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Sample records for affected geographic distribution

  1. Geographic Distance Affects Dispersal of the Patchy Distributed Greater Long-Tailed Hamster (Tscherskia triton)

    PubMed Central

    Xue, Huiliang; Zhong, Min; Xu, Jinhui; Xu, Laixiang

    2014-01-01

    Dispersal is a fundamental process in ecology influencing the genetic structure and the viability of populations. Understanding how variable factors influence the dispersal of the population is becoming an important question in animal ecology. To date, geographic distance and geographic barriers are often considered as main factors impacting dispersal, but their effects are variable depending on different conditions. In general, geographic barriers affect more significantly than geographic distance on dispersal. In rapidly expanding populations, however, geographic barriers have less effect on dispersal than geographic distance. The effects of both geographic distance and geographic barriers in low-density populations with patchy distributions are poorly understood. By using a panel of 10 microsatellite loci we investigated the genetic structure of three patchy-distributed populations of the Greater long-tailed hamster (Tscherskia triton) from Raoyang, Guan and Shunyi counties of the North China Plain. The results showed that (i) high genetic diversity and differentiation exist in three geographic populations with patchy distributions; (ii) gene flow occurs among these three populations with physical barriers of Beijing city and Hutuo River, which potentially restricted the dispersal of the animal; (iii) the gene flow is negatively correlated with the geographic distance, while the genetic distance shows the positive correlation. Our results suggest that the effect of the physical barriers is conditional-dependent, including barrier capacity or individual potentially dispersal ability. Geographic distance also acts as an important factor affecting dispersal for the patchy distributed geographic populations. So, gene flow is effective, even at relatively long distances, in balancing the effect of geographic barrier in this study. PMID:24911266

  2. Lichen-Associated Fungal Community in Hypogymnia hypotrypa (Parmeliaceae, Ascomycota) Affected by Geographic Distribution and Altitude

    PubMed Central

    Wang, Yanyan; Zheng, Yong; Wang, Xinyu; Wei, Xinli; Wei, Jiangchun

    2016-01-01

    Lichen-associated fungal species have already been investigated in almost all the main growth forms of lichens, however, whether or not they are homogeneous and constant within each lichen species are still inconclusive. Moreover, the related ecological factors to affect and structure the fungal composition have been poorly studied. In order to answer these questions, we took Hypogymnia hypotrypa as a model to study the relationship between the lichen-associated fungal composition and two ecological factors, i.e., site and altitude, using the method of IlluminaMiSeq sequencing. Four different sites and two levels of altitude were included in this study, and the effects of site and altitude on fungal community composition were assessed at three levels, i.e., operational taxonomic unit (OTU), class and phylum. The results showed that a total of 50 OTUs were identified and distributed in 4 phyla, 13 classes, and 20 orders. The lichen-associated fungal composition within H. hypotrypa were significantly affected by both site and altitude at OTU and class levels, while at the phylum level, it was only affected by altitude. While the lichen associated fungal communities were reported to be similar with endophytic fungi of the moss, our results indicated the opposite results in some degree. But whether there exist specific OTUs within this lichen species corresponding to different sites and altitudes is still open. More lichen species and ecological factors would be taken into the integrated analyses to address these knowledge gaps in the near future. PMID:27547204

  3. Lichen-Associated Fungal Community in Hypogymnia hypotrypa (Parmeliaceae, Ascomycota) Affected by Geographic Distribution and Altitude.

    PubMed

    Wang, Yanyan; Zheng, Yong; Wang, Xinyu; Wei, Xinli; Wei, Jiangchun

    2016-01-01

    Lichen-associated fungal species have already been investigated in almost all the main growth forms of lichens, however, whether or not they are homogeneous and constant within each lichen species are still inconclusive. Moreover, the related ecological factors to affect and structure the fungal composition have been poorly studied. In order to answer these questions, we took Hypogymnia hypotrypa as a model to study the relationship between the lichen-associated fungal composition and two ecological factors, i.e., site and altitude, using the method of IlluminaMiSeq sequencing. Four different sites and two levels of altitude were included in this study, and the effects of site and altitude on fungal community composition were assessed at three levels, i.e., operational taxonomic unit (OTU), class and phylum. The results showed that a total of 50 OTUs were identified and distributed in 4 phyla, 13 classes, and 20 orders. The lichen-associated fungal composition within H. hypotrypa were significantly affected by both site and altitude at OTU and class levels, while at the phylum level, it was only affected by altitude. While the lichen associated fungal communities were reported to be similar with endophytic fungi of the moss, our results indicated the opposite results in some degree. But whether there exist specific OTUs within this lichen species corresponding to different sites and altitudes is still open. More lichen species and ecological factors would be taken into the integrated analyses to address these knowledge gaps in the near future. PMID:27547204

  4. Ticks: Geographic Distribution

    MedlinePlus

    ... Atlas. Download this map [PDF - 1 page] Lone star tick ( Amblyomma americanum ) Where found: Widely distributed in ... is distinguished by a white dot or “lone star” on her back. Lone star tick saliva can ...

  5. Geographic distribution of Bhanja virus.

    PubMed

    Hubálek, Z

    1987-01-01

    A review on the geographic distribution, vectors and hosts of Bhanja virus (Bunyaviridae) is based on reports about: isolations of the virus; antibody surveys. Bhanja virus has been isolated in 15 countries of Asia, Africa and Europe, and antibodies against it have been detected in 15 additional countries. Vector range includes ticks of the family Ixodidae (subfam. Amblyomminae; not subfam. Ixodinae): 13 species of 6 genera (Haemaphysalis, Dermacentor, Hyalomma, Amblyomma, Rhipicephalus and Boophilus) yielded the virus. Bhanja virus has only rarely been isolated from vertebrates (Atelerix, Xerus, Ovis, Bos; possibly bats), though antibodies have been detected frequently in a wide range of mammals (Ruminantia being the major hosts), in several species of birds (Passeriformes, Galliformes) and even reptiles (Ophisaurus apodus). Natural foci of the Bhanja virus infections are of the boskematic type (sensu Rosický), associated closely with pastures of domestic ruminants infested by ticks in the regions of tropical, subtropical and partly temperate climatic zones. PMID:3108117

  6. 34 CFR 642.33 - Geographic distribution.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Geographic distribution. 642.33 Section 642.33 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY... Grant? § 642.33 Geographic distribution. The Secretary, to the greatest extent possible, awards...

  7. 7 CFR 3565.213 - Geographic distribution.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Geographic distribution. 3565.213 Section 3565.213 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.213 Geographic distribution....

  8. 7 CFR 3565.213 - Geographic distribution.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Geographic distribution. 3565.213 Section 3565.213 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.213 Geographic distribution....

  9. Geographical distribution of the dermatophytes: a review.

    PubMed Central

    Philpot, C. M.

    1978-01-01

    In these days of rapid transit from continent to continent, and the increasing mobility of people, agents of disease are no longer geographically restricted. Disease contracted half way across the world may become manifest in a country in which the pathogen is not normally found. Thus knowledge of the geographical distribution of pathogens becomes increasingly important when a diagnosis is being made. This is as true of ringworm fungi as of any other group of microorganisms. In the last 12 years, in the Mycological Reference Laboratory, an increasing number of exotic dermatophytes have been seen, related in part at least to the great increase in the number of non-British residents. Not all species of dermatophytes are cosmopolitan in their distribution throughout the world. While some have been recorded from every continent, others have geographically limited areas of greater or lesser extent. Surveys taken at intervals in a country may show a rise and fall in occurrence of several species as habits change, populations move and medical facilities became increasingly well-distributed. There have been few geographical surveys of ringworm fungi that have covered the world. Ajello (1960, 1974) has reviewed the individual species with regard to geographical location, while Vanbreuseghem & de Vroey (1970) attempted to estimate the relative importance of the various species in terms of numbers of isolations reported. This paper therefore reviews the world dermatophyte flora in terms of the dominant agents in the various countries, and some of the changes that have been recorded. PMID:75918

  10. The Geographic Distribution of Indochinese Refugees.

    ERIC Educational Resources Information Center

    Forbes, Susan

    This paper presents information regarding the geographic distribution of Indochinese refugees in the United States and how it compares to that of the overall U.S. population and the non-refugee legal immigrant population. The following information is reported: Seventy percent of all Indochinese refugees currently reside in 10 States, with…

  11. Distributed Object Oriented Geographic Information System

    1997-02-01

    This interactive, object-oriented, distributed Geographic Information System (GIS) uses the World Wibe Web (WWW) as application medium and distribution mechanism. The software provides distributed access to multiple geo-spatial databases and presents them as if they came from a single coherent database. DOOGIS distributed access comes not only in the form of multiple geo-spatial servers but can break down a single logical server into the constituent physical servers actually storing the data. The program provides formore » dynamic protocol resolution and content handling allowing unknown objects from a particular server to download their handling code. Security and access privileges are negotiated dynamically with each server contacted and each access attempt.« less

  12. Optimization of tomographic reconstruction workflows on geographically distributed resources.

    PubMed

    Bicer, Tekin; Gürsoy, Dogˇa; Kettimuthu, Rajkumar; De Carlo, Francesco; Foster, Ian T

    2016-07-01

    New technological advancements in synchrotron light sources enable data acquisitions at unprecedented levels. This emergent trend affects not only the size of the generated data but also the need for larger computational resources. Although beamline scientists and users have access to local computational resources, these are typically limited and can result in extended execution times. Applications that are based on iterative processing as in tomographic reconstruction methods require high-performance compute clusters for timely analysis of data. Here, time-sensitive analysis and processing of Advanced Photon Source data on geographically distributed resources are focused on. Two main challenges are considered: (i) modeling of the performance of tomographic reconstruction workflows and (ii) transparent execution of these workflows on distributed resources. For the former, three main stages are considered: (i) data transfer between storage and computational resources, (i) wait/queue time of reconstruction jobs at compute resources, and (iii) computation of reconstruction tasks. These performance models allow evaluation and estimation of the execution time of any given iterative tomographic reconstruction workflow that runs on geographically distributed resources. For the latter challenge, a workflow management system is built, which can automate the execution of workflows and minimize the user interaction with the underlying infrastructure. The system utilizes Globus to perform secure and efficient data transfer operations. The proposed models and the workflow management system are evaluated by using three high-performance computing and two storage resources, all of which are geographically distributed. Workflows were created with different computational requirements using two compute-intensive tomographic reconstruction algorithms. Experimental evaluation shows that the proposed models and system can be used for selecting the optimum resources, which in turn can

  13. Geographic Distribution of Urologists in Korea, 2007 to 2012.

    PubMed

    Song, Yun Seob; Shim, Sung Ryul; Jung, Insoo; Sun, Hwa Yeon; Song, Soo Hyun; Kwon, Soon-Sun; Ko, Young Myoung; Kim, Jae Heon

    2015-11-01

    The adequacy of the urologist work force in Korea has never been investigated. This study investigated the geographic distribution of urologists in Korea. County level data from the National Health Insurance Service and National Statistical Office was analyzed in this ecological study. Urologist density was defined by the number of urologists per 100,000 individuals. National patterns of urologist density were mapped graphically at the county level using GIS software. To control the time sequence, regression analysis with fitted line plot was conducted. The difference of distribution of urologist density was analyzed by ANCOVA. Urologists density showed an uneven distribution according to county characteristics (metropolitan cities vs. nonmetropolitan cities vs. rural areas; mean square=102.329, P<0.001) and also according to year (mean square=9.747, P=0.048). Regression analysis between metropolitan and non-metropolitan cities showed significant difference in the change of urologists per year (P=0.019). Metropolitan cities vs. rural areas and non-metropolitan cities vs. rural areas showed no differences. Among the factors, the presence of training hospitals was the affecting factor for the uneven distribution of urologist density (P<0.001). Uneven distribution of urologists in Korea likely originated from the relatively low urologist density in rural areas. However, considering the time sequencing data from 2007 to 2012, there was a difference between the increase of urologist density in metropolitan and non-metropolitan cities. PMID:26539009

  14. Geographic Distribution of Urologists in Korea, 2007 to 2012

    PubMed Central

    Song, Yun Seob; Shim, Sung Ryul; Jung, Insoo; Sun, Hwa Yeon; Song, Soo Hyun; Kwon, Soon-Sun; Ko, Young Myoung

    2015-01-01

    The adequacy of the urologist work force in Korea has never been investigated. This study investigated the geographic distribution of urologists in Korea. County level data from the National Health Insurance Service and National Statistical Office was analyzed in this ecological study. Urologist density was defined by the number of urologists per 100,000 individuals. National patterns of urologist density were mapped graphically at the county level using GIS software. To control the time sequence, regression analysis with fitted line plot was conducted. The difference of distribution of urologist density was analyzed by ANCOVA. Urologists density showed an uneven distribution according to county characteristics (metropolitan cities vs. nonmetropolitan cities vs. rural areas; mean square=102.329, P<0.001) and also according to year (mean square=9.747, P=0.048). Regression analysis between metropolitan and non-metropolitan cities showed significant difference in the change of urologists per year (P=0.019). Metropolitan cities vs. rural areas and non-metropolitan cities vs. rural areas showed no differences. Among the factors, the presence of training hospitals was the affecting factor for the uneven distribution of urologist density (P<0.001).Uneven distribution of urologists in Korea likely originated from the relatively low urologist density in rural areas. However, considering the time sequencing data from 2007 to 2012, there was a difference between the increase of urologist density in metropolitan and non-metropolitan cities. PMID:26539009

  15. Comprehensive Monitoring for Heterogeneous Geographically Distributed Storage

    NASA Astrophysics Data System (ADS)

    Ratnikova, N.; Karavakis, E.; Lammel, S.; Wildish, T.

    2015-12-01

    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.

  16. Comprehensive Monitoring for Heterogeneous Geographically Distributed Storage

    SciTech Connect

    Ratnikova, N.; Karavakis, E.; Lammel, S.; Wildish, T.

    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.

  17. Geographic Distribution of Federal Funds in 1985.

    ERIC Educational Resources Information Center

    Dubin, Elliott J.

    During the 1980s, federal spending for procurement, particularly defense procurement, retirement and survivors' benefits, medical benefits, and agricultural assistance payments grew dramatically, while spending for grants and salaries and wages lagged. But, the overall distribution of funding between metropolitan and nonmetropolitan areas remained…

  18. Correlation Assessment of Climate and Geographic Distribution of Tuberculosis Using Geographical Information System (GIS)

    PubMed Central

    BEIRANVAND, Reza; KARIMI, Asrin; DELPISHEH, Ali; SAYEHMIRI, Kourosh; SOLEIMANI, Samira; GHALAVANDI, Shahnaz

    2016-01-01

    Background: Tuberculosis (TB) spread pattern is influenced by geographic and social factors. Nowadays Geographic Information System (GIS) is one of the most important epidemiological instrumentation identifying high-risk population groups and geographic areas of TB. The aim of this study was to determine the correlation between climate and geographic distribution of TB in Khuzestan Province using GIS during 2005–2012. Methods: Through an ecological study, all 6363 patients with definite diagnosis of TB from 2005 until the end of September 2012 in Khuzestan Province, southern Iran were diagnosed. Data were recorded using TB- Register software. Tuberculosis incidence based on the climate and the average of annual rain was evaluated using GIS. Data were analyzed through SPSS software. Independent t-test, ANOVA, Linear regression, Pearson and Eta correlation coefficient with a significance level of less than 5% were used for the statistical analysis. Results: The TB incidence was different in various geographic conditions. The highest mean of TB cumulative incidence rate was observed in extra dry areas (P= 0.017). There was a significant inverse correlation between annual rain rate and TB incidence rate (R= −0.45, P= 0.001). The lowest TB incidence rate (0–100 cases per 100,000) was in areas with the average of annual rain more than 1000 mm (P= 0.003). Conclusion: The risk of TB has a strong relationship with climate and the average of annual rain, so that the risk of TB in areas with low annual rainfall and extra dry climate is more than other regions. Services and special cares to high-risk regions of TB are recommended. PMID:27057526

  19. Application of geographic information system in distribution power network automation

    NASA Astrophysics Data System (ADS)

    Wei, Xianmin

    2011-02-01

    Geographic information system (GIS) is the computer system in support of computer software with collection, storage, management, retrieval and comprehensive analysis of a variety of geospatial information, with various forms output data and graphics products. This paper introduced GIS data organization and its main applications in distribution power network automation, including both offline and online, and proposed component-based system development model and the need to establish WEBGIS and reliability.

  20. The geographic distribution of mammography resources in Mississippi

    PubMed Central

    Nichols, Elizabeth N.; Bradley, Denae L.; Zhang, Xu; Faruque, Fazlay; Duhé, Roy J.

    2014-01-01

    OBJECTIVE: To determine whether the availability of mammography resources affected breast cancer incidence rates, stage of disease at initial diagnosis, mortality rates and/or mortality-to-incidence ratios throughout Mississippi. METHODS: Mammography facilities were geocoded and the numbers of residents residing within a thirty minute drive of a mammography facility were calculated. Other data were extracted from the Mississippi Cancer Registry, the U.S. Census, and the Mississippi Behavioral Risk Factor Surveillance Survey (BRFSS). RESULTS & DISCUSSION: There were no statistically-significant differences between breast cancer incidence rates in Black versus White females in Mississippi; however, there were significant differences in the use of mammography, percentages of advanced-stage initial diagnoses, mortality rates, and mortality-to-incidence ratios, where Black females fared worse in each category. No statistically-significant correlations were observed between breast cancer outcomes and the availability of mammography facilities. The use of mammography was negatively correlated with advanced stage of disease at initial diagnosis. By combining Black and White subsets, a correlation between mammography use and improved survival was detected; this was not apparent in either subset alone. There was also a correlation between breast cancer mortality-to-incidence ratios and the percentage of the population living below the poverty level. CONCLUSIONS: The accessibility and use of mammography resources has a greater impact on breast cancer in Mississippi than does the geographic resource distribution per se. Therefore, intensified mammography campaigns to reduce the percentage of advanced-stage breast cancers initially diagnosed in Black women, especially in communities with high levels of poverty, are warranted in Mississippi. PMID:24678379

  1. Geographical distribution of Dermacentor marginatus and Dermacentor reticulatus in Europe.

    PubMed

    Rubel, Franz; Brugger, Katharina; Pfeffer, Martin; Chitimia-Dobler, Lidia; Didyk, Yuliya M; Leverenz, Sandra; Dautel, Hans; Kahl, Olaf

    2016-02-01

    The goal of this paper is to present up-to-date maps depicting the geographical distribution of Dermacentor species in Europe based on georeferenced sampling sites. Therefore, a dataset was compiled, resulting in 1286 D. marginatus (Sulzer, 1776) and 1209 D. reticulatus (Fabricius, 1794) locations. Special emphasis is given to the region of the European Alps depicting a presumable climate barrier of the mountains and to overlaps in the distribution of both species as well as on the situation in eastern European countries. For the latter newly described Dermacentor findings comprise 59 locations in Romania and 62 locations in Ukraine. The geographical distributions of both species in Europe range from Portugal to Ukraine (and continue to the east of Kazakhstan). Although it is well known that D. marginatus is adapted to a warmer and drier climate at more southern latitudes and D. reticulatus to a moderately moist climate at more northern latitudes, the distribution limits of both species were not well known. Here, the northern and southern distribution limits for both species in Europe, as determined from the georeferenced database, were specified for D. marginatus by the belt of 33-51° N latitude and for D. reticulatus by the belt of 41-57° N latitude. Thus, overlapping species distributions were found between 41° N and 51° N. PMID:26552893

  2. A survey of the geographic distribution of Ophiocordyceps sinensis.

    PubMed

    Li, Yi; Wang, Xiao-Liang; Jiao, Lei; Jiang, Yi; Li, Hui; Jiang, Si-Ping; Lhosumtseiring, Ngarong; Fu, Shen-Zhan; Dong, Cai-Hong; Zhan, Yu; Yao, Yi-Jian

    2011-12-01

    Ophiocordyceps sinensis is one of the best known fungi in Traditional Chinese Medicine. Many efforts have been devoted to locating the production areas of this species resulting in various reports; however, its geographic distribution remains incompletely understood. Distribution of O. sinensis at the county level is clarified in this work based on both a literature search and fieldwork. More than 3600 publications related to O. sinensis were investigated, including scientific papers, books, and online information. Herbarium specimens of O. sinensis and field collections made by this research group during the years 2000-2010 were examined to verify the distribution sites. A total of 203 localities for O. sinensis have been found, of which 106 are considered as confirmed distribution sites, 65 as possible distribution sites, 29 as excluded distribution sites and three as suspicious distribution sites. The results show that O. sinensis is confined to the Tibetan Plateau and its surrounding regions, including Tibet, Gansu, Qinghai, Sichuan, and Yunnan provinces in China and in certain areas of the southern flank of the Himalayas, in the countries of Bhutan, India and Nepal, with 3,000 m as the lowest altitude for the distribution. The fungus is distributed from the southernmost site in Yulong Naxi Autonomous County in northwestern Yunnan Province to the northernmost site in the Qilian Mountains in Qilian County, Qinghai Province, and from the east edge of the Tibetan Plateau in Wudu County, Gansu Province to the westernmost site in Uttarakhand, India. The clarification of the geographic distribution of O. sinensis will lay the foundation for conservation and sustainable use of the species. PMID:22203553

  3. Geographical distribution of pelagic decapod shrimp in the Atlantic Ocean.

    PubMed

    Judkins, David C

    2014-01-01

    Ninety-one species of pelagic decapod shrimp were identified in 938 midwater-trawl collections taken between 1963 and 1974 from the North and South Atlantic. Distributional maps are provided for the most frequently occurring species. Nighttime abundance of most species was greatest within the upper 200 m. Degree of geographical overlap was estimated using the geometric mean of the proportion of joint occurrences with a value ≥ 0.5 deemed significant. Geographical distributions tended to be unique, and only 31 species had values ≥ 0.5 with one or more other species. Species within genera and within phylogenetic subgroups of Sergia were generally parapatric or partially overlapping in distribution. Five geographical groupings of co-occurring species across genera were identified: Subpolar-Temperate, Southern Hemisphere, Central, Tropical, Eastern Tropical and Western Tropical. The two species of the Southern Hemisphere group are circumpolar at temperate latitudes. The 12 species of the Central group occurred throughout the subtropical and tropical North and South Atlantic. The eight species of the Tropical group occurred broadly across the equatorial Atlantic and Caribbean with ranges usually extending into the Gulf of Mexico and northward in the Gulf Stream. The two species of the Western Tropical group occurred most often in the western tropics, but there were scattered occurrences at subtropical latitudes. The four species of the Eastern Tropical group were endemic to the Mauritanian Upwelling and the Angola-Benguela Frontal zones off western Africa. Two of the three species in the Subpolar-Temperate group had bipolar distributions, and all three occurred in the Mediterranean and in the Mauritanian Upwelling zone. Most Central, Tropical and Western Tropical species were present in the in the Gulf of Mexico. The 10 species from the Mediterranean were a mixture of Subpolar-Temperate, Central and benthopelagic species. Patterns of distribution in Atlantic pelagic

  4. Effect of geographical distributions on the nutrient composition, phytochemical profile and antioxidant activity of Morus nigra.

    PubMed

    Khattak, Khanzadi Fatima; Rahman, Tajur Rahman

    2015-09-01

    Recent worldwide inclination for the consumption of natural compounds has extremely augmented the significance of persistent quality of plant materials. Consequently, there is an escalating scientific concern in the impact of geographical distributions of the plants on their chemical constituents, physical characteristics and biological activities. The current study was carried out to see the effect of geographical locations on the nutrient composition, mineral contents, phytochemical profile and free radical scavenging activity of Morus nigra fruit. The samples were collected from five different locations of Khyber Pakhtunkhwa, which included districts of D. I. Khan, Karak, Peshawar, Swabi and Swat. The results revealed the considerable impact of geographical locations on the levels of proximate nutrient and selected minerals. Likewise, the concentrations of phenolic, flavonoid, anthocyanin and alkaloidal contents varied significantly (p<0.05) with respect to their geographical distributions. The physicochemical characteristic, extraction yields and DPPH scavenging activity of the samples also showed strong link with the sites of their cultivation. The data suggest that geographical distributions affect the levels of phytochemicals and conversely their biological activities. These variations must be taken into consideration while utilizing raw plant materials for industrial applications and traditional therapies. PMID:26408872

  5. Mapping the Geographical Distribution of Lymphatic Filariasis in Zambia

    PubMed Central

    Mwase, Enala T.; Stensgaard, Anna-Sofie; Nsakashalo-Senkwe, Mutale; Mubila, Likezo; Mwansa, James; Songolo, Peter; Shawa, Sheila T.; Simonsen, Paul E.

    2014-01-01

    Background Past case reports have indicated that lymphatic filariasis (LF) occurs in Zambia, but knowledge about its geographical distribution and prevalence pattern, and the underlying potential environmental drivers, has been limited. As a background for planning and implementation of control, a country-wide mapping survey was undertaken between 2003 and 2011. Here the mapping activities are outlined, the findings across the numerous survey sites are presented, and the ecological requirements of the LF distribution are explored. Methodology/Principal findings Approximately 10,000 adult 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 presence, and to predict potential suitable habitats over unsurveyed areas. Of note, areas associated with human modification of the landscape appeared to play an important role for the general presence of LF, whereas temperature (measured as averaged seasonal land surface temperature) seemed 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 and start-up of geographically targeted and cost-effective LF control in Zambia. PMID:24587466

  6. Geographical distributions of lake trout strains stocked in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Schaner, Ted

    1996-01-01

    Geographical distributions of lake trout (Salvelinus namaycush) stocked at seven locations in U.S. waters and at four locations in Canadian waters of Lake Ontario were determined from fish caught with gill nets in September in 17 areas of U.S. waters and at 10 fixed locations in Canadian waters in 1986-95. For fish of a given strain stocked at a given location, geographical distributions were not different for immature males and immature females or for mature males and mature females. The proportion of total catch at the three locations nearest the stocking location was higher for mature fish than for immature fish in all 24 available comparisons (sexes combined) and was greater for fish stocked as yearlings than for those stocked as fingerlings in all eight comparisons. Mature fish were relatively widely dispersed from stocking locations indicating that their tendency to return to stocking locations for spawning was weak, and there was no appreciable difference in this tendency among strains. Mature lake trout were uniformly distributed among sampling locations, and the strain composition at stocking locations generally reflected the stocking history 5 to 6 years earlier. Few lake trout moved across Lake Ontario between the north and south shores or between the eastern outlet basin and the main lake basin. Limited dispersal from stocking sites supports the concept of stocking different genetic strains in various parts of the lake with the attributes of each strain selected to match environmental conditions in the portion of the lake where it is stocked.

  7. The geographic distribution of foreigners in West Germany.

    PubMed

    O'loughlin, J

    1985-08-01

    A review of the geographic distribution of the 5 million foreigners resident primarily in the urban areas of the Federal Republic of Germany is presented. "Economic trend surface and mixed space-time interaction models were chosen to analyse the changing distribution from 1964 to 1981." The results suggest that the settlement of foreigners in the 1960s was primarily influenced by job opportunities, whereas immigrants in the 1970s were more spatially diffused down the urban hierarchy. In 1981, "first-order spatial and temporal interaction or contagion effects are significant in determining the settlement pattern. The general south to north latitudinal settlement trend is weakening over time as migration responds less to distance (intervening opportunity) and more to local economic factors, immigration legislation, family reunification, and local contagion effects." (summary in FRE, GER) PMID:12267307

  8. [New findings on the geographic distribution of the verrucarum group (Diptera: Psychodidae) in Colombia].

    PubMed

    Bejarano, Eduar Elías; Sierra, Diana; Vélez, Iván Darío

    2003-09-01

    The incrimination of sand flies belonging to verrucarum species group in the leishmaniasis transmission underscores the need for a detailed information on the geographical distribution of these species. The current listing adds 34 new records that extend significantly the knowledge of the geographical distribution of the verrucarum group in Colombia. The most important new records pertain to Lutzomyia spinicrassa in the tropical dry forest of the Atlantic coast, Lutzomyia ovallesi in the Orinoco and Amazon River watersheds regions of Colombia, and the sympatric occurrence of Lutzomyia spinicrassa and Lutzomyia quasitownsendi in the eastern chain of the Andes mountains. Additionally, the municipal and altitudinal distributions are compiled for 19 new species recorded for Colombia. The series townsendi of the verrucarum group generally restricted to premontane and lower montane zones based on distribution data on Lutzomyia longiflocosa, L. quasitownsendi, Lutzomyia sauroida, L. spinicrassa, Lutzomyia torvida, Lutzomyia townsendi and Lutzomyia youngi. The series verrucarum is distributed from the tropical lowland to the montane zones, and includes species with wide geographical range (Lutzomyia evansi, Lutzomyia columbiana, L. ovallesi, Lutzomyia nuneztovari, Lutzomyia nevesi), and species of highly endemic distribution (Lutzomyia andina, Lutzomyia disiuncta, Lutzomyia moralesi, Lutzomyia antioquiensis). Members of the series pia (Lutzomyia pia, Lutzomyia limafalcaoae) and the series serrana (Lutzomyia serrana) occur from the tropical lowlands to the lower montane zones. The altitudinal divergences may be intrinsically tied to speciation process, especially as it relates to the climatic and geologic events that have affected the flora and fauna of the Andean region. PMID:14582337

  9. Effort Drivers Estimation for Brazilian Geographically Distributed Software Development

    NASA Astrophysics Data System (ADS)

    Almeida, Ana Carina M.; Souza, Renata; Aquino, Gibeon; Meira, Silvio

    To meet the requirements of today’s fast paced markets, it is important to develop projects on time and with the minimum use of resources. A good estimate is the key to achieve this goal. Several companies have started to work with geographically distributed teams due to cost reduction and time-to-market. Some researchers indicate that this approach introduces new challenges, because the teams work in different time zones and have possible differences in culture and language. It is already known that the multisite development increases the software cycle time. Data from 15 DSD projects from 10 distinct companies were collected. The analysis shows drivers that impact significantly the total effort planned to develop systems using DSD approach in Brazil.

  10. Geographic distribution of wolbachial infections in mosquitoes from Thailand.

    PubMed

    Wiwatanaratanabutr, Itsanun

    2013-11-01

    Members of the genus Wolbachia are inherited intracellular bacterial endosymbionts that infect a diverse range of arthropods. Here I report the results of a survey of these endosymbionts in different mosquito species from six geographic regions of Northern, Northeastern, Western, Central, Eastern and Southern Thailand. Using gene amplification assays with wsp and groE gene primers, wolbachiae were detected in 999 mosquitoes representing 28 species of 1622 specimens collected representing 74 species of wild-caught mosquitoes from all regions of Thailand. Results using wsp primers were similar to those using groE primers in all cases. Wolbachiae had not been reported previously from five of the species tested, namely, Aedes lineatopennis, Aedes vexans, Aedes vittatus, Culex pallidothorax and Culex whitmorei. Infections were found in all major disease vector genera except Anopheles. These results indicate that wolbachial infections are distributed throughout many mosquito species in Thailand. PMID:23660513

  11. Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria)

    PubMed Central

    Averianov, Alexander

    2014-01-01

    Abstract The taxonomy, geographic distribution, and paleoenvironmental context of azhdarchid pterosaurs are reviewed. All purported pteranodontid, tapejarid, and azhdarchid specimens from the Cenomanian Kem Kem beds of Morocco are referred to a single azhdarchid taxon, Alanqa saharica. The four proposed autapomorphies of Eurazhdarcho langendorfensis from the lower Maastrichtian Sebeş Formation of Romania are based on misinterpretations of material and this taxon is likely a subjective junior synonym of Hatzegopteryx thambema. Among 54 currently reported azhdarchid occurrences (51 skeletal remains and 3 tracks) 13% are from lacustrine deposits, 17% from fluvial plain deposits, 17% from coastal plain deposits, 18% from estuarine and lagoonal deposits, and 35% from costal marine deposits. Azhdarchids likely inhabited a variety of environments, but were abundant near large lakes and rivers and most common in nearshore marine paleoenvironments. PMID:25152671

  12. Geographical distribution and temporal variation of rain acidity over China

    SciTech Connect

    Wen-Xing Wang; Yan-Bo Pang; Guo-An Ding

    1996-12-31

    In recent decade, large areas of acid rain have appeared in China. With the increasing emission of SO{sub 2} and NO{sub x} year by year, the acidity of precipitation has increased, and the acid rain area is expanding. Presently, the acid rain in China has become the third largest area of acid rain in the world, next to Europe and North America. The Chinese government took action against acid rain and planned a five-year National Acid Deposition Research Project. The space-time distribution and variation of rain acidity described in this paper is a part of this project. China is a large country. The area is almost equal to that of Europe. Its climate varies greatly and spans the tropics, subtropics, temperate and frigid zone. There is a varied topography including mountain, hilly country, desert and plain, on the other hand the distribution of anthropogenic sources are not even. All of the human and natural factors caused different chemical composition in different parts of China, the acidity of precipitation varies also. The acidity of the precipitation is the most important parameter in the acid rain research. In order to obtain the regional representative distribution of rain acidity, National Acidic Deposition Research Monitoring Network with 261 monitoring sites was established in 1992. This paper summarizes the rain acidity of 21355 precipitation samples, and gave the annual, seasonal, and the monthly pH contours. Results show that the acid rain area has expanded from the south during winter. Regional differences of monthly acid precipitation exists, generally, the rain acidity level is higher during summer and fall and lower during winter and spring in the northern provinces. The 9 opposite is the case in the southern provinces. The central areas are in a transitional situation. The geographical distribution and temporal variation of rain acidity are quite different from North America and Europe.

  13. OhioView: Distribution of Remote Sensing Data Across Geographically Distributed Environments

    NASA Technical Reports Server (NTRS)

    Ramos, Calvin T.

    1998-01-01

    Various issues associated with the distribution of remote sensing data across geographically distributed environments are presented in viewgraph form. Specific topics include: 1) NASA education program background; 2) High level architectures, technologies and applications; 3) LeRC internal architecture and role; 4) Potential GIBN interconnect; 5) Potential areas of network investigation and research; 6) Draft of OhioView data model; and 7) the LeRC strategy and roadmap.

  14. Geographic variation in cowbird distribution, abundance, and parasitism

    USGS Publications Warehouse

    Morrison, M.L.; Hahn, D.C.

    2002-01-01

    We evaluated geographical patterns in the abundance and distribution of Brown-headed Cowbirds (Molothrus ater), and in the frequency of cowbird parasitism, across North America in relation to habitat fragmentation. We found no distinctive parasitism patterns at the national or even regional scales, but the species is most abundant in the Great Plains, the heart of their original range, and least common in the southeastern U.S. This situation is dynamic, because both the Brown-headed and two other cowbird species are actively expanding their ranges in the southern U.S. We focused almost entirely in this paper on the Brown-headed Cowbird, because it is the only endemic North American cowbird, its distribution is much wider, and it has been much more intensively studied. We determined that landscape is the most meaningful unit of scale for comparing cowbird parasitism patterns as, for example, in comparisons of northeastern and central hardwood forests within agricultural matrices, and suburbanized areas versus western coniferous forests. We concluded that cowbird parasitism patterns were broadly similar within all landscapes. Even comparisons between prominently dissimilar landscapes, such as hardwoods in agriculture and suburbia versus coniferous forest, display a striking similarity in the responses of cowbirds. Our review clearly indicated that proximity of feeding areas is the key factor influencing presence and parasitism patterns within the landscape. We considered intensity of landscape fragmentation from forest-dominated landscapes altered in a forest management context to fragmentation characterized by mixed suburbanization or agricultural development. Our review consistently identified an inverse relationship between extent of forest cover across the landscape and cowbird presence. Invariably, the variation seen in parasitism frequencies within a region was at least partially explained as a response to changes in forest cover. The most salient geographic

  15. Remote sensing and geographic information system for appraisal of salt-affected soils in India.

    PubMed

    Singh, Gurbachan; Bundela, D S; Sethi, Madhurama; Lal, Khajanchi; Kamra, S K

    2010-01-01

    Quantification of the nature, extent, and spatial distribution of salt-affected soils (SAS) for India and the world is essential for planning and implementing reclamation programs in a timely and cost-effective manner for sustained crop production. The national extent of SAS for India over the last four decades was assessed by conventional and remote sensing approaches using diverse methodologies and class definitions and ranged from 6.0 to 26.1 million hectares (Mha) and 1.2 to 10.1 Mha, respectively. In 1966, an area of 6 Mha under SAS was first reported using the former approach. Three national estimates, obtained using remote sensing, were reconciled using a geographic information system, resulting in an acceptable extent of 6.73 Mha. Moderately and severely salt-encrusted lands having large contiguous area have been correctly mapped, but slightly salt-encrusted land having smaller affected areas within croplands has not been accurately mapped. Recent satellite sensors (e.g., Resourcesat-1, Cartosat-2, IKONOS-II, and RISAT-2), along with improved image processing techniques integrated with terrain and other spatial data using a geographic information system, are enabling mapping at large scale. Significant variations in salt encrustation at the surface caused by soil moisture, waterlogging conditions, salt-tolerant crops, and dynamics of subsurface salts present constraints in appraisal, delineation, and mapping efforts. The article provides an overview of development, identification, characterization, and delineation of SAS, past and current national scenarios of SAS using conventional and remote sensing approaches, reconciliation of national estimates, issues of SAS mapping, and future scope. PMID:20048289

  16. Geographic distribution of three alkaloid chemotypes of Croton lechleri.

    PubMed

    Milanowski, Dennis J; Winter, Rudolph E K; Elvin-Lewis, Memory P F; Lewis, Walter H

    2002-06-01

    Three known alkaloids, isoboldine (2), norisoboldine (1), and magnoflorine (8), have been isolated for the first time from Croton lechleri, a source of the wound healing latex "sangre de grado". An HPLC system was developed, and a large number of latex and leaf samples of C. lechleri from 22 sites in northern Peru and Ecuador were analyzed to gain an understanding of the natural variation in alkaloid content for the species. Up to six alkaloids were found to occur in the leaves including, in addition to those listed above, thaliporphine (3), glaucine (4), and taspine (9), whereas the latex contained only 9. Taspine (9) is the component that has been previously found to be responsible for the wound healing activity of C. lechleri latex, and its mean concentration throughout the range examined was found to be 9% of the latex by dry weight. In addition, three chemotypes are defined based on the alkaloid content of the leaves, and the geographic distribution of these chemotypes is discussed along with a quantitative analysis of the alkaloid content as a function of chemotype. PMID:12088421

  17. Geophilus pygmaeus (Chilopoda: Geophilidae): clarifying morphology, variation and geographic distribution.

    PubMed

    Peretti, Emiliano; Bonato, Lucio

    2016-01-01

    The European centipede Geophilus pygmaeus (Chilopoda: Geophilidae) has been known since 1880. It has been repeatedly reported since then and its validity has never been questioned. Nevertheless, a complete description of the species and an unambiguous diagnosis are still lacking. Based on the examination of one of the syntypes and > 110 specimens from 28 other localities, we provide here a full description and illustration of the morphology of G. pygmaeus and a revised and updated overview of the geographic range of the species. G. pygmaeus is less than 2 cm long, has 41-47 pairs of legs and differs from all other European species of Geophilus in a combination of characters including the shape of the forcipular apparatus and a unique arrangement of the coxal pores. G. pygmaeus is distributed through the Southern Limestone Alps, between the Bergamasque Prealps in the West and the Slovene Prealps in the East, and in the northernmost Dinarides. Published records from other European areas are actually erroneous or uncertain. PMID:27470821

  18. Geographic Distribution and Expansion of Human Lyme Disease, United States

    PubMed Central

    2015-01-01

    Lyme disease occurs in specific geographic regions of the United States. We present a method for defining high-risk counties based on observed versus expected number of reported human Lyme disease cases. Applying this method to successive periods shows substantial geographic expansion of counties at high risk for Lyme disease. PMID:26196670

  19. Geographic distribution of otolaryngologists in the United States.

    PubMed

    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. PMID:27304439

  20. Global geographic distribution of Trichinella species and genotypes.

    PubMed

    Feidas, Haralambos; Kouam, Marc K; Kantzoura, Vaia; Theodoropoulos, Georgios

    2014-08-01

    Maximum entropy ecological niche modeling was utilized to describe the global geographic distribution of Trichinella species and genotypes and to assess their invasive risk in new areas other than the ones currently known. Also, space-time scan statistic was utilized to identify global spatiotemporal clusters of infection. A database containing 3209 records for 12 species and genotypes identified at the International Trichinella Reference Center (ITRC) as well as climate, elevation, and land cover data extracted from various databases were used. Ecological niche modeling implemented in the Maxent program indicated new potential ranges for T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4), T. murrelli (T5), T6, T. papuae (T10), and T. zimbabwensis (T11). The area under the curve values for the test data of the models ranged from 0.901 to 0.998, indicating that the models were very good to excellent. The most important bioclimatic factor in modeling the ranges for T. spiralis (T1), T. nativa (T2), T. britovi (T3), T6, and T. zimbabwensis (T11) was temperature, for T. pseudospiralis (T4) and T. papuae (T10) was precipitation, and for T. murrelli (T5) was land cover. T. spiralis (T1), T. britovi (T3), and T. pseudospiralis (T4) had the same primary land cover which was "Grass Crops". The primary land covers were "Conifer Boreal Forest" for T. nativa (T2), "Cool Fields and Woods" for T. murrelli (T5), "Upland Tundra" for T6, "Tropical Rainforest" for T. papuae (T10), and "Crops and Town" for T. zimbabwensis (T11). The scan statistic analyses revealed the presence of significant spatiotemporal clusters (p<0.05) for T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4), T. murrelli (T5), T6, and T. nelsoni (T7). No significant clusters were found for T. papuae (T10) and T. zimbabwensis (T11). PMID:24951834

  1. Geographic distribution and dispersal of normapolles genera in North America

    USGS Publications Warehouse

    Tschudy, R.H.

    1981-01-01

    Normapolles pollen have been found in North America in Cretaceous and Lower Tertiary rocks from the eastern Atlantic Seaboard, the Mississippi embayment region and from the states and provinces from western North America as far north as the District of Mackenzie, Northwest Territories. Previous postulates relating to the Normapolles floral province (western Europe-eastern North America) were re-examined in the light of new finds of Normapolles genera in rocks from west of the Cretaceous epeiric seaway which separated the Normapolles province from the western North American Aquilapollenites province. A study of published occurrences of Normapolles genera and U.S. Geological Survey Denver Laboratory Normapolles records revealed that of the approximately 60 Normapolles genera recognized from western Europe, only 26 of these have been recognized from eastern North America. These data suggest that Normapolles-producing plants originated in western Europe and migrated to eastern North America prior to the opening of the north Atlantic seaway. Ten of these 26 genera also have been found in rocks from west of the Cretaceous epeiric seaway, suggesting that these genera were the only ones able to cross this barrier. At least six genera having Normapolles characteristics occur in eastern North America but have not yet been recorded from Europe. Two additional genera with Normapolles characteristics have been reported only from the Aquilapollenites province of western North America. Several discrepancies in the record need resolution, such as the latitudinal restriction of Thomsonipollis and Nudopollis to areas south 40??N latitude, the absence of records of Thomsonipollis east and north of central Georgia, and the absence of records of Kyandopollenites and Choanopollenites west of eastern Texas. These data show that the known boundaries of the Normapolles province are somewhat hazy and that firm conclusions regarding the geographic distribution and history of dispersal of

  2. Quantifying the effects of geographical and environmental factors on distribution of stream bacterioplankton within nature reserves of Fujian, China.

    PubMed

    Wang, Yongming; Yang, Jun; Liu, Lemian; Yu, Zheng

    2015-07-01

    Bacterioplankton are important components of freshwater ecosystems and play essential roles in ecological functions and processes; however, little is known about their geographical distribution and the factors influencing their ecology, especially in stream ecosystems. To examine how geographical and environmental factors affect the composition of bacterioplankton communities, we used denaturing gradient gel electrophoresis and clone sequencing to survey bacterioplankton communities in 31 samples of streamwater from seven nature reserves in Fujian province, southeast China. Our results revealed that dominant bacterioplankton communities exhibited a distinct geographical pattern. Further, we provided evidence for distance decay relationships in bacterioplankton community similarity and found similar community gradients in response to elevation and latitude. Both redundancy analyses and Mantel tests showed that bacterioplankton community composition was significantly correlated with both environmental (electrical conductivity, total phosphorus, and PO4-P) and geographical factors (latitude, longitude, and elevation). Variance partitioning further showed that the joint effect of geographical and environmental factors explained the largest proportion of the variation in distribution of bacterioplankton communities (13.6 %), followed by purely geographical factors (11.2 %), and purely environmental factors (0.6 %). The Betaproteobacteria were the most common taxa in the streams, followed by Firmicutes and Gammaproteobacteria. Therefore, our results suggest that the biogeographical patterns of stream bacterioplankton communities across the Fujian nature reserves are more influenced by geographical factors than by local physicochemical properties. PMID:25787217

  3. Epidemiology and Geographical Distribution of Enteric Protozoan Infections in Sydney, Australia

    PubMed Central

    Fletcher, Stephanie; Caprarelli, Graziella; Merif, Juan; Andresen, David; Hal, Sebastian Van; Stark, Damien; Ellis, John

    2014-01-01

    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 areas is needed. Significance for public health This research is significant since it provides the most recent epidemiological update on the common enteric protozoa affecting Australians. It reveals that enteric protozoa cause considerable disease burden in high risk city dwellers, and provides the evidence base for development of targeted

  4. [[Characterization of the potential geographical distribution area of parrot species in Yucatan Peninsula, Mexico].

    PubMed

    Plasencia Vázquez, Alexis Herminio; Escalona Segura, Griselda

    2014-12-01

    Psittacidae family is one of the most endangered groups in Mexico, since many of their habitats are disappearing. In this research, we characterized the land cover of the potential geographical distribu- tion area of eight extant parrot species within the Yucatan Peninsula. We used the Maximum Entropy algorithm (MaxEnt) and species historical records. To externally validate the models, we used presence and absence records from field observations (2010-2012). To characterize the distribution area, we used the vegetation and land use maps of INEGI Series IV (2007-2010). The models showed a good performance, according to the values of the area under the curve (AUC), which ranged between 0.88-0.95 with the training data and between 0.82-0.91 with test data. We located most of the species in sites where the models predicted their presence. In the Peninsula, over 76% of the parrots' potential geographical distribution area is forested, except for Amazona oratrix. The subhumid tropical forest is the best represented, and the livestock for land use. The most affected species within the Peninsula are: Amazona farinosa and A. oratrix. The Calakmul Biosphere Reserve is the most important area for parrots' protection in the Peninsula. Knowing the characteristics of distribution areas is an essential part in the establishment of parrots' conservation strategies. PMID:25720184

  5. Mycetoma in Iran: Causative Agents and Geographic Distribution

    PubMed Central

    Bassiri-Jahromi, Shahindokht

    2014-01-01

    Background: Mycetoma is a chronic granulomatous disease caused by true fungi (eumycetoma) or filamentous bacteria (actinomycetoma). It usually involves the subcutaneous tissue after a traumatic inoculation of the causative organism. We reviewed retrospectively 13 patients with mycetoma. Materials and Methods: This study reports the etiologic agents and distribution of mycetoma in 35 cases from 1994 to2009 in Iran. The diagnostic of mycetoma were confirmed by histopathology and direct preparation, culture techniques, and histopathology of granules and surgical biopsies, radiological examination of the affected site. Results: Mycetoma was identified in 35 patients of 168 suspected patients (20.8%). They occurred in 22 male and 13 females. Their ages ranged from 14 to 80 years. The duration of the disease ranged from two months to 38 years. Sixteen patients had eumycetoma, and 19 patients had actinomycetoma, one of them had mix infections by eumycetoma and actinomycetoma. The majority of the patients were from central and states in south and north of Iran. The feet were most affected site (65.7%) of the cases, followed by hands (25.7%), face (2.8%), and trunk (2.8%), and buttock (2.8%). Most patients (68.5%) were more than 40 year-old. The male to female ratio was 5:3. The disease was abundant among housewife in urban and farmer in rural area of Iran. The most common prevalent mycetoma agents in this study were Actinomyces sp. There was a history of risk factors in 28.6% of patients in this study. Conclusion: Mycetoma occasionally occurs particularly in the South, Central, and North of Iran, and seen most often in persons, who live in hot, humid climates. If there are risk factors for invasive fungal infections traumatic inoculation with any fungus may result in rapid local spread and systemic disease, often with fatal outcome. PMID:25284877

  6. Geographic information science: Contribution to understanding salt and sodium affected soils in the Senegal River Valley

    NASA Astrophysics Data System (ADS)

    Ndiaye, Ramatoulaye

    The Senegal River valley and delta (SRVD) are affected by long term climate variability. Indicators of these climatic shifts include a rainfall deficit, warmer temperatures, sea level rise, floods, and drought. These shifts have led to environmental degradation, water deficits, and profound effects on human life and activities in the area. Geographic Information Science (GIScience), including satellite-based remote sensing methods offer several advantages over conventional ground-based methods used to map and monitor salt-affected soil (SAS) features. This study was designed to assess the accuracy of information on soil salinization extracted from Landsat satellite imagery. Would available imagery and GIScience data analysis enable an ability to discriminate natural soil salinization from soil sodication and provide an ability to characterize the SAS trend and pattern over 30 years? A set of Landsat MSS (June 1973 and September 1979), Landsat TM (November 1987, April 1994 and November 1999) and ETM+ (May 2001 and March 2003) images have been used to map and monitor salt impacted soil distribution. Supervised classification, unsupervised classification and post-classification change detection methods were used. Supervised classifications of May 2001 and March 2003 images were made in conjunction field data characterizing soil surface chemical characteristics that included exchange sodium percentage (ESP), cation exchange capacity (CEC) and the electrical conductivity (EC). With this supervised information extraction method, the distribution of three different types of SAS (saline, saline-sodic, and sodic) was mapped with an accuracy of 91.07% for 2001 image and 73.21% for 2003 image. Change detection results confirmed a decreasing trend in non-saline and saline soil and an increase in saline-sodic and sodic soil. All seven Landsat images were subjected to the unsupervised classification method which resulted in maps that separate SAS according to their degree of

  7. The geographical distribution of underweight children in Africa.

    PubMed Central

    Nubé, Maarten; Sonneveld, Benjamin G. J. S.

    2005-01-01

    OBJECTIVE: To study geographical patterns of underweight children in Africa by combining information on prevalence with headcounts at a subnational level. METHODS: We used large-scale, nationally representative nutrition surveys, in particular the Demographic and Health Surveys and the Multiple Indicator Cluster Surveys, which have been designed, analysed and presented according to largely similar protocols, and which report at the national and subnational levels. FINDINGS: We found distinct geographical patterns in the occurrence of underweight children, which could be linked to factors such as agronomic and climatic conditions, population density and economic integration. CONCLUSION: Patterns of underweight children cross national borders suggesting that regional characteristics and interactions need to be considered when addressing malnutrition. PMID:16283053

  8. Widespread geographical distribution of mitochondrial haplotypes in rock-dwelling cichlid fishes from Lake Tanganyika.

    PubMed

    Meyer, A; Knowles, L L; Verheyen, E

    1996-06-01

    The spectacularly diverse cichlid fish species flocks of the East African Rift Lakes have elicited much debate on the potential evolutionary mechanisms responsible for the origin of these adaptive radiations. An historical perspective on population structure may offer insights into the processes driving population differentiation and possibly speciation. Here, we examine mitochondrial DNA (mtDNA) sequence variation in two endemic species of rock-dwelling cichlids, Simochromis babaulti and S. diagramma, from Lake Tanganyika. Phylogeographic analyses were used to infer what factors might have been important in the genetic structuring of Simochromis populations. Patterns of mtDNA differentiation in Simochromis were compared to those of other rock-dwelling cichlids to distinguish between competing hypotheses concerning the processes underlying their evolution. In striking contrast to previous findings, populations of Simochromis, even those separated by up to 300 km, were found to share mitochondrial DNA haplotypes. There is no correspondence between mtDNA genealogies and the geographical distribution of populations. Only S. babaulti, but not S. diagramma was found to have a significant association between genetic and geographic distance. These phylogeographic patterns suggest that the evolutionary effects of abiotic and biotic factors shaping population genetic structure may differ substantially even among closely related species of rock-dwelling cichlids. Physical events and barriers to gene flow that are believed to have had a major impact on the geographical distribution and intralacustrine speciation of Tropheus do not seem to have equally strongly affected its close relative Simochromis. These findings emphasize that no single mechanism can be responsible for the formation of population structure, speciation, and the adaptive radiation of all cichlid fishes. PMID:8688956

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

    SciTech Connect

    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.

  10. Sequence Variability and Geographic Distribution of Lassa Virus, Sierra Leone

    PubMed Central

    Stockelman, Michael G.; Moses, Lina M.; Park, Matthew; Stenger, David A.; Ansumana, Rashid; Bausch, Daniel G.; Lin, Baochuan

    2015-01-01

    Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone. PMID:25811712

  11. Molecular evidence of Burkholderia pseudomallei genotypes based on geographical distribution

    PubMed Central

    Zulkefli, Noorfatin Jihan; Mariappan, Vanitha; Vellasamy, Kumutha Malar; Chong, Chun Wie; Thong, Kwai Lin; Ponnampalavanar, Sasheela; Vadivelu, Jamuna

    2016-01-01

    . Hierarchical clustering using UniFrac distance suggested that the isolates from Australia were genetically distinct from the Asian isolates. Nevertheless, statistical significant differences were detected between isolates from Malaysia, Thailand and Australia. Discussion. Overall, PFGE showed higher discriminative power in clustering the nine Malaysian B. pseudomallei isolates and indicated its suitability for localized epidemiological study. Compared to MLST, CIM genes showed higher resolution in distinguishing those non-related strains and better clustering of strains from different geographical regions. A closer genetic relatedness of Malaysian isolates with all Asian strains in comparison to Australian strains was observed. This finding was supported by UniFrac analysis which resulted in geographical segregation between Australia and the Asian countries. PMID:26998408

  12. The Geographic Distribution of Human Y Chromosome Variation

    PubMed Central

    Hammer, M. F.; Spurdle, A. B.; Karafet, T.; Bonner, M. R.; Wood, E. T.; Novelletto, A.; Malaspina, P.; Mitchell, R. J.; Horai, S.; Jenkins, T.; Zegura, S. L.

    1997-01-01

    We examined variation on the nonrecombining portion of the human Y chromosome to investigate human evolution during the last 200,000 years. The Y-specific polymorphic sites included the Y Alu insertional polymorphism or ``YAP'' element (DYS287), the poly(A) tail associated with the YAP element, three point mutations in close association with the YAP insertion site, an A-G polymorphic transition (DYS271), and a tetranucleotide microsatellite (DYS19). Global variation at the five bi-allelic sites (DYS271, DYS287, and the three point mutations) gave rise to five ``YAP haplotypes'' in 60 populations from Africa, Europe, Asia, Australasia, and the New World (n = 1500). Combining the multi-allelic variation at the microsatellite loci (poly(A) tail and DYS19) with the YAP haplotypes resulted in a total of 27 ``combination haplotypes''. All five of the YAP haplotypes and 21 of the 27 combination haplotypes were found in African populations, which had greater haplotype diversity than did populations from other geographical locations. Only subsets of the five YAP haplotypes were found outside of Africa. Patterns of observed variation were compatible with a variety of hypotheses, including multiple human migrations and range expansions. PMID:9055088

  13. Potential Geographic Distribution of Hantavirus Reservoirs in Brazil

    PubMed Central

    de Oliveira, Stefan Vilges; Escobar, Luis E.; Peterson, A. Townsend; Gurgel-Gonçalves, Rodrigo

    2013-01-01

    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. PMID:24391989

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

    PubMed

    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. PMID:25198370

  15. Institutional issues affecting the integration and use of remotely sensed data and geographic information systems

    USGS Publications Warehouse

    Lauer, D.T.; Estes, J.E.; Jensen, J.R.; Greenlee, D.D.

    1991-01-01

    The developers as well as the users of remotely sensed data and geographic information system (GIS) techniques are associated with nearly all types of institutions in government, industry, and academia. Individuals in these various institutions often find the barriers to accepting remote sensing and GIS are not necessarily technical in nature, but can be attributed to the institutions themselves. Several major institutional issues that affect the technologies of remote sensing and GIS are data availability, data marketing and costs, equipment availability and costs, standards and practices, education and training, and organizational infrastructures. Not only are problems associated with these issues identified, but needs and opportunities also are discussed. -from Authors

  16. Geographical distribution of red and green Noctiluca scintillans

    NASA Astrophysics Data System (ADS)

    Harrison, P. J.; Furuya, K.; Glibert, P. M.; Xu, J.; Liu, H. B.; Yin, K.; Lee, J. H. W.; Anderson, D. M.; Gowen, R.; Al-Azri, A. R.; Ho, A. Y. T.

    2011-07-01

    The dinoflagellate Noctiluca scintillans is one of the most important and abundant red tide organisms and it is distributed world-wide. It occurs in two forms. Red Noctiluca is heterotrophic and fills the role of one of the microzooplankton grazers in the foodweb. In contrast, green Noctiluca contains a photosynthetic symbiont Pedinomonas noctilucae (a prasinophyte), but it also feeds on other plankton when the food supply is abundant. In this review, we document the global distribution of these two forms and include the first maps of their global distribution. Red Noctiluca occurs widely in the temperate to sub-tropical coastal regions of the world. It occurs over a wide temperature range of about 10°C to 25°C and at higher salinities (generally not in estuaries). It is particularly abundant in high productivity areas such as upwelling or eutrophic areas where diatoms dominate since they are its preferred food source. Green Noctiluca is much more restricted to a temperature range of 25°C-30°C and mainly occurs in tropical waters of Southeast Asia, Bay of Bengal (east coast of India), in the eastern, western and northern Arabian Sea, the Red Sea, and recently it has become very abundant in the Gulf of Oman. Red and green Noctiluca do overlap in their distribution in the eastern, northern and western Arabian Sea with a seasonal shift from green Noctiluca in the cooler winter convective mixing, higher productivity season, to red Noctiluca in the more oligotrophic warmer summer season.

  17. Data on the distribution of physical activities in the Shenzhen greenway network with volunteered geographic information.

    PubMed

    Liu, Kun; Siu, Kin Wai Michael; Gong, Yong Xi; Gao, Yuan; Lu, Dan

    2016-09-01

    This data presents the distribution of physical activities in the Shenzhen greenway network (GN) in January, April and July, 2014. The volunteered geographic on physical activity is overlaid with the greenways data, to describe the distribution of physical activities in the greenways. The data are summarized to show the distribution characteristics geographically from different aspects in Shenzhen, China. Data were used to explore the effect of the Shenzhen GN on supporting physical activities, "Where do networks really work? The effects of Shenzhen greenway network on supporting physical activities" (Liu et al., 2016) [2]. PMID:27257616

  18. Managing Communication among Geographically Distributed Teams: A Brazilian Case

    NASA Astrophysics Data System (ADS)

    Almeida, Ana Carina M.; de Farias Junior, Ivaldir H.; de S. Carneiro, Pedro Jorge

    The growing demand for qualified professionals is making software companies opt for distributed software development (DSD). At the project conception, communication and synchronization of information are critical factors for success. However problems such as time-zone difference between teams, culture, language and different development processes among sites could difficult the communication among teams. In this way, the main goal of this paper is to describe the solution adopted by a Brazilian team to improve communication in a multisite project environment. The purposed solution was based on the best practices described in the literature, and the communication plan was created based on the infrastructure needed by the project. The outcome of this work is to minimize the impact of communication issues in multisite projects, increasing productivity, good understanding and avoiding rework on code and document writing.

  19. Geographic distribution of human Blastocystis subtypes in South America.

    PubMed

    Ramírez, Juan David; Sánchez, Angie; Hernández, Carolina; Flórez, Carolina; Bernal, María Consuelo; Giraldo, Julio Cesar; Reyes, Patricia; López, Myriam Consuelo; García, Lineth; Cooper, Philip J; Vicuña, Yosselin; Mongi, Florencia; Casero, Rodolfo D

    2016-07-01

    Blastocystis is a cosmopolitan enteric protist colonizing probably more than 1 billion people. This protozoan exhibits genetic diversity and is subdivided into subtypes (STs). The aim of this study was to determine the distribution of Blastocystis STs in symptomatic and asymptomatic human samples from different countries of South America. A total of 346 fecal samples were genotyped by SSU rDNA showing ST1 (28.3%), ST2 (22.2%), ST3 (36.7%), ST4 (2%), ST5 (2.3%), ST6 (2%), ST7 (2.3%), ST8 (0.6%), ST12 (0.9%) and a novel ST (2.7%). These findings update the epidemiology of Blastocystis in South America and expand our knowledge of the phylogeographic differences exhibited by this stramenopile. PMID:27034056

  20. Geographical differentiation in floral traits across the distribution range of the Patagonian oil-secreting Calceolaria polyrhiza: do pollinators matter?

    PubMed Central

    Cosacov, Andrea; Cocucci, Andrea A.; Sérsic, Alicia N.

    2014-01-01

    Background and Aims The underlying evolutionary processes of pollinator-driven floral diversification are still poorly understood. According to the Grant–Stebbins model speciation begins with adaptive local differentiation in the response to spatial heterogeneity in pollinators. Although this crucial process links the micro- and macroevolution of floral adaptation, it has received little attention. In this study geographical phenotypic variation was investigated in Patagonian Calceolaria polyrhiza and its pollinators, two oil-collecting bee species that differ in body size and geographical distribution. Methods Patterns of phenotypic variation were examined together with their relationships with pollinators and abiotic factors. Six floral and seven vegetative traits were measured in 45 populations distributed across the entire species range. Climatic and edaphic parameters were determined for 25 selected sites, 2–16 bees per site of the most frequent pollinator species were captured, and a critical flower–bee mechanical fitting trait involved in effective pollination was measured. Geographical patterns of phenotypic and environmental variation were examined using uni- and multivariate analyses. Decoupled geographical variation between corolla area and floral traits related to the mechanical fit of pollinators was explored using a Mantel test. Key Results The body length of pollinators and the floral traits related to mechanical fit were strongly correlated with each other. Geographical variation of the mechanical-fit-related traits was decoupled from variation in corolla size; the latter had a geographical pattern consistent with that of the vegetative traits and was mainly affected by climatic gradients. Conclusions The results are consistent with pollinators playing a key role in shaping floral phenotype at a geographical scale and promoting the differentiation of two floral ecotypes. The relationship between the critical floral-fit-related trait and bee

  1. Fish geographic distribution range shifts as recorded in the eastern Mediterranean during the last 5 Ma

    NASA Astrophysics Data System (ADS)

    Agiadi, Konstantina; Karakitsios, Vasileios

    2013-04-01

    Marine fish species geographic distribution is known to reflect the individuals' response to changes in oceanic circulation, temperature, salinity, local geography, other species presence and/or abundance, food availability and other biotic and abiotic factors1. New and published records on the eastern Mediterranean fish, from the end of the Messinian salinity crisis to the present, are here examined, in correlation with palaeoenvironmental data, in order to draw conclusions regarding the abiotic parameters most affecting the fish distribution during the last 5 Ma in this area. This investigation shows that the environmental variables do not affect the fish fauna in a uniform way. Rather, three faunal components may be separated, each occupying a different depth range in the water column. Pelagic fish dwell for the most part on the uppermost 200 m, and their distribution seems to be affected mainly by climatic variability. Mesopelagic fish occupy mostly intermediate depths and their distribution is regulated by the prevailing water circulation patterns. Benthic and benthopelagic fish, which live close or in contact with the sea bottom, are mostly affected by the nature and depth of the substratum. Furthermore, examples from the Ionian2,3 and the Aegean Sea indicate that, during the last 5 Ma, large-scale range shifts, similar to those occurring today, frequently took place in this area. This observation significantly alters previously views on the stability of fish assemblages and the processes occurring today. Acknowledgments. This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund. References 1 Wooton RJ. 1998. Ecology of teleost fishes,Fish and Fisheries Series,24.Kluwers.392p. 2

  2. The geographical distribution of lymphatic filariasis infection in Malawi.

    PubMed

    Ngwira, Bagrey Mm; Tambala, Phillimon; Perez, A Maria; Bowie, Cameron; Molyneux, David H

    2007-01-01

    Mapping distribution of lymphatic filariasis (LF) is a prerequisite for planning national elimination programmes. Results from a nation wide mapping survey for lymphatic filariasis (LF) in Malawi are presented. Thirty-five villages were sampled from 23 districts excluding three districts (Karonga, Chikwawa and Nsanje) that had already been mapped and Likoma, an Island, where access was not possible in the time frame of the survey. Antigenaemia prevalence [based on immunochromatographic card tests (ICT)] ranged from 0% to 35.9%. Villages from the western side of the country and distant from the lake tended to be of lower prevalence. The exception was a village in Mchinji district on the Malawi-Zambia border where a prevalence of 18.2% was found. In contrast villages from lake shore districts [Salima, Mangochi, Balaka and Ntcheu (Bwanje valley)] and Phalombe had prevalences of over 20%.A national map is developed which incorporates data from surveys in Karonga, Chikwawa and Nsanje districts, carried out in 2000. There is a marked decline in prevalence with increasing altitude. Further analysis revealed a strong negative correlation (R2 = 0.7 p < 0.001) between altitude and prevalence. These results suggest that the lake shore, Phalombe plain and the lower Shire valley will be priority areas for the Malawi LF elimination programme. Implications of these findings as regards implementing a national LF elimination programme in Malawi are discussed. PMID:18047646

  3. Geographic Distribution of Healthy Resources and Adverse Pregnancy Outcomes.

    PubMed

    Young, Christopher; Laurent, Olivier; Chung, Judith H; Wu, Jun

    2016-08-01

    Objective To determine the risk of gestational diabetes (GDM) and preeclampsia associated with various community resources. Methods An ecological study was performed in Los Angeles and Orange counties in California. Fast food restaurants, supermarkets, grocery stores, gyms, health clubs and green space were identified using Google © Maps Extractor and through the Southern California Association of Government. California Birth Certificate data was used to identify cases of GDM and preeclampsia. Unadjusted and adjusted risk ratios were calculated using negative binomial regression. Results There were 9692 cases of GDM and 6288 cases of preeclampsia corresponding to incidences of 2.5 and 1.4 % respectively. The adjusted risk of GDM was reduced in zip codes with greater concentration of grocery stores [relative risk (RR) 0.95, 95 % confidence interval (CI) 0.92-0.99] and supermarkets (RR 0.94, 95 % CI 0.90-0.98). There were no significant relationships between preeclampsia and the concentration of fast food restaurants, grocery store, supermarkets or the amount of green space. Conclusion The distribution of community resources has a significant association with the risk of developing GDM but not preeclampsia. PMID:26994606

  4. Cyber Graph Queries for Geographically Distributed Data Centers

    SciTech Connect

    Berry, Jonathan W.; Collins, Michael; Kearns, Aaron; Phillips, Cynthia A.; Saia, Jared

    2015-05-01

    We present new algorithms for a distributed model for graph computations motivated by limited information sharing we first discussed in [20]. Two or more independent entities have collected large social graphs. They wish to compute the result of running graph algorithms on the entire set of relationships. Because the information is sensitive or economically valuable, they do not wish to simply combine the information in a single location. We consider two models for computing the solution to graph algorithms in this setting: 1) limited-sharing: the two entities can share only a polylogarithmic size subgraph; 2) low-trust: the entities must not reveal any information beyond the query answer, assuming they are all honest but curious. We believe this model captures realistic constraints on cooperating autonomous data centers. We have algorithms in both setting for s - t connectivity in both models. We also give an algorithm in the low-communication model for finding a planted clique. This is an anomaly- detection problem, finding a subgraph that is larger and denser than expected. For both the low- communication algorithms, we exploit structural properties of social networks to prove perfor- mance bounds better than what is possible for general graphs. For s - t connectivity, we use known properties. For planted clique, we propose a new property: bounded number of triangles per node. This property is based upon evidence from the social science literature. We found that classic examples of social networks do not have the bounded-triangles property. This is because many social networks contain elements that are non-human, such as accounts for a business, or other automated accounts. We describe some initial attempts to distinguish human nodes from automated nodes in social networks based only on topological properties.

  5. Geographic distribution of hepatitis C virus genotypes in Brazil.

    PubMed

    Campiotto, S; Pinho, J R R; Carrilho, F J; Da Silva, L C; Souto, F J D; Spinelli, V; Pereira, L M M B; Coelho, H S M; Silva, A O; Fonseca, J C; Rosa, H; Lacet, C M C; Bernardini, A P

    2005-01-01

    Brazil is a country of continental dimension with a population of different ethnic backgrounds. Thus, a wide variation in the frequencies of hepatitis C virus (HCV) genotypes is expected to occur. To address this point, 1,688 sequential samples from chronic HCV patients were analyzed. HCV-RNA was amplified by the RT-PCR from blood samples collected from 1995 to 2000 at different laboratories located in different cities from all Brazilian States. Samples were collected in tubes containing a gel separator, centrifuged in the site of collection and sent by express mail in a refrigerated container to Laboratório Bioquímico Jardim Paulista, São Paulo, SP, Brazil. HCV-RNA was extracted from serum and submitted to RT and nested PCR using standard procedures. Nested PCR products were submitted to cycle sequencing reactions without prior purification. Sequences were analyzed for genotype determination and the following frequencies were found: 64.9% (1,095) for genotype 1, 4.6% (78) for genotype 2, 30.2% (510) for genotype 3, 0.2% (3) for genotype 4, and 0.1% (2) for genotype 5. The frequencies of HCV genotypes were statistically different among Brazilian regions (P = 0.00017). In all regions, genotype 1 was the most frequent (51.7 to 74.1%), reaching the highest value in the North; genotype 2 was more prevalent in the Center-West region (11.4%), especially in Mato Grosso State (25.8%), while genotype 3 was more common in the South (43.2%). Genotypes 4 and 5 were rarely found and only in the Southeast, in São Paulo State. The present data indicate the need for careful epidemiological surveys throughout Brazil since knowing the frequency and distribution of the genotypes would provide key information for understanding the spread of HCV. PMID:15665987

  6. Application of a Random Walk Model to Geographic Distributions of Animal Mitochondrial DNA Variation

    PubMed Central

    Neigel, J. E.; Avise, J. C.

    1993-01-01

    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. PMID:8307331

  7. Predicting the potential geographical distribution of Rhodnius neglectus (Hemiptera, Reduviidae) based on ecological niche modeling.

    PubMed

    Gurgel-Goncalves, Rodrigo; Cuba, César Augusto Cuba

    2009-07-01

    Rhodnius neglectus is frequently found in palm trees and bird nests in sylvatic environments. However, adult specimens infected by Trypanosoma cruzi have been invading houses in central Brazil. Analyzing and predicting the geographical distribution of this species may improve vector surveillance strategies for Chagas disease. Ecological niche modeling using the genetic algorithm for rule-set production (GARP) was applied to predict the geographical distribution of R. neglectus from occurrence records and a set of 23 predictor variables (e.g., temperature, precipitation, altitude, and vegetation). Additionally, the geographical distribution of R. neglectus was compared with the geographical distribution of four species of palm trees and two species of birds from the study region. The models were able to predict, with high probability, the occurrence of R. neglectus as a regular (although nonendemic) species of the Cerrado biome in central Brazil. Caatinga, Amazonian savanna, Pantanal, and the Bolivian Chaco appear as areas with lower probabilities of potential occurrence for the species. A great overlap was observed between the distribution of R. neglectus, palm trees (Acrocomia aculeata and Syagrus oleracea), and birds (Phacellodomus ruber and Pseudoseisura cristata). By including new records for R. neglectus (from both sylvatic and domestic environments), our study showed a distribution increase toward the west and northeast areas of Brazil in the "diagonal of open/dry ecoregions of South America". These results should aid Chagas disease vector surveillance programs, given that household invasion by Rhodnius species maintains the risk of disease transmission and limits control strategies. PMID:19645302

  8. Geographical distribution of vampire bat-related cattle rabies in Brazil.

    PubMed

    Kobayashi, Yuki; Ogawa, Ai; Sato, Go; Sato, Tetsuo; Itou, Takuya; Samara, Samir I; Carvalho, Adolorata A B; Nociti, Darci P; Ito, Fumio H; Sakai, Takeo

    2006-10-01

    Seventy-seven rabies virus (RV) isolates originating from Brazilian cattle were genetically characterized. Partial nucleoprotein gene sequences of these isolates were phylogenetically and geographically analyzed. Cattle isolates, which clustered with the vampire bat-related RV group, were further subdivided into nine genetic subgroups. These subgroups were distributed widely in lowland regions, with some subgroups separated from each other by mountain ranges. In addition, separation of the groups in mountainous regions was correlated with altitude. These results indicate that cattle rabies is derived from several regionally-defined variants, which suggests that its geographical distribution is related to that of the vampire bat population. PMID:17085890

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

    PubMed

    Winck, G R; Almeida-Santos, P; Rocha, C F D

    2014-05-01

    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. PMID:25166318

  10. Geological factors affecting CO2 plume distribution

    USGS Publications Warehouse

    Frailey, S.M.; Leetaru, H.

    2009-01-01

    Understanding the lateral extent of a CO2 plume has important implications with regards to buying/leasing pore volume rights, defining the area of review for an injection permit, determining the extent of an MMV plan, and managing basin-scale sequestration from multiple injection sites. The vertical and lateral distribution of CO2 has implications with regards to estimating CO2 storage volume at a specific site and the pore pressure below the caprock. Geologic and flow characteristics such as effective permeability and porosity, capillary pressure, lateral and vertical permeability anisotropy, geologic structure, and thickness all influence and affect the plume distribution to varying degrees. Depending on the variations in these parameters one may dominate the shape and size of the plume. Additionally, these parameters do not necessarily act independently. A comparison of viscous and gravity forces will determine the degree of vertical and lateral flow. However, this is dependent on formation thickness. For example in a thick zone with injection near the base, the CO2 moves radially from the well but will slow at greater radii and vertical movement will dominate. Generally the CO2 plume will not appreciably move laterally until the caprock or a relatively low permeability interval is contacted by the CO2. Conversely, in a relatively thin zone with the injection interval over nearly the entire zone, near the wellbore the CO2 will be distributed over the entire vertical component and will move laterally much further with minimal vertical movement. Assuming no geologic structure, injecting into a thin zone or into a thick zone immediately under a caprock will result in a larger plume size. With a geologic structure such as an anticline, CO2 plume size may be restricted and injection immediately below the caprock may have less lateral plume growth because the structure will induce downward vertical movement of the CO2 until the outer edge of the plume reaches a spill

  11. Geographic Distribution of Industrial R&D Expenditures. Special Report. Surveys of Science Resources Series.

    ERIC Educational Resources Information Center

    National Science Foundation, Washington, DC. Div. of Science Resources Studies.

    State Governments throughout the country have taken steps to strengthen their economic bases by promoting growth of high-technology industries within their respective borders. A byproduct of this effort has been an increasing need for information on the geographic distribution of industrial research and development (R&D) activities in terms of…

  12. The Dermacentor (Acari, Ixodida, Ixodidae) of Mexico: hosts, geographical distribution and new records

    PubMed Central

    Guzmán-Cornejo, Carmen; Robbins, Richard G.; Guglielmone, Alberto A.; Montiel-Parra, Griselda; Rivas, Gerardo; Pérez, Tila María

    2016-01-01

    Abstract Distribution and host data from published literature and previously unpublished collection records are provided for all nine species of the Holarctic tick genus Dermacentor that are known to occur in Mexico, as well as two species that may occur there. Parasite-host and host-parasite lists are presented, together with a gazetteer of collection localities and their geographical coordinates. PMID:27110147

  13. The idiosyncrasies of place: geographic variation in the climate-distribution relationships of the American pika.

    PubMed

    Jeffress, Mackenzie R; Rodhouse, Thomas J; Ray, Chris; Wolff, Susan; Epps, Clinton W

    2013-06-01

    Although climate acts as a fundamental constraint on the distribution of organisms, understanding how this relationship between climate and distribution varies over a species' range is critical for addressing the potential impacts of accelerated climate change on biodiversity. Bioclimatic niche models provide compelling evidence that many species will experience range shifts under scenarios of global change, yet these broad, macroecological perspectives lack specificity at local scales, where unique combinations of environment, biota, and history conspire against generalizations. We explored how these idiosyncrasies of place affect the climate-distribution relationship of the American pika (Ochotona princeps) by replicating intensive field surveys across bioclimatic gradients in eight U.S. national parks. At macroecological scales, the importance of climate as a constraint on pika distribution appears unequivocal; forecasts suggest that the species' range will contract sharply in coming decades. However, the species persists outside of its modeled bioclimatic envelope in many locations, fueling uncertainty and debate over its conservation status. Using a Bayesian hierarchical approach, we modeled variation in local patterns of pika distribution along topographic position, vegetation cover, elevation, temperature, and precipitation gradients in each park landscape. We also accounted for annual turnover in site occupancy probabilities. Topographic position and vegetation cover influenced occurrence in all parks. After accounting for these factors, pika occurrence varied widely among parks along bioclimatic gradients. Precipitation by itself was not a particularly influential predictor. However, measures of heat stress appeared most influential in the driest parks, suggesting an interaction between the strength of climate effects and the position of parks along precipitation gradients. The combination of high elevation, cold temperatures, and high precipitation

  14. Spatially-Explicit Estimation of Geographical Representation in Large-Scale Species Distribution Datasets

    PubMed Central

    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

  15. Deficiencies in the simulation of the geographic distribution of climate types by global climate models

    NASA Astrophysics Data System (ADS)

    Zhang, Xianliang; Yan, Xiaodong

    2016-05-01

    The performances of General Circulation Models (GCMs) when checked with conventional methods (i.e. correlation, bias, root-mean-square error) can only be evaluated for each variable individually. The geographic distribution of climate type in GCM simulations, which reflects the spatial attributes of models and is related closely to the terrestrial biosphere, has not yet been evaluated. Thus, whether the geographic distribution of climate types was well simulated by GCMs was evaluated in this study for nine GCMs. The results showed that large areas of climate zones classified by the GCMs were allocated incorrectly when compared to the basic climate zones established by observed data. The percentages of wrong areas covered approximately 30-50 % of the total land area for most models. In addition, the temporal shift in the distribution of climate zones according to the GCMs was found to be inaccurate. Not only were the locations of shifts poorly simulated, but also the areas of shift in climate zones. Overall, the geographic distribution of climate types was not simulated well by the GCMs, nor was the temporal shift in the distribution of climate zones. Thus, a new method on how to evaluate the simulated distribution of climate types for GCMs was provided in this study.

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

    PubMed Central

    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

  17. Not enough there, too many here: understanding geographical imbalances in the distribution of the health workforce

    PubMed Central

    Dussault, Gilles; Franceschini, Maria Cristina

    2006-01-01

    Access to good-quality health services is crucial for the improvement of many health outcomes, such as those targeted by the Millennium Development Goals (MDGs) adopted by the international community in 2000. The health-related MDGs cannot be achieved if vulnerable populations do not have access to skilled personnel and to other necessary inputs. This paper focuses on the geographical dimension of access and on one of its critical determinants: the availability of qualified personnel. The objective of this paper is to offer a better understanding of the determinants of geographical imbalances in the distribution of health personnel, and to identify and assess the strategies developed to correct them. It reviews the recent literature on determinants, barriers and the effects of strategies that attempted to correct geographical imbalances, with a focus on empirical studies from developing and developed countries. An analysis of determinants of success and failures of strategies implemented, and a summary of lessons learnt, is included. PMID:16729892

  18. Genetic differentiation and post-glacial establishment of the geographical distribution in Aegilops caudata L.

    PubMed

    Ohta, S

    2000-08-01

    Aegilops caudata L. is a diploid wild relative of wheat distributed over the north-eastern Mediterranean from Greece to northern Iraq. To elucidate the geographical differentiation pattern, 35 accessions derived from the entire distribution area were crossed with four Tester strains. Pollen fertility in the F1 hybrids varied from 0 to 96.3% among cross combinations, closely correlating with the geographical regions where the parental accessions were collected. Based on the intraspecific hybrid sterility, the present distribution area of Ae. caudata was divided into two geographical regions effectively isolated by the mountainous region lying between West Anatolia and Central Anatolia. The western region is composed of Greece and West Anatolia, while the eastern region consists of Central Anatolia, South Anatolia, East Anatolia and northern Iraq. The present results and the facts from recent palaeopalynological works suggest that during the maximum glacial period from 18,000 BP to 16,000 BP, Ae. caudata occurred in the two isolated regions, i.e., the region surrounding the Aegean Sea and the western Levant or some sheltered habitats in the East Taurus/Zagros mountains arc, and that it migrated into Central and East Anatolia from the latter regions as the climate became warmer. Furthermore, it is also suggested that the Levant populations now occur in the eastern region of the distribution, while those occurring in the Aegean Sea region during the last glacial period now occupy the western region of the distribution. PMID:11126567

  19. Phlebotomine sand flies (Diptera: Psychodidae) transmitting visceral leishmaniasis and their geographical distribution in China: a review.

    PubMed

    Guan, Li-Ren; Zhou, Zheng-Bin; Jin, Chang-Fa; Fu, Qing; Chai, Jun-Jie

    2016-01-01

    After the existence of phlebotomine sand flies was first reported in China in 1910, the distribution of different species and their role in the transmission of visceral leishmaniasis (VL) have been extensively studied. Up until 2008, four species have been verified as vectors of VL, namely, Phlebotomus chinensis (Ph. sichuanensis), Ph. longiductus (Ph. chinensis longiductus), Ph. wui (Ph. major wui), and Ph. alexandri. The sand fly species vary greatly depending on the natural environments in the different geographic areas where they are endemic. Ph. chinensis is euryecious and adaptable to different ecologies, and is thus distributed widely in the plain, mountainous, and Loess Plateau regions north of the Yangtze River. Ph. longiductus is mainly distributed in ancient oasis areas south of Mt. Tianshan in the Xinjiang Uygur autonomous region. Ph. wui is the predominant species in deserts with Populus diversifolia and Tamarix vegetation in Xinjiang and the western part of the Inner Mongolia autonomous region. Finally, Ph. alexandri is steroecious and found only in stony desert areas, such as at the foot of the mountains in Xinjiang and the western Hexi Corridor, in Gansu province. This review summarized the relationship between the geographic distribution pattern of the four sand fly species and their geographical landscape in order to foster research on disease distribution and sand fly control planning. Furthermore, some problems that remained to be solved about vectors of VL in China were discussed. PMID:26906187

  20. Alpine bird distributions along elevation gradients: the consistency of climate and habitat effects across geographic regions.

    PubMed

    Chamberlain, Dan; Brambilla, Mattia; Caprio, Enrico; Pedrini, Paolo; Rolando, Antonio

    2016-08-01

    Many species have shown recent shifts in their distributions in response to climate change. Patterns in species occurrence or abundance along altitudinal gradients often serve as the basis for detecting such changes and assessing future sensitivity. Quantifying the distribution of species along altitudinal gradients acts as a fundamental basis for future studies on environmental change impacts, but in order for models of altitudinal distribution to have wide applicability, it is necessary to know the extent to which altitudinal trends in occurrence are consistent across geographically separated areas. This was assessed by fitting models of bird species occurrence across altitudinal gradients in relation to habitat and climate variables in two geographically separated alpine regions, Piedmont and Trentino. The ten species studied showed non-random altitudinal distributions which in most cases were consistent across regions in terms of pattern. Trends in relation to altitude and differences between regions could be explained mostly by habitat or a combination of habitat and climate variables. Variation partitioning showed that most variation explained by the models was attributable to habitat, or habitat and climate together, rather than climate alone or geographic region. The shape and position of the altitudinal distribution curve is important as it can be related to vulnerability where the available space is limited, i.e. where mountains are not of sufficient altitude for expansion. This study therefore suggests that incorporating habitat and climate variables should be sufficient to construct models with high transferability for many alpine species. PMID:27139426

  1. Geographic differences in the distribution of molecular subtypes of breast cancer in Brazil

    PubMed Central

    2014-01-01

    Background To compare the distribution of the intrinsic molecular subtypes of breast cancer based on immunohistochemical profile in the five major geographic regions of Brazil, a country of continental dimension, with a wide racial variation of people. Methods The study was retrospective observational. We classified 5,687 invasive breast cancers by molecular subtype based on immunohistochemical expression of estrogen-receptor (ER), progesterone-receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 proliferation index. Cases were classified as luminal A (ER and/or PR positive and HER2 negative, Ki-67 < 14%), luminal B (ER and/or PR positive, HER2 negative, and Ki-67 > 14%), triple-positive (ER and/or PR positive and HER2 positive), HER2-enriched (ER and PR negative, and HER2- positive), and triple-negative (TN) (ER negative, PR negative, and HER2- negative). Comparisons of the ages of patients and molecular subtypes between different geographic regions were performed. Results South and Southeast regions with a higher percentage of European ancestry and higher socioeconomic status presented with the highest proportion of luminal tumors. The North region presented with more aggressive subtypes (HER2-enriched and triple-negative), while the Central-West region predominated triple-positive carcinomas. The Northeast—a region with a high African influence—presented intermediate frequency of the different molecular subtypes. The differences persisted in subgroups of patients under and over 50 years. Conclusions The geographic regions differ according to the distribution of molecular subtypes of breast cancer. However, other differences, beside those related to African ancestry, such as socioeconomic, climatic, nutritional, and geographic, have to be considered to explain our results. The knowledge of the differences in breast cancer characteristics among the geographic regions may help to organize healthcare programs in large countries

  2. Understanding the geographic distributions of apomictic plants: a case for a pluralistic approach

    PubMed Central

    Hörandl, Elvira; Cosendai, Anne-Caroline; Temsch, Eva Maria

    2010-01-01

    Asexual organisms usually have larger, and in the Northern Hemisphere, more northern distributions than their sexual relatives. This phenomenon, called geographical parthenogenesis, has been attributed to predispositions in certain taxa, advantages of polyploidy and/or hybrid origin, advantages of uniparental reproduction, introgression of apomixis into sexuals, niche differentiation of clones, and biotic interactions. Here we focus on the role of uniparental reproduction in colonisation, and the importance of different developmental pathways, i.e. autonomous apomixis which does not require pollination and fertilisation of endosperm nuclei for successful seed set, and pseudogamous apomixis which does. A literature survey suggests that geographical parthenogenesis occurs frequently in species with autonomous apomixis, while the correlation with pseudogamy is poorly documented. However, taxonomic patterns (e.g. predominance of Asteraceae) and also methodological bias may influence estimates of frequencies of geographical parthenogenesis. We demonstrate that a flow cytometric seed screen (FCSS) is a powerful method for assessing pseudogamous vs. autonomous apomixis. We show that population genetic studies provide insights into the genetic diversity of apomicts, but do not give strong support for uniparental reproduction being the only explanation of geographical parthenogenesis. Molecular studies help elucidate the evolutionary and biogeographical history of apomictic complexes, and we conclude that multidisciplinary studies are needed to understand fully the phenomenon of geographical parthenogenesis. PMID:20936092

  3. Performance of Forest Bryophytes with Different Geographical Distributions Transplanted across a Topographically Heterogeneous Landscape

    PubMed Central

    Dahlberg, C. Johan; Ehrlén, Johan; Hylander, Kristoffer

    2014-01-01

    Most species distribution models assume a close link between climatic conditions and species distributions. Yet, we know little about the link between species' geographical distributions and the sensitivity of performance to local environmental factors. We studied the performance of three bryophyte species transplanted at south- and north-facing slopes in a boreal forest landscape in Sweden. At the same sites, we measured both air and ground temperature. We hypothesized that the two southerly distributed species Eurhynchium angustirete and Herzogiella seligeri perform better on south-facing slopes and in warm conditions, and that the northerly distributed species Barbilophozia lycopodioides perform better on north-facing slopes and in relatively cool conditions. The northern, but not the two southern species, showed the predicted relationship with slope aspect. However, the performance of one of the two southern species was still enhanced by warm temperatures. An important reason for the inconsistent results can be that microclimatic gradients across landscapes are complex and influenced by many climate-forcing factors. Therefore, comparing only north- and south-facing slopes might not capture the complexity of microclimatic gradients. Population growth rates and potential distributions are the integrated results of all vital rates. Still, the study of selected vital rates constitutes an important first step to understand the relationship between population growth rates and geographical distributions and is essential to better predict how climate change influences species distributions. PMID:25387233

  4. Types of geographical distribution of leaf beetles (Chrysomelidae) in Central Europe *

    PubMed Central

    Schmitt, Michael; Rönn, Thomas

    2011-01-01

    Abstract A comparison of the geographical distribution patterns of 647 species of Chrysomelidae in Central Europe revealed 13 types of distribution: (1) widely distributed, (2) southern, (3) southeastern, (4) southwestern, (5) northern, (6) eastern, (7) south east quarter, (8) south west quarter, (9) fragmented, (10) montane, (11) subalpine & alpine, (12) scattered, (13) unusual, and irregular patterns produced by insufficient data. Some of these distributions are trivial (e. g. northern, eastern, etc., alpine) but others are surprising. Some cannot be explained, e. g. the remarkable gaps in the distribution of Chrysolina limbata (Fabricius, 1775) and in Aphthona nonstriata (Goeze, 1777). Although our 63.000 records are necessarily tentative, we found that the distribution maps from these data reflect in many cases the common knowledge on the occurrence of leaf beetles in specific areas. PMID:22303107

  5. The Impact of Global Climate Change on the Geographic Distribution and Sustainable Harvest of Hancornia speciosa Gomes (Apocynaceae) in Brazil

    NASA Astrophysics Data System (ADS)

    Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira

    2016-04-01

    The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.

  6. The Impact of Global Climate Change on the Geographic Distribution and Sustainable Harvest of Hancornia speciosa Gomes (Apocynaceae) in Brazil.

    PubMed

    Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira

    2016-04-01

    The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy. PMID:26796699

  7. Ecological Niche Modeling for the Prediction of the Geographic Distribution of Cutaneous Leishmaniasis in Tunisia.

    PubMed

    Chalghaf, Bilel; Chlif, Sadok; Mayala, Benjamin; Ghawar, Wissem; Bettaieb, Jihène; Harrabi, Myriam; Benie, Goze Bertin; Michael, Edwin; Salah, Afif Ben

    2016-04-01

    Cutaneous leishmaniasis is a very complex disease involving multiple factors that limit its emergence and spatial distribution. Prediction of cutaneous leishmaniasis epidemics in Tunisia remains difficult because most of the epidemiological tools used so far are descriptive in nature and mainly focus on a time dimension. The purpose of this work is to predict the potential geographic distribution of Phlebotomus papatasi and zoonotic cutaneous leishmaniasis caused by Leishmania major in Tunisia using Grinnellian ecological niche modeling. We attempted to assess the importance of environmental factors influencing the potential distribution of P. papatasi and cutaneous leishmaniasis caused by L. major. Vectors were trapped in central Tunisia during the transmission season using CDC light traps (John W. Hock Co., Gainesville, FL). A global positioning system was used to record the geographical coordinates of vector occurrence points and households tested positive for cutaneous leishmaniasis caused by L. major. Nine environmental layers were used as predictor variables to model the P. papatasi geographical distribution and five variables were used to model the L. major potential distribution. Ecological niche modeling was used to relate known species' occurrence points to values of environmental factors for these same points to predict the presence of the species in unsampled regions based on the value of the predictor variables. Rainfall and temperature contributed the most as predictors for sand flies and human case distributions. Ecological niche modeling anticipated the current distribution of P. papatasi with the highest suitability for species occurrence in the central and southeastern part of Tunisian. Furthermore, our study demonstrated that governorates of Gafsa, Sidi Bouzid, and Kairouan are at highest epidemic risk. PMID:26856914

  8. Ecological Niche Modeling for the Prediction of the Geographic Distribution of Cutaneous Leishmaniasis in Tunisia

    PubMed Central

    Chalghaf, Bilel; Chlif, Sadok; Mayala, Benjamin; Ghawar, Wissem; Bettaieb, Jihène; Harrabi, Myriam; Benie, Goze Bertin; Michael, Edwin; Salah, Afif Ben

    2016-01-01

    Cutaneous leishmaniasis is a very complex disease involving multiple factors that limit its emergence and spatial distribution. Prediction of cutaneous leishmaniasis epidemics in Tunisia remains difficult because most of the epidemiological tools used so far are descriptive in nature and mainly focus on a time dimension. The purpose of this work is to predict the potential geographic distribution of Phlebotomus papatasi and zoonotic cutaneous leishmaniasis caused by Leishmania major in Tunisia using Grinnellian ecological niche modeling. We attempted to assess the importance of environmental factors influencing the potential distribution of P. papatasi and cutaneous leishmaniasis caused by L. major. Vectors were trapped in central Tunisia during the transmission season using CDC light traps (John W. Hock Co., Gainesville, FL). A global positioning system was used to record the geographical coordinates of vector occurrence points and households tested positive for cutaneous leishmaniasis caused by L. major. Nine environmental layers were used as predictor variables to model the P. papatasi geographical distribution and five variables were used to model the L. major potential distribution. Ecological niche modeling was used to relate known species' occurrence points to values of environmental factors for these same points to predict the presence of the species in unsampled regions based on the value of the predictor variables. Rainfall and temperature contributed the most as predictors for sand flies and human case distributions. Ecological niche modeling anticipated the current distribution of P. papatasi with the highest suitability for species occurrence in the central and southeastern part of Tunisian. Furthermore, our study demonstrated that governorates of Gafsa, Sidi Bouzid, and Kairouan are at highest epidemic risk. PMID:26856914

  9. Andean Condor (Vultur gryphus) in Ecuador: Geographic Distribution, Population Size and Extinction Risk.

    PubMed

    Naveda-Rodríguez, Adrián; Vargas, Félix Hernán; Kohn, Sebastián; Zapata-Ríos, Galo

    2016-01-01

    The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation. PMID:26986004

  10. Andean Condor (Vultur gryphus) in Ecuador: Geographic Distribution, Population Size and Extinction Risk

    PubMed Central

    Naveda-Rodríguez, Adrián; Vargas, Félix Hernán; Kohn, Sebastián; Zapata-Ríos, Galo

    2016-01-01

    The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation. PMID:26986004

  11. Mathematical Ecology Analysis of Geographical Distribution of Soybean-Nodulating Bradyrhizobia in Japan

    PubMed Central

    Saeki, Yuichi; Shiro, Sokichi; Tajima, Toshiyuki; Yamamoto, Akihiro; Sameshima-Saito, Reiko; Sato, Takashi; Yamakawa, Takeo

    2013-01-01

    We characterized the relationship between the genetic diversity of indigenous soybean-nodulating bradyrhizobia from weakly acidic soils in Japan and their geographical distribution in an ecological study of indigenous soybean rhizobia. We isolated bradyrhizobia from three kinds of Rj-genotype soybeans. Their genetic diversity and community structure were analyzed by PCR-RFLP analysis of the 16S–23S rRNA gene internal transcribed spacer (ITS) region with 11 Bradyrhizobium USDA strains as references. We used data from the present study and previous studies to carry out mathematical ecological analyses, multidimensional scaling analysis with the Bray-Curtis index, polar ordination analysis, and multiple regression analyses to characterize the relationship between soybean-nodulating bradyrhizobial community structures and their geographical distribution. The mathematical ecological approaches used in this study demonstrated the presence of ecological niches and suggested the geographical distribution of soybean-nodulating bradyrhizobia to be a function of latitude and the related climate, with clusters in the order Bj123, Bj110, Bj6, and Be76 from north to south in Japan. PMID:24240318

  12. Geographical distribution of pyrethroid resistance allele frequency in head lice (Phthiraptera: Pediculidae) from Argentina.

    PubMed

    Toloza, Ariel Ceferino; Ascunce, Marina S; Reed, David; Picollo, María Inés

    2014-01-01

    The human head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), is an obligate ectoparasite that causes pediculosis capitis and has parasitized humans since the beginning of humankind. Head louse infestations are widespread throughout the world and have been increasing since the early 1990s partially because of ineffective pediculicides. In Argentina, the overuse of products containing pyrethroids has led to the development of resistant louse populations. Pyrethroid insecticides act on the nervous system affecting voltage-sensitive sodium channels. Three point mutations at the corresponding amino acid sequence positions M815I, T917I, and L920F in the voltage-gated sodium channel gene are responsible for contributing to knockdown resistance (kdr). The management of pyrethroid resistance requires either early detection or the characterization of the mechanisms involved in head louse populations. In the current study, we estimated the distribution of kdr alleles in 154 head lice from six geographical regions of Argentina. Pyrethroid resistance kdr alleles were found in high frequencies ranging from 67 to 100%. Of these, 131 (85.1%) were homozygous resistant, 13 (8.4%) were homozygous susceptible, and 10 (6.5%) were heterozygous. Exact tests for the Hardy-Weinberg equilibrium for each location showed that genotype frequencies differed significantly from expectation in four of the six sites studied. These results show that pyrethroid resistance is well established reaching an overall frequency of 88%, thus close to fixation. With 30 yr of pyrethroid-based pediculicides use in Argentina, kdr resistance has evolved rapidly among these head louse populations. PMID:24605463

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

    PubMed Central

    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

  14. Reconstructing ecological niches and geographic distributions of caribou ( Rangifer tarandus) and red deer ( Cervus elaphus) during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Banks, William E.; d'Errico, Francesco; Peterson, A. Townsend; Kageyama, Masa; Colombeau, Guillaume

    2008-12-01

    A variety of approaches have been used to reconstruct glacial distributions of species, identify their environmental characteristics, and understand their influence on subsequent population expansions. Traditional methods, however, provide only rough estimates of past distributions, and are often unable to identify the ecological and geographic processes that shaped them. Recently, ecological niche modeling (ENM) methodologies have been applied to these questions in an effort to overcome such limitations. We apply ENM to the European faunal record of the Last Glacial Maximum (LGM) to reconstruct ecological niches and potential ranges for caribou ( Rangifer tarandus) and red deer ( Cervus elaphus), and evaluate whether their LGM distributions resulted from tracking the geographic footprint of their ecological niches (niche conservatism) or if ecological niche shifts between the LGM and present might be implicated. Results indicate that the LGM geographic ranges of both species represent distributions characterized by niche conservatism, expressed through geographic contraction of the geographic footprints of their respective ecological niches.

  15. Geographical distribution of adolescent body height with respect to effective day length in Japan: an ecological analysis.

    PubMed

    Yokoya, Masana; Shimizu, Hideyasu; Higuchi, Yukito

    2012-01-01

    The height of Japanese youth raised in the northern region tends to be greater than that of youth raised in the southern region; therefore, a geographical gradient in youth body height exists. Although this gradient has existed for about 100 years, the reasons for it remain unclear. Consideration of the nutritional improvement, economic growth, and intense migration that has occurred in this period indicates that it is probably the result of environmental rather than nutritional or genetic factors. To identify possible environmental factors, ecological analysis of prefecture-level data on the body size of 8- to 17-year-old youth averaged over a 13-year period (1996 to 2008) and Japanese mesh climatic data on the climatic variables of temperature, solar radiation, and effective day length (duration of photoperiod exceeding the threshold of light intensity) was performed. The geographical distribution of the standardized height of Japanese adolescents was found to be inversely correlated to a great extent with the distribution of effective day length at a light intensity greater than 4000 lx. The results of multiple regression analysis of effective day length, temperature, and weight (as an index of food intake) indicated that a combination of effective day length and weight was statistically significant as predictors of height in early adolescence; however, only effective day length was statistically significant as a predictor of height in late adolescence. Day length may affect height by affecting the secretion of melatonin, a hormone that inhibits sexual and skeletal maturation, which in turn induces increases in height. By affecting melatonin production, regional differences in the duration of the photoperiod may lead to regional differences in height. Exposure to light intensity greater than 4000 lx appears to be the threshold at which light intensity begins to affect the melatonin secretion of humans who spend much of their time indoors. PMID:23227226

  16. Variation in honey bee gut microbial diversity affected by ontogenetic stage, age and geographic location.

    PubMed

    Hroncova, Zuzana; Havlik, Jaroslav; Killer, Jiri; Doskocil, Ivo; Tyl, Jan; Kamler, Martin; Titera, Dalibor; Hakl, Josef; Mrazek, Jakub; Bunesova, Vera; Rada, Vojtech

    2015-01-01

    Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes) and Gilliamella apicola (Gammaproteobacteria 1). However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both of these stages may

  17. Variation in Honey Bee Gut Microbial Diversity Affected by Ontogenetic Stage, Age and Geographic Location

    PubMed Central

    Hroncova, Zuzana; Havlik, Jaroslav; Killer, Jiri; Doskocil, Ivo; Tyl, Jan; Kamler, Martin; Titera, Dalibor; Hakl, Josef; Mrazek, Jakub; Bunesova, Vera; Rada, Vojtech

    2015-01-01

    Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes) and Gilliamella apicola (Gammaproteobacteria 1). However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both of these stages may

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Genetic Diversity and Geographical Distribution of Indigenous Soybean-Nodulating Bradyrhizobia in the United States

    PubMed Central

    Shiro, Sokichi; Matsuura, Syota; Saiki, Rina; Sigua, Gilbert C.; Yamamoto, Akihiro; Umehara, Yosuke; Hayashi, Masaki

    2013-01-01

    We investigated the relationship between the genetic diversity of indigenous soybean-nodulating bradyrhizobia and their geographical distribution in the United States using nine soil isolates from eight states. The bradyrhizobia were inoculated on three soybean Rj genotypes (non-Rj, Rj2Rj3, and Rj4). We analyzed their genetic diversity and community structure by means of restriction fragment length polymorphisms of PCR amplicons to target the 16S-23S rRNA gene internal transcribed spacer region, using 11 USDA Bradyrhizobium strains as reference strains. We also performed diversity analysis, multidimensional scaling analysis based on the Bray-Curtis index, and polar ordination analysis to describe the structure and geographical distribution of the soybean-nodulating bradyrhizobial community. The major clusters were Bradyrhizobium japonicum Bj123, in the northern United States, and Bradyrhizobium elkanii, in the middle to southern regions. Dominance of bradyrhizobia in a community was generally larger for the cluster belonging to B. elkanii than for the cluster belonging to B. japonicum. The indigenous American soybean-nodulating bradyrhizobial community structure was strongly correlated with latitude. Our results suggest that this community varies geographically. PMID:23563944

  20. Sectorial and geographical contributions to summertime black carbon spatial distributions over the US

    NASA Astrophysics Data System (ADS)

    Carmichael, G. R.; Huang, M.; Kulkarni, S.; Streets, D. G.; Zhang, Q.

    2011-12-01

    Primary and secondary aerosols from local and distant sources in various emission sectors cause both direct and indirect effects on the climate system, and adversely affect human health and public welfare. Black carbon (BC), mainly generated from fossil-fuel combustion and biomass burning, absorbs light and warms the atmosphere. Its short lifetime and geographical/temporal variability indicate that the climate benefits of reduction in its emissions will be much faster than those reductions in carbon dioxide. In this study, we evaluate the ARCTAS global BC sector emission inventories using a regional chemical transport modeling system STEM and quantify sector (biomass burning, shipping, industrial, power, transportation and residential) contributions from local and distant sources to the BC spatial distributions (surface and vertical distributions, and total column amounts) over the continental US in summer 2008. The sector contributions are further summarized for ten EPA regions for comparison and contrast. Due to the increasing trend of BC emissions from outside of the North America in the past decade, we focus on western US regions that are sensitive to extra-regional pollutions. The estimated amount of transported BC is compared with previous studies and correlated with the tracer CO calculations to help study uncertainties. The increasing BC trend during 1990-2004 summer over the mountain regions was observed, opposite to the trend over the Pacific regions [Murphy et al., 2011]. To better understand these trends, statistical analysis is used to contrast the role of transported BC on these regions. Furthermore, the seasonal variations of the impacts of transported BC over the US are discussed regarding the transported amounts and pathways. Mitigation policies are suggested to consider the absolute concentrations for BC as well as its relative relationship with cooling aerosols (such as sulfate (SO4), nitrate (NO3), and organics), with special focus on

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    Labine, Meaghan A.; Green, Chris; Mak, Giselle; Xue, Lin; Nowatzki, Janet; Griffith, Jane; Minuk, Gerald Y.

    2015-01-01

    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. PMID:26633441

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

    SciTech Connect

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

    1995-09-01

    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.

  4. Geographic information system analysis on the distribution of patients visiting the periodontology department at a dental college hospital

    PubMed Central

    2016-01-01

    Purpose The aim of this study is to analyze and visualize the distribution of patients visiting the periodontology department at a dental college hospital, using a geographic information system (GIS) to utilize these data in patient care and treatment planning, which may help to assess the risk and prevent periodontal diseases. Methods Basic patient information data were obtained from Dankook University Dental Hospital, including the unit number, gender, date of birth, and address, down to the dong (neighborhood) administrative district unit, of 306,656 patients who visited the hospital between 2007 and 2014. The data of only 26,457 patients who visited the periodontology department were included in this analysis. The patient distribution was visualized using GIS. Statistical analyses including multiple regression, logistic regression, and geographically weighted regression were performed using SAS 9.3 and ArcGIS 10.1. Five factors, namely proximity, accessibility, age, gender, and socioeconomic status, were investigated as the explanatory variables of the patient distribution. Results The visualized patient data showed a nationwide scale of the patient distribution. The mean distance from each patient’s regional center to the hospital was 30.94±29.62 km and was inversely proportional to the number of patients from the respective regions. The distance from a regional center to the adjacent toll gate had various effects depending on the local distance from the hospital. The average age of the patients was 52.41±12.97 years. Further, a majority of regions showed a male dominance. Personal income had inconsistent results between analyses. Conclusions The distribution of patients is significantly affected by the proximity, accessibility, age, gender and socioeconomic status of patients, and the patients visiting the periodontology department travelled farther distances than those visiting the other departments. The underlying reason for this needs to be analyzed

  5. The European ALMA Regional Centre Network: A Geographically Distributed User Support Model

    NASA Astrophysics Data System (ADS)

    Hatziminaoglou, E.; Zwaan, M.; Andreani, P.; Barta, M.; Bertoldi, F.; Brand, J.; Gueth, F.; Hogerheijde, M.; Maercker, M.; Massardi, M.; Muehle, S.; Muxlow, Th.; Richards, A.; Schilke, P.; Tilanus, R.; Vlemmings, W.; Afonso, J.; Messias, H.

    2015-12-01

    In recent years there has been a paradigm shift from centralised to geographically distributed resources. Individual entities are no longer able to host or afford the necessary expertise in-house, and, as a consequence, society increasingly relies on widespread collaborations. Although such collaborations are now the norm for scientific projects, more technical structures providing support to a distributed scientific community without direct financial or other material benefits are scarce. The network of European ALMA Regional Centre (ARC) nodes is an example of such an internationally distributed user support network. It is an organised effort to provide the European ALMA user community with uniform expert support to enable optimal usage and scientific output of the ALMA facility. The network model for the European ARC nodes is described in terms of its organisation, communication strategies and user support.

  6. Distinct Geographical Distribution of the Miscanthus Accessions with Varied Biomass Enzymatic Saccharification

    PubMed Central

    Li, Xukai; Liao, Haofeng; Fan, Chunfen; Hu, Huizhen; Li, Ying; Li, Jing; Yi, Zili; Cai, Xiwen; Peng, Liangcai; Tu, Yuanyuan

    2016-01-01

    Miscanthus is a leading bioenergy candidate for biofuels, and it thus becomes essential to characterize the desire natural Miscanthus germplasm accessions with high biomass saccharification. In this study, total 171 natural Miscanthus accessions were geographically mapped using public database. According to the equation [P(H/L| East) = P(H/L∩East)/P(East)], the probability (P) parameters were calculated on relationships between geographical distributions of Miscanthus accessions in the East of China, and related factors with high(H) or low(L) values including biomass saccahrification under 1% NaOH and 1% H2SO4 pretreatments, lignocellulose features and climate conditions. Based on the maximum P value, a golden cutting line was generated from 42°25’ N, 108°22’ E to 22°58’ N, 116°28’ E on the original locations of Miscanthus accessions with high P(H|East) values (0.800–0.813), indicating that more than 90% Miscanthus accessions were originally located in the East with high biomass saccharification. Furthermore, the averaged insolation showed high P (H|East) and P(East|H) values at 0.782 and 0.754, whereas other climate factors had low P(East|H) values, suggesting that the averaged insolation is unique factor on Miscanthus distributions for biomass saccharification. In terms of cell wall compositions and wall polymer features, both hemicelluloses level and cellulose crystallinity (CrI) of Miscanthus accessions exhibited relative high P values, suggesting that they should be the major factors accounting for geographic distributions of Miscanthus accessions with high biomass digestibility. PMID:27532636

  7. Distinct Geographical Distribution of the Miscanthus Accessions with Varied Biomass Enzymatic Saccharification.

    PubMed

    Li, Xukai; Liao, Haofeng; Fan, Chunfen; Hu, Huizhen; Li, Ying; Li, Jing; Yi, Zili; Cai, Xiwen; Peng, Liangcai; Tu, Yuanyuan

    2016-01-01

    Miscanthus is a leading bioenergy candidate for biofuels, and it thus becomes essential to characterize the desire natural Miscanthus germplasm accessions with high biomass saccharification. In this study, total 171 natural Miscanthus accessions were geographically mapped using public database. According to the equation [P(H/L| East) = P(H/L∩East)/P(East)], the probability (P) parameters were calculated on relationships between geographical distributions of Miscanthus accessions in the East of China, and related factors with high(H) or low(L) values including biomass saccahrification under 1% NaOH and 1% H2SO4 pretreatments, lignocellulose features and climate conditions. Based on the maximum P value, a golden cutting line was generated from 42°25' N, 108°22' E to 22°58' N, 116°28' E on the original locations of Miscanthus accessions with high P(H|East) values (0.800-0.813), indicating that more than 90% Miscanthus accessions were originally located in the East with high biomass saccharification. Furthermore, the averaged insolation showed high P (H|East) and P(East|H) values at 0.782 and 0.754, whereas other climate factors had low P(East|H) values, suggesting that the averaged insolation is unique factor on Miscanthus distributions for biomass saccharification. In terms of cell wall compositions and wall polymer features, both hemicelluloses level and cellulose crystallinity (CrI) of Miscanthus accessions exhibited relative high P values, suggesting that they should be the major factors accounting for geographic distributions of Miscanthus accessions with high biomass digestibility. PMID:27532636

  8. Geographical, linguistic, and cultural influences on genetic diversity: Y-chromosomal distribution in Northern European populations.

    PubMed

    Zerjal, T; Beckman, L; Beckman, G; Mikelsaar, A V; Krumina, A; Kucinskas, V; Hurles, M E; Tyler-Smith, C

    2001-06-01

    We analyzed 10 Y-chromosomal binary markers in 363 males from 8 populations in Northern Europe and 5 Y microsatellites in 346 of these individuals. These populations can be grouped according to cultural, linguistic, or geographical criteria, and the groupings are different in each case. We can therefore ask which criterion best corresponds to the distribution of genetic variation. In an AMOVA analysis using the binary markers, 13% of the Y variation was found between populations, indicating a high level of differentiation within this small area. No significant difference was seen between the traditionally nomadic Saami and the neighboring, historically farming, populations. When the populations were divided into Uralic speakers and Indo-European speakers, 8% of the variation was found between groups, but when they were divided according to geographical location, 14% of the variation was between groups. Geographical factors have thus been the most important in limiting gene flow between these populations, but linguistic differences have also been important in the east. PMID:11371596

  9. Predicting the geographic distribution of a species from presence-only data subject to detection errors

    USGS Publications Warehouse

    Dorazio, Robert M.

    2012-01-01

    Several models have been developed to predict the geographic distribution of a species by combining measurements of covariates of occurrence at locations where the species is known to be present with measurements of the same covariates at other locations where species occurrence status (presence or absence) is unknown. In the absence of species detection errors, spatial point-process models and binary-regression models for case-augmented surveys provide consistent estimators of a species’ geographic distribution without prior knowledge of species prevalence. In addition, these regression models can be modified to produce estimators of species abundance that are asymptotically equivalent to those of the spatial point-process models. However, if species presence locations are subject to detection errors, neither class of models provides a consistent estimator of covariate effects unless the covariates of species abundance are distinct and independently distributed from the covariates of species detection probability. These analytical results are illustrated using simulation studies of data sets that contain a wide range of presence-only sample sizes. Analyses of presence-only data of three avian species observed in a survey of landbirds in western Montana and northern Idaho are compared with site-occupancy analyses of detections and nondetections of these species.

  10. Statistical sampling of the distribution of uranium deposits using geologic/geographic clusters

    USGS Publications Warehouse

    Finch, W.I.; Grundy, W.D.; Pierson, C.T.

    1992-01-01

    The concept of geologic/geographic clusters was developed particularly to study grade and tonnage models for sandstone-type uranium deposits. A cluster is a grouping of mined as well as unmined uranium occurrences within an arbitrary area about 8 km across. A cluster is a statistical sample that will reflect accurately the distribution of uranium in large regions relative to various geologic and geographic features. The example of the Colorado Plateau Uranium Province reveals that only 3 percent of the total number of clusters is in the largest tonnage-size category, greater than 10,000 short tons U3O8, and that 80 percent of the clusters are hosted by Triassic and Jurassic rocks. The distributions of grade and tonnage for clusters in the Powder River Basin show a wide variation; the grade distribution is highly variable, reflecting a difference between roll-front deposits and concretionary deposits, and the Basin contains about half the number in the greater-than-10,000 tonnage-size class as does the Colorado Plateau, even though it is much smaller. The grade and tonnage models should prove useful in finding the richest and largest uranium deposits. ?? 1992 Oxford University Press.

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

    PubMed

    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. PMID:24159689

  12. Geographic selection bias of occurrence data influences transferability of invasive Hydrilla verticillata distribution models.

    PubMed

    Barnes, Matthew A; Jerde, Christopher L; Wittmann, Marion E; Chadderton, W Lindsay; Ding, Jianqing; Zhang, Jialiang; Purcell, Matthew; Budhathoki, Milan; Lodge, David M

    2014-06-01

    Due to socioeconomic differences, the accuracy and extent of reporting on the occurrence of native species differs among countries, which can impact the performance of species distribution models. We assessed the importance of geographical biases in occurrence data on model performance using Hydrilla verticillata as a case study. We used Maxent to predict potential North American distribution of the aquatic invasive macrophyte based upon training data from its native range. We produced a model using all available native range occurrence data, then explored the change in model performance produced by omitting subsets of training data based on political boundaries. We also compared those results with models trained on data from which a random sample of occurrence data was omitted from across the native range. Although most models accurately predicted the occurrence of H. verticillata in North America (AUC > 0.7600), data omissions influenced model predictions. Omitting data based on political boundaries resulted in larger shifts in model accuracy than omitting randomly selected occurrence data. For well-documented species like H. verticillata, missing records from single countries or ecoregions may minimally influence model predictions, but for species with fewer documented occurrences or poorly understood ranges, geographic biases could misguide predictions. Regardless of focal species, we recommend that future species distribution modeling efforts begin with a reflection on potential spatial biases of available occurrence data. Improved biodiversity surveillance and reporting will provide benefit not only in invaded ranges but also within under-reported and unexplored native ranges. PMID:25360288

  13. Geographic selection bias of occurrence data influences transferability of invasive Hydrilla verticillata distribution models

    PubMed Central

    Barnes, Matthew A; Jerde, Christopher L; Wittmann, Marion E; Chadderton, W Lindsay; Ding, Jianqing; Zhang, Jialiang; Purcell, Matthew; Budhathoki, Milan; Lodge, David M

    2014-01-01

    Due to socioeconomic differences, the accuracy and extent of reporting on the occurrence of native species differs among countries, which can impact the performance of species distribution models. We assessed the importance of geographical biases in occurrence data on model performance using Hydrilla verticillata as a case study. We used Maxent to predict potential North American distribution of the aquatic invasive macrophyte based upon training data from its native range. We produced a model using all available native range occurrence data, then explored the change in model performance produced by omitting subsets of training data based on political boundaries. We also compared those results with models trained on data from which a random sample of occurrence data was omitted from across the native range. Although most models accurately predicted the occurrence of H. verticillata in North America (AUC > 0.7600), data omissions influenced model predictions. Omitting data based on political boundaries resulted in larger shifts in model accuracy than omitting randomly selected occurrence data. For well-documented species like H. verticillata, missing records from single countries or ecoregions may minimally influence model predictions, but for species with fewer documented occurrences or poorly understood ranges, geographic biases could misguide predictions. Regardless of focal species, we recommend that future species distribution modeling efforts begin with a reflection on potential spatial biases of available occurrence data. Improved biodiversity surveillance and reporting will provide benefit not only in invaded ranges but also within under-reported and unexplored native ranges. PMID:25360288

  14. Geographic distribution of arsenic and trace metals in lotic ecosystems of the Pampa Plain, Argentina.

    PubMed

    Rosso, Juan José; Troncoso, Juan José; Fernández Cirelli, Alicia

    2011-01-01

    In this paper, the geographic distribution of arsenic and other trace elements in surface waters of 39 lotic ecosystems of central Argentina was evaluated. Manganese and arsenic were the most conspicuous elements, being present in 82% and 59% of the sampled ecosystems of this region, respectively. As concentration averaged 113.69 μg L⁻¹ varying between 55 and 198 μg L⁻¹, other trace elements were hardly detected or not detected at all. It was remarkable the absence of detectable concentrations of anthropogenically derived metals as lead (Pb) and cadmium (Cd). PMID:21153802

  15. The UV index: definition, distribution and factors affecting it.

    PubMed

    Fioletov, Vitali; Kerr, James B; Fergusson, Angus

    2010-01-01

    The UV Index was introduced in Canada in 1992 in response to growing concerns about the potential increase of ultraviolet (UV) radiation due to ozone depletion. The index was adopted as a standard indicator of UV levels by the World Meteorological Organization and World Health Organization in 1994. This survey article gives an overview of the UV Index and the main features of its geographical distribution. UV index values are determined from measurements made by ground-based spectrometers, broad-band filter radiometers and multi-filter radiometers. Radiative transfer models are used to estimate UV Index values from other types of geophysical observations, primarily column ozone and cloud thickness. UV Index values can also be retrieved from satellite measurements of atmospheric ozone and cloud cover. Forecasts of UV Index values are now widely available and are intended to be used by the public as a guide to avoid excessive exposure to UV radiation. Over the US and Canada, mean noontime UV Index values in summer range from 1.5 in the Arctic to 11.5 over southern Texas and can be as high as 20 at high elevations in Hawaii. The UV Index is also often used to quantify UV levels in studies investigating the impact of UV on other biological and photochemical processes. Factors affecting the UV Index, such as the sun elevation, total amount of ozone in the atmosphere, cloud cover, reflection from snow and local pollution, are also discussed. Since its introduction in 1992, the UV Index has become a widely used parameter to characterize solar UV. Information about it can be useful for helping people avoid excessive levels of UV radiation. PMID:21033538

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

    PubMed Central

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

    2015-01-01

    Background 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. Methods 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. Results 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 <0.001; MRI-CT difference <0.001). For all three modalities, Gini coefficient steadily decreased (p for 2011-2005 difference: <0.001 for CT; 0.003 for MRI; and <0.001 for PET). The number of devices in old models (single-detector CT, MRI<1.5 tesla, and conventional PET) decreased, while that in new models (multi-detector CT, MRI≥1.5 tesla, and PET-CT) increased. Gini coefficient of the old models increased or remained unchanged (increase rate of 9%, 3%, and -1%; p for 2011-2008 difference <0.001, 0.072, and 0.562, respectively), while Gini coefficient of the new models decreased (-10%, -9%, and -10%; p for 2011-2008 difference <0.001, <0.001, and <0.001 respectively). Similar results were observed in terms of utilizations. Conclusions The more abundant a modality, the more equal the modality’s distribution. Any increase in the modality made its distribution more equal. The geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force. PMID:25946125

  17. Association Between Geographic Access to Cancer Care, Insurance, and Receipt of Chemotherapy: Geographic Distribution of Oncologists and Travel Distance

    PubMed Central

    Lin, Chun Chieh; Bruinooge, Suanna S.; Kirkwood, M. Kelsey; Olsen, Christine; Jemal, Ahmedin; Bajorin, Dean; Giordano, Sharon H.; Goldstein, Michael; Guadagnolo, B. Ashleigh; Kosty, Michael; Hopkins, Shane; Yu, James B.; Arnone, Anna; Hanley, Amy; Stevens, Stephanie; Hershman, Dawn L.

    2015-01-01

    Purpose Geographic access to care may be associated with receipt of chemotherapy but has not been fully examined. This study sought to evaluate the association between density of oncologists and travel distance and receipt of adjuvant chemotherapy for colon cancer within 90 days of colectomy. Patients and Methods Patients in the National Cancer Data Base with stage III colon cancer, diagnosed between 2007 and 2010, and age 18 to 80 years were selected. Generalized estimating equation clustering by hospital service area was conducted to examine the association between geographic access and receipt of oncology services, controlling for patient sociodemographic and clinical characteristics. Results Of 34,694 patients in the study cohort, 75.7% received adjuvant chemotherapy within 90 days of colectomy. Compared with travel distance less than 12.5 miles, patients who traveled 50 to 249 miles (odds ratio [OR], 0.87; P = .009) or ≥ 250 miles (OR, 0.36; P < .001) had decreased likelihood of receiving adjuvant chemotherapy. Density level of oncologists was not statistically associated with receipt of adjuvant chemotherapy (low v high density: OR, 0.98; P = .77). When stratifying analyses by insurance status, non–privately insured patients who resided in areas with low density of oncologists were less likely to receive adjuvant chemotherapy (OR, 0.85; P = .03). Conclusion Increased travel burden was associated with a decreased likelihood of receiving adjuvant chemotherapy, regardless of insurance status. Patients with nonprivate insurance who resided in low-density oncologist areas were less likely to receive adjuvant chemotherapy. If these findings are validated prospectively, interventions to decrease geographic barriers may improve the timeliness and quality of colon cancer treatment. PMID:26304878

  18. Water balance and locomotor performance in three species of neotropical toads that differ in geographical distribution.

    PubMed

    Titon, Braz; Navas, Carlos Arturo; Jim, Jorge; Gomes, Fernando Ribeiro

    2010-05-01

    Water availability in the environment is a fundamental factor in determining the limits of geographical distribution and the evolution of the physiological characters associated to water balance in anurans. In this paper, we compare some aspects of water balance and the sensitivity of locomotor performance to dehydration at different temperatures for three species of toads from the genus Rhinella, with different levels of dependence on forested environments. Results show patterns associated to interspecific differences in both geographical distribution and time of seasonal reproduction. Sensitivity of locomotor performance to dehydration was lower at low temperatures for R. icterica, the species that are reproductively active during winter and lower at intermediate temperatures for R. schneideri, the species that reproduces mostly during spring, suggesting a pattern of thermal adaptation of locomotor performance for these species. Otherwise, R. ornata, a species with broader reproductive season, shows high sensitivity of locomotor performance to dehydration at all temperatures tested, suggesting a stronger relation of breeding activity with patterns of rainfall than temperature variation. Furthermore, the low rates of water uptake of R. ornata may pose restrictions on the occupation of open areas by this species. PMID:20096361

  19. Relation between Water Balance and Climatic Variables Associated with the Geographical Distribution of Anurans

    PubMed Central

    Titon, Braz; Gomes, Fernando Ribeiro

    2015-01-01

    Amphibian species richness increases toward the equator, particularly in humid tropical forests. This relation between amphibian species richness and environmental water availability has been proposed to be a consequence of their high rates of evaporative water loss. In this way, traits that estimate water balance are expected to covary with climate and constrain a species’ geographic distribution. Furthermore, we predicted that coexisting species of anurans would have traits that are adapted to local hydric conditions. We compared the traits that describe water balance in 17 species of anurans that occur in the mesic Atlantic Forest and xeric Cerrado (savannah) habitats of Brazil. We predicted that species found in the warmer and dryer areas would show a lower sensitivity of locomotor performance to dehydration (SLPD), increased resistance to evaporative water loss (REWL) and higher rates of water uptake (RWU) than species restricted to the more mesic areas. We estimated the allometric relations between the hydric traits and body mass using phylogenetic generalized least squares. These regressions showed that REWL scaled negatively with body mass, whereas RWU scaled positively with body mass. Additionally, species inhabiting areas characterized by higher and more seasonally uniform temperatures, and lower and more seasonally concentrated precipitation, such as the Cerrado, had higher RWU and SLPD than species with geographical distributions more restricted to mesic environments, such as the Atlantic Forest. These results support the hypothesis that the interspecific variation of physiological traits shows an adaptation pattern to abiotic environmental traits. PMID:26469787

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

    PubMed Central

    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

  1. A geographic distribution database of Mononychellus mites (Acari, Tetranychidae) on cassava (Manihot esculenta)

    PubMed Central

    Vásquez-Ordóñez, Aymer Andrés; Parsa, Soroush

    2014-01-01

    Abstract The genus Mononychellus is represented by 28 herbivorous mites. Some of them are notorious pests of cassava (Manihot esculenta Crantz), a primary food crop in the tropics. With the exception of Mononychellus tanajoa (Bondar), their geographic distribution is not widely known. This article therefore reports observational and specimen-based occurrence data of Mononychellus species associated with cassava. The dataset consists of 1,513 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT’s Arthropod Reference Collection (CIATARC). Most of the records are from the genus’ native range in South America and were documented between 1980 and 2000. Approximately 61% of the records belong to M. tanajoa, 25% to M. caribbeanae (McGregor), 10% to M. mcgregori (Flechtmann and Baker) and 2% to M. planki (McGregor). The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF). PMID:24899828

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

    PubMed

    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. PMID:27410039

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

    PubMed Central

    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

  4. Topographic distribution of gastritis in heavy pigs investigated by a geographic information system approach.

    PubMed

    Pascotto, Ernesto; Capraro, Diego; Tomè, Paolo; Spanghero, Mauro

    2016-01-01

    The aim of this paper was to determine the topographic distribution of gastritis lesions in pigs through an open source geographic information system (GIS) software analysis. The stomachs of 146 Italian heavy pigs were collected at slaughter and subjected to macroscopic pathological examination of the internal mucosa. A total of 623 lesions were either classified as hyperplastic or follicular (97%) with the remaining minority of lesions categorised as atrophic and simple. The hyperplastic gastritis lesions had an average surface of 77.8 cm2 and were mainly located in an oval shaped area of the fundus region of the stomach near the Curvatura ventriculi major. The follicular gastritis lesions had generally a smaller surface (40.3 cm2) and were concentrated in two distinct small areas of the pyloric region. The GIS analysis provided the opportunity to produce useful maps showing the distribution and characteristics of gastritis in pigs. PMID:27245806

  5. Geographical ecology of the palms (Arecaceae): determinants of diversity and distributions across spatial scales

    PubMed Central

    Eiserhardt, Wolf L.; Svenning, Jens-Christian; Kissling, W. Daniel; Balslev, Henrik

    2011-01-01

    Background The palm family occurs in all tropical and sub-tropical regions of the world. Palms are of high ecological and economical importance, and display complex spatial patterns of species distributions and diversity. Scope This review summarizes empirical evidence for factors that determine palm species distributions, community composition and species richness such as the abiotic environment (climate, soil chemistry, hydrology and topography), the biotic environment (vegetation structure and species interactions) and dispersal. The importance of contemporary vs. historical impacts of these factors and the scale at which they function is discussed. Finally a hierarchical scale framework is developed to guide predictor selection for future studies. Conclusions Determinants of palm distributions, composition and richness vary with spatial scale. For species distributions, climate appears to be important at landscape and broader scales, soil, topography and vegetation at landscape and local scales, hydrology at local scales, and dispersal at all scales. For community composition, soil appears important at regional and finer scales, hydrology, topography and vegetation at landscape and local scales, and dispersal again at all scales. For species richness, climate and dispersal appear to be important at continental to global scales, soil at landscape and broader scales, and topography at landscape and finer scales. Some scale–predictor combinations have not been studied or deserve further attention, e.g. climate on regional to finer scales, and hydrology and topography on landscape and broader scales. The importance of biotic interactions – apart from general vegetation structure effects – for the geographic ecology of palms is generally underexplored. Future studies should target scale–predictor combinations and geographic domains not studied yet. To avoid biased inference, one should ideally include at least all predictors previously found important at the

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

    PubMed Central

    Neerinckx, Simon B; Peterson, Andrew T; Gulinck, Hubert; Deckers, Jozef; Leirs, Herwig

    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 using regional subsets of occurrence points demonstrate the models to be unable to predict independent occurrence points outside the training region accurately. Visualizations show plague to occur in diverse landscapes under wide ranges of environmental conditions. Conclusion We conclude that the typical focality of plague, observed in sub-Saharan Africa, is not related to fragmented and insular environmental conditions manifested at a coarse continental scale. However, our approach provides a foundation for testing hypotheses concerning focal distribution areas of plague and their links with historical and environmental factors. PMID:18947399

  7. At which geographic scale does ethnic diversity affect intra-neighborhood social capital?

    PubMed

    Sluiter, Roderick; Tolsma, Jochem; Scheepers, Peer

    2015-11-01

    The claim that ethnic diversity within the living environment would hamper bonding and bridging social capital has been studied extensively, producing highly inconsistent findings. We studied whether ethnic diversity effects depend on the geographic scale at which ethnic diversity is measured. We examined ethnic diversity effects on intra- and inter-ethnic contacts in the neighborhood, respectively on opposition to ethnic in- and out-group neighbors. Hypotheses were derived from Blau's meeting opportunities thesis and contact theory, ethnic competition theory, and constrict theory. Using information about 2545 Dutch respondents with their locality defined as egohoods and administrative units, we found that ethnic diversity effects vary with the geographic scale. Ethnic diversity of smaller localities is positively associated with bridging social capital. At larger scales, the findings are mixed: ethnic diversity is positively related to inter-ethnic contacts and opposition to out-group neighbors. Ethnic diversity of smaller localities is negatively related to bonding social capital. In contrast to often-made claims that diversity within the local context would matter most, estimates of diversity effects are not always stronger when diversity measures are aggregated to smaller geographic areas. PMID:26463536

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

    PubMed Central

    2013-01-01

    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. PMID:23281838

  9. Refined Geographic Distribution of the Oriental ALDH2*504Lys (nee 487Lys) Variant

    PubMed Central

    Li, Hui; Borinskaya, Svetlana; Yoshimura, Kimio; Kal’ina, Nina; Marusin, Andrey; Stepanov, Vadim A.; Qin, Zhendong; Khaliq, Shagufta; Lee, Mi-Young; Yang, Yajun; Mohyuddin, Aisha; Gurwitz, David; Mehdi, Syed Qasim; Rogaev, Evgeny; Jin, Li; Yankovsky, Nikolay K.; Kidd, Judith R.; Kidd, Kenneth K.

    2010-01-01

    Summary Mitochondrial aldehyde dehydrogenase (ALDH2) is one of the most important enzymes in human alcohol metabolism. The oriental ALDH2*504Lys variant functions as a dominant negative greatly reducing activity in heterozygotes and abolishing activity in homozygotes. This allele is associated with serious disorders such as alcohol liver disease, late onset Alzheimer disease, colorectal cancer, and esophageal cancer, and is best known for protection against alcoholism. Many hundreds of papers in various languages have been published on this variant, providing allele frequency data for many different populations. To develop a highly refined global geographic distribution of ALDH2*504Lys, we have collected new data on 4,091 individuals from 86 population samples and assembled published data on a total of 80,691 individuals from 366 population samples. The allele is essentially absent in all parts of the world except East Asia. The ALDH2*504Lys allele has its highest frequency in Southeast China, and occurs in most areas of China, Japan, Korea, Mongolia, and Indochina with frequencies gradually declining radially from Southeast China. As the indigenous populations in South China have much lower frequencies than the southern Han migrants from Central China, we conclude that ALDH2*504Lys was carried by Han Chinese as they spread throughout East Asia. Esophageal cancer, with its highest incidence in East Asia, may be associated with ALDH2*504Lys because of a toxic effect of increased acetaldehyde in the tissue where ingested ethanol has its highest concentration. While the distributions of esophageal cancer and ALDH2*504Lys do not precisely correlate, that does not disprove the hypothesis. In general the study of fine scale geographic distributions of ALDH2*504Lys and diseases may help in understanding the multiple relationships among genes, diseases, environments, and cultures. PMID:19456322

  10. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas

    PubMed Central

    Ortiz, Carlos S.; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-01-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  11. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas.

    PubMed

    Ortiz, Carlos S; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-09-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  12. The geographic distribution of potential risks posed by industrial toxic emissions in the U.S.

    PubMed

    Chakraborty, Jayajit

    2004-01-01

    The Toxics Release Inventory (TRI), compiled annually by the EPA, has emerged as the most comprehensive database on industrial toxic emissions in the U.S. While various risk indicators and pollutant weighting methods have been developed to compare TRI emissions, these measures are rarely used to examine the geography of potential risks posed by toxic emissions at the national scale. This article provides a geographic perspective on the evaluation of industrial pollution by exploring the spatial distribution of the potential health and environmental impacts of TRI emissions across the U.S. Six indicators of potential risk based on the impact benchmarking concept are used to characterize specific human health and environmental concerns: carcinogenic toxicity, noncarcinogenic toxicity, ozone depletion, global warming, smog formation and acid rain formation. Air emission data from the 2000 TRI are used to analyze the six potential impacts at the state level. The objectives are to: (a) examine and compare spatial variations in the distribution of these adverse impacts across the U.S.: and (b) identify the states facing the highest health and environmental risk from industrial toxic releases. The effect of differences in state area and population size on the distribution of the six potential impacts and state rankings for each category are also investigated. While Ohio and Texas receive the highest ranks in all risk categories, Louisiana and West Virginia represent the most "hazardous" states when emissions are weighted by state area and population. The results demonstrate the need to examine the geographic variability of different risk indicators that are used to evaluate TRI emissions, at multiple scales. PMID:15055926

  13. Assessment of the Geographic Distribution of Ornithodoros turicata (Argasidae): Climate Variation and Host Diversity

    PubMed Central

    Donaldson, Taylor G.; Pèrez de León, Adalberto A.; Li, Andrew I.; Castro-Arellano, Ivan; Wozniak, Edward; Boyle, William K.; Hargrove, Reid; Wilder, Hannah K.; Kim, Hee J.; Teel, Pete D.; Lopez, Job E.

    2016-01-01

    Background Ornithodoros turicata is a veterinary and medically important argasid tick that is recognized as a vector of the relapsing fever spirochete Borrelia turicatae and African swine fever virus. Historic collections of O. turicata have been recorded from Latin America to the southern United States. However, the geographic distribution of this vector is poorly understood in relation to environmental variables, their hosts, and consequently the pathogens they transmit. Methodology Localities of O. turicata were generated by performing literature searches, evaluating records from the United States National Tick Collection and the Symbiota Collections of Arthropods Network, and by conducting field studies. Maximum entropy species distribution modeling (Maxent) was used to predict the current distribution of O. turicata. Vertebrate host diversity and GIS analyses of their distributions were used to ascertain the area of shared occupancy of both the hosts and vector. Conclusions and Significance Our results predicted previously unrecognized regions of the United States with habitat that may maintain O. turicata and could guide future surveillance efforts for a tick capable of transmitting high–consequence pathogens to human and animal populations. PMID:26829327

  14. Rice cultivation and methane emission: Documentation of distributed geographic data sets

    NASA Technical Reports Server (NTRS)

    Matthews, Elaine; John, Jasmin; Fung, Inez

    1994-01-01

    High-resolution global data bases on the geographic and seasonal distribution of rice cultivation and associated methane emission, compiled by Matthews et al., were archived for public use. In addition to the primary data sets identifying location, seasonality, and methane emission from rice cultivation, a series of supporting data sets is included, allowing users not only to replicate the work of Matthews et al. but to investigate alternative cultivation and emission scenarios. The suite of databases provided, at 1 latitude by 1 longitude resolution for the globe, includes (1) locations of rice cultivation, (2) monthly arrays of actively growing rice areas, (3) countries and political subdivisions, and (4) monthly arrays of methane emission from rice cultivation. Ancillary data include (1) a listing, by country, of harvested rice areas and seasonal distribution of crop cycles and (2) country names and codes. Summary tables of zonal/monthly distributions of actively growing rice areas and of methane emissions are presented. Users should consult original publications for complete discussion of the data bases. This short paper is designed only to document formats of the distributed information and briefly describe the contents of the data sets and their initial application to evaluating the role of rice cultivation in the methane budget.

  15. Current Knowledge of Leishmania Vectors in Mexico: How Geographic Distributions of Species Relate to Transmission Areas

    PubMed Central

    González, Camila; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; Becker-Fauser, Ingeborg; Martínez-Meyer, Enrique; Peterson, A. Townsend; Sánchez-Cordero, Víctor

    2011-01-01

    Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico. PMID:22049037

  16. Geographic Distribution of Staphylococcus aureus Causing Invasive Infections in Europe: A Molecular-Epidemiological Analysis

    PubMed Central

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

    2010-01-01

    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. Methods and Findings 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. Conclusions 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

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

    PubMed

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

    2014-01-01

    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

  18. Geographical distribution of cryptic genetic types in the planktonic foraminifer Globigerinoides ruber.

    PubMed

    Aurahs, Ralf; Grimm, Guido W; Hemleben, Vera; Hemleben, Christoph; Kucera, Michal

    2009-04-01

    We present SSU rDNA data resolving the seasonal and geographical distribution of 'cryptic' genetic types of the planktonic foraminifer morphospecies Globigerinoides ruber in the eastern Atlantic Ocean and the Mediterranean Sea. Analysis of 262 sequences revealed the presence of five genetic types belonging to two distinct lineages. Although the morphospecies G. ruber occurs throughout the investigated region, its constituent 'cryptic' genetic types show a pattern of widespread exclusion, which is difficult to reconcile with the concept of ubiquitous dispersal. One of the newly discovered genetic types was exclusively found at stations in the Mediterranean Sea, possibly representing the smallest-scale example of endemism known in planktonic foraminifera. In general, our results suggest that the geographical scale of mutual exclusion between the genotypes is negatively correlated with their phylogenetic relatedness: the most similar and most recently diverged pair of siblings showed the strongest evidence for small-scale competitive exclusion. This pattern is consistent with the concept of niche partitioning, implying decreasing level of competition between genetic types with increasing degree of genetic divergence. PMID:19302352

  19. The Cucurbitaceae of India: Accepted names, synonyms, geographic distribution, and information on images and DNA sequences

    PubMed Central

    Renner, Susanne S.; Pandey, Arun K.

    2013-01-01

    Abstract The most recent critical checklists of the Cucurbitaceae of India are 30 years old. Since then, botanical exploration, online availability of specimen images and taxonomic literature, and molecular-phylogenetic studies have led to modified taxon boundaries and geographic ranges. We present a checklist of the Cucurbitaceae of India that treats 400 relevant names and provides information on the collecting locations and herbaria for all types. We accept 94 species (10 of them endemic) in 31 genera. For accepted species, we provide their geographic distribution inside and outside India, links to online images of herbarium or living specimens, and information on publicly available DNA sequences to highlight gaps in the current understanding of Indian cucurbit diversity. Of the 94 species, 79% have DNA sequences in GenBank, albeit rarely from Indian material. The most species-rich genera are Trichosanthes with 22 species, Cucumis with 11 (all but two wild), Momordica with 8, and Zehneria with 5. From an evolutionary point of view, India is of special interest because it harbors a wide range of lineages, many of them relatively old and phylogenetically isolated. Phytogeographically, the north eastern and peninsular regions are richest in species, while the Jammu Kashmir and Himachal regions have few Cucurbitaceae. Our checklist probably underestimates the true diversity of Indian Cucurbitaceae, but should help focus efforts towards the least known species and regions. PMID:23717193

  20. Epipactis helleborine shows strong mycorrhizal preference towards ectomycorrhizal fungi with contrasting geographic distributions in Japan.

    PubMed

    Ogura-Tsujita, Yuki; Yukawa, Tomohisa

    2008-09-01

    Epipactis helleborine (L.) Crantz, one of the most widespread orchid species, occurs in a broad range of habitats. This orchid is fully myco-heterotrophic in the germination stage and partially myco-heterotrophic in the adult stage, suggesting that a mycorrhizal partner is one of the key factors that determines whether E. helleborine successfully colonizes a specific environment. We focused on the coastal habitat of Japanese E. helleborine and surveyed the mycorrhizal fungi from geographically different coastal populations that grow in Japanese black pine (Pinus thunbergii Parl.) forests of coastal sand dunes. Mycorrhizal fungi and plant haplotypes were then compared with those from inland populations. Molecular phylogenetic analysis of large subunit rRNA sequences of fungi from its roots revealed that E. helleborine is mainly associated with several ectomycorrhizal taxa of the Pezizales, such as Wilcoxina, Tuber, and Hydnotrya. All individuals from coastal dunes were exclusively associated with a pezizalean fungus, Wilcoxina, which is ectomycorrhizal with pine trees growing on coastal dunes. Wilcoxina was not detected in inland forests. Coastal populations were indistinguishable from inland populations based on plant trnL intron haplotypes. Our results indicate that mycorrhizal association with geographically restricted pezizalean ectomycorrhizal fungi is a key control upon this orchid species' distribution across widely different forest habitats. PMID:18661158

  1. Reproductive biology and species geographical distribution in the Melastomataceae: a survey based on New World taxa

    PubMed Central

    dos Santos, Ana Paula Milla; Fracasso, Carla Magioni; Luciene dos Santos, Mirley; Romero, Rosana; Sazima, Marlies; Oliveira, Paulo Eugênio

    2012-01-01

    distributed. This is, to a certain extent, similar to the geographical parthenogenesis pattern of temperate apomictics. PMID:22751617

  2. Areas of endemism in the Neotropical region based on the geographical distribution of Tabanomorpha (Diptera: Brachycera).

    PubMed

    Klassa, Bruna; Santos, Charles Morphy D

    2015-01-01

    We aim to investigate the geographical distribution patterns of the infraorder Tabanomorpha and to delimit primary hypotheses of areas of endemism for the group in the Neotropical region. The results were compared to areas of endemism proposed in previous works for other taxa and particularly with the recent Morrone's regionalisation proposal. An endemicity analysis was performed with the ndm/vndm algorithm using 3826 occurrence records for 1361 species of Tabanomorpha. Areas of endemism were established based on a grid size of 6º and consensus cut-off of 42%. We identified 13 areas of endemism comprising five main components: Northern South America (NSA), Southeastern South America (SESA), Central America (CA), Brazilian Savannah (BS), Central Andes (CAn). In a broad sense, the main areas of endemism recovered for Tabanomorpha are congruent with the recent proposals of regionalisation for the Neotropical region. PMID:26701543

  3. Expanded Geographic Distribution and Clinical Characteristics of Ehrlichia ewingii Infections, United States

    PubMed Central

    Harris, Rebecca M.; Couturier, Brianne A.; Sample, Stephan C.; Coulter, Katrina S.; Casey, Kathleen K.

    2016-01-01

    Ehrlichiosis is a bacterial zoonosis, spread through the bites of infected ticks, that is most commonly caused in the United States by infection with the bacterium Ehrlichia chaffeensis. We retrospectively reviewed samples from an 18-month study of ehrlichiosis in the United States and found that E. ewingii was present in 10 (9.2%) of 109 case-patients with ehrlichiosis, a higher rate of infection with this species than had previously been reported. Two patients resided in New Jersey and Indiana, where cases have not been reported. All patients with available case histories recovered. Our study suggests a higher prevalence and wider geographic distribution of E. ewingii in the United States than previous reports have indicated. PMID:27089171

  4. Stress avoidance in a common annual: reproductive timing is important for local adaptation and geographic distribution.

    PubMed

    Griffith, T M; Watson, M A

    2005-11-01

    Adaptation to local environments may be an important determinant of species' geographic range. However, little is known about which traits contribute to adaptation or whether their further evolution would facilitate range expansion. In this study, we assessed the adaptive value of stress avoidance traits in the common annual Cocklebur (Xanthium strumarium) by performing a reciprocal transplant across a broad latitudinal gradient extending to the species' northern border. Populations were locally adapted and stress avoidance traits accounted for most fitness differences between populations. At the northern border where growing seasons are cooler and shorter, native populations had evolved to reproduce earlier than native populations in the lower latitude gardens. This clinal pattern in reproductive timing corresponded to a shift in selection from favouring later to earlier reproduction. Thus, earlier reproduction is an important adaptation to northern latitudes and constraint on the further evolution of this trait in marginal populations could potentially limit distribution. PMID:16313471

  5. Widespread geographic distribution of oral Candida dubliniensis strains in human immunodeficiency virus-infected individuals.

    PubMed Central

    Sullivan, D; Haynes, K; Bille, J; Boerlin, P; Rodero, L; Lloyd, S; Henman, M; Coleman, D

    1997-01-01

    Candida dubliniensis is a recently identified chlamydospore-positive yeast species associated with oral candidiasis in human immunodeficiency virus (HIV)-infected (HIV+) patients and is closely related to Candida albicans. Several recent reports have described atypical oral Candida isolates with phenotypic and genetic properties similar to those of C. dubliniensis. In this study 10 atypical chlamydospore-positive oral isolates from HIV+ patients in Switzerland, the United Kingdom, and Argentina and 1 isolate from an HIV-negative Irish subject were compared to reference strains of C. albicans and Candida stellatoidea and reference strains of C. dubliniensis recovered from Irish and Australian HIV+ individuals. All 11 isolates were phenotypically and genetically similar to and phylogenetically identical to C. dubliniensis. These findings demonstrate that the geographical distribution of C. dubliniensis is widespread, and it is likely that it is a significant constituent of the normal oral flora with the potential to cause oral candidiasis, particularly in immunocompromised patients. PMID:9157162

  6. Prevalence and geographic distribution of childhood obesity in China in 2005.

    PubMed

    Ji, Cheng Ye; Cheng, Tsung O

    2008-12-17

    China now joins the world epidemic of childhood obesity. Because of the large disparity of environmental conditions across various sub-populations, accurate prevalence of obesity/overweight cannot be estimated by population-based approaches. Using a resident-based targeted approach, we determined the geographical distribution of childhood obesity in China and analyzed the specific factors related to the increasing prevalence of obesity in each of its ten regions. An alarming increase in the prevalence of obesity has spread all over China, except for the poverty western rural areas. In 2005, the prevalence of combined childhood overweight and obesity in China reached 32.5% for males and 17.6% for females in the northern coastal big cities, suggesting that the obesity prevalence in some urban Chinese populations has approached that of the developed countries. The prevalence of obesity in the affluent rural sub-populations first exceeded that in some urban populations; then, as they learned their lessons and revised their lifestyles, the prevalence declined to a lower level approaching that of the transitional societies of other countries. The geographical distribution of obesity prevalence in China is mainly caused by the large disparity in the socioeconomic status related to dietary and lifestyle changes in modern China. Multiple and integrated interventions are urgently needed to halt the epidemic of childhood obesity by tackling its basic causes such as fast food, automobiles, television and lack of exercise. The differing prevalences in different regions of China offer an opportunity to reverse this alarming, growing epidemic of childhood obesity in the world's most populous country. PMID:18765165

  7. Phenotypic Plasticity Influences the Size, Shape and Dynamics of the Geographic Distribution of an Invasive Plant

    PubMed Central

    Pichancourt, Jean-Baptiste; van Klinken, Rieks D.

    2012-01-01

    Phenotypic plasticity has long been suspected to allow invasive species to expand their geographic range across large-scale environmental gradients. We tested this possibility in Australia using a continental scale survey of the invasive tree Parkinsonia aculeata (Fabaceae) in twenty-three sites distributed across four climate regions and three habitat types. Using tree-level responses, we detected a trade-off between seed mass and seed number across the moisture gradient. Individual trees plastically and reversibly produced many small seeds at dry sites or years, and few big seeds at wet sites and years. Bigger seeds were positively correlated with higher seed and seedling survival rates. The trade-off, the relation between seed mass, seed and seedling survival, and other fitness components of the plant life-cycle were integrated within a matrix population model. The model confirms that the plastic response resulted in average fitness benefits across the life-cycle. Plasticity resulted in average fitness being positively maintained at the wet and dry range margins where extinction risks would otherwise have been high (“Jack-of-all-Trades” strategy JT), and fitness being maximized at the species range centre where extinction risks were already low (“Master-of-Some” strategy MS). The resulting hybrid “Jack-and-Master” strategy (JM) broadened the geographic range and amplified average fitness in the range centre. Our study provides the first empirical evidence for a JM species. It also confirms mechanistically the importance of phenotypic plasticity in determining the size, the shape and the dynamic of a species distribution. The JM allows rapid and reversible phenotypic responses to new or changing moisture conditions at different scales, providing the species with definite advantages over genetic adaptation when invading diverse and variable environments. Furthermore, natural selection pressure acting on phenotypic plasticity is predicted to result in

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Transposable Element ISHp608 of Helicobacter pylori: Nonrandom Geographic Distribution, Functional Organization, and Insertion Specificity

    PubMed Central

    Kersulyte, Dangeruta; Velapatiño, Billie; Dailide, Giedrius; Mukhopadhyay, Asish K.; Ito, Yoshiyuki; Cahuayme, Lizbeth; Parkinson, Alan J.; Gilman, Robert H.; Berg, Douglas E.

    2002-01-01

    A new member of the IS605 transposable element family, designated ISHp608, was found by subtractive hybridization in Helicobacter pylori. Like the three other insertion sequences (ISs) known in this gastric pathogen, it contains two open reading frames (orfA and orfB), each related to putative transposase genes of simpler (one-gene) elements in other prokaryotes; orfB is also related to the Salmonella virulence gene gipA. PCR and hybridization tests showed that ISHp608 is nonrandomly distributed geographically: it was found in 21% of 194 European and African strains, 14% of 175 Bengali strains, 43% of 131 strains from native Peruvians and Alaska natives, but just 1% of 223 East Asian strains. ISHp608 also seemed more abundant in Peruvian gastric cancer strains than gastritis strains (9 of 14 versus 15 of 45, respectively; P = 0.04). Two ISHp608 types differing by ∼11% in DNA sequence were identified: one was widely distributed geographically, and the other was found only in Peruvian and Alaskan strains. Isolates of a given type differed by ≤2% in DNA sequence, but several recombinant elements were also found. ISHp608 marked with a resistance gene was found to (i) transpose in Escherichia coli; (ii) generate simple insertions during transposition, not cointegrates; (iii) insert downstream of the motif 5"-TTAC without duplicating target sequences; and (iv) require orfA but not orfB for its transposition. ISHp608 represents a widespread family of novel chimeric mobile DNA elements whose further analysis should provide new insights into transposition mechanisms and into microbial population genetic structure and genome evolution. PMID:11807059

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

    PubMed

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

    2016-04-01

    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. PMID:26792710

  11. Geographic Distribution and Ecology of Triatoma dimidiata (Hemiptera: Reduviidae) in Colombia.

    PubMed

    Parra-Henao, Gabriel; Angulo, Víctor Manuel; Osorio, Lisardo; Jaramillo-O, Nicolás

    2016-01-01

    Triatoma dimidiata Latreille is the second most important vector of Chagas' disease in Colombia and is found in urban and periurban areas. From January 2007 to June 2008, we performed field work in 8 departments, 18 municipalities, and 44 rural villages, covering most of its known distribution and all of its ecological zones in the country. The goal was to determine the geographical distribution, the ecology, and house infestation indices of T. dimidiata over its range and hence the Chagas' disease transmission risk. In Colombia, T. dimidiata occupies a wide variety of ecosystems, from transformed ecosystems in the Andean biome with shrub and xerofitic vegetation to very dense forests in the humid tropical forests in the Sierra Nevada of Santa Marta. According to genetic and ecological criteria, at least two T. dimidiata forms of this species are present: populations from the northwest of the country (Caribbean plains) are restricted to palm tree habitats, and domestic involvement is limited to sporadic visits because of attraction by light; and populations of the east region (Andean mountains) presenting a complex distributional pattern including sylvatic, peridomestic, and domiciliated ecotopes, and occupying a great variety of life zones. The latter population is of epidemiological importance due to the demonstrated migration and genetical flow of individuals among the different habitats. Control, therefore, must take into account its diversity of habitats. PMID:26487247

  12. Incidence, prevalence and geographic distribution of human alveolar echinococcosis in Austria from 1854 to 1990.

    PubMed

    Auer, H; Aspöck, H

    1991-01-01

    Since the second half of the last century it has been known that Austria--like southern Germany, eastern France and Switzerland--is a part of the Central European area of distribution of Echinococcus multilocularis (Em), the causative organism of alveolar echinococcosis (AE). Up until October 1990, 128 human AE cases were documented in Austria; personal, anamnestic and clinical data on the majority of these patients are available. Based on these data, epidemiological parameters (incidence, prevalence, geographic distribution, sex and age distribution, occupation) were evaluated so as to obtain information on the past and recent history of alveolar echinococcosis in Austria. The (retrospective) study led to the following results and conclusions: (a) the (documented) incidence (presently two cases/year) of AE in Austria is rather low; (b) the main endemic Em areas are situated in the western (Tyrol, Vorarlberg) and southern (Carinthia) provinces; (c) a new focus could be detected in Lower Austria (outside the Alps); (d) the sex ratio (M:F) of AE patients was 1.3:1; (e) the average age of men and women at the time of diagnosis was 44 and 47 years, respectively; (f) 98% of Austrian AE patients exhibited Em lesions in the liver; and (g) greater than 50% of AE patients were (or had been) farmers. PMID:1891451

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

    SciTech Connect

    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.

  14. Relative inequalities in geographic distribution of health care resources in Kermanshah province, Islamic Republic of Iran.

    PubMed

    Rezaei, S; Karyani, A K; Fallah, R; Matin, B K

    2016-01-01

    This study aimed to evaluate inequalities in the geographical distribution of human and physical resources in the health sector of Kermanshah province, Islamic Republic of Iran. In a retrospective, cross-sectional study, data from the Statistical Centre of Iran were used to calculate inequality measures (Gini coefficient and index of dissimilarity) over the years 2005-11. The highest Gini coefficient for human resources was observed for pharmacists in 2005 (0.75) and the lowest for paramedics in 2010 and 2011 (0.10). The highest indices of dissimilarity were also for pharmacists in 2005 (29%) and paramedics in 2011 (3%). For physical resources, the highest and lowest Gini coefficients were for rehabilitation centres in 2010 (0.59) and health houses in 2011 (0.12) respectively. Generally, inequalities in the distribution of health care resources were lower at the end of the study period, although there was potential for more equitable distribution of pharmacists, specialists, health houses and beds. PMID:27117646

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

    PubMed

    Marzinelli, Ezequiel M; Williams, Stefan B; Babcock, Russell C; Barrett, Neville S; Johnson, Craig R; Jordan, Alan; Kendrick, Gary A; Pizarro, Oscar R; Smale, Dan A; Steinberg, Peter D

    2015-01-01

    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. PMID:25693066

  16. Large-Scale Geographic Variation in Distribution and Abundance of Australian Deep-Water Kelp Forests

    PubMed Central

    Marzinelli, Ezequiel M.; Williams, Stefan B.; Babcock, Russell C.; Barrett, Neville S.; Johnson, Craig R.; Jordan, Alan; Kendrick, Gary A.; Pizarro, Oscar R.; Smale, Dan A.; Steinberg, Peter D.

    2015-01-01

    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. PMID:25693066

  17. Increasing Incidence and Geographic Distribution of Neonatal Abstinence Syndrome: United States 2009-2012

    PubMed Central

    Patrick, Stephen W.; Davis, Matthew M.; Lehman, Christoph U.; Cooper, William O.

    2015-01-01

    Objective Neonatal abstinence syndrome (NAS), a postnatal opioid withdrawal syndrome, increased 3-fold from 2000 to 2009. Since 2009, opioid pain reliever prescriptions and complications increased markedly throughout the US. Understanding recent changes in NAS and its geographic variability would inform state and local governments in targeting public health responses. Study Design We utilized diagnostic and demographic data for hospital discharges from 2009 to 2012 from the Kids’ Inpatient Database and the Nationwide Inpatient Sample. NAS-associated diagnoses were identified utilizing ICD-9-CM codes. All analyses were conducted with nationally weighted data. Expenditure data were adjusted to 2012 US dollars. Between-year differences were determined utilizing least squares regression. Results From 2009 to 2012, NAS incidence increased nationally from 3.4 (95%CI: 3.2-3.6) to 5.8 (95%CI 5.5-6.1) per 1,000 hospital births, reaching a total of 21,732 infants with the diagnosis. Aggregate hospital charges for NAS increased from $732M to $1.5B (p<0.001), with 81% attributed to state Medicaid programs in 2012. NAS incidence varied by geographic Census division, with the highest incidence rate (per 1000 hospital births) of 16.2 (95%CI 12.4-18.9) in the East South Central Division (KY, TN, MS, AL) and the lowest in West South Central Division 2.6 (95%CI 2.3-2.9; [OK, TX, AR, LA]). Conclusion NAS incidence and hospital charges grew substantially during our study period. This costly public health problem merits a public health approach to alleviate harm to women and children. States, particularly in areas of the country most affected by the syndrome, must continue to pursue primary prevention strategies to limit the effects of opioid pain reliever misuse. PMID:25927272

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

    PubMed Central

    2013-01-01

    Background 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. Methods 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 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. Conclusions 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. PMID:23705798

  19. Spatiotemporal change in geographical distribution of global climate types in the context of climate warming

    NASA Astrophysics Data System (ADS)

    Zhang, Xianliang; Yan, Xiaodong

    2014-08-01

    After standardizing global land climate gridded data from the Climatic Research Unit TS (time-series) 3.1 dataset for the period 1901-2009, cluster analysis is used to objectively classify world climates into 14 climate types. These climate types establish a baseline classification map and the types are named according to Köppen-Geiger climate classifications. Although the cluster analysis and Köppen classification methods are very different, the distributions of climate types obtained by the two methods are similar. Moreover, the climate types we identify also coincide well with their corresponding vegetation types. Thus, cluster analysis can be used as an effective alternative to the Köppen classification method for classifying world climate types. The spatial and temporal changes in geographical distribution of global climate types were investigated in 25-year intervals, and Cohen's kappa coefficient is used to detect agreement between the periods. Globally, although an obvious trend in increasing global temperature is found, distribution of climate types overall show no distinct changes over the periods. However, at the regional scale, spatial change in distribution of climate types is evident in South America and Africa. In South America, larger areas of the "fully humid equatorial rainforest" (Af) and "equatorial savannah with dry winter" (Aw) climate types have changed types. In Africa, changes mainly occurred in the Af, "equatorial savannah with dry summer" (As), Aw, "steppe climate" (BS), and "desert climate" (BW) climate types. Moreover, some climate types, including Af, "equatorial monsoon" (Am), BS, BW, and "tundra climate" (ET), were susceptible to temporal climate changes, especially in the period 1976-2009.

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

    PubMed Central

    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

    Background 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. Methodology 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. Principal Findings 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. Conclusions Podoconiosis is more widespread in Ethiopia than previously estimated, but occurs in distinct geographical regions that are tied to identifiable environmental

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

    PubMed Central

    2008-01-01

    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. PMID:18577226

  2. Genetic Diversity and Geographic Distribution of Genetically Distinct Rabies Viruses in the Philippines

    PubMed Central

    Saito, Mariko; Oshitani, Hitoshi; Orbina, Jun Ryan C.; Tohma, Kentaro; de Guzman, Alice S.; Kamigaki, Taro; Demetria, Catalino S.; Manalo, Daria L.; Noguchi, Akira; Inoue, Satoshi; Quiambao, Beatriz P.

    2013-01-01

    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. PMID:23593515

  3. Renibacterium salmoninarum p57 antigenic variation is restricted in geographic distribution and correlated with genomic markers.

    PubMed

    Wiens, Gregory D; Dale, Ole Bendik

    2009-02-12

    The 57 kDa protein (p57) is an important diagnostic antigen that is implicated in the pathogenesis of salmonid bacterial kidney disease. Little is known about the nature and extent of antigenic variation in p57. Previously, we reported that p57 produced by Renibacterium salmoninarum Strain 684 contains a mutation that disrupts monoclonal antibody (MAb) 4C11 binding. In the present study, we examined MAb binding to a panel of 23 additional R. salmoninarum isolates obtained from diverse geographic locations to examine the prevalence of this variant and whether additional variability exists within other p57 epitopes. Six p57-specific MAbs (4C11, 4D3, 3H1, 4H8, 4D10 and 1A1) were used to probe dot and western blots to determine the relative expression, size and cellular association of p57. Full-length p57 was produced by all isolates, and for each isolate, the protein was associated with the bacterial cell surface. The epitopes recognized by 4 MAbs, 4D3, 4H8, 3H1 and 1A1, were conserved among all strains tested. The 4C11 epitope was absent in 5 of 8 strains originating from Norway, while the 4D10 epitope was partially disrupted in one isolate from British Columbia, Canada. The 5 Norwegian antigenic-variant strains appeared to be clonally related as they shared the following characteristics: one tandem repeat in the ETRA locus, a Sequovar-4 16-23S rRNA intervening DNA sequence, a larger XhoI fragment in the msa1 5' region, and absent msa3 gene. These results indicate that limited antigenic and genomic variation exists between strains and this variation appears geographically restricted in distribution. PMID:19326793

  4. Prevalence, geographical distribution and clinical manifestations of onchocerciasis on the Island of Bioko (Equatorial Guinea).

    PubMed

    Mas, J; Yumbe, A; Solé, N; Capote, R; Cremades, T

    1995-03-01

    A survey for the prevalence, geographical distribution and clinical manifestations of onchocerciasis was conducted on the Island of Bioko (formerly Fernando Póo), Equatorial Guinea, between 1987-89. The whole population (1799 inhabitants) of thirteen villages distributed around the island was surveyed. Identification data, physical examination and Snellen "E" test for visual acuity were performed. Skin snips were taken from both iliac crests and right scapula and calf. Differential diagnosis between Onchocerca volvulus and Mansonella streptocerca was carried out in both fresh and Giemsa stained preparations. The overall prevalence (+ skin snips) and mean microfilarial density were 75.2% (range 51.9% to 87.1%) and 32.2 mf/snip respectively. Skin snips showed a higher microfilarial density from iliac crests. The following clinical manifestations were found: 560 (31.2%) with nodules; 518 (28.8%) with dermatitis, pigmentation changes and cutaneous atrophy; 753 (41.9%) with lymphoadenopathy and lymphoedema. Blindness due to different causes was registered in 13 cases (0.8%). The results showed that onchocerciasis is hyperendemic and widespread over the island. It is estimated that almost the whole population (62,000) is at risk of infection. PMID:7631122

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

    PubMed Central

    Gurgel-Gonçalves, Rodrigo; Galvão, Cléber; Costa, Jane; Peterson, A. Townsend

    2012-01-01

    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. PMID:22523500

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  8. Prevalence and geographical distribution of Escherichia coli O157 in India: a 10-year survey.

    PubMed

    Sehgal, Rakesh; Kumar, Yashwant; Kumar, Sunil

    2008-04-01

    Escherichia coli colonizes the human gastrointestinal tract and produces a variety of diseases. Escherichia coli O157 is one of the most important pathogenic strains reported from food-borne illnesses leading to enterohemorrhagic colitis. The National Salmonella and Escherichia Centre is a national reference centre for Salmonella and Escherichia for India; it receives samples from research laboratories, hospitals and institutions for serological identification. The present study is an epidemiological survey of E. coli O157 in different regions of India. The data are based on samples received from humans, food items, animals and the environment. A total of 17 093 isolates cultured from samples were received during the 10-year period of which 5678 were from human sources. Thirty (0.5%) human samples were positive for E. coli O157. A significantly high percentage of E. coli O157 were isolated from meat (0.9%, 13/1376), milk and milk products (1.8%, 10/553), seafood (8.4%, 16/190) and water (1.6%, 8/486). The isolates were found to be distributed among domestic and wild animals, and the maximum number of isolates of E. coli O157 was detected in samples received from coastal belt areas. Escherichia coli O157 is widely distributed among humans and animals, food and environment in different geographical regions of India. PMID:18321544

  9. Contrasting patterns of clonality and fine-scale genetic structure in two rare sedges with differing geographic distributions

    PubMed Central

    Binks, R M; Millar, M A; Byrne, M

    2015-01-01

    For plants with mixed reproductive capabilities, asexual reproduction is more frequent in rare species and is considered a strategy for persistence when sexual recruitment is limited. We investigate whether asexual reproduction contributes to the persistence of two co-occurring, rare sedges that both experience irregular seed set and if their differing geographic distributions have a role in the relative contribution of clonality. Genotypic richness was high (R=0.889±0.02) across the clustered populations of Lepidosperma sp. Mt Caudan and, where detected, clonal patches were small, both in ramet numbers (⩽3 ramets/genet) and physical size (1.3±0.1 m). In contrast, genotypic richness was lower in the isolated L. sp. Parker Range populations, albeit more variable (R=0.437±0.13), with genets as large as 17 ramets and up to 5.8 m in size. Aggregated clonal growth generated significant fine-scale genetic structure in both species but to a greater spatial extent and with additional genet-level structure in L. sp. Parker Range that is likely due to restricted seed dispersal. Despite both species being rare, asexual reproduction clearly has a more important role in the persistence of L. sp. Parker Range than L. sp. Mt Caudan. This is consistent with our prediction that limitations to sexual reproduction, via geographic isolation to effective gene exchange, can lead to greater contributions of asexual reproduction. These results demonstrate the role of population isolation in affecting the balance of alternate reproductive modes and the contextual nature of asexual reproduction in rare species. PMID:25873148

  10. Influence of host and geographic locale on the distribution of Colletotrichum cereale lineages.

    PubMed

    Beirn, Lisa A; Clarke, Bruce B; Crouch, Jo Anne

    2014-01-01

    Colletotrichum cereale is an ascomycete inhabitant of cool-season Pooideae grasses. The fungus has increased in frequency over the past decade as a destructive pathogen of Poa annua and Agrostis stolonifera turfgrass. Colletotrichum cereale exists as two lineages, designated clades A and B, but little is known about the distribution of these clades in natural environments, or what role these subdivisions may play in the trajectory of disease outbreaks. In this study, our objective was to determine the frequency of C. cereale clades A and B. To rapidly discriminate between the two C. cereale clades, a real-time PCR assay was developed based on the Apn2 gene. A collection of 700 C. cereale pathogens and endophytes from twenty Pooideae grass genera were genotyped. 87% of the collection was identifed as part of clade A, 11.7% as part of clade B, and 1.3% was a mixture. Colletotrichum cereale from turfgrass hosts in North America were most commonly members of clade A (78%). The overabundance of clade A in turfgrass isolates was directly attributable to the dominance of this lineage from southern sampling sites, irrespective of host. In contrast, 111 C. cereale turfgrass isolates collected from northern sampling sites were evenly distributed between clades A and B. Only 28% of C. cereale from A. stolonifera at northern sampling sites were part of clade A. These data show that environmental factors such as geographic location and host identity likely played a role in the distribution of the major C. cereale clades in North American turfgrass. PMID:24842654

  11. Influence of Host and Geographic Locale on the Distribution of Colletotrichum cereale Lineages

    PubMed Central

    Beirn, Lisa A.; Clarke, Bruce B.; Crouch, Jo Anne

    2014-01-01

    Colletotrichum cereale is an ascomycete inhabitant of cool-season Pooideae grasses. The fungus has increased in frequency over the past decade as a destructive pathogen of Poa annua and Agrostis stolonifera turfgrass. Colletotrichum cereale exists as two lineages, designated clades A and B, but little is known about the distribution of these clades in natural environments, or what role these subdivisions may play in the trajectory of disease outbreaks. In this study, our objective was to determine the frequency of C. cereale clades A and B. To rapidly discriminate between the two C. cereale clades, a real-time PCR assay was developed based on the Apn2 gene. A collection of 700 C. cereale pathogens and endophytes from twenty Pooideae grass genera were genotyped. 87% of the collection was identifed as part of clade A, 11.7% as part of clade B, and 1.3% was a mixture. Colletotrichum cereale from turfgrass hosts in North America were most commonly members of clade A (78%). The overabundance of clade A in turfgrass isolates was directly attributable to the dominance of this lineage from southern sampling sites, irrespective of host. In contrast, 111 C. cereale turfgrass isolates collected from northern sampling sites were evenly distributed between clades A and B. Only 28% of C. cereale from A. stolonifera at northern sampling sites were part of clade A. These data show that environmental factors such as geographic location and host identity likely played a role in the distribution of the major C. cereale clades in North American turfgrass. PMID:24842654

  12. Thyroid cancer epidemiology in England and Wales: time trends and geographical distribution.

    PubMed Central

    dos Santos Silva, I.; Swerdlow, A. J.

    1993-01-01

    Thyroid cancer incidence has been increasing in many countries, whereas mortality has been falling due to better survival. Radiation is the best-established risk factor and there has been concern that recent rises in incidence might be related to fallout radiation from atmospheric nuclear weapon tests. We examined thyroid cancer time trends and geographical distribution in England and Wales and possible interpretations of these. During 1962-84, there were significant increases in incidence (P < 0.001) in each sex at ages under 45. Cohort analysis by single year of birth showed an overall increase in incidence risks in women aged 0-44 born since 1920, with a sudden rise in risk for the birth years 1952-55 followed by a lower risk for the more recent cohorts. In men, there was an overall increase in risk at ages 0-44 in successive birth cohorts, but the pattern was irregular. In each sex, the risk in persons aged 45 and over decreased slightly in successive generations. Geographically, highest incidence risks were in countries in North and Mid Wales, in which the risk was almost twice that in the rest of the country. This pattern was present only at ages 45 and over and was most clear in rural areas. The peak of thyroid cancer risk in women born in 1952-55 is consistent with a carcinogenic effect of fallout radiation, since these women were children in the late 1950s and early 1960s when fallout radiation was greatest in England and Wales. The focus of high thyroid cancer risks in Wales was in areas with high levels of fallout radiation. However, thyroid cancer risks in Wales were not high for more recent cohorts (the ones who were exposed to fallout early in life), and a focus on high risk of benign thyroid diseases was present in Wales well before nuclear weapons existed. The distributions of these benign thyroid diseases, or of factors causing them, seem more likely than fallout to explain the high risk areas for thyroid cancer in the country. PMID:8431362

  13. Thyroid cancer epidemiology in England and Wales: time trends and geographical distribution.

    PubMed

    dos Santos Silva, I; Swerdlow, A J

    1993-02-01

    Thyroid cancer incidence has been increasing in many countries, whereas mortality has been falling due to better survival. Radiation is the best-established risk factor and there has been concern that recent rises in incidence might be related to fallout radiation from atmospheric nuclear weapon tests. We examined thyroid cancer time trends and geographical distribution in England and Wales and possible interpretations of these. During 1962-84, there were significant increases in incidence (P < 0.001) in each sex at ages under 45. Cohort analysis by single year of birth showed an overall increase in incidence risks in women aged 0-44 born since 1920, with a sudden rise in risk for the birth years 1952-55 followed by a lower risk for the more recent cohorts. In men, there was an overall increase in risk at ages 0-44 in successive birth cohorts, but the pattern was irregular. In each sex, the risk in persons aged 45 and over decreased slightly in successive generations. Geographically, highest incidence risks were in countries in North and Mid Wales, in which the risk was almost twice that in the rest of the country. This pattern was present only at ages 45 and over and was most clear in rural areas. The peak of thyroid cancer risk in women born in 1952-55 is consistent with a carcinogenic effect of fallout radiation, since these women were children in the late 1950s and early 1960s when fallout radiation was greatest in England and Wales. The focus of high thyroid cancer risks in Wales was in areas with high levels of fallout radiation. However, thyroid cancer risks in Wales were not high for more recent cohorts (the ones who were exposed to fallout early in life), and a focus on high risk of benign thyroid diseases was present in Wales well before nuclear weapons existed. The distributions of these benign thyroid diseases, or of factors causing them, seem more likely than fallout to explain the high risk areas for thyroid cancer in the country. PMID:8431362

  14. Chronic kidney diseases of uncertain etiology (CKDue) in Sri Lanka: geographic distribution and environmental implications.

    PubMed

    Chandrajith, Rohana; Nanayakkara, Shanika; Itai, Kozuyoshi; Aturaliya, T N C; Dissanayake, C B; Abeysekera, Thilak; Harada, Kouji; Watanabe, Takao; Koizumi, Akio

    2011-06-01

    The increase in the number of chronic kidney disease (CKD) patients from the north central region of Sri Lanka has become a environmental health issue of national concern. Unlike in other countries where long-standing diabetes and hypertension are the leading causes of renal diseases, the majority of CKD patients from this part of Sri Lanka do not show any identifiable cause. As the disease is restricted to a remarkably specific geographical terrain, particularly in the north central dry zone of the country, multidisciplinary in-depth research studies are required to identify possible etiologies and risk factors. During this study, population screening in the prevalent region and outside the region, analysis of geoenvironmental and biochemical samples were carried out. Population screening that was carried out using a multistage sampling technique indicated that the point prevalence of CKD with uncertain etiology is about 2-3% among those above 18 years of age. Drinking water collected from high-prevalent and non-endemic regions was analyzed for their trace and ultratrace element contents, including the nephrotoxic heavy metals Cd and U using ICP-MS. The results indicate that the affected regions contain moderate to high levels of fluoride. The Cd contents in drinking water, rice from affected regions and urine from symptomatic and non-symptomatic patients were much lower indicating that Cd is not a contributing factor for CKD with uncertain etiology in Sri Lanka. Although no single geochemical parameter could be clearly and directly related to the CKD etiology on the basis of the elements determined during this study, it is very likely that the unique hydrogeochemistry of the drinking water is closely associated with the incidence of the disease. PMID:20853020

  15. Geographic distribution of isolated indigenous societies in Amazonia and the efficacy of indigenous territories.

    PubMed

    Kesler, Dylan C; Walker, Robert S

    2015-01-01

    The headwaters of the Amazon Basin harbor most of the world's last indigenous peoples who have limited contact with encroaching colonists. Knowledge of the geographic distribution of these isolated groups is essential to assist with the development of immediate protections for vulnerable indigenous settlements. We used remote sensing to document the locations of 28 isolated villages within the four Brazilian states of Acre, Amazonas, Roraima, and Rondônia. The sites were confirmed during previous over-flights and by image evidence of thatched-roof houses; they are estimated to host over 1,700 individuals. Locational data were used to train maximum entropy models that identified landscape and anthropogenic features associated with the occurrence of isolated indigenous villages, including elevation, proximity to streams of five different orders, proximity to roads and settlements, proximity to recent deforestation, and vegetation cover type. Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails. We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples. Results indicate that existing indigenous territories encompass all of the villages we identified, and 50% of the areas with high predicted probabilities of isolated village occurrence. Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples. PMID:25970612

  16. Geographic Distribution of Isolated Indigenous Societies in Amazonia and the Efficacy of Indigenous Territories

    PubMed Central

    2015-01-01

    The headwaters of the Amazon Basin harbor most of the world’s last indigenous peoples who have limited contact with encroaching colonists. Knowledge of the geographic distribution of these isolated groups is essential to assist with the development of immediate protections for vulnerable indigenous settlements. We used remote sensing to document the locations of 28 isolated villages within the four Brazilian states of Acre, Amazonas, Roraima, and Rondônia. The sites were confirmed during previous over-flights and by image evidence of thatched-roof houses; they are estimated to host over 1,700 individuals. Locational data were used to train maximum entropy models that identified landscape and anthropogenic features associated with the occurrence of isolated indigenous villages, including elevation, proximity to streams of five different orders, proximity to roads and settlements, proximity to recent deforestation, and vegetation cover type. Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails. We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples. Results indicate that existing indigenous territories encompass all of the villages we identified, and 50% of the areas with high predicted probabilities of isolated village occurrence. Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples. PMID:25970612

  17. Monitoring potential geographical distribution of four wild bird species in China

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

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

    1984-08-01

    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.

  19. Potential geographical distribution of the red palm mite in South America.

    PubMed

    Amaro, George; de Morais, Elisangela Gomes Fidelis

    2013-07-01

    Among pests that have recently been introduced into the Americas, the red palm mite, Raoiella indica Hirst (Prostigmata: Tenuipalpidae), is the most invasive. This mite has spread rapidly to several Caribbean countries, United States of America, Mexico, Venezuela, Colombia and Brazil. The potential dispersion of R. indica to other regions of South America could seriously impact the cultivation of coconuts, bananas, exotic and native palms and tropical flowers such as the Heliconiaceae. To facilitate the development of efficacious R. indica management techniques such as the adoption of phytosanitary measures to prevent or delay the dispersion of this pest, the objective of this paper was to estimate the potential geographical distribution of R. indica in South America using a maximum entropy model. The R. indica occurrence data used in this model were obtained from extant literature, online databases and field sampling data. The model predicted potential suitable areas for R. indica in northern Colombia, central and northern Venezuela, Guyana, Suriname, east French Guiana and many parts of Brazil, including Roraima, the eastern Amazonas, northern Pará, Amapá and the coastal zones, from Pará to north of Rio de Janeiro. These results indicate the potential for significant R. indica related economic and social impacts in all of these countries, particularly in Brazil, because the suitable habitat regions overlap with agricultural areas for R. indica host plants such as coconuts and bananas. PMID:23297112

  20. Frequencies and geographic distributions of genetic mutations in transthyretin- and non-transthyretin-related familial amyloidosis.

    PubMed

    Zhen, D B; Swiecicki, P L; Zeldenrust, S R; Dispenzieri, A; Mauermann, M L; Gertz, M A

    2015-10-01

    Inherited forms of amyloidosis are rare; of these, transthyretin-related (ATTR) is the most common, but non-ATTR has been described as well. We studied a large case series of ATTR and a small series of non-ATTR to better determine the mutation frequencies and geographic distributions of these inherited forms of amyloidosis in the United States. We performed a retrospective cross-sectional study of 284 ATTR and non-ATTR patients seen at Mayo Clinic in Rochester, Minnesota, from 1 January 1970 through 29 January 2013. Mutations were identified by DNA sequencing, restriction fragment length polymorphism, or mass spectroscopy. The genetic testing method was unknown for several patients, but a small proportion were identified by family history or by classical clinical presentation associated with a specific mutation. The most common ATTR mutations were Thr60Ala (24%), Val30Met (15%), Val122Ile (10%), and Ser77Tyr (5%). Non-ATTR mutations included gelsolin (n = 3), apolipoprotein A-I (n = 6), apolipoprotein A-II (n = 1), fibrinogen A-α (n = 9), and lysozyme (n = 1). Although rare, ATTR and, to a lesser extent, non-ATTR are prevalent in the United States and should be considered for patients presenting in the appropriate clinical context. PMID:25211232

  1. Zonal and geographical distributions of cirrus clouds determined from SAGE data

    NASA Technical Reports Server (NTRS)

    Woodbury, G. E.; Mccormick, M. P.

    1986-01-01

    Stratospheric Aerosol and Gas Experiment (SAGE) data obtained from February 1979-November 1981 are analyzed in order to evaluate the spatial extent and frequency occurrence of cirrus clouds. The capabilities of the SAGE measurement system which has a field of view of 100 sq km are discussed. The frequency of occurrence of the cirrus clouds and the frequency penetration of the clouds to fixed altitudes of 5, 7, and 9 km, and to altitudes of 1, 3 and 5 km below the troposphere are examined. It is observed that optically thick cirrus clouds form most frequently in the midlatitudes over the equator, with distinct minima near latitude bands of 20-30 deg north and south; height penetrations to 7 km occur 60 percent of the time in upper latitudes and drop to 30 percent over the tropics. The SAGE data are compared with selective chopper radiometer data and good correlation in shape and seasonal movement is displayed. The seasonal geographical distributions of cirrus clouds in regions of rising moist air associated with low-level convergence zones are described.

  2. Geographic Distribution and Genetic Characterization of Lassa Virus in Sub-Saharan Mali

    PubMed Central

    Safronetz, David; Sogoba, Nafomon; Lopez, Job E.; Maiga, Ousmane; Dahlstrom, Eric; Zivcec, Marko; Feldmann, Friederike; Haddock, Elaine; Fischer, Robert J.; Anderson, Jennifer M.; Munster, Vincent J.; Branco, Luis; Garry, Robert; Porcella, Stephen F.; Schwan, Tom G.; Feldmann, Heinz

    2013-01-01

    Background Lassa fever is an acute viral illness characterized by multi-organ failure and hemorrhagic manifestations. Lassa fever is most frequently diagnosed in Nigeria, Sierra Leone, Liberia, and Guinea, although sporadic cases have been recorded in other West African countries, including Mali. The etiological agent of Lassa fever is Lassa virus (LASV), an Arenavirus which is maintained in nature and frequently transmitted to humans by Mastomys natalensis. The purpose of this study was to better define the geographic distribution of LASV-infected rodents in sub-Saharan Mali. Methodologies/Principal Findings Small mammals were live-trapped at various locations across Mali for the purpose of identifying potential zoonotic pathogens. Serological and molecular assays were employed and determined LASV infected rodents were exclusively found in the southern Mali near the border of Côte d'Ivoire. Overall, 19.4% of Mastomys natalensis sampled in this region had evidence of LASV infection, with prevalence rates for individual villages ranging from 0 to 52%. Full-length genomic sequences were determined using high throughput sequencing methodologies for LASV isolates generated from tissue samples of rodents collected in four villages and confirmed the phylogenetic clustering of Malian LASV with strain AV. Conclusions/Significance The risk of human infections with LASV is greatest in villages in southern Mali. Lassa fever should be considered in the differential diagnosis for febrile individuals and appropriate diagnostic techniques need to be established to determine the incidence of infection and disease in these regions. PMID:24340119

  3. Interactions among climate and soil properties influence current and future geographic distribution of an invasive grass in the Chihuahuan Desert

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Question/Methods: Lehmann lovegrass (Eragrostis lehmanniana) is an invasive exotic perennial grass throughout the Sonoran Desert. However, in the neighboring Chihuahuan Desert, this species is generally present in low abundance, although data on its geographic distribution are scarce. Our...

  4. Geographical Distribution of Federal Science Funds to Colleges and Universities. Report of the Comptroller General of the United States.

    ERIC Educational Resources Information Center

    Comptroller General of the U.S., Washington, DC.

    This report provides data on the geographical distribution patterns of federal research and development and other funds to colleges and universities, information on federal programs established in the 1960's to strengthen academic science, and factors accounting for progress by universities in competing for federal funds. Summarizing statements…

  5. Frequency and Geographical Distribution of Plant-Parasitic Nematodes on Cotton in Georgia

    PubMed Central

    Baird, R. E.; Davis, R. F.; Alt, P. J.; Mullinix, B. G.; Padgett, G. B.

    1996-01-01

    A survey was conducted to examine the geographical distribution of plant-parasitic nematodes in Georgia cotton fields. A total of 778 fields in 11 Georgia counties were sampled from 1 September through 15 December 1995. Four nematode genera parasitic on cotton were found in this survey: Meloidogyne spp., Rotylenchulus sp., Hoplolaimus sp., and Belonolaimus sp. Meloidogyne spp. was present in 9% to 56% of the fields in individual counties. Rotylenchulus sp. was found in 10 counties, Hoplolaimus sp. was found in 6 counties, and Belonolaimus sp. was found in 2 counties. From all of the samples collected for this survey, Meloidogyne spp. were found in 31% of the samples, Rotylenchulus sp. was found in 14%, Hoplolaimus sp. was found in 7%, and Belonolaimus sp. was found in 0.3%. Burke County had the greatest number of fields infested by at least one of these genera (67%) and the greatest number of fields above Georgia's action thresholds (38%). Laurens County had the fewest fields where these genera were present (13%), and only 3% of fields had nematode populations above threshold levels. Data from samples collected from cotton fields and submitted by county agents from 1993 through 1994 were compiled to provide historical information about nematode distribution and population density. The results from this survey show that the major nematodes damaging to cotton are not present in all counties in Georgia. Counties in which cotton has historically been a major crop are likely to have higher levels of Meloidogyne spp., Hoplolaimus sp., and Rotylenchulus sp. in current cotton crops. Counties in which soybean has historically been a major crop are likely to have higher levels of Hoplolaimus sp. and Rotylenchulus sp. in current cotton crops. PMID:19277192

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

    PubMed

    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

  7. RE-EVALUATION OF THE GEOGRAPHIC DISTRIBUTION AND PHYLOGEOGRAPHY OF THE SIGMODON HISPIDUS COMPLEX BASED ON MITOCHONDRIAL DNA SEQUENCES

    PubMed Central

    Bradley, Robert D.; Henson, Dallas D.; Durish, Nevin D.

    2010-01-01

    Geographic distribution among members of the Sigmodon hispidus complex (Sigmodon hirsutus, S. hispidus, and S. toltecus) were examined using DNA sequences from the mitochondrial cytochrome-b gene. Geographic distribution of each taxon was defined based on DNA sequences obtained from 69 samples (19 newly obtained and 50 from previous studies) collected from North, Central, and South America. These data indicated that S. hispidus is restricted to the southern one-half of the United States and northeastern Mexico (Nuevo León and Tamaulipas), S. toltecus occupies the eastern one-third of Mexico (central Tamaulipas) to northern Honduras, and S. hirsutus is distributed from central Chiapas and southeastern Oaxaca to northern South America (Venezuela). The newly collected data extend distributions of S. hispidus from the southern United States southward into northeastern Mexico and that of S. toltecus from Chiapas, Mexico, southward to Honduras. Genetic divergence and patterns of phylogeography were examined within each taxon. PMID:20613884

  8. Geographical distribution and anisotropy of the inverse kinetic energy cascade, and its role in the eddy equilibrium processes

    NASA Astrophysics Data System (ADS)

    Wang, Shihong; Liu, Zhiliang; Pang, Chongguang

    2015-07-01

    The geographic character of the inverse cascade is analyzed based on the spectral kinetic energy flux calculated in the global ocean, using sea surface height (SSH) data from satellites, reanalysis data, and model outputs. It is shown that the strongest inverse cascade occurs mostly in high-energy eastward-flowing currents, such as the Antarctic Circumpolar Current (ACC), the Kuroshio Extension, and the Gulf Stream, which matches the global distribution pattern of the eddy kinetic energy (EKE). Hence, the eddy scales predicted by the local linear baroclinic instability Lbci and from the altimeter observation Leddy are mapped out and compared with the energy injection scale Linj and the arrest-start scale Larrest-start of the inverse cascade, respectively. Generally, Lbci agrees well with Linj in the midlatitude and high-latitude oceans, especially in the Northern Hemisphere. Leddy falls within the arrest ranges of the inverse cascade and is quite close to Larrest-start. Finally, the depth dependence and the anisotropy of the inverse kinetic energy cascade are also diagnosed in the global ocean. We have found that the strength of the inverse cascades decreases with increasing depth, but the global pattern of the strength is nearly invariable. Meanwhile, the variations in depth hardly affect the Linj and Larrest-start. After considering the anisotropy in the spectral flux calculation, a possible inertial range for the zonal spectral kinetic energy flux is expected, where the cascade magnitude will keep a nearly constant negative value associated with the oceanic zonal jets.

  9. Investigation of the transport processes controlling the geographic distribution of carbon monoxide at the tropical tropopause

    NASA Astrophysics Data System (ADS)

    Jensen, E. J.; Pfister, L.; Ueyama, R.; Bergman, J. W.; Kinnison, D.

    2015-03-01

    Convectively influenced trajectory calculations are used to investigate the impact of different Tropical Tropopause Layer (TTL) transport pathways for establishing the distribution of carbon monoxide (CO) at 100 hPa as observed by the Microwave Limb Sounder (MLS) on board the Aura satellite. Carbon monoxide is a useful tracer for investigating TTL transport and convective influence because the CO lifetime (≃1-2 months) is comparable to the time required for slow ascent through the TTL. MERRA horizontal winds are used for the diabatic trajectories, and off-line calculations of TTL radiative heating are used to determine the vertical motion field. The locations and times of convective influence events along the trajectories are determined from 3-hourly, geostationary satellite measurements of convective clouds. The trajectory model reproduces most of the prominent features in the 100 hPa CO geographic distribution indicated by the MLS observations for the winter and summer 2007 periods simulated. CO concentrations and tendencies simulated with the Whole Atmosphere Climate Chemistry Model (WACCM) are used to specify boundary-layer concentrations for convective influence and CO loss rates resulting from reaction with OH. The broad maximum in CO concentration over the Pacific during Boreal winter is primarily a result of the strong radiative heating (corresponding to upward vertical motion) associated with the abundant TTL cirrus in this region. Convection over the Pacific brings clean maritime air to the tropopause region and actually decreases the 100 hPa CO. The relative abundance of CO over the continental convective regions during wintertime is sensitive to small variations in convective cloud-top height. Both the simulated and the observed summertime 100 hPa CO distributions are dominated by the maximum co-located with the upper level anticyclone forced by the Asian monsoon convection. Sensitivity tests indicate that the summertime Asian monsoon anticyclone 100

  10. Analysis of Impact of Geographical Environment and Socio-economic Factors on the Spatial Distribution of Kaohsiung Dengue Fever Epidemic

    NASA Astrophysics Data System (ADS)

    Hsu, Wei-Yin; Wen, Tzai-Hung; Yu, Hwa-Lung

    2013-04-01

    Taiwan is located in subtropical and tropical regions with high temperature and high humidity in the summer. This kind of climatic condition is the hotbed for the propagation and spread of the dengue vector mosquito. Kaohsiung City has been the worst dengue fever epidemic city in Taiwan. During the study period, from January 1998 to December 2011, Taiwan CDC recorded 7071 locally dengue epidemic cases in Kaohsiung City, and the number of imported case is 118. Our research uses Quantile Regression, a spatial infection disease distribution, to analyze the correlation between dengue epidemic and geographic environmental factors and human society factors in Kaohsiung. According to our experiment statistics, agriculture and natural forest have a positive relation to dengue fever(5.5~34.39 and 3.91~15.52). The epidemic will rise when the ratio for agriculture and natural forest increases. Residential ratio has a negative relation for quantile 0.1 to 0.4(-0.005~-0.78), and a positive relation for quantile 0.5 to0.9(0.01~18.0) . The mean income is also a significant factor in social economy field, and it has a negative relation to dengue fever(-0.01~-0.04). Conclusion from our research is that the main factor affecting the degree of dengue fever in predilection area is the residential proportion and the ratio of agriculture and natural forest plays an important role affecting the degree of dengue fever in non predilection area. Moreover, the serious epidemic area located by regression model is the same as the actual condition in Kaohsiung. This model can be used to predict the serious epidemic area of dengue fever and provide some references for the Health Agencies

  11. Geographical distribution of shear wave anisotropy within marine sediments in the northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Tonegawa, Takashi; Fukao, Yoshio; Fujie, Gou; Takemura, Shunsuke; Takahashi, Tsutomu; Kodaira, Shuichi

    2015-12-01

    In the northwestern Pacific, the elastic properties of marine sediments, including P-wave velocities ( Vp) and S wave velocities ( Vs), have recently been constrained by active seismic surveys. However, information on S anisotropy associated with the alignments of fractures and fabric remains elusive. To obtain such information, we used ambient noise records observed by ocean-bottom seismometers at 254 sites in the northwestern Pacific to calculate the auto-correlation functions for the S reflection retrieval from the top of the basement. For these S reflections, we measured differential travel times and polarized directions to reveal the potential geographical systematic distribution of S anisotropy. As a result, the observed differential times between fast and slow axes were at most 0.05 s. The fast polarization axes tend to align in the trench-parallel direction in the outer rise region. In particular, their directions changed systematically in accordance with the direction of the trench axis, which changes sharply across the junction of the Kuril and Japan trenches. We consider that a contributing factor for the obtained S anisotropy within marine sediments in the outer rise region is primarily aligned fractures due to the tensional stresses associated with the bending of the Pacific Plate. Moreover, numerical simulations conducted by using the three-dimensional (3D) finite difference method for isotropic and anisotropic media indicates that the successful extraction of S anisotropic information from the S reflection observed in this study is obtained from near-vertically propagating S waves due to extremely low Vs within marine sediments. In addition, we conducted an additional numerical simulation with a realistic velocity model to confirm whether S reflections below the basement can be extracted or not. The resultant auto-correlation function shows only S reflections from the top of the basement. It appears that such near-vertically propagating S waves

  12. Time Trends and Geographical Distribution of Childhood Leukaemia in Basrah, Iraq, from 2004 to 2009

    PubMed Central

    Alrudainy, Laith A; Hassan, Jenan G; Salih, Hussam M; Abbas, Mohammed K; Majeed, Athar AS

    2011-01-01

    Objectives: This study aimed to assess the incidence and trend of childhood leukaemia in Basrah. Methods: This was a hospital-based cancer registry study carried out at the Pediatric Oncology Ward, Maternity & Children’s Hospital and other institutes in Basrah, Iraq. All children with leukaemia, aged 0 to 14 years diagnosed and registered in Basrah from January 2004 to December 2009 were included in the study. Their records were retrieved and studied. The pattern of childhood leukaemia by year of diagnosis, age at diagnosis, morphological subtypes, and geographical distribution was analysed. Rates of childhood leukaemia over time were calculated for six years using standard linear regression. Results: The total number of cases of childhood leukaemia was 181. The number of cases ranged from 21 in year 1, to 31 in the final year reaching a peak of 39 in 2006. Leukaemia rates did not change over the study period (test for trend was not significant, P = 0.81). The trend line shows a shift towards younger children (less than 5 years). The commonest types of leukaemia were acute lymphoblastic leukaemia (ALL), then acute myeloid leukaemia (AML) and finally chronic myeloid leukaemia (CML). Conclusion: Annual rates of childhood leukaemia in Basrah were similar to those in other countries with a trend towards younger children. This raises the question about the effect of environmental catastrophes in the alteration of some specific rates of childhood leukaemia, rather than the overall incidence rate. There is a need for further epidemiological studies to understand the aetiology of childhood leukaemia in Basrah. PMID:21969893

  13. Application of Geographic Information Systems (GIS) in Analysing Rainfall Distribution Patterns in Batu Pahat District

    NASA Astrophysics Data System (ADS)

    Kadir, A. A.; Kaamin, M.; Azizan, N. S.; Sahat, S.; Bukari, S. M.; Mokhtar, M.; Ngadiman, N.; Hamid, N. B.

    2016-07-01

    Rainfall forecasting reports are crucial to provide information and warnings to the population in a particular location. The Malaysian Meteorology Department (MMD) is a department that plays an important role in monitoring the situation and issued the statement of changes in weather and provides services such as weather advisories and gives warnings when the situation requires. Uncertain weather situations normally have created panic situation, especially in big cities because of flash floods due to poor drainage management. Usually, local authorities provided rainfall data in tables, and it is difficult to analyse to acquire the rainfall trend. Therefore, Geographic Information System (GIS) applications are commonly used to generate rainfall patterns in visual formation with a combination of characteristics of rainfall data and then can be used by stakeholders to facilitate the process of analysis and forecasting rainfall. The objective of this study is to determine the pattern of rainfall distribution using GIS applications in Batu Pahat district to assist interested parties to understand and easy to analyse the rainfall data in visual form or mapping form. Rainfall data for a period of 10 years (2004-2013) and monthly data (Dec 2006 - Feb 2007) are provided by the Department of Irrigation and Drainage (DID) for 12 stations in the district of Batu Pahat, and rainfall maps in each year was obtained using the interpolation Inverse Distance Weighted (IDW) method was used in this research. The rainfall map was then analyzed to identify the highest rainfall that was received during the period of study. For the conclusion, this study has proved that rainfall analysis using GIS application is efficient to be used in gaining information of rainfall patterns as the results show that the highest rainfall occurred in 2006 and 2007, and it were the years of major floods occurrence in Batu Pahat district.

  14. Processes affecting the oceanic distributions of dissolved calcium and alkalinity

    SciTech Connect

    Shiller, A.M.; Gieskes, J.M.

    1980-05-20

    Recent studies of the CO/sub 2/ system have suggested that chemical processes in addition to the dissolution and precipitation of calcium carbonate affect the oceanic calcium and alkalinity distributions. Calcium and alkalinity data from the North Pacific have been examined both by using the simple physical-chemical model of previous workers and by a study involving the broader oceanographic context of these data. The simple model is shown to be an inadequate basis for these studies. Although a proton flux associated with organic decomposition may affect the alkalinity, previously reported deviations of calcium-alkalinity correlations from expected trends appear to be related to boundary processes that have been neglected rather than to this proton flux. The distribution of calcium in the surface waters of the Pacific Ocean is examined.

  15. Spatially distributed storm runoff modeling using remote sensing and geographic information systems

    NASA Astrophysics Data System (ADS)

    Melesse, Assefa Mekonnen

    Advances in scientific knowledge and new techniques of remote sensing permit a better understanding of the physical land features governing hydrologic processes, and make possible efficient, large-scale hydrologic modeling. The need for land-cover and hydrologic response change detection at a larger scale and at times of the year when hydrologic studies are critical makes satellite imagery the most cost effective, efficient and reliable source of data. The use of a Geographic Information System (GIS) to store, manipulate and visualize these data, and ultimately to estimate runoff from watersheds, has gained increasing attention in recent years. In this work, remotely-sensed data and GIS tools were used to estimate the changes in land-cover, and to estimate runoff response, for three watersheds (Etonia, Econlockhatchee, and S-65A sub-basins) in Florida. Land-use information from Digital Orthophoto Quarter Quadrangles (DOQQ), Landsat Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+) were analyzed for the years 1973, 1984, 1990, 1995, and 2000. Spatial distribution of land-cover was assessed over time. The corresponding infiltration excess runoff response of the study areas due to these changes was estimated using the United States Department of Agriculture, Natural Resources Conservation Service Curve Number (USDA-NRCS-CN) method. A Digital Elevation Model (DEM)-GIS technique was developed to predict stream response to runoff events based on the travel time from each grid cell to the watershed outlet. The method was tested on a representative watershed (Simms Creek) in the Etonia sub-basin. Simulated and observed runoff volume and hydrographs were compared for 17 storm events. Isolated storms, with volumes of not less than 12.75 mm (0.5 inch) were selected. This is the minimum amount of rainfall volume recommended for the NRCS-CN method. Results show that the model predicts the runoff response of the study area with an average efficiency of 57

  16. A geostatistical analysis of the geographic distribution of lymphatic filariasis prevalence in southern India.

    PubMed

    Srividya, A; Michael, E; Palaniyandi, M; Pani, S P; Das, P K

    2002-11-01

    -scale factors may characterize the observed distribution of filariasis in the study region. Our preliminary analysis of a mountain range associated large-scale trend in the antigenemia data suggested that a nonlinear relationship of infection prevalence with elevation might be a factor behind such observed global spatial patterns. We conclude that geostatistic methods can provide a powerful framework for carrying out the empirical investigation and analysis of parasite spatial population structure. This study shows that their successful application, however, will crucially depend on our gaining a more thorough understanding of the appropriate geographic scales at which spatial studies should be carried out. PMID:12479548

  17. Global phylogeography of pelagic Polynucleobacter bacteria: Restricted geographic distribution of subgroups, isolation by distance and influence of climate†

    PubMed Central

    Hahn, Martin W; Koll, Ulrike; Jezberová, Jitka; Camacho, Antonio

    2015-01-01

    The free-living planktonic freshwater bacterium Polynucleobacter necessarius subspecies asymbioticus (> 99% 16S rRNA similarity) represents a taxon with a cosmopolitan distribution and apparently ubiquitous occurrence in lentic freshwater habitats. We tested for intra-taxon biogeographic patterns by combining cultivation-independent and cultivation methods. A culture collection of 204 strains isolated from globally distributed freshwater habitats (Arctic to Antarctica) was investigated for phylogeographic patterns based on sequences of two markers, the 16S–23S internal transcribed spacers and the glutamine synthetase gene (glnA). Genetic distance between isolates showed significant geographic distance-decay patterns for both markers, suggesting that an isolation-by-distance mechanism influences the global phylogeography. Furthermore, a couple of subgroups showed restricted geographic distributions. Strains of one subgroup were exclusively obtained from tropical sites on four continents (pantropical subgroup). Cultivation-independent methods were used to confirm the restricted geographic distributions of two subgroups. The pantropical taxon could be detected in 63% of investigated tropical habitats but not in any of 121 European freshwater samples. Physiological tests indicated that almost all strains of the pantropical subgroup failed to grow at temperatures of 4°C, while strains affiliated with other subgroups showed good growth at this temperature. This suggests that thermal adaptation is involved in phylogeographic structuring of the global Polynucleobacter population. PMID:24920455

  18. Mesoniviruses are mosquito-specific viruses with extensive geographic distribution and host range

    PubMed Central

    2014-01-01

    Background The family Mesoniviridae (order Nidovirales) comprises of a group of positive-sense, single-stranded RNA ([+]ssRNA) viruses isolated from mosquitoes. Findings Thirteen novel insect-specific virus isolates were obtained from mosquitoes collected in Indonesia, Thailand and the USA. By electron microscopy, the virions appeared as spherical particles with a diameter of ~50 nm. Their 20,129 nt to 20,777 nt genomes consist of positive-sense, single-stranded RNA with a poly-A tail. Four isolates from Houston, Texas, and one isolate from Java, Indonesia, were identified as variants of the species Alphamesonivirus-1 which also includes Nam Dinh virus (NDiV) from Vietnam and Cavally virus (CavV) from Côte d’Ivoire. The eight other isolates were identified as variants of three new mesoniviruses, based on genome organization and pairwise evolutionary distances: Karang Sari virus (KSaV) from Java, Bontag Baru virus (BBaV) from Java and Kalimantan, and Kamphaeng Phet virus (KPhV) from Thailand. In comparison with NDiV, the three new mesoniviruses each contained a long insertion (180 – 588 nt) of unknown function in the 5’ region of ORF1a, which accounted for much of the difference in genome size. The insertions contained various short imperfect repeats and may have arisen by recombination or sequence duplication. Conclusions In summary, based on their genome organizations and phylogenetic relationships, thirteen new viruses were identified as members of the family Mesoniviridae, order Nidovirales. Species demarcation criteria employed previously for mesoniviruses would place five of these isolates in the same species as NDiV and CavV (Alphamesonivirus-1) and the other eight isolates would represent three new mesonivirus species (Alphamesonivirus-5, Alphamesonivirus-6 and Alphamesonivirus-7). The observed spatiotemporal distribution over widespread geographic regions and broad species host range in mosquitoes suggests that mesoniviruses may be common in

  19. A priori parameter estimates for a distributed, grid-based Xinanjiang model using geographically based information

    NASA Astrophysics Data System (ADS)

    Yao, Cheng; Li, Zhijia; Yu, Zhongbo; Zhang, Ke

    2012-10-01

    SummaryAn improved form of spatially distributed Grid-Xinanjiang model (GXM), which integrates features of a well-tested conceptual rainfall-runoff model and a physically based flow routing model, has been proposed for simulating hydrologic processes and forecasting flood events in watersheds. The digital elevation model (DEM) is utilized in the GXM to derive computational flow direction, routing sequencing, and hillslope and channel slopes. The processes in the model include canopy interception, direct channel precipitation, evapotranspiration, as well as runoff generation via a saturation excess mechanism. A two-step finite difference solution of the diffusion wave approximation of the St. Venant equations with second-order accuracy is used in the model to simulate the flow routed along the hillslope and channel on a cell basis with consideration of upstream inflow and flow partition to the channels. A physically, empirically based approach using geographically based information such as topography, soil data and land use/land cover data is employed for estimating spatially varied parameters. GXM is applied at a 1-km grid scale to a nested watershed located in Anhui province, China. The parent Tunxi watershed, with a drainage area of 2692.7 km2, contains five internal points with available observed streamflow data, allowing us to evaluate model's ability to simulate the hydrologic processes within the watershed. Calibration and verification of the proposed GXM are carried out for both daily and hourly time scales using daily rainfall-runoff data and hourly streamflow data. Model performance is assessed by comparing simulated and observed flows at the watershed outlet and interior gauging stations. Initial tests indicate that the parameter estimation approach is efficient and the developed model can satisfactorily simulate not only the streamflow at the parent watershed outlet, but also the flood hydrograph at the interior gauging points without model recalibration

  20. Internet access to the web resources of a geographically distributed system of near-and deep-space monitoring

    NASA Astrophysics Data System (ADS)

    Chernenkov, V. N.; Vitkovskij, V. V.; Kalinina, N. A.

    2007-12-01

    The state and speed characteristics of Web access to the first five nodes of the projected geographically distributed system of scientific monitoring of near and deep space are analyzed. The possibility of developing an architecture involving user query redirection to a caching server is studied. This will make it possible to relieve hardware communication links substantially and speed up HTTP connection time, especially for nodes linked via heavily congested Internet links.

  1. 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

    PubMed Central

    Felappi, Jéssica F.; Vieira, Renata C.; Fagundes, Nelson J. R.; Verrastro, Laura V.

    2015-01-01

    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. PMID:25692471

  2. Global Climate Change Effects on Venezuela's Vulnerability to Chagas Disease is Linked to the Geographic Distribution of Five Triatomine Species.

    PubMed

    Ceccarelli, Soledad; Rabinovich, Jorge E

    2015-11-01

    We analyzed the possible effects of global climate change on the potential geographic distribution in Venezuela of five species of triatomines (Eratyrus mucronatus (Stal, 1859), Panstrongylus geniculatus (Latreille, 1811), Rhodnius prolixus (Stål, 1859), Rhodnius robustus (Larrousse, 1927), and Triatoma maculata (Erichson, 1848)), vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. To obtain the future potential geographic distributions, expressed as climatic niche suitability, we modeled the presences of these species using two IPCC (Intergovernmental Panel on Climate Change) future emission scenarios of global climate change (A1B and B1), the Global Climate model CSIRO Mark 3.0, and three periods of future projections (years 2020, 2060, and 2080). After estimating with the MaxEnt software the future climatic niche suitability for each species, scenario, and period of future projections, we estimated a series of indexes of Venezuela's vulnerability at the county, state, and country level, measured as the number of people exposed due to the changes in the geographical distribution of the five triatomine species analyzed. Despite that this is not a measure of the risk of Chagas disease transmission, we conclude that possible future effects of global climate change on the Venezuelan population vulnerability show a slightly decreasing trend, even taking into account future population growth; we can expect fewer locations in Venezuela where an average Venezuelan citizen would be exposed to triatomines in the next 50-70 yr. PMID:26336258

  3. Molecular Characterization, Morphological Characteristics, Virulence, and Geographic Distribution of Rhizoctonia spp. in Washington State.

    PubMed

    Jaaffar, Ahmad Kamil Mohd; Paulitz, Timothy C; Schroeder, Kurtis L; Thomashow, Linda S; Weller, David M

    2016-05-01

    of the roots. However, all isolates of AG-2-1 caused severe damping-off of canola, resulting in 100% mortality. Isolates of Rhizoctonia AG-8, AG-2-1, AG-10, AG-I-like binucleate Rhizoctonia, and R. oryzae genotypes I, II, and III could be distinguished by colony morphology on potato dextrose agar, by PCR with specific primers, or by the type and severity of disease on wheat and canola seedlings, and results of these approaches correlated completely. Based on cultured isolates, we also identified the geographic distribution of all of these Rhizoctonia isolates in cereal-based production systems throughout Washington State. PMID:26780436

  4. Geographic Distribution of Applicants to the Saskatchewan Institute of Applied Science and Technology.

    ERIC Educational Resources Information Center

    McGartland, Gertrude; Stallard, Claire

    The Saskatchewan Institute of Applied Science and Technology (SIAST) Planning, Research and Development Division conducted three studies of the geographic origins of applicants to the Institute. The analyses of the places of origin provided SIAST with solid information to assist in planning program delivery in the province. The studies used the…

  5. Distribution of Health-Related Physical Fitness in Texas Youth: A Demographic and Geographic Analysis

    ERIC Educational Resources Information Center

    Welk, Gregory J.; Meredith, Marilu D.; Ihmels, Michelle; Seeger, Chris

    2010-01-01

    This study examined demographic and geographic variability in aggregated school-level data on the percentage of students achieving the FITNESSGRAM[R] Healthy Fitness Zones[TM] (HFZ). Three-way analyses of variance were used to examine differences in fitness achievement rates among schools that had distinct diversity and socioeconomic status…

  6. Free-surface stability criterion as affected by velocity distribution

    USGS Publications Warehouse

    Cheng-Lung, Chen

    1995-01-01

    This paper examines how the velocity distribution of flow in open channels affects the kinematic and dynamic wave velocities, from which the various forms of the Vedernikov number V can be formulated. When V >1, disturbances created in open-channel flow will amplify in the form of roll waves; when V <1, some (though not all) disturbances will attenuate. A study of the Vedernikov stability criterion reveals that it can be readily deduced within the framework of the kinematic and dynamic wave theories by comparing the kinematic wave velocity to the corresponding dynamic wave velocity. -from Author

  7. Stereotyped distribution of proliferating keratinocytes in disorders affecting the epidermis

    SciTech Connect

    Pierard-Franchimont, C.; Pierard, G.E.

    1989-06-01

    We used the technique of autoradiography after incorporation of tritiated thymidine (/sup 3/H-TdR) to evaluate keratinocyte proliferation in basal, epibasal, and other epidermal layers in 30 diseases affecting the epidermis. The number and proportion of /sup 3/H-TdR-labeled keratinocytes were counted in the different layers of the epidermis. Significant correlations were found between the proliferative indices of the different epidermal layers. Such links indicate that the epidermis responds in a rather stereotyped way to various pathological conditions. There exists some regulation in the distribution, number, and proportion of /sup 3/H-TdR-labeled keratinocytes in the various layers of the epidermis.

  8. Genetic diversity and geographical distribution of wild Saccharomyces cerevisiae strains from the wine-producing area of Charentes, France.

    PubMed Central

    Versavaud, A; Courcoux, P; Roulland, C; Dulau, L; Hallet, J N

    1995-01-01

    Electrophoretic karyotyping, mitochondrial DNA restriction fragment length polymorphism analysis, and PCR amplification of interspersed repeats were used to study the variability, phylogenetic affinities, and biogeographic distribution of wild Saccharomyces cerevisiae enological yeasts. The survey concentrated on 42 individual wine cellars in the Charentes area (Cognac region, France). A limited number (35) of predominant S. cerevisiae strains responsible for the fermentation process have been identified by the above molecular methods of differentiation. One strain (ACI) was found to be distributed over the entire area surveyed. There seemed to be little correlation between geographic location and genetic affinity. PMID:7486988

  9. The large-scale distribution of ammonia oxidizers in paddy soils is driven by soil pH, geographic distance, and climatic factors

    PubMed Central

    Hu, Hang-Wei; Zhang, Li-Mei; Yuan, Chao-Lei; Zheng, Yong; Wang, Jun-Tao; Chen, Deli; He, Ji-Zheng

    2015-01-01

    Paddy soils distribute widely from temperate to tropical regions, and are characterized by intensive nitrogen fertilization practices in China. Mounting evidence has confirmed the functional importance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in soil nitrification, but little is known about their biogeographic distribution patterns in paddy ecosystems. Here, we used barcoded pyrosequencing to characterize the effects of climatic, geochemical and spatial factors on the distribution of ammonia oxidizers from 11 representative rice-growing regions (75–1945 km apart) of China. Potential nitrification rates varied greatly by more than three orders of magnitude, and were significantly correlated with the abundances of AOA and AOB. The community composition of ammonia oxidizer was affected by multiple factors, but changes in relative abundances of the major lineages could be best predicted by soil pH. The alpha diversity of AOA and AOB displayed contrasting trends over the gradients of latitude and atmospheric temperature, indicating a possible niche separation between AOA and AOB along the latitude. The Bray–Curtis dissimilarities in ammonia-oxidizing community structure significantly increased with increasing geographical distance, indicating that more geographically distant paddy fields tend to harbor more dissimilar ammonia oxidizers. Variation partitioning analysis revealed that spatial, geochemical and climatic factors could jointly explain majority of the data variation, and were important drivers defining the ecological niches of AOA and AOB. Our findings suggest that both AOA and AOB are of functional importance in paddy soil nitrification, and ammonia oxidizers in paddy ecosystems exhibit large-scale biogeographic patterns shaped by soil pH, geographic distance, and climatic factors. PMID:26388866

  10. The large-scale distribution of ammonia oxidizers in paddy soils is driven by soil pH, geographic distance, and climatic factors.

    PubMed

    Hu, Hang-Wei; Zhang, Li-Mei; Yuan, Chao-Lei; Zheng, Yong; Wang, Jun-Tao; Chen, Deli; He, Ji-Zheng

    2015-01-01

    Paddy soils distribute widely from temperate to tropical regions, and are characterized by intensive nitrogen fertilization practices in China. Mounting evidence has confirmed the functional importance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in soil nitrification, but little is known about their biogeographic distribution patterns in paddy ecosystems. Here, we used barcoded pyrosequencing to characterize the effects of climatic, geochemical and spatial factors on the distribution of ammonia oxidizers from 11 representative rice-growing regions (75-1945 km apart) of China. Potential nitrification rates varied greatly by more than three orders of magnitude, and were significantly correlated with the abundances of AOA and AOB. The community composition of ammonia oxidizer was affected by multiple factors, but changes in relative abundances of the major lineages could be best predicted by soil pH. The alpha diversity of AOA and AOB displayed contrasting trends over the gradients of latitude and atmospheric temperature, indicating a possible niche separation between AOA and AOB along the latitude. The Bray-Curtis dissimilarities in ammonia-oxidizing community structure significantly increased with increasing geographical distance, indicating that more geographically distant paddy fields tend to harbor more dissimilar ammonia oxidizers. Variation partitioning analysis revealed that spatial, geochemical and climatic factors could jointly explain majority of the data variation, and were important drivers defining the ecological niches of AOA and AOB. Our findings suggest that both AOA and AOB are of functional importance in paddy soil nitrification, and ammonia oxidizers in paddy ecosystems exhibit large-scale biogeographic patterns shaped by soil pH, geographic distance, and climatic factors. PMID:26388866

  11. Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations.

    PubMed

    Ma, Jincai; Ibekwe, A Mark; Yang, Ching-Hong; Crowley, David E

    2016-09-01

    Microbial diversity of agricultural soils has been well documented, but information on leafy green producing soils is limited. In this study, we investigated microbial diversity and community structures in 32 (16 organic, 16 conventionally managed soils) from California (CA) and Arizona (AZ) using pyrosequencing, and identified factors affecting bacterial composition. Results of detrended correspondence analysis (DCA) and dissimilarity analysis showed that bacterial community structures of conventionally managed soils were similar to that of organically managed soils; while the bacterial community structures in soils from Salinas, California were different (P<0.05) from those in soils from Yuma, Arizona and Imperial Valley, California. Canonical correspondence analysis (CCA) and artificial neural network (ANN) analysis of bacterial community structures and soil variables showed that electrical conductivity (EC), clay content, water-holding capacity (WHC), pH, total nitrogen (TN), and organic carbon (OC) significantly (P<0.05) correlated with microbial communities. CCA based variation partitioning analysis (VPA) showed that soil physical properties (clay, EC, and WHC), soil chemical variables (pH, TN, and OC) and sampling location explained 16.3%, 12.5%, and 50.9%, respectively, of total variations in bacterial community structure, leaving 13% of the total variation unexplained. Our current study showed that bacterial community composition and diversity in major fresh produce growing soils from California and Arizona is a function of soil physiochemical characteristics and geographic distances of sampling sites. PMID:27135583

  12. Redefining the Australian Anthrax Belt: Modeling the Ecological Niche and Predicting the Geographic Distribution of Bacillus anthracis

    PubMed Central

    Barro, Alassane S.; Fegan, Mark; Moloney, Barbara; Porter, Kelly; Muller, Janine; Warner, Simone; Blackburn, Jason K.

    2016-01-01

    The ecology and distribution of B. anthracis in Australia is not well understood, despite the continued occurrence of anthrax outbreaks in the eastern states of the country. Efforts to estimate the spatial extent of the risk of disease have been limited to a qualitative definition of an anthrax belt extending from southeast Queensland through the centre of New South Wales and into northern Victoria. This definition of the anthrax belt does not consider the role of environmental conditions in the distribution of B. anthracis. Here, we used the genetic algorithm for rule-set prediction model system (GARP), historical anthrax outbreaks and environmental data to model the ecological niche of B. anthracis and predict its potential geographic distribution in Australia. Our models reveal the niche of B. anthracis in Australia is characterized by a narrow range of ecological conditions concentrated in two disjunct corridors. The most dominant corridor, used to redefine a new anthrax belt, parallels the Eastern Highlands and runs from north Victoria to central east Queensland through the centre of New South Wales. This study has redefined the anthrax belt in eastern Australia and provides insights about the ecological factors that limit the distribution of B. anthracis at the continental scale for Australia. The geographic distributions identified can help inform anthrax surveillance strategies by public and veterinary health agencies. PMID:27280981

  13. Redefining the Australian Anthrax Belt: Modeling the Ecological Niche and Predicting the Geographic Distribution of Bacillus anthracis.

    PubMed

    Barro, Alassane S; Fegan, Mark; Moloney, Barbara; Porter, Kelly; Muller, Janine; Warner, Simone; Blackburn, Jason K

    2016-06-01

    The ecology and distribution of B. anthracis in Australia is not well understood, despite the continued occurrence of anthrax outbreaks in the eastern states of the country. Efforts to estimate the spatial extent of the risk of disease have been limited to a qualitative definition of an anthrax belt extending from southeast Queensland through the centre of New South Wales and into northern Victoria. This definition of the anthrax belt does not consider the role of environmental conditions in the distribution of B. anthracis. Here, we used the genetic algorithm for rule-set prediction model system (GARP), historical anthrax outbreaks and environmental data to model the ecological niche of B. anthracis and predict its potential geographic distribution in Australia. Our models reveal the niche of B. anthracis in Australia is characterized by a narrow range of ecological conditions concentrated in two disjunct corridors. The most dominant corridor, used to redefine a new anthrax belt, parallels the Eastern Highlands and runs from north Victoria to central east Queensland through the centre of New South Wales. This study has redefined the anthrax belt in eastern Australia and provides insights about the ecological factors that limit the distribution of B. anthracis at the continental scale for Australia. The geographic distributions identified can help inform anthrax surveillance strategies by public and veterinary health agencies. PMID:27280981

  14. Epidemiology of childhood brain tumours in Yorkshire, UK, 1974-95: geographical distribution and changing patterns of occurrence.

    PubMed Central

    McKinney, P. A.; Parslow, R. C.; Lane, S. A.; Bailey, C. C.; Lewis, I.; Picton, S.; Cartwright, R. A.

    1998-01-01

    From a high-quality population-based register of children with cancer, 455 cases diagnosed with central nervous system (CNS) tumours were analysed to examine patterns of occurrence and geographical distribution. There was a significant increase of 1.8% (95% CI 0.5-3.1, P < 0.01) in average annual incidence for all CNS tumours, mainly accounted for by a 3.1% rise (95% CI 0.1-6.1, P < 0.05) in primitive neuroectodermal tumours (PNETs) over the 22-year period 1974-95. These increases were not explained by an increase in the proportion of histologically verified tumours. In the most recent time period (1986-95), astrocytomas occurred more commonly than previously in 0 to 4-year olds. Geographical differences in incidence were evident at a large scale, between counties, for all tumours and astrocytomas, with lower rates in the most urbanized areas. At the level of census district and electoral wards, no association between incidence of CNS tumours and socioeconomic group, person-based population density or ethnicity was observed using Poisson regression modelling. Based on small-scale census geography, the patterns of distribution of CNS tumours do not suggest strong associations with geographical determinants of risk. This study finds a rising incidence of all CNS tumours and particularly primitive neuroectodermal tumours and shows that astrocytomas appear to be occurring at a younger age, most probably because of improved diagnosis with non-invasive technology. PMID:9764594

  15. Co-infection patterns and geographic distribution of a complex pathosystem targeted by pathogen-resistant plants.

    PubMed

    Biddle, J M; Linde, C; Godfree, R C

    2012-01-01

    Increasingly, pathogen-resistant (PR) plants are being developed to reduce the agricultural impacts of disease. However PR plants also have the potential to result in increased invasiveness of nontarget host populations and so pose a potential threat to nontarget ecosystems. In this paper we use a new framework to investigate geographical variation in the potential risk associated with unintended release of genetically modified alfalfa mosaic virus (AMV)-resistant Trifolium repens (white clover) into nontarget host populations containing AMV, clover yellow vein virus (ClYVV), and white clover mosaic virus (WCIMV) in southeastern Australia. Surveys of 213 sites in 37 habitat types over a 300 000-km2 study region showed that T. repens is a significant weed of many high-conservation-value habitats in southeastern Australia and that AMV, ClYVV, and WClMV occur in 15-97% of nontarget host populations. However, T. repens abundance varied with site disturbance, habitat conservation value, and proximity to cropping, and all viral pathogens had distinct geographic distributions and infection patterns. Virus species frequently co-infected host plants and displayed nonindependent distributions within host populations, although co-infection patterns varied across the study region. Our results clearly illustrate the complexity of conducting environmental risk assessments that involve geographically widespread, invasive pasture species and demonstrate the general need for targeted, habitat- and pathosystem-specific studies prior to the process of tiered risk assessment. PMID:22471074

  16. Geographic distribution of Vertisols and Vertic soils in Russia: diversity of soils and landscapes

    NASA Astrophysics Data System (ADS)

    Khitrov, Nikolay; Chizhikova, Nataliya; Rogovneva, Ludmila

    2013-04-01

    There is a little information about geographic distribution of Vertisols and Vertic soils in Russia. Large areas of these soils (known in Russia as slitozems) are described in the Northen Caucasus Region (Bistritzkaya, Tyuryukanov, 1971; Khitrov, 2003). Swelling clay alluvial soils with microrelief gilgai were studied within the Volga-Akhtuba floodplain (Kozlovskyi, Kornblum, 1972). These and some other regions with slitozems in Russia are between latitudes 45 N and 48 N. For the north from latitude 48 N these soils have not been noted until 2006. Recently a lot of new areas of Vertisols and Vertic soils were identified in the Central Chernozemic Region of Russia (Khitrov, 2012) and in the Middle and the Lower Volga Region between latitudes 48 N and 54 N on the basis of soil studies along routes and on key plots. The portion of these soils in the soil cover patterns varies from 0,5 to 15-30%. Some areas of Vertisols and/or Vertic soils are up to 40-200 ha and more. With that their portion in the soil cover of the entire landscape is much less than 1%. All the delineated areas of vertic soils are confined to the outcrops of swelling clay sediments of different origins (marine, lacustrine, glacial, colluvial and alluvial materials) and ages (Jurassic, Cretaceous, Paleogene, Neogene, Quaternary). Mineral composition of clay fraction consists of smectites, irregular stratified illite-smectite, chlorite-smectite, hydromicas, chlorite and kaolinite in different proportions. Vertisols and Vertic soils may be found in different landscape positions that provides contrast water regime of soil including alternate periods of intense wetting and drying. The landscape positions are: (1) the step-like interfluvial surfaces and/or different concave slopes with swelling clay outcrops; (2) the deep closed depressions within vast flat watersheds; (3) the bottoms of wide hollows on interfluvial slopes; (4) different geomorphic positions in hydromorphic solonetzic complexes; (5) the

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

    PubMed

    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. PMID:26103689

  18. Rain-fed fig yield as affected by rainfall distribution

    NASA Astrophysics Data System (ADS)

    Bagheri, Ensieh; Sepaskhah, Ali Reza

    2014-08-01

    Variable annual rainfall and its uneven distribution are the major uncontrolled inputs in rain-fed fig production and possibly the main cause of yield fluctuation in Istahban region of Fars Province, I.R. of Iran. This introduces a considerable risk in rain-fed fig production. The objective of this study was to find relationships between seasonal rainfall distribution and rain-fed fig production in Istahban region to determine the critical rainfall periods for rain-fed fig production and supplementary irrigation water application. Further, economic analysis for rain-fed fig production was considered in this region to control the risk of production. It is concluded that the monthly, seasonal and annual rainfall indices are able to show the effects of rainfall and its distribution on the rain-fed fig yield. Fig yield with frequent occurrence of 80 % is 374 kg ha-1. The internal rates of return for interest rate of 4, 8 and 12 % are 21, 58 and 146 %, respectively, that are economically feasible. It is concluded that the rainfall in spring especially in April and in December has negatively affected fig yield due to its interference with the life cycle of Blastophaga bees for pollination. Further, it is concluded that when the rainfall is limited, supplementary irrigation can be scheduled in March.

  19. [Plea for a spatialization of demographic growth. Geographic distribution of the population and management of natural resources in the Sahel].

    PubMed

    Ouedraogo, D

    1994-05-01

    The Sahel is characterized by low productivity and unequal distribution of the population and of natural resources. Demographic growth is accompanied by a spatial unequal redistribution of the population, essentially caused by migratory movements. Geographic distribution of the population still follows that of natural resources, especially water which determines agricultural activities. Researchers must remember different spatial levels in the analysis for the interventions most effective on the ground. One fundamental question that is still avoided is: In what Sahelian towns will the 43 million citizens still be living in 2020? Another question is: What pattern of rural supplying of people will there be for the future? Research between natural resource needs of a growing population (3.1%/year) and the need for better management of these resources assumes great importance for sustainable development in the Sahel. Actions aiming to intensify agricultural production and preservation of natural resources are more and more reaffirmed by those tending to reduce the demand in these resources thanks to the control of demographic growth in the Sahel. But the reach of these actions will remain limited so long as they will not be trimmed to different spatial scales. Natural resources are unequally distributed to the Sahel. On the strictly demographic plan, the geographic distribution of the population and its evolution linked to the migratory fluxes constitute some variable keys that one will not know how to continue to escape in the construction of true sustainable development in the Sahel. PMID:12288132

  20. Geographic distribution of cryptic species of Plasmopara viticola causing downy mildew on wild and cultivated grape in eastern North America.

    PubMed

    Rouxel, Mélanie; Mestre, Pere; Baudoin, Anton; Carisse, Odile; Delière, Laurent; Ellis, Michael A; Gadoury, David; Lu, Jiang; Nita, Mizuho; Richard-Cervera, Sylvie; Schilder, Annemiek; Wise, Alice; Delmotte, François

    2014-07-01

    The putative center of origin of Plasmopara viticola, the causal agent of grape downy mildew, is eastern North America, where it has been described on several members of the family Vitaceae (e.g., Vitis spp., Parthenocissus spp., and Ampelopsis spp.). We have completed the first large-scale sampling of P. viticola isolates across a range of wild and cultivated host species distributed throughout the above region. Sequencing results of four partial genes indicated the presence of a new P. viticola species on Vitis vulpina in Virginia, adding to the four cryptic species of P. viticola recently recorded. The phylogenetic analysis also indicated that the P. viticola species found on Parthenocissus quinquefolia in North America is identical to Plasmopara muralis in Europe. The geographic distribution and host range of five pathogen species was determined through analysis of the internal transcribed spacer polymorphism of 896 isolates of P. viticola. Among three P. viticola species found on cultivated grape, one was restricted to Vitis interspecific hybrids within the northern part of eastern North America. A second species was recovered from V. vinifera and V. labrusca, and was distributed across most of the sampled region. A third species, although less abundant, was distributed across a larger geographical range, including the southern part of eastern North America. P. viticola clade aestivalis predominated (83% of isolates) in vineyards of the European winegrape V. vinifera within the sampled area, indicating that a single pathogen species may represent the primary threat to the European host species within eastern North America. PMID:24915427

  1. Sectoral and geographical contributions to summertime continental United States (CONUS) black carbon spatial distributions

    NASA Astrophysics Data System (ADS)

    Huang, Min; Carmichael, Gregory R.; Kulkarni, Sarika; Streets, David G.; Lu, Zifeng; Zhang, Qiang; Pierce, R. Bradley; Kondo, Yutaka; Jimenez, Jose L.; Cubison, Michael J.; Anderson, Bruce; Wisthaler, Armin

    2012-05-01

    The sectoral and regional contributions from northern hemisphere anthropogenic and biomass burning emission sectors to black carbon (BC) distributions over the continental United States (CONUS) in summer 2008 are studied using the Sulfur Transport and dEposition Model (STEM). North American (NA) emissions heavily (>70% of total emissions) affect the BC levels from the surface to ˜5 km, while non-NA plumes compose more than half of the BC above ˜5 km. Among all sectors, NA and non-NA biomass burning, NA transportation and non-NA residential emissions are the major contributors. The sectoral contributions vary among ten regions defined by the US Environmental Protection Agency (EPA): NA anthropogenic emissions enhance northeastern US BC levels; biomass burning strongly impacts northern California and southeastern US; and the influence of extra-regional plumes is largest in the northwestern US but extends to eastern US. The mean contribution from non-NA sources to US surface BC is ˜0.05 μg m-3, with a maximum value of ˜0.11 μg m-3 in the northwestern US. The non-NA contributions to column BC are higher than to surface BC, ranging from 30% to 80%, depending on region. EPA region 8 is most sensitive to extra-regional BC, partially explaining the observed increasing BC trend there during the past decades associated with the increasing Asian BC emissions. Measurements from the June 24 DC-8 flight during the ARCTAS-CARB field campaign show that BC/(organic matter + nitrate + sulfate) mass ratios fairly well represent BC's warming potential over southern California, which can be approximated by BC/(organic matter + sulfate) and BC/sulfate for plumes affected and unaffected by fires, respectively. The responses of BC/(organic matter + sulfate) and BC/sulfate to removing each emission sector are further discussed, indicating that mitigating NA transportation emissions has the highest potential for regional air quality and climate co-benefits.

  2. Geographic distribution of HIV stigma among women of childbearing age in rural Kenya

    PubMed Central

    Akullian, Adam; Kohler, Pamela; Kinuthia, John; Laserson, Kayla; Mills, Lisa A.; Okanda, John; Olilo, George; Ombok, Maurice; Odhiambo, Frank; Rao, Deepa; Wakefield, Jonathan; John-Stewart, Grace

    2015-01-01

    Objective(s) HIV stigma is considered to be a major driver of the HIV/AIDS pandemic, yet there is a limited understanding of its occurrence. We describe the geographic patterns of two forms of HIV stigma in a cross-sectional sample of women of childbearing age from western Kenya: internalized stigma (associated with shame) and externalized stigma (associated with blame). Design Geographic studies of HIV stigma provide a first step in generating hypotheses regarding potential community-level causes of stigma and may lead to more effective community-level interventions. Methods Spatial regression using generalized additive models and point pattern analyses using K-functions were used to assess the spatial scale(s) at which each form of HIV stigma clusters, and to assess whether the spatial clustering of each stigma indicator was present after adjustment for individual-level characteristics. Results There was evidence that externalized stigma (blame) was geographically heterogeneous across the study area, even after controlling for individual-level factors (P=0.01). In contrast, there was less evidence (P=0.70) of spatial trend or clustering of internalized stigma (shame). Conclusion Our results may point to differences in the underlying social processes motivating each form of HIV stigma. Externalized stigma may be driven more by cultural beliefs disseminated within communities, whereas internalized stigma may be the result of individual-level characteristics outside the domain of community influence. These data may inform community-level interventions to decrease HIV-related stigma, and thus impact the HIV epidemic. PMID:24835356

  3. Synopsis of the hard ticks (Acari: Ixodidae) of Romania with update on host associations and geographical distribution.

    PubMed

    Mihalca, A D; Dumitrache, M O; Magdaş, C; Gherman, C M; Domşa, C; Mircean, V; Ghira, I V; Pocora, V; Ionescu, D T; Sikó Barabási, S; Cozma, V; Sándor, A D

    2012-10-01

    The current paper is a synoptic review of the distribution and host associations of the 25 species of hard tick fauna (family Ixodidae) in Romania. In addition to a full literature survey, original data is presented, based on eight years of occasional or targeted sample collection. The literature data on geographical distribution was transposed digitally to the decimal degree coordinate system. For each species, an updated distribution map is given together with all historical data and new host associations. Overall, our paper records 58 new tick-host associations for Romania: 20 for Ixodes ricinus, 1 for I. apronophorus, 6 for I. arboricola, 2 for I. hexagonus, 9 for I. redikorzevi, 1 for I. trianguliceps, 2 for I. vespertilionis, 2 for Haemaphysalis punctata, 1 for H. sulcata, 2 for H. concinna, 1 for D. marginatus, 4 for Rhipicephalus sanguineus sensu lato, 1 for R. bursa and 6 for Hyalomma marginatum. PMID:22544174

  4. Plant Host Species and Geographic Distance Affect the Structure of Aboveground Fungal Symbiont Communities, and Environmental Filtering Affects Belowground Communities in a Coastal Dune Ecosystem.

    PubMed

    David, Aaron S; Seabloom, Eric W; May, Georgiana

    2016-05-01

    Microbial symbionts inhabit tissues of all plants and animals. Their community composition depends largely on two ecological processes: (1) filtering by abiotic conditions and host species determining the environments that symbionts are able to colonize and (2) dispersal-limitation determining the pool of symbionts available to colonize a given host and community spatial structure. In plants, the above- and belowground tissues represent such distinct habitats for symbionts that we expect different effects of filtering and spatial structuring on their symbiont communities. In this study, we characterized above- and belowground communities of fungal endophytes--fungi living asymptomatically within plants--to understand the contributions of filtering and spatial structure to endophyte community composition. We used a culture-based approach to characterize endophytes growing in leaves and roots of three species of coastal beachgrasses in dunes of the USA Pacific Northwest. For leaves, endophyte isolation frequency and OTU richness depended primarily on plant host species. In comparison, for roots, both isolation frequency and OTU richness increased from the nutrient-poor front of the dune to the higher-nutrient backdune. Endophyte community composition in leaves exhibited a distance-decay relationship across the region. In a laboratory assay, faster growth rates and lower spore production were more often associated with leaf- than root-inhabiting endophytes. Overall, our results reveal a greater importance of biotic filtering by host species and dispersal-limitation over regional geographic distances for aboveground leaf endophyte communities and stronger effects of abiotic environmental filtering and locally patchy distributions for belowground root endophyte communities. PMID:26626912

  5. Geographic distribution and relative abundance of the invasive glassy-winged sharpshooter: effects of temperature and egg parasitoids.

    PubMed

    Gutierrez, Andrew Paul; Ponti, Luigi; Hoddle, Mark; Almeida, Rodrigo P P; Irvin, Nicola A

    2011-08-01

    The capacity to predict the geographic distribution and relative abundance of invasive species is pivotal to developing policy for eradication or control and management. Commonly used methods fall under the ambit of ecological niche models (ENMs). These methods were reviewed and shortcomings identified. Weather-driven physiologically based demographic models (PBDMs) are proposed that resolve many of the deficiencies of ENMs. The PBDM approach is used to analyze the invasiveness of the polyphagous glassy-winged sharpshooter (Homalodisca vitripennis [Germar]), a pest native to the southeastern United States and northeastern Mexico that extended its range into California in 1989. Glassy-winged sharpshooter vectors the pathogenic bacterium, Xylella fastidiosa (Wells) that causes Pierce's disease in grape and scorch-like diseases in other plants. PBDMs for glassy-winged sharpshooter and its egg parasitoids (Gonatocerus ashmeadi Girault and G. triguttatus Girault) were developed and linked to a PBDM for grape published by Wermelinger et al. (1991). Daily weather data from 108 locations across California for the period 1995-2006 were used to drive the PBDM system, and GRASS GIS was used to map the simulation results. The geographic distribution of glassy-winged sharpshooter, as observed, is predicted to be largely restricted to the warm areas of southern California, with the action of the two egg parasitoids reducing its abundance >90%. The average indispensable mortality contributed by G. triguttatus is <1%. A temperature-dependent developmental rate model for X. fastidiosa was developed that suggests its geographic range is also limited to the warm inland areas of southern California. Biological control of glassy-winged sharpshooter further decreases the pathogen's relative range. Climate warming scenarios of +2°C and +3°C suggest that the distribution and severity of glassy-winged sharpshooter and X. fastidiosa will increase in the agriculturally rich central valley

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

    PubMed

    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. PMID:26888753

  7. The potential effect of global warming on the geographic and seasonal distribution of Phlebotomus papatasi in Southwest Asia

    SciTech Connect

    Cross, E.R.; Hyams, K.C.

    1996-07-01

    The distribution of Phlebotomus papatasi in Southwest Asia is thought to be highly dependent on temperature and relative humidity. A discriminant analysis model based on weather data and reported vector surveys was developed to predict the seasonal and geographic distribution of P. papatasi in this region. To simulate global warming, temperature values for 115 weather stations were increased by 1 {degrees}C, 3{degrees}C, and 5{degrees}C, and the outcome variable coded as unknown in the model. Probability of occurrence values were then predicted for each location with a weather station. Stations with positive probability of occurrence values for May, June, July, and August were considered locations where two or more life cycles of P. papatasi could occur and which could support endemic transmission of leishmaniasis and sandfly fever. Among 115 weather stations, 71 (62%) would be considered endemic with current temperature conditions; 14 (12%) additional station could become endemic with an increase of 1 {degrees}C; 17 (15%) more than a 3{degrees}C increase; and 12 (10%) more (all but one station) with a t{degrees}C increase. In addition to increased geographic distribution, seasonality of disease transmission could be extended throughout 12 months of the year in 7 (6%) locations with at least a 3{degrees}C rise in temperature and in 29 (25%) locations with a 5{degrees}C rise. 15 refs., 4 figs.

  8. GEOGRAPHIC DISTRIBUTION AND MOLECULAR DIVERSITY OF BARTONELLA SPP. INFECTIONS IN MOOSE (ALCES ALCES) IN FINLAND.

    PubMed

    Pérez Vera, Cristina; Aaltonen, Kirsi; Spillmann, Thomas; Vapalahti, Olli; Sironen, Tarja

    2016-04-28

    Moose, Alces alces (Artiodactyla: Cervidae) in Finland are heavily infested with deer keds, Lipoptena cervi (Diptera: Hippoboschidae). The deer ked, which carries species of the genus Bartonella, has been proposed as a vector for the transmission of bartonellae to animals and humans. Previously, bartonella DNA was found in deer keds as well as in moose blood collected in Finland. We investigated the prevalence and molecular diversity of Bartonella spp. infection from blood samples collected from free-ranging moose. Given that the deer ked is not present in northernmost Finland, we also investigated whether there were geographic differences in the prevalence of bartonella infection in moose. The overall prevalence of bartonella infection was 72.9% (108/148). Geographically, the prevalence was highest in the south (90.6%) and lowest in the north (55.9%). At least two species of bartonellae were identified by multilocus sequence analysis. Based on logistic regression analysis, there was no significant association between bartonella infection and either age or sex; however, moose from outside the deer ked zone were significantly less likely to be infected (P<0.015) than were moose hunted within the deer ked zone. PMID:26967131

  9. The geographic distribution of radionuclide deposition across the continental US from atmospheric nuclear testing.

    PubMed

    Simon, Steven L; Bouville, André; Beck, Harold L

    2004-01-01

    For the first time, calculations for the more than 3000 counties of the US have been completed that estimate the average deposition density (Bq m(-2)) of more than 40 radionuclides in fallout from atmospheric nuclear weapons tests conducted in the US (1951-1962) and 19 radionuclides from tests conducted elsewhere in the world (1952-1963). The geographic pattern of deposition across the US, as well as the amount of fallout deposited, varied significantly depending on whether the tests were conducted within or outside of the US. Fallout deposited from the Nevada Test Site (NTS) varied geographically as a result of dispersion and dilution in the atmosphere, the wind patterns following each test, and the occurrence of localized rainfall events. In general, states immediately east of the NTS received the highest deposition from tests conducted there. In contrast, the variation in deposition across the country from global fallout was less than for NTS fallout primarily reflecting variations in annual precipitation across larger regions. Hence, in the eastern and mid-western US, where rainfall is above the national average, higher levels of global fallout were deposited than in the more arid southwestern states. This paper presents a summary of the methods used and findings of our studies on fallout from NTS and global fallout, with emphasis on two of the most important radionuclides, (131)I and (137)Cs. PMID:15063539

  10. An analysis of the geographical distribution of severe malaria in children in Kilifi District, Kenya.

    PubMed

    Schellenberg, J A; Newell, J N; Snow, R W; Mung'ala, V; Marsh, K; Smith, P G; Hayes, R J

    1998-04-01

    To investigate the geographic pattern of severe malaria and the stability of this pattern over time, all 358 children under 5 years of age admitted to a district hospital in Kenya's Kilifi District with severe malaria in 1991-93 and living in a rural study population of about 50,000 people were identified. All households were mapped through use of a hand-held satellite navigation system and the resulting databases were linked through a geographic information system. Area-specific rates showed evidence of association between the two years, suggesting that the pattern of disease was to some extent stable over time. As expected, hospital admissions for malaria were significantly higher in children with easier access to the hospital. Those living more than 25 km from the hospital had admission rates about one-fifth those for children living within 5 km of the hospital. Those living more than 2.5 km from the nearest road had admission rates about half those for children within 0.5 km of a road. Investigation of short-term local fluctuations in severe malaria revealed evidence of space-time clustering of severe malaria, supporting the view that severe malaria tends to occur in localized micro-epidemics. Recommended are case-control studies of environmental, genetic, and human behavioral factors involved in the etiology of the disease. PMID:9602418

  11. Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

    PubMed

    Greaves, M F; Colman, S M; Beard, M E; Bradstock, K; Cabrera, M E; Chen, P M; Jacobs, P; Lam-Po-Tang, P R; MacDougall, L G; Williams, C K

    1993-01-01

    Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy. PMID:8418376

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

    PubMed Central

    2012-01-01

    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, while municipalities

  13. Were the Late Pleistocene climatic changes responsible for the disappearance of the European spotted hyena populations? Hindcasting a species geographic distribution across time

    NASA Astrophysics Data System (ADS)

    Varela, Sara; Lobo, Jorge M.; Rodríguez, Jesús; Batra, Persaram

    2010-08-01

    This article examines the role of the Late Pleistocene climatic changes in the disappearance of the European populations of spotted hyenas. A species distribution model was built using both current and past environmental requirements of the species. Model projections were made with climatic scenarios provided by the GENESIS 2.0 General Circulation Model (126 ka, 42 ka, 30 ka and 21 ka). Those projections indicate (1) that during the Late Pleistocene warm scenarios spotted hyenas should have been widespread in Europe, and (2) that during the last glacial maximum their potential climatically suitable geographic distribution diminished in size. The decrease in the potential climatic distribution was strictly restricted to Northern Europe. Climatic conditions in Southern Europe during the Late Pleistocene remained within the spotted hyena climatic tolerance. Hence, climate changes could have directly affected the Northern distribution of the species during the last glaciations. However, climate change alone is not sufficient to have caused the disappearance of the spotted hyena populations in Southern Europe. That is, other factors, such as prey abundance or human ecological impacts, in addition to climatic change, are needed to completely account for extinction of the European spotted hyena.

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

    PubMed

    Ngui, Romano; Shafie, Aziz; Chua, Kek H; Mistam, Mohd S; Al-Mekhlafi, Hesham M; Sulaiman, Wan W W; Mahmud, Rohela; Lim, Yvonne A L

    2014-05-01

    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. PMID:24893014

  15. Polybrominated diphenyl ethers in resident Eurasian Tree Sparrow from Shanghai: geographical distribution and implication for potential sources.

    PubMed

    Tang, Wei-biao; Huang, Kai; Zhao, Jian-hua; Zhang, Zheng; Liang, Si; Liu, Lili; Zhang, Wei; Lin, Kuang-fei

    2015-05-01

    An investigation of polybrominated diphenyl ethers (PBDEs) in Eurasian Tree Sparrow (Passer montanus) samples (n=37) collected from different land use areas in Shanghai provided information about the levels, compositional patterns, geographical distribution, potential sources of PBDEs and the evaluation of contamination status in Shanghai. The concentrations of BDE 209 and Sum-PBDEs were within the range of 8.20-292.0 ng g(-1) lw (median: 47.0 ng g(-1) lw) and 33.16-375.63 ng g(-1) lw (median: 78.7 ng g(-1) lw), respectively. As the predominant individual congener, BDE 209 was detected in all samples with a mean percentage of 62.8%, followed by BDE 47, 99 and 100 sequentially. The geographical distribution of PBDEs in ETS muscles followed the order below: landfill>urban>industrial parks>suburban>rural>remote, indicating that Shanghai Laogang Municipal Landfill was an important emission source of PBDEs in Shanghai, and also the PBDE levels were in association with urbanization and industrialization. Compared with other regions, contamination status in Shanghai was relatively good with the exception of these high concentration areas. There was significant correlation (r(2)=0.89, P<0.01) between PBDEs concentrations in soil and ETS, indicating ETS could be used as a useful biomonitoring tool for PBDEs in Shanghai. PMID:25665899

  16. Genetic Variation and Structure in Contrasting Geographic Distributions: Widespread Versus Restricted Black-Tailed Prairie Dogs (Subgenus Cynomys).

    PubMed

    Castellanos-Morales, Gabriela; Ortega, Jorge; Castillo-Gámez, Reyna A; Sackett, Loren C; Eguiarte, Luis E

    2015-01-01

    Species of restricted distribution are considered more vulnerable to extinction because of low levels of genetic variation relative to widespread taxa. Species of the subgenus Cynomys are an excellent system to compare genetic variation and degree of genetic structure in contrasting geographic distributions. We assessed levels of genetic variation, genetic structure, and genetic differentiation in widespread Cynomys ludovicianus and restricted C. mexicanus using 1997bp from the cytochrome b and control region (n = 223 C. ludovicianus; 77 C. mexicanus), and 10 nuclear microsatellite loci (n = 207 and 78, respectively). Genetic variation for both species was high, and genetic structure in the widespread species was higher than in the restricted species. C. mexicanus showed values of genetic variation, genetic structure, and genetic differentiation similar to C. ludovicianus at smaller geographic scales. Results suggest the presence of at least 2 historical refuges for C. ludovicianus and that the Sierra Madre Occidental represents a barrier to gene flow. Chihuahua and New Mexico possess high levels of genetic diversity and should be protected, while Sonora should be treated as an independent management unit. For C. mexicanus, connectivity among colonies is very important and habitat fragmentation and habitat loss should be mitigated to maintain gene flow. PMID:26245783

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

    PubMed Central

    2012-01-01

    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. PMID:22410314

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

    USGS Publications Warehouse

    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

  19. Tackling intraspecific genetic structure in distribution models better reflects species geographical range.

    PubMed

    Marcer, Arnald; Méndez-Vigo, Belén; Alonso-Blanco, Carlos; Picó, F Xavier

    2016-04-01

    Genetic diversity provides insight into heterogeneous demographic and adaptive history across organisms' distribution ranges. For this reason, decomposing single species into genetic units may represent a powerful tool to better understand biogeographical patterns as well as improve predictions of the effects of GCC (global climate change) on biodiversity loss. Using 279 georeferenced Iberian accessions, we used classes of three intraspecific genetic units of the annual plant Arabidopsis thaliana obtained from the genetic analyses of nuclear SNPs (single nucleotide polymorphisms), chloroplast SNPs, and the vernalization requirement for flowering. We used SDM (species distribution models), including climate, vegetation, and soil data, at the whole-species and genetic-unit levels. We compared model outputs for present environmental conditions and with a particularly severe GCC scenario. SDM accuracy was high for genetic units with smaller distribution ranges. Kernel density plots identified the environmental variables underpinning potential distribution ranges of genetic units. Combinations of environmental variables accounted for potential distribution ranges of genetic units, which shrank dramatically with GCC at almost all levels. Only two genetic clusters increased their potential distribution ranges with GCC. The application of SDM to intraspecific genetic units provides a detailed picture on the biogeographical patterns of distinct genetic groups based on different genetic criteria. Our approach also allowed us to pinpoint the genetic changes, in terms of genetic background and physiological requirements for flowering, that Iberian A. thaliana may experience with a GCC scenario applying SDM to intraspecific genetic units. PMID:27066224

  20. At least some meiofaunal species are not everywhere. Indication of geographic, ecological and geological barriers affecting the dispersion of species of Ototyphlonemertes (Nemertea, Hoplonemertea).

    PubMed

    Leasi, Francesca; Andrade, Sónia Cristina da Silva; Norenburg, Jon

    2016-03-01

    Most meiofaunal species are known to have a broad distribution with no apparent barriers to their dispersion. However, different morphological and/or molecular methods supported patterns of diversity and distribution that may be different among taxa while also conflicting within the same group. We accurately assessed the patterns of geographic distribution in actual genetic species of a marine meiofaunal animal model: Ototyphlonemertes. Specimens were collected from several sites around Europe, Northern and Central America, Southern America, Pacific Islands and Asia. We sequenced regions of two mitochondrial and two nuclear genes. Using single-gene, a concatenated data set, multilocus approaches and different DNA taxonomy methods, we disentangled the actual diversity and the spatial structures of haplotypes and tested the possible correlation between genetic diversity and geographic distance. The results show (i) the importance of using several genes to uncover both diversity and highlight phylogeographic relationships among species and that (ii) independent genetic evolutionary entities have a narrower distribution than morphological species. Moreover, (iii) a Mantel test supported a positive correlation between genetic and geographical distance. By sampling from the two sides of Isthmus of Panama, we were additionally able to identify lineage divergence times that are concordant with vicariance mechanisms caused by the geological closure of the seaway across the Isthmus. We therefore propose that in addition to distance, other geological and ecological conditions are also barriers to the dispersion of and gene flow in marine meiofaunal organisms. PMID:26840255

  1. Squares of different sizes: effect of geographical projection on model parameter estimates in species distribution modeling.

    PubMed

    Budic, Lara; Didenko, Gregor; Dormann, Carsten F

    2016-01-01

    In species distribution analyses, environmental predictors and distribution data for large spatial extents are often available in long-lat format, such as degree raster grids. Long-lat projections suffer from unequal cell sizes, as a degree of longitude decreases in length from approximately 110 km at the equator to 0 km at the poles. Here we investigate whether long-lat and equal-area projections yield similar model parameter estimates, or result in a consistent bias. We analyzed the environmental effects on the distribution of 12 ungulate species with a northern distribution, as models for these species should display the strongest effect of projectional distortion. Additionally we choose four species with entirely continental distributions to investigate the effect of incomplete cell coverage at the coast. We expected that including model weights proportional to the actual cell area should compensate for the observed bias in model coefficients, and similarly that using land coverage of a cell should decrease bias in species with coastal distribution. As anticipated, model coefficients were different between long-lat and equal-area projections. Having progressively smaller and a higher number of cells with increasing latitude influenced the importance of parameters in models, increased the sample size for the northernmost parts of species ranges, and reduced the subcell variability of those areas. However, this bias could be largely removed by weighting long-lat cells by the area they cover, and marginally by correcting for land coverage. Overall we found little effect of using long-lat rather than equal-area projections in our analysis. The fitted relationship between environmental parameters and occurrence probability differed only very little between the two projection types. We still recommend using equal-area projections to avoid possible bias. More importantly, our results suggest that the cell area and the proportion of a cell covered by land should be

  2. Aflatoxin B1-induced hepatocellular carcinoma in developing countries: Geographical distribution, mechanism of action and prevention

    PubMed Central

    HAMID, ABDU SELIM; TESFAMARIAM, ISAIAS GOITOM; ZHANG, YUCHENG; ZHANG, ZHEN GUI

    2013-01-01

    Hepatocellular carcinoma (HCC) is the most well-known primary liver malignancy worldwide. Its incidence is rising at alarming rates and has become a public concern globally. It is more frequent in developing countries than in industrialized countries with respect to geographical variation, ethnic disparities and socioeconomic status. Dietary exposure to aflatoxins is among the major HCC risk factors. Aflatoxin B1, which is a genotoxic hepatocarcinogen, which presumptively causes cancer by inducing DNA adducts leading to genetic changes in target liver cells. AFB1 is metabolized by cytochrome-P450 enzymes to the reactive intermediate AFB1-8, 9 epoxide (AFBO) which binds to liver cell DNA, resulting in DNA adducts. DNA adducts interact with the guanine bases of liver cell DNA and cause a mutational effect in the P53 tumor suppressor gene at the codon 249 hotspot in exon 7, which may lead to HCC. Approximately 4.5 billion of the world’s population is exposed to aflatoxin-contaminated food, particularly in low-income countries. Prevention involves treating crops that are susceptible to fungal contamination, appropriate handling of foodstuffs and the use of chemopreventive intervention. Moreover, an integrated network collaboration of different sectors, including public health, agricultural departments and mass media, is required to ensure effective food regulation systems so as to minimize the contamination of food by aflatoxins. PMID:23599745

  3. Geographic Distribution and Inheritance of Three Cytoplasmic Incompatibility Types in Drosophila Simulans

    PubMed Central

    Montchamp-Moreau, C.; Ferveur, J. F.; Jacques, M.

    1991-01-01

    Wolbachia-like microorganisms have been implicated in unidirectional cytoplasmic incompatibility between strains of Drosophila simulans. Reduced egg eclosion occurs when females from uninfected strains (type W) are crossed with males from infected strains (type R). Here we characterize a third incompatibility type (type S) which is also correlated with the presence of Wolbachia-like microorganisms. Despite the fact that the symbionts cannot be morphologically distinguished, we observed complete bidirectional incompatibility between R and S strains. This indicates that the determinants of incompatibility are different in the two infected types. S/W incompatibility is unidirectional and similar to R/W incompatibility. A worldwide survey of D. simulans strains showed that type S incompatibility was found only in insular populations which harbor the mitochondrial type SiI. Both W and R types were found among mainland and island populations harboring the worldwide mitochondrial type SiII. Type S incompatibility could be involved in the reinforcement of the geographical isolation of SiI populations. PMID:1743484

  4. A Tabu Search WSN Deployment Method for Monitoring Geographically Irregular Distributed Events.

    PubMed

    Aitsaadi, Nadjib; Achir, Nadjib; Boussetta, Khaled; Pujolle, Guy

    2009-01-01

    In this paper, we address the Wireless Sensor Network (WSN) deployment issue. We assume that the observed area is characterized by the geographical irregularity of the sensed events. Formally, we consider that each point in the deployment area is associated a differentiated detection probability threshold, which must be satisfied by our deployment method. Our resulting WSN deployment problem is formulated as a Multi-Objectives Optimization problem, which seeks to reduce the gap between the generated events detection probabilities and the required thresholds while minimizing the number of deployed sensors. To overcome the computational complexity of an exact resolution, we propose an original pseudo-random approach based on the Tabu Search heuristic. Simulations show that our proposal achieves better performances than several other approaches proposed in the literature. In the last part of this paper, we generalize the deployment problem by including the wireless communication network connectivity constraint. Thus, we extend our proposal to ensure that the resulting WSN topology is connected even if a sensor communication range takes small values. PMID:22573977

  5. Geographic Distribution and Genetic Diversity of Ceanothus-Infective Frankia Strains†

    PubMed Central

    Ritchie, Nancy J.; Myrold, David D.

    1999-01-01

    Little is known about Ceanothus-infective Frankia strains because no Frankia strains that can reinfect the host plants have been isolated from Ceonothus spp. Therefore, we studied the diversity of the Ceonothus-infective Frankia strains by using molecular techniques. Frankia strains inhabiting root nodules of nine Ceanothus species were characterized. The Ceanothus species used represent the taxonomic diversity and geographic range of the genus; therefore, the breadth of the diversity of Frankia strains that infect Ceanothus spp. was studied. DNA was amplified directly from nodular material by using the PCR. The amplified region included the 3′ end of the 16S rRNA gene, the intergenic spacer, and a large portion of the 23S rRNA gene. A series of restriction enzyme digestions of the PCR product allowed us to identify PCR-restriction fragment length polymorphism (RFLP) groups among the Ceanothus-infective Frankia strains tested. Twelve different enzymes were used, which resulted in four different PCR-RFLP groups. The groups did not follow the taxonomic lines of the Ceanothus host species. Instead, the Frankia strains present were related to the sample collection locales. PMID:10103225

  6. Geographic distribution of co-dominant DNA stemlines in breast carcinoma

    SciTech Connect

    Visscher, D.; Dolan, P.; Ottosen, S.; Crissman, J.

    1995-09-01

    Breast carcinomas often contain multiple DNA stemlines in flow cytometric DNA histograms. However, due to mixing during tissue disaggregation the microanatomical relationship between the cells which comprise distinct stemlines is unclear. We performed image cytophotometric DNA analysis (IA) on two separate areas of intact tissue sections of 19 breast carcinomas which were selected on the basis of flow cytometric (FCM) DNA content heterogeneity (i.e., multiple stemlines). For comparison, similar analyses were performed on seven tumors with unimodal FCM DNA histograms. Six of the 7 tumors (86%) with unimodal FCM histograms were also unimodal in both IA DNA histograms. Among tumors with heterogeneous FCM DNA histograms, the presence of multiple stemlines was confirmed in IA DNA histograms in 16/19. In nine of these 16 cases, multiple DNA stemlines having similar DNA indices were present in both areas of neoplasm examined with IA. The remaining seven cases displayed unimodal IA histograms in both areas, however DNA indices differed between the two histograms. These findings imply that cell populations corresponding to flow cytometrically detected DNA stemlines are often intimately admixed, even within geographically separated portions of breast tumors. This pattern suggests that productive interactions between genetically distinct tumor populations may lead to stable co-dominance of ancestral clones during progression of some breast carcinomas. 12 refs., 4 tabs.

  7. Molecular phylogeny and geographic distribution of wood-feeding cockroaches in East Asian Islands.

    PubMed

    Maekawa, K; Lo, N; Kitade, O; Miura, T; Matsumoto, T

    1999-11-01

    Molecular phylogenetic relationships of the wood-feeding cockroach genera Salganea and Panesthia (Blaberidae; Panesthiinae) in East Asian Islands (Ryukyu archipelago and Taiwan Island) were analyzed based on the DNA sequence of the complete mitochondrial cytochrome oxidase II gene. Unweighted parsimony analysis resulted in high bootstrap support for relationships within Panesthia taxa; however, some nodes were unresolved between members of Salganea. Comparison of the number of transitions and transversions with genetic distance at each codon position suggested that saturation of third-codon substitutions has occurred between certain pairs of taxa. Consequently, differential weighting of substitutions at these sites was performed, which resulted in a substantial increase in resolution of Salganea relationships. The inferred phylogenies for both genera displayed good correspondence to the geographical locations of populations but however did not agree with previous subspecies designations based on morphological characters. It appears that both cockroach genera invaded the Ryukyu archipelago from the Taiwan region via a land-bridge present in the Miocene period. Invasion of the main islands of Japan by these cockroaches most likely occurred before the formation of the Tokara Tectonic Strait. Our study suggests that several barriers to gene flow have arisen and persisted over the past approximately 10 million years, which have caused segregation and vicariant speciation of the cockroach taxa of this region. PMID:10603264

  8. Distribution of steroidal saponins in Tribulus terrestris from different geographical regions.

    PubMed

    Dinchev, Dragomir; Janda, Bogdan; Evstatieva, Liuba; Oleszek, Wieslaw; Aslani, Mohammad R; Kostova, Ivanka

    2008-01-01

    The steroidal saponins of Tribulus terrestris L. (Zygophyllaceae) are considered to be the factor responsible for biological activity of products derived from this plant. The activity depends on the concentration and the composition of active saponins, which in turn is influenced by the geographical origin of plant material. Samples of T. terrestris collected in Bulgaria, Greece, Serbia, Macedonia, Turkey, Georgia, Iran, Vietnam and India were analyzed by LC-ESI/MS/MS for the presence and the concentration of protodioscin (1), prototribestin (2), pseudoprotodioscin (3), dioscin (4), tribestin (5) and tribulosin (6). The flavonoid rutin (7) was also included in the comparison. The results revealed distinct differences in the content of these compounds depending on region of sample collection, plant part studied and stage of plant development. The samples from Bulgaria, Turkey, Greece, Serbia, Macedonia, Georgia and Iran exhibited similar chemical profile and only some quantitative difference in the content of 1-7 with protodioscin (1) and prototribestin (2) as main components. The Vietnamese and Indian samples exhibit totally different chemical profile. They lack 2 and 5, while tribulosin (6) is present in high amounts. Compounds different from 1 to 7 are dominating in these 3 samples. The presented results suggested the existence of one chemotype common to the East South European and West Asian regions. Most probably, the Vietnamese and Indian samples belong to other chemotypes which are still to be studied and characterized. No clear correlation between the burrs morphology and the chemical composition of the samples has been found. PMID:17719068

  9. Geographical Structuring of Genetic Diversity Across the Whole Distribution Range of Narcissus longispathus, a Habitat-specialist, Mediterranean Narrow Endemic

    PubMed Central

    Medrano, Mónica; Herrera, Carlos M.

    2008-01-01

    Background and Aims High mountain ranges of the Mediterranean Basin harbour a large number of narrowly endemic plants. In this study an investigation is made of the levels and partitioning of genetic diversity in Narcissus longispathus, a narrow endemic of south-eastern Spanish mountains characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. By using dense sampling of populations across the species' whole geographical range, genetic structuring at different geographical scales is also examined. Methods Using horizontal starch-gel electrophoresis, allozyme variability was screened at 19 loci for a total of 858 individuals from 27 populations. The data were analysed by means of standard statistical approaches in order to estimate gene diversity and the genetic structure of the populations. Key Results Narcissus longispathus displayed high levels of genetic diversity and extensive diversification among populations. At the species level, the percentage of polymorphic loci was 68 %, with average values of 2·1, 0·11 and 0·14 for the number of alleles per locus, observed heterozygosity and expected heterozygosity, respectively. Southern and more isolated populations tended to have less genetic variability than northern and less-isolated populations. A strong spatial patterning of genetic diversity was found at the various spatial scales. Gene flow/drift equilibrium occurred over distances <4 km. Beyond that distance divergence was relatively more influenced by drift. The populations studied seem to derive from three panmictic units or ‘gene pools’, with levels of admixture being greatest in the central and south-eastern portions of the species' range. Conclusions In addition to documenting a case of high genetic diversity in a narrow endemic plant with naturally fragmented populations, the results emphasize the need for dense population sampling and examination of different geographical scales for understanding

  10. Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Forests: A Database

    SciTech Connect

    Brown, S

    2001-05-22

    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/INFOTM 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. This database includes ten ARC/INFO exported integer grid files (five with the pixel size 3.75 km x 3.75 km and five with the pixel size 0.25 degree longitude x 0.25 degree latitude) and 27 ASCII files. The first ASCII file contains the documentation associated with this database. Twenty-four of the ASCII files were generated by means of the ARC/INFO GRIDASCII command and can be used by most raster-based GIS software packages. The 24 files can be subdivided into two groups of 12 files each. These files contain real data values representing actual carbon and potential carbon density in Mg C/ha (1 megagram = 10{sup 6} grams) and integer-coded values for country name, Weck's Climatic Index, ecofloristic zone, elevation, forest or non-forest designation, population density, mean annual precipitation, slope, soil texture, and vegetation classification. One set of 12 files contains these data at a spatial resolution of 3.75 km, whereas the other

  11. Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Forests: A Database

    SciTech Connect

    Brown, S.

    2002-02-07

    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. This database includes ten ARC/INFO exported integer grid files (five with the pixel size 3.75 km x 3.75 km and five with the pixel size 0.25 degree longitude x 0.25 degree latitude) and 27 ASCII files. The first ASCII file contains the documentation associated with this database. Twenty-four of the ASCII files were generated by means of the ARC/INFO GRIDASCII command and can be used by most raster-based GIS software packages. The 24 files can be subdivided into two groups of 12 files each. These files contain real data values representing actual carbon and potential carbon density in Mg C/ha (1 megagram = 10{sup 6} grams) and integer- coded values for country name, Weck's Climatic Index, ecofloristic zone, elevation, forest or non-forest designation, population density, mean annual precipitation, slope, soil texture, and vegetation classification. One set of 12 files contains these data at a spatial resolution of 3.75 km, whereas

  12. The geographic distribution of cases of Crimean-Congo hemorrhagic fever: Kastamonu, Turkey.

    PubMed

    Aker, Servet; Akıncı, Halil; Kılıçoğlu, Cem; Leblebicioglu, Hakan

    2015-09-01

    The purpose of this study was to analyze the epidemiological characteristics of cases diagnosed with Crimean-Congo Hemorrhagic Fever (CCHF) with the help of Geographic Information Systems (GIS) and to establish an epidemiological risk map. Data for 434 cases diagnosed with CCHF between 01.01.2004 and 31.12.2013 were subjected to statistical analysis SPSS 13.0 software. A digital map of Kastamonu was transferred onto ArcGIS 10.0 software in order to establish a risk map for CCHF. The highest cumulative incidence of CCHF is 41.29/10,000, and in people living at altitudes of 1001-1200 meters. ROC analysis of altitudes above sea level of residences with CCHF cases revealed an area under the curve of 74.5% (95% CI: 0.72-0.76, p<0.05). At a cut-off point of 836.5 meters, sensitivity was 0.74 and specificity 0.76. Cumulative incidence of CCHF was significantly positively correlated with number of animals per head (r=0.76) and area of agricultural land per head (r=0.59) (p<0.05). No significant correlation was determined between cumulative incidence and forested area percentages. This study reveals that both men and women living at more than 836.5 meters above sea level and working in agriculture and animal husbandry are at risk of CCHF between May and July. Detailed examination of the ecology of vector ticks is now needed in order to fully determine the epidemiology of the disease. PMID:26139033

  13. Geographic Distribution of Environmental Relative Moldiness Index (ERMI) in U.S. Homes

    EPA Science Inventory

    The objective of this study was to quantify and describe the distribution of the 36 settled dust molds that make up the Environmental Relative Moldiness Index (ERMI). Materials and Methods. As part of the 2006 American Healthy Homes Survey, settled dust samples were analyzed by ...

  14. MartiTracks: a geometrical approach for identifying geographical patterns of distribution.

    PubMed

    Echeverría-Londoño, Susy; Miranda-Esquivel, Daniel Rafael

    2011-01-01

    Panbiogeography represents an evolutionary approach to biogeography, using rational cost-efficient methods to reduce initial complexity to locality data, and depict general distribution patterns. However, few quantitative, and automated panbiogeographic methods exist. In this study, we propose a new algorithm, within a quantitative, geometrical framework, to perform panbiogeographical analyses as an alternative to more traditional methods. The algorithm first calculates a minimum spanning tree, an individual track for each species in a panbiogeographic context. Then the spatial congruence among segments of the minimum spanning trees is calculated using five congruence parameters, producing a general distribution pattern. In addition, the algorithm removes the ambiguity, and subjectivity often present in a manual panbiogeographic analysis. Results from two empirical examples using 61 species of the genus Bomarea (2340 records), and 1031 genera of both plants and animals (100118 records) distributed across the Northern Andes, demonstrated that a geometrical approach to panbiogeography is a feasible quantitative method to determine general distribution patterns for taxa, reducing complexity, and the time needed for managing large data sets. PMID:21533259

  15. MODELING THE POTENTIAL SPATIAL DISTRIBUTION OF BEEF CATTLE GRAZING USING A GEOGRAPHIC INFORMATION SYSTEM

    EPA Science Inventory

    Data regarding grazing utilization in the western United States are typically compiled within administrative boundaries(e.g. allotment,pasture). For large areas, an assumption of uniform distribution is seldom valid. Previous studies show that vegetation type, degree of slope, an...

  16. Geographic Distribution of Habitat, Development, and Population Growth Rates of the Asian Citrus Psyllid, Diaphorina citri, in Mexico

    PubMed Central

    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. PMID:24735280

  17. Molecular diagnosis of pediatric patients with citrin deficiency in China: SLC25A13 mutation spectrum and the geographic distribution

    PubMed Central

    Lin, Wei-Xia; Zeng, Han-Shi; Zhang, Zhan-Hui; Mao, Man; Zheng, Qi-Qi; Zhao, Shu-Tao; Cheng, Ying; Chen, Feng-Ping; Wen, Wang-Rong; Song, Yuan-Zong

    2016-01-01

    Citrin deficiency (CD) is a Mendelian disease due to biallelic mutations of SLC25A13 gene. Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) is the major pediatric CD phenotype, and its definite diagnosis relies on SLC25A13 genetic analysis. China is a vast country with a huge population, but the SLC25A13 genotypic features of CD patients in our country remains far from being well clarified. Via sophisticated molecular analysis, this study diagnosed 154 new CD patients in mainland China and identified 9 novel deleterious SLC25A13 mutations, i.e. c.103A > G, [c.329 − 154_c.468 + 2352del2646; c.468 + 2392_c.468 + 2393ins23], c.493C > T, c.755 − 1G > C, c.845_c.848 + 1delG, c.933_c.933 + 1insGCAG, c.1381G > T, c.1452 + 1G > A and c.1706_1707delTA. Among the 274 CD patients diagnosed by our group thus far, 41 SLC25A13 mutations/variations were detected. The 7 mutations c.775C > T, c.851_854del4, c.1078C > T, IVS11 + 1G > A, c.1364G > T, c.1399C > T and IVS16ins3kb demonstrated significantly different geographic distribution. Among the total 53 identified genotypes, only c.851_854del4/c.851_854del4 and c.851_854del4/c.1399C > T presented different geographic distribution. The northern population had a higher level of SLC25A13 allelic heterogeneity than those in the south. These findings enriched the SLC25A13 mutation spectrum and brought new insights into the geographic distribution of the variations and genotypes, providing reliable evidences for NICCD definite diagnosis and for the determination of relevant molecular targets in different Chinese areas. PMID:27405544

  18. Geographical distribution and time trends of polychlorinated biphenyls in raft mussel from Galician coast (1998-2013).

    PubMed

    Carro, Nieves; García, Isabel; Ignacio, María; Mouteira, Ana

    2015-12-15

    PCBs were analyzed in raft mussels cultured in several polygons from Galician Rías (Rías of Ares-Betanzos, Muros-Noia, Arousa, Pontevedra and Vigo) during the period 1998-2013. The main aim of this work is study the quality of culture marine environment in relation to PCBs compounds. We report the results of a monitoring. The mean levels of ΣPCBs (ten congeners) ranged from 7.41 to 59.50ngg(-1)dw. The isomer concentrations in the Mytilus galloprovincialis cultured in raft were in the order hexachlorobiphenyls>pentachlorobiphenyls>tetrachlorbiphenyls>trichlorobiphenyls. Some biological parameters of mussel were also investigated (shell length, lipid content and condition index) in order to know their influence on ability of PCBs accumulation. ANOVA analysis confirms that levels of most of congeners had a significant relation (p<0.05) with shell length. The geographical patterns and temporal variations of PCBs were also investigated. Principal Component Analysis (PCA) showed differences between geographic areas (Rías) in the distribution of PCBs levels. Samples coming from Rías of Vigo and Ares-Betanzos presented the highest levels of PCBs and samples from Rías of Arousa and Muros-Noia had the lowest levels of these compounds. Time trends (linear regressions) showed a decline of levels of PCB congeners along the period 1998-2013. PMID:26318808

  19. Geographic distribution and habitat diversity of the Barbary Macaque sylvanus L.

    PubMed

    Taub, D M

    1977-01-01

    During a 15-month behavioral study in Morocco and a 3-month survey in Morocco and Algeria, the present distribution of the Barbary macaque was determined. In Algeria, monkeys are found in seven constricted and disjunct localities in the Grande and Petite Kabylie mountain ranges. These localities are severely restricted in space and are located in remote or inaccessible areas which support only small populations. Their habitats include mixed cedar and holm oak forests, humid Portuguese and cork oak mixes and gorges dominated by scrub vegetation. In only two regions (Guerrouch and Agfadou) can population of reasonable size be found; even there they do not approach the abundance found in the central Middle Atlas zone of Morocco. Distribution was more extensive earlier in this century and some areas have become unoccupied within the past 15 years. Today, their absolute numbers and population densities are low in all but two locations. Algeria contains approximately 23% (5,500 maximum) of the total number of surviving Barbary macaques in North Africa. About 77% of the total number of Barbary macaques occur in Morocco. Moroccan habitats include high cedar forests, cedar/holm-oak mixtures and pure holm oak forests. Macaque distribution in the High Atlas is restricted to the Ourika valley where only a small relict population survives. There are between five and eight small, disjunct forest pockets in the Rif which support small groups of monkeys. In the Middle Atlas, monkeys are found in high numbers and in relatively wide stretches of distribution, although there are constricted areas of low densities in this region also. 65% (14,000 maximum) of the animals and their highest densities occur in the high mixed cedar forests of the Central zone, and mixed cedar forest appears to be the preferred habitat for the species. With the exception of the Central zone, their remaining distribution is typically disjunct and constricted, and population densities aer low. As in Algeria

  20. New Data on the Geographical Distribution and Host Utilization of the Entomopathogenic Fungus Myrmicinosporidium durum

    PubMed Central

    Csősz, Sándor; Lapeva-Gjonova, Albena; Markó, Bálint

    2012-01-01

    Entomopathogenic Myrmicinosporidium durum Hölldobler, 1933, a fungus known to exploit several ant species, is reported for the first time in five countries: Bulgaria, the Czech Republic, Romania, Slovakia, and Turkey. The discovery of the fungus in Anatolia significantly widens its known distribution. In addition, this fungal parasite was found to utilize two hitherto unknown host species: Tetramorium sp. D (sensu Schlick-Steiner et al. 2006) and Tetramorium sp. E (sensu Schlick-Steiner et al. 2006). According to the new data, M. durum seems to be more common in Europe than previously thought, while its host range is considerably larger. In the present paper, data on its currently known distribution and host preference are discussed. PMID:23448195

  1. Issues in ATM Support of High-Performance, Geographically Distributed Computing

    NASA Technical Reports Server (NTRS)

    Claus, Russell W.; Dowd, Patrick W.; Srinidhi, Saragur M.; Blade, Eric D.G

    1995-01-01

    This report experimentally assesses the effect of the underlying network in a cluster-based computing environment. The assessment is quantified by application-level benchmarking, process-level communication, and network file input/output. Two testbeds were considered, one small cluster of Sun workstations and another large cluster composed of 32 high-end IBM RS/6000 platforms. The clusters had Ethernet, fiber distributed data interface (FDDI), Fibre Channel, and asynchronous transfer mode (ATM) network interface cards installed, providing the same processors and operating system for the entire suite of experiments. The primary goal of this report is to assess the suitability of an ATM-based, local-area network to support interprocess communication and remote file input/output systems for distributed computing.

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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. Results 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 < 0.0001). Both the 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. Conclusion 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

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

    PubMed Central

    2012-01-01

    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. PMID:23170899

  4. Geographical distribution of the Aedes Triseriatus Group (Diptera: Culicidae) in Mexico.

    PubMed

    Sánchez-Trinidad, Adelfo; Ordoñez-Sánchez, Félix; Valdes-Perezgasga, Ma Teresa; Sánchez-Ramos, Francisco J; Zavortink, Thomas J; Cortés-Guzmán, Antonio J; Ortega-Morales, Aldo I

    2014-06-01

    Aedes brelandi Zavortink is reported for the first time outside of the United States, where it has been found in northern and central parts of Mexico. Ae. triseriatus (Say) is reported in northern and central Mexico and Ae. zoosophus Dyar and Knab is recorded in southern Mexico. Collection records for these species in northern, central, and southern Mexico showing the current distribution of the Aedes Triseriatus Group are included. PMID:24820565

  5. Improved Predictions of the Geographic Distribution of Invasive Plants Using Climatic Niche Models.

    PubMed

    Ramírez-Albores, Jorge E; Bustamante, Ramiro O; Badano, Ernesto I

    2016-01-01

    Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of

  6. Improved Predictions of the Geographic Distribution of Invasive Plants Using Climatic Niche Models

    PubMed Central

    Ramírez-Albores, Jorge E.; Bustamante, Ramiro O.

    2016-01-01

    Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of

  7. The geographic distribution and complex evolutionary history of the NX-2 trichothecene chemotype from Fusarium graminearum.

    PubMed

    Kelly, Amy; Proctor, Robert H; Belzile, Francois; Chulze, Sofia N; Clear, Randall M; Cowger, Christina; Elmer, Wade; Lee, Theresa; Obanor, Friday; Waalwijk, Cees; Ward, Todd J

    2016-10-01

    Fusarium graminearum and 21 related species comprising the F. sambucinum species complex lineage 1 (FSAMSC-1) are the most important Fusarium Head Blight pathogens of cereal crops world-wide. FSAMSC-1 species typically produce type B trichothecenes. However, some F. graminearum strains were recently found to produce a novel type A trichothecene (NX-2) resulting from functional variation in the trichothecene biosynthetic enzyme Tri1. We used a PCR-RFLP assay targeting the TRI1 gene to identify the NX-2 allele among a global collection of 2515 F. graminearum. NX-2 isolates were only found in southern Canada and the northern U.S., where they were observed at low frequency (1.8%), but over a broader geographic range and set of cereal hosts than previously recognized. Phylogenetic analyses of TRI1 and adjacent genes produced gene trees that were incongruent with the history of species divergence within FSAMSC-1, indicating trans-species evolution of ancestral polymorphism. In addition, placement of NX-2 strains in the TRI1 gene tree was influenced by the accumulation of nonsynonymous substitutions associated with the evolution of the NX-2 chemotype, and a significant (P<0.001) change in selection pressure was observed along the NX-2 branch (ω=1.16) in comparison to other branches (ω=0.17) in the TRI1 phylogeny. Parameter estimates were consistent with positive selection for specific amino-acid changes during the evolution of NX-2, but direct tests of positive selection were not significant. Phylogenetic analyses of fourfold degenerate sites and intron sequences in TRI1 indicated the NX-2 chemotype had a single evolutionary origin and evolved recently from a type B ancestor. Our results indicate the NX-2 chemotype may be indigenous, and possibly endemic, to southern Canada and the northern U.S. In addition, we demonstrate that the evolution of TRI1 within FSAMSC-1 has been complex, with evidence of trans-species evolution and chemotype-specific shifts in selective

  8. Assessing the Groundwater Concentrations and Geographical Distribution of Arsenic in Nepal

    NASA Astrophysics Data System (ADS)

    Ma, J.; Liu, F.

    2015-12-01

    understanding of the correlations, we can predict whether an area is suffering from arsenic laden groundwater without actual field testing. We use R and ArcGIS to conduct the statistical and geographical analysis in this project.

  9. Geographic asymmetries of the Viking auroral distribution: Implications for ionospheric coordinate systems

    SciTech Connect

    Hearn, D.J.; Elphinstone, R.D.; Murphree, J.S.; Cogger, L.L. )

    1993-02-01

    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.

  10. Does Day Length Affect Winter Bird Distribution? Testing the Role of an Elusive Variable

    PubMed Central

    Carrascal, Luis M.; Santos, Tomás; Tellería, José L.

    2012-01-01

    Differences in day length may act as a critical factor in bird biology by introducing time constraints in energy acquisition during winter. Thus, differences in day length might operate as a main determinant of bird abundance along latitudinal gradients. This work examines the influence of day length on the abundance of wintering crested tits (Lophophanes cristatus) in 26 localities of Spanish juniper (Juniperus thurifera) dwarf woodlands (average height of 5 m) located along a latitudinal gradient in the Spanish highlands, while controlling for the influence of food availability, minimum night temperature, habitat structure and landscape characteristics. Top regression models in the AIC framework explained 56% of variance in bird numbers. All models incorporated day length as the variable with the highest magnitude effect. Food availability also played an important role, although only the crop of ripe juniper fruits, but not arthropods, positively affected crested tit abundance. Differences in vegetation structure across localities had also a strong positive effect (average tree height and juniper tree density). Geographical variation in night temperature had no influence on crested tit distribution, despite the low winter temperatures reached in these dwarf forests. This paper demonstrates for the first time that winter bird abundance increases with day length after controlling for the effect of other environmental variables. Winter average difference in day length was only 10.5 minutes per day along the 1°47′ latitudinal interval (190 km) included in this study. This amount of time, which reaches 13.5 h accumulated throughout the winter season, appears to be large enough to affect the long-term energy budget of small passerines during winter and to shape the distribution of winter bird abundance under restrictive environmental conditions. PMID:22393442

  11. Aspects of Benthic Decapod Diversity and Distribution from Rocky Nearshore Habitat at Geographically Widely Dispersed Sites

    PubMed Central

    Pohle, Gerhard; Iken, Katrin; Clarke, K. Robert; Trott, Thomas; Konar, Brenda; Cruz-Motta, Juan José; Wong, Melisa; Benedetti-Cecchi, Lisandro; Mead, Angela; Miloslavich, Patricia; Mieszkowska, Nova; Milne, Rebecca; Tamburello, Laura; Knowlton, Ann; Kimani, Edward; Shirayama, Yoshihisa

    2011-01-01

    Relationships of diversity, distribution and abundance of benthic decapods in intertidal and shallow subtidal waters to 10 m depth are explored based on data obtained using a standardized protocol of globally-distributed samples. Results indicate that decapod species richness overall is low within the nearshore, typically ranging from one to six taxa per site (mean = 4.5). Regionally the Gulf of Alaska decapod crustacean community structure was distinguishable by depth, multivariate analysis indicating increasing change with depth, where assemblages of the high and mid tide, low tide and 1 m, and 5 and 10 m strata formed three distinct groups. Univariate analysis showed species richness increasing from the high intertidal zone to 1 m subtidally, with distinct depth preferences among the 23 species. A similar depth trend but with peak richness at 5 m was observed when all global data were combined. Analysis of latitudinal trends, confined by data limitations, was equivocal on a global scale. While significant latitudinal differences existed in community structure among ecoregions, a semi-linear trend in changing community structure from the Arctic to lower latitudes did not hold when including tropical results. Among boreal regions the Canadian Atlantic was relatively species poor compared to the Gulf of Alaska, whereas the Caribbean and Sea of Japan appeared to be species hot spots. While species poor, samples from the Canadian Atlantic were the most diverse at the higher infraordinal level. Linking 11 environmental variables available for all sites to the best fit family-based biotic pattern showed a significant relationship, with the single best explanatory variable being the level of organic pollution and the best combination overall being organic pollution and primary productivity. While data limitations restrict conclusions in a global context, results are seen as a first-cut contribution useful in generating discussion and more in-depth work in the still

  12. A Review of the Geographical Distribution and Habitat of the Atlantic Humpback Dolphin (Sousa teuszii).

    PubMed

    Weir, Caroline R; Collins, Tim

    2015-01-01

    Understanding of the distributional ecology of the Atlantic humpback dolphin (Sousa teuszii) has been hampered by a lack of systematic and consistent sampling effort. The only comprehensive species distribution review was published in 2004; since then a considerable amount of novel information has emerged. We compiled 853 sighting, capture and specimen records of the species, and produced global and regional distribution maps. Of the 830 records where year was available, 63.1% dated from ≥2005 and confirm a contemporary occurrence in six marine ecoregions and 11 countries: Western Sahara, Mauritania, Senegal, Gambia, Guinea-Bissau, Guinea, Benin, Cameroon, Gabon, Congo Republic and Angola. Additionally, Togo is a recently confirmed range state. Group sizes ranged from 1 to 45 animals, with small groups of 1 to 10 animals comprising 65% of the sightings. Similarities were noted in the regions inhabited by Atlantic humpback dolphins across their range, particularly an occurrence in relatively shallow (predominantly ≤20 m) depths, in warm waters (average SSTs of 15.8-31.8°C) and in dynamic habitat strongly influenced by tidal patterns. These conditions occur in various habitats occupied by the species, including estuarine systems, open coasts, archipelagos, tidal mud-flats and sheltered bays. Sightings were recorded at distances of 13 m to 12.8 km (mean of 573 m) from land, indicating that the species occurs several kilometres from shore when suitable shallow habitat is present. The Atlantic humpback dolphin may be a 'nearshore' species based on oceanographic definitions incorporating water depth, wave action and sedimentation rather than on spatial distance from the coast. PMID:26555623

  13. Aspects of benthic decapod diversity and distribution from rocky nearshore habitat at geographically widely dispersed sites.

    PubMed

    Pohle, Gerhard; Iken, Katrin; Clarke, K Robert; Trott, Thomas; Konar, Brenda; Cruz-Motta, Juan José; Wong, Melisa; Benedetti-Cecchi, Lisandro; Mead, Angela; Miloslavich, Patricia; Mieszkowska, Nova; Milne, Rebecca; Tamburello, Laura; Knowlton, Ann; Kimani, Edward; Shirayama, Yoshihisa

    2011-01-01

    Relationships of diversity, distribution and abundance of benthic decapods in intertidal and shallow subtidal waters to 10 m depth are explored based on data obtained using a standardized protocol of globally-distributed samples. Results indicate that decapod species richness overall is low within the nearshore, typically ranging from one to six taxa per site (mean = 4.5). Regionally the Gulf of Alaska decapod crustacean community structure was distinguishable by depth, multivariate analysis indicating increasing change with depth, where assemblages of the high and mid tide, low tide and 1 m, and 5 and 10 m strata formed three distinct groups. Univariate analysis showed species richness increasing from the high intertidal zone to 1 m subtidally, with distinct depth preferences among the 23 species. A similar depth trend but with peak richness at 5 m was observed when all global data were combined. Analysis of latitudinal trends, confined by data limitations, was equivocal on a global scale. While significant latitudinal differences existed in community structure among ecoregions, a semi-linear trend in changing community structure from the Arctic to lower latitudes did not hold when including tropical results. Among boreal regions the Canadian Atlantic was relatively species poor compared to the Gulf of Alaska, whereas the Caribbean and Sea of Japan appeared to be species hot spots. While species poor, samples from the Canadian Atlantic were the most diverse at the higher infraordinal level. Linking 11 environmental variables available for all sites to the best fit family-based biotic pattern showed a significant relationship, with the single best explanatory variable being the level of organic pollution and the best combination overall being organic pollution and primary productivity. While data limitations restrict conclusions in a global context, results are seen as a first-cut contribution useful in generating discussion and more in-depth work in the still

  14. Edible Lepidoptera in Mexico: Geographic distribution, ethnicity, economic and nutritional importance for rural people

    PubMed Central

    2011-01-01

    In this paper, we reported the butterflies and moths that are consumed in Mexico. We identified 67 species of Lepidoptera that are eaten principally in their larval stage in 17 states of Mexico. These species belong to 16 families: Arctiidae, Bombycidae, Castniidae, Cossidae, Geometridae, Hepialidae, Hesperiidae, Lasiocampidae, Noctuidae, Nymphalidae, Papilionidae, Pieridae, Pyralidae, Saturniidae, Sesiidae, and Sphingidae. Saturniidae, Pieridae, Noctuidae and Nymphalidae were the more species consumed with 16, 11, 9, and 8 species, respectively. The genera with the largest numbers of species were: Phassus, Phoebis, Hylesia and Spodoptera, with three species. Their local distribution, corresponding to each state of Mexico, is also presented. PMID:21211040

  15. Edible Lepidoptera in Mexico: Geographic distribution, ethnicity, economic and nutritional importance for rural people.

    PubMed

    Ramos-Elorduy, Julieta; Moreno, José M P; Vázquez, Adolfo I; Landero, Ivonne; Oliva-Rivera, Héctor; Camacho, Víctor H M

    2011-01-01

    In this paper, we reported the butterflies and moths that are consumed in Mexico. We identified 67 species of Lepidoptera that are eaten principally in their larval stage in 17 states of Mexico. These species belong to 16 families: Arctiidae, Bombycidae, Castniidae, Cossidae, Geometridae, Hepialidae, Hesperiidae, Lasiocampidae, Noctuidae, Nymphalidae, Papilionidae, Pieridae, Pyralidae, Saturniidae, Sesiidae, and Sphingidae.Saturniidae, Pieridae, Noctuidae and Nymphalidae were the more species consumed with 16, 11, 9, and 8 species, respectively. The genera with the largest numbers of species were: Phassus, Phoebis, Hylesia and Spodoptera, with three species.Their local distribution, corresponding to each state of Mexico, is also presented. PMID:21211040

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

    PubMed

    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. PMID:25018008

  17. Geographical distribution of vectors and sero-strains of tsutsugamushi disease at mid-south inland of Korea.

    PubMed

    Ree, H I; Lee, I Y; Jeon, S H; Yoshida, Y

    1997-09-01

    Studies of geographical distributions and relative population densities of the vector mites of tsutsugamushi disease were carried out in October 1996 at 12 locations of the mid-south inland of the Korean peninsula, where chigger mites have been never studied. Of 177 field rodents and insectivores collected, 154 (87.0%) were Apodemus agrarius. Total 25,707 chigger mites were collected and 14 species were identified, of which Leptotrombidium pallidum was predominant (79.8%) and L. palpale the next (8.9%). L. pallidum, the vector species, was widely distributed in all study areas, showing the highest density at Cho-o 2-dong, Sangju-si (chigger index 201.8), and the lowest at Tanwol-dong. Chungju-si (chigger index 40.7). The other vector species, L. scutellare was found only at the southern part of the study area such as Yobae and Mipyong, Kumrunggun and Unsu, Kimchon-si. The northernmost areas of the L. scutellare distribution were coincided with the areas where anual mean air temperature is above 10.0 C. Among 157 A. agrarius sera tested, 48.3% was Karp, 1.7% Gilliam and 3.3% Kuroki. The rest of the sera were not able to determine the sero-type because of the cross antigen-antibody reactions among the tested sero-types. PMID:9335182

  18. Geostatistics and Geographic Information Systems to Study the Spatial Distribution of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in Peach Fields.

    PubMed

    Duarte, F; Calvo, M V; Borges, A; Scatoni, I B

    2015-08-01

    The oriental fruit moth, Grapholita molesta (Busck), is the most serious pest in peach, and several insecticide applications are required to reduce crop damage to acceptable levels. Geostatistics and Geographic Information Systems (GIS) are employed to measure the range of spatial correlation of G. molesta in order to define the optimum sampling distance for performing spatial analysis and to determine the current distribution of the pest in peach orchards of southern Uruguay. From 2007 to 2010, 135 pheromone traps per season were installed and georeferenced in peach orchards distributed over 50,000 ha. Male adult captures were recorded weekly from September to April. Structural analysis of the captures was performed, yielding 14 semivariograms for the accumulated captures analyzed by generation and growing season. Two sets of maps were constructed to describe the pest distribution. Nine significant models were obtained in the 14 evaluated periods. The range estimated for the correlation was from 908 to 6884 m. Three hot spots of high population level and some areas with comparatively low populations were constant over the 3-year period, while there is a greater variation in the size of the population in different generations and years in other areas. PMID:26174957

  19. Geographical distribution and prevalence of Borrelia burgdorferi genospecies in questing Ixodes ricinus from Romania: a countrywide study.

    PubMed

    Kalmár, Zsuzsa; Mihalca, Andrei D; Dumitrache, Mirabela O; Gherman, Călin M; Magdaş, Cristian; Mircean, Viorica; Oltean, Miruna; Domşa, Cristian; Matei, Ioana A; Mărcuţan, Daniel I; Sándor, Attila D; D'Amico, Gianluca; Paştiu, Anamaria; Györke, Adriana; Gavrea, Raluca; Marosi, Béla; Ionică, Angela; Burkhardt, Etelka; Toriay, Hortenzia; Cozma, Vasile

    2013-09-01

    The paper reports the prevalence and geographical distribution of Borrelia burgdorferi sensu lato (s.l.) and its genospecies in 12,221 questing Ixodes ricinus ticks collected at 183 locations from all the 41 counties of Romania. The unfed ticks were examined for the presence of B. burgdorferi s.l. by PCR targeting the intergenic spacer 5S-23S. Reverse line blot hybridization (RLB) and restriction fragment length polymorphism (RFLP) analysis were performed for identification of B. burgdorferi genospecies. The overall prevalence of infection was 1.4%, with an average local prevalence between 0.75% and 18.8%. B. burgdorferi s.l. was found in ticks of 55 of the 183 localities. The overall prevalence B. burgdorferi s.l. in ticks in the infected localities was 3.8%. The total infection prevalence was higher in female ticks than in other developmental stages. Three Borrelia genospecies were detected. The most widely distributed genospecies was B. afzelii, followed by B. garinii and B. burgdorferi sensu stricto (s.s.). The study is the first countrywide study and the first report of B. burgdorferi s.s. in Romania. The distribution maps show that higher prevalences were recorded in hilly areas, but Lyme borreliosis spirochetes were also present in forested lowlands, albeit with a lower prevalence. PMID:23890805

  20. Tidal influence on O(1S) airglow emission rate distributions at the geographic equator as observed by WINDII

    NASA Technical Reports Server (NTRS)

    Shephere, G. G.; Mclandress, C.; Solheim, B. H.

    1995-01-01

    WINDII, the Wind Imaging Interferometer on the Upper Atmosphere Research Satellite, observes winds, temperatures and emission rates in the upper mesosphere and thermosphere. In this paper we report on nighttime observations of the vertical distribution of the O(1S) 557.7 nm emission near the geographic equator for March/April, 1993. The airglow volume emission rate distribution is found to be strongly dependent on local time. Beginning at dusk, an intense airglow emission layer descends from a mean altitude of 95 km, reaching 89 km by midnight after which the emission rapidly decays. Shortly after midnight it reappears weakly at a higher altitude and remains at this level as the emission rate gradually increases towards dawn. This strong local time dependence leads us to conclude that the effect is tidally driven. Comparison with the Forbes (1982a,b) model suggest that total density perturbations and changes in the atomic oxygen mixing ratio may the cause of the changes in emission rate distribution between dusk and midnight. The reappearance of the emission after midnight may be caused by downward winds bringing oxygen-rich air from above.

  1. Assessing the status and trend of bat populations across broad geographic regions with dynamic distribution models

    USGS Publications Warehouse

    Rodhouse, Thomas J.; Ormsbee, Patricia C.; Irvine, Kathryn M.; Vierling, Lee A.; Szewczak, Joseph M.; Vierling, Kerri T.

    2012-01-01

    Despite its common status, M. lucifugus was only detected during ∼50% of the surveys in occupied sample units. The overall naïve estimate for the proportion of the study region occupied by the species was 0.69, but after accounting for imperfect detection, this increased to ∼0.90. Our models provide evidence of an association between NPP and forest cover and M. lucifugus distribution, with implications for the projected effects of accelerated climate change in the region, which include net aridification as snowpack and stream flows decline. Annual turnover, the probability that an occupied sample unit was a newly occupied one, was estimated to be low (∼0.04–0.14), resulting in flat trend estimated with relatively high precision (SD = 0.04). We mapped the variation in predicted occurrence probabilities and corresponding prediction uncertainty along the productivity gradient. Our results provide a much needed baseline against which future anticipated declines in M. lucifugus occurrence can be measured. The dynamic distribution modeling approach has broad applicability to regional bat monitoring efforts now underway in several countries and we suggest ways to improve and expand our grid-based monitoring program to gain robust insights into bat population status and trend across large portions of North America.

  2. Geographic distribution, evolution, and disease importance of species within the Neotropical Anopheles albitarsis Group (Diptera, Culicidae)

    PubMed Central

    Linton, Yvonne-Marie; Ruiz-Lopez, J. Freddy; Conn, Jan E.; Sallum, Maria Anice M.; Póvoa, Marinete M.; Bergo, Eduardo S.; Oliveira, Tatiane M. P.; Sucupira, Izis; Wilkerson, Richard C.

    2015-01-01

    The Anopheles albitarsis group of mosquitoes comprises eight recognized species and one mitochondrial lineage. Our knowledge of malaria vectorial importance and the distribution and evolution of these taxa is incomplete. We constructed ecological niche models (ENMs) for these taxa and used hypothesized phylogenetic relationships and ENMs to investigate environmental and ecological divergence associated with speciation events. Two major clades were identified, one north (Clade 1) and one south (Clade 2) of the Amazon River that likely is or was a barrier to mosquito movement. Clade 1 species occur more often in higher average temperature locations than Clade 2 species, and taxon splits within Clade 1 corresponded with a greater divergence of variables related to precipitation than was the case within Clade 2. Comparison of the ecological profiles of sympatric species and sister species support the idea that phylogenetic proximity is related to ecological similarity. Anopheles albitarsis I, An. janconnae, and An. marajoara ENMs had the highest percentage of their predicted suitable habitat overlapping distribution models of Plasmodium falciparum and P. vivax, and warrant additional studies of the transmission potential of these species. Phylogenetic proximity may be related to malaria vectorial importance within the Albitarsis Group. PMID:24820570

  3. Geographic distribution, evolution, and disease importance of species within the Neotropical Anopheles albitarsis Group (Diptera, Culicidae).

    PubMed

    Foley, Desmond H; Linton, Yvonne-Marie; Ruiz-Lopez, J Freddy; Conn, Jan E; Sallum, Maria Anice M; Póvoa, Marinete M; Bergo, Eduardo S; Oliveira, Tatiane M P; Sucupira, Izis; Wilkerson, Richard C

    2014-06-01

    The Anopheles albitarsis group of mosquitoes comprises eight recognized species and one mitochondrial lineage. Our knowledge of malaria vectorial importance and the distribution and evolution of these taxa is incomplete. We constructed ecological niche models (ENMs) for these taxa and used hypothesized phylogenetic relationships and ENMs to investigate environmental and ecological divergence associated with speciation events. Two major clades were identified, one north (Clade 1) and one south (Clade 2) of the Amazon River that likely is or was a barrier to mosquito movement. Clade 1 species occur more often in higher average temperature locations than Clade 2 species, and taxon splits within Clade 1 corresponded with a greater divergence of variables related to precipitation than was the case within Clade 2. Comparison of the ecological profiles of sympatric species and sister species support the idea that phylogenetic proximity is related to ecological similarity. Anopheles albitarsis I, An. janconnae, and An. marajoara ENMs had the highest percentage of their predicted suitable habitat overlapping distribution models of Plasmodium falciparum and P. vivax, and warrant additional studies of the transmission potential of these species. Phylogenetic proximity may be related to malaria vectorial importance within the Albitarsis Group. PMID:24820570

  4. How required reserve ratio affects distribution and velocity of money

    NASA Astrophysics Data System (ADS)

    Xi, Ning; Ding, Ning; Wang, Yougui

    2005-11-01

    In this paper the dependence of wealth distribution and the velocity of money on the required reserve ratio is examined based on a random transfer model of money and computer simulations. A fractional reserve banking system is introduced to the model where money creation can be achieved by bank loans and the monetary aggregate is determined by the monetary base and the required reserve ratio. It is shown that monetary wealth follows asymmetric Laplace distribution and latency time of money follows exponential distribution. The expression of monetary wealth distribution and that of the velocity of money in terms of the required reserve ratio are presented in a good agreement with simulation results.

  5. Assessing the status and trend of bat populations across broad geographic regions with dynamic distribution models.

    PubMed

    Rodhouse, Thomas J; Ormsbee, Patricia C; Irvine, Kathryn M; Vierling, Lee A; Szewczak, Joseph M; Vierling, Kerri T

    2012-06-01

    Bats face unprecedented threats from habitat loss, climate change, disease, and wind power development, and populations of many species are in decline. A better ability to quantify bat population status and trend is urgently needed in order to develop effective conservation strategies. We used a Bayesian autoregressive approach to develop dynamic distribution models for Myotis lucifugus, the little brown bat, across a large portion of northwestern USA, using a four-year detection history matrix obtained from a regional monitoring program. This widespread and abundant species has experienced precipitous local population declines in northeastern USA resulting from the novel disease white-nose syndrome, and is facing likely range-wide declines. Our models were temporally dynamic and accounted for imperfect detection. Drawing on species-energy theory, we included measures of net primary productivity (NPP) and forest cover in models, predicting that M. lucifugus occurrence probabilities would covary positively along those gradients. Despite its common status, M. lucifugus was only detected during -50% of the surveys in occupied sample units. The overall naive estimate for the proportion of the study region occupied by the species was 0.69, but after accounting for imperfect detection, this increased to -0.90. Our models provide evidence of an association between NPP and forest cover and M. lucifugus distribution, with implications for the projected effects of accelerated climate change in the region, which include net aridification as snowpack and stream flows decline. Annual turnover, the probability that an occupied sample unit was a newly occupied one, was estimated to be low (-0.04-0.14), resulting in flat trend estimated with relatively high precision (SD = 0.04). We mapped the variation in predicted occurrence probabilities and corresponding prediction uncertainty along the productivity gradient. Our results provide a much needed baseline against which future

  6. Dietary flexibility of the brown howler monkey throughout its geographic distribution.

    PubMed

    Chaves, Oscar M; César Bicca-Marques, Júlio

    2013-01-01

    Habitat loss and fragmentation constrain the survival of most forest-living mammals, particularly strictly arboreal primates. Because fragment size directly affects food availability, primate survival in small fragments may depend on dietary flexibility. Here, we review the literature on the diet of 29 wild groups of Alouatta guariba clamitans inhabiting forest fragments in Brazil and Argentina. We identify general feeding patterns and analyze the influence of fragment size and latitude on diet composition. Brown howlers presented a diet composed of 402 plant species belonging to 227 genera and 80 families. Rarefaction curves suggest that the richness of top food species is similar among groups living in larger (>100 ha), medium (11-100 ha) or small (1-10 ha) fragments. On average, only 12% of the plant species used as food sources by a given group was also consumed by groups from other sites. The shorter the distance between sites, the higher the diet similarity among groups. Despite their diet flexibility, brown howlers spent >80% of the total feeding records on 6-24 species belonging to genera such as Ficus, Zanthoxylum, and Eugenia. Leaves and fruits were the plant items most consumed (65% and 22% of the total feeding records, respectively). Leaf consumption was not affected by fragment size, but it was inversely related to latitude, which may be linked to an increase in the concentration of secondary metabolites in leaves at higher latitudes. We suggest that the ability of brown howlers to exploit a large number of plant food species, including native and exotic trees, shrubs, vines, and lianas, is an important trait that contributes to their survival in highly fragmented habitats along the Atlantic forest. Similar meta-analyses of data from other howler species are necessary to test whether such dietary flexibility is a genus-wide pattern. PMID:22972605

  7. The geographical distribution of lightning: Forestry and range requirements and interests

    NASA Technical Reports Server (NTRS)

    Vance, D. L.

    1979-01-01

    In an attempt to reduce the response time of the initial attack forces to lightning-caused fire, a lightning detection system that effectively locates accurate directions to lightning discharges to over 200 miles from the detection equipment was developed. The system was first tested in Alaska in 1975. Since that time, further development and operational testing led to the implementation of wide area networks. For the 1979 fire season an eight station network in Alaska is to be implemented that will cover virtually all of the lightning-caused fire areas in the state. In the western United States, an eighteen station network that will cover approximately 85% of eleven states is to be implemented. For the first time, large scale ground discharge lightning distribution information is to be available.

  8. Geographic patterns in the distribution of social systems in terrestrial arthropods.

    PubMed

    Purcell, Jessica

    2011-05-01

    The role of ecology in the evolution and maintenance of arthropod sociality has received increasing research attention in recent years. In some organisms, such as halictine bees, polistine wasps, and social spiders, researchers are investigating the environmental factors that may contribute to high levels of variation in the degree of sociality exhibited both among and within species. Within lineages that include only eusocial members, such as ants and termites, studies focus more on identifying extrinsic factors that may contribute to the dramatic variation in colony size, number of queens, and division of labour that is evident across these species. In this review, I propose a comparative approach that seeks to identify environmental factors that may have a common influence across such divergent social arthropod groups. I suggest that seeking common biogeographic patterns in the distribution of social systems or key social traits may help us to identify ecological factors that play a common role in shaping the evolution of sociality across different organisms. I first review previous studies of social gradients that form along latitudinal and altitudinal axes. Within families and within species, many organisms show an increasing degree of sociality at lower latitudes and altitudes. In a smaller number of cases, organisms form larger groups or found nests cooperatively at higher latitudes and altitudes. I then describe several environmental factors that vary consistently along such gradients, including climate variables and abundance of predators, and outline their proposed role in the social systems of terrestrial arthropods. Finally, I map distributions of a social trait against several climatic factors in five case studies to demonstrate how future comparative studies could inform empirical research. PMID:20840372

  9. Predicting habitat suitability and geographic distribution of anchovy (Engraulis ringens) due to climate change in the coastal areas off Chile

    NASA Astrophysics Data System (ADS)

    Silva, Claudio; Andrade, Isabel; Yáñez, Eleuterio; Hormazabal, Samuel; Barbieri, María Ángela; Aranis, Antonio; Böhm, Gabriela

    2016-08-01

    results of this work show that the model has produced robust estimates of habitat suitability and geographic distribution off Chile and has been especially effective in capturing the spatial and temporal variability of CPUE. Using IDRISI geographical information system (GIS), these HSI models simulated monthly changes in the habitat suitability (i.e., relative abundance) and distribution of anchovy off Chile forced by changes in the regionalised SST and Chl-a as projected by the NCAR model under the A2 emission scenario. The simulations predicted a moderate negative change of 17% and 13% for the north and central-south areas, respectively, in the habitat suitability (i.e., potential relative abundance) of anchovy by 2055.

  10. Infant Sensitivity to Distributional Information Can Affect Phonetic Discrimination.

    ERIC Educational Resources Information Center

    Maye, Jessica; Werker, Janet F.; Gerken, LouAnn

    2002-01-01

    Familiarized 6- and 8-month-olds with speech sounds from a phonetic continuum, exhibiting a bimodal or unimodal frequency distribution. Found that only infants in the bimodal condition discriminated tokens from the endpoints of the continuum. Results demonstrate that infants are sensitive to the statistical distribution of speech sounds in the…

  11. Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution

    PubMed Central

    2012-01-01

    Background Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Methods Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant. Results We examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus. Conclusions Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most

  12. Geographic Distribution of Natural Products Produced by the Red Alga Laurencia dendroidea J. Agardh.

    PubMed

    Machado, Fernanda L S; Duarte, Heitor M; Gestinari, Lísia M S; Cassano, Valéria; Kaiser, Carlos R; Soares, Angélica R

    2016-07-01

    In order to evaluate the chemical diversity of Laurencia dendroidea J. Agardh, a widely distributed seaweed in Brazilian coast, a phytochemical study was carried out with algae collected from six different locations along the Southeast Brazilian coast. Purified compounds were identified by MS and NMR techniques. The chemical profiles of lipophilic extracts were obtained by GC/MS for each population. In total, 15 compounds were described. The sesquiterpene composition accounted for 49 - 63% of the GC/MS chromatogram area. The discrimination of three chemotypes was done by the use of HCA on GC/MS chromatograms. They were also analyzed by the PCA and, together with peak area analysis, it was possible to discriminate all populations by the main variation of elatol, obtusol, rogiolol, and triquinane. The results revealed the high diversity of sesquiterpene composition among populations of L. dendroidea. Curiously, the within and among population variation of elatol and obtusol suggested a biochemical interplay on the content of these compounds. More studies are necessary to understand the patterns of chemical diversity and compound variation within and among populations of L. dendroidea. PMID:27224289

  13. Geographic Distribution of Archaeal Ammonia Oxidizing Ecotypes in the Atlantic Ocean

    PubMed Central

    Sintes, Eva; De Corte, Daniele; Haberleitner, Elisabeth; Herndl, Gerhard J.

    2016-01-01

    In marine ecosystems, Thaumarchaeota are most likely the major ammonia oxidizers. While ammonia concentrations vary by about two orders of magnitude in the oceanic water column, archaeal ammonia oxidizers (AOA) vary by only one order of magnitude from surface to bathypelagic waters. Thus, the question arises whether the key enzyme responsible for ammonia oxidation, ammonia monooxygenase (amo), exhibits different affinities to ammonia along the oceanic water column and consequently, whether there are different ecotypes of AOA present in the oceanic water column. We determined the abundance and phylogeny of AOA based on their amoA gene. Two ecotypes of AOA exhibited a distribution pattern reflecting the reported availability of ammonia and the physico-chemical conditions throughout the Atlantic, and from epi- to bathypelagic waters. The distinction between these two ecotypes was not only detectable at the nucleotide level. Consistent changes were also detected at the amino acid level. These changes include substitutions of polar to hydrophobic amino acid, and glycine substitutions that could have an effect on the configuration of the amo protein and thus, on its activity. Although we cannot identify the specific effect, the ratio of non-synonymous to synonymous substitutions (dN/dS) between the two ecotypes indicates a strong positive selection between them. Consequently, our results point to a certain degree of environmental selection on these two ecotypes that have led to their niche specialization. PMID:26903961

  14. Taxonomy, diversity, temporal and geographical distribution of Cutaneous Leishmaniasis in Colombia: A retrospective study

    PubMed Central

    Ramírez, Juan David; Hernández, Carolina; León, Cielo M.; Ayala, Martha S.; Flórez, Carolina; González, Camila

    2016-01-01

    Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems. Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes. A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2). This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology. PMID:27328969

  15. Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela.

    PubMed

    Vásquez, Carlos; de Moraes, Gilberto J

    2013-05-01

    The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region. PMID:23065034

  16. Local Biogeopysical Climate Effects Largely Independent of Geographical Land Cover Change Distribution

    NASA Astrophysics Data System (ADS)

    Winckler, Johannes; Reick, Christian; Pongratz, Julia

    2016-04-01

    Land cover change (LCC) happens locally. However, in almost all simulation studies assessing biogeophysical climate effects of LCC, local effects (due to alterations in a model grid box) are mingled with non-local effects (due to alteration in wide-ranging climate circulation). This study presents a method to separate local and non-local effects. The presented method is applicable to any land surface process that is acting locally but capable of influencing wide-ranging climate when applied on a larger scale. Concerning LCC, this method is more widely applicable than methods used in earlier studies, and it derives local and non-local effects from the same pair of simulations. The study illustrates the possibility of validating simulated local effects by comparison to observations on a global scale, and contrasts the underlying mechanisms of local and non-local effects. The simulation results show that local effects within a grid box are largely independent of the worldwide distribution of LCC. Accordingly, by the identification of local effects, an essential part of the climate consequences of LCC can be studied independently of the considered LCC scenarios, which differ strongly in climate modelling studies.

  17. Geographical distribution of organochlorine contaminants and reproductive parameters in Herring Gulls on Lake Superior in 1983.

    PubMed

    Chip Weseloh, D V; Ewins, P J; Struger, J; Mineau, P; Norstrom, R J

    1994-02-01

    As part of the Great Lakes International Surveillance Plan, 1978-83, egg contaminant levels and reproductive output were determined for Herring Gull colonies on Lake Superior in 1983. Since 1974, the Herring Gull has been widely used in the Great Lakes as a spatial and temporal monitor of organochlorine (OC) contaminant levels and associated biological effects. Most eggs contained a wide range of OCs, the main compounds being DDE, polychlorinated biphenyls (PCBs), dieldrin, heptachlor epoxide, oxychlordane, hexachlorobenzene and mirex. Levels of an additional ten OCs and five polychlorinated dibenzo-p-dioxin (PCDD) congeners were also determined for some sites. Overall, levels varied significantly among colonies, but there was no obvious relationship to spatial distribution of contaminants in sediments or fish species. OC levels in eggs had declined by up to 84% since 1974. Eggshells were only 8% thinner than before the introduction of DDT, and shell thinning was not a cause of breeding failure. Average reproductive output varied from 0.15 to 1.57 young per apparently occupied nest in 1983: at 56% of colonies the value was below that thought necessary to maintain stable populations. The main causes of failure were egg disappearence and cannibalism of chicks. Despite this, the population appeared to have been increasing at about 4% per annum. Reduced availability of forage fish during the early 1980s was the most likely reason for the poor reproductive output in 1983. PMID:24221346

  18. Geographic Distribution of Archaeal Ammonia Oxidizing Ecotypes in the Atlantic Ocean.

    PubMed

    Sintes, Eva; De Corte, Daniele; Haberleitner, Elisabeth; Herndl, Gerhard J

    2016-01-01

    In marine ecosystems, Thaumarchaeota are most likely the major ammonia oxidizers. While ammonia concentrations vary by about two orders of magnitude in the oceanic water column, archaeal ammonia oxidizers (AOA) vary by only one order of magnitude from surface to bathypelagic waters. Thus, the question arises whether the key enzyme responsible for ammonia oxidation, ammonia monooxygenase (amo), exhibits different affinities to ammonia along the oceanic water column and consequently, whether there are different ecotypes of AOA present in the oceanic water column. We determined the abundance and phylogeny of AOA based on their amoA gene. Two ecotypes of AOA exhibited a distribution pattern reflecting the reported availability of ammonia and the physico-chemical conditions throughout the Atlantic, and from epi- to bathypelagic waters. The distinction between these two ecotypes was not only detectable at the nucleotide level. Consistent changes were also detected at the amino acid level. These changes include substitutions of polar to hydrophobic amino acid, and glycine substitutions that could have an effect on the configuration of the amo protein and thus, on its activity. Although we cannot identify the specific effect, the ratio of non-synonymous to synonymous substitutions (dN/dS) between the two ecotypes indicates a strong positive selection between them. Consequently, our results point to a certain degree of environmental selection on these two ecotypes that have led to their niche specialization. PMID:26903961

  19. Four Peroxidase Loci in Red-Fruited Tomato Species: Genetics and Geographic Distribution

    PubMed Central

    Rick, Charles M.; Zobel, Richard W.; Fobes, Jon F.

    1974-01-01

    The banding patterns of certain anodal peroxidase variants of red-fruited tomato species are governed by alleles at four loci—two alleles per locus. Alleles at three loci code for modified enzyme migration patterns and are codominant in heterozygotes; those at the fourth locus code for presence or absence of a band. No evidence of linkage was detected in preliminary tests between four of the six possible combinations of loci. All variant alleles—i.e., those not represented in the standard genotype of Lycopersicon esculentum—exist in the wild L. pimpinellifolium from coastal Peru; all but Prx-3n are also known in L. esculentum from the sympatric region but are rare or absent elsewhere. Between the distributions of alleles of Prx-1 and those of Ge, the gamete-eliminator locus, a significant association exists, which probably does not owe to genetic linkage. The tendency of alleles of Prx loci, as well as those of cm, Ge, h, and Od, to be shared between wild and cultivated taxa in the sympatric region but seldom elsewhere, in addition to published correlated evidence, suggests that the wild alleles tend to substitute in cultivated forms as a result of introgression. In respect to the number of common alleles, cultivated tomatoes more closely resemble the wild L. esculentum var. cerasiforme than L. pimpinellifolium. Images PMID:16592148

  20. Geographic distribution and genetic diversity of the Ehrlichia sp. from Panola Mountain in Amblyomma americanum

    PubMed Central

    Loftis, Amanda D; Mixson, Tonya R; Stromdahl, Ellen Y; Yabsley, Michael J; Garrison, Laurel E; Williamson, Phillip C; Fitak, Robert R; Fuerst, Paul A; Kelly, Daryl J; Blount, Keith W

    2008-01-01

    Background A novel Ehrlichia, closely related to Ehrlichia ruminantium, was recently discovered from Panola Mountain State Park, GA, USA. We conducted a study to determine if this agent was recently introduced into the United States. Methods We developed a sensitive PCR assay based on the conserved gltA (citrate synthase) gene and tested DNA samples extracted from 1964 field-collected and 1835 human-biting Amblyomma americanum from 23 eastern states of the USA. Results The novel agent was detected in 36 ticks collected from 10 states between 1998 and 2006. Infected ticks were collected both from vegetation (n = 14, 0.7%) and from humans (n = 22, 1.2%). Fragments of the conserved gltA gene and the variable map1 gene were sequenced from positive samples. Two distinct clades, with 10.5% nucleic acid divergence over the 730 bp map1 sequence, were identified. Conclusion These data suggest that the Panola Mountain Ehrlichia was not recently introduced to the United States; this agent has an extensive distribution throughout the range of its tick vector, has been present in some locations for several years, and displays genetic variability. Furthermore, people in several states were exposed to this agent through the bite of infected ticks, underscoring the potential public health risk of this emerging ehrlichiosis. PMID:18433500

  1. Hybrid control and data acquisition system for geographically distributed sensors for environmental monitoring

    NASA Astrophysics Data System (ADS)

    Garufi, Fabio; Acernese, Fausto; Boiano, Alfonso; De Rosa, Rosario; Romano, Rocco; Barone, Fabrizio

    2007-10-01

    In this paper we describe the architecture and the performances of a hybrid modular acquisition and control system prototype for environmental monitoring and geophysics. The system, an improvement of a VME-UDP/IP based system we developed for interferometric detectors of gravitational waves, is based on a dual-channel 18-bit low noise ADC, a 16-bit DAC module at 1MHz, and a 20-bit slower ADC necessary for the acquisition of an external calibration signal. The module can be configured as stand-alone or mounted on a motherboard as mezzanine in parallel with other modules. Both the modules and the motherboard can send/receive the configuration and the acquired/correction data for control through a standard EPP parallel port to a standard PC, where the real-time computation is performed. Experimental tests have demonstrated that the distributed control systems implemented with this architecture exihibit a delay time of less than 25 μs on a single channel, that is a sustained sampling frequency of more than 40kHz. The system is now under extensive test in two different experiments: the remote control and data acquisition of a set of seismometers, velocimeters and accelerometers to simulate a geophysics networks of sensors and the remote control of the end mirrors of a suspended Michelson interferometer through electrostatic actuators for interferometric detectors of gravitational waves.

  2. Taxonomy, diversity, temporal and geographical distribution of Cutaneous Leishmaniasis in Colombia: A retrospective study.

    PubMed

    Ramírez, Juan David; Hernández, Carolina; León, Cielo M; Ayala, Martha S; Flórez, Carolina; González, Camila

    2016-01-01

    Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems. Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes. A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2). This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology. PMID:27328969

  3. Selenium concentration in the milk of breast-feeding mothers and its geographic distribution.

    PubMed Central

    Zachara, B A; Pilecki, A

    2000-01-01

    A total of 905 human milk samples collected in all provinces of Poland, between 12 and 75 days of lactation, were analyzed for selenium concentration. The distribution of Se levels in milk between the provinces was narrow and varied from 8.81 to 11.58 ng/mL, with the mean value (+/- SD) of 10.24 +/- 2.82 ng/mL. The regions with lower levels of Se were in the central and eastern part of Poland; the areas with higher values were in the northern, western, and southern parts of Poland. No significant correlations were found between Se levels in milk and the age of lactating mothers or between Se levels and the postpartum period. The calculated daily Se intakes by breast-fed infants varied from 6.46 to 8.50 microg/day, with the mean value of 7.52 microg/day. This amount does not meet the recommended dietary allowances for infants between 0 and 6 months of age. Based on Se levels in human milk, we present a selenium map of Poland. PMID:11102294

  4. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 4 2012-04-01 2012-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  5. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 4 2014-04-01 2014-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  6. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 4 2013-04-01 2013-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  7. Latitude, sunshine, and human lactase phenotype distributions may contribute to geographic patterns of modern disease: the inflammatory bowel disease model.

    PubMed

    Szilagyi, Andrew; Leighton, Henry; Burstein, Barry; Xue, Xiaoqing

    2014-01-01

    Countries with high lactase nonpersistence (LNP) or low lactase persistence (LP) populations have lower rates of some "western" diseases, mimicking the effects of sunshine and latitude. Inflammatory bowel disease (IBD), ie, Crohn's disease and ulcerative colitis, is putatively also influenced by sunshine. Recent availability of worldwide IBD rates and lactase distributions allows more extensive comparisons. The aim of this study was to evaluate the extent to which modern day lactase distributions interact with latitude, sunshine exposure, and IBD rates. National IBD rates, national distributions of LP/LNP, and population-weighted average national annual ultraviolet B exposure were obtained, estimated, or calculated from the literature. Negative binomial analysis was used to assess the relationship between the three parameters and IBD rates. Analyses for 55 countries were grouped in three geographic domains, ie, global, Europe, and non-Europe. In Europe, both latitude and ultraviolet B exposure correlate well with LP/LNP and IBD. In non-Europe, latitude and ultraviolet B exposure correlate weakly with LP/LNP, but the latter retains a more robust correlation with IBD. In univariate analysis, latitude, ultraviolet B exposure, and LP/LNP all had significant relationships with IBD. Multivariate analysis showed that lactase distributions provided the best model of fit for IBD. The model of IBD reveals the evolutionary effects of the human lactase divide, and suggests that latitude, ultraviolet B exposure, and LP/LNP mimic each other because LP/LNP follows latitudinal directions toward the equator. However, on a large scale, lactase patterns also follow lateral polarity. The effects of LP/LNP in disease are likely to involve complex interactions. PMID:24971037

  8. A Geographic Information Systems (GIS)-based analysis of modern South African rodent distributions, habitat use, and environmental tolerances

    PubMed Central

    Campbell, Timothy L; Lewis, Patrick J; Thies, Monte L; Williams, Justin K

    2012-01-01

    Goals of this study were to: (1) develop distributional maps of modern rodent genera throughout the countries of South Africa, Lesotho, and Swaziland by georeferencing museum specimens; (2) assess habitat preferences for genera by cross-referencing locality position with South African vegetation; and (3) identify mean annual precipitation and temperature range where the genera are located. Conterminous South Africa including the countries of Lesotho and Swaziland Digital databases of rodent museum specimens housed in the Ditsong National Museum of Natural History, South Africa (DM), and the Division of Mammals, National Museum of Natural History, Smithsonian Institution, United States (NMNH), were acquired and then sorted into a subset of specimens with associated coordinate data. The coordinate data were then used to develop distributional maps for the rodent genera present within the study area. Percent habitat occupation and descriptive statistics for six climatic variables were then determined for each genus by cross-referencing locality positions with vegetation and climatic maps. This report presents a series of maps illustrating the distribution of 35 rodent genera based on 19,471 geo-referenced specimens obtained from two major collections. Inferred habitat use by taxon is provided for both locality and specimen percent occurrence at three hierarchical habitat levels: biome, bioregion, and vegetation unit. Descriptive statistics for six climatic variables are also provided for each genus based on locality and specimen percent incidence. As rodent faunas are commonly used in paleoenvironmental reconstructions, an accurate assessment of rodent environmental tolerance ranges is necessary before confidence can be placed in an actualistic model. While the data presented here represent only a subset of the modern geographic distributions for many of the taxa examined, a wide range of environmental regimes are observed, suggesting that more research is necessary

  9. A Geographic Information Systems (GIS)-based analysis of modern South African rodent distributions, habitat use, and environmental tolerances.

    PubMed

    Campbell, Timothy L; Lewis, Patrick J; Thies, Monte L; Williams, Justin K

    2012-11-01

    GOALS OF THIS STUDY WERE TO: (1) develop distributional maps of modern rodent genera throughout the countries of South Africa, Lesotho, and Swaziland by georeferencing museum specimens; (2) assess habitat preferences for genera by cross-referencing locality position with South African vegetation; and (3) identify mean annual precipitation and temperature range where the genera are located. Conterminous South Africa including the countries of Lesotho and Swaziland Digital databases of rodent museum specimens housed in the Ditsong National Museum of Natural History, South Africa (DM), and the Division of Mammals, National Museum of Natural History, Smithsonian Institution, United States (NMNH), were acquired and then sorted into a subset of specimens with associated coordinate data. The coordinate data were then used to develop distributional maps for the rodent genera present within the study area. Percent habitat occupation and descriptive statistics for six climatic variables were then determined for each genus by cross-referencing locality positions with vegetation and climatic maps. This report presents a series of maps illustrating the distribution of 35 rodent genera based on 19,471 geo-referenced specimens obtained from two major collections. Inferred habitat use by taxon is provided for both locality and specimen percent occurrence at three hierarchical habitat levels: biome, bioregion, and vegetation unit. Descriptive statistics for six climatic variables are also provided for each genus based on locality and specimen percent incidence. As rodent faunas are commonly used in paleoenvironmental reconstructions, an accurate assessment of rodent environmental tolerance ranges is necessary before confidence can be placed in an actualistic model. While the data presented here represent only a subset of the modern geographic distributions for many of the taxa examined, a wide range of environmental regimes are observed, suggesting that more research is necessary

  10. Variation and geographical distribution of the genotypes controlling the diagnostic spike morphology of two varieties of Aegilops caudata l.

    PubMed

    Ohta, S

    2001-10-01

    Aegilops caudata L. is an annual wild relative of wheat distributed over the northeastern Mediterranean basin. It consists of two taxonomic varieties, var. typica with awnless lateral spikelets and var.polyathera with awned lateral spikelets. To clarify the variation and the geographical distribution of the genotypes controlling the diagnostic spike morphology of the two taxonomic varieties, three crossing experiments were carried out. First, two varieties collected from nine sympatric populations in the Aegean islands were crossed reciprocally. All of the F1 hybrids were var. typica and the segregation ratio in the F2 generation was 3 typica: 1 polyathera. Secondly, 13 typica accessions collected from the entire distribution area of the variety were crossed with a common polyathera accession. The F1 hybrids involving eight typica accessions from Greece and West Anatolia were var. typica, while those involving five typica accessions from East Anatolia, Syria and Iraq were var. polyathera. Thirdly, the typica F1 hybrids between the Aegean and the Syrian typica accessions were backcrossed to the latter. Four of the seven BC1F1 plants obtained were var. typica, but the other three were var. polyathera. Based on these results, the following two conclusions were made. First, the awnless lateral spikelets characteristic of var. typica are due to two different genotypes: one is a dominant allele suppressing awn development on lateral spikelets and the other is a recessive allele(s) for awnless lateral spikelets with no dominant suppressor allele. Secondly, the former genotype occurs only in the western region of the distribution area of the species, while the latter occurs in the eastern region. The present results and the recent palaeopalynological evidence also suggested that var. polyathera, with more awns than var. typica, rapidly colonized Central Anatolia from the Levant or East Taurus/Zagros mountains arc after the last glacial period. PMID:11817646

  11. Distributed and integrated response of a geographic information system-based hydrologic model in the eastern Palouse region, Idaho

    NASA Astrophysics Data System (ADS)

    Brooks, Erin S.; Boll, Jan; McDaniel, Paul A.

    2007-01-01

    Verification of distributed hydrologic models is rare owing to the lack of spatially detailed field measurements and a common mismatch between the scale at which soil hydraulic properties are measured and the scale of a single modelling unit. In this study, two of the most commonly calibrated parameters, i.e. soil depth and the vertical distribution of lateral saturated hydraulic conductivity Ks, were eliminated by a spatially detailed soil characterization and results of a hillslope-scale field experiment. The soil moisture routing (SMR) model, a geographic information system-based hydrologic model, was modified to represent the dominant hydrologic processes for the Palouse region of northern Idaho. Modifications included Ks as a double exponential function of depth in a single soil layer, a snow accumulation and melt algorithm, and a simple relationship between storage and perched water depth (PWD) using the drainable porosity. The model was applied to a 2 ha catchment without calibration to measured data. Distributed responses were compared with observed PWD over a 3-year period on a 10 m × 15 m grid. Integrated responses were compared with observed surface runoff at the catchment outlet. The modified SMR model simulated the PWD fluctuations remarkably well, especially considering the shallow soils in this catchment: a 0.20 m error in PWD is equivalent to only a 1.6% error in predicted soil moisture content. Simulations also captured PWD fluctuations during a year with high spatial variability of snow accumulation and snowmelt rates at upslope, mid-slope, and toe slope positions with errors as low as 0.09 m, 0.12 m, and 0.12 m respectively. Errors in distributed and integrated model simulations were attributed mostly to misrepresentation of rain events and snowmelt timing problems. In one location in the catchment, simulated PWD was consistently greater than observed PWD, indicating a localized recharge zone, which was not identified by the soil morphological

  12. Potential geographic distribution of atmospheric nitrogen deposition from intensive livestock production in North Carolina, USA.

    PubMed

    Costanza, Jennifer K; Marcinko, Sarah E; Goewert, Ann E; Mitchell, Charles E

    2008-07-15

    To examine the consequences of increased spatial aggregation of livestock production facilities, we estimated the annual production of nitrogen in livestock waste in North Carolina, USA, and analyzed the potential distribution of atmospheric nitrogen deposition from confined animal feeding operations ("CAFO") lagoons. North Carolina is a national center for industrial livestock production. Livestock is increasingly being raised in CAFOs, where waste is frequently held, essentially untreated, in open-air lagoons. Reduced nitrogen in lagoons is volatilized as ammonia (NH(3)), transported atmospherically, and deposited to other ecosystems. The Albemarle-Pamlico Sound, NC, is representative of nitrogen-sensitive coastal waters, and is a major component of the second largest estuarine complex in the U.S. We used GIS to model the area of water in the Sound within deposition range of CAFOs. We also evaluated the number of lagoons within deposition range of each 1 km(2) grid cell of the state. We considered multiple scenarios of atmospheric transport by varying distance and directionality. Modeled nitrogen deposition rates were particularly elevated for the Coastal Plain. This pattern matches empirical data, suggesting that observed regional patterns of reduced nitrogen deposition can be largely explained by two factors: limited atmospheric transport distance, and spatial aggregation of CAFOs. Under our medium-distance scenario, a small portion (roughly 22%) of livestock production facilities contributes disproportionately to atmospheric deposition of nitrogen to the Albemarle-Pamlico Sound. Furthermore, we estimated that between 14-37% of the state receives 50% of the state's atmospheric nitrogen deposition from CAFO lagoons. The estimated total emission from livestock is 134,000 t NH(3) yr(-1), 73% of which originates from the Coastal Plain. Stronger waste management and emission standards for CAFOs, particularly those on the Coastal Plain nearest to sensitive water

  13. Geographical distribution of surface temperature change over the 2003-2013 decade.

    NASA Astrophysics Data System (ADS)

    Dieng, H. B.; Cazenave, A. A.; Palanisamy, H. K.; Meyssignac, B.

    2015-12-01

    Global surface temperatures have increased less rapidly since the early 2000s than during the previous decades. This slowdown in global surface evolution (also called hiatus) has several possible causes, ranging from decreased net radiative forcing to internal rearrangement of heat inside the ocean between the surface and the deep ocean. Several studies have favored the latter explanation and have invoked different ocean basins as potential warming sinks. Here we investigate the regional distribution of the reported temperature slowdown during the 2003-2013 decade. We successively analyse land and ocean surface temperatures using different data sets. For the ocean, we use sea surface temperature data as well as ocean thermal expansion of the upper 100 m estimated with Argo measurements and ocean reanalyses. We find that during the study period (largely representative of the hiatus), land surface temperatures have increased at a rate not significantly lower than over the previous century. For the oceans, we estimated the surface temperature (and 0-100 m thermal expansion) in different latitudinal bands and different ocean basins and found that the most of the observed slowdown of the global mean surface temperature comes from the eastern tropical Pacific (20°S-20°N, 80°W-150°W). This region shows a significant cooling during the 2003-2013 decade, not seen elsewhere. Looking at seasonal variations, we also found that cooling dominantly occurs during the December-January-February season. Comparison of the eastern tropical Pacific sea surface temperature cooling with the global mean shows that the observed pause in the global mean surface temperature evolution of the recent years can be largely explained by this region. This result is well compatible with some recently proposed mechanisms of heat redistribution inside the ocean.

  14. Opisthorchis viverrini: life cycle, intermediate hosts, transmission to man and geographical distribution in Thailand.

    PubMed

    Harinasuta, C; Harinasuta, T

    1984-01-01

    Opisthorchis viverrini has been found to be the only species of liver fluke in Thailand. The morphology is similar to that of O. felineus, but it has more deeply lobated testes, situated near the ovary. The appearance and distribution of the vitellaria with few granular clumps and the shorter and wider egg closely resemble that of C. sinensis. The adult worms live in the biliary system. Eggs pass out in faeces. On reaching water the eggs are eaten by snails, the first intermediate host. In the snail the miracidia hatch and develop further through the stages of sporocysts, rediae and cercariae in six to eight weeks. The cercariae then leave the snail, penetrate into susceptible fresh water fish, encyst in the muscle and develop into metacercariae, and infective stage, in six weeks. When ingested by man or animal the metacercariae excyst in the duodenum or jejunum and then migrate to the bile duct. They become mature within four weeks and begin to produce eggs. The life span of the fluke is over 10 years. The snail intermediate hosts are Bithynia goniomphalus, B. funiculata and B. siamensis. Many species of cyprinoid fish serve as second intermediate host; Cyclocheilichthys siaja is the most important. Cats, dogs and many fish eating mammals are definitive hosts. Man and animals acquire infection by eating raw fish containing metacercariae cysts. In Northeast Thailand "Koi-Pla" is the most popular raw fish dish. In 1980-1981 the prevalence in the north, northeast, centre and south of Thailand was 5.59, 34.60, 6.34, and 0.01%, respectively, with an overall prevalence of 14% or 7 million people. PMID:6542383

  15. Assessing the Spatial Distribution of Perfluorooctanoic Acid Exposure via Public Drinking Water Pipes Using Geographic Information Systems

    PubMed Central

    Hoffman, Kate; Fletcher, Tony

    2013-01-01

    Objectives Geographic Information Systems (GIS) is a powerful tool for assessing exposure in epidemiologic studies. We used GIS to determine the geographic extent of contamination by perfluorooctanoic acid, C8 (PFOA) that was released into the environment from the DuPont Washington Works Facility located in Parkersburg, West Virginia. Methods Paper maps of pipe distribution networks were provided by six local public water districts participating in the community cross-sectional survey, the C8 Health Project. Residential histories were also collected in the survey and geocoded. We integrated the pipe networks and geocoded addresses to determine which addresses were serviced by one of the participating water districts. The GIS-based water district assignment was then compared to the participants' self-reported source of public drinking water. Results There were a total of 151,871 addresses provided by the 48,800 participants of the C8 Health Project that consented to geocoding. We were able to successfully geocode 139,067 (91.6%) addresses, and of these, 118,209 (85.0%) self-reported water sources were confirmed using the GIS-based method of water district assignment. Furthermore, the GIS-based method corrected 20,858 (15.0%) self-reported public drinking water sources. Over half (54%) the participants in the lowest GIS-based exposure group self-reported being in a higher exposed water district. Conclusions Not only were we able to correct erroneous self-reported water sources, we were also able to assign water districts to participants with unknown sources. Without the GIS-based method, the reliance on only self-reported data would have resulted in exposure misclassification. PMID:24010064

  16. Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia - application of geostatistical methods.

    PubMed

    Bossew, P; Žunić, Z S; Stojanovska, Z; Tollefsen, T; Carpentieri, C; Veselinović, N; Komatina, S; Vaupotič, J; Simović, R D; Antignani, S; Bochicchio, F

    2014-01-01

    Between 2008 and 2011 a survey of radon ((222)Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon maps" of expected concentrations and of estimated probabilities that a concentration threshold is exceeded. The resulting maps show a clearly structured spatial pattern which appears related to the geological background. In particular in areas with vulcanite and granitoid rocks, elevated radon (Rn) concentrations can be expected. The "school radon map" can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone areas, i.e. areas in which higher Rn radon concentrations can be expected for natural reasons. It must be stressed that the "radon hazard", or potential risk, estimated this way, has to be distinguished from the actual radon risk, which is a function of exposure. This in turn may require (depending on the target variable which is supposed to measure risk) considering demographic and sociological reality, i.e. population density, distribution of building styles and living habits. PMID:24231373

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

    PubMed

    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. PMID:26465729

  18. Assessing equity in the geographical distribution of community pharmacies in South Africa in preparation for a national health insurance scheme

    PubMed Central

    Sanders, David; Leng, Henry; Pollock, Allyson M

    2014-01-01

    Abstract Objective To investigate equity in the geographical distribution of community pharmacies in South Africa and assess whether regulatory reforms have furthered such equity. Methods Data on community pharmacies from the national department of health and the South African pharmacy council were used to analyse the change in community pharmacy ownership and density (number per 10 000 residents) between 1994 and 2012 in all nine provinces and 15 selected districts. In addition, the density of public clinics, alone and with community pharmacies, was calculated and compared with a national benchmark of one clinic per 10 000 residents. Interviews were conducted with nine national experts from the pharmacy sector. Findings Community pharmacies increased in number by 13% between 1994 and 2012 – less than the 25% population growth. In 2012, community pharmacy density was higher in urban provinces and was eight times higher in the least deprived districts than in the most deprived ones. Maldistribution persisted despite the growth of corporate community pharmacies. In 2012, only two provinces met the 1 per 10 000 benchmark, although all provinces achieved it when community pharmacies and clinics were combined. Experts expressed concerns that a lack of rural incentives, inappropriate licensing criteria and a shortage of pharmacy workers could undermine access to pharmaceutical services, especially in rural areas. Conclusion To reduce inequity in the distribution of pharmaceutical services, new policies and legislation are needed to increase the staffing and presence of pharmacies. PMID:25110373

  19. Geographical Distribution Patterns of Iodine in Drinking-Water and Its Associations with Geological Factors in Shandong Province, China

    PubMed Central

    Gao, Jie; Zhang, Zhijie; Hu, Yi; Bian, Jianchao; Jiang, Wen; Wang, Xiaoming; Sun, Liqian; Jiang, Qingwu

    2014-01-01

    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 < 0.001). Two clusters for high iodine in drinking-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. PMID:24852390

  20. How is Order 636 affecting the gas distribution industry

    SciTech Connect

    Margossian, K.M. )

    1993-12-01

    This paper is part of a six part series on how interstate gas pipelines have been affected by Order 636. These papers are written in an interview format with different individuals representing the pipeline, natural gas, utility, and regulatory side of this new regulation. The issues deal with how it has affected these industries; how the relationships have changed between suppliers, marketers, distributors, etc.; the risks now involved in marketing, shipping, and buying gas products; and new technology developments have resulted to comply with the new regulations. This paper is an interview with Kenneth M. Magossian, president and chief operating officer of Commonwealth Gas Co. and Hopkinton LNG Corp.

  1. Estimating the spatial distribution of PM2.5 concentration by integrating geographic data and field measurements

    NASA Astrophysics Data System (ADS)

    Zhai, L.; Sang, H.; Zhang, J.; An, F.

    2015-06-01

    Air quality directly affects the health and living of human beings, and it receives wide concern of public and attaches great important of governments at all levels. The estimation of the concentration distribution of PM2.5 and the analysis of its impacting factors is significant for understanding the spatial distribution regularity and further for decision supporting of governments. In this study, multiple sources of remote sensing and GIS data are utilized to estimate the spatial distribution of PM2.5 concentration in Shijiazhuang, China, by utilizing multivariate linear regression modelling, and integrating year average values of PM2.5 collected from local environment observing stations. Two major sources of PM2.5 are collected, including dust surfaces and industrial polluting sources. The area attribute of dust surfaces and point attribute of industrial polluting enterprises are extracted from high resolution remote sensing images and GIS data in 2013. 30m land cover products, annual average PM2.5 concentration values from the 8 environment monitoring stations, annual mean MODIS AOD data, traffic and DEM data are utilized in the study for regression modeling analysis. The multivariate regression analysis model is applied to estimate the spatial distribution of PM2.5 concentration. There is an upward trend of the spatial distribution of PM2.5 concentration gradually from west to east, of which the highest concentration appears in the municipal district and its surrounding areas. The spatial distribution pattern relatively fit the reality.

  2. Legal & regulatory issues affecting participation in distributed resource markets

    SciTech Connect

    Nimmons, J.T.

    1996-12-31

    This paper describes recent research co-sponsored by the National Renewable Energy Laboratory and four investor-owned utilities. Its purpose was to investigate how legal and regulatory factors will shape strategic decisions on the roles of utilities and others in the development of distributed resources. The work was performed during 1995 and early 1996 by John Nimmons & Associates, with support from Thomas J. Starts, Energy & Environmental Economics, and Awad & Singer.

  3. Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden

    PubMed Central

    2012-01-01

    Background Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB) spirochaetes, the tick-borne encephalitis virus (TBEV) and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland) and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. Methods A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Results Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N) where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the respondents, the abundance

  4. Host-parasite relationships and geographic distribution of Salmincola corpulentus (Copepoda: Lernaeopodidae) on bloater (Coregonus hoyi) stocks in Lake Huron

    USGS Publications Warehouse

    Bowen, Charles A.; Stedman, Ralph M.

    1990-01-01

    Examination of the branchial cavities of 8347 adult bloaters (Coregonus hoyi) collected from seven locations in Lake Huron for parasitic copepods yielded only the lernaeopodid Salmincola corpulentus; its distribution was limited to bloaters collected in the southern two-thirds of the lake. The infections were highest off Au Sable Point and on Six Fathom Bank, where 12 and 22%, of the bloaters examined were infected, respectively. All copepods seen were sexually mature females. The dorsal anterior portion of the branchial rim was the preferred site of attachment. The prevalence of S. corpulentus increased with length of the bloaters, reaching a maximum of 40% in fish longer than 330 mm; none were seen in bloaters shorter than 182 mm. The mean intensity of S. corpulentus was unusually low (1.0–1.9) for a lernaeopodid copepod and the maximum number of copepods found on a single bloater was five. Prevalences of copepods differed significantly (P < 0.05) between bloaters collected at different geographic locations, suggesting that S. corpulentus may be of value in bloater stock determination.

  5. Extent of Mangrove Nursery Habitats Determines the Geographic Distribution of a Coral Reef Fish in a South-Pacific Archipelago

    PubMed Central

    Paillon, Christelle; Wantiez, Laurent; Kulbicki, Michel; Labonne, Maylis; Vigliola, Laurent

    2014-01-01

    Understanding the drivers of species' geographic distribution has fundamental implications for the management of biodiversity. For coral reef fishes, mangroves have long been recognized as important nursery habitats sustaining biodiversity in the Western Atlantic but there is still debate about their role in the Indo-Pacific. Here, we combined LA-ICP-MS otolith microchemistry, underwater visual censuses (UVC) and mangrove cartography to estimate the importance of mangroves for the Indo-Pacific coral reef fish Lutjanus fulviflamma in the archipelago of New Caledonia. Otolith elemental compositions allowed high discrimination of mangroves and reefs with 83.8% and 98.7% correct classification, respectively. Reefs were characterized by higher concentrations of Rb and Sr and mangroves by higher concentrations of Ba, Cr, Mn and Sn. All adult L. fulviflamma collected on reefs presented a mangrove signature during their juvenile stage with 85% inhabiting mangrove for their entire juvenile life (about 1 year). The analysis of 2942 UVC revealed that the species was absent from isolated islands of the New Caledonian archipelago where mangroves were absent. Furthermore, strong positive correlations existed between the abundance of L. fulviflamma and the area of mangrove (r = 0.84 for occurrence, 0.93 for density and 0.89 for biomass). These results indicate that mangrove forest is an obligatory juvenile habitat for L. fulviflamma in New Caledonia and emphasize the potential importance of mangroves for Indo-Pacific coral reef fishes. PMID:25140697

  6. Approach to Geographical Distribution of Vocational Training and Training Delivery Methods. Job Corps Vocational Education Offerings Review. Documentation Report No. 6.

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. Job Corps.

    As part of a multiphased evaluation of vocational training provided by the Job Corps in fiscal year 1982, a study examined the approach used by the Job Corps toward geographic distribution of courses and training delivery. Because 14 occupations accounted for over one-half of the training analyzed in this study, the researchers recommended that…

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

    ERIC Educational Resources Information Center

    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…

  8. Do cleaning stations affect the distribution of territorial reef fishes?

    NASA Astrophysics Data System (ADS)

    Whiteman, Elizabeth A.; Côté, Isabelle M.; Reynolds, John D.

    2002-09-01

    We investigated the role of cleaning stations in determining the distribution of territorial reef species. Cleaner fish reduce their clients' ectoparasite loads and, therefore, proximity to cleaning stations should be advantageous for territorial fish. We focused on five damselfish species which hold permanent territories and cleaning stations occupied by cleaning gobies ( Elacatinus spp.) on a Caribbean reef. Contrary to our predictions of higher densities near cleaning stations, we found that bicolor damselfish were less abundant near cleaning stations than at ecologically similar points without cleaning gobies whereas no effects were seen for longfin, dusky, yellowtail, and threespot damselfish. In addition, although damselfish densities were higher in the immediate vicinity of cleaning stations than 1.5-3 m away for most species, this was also the case at points without cleaners. Because cleaning stations are usually located on prominent coral heads or sponges, the overall significant attraction of damselfish to such structures, whether occupied by cleaning gobies or not, could reflect attraction to past or potential cleaning stations. However, it is more likely that interspecific competition and/or the low benefits of being cleaned at our study site prevent aggregation around cleaners. Cleaning stations may play only a minor role in determining the distribution of territorial reef fishes.

  9. The impact of climate change on the geographical distribution of two vectors of Chagas disease: implications for the force of infection

    PubMed Central

    Medone, Paula; Ceccarelli, Soledad; Parham, Paul E.; Figuera, Andreína; Rabinovich, Jorge E.

    2015-01-01

    Chagas disease, caused by the parasite Trypanosoma cruzi, is the most important vector-borne disease in Latin America. The vectors are insects belonging to the Triatominae (Hemiptera, Reduviidae), and are widely distributed in the Americas. Here, we assess the implications of climatic projections for 2050 on the geographical footprint of two of the main Chagas disease vectors: Rhodnius prolixus (tropical species) and Triatoma infestans (temperate species). We estimated the epidemiological implications of current to future transitions in the climatic niche in terms of changes in the force of infection (FOI) on the rural population of two countries: Venezuela (tropical) and Argentina (temperate). The climatic projections for 2050 showed heterogeneous impact on the climatic niches of both vector species, with a decreasing trend of suitability of areas that are currently at high-to-moderate transmission risk. Consequently, climatic projections affected differently the FOI for Chagas disease in Venezuela and Argentina. Despite the heterogeneous results, our main conclusions point out a decreasing trend in the number of new cases of Tr. cruzi human infections per year between current and future conditions using a climatic niche approach. PMID:25688019

  10. The impact of climate change on the geographical distribution of two vectors of Chagas disease: implications for the force of infection.

    PubMed

    Medone, Paula; Ceccarelli, Soledad; Parham, Paul E; Figuera, Andreína; Rabinovich, Jorge E

    2015-04-01

    Chagas disease, caused by the parasite Trypanosoma cruzi, is the most important vector-borne disease in Latin America. The vectors are insects belonging to the Triatominae (Hemiptera, Reduviidae), and are widely distributed in the Americas. Here, we assess the implications of climatic projections for 2050 on the geographical footprint of two of the main Chagas disease vectors: Rhodnius prolixus (tropical species) and Triatoma infestans (temperate species). We estimated the epidemiological implications of current to future transitions in the climatic niche in terms of changes in the force of infection (FOI) on the rural population of two countries: Venezuela (tropical) and Argentina (temperate). The climatic projections for 2050 showed heterogeneous impact on the climatic niches of both vector species, with a decreasing trend of suitability of areas that are currently at high-to-moderate transmission risk. Consequently, climatic projections affected differently the FOI for Chagas disease in Venezuela and Argentina. Despite the heterogeneous results, our main conclusions point out a decreasing trend in the number of new cases of Tr. cruzi human infections per year between current and future conditions using a climatic niche approach. PMID:25688019

  11. Development of Peptide-Based Lineage-Specific Serology for Chronic Chagas Disease: Geographical and Clinical Distribution of Epitope Recognition

    PubMed Central

    Bhattacharyya, Tapan; Falconar, Andrew K.; Luquetti, Alejandro O.; Costales, Jaime A.; Grijalva, Mario J.; Lewis, Michael D.; Messenger, Louisa A.; Tran, Trang T.; Ramirez, Juan-David; Guhl, Felipe; Carrasco, Hernan J.; Diosque, Patricio; Garcia, Lineth; Litvinov, Sergey V.; Miles, Michael A.

    2014-01-01

    Background Chagas disease, caused by infection with the protozoan Trypanosoma cruzi, remains a serious public health issue in Latin America. Genetically diverse, the species is sub-divided into six lineages, known as TcI–TcVI, which have disparate geographical and ecological distributions. TcII, TcV, and TcVI are associated with severe human disease in the Southern Cone countries, whereas TcI is associated with cardiomyopathy north of the Amazon. T. cruzi persists as a chronic infection, with cardiac and/or gastrointestinal symptoms developing years or decades after initial infection. Identifying an individual's history of T. cruzi lineage infection directly by genotyping of the parasite is complicated by the low parasitaemia and sequestration in the host tissues. Methodology/Principal Findings We have applied here serology against lineage-specific epitopes of the T. cruzi surface antigen TSSA, as an indirect approach to allow identification of infecting lineage. Chagasic sera from chronic patients from a range of endemic countries were tested by ELISA against synthetic peptides representing lineage-specific TSSA epitopes bound to avidin-coated ELISA plates via a biotin labelled polyethylene glycol-glycine spacer to increase rotation and ensure each amino acid side chain could freely interact with their antibodies. 79/113 (70%) of samples from Brazil, Bolivia, and Argentina recognised the TSSA epitope common to lineages TcII/TcV/TcVI. Comparison with clinical information showed that a higher proportion of Brazilian TSSApep-II/V/VI responders had ECG abnormalities than non-responders (38% vs 17%; p<0.0001). Among northern chagasic sera 4/20 (20%) from Ecuador reacted with this peptide; 1/12 Venezuelan and 1/34 Colombian samples reacted with TSSApep-IV. In addition, a proposed TcI-specific epitope, described elsewhere, was demonstrated here to be highly conserved across lineages and therefore not applicable to lineage-specific serology. Conclusions

  12. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Distributions in liquidation as affecting minority interests. 1.332-5 Section 1.332-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Corporate Liquidations § 1.332-5 Distributions in liquidation as affecting minority...

  13. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 4 2011-04-01 2011-04-01 false Distributions in liquidation as affecting... TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Corporate Liquidations § 1.332-5 Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance of a plan...

  14. Resource distributions affect social learning on multiple timescales.

    PubMed

    van der Post, Daniel J; Ursem, Bas; Hogeweg, Paulien

    2009-09-01

    We study how learning is shaped by foraging opportunities and self-organizing processes and how this impacts on the effects of "copying what neighbors eat" on multiple timescales. We use an individual-based model with a rich environment, where group foragers learn what to eat. We vary foraging opportunities by changing local variation in resources, studying copying in environments with pure patches, varied patches, and uniform distributed resources. We find that copying can help individuals explore the environment by sharing information, but this depends on how foraging opportunities shape the learning process. Copying has the greatest impact in varied patches, where local resource variation makes learning difficult, but local resource abundance makes copying easy. In contrast, copying is redundant or excessive in pure patches where learning is easy, and mostly ineffective in uniform environments where learning is difficult. Our results reveal that the mediation of copying behavior by individual experience is crucial for the impact of copying. Moreover, we find that the dynamics of social learning at short timescales shapes cultural phenomena. In fact, the integration of learning on short and long timescales generates cumulative cultural improvement in diet. Our results therefore provide insight into how and when such processes can arise. These insights need to be taken into account when considering behavioral patterns in nature. PMID:19701483

  15. Knee osteoarthritis affects the distribution of joint moments during gait.

    PubMed

    Zeni, Joseph A; Higginson, Jill S

    2011-06-01

    Alterations in lower extremity kinetics have been shown to exist in persons with knee osteoarthritis (OA), however few investigations have examined how the intersegmental coordination of the lower extremity kinetic chain varies in the presence of knee joint pathology. The objective of this study was to evaluate how knee OA and walking speed affect total support moment and individual joint contributions to the total support moment. Fifteen healthy subjects and 30 persons with knee OA participated in 3D walking analysis at constrained (1.0 m/s), self-selected and fastest tolerable walking speeds. Individual joint contributions to total support moment were analyzed using separate ANOVAs with one repeated measure (walking speed). Linear regression analysis was used to evaluate the relationship between walking speed and joint contribution. Persons with knee OA reduced the contribution of the knee joint when walking at constrained (p = 0.04) and self-selected walking speeds (p = 0.009). There was a significant increase in the ankle contribution and a significant decrease in the hip contribution when walking speed was increased (p < 0.004), however individual walking speeds were not significantly related to joint contributions. This suggests that the relationship between walking speed and joint contribution is dependent on the individual's control strategy and we cannot estimate the joint contribution solely based on walking speed. The slower gait speed observed in persons with knee OA is not responsible for the reduction in knee joint moments, rather this change is likely due to alterations in the neuromuscular strategy of the lower extremity kinetic chain in response to joint pain or muscle weakness. PMID:20510618

  16. Variability in the Geographic Distribution of Fires in Interior Alaska Considering Cause, Human Proximity, and Level of Suppression

    NASA Astrophysics Data System (ADS)

    Calef, M. P.; Varvak, A.; McGuire, A. D.; Chapin, T.

    2015-12-01

    The boreal forest of Interior Alaska is characterized by frequent extensive wildfires that have been mapped for the past 70 years. Simple predictions based on this record indicate that area burned will increase as a response to climate warming in Alaska. However, two additional factors have affected the area burned in this time record: the Pacific Decadal Oscillation (PDO) switched from cool and moist to warm and dry in the late 1970s and the Alaska Fire Service instituted a fire suppression policy in the late 1980s. Using Geographic Information Systems (GIS) and statistics, this presentation evaluates the variability in area burned and fire ignitions in Interior Alaska in space and time with particular emphasis on the human influence via ignition and suppression. Our analysis shows that while area burned has been increasing by 2.4% per year, the number of lightning ignitions has decreased by 1.9 ignitions per year. Human ignitions account for 50% of all fire ignitions in Interior Alaska and are clearly influenced by human proximity: human fires mostly occur close to settlements, highways and in intense fire suppression zones (which are in turn close to human settlements and roads); fires close to settlements, highways and in intense fire suppression zones burn much shorter than fires further away from this sphere of human influence; and 60% of all human fire ignitions in Interior Alaska are concentrated in the Fairbanks area and thereby strongly influence regional analyses. Fire suppression has effectively reduced area burned since it was implemented but the PDO change has also had some influence. Finally, we found that human fires start earlier in the year and burn for a shorter duration than lightning fires. This study provides insights into the importance of human behavior as well as regional climate patterns as large-scale controls on fires over time and across the Alaskan boreal forest.

  17. Geographical Distributions of Rotylenchulus reniformis, Meloidogyne incognita, and Tylenchulus semipenetrans in the Lower Rio Grande Valley as Related to Soil Texture and Land Use.

    PubMed

    Robinson, A F; Heald, C M; Flanagan, S L; Thames, W H; Amador, J

    1987-10-01

    A survey was conducted over a 22-year period to evaluate the influence of soil texture and land use on the geographical distributions of Rotylenchulus reniformis, Meloidogyne incognita, and Tylenchulus semipenetrans in the lower Rio Grande valley. The distributions of R. reniformis and M. incognita were related to soil texture, whereas T. semipenetrans occurred wherever host plants were present regardless of soil texture. The incidence of M. incognita was greatest in elevated sandy loams and moderately well-drained silts of modern flood terraces of the Rio Grande river. Rotylenchulus reniformis occurred predominantly in clay silts and clays of ancient flood terraces. Clay loams and sandy clay loams of the central, irrigated portion of the lower Rio Grande valley appeared favorable for M. incognita and R. reniformis. Differences between the geographical distributions of these two species could not be attributed to host crops. PMID:19290268

  18. Geographical Distributions of Rotylenchulus reniformis, Meloidogyne incognita, and Tylenchulus semipenetrans in the Lower Rio Grande Valley as Related to Soil Texture and Land Use

    PubMed Central

    Robinson, A. F.; Heald, C. M.; Flanagan, S. L.; Thames, W. H.; Amador, J.

    1987-01-01

    A survey was conducted over a 22-year period to evaluate the influence of soil texture and land use on the geographical distributions of Rotylenchulus reniformis, Meloidogyne incognita, and Tylenchulus semipenetrans in the lower Rio Grande valley. The distributions of R. reniformis and M. incognita were related to soil texture, whereas T. semipenetrans occurred wherever host plants were present regardless of soil texture. The incidence of M. incognita was greatest in elevated sandy loams and moderately well-drained silts of modern flood terraces of the Rio Grande river. Rotylenchulus reniformis occurred predominantly in clay silts and clays of ancient flood terraces. Clay loams and sandy clay loams of the central, irrigated portion of the lower Rio Grande valley appeared favorable for M. incognita and R. reniformis. Differences between the geographical distributions of these two species could not be attributed to host crops. PMID:19290268

  19. Spatial analysis of egg distribution and geographic changes in the spawning habitat of the Brazilian sardine Sardinella brasiliensis.

    PubMed

    Gigliotti, E S; Gherardi, D F M; Paes, E T; Souza, R B; Katsuragawa, M

    2010-12-01

    This paper establishes the spawning habitat of the Brazilian sardine Sardinella brasiliensis and investigates the spatial variability of egg density and its relation with oceanographic conditions in the shelf of the south-east Brazil Bight (SBB). The spawning habitats of S. brasiliensis have been defined in terms of spatial models of egg density, temperature-salinity plots, quotient (Q) analysis and remote sensing data. Quotient curves (Q(C)) were constructed using the geographic distribution of egg density, temperature and salinity from samples collected during nine survey cruises between 1976 and 1993. The interannual sea surface temperature (SST) variability was determined using principal component analysis on the SST anomalies (SSTA) estimated from remote sensing data over the period between 1985 and 2007. The spatial pattern of egg occurrences in the SBB indicated that the largest concentration occurred between Paranaguá and São Sebastião. Spawning habitat expanded and contracted during the years, fluctuating around Paranaguá. In January 1978 and January 1993, eggs were found nearly everywhere along the inner shelf of the SBB, while in January 1988 and 1991 spawning had contracted to their southernmost position. The SSTA maps for the spawning periods showed that in the case of habitat expansion (1993 only) anomalies over the SBB were zero or slightly negative, whereas for the contraction period anomalies were all positive. Sardinella brasiliensis is capable of exploring suitable spawning sites provided by the entrainment of the colder and less-saline South Atlantic Central Water onto the shelf by means of both coastal wind-driven (to the north-east of the SBB) and meander-induced (to the south-west of the SBB) upwelling. PMID:21155781

  20. Mycobacterial disease in cats in Great Britain: I. Culture results, geographical distribution and clinical presentation of 339 cases.

    PubMed

    Gunn-Moore, Danièlle A; McFarland, Sarah E; Brewer, Jacqueline I; Crawshaw, Timothy R; Clifton-Hadley, Richard S; Kovalik, Marcel; Shaw, Darren J

    2011-12-01

    This study investigated 339 cases of feline mycobacterial disease from cats with cutaneous lesions or masses found at exploratory laparotomy. Tissue samples were submitted to the Veterinary Laboratories Agency for mycobacterial culture over a 4-year period to December 2008. The study assessed which species of culturable mycobacteria were involved, where the cats lived, and their clinical presentation (physical findings, serum biochemistry, radiography, feline leukaemia virus and feline immunodeficiency virus status). Mycobacterium microti was cultured from 19%, Mycobacterium bovis 15%, Mycobacterium avium 7%, non-M avium non-tuberculous mycobacteria 6%, with no growth in 53% of samples. M microti, M bovis and M avium were found in almost mutually exclusive clusters within Great Britain (GB) (ie, M bovis in South-West England/Wales/Welsh Border, M avium in eastern England and M microti south of London and in South-West Scotland). While differences were seen in the clinical presentation and distribution of lesions caused by the different infections, these were not sufficiently different to be diagnostic. Cats commonly presented with single or multiple cutaneous lesions (74%), which were sometimes ulcerated or discharging, located most frequently on the head (54%). Lymph nodes were usually involved (47%); typically the submandibular nodes. Systemic or pulmonary signs were rarely seen (10-16%). When a cat is suspected of having mycobacteriosis, accurate identification of the species involved helps to determine appropriate action. Our findings show that knowing the cat's geographic location can be helpful, while the nature of the clinical presentation is less useful. Most cases of feline mycobacterial disease in GB are cutaneous. PMID:22079343

  1. Evaluating the aggregate effect of geographical isolated wetlands and associated spatial and size distributions on downstream hydrologic flows

    EPA Science Inventory

    Geographically isolated wetlands (GIW), defined as depressional wetlands completely surrounded by uplands, support an array of ecological processes. A solid scientific understanding of the hydrologic effects of GIWs upon downstream waterways is important for legal and policy-mak...

  2. How the Assumed Size Distribution of Dust Minerals Affects the Predicted Ice Forming Nuclei

    NASA Technical Reports Server (NTRS)

    Perlwitz, Jan P.; Fridlind, Ann M.; Garcia-Pando, Carlos Perez; Miller, Ron L.; Knopf, Daniel A.

    2015-01-01

    The formation of ice in clouds depends on the availability of ice forming nuclei (IFN). Dust aerosol particles are considered the most important source of IFN at a global scale. Recent laboratory studies have demonstrated that the mineral feldspar provides the most efficient dust IFN for immersion freezing and together with kaolinite for deposition ice nucleation, and that the phyllosilicates illite and montmorillonite (a member of the smectite group) are of secondary importance.A few studies have applied global models that simulate mineral specific dust to predict the number and geographical distribution of IFN. These studies have been based on the simple assumption that the mineral composition of soil as provided in data sets from the literature translates directly into the mineral composition of the dust aerosols. However, these tables are based on measurements of wet-sieved soil where dust aggregates are destroyed to a large degree. In consequence, the size distribution of dust is shifted to smaller sizes, and phyllosilicates like illite, kaolinite, and smectite are only found in the size range 2 m. In contrast, in measurements of the mineral composition of dust aerosols, the largest mass fraction of these phyllosilicates is found in the size range 2 m as part of dust aggregates. Conversely, the mass fraction of feldspar is smaller in this size range, varying with the geographical location. This may have a significant effect on the predicted IFN number and its geographical distribution.An improved mineral specific dust aerosol module has been recently implemented in the NASA GISS Earth System ModelE2. The dust module takes into consideration the disaggregated state of wet-sieved soil, on which the tables of soil mineral fractions are based. To simulate the atmospheric cycle of the minerals, the mass size distribution of each mineral in aggregates that are emitted from undispersed parent soil is reconstructed. In the current study, we test the null

  3. The Geographic Distribution of a Tropical Montane Bird Is Limited by a Tree: Acorn Woodpeckers (Melanerpes formicivorus) and Colombian Oaks (Quercus humboldtii) in the Northern Andes

    PubMed Central

    2015-01-01

    Species distributions are limited by a complex array of abiotic and biotic factors. In general, abiotic (climatic) factors are thought to explain species’ broad geographic distributions, while biotic factors regulate species’ abundance patterns at local scales. We used species distribution models to test the hypothesis that a biotic interaction with a tree, the Colombian oak (Quercus humboldtii), limits the broad-scale distribution of the Acorn Woodpecker (Melanerpes formicivorus) in the Northern Andes of South America. North American populations of Acorn Woodpeckers consume acorns from Quercus oaks and are limited by the presence of Quercus oaks. However, Acorn Woodpeckers in the Northern Andes seldom consume Colombian oak acorns (though may regularly drink sap from oak trees) and have been observed at sites without Colombian oaks, the sole species of Quercus found in South America. We found that climate-only models overpredicted Acorn Woodpecker distribution, suggesting that suitable abiotic conditions (e.g. in northern Ecuador) exist beyond the woodpecker’s southern range margin. In contrast, models that incorporate Colombian oak presence outperformed climate-only models and more accurately predicted the location of the Acorn Woodpecker’s southern range margin in southern Colombia. These findings support the hypothesis that a biotic interaction with Colombian oaks sets Acorn Woodpecker’s broad-scale geographic limit in South America, probably because Acorn Woodpeckers rely on Colombian oaks as a food resource (possibly for the oak’s sap rather than for acorns). Although empirical examples of particular plants limiting tropical birds’ distributions are scarce, we predict that similar biotic interactions may play an important role in structuring the geographic distributions of many species of tropical montane birds with specialized foraging behavior. PMID:26083262

  4. Homologous haplotypes, expression, genetic effects and geographic distribution of the wheat yield gene TaGW2

    PubMed Central

    2014-01-01

    Background TaGW2-6A, cloned in earlier research, strongly influences wheat grain width and TKW. Here, we mainly analyzed haplotypes of TaGW2-6B and their effects on TKW and interaction with haplotypes at TaGW2-6A. Results About 2.9 kb of the promoter sequences of TaGW2-6B and TaGW2-6D were cloned in 34 bread wheat cultivars. Eleven SNPs were detected in the promoter region of TaGW2-6B, forming 4 haplotypes, but no divergence was detected in the TaGW2-6D promoter or coding region. Three molecular markers including CAPS, dCAPS and ACAS, were developed to distinguish the TaGW2-6B haplotypes. Haplotype association analysis indicated that TaGW2-6B has a stronger influence than TaGW2-6A on TKW, and Hap-6B-1 was a favored haplotype increasing grain width and weight that had undergone strong positive selection in global wheat breeding. However, clear geographic distribution differences for TaGW2-6A haplotypes were found; Hap-6A-A was favored in Chinese, Australian and Russian cultivars, whereas Hap-6A-G was preferred in European, American and CIMMYT cultivars. This difference might be caused by a flowering and maturity time difference between the two haplotypes. Hap-6A-A is the earlier type. Haplotype interaction analysis between TaGW2-6A and TaGW2-6B showed additive effects between the favored haplotypes. Hap-6A-A/Hap-6B-1 was the best combination to increase TKW. Relative expression analysis of the three TaGW2 homoeologous genes in 22 cultivars revealed that TaGW2-6A underwent the highest expression. TaGW2-6D was the least expressed during grain development and TaGW2-6B was intermediate. Diversity of the three genes was negatively correlated with their effect on TKW. Conclusions Genetic effects, expression patterns and historic changes of haplotypes at three homoeologous genes of TaGW2 influencing yield were dissected in wheat cultivars. Strong and constant selection to favored haplotypes has been found in global wheat breeding during the past century. This research

  5. Molecular subdivision of the marine diatom Thalassiosira rotula in relation to geographic distribution, genome size, and physiology

    PubMed Central

    2012-01-01

    Background Marine phytoplankton drift passively with currents, have high dispersal potentials and can be comprised of morphologically cryptic species. To examine molecular subdivision in the marine diatom Thalassiosira rotula, variations in rDNA sequence, genome size, and growth rate were examined among isolates collected from the Atlantic and Pacific Ocean basins. Analyses of rDNA included T. gravida because morphological studies have argued that T. rotula and T. gravida are conspecific. Results Culture collection isolates of T. gravida and T. rotula diverged by 7.0 ± 0.3% at the ITS1 and by 0.8 ± 0.03% at the 28S. Within T. rotula, field and culture collection isolates were subdivided into three lineages that diverged by 0.6 ± 0.3% at the ITS1 and 0% at the 28S. The predicted ITS1 secondary structure revealed no compensatory base pair changes among lineages. Differences in genome size were observed among isolates, but were not correlated with ITS1 lineages. Maximum acclimated growth rates of isolates revealed genotype by environment effects, but these were also not correlated with ITS1 lineages. In contrast, intra-individual variation in the multi-copy ITS1 revealed no evidence of recombination amongst lineages, and molecular clock estimates indicated that lineages diverged 0.68 Mya. The three lineages exhibited different geographic distributions and, with one exception, each field sample was dominated by a single lineage. Conclusions The degree of inter- and intra-specific divergence between T. gravida and T. rotula suggests they should continue to be treated as separate species. The phylogenetic distinction of the three closely-related T. rotula lineages was unclear. On the one hand, the lineages showed no physiological differences, no consistent genome size differences and no significant changes in the ITS1 secondary structure, suggesting there are no barriers to interbreeding among lineages. In contrast, analysis of intra-individual variation in the

  6. Species From the Heliothinae Complex (Lepidoptera: Noctuidae) in Tucumán, Argentina, an Update of Geographical Distribution of Helicoverpa armigera

    PubMed Central

    Murúa, M. Gabriela; Cazado, Lucas E.; Casmuz, Augusto; Herrero, M. Inés; Villagrán, M. Elvira; Vera, Alejandro; Sosa-Gómez, Daniel R.; Gastaminza, Gerardo

    2016-01-01

    The Heliothinae complex in Argentina encompasses Helicoverpa gelotopoeon (Dyar), Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner), and Chloridea virescens (Fabricius). In Tucumán, the native species H. gelotopoeon is one of the most voracious soybean pests and also affects cotton and chickpea, even more in soybean-chickpea succession cropping systems. Differentiation of the Heliothinae complex in the egg, larva, and pupa stages is difficult. Therefore, the observation of the adult wing pattern design and male genitalia is useful to differentiate species. The objective of this study was to identify the species of the Heliothinae complex, determine population fluctuations of the Heliothinae complex in soybean and chickpea crops using male moths collected in pheromone traps in Tucuman province, and update the geographical distribution of H. armigera in Argentina. The species found were H. gelotopoeon, H. armigera, H. zea, and C. virescens. Regardless of province, county, crop, and year, the predominant species was H. gelotopoeon. Considering the population dynamics of H. gelotopoeon and H. armigera in chickpea and soybean crops, H. gelotopoeon was the most abundant species in both crops, in all years sampled, and the differences registered were significant. On the other hand, according to the Sistema Nacional Argentino de Vigilancia y Monitoreo de Plagas (SINAVIMO) database and our collections, H. armigera was recorded in eight provinces and 20 counties of Argentina, and its larvae were found on soybean, chickpea, sunflower crops and spiny plumeless thistle (Carduus acanthoides). This is the first report of H. armigera in sunflower and spiny plumeless thistle in Argentina. PMID:27324588

  7. Species From the Heliothinae Complex (Lepidoptera: Noctuidae) in Tucumán, Argentina, an Update of Geographical Distribution of Helicoverpa armigera.

    PubMed

    Murúa, M Gabriela; Cazado, Lucas E; Casmuz, Augusto; Herrero, M Inés; Villagrán, M Elvira; Vera, Alejandro; Sosa-Gómez, Daniel R; Gastaminza, Gerardo

    2016-01-01

    The Heliothinae complex in Argentina encompasses Helicoverpa gelotopoeon (Dyar), Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner), and Chloridea virescens (Fabricius). In Tucumán, the native species H. gelotopoeon is one of the most voracious soybean pests and also affects cotton and chickpea, even more in soybean-chickpea succession cropping systems. Differentiation of the Heliothinae complex in the egg, larva, and pupa stages is difficult. Therefore, the observation of the adult wing pattern design and male genitalia is useful to differentiate species. The objective of this study was to identify the species of the Heliothinae complex, determine population fluctuations of the Heliothinae complex in soybean and chickpea crops using male moths collected in pheromone traps in Tucuman province, and update the geographical distribution of H. armigera in Argentina. The species found were H. gelotopoeon, H. armigera, H. zea, and C. virescens. Regardless of province, county, crop, and year, the predominant species was H. gelotopoeon Considering the population dynamics of H. gelotopoeon and H. armigera in chickpea and soybean crops, H. gelotopoeon was the most abundant species in both crops, in all years sampled, and the differences registered were significant. On the other hand, according to the Sistema Nacional Argentino de Vigilancia y Monitoreo de Plagas (SINAVIMO) database and our collections, H. armigera was recorded in eight provinces and 20 counties of Argentina, and its larvae were found on soybean, chickpea, sunflower crops and spiny plumeless thistle (Carduus acanthoides). This is the first report of H. armigera in sunflower and spiny plumeless thistle in Argentina. PMID:27324588

  8. Relative influences of ocean acidification and temperature on intertidal barnacle post-larvae at the northern edge of their geographic distribution

    NASA Astrophysics Data System (ADS)

    Findlay, Helen S.; Kendall, Michael A.; Spicer, John I.; Widdicombe, Stephen

    2010-03-01

    The Arctic Ocean and its associated ecosystems face numerous challenges over the coming century. Increasing atmospheric CO 2 is causing increasing warming and ice melting as well as a concomitant change in ocean chemistry ("ocean acidification"). As temperature increases it is expected that many temperate species will expand their geographic distribution northwards to follow this thermal shift; however with the addition of ocean acidification this transition may not be so straightforward. Here we investigate the potential impacts of ocean acidification and climate change on populations of an intertidal species, in this case the barnacle Semibalanus balanoides, at the northern edge of its range. Growth and development of metamorphosing post-larvae were negatively impacted at lower pH (pH 7.7) compared to the control (pH 8.1) but were not affected by elevated temperature (+4 °C). The mineral composition of the shells did not alter under any of the treatments. The combination of reduced growth and maintained mineral content suggests that there may have been a change in the energetic balance of the exposed animals. In undersaturated conditions more mineral is expected to dissolve from the shell and hence more energy would be required to maintain the mineral integrity. Any energy that would normally be invested into growth could be reallocated and hence organisms growing in lowered pH grow slower and end up smaller than individuals grown in higher pH conditions. The idea of reallocation of resources under different conditions of pH requires further investigation. However, there could be long-term implications on the fitness of these barnacles, which in turn may prevent them from successfully colonising new areas.

  9. Geographic Distributions of Idh-1 Alleles in a Cricket are Linked to Differential Enzyme Kinetic Performance Across Thermal Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geographic clines within species are often interpreted as evidence of adaptation to varying environmental conditions. However, clines can also result from genetic drift, and these competing hypotheses must therefore be tested empirically. The striped ground cricket, Allonemobius socius, is widely-di...

  10. Mapping Arctic Coastline Change With Object-Based Image Analysis of Temporally and Geographically Distributed Landsat Archive Data

    NASA Astrophysics Data System (ADS)

    Hulslander, D.

    2011-12-01

    USGS EROS Data Center Archive. Hand-digitization of Arctic Ocean coastline changes over several decades would require an impractical amount of time and expense and would introduce additional error due to analyst differences in image feature interpretation. Object-based image analysis techniques have been shown (Hulslander, et al., 2008; GEOBIA 2008 Proceedings) to produce results similar to but more consistent than those from groups of human analysts. Earlier work has shown (Hulslander, 2010; AGU Fall Meeting) that using object-based analysis on Landsat Archive data can be used to map Arctic Ocean coastline change within a Landsat scene. Here, results show that this approach can be extended and automated to stably map Arctic Ocean coastline change in Landsat datasets distributed both geographically and temporally. Furthermore, these preliminary results indicate the possibility of producing a pan-Arctic Ocean coastline map on a roughly triennial basis for the past 30-plus years.

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

    PubMed Central

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

    2014-01-01

    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. PMID:23227821

  12. Geographic and stratigraphic distribution of coastal Quaternary aminozones across the Cape Fear Arch, U. S. Atlantic Geology Coastal Plain

    SciTech Connect

    Wehmiller, J.F.; York, L.L. ); Krantz, D.E. . Coll. of Marine Studies)

    1992-01-01

    The interpretation of the regional aminostratigraphy of Coastal Plain Quaternary units from North and South Carolina is potentially affected by sampling biases, variable preservation of coastal records, reoccupation of coastal environments by multiple transgressions, geochemical alteration of samples, variable thermal histories of specific samples, and intergeneric and interlaboratory differences in analytical results.Two primary models for the correlation of emergent Coastal Plain units diverge significantly in southeastern North Carolina. New data from fresh exposure (1990--1991) at emergent sites between Wilmington, NC and Charleston, SC, from previous onshore collections in this region, and from submergent samples between Cape Lookout, NC and Cape Romain, SC provide insight into the nature of these correlation issues. Although sampling of the area is not uniform, these results fill a major gap between regions of previous aminostratigraphy study. Inferred early-to-middle Pleistocene aminozones dominate the emergent coastal region between Cape Lookout and Romain, and late Pleistocene aminozones in this area are represented by subsurface samples beneath barrier islands or in shallow inner shelf cores, but have not been found onshore. A map view of the distribution of aminozones along the coast between northeastern NC and central SC mimics that of pre-Quaternary units that thin or disappear over the axis of the Cape Fear Arch, suggesting that the sampled Quaternary record reflects the combination of processes responsible for the preservation of the pre-Quaternary record. This perspective should provide a model for resolution of various geochronological controversies that have arisen because of limited stratigraphic or geochemical data.

  13. Biases in grant proposal success rates, funding rates and award sizes affect the geographical distribution of funding for biomedical research.

    PubMed

    Wahls, Wayne P

    2016-01-01

    The ability of the United States to most efficiently make breakthroughs on the biology, diagnosis and treatment of human diseases requires that physicians and scientists in each state have equal access to federal research grants and grant dollars. However, despite legislative and administrative efforts to ensure equal access, the majority of funding for biomedical research is concentrated in a minority of states. To gain insight into the causes of such disparity, funding metrics were examined for all NIH research project grants (RPGs) from 2004 to 2013. State-by-state differences in per application success rates, per investigator funding rates, and average award size each contributed significantly to vast disparities (greater than 100-fold range) in per capita RPG funding to individual states. To the extent tested, there was no significant association overall between scientific productivity and per capita funding, suggesting that the unbalanced allocation of funding is unrelated to the quality of scientists in each state. These findings reveal key sources of bias in, and new insight into the accuracy of, the funding process. They also support evidence-based recommendations for how the NIH could better utilize the scientific talent and capacity that is present throughout the United States. PMID:27077009

  14. Biases in grant proposal success rates, funding rates and award sizes affect the geographical distribution of funding for biomedical research

    PubMed Central

    2016-01-01

    The ability of the United States to most efficiently make breakthroughs on the biology, diagnosis and treatment of human diseases requires that physicians and scientists in each state have equal access to federal research grants and grant dollars. However, despite legislative and administrative efforts to ensure equal access, the majority of funding for biomedical research is concentrated in a minority of states. To gain insight into the causes of such disparity, funding metrics were examined for all NIH research project grants (RPGs) from 2004 to 2013. State-by-state differences in per application success rates, per investigator funding rates, and average award size each contributed significantly to vast disparities (greater than 100-fold range) in per capita RPG funding to individual states. To the extent tested, there was no significant association overall between scientific productivity and per capita funding, suggesting that the unbalanced allocation of funding is unrelated to the quality of scientists in each state. These findings reveal key sources of bias in, and new insight into the accuracy of, the funding process. They also support evidence-based recommendations for how the NIH could better utilize the scientific talent and capacity that is present throughout the United States. PMID:27077009

  15. Geographical distribution of organochlorine pesticides (OCPs) in polar bears (Ursus maritimus) in the Norwegian and Russian Arctic

    USGS Publications Warehouse

    Lie, E.; Bernhoft, A.; Riget, F.; Belikov, Stanislav; Boltunov, Andrei N.; Derocher, A.E.; Garner, G.W.; Wiig, O.; Skaare, J.U.

    2003-01-01

    Geographical variation of organochlorine pesticides (OCPs) was studied in blood samples from 90 adult female polar bear (Ursus maritimus) from Svalbard, Franz Josef Land, Kara Sea, East-Siberian Sea and Chukchi Sea. In all regions, oxychlordane was the dominant OCP. Regional differences in mean levels of HCB, oxychlordane, trans-nonachlor, ??-HCH, ??-HCH and p,p???-DDE were found. The highest levels of oxychlordane, trans-nonachlor and DDE were found in polar bears from Franz Josef Land and Kara Sea. HCB level was lowest in polar bears from Svalbard. Polar bears from Chukchi Sea had the highest level of ??- and ??-HCH. The lowest ??-HCH concentration was found in bears from Kara Sea. In all the bears, ???HCHs was dominated by ??-HCH. The geographical variation in OCP levels and pattern may suggest regional differences in pollution sources and different feeding habits in the different regions. Polar bears from the Western Russian Arctic were exposed to higher levels of chlordanes and p,p???-DDE than polar bears from locations westwards and eastwards from this region. This may imply the presence of a significant pollution source in the Russian Arctic area. The study suggests that the western Russian Arctic is the most contaminated region of the Arctic and warrants further research. ?? 2002 Elsevier Science B.V. All rights reserved.

  16. Contrasting Geographic Distribution Profiles of the Herpes Simplex Virus Type 1 BgOL and BgKL Variants in Japan Suggest Dispersion and Replacement▿

    PubMed Central

    Eda, Hiroyuki; Ozawa, Shigeru; Yoshino, Kamesaburo; Yanagi, Kazuo

    2007-01-01

    Thelifelong latent infection-reactivation mode of infection of herpes simplex virus type 1 (HSV-1) transmitted by close contact has allowed a diversity of restriction fragment length polymorphism (RFLP) variations to accumulate in human populations. Whether and how the variants of the HSV-1 that is ubiquitous worldwide spread to different human populations is not clear. In our previous study the geographically gradient distribution of the HSV-1 BgKL variant, which is a good marker for the BgKL:SaCFJM:SaGHM:SaD/EL:KpMS variant, suggested that BgKL dispersed geographically. Southern hybridization analyses showed that in BgKL the BglII cleavage site between the BglII K and small “Q/#13” fragments is lost, the SalI cleavage sites between the SalI J and C and between SalI F and J fragments are lost, and the SalI E fragment is abnormally large (SaEL variation). The RFLP and geographic distribution of one more HSV-1 RFLP variant, BgOL, were comparatively analyzed. The BglII cleavage site between the BglII O and Q/#13 fragments is lost in BgOL. BgOL clinical isolates were not associated with any of the SaCFJM, SaEL, SaGHM, or KpMS variations, whereas one-fourth of the non-BgOL:non-BgKL isolates was associated with SaCFJM and SaGHM, indicating that BgKL and BgOL are distant in terms of diversification. BgOL is distributed highly in the northeastern region and the southwestern island of Kyushu but is rare between the two regions in Japan, in a remarkable contrast to BgKL. These are the first epidemiologic data to show contrasting geographic distribution profiles of two HSV-1 variants and suggest the gradual dispersion and replacement of HSV-1 variants. PMID:17215348

  17. Geographical Education.

    ERIC Educational Resources Information Center

    Graves, Norman J.

    1981-01-01

    This annual review discusses works relevant to geographical education published in Europe, North America, Australia, Japan, and Africa. The journal is available from Edward Arnold (publishers) Ltd., 41 Bedford Square, London WC1B 3DQ England. (RM)

  18. Studies on Morphological and Physio-Ecological Variations of the Reniform Nematode, Rotylenchulus reniformis Linford and Oliveira, 1940 with an Emphasis on Differential Geographical Distribution of Amphimictic and Parthenogenetic Populations in Japan

    PubMed Central

    Nakasono, Kazutoshi

    2004-01-01

    The geographical distribution and polymorphism in morphological and biological characters of the reniform nematode, Rotylenchulus reniformis, in Japan were studied. The northern limit of habitat of this nematode was found on the 14 °C isothermal line of annual average-air temperature. Three morphologically different groups were ascertained which corresponded to three biological types based on male frequency. Incidence of males was consistent within populations and was not affected by environmental factors. Sexual attraction of males by females indicated reproductive isolation between the male-numerous type (MNT) and male-rare type (MRT) or male-absent type (MAT). Reproduction was amphimictic in the MNT and parthenogenetic in the MRT and MAT. Larval development in both MRT and MAT, but not that of MNT popula-tions, was inhibited at 34 °C. Differences in host preference were also observed among populations. PMID:19262821

  19. Addressing the unequal geographic distribution of specialist doctors in indonesia: the role of the private sector and effectiveness of current regulations.

    PubMed

    Meliala, Andreasta; Hort, Krishna; Trisnantoro, Laksono

    2013-04-01

    As in many countries, the geographic distribution of the health workforce in Indonesia is unequal, with a concentration in urban and more developed areas, and a scarcity in rural and remote areas. There is less information on the distribution of specialist doctors, yet inequalities in their distribution could compromise efforts to achieve universal coverage by 2014. This paper uses data from 2007 and 2008 to describe the geographic distribution of specialist doctors in Indonesia, and to examine two key factors that influence the distribution and are targets of current policies: sources of income for specialist doctors, and specialist doctor engagement in private practice. The data demonstrates large differences in the ratio of specialist doctors to population among the provinces of Indonesia, with higher ratios on the provinces of the islands of Java, and much lower ratios on the more remote provinces in eastern Indonesia. Between 65% and 80% of specialist doctors' income derives from private practice in non-state hospitals or private clinics. Despite regulations limiting practice locations to three, most specialists studied in a provincial capital city were working in more than three locations, with some working in up to 7 locations, and spending only a few hours per week in their government hospital practice. Our study demonstrates that the current regulatory policies and financial incentives have not been effective in addressing the maldistribution of specialist doctors in a context of a growing private sector and predominance of doctors' income from private sources. A broader and more integrated policy approach, including more innovative service delivery strategies for rural and remote areas, is recommended. PMID:23453314

  20. Malakal virus from Africa and Kimberley virus from Australia are geographic variants of a widely distributed ephemerovirus.

    PubMed

    Blasdell, Kim R; Voysey, Rhonda; Bulach, Dieter M; Trinidad, Lee; Tesh, Robert B; Boyle, David B; Walker, Peter J

    2012-11-10

    Kimberley virus (KIMV) is an arthropod-borne rhabdovirus that was isolated in 1973 and on several subsequent occasions from healthy cattle, mosquitoes (Culex annulirostris) and biting midges (Culicoides brevitarsis) in Australia. Malakal virus (MALV) is an antigenically related rhabdovirus isolated in 1963 from mosquitoes (Mansonia uniformis) in Sudan. We report here the complete genome sequences of KIMV (15442 nt) and MALV (15444 nt). The genomes have a similar organisation (3'-l-N-P-M-G-G(NS)-α1-α2-β-γ-L-t-5') to that of bovine ephemeral fever virus (BEFV). High levels of amino acid identity in each gene, similar gene expression profiles, clustering in phylogenetic analyses of the N, P, G and L proteins, and strong cross-neutralisation indicate that KIMV and MALV are geographic variants of the same ephemerovirus that, like BEFV, occurs in Africa, Asia and Australia. PMID:22925335

  1. A Review of the Current Geographic Distribution of and Debate Surrounding Electronic Cigarette Clean Air Regulations in the United States

    PubMed Central

    Kadowaki, Joy; Vuolo, Mike; Kelly, Brian C.

    2014-01-01

    In this article, we present the results of a systematic review of state, county, and municipal restrictions on the use of electronic cigarettes (e-cigarettes) in public spaces within the United States, alongside an overview of the current legal landscape. The lack of federal guidance leaves lower-level jurisdictions to debate the merits of restrictions on use in public spaces without sufficient scientific research. As we show through a geographic assessment of restrictions, this has resulted in an inconsistent patchwork of e-cigarette use bans across the United States of varying degrees of coverage. Bans have emerged over time in a manner that suggests a “bottom up” diffusion of e-cigarette clean air policies. Ultimately, the lack of clinical and scientific knowledge on the risks and potential harm reduction benefits has led to precautionary policymaking, which often lacks grounding in empirical evidence and results in spatially uneven diffusion of policy. PMID:25463920

  2. Seasonal distribution of fleas infesting rodents in various Egyptian eco-geographical areas and their susceptibility to malathion.

    PubMed

    Allam, Kamilia A M; Shalaby, Afaf A; Ashour, Mahmoud A

    2002-08-01

    The rodent population and their ectoparasites especially fleas, in various Egyptian eco-geographical areas were studied It was noticed that flea infestation varied according to rodent species and to the bioclimatic conditions. High flea indices were recorded in certain seasons of the year. The flea index was above one during spring in the southern of Nile Delta and semi-arid coastal areas, in summer in northern coastal areas and in autumn in southern of Nile Delta. Susceptibility tests were conducted using the WHO diagnostic dose of malathion (5%) on three populations of fleas collected from Qualyobia, Suez and Beni-Suef Governorates. The results indicated that malathion (5%) was very effective on fleas collected from Beni-Suef and Suez, but there was an evidence of increased tolerance among flea population collected from Qualyobia Governorate. PMID:12214918

  3. Is the nestedness of metazoan parasite assemblages of marine fishes from the southeastern Pacific coast a pattern associated with the geographical distributional range of the host?

    PubMed

    González, M T; Oliva, M E

    2009-04-01

    Nested structure is a pattern originally described in island biogeography to characterize how a set of species is distributed among a set of islands. In parasite communities, nestedness has been intensively studied among individual fish from a locality. However, nested patterns among parasite assemblages from different host populations (localities) have scarcely been investigated. We recorded the occurrence of parasites in 9 fish species widely distributed along the southeastern Pacific coast to determine whether the ecto- and endoparasite assemblages of marine fishes show a nested structure associated with host distributional range. Nestedness was tested using Brualdi-Sanderson index of discrepancy (BR); and 5 null models incorporated in a 'Nestedness' programme (Ulrich, 2006). The ecto- and endoparasite richness do not show similar patterns of latitudinal gradients among fish hosts, with 33-66% of analysed ectoparasite assemblages, and 25-75% of endoparasite assemblages showing nested structures through the host distributional range. For ectoparasites, species richness gradients and nested structure (when present) might be associated with decreased host densities or could reflect negative environmental conditions in the distributional border of the host species, whereas for endoparasites might be caused by geographical breaks of prey or changes in prey availability (intermediate hosts). The sampled extension of the distributional range of the host species, as well as the lack of specificity of some parasites, could influence the detection of nestedness. PMID:19195414

  4. Extended geographical distribution and host range of the cactus moth Cactoblastis cactorum (Lepidoptera Pyralidae)in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field exploration was conducted to confirm the southernmost distribution of Cactoblastis cactorum in Argentina. The distribution of the moth was extended to the south (40° 10´S) and west (66° 56´W). The native Opuntia penicilligera was recorded as a host for the first time. These findings should ...

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

    PubMed Central

    Zeng, Dingyuan

    2016-01-01

    Background 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. Objective and Methods 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. Results 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). Conclusions 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. PMID:27089387

  6. More about the geographical pattern of distribution of the genus Pseudouroplectes Lourenço, 1995 (Scorpiones: Buthidae) from Madagascar.

    PubMed

    Lourenço, Wilson R; Wilmé, Lucienne; Waeber, Patrick O

    2016-01-01

    The genus Pseudouroplectes Lourenço, 1995 (Buthidae) remains among the less speciose Malagasy genera and all the known species are extremely rare. A new species is described from the dry forests in the Tsingy formations of the National Park Bemaraha, extending the distribution of the genus further north. Once again, the single holotype specimen was obtained by extraction with the use of Berlese system. With the description of the new species, the distributional pattern of this genus is confirmed for dry forest formations from the south to the middle of the island; however, for the first time the group's distribution overlaps that of another micro-scorpion genus, Microcharmus Lourenço, 1995. The distribution patterns of the humicolous micro-scorpions endemic to Madagascar are considered to further explore the "Neogrosphus rule" as a possible explanation of global species distribution patterns in changing environments. PMID:26751250

  7. Geographical Distribution and Seasonal Indices of Chigger Mites on Small Mammals Collected on the East Coast of the Republic of Korea.

    PubMed

    Park, Gab-Man; Shin, Ho-Sung

    2016-04-01

    The geographical distributions and relative population densities of scrub typhus vector mites collected from small mammals were determined for 5 locations on the east coast of the Republic of Korea. Collection sites included Goseong, Gangneung, and Hoengseong in Gangwon province and Uljin and Yeongdeok in Gyeongbuk province. A total of 275 small mammals including members of Rodentia (rodents) and Soricomorpha (shrews, such as Crocidura lasiura ) belonging to 4 genera and 4 species were captured in the field from 2012 to 2013. Apodemus agrarius was collected most frequently (220, 80%), followed by C. lasiura (25, 9.1%), Mus musculus (15, 5.5%), and Myodes regulus (15, 5.5%). A total of 23,436 larval chigger mites (Family Trombiculidae) belonging to 3 genera and 8 species (Leptotrombidium pallidum, Leptotrombidium scutellare, Leptotrombidium palpale, Leptotrombidium orientale, Leptotrombidium zetum, Neotrombicula tamiyai, Neotrombicula japonica, and Euschoengastica koreaensis) were collected from the small mammals. The predominant chigger species collected during the spring and fall seasons from A. agrarius were L. pallidum (57.6%), L. palpale (14.5%), and L. scutellare (7.9%). Leptotrombidium scutellare was collected only along the southeastern coast at Yeongdeok, Gyeongbuk province. The geographical distribution of scrub typhus vectors and reservoir hosts are important aspects of understanding the epidemiology of the disease as well as the potential impacts of climate change and health risks. PMID:26653927

  8. Tityus perijanensis González-Sponga (Scorpiones, Buthidae): molecular assessment of its geographical distribution and venom lethality of Venezuelan populations.

    PubMed

    Borges, Adolfo; Rojas-Runjaic, Fernando J M

    2007-12-01

    An extensive field survey allowed us to expand the geographical distribution of the scorpion Tityus perijanensis in the Perijá range, western Zulia State, Venezuela, including areas where adult cases of severe scorpionism have been reported. 16S ribosomal RNA (rRNA) gene sequencing, DL(50) determination, and native PAGE suggest low genetic and venom proteomic divergence across the distribution range. The results also indicate phylogenetic divergence between T. perijanensis and T. discrepans, the species prevalent in northcentral Venezuela. T. perijanensis venom lethality (0.91-0.94 mg/kg) is comparable to that of the Brazilian T. serrulatus and ranks highest among toxic Venezuelan Tityus studied so far. The data indicate that the Perijá range should be included amongst the endemic areas of scorpionism of Venezuela and Colombia. PMID:17868753

  9. 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?

    USGS Publications Warehouse

    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.

  10. Contrasting Geographical Distributions as a Result of Thermal Tolerance and Long-Distance Dispersal in Two Allegedly Widespread Tropical Brown Algae

    PubMed Central

    Tronholm, Ana; Leliaert, Frederik; Sansón, Marta; Afonso-Carrillo, Julio; Tyberghein, Lennert; Verbruggen, Heroen; De Clerck, Olivier

    2012-01-01

    Background Many tropical marine macroalgae are reported from all three ocean basins, though these very wide distributions may simply be an artifact resulting from inadequate taxonomy that fails to take into account cryptic diversity. Alternatively, pantropical distributions challenge the belief of limited intrinsic dispersal capacity of marine seaweeds and the effectiveness of the north-south oriented continents as dispersal barriers. We aimed to re-assess the distribution of two allegedly circumtropical brown algae, Dictyota ciliolata and D. crenulata, and interpret the realized geographical range of the respective species in relation to their thermal tolerance and major tectonic and climatic events during the Cenozoic. Methodology/Principal Findings Species delimitation was based on 184 chloroplast encoded psbA sequences, using a Generalized Mixed Yule Coalescent method. Phylogenetic relationships were inferred by analyzing a six-gene dataset. Divergence times were estimated using relaxed molecular clock methods and published calibration data. Distribution ranges of the species were inferred from DNA-confirmed records, complemented with credible literature data and herbarium vouchers. Temperature tolerances of the species were determined by correlating distribution records with local SST values. We found considerable conflict between traditional and DNA-based species definitions. Dictyota crenulata consists of several pseudocryptic species, which have restricted distributions in the Atlantic Ocean and Pacific Central America. In contrast, the pantropical distribution of D. ciliolata is confirmed and linked to its significantly wider temperature tolerance. Conclusions/Significance Tectonically driven rearrangements of physical barriers left an unequivocal imprint on the current diversity patterns of marine macroalgae, as witnessed by the D. crenulata–complex. The nearly circumglobal tropical distribution of D. ciliolata, however, demonstrates that the north

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

    PubMed Central

    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. PMID:26943910

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

    PubMed

    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. PMID:26943910

  13. Residential mobility across local areas in the United States and the geographic distribution of the healthy population.

    PubMed

    Geronimus, Arline T; Bound, John; Ro, Annie

    2014-06-01

    Determining whether population dynamics provide competing explanations to place effects for observed geographic patterns of population health is critical for understanding health inequality. We focus on the working-age population-the period of adulthood when health disparities are greatest-and analyze detailed data on residential mobility collected for the first time in the 2000 U.S. census. Residential mobility over a five-year period is frequent and selective, with some variation by race and gender. Even so, we found little evidence that mobility biases cross-sectional snapshots of local population health. Areas undergoing large or rapid population growth or decline may be exceptions. Overall, place of residence is an important health indicator; yet, the frequency of residential mobility raises questions of interpretation from etiological or policy perspectives, complicating simple understandings that residential exposures alone explain the association between place and health. Psychosocial stressors related to contingencies of social identity associated with being black, urban, or poor in the United States may also have adverse health impacts that track with structural location even with movement across residential areas. PMID:24781651

  14. Xanthophyll cycle pool size and composition in several Cosmarium strains (Zygnematophyceae, Streptophyta) are related to their geographic distribution patterns.

    PubMed

    Stamenković, Marija; Bischof, Kai; Hanelt, Dieter

    2014-01-01

    The photosynthetic behaviour and composition of photosynthetic pigments of four Cosmarium strains collected from different geographic areas were examined under moderate and photoinhibitory white light by means of PAM fluorometry and high-performance liquid chromatography. Generally, all of the Cosmarium strains displayed the photosynthetic performance and the composition of xanthophyll cycle pigments corresponding to that of high-light adapted plants and algae, when grown under the standard laboratory conditions. However, photoinhibitory treatments provoked several strain- and species-specific characteristics despite the long-term cultivation in laboratory conditions. The typical arctic taxon, C. crenatum var. boldtianum, displayed an incomplete violaxanthin cycle yielding an accumulation of antheraxanthin during high light stress, which is considered as an adaptation to occasional high irradiances in the polar zone due to the albedo. So far, the violaxanthin/antheraxanthin turnover was known only in some prasinophycean algae. Antheraxanthin actively participated in the heat dissipation from PSII centres in C. crenatum, as concluded from a significant positive correlation between non-photochemical quenching (NPQ) and the quantity of antheraxanthin. In contrast, all the other Cosmarium strains displayed a complete violaxanthin de-epoxidase action during the high light treatments, as judged from the relatively high production of zeaxanthin which participated in thermal dissipation of excess energy. PMID:24334196

  15. Geographically distributed classification of surface water chemical parameters influencing fate and behavior of nanoparticles and colloid facilitated contaminant transport.

    PubMed

    Hammes, Julia; Gallego-Urrea, Julián A; Hassellöv, Martin

    2013-09-15

    The current production and use of nanomaterials in consumer products have increased the concern about the possibility that these enter the rivers during their entire life cycle. Further, many aquatic contaminants undergo partitioning to the ubiquitous aquatic colloids. Here is presented the development of a set of European water types for environmental risk assessment of chemicals transported as nanovectors as is the case of environmental fate of manufactured nanoparticles and colloid-bound contaminants. A compilation of river quality geochemical data with information about multi-element composition for near 800 rivers in Europe was used to perform a principal component analysis (PCA) and define 6 contrasting water classes. With the aid of geographical information system algorithms, it was possible to analyse how the different sampling locations were predominantly represented within each European water framework directive drainage basin. These water classes and their associated Debye-Hückel parameter are determining factors to evaluate the large scale fate and behaviour of nanomaterials and other colloid-transported pollutants in the European aquatic environment. PMID:23863373

  16. [Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: a review].

    PubMed

    Huang, Xiang-Hua; Wang, Jian; Zeng, Hong-Da; Chen, Guang-Shui; Zhong, Xian-Fang

    2013-06-01

    Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality. PMID:24066568

  17. Genetic markers reveal a gradient of hybridization between cape hakes (Merluccius capensis and Merluccius paradoxus) in their sympatric geographic distribution

    NASA Astrophysics Data System (ADS)

    Miralles, Laura; Machado-Schiaffino, Gonzalo; Garcia-Vazquez, Eva

    2014-02-01

    The cape hakes Merluccius capensis and Merluccius paradoxus are important fishing resources for African countries such as Namibia and South Africa. In this study we have genetically analyzed adult samples from the overlapping distribution of these species. Eight microsatellite loci, the nuclear 5S rDNA locus and the Cytochrome Oxidase subunit I (COI) gene were employed as molecular markers. A North-South gradient of interspecific hybridization was found, with discordant mitochondrial and nuclear genotypes at the northernmost edge of M. paradoxus distribution. These results suggest intense introgression in North Benguela off the Namibian coast. Independent hake stock assessment is recommended in this region for sustainable management of this valuable resource.

  18. Large-scale analysis of the prevalence and geographic distribution of HIV-1 non-B variants in the United States.

    PubMed

    Pyne, Michael T; Hackett, John; Holzmayer, Vera; Hillyard, David R

    2013-08-01

    The genetic diversity of human immunodeficiency virus type 1 (HIV-1) has significant implications for diagnosis, vaccine development, and clinical management of patients. Although HIV-1 subtype B is predominant in the United States, factors such as global travel, immigration, and military deployment have the potential to increase the proportion of non-subtype B infections. Limited data are available on the prevalence and distribution of non-B HIV-1 strains in the United States. We sought to retrospectively examine the prevalence, geographic distribution, diversity, and temporal trends of HIV-1 non-B infections in samples obtained by ARUP Laboratories, a national reference laboratory, from all regions of the United States. HIV-1 pol sequences from 24,386 specimens collected from 46 states between 2004 and September 2011 for drug resistance genotyping were analyzed using the REGA HIV-1 Subtyping Tool, version 2.0. Sequences refractory to subtype determination or reported as non-subtype B by this tool were analyzed by PHYLIP version 3.5 and Simplot version 3.5.1. Non-subtype B strains accounted for 3.27% (798/24,386) of specimens. The 798 non-B specimens were received from 37 states and included 5 subtypes, 23 different circulating recombinant forms (CRFs), and 39 unique recombinant forms (URFs). The non-subtype B prevalence varied from 0% in 2004 (0/54) to 4.12% in 2011 (201/4,884). This large-scale analysis reveals that the diversity of HIV-1 in the United States is high, with multiple subtypes, CRFs, and URFs circulating. Moreover, the geographic distribution of non-B variants is widespread. Data from HIV-1 drug resistance testing have the potential to significantly enhance the surveillance of HIV-1 variants in the United States. PMID:23761148

  19. Geographical factors affecting bed net ownership, a tool for the elimination of Anopheles-transmitted lymphatic filariasis in hard-to-reach communities.

    PubMed

    Stanton, Michelle C; Bockarie, Moses J; Kelly-Hope, Louise A

    2013-01-01

    Vector control, including the use of bed nets, is recommended as a possible strategy for eliminating lymphatic filariasis (LF) in post-conflict countries such as the Democratic Republic of Congo (DRC). This study examined the geographical factors that influence bed net ownership in DRC in order to identify hard-to-reach communities that need to be better targeted. In particular, urban/rural differences and the influence of population density, proximity to cities and health facilities, plus access to major transport networks were investigated. Demographic and Health Survey geo-referenced cluster level data were used to map bed net coverage (proportion of households with at least one of any type of bed net or at least one insecticide-treated net (ITN)), and ITN density (ITNs per person) for 260 clusters. Bivariate and multiple logistic or Poisson regression analyses were used to determine significant relationships. Overall, bed net (30%) and ITN (9%) coverage were very low with significant differences found between urban and rural clusters. In rural clusters, ITN coverage/density was positively correlated with population density (r = 0.25, 0.27 respectively, p<0.01), and negatively with the distance to the two largest cities, Kinshasa or Lubumbashi (r = -0.28, -0.30 respectively, p<0.0001). Further, ownership was significantly negatively correlated with distance to primary national roads and railways (all three measures), distance to main rivers (any bed net only) and distance to the nearest health facility (ITNs only). Logistic and Poisson regression models fitted to the rural cluster data indicated that, after controlling for measured covariates, ownership levels in the Bas-Congo province close to Kinshasa were much larger than that of other provinces. This was most noticeable when considering ITN coverage (odds ratio: 5.3, 95% CI: 3.67-7.70). This analysis provides key insights into the barriers of bed net ownership, which will help inform both LF and

  20. Geographical Factors Affecting Bed Net Ownership, a Tool for the Elimination of Anopheles-Transmitted Lymphatic Filariasis in Hard-to-Reach Communities

    PubMed Central

    Stanton, Michelle C.; Bockarie, Moses J.; Kelly-Hope, Louise A.

    2013-01-01

    Vector control, including the use of bed nets, is recommended as a possible strategy for eliminating lymphatic filariasis (LF) in post-conflict countries such as the Democratic Republic of Congo (DRC). This study examined the geographical factors that influence bed net ownership in DRC in order to identify hard-to-reach communities that need to be better targeted. In particular, urban/rural differences and the influence of population density, proximity to cities and health facilities, plus access to major transport networks were investigated. Demographic and Health Survey geo-referenced cluster level data were used to map bed net coverage (proportion of households with at least one of any type of bed net or at least one insecticide-treated net (ITN)), and ITN density (ITNs per person) for 260 clusters. Bivariate and multiple logistic or Poisson regression analyses were used to determine significant relationships. Overall, bed net (30%) and ITN (9%) coverage were very low with significant differences found between urban and rural clusters. In rural clusters, ITN coverage/density was positively correlated with population density (r = 0.25, 0.27 respectively, p<0.01), and negatively with the distance to the two largest cities, Kinshasa or Lubumbashi (r = −0.28, −0.30 respectively, p<0.0001). Further, ownership was significantly negatively correlated with distance to primary national roads and railways (all three measures), distance to main rivers (any bed net only) and distance to the nearest health facility (ITNs only). Logistic and Poisson regression models fitted to the rural cluster data indicated that, after controlling for measured covariates, ownership levels in the Bas-Congo province close to Kinshasa were much larger than that of other provinces. This was most noticeable when considering ITN coverage (odds ratio: 5.3, 95% CI: 3.67–7.70). This analysis provides key insights into the barriers of bed net ownership, which will help inform both LF

  1. Mapping the geographic distribution of canopy species communities in lowland Amazon rainforest with CAO-AToMS (Invited)

    NASA Astrophysics Data System (ADS)

    Feret, J.; Asner, G. P.

    2013-12-01

    Mapping regional canopy diversity will greatly advance our understanding as well as the conservation of tropical rainforests. Changes in species composition across space and time are particularly important to understand the influence of climate, human activity and environmental factors on these ecosystems, but to date such monitoring is extremely challenging and is facing a scale gap between small-scale, highly detailed field studies and large-scale, low-resolution satellite observations. Advances were recently made in the field of spectroscopic imagery for the estimation of canopy alpha-diversity, and an original approach based on the segmentation of the spectral space proved its ability to estimate Shannon diversity index with unprecedented accuracy. We adapted this method in order to estimate spectral dissimilarity across landscape as a proxy for changes in species composition. We applied this approach and mapped species composition over four sites located in lowland rainforest of Peruvian Amazon. This study was based on spectroscopic imagery acquired using the Carnegie Airborne Observatory (CAO) Airborne Taxonomic Mapping System (AToMS), operating a unique sensor combining the fine spectral and spatial resolution required for such task. We obtained accurate estimation of Bray-Curtis distance between pairs of plots, which is the most commonly used metric to estimate dissimilarity in species composition (n=497 pairs, r=0.63). The maps of species composition were then compared to topo-hydrographic properties. Our results indicated a strong shift in species composition and community diversity between floodplain and terra firme terrain conditions as well as a significantly higher diversity of species communities within Amazonian floodplains. These results pave the way for global mapping of tropical canopy diversity at fine geographic resolution.

  2. Geographical distribution of human Schistosoma japonicum infection in The Philippines: tools to support disease control and further elimination.

    PubMed

    Soares Magalhães, Ricardo J; Salamat, Maria Sonia; Leonardo, Lydia; Gray, Darren J; Carabin, Hélène; Halton, Kate; McManus, Donald P; Williams, Gail M; Rivera, Pilarita; Saniel, Ofelia; Hernandez, Leda; Yakob, Laith; McGarvey, Stephen; Clements, Archie

    2014-11-01

    Schistosoma japonicum infection is believed to be endemic in 28 of the 80 provinces of The Philippines and the most recent data on schistosomiasis prevalence have shown considerable variability between provinces. In order to increase the efficient allocation of parasitic disease control resources in the country, we aimed to describe the small-scale spatial variation in S. japonicum prevalence across The Philippines, quantify the role of the physical environment in driving the spatial variation of S. japonicum, and develop a predictive risk map of S. japonicum infection. Data on S. japonicum infection from 35,754 individuals across the country were geo-located at the barangay level and included in the analysis. The analysis was then stratified geographically for the regions of Luzon, the Visayas and Mindanao. Zero-inflated binomial Bayesian geostatistical models of S. japonicum prevalence were developed and diagnostic uncertainty was incorporated. Results of the analysis show that in the three regions, males and individuals aged ⩾20years had significantly higher prevalence of S. japonicum compared with females and children <5years. The role of the environmental variables differed between regions of The Philippines. Schistosoma japonicum infection was widespread in the Visayas whereas it was much more focal in Luzon and Mindanao. This analysis revealed significant spatial variation in the prevalence of S. japonicum infection in The Philippines. This suggests that a spatially targeted approach to schistosomiasis interventions, including mass drug administration, is warranted. When financially possible, additional schistosomiasis surveys should be prioritised for areas identified to be at high risk but which were under-represented in our dataset. PMID:25128879

  3. Geographical distribution of human Schistosoma japonicum infection in The Philippines: tools to support disease control and further elimination

    PubMed Central

    Magalhães, Ricardo J Soares; Salamat, Maria Sonia; Leonardo, Lydia; Gray, Darren J; Carabin, Hélène; Halton, Kate; McManus, Donald P; Williams, Gail M; Rivera, Pilarita; Saniel, Ofelia; Hernandez, Leda; Yakob, Laith; McGarvey, Stephen; Clements, Archie

    2015-01-01

    Schistosoma japonicum infection is believed to be endemic in 28 of the 80 provinces of The Philippines and the most recent data on schistosomiasis prevalence have shown considerable variability between provinces. In order to increase the efficient allocation of parasitic disease control resources in the country, we aimed to describe the small-scale spatial variation in S. japonicum prevalence across The Philippines, quantify the role of the physical environment in driving the spatial variation of S. japonicum, and develop a predictive risk map of S. japonicum infection. Data on S. japonicum infection from 35,754 individuals across the country were geolocated at the barangay level and included in the analysis. The analysis was then stratified geographically for the regions of Luzon, the Visayas and Mindanao. Zero-inflated binomial Bayesian geostatistical models of S. japonicum prevalence were developed and diagnostic uncertainty was incorporated. Results of the analysis show that in the three regions, males and individuals aged ≥ 20 years had significantly higher prevalence of S. japonicum compared with females and children < 5 years. The role of the environmental variables differed between regions of The Philippines. Schistosoma japonicum infection was widespread in the Visayas whereas it was much more focal in Luzon and Mindanao. This analysis revealed significant spatial variation in the prevalence of S. japonicum infection in The Philippines. This suggests that a spatially targeted approach to schistosomiasis interventions, including mass drug administration, is warranted. When financially possible, additional schistosomiasis surveys should be prioritized for areas identified to be at high risk but which were under-represented in our dataset. PMID:25128879

  4. Baseline assessment of prevalence and geographical distribution of HPV types in Chile using self-collected vaginal samples

    PubMed Central

    Ferreccio, Catterina; Corvalán, Alejandro; Margozzini, Paula; Viviani, Paola; González, Claudia; Aguilera, Ximena; Gravitt, Patti E

    2008-01-01

    Background Chile has broad variations in weather, economics and population from the far desert north (Region 1) to the cold, icy south (Region 12). A home-based self-collected vaginal sampling was nested in the 2003 Chilean population-based health survey in order to explore the possibility of a type-specific geographical variation for human papillomavirus Methods The population was a national probability sample of people 17 years of age and over. Consenting women provided self-collected cervicovaginal swabs in universal collection media (UCM). DNA was extracted and typed to 37 HPV genotypes using PGMY consensus PCR and line blot assay. Weighted prevalence rates and adjusted OR were calculated. Results Of the 1,883 women participating in the health survey, 1,219 (64.7%) provided a cervicovaginal sample and in 1,110 (56.2% of participants and 66.5% of those eligible) the samples were adequate for analysis. Refusal rate was 16.9%. HPV prevalence was 29.2% (15.1% high-risk HPV and 14.1% low-risk HPV). Predominant high-risk types were HPV 16, 52, 51, 56 and 58. Predominant low-risk HPVs were HPV 84, CP6108, 62, 53 and 61. High-risk and low-risk HPV rates were inversely correlated between the regions. High-risk HPV prevalence was highest among the youngest women, whereas low-risk HPV increased slightly with age. Conclusion Self-obtained vaginal sampling is adequate for monitoring HPV in the community, for identifying high-risk areas, and for surveying the long term impact of interventions. PMID:18304362

  5. Allelic Diversity and Geographical Distribution of the Gene Encoding Plasmodium falciparum Merozoite Surface Protein-3 in Thailand

    PubMed Central

    Sawaswong, Vorthon; Simpalipan, Phumin; Siripoon, Napaporn; Harnyuttanakorn, Pongchai; Pattaradilokrat, Sittiporn

    2015-01-01

    Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles coexisted, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines. PMID:25925176

  6. A missing geographic link in the distribution of the genus Echinotriton (Caudata: Salamandridae) with description of a new species from southern China.

    PubMed

    Hou, Mian; Wu, Yunke; Yang, Kelin; Zheng, Sheng; Yuan, Zhiyong; Li, Pipeng

    2014-01-01

    Disjunct geographic distribution of a species or a group of species is the product of long-term interaction between organisms and the environment. Filling the distributional gap by discovery of a new population or a species has significant biogeographic implications, because it suggests a much wider past distribution and provides evidence for the route of range expansion/contraction. The salamandrid genus Echinotriton (commonly known as spiny salamanders, spiny newts, or crocodile newts) has two species that are restricted to two widely separated areas, one in eastern Zhejiang province, China and the other in the Ryukyu Archipelago of Japan. It has been hypothesized that Echinotriton was once continuously distributed between the two areas through a historical land bridge that connected mainland China, Taiwan, and the archipelago. Finding fossils or relic populations along the postulated distribution are strong evidence for the hypothesis. Hundred-twenty-two years after the description of E. andersoni and eight-one years after that of E. chinhaiensis, we discover a third species of Echinotriton in southern China, which fills the distributional gap of the former two species. Species status of the new species is confirmed through molecular phylogenetic analysis and morphological comparison. Mitochondrial DNA indicates that the new species is sister to E. chinhaiensis, while nuclear DNA does not support this relationship. The new species has a very large quadrate projection, a single line of lateral warts pierced by distal rib extremities, normally developed 5th toes, and conical skin tubercles. Our discovery supports the hypothesis that there was a continuous distribution of Echinotriton from eastern coastal China to the Ryukyu Archipelago. We suggest that other species of this genus may also be found in Taiwan. Due to the rarity of this new species, we urge all hobbyists to refrain themselves from collecting this salamander or leaking locality information if

  7. A rice diversity panel evaluated for genetic and agro-morphological diversity between subpopulations and its geographic distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A diverse collection of 410 purified rice accessions originating from 77 countries was developed by identifying a representative plant from each accession. These accessions were fingerprinted with 36 SSR markers distributed throughout the genome and evaluated for 18 agro-morphological traits. A tota...

  8. Geographic variation in the effects of disturbance, fungi, insects, and resilience on the abundance of a globally distributed plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aim: To assess the effects of disturbance, fungi, insects, and resilience on the abundance of a globally distributed ruderal, Centaurea solstitialis, in two regions with contrasting conditions within both native and non-native ranges. Location: The Caucasus (Georgia and Armenia) and south-western...

  9. Interspecific geographic distribution and variation of two bumble bee pathogens, Nosema bombi and Crithidia bombi, in United States populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several bumble bee (Bombus) species in North America have undergone range reductions and rapid declines in relative abundance. Pathogens have been suggested as causal factors, however, baseline data on pathogen distributions in a large number of bumble bee species have not been available to rigorous...

  10. Geographic distribution of Gryllotalpa stepposa in south-eastern Europe, with first records for Romania, Hungary and Serbia (Insecta, Orthoptera, Gryllotalpidae)

    PubMed Central

    Iorgu, Ionuț Ștefan; Iorgu, Elena Iulia; Puskás, Gellért; Ivković, Slobodan; Borisov, Simeon; Gavril, Viorel Dumitru; Chobanov, Dragan Petrov

    2016-01-01

    Abstract Described from the steppe zones north of the Black Sea, Caucasus, and central Asia, Gryllotalpa stepposa Zhantiev was recently recorded from a few localities in Greece, R. Macedonia, and Bulgaria. In May 2015, several specimens were collected from Ivrinezu Mare in Romania, which suggested a continuous distribution area of the species, stretching from the central Balkans to central Asia. Thus, to reveal its actual range of occurrence, a survey of several Orthoptera collections became mandatory and, as expected, a large number of misidentified specimens of Gryllotalpa stepposa were discovered, providing new data on the species distribution in south-eastern Europe, including also the first records of this mole cricket in Serbia and Hungary. Here a full locality list is presented of this species west of Ukraine and Moldova and the current geographic distribution of the genus Gryllotalpa in the Balkans is revised. A key for distinguishing the mole crickets in south-eastern Europe and a distribution map for this region are presented. PMID:27551213

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:26940060

  13. Factors Affecting the Distribution Pattern of Wild Plants with Extremely Small Populations in Hainan Island, China

    PubMed Central

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012–2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  14. Factors affecting the distribution pattern of wild plants with extremely small populations in Hainan Island, China.

    PubMed

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012-2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  15. Genetic differentiation in the genus Lithops L. (Ruschioideae, Aizoaceae) reveals a high level of convergent evolution and reflects geographic distribution.

    PubMed

    Kellner, A; Ritz, C M; Schlittenhardt, P; Hellwig, F H

    2011-03-01

    Southern Africa is one of the hot spots for plant biodiversity, with ca. 80% of species endemic to this area. Rapid and recent radiations in Southern African plant genera were triggered by fine-scale differences in climate, topography and geology. The genus Lithops (Ruschioideae, Aizoaceae) contains 37 species and is widely distributed in Southern Africa. Species delimitation within the genus is challenging because the limited number of morphological characters in these reduced succulents varies intensely between populations, presumably as adaptations to local geological environments. We analysed phylogenetic relationships within Lithops using non-coding chloroplast DNA (trnS-trnG intergenic spacer), nuclear ribosomal internal transcribed spacer (nrITS) sequences and AFLP data. Genetic variability of the sequence data was very low, but AFLP data detected nine clades within Lithops that do not fit current morphology-based taxonomy. Two of these clades are separated by their distribution on the northern and eastern border of the distribution area, and four clades are found in the Gariep Centre in the estuary of the Orange River. Morphological similarities, especially colour of leaves, evolved repeatedly within the clades, thus we hypothesise that closely related species became adapted to different soil types in a mosaic-like geological environment. One-third of the species are found in the Gariep Centre, characterised by extremely diverse edaphic habitats. PMID:21309984

  16. A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera)

    PubMed Central

    Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A.; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

    2015-01-01

    Abstract Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT’s Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF). PMID:26798295

  17. A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera).

    PubMed

    Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

    2015-01-01

    Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT's Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF). PMID:26798295

  18. Genotyping-by-sequencing approach indicates geographic distance as the main factor affecting genetic structure and gene flow in Brazilian populations of Grapholita molesta (Lepidoptera, Tortricidae).

    PubMed

    Silva-Brandão, Karina Lucas; Silva, Oscar Arnaldo Batista Neto E; Brandão, Marcelo Mendes; Omoto, Celso; Sperling, Felix A H

    2015-06-01

    The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G. molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant ΦST value = 0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G. molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation. PMID:26029261

  19. Genotyping-by-sequencing approach indicates geographic distance as the main factor affecting genetic structure and gene flow in Brazilian populations of Grapholita molesta (Lepidoptera, Tortricidae)

    PubMed Central

    Silva-Brandão, Karina Lucas; Silva, Oscar Arnaldo Batista Neto e; Brandão, Marcelo Mendes; Omoto, Celso; Sperling, Felix A H

    2015-01-01

    The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G. molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant ΦST value = 0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G. molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation. PMID:26029261

  20. Contribution for Iron Vapor and Radiation Distribution Affected by Current Frequency of Pulsed Arc

    NASA Astrophysics Data System (ADS)

    Shimokura, Takuya; Mori, Yusuke; Iwao, Toru; Yumoto, Motoshige

    Pulsed GTA welding has been used for improvement of stability, weld speed, and heat input control. However, the temperature and radiation power of the pulsed arc have not been elucidated. Furthermore, arc contamination by metal vapor changes the arc characteristics, e.g. by increasing radiation power. In this case, the metal vapor in pulsed GTA welding changes the distribution of temperature and radiation power as a function of time. This paper presents the relation between metal vapor and radiation power at different pulse frequencies. We calculate the Fe vapor distribution of the pulsed current. Results show that the Fe vapor is transported at fast arc velocity during the peak current period. During the base current period, the Fe vapor concentration is low and distribution is diffuse. The transition of Fe vapor distribution does not follow the pulsed current; the radiation power density distribution differs for high frequencies and low frequencies. In addition, the Fe vapor and radiation distribution are affected by the pulsed arc current frequency.

  1. TITER AND PRODUCT AFFECTS THE DISTRIBUTION OF GENE EXPRESSION AFTER INTRAPUTAMINAL CONVECTION-ENHANCED DELIVERY

    PubMed Central

    Emborg, Marina E.; Hurley, Samuel A.; Joers, Valerie; Tromp, Do P.M.; Swanson, Christine R.; Ohshima-Hosoyama, Sachiko; Bondarenko, Viktorya; Cummisford, Kyle; Sonnemans, Marc; Hermening, Stephan; Blits, Bas; Alexander, Andrew L.

    2014-01-01

    Background Efficacy and safety of intracerebral gene therapy for brain disorders, like Parkinson’s disease, depends on appropriate distribution of gene expression. Objectives To assess if the distribution of gene expression is affected by vector titer and protein type. Methods Four adult macaque monkeys seronegative for adeno-associated virus 5 (AAV5) received in the right and left ventral postcommisural putamen 30μl inoculation of a high or low titer suspension of AAV5 encoding glial derived neurotrophic factor (GDNF) or green fluorescent protein (GFP). Inoculations were performed using convection enhanced delivery and intraoperative MRI (IMRI). Results IMRI confirmed targeting and infusion cloud irradiating from the catheter tip into surrounding area. Postmortem analysis six weeks after surgery revealed GFP and GDNF expression ipsilateral to the injection side that had a titer-dependent distribution. GFP and GDNF expression was also observed in fibers in the Substantia Nigra (SN) pars reticulata (pr), demonstrating anterograde transport. Few GFP-positive neurons were present in the SN pars compacta (pc), possibly by direct retrograde transport of the vector. GDNF was present in many SNpc and SNpr neurons. Conclusions After controlling for target and infusate volume, intracerebral distribution of gene product is affected by vector titer and product biology. PMID:24943657

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

    PubMed

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

    2014-01-01

    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.  PMID:25544468

  3. TDM/FM/FDMA - A modulation technique for multiple-beam satellites which precludes cochannel interference and allows non-uniform geographic distribution of user channels

    NASA Astrophysics Data System (ADS)

    Springett, J. C.

    The technique outlined in this paper is intended to eliminate the problems of cochannel interference and uniform geographic distribution of user channels which arise in conventional designs for a multiple spot beam communication satellite to serve mobile telephony users across the CONUS. By time multiplexing FM/FDMA signal ensembles so that only those beams operating on distinct frequency subbands are allowed to transmit concurrently, cochannel interference arising from simultaneous frequency subband reuse is precluded. Thus, time disjoint frequency reuse is accomplished over a repetitive sequence of fixed time slots. By assigning different size subbands to each time slot, a market of nonuniform users can be accommodated. The technique results in a greatly simplified antenna feed system design for the satellite, at a cost of imposing the need for time slot synchronization on the mobile FM receivers whose ability for rejecting adjacent channel interference is somewhat diminished.

  4. Distribution of Potential Hydrothermally Altered Rocks in Central Colorado Derived From Landsat Thematic Mapper Data: A Geographic Information System Data Set

    USGS Publications Warehouse

    Knepper, Daniel H.

    2010-01-01

    As part of the Central Colorado Mineral Resource Assessment Project, the digital image data for four Landsat Thematic Mapper scenes covering central Colorado between Wyoming and New Mexico were acquired and band ratios were calculated after masking pixels dominated by vegetation, snow, and terrain shadows. Ratio values were visually enhanced by contrast stretching, revealing only those areas with strong responses (high ratio values). A color-ratio composite mosaic was prepared for the four scenes so that the distribution of potentially hydrothermally altered rocks could be visually evaluated. To provide a more useful input to a Geographic Information System-based mineral resource assessment, the information contained in the color-ratio composite raster image mosaic was converted to vector-based polygons after thresholding to isolate the strongest ratio responses and spatial filtering to reduce vector complexity and isolate the largest occurrences of potentially hydrothermally altered rocks.

  5. Frequency and Geographic Distribution of gyrA and gyrB Mutations Associated with Fluoroquinolone Resistance in Clinical Mycobacterium Tuberculosis Isolates: A Systematic Review

    PubMed Central

    Avalos, Elisea; Catanzaro, Donald; Catanzaro, Antonino; Ganiats, Theodore; Brodine, Stephanie; Alcaraz, John; Rodwell, Timothy

    2015-01-01

    Background The detection of mutations in the gyrA and gyrB genes in the Mycobacterium tuberculosis genome that have been demonstrated to confer phenotypic resistance to fluoroquinolones is the most promising technology for rapid diagnosis of fluoroquinolone resistance. Methods In order to characterize the diversity and frequency of gyrA and gyrB mutations and to describe the global distribution of these mutations, we conducted a systematic review, from May 1996 to April 2013, of all published studies evaluating Mycobacterium tuberculosis mutations associated with resistance to fluoroquinolones. The overall goal of the study was to determine the potential utility and reliability of these mutations as diagnostic markers to detect phenotypic fluoroquinolone resistance in Mycobacterium tuberculosis and to describe their geographic distribution. Results Forty-six studies, covering four continents and 18 countries, provided mutation data for 3,846 unique clinical isolates with phenotypic resistance profiles to fluoroquinolones. The gyrA mutations occurring most frequently in fluoroquinolone-resistant isolates, ranged from 21–32% for D94G and 13–20% for A90V, by drug. Eighty seven percent of all strains that were phenotypically resistant to moxifloxacin and 83% of ofloxacin resistant isolates contained mutations in gyrA. Additionally we found that 83% and 80% of moxifloxacin and ofloxacin resistant strains respectively, were observed to have mutations in the gyrA codons interrogated by the existing MTBDRsl line probe assay. In China and Russia, 83% and 84% of fluoroquinolone resistant strains respectively, were observed to have gyrA mutations in the gene regions covered by the MTBDRsl assay. Conclusions Molecular diagnostics, specifically the Genotype MTBDRsl assay, focusing on codons 88–94 should have moderate to high sensitivity in most countries. While we did observe geographic differences in the frequencies of single gyrA mutations across countries, molecular

  6. The Distribution and Abundance of an Island Population of Koalas (Phascolarctos cinereus) in the Far North of Their Geographic Range

    PubMed Central

    McGregor, Denise C.; Kerr, Sarah E.; Krockenberger, Andrew K.

    2013-01-01

    Koalas are an iconic species of charismatic megafauna, of substantial social and conservation significance. They are widely distributed, often at low densities, and individuals can be difficult to detect, making population surveys challenging and costly. Consequently, koala population estimates have been limited and the results inconsistent. The aims of this study were to estimate the distribution, relative abundance and population size of the koalas on Magnetic Island, far north Queensland. Population densities were estimated in 18 different vegetation types present on the island using a Fecal Standing Crop Method. Koala density ranged from 0.404 ha−1, recorded in forest red gum and bloodwood woodland, to absence from eight of the vegetation types surveyed. The second highest density of 0.297 koalas ha−1 was recorded in mixed eucalypt woodland, which covers 45% of the island. The total abundance of koalas on Magnetic Island, not including those present in urban areas, was estimated at 825±175 (SEM). The large variation in koala density across vegetation types reinforces the need for sampling stratification when calculating abundance over large areas, as uniformity of habitat quality cannot be assumed. In this context, koala populations also occur in low densities in areas generally regarded as poor quality koala habitat. These results highlight the importance of protecting vegetation communities not traditionally considered to have high conservation value to koalas, as these habitats may be essential for maintaining viable, widespread, low-density populations. The results from this study provide a baseline to assess future trends in koala distribution, density and abundance on Magnetic Island. PMID:23527258

  7. Geographical Distribution of MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in China: Findings from 15357 Adults of Han Nationality

    PubMed Central

    Yang, Boyi; Liu, Yuyan; Li, Yongfang; Fan, Shujun; Zhi, Xueyuan; Lu, Xiangxiang; Wang, Da; Zheng, Quanmei; Wang, Yinuo; Wang, Yanxun; Sun, Guifan

    2013-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms are important genetic determinants for homocysteine (Hcy) levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. Methodologies 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5′-nuclease assay. Principal Findings The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively) in Hainan (southern) to the highest values (63.1% and 40.8%, respectively) in Shandong (northern). For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively) in Shandong to high values (25.7% and 6.7%, respectively) in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively) in Shandong to higher values (29.2% and 8.6%, respectively) in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. Conclusions This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be useful for

  8. Genetic Differentiation in the Stingless Bee, Scaptotrigona xanthotricha Moure, 1950 (Apidae, Meliponini): a Species with Wide Geographic Distribution in the Atlantic Rainforest.

    PubMed

    Duarte, Olívia M P; Gaiotto, Fernanda A; Costa, Marco A

    2014-05-14

    Stingless bees are important pollinators that are severely threatened by anthropic interference, resulting in a strong population decline. Scaptotrigona xanthotricha has a wide distribution in the Atlantic Rainforest, ranging from the northeastern state of Bahia to Santa Catarina in southern Brazil. To understand the genetic structure of S. xanthotricha, 12 species-specific microsatellite loci were analyzed in 42 colonies sampled throughout the species range. The results indicated 5 distinct clusters throughout the sampled area with high rates of genetic diversity, and the greatest diversity was found in southern Bahia. Greater differentiation was observed between samples from the extremes of the distribution, with an F ST value of 0.189 between cluster 1 and 5. The genetic differentiation analysis for all loci had an F ST value of 0.113, a result that is consistent with the analysis of molecular variance, which revealed 7.72% of the variation occurring between groups. The Mantel correlation between a genetic differentiation matrix and a geographic distance matrix (r = 0.184, P = 0.043) indicated a tendency toward increased differentiation with increased distance. This study revealed the profile of differentiation and distribution of genetic diversity in this species and indicates parameters that should be considered in future taxonomic revisions and activities for its management and conservation. PMID:24829365

  9. Thermal Niches of Two Invasive Genotypes of the Wheat Curl Mite Aceria tosichella: Congruence between Physiological and Geographical Distribution Data

    PubMed Central

    2016-01-01

    The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide. It is also a complex of well-defined genetic lineages with divergent physiological traits, which has not been accounted for in applied contexts. The aims of the study were to model the thermal niches of the two most pestiferous WCM lineages, designated MT-1 and MT-8, and to assess the extent to which temperature determines the distribution of these lineages. WCM population dynamics were modeled based on thermal niche data from March to November on the area of Poland (>311,000 km2). The most suitable regions for population development were predicted and compared to empirical field abundance data. Congruence between modeled parameters and field data for mite presence were observed for both WCM lineages although congruence between modeled thermal suitability and mite field abundance was observed only for MT-8. Thermal niche data for MT-1 and MT-8 provide biological insights and aid monitoring and management of WCM and the plant viruses it vectors. The presented models accurately estimate distributions of WCM and can be incorporated into management strategies for both current and predicted climate scenarios. PMID:27123590

  10. Phylogenetic Diversity and Environment-Specific Distributions of Glycosyl Hydrolase Family 10 Xylanases in Geographically Distant Soils

    PubMed Central

    Luo, Huiying; Wang, Yaru; Huang, Huoqing; Shi, Pengjun; Yang, Peilong; Zhang, Zhifang; Yao, Bin

    2012-01-01

    Background Xylan is one of the most abundant biopolymers on Earth. Its degradation is mediated primarily by microbial xylanase in nature. To explore the diversity and distribution patterns of xylanase genes in soils, samples of five soil types with different physicochemical characters were analyzed. Methodology/Principal Findings Partial xylanase genes of glycoside hydrolase (GH) family 10 were recovered following direct DNA extraction from soil, PCR amplification and cloning. Combined with our previous study, a total of 1084 gene fragments were obtained, representing 366 OTUs. More than half of the OTUs were novel (identities of <65% with known xylanases) and had no close relatives based on phylogenetic analyses. Xylanase genes from all the soil environments were mainly distributed in Bacteroidetes, Proteobacteria, Acidobacteria, Firmicutes, Actinobacteria, Dictyoglomi and some fungi. Although identical sequences were found in several sites, habitat-specific patterns appeared to be important, and geochemical factors such as pH and oxygen content significantly influenced the compositions of xylan-degrading microbial communities. Conclusion/Significance These results provide insight into the GH 10 xylanases in various soil environments and reveal that xylan-degrading microbial communities are environment specific with diverse and abundant populations. PMID:22912883

  11. Spatial distribution and accessibility to public sector tertiary care teaching hospitals in Karachi: A Geographic Information Systems application.

    PubMed

    Shaikh, Masood Ali; Ali, Mir Shabbar

    2016-07-01

    Optimal utilization of specialized curative healthcare services is contingent on spatial access to tertiary-care hospitals by the targeted population. The objectives of this study were to determine the spatial distribution of public sector tertiary-care teaching hospitals in Karachi, and to use GIS and network analysis for modeling the accessibility to these hospitals for Karachi residents. Maps of three, six, and nine kilometer buffers were created around the five selected hospitals to determine which towns of Karachi are either entirely or partially covered/accessible. Most of the towns in Karachi were covered either partially or completely by the three buffers and service areas of 3,6, and 9 kilometers around the five selected hospitals. This study highlights the limitations of using publicly available data for road network, and the need for creating and making available in public domain, comprehensive road network vector dataset in conjunction with population breakdowns by administrative subdivisions. PMID:27427142

  12. Determination of Spatial Distribution of Children Treated in Children Oncology Clinic with the Aid of Geographic Information Systems.

    PubMed

    Topan, Aysel; Bayram, Dilek; Özendi, Mustafa; Cam, Ali; Öztürk, Özlem; Ayyıldız, Tülay Kuzlu; Kulakçı, Hülya; Veren, Funda

    2016-10-01

    The main objective of this research is to examine child cancer cases in Zonguldak/Turkey descriptively in epidemiological aspect with the help of GIS. Universe of the study is composed of 60 children between 1 and 19 years old who were treated in Children Oncology Clinic with a diagnosis of cancer. Whole universe was reached without selecting a sample in the study. Data were collected by using a form prepared by obtaining expert advice and they were applied to children and their parents at study dates. Results were expressed as percentages. Chi-Square test was used in intergroup comparisons, results were assessed within 95 % confidence interval and p < 0.05 was considered as statistically significant. Variables that were used in the study were assessed, recorded in prepared data collection form and distribution maps were produced. When disease diagnosis of the children participated in the study were evaluated, the most observed three types are ALL with 33.3 % (n = 20), Medullablastoma with 13.3 % (n = 8) and Hodgkin-nonHodgkin Lymphoma with 11.7 % (n = 7). Kdz. Eregli with 31.7 % (n = 19), Center with 31.7 % (n = 19), and Caycuma with 18.3 % (n = 11) are the first-three counties where the cases were mostly observed. Statistically significant difference was found (p = 0.016) comparing disease diagnosis with living place, and distribution maps of the number of cancer cases were produced. PMID:27624492

  13. Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Ratten, Jenni-Marie; LaRoche, Julie; Desai, Dhwani K.; Shelley, Rachel U.; Landing, William M.; Boyle, Ed; Cutter, Gregory A.; Langlois, Rebecca J.

    2015-06-01

    Biological nitrogen fixation (BNF) supplies nutrient-depleted oceanic surface waters with new biologically available fixed nitrogen. Diazotrophs are the only organisms that can fix dinitrogen, but the factors controlling their distribution patterns in the ocean are not well understood. In this study, the relative abundances of eight diazotrophic phylotypes in the subtropical North Atlantic Ocean were determined by quantitative PCR (qPCR) of the nifH gene using TaqMan probes. A total of 152 samples were collected at 27 stations during two GEOTRACES cruises; Lisbon, Portugal to Mindelo, Cape Verde Islands (USGT10) and Woods Hole, MA, USA via the Bermuda Time Series (BATS) to Praia, Cape Verde Islands (USGT11). Seven of the eight diazotrophic phylotypes tested were detected. These included free-living and symbiotic cyanobacteria (unicellular groups (UCYN) A, B and C, Trichodesmium, the diatom-associated cyanobacteria Rhizoselinia-Richelia and Hemiaulus-Richelia) and a γ-proteobacterium (Gamma A, AY896371). The nifH gene abundances were analyzed in the context of a large set of hydrographic parameters, macronutrient and trace metal concentrations measured in parallel with DNA samples using the PRIMER-E software. The environmental variables that most influenced the abundances and distribution of the diazotrophic phylotypes were determined. We observed a geographic segregation of diazotrophic phylotypes between east and west, with UCYN A, UCYN B and UCYN C and the Rhizosolenia-Richelia symbiont associated with the eastern North Atlantic (east of 40°W), and Trichodesmium and Gamma A detected across the basin. Hemiaulus-Richelia symbionts were primarily found in temperate waters near the North American coast. The highest diazotrophic phylotype abundance and diversity were associated with temperatures greater than 22 °C in the surface mixed layer, a high supply of iron from North African aeolian mineral dust deposition and from remineralized nutrients upwelled at the

  14. Changes in plantar load distribution and gait pattern following foot drop correction in leprosy affected patients.

    PubMed

    Karmakar, Mrinmoy; Joshua, Jerry; Mahato, Nidhu

    2015-09-01

    This study was done to compare the changes in plantar load (weight distribution) and gait patterns before and after tibialis posterior transfer surgery in people affected by leprosy. Changes in gait patterns were observed and proportionate changes in plantar load were quantified using data captured by a baropodometer. All the eight patients who underwent tibialis posterior transfer surgery in 2013 in our hospital were included in the study. In addition to the regular pre-operative and post-operative assessments, the patients also underwent baropodometric evaluation. There was a significant change in plantar load at the heel, lateral border and forefoot. Using the foot pressure scan, it was noted that the progression of the centre of mass (displayed graphically as 'the gait line') was also affected by the altered pattern of weight distribution. This study reiterates the importance of tibialis posterior transfer because: it restores the normal gait pattern of 1, 2, 3 (where 1 is heel strike, 2 is mid foot contact and 3 is forefoot contact) and provides a more uniform distribution of planter load. PMID:26665356

  15. The geographic distribution of fluoride in surface and groundwater in Ethiopia with an emphasis on the Rift Valley.

    PubMed

    Tekle-Haimanot, Redda; Melaku, Zenebe; Kloos, Helmut; Reimann, Clemens; Fantaye, Wondwossen; Zerihun, Legesse; Bjorvatn, Kjell

    2006-08-15

    This paper analyzes the most extensive database on fluoride distribution in Ethiopia. Of the total 1438 water samples tested, 24.2% had fluoride concentrations above the 1.5 mg/l recommended optimum concentration recommended by WHO. Regionally, by far the highest fluoride levels were recorded in the Rift Valley, where 41.2% of all samples exceeded the 1.5 mg/l level. Only 1.0% of the samples from the central and northwestern highlands and 10.0% in the southeastern highlands exceeded 1.5 mg/l. Larger proportions of deep wells (50.0%) and hot springs (90.0%) than shallow wells (27.2%) and cold springs (12.6%) exceeded the 1.5 mg/l level. The highest fluoride concentrations were recorded for Rift Valley lakes Shala (264.0 mg/l) and Abijata (202.4 mg/l) and the lowest in Lake Tana, and rivers, wells and springs in the highlands. The fluoride concentrations of the Awash River, which originates in the highlands and flows through the Rift Valley, increase downstream, giving concern over the current diversion of high-fluoride water from Lake Beseka. Of the various flourosis prevention methods tried in Ethiopia, the treatment of surface water has been shown to be the most feasible and effective for towns and large commercial farms in the Rift Valley, although defluoridation methods should be considered for smaller rural communities. PMID:16360195

  16. Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa-Chromosomal Monophyly and Broad Geographic Distribution.

    PubMed

    Antonation, Kym S; Grützmacher, Kim; Dupke, Susann; Mabon, Philip; Zimmermann, Fee; Lankester, Felix; Peller, Tianna; Feistner, Anna; Todd, Angelique; Herbinger, Ilka; de Nys, Hélène M; Muyembe-Tamfun, Jean-Jacques; Karhemere, Stomy; Wittig, Roman M; Couacy-Hymann, Emmanuel; Grunow, Roland; Calvignac-Spencer, Sébastien; Corbett, Cindi R; Klee, Silke R; Leendertz, Fabian H

    2016-09-01

    Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats) in West and Central Africa (Côte d'Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo). The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans. PMID:27607836

  17. Species Diversity of Ramphogordius sanguineus/Lineus ruber-Like Nemerteans (Nemertea: Heteronemertea) and Geographic Distribution of R. sanguineus.

    PubMed

    Kang, Xing-Xing; Fernández-Álvarez, Fernando Ángel; Alfaya, José E F; Machordom, Annie; Strand, Malin; Sundberg, Per; Sun, Shi-Chun

    2015-12-01

    Heteronemerteans, such as Lineus ruber, L. viridis, Ramphogordius sanguineus, R. lacteus, Riseriellus occultus, and Micrura varicolor, share many similar external characters. Although several internal characters useful for distinguishing these nemertean species have been documented, their identification is based mostly on coloration, the shape of the head, and how they contract, which may not be always reliable. We sequenced the mitochondrial COI gene for 160 specimens recently collected from 27 locations around the world (provisionally identified as the above species, according to external characters and contraction patterns, with most of them as R. sanguineus). Based on these specimens, together with sequences of 16 specimens from GenBank, we conducted a DNA-based species delimitation/identification by means of statistical parsimony and phylogenetic analyses. Our results show that the analyzed specimens may contain nine species, which can be separated by large genetic gaps; heteronemerteans with an external appearance similar to R. sanguineus/Lineus ruber/L. viridis have high species diversity in European waters from where eight species can be discriminated. Our 42 individuals from Vancouver Island (Canada) are revealed to be R. sanguineus, which supports an earlier argument that nemerteans reported as L. ruber or L. viridis from the Pacific Northwest may refer to this species. We report R. sanguineus from Chile, southern China, and the species is also distributed on the Atlantic coast of South America (Argentina). In addition, present analyses reveal the occurrence of L. viridis in Qingdao, which is the first record of the species from Chinese waters. PMID:26654041

  18. Genetic differentiation in Elaeocarpus photiniifolia (Elaeocarpaceae) associated with geographic distribution and habitat variation in the Bonin (Ogasawara) Islands.

    PubMed

    Sugai, Kyoko; Setsuko, Suzuki; Nagamitsu, Teruyoshi; Murakami, Noriaki; Kato, Hidetoshi; Yoshimaru, Hiroshi

    2013-11-01

    Gene flow between populations in different environmental conditions can be limited due to divergent natural selection, thus promoting genetic differentiation. Elaeocarpus photiniifolia, an endemic tree species in the Bonin Islands, is distributed in two types of habitats, dry scrubs and mesic forests. We aim to elucidate the genetic differentiation in E. photiniifolia within and between islands and between the habitat types. We investigated genotypes of 639 individuals from 19 populations of E. photiniifolia and its closely-related E. sylvestris at 24 microsatellite loci derived from expressed sequence tags. The data revealed genetic differentiation (1) between E. photiniifolia and E. sylvestris (0.307 ≤ F ST ≤ 0.470), (2) between the E. photiniifolia populations of the Chichijima and Hahajima Island Groups in the Bonin Islands (0.033 ≤ F ST ≤ 0.121) and (3) between E. photiniifolia populations associated with dry scrubs and mesic forests in the Chichijima Island Group (0.005 ≤ F ST ≤ 0.071). Principal coordinate analysis and Bayesian clustering analysis also showed that genetically distinct groups were associated with the habitat types, and isolation by distance was not responsible for the genetic differentiation. These findings suggest that E. photiniifolia is divided into genetically differentiated groups associated with different environmental conditions in the Bonin Islands. PMID:23748372

  19. Genetic diversity and geographic distribution of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) genotypes associated with cassava in East Africa

    PubMed Central

    Mugerwa, Habibu; Rey, Marie E C; Alicai, Titus; Ateka, Elijah; Atuncha, Hellen; Ndunguru, Joseph; Sseruwagi, Peter

    2012-01-01

    The genetic variability of whitefly (Bemisia tabaci) species, the vectors of cassava mosaic begomoviruses (CMBs) in cassava growing areas of Kenya, Tanzania, and Uganda, was investigated through comparison of partial sequences of the mitochondria cytochrome oxidase I (mtCOI) DNA in 2010/11. Two distinct species were obtained including sub-Saharan Africa 1 (SSA1), comprising of two sub-clades (I and II), and a South West Indian Ocean Islands (SWIO) species. Among the SSA1, sub-clade I sequences shared a similarity of 97.8–99.7% with the published Uganda 1 genotypes, and diverged by 0.3–2.2%. A pairwise comparison of SSA1 sub-clade II sequences revealed a similarity of 97.2–99.5% with reference southern Africa genotypes, and diverged by 0.5–2.8%. The SSA1 sub-clade I whiteflies were widely distributed in East Africa (EA). In comparison, the SSA1 sub-clade II whiteflies were detected for the first time in the EA region, and occurred predominantly in the coast regions of Kenya, southern and coast Tanzania. They occurred in low abundance in the Lake Victoria Basin of Tanzania and were widespread in all four regions in Uganda. The SWIO species had a sequence similarity of 97.2–97.7% with the published Reunion sequence and diverged by 2.3–2.8%. The SWIO whiteflies occurred in coast Kenya only. The sub-Saharan Africa 2 whitefly species (Ug2) that was associated with the severe CMD pandemic in Uganda was not detected in our study. PMID:23170210

  20. Ecological factors responsible for the geographic distribution of Rhabdias joaquinensis: where do lungworms infect anurans in nature?

    PubMed

    Langford, Gabriel J; Janovy, John

    2016-03-01

    The lungworm Rhabdias joaquinensis (Nematoda: Rhabdiasidae) is a common parasite of anurans in eastern Nebraska, yet absent from the same hosts in western Nebraska. This study investigated the ecology of the lungworm's free-living stages that reside in host feces and surrounding soils to establish the worm's free-living niche in eastern Nebraska. Using a comparative method, this study also investigated the absence of lungworms in western Nebraska's Sandhills. Soil composition, moisture, and temperature were experimentally varied in the laboratory to assess their effects on juvenile development and survival. Field mesocosm and host defecation experiments were used to determine where in nature lungworms survive and eventually infect frogs and toads and to discover if vegetation facilitates lungworm transmission to hosts. The results found loam soils were amenable to lungworm development, whereas soils with high clay or sand content produced few infective lungworms. Soil moisture <50 % did not support lungworm development. Infective juveniles successfully developed between 5 and 35 °C, albeit at different rates, whereas only a limited number of non-infective worms developed at 40 °C. Field studies found that shoreline environments supported lungworm development, and the majority of lungworm infections appear to occur within a zone of infection adjacent to shorelines in eastern Nebraska. The prevalence in vegetation mesocosms was 100 %, and a significantly higher mean abundance was found in toads from containers with vegetation than without. Overall, these experiments suggest that the spatial distribution of R. joaquinensis in Nebraska is constrained by the worm's ability to survive and reproduce in a soil matrix. PMID:26666887

  1. J-Western Forms of Helicobacter pylori cagA Constitute a Distinct Phylogenetic Group with a Widespread Geographic Distribution

    PubMed Central

    Duncan, Stacy S.; Valk, Pieter L.; Shaffer, Carrie L.

    2012-01-01

    Chronic infection with Helicobacter pylori strains expressing the bacterial oncoprotein CagA confers an increased risk of gastric cancer. While much is known about the ancestry and molecular evolution of Western, East Asian, and Amerindian cagA sequences, relatively little is understood about a fourth group, known as “J-Western,” which has been detected mainly in strains from Okinawa, Japan. We show here that J-Western cagA sequences have a more widespread global distribution than previously recognized, occur in strains with multiple different ancestral origins (based on multilocus sequence typing [MLST] analysis), and did not arise recently. As shown by comparisons of Western and J-Western forms of CagA, there are 45 fixed or nearly fixed amino acid differences, and J-Western forms contain a unique 4-amino-acid insertion. The mean nucleotide diversity of synonymous sites (πs) is slightly lower in the J-Western group than in the Western and East Asian groups (0.066, 0.086, and 0.083, respectively), which suggests that the three groups have comparable, but not equivalent, effective population sizes. The reduced πs of the J-Western group is attributable to ancestral recombination events within the 5′ region of cagA. Population genetic analyses suggest that within the cagA region encoding EPIYA motifs, the East Asian group underwent a marked reduction in effective population size compared to the Western and J-Western groups, in association with positive selection. Finally, we show that J-Western cagA sequences are found mainly in strains producing m2 forms of the secreted VacA toxin and propose that these functionally interacting proteins coevolved to optimize the gastric colonization capacity of H. pylori. PMID:22247512

  2. Factors affecting the distribution of natural and anthropogenic radionuclides in the coastal Burullus Lake.

    PubMed

    El-Reefy, H I; Badran, H M; Sharshar, T; Hilal, M A; Elnimr, T

    2014-08-01

    In the present study, measurements of naturally occurring radioactive materials and (137)Cs activity in sediment were conducted for locations covering the entire Burullus Lake in order to gather information about radionuclides mobility and distribution. Low-background γ-spectrometry was employed to determine the activity concentrations of water and sediment samples. The activity concentrations of (226)Ra and (232)Th are close to uniform distribution in the lake environment. Among the different physical and chemical characteristics measured for water and sediment, only salinity and total organic matter content have the potential to affect the mobility of (137)Cs and (40)K. The results suggest that these two radionuclides are attached to different mobile particulates. Increasing salinity tends to strengthen the adsorption of (137)Cs and solubilization of (40)K in sediment. On the other hand, sediment with high organic matter content traps (137)Cs and (40)K associated particulates to bottom sediment. PMID:24657852

  3. New Insights into the Geographic Distribution of Mycobacterium leprae SNP Genotypes Determined for Isolates from Leprosy Cases Diagnosed in Metropolitan France and French Territories

    PubMed Central

    Reibel, Florence; Chauffour, Aurélie; Brossier, Florence; Jarlier, Vincent; Cambau, Emmanuelle; Aubry, Alexandra

    2015-01-01

    Background Between 20 and 30 bacteriologically confirmed cases of leprosy are diagnosed each year at the French National Reference Center for mycobacteria. Patients are mainly immigrants from various endemic countries or living in French overseas territories. We aimed at expanding data regarding the geographical distribution of the SNP genotypes of the M. leprae isolates from these patients. Methodology/Principal findings Skin biopsies were obtained from 71 leprosy patients diagnosed between January 2009 and December 2013. Data regarding age, sex and place of birth and residence were also collected. Diagnosis of leprosy was confirmed by microscopic detection of acid-fast bacilli and/or amplification by PCR of the M. leprae-specific RLEP region. Single nucleotide polymorphisms (SNP), present in the M. leprae genome at positions 14 676, 1 642 875 and 2 935 685, were determined with an efficiency of 94% (67/71). Almost all patients were from countries other than France where leprosy is still prevalent (n = 31) or from French overseas territories (n = 36) where leprosy is not totally eradicated, while only a minority (n = 4) was born in metropolitan France but have lived in other countries. SNP type 1 was predominant (n = 33), followed by type 3 (n = 17), type 4 (n = 11) and type 2 (n = 6). SNP types were concordant with those previously reported as prevalent in the patients’ countries of birth. SNP types found in patients born in countries other than France (Comoros, Haiti, Benin, Congo, Sri Lanka) and French overseas territories (French Polynesia, Mayotte and La Réunion) not covered by previous work correlated well with geographical location and history of human settlements. Conclusions/Significance The phylogenic analysis of M. leprae strains isolated in France strongly suggests that French leprosy cases are caused by SNP types that are (a) concordant with the geographic origin or residence of the patients (non-French countries, French overseas territories

  4. A decrease in phytic acid content substantially affects the distribution of mineral elements within rice seeds.

    PubMed

    Sakai, Hiroaki; Iwai, Toru; Matsubara, Chie; Usui, Yuto; Okamura, Masaki; Yatou, Osamu; Terada, Yasuko; Aoki, Naohiro; Nishida, Sho; Yoshida, Kaoru T

    2015-09-01

    Phytic acid (myo-inositol hexakisphosphate; InsP6) is the storage compound of phosphorus and many mineral elements in seeds. To determine the role of InsP6 in the accumulation and distribution of mineral elements in seeds, we performed fine mappings of mineral elements through synchrotron-based X-ray microfluorescence analysis using developing seeds from two independent low phytic acid (lpa) mutants of rice (Oryza sativa L.). The reduced InsP6 in lpa seeds did not affect the translocation of mineral elements from vegetative organs into seeds, because the total amounts of phosphorus and the other mineral elements in lpa seeds were identical to those in the wild type (WT). However, the reduced InsP6 caused large changes in mineral localization within lpa seeds. Phosphorus and potassium in the aleurone layer of lpa greatly decreased and diffused into the endosperm. Zinc and copper, which were broadly distributed from the aleurone layer to the inner endosperm in the WT, were localized in the narrower space around the aleurone layer in lpa mutants. We also confirmed that similar distribution changes occurred in transgenic rice with the lpa phenotype. Using these results, we discussed the role of InsP6 in the dynamic accumulation and distribution patterns of mineral elements during seed development. PMID:26259185

  5. Diversity and geographical distribution of Flavobacterium psychrophilum isolates and their phages: patterns of susceptibility to phage infection and phage host range.

    PubMed

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio; Middelboe, Mathias

    2014-05-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme analysis (DGREA) and their susceptibility to 33 bacteriophages isolated in Chile and Denmark, thus covering large geographical (>12,000 km) and temporal (>60 years) scales of isolation. An additional 40 phage-resistant isolates obtained from culture experiments after exposure to specific phages were examined for changes in phage susceptibility against the 33 phages. The F. psychrophilum and phage populations isolated from Chile and Denmark clustered into geographically distinct groups with respect to DGREA profile and host range, respectively. However, cross infection between Chilean phage isolates and Danish host isolates and vice versa was observed. Development of resistance to certain bacteriophages led to susceptibility to other phages suggesting that "enhanced infection" is potentially an important cost of resistance in F. psychrophilum, possibly contributing to the observed co-existence of phage-sensitive F. psychrophilum strains and lytic phages across local and global scales. Overall, our results showed that despite the identification of local communities of phages and hosts, some key properties determining phage infection patterns seem to be globally distributed. PMID:24557506

  6. The importance of the covariation of the geographical distribution of SSTs and deep convection for tropical tropospheric temperature trends 1980-present

    NASA Astrophysics Data System (ADS)

    Fueglistaler, Stephan; Flannaghan, Thomas; Po-Chedley, Stephen; Held, Isaac; Radley, Claire; Zhao, Ming; Wyman, Bruce

    2016-04-01

    Enhanced upper tropospheric warming relative to the surface in the tropics is a prominent feature of numerical model simulations, but it has been suggested that models overestimate this warming compared to observations for the period 1980 to present. Here, we focus on the factors controlling atmospheric temperature trends in numerical model calculations with prescribed Sea Surface Temperatures (SSTs). CMIP5 model runs show a remarkably large spread in tropical temperature trends over the period 1980-2008 despite being forced with observed SSTs. Here, we show that the model trends are consistent with the atmospheric temperature profile being tightly constrained by the surface layer conditions in regions of deep convection. Large trend differences arise from the use of two different SST data, the "HURRELL" and the "HadISST1" data. These two SSTs have very similar tropical average trends, but differ substantially in the warmest percentiles where most deep convection occurs. The models' temperature trend differences in the tropical troposphere reflect the trend differences in the regions of highest SSTs. Further, we show that trend differences in model calculations using identical SSTs is strongly related to differences in the geographical pattern of strong precipitation (used as a simple proxy for deep convection) between models, and between ensemble runs of a model. The time series of precipitation weighted SSTs can explain more than half of the variance in temperature trends. The variance in trends between ensemble members of the same model, and between ensemble means of different models, is similar. However, the decrease in variance upon averaging over ensemble members is modest compared to the expected scaling for independent samples, which provides evidence for systematic differences between models in their response in the geographical distribution of convection to changes in SST patterns.

  7. SOCIO-DEMOGRAPHIC CHARACTERISTICS AND GEOGRAPHIC DISTRIBUTION OF REPORTED MALARIA CASES IN BANGKA DISTRICT, BABEL ISLAND PROVINCE, INDONESIA DURING 2008-2012.

    PubMed

    Shodianal; Kamigaki, Taro; Oshitani, Hitoshi

    2015-11-01

    Malaria is a major health problem in many developing countries including Indonesia. The purpose of this study was to investigate the socio-demographic characteristics and geographic distribution of malaria cases in Bangka District, Bangka-Belitung Island Province, Indonesia. Bangka District is a malaria endemic area of Indonesia. We analyzed the epidemiological data of all reported malaria cases during 2008-2012 in Bangka District. Of the 4,756 malaria-confirmed cases reported during the study period, 3,234 (68. 0%) were among persons aged ≥ 15 years, 1,024 (21.5%) were among persons aged 5-14 years and 498 (10.5%) were among persons aged < 5 years. Malaria cases were primarily located along the sea coast and less frequently in inland. Malaria cases were found not only among the local population but also among migrant workers. The monthly incidence of reported malaria cases in the study population ranged from 0.06 to 1.06 per 1,000 person-months. The cases were mostly due to Plasmodium vivax (57.1%) followed by Plasmodiumfalciparum (40.2%). Plasmodiumfalciparum was more common among migrant workers while Plasmodium vivax was more common among the local population (Odds ratio 1.2; p = 0.03). The main transmission vector found in the coastal area was Anopheles sundaicus. An. letifer and An. barbirostris were found inland. We identified "malaria hot-spots" in the study area using a Geographic Information System. The results of this study will contribute to the malaria control program. PMID:26867354

  8. Statistical analysis of factors affecting landslide distribution in the new Madrid seismic zone, Tennessee and Kentucky

    USGS Publications Warehouse

    Jibson, R.W.; Keefer, D.K.

    1989-01-01

    More than 220 large landslides along the bluffs bordering the Mississippi alluvial plain between Cairo, Ill., and Memphis, Tenn., are analyzed by discriminant analysis and multiple linear regression to determine the relative effects of slope height and steepness, stratigraphic variation, slope aspect, and proximity to the hypocenters of the 1811-12 New Madrid, Mo., earthquakes on the distribution of these landslides. Three types of landslides are analyzed: (1) old, coherent slumps and block slides, which have eroded and revegetated features and no active analogs in the area; (2) old earth flows, which are also eroded and revegetated; and (3) young rotational slumps, which are present only along near-river bluffs, and which are the only young, active landslides in the area. Discriminant analysis shows that only one characteristic differs significantly between bluffs with and without young rotational slumps: failed bluffs tend to have sand and clay at their base, which may render them more susceptible to fluvial erosion. Bluffs having old coherent slides are significantly higher, steeper, and closer to the hypocenters of the 1811-12 earthquakes than bluffs without these slides. Bluffs having old earth flows are likewise higher and closer to the earthquake hypocenters. Multiple regression analysis indicates that the distribution of young rotational slumps is affected most strongly by slope steepness: about one-third of the variation in the distribution is explained by variations in slope steepness. The distribution of old coherent slides and earth flows is affected most strongly by slope height, but the proximity to the hypocenters of the 1811-12 earthquakes also significantly affects the distribution. The results of the statistical analyses indicate that the only recently active landsliding in the area is along actively eroding river banks, where rotational slumps formed as bluffs are undercut by the river. The analyses further indicate that the old coherent slides

  9. Two Distinct Hepatitis C Virus Genotype 1a Clades Have Different Geographical Distribution and Association With Natural Resistance to NS3 Protease Inhibitors.

    PubMed

    De Luca, Andrea; Di Giambenedetto, Simona; Lo Presti, Alessandra; Sierra, Saleta; Prosperi, Mattia; Cella, Eleonora; Giovanetti, Marta; Torti, Carlo; Caudai, Cinzia; Vicenti, Ilaria; Saladini, Francesco; Almi, Paolo; Grima, Pierfrancesco; Blanc, Pierluigi; Fabbiani, Massimiliano; Rossetti, Barbara; Gagliardini, Roberta; Kaiser, Rolf; Ciccozzi, Massimo; Zazzi, Maurizio

    2015-04-01

    Background.  Hepatitis C virus (HCV) genotype 1 is the most prevalent worldwide. Subtype 1a, compared with 1b, shows lower response rates and higher propensity to select for drug resistance to NS3 and selected NS5A and nonnucleoside NS5B inhibitors. Two distinct clades of subtype 1a have been described. Methods.  Using Bayesian methodology, we performed a time-scaled phylogeny reconstruction of clade separation and characterized the geographic distribution, phylodynamics, and association with natural resistance variants of NS3 sequences from 362 patients carrying subtype 1a HCV. Results.  All sequences segregated in 2 clearly distinct clades. Clade I showed an earlier origin from the common ancestor compared with clade II. Clade I virus was more prevalent in non-European countries, represented mostly by United States, compared with European (75.7% vs 49.3%; P < .001). The prevalence of the natural NS3 variant Q80K, associated with resistance to the macrocyclic protease inhibitor simeprevir, was detected in 51.6% of clade I and 0% of clade II (P < .001); clade I showed a lower genetic barrier for Q80K, whereas no sign of selective pressure at any protease inhibitor resistance-associated codon was detected. Conclusions.  Hepatitis C virus subtype 1a clades have a clearly different distribution in Europe and the United States, and the natural resistance mutation Q80K is exclusively associated with clade I. PMID:26213689

  10. Multiple locus VNTR analysis highlights that geographical clustering and distribution of Dichelobacter nodosus, the causal agent of footrot in sheep, correlates with inter-country movements☆

    PubMed Central

    Russell, Claire L.; Smith, Edward M.; Calvo-Bado, Leonides A.; Green, Laura E.; Wellington, Elizabeth M.H.; Medley, Graham F.; Moore, Lynda J.; Grogono-Thomas, Rosemary

    2014-01-01

    Dichelobacter nodosus is a Gram-negative, anaerobic bacterium and the causal agent of footrot in sheep. Multiple locus variable number tandem repeat (VNTR) analysis (MLVA) is a portable technique that involves the identification and enumeration of polymorphic tandem repeats across the genome. The aims of this study were to develop an MLVA scheme for D. nodosus suitable for use as a molecular typing tool, and to apply it to a global collection of isolates. Seventy-seven isolates selected from regions with a long history of footrot (GB, Australia) and regions where footrot has recently been reported (India, Scandinavia), were characterised. From an initial 61 potential VNTR regions, four loci were identified as usable and in combination had the attributes required of a typing method for use in bacterial epidemiology: high discriminatory power (D > 0.95), typeability and reproducibility. Results from the analysis indicate that D. nodosus appears to have evolved via recombinational exchanges and clonal diversification. This has resulted in some clonal complexes that contain isolates from multiple countries and continents; and others that contain isolates from a single geographic location (country or region). The distribution of alleles between countries matches historical accounts of sheep movements, suggesting that the MLVA technique is sufficiently specific and sensitive for an epidemiological investigation of the global distribution of D. nodosus. PMID:23748018

  11. Two Distinct Hepatitis C Virus Genotype 1a Clades Have Different Geographical Distribution and Association With Natural Resistance to NS3 Protease Inhibitors

    PubMed Central

    De Luca, Andrea; Di Giambenedetto, Simona; Lo Presti, Alessandra; Sierra, Saleta; Prosperi, Mattia; Cella, Eleonora; Giovanetti, Marta; Torti, Carlo; Caudai, Cinzia; Vicenti, Ilaria; Saladini, Francesco; Almi, Paolo; Grima, Pierfrancesco; Blanc, Pierluigi; Fabbiani, Massimiliano; Rossetti, Barbara; Gagliardini, Roberta; Kaiser, Rolf; Ciccozzi, Massimo; Zazzi, Maurizio

    2015-01-01

    Background. Hepatitis C virus (HCV) genotype 1 is the most prevalent worldwide. Subtype 1a, compared with 1b, shows lower response rates and higher propensity to select for drug resistance to NS3 and selected NS5A and nonnucleoside NS5B inhibitors. Two distinct clades of subtype 1a have been described. Methods. Using Bayesian methodology, we performed a time-scaled phylogeny reconstruction of clade separation and characterized the geographic distribution, phylodynamics, and association with natural resistance variants of NS3 sequences from 362 patients carrying subtype 1a HCV. Results. All sequences segregated in 2 clearly distinct clades. Clade I showed an earlier origin from the common ancestor compared with clade II. Clade I virus was more prevalent in non-European countries, represented mostly by United States, compared with European (75.7% vs 49.3%; P < .001). The prevalence of the natural NS3 variant Q80K, associated with resistance to the macrocyclic protease inhibitor simeprevir, was detected in 51.6% of clade I and 0% of clade II (P < .001); clade I showed a lower genetic barrier for Q80K, whereas no sign of selective pressure at any protease inhibitor resistance-associated codon was detected. Conclusions. Hepatitis C virus subtype 1a clades have a clearly different distribution in Europe and the United States, and the natural resistance mutation Q80K is exclusively associated with clade I. PMID:26213689

  12. High morphological plasticity and global geographical distribution of the Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum): molecular and morphological survey.

    PubMed

    Hernández-Orts, Jesús Servando; Scholz, Tomáš; Brabec, Jan; Kuzmina, Tetiana; Kuchta, Roman

    2015-09-01

    The most important causative agent of human diphyllobothriosis in South America, Diphyllobothrium pacificum, is transferred to the original genus Adenocephalus Nybelin, 1931; revised and redescribed on the basis of the evaluation of an extensive material collected mainly from northern fur seal, Callorhinus ursinus, from St. Paul Island, Alaska. Detailed analysis of morphological and morphometrical data shows a high variability in most of the characteristics traditionally used in diagnosis of diphyllobothriid tapeworms. Phylogenetic analyses based on newly characterised sequences of mitochondrial cytochrome c oxidase subunit 1 and nuclear large subunit ribosomal RNA genes consistently reveal Adenocephalus pacificus as a sister lineage to the clade formed of the remaining Diphyllobothrium species and other genera (Digramma, Diplogonoporus, Ligula). Despite the generally similar morphology, A. pacificus can be differentiated from the closely related taxa in the presence of transverse papilla-like tegumental protuberances distributed anteriorly, separated by narrow semicircular grooves on the ventral surface of proglottids between their anterior margin and the anterior edge of the male gonopore, and relatively small eggs. A. pacificus displays a relatively low host specificity (found in 9 of 16 otariids, and in accidental hosts such as man, dog and jackal, the latter representing a new host) and a uniquely wide geographical distribution on both hemispheres. In addition, suitability of morphological criteria used in diagnostics of diphyllobothriid cestodes is discussed. PMID:26001974

  13. Archipelago colonization by ecologically dissimilar amphibians: evaluating the expectation of common evolutionary history of geographical diffusion in co-distributed rainforest tree frogs in islands of Southeast Asia.

    PubMed

    Gonzalez, Paulette; Su, Yong-Chao; Siler, Cameron D; Barley, Anthony J; Sanguila, Marites B; Diesmos, Arvin C; Brown, Rafe M

    2014-03-01

    Widespread, co-distributed species with limited relative dispersal abilities represent compelling focal taxa for comparative phylogeography. Forest vertebrates in island archipelagos often exhibit pronounced population structure resulting from limited dispersal abilities or capacity to overcome marine barriers to dispersal. The exceptionally diverse Old World tree frogs of the family Rhacophoridae have colonized the forested island archipelagos of Southeast Asia on multiple occasions, entering the islands of Indonesia and the Philippines via a "stepping stone" mode of dispersal along elongate island chains, separated by a series of marine channels. Here we evaluate the prediction that two tightly co-distributed Philippine rhacophorids colonized the archipelago during concomitant timescales and in the same, linear, "island-hopping" progression. We use a new multilocus dataset, utilize dense genetic sampling from the eastern arc of the Philippines, and we take a model-based phylogeographic approach to examining the two species for similar topological patterns of diversification, genetic structure, and timescales of diversification. Our results support some common mechanistic predictions (a general south-to-north polarity of colonization) but not others (timescale for colonization and manner and degree of lineage diversification), suggesting differing biogeographic scenarios of geographical diffusion through the archipelago and unique and idiosyncratic ecological capacities and evolutionary histories of each species. PMID:24389467

  14. Geographic Analysis of the Radiation Oncology Workforce

    SciTech Connect

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

    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.

  15. 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.

    PubMed

    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

  16. Mapping Species Distributions with MAXENT Using a Geographically Biased Sample of Presence Data: A Performance Assessment of Methods for Correcting Sampling Bias

    PubMed Central

    Fourcade, Yoan; Engler, Jan O.; Rödder, Dennis; Secondi, Jean

    2014-01-01

    MAXENT is now a common species distribution modeling (SDM) tool used by conservation practitioners for predicting the distribution of a species from a set of records and environmental predictors. However, datasets of species occurrence used to train the model are often biased in the geographical space because of unequal sampling effort across the study area. This bias may be a source of strong inaccuracy in the resulting model and could lead to incorrect predictions. Although a number of sampling bias correction methods have been proposed, there is no consensual guideline to account for it. We compared here the performance of five methods of bias correction on three datasets of species occurrence: one “virtual” derived from a land cover map, and two actual datasets for a turtle (Chrysemys picta) and a salamander (Plethodon cylindraceus). We subjected these datasets to four types of sampling biases corresponding to potential types of empirical biases. We applied five correction methods to the biased samples and compared the outputs of distribution models to unbiased datasets to assess the overall correction performance of each method. The results revealed that the ability of methods to correct the initial sampling bias varied greatly depending on bias type, bias intensity and species. However, the simple systematic sampling of records consistently ranked among the best performing across the range of conditions tested, whereas other methods performed more poorly in most cases. The strong effect of initial conditions on correction performance highlights the need for further research to develop a step-by-step guideline to account for sampling bias. However, this method seems to be the most efficient in correcting sampling bias and should be advised in most cases. PMID:24818607

  17. 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

    PubMed Central

    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

  18. The Geographic Distribution of Loa loa in Africa: Results of Large-Scale Implementation of the Rapid Assessment Procedure for Loiasis (RAPLOA)

    PubMed Central

    Zouré, Honorat Gustave Marie; Wanji, Samuel; Noma, Mounkaïla; Amazigo, Uche Veronica; Diggle, Peter J.; Tekle, Afework Hailemariam; Remme, Jan H. F.

    2011-01-01

    Background Loiasis is a major obstacle to ivermectin treatment for onchocerciasis control and lymphatic filariasis elimination in central Africa. In communities with a high level of loiasis endemicity, there is a significant risk of severe adverse reactions to ivermectin treatment. Information on the geographic distribution of loiasis in Africa is urgently needed but available information is limited. The African Programme for Onchocerciasis Control (APOC) undertook large scale mapping of loiasis in 11 potentially endemic countries using a rapid assessment procedure for loiasis (RAPLOA) that uses a simple questionnaire on the history of eye worm. Methodology/Principal Findings RAPLOA surveys were done in a spatial sample of 4798 villages covering an area of 2500×3000 km centred on the heartland of loiasis in Africa. The surveys showed high risk levels of loiasis in 10 countries where an estimated 14.4 million people live in high risk areas. There was a strong spatial correlation among RAPLOA data, and kriging was used to produce spatially smoothed contour maps of the interpolated prevalence of eye worm and the predictive probability that the prevalence exceeds 40%. Conclusion/Significance The contour map of eye worm prevalence provides the first global map of loiasis based on actual survey data. It shows a clear distribution with two zones of hyper endemicity, large areas that are free of loiasis and several borderline or intermediate zones. The surveys detected several previously unknown hyperendemic foci, clarified the distribution of loiasis in the Central African Republic and large parts of the Republic of Congo and the Democratic Republic of Congo for which hardly any information was available, and confirmed known loiasis foci. The new maps of the prevalence of eye worm and the probability that the prevalence exceeds the risk threshold of 40% provide critical information for ivermectin treatment programs among millions of people in Africa. PMID:21738809

  19. Animal Slurry Acidification Affects Particle Size Distribution and Improves Separation Efficiency.

    PubMed

    Regueiro, I; Pociask, M; Coutinho, J; Fangueiro, D

    2016-05-01

    Solid-liquid separation is performed to improve slurry management, and acidification of the slurry is used to reduce ammonia emissions. Acidification is known to affect slurry characteristics, and we hypothesized that it may affect mechanical separation. Our objective in this study was to assess the effects of slurry acidification on particle size distribution and separation efficiency. Two types of slurry, aged pig and fresh dairy, and two different acidification additives, sulfuric acid and aluminum sulfate (alum), were studied. We found that acidification with sulfuric acid promoted phosphorus (P) solubilization for both slurries, but no change was observed with alum. More ammonium was found in the acidified dairy slurry compared with raw dairy slurry, but no difference was found in aged pig slurry. Acidification before separation increased the proportion of the solid fraction in the slurries, and the effect was significantly higher with alum. When alum was used to acidify the slurries, the proportion of particles larger than 100 μm increased significantly, as did the P concentration in this particle size range. The efficiency of P separation increased markedly in both slurries when alum was used, with the removal to the solid fraction of the dairy slurry being almost complete (90%). Because the priority in mechanical separation is to increase the P content in the solid fraction, the use of alum before centrifugation may be the most suitable option for enhancing its nutrient content. We conclude that separation efficiency and particle size distribution are significantly affected by acidification, but the extent of the effects depends on slurry type and on the type of additive used for acidification. PMID:27136179

  20. Geographical distribution patterns and habitat suitability models for presence of host-seeking ixodid ticks in dense woodlands of Mendocino County, California.

    PubMed

    Eisen, L; Eisen, R J; Lane, R S

    2006-03-01

    We used drag sampling to examine the geographical distribution patterns of ixodid ticks engaging in open (non-nidicolous) host-seeking behavior in dense woodland habitats of the climatically and ecologically diverse Mendocino County in north coastal California. The findings based on this sampling methodology reflect risk of human exposure to host-seeking ticks rather than the true distribution of the ticks. Drag sampling in 78 sites yielded 7,860 nymphal or adult Ixodes pacificus Cooley & Kohls, 220 Dermacentor occidentalis Marx, 150 Ixodes spinipalpis Hadwen & Nuttall, 15 Hemaphysalis leporispalustris (Packard), 12 Ixodes angustus Neumann, 12 Ixodes auritulus Neumann, and a single Dermacentor variabilis (Say). I. pacificus, which is the primary vector of the Lyme disease spirochete Borrelia burgdorferi to humans in California, occurred in all 78 sites examined. D. occidentalis, another tick species commonly biting humans in California, and H. leporispalustris typically were encountered in oak-associated woodlands in the central or eastern parts of the county. In contrast, three species of Ixodes ticks (I. angustus, I. auritulus, and I. spinipalpis) most commonly were found questing openly in woodlands with redwood present in the western part of the county. I. angustus and I. spinipalpis are occasional human biters and known experimental vectors of B. burgdorferi. Our study represents the first collection of large numbers of openly host-seeking I. spinipalpis ticks. Univariate tests of associations between presence of ticks (D. occidentalis, H. leporispalustris, I. angustus, I. auritulus, or I. spinipalpis) and environmental geographical information systems-remote sensing (GIS/ RS)-based data indicated that elevation, number of growing degree-days, and tasseled cap brightness, greenness, and wetness are especially useful predictors of presence of openly hostseeking ticks. Combinations of the above-mentioned GIS/RS-based data yielded significant logistic regression

  1. Geostatistical mapping of effluent-affected sediment distribution on the Palos Verdes Shelf

    SciTech Connect

    Murray, Christopher J. ); Lee, H J.; Hampton, M A.

    2001-12-01

    Geostatistical techniques were used to study the spatial continuity of the thickness of effluent-affected sediment in the offshore Palos Verdes margin area. The thickness data were measured directly from cores and indirectly from high-frequency subbottom profiles collected over the Palos Verdes Margin. Strong spatial continuity of the sediment thickness data was identified, with a maximum range of correlation in excess of 1.4 km. The spatial correlation showed a marked anisotropy, and was more than twice as continuous in the alongshore direction as in the cross-shelf direction. Sequential indicator simulation employing models fit to the thickness data variograms was used to map the distribution of the sediment, and to quantify the uncertainty in those estimates. A strong correlation between sediment thickness data and measurements of the mass of the contaminant p,p?-DDE per unit area was identified. A calibration based on the bivariate distribution of the thickness and p,p?-DDE data was applied using Markov-Bayes indicator simulation to extend the geostatistical study and map the contamination levels in the sediment. Integrating the map grids produced by the geostatistical study of the two variables indicated that 7.8 million cubic meters of effluent-affected sediment exist in the map area, containing approximately 61 to 72 Mg (metric tons) of p,p?-DDE. Most of the contaminated sediment (about 85% of the sediment and 89% of the p,p?-DDE) occurs in water depths less than 100 m. The geostatistical study also indicated that the samples available for mapping are well distributed and the uncertainty of the estimates of the thickness and contamination level of the sediments is lowest in areas where the contaminated sediment is most prevalent.

  2. Hypoxia Affects Nitrogen Uptake and Distribution in Young Poplar (Populus × canescens) Trees

    PubMed Central

    Liu, Bin; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2015-01-01

    The present study with young poplar trees aimed at characterizing the effect of O2 shortage in the soil on net uptake of NO3- and NH4+ and the spatial distribution of the N taken up. Moreover, we assessed biomass increment as well as N status of the trees affected by O2 deficiency. For this purpose, an experiment was conducted in which hydroponically grown young poplar trees were exposed to hypoxic and normoxic (control) conditions for 14 days. 15N-labelled NO3- and NH4+ were used to elucidate N uptake and distribution of currently absorbed N and N allocation rates in the plants. Whereas shoot biomass was not affected by soil O2 deficiency, it significantly reduced root biomass and, consequently, the root-to-shoot ratio. Uptake of NO3- but not of NH4+ by the roots of the trees was severely impaired by hypoxia. As a consequence of reduced N uptake, the N content of all poplar tissues was significantly diminished. Under normoxic control conditions, the spatial distribution of currently absorbed N and N allocation rates differed depending on the N source. Whereas NO3- derived N was mainly transported to the younger parts of the shoot, particularly to the developing and young mature leaves, N derived from NH4+ was preferentially allocated to older parts of the shoot, mainly to wood and bark. Soil O2 deficiency enhanced this differential allocation pattern. From these results we assume that NO3- was assimilated in developing tissues and preferentially used to maintain growth and ensure plant survival under hypoxia, whereas NH4+ based N was used for biosynthesis of storage proteins in bark and wood of the trees. Still, further studies are needed to understand the mechanistic basis as well as the eco-physiological advantages of such differential allocation patterns. PMID:26308462

  3. [Vertical distribution of fuels in Pinus yunnanensis forest and related affecting factors].

    PubMed

    Wang, San; Niu, Shu-Kui; Li, De; Wang, Jing-Hua; Chen, Feng; Sun, Wu

    2013-02-01

    In order to understand the effects of fuel loadings spatial distribution on forest fire kinds and behaviors, the canopy fuels and floor fuels of Pinus yunnanensis forests with different canopy density, diameter at breast height (DBH), tree height, and stand age and at different altitude, slope grade, position, and aspect in Southwest China were taken as test objects, with the fuel loadings and their spatial distribution characteristics at different vertical layers compared and the fire behaviors in different stands analyzed. The relationships between the fuel loadings and the environmental factors were also analyzed by canonical correspondence analysis (CCA). In different stands, there existed significant differences in the vertical distribution of fuels. Pinus yunnanensis-Qak-Syzygium aromaticum, Pinus yunnanensis-oak, and Pinus yunnanensis forests were likely to occur floor fire but not crown fire, while Pinus yunnanensis-Platycladus orientalis, Pinus yunnanensis-Keteleeria fortune, and Keteleeria fortune-Pinus yunnanensis were not only inclined to occur floor fire, but also, the floor fire could be easily transformed into crown fire. The crown fuels were mainly affected by the stand age, altitude, DBH, and tree height, while the floor fuels were mainly by the canopy density, slope grade, altitude, and stand age. PMID:23705375

  4. Nearest Neighbor Interactions Affect the Conformational Distribution in the Unfolded State of Peptides

    NASA Astrophysics Data System (ADS)

    Toal, Siobhan; Schweitzer-Stenner, Reinhard; Rybka, Karin; Schwalbe, Hardol

    2013-03-01

    In order to enable structural predictions of intrinsically disordered proteins (IDPs) the intrinsic conformational propensities of amino acids must be complimented by information on nearest-neighbor interactions. To explore the influence of nearest-neighbors on conformational distributions, we preformed a joint vibrational (Infrared, Vibrational Circular Dichroism (VCD), polarized Raman) and 2D-NMR study of selected GxyG host-guest peptides: GDyG, GSyG, GxLG, GxVG, where x/y ={A,K,LV}. D and S (L and V) were chosen at the x (y) position due to their observance to drastically change the distribution of alanine in xAy tripeptide sequences in truncated coil libraries. The conformationally sensitive amide' profiles of the respective spectra were analyzed in terms of a statistical ensemble described as a superposition of 2D-Gaussian functions in Ramachandran space representing sub-ensembles of pPII-, β-strand-, helical-, and turn-like conformations. Our analysis and simulation of the amide I' band profiles exploits excitonic coupling between the local amide I' vibrational modes in the tetra-peptides. The resulting distributions reveal that D and S, which themselves have high propensities for turn-structures, strongly affect the conformational distribution of their downstream neighbor. Taken together, our results indicate that Dx and Sx motifs might act as conformational randomizers in proteins, attenuating intrinsic propensities of neighboring residues. Overall, our results show that nearest neighbor interactions contribute significantly to the Gibbs energy landscape of disordered peptides and proteins.

  5. Geographically distributed environmental sensor system

    DOEpatents

    French, Patrick; Veatch, Brad; O'Connor, Mike

    2006-10-03

    The present invention is directed to a sensor network that includes a number of sensor units and a base unit. The base station operates in a network discovery mode (in which network topology information is collected) in a data polling mode (in which sensed information is collected from selected sensory units). Each of the sensor units can include a number of features, including an anemometer, a rain gauge, a compass, a GPS receiver, a barometric pressure sensor, an air temperature sensor, a humidity sensor, a level, and a radiant temperature sensor.

  6. Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry.

    PubMed

    Tsirigotakis, Nikolaos; Christodoulou, Vasiliki; Ntais, Pantelis; Mazeris, Apostolos; Koutala, Eleni; Messaritakis, Ippokratis; Antoniou, Maria

    2016-05-01

    Leishmaniasis, a neglected vector-borne disease caused by the protozoan parasite Leishmania, is encountered in 98 countries causing serious concerns to public health. The most alarming is the development of parasite drug resistance, a phenomenon increasingly encountered in the field rendering chemotherapy ineffective. Although resistance to drugs is a complex phenomenon, the rate of efflux of the fluorescent dye Rhodamine-123 from the parasite body, using flow cytometry, is an indication of the isolate's ability to efflux the drug, thus avoiding death. The rate of efflux measured 275 Leishmania strains, isolated from patients and dogs from Greece and Cyprus, was measured and mapped to study the geographical distribution of the multidrug resistance (MDR) gene expression as an indication of the drug resistance of the parasite. The map showed that out of the seven prefectures, where dogs presented high efflux rates, five also had patients with high efflux rates. In one, out of the 59 prefectures studied, the highest number of isolates with efflux slope α > 1, in both human and dog isolates, was found; a fact which may suggest that spread of drug resistance is taking place. The virulence of the Leishmania strains, assessed after infecting human macrophages of the THP-1 cell line, fluctuated from 1% to 59.3% with only 2.5% of the isolates showing infectivity > 50%. The most virulent strains were isolated from Attica and Crete. PMID:27001764

  7. Spatial analysis of lymphatic filariasis distribution in the Nile Delta in relation to some environmental variables using geographic information system technology.

    PubMed

    Hassan, A N; Dister, S; Beck, L

    1998-04-01

    Geographic information system (GIS) was used to analyze the spatial distribution of filariasis in the Nile Delta. The study involved 201 villages belonging to Giza, Qalubiya, Monoufiya, Gharbiya, and Dakahliya governorates. Villages with similar microfilarial (mf) prevalence rates were observed to cluster within 1-2 km distance, then, clustering started to decrease significantly with distance up to 5 km (Pearson correlation coefficient = -0.98). the likelihood of negative and high prevalence villages being contiguous was very low (approximately 1.8%, n = 612 village-pairs) indicating homogeneity in disease processes within the defined spatial scales. Of the villages located within 2 km from the main Nile branches (n = 46), 95% exhibited low prevalence. In addition, the spatial pattern of mf prevalence was shown to be negatively associated with annual rainfall and relative humidity, while it was positively associated with annual daily temperature. Average mf prevalence in warmer, relatively drier areas receiving 25 mm of rain was significantly higher (3.9%) than that in less warmer but more humid areas receiving 50 mm of rain (1.6%) (P < 0.0001). Based on the results of the present study, GIS was used to generate a "filariasis risk map" that could be used by health authorities to efficiently direct surveillance and control efforts. This investigation identified some of the factors underlying filariasis spatial pattern, quantified clustering and demonstrated the potential of GIS application in vector-borne disease epidemiology. PMID:9617048

  8. Geographic distribution, age pattern and sites of lesions in a cohort of Buruli ulcer patients from the Mapé Basin of Cameroon.

    PubMed

    Bratschi, Martin W; Bolz, Miriam; Minyem, Jacques C; Grize, Leticia; Wantong, Fidèle G; Kerber, Sarah; Njih Tabah, Earnest; Ruf, Marie-Thérèse; Mou, Ferdinand; Noumen, Djeunga; Um Boock, Alphonse; Pluschke, Gerd

    2013-01-01

    Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake. PMID:23785529

  9. Geographic Distribution, Age Pattern and Sites of Lesions in a Cohort of Buruli Ulcer Patients from the Mapé Basin of Cameroon

    PubMed Central

    Bratschi, Martin W.; Bolz, Miriam; Minyem, Jacques C.; Grize, Leticia; Wantong, Fidèle G.; Kerber, Sarah; Njih Tabah, Earnest; Ruf, Marie-Thérèse; Mou, Ferdinand; Noumen, Djeunga; Um Boock, Alphonse; Pluschke, Gerd

    2013-01-01

    Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake. PMID:23785529

  10. Anal human papillomavirus genotype distribution in HIV-infected men who have sex with men by geographical origin, age, and cytological status in a Spanish cohort.

    PubMed

    Torres, Montserrat; González, Cristina; del Romero, Jorge; Viciana, Pompeyo; Ocampo, Antonio; Rodríguez-Fortúnez, Patricia; Masiá, Mar; Blanco, José Ramón; Portilla, Joaquín; Rodríguez, Carmen; Hernández-Novoa, Beatriz; del Amo, Julia; Ortiz, Marta

    2013-11-01

    Knowledge of human papillomavirus (HPV) type distribution in populations at risk for anal cancer is needed. Here, we describe the anal HPV genotype distribution in a large Spanish cohort (Cohort of the Spanish HIV Research Network HPV [CoRIS-HPV]) of HIV-positive men who have sex with men (MSM) according to geographical origin, age, and cytological status. A cross-sectional analysis of baseline data from 1,439 HIV-infected MSM (2007 to 2012) was performed. Anal HPV genotyping was performed using the Linear Array HPV genotyping test. Descriptive analyses of subject characteristics, prevalences, and 95% confidence intervals (CI) were performed. The global prevalences of HPV, high-risk HPV (HR-HPV), and low-risk HPV (LR-HPV) types were 95.8%, 83.0%, and 72.7%, respectively. Among the HR-HPV types, HPV16 was the most common, followed by HPV59, -39, -51, -18, and -52. The prevalence of multiple HR-HPV infections was 58.5%. There were no differences in the crude analyses between Spanish and Latin-American MSM for most HPV types, and a peak in prevalence for most HPV types was seen in patients in their late thirties. Globally and by specific HPV groups, men with abnormal anal cytologies had a higher prevalence of infection than those with normal cytologies. This study has the largest number of HIV-positive MSM with HPV genotype data analyzed according to cytological status as far as we know. The information gained from this study can help with the design of anal cancer prevention strategies in HIV-positive patients. PMID:23966501

  11. Use of a climatic rule and fuzzy sets to model geographic distribution of climatic risk for European canker (Neonectria galligena) of apple.

    PubMed

    Kim, Kwang Soo; Beresford, Robert M

    2012-02-01

    A rule-based model was developed to assess climatic risk of European canker (Neonectria galligena), which is a major disease of apple in some temperate zones. A descriptive rule was derived from published observations on climatic conditions favorable for European canker development. Fuzzy set theory was used to evaluate the descriptive rule quantitatively. The amount and frequency of rainfall and the average number of hours between 11 and 16°C/day were used as input variables whose values were matched with terms in the rule, e.g., 'high' or 'low'. The degree of a term, e.g., the state of being high or low, to a given input value was determined using a membership function that converts an input value to a number between 0 and 1. The rule was evaluated by combining the degree of the terms associated with monthly climate data. Monthly risk index values derived using the rule were combined for pairs of consecutive months over 12 months. The annual risk of European canker development was represented by the maximum risk index value for 2 months combined. The membership function parameters were adjusted iteratively to achieve a specified level of risk at Talca (Chile), Loughgall (Northern Ireland), East Malling (UK), and Sebastopol (USA), where European canker risk was known. The rule-based model was validated with data collected from Canada, Ecuador, Denmark, Germany, Norway, Poland, Sweden, the Netherlands, New Zealand, and the Pacific Northwest (USA), where European canker has been reported to occur. In these validation areas, the model's risk prediction agreed with reports of disease occurrence. The rule-based model also predicted high risk areas more reliably than the climate matching model, CLIMEX, which relies on correlations between the spatial distribution of a species and climatic conditions. The combination of a climatic rule and fuzzy sets could be used for other applications where prediction of the geographic distribution of organisms is required for

  12. Anal Human Papillomavirus Genotype Distribution in HIV-Infected Men Who Have Sex with Men by Geographical Origin, Age, and Cytological Status in a Spanish Cohort

    PubMed Central

    Torres, Montserrat; González, Cristina; del Romero, Jorge; Viciana, Pompeyo; Ocampo, Antonio; Rodríguez-Fortúnez, Patricia; Masiá, Mar; Blanco, José Ramón; Portilla, Joaquín; Rodríguez, Carmen; Hernández-Novoa, Beatriz; del Amo, Julia

    2013-01-01

    Knowledge of human papillomavirus (HPV) type distribution in populations at risk for anal cancer is needed. Here, we describe the anal HPV genotype distribution in a large Spanish cohort (Cohort of the Spanish HIV Research Network HPV [CoRIS-HPV]) of HIV-positive men who have sex with men (MSM) according to geographical origin, age, and cytological status. A cross-sectional analysis of baseline data from 1,439 HIV-infected MSM (2007 to 2012) was performed. Anal HPV genotyping was performed using the Linear Array HPV genotyping test. Descriptive analyses of subject characteristics, prevalences, and 95% confidence intervals (CI) were performed. The global prevalences of HPV, high-risk HPV (HR-HPV), and low-risk HPV (LR-HPV) types were 95.8%, 83.0%, and 72.7%, respectively. Among the HR-HPV types, HPV16 was the most common, followed by HPV59, -39, -51, -18, and -52. The prevalence of multiple HR-HPV infections was 58.5%. There were no differences in the crude analyses between Spanish and Latin-American MSM for most HPV types, and a peak in prevalence for most HPV types was seen in patients in their late thirties. Globally and by specific HPV groups, men with abnormal anal cytologies had a higher prevalence of infection than those with normal cytologies. This study has the largest number of HIV-positive MSM with HPV genotype data analyzed according to cytological status as far as we know. The information gained from this study can help with the design of anal cancer prevention strategies in HIV-positive patients. PMID:23966501

  13. Scale-dependent factors affecting North American river otter distribution in the midwest

    USGS Publications Warehouse

    Jeffress, Mackenzie R.; Paukert, C.P.; Whittier, Joanna B.; Sandercock, B.K.; Gipson, P.S.

    2011-01-01

    The North American river otter (Lontra canadensis) is recovering from near extirpation throughout much of its range. Although reintroductions, trapping regulations and habitat improvements have led to the reestablishment of river otters in the Midwest, little is known about how their distribution is influenced by local- and landscape-scale habitat. We conducted river otter sign surveys from Jan. to Apr. in 2008 and 2009 in eastern Kansas to assess how local- and landscape-scale habitat factors affect river otter occupancy. We surveyed three to nine 400-m stretches of stream and reservoir shorelines for 110 sites and measured local-scale variables (e.g., stream order, land cover types) within a 100 m buffer of the survey site and landscape-scale variables (e.g., road density, land cover types) for Hydrological Unit Code 14 watersheds. We then used occupancy models that account for the probability of detection to estimate occupancy as a function of these covariates using Program PRESENCE. The best-fitting model indicated river otter occupancy increased with the proportion of woodland cover and decreased with the proportion of cropland and grassland cover at the local scale. Occupancy also increased with decreased shoreline diversity, waterbody density and stream density at the landscape scale. Occupancy was not affected by land cover or human disturbance at the landscape scale. Understanding the factors and scale important to river otter occurrence will be useful in identifying areas for management and continued restoration. ?? 2011, American Midland Naturalist.

  14. Anthropogenic lead distribution in rodent-affected and undisturbed soils in southern California

    SciTech Connect

    Mace, J.E.; Graham, R.C.; Amrhein, C.

    1997-01-01

    Anthropogenic Pb is the world`s largest and most widespread heavy metal contamination. Inspired by recent evidence suggesting a faster redistribution of Pb through the mineral soil profile than was previously expected, we investigated the effects of rodent activity on Pb redistribution. Total Pb was analyzed at the 0-1, 1-4, and 4-7-cm depths in a rodent-affected soil and in an undisturbed soil, in the same proximity and with the same parent material, in the Box Springs Mountains near Riverside, California. Six replicate sites of each condition were sampled. Lead was recovered by a digest in 4 M HNO{sub 3} and measured using a graphite furnace atomic absorption spectrophotometer. Anthropotenic Pb content to a 7-cm depth averaged 19 mg kg{sup -1} in undisturbed soils and 10 mg kg{sup -1} in rodent-affected soils. In both soils, the highest concentrations of Pb were located in the top 4 cm of the profile. After accounting for an estimated native Pb ({approximately}3.3 mg kg{sup -1}), we determined that 20 to 38 kg ha{sup -1} Pb has been deposited on these soils, through air pollution. Our findings suggest rodents significantly modify the distribution of anthropogenic Pb in the rodent-affected soils of the box Springs Mountains primarily in two ways: (i) by reducing Pb concentration in surface soils, thereby decreasing the potential for erosional redistribution of Pb, and (ii) by decreasing Pb transport time through the soil profile as a result of physical mixing. This redistribution mechanism is likely applicable to other surface deposited anthropogenic contaminants that have similarly low soil mobility. 18 refs., 1 fig., 2 tabs.

  15. Coal fly ash effluent affects the distributions of Brachionus calyciflorus sibling species.

    PubMed

    Zhang, Gen; Xi, Yi-Long; Xue, Ying-Hao; Xiang, Xian-Ling; Wen, Xin-Li

    2015-02-01

    Fly ash, a coal combustion residue of thermal power plants and a source of multiple pollutants, has been recognized as an environmental hazard all over the world. Although it is known that fly ash effluent affects density, diversity and distribution of rotifers in drainage systems and receiving water bodies, the effect of fly ash effluent on the distributions of highly similar rotifer species remains unknown. In this study, the mtDNA COI genes of 90 individuals in Brachionus calyciflorus complex from Lake Hui (as a fly ash discharge water pond) and other two neighboring lakes (Lake Fengming and Lake Tingtang) were sequenced and analyzed, and the responses in selected life table demographic parameters (life expectancy at hatching, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring) of different rotifer populations to fly ash effluent were investigated. Overall, 72 mtDNA haplotypes were defined, and were split into two clades by the phylogenetic trees. The divergence of COI gene sequences between the two clades ranged from 11.8% to17.8%, indicating the occurrence of two sibling species (sibling species I and sibling species II). Sibling species I distributed in all the three lakes, showing strong capabilities for dispersal and colonization, which were supported by its higher level of gene flow (2.60-4.04) between the populations from Lake Hui and each of the other two lakes, longer life expectancy at hatching (101.6-148.2 h), and higher net reproductive rate (4.4-16.4 offspring/female) and intrinsic rate of population increase (0.60-0.98/d) when cultured in aerated tap water and fly ash effluent. Sibling species II distributed in both Lake Tingtang and Lake Fengming, showing that its dispersal existed between the two lakes. Considering that the distance between Lake Hui and Lake Fengming is shorter than that between Lake Tingtang and Lake Fengming, sibling species II is able to disperse at least from Lake Fengming to Lake

  16. Factors affecting the distribution of hydrocarbon contaminants and hydrogeochemical parameters in a shallow sand aquifer.

    PubMed

    Lee, J Y; Cheon, J Y; Lee, K K; Lee, S Y; Lee, M H

    2001-07-01

    The distributions of hydrocarbon contaminants and hydrogeochemical parameters were investigated in a shallow sand aquifer highly contaminated with petroleum hydrocarbons leaked from solvent storage tanks. For these purposes, a variety of field investigations and studies were performed, which included installation of over 100 groundwater monitoring wells and piezometers at various depths, soil logging and analyses during well and piezometer installation, chemical analysis of groundwater, pump tests, and slug tests. Continuous water level monitoring at three selected wells using automatic data-logger and manual measuring at other wells were also conducted. Based on analyses of the various investigations and tests, a number of factors were identified to explain the distribution of the hydrocarbon contaminants and hydrogeochemical parameters. These factors include indigenous biodegradation, hydrostratigraphy, preliminary pump-and-treat remedy, recharge by rainfall, and subsequent water level fluctuation. The permeable sandy layer, in which the mean water table elevation is maintained, provided a dominant pathway for contaminant transport. The preliminary pump-and-treat action accelerated the movement of the hydrocarbon contaminants and affected the redox evolution pattern. Seasonal recharge by rain, together with indigenous biodegradation, played an important role in the nat