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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. 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...

  4. 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....

  5. Abundance and Distribution of Geographically Isolated ...

    EPA Pesticide Factsheets

    Geographically isolated wetlands (GIWS) are important landscape elements involved in hydrologic, biogeochemical, and biological functioning. Their influence, under certain circumstances, can significantly affect other waters of the Unites States. However, there have been no data-based estimates of the abundance of GIWs at national scales in the US, frustrating efforts to properly manage the resource. We applied a distance-based floodplain and riparian zone proxy to existing data layers from the National Hydrography Dataset (1:24,000k) and applied a geospatial buffering process to National Wetlands Inventory data to quantify the abundance of connected wetlands at significant and relevant scales. Our analyses suggest GIWs are prevalent throughout the conterminous United States, with exceptional densities in portions of the Gulf and Atlantic Coastal Plains, the Prairie Pothole Region of the Upper Midwest, and significant densities elsewhere. Indeed, over 65,000 km2 of GIWs may exist. We provide further analyses of the types, distributions, and regional extent of these systems. Lastly, we also explore additional connectivity measures associated with adjacency and relative geographic isolation to floodplains and other elements of the hydrologic landscape. Presentation at INTECOL International Wetlands Conference (Changshu, China; Sept. 2016)

  6. 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

  7. 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…

  8. Distributed Object Oriented Geographic Information System

    SciTech Connect

    Lurie, Gordon R.

    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 for 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.

  9. DOOGIS. Distributed Object Oriented Geographic Information System

    SciTech Connect

    Lurie, G.

    1995-06-01

    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 for 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.

  10. Geographic distribution of patients affected by Cryptococcus neoformans/Cryptococcus gattii species complexes meningitis, pigeon and tree populations in Southern Brazil.

    PubMed

    Spina-Tensini, Tallulah; Muro, Marisol Dominguez; Queiroz-Telles, Flávio; Strozzi, Isabella; Moraes, Samia Talise; Petterle, Ricardo Rasmussen; Vettorello, Marcelo; Staudacher, Claudia; Miguez, Luiz Alberto Lopes; de Almeida, Sérgio Monteiro

    2017-01-01

    Cryptococcal meningitis is mainly caused by members of the C. neoformans/C. gattii species complexes. The ecological niches of Cryptococcus species have extensively been studied, but its epidemiological relationship with meningitis cases is still unknown. In this study, we estimate the relationship between cryptococcal meningitis cases and tree and pigeon populations, the classical niches of members of C. neoformans/C. gattii sensu lato. We analysed the records of every patient whose cerebrospinal fluid culture yielded Cryptococcus spp. during the last 30 years at Clinical Hospital of Curitiba. Data about Curitiba's pigeon and tree distribution were obtained from Curitiba's Secretaries of Zoonosis and Environment archives. We used ArcGis9 software to plot the distribution of the pigeon and tree populations in this city as well as cryptococcal meningitis cases, distinguishing them according to the causal agent in C. neoformans or C. gattii s.l. In total, 489 cryptococcal cultures were documented, with 140 corresponding to patients eligible for this study (134 affected by C. neoformans s.l. and 6 by C. gattii s.l.). The map showed a relationship between C. neoformans s.l. patients and pigeon population. C. gattii s.l. patients were associated with neither tree nor pigeon populations, but lived close to large unbuilt, unforested areas.

  11. Environmental factors affecting survival of immature Ixodes scapularis and implications for geographical distribution of lyme disease: The climate/behavior hypothesis

    USGS Publications Warehouse

    Ginsberg, Howard; Albert, Marisa; Acevedo, Lixis; Dyer, Megan C.; Arsnoe, Isis M.; Tsao, Jean I.; Mather, Thomas N.; LeBrun, Roger A.

    2017-01-01

    implications for the effect of climate change on the future distribution of Lyme disease.

  12. Environmental Factors Affecting Survival of Immature Ixodes scapularis and Implications for Geographical Distribution of Lyme Disease: The Climate/Behavior Hypothesis

    PubMed Central

    Albert, Marisa; Acevedo, Lixis; Dyer, Megan C.; Arsnoe, Isis M.; Tsao, Jean I.; Mather, Thomas N.; LeBrun, Roger A.

    2017-01-01

    implications for the effect of climate change on the future distribution of Lyme disease. PMID:28076359

  13. Optimization of tomographic reconstruction workflows on geographically distributed resources

    DOE PAGES

    Bicer, Tekin; Gursoy, Doga; Kettimuthu, Rajkumar; ...

    2016-01-01

    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) modelingmore » 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

  14. Optimization of tomographic reconstruction workflows on geographically distributed resources

    PubMed Central

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

    2016-01-01

    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

  15. 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.

  16. Comprehensive monitoring for heterogeneous geographically distributed storage

    SciTech Connect

    Ratnikova, Natalia; Karavakis, E.; Lammel, S.; Wildish, Tony

    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 study, we discuss the functionality and our experience of system deployment and operation on the full CMS scale.

  17. 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.

  18. Comprehensive monitoring for heterogeneous geographically distributed storage

    DOE PAGES

    Ratnikova, Natalia; Karavakis, E.; Lammel, S.; ...

    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.more » In this study, we discuss the functionality and our experience of system deployment and operation on the full CMS scale.« less

  19. Incidence and Geographic Distribution of Succinic Semialdehyde Dehydrogenase (SSADH) Deficiency.

    PubMed

    Attri, Savita Verma; Singhi, Pratibha; Wiwattanadittakul, Natrujee; Goswami, Jyotindra N; Sankhyan, Naveen; Salomons, Gajja S; Roullett, Jean-Baptiste; Hodgeman, Ryan; Parviz, Mahsa; Gibson, K Michael; Pearl, Phillip L

    2016-11-05

    The incidence of succinic semialdehyde dehydrogenase (SSADH) deficiency, an autosomal recessive inherited disorder of GABA degradation, is unknown. Upon a recent diagnosis of a new family of affected fraternal twins from the Punjabi ethnic group of India, case ascertainment from the literature and our database was done to determine the number of confirmed cases along with their geographic distribution. The probands presented with global developmental delay, infantile onset epilepsy, and a persistent neurodevelopmental disorder upon diagnosis at 10 years of age with intellectual disability, expressive aphasia, and behavioral problems most prominent for hyperactivity. Gamma-hydroxybutyric aciduria and homozygous ALDH5A1 c.608C>T; p.Pro203Leu mutations were confirmed. Identification of all available individual cases with clinical details available including geographic or ethnic origin revealed 182 patients from 40 countries, with the largest number of patients reported from the USA (24%), Turkey (10%), China (7%), Saudi Arabia (6%), and Germany (5%). This study provides an accounting of all published cases of confirmed SSADH deficiency and provides data useful in planning further studies of this rare inborn error of metabolism.

  20. Optimization of tomographic reconstruction workflows on geographically distributed resources

    SciTech Connect

    Bicer, Tekin; Gursoy, Doga; Kettimuthu, Rajkumar; De Carlo, Francesco; Foster, Ian T.

    2016-01-01

    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

  1. Geographic prioritization of distributing pandemic influenza vaccines.

    PubMed

    Araz, Ozgur M; Galvani, Alison; Meyers, Lauren A

    2012-09-01

    Pandemic influenza is an international public health concern. In light of the persistent threat of H5N1 avian influenza and the recent pandemic of A/H1N1swine influenza outbreak, public health agencies around the globe are continuously revising their preparedness plans. The A/H1N1 pandemic of 2009 demonstrated that influenza activity and severity might vary considerably among age groups and locations, and the distribution of an effective influenza vaccine may be significantly delayed and staggered. Thus, pandemic influenza vaccine distribution policies should be tailored to the demographic and spatial structures of communities. Here, we introduce a bi-criteria decision-making framework for vaccine distribution policies that is based on a geospatial and demographically-structured model of pandemic influenza transmission within and between counties of Arizona in the Unites States. Based on data from the 2009-2010 H1N1 pandemic, the policy predicted to reduce overall attack rate most effectively is prioritizing counties expected to experience the latest epidemic waves (a policy that may be politically untenable). However, when we consider reductions in both the attack rate and the waiting period for those seeking vaccines, the widely adopted pro rata policy (distributing according to population size) is also predicted to be an effective strategy.

  2. [Geographical distribution of physicians in Chile].

    PubMed

    Goic, A

    1995-03-01

    In 1994, Chile had 15,451 active physicians (less than 70 years old) for a population of 14,027,344 with a ratio of 1 physician per 908 inhabitants, a satisfactory figure compared to other countries of similar socio-economical development. Ratios of 1:880 and 1:843 are projected for 1999 and 2004 respectively. The annual rate of physician's population growth (2.2%), that is superior to the general population's growth rate (1.6%), will increase to about 2.5% per annum in 2001 as a consequence of the creation of three new medical schools. However, the distribution of physicians along the country is unsatisfactory. While the capital (Metropolitan Region) has a ratio of 1 physician per 629 inhabitants, the figure for the Region of Maule is 1:2,113. Only two of ten regions, excepting the capital, have a ratio lower than 1:1,000. Sixty percent of physicians live in Santiago while only 40% of the general population does so, illustrating their high concentration. Median ratio in Chile, that better reflects the reality than the mean, is 1:1,280. The heterogeneous distribution of physicians in Chile is a sign of social inequity that must be corrected. In a free society a better physician distribution is achieved with economical and professional incentives given by health institutions.

  3. Geographical distribution of Musa gracilis Holttum in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Norfazlina, B.; Wickneswari, R.; Choong, C. Y.

    2016-11-01

    Musa gracilis (Musaceae) is placed under section Callimusa and was considered endemic to Peninsular Malaysia. The objective of this study was to evaluate the current occurrence of Musa gracilis in Peninsular Malaysia. The coordinates of each population was recorded using the Global Positioning System (GPS) and mapped to show the geographical distribution of Musa gracilis. This study revealed that Musa gracilis exhibits specific pattern of distribution, which exists only in a lowland areas on the eastern and southern part of Peninsular Malaysia.

  4. Geographic distribution of postgraduate dental trainees in Japan.

    PubMed

    Hirata, SoIchiro; Mataki, Shiro; Akiyama, Hitoshi; Nitta, Hiroshi; Okada, Mahito; Sakayori, Takaharu; Sugito, Hiroki; Ishii, Takuo

    2009-05-01

    Postgraduate clinical training for dentists in Japan became mandatory in April 2006. Mandatory postgraduate clinical training for physicians has been criticized as having accelerated the imbalance in distribution of physicians. This suggests the danger that the same phenomenon might occur in distribution of dentists. It is also necessary to investigate the geographic distribution of dental trainees and practicing dentists in Japan. In this study, the number of dental trainees enrolled in each clinical training program and number that had actually received clinical training at each facility were compared by prefecture. The results suggest that disparities in the number of dental trainees among prefectures are being compensated for by movement across prefectural borders under the clinical training facilities-group system. Postgraduate dental trainees, however, showed a significantly greater imbalance in geographic distribution than practicing dentists. Continuation of the postgraduate clinical training for dentists under the existing system may accelerate this imbalance in distribution of dentists. To prevent this, practical measures should be taken in accordance with the coming review of the system, based on research regarding changes in geographic distribution of dental trainees.

  5. 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

  6. Check list and geographical distribution of phlebotomine sandflies in China.

    PubMed

    Leng, Y J; Zhang, L M

    1993-02-01

    A total of 42 species of sandflies, included in five genera, have been recorded from 31 of 32 provinces, municipalities and autonomous regions of China (excluding Heilongjiang Province). Five species, namely Phlebotomus alexandri, P. chinensis, P. longiductus, P. sichuanensis and P. smirnovi (syn. P. wui), are known to be vectors of human leishmaniasis. A list of these 42 phlebotomines is given, and their geographical distributions in China are described.

  7. Analysis of Geographical Distribution Patterns in Plants Using Fractals

    NASA Astrophysics Data System (ADS)

    Bari, A.; Ayad, G.; Padulosi, S.; Hodgkin, T.; Martin, A.; Gonzalez-Andujar, J. L.; Brown, A. H. D.

    Geographical distribution patterns in plants have been observed since primeval times and have been used by plant explorers to trace the origin of plants species. These patterns embody the effects of fundamental law-like processes. Diversity in plants has also been found to be proportionate with the area, and this scaling behavior is also known as fractal behavior. In the present study, we use fractal geometry to analyze the distribution patterns of wild taxa of cowpea with the objective to locate where their diversity would be the highest to aid in the planning of targeted explorations and conservation measures.

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

    PubMed

    Judkins, David C

    2014-12-16

    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

  9. Geographic distribution of haplotype diversity at the bovine casein locus

    PubMed Central

    Jann, Oliver C; Ibeagha-Awemu, Eveline M; Özbeyaz, Ceyhan; Zaragoza, Pilar; Williams, John L; Ajmone-Marsan, Paolo; Lenstra, Johannes A; Moazami-Goudarzi, Katy; Erhardt, Georg

    2004-01-01

    The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1*C-CSN2*A2-CSN3*AI/CSN3*H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed. PMID:15040901

  10. 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

  11. Geographical distribution of Taenia asiatica and related species.

    PubMed

    Eom, Keeseon S; Jeon, Hyeong-Kyu; Rim, Han-Jong

    2009-10-01

    Geographical information of Taenia asiatica is reviewed together with that of T. solium and T. saginata. Current distribution of T. asiatica was found to be mostly from Asian countries: the Republic of Korea, China, Taiwan, Indonesia, and Thailand. Molecular genotypic techniques have found out more countries with T. asiatica from Japan, the Philippines, and Vietnam. Specimens used in this paper were collected from around the world and mostly during international collaboration projects of Korean foundations for parasite control activities (1995-2009) in developing countries.

  12. The Geographical Distribution and Burden of Trachoma in Africa

    PubMed Central

    Smith, Jennifer L.; Flueckiger, Rebecca M.; Hooper, Pamela J.; Polack, Sarah; Cromwell, Elizabeth A.; Palmer, Stephanie L.; Emerson, Paul M.; Mabey, David C. W.; Solomon, Anthony W.; Haddad, Danny; Brooker, Simon J.

    2013-01-01

    Background There remains a lack of epidemiological data on the geographical distribution of trachoma to support global mapping and scale up of interventions for the elimination of trachoma. The Global Atlas of Trachoma (GAT) was launched in 2011 to address these needs and provide standardised, updated and accessible maps. This paper uses data included in the GAT to describe the geographical distribution and burden of trachoma in Africa. Methods Data assembly used structured searches of published and unpublished literature to identify cross-sectional epidemiological data on the burden of trachoma since 1980. Survey data were abstracted into a standardised database and mapped using geographical information systems (GIS) software. The characteristics of all surveys were summarized by country according to data source, time period, and survey methodology. Estimates of the current population at risk were calculated for each country and stratified by endemicity class. Results At the time of writing, 1342 records are included in the database representing surveys conducted between 1985 and 2012. These data were provided by direct contact with national control programmes and academic researchers (67%), peer-reviewed publications (17%) and unpublished reports or theses (16%). Prevalence data on active trachoma are available in 29 of the 33 countries in Africa classified as endemic for trachoma, and 1095 (20.6%) districts have representative data collected through population-based prevalence surveys. The highest prevalence of active trachoma and trichiasis remains in the Sahel area of West Africa and Savannah areas of East and Central Africa and an estimated 129.4 million people live in areas of Africa confirmed to be trachoma endemic. Conclusion The Global Atlas of Trachoma provides the most contemporary and comprehensive summary of the burden of trachoma within Africa. The GAT highlights where future mapping is required and provides an important planning tool for scale

  13. [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.

  14. Rapoport's rule revisited: geographical distributions of human languages.

    PubMed

    Gavin, Michael C; Stepp, John Richard

    2014-01-01

    One of the most well studied ecological patterns is Rapoport's rule, which posits that the geographical extent of species ranges increases at higher latitudes. However, studies to date have been limited in their geographic scope and results have been equivocal. In turn, much debate exists over potential links between Rapoport's rule and latitudinal patterns in species richness. Humans collectively speak nearly 7000 different languages, which are spread unevenly across the globe, with loci in the tropics. Causes of this skewed distribution have received only limited study. We analyze the extent of Rapoport's rule in human languages at a global scale and within each region of the globe separately. We test the relationship between Rapoport's rule and the richness of languages spoken in different regions. We also explore the frequency distribution of language-range sizes. The language-range area distribution is strongly right-skewed, with 87% of languages having range areas less than 10,000 km(2), and only nine languages with range areas over 1,000,000 km(2). At a global scale, language-range extents and areas are positively correlated with latitude. At a global scale and in five of the six regions examined, language-range extent and language-range area are strongly correlated with language richness. Our results point to group boundary formation as a critical mediator of the relationship between Rapoport's rule and diversity patterns. Where strong group boundaries limit range overlap, as is the case with human languages, and range sizes increase with latitude, latitudinal richness gradients may result.

  15. Rapoport's Rule Revisited: Geographical Distributions of Human Languages

    PubMed Central

    Gavin, Michael C.; Stepp, John Richard

    2014-01-01

    One of the most well studied ecological patterns is Rapoport's rule, which posits that the geographical extent of species ranges increases at higher latitudes. However, studies to date have been limited in their geographic scope and results have been equivocal. In turn, much debate exists over potential links between Rapoport's rule and latitudinal patterns in species richness. Humans collectively speak nearly 7000 different languages, which are spread unevenly across the globe, with loci in the tropics. Causes of this skewed distribution have received only limited study. We analyze the extent of Rapoport's rule in human languages at a global scale and within each region of the globe separately. We test the relationship between Rapoport's rule and the richness of languages spoken in different regions. We also explore the frequency distribution of language-range sizes. The language-range area distribution is strongly right-skewed, with 87% of languages having range areas less than 10,000 km2, and only nine languages with range areas over 1,000,000 km2. At a global scale, language-range extents and areas are positively correlated with latitude. At a global scale and in five of the six regions examined, language-range extent and language-range area are strongly correlated with language richness. Our results point to group boundary formation as a critical mediator of the relationship between Rapoport's rule and diversity patterns. Where strong group boundaries limit range overlap, as is the case with human languages, and range sizes increase with latitude, latitudinal richness gradients may result. PMID:25216049

  16. Geographical distribution of tetanus in the world, 1951-60

    PubMed Central

    Bytchenko, B.

    1966-01-01

    The introduction of tetanus toxoid about three decades ago, which was followed in many parts of the world by programmes of immunization of the population, has contributed greatly to the control of tetanus in the developed countries. Nevertheless, during the decade 1951-60, tetanus remained an unsolved problem in many of the developing countries. In the present report, it is shown, on the basis of the available literature and WHO statistics, that tetanus causes more than 50 000 deaths each year all over the world. Indeed, this figure should be regarded as an underestimate, since it only partially reflects the actual situation in the developing countries. The paper draws attention to the geographical distribution of tetanus in the world and indicates that existing ”foci” or ”zones” of infection may be attributed to environmental conditions as well as to social, economic and cultural factors. PMID:5325628

  17. 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

  18. 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.

  19. 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.

  20. 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.

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

    USGS Publications Warehouse

    Morrison, M.L.; Hahn, D.C.; George, T. Luke; Dobkin, David S.

    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

  2. Geographical differences in the distribution of malignant tumours*

    PubMed Central

    Chaklin, A. V.

    1962-01-01

    Malignant tumours are encountered among all races and in every type of geographical zone, but there are marked differences in different areas in the prevalence of particular forms of tumour—differences that are to a greater or lesser extent dependent on factors such as the climate and geography of the region and the habits, customs and occupations of the people. The study of these factors in relation to the occurrence of malignant tumours is of great importance in reaching an understanding of the etiology of tumours in man. In this paper the author discusses the many problems involved in the study of regional features in the prevalence of malignant tumours, with special reference to the difficulties of ensuring comparability of the data from widely differing regions and population groups. He concludes the paper with a review of some known facts regarding the distribution of malignant tumours at various sites in which he compares data obtained in surveys in the USSR with those obtained in other countries. PMID:14019866

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

    PubMed

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

    2014-01-28

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

  4. Visualizing nursing workforce distribution: policy evaluation using geographic information systems.

    PubMed

    Courtney, Karen L

    2005-12-01

    Health services literature suggests that geographic information systems (GIS) are useful policy evaluation tools when policy success is dependent on location. Nursing workforce distribution is an inherently local issue and nursing shortages present serious concerns for local, state and national governments. In 1991, Missouri enacted a nurse recruitment and retention policy targeting underserved (HPSA-designated) counties. Following Institutional Review Board approval, policy effectiveness was explored using a combination of GIS data visualization, spatial and classic statistics. Results of both data visualization and statistical methods do not demonstrate an expected trend of decreasing group differences between HPSA and non-HPSA-designated counties over time. Only two of the five time periods studied had significant group differences. Between 1993 and 1995, the loss in nurse to population ratios in HPSA counties was significant (U=1020, p<0.001); however, between 1999 and 2001, the growth in nurse to population ratio changes in HPSA counties was significant (U=1032, p=0.001). The GIS data visualization and statistical techniques performed suggest that current policy definitions of underserved areas may not be effective in defining areas of nursing shortages and the existing policy implementation may not be achieving the stated goals.

  5. Geographical Patterns in Cyanobacteria Distribution: Climate Influence at Regional Scale

    PubMed Central

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

    2014-01-01

    Cyanobacteria are a component of public health hazards in freshwater environments because of their potential as toxin producers. Eutrophication has long been considered the main cause of cyanobacteria outbreak and proliferation, whereas many studies emphasized the effect of abiotic parameters (mainly temperature and light) on cell growth rate or toxin production. In view of the growing concerns of global change consequences on public health parameters, this study attempts to enlighten climate influence on cyanobacteria at regional scale in Brittany (NW France). The results show that homogeneous cyanobacteria groups are associated with climatic domains related to temperature, global radiation and pluviometry, whereas microcystins (MCs) occurrences are only correlated to local cyanobacteria species composition. As the regional climatic gradient amplitude is similar to the projected climate evolution on a 30-year timespan, a comparison between the present NW and SE situations was used to extrapolate the evolution of geographical cyanobacteria distribution in Brittany. Cyanobacteria composition should shift toward species associated with more frequent Microcystins occurrences along a NW/SE axis whereas lakes situated along a SW/NE axis should transition to species (mainly Nostocales) associated with lower MCs detection frequencies. PMID:24476711

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

    PubMed

    Kugeler, Kiersten J; Farley, Grace M; Forrester, Joseph D; Mead, Paul S

    2015-08-01

    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.

  7. Geographic distributions and origins of human head lice (Pediculus humanus capitis) based on mitochondrial data.

    PubMed

    Light, Jessica E; Allen, Julie M; Long, Lauren M; Carter, Tamar E; Barrow, Lisa; Suren, Ganbold; Raoult, Didier; Reed, David L

    2008-12-01

    Human head lice (Pediculus humanus capitis) are subdivided into 3 deeply divergent mitochondrial clades (Clades A, B, and C), each having unique geographical distributions. Determining the evolutionary history and geographic distribution of these mitochondrial clades can elucidate the evolutionary history of the lice as well as their human hosts. Previous data suggest that lice belonging to mitochondrial Clade B may have originated in North America or Asia; however, geographic sampling and sample sizes have been limited. With newly collected lice, we calculate the relative frequency, geographic distribution, and genetic diversity of louse mitochondrial clades to determine the geographic origin of lice belonging to Clade B. In agreement with previous studies, genetic diversity data support a North American origin of Clade B lice. It is likely that lice belonging to this mitochondrial clade recently migrated to other geographic localities, e.g., Europe and Australia, and, if not already present, may disperse further to occupy all geographic regions.

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

    PubMed

    Zhang, Qian; Zhong, Jin-Xin

    2013-05-01

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

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

    PubMed

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

    2015-05-01

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

  10. 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

  11. 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

  12. [[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.

  13. Geographical distribution of the incidence of gastric cancer in Bhutan

    PubMed Central

    Dendup, Tashi; Richter, James M; Yamaoka, Yoshio; Wangchuk, Kinley; Malaty, Hoda M

    2015-01-01

    AIM: To estimate the prevalence of gastric cancer (GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal (GI) cancer during the same period. METHODS: Between 2008 and 2013, five-year period, the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital, Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information, type of cancer, and the year of diagnosis were collected. RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354 (46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus, colon, liver, rectum, pancreas, gall bladder, cholangio-carcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year (367 cases/5 years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year, Eastern region 1.2/10000 per year, and the Western region 1.1/10000 per year. Moreover, GC in the South part was significantly lower than the other GI cancer in the same region (8% vs 15%; OR = 1.8, 95%CI: 1.3-3.1, P = 0.05). Among GC patients, 38% were under the age of 60 years, mean age at diagnosis was 62.3 (± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years (± 13.2) and male-to-female ratio of 1:0.7. At time of diagnosis of GC, 342 (93%) were at stage 3 and 4 of and by the year 2013; 80 (23%) GC patients died compared to 31% death among patients with the all other GI cancer (P = 0.08). CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the

  14. 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

  15. Energy gradients and the geographic distribution of local ant diversity.

    PubMed

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

    2004-08-01

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

  16. 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

  17. Abundance and Distribution of Geographically Isolated Wetlands across the Conterminous United States

    EPA Science Inventory

    Geographically isolated wetlands (GIWS) are important landscape elements involved in hydrologic, biogeochemical, and biological functioning. Their influence, under certain circumstances, can significantly affect other waters of the Unites States. However, there have been no data-...

  18. Genetic diversity and geographical distribution of indigenous soybean-nodulating Bradyrhizobia in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship of indigenous soybean-nodulating bradyrhizobial genetic diversity and geographical distribution in the United States of America (USA) were investigated using soil isolates from eight states (Michigan, Ohio, Kentucky, North Carolina, Alabama, Georgia, Florida and Louisiana) with thre...

  19. Co-circulation of Clade C New World Arenaviruses: New geographic distribution and host species.

    PubMed

    Fernandes, Jorlan; de Oliveira, Renata Carvalho; Guterres, Alexandro; de Carvalho Serra, Fabiana; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sergio; Cunha, Rivaldo Venâncio; Levis, Silvana; de Lemos, Elba Regina Sampaio

    2015-07-01

    Clade C, of the New World Arenaviruses, is composed of only the Latino and Oliveros viruses and, besides the geographic range of their rodent reservoirs, the distribution of these viruses has been restricted to Bolivia and Argentina. In this study, the genetic detection and phylogenetic analysis of the complete S segment sequences of sympatric arenaviruses from Brazil revealed a new geographic distribution of clade C arenaviruses, as well as the association of Oliveros virus with a new rodent reservoir.

  20. Geographic distribution of endemic fungal infections among older persons, United States.

    PubMed

    Baddley, John W; Winthrop, Kevin L; Patkar, Nivedita M; Delzell, Elizabeth; Beukelman, Timothy; Xie, Fenglong; Chen, Lang; Curtis, Jeffrey R

    2011-09-01

    To investigate the epidemiology and geographic distribution of histoplasmosis, coccidioidomycosis, and blastomycosis in older persons in the United States, we evaluated a random 5% sample of national Medicare data from 1999 through 2008. We calculated national, regional, and state-based incidence rates and determined 90-day postdiagnosis mortality rates. We identified 776 cases (357 histoplasmosis, 345 coccidioidomycosis, 74 blastomycosis). Patient mean age was 75.7 years; 55% were male. Histoplasmosis and blastomycosis incidence was highest in the Midwest (6.1 and 1.0 cases/100,000 person-years, respectively); coccidioidomycosis incidence rate was highest in the West (15.2). On the basis of available data, for 86 (11.1%) cases, there was no patient exposure to a traditional disease-endemic area. Knowledge of areas where endemic mycosis incidence is increased may affect diagnostic or prevention measures for older adults at risk.

  1. Sequence variability and geographic distribution of Lassa virus, Sierra Leone.

    PubMed

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

    2015-04-01

    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.

  2. 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

  3. Does mandatory postgraduate clinical training worsen geographic distribution of dentists in Japan?

    PubMed

    Hirata, SoIchiro; Okawa, Yoshikazu; Sugito, Hiroki; Mataki, Shiro; Sakayori, Takaharu; Maki, Yoshinobu; Ishii, Takuo

    2013-01-01

    Postgraduate clinical training for dentists has been mandatory in Japan since 2006. Hirata et al. reported that the geographic distribution of postgraduate dental trainees by prefecture in 2006 was worse than that of practicing dentists. This suggests that the postgraduate clinical training system could intensify the problem of distribution of dentists. In this study, therefore, we reviewed the geographic distribution of postgraduate dental trainees and practicing dentists between 2006 and 2010 in detail by city, ward, town and village by using the Lorenz curve and Gini coefficient. The results showed that while there was no significant worsening of geographic distribution of postgraduate dental trainees, the distribution of practicing dentists continued to deteriorate. A number of reasons may explain these findings: the clinical training system is based on a one-year employment contract, and dentists subsequently relocate as driven by the market; and geographic distribution among cities, towns and villages has worsened as a result of the merger of municipalities. The geographic distribution of practicing dentists is expected to deteriorate further if the number of dentists takes a downward turn in the future. Therefore, it is necessary to continuously review the distribution of postgraduate dental trainees.

  4. The scaling of geographic ranges: implications for species distribution models

    USGS Publications Warehouse

    Yackulic, Charles B.; Ginsberg, Joshua R.

    2016-01-01

    There is a need for timely science to inform policy and management decisions; however, we must also strive to provide predictions that best reflect our understanding of ecological systems. Species distributions evolve through time and reflect responses to environmental conditions that are mediated through individual and population processes. Species distribution models that reflect this understanding, and explicitly model dynamics, are likely to give more accurate predictions.

  5. 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

  6. 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.

  7. Kaposi's Sarcoma in Uganda: Geographic and Ethnic Distribution

    PubMed Central

    Taylor, J. F.; Smith, P. G.; Bull, Diana; Pike, M. C.

    1972-01-01

    Over the quinquennium 1964-68 the crude annual incidence of Kaposi's sarcoma in Uganda per million of the population was 7·9 overall, 14·6 for males and 1·1 for females. Statistical analysis indicates that the disease is most prevalent in highland areas to the west and among the indigenous Bantu tribes. There was no correlation with the distribution of squamous cell carcinoma of the lower leg, and Kaposi's sarcoma was not seen in an Indian or European during the period under review. PMID:4647399

  8. Competition, professional synergism, and the geographic distribution of rural physicians.

    PubMed

    Connor, R A; Hillson, S D; Krawelski, J E

    1995-11-01

    This study provides a theoretical and empirical investigation of competition and synergism among physicians in rural areas. The results show that rural primary care physicians cluster together rather than distribute themselves evenly. This suggests that public policy makers and rural communities must take an active role to ensure provider availability in all rural areas. There is less clustering among subspecialists. The results also reveal a disturbing negative relationship between young children and physician availability in rural areas. Finally, the results provide strong evidence that the relationship between rural physicians and hospitals is synergistic.

  9. Geographic Distribution of Athabasca University Students. Institutional Studies Report No. 3.

    ERIC Educational Resources Information Center

    Smyrnew, John

    Data and analysis of the geographic distribution of students attending Athabasca University in Alberta, Canada, are presented. Attention is directed to student distribution by: Alberta census division, Alberta municipality, urban-rural area, and province and territory. Measurement of student representation is based on the extent to which Athabasca…

  10. 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.

  11. Climate change and the geographic distribution of infectious diseases.

    PubMed

    Rosenthal, Joshua

    2009-12-01

    Our ability to predict the effects of climate change on the spread of infectious diseases is in its infancy. Numerous, and in some cases conflicting, predictions have been developed, principally based on models of biological processes or mapping of current and historical disease statistics. Current debates on whether climate change, relative to socioeconomic determinants, will be a major influence on human disease distributions are useful to help identify research needs but are probably artificially polarized. We have at least identified many of the critical geophysical constraints, transport opportunities, biotic requirements for some disease systems, and some of the socioeconomic factors that govern the process of migration and establishment of parasites and pathogens. Furthermore, we are beginning to develop a mechanistic understanding of many of these variables at specific sites. Better predictive understanding will emerge in the coming years from analyses regarding how these variables interact with each other.

  12. 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

  13. Geographical distribution of Trypanosoma cruzi genotypes in Venezuela.

    PubMed

    Carrasco, Hernán J; Segovia, Maikell; Llewellyn, Martin S; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A; Feliciangeli, M Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI - TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela.

  14. 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.

  15. The geographical distribution of lymphatic filariasis infection in Malawi

    PubMed Central

    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

  16. Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

    PubMed Central

    Carrasco, Hernán J.; Segovia, Maikell; Llewellyn, Martin S.; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E.; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A.; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A.; Feliciangeli, M. Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela. PMID:22745843

  17. 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

  18. 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

  19. 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.

  20. Geographical Distribution of Methanogenic Archaea in Nine Representative Paddy Soils in China

    PubMed Central

    Zu, Qianhui; Zhong, Linghao; Deng, Ye; Shi, Yu; Wang, Baozhan; Jia, Zhongjun; Lin, Xiangui; Feng, Youzhi

    2016-01-01

    Paddy field methanogenic archaea are responsible for methane (CH4) production and contribute significantly to climate change. The information regarding the spatial variations in the abundance, the diversity and the composition of such ecologically important microbes, however, is quite limited at large scale. In this investigation, we studied the abundance, alpha diversity and geographical distribution of methanogenic archaeal communities in nine representative paddy sites, along a large latitudinal gradient in China, using pyrosequencing and real-time quantitative PCR. It is found that all paddy soils harbor constant methanogenic archaeal constituents, which is dominated by family Methanocellaceae (37.3%), Methanobacteriaceae (22.1%), Methanosaetaceae (17.2%), and Methanosarcinaceae (9.8%). Methanogenic archaeal abundance is primarily influenced by soil C (R = 0.612, P = 0.001) and N (R = 0.673, P = 0.001) contents, as well as alpha diversity by soil pH (PD: R = -0.552, P = 0.006; Chao1: R = -0.615, P = 0.002). Further exploration revealed that both spatial distance (R = 0.3469, P = 0.001, partial mental test) and soil chemical variables mainly about soil C and N (R = 0.2847, P = 0.001) are the two major factors affecting methanogenic archaeal community composition distribution in paddy soils. This finding will allow us to develop a better picture of the biogeographic ranges of these ecologically important microbes and get deeper insights into their ecology. PMID:27679621

  1. 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

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

    PubMed Central

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

    2011-01-01

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

  3. Geographic distribution of phylogenetically-distinct legume pod borer, Maruca vitrata (Lepidoptera: Pyraloidea: Crambidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maruca vitrata Fabricius is a pantropical lepidopteran pest of legumes. Phylogenetic analysis of a mitochondrial cytochrome c oxidase-I gene (coxI) fragment indicates that three Maruca sp. mitochondrial lineages have unique geographic distributions [lineages 1 and 2: Australia, Taiwan, and West Afr...

  4. 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

  5. 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

  6. Associations of water balance and thermal sensitivity of toads with macroclimatic characteristics of geographical distribution.

    PubMed

    Titon, Braz; Gomes, Fernando Ribeiro

    2017-03-20

    Interspecific variation in patterns of geographical distribution of phylogenetically related species of amphibians might be related to physiological adaptation to different climatic conditions. In this way, a comparative study of resistance to evaporative water loss, rehydration rates and sensitivity of locomotor performance to variations on hydration level and temperature was performed for five species of Bufonidae toads (Rhinella granulosa, R. jimi, R. ornata, R. schneideri and R. icterica) inhabiting different Brazilian biomes. The hypotheses tested were that, when compared to species inhabiting mesic environments, species living at hot and dry areas would show: (1) greater resistance to evaporative water loss, (2) higher rates of water uptake, (3) lower sensitivity of locomotor performance to dehydration and (4) lower sensitivity of locomotor performance at higher temperatures and higher sensitivity of locomotor performance at lower temperatures. This comparative analysis showed relations between body mass and interspecific variation in rehydration rates and resistance to water loss in opposite directions. These results might represent a functional compensation associated with relatively lower absorption areas in larger toads and higher evaporative areas in smaller ones. Moreover, species from the semi-arid Caatinga showed locomotor performance less sensitive to dehydration but highly affected by lower temperatures, as well greater resistance to evaporative water loss, when compared to the other species from the mesic Atlantic Forest and the savannah-like area called Cerrado. These results suggest adaptations patterns to environmental conditions.

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

    PubMed

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

    2013-12-15

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

  8. 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

  9. New records and geographical distribution of ctenid spiders (Araneae: Ctenidae) in Colombia.

    PubMed

    Hazzi, Nicolás A; Valderrama-Ardila, Carlos; Brescovit, Antonio D; Polotow, Daniele; Simó, Miguel

    2013-01-01

    This study provides new records, geographical distribution extensions and a checklist of the current ctenids species in Colombia based on the review of four arachnological collections and published literature. A total of 15 new records for Ctenidae in Colombia are reported; nine of these species are new records for the country and the distribution of the remaining six is expanded. The genus Centroctenus Mello-Leitão, 1929 (C. ocelliventer Strand, 1909) is recorded for first time in Colombia and Cupiennius coccineus (F.O. Pickard-Cambridge, 1901) for South America. Due to the strategic geographic position of Colombia, which is a transition zone between Southern and Central American biotas, species inventories in different localities are important to fill distributional gaps. The number of known species of ctenids in Colombia is increased from 16 to 25 and these data will be useful for future studies in taxonomy, systematics and biogeography of this family.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. Performance of forest bryophytes with different geographical distributions transplanted across a topographically heterogeneous landscape.

    PubMed

    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.

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

    PubMed

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

    2016-04-20

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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. Expanded host diversity and geographic distribution of hantaviruses in sub-Saharan Africa.

    PubMed

    Kang, Hae Ji; Stanley, William T; Esselstyn, Jacob A; Gu, Se Hun; Yanagihara, Richard

    2014-07-01

    The recent discovery of hantaviruses in shrews and bats in West Africa suggests that other genetically distinct hantaviruses exist in East Africa. Genetic and phylogenetic analyses of newfound hantaviruses, detected in archival tissues from the Geata mouse shrew (Myosorex geata) and Kilimanjaro mouse shrew ( Myosorex zinki) captured in Tanzania, expands the host diversity and geographic distribution of hantaviruses and suggests that ancestral shrews and/or bats may have served as the original mammalian hosts of primordial hantaviruses.

  3. How Sample Size Affects a Sampling Distribution

    ERIC Educational Resources Information Center

    Mulekar, Madhuri S.; Siegel, Murray H.

    2009-01-01

    If students are to understand inferential statistics successfully, they must have a profound understanding of the nature of the sampling distribution. Specifically, they must comprehend the determination of the expected value and standard error of a sampling distribution as well as the meaning of the central limit theorem. Many students in a high…

  4. Hospital distribution in a metropolitan city: assessment by a geographic information system grid modelling approach.

    PubMed

    Lee, Kwang-Soo; Moon, Kyeong-Jun

    2014-05-01

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

  5. 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.

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

    PubMed

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

    2010-03-01

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

  7. 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.

  8. A geographical distribution database of the genus Dysdera in the Canary Islands (Araneae, Dysderidae)

    PubMed Central

    Macías-Hernández, Nuria; López, Salvador de la Cruz; Roca-Cusachs, Marcos; Oromí, Pedro; Arnedo, Miquel A.

    2016-01-01

    Abstract The ground-dweller spider genus Dysdera shows very high species richness on the oceanic archipelago of the Canary Islands, providing one of the most outstanding examples of island radiation among spiders, only paralleled by Tetragnatha spiders on the Hawaiian archipelago. A georeferenced database of the 48 Dysdera species occurring in the Canary Islands was assembled to facilitate ongoing and future research on this remarkable lineage. All species are endemic to the archipelago except for the cosmopolitan Dysdera crocata. The dataset consists of 794 distributional records documented from 1971 to 2015, each locality being represented only once per species. Distribution maps are provided for each species, along with basic diversity and distribution information. The database and geographical maps included in this article stand for the most updated, accurate and complete information on the distribution of the spider genus Dysdera in the Canary Islands. PMID:27833424

  9. A geographical distribution database of the genus Dysdera in the Canary Islands (Araneae, Dysderidae).

    PubMed

    Macías-Hernández, Nuria; López, Salvador de la Cruz; Roca-Cusachs, Marcos; Oromí, Pedro; Arnedo, Miquel A

    2016-01-01

    The ground-dweller spider genus Dysdera shows very high species richness on the oceanic archipelago of the Canary Islands, providing one of the most outstanding examples of island radiation among spiders, only paralleled by Tetragnatha spiders on the Hawaiian archipelago. A georeferenced database of the 48 Dysdera species occurring in the Canary Islands was assembled to facilitate ongoing and future research on this remarkable lineage. All species are endemic to the archipelago except for the cosmopolitan Dysdera crocata. The dataset consists of 794 distributional records documented from 1971 to 2015, each locality being represented only once per species. Distribution maps are provided for each species, along with basic diversity and distribution information. The database and geographical maps included in this article stand for the most updated, accurate and complete information on the distribution of the spider genus Dysdera in the Canary Islands.

  10. Large-scale P2P network based distributed virtual geographic environment (DVGE)

    NASA Astrophysics Data System (ADS)

    Tan, Xicheng; Yu, Liang; Bian, Fuling

    2007-06-01

    Virtual Geographic Environment has raised full concern as a kind of software information system that helps us understand and analyze the real geographic environment, and it has also expanded to application service system in distributed environment--distributed virtual geographic environment system (DVGE), and gets some achievements. However, limited by the factor of the mass data of VGE, the band width of network, as well as numerous requests and economic, etc. DVGE still faces some challenges and problems which directly cause the current DVGE could not provide the public with high-quality service under current network mode. The Rapid development of peer-to-peer network technology has offered new ideas of solutions to the current challenges and problems of DVGE. Peer-to-peer network technology is able to effectively release and search network resources so as to realize efficient share of information. Accordingly, this paper brings forth a research subject on Large-scale peer-to-peer network extension of DVGE as well as a deep study on network framework, routing mechanism, and DVGE data management on P2P network.

  11. Limited geographic distribution of certain strains of the bioluminescent symbiont Photobacterium leiognathi.

    PubMed

    Urbanczyk, Henryk; Kiwaki, Naomi; Furukawa, Takashi; Iwatsuki, Yukio

    2012-08-01

    Photobacterium leiognathi is a facultative bioluminescent symbiont of marine animals. Strains of P. leiognathi that are merodiploid for the luminescence genes (lux-rib operon) have been previously obtained only from Japan. In contrast, strains bearing a single lux-rib operon have been obtained from all the areas sampled in Japan and the western Pacific. In this study, we tested whether distribution of merodiploid P. leiognathi is limited by physical barriers in the environment, or because fish in the western Pacific preferentially form symbiosis with bacteria bearing a single lux-rib operon. We collected light organ symbionts from Secutor indicius, a fish species that is typically found in the western Pacific and has only recently expanded its geographic range to Japan. We found that all S. indicius specimens collected from Japan formed symbiosis only with single lux-rib operon-bearing strains, although fish from other species collected from the same geographic area frequently contained merodiploid strains. This result shows that S. indicius were preferentially colonized by bacteria bearing a single lux-rib operon and suggests that the limited geographic distribution of merodiploid P. leiognathi can be attributed to preferential colonization of fish species found in the western Pacific by strains bearing only a single lux-rib operon.

  12. 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.

  13. 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

  14. Distributed Leadership and Teachers' Affective Commitment

    ERIC Educational Resources Information Center

    Ross, Lisa; Lutfi, Ghazwan A.; Hope, Warren C.

    2016-01-01

    Principals' responsibilities have escalated in quantity and complexity. Mandates to increase student achievement and improve school grades overwhelm one person. Hence, principals are obliged to enlist teachers to serve in leadership roles. This research sought to determine whether there is a relationship between distributed leadership and teacher…

  15. Evolutionary consequences of changes in species' geographical distributions driven by Milankovitch climate oscillations.

    PubMed

    Dynesius, M; Jansson, R

    2000-08-01

    We suggest Milankovitch climate oscillations as a common cause for geographical patterns in species diversity, species' range sizes, polyploidy, and the degree of specialization and dispersability of organisms. Periodical changes in the orbit of the Earth cause climatic changes termed Milankovitch oscillations, leading to large changes in the size and location of species' geographical distributions. We name these recurrent changes "orbitally forced species' range dynamics" (ORD). The magnitude of ORD varies in space and time. ORD decreases gradual speciation (attained by gradual changes over many generations), increases range sizes and the proportions of species formed by polyploidy and other "abrupt" mechanisms, selects against specialization, and favor dispersability. Large ORD produces species prone neither to extinction nor gradual speciation. ORD increases with latitude. This produces latitudinal patterns, among them the gradient in species diversity and species' range sizes (Rapoport's rule). Differential ORD and its evolutionary consequences call for new conservation strategies on the regional to global scale.

  16. Evolutionary consequences of changes in species' geographical distributions driven by Milankovitch climate oscillations

    PubMed Central

    Dynesius, Mats; Jansson, Roland

    2000-01-01

    We suggest Milankovitch climate oscillations as a common cause for geographical patterns in species diversity, species' range sizes, polyploidy, and the degree of specialization and dispersability of organisms. Periodical changes in the orbit of the Earth cause climatic changes termed Milankovitch oscillations, leading to large changes in the size and location of species' geographical distributions. We name these recurrent changes “orbitally forced species' range dynamics” (ORD). The magnitude of ORD varies in space and time. ORD decreases gradual speciation (attained by gradual changes over many generations), increases range sizes and the proportions of species formed by polyploidy and other “abrupt” mechanisms, selects against specialization, and favor dispersability. Large ORD produces species prone neither to extinction nor gradual speciation. ORD increases with latitude. This produces latitudinal patterns, among them the gradient in species diversity and species' range sizes (Rapoport's rule). Differential ORD and its evolutionary consequences call for new conservation strategies on the regional to global scale. PMID:10922067

  17. 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

  18. Mycobacterium tuberculosis lineage 4 comprises globally distributed and geographically restricted sublineages.

    PubMed

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

    2016-12-01

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

  19. 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.

  20. 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

  1. 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

  2. Geographical Distribution Patterns and Niche Modeling of the Iconic Leafcutter Ant Acromyrmex striatus (Hymenoptera: Formicidae).

    PubMed

    Simões-Gomes, Flávia Carolina; Cardoso, Danon Clemes; Cristiano, Maykon Passos

    2017-01-01

    Ants are considered one of the most successful groups in the planet's evolutionary history. Among them highlights the fungus-farming ants of the genera Atta and Acromyrmex that occur throughout most of the Americas. Within the Acromyrmex genus, the species A. striatus distinguishes from other Acromyrmex species as its morphology and karyotype differ from its congeners. This species is found in open environments of dry climate in the southern States of Brazil, Argentina, Paraguay and Uruguay; however, little is known about the current distribution of the species. This article aimed to investigate the current distribution of the species by compiling its known distribution and discussing its distributional range. To achieve this, published and unpublished data obtained through a literature search and active collections in various locations were compiled. Published and unpublished data revealed that 386 colonies were recorded, distributed across four countries where its occurrence is known. Environmental factors, such as temperature, humidity, soil type and vegetation, as well as historical geological and climate events that have modified Earth's surface may have influenced species distribution patterns. In the Neotropics, the environmental factors that most impacted the distribution of species were the glaciation periods that occurred in the Quaternary, leading to a great migratory process. These factors may have contributed to the current geographical distribution of A. striatus.

  3. Some considerations on the use of ecological models to predict species' geographic distributions

    USGS Publications Warehouse

    Peterjohn, B.G.

    2001-01-01

    Peterson (2001) used Genetic Algorithm for Rule-set Prediction (GARP) models to predict distribution patterns from Breeding Bird Survey (BBS) data. Evaluations of these models should consider inherent limitations of BBS data: (1) BBS methods may not sample species and habitats equally; (2) using BBS data for both model development and testing may overlook poor fit of some models; and (3) BBS data may not provide the desired spatial resolution or capture temporal changes in species distributions. The predictive value of GARP models requires additional study, especially comparisons with distribution patterns from independent data sets. When employed at appropriate temporal and geographic scales, GARP models show considerable promise for conservation biology applications but provide limited inferences concerning processes responsible for the observed patterns.

  4. 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

    2016-04-19

    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.

  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. The road most travelled: the geographic distribution of road traffic injuries in England

    PubMed Central

    2013-01-01

    Background Both road safety campaigns and epidemiological research into social differences in road traffic injury risk often assume that road traffic injuries occur close to home. While previous work has examined distance from home to site of collision for child pedestrians in local areas, less is known about the geographic distribution of road traffic injuries from other modes. This study explores the distribution of the distance between home residence and collision site (crash distance) by mode of transport, geographic area, and social characteristics in England. Methods Using 10 years of road casualty data collected by the police, we examined the distribution of crash distance by age, sex, injury severity, area deprivation, urban/rural status, year, day of week, and, in London only, ethnic group. Results 54% of pedestrians, 39% of cyclists, 17% of powered two-wheeler riders and 16% of car occupants were injured within 1 km of home. 82% of pedestrians, 83% of cyclists, 54% of powered two-wheeler and 53% of car occupants were injured within 5 km of home. We found some social and geographic differences in crash distance: for all transport modes injuries tended to occur closer to home in more deprived or urban areas; younger and older pedestrians and cyclists were also injured closer to home. Crash distance appears to have increased over time for pedestrian, cyclist and car occupant injuries, but has decreased over time for powered two-wheeler injuries. Conclusions Injuries from all travel modes tend to occur quite close to home, supporting assumptions made in epidemiological and road safety education literature. However, the trend for increasing crash distance and the social differences identified may have methodological implications for future epidemiological studies on social differences in injury risk. PMID:23738624

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

    PubMed Central

    2012-01-01

    Background Pesticide self-poisoning is the most commonly used suicide method worldwide, but few studies have investigated the national epidemiology of pesticide suicide in countries where it is a major public health problem. This study aims to investigate geographic variations in pesticide suicide and their impact on the spatial distribution of suicide in Taiwan. Methods Smoothed standardized mortality ratios for pesticide suicide (2002-2009) were mapped across Taiwan's 358 districts (median population aged 15 or above = 27 000), and their associations with the size of agricultural workforce were investigated using Bayesian hierarchical models. Results In 2002-2009 pesticide poisoning was the third most common suicide method in Taiwan, accounting for 13.6% (4913/36 110) of all suicides. Rates were higher in agricultural East and Central Taiwan and lower in major cities. Almost half (47%) of all pesticide suicides occurred in areas where only 13% of Taiwan's population lived. The geographic distribution of overall suicides was more similar to that of pesticide suicides than non-pesticide suicides. Rural-urban differences in suicide were mostly due to pesticide suicide. Areas where a higher proportion of people worked in agriculture showed higher pesticide suicide rates (adjusted rate ratio [ARR] per standard deviation increase in the proportion of agricultural workers = 1.58, 95% Credible Interval [CrI] 1.44-1.74) and overall suicide rates (ARR = 1.06, 95% CrI 1.03-1.10) but lower non-pesticide suicide rates (ARR = 0.91, 95% CrI 0.87-0.95). Conclusion Easy access to pesticides appears to influence the geographic distribution of suicide in Taiwan, highlighting the potential benefits of targeted prevention strategies such as restricting access to highly toxic pesticides. PMID:22471759

  9. 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.

  10. 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

  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.

  12. 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.

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

    PubMed

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

    2014-12-01

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

  14. Potential geographical distributions of the fruit flies Ceratitis capitata, Ceratitis cosyra, and Ceratitis rosa in China.

    PubMed

    Li, Baini; Ma, Jun; Hu, Xuenan; Liu, Haijun; Zhang, Runjie

    2009-10-01

    There have been relatively few attempts to model the distributions of the fruit flies Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), and Ceratitis rosa Karsch in China, but the geographic distributions of these species are of considerable concern in terms of biosecurity. In this study, two different modeling methods (genetic algorithm for rule-set prediction [GARP] and maximum entropy species distribution modeling [Maxent]) were used to predict the potential distributions of these three fly species in China, by using distribution records and a set of environmental predictor variables. The results showed that Maxent performed well, compared with modeling by GARP, at each test threshold. For all three species, the results predicted by Maxent agreed with the observed distributions in Africa and in other parts of the world. In China, C. capitata seems to have the highest number of favorable habitat areas, relative to C. cosyra and C. rosa, i.e., Yunnan, Guizhou, Guangxi, Guangdong, Hainan, Fujian, Sichuan and Chongqing, whereas C. cosyra has the smallest range of suitable areas, i.e., Yunnan, some parts of Hainan and Sichuan. The suitable areas for C. rosa are mainly restricted to Yunnan, Hainan, southern Guangdong, and a few areas of Sichuan. The indications are that on the whole, Southwest and South China are the areas with the highest risk for establishment from these three fly species. Jackknife tests reveal that environmental variables associated with temperature have the strongest influence on the potential distributions of all three species relative to other variables.

  15. Geographic distribution and serologic and genomic characterization of Morro Bay virus, a newly recognized bunyavirus.

    PubMed

    Fulhorst, C F; Bowen, M D; Hardy, J L; Eldridge, B F; Chiles, R E; Jackson, A O; Reeves, W C

    1996-06-01

    More than 75,000 immature mosquitoes in three genera were collected from coastal California, reared to the adult stage, and tested for virus by plaque assay in Vero cell cultures. Twenty-six strains of Morro Bay (MB) virus, a newly recognized member of the California (CAL) serogroup, were isolated from Aedes squamiger, a pestiferous salt marsh mosquito species restricted to intertidal salt marshes in coastal California and Baja California. The geographic distribution of the isolates was 10 from San Luis Obispo County, one each from Santa Barbara and Orange Counties, and 14 from San Diego County. No virus isolations were made from 23,157 Ae. squamiger collected north of San Luis Obispo County (midpoint in the geographic range of this species in California). Thus, MB virus infection in Ae. squamiger appears to be restricted to the southern range of this species in California. Serum dilution neutralization tests indicated that MB virus represents a novel subtype of the California encephalitis (CE) serotype within the CAL serogroup. Comparative analyses of genomic sequence data from four geographically distinct MB virus isolates indicated that the isolates are genetically similar to each other and distinct from other CE serotype bunyaviruses. Phylogenetic analysis of nucleocapsid protein gene sequence data indicated that MB virus represents a distinct lineage within the CE serotype and thus supports the serologic classification of MB virus as a distinct CAL serogroup virus.

  16. 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.

  17. Healthcare "just around the corner": the role of geographic distribution strategies and healthcare costs.

    PubMed

    Keegan, Deborah Walker

    2010-01-01

    Proponents of the healthcare reform agenda continually compare per capita healthcare spending in the United States to other nations and cite this as one of the clear mandates for healthcare reform. The purpose of this article is to draw attention to the cost of geographic distribution strategies adopted by healthcare organizations and the impact this has on per capita healthcare costs. It is important to quantify the cost of such strategies and to weigh their merits, if the intent is to substantially reduce the cost of healthcare in the United States.

  18. The role of poverty rate and racial distribution in the geographic clustering of breast cancer survival among older women: a geographic and multilevel analysis.

    PubMed

    Schootman, Mario; Jeffe, Donna B; Lian, Min; Gillanders, William E; Aft, Rebecca

    2009-03-01

    The authors examined disparities in survival among women aged 66 years or older in association with census-tract-level poverty rate, racial distribution, and individual-level factors, including patient-, treatment-, and tumor-related factors, utilization of medical care, and mammography use. They used linked data from the 1992-1999 Surveillance, Epidemiology, and End Results (SEER) programs, 1991-1999 Medicare claims, and the 1990 US Census. A geographic information system and advanced statistics identified areas of increased or reduced breast cancer survival and possible reasons for geographic variation in survival in 2 of the 5 SEER areas studied. In the Detroit, Michigan, area, one geographic cluster of shorter-than-expected breast cancer survival was identified (hazard ratio (HR) = 1.60). An additional area where survival was longer than expected approached statistical significance (HR = 0.4; P = 0.056). In the Atlanta, Georgia, area, one cluster of shorter- (HR = 1.81) and one cluster of longer-than-expected (HR = 0.72) breast cancer survival were identified. Stage at diagnosis and census-tract poverty (and patient's race in Atlanta) explained the geographic variation in breast cancer survival. No geographic clusters were identified in the 3 other SEER programs. Interventions to reduce late-stage breast cancer, focusing on areas of high poverty and targeting African Americans, may reduce disparities in breast cancer survival in the Detroit and Atlanta areas.

  19. Cost-effective age structure and geographical distribution of boreal forest reserves.

    PubMed

    Lundström, Johanna; Ohman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald

    2011-02-01

    1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied.2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area.3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0-14 years than in forests 15-69 years.4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area.5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class.6.Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and cost

  20. Cost-effective age structure and geographical distribution of boreal forest reserves

    PubMed Central

    Lundström, Johanna; Öhman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald

    2011-01-01

    1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied. 2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area. 3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0–14 years than in forests 15–69 years. 4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area. 5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class. 6. Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and

  1. 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

  2. Temperature Effects on Gametophyte Life-History Traits and Geographic Distribution of Two Cryptic Kelp Species

    PubMed Central

    Oppliger, L. Valeria; Correa, Juan A.; Engelen, Aschwin H.; Tellier, Florence; Vieira, Vasco; Faugeron, Sylvain; Valero, Myriam; Gomez, Gonzalo; Destombe, Christophe

    2012-01-01

    A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte) of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29–30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1) estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2) compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ) at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed. PMID:22723987

  3. The impact of climate on the geographical distribution of phytoplankton species in boreal lakes.

    PubMed

    Hallstan, Simon; Trigal, Cristina; Johansson, Karin S L; Johnson, Richard K

    2013-12-01

    Here, we use a novel space-by-time approach to study large-scale changes in phytoplankton species distribution in Swedish boreal lakes in response to climate variability. Using phytoplankton samples from 27 lakes, evenly distributed across Sweden, all relatively unimpacted by anthropogenic disturbance and sampled annually between 1996 and 2010, we found significant shifts in the geographical distribution of 18 species. We also found significant changes in the prevalence of 45 species (33 became more common and 12 less common) over the study period. Using species distribution models and phytoplankton samples from 60 lakes sampled at least twice between 1992 and 2010, we evaluated the importance of climate variability and other environmental variables on species distribution. We found that temperature (e.g., extreme events and the duration of the growing season) was the most important predictor for species detections. Many cyanobacteria, chlorophytes, and, to a lesser extent, diatoms and zygnematophytes, showed congruent and positive responses to temperature. In contrast, precipitation explained little variation and was important only for a few taxa (e.g., Staurodesmus spp., Trachelomonas volvocina). At the community level, our results suggest a change in community composition at temperatures over 20 °C and growing seasons longer than 40 days. We conclude that climate is an important driver of the distributional patterns of individual phytoplankton species and may drive changes in community composition in minimally disturbed boreal lakes.

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

    PubMed

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

    2015-06-01

    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.

  5. Geographic Distribution of Hantaviruses Associated with Neotomine and Sigmodontine Rodents, Mexico

    PubMed Central

    Milazzo, Mary L.; Cajimat, Maria N.B.; Romo, Hannah E.; Estrada-Franco, Jose G.; Iñiguez-Dávalos, L. Ignacio; Bradley, Robert D.

    2012-01-01

    To increase our knowledge of the geographic distribution of hantaviruses associated with neotomine or sigmodontine rodents in Mexico, we tested 876 cricetid rodents captured in 18 Mexican states (representing at least 44 species in the subfamily Neotominae and 10 species in the subfamily Sigmodontinae) for anti-hantavirus IgG. We found antibodies against hantavirus in 35 (4.0%) rodents. Nucleotide sequence data from 5 antibody-positive rodents indicated that Sin Nombre virus (the major cause of hantavirus pulmonary syndrome [HPS] in the United States) is enzootic in the Mexican states of Nuevo León, San Luis Potosí, Tamaulipas, and Veracruz. However, HPS has not been reported from these states, which suggests that in northeastern Mexico, HPS has been confused with other rapidly progressive, life-threatening respiratory diseases. Analyses of nucleotide sequence data from 19 other antibody-positive rodents indicated that El Moro Canyon virus and Limestone Canyon virus are geographically widely distributed in Mexico. PMID:22469569

  6. Gene Flow and the Geographical Distribution of a Molecular Polymorphism in DROSOPHILA PSEUDOOBSCURA

    PubMed Central

    Jones, J. S.; Bryant, S. H.; Lewontin, R. C.; Moore, J. A.; Prout, T.

    1981-01-01

    This paper discusses the relation between the geographical distribution of an enzyme polymorphism and population structure in Drosophila pseudoobscura. California populations of this species living in very different montane and lowland habitats separated by several kilometers are similar to each other in the frequency of an esterase allele. Previous estimates suggest that gene flow is too limited to account for this homogeneity of genetic structure, so that it must reflect some balancing force of natural selection. We show, however, that dispersal over unfavorable habitats is much greater than earlier supposed. Isolated populations of D. pseudoobscura separated by 15 km from other populations are subject to large amounts of immigration. This is shown by changes in the seasonal abundance of this species and in the annual pattern of lethal alleles in such populations. The genetic structure of an experimentally perturbed isolated population in an oasis returned to normal within a single year, suggesting that such populations are ephemeral and that the oasis is subject to annual recolonization by distant migrants. Direct assessment of marked flies shows that they can move at least 10 km in 24 hours over a desert. Such extensive gene flow may help explain the distribution of the esterase allele, and is relevant to the high level of molecular polymorphism and its general lack of geographic differentiation throughout the range of D. pseudoobscura. PMID:7338302

  7. Research on the efficiency of distributed virtual geographic environment in P2P network

    NASA Astrophysics Data System (ADS)

    Duan, Lian; Hu, Baoqing

    2008-12-01

    Now most of distributed virtual geographic environments (DVGE) applications still adopt the centralized pattern, which brings the network congestion or single point of failure to the side of center server. But the P2P technique takes away the bottleneck in data transmission exists in traditional C/S model by virtue of its multilink self-adaptive mechanism of the data transmission, which has a magnitude meaning for researches on the spatial data delivering in distributed virtual geographic environment. As the spatial data has the characteristic of the massive volumes and client change the interesting spatial area in virtual scene so frequently that the spatial application efficiency is sharply decreased, the author brought forward a layered P2P architecture of the spatial data interoperation and flexible group mode in P2P network. A mechanism of layered query of oriented suit (LQOS) and the self-adapted cache mode were introduced to adjust the peer loading and the link numbers for the reliable data capture. In this way, we provide DVGE the rapid data transmission speed among peers, the great data transmission reliability and the better user experience. A DVGE prototype was developed and it proved the efficiency of this P2P DVGE framework. At last the futures of involved techniques and methods are concluded.

  8. Ribotyping of Erwinia chrysanthemi Strains in Relation to Their Pathogenic and Geographic Distribution

    PubMed Central

    Nassar, Atef; Bertheau, Yves; Dervin, Catherine; Narcy, Jean-Paul; Lemattre, Monique

    1994-01-01

    16S and 23S rRNAs from Escherichia coli were used to study the relationship among a representative collection of strains of Erwinia chrysanthemi differing in their original host and geographical origin. Phenetic analysis of restriction fragment length polymorphisms allowed the distribution of the studied strains into seven clusters. These clusters were similar to those obtained by cladistic methods and appeared to correlate well with the established pathovars and biovars but to a lesser extent with geographical distribution. Except for two groups of strains defined as tropical and temperate isolates (clusters 3 and 4, respectively), our clustering correlated well with botanical classifications of host plants. However, the rRNA groupings were shown to be more discriminative than biovar analysis. To assess the relationship between rRNA clusters and pathogenicity, 12 representative strains from different clusters were tested for pathogenicity on different plants. The two typical symptoms, maceration and wilting, were observed for these strains. The occurrence of the tobacco hypersensitivity reaction for a subset of these strains is discussed in light of recent results concerning the presence of an hrp gene. Considering symptom expression only, rather than the capacity for plant infection, strains from the same cluster were shown to induce similar symptoms in test plants. Thus, since host specificity is still quite controversial, rRNA patterns may constitute a useful tool in taxonomic and epidemiological studies of Erwinia chrysanthemi species. Images PMID:16349416

  9. Geographic distribution of hantaviruses associated with neotomine and sigmodontine rodents, Mexico.

    PubMed

    Milazzo, Mary L; Cajimat, Maria N B; Romo, Hannah E; Estrada-Franco, Jose G; Iñiguez-Dávalos, L Ignacio; Bradley, Robert D; Fulhorst, Charles F

    2012-04-01

    To increase our knowledge of the geographic distribution of hantaviruses associated with neotomine or sigmodontine rodents in Mexico, we tested 876 cricetid rodents captured in 18 Mexican states (representing at least 44 species in the subfamily Neotominae and 10 species in the subfamily Sigmodontinae) for anti-hantavirus IgG. We found antibodies against hantavirus in 35 (4.0%) rodents. Nucleotide sequence data from 5 antibody-positive rodents indicated that Sin Nombre virus (the major cause of hantavirus pulmonary syndrome [HPS] in the United States) is enzootic in the Mexican states of Nuevo León, San Luis Potosí, Tamaulipas, and Veracruz. However, HPS has not been reported from these states, which suggests that in northeastern Mexico, HPS has been confused with other rapidly progressive, life-threatening respiratory diseases. Analyses of nucleotide sequence data from 19 other antibody-positive rodents indicated that El Moro Canyon virus and Limestone Canyon virus are geographically widely distributed in Mexico.

  10. 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

  11. 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

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

    PubMed

    Vásquez-Ordóñez, Aymer Andrés; Parsa, Soroush

    2014-01-01

    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).

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

    PubMed

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

    2016-05-31

    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.

  14. 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.

  15. 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

  16. Prevalence and geographic distribution of canine and feline blastomycosis in the Canadian prairies.

    PubMed

    Davies, Jennifer L; Epp, Tasha; Burgess, Hilary J

    2013-08-01

    This retrospective study reports patient signalment, method of diagnosis and geographic distribution, and examines trends in prevalence and seasonal distribution of blastomycosis cases submitted to a veterinary diagnostic laboratory in Saskatchewan over a 21-year period. Of the 143 cases that originated from Saskatchewan and Manitoba 137 were from canine and 6 from feline patients. Signalment was similar to that previously reported. All cases originated in southern Saskatchewan and Manitoba, primarily from Regina, Moose Jaw, Swift Current, and Winnipeg. Case numbers showed a significant increase in the period 2001 to 2010 compared to 1990 to 2000. Seasonally, there was an increasing trend in the number of diagnoses from February to November. There was no correlation between average seasonal temperature or average seasonal total precipitation and the number of cases of blastomycosis. The persistence of blastomycosis in southern Saskatchewan indicates that Blastomyces dermatitidis is now endemic in this region.

  17. Contrasting Influences of Geographic Range and Distribution of Populations on Patterns of Genetic Diversity in Two Sympatric Pilbara Acacias

    PubMed Central

    Levy, E.; Byrne, M.; Coates, D. J.; Macdonald, B. M.; McArthur, S.; van Leeuwen, S.

    2016-01-01

    The influence of geographic range on species persistence has long been of interest and there is a need for a better understanding of the genetic consequences for species with restricted distributions, particularly with the increasing rate of global species extinctions. However, the genetic effects of restricted range are often confounded by the impacts of population distribution. We compared chloroplast and nuclear genetic diversity and differentiation in two acacias, the restricted, patchily distributed Acacia atkinsiana and the widespread, semi-continuously distributed A. ancistrocarpa. Lower intra-population diversity and higher differentiation between populations were seen in A. atkinsiana compared to its widespread congener, A. ancistrocarpa. There was little evidence of geographical influences on population genetic structure in A. ancistrocarpa whereas A. atkinsiana exhibited nuclear genetic structure with isolation by distance, differentiation of near-coastal populations from those in the ranges, and differentiation of peripheral populations from those in the centre of the distribution. These results are consistent with expectations of the effect of geographic range and population distribution on genetic diversity, but indicate that distribution of populations rather than geographic range has influenced the observed genetic structure. The contrasting patterns observed here demonstrate that conservation approaches for species management and ecological restoration need to consider the distribution of populations in geographically restricted species. PMID:27768703

  18. 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

  19. Geographic Distribution and Niche Divergence of Two Stinkbugs, Parastrachia japonensis and Parastrachia nagaensis

    PubMed Central

    Zhu, Gengping; Liu, Guoqing; Bu, Wenjun; Lis, Jerzy A.

    2013-01-01

    Parastrachiidae is a small stinkbug family containing only one genus and two species, Parastrachia japonensis (Scott) (Hemiptera: Heteroptera: Pentatomoidea) and Parastrachia nagaensis Distant. The geographic distribution of the genus has been poorly studied. Niche conservatism refers to that idea that closely related species are more ecologically similar than would be expected, whereas niche divergence predicts they occupy distinct niche spaces. The existence of only two species within one genus suggests niche conservatism or differentiation might exist among them. Herein, the distribution of the genus was mapped, potential distributions were predicted using ecological niche modeling, and climate spaces occupied by the two species were identified and compared. Our outlined map supports the general spreading route proposed by Schaefer et al. The potential distributions suggest that the genus’ range could extend beyond its presently known distribution, and further investigation into this area could aid in their conservation, particularly P. nagaensis. The niche space inferred by ecological niche modeling suggests the two species do not occupy identical habitat, but the differences between their models could simply be due to the differential availability of habitat in the different regions that they occupy. PMID:24738857

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

    PubMed

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

    2013-07-01

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

  1. A model for the influence of the greenhouse effect on insect and microorganism geographical distribution and population dynamics.

    PubMed

    Karafyllidis, I

    1998-01-01

    A model for the influence of the greenhouse effect on insect and microorganism geographical distribution and population dynamics using cellular automata is presented. Based on this model, an algorithm has been developed and used to determine the geographical distribution and population dynamics of a hypothetical species in an scenario of global warming. The species' initial population distribution is assumed to be Gaussian. After the initiation of global warming, the population moves and after a few decades the population distribution is no longer Gaussian. Larger populations are found in the direction of population movement.

  2. 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.

  3. 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

  4. The geographic distribution of trace elements in the environment: the REGARDS study.

    PubMed

    Rembert, Nicole; He, Ka; Judd, Suzanne E; McClure, Leslie A

    2017-02-01

    Research on trace elements and the effects of their ingestion on human health is often seen in scientific literature. However, little research has been done on the distribution of trace elements in the environment and their impact on health. This paper examines what characteristics among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study are associated with levels of environmental exposure to arsenic, magnesium, mercury, and selenium. Demographic information from REGARDS participants was combined with trace element concentration data from the US Geochemical Survey (USGS). Each trace element was characterized as either low (magnesium and selenium) or high (arsenic and mercury) exposure. Associations between demographic characteristics and trace element concentrations were analyzed with unadjusted and adjusted logistic regression models. Individuals who reside in the Stroke Belt have lower odds of high exposure (4th quartile) to arsenic (OR 0.33, CI 0.31, 0.35) and increased exposure to mercury (OR 0.65, CI 0.62, 0.70) than those living outside of these areas, while the odds of low exposure to trace element concentrations were increased for magnesium (OR 5.48, CI 5.05, 5.95) and selenium (OR 2.37, CI 2.22, 2.54). We found an association between levels of trace elements in the environment and geographic region of residence, among other factors. Future studies are needed to further examine this association and determine whether or not these differences may be related to geographic variation in disease.

  5. 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

  6. 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.

  7. Potential Geographic Distribution of Brown Marmorated Stink Bug Invasion (Halyomorpha halys)

    PubMed Central

    Zhu, Gengping; Bu, Wenjun; Gao, Yubao; Liu, Guoqing

    2012-01-01

    Background The Brown Marmorated Stink Bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), native to Asia, is becoming an invasive species with a rapidly expanding range in North America and Europe. In the US, it is a household pest and also caused unprecedented damage to agriculture crops. Exploring its climatic limits and estimating its potential geographic distribution can provide critical information for management strategies. Methodology/Principals We used direct climate comparisons to explore the climatic niche occupied by native and invasive populations of BMSB. Ecological niche modelings based on the native range were used to anticipate the potential distribution of BMSB worldwide. Conversely, niche models based on the introduced range were used to locate the original invasive propagates in Asia. Areas with high invasion potential were identified by two niche modeling algorithms (i.e., Maxent and GARP). Conclusions/Significance Reduced dimensionality of environmental space improves native model transferability in the invade area. Projecting models from invasive population back to native distributional areas offers valuable information on the potential source regions of the invasive populations. Our models anticipated successfully the current disjunct distribution of BMSB in the US. The original propagates are hypothesized to have come from northern Japan or western Korea. High climate suitable areas at risk of invasion include latitudes between 30°–50° including northern Europe, northeastern North America, southern Australia and the North Island of New Zealand. Angola in Africa and Uruguay in South America also showed high climate suitability. PMID:22363595

  8. 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

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

    PubMed

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

    2014-09-19

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

  10. Interactions between Soil Habitat and Geographic Range Location Affect Plant Fitness

    PubMed Central

    Stanton-Geddes, John; Shaw, Ruth G.; Tiffin, Peter

    2012-01-01

    Populations are often found on different habitats at different geographic locations. This habitat shift may be due to biased dispersal, physiological tolerances or biotic interactions. To explore how fitness of the native plant Chamaecrista fasciculata depends on habitat within, at and beyond its range edge, we planted seeds from five populations in two soil substrates at these geographic locations. We found that with reduced competition, lifetime fitness was always greater or equivalent in one habitat type, loam soils, though early-season survival was greater on sand soils. At the range edge, natural populations are typically found on sand soil habitats, which are also less competitive environments. Early-season survival and fitness differed among source populations, and when transplanted beyond the range edge, range edge populations had greater fitness than interior populations. Our results indicate that even when the optimal soil substrate for a species does not change with geographic range location, the realized niche of a species may be restricted to sub-optimal habitats at the range edge because of the combined effects of differences in abiotic and biotic effects (e.g. competitors) between substrates. PMID:22615745

  11. Interactions between soil habitat and geographic range location affect plant fitness.

    PubMed

    Stanton-Geddes, John; Shaw, Ruth G; Tiffin, Peter

    2012-01-01

    Populations are often found on different habitats at different geographic locations. This habitat shift may be due to biased dispersal, physiological tolerances or biotic interactions. To explore how fitness of the native plant Chamaecrista fasciculata depends on habitat within, at and beyond its range edge, we planted seeds from five populations in two soil substrates at these geographic locations. We found that with reduced competition, lifetime fitness was always greater or equivalent in one habitat type, loam soils, though early-season survival was greater on sand soils. At the range edge, natural populations are typically found on sand soil habitats, which are also less competitive environments. Early-season survival and fitness differed among source populations, and when transplanted beyond the range edge, range edge populations had greater fitness than interior populations. Our results indicate that even when the optimal soil substrate for a species does not change with geographic range location, the realized niche of a species may be restricted to sub-optimal habitats at the range edge because of the combined effects of differences in abiotic and biotic effects (e.g. competitors) between substrates.

  12. Genetic structure of wild bonobo populations: diversity of mitochondrial DNA and geographical distribution.

    PubMed

    Kawamoto, Yoshi; Takemoto, Hiroyuki; Higuchi, Shoko; Sakamaki, Tetsuya; Hart, John A; Hart, Terese B; Tokuyama, Nahoko; Reinartz, Gay E; Guislain, Patrick; Dupain, Jef; Cobden, Amy K; Mulavwa, Mbangi N; Yangozene, Kumugo; Darroze, Serge; Devos, Céline; Furuichi, Takeshi

    2013-01-01

    Bonobos (Pan paniscus) inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species' range. In 136 effective samples from different individuals (range: 7-37 per population), we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D), which included a newly identified clade (D). MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.

  13. 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

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

    PubMed

    Renner, Susanne S; Pandey, Arun K

    2013-01-01

    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.

  15. 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.

  16. Geographically distributed complementary content-based image retrieval systems for biomedical image informatics.

    PubMed

    Antani, Sameer K; Deserno, Thomas M; Long, L Rodney; Thoma, George R

    2007-01-01

    There is a significant increase in the use of medical images in clinical medicine, disease research, and education. While the literature lists several successful systems for content-based image retrieval and image management methods, they have been unable to make significant inroads in routine medical informatics. This can be attributed to the following: (i) the challenging nature of medical images, (ii) need for specialized methods specific to each image type and detail, (iii) lack of advances in image indexing methods, and (iv) lack of a uniform data and resource exchange framework between complementary systems. Most systems tend to focus on varying degrees of the first two items, making them very versatile in a small sampling of the variety of medical images but unable to share their strengths. This paper proposes to overcome these shortcomings by defining a data and resource exchange framework using open standards and software to develop geographically distributed toolkits. As proof-of-concept, we describe the coupling of two complementary geographically separated systems: the IRMA system at Aachen University of Technology in Germany, and the SPIRS system at the U. S. National Library of Medicine in the United States of America.

  17. 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

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

    PubMed

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

    2014-04-01

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

  19. Geographical distribution and accumulation features of PBDEs in human breast milk from Indonesia.

    PubMed

    Sudaryanto, Agus; Kajiwara, Natsuko; Takahashi, Shin; Muawanah; Tanabe, Shinsuke

    2008-01-01

    The present study reports concentrations of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in human breast milk from Indonesia covering urban, suburban and rural areas. PBDEs were detected in all the samples of the present study with total concentrations ranging from 0.49 to 13 ng/g lipid wt. Geographical distribution showed that concentrations of PBDEs were relatively uniform (p>0.05) and the levels were in the same order as those in Japan and some European countries, but were one or two order lower than North America. When compared to OCs, the level of total PBDEs was lower. The congener pattern was in accordance with other studies on human matrices, in which BDE-47 was the most abundant congener. Variations of PBDE congeners in human breast milk were further discussed to elucidate the potential exposure source(s) and pathways.

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

    PubMed

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

    1986-01-01

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

  1. Scorpion sting epidemiology in Montes Municipality of the State of Sucre, Venezuela: geographic distribution.

    PubMed

    De Sousa, L; Bonoli, S; Quiroga, M; Parrilla, P

    1996-01-01

    Scorpion stings were surveyed in the Montes Municipality of the State of Sucre, Venezuela, aiming to extend the information on these poisonous accidents by characterizing their geographic distribution. From 1980 to 1990, 184 cases of scorpion stings were recorded with an incidence rate of 38.6 cases per 10,000 inhabitants. The locality of San Fernando presented the highest incidence (68.3/1000) of poisonous accidents. The highest percentages of severe cases were recorded in the towns of Arenas (27%), San Lorenzo (21%), and Cocollar (19%), which are located at the foot of the Turimiquire Mountains. This region is a dispersion area of scorpions of the Tityus genus. Our results show that this region of the State of Sucre is endemic for scorpion stings which are an important public health problem.

  2. The development of the heterogenic geographical distributed system for the celestial object monitoring

    NASA Astrophysics Data System (ADS)

    Vitkovskij, V. V.; Zhelenkova, O.; Kalinina, N.; Chernenkov, V.; Shergin, V.

    2006-07-01

    There is no principal difference between data stored in an archive and data received from a telescope or data computed from a numerical experiment. There is no big difference between the real science experimenters and science students. There are small differences, in the collaboration sense, between the live association of investigators and the virtual one. Therefore the VO would be including not only data collections and software, but the experimental complexes, the education/training features and the virtual community. The creation of geographical distributed system that unites small and medium size telescopes for Russia is an unique possibility to improve the astronomical research at the high worldwide level. The variable and transient objects monitoring is requesting the long range longitude/latitude observations network.

  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. Influence of seasonal migration on geographic distribution of mitochondrial DNA haplotypes in humpback whales.

    PubMed

    Baker, C S; Palumbi, S R; Lambertsen, R H; Weinrich, M T; Calambokidis, J; O'Brien, S J

    1990-03-15

    Humpback whales (Megaptera novaeangliae) migrate nearly 10,000 km each year between summer feeding grounds in temperate or near-polar waters and winter breeding grounds in shallow tropical waters. Observations of marked individuals suggest that major oceanic populations of humpback whales are divided into a number of distinct seasonal subpopulations which are not separated by obvious geographic barriers. To test whether these observed patterns of distribution and migration are reflected in the genetic structure of populations, we looked for variation in the mitochondrial DNA of 84 individual humpback whales on different feeding and wintering grounds of the North Pacific and western North Atlantic oceans. On the basis of restriction-fragment analysis, we now report a marked segregation of mitochondrial DNA haplotypes among subpopulations as well as between the two oceans. We interpret this segregation to be the consequence of maternally directed fidelity to migratory destinations.

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

    PubMed

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

    2016-05-01

    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.

  6. Enhancing the transfer of computer-assisted training proficiency in geographically distributed teams.

    PubMed

    Kirkman, Bradley L; Rosen, Benson; Tesluk, Paul E; Gibson, Cristina B

    2006-05-01

    The authors examined factors that determine whether knowledge gained from computer-assisted (i.e., technology-based) team training in a geographically distributed team (GDT) context transfers to organizational results. They examined the moderating effects of team trust, technology support, and leader experience on the relation between teams' average individual training proficiency on a computer-assisted (i.e., CD-ROM-based) training program and team performance as assessed by team customer satisfaction ratings. Using data collected from 40 GDTs in a high-technology company, the authors found that the relation between teams' average training proficiency and team performance was complex and moderated by several factors. In particular, teams' average training proficiency had a positive association with customer satisfaction when GDTs were higher, rather than lower, in both trust and technology support and when team leaders had longer, rather than shorter, levels of tenure with their specific team.

  7. Distribution of Brazilian dermatologists according to geographic location, population and HDI of municipalities: an ecological study*

    PubMed Central

    Schmitt, Juliano Vilaverde; Miot, Hélio Amante

    2014-01-01

    This study investigated the geographic distribution of dermatologists in Brazilian municipalities in relation to the population, regions of the country and human development index. We conducted an ecological study based on data from the 2010 census, the 2010 human development index, and the records of the Brazilian Society of Dermatology. 5565 municipalities and 6718 dermatologists were surveyed. Only 504 (9.1%) municipalities had dermatologists, and accounted for 56.2% of the Brazilian population. The smallest population size and lowest HDI rate that best discriminated municipalities that did not have dermatologists were found to be 28,000 and 0.71, respectively. The average population density of dermatologists in cities was 1/23.000 inhabitants, and variations were independently associated with the HDI, the population of the municipalities and the region of the country. PMID:25387516

  8. Burkholderia, a Genus Rich in Plant-Associated Nitrogen Fixers with Wide Environmental and Geographic Distribution

    PubMed Central

    Estrada-De Los Santos, Paulina; Bustillos-Cristales, Rocío; Caballero-Mellado, Jesús

    2001-01-01

    The genus Burkholderia comprises 19 species, including Burkholderia vietnamiensis which is the only known N2-fixing species of this bacterial genus. The first isolates of B. vietnamiensis were recovered from the rhizosphere of rice plants grown in a phytotron, but its existence in natural environments and its geographic distribution were not reported. In the present study, most N2-fixing isolates recovered from the environment of field-grown maize and coffee plants cultivated in widely separated regions of Mexico were phenotypically identified as B. cepacia using the API 20NE system. Nevertheless, a number of these isolates recovered from inside of maize roots, as well as from the rhizosphere and rhizoplane of maize and coffee plants, showed similar or identical features to those of B. vietnamiensis TVV75T. These features include nitrogenase activity with 10 different carbon sources, identical or very similar nifHDK hybridization patterns, very similar protein electrophoregrams, identical amplified 16S rDNA restriction (ARDRA) profiles, and levels of DNA-DNA reassociation higher than 70% with total DNA from strain TVV75T. Although the ability to fix N2 is not reported to be a common feature among the known species of the genus Burkholderia, the results obtained show that many diazotrophic Burkholderia isolates analyzed showed phenotypic and genotypic features different from those of the known N2-fixing species B. vietnamiensis as well as from those of B. kururiensis, a bacterium identified in the present study as a diazotrophic species. DNA-DNA reassociation assays confirmed the existence of N2-fixing Burkholderia species different from B. vietnamiensis. In addition, this study shows the wide geographic distribution and substantial capability of N2-fixing Burkholderia spp. for colonizing diverse host plants in distantly separated environments. PMID:11375196

  9. 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.

  10. 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.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  12. 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.

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

    PubMed

    Lee, S E; Kang, S H

    2014-01-01

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

  15. 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.

  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. Examining sufficiency and equity in the geographic distribution of physicians in Japan: a longitudinal study

    PubMed Central

    Hara, Koji; Otsubo, Tetsuya; Kunisawa, Susumu; Imanaka, Yuichi

    2017-01-01

    Objectives The objective of this study was to longitudinally examine the geographic distribution of physicians in Japan with adjustment for healthcare demand according to changes in population age structure. Methods We examined trends in the number of physicians per 100 000 population in Japan's secondary medical areas (SMAs) from 2000 to 2014. Healthcare demand was adjusted using health expenditure per capita. Trends in the Gini coefficient and the number of SMAs with a low physician supply were analysed. A subgroup analysis was also conducted where SMAs were divided into 4 groups according to urban–rural classification and initial physician supply. Results The time-based changes in the Gini coefficient and the number of SMAs with a low physician supply indicated that the equity in physician distribution had worsened throughout the study period. The number of physicians per 100 000 population had seemingly increased in all groups, with increases of 22.9% and 34.5% in urban groups with higher and lower initial physician supply, respectively. However, after adjusting healthcare demand, physician supply decreased by 1.3% in the former group and increased by 3.5% in the latter group. Decreases were also observed in the rural groups, where the number of physicians decreased by 4.4% in the group with a higher initial physician supply and 7.6% in the group with a lower initial physician supply. Conclusions Although the total number of physicians increased in Japan, demand-adjusted physician supply decreased in recent years in all areas except for urban areas with a lower initial physician supply. In addition, the equity of physician distribution had consistently deteriorated since 2000. The results indicate that failing to adjust healthcare demand will produce misleading results, and that there is a need for major reform of Japan's healthcare system to improve physician distribution. PMID:28292766

  18. 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

  19. Geographic distribution and demography of Pithecia aequatorialis (pitheciidae) in Peruvian Amazonia.

    PubMed

    Aquino, Rolando; Cornejo, Fanny M; Pezo Lozano, Etersit; Heymann, Eckhard W

    2009-12-01

    To study the geographic distribution and demographic characteristics of Pithecia aequatorialis in Peruvian Amazonia, we undertook surveys and transect census in three river basins (Río Itaya, Río Tigre and Río Curaray) between 2004 and 2008. A total of 123 groups of P. aequatorialis was encountered during 1623 km of transect walks. Group size was uniform among the three areas (3.4-3.6 individuals), but surprisingly, population densities were higher in the area with strong hunting pressure (Río Itaya: 7.8 ind./km(2), vs. 5.6 and 5.9 km(2) in the Río Tigre and Río Curaray basins, respectively). The most common group composition included an adult pair with one offspring. Groups with more than one adult male and/or female accounted for 35% of sightings. Our observations extend P. aequatorialis range in Peru further south to the area between the Río Tigre and Río Corrientes, but exclude the area to the north between the Río Curaray and Río Napo. These findings are in contrast to previous distribution maps. P. aequatorialis was rarely seen in interspecific association during our censuses.

  20. Seasonal and Geographic Distribution of Cercarial Infection in Lymnaea gedrosiana (Pulmunata: Lymnaeidae) In North West Iran

    PubMed Central

    IMANI-BARAN, Abbas; YAKHCHALI, Mohammad; MALEKZADEH-VIAYEH, Reza; FARAHNAK, Ali

    2013-01-01

    Background Trematodes are a diverse group of endoparasites which require molluscan and vertebrate animals as intermediate and definitive hosts in their life cycle. The present study was carried out to determine the diversity and geographic distribution of infection with trematodes'cercariae in the snail Lymnaea gedrosiana from north-west Iran. Methods A total number of 6759 Lymnaeidae snails were collected from 28 snail habitats; of these L. gedrosiana was the prevalent snail (74.37%) which examined for cercarial infection by shedding method. Results The overall infection rate was 8.03%. The most frequent trematodes cercariae in the snail were xiphidiocercariae (81.98%), furcocercariae (32.26%), echinostome cercariae (5.19%), and monostome cercariae (1.24%). The highest infection rate in L. gedrosiana (100%) was with echinostome cercariae from Golestaneh in autumn. Conclusion Due to the important role of pond snails in transmission of cercariae to fish as a source of zoonotic diseases, it is essential to estimate the distribution and abundance of the snails and the rate of their infection with different trematodes’ cercariae, and establish control programs in each region. PMID:24454436

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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

  9. Geographical and altitudinal distribution of Brachycephalus (Anura: Brachycephalidae) endemic to the Brazilian Atlantic Rainforest.

    PubMed

    Bornschein, Marcos R; Firkowski, Carina R; Belmonte-Lopes, Ricardo; Corrêa, Leandro; Ribeiro, Luiz F; Morato, Sérgio A A; Antoniazzi-Jr, Reuber L; Reinert, Bianca L; Meyer, Andreas L S; Cini, Felipe A; Pie, Marcio R

    2016-01-01

    Mountains of the Brazilian Atlantic Forest can act as islands of cold and wet climate, leading to the isolation and speciation of species with low dispersal capacity, such as the toadlet species of the genus Brachycephalus. This genus is composed primarily by diurnal species, with miniaturized body sizes (<2.5 cm), inhabiting microhabitats in the leaf litter of montane forests. Still, little is known about the geographical distribution, altitudinal range, and ecological limits of most Brachycephalus species. In this study, we review the available data on the geographical and altitudinal distribution of Brachycephalus based on occurrence records compiled from literature and museums, both for the genus as a whole and separately for the three recently proposed groups of species (ephippium, didactylus, and pernix). The final ensemble dataset comprised 333 records, 120 localities, 28 described species, and six undescribed ones. Species were recorded in six relief units, the richest of which being the Serra do Mar, with 30 species. When the Serra do Mar is subdivided into three subunits, Northern, Central and Southern Serra do Mar, the number of species increase from north to the south, with records of six, nine, and 16 species, respectively. We were able to estimate the extent of occurrence of nearly half of the described species, and the resulting estimates indicate that many of them show remarkably small ranges, some of which less than 50 ha. Brachycephalus species are present from sea level to roughly 1,900 m a.s.l., with the highest richness being found between 751 and 1,000 m a.s.l. (21 spp.). The species with the broadest altitudinal range were B. didactylus (1,075 m) and Brachycephalus sp. 1 (1,035 m), both in the didactylus group, and B. ephippium (1,050 m), of the ephippium group. The broadest altitudinal amplitude for species of the pernix group was recorded for B. brunneus (535 m). The lowest altitudinal records for the pernix group were at 845 m a.s.l. in

  10. Geographical and altitudinal distribution of Brachycephalus (Anura: Brachycephalidae) endemic to the Brazilian Atlantic Rainforest

    PubMed Central

    Firkowski, Carina R.; Belmonte-Lopes, Ricardo; Corrêa, Leandro; Ribeiro, Luiz F.; Morato, Sérgio A.A.; Antoniazzi-Jr., Reuber L.; Reinert, Bianca L.; Meyer, Andreas L.S.; Cini, Felipe A.; Pie, Marcio R.

    2016-01-01

    Mountains of the Brazilian Atlantic Forest can act as islands of cold and wet climate, leading to the isolation and speciation of species with low dispersal capacity, such as the toadlet species of the genus Brachycephalus. This genus is composed primarily by diurnal species, with miniaturized body sizes (<2.5 cm), inhabiting microhabitats in the leaf litter of montane forests. Still, little is known about the geographical distribution, altitudinal range, and ecological limits of most Brachycephalus species. In this study, we review the available data on the geographical and altitudinal distribution of Brachycephalus based on occurrence records compiled from literature and museums, both for the genus as a whole and separately for the three recently proposed groups of species (ephippium, didactylus, and pernix). The final ensemble dataset comprised 333 records, 120 localities, 28 described species, and six undescribed ones. Species were recorded in six relief units, the richest of which being the Serra do Mar, with 30 species. When the Serra do Mar is subdivided into three subunits, Northern, Central and Southern Serra do Mar, the number of species increase from north to the south, with records of six, nine, and 16 species, respectively. We were able to estimate the extent of occurrence of nearly half of the described species, and the resulting estimates indicate that many of them show remarkably small ranges, some of which less than 50 ha. Brachycephalus species are present from sea level to roughly 1,900 m a.s.l., with the highest richness being found between 751 and 1,000 m a.s.l. (21 spp.). The species with the broadest altitudinal range were B. didactylus (1,075 m) and Brachycephalus sp. 1 (1,035 m), both in the didactylus group, and B. ephippium (1,050 m), of the ephippium group. The broadest altitudinal amplitude for species of the pernix group was recorded for B. brunneus (535 m). The lowest altitudinal records for the pernix group were at 845 m a.s.l. in

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

    PubMed Central

    Qin, Hongyu; Gao, Xiang; Wang, Hongbin; Xiao, Jianhua

    2016-01-01

    Fasciola hepatica is an important trematode parasite of economic importance that infests sheep and cattle worldwide. We conducted a detailed investigation into the spatial distribution of F. hepatica infestation in farmed sheep in Qinghai (Wutumeiren) province, Mainland China. Mathematical modelling was used to assess the inter-relationships between meteorological and geographical factors and the risk of F. hepatica infestation across the province. A capture enzyme-linked immunosorbent assay (ELISA) test (MM3-SERO) was used to detect F. hepatica infestation. A niche model based on the maximum entropy method (MaxEnt) was used to estimate the influence of meteorological and geographical factors on the observed spatial distribution of F. hepatica infestation. Results of jackknife analysis indicated that temperature, precipitation, solar radiation, digital elevation and slope were associated with the occurrence of F. hepatica infestation, and that infestation rates were significantly higher among animals from districts with a high percentage of grassland habitat. The findings indicate that meteorological and geographical factors may be important variables affecting the distribution of F. hepatica infestation and should be taken into account in the development of future surveillance and control programmes for fascioliasis. PMID:28000591

  12. Efficient workload management in geographically distributed data centers leveraging autoregressive models

    NASA Astrophysics Data System (ADS)

    Altomare, Albino; Cesario, Eugenio; Mastroianni, Carlo

    2016-10-01

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

  13. 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.

  14. 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

  15. Host specificity and geographical distribution of Eubothrium in European salmonid fish.

    PubMed

    Scholz, T; Kuchta, R; Shinn, A P; Snábel, V; Hanzelová, V

    2003-09-01

    The host specificity and distribution of Eubothrium crassum (Bloch, 1779) and Eubothrium salvelini (Schrank, 1790), morphologically fairly similar pseudophyllidean tapeworms parasitizing salmonid fish, were critically assessed on the basis of morphological and genetic evaluation of extensive material collected from different definitive hosts and geographical regions in Europe. Eubothrium crassum occurs in fish of the genera Salmo, i.e. salmon (S. salar - both freshwater and marine), sea trout (S. trutta trutta), brown trout (S. trutta fario), and lake trout (S. trutta lacustris), and also in Danubian salmon (Hucho hucho) and vendace (Coregonus albula). Eubothrium salvelini parasitizes Arctic char (Salvelinus alpinus) and brook trout (Salvelinus fontinalis) in Europe, and also whitefish (Coregonus wartmanni). Rainbow trout (Oncorhynchus mykiss), which is not a native European fish species, was found to be a suitable definitive host for both Eubothrium species, which may occur simultaneously in the same fish. Previous records of E. crassum in Arctic char and brook trout, and those of E. salvelini in fish of the genus Salmo were most probably misidentifications. Most studies of Eubothrium have involved salmonids from the northern part of Europe, with few records from southern and south-eastern Europe. This study also confirmed the reliability of the morphology of the apical disc for the discrimination of E. crassum and E. salvelini.

  16. Geographical distribution of acute symptoms after a train collision involving epichlorohydrin exposure.

    PubMed

    Radon, Katja; Rosenberger, Armin; Ehrenstein, Vera; Hoopmann, Michael; Basting, Imke; Tödt, Helga; Reichert, Jörg; Dressel, Holger; Schmid, Martina; Suchenwirth, Roland; Nowak, Dennis

    2006-09-01

    In September 2002, two freight trains collided in a northern German town. The inhabitants were potentially exposed to the probable human carcinogen epichlorohydrin. As no objective data on the level of exposure were available, we aimed to assess the geographical distribution of acute symptoms among local residents and subjects occupationally involved in the accident (e.g., firemen). A random sample of 932 adult local residents and 342 occupationally involved subjects were invited to answer a mail-in questionnaire. The main outcome measures were self-reported acute symptoms potentially associated with combustion products (e.g., irritation of the eyes, nose, or throat) and stress-related nonspecific symptoms. The main location during the first 26 h after the accident served as exposure proxy. For occupationally involved subjects, the time spent at the accident site was also used. The overall prevalence of symptoms potentially associated with combustion products was 9.8% for residents and 25.4% for occupationally involved subjects. After adjustment, subjects whose main location was close to the accident site had an increased risk for such symptoms. Among occupationally involved subjects the risk increased with duration at the accident site. Neither main location nor time at the accident site was significantly associated with non-specific symptoms. We could provide an example for designing and carrying out an epidemiologic study shortly after a local accident with potential public health impact. We could define parts of the population at increased risk for symptoms potentially specific for the exposure under study.

  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. Geographical distribution of perfluorinated compounds in fish from Minnesota lakes and rivers.

    PubMed

    Delinsky, Amy D; Strynar, Mark J; McCann, Patricia J; Varns, Jerry L; McMillan, Larry; Nakayama, Shoji F; Lindstrom, Andrew B

    2010-04-01

    In response to growing interest in human exposure to perfluorinated compounds (PFCs), the state of Minnesota measured and reported PFC concentrations in fish collected from the Minneapolis-St. Paul area. To better determine the geographical distribution of PFC contamination throughout Minnesota, fish were collected from 59 lakes throughout the state and several areas along the Mississippi River. Composite fish samples were analyzed for 10 PFC analytes by solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). PFOS (perfluorooctanesulfonate) was the most commonly detected PFC, occurring in 73% of fish from the Mississippi River but only 22% of fish from lakes. Fish from Mississippi River Pool 2 near the Minneapolis-St. Paul area had the highest levels of PFOS, whereas locations upstream had PFOS concentrations below 40 ng/g, the concentration at which Minnesota issues "one meal per week" fish consumption advice. Fish from most Minnesota lakes tested (88%) had PFOS concentrations below 3 ng/g. Two lakes, McCarrons and Zumbro, contained fish with PFOS levels above 40 ng/g. The results reported here will help researchers to better understand the extent of PFC contamination in Minnesota fish and evaluate potential sources of contamination and will provide a basis for comprehensive fish consumption advice.

  19. 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.

  20. 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.

  1. 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

  2. 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...

  3. 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

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

    PubMed

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

    2008-09-01

    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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. Species Diversity Distribution Patterns of Chinese Endemic Seed Plants Based on Geographical Regions

    PubMed Central

    Huang, Jihong; Ma, Keping; Huang, Jianhua

    2017-01-01

    Based on a great number of literatures, we established the database about the Chinese endemic seed plants and analyzed the compositions, growth form, distribution and angiosperm original families of them within three big natural areas and seven natural regions. The results indicate that the above characters of Chinese endemic plants take on relative rule at the different geographical scales. Among the three big natural areas, Eastern Monsoon area has the highest endemic plants richness, whereas Northwest Dryness area is the lowest. For life forms, herbs dominate. In contrast, the proportion of herbs of Eastern Monsoon area is remarkable under other two areas. Correspondingly the proportions of trees and shrubs are substantially higher than other two. For angiosperm original families, the number is the highest in Eastern Monsoon area, and lowest in Northwest Dryness area. On the other hand, among the seven natural regions, the humid and subtropical zone in Central and Southern China has the highest endemic plants richness, whereas the humid, hemi-humid region and temperate zone in Northeast China has the lowest. For life forms, the proportion of herbs tends to decrease from humid, hemi-humid region and temperate zone in Northeast China to humid and tropical zone in Southern China. Comparably, trees, shrubs and vines or lianas increase with the same directions. This fully represents these characters of Chinese endemic plants vary with latitudinal gradients. Furthermore, as to the number of endemic plants belonging to angiosperm original families, the number is the most in humid and subtropical zone in Center and Southern China, and tropical zone in Southern China in the next place. In contrast, the endemic plant of these two regions relatively is richer than that of The Qinghai-Tibet alpine and cold region. All above results sufficiently reflect that the Chinese endemic plants mainly distribute in Eastern Monsoon area, especially humid and subtropical zone in Center

  10. Photosynthesis pathways, ecological characteristics, and the geographical distribution of the Cyperaceae in Japan.

    PubMed

    Ueno, O; Takeda, T

    1992-02-01

    The nature of the photosynthetic pathways of Cyperaceae found in Japan were investigated on the basis of Kranz anatomy, the CO2 compensation concentration and previously reported data. Among 301 species (96% of all cyperaceous species recorded in the region), 58 species were classified as being C4 plants. These C4 species were scattered among the tribes Fimbristylideae, Lipocarpheae, Cypereae and Rhynchosporeae in the subfamily Cyperoideae. The genera Cyperus, Eleocharis and Rhynchospora included, in Japan, both C3 and C4 species within a single genus. Using these data, an analysis was made of the ecological characteristics and geographical distribution of the C3 and C4 species in Japan. Although cyperaceous species grow in markedly different environments, the majority were found in wet and aquatic areas (61%) or shaded areas, such as forest floors (20%). Most of the C3 species were also hygrophytes (58%) and forest-living species (25%), and C3 species growing in mesic and dry areas were relatively rare. The C4 species inhabited wet and aquatic (75%), mesic (13%) and dry areas (6%) and showed marked ecological characteristics with respect to soil-moisture conditions, unlike other C4 plants, although they were absent from shaded habitats. In order to determine the climatic factors that influence the relative floristic abundance of C3 and C4 members of the Cyperaceae in Japan, the ratios of number of C4 species to the total number of members of Cyperaceae (C4 percentage) in 16 representative locales were examined in terms of various climatic variables. There were strong positive correlations between the C4 percentage and temperature. Among the C3 groups of three subfamilies, there were different distributional trends for various temperature regimes. The C3 subfamily Caricoideae increased its relative contribution to the cyperaceous flora with a decrease in mean annual temperature, while the C3 subfamily Sclerioideae exhibited the opposite pattern. The C3 group of the

  11. Species Diversity Distribution Patterns of Chinese Endemic Seed Plants Based on Geographical Regions.

    PubMed

    Huang, Jihong; Ma, Keping; Huang, Jianhua

    2017-01-01

    Based on a great number of literatures, we established the database about the Chinese endemic seed plants and analyzed the compositions, growth form, distribution and angiosperm original families of them within three big natural areas and seven natural regions. The results indicate that the above characters of Chinese endemic plants take on relative rule at the different geographical scales. Among the three big natural areas, Eastern Monsoon area has the highest endemic plants richness, whereas Northwest Dryness area is the lowest. For life forms, herbs dominate. In contrast, the proportion of herbs of Eastern Monsoon area is remarkable under other two areas. Correspondingly the proportions of trees and shrubs are substantially higher than other two. For angiosperm original families, the number is the highest in Eastern Monsoon area, and lowest in Northwest Dryness area. On the other hand, among the seven natural regions, the humid and subtropical zone in Central and Southern China has the highest endemic plants richness, whereas the humid, hemi-humid region and temperate zone in Northeast China has the lowest. For life forms, the proportion of herbs tends to decrease from humid, hemi-humid region and temperate zone in Northeast China to humid and tropical zone in Southern China. Comparably, trees, shrubs and vines or lianas increase with the same directions. This fully represents these characters of Chinese endemic plants vary with latitudinal gradients. Furthermore, as to the number of endemic plants belonging to angiosperm original families, the number is the most in humid and subtropical zone in Center and Southern China, and tropical zone in Southern China in the next place. In contrast, the endemic plant of these two regions relatively is richer than that of The Qinghai-Tibet alpine and cold region. All above results sufficiently reflect that the Chinese endemic plants mainly distribute in Eastern Monsoon area, especially humid and subtropical zone in Center

  12. 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.

  13. Predictions of potential geographical distribution and quality of Schisandra sphenanthera under climate change.

    PubMed

    Guo, Yanlong; Wei, Haiyan; Lu, Chunyan; Gao, Bei; Gu, Wei

    2016-01-01

    Climate change will significantly affect plant distribution as well as the quality of medicinal plants. Although numerous studies have analyzed the effect of climate change on future habitats of plants through species distribution models (SDMs), few of them have incorporated the change of effective content of medicinal plants. Schisandra sphenanthera Rehd. et Wils. is an endangered traditional Chinese medical plant which is mainly located in the Qinling Mountains. Combining fuzzy theory and a maximum entropy model, we obtained current spatial distribution of quality assessment for S. spenanthera. Moreover, the future quality and distribution of S. spenanthera were also projected for the periods 2020s, 2050s and 2080s under three different climate change scenarios (SRES-A1B, SRES-A2 and SRES-B1 emission scenarios) described in the Special Report on Emissions Scenarios (SRES) of IPCC (Intergovernmental Panel on Climate Change). The results showed that the moderately suitable habitat of S. sphenanthera under all climate change scenarios remained relatively stable in the study area. The highly suitable habitat of S. sphenanthera would gradually decrease in the future and a higher decline rate of the highly suitable habitat area would occur under climate change scenarios SRES-A1B and SRES-A2. The result suggested that in the study area, there would be no more highly suitable habitat areas for S. sphenanthera when the annual mean temperature exceeds 20 °C or its annual precipitation exceeds 1,200 mm. Our results will be influential in the future ecological conservation and management of S. sphenanthera and can be taken as a reference for habitat suitability assessment research for other medicinal plants.

  14. Predictions of potential geographical distribution and quality of Schisandra sphenanthera under climate change

    PubMed Central

    Guo, Yanlong; Lu, Chunyan; Gao, Bei

    2016-01-01

    Climate change will significantly affect plant distribution as well as the quality of medicinal plants. Although numerous studies have analyzed the effect of climate change on future habitats of plants through species distribution models (SDMs), few of them have incorporated the change of effective content of medicinal plants. Schisandra sphenanthera Rehd. et Wils. is an endangered traditional Chinese medical plant which is mainly located in the Qinling Mountains. Combining fuzzy theory and a maximum entropy model, we obtained current spatial distribution of quality assessment for S. spenanthera. Moreover, the future quality and distribution of S. spenanthera were also projected for the periods 2020s, 2050s and 2080s under three different climate change scenarios (SRES-A1B, SRES-A2 and SRES-B1 emission scenarios) described in the Special Report on Emissions Scenarios (SRES) of IPCC (Intergovernmental Panel on Climate Change). The results showed that the moderately suitable habitat of S. sphenanthera under all climate change scenarios remained relatively stable in the study area. The highly suitable habitat of S. sphenanthera would gradually decrease in the future and a higher decline rate of the highly suitable habitat area would occur under climate change scenarios SRES-A1B and SRES-A2. The result suggested that in the study area, there would be no more highly suitable habitat areas for S. sphenanthera when the annual mean temperature exceeds 20 °C or its annual precipitation exceeds 1,200 mm. Our results will be influential in the future ecological conservation and management of S. sphenanthera and can be taken as a reference for habitat suitability assessment research for other medicinal plants. PMID:27781160

  15. 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

  16. Relationship between Emergency Restoration Time of Power Distribution Line after a Disaster and Geographical Characteristics of its Area

    NASA Astrophysics Data System (ADS)

    Sagai, Shigeo; Terano, Takao

    The effect of an outage caused by a disaster is serious to the society, because the power distribution line is a common basic infrastructure for life support. And the time estimation of emergency restoration process of power distribution line after a disaster is an emerging problem for the safety and security of the society. But the time estimation is a difficult problem and the only practical method in use is a simple approximation method, which doesn't take account of geographical characteristics of the objective area. So, we developed a method which can take account of the influences caused by the geographical characteristics of the objective area on the estimation of the emergency restoration. In this article, we describe an experimental analysis by the method.

  17. Geographical distribution and intra-domiciliary capture of sylvatic triatomines in La Convención province, Cusco, Peru.

    PubMed

    Torres V, Dina Beatriz; Cabrera, Rufino

    2010-01-01

    The geographical distribution and intra-domiciliary capture of sylvatic triatomines in three districts of the province of La Convención, Cusco, Peru are presented. In the district of Vilcabamba, eight adults of Rhodnius pictipes and five adults of Panstrongylus geniculatus were found. In the district of Ocobamba, 19 adults, 14 nymphs, and eggs of P. rufotuberculatus were found. In the district of Echarate, six adults and 10 nymphs of Eratyrus mucronatus, an adult of R. pictipes and P. geniculatus, and a nymph of P. rufotuberculatus were also found. The geographical distribution of E. mucronatus has extended to Cusco. This is the first report in Peru of household colonization by this triatomine.

  18. The geographic distribution of population health and contaminant body burden in gulf of Mexico oysters.

    PubMed

    Kim, Y; Powell, E N; Wade, T L; Presley, B J; Brooks, J M

    2001-07-01

    As part of NOAA's National Status and Trends Mussel Watch Program, oysters were sampled along the Gulf of Mexico coast each winter from 1986 to 1993 (The present analysis deals with 1986-1993 Mussel Watch data; the Mussel Watch project itself continues at this printing) and analyzed for trace metal, polynuclear aromatic hydrocarbons and pesticide body burden, plus a series of biological variables designed to assess population status and health. We identified contaminant and biological variables in which large-scale spatial processes played an important role in establishing population values by examining the likelihood that neighboring bays tended to have populations with body burdens or population attributes more similar than expected by chance. Local or watershed-dependent factors, such as land use and freshwater inflow, are important in controlling the bay-to-bay variation in body burden in most contaminants. However, the bay-to-bay variations in body burden of some metals (As, Cd, Hg, Ni, Se) appear to be principally influenced by larger-scale climatic factors. These metals and the biological variable shell length demonstrated a strong degree of similarity between bays over a large regional area reminiscent of the pattern shown by climatic factors, such as temperature and precipitation. In contrast, among the organics, none of the PAHs showed even a moderately strong climatic signal. Among the pesticides, only two did (dieldrin, total DDTs). These pesticides and the biological variables, reproductive stage and Perkinsus marinus prevalence and infection intensity, had spatial patterns that suggested both a local and a regional influence to their geographic distributions. This same pattern is exhibited by freshwater runoff. Metal contaminants also behaved distinctively compared to organics in the temporal influence of climate in establishing the interannual variability in body burden. For the organics, trends in interannual variability were strongly influenced by

  19. Distribution and Catabolic Diversity of 3-Chlorobenzoic Acid Degrading Bacteria Isolated from Geographically-Separated Pristine Soils

    DTIC Science & Technology

    1994-08-01

    could be a reflection of current interest in studying bacterial evolution , therefore, rapid development of new pathways is an attractive explanation...Ecology, Research on Microbial Evolution stock cultures (TFD strains). The TFD isolates were collected from a variety of sources and previously...PAGE OF A8STRACT 9954 A,, IL, 4*o DISTRIBUTION AND CATABOLIC DIVERSITY OF 3-CHLOROBENZOIC ACID DEGRADING BACTERIA ISOLATED FROM GEOGRAPHICALLY

  20. Geographic distribution, large-scale spatial structure and diversity of parasitoids of the seed-feeding beetle Acanthoscelides macrophthalmus.

    PubMed

    Wood, A; Haga, E B; Costa, V A; Rossi, M N

    2016-10-21

    Bruchine beetles are highly host-specific seed feeders during the larval stage. Although some specific parasitoid families have been recorded attacking bruchine beetles, most studies have been done at small spatial scales. Therefore, the current knowledge about the diversity and the geographic distribution of parasitoid species parasitizing bruchines is scarce, especially at a wide geographic area that extends over large distances through a latitudinal cline (i.e. large-scale spatial structure). The present study determined the species richness and evenness of parasitoids attacking the bruchine beetle Acanthoscelides macrophthalmus feeding on Leucaena leucocephala seeds, examined their geographic distribution, and characterized the large-scale spatial structure in parasitoid species composition. A total of 1420 parasitoids (all Hymenoptera) belonging to four families, five subfamilies and eight species were collected (genera: Horismenus, Paracrias, Urosigalphus, Stenocorse, Chryseida, Eupelmus). Most parasitoid species showed wide spatial distribution, high evenness in species abundance and the species richness estimators were close to stabilization (approximately eight species). Overall, greater similarity was observed in the species composition of plant populations near to each other than those farther apart, revealing a large-scale spatial structure in parasitoid species composition.

  1. Predicting the potential geographic distribution of cotton mealybug Phenacoccus solenopsis in India based on MAXENT ecological niche model.

    PubMed

    Fand, Babasaheb B; Kumar, Mahesh; Kamble, Ankush L

    2014-09-01

    Mealybug, Phenacoccus solenopsis Tinsley has recently emerged as a serious insect pest of cotton in India. This study demonstrates the use of Maxent algorithm for modeling the potential geographic distribution of P. solenopsis in India with presence-only data. Predictions were made based on the analysis of the relationship between 111 occurrence records for P. solenopsis and the corresponding current and future climate data defined on the study area. The climate data from worldclim database for current (1950-2000) and future (SRES A2 emission scenario for 2050) conditions were used. DIVA-GIS, an open source software for conducting spatial analysis was used for mapping the predictions from Maxent. The algorithm provided reasonable estimates of the species range indicating better discrimination of suitable and unsuitable areas for its occurrence in India under both present and future climatic conditions. The fit for the model as measured by AUC was high, with value of 0.930 for the training data and 0.895 for the test data, indicating the high level of discriminatory power for the Maxent. A Jackknife test for variable importance indicated that mean temperature of coldest quarter with highest gain value was the most important environmental variable determining the potential geographic distribution of P. solenopsis. The approaches used for delineating the ecological niche and prediction of potential geographic distribution are described briefly. Possible applications and limitations of the present modeling approach in future research and as a decision making tool in integrated pest management are discussed.

  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.

  3. 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

  4. 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.

  5. Geographic distribution and adaptive significance of genomic structural variants: an anthropological genetics perspective.

    PubMed

    Eaaswarkhanth, Muthukrishnan; Pavlidis, Pavlos; Gokcumen, Omer

    2014-01-01

    Anthropological geneticists have successfully used single-nucleotide and short tandem repeat variations across human genomes to reconstruct human history. These markers have also been used extensively to identify adaptive and phenotypic variation. The recent advent of high-throughput genomic technologies revealed an overlooked type of genomic variation: structural variants (SVs). In fact, some SVs may contribute to human adaptation in substantial and previously unexplored ways. SVs include deletions, insertions, duplications, inversions, and translocations of genomic segments that vary among individuals from the same species. SVs are much less numerous than single-nucleotide variants but account for at least seven times more variable base pairs than do single-nucleotide variants when two human genomes are compared. Moreover, recent studies have shown that SVs have higher mutation rates than single-nucleotide variants when the affected base pairs are considered, especially in certain parts of the genome. The null hypothesis for the evolution of SVs, as for single-nucleotide variants, is neutrality. Hence, drift is the primary force that shapes the current allelic distribution of most SVs. However, due to their size, a larger proportion of SVs appear to evolve under nonneutral forces (mostly purifying selection) than do single-nucleotide variants. In fact, as exemplified by several groundbreaking studies, SVs contribute to anthropologically relevant phenotypic variation and local adaptation among humans. In this review, we argue that with the advent of affordable genomic technologies, anthropological scrutiny of genomic structural variation emerges as a fertile area of inquiry to better understand human phenotypic variation. To motivate potential studies, we discuss scenarios through which structural variants (SVs) affect phenotypic variation among humans within an anthropological context. We further provide a methodological workflow in which we analyzed 1000 Genomes

  6. 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…

  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. 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

  9. Physicochemical conditions in affecting the distribution of spring phytoplankton community

    NASA Astrophysics Data System (ADS)

    Wei, Yuqiu; Liu, Haijiao; Zhang, Xiaodong; Xue, Bing; Munir, Sonia; Sun, Jun

    2017-03-01

    To better understand the physicochemical conditions in affecting regional distribution of phytoplankton community, one research cruise was carried out in the Bohai Sea and Yellow Sea during 3rd and 23th May, 2010. The phytoplankton community, including Bacillariophyta (105 taxa), Pyrrophyta (54 taxa), Chrysophyta (1 taxon) and Chlorophyta (2 taxa), had been identified and clearly described from six ecological provinces. And, the six ecological provinces were partitioned based on the top twenty dominant species related with notable physicochemical parameters. In general, the regional distributions of phytoplankton ecological provinces were predominantly influenced by the physicochemical properties induced by the variable water masses and circulations. The predominant diatoms in most of water samples showed well adaptability in turbulent and eutrophic conditions. However, several species of dinoflagellates e.g., Protoperidinium conicum, Protoperidinium triestinum, Protoperidinium sp. and Gymnodinium lohmanni preferred warmer, saltier and nutrient-poor environment. Moreover, the dinoflagellates with high frequency in the Yellow Sea might be transported from the Yellow Sea Warm Current. The horizontal distribution of phytoplankton was depicted by diatoms and controlled by phosphate concentration, while the vertical distribution was mainly supported by light and nutrients availability in the subsurface and bottom layers, respectively.

  10. 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

  11. 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.

  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. 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

  14. Trophic state and geographic gradients influence planktonic cyanobacterial diversity and distribution in New Zealand lakes.

    PubMed

    Wood, Susanna A; Maier, Marcia Y; Puddick, Jonathan; Pochon, Xavier; Zaiko, Anastasija; Dietrich, Daniel R; Hamilton, David P

    2017-02-01

    Cyanobacteria are commonly associated with eutrophic lakes, where they often form blooms and produce toxins. However, they are a ubiquitous component of phytoplankton in lakes of widely varying trophic status. We hypothesised that cyanobacterial diversity would vary among lakes of differing trophic status, but that the relative importance of geographical and hydromorphological characteristics driving these patterns would differ across trophic groups. DNA from 143 New Zealand lakes that spanned a range of geographic, hydromorphological and trophic gradients was analysed using automated rRNA intergenic spacer analysis and screened for genes involved in cyanotoxin production. Statistical analysis revealed significant delineation among cyanobacterial communities from different trophic classes. Multivariate regression indicated that geographical features (latitude, longitude and altitude) were significant in driving cyanobacterial community structure; however, partitioning of their effects varied among trophic categories. High-throughput sequencing was undertaken on selected samples to investigate their taxonomic composition. The most abundant and diverse (71 operational taxonomic units) taxon across all lake types was the picocyanobacteria genus Synechococcus Cyanotoxins (microcystins n = 23, anatoxins n = 1) were only detected in eutrophic lowland lakes. Collectively, these data infer that increasing eutrophication of lakes will have broad-scale impacts on planktonic cyanobacteria diversity and the prevalence of cyanotoxins.

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

    PubMed

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

    2013-01-01

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

  16. The health effects of exposure to arsenic-contaminated drinking water: a review by global geographical distribution.

    PubMed

    Huang, Lei; Wu, Haiyun; van der Kuijp, Tsering Jan

    2015-01-01

    Chronic arsenic exposure through drinking water has been a vigorously studied and debated subject. However, the existing literature does not allow for a thorough examination of the potential regional discrepancies that may arise among arsenic-related health outcomes. The purpose of this article is to provide an updated review of the literature on arsenic exposure and commonly discussed health effects according to global geographical distribution. This geographically segmented approach helps uncover the discrepancies in the health effects of arsenic. For instance, women are more susceptible than men to a few types of cancer in Taiwan, but not in other countries. Although skin cancer and arsenic exposure correlations have been discovered in Chile, Argentina, the United States, and Taiwan, no evident association was found in mainland China. We then propose several globally applicable recommendations to prevent and treat the further spread of arsenic poisoning and suggestions of future study designs and decision-making.

  17. 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.

  18. 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.

  19. Differentiation in drought tolerance mirrors the geographic distributions of alpine plants on the Qinghai-Tibet Plateau and adjacent highlands

    PubMed Central

    Meng, Li-Hua; Yang, Jie; Guo, Wen; Tian, Bin; Chen, Guang-Jie; Yang, Yong-Ping; Duan, Yuan-Wen

    2017-01-01

    Climatic tolerance, especially drought tolerance, is one of the major factors shaping the geographic distributions of plant species. Thus, the general decline in rainfall from the Himalaya-Hengduan Mountains (HHM) to the inner Qinghai-Tibet Plateau (QTP) might account for the significant differences in species distributions and richness between the two regions. To test this hypothesis, we conducted a water stress experiment using four Anisodus species (A. tanguticus, A. luridus, A. carniolicoides and A. acutangulus), which were treated with different levels of water stress in a glasshouse, and examined their differences in physiological responses. The results suggest that A. tanguticus, which inhabits the inner QTP, generally has higher fitness under severe water stress than the other species based on its high root:shoot ratio, long-term water use efficiency and photosynthetic rate, indicating that it possesses a genetically based drought tolerance mechanism. Our results suggest that plant species inhabiting the inner QTP may be more drought tolerant than those inhabiting the HHM regions. This provides a new example supporting the hypothesis that climatic tolerance plays a major role in shaping plant distributions on the QTP and its adjacent highlands and presents new insights into the patterns of geographic distribution and diversity of the plants inhabiting these areas. PMID:28195162

  20. Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese

    USGS Publications Warehouse

    Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.

    2013-01-01

    We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during

  1. Detection of the Dinozoans Pfiesteria piscicida and P. shumwayae: a review of detection methods and geographic distribution.

    PubMed

    Rublee, Parke A; Remington, David L; Schaefer, Eric F; Marshall, Michael M

    2005-01-01

    Molecular methods, including conventional PCR, real-time PCR, denaturing gradient gel electrophoresis, fluorescent fragment detection PCR, and fluorescent in situ hybridization, have all been developed for use in identifying and studying the distribution of the toxic dinoflagellates Pfiesteria piscicida and P. shumwayae. Application of the methods has demonstrated a worldwide distribution of both species and provided insight into their environmental tolerance range and temporal changes in distribution. Genetic variability among geographic locations generally appears low in rDNA genes, and detection of the organisms in ballast water is consistent with rapid dispersal or high gene flow among populations, but additional sequence data are needed to verify this hypothesis. The rapid development and application of these tools serves as a model for study of other microbial taxa and provides a basis for future development of tools that can simultaneously detect multiple targets.

  2. 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

  3. Geographical distribution of indoor radon and related geological characteristics in Bonghwa County, a provisional radon-prone area in Korea.

    PubMed

    Lee, E R; Chang, B U; Kim, H J; Song, M H; Kim, Y J

    2015-12-01

    The detailed indoor radon survey was conducted during a year (from September 2012 to August 2013) quarterly in Bonghwa county, one of the provisional radon-prone areas in Korea. The surveyed area was selected on the basis of previously conducted nationwide radon survey results. In order to minimise statistical and environmental uncertainties, ∼3 % of the entire dwellings were carefully selected based on the statistical annual report of Bonghwa county. The measurement is carried out by using solid-state nuclear track detector. The range of indoor radon concentration in each dwelling was 4.36-858 Bq m(-3) and that of annual effective dose due to inhaled radon of the resident in each dwelling was 0.19-23.5 mSv y(-1). Each dwelling was determined for geology criterion using one-way Analysis of Variance for the purpose of comparing indoor radon distribution with geology. Geographical distribution of indoor radon is closely related to the geological characteristics of basement rocks. In addition, the comparison between geographical distribution of indoor radon and terrestrial gamma radiation was done.

  4. Prediction of the potential geographic distribution of the ectomycorrhizal mushroom Tricholoma matsutake under multiple climate change scenarios

    PubMed Central

    Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei

    2017-01-01

    Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 106 km2, 0.14 × 106 km2, and 0.11 × 106 km2, respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species. PMID:28393865

  5. 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.

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

    PubMed Central

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

    2016-01-01

    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. 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.

  8. Trans-ionospheric pulse pairs (TIPPs): Their geographic distributions and seasonal variations

    NASA Astrophysics Data System (ADS)

    Zuelsdorf, R. S.; Strangeway, R. J.; Russell, C. T.; Casler, C.; Christian, H. J.; Franz, R. C.

    Since November 1993 the Blackbeard instrument aboard the ALEXIS satellite has detected pairs of pulses in the VHF band, known as Trans-Ionospheric Pulse Pairs (TIPPs). These pulses exhibit dispersion consistent with a source of sub- ionospheric origin. As of January 1997 over 850 TIPPs have been detected. The source of these emissions still remains a mystery, although it is believed that TIPPs are in some way related to thunderstorms as such storms provide a strong sub-ionospheric source and produce radiation in the same frequencies observed by Blackbeard. In an attempt to establish this connection we compare the geographic occurrence of TIPPs to that of lightning flashes observed from space by the Optical Transient Detector (OTD) on the Microlab-1 spacecraft. TIPP data run from 2 November 1993 to 19 November 1996. OTD data run from 1 May 1995 to 30 November 1996. The geographical occurrence of TIPPs and that of lightning flashes is strongly correlated. TIPPs occur less frequently during the winter months and their region of production moves southward in the North American sector similar in behavior to lightning activity.

  9. Cues of intraguild predators affect the distribution of intraguild prey.

    PubMed

    Choh, Yasuyuki; van der Hammen, Tessa; Sabelis, Maurice W; Janssen, Arne

    2010-06-01

    Theory on intraguild (IG) predation predicts that coexistence of IG-predators and IG-prey is only possible for a limited set of parameter values, suggesting that IG-predation would not be common in nature. This is in conflict with the observation that IG-predation occurs in many natural systems. One possible explanation for this difference might be antipredator behaviour of the IG-prey, resulting in decreased strength of IG-predation. We studied the distribution of an IG-prey, the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae), in response to cues of its IG-predator, the predatory mite Iphiseius degenerans. Shortly after release, the majority of IG-prey was found on the patch without cues of IG-predators, suggesting that they can rapidly assess predation risk. IG-prey also avoided patches where conspecific juveniles had been killed by IG-predators. Because it is well known that antipredator behaviour in prey is affected by the diet of the predator, we also tested whether IG-prey change their distribution in response to the food of the IG-predators (pollen or conspecific juveniles), but found no evidence for this. The IG-prey laid fewer eggs on patches with cues of IG-predators than on patches without cues. Hence, IG-prey changed their distribution and oviposition in response to cues of IG-predators. This might weaken the strength of IG-predation, possibly providing more opportunities for IG-prey and IG-predators to co-exist.

  10. 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.

  11. Use of molecular probes to assess geographic distribution of Pfiesteria species.

    PubMed

    Rublee, P A; Kempton, J W; Schaefer, E F; Allen, C; Harris, J; Oldach, D W; Bowers, H; Tengs, T; Burkholder, J M; Glasgow, H B

    2001-10-01

    We have developed multiple polymerase chain reaction (PCR)-based methods for the detection of Pfiesteria sp. in cultures and environmental samples. More than 2,100 water and sediment samples from estuarine sites of the U.S. Atlantic and gulf coasts were assayed for the presence of Pfiesteria piscicida Steidinger & Burkholder and Pfiesteria shumwayae Glasgow & Burkholder by PCR probing of extracted DNA. Positive results were found in about 3% of samples derived from routine monitoring of coastal waters and about 8% of sediments. The geographic range of both species was the same, ranging from New York to Texas. Pfiesteria spp. are likely common and generally benign inhabitants of coastal areas, but their presence maintains a potential for fish and human health problems.

  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. Topographic, latitudinal and climatic distribution of Pinus coulteri: geographic range limits are not at the edge of the climate envelope

    USGS Publications Warehouse

    Chardon, Nathalie I.; Cornwell, William K.; Flint, Lorraine E.; Flint, Alan L.; Ackerly, David D.

    2015-01-01

    With changing climate, many species are projected to move poleward or to higher elevations to track suitable climates. The prediction that species will move poleward assumes that geographically marginal populations are at the edge of the species' climatic range. We studied Pinus coulteri from the center to the northern (poleward) edge of its range, and examined three scenarios regarding the relationship between the geographic and climatic margins of a species' range. We used herbarium and iNaturalist.org records to identify P. coulteri sites, generated a species distribution model based on temperature, precipitation, climatic water deficit, and actual evapotranspiration, and projected suitability under future climate scenarios. In fourteen populations from the central to northern portions of the range, we conducted field studies and recorded elevation, slope and aspect (to estimate solar insolation) to examine relationships between local and regional distributions. We found that northern populations of P. coulteri do not occupy the cold or wet edge of the species' climatic range; mid-latitude, high elevation populations occupy the cold margin. Aspect and insolation of P. coulteri populations changed significantly across latitudes and elevations. Unexpectedly, northern, low-elevation stands occupy north-facing aspects and receive low insolation, while central, high-elevation stands grow on more south-facing aspects that receive higher insolation. Modeled future climate suitability is projected to be highest in the central, high elevation portion of the species range, and in low-lying coastal regions under some scenarios, with declining suitability in northern areas under most future scenarios. For P. coulteri, the lack of high elevation habitat combined with a major dispersal barrier may limit northward movement in response to a warming climate. Our analyses demonstrate the importance of distinguishing geographically vs. climatically marginal populations, and the

  14. 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.

  15. 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.

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

    PubMed

    Bessa Júnior, Francisco Narcísio; Nunes, Renan Flávio de França; de Souza, Marcos Antonio; de Medeiros, Antônio Carlos; Marinho, Maria Jocileide de Medeiros; Pereira, Wogelsanger Oliveira

    2013-09-01

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

  17. Spatial modeling of the geographic distribution of wildlife populations: A case study in the lower Mississippi River region

    USGS Publications Warehouse

    Ji, W.; Jeske, C.

    2000-01-01

    A geographic information system (GIS)-based spatial modeling approach was developed to study environmental and land use impacts on the geographic distribution of wintering northern pintails (Arias acuta) in the Lower Mississippi River region. Pintails were fitted with backpack radio transmitter packages at Catahoula Lake, LA, in October 1992-1994 and located weekly through the following March. Pintail survey data were converted into a digital database in ARC/INFO GIS format and integrated with environmental GIS data through a customized modeling interface. The study verified the relationship between pintail distributions and major environmental factors and developed a conceptual relation model. Visualization-based spatial simulations were used to display the movement patterns of specific population groups under spatial and temporal constraints. The spatial modeling helped understand the seasonal movement patterns of pintails in relation to their habitat usage in Arkansas and southwestern Louisiana for wintering and interchange situations among population groups wintering in Texas and southeastern Louisiana. (C) 2000 Elsevier Science B.V.

  18. 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.

  19. 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

  20. Geographical variation and the role of climate in leaf traits of a relict tree species across its distribution in China.

    PubMed

    Meng, H; Wei, X; Franklin, S B; Wu, H; Jiang, M

    2017-03-13

    Intraspecific trait variation and trait-climate relationships are crucial for understanding a species' response to climate change. However, these phenomena have rarely been studied for tree species. Euptelea pleiospermum is a relict tree species with a wide distribution in China that offers a novel opportunity to examine such relationships. Here, we measured 13 leaf traits of E. pleiospermum in 20 sites across its natural distribution in China. We investigated the extent of trait variation at local and regional scales, and developed geographic and climate models to explain trait variation at the regional scale. We documented intraspecific trait variation among leaf traits of E. pleiospermum at local and regional scales. Five traits exhibited relatively high trait variation: leaf area, leaf density and three leaf economic traits (leaf dry matter content, specific leaf area [SLA] and leaf phosphorus concentration). Significant trait-geography correlations were mediated by local climate. Most leaf trait variation could be explained (from 24% to 64%) by geographic or climate variables, except leaf width, leaf thickness, leaf dry matter content and leaf length-width ratio. Latitude and temperature were the strongest predictors of trait variation throughout the distribution of E. pleiospermum in China, and temperature explained more leaf trait variation than precipitation. In particular, we showed that leaves had longer petiole lengths, higher SLA and lower densities in northern E. pleiospermum populations. We suggest that northern E. pleiospermum populations are adapting to higher latitudinal environments via high growth rate (higher SLA) and low construction investment strategies (lower leaf densities), benefitting northern migration. Overall, we demonstrate that intraspecific trait variation reflects E. pleiospermum response to the local environment. We call for consideration of intraspecific trait variation to examine specific climate response questions. In

  1. 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.

  2. 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

  3. 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

  4. The geographical distribution of grey wolves (Canis lupus) in China: a systematic review

    PubMed Central

    WANG, Lu; MA, Ya-Ping; ZHOU, Qi-Jun; ZHANG, Ya-Ping; SAVOLAINEN, Peter; WANG, Guo-Dong

    2016-01-01

    The grey wolf (Canis lupus) is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolf in southern China is still highly controversial. Several well-known western literatures stated that there are no grey wolves in southern China, while the presence of grey wolf across China has been indicated in A Guide to the Mammals of China, published by Princeton University Press. It is essential to solve this discrepancy since dogs may have originated from grey wolfs in southern China. Therefore, we systematically investigated Chinese literatures about wild animal surveys and identified more than 100 articles and books that included information of the distribution of grey wolves in China. We also surveyed the collections of three Chinese natural museums and found 26 grey wolf skins specimens collected across China. Moreover, we investigated the fossil records of wolf in China and identified 25 archaeological sites with wolf remains including south China. In conclusion, with the comprehensive summary of Chinese literatures, museum specimens and fossil records, we demonstrate that grey wolves does distribute across all parts of the Chinese mainland, including the most southern parts of China. PMID:28105796

  5. Geographic location, network patterns and population distribution of rural settlements in Greece

    NASA Astrophysics Data System (ADS)

    Asimakopoulos, Avraam; Mogios, Emmanuel; Xenikos, Dimitrios G.

    2016-10-01

    Our work addresses the problem of how social networks are embedded in space, by studying the spread of human population over complex geomorphological terrain. We focus on villages or small cities up to a few thousand inhabitants located in mountainous areas in Greece. This terrain presents a familiar tree-like structure of valleys and land plateaus. Cities are found more often at lower altitudes and exhibit preference on south orientation. Furthermore, the population generally avoids flat land plateaus and river beds, preferring locations slightly uphill, away from the plateau edge. Despite the location diversity regarding geomorphological parameters, we find certain quantitative norms when we examine location and population distributions relative to the (man-made) transportation network. In particular, settlements at radial distance ℓ away from road network junctions have the same mean altitude, practically independent of ℓ ranging from a few meters to 10 km. Similarly, the distribution of the settlement population at any given ℓ is the same for all ℓ. Finally, the cumulative distribution of the number of rural cities n(ℓ) is fitted to the Weibull distribution, suggesting that human decisions for creating settlements could be paralleled to mechanisms typically attributed to this particular statistical distribution.

  6. The geographical distribution of grey wolves (Canis lupus) in China: a systematic review.

    PubMed

    Wang, Lu; Ma, Ya-Ping; Zhou, Qi-Jun; Zhang, Ya-Ping; Savolaimen, Peter; Wang, Guo-Dong

    2016-11-18

    The grey wolf (Canis lupus) is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolf in southern China is still highly controversial. Several well-known western literatures stated that there are no grey wolves in southern China, while the presence of grey wolf across China has been indicated in A Guide to the Mammals of China, published by Princeton University Press. It is essential to solve this discrepancy since dogs may have originated from grey wolfs in southern China. Therefore, we systematically investigated Chinese literatures about wild animal surveys and identified more than 100 articles and books that included information of the distribution of grey wolves in China. We also surveyed the collections of three Chinese natural museums and found 26 grey wolf skins specimens collected across China. Moreover, we investigated the fossil records of wolf in China and identified 25 archaeological sites with wolf remains including south China. In conclusion, with the comprehensive summary of Chinese literatures, museum specimens and fossil records, we demonstrate that grey wolves does distribute across all parts of the Chinese mainland, including the most southern parts of China.

  7. Disparities in the geographical distribution of authorship between invited and peer reviewed papers.

    PubMed

    Carson, D P; Eagles, J M

    1999-10-01

    Fifty issues of the British Medical Journal (BMJ), The Lancet, The British Journal of Psychiatry and Psychological Medicine were scrutinized. Papers were designated as invited or peer reviewed and the geographical location of the first author was recorded. For UK-based authors, the latitude and longitude of the host institution was noted and was allocated to one of the UK regions. Of invited papers 805 of 1227 (66%) were by UK-based authors compared with 1442 of 2896 peer reviewed papers (50%), odds ratio 1.92 (95% CI 1.67-2.21) with a similar pattern prevailing in each of the four journals. Within the UK, authorships of invited versus peer reviewed papers showed a preponderance of invited authors based in southeast England, odds ratio 1.30 (95% CI 1.09-1.56). For individual Journals, the Lancet and the British Journal of Psychiatry showed fewer regional disparities in authorship than the BMJ and Psychological Medicine. These disparities may lead to nationalism and parochiality in the content of invited papers. Journal editors may wish to review selection practices for authorship of invited papers.

  8. 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

  9. 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

  10. Geographic distribution and genetic diversity of Ceanothus-infective Frankia strains.

    PubMed

    Ritchie, N J; Myrold, D D

    1999-04-01

    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.

  11. Geographic distribution of human blastomycosis cases in Milwaukee, Wisconsin, USA: association with urban watersheds.

    PubMed

    Baumgardner, Dennis J; Knavel, Erica M; Steber, Dale; Swain, Geoffrey R

    2006-05-01

    Most studies of endemic blastomycosis and outbreaks have involved rural areas. Case homesites in rural Northern Wisconsin have been associated with waterways and sand soils. ARC-GIS was used to geocode addresses and to observe geographic features of homesites from 45 State-mandated reports of human blastomycosis in urban Milwaukee County, Southeastern Wisconsin 2000-2004. Each case property was directly observed, and houses and duplexes (N = 38) were compared with 151 same-street control homesites. Categorical data was analyzed using a chi-square or Fisher's exact test; continuous variables by Kruskal-Wallis test. One case cluster was seen on Milwaukee's North side where the estimated annual incidence was 2.8/100,000 compared to 0.96/100,000 for the entire county. Cases were less common in the most urbanized watersheds (0.49/100,000/yr) versus Lake Michigan shores (0.85) versus remaining three open watersheds (1.4) [P<0.01]. Case homesites averaged 1067 m to waterways and none were on sand soils. (Comparison is made to a Northern Wisconsin community where case homesites averaged 354 m to waterways, 24/25 were on sand soils and annual incidence was 74/100,000.) No unique features of case homesites were identified in Milwaukee County. In this urban area of Wisconsin, relatively low incidence rates may be explained, in part, by lower density of inland waterways and lack of sand soils, however, blastomycosis cases appear to be associated with open watersheds.

  12. [Psychosocial Care Centers for Children and Adolescents in Brazil: geographic distribution and user profile].

    PubMed

    Garcia, Grey Yuliet Ceballos; Santos, Darci Neves; Machado, Daiane Borges

    2015-12-01

    Few Brazilian studies have addressed the use of mental health services for children and adolescents. This study aimed to characterize the national distribution of Psychosocial Care Centers for Children and Adolescents (CAPSi) and describe the patient profile in this age group between 2008 and 2012. An ecological study was carried out, using records from the Authorizations for High-Complexity Procedures (APAC) system and the Brazilian National Registry of Healthcare Organizations (CNES). Socio-demographics and disease profile were analyzed. In 2014, 208 CAPSi were recorded in the CNES, distributed across 23 of Brazil's 27 states. Treatments included predominantly behavioral disorders (29.7%), developmental disorders (23.6%), and mental retardation (12.5%). CAPSi are insufficient and unequally distributed. The disease profile suggests the need for linkage between specialized mental health services and primary care, in addition to the inclusion of inter-sector work.

  13. MartiTracks: A Geometrical Approach for Identifying Geographical Patterns of Distribution

    PubMed Central

    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

  14. 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...

  15. Prevalence and geographical distribution of Papio hamadryas papillomavirus 1 (PhPV1) in Kenyan baboons.

    PubMed

    Chai, Daniel; Bassis, Christine M; Bergin, Ingrid L; Bell, Jason D; Nyachieo, Atunga; Gathumbi, Peter K

    2017-02-01

    Papio hamadryas papillomavirus (PhPV) 1, 2, and 3, are Alphapapillomaviruses that have been detected in Kenyan Olive baboons but the distribution is unknown. Therefore, cervical screening for PhPV1 was performed in baboons from various areas in Kenya using a nested polymerase chain reaction. The prevalence rate was 33%.

  16. 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 ...

  17. Geographical distribution of radiotherapy resources in Japan: investigating the inequitable distribution of human resources by using the Gini coefficient.

    PubMed

    Tanikawa, Takumi; Ohba, Hisateru; Ogasawara, Katsuhiko; Okuda, Yasuo; Ando, Yutaka

    2012-01-01

    This is a pilot study that aims to elucidate regional disparities in the distribution of medical resources in Japan. For this purpose, we employed the Gini coefficient (GC) in order to analyze the distribution of radiotherapy resources, which are allocated to each prefecture in Japan depending on the size of its population or physical area. Our study used data obtained from the 2005 and 2007 national surveys on the structure of radiation oncology in Japan, conducted by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO). Our analysis showed that the regional disparities regarding the radiation oncologists and radiotherapy technologists were small, and concluded that such resources were almost equitably distributed. However, medical physicists are inequitably distributed. Thus, policymakers should create and implement measures to train and retain medical physicists in areas with limited radiotherapy resources. Further, almost 26% of the secondary medical service areas lacked radiotherapy institutions. We attribute this observation to the existence of tertiary medical service areas, and almost all of prefectures face a shortage of such resources. Therefore, patients' accessibility to these resources in such areas should be improved.

  18. 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

  19. 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

  20. 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

  1. Exploring geographic distributions of high-risk water, sanitation, and hygiene practices and their association with child diarrhea in Uganda

    PubMed Central

    Hirai, Mitsuaki; Roess, Amira; Huang, Cheng; Graham, Jay

    2016-01-01

    Background High-risk water, sanitation, and hygiene (WASH) practices are still prevalent in most low-income countries. Because of limited access to WASH, children may be put at an increased risk of diarrheal diseases. Objectives This study aims to 1) develop a new measure of WASH-induced burden, the WASH Resource Index (WRI), and estimate its correlation with child diarrhea and an additive index of high-risk WASH practices; 2) explore the geographic distribution of high-risk WASH practices, child diarrhea, and summary indices at the cluster level; and 3) examine the association between the WRI and child diarrhea at the individual level. Design A sample of 7,019 children from the Uganda Demographic and Health Survey 2011 were included in this study. Principal component analysis was used to develop a WRI, and households were classified as WASH poorest, poorer, middle, richer, and richest. A hot spot analysis was conducted to assess whether and how high-risk WASH practices and child diarrhea were geographically clustered. A potential association between the WRI and child diarrhea was examined through a nested regression analysis. Results High-risk WASH practices were clustered at geographically distant regions from Kampala. The 2-week prevalence of child diarrhea, however, was concentrated in Eastern and East Central regions where high-risk WASH practices were not prevalent. At the individual level, none of the high-risk WASH practices were significantly associated with child diarrhea. Being in the highest WASH quintile was, however, significantly associated with 24.9% lower prevalence of child diarrhea compared to being in the lowest quintile (p<0.05). Conclusions Only a weak association was found between the WRI and child diarrhea in this study. Future research should explore the potential utility of the WRI to examine WASH-induced burden. PMID:27790971

  2. 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.

  3. Ecology and geographic distribution of Yersinia enterocolitica among livestock and wildlife in China.

    PubMed

    Liang, Junrong; Duan, Ran; Xia, Shengli; Hao, Qiong; Yang, Jinchuan; Xiao, Yuchun; Qiu, Haiyan; Shi, Guoxiang; Wang, Shukun; Gu, Wenpeng; Wang, Chunxiang; Wang, Mingliu; Tian, Kecheng; Luo, Longze; Yang, Meng; Tian, Huaiyu; Wang, Jiazheng; Jing, Huaiqi; Wang, Xin

    2015-07-09

    The results in this study show the prevalence of Yersinia enterocolitica varies in different animal species and regions of China. The highest prevalence is among pigs (12.91%), followed by dogs (9.80%), Ochotona curzoniae (plateau pica) (6.76%), chickens (4.50%), rodents (3.40%), cattle (2.78%) and sheep (0.89%). Pathogenic isolates comprised the majority of the Y. enterocolitica recovered from pigs (73.50%) and dogs (59.44%); whereas the nonpathogenic Y. enterocolitica made up most of poultry and wildlife recovered strains. A correlation analysis comparing the prevalence and geographic factors showed the isolation rate of Y. enterocolitica in pigs and dogs was negatively correlated with elevation (r=-0.50, P<0.05) and annual average air temperature (r=-0.43, P<0.05), but there was positive correlation with annual precipitation (r=0.43, P<0.05); conversely, the isolation rate from wildlife is positively correlated with elevation (r=0.3, P<0.05) contrary to the result seen in livestock. Twelve novel biotype 2 pathogenic Y. enterocolitica carried ail and ystB virulence genes, and one biotype 1A nonpathogenic strain positive with ail, ystB and ystA genes were isolated from Microtus fuscus (Qinghai vole) on plague foci of the Qinghai-Xizang plateau. The PFGE pattern K6GN11C30021 was predominant in pigs (44.25%) and patients (41.18%); K6GN11C30068 was predominant in dogs (40.16%). Animal isolates from the same region shared the same pattern (K6GN11C30021 and K6GN11C30012), indicating they may be from the same clone and arose through cross infection. Moreover, the identical PFGE pattern among local animals and diarrhea patients suggested that the animals may be the source of infections in these areas.

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

    PubMed

    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.

  5. 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

  6. Predicting geographic and ecological distributions of triatomine species in the southern Mexican state of Puebla using ecological niche modeling.

    PubMed

    Sandoval-Ruiz, C A; Zumaquero-Rios, J L; Rojas-Soto, O R

    2008-05-01

    We analyzed the geographic distribution using ecological niche modeling of three species of triatomines distributed in the Mexican state of Puebla. Punctual records were gathered for a period of 5 yr of fieldwork sampling. We used the genetic algorithm for rule-set production (GARP) to achieve the potential distribution of the ecological niche of triatomines. The models showed that Triatoma barberi and Meccus pallidipennis are sympatric and widely distributed in the central-southern part of the state, whereas T. dimidata is restricted to the northern mountains of the state with no overlapping among other species, M. bassolsae was not modeled because of the scarce number of locality records. We highlighted the warm and dry conditions in southern Puebla as important potential areas for triatomine presence. Finally, we correlated the species potential presence with the human population at risk of acquiring Chagas disease by vector-borne transmission; it is showed that M. pallidipennis presents the highest values of both ecological and poverty risk scenarios representing the main potential vector in the state.

  7. Force distribution affects vibrational properties in hard-sphere glasses.

    PubMed

    DeGiuli, Eric; Lerner, Edan; Brito, Carolina; Wyart, Matthieu

    2014-12-02

    We theoretically and numerically study the elastic properties of hard-sphere glasses and provide a real-space description of their mechanical stability. In contrast to repulsive particles at zero temperature, we argue that the presence of certain pairs of particles interacting with a small force f soften elastic properties. This softening affects the exponents characterizing elasticity at high pressure, leading to experimentally testable predictions. Denoting P(f) ~ f(θ(e)), the force distribution of such pairs and ϕ(c) the packing fraction at which pressure diverges, we predict that (i) the density of states has a low-frequency peak at a scale ω*, rising up to it as D(ω) ~ ω(2+a), and decaying above ω* as D(ω) ~ ω(-a) where a = (1 - θ(e))/(3 + θ(e)) and ω is the frequency, (ii) shear modulus and mean-squared displacement are inversely proportional with ⟨δR²⟩ ~ 1/μ ~ (ϕ(c) - ϕ)(κ), where κ = 2 - 2/(3 + θ(e)), and (iii) continuum elasticity breaks down on a scale ℓ(c) ~ 1/√(δz) ~ (ϕ(c) - ϕ)(-b), where b = (1 + θ(e))/(6 + 2θ(e)) and δz = z - 2d, where z is the coordination and d the spatial dimension. We numerically test (i) and provide data supporting that θ(e) ≈ 0.41 in our bidisperse system, independently of system preparation in two and three dimensions, leading to κ ≈ 1.41, a ≈ 0.17, and b ≈ 0.21. Our results for the mean-square displacement are consistent with a recent exact replica computation for d = ∞, whereas some observations differ, as rationalized by the present approach.

  8. 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.

  9. 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

  10. 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

  11. Geographical Distribution and Interseasonal Variability of Tropical Deep Convection: UARS MLS Observations and Analyses

    DTIC Science & Technology

    2004-01-01

    measurements of small-scale humidity fea- tures associated with overshooting convection as well as the spatial and temporal distribution of these...mechanisms that could cause this anticorrelation of temperature and cloudiness during this time scale were discussed in their report (e.g., Pinatubo eruption ... Mount Pinatubo H2SO4/H2O aero- sol on ice nucleation in the upper troposphere using a global chemistry and transport model, J. Geophys. Res., 107(D12

  12. 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.

  13. 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

  14. 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

  15. The Geographic Distribution, Ownership, Prices, and Scope of Practice at Retail Clinics

    PubMed Central

    Rudavsky, Rena; Pollack, Craig Evan; Mehrotra, Ateev

    2009-01-01

    BACKGROUND As a new model of care in the United States (US), retail clinics have generated much interest. Located physically within a retail store, they provide simple acute and preventive care services for a fixed price and without an appointment. OBJECTIVE To describe where retail clinics have opened in the US, their ownership structure, scope of practice, prices, acceptance of insurance, and the fraction of the population that lives within a short driving distance of a clinic. DESIGN Cross-sectional descriptive study SAMPLE All retail clinics operating in the US as of August 2008 MEASUREMENTS Population living within five and ten-minute driving distances of a retail clinic RESULTS In August 2008, 42 operators ran 982 clinics in 33 states; 88.4% were located in urban areas. An estimated 13.4% and 35.8% of the US urban population lives within a five-minute and ten-minute driving distance respectively from a retail clinic. The proportion of the population that lives close to a retail clinic is higher than 50 percent in some cities such as Nashville (56.7% five-minute, 93.7% ten-minute) and Minneapolis-St. Paul, MN (50.9%, 96.0%). The majority of retail clinic operators (25, 59.5%) are hospital chains and/or physician groups, but they only operate 11.4% of the clinics nationally. Simple acute conditions, skin conditions, and immunizations make up the majority of retail clinics’ limited scope of practice. Across operators, those without insurance paid on average $78 for a sore throat visit and $63 for an adult tetanus booster vaccine. In a random sample of clinics, we found that 97% accepted private insurance, 93% accepted Medicare fee-for-service, and 60% accepted some form of Medicaid. LIMITATIONS Geographic access is only one of many factors that influence whether an individual visits a retail clinic CONCLUSIONS Retail clinics can provide care for simple acute conditions and immunizations for a significant segment of the urban US population. PRIMARY FUNDING

  16. 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.

  17. 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

  18. Correlations of geographic distribution and temperature of embryonic development with the nuclear DNA content in the Salamandridae (Urodela, Amphibia).

    PubMed

    Litvinchuk, Spartak N; Rosanov, Jury M; Borkin, Leo J

    2007-04-01

    We used flow cytometry to measure the nuclear DNA content in erythrocytes of 27 salamandrid species. Across these species, diploid genome size varied more than 2 fold (51.3-104.4 pg). According to genome size and geographic distribution, 3 groups of newt species were recognized: West Palearctics with smaller amounts of nuclear DNA; Nearctic, with intermediate values; and East Asiatic, with higher genome sizes. Viviparous West Palearctic salamanders differed from most of the oviparous West Palearctic newts in possessing larger genome sizes. The nuclear DNA content strongly correlates with species range limits. At the same temperature, embryos of salamandrid species with larger genome sizes have a markedly longer developmental time than those with smaller genomes. We present an analysis of the relationships between the amount of nuclear DNA and water temperature at the breeding sites.

  19. 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.

  20. 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

  1. 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

    2011-01-06

    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.

  2. 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

  3. 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

  4. Diversity, geographic distribution, and habitat-specific variations of microbiota in natural populations of the chicken mite, Dermanyssus gallinae.

    PubMed

    Moro, Claire Valiente; Thioulouse, Jean; Chauve, Claude; Zenner, Lionel

    2011-07-01

    Dermanyssus gallinae is considered to be the most economically significant ectoparasite to affect egg-laying poultry in Europe. This mite can also act as a vector for a number of pathogens. The array of bacteria associated with D. gallinae mites could provide insight into the biology and population dynamics of arthropods, but at the present time little information is available. To understand the intra- and interpopulation diversity of its associated microbiota, we analyzed the whole internal bacterial community of natural populations of D. gallinae originating from two types of poultry farm habitats (standard and free-range) in two regions of France (Brittany and the Rhone-Alpes). Total DNA was extracted from individual or pooled mites, and polymerase chain reaction temporal temperature gradient gel electrophoresis of 16S rRNA was then done to separate bacterial DNA fragments associated with the host arthropod. A large diversity of bacteria was detected, but principally firmicutes and gamma-Proteobacteria. Between-group analyses of temporal temperature gradient gel electrophoresis-banding patterns revealed that bacterial populations clustered into categories according to their geographic origin and the habitat specifics of the farms. Some degree of stability of bacterial populations was observed within a specific time scale. These results suggest that environmental factors either recent (e.g., poultry farming practices) or long-standing (e.g., geographic isolation) may affect the bacterial communities present in D. gallinae. Further knowledge of the microbiota associated with D. gallinae and its variation would indeed offer new perspectives for biological control methods to prevent the establishment, proliferation, and transmission of pathogenic bacteria.

  5. 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.

  6. 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

  7. Geographic distribution of the chytrid pathogen Batrachochytrium dendrobatidis among mountain amphibians along the Italian peninsula.

    PubMed

    Zampiglia, Mauro; Canestrelli, Daniele; Chiocchio, Andrea; Nascetti, Giuseppe

    2013-11-25

    The amphibian chytrid pathogen Batrachochytrium dendrobatidis (Bd) is considered a major cause of amphibian population declines, particularly in montane areas. Here, we investigated the presence and distribution of Bd among populations of 3 mid- to high-altitude species spanning the entire Italian peninsula (486 individuals from 39 sites overall): the stream frog Rana italica, the fire salamander Salamandra salamandra gigliolii, and the alpine newt Mesotriton alpestris apuanus. We found Bd in all of the analyzed species. Despite the widespread distribution of the pathogen, its overall prevalence (6, 9 and 19%, respectively) was lower than previously reported for the endangered Apennine yellow-bellied toad Bombina pachypus (62.5%). Moreover, several populations of the species studied here were not infected, even at sites where Bd has been detected in other host species. When coupled with the lack of evidence for Bd-related mortalities in these species in peninsular Italy, these results suggest that mechanisms of resistance and/or tolerance are protecting populations of these species from the pathogenic activity of Bd. Nevertheless, in light of the dynamic pattern of Bd-host interactions reported in other studies, of Bd-related mortalities in at least 1 study species (S. s. salamandra) in other areas, and the ongoing climate changes in montane environments, we suggest that the occurrence of Bd should be considered a potential threat to the long-term persistence of these species, and urge the implementation of monitoring and conservation plans.

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

    PubMed Central

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

    2016-01-01

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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. A Virtual Geophysical Network: Using Industry Standard Technology to Link Geographically Distributed Sensors and Data Centers

    NASA Astrophysics Data System (ADS)

    Ahern, T. K.; Benson, R. B.; Crotwell, H. P.

    2003-12-01

    The IRIS Data Management System has long supported distributed data centers as a method of providing scientific researchers access to data from seismological networks around the world. For nearly a decade, the NetDC system used email as the method through which users could access data centers located around the globe in a seamless fashion. More recently the IRIS DMC has partnered with the University of South Carolina to develop a new method through which a virtual data center can be created. The Common Object Request Broker Architecture (CORBA) technology is an industry standard distributed computing architecture. Traditionally used by major corporations, IRIS has developed a Data Handling Interface (DHI) system that is capable of connecting services at participating data centers (servers) to applications running on end-users computing platforms (clients). For seismology we have identified three services. 1) A network service that provides information about geophysical observatories around the world such as where the sensors exist, what types of information are recorded on the sensors, and calibration information that allows proper use of the data, 2) an event service that allows applications to access information about earthquakes and seismological events and 3) waveform services that allow users to gain access to seismograms or time series data from other geophysical sensors. Seismological Data Centers operate the servers thereby allowing a variety of client applications to directly access the information at these data centers. Currently IRIS, the U. of South Carolina, UC Berkeley, and a European Data Center (ORFEUS) have been involved in the DHI project. This talk will highlight some of the DHI enabled clients that allow geophysical information to be directly transferred to the clients. Since the data center servers appear with the same interface specification (Interface Definition Language) a client that can talk to one DHI server can talk to any DHI enabled

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

    PubMed

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

    2013-06-01

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

  15. Geographical Information Systems (GIS) as a Simple Tool to Aid Modelling of Particulate Waste Distribution at Marine Fish Cage Sites

    NASA Astrophysics Data System (ADS)

    Pérez, O. M.; Telfer, T. C.; Beveridge, M. C. M.; Ross, L. G.

    2002-04-01

    Deposition of particulate organic waste from marine fish farm cages on to sea-bed sediments can cause major changes to the benthic ecosystem. Validated spatial models are considered as the most cost-effective tools for predicting environmental impacts. An improved version of an existing predictive particulate waste distribution model for farmed Atlantic salmon ( Salmo salar L.) is presented, which uses Geographic Information Systems (GIS) combined with a spreadsheet. The model presented uses existing distribution algorithms but also incorporates functions to calculate feed loading for all the cages within a pontoon independently, spreads the input load over the whole cage area and simulates post-depositional distribution of the carbon. The model uses approximate estimates of feed and faecal waste derived from dietary considerations (mass balance model) and separate, unique settling velocities for waste feed and faecal particles. The model incorporates values of current speed and direction recorded over spring and neap tides. Output from the model is in the form of a contour plot of organic carbon (g C m -2), showing distribution of the particulate organic carbon material as deposited on the sea-bed. During this study using hydrographic data collected from near a fish farm, the model predicted a smooth gradient of sediment carbon concentrations which decreased with distance from the cages. Model performance was validated using measured levels of sediment carbon, and showed a significant correlation between predicted and actual sediment loading (R=0·7; P <0·01). The differences between predicted and measured quantities of carbon found at some sampling stations are likely to be due to processes not included in the model, such as small differences in bathymetry, differences in bottom type which may have increased or decreased the carbon distribution through saltation, or natural variation in the sediment composition.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Geographic Information Systems

    PubMed Central

    Wieczorek, William F.; Delmerico, Alan M.

    2009-01-01

    This chapter presents an overview of the development, capabilities, and utilization of geographic information systems (GIS). There are nearly an unlimited number of applications that are relevant to GIS because virtually all human interactions, natural and man-made features, resources, and populations have a geographic component. Everything happens somewhere and the location often has a role that affects what occurs. This role is often called spatial dependence or spatial autocorrelation, which exists when a phenomenon is not randomly geographically distributed. GIS has a number of key capabilities that are needed to conduct a spatial analysis to assess this spatial dependence. This chapter presents these capabilities (e.g., georeferencing, adjacency/distance measures, overlays) and provides a case study to illustrate how GIS can be used for both research and planning. Although GIS has developed into a relatively mature application for basic functions, development is needed to more seamlessly integrate spatial statistics and models. The issue of location, especially the geography of human activities, interactions between humanity and nature, and the distribution and location of natural resources and features, is one of the most basic elements of scientific inquiry. Conceptualizations and physical maps of geographic space have existed since the beginning of time because all human activity takes place in a geographic context. Representing objects in space, basically where things are located, is a critical aspect of the natural, social, and applied sciences. Throughout history there have been many methods of characterizing geographic space, especially maps created by artists, mariners, and others eventually leading to the development of the field of cartography. It is no surprise that the digital age has launched a major effort to utilize geographic data, but not just as maps. A geographic information system (GIS) facilitates the collection, analysis, and reporting of

  1. Geographic Information Systems.

    PubMed

    Wieczorek, William F; Delmerico, Alan M

    2009-01-01

    This chapter presents an overview of the development, capabilities, and utilization of geographic information systems (GIS). There are nearly an unlimited number of applications that are relevant to GIS because virtually all human interactions, natural and man-made features, resources, and populations have a geographic component. Everything happens somewhere and the location often has a role that affects what occurs. This role is often called spatial dependence or spatial autocorrelation, which exists when a phenomenon is not randomly geographically distributed. GIS has a number of key capabilities that are needed to conduct a spatial analysis to assess this spatial dependence. This chapter presents these capabilities (e.g., georeferencing, adjacency/distance measures, overlays) and provides a case study to illustrate how GIS can be used for both research and planning. Although GIS has developed into a relatively mature application for basic functions, development is needed to more seamlessly integrate spatial statistics and models.The issue of location, especially the geography of human activities, interactions between humanity and nature, and the distribution and location of natural resources and features, is one of the most basic elements of scientific inquiry. Conceptualizations and physical maps of geographic space have existed since the beginning of time because all human activity takes place in a geographic context. Representing objects in space, basically where things are located, is a critical aspect of the natural, social, and applied sciences. Throughout history there have been many methods of characterizing geographic space, especially maps created by artists, mariners, and others eventually leading to the development of the field of cartography. It is no surprise that the digital age has launched a major effort to utilize geographic data, but not just as maps. A geographic information system (GIS) facilitates the collection, analysis, and reporting of

  2. 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.

  3. Geographic distribution of white-tailed deer with ticks and antibodies to Borrelia burgdorferi in Connecticut.

    PubMed Central

    Magnarelli, L. A.; Anderson, J. F.; Cartter, M. L.

    1993-01-01

    Ticks and blood specimens were collected from white-tailed deer (Odocoileus virginianus) in Connecticut and analyzed to identify foci for Lyme borreliosis. Males and females of Ixodes scapularis, the chief vector of Borrelia burgdorferi, were collected from deer in five of eight counties during 1989-1991. Analysis by indirect fluorescent antibody (IFA) staining of midgut tissues showed that prevalence of infection was highest (9.5% of 367 ticks) in south central and southeastern Connecticut. Infected I. scapularis also were collected from southwestern regions of the state (12.1% of 99 ticks), but prevalence of infection in northern counties was considerably lower (0.8% of 124 ticks). Deer sera, obtained in 1980 and 1989-1991, were analyzed by an enzyme-linked immunosorbent assay or by IFA staining methods. Antibodies to B. burgdorferi were detected in sera collected from all eight counties in Connecticut. Deer had been infected by this spirochete in at least 50 towns, 17 (34%) of which are in south central and southeastern parts of the state. Borrelia burgdorferi is widely distributed in I. scapularis populations in Connecticut. PMID:8256460

  4. 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

  5. Geographical distribution of Angiostrongylus vasorum in foxes (Vulpes vulpes) in the Republic of Ireland.

    PubMed

    McCarthy, G; Ferrand, M; De Waal, T; Zintl, A; McGrath, G; Byrne, W; O'Neill, E J

    2016-04-01

    The reported incidence of the metastrongylid nematode Angiostrongylus vasorum, that infects dogs and other canids, is increasing worldwide outside recognized endemic foci. This apparent expansion of the parasite's range is causing concern to veterinary clinicians as the disease caused in dogs can be life threatening and its treatment is not straightforward. The red fox is thought to be a reservoir host for dogs. To investigate the spatial distribution of infection in foxes in Ireland, the hearts and lungs of 542 foxes from all over Ireland were examined. The incidence of infection was found to be 39·9% [95% confidence interval (CI) 35·7-44·1] with positive samples occurring in each of the country's 26 counties. This report confirms that the parasite is endemic in Ireland and the overall prevalence is the second highest in Europe. This is the first survey of A. vasorum infection in Irish foxes and highlights the potential exposure of the Irish dog population to high risk of cross-infection. Additionally, Crenosoma vulpis was found in seven of the foxes, a parasite not previously reported in the Irish fox.

  6. Geographical distribution of arsenic in sediments within the Rio Conchos Basin, Mexico

    NASA Astrophysics Data System (ADS)

    Gutierrez, Melida; Alarcón-Herrera, M. Teresa; Camacho, Lucy M.

    2009-04-01

    Arsenic (As) content of sediments from the Rio Conchos and Rio San Pedro in northern Mexico were measured to determine if this toxic metalloid had accumulated to unsafe levels to humans and aquatic life. The spatial distribution of As in each of the six clusters of river and arroyo sediments was analyzed to determine variations with respect to background levels and to infer about potential As sources and sinks. In the northern part of the study area, background concentrations varied little throughout the area and concentrations in river sediments were close to background levels. In the southern part, however, the content of As in arroyo sediment contained a wider range of values and anomalous concentrations. The latter could be traced in part to the presence of mine tailings. As concentrations were below the limit in all studied river stretches and thus do not pose an immediate threat to the river environment, but As content in reservoir sediments exceeded the guideline values. Reservoirs seem to act as a sink for As, warranting closer observation and monitoring.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. Four peroxidase Loci in red-fruited tomato species: genetics and geographic distribution.

    PubMed

    Rick, C M; Zobel, R W; Fobes, J F

    1974-03-01

    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-3(n) 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.

  12. Shifting fungal endophyte communities colonize Bouteloua gracilis: effect of host tissue and geographical distribution.

    PubMed

    Herrera, José; Khidir, Hana H; Eudy, Douglas M; Porras-Alfaro, Andrea; Natvig, Donald O; Sinsabaugh, Robert L

    2010-01-01

    Communities of root-associated fungi (RAF) commonly have been studied under the auspices of arbuscular mycorrhizal fungi (AMF) or ectomycorrhizal fungi. However many studies now indicate that other groups of endophytic RAF, including dark septate endophytes (DSE) are more abundant in some plants and environments. The common forage grass, Bouteloua gracilis, was used as a model to examine whether RAF also colonize different organs within the same plant and to compare RAF communities from sites across North America, spanning the latitudinal range of B. gracilis (from Canada to Mexico). We compared the RAF communities of organs within individual plants at one site and within plant roots among six sites. With the possible exception of one group related to genus Paraphaeosphaeria there was little evidence that RAF colonized vertically beyond the crowns. Furthermore, although there was some variation in the constitution of rare members of the RAF communities, several taxonomically related groups dominated the RAF community at all sites. These dominant taxa included members in the Pleosporales (related to the DSE, Paraphaeosphaeria spp.), Agaricales (related to Moniliophthora spp., or Campanella spp.) and Hypocreales (related to Fusarium spp.). AMF were notable by their near absence. Similar phylotypes from the dominant groups clustered around adjacent sites so that similarity of the RAF communities was negatively correlated to site inter-distance and the RAF communities appeared to group by country. These results increase the possibility that at least some of these common and widely distributed core members of the RAF community form important, intimate and long lasting relationships with grasses.

  13. Geographical and genospecies distribution of Borrelia burgdorferi sensu lato DNA detected in humans in the USA.

    PubMed

    Clark, Kerry L; Leydet, Brian F; Threlkeld, Clifford

    2014-05-01

    The present study investigated the cause of illness in human patients primarily in the southern USA with suspected Lyme disease based on erythema migrans-like skin lesions and/or symptoms consistent with early localized or late disseminated Lyme borreliosis. The study also included some patients from other states throughout the USA. Several PCR assays specific for either members of the genus Borrelia or only for Lyme group Borrelia spp. (Borrelia burgdorferi sensu lato), and DNA sequence analysis, were used to identify Borrelia spp. DNA in blood and skin biopsy samples from human patients. B. burgdorferi sensu lato DNA was found in both blood and skin biopsy samples from patients residing in the southern states and elsewhere in the USA, but no evidence of DNA from other Borrelia spp. was detected. Based on phylogenetic analysis of partial flagellin (flaB) gene sequences, strains that clustered separately with B. burgdorferi sensu stricto, Borrelia americana or Borrelia andersonii were associated with Lyme disease-like signs and symptoms in patients from the southern states, as well as from some other areas of the country. Strains most similar to B. burgdorferi sensu stricto and B. americana were found most commonly and appeared to be widely distributed among patients residing throughout the USA. The study findings suggest that human cases of Lyme disease in the southern USA may be more common than previously recognized and may also be caused by more than one species of B. burgdorferi sensu lato. This study provides further evidence that B. burgdorferi sensu stricto is not the only species associated with signs and/or symptoms consistent with Lyme borreliosis in the USA.

  14. Geographic distribution of the mid-continent population of sandhill cranes and related management applications

    USGS Publications Warehouse

    Krapu, Gary L.; Brandt, David A.; Jones, Kenneth L.; Johnson, Douglas H.

    2011-01-01

    The Mid-continent Population (MCP) of sandhill cranes (Grus canadensis) is widely hunted in North America and is separated into the Gulf Coast Subpopulation and Western Subpopulation for management purposes. Effective harvest management of the MCP requires detailed knowledge of breeding distribution of subspecies and subpopulations, chronology of their use of fall staging areas and wintering grounds, and exposure to and harvest from hunting. To address these information needs, we tagged 153 sandhill cranes with Platform Transmitting Terminals (PTTs) during 22 February–12 April 1998–2003 in the Central and North Platte River valleys of south-central Nebraska. We monitored PTT-tagged sandhill cranes, hereafter tagged cranes, from their arrival to departure from breeding grounds, during their fall migration, and throughout winter using the Argos satellite tracking system. The tracking effort yielded 74,041 useable locations over 49,350 tag days; median duration of tracking of individual cranes was 352 days and 73 cranes were tracked >12 months. Genetic sequencing of mitochondrial DNA (mtDNA) from blood samples taken from each of our random sample of tagged cranes indicated 64% were G. c. canadensis and 34% were Grus canadensis tabida. Tagged cranes during the breeding season settled in northern temperate, subarctic, and arctic North America (U.S. [23%, n = 35], Canada [57%, n = 87]) and arctic regions of northeast Asia (Russia [20%, n = 31]). Distribution of tagged cranes by breeding affiliation was as follows: Western Alaska–Siberia (WA–S, 42 ± 4% [SE]), northern Canada–Nunavut (NC–N, 21 ± 4%), west-central Canada–Alaska (WC–A, 23 ± 4%) and East-central Canada–Minnesota (EC–M, 14 ± 3%). All tagged cranes returned to the same breeding affiliation used during the previous year with a median distance of 1.60 km (range: 0.08–7.7 km, n = 53) separating sites used in year 1 and year 2. Fall staging occurred

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

    PubMed Central

    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

  16. 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.

  17. 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.

  18. The Geographic Distribution of Boulder Halo Craters at Mid-to-High Latitudes on Mars

    NASA Technical Reports Server (NTRS)

    Rader, L. X.; Fassett, C. I.; Levy, J. S.; King, I. R.; Chaffey, P. M.; Wagoner, C. M.; Hanlon, A. E.; Watters, J. L.; Kreslavsky, M. A.; Holt, J. W.; Dyar, M. D.

    2017-01-01

    -producing materials from beneath the upper surface. Thus, the distribution and size of craters that result in boulders halos may provide in-sight into the thickness of the ice-rich surface layer in different locations. Note that this thickness is necessarily that of the ice-rich layer at the time of impact, not at present. This study is an initial survey of boulder halo crater locations in the 50deg to 80degN and 50deg to 80degS latitude bands on Mars.

  19. Updating the geographical distribution and frequency of Aedes albopictus in Brazil with remarks regarding its range in the Americas.

    PubMed

    Carvalho, Roberta Gomes; Lourenço-de-Oliveira, Ricardo; Braga, Ima Aparecida

    2014-09-01

    The geographical distribution of Aedes albopictus in Brazil was updated according to the data recorded across the country over the last eight years. Countrywide house indexes (HI) for Ae. albopictus in urban and suburban areas were described for the first time using a sample of Brazilian municipalities. This mosquito is currently present in at least 59% of the Brazilian municipalities and in 24 of the 27 federal units (i.e., 26 states and the Federal District). In 34 Brazilian municipalities, the HI values for Ae. albopictus were higher than those recorded for Ae. aegypti, reaching figures as high as HI = 7.72 in the Southeast Region. Remarks regarding the current range of this mosquito species in the Americas are also presented. Nineteen American countries are currently infested and few mainland American countries have not confirmed the occurrence of Ae. albopictus. The large distribution and high frequency of Ae. albopictus in the Americas may become a critical factor in the spread of arboviruses like chikungunya in the new world.

  20. 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.

  1. Updating the geographical distribution and frequency of Aedes albopictus in Brazil with remarks regarding its range in the Americas

    PubMed Central

    Carvalho, Roberta Gomes; Lourenço-de-Oliveira, Ricardo; Braga, Ima Aparecida

    2014-01-01

    The geographical distribution of Aedes albopictus in Brazil was updated according to the data recorded across the country over the last eight years. Countrywide house indexes (HI) for Ae. albopictus in urban and suburban areas were described for the first time using a sample of Brazilian municipalities. This mosquito is currently present in at least 59% of the Brazilian municipalities and in 24 of the 27 federal units (i.e., 26 states and the Federal District). In 34 Brazilian municipalities, the HI values for Ae. albopictus were higher than those recorded for Ae. aegypti, reaching figures as high as HI = 7.72 in the Southeast Region. Remarks regarding the current range of this mosquito species in the Americas are also presented. Nineteen American countries are currently infested and few mainland American countries have not confirmed the occurrence of Ae. albopictus. The large distribution and high frequency of Ae. albopictus in the Americas may become a critical factor in the spread of arboviruses like chikungunya in the new world. PMID:25317707

  2. Species diversity and geographic distribution of hard ticks (Acari: Ixodoidea: Ixodidae) infesting domestic ruminants, in Qazvin Province, Iran.

    PubMed

    Shemshad, Khadijeh; Rafinejad, Javad; Kamali, Karim; Piazak, Norayer; Sedaghat, Mohammad Mahdi; Shemshad, Masoomeh; Biglarian, Akbar; Nourolahi, Fathollah; Valad Beigi, Enshallah; Enayati, Ahmad Ali

    2012-01-01

    This report presents the results of the first faunistic study of hard ticks in Qazvin province of Iran. The primary objective was to determine the species diversity and geographic distribution of hard ticks that parasitize domestic ruminants. Information about the abiotic preferences of these species has been provided. A total of 286 cattle, 1,053 goats, and 2,050 sheep were examined in 13 villages in 28 flocks distributed throughout the studied areas. Total direct body collections of ticks were made from each domestic ruminant. A total of 228 Ixodid specimens belonging to nine species in three different genera were recorded in the areas, including Boophilus annulatus (Say, 1821), Hyalomma anatolicum Koch, 1844, Hyalomma asiaticum (Schulze and Schlettke, 1929), Hyalomma detritum Schulze, 1919, Hyalomma dromedarii Koch, 1844, Hyalomma marginatum Koch 1844, Hyalomma schulzei Olenev, 1931, Rhipicephalus bursa Canestrini and Fanz, 1878 and Rhipicephalus sanguineus (Latreille, 1806). The most abundant species on sheep was R. sanguineus (46.92%), while B. annulatus (6.6%) found only on cattle. A finding of great significance was that R. sanguineus, the main vector of babesiosis, is firmly established throughout the counties. A further objective of the study was to compare the abundance of the major tick species on domestic ruminants. This was carried out at 19 sampling sites. The highest number of ticks was collected in July-August during the hot season.

  3. AN ASSESSMENT OF HOST ASSOCIATIONS, GEOGRAPHIC DISTRIBUTIONS, AND GENETIC DIVERSITY OF AVIAN CHEWING LICE (INSECTA: PHTHIRAPTERA) FROM BENIN.

    PubMed

    Takano, Oona M; Mitchell, Preston S; Gustafsson, Daniel R; Adite, Alphonse; Voelker, Gary; Light, Jessica E

    2017-01-07

    Host associations of highly host-specific chewing lice (Insecta: Phthiraptera) across multiple avian species remains fairly undocumented in the West African country of Benin. Two hundred and seventeen bird specimens collected from multiple localities across Benin and housed at the Texas A&M University Biodiversity Research and Teaching Collections were examined for lice. Lice were identified and genetic data (mitochondrial COI and nuclear EF-1α genes) were obtained and phylogenetically analyzed. In total, we found 15 host associations, 7 of which were new to science. Genetically, most lice from Benin were unique and could represent new species. Based on host associations and unique genetic lineages, we estimate we discovered a minimum of 4 and possibly as many as 8 new chewing louse species. Given the lack of current data on chewing louse species distributions in Benin, this study adds to the knowledge of host associations, geographic distribution, and genetic variability of avian chewing louse species in West Africa.

  4. 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.

  5. Geographical distribution and oncogenic risk association of human papillomavirus type 58 E6 and E7 sequence variations

    PubMed Central

    Chan, Paul K.S.; Zhang, Chuqing; Park, Jong-Sup; Smith-McCune, Karen K.; Palefsky, Joel M.; Giovannelli, Lucia; Coutlée, Francois; Hibbitts, Samantha; Konno, Ryo; Settheetham-Ishida, Wannapa; Chu, Tang-Yuan; Ferrera, Annabelle; Picconi, María Alejandra; De Marco, Federico; Woo, Yin-Ling; Raiol, Tainá; Piña-Sánchez, Patricia; Bae, Jeong-Hoon; Wong, Martin C.S.; Chirenje, Mike Z.; Magure, Tsitsi; Moscicki, Anna-Barbara; Fiander, Alison N.; Capra, Giuseppina; Ki, Eun Young; Tan, Yi; Chen, Zigui; Burk, Robert D.; Chan, Martin C.W.; Cheung, Tak-Hong; Pim, David; Banks, Lawrence

    2014-01-01

    Human papillomavirus (HPV) 58 accounts for a notable proportion of cervical cancers in East Asia and parts of Latin America, but it is uncommon elsewhere. The reason for such ethnogeographical predilection is unknown. In our study, nucleotide sequences of E6 and E7 genes of 401 HPV58 isolates collected from 15 countries/cities across four continents were examined. Phylogenetic relationship, geographical distribution and risk association of nucleotide sequence variations were analyzed. We found that the E6 genes of HPV58 variants were more conserved than E7. Thus, E6 is a more appropriate target for type-specific detection, whereas E7 is more appropriate for strain differentiation. The frequency of sequence variation varied geographically. Africa had significantly more isolates with E6-367A (D86E) but significantly less isolates with E6-203G, -245G, -367C (prototype-like) than other regions (p ≤ 0.003). E7-632T, -760A (T20I, G63S) was more frequently found in Asia, and E7-793G (T74A) was more frequent in Africa (p < 0.001). Variants with T20I and G63S substitutions at E7 conferred a significantly higher risk for cervical intraepithelial neoplasia grade III and invasive cervical cancer compared to other HPV58 variants (odds ratio = 4.44, p = 0.007). In conclusion, T20I and/or G63S substitution(s) at E7 of HPV58 is/are associated with a higher risk for cervical neoplasia. These substitutions are more commonly found in Asia and the Americas, which may account for the higher disease attribution of HPV58 in these areas. PMID:23136059

  6. 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.

  7. Factors affecting distribution of airflow in a human tracheobronchial cast.

    PubMed

    Cohen, B S; Sussman, R G; Lippmann, M

    1993-09-01

    Air velocity was measured at end airways of hollow replicate casts of the human tracheobronchial tree in order to determine the flow distribution within casts extending to 3 mm diameter airways. Measurements were made by hot-wire anemometry for constant inspiratory flow rates of 7.5, 15, 30 and 60 L.min-1. Average flow distribution among the lung lobes was as follows: right upper, 18.5%; right middle, 9.2%; right lower, 32.3%; left upper, 15.7%; and left lower, 24.3%. An empirical model derived from the experimental flow distribution data demonstrated the effect of various morphometric parameters of the hollow cast on the distribution of airflow. Airway cross-sectional area, branching angle and total path-length were found to have the greatest influence. As the tracheal flow rate decreased from 60 to 7.5 L.min-1, the influence of branching angle was reduced, while total path-length became more influential. These results provide evidence for the transition of flow regimes within the TB tree within normal physiological flow ranges.

  8. Geographic and taxonomic distribution of a positive interaction: ant-tended homopterans indirectly benefit figs across southern Africa.

    PubMed

    Cushman, J Hall; Compton, Stephen G; Zachariades, Costas; Ware, Anthony B; Nefdt, Rory J C; Rashbrook, Vanessa K

    1998-09-01

    Although species pairs and assemblages often occur across geographic regions, ecologists know very little about the outcome of their interactions on such large spatial scales. Here, we assess the geographic distribution and taxonomic diversity of a positive interaction involving ant-tended homopterans and fig trees in the genus Ficus. Previous experimental studies at a few locations in South Africa indicated that Ficus sur indirectly benefited from the presence of a homopteran (Hilda patruelis) because it attracted ants (primarily Pheidole megacephala) that reduced the effects of both pre-dispersal ovule gallers and parasitoids of pollinating wasps. Based on this work, we evaluated three conditions that must be met in order to support the hypothesis that this indirect interaction involves many fig species and occurs throughout much of southern Africa and Madagascar. Data on 429 trees distributed among five countries indicated that 20 of 38 Ficus species, and 46% of all trees sampled, had ants on their figs. Members of the Sycomorus subgenus were significantly more likely to attract ants than those in the Urostigma subgenus, and ant-colonization levels on these species were significantly greater than for Urostigma species. On average, each ant-occupied F.sur tree had 37% of its fig crop colonized by ants, whereas the value was 24% for other Ficus species. H. patruelis was the most common source for attracting ants, although figs were also attacked by a range of other ant-tended homopterans. P. megacephala was significantly more common on figs than other ant species, being present on 58% of sampled trees. Ant densities commonly exceeded 4.5 per fig, which a field experiment indicated was sufficient to provide protection from ovule gallers and parasitoids of pollinators. Forty-nine percent of all colonized F. sur trees sampled had ant densities equal to or greater than 4.5 per fig, whereas this value was 23% for other Ficus species. We conclude that there is

  9. 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.

  10. Ticks: Geographic Distribution

    MedlinePlus

    ... areas on the Pacific Coast. Transmits: Tularemia and Rocky Mountain spotted fever . Comments: The highest risk of being bitten occurs ... dog tick ( Rhipicephalus sanguineus ) Where found: Worldwide. Transmits: Rocky Mountain spotted fever (in the southwestern U.S. and along the U.S.- ...

  11. Geographic Distribution of QCDs Around the Northern Plains Basins of Mars and the Relationship to Lowland Materials

    NASA Technical Reports Server (NTRS)

    Buczkowski, D. L.; Frey, H. V.; McGill, G. E.

    2005-01-01

    It has been suggested that quasicircular depressions (QCDs) without a structural representation in Viking and MOC visible imagery represent buried impact craters [1,2,3,4]. Topographic depressions will form over impact craters buried by a differentially compacting cover material because total cover thickness, and thus total compaction, is greater over the center of completely buried impact craters than their rims [5]. If this is the process by which QCDs form, then only areas of differentially compacting materials should have QCDs. Previous work has established that there is a relationship of surface relief to diameter for QCDs around the Utopia Basin [6]. The slope of the trend of this relationship varies depending on cover thickness, becoming steeper with decreasing thickness [7]. Comparing trendslopes of QCDs around different lowland basins might give us insight into the relative thickness of the cover material in these areas. We explore the geographic distribution of QCDs around the Utopia, Isidis and Acidalia basins and compare their location to geologic units and materials. We also compare evidence for relative thickness of cover material at the three basins.

  12. 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

  13. 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.

  14. Extent of mangrove nursery habitats determines the geographic distribution of a coral reef fish in a South-Pacific archipelago.

    PubMed

    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.

  15. Geographical distribution and risk assessment of persistent organic pollutants in golden threads (Nemipterus virgatus) from the northern South China Sea.

    PubMed

    Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

    2015-10-01

    Fish are often used as good bioindicators to monitor the occurrence of persistent organic pollutants (POPs) on different scales in recent years. Forty-five golden threads (Nemipterus virgatus) were collected from six sampling sites in the northern South China Sea (SCS) to investigate the geographical distribution of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs ranged from 1.3-36.0, 2.3-76.5, 8.3-228 ng/g lipid weight, respectively. The highest PBDEs and DDTs concentrations were found in golden threads from Shantou, owing to the intensive electronic waste recycling activities and rapid development of agriculture. Samples from Haikou had the highest levels of PCBs, probably due to the existence of many shipbuilding yards in the past years. The concentrations of PBDEs and PCBs were found in a decreasing trend from east to west and from north to south, while DDTs concentrations had no obvious trend in the distribution. PCBs were the most prevalent contaminants in Xiamen and Yangjiang, while DDTs were the dominant compounds at the other four sampling sites. Different profiles of POPs at each sampling site may attribute to different pollution sources in the northern SCS. Ratios of (DDD + DDE)/DDTs in golden threads suggested the probability of fresh input of DDT in the northern SCS. The estimated daily intakes of PBDEs, PCBs and DDTs were 0.030-0.069, 0.167-0.258 and 0.105-1.88 ng/kg/day, respectively, which were significantly lower than the acceptable daily intake, suggesting that consumption of golden threads from the northern SCS would not subject the residents in the coastal areas of SCS to significant health risk.

  16. 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 capital…

  17. 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…

  18. Muscidae (Insecta: Diptera) of Latin America and the Caribbean: geographic distribution and check-list by country.

    PubMed

    Löwenberg-Neto, Peter; De Carvalho, Claudio J B

    2013-01-01

    Here we provide a geographic database for the Muscidae (Insecta: Diptera) that are endemic to Latin America and the Caribbean and non-synanthropic. We summarize the geographic information provided by specimens from three entomological collections in Brazil (DZUP, MNRJ, and MZUEFS) as well as geographic information we compiled in the literature. The resulting 817 species were linked to their geographic records by country, state/province/department, locality, latitude and longitude, including source reference. When coordinates were not provided in specimens' labels, we used the locality information to search geographic coordinates in online gazetteers. We also separated the species by country for a country-species list. These data comprise 250 years of collections and taxonomic studies of Neotropical Muscidae and we expect that it provides a foundation and serves as guide for future studies of systematics and biogeography of the family.

  19. 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

  20. 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

  1. 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

    2015-04-05

    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.

  2. An exploratory analysis on how geographic, socioeconomic, and environmental drivers affect the diversity of livestock breeds worldwide.

    PubMed

    Leroy, G; Boettcher, P; Hoffmann, I; Mottet, A; Teillard, F; Baumung, R

    2016-12-01

    This study investigates the relationships between various environmental and geographic, demographic, and socioeconomic factors with the diversity of livestock breeds reported within countries across the world. Statistical analyses were performed considering the numbers of breeds reported by 158 countries for 4 livestock mammalian species (cattle, sheep, goats, and pigs). Organization for Economic Cooperation and Development (OECD) countries reported more breeds than non-OECD countries in general. Strong and positive correlations were found between agricultural area, human population size, species population size, and number of breeds per country. When considering regression models, the species population size was found as the most important explanatory factor for the number of breeds reported by countries in the 4 species. Diversity of production systems in the country had a significant association with the number of breeds reported for sheep, goats, and pigs. The number of ruminant breeds was positively associated with the size of agricultural area and the diversity of land cover in the country. While demographic and cultural importance of a given species is a major factor associated with the number of livestock breeds within countries, this diversity is also connected to the variability in environmental and production conditions.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial diversity of agricultural soils is well documented, but information on leafy green producing soils is limited. Our goal was to assess bacterial composition and diversity in leafy green producing soils using pyrosequencing, and to identify factors affecting bacterial community structures. C...

  4. Analysis of geological structure and anthropological factors affecting arsenic distribution in the Lahore aquifer, Pakistan

    NASA Astrophysics Data System (ADS)

    Muhammad, Akhtar Malik; Zhonghua, Tang; Sissou, Zakari; Mohamadi, Bahaa; Ehsan, Muhsan

    2016-11-01

    This study investigated the potential factors affecting arsenic concentration in the groundwater system of Lahore, Pakistan. The effects of several factors such as population density (PD), pumping rate (PR), impermeable land use (LU), surface elevation (SE), and water-table elevation (WL) on arsenic concentration were studied in 101 union councils of Lahore. Forty single and multi-factor models were established using geographic information system (GIS) techniques to develop an arsenic contamination map and to investigate the most effective combinations among factors. Additionally, statistical tests were used to evaluate arsenic concentration between classes of the same single factor. The arsenic concentration in the Lahore aquifer varied from 0.001 to 0.143 mg L-1. The highest arsenic concentrations were detected in the Walled City and the town of Shahdara. Among the 40 raster models, groundwater arsenic concentration showed the best matching frequency with single-factor models for PD (50.70 %) and SE (47 %). Thus, PD and SE were used to develop an arsenic distribution raster map, and they were also used to study the effect of aquifer depth on arsenic concentration. PD was found to have hidden latent variables such as PR and LU. The shallow aquifer depth was negatively correlated with arsenic concentration ( r = -0.23) and positively with PR ( r = 0.15). Therefore, when there was high PR in wells with smaller aquifer depth, the arsenic concentration was high. The existing water treatment and alternative water resources are good options, which should be developed to deal with Lahore wells contaminated with arsenic at high concentrations.

  5. 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.

  6. Haemopexin affects iron distribution and ferritin expression in mouse brain

    PubMed Central

    Morello, Noemi; Tonoli, Elisabetta; Logrand, Federica; Fiorito, Veronica; Fagoonee, Sharmila; Turco, Emilia; Silengo, Lorenzo; Vercelli, Alessandro; Altruda, Fiorella; Tolosano, Emanuela

    2009-01-01

    Haemopexin (Hx) is an acute phase plasma glycoprotein, mainly produced by the liver and released into plasma where it binds heme with high affinity and delivers it to the liver. This system provides protection against free heme-mediated oxidative stress, limits access by pathogens to heme and contributes to iron homeostasis by recycling heme iron. Hx protein has been found in the sciatic nerve, skeletal muscle, retina, brain and cerebrospinal fluid (CSF). Recently, a comparative proteomic analysis has shown an increase of Hx in CSF from patients with Alzheimer’s disease, thus suggesting its involvement in heme detoxification in brain. Here, we report that Hx is synthesised in brain by the ventricular ependymal cells. To verify whether Hx is involved in heme scavenging in brain, and consequently, in the control of iron level, iron deposits and ferritin expression were analysed in cerebral regions known for iron accumulation. We show a twofold increase in the number of iron-loaded oligodendrocytes in the basal ganglia and thalamus of Hx-null mice compared to wild-type controls. Interestingly, there was no increase in H- and L-ferritin expression in these regions. This condition is common to several human neurological disorders such as Alzheimer’s disease and Parkinson’s disease in which iron loading is not associated with an adequate increase in ferritin expression. However, a strong reduction in the number of ferritin-positive cells was observed in the cerebral cortex of Hx-null animals. Consistent with increased iron deposits and inadequate ferritin expression, malondialdehyde level and Cu–Zn superoxide dismutase-1 expression were higher in the brain of Hx-null mice than in that of wild-type controls. These data demonstrate that Hx plays an important role in controlling iron distribution within brain, thus suggesting its involvement in iron-related neurodegenerative diseases. PMID:19120692

  7. 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.

  8. Spatially Explicit Models to Investigate Geographic Patterns in the Distribution of Forensic STRs: Application to the North-Eastern Mediterranean

    PubMed Central

    Messina, Francesco; Finocchio, Andrea; Akar, Nejat; Loutradis, Aphrodite; Michalodimitrakis, Emmanuel I.; Brdicka, Radim; Jodice, Carla

    2016-01-01

    Human forensic STRs used for individual identification have been reported to have little power for inter-population analyses. Several methods have been developed which incorporate information on the spatial distribution of individuals to arrive at a description of the arrangement of diversity. We genotyped at 16 forensic STRs a large population sample obtained from many locations in Italy, Greece and Turkey, i.e. three countries crucial to the understanding of discontinuities at the European/Asian junction and the genetic legacy of ancient migrations, but seldom represented together in previous studies. Using spatial PCA on the full dataset, we detected patterns of population affinities in the area. Additionally, we devised objective criteria to reduce the overall complexity into reduced datasets. Independent spatially explicit methods applied to these latter datasets converged in showing that the extraction of information on long- to medium-range geographical trends and structuring from the overall diversity is possible. All analyses returned the picture of a background clinal variation, with regional discontinuities captured by each of the reduced datasets. Several aspects of our results are confirmed on external STR datasets and replicate those of genome-wide SNP typings. High levels of gene flow were inferred within the main continental areas by coalescent simulations. These results are promising from a microevolutionary perspective, in view of the fast pace at which forensic data are being accumulated for many locales. It is foreseeable that this will allow the exploitation of an invaluable genotypic resource, assembled for other (forensic) purposes, to clarify important aspects in the formation of local gene pools. PMID:27898725

  9. 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...

  10. Prasinovirus distribution in the Northwest Mediterranean Sea is affected by the environment and particularly by phosphate availability.

    PubMed

    Clerissi, Camille; Grimsley, Nigel; Subirana, Lucie; Maria, Eric; Oriol, Louise; Ogata, Hiroyuki; Moreau, Hervé; Desdevises, Yves

    2014-10-01

    Numerous seawater lagoons punctuate the southern coastline of France. Exchanges of seawater between these lagoons and the open sea are limited by narrow channels connecting them. Lagoon salinities vary according to evaporation and to the volume of freshwater arriving from influent streams, whose nutrients also promote the growth of algae. We compared Prasinovirus communities, whose replication is supported by microscopic green algae, in four lagoons and at a coastal sampling site. Using high-throughput sequencing of DNA from a giant virus-specific marker gene, we show that the environmental conditions significantly affect the types of detectable viruses across samples. In spatial comparisons between 5 different sampling sites, higher levels of phosphates, nitrates, nitrites, ammonium and silicates tend to increase viral community richness independently of geographical distances between the sampling sites. Finally, comparisons of Prasinovirus communities at 2 sampling sites over a period of 10 months highlighted seasonal effects and the preponderant nature of phosphate concentrations in constraining viral distribution.

  11. The myxozoan fauna of Fundulus diaphanus (Cyprinodontidae) from freshwater localities in eastern North America: prevalence, community structure, and geographic distribution.

    PubMed

    Cone, David K; Marcogliese, David J; Barse, Ann M; Burt, Michael D B

    2006-02-01

    Membership and richness of infracommunities and component communities of myxozoan fauna of the banded killifish (Fundulus diaphanus) from freshwater localities in Ontario, Quebec, New York State, New Brunswick, Nova Scotia, and Maryland were studied. Five species of parasites were found: Myxobolus diaphanus (Fantham, Porter, and Richardson, 1940) (connective tissue throughout the body and head), Myxobolus funduli (Kudo, 1918) (interlamellar), Myxobolus neurophilus (Guilford, 1963) (optic tectum of the brain), Myxobolus sp. (connective tissue, typically adjacent to vertebrae), and Sphaerospora sp. (kidney tubules). The most abundant species locally and regionally was M. diaphanus, occurring at prevalences of 14.2 to 93.3% at 6 of 9 localities. Myxobolus funduli and Myxobolus sp. were at 3 and 2 localities respectively, while M. neurophilus and Sphaerospora each occurred at single localities. Four of the 5 myxozoans appear to be specific to fundulids, the exception being M. neurophilus, which is typically a parasite of Perca flavescens. Mean infracommunity richness was 0-1.2. Component community richness was 0-3 species. The fauna is similar in composition to that described from the spottail shiner (Notropis hudsonius) in the Great Lakes in being dominated by histozoic myxobolids and in having maximum prevalence at any single locality correlate positively with geographical distribution. Moreover, mean infracommunity richness was correlated with percentage of hosts infected with any species at a locality, and maximum infracommunity richness was correlated with component community richness. Probably because fewer species of myxozoans of fundulids occur in the regional pool, myxozoan communities encountered in the present study are generally less rich than those described from N. hudsonius. It appears that dispersal of relatively resilient myxospores through such a mechanism as piscivory effectively distributes these parasites over the landscape, while the more delicate

  12. Geographical information system and access to HIV testing, treatment and prevention of mother-to-child transmission in conflict affected Northern Uganda

    PubMed Central

    Chamla, Dick D; Olu, Olushayo; Wanyana, Jennifer; Natseri, Nasan; Mukooyo, Eddie; Okware, Sam; Alisalad, Abdikamal; George, Melville

    2007-01-01

    Objectives Using Geographical Information System (GIS) as a tool to determine access to and gaps in providing HIV counselling and testing (VCT), treatment (ART) and mother-to-child transmission (PMTCT) services in conflict affected northern Uganda. Methods Cross-sectional data on availability and utilization, and geo-coordinates of health facilities providing VCT, PMTCT, and ART were collected in order to determine access. ArcView software produced maps showing locations of facilities and Internally Displaced Population(IDP) camps. Findings There were 167 health facilities located inside and outside 132 IDP camps with VCT, PMTCT and ART services provided in 32 (19.2%), 15 (9%) and 10 (6%) facilities respectively. There was uneven availability and utilization of services and resources among districts, camps and health facilities. Inadequate staff and stock-out of essential commodities were found in lower health facility levels. Provision of VCT was 100% of the HSSP II target at health centres IV and hospitals but 28% at HC III. For PMTCT and ART, only 42.9% and 20% of the respective targets were reached at the health centres IV. Conclusion Access to VCT, PMTCT and ART services was geographically limited due to inadequacy and heterogeneous dispersion of these services among districts and camps. GIS mapping can be effective in identifying service delivery gaps and presenting complex data into simplistic results hence can be recommended in need assessments in conflict settings. PMID:18053189

  13. The geographical distribution of the potential for seed germination and seedling establishment of Pinus densiflora in Japan as influenced by soil and air temperatures

    NASA Astrophysics Data System (ADS)

    Kashiwagi, Y.

    1991-12-01

    The geographical distribution of Pinus densiflora forests in Japan was examined in relation to the seed germination and seedling establishment information obtained from laboratory experiments, field observations and field experiments. The laboratory experiments indicated that seed germination can occur in all areas of Japan because effective cumulative soil temperatures reaches to 75 °C · day everywhere. However, the field observations and field experiments suggested that seedling establishment is impossible in the northern, eastern and central parts of Hokkaido because the effective cumulative air temperature at a height of 6 cm over bare ground is less than 2 000 °C · day. These results agree approximately with the actual geographical distribution of P. densiflora forest, which can not be found under natural circumstances in these areas.

  14. 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

  15. Malacological survey and geographical distribution of vector snails for schistosomiasis within informal settlements of Kisumu City, western Kenya

    PubMed Central

    2011-01-01

    Background Although schistosomiasis is generally considered a rural phenomenon, infections have been reported within urban settings. Based on observations of high prevalence of Schistosoma mansoni infection in schools within the informal settlements of Kisumu City, a follow-up malacological survey incorporating 81 sites within 6 informal settlements of the City was conducted to determine the presence of intermediate host snails and ascertain whether active transmission was occurring within these areas. Methods Surveyed sites were mapped using a geographical information system. Cercaria shedding was determined from snails and species of snails identified based on shell morphology. Vegetation cover and presence of algal mass at the sites was recorded, and the physico-chemical characteristics of the water including pH and temperature were determined using a pH meter with a glass electrode and a temperature probe. Results Out of 1,059 snails collected, 407 (38.4%) were putatively identified as Biomphalaria sudanica, 425 (40.1%) as Biomphalaria pfeifferi and 227 (21.5%) as Bulinus globosus. The spatial distribution of snails was clustered, with few sites accounting for most of the snails. The highest snail abundance was recorded in Nyamasaria (543 snails) followed by Nyalenda B (313 snails). As expected, the mean snail abundance was higher along the lakeshore (18 ± 12 snails) compared to inland sites (dams, rivers and springs) (11 ± 32 snails) (F1, 79 = 38.8, P < 0.0001). Overall, 19 (1.8%) of the snails collected shed schistosome cercariae. Interestingly, the proportion of infected Biomphalaria snails was higher in the inland (2.7%) compared to the lakeshore sites (0.3%) (P = 0.0109). B. sudanica was more abundant in sites along the lakeshore whereas B. pfeifferi and B. globosus were more abundant in the inland sites. Biomphalaria and Bulinus snails were found at 16 and 11 out of the 56 inland sites, respectively. Conclusions The high abundance of Biomphalaria and

  16. 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

  17. 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

    Freeman, Benjamin G; Mason, Nicholas A

    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.

  18. 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

  19. How the Assumed Size Distribution of Dust Minerals Affects the Predicted Ice Forming Nuclei

    NASA Astrophysics Data System (ADS)

    Perlwitz, J. P.; Fridlind, A. M.; Pérez García-Pando, C.; Miller, R. L.; Knopf, D. A.

    2015-12-01

    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 μm. 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 μm 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

  20. 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.

  1. 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

  2. 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.

  3. 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...

  4. Geographical DNA

    NASA Astrophysics Data System (ADS)

    Wojtanowicz, Paweł

    2012-01-01

    The article shows the results of a study undertaken to search for a model illustrating the development of geographical thought. The created model, formulated with a triad that defines geography: human being-space-time, displays levels merging geographical sciences. These joining elements created by geographers, more or less consciously cooperating with the representatives of other sciences, seem to be the essence of the unity of the continuously spreading study range of geography.

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

    PubMed

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

    2013-12-01

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

  6. 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.

  7. 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.

  8. 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

  9. Geographic distribution and regional impacts of Oxyops vitiosa (Coleoptera: Curculionidae) and Boreioglycaspis melaleucae (Hemiptera: Psyllidae), biological control agents of the invasive tree Melaleuca quinquenervia.

    PubMed

    Balentine, K M; Pratt, P D; Dray, F A; Rayamajhi, M B; Center, T D

    2009-08-01

    The invasive tree Melaleuca quinquenervia (Cav.) Blake is widely distributed throughout peninsular Florida and poses a significant threat to species diversity in the wetland systems of the Everglades. Mitigation of this threat includes the areawide release campaign of the biological control agents Oxyops vitiosa Pascoe and Boreioglycaspis melaleucae Moore. We summarize the results of this release effort and quantify the resulting geographic distribution of the herbivores as well as their regional impact on the target weed. A combined total of 3.3 million individual Melaleuca biological control agents have been redistributed to 407 locations and among 15 Florida counties. Surveys of the invaded area indicate that the geographic distribution of O. vitiosa encompasses 71% of the Melaleuca infestation. Although released 5 yr later, the distribution of B. melaleuca is slightly greater than its predecessor, with a range including 78% of the sampled Melaleuca stands. Melaleuca stands outside both biological control agents' distributions occurred primarily in the northern extremes of the tree's range. Strong positive association between herbivore species was observed, with the same density of both species occurring in 162 stands and no evidence of interspecific competition. Soil type also influenced the incidence of biological control agents and the distribution of their impacts. The odds of encountering O. vitiosa or B. melaleucae in cells dominated by sandy soils were 2.2 and 2.9 times more likely than those predominated by organically rich soils. As a result, a greater level of damage from both herbivores was observed for stands growing on sandy versus organic-rich soils.

  10. Determining the factors affecting the distribution of Muscari latifolium, an endemic plant of Turkey, and a mapping species distribution model.

    PubMed

    Yilmaz, Hatice; Yilmaz, Osman Yalçın; Akyüz, Yaşar Feyza

    2017-02-01

    Species distribution modeling was used to determine factors among the large predictor candidate data set that affect the distribution of Muscari latifolium, an endemic bulbous plant species of Turkey, to quantify the relative importance of each factor and make a potential spatial distribution map of M. latifolium. Models were built using the Boosted Regression Trees method based on 35 presence and 70 absence records obtained through field sampling in the Gönen Dam watershed area of the Kazdağı Mountains in West Anatolia. Large candidate variables of monthly and seasonal climate, fine-scale land surface, and geologic and biotic variables were simplified using a BRT simplifying procedure. Analyses performed on these resources, direct and indirect variables showed that there were 14 main factors that influence the species' distribution. Five of the 14 most important variables influencing the distribution of the species are bedrock type, Quercus cerris density, precipitation during the wettest month, Pinus nigra density, and northness. These variables account for approximately 60% of the relative importance for determining the distribution of the species. Prediction performance was assessed by 10 random subsample data sets and gave a maximum the area under a receiver operating characteristic curve (AUC) value of 0.93 and an average AUC value of 0.8. This study provides a significant contribution to the knowledge of the habitat requirements and ecological characteristics of this species. The distribution of this species is explained by a combination of biotic and abiotic factors. Hence, using biotic interaction and fine-scale land surface variables in species distribution models improved the accuracy and precision of the model. The knowledge of the relationships between distribution patterns and environmental factors and biotic interaction of M. latifolium can help develop a management and conservation strategy for this species.

  11. Is the geographic distribution of nesting in the Kemp's ridley turtle shaped by the migratory needs of offspring?

    PubMed

    Putman, Nathan F; Shay, Thomas J; Lohmann, Kenneth J

    2010-09-01

    Across the geographic area that a species uses for reproduction, the density of breeding individuals is typically highest in locations where ecological factors promote reproductive success. For migratory animals, fitness depends, in part, on producing offspring that migrate successfully to habitats suitable for the next life-history stage. Thus, natural selection might favor reproduction in locations with conditions that facilitate the migration of offspring. To investigate this concept, we studied the Kemp's ridley sea turtle (Lepidochelys kempii) to determine whether coastal areas with the highest levels of nesting have particularly favorable conditions for hatchling migration. We modeled the passive drift of young Kemp's ridley turtles from seven nesting regions within the Gulf of Mexico to foraging grounds using the particle-tracking program ICHTHYOP and surface-current output from HYCOM (HYbrid Coordinate Ocean Model). Results revealed that geographic regions with conditions that facilitate successful migration to foraging grounds typically have higher abundance of nests than do regions where oceanographic conditions are less favorable and successful migration is difficult for hatchlings. Thus, our findings are consistent with the hypothesis that, for the Kemp's ridley turtle and perhaps for other migrants, patterns of abundance across the breeding range are shaped in part by conditions that promote or impede the successful migration of offspring.

  12. 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.

  13. 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

  14. Geographic relations of landslide distribution and assessment of landslide hazards in the Blanco, Cibuco, and Coamo basins, Puerto Rico

    USGS Publications Warehouse

    Larsen, M.C.; Torres-Sanchez, A. J.

    1996-01-01

    Landslide occurrence is common in mountainous areas of Puerto Rico where mean annual rainfall and the frequency of intense storms are high and hillslopes are steep. Each year, landslides cause extensive damage to property and occasionally result in loss of life. Landslide maps developed from 1:20,000 scale aerial photographs in combination with a computerized geographic information system were used to evaluate the landslide potential in the Blanco, Cibuco, and Coamo Basins of Puerto Rico. These basins, ranging in surface area from 276 to 350 square kilometers, are described in this report. The basins represent a broad range of the climatologic, geographic, and geologic conditions that occur in Puerto Rico. In addition, a variety of landslide types were documented. Rainfall-triggered debris flows, shallow soil slips, and slumps were most abundant. The most important temporal control on landslide occurrence in Puerto Rico is storm rainfall. Forty-one storms triggered widespread landsliding about 1 to 2 times per year during the last three decades. These storms were frequently of 1 to 2 days duration in which, on average, several hundred millimeters of rainfall triggered tens to hundreds of landslides in the central mountains. Most of these storms were tropical disturbances that occurred during the hurricane season of June through November. Land use and the topographic characteristics of hillslope angle, elevation, and aspect are the most important spatial controls governing landslide frequency. Hillslopes in the study area that have been anthropogenically modified, exceed 12 degrees in gradient and about 350 meters in elevation, and face the east-northeast are most prone to landsliding. Bedrock geology and soil order seem less important in the determination of landslide frequency, at least when considered at a generalized level. A rainfall accumulation-duration relation for the triggering of numerous landslides throughout the central mountains, and a set of

  15. 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.

  16. 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 ...

  17. 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

  18. 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.

  19. A review of the current geographic distribution of and debate surrounding electronic cigarette clean air regulations in the United States.

    PubMed

    Kadowaki, Joy; Vuolo, Mike; Kelly, Brian C

    2015-01-01

    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.

  20. 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

  1. Invasive Tipula (Diptera: Tipulidae) in turfgrass of the northeast United States: geographic distribution and local incidence three years after detection.

    PubMed

    Peck, Daniel C; Olmstead, Daniel

    2009-04-01

    Two species of invasive crane flies are damaging pests of turfgrass in the Great Lakes region after their inadvertent introduction and establishment. In New York, where Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae) were first detected in 2004, baseline data on the extent of establishment is needed to monitor range expansion, make predictions about pest status, and guide management efforts. The incidence of both species was therefore addressed at two spatial scales to ascertain how widespread they were across the state and across sites of recent local establishment. Based on divergent natural history, T. oleracea was predicted to be more widespread both geographically and locally than T. paludosa. To delimit the current area of occurrence, surveys were conducted from 2004 to 2006. T. paludosa was detected in four counties and T. oleracea in 12 counties. In western New York, T. oleracea was established in more than a six-fold greater area than T. paludosa. T. oleracea was additionally detected on Long Island, shown to be a geographically disjunct area of establishment. To measure local incidence, putting greens and tee boxes were scouted on golf courses. Contrary to predictions, 56-97 and 22-56% of those surfaces were already infested by T. paludosa and T. oleracea, respectively, within one or two seasons after initial detection. Because damage thresholds are relatively high, scouting for the insect, rather than its injury, will promote earlier detection. Given the impact of invasive Tipula across diverse turf habitats, continued range expansion will have serious repercussions for regional turfgrass management.

  2. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... minority interests. 1.332-5 Section 1.332-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance of a plan of complete liquidation, the gain or loss of minority shareholders shall be...

  3. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... minority interests. 1.332-5 Section 1.332-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance of a plan of complete liquidation, the gain or loss of minority shareholders shall be...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... minority interests. 1.332-5 Section 1.332-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance of a plan of complete liquidation, the gain or loss of minority shareholders shall be...

  5. Geographic Tongue

    MedlinePlus

    ... cases, most often related to eating hot, spicy, salty or acidic foods Many people with geographic tongue ... sensitive oral tissues, including: Hot, spicy, acidic or salty foods Tobacco products Toothpaste that contains tartar-control ...

  6. Prevalence of factor V Leiden and prothrombin G20210A mutation in a large French population selected for nonthrombotic history: geographical and age distribution.

    PubMed

    Mazoyer, Elisabeth; Ripoll, Laurent; Gueguen, René; Tiret, Laurence; Collet, Jean-Philippe; dit Sollier, Claire Bal; Roussi, Jacqueline; Drouet, Ludovic

    2009-10-01

    Among inherited risk factors for venous thrombosis, the most common are the FV-G1691A and FII-G20210A polymorphisms. The FV-G1691A polymorphism is preferentially observed in Europe, with differences between European countries. The FII-G20210A polymorphism is observed all over the world. The study was designed to compare the prevalence of the FV-G1691A and FII-G20210A polymorphisms in a large French population of unrelated individuals with no thrombotic disease history and to determine the age and geographical distributions. Over a period of 18 months, 6154 individuals were included throughout France and FV-G1691A and FII-G20210A polymorphisms were determined. The FV-G1691A prevalence was 3.84% (95% confidence interval 3.35-4.33) and the FII-G20210A prevalence was 3.07% (95% CI 2.63-3.51). A north-east/south-west gradient was observed in the FV-G1691A geographical distribution. No difference was observed in the geographical distribution of FII-G20210A polymorphism nor in the age distribution of the two polymorphisms. The prevalence of the two polymorphisms was similar whatever the blood group (O or non-O). Plasma D-dimers were significantly higher in healthy individuals with FV-G1691A but not in individuals with FII-G20210A. Thirty percent of variation in plasma prothrombin level was explained by environmental factors (serum cholesterol, age, oral contraception, hormonal replacement therapy, body mass index, sex) and genetic factors (FII-G20210A). As expected, individuals with FII-G20210A displayed higher plasma prothrombin level compared with individuals with wild type. However, this was not associated with a modification of the fibrin clot elastic modulus. This study shows a differential distribution of the two polymorphisms among the French territory. These polymorphisms confer a very mild hypercoagulable state as shown by the limited increased in basal D-dimers in mutated FV-G1691A populations and only a trend that does not reach statistical significance for FII

  7. Redescription and Geographical Distribution of the Endangered Fish Ossubtus xinguense Jégu 1992 (Characiformes, Serrasalmidae) with Comments on Conservation of the Rheophilic Fauna of the Xingu River

    PubMed Central

    Andrade, Marcelo C.; Sousa, Leandro M.; Ota, Rafaela P.; Jégu, Michel; Giarrizzo, Tommaso

    2016-01-01

    The monotypic species Ossubtus xinguense was originally described based on scarce material putatively divided into juveniles and adults. Ossubtus xinguense has a restricted distribution and was previously known only from a few rapids downstream of the city of Altamira, in the Volta Grande stretch of the Middle Xingu River. Until recently, the species was rare in museums because its habitat (large rapids) is difficult to sample. Large-scale collecting efforts targeting rapids throughout the Xingu River basin have yielded an abundance of new material. Based on an analysis of the type series and freshly preserved specimens, we redescribe O. xinguense and provide detailed osteological descriptions along with comments about its relationships within Serrasalmidae. Furthermore, we expand the geographical distribution of the species and discuss its conservation status. PMID:27662358

  8. Redescription and Geographical Distribution of the Endangered Fish Ossubtus xinguense Jégu 1992 (Characiformes, Serrasalmidae) with Comments on Conservation of the Rheophilic Fauna of the Xingu River.

    PubMed

    Andrade, Marcelo C; Sousa, Leandro M; Ota, Rafaela P; Jégu, Michel; Giarrizzo, Tommaso

    The monotypic species Ossubtus xinguense was originally described based on scarce material putatively divided into juveniles and adults. Ossubtus xinguense has a restricted distribution and was previously known only from a few rapids downstream of the city of Altamira, in the Volta Grande stretch of the Middle Xingu River. Until recently, the species was rare in museums because its habitat (large rapids) is difficult to sample. Large-scale collecting efforts targeting rapids throughout the Xingu River basin have yielded an abundance of new material. Based on an analysis of the type series and freshly preserved specimens, we redescribe O. xinguense and provide detailed osteological descriptions along with comments about its relationships within Serrasalmidae. Furthermore, we expand the geographical distribution of the species and discuss its conservation status.

  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. 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

  11. 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.

  12. 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

  13. Potential effects of climate change on geographic distribution of the Tertiary relict tree species Davidia involucrata in China

    PubMed Central

    Tang, Cindy Q.; Dong, Yi-Fei; Herrando-Moraira, Sonia; Matsui, Tetsuya; Ohashi, Haruka; He, Long-Yuan; Nakao, Katsuhiro; Tanaka, Nobuyuki; Tomita, Mizuki; Li, Xiao-Shuang; Yan, Hai-Zhong; Peng, Ming-Chun; Hu, Jun; Yang, Ruo-Han; Li, Wang-Jun; Yan, Kai; Hou, Xiuli; Zhang, Zhi-Ying; López-Pujol, Jordi

    2017-01-01

    This study, using species distribution modeling (involving a new approach that allows for uncertainty), predicts the distribution of climatically suitable areas prevailing during the mid-Holocene, the Last Glacial Maximum (LGM), and at present, and estimates the potential formation of new habitats in 2070 of the endangered and rare Tertiary relict tree Davidia involucrata Baill. The results regarding the mid-Holocene and the LGM demonstrate that south-central and southwestern China have been long-term stable refugia, and that the current distribution is limited to the prehistoric refugia. Given future distribution under six possible climate scenarios, only some parts of the current range of D. involucrata in the mid-high mountains of south-central and southwestern China would be maintained, while some shift west into higher mountains would occur. Our results show that the predicted suitable area offering high probability (0.5‒1) accounts for an average of only 29.2% among the models predicted for the future (2070), making D. involucrata highly vulnerable. We assess and propose priority protected areas in light of climate change. The information provided will also be relevant in planning conservation of other paleoendemic species having ecological traits and distribution ranges comparable to those of D. involucrata. PMID:28272437

  14. Potential effects of climate change on geographic distribution of the Tertiary relict tree species Davidia involucrata in China.

    PubMed

    Tang, Cindy Q; Dong, Yi-Fei; Herrando-Moraira, Sonia; Matsui, Tetsuya; Ohashi, Haruka; He, Long-Yuan; Nakao, Katsuhiro; Tanaka, Nobuyuki; Tomita, Mizuki; Li, Xiao-Shuang; Yan, Hai-Zhong; Peng, Ming-Chun; Hu, Jun; Yang, Ruo-Han; Li, Wang-Jun; Yan, Kai; Hou, Xiuli; Zhang, Zhi-Ying; López-Pujol, Jordi

    2017-03-08

    This study, using species distribution modeling (involving a new approach that allows for uncertainty), predicts the distribution of climatically suitable areas prevailing during the mid-Holocene, the Last Glacial Maximum (LGM), and at present, and estimates the potential formation of new habitats in 2070 of the endangered and rare Tertiary relict tree Davidia involucrata Baill. The results regarding the mid-Holocene and the LGM demonstrate that south-central and southwestern China have been long-term stable refugia, and that the current distribution is limited to the prehistoric refugia. Given future distribution under six possible climate scenarios, only some parts of the current range of D. involucrata in the mid-high mountains of south-central and southwestern China would be maintained, while some shift west into higher mountains would occur. Our results show that the predicted suitable area offering high probability (0.5‒1) accounts for an average of only 29.2% among the models predicted for the future (2070), making D. involucrata highly vulnerable. We assess and propose priority protected areas in light of climate change. The information provided will also be relevant in planning conservation of other paleoendemic species having ecological traits and distribution ranges comparable to those of D. involucrata.

  15. Geographic distribution of an extinct equid (Equus hydruntinus: Mammalia, Equidae) revealed by morphological and genetical analyses of fossils.

    PubMed

    Orlando, Ludovic; Mashkour, Marjan; Burke, Ariane; Douady, Christophe J; Eisenmann, Véra; Hänni, Catherine

    2006-07-01

    Equus hydruntinus inhabited Europe and the Middle East for more than 300 000 years. For a long time, palaeontological data failed to place E. hydruntinus into the equid phylogenetic tree, confronted with the fact that it shares primitive Equus characters with both zebras and asses, and derived characters with asses and hemiones. However, the study of a recently discovered skull points to a relationship with hemiones. Extraction of DNA from ancient samples from Crimea (E. hydruntinus) and Iran (E. cf. hydruntinus) yielded 134-288 bp of the mtDNA control region and 143 bp of the cytochrome b gene. This DNA analysis supports the proximity of E. hydruntinus and Equus hemionus suggested by skull and limb bone analyses, and rejects proximity to either Equus burchelli or the asses suggested by tooth morphology. Dental morphology may thus be of poor taxonomical value if used alone for establishing equid phylogenetic relationships. Furthermore, the small genetic distance between E. cf. hydruntinus of Iran and the classical E. hydruntinus of Crimea suggests that both samples belong to the same species. Accordingly, the geographic range of E. hydruntinus -- until now believed to be restricted to Europe, Israel, and Turkey -- can be extended towards East as far as Iran.

  16. 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.

  17. [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.

  18. Seroprevalence and geographic distribution of Dirofilaria immitis and tick-borne infections (Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Ehrlichia canis) in dogs from Romania.

    PubMed

    Mircean, Viorica; Dumitrache, Mirabela Oana; Györke, Adriana; Pantchev, Nikola; Jodies, Robert; Mihalca, Andrei Daniel; Cozma, Vasile

    2012-07-01

    Tick-borne diseases are of great concern worldwide. Despite this, in Romania there is only limited information regarding the prevalence of vector-borne pathogens in dogs. In all, 1146 serum samples were tested by SNAP(®) 4Dx(®) (IDEXX Laboratories, Inc., Westbrook, ME) for Anaplasma phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis antibodies, and for Dirofilaria immitis antigen. The correlation between positive cases and their geographic distribution, as well as potential risk factors (age, sex, breed, type of dog, habitat, and prophylactic treatments) were evaluated. Overall, 129 dogs (11.3%) were serologically-positive to one or more of the tested pathogens. The seroprevalence for the four infectious agents were: A. phagocytophilum 5.5% (63/1146), D. immitis 3.3% (38/1146), E. canis 2.1% (24/1146), and B. burgdorferi 0.5% (6/1146). Co-infection with E. canis and A. phagocytophilum was registered in 2 dogs (0.2%). The geographical distribution of the seropositive cases suggests clustered foci in southern regions and in the western part of the country for D. immitis, and in the southeastern region (Constanţa County) for E. canis. A. phagocytophilum and B. burgdorferi showed a homogenous distribution, with a tendency for Lyme-positive samples to concentrate in central Romania. For D. immitis, A. phagocytophilum, and E. canis, administering prophylactic treatments was a risk factor associated with infection. Another associated risk factor was the type of dog (stray dogs were at risk being positive for D. immitis, shelter dogs for E. canis, and hunting dogs for B. burgdorferi). The prevalence of D. immitis was significantly higher in males and in dogs older than 2 years. This survey represents the first data detailing A. phagocytophilum and E. canis seroprevalence in Romanian dogs, and the most comprehensive epidemiological study on vector-borne infections in dogs from this country.

  19. 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...

  20. 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...

  1. 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

    2014-12-12

    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

  2. Geographic distribution of the muscle-dwelling nematode Parelaphostrongylus odocoilei in North America, using molecular identification of first-stage larvae.

    PubMed

    Jenkins, Emily J; Appleyard, Greg D; Hoberg, Eric P; Rosenthal, Benjamin M; Kutz, Susan J; Veitch, Alasdair M; Schwantje, Helen M; Elkin, Brett T; Polley, Lydden

    2005-06-01

    Molecular identification of dorsal-spined larvae (DSL) from fecal samples indicates that the protostrongylid parasite Parelaphostrongylus odocoilei occupies a broader geographic range in western North America than has been previously reported. We analyzed 2,124 fecal samples at 29 locations from thinhorn sheep (Ovis dalli dalli and O. d. stonei), bighorn sheep (Ovis canadensis canadensis and O. c. californiana), mountain goats (Oreamnos americanus), woodland caribou (Rangifer tarandus caribou), mule deer (Odocoileus hemionus hemionus), and black-tailed deer (O. h. columbianus). The DSL were recovered from populations of thinhorn sheep south, but not north, of the Arctic Circle, and they were not recovered from any of the bighorn sheep populations that we examined. In total, DSL were recovered from 20 locations in the United States and Canada (Alaska, Yukon Territory, Northwest Territories, British Columbia, Alberta, and California). The DSL were identified as P. odocoilei by comparing sequences of the second internal transcribed spacer (ITS2) region of ribosomal RNA among 9 protostrongylid species validated by adult comparative morphology. The ITS2 sequences were markedly different between Parelaphostrongylus and other protostrongylid genera. Smaller fixed differences served as diagnostic markers for the 3 species of Parelaphostrongylus. The ITS2 sequences (n = 60) of P. odocoilei were strongly conserved across its broad geographic range from California to Alaska. Polymorphism at 5 nucleotide positions was consistent with multiple copies of the ITS2 within individual specimens of P. odocoilei. This work combines extensive fecal surveys, comparative morphology, and molecular diagnostic techniques to describe comprehensively the host associations and geographic distribution of a parasitic helminth.

  3. Allelic Diversity and Geographical Distribution of the Gene Encoding Plasmodium falciparum Merozoite Surface Protein-3 in Thailand.

    PubMed

    Sawaswong, Vorthon; Simpalipan, Phumin; Siripoon, Napaporn; Harnyuttanakorn, Pongchai; Pattaradilokrat, Sittiporn

    2015-04-01

    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.

  4. Molecular epidemiology of malaria in Cameroon. XXII. Geographic mapping and distribution of Plasmodium falciparum dihydrofolate reductase (dhfr) mutant alleles.

    PubMed

    Tahar, Rachida; Basco, Leonardo K

    2006-09-01

    Sulfadoxine-pyrimethamine (SP) is still a useful drug to combat chloroquine-resistant Plasmodium falciparum malaria in Cameroon. Because of several disadvantages of the in vivo test and in vitro drug sensitivity assays, molecular assays are an alternative laboratory tool to monitor the evolution of antifolate resistance, especially over the entire country that is characterized by several epidemiologic strata and malaria transmission patterns. In this study, 1,430 blood samples from either symptomatic children or asymptomatic carriers were collected from 14 sites throughout the country between 1999 and 2003 for the analysis of dihydrofolate reductase (dhfr) sequence. Of 1,368 samples (95.7%) that were successfully amplified, 1,180 were analyzed by direct sequencing of the polymerase chain reaction product, and 188 were analyzed by restriction enzymes. The prevalences of the wild-type, single Asn-108 mutation, double Arg-59/Asn-108 mutations, double Ile-51/Asn-108 mutations, triple Ile-51/Arg-59/Asn-108 mutations, and mixed alleles were 20.8%, 2.8%, 5.7%, 0.8%, 62.2%, and 7.6%, respectively. The proportions of triple dhfr mutations were > 60% at all study sites, with the exception of the eastern province (42% triple mutants in Bertoua in 1999) and the northern provinces (11-35% triple mutants in Ngaoundere, Garoua, and Maroua). In these two provinces, the proportion of mutant parasites increased significantly (P < 0.05) over the period of 2-4 years. Furthermore, there was a higher proportion (P < 0.05) of wild-type parasites in the northern provinces, compared with the rest of the country. The geographic mapping of molecular markers offers a novel tool for monitoring the epidemiology of drug-resistant malaria.

  5. Atmospheric deposition of polycyclic aromatic hydrocarbons to Atlantic Canada: geographic and temporal distributions and trends 1980-2001.

    PubMed

    Brun, Guy L; Vaidya, Om C; Léger, Martin G

    2004-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants. The semivolatile organic compounds may disperse into the atmosphere by direct input from several sources such as the burning of fossil fuels, from motor vehicle emissions, and forest fires. Once in the atmosphere, they may travel great distances before being deposited to the earth's surface by the scavenging action of rain and snow. Up to 14 PAHs were determined in wet precipitation samples collected monthly from five sites in the four Canadian Atlantic Provinces during 1980-2001. The relatively more volatile PAHs (phenanthrene, fluoranthene, naphthalene, and pyrene) were predominant in the samples. Significant (P < 0.05) spatial variations in the deposition of some PAHs were observed among sites, but there were no consistent geographic patterns. Seasonal patterns were discernible with peak deposition for sigma6&14 PAHs occurring during the colder months of the year (December to March) and coinciding with higher energy consumption for heating and transport. The monthly volume weighed mean concentration for sigma6 PAHs has declined steadily since the mid-1980s at Kejimkujik National Park in southwest Nova Scotia, with a calculated half-life of 6.4 +/- 0.3 years. The maximum annual deposition flux of 20 microg m(-2) yr(-1) reached in 1985 for sigma6 PAHs decreased approximately 1 order of magnitude by the year 2000. The decrease in sigma6&14 PAHs for the region was found to be correlated (P < 0.05) with decreasing sulfate ion concentrations in the precipitation. The implementation of air pollution abatement programs in Canada, the United States, and elsewhere, switching to cleaner sources of energy and improved technology during the pastfew decades is most likely responsible for the observed decline.

  6. 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.

  7. 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

  8. Trends of geographic inequalities in the distribution of human resources in healthcare system: the case of Iran

    PubMed Central

    Sefiddashti, Sara Emamgholipour; Arab, Mohammad; Ghazanfari, Sadegh; Kazemi, Zhila; Rezaei, Satar; Karyani, Ali Kazemi

    2016-01-01

    Introduction Considering the scarcity of skilled workers in the health sector, the appropriate distribution of human resources in this sector is very important for improving people’s health. Having information about the degree of equality in the distribution of health human resources and their time trends is necessary for better planning and efficient use of these resources. The aim of this study was to determine the trend of inequality in the allocation of human resources in the health sector in Tehran between 2007 and 2013. Methods This cross-sectional study was conducted in Tehran Province in Iran. The inequality in the distribution of human resources (specialists, general practitioners, pharmacists, paramedics, dentists, nurses and community health workers (Behvarz)) in 10 cities in Tehran Province was investigated using the Gini coefficient and the dissimilarity index. The time trend of inequality was examined by regression analysis. The required data were collected from the statistical yearbook of the Iran Statistics Center (ISC). Results The highest value of the Gini coefficient (GC) was related to nurses (GC = 0.291) in 2007. The highest value of the Gini coefficient was related to nurses and Behvarzs in 2008 and 2009, respectively. The distribution of specialists had the highest inequality in 2010 (GC = 0.298), 2011 (GC = 0.300) and 2013 (GC = 0.316). General practitioners had the lowest Gini coefficient for 2007, 2008 and 2012. Nurses for 2009 and Behvarzs for 2010, 2011 and 2013 had the lowest value of Gini coefficient. The dissimilarity indexes for specialists and general practitioners were 26.64 and 8.72 in 2013, respectively. The means of this index for included resources were 31.35, 18.27, 16.91, 22.32, 15.82, 26.74, and 24.33, respectively. The time trend analysis showed that the coefficient of time was positive for all of the human resources, except Behvarzes, and only the coefficient of general practitioners was statistically significant ( p<0

  9. The geographical pattern of distribution of the genus Tityobuthus Pocock, 1890, a typical Ananterinae element endemic to Madagascar (Scorpiones: Buthidae).

    PubMed

    Lourenço, Wilson R; Waeber, Patrick O; Wilmé, Lucienne

    2016-01-01

    New comments are proposed for the Ananterinae (sensu Pocock) or the 'Ananteris Group'. The worldwide pattern of distribution of the elements associated with the Ananterinae, as well as aspects of their ecology, is discussed. The biogeographic patterns presented by extant and fossil elements of this group confirm not only the characteristics of a lineage representing a typical Gondwanian distribution, but correspond also to older Pangean patterns. One new species is described in the genus Tityobuthus Pocock. This new species is also a possible endemic element to the Island of Nosy-Be or at least to the Sambirano region. Generally, the Madagascar pattern of Tityobuthus is following the Neogrosphus rule, showing typical high species richness with low dispersal when the ancestral population had a large niche breadth.

  10. 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.

  11. 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.

  12. 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).

  13. 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

  14. Amount and distribution of dietary protein affects clinical response to levodopa in Parkinson's disease.

    PubMed

    Carter, J H; Nutt, J G; Woodward, W R; Hatcher, L F; Trotman, T L

    1989-04-01

    Reducing dietary protein improves the effectiveness of levodopa (LD) but the most effective distribution of a low-protein diet (0.8 g/kg) is unclear. We compared a 1.6 g/kg protein diet, a 0.8 g/kg diet with protein evenly distributed between meals, and a 0.8 g/kg diet with protein restricted to the evening meal in 5 parkinsonian patients with motor fluctuations. We monitored clinical response, plasma LD, and plasma large amino acids (LNAAs) hourly throughout the day. Mean "on" times were 51% (1.6 g/kg diet), 67% (0.8 g/kg evenly distributed), and 77% (0.8 g/kg restricted). Hourly averages of plasma LD did not differ between the diets. The mean plasma LNAAs were 732 nmol/ml (1.6 g/kg diet), 640 (0.8 g/kg distributed), and 542 (0.8 g/kg restricted), and the diurnal pattern reflected the distribution of protein intake. In conclusion, the amount and distribution of dietary protein affect clinical response to LD. These effects are not related to LD absorption but are explained by the variation in plasma LNAAs.

  15. 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.

  16. 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

  17. Geographical Theories.

    ERIC Educational Resources Information Center

    Golledge, Reginald G.

    1996-01-01

    Discusses the origin of theories in geography and particularly the development of location theories. Considers the influence of economic theory on agricultural land use, industrial location, and geographic location theories. Explores a set of interrelated activities that show how the marketing process illustrates process theory. (MJP)

  18. Two new stygobiotic species of Elaphoidella (Crustacea: Copepoda: Harpacticoida) with comments on geographical distribution and ecology of harpacticoids from caves in Thailand.

    PubMed

    Watiroyram, Santi; Brancelj, Anton; Sanoamuang, La-Orsri

    2015-02-16

    Elaphoidella thailandensis sp. nov. and E. jaesornensis sp. nov., collected during an investigation of cave-dwelling copepod fauna in the northern part of Thailand, are described and figured herein. The new species were collected from pools filled by percolating water from the unsaturated zone of a karstic aquifer in Phitsanulok and Lampang Provinces, respectively. Elaphoidella thailandensis, from Tham Khun cave, is distinguished from its congeners by the two-segmented endopod of pediger 1, the absence of endopod on pediger 4, and the setal formula 4, 5, 6 for the distal exopodal segment of pedigers 2-4. Elaphoidella jaesornensis, from Tham Phar Ngam cave, is distinguished from its most closely related species, E. namnaoensis Brancelj, Watiroyram & Sanoamuang, 2010, by the armature formula of the endopod of pedigers 2-5. The geographical distribution and ecology of Harpacticoida from Thai caves is also presented.