessandro [NEST-INFM and Dipartimento di Fisica ' E Fermi' , Universita di Pisa, via F Buonarroti 2, I-56127 Pisa (Italy); Farchioni, Riccardo [NEST-INFM and Dipartimento di Fisica ' E Fermi' , Universita di Pisa, via F Buonarroti 2, I-56127 Pisa (Italy); Grosso, Giuseppe [NEST-INFM and Dipartimento di Fisica ' E Fermi' , Universita di Pisa, via F Buonarroti 2, I-56127 Pisa (Italy); Parravicini, Giuseppe Pastori [NEST-INFM and Dipartimento di Fisica ' A Volta' , Universita di Pavia, via A Bassi 6, I-27100 Pavia (Italy)

2003-06-25

Charge transport of a two-dimensional electron gas in the presence of a magnetic field is studied by means of the Keldysh-Green function formalism and the tight-binding method. We evaluate the spatial distributions of persistent (equilibrium) and transport (nonequilibrium) currents, and give a vivid picture of their profiles. In the quantum Hall regime, we find exact conductance quantization both for persistent currents and for transport currents, even in the presence of impurity scattering centres and moderate disorder. (letter to the editor)

Exploring geographic distributions of high-risk water, sanitation, and hygiene practices and their association with child diarrhea in Uganda

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Mitsuaki Hirai

2016-10-01

Full Text Available Background: High-risk water, sanitation, and hygiene (WASH practices are still prevalent in most low-income countries. Because of limited access to WASH, children may be put at an increased risk of diarrheal diseases. Objectives: This study aims to 1 develop a new measure of WASH-induced burden, the WASH Resource Index (WRI, and estimate its correlation with child diarrhea and an additive index of high-risk WASH practices; 2 explore the geographic distribution of high-risk WASH practices, child diarrhea, and summary indices at the cluster level; and 3 examine the association between the WRI and child diarrhea at the individual level. Design: A sample of 7,019 children from the Uganda Demographic and Health Survey 2011 were included in this study. Principal component analysis was used to develop a WRI, and households were classified as WASH poorest, poorer, middle, richer, and richest. A hot spot analysis was conducted to assess whether and how high-risk WASH practices and child diarrhea were geographically clustered. A potential association between the WRI and child diarrhea was examined through a nested regression analysis. Results: High-risk WASH practices were clustered at geographically distant regions from Kampala. The 2-week prevalence of child diarrhea, however, was concentrated in Eastern and East Central regions where high-risk WASH practices were not prevalent. At the individual level, none of the high-risk WASH practices were significantly associated with child diarrhea. Being in the highest WASH quintile was, however, significantly associated with 24.9% lower prevalence of child diarrhea compared to being in the lowest quintile (p<0.05. Conclusions: Only a weak association was found between the WRI and child diarrhea in this study. Future research should explore the potential utility of the WRI to examine WASH-induced burden.

Urethroplasty: a geographic disparity in care.

Science.gov (United States)

Burks, Frank N; Salmon, Scott A; Smith, Aaron C; Santucci, Richard A

2012-06-01

Urethroplasty is the gold standard for urethral strictures but its geographic prevalence throughout the United States is unknown. We analyzed where and how often urethroplasty was being performed in the United States compared to other treatment modalities for urethral stricture. De-identified case logs from the American Board of Urology were collected from certifying/recertifying urologists from 2004 to 2009. Results were categorized by ZIP codes to determine the geographic distribution. Case logs from 3,877 urologists (2,533 recertifying and 1,344 certifying) were reviewed including 1,836 urethroplasties, 13,080 urethrotomies and 19,564 urethral dilations. The proportion of urethroplasty varied widely among states (range 0% to 17%). The ratio of urethroplasty-to-urethrotomy/dilation also varied widely from state to state, but overall 1 urethroplasty was performed for every 17 urethrotomies or dilations performed. Certifying urologists were 3 times as likely to perform urethroplasty as recertifying urologists (12% vs 4%, respectively, pUrethroplasties were performed more commonly in states with residency programs (mean 5% vs 3%). Some states reported no urethroplasties during the observation period (Vermont, North Dakota, South Dakota, Maine and West Virginia). To our knowledge this is the first report on the geographic distribution of urethroplasty for urethral stricture disease. There are large variations in the rates of urethroplasty performed throughout the United States, indicating a disparity of care, especially for those regions in which few or no urethroplasties were reported. This disparity may decrease with time as younger certifying urologists are performing 3 times as many urethroplasties as older recertifying urologists. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Geographic asymmetries of the Viking auroral distribution: Implications for ionospheric coordinate systems

International Nuclear Information System (INIS)

Hearn, D.J.; Elphinstone, R.D.; Murphree, J.S.; Cogger, L.L.

1993-01-01

Viking images of the auroral distribution have been used to investigate the relevance of various ionospheric coordinate systems. An important aspect of the large-scale auroral shape is its dependence on the asymmetries of the Earth's internal field. Model predictions of where the aurora occurs, using the equatorial plane's volume current density, agree with observations and imply that the internal field plays a more important role that generally believed. Historically, the belief that the internal field has only small effects seems to stem from the widespread use of the corrected geomagnetic and invariant coordinate systems. These systems involve the mapping of field lines and have advantages in statistical studies and comparisons; less sophisticated systems such as the eccentric dipole coordinate system should be used in individual studies and in studies involving differentiation or integration of some observational parameters. Observations of the auraoral distribution are give to illustrate the universal time, tilt angle, and Kp variability in different coordinate systems and demonstrate that the dominant variability of the aurora is due to internal field asymmetries. A new set of coordinate systems are briefly developed as examples of how to incorporate external field models into studies of auraoral images. It is proposed that the one of these coordinate systems can be used as a test of how well an external field model can match observed auroral distributions. 19 refs., 1 tab

Effective environmental factors on geographical distribution of traffic accidents on pedestrians, downtown of Tehran City.

Science.gov (United States)

Moradi, Ali; Rahmani, Khaled; Kavousi, Amir; Eshghabadi, Farshid; Nematollahi, Shahrzad; Zainni, Slahedyn; Soori, Hamid

2018-02-20

The aim of this study was to geographically analyse the traffic casualties in pedestrians in downtown of Tehran City. Study population consisted of pedestrians who had traffic injury accidents from April 2014 to March 2015 in Tehran City. Data were extracted from the offices of traffic police and municipality. For analysis of environmental factors and site of accidents, Ordinary Least Square (OLS) regression models and Geographically Weighted Regression (GWR) were used. All pedestrian accidents including 514 accidents were assessed in this study in which the site of accidents included arterial streets in 370 (71.9%) cases, collector streets in 133 cases (25.2%) and highways in 11 cases (2.1%). Geographical units of traffic accidents in pedestrians had statistically significant relationship with the number of bus stations, number of crossroads and recreational areas. Neighbourhoods close to markets are considered as the most dangerous places for injury in traffic accidents.

Distribution of electric currents in sunspots from photosphere to corona

Energy Technology Data Exchange (ETDEWEB)

Gosain, Sanjay [National Solar Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Démoulin, Pascal [Observatoire de Paris, LESIA, UMR 8109 (CNRS), F-92195 Meudon Principal Cedex (France); López Fuentes, Marcelo [Instituto de Astronomía y Física del Espacio (IAFE), UBA-CONICET, CC. 67, Suc. 28 Buenos Aires 1428 (Argentina)

2014-09-20

We present a study of two regular sunspots that exhibit nearly uniform twist from the photosphere to the corona. We derive the twist parameter in the corona and in the chromosphere by minimizing the difference between the extrapolated linear force-free field model field lines and the observed intensity structures in the extreme-ultraviolet images of the Sun. The chromospheric structures appear more twisted than the coronal structures by a factor of two. Further, we derive the vertical component of electric current density, j{sub z} , using vector magnetograms from the Hinode Solar Optical Telescope (SOT). The spatial distribution of j{sub z} has a zebra pattern of strong positive and negative values owing to the penumbral fibril structure resolved by Hinode/SOT. This zebra pattern is due to the derivative of the horizontal magnetic field across the thin fibrils; therefore, it is strong and masks weaker currents that might be present, for example, as a result of the twist of the sunspot. We decompose j{sub z} into the contribution due to the derivatives along and across the direction of the horizontal field, which follows the fibril orientation closely. The map of the tangential component has more distributed currents that are coherent with the chromospheric and coronal twisted structures. Moreover, it allows us to map and identify the direct and return currents in the sunspots. Finally, this decomposition of j{sub z} is general and can be applied to any vector magnetogram in order to better identify the weaker large-scale currents that are associated with coronal twisted/sheared structures.

The geographical distribution of leadership in globalized clinical trials.

Directory of Open Access Journals (Sweden)

Jarno Hoekman

Full Text Available BACKGROUND: Pharmaceutical trials are mainly initiated by sponsors and investigators in the United States, Western Europe and Japan. However, more and more patients are enrolled in Central and Eastern Europe, Latin America and Asia. The involvement of patients in new geographical settings raises questions about scientific and ethical integrity, especially when experience with those settings is lacking at the level of trial management. We therefore studied to what extent the geographical shift in patient enrolment is anticipated in the composition of trial management teams using the author nationalities on the primary outcome publication as an indicator of leadership. METHODS AND FINDINGS: We conducted a cohort-study among 1,445 registered trials in www.clinicaltrials.gov that could be matched with a primary outcome publication using clinical trial registry numbers listed in publications. The name of the sponsor and the enrolment countries were extracted from all registrations. The author-addresses of all authors were extracted from the publications. We searched the author-address of all publications to determine whether enrolment countries and sponsors listed on registrations also appeared on a matched publication. Of all sponsors, 80.1% were listed with an author-address on the publication. Of all enrolment countries, 50.3% appeared with an author-address on the publication. The listing of enrolment countries was especially low for industry-funded trials (39.9% as compared to government (90.4% and not-for-profit funding (93.7%. We found that listing of enrolment countries in industry-funded trials was higher for traditional research locations such as the United States (98.2% and Japan (72.0% as compared to nontraditional research locations such as Poland (27.3% and Mexico (14.1%. CONCLUSIONS: Despite patient enrolment efforts, the involvement of researchers from nontraditional locations in trial management as measured by their contribution to

The geographical distribution of leadership in globalized clinical trials.

Science.gov (United States)

Hoekman, Jarno; Frenken, Koen; de Zeeuw, Dick; Heerspink, Hiddo Lambers

2012-01-01

Pharmaceutical trials are mainly initiated by sponsors and investigators in the United States, Western Europe and Japan. However, more and more patients are enrolled in Central and Eastern Europe, Latin America and Asia. The involvement of patients in new geographical settings raises questions about scientific and ethical integrity, especially when experience with those settings is lacking at the level of trial management. We therefore studied to what extent the geographical shift in patient enrolment is anticipated in the composition of trial management teams using the author nationalities on the primary outcome publication as an indicator of leadership. We conducted a cohort-study among 1,445 registered trials in www.clinicaltrials.gov that could be matched with a primary outcome publication using clinical trial registry numbers listed in publications. The name of the sponsor and the enrolment countries were extracted from all registrations. The author-addresses of all authors were extracted from the publications. We searched the author-address of all publications to determine whether enrolment countries and sponsors listed on registrations also appeared on a matched publication. Of all sponsors, 80.1% were listed with an author-address on the publication. Of all enrolment countries, 50.3% appeared with an author-address on the publication. The listing of enrolment countries was especially low for industry-funded trials (39.9%) as compared to government (90.4%) and not-for-profit funding (93.7%). We found that listing of enrolment countries in industry-funded trials was higher for traditional research locations such as the United States (98.2%) and Japan (72.0%) as compared to nontraditional research locations such as Poland (27.3%) and Mexico (14.1%). Despite patient enrolment efforts, the involvement of researchers from nontraditional locations in trial management as measured by their contribution to manuscript writing is modest. This division of labor has

Research for the Influence of Distribution Network Line Reclosing Current on Line Protection

Directory of Open Access Journals (Sweden)

Yu Kansheng

2016-01-01

Full Text Available According to the distribution network line structure and reclosing control strategy, the system simulation model of distribution network lines has established based on the real-time digital simulation RTDS. Based on this, distribution network switching impulse current characteristic has researched with different capacity, different distribution and different load power factor under the different voltage switching angles. The results of the study provide a scientific basis for distribution network line protection setting, in order to further lay the foundation for improvement the validity and reliability of distribution network line protection action.

A Monte Carlo simulation on critical current distribution of bent-damaged multifilamentary Bi2223 composite tape

International Nuclear Information System (INIS)

Ochiai, S.; Okuda, H.; Fujimoto, M.; Shin, J.K.; Oh, S.S.; Ha, D.W.

2011-01-01

We simulate critical current distribution of bent-damaged Bi2223 composite tape. We use a Monte Carlo method and a damage evolution model for simulation. With the present simulation approach, experimental results are described well. Critical current distribution stems mainly from difference in damage evolution. It was attempted to reproduce the measured critical current (I c ) distributions of the Bi2223 composite tape bent by 0-0.833% by simulation. Simulation was carried out with a Monte Carlo method in combination with a model that correlates the critical current to damage evolution. Two variables that differ from specimen to specimen were input in the simulation. One was the damage strain parameter, with which the difference in extent of damage among specimens was expressed. Another was the original critical current (I c0 ) values at zero bending strain. With the present simulation approach, the measured distributions of critical current at various bending strains, and the measured variations of average and coefficient of variation of critical current values with increasing bending strain were reproduced well.

Analysis of strain distribution and critical current of superconductors based on a strain-critical current measurement system

International Nuclear Information System (INIS)

Liu Fang; Wu Yu; Long Feng

2010-01-01

Based on Pacman device which is widely used to investigate the axial strain dependence of the critical current in superconductors, the finite element analysis method is employed to carry out the force analysis of the spring and the superconducting strand, thereby the axial and lateral strain distributions of the superconducting strand are obtained. According to the two extreme assumptions(low inter-filament resistance and high inter-filament resistance), the effects of the strain homogeneity at the cross section of the superconductor on the critical current is analyzed combined with the Nb 3 Sn deviatoric strain-critical current scaling law. (authors)

Current distribution in parallel paths of the coils of a 50 Hz prototype dipole magnet

International Nuclear Information System (INIS)

Otter, A.J.

1995-06-01

The prototype dipole made for TRIUMF's Kaon Factory proposal used coils with 12 parallel paths to reduce eddy current losses in the conductors. The ac current distribution in these paths was non-uniform due to different self and mutual inductances. Small differences in inductance can cause large circulating currents in the parallel windings. This paper describes the measurement of the inductances and shows an attempt to predict the current distribution for two alternative connection schemes. (author). 4 refs., 8 figs

A mathematical model of the current density distribution in electrochemical cells - AUTHORS’ REVIEW

Directory of Open Access Journals (Sweden)

PREDRAG M. ŽIVKOVIĆ

2011-06-01

Full Text Available An approach based on the equations of electrochemical kinetics for the estimation of the current density distribution in electrochemical cells is presented. This approach was employed for a theoretical explanation of the phenomena of the edge and corner effects. The effects of the geometry of the system, the kinetic parameters of the cathode reactions and the resistivity of the solution are also discussed. A procedure for a complete analysis of the current distribution in electrochemical cells is presented.

Geographic range size and determinants of avian species richness

DEFF Research Database (Denmark)

Jetz, Walter; Rahbek, Carsten

2002-01-01

Geographic patterns in species richness are mainly based on wide-ranging species because their larger number of distribution records has a disproportionate contribution to the species richness counts. Here we demonstrate how this effect strongly influences our understanding of what determines spe...

Geographical Environment Factors and Risk Assessment of Tick-Borne Encephalitis in Hulunbuir, Northeastern China.

Science.gov (United States)

Li, Yifan; Wang, Juanle; Gao, Mengxu; Fang, Liqun; Liu, Changhua; Lyu, Xin; Bai, Yongqing; Zhao, Qiang; Li, Hairong; Yu, Hongjie; Cao, Wuchun; Feng, Liqiang; Wang, Yanjun; Zhang, Bin

2017-05-26

Tick-borne encephalitis (TBE) is one of natural foci diseases transmitted by ticks. Its distribution and transmission are closely related to geographic and environmental factors. Identification of environmental determinates of TBE is of great importance to understanding the general distribution of existing and potential TBE natural foci. Hulunbuir, one of the most severe endemic areas of the disease, is selected as the study area. Statistical analysis, global and local spatial autocorrelation analysis, and regression methods were applied to detect the spatiotemporal characteristics, compare the impact degree of associated factors, and model the risk distribution using the heterogeneity. The statistical analysis of gridded geographic and environmental factors and TBE incidence show that the TBE patients mainly occurred during spring and summer and that there is a significant positive spatial autocorrelation between the distribution of TBE cases and environmental characteristics. The impact degree of these factors on TBE risks has the following descending order: temperature, relative humidity, vegetation coverage, precipitation and topography. A high-risk area with a triangle shape was determined in the central part of Hulunbuir; the low-risk area is located in the two belts next to the outside edge of the central triangle. The TBE risk distribution revealed that the impact of the geographic factors changed depending on the heterogeneity.

n value and Jc distribution dependence of AC transport current losses in HTS conductors

International Nuclear Information System (INIS)

Ogawa, Jun; Sawai, Yusuke; Nakayama, Haruki; Tsukamoto, Osami; Miyagi, Daisuke

2004-01-01

Compared with LTS materials, HTS materials have some peculiarities affecting AC loss characteristics of the conductors. We measured the AC transport current losses in YBCO thin film coated conductors and a Bi2223/Ag sheathed tape. Comparing the measured data with analytical calculations, the dependence of the AC transport current losses on the n value and critical current density distributions are studied. It is shown that, considering the n values and J c distributions, the peculiarities in the HTS materials can be taken into consideration and the transport current losses in HTS conductors can be calculated by the same analytical method used for LTS

Geographic Names

Data.gov (United States)

Minnesota Department of Natural Resources — The Geographic Names Information System (GNIS), developed by the United States Geological Survey in cooperation with the U.S. Board of Geographic Names, provides...

Geographical imbalances and divides in the scientific production of climate change knowledge

DEFF Research Database (Denmark)

Pasgaard, Maya; Dalsgaard, Bo; Maruyama, Pietro K.

2015-01-01

Studies on scientific production of climate change knowledge show a geographical bias against the developing and more vulnerable regions of the world. If there is limited knowledge exchange between regions, this may deepen global knowledge divides and, thus, potentially hamper adaptive capacities....... Consequently, there is a need to further understand this bias, and, particularly, link it with the exchange of knowledge across borders. We use a world-wide geographical distribution of author affiliations in > 15,000 scientific climate change publications to show that (1) research production mainly takes...... are determined mainly by geographical proximity, common climates, and similar political and economic characteristics. This indicates that political-economic, social and educational-scientific initiatives targeted to enhance local research production and collaborations across geographical-climate module borders...

Current density distribution during disruptions and sawteeth in a simple model of plasma current in a tokamak

International Nuclear Information System (INIS)

Stefanovskii, A. M.

2011-01-01

The processes that are likely to accompany discharge disruptions and sawteeth in a tokamak are considered in a simple plasma current model. The redistribution of the current density in plasma is supposed to be primarily governed by the onset of the MHD-instability-driven turbulent plasma mixing in a finite region of the current column. For different disruption conditions, the variation in the total plasma current (the appearance of a characteristic spike) is also calculated. It is found that the numerical shape and amplitude of the total current spikes during disruptions approximately coincide with those measured in some tokamak experiments. Under the assumptions adopted in the model, the physical mechanism for the formation of the spikes is determined. The mechanism is attributed to the diffusion of the negative current density at the column edge into the zero-conductivity region. The numerical current density distributions in the plasma during the sawteeth differ from the literature data.

Methylmercury in fish from the South China Sea: Geographical distribution and biomagnification

International Nuclear Information System (INIS)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-01-01

Highlights: • A large-scale investigation of MeHg in 46 species of marine wild fish from South China Sea. • Log 10 MeHg concentration was significantly related to their length and wet weight. • Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. • Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic species. • Biomagnification of MeHg was site-specific. -- Abstract: We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ 15 N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log 10 MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log 10 (MeHg) and δ 15 N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea

Leishmania isoenzyme polymorphisms in Ecuador: Relationships with geographic distribution and clinical presentation

Science.gov (United States)

Calvopina, Manuel; Armijos, Rodrigo X; Marco, Jorge D; Uezato, Hiroshi; Kato, Hirotomo; Gomez, Eduardo A; Korenaga, Masataka; Barroso, Paola A; Mimori, Tatsuyuki; Cooper, Philip J; Nonaka, Shigeo; Hashiguchi, Yoshihisa

2006-01-01

Background Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed. Methods Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador. PMID:16968553

Spatiotemporal Distribution of U5MR and Their Relationship with Geographic and Socioeconomic Factors in China.

Science.gov (United States)

Li, Zeng; Fu, Jingying; Jiang, Dong; Lin, Gang; Dong, Donglin; Yan, Xiaoxi

2017-11-21

Epidemiological studies conducted around the world have reported that the under-five mortality rate (U5MR) is closely associated with income and educational attainment. However, geographic elements should also remain a major concern in further improving child health issues, since they often play an important role in the survival environment. This study was undertaken to investigate the relationship between the U5MR, geographic, and socioeconomic factors, and to explore the associated spatial variance of the relationship in China using the geographically weighted regression (GWR) model. The results indicate that the space pattern of a high U5MR had been narrowed notably during the period from 2001 to 2010. Nighttime lights (NL) and the digital elevation model (DEM) both have obvious influences on the U5MR, with the NL having a negative impact and DEM having a positive impact. Additionally, the relationship between the NL and DEM varied over space in China. Moreover, the relevance between U5MR and DEM was narrowed in 2010 compared to 2001, which indicates that the development of economic and medical standards can overcome geographical limits.

Spatiotemporal Distribution of U5MR and Their Relationship with Geographic and Socioeconomic Factors in China

Directory of Open Access Journals (Sweden)

Zeng Li

2017-11-01

Full Text Available Epidemiological studies conducted around the world have reported that the under-five mortality rate (U5MR is closely associated with income and educational attainment. However, geographic elements should also remain a major concern in further improving child health issues, since they often play an important role in the survival environment. This study was undertaken to investigate the relationship between the U5MR, geographic, and socioeconomic factors, and to explore the associated spatial variance of the relationship in China using the geographically weighted regression (GWR model. The results indicate that the space pattern of a high U5MR had been narrowed notably during the period from 2001 to 2010. Nighttime lights (NL and the digital elevation model (DEM both have obvious influences on the U5MR, with the NL having a negative impact and DEM having a positive impact. Additionally, the relationship between the NL and DEM varied over space in China. Moreover, the relevance between U5MR and DEM was narrowed in 2010 compared to 2001, which indicates that the development of economic and medical standards can overcome geographical limits.

Potential geographic distribution of hantavirus reservoirs in Brazil.

Directory of Open Access Journals (Sweden)

Stefan Vilges de Oliveira

Full Text Available Hantavirus cardiopulmonary syndrome is an emerging zoonosis in Brazil. Human infections occur via inhalation of aerosolized viral particles from excreta of infected wild rodents. Necromys lasiurus and Oligoryzomys nigripes appear to be the main reservoirs of hantavirus in the Atlantic Forest and Cerrado biomes. We estimated and compared ecological niches of the two rodent species, and analyzed environmental factors influencing their occurrence, to understand the geography of hantavirus transmission. N. lasiurus showed a wide potential distribution in Brazil, in the Cerrado, Caatinga, and Atlantic Forest biomes. Highest climate suitability for O. nigripes was observed along the Brazilian Atlantic coast. Maximum temperature in the warmest months and annual precipitation were the variables that most influence the distributions of N. lasiurus and O. nigripes, respectively. Models based on occurrences of infected rodents estimated a broader area of risk for hantavirus transmission in southeastern and southern Brazil, coinciding with the distribution of human cases of hantavirus cardiopulmonary syndrome. We found no demonstrable environmental differences among occurrence sites for the rodents and for human cases of hantavirus. However, areas of northern and northeastern Brazil are also apparently suitable for the two species, without broad coincidence with human cases. Modeling of niches and distributions of rodent reservoirs indicates potential for transmission of hantavirus across virtually all of Brazil outside the Amazon Basin.

Geographical distribution of Toxoplasma gondii genotypes in Asia: A link with neighboring continents.

Science.gov (United States)

Chaichan, P; Mercier, A; Galal, L; Mahittikorn, A; Ariey, F; Morand, S; Boumédiène, F; Udonsom, R; Hamidovic, A; Murat, J B; Sukthana, Y; Dardé, M L

2017-09-01

Defining the pattern of genetic diversity of Toxoplasma gondii is important to understand its worldwide distribution. During the last decades, a large number of studies have been published on Toxoplasma genotypes circulating in Europe, in North and South America. Two continents are still largely unexplored, Africa and, to a less extent, Asia. In this last continent, an increasing number of publications reported genotypes circulating in diverse provinces of China, but very few data are available for other Asian countries. After a systematic database search, 47 papers related to T. gondii genotypes in Asia were analyzed. Genetic characterization of DNA was performed by microsatellite markers, or more usually by a multiplex PCR using 11 PCR-RFLP markers, allowing data comparison to draw a first global picture of the population structure of this parasite throughout Asia. Overall, 390 isolates or DNA extracts were completely typed by PCR-RFLP and/or microsatellite marker methods, revealing 36 different PCR-RFLP or equivalent microsatellite genotypes: 15 genotypes identified by a ToxoDB number and 21 atypical or unique genotypes. The most common genotype found in Asia is the genotype ToxoDB#9 (Chinese 1). The clonal types I, II and II variant, and III were also commonly found in Asia. The geographical distribution of these genotypes across Asia may reflect either a continuum with Europe for the western part of Asia (presence of Type II), or the circulation of strains through animal migration or human activities between Africa and the Southwestern part of Asia (Africa 1 genotype in Turkey or ToxoDB#20 both I Sri-Lanka and in Ethiopia or Egypt). Although there are some indications of a genetic population structure in Southeast Asian countries different from the rest of Asia, more studies in this tropical part of Asia will be necessary for a region which represent as well as Africa one of the missing links of the T. gondii genetic diversity. Copyright © 2017 Elsevier B

Multiplicity distributions of charged hadrons produced in (anti)neutrino-deuterium charged- and neutral-current interactions

International Nuclear Information System (INIS)

Jongejans, B.; Tenner, A.G.; Apeldoorn, G.W. van

1989-01-01

Results are presented on the multiplicity distributions of charged hadrons produced in νn, νp, antiνn and antiνp charged-current interactions for the hadronic energy range 2GeV ≤ W ≤ 14GeV (corresponding approximately to the neutrino energy range 5GeV ≤ E ≤ 150GeV). The experimental distributions are analysed in terms of binomial distributions. With increasing hadronic energy it is found a smooth transition from an ordinary binomial via Poissonian to the negative binomial function. KNO scaling holds approximately for the multiplicity distribution for the whole phase space. Data on the multiplicity distributions for neutral-current interactions are also presented

Geographic Gossip: Efficient Averaging for Sensor Networks

Science.gov (United States)

Dimakis, Alexandros D. G.; Sarwate, Anand D.; Wainwright, Martin J.

Gossip algorithms for distributed computation are attractive due to their simplicity, distributed nature, and robustness in noisy and uncertain environments. However, using standard gossip algorithms can lead to a significant waste in energy by repeatedly recirculating redundant information. For realistic sensor network model topologies like grids and random geometric graphs, the inefficiency of gossip schemes is related to the slow mixing times of random walks on the communication graph. We propose and analyze an alternative gossiping scheme that exploits geographic information. By utilizing geographic routing combined with a simple resampling method, we demonstrate substantial gains over previously proposed gossip protocols. For regular graphs such as the ring or grid, our algorithm improves standard gossip by factors of $n$ and $\\sqrt{n}$ respectively. For the more challenging case of random geometric graphs, our algorithm computes the true average to accuracy $\\epsilon$ using $O(\\frac{n^{1.5}}{\\sqrt{\\log n}} \\log \\epsilon^{-1})$ radio transmissions, which yields a $\\sqrt{\\frac{n}{\\log n}}$ factor improvement over standard gossip algorithms. We illustrate these theoretical results with experimental comparisons between our algorithm and standard methods as applied to various classes of random fields.

Leadership for Distributed Teams

NARCIS (Netherlands)

De Rooij, J.P.G.

2009-01-01

The aim of this dissertation was to study the little examined, yet important issue of leadership for distributed teams. Distributed teams are defined as: “teams of which members are geographically distributed and are therefore working predominantly via mediated communication means on an

Geographic Media Literacy

Science.gov (United States)

Lukinbeal, Chris

2014-01-01

While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Forests: A Database; TOPICAL

International Nuclear Information System (INIS)

Brown, S

2001-01-01

A database was generated of estimates of geographically referenced carbon densities of forest vegetation in tropical Southeast Asia for 1980. A geographic information system (GIS) was used to incorporate spatial databases of climatic, edaphic, and geomorphological indices and vegetation to estimate potential (i.e., in the absence of human intervention and natural disturbance) carbon densities of forests. The resulting map was then modified to estimate actual 1980 carbon density as a function of population density and climatic zone. The database covers the following 13 countries: Bangladesh, Brunei, Cambodia (Campuchea), India, Indonesia, Laos, Malaysia, Myanmar (Burma), Nepal, the Philippines, Sri Lanka, Thailand, and Vietnam. The data sets within this database are provided in three file formats: ARC/INFO(trademark) exported integer grids, ASCII (American Standard Code for Information Interchange) files formatted for raster-based GIS software packages, and generic ASCII files with x, y coordinates for use with non-GIS software packages

Current distribution in triodes neglecting space charge and initial velocities

NARCIS (Netherlands)

Hamaker, H.C.

1950-01-01

A theory of the current distribution in triodes with positive grid is developed on the assumption that space charge and the initial velocities of both primary and secondary electrons may be neglected. This theory, which is originally due to De Lussanct de la Sablonière, has been put in a more lucid

Measurement of current distribution in a proton exchange membrane fuel cell with various flow arrangements – A parametric study

International Nuclear Information System (INIS)

Alaefour, Ibrahim; Karimi, G.; Jiao, Kui; Li, X.

2012-01-01

Highlights: ► Spatial local current distributions in a single PEMFC are measured. ► Effects of key operating conditions on the local current density are investigated. ► Increasing air and hydrogen stoichiometries improves local current density distributions. ► Operating pressure and temperature have negligible impact on local current distribution. - Abstract: Understanding of current distributions in proton exchange membrane fuel cells (PEMFCs) is crucial for designing cell components such as the flow field plates and the membrane electrode assembly (MEA). In this study, the spatial current density distributions in a single PEMFC with three serpentine flow channels are measured using a segmented bipolar plate and printed circuit board technique. The effects of key operating conditions such as stoichiometry ratios, inlet humidity levels, cell pressure and temperature on the local current density distributions for co-, counter-, and cross-flow arrangements are examined. It is observed that the local current density distribution over the MEA is directly affected by the cell operating conditions along with the configuration of the flow arrangement. It is also found that among the different flow configurations tested under the various operating conditions, the counter flow arrangement provides the optimum average current density and the lowest variations in the local current densities along the flow channels.

Direct observation of the current distribution in thin superconducting strips using magneto-optic imaging

International Nuclear Information System (INIS)

Johansen, T.H.; Baziljevich, M.; Bratsberg, H.; Galperin, Y.; Lindelof, P.E.; Shen, Y.; Vase, P.

1996-01-01

Magneto-optic imaging was used for a detailed study of the flux and current distribution of a long thin strip of YBa 2 Cu 3 O 7-δ placed in a perpendicular external magnetic field. The inverse magnetic problem, i.e., that of deriving from a field map the underlying current distribution, is formulated and solved for the strip geometry. Applying the inversion to the magneto-optically found field map we find on a model-independent basis the current distribution across the strip to be in remarkable agreement with the profile predicted by the Bean model. The paper also presents results on the behavior of the Bi-doped YIG film with in-plane anisotropy which we use as field indicator, explaining why previous measurements of flux density profiles have displayed surprisingly large deviations from the expected behavior. copyright 1996 The American Physical Society

Summer Steelhead Distribution [ds341

Data.gov (United States)

California Natural Resource Agency — Summer Steelhead Distribution October 2009 Version This dataset depicts observation-based stream-level geographic distribution of anadromous summer-run steelhead...

The geographical distribution and habitats of three liver fluke intermediate hosts in South - Africa and the health implications involved

Directory of Open Access Journals (Sweden)

K. N. de Kock

2008-09-01

Full Text Available Account is given of the distribution and habitats of the three Lymnaea species currently on recordin the National Freshwater Snail Collection (NFSC of South Africa. A total number of 616, 353and 202 loci (1/16th square degrees was respectively recorded for Lymnaea natalensis, L. columellaand L. truncatula. The number of loci in which the collection sites of each species was located, wasdistributed in intervals of mean annual air temperature and rainfall, as well as intervals of meanaltitude. A temperature index was calculated for all mollusc species in the database and the resultsused to rank them in order of their association with low to high climatic temperatures. Chi-squareand effect size values were calculated to determine the significance in differences between frequencies of occurrence of each species in, on, or at the different options for each of the variables investigated and also to determine the significance of the differences between the three species. None of the three Lymnaea species were well represented in the arid regions of the Northern ,Western and Eastern Cape Province, and only L. truncatula was reported from Lesotho. Lymnaeanatalensis is the most widespread of the three species, while the distribution of L. truncatula displaysa sporadic and limited pattern. The alien invader species L. columella was first reported from SouthAfrica in the early 1940’s but was so successful in its invasion of water-bodies in South Africa thatit is currently considered the third most widespread freshwater snail in the country. Lymnaea truncatula was the only one of the three species not recovered from all 14 water-body types represented in the database. The largest number of samples of L. truncatula by far, was yielded by marshes while the largest number of samples of the other two species was collected in rivers, streams and dams. The highest percentage occurrence of all three species was in habitats in which the water conditions were

Eddy current distribution and lift force for finite MAGLEV strips

Energy Technology Data Exchange (ETDEWEB)

Atherton, D L; Eastham, A R; Fombrun, C; Chong, M

1974-07-01

The transverse distribution of induced eddy currents across a flat conducing strip of finite width, due to a rectangular dc magnet moving above it, was modelled experimentally, and was compared with that calculated for an infinite sheet. The electrodynamic suspension was simulated by means of a stationary ac-excited copper magnet suspended above an aluminum strip, and the induced surface current density was measured by a voltage pickup probe connected to a lock-in amplifier. The effect of reducing strip width is examined and shown to produce high current densities close to the edges. These results are related to the variation of lift force with strip width, determined by impedance modelling. A slight enhancement of lift is evident for intermediate strip widths.

Mapping the Global Potential Geographical Distribution of Black Locust (Robinia Pseudoacacia L. Using Herbarium Data and a Maximum Entropy Model

Directory of Open Access Journals (Sweden)

Guoqing Li

2014-11-01

Full Text Available Black locust (Robinia pseudoacacia L. is a tree species of high economic and ecological value, but is also considered to be highly invasive. Understanding the global potential distribution and ecological characteristics of this species is a prerequisite for its practical exploitation as a resource. Here, a maximum entropy modeling (MaxEnt was used to simulate the potential distribution of this species around the world, and the dominant climatic factors affecting its distribution were selected by using a jackknife test and the regularized gain change during each iteration of the training algorithm. The results show that the MaxEnt model performs better than random, with an average test AUC value of 0.9165 (±0.0088. The coldness index, annual mean temperature and warmth index were the most important climatic factors affecting the species distribution, explaining 65.79% of the variability in the geographical distribution. Species response curves showed unimodal relationships with the annual mean temperature and warmth index, whereas there was a linear relationship with the coldness index. The dominant climatic conditions in the core of the black locust distribution are a coldness index of −9.8 °C–0 °C, an annual mean temperature of 5.8 °C–14.5 °C, a warmth index of 66 °C–168 °C and an annual precipitation of 508–1867 mm. The potential distribution of black locust is located mainly in the United States, the United Kingdom, Germany, France, the Netherlands, Belgium, Italy, Switzerland, Australia, New Zealand, China, Japan, South Korea, South Africa, Chile and Argentina. The predictive map of black locust, climatic thresholds and species response curves can provide globally applicable guidelines and valuable information for policymakers and planners involved in the introduction, planting and invasion control of this species around the world.

So far away, yet so close: strong genetic structure in Homonota uruguayensis (Squamata, Phyllodactylidae, a species with restricted geographic distribution in the Brazilian and Uruguayan Pampas.

Directory of Open Access Journals (Sweden)

Jéssica F Felappi

Full Text Available The Pampas is a biologically rich South American biome, but is poorly represented in phylogeographic studies. While the Pleistocene glacial cycles may have affected the evolutionary history of species distributed in forested biomes, little is known about their effects on the habitats that remained stable through glacial cycles. The South American Pampas have been covered by grasslands during both glacial and interglacial periods and therefore represent an interesting system to test whether the genetic structure in such environments is less pronounced. In this study, we sampled Pampean populations of Homonota uruguayensis from Southern Brazil and Uruguay to assess the tempo and mode of population divergence, using both morphological measurements and molecular markers. Our results indicate that, in spite of its narrow geographic distribution, populations of H. uruguayensis show high levels of genetic structure. We found four major well-supported mtDNA clades with strong geographic associations. Estimates of their divergence times fell between 3.16 and 1.82 million years before the present. Populations from the central portion of the species distribution, on the border between Uruguay and Brazil, have high genetic diversity and may have undergone a population expansion approximately 250,000 years before the present. The high degree of genetic structure is reflected in the analyses of morphological characters, and most individuals could be correctly assigned to their parental population based on morphology alone. Finally, we discuss the biogeographic and conservation implications of these findings.

Orobanche flava (Orobanchaceae in Poland: current distribution, taxonomy, hosts and plant communities

Directory of Open Access Journals (Sweden)

Piwowarczyk Renata

2014-06-01

Full Text Available Orobanche flava is a species of Central European mountain ranges, mainly the Alps and Carpathian Mts. The paper presents the current distribution of O. flava in Poland based on a critical revision of herbarium and literature data as well as results of field investigations conducted between 1999 and 2014. The distribution of species is centered in southern Poland, mainly in the Carpathian Mts., and, sporadically, in the Sudeten Mts. The distribution of O. flava in Poland is mapped. The taxonomy, biology, and ecology are also discussed.

Not to put too fine a point on it - does increasing precision of geographic referencing improve species distribution models for a wide-ranging migratory bat?

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Hayes, Mark A.; Ozenberger, Katharine; Cryan, Paul M.; Wunder, Michael B.

2015-01-01

Bat specimens held in natural history museum collections can provide insights into the distribution of species. However, there are several important sources of spatial error associated with natural history specimens that may influence the analysis and mapping of bat species distributions. We analyzed the importance of geographic referencing and error correction in species distribution modeling (SDM) using occurrence records of hoary bats (Lasiurus cinereus). This species is known to migrate long distances and is a species of increasing concern due to fatalities documented at wind energy facilities in North America. We used 3,215 museum occurrence records collected from 1950–2000 for hoary bats in North America. We compared SDM performance using five approaches: generalized linear models, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy models. We evaluated results using three SDM performance metrics (AUC, sensitivity, and specificity) and two data sets: one comprised of the original occurrence data, and a second data set consisting of these same records after the locations were adjusted to correct for identifiable spatial errors. The increase in precision improved the mean estimated spatial error associated with hoary bat records from 5.11 km to 1.58 km, and this reduction in error resulted in a slight increase in all three SDM performance metrics. These results provide insights into the importance of geographic referencing and the value of correcting spatial errors in modeling the distribution of a wide-ranging bat species. We conclude that the considerable time and effort invested in carefully increasing the precision of the occurrence locations in this data set was not worth the marginal gains in improved SDM performance, and it seems likely that gains would be similar for other bat species that range across large areas of the continent, migrate, and are habitat generalists.

Potential effects of climate change on geographic distribution of the Tertiary relict tree species Davidia involucrata in China

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Tang, Cindy Q.; Dong, Yi-Fei; Herrando-Moraira, Sonia; Matsui, Tetsuya; Ohashi, Haruka; He, Long-Yuan; Nakao, Katsuhiro; Tanaka, Nobuyuki; Tomita, Mizuki; Li, Xiao-Shuang; Yan, Hai-Zhong; Peng, Ming-Chun; Hu, Jun; Yang, Ruo-Han; Li, Wang-Jun; Yan, Kai; Hou, Xiuli; Zhang, Zhi-Ying; López-Pujol, Jordi

2017-01-01

This study, using species distribution modeling (involving a new approach that allows for uncertainty), predicts the distribution of climatically suitable areas prevailing during the mid-Holocene, the Last Glacial Maximum (LGM), and at present, and estimates the potential formation of new habitats in 2070 of the endangered and rare Tertiary relict tree Davidia involucrata Baill. The results regarding the mid-Holocene and the LGM demonstrate that south-central and southwestern China have been long-term stable refugia, and that the current distribution is limited to the prehistoric refugia. Given future distribution under six possible climate scenarios, only some parts of the current range of D. involucrata in the mid-high mountains of south-central and southwestern China would be maintained, while some shift west into higher mountains would occur. Our results show that the predicted suitable area offering high probability (0.5‒1) accounts for an average of only 29.2% among the models predicted for the future (2070), making D. involucrata highly vulnerable. We assess and propose priority protected areas in light of climate change. The information provided will also be relevant in planning conservation of other paleoendemic species having ecological traits and distribution ranges comparable to those of D. involucrata. PMID:28272437

Geographical distribution and profile of medical doctors in public sector hospitals of the Limpopo Province, South Africa.

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Ntuli, Samuel T; Maboya, Edwin

2017-09-27

The shortage and unequal distribution of medical doctors in low- and middle-income countries continues to be a public health concern. To establish the geographical distribution and demographic profile of medical doctors in public sector hospitals of the Limpopo Province, South Africa. The PERSAL system was used to obtain information on the number of medical doctors employed in public sector hospitals of the Limpopo Province. Data were exported from PERSAL's database and then analysed using STATA version 9.0. The mean age of the 887 medical doctors was 40.1 ± 11.2 years (range 24-79 years). Sixty per cent of the doctors were male, 66% were aged ≤ 45 years and 84% were African. Most of the doctors (86%) were medical officers, of which 55% had < 5 years working experience. Overall, the doctor-to-population ratio for the five districts in the province was 16.4/100 000, with Capricorn (33.7/100 000) and Waterberg (20.2/100 000) recording the highest ratios. A large proportion (43%) of medical officers are employed in the Capricorn District, of which 71% were practising at the tertiary hospital. This study demonstrated a shortage and maldistribution of medical doctors in the public sector hospitals of the Limpopo Province. This has a potentially negative effect on the delivery of an appropriate and efficient healthcare service to the population and requires urgent attention.

Medical specialists' choice of location: the role of geographical attachment in Norway.

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Kristiansen, I S; Førde, O H

1992-01-01

The relation between current place of work (area of the country) and factors that might possibly represent doctors geographical attachments was studied in a sample of 322 Norwegian medical specialists. Location of hospital residency, age and geographical origin of spouse were associated with current location. Geographical attachment seems to influence doctors' locational choices from start of medical school until the end of their residency. The probability that a doctor shall locate in peripheral areas may increase from less than 10% to more than 50% if the doctor has the residency training in the periphery. Hence, favoring entrance to medical schools of students from the underserved areas, and location of graduate and postgraduate medical training in the underserved areas, as far as it is feasible while still maintaining medical standards, is suggested by the study.

Physical-geographical landscape of the tourist circuit Chilpancingo-Azul, Guerrero State, Mexico

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Julio C. Carbajal Monroy

2011-02-01

Full Text Available This work deals with the delimitation of physical-geographical landscapes of the territory of the Tourist Circuit Chilpancingo Azul, at Guerrero's State central region, from geo-ecological conception for the physical-geographical synthetic classification of territorial units. This approach obtained territorial units and its hierarchical classification using a taxonomic system of localities, neighborhoods and boroughs (smallest categories. Taking into account the 1:100 000 scale different geographical units were determined: 3 localities, 31 neighborhoods and 177 boroughs. The characterization of these territorial units include lithologic constitution, geomorphological conditions (morphogenesis and morphometrics and spatial distribution of major types of soils and vegetation and land uses in the territory.

Reduced pollinator service and elevated pollen limitation at the geographic range limit of an annual plant.

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Moeller, David A; Geber, Monica A; Eckhart, Vincent M; Tiffin, Peter

2012-05-01

Mutualisms are well known to influence individual fitness and the population dynamics of partner species, but little is known about whether they influence species distributions and the location of geographic range limits. Here, we examine the contribution of plant-pollinator interactions to the geographic range limit of the California endemic plant Clarkia xantiana ssp. xantiana. We show that pollinator availability declined from the center to the margin of the geographic range consistently across four years of study. This decline in pollinator availability was caused to a greater extent by variation in the abundance of generalist rather than specialist bee pollinators. Climate data suggest that patterns of precipitation in the current and previous year drove variation in bee abundance because of its effects on cues for bee emergence in the current year and the abundance of floral resources in the previous year. Experimental floral manipulations showed that marginal populations had greater outcross pollen limitation of reproduction, in parallel with the decline in pollinator abundance. Although plants are self-compatible, we found no evidence that autonomous selfing contributes to reproduction, and thus no evidence that it alleviates outcross pollen limitation in marginal populations. Furthermore, we found no association between the distance to the range edge and selfing rate, as estimated from sequence and microsatellite variation, indicating that the mating system has not evolved in response to the pollination environment at the range periphery. Overall, our results suggest that dependence on pollinators for reproduction may be an important constraint limiting range expansion in this system.

Case studies in geographic information systems for environmental streamlining

Science.gov (United States)

2012-05-31

This 2012 summary report addresses the current use of geographic information systems (GIS) and related technologies by State Departments of Transportation (DOTs) for environmental streamlining and stewardship, particularly in relation to the National...

Leishmania isoenzyme polymorphisms in Ecuador: Relationships with geographic distribution and clinical presentation

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Mimori Tatsuyuki

2006-09-01

Full Text Available Abstract Background Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL from Ecuador were analyzed. Methods Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia panamensis (21 isolates, 7 zymodemes, L. (V. guyanensis (7 isolates, 4 zymodemes, L. (V. braziliensis (5 isolates, 3 zymodemes, L. (Leishmania mexicana (11 isolates, 4 zymodemes, L. (L. amazonensis (10 isolates, 2 zymodemes and L. (L. major (2 isolates, 1 zymodeme. L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL; eight cases of leishmaniasis recidiva cutis (LRC found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador.

Geographical distribution patterns of iodine in drinking-water and its associations with geological factors in Shandong Province, China.

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Gao, Jie; Zhang, Zhijie; Hu, Yi; Bian, Jianchao; Jiang, Wen; Wang, Xiaoming; Sun, Liqian; Jiang, Qingwu

2014-05-19

County-based spatial distribution characteristics and the related geological factors for iodine in drinking-water were studied in Shandong Province (China). Spatial autocorrelation analysis and spatial scan statistic were applied to analyze the spatial characteristics. Generalized linear models (GLMs) and geographically weighted regression (GWR) studies were conducted to explore the relationship between water iodine level and its related geological factors. The spatial distribution of iodine in drinking-water was significantly heterogeneous in Shandong Province (Moran's I = 0.52, Z = 7.4, p water were identified in the south-western and north-western parts of Shandong Province by the purely spatial scan statistic approach. Both GLMs and GWR indicated a significantly global association between iodine in drinking-water and geological factors. Furthermore, GWR showed obviously spatial variability across the study region. Soil type and distance to Yellow River were statistically significant at most areas of Shandong Province, confirming the hypothesis that the Yellow River causes iodine deposits in Shandong Province. Our results suggested that the more effective regional monitoring plan and water improvement strategies should be strengthened targeting at the cluster areas based on the characteristics of geological factors and the spatial variability of local relationships between iodine in drinking-water and geological factors.

Experimental investigation of localized stress-induced leakage current distribution in gate dielectrics using array test circuit

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Park, Hyeonwoo; Teramoto, Akinobu; Kuroda, Rihito; Suwa, Tomoyuki; Sugawa, Shigetoshi

2018-04-01

Localized stress-induced leakage current (SILC) has become a major problem in the reliability of flash memories. To reduce it, clarifying the SILC mechanism is important, and statistical measurement and analysis have to be carried out. In this study, we applied an array test circuit that can measure the SILC distribution of more than 80,000 nMOSFETs with various gate areas at a high speed (within 80 s) and a high accuracy (on the 10-17 A current order). The results clarified that the distributions of localized SILC in different gate areas follow a universal distribution assuming the same SILC defect density distribution per unit area, and the current of localized SILC defects does not scale down with the gate area. Moreover, the distribution of SILC defect density and its dependence on the oxide field for measurement (E OX-Measure) were experimentally determined for fabricated devices.

Geographical Clusters and Predictors of Rabies in Three Southeastern States.

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Reilly, Sara; Sanderson, Wayne T; Christian, W Jay; Browning, Steven R

2017-06-01

The rabies virus causes progressive encephalomyelitis that is fatal in nearly 100% of untreated cases. In the United States, wildlife act as the primary reservoir for rabies; prevention, surveillance, and control costs remain high. The purpose of this study is to understand the current distribution of wildlife rabies in three southeastern states, with particular focus on raccoons as the primary eastern reservoir, as well as identify demographic and geographic factors which may affect the risk of human exposure. This ecologic study obtained county-level rabies surveillance data from state health departments and the United States Department of Agriculture Wildlife services for North Carolina, Virginia, and West Virginia from 2010 to 2013. A spatial statistical analysis was performed to identify county clusters with high or low rates of raccoon rabies in the three states. Potential demographic and geographic factors associated with these varying rates of rabies were assessed using a multivariable negative binomial regression model. In North Carolina, raccoons constituted 50% of positive tests, in Virginia, 49%, and in West Virginia, 50%. Compared to persons residing in West Virginia counties, persons in North Carolina counties had 1.67 times the risk of exposure (p rabies exposure. Further research is needed to better understand the effect of the oral rabies vaccine program in controlling the risk of human exposure to raccoon rabies.

Geographical Clusters of Rape in the United States: 2000-2012

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Amin, Raid; Nabors, Nicole S.; Nelson, Arlene M.; Saqlain, Murshid; Kulldorff, Martin

2016-01-01

Background While rape is a very serious crime and public health problem, no spatial mapping has been attempted for rape on the national scale. This paper addresses the three research questions: (1) Are reported rape cases randomly distributed across the USA, after being adjusted for population density and age, or are there geographical clusters of reported rape cases? (2) Are the geographical clusters of reported rapes still present after adjusting for differences in poverty levels? (3) Are there geographical clusters where the proportion of reported rape cases that lead to an arrest is exceptionally low or exceptionally high? Methods We studied the geographical variation of reported rape events (2003-2012) and rape arrests (2000-2012) in the 48 contiguous states of the USA. The disease Surveillance software SaTScan™ with its spatial scan statistic is used to evaluate the spatial variation in rapes. The spatial scan statistic has been widely used as a geographical surveillance tool for diseases, and we used it to identify geographical areas with clusters of reported rape and clusters of arrest rates for rape. Results The spatial scan statistic was used to identify geographical areas with exceptionally high rates of reported rape. The analyses were adjusted for age, and in secondary analyses, for both age and poverty level. We also identified geographical areas with either a low or a high proportion of reported rapes leading to an arrest. Conclusions We have identified geographical areas with exceptionally high (low) rates of reported rape. The geographical problem areas identified are prime candidates for more intensive preventive counseling and criminal prosecution efforts by public health, social service, and law enforcement agencies Geographical clusters of high rates of reported rape are prime areas in need of expanded implementation of preventive measures, such as changing attitudes in our society toward rape crimes, in addition to having the criminal

Report of study group 5.4 remote operation of distribution networks; Rapport du comite de travail 5.4 distribution du gaz: exploitation a distance des reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Spohn, D.; Osiadacz, A.

2000-07-01

This study by the IGU WOC 5.4 reviews, at a management level, the application of remote monitoring and control systems for distribution networks. Gas distribution companies have to carefully balance the safety, quality, economic and financial aspects of managing geographically distributed assets to meet customer needs. Remote systems are a key tool in meeting these objectives. A questionnaire was developed to identify the key drives for the selection of remote monitoring and control systems, high level company parameters and current technologies in use. The field in questionnaires received by the WOC 5.4 show that monitoring equipment and remote control systems for gas distribution in various configurations are commonly utilized by the firms operating in this field. The reason why the firms themselves did adopt a remote control system mainly depends on safety as well as on a reduction of operating costs due to reduction in the personnel and related overheads associated with the management of the system. (authors)

Using geographic distribution of well-screen depths and hydrogeologic conditions to identify areas of concern for contaminant migration through inactive supply wells

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Gailey, Robert M.

2018-02-01

Contaminant migration through inactive supply wells can negatively affect groundwater quality and the combined effects from groups of such wells may cause greater impacts. Because the number of wells in many basins is often large and the geographic areas involved can be vast, approaches are needed to estimate potential impacts and focus limited resources for investigation and corrective measures on the most important areas. One possibility is to evaluate the geographic distribution of well-screen depths relative to hydrogeologic conditions and assess where contaminant migration through wells may be impacting groundwater quality. This approach is demonstrated for a geographically extensive area in the southern Central Valley of California, USA. The conditions that lead to wells acting as conduits for contaminant migration are evaluated and areas where the problem likely occurs are identified. Although only a small fraction of all wells appear to act as conduits, potential impacts may be significant considering needs to control nonpoint-source pollution and improve drinking water quality for rural residents. Addressing a limited number of areas where contaminant migration rates are expected to be high may cost-effectively accomplish the most beneficial groundwater quality protection and improvement. While this work focuses on a specific region, the results indicate that impacts from groups of wells may occur in other areas with similar conditions. Analyses similar to that demonstrated here may guide efficient investigation and corrective action in such areas with benefits occurring for groundwater quality. Potential benefits may justify expenditures to develop the necessary data for performing the analyses.

Geographic analysis of shigellosis in Vietnam.

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Kim, Deok Ryun; Ali, Mohammad; Thiem, Vu Dinh; Park, Jin-Kyung; von Seidlein, Lorenz; Clemens, John

2008-12-01

Geographic and ecological analysis may provide investigators useful ecological information for the control of shigellosis. This paper provides distribution of individual Shigella species in space, and ecological covariates for shigellosis in Nha Trang, Vietnam. Data on shigellosis in neighborhoods were used to identify ecological covariates. A Bayesian hierarchical model was used to obtain joint posterior distribution of model parameters and to construct smoothed risk maps for shigellosis. Neighborhoods with a high proportion of worshippers of traditional religion, close proximity to hospital, or close proximity to the river had increased risk for shigellosis. The ecological covariates associated with Shigella flexneri differed from the covariates for Shigella sonnei. In contrast the spatial distribution of the two species was similar. The disease maps can help identify high-risk areas of shigellosis that can be targeted for interventions. This approach may be useful for the selection of populations and the analysis of vaccine trials.

Current distribution of Pilularia globulifera L. in Poland – changes of geographical range and habitat preferences

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Ewa Szczęśniak

2012-10-01

Full Text Available Pilularia globulifera is a subatlantic European fern threatened with extinction. In Poland, it reaches the eastern border of its continuous range. Up to the end of the 20th century, it was observed here in 21 stands; only 2 of them existed by the second half of the century, so the species was categorized as critically endangered. Five new locations have been found in western and northwestern Poland during the last 10 years. Abundant and permanent populations grow in 3 locations, while 2 stands were ephemeral. All the current stands are situated in anthropogenic habitats with spontaneous vegetation, in oligotrophic to eutrophic waters. One of the new localities is about 280 km distant from the eastern range of the limit known previously. Pilularia forms its own plant community Pilularietum globuliferae, enters plots of Ranunculo-Juncetum bulbosi and occurs in mesotrophic to eutrophic rushes of Eleocharis palustris, Phragmites australis, Typha angustifolia and Equisetum fluviatile. Specimens are vigorous and regularly produce sporocarps.

Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode.

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Poehlmann, Flavio R; Cappelli, Mark A; Rieker, Gregory B

2010-12-01

Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively.