WorldWideScience

Sample records for geographic range size

  1. Global patterns of geographic range size in birds.

    Directory of Open Access Journals (Sweden)

    C David L Orme

    2006-07-01

    Full Text Available Large-scale patterns of spatial variation in species geographic range size are central to many fundamental questions in macroecology and conservation biology. However, the global nature of these patterns has remained contentious, since previous studies have been geographically restricted and/or based on small taxonomic groups. Here, using a database on the breeding distributions of birds, we report the first (to our knowledge global maps of variation in species range sizes for an entire taxonomic class. We show that range area does not follow a simple latitudinal pattern. Instead, the smallest range areas are attained on islands, in mountainous areas, and largely in the southern hemisphere. In contrast, bird species richness peaks around the equator, and towards higher latitudes. Despite these profoundly different latitudinal patterns, spatially explicit models reveal a weak tendency for areas with high species richness to house species with significantly smaller median range area. Taken together, these results show that for birds many spatial patterns in range size described in geographically restricted analyses do not reflect global rules. It remains to be discovered whether global patterns in geographic range size are best interpreted in terms of geographical variation in species assemblage packing, or in the rates of speciation, extinction, and dispersal that ultimately underlie biodiversity.

  2. Geographic range size and determinants of avian species richness

    DEFF Research Database (Denmark)

    Jetz, Walter; Rahbek, Carsten

    2002-01-01

    Geographic patterns in species richness are mainly based on wide-ranging species because their larger number of distribution records has a disproportionate contribution to the species richness counts. Here we demonstrate how this effect strongly influences our understanding of what determines...... species richness. Using both conventional and spatial regression models, we show that for sub-Saharan African birds, the apparent role of productivity diminishes with decreasing range size, whereas the significance of topographic heterogeneity increases. The relative importance of geometric constraints...... from the continental edge is moderate. Our findings highlight the failure of traditional species richness models to account for narrow-ranging species that frequently are also threatened....

  3. Geographic range size and extinction risk assessment in nomadic species

    Science.gov (United States)

    Runge, Claire A; Tulloch, Ayesha; Hammill, Edd; Possingham, Hugh P; Fuller, Richard A

    2015-01-01

    Geographic range size is often conceptualized as a fixed attribute of a species and treated as such for the purposes of quantification of extinction risk; species occupying smaller geographic ranges are assumed to have a higher risk of extinction, all else being equal. However many species are mobile, and their movements range from relatively predictable to-and-fro migrations to complex irregular movements shown by nomadic species. These movements can lead to substantial temporary expansion and contraction of geographic ranges, potentially to levels which may pose an extinction risk. By linking occurrence data with environmental conditions at the time of observations of nomadic species, we modeled the dynamic distributions of 43 arid-zone nomadic bird species across the Australian continent for each month over 11 years and calculated minimum range size and extent of fluctuation in geographic range size from these models. There was enormous variability in predicted spatial distribution over time; 10 species varied in estimated geographic range size by more than an order of magnitude, and 2 species varied by >2 orders of magnitude. During times of poor environmental conditions, several species not currently classified as globally threatened contracted their ranges to very small areas, despite their normally large geographic range size. This finding raises questions about the adequacy of conventional assessments of extinction risk based on static geographic range size (e.g., IUCN Red Listing). Climate change is predicted to affect the pattern of resource fluctuations across much of the southern hemisphere, where nomadism is the dominant form of animal movement, so it is critical we begin to understand the consequences of this for accurate threat assessment of nomadic species. Our approach provides a tool for discovering spatial dynamics in highly mobile species and can be used to unlock valuable information for improved extinction risk assessment and conservation

  4. Habitat area and climate stability determine geographical variation in plant species range sizes

    DEFF Research Database (Denmark)

    Morueta-Holme, Naia; Enquist, Brian J.; McGill, Brian J.

    2013-01-01

    Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~85...

  5. Adult and larval traits as determinants of geographic range size among tropical reef fishes.

    Science.gov (United States)

    Luiz, Osmar J; Allen, Andrew P; Robertson, D Ross; Floeter, Sergio R; Kulbicki, Michel; Vigliola, Laurent; Becheler, Ronan; Madin, Joshua S

    2013-10-01

    Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes.

  6. A macrophysiological analysis of energetic constraints on geographic range size in mammals.

    Directory of Open Access Journals (Sweden)

    Salvatore J Agosta

    Full Text Available Physiological processes are essential for understanding the distribution and abundance of organisms, and recently, with widespread attention to climate change, physiology has been ushered back to the forefront of ecological thinking. We present a macrophysiological analysis of the energetics of geographic range size using combined data on body size, basal metabolic rate (BMR, phylogeny and range properties for 574 species of mammals. We propose three mechanisms by which interspecific variation in BMR should relate positively to geographic range size: (i Thermal Plasticity Hypothesis, (ii Activity Levels/Dispersal Hypothesis, and (iii Energy Constraint Hypothesis. Although each mechanism predicts a positive correlation between BMR and range size, they can be further distinguished based on the shape of the relationship they predict. We found evidence for the predicted positive relationship in two dimensions of energetics: (i the absolute, mass-dependent dimension (BMR and (ii the relative, mass-independent dimension (MIBMR. The shapes of both relationships were similar and most consistent with that expected from the Energy Constraint Hypothesis, which was proposed previously to explain the classic macroecological relationship between range size and body size in mammals and birds. The fact that this pattern holds in the MIBMR dimension indicates that species with supra-allometric metabolic rates require among the largest ranges, above and beyond the increasing energy demands that accrue as an allometric consequence of large body size. The relationship is most evident at high latitudes north of the Tropics, where large ranges and elevated MIBMR are most common. Our results suggest that species that are most vulnerable to extinction from range size reductions are both large-bodied and have elevated MIBMR, but also, that smaller species with elevated MIBMR are at heightened risk. We also provide insights into the global latitudinal trends in range

  7. A macrophysiological analysis of energetic constraints on geographic range size in mammals.

    Science.gov (United States)

    Agosta, Salvatore J; Bernardo, Joseph; Ceballos, Gerardo; Steele, Michael A

    2013-01-01

    Physiological processes are essential for understanding the distribution and abundance of organisms, and recently, with widespread attention to climate change, physiology has been ushered back to the forefront of ecological thinking. We present a macrophysiological analysis of the energetics of geographic range size using combined data on body size, basal metabolic rate (BMR), phylogeny and range properties for 574 species of mammals. We propose three mechanisms by which interspecific variation in BMR should relate positively to geographic range size: (i) Thermal Plasticity Hypothesis, (ii) Activity Levels/Dispersal Hypothesis, and (iii) Energy Constraint Hypothesis. Although each mechanism predicts a positive correlation between BMR and range size, they can be further distinguished based on the shape of the relationship they predict. We found evidence for the predicted positive relationship in two dimensions of energetics: (i) the absolute, mass-dependent dimension (BMR) and (ii) the relative, mass-independent dimension (MIBMR). The shapes of both relationships were similar and most consistent with that expected from the Energy Constraint Hypothesis, which was proposed previously to explain the classic macroecological relationship between range size and body size in mammals and birds. The fact that this pattern holds in the MIBMR dimension indicates that species with supra-allometric metabolic rates require among the largest ranges, above and beyond the increasing energy demands that accrue as an allometric consequence of large body size. The relationship is most evident at high latitudes north of the Tropics, where large ranges and elevated MIBMR are most common. Our results suggest that species that are most vulnerable to extinction from range size reductions are both large-bodied and have elevated MIBMR, but also, that smaller species with elevated MIBMR are at heightened risk. We also provide insights into the global latitudinal trends in range size and MIBMR

  8. A Macrophysiological Analysis of Energetic Constraints on Geographic Range Size in Mammals

    Science.gov (United States)

    Ceballos, Gerardo; Steele, Michael A.

    2013-01-01

    Physiological processes are essential for understanding the distribution and abundance of organisms, and recently, with widespread attention to climate change, physiology has been ushered back to the forefront of ecological thinking. We present a macrophysiological analysis of the energetics of geographic range size using combined data on body size, basal metabolic rate (BMR), phylogeny and range properties for 574 species of mammals. We propose three mechanisms by which interspecific variation in BMR should relate positively to geographic range size: (i) Thermal Plasticity Hypothesis, (ii) Activity Levels/Dispersal Hypothesis, and (iii) Energy Constraint Hypothesis. Although each mechanism predicts a positive correlation between BMR and range size, they can be further distinguished based on the shape of the relationship they predict. We found evidence for the predicted positive relationship in two dimensions of energetics: (i) the absolute, mass-dependent dimension (BMR) and (ii) the relative, mass-independent dimension (MIBMR). The shapes of both relationships were similar and most consistent with that expected from the Energy Constraint Hypothesis, which was proposed previously to explain the classic macroecological relationship between range size and body size in mammals and birds. The fact that this pattern holds in the MIBMR dimension indicates that species with supra-allometric metabolic rates require among the largest ranges, above and beyond the increasing energy demands that accrue as an allometric consequence of large body size. The relationship is most evident at high latitudes north of the Tropics, where large ranges and elevated MIBMR are most common. Our results suggest that species that are most vulnerable to extinction from range size reductions are both large-bodied and have elevated MIBMR, but also, that smaller species with elevated MIBMR are at heightened risk. We also provide insights into the global latitudinal trends in range size and MIBMR

  9. Habitat area and climate stability determine geographical variation in plant species range sizes.

    Science.gov (United States)

    Morueta-Holme, Naia; Enquist, Brian J; McGill, Brian J; Boyle, Brad; Jørgensen, Peter M; Ott, Jeffrey E; Peet, Robert K; Símová, Irena; Sloat, Lindsey L; Thiers, Barbara; Violle, Cyrille; Wiser, Susan K; Dolins, Steven; Donoghue, John C; Kraft, Nathan J B; Regetz, Jim; Schildhauer, Mark; Spencer, Nick; Svenning, Jens-Christian

    2013-12-01

    Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~ 85 000 plant species across the New World. We assess prominent hypothesised range-size controls, finding that plant range sizes are codetermined by habitat area and long- and short-term climate stability. Strong short- and long-term climate instability in large parts of North America, including past glaciations, are associated with broad-ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small-ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen concerns over the potential effects of future climate change and habitat loss on biodiversity.

  10. Habitat area and climate stability determine geographical variation in plant species range sizes

    DEFF Research Database (Denmark)

    Morueta-Holme, Naia; Enquist, Brian J.; McGill, Brian J.

    2013-01-01

    Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~85,000 ...... concerns over the potential effects of future climate change and habitat loss on biodiversity.......,000 plant species across the New World. We assess prominent hypothesised range-size controls, finding that plant range sizes are codetermined by habitat area and long- and short-term climate stability. Strong short- and long-term climate instability in large parts of North America, including past...... glaciations, are associated with broad-ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small-ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen...

  11. Human pressures predict species' geographic range size better than biological traits.

    Science.gov (United States)

    Di Marco, Moreno; Santini, Luca

    2015-06-01

    Geographic range size is the manifestation of complex interactions between intrinsic species traits and extrinsic environmental conditions. It is also a fundamental ecological attribute of species and a key extinction risk correlate. Past research has primarily focused on the role of biological and environmental predictors of range size, but macroecological patterns can also be distorted by human activities. Here, we analyse the role of extrinsic (biogeography, habitat state, climate, human pressure) and intrinsic (biology) variables in predicting range size of the world's terrestrial mammals. In particular, our aim is to compare the predictive ability of human pressure vs. species biology. We evaluated the ability of 19 intrinsic and extrinsic variables in predicting range size for 4867 terrestrial mammals. We repeated the analyses after excluding restricted-range species and performed separate analyses for species in different biogeographic realms and taxonomic groups. Our model had high predictive ability and showed that climatic variables and human pressures are the most influential predictors of range size. Interestingly, human pressures predict current geographic range size better than biological traits. These findings were confirmed when repeating the analyses on large-ranged species, individual biogeographic regions and individual taxonomic groups. Climatic and human impacts have determined the extinction of mammal species in the past and are the main factors shaping the present distribution of mammals. These factors also affect other vertebrate groups globally, and their influence on range size may be similar as well. Measuring climatic and human variables can allow to obtain approximate range size estimations for data-deficient and newly discovered species (e.g. hundreds of mammal species worldwide). Our results support the need for a more careful consideration of the role of climate change and human impact - as opposed to species biological

  12. Physiological, ecological, and behavioural correlates of the size of the geographic ranges of sea kraits (Laticauda; Elapidae, Serpentes): A critique

    Science.gov (United States)

    Heatwole, Harold; Lillywhite, Harvey; Grech, Alana

    2016-09-01

    Recent, more accurate delineation of the distributions of sea kraits and prior dubious use of proxy temperatures and mean values in correlative studies requires re-assessment of the relationships of temperature and salinity as determinants of the size of the geographic ranges of sea kraits. Correcting the sizes of geographic ranges resolved the paradox of lack of correspondence of size of range with degree of terrestrialism, but did not form a definitive test of the theory. Recent ecological, physiological, and behavioural studies provide an example of the kind of approach likely to either validate or refute present theory.

  13. Do turtles follow the rules? Latitudinal gradients in species richness, body size, and geographic range area of the world's turtles.

    Science.gov (United States)

    Angielczyk, Kenneth D; Burroughs, Robert W; Feldman, Chris R

    2015-05-01

    Understanding how and why biodiversity is structured across the globe has been central to ecology, evolution, and biogeography even before those disciplines took their modern forms. Three global-scale patterns in particular have been the focus of research and debate for decades: latitudinal gradients in species richness (richness decreases with increasing latitude), body size (body size increases with increasing latitude in endotherms; Bergmann's rule), and geographic range size (range size increases with increasing latitude; Rapoport's rule). Despite decades of study, the generality and robustness of these trends have been debated, as have their underlying causes. Here we investigate latitudinal gradients in species richness, body size, and range size in the world's turtles (Testudines), and add more evidence that these rules do not seem to apply across all taxa. We show that turtle diversity actually peaks at 25° north, a highly unusual global pattern. Turtles also fail to follow Bergmann's Rule, and may show the converse (larger at lower latitudes), though trends are weak. Turtles also show a complex relationship between latitude and range size that does not directly follow Rapoport's rule. Body size and geographic range size are significantly correlated, and multiple abiotic and biotic variables help explain the relationships between latitude and species diversity, body size, and range size. Although we show that turtles do not strictly follow some classic biogeographical rules, we also call for further in-depth research to investigate potential causal mechanisms for these atypical patterns.

  14. Hominin geographical range dynamics and relative brain size: Do non-human primates provide a good analogy?

    Science.gov (United States)

    MacDonald, Katharine; Smaers, Jeroen B; Steele, James

    2015-10-01

    We use climatic and satellite remote sensing data to characterize environmental seasonality in the geographical ranges of extant non-human primates in order to assess the effect of relative brain size on tolerance of more seasonal habitats. Demonstration of such an effect in living non-human primates could provide a comparative framework for modeling hominin dispersals and geographical range dynamics in the Pliocene and Pleistocene. Our analyses found no such effect: there are neither positive nor negative correlations between relative brain size and either geographical range size or the average and range of values for environmental seasonality, whether analysed at the level of all primates, or within parvorders (strepsirrhine, catarrhine, platyrrhine). Independent analyses by other researchers comparing feeding behaviour and ecology at individual primate study sites demonstrate that in seasonal environments, the year-round metabolic costs of maintaining a relatively large brain are met by adaptive behavioural/dietary strategies. However, consistent with our own results, those comparative studies found that there was no overall association, whether positive or negative, between 'raw' environmental seasonality and primate relative brain size. We must therefore look elsewhere for a comparative model of hominin geographical range dynamics in the Pleistocene.

  15. Body size and geographic range do not explain long term variation in fish populations: a Bayesian phylogenetic approach to testing assembly processes in stream fish assemblages.

    Directory of Open Access Journals (Sweden)

    Stephen J Jacquemin

    Full Text Available We combine evolutionary biology and community ecology to test whether two species traits, body size and geographic range, explain long term variation in local scale freshwater stream fish assemblages. Body size and geographic range are expected to influence several aspects of fish ecology, via relationships with niche breadth, dispersal, and abundance. These traits are expected to scale inversely with niche breadth or current abundance, and to scale directly with dispersal potential. However, their utility to explain long term temporal patterns in local scale abundance is not known. Comparative methods employing an existing molecular phylogeny were used to incorporate evolutionary relatedness in a test for covariation of body size and geographic range with long term (1983 - 2010 local scale population variation of fishes in West Fork White River (Indiana, USA. The Bayesian model incorporating phylogenetic uncertainty and correlated predictors indicated that neither body size nor geographic range explained significant variation in population fluctuations over a 28 year period. Phylogenetic signal data indicated that body size and geographic range were less similar among taxa than expected if trait evolution followed a purely random walk. We interpret this as evidence that local scale population variation may be influenced less by species-level traits such as body size or geographic range, and instead may be influenced more strongly by a taxon's local scale habitat and biotic assemblages.

  16. Geographical range and local abundance of tree species in China.

    Directory of Open Access Journals (Sweden)

    Haibao Ren

    Full Text Available Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1 whether locally abundant species tend to be geographically widespread; 2 whether species are more abundant towards their range-centers; and 3 how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20-25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km(2, and >90% of 651 species had ranges >10(5 km(2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species' abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.

  17. Range size: Disentangling Current Traits and Phylogenetic and Biogeographic Factors

    NARCIS (Netherlands)

    Bohning-Gaese, K.; Caprano, T.; van Ewijk, K.; Veith, M.K.H.

    2006-01-01

    The range size of a species can be determined by its current traits and by phylogenetic and biogeographic factors. However, only rarely have these factors been studied in combination. We use data on the geographic range sizes of all 26 Sylvia warblers to explicitly test whether range size was

  18. Niche breadth and geographical range: ecological compensation for geographical rarity in rainforest frogs

    OpenAIRE

    Williams, Yvette M; Williams, Stephen E.; Ross A Alford; Waycott, Michelle; Johnson, Christopher N.

    2006-01-01

    We investigated the relationship between diet specialization and geographical range in Cophixalus, a genus of microhylid frogs from the Wet Tropics of northern Queensland, Australia. The geographical ranges of these species vary from a few square kilometres in species restricted to a single mountain top to the entire region for the widespread species. Although macroecological theory predicts that species with broad niches should have the largest geographical ranges, we found the opposite: geo...

  19. Niche breadth and geographical range: ecological compensation for geographical rarity in rainforest frogs.

    Science.gov (United States)

    Williams, Yvette M; Williams, Stephen E; Alford, Ross A; Waycott, Michelle; Johnson, Christopher N

    2006-12-22

    We investigated the relationship between diet specialization and geographical range in Cophixalus, a genus of microhylid frogs from the Wet Tropics of northern Queensland, Australia. The geographical ranges of these species vary from a few square kilometres in species restricted to a single mountain top to the entire region for the widespread species. Although macroecological theory predicts that species with broad niches should have the largest geographical ranges, we found the opposite: geographically rare species were diet generalists and widespread species were diet specialists. We argue that this pattern is a product of extinction filtering, whereby geographically rare and therefore extinction-prone species are more likely to persist if they are diet generalists.

  20. Geographic variation in body size and sexual size dimorphism of a seed-feeding beetle.

    Science.gov (United States)

    Stillwell, R Craig; Morse, Geoffrey E; Fox, Charles W

    2007-09-01

    Body size of many animals varies with latitude: body size is either larger at higher latitudes (Bergmann's rule) or smaller at higher latitudes (converse Bergmann's rule). However, the causes underlying these patterns are poorly understood. Also, studies rarely explore how sexual size dimorphism varies with latitude. Here we investigate geographic variation in body size and sexual size dimorphism of the seed-feeding beetle Stator limbatus, collected from 95 locations along a 38 degrees range in latitude. We examine 14 variables to test whether clines in environmental factors are adequate to explain geographic patterns of body size. We found that body size and sexual size dimorphism of S. limbatus varied considerably with latitude; beetles were smaller but more dimorphic at lower latitudes. Body size was not correlated with a gradient in mean temperature, contrary to the commonly accepted hypothesis that clines are produced by latitudinal gradients in temperature. Instead, we found that three factors were adequate to explain the cline in body size: clinal variation in host plant seed size, moisture (humidity), and seasonality (variance in humidity, precipitation, and temperature). We also found that the cline in sexual size dimorphism was partially explainable by a gradient in moisture, though moisture alone was not sufficient to explain the cline. Other ecological or environmental variables must necessarily contribute to differences in selection on male versus female body size. The main implications of our study are that the sexes differ in the magnitude of clinal variation in body size, creating latitudinal variation in sexual size dimorphism, and that clines in body size of seed beetles are likely influenced by variation in host seed size, water availability, and seasonality.

  1. Length of activity season drives geographic variation in body size of a widely distributed lizard

    OpenAIRE

    Horváthová, Terézia; Cooney, Christopher R.; Fitze, Patrick S; Oksanen, Tuula; Jelic, Dusan; Ghira, Ioan; Uller, Tobias; Jandzik, David

    2013-01-01

    Understanding the factors that drive geographic variation in life history is an important challenge in evolutionary ecology. Here, we analyze what predicts geographic variation in life-history traits of the common lizard, Zootoca vivipara, which has the globally largest distribution range of all terrestrial reptile species. Variation in body size was predicted by differences in the length of activity season, while we found no effects of environmental temperature per se. Females experiencing r...

  2. Inversion of spheroid particle size distribution in wider size range and aspect ratio range

    Directory of Open Access Journals (Sweden)

    Tang Hong

    2013-01-01

    Full Text Available The non-spherical particle sizing is very important in the aerosol science, and it can be determined by the light extinction measurement. This paper studies the effect of relationship of the size range and aspect ratio range on the inversion of spheroid particle size distribution by the dependent mode algorithm. The T matrix method and the geometric optics approximation method are used to calculate the extinction efficiency of the spheroids with different size range and aspect ratio range, and the inversion of spheroid particle size distribution in these different ranges is conducted. Numerical simulation indicates that a fairly reasonable representation of the spheroid particle size distribution can be obtained when the size range and aspect ratio range are suitably chosen.

  3. Towards biodiversity hotspots effective for conserving mammals with small geographic ranges

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    Carrara, Rodolfo; San Blas, Germán; Agrain, Federico; Roig-Juñent, Sergio

    2017-01-01

    The main goal of using global biodiversity hotspots for conservation purposes is to protect taxa with small geographic ranges because these are highly vulnerable to extinction. However, the extent to what different hotspots types are effective for meeting this goal remains controversial because hotspots have been previously defined as either the richest or most threatened and richest sites in terms of total, endemic or threatened species. In this regard, the use of species richness to set conservation priorities is widely discussed because strategies focused on this diversity measure tend to miss many of the taxa with small geographic ranges. Here we use data on global terrestrial mammal distributions to show that, hotspots of total species, endemism and threat defined in terms of species richness are effective in including 27%, 29% and 11% respectively, of the taxa with small geographic ranges. Whilst, the same hotspot types defined in terms of a simple diversity index, which is a function of species richness and range-size rarity, include 68%, 44% and 90% respectively, of these taxa. In addition, we demonstrate that index hotspot types are highly efficient because they conserve 79% of mammal species (21% more species than richness hotspot types), with 59% of species shared by three hotspot types (31% more than richness hotspot types). These results suggest that selection of different diversity measures to define hotspots may strongly affect the achievement of conservation goals.

  4. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor across Its Geographic Range.

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    John D Lloyd

    Full Text Available Mangrove Cuckoo (Coccyzus minor exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are invalid. Greatest differences in phenotype occurred between populations in Florida, the Bahamas, and the Greater Antilles--characteristically small-billed--and those in the Lesser Antilles, which had larger bills. Phenotypically intermediate individuals on the geographically intermediate islands of Barbuda and Antigua linked these two extremes. Individuals intermediate in bill size and color also characterized populations from throughout the remainder of the range in northern South America and Middle America. Mechanisms maintaining the fairly pronounced phenotypic differences between nearby populations of Greater and Lesser Antillean birds are unknown, yet the geographic proximity of these populations suggests that they probably persist despite occasional gene flow, and may be adaptive.

  5. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor) across Its Geographic Range.

    Science.gov (United States)

    Lloyd, John D

    2016-01-01

    Mangrove Cuckoo (Coccyzus minor) exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are invalid. Greatest differences in phenotype occurred between populations in Florida, the Bahamas, and the Greater Antilles--characteristically small-billed--and those in the Lesser Antilles, which had larger bills. Phenotypically intermediate individuals on the geographically intermediate islands of Barbuda and Antigua linked these two extremes. Individuals intermediate in bill size and color also characterized populations from throughout the remainder of the range in northern South America and Middle America. Mechanisms maintaining the fairly pronounced phenotypic differences between nearby populations of Greater and Lesser Antillean birds are unknown, yet the geographic proximity of these populations suggests that they probably persist despite occasional gene flow, and may be adaptive.

  6. Predicted geographic ranges for North American sylvatic Trichinella

    Science.gov (United States)

    Because of a lack of comprehensive surveys, the geographic distributions of the North American species of Trichinella (T. nativa and its variant T6, T. murrelli, and T. spiralis) are poorly characterized. These species are potentially zoonotic, and biogeographical information is critical to monitori...

  7. Are range-size distributions consistent with species-level heritability?

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe; Gotelli, Nicholas; Rahbek, Carsten

    2012-01-01

    been that it is not compatible with the observed shape of present-day species range-size distributions (SRDs), a claim that has never been tested. To assess this claim, we used forward simulation of range-size evolution in clades with varying degrees of range-size heritability, and compared the output...... of three different models to the range-size distribution of the South American avifauna. Although there were differences among the models, a moderate-to-high degree of range-size heritability consistently leads to SRDs that were similar to empirical data. These results suggest that range-size heritability......The concept of species-level heritability is widely contested. Because it is most likely to apply to emergent, species-level traits, one of the central discussions has focused on the potential heritability of geographic range size. However, a central argument against range-size heritability has...

  8. Geographical ranges in macroecology: Processes, patterns and implications

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe

    , I draw upon a wide range of approaches, including statistical comparative analysis, computer simulations and null models. The core of the thesis is constituted by five independent scientific articles. These chapters fall naturally within two thematic groups: The first group consists of articles...... that investigate how ecology and evolution determine species’ ranges. The central paper in this group is a large review article about one of the best described patterns in ecology: That species with large ranges tend to also be very locally abundant within their range. In the article I review the potential causes...

  9. Geographic ranges of ascidians from Antarctica and the southeastern Pacific

    Institute of Scientific and Technical Information of China (English)

    Dirk Schories; Karen Sanamyan; Nadja Sanamyan; Mara Jos Daz; Ignacio Garrido; Thomas Heran; Jorge Holtheuer; Gesche Kohlberg

    2015-01-01

    Historical and novel data on the geographic and bathymetric distribution of ascidians from Antarctic, Magellan and Chilean waters are compiled, and an inventory of taxa comprising 162 species reported over a 150 year period from the Antarctic region South Polar Province (SPP) compiled. The ascidian fauna from the South Shetland Islands (SSI) is compared with that of the Magellan region, Patagonia and the Chilean coast. We collected 46 ascidian species along the Chilean coast, and during four expeditions to King George Island (SSI) by SCUBA between 2003–2012. About 15% of King George Island (SSI) species are observed to occur also in shallow waters of southern Chile (SCL). Few species known from warm temperate southeastern Pacific (Northern Chile, NCL) waters are absent from the Chilean part of the Magellan Province (SCL). With most data contributed from the Chilean coast coming from the SCL, and with limited sampling having been undertaken at depths exceeding 100 m in the NCL, apparent differences in species richness along the Chilean coast could be attributabed to differential sampling effort. We detail 12 species from our Antarctic and Chilean collections in detail, including one, Diplosoma listerianum, not previously reported from Chilean waters, and the genus Botryllus, previously known from them on the basis of a single record.

  10. No association between plant mating system and geographic range overlap.

    Science.gov (United States)

    Grossenbacher, Dena; Briscoe Runquist, Ryan D; Goldberg, Emma E; Brandvain, Yaniv

    2016-01-01

    Automatic self-fertilization may influence the geography of speciation, promote reproductive isolation between incipient species, and lead to ecological differentiation. As such, selfing taxa are predicted to co-occur more often with their closest relatives than are outcrossing taxa. Despite suggestions that this pattern may be general, the extent to which mating system influences range overlap in close relatives has not been tested formally across a diverse group of plant species pairs. We tested for a difference in range overlap between species pairs for which zero, one, or both species are selfers, using data from 98 sister species pairs in 20 genera across 15 flowering plant families. We also used divergence time estimates from time-calibrated phylogenies to ask how range overlap changes with divergence time and whether this effect depends on mating system. We found no evidence that automatic self-fertilization influenced range overlap of closely related plant species. Sister pairs with more recent divergence times had modestly greater range overlap, but this effect did not depend on mating system. The absence of a strong influence of mating system on range overlap suggests that mating system plays a minor or inconsistent role compared with many other mechanisms potentially influencing the co-occurrence of close relatives. © 2016 Botanical Society of America.

  11. Wide size range fast integrated mobility spectrometer

    Science.gov (United States)

    Wang, Jian

    2013-10-29

    A mobility spectrometer to measure a nanometer particle size distribution is disclosed. The mobility spectrometer includes a conduit and a detector. The conduit is configured to receive and provide fluid communication of a fluid stream having a charged nanometer particle mixture. The conduit includes a separator section configured to generate an electrical field of two dimensions transverse to a dimension associated with the flow of the charged nanometer particle mixture through the separator section to spatially separate charged nanometer particles of the charged nanometer particle mixture in said two dimensions. The detector is disposed downstream of the conduit to detect concentration and position of the spatially-separated nanometer particles.

  12. Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis

    Science.gov (United States)

    King, Richard B.; Adamski, John M.; Anton, Thomas G.; Bailey, Robyn L.; Baker, Sarah J.; Bieser, Nickolas D.; Bell, Thomas A.; Bissell, Kristin M.; Bradke, Danielle R.; Campa, Henry; Casper, Gary S.; Cedar, Karen; Cross, Matthew D.; DeGregorio, Brett A.; Dreslik, Michael J.; Faust, Lisa J.; Harvey, Daniel S.; Hay, Robert W.; Jellen, Benjamin C.; Johnson, Brent D.; Johnson, Glenn; Kiel, Brooke D.; Kingsbury, Bruce A.; Kowalski, Matthew J.; Lee, Yu Man; Lentini, Andrew M.; Marshall, John C.; Mauger, David; Moore, Jennifer A.; Paloski, Rori A.; Phillips, Christopher A.; Pratt, Paul D.; Preney, Thomas; Prior, Kent A.; Promaine, Andrew; Redmer, Michael; Reinert, Howard K.; Rouse, Jeremy D.; Shoemaker, Kevin T.; Sutton, Scott; VanDeWalle, Terry J.; Weatherhead, Patrick J.; Wynn, Doug; Yagi, Anne

    2017-01-01

    Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size–fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size–fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change. PMID:28196149

  13. Size and type of places, geographical region, satisfaction with life, age, sex and place attachment

    Directory of Open Access Journals (Sweden)

    Mandal Alan

    2016-04-01

    Full Text Available The topic of the article concerns the issue of place attachment and its determinants. An analysis of place attachment was performed in terms of place identity and place dependence (Williams, Vaske, 2003. Moreover, links between place attachment and selected geographical (size and type of place, geographical region, demographic (age, sex and psychological (satisfaction with life variables were investigated.

  14. Mean latitudinal range sizes of bird assemblages in six Neotropical forest chronosequences

    DEFF Research Database (Denmark)

    Dunn, Robert R.; Romdal, Tom Skovlund

    2005-01-01

    Aim The geographical range size frequency distributions of animal and plant assemblages are among the most important factors affecting large-scale patterns of diversity. Nonetheless, the relationship between habitat type and the range size distributions of species forming assemblages remains poorly...... towards more small ranged species occurs. Even relatively old secondary forests have bird species with larger average ranges than mature forests. As a consequence, conservation of secondary forests alone will miss many of the species most at risk of extinction and most unlikely to be conserved in other...

  15. Mutualist-mediated effects on species' range limits across large geographic scales.

    Science.gov (United States)

    Afkhami, Michelle E; McIntyre, Patrick J; Strauss, Sharon Y

    2014-10-01

    Understanding the processes determining species range limits is central to predicting species distributions under climate change. Projected future ranges are extrapolated from distribution models based on climate layers, and few models incorporate the effects of biotic interactions on species' distributions. Here, we show that a positive species interaction ameliorates abiotic stress, and has a profound effect on a species' range limits. Combining field surveys of 92 populations, 10 common garden experiments throughout the range, species distribution models and greenhouse experiments, we show that mutualistic fungal endophytes ameliorate drought stress and broaden the geographic range of their native grass host Bromus laevipes by thousands of square kilometres (~ 20% larger) into drier habitats. Range differentiation between fungal-associated and fungal-free grasses was comparable to species-level range divergence of congeners, indicating large impacts on range limits. Positive biotic interactions may be underappreciated in determining species' ranges and species' responses to future climates across large geographic scales.

  16. Apparatus for handling micron size range particulate material

    Science.gov (United States)

    Friichtenicht, J. F.; Roy, N. L. (Inventor)

    1968-01-01

    An apparatus for handling, transporting, or size classifying comminuted material was described in detail. Electrostatic acceleration techniques for classifying particles as to size in the particle range from 0.1 to about 100 microns diameter were employed.

  17. Genetics and Conservation of Plant Species of Extremely Narrow Geographic Range

    Directory of Open Access Journals (Sweden)

    Sofia Solórzano

    2016-12-01

    Full Text Available The endemic plant species with extremely narrow geographical range (<100 km2 often have few populations of small size and tend to be more vulnerable to extinction by genetic drift and inbreeding effects. For these species, we tested if intraspecific genetic diversity can be applied to identify conservation priorities. The biological model was Mammillaria albiflora—a Mexican cactus that numbers ~1000 individuals distributed in four nearby patches covering 4.3 km2. A total of 96 individuals were genotyped with 10 microsatellite loci to describe the genetic substructure and diversity. There is significant population substructure: the genetic diversity is distributed in three genetic neighbors and varies among the patches, the genotypes are not randomly distributed and three genetic barriers restrict the gene flow. The current population size is 15 times smaller than in the past. The restricted gene flow and genetic drift are the processes that have shaped population substructure. To conserve the genetic diversity of this cactus we recommend that two patches, which are not private property, be legally protected; to include M. albiflora in the Red List Species of Mexico in the category of extinction risk; and a legal propagation program may help to diminish the illegal harvesting.

  18. Range size heritability and diversification patterns in the liverwort genus Radula.

    Science.gov (United States)

    Patiño, Jairo; Wang, Jian; Renner, Matt A M; Gradstein, S Robbert; Laenen, Benjamin; Devos, Nicolas; Shaw, A Jonathan; Vanderpoorten, Alain

    2017-01-01

    Why some species exhibit larger geographical ranges than others, and to what extent does variation in range size affect diversification rates, remains a fundamental, but largely unanswered question in ecology and evolution. Here, we implement phylogenetic comparative analyses and ancestral area estimations in Radula, a liverwort genus of Cretaceous origin, to investigate the mechanisms that explain differences in geographical range size and diversification rates among lineages. Range size was phylogenetically constrained in the two sub-genera characterized by their almost complete Australasian and Neotropical endemicity, respectively. The congruence between the divergence time of these lineages and continental split suggests that plate tectonics could have played a major role in their present distribution, suggesting that a strong imprint of vicariance can still be found in extant distribution patterns in these highly mobile organisms. Amentuloradula, Volutoradula and Metaradula species did not appear to exhibit losses of dispersal capacities in terms of dispersal life-history traits, but evidence for significant phylogenetic signal in macroecological niche traits suggests that niche conservatism accounts for their restricted geographic ranges. Despite their greatly restricted distribution to Australasia and Neotropics respectively, Amentuloradula and Volutoradula did not exhibit significantly lower diversification rates than more widespread lineages, in contrast with the hypothesis that the probability of speciation increases with range size by promoting geographic isolation and increasing the rate at which novel habitats are encountered. We suggest that stochastic long-distance dispersal events may balance allele frequencies across large spatial scales, leading to low genetic structure among geographically distant areas or even continents, ultimately decreasing the diversification rates in highly mobile, widespread lineages. Copyright © 2016 Elsevier Inc. All

  19. Ciguatoxic Potential of Brown-Marbled Grouper in Relation to Fish Size and Geographical Origin

    Science.gov (United States)

    Chan, Thomas Y. K.

    2015-01-01

    To determine the ciguatoxic potential of brown-marbled grouper (Epinephelus fuscoguttatus) in relation to fish size and geographical origin, this review systematically analyzed: 1) reports of large ciguatera outbreaks and outbreaks with description of the fish size; 2) Pacific ciguatoxin (P-CTX) profiles and levels and mouse bioassay results in fish samples from ciguatera incidents; 3) P-CTX profiles and levels and risk of toxicity in relation to fish size and origin; 4) regulatory measures restricting fish trade and fish size preference of the consumers. P-CTX levels in flesh and size dependency of toxicity indicate that the risk of ciguatera after eating E. fuscoguttatus varies with its geographical origin. For a large-sized grouper, it is necessary to establish legal size limits and control measures to protect public health and prevent overfishing. More risk assessment studies are required for E. fuscoguttatus to determine the size threshold above which the risk of ciguatera significantly increases. PMID:26324735

  20. Ciguatoxic Potential of Brown-Marbled Grouper in Relation to Fish Size and Geographical Origin.

    Science.gov (United States)

    Chan, Thomas Y K

    2015-11-01

    To determine the ciguatoxic potential of brown-marbled grouper (Epinephelus fuscoguttatus) in relation to fish size and geographical origin, this review systematically analyzed: 1) reports of large ciguatera outbreaks and outbreaks with description of the fish size; 2) Pacific ciguatoxin (P-CTX) profiles and levels and mouse bioassay results in fish samples from ciguatera incidents; 3) P-CTX profiles and levels and risk of toxicity in relation to fish size and origin; 4) regulatory measures restricting fish trade and fish size preference of the consumers. P-CTX levels in flesh and size dependency of toxicity indicate that the risk of ciguatera after eating E. fuscoguttatus varies with its geographical origin. For a large-sized grouper, it is necessary to establish legal size limits and control measures to protect public health and prevent overfishing. More risk assessment studies are required for E. fuscoguttatus to determine the size threshold above which the risk of ciguatera significantly increases.

  1. Variation in body size and metamorphic traits of Iberian spadefoot toads over a short geographic distance

    OpenAIRE

    2008-01-01

    Determinants of geographic variation in body size are often poorly understood, especially in organisms with complex life cycles. We examined patterns of adult body size and metamorphic traits variation in Iberian spadefoot toad (Pelobates cultripes) populations, which exhibit an extreme reduction in adult body size, 71.6% reduction in body mass, within just about 30 km at south-western Spain. We hypothesized that size at and time to metamorphosis would be predictive of the spatial pattern obs...

  2. INTEGRATING PARASITES AND PATHOGENS INTO THE STUDY OF GEOGRAPHIC RANGE LIMITS.

    Science.gov (United States)

    Bozick, Brooke A; Real, Leslie A

    2015-12-01

    The geographic distributions of all species are limited, and the determining factors that set these limits are of fundamental importance to the fields of ecology and evolutionary biology. Plant and animal ranges have been of primary concern, while those of parasites, which represent much of the Earth's biodiversity, have been neglected. Here, we review the determinants of the geographic ranges of parasites and pathogens, and explore how parasites provide novel systems with which to investigate the ecological and evolutionary processes governing host/parasite spatial distributions. Although there is significant overlap in the causative factors that determine range borders of parasites and free-living species, parasite distributions are additionally constrained by the geographic range and ecology of the host species' population, as well as by evolutionary factors that promote host-parasite coevolution. Recently, parasites have been used to infer population demographic and ecological information about their host organisms and we conclude that this strategy can be further exploited to understand geographic range limitations of both host and parasite populations.

  3. Climate and topography explain range sizes of terrestrial vertebrates

    Science.gov (United States)

    Li, Yiming; Li, Xianping; Sandel, Brody; Blank, David; Liu, Zetian; Liu, Xuan; Yan, Shaofei

    2016-05-01

    Identifying the factors that influence range sizes of species provides important insight into the distribution of biodiversity, and is crucial for predicting shifts in species ranges in response to climate change. Current climate (for example, climate variability and climate extremes), long-term climate change, evolutionary age, topographic heterogeneity, land area and species traits such as physiological thermal limits, dispersal ability, annual fecundity and body size have been shown to influence range size. Yet, few studies have examined the generality of each of these factors among different taxa, or have simultaneously evaluated the strength of relationships between range size and these factors at a global scale. We quantify contributions of these factors to range sizes of terrestrial vertebrates (mammals, birds and reptiles) at a global scale. We found that large-ranged species experience greater monthly extremes of maximum or minimum temperature within their ranges, or occur in areas with higher long-term climate velocity and lower topographic heterogeneity or lower precipitation seasonality. Flight ability, body mass and continent width are important only for particular taxa. Our results highlight the importance of climate and topographic context in driving range size variation. The results suggest that small-range species may be vulnerable to climate change and should be the focus of conservation efforts.

  4. Dispersal, niche breadth and population extinction: colonization ratios predict range size in North American dragonflies.

    Science.gov (United States)

    McCauley, Shannon J; Davis, Christopher J; Werner, Earl E; Robeson, Michael S

    2014-07-01

    Species' range sizes are shaped by fundamental differences in species' ecological and evolutionary characteristics, and understanding the mechanisms determining range size can shed light on the factors responsible for generating and structuring biological diversity. Moreover, because geographic range size is associated with a species' risk of extinction and their ability to respond to global changes in climate and land use, understanding these mechanisms has important conservation implications. Despite the hypotheses that dispersal behaviour is a strong determinant of species range areas, few data are available to directly compare the relationship between dispersal behaviour and range size. Here, we overcome this limitation by combining data from a multispecies dispersal experiment with additional species-level trait data that are commonly hypothesized to affect range size (e.g. niche breadth, local abundance and body size.). This enables us to examine the relationship between these species-level traits and range size across North America for fifteen dragonfly species. Ten models based on a priori predictions about the relationship between species traits and range size were evaluated and two models were identified as good predictors of species range size. These models indicated that only two species' level traits, dispersal behaviour and niche breadth were strongly related to range size. The evidence from these two models indicated that dragonfly species that disperse more often and further had larger North American ranges. Extinction and colonization dynamics are expected to be a key linkage between dispersal behaviour and range size in dragonflies. To evaluate how extinction and colonization dynamics among dragonflies were related to range size we used an independent data set of extinction and colonization rates for eleven dragonfly species and assessed the relationship between these populations rates and North American range areas for these species. We found a

  5. Ciguatoxic Potential of Brown-Marbled Grouper in Relation to Fish Size and Geographical Origin

    OpenAIRE

    Thomas Y. K. Chan

    2015-01-01

    To determine the ciguatoxic potential of brown-marbled grouper (Epinephelus fuscoguttatus) in relation to fish size and geographical origin, this review systematically analyzed: 1) reports of large ciguatera outbreaks and outbreaks with description of the fish size; 2) Pacific ciguatoxin (P-CTX) profiles and levels and mouse bioassay results in fish samples from ciguatera incidents; 3) P-CTX profiles and levels and risk of toxicity in relation to fish size and origin; 4) regulatory measures r...

  6. Negative range size-abundance relationships in Indo-Pacific bird communities

    DEFF Research Database (Denmark)

    Hart Reeve, Andrew; Borregaard, Michael Krabbe; Fjeldså, Jon

    2016-01-01

    -Pacific, namely Flores in the Lesser Sundas, Seram in the Moluccas, and the New Caledonian islands of Grande Terre and Lifou. Local abundance data was gathered through extensive and methodologically consistent surveying, and regressed against global range size using linear mixed effect models. The relationship......The positive relationship between range size and abundance is one of the best-documented patterns in macroecology, but a growing number of studies from isolated tropical areas have reported negative or neutral relationships. It has been hypothesized that the combination of geographic isolation...... between range size and abundance was significantly negative across all combined mature and degraded forest communities. As negative relationships were found in degraded forest with little environmental stability, we conclude that the abundance of small-ranged species on the study islands cannot...

  7. 75 FR 27286 - McKelvie Geographic Area Range Allotment Management Planning on the Samuel R. McKelvie National...

    Science.gov (United States)

    2010-05-14

    ... Geographic Area, Samuel R. McKelvie National Forest, Bessey Ranger District in Nebraska. The original notice... allotments within the McKelvie Geographic Area on the McKelvie National Forest and analyze continuation of... Forest Service McKelvie Geographic Area Range Allotment Management Planning on the Samuel R. McKelvie...

  8. Dynamic Range Size Analysis of Territorial Animals: An Optimality Approach.

    Science.gov (United States)

    Tao, Yun; Börger, Luca; Hastings, Alan

    2016-10-01

    Home range sizes of territorial animals are often observed to vary periodically in response to seasonal changes in foraging opportunities. Here we develop the first mechanistic model focused on the temporal dynamics of home range expansion and contraction in territorial animals. We demonstrate how simple movement principles can lead to a rich suite of range size dynamics, by balancing foraging activity with defensive requirements and incorporating optimal behavioral rules into mechanistic home range analysis. Our heuristic model predicts three general temporal patterns that have been observed in empirical studies across multiple taxa. First, a positive correlation between age and territory quality promotes shrinking home ranges over an individual's lifetime, with maximal range size variability shortly before the adult stage. Second, poor sensory information, low population density, and large resource heterogeneity may all independently facilitate range size instability. Finally, aggregation behavior toward forage-rich areas helps produce divergent home range responses between individuals from different age classes. This model has broad applications for addressing important unknowns in animal space use, with potential applications also in conservation and health management strategies.

  9. The effects of size and geographic focus on the relationships between manufacturing practices and performances

    DEFF Research Database (Denmark)

    Matyusz, Zsolt; Demeter, Krisztina; Boer, Harry

    2009-01-01

    Each company has to invest in manufacturing management programs, methods and technologies in order to remain competitive. Previous studies, however, rarely took into account how the size and geographical focus of a business unit affect the relationship between manufacturing practices and performa...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Adrián Naveda-Rodríguez

    Full Text Available 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.

  13. Indetermination of particle sizing by laser diffraction in the anomalous size ranges

    Science.gov (United States)

    Pan, Linchao; Ge, Baozhen; Zhang, Fugen

    2017-09-01

    The laser diffraction method is widely used to measure particle size distributions. It is generally accepted that the scattering angle becomes smaller and the angles to the location of the main peak of scattered energy distributions in laser diffraction instruments shift to smaller values with increasing particle size. This specific principle forms the foundation of the laser diffraction method. However, this principle is not entirely correct for non-absorbing particles in certain size ranges and these particle size ranges are called anomalous size ranges. Here, we derive the analytical formulae for the bounds of the anomalous size ranges and discuss the influence of the width of the size segments on the signature of the Mie scattering kernel. This anomalous signature of the Mie scattering kernel will result in an indetermination of the particle size distribution when measured by laser diffraction instruments in the anomalous size ranges. By using the singular-value decomposition method we interpret the mechanism of occurrence of this indetermination in detail and then validate its existence by using inversion simulations.

  14. Coopetition Effect Determinants: Competitor’s Size, Geographical Scope, Market and Technological Positions

    Directory of Open Access Journals (Sweden)

    Cygler Joanna

    2015-12-01

    Full Text Available Background and Goal: The article is aimed at conducting an empirical analysis of the value and significance of coopetitors’ attributes thanks to which coopetition, which is a combination of cooperation and competition between competitors, generates a substantial corporate profit. Four major competitors’ attributes have been analysed: its size, geographical scope, market and technological position. The research also includes the Porter’s value chain.

  15. Geographical Barriers and Dispersal Propensity Interact to Limit Range Expansions of Himalayan Birds.

    Science.gov (United States)

    White, Alexander E

    2016-07-01

    Range expansions are limited by two key factors. These are (1) dispersal, which includes a species' intrinsic mobility, geographical barriers, and their interaction; and (2) the ability of a species to persist beyond its current range. I evaluate the role of these in affecting bird species distributions across the Himalayas, under a hypothesis that many species have recently expanded their range out of an eastern Pleistocene refuge. I measured wing shape as a proxy for dispersal ability and topographic complexity across the Himalayas as a proxy for dispersal barriers. As a factor affecting the potential for persistence in novel locations, I compared similarity of a species' climatic envelope in the east, the hypothesized historical refuge, and the west, the location of recent colonization. Climatic similarity, wing shape, and the interaction of topographic complexity with wing shape all contribute significantly to the range extent of a given species. The result highlights the important interaction between morphological and landscape factors in affecting successful range expansions. The two dispersal-related parameters together explain two times the variance explained by climate, but I present additional evidence that other factors besides climate-notably biotic interactions-affect the ability of a species to persist beyond its range.

  16. Predictable variation of range-sizes across an extreme environmental gradient in a lizard adaptive radiation: evolutionary and ecological inferences.

    Directory of Open Access Journals (Sweden)

    Daniel Pincheira-Donoso

    Full Text Available Large-scale patterns of current species geographic range-size variation reflect historical dynamics of dispersal and provide insights into future consequences under changing environments. Evidence suggests that climate warming exerts major damage on high latitude and elevation organisms, where changes are more severe and available space to disperse tracking historical niches is more limited. Species with longer generations (slower adaptive responses, such as vertebrates, and with restricted distributions (lower genetic diversity, higher inbreeding in these environments are expected to be particularly threatened by warming crises. However, a well-known macroecological generalization (Rapoport's rule predicts that species range-sizes increase with increasing latitude-elevation, thus counterbalancing the impact of climate change. Here, I investigate geographic range-size variation across an extreme environmental gradient and as a function of body size, in the prominent Liolaemus lizard adaptive radiation. Conventional and phylogenetic analyses revealed that latitudinal (but not elevational ranges significantly decrease with increasing latitude-elevation, while body size was unrelated to range-size. Evolutionarily, these results are insightful as they suggest a link between spatial environmental gradients and range-size evolution. However, ecologically, these results suggest that Liolaemus might be increasingly threatened if, as predicted by theory, ranges retract and contract continuously under persisting climate warming, potentially increasing extinction risks at high latitudes and elevations.

  17. Impact of Size and Geographic Location on the Financial Condition of Spanish Municipalities

    Directory of Open Access Journals (Sweden)

    Roberto CABALEIRO CASAL

    2011-10-01

    Full Text Available In this study, the financial condition of Spanish municipalities is analyzed, due to its complex nature, through an integrated approach. In order to achieve that, the frameworks developed by the International City/County Management Association and the Canadian Institute of Chartered Accountants were taken as reference. Moreover, the authors used several indicators and a large sample of Spanish municipalities; the methodology used in the study objectifies the process of use of indicators. The study highlights the influence of population size and geographic location of local government on some dimensions of the financial condition of Spanish municipalities.

  18. Gene expression under thermal stress varies across a geographical range expansion front.

    Science.gov (United States)

    Lancaster, Lesley T; Dudaniec, Rachael Y; Chauhan, Pallavi; Wellenreuther, Maren; Svensson, Erik I; Hansson, Bengt

    2016-03-01

    Many ectothermic species are currently expanding their distributions polewards due to anthropogenic global warming. Molecular genetic mechanisms facilitating range expansion under these conditions are largely unknown, but understanding these could help mitigate expanding pests and disease vectors, or help explain why some species fail to track changing climates. Here, using RNA-seq data, we examine genomewide changes in gene expression under heat and cold stress in the range-expanding damselfly Ischnura elegans in northern Europe. We find that both the number of genes involved and levels of gene expression under heat stress have become attenuated during the expansion, consistent with a previously reported release from selection on heat tolerances as species move polewards. Genes upregulated under cold stress differed between core and edge populations, corroborating previously reported rapid adaptation to cooler climates at the expansion front. Expression of sixty-nine genes exhibited a region x treatment effect; these were primarily upregulated in response to heat stress in core populations but in response to cold stress at the range edge, suggesting that some cellular responses originally adapted to heat stress may switch to cold-stress functionality upon encountering novel thermal selection regimes during range expansion. Transcriptional responses to thermal stress involving heat-shock and neural function genes were largely geographically conserved, while retrotransposon, regulatory, muscle function and defence gene expression patterns were more variable. Flexible mechanisms of cold-stress response and the ability of some genes to shift their function between heat and cold stress might be key mechanisms facilitating rapid poleward expansion in insects.

  19. The current and future potential geographic range of West Indian fruit fly, Anastrepha obliqua (Diptera: Tephritidae).

    Science.gov (United States)

    Fu, Liao; Li, Zhi-Hong; Huang, Guan-Sheng; Wu, Xing-Xia; Ni, Wen-Long; Qü, Wei-Wei

    2014-04-01

    The West Indian fruit fly, Anastrepha obliqua (Macquart), is one of the most important pests throughout the Americas. CLIMEX 3.0 and ArcGIS 9.3 were used to model the current and future potential geographical distribution of this pest. Under current climatic conditions, A. obliqua is predicted to be able to establish throughout much of the tropics and subtropics, including not only North and South America, where it has been reported, but also southern Asia, northeastern Australia and Sub-Saharan Africa. The main factors limiting the pest's range expansion may be cold stress. Climate change expands the potential distribution of A. obliqua poleward as cold stress boundaries recede, but the predicted distribution in northwestern Australia and northern parts of Sub-Saharan Africa will decrease because of heat stress. Considering the widely suitable range for A. obliqua globally and in China, enhanced quarantine and monitoring measures should be implemented in areas that are projected to be suitable for the establishment of the pest under current and future climatic conditions. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  20. Geographical distribution of cytotypes in the Chrysanthemum indicum complex as evidenced by ploidy level and genome-size variation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Qian WAN; Richard J.ABBOTT; Guang-Yuan RAO

    2013-01-01

    A detailed knowledge of the geographical distribution ofcytotypes within and between species comprising a polyploid complex is critical to our understanding of the history and evolution of such complexes.In the present study we examined the geographical distributions ofcytotypes within six tentatively delimited species comprising the Chrysanthemum indicum complex in China.We determined the ploidy of 188 individuals sampled from 47 populations,based on DNA content using flow cytometry.In addition,chromosome counts were made on samples of each taxon.We confirmed that all samples of C.rhombifolium and C.lavandulifolium were diploid (2n =18),those of C.hypargyrum and C.potentilloides were tetraploid (2n--36),and those of C.vestitum were hexaploid (2n =54).In contrast,we confirmed that C.indicum contained both diploid and tetraploid cytotypes.We found that in addition to marked differences in genome size between ploidy levels,there was a variation in genome size between species of the same ploidy level.Although the diploid,tetraploid,and hexaploid taxa of the complex,as well as the diploid form of C.indicum,occurred only in central and northem China,the tetraploid form of C.indicum was widespread both north and south of the Yangtze River.We suggest that the tetraploid form of C.indicum may have expanded its range southward during recent Quatemary glacial periods when forests retreated in south China as conditions became drier.

  1. Leopard range size and conservation area size in the southern Kalahari

    Directory of Open Access Journals (Sweden)

    Jacobus du P. Bothma

    2012-01-01

    Full Text Available The range use patterns of adult leopards were used to examine the impact of environmental quality on conservation area size in the arid south-western portion of the Kgalagadi Transfrontier Park in southern Africa. The ranges of the leopards are the largest recorded in the world, with a mean size of 2104.4 km2 (SEM 995.95 km2 for males and 1258.5 km2 (SEM 541.50 km2 for females. Overlaps in range use within and between the sexes and the size of this conservation area make it possible to sustain a genetically viable population of leopards in this arid environment.Conservation implications: When establishing conservation areas that contain large carnivores in arid and semi-arid regions, prey abundance and range use should be considered for the area to be able to sustain viable populations of such carnivores. The results emphasise the importance of establishing large transfrontier conservation areas where individual conservation areas are too small to do so. This study is the first to do so for leopards in southern Africa.

  2. Geographical and temporal body size variation in a reptile: roles of sex, ecology, phylogeny and ecology structured in phylogeny.

    Directory of Open Access Journals (Sweden)

    Pedro Aragón

    Full Text Available Geographical body size variation has long interested evolutionary biologists, and a range of mechanisms have been proposed to explain the observed patterns. It is considered to be more puzzling in ectotherms than in endotherms, and integrative approaches are necessary for testing non-exclusive alternative mechanisms. Using lacertid lizards as a model, we adopted an integrative approach, testing different hypotheses for both sexes while incorporating temporal, spatial, and phylogenetic autocorrelation at the individual level. We used data on the Spanish Sand Racer species group from a field survey to disentangle different sources of body size variation through environmental and individual genetic data, while accounting for temporal and spatial autocorrelation. A variation partitioning method was applied to separate independent and shared components of ecology and phylogeny, and estimated their significance. Then, we fed-back our models by controlling for relevant independent components. The pattern was consistent with the geographical Bergmann's cline and the experimental temperature-size rule: adults were larger at lower temperatures (and/or higher elevations. This result was confirmed with additional multi-year independent data-set derived from the literature. Variation partitioning showed no sex differences in phylogenetic inertia but showed sex differences in the independent component of ecology; primarily due to growth differences. Interestingly, only after controlling for independent components did primary productivity also emerge as an important predictor explaining size variation in both sexes. This study highlights the importance of integrating individual-based genetic information, relevant ecological parameters, and temporal and spatial autocorrelation in sex-specific models to detect potentially important hidden effects. Our individual-based approach devoted to extract and control for independent components was useful to reveal hidden

  3. Feasibility of Close-Range Photogrammetric Models for Geographic Information System

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Luke; /Rice U.

    2011-06-22

    The objective of this project was to determine the feasibility of using close-range architectural photogrammetry as an alternative three dimensional modeling technique in order to place the digital models in a geographic information system (GIS) at SLAC. With the available equipment and Australis photogrammetry software, the creation of full and accurate models of an example building, Building 281 on SLAC campus, was attempted. After conducting several equipment tests to determine the precision achievable, a complete photogrammetric survey was attempted. The dimensions of the resulting models were then compared against the true dimensions of the building. A complete building model was not evidenced to be obtainable using the current equipment and software. This failure was likely attributable to the limits of the software rather than the precision of the physical equipment. However, partial models of the building were shown to be accurate and determined to still be usable in a GIS. With further development of the photogrammetric software and survey procedure, the desired generation of a complete three dimensional model is likely still feasible.

  4. Speciation and extinction drive the appearance of directional range size evolution in phylogenies and the fossil record.

    Directory of Open Access Journals (Sweden)

    Alex L Pigot

    Full Text Available While the geographic range of a species is a fundamental unit of macroecology and a leading predictor of extinction risk, the evolutionary dynamics of species' ranges remain poorly understood. Based on statistical associations between range size and species age, many studies have claimed support for general models of range evolution in which the area occupied by a species varies predictably over the course of its life. Such claims have been made using both paleontological data and molecular estimates of the age of extant species. However, using a stochastic model, we show that the appearance of trends in range size with species' age can arise even when range sizes have evolved at random through time. This occurs because the samples of species used in existing studies are likely to be biased with respect to range size: for example, only those species that happened to have large or expanding ranges are likely to survive to the present, while extinct species will tend to be those whose ranges, by chance, declined through time. We compared the relationship between the age and range size of species arising under our stochastic model to those observed across 1,269 species of extant birds and mammals and 140 species of extinct Cenozoic marine mollusks. We find that the stochastic model is able to generate the full spectrum of empirical age-area relationships, implying that such trends cannot be simply interpreted as evidence for models of directional range size evolution. Our results therefore challenge the theory that species undergo predictable phases of geographic expansion and contraction through time.

  5. Speciation and Extinction Drive the Appearance of Directional Range Size Evolution in Phylogenies and the Fossil Record

    Science.gov (United States)

    Pigot, Alex L.; Owens, Ian P. F.; Orme, C. David L.

    2012-01-01

    While the geographic range of a species is a fundamental unit of macroecology and a leading predictor of extinction risk, the evolutionary dynamics of species' ranges remain poorly understood. Based on statistical associations between range size and species age, many studies have claimed support for general models of range evolution in which the area occupied by a species varies predictably over the course of its life. Such claims have been made using both paleontological data and molecular estimates of the age of extant species. However, using a stochastic model, we show that the appearance of trends in range size with species' age can arise even when range sizes have evolved at random through time. This occurs because the samples of species used in existing studies are likely to be biased with respect to range size: for example, only those species that happened to have large or expanding ranges are likely to survive to the present, while extinct species will tend to be those whose ranges, by chance, declined through time. We compared the relationship between the age and range size of species arising under our stochastic model to those observed across 1,269 species of extant birds and mammals and 140 species of extinct Cenozoic marine mollusks. We find that the stochastic model is able to generate the full spectrum of empirical age–area relationships, implying that such trends cannot be simply interpreted as evidence for models of directional range size evolution. Our results therefore challenge the theory that species undergo predictable phases of geographic expansion and contraction through time. PMID:22371689

  6. Where do species' geographic ranges stop and why? Landscape impermeability and the Afrotropical avifauna.

    Science.gov (United States)

    McInnes, Lynsey; Purvis, Andy; Orme, C David L

    2009-09-07

    Although understanding large-scale spatial variation in species' distributions is a major goal in macroecology, relatively little attention has been paid to the factors limiting species' ranges. An understanding of these factors may improve predictions of species' movements in response to global change. We present a measure of landscape impermeability, defined as the proportion of resident species whose ranges end in an area. We quantify and map impermeability for Afrotropical birds and use multi-model inference to assess support for a wide suite of hypotheses about its potential environmental correlates. Non-spatial analyses emphasize the importance of broad-scale environmental patterns of energy availability and habitat heterogeneity in limiting species' distributions. Conversely, spatial analyses focus attention on small-scale factors of habitat and topographic complexity. These results hold even when only species from the top quartile of range sizes are assessed. All our analyses highlight that range edges are concentrated in heterogeneous habitats. Global change is expected to alter the nature and distribution of such habitats, necessitating range movement by many resident species. Therefore, impermeability provides a simple measure for identifying regions, where continuing global change and human encroachment are likely to cause profound changes in regional diversity patterns.

  7. A Diverse Range of Novel RNA Viruses in Geographically Distinct Honey Bee Populations.

    Science.gov (United States)

    Remnant, Emily J; Shi, Mang; Buchmann, Gabriele; Blacquière, Tjeerd; Holmes, Edward C; Beekman, Madeleine; Ashe, Alyson

    2017-08-15

    high levels of picornaviruses. To examine the underlying viral diversity in honey bees, we employed viral metatranscriptomics analyses on three geographically diverse Varroa-resistant populations from Europe, Africa, and the Pacific. We describe seven novel viruses from a range of diverse viral families, including two viruses that are present in all three locations. In honey bees, small RNA sequences indicate that these viruses are processed by Dicer and the RNA interference pathway, whereas Varroa mites produce strikingly novel small RNA patterns. This work increases the number and diversity of known honey bee viruses and will ultimately contribute to improved disease management in our most important agricultural pollinator. Copyright © 2017 Remnant et al.

  8. National Geographic FieldScope: Tools for Engaging a Range of Audiences in Citizen Science

    Science.gov (United States)

    OConnor, S.; Takaki, E.

    2013-12-01

    Recognizing the promise of projects that engage non-scientists in scientific research as a context for informal science learning, National Geographic set out in 2009 to develop a technology infrastructure to support public participation in scientific research (PPSR), or citizen science, projects. As a result, NG has developed a web-based platform called FieldScope to host projects in which geographically distributed participants submit local observations or measurements to a shared database. This project is motivated by the observation that historically citizen science initiatives have been siloed using different technologies, and that these projects rarely provide participants with the opportunity to participate in data analysis or any other aspects of the scientific process except for collecting and contributing data. Therefore, FieldScope has been designed to support data visualization and analysis using geospatial technologies and aims to develop social networking tools for communicating and discussing findings. Since educational impact is the project's primary priority, FieldScope is also being designed with usability by novices in mind. In addition to engaging novices in participation in citizen science, the design of the application is also meant to engage students and others in working with geospatial technologies, in this case, web-based GIS. The project's goal is to create a single, powerful infrastructure for PPSR projects that any organization can use to create their own project and support their own community of participants. The FieldScope environment will serve as a hosting environment for PPSR projects following the model of hosted communities of practice that has become widespread on the web. The goal is to make FieldScope a publicly-available resource for any PPSR project on a no- or low-cost basis. It will also make synergies possible between projects that are collecting related data in the same geographic area. NG is now in the fourth year of an

  9. Geographic range did not confer resilience to extinction in terrestrial vertebrates at the end-Triassic crisis.

    Science.gov (United States)

    Dunhill, Alexander M; Wills, Matthew A

    2015-08-11

    Rates of extinction vary greatly through geological time, with losses particularly concentrated in mass extinctions. Species duration at other times varies greatly, but the reasons for this are unclear. Geographical range correlates with lineage duration amongst marine invertebrates, but it is less clear how far this generality extends to other groups in other habitats. It is also unclear whether a wide geographical distribution makes groups more likely to survive mass extinctions. Here we test for extinction selectivity amongst terrestrial vertebrates across the end-Triassic event. We demonstrate that terrestrial vertebrate clades with larger geographical ranges were more resilient to extinction than those with smaller ranges throughout the Triassic and Jurassic. However, this relationship weakened with increasing proximity to the end-Triassic mass extinction, breaking down altogether across the event itself. We demonstrate that these findings are not a function of sampling biases; a perennial issue in studies of this kind.

  10. Assessing ecological specialization of an ant-seed dispersal mutualism through a wide geographic range.

    Science.gov (United States)

    Manzaneda, Antonio J; Rey, Pedro J

    2009-11-01

    Specialization in species interactions is of central importance for understanding the ecological structure and evolution of plant-animal mutualisms. Most plant-animal mutualisms are facultative and strongly asymmetric. In particular, myrmecochory (seed dispersal by ants) has been regarded as a very generalized interaction. Although some recent studies have suggested that only a few ant species are really important for dispersal, no rigorous measurement of the specialization in ant-seed dispersal mutualisms has been performed. Here, we use individual plants as basic units for replication to investigate the generalization-specialization of the herb Helleborus foetidus on its ant dispersers over a considerable part of its geographical range. We define generalization in terms of diversity components (species richness and evenness) of the ant visitor that realizes dispersal by removing diaspores. We obtain truly comparable values of ant visitor diversity, distinguishing among different functional groups of visitors and identifying incidental visitors and real ant dispersers. Using null model approaches, we test the null hypothesis that ant-mediated dispersal is a generalized mutualism. At least two premises should be confirmed to validate the hypothesis: (1) diaspores are dispersed by multiple ant-visitor species, and (2) diaspore dispersal is significantly equitable. Though up to 37 ant species visited diaspores across 10 populations, only two large formicines, Camponotus cruentatus and Formica lugubris, were responsible for the vast majority of visits resulting in dispersal in most populations and years, which strongly suggests that ant seed dispersal in H. foetidus is ecologically specialized. Interestingly, specialization degree was unrelated to dispersal success across populations. Our study offers new insights into the spatiotemporal dynamics of myrmecochory. We propose the existence of an alternative scenario to extensive generalization. In this new scenario

  11. Is the Geographic Range of Mangrove Forests in the Conterminous United States Really Expanding?

    Directory of Open Access Journals (Sweden)

    Chandra Giri

    2016-11-01

    Full Text Available Changes in the distribution and abundance of mangrove species within and outside of their historic geographic range can have profound consequences in the provision of ecosystem goods and services they provide. Mangroves in the conterminous United States (CONUS are believed to be expanding poleward (north due to decreases in the frequency and severity of extreme cold events, while sea level rise is a factor often implicated in the landward expansion of mangroves locally. We used ~35 years of satellite imagery and in situ observations for CONUS and report that: (i poleward expansion of mangrove forest is inconclusive, and may have stalled for now, and (ii landward expansion is actively occurring within the historical northernmost limit. We revealed that the northernmost latitudinal limit of mangrove forests along the east and west coasts of Florida, in addition to Louisiana and Texas has not systematically expanded toward the pole. Mangrove area, however, expanded by 4.3% from 1980 to 2015 within the historic northernmost boundary, with the highest percentage of change in Texas and southern Florida. Several confounding factors such as sea level rise, absence or presence of sub-freezing temperatures, land use change, impoundment/dredging, changing hydrology, fire, storm, sedimentation and erosion, and mangrove planting are responsible for the change. Besides, sea level rise, relatively milder winters and the absence of sub-freezing temperatures in recent decades may be enabling the expansion locally. The results highlight the complex set of forcings acting on the northerly extent of mangroves and emphasize the need for long-term monitoring as this system increases in importance as a means to adapt to rising oceans and mitigate the effects of increased atmospheric CO2.

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

    Science.gov (United States)

    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

  13. Correlates of research effort in carnivores: body size, range size and diet matter.

    Directory of Open Access Journals (Sweden)

    Zoe M Brooke

    Full Text Available Given the budgetary restrictions on scientific research and the increasing need to better inform conservation actions, it is important to identify the patterns and causes of biases in research effort. We combine bibliometric information from a literature review of almost 16,500 peer-reviewed publications on a well-known group of 286 species, the Order Carnivora, with global datasets on species' life history and ecological traits to explore patterns in research effort. Our study explores how species' characteristics influenced the degree to which they were studied (measured as the number of publications. We identified a wide variation in intensity of research effort at both Family and Species levels, with some of the least studied being those which may need protection in future. Our findings hint at the complex role of human perspectives in setting research agendas. We found that better-studied species tended to be large-bodied and have a large geographic range whilst omnivory had a negative relationship with research effort. IUCN threat status did not exhibit a strong relationship with research effort which suggests that the conservation needs of individual species are not major drivers of research interest. This work is the first to use a combination of bibliometric analysis and biological data to quantify and interpret gaps in research knowledge across an entire Order. Our results could be combined with other resources, such as Biodiversity Action Plans, to prioritise and co-ordinate future research effort, whilst our methods can be applied across many scientific disciplines to describe knowledge gaps.

  14. The Eocene Arctic Azolla phenomenon: species composition, temporal range and geographic extent.

    Science.gov (United States)

    Collinson, Margaret; Barke, Judith; van der Burgh, Johan; van Konijnenburg-van Cittert, Johanna; Pearce, Martin; Bujak, Jonathan; Brinkhuis, Henk

    2010-05-01

    Azolla is a free-floating freshwater fern that is renowned for its rapid vegetative spread and invasive biology, being one of the world's fastest growing aquatic macrophytes. Two species of this plant have been shown to have bloomed and reproduced in enormous numbers in the latest Early to earliest Middle Eocene of the Arctic Ocean and North Sea based on samples from IODP cores from the Lomonosov Ridge (Arctic) and from outcrops in Denmark (Collinson et al 2009 a,b Review of Palaeobotany and Palynology 155,1-14; and doi:10.1016/j.revpalbo.2009.12.001). To determine the geographic and temporal extent of this Azolla phenomenon, and the spatial distribution of the different species, we have examined samples from 15 additional sites using material from ODP cores and commercial exploration wells. The sites range from the Sub-Arctic (Northern Alaska and Canadian Beaufort Mackenzie Basin) to the Nordic Seas (Norwegian-Greenland Sea and North Sea Basin). Our data show that the Azolla phenomenon involved at least three species. These are distinguished by characters of the megaspore apparatus (e.g. megaspore wall, floats, filosum) and the microspore massulae (e.g. glochidia fluke tips). The Lomonosov Ridge (Arctic) and Danish occurrences are monotypic but in other sites more than one species co-existed. The attachment to one another and the co-occurrence of megaspore apparatus and microspore massulae, combined with evidence that these spores were shed at the fully mature stage of their life cycle, shows that the Azolla remains were not transported over long distances, a fact which could not be assumed from isolated massula fragments alone. Our evidence, therefore, shows that Azolla plants grew on the ocean surfaces for approximately 1.2 million years (from 49.3 to 48.1 Ma) and that the Azolla phenomenon covered the area from Denmark northwards across the North Sea Basin and the whole of the Arctic and Nordic seas. Apparently, early Middle Eocene Northern Hemisphere middle

  15. Abundance-range size relationships in stream vegetation in Denmark

    DEFF Research Database (Denmark)

    Riis, Tenna; Sand-Jensen, Kaj

    2002-01-01

    such asobligatory submerged or amphibious species. The amphibious species, which caneasily disperse by seeds between stream systems and by vegetative growth frompermanent bank populations to the open streambed, had a significantly strongerabundance-range relationship than obligatory submerged species probably due......Streams experience a constant redistribution of species and in-streamplant stands due to the extensive disturbance caused by flow variation, highcontinuity of habitats and efficient dispersal in the stream network. Theseconditions increase the homogeneity of environmental conditions...... tomore effective dispersal. The importance of metapopulation dynamics was alsosupported by the fact that species in seven of the ten stream systems withmultiple localities showed a stronger positive relationship than the overallrelationship for all streams, while the relationship for distinct...

  16. Size and shape variability in the skull of Myotis nigricans (Schinz, 1821 (Chiroptera: Vespertilionidae from two geographic areas in Brazil

    Directory of Open Access Journals (Sweden)

    R. Bornholdt

    Full Text Available We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821 assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

  17. Home is where the shell is: predicting turtle home range sizes.

    Science.gov (United States)

    Slavenko, Alex; Itescu, Yuval; Ihlow, Flora; Meiri, Shai

    2016-01-01

    Home range is the area traversed by an animal in its normal activities. The size of home ranges is thought to be tightly linked to body size, through size effect on metabolic requirements. Due to the structure of Eltonian food pyramids, home range sizes of carnivores are expected to exceed those of herbivorous species. The habitat may also affect home range size, with reduced costs of locomotion or lower food abundance in, for example, aquatic habitats selecting for larger home ranges. Furthermore, home range of males in polygamous species may be large due to sexual selection for increased reproductive output. Comparative studies on home range sizes have rarely been conducted on ectotherms. Because ectotherm metabolic rates are much lower than those of endotherms, energetic considerations of metabolic requirements may be less important in determining the home range sizes of the former, and other factors such as differing habitats and sexual selection may have an increased effect. We collected literature data on turtle home range sizes. We used phylogenetic generalized least squares analyses to determine whether body mass, sex, diet, habitat and social structure affect home range size. Turtle home range size increases with body mass. However, body mass explains relatively little of the variation in home range size. Aquatic turtles have larger home ranges than semiaquatic species. Omnivorous turtles have larger home ranges than herbivores and carnivores, but diet is not a strong predictor. Sex and social structure are unrelated to home range size. We conclude that energetic constraints are not the primary factor that determines home range size in turtles, and energetic costs of locomotion in different habitats probably play a major role. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  18. Biofouling community composition across a range of environmental conditions and geographical locations suitable for floating marine renewable energy generation.

    Science.gov (United States)

    Macleod, Adrian K; Stanley, Michele S; Day, John G; Cook, Elizabeth J

    2016-01-01

    Knowledge of biofouling typical of marine structures is essential for engineers to define appropriate loading criteria in addition to informing other stakeholders about the ecological implications of creating novel artificial environments. There is a lack of information regarding biofouling community composition (including weight and density characteristics) on floating structures associated with future marine renewable energy generation technologies. A network of navigation buoys were identified across a range of geographical areas, environmental conditions (tidal flow speed, temperature and salinity), and deployment durations suitable for future developments. Despite the perceived importance of environmental and temporal factors, geographical location explained the greatest proportion of the observed variation in community composition, emphasising the importance of considering geography when assessing the impact of biofouling on device functioning and associated ecology. The principal taxa associated with variation in biofouling community composition were mussels (Mytilus edulis), which were also important when determining loading criteria.

  19. Conservation Concern for the Deteriorating Geographical Range of the Grey Parrot in Cameroon

    Directory of Open Access Journals (Sweden)

    Simon A. Tamungang

    2014-01-01

    Full Text Available The need for information on Grey Parrot distribution and vegetation associations for informed management and policy decisions was the basis for this study. A nationwide survey of the Grey Parrot population and habitat status was carried out, using questionnaire and point count methods. From the results, the extent of the contemporary range of the parrots was restricted to Southern Cameroon, which harbours the rainforest. Regional parrot population means ranged from 3,487 parrots in the Littoral to 1,351,275 parrots in the East Regions. The extent of the contemporary range as a percentage of the whole country was 25.4% and as a percentage of the regions with rainforest was 44.5%. The historic range of the bird has been reduced by over 55.5%. Estimated percentage of forest lost per region ranged from 20.4% in the Centre to 57.1% in the East and South Regions. At a global level, Cameroon contributed 9% to the total extent of the range of the Grey Parrot in Africa. The range is increasingly fragmented, contracted, and lost through land-based socioeconomic activities. These degradation pressures on the range called for urgent conservation considerations for long-term survival of the parrot species and its associated biodiversity in Cameroon.

  20. Microbial composition of spiny ants (Hymenoptera: Formicidae: Polyrhachis) across their geographic range.

    Science.gov (United States)

    Ramalho, Manuela Oliveira; Bueno, Odair Correa; Moreau, Corrie Saux

    2017-04-05

    Symbiotic relationships between insects and bacteria are found across almost all insect orders, including Hymenoptera. However there are still many remaining questions about these associations including what factors drive host-associated bacterial composition. To better understand the evolutionary significance of this association in nature, further studies addressing a diversity of hosts across locations and evolutionary history are necessary. Ants of the genus Polyrhachis (spiny ants) are distributed across the Old World and exhibit generalist diets and habits. Using Next Generation Sequencing (NGS) and bioinformatics tools, this study explores the microbial community of >80 species of Polyrhachis distributed across the Old World and compares the microbiota of samples and related hosts across different biogeographic locations and in the context of their phylogenetic history. The predominant bacteria across samples were Enterobacteriaceae (Blochmannia - with likely many new strains), followed by Wolbachia (with multiple strains), Lactobacillus, Thiotrichaceae, Acinetobacter, Nocardia, Sodalis, and others. We recovered some exclusive strains of Enterobacteriaceae as specific to some subgenera of Polyrhachis, corroborating the idea of coevolution between host and bacteria for this bacterial group. Our correlation results (partial mantel and mantel tests) found that host phylogeny can influence the overall bacterial community, but that geographic location had no effect. Our work is revealing important aspects of the biology of hosts in structuring the diversity and abundance of these host-associated bacterial communities including the role of host phylogeny and shared evolutionary history.

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

    Science.gov (United States)

    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. Temporal and geographic clustering of polyomavirus-associated olfactory tumors in 10 free-ranging raccoons (Procyon lotor).

    Science.gov (United States)

    Giannitti, F; Higgins, R J; Pesavento, P A; Dela Cruz, F; Clifford, D L; Piazza, M; Parker Struckhoff, A; Del Valle, L; Bollen, A W; Puschner, B; Kerr, E; Gelberg, H; Mete, A; McGraw, S; Woods, L W

    2014-07-01

    Reports of primary nervous system tumors in wild raccoons are extremely rare. Olfactory tumors were diagnosed postmortem in 9 free-ranging raccoons from 4 contiguous counties in California and 1 raccoon from Oregon within a 26-month period between 2010 and 2012. We describe the geographic and temporal features of these 10 cases, including the laboratory diagnostic investigations and the neuropathologic, immunohistochemical, and ultrastructural characteristics of these tumors in the affected animals. All 9 raccoons from California were found within a localized geographic region of the San Francisco Bay Area (within a 44.13-km radius). The tight temporal and geographic clustering and consistent anatomic location in the olfactory system of tumor types not previously described in raccoons (malignant peripheral nerve sheath tumors and undifferentiated sarcomas) strongly suggest either a common cause or a precipitating factor leading to induction or potentiation of neuro-oncogenesis and so prompted an extensive diagnostic investigation to explore possible oncogenic infectious and/or toxic causes. By a consensus polymerase chain reaction strategy, a novel, recently reported polyomavirus called raccoon polyomavirus was identified in all 10 tumors but not in the normal brain tissue from the affected animals, suggesting that the virus might play a role in neuro-oncogenesis. In addition, expression of the viral protein T antigen was detected in all tumors containing the viral sequences. We discuss the potential role of raccoon polyomavirus as an oncogenic virus. © The Author(s) 2013.

  3. Environmental versus geographical effects on genomic variation in wild soybean (Glycine soja) across its native range in northeast Asia.

    Science.gov (United States)

    Leamy, Larry J; Lee, Cheng-Ruei; Song, Qijian; Mujacic, Ibro; Luo, Yan; Chen, Charles Y; Li, Changbao; Kjemtrup, Susanne; Song, Bao-Hua

    2016-09-01

    A fundamental goal in evolutionary biology is to understand how various evolutionary factors interact to affect the population structure of diverse species, especially those of ecological and/or agricultural importance such as wild soybean (Glycine soja). G. soja, from which domesticated soybeans (Glycine max) were derived, is widely distributed throughout diverse habitats in East Asia (Russia, Japan, Korea, and China). Here, we utilize over 39,000 single nucleotide polymorphisms genotyped in 99 ecotypes of wild soybean sampled across their native geographic range in northeast Asia, to understand population structure and the relative contribution of environment versus geography to population differentiation in this species. A STRUCTURE analysis identified four genetic groups that largely corresponded to the geographic regions of central China, northern China, Korea, and Japan, with high levels of admixture between genetic groups. A canonical correlation and redundancy analysis showed that environmental factors contributed 23.6% to population differentiation, much more than that for geographic factors (6.6%). Precipitation variables largely explained divergence of the groups along longitudinal axes, whereas temperature variables contributed more to latitudinal divergence. This study provides a foundation for further understanding of the genetic basis of climatic adaptation in this ecologically and agriculturally important species.

  4. A framework for examining climate-driven changes to the seasonality and geographical range of coastal pathogens and harmful algae

    Directory of Open Access Journals (Sweden)

    John Jacobs

    2015-01-01

    Full Text Available Climate change is expected to alter coastal ecosystems in ways which may have predictable consequences for the seasonality and geographical distribution of human pathogens and harmful algae. Here we demonstrate relatively simple approaches for evaluating the risk of occurrence of pathogenic bacteria in the genus Vibrio and outbreaks of toxin-producing harmful algae in the genus Alexandrium, with estimates of uncertainty, in U.S. coastal waters under future climate change scenarios through the end of the 21st century. One approach forces empirical models of growth, abundance and the probability of occurrence of the pathogens and algae at specific locations in the Chesapeake Bay and Puget Sound with ensembles of statistically downscaled climate model projections to produce first order assessments of changes in seasonality. In all of the case studies examined, the seasonal window of occurrence for Vibrio and Alexandrium broadened, indicating longer annual periods of time when there is increased risk for outbreaks. A second approach uses climate model projections coupled with GIS to identify the potential for geographic range shifts for Vibrio spp. in the coastal waters of Alaska. These two approaches could be applied to other coastal pathogens that have climate sensitive drivers to investigate potential changes to the risk of outbreaks in both time (seasonality and space (geographical distribution under future climate change scenarios.

  5. Limited phenotypic plasticity in range-edge populations: a comparison of co-occurring populations of two Agrimonia species with different geographical distributions.

    Science.gov (United States)

    Mägi, Maris; Semchenko, Marina; Kalamees, Reïn; Zobel, Kristjan

    2011-01-01

    Increased importance of genetic drift and selection for stress resistance have been predicted to lead to a reduction in the degree of phenotypic plasticity in populations at margins of a species' geographical range, relative to those in the centre. We examined the effect of population positioning within the species range on degree of active morphological plasticity to vegetation shade. Importantly, we discriminated between active, size-independent morphological adjustments in response to shade and passive changes in morphology caused by the dependence of morphological traits on plant size, as only the former are considered to be adaptive. Two closely related and ecologically similar Agrimonia species were examined in the same geographical location, where one species reaches the edge of its distribution (Agrimonia pilosa) and the other does not (A. eupatoria). Plasticity to light availability is likely to be advantageous for both species as they occupy habitats with variable light conditions. However, we hypothesised that high levels of environmental stress should lead to reduced active plasticity in marginal compared with more central populations. Agrimonia eupatoria exhibited active adjustments in leaf morphology in response to tree shade, and in elongation of stems and inflorescences in response to herbaceous shade. In contrast, A. pilosa exhibited very limited active plasticity. High active plasticity allowed A. eupatoria to retain constant shoot growth in a wide range of light conditions, while the lack of active plasticity in A. pilosa resulted in a strong dependence of shoot growth on light availability. We propose that high levels of environmental stress in marginal areas of a species' range may lead to a significant reduction in the degree of active plasticity. Our results clearly indicate that discrimination between active and passive plasticity is crucial for reaching valid conclusions about differences in adaptive plasticity between marginal and non

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

    Science.gov (United States)

    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

  7. Consistency in fruit preferences across the geographical range of the frugivorous bats Artibeus , Carollia and Sturnira (Chiroptera

    Directory of Open Access Journals (Sweden)

    Lays C. Parolin

    2016-01-01

    Full Text Available Abstract The frugivorous phyllostomid bat genera Artibeus , Carollia and Sturnira are important seed dispersers in the Neotropics, and exhibit supposed preferences for fruits of the genus Ficus , Piper and Solanum , respectively. We performed a quantified literature review to test the hypothesis that interactions with plants are consistent throughout the bats´ geographic ranges. Through an extensive literature review we obtained a total of 4,448 records of fruit consumption from 180 publications. To test which fruits were most frequently consumed across the Neotropical region and in each of its component countries these data were organized by bat species and country. In general, considering the 176 botanical genera eaten by these bats, the results showed a high consumption frequency of Ficus (24.0% by Artibeus , Piper (38.7% by Carollia and Solanum (31.0% by Sturnira . Additionally, our findings support the hypothesis of diet consistency throughout the geographic range of these genera. We suggest that this consistency is related to the wide distribution of the study groups (both bats and plants, the phenology of the zoochoric species consumed, the spatial fidelity of bats and the foraging patterns of the different bat species.

  8. Phylogenetic fields through time: temporal dynamics of geographical co-occurrence and phylogenetic structure within species ranges.

    Science.gov (United States)

    Villalobos, Fabricio; Carotenuto, Francesco; Raia, Pasquale; Diniz-Filho, José Alexandre F

    2016-04-05

    Species co-occur with different sets of other species across their geographical distribution, which can be either closely or distantly related. Such co-occurrence patterns and their phylogenetic structure within individual species ranges represent what we call the species phylogenetic fields (PFs). These PFs allow investigation of the role of historical processes--speciation, extinction and dispersal--in shaping species co-occurrence patterns, in both extinct and extant species. Here, we investigate PFs of large mammalian species during the last 3 Myr, and how these correlate with trends in diversification rates. Using the fossil record, we evaluate species' distributional and co-occurrence patterns along with their phylogenetic structure. We apply a novel Bayesian framework on fossil occurrences to estimate diversification rates through time. Our findings highlight the effect of evolutionary processes and past climatic changes on species' distributions and co-occurrences. From the Late Pliocene to the Recent, mammal species seem to have responded in an individualistic manner to climate changes and diversification dynamics, co-occurring with different sets of species from different lineages across their geographical ranges. These findings stress the difficulty of forecasting potential effects of future climate changes on biodiversity.

  9. Geographical variation in body size and sexual size dimorphism in an Australian lizard, Boulenger's Skink (Morethia boulengeri).

    Science.gov (United States)

    Michael, Damian R; Banks, Sam C; Piggott, Maxine P; Cunningham, Ross B; Crane, Mason; MacGregor, Christopher; McBurney, Lachlan; Lindenmayer, David B

    2014-01-01

    Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation in an Australian lizard, Boulenger's Skink Morethia boulengeri from agricultural landscapes in southern New South Wales, south-eastern Australia. We collected tissue and morphological data on 337 adult lizards across a broad elevation and climate gradient. We used a model-selection procedure to determine if environmental or ecological variables best explained body size variation. We explored the relationship between morphology and phylogenetic structure before modeling candidate variables from four broad domains: (1) geography (latitude, longitude and elevation), (2) climate (temperature and rainfall), (3) habitat (vegetation type, number of logs and ground cover attributes), and (4) management (land use and grazing history). Broad phylogenetic structure was evident, but on a scale larger than our study area. Lizards were sexually dimorphic, whereby females had longer snout-vent length than males, providing support for the fecundity selection hypothesis. Body size variation in M. boulengeri was correlated with temperature and rainfall, a pattern consistent with larger individuals occupying cooler and more productive parts of the landscape. Climate change forecasts, which predict warmer temperature and increased aridity, may result in reduced lizard biomass and decoupling of trophic interactions with potential implications for community organization and ecosystem function.

  10. Long-range wireless mesh network for weather monitoring in unfriendly geographic conditions.

    Science.gov (United States)

    Toledano-Ayala, Manuel; Herrera-Ruiz, Gilberto; Soto-Zarazúa, Genaro M; Rivas-Araiza, Edgar A; Bazán Trujillo, Rey D; Porrás-Trejo, Rafael E

    2011-01-01

    In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs), Base Terminal Units (BTUs) and a Central Server (CS). The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal.

  11. Long-Range Wireless Mesh Network for Weather Monitoring in Unfriendly Geographic Conditions

    Directory of Open Access Journals (Sweden)

    Rafael E. Porrás-Trejo

    2011-07-01

    Full Text Available In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs, Base Terminal Units (BTUs and a Central Server (CS. The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal.

  12. Dynamic occupancy models for analyzing species' range dynamics across large geographic scales

    Science.gov (United States)

    Bled, Florent; Nichols, James D; Altwegg, Res

    2013-01-01

    Large-scale biodiversity data are needed to predict species' responses to global change and to address basic questions in macroecology. While such data are increasingly becoming available, their analysis is challenging because of the typically large heterogeneity in spatial sampling intensity and the need to account for observation processes. Two further challenges are accounting for spatial effects that are not explained by covariates, and drawing inference on dynamics at these large spatial scales. We developed dynamic occupancy models to analyze large-scale atlas data. In addition to occupancy, these models estimate local colonization and persistence probabilities. We accounted for spatial autocorrelation using conditional autoregressive models and autologistic models. We fitted the models to detection/nondetection data collected on a quarter-degree grid across southern Africa during two atlas projects, using the hadeda ibis (Bostrychia hagedash) as an example. The model accurately reproduced the range expansion between the first (SABAP1: 1987–1992) and second (SABAP2: 2007–2012) Southern African Bird Atlas Project into the drier parts of interior South Africa. Grid cells occupied during SABAP1 generally remained occupied, but colonization of unoccupied grid cells was strongly dependent on the number of occupied grid cells in the neighborhood. The detection probability strongly varied across space due to variation in effort, observer identity, seasonality, and unexplained spatial effects. We present a flexible hierarchical approach for analyzing grid-based atlas data using dynamical occupancy models. Our model is similar to a species' distribution model obtained using generalized additive models but has a number of advantages. Our model accounts for the heterogeneous sampling process, spatial correlation, and perhaps most importantly, allows us to examine dynamic aspects of species ranges. PMID:24455124

  13. Home range sizes for burchell's zebra equus burchelli antiquorum from the Kruger National Park

    Directory of Open Access Journals (Sweden)

    G.L. Smuts

    1975-07-01

    Full Text Available Annual home range sizes were determined for 49 marked zebra family groups in the Kruger National Park. Sizes varied from 49 to 566 sq. km, the mean for the Park being 164 square kilometre. Mean home range sizes for different zebra sub-populations and biotic areas were found to differ considerably. Present herbivore densities have not influenced intra- and inter-specific tolerance levels to the extent that home range sizes have increased. Local habitat conditions, and particularly seasonal vegetational changes, were found to have the most profound influence on the shape and mean size of home ranges. The large home range sizes obtained in the Kruger Park, when compared to an area such as the Ngorongoro Crater, can be ascribed to a lower carrying capacity with respect to zebra, large portions of the habitat being sub-optimal, either seasonally or annually.

  14. Determining Home Range and Preferred Habitat of Feral Horses on the Nevada National Security Site Using Geographic Information Systems

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Ashley V. [Univ. of Denver, CO (United States)

    2014-05-30

    Feral horses (Equus caballus) are free-roaming descendants of domesticated horses and legally protected by the Wild and Free-Roaming Horses and Burros Act of 1971, which mandates how feral horses and burros should be managed and protected on federal lands. Using a geographic information system to determine the home range and suitable habitat of feral horses on the federally managed Nevada National Security Site can enable wildlife biologists in making best management practice recommendations. Home range was estimated at 88.1 square kilometers. Site suitability was calculated for elevation, forage, slope, water presence and horse observations. These variables were combined in successive iterations into one polygon. Suitability rankings established that 85 square kilometers are most suitable habitat, with 2,052 square kilometers of good habitat 1,252 square kilometers of fair habitat and 122 square kilometers of least suitable habitat.

  15. Sex differences in spatial ability: a test of the range size hypothesis in the order Carnivora

    OpenAIRE

    2011-01-01

    Sex differences in spatial cognition have been reported for many species ranging from voles to humans. The range size hypothesis predicts that sex differences in spatial ability will only occur in species in which the mating system selects for differential range size. Consistent with this prediction, we observed sex differences in spatial ability in giant pandas, a promiscuous species in which males inhabit larger ranges than females, but did not observe sex differences in Asian small-clawed ...

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Anahí E Formoso

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

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

    Science.gov (United States)

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

    2015-01-01

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

  19. Free-ranging farm cats: home range size and predation on a livestock unit in Northwest Georgia.

    Science.gov (United States)

    Kitts-Morgan, Susanna E; Caires, Kyle C; Bohannon, Lisa A; Parsons, Elizabeth I; Hilburn, Katharine A

    2015-01-01

    This study's objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.

  20. Free-Ranging Farm Cats: Home Range Size and Predation on a Livestock Unit In Northwest Georgia

    Science.gov (United States)

    Kitts-Morgan, Susanna E.; Caires, Kyle C.; Bohannon, Lisa A.; Parsons, Elizabeth I.; Hilburn, Katharine A.

    2015-01-01

    This study’s objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife. PMID:25894078

  1. Unifying latitudinal gradients in range size and richness across marine and terrestrial systems.

    Science.gov (United States)

    Tomašových, Adam; Kennedy, Jonathan D; Betzner, Tristan J; Kuehnle, Nicole Bitler; Edie, Stewart; Kim, Sora; Supriya, K; White, Alexander E; Rahbek, Carsten; Huang, Shan; Price, Trevor D; Jablonski, David

    2016-05-11

    Many marine and terrestrial clades show similar latitudinal gradients in species richness, but opposite gradients in range size-on land, ranges are the smallest in the tropics, whereas in the sea, ranges are the largest in the tropics. Therefore, richness gradients in marine and terrestrial systems do not arise from a shared latitudinal arrangement of species range sizes. Comparing terrestrial birds and marine bivalves, we find that gradients in range size are concordant at the level of genera. Here, both groups show a nested pattern in which narrow-ranging genera are confined to the tropics and broad-ranging genera extend across much of the gradient. We find that (i) genus range size and its variation with latitude is closely associated with per-genus species richness and (ii) broad-ranging genera contain more species both within and outside of the tropics when compared with tropical- or temperate-only genera. Within-genus species diversification thus promotes genus expansion to novel latitudes. Despite underlying differences in the species range-size gradients, species-rich genera are more likely to produce a descendant that extends its range relative to the ancestor's range. These results unify species richness gradients with those of genera, implying that birds and bivalves share similar latitudinal dynamics in net species diversification.

  2. The impact of temperature on the bionomics of Aedes (Stegomyia) aegypti, with special reference to the cool geographic range margins.

    Science.gov (United States)

    Eisen, Lars; Monaghan, Andrew J; Lozano-Fuentes, Saul; Steinhoff, Daniel F; Hayden, Mary H; Bieringer, Paul E

    2014-05-01

    The mosquito Aedes (Stegomyia) aegypti (L.), which occurs widely in the subtropics and tropics, is the primary urban vector of dengue and yellow fever viruses, and an important vector of chikungunya virus. There is substantial interest in how climate change may impact the bionomics and pathogen transmission potential of this mosquito. This Forum article focuses specifically on the effects of temperature on the bionomics of Ae. aegypti, with special emphasis on the cool geographic range margins where future rising temperatures could facilitate population growth. Key aims are to: 1) broadly define intra-annual (seasonal) patterns of occurrence and abundance of Ae. aegypti, and their relation to climate conditions; 2) synthesize the existing quantitative knowledge of how temperature impacts the bionomics of different life stages of Ae. aegypti; 3) better define the temperature ranges for which existing population dynamics models for Ae. aegypti are likely to produce robust predictions; 4) explore potential impacts of climate warming on human risk for exposure to Ae. aegypti at its cool range margins; and 5) identify knowledge or data gaps that hinder our ability to predict risk of human exposure to Ae. aegypti at the cool margins of its geographic range now and in the future. We first outline basic scenarios for intra-annual occurrence and abundance patterns for Ae. aegypti, and then show that these scenarios segregate with regard to climate conditions in selected cities where they occur. We then review how near-constant and intentionally fluctuating temperatures impact development times and survival of eggs and immatures. A subset of data, generated in controlled experimental studies, from the published literature is used to plot development rates and survival of eggs, larvae, and pupae in relation to water temperature. The general shape of the relationship between water temperature and development rate is similar for eggs, larvae, and pupae. Once the lower

  3. Contrasting growth forecasts across the geographical range of Scots pine due to altitudinal and latitudinal differences in climatic sensitivity.

    Science.gov (United States)

    Matías, Luis; Linares, Juan C; Sánchez-Miranda, Ángela; Jump, Alistair S

    2017-10-01

    Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of a species' geographical distribution, where differences in growth or population dynamics may result in range expansions or contractions. Understanding population responses to different climatic drivers along wide latitudinal and altitudinal gradients is necessary in order to gain a better understanding of plant responses to ongoing increases in global temperature and drought severity. We selected Scots pine (Pinus sylvestris L.) as a model species to explore growth responses to climatic variability (seasonal temperature and precipitation) over the last century through dendrochronological methods. We developed linear models based on age, climate and previous growth to forecast growth trends up to year 2100 using climatic predictions. Populations were located at the treeline across a latitudinal gradient covering the northern, central and southernmost populations and across an altitudinal gradient at the southern edge of the distribution (treeline, medium and lower elevations). Radial growth was maximal at medium altitude and treeline of the southernmost populations. Temperature was the main factor controlling growth variability along the gradients, although the timing and strength of climatic variables affecting growth shifted with latitude and altitude. Predictive models forecast a general increase in Scots pine growth at treeline across the latitudinal distribution, with southern populations increasing growth up to year 2050, when it stabilizes. The highest responsiveness appeared at central latitude, and moderate growth increase is projected at the northern limit. Contrastingly, the model forecasted growth declines at lowland-southern populations, suggesting an upslope range displacement over the coming decades. Our results give insight into the geographical responses of tree species to climate change

  4. Simple Indices Provide Insight to Climate Attributes Delineating the Geographic Range of Aedes albopictus (Diptera: Culicidae) Prior to Worldwide Invasion.

    Science.gov (United States)

    Mogi, Motoyoshi; Armbruster, Peter; Tuno, Nobuko; Campos, Raúl; Eritja, Roger

    2015-07-01

    Aedes albopictus (Skuse) has expanded its distribution worldwide during the past decades. Despite attempts to explain and predict its geographic occurrence, analyses of the distribution of Ae. albopictus in the context of broad climatic regions (biomes) has not been performed. We analyzed climate conditions at its distribution sites in the range before the worldwide invasions (from the easternmost Hawaii through westernmost Madagascar) by using thermal and aridity-humidity indices descriptive of major biomes. A significant advantage of this approach is that it uses simple indices clearly related to the population dynamics of Ae. albopictus. Although Ae. albopictus has been regarded as a forest species preferring humid climate, in areas with significant human habitation, the distribution sites extended from the perhumid, rain forest zone to the semiarid, steppe zone. This pattern was common from the tropics through the temperate zone. Across the distribution range, there was no seasonal discordance between temperature and precipitation; at sites where winter prevents Ae. albopictus reproduction (monthly means10°C) under the Asian summer monsoon. Absence of the species in northern and eastern coastal Australia and eastern coastal Africa was not attributable solely to climate conditions. However, Asia west of the summer monsoon range was climatically unsuitable because of low precipitation throughout the year or in warm months favorable to reproduction (concentration of precipitation in winter). We hypothesized that Ae. albopictus originated in continental Asia under the monsoon climate with distinct dry seasons and hot, wet summer, enabling rapid population growth.

  5. Aedes (Stegomyia) aegypti in the continental United States: a vector at the cool margin of its geographic range.

    Science.gov (United States)

    Eisen, Lars; Moore, Chester G

    2013-05-01

    After more than a half century without recognized local dengue outbreaks in the continental United States, there were recent outbreaks of autochthonous dengue in the southern parts of Texas (2004-2005) and Florida (2009-2011). This dengue reemergence has provoked interest in the extent of the future threat posed by the yellow fever mosquito, Aedes (Stegomyia) aegypti (L.), the primary vector of dengue and yellow fever viruses in urban settings, to human health in the continental United States. Ae. aegypti is an intriguing example of a vector species that not only occurs in the southernmost portions of the eastern United States today but also is incriminated as the likely primary vector in historical outbreaks of yellow fever as far north as New York, Philadelphia, and Boston, from the 1690s to the 1820s. For vector species with geographic ranges limited, in part, by low temperature and cool range margins occurring in the southern part of the continental United States, as is currently the case for Ae. aegypti, it is tempting to speculate that climate warming may result in a northward range expansion (similar to that seen for Ixodes tick vectors of Lyme borreliosis spirochetes in Scandinavia and southern Canada in recent decades). Although there is no doubt that climate conditions directly impact many aspects of the life history of Ae. aegypti, this mosquito also is closely linked to the human environment and directly influenced by the availability of water-holding containers for oviposition and larval development. Competition with other container-inhabiting mosquito species, particularly Aedes (Stegomyia) albopictus (Skuse), also may impact the presence and local abundance of Ae. aegypti. Field-based studies that focus solely on the impact of weather or climate factors on the presence and abundance of Ae. aegypti, including assessments of the potential impact of climate warming on the mosquito's future range and abundance, do not consider the potential confounding

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

    Science.gov (United States)

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

    2013-07-01

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

  7. Molecular phylogeny reveals high diversity, geographic structure and limited ranges in neotenic net-winged beetles platerodrilus (coleoptera: lycidae).

    Science.gov (United States)

    Masek, Michal; Palata, Vaclav; Bray, Timothy C; Bocak, Ladislav

    2014-01-01

    The neotenic Platerodrilus net-winged beetles have strongly modified development where females do not pupate and retain larval morphology when sexually mature. As a result, dispersal propensity of females is extremely low and the lineage can be used for reconstruction of ancient dispersal and vicariance patterns and identification of centres of diversity. We identified three deep lineages in Platerodrilus occurring predominantly in (1) Borneo and the Philippines, (2) continental Asia, and (3) Sumatra, the Malay Peninsula and Java. We document limited ranges of all species of Platerodrilus and complete species level turnover between the Sunda Islands and even between individual mountain regions in Sumatra. Few dispersal events were recovered among the major geographical regions despite long evolutionary history of occurrence; all of them were dated at the early phase of Platerodrilus diversification up to the end of Miocene and no exchange of island faunas was identified during the Pliocene and Pleistocene despite the frequently exposed Sunda Shelf as sea levels fluctuated with each glacial cycle. We observed high diversity in the regions with persisting humid tropical forests during cool periods. The origins of multiple species were inferred in Sumatra soon after the island emerged and the mountain range uplifted 15 million years ago with the speciation rate lower since then. We suppose that the extremely low dispersal propensity makes Platerodrilus a valuable indicator of uninterrupted persistence of rainforests over a long time span. Additionally, if the diversity of these neotenic lineages is to be protected, a high dense system of protected areas would be necessary.

  8. Summer Home Range Size and Habitat Use by River Otters in Ohio

    Directory of Open Access Journals (Sweden)

    David A. Helon

    2004-01-01

    Full Text Available Reintroduced river otters (Lontra canadensis are an important component of Ohio’s biological diversity, and are a key indicator of wetland and watershed health and quality. However, few data are available on their home range sizes and habitat use. We monitored river otters using radio-telemetry in the Killbuck Watershed, in northeastern Ohio, during 2002 and 2003 to determine home range and habitat use. Overall, mean home range size was 802.4 ha (range = 84.5–3,376.3, SE = 448.2 for female river otters and 1,101.7 ha (range = 713.8–1,502.6, SE = 102.2 for male river otters. Home range size of female and male river otters did not differ in 2002 (P = 0.763, but males had larger home range size than females during 2003 (P = 0.001. Based on compositional analysis, habitat use differed in proportion to availability of the 5 habitat types available in the study area (marsh, wet meadow, riparian/floodplain, open water, and flooded upland (P < 0.0001. Overall, river otters used marsh habitat with a diverse association of floating aquatics and emergent vegetation in greater proportion than was available. Knowledge and understanding of river otter habitat use and home range size in Ohio will help managers identify habitats suitable for river otters in the Midwestern United States.

  9. Testing adaptive regime shifts for range size evolution of endemic birds of China

    Directory of Open Access Journals (Sweden)

    Youhua Chen

    2016-03-01

    Full Text Available In this brief report, adaptive regime shifts for the range size evolution of the endemic birds of China were identified. Four models with different biological meanings were tested and compared through maximum likelihood models, including the Brownian motion model, one global optimal range size model for all lineages in the phylogeny, two optimal regime model of range sizes for lineages with large and small range sizes (OU2, and three optimal regime model in which an additional regime is added to the ancestral lineages. The results of model evaluation and comparison using the maximum likelihood technique show that over 48 endemic taxa, two optimal regimes (the OU2 model were observed for bird lineages with large and small range sizes in the country. The possible reasons for such an observation were outlined accordingly, including the different evolutionary times, which were subjected to different historical and geological conditions, heterogeneous environmental conditions, and complex climatic fluctuations. Overall, the range size evolution of the endemic taxa was subjected to multiple selective stresses. For future implications, more studies are desired to provide a holistic view of the evolution and divergence of endemic taxa.

  10. Multielemental fractionation in pine nuts (Pinus pinea) from different geographic origins by size-exclusion chromatography with UV and inductively coupled plasma mass spectrometry detection.

    Science.gov (United States)

    Gómez-Ariza, J L; Arias-Borrego, A; García-Barrera, T

    2006-07-21

    Pine nuts (Pinus pinea) from different geographical origin in Spain and Portugal have been investigated concerning total element content and metal-biomolecules size distribution patterns Mn, Zn, Ni and Cu. All the studied metals were at the highest concentration in pine nuts from Faro and at the lowest from Cataluña. The most abundant element in samples was Mn at concentrations in the range of 26 microg g(-1) (Cataluña) to 559 microg g(-1) (Faro). Zn was also present at high concentration in samples, from 25 microg g(-1) (Cataluña) to 113 microg g(-1) (Faro). To a deeper insight to obtain classification rules for samples, pine nuts were analyzed by size-exclusion chromatography (SEC) with UV detection and inductively coupled plasma mass spectrometry (ICP-MS). Two columns were used covering the molecular weigh range from pine nuts from Huelva. This column allows good discrimination in the range of 2126-1352 Da in which a lot of peaks can be used to differentiate samples. The UV profiles obtained with the high molecular weight (HMW) column allows a poorer differentiation of samples, but pine nuts from Huelva, Castilla and Madrid are clearly distinguished to the others. In relation to fractionation patterns of metals, Mn allows a good discrimination between samples (LMW column), Cu was the only one associated to fractions at MW > 70 kDa in sample from Cádiz, and profiles of Ni and Zn are clearly different in terms of abundance of peaks. All these chromatographic profiles for elements give valuable information about the geographical origin of the studied samples and the differences found are discussed in this work.

  11. Prevalence of intraspecific relationships between range size and abundance in Danish birds

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe; Rahbek, Carsten

    2006-01-01

    In this study, we investigate patterns in the prevalence of dynamic range-abundance relationships of the Danish avifauna, using breeding bird atlases from 1971 to 1974 and from 1993 to 1996. We focus on differences between common and rare species by dividing the assemblage into range-size quartiles...

  12. Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size

    Science.gov (United States)

    Namgail, Tsewang; Takekawa, John Y.; Balachandran, Sivananinthaperumal; Sathiyaselvam, Ponnusamy; Mundkur, Taej; Newman, Scott H.

    2014-01-01

    Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.

  13. Testing abundance-range size relationships in European carabid beetles (Coleoptera, Carabidae)

    NARCIS (Netherlands)

    Kotze, J.; Niemelä, J.; O'Hara, R.B.; Turin, H.

    2003-01-01

    Four of the eight hypotheses proposed in the literature for explaining the relationship between abundance and range size (the sampling artifact, phylogenetic non-independence, range position and resource breadth hypotheses) were tested by using atlas data for carabid beetles (Coleoptera, Carabidae)

  14. Testing abundance-range size relationships in European carabid beetles (Coleoptera, Carabidae)

    NARCIS (Netherlands)

    Kotze, J.; Niemelä, J.; O'Hara, R.B.; Turin, H.

    2003-01-01

    Four of the eight hypotheses proposed in the literature for explaining the relationship between abundance and range size (the sampling artifact, phylogenetic non-independence, range position and resource breadth hypotheses) were tested by using atlas data for carabid beetles (Coleoptera, Carabidae)

  15. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

    Directory of Open Access Journals (Sweden)

    Mark A Edwards

    Full Text Available The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

  16. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E; Nagy, John A

    2013-01-01

    The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos) of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

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

    Directory of Open Access Journals (Sweden)

    Roberta Gomes Carvalho/

    2014-09-01

    Full Text Available 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.

  18. Barcoding of Asian seabass across its geographic range provides evidence for its bifurcation into two distinct species

    Directory of Open Access Journals (Sweden)

    Shubha eVij

    2014-08-01

    Full Text Available Asian seabass or barramundi (Lates calcarifer is an important food fish with commercial value and a wide geographic distribution. Though some reports based on molecular and/or morphological data exist, a comprehensive effort to establish species identity across its range is lacking. In order to address this issue and especially to ascertain whether the wide-spread distribution has resulted in bifurcation of the species, we collected Asian seabass samples from various locations representing the Western and Eastern Coastline of India, Andaman and Nicobar Islands, Bangladesh and Australia. Samples from Malaysia, Indonesia, Thailand and Singapore were collected as part of a previous study. DNA sequence variations, including cytochrome c oxidase subunit 1 (COI, 16S rDNA and the highly variable D-loop (or control region, were examined to establish species delineation. Data from all the sequences analyzed concordantly point to the existence of at least two distinct species - one representing the Indian subcontinent plus Myanmar, and a second, representing Southeast Asia (Singapore, Malaysia, Thailand and Indonesia plus Northern Australia. These data are useful for conservation ecology, aquaculture management, for establishing the extent of genetic diversity in the Asian seabass and implementing selective breeding programs for members of this species complex.

  19. Range and Size Estimation Based on a Coordinate Transformation Model for Driving Assistance Systems

    Science.gov (United States)

    Wu, Bing-Fei; Lin, Chuan-Tsai; Chen, Yen-Lin

    This paper presents new approaches for the estimation of range between the preceding vehicle and the experimental vehicle, estimation of vehicle size and its projective size, and dynamic camera calibration. First, our proposed approaches adopt a camera model to transform coordinates from the ground plane onto the image plane to estimate the relative position between the detected vehicle and the camera. Then, to estimate the actual and projective size of the preceding vehicle, we propose a new estimation method. This method can estimate the range from a preceding vehicle to the camera based on contact points between its tires and the ground and then estimate the actual size of the vehicle according to the positions of its vertexes in the image. Because the projective size of a vehicle varies with respect to its distance to the camera, we also present a simple and rapid method of estimating a vehicle's projective height, which allows a reduction in computational time for size estimation in real-time systems. Errors caused by the application of different camera parameters are also estimated and analyzed in this study. The estimation results are used to determine suitable parameters during camera installation to suppress estimation errors. Finally, to guarantee robustness of the detection system, a new efficient approach to dynamic calibration is presented to obtain accurate camera parameters, even when they are changed by camera vibration owing to on-road driving. Experimental results demonstrate that our approaches can provide accurate and robust estimation results of range and size of target vehicles.

  20. Estimating home-range size: when to include a third dimension?

    Science.gov (United States)

    Monterroso, Pedro; Sillero, Neftalí; Rosalino, Luís Miguel; Loureiro, Filipa; Alves, Paulo Célio

    2013-07-01

    Most studies dealing with home ranges consider the study areas as if they were totally flat, working only in two dimensions, when in reality they are irregular surfaces displayed in three dimensions. By disregarding the third dimension (i.e., topography), the size of home ranges underestimates the surface actually occupied by the animal, potentially leading to misinterpretations of the animals' ecological needs. We explored the influence of considering the third dimension in the estimation of home-range size by modeling the variation between the planimetric and topographic estimates at several spatial scales. Our results revealed that planimetric approaches underestimate home-range size estimations, which range from nearly zero up to 22%. The difference between planimetric and topographic estimates of home-ranges sizes produced highly robust models using the average slope as the sole independent factor. Moreover, our models suggest that planimetric estimates in areas with an average slope of 16.3° (±0.4) or more will incur in errors ≥5%. Alternatively, the altitudinal range can be used as an indicator of the need to include topography in home-range estimates. Our results confirmed that home-range estimates could be significantly biased when topography is disregarded. We suggest that study areas where home-range studies will be performed should firstly be scoped for its altitudinal range, which can serve as an indicator for the need for posterior use of average slope values to model the surface area used and/or available for the studied animals.

  1. Mountain gorilla ranging patterns: influence of group size and group dynamics.

    Science.gov (United States)

    Caillaud, Damien; Ndagijimana, Felix; Giarrusso, Anthony J; Vecellio, Veronica; Stoinski, Tara S

    2014-08-01

    Since the 1980s, the Virunga mountain gorilla population has almost doubled, now reaching 480 individuals living in a 430-km(2) protected area. Analysis of the gorillas' ranging patterns can provide critical information on the extent and possible effects of competition for food and space. We analyzed 12 years of daily ranging data and inter-group encounter data collected on 11 gorilla groups monitored by the Karisoke Research Center in Rwanda. During that period, the study population increased in size by almost 50% and the number of groups tripled. Groups had small yearly home ranges compared to other known gorilla populations, with an average 90% kernel density estimate of 8.07 km2 and large between-group variations (3.17-23.59 km2). Most groups had consistent home range location over the course of the study but for some, we observed gradual range shifts of up to 4 km. Neighboring groups displayed high home range overlap, which increased dramatically after the formation of new groups. On average, each group used only 28.6% of its 90% kernel home range exclusively, and in some areas up to six different groups had overlapping home ranges with little or no exclusive areas. We found a significant intra-group positive relationship between the number of weaned individuals in a group and the home range size, but the fitted models only explained 17.5% and 13.7% of the variance in 50% and 90% kernel home range size estimates, respectively. This suggests that despite the increase in size, the study population is not yet experiencing marked effects of feeding competition. However, the increase in home range overlap resulting from the formation of new groups led to a sixfold increase in the frequency of inter-group encounters, which exposes the population to elevated risks of fight-related injuries and infanticide.

  2. Fluorescent dye labeled DNA size standards for molecular mass detection in visible/infrared range

    Directory of Open Access Journals (Sweden)

    Sreelakshmi Yellamaraju

    2011-01-01

    Full Text Available Abstract Background Targeting Induced Local Lesions in Genomes (TILLING is a high throughput reverse genetics tool which detects mismatches (single point mutations or small indels in large number of individuals of mutagenized populations. Currently, TILLING is intensively used for genomics assisted molecular breeding of several crop plants for desired traits. Most commonly used platform for mutation detection is Li-COR DNA Analyzer, where PCR amplified products treated with single strand mismatch specific nuclease are resolved on denaturing gels. The molecular size of any cut product can be easily estimated by comparing with IR dye labeled markers of known sizes. Similar fluorescent dye labeled size markers are also used for several genotyping experiments. Currently, commercially available size standards are expensive and are restricted up to only 700 bp which renders estimation of products of sizes greater than 700 bases inaccurate. Findings A simple protocol was developed for labeling 5' end of multiple DNA size markers with fluorescent dyes. This method involves cloning a pool of different size markers of DNA in a plasmid vector. PCR amplification of plasmid using IR dye labeled universal primers generates 5' fluorescent labeled products of various sizes. The size of products constituting the ladder can be customized as per the need. The generated size markers can be used without any further purification and were found to be stable up to one year at -20°C. Conclusions A simple method was developed for generating fluorescent dye labeled size standards. This method can be customized to generate different size standards as per experimental needs. The protocol described can also be adapted for developing labeled size standards for detection on platforms other than Li-COR i.e. other than infra red range of the spectrum.

  3. The size and range effect: lifecycle greenhouse gas emissions of electric vehicles

    Science.gov (United States)

    Ager-Wick Ellingsen, Linda; Singh, Bhawna; Hammer Strømman, Anders

    2016-05-01

    The primary goal of this study is to investigate the effect of increasing battery size and driving range to the environmental impact of electric vehicles (EVs). To this end, we compile cradle-to-grave inventories for EVs in four size segments to determine their climate change potential. A second objective is to compare the lifecycle emissions of EVs to those of conventional vehicles. For this purpose, we collect lifecycle emissions for conventional vehicles reported by automobile manufacturers. The lifecycle greenhouse gas emissions are calculated per vehicle and over a total driving range of 180 000 km using the average European electricity mix. Process-based attributional LCA and the ReCiPe characterisation method are used to estimate the climate change potential from the hierarchical perspective. The differently sized EVs are compared to one another to find the effect of increasing the size and range of EVs. We also point out the sources of differences in lifecycle emissions between conventional- and electric vehicles. Furthermore, a sensitivity analysis assesses the change in lifecycle emissions when electricity with various energy sources power the EVs. The sensitivity analysis also examines how the use phase electricity sources influences the size and range effect.

  4. Fluctuation range of the concentration of airborne Alternaria conidiospores sampled at different geographical locations in Poland (2010–2011

    Directory of Open Access Journals (Sweden)

    Idalia Kasprzyk

    2013-04-01

    Full Text Available Knowledge of seasonal and diurnal fluctuations of allergenic and phytopathogenic fungal spores in the air and the determination of the influence of weather and environmental parameters on spore concentrations are of great practical use in control of both human and animal health as well as plant diseases. The aim of this study was to evaluate the dynamics of the occurrence of Alternaria spores in the air at three sites located in different geographical regions of Poland. The study was done from 15 April to 30 September in 2010–2011 in Rzeszów (Carpathian Foothills, south-east Poland, Lublin (Lublin Upland, central east, and Poznań (central west; the distance between the experimental sites ranged from 138 to 441 km. To assess the concentration of Alternaria spores, the volumetric method was used. In both years, the highest concentration of spores was observed in Poznań and the lowest in Rzeszów. In 2010 the annual total, monthly total and maximum spore concentration were higher than in 2011 at all monitoring sites. The greatest concentration of Alternaria spores was recorded in August, followed by July. High spore concentrations were also noted at the beginning of September. The differences in daily concentrations, average concentrations and cumulative numbers of spores were statistically significant. The reasons for this can be related not only to weather parameters, which is often raised in the literature, but also to the type of landscape. Landscape and geo-botanical conditions of Great Poland and Carpathian Foothills greatly differ. In both years, the highest number of Alternaria spores was found in Poznań – the city with the highest urbanization factor and the capital of the region with large-scale farming, connected with the intensification of agricultural practices.

  5. Optimizing components size of an extended range electric vehicle according to the use specifications

    OpenAIRE

    DEROLLEPOT, Romain; Weiss, Christine; KOLLI, Zehir; Franke, Thomas; Trigui, Rochdi; Chlond, Bastian; Armoogum, Jimmy; Stark, Juliane; Klementschitz, Roman; Baumann, Michael; PELISSIER, Serge

    2014-01-01

    This paper presents a methodology to optimally design the drivetrain of an Extended Range Electric Vehicle (EREV) according to the use specifications from European mobility surveys. At first the analysis of car uses is carried out, and a process aiming to classify the car use profiles into different clusters is proposed. Clusters that could fit typical EREV use are selected and applied in a sizing methodology to design the battery and the Range Extender (RE). Using a validated simulation soft...

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

    Directory of Open Access Journals (Sweden)

    Claudio J. Bidau

    2012-01-01

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

  7. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Science.gov (United States)

    Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin. PMID:27651991

  8. Variation in Bachman's Sparrow home-range size at the Savannah River Site, South Carolina

    Science.gov (United States)

    Stober, J.M.; Krementz, D.G.

    2006-01-01

    Using radiotelemetry, we studied variation in home-range size of the Bachman's Sparrow (Aimophila aestivalis) at the Savannah River Site (SRS), South Carolina, during the 1995 breeding season. At SRS, sparrows occurred primarily in two habitats: mature pine habitats managed for Red-cockaded Woodpecker (Picoides borealis) and pine plantations 1 to 6 years of age. The mean 95% minimum convex polygon home-range size for males and females combined (n = 14) was 2.95 ha + 0.57 SE, across all habitats. Mean homerange size for males in mature pine stands (4.79 ha + 0.27, n = 4) was significantly larger than that in 4-year-old (3.00 ha + 0.31, n = 3) and 2-year-old stands (1.46 ha + 0.31, it = 3). Home-range sizes of paired males and females (it = 4 pairs) were similar within habitat type; mean distances between consecutive locations differed by habitat type and sex. We hypothesize that a gradient in food resources drives home-range dynamics.

  9. Bryophyte diversity and range size distribution along two altitudinal gradients: Continent vs. island

    Science.gov (United States)

    Ah-Peng, Claudine; Wilding, Nicholas; Kluge, Juergen; Descamps-Julien, Blandine; Bardat, Jacques; Chuah-Petiot, Min; Strasberg, Dominique; Hedderson, Terry A. J.

    2012-07-01

    We compare patterns of bryophyte diversity and variation in species altitudinal ranges between a continental and an island altitudinal gradient. We use our ecological data set along the highest summit (Piton des Neiges, 3069 m) of Réunion Island (Mascarene archipelago) and compare it to available published data of another high volcanic massif in Colombia (Nevado del Ruiz, 5321 m). The distribution of narrow-ranged and large-ranged species was investigated. We tested the effect of geometric constraints on species distribution along the two gradients by comparing empirical to predicted data using the Mid-Domain Null Programme (McCain, 2004). Species richness was comparable between the island and continental gradient for epiphytic bryophytes, 265 and 295 species respectively. The comparison between the two tropical high mountains demonstrates important differences in the distribution of range sizes with altitude and a dominance of species with small range sizes on the Réunion gradient. For the island gradient, mean altitudinal range increases with altitude whilst concurrently species richness decreases revealing a Rapoport effect in altitudinal distribution of bryophyte communities. Geometric constraints did not explain much of the species richness pattern for the island. Conversely, for the continental gradient, dominated by large-ranged species, geometric constraints could not be ruled out as a primary structuring feature for the species richness pattern. This study also highlights that the island's cloud forest hosts not only high species richness but also high number of rare species, which is of prime interest for conservation planners.

  10. Rock size distributions on lava flow surfaces: New results from a range of compositions

    Science.gov (United States)

    Burke, M. P.; Anderson, S. W.; Bulmer, M. H.

    2005-12-01

    We measured block sizes along 15-25m orthogonal transects on 12 lava flows of compositions ranging from basalt to rhyolite. At each site, we stretched a line across the flow surface then measured the length of each block cut by this line that were greater than 3-12cm (depending on composition). The measurements from each site were reduced to cumulative size frequency distribution plots, with block size (D) plotted against the fraction of the line f(D) composed of blocks greater than or equal to that size, and fitted with an exponential curve of the form f(D) = k exp(-qD) where k is the intercept and q is the decay parameter. Average block size and geometric mean were also determined for each site. Our data show no clear trends linking average or mean block size to composition, although there does seem to be relationship between block size and the decay parameter. Block size corresponds with the decay parameter at each site except for the basaltic andesite flow at Paint Pot Crater (CA). Many sites at this flow were covered with secondary spatter deposits. Largest blocks and smallest decay parameters were found for the andesite flows at Sabancaya (Peru), while the basalt flows at Cima (CA) exhibited the smallest blocks and largest decay parameters. The second largest block sizes occurred at the four Inyo domes composed of both crystal-rich and glassy rhyolite, and these domes also showed the second smallest decay parameters. All four of the Inyo domes were emplaced along the same feeder dike trend, and the average and mean sizes and decay parameters at these domes are nearly identical, suggesting that composition, extrusion rate, or eruption history controls the block size distributions. However, values for the two andesitic flows, Mt. Shasta (CA) and Sabancaya, were very different, suggesting that extrusion rate and/or eruption history exert a stronger control over the block size distributions than does composition. LIDAR data sets are capable of detecting sub

  11. Quasi-long-range ordering in a finite-size 2D Heisenberg model

    CERN Document Server

    Kapikranian, O; Holovatch, Yu; Berche, Bertrand; Holovatch, Yurij; Kapikranian, Oleksandr

    2006-01-01

    We analyse the low-temperature behaviour of the Heisenberg model on a two-dimensional lattice of finite size. Presence of a residual magnetisation in a finite-size system enables us to use the spin wave approximation, which is known to give reliable results for the XY model at low temperatures T. For the system considered, we find that the spin-spin correlation function decays as 1/r^eta(T) for large separations r bringing about presence of a quasi-long-range ordering. We give analytic estimates for the exponent eta(T) in different regimes and support our findings by Monte Carlo simulations of the model on lattices of different sizes at different temperatures.

  12. Comparative studies on plant range size: Linking reproductive and regenerative traits in two Ipomoea species

    Science.gov (United States)

    Astegiano, Julia; Funes, Guillermo; Galetto, Leonardo

    2010-09-01

    Reproductive and regenerative traits associated with colonization and persistence ability may determine plant range size. However, few comparative studies on plant distribution have assessed these traits simultaneously. Pollinator richness and frequency of visits, autonomous self-pollination ability, reproductive output (i.e., reproductive traits), seed bank strategy and seedling density (i.e., regenerative traits) were compared between the narrowly distributed Ipomoea rubriflora O'Donnell (Convolvulaceae) and its widespread congener Ipomoea purpurea (L.) Roth. The narrowly distributed species showed higher ecological specialization to pollinators and lower autonomous self-pollination ability. Frequency of visits, natural seed/ovule ratio and fruit set, and total fruit production did not differ between species. However, the number of seeds produced per fruit was lower in the narrowly distributed species, translating into lower total seed production per plant. Indeed, I. rubriflora formed smaller transient and persistent seed banks and showed lower seedling density than the widespread I. purpurea. These reproductive and regenerative trait results suggest that the narrowly distributed species may have lower colonization and persistence ability than its widespread congener. They further suggest that the negative effects of lower fecundity in the narrowly distributed species might persist in time through the long-lasting effects of total seed production on seed bank size, reducing the species' ability to buffered environmental stochasticity. However, other regenerative traits, such as seed size, and processes such as pre- and post-dispersal seed predation, might modulate the effects of plant fecundity on plant colonization and persistence ability and thus range size.

  13. Size distribution of radon decay products in the range 0.1-10 nm.

    Science.gov (United States)

    Zhukovsky, Michael; Rogozina, Marina; Suponkina, Anna

    2014-07-01

    Information about the size distribution of radioactive aerosols in nanometre range is essential for the purposes of air contamination monitoring, dose assessment to respiratory tract and planning of protective measures. The diffusion battery, which allows capturing particles in the size range of 0.1-10 nm, has developed. Interpreting data obtained from diffusion battery is very complex. The method of expectation maximisation by Maher and Laird was chosen for indirect inversion data. The experiments were performed in the box with equivalent equilibrium concentration of radon in the range of 7000-10,000 Bq m(-3). The three modes of size distribution of radon decay products aerosols were obtained: activity median thermodynamic diameter (AMTD) 0.3, 1.5 and 5 nm. These modes can be identified as: AMTD 0.3 nm--atoms of radon progeny (218Po in general); AMTD 1.5 nm--clusters of radon progeny atoms and non-radioactive atoms in the atmosphere; AMTD 5 nm--particles formed by coagulation of previous mode clusters with existing aerosol particles or nucleation of condensation nuclei containing atoms of radon progeny. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Molecular subdivision of the marine diatom Thalassiosira rotula in relation to geographic distribution, genome size, and physiology

    Directory of Open Access Journals (Sweden)

    Whittaker Kerry A

    2012-10-01

    Full Text Available Abstract 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

  15. Performance of diethylene glycol-based particle counters in the sub-3 nm size range

    Directory of Open Access Journals (Sweden)

    D. Wimmer

    2013-07-01

    Full Text Available When studying new particle formation, the uncertainty in determining the "true" nucleation rate is considerably reduced when using condensation particle counters (CPCs capable of measuring concentrations of aerosol particles at sizes close to or even at the critical cluster size (1–2 nm. Recently, CPCs able to reliably detect particles below 2 nm in size and even close to 1 nm became available. Using these instruments, the corrections needed for calculating nucleation rates are substantially reduced compared to scaling the observed formation rate to the nucleation rate at the critical cluster size. However, this improved instrumentation requires a careful characterization of their cut-off size and the shape of the detection efficiency curve because relatively small shifts in the cut-off size can translate into larger relative errors when measuring particles close to the cut-off size. Here we describe the development of two continuous-flow CPCs using diethylene glycol (DEG as the working fluid. The design is based on two TSI 3776 counters. Several sets of measurements to characterize their performance at different temperature settings were carried out. Furthermore, two mixing-type particle size magnifiers (PSM A09 from Airmodus were characterized in parallel. One PSM was operated at the highest mixing ratio (1 L min−1 saturator flow, and the other was operated in a scanning mode, where the mixing ratios are changed periodically, resulting in a range of cut-off sizes. The mixing ratios are determined by varying the saturator flow, where the aerosol flow stays constant at 2.5 L min−1. Different test aerosols were generated using a nano-differential mobility analyser (nano-DMA or a high-resolution DMA, to obtain detection efficiency curves for all four CPCs. One calibration setup included a high-resolution mass spectrometer (APi-TOF for the determination of the chemical composition of the generated clusters. The lowest cut-off sizes were

  16. Performance of diethylene glycol based particle counters in the sub 3 nm size range

    Directory of Open Access Journals (Sweden)

    D. Wimmer

    2013-02-01

    Full Text Available When studying new particle formation, the uncertainty in determining the "true" nucleation rate is considerably reduced when using Condensation Particle Counters (CPCs capable of measuring concentrations of aerosol particles at sizes close to or even at the critical cluster size (1–2 nm. Recently CPCs, able to reliably detect particles below 2 nm in size and even close to 1 nm became available. The corrections needed to calculate nucleation rates are substantially reduced compared to scaling the observed formation rate to the nucleation rate at the critical cluster size. However, this improved instrumentation requires a careful characterization of their cut-off size and the shape of the detection efficiency curve because relatively small shifts in the cut-off size can translate into larger relative errors when measuring particles close to the cut-off size.

    Here we describe the development of two continuous flow CPCs using diethylene glycol (DEG as the working fluid. The design is based on two TSI 3776 counters. Several sets of measurements to characterize their performance at different temperature settings were carried out. Furthermore two mixing-type Particle Size Magnifiers (PSM A09 from Airmodus were characterized in parallel. One PSM was operated at the highest mixing ratio (1 L min−1 saturator flow, and the other was operated in a scanning mode, where the mixing ratios are changed periodically, resulting in a range of cut-off sizes. Different test aerosols were generated using a nano-Differential Mobility Analyzer (nano-DMA or a high resolution DMA, to obtain detection efficiency curves for all four CPCs. One calibration setup included a high resolution mass spectrometer (APi-TOF for the determination of the chemical composition of the generated clusters. The lowest cut-off sizes were achieved with negatively charged ammonium sulphate clusters, resulting in cut-offs of 1.4 nm for the laminar flow CPCs and 1.2 and 1

  17. I. Sexual, individual, and geographical variation in leucosticte tephrocotis, II.Geographical variation among North American mammals, especially in respect to size

    Science.gov (United States)

    Allen, J.A.

    1876-01-01

    Having recently had an opportunity (through the kindness of Professor Baird) of studying with some care the magnificent series of skulls of the North American Mammalia belonging to the National Museum (amounting often to eighty or a hundred specimens of a single species), I have been strongly impressed with the different degrees of variability exhibited by the representatives of the species and genera of even the same family. The variation in size, for instance, with latitude, in the Wolves and Foxes is surprisingly great, amounting in some species (as will be shown later) to 25 per cent. of the average size of the species, while in other species of the Ferae it is almost nil. Contrary to the general supposition, the variation in size among representatives of the same species is not always a decrease with the decrease of the latitude of the locality, but is in some cases exactly the reverse, in some species there being a very considerable and indisputable increase southward. This, for instance, is very markedly true of some species of Felis and in Procyon lotor. Consequently, the very generally-received impression that in North America the species of Mammalia diminish in size southward, or with the decrease in the latitude (and altitude) of the locality, requires modification. While such is generally the case, the reverse of this too often occurs, with occasional instances also of a total absence of variation in size with locality, to be considered as forming "the exceptions" necessary to "prove the rule".

  18. The distribution and abundance of an island population of Koalas (Phascolarctos cinereus in the far north of their geographic range.

    Directory of Open Access Journals (Sweden)

    Denise C McGregor

    Full Text Available Koalas are an iconic species of charismatic megafauna, of substantial social and conservation significance. They are widely distributed, often at low densities, and individuals can be difficult to detect, making population surveys challenging and costly. Consequently, koala population estimates have been limited and the results inconsistent. The aims of this study were to estimate the distribution, relative abundance and population size of the koalas on Magnetic Island, far north Queensland. Population densities were estimated in 18 different vegetation types present on the island using a Fecal Standing Crop Method. Koala density ranged from 0.404 ha(-1, recorded in forest red gum and bloodwood woodland, to absence from eight of the vegetation types surveyed. The second highest density of 0.297 koalas ha(-1 was recorded in mixed eucalypt woodland, which covers 45% of the island. The total abundance of koalas on Magnetic Island, not including those present in urban areas, was estimated at 825±175 (SEM. The large variation in koala density across vegetation types reinforces the need for sampling stratification when calculating abundance over large areas, as uniformity of habitat quality cannot be assumed. In this context, koala populations also occur in low densities in areas generally regarded as poor quality koala habitat. These results highlight the importance of protecting vegetation communities not traditionally considered to have high conservation value to koalas, as these habitats may be essential for maintaining viable, widespread, low-density populations. The results from this study provide a baseline to assess future trends in koala distribution, density and abundance on Magnetic Island.

  19. The distribution and abundance of an island population of Koalas (Phascolarctos cinereus) in the far north of their geographic range.

    Science.gov (United States)

    McGregor, Denise C; Kerr, Sarah E; Krockenberger, Andrew K

    2013-01-01

    Koalas are an iconic species of charismatic megafauna, of substantial social and conservation significance. They are widely distributed, often at low densities, and individuals can be difficult to detect, making population surveys challenging and costly. Consequently, koala population estimates have been limited and the results inconsistent. The aims of this study were to estimate the distribution, relative abundance and population size of the koalas on Magnetic Island, far north Queensland. Population densities were estimated in 18 different vegetation types present on the island using a Fecal Standing Crop Method. Koala density ranged from 0.404 ha(-1), recorded in forest red gum and bloodwood woodland, to absence from eight of the vegetation types surveyed. The second highest density of 0.297 koalas ha(-1) was recorded in mixed eucalypt woodland, which covers 45% of the island. The total abundance of koalas on Magnetic Island, not including those present in urban areas, was estimated at 825±175 (SEM). The large variation in koala density across vegetation types reinforces the need for sampling stratification when calculating abundance over large areas, as uniformity of habitat quality cannot be assumed. In this context, koala populations also occur in low densities in areas generally regarded as poor quality koala habitat. These results highlight the importance of protecting vegetation communities not traditionally considered to have high conservation value to koalas, as these habitats may be essential for maintaining viable, widespread, low-density populations. The results from this study provide a baseline to assess future trends in koala distribution, density and abundance on Magnetic Island.

  20. Lead particle size and its association with firing conditions and range maintenance: implications for treatment.

    Science.gov (United States)

    Dermatas, Dimitris; Chrysochoou, Maria

    2007-08-01

    Six firing range soils were analyzed, representing different environments, firing conditions, and maintenance practices. The particle size distribution and lead (Pb) concentration in each soil fraction were determined for samples obtained from the backstop berms. The main factors that were found to influence Pb fragment size were the type of soil used to construct the berms and the type of weapon fired. The firing of high velocity weapons, i.e., rifles, onto highly angular soils induced significant fragmentation of the bullets and/or pulverization of the soil itself. This resulted in the accumulation of Pb in the finer soil fractions and the spread of Pb contamination beyond the vicinity of the backstop berm. Conversely, the use of clay as backstop and the use of low velocity pistols proved to be favorable for soil clean-up and range maintenance, since Pb was mainly present as large metallic fragments that can be recovered by a simple screening process. Other factors that played important roles in Pb particle size distribution were soil chemistry, firing distance, and maintenance practices, such as the use of water spray for dust suppression and deflectors prior to impact. Overall, coarse Pb particles provide much easier and more cost-effective maintenance, soil clean-up, and remediation via physical separation. Fine Pb particles release Pb more easily, pose an airborne Pb hazard, and require the application of stabilization/solidification treatment methods. Thus, to ensure sustainable firing range operations by means of cost-effective design, maintenance, and clean-up, especially when high velocity weapons are used, the above mentioned factors should be carefully considered.

  1. An Improved Method for Including Upper Size Range Plasmids in Metamobilomes

    DEFF Research Database (Denmark)

    Norman, Anders; Riber, Leise; Luo, Wenting

    2014-01-01

    cloning vector (pBR322), and a 56 Kbp conjugative plasmid (pKJK10), to represent lower- and upper plasmid size ranges, respectively. Subjecting a mixture of these plasmids to the overall isolation protocol revealed a 34-fold over-amplification of pBR322 after MDA. To address this bias, we propose......, as gene functions associated with these plasmids, such as conjugation, was exclusively encoded in the data output generated through the modified protocol. Thus, with the suggested modification, access to a large uncharacterized pool of accessory elements that reside on medium-to-large plasmids has been...

  2. Microhabitat selection, demography, and correlates of home range size for the King Rail (Rallus elegans)

    Science.gov (United States)

    Pickens, Bradley A.; King, Sammy L.

    2013-01-01

    Animal movements and habitat selection within the home range, or microhabitat selection, can provide insights into habitat requirements, such as foraging and area requirements. The King Rail (Rallus elegans) is a wetland bird of high conservation concern in the United States, but little is known about its movements, habitats, or demography. King Rails (n = 34) were captured during the 2010–2011 breeding seasons in the coastal marshes of southwest Louisiana and southeast Texas. Radio telemetry and direct habitat surveys of King Rail locations were conducted to estimate home ranges and microhabitat selection. Within home ranges, King Rails selected for greater plant species richness and comparatively greater coverage of Phragmites australis, Typha spp., and Schoenoplectus robustus. King Rails were found closer to open water compared to random locations placed 50 m from King Rail locations. Home ranges (n = 22) varied from 0.8–32.8 ha and differed greatly among sites. Home range size did not vary by year or sex; however, increased open water, with a maximum of 29% observed in the study, was correlated with smaller home ranges. Breeding season cumulative survivorship was 89% ± 22% in 2010 and 61% ± 43% in 2011, which coincided with a drought. With an equal search effort, King Rail chicks and juveniles observed in May-June decreased from 110 in 2010 to only 16 in the drier year of 2011. The findings show King Rail used marsh with ≤ 29% open water and had smaller home ranges when open water was more abundant.

  3. Asymmetric dihedral angle offsets for large-size lunar laser ranging retroreflectors

    Science.gov (United States)

    Otsubo, Toshimichi; Kunimori, Hiroo; Noda, Hirotomo; Hanada, Hideo; Araki, Hiroshi; Katayama, Masato

    2011-08-01

    The distribution of two-dimensional velocity aberration is off-centered by 5 to 6 microradians in lunar laser ranging, due to the stable measurement geometry in the motion of the Earth and the Moon. The optical responses of hollow-type retroreflectors are investigated through numerical simulations, especially focusing on large-size, single-reflector targets that can ultimately minimize the systematic error in future lunar laser ranging. An asymmetric dihedral angle offset, i.e. setting unequal angles between the three back faces, is found to be effective for retroreflectors that are larger than 100 mm in diameter. Our numerical simulation results reveal that the optimized return energy increases approximately 3.5 times more than symmetric dihedral angle cases, and the optimized dihedral angle offsets are 0.65-0.8 arcseconds for one angle, and zeroes for the other two angles.

  4. Mechanobiological induction of long-range contractility by diffusing biomolecules and size scaling in cell assemblies

    Science.gov (United States)

    Dasbiswas, K.; Alster, E.; Safran, S. A.

    2016-06-01

    Mechanobiological studies of cell assemblies have generally focused on cells that are, in principle, identical. Here we predict theoretically the effect on cells in culture of locally introduced biochemical signals that diffuse and locally induce cytoskeletal contractility which is initially small. In steady-state, both the concentration profile of the signaling molecule as well as the contractility profile of the cell assembly are inhomogeneous, with a characteristic length that can be of the order of the system size. The long-range nature of this state originates in the elastic interactions of contractile cells (similar to long-range “macroscopic modes” in non-living elastic inclusions) and the non-linear diffusion of the signaling molecules, here termed mechanogens. We suggest model experiments on cell assemblies on substrates that can test the theory as a prelude to its applicability in embryo development where spatial gradients of morphogens initiate cellular development.

  5. Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range.

    Science.gov (United States)

    Sundar, N; Asmundsson, I M; Thomas, N J; Samuel, M D; Dubey, J P; Rosenthal, B M

    2008-03-25

    Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

  6. Modest genetic differentiation among North American populations of Sarcocystic neurona may reflect expansion in its geographic range

    Science.gov (United States)

    Sundar, N.; Asmundsson, I.M.; Thomas, N.J.; Samuel, M.D.; Dubey, J.P.; Rosenthal, B.M.

    2008-01-01

    Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

  7. Size-Related Differences in the Thermoregulatory Habits of Free-Ranging Komodo Dragons

    Directory of Open Access Journals (Sweden)

    Henry J. Harlow

    2010-01-01

    Full Text Available Thermoregulatory processes were compared among three-size groups of free-ranging Komodo dragons (Varanus komodoensis comprising small (5–20 kg, medium (20–40 gm and large (40–70 kg lizards. While all size groups maintained a similar preferred body temperature of ≈35∘C, they achieved this end point differently. Small dragons appeared to engage in sun shuttling behavior more vigorously than large dragons as represented by their greater frequency of daily ambient temperature and light intensity changes as well as a greater activity and overall exposure to the sun. Large dragons were more sedentary and sun shuttled less. Further, they appear to rely to a greater extent on microhabitat selection and employed mouth gaping evaporative cooling to maintain their preferred operational temperature and prevent overheating. A potential ecological consequence of size-specific thermoregulatory habits for dragons is separation of foraging areas. In part, differences in thermoregulation could contribute to inducing shifts in predatory strategies from active foraging in small dragons to more sedentary sit-and-wait ambush predators in adults.

  8. Diffusion of Oxygen Isotopes in Thermally Evolving Planetesimals and Size Ranges of Presolar Silicate Grains

    Science.gov (United States)

    Wakita, Shigeru; Nozawa, Takaya; Hasegawa, Yasuhiro

    2017-02-01

    Presolar grains are small particles found in meteorites through their isotopic compositions, which are considerably different from those of materials in the solar system. If some isotopes in presolar grains diffused out beyond their grain sizes when they were embedded in parent bodies of meteorites, their isotopic compositions could be washed out, and hence the grains could no longer be identified as presolar grains. We explore this possibility for the first time by self-consistently simulating the thermal evolution of planetesimals and the diffusion length of 18O in presolar silicate grains. Our results show that presolar silicate grains smaller than ˜0.03 μm cannot keep their original isotopic compositions even if the host planetesimals experienced a maximum temperature as low as 600 °C. Since this temperature corresponds to that experienced by petrologic type 3 chondrites, isotopic diffusion can constrain the size of presolar silicate grains discovered in such chondrites to be larger than ˜0.03 μm. We also find that the diffusion length of 18O reaches ˜0.3-2 μm in planetesimals that were heated up to 700-800°C. This indicates that, if the original size of presolar grains spans a range from ˜0.001 μm to ˜0.3 μm like that in the interstellar medium, then the isotopic records of the presolar grains may be almost completely lost in such highly thermalized parent bodies. We propose that isotopic diffusion could be a key process to control the size distribution and abundance of presolar grains in some types of chondrites.

  9. Next generation cooled long range thermal sights with minimum size, weight, and power

    Science.gov (United States)

    Breiter, R.; Ihle, T.; Wendler, J.; Rühlich, I.; Ziegler, J.

    2013-06-01

    Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

  10. A comparison of the home range sizes of mainland and island populations of black-faced lion tamarins (Leontopithecus caissara) using different spatial analysis.

    Science.gov (United States)

    Nascimento, Alexandre T Amaral; Schmidlin, Lucia A J; Valladares-Padua, Claudio B; Matushima, Eliana R; Verdade, Luciano M

    2011-11-01

    The critically endangered black-faced lion tamarin, Leontopithecus caissara, has a restricted geographical distribution consisting of small mainland and island populations, each with distinct habitats in coastal southeastern Brazil. Necessary conservation management actions require an assessment of whether differences in habitats are reflected in use of space by the species. We studied two tamarin groups on the mainland at São Paulo state between August 2005 and March 2007, and compared the results with data from Superagui Island. Three home range estimators were used: minimum convex polygon (MCP), Kernel, and the new technique presented dissolved monthly polygons (DMP). These resulted, respectively, in home ranges of 345, 297, and 282 ha for the 12-month duration of the study. Spatial overlap of mainland groups was extensive, whereas temporal overlap was not, a pattern that indicates resource partitioning is an important strategy to avoid intraspecific competition. L. caissara large home ranges seem to be dynamic, with constant incorporation of new areas and abandonment of others through time. The main difference between mainland and island groups is the amount and variety of sleeping sites. A better understanding of the home range sizes, day range lengths, and territorial behavior of this species will aid in developing better management strategies for its protection. Additionally, the presented DMP protocol is a useful improvement over the MCP method as it results in more realistic home range sizes for wildlife species. © 2011 Wiley Periodicals, Inc.

  11. Molecular mass ranges of coal tar pitch fractions by mass spectrometry and size-exclusion chromatography.

    Science.gov (United States)

    Karaca, F; Morgan, T J; George, A; Bull, I D; Herod, A A; Millan, M; Kandiyoti, R

    2009-07-01

    A coal tar pitch was fractionated by solvent solubility into heptane-solubles, heptane-insoluble/toluene-solubles (asphaltenes), and toluene-insolubles (preasphaltenes). The aim of the work was to compare the mass ranges of the different fractions by several different techniques. Thermogravimetric analysis, size-exclusion chromatography (SEC) and UV-fluorescence spectroscopy showed distinct differences between the three fractions in terms of volatility, molecular size ranges and the aromatic chromophore sizes present. The mass spectrometric methods used were gas chromatography/mass spectrometry (GC/MS), pyrolysis/GC/MS, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) and laser desorption time-of-flight mass spectrometry (LD-TOFMS). The first three techniques gave good mass spectra only for the heptane-soluble fraction. Only LDMS gave signals from the toluene-insolubles, indicating that the molecules were too involatile for GC and too complex to pyrolyze into small molecules during pyrolysis/GC/MS. ESI-FTICRMS gave no signal for toluene-insolubles probably because the fraction was insoluble in the methanol or acetonitrile, water and formic acid mixture used as solvent to the ESI source. LDMS was able to generate ions from each of the fractions. Fractionation of complex samples is necessary to separate smaller molecules to allow the use of higher laser fluences for the larger molecules and suppress the formation of ionized molecular clusters. The upper mass limit of the pitch was determined as between 5000 and 10,000 u. The pitch asphaltenes showed a peak of maximum intensity in the LDMS spectra at around m/z 400, in broad agreement with the estimate from SEC. The mass ranges of the toluene-insoluble fraction found by LDMS and SEC (400-10,000 u with maximum intensity around 2000 u by LDMS and 100-9320 u with maximum intensity around 740 u by SEC) are higher than those for the asphaltene fraction (200-4000 u with

  12. Sizing Power Components of an Electrically Driven Tail Cone Thruster and a Range Extender

    Science.gov (United States)

    Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy

    2016-01-01

    The aeronautics industry has been challenged on many fronts to increase efficiency, reduce emissions, and decrease dependency on carbon-based fuels. This paper provides an overview of the turboelectric and hybrid electric technologies being developed under NASA's Advanced Air Transportation Technology (AATT) Project and discusses how these technologies can impact vehicle design. The discussion includes an overview of key hybrid electric studies and technology investments, the approach to making informed investment decisions based on key performance parameters and mission studies, and the power system architectures for two candidate aircraft. Finally, the power components for a single-aisle turboelectric aircraft with an electrically driven tail cone thruster and for a hybrid-electric nine-passenger aircraft with a range extender are parametrically sized, and the sensitivity of these components to key parameters is presented.

  13. Chromosomal diversity in tropical reef fishes is related to body size and depth range.

    Science.gov (United States)

    Martinez, P A; Zurano, J P; Amado, T F; Penone, C; Betancur-R, R; Bidau, C J; Jacobina, U P

    2015-12-01

    Tropical reef fishes show contrasting patterns of karyotypic diversity. Some families have a high chromosomal conservatism while others show wide variation in karyotypic macrostructure. However, the influence of life-history traits on karyotypic diversity is largely unknown. Using phylogenetic comparative methods, we assessed the effects of larval and adult species traits on chromosomal diversity rates of 280 reef species in 24 families. We employed a novel approach to account for trait variation within families as well as phylogenetic uncertainties. We found a strong negative relationship between karyotypic diversity rates and body size and depth range. These results suggest that lineages with higher dispersal potential and gene flow possess lower karyotypic diversity. Taken together, these results provide evidence that biological traits might modulate the rate of karyotypic diversity in tropical reef fishes.

  14. Coarsening dynamics in condensing zero-range processes and size-biased birth death chains

    Science.gov (United States)

    Jatuviriyapornchai, Watthanan; Grosskinsky, Stefan

    2016-05-01

    Zero-range processes with decreasing jump rates are well known to exhibit a condensation transition under certain conditions on the jump rates, and the dynamics of this transition continues to be a subject of current research interest. Starting from homogeneous initial conditions, the time evolution of the condensed phase exhibits an interesting coarsening phenomenon of mass transport between cluster sites characterized by a power law. We revisit the approach in Godrèche (2003 J. Phys. A: Math. Gen. 36 6313) to derive effective single site dynamics which form a nonlinear birth death chain describing the coarsening behavior. We extend these results to a larger class of parameter values, and introduce a size-biased version of the single site process, which provides an effective tool to analyze the dynamics of the condensed phase without finite size effects and is the main novelty of this paper. Our results are based on a few heuristic assumptions and exact computations, and are corroborated by detailed simulation data.

  15. Land use in semi-free ranging Tonkean macaques Macaca tonkeana depends on environmental conditions: A geographical information system approach

    Institute of Scientific and Technical Information of China (English)

    Cédric SUEUR; Paul SALZE; Christiane WEBER; Odile PETIT

    2011-01-01

    Wild animals use their habitat according to ecological pressures such as predaton, resource availability or temperature, yet little is known about how individuals use their environment in semi free-ranging conditions. We assessed whether a semi-free ranging group of Tonkean macaques Macaca tonkeana used its wooded parkland in a heterogeneous way. GIS and GPS were used to determine whether individuals adjusted their behaviors according to variation in environmental constraints over time of day and the course of a year. We demonstrated that social and resting activities occurred in high altitude areas and areas with a high density of bushes, whereas the group foraged in areas where the density of bushes and grass was low. In general, the animals used areas exposed to the sun that were not on a slope. Semi-free ranging Tonkean macaques seemed to behave like their wild counterparts in terms of activity budget, land use per activity and thermoregulation.

  16. Pachyneuridae (Diptera): new data on the geographic range and designation of the lectotype of Pachyneura fasciata Zetterstedt, 1838.

    Science.gov (United States)

    Paramonov, Nikolai M; Salmela, Jukka

    2016-06-02

    All available records of two nematoceran flies Pachyneura fasciata and P. oculata were gathered and mapped. P. fasciata is a wide-ranging Palaearctic species, and is here reported for the first time for some regions of the Russian Federation, including the European part of Russia (Leningrad Oblast), Western Siberia (Tomsk Oblast, Altay Republic), Eastern Siberia (Krasnoyarsk Krai, Irkutsk Oblast, Chita Oblast), the Far East of Russia (Kuril islands, Kunashir and Paramushir Islands), and for continental China. Pachyneura oculata has a restricted eastern Palaearctic range. The lectotype of P. fasciata has been designated and a key for the identification of Pachyneura species is provided.

  17. Biases in grant proposal success rates, funding rates and award sizes affect the geographical distribution of funding for biomedical research.

    Science.gov (United States)

    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.

  18. Biases in grant proposal success rates, funding rates and award sizes affect the geographical distribution of funding for biomedical research

    Directory of Open Access Journals (Sweden)

    Wayne P. Wahls

    2016-04-01

    Full Text Available 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.

  19. Excitation Gaps of Finite-Sized Systems from Optimally Tuned Range-Separated Hybrid Functionals.

    Science.gov (United States)

    Kronik, Leeor; Stein, Tamar; Refaely-Abramson, Sivan; Baer, Roi

    2012-05-08

    Excitation gaps are of considerable significance in electronic structure theory. Two different gaps are of particular interest. The fundamental gap is defined by charged excitations, as the difference between the first ionization potential and the first electron affinity. The optical gap is defined by a neutral excitation, as the difference between the energies of the lowest dipole-allowed excited state and the ground state. Within many-body perturbation theory, the fundamental gap is the difference between the corresponding lowest quasi-hole and quasi-electron excitation energies, and the optical gap is addressed by including the interaction between a quasi-electron and a quasi-hole. A long-standing challenge has been the attainment of a similar description within density functional theory (DFT), with much debate on whether this is an achievable goal even in principle. Recently, we have constructed and applied a new approach to this problem. Anchored in the rigorous theoretical framework of the generalized Kohn-Sham equation, our method is based on a range-split hybrid functional that uses exact long-range exchange. Its main novel feature is that the range-splitting parameter is not a universal constant but rather is determined from first principles, per system, based on satisfaction of the ionization potential theorem. For finite-sized objects, this DFT approach mimics successfully, to the best of our knowledge for the first time, the quasi-particle picture of many-body theory. Specifically, it allows for the extraction of both the fundamental and the optical gap from one underlying functional, based on the HOMO-LUMO gap of a ground-state DFT calculation and the lowest excitation energy of a linear-response time-dependent DFT calculation, respectively. In particular, it produces the correct optical gap for the difficult case of charge-transfer and charge-transfer-like scenarios, where conventional functionals are known to fail. In this perspective, we overview

  20. Conservation genetics of the alligator snapping turtle: cytonuclear evidence of range-wide bottleneck effects and unusually pronounced geographic structure

    Science.gov (United States)

    Echelle, A.A.; Hackler, J.C.; Lack, Justin B.; Ballard, S. R.; Roman, J.; Fox, S. F.; Leslie,, David M.; Van Den Bussche, Ronald A.

    2010-01-01

    A previous mtDNA study indicated that female-mediated gene flow was extremely rare among alligator snapping turtle populations in different drainages of the Gulf of Mexico. In this study, we used variation at seven microsatellite DNA loci to assess the possibility of male-mediated gene flow, we augmented the mtDNA survey with additional sampling of the large Mississippi River System, and we evaluated the hypothesis that the consistently low within-population mtDNA diversity reflects past population bottlenecks. The results show that dispersal between drainages of the Gulf of Mexico is rare (F STmsat  = 0.43, ΦSTmtDNA = 0.98). Past range-wide bottlenecks are indicated by several genetic signals, including low diversity for microsatellites (1.1–3.9 alleles/locus; H e = 0.06–0.53) and mtDNA (h = 0.00 for most drainages; π = 0.000–0.001). Microsatellite data reinforce the conclusion from mtDNA that the Suwannee River population might eventually be recognized as a distinct taxonomic unit. It was the only population showing fixation or near fixation for otherwise rare microsatellite alleles. Six evolutionarily significant units are recommended on the basis of reciprocal mtDNA monophyly and high levels of microsatellite DNA divergence.

  1. The mid-domain effect matters: simulation analyses of range-size distribution data from Mount Kinabalu, Borneo

    DEFF Research Database (Denmark)

    Grytnes, John-Arvid; Beaman, John H.; Romdal, Tom Skovlund;

    2008-01-01

    Aim In simulation exercises, mid-domain peaks in species richness arise as a result of the random placement of modelled species ranges within simulated geometric constraints. This has been called the mid-domain effect (MDE). Where close correspondence is found between such simulations and empirical...... within the domain (range-restricted MDE), and a model encompassing all species with the theoretical midpoint within the domain (midpoint-restricted MDE). These predictions are compared with observations from the elevational pattern of range-size distributions and species richness of vascular plants....... The distribution of range sizes gives different predictions between models including the MDE or not. Here, we produce predictions for species richness and distribution of range sizes from one model without the MDE and from two MDE models: a classical MDE model encompassing only species with their entire range...

  2. Performance of diethylene glycol-based particle counters in the sub-3 nm size range

    CERN Document Server

    Wimmer, D; Franchin, A; Kangasluoma, J; Kreissl, F; Kürten, A; Kupc, A; Metzger, A; Mikkilä, J; Petäjä, J; Riccobono, F; Vanhanen, J; Kulmala, M; Curtius, J

    2013-01-01

    When studying new particle formation, the uncertainty in determining the "true" nucleation rate is considerably reduced when using condensation particle counters (CPCs) capable of measuring concentrations of aerosol particles at sizes close to or even at the critical cluster size (1–2 nm). Recently, CPCs able to reliably detect particles below 2 nm in size and even close to 1 nm became available. Using these instruments, the corrections needed for calculating nucleation rates are substantially reduced compared to scaling the observed formation rate to the nucleation rate at the critical cluster size. However, this improved instrumentation requires a careful characterization of their cut-off size and the shape of the detection efficiency curve because relatively small shifts in the cut-off size can translate into larger relative errors when measuring particles close to the cut-off size. Here we describe the development of two continuous-flow CPCs using diethylene glycol (DEG) as the working fluid. The desig...

  3. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Science.gov (United States)

    Bjornlie, Daniel D; Van Manen, Frank T; Ebinger, Michael R; Haroldson, Mark A; Thompson, Daniel J; Costello, Cecily M

    2014-01-01

    Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  4. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Directory of Open Access Journals (Sweden)

    Daniel D Bjornlie

    Full Text Available Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos in the Greater Yellowstone Ecosystem (GYE, recent decline of whitebark pine (WBP; Pinus albicaulis, an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  5. Meet the parents? Family size and the geographic proximity between adult children and older mothers in Sweden.

    Science.gov (United States)

    Holmlund, Helena; Rainer, Helmut; Siedler, Thomas

    2013-06-01

    The aim of this study is to estimate the causal effect of family size on the proximity between older mothers and adult children by using a large administrative data set from Sweden. Our main results show that adult children in Sweden are not constrained by sibship size in choosing where to live: for families with more than one child, sibship size does not affect child-mother proximity. For aging parents, however, having fewer children reduces the probability of having at least one child living nearby, which is likely to have consequences for the intensity of intergenerational contact and eldercare.

  6. Facilitative Effect of a Generalist Herbivore on the Recovery of a Perennial Alga: Consequences for Persistence at the Edge of Their Geographic Range.

    Directory of Open Access Journals (Sweden)

    Moisés A Aguilera

    Full Text Available Understanding the impacts of consumers on the abundance, growth rate, recovery and persistence of their resources across their distributional range can shed light on the role of trophic interactions in determining species range shifts. Here, we examined if consumptive effects of the intertidal grazer Scurria viridula positively influences the abundance and recovery from disturbances of the alga Mazzaella laminarioides at the edge of its geographic distributions in northern-central Chilean rocky shores. Through field experiments conducted at a site in the region where M. laminarioides overlaps with the polar range edge of S. viridula, we estimated the effects of grazing on different life stages of M. laminarioides. We also used long-term abundance surveys conducted across ~700 km of the shore to evaluate co-occurrence patterns of the study species across their range overlap. We found that S. viridula had positive net effects on M. laminarioides by increasing its cover and re-growth from perennial basal crusts. Probability of occurrence of M. laminarioides increased significantly with increasing density of S. viridula across the range overlap. The negative effect of S. viridula on the percentage cover of opportunistic green algae-shown to compete for space with corticated algae-suggests that competitive release may be part of the mechanism driving the positive effect of the limpet on the abundance and recovery from disturbance of M. laminarioides. We suggest that grazer populations contribute to enhance the abundance of M. laminarioides, facilitating its recolonization and persistence at its distributional range edge. Our study highlights that indirect facilitation can determine the recovery and persistence of a resource at the limit of its distribution, and may well contribute to the ecological mechanisms governing species distributions and range shifts.

  7. Facilitative Effect of a Generalist Herbivore on the Recovery of a Perennial Alga: Consequences for Persistence at the Edge of Their Geographic Range.

    Science.gov (United States)

    Aguilera, Moisés A; Valdivia, Nelson; Broitman, Bernardo R

    2015-01-01

    Understanding the impacts of consumers on the abundance, growth rate, recovery and persistence of their resources across their distributional range can shed light on the role of trophic interactions in determining species range shifts. Here, we examined if consumptive effects of the intertidal grazer Scurria viridula positively influences the abundance and recovery from disturbances of the alga Mazzaella laminarioides at the edge of its geographic distributions in northern-central Chilean rocky shores. Through field experiments conducted at a site in the region where M. laminarioides overlaps with the polar range edge of S. viridula, we estimated the effects of grazing on different life stages of M. laminarioides. We also used long-term abundance surveys conducted across ~700 km of the shore to evaluate co-occurrence patterns of the study species across their range overlap. We found that S. viridula had positive net effects on M. laminarioides by increasing its cover and re-growth from perennial basal crusts. Probability of occurrence of M. laminarioides increased significantly with increasing density of S. viridula across the range overlap. The negative effect of S. viridula on the percentage cover of opportunistic green algae-shown to compete for space with corticated algae-suggests that competitive release may be part of the mechanism driving the positive effect of the limpet on the abundance and recovery from disturbance of M. laminarioides. We suggest that grazer populations contribute to enhance the abundance of M. laminarioides, facilitating its recolonization and persistence at its distributional range edge. Our study highlights that indirect facilitation can determine the recovery and persistence of a resource at the limit of its distribution, and may well contribute to the ecological mechanisms governing species distributions and range shifts.

  8. Researchers' choice of the number and range of levels in experiments affects the resultant variance-accounted-for effect size.

    Science.gov (United States)

    Okada, Kensuke; Hoshino, Takahiro

    2016-08-08

    In psychology, the reporting of variance-accounted-for effect size indices has been recommended and widely accepted through the movement away from null hypothesis significance testing. However, most researchers have paid insufficient attention to the fact that effect sizes depend on the choice of the number of levels and their ranges in experiments. Moreover, the functional form of how and how much this choice affects the resultant effect size has not thus far been studied. We show that the relationship between the population effect size and number and range of levels is given as an explicit function under reasonable assumptions. Counterintuitively, it is found that researchers may affect the resultant effect size to be either double or half simply by suitably choosing the number of levels and their ranges. Through a simulation study, we confirm that this relation also applies to sample effect size indices in much the same way. Therefore, the variance-accounted-for effect size would be substantially affected by the basic research design such as the number of levels. Simple cross-study comparisons and a meta-analysis of variance-accounted-for effect sizes would generally be irrational unless differences in research designs are explicitly considered.

  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?

    Science.gov (United States)

    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. TRANSPORT OF GRAVELS WITH DIFFERENT RANGES OF GRAIN SIZES IN A STEEP CHANNEL

    Institute of Scientific and Technical Information of China (English)

    Jau-Yau LU; Chih-Chiang SU

    2005-01-01

    An understanding of the transport mechanism of gravel-bed rivers is very important for the river management and engineering works. The main objective of this study was to conduct a series of laboratory experiment in a steep flume to investigate the particle segregation and the transport rate of nonuniform gravel. Median sizes of 15 mm and 7.5 mm, and gradation coefficients of 1.5 and 2.0 were selected for the particle size distributions of nonuniform gravel. In addition to the 36 sets of data collected in this study, 635 sets of existing data for gravel with both nonuniform and nearly uniform sizes were analyzed. According to the results of the sieve analysis and the related theory, hiding functions for both particle size distributions of this study were derived. An attempt was made to develop an Einstein-type transport relationship for nonuniform gravel using dimensionless parameters with mean size as a representative particle size. A modified Schoklitsch-type sediment transport equation with a critical unit flow discharge was also developed to reasonably predict the transport rate of gravels. In addition, an artificial neural network (ANN) model with a back-propagation network (BPN) algorithm was also applied in this study.

  11. Home-range size and overlap within an introduced population of the Cuban Knight Anole, Anolis equestris (Squamata: Iguanidae

    Directory of Open Access Journals (Sweden)

    Paul M. Richards

    2011-07-01

    Full Text Available Many studies have investigated the spatial relationships of terrestrial lizards, but arboreal species remain poorly studiedbecause they are difficult to observe. The conventional view of home-range size and overlap among territorial, polygynous species of lizards is that: (1 male home ranges are larger than those of females; (2 male home ranges usually encompass, or substantiallyoverlap, those of several females; and (3 male home-range overlap varies but often is minimal, but female home ranges frequently overlap extensively. However, the paucity of pertinent studies makes it difficult to generalize these patterns to arboreal lizards. Weinvestigated home-range size and overlap in the arboreal Knight Anole, Anolis equestris, and compared our findings to published home-range data for 15 other species of Anolis. Using radiotelemetry and mark-recapture/resight techniques, we analyzed the home rangesof individuals from an introduced population of Knight Anoles in Miami, Florida. The home ranges of both sexes substantially overlapped those of the same- and different-sex individuals. In addition, male and female home ranges did not differ significantly, an unusual observation among lizard species. If one compares both male and female home ranges to those of other Anolis species, Knight Anoles have significantly larger home ranges, except for two species for which statistical comparisons were not possible. Our results suggest that home ranges and sex-specific spatial arrangements of canopy lizards may differ from those of more terrestrial species.

  12. Diversity and geographical distribution of Flavobacterium psychrophilum isolates and their phages: patterns of susceptibility to phage infection and phage host range.

    Science.gov (United States)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio; Middelboe, Mathias

    2014-05-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme analysis (DGREA) and their susceptibility to 33 bacteriophages isolated in Chile and Denmark, thus covering large geographical (>12,000 km) and temporal (>60 years) scales of isolation. An additional 40 phage-resistant isolates obtained from culture experiments after exposure to specific phages were examined for changes in phage susceptibility against the 33 phages. The F. psychrophilum and phage populations isolated from Chile and Denmark clustered into geographically distinct groups with respect to DGREA profile and host range, respectively. However, cross infection between Chilean phage isolates and Danish host isolates and vice versa was observed. Development of resistance to certain bacteriophages led to susceptibility to other phages suggesting that "enhanced infection" is potentially an important cost of resistance in F. psychrophilum, possibly contributing to the observed co-existence of phage-sensitive F. psychrophilum strains and lytic phages across local and global scales. Overall, our results showed that despite the identification of local communities of phages and hosts, some key properties determining phage infection patterns seem to be globally distributed.

  13. Geographical networks: geographical effects on network properties

    Institute of Scientific and Technical Information of China (English)

    Kong-qing YANG; Lei YANG; Bai-hua GONG; Zhong-cai LIN; Hong-sheng HE; Liang HUANG

    2008-01-01

    Complex networks describe a wide range of sys-tems in nature and society. Since most real systems exist in certain physical space and the distance between the nodes has influence on the connections, it is helpful to study geographi-cal complex networks and to investigate how the geographical constrains on the connections affect the network properties. In this paper, we briefly review our recent progress on geo-graphical complex networks with respect of statistics, mod-elling, robustness, and synchronizability. It has been shown that the geographical constrains tend to make the network less robust and less synchronizable. Synchronization on random networks and clustered networks is also studied.

  14. Invasiveness of plants is predicted by size and fecundity in the native range

    DEFF Research Database (Denmark)

    Jelbert, Kim; Stott, Iain; Mcdonald, Robbie A.;

    2015-01-01

    An important goal for invasive species research is to find key traits of species that predispose them to being invasive outside their native range. Comparative studies have revealed phenotypic and demographic traits that correlate with invasiveness among plants. However, all but a few previous st...

  15. Changes in lion (Panthera leo) home range size in Waza National Park, Cameroon

    NARCIS (Netherlands)

    Tumenta, P.N.; Van't Zelfde, M.; Croes, B.M.; Buij, R.; Funston, P.J.; Haes, de H.A.U.; longh, De H.H.

    2013-01-01

    The spatial ecology of Africa lions (Panthera leo) was studied from 2007 to 2009 in Waza National Park, Cameroon, by equipping individual lions with GPS/VHF radio-collars. Mean home range estimates using 100% minimum convex polygons (MCP) and 95% kernel-density estimation (KDE) were respectively

  16. Changes in lion (Panthera leo) home range size in Waza National Park, Cameroon

    NARCIS (Netherlands)

    Tumenta, P.N.; Van't Zelfde, M.; Croes, B.M.; Buij, R.; Funston, P.J.; Haes, de H.A.U.; longh, De H.H.

    2013-01-01

    The spatial ecology of Africa lions (Panthera leo) was studied from 2007 to 2009 in Waza National Park, Cameroon, by equipping individual lions with GPS/VHF radio-collars. Mean home range estimates using 100% minimum convex polygons (MCP) and 95% kernel-density estimation (KDE) were respectively 101

  17. Growth rate and maturation of skeletal muscles over a size range of galliform birds

    NARCIS (Netherlands)

    Dietz, MW; Ricklefs, RE; Ricklefs, Robert E.

    1997-01-01

    The relationship between growth rate and development of function in leg and pectoral muscles was studied in four species of galliform birds ranging from 125 g to 18 kg and, for comparison, in an altricial species, the European starling (80 g). An index to neonatal maturity (muscle dry content propor

  18. On the extent of size range and power law scaling for particles of natural carbonate fault cores

    Science.gov (United States)

    Billi, Andrea

    2007-09-01

    To determine the size range and both type and extent of the scaling laws for particles of loose natural carbonate fault rocks, six granular fault cores from Mesozoic carbonate strata of central Italy were sampled. Particle size distributions of twelve samples were determined by combining sieving and sedimentation methods. Results show that, regardless of the fault geometry, kinematics, and tectonic history, the size of fault rock particles respects a power law distribution across approximately four orders of magnitude. The fractal dimension ( D) of the particle size distribution in the analysed samples ranges between ˜2.0 and ˜3.5. A lower bound to the power law trend is evident in all samples except in those with the highest D-values; in these samples, the smallest analysed particles (˜0.0005 mm in diameter) were also included in the power law interval, meaning that the lower size limit of the power law distribution decreases for increasing D-values and that smallest particles start to be comminuted with increasing strain (i.e. increasing fault displacement and D-values). For increasing D-values, also the largest particles tends to decrease in number, but this evidence may be affected by a censoring bias connected with the sample size. Stick-slip behaviour is suggested for the studied faults on the basis of the inferred particle size evolutions. Although further analyses are necessary to make the results of this study more generalizable, the preliminary definition of the scaling rules for fault rock particles may serve as a tool for predicting a large scale of fault rock particles once a limited range is known. In particular, data from this study may result useful as input numbers in numerical models addressing the packing of fault rock particles for frictional and hydraulic purposes.

  19. Ion generation and CPC detection efficiency studies in sub 3-nm size range

    Energy Technology Data Exchange (ETDEWEB)

    Kangasluoma, J.; Junninen, H.; Sipilae, M.; Kulmala, M.; Petaejae, T. [Department of Physics, P.O. Box 64, 00014, University of Helsinki, Helsinki (Finland); Lehtipalo, K. [Department of Physics, P.O. Box 64, 00014, University of Helsinki, Helsinki (Finland); Airmodus Ltd., Finland, Gustaf Haellstroemin katu 2 A, 00560 Helsinki (Finland); Mikkilae, J.; Vanhanen, J. [Airmodus Ltd., Finland, Gustaf Haellstroemin katu 2 A, 00560 Helsinki (Finland); Attoui, M. [University Paris Est Creteil, University Paris-Diderot, LISA, UMR CNRS 7583 (France); Worsnop, D. [Department of Physics, P.O. Box 64, 00014, University of Helsinki, Helsinki (Finland) and Aerodyne Research Inc., Billerica, MA (United States)

    2013-05-24

    We studied the chemical composition of commonly used condensation particle counter calibration ions with a mass spectrometer and found that in our calibration setup the negatively charged ammonium sulphate, sodium chloride and tungsten oxide are the least contaminated whereas silver on both positive and negative and the three mentioned earlier in positive mode are contaminated with organics. We report cut-off diameters for Airmodus Particle Size Magnifier (PSM) 1.1, 1.3, 1.4, 1.6 and 1.6-1.8 nm for negative sodium chloride, ammonium sulphate, tungsten oxide, silver and positive organics, respectively. To study the effect of sample relative humidity on detection efficiency of the PSM we used different humidities in the differential mobility analyzer sheath flow and found that with increasing relative humidity also the detection efficiency of the PSM increases.

  20. Impact of Global Geographic Region on Time in Therapeutic Range on Warfarin Anticoagulant Therapy: Data From the ROCKET AF Clinical Trial

    Science.gov (United States)

    Singer, Daniel E.; Hellkamp, Anne S.; Piccini, Jonathan P.; Mahaffey, Kenneth W.; Lokhnygina, Yuliya; Pan, Guohua; Halperin, Jonathan L.; Becker, Richard C.; Breithardt, Günter; Hankey, Graeme J.; Hacke, Werner; Nessel, Christopher C.; Patel, Manesh R.; Califf, Robert M.; Fox, Keith A. A.

    2013-01-01

    Background Vitamin K antagonist (VKA) therapy remains the most common method of stroke prevention in patients with atrial fibrillation. Time in therapeutic range (TTR) is a widely cited measure of the quality of VKA therapy. We sought to identify factors associated with TTR in a large, international clinical trial. Methods and Results TTR (international normalized ratio [INR] 2.0 to 3.0) was determined using standard linear interpolation in patients randomized to warfarin in the ROCKET AF trial. Factors associated with TTR at the individual patient level (i‐TTR) were determined via multivariable linear regression. Among 6983 patients taking warfarin, recruited from 45 countries grouped into 7 regions, the mean i‐TTR was 55.2% (SD 21.3%) and the median i‐TTR was 57.9% (interquartile range 43.0% to 70.6%). The mean time with INR 3 was 15.7%. While multiple clinical features were associated with i‐TTR, dominant determinants were previous warfarin use (mean i‐TTR of 61.1% for warfarin‐experienced versus 47.4% in VKA‐naïve patients) and geographic region where patients were managed (mean i‐TTR varied from 64.1% to 35.9%). These effects persisted in multivariable analysis. Regions with the lowest i‐TTRs had INR distributions shifted toward lower INR values and had longer inter‐INR test intervals. Conclusions Independent of patient clinical features, the regional location of medical care is a dominant determinant of variation in i‐TTR in global studies of warfarin. Regional differences in mean i‐TTR are heavily influenced by subtherapeutic INR values and are associated with reduced frequency of INR testing. Clinical Trial Registration URL: ClinicalTrials.gov. Unique identifier: NCT00403767. PMID:23525418

  1. Size effect on high temperature variable range hopping in Al+ implanted 4H-SiC

    Science.gov (United States)

    Parisini, Antonella; Parisini, Andrea; Nipoti, Roberta

    2017-01-01

    The hole transport properties of heavily doped 4H-SiC (Al) layers with Al implanted concentrations of 3  ×  1020 and 5  ×  1020 cm-3 and annealed in the temperature range 1950-2100 °C, have been analyzed to determine the main transport mechanisms. This study shows that the temperature dependence of the resistivity (conductivity) may be accounted for by a variable range hopping (VRH) transport into an impurity band. Depending on the concentration of the implanted impurities and the post-implantation annealing treatment, this VRH mechanism persists over different temperature ranges that may extend up to room temperature. In this framework, two different transport regimes are identified, having the characteristic of an isotropic 3D VRH and an anisotropic nearly 2D VRH. The latter conduction mechanism appears to take place in a rather thick layer (about 400 nm) that is too large to induce a confinement effect of the carrier hops. The possibility that an anisotropic transport may be induced by a structural modification of the implanted layer because of a high density of basal plane stacking faults (SF) in the implanted layers is considered. The interpretation of the conduction in the heaviest doped samples in terms of nearly 2D VRH is supported by the results of the transmission electron microscopy (TEM) investigation on one of the 5  ×  1020 cm-3 Al implanted samples of this study. In this context, the average separation between basal plane SFs, measured along the c-axis, which is orthogonal to the carrier transport during electrical characterization, appears to be in keeping with the estimated value of the optimal hopping length of the VRH theory. Conversely, no SFs are detected by TEM in a sample with an Al concentration of 1  ×  1019 cm-3 where a 3D nearest neighbor hopping (NNH) transport is observed.

  2. Eigenvectors and scalar products for long range interacting spin chains II: the finite size effects

    CERN Document Server

    Serban, D

    2013-01-01

    In this note, we study the eigenvectors and the scalar products the integrable long-range deformation of a XXX spin chain which is solved exactly by algebraic Bethe ansatz, and it coincides in the bulk with the Inozemtsev spin chain. At the closing point it contains a defect which effectively removes the wrapping interactions. Here we concentrate on determining the defect term for the first non-trivial order in perturbation in the deformation parameter and how it affects the Bethe ansatz equations. Our study is motivated by the relation with the dilatation operator of the N = 4 gauge theory in the su(2) sector.

  3. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Directory of Open Access Journals (Sweden)

    Jorge E Ramos

    Full Text Available Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  4. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Science.gov (United States)

    Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  5. Soil Survey Geographic (SSURGO) database for White Sands Missile Range, New Mexico, Parts of Dona Ana, Lincoln, Otero, Sierra and Socorro Counties

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  6. Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of

    Science.gov (United States)

    1979-01-01

    Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of earth's moon, is apparently covered by water ice, as indicated by ground spectrometers and its brightness. In this view, global scale dark sreaks discovered by Voyager 1 that criss-cross the the satelite are becoming visible. Bright rayed impact craters, which are abundant on Ganymede and Callisto, would be easily visible at this range, suggesting that Europa's surface is young and that the streaks are reflections of currently active internal dynamic processes.

  7. Optimizing battery sizes of plug-in hybrid and extended range electric vehicles for different user types

    OpenAIRE

    REDELBACH Martin; Özdemir, Enver Doruk; Friedrich, Horst E.

    2014-01-01

    There are ambitious greenhouse gas emissions (GHG) targets for the manufacturers of light duty vehicles. To reduce the GHG emissions, plug-in hybrid electric vehicle (PHEV) and extended range electric vehicle (EREV) are promising powertrain technologies. However, the battery is still a very critical component due to the high production cost and heavy weight. This paper introduces a holistic approach for the optimization of the battery size of PHEVs and EREVs under German market conditions. Th...

  8. Geographic Names

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Geographic Names Information System (GNIS), developed by the United States Geological Survey in cooperation with the U.S. Board of Geographic Names, provides...

  9. Predator size - prey size relationships of marine fish predators: interspecific variation and effects of ontogeny and body size on trophic-niche breadth

    National Research Council Canada - National Science Library

    Frederick S. Scharf; Francis Juanes; Rodney A. Rountree

    2000-01-01

    We utilized a long-term data base collected over a broad geographic range to examine predator size - prey size relationships for 18 species of marine fish predators from continental shelf waters off...

  10. Particle size reduction to the nanometer range: a promising approach to improve buccal absorption of poorly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Rao S

    2011-06-01

    Full Text Available Shasha Rao, Yunmei Song, Frank Peddie, Allan M EvansSansom Institute for Health Research, Division of Health Sciences, University of South Australia, Adelaide, South Australia, AustraliaAbstract: Poorly water-soluble drugs, such as phenylephrine, offer challenging problems for buccal drug delivery. In order to overcome these problems, particle size reduction (to the nanometer range and cyclodextrin complexation were investigated for permeability enhancement. The apparent solubility in water and the buccal permeation of the original phenylephrine coarse powder, a phenylephrine–cyclodextrin complex and phenylephrine nanosuspensions were ­characterized. The particle size and particle surface properties of phenylephrine nanosuspensions were used to optimize the size reduction process. The optimized phenylephrine nanosuspension was then freeze dried and incorporated into a multi-layered buccal patch, consisting of a small tablet adhered to a mucoadhesive film, yielding a phenylephrine buccal product with good dosage accuracy and improved mucosal permeability. The design of the buccal patch allows for drug incorporation without the need to change the mucoadhesive component, and is potentially suited to a range of poorly water-soluble compounds.Keywords: buccal drug delivery, nanosuspension, solubility, permeation enhancement, mucoadhesion

  11. Training set size, scale, and features in Geographic Object-Based Image Analysis of very high resolution unmanned aerial vehicle imagery

    Science.gov (United States)

    Ma, Lei; Cheng, Liang; Li, Manchun; Liu, Yongxue; Ma, Xiaoxue

    2015-04-01

    Unmanned Aerial Vehicle (UAV) has been used increasingly for natural resource applications in recent years due to their greater availability and the miniaturization of sensors. In addition, Geographic Object-Based Image Analysis (GEOBIA) has received more attention as a novel paradigm for remote sensing earth observation data. However, GEOBIA generates some new problems compared with pixel-based methods. In this study, we developed a strategy for the semi-automatic optimization of object-based classification, which involves an area-based accuracy assessment that analyzes the relationship between scale and the training set size. We found that the Overall Accuracy (OA) increased as the training set ratio (proportion of the segmented objects used for training) increased when the Segmentation Scale Parameter (SSP) was fixed. The OA increased more slowly as the training set ratio became larger and a similar rule was obtained according to the pixel-based image analysis. The OA decreased as the SSP increased when the training set ratio was fixed. Consequently, the SSP should not be too large during classification using a small training set ratio. By contrast, a large training set ratio is required if classification is performed using a high SSP. In addition, we suggest that the optimal SSP for each class has a high positive correlation with the mean area obtained by manual interpretation, which can be summarized by a linear correlation equation. We expect that these results will be applicable to UAV imagery classification to determine the optimal SSP for each class.

  12. Feasibility Study of Interstellar Missions Using Laser Sail Probes Ranging in Size from the Nano to the Macro

    Science.gov (United States)

    Malroy, Eric T.

    2010-01-01

    This paper presents the analysis examining the feasibility of interstellar travel using laser sail probes ranging in size from the nano to the macro. The relativistic differential equations of motion for a laser sail are set up and solved using the Pasic Method. The limitations of the analysis are presented and discussed. The requirements for the laser system are examined, including the thermal analysis of the laser sails. Black holes, plasma fields, atmospheric collisions and sun light are several methods discussed to enable the deceleration of the interstellar probe. A number of novel mission scenarios are presented including the embryonic transport of plant life as a precursor to the arrival of space colonies

  13. Free-ranging male koalas use size-related variation in formant frequencies to assess rival males.

    Directory of Open Access Journals (Sweden)

    Benjamin D Charlton

    Full Text Available Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals.

  14. Free-ranging male koalas use size-related variation in formant frequencies to assess rival males.

    Science.gov (United States)

    Charlton, Benjamin D; Whisson, Desley A; Reby, David

    2013-01-01

    Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals.

  15. Silage Collected from Dairy Farms Harbors an Abundance of Listeriaphages with Considerable Host Range and Genome Size Diversity

    Science.gov (United States)

    Vongkamjan, Kitiya; Switt, Andrea Moreno; den Bakker, Henk C.; Fortes, Esther D.

    2012-01-01

    Since the food-borne pathogen Listeria monocytogenes is common in dairy farm environments, it is likely that phages infecting this bacterium (“listeriaphages”) are abundant on dairy farms. To better understand the ecology and diversity of listeriaphages on dairy farms and to develop a diverse phage collection for further studies, silage samples collected on two dairy farms were screened for L. monocytogenes and listeriaphages. While only 4.5% of silage samples tested positive for L. monocytogenes, 47.8% of samples were positive for listeriaphages, containing up to >1.5 × 104 PFU/g. Host range characterization of the 114 phage isolates obtained, with a reference set of 13 L. monocytogenes strains representing the nine major serotypes and four lineages, revealed considerable host range diversity; phage isolates were classified into nine lysis groups. While one serotype 3c strain was not lysed by any phage isolates, serotype 4 strains were highly susceptible to phages and were lysed by 63.2 to 88.6% of phages tested. Overall, 12.3% of phage isolates showed a narrow host range (lysing 1 to 5 strains), while 28.9% of phages represented broad host range (lysing ≥11 strains). Genome sizes of the phage isolates were estimated to range from approximately 26 to 140 kb. The extensive host range and genomic diversity of phages observed here suggest an important role of phages in the ecology of L. monocytogenes on dairy farms. In addition, the phage collection developed here has the potential to facilitate further development of phage-based biocontrol strategies (e.g., in silage) and other phage-based tools. PMID:23042180

  16. Processing and size range separation of pristine and magnetic poly(l-lactic acid) based microspheres for biomedical applications.

    Science.gov (United States)

    Correia, D M; Sencadas, V; Ribeiro, C; Martins, P M; Martins, P; Gama, F M; Botelho, G; Lanceros-Méndez, S

    2016-08-15

    Biodegradable poly(l-lactic acid) (PLLA) and PLLA/CoFe2O4 magnetic microspheres with average sizes ranging between 0.16-3.9μm and 0.8-2.2μm, respectively, were obtained by an oil-in-water emulsion method using poly(vinyl alcohol) (PVA) solution as the emulsifier agent. The separation of the microspheres in different size ranges was then performed by centrifugation and the colloidal stability assessed at different pH values. Neat PLLA spheres are more stable in alkaline environments when compared to magnetic microspheres, both types being stable for pHs higher than 4, resulting in a colloidal suspension. On the other hand, in acidic environments the microspheres tend to form aggregates. The neat PLLA microspheres show a degree of crystallinity of 40% whereas the composite ones are nearly amorphous (17%). Finally, the biocompatibility was assessed by cell viability studies with MC3T3-E1 pre-osteoblast cells.

  17. Experimental validation of the intrinsic spatial efficiency method over a wide range of sizes for cylindrical sources

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Ramŕez, Pablo, E-mail: rapeitor@ug.uchile.cl; Larroquette, Philippe [Departamento de Física, Facultad de Ciencias, Universidad de Chile (Chile); Camilla, S. [Departamento de Física, Universidad Tecnológica Metropolitana (Chile)

    2016-07-07

    The intrinsic spatial efficiency method is a new absolute method to determine the efficiency of a gamma spectroscopy system for any extended source. In the original work the method was experimentally demonstrated and validated for homogeneous cylindrical sources containing {sup 137}Cs, whose sizes varied over a small range (29.5 mm radius and 15.0 to 25.9 mm height). In this work we present an extension of the validation over a wide range of sizes. The dimensions of the cylindrical sources vary between 10 to 40 mm height and 8 to 30 mm radius. The cylindrical sources were prepared using the reference material IAEA-372, which had a specific activity of 11320 Bq/kg at july 2006. The obtained results were better for the sources with 29 mm radius showing relative bias lesser than 5% and for the sources with 10 mm height showing relative bias lesser than 6%. In comparison with the obtained results in the work where we present the method, the majority of these results show an excellent agreement.

  18. 引入投影散斑尺寸配准的地理遥感标定技术%Geographical Remote Calibration Technology Introduced into Projection Speckle Size Registration

    Institute of Scientific and Technical Information of China (English)

    时峰

    2015-01-01

    In the geographical position calibration and 3D map building process, usually adopts the method of calibration of remote sensing position. Geographical remote calibration method using edge detection and watershed segmentation marker is researched, when the geographical space appearance of spots of non significant transition when the calibration effect is not good. Proposes a projection Geographical remote calibration technique of speckle size based on registration. Using the projection speckle size registration techniques, calculation of projection speckle size information and retain the stability of Harris corner detection algorithm, algorithm fusion the characteristics of SURF algorithm is scale invariant, improve the Geographical remote calibration feature matching accuracy and efficiency. The simulation results show that using the pro-jection Geographical remote calibration technique of speckle size based on registration, has strong anti-interference perfor-mance, the calibration of remote sensing characteristics of geographic point accurately, repeat the point less, algorithm to scale, illumination and noise robustness of geographic information of remote sensing, it improves the registration accuracy and speed.%在地理位置标定和三维地图创建过程中,通常采用远程遥感位置标定方法.传统的地理遥感标定采用边缘检测和分水岭分割标记的方法,当地理空间色斑出现非显著性过渡时,标定效果不好.提出一种基于投影散斑尺寸配准的地理遥感标定技术.采用投影散斑尺寸配准技术,去除地表植被的色斑出现非显著性过渡干扰.保留了Harris角点检测算法的稳定性,算法融合了SURF算法尺度不变的特性,提高了地理遥感标定特征匹配精度和效率.仿真结果表明,采用该基于投影散斑尺寸配准的地理遥感标定技术,具有较强的抗干扰性能,对地理遥感特征点的标定准确,重复点较少,算法对尺度、光照及噪声

  19. A QVGA-size CMOS time-of-flight range image sensor with background light charge draining structure

    Science.gov (United States)

    Ushinaga, Takeo; Halin, Izhal Abdul; Sawada, Tomonari; Kawahito, Shoji; Homma, Mitsuru; Maeda, Yasunari

    2006-02-01

    3-D imaging systems can be used in a variety of applications such as in automobile, medicine, robot vision systems, security and so on. Recently many kinds of range finding methods have been proposed for 3-D imaging systems. This paper presents a new type of CMOS range image sensor based on the Time-of-Flight (TOF)principle with a spatial resolution of 336 × 252 (QVGA) and pixels of 15 × 15 μm2 size. A pixel structure of the sensor consists of single layer polysilicon gates on thick field oxide and has a function of background light induced charge reduction. The chip was fabricated in a 0.35 μm standard CMOS process with two poly and three metal layers. The presented sensor achieves a minimum range resolution of 2.8cm at framerate of 30fps and the resolution is improved to 4.2mm for 10 frames averaging, which corresponds to 3fps.

  20. The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles

    Directory of Open Access Journals (Sweden)

    Daniel J Cooney

    2008-08-01

    Full Text Available Daniel J Cooney1, Anthony J Hickey21Department of Biomedical Engineering; 2School of Pharmacy, University of North Carolina, Chapel Hill, NC, USAAbstract: The influence of diesel exhaust particles (DEP on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene in the particles resulting from the aerosolization process.Keywords: diesel exhaust particles, aerosol, inhalation toxicology

  1. Geographic Tongue

    Science.gov (United States)

    ... 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 ...

  2. 乌饭树果实大小的地理变异研究%Study on geographic variation of fruit sizes in Vaccinium bracteatum

    Institute of Scientific and Technical Information of China (English)

    刘仁林; 胡明娇; 李江; 刘江华

    2016-01-01

    Vaccinium bracteatum distributes widely in subtropical hilly and low mountains areas of China. Berry in V. bracteatum is a nutrition-rich and healthful food, and is most commonly used to eat as a traditional food in Chinese folks. In order to provide some scientific basis for selecting an breeding in V. bracteatum, fruits were collected from Jiangxi province (Huichang, Longnan, Ruijin, Jinggang Mountain, Pingxiang), Hunan province (Liuyang), and Jiangsu province (Yixing), fruit sizes and mass were determined, and the law of geographic variation was analyzed. The results showed that the fruit was of a type of small berry, average diameter of fruits was 0.790 2 cm, average mass of 1 000 seeds was 0.698 g. Diameter (y) and mass (x) of the fruit had significant relation of linear regression, and the equation was y = 0.603x -0.241. The results of variance analysis showed that sizes of the mixed fruits had no obvious differences among the areas at different latitudes, and fruit sizes from superior trees had significant differences among the areas at different latitudes, which indicated individual plant in V. bracteatum had a independent inheritance background. The results of multiple linear regression analysis showed that sizes of the mixed fruits collected from different latitudes had no significant linear regression relation with environment factors, and fruit sizes from superior trees had significant multiple linear regression relation with environment factors, for example, annual average temperature (x2) and frost free period (x4), and the linear regression equation was y = - 0.038x2 + 0.004x4 + 0.674. In a word, selecting and breeding of V. bracteatum plants with large fruit type should paid attention to the areas of Jinggang Mountain, Longnan and Pingxiang.%乌饭树广泛分布于我国亚热带丘陵—低山地区,是中国民间传统的健康食品“乌饭”的原料,其浆果酸甜可口,营养丰富,含有多种有益于人体健康的成分。为

  3. Source apportionment of wide range particle size spectra and black carbon collected at the airport of Venice (Italy)

    Science.gov (United States)

    Masiol, Mauro; Vu, Tuan V.; Beddows, David C. S.; Harrison, Roy M.

    2016-08-01

    Atmospheric particles are of high concern due to their toxic properties and effects on climate, and large airports are known as significant sources of particles. This study investigates the contribution of the Airport of Venice (Italy) to black carbon (BC), total particle number concentrations (PNC) and particle number size distributions (PNSD) over a large range (14 nm-20 μm). Continuous measurements were conducted between April and June 2014 at a site located 110 m from the main taxiway and 300 m from the runway. Results revealed no significantly elevated levels of BC and PNC, but exhibited characteristic diurnal profiles. PNSD were then analysed using both k-means cluster analysis and positive matrix factorization. Five clusters were extracted and identified as midday nucleation events, road traffic, aircraft, airport and nighttime pollution. Six factors were apportioned and identified as probable sources according to the size profiles, directional association, diurnal variation, road and airport traffic volumes and their relationships to micrometeorology and common air pollutants. Photochemical nucleation accounted for ∼44% of total number, followed by road + shipping traffic (26%). Airport-related emissions accounted for ∼20% of total PNC and showed a main mode at 80 nm and a second mode beyond the lower limit of the SMPS (pollution and local resuspension. An analysis of BC levels over different wind sectors revealed no especially significant contributions from specific directions associated with the main local sources, but a potentially significant role of diurnal dynamics of the mixing layer on BC levels. The approaches adopted in this study have identified and apportioned the main sources of particles and BC at an international airport located in area affected by a complex emission scenario. The results may underpin measures for improving local and regional air quality, and health impact assessment studies.

  4. Evaluation of size segregation of elemental carbon emission in Europe: influence on atmospheric long-range transportation

    Directory of Open Access Journals (Sweden)

    Y. Chen

    2015-11-01

    Full Text Available Elemental Carbon (EC has significant impact on human health and climate change. In order to evaluate the size segregation of EC emission and investigation of its influence on atmospheric transport processes in Europe, we used the fully coupled online Weather Research and Forecasting/Chemistry model (WRF-Chem at a resolution of 2 km focusing on a region in Germany, in conjunction with a high-resolution EC emission inventory. The ground meteorology conditions, vertical structure and wind pattern were well reproduced by the model. The simulations of particle number/mass size distributions were evaluated by observations taken at the central European background site Melpitz. The fine mode aerosol was reasonably well simulated, but the coarse mode was substantially overestimated by the model. We found that it was mainly due to the nearby point source plume emitting a high amount of EC in the coarse mode. The comparisons between simulated EC and Multi-angle Absorption Photometers (MAAP measurements at Melpitz, Leipzig-TROPOS and Bösel indicated that coarse mode EC (ECc emission in the nearby point sources might be overestimated by a factor of 2–10. The emission fraction of EC in coarse mode was overestimated by about 10–30 % for Russian and 5–10 % for Eastern Europe (e.g.: Poland and Belarus, respectively. This overestimation in ECc emission fraction makes EC particles having less opportunity to accumulate in the atmosphere and participate to the long range transport, due to the shorter lifetime of coarse mode aerosol. The deposition concept model showed that the transported EC mass from Warsaw and Moskva to Melpitz may be reduced by 25–35 and 25–55 % respectively, due to the overestimation of ECc emission fraction. This may partly explain the underestimation of EC concentrations for Germany under eastern wind pattern in some other modelling research.

  5. Evaluation of size segregation of elemental carbon emission in Europe: influence on atmospheric long-range transportation

    Science.gov (United States)

    Chen, Y.; Cheng, Y. F.; Nordmann, S.; Birmili, W.; Denier van der Gon, H. A. C.; Ma, N.; Wolke, R.; Wehner, B.; Sun, J.; Spindler, G.; Mu, Q.; Pöschl, U.; Su, H.; Wiedensohler, A.

    2015-11-01

    Elemental Carbon (EC) has significant impact on human health and climate change. In order to evaluate the size segregation of EC emission and investigation of its influence on atmospheric transport processes in Europe, we used the fully coupled online Weather Research and Forecasting/Chemistry model (WRF-Chem) at a resolution of 2 km focusing on a region in Germany, in conjunction with a high-resolution EC emission inventory. The ground meteorology conditions, vertical structure and wind pattern were well reproduced by the model. The simulations of particle number/mass size distributions were evaluated by observations taken at the central European background site Melpitz. The fine mode aerosol was reasonably well simulated, but the coarse mode was substantially overestimated by the model. We found that it was mainly due to the nearby point source plume emitting a high amount of EC in the coarse mode. The comparisons between simulated EC and Multi-angle Absorption Photometers (MAAP) measurements at Melpitz, Leipzig-TROPOS and Bösel indicated that coarse mode EC (ECc) emission in the nearby point sources might be overestimated by a factor of 2-10. The emission fraction of EC in coarse mode was overestimated by about 10-30 % for Russian and 5-10 % for Eastern Europe (e.g.: Poland and Belarus), respectively. This overestimation in ECc emission fraction makes EC particles having less opportunity to accumulate in the atmosphere and participate to the long range transport, due to the shorter lifetime of coarse mode aerosol. The deposition concept model showed that the transported EC mass from Warsaw and Moskva to Melpitz may be reduced by 25-35 and 25-55 % respectively, due to the overestimation of ECc emission fraction. This may partly explain the underestimation of EC concentrations for Germany under eastern wind pattern in some other modelling research.

  6. Invasive alien plants in Croatia as a threat to biodiversity of South-Eastern Europe: distributional patterns and range size.

    Science.gov (United States)

    Nikolić, Toni; Mitić, Božena; Milašinović, Boris; Jelaska, Sven D

    2013-02-01

    During the analysis of alien and invasive flora of Europe, as a threat to biodiversity, data for Croatia were missing. The aim of our research was to analyse distributional patterns and range size of all invasive alien plants (64) for the state area (57,000 km(2)). They were detected on 49% of the state territory, averaging five taxa per 35 km(2). The greatest number of invasive plants (>30 per grid cell) was recorded in the major urban centres, increasing in the south-east direction and reflecting positive correlation with temperature and negative with altitude. The most endangered areas are in the Mediterranean region, especially on islands. The number of invasive plants increased with habitat diversity and almost 75% of all sites with invasive plants are located within a few habitats with direct anthropogenic influence. The results should provide a reliable regional and global basis for strategic planning regarding invasive alien plants management. Copyright © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  7. Shared genetic diversity across the global invasive range of the monk parakeet suggests a common restricted geographic origin and the possibility of convergent selection.

    Science.gov (United States)

    Edelaar, Pim; Roques, Severine; Hobson, Elizabeth A; Gonçalves da Silva, Anders; Avery, Michael L; Russello, Michael A; Senar, Juan C; Wright, Timothy F; Carrete, Martina; Tella, José L

    2015-05-01

    While genetic diversity is hypothesized to be an important factor explaining invasion success, there is no consensus yet on how variation in source populations or demographic processes affects invasiveness. We used mitochondrial DNA haplotypic and microsatellite genotypic data to investigate levels of genetic variation and reconstruct the history of replicate invasions on three continents in a globally invasive bird, the monk parakeet (Myiopsitta monachus). We evaluated whether genetic diversity at invasive sites could be explained by (i) the native source populations from which they were derived and (ii) demographic bottlenecks during introduction. Genetic data indicated a localized source area for most sampled invasive populations, with limited evidence for admixing of native source populations. This pattern largely coincides with historical data on pet trade exports. However, the invasive populations are genetically more similar than predicted from the export data alone. The extent of bottleneck effects varied among invasive populations. The observed low genetic diversity, evidence of demographic contraction and restricted source area do not support the hypothesis that invasion is favoured by the mixing and recombining of genetic variation from multiple source populations. Instead, they suggest that reduced genetic variation through random processes may not inhibit successful establishment and invasion in this species. However, convergent selection across invasive sites could also explain the observed patterns of reduction and similarity in genetic variation and/or the restricted source area. In general, the alternative explanation of intraspecific variation in invasive potential among genotypes or geographic areas is neglected, but warrants more attention as it could inform comparative studies and management of biological invaders. © 2015 John Wiley & Sons Ltd.

  8. Detection of unlabeled particles in the low micrometer size range using light scattering and hydrodynamic 3D focusing in a microfluidic system

    DEFF Research Database (Denmark)

    Zhuang, Guisheng; Jensen, Thomas G.; Kutter, Jörg P.

    2012-01-01

    In this paper, we describe a microfluidic device composed of integrated microoptical elements and a two‐layer microchannel structure for highly sensitive light scattering detection of micro/submicrometer‐sized particles. In the two‐layer microfluidic system, a sample flow stream is first constrai...... of Reynolds numbers (0.5 micrometer size range by light scattering detection....

  9. Information and redundancy in the burial folding code of globular proteins within a wide range of shapes and sizes.

    Science.gov (United States)

    Ferreira, Diogo C; van der Linden, Marx G; de Oliveira, Leandro C; Onuchic, José N; de Araújo, Antônio F Pereira

    2016-04-01

    Recent ab initio folding simulations for a limited number of small proteins have corroborated a previous suggestion that atomic burial information obtainable from sequence could be sufficient for tertiary structure determination when combined to sequence-independent geometrical constraints. Here, we use simulations parameterized by native burials to investigate the required amount of information in a diverse set of globular proteins comprising different structural classes and a wide size range. Burial information is provided by a potential term pushing each atom towards one among a small number L of equiprobable concentric layers. An upper bound for the required information is provided by the minimal number of layers L(min) still compatible with correct folding behavior. We obtain L(min) between 3 and 5 for seven small to medium proteins with 50 ≤ Nr ≤ 110 residues while for a larger protein with Nr = 141 we find that L ≥ 6 is required to maintain native stability. We additionally estimate the usable redundancy for a given L ≥ L(min) from the burial entropy associated to the largest folding-compatible fraction of "superfluous" atoms, for which the burial term can be turned off or target layers can be chosen randomly. The estimated redundancy for small proteins with L = 4 is close to 0.8. Our results are consistent with the above-average quality of burial predictions used in previous simulations and indicate that the fraction of approachable proteins could increase significantly with even a mild, plausible, improvement on sequence-dependent burial prediction or on sequence-independent constraints that augment the detectable redundancy during simulations.

  10. Evolution of enlarged body size of coal tits Parus ater in geographic isolation from two larger competitors, the crested tit Parus cristatus and the willow tit Parus montanus, on six Scandinavian islands

    Science.gov (United States)

    Norberg, R. Åke; Lindhe Norberg, Ulla M.

    2015-01-01

    ABSTRACT Here, we report that on six widely separated Scandinavian islands, the coal tit Parus ater has evolved morphologically in the direction of two absent competitors, the crested tit P. cristatus and the willow tit P. montanus, to the effect that it is up to 10% larger in linear dimensions than conspecifics on the adjacent Swedish mainland, where all three species coexist. The large size is genetically determined, as ascertained by clutch exchange experiments between island and mainland nests. We conclude that the increased size of P. ater in places where it is geographically isolated from its larger congeners is the result of evolutionary adaptation, due ultimately to relaxed interspecific competition. On the islands, P. ater has evolved into a medium-sized generalist, with selection pressures likely governed by the following causal relationships. When competitors are lacking, P. ater takes over the foraging space of the absentees. The enlarged food base allows higher population densities, which intensifies intraspecific interference competition. This, in turn, selects for increased body size. When P. ater coexists with its larger congeners, it occupies peripheral foraging sites in trees, which requires excellent manoeuvrability and energy-expensive locomotion modes. Reduction of body size increases locomotor capacity for mechanical and aerodynamic reasons and lowers energy consumption, so small size is favoured in sympatry. But in geographic isolation, P. ater exploits the tree periphery less and the inner tree regions more, and it also adopts the easier locomotion modes of the absent species. Therefore, selection for manoeuvrability and a small body size is relaxed. The new selection regime shifts the balance between opposing selection forces towards a larger body size. We were able to test 11 alternative hypotheses and available evidence conclusively eliminates them all. As a result, here, evolution could be predicted regarding both direction and amount of

  11. Evolution of enlarged body size of coal tits Parus ater in geographic isolation from two larger competitors, the crested tit Parus cristatus and the willow tit Parus montanus, on six Scandinavian islands

    Directory of Open Access Journals (Sweden)

    R. Åke Norberg

    2015-11-01

    Full Text Available Here, we report that on six widely separated Scandinavian islands, the coal tit Parus ater has evolved morphologically in the direction of two absent competitors, the crested tit P. cristatus and the willow tit P. montanus, to the effect that it is up to 10% larger in linear dimensions than conspecifics on the adjacent Swedish mainland, where all three species coexist. The large size is genetically determined, as ascertained by clutch exchange experiments between island and mainland nests. We conclude that the increased size of P. ater in places where it is geographically isolated from its larger congeners is the result of evolutionary adaptation, due ultimately to relaxed interspecific competition. On the islands, P. ater has evolved into a medium-sized generalist, with selection pressures likely governed by the following causal relationships. When competitors are lacking, P. ater takes over the foraging space of the absentees. The enlarged food base allows higher population densities, which intensifies intraspecific interference competition. This, in turn, selects for increased body size. When P. ater coexists with its larger congeners, it occupies peripheral foraging sites in trees, which requires excellent manoeuvrability and energy-expensive locomotion modes. Reduction of body size increases locomotor capacity for mechanical and aerodynamic reasons and lowers energy consumption, so small size is favoured in sympatry. But in geographic isolation, P. ater exploits the tree periphery less and the inner tree regions more, and it also adopts the easier locomotion modes of the absent species. Therefore, selection for manoeuvrability and a small body size is relaxed. The new selection regime shifts the balance between opposing selection forces towards a larger body size. We were able to test 11 alternative hypotheses and available evidence conclusively eliminates them all. As a result, here, evolution could be predicted regarding both direction

  12. Evolution of enlarged body size of coal tits Parus ater in geographic isolation from two larger competitors, the crested tit Parus cristatus and the willow tit Parus montanus, on six Scandinavian islands.

    Science.gov (United States)

    Norberg, R Åke; Lindhe Norberg, Ulla M

    2015-10-21

    Here, we report that on six widely separated Scandinavian islands, the coal tit Parus ater has evolved morphologically in the direction of two absent competitors, the crested tit P. cristatus and the willow tit P. montanus, to the effect that it is up to 10% larger in linear dimensions than conspecifics on the adjacent Swedish mainland, where all three species coexist. The large size is genetically determined, as ascertained by clutch exchange experiments between island and mainland nests. We conclude that the increased size of P. ater in places where it is geographically isolated from its larger congeners is the result of evolutionary adaptation, due ultimately to relaxed interspecific competition. On the islands, P. ater has evolved into a medium-sized generalist, with selection pressures likely governed by the following causal relationships. When competitors are lacking, P. ater takes over the foraging space of the absentees. The enlarged food base allows higher population densities, which intensifies intraspecific interference competition. This, in turn, selects for increased body size. When P. ater coexists with its larger congeners, it occupies peripheral foraging sites in trees, which requires excellent manoeuvrability and energy-expensive locomotion modes. Reduction of body size increases locomotor capacity for mechanical and aerodynamic reasons and lowers energy consumption, so small size is favoured in sympatry. But in geographic isolation, P. ater exploits the tree periphery less and the inner tree regions more, and it also adopts the easier locomotion modes of the absent species. Therefore, selection for manoeuvrability and a small body size is relaxed. The new selection regime shifts the balance between opposing selection forces towards a larger body size. We were able to test 11 alternative hypotheses and available evidence conclusively eliminates them all. As a result, here, evolution could be predicted regarding both direction and amount of change.

  13. Autecological traits determined two evolutionary strategies in Mediterranean plants during the Quaternary: low differentiation and range expansion versus geographical speciation in Linaria.

    Science.gov (United States)

    Blanco-Pastor, J L; Vargas, P

    2013-11-01

    The evolutionary patterns of the Mediterranean flora during the Quaternary have been relatively well documented based on phylogenetic and biogeographic analyses, but few studies have addressed the evolutionary traits that determined diversification and range expansion success during this period. We analysed previously published and newly generated sequences of three plastid noncoding regions (rpl32-trnL(UAG) , trnS-trnG and trnL-trnF), the nuclear ribosomal internal transcribed spacer (ITS) and a low-copy nuclear gene intron (AGT1) of Linaria sect. Supinae, a group of angiosperms that diversified in the Quaternary. The origin and recent colonization dynamics of closely related lineages were inferred by biogeographic reconstruction and phylogeographic analyses, while breeding system experiments coupled with ecological and morphological data were used to test association with range expansion and diversification. A combination of traits, including selfing, short lifespan and the ability to tolerate a wide variety of substrates, were key factors underlying range expansion after long-distance dispersal throughout the Mediterranean basin. By contrast, self-incompatibility may have promoted higher diversification rates in narrow ranges of the Iberian Peninsula. We argue that a few traits contributed to the adoption of two contrasting strategies that may have been predominant in the evolution of Mediterranean angiosperms. © 2013 John Wiley & Sons Ltd.

  14. Extremos geográficos de la distribución natural de Austrocedrus chilensis (Cupressaceae Geographic extremes of the natural range of Austrocedrus chilensis (Cupressaceae

    Directory of Open Access Journals (Sweden)

    Mario J. Pastorino

    2006-12-01

    Full Text Available El "Ciprés de la Cordillera " ( Austrocedrus chilensis (D.Don Pic. Ser. et Bizzarri es la conífera nativa de mayor importancia económica de los bosques templados de Argentina. Se han detectado en la bibliografía imprecisiones respecto al rango latitudinal en el que se desarrolla, las que motivaron este estudio. Se determinaron los extremos de ese rango en base a antecedentes bibliográficos, información provista por pobladores y expertos regionales, y reconocimientos en el campo. El extremo septentrional se ubica a los 32º 39' S (Región V de Valparaíso, Chile, y el extremo austral se halla a los 43º 44' S (Provincia de Chubut, Argentina, lo que representa una distancia de unos 1230 km . Esta variación latitudinal y el carácter fragmentario de su distribución natural apoyan la hipótesis de la existencia de ecotipos en la especie.The "Patagonian Cypress" ( Austrocedrus chilensis (D.Don Pic. Ser. et Bizzarri is the most economically important native conifer of the temperate forests of Argentina. Some inaccuracy was detected in the bibliography with respect to its latitudinal range, what motivates the present study. The location of the latitudinal extremes was determined based on bibliographic antecedents, local settlers' and experts' information, and field surveys. The northernmost extreme is located at 32º 39' S (Region V of Valparaíso, Chile, while the southernmost extreme at 43º 44' S (Chubut Province, Argentina. This 11 latitudinal grades range represents a distance of 1230 km. This broad latitudinal range and the fragmentary feature of its natural distribution area support the hypothesis of ecotypes for this species.

  15. Two new species of Nitocrella (Crustacea, Copepoda, Harpacticoida from groundwaters of northwestern Australia expand the geographic range of the genus in a global hotspot of subterranean biodiversity

    Directory of Open Access Journals (Sweden)

    Danny Tang

    2016-11-01

    Full Text Available In Australia, the Ameiridae is the most diverse harpacticoid family in groundwater, with 35 species hitherto reported. In this study, we describe two new species belonging to the “vasconica”-group of the ameirid genus Nitocrella based on specimens collected from groundwaters near mine sites in the Pilbara and Great Sandy Desert regions of northwestern Australia. Nitocrella knotti sp. n. can be distinguished from related taxa by having two setae on the antennal exopod, four armature elements on the distal endopodal segment of leg 2, four armature elements on the distal endopodal segment of leg 3, three armature elements on the distal endopodal segment of leg 4, and three setae on the basoendopodal lobe of leg 5. Nitocrella karanovici sp. n. differs from its congeners by having a short outer spine and long inner seta on the distal endopodal segment of leg 2, three armature elements on the distal endopodal segment of leg 3, and four setae on the basoendopodal lobe of leg 5 in the female. This study is of biogeographic interest in providing the first documentation of the genus Nitocrella from the Pilbara and Great Sandy Desert regions. Both new species of Nitocrella are recorded from restricted localities and appear to be short-range endemics, thus making them potentially vulnerable to environmental changes and threatening processes such as mining. The distribution range of N. karanovici sp. n. coincides with the centre of diversity of the Ethel Gorge aquifer stygobiont community, a globally significant hotspot which is listed as endangered.

  16. Estimating the geographic range of a threatened shark in a data-poor region:Cetorhinus maximus in the South Atlantic Ocean

    Institute of Scientific and Technical Information of China (English)

    Luis O LUCIFORA; Santiago A BARBINI; Edgardo E DI GICOMO; Juan A WAESSLE; Daniel E FIGUEROA

    2015-01-01

    The distribution of the planktivorous basking sharkCetorhinus maximus is influenced by zooplankton abundance at small scales and temperature at medium scales in the North Atlantic. Here, we estimate the distribution of basking sharks on South Atlantic continental shelves, and the relative importance of chlorophyll concentration, as a proxy for zooplankton abun-dance, and temperature in determining habitat suitability for basking sharks at large scales. We used maximum entropy (MaxEnt) and maximum likelihood (MaxLike) species distribution modelling to test three hypotheses: the distribution of basking sharks is determined by (1) temperature, (2) chlorophyll concentration, or (3) both chlorophyll and temperature, while considering other factors, such as oxygen and salinity. Off South America, basking shark habitat included subtropical, temperate and cool-temperate waters between approximately 20°S and 55°S. Off Africa, basking shark habitat was limited to cool-temperate waters off Nami-bia and southern South Africa. MaxLike models had a better fit than MaxEnt models. The best model included minimum chloro-phyll concentration, dissolved oxygen concentration, and sea surface temperature range, supporting hypothesis 3. However, of all variables included in the best model, minimum chlorophyll concentration had the highest influence on basking shark distribution. Unlike the North Atlantic distribution, the South Atlantic distribution of basking sharks includes subtropical and cool-temperate waters. This difference is explained by high minimum chlorophyll concentration off southern Brazil as compared to North Atlan-tic subtropical areas. Observations in other regions of the world support this conclusion. The highest habitat suitability for bask-ing sharks is located close to nearshore areas that experience high anthropogenic impact [Current Zoology 61 (5): 811–826, 2015].

  17. Geographical Tatoos

    Directory of Open Access Journals (Sweden)

    Valéria Cazetta

    2014-08-01

    Full Text Available The article deals with maps tattooed on bodies. My interest in studying the corporeality is inserted in a broader project entitled Geographies and (in Bodies. There is several published research on tattoos, but none in particular about tattooed maps. However some of these works interested me because they present important discussions in contemporary about body modification that helped me locate the body modifications most within the culture than on the nature. At this time, I looked at pictures of geographical tattoos available in several sites of the internet.

  18. Coarse-grained picture of Brownian motion in water: Role of size and interaction distance range on the nature of randomness.

    Science.gov (United States)

    Hanasaki, Itsuo; Nagura, Ryo; Kawano, Satoyuki

    2015-03-14

    The Brownian motion of a particle in a fluid is often described by the linear Langevin equation, in which it is assumed that the mass of the particle is sufficiently large compared to the surrounding fluid molecules. This assumption leads to a diffusion coefficient that is independent of the particle mass. The Stokes-Einstein equation indicates that the diffusion coefficient depends solely on the particle size, but the concept of size can be ambiguous when close to the molecular scale. We first examine the Brownian motion of simple model particles based on short-range interactions in water by the molecular dynamics method and show that the diffusion coefficient can vary with mass when this mass is comparable to that of the solvent molecules, and that this effect is evident when the solute particle size is sufficiently small. We then examine the properties of a water molecule considered as a solute in the bulk solvent consisting of the remainder of the water. A comparison with simple solute models is used to clarify the role of force fields. The long-range Coulomb interaction between water molecules is found to lead to a Gaussian force distribution in spite of a mass ratio and nominal size ratio of unity, such that solutes with short-range interactions exhibit non-Gaussian force distribution. Thus, the range of the interaction distance determines the effective size even if it does not represent the volume excluded by the repulsive force field.

  19. Geographical Mobility, Income, Life Satisfaction and Family Size Preferences: An Empirical Study on Rural Households in Shaanxi and Henan Provinces in China.

    Science.gov (United States)

    Chen, Jiangsheng; Yang, Hong

    Employing data from the China rural-urban mobility survey conducted in 2010, this study investigates the influence of family demographic characteristics on the income, life satisfaction, and potential for rural-urban mobility at the rural household level of two provinces of China: Shaanxi and Henan. A larger labor force in a rural household was found to reduce a family's ability or inclination to move to a city. The findings reveal that family size negatively affects the average income per family member and reduces the marginal income of the labor force and that minor children can improve the life satisfaction of family members. We conclude that a larger family size does not translate to more benefits for a rural household. Family size preference is found to be a reflection of parents' concerns about elderly care and is deemed to be unfavorable for urbanization in P. R. China.

  20. A Long-Term Comparison of Yellowstone Cutthroat Trout Abundance and Size Structure in Their Historical Range in Idaho.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Schill, Daniel J.; Elle, F. Steven

    2002-05-23

    We compared estimates of population abundance and size structure for Yellowstone cutthroat trout Oncorhynchus clarki bouvieri obtained by electrofishing 77 stream segments across southeastern Idaho in the 1980s and again in 1999-2000 to test whether populations of Yellowstone cutthroat trout had changed. Sites sampled in the 1980s were relocated in 1999-2000 by using maps and photographs or by finding original site-boundary stakes, so that the same reach of stream was sampled during both periods. Abundance of Yellowstone cutthroat trout longer than 10 cm did not change, averaging 41 fish/100 m of stream during both the 1980s and 1999-2000. The proportion of the total catch of trout composed of Yellowstone cutthroat trout also did not change, averaging 82% in the 1980s and 78% in 1999-2000. At the 48 sites where size structure could be estimated for both periods, the proportion of Yellowstone cutthroat trout that were 10-20 cm long declined slightly (74% versus 66%), but the change was due entirely to the shift in size structure at the Teton River sites. The number of sites that contained rainbow trout O. mykiss or cutthroat trout 3 rainbow trout hybrids rose from 23 to 37, but the average proportion of the catch composed of rainbow trout and hybrids did not increase (7% in both the 1980s and 1999-2000). Although the distribution and abundance of Yellowstone cutthroat trout have been substantially reduced in Idaho over the last century, our results indicate that Yellowstone cutthroat trout abundance and size structure in Idaho have remained relatively stable at a large number of locations for the last 10-20 years. The expanding distribution of rainbow trout and hybrids in portions of the upper Snake River basin, however, calls for additional monitoring and active management actions.

  1. Measured In Situ Atmospheric Ambient Aerosol Size-Distributions, Particle Concentrations, and Turbulence Data for RSA TA-6 Test Range, Redstone Arsenal, AL, April-May 2015

    Science.gov (United States)

    2015-09-01

    Concentrations, and Turbulence Data for RSA TA-6 Test Range, Redstone Arsenal , AL, April–May 2015 by Kristan Gurton, Stephanie Cunningham, and...Aerosol Size-Distributions, Particle Concentrations, and Turbulence Data for RSA TA-6 Test Range, Redstone Arsenal , AL, April–May 2015 by Kristan...Redstone Arsenal , AL Approved for public release; distribution unlimited. ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188

  2. Evaluation of the size segregation of elemental carbon (EC) emission in Europe: Influence on the simulation of EC long-range transportation

    NARCIS (Netherlands)

    Chen, Y.; Cheng, Y.F.; Nordmann, S.; Birmili, W.; Denier Van Der Gon, H.A.C.; Ma, N.; Wolke, R.; Wehner, B.; Sun, J.; Spindler, G.; Mu, Q.; Pöschl, U.; Su, H.; Wiedensohler, A.

    2016-01-01

    Elemental Carbon (EC) has a significant impact on human health and climate change. In order to evaluate the size segregation of EC emission in the EUCAARI inventory and investigate its influence on the simulation of EC long-range transportation in Europe, we used the fully coupled online Weather

  3. Evaluation of the size segregation of elemental carbon (EC) emission in Europe: Influence on the simulation of EC long-range transportation

    NARCIS (Netherlands)

    Chen, Y.; Cheng, Y.F.; Nordmann, S.; Birmili, W.; Denier Van Der Gon, H.A.C.; Ma, N.; Wolke, R.; Wehner, B.; Sun, J.; Spindler, G.; Mu, Q.; Pöschl, U.; Su, H.; Wiedensohler, A.

    2016-01-01

    Elemental Carbon (EC) has a significant impact on human health and climate change. In order to evaluate the size segregation of EC emission in the EUCAARI inventory and investigate its influence on the simulation of EC long-range transportation in Europe, we used the fully coupled online Weather Res

  4. The effect of kauri (Agathis australis) on grain size distribution and clay mineralogy of andesitic soils in the Waitakere Ranges, New Zealand

    NARCIS (Netherlands)

    Jongkind, A.G.; Buurman, P.

    2006-01-01

    Kauri (Agathis australis) is generally associated with intense podzolisation, but little research has been carried out to substantiate this. We studied soil profiles, grain size distribution patterns and clay mineralogy under kauri and broadleaf/tree fern vegetation in the Waitakere Ranges, North Is

  5. Natural Scales in Geographical Patterns

    Science.gov (United States)

    Menezes, Telmo; Roth, Camille

    2017-04-01

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

  6. Natural Scales in Geographical Patterns

    Science.gov (United States)

    Menezes, Telmo; Roth, Camille

    2017-01-01

    Human mobility is known to be distributed across several orders of magnitude of physical distances, which makes it generally difficult to endogenously find or define typical and meaningful scales. Relevant analyses, from movements to geographical partitions, seem to be relative to some ad-hoc scale, or no scale at all. Relying on geotagged data collected from photo-sharing social media, we apply community detection to movement networks constrained by increasing percentiles of the distance distribution. Using a simple parameter-free discontinuity detection algorithm, we discover clear phase transitions in the community partition space. The detection of these phases constitutes the first objective method of characterising endogenous, natural scales of human movement. Our study covers nine regions, ranging from cities to countries of various sizes and a transnational area. For all regions, the number of natural scales is remarkably low (2 or 3). Further, our results hint at scale-related behaviours rather than scale-related users. The partitions of the natural scales allow us to draw discrete multi-scale geographical boundaries, potentially capable of providing key insights in fields such as epidemiology or cultural contagion where the introduction of spatial boundaries is pivotal. PMID:28374825

  7. Nanoporous anodic aluminum oxide with a long-range order and tunable cell sizes by phosphoric acid anodization on pre-patterned substrates

    Science.gov (United States)

    Surawathanawises, Krissada; Cheng, Xuanhong

    2014-01-01

    Nanoporous anodic aluminum oxide (AAO) has been explored for various applications due to its regular cell arrangement and relatively easy fabrication processes. However, conventional two-step anodization based on self-organization only allows the fabrication of a few discrete cell sizes and formation of small domains of hexagonally packed pores. Recent efforts to pre-pattern aluminum followed with anodization significantly improve the regularity and available pore geometries in AAO, while systematic study of the anodization condition, especially the impact of acid composition on pore formation guided by nanoindentation is still lacking. In this work, we pre-patterned aluminium thin films using ordered monolayers of silica beads and formed porous AAO in a single-step anodization in phosphoric acid. Controllable cell sizes ranging from 280 nm to 760 nm were obtained, matching the diameters of the silica nanobead molds used. This range of cell size is significantly greater than what has been reported for AAO formed in phosphoric acid in the literature. In addition, the relationships between the acid concentration, cell size, pore size, anodization voltage and film growth rate were studied quantitatively. The results are consistent with the theory of oxide formation through an electrochemical reaction. Not only does this study provide useful operational conditions of nanoindentation induced anodization in phosphoric acid, it also generates significant information for fundamental understanding of AAO formation. PMID:24535886

  8. Nanoporous anodic aluminum oxide with a long-range order and tunable cell sizes by phosphoric acid anodization on pre-patterned substrates.

    Science.gov (United States)

    Surawathanawises, Krissada; Cheng, Xuanhong

    2014-01-20

    Nanoporous anodic aluminum oxide (AAO) has been explored for various applications due to its regular cell arrangement and relatively easy fabrication processes. However, conventional two-step anodization based on self-organization only allows the fabrication of a few discrete cell sizes and formation of small domains of hexagonally packed pores. Recent efforts to pre-pattern aluminum followed with anodization significantly improve the regularity and available pore geometries in AAO, while systematic study of the anodization condition, especially the impact of acid composition on pore formation guided by nanoindentation is still lacking. In this work, we pre-patterned aluminium thin films using ordered monolayers of silica beads and formed porous AAO in a single-step anodization in phosphoric acid. Controllable cell sizes ranging from 280 nm to 760 nm were obtained, matching the diameters of the silica nanobead molds used. This range of cell size is significantly greater than what has been reported for AAO formed in phosphoric acid in the literature. In addition, the relationships between the acid concentration, cell size, pore size, anodization voltage and film growth rate were studied quantitatively. The results are consistent with the theory of oxide formation through an electrochemical reaction. Not only does this study provide useful operational conditions of nanoindentation induced anodization in phosphoric acid, it also generates significant information for fundamental understanding of AAO formation.

  9. On the pressure difference ranges which assure a specified gap size for semiconductor crystals grown in terrestrial dewetted Bridgman

    Science.gov (United States)

    Braescu, L.

    2010-04-01

    The complexity of the dewetting phenomenon on the ground consists mainly in the presence of the hydrostatic pressure which should be counterbalanced by a supplementary gas pressure difference ΔP=Pc-Ph between the cold and hot sides of the sample. The experiments have shown that using uncoated and coated crucibles, detached and partially detached growth can be obtained; dewetting became unsuccessful when the liquid-solid interface changed its shape—phenomenon which proved connection between the meniscus shape, pressure difference and stable dewetting. Because the interest is to grow crystals with specified gap size, the ΔP limits and the corresponding menisci shapes for which dewetting is feasible are first established, on the base of the theoretical and computational investigations. Then, for the obtained menisci, the static stability via the conjugate point criterion of the calculus of variations is studied in the cases of the classical semiconductors grown in (i) uncoated crucibles (i.e., the wetting angle θc and growth angle αe satisfy the inequality θc+αeii) coated crucibles or pollution ( θc+αe≥180∘). In this way, gap thickness limitations for which the menisci are physically realizable are obtained. Numerical results are performed for InSb crystal grown in uncoated ampoule, and for Ge crystal grown in coated ampoule.

  10. Response of the Nevzorov hot wire probe in clouds dominated by droplet conditions in the drizzle size range

    Directory of Open Access Journals (Sweden)

    A. Schwarzenboeck

    2009-12-01

    Full Text Available During the airborne research mission ASTAR 2004 (Arctic Study of Tropospheric Aerosols, Clouds and Radiation performed over the island of Svalbard in the Arctic a constant-temperature hot-wire Nevzorov Probe designed for aircraft measurements, has been used onboard the aircraft POLAR 2. The Nevzorov probe measured liquid water (LWC and total condensed water content (TWC in supercooled liquid and partly mixed phase clouds, respectively. As for other hotwire probes the calculation of LWC and/or TWC (and thus the ice water content IWC has to take into account the collection efficiencies of the two separate sensors for LWC and TWC which both react differently with respect to cloud phase and what is even more difficult to quantify with respect to the size of ice and liquid cloud particles. The study demonstrates that during pure liquid cloud sequences the ASTAR data set of the Nevzorov probe allowed to improve the quantification of the collection efficiency, particularly of the LWC probe part with respect to water. The improved quantification of liquid water content should lead to improved retrievals of IWC content. Simultaneous retrievals of LWC and IWC are correlated with the asymmetry factor derived from the Polar Nephelometer instrument.

  11. Movement Patterns, Home Range Size and Habitat Selection of an Endangered Resource Tracking Species, the Black-Throated Finch (Poephila cincta cincta).

    Science.gov (United States)

    Rechetelo, Juliana; Grice, Anthony; Reside, April Elizabeth; Hardesty, Britta Denise; Moloney, James

    2016-01-01

    Understanding movement patterns and home range of species is paramount in ecology; it is particularly important for threatened taxa as it can provide valuable information for conservation management. To address this knowledge gap for a range-restricted endangered bird, we estimated home range size, daily movement patterns and habitat use of a granivorous subspecies in northeast Australia, the black-throated finch (Poephila cincta cincta; BTF) using radio-tracking and re-sighting of colour banded birds. Little is known about basic aspects of its ecology including movement patterns and home range sizes. From 2011-2014 we colour-banded 102 BTF and radio-tracked 15 birds. We generated home ranges (calculated using kernel and Minimum Convex Polygons techniques of the 15 tracked BTF). More than 50% of the re-sightings occurred within 200 m of the banding site (n = 51 out of 93 events) and within 100 days of capture. Mean home-range estimates with kernel (50%, 95% probability) and Minimum Convex Polygons were 10.59 ha, 50.79 ha and 46.27 ha, respectively. Home range size differed between two capture sites but no seasonal differences were observed. BTF home ranges overlapped four habitat types among eight available. Habitat selection was different from random at Site 1 (χ2 = 373.41, df = 42, p<0.001) and Site 2 (χ2 = 1896.1, df = 45, p<0.001); however, the preferred habitats differed between the two sites. BTF moved further than expected on the basis of current knowledge, with three individuals being resighted over 15 km from the banding location. However, BTF maintain small home ranges over short time-frames. Occasional long-distance movements may be related to resource bottleneck periods. Daily movement patterns differed between sites, which is likely linked to the fact that the sites differ in the spatial distribution of resources. The work provides information about home range sizes and local movement of BTF that will be valuable for targeting effective management

  12. Geographic Information Systems.

    Science.gov (United States)

    Wieczorek, William F; Delmerico, Alan M

    2009-01-01

    spatial data and related phenomena. The capabilities of GIS are much more than just mapping, although map production is one of the most utilized features. GIS applications are relevant in a tremendous number of areas ranging from basic geographic inventories to simulation models.This chapter presents a general overview of geographic information system topics. The purpose is to provide the reader with a basic understanding of a GIS, the types of data that are needed, the basic functionality of these systems, the role of spatial analysis, and an example in the form of a case study. The chapter is designed to provide advanced students and experts outside of the field of GIS sufficient information to begin to utilize GIS and spatial analytic concepts, but it is not designed to be the sole basis for becoming a GIS expert. There is a tremendous level of sophistication related to the digital cartographic databases and manipulation of those databases underlying the display and use of GIS that is more appropriately a part of geographic information science (i.e., basic research issues associated with geographic data including technical as well as theoretical aspects such as the impact on society [1]) rather than being relevant to this chapter. The utilization of GIS for conducting spatial analysis is the guiding theme for the chapter.

  13. Climate change velocity since the Last Glacial Maximum and its importance for patterns of species richness and range size

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Arge, Lars Allan; Svenning, J.-C.

    Contemporary patterns of species distributions are influenced by both current and historical conditions. Historically unstable climates can lead to reductions in species richness, when species go extinct because they cannot track climate changes, when dispersal limitation causes species to fail...... to fully occupy suitable habitat, or when local diversification rates are depressed by local population extinctions and changing selective regimes. Locations with long-term climate instability should therefore show reduced species richness with small-ranged species particularly missing from the community...... is likely to be a more biologically meaningful measure of climate stability than the previously used simple climate anomaly, because it scales climate change relative to local variation in climate, capturing the potential for topographic refuges to buffer species from climate change. We tested...

  14. Climate change velocity since the Last Glacial Maximum and its importance for patterns of species richness and range size

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Arge, Lars Allan; Svenning, J.-C.

    Contemporary patterns of species distributions are influenced by both current and historical conditions. Historically unstable climates can lead to reductions in species richness, when species go extinct because they cannot track climate changes, when dispersal limitation causes species to fail...... to fully occupy suitable habitat, or when local diversification rates are depressed by local population extinctions and changing selective regimes. Locations with long-term climate instability should therefore show reduced species richness with small-ranged species particularly missing from the community....... We used a novel measure of climate stability, climate change velocity, which combines information on temporal and spatial gradients in climate to describe the rate at which a particular climate condition is moving over the surface of the Earth. Climate change velocity since the Last Glacial Maximum...

  15. Validity of Dynamic Light Scattering Method to Analyze a Range of Gold and Copper Nanoparticle Sizes Attained by Solids Laser Ablation in Liquid

    Directory of Open Access Journals (Sweden)

    Yu. V. Golubenko

    2014-01-01

    Full Text Available Nanoparticles of metals possess a whole series of features, concerned with it’s sizes, this leads to appearing or unusual electromagnetic and optical properties, which are untypical for particulates.An extended method of receiving nanoparticles by means of laser radiation is pulse laser ablation of hard targets in liquid medium.Varying the parameters of laser radiation, such as wavelength of laser radiation, energy density, etc., we can operate the size and shape of the resultant particles.The greatest trend of application in medicine have the nanoparticles of iron, copper, silver, silicon, magnesium, gold and zinc.The subject matter in this work is nanoparticles of copper and gold, received by means of laser ablation of hard targets in liquid medium.The aim of exploration, represented in the article, is the estimation of application of the dynamic light scattering method for determination of the range of nanoparticles sizes in the colloidal solution.For studying of the laser ablation process was chosen the second harmonic of Nd:YAG laser with the wavelength of 532 nm. Special attention was spared for the description of the experiment technique of receiving of nanoparticles.As the liquid medium ethanol and distillation water were used.For exploration of the received colloidal system have been used the next methods: DLS, transmission electron microscopy (TEM and scanning electron microscopy (SEM.The results of measuring by DLS method showed that colloidal solution of the copper in the ethanol is the steady system. Copper nanoparticle’s size reaches 200 nm and is staying in the same size for some time.Received system from the gold’s nanoparticles is polydisperse, unsteady and has a big range of the nanoparticle’s sizes. This fact was confirmed by means of photos, got from the TEM FEI Tecnai G2F20 + GIF and SEM Helios NanoLab 660. The range of the gold nanoparticle’s sizes is from 5 to 60 nm. So, it has been proved that the DLS method is

  16. On dependence of mechanical properties of brittle material on partial concentrations of different sized pores in its structure in a wide range of porosity

    Science.gov (United States)

    Konovalenko, Igor S.; Smolin, Alexey Yu.; Psakhie, Sergey G.

    2015-10-01

    2D and 3D models of mechanical behavior of brittle porous material under uniaxial compression loading were developed in the framework of the movable cellular automaton method. The considered material was characterized by pore size distribution function having two maxima. On the basis of simulation results the dependence of the strength properties of brittle porous material on its total porosity and partial porosities corresponding to pores with different size was revealed. The change in internal structure of material in a wide range of mentioned parameters was analyzed. The main structural factors influencing compression strength of the material at various combinations of values of porosity parameters were identified.

  17. The turbulent structures around clusters formed under a range of armoring shear stresses and grain size distributions

    Science.gov (United States)

    Curran, J. C.; Tan, L.

    2011-12-01

    In gravel bed rivers, low flows generate shear stresses less than what is needed to entrain the largest particles but large enough to transport the fines. During sustained low flows, fine sediment winnows from the bed surface and an armored surface layer forms. As the surface armor forms, a surface structure develops that increases bed roughness and flow resistance and can be characterized by the presence of clusters. Individual clusters are known to exert a significant influence over the spatial and temporal flow processes acting in the vicinity of the bed. A series of flume experiments investigated the turbulent structures formed around clusters naturally developed during bed armoring. The series of experiments created armored beds using four different flow rates and four different bulk grain size distributions which progressively increased in the percent sand in the bed sediment. Following an initial run segment that established equilibrium sediment transport and full bed mobility, the flow rate in the flume was reduced and the bed surface fully armored. Once armored, clusters were identified using a combination of bed DEM, vertical profile, and visual analysis. Instantaneous three-dimensional flow velocities were measured around the clusters using an Acoustic Doppler Velocimeter, and these values were used to calculate Reynolds shear stresses, turbulence intensities, and turbulent kinetic energy in the flow field. Results show a significant change in the flow profiles over a cluster when compared to an open area of the armored bed. Reynolds shear stresses doubled over the cluster and turbulence intensity reached a peak value right above the single cluster. The results also suggest the effects of the single cluster on the surrounding flow dynamics are quite localized and limited to 30cm in lateral orientation. Quadrant analysis showing large ejection and sweep events around clusters indicates vortex formation at the cluster crest. The magnitude of the coherent

  18. A specimen of Paralycoptera Chang & Chou 1977 (Teleostei: Osteoglossoidei) from Hong Kong (China) with a potential Late Jurassic age that extends the temporal and geographical range of the genus.

    Science.gov (United States)

    Tse, Tze-Kei; Pittman, Michael; Chang, Mee-Mann

    2015-01-01

    We describe a Mesozoic fish Paralycoptera sp. (Teleostei: Osteoglossoidei), on the basis of a postcranial skeleton collected from the volcaniclastic mudstones of the Lai Chi Chong Formation of Hong Kong, China. The new finding-representing the city's first Mesozoic fish-extends the geographical distribution of Paralycoptera from eastern mainland China into Hong Kong, demonstrating a wider distribution than previously appreciated for this genus. A radiometric age for the Lai Chi Chong Formation of 146.6 ± 0.2 Ma implies a temporal range expansion for Paralycoptera of approximately 40 million years back from the Early Cretaceous (∼110 Ma). However, spores found in the Formation suggest an Early Cretaceous age that is consistent with the existing age assignment to Paralycoptera. We argue that the proposed temporal range extension is genuine because it is based on recent high precision radiometric age data, but given the discrepancies with the biostratigraphic ages further investigation is needed to confirm this. This study provides an important step towards revealing Hong Kong's Mesozoic vertebrate fauna and understanding its relationship to well-studied mainland Chinese ones.

  19. Geographic variation in Caluromys derbianus and Caluromys lanatus (Didelphimorphia: Didelphidae

    Directory of Open Access Journals (Sweden)

    Raul Fonseca

    2015-04-01

    Full Text Available We analyzed the geographic variations in the shape and size of the cranium and mandible of two woolly opossums, Caluromys derbianus and Caluromys lanatus. Using geometric morphometrics we analyzed 202 specimens of C. derbianus and 123 specimens of C. lanatus, grouped in 7 and 9 populations, respectively. We found sexual dimorphism in shape variables only in the dorsal view of the cranium of Caluromys derbianus, which is not associated with geographical origin. We detected geographic variation in the size of the mandible in two populations (Nicaragua and Northern Panama, but no geographic variation in shape. The size of the cranium of C. lanatus varies significantly, with clinal variation in peri-Amazon populations, with a break between two populations, Bolivia and Paraguay. Shape analyses also revealed some separation between the Paraná population and all other populations. Our results suggest that the available name, Caluromys derbianus, should be maintained for all individuals throughout the geographic range of the species. The same is true for Caluromys lanatus, which can be separated into two distinct morphologic units, Caluromys lanatus ochropus, from the Amazon and Cerrado, and Caluromys lanatus lanatus, from the Atlantic forest.

  20. The measure of success: geographic isolation promotes diversification in Pachydactylus geckos.

    Science.gov (United States)

    Heinicke, Matthew P; Jackman, Todd R; Bauer, Aaron M

    2017-01-11

    Geckos of the genus Pachydactylus and their close relatives comprise the most species-rich clade of lizards in sub-Saharan Africa. Many explanations have been offered to explain species richness patterns of clades. In the Pachydactylus group, one possible explanation is a history of diversification via geographic isolation. If geographic isolation has played a key role in facilitating diversification, then we expect species in more species-rich subclades to have smaller ranges than species in less diverse subclades. We also expect traits promoting geographic isolation to be correlated with small geographic ranges. In order to test these expectations, we performed phylogenetic analyses and tested for correlations among body size, habitat choice, range sizes, and diversification rates in the Pachydactylus group. Both body size and habitat use are inferred to have shifted multiple times across the phylogeny of the Pachydactylus group, with large size and generalist habitat use being ancestral for the group. Geographic range size is correlated with both of these traits. Small-bodied species have more restricted ranges than large-bodied species, and rock-dwelling species have more restricted ranges than either terrestrial or generalist species. Rock-dwelling and small body size are also associated with higher rates of diversification, and subclades retaining ancestral conditions for these traits are less species rich than subclades in which shifts to small body size and rocky habitat use have occurred. The phylogeny also illustrates inadequacies of the current taxonomy of the group. The results are consistent with a model in which lineages more likely to become geographically isolated diversify to a greater extent, although some patterns also resemble those expected of an adaptive radiation in which ecological divergence acts as a driver of speciation. Therefore, the Pachydactylus group may represent an intermediate between clades in which radiation is adaptive versus

  1. The size of the community rather than its geographical location better defines the risk of iodine deficiency: results of an extensive survey in Southern Italy.

    Science.gov (United States)

    Aghini-Lombardi, F; Vitti, P; Antonangeli, L; Fiore, E; Piaggi, P; Pallara, A; Consiglio, E; Pinchera, A

    2013-05-01

    The objective of this study was to establish the status of iodine nutrition in Southern Italy. The survey was carried out on 11-14 yr old children attending primary school and living in urban and non urban areas of 8 regions of Southern Italy. Urinary iodine excretion (UIE) was measured in 23,103 urinary samples randomly collected. Median UIE in the whole studied population was 74 μg/l [interquartile range (IR) 34-139 μg/l]. UIE was significantly higher in chief towns compared to non chief towns (81 μg/l, IR 39-145 μg/l vs 73 μg/l, IR 33-138 μg/l, p500 inhabitants per km² (median 87 μg/l, IR 43-154 μg/l) compared to areas with 100-500 per km² (median 66 μg/l, IR 29-126 μg/l, pdiversification of dietary habits and the easier availability of iodized salt and processed food through commercial facilities, more common in larger communities. Future monitoring surveys should take into account these observations.

  2. Dietary change of the rock lobster Jasus lalandii after an ‘invasive’ geographic shift: Effects of size, density and food availability

    Science.gov (United States)

    Haley, C. N.; Blamey, L. K.; Atkinson, L. J.; Branch, G. M.

    2011-06-01

    During the 1990s the rock lobster Jasus lalandii shifted its focus of distribution south-eastwards along the coast of South Africa, to establish a dense population in an area where it was previously rare. This coincided with a marked decrease in the sea urchin Parechinus angulosus, a preferred prey item of J. lalandii and a vital source of shelter for juveniles of the abalone Haliotis midae. The range expansion of lobsters has thus economic and ecological ripple effects. We determined the diets of small (50-65 mm carapace length) and large (>69 mm CL) rock lobsters from gut content analyses, and compared them between three 'lobster invaded' sites and three adjacent 'non-invaded' sites where densities are still low. At the non-invaded sites, diets were collectively heterogeneous but the dietary breadth of individual lobsters was narrow (in contradiction to generally accepted ecological theory), and the lobsters fed mainly on large, individual, mobile, high-energy prey such as sea urchins and large winkles. Conversely, at invaded sites where lobster densities were high, they consumed predominantly small, colonial or sessile low-energy prey such as sponges, barnacles and foliar algae, and the diet was significantly more uniform among individuals, but broader within individuals. This was a direct result of the contrasting benthic community structure of the two areas, and consequent prey availability - itself caused by differences in intensity of rock-lobster predation. Cannibalism was unexpectedly greater at non-invaded sites, possibly as a result of lobsters being larger there. The diet of small and large lobsters also differed significantly. Large rock lobsters predominantly consumed large individual prey such as lobsters, urchins and crabs, while small rock lobsters ate mainly colonial, sessile prey such as sponges and barnacles, and small prey such as tiny winkles and crustaceans. Dietary selectivity indices revealed that algae and sponges were negatively selected

  3. A Multi-Faceted Approach to Analyse the Effects of Environmental Variables on Geographic Range and Genetic Structure of a Perennial Psammophilous Geophyte: The Case of the Sea Daffodil Pancratium maritimum L. in the Mediterranean Basin.

    Science.gov (United States)

    De Castro, Olga; Di Maio, Antonietta; Di Febbraro, Mirko; Imparato, Gennaro; Innangi, Michele; Véla, Errol; Menale, Bruno

    2016-01-01

    The Mediterranean coastline is a dynamic and complex system which owes its complexity to its past and present vicissitudes, e.g. complex tectonic history, climatic fluctuations, and prolonged coexistence with human activities. A plant species that is widespread in this habitat is the sea daffodil, Pancratium maritimum (Amaryllidaceae), which is a perennial clonal geophyte of the coastal sands of the Mediterranean and neighbouring areas, well adapted to the stressful conditions of sand dune environments. In this study, an integrated approach was used, combining genetic and environmental data with a niche modelling approach, aimed to investigate: (1) the effect of climate change on the geographic range of this species at different times {past (last inter-glacial, LIG; and last glacial maximum, LGM), present (CURR), near-future (FUT)} and (2) the possible influence of environmental variables on the genetic structure of this species in the current period. The genetic results show that 48 sea daffodil populations (867 specimens) display a good genetic diversity in which the marginal populations (i.e. Atlantic Sea populations) present lower values. Recent genetic signature of bottleneck was detected in few populations (8%). The molecular variation was higher within the populations (77%) and two genetic pools were well represented. Comparing the different climatic simulations in time, the global range of this plant increased, and a further extension is foreseen in the near future thanks to projections on the climate of areas currently-more temperate, where our model suggested a forecast for a climate more similar to the Mediterranean coast. A significant positive correlation was observed between the genetic distance and Precipitation of Coldest Quarter variable in current periods. Our analyses support the hypothesis that geomorphology of the Mediterranean coasts, sea currents, and climate have played significant roles in shaping the current genetic structure of the sea

  4. The effects of leaf area density variation on the collection efficiency of black carbon in the size range of ultrafine particles (UFP)

    Science.gov (United States)

    Huang, C.; Lin, M.; Khlystov, A.; Katul, G. G.

    2012-12-01

    Black carbon is mainly produced in the ultra-fine particle (UFP) size range of 10-100 nm from combustion processes and is now receiving significant attention given its role in global and regional climate change, cloud physics, human health and respiratory related diseases. Likewise, the role of vegetated surfaces in removing UFP is drawing increased attention, prompting interest in the relationship between leaf area density and UFP collection efficiency. Here, carbonaceous particles, mainly black carbon, were generated by burning candles during "sooting burn" to explore the effects of leaf area density (LAD) variation on the collection efficiency of black carbon in the UFP size range. Three scenarios were explored in a wind tunnel: (1) Juniperus Chinensis branches that are uniformly distributed within the test section; (2) LAD that is linearly increasing with downwind distance and (3) LAD that is decreasing with downwind distance. The total leaf area index (LAI) was maintained constant in all three cases. Particle concentrations were measured at multiple locations within the vegetated volume for a range of sizes of UFP (12.6-102 nm) using Scanning Mobility Particle Sizer (SMPS). The measured concentration can be used to evaluate the performance of a size-resolving model that couples the turbulent flow field and the collection efficiency for the variable LAD. The model assumes that (i) the mean longitudinal momentum balance is controlled only by the interplay between drag force and the pressure gradient, and (ii) the dominant collection mechanism for UFP is Brownian diffusion. Hence, other collection mechanisms such as inertial impaction, interception and phoretic effects are negligible. Good agreement was found between the model calculations of the UFP collection efficiency by the vegetation and the wind tunnel measurements for all three cases and across a wide range of wind speeds and particle size. It was shown that variations in leaf area density lead to a

  5. The short-term outcome of the modified Sauvé-Kapandji procedure regarding range of motion, carpal bone translation and bony shelf size.

    Science.gov (United States)

    Toyama, Shogo; Tamai, Kazuo; Sakamoto, Atsuto; Hirashima, Toshiko

    2011-02-01

    The Sauvé-Kapandji (S-K) procedure is a common treatment for rheumatoid wrists, but in some cases severe bone destruction makes this operative modality difficult to perform, while also resulting in a poor outcome. A modified S-K procedure for these wrists has been reported, but the clinical outcomes of the modified procedure are unclear. This study evaluated 24 wrists in 20 patients who underwent the modified S-K procedure. The mean follow-up period was 34.5 months. The clinical assessments were range of motion, carpal bone translation and bony shelf size. The range of motion and carpal bone translation were similar to those produced by the S-K procedure. In regard to bony shelf size, wrists with an excessively large bony shelf tended to have a progression of carpal bone translation toward the palmar direction due to the residual malposition of the ECU tendon. The modified S-K procedure appears to be a safe and effective surgical alternative for the treatment of severely destroyed rheumatoid wrists. Although the modified procedure allows for the adjustment of the bony shelf size, it should not be used with wrists that have an excessively large bony shelf.

  6. Size effect of strong-coupled superconducting In{sub 2}Bi nanoparticles: An investigation of short-range electron phonon coupling

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Po-Yu; Gandhi, Ashish Chhaganlal; Wu, Sheng Yun, E-mail: sywu@mail.ndhu.edu.tw [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China)

    2015-05-07

    We report the influence of the nanosized effect on the superconducting properties of bimetallic In{sub 2}Bi nanoparticles. In this study, the temperature- and applied magnetic field-dependence of the magnetization were utilized to investigate the electron-phonon coupling effect while controlling particle sizes 〈d〉 from 21(2) to 42(5) nm. As the particle size decreases, the electron-phonon constant λ{sub EP} decreases rapidly, signaling the short-range electron-phonon coupling effect which acts to confine the electrons within a smaller volume, thereby giving rise to a higher superconducting transition temperature T{sub C}. An enhanced superconducting transition was observed from the temperature dependence of magnetization, revealing a main diamagnetic Meissner state below T{sub C} ∼ 5.72(5) K for 〈d〉 = 31(1) nm In{sub 2}Bi nanoparticles. The variation of the T{sub C} is very sensitive to the particle size, which might be due to crystallinity and size uniformity of the samples. The electron-phonon coupling to low lying phonons is found to be the leading mechanism for the observed strong-coupling superconductivity in the In{sub 2}Bi system.

  7. A laboratory study of the performance of the handheld diffusion size classifier (DiSCmini) for various aerosols in the 15-400 nm range.

    Science.gov (United States)

    Bau, S; Zimmermann, B; Payet, R; Witschger, O

    2015-02-01

    In addition to chemical composition, particle concentration and size are among the main parameters used to characterize exposure to airborne ultrafine or nanoparticles. To assess occupational inhalation exposure, real-time instruments are recommended in recent strategies published. Among portable devices for personal exposure assessment in the workplace, DiSCmini (Matter Aerosol AG, Switzerland) has been identified as a potential candidate with its capacity to measure the airborne nanoparticle concentration and average particle size with good time-resolution. Monodisperse and polydisperse test nanoaerosols of varying compositions and morphologies were produced in the laboratory using the CAIMAN facility. These aerosols covered a range of particle sizes between 15 and 400 nm and number concentrations from 700 to 840,000 cm(-3). The aerosols were used to investigate the behavior of DiSCmini, comparing experimental data to reference data. In spite of a slight tendency to underestimate particle size, all particle diameters, number concentrations and surface area concentrations measured were in the same order of magnitude as reference data. Furthermore, no significant effect due to particle composition or morphology was noted.

  8. Experimental determination of the steady-state charging probabilities and particle size conservation in non-radioactive and radioactive bipolar aerosol chargers in the size range of 5–40 nm

    Energy Technology Data Exchange (ETDEWEB)

    Kallinger, Peter, E-mail: peter.kallinger@univie.ac.at; Szymanski, Wladyslaw W. [University of Vienna, Faculty of Physics (Austria)

    2015-04-15

    Three bipolar aerosol chargers, an AC-corona (Electrical Ionizer 1090, MSP Corp.), a soft X-ray (Advanced Aerosol Neutralizer 3087, TSI Inc.), and an α-radiation-based {sup 241}Am charger (tapcon & analysesysteme), were investigated on their charging performance of airborne nanoparticles. The charging probabilities for negatively and positively charged particles and the particle size conservation were measured in the diameter range of 5–40 nm using sucrose nanoparticles. Chargers were operated under various flow conditions in the range of 0.6–5.0 liters per minute. For particular experimental conditions, some deviations from the chosen theoretical model were found for all chargers. For very small particle sizes, the AC-corona charger showed particle losses at low flow rates and did not reach steady-state charge equilibrium at high flow rates. However, for all chargers, operating conditions were identified where the bipolar charge equilibrium was achieved. Practically, excellent particle size conservation was found for all three chargers.

  9. Size-dependent modulation of graphene oxide-aptamer interactions for an amplified fluorescence-based detection of aflatoxin B1 with a tunable dynamic range.

    Science.gov (United States)

    Zhang, JingJing; Li, Zengmei; Zhao, Shancang; Lu, Yi

    2016-06-20

    Aflatoxin B1 (AFB1) is a common toxin found in many foods. While AFB1 sensors have been reported, few studies have shown amplified detection with tunable dynamic ranges. We herein report a simple and highly sensitive amplified aptamer-based fluorescent sensor for AFB1, which relies on the ability of nano-graphene oxide (GO) to protect aptamers from nuclease cleavage for amplified detection and on the nanometer size effect of GO to tune the dynamic range and sensitivity. The assay was performed by simply mixing the carboxyl-X-rhodamine (ROX)-labeled AFB1 aptamer, the GO, the nuclease, and the AFB1 samples. Modulating the size of the GO nanosheet resulted in three dynamic ranges, i.e., 12.5 to 312.5 ng mL(-1), 1.0 to 100 ng mL(-1), and 5.0 to 50 ng mL(-1), with corresponding limits of detection of 10.0 ng mL(-1), 0.35 ng mL(-1) and 15.0 ng mL(-1), respectively. The sensor was highly selective against other aflatoxins and common molecules in foods, and its performance was verified in corn samples spiked with known concentration of AFB1.

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

    Science.gov (United States)

    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.

  11. Hydration free energy of hard-sphere solute over a wide range of size studied by various types of solution theories

    Directory of Open Access Journals (Sweden)

    N.Matubayasi

    2007-12-01

    Full Text Available The hydration free energy of hard-sphere solute is evaluated over a wide range of size using the method of energy representation, information-theoretic approach, reference interaction site model, and scaled-particle theory. The former three are distribution function theories and the hydration free energy is formulated to reflect the solution structure through distribution functions. The presence of the volume-dependent term is pointed out for the distribution function theories, and the asymptotic behavior in the limit of large solute size is identified. It is indicated that the volume-dependent term is a key to the improvement of distribution function theories toward the application to large molecules.

  12. Three-dimensional carbon foam supported tin oxide nanocrystallites with tunable size range: Sulfonate anchoring synthesis and high rate lithium storage properties

    Science.gov (United States)

    Ma, Yue; Asfaw, Habtom Desta; Edström, Kristina

    2015-10-01

    The development of a free-standing electrode with high rate capability requires the realization of facile electrolyte percolation, fast charge transfer at the electrode-electrolyte interface as well as the intimate electrical wiring to the current collector. Employing a sulfonated high internal phase emulsion polymer (polyHIPE) as the carbon precursor, we developed a free-standing composite of carbon foam encapsulated SnO2 nanocrystallites, which simultaneously satisfies the aforementioned requirements. When directly evaluated in the pouch cell without using the binder, carbon additive or metallic current collector, the best performing composite exhibits a good rate performance up to 8 A g-1 and very stable cyclability for 250 cycles. This cycling performance was attributed to the synergistic coupling of hierarchical macro/mesoporous carbon foam and SnO2 nanocrystals with optimized size range. Postmortem characterizations unveiled the significant influence of subtle size variation of oxides on the electrochemical performance.

  13. Decrease in the CGG{sub n} trinucleotide repeat mutation of the fragile X syndrome to normal size range during paternal transmission

    Energy Technology Data Exchange (ETDEWEB)

    Vaeisaenen, M.L.; Haataja, R.; Leisti, J. [Oulu Univ. Hospital (Finland)

    1996-09-01

    The fragile X syndrome, the most common inherited form of mental retardation, is caused by the expansion of a CGG{sub n} trinucleotide repeat in the FMR-1 gene. Although the repeat number usually increases during transmission, few cases with reduction of an expanded CGG{sub n} repeat back to the normal size range have been reported. We describe for the first time a family in which such reduction has occurred in the paternal transmission. The paternal premutation ({Delta} = 300 hp) was not detected in one of the five daughters or in the son of this daughter, although he had the grandpaternal RFLP haplotype. Instead, fragments indicating the normal CGG{sub n} repeat size were seen on a Southern blot probed with StB12.3. PCR analysis of the CGG{sub n} repeat confirmed this; in addition to a maternal allele of 30 repeats, an allele of 34 repeats was detected in the daughter and, further, in her son. Sequencing of this new allele revealed a pure CGG{sub n} repeat configuration without AGG interruptions. No evidence for a somatic mosaicism of a premutation allele in the daughter or a normal allele in her father was detected when investigating DNA derived from blood lymphocytes and skin fibroblasts. Another unusual finding in this family was lack of the PCR product of the microsatellite marker RS46 (DXS548) in one of the grandmaternal X chromosomes, detected as incompatible inheritance of RS46 alleles. The results suggest an intergenerational reduction in the CGG{sub n} repeat from premutation size to the normal size range and stable transmission of the contracted repeat to the next generation. However, paternal germ-line mosaicism could not be excluded as an alternative explanation for the reverse mutation. 37 refs., 4 figs.

  14. The political economy of geographical indications

    OpenAIRE

    Deconinck, Koen; Swinnen, Johan

    2014-01-01

    Despite the growing importance of geographical indications (GI), relatively little attention has been devoted to studying the optimal size of a GI region, as well as how lobbying by interest groups may affect the actual size. We develop a political economy model of the size of geographical indications, taking into account possible effects on perceived quality as well as on cost sharing among producers. We show that the political process may result in a GI area that is smaller or larger than t...

  15. Realization of wide size range 1D ZnO micro/nano rods for versatile micro/nano devices by controlled seed layer thickness

    Science.gov (United States)

    Sun, Jingchang; Bian, Jiming; Chen, Liansong; Wang, Yuxin; Gong, Yu; Li, Yang; Liu, Kuichao; Chang, Cheng; Li, Ming; Du, Guotong

    2013-07-01

    We report on the effect of seed layers thickness on the synthesis of one dimensional (1D) ZnO rods using chemical bath deposition method. This procedure allows us to control the length and diameter of 1D ZnO rods in a large size range by modifying the ZnO seed layer thickness. With the increase in thickness of the seed layer, the length of the 1D ZnO rods ranges from 13.1 μm to 2.1 μm, and the diameter varies from 2.4 μm to 102 nm, meanwhile the laying 1D ZnO rods standup gradually. Photoluminescence measurements indicate that the near band edge emission of the 1D ZnO rods blueshift to higher energy direction with the increasing seed layers thickness.

  16. Dingoes at the Doorstep: Home Range Sizes and Activity Patterns of Dingoes and Other Wild Dogs around Urban Areas of North-Eastern Australia.

    Science.gov (United States)

    McNeill, Alice T; Leung, Luke K-P; Goullet, Mark S; Gentle, Matthew N; Allen, Benjamin L

    2016-08-16

    Top-predators around the world are becoming increasingly intertwined with humans, sometimes causing conflict and increasing safety risks in urban areas. In Australia, dingoes and dingo×domesticdoghybridsarecommoninmanyurbanareas,andposeavarietyofhumanhealth and safety risks. However, data on urban dingo ecology is scant. We GPS-collared 37 dingoes in north-easternAustraliaandcontinuouslymonitoredthemeach30minfor11-394days. Mostdingoes were nocturnal, with an overall mean home range size of 17.47 km2. Overall mean daily distance travelled was 6.86 km/day. At all times dingoes were within 1000 m of houses and buildings. Home ranges appeared to be constrained to patches of suitable vegetation fragments within and around human habitation. These data can be used to reallocate dingo management effort towards mitigating actual conflicts between humans and dingoes in urban areas.

  17. Chemical composition and aerosol size distribution of the middle mountain range in the Nepal Himalayas during the 2009 pre-monsoon season

    Directory of Open Access Journals (Sweden)

    P. Shrestha

    2010-06-01

    Full Text Available Aerosol particle number size distribution and chemical composition were measured at two low altitude sites, one urban and one relatively pristine valley, in Central Nepal during the 2009 pre-monsoon season (May–June. This is the first time that aerosol size distribution and chemical composition were measured simultaneously at lower elevation in the Middle Himalayan region in Nepal. The aerosol size distribution was measured using a Scanning Mobility Particle Sizer (SMPS, 14~340 nm, and the chemical composition of the filter samples collected during the field campaign was analyzed in the laboratory. Teflon membrane filters were used for ion chromatography (IC and water-soluble organic carbon and nitrogen analysis. Quartz fiber filters were used for organic carbon and elemental carbon analysis. Multi-lognormal fits to the measured aerosol size distribution indicated a consistent larger mode around 100 nm which is usually the oldest, most processed background aerosol. The smaller mode was located around 20 nm, which is indicative of fresh but not necessarily local aerosol. The diurnal cycle of the aerosol number concentration showed the presence of two peaks (early morning and evening, during the transitional period of boundary layer growth and collapse. The increase in number concentration during the peak period was observed for the entire size distribution. Although the possible contribution of local emissions in size ranges similar to the larger mode cannot be completely ruled out, another plausible explanation is the mixing of aged elevated aerosol in the residual layer during the morning period as suggested by previous studies. Similarly, the evening time concentration peaks when the boundary layer becomes shallow concurrent with increase in local activity. A decrease in aerosol number concentration was observed during the nighttime with the development of cold (downslope mountain winds that force the low level warmer air in the valley to

  18. Impact of real world driving pattern and all-electric range on battery sizing and cost of plug-in hybrid electric two-wheeler

    Science.gov (United States)

    Amjad, Shaik; Rudramoorthy, R.; Neelakrishnan, S.; Varman, K. Sri Raja; Arjunan, T. V.

    2011-03-01

    This study addresses the impact of an actual drive pattern on the sizing and cost of a battery pack for a plug-in hybrid electric two-wheeler. To estimate the daily average travel distance in fixing the all-electric range of two wheelers, a study conducted in Coimbatore city is presented. A MATLAB simulation model developed for estimating the energy and power requirements in an all-electric strategy using an Indian driving cycle (IDC) and a real-world driving pattern are discussed. The simulation results reveal the impact of the real-world driving pattern on energy consumption and also the influence of all-electric range in sizing the battery pack. To validate the results, a plug-in hybrid electric two-wheeler developed by modifying a standard two-wheeler has been tested on the road with the help of the IDC simulator kit. An annual battery cost comparison shows that nickel-metal-hydride batteries are more economical and suitable for in plug-in hybrid electric two-wheelers.

  19. Electro-hydrodynamic generation of monodisperse nanoparticles in the sub-10 nm size range from strongly electrolytic salt solutions: governing parameters of scaling laws

    Energy Technology Data Exchange (ETDEWEB)

    Maisser, Anne, E-mail: a.maisser@tudelft.nl [Delft University of Technology (Netherlands); Attoui, Michel B. [LISA, UMR CNRS University Paris Est Creteil, University Paris-Diderot (France); Ganan-Calvo, Alfonso M. [Universidad de Sevilla, ESI (Spain); Szymanski, Wladyslaw W. [University of Vienna, Faculty of Physics (Austria)

    2013-01-15

    A charge reduced electro-hydrodynamic atomization (EHDA) device has been used to generate airborne salt clusters in the sub 10 nm size range. The focus of this study on that specific sub-micron range of electrospray droplets with relatively high electrical conductivities and permittivities aims to address the still existing controversy on the scaling laws of electrosprayed droplet diameters. In this study different concentrations of sodium chloride and potassium chloride-both show strong electrolytic behavior-have been electrosprayed from solutions in pure water, or from aqueous ammonium acetate buffer liquids of varying concentrations. The dry residue salt cluster diameter generated by the EHDA process have been measured using a differential mobility analyzer. The initial droplet diameter has been determined indirectly from the measured particle size following the steps of Chen et al. (J Aerosol Sci 26:963-977, 1995). Results have been compared to existing scaling laws valid for direct droplet measurements. They can be interpreted concisely on the basis of a realistic hypothesis on possible electrochemical effects taking place and affecting the droplet and thus nanoparticle formation in EHDA. The hypothesis developed in this work and the comparison with the experimental results are shown and discussed in the manuscript.

  20. Evaluation of the size segregation of elemental carbon (EC) emission in Europe: influence on the simulation of EC long-range transportation

    Science.gov (United States)

    Chen, Ying; Cheng, Ya-Fang; Nordmann, Stephan; Birmili, Wolfram; Denier van der Gon, Hugo A. C.; Ma, Nan; Wolke, Ralf; Wehner, Birgit; Sun, Jia; Spindler, Gerald; Mu, Qing; Pöschl, Ulrich; Su, Hang; Wiedensohler, Alfred

    2016-02-01

    Elemental Carbon (EC) has a significant impact on human health and climate change. In order to evaluate the size segregation of EC emission in the EUCAARI inventory and investigate its influence on the simulation of EC long-range transportation in Europe, we used the fully coupled online Weather Research and Forecasting/Chemistry model (WRF-Chem) at a resolution of 2 km focusing on a region in Germany, in conjunction with a high-resolution EC emission inventory. The ground meteorology conditions, vertical structure and wind pattern were well reproduced by the model. The simulations of particle number and/or mass size distributions were evaluated with observations at the central European background site Melpitz. The fine mode particle concentration was reasonably well simulated, but the coarse mode was substantially overestimated by the model mainly due to the plume with high EC concentration in coarse mode emitted by a nearby point source. The comparisons between simulated EC and Multi-angle Absorption Photometers (MAAP) measurements at Melpitz, Leipzig-TROPOS and Bösel indicated that the coarse mode EC (ECc) emitted from the nearby point sources might be overestimated by a factor of 2-10. The fraction of ECc was overestimated in the emission inventory by about 10-30 % for Russia and 5-10 % for Eastern Europe (e.g., Poland and Belarus). This incorrect size-dependent EC emission results in a shorter atmospheric life time of EC particles and inhibits the long-range transport of EC. A case study showed that this effect caused an underestimation of 20-40 % in the EC mass concentration in Germany under eastern wind pattern.

  1. Patterns of anogenital swelling size and their endocrine correlates during ovulatory cycles and early pregnancy in free-ranging barbary macaques (Macaca sylvanus) of Gibraltar.

    Science.gov (United States)

    Möhle, U; Heistermann, M; Dittami, J; Reinberg, V; Wallner, B; Hodges, J K

    2005-08-01

    In macaques and other cercopithecoid primates, large anogenital swellings (AS) are generally found only in those species in which reproduction is not seasonally restricted. In this respect, the Barbary macaque is unusual because while it shows a marked degree of reproductive seasonality, it also exhibits a striking, exaggerated swelling of the circumanal region and labia. Information on the characteristics of AS in female Barbary macaques is limited in that it is largely based on semiquantitative assessments of swelling size, and there are no data on endocrine parameters associated with AS during ovulatory cycles or early pregnancy. In the present study, we combined quantitative measurements of four swelling size parameters (AS width, height, and depth, and labial width) using a video-imaging technique with fecal estrogen and progestagen determinations in free-ranging females of the Gibraltar Barbary macaque population to 1) characterize the pattern of AS throughout the mating season and early gestation, and 2) examine the relationships among changes in swelling size and endocrine parameters. The patterns of all four swelling parameters correlated significantly with one another, although measures of AS depth and labial width were difficult to obtain. Using the product of AS height and width, the data demonstrate that the occurrence of AS is highly seasonal, with pronounced cyclical changes during the mating season and early pregnancy. Furthermore, the swelling cycles are characterized by progressive size increases from the early to the late follicular phase, in association with an elevated estrogen:progestagen (E:P) ratio, with ovulation occurring during the maximum swelling phase. The results also demonstrated a conspicuous postconception increase in swelling between days 18-30 of gestation. The postconception swellings were on average 80% of the size of that of the conception cycles, and were preceded by a large increase in fecal estrogen levels and the E:P ratio

  2. Effects of diurnal temperature range on adult size and emergence times from diapausing pupae in Papilio glaucus and p.canadensis (Papilionidae)

    Institute of Scientific and Technical Information of China (English)

    J. Mark Scriber; Brittany Sonke

    2011-01-01

    With recent climate warming trends,both the increase in thermal variance (i.e.,diurnal temperature range; DTR) as well as increased mean temperature may impact many different organisms,especially poikilothermic invertebrates.Predictions of insect developmental rates using degree-days (thermal unit accumulations above the developmental base threshold of the insect) are based on daily mean temperatures,regardless of DTR.However,non-linearity and variance in the means and extremes are often ignored.The role of thermal variance (e.g.,daily temperature extremes and DTR) was evaluated experimentally for two swallowtail butterfly sister species using a common day/night photoperiod of 18:6 h photo:scoto-phase and corresponding daytime thermophase and nighttime cryophase periods of 22:22℃ (constant 22℃),24:16℃,and 26:10℃ (all three treatments had the same daily mean and the same degree-day accumulations).Although developmental rates ofpost-diapause pupae were largely unaffected for both species,our results show that sizes in P.canadensis females (but not males) were smaller in the treatments with more variance (26℃:10℃) compared to constant 22℃.Such potentially significant impacts of size reduction in P.canadensis females were not observed in P.glaucus males or females under the same series ofthermo-period treatments.

  3. Particle size measurements in the submicron range by the differential electromobility technique: comparison of aerosols from thermospray, ultrasonic, pneumatic and frit-type nebulizers

    Science.gov (United States)

    Clifford, Robert H.; Tan, Hsiaoming; Liu, Huiying; Montaser, Akbar; Zarrin, Fahimeh; Keady, Patricia B.

    1993-08-01

    The differential electromobility technique was used for the comparison of droplet- and particle-size distributions in the 0.02-0.8 μm range for six nebulization systems often used in inductively coupled plasma (ICP) spectrometry: a thermospray nebulizer coupled to a membrane separator (TNMS); two ultrasonic nebulizers (USNs) used with desolvation; one pneumatic nebulizer (PN) used with and without desolvation; and a frit-type nebulizer. In general, volume concentration (volume of droplets or particles per cubic centimeter of injector gas) increased with NaCl concentration, and it was greater for TNMS followed by USNs compared to other nebulizers. For the desolvated aerosol produced by PN and USN, volume concentration was found to be independent of the temperature (140-180°C) of the heating tube for the desolvation device. As the nebulizer tip temperature in thermospray nebulization was varied from 160 to 240°C, a larger volume concentration of desolvated aerosol was produced. Size distributions shifted towards larger particles with increasing NaCl concentration. The implications of these observations in plasma spectrochemical measurements are discussed.

  4. Characteristics of dimethylaminium and trimethylaminium in atmospheric particles ranging from supermicron to nanometer sizes over eutrophic marginal seas of China and oligotrophic open oceans.

    Science.gov (United States)

    Yu, Peiran; Hu, Qingjing; Li, Kai; Zhu, Yujiao; Liu, Xiaohuan; Gao, Huiwang; Yao, Xiaohong

    2016-12-01

    In this study, we characterized dimethylaminium (DMA(+)) and trimethylaminium (TMA(+)) in size-segregated atmospheric particles during three cruise campaigns in the marginal seas of China and one cruise campaign mainly in the northwest Pacific Ocean (NWPO). An 14-stage nano-MOUDI sampler was utilized for sampling atmospheric particles ranging from 18μm to 0.010μm. Among the four cruise campaigns, the highest concentrations of DMA(+) and TMA(+) in PM10 were observed over the South Yellow Sea (SYS) in August 2015, i.e., 0.76±0.12nmolm(-3) for DMA(+) (average value±standard deviation) and 0.93±0.13nmolm(-3) for TMA(+). The lowest values were observed over the NWPO in April 2015, i.e., 0.28±0.16nmolm(-3) for DMA(+) and 0.22±0.12nmolm(-3) for TMA(+). In general, size distributions of the two ions exhibited a bi-modal pattern, i.e., one mode at 0.01-0.1μm and the other at 0.1-1.8μm. The two ions' mode at 0.01-0.1μm was firstly observed. The mode was largely enhanced in samples collected over the SYS in August 2015, leading to high mole ratios of (DMA(+)+TMA(+))/NH4(+) in PM0.1 (0.4±0.8, median value±standard deviation) and the ions' concentrations in PM0.1 accounting for ~10% and ~40% of their corresponding concentrations in PM10. This implied that (DMA(+)+TMA(+)) likely played an important role in neutralizing acidic species in the smaller particles. Using SO4(2-), NO3(-) and NH4(+) as references, we confirm that the elevated concentrations of DMA(+) and TMA(+) in the 0.01-0.1μm size range were probably real signals rather than sampling artifacts.

  5. Scaling up from epidemiology to biogeography: local infection patterns predict geographical distribution in fish parasites

    NARCIS (Netherlands)

    Poulin, R.; Blanar, C.A.; Thieltges, D.W.; Marcogliese, D.J.

    2012-01-01

    Aim We investigated how the spatial distribution of parasites, measured as either their geographical range size or their frequency of occurrence among localities, relates to either their average local abundance or the variance in their abundance among localities where they occur. Location We used da

  6. Geographic constraints on social network groups.

    Directory of Open Access Journals (Sweden)

    Jukka-Pekka Onnela

    Full Text Available Social groups are fundamental building blocks of human societies. While our social interactions have always been constrained by geography, it has been impossible, due to practical difficulties, to evaluate the nature of this restriction on social group structure. We construct a social network of individuals whose most frequent geographical locations are also known. We also classify the individuals into groups according to a community detection algorithm. We study the variation of geographical span for social groups of varying sizes, and explore the relationship between topological positions and geographic positions of their members. We find that small social groups are geographically very tight, but become much more clumped when the group size exceeds about 30 members. Also, we find no correlation between the topological positions and geographic positions of individuals within network communities. These results suggest that spreading processes face distinct structural and spatial constraints.

  7. Geographical information systems

    DEFF Research Database (Denmark)

    Möller, Bernd

    2004-01-01

    The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management.......The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management....

  8. Geographical information systems

    DEFF Research Database (Denmark)

    Möller, Bernd

    2004-01-01

    The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management.......The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management....

  9. Geographic Media Literacy

    Science.gov (United States)

    Lukinbeal, Chris

    2014-01-01

    While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

  10. Range_Extent_15

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS layer "Range_extent_15" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris nereis) in mainland...

  11. Succession of Pelagic Organisms in the Size Range 0·5-200 μm During a Diatom Bloom in Otsuchi Bay, Japan

    Science.gov (United States)

    Tsuda, Atsushi; Sugisaki, Hiroya; Takahashi, Koji; Furuya, Ken

    1994-08-01

    The succession of pelagic organisms in the approximate size range 0·5-200 μm was investigated during a spring diatom bloom in Otsuchi Bay on the Pacific coast of northern Japan. The diatom bloom lasted 3 weeks in the middle of the period examined. The study period was divided into three phases: pre-bloom, bloom and post-bloom. Mesodinium rubrum, an autotrophic ciliate, was abundant in the pre-bloom phase, when vertical mixing was intense. During the bloom phase, the biomass of organisms other than diatoms themselves and bacteria was depressed. A bacterial peak was observed 4 days after the diatom peak and peaks of nano-autotrophs and -heterotrophs occurred after 14 days. Phototrophic picoplankton showed a biomass peak at the same time as nanoplankton. Grazing on diatoms by the copepod population was shown by the occurrences of faecal pellets and copepod nauplii during and after the bloom phase. These results suggest that production of copepods and bacteria depended only on the diatom bloom directly, and that heterotrophic micro-protista depended on the production of pico- and nano-autotrophs in the post-bloom phase.

  12. Geographical National Condition and Complex System

    Directory of Open Access Journals (Sweden)

    WANG Jiayao

    2016-01-01

    Full Text Available The significance of studying the complex system of geographical national conditions lies in rationally expressing the complex relationships of the “resources-environment-ecology-economy-society” system. Aiming to the problems faced by the statistical analysis of geographical national conditions, including the disunity of research contents, the inconsistency of range, the uncertainty of goals, etc.the present paper conducted a range of discussions from the perspectives of concept, theory and method, and designed some solutions based on the complex system theory and coordination degree analysis methods.By analyzing the concepts of geographical national conditions, geographical national conditions survey and geographical national conditions statistical analysis, as well as investigating the relationships between theirs, the statistical contents and the analytical range of geographical national conditions are clarified and defined. This investigation also clarifies the goals of the statistical analysis by analyzing the basic characteristics of the geographical national conditions and the complex system, and the consistency between the analysis of the degree of coordination and statistical analyses. It outlines their goals, proposes a concept for the complex system of geographical national conditions, and it describes the concept. The complex system theory provides new theoretical guidance for the statistical analysis of geographical national conditions. The degree of coordination offers new approaches on how to undertake the analysis based on the measurement method and decision-making analysis scheme upon which the complex system of geographical national conditions is based. It analyzes the overall trend via the degree of coordination of the complex system on a macro level, and it determines the direction of remediation on a micro level based on the degree of coordination among various subsystems and of single systems. These results establish

  13. Urban air quality in a mid-size city - PM2.5 composition, sources and identification of impact areas: From local to long range contributions

    Science.gov (United States)

    Squizzato, Stefania; Cazzaro, Marta; Innocente, Elena; Visin, Flavia; Hopke, Philip K.; Rampazzo, Giancarlo

    2017-04-01

    Urban air quality represents a major public health burden and is a long-standing concern to European citizens. Combustion processes and traffic-related emissions represent the main primary particulate matter (PM) sources in urban areas. Other sources can also affect air quality (e.g., secondary aerosol, industrial) depending on the characteristics of the study area. Thus, the identification and the apportionment of all sources is of crucial importance to make effective corrective decisions within environmental policies. The aim of this study is to evaluate the impacts of different emissions sources on PM2.5 concentrations and compositions in a mid-size city in the Po Valley (Treviso, Italy). Data have been analyzed to highlight compositional differences (elements and major inorganic ions), to determine PM2.5 sources and their contributions, and to evaluate the influence of air mass movements. Non-parametric tests, positive matrix factorization (PMF), conditional bivariate probability function (CBPF), and concentration weighted trajectory (CWT) have been used in a multi-chemometrics approach to understand the areal-scale (proximate, local, long-range) where different sources act on PM2.5 levels and composition. Results identified three levels of scale from which the pollution arose: (i) a proximate local scale (close to the sampling site) for traffic non-exhaust and resuspended dust sources; (ii) a local urban scale (including both sampling site and areas close to them) for combustion and industrial; and (iii) a regional scale characterized by ammonium nitrate and ammonium sulfate. This approach and results can help to develop and adopt better air quality policy action.

  14. Geographic polymorphism of P element in populations of Drosophila sturtevanti

    Directory of Open Access Journals (Sweden)

    Luciane M. de Almeida

    2003-01-01

    Full Text Available The aim of this report was to detect full-sized P element sequences in eight strains of Drosophila sturtevanti populations from distant geographic regions and to assess the structural geographic variation among P element sequences. PCR analysis confirmed the presence of a putative complete P element in all strains. Southern blot analysis indicated bands shared by all strains, and bands restricted to geographically related strains. Parsimony analysis corroborated the hybridization pattern that reflected the geographic relationships.

  15. Airports Geographic Information System -

    Data.gov (United States)

    Department of Transportation — The Airports Geographic Information System maintains the airport and aeronautical data required to meet the demands of the Next Generation National Airspace System....

  16. Ecological specialization and population size in a biodiversity hotspot: How rare species avoid extinction

    OpenAIRE

    S. E. Williams; Y. M. Williams; Vanderwal, J.; Isaac, J. L.; L. P. Shoo; Johnson, C. N.

    2009-01-01

    Species with narrow environmental niches typically have small geographic ranges. Small range size is, in turn, often associated with low local abundance. Together, these factors should mean that ecological specialists have very small total populations, putting them at high risk of extinction. But some specialized and geographically restricted species are ancient, and some ecological communities have high proportions of rare and specialized endemics. We studied niche characteristics and patter...

  17. Assessing Geographic Information Enhancement

    NARCIS (Netherlands)

    Van Loenen, B.; Zevenbergen, J.

    2010-01-01

    Assessment of geographic information infrastructures (or spatial data infrastructures) is increasingly attracting the attention of researchers in the Geographic information (GI) domain. Especially the assessment of value added GI appears to be complex. By applying the concept of value chain analysis

  18. Environmental geographic information system.

    Energy Technology Data Exchange (ETDEWEB)

    Peek, Dennis W; Helfrich, Donald Alan; Gorman, Susan

    2010-08-01

    This document describes how the Environmental Geographic Information System (EGIS) was used, along with externally received data, to create maps for the Site-Wide Environmental Impact Statement (SWEIS) Source Document project. Data quality among the various classes of geographic information system (GIS) data is addressed. A complete listing of map layers used is provided.

  19. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  20. Patterns of genome size variation in snapping shrimp.

    Science.gov (United States)

    Jeffery, Nicholas W; Hultgren, Kristin; Chak, Solomon Tin Chi; Gregory, T Ryan; Rubenstein, Dustin R

    2016-06-01

    Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.

  1. MULTIMEDIA ON GEOGRAPHIC NETWORK

    OpenAIRE

    Merlanti, Danilo

    2012-01-01

    In this thesis we investigate the topic of the multimedia contents distribution on a geo- graphic network which is a rarefied and huge field. First of all we have to classify the main parts necessary in the multimedia distribution on a geographic network. The main aspects of a geographic network that will be highlighted in this thesis are: the mechanism used to retrieve the sources of the multimedia content; in the case of the peer-to-peer network on geographic network one of t...

  2. Structural composition of organic matter in particle-size fractions of soils along a climo-biosequence in the main range of Peninsular Malaysia

    Science.gov (United States)

    Jafarzadeh-Haghighi, Amir Hossein; Shamshuddin, Jusop; Hamdan, Jol; Zainuddin, Norhazlin

    2016-09-01

    Information on structural composition of organic matter (OM) in particle-size fractions of soils along a climo-biosequence is sparse. The objective of this study was to examine structural composition and morphological characteristics of OM in particle-size fractions of soils along a climo-biosequence in order to better understand the factors and processes affecting structural composition of soil organic matter. To explore changes in structural composition of OM in soils with different pedogenesis, the A-horizon was considered for further analyses including particle-size fractionation, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM). Due to the increase in the thickness of organic layer with increasing elevation, the A-horizon was situated at greater depth in soils of higher elevation. The relationship between relative abundances of carbon (C) structures and particle-size fractions was examined using principal component analysis (PCA). It was found that alkyl C (20.1-73.4%) and O-alkyl C (16.8-67.7%) dominated particle-size fractions. The proportion of alkyl C increased with increasing elevation, while O-alkyl C showed an opposite trend. Results of PCA confirmed this finding and showed the relative enrichment of alkyl C in soils of higher elevation. Increase in the proportion of alkyl C in 250-2000 μm fraction is linked to selective preservation of aliphatic compounds derived from root litter. SEM results showed an increase in root contribution to the 250-2000 μm fraction with increasing elevation. For the responsible for the relative enrichment of alkyl C. This study demonstrates that changes in structural composition of OM in particle-size fractions of soils along the studied climo-biosequence are attributed to site-specific differences in pedogenesis as a function of climate and vegetation.

  3. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savanna

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.; Gort, Gerrit; Komdeur, Jan

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species' migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of ra

  4. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savannah

    NARCIS (Netherlands)

    Buij, R.; Croes, B.M.; Gort, G.; Komdeur, J.

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species’ migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of ra

  5. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savanna

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.; Gort, Gerrit; Komdeur, Jan

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species' migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of ra

  6. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savannah

    NARCIS (Netherlands)

    Buij, R.; Croes, B.M.; Gort, G.; Komdeur, J.

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species’ migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of ra

  7. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savannah

    NARCIS (Netherlands)

    Buij, R.; Croes, B.M.; Gort, G.; Komdeur, J.

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species’ migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of

  8. The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savanna

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.; Gort, Gerrit; Komdeur, Jan

    2013-01-01

    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species' migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of

  9. Female sexual behavior and sexual swelling size as potential cues for males to discern the female fertile phase in free-ranging Barbary macaques (Macaca sylvanus) of Gibraltar.

    Science.gov (United States)

    Brauch, Katrin; Pfefferle, Dana; Hodges, Keith; Möhle, Ulrike; Fischer, Julia; Heistermann, Michael

    2007-09-01

    Although female catarrhine primates show cyclic changes in sexual behavior and sexual swellings, the value of these sexual signals in providing information to males about timing of the fertile phase is largely unclear. Recently, we have shown that in Barbary macaques, males receive information from females which enables them to discern the fertile phase and to focus their reproductive effort accordingly. Here, we investigate the nature of the cues being used by examining female sexual behavior and the size of sexual swelling as potential indicators of the fertile phase. We collected behavioral data and quantified swelling size using digital images of 11 females of the Gibraltar Barbary macaque population and related the data to the time of ovulation and the fertile phase as determined from fecal hormone analysis. We found that rates of female sexual behaviors were not correlated with female estrogen levels and did not significantly differ between the fertile and non-fertile phases of the cycle. In contrast, swelling size was significantly correlated with female estrogen levels and increased predictably towards ovulation with size being maximal during the fertile phase. Moreover, frequencies of male ejaculatory copulations showed a strong positive correlation with swelling size and highest rates were found during maximum swelling. Our data provide strong evidence that female Barbary macaques honestly signal the probability of fertility through sexual swelling and that males apparently use this information to time their mating activities. Honest advertising of the fertile phase might be part of a female strategy to manipulate male mating behavior for their own advantage, such as ensure fertilization with high quality sperm or influence paternity outcome.

  10. Tamanho da área de vida e padrão de uso do espaço em grupos de sagüis, Callithrix jacchus (Linnaeus (Primates, Callitrichidae Home range size and pattern of range use in common marmoset groups, Callithrix jacchus (Linnaeus (Primates, Callitrichidae

    Directory of Open Access Journals (Sweden)

    Carla Soraia Soares de Castro

    2003-03-01

    Full Text Available The influence of abundance and distribution of fruits and gums resources in home range size and pattern of range use were investigated in Callithrix jacchus. From October 1996 to January 1998 two groups (QT and PB that lived in a National Forest/IBAMA-RN in northeastern Brazil (6º5'S, 35º12'W, were observed once a week by instantaneous scan sampling. The frequency of quadrant's visit in the home range was recorded at five minute intervals. Trees used for feeding on fruits and/or gum by the study groups were marked with flagging tape and numbered. Samples of the food items were collected for identification. Data on the temporal variation in fruits abundance was based on the monthly phenological observations of the marked trees. Study groups showed small home range size (QT: 2.4 ha and PB: 0.7 ha. No significant differences in home range size between dry and wet months were found, but groups showed a tendency to broadened the range use in the wet months. This revealed a behavioral strategy which marmosets exploited more gums face to decreased in fruits abundance. The abundance and distribution in clusters of fruits and gums resources influenced the pattern of range use and home range size.

  11. Plankton Analysis by Automated Submersible Imaging Flow Cytometry: Transforming a Specialized Research Instrument into a Broadly Accessible Tool and Extending its Target Size Range

    Science.gov (United States)

    2012-09-30

    the particles suspended in seawater is crucial to an understanding of the biology , optics, and geochemistry of the oceans. The composition and size...been interested in marine applications of flow cytometry, and had sold several slightly-modified instruments (called Influx Marina ) to oceanographic...our WHOI Biology Department colleague Don Anderson, who was funded by NSF to purchase several Environmental Sample Processors (ESP), to be

  12. How do low dispersal species establish large range sizes? The case of the water beetle Graphoderus bilineatus

    DEFF Research Database (Denmark)

    Iversen, Lars Lønsmann; Rannap, Riinu; Thomsen, Philip Francis

    2013-01-01

    dispersal. We recorded the presence/absence of G. bilineatus and measured 14 habitat and 20 landscape variables at 228 localities in Estonia, Poland and Sweden within the core range of the species. Using information theory and average multivariate logistic regression models we determined that presence of G....... bilineatus depended on landscape connectivity, distance to a possible source habitat, and stability of the site; however, specificity of habitat characteristics was not vital for the species. We reason that the large range of G. bilineatus is best explained by the historical combination of lakes, river...... measures for G. bilineatus and similar philopatric species. Instead, conservation actions should be focused at the landscape level to ensure a long-term viability of such species across their range....

  13. Geographic names of the Antarctic

    Science.gov (United States)

    ,; ,; ,; ,; Alberts, Fred G.

    1995-01-01

    This gazetteer contains 12,710 names approved by the United States Board on Geographic Names and the Secretary of the Interior for features in Antarctica and the area extending northward to the Antarctic Convergence. Included in this geographic area, the Antarctic region, are the off-lying South Shetland Islands, the South Orkney Islands, the South Sandwich Islands, South Georgia, Bouvetøya, Heard Island, and the Balleny Islands. These names have been approved for use by U.S. Government agencies. Their use by the Antarctic specialist and the public is highly recommended for the sake of accuracy and uniformity. This publication, which supersedes previous Board gazetteers or lists for the area, contains names approved as recently as December 1994. The basic name coverage of this gazetteer corresponds to that of maps at the scale of 1:250,000 or larger for coastal Antarctica, the off-lying islands, and isolated mountains and ranges of the continent. Much of the interior of Antarctica is a featureless ice plateau. That area has been mapped at a smaller scale and is nearly devoid of toponyms. All of the names are for natural features, such as mountains, glaciers, peninsulas, capes, bays, islands, and subglacial entities. The names of scientific stations have not been listed alphabetically, but they may appear in the texts of some decisions. For the names of submarine features, reference should be made to the Gazetteer of Undersea Features, 4th edition, U.S. Board on Geographic Names, 1990.

  14. Symposium on Geographic Information Systems.

    Science.gov (United States)

    Felleman, John, Ed.

    1990-01-01

    Six papers on geographic information systems cover the future of geographic information systems, land information systems modernization in Wisconsin, the Topologically Integrated Geographic Encoding and Referencing (TIGER) System of the U.S. Bureau of the Census, satellite remote sensing, geographic information systems and sustainable development,…

  15. Geographic variation in Caluromys derbianus and Caluromys lanatus (Didelphimorphia: Didelphidae)

    OpenAIRE

    Raul Fonseca; Diego Astúa

    2015-01-01

    We analyzed the geographic variations in the shape and size of the cranium and mandible of two woolly opossums, Caluromys derbianus and Caluromys lanatus. Using geometric morphometrics we analyzed 202 specimens of C. derbianus and 123 specimens of C. lanatus, grouped in 7 and 9 populations, respectively. We found sexual dimorphism in shape variables only in the dorsal view of the cranium of Caluromys derbianus, which is not associated with geographical origin. We detected geographic variation...

  16. Influence of geography and climate on patterns of cell size and body size in the lizard Anolis carolinensis.

    Science.gov (United States)

    Goodman, Rachel M; Echternacht, Arthur C; Hall, Jim C; Deng, Lihan D; Welch, Jessica N

    2013-06-01

    Geographic patterns in body size are often associated with latitude, elevation, or environmental and climatic variables. This study investigated patterns of body size and cell size of the green anole lizard, Anolis carolinensis, and potential associations with geography or climatic variables. Lizards were sampled from 19 populations across the native range, and body size, red blood cell size and size and number of muscle cells were measured. Climatic data from local weather stations and latitude and longitude were entered into model selection with Akaike's information criterion to explain patterns in cell and body sizes. Climatic variables did not drive any major patterns in cell size or body size; rather, latitude and longitude were the best predictors of cell and body size. In general, smaller body and cell sizes in Florida anoles drove geographic patterns in A. carolinensis. Small size in Florida may be attributable to the geological history of the peninsular state or the unique ecological factors in this area, including a recently introduced congener. In contrast to previous studies, we found that A. carolinensis does not follow Bergmann's rule when the influence of Florida is excluded. Rather, the opposite pattern of larger lizards in southern populations is evident in the absence of Florida populations, and mirrors the general pattern in squamates. Muscle cell size was negatively related to latitude and red blood cell size showed no latitudinal trend outside of Florida. Different patterns in the sizes of the 2 cell types confirm the importance of examining multiple cell types when studying geographic variation in cell size.

  17. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...

  18. Making Geographical Futures

    Science.gov (United States)

    Morgan, John

    2015-01-01

    Although there are surprisingly few academic books about geography with the term "future" or "futures" in their titles, this paper indicates that for much of the twentieth century geographers contributed to important discussions about the shape of worlds to come. The paper offers a review of these debates within Anglo-American…

  19. Geographic profiling survey

    NARCIS (Netherlands)

    Emeno, Karla; Bennell, Craig; Snook, Brent; Taylor, Paul Jonathon

    Geographic profiling (GP) is an investigative technique that involves predicting a serial offender?s home location (or some other anchor point) based on where he or she committed a crime. Although the use of GP in police investigations appears to be on the rise, little is known about the procedure

  20. GEOGRAPHICAL ANALYSIS OF FOREST FLORA OF THE CENTRAL CISCAUCASIA

    Directory of Open Access Journals (Sweden)

    I. L. Ivanov

    2014-01-01

    Full Text Available Abstract. Aim. Forest flora of the Central Ciscaucasia in General is a relict, geographically situated in the steppe zone. Composing flora elements have different types of habitats, concentrated in the natural physical-geographical unit where isolated from the main habitats. Comparative analysis of the geographic, ecological and systematic components of forest flora will provide data about the correlation of these parameters identify the leading group. Location. The Central CiscaucasiaMethods. We made the geographical and systematic ranges of forest flora of the Central Ciscaucasia and their comparative analysis is conducted.Results. Geographical analysis of forest flora of the Central Ciscaucasia revealed 16 geographical elements, grouped in 6 categories, among which is the predominant group of boreal geographical elements. It is established that the leading geographical elements are Euro-Caucasian, Caucasian and Sub-Caucasian, numbering 189 species, and are half of the flora. Comparison with ecological spectrum showed that the sequence geographical elements completely different, here leading positions are occupied Northern species as ecologically more conservative, and the Caucasian demonstrate ecological plasticity. In a systematic relation matched warheads geographical and systematic spectra. The scope of the results. The results may be used in comparative Floristics, in its theoretical part in adjusting themodels of the Genesis of the flora.Conclusions. Thus, half of the geographical elements of the forest flora of the Central Ciscaucasia are linked in their distribution of Caucasian floristic province (Euro-Caucasian, Caucasian and Sub-Caucasian. These same geographical elements to predominate in the head part of the spectrum families. Most geographical elements have low ecological plasticity species, their components, do not go beyond the forest plant association, but geographical elements head part of the geographical range

  1. Macrophage reactivity to different polymers demonstrates particle size- and material-specific reactivity: PEEK-OPTIMA(®) particles versus UHMWPE particles in the submicron, micron, and 10 micron size ranges.

    Science.gov (United States)

    Hallab, Nadim James; McAllister, Kyron; Brady, Mark; Jarman-Smith, Marcus

    2012-02-01

    Biologic reactivity to orthopedic implant debris is generally the main determinant of long-term clinical performance where released polymeric particles of Ultra-high molecular weight polyethylene (UHMWPE) remain the most prevalent debris generated from metal-on-polymer bearing total joint arthroplasties. Polymeric alternatives to UHMWPE such as polyetherether-ketone (PEEK) may have increased wear resistance but the bioreactivity of PEEK-OPTIMA particles on peri-implant inflammation remains largely uncharacterized. We evaluated human monocyte/macrophage responses (THP-1s and primary human) when challenged by PEEK-OPTIMA, UHMWPE, and X-UHMWPE particles of three particle sizes (0.7 um, 2 um, and 10 um) at a dose of 20 particles-per-cell at 24- and 48-h time points. Macrophage responses were measured using cytotoxicity assays, viability assays, proliferation assays and cytokine analysis (IL-1b, IL-6, IL-8, MCP-1, and TNF-α). In general, there were no significant differences between PEEK-OPTIMA, UHMWPE, and X-UHMWPE particles on macrophage viability or proliferation. However, macrophages demonstrated greater cytotoxicity responses to UHMWPE and X-UHMWPE than to PEEK-OPTIMA at 24 and 48 h, where 0.7 μm-UHMWPE particles produced the highest amount of cytotoxicity. Particles of X-UHMWPE more than PEEK-OPTIMA and UHMWPE induced IL-1β, IL-6, MCP-1, and TNF-α at 24 h, p UHMWPE particles, in that they induced less inflammatory cytokine responses and thus, in part, demonstrates that PEEK-OPTIMA implant debris does not represent an increased inflammatory risk over that of UHMWPE.

  2. Geographic, seasonal, and diurnal surface behavior of harbor porpoises

    DEFF Research Database (Denmark)

    Teilmann, Jonas; Christiansen, C.T.; Kjellerup, Sanne;

    2013-01-01

    are essential information on the status and management of the species. Thirty-five free-ranging harbor porpoises (Phocoena phocoena) were tracked in the region between the Baltic and the North Sea for 25-349 d using Argos satellite transmitters. No differences were found in surface behavior between geographical...... areas or the size of the animals. Slight differences were found between the two sexes and time of day. Surface time peaked in April, where 6% was spent with the transmitter above surface and 61.5% between 0 and 2 m depth, while the minimum values occurred in February (3.4% and 42.5%, respectively......). The analyses reveal that individual variation among porpoises is the most important factor in explaining variation in surface rates. However, the large number of animals documented in the present study covering a wide range of age and sex groups justifies the use of the seasonal average surface times...

  3. Fundamental procedures of geographic information analysis

    Science.gov (United States)

    Berry, J. K.; Tomlin, C. D.

    1981-01-01

    Analytical procedures common to most computer-oriented geographic information systems are composed of fundamental map processing operations. A conceptual framework for such procedures is developed and basic operations common to a broad range of applications are described. Among the major classes of primitive operations identified are those associated with: reclassifying map categories as a function of the initial classification, the shape, the position, or the size of the spatial configuration associated with each category; overlaying maps on a point-by-point, a category-wide, or a map-wide basis; measuring distance; establishing visual or optimal path connectivity; and characterizing cartographic neighborhoods based on the thematic or spatial attributes of the data values within each neighborhood. By organizing such operations in a coherent manner, the basis for a generalized cartographic modeling structure can be developed which accommodates a variety of needs in a common, flexible and intuitive manner. The use of each is limited only by the general thematic and spatial nature of the data to which it is applied.

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

    Science.gov (United States)

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

    2016-11-27

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

  5. Do differences in the administrative structure of populations confound comparisons of geographic health inequalities?

    LENUS (Irish Health Repository)

    Jackson, Andrew L

    2010-08-18

    Abstract Background Geographical health inequalities are naturally described by the variation in health outcomes between areas (e.g. mortality rates). However, comparisons made between countries are hampered by our lack of understanding of the effect of the size of administrative units, and in particular the modifiable areal unit problem. Our objective was to assess how differences in geographic and administrative units used for disseminating data affect the description of health inequalities. Methods Retrospective study of standard populations and deaths aggregated by administrative regions within 20 European countries, 1990-1991. Estimated populations and deaths in males aged 0-64 were in 5 year age bands. Poisson multilevel modelling was conducted of deaths as standardised mortality ratios. The variation between regions within countries was tested for relationships with the mean region population size and the unequal distribution of populations within each country measured using Gini coefficients. Results There is evidence that countries whose regions vary more in population size show greater variation and hence greater apparent inequalities in mortality counts. The Gini coefficient, measuring inequalities in population size, ranged from 0.1 to 0.5 between countries; an increase of 0.1 was accompanied by a 12-14% increase in the standard deviation of the mortality rates between regions within a country. Conclusions Apparently differing health inequalities between two countries may be due to differences in geographical structure per se, rather than having any underlying epidemiological cause. Inequalities may be inherently greater in countries whose regions are more unequally populated.

  6. Geographical orientation. An integral geoperspective

    Directory of Open Access Journals (Sweden)

    Cristóbal Cobo Arízaga

    2013-12-01

    This approach seeks to create a new line of discussion, to launch a proposal that is scientifically challenging to the hegemony of geographical thought and that provides new geographical rationality structures.

  7. [Research progress on the risk factors of geographic tongue].

    Science.gov (United States)

    Huamei, Yang; Yu, Zhou; Xin, Zeng; Ga, Liao; Qianming, Chen

    2015-02-01

    Geographic tongue, also called benign migratory glossitis, is a common and superficial benign inflammatory disorder that affects the tongue epithelium. The majority of geographic tongue lesions typically manifest as irregular central erythematous patches. These lesions, which are caused by the loss of filiform papillae, are defined by an elevated whitish band-like border that can change location, size, and pattern over a period of time. Histological observations of the oral mucosa affected by geographic tongue revealed nonspecific inflammation. Some reports described cases of migratory stomatitis, wherein lesions simultaneously manifested on the extra lingual oral mucosa. This condition is also called ectopic geographic tongue, which is clinically and histologically similar to the type normally confined to the tongue. In most cases, patients are asymptomatic and do not require treatment. The condition may spontaneously exhibit periods of remission and exacerbation with good prognosis. The specific etiology of geographic tongue remains unknown. Geographic tongue is age-related and is prevalent among young individuals. Various etiological factors that have been suggested in literature include immunological factors, genetic factors, atopic or allergic tendency, emotional stress, tobacco consumption, hormonal disturbances, and zinc deficiency. Geographic tongue may coexist with other disorders, such as fissured tongue, psoriasis, diabetes mellitus, gastroin- testinal diseases, burning mouth syndrome, and Down syndrome. Experts currently disagree on whether geographic tongue is an oral manifestation of psoriasis. Moreover, some scholars suggest that geographic tongue is a prestage of fissured tongue. The objective of this review is to summarize current research on risk factors of geographic tongue.

  8. Range size patterns in European freshwater trematodes

    DEFF Research Database (Denmark)

    Thieltges, David; Hof, Christian; Borregaard, Michael Krabbe

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes. Location European freshwaters. Methods We extracted distributional data for 564 freshwater trematodes across 25...

  9. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...... inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

  10. Study of the chemical interaction between the beryllium powders of different particles size and the air in the temperature range 500-1000degC form the viewpoint of ITER safety

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, D.A. [State Scientific Center of Russian Federation, Moscow (Russian Federation); Konovalov, Y.V.; Gorokhov, V.A.; Levin, V.B.; Chekhlatov, G.M.; Khomutov, A.M.

    1998-01-01

    Under an effect of some factors characteristic for the ITER- operating condition a dense beryllium facing plasma can transit into various forms, changing its structural states. As a result of the bombardment of beryllium plasma facing components by ion fluxes, the production of a dust including the particles from a few micrometers to a few millimeters in size is possible. The specific features in the behaviour of various beryllium forms under emergency conditions are of an essential interest from the viewpoint of ITER safety. Some grades of powders of different average particles size (14-31 micron) have been produced in a given study, and their chemical interaction at high temperatures with air (500-1100degC), test duration effects simulating the emergency situation at ITER in the first approximation have been studied. The temperature dependence of beryllium powders (different particles size after disc abrased) interaction with air in the temperature range 500-1000degC at the exposure of 5 hours long for each temperature and kinetic dependence of interaction of these powders with air at 800degC for the exposure from half an hour to 7 hours long were studied. An analysis of granulometric weight fraction in the metallic and oxidized beryllium powders with different particles size has been done by the photosedimentational technique with the instrument `Analysette-20`. Construction of a mathematical model for the chemical interaction of beryllium powders with air at high temperatures have been carried out. (author)

  11. Molecular phylogenetics of geographically restricted Acropora species: implications for threatened species conservation.

    Science.gov (United States)

    Richards, Z T; Miller, D J; Wallace, C C

    2013-12-01

    To better understand the underlying causes of rarity and extinction risk in Acropora (staghorn coral), we contrast the minimum divergence ages and nucleotide diversity of an array of species with different range sizes and levels of threat. Time-calibrated Bayesian analyses based upon concatenated nuclear and mitochondrial sequence data implied contemporary range size and vulnerability are linked to species age. However, contrary to previous hypotheses that suggest geographically restricted Acropora species evolved in the Plio-Pleistocene, the molecular phylogeny depicts some Indo-Australian species have greater antiquity, diverging in the Miocene. Species age is not related to range size as a simple positive linear function and interpreting the precise tempo of evolution in this genus is greatly complicated by morphological homoplasy and a sparse fossil record. Our phylogenetic reconstructions provide new examples of how morphology conceals cryptic evolutionary relationships in this keystone genus, and offers limited support for the species groupings currently used in Acropora systematics. We hypothesize that in addition to age, other mechanisms (such as a reticulate ancestry) delimit the contemporary range of some Acropora species, as evidenced by the complex patterns of allele sharing and paraphyly we uncover. Overall, both new and ancient evolutionary information may be lost if geographically restricted and threatened Acropora species are forced to extinction. In order to protect coral biodiversity and resolve the evolutionary history of staghorn coral, further analyses based on comprehensive and heterogeneous morphological and molecular data utilizing reticulate models of evolution are needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. The Geographical Information System

    Directory of Open Access Journals (Sweden)

    Jürgen Schweikart

    2008-12-01

    Full Text Available The Geographical Information System, normally called GIS, is a tool for representing spatial relationships and real processes with the help of a model. A GIS is a system of hardware, software and staff for collecting, managing, analysing and representing geospatial information. For example, we can study the evolution of an infectious disease in a certain territory, perform market analysis, or locate the best ways to choose a new industrial site. In substance, it is data manipulation software for that allows us to have, both the graphic component, that is a territorial representation of the reality that you want to represent, and the data components in the form of a database or more commonly, calculation sheets. Geographical data are divided in spatial data and attribute data: Spatial data are recorded as points, lines and polygons (vectorial structure. In other words, the survey systems have been projected to acquire information in accordance to elementary cells corresponding to a territorial grid (raster structure. It also includes remote sensing data.

  13. Geographic variation in Puget Sound tidal channel planform geometry

    Science.gov (United States)

    Hood, W. Gregory

    2015-02-01

    Tidal channels are central elements of salt marsh hydrodynamics, sediment dynamics, and habitat. To develop allometric models predicting the number and size of tidal channels that could develop following salt marsh restoration, channels were digitized from aerial photographs of Puget Sound river delta marshes. Salt marsh area was the independent variable for all dependent channel planform metrics. Tidal channel allometry showed similar scaling exponents for channel planform metrics throughout Puget Sound, simplifying comparisons between locations. Y-intercepts of allometric relationships showed geographic variation, which multiple-regression indicated was associated with tidal range and storm significant wave height. Channel size and complexity were positively related to tidal range and negatively related to wave height. Four case studies, each with paired regions of similar tidal range and contrasting wave environments, further indicated wave environment affected channel geometry. Wave-mediated sediment delivery may be the mechanism involved, with wave-sheltered areas experiencing relative sediment deficits, such that some salt marshes in Puget Sound are already suffering sea-level rise impacts that are reflected in their channel network geometry.

  14. Sizing ocean giants: patterns of intraspecific size variation in marine megafauna

    Directory of Open Access Journals (Sweden)

    Craig R. McClain

    2015-01-01

    Full Text Available What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the world’s oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans.

  15. The political economy of geographical indications

    OpenAIRE

    Deconinck, Koen; Huysmans, Martijn; Swinnen, Johan

    2015-01-01

    In this article we study the political process that governs the creation and size of new Geographical Indications (GIs). Producers can choose to apply for a GI and subsequently go through a bargaining process with the government. We derive the optimal GI area from the point of view of consumers, producers, social welfare, and the government; and we show how bargaining leads to a GI size in between the applicant's optimum and the government's optimum. Under the assumption that the non-GI good ...

  16. Geographical patterns in the beta diversity of China's woody plants

    DEFF Research Database (Denmark)

    Wang, Zhiheng; Fang, Jingyun; Tang, Zhiyao

    2012-01-01

    with their environmental niches due to dispersal limitation induced by China’s topography and/or their low dispersal ability. The projected rapid climatic changes will likely endanger such species. Species dispersal processes should be taken into account in future conservation strategies in China.......Beta diversity (i.e. species turnover rate across space) is fundamental for understanding mechanisms controlling large-scale species richness patterns. However, the influences on beta diversity are still a matter of debate. In particular, the relative role of environmental and spatial processes (e.......g. environmental niche versus dispersal limitation of species) remains elusive, and the influence of species range size has been poorly tested. Here, using distribution maps of 11 405 woody species in China (ca 9.6 ¿ 106 km2), we investigated 1) the geographical and directional patterns of beta diversity for all...

  17. Analyzing geographic clustered response

    Energy Technology Data Exchange (ETDEWEB)

    Merrill, D.W.; Selvin, S.; Mohr, M.S.

    1991-08-01

    In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst's task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm. 21 refs., 15 figs., 2 tabs.

  18. Geographical variation in larval host-plant use by Heliconius erato (Lepidoptera: Nymphalidae and consequences for adult life history

    Directory of Open Access Journals (Sweden)

    D. RODRIGUES

    Full Text Available Adult body size, one of the most important life-history components, varies strongly within and between Heliconius erato phyllis (Lepidoptera: Nymphalidae populations. This study determines if this variation is caused by geographical changes in host-plant used by the larval stage, whose reproductive parameters are influenced by female body size, with estimates of the corresponding heritability. The variation in adult body size was determined together with a survey of passion vine species (Passifloraceae used by the larvae in seven localities in Rio Grande do Sul State: three located in the urban area of Porto Alegre and Triunfo Counties, two within Eucalyptus plantations (Barba Negra Forest, Barra do Ribeiro County, and Águas Belas Experimental Station -- Viamão County, one in a Myrtaceae Forest (Itapuã State Park -- Itapuã County and one in the Atlantic Rain Forest (Maquiné Experimental Station -- Maquiné County. Effects of female body size on fecundity, egg size and egg viability were determined in an outdoor insectary. Size heritability was estimated by rearing in the laboratory offspring of individuals maintained in an insectary. The data showed that adults from populations where larvae feed only upon Passiflora suberosa are smaller than those that feed on Passiflora misera. The larvae prefer P. misera even when the dominant passion vine in a given place is P. suberosa. Fecundity increases linearly with the increase in size of females, but there is no size effect on egg size or viability. Size heritability is null for the adult size range occurring in the field. Thus, the geographical variation of H. erato phyllis adult size is primarily determined by the type, corresponding availability and quality of host-plants used by the larval stage. Within the natural size range of H. erato phyllis, the variation related to this caracter is not genetically based, thus being part of H. erato phyllis phenotypic plasticity.

  19. Geographical variation in larval host-plant use by Heliconius erato (Lepidoptera: Nymphalidae and consequences for adult life history

    Directory of Open Access Journals (Sweden)

    RODRIGUES D.

    2002-01-01

    Full Text Available Adult body size, one of the most important life-history components, varies strongly within and between Heliconius erato phyllis (Lepidoptera: Nymphalidae populations. This study determines if this variation is caused by geographical changes in host-plant used by the larval stage, whose reproductive parameters are influenced by female body size, with estimates of the corresponding heritability. The variation in adult body size was determined together with a survey of passion vine species (Passifloraceae used by the larvae in seven localities in Rio Grande do Sul State: three located in the urban area of Porto Alegre and Triunfo Counties, two within Eucalyptus plantations (Barba Negra Forest, Barra do Ribeiro County, and Águas Belas Experimental Station -- Viamão County, one in a Myrtaceae Forest (Itapuã State Park -- Itapuã County and one in the Atlantic Rain Forest (Maquiné Experimental Station -- Maquiné County. Effects of female body size on fecundity, egg size and egg viability were determined in an outdoor insectary. Size heritability was estimated by rearing in the laboratory offspring of individuals maintained in an insectary. The data showed that adults from populations where larvae feed only upon Passiflora suberosa are smaller than those that feed on Passiflora misera. The larvae prefer P. misera even when the dominant passion vine in a given place is P. suberosa. Fecundity increases linearly with the increase in size of females, but there is no size effect on egg size or viability. Size heritability is null for the adult size range occurring in the field. Thus, the geographical variation of H. erato phyllis adult size is primarily determined by the type, corresponding availability and quality of host-plants used by the larval stage. Within the natural size range of H. erato phyllis, the variation related to this caracter is not genetically based, thus being part of H. erato phyllis phenotypic plasticity.

  20. Widespread generalist clones are associated with range and niche expansion in allopolyploids of Pacific Northwest Hawthorns (Crataegus L.).

    Science.gov (United States)

    Coughlan, J M; Han, S; Stefanović, S; Dickinson, T A

    2017-08-23

    Range and niche expansion are commonly associated with transitions to asexuality, polyploidy and hybridity (allopolyploidy) in plants. The ability of asexual polyploids to colonize novel habitats may be due to widespread generalist clones, multiple ecologically specialized clones, or may be a neutral by-product of multiple, independent origins of asexual polyploids throughout the range. We have quantified niche size and divergence for hawthorns of the Pacific Northwest using data from herbarium vouchers with known cytotypes. We find that all polyploid niches diverge from that of the diploid range, and allopolyploids have the broadest niches. Allotetraploids have the largest niche and the widest geographic distribution. We then assessed the genetic mechanism of range expansion by surveying the ecological and geographic distribution of genotypes within each cytotype from sites in which fine-scale habitat assessments were completed. We find no isolation by either geographic or ecological distance in allopolyploids, suggesting high dispersal and colonization ability. In contrast, autotriploids and diploids show patterns of isolation by geographic distance. We also compared the geographic and ecological distributions of clonal genotypes with those of randomly drawn sites of the most widespread cytotype. We found that most clones are geographically widespread and occur in a variety of habitats. We interpret these findings to suggest that patterns of range and niche expansion in Pacific Northwest Hawthorns may stem from these widespread, ecologically generalist clones of hybrid origin. © 2017 John Wiley & Sons Ltd.

  1. Synthesis and mechanical properties of silicon-doped TiAl-alloys with grain sizes in the submicron range; Herstellung und mechanische Eigenschaften silizidhaltiger TiAl-Werkstoffe mit Korngroessen im Submikronbereich

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    1999-07-01

    The objective of this study is to provide a comprehensive insight into the mechanical properties of nano- and submicron-grained intermetallics, containing ceramic particles as a second phase. The investigations are focussed on {gamma}-TiAl-based alloys with a fine dispersion of titanium silicides. The samples are prepared by high energy milling and subsequent hot isostatic pressing. The mechanical properties are mainly dominated by the grain size as the most important structural feature. At room temperature, the grain size dependence of hardness and yield strength can be described by the well-known Hall-Petch relationship. Contrary to the behavior of conventional alloys, the ductility of submicron-grained alloys drops if the grain size is further reduced. This may be attributed to the insignificance of diffusional creep at room temperature and to arising difficulties evolving for dislocation-based deformation mechanisms. In the high temperature range, the flow stress is strongly reduced. Superplastic deformation becomes feasible already at 800 C. The silicide particles impede grain growth, but they also promote cavitation during tensile straining. The mechanisms of deformation are similar to those established for coarse-grained materials at higher temperatures ({>=}1000 C). (orig.)

  2. GEOGRAPHIC NAMES INFORMATION SYSTEM (GNIS) ...

    Science.gov (United States)

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

  3. Ecological specialization and population size in a biodiversity hotspot: how rare species avoid extinction.

    Science.gov (United States)

    Williams, S E; Williams, Y M; VanDerWal, J; Isaac, J L; Shoo, L P; Johnson, C N

    2009-11-17

    Species with narrow environmental niches typically have small geographic ranges. Small range size is, in turn, often associated with low local abundance. Together, these factors should mean that ecological specialists have very small total populations, putting them at high risk of extinction. But some specialized and geographically restricted species are ancient, and some ecological communities have high proportions of rare and specialized endemics. We studied niche characteristics and patterns of distribution and abundance of terrestrial vertebrates in the rainforests of the Australian Wet Tropics (AWT) to identify mechanisms by which rare species might resist extinction. We show that species with narrow environmental niches and small geographic ranges tend to have high and uniform local abundances. The compensation of geographic rarity by local abundance is exact, such that total population size in the rainforest vertebrates of the AWT is independent of environmental specialization. This effect would tend to help equalize extinction risk for specialists and generalists. Phylogenetic analysis suggests that environmental specialists have been gradually accumulating in this fauna, indicating that small range size/environmental specialization can be a successful trait as long as it is compensated for by demographic commonness. These results provide an explanation of how range-restricted specialists can persist for long periods, so that they now form a major component of high-diversity assemblages such as the AWT.

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

    Science.gov (United States)

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

    2016-07-01

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

  5. Coloring geographical threshold graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Percus, Allon [Los Alamos National Laboratory; Muller, Tobias [EINDHOVEN UNIV. OF TECH

    2008-01-01

    We propose a coloring algorithm for sparse random graphs generated by the geographical threshold graph (GTG) model, a generalization of random geometric graphs (RGG). In a GTG, nodes are distributed in a Euclidean space, and edges are assigned according to a threshold function involving the distance between nodes as well as randomly chosen node weights. The motivation for analyzing this model is that many real networks (e.g., wireless networks, the Internet, etc.) need to be studied by using a 'richer' stochastic model (which in this case includes both a distance between nodes and weights on the nodes). Here, we analyze the GTG coloring algorithm together with the graph's clique number, showing formally that in spite of the differences in structure between GTG and RGG, the asymptotic behavior of the chromatic number is identical: {chi}1n 1n n / 1n n (1 + {omicron}(1)). Finally, we consider the leading corrections to this expression, again using the coloring algorithm and clique number to provide bounds on the chromatic number. We show that the gap between the lower and upper bound is within C 1n n / (1n 1n n){sup 2}, and specify the constant C.

  6. Geographical variation in allometry in the guppy (Poecilia reticulata).

    Science.gov (United States)

    Egset, C K; Bolstad, G H; Rosenqvist, G; Endler, J A; Pélabon, C

    2011-12-01

    Variation in static allometry, the power relationship between character size and body size among individuals at similar developmental stages, remains poorly understood. We tested whether predation or other ecological factors could affect static allometry by comparing the allometry between the caudal fin length and the body length in adult male guppies (Poecilia reticulata) among populations from different geographical areas, exposed to different predation pressures. Neither the allometric slopes nor the allometric elevations (intercept at constant slope) changed with predation pressure. However, populations from the Northern Range in Trinidad showed allometry with similar slopes but lower intercepts than populations from the Caroni and the Oropouche drainages. Because most of these populations are exposed to predation by the prawn Macrobrachium crenulatum, we speculated that the specific selection pressures exerted by this predator generated this change in relative caudal fin size, although effects of other environmental factors could not be ruled out. This study further suggests that the allometric elevation is more variable than the allometric slope.

  7. Reduction of wind power variability through geographic diversity

    CERN Document Server

    Handschy, Mark; Apt, Jay

    2016-01-01

    The variability of wind-generated electricity can be reduced by aggregating the outputs of wind generation plants spread over a large geographic area. In this chapter we utilize Monte Carlo simulations to investigate upper bounds on the degree of achievable smoothing and clarify how the degree of smoothing depends on the number of plants and on the size of the geographic area over which they are spread.

  8. International Refugees: A Geographical Perspective.

    Science.gov (United States)

    Demko, George J.; Wood, William B.

    1987-01-01

    Examines the problem of international refugees from a geographical perspective. Focuses on sub-saharan Africa, Afghanistan, Central America, and southeast Asia. Concludes that geographers can and should use their skills and intellectual tools to address and help resolve this global problem. (JDH)

  9. Adaptive Cartography and Geographical Education

    Science.gov (United States)

    Konecny, Milan; Stanek, Karel

    2010-01-01

    The article focuses on adaptive cartography and its potential for geographical education. After briefly describing the wider context of adaptive cartography, it is suggested that this new cartographic approach establishes new demands and benefits for geographical education, especially in offering the possibility for broader individual…

  10. Photogrammetric measurement of 3D freeform millimetre-sized objects with micro features: an experimental validation of the close-range camera calibration model for narrow angles of view

    Science.gov (United States)

    Percoco, Gianluca; Sánchez Salmerón, Antonio J.

    2015-09-01

    The measurement of millimetre and micro-scale features is performed by high-cost systems based on technologies with narrow working ranges to accurately control the position of the sensors. Photogrammetry would lower the costs of 3D inspection of micro-features and would be applicable to the inspection of non-removable micro parts of large objects too. Unfortunately, the behaviour of photogrammetry is not known when photogrammetry is applied to micro-features. In this paper, the authors address these issues towards the application of digital close-range photogrammetry (DCRP) to the micro-scale, taking into account that in literature there are research papers stating that an angle of view (AOV) around 10° is the lower limit to the application of the traditional pinhole close-range calibration model (CRCM), which is the basis of DCRP. At first a general calibration procedure is introduced, with the aid of an open-source software library, to calibrate narrow AOV cameras with the CRCM. Subsequently the procedure is validated using a reflex camera with a 60 mm macro lens, equipped with extension tubes (20 and 32 mm) achieving magnification of up to 2 times approximately, to verify literature findings with experimental photogrammetric 3D measurements of millimetre-sized objects with micro-features. The limitation experienced by the laser printing technology, used to produce the bi-dimensional pattern on common paper, has been overcome using an accurate pattern manufactured with a photolithographic process. The results of the experimental activity prove that the CRCM is valid for AOVs down to 3.4° and that DCRP results are comparable with the results of existing and more expensive commercial techniques.

  11. Geographical Effects on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    LIN Zhong-Cai; YANG Lei; YANG Kong-Qing

    2005-01-01

    @@ We investigate how the geographical structure of a complex network affects its network topology, synchronization and the average spatial length of edges. The geographical structure means that the connecting probability of two nodes is related to the spatial distance of the two nodes. Our simulation results show that the geographical structure changes the network topology. The synchronization tendency is enhanced and the average spatial length of edges is enlarged when the node can randomly connect to the further one. Analytic results support our understanding of the phenomena.

  12. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  13. 33 CFR 165.8 - Geographic coordinates.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 165.8... Geographic coordinates. Geographic coordinates expressed in terms of latitude or longitude, or both, are not... 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic...

  14. Sexual Dimorphism and Geographic Variation in Dorsal Fin Features of Australian Humpback Dolphins, Sousa sahulensis.

    Science.gov (United States)

    Brown, Alexander M; Bejder, Lars; Parra, Guido J; Cagnazzi, Daniele; Hunt, Tim; Smith, Jennifer L; Allen, Simon J

    2016-01-01

    Determining the sex of free-ranging cetaceans can be challenging. Sexual dimorphism among external features may allow inferences on sex, but such patterns may be difficult to detect and are often confounded by age and geographic variation. Dorsal fin images of 107 female and 54 male Australian humpback dolphins, Sousa sahulensis, from Western Australia (WA) and Queensland (QLD) were used to investigate sex, age and geographic differences in colouration, height/length quotient and number of notches. Adult males exhibited more dorsal fin notches (pdolphins, which could potentially be applied to populations throughout their range. In contrast to adults, presumed immature animals showed little or no loss of pigmentation or spotting; however, the rate of development of these features remains unknown. There were pronounced differences between QLD and WA in the intensity of spotting on dorsal fins and the extent of pigmentation loss around the posterior insertion and trailing edge of the dorsal fin. While based on a limited sample size, these geographic differences may have conservation implications in terms of population subdivision and should be investigated further.

  15. Geographical mobility in Wiltshire, 1754-1914.

    Science.gov (United States)

    Day, Cathy

    2012-01-01

    The aim of this paper is to determine the birthplaces, rather than residences, of spouses married in two parishes in England and to consider the effect of local topography, religion and occupation on pre-marital geographic mobility. A wide array of primary documentary sources was used to construct a database of over 22,000 individuals who lived in south-west Wiltshire in the eighteenth, nineteenth and twentieth centuries. Individuals were arranged in family groups and pedigrees traced for several generations. Data were included on birthplace, religious affiliation, occupation and many other variables. Geographical mobility calculated from birthplace was higher than estimates derived from residence prior to marriage. Brides had shorter marital distances than grooms. There were noticeable changes in the frequency of marital distance at 4 miles and 11 miles. Spouses born outside the parish of marriage were more likely to come from certain villages in ways which cannot be explained merely by distance and size. The Somerset-Wiltshire border formed a barrier, although a porous one, to the flow of marriage partners. Occupation influenced geographical mobility: grooms from higher-status occupational groups were more likely to be born further away than grooms from lower-status occupational groups. Catholic grooms were more likely to be born in the parish of marriage than Protestant grooms, but were also more likely to be born more than 11 miles away.

  16. NEPR Geographic Zone Map 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This geographic zone map was created by interpreting satellite and aerial imagery, seafloor topography (bathymetry model), and the new NEPR Benthic Habitat Map...

  17. Ecoscapes: Geographical Patternings of Relations

    Directory of Open Access Journals (Sweden)

    Aimar Ventsel

    2012-06-01

    Full Text Available Book review of the publication Ecoscapes: Geographical Patternings of Relations. Edited by Gary Backhaus and John Murungi. Lanham, Boulder, New York, Toronto, Oxford, Lexington Books, 2006, xxxiii+241 pp.

  18. Geographic Tongue in Monozygotic Twins

    OpenAIRE

    Shekhar M, Guna

    2014-01-01

    This article discusses a case of 5-year-old girl monozygotic twins who were suffering from geographic tongue (GT), a benign inflammatory disorder of the tongue which is characterized by circinate, irregular erythematous lesions on the dorsum and lateral borders of the tongue caused by loss of filiform papillae of the tongue epithelium. Whilst geographic tongue is a common entity, reports on this condition are uncommon in the literature. To best of our knowledge, this is the first report which...

  19. Geographic latitude and prevalence of adolescent idiopathic scoliosis.

    Science.gov (United States)

    Grivas, Theodoros B; Vasiliadis, Elias; Savvidou, Olga; Mouzakis, Vasilios; Koufopoulos, Georgios

    2006-01-01

    Adolescent Idiopathic Scoliosis (AIS) prevalence has been reported to be different in various geographic latitudes and demonstrates higher values in northern countries. A study on epidemiological reports from the literature was conducted to record the prevalence of AIS among the general population of boys and girls, aged 10-16 years old, in different geographic latitudes, in order to test the hypothesis that the prevalence of AIS among boys and girls is different in various geographic latitudes and to examine if there is a possible association between them. Seventeen peer-reviewed published papers reporting AIS prevalence in the general population of boys and girls from most geographic areas of the northern hemisphere were retrieved from the literature. The geographic latitude of each centre where a particular study was originated was documented. The statistical analysis included a linear regression forward modeling procedure of the AIS prevalence by latitude, weighted by sample size. According to the modelling of the data, a significant positive association between prevalence of AIS and latitude was found for girls (p<0.001), following a rather curvilinear trend, but not a significant positive association was found for boys (p<0.111). A positive association between prevalence of AIS and geographic latitude is reported only for girls in the present study. Prevalence of AIS in boys is not associated significantly with geographic latitude. This differing significant association implicates the possible role of environmental factors in the pathogenesis of AIS that may act in a different way between boys and girls.

  20. The National Map - geographic names

    Science.gov (United States)

    Yost, Lou; Carswell, William J.

    2009-01-01

    The Geographic Names Information System (GNIS), developed by the U.S. Geological Survey (USGS) in cooperation with the U.S. Board on Geographic Names (BGN), contains information about the official names for places, features, and areas in the 50 States, the District of Columbia, the territories and outlying areas of the United States, including Antarctica. It is the geographic names component of The National Map. The BGN maintains working relationships with State names authorities to cooperate in achieving the standardization of geographic names. The GNIS contains records on more than 2 million geographic names in the United States - from populated places, schools, reservoirs, and parks to streams, valleys, springs, ridges, and every feature type except roads and highways. Entries include information such as the federally-recognized name and variant names and spellings for the feature; former names; the status of the name as determined by the BGN; county or counties in which each named feature is located; geographic coordinates that locate the approximate center of an aerial feature or the mouth and source of a linear feature, such as a stream; name of the cell of the USGS topographic map or maps on which the feature may appear; elevation figures derived from the National Elevation Dataset; bibliographic code for the source of the name; BGN decision dates and historical information are available for some features. Data from the GNIS are used for emergency preparedness, mapmaking, local and regional planning, service delivery routing, marketing, site selection, environmental analysis, genealogical research, and other applications.

  1. Geographic patterns of endemic seed plant genera diversity in China

    OpenAIRE

    Shengbin Chen; Zhiyun Ouyang; Yu Fang; Zhenji Li

    2011-01-01

    Endemism describes the phenomenon that the distribution of individual species/taxa is critically restricted to a specific region. Seed plant genera endemic to China (endemic genera) are those with their main geographic distribution range within the borders of China. The geographic patterns of endemic genera can not only guide conservation planning, but these organisms are also important biological resources. We gath-ered data of 173 localities on environmental and spatial factors, and regiona...

  2. Home range and travels

    Science.gov (United States)

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  3. Mapping plant species ranges in the Hawaiian Islands: developing a methodology and associated GIS layers

    Science.gov (United States)

    Price, Jonathan P.; Jacobi, James D.; Gon, Samuel M.; Matsuwaki, Dwight; Mehrhoff, Loyal; Wagner, Warren; Lucas, Matthew; Rowe, Barbara

    2012-01-01

    This report documents a methodology for projecting the geographic ranges of plant species in the Hawaiian Islands. The methodology consists primarily of the creation of several geographic information system (GIS) data layers depicting attributes related to the geographic ranges of plant species. The most important spatial-data layer generated here is an objectively defined classification of climate as it pertains to the distribution of plant species. By examining previous zonal-vegetation classifications in light of spatially detailed climate data, broad zones of climate relevant to contemporary concepts of vegetation in the Hawaiian Islands can be explicitly defined. Other spatial-data layers presented here include the following: substrate age, as large areas of the island of Hawai'i, in particular, are covered by very young lava flows inimical to the growth of many plant species; biogeographic regions of the larger islands that are composites of multiple volcanoes, as many of their species are restricted to a given topographically isolated mountain or a specified group of them; and human impact, which can reduce the range of many species relative to where they formerly were found. Other factors influencing the geographic ranges of species that are discussed here but not developed further, owing to limitations in rendering them spatially, include topography, soils, and disturbance. A method is described for analyzing these layers in a GIS, in conjunction with a database of species distributions, to project the ranges of plant species, which include both the potential range prior to human disturbance and the projected present range. Examples of range maps for several species are given as case studies that demonstrate different spatial characteristics of range. Several potential applications of species-range maps are discussed, including facilitating field surveys, informing restoration efforts, studying range size and rarity, studying biodiversity, managing

  4. VT E911 road address range geocoder

    Data.gov (United States)

    Vermont Center for Geographic Information — VT E911 road address range geocoder. VCGI, in collaboration with the VT E911 Board, has created a suite of geocoding services that can be used to batch geocode...

  5. Range Extent for southern sea otters 2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS shapefile "Range extent of southern sea otters 2016" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris...

  6. Killing Range

    OpenAIRE

    Asal, Victor; Gill, Paul; Rethemeyer, R. Karl; Horgan, John

    2015-01-01

    This paper presents an analysis of the Provisional Irish Republican Army's (PIRA) brigade level behavior during the Northern Ireland Conflict (1970-1998) and identifies the organizational factors that impact a brigade's lethality as measured via terrorist attacks. Key independent variables include levels of technical expertise, cadre age, counter-terrorism policies experienced, brigade size, and IED components and delivery methods. We find that technical expertise within a brigade allows for ...

  7. Thermal sensitivity of cold climate lizards and the importance of distributional ranges.

    Science.gov (United States)

    Bonino, Marcelo F; Moreno Azócar, Débora L; Schulte, James A; Abdala, Cristian S; Cruz, Félix B

    2015-08-01

    One of the fundamental goals in macroecology is to understand the relationship among species' geographic ranges, ecophysiology, and climate; however, the mechanisms underlying the distributional geographic patterns observed remain unknown for most organisms. In the case of ectotherms this is particularly important because the knowledge of these interactions may provide a robust framework for predicting the potential consequences of climate change in these organisms. Here we studied the relationship of thermal sensitivity and thermal tolerance in Patagonian lizards and their geographic ranges, proposing that species with wider distributions have broader plasticity and thermal tolerance. We predicted that lizard thermal physiology is related to the thermal characteristics of the environment. We also explored the presence of trade-offs of some thermal traits and evaluated the potential effects of a predicted scenario of climate change for these species. We examined sixteen species of Liolaemini lizards from Patagonia representing species with different geographic range sizes. We obtained thermal tolerance data and performance curves for each species in laboratory trials. We found evidence supporting the idea that higher physiological plasticity allows species to achieve broader distribution ranges compared to species with restricted distributions. We also found a trade-off between broad levels of plasticity and higher optimum temperatures of performance. Finally, results from contrasting performance curves against the highest environmental temperatures that lizards may face in a future scenario (year 2080) suggest that the activity of species occurring at high latitudes may be unaffected by predicted climatic changes.

  8. 小型宽光谱低分辨率光谱仪器光学设计%Optical Design of a Small-size, Long-spectrum Range and Low-resolution Spectrograph

    Institute of Scientific and Technical Information of China (English)

    吴从均; 颜昌翔

    2011-01-01

    Diffraction grating is the core part of spectrum instruments. To get a good performance of the instruments, different structure should be designed with different type of the grating. A spectrograph, which works in the spectrum range from 340 nm to 800 nm, was designed, whose the resolution is higher than 15nm, and the dispersion size is 28.71 mm on the focal plane. According to comparison of structure of the common spectrographs, the flat field holographic concave grating structure with many advantages was chosen. The long pass filter was used to constrain the secondary spectrum, and the optical source was also considered. As a result, the resolution of the whole system is better than 10 nm, and the size is only 190 mm× 15 mm×60 mm. The flat concave-grating can be got from the market, which greatly decreases the cost of the product. Besides, only a grating can act as the spectrometer system, which can make the system easily assembly and very convenient for mass production.%光栅作为小型光谱仪器分光系统的核心,采用不同种类的光栅制作分光仪器时其结构形式也不尽相同.文中为设计一个工作波段在340-800 nm,分辨率优于15nm,谱面长度28.71 mm的比色仪光学系统,通过对比常见光谱仪结构的优缺点,选择平场凹面光栅作为最终的结构形式,采用长波通滤光片实现对二级光谱重叠的消除,并对比色仪光源系统进行设计,平场凹面光栅光学系统分辨率优于10nm,全系统大小约为190 mm×15 mm×60 mm的光学装置,平场凹面光栅采用市场现有的光栅.不仅满足设计要求,而且元件较少,有利于装调和批量化生产.

  9. Changes at the National Geographic Society

    Science.gov (United States)

    Schwille, Kathleen

    2016-01-01

    For more than 125 years, National Geographic has explored the planet, unlocking its secrets and sharing them with the world. For almost thirty of those years, National Geographic has been committed to K-12 educators and geographic education through its Network of Alliances. As National Geographic begins a new chapter, they remain committed to the…

  10. Changes at the National Geographic Society

    Science.gov (United States)

    Schwille, Kathleen

    2016-01-01

    For more than 125 years, National Geographic has explored the planet, unlocking its secrets and sharing them with the world. For almost thirty of those years, National Geographic has been committed to K-12 educators and geographic education through its Network of Alliances. As National Geographic begins a new chapter, they remain committed to the…

  11. Range Tracing

    OpenAIRE

    Jenke, Philipp; Huhle, Benjamin

    2010-01-01

    In this report, we tackle the problem of merging an arbitrary number of range scans (depth images) into a single surface mesh. The mesh-based representation is superior to point-based approaches since it contains important connectivity information. Most previous mesh-based merge methods, however, lose surface details by using simplifying intermediate surface representations (e.g.\\ implicit functions). Such details are essential for further processing steps, especially for feature-preserving r...

  12. Geolinde - a geographical online learning platform

    Science.gov (United States)

    Steinmüller, Max

    2017-04-01

    Starting about ten years ago during a classroom project on Africa, two colleagues and me started developing an educational platform with geographic content: www.geolinde.musin.de The basic concept was to collect and present a wide range of free educational materials, which could be used by teachers, students and anyone who is interested in geography as well. Soon we found out that producing units for our students also means working on age-appropriate texts on each topic. We made our learning units matching the curriculum for Bavarian 'Gymnasium' and are still working on the improvement of each single unit, especially on the basis of suggestions by our students and our teaching experience. The main advantage in teaching with units from geolinde is that the students work at their own speed, repeat topics, use the glossary or have a look at the skill pages. Everyone uses the wide range of materials in his own way to achieve the curricular goals. Many topics contain short online tests, so that the students can control their basic understanding. The teacher is set free for giving helpful advice, discussing special questions and to monitor the learning progress. After a certain time a question and answer session follows and puts the focus on major curricular goals. Until now www.geolinde.musin.de consists of several blended learning units: Africa, Europe, Climate, Climate Change, Plate tectonics,… It also contains thematic pages on many geographical skills, a glossary of more than one thousand geographic terms and last but not least a collection of approximately 23.000 photos of places of interest all around the world. All the many thousand web pages can be used freely (CC-BY-SA 4.0). The only limitation is www.geolinde.musin.de is available in German only.

  13. Geographic structure of adelie penguin populations: overlap in colony-specific foraging areas

    Science.gov (United States)

    Ainley, D.G.; Ribic, C.A.; Ballard, G.; Heath, S.; Gaffney, I.; Karl, B.J.; Barton, K.J.; Wilson, P.R.; Webb, S.

    2004-01-01

    In an investigation of the factors leading to geographic structuring among Ade??lie Penguin (Pygoscelis adeliae) populations, we studied the size and overlap of colony-specific foraging areas within an isolated cluster of colonies. The study area, in the southwestern Ross Sea, included one large and three smaller colonies, ranging in size from 3900 to 135000 nesting pairs, clustered on Ross and Beaufort Islands. We used triangulation of radio signals from transmitters attached to breeding penguins to determine foraging locations and to define colony-specific foraging areas during the chick-provisioning period of four breeding seasons, 1997-2000. Colony populations (nesting pairs) were determined using aerial photography just after egg-laying; reproductive success was estimated by comparing ground counts of chicks fledged to the number of breeding pairs apparent in aerial photos. Foraging-trip duration, meal size, and adult body mass were estimated using RFID (radio frequency identification) tags and an automated reader and weighbridge. Chick growth was assessed by weekly weighing. We related the following variables to colony size: foraging distance, area, and duration; reproductive success; chick meal size and growth rate; and seasonal variation in adult body mass. We found that penguins foraged closest to their respective colonies, particularly at the smaller colonies. However, as the season progressed, foraging distance, duration, and area increased noticeably, especially at the largest colony. The foraging areas of the smaller colonies overlapped broadly, but very little foraging area overlap existed between the large colony and the smaller colonies, even though the foraging area of the large colony was well within range of the smaller colonies. Instead, the foraging areas of the smaller colonies shifted as that of the large colony grew. Colony size was not related to chick meal size, chick growth, or parental body mass. This differed from the year previous to

  14. The Andes: A Geographical Portrait

    Directory of Open Access Journals (Sweden)

    Anthony Bebbington

    2016-05-01

    Full Text Available Reviewed: The Andes: A Geographical Portrait. By Axel Borsdorf and Christoph Stadel. Translated by Brigitte Scott and Christoph Stadel. Cham, Switzerland: Springer International Publishing, 2015. xiv + 368 pp. US$ 139.00. Also available as an e-book. ISBN 978-3-319-03529-1.

  15. Geographic Projection of Cluster Composites

    NARCIS (Netherlands)

    Nerbonne, J.; Bosveld-de Smet, L.M.; Kleiweg, P.; Blackwell, A.; Marriott, K.; Shimojima, A.

    2004-01-01

    A composite cluster map displays a fuzzy categorisation of geographic areas. It combines information from several sources to provide a visualisation of the significance of cluster borders. The basic technique renders the chance that two neighbouring locations are members of different clusters as the

  16. Geographical Concepts in Turkish Lullabys

    Science.gov (United States)

    Çifçi, Taner

    2016-01-01

    In this study, a collection of lullabies which have an important place in Turkish culture and which form an important genre in folk literature are examined to find out distribution and presentation of geographical terms in the lullabies in this collection. In the study, 2480 lullabies in Turkish Lullabies which is one of the leading collections in…

  17. Territorial Decentration and Geographic Learning.

    Science.gov (United States)

    Stoltman, Joseph P.

    Territorial decentration is a question of major significance to geographic educators. This paper reports the findings of a research project designed to determine the territorial decentration of an American sample of children. The primary purpose of the research was to determine if Piaget's territorial decentration stages are appropriate for…

  18. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands, January 1998 - May 2004 (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  19. Tanzanian food origins and protected geographical indications

    DEFF Research Database (Denmark)

    John, Innocensia Festo; Egelyng, Henrik; Lokina, Azack

    2016-01-01

    As the world's population is constantly growing, food security will remain on the policy Agenda, particularly in Africa. At the same time, global food systems experience a new wave focusing on local foods and food sovereignty featuring high quality food products of verifiable geographical origin...... and sovereignty and quality within an efficient marketing system with the availability of government support, hence the need to identify key candidates for GI certification. Five Tanzanian origin products were selected from 14 candidate agricultural products through a scoping study. Rice from Kyela, Aloe vera...... area, product quality perceived by the consumer in terms of taste, flavour, texture, aroma, appearance (colour, size) and perceptions of links between geography related factors (soil, land weather characteristics) and product qualities. A qualitative case study analysis was done for each of the (five...

  20. Annotation Bibliography for Geographical Science Field

    Directory of Open Access Journals (Sweden)

    Sukendra Martha

    2014-12-01

    Full Text Available This annotated bibliography is gathered specially for the field of geography obtained from various scientific articles (basic concept in geography of different geographical journals. This article aims to present information particulary for geographers who will undertake researches, and indeed need the geographical References with all spatial concepts. Other reason defeated by the rapid development of the branch of technical geography such as geographical information systems (GIS and remote sensing. It hopes that this bibliography can contribute of remotivating geographers to learn and review their original geographical thought.

  1. IL FENOMENO VOLUNTEERED GEOGRAPHIC INFORMATION

    Directory of Open Access Journals (Sweden)

    Flavio Lupia

    2014-12-01

    Full Text Available The contribution addresses the phenomenon of Voluntereed Geographic Informationexplaining these new and burgeoning sources of information offers multidisciplinary scientists an unprecedented opportunity to conduct research on a variety of topics at multiple spatial and temporal scales. In particular the contribution refers to two COST Actions which have been recently activated on the subject which areparticularly relevant for the growing of the European scientific community.

  2. Geographic Luck and Dependency Theory

    Institute of Scientific and Technical Information of China (English)

    Ziheng Liu

    2015-01-01

    Economic disparity is a huge global issue nowadays which threatens the economic justice and thus in some sense decides the fate of human be-ing,especially those from developing countries.This essay analyzes economic disparity by using Geographic Luck and Dependency Theory.None of the two theories could explain the economic disparity individually.China,Britain and Iran are used as three examples to support the thesis.

  3. Geographic Information System Data Analysis

    Science.gov (United States)

    Billings, Chad; Casad, Christopher; Floriano, Luis G.; Hill, Tracie; Johnson, Rashida K.; Locklear, J. Mark; Penn, Stephen; Rhoulac, Tori; Shay, Adam H.; Taylor, Antone; hide

    1995-01-01

    Data was collected in order to further NASA Langley Research Center's Geographic Information System(GIS). Information on LaRC's communication, electrical, and facility configurations was collected. Existing data was corrected through verification, resulting in more accurate databases. In addition, Global Positioning System(GPS) points were used in order to accurately impose buildings on digitized images. Overall, this project will help the Imaging and CADD Technology Team (ICTT) prove GIS to be a valuable resource for LaRC.

  4. Rhizosphere size

    Science.gov (United States)

    Kuzyakov, Yakov; Razavi, Bahar

    2017-04-01

    Estimation of the soil volume affected by roots - the rhizosphere - is crucial to assess the effects of plants on properties and processes in soils and dynamics of nutrients, water, microorganisms and soil organic matter. The challenges to assess the rhizosphere size are: 1) the continuum of properties between the root surface and root-free soil, 2) differences in the distributions of various properties (carbon, microorganisms and their activities, various nutrients, enzymes, etc.) along and across the roots, 3) temporal changes of properties and processes. Thus, to describe the rhizosphere size and root effects, a holistic approach is necessary. We collected literature and own data on the rhizosphere gradients of a broad range of physico-chemical and biological properties: pH, CO2, oxygen, redox potential, water uptake, various nutrients (C, N, P, K, Ca, Mg, Mn and Fe), organic compounds (glucose, carboxylic acids, amino acids), activities of enzymes of C, N, P and S cycles. The collected data were obtained based on the destructive approaches (thin layer slicing), rhizotron studies and in situ visualization techniques: optodes, zymography, sensitive gels, 14C and neutron imaging. The root effects were pronounced from less than 0.5 mm (nutrients with slow diffusion) up to more than 50 mm (for gases). However, the most common effects were between 1 - 10 mm. Sharp gradients (e.g. for P, carboxylic acids, enzyme activities) allowed to calculate clear rhizosphere boundaries and so, the soil volume affected by roots. The first analyses were done to assess the effects of soil texture and moisture as well as root system and age on these gradients. The most properties can be described by two curve types: exponential saturation and S curve, each with increasing and decreasing concentration profiles from the root surface. The gradient based distribution functions were calculated and used to extrapolate on the whole soil depending on the root density and rooting intensity. We

  5. Geographic differences and sexual dimorphism in Greta cubana (Lepidoptera: Nymphalidae

    Directory of Open Access Journals (Sweden)

    Liz Marrero

    2013-09-01

    Full Text Available Greta cubana (Lepidoptera: Nymphalidae presents populations in central and Eastern mountainous regions of Cuba, which are stables habitats that have been isolated for a long period of time. This study evaluates the geographic variation and the sexual dimorphism of this species using geometric morphometric tools,with 91 individuals of four populations: Topes de Collantes (n=5, Pico Turquino (n=26, Loma del Gato (n=27 and Gran Piedra (n=33. For each specimen was calculated its centroid size, wing´s total area and white spots´s relative areas. These variables were compared between sex and populations using Mann-Whitney´s U and Kruskal-Wallis tests, respectively. Discriminant and relative warps analyses were applied to weight matrices to separate between sex and populations. There were not significant differences between males and females wing size, but we found differences in spots size. The analyses applied to weight matrices separated males and females successfully. When analysing geographic variation of forewing area, only significant differences among females from Topes de Collantes and Pico Turquino populations were found. Centroid size and white spots didn’t have significant difference between populations. Both males and females show differences in shape wings between populations. We found clear evidences of sexual dimorphism, nevertheless not geographic differences exist. We are still supporting G. cubana as a monotypic species.

  6. The Influence of Geographic Culture on Language Generation and Literature Appreciation

    Institute of Scientific and Technical Information of China (English)

    周先军

    2014-01-01

    The scope of culture is extremely wide-ranging, which is not measurable. A lot of study has been made on the relationship between language and culture. There is a view that language is part of culture. The two are inseparable. But people seldom study language from the perspective of geographic culture. Geographic culture is also a part of culture, which imposes great influence on language. This thesis explains the influence of geographic culture on language generation and literature appreciation.

  7. Geographic Names Information System (GNIS) Admin Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  8. Geographic Names Information System (GNIS) Antarctica Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  9. Geographic Names Information System (GNIS) Hydrography Points

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  10. Geographic Names Information System (GNIS) Hydrography Lines

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  11. Geographic Names Information System (GNIS) Community Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  12. Geographic Place Names, Published in unknown, SWGRC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geographic Place Names dataset as of unknown. Data by this publisher are often provided in Geographic coordinate system; in a Not Sure projection; The extent...

  13. Geographic Names Information System (GNIS) Landform Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  14. Geographic Names Information System (GNIS) Historical Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  15. Geographic Names Information System (GNIS) Transportation Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  16. Geographic Names Information System (GNIS) Cultural Features

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  17. Geographic Names Information System (GNIS) Structures

    Data.gov (United States)

    Department of Homeland Security — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  18. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    is a small number, but only gave heuristic arguments for this. In this paper, we provide the first methods for rigorously estimating the Range of Skill of a given game. We provide some general, asymptotic bounds that imply that the Range of Skill of a perfectly balanced game tree is almost exponential in its...... size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  19. How a Geographer Looks at Globalism.

    Science.gov (United States)

    Natoli, Salvatore J.

    1990-01-01

    Argues a global perspective is inherent to all geographic research and education. Quotes several influential geographers concerning their views on globalism and geography as a discipline. Examines geography's five fundamental themes and their applicability to a global perspective. Considers roles geographers can play in solving world environmental…

  20. Relevance Measures Using Geographic Scopes and Types

    NARCIS (Netherlands)

    Andogah, Geoffrey; Bouma, Gosse; Peters, C; Jikoun,; Mandl, T; Muller, H; Oard, DW; Penas, A; Petras,; Santos, D

    2008-01-01

    This paper proposes two kinds of relevance measures to rank documents by geographic restriction: scope-based and type-based. The non-geographic and geographic relevance scores are combined using a weighted harmonic mean. The proposed relevance measures and weighting schemes are evaluated on GeoCLEF

  1. 33 CFR 166.103 - Geographic coordinates.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 166.103...) PORTS AND WATERWAYS SAFETY SHIPPING SAFETY FAIRWAYS General § 166.103 Geographic coordinates. Geographic coordinates expressed in terms of latitude or longitude, or both, are not intended for plotting on maps...

  2. 33 CFR 167.3 - Geographic coordinates.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 167.3...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.3 Geographic coordinates. Geographic coordinates are defined using North American 1927 Datum (NAD 27) unless indicated otherwise....

  3. Pore size distribution mapping

    OpenAIRE

    Strange, John H.; J. Beau W. WEBBER; Schmidt, S.D.

    1996-01-01

    Pore size distribution mapping has been demonstrated using NMR cryoporometry\\ud in the presence of a magnetic field gradient, This novel method is extendable to 2D and 3D mapping. It offers a unique nondestructive method of obtaining full pore-size distributions in the range 3 to 100 nm at any point within a bulk sample. \\ud

  4. Subcellular Size

    Science.gov (United States)

    Marshall, Wallace F.

    2015-01-01

    All of the same conceptual questions about size in organisms apply equally at the level of single cells. What determines the size, not only of the whole cell, but of all of its parts? What ensures that subcellular components are properly proportioned relative to the whole cell? How does alteration in organelle size affect biochemical function? Answering such fundamental questions requires us to understand how the size of individual organelles and other cellular structures is determined. Knowledge of organelle biogenesis and dynamics has advanced rapidly in recent years. Does this knowledge give us enough information to formulate reasonable models for organelle size control, or are we still missing something? PMID:25957302

  5. ORANGE: RANGE OF BENEFITS

    OpenAIRE

    Parle Milind; Chaturvedi Dev

    2012-01-01

    No wonder that oranges are one of the most popular fruits in the world. Orange (citrus sinensis) is well known for its nutritional and medicinal properties throughout the world. From times immemorial, whole Orange plant including ripe and unripe fruits, juice, orange peels, leaves and flowers are used as a traditional medicine. Citrus sinensis belongs to the family Rutaceae. The fruit is a fleshy, indehiscent, berry that ranges widely in size from 4 cm to 12 cm. The major medicinal proper...

  6. Network sensitivity to geographical configuration

    CERN Document Server

    Searle, A C; McClelland, D E; Searle, Antony C; Scott, Susan M; Clelland, David E Mc

    2002-01-01

    Gravitational wave astronomy will require the coordinated analysis of data from the global network of gravitational wave observatories. Questions of how to optimally configure the global network naturally arise in this context. We propose a formalism to compare different configurations of the network, using both the coincident network analysis method and the coherent network analysis method, and construct a model to compute a figure-of-merit based on the detection rate for a population of standard-candle binary inspirals. We find that this measure of network quality is very sensitive to the geographic location of component detectors under a coincident network analysis, but comparatively insensitive under a coherent network analysis.

  7. Quenched effective population size

    CERN Document Server

    Sagitov, Serik; Vatutin, Vladimir

    2010-01-01

    We study the genealogy of a geographically - or otherwise - structured version of the Wright-Fisher population model with fast migration. The new feature is that migration probabilities may change in a random fashion. Applying Takahashi's results on Markov chains with random transition matrices, we establish convergence to the Kingman coalescent, as the population size goes to infinity. This brings a novel formula for the coalescent effective population size (EPS). We call it a quenched EPS to emphasize the key feature of our model - random environment. The quenched EPS is compared with an annealed (mean-field) EPS which describes the case of constant migration probabilities obtained by averaging the random migration probabilities over possible environments.

  8. Research on Geographical Urban Conditions Monitoring

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    by LUO A1inghai Abstract Geographical national conditions monitoring has become an important task of surveying and geographical information industry, and will make a profound influence on the development of surveying and ge- ographical information. This paper introduced the basic concept of ge- ographical national conditions monitoring, and discussed its main tasks including complete surveying, dynamic monitoring, statistical analysis and regular release, and expounded the main content of geographical urban conditions monitoring including urbanization monitoring, social- economic development monitoring, transportation foundation monitor- ing and natural ecological environment monitoring, and put forwards the framework system of geographical urban conditions monitoring. Key words surveying and mapping ,geographical national conditions, monitoring ( Page:l )

  9. The Geographic Distribution of Human Capital: Measurement of Contributing Mechanisms

    OpenAIRE

    2010-01-01

    This paper investigates how the geographic distribution of human capital evolves over time. With U.S. data, I decompose generation-to-generation changes in local human capital into three factors: the previous generation’s human capital, intergenerational transmission of skills from parents to their children, and migration of the children. I find evidence of regression to the mean of local skills at the state level and divergence at the commuting zone level. Labor market size, climate, local c...

  10. OUTDOOR EDUCATION AND GEOGRAPHICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    ANDREA GUARAN

    2016-01-01

    Full Text Available This paper focuses on the reflection on the relationship between values and methodological principles of Outdoor Education and spatial and geographical education perspectives, especially in pre-school and primary school, which relates to the age between 3 and 10 years. Outdoor Education is an educational practice that is already rooted in the philosophical thought of the 16th and the 17th centuries, from John Locke to Jean-Jacques Rousseau, and in the pedagogical thought, in particular Friedrich Fröbel, and it has now a quite stable tradition in Northern Europe countries. In Italy, however, there are still few experiences and they usually do not have a systematic and structural modality, but rather a temporarily and experimentally outdoor organization. In the first part, this paper focuses on the reasons that justify a particular attention to educational paths that favour outdoors activities, providing also a definition of outdoor education and highlighting its values. It is also essential to understand that educational programs in open spaces, such as a forest or simply the schoolyard, surely offers the possibility to learn geographical situations. Therefore, the question that arises is how to finalize the best stimulus that the spatial location guarantees for the acquisition of knowledge, skills and abilities about space and geography.

  11. OUTDOOR EDUCATION AND GEOGRAPHICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    ANDREA GUARAN

    2016-01-01

    Full Text Available This paper focuses on the reflection on the relationship between values and methodological principles of Outdoor Education and spatial and geographical education perspectives, especially in pre-school and primary school, which relates to the age between 3 and 10 years. Outdoor Education is an educational practice that is already rooted in the philosophical thought of the 16th and the 17th centuries, from John Locke to Jean-Jacques Rousseau, and in the pedagogical thought, in particular Friedrich Fröbel, and it has now a quite stable tradition in Northern Europe countries. In Italy, however, there are still few experiences and they usually do not have a systematic and structural modality, but rather a temporarily and experimentally outdoor organization. In the first part, this paper focuses on the reasons that justify a particular attention to educational paths that favour outdoors activities, providing also a definition of outdoor education and highlighting its values. It is also essential to understand that educational programs in open spaces, such as a forest or simply the schoolyard, surely offers the possibility to learn geographical situations. Therefore, the question that arises is how to finalize the best stimulus that the spatial location guarantees for the acquisition of knowledge, skills and abilities about space and geography.

  12. Geographic profiling and animal foraging.

    Science.gov (United States)

    Le Comber, Steven C; Nicholls, Barry; Rossmo, D Kim; Racey, Paul A

    2006-05-21

    Geographic profiling was originally developed as a statistical tool for use in criminal cases, particularly those involving serial killers and rapists. It is designed to help police forces prioritize lists of suspects by using the location of crime scenes to identify the areas in which the criminal is most likely to live. Two important concepts are the buffer zone (criminals are less likely to commit crimes in the immediate vicinity of their home) and distance decay (criminals commit fewer crimes as the distance from their home increases). In this study, we show how the techniques of geographic profiling may be applied to animal data, using as an example foraging patterns in two sympatric colonies of pipistrelle bats, Pipistrellus pipistrellus and P. pygmaeus, in the northeast of Scotland. We show that if model variables are fitted to known roost locations, these variables may be used as numerical descriptors of foraging patterns. We go on to show that these variables can be used to differentiate patterns of foraging in these two species.

  13. An efficient and reliable multi-hop geographical broadcast protocol in vehicular ad-hoc networks

    NARCIS (Netherlands)

    Rajendran, R.; Jongh, J. de

    2013-01-01

    In Intelligent Transportation Systems (ITS), disseminating warning messages in a timely and efficient way through wireless short-range communications can save many lives and reduce traffic congestion. A geographical broadcast protocol provides data delivery to specified geographical areas, using mul

  14. On the performance of long-range-corrected density functional theory and reduced-size polarized LPol-n basis sets in computations of electric dipole (hyper)polarizabilities of π-conjugated molecules.

    Science.gov (United States)

    Baranowska-Łączkowska, Angelika; Bartkowiak, Wojciech; Góra, Robert W; Pawłowski, Filip; Zaleśny, Robert

    2013-04-05

    Static longitudinal electric dipole (hyper)polarizabilities are calculated for six medium-sized π-conjugated organic molecules using recently developed LPol-n basis set family to assess their performance. Dunning's correlation-consistent basis sets of triple-ζ quality combined with MP2 method and supported by CCSD(T)/aug-cc-pVDZ results are used to obtain the reference values of analyzed properties. The same reference is used to analyze (hyper)polarizabilities predicted by selected exchange-correlation functionals, particularly those asymptotically corrected.

  15. Dominant predators mediate the impact of habitat size on trophic structure in bromeliad invertebrate communities.

    Science.gov (United States)

    Petermann, Jana S; Farjalla, Vinicius F; Jocque, Merlijn; Kratina, Pavel; MacDonald, A Andrew M; Marino, Nicholas A C; De Omena, Paula M; Piccoli, Gustavo C O; Richardson, Barbara A; Richardson, Michael J; Romero, Gustavo Q; Videla, Martin; Srivastava, Diane S

    2015-02-01

    Local habitat size has been shown to influence colonization and extinction processes of species in patchy environments. However, species differ in body size, mobility, and trophic level, and may not respond in the same way to habitat size. Thus far, we have a limited understanding of how habitat size influences the structure of multitrophic communities and to what extent the effects may be generalizable over a broad geographic range. Here, we used water-filled bromeliads of different sizes as a natural model system to examine the effects of habitat size on the trophic structure of their inhabiting invertebrate communities. We collected composition and biomass data from 651 bromeliad communities from eight sites across Central and South America differing in environmental conditions, species pools, and the presence of large-bodied odonate predators. We found that trophic structure in the communities changed dramatically with changes in habitat (bromeliad) size. Detritivore : resource ratios showed a consistent negative relationship with habitat size across sites. In contrast, changes in predator: detritivore (prey) ratios depended on the presence of odonates as dominant predators in the regional pool. At sites without odonates, predator: detritivore biomass ratios decreased with increasing habitat size. At sites with odonates, we found odonates to be more frequently present in large than in small bromeliads, and predator: detritivore biomass ratios increased with increasing habitat size to the point where some trophic pyramids became inverted. Our results show that the distribution of biomass amongst food-web levels depends strongly on habitat size, largely irrespective of geographic differences in environmental conditions or detritivore species compositions. However, the presence of large-bodied predators in the regional species pool may fundamentally alter this relationship between habitat size and trophic structure. We conclude that taking into account the

  16. The Scaling of Geographic Space from the Perspective of City and Field Blocks and Using Volunteered Geographic Information

    CERN Document Server

    Jiang, Bin

    2012-01-01

    The scaling of geographic space refers to the fact that for a large geographic area its small constituents or units are much more common than the large ones. This paper develops a novel perspective to the scaling of geographic space using large street networks involving both cities and countryside. Given a street network of an entire country, we decompose the street network into individual blocks, each of which forms a minimum ring or cycle such as city blocks and field blocks. The block sizes demonstrate the scaling property, i.e., there are far more small blocks than large ones. Interestingly, and to our surprise, we find that the mean of all the block sizes can easily separate between small and large blocks- a high percentage (e.g., 90%) of smaller ones and a low percentage (e.g., 10%) of larger ones. Based on this regularity, termed as the head/tail division rule, we propose a natural way of delineating city boundaries by grouping the smaller blocks. The extracted city sizes for the three largest European...

  17. The Geographical Dimension of Terrorism

    Science.gov (United States)

    Hawkins, Houston T.

    The events of September 11 ushered us all into a world in which our security and sense of invulnerability were savagely replaced by vulnerability and irrational fear. To the delight of our adversaries who planned these attacks, we often responded in ways that furthered their agenda by weakening the cultural colossus that we call home. Normally terrorism is viewed as intense but localized violence. Seldom is terrorism viewed in its more expansive dimensions. It is burned into our collective memories as a collapsed building, a shattered bus, an incinerated nightclub, or facilities closed by a few anthrax-laced letters. However, terrorism must be studied in dimensions larger than the view from a news camera. This conclusion forms the intellectual basis for The Geographical Dimension of Terrorism.

  18. Network sensitivity to geographical configuration

    Energy Technology Data Exchange (ETDEWEB)

    Searle, Antony C; Scott, Susan M; McClelland, David E [Department of Physics and Theoretical Physics, Faculty of Science, Australian National University, Canberra, ACT 0200 (Australia)

    2002-04-07

    Gravitational wave astronomy will require the coordinated analysis of data from the global network of gravitational wave observatories. Questions of how to optimally configure the global network arise in this context. We have elsewhere proposed a formalism which is employed here to compare different configurations of the network, using both the coincident network analysis method and the coherent network analysis method. We have constructed a network model to compute a figure-of-merit based on the detection rate for a population of standard-candle binary inspirals. We find that this measure of network quality is very sensitive to the geographic location of component detectors under a coincident network analysis, but comparatively insensitive under a coherent network analysis.

  19. Stennis Space Center Environmental Geographic Information System

    Science.gov (United States)

    Lovely, Janette; Cohan, Tyrus

    2000-01-01

    As NASA's lead center for rocket propulsion testing, the John C. Stennis Space Center (SSC) monitors and assesses the off-site impacts of such testing through its Environmental Office (SSC-EO) using acoustical models and ancillary data. The SSC-EO has developed a geographical database, called the SSC Environmental Geographic Information System (SSC-EGIS), that covers an eight-county area bordering the NASA facility. Through the SSC-EGIS, the Enivronmental Office inventories, assesses, and manages the nearly 139,000 acres that comprise Stennis Space Center and its surrounding acoustical buffer zone. The SSC-EGIS contains in-house data as well as a wide range of data obtained from outside sources, including private agencies and local, county, state, and U.S. government agencies. The database comprises cadastral/geodetic, hydrology, infrastructure, geo-political, physical geography, and socio-economic vector and raster layers. The imagery contained in the database is varied, including low-resolution imagery, such as Landsat TM and SPOT; high-resolution imagery, such as IKONOS and AVIRIS; and aerial photographs. The SSC-EGIS has been an integral part of several major projects and the model upon which similar EGIS's will be developed for other NASA facilities. The Corps of Engineers utilized the SSC-EGIS in a plan to establish wetland mitigation sites within the SSC buffer zone. Mississippi State University employed the SSC-EGIS in a preliminary study to evaluate public access points within the buffer zone. The SSC-EO has also expressly used the SSC-EGIS to assess noise pollution modeling, land management/wetland mitigation assessment, environmental hazards mapping, and protected areas mapping for archaeological sites and for threatened and endangered species habitats. The SSC-EO has several active and planned projects that will also make use of the SSC-EGIS during this and the coming fiscal year.

  20. Detection of liver metastases in cancer patients with geographic fatty infiltration of the liver: the added value of contrast-enhanced sonography

    Energy Technology Data Exchange (ETDEWEB)

    Bartolotta, Tommaso Vincenzo; Taibbi, Adele; Picone, Dario; Anastasi, Andrea; Midiri, Massimo; Lagalla, Roberto [Dept. of Radiology-Di.Bi.Med., University of Palermo, Palermo (Italy)

    2017-04-15

    The aim of this study is to assess the role of contrast-enhanced ultrasonography (CEUS) in the detection of liver metastases in cancer patients with geographic liver fatty deposition on greyscale ultrasonography (US). Thirty-seven consecutive cancer patients (24 women and 13 men; age, 33 to 80 years; mean, 58.1 years) with geographic liver fatty deposition, but without any detectable focal liver lesion on greyscale US, underwent sulphur hexafluoride-enhanced US. Two readers reported by consensus the presence, size, and location of any detected lesion. All patients underwent magnetic resonance imaging (MRI) as a confirmatory study. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy were calculated. Seven focal liver lesions (size, 4 to 10 mm; mean, 6.1 mm) were detected in 4/37 patients (10.8%): four metastases (size, 5 to 10 mm; mean, 6.7 mm) were detected both by CEUS and MRI, with one hemangioma and two cysts (size range, 4 to 6 mm; mean, 5.3 mm) detected by MRI only. In 1/37 patients (2.7%), CEUS misdiagnosed geographic fatty change as three metastases. In 32/37 patients (86.5%), no lesions were detected. Sensitivity, specificity, PPV, NPV, and accuracy of CEUS were 100% (95% confidence Interval [CI], 1.000 to 1.000), 97.1% (95% CI, 0.914 to 1.027), 75%, 100%, and 97.3%, respectively. No statistically significant differences were found between CEUS and MRI in the detection of focal liver lesions (P=0.480), whereas both of them performed better than baseline US (P<0.001). CEUS improves the detection of liver metastases in cancer patients with geographic liver fatty deposition on greyscale US.

  1. High proportion of smaller ranged hummingbird species coincides with ecological specialization across the Americas

    Science.gov (United States)

    Martín González, Ana M.; Maruyama, Pietro K.; Sandel, Brody; Vizentin-Bugoni, Jeferson; Schleuning, Matthias; Abrahamczyk, Stefan; Alarcón, Ruben; Araujo, Andréa C.; Araújo, Francielle P.; Mendes de Azevedo, Severino; Baquero, Andrea C.; Cotton, Peter A.; Ingversen, Tanja Toftemark; Kohler, Glauco; Lara, Carlos; Guedes Las-Casas, Flor Maria; Machado, Adriana O.; Machado, Caio Graco; Maglianesi, María Alejandra; Moura, Alan Cerqueira; Nogués-Bravo, David; Oliveira, Genilda M.; Oliveira, Paulo E.; Ornelas, Juan Francisco; Rodrigues, Licléia da Cruz; Rosero-Lasprilla, Liliana; Rui, Ana Maria; Sazima, Marlies; Timmermann, Allan; Varassin, Isabela Galarda; Wang, Zhiheng; Watts, Stella; Fjeldså, Jon; Svenning, Jens-Christian; Rahbek, Carsten; Dalsgaard, Bo

    2016-01-01

    Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographically with a high degree of community-level ecological specialization, but this suggestion remains poorly supported with empirical evidence. Here, we analysed data for hummingbird resource specialization, range size, contemporary climate, and Late Quaternary climate stability for 46 hummingbird–plant mutualistic networks distributed across the Americas, representing 130 hummingbird species (ca 40% of all hummingbird species). We demonstrate a positive relationship between the proportion of SRS of hummingbirds and community-level specialization, i.e. the division of the floral niche among coexisting hummingbird species. This relationship remained strong even when accounting for climate, furthermore, the effect of SRS on specialization was far stronger than the effect of specialization on SRS, suggesting that climate largely influences specialization through species' range-size dynamics. Irrespective of the exact mechanism involved, our results indicate that communities consisting of higher proportions of SRS may be vulnerable to disturbance not only because of their small geographical ranges, but also because of their high degree of specialization. PMID:26842573

  2. Geographical genetics of Pseudoplatystoma punctifer (Castelnau, 1855) (Siluriformes, Pimelodidae) in the Amazon Basin.

    Science.gov (United States)

    Telles, M P C; Collevatti, R G; Braga, R S; Guedes, L B S; Castro, T G; Costa, M C; Silva-Júnior, N J; Barthem, R B; Diniz-Filho, J A F

    2014-05-09

    Geographical genetics allows the evaluation of evolutionary processes underlying genetic variation within and among local populations and forms the basis for establishing more effective strategies for biodiversity conservation at the population level. In this study, we used explicit spatial analyses to investigate molecular genetic variation (estimated using 7 microsatellite markers) of Pseudoplatystoma punctifer, by using samples obtained from 15 localities along the Madeira River and Solimões, Amazon Basin. A high genetic diversity was observed associated with a relatively low FST (0.057; P < 0.001), but pairwise FST values ranged from zero up to 0.21 when some pairs of populations were compared. These FST values have a relatively low correlation with geographic distances (r = 0.343; P = 0.074 by Mantel test), but a Mantel correlogram revealed that close populations (up to 80 km) tended to be more similar than expected by chance (r = 0.360; P = 0.015). The correlogram also showed a exponential-like decrease of genetic similarity with distance, with a patch-size of around 200 km, compatible with isolation-by-distance and analogous processes related to local constraints of dispersal and spatially structured levels of gene flow. The pattern revealed herein has important implications for establishing strategies to maintain genetic diversity in the species, especially considering the threats due to human impacts caused by building large dams in this river system.

  3. Geographic versus industry diversification: constraints matter

    OpenAIRE

    Ehling, Paul; Ramos, Sofia Brito

    2005-01-01

    This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost c...

  4. Effect of Heterogeneity in Initial Geographic Distribution on Opinions’ Competitiveness

    Directory of Open Access Journals (Sweden)

    Alexander S. Balankin

    2015-05-01

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

  5. Portion size

    Science.gov (United States)

    ... Romaine lettuce) One medium baked potato is a computer mouse To control your portion sizes when you ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  6. Kinetic performance comparison of fully and superficially porous particles with sizes ranging between 2.7 lm and 5 lm:Intrinsic evaluation and application to a pharmaceutical test compound

    Institute of Scientific and Technical Information of China (English)

    K. Broeckhoven; D. Cabooter; G. Desmet

    2013-01-01

    The reintroduction of superficially porous particles has resulted in a leap forward for the separation performance in liquid chromatography. The underlying reasons for the higher efficiency of columns packed with these particles are discussed. The performance of the newly introduced 5 mm superficially porous particles is evaluated and compared to 2.7 mm superficially porous and 3.5 and 5 mm fully porous columns using typical test compounds (alkylphenones) and a relevant pharmaceutical compound (impurity of amoxicillin). The 5 mm superficially porous particles provide a superior kinetic performance compared to both the 3.5 and 5 mm fully porous particles over the entire relevant range of separation conditions. The performance of the superficially porous particles, however, appears to depend strongly on retention and analyte properties, emphasizing the importance of comparing different columns under realistic conditions (high enough k) and using the compound of interest.

  7. Genetic evidence of geographical groups among Neanderthals.

    Directory of Open Access Journals (Sweden)

    Virginie Fabre

    Full Text Available The Neanderthals are a well-distinguished Middle Pleistocene population which inhabited a vast geographical area extending from Europe to western Asia and the Middle East. Since the 1950s paleoanthropological studies have suggested variability in this group. Different sub-groups have been identified in western Europe, in southern Europe and in the Middle East. On the other hand, since 1997, research has been published in paleogenetics, carried out on 15 mtDNA sequences from 12 Neanderthals. In this paper we used a new methodology derived from different bioinformatic models based on data from genetics, demography and paleoanthropology. The adequacy of each model was measured by comparisons between simulated results (obtained by BayesianSSC software and those estimated from nucleotide sequences (obtained by DNAsp4 software. The conclusions of this study are consistent with existing paleoanthropological research and show that Neanderthals can be divided into at least three groups: one in western Europe, a second in the Southern area and a third in western Asia. Moreover, it seems from our results that the size of the Neanderthal population was not constant and that some migration occurred among the demes.

  8. The Oklahoma Geographic Information Retrieval System

    Science.gov (United States)

    Blanchard, W. A.

    1982-01-01

    The Oklahoma Geographic Information Retrieval System (OGIRS) is a highly interactive data entry, storage, manipulation, and display software system for use with geographically referenced data. Although originally developed for a project concerned with coal strip mine reclamation, OGIRS is capable of handling any geographically referenced data for a variety of natural resource management applications. A special effort has been made to integrate remotely sensed data into the information system. The timeliness and synoptic coverage of satellite data are particularly useful attributes for inclusion into the geographic information system.

  9. Geographic Distribution of VA Expenditures Report (GDX)

    Data.gov (United States)

    Department of Veterans Affairs — Geographic Distribution of VA Expenditures Report (GDX) located on the Expenditures page in the Expenditure Tables category. This report details VA expenditures at...

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

    Science.gov (United States)

    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

  11. Range expansion by Passer montanus in North America

    Science.gov (United States)

    Burnett, J.L.; Roberts, C.P.; Allen, Craig R.; Brown, M.B.; Moulton, M.P.

    2017-01-01

    Passer montanus became established in a small area of central North America following its introduction in 1870. P. montanus underwent minimal range expansion in the first 100 years following introduction. However, the North American population of P. montanus is now growing in size and expanding in geographic distribution, having expanded approximately 125 km to the north by 1970. We quantify the distance of spread by P. montanus from its introduction site in the greater St. Louis, Missouri-Illinois, USA area, using distributional (presence) data from the National Audubon Society Christmas Bird Count surveys for the period of 1951 to 2014. Linear regressions of the average annual range center of P. montanus confirmed significant shifts to the north at a rate of 3.3 km/year (P < 0.001) km/year. Linear regressions of the linear and angular distance of range center indicates significant northern movement (change in angle of mean range center; P < 0.001) since 1951. Our results quantify the extent of a northward range expansion, and suggesting a probable spread of this species northward.

  12. Geographic Determinants of Chinese Urbanization

    Science.gov (United States)

    Mccord, G. C.; Christensen, P.

    2011-12-01

    In the first years of the 21st century, the human race became primarily urban for the first time in history. With countries like India and China rapidly undergoing structural change from rural agricultural-based economies to urbanized manufacturing- and service-based economies, knowing where the coming waves of urbanization will occur would be of interest for infrastructure planning and for modeling consequences for ecological systems. We employ spatial econometric methods (geographically weighted regression, spatial lag models, and spatial errors models) to estimate two determinants of urbanization in China. The first is the role of physical geography, measured as topography-adjusted distance to major ports and suitability of land for agriculture. The second is the spatial agglomeration effect, which we estimate with a spatial lag model. We find that Chinese urbanization between 1990 and 2000 exhibited important spatial agglomeration effects, as well as significant explanatory power of nearby agricultural suitability and distance to ports, both in a nationwide model and in a model of local regression estimates. These results can help predict the location of new Chinese urbanization, and imply that climate change-induced changes in agricultural potential can affect the spatial distribution of urban areas.

  13. The impact of area deprivation on differences in health: does the choice of the geographical classification matter?

    NARCIS (Netherlands)

    Reijneveld, S.A.; Verheij, R.A.; Bakker, D.H. de

    2000-01-01

    OBJECTIVE Many studies show the average health status in deprived areas to be poorer and the use of health care to be higher, but there is hardly any information on the impact of the geographical classification on the size of these differences. This study examines the impact of the geographical clas

  14. The impact of area deprivation on differences in health: Does the choice of the geographical classification matter?

    NARCIS (Netherlands)

    Reijneveld, S.A.; Verheij, R.A.; Bakker, D.H.de

    2000-01-01

    Objective - Many studies show the average health status in deprived areas to be poorer and the use of health care to be higher, but there is hardly any information on the impact of the geographical classification on the size of these differences. This study examines the impact of the geographical cl

  15. New Mexico Mountain Ranges

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) actively seeks data from and partnerships with Government agencies at all levels and other interested organizations....

  16. Conceptual Model of Dynamic Geographic Environment

    Directory of Open Access Journals (Sweden)

    Martínez-Rosales Miguel Alejandro

    2014-04-01

    Full Text Available In geographic environments, there are many and different types of geographic entities such as automobiles, trees, persons, buildings, storms, hurricanes, etc. These entities can be classified into two groups: geographic objects and geographic phenomena. By its nature, a geographic environment is dynamic, thus, it’s static modeling is not sufficient. Considering the dynamics of geographic environment, a new type of geographic entity called event is introduced. The primary target is a modeling of geographic environment as an event sequence, because in this case the semantic relations are much richer than in the case of static modeling. In this work, the conceptualization of this model is proposed. It is based on the idea to process each entity apart instead of processing the environment as a whole. After that, the so called history of each entity and its spatial relations to other entities are defined to describe the whole environment. The main goal is to model systems at a conceptual level that make use of spatial and temporal information, so that later it can serve as the semantic engine for such systems.

  17. Foreword to Journal of Geographical Sciences

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@In order to strengthen academic exchange of geography between China and other countries,and to offer a publication for exchanging academic ideas of geog-raphers in the world,The Journal of AChinese Geog-raphyis changed to Journal of Geographical Sciences in 2001.

  18. 38 CFR 36.4214 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4214 Section 36.4214 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Preparation General Provisions § 36.4214 Geographical limits. The site for any manufactured home...

  19. 38 CFR 36.4411 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4411 Section 36.4411 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Geographical limits. Any real property purchased, constructed, altered, improved, repaired, or...

  20. 38 CFR 36.4523 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4523 Section 36.4523 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) LOAN GUARANTY Direct Loans § 36.4523 Geographical limits. Any real property purchased, constructed,...

  1. 38 CFR 36.4332 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4332 Section 36.4332 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Geographical limits. Any real property purchased, constructed, altered, improved, or repaired with the...

  2. Ontology-Based Geographic Data Set Integration

    NARCIS (Netherlands)

    Uitermark, Henricus Theodorus Johannes Antonius

    2001-01-01

    Geographic data set integration is particularly important for update propagation, i.e. the reuse of updates from one data set in another data set. In this thesis geographic data set integration (also known as map integration) between two topographic data sets, GBKN and TOP10vector, is described. GBK

  3. 34 CFR 642.33 - Geographic distribution.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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. U.S. Geological Survey Gap Analysis Program Species Ranges

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — GAP species range data show a coarse representation of the total areal extent of a species or the geographic limits within which a species can be found (Morrison...

  6. U.S. Geological Survey Gap Analysis Program Species Ranges

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — GAP species range data show a coarse representation of the total areal extent of a species or the geographic limits within which a species can be found (Morrison and...

  7. Exploring Size.

    Science.gov (United States)

    Brand, Judith, Ed.

    1995-01-01

    "Exploring" is a magazine of science, art, and human perception that communicates ideas museum exhibits cannot demonstrate easily by using experiments and activities for the classroom. This issue concentrates on size, examining it from a variety of viewpoints. The focus allows students to investigate and discuss interconnections among…

  8. Size matter!

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Jespersen, Andreas Maaløe; Skov, Laurits Rhoden

    2015-01-01

    Objectives We examined how a reduction in plate size would affect the amount of food waste from leftovers in a field experiment at a standing lunch for 220 CEOs. Methods A standing lunch for 220 CEOs in the Danish Opera House was arranged to feature two identical buffets with plates of two differ...

  9. Bergmann's rule is maintained during a rapid range expansion in a damselfly.

    Science.gov (United States)

    Hassall, Christopher; Keat, Simon; Thompson, David J; Watts, Phillip C

    2014-02-01

    Climate-induced range shifts result in the movement of a sample of genotypes from source populations to new regions. The phenotypic consequences of those shifts depend upon the sample characteristics of the dispersive genotypes, which may act to either constrain or promote phenotypic divergence, and the degree to which plasticity influences the genotype-environment interaction. We sampled populations of the damselfly Erythromma viridulum from northern Europe to quantify the phenotypic (latitude-body size relationship based on seven morphological traits) and genetic (variation at microsatellite loci) patterns that occur during a range expansion itself. We find a weak spatial genetic structure that is indicative of high gene flow during a rapid range expansion. Despite the potentially homogenizing effect of high gene flow, however, there is extensive phenotypic variation among samples along the invasion route that manifests as a strong, positive correlation between latitude and body size consistent with Bergmann's rule. This positive correlation cannot be explained by variation in the length of larval development (voltinism). While the adaptive significance of latitudinal variation in body size remains obscure, geographical patterns in body size in odonates are apparently underpinned by phenotypic plasticity and this permits a response to one or more environmental correlates of latitude during a range expansion.

  10. Generation of 3D Virtual Geographic Environment Based on Laser Scanning Technique

    Institute of Scientific and Technical Information of China (English)

    DU Jie; CHEN Xiaoyong; FumioYamazaki

    2003-01-01

    This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation ; mathematical-morphology(MM)-based range image filtering,feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computergraphics (CG)-based visualization and animation of geographic virtual reality environment.

  11. Growth and life history variability of the grey reef shark (Carcharhinus amblyrhynchos) across its range

    Science.gov (United States)

    Bradley, Darcy; Conklin, Eric; Papastamatiou, Yannis P.; McCauley, Douglas J.; Pollock, Kydd; Kendall, Bruce E.; Gaines, Steven D.; Caselle, Jennifer E.

    2017-01-01

    For broadly distributed, often overexploited species such as elasmobranchs (sharks and rays), conservation management would benefit from understanding how life history traits change in response to local environmental and ecological factors. However, fishing obfuscates this objective by causing complex and often mixed effects on the life histories of target species. Disentangling the many drivers of life history variability requires knowledge of elasmobranch populations in the absence of fishing, which is rarely available. Here, we describe the growth, maximum size, sex ratios, size at maturity, and offer a direct estimate of survival of an unfished population of grey reef sharks (Carcharhinus amblyrhynchos) using data from an eight year tag-recapture study. We then synthesized published information on the life history of C. amblyrhynchos from across its geographic range, and for the first time, we attempted to disentangle the contribution of fishing from geographic variation in an elasmobranch species. For Palmyra’s unfished C. amblyrhynchos population, the von Bertalanffy growth function (VBGF) growth coefficient k was 0.05 and asymptotic length L∞ was 163.3 cm total length (TL). Maximum size was 175.5 cm TL from a female shark, length at maturity was estimated at 116.7–123.2 cm TL for male sharks, maximum lifespan estimated from VBGF parameters was 18.1 years for both sexes combined, and annual survival was 0.74 year-1. Consistent with findings from studies on other elasmobranch species, we found significant intraspecific variability in reported life history traits of C. amblyrhynchos. However, contrary to what others have reported, we did not find consistent patterns in life history variability as a function of biogeography or fishing. Ultimately, the substantial, but not yet predictable variability in life history traits observed for C. amblyrhynchos across its geographic range suggests that regional management may be necessary to set sustainable harvest

  12. Size matters

    Energy Technology Data Exchange (ETDEWEB)

    Forst, Michael

    2012-11-01

    The shakeout in the solar cell and module industry is in full swing. While the number of companies and production locations shutting down in the Western world is increasing, the capacity expansion in the Far East seems to be unbroken. Size in combination with a good sales network has become the key to success for surviving in the current storm. The trade war with China already looming on the horizon is adding to the uncertainties. (orig.)

  13. Nuclear DNA content in Miscanthus sp. and the geographical variation pattern in Miscanthus lutarioriparius

    Science.gov (United States)

    Sheng, Jiajing; Hu, Xiaohu; Zeng, Xiaofei; Li, Ye; Zhou, Fasong; Hu, Zhongli; Jin, Surong; Diao, Ying

    2016-10-01

    The genome sizes of five Miscanthus species, including 79 accessions of M. lutarioriparius, 8 of M. floridulus, 6 of M. sacchariflorus, 7 of M. sinensis, and 4 of M. × giganteus were examined using flow cytometry. The overall average nuclear DNA content were 4.256 ± 0.6 pg/2C in M. lutarioriparius, 5.175 ± 0.3 pg/2C in M. floridulus, 3.956 ± 0.2 pg/2C in M. sacchariflorus, 5.272 ± 0.2 pg/2C in M. sinensis, and 6.932 ± 0.1 pg/2C in M. × giganteus. Interspecific variation was found at the diploid level, suggesting that DNA content might be a parameter that can be used to differentiate the species. Tetraploid populations were found in M. lutarioriparius, M. sacchariflorus, and M. sinensis, and their DNA content were 8.34 ± 1.2, 8.52, and 8.355 pg, respectively. The association between the DNA content of M. lutarioriparius, collected from representative ranges across the Yangtze River, and its geographic distribution was statistically analyzed. A consistent pattern of DNA content variation in 79 M. lutarioriparius accessions across its entire geographic range was found in this study. Along the Yangtze River, the DNA content of M. lutarioriparius tended to increase from the upstream to the downstream areas, and almost all tetraploids gathered in the upstream area extended to coastal regions.

  14. Strong geographical variation in wing aspect ratio of a damselfly, Calopteryx maculata (Odonata: Zygoptera

    Directory of Open Access Journals (Sweden)

    Christopher Hassall

    2015-08-01

    Full Text Available Geographical patterns in body size have been described across a wide range of species, leading to the development of a series of fundamental biological rules. However, shape variables are less well-described despite having substantial consequences for organism performance. Wing aspect ratio (AR has been proposed as a key shape parameter that determines function in flying animals, with high AR corresponding to longer, thinner wings that promote high manoeuvrability, low speed flight, and low AR corresponding to shorter, broader wings that promote high efficiency long distance flight. From this principle it might be predicted that populations living in cooler areas would exhibit low AR wings to compensate for reduced muscle efficiency at lower temperatures. I test this hypothesis using the riverine damselfly, Calopteryx maculata, sampled from 34 sites across its range margin in North America. Nine hundred and seven male specimens were captured from across the 34 sites (mean = 26.7 ± 2.9 SE per site, dissected and measured to quantify the area and length of all four wings. Geometric morphometrics were employed to investigate geographical variation in wing shape. The majority of variation in wing shape involved changes in wing aspect ratio, confirmed independently by geometric morphometrics and wing measurements. There was a strong negative relationship between wing aspect ratio and the maximum temperature of the warmest month which varies from west-east in North America, creating a positive relationship with longitude. This pattern suggests that higher aspect ratio may be associated with areas in which greater flight efficiency is required: regions of lower temperatures during the flight season. I discuss my findings in light of research of the functional ecology of wing shape across vertebrate and invertebrate taxa.

  15. Geographic Information Systems: A Primer

    Science.gov (United States)

    1990-10-01

    emulsion -based (film) or digital. Information is obtained from a wide range of the electromagnetic spectrum, from ultraviolet to microwave . When... microwave . Imagery is manually or digitally interpreted. For GIS, images can be classified into thematic categories, rendering data into a map or into a...a dedicated project of circumscribed scope. Petroleum companies are interested in oil exploration and thus employ GIS for specific purposes. The

  16. Chromosome Numbers and Genome Size Variation in Indian Species of Curcuma (Zingiberaceae)

    Science.gov (United States)

    Leong-Škorničková, Jana; Šída, Otakar; Jarolímová, Vlasta; Sabu, Mamyil; Fér, Tomáš; Trávníček, Pavel; Suda, Jan

    2007-01-01

    Background and Aims Genome size and chromosome numbers are important cytological characters that significantly influence various organismal traits. However, geographical representation of these data is seriously unbalanced, with tropical and subtropical regions being largely neglected. In the present study, an investigation was made of chromosomal and genome size variation in the majority of Curcuma species from the Indian subcontinent, and an assessment was made of the value of these data for taxonomic purposes. Methods Genome size of 161 homogeneously cultivated plant samples classified into 51 taxonomic entities was determined by propidium iodide flow cytometry. Chromosome numbers were counted in actively growing root tips using conventional rapid squash techniques. Key Results Six different chromosome counts (2n = 22, 42, 63, >70, 77 and 105) were found, the last two representing new generic records. The 2C-values varied from 1·66 pg in C. vamana to 4·76 pg in C. oligantha, representing a 2·87-fold range. Three groups of taxa with significantly different homoploid genome sizes (Cx-values) and distinct geographical distribution were identified. Five species exhibited intraspecific variation in nuclear DNA content, reaching up to 15·1 % in cultivated C. longa. Chromosome counts and genome sizes of three Curcuma-like species (Hitchenia caulina, Kaempferia scaposa and Paracautleya bhatii) corresponded well with typical hexaploid (2n = 6x = 42) Curcuma spp. Conclusions The basic chromosome number in the majority of Indian taxa (belonging to subgenus Curcuma) is x = 7; published counts correspond to 6x, 9x, 11x, 12x and 15x ploidy levels. Only a few species-specific C-values were found, but karyological and/or flow cytometric data may support taxonomic decisions in some species alliances with morphological similarities. Close evolutionary relationships among some cytotypes are suggested based on the similarity in homoploid genome sizes and geographical grouping

  17. Adaptive evolution to novel predators facilitates the evolution of damselfly species range shifts.

    Science.gov (United States)

    Siepielski, Adam M; Beaulieu, Jeremy M

    2017-04-01

    Most species have evolved adaptations to reduce the chances of predation. In many cases, adaptations to coexist with one predator generate tradeoffs in the ability to live with other predators. Consequently, the ability to live with one predator may limit the geographic distributions of species, such that adaptive evolution to coexist with novel predators may facilitate range shifts. In a case study with Enallagma damselflies, we used a comparative phylogenetic approach to test the hypothesis that adaptive evolution to live with a novel predator facilitates range size shifts. Our results suggest that the evolution of Enallagma shifting from living in ancestral lakes with fish as top predators, to living in lakes with dragonflies as predators, may have facilitated an increase in their range sizes. This increased range size likely arose because lakes with dragonflies were widespread, but unavailable as a habitat throughout much of the evolutionary history of Enallagma because they were historically maladapted to coexist with dragonfly predators. Additionally, the traits that have evolved as defenses against dragonflies also likely enhanced damselfly dispersal abilities. While many factors underlie the evolutionary history of species ranges, these results suggest a role for the evolution of predator-prey interactions. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  18. [Equity and geographic distribution of financial resources in health systems].

    Science.gov (United States)

    Porto, Silvia Marta

    2002-01-01

    This study focuses on equity in health and specifically the geographic distribution of financial resources. The author reviews the main contemporary theories of social justice and discusses the concept of equity in general and specifically in the health field. Based on the discussion of selected international experiences (United Kingdom, Spain, and Italy), the Resource Allocation Working Party (RAWP) formula used in the United Kingdom is identified as the most adequate distributive methodology, sizing the relative needs based on the population's demographic and epidemiological profiles. Finally, the results are presented from a simulation performed for the Brazilian case, showing that a more equitable geographic distribution of financial resources would require a redistribution favoring the States of the North and Northeast. The article concludes by highlighting that a comparison of actual fund outlays by the Ministry of Health in 1994 and the results of the simulation with the RAWP methodology for the Brazilian case show that the principles written into Brazilian legislation were absent from the geographic distribution of financial resources.

  19. ORANGE: RANGE OF BENEFITS

    Directory of Open Access Journals (Sweden)

    Parle Milind

    2012-07-01

    Full Text Available No wonder that oranges are one of the most popular fruits in the world. Orange (citrus sinensis is well known for its nutritional and medicinal properties throughout the world. From times immemorial, whole Orange plant including ripe and unripe fruits, juice, orange peels, leaves and flowers are used as a traditional medicine. Citrus sinensis belongs to the family Rutaceae. The fruit is a fleshy, indehiscent, berry that ranges widely in size from 4 cm to 12 cm. The major medicinal properties of orange include anti-bacterial, anti-fungal, anti- diabetic, cardio- protective, anti-cancer, anti-arthritic, anti-inflammatory, anti-oxidant, anti-Tubercular, anti-asthmatic and anti-hypertensive. Phytochemically, whole plant contains limonene, citral, neohesperidin, naringin, rutin, rhamnose, eriocitrin, and vitamin-C. In the present review article, a humble attempt is made to compile all the strange facts available about this tasty fruit.

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

    Science.gov (United States)

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

    2015-09-01

    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.

  1. Breton Island, Louisiana Baseline (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Baseline (Geographic, NAD83) consists of vector line data that were input into the Digital Shoreline Analysis System (DSAS) version 4.0,...

  2. Representations built from a true geographic database

    DEFF Research Database (Denmark)

    Bodum, Lars

    2005-01-01

    the whole world in 3d and with a spatial reference given by geographic coordinates. Built on top of this is a customised viewer, based on the Xith(Java) scenegraph. The viewer reads the objects directly from the database and solves the question about Level-Of-Detail on buildings, orientation in relation...... a representation based on geographic and geospatial principles. The system GRIFINOR, developed at 3DGI, Aalborg University, DK, is capable of creating this object-orientation and furthermore does this on top of a true Geographic database. A true Geographic database can be characterized as a database that can cover...... to terrain and rendering of the model. All this is done in something very close to real-time. GRIFINOR is at the moment working within a limited edition of the world. Only a few classes have been selected for representation in GRIFINOR. These are buildings, cadastre, trees, grass, roads. This paper...

  3. Medicare Geographic Variation - Public Use File

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medicare Geographic Variation Public Use File provides the ability to view demographic, utilization and quality indicators at the state level (including...

  4. Training for Internationalization through Domestic Geographical Dispersion

    DEFF Research Database (Denmark)

    Santangelo, Grazia D.; Stucchi, Tamara

    organizational learning, we seek to solve this puzzle in relation to the internationalization of Indian BGs. In particular, we argue that in heterogeneous domestic emerging markets BG’s geographical dispersion across sub-national states provides training for internationalization. To internationalize successfully......, BGs need to develop the capability of managing geographically dispersed units in institutional heterogeneous contexts. Domestic geographical dispersion would indeed help the BG dealing with different regulations, customers and infrastructures. However, there is less scope for such training as BGs...... become more internationally experienced, and the benefits of domestic geographical dispersions are limited by the degree of urbanization of sub-national states. We test our argument on a sample of 693 Indian BGs over the period 2001-2010....

  5. Breton Island, Louisiana Baseline (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Baseline (Geographic, NAD83) consists of vector line data that were input into the Digital Shoreline Analysis System (DSAS) version 4.0,...

  6. Recommendation Of A National Geographic Framework

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to provide guidance relative to building capacity and geographically focusing efforts to implement landscape scale conservation...

  7. Progress and Prospects of Geographical Research

    Institute of Scientific and Technical Information of China (English)

    Zheng Du

    2001-01-01

    Contemporary geography includes physical geography, human geography and geographical information science. Advanced trends in geographical research are characterized by the following aspects:intersection and infiltration with various disciplines, the strengthening of integrated studies within geography, the deepening of micro-scale studies of geographical processes, the broadening of applied research fields, experimental geography and the introduction of new techniques and the transformation of theoretical concepts. In order to promote the development of earth system science and to coordinate the man-land relationship, geographers may make contributions in aspects such as the process and pattern of the terrestrial surface, global change and its regional response, natural resources security and eco-reconstruction, sustainable regional development, mechanism of the man-land relationship and its coordination, geo-information science and technology, digital earth research.

  8. Identifying Geographic Clusters: A Network Analytic Approach

    CERN Document Server

    Catini, Roberto; Penner, Orion; Riccaboni, Massimo

    2015-01-01

    In recent years there has been a growing interest in the role of networks and clusters in the global economy. Despite being a popular research topic in economics, sociology and urban studies, geographical clustering of human activity has often studied been by means of predetermined geographical units such as administrative divisions and metropolitan areas. This approach is intrinsically time invariant and it does not allow one to differentiate between different activities. Our goal in this paper is to present a new methodology for identifying clusters, that can be applied to different empirical settings. We use a graph approach based on k-shell decomposition to analyze world biomedical research clusters based on PubMed scientific publications. We identify research institutions and locate their activities in geographical clusters. Leading areas of scientific production and their top performing research institutions are consistently identified at different geographic scales.

  9. GNIS: Geographic Names Information Systems - All features

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) actively seeks data from and partnerships with Government agencies at all levels and other interested organizations....

  10. 7 CFR 51.2546 - Size.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Size. 51.2546 Section 51.2546 Agriculture Regulations... Standards for Grades of Pistachio Nuts in the Shell § 51.2546 Size. Nuts may be considered as meeting a size... below the extremes of the range specified. Table IV—Nut Size Size designations Average number of nuts...

  11. 7 CFR 51.3413 - Size.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Size. 51.3413 Section 51.3413 Agriculture Regulations... Standards for Grades of Potatoes for Processing 1 § 51.3413 Size. (a) The minimum size, maximum size or range in size may be specified in connection with the grade in terms of diameter or weight. (b) Diameter...

  12. 7 CFR 51.344 - Size.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Size. 51.344 Section 51.344 Agriculture Regulations of... Standards for Grades of Apples for Processing Size § 51.344 Size. (a) The minimum and maximum sizes or range of sizes shall be determined as agreed upon by buyer and seller. (b) Unless otherwise specified, the...

  13. A procedure to characterize geographic distributions of rare disorders in cohorts

    Directory of Open Access Journals (Sweden)

    Hertz-Picciotto Irva

    2008-05-01

    Full Text Available Abstract Background Individual point data can be analyzed against an entire cohort instead of only sampled controls to accurately picture the geographic distribution of populations at risk for low prevalence diseases. Analyzed as individual points, many smaller clusters with high relative risks (RR and low empirical p values are indistinguishable from a random distribution. When points are aggregated into areal units, small clusters may result in a larger cluster with a low RR or be lost if divided into pieces included in units of larger populations that show no increased prevalence. Previous simulation studies showed lowered validity of spatial scan tests for true clusters with low RR. Using simulations, this study explored the effects of low cluster RR and areal unit size on local area clustering test (LACT results, proposing a procedure to improve accuracy of cohort spatial analysis for rare events. Results Our simulations demonstrated the relationship of true RR to observed RR and p values with various, randomly located, cluster shapes, areal unit sizes and scanning window shapes in a diverse population distribution. Clusters with RR We propose a cluster identification procedure that applies parallel multiple LACTs, one on point data and three on two distinct sets of areal units created with varying population parameters that minimize the range of population sizes among units. By accepting only clusters identified by all LACTs, having a minimum population size, a minimum relative risk and a maximum p value, this procedure improves the specificity achieved by any one of these tests alone on a cohort study of low prevalence data while retaining sensitivity for small clusters. The procedure is demonstrated on two study regions, each with a five-year cohort of births and cases of a rare developmental disorder. Conclusion For truly exploratory research on a rare disorder, false positive clusters can cause costly diverted research efforts. By

  14. Ampliación del ámbito geográfico-altitudinal y uso de hábitats suburbanos por la mascarita pico grueso (Geothlypis poliocephala Geographic-altitudinal range extension and suburban habitat use of the Grey-crowned Yellowthroat (Geothlypis poliocephala

    Directory of Open Access Journals (Sweden)

    Ian MacGregor-Fors

    2008-12-01

    Full Text Available Se presenta el primer registro de la mascarita pico grueso (Geothlypis poliocephala para la región del Eje Neovolcánico Transversal, México. Los sitios donde registramos/capturamos esta especie se encuentran en los suburbios de la ciudad de Morelia, 427 m arriba del ámbito altitudinal descrito para la especie. Esto puede deberse a 2 factores: 1 la urbanización que genera hábitats propicios para la especie en su periferia, y 2 el incremento de la temperatura en la región en la que se encuentra la ciudad de Morelia. Ambos factores facilitan que esta especie de tierras bajas pueda habitar en áreas de mayor altitud. Así, nuestros registros sugieren que la mascarita pico grueso puede catalogarse como especie potencial a utilizar hábitats suburbanos cuando éstos son similares a los hábitats en los que se distribuye de manera natural.The first record of the Grey-crowned Yellowthroat (Geothlypis poliocephala in the Transmexican Volcanic Belt biogeographic region (Mexico, within the Morelia city suburbs is presented. Sites were this parulid was sighted / captured were located 427 m higher than its described altitudinal range. This could be due to 2 factors: 1 urbanization generates suitable habitats for this species in periurban areas, and 2 temperature values have increased in the region where the city of Morelia is located. These factors allow that a lowland bird species can inhabit in more elevated areas. Thus, our records suggest that the Grey-crowned Yellowthroat can be catalogued as potential to use suburban environments when these are similar to those used by the species on its natural distribution area.

  15. Sauropod dinosaurs evolved moderately sized genomes unrelated to body size.

    Science.gov (United States)

    Organ, Chris L; Brusatte, Stephen L; Stein, Koen

    2009-12-22

    Sauropodomorph dinosaurs include the largest land animals to have ever lived, some reaching up to 10 times the mass of an African elephant. Despite their status defining the upper range for body size in land animals, it remains unknown whether sauropodomorphs evolved larger-sized genomes than non-avian theropods, their sister taxon, or whether a relationship exists between genome size and body size in dinosaurs, two questions critical for understanding broad patterns of genome evolution in dinosaurs. Here we report inferences of genome size for 10 sauropodomorph taxa. The estimates are derived from a Bayesian phylogenetic generalized least squares approach that generates posterior distributions of regression models relating genome size to osteocyte lacunae volume in extant tetrapods. We estimate that the average genome size of sauropodomorphs was 2.02 pg (range of species means: 1.77-2.21 pg), a value in the upper range of extant birds (mean = 1.42 pg, range: 0.97-2.16 pg) and near the average for extant non-avian reptiles (mean = 2.24 pg, range: 1.05-5.44 pg). The results suggest that the variation in size and architecture of genomes in extinct dinosaurs was lower than the variation found in mammals. A substantial difference in genome size separates the two major clades within dinosaurs, Ornithischia (large genomes) and Saurischia (moderate to small genomes). We find no relationship between body size and estimated genome size in extinct dinosaurs, which suggests that neutral forces did not dominate the evolution of genome size in this group.

  16. Geographic access to and availability of community resources for persons diagnosed with severe mental illness in Philadelphia, USA.

    Science.gov (United States)

    Metraux, Stephen; Brusilovskiy, Eugene; Prvu-Bettger, Janet A; Irene Wong, Yin-Ling; Salzer, Mark S

    2012-05-01

    This study assesses whether there are differences in geographic access to and availability of a range of different amenities for a large group of persons diagnosed with severe mental illness (SMI) in Philadelphia (USA) when compared to a more general set of residential addresses. The 15,246 persons who comprised the study group had better outcomes than an equal number of geographical points representative of the general Philadelphia population on measures of geographic proximity and availability for resources considered important by people diagnosed with SMI. These findings provide support for the presence of geographic prerequisites for attaining meaningful levels of community integration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Leopard (Panthera pardus status, distribution, and the research efforts across its range

    Directory of Open Access Journals (Sweden)

    Andrew P. Jacobson

    2016-05-01

    Full Text Available The leopard’s (Panthera pardus broad geographic range, remarkable adaptability, and secretive nature have contributed to a misconception that this species might not be severely threatened across its range. We find that not only are several subspecies and regional populations critically endangered but also the overall range loss is greater than the average for terrestrial large carnivores. To assess the leopard’s status, we compile 6,000 records at 2,500 locations from over 1,300 sources on its historic (post 1750 and current distribution. We map the species across Africa and Asia, delineating areas where the species is confirmed present, is possibly present, is possibly extinct or is almost certainly extinct. The leopard now occupies 25–37% of its historic range, but this obscures important differences between subspecies. Of the nine recognized subspecies, three (P. p. pardus, fusca, and saxicolor account for 97% of the leopard’s extant range while another three (P. p. orientalis, nimr, and japonensis have each lost as much as 98% of their historic range. Isolation, small patch sizes, and few remaining patches further threaten the six subspecies that each have less than 100,000 km2 of extant range. Approximately 17% of extant leopard range is protected, although some endangered subspecies have far less. We found that while leopard research was increasing, research effort was primarily on the subspecies with the most remaining range whereas subspecies that are most in need of urgent attention were neglected.

  18. Geographic Names Information System (GNIS) for Lousiana, Geographic NAD83, USGS (2007) [GNIS_LA_USGS_2007

    Data.gov (United States)

    Louisiana Geographic Information Center — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  19. Genomic structure and insertion sites of Helicobacter pylori prophages from various geographical origins

    Science.gov (United States)

    Vale, Filipa F.; Nunes, Alexandra; Oleastro, Mónica; Gomes, João P.; Sampaio, Daniel A.; Rocha, Raquel; Vítor, Jorge M. B.; Engstrand, Lars; Pascoe, Ben; Berthenet, Elvire; Sheppard, Samuel K.; Hitchings, Matthew D.; Mégraud, Francis; Vadivelu, Jamuna; Lehours, Philippe

    2017-01-01

    Helicobacter pylori genetic diversity is known to be influenced by mobile genomic elements. Here we focused on prophages, the least characterized mobile elements of H. pylori. We present the full genomic sequences, insertion sites and phylogenetic analysis of 28 prophages found in H. pylori isolates from patients of distinct disease types, ranging from gastritis to gastric cancer, and geographic origins, covering most continents. The genome sizes of these prophages range from 22.6–33.0 Kbp, consisting of 27–39 open reading frames. A 36.6% GC was found in prophages in contrast to 39% in H. pylori genome. Remarkably a conserved integration site was found in over 50% of the cases. Nearly 40% of the prophages harbored insertion sequences (IS) previously described in H. pylori. Tandem repeats were frequently found in the intergenic region between the prophage at the 3′ end and the bacterial gene. Furthermore, prophage genomes present a robust phylogeographic pattern, revealing four distinct clusters: one African, one Asian and two European prophage populations. Evidence of recombination was detected within the genome of some prophages, resulting in genome mosaics composed by different populations, which may yield additional H. pylori phenotypes. PMID:28205536

  20. Genetic diversity, host range, and distribution of tomato yellow leaf curl virus in Iran.

    Science.gov (United States)

    Shirazi, M; Mozafari, J; Rakhshandehroo, F; Shams-Bakhsh, M

    2014-01-01

    Tomato yellow leaf curl virus (TYLCV) is considered one of the most important tomato pathogens in tropical and subtropical regions including Iran. During the years 2007 to 2009, a total number of 510 symptomatic and asymptomatic vegetable, ornamental and weed samples were collected from fields and greenhouses in ten provinces of Iran. Symptoms included stunting, yellowing, leaf curl and flower senescence. PCR with specific primers showed TYLCV infection in 184 samples (36%) such as cucumber, pepper, tomato and several weeds from seven provinces. Based on the geographical origin, host range and symptoms, twenty three representative isolates were selected for phylogenetic analysis. An amplicon with a size about 608 base pair (bp) comprising partial sequence of the coat (CP) and movement protein (MP) coding regions of the viral genome was sequenced and compared with the corresponding selected sequences available in GenBank for Iran and worldwide. Phylogenetic analyses on the basis of the nucleotide sequences indicated two geographically separated clades. Isolates collected from Hormozgan, Khuzestan and Kerman provinces were grouped together with other Iranian isolates including TYLCV-Ir2, TYLCV-Kahnooj, and an isolate from Oman. It was also revealed that isolates collected from Boushehr, Fars, Tehran, and Isfahan placed close to the Iranian isolate TYLCV-Abadeh and isolates from Israel and Egypt. No correlation was found between the genetic variation and the host species, but selected Iranian isolates were grouped on the basis of the geographical origins. Results of this study indicated a high genetic diversity among Iranian TYLCV isolates.

  1. An intelligent method for geographic Web search

    Science.gov (United States)

    Mei, Kun; Yuan, Ying

    2008-10-01

    While the electronically available information in the World-Wide Web is explosively growing and thus increasing, the difficulty to find relevant information is also increasing for search engine user. In this paper we discuss how to constrain web queries geographically. A number of search queries are associated with geographical locations, either explicitly or implicitly. Accurately and effectively detecting the locations where search queries are truly about has huge potential impact on increasing search relevance, bringing better targeted search results, and improving search user satisfaction. Our approach focus on both in the way geographic information is extracted from the web and, as far as we can tell, in the way it is integrated into query processing. This paper gives an overview of a spatially aware search engine for semantic querying of web document. It also illustrates algorithms for extracting location from web documents and query requests using the location ontologies to encode and reason about formal semantics of geographic web search. Based on a real-world scenario of tourism guide search, the application of our approach shows that the geographic information retrieval can be efficiently supported.

  2. Comparison of immunization strategies in geographical networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Aihara, Kazuyuki [Institute of Industrial Science, The University of Tokyo, Tokyo (Japan)] [ERATO Aihara Complexity Modelling Project, JST, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 (Japan); Kim, Beom Jun, E-mail: beomjun@skku.ed [BK21 Physics Research Division and Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)] [Department of Computational Biology, School of Computer Science and Communication, Royal Institute of Technology, 100 44 Stockholm (Sweden)

    2009-10-12

    The epidemic spread and immunizations in geographically embedded scale-free (SF) and Watts-Strogatz (WS) networks are numerically investigated. We make a realistic assumption that it takes time which we call the detection time, for a vertex to be identified as infected, and implement two different immunization strategies: one is based on connection neighbors (CN) of the infected vertex with the exact information of the network structure utilized and the other is based on spatial neighbors (SN) with only geographical distances taken into account. We find that the decrease of the detection time is crucial for a successful immunization in general. Simulation results show that for both SF networks and WS networks, the SN strategy always performs better than the CN strategy, especially for more heterogeneous SF networks at long detection time. The observation is verified by checking the number of the infected nodes being immunized. We found that in geographical space, the distance preferences in the network construction process and the geographically decaying infection rate are key factors that make the SN immunization strategy outperforms the CN strategy. It indicates that even in the absence of the full knowledge of network connectivity we can still stop the epidemic spread efficiently only by using geographical information as in the SN strategy, which may have potential applications for preventing the real epidemic spread.

  3. Louisiana State Soil Geographic, General Soil Map, Geographic NAD83, NWRC (1998) [statsgo_soils_NWRC_1998

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains vector line map information. The vector data contain selected base categories of geographic features, and characteristics of these features,...

  4. Optical range and range rate estimation for teleoperator systems

    Science.gov (United States)

    Shields, N. L., Jr.; Kirkpatrick, M., III; Malone, T. B.; Huggins, C. T.

    1974-01-01

    Range and range rate are crucial parameters which must be available to the operator during remote controlled orbital docking operations. A method was developed for the estimation of both these parameters using an aided television system. An experiment was performed to determine the human operator's capability to measure displayed image size using a fixed reticle or movable cursor as the television aid. The movable cursor was found to yield mean image size estimation errors on the order of 2.3 per cent of the correct value. This error rate was significantly lower than that for the fixed reticle. Performance using the movable cursor was found to be less sensitive to signal-to-noise ratio variation than was that for the fixed reticle. The mean image size estimation errors for the movable cursor correspond to an error of approximately 2.25 per cent in range suggesting that the system has some merit. Determining the accuracy of range rate estimation using a rate controlled cursor will require further experimentation.

  5. Geographical thinking in nursing inquiry, part one: locations, contents, meanings.

    Science.gov (United States)

    Andrews, Gavin J

    2016-10-01

    Spatial thought is undergoing somewhat of a renaissance in nursing. Building on a long disciplinary tradition of conceptualizing and studying 'nursing environment', the past twenty years has witnessing the establishment and refinement of explicitly geographical nursing research. This article - part one in a series of two - reviews the perspectives taken to date, ranging from historical precedent in classical nursing theory through to positivistic spatial science, political economy, and social constructivism in contemporary inquiry. This discussion sets up part two, which considers the potential of non-representational theory for framing future studies.

  6. Geographical structure and differential natural selection among North European populations

    DEFF Research Database (Denmark)

    McEvoy, Brian P; Montgomery, Grant W; McRae, Allan F

    2009-01-01

    from F(ST)-based analysis of genic and nongenic SNPs that differential positive selection has operated across these populations despite their short divergence time and relatively similar geographic and environmental range. The pressure appears to have been focused on genes involved in immunity, perhaps...... reflecting response to infectious disease epidemic. Such an event may explain a striking selective sweep centered on the rs2508049-G allele, close to the HLA-G gene on chromosome 6. Evidence of the sweep extends over a 8-Mb/3.5-cM region. Overall, the results illustrate the power of dense genotype and sample...

  7. [Estimation of a geographic accessibility index of different health centers in Mexico].

    Science.gov (United States)

    Garza-Elizondo, María Eugenia; Salinas-Martínez, Ana María; Núñez-Rocha, Georgina Mayela; Villarreal Ríos, Enrique; Vásquez-Treviño, María Guadalupe; Vásquez-Salazar, María Guadalupe

    2008-12-01

    The accessibility to health centers is a limitation to the use of preventive and curative health centers. To assess geographic accessibility using a parameter that integrates information about the use of preventive services and travelling time from home to the health center. We analyzed target geographical areas of 10 community centers located at the Northeast of Mexico. A survey was conducted to collect information about the utilization of preventive services for detection of diabetes and hypertension within last year and in women, detection of cervical and breast cancer. The time required to travel between the health center and the farthest location point at every neighborhood of each geographic area, using public or private transportation, was calculated. Health service use and transportation time were condensed in a single parameter, called geographic accessibility index. Data was normalized using z scores. Three geographical areas denominated 7, 8 and 10 had the lowest detection rates of chronic diseases, with values ranging from 45% to 48%. By car, area number 3 had the longest travelling time, corresponding to 14 minutes. The longest travelling times by public transportation were detected in areas 1 and 3, corresponding to 27 and 29 minutes, respectively The geographic accessibility index showed that the least favorable z scores travelling by car corresponded to areas 6 and 10 and, when travelling on public transportation, to areas 8 and 10. The geographic accessibility index identified areas that required improvements in accessibility.

  8. Environmental dependence of thermal reaction norms: host plant quality can reverse the temperature-size rule.

    Science.gov (United States)

    Diamond, Sarah E; Kingsolver, Joel G

    2010-01-01

    The temperature-size rule, a form of phenotypic plasticity in which decreased temperature increases final size, is one of the most widespread patterns in biology, particularly for ectotherms. Identifying the environmental conditions in which this pattern is reversed is key to understanding the generality of the rule. We use wild and domesticated populations of the tobacco hornworm Manduca sexta and the natural host plants of this species to explore the consequences of resource quality for the temperature-size rule. Manduca sexta reared on a high-quality host, tobacco (Nicotiana tabacum), followed the temperature-size rule, with larger final sizes at lower temperatures. In contrast, M. sexta reared on a low-quality host, devil's claw (Proboscidea louisianica), showed the reverse response. Wild and domesticated M. sexta exhibited qualitatively similar responses. Survival, growth and development rates, fecundity, and final size decreased with decreasing temperature in M. sexta reared on devil's claw. We propose that the reversal of the temperature-size rule results from the stressful combination of low temperatures and low dietary quality. Such reversals may impact seasonal and geographic patterns of host use in Manduca and other systems. Our results suggest that the temperature-size rule occurs for a restricted range of nonstressful environmental conditions, limiting the robustness of this widespread pattern of phenotypic plasticity.

  9. A Novel Geographical Information Systems Framework to Characterize Photovoltaic Deployment in the UK: Initial Evidence

    Directory of Open Access Journals (Sweden)

    Paul Westacott

    2016-01-01

    Full Text Available Globally, deployment of grid-connected photovoltaics (PV has increased dramatically in recent years. The UK has seen rapid uptake reaching over 500,000 installations totalling 2.8 GWp by 2013. PV can be installed in different market segments (domestic rooftop, non-domestic rooftop and ground-mounted “solar-farms” covering a broad range of system sizes in a high number of locations. It is important to gain detailed understanding of what grid-connected PV deployment looks like (e.g., how it deployed across different geographic areas and market segments, and identify the major drivers behind it. This paper answers these questions by developing a novel geographical information systems (GIS-framework—the United Kingdom Photovoltaics Database (UKPVD—to analyze temporal and spatial PV deployment trends at high resolution across all market segments. Results show how PV deployment changed over time with the evolution of governmental PV policy support. Then spatial trends as function of local irradiation, rurality (as a proxy of building and population density and building footprint (as a proxy for roof-area are analyzed. We find in all market segments, PV deployment is strongly correlated with the level of policy support. Furthermore, all markets show a preference to deploy in rural areas and those with higher irradiation. Finally, local clustering of PV in all market segments was observed, revealing that PV is not spread evenly across areas. This work reveals the complex nature of PV deployment, both spatially and by market segment, reinforcing the need capture this through mapping.

  10. Effects of geographical extent on the determinants of woody plant diversity

    DEFF Research Database (Denmark)

    Wang, Zhiheng; Rahbek, Carsten; Fang, Jingyun

    2012-01-01

    Despite a long history of study, the mechanisms underlying the geographical patterns of species richness are still controversial. Patterns and determinants of species richness are well-known to vary with spatial scale. However, most studies on the effects of scale have focused on grain size where...

  11. Pre-Service Geography Teachers' Confidence in Geographical Subject Matter Knowledge and Teaching Geographical Skills

    Science.gov (United States)

    Harte, Wendy; Reitano, Paul

    2015-01-01

    This research tracked the confidence of 16 undergraduate and postgraduate pre-service geography teachers as they completed a single semester, senior phase geography curriculum course. The study focused specifically on the pre-service teachers' confidence in geographical subject matter knowledge and their confidence in teaching geographical skills.…

  12. Pre-Service Geography Teachers' Confidence in Geographical Subject Matter Knowledge and Teaching Geographical Skills

    Science.gov (United States)

    Harte, Wendy; Reitano, Paul

    2015-01-01

    This research tracked the confidence of 16 undergraduate and postgraduate pre-service geography teachers as they completed a single semester, senior phase geography curriculum course. The study focused specifically on the pre-service teachers' confidence in geographical subject matter knowledge and their confidence in teaching geographical skills.…

  13. A Framework for Geographic Object-Based Image Analysis (GEOBIA) based on geographic ontology

    Science.gov (United States)

    Gu, H. Y.; Li, H. T.; Yan, L.; Lu, X. J.

    2015-06-01

    GEOBIA (Geographic Object-Based Image Analysis) is not only a hot topic of current remote sensing and geographical research. It is believed to be a paradigm in remote sensing and GIScience. The lack of a systematic approach designed to conceptualize and formalize the class definitions makes GEOBIA a highly subjective and difficult method to reproduce. This paper aims to put forward a framework for GEOBIA based on geographic ontology theory, which could implement "Geographic entities - Image objects - Geographic objects" true reappearance. It consists of three steps, first, geographical entities are described by geographic ontology, second, semantic network model is built based on OWL(ontology web language), at last, geographical objects are classified with decision rule or other classifiers. A case study of farmland ontology was conducted for describing the framework. The strength of this framework is that it provides interpretation strategies and global framework for GEOBIA with the property of objective, overall, universal, universality, etc., which avoids inconsistencies caused by different experts' experience and provides an objective model for mage analysis.

  14. MODELING FUZZY GEOGRAPHIC OBJECTS WITHIN FUZZY FIELDS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To improve the current GIS functions in describing geographic objects w ith fuzziness,this paper begins with a discussion on the distance measure of sp atial objects based on the theory of sets and an introduction of dilation and er osion operators.Under the assumption that changes of attributes in a geographic region are gradual,the analytic expressions for the fuzzy objects of points,l ines and areas,and the description of their formal structures are presented.Th e analytic model of geographic objects by means of fuzzy fields is developed.We have shown that the 9-intersection model proposed by Egenhofer and Franzosa (19 91) is a special case of the model presented in the paper.

  15. Training for Internationalization through Domestic Geographical Dispersion

    DEFF Research Database (Denmark)

    Santangelo, Grazia D.; Stucchi, Tamara

    Traditionally created to deal with the unfriendly domestic environment, business groups (BGs) are increasingly internationalizing. However, how BGs can reconcile their strictly domestic orientation with an international dimension still remains an open question. Drawing on arguments from...... organizational learning, we seek to solve this puzzle in relation to the internationalization of Indian BGs. In particular, we argue that in heterogeneous domestic emerging markets BG’s geographical dispersion across sub-national states provides training for internationalization. To internationalize successfully......, BGs need to develop the capability of managing geographically dispersed units in institutional heterogeneous contexts. Domestic geographical dispersion would indeed help the BG dealing with different regulations, customers and infrastructures. However, there is less scope for such training as BGs...

  16. Thematic cartography as a geographical application

    Directory of Open Access Journals (Sweden)

    Drago Perko

    2002-12-01

    Full Text Available A thematic map may be a geographical application (tool in itself or the basis for some other geographical work. The development of Slovene thematic cartography accelerated considerably following the independence of the country in 1991. From the viewpoint of content and technology, its greatest achievements are the Geographical Atlas of Slovenia and the National Atlas of Slovenia, which are outstanding achievements at the international level and of great significance for the promotion of Slovenia and Slovene geography and cartography. However, this rapid development has been accompanied by numerous problems, for example, the ignoring of various Slovene and international conventions for the preparation of maps including United Nations resolutions, Slovene and international (SIST ISO, and copyright laws.

  17. Mapping the geographical diffusion of new words

    CERN Document Server

    Eisenstein, Jacob; Smith, Noah A; Xing, Eric P

    2012-01-01

    Language in social media is rich with linguistic innovations, most strikingly in the new words and spellings that constantly enter the lexicon. Despite assertions about the power of social media to connect people across the world, we find that many of these neologisms are restricted to geographically compact areas. Even for words that become ubiquituous, their growth in popularity is often geographical, spreading from city to city. Thus, social media text offers a unique opportunity to study the diffusion of lexical change. In this paper, we show how an autoregressive model of word frequencies in social media can be used to induce a network of linguistic influence between American cities. By comparing the induced network with the geographical and demographic characteristics of each city, we can measure the factors that drive the spread of lexical innovation.

  18. Polymorphism of viral dsRNA in Xanthophyllomyces dendrorhous strains isolated from different geographic areas

    Directory of Open Access Journals (Sweden)

    Libkind Diego

    2009-10-01

    Full Text Available Abstract Background Strains of the astaxanthin producing yeast Xanthophyllomyces dendrorhous have been isolated from different cold regions around the earth, and the presence of double stranded RNA (dsRNA elements was described in some isolates. This kind of viruses is widely distributed among yeasts and filamentous fungi and, although generally are cryptic in function, their studies have been a key factor in the knowledge of important fungi. In this work, the characterization and genetic relationships among dsRNA elements were determined in strains representatives of almost all regions of the earth where X. dendrorhous have been isolated. Results Almost all strains of X. dendrorhous analyzed carry one, two or four dsRNA elements, of molecular sizes in the range from 0.8 to 5.0 kb. Different dsRNA-patterns were observed in strains with different geographic origin, being L1 (5.0 kb the common dsRNA element. By hybridization assays a high genomic polymorphism was observed among L1 dsRNAs of different X. dendrorhous strains. Contrary, hybridization was observed between L1 and L2 dsRNAs of strains from same or different regions, while the dsRNA elements of minor sizes (M, S1, and S2 present in several strains did not show hybridization with neither L1 or L2 dsRNAs. Along the growth curve of UCD 67-385 (harboring four dsRNAs an increase of L2 relative to L1 dsRNA was observed, whiles the S1/L1 ratio remains constant, as well as the M/L1 ratio of Patagonian strain. Strains cured of S2 dsRNA were obtained by treatment with anisomycin, and comparison of its dsRNA contents with uncured strain, revealed an increase of L1 dsRNA while the L2 and S1 dsRNA remain unaltered. Conclusion The dsRNA elements of X. dendrorhous are highly variable in size and sequence, and the dsRNA pattern is specific to the geographic region of isolation. Each L1 and L2 dsRNA are viral elements able to self replicate and to coexist into a cell, and L1 and S2 dsRNAs elements could

  19. Population structure in the native range predicts the spread of introduced marine species.

    Science.gov (United States)

    Gaither, Michelle R; Bowen, Brian W; Toonen, Robert J

    2013-06-07

    Forecasting invasion success remains a fundamental challenge in invasion biology. The effort to identify universal characteristics that predict which species become invasive has faltered in part because of the diversity of taxa and systems considered. Here, we use an alternative approach focused on the spread stage of invasions. FST, a measure of alternative fixation of alleles, is a common proxy for realized dispersal among natural populations, summarizing the combined influences of life history, behaviour, habitat requirements, population size, history and ecology. We test the hypothesis that population structure in the native range (FST) is negatively correlated with the geographical extent of spread of marine species in an introduced range. An analysis of the available data (29 species, nine phyla) revealed a significant negative correlation (R(2) = 0.245-0.464) between FST and the extent of spread of non-native species. Mode FST among pairwise comparisons between populations in the native range demonstrated the highest predictive power (R(2) = 0.464, p < 0.001). There was significant improvement when marker type was considered, with mtDNA datasets providing the strongest relationship (n = 21, R(2) = 0.333-0.516). This study shows that FST can be used to make qualitative predictions concerning the geographical extent to which a non-native marine species will spread once established in a new area.

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

    Science.gov (United States)

    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.

  1. África en el National Geographic

    OpenAIRE

    Cartagena, Andrés

    2011-01-01

    Por muchos años, el National Geographic Magazine sirvió como el único medio en el cual las personas leían sobre África. En mi trabajo propongo que la imagen que ha creado el National Geographic Magazine a través de sus artículos y fotos sobre el continente africano es una imagen exótica y en donde se exalta los valores imperialistas y los beneficios del colonialismo para África. Es una imagen en la que el continente es representado como un lugar a donde los estadounidenses pueden ir a hacer s...

  2. Location of geographical objects in crisis situations

    Science.gov (United States)

    Rybansky, M.; Kratochvil, V.

    2014-02-01

    This article summarizes the various expressions of object positioning using different coordinate data and different methods, such as use of maps, exploiting the properties of digital Global System for Mobile Communications (GSM) networks, Global Navigational Satellite Systems (GNSS), Inertial Navigation Systems (INS), Inertial Measurement Systems (IMS), hybrid methods and non-contact (remote sensing) methods; all with varying level of accuracy. Furthermore, the article describes some geographical identifiers and verbal means to describe location of geographical objects such as settlements, rivers, forest, roads, etc. All of the location methods have some advantages and disadvantages, especially in emergency situations, when usually the crisis management has a lack of time in a decision process.

  3. Power law olivine crystal size distributions in lithospheric mantle xenoliths

    Science.gov (United States)

    Armienti, P.; Tarquini, S.

    2002-12-01

    Olivine crystal size distributions (CSDs) have been measured in three suites of spinel- and garnet-bearing harzburgites and lherzolites found as xenoliths in alkaline basalts from Canary Islands, Africa; Victoria Land, Antarctica; and Pali Aike, South America. The xenoliths derive from lithospheric mantle, from depths ranging from 80 to 20 km. Their textures vary from coarse to porphyroclastic and mosaic-porphyroclastic up to cataclastic. Data have been collected by processing digital images acquired optically from standard petrographic thin sections. The acquisition method is based on a high-resolution colour scanner that allows image capturing of a whole thin section. Image processing was performed using the VISILOG 5.2 package, resolving crystals larger than about 150 μm and applying stereological corrections based on the Schwartz-Saltykov algorithm. Taking account of truncation effects due to resolution limits and thin section size, all samples show scale invariance of crystal size distributions over almost three orders of magnitude (0.2-25 mm). Power law relations show fractal dimensions varying between 2.4 and 3.8, a range of values observed for distributions of fragment sizes in a variety of other geological contexts. A fragmentation model can reproduce the fractal dimensions around 2.6, which correspond to well-equilibrated granoblastic textures. Fractal dimensions >3 are typical of porphyroclastic and cataclastic samples. Slight bends in some linear arrays suggest selective tectonic crushing of crystals with size larger than 1 mm. The scale invariance shown by lithospheric mantle xenoliths in a variety of tectonic settings forms distant geographic regions, which indicate that this is a common characteristic of the upper mantle and should be taken into account in rheological models and evaluation of metasomatic models.

  4. A diverse range of novel RNA viruses in geographically distinct honey bee populations

    NARCIS (Netherlands)

    Remnant, Emily J.; Shi, Mang; Buchmann, Gabriele; Blacquière, Tjeerd; Holmes, Edward C.; Beekman, Madeleine; Ashe, Alyson

    2017-01-01

    Understanding the diversity and consequences of viruses present in honey bees is critical for maintaining pollinator health and managing the spread of disease. The viral landscape of honey bees (Apis mellifera) has changed dramatically since the emergence of the parasitic mite Varroa destructor,

  5. Systemic range shift lags among a pollinator species assemblage following rapid climate change

    DEFF Research Database (Denmark)

    Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

    2012-01-01

    Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins. ...

  6. Bat distribution size or shape as determinant of viral richness in african bats.

    Directory of Open Access Journals (Sweden)

    Gaël D Maganga

    Full Text Available The rising incidence of emerging infectious diseases (EID is mostly linked to biodiversity loss, changes in habitat use and increasing habitat fragmentation. Bats are linked to a growing number of EID but few studies have explored the factors of viral richness in bats. These may have implications for role of bats as potential reservoirs. We investigated the determinants of viral richness in 15 species of African bats (8 Pteropodidae and 7 microchiroptera in Central and West Africa for which we provide new information on virus infection and bat phylogeny. We performed the first comparative analysis testing the correlation of the fragmented geographical distribution (defined as the perimeter to area ratio with viral richness in bats. Because of their potential effect, sampling effort, host body weight, ecological and behavioural traits such as roosting behaviour, migration and geographical range, were included into the analysis as variables. The results showed that the geographical distribution size, shape and host body weight have significant effects on viral richness in bats. Viral richness was higher in large-bodied bats which had larger and more fragmented distribution areas. Accumulation of viruses may be related to the historical expansion and contraction of bat species distribution range, with potentially strong effects of distribution edges on virus transmission. Two potential explanations may explain these results. A positive distribution edge effect on the abundance or distribution of some bat species could have facilitated host switches. Alternatively, parasitism could play a direct role in shaping the distribution range of hosts through host local extinction by virulent parasites. This study highlights the importance of considering the fragmentation of bat species geographical distribution in order to understand their role in the circulation of viruses in Africa.

  7. Spatial and temporal dynamics of fucoid populations (Ascophyllum nodosum and Fucus serratus: a comparison between central and range edge populations.

    Directory of Open Access Journals (Sweden)

    Rita M Araújo

    Full Text Available Persistence of populations at range edges relies on local population dynamics and fitness, in the case of geographically isolated populations of species with low dispersal potential. Focusing on spatial variations in demography helps to predict the long-term capability for persistence of populations across the geographical range of species' distribution. The demography of two ecological and phylogenetically close macroalgal species with different life history characteristics was investigated by using stochastic, stage-based matrix models. Populations of Ascophyllum nodosum and Fucus serratus were sampled for up to 4 years at central locations in France and at their southern range limits in Portugal. The stochastic population growth rate (λ(s of A. nodosum was lower and more variable in central than in southern sites whilst for F. serratus this trend was reversed with λ(s much lower and more variable in southern than in central populations. Individuals were larger in central than in southern populations for both species, which was reflected in the lower transition probabilities of individuals to larger size classes and higher probability of shrinkage in the southern populations. In both central and southern populations elasticity analysis (proportional sensitivity of population growth rate showed that fertility elements had a small contribution to λ(s that was more sensitive to changes in matrix transitions corresponding to survival. The highest elasticities were found for loop transitions in A. nodosum and for growth to larger size classes in F. serratus. Sensitivity analysis showed high selective pressure on individual growth for both species at both locations. The results of this study highlight the deterministic role of species-specific life-history traits in population demography across the geographical range of species. Additionally, this study demonstrates that individuals' life-transitions differ in vulnerability to environmental

  8. Methodology for classification of geographical features with remote sensing images: Application to tidal flats

    Science.gov (United States)

    Revollo Sarmiento, G. N.; Cipolletti, M. P.; Perillo, M. M.; Delrieux, C. A.; Perillo, Gerardo M. E.

    2016-03-01

    Tidal flats generally exhibit ponds of diverse size, shape, orientation and origin. Studying the genesis, evolution, stability and erosive mechanisms of these geographic features is critical to understand the dynamics of coastal wetlands. However, monitoring these locations through direct access is hard and expensive, not always feasible, and environmentally damaging. Processing remote sensing images is a natural alternative for the extraction of qualitative and quantitative data due to their non-invasive nature. In this work, a robust methodology for automatic classification of ponds and tidal creeks in tidal flats using Google Earth images is proposed. The applicability of our method is tested in nine zones with different morphological settings. Each zone is processed by a segmentation stage, where ponds and tidal creeks are identified. Next, each geographical feature is measured and a set of shape descriptors is calculated. This dataset, together with a-priori classification of each geographical feature, is used to define a regression model, which allows an extensive automatic classification of large volumes of data discriminating ponds and tidal creeks against other various geographical features. In all cases, we identified and automatically classified different geographic features with an average accuracy over 90% (89.7% in the worst case, and 99.4% in the best case). These results show the feasibility of using freely available Google Earth imagery for the automatic identification and classification of complex geographical features. Also, the presented methodology may be easily applied in other wetlands of the world and perhaps employing other remote sensing imagery.

  9. The U.S. Radiologist Workforce: An Analysis of Temporal and Geographic Variation by Using Large National Datasets.

    Science.gov (United States)

    Rosenkrantz, Andrew B; Hughes, Danny R; Duszak, Richard

    2016-04-01

    To determine recent trends related to temporal as well as national and statewide geographic variation in the U.S. radiologist and radiology resident workforce. This retrospective HIPAA-compliant study was exempted from the internal review board. Federal Area Health Resources Files and Medicare 5% research identifiable files were used to compute parameters related to the radiologist workforce. Geographic variation and annual temporal trends were analyzed. Pearson and Spearman correlations were assessed. Nationally, the number of radiology trainees increased 84.2% from a nadir in 1997 (3080 trainees) to 2011 (5674 trainees) and showed high state-to-state variation (range, 0-678 trainees in 2011). However, total radiologists nationally increased 39.2% from 1995 (27 906 radiologists) to 2011 (38 875 radiologists), and radiologists per 100 000 population nationally increased by 7.5% from 1995 (10.62%) to 2011 (11.42%), while showing high state-to-state variation (highest-to-lowest state ratio of 4.3). Radiologists' share of the overall physician workforce declined nationally by 8.8% from 1995 (4.0%) to 2011 (3.7%), with moderate state-to-state variation (highest-to-lowest state ratio of 1.7). Radiology trainee numbers exhibited weak-to-moderate positive state-by-state correlation with radiologists per 100 000 population (r = 0.292-0.532), but moderate-to-strong inverse correlation with the percentage of radiologists in rural practice (r = -0.464 to -0.635). Although the number of radiology trainees dramatically increased, radiologists per 100 000 population increased only slightly, and radiologists' share of the overall physician workforce declined. State-to-state variations in radiologist and radiology resident workforces are high, which suggests a potential role for geographic redistribution rather than changes in the overall workforce size.

  10. Geographic variation in resource allocation to the abdomen in geometrid moths

    Science.gov (United States)

    Kivelä, Sami M.; Välimäki, Panu; Carrasco, David; Mäenpää, Maarit I.; Mänttäri, Satu

    2012-08-01

    A resource allocation trade-off is expected when resources from a common pool are allocated to two or more traits. In holometabolous insects, resource allocation to different functions during metamorphosis relies completely on larval-derived resources. At adult eclosion, resource allocation to the abdomen at the expense of other body parts can be seen as a rough estimate of resource allocation to reproduction. Theory suggests geographic variation in resource allocation to the abdomen, but there are currently no empirical data on it. We measured resource allocation to the abdomen at adult eclosion in four geometrid moths along a latitudinal gradient. Resource (total dry material, carbon, nitrogen) allocation to the abdomen showed positive allometry with body size. We found geographic variation in resource allocation to the abdomen in each species, and this variation was independent of allometry in three species. Geographic variation in resource allocation to the abdomen was complex. Resource allocation to the abdomen was relatively high in partially bivoltine populations in two species, which fits theoretical predictions, but the overall support for theory is weak. This study indicates that the geographic variation in resource allocation to the abdomen is not an allometric consequence of geographic variation in resource acquisition (i.e., body size). Thus, there is a component of resource allocation that can evolve independently of resource acquisition. Our results also suggest that there may be intraspecific variation in the degree of capital versus income breeding.

  11. Fennel pondweed: a world citizen : geographic variation in life-cycle characteristics of the clonal water plant Potamogeton pectinatus L.

    NARCIS (Netherlands)

    Pilon, J.

    2002-01-01

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    The performance of broadly distributed plants is potentially constrained by geographic variation in climatic

  12. Fennel pondweed: a world citizen : geographic variation in life-cycle characteristics of the clonal water plant Potamogeton pectinatus L

    NARCIS (Netherlands)

    Pilon, J.

    2002-01-01

    SIZE=5>

    SIZE=2>  The performance of broadly distributed plants is potentially constrained by geographic variation in climatic factors. Several patterns of response have been proposed that can be considered of adaptive valu

  13. Geographic variation in the status signals of Polistes dominulus paper wasps.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Tibbetts

    Full Text Available Understanding intraspecific geographic variation in animal signals poses a challenging evolutionary problem. Studies addressing geographic variation typically focus on signals used in mate-choice, however, geographic variation in intrasexual signals involved in competition is also known to occur. In Polistes dominulus paper wasps, females have black facial spots that signal dominance: individuals wasps with more complex 'broken' facial patterns are better fighters and are avoided by rivals. Recent work suggests there is dramatic geographic variation in these visual signals of quality, though this variation has not been explicitly described or quantified. Here, we analyze variation in P. dominulus signals across six populations and explore how environmental conditions may account for this variation. Overall, we found substantial variation in facial pattern brokenness across populations and castes. Workers have less broken facial patterns than gynes and queens, which have similar facial patterns. Strepsipteran parasitism, body size and temperature are all correlated with the facial pattern variation, suggesting that developmental plasticity likely plays a key role in this variation. First, the extent of parasitism varies across populations and parasitized individuals have lower facial pattern brokenness than unparasitized individuals. Second, there is substantial variation in body size across populations and a weak but significant relationship between facial pattern brokenness and body size. Wasps from populations with smaller body size (e.g. Italy tend to have less broken facial patterns than wasps from populations with larger body size (e.g. New York, USA. Third, there is an apparent association between facial patterns and climate, with wasp from cooler locations tending to have higher facial pattern brokenness than wasps from warmer locations. Additional experimental work testing the causes and consequences of facial pattern variation will be

  14. The National Geographic Society's Teaching Geography Project.

    Science.gov (United States)

    Bockenhauer, Mark H.

    1993-01-01

    Contends that the National Geographic Society's Teaching Geography Project is an inservice teacher education success story. Describes the origins, objectives, and development of the project. Summarizes the impact of the project and contends that its success is the result of the workshop format and guided practice in instructional strategies. (CFR)

  15. Enhancing Geographic Learning and Literacy through Filmmaking

    Science.gov (United States)

    Dando, Christina E.; Chadwick, Jacob J.

    2014-01-01

    In this media-saturated society, students need to think more critically about the media they encounter and that they are producing. Through filmmaking, students can link geographic theory and the real world, bridging the distance from readings/lectures/discussions to the geography on the ground, making the abstract concrete. But constructing films…

  16. Studying the making of geographical knowledge

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Madsen, Lene Møller

    2009-01-01

    The article addresses the issue of being a ‘double' insider when conducting interviews. Double insider means being an insider both in relation to one's research matter - in the authors' case the making of geographical knowledge - and in relation to one's interviewees - our colleagues. The article...... to separate the two roles, but in reality they coexist and are intertwined....

  17. Every document has a geographical scope

    NARCIS (Netherlands)

    Andogah, G.; Bouma, G.; Nerbonne, J.

    2012-01-01

    It is a useful premise to assume that every document in a collection and every query issued to an information retrieval (IR) system are geography-dependent. If one can determine what area an article is about (i.e., its geographical scope), this information can be used to improve the accuracy with wh

  18. Secure Geographic Routing Protocols: Issues and Approaches

    CERN Document Server

    sookhak, Mehdi; Haghparast, Mahboobeh; ISnin, Ismail Fauzi

    2011-01-01

    In the years, routing protocols in wireless sensor networks (WSN) have been substantially investigated by researches. Most state-of-the-art surveys have focused on reviewing of wireless sensor network .In this paper we review the existing secure geographic routing protocols for wireless sensor network (WSN) and also provide a qualitative comparison of them.

  19. An Overview to Geographic Information Systems.

    Science.gov (United States)

    Cox, Allan B.

    1995-01-01

    Provides an introduction to geographic information systems (GIS); reviews the use of GIS in libraries; and presents some challenges, strengths, and opportunities for libraries and GIS. Discusses requirements and functions of a GIS and presents examples. Six figures illustrate the discussion. (JKP)

  20. Higher-dimensional modelling of geographic information

    NARCIS (Netherlands)

    Arroyo Ohori, G.A.K.

    2016-01-01

    Our world is three-dimensional and complex, continuously changing over time and appearing different at different scales. Yet, when we model it in a computer using Geographic Information Systems (GIS), we mostly use 2D representations, which essentially consist of linked points, lines and polygons. T