WorldWideScience
 
 
1

Torpor in birds: taxonomy, energetics, and ecology.  

UK PubMed Central (United Kingdom)

Recent reports on patterns and occurrence of torpor and other natural hypothermic states in birds have prompted a revision of many longstanding opinions. For instance, a larger assortment of birds covering a wider range of body mass than previously recognized uses energy-conserving mechanisms in the face of abundant food supplies. Thus, although acute energetic stress triggers the occurrence of hypometabolic states in many birds, energy deficits can no longer be regarded as the sole stimulus for avian torpor. Additionally, the phenology of this phenomenon (phases, duration, depth) shows more interspecific variation than previously appreciated, and traditional concepts of the phases of torpor are not always adequate. Hence, inclusive definitions of torpor based on physiological and/or behavioral criteria have become more difficult to formulate. However, average nighttime body temperature, which is highly consistent throughout the class Aves (38.54 degrees +/- 0.96 degrees C, n = 202), provides a convenient reference for detecting natural hypothermic states. Of the putative ecological factors associated with avian torpor, food specialization seems a prime candidate as an ultimate factor in the occurrence of this state in birds. With few exceptions, all of these animals capable of torpor are either frugivorous, nectarivorous, or insectivorous, suggesting a correlation between thermoregulatory pattern and predictability of food supply. To date, no clear answer exists as to whether the variety of thermoregulatory patterns evident in birds involves discrete mechanisms or merely steps in a physiological continuum. However, I suggest that the occurrence of differences in torpor patterns among closely related species (e.g., within families) favors the latter interpretation.

Schleucher E

2004-11-01

2

Torpor in birds: taxonomy, energetics, and ecology.  

Science.gov (United States)

Recent reports on patterns and occurrence of torpor and other natural hypothermic states in birds have prompted a revision of many longstanding opinions. For instance, a larger assortment of birds covering a wider range of body mass than previously recognized uses energy-conserving mechanisms in the face of abundant food supplies. Thus, although acute energetic stress triggers the occurrence of hypometabolic states in many birds, energy deficits can no longer be regarded as the sole stimulus for avian torpor. Additionally, the phenology of this phenomenon (phases, duration, depth) shows more interspecific variation than previously appreciated, and traditional concepts of the phases of torpor are not always adequate. Hence, inclusive definitions of torpor based on physiological and/or behavioral criteria have become more difficult to formulate. However, average nighttime body temperature, which is highly consistent throughout the class Aves (38.54 degrees +/- 0.96 degrees C, n = 202), provides a convenient reference for detecting natural hypothermic states. Of the putative ecological factors associated with avian torpor, food specialization seems a prime candidate as an ultimate factor in the occurrence of this state in birds. With few exceptions, all of these animals capable of torpor are either frugivorous, nectarivorous, or insectivorous, suggesting a correlation between thermoregulatory pattern and predictability of food supply. To date, no clear answer exists as to whether the variety of thermoregulatory patterns evident in birds involves discrete mechanisms or merely steps in a physiological continuum. However, I suggest that the occurrence of differences in torpor patterns among closely related species (e.g., within families) favors the latter interpretation. PMID:15674768

Schleucher, Elke

3

Staphylococcus pseudintermedius in the dog : taxonomy, diagnostics, ecology, epidemiology and pathogenicity  

DEFF Research Database (Denmark)

The dog is the natural host of Staphylococcus pseudintermedius. Many research efforts are currently being undertaken to expand our knowledge and understanding of this important canine commensal and opportunistic pathogen. The objective of this review is to summarize the current knowledge of the species, including the latest research outcomes, with emphasis on taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Despite the important taxonomic changes that have occurred over the past few years, the risk of misidentification in canine specimens is low and does not have serious consequences for clinical practice. Staphylococcus pseudintermedius carriage in the dog is more frequent and genetically heterogeneous compared with that of Staphylococcus aureus in man. It appears that these staphylococcal species have evolved separately through adaptation to their respective natural hosts and differ with regard to various aspects concerning ecology, population structure and evolution of antibiotic resistance.Further understanding of the ecology and epidemiology of S. pseudintermedius is hampered by the lack of a standard method for rapid and discriminatory typing and by the limited data available on longitudinal carriage and population structure of meticillin-susceptible strains. With regard to pathogenicity, it is only now that we are starting to explore the virulence potential of S. pseudintermedius based on genomic and proteomic approaches, and more research is needed to assess the importance of individual virulence factors and the possible existence of hypervirulent strains.

Bannoehr, Jeanette; Guardabassi, Luca

2012-01-01

4

[Distribution and taxonomy of Pyrgophorus platyrachis (Caenogastropoda: Hydrobiidae) in the Sistema de Maracaibo, Venezuela].  

Science.gov (United States)

The presence of a microgastropod identified as Potamopyrgus sp. was detected previously in the Maracaibo System; nevertheless, a detailed morphological analysis identified this snail in other genera. The objective of this work is to update the distribution and taxonomy of Pyrgophorus platyrachis in the Maracaibo System, Venezuela in samples obtained between 2001 and 2009. The presence of hundreds of individuals of P. platyrachis were observed in the estuary, indeed in the localities of the Gran Eneal lagoon (4 111 snails), Peonías lagoon (229 snails), Punta Capitán Chico (758 snails), San Francisco (2 517 snails), Curarire (240 snails), Apon River mouth (173 snails), Ojeda City (240 snails), Bachaquero (128 snails) and Tomoporo de Agua (385 snails). We performed a taxonomical analysis, and emphasized in ecological aspects, such as the distribution of the species and habitat features, as near vegetation and type of associated sediment. We found three morphotypes of the species, one smooth, another with spiral striations and the other with spines. Smooth morphotype was exclusive of the Gran Eneal lagoon, Peonías lagoon, Punta Capitan Chico and Apon River mouth localities, whereas the other two morphotypes were found together in the remaining localities. According to our detailed anatomical and taxonomical analysis we propose a synonymy between P. platyrachis and the other species described like Pyrgophorus parvulus and Pyrgophorus spinosus. PMID:22017122

Nava, Mario; Severeyn, Héctor; Machado, Nakary

2011-09-01

5

[Distribution and taxonomy of Pyrgophorus platyrachis (Caenogastropoda: Hydrobiidae) in the Sistema de Maracaibo, Venezuela].  

UK PubMed Central (United Kingdom)

The presence of a microgastropod identified as Potamopyrgus sp. was detected previously in the Maracaibo System; nevertheless, a detailed morphological analysis identified this snail in other genera. The objective of this work is to update the distribution and taxonomy of Pyrgophorus platyrachis in the Maracaibo System, Venezuela in samples obtained between 2001 and 2009. The presence of hundreds of individuals of P. platyrachis were observed in the estuary, indeed in the localities of the Gran Eneal lagoon (4 111 snails), Peonías lagoon (229 snails), Punta Capitán Chico (758 snails), San Francisco (2 517 snails), Curarire (240 snails), Apon River mouth (173 snails), Ojeda City (240 snails), Bachaquero (128 snails) and Tomoporo de Agua (385 snails). We performed a taxonomical analysis, and emphasized in ecological aspects, such as the distribution of the species and habitat features, as near vegetation and type of associated sediment. We found three morphotypes of the species, one smooth, another with spiral striations and the other with spines. Smooth morphotype was exclusive of the Gran Eneal lagoon, Peonías lagoon, Punta Capitan Chico and Apon River mouth localities, whereas the other two morphotypes were found together in the remaining localities. According to our detailed anatomical and taxonomical analysis we propose a synonymy between P. platyrachis and the other species described like Pyrgophorus parvulus and Pyrgophorus spinosus.

Nava M; Severeyn H; Machado N

2011-09-01

6

Taxonomy, ecology, and geographical distribution of the species of the genus Thermocyclops Kiefer, 1927 (Copepoda, Cyclopoida) in São Paulo State, Brazil, with description of a new species/ Taxonomia, ecologia e distribuição geográfica das espécies do gênero Thermocyclops Kiefer, 1927 no estado de São Paulo, com a descrição de uma espécie nova  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Foram realizadas coletas em 207 corpos de água, distribuídos em 22 unidades de gerenciamento de recursos hídricos (UHGRH) do estado de São Paulo no período de 1999 a 2002, abrangendo grandes e pequenos reservatórios, lagoas marginais e grandes rios. Nestas coletas foram analisadas as espécies do gênero Thermocyclops quanto à taxonomia, distribuição geográfica e freqüência de ocorrência. O gênero Thermocyclops ocorreu em corpos de água com zona limnética (more) bem desenvolvida e com raras exceções em ambientes estritamente litorâneos. Foram registradas quatro espécies, sendo Thermcyclops iguapensis espécie nova, que ocorreu nos reservatórios das UHGRHs Ribeira do Iguape e Paraíba do Sul. A descrição da espécie nova e a distribuição das quatro espécies são apresentadas, mostrando que Thermocyclops decipiens foi a espécie mais freqüente, ocorrendo em 71% dos corpos de água com região limnética desenvolvida. Esta espécie é característica de ambientes eutróficos, onde ocorre em grande número, e a espécie Thermocyclops minutus é característica de ambientes oligotróficos. Thermocyclops inversus e Thermocyclops iguapensis n. sp. não são espécies freqüentes, mas podem co-ocorrer com a espécie Thermocyclops decipiens. Abstract in english The taxonomy and ecology of the cyclopoid copepod genus Thermocyclops were studied. Samples were collected in 207 water bodies located in the 22 hydrographic basins of São Paulo State, Brazil, including large reservoirs, small and shallow lakes, and ponds and rivers. The genus Thermocyclops inhabits mainly water bodies within a limnetic region. Four species were found, of which one is new: Thermocyclops iguapensis, which occurred in the reservoirs of the Ribeira do Iguap (more) e and Paraíba do Sul basins. The description of the new species and the geographical distribution of all four species in São Paulo State are presented. Thermocyclops decipiens was the most frequent species, occurring in 71% of the water bodies within a limnetic region. This species is characteristic of eutrophic environments where it can occur in great abundance, whereas Thermocyclops minutus is characteristic in oligotrophic systems. Thermocyclops inversus and Thermocyclops iguapensis n. sp. were not common but can occur together with Thermocyclops decipiens.

Silva, W. M.; Matsumura-Tundisi, T.

2005-08-01

7

Taxonomy, ecology, and geographical distribution of the species of the genus Thermocyclops Kiefer, 1927 (Copepoda, Cyclopoida) in São Paulo State, Brazil, with description of a new species Taxonomia, ecologia e distribuição geográfica das espécies do gênero Thermocyclops Kiefer, 1927 no estado de São Paulo, com a descrição de uma espécie nova  

Directory of Open Access Journals (Sweden)

Full Text Available The taxonomy and ecology of the cyclopoid copepod genus Thermocyclops were studied. Samples were collected in 207 water bodies located in the 22 hydrographic basins of São Paulo State, Brazil, including large reservoirs, small and shallow lakes, and ponds and rivers. The genus Thermocyclops inhabits mainly water bodies within a limnetic region. Four species were found, of which one is new: Thermocyclops iguapensis, which occurred in the reservoirs of the Ribeira do Iguape and Paraíba do Sul basins. The description of the new species and the geographical distribution of all four species in São Paulo State are presented. Thermocyclops decipiens was the most frequent species, occurring in 71% of the water bodies within a limnetic region. This species is characteristic of eutrophic environments where it can occur in great abundance, whereas Thermocyclops minutus is characteristic in oligotrophic systems. Thermocyclops inversus and Thermocyclops iguapensis n. sp. were not common but can occur together with Thermocyclops decipiens.Foram realizadas coletas em 207 corpos de água, distribuídos em 22 unidades de gerenciamento de recursos hídricos (UHGRH) do estado de São Paulo no período de 1999 a 2002, abrangendo grandes e pequenos reservatórios, lagoas marginais e grandes rios. Nestas coletas foram analisadas as espécies do gênero Thermocyclops quanto à taxonomia, distribuição geográfica e freqüência de ocorrência. O gênero Thermocyclops ocorreu em corpos de água com zona limnética bem desenvolvida e com raras exceções em ambientes estritamente litorâneos. Foram registradas quatro espécies, sendo Thermcyclops iguapensis espécie nova, que ocorreu nos reservatórios das UHGRHs Ribeira do Iguape e Paraíba do Sul. A descrição da espécie nova e a distribuição das quatro espécies são apresentadas, mostrando que Thermocyclops decipiens foi a espécie mais freqüente, ocorrendo em 71% dos corpos de água com região limnética desenvolvida. Esta espécie é característica de ambientes eutróficos, onde ocorre em grande número, e a espécie Thermocyclops minutus é característica de ambientes oligotróficos. Thermocyclops inversus e Thermocyclops iguapensis n. sp. não são espécies freqüentes, mas podem co-ocorrer com a espécie Thermocyclops decipiens.

W. M. Silva; T. Matsumura-Tundisi

2005-01-01

8

An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea.  

Science.gov (United States)

Reference phylogenies are crucial for providing a taxonomic framework for interpretation of marker gene and metagenomic surveys, which continue to reveal novel species at a remarkable rate. Greengenes is a dedicated full-length 16S rRNA gene database that provides users with a curated taxonomy based on de novo tree inference. We developed a 'taxonomy to tree' approach for transferring group names from an existing taxonomy to a tree topology, and used it to apply the Greengenes, National Center for Biotechnology Information (NCBI) and cyanoDB (Cyanobacteria only) taxonomies to a de novo tree comprising 408,315 sequences. We also incorporated explicit rank information provided by the NCBI taxonomy to group names (by prefixing rank designations) for better user orientation and classification consistency. The resulting merged taxonomy improved the classification of 75% of the sequences by one or more ranks relative to the original NCBI taxonomy with the most pronounced improvements occurring in under-classified environmental sequences. We also assessed candidate phyla (divisions) currently defined by NCBI and present recommendations for consolidation of 34 redundantly named groups. All intermediate results from the pipeline, which includes tree inference, jackknifing and transfer of a donor taxonomy to a recipient tree (tax2tree) are available for download. The improved Greengenes taxonomy should provide important infrastructure for a wide range of megasequencing projects studying ecosystems on scales ranging from our own bodies (the Human Microbiome Project) to the entire planet (the Earth Microbiome Project). The implementation of the software can be obtained from http://sourceforge.net/projects/tax2tree/. PMID:22134646

McDonald, Daniel; Price, Morgan N; Goodrich, Julia; Nawrocki, Eric P; DeSantis, Todd Z; Probst, Alexander; Andersen, Gary L; Knight, Rob; Hugenholtz, Philip

2011-12-01

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An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea.  

UK PubMed Central (United Kingdom)

Reference phylogenies are crucial for providing a taxonomic framework for interpretation of marker gene and metagenomic surveys, which continue to reveal novel species at a remarkable rate. Greengenes is a dedicated full-length 16S rRNA gene database that provides users with a curated taxonomy based on de novo tree inference. We developed a 'taxonomy to tree' approach for transferring group names from an existing taxonomy to a tree topology, and used it to apply the Greengenes, National Center for Biotechnology Information (NCBI) and cyanoDB (Cyanobacteria only) taxonomies to a de novo tree comprising 408,315 sequences. We also incorporated explicit rank information provided by the NCBI taxonomy to group names (by prefixing rank designations) for better user orientation and classification consistency. The resulting merged taxonomy improved the classification of 75% of the sequences by one or more ranks relative to the original NCBI taxonomy with the most pronounced improvements occurring in under-classified environmental sequences. We also assessed candidate phyla (divisions) currently defined by NCBI and present recommendations for consolidation of 34 redundantly named groups. All intermediate results from the pipeline, which includes tree inference, jackknifing and transfer of a donor taxonomy to a recipient tree (tax2tree) are available for download. The improved Greengenes taxonomy should provide important infrastructure for a wide range of megasequencing projects studying ecosystems on scales ranging from our own bodies (the Human Microbiome Project) to the entire planet (the Earth Microbiome Project). The implementation of the software can be obtained from http://sourceforge.net/projects/tax2tree/.

McDonald D; Price MN; Goodrich J; Nawrocki EP; DeSantis TZ; Probst A; Andersen GL; Knight R; Hugenholtz P

2012-03-01

10

An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reference phylogenies are crucial for providing a taxonomic framework for interpretation of marker gene and metagenomic surveys, which continue to reveal novel species at a remarkable rate. Greengenes is a dedicated full-length 16S rRNA gene database that provides users with a curated taxonomy based...

McDonald, Daniel; Price, Morgan N; Goodrich, Julia; Nawrocki, Eric P; DeSantis, Todd Z; Probst, Alexander; Andersen, Gary L

11

Taxonomy and distribution pattern of the African rain forest butterfly genus Euphaedra Hubner sensu stricto with the description of three new subspecies of Euphaedra cyparissa (Cramer) and one of E. sarcoptera (Butler) (Lepidoptera, Nymphalidae, Limenitidinae, Adoliadini).  

UK PubMed Central (United Kingdom)

Updated data on the distribution, ecology and taxonomy of Euphaedra cyparissa (Cramer) and Euphaedra sarcoptera (Butler) are presented. Three new subspecies of Euphaedra cyparissa and one of Euphaedra sarcoptera are described and their geographic distribution is presented. The monophyly of the genus Euphaedra sensu Hecq is assessed based on morphological, in particular male and female genitalia, and behavioural traits. Possible evolutionary reasons for the convergence of colour pattern between the sympatric subspecies of Euphaedra cyparissa and Euphaedra sarcoptera are discussed.

Pyrcz TW; Warren-Gash H; Lorenc-Brudecka J; Dieuwko Knoop; Oremans P; Sáfián S

2013-01-01

12

[The taxonomy and distribution of Nathalis (Lepidoptera: Pieridae) in Colombia].  

UK PubMed Central (United Kingdom)

In Colombia, Nathalis has two described species: N. iole and N. plauta. Previous authors did not make detailed descriptions of its distribution in meridional regions and failed to differentiate both species based on genitalic characters. Some wing marks have been enough to separate them, but co-specificity was a possibility. They inhabit Colombia above 2000 m in the paramo, and have a vicariant distribution from the remaining population of N. iole in the Antillean and Central and North America. An analysis focused on male and female genitalia, as well as the wing pattern of more than 100 specimens from the Colombian Andes (Sierra Nevada de Santa Marta and Sierra de Perijá) and Mexico, indicates that the two species differ in their genitalia, and considering their allopatric distribution, we support the specific distinction of N. iole and N. plauta. We describe a new endemic subspecies found exclusively in the paramo above 3000 m, an area where other endemics occur. It has phenotypic plasticity related to environmental factors.

Pulido-B HW; Andrade-C MG; Llorente-Bousquets J

2010-03-01

13

[The taxonomy and distribution of Nathalis (Lepidoptera: Pieridae) in Colombia].  

Science.gov (United States)

In Colombia, Nathalis has two described species: N. iole and N. plauta. Previous authors did not make detailed descriptions of its distribution in meridional regions and failed to differentiate both species based on genitalic characters. Some wing marks have been enough to separate them, but co-specificity was a possibility. They inhabit Colombia above 2000 m in the paramo, and have a vicariant distribution from the remaining population of N. iole in the Antillean and Central and North America. An analysis focused on male and female genitalia, as well as the wing pattern of more than 100 specimens from the Colombian Andes (Sierra Nevada de Santa Marta and Sierra de Perijá) and Mexico, indicates that the two species differ in their genitalia, and considering their allopatric distribution, we support the specific distinction of N. iole and N. plauta. We describe a new endemic subspecies found exclusively in the paramo above 3000 m, an area where other endemics occur. It has phenotypic plasticity related to environmental factors. PMID:20411722

Pulido-B, Hannier W; Andrade-C, M Gonzalo; Llorente-Bousquets, Jorge

2010-03-01

14

Ascidians at Currais islands, Paraná, Brazil: taxonomy and distribution  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese As Ilhas Currais são formadas por um grupo de três pequenas formações rochosas localizadas no Estado do Paraná, sul do Brasil, sendo um local de interesse para o estudo do grupo Ascidiacea. A diversidade da região sublitoral local é bastante alta, e Currais foi recentemente proposto como local a ser transformado em Unidade de Conservação. Foi desenvolvido um estudo de campo na maior das três ilhas, com o intuito de se conhecer a distribuição espacial e tempora (more) l de ascídias. Foram realizadas três amostragens entre 2002 e 2003, nos lados norte e sul da ilha, em três diferentes profundidades. Vinte espécies foram registradas, sendo as mais comuns Didemnum rodriguesi, Didemnum speciosum e Didemnum granulatum. Três são possíveis espécies novas e serão descritas futuramente. Nove espécies representam novos registros para o Estado do Paraná: Perophora regina, Didemnum speciosum, Trididemnum orbiculatum, Eudistoma carolinense, Aplidium pentatrema, Molgula phytophila, Botryllus tuberatus, Symplegma brakenhielmi e Polyandrocarpa anguinea. As espécies encontram-se distribuídas principalmente entre a faixa dos seis aos 15 m, tendo sido observada uma redução da abundância em profundidades maiores de 15 m. Algumas espécies parecem preferir o lado norte da ilha. Algumas espécies apresentam variações temporais de abundância, sendo mais comuns ou na primavera ou no verão, mas não é possível ainda afirmar que exista um padrão sazonal entre anos. Abstract in english The Currais Islands is a group of a few small rocky islands in the state of Paraná, in southern Brazil, which provides an interesting location for the study of ascidians. Subtidal diversity is very high and the islands have recently been proposed as a Conservation Unit. A field study was established on the largest island to understand ascidian distributions on spatial and temporal scales. Transects, sampled three times during 2002 and 2003, were established on northern a (more) nd southern locations of the island as well as at three depths. Twenty species were recorded; the most common were Didemnum rodriguesi, Didemnum speciosum and Didemnum granulatum. Three species are possibly new and will be described elsewhere. An additional nine are new records for the state of Paraná: Perophora regina, Didemnum speciosum, Trididemnum orbiculatum, Eudistoma carolinense, Aplidium pentatrema, Molgula phytophila, Botryllus tuberatus, Symplegma brakenhielmi and Polyandrocarpa anguinea. While all these species are distributed between 6 and 15 m, there is a tendency to reduction of abundance towards 15 m in several species. Some species appear to prefer the north side of the island. Several species show temporal changes in abundance, with some being most common in the spring and others in the summer, but we can not affirm yet that there is a seasonal pattern between years.

Rocha, Rosana Moreira da; Faria, Suzana Barros de

2005-01-01

15

Mapping the Distribution of Taxonomies and Mineralogies in the Asteroid Main Belt Using the SDSS MOC4  

Science.gov (United States)

In the present work we define a taxonomic scheme based on the SDSS colors [1] that seeks to be compatible with previous taxonomic schemes based on spectroscopic data [2,3]. This taxonomy is then applied to the asteroids listed on the forth release of the SDSS Moving Object Catalogue (MOC4) and to meteorite spectra from the RELAB database. These results are then used to analyze the distributions of taxonomies in the Main Asteroid Belt and, based on it, make inferences about the distribution of mineralogies. We also use the large number of asteroids that were observed multiple times in the MOC4 to analyze the issue of taxonomic variations among observations. Since no conclusions about mineralogy can be draw based solely on taxonomy, the ultimate goal here is to identify interesting targets for NIR spectroscopic follow up. [1] Ivezic et al., AJ 122, 2749 (2001) [2] Tholen and Barucci, Asteroids II, (1989) [3] Bus and Binzel, Icarus 158, 146 (2002)

Lazzaro, Daniela; Carvano, J.; Hasselmann, P. A.; Mothé-Diniz, T.

2009-09-01

16

The genus Oxyrhopus (Serpentes: Dipsadidae: Xenodontinae) in Guyana: morphology, distributions and comments on taxonomy  

Directory of Open Access Journals (Sweden)

Full Text Available Considerable confusion exists regarding taxonomy and distributions of Oxyrhopus in northern South America. Specimens and records of Oxyrhopus from Guyana were examined. Oxyrhopus melanogenys, O. occipitalis and O. petola occur in Guyana. Data on morphology and colouration of these species are presented. Species distributions and characters to distinguish among the species are discussed.Existe uma considerável confusão sobre a taxonomia e distribuições de Oxyrhopus no norte da América do Sul. Os espécimes e registros de Oxyrhopus da Guyana foram examinados. Oxyrhopus melanogenys, O. occipitalis e O. petola ocorre na Guyana. Os dados de morfologia e coloração destas espécies são apresentados. As distribuições destas espécies e caracteres para distinguir essas espécies são discutidos.

Ross D. MacCulloch; Amy Lathrop; Philippe J. R. Kok; Raffael Ernst; Michelle Kalamandeen

2009-01-01

17

A survey and taxonomy of distributed certificate authorities in mobile ad hoc networks  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Certificate authorities (CAs) are the main components of PKI that enable us for providing basic security services in wired networks and Internet. But, we cannot use centralized CAs, in mobile ad hoc networks (MANETs). So, many efforts have been made to adapt CA to the special characteristics of MANETs and new concepts such as distributed CAs (DCAs) have been proposed that distribute the functionality of CA between MANET nodes. In this article, we study various proposed DCA schemes for MANET and then classify these schemes according to their internal structures and techniques. Finally, we propose the characteristics of an ideal DCA system that can be used to verify the completeness of any DCA scheme. This classification and taxonomy identify the weakness and constraints of each scheme, and are very important for designing more secure, scalable, and high performance DCA systems for MANETs and other networks.

Masdari Mohammad; Jabbehdari Sam; Ahmadi Mohammad; Hashemi Seyyed; Bagherzadeh Jamshid; Khadem-Zadeh Ahmad

2011-01-01

18

The genus Oxyrhopus (Serpentes: Dipsadidae: Xenodontinae) in Guyana: morphology, distributions and comments on taxonomy  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Existe uma considerável confusão sobre a taxonomia e distribuições de Oxyrhopus no norte da América do Sul. Os espécimes e registros de Oxyrhopus da Guyana foram examinados. Oxyrhopus melanogenys, O. occipitalis e O. petola ocorre na Guyana. Os dados de morfologia e coloração destas espécies são apresentados. As distribuições destas espécies e caracteres para distinguir essas espécies são discutidos. Abstract in english Considerable confusion exists regarding taxonomy and distributions of Oxyrhopus in northern South America. Specimens and records of Oxyrhopus from Guyana were examined. Oxyrhopus melanogenys, O. occipitalis and O. petola occur in Guyana. Data on morphology and colouration of these species are presented. Species distributions and characters to distinguish among the species are discussed.

MacCulloch, Ross D.; Lathrop, Amy; Kok, Philippe J. R.; Ernst, Raffael; Kalamandeen, Michelle

2009-01-01

19

Deep Coral and Associated Species Taxonomy and Ecology (DeepCAST) II Expedition Report.  

Science.gov (United States)

NOAA has a mandate to explore and understand deep-sea coral ecology under Magnuson-Stevens Sustainable Fisheries Conservation Act Reauthorization of 2009. Deep-sea corals are increasingly considered a proxy for marine biodiversity in the deep-sea because ...

K. A. Lavelle P. J. Etnoyer T. C. Shirley

2011-01-01

20

Parametric survival analysis and taxonomy of hazard functions for the generalized gamma distribution.  

Science.gov (United States)

The widely used Cox proportional hazards regression model for the analysis of censored survival data has limited utility when either hazard functions themselves are of primary interest, or when relative times instead of relative hazards are the relevant measures of association. Parametric regression models are an attractive option in situations such as this, although the choice of a particular model from the available families of distributions can be problematic. The generalized gamma (GG) distribution is an extensive family that contains nearly all of the most commonly used distributions, including the exponential, Weibull, log normal and gamma. More importantly, the GG family includes all four of the most common types of hazard function: monotonically increasing and decreasing, as well as bathtub and arc-shaped hazards. We present here a taxonomy of the hazard functions of the GG family, which includes various special distributions and allows depiction of effects of exposures on hazard functions. We applied the proposed taxonomy to study survival after a diagnosis of clinical AIDS during different eras of HIV therapy, where proportionality of hazard functions was clearly not fulfilled and flexibility in estimating hazards with very different shapes was needed. Comparisons of survival after AIDS in different eras of therapy are presented in terms of both relative times and relative hazards. Standard errors for these and other derived quantities are computed using the delta method and checked using the bootstrap. Description of standard statistical software (Stata, SAS and S-Plus) for the computations is included and available at http://statepi.jhsph.edu/software. PMID:17342754

Cox, Christopher; Chu, Haitao; Schneider, Michael F; Muñoz, Alvaro

2007-10-15

 
 
 
 
21

Parametric survival analysis and taxonomy of hazard functions for the generalized gamma distribution.  

UK PubMed Central (United Kingdom)

The widely used Cox proportional hazards regression model for the analysis of censored survival data has limited utility when either hazard functions themselves are of primary interest, or when relative times instead of relative hazards are the relevant measures of association. Parametric regression models are an attractive option in situations such as this, although the choice of a particular model from the available families of distributions can be problematic. The generalized gamma (GG) distribution is an extensive family that contains nearly all of the most commonly used distributions, including the exponential, Weibull, log normal and gamma. More importantly, the GG family includes all four of the most common types of hazard function: monotonically increasing and decreasing, as well as bathtub and arc-shaped hazards. We present here a taxonomy of the hazard functions of the GG family, which includes various special distributions and allows depiction of effects of exposures on hazard functions. We applied the proposed taxonomy to study survival after a diagnosis of clinical AIDS during different eras of HIV therapy, where proportionality of hazard functions was clearly not fulfilled and flexibility in estimating hazards with very different shapes was needed. Comparisons of survival after AIDS in different eras of therapy are presented in terms of both relative times and relative hazards. Standard errors for these and other derived quantities are computed using the delta method and checked using the bootstrap. Description of standard statistical software (Stata, SAS and S-Plus) for the computations is included and available at http://statepi.jhsph.edu/software.

Cox C; Chu H; Schneider MF; Muñoz A

2007-10-01

22

Forty years of carabid beetle research in Europe - from taxonomy, biology, ecology and population studies to bioindication, habitat assessment and conservation.  

UK PubMed Central (United Kingdom)

'Carabidologists do it all' (Niemelä 1996a) is a phrase with which most European carabidologists are familiar. Indeed, during the last half a century, professional and amateur entomologists have contributed enormously to our understanding of the basic biology of carabid beetles. The success of the field is in no small part due to regular European Carabidologists' Meetings, which started in 1969 in Wijster, the Netherlands, with the 14th meeting again held in the Netherlands in 2009, celebrating the 40th anniversary of the first meeting and 50 years of long-term research in the Dwingelderveld. This paper offers a subjective summary of some of the major developments in carabidology since the 1960s. Taxonomy of the family Carabidae is now reasonably established, and the application of modern taxonomic tools has brought up several surprises like elsewhere in the animal kingdom. Progress has been made on the ultimate and proximate factors of seasonality and timing of reproduction, which only exceptionally show non-seasonality. Triggers can be linked to evolutionary events and plausibly explained by the "taxon cycle" theory. Fairly little is still known about certain feeding preferences, including granivory and ants, as well as unique life history strategies, such as ectoparasitism and predation on higher taxa. The study of carabids has been instrumental in developing metapopulation theory (even if it was termed differently). Dispersal is one of the areas intensively studied, and results show an intricate interaction between walking and flying as the major mechanisms. The ecological study of carabids is still hampered by some unresolved questions about sampling and data evaluation. It is recognised that knowledge is uneven, especially concerning larvae and species in tropical areas. By their abundance and wide distribution, carabid beetles can be useful in population studies, bioindication, conservation biology and landscape ecology. Indeed, 40 years of carabidological research have provided so much data and insights, that among insects - and arguably most other terrestrial organisms - carabid beetles are one of the most worthwhile model groups for biological studies.

Kotze DJ; Brandmayr P; Casale A; Dauffy-Richard E; Dekoninck W; Koivula MJ; Lövei GL; Mossakowski D; Noordijk J; Paarmann W; Pizzolotto R; Saska P; Schwerk A; Serrano J; Szyszko J; Taboada A; Turin H; Venn S; Vermeulen R; Zetto T

2011-01-01

23

Ecological Studies on Salix Distribution in Egypt  

Directory of Open Access Journals (Sweden)

Full Text Available The present research studied the ecological factors affecting Salix distribution in Egypt. Two species of Salix were recorded, S. tetrasperma (only male) and S. mucronata (both sexes). They were recorded at River Nile canal system and in the Eastern Oasis. Female S. mucronata was recorded in the all studied habitats, where the male of same species was recorded only in Fayoum Region. Salix tetrasperma neither recorded in Upper Egypt nor Eastern Oasis. Elevation from water surface, soil texture, soil salinity and temperature were the most effective factors affecting the distribution of Salix sp.

Emad A. Al Sherif; Wafaa Amer; Salah Eldin Ali Khodary; Walaa Azmy

2009-01-01

24

Bioactivity of fungal endophytes as a function of endophyte taxonomy and the taxonomy and distribution of their host plants.  

UK PubMed Central (United Kingdom)

Fungal endophytes - fungi that grow within plant tissues without causing immediate signs of disease - are abundant and diverse producers of bioactive secondary metabolites. Endophytes associated with leaves of tropical plants are an especially exciting and relatively untapped source of novel compounds. However, one major challenge in drug discovery lies in developing strategies to efficiently recover highly bioactive strains. As part of a 15-year drug discovery project, foliar endophytes were isolated from 3198 plant samples (51 orders, 105 families and at least 232 genera of angiosperms and ferns) collected in nine geographically distinct regions of Panama. Extracts from culture supernatants of >2700 isolates were tested for bioactivity (in vitro percent inhibition of growth, % IG) against a human breast cancer cell line (MCF-7) and the causative agents of malaria, leishmaniasis, and Chagas' disease. Overall, 32.7% of endophyte isolates were highly active in at least one bioassay, including representatives of diverse fungal lineages, host lineages, and collection sites. Up to 17% of isolates tested per assay were highly active. Most bioactive strains were active in only one assay. Fungal lineages differed in the incidence and degree of bioactivity, as did fungi from particular plant taxa, and greater bioactivity was observed in endophytes isolated from plants in cloud forests vs. lowland forests. Our results suggest that using host taxonomy and forest type to tailor plant collections, and selecting endophytes from specific orders or families for cultivation, will markedly increase the efficiency and efficacy of discovering bioactive metabolites for particular pharmaceutical targets.

Higginbotham SJ; Arnold AE; Ibañez A; Spadafora C; Coley PD; Kursar TA

2013-01-01

25

Bioactivity of fungal endophytes as a function of endophyte taxonomy and the taxonomy and distribution of their host plants.  

Science.gov (United States)

Fungal endophytes - fungi that grow within plant tissues without causing immediate signs of disease - are abundant and diverse producers of bioactive secondary metabolites. Endophytes associated with leaves of tropical plants are an especially exciting and relatively untapped source of novel compounds. However, one major challenge in drug discovery lies in developing strategies to efficiently recover highly bioactive strains. As part of a 15-year drug discovery project, foliar endophytes were isolated from 3198 plant samples (51 orders, 105 families and at least 232 genera of angiosperms and ferns) collected in nine geographically distinct regions of Panama. Extracts from culture supernatants of >2700 isolates were tested for bioactivity (in vitro percent inhibition of growth, % IG) against a human breast cancer cell line (MCF-7) and the causative agents of malaria, leishmaniasis, and Chagas' disease. Overall, 32.7% of endophyte isolates were highly active in at least one bioassay, including representatives of diverse fungal lineages, host lineages, and collection sites. Up to 17% of isolates tested per assay were highly active. Most bioactive strains were active in only one assay. Fungal lineages differed in the incidence and degree of bioactivity, as did fungi from particular plant taxa, and greater bioactivity was observed in endophytes isolated from plants in cloud forests vs. lowland forests. Our results suggest that using host taxonomy and forest type to tailor plant collections, and selecting endophytes from specific orders or families for cultivation, will markedly increase the efficiency and efficacy of discovering bioactive metabolites for particular pharmaceutical targets. PMID:24066037

Higginbotham, Sarah J; Arnold, A Elizabeth; Ibañez, Alicia; Spadafora, Carmenza; Coley, Phyllis D; Kursar, Thomas A

2013-09-16

26

Demography of birds in a neotropical forest: Effects of allometry, taxonomy, and ecology  

Science.gov (United States)

Comparative demographic studies of terrestrial vertebrates have included few samples of species from tropical forests. We analyzed 9 yr of mark-recapture data and estimated demographic parameters for 25 species of birds inhabiting lowland forests in central Panama. These species were all songbirds (Order Passeriformes) ranging in mass from 7 to 57 g. Using Jolly-Seber stochastic models for open populations, we estimated annual survival rate, population size, and recruitment between sampling periods for each species. We then explored relationships between these parameters and attributes such as body size, phylogenetic affiliation, foraging guild, and social behavior. Larger birds had comparatively long life-spans and low recruitment, but body size was not associated with population size. After adjusting for effects of body size, we found no association between phylogenetic affiliation and any demographic trait. Ecological attributes, especially foraging guild, were more clearly associated with interspecific variation in all demographic traits. Ant-followers had comparatively long life-spans, but species that participate in flocks did not live longer than solitary species. The allometric associations we observed were consistent with those demonstrated in other studies of vertebrates; thus. these relationships appear to be robust. Our finding that ecological factors were more influential than phylogenetic affiliation contrasts with comparative studies of temperate-zone birds and suggests that the relative importance of environmental vs. historical factors varies geographically.

Brawn, J.D.; Karr, J.R.; Nichols, J.D.

1995-01-01

27

Taxonomy, distribution and biology of lettuce powdery mildew (Golovinomyces cichoracearum sensu stricto)  

UK PubMed Central (United Kingdom)

This paper reviews the taxonomy, biology, importance, host-pathogen interactions and control of lettuce powdery mildew. The main causal agent of this disease, Golovinomyces cichoracearum s.s., is an important powdery mildew pathogen of many members of the family Asteraceae. The pathogen is distributed worldwide and occurs on Lactuca sativa as well as wild Lactuca spp. and related taxa (e.g. Cichorium spp.). Powdery mildew of lettuce can be a major problem in production areas with favourable environmental conditions for disease development (dry, hot weather). The fungus grows ectophytically and appears as white, powdery growth on both the upper and lower sides of leaves. There is rather limited information on the geographic distribution of powdery mildew on wild Lactuca spp. Most L. sativa cultivars have been found to be susceptible. Large variability in virulence was confirmed and existence of different races is supposed. Resistance in L. sativa and some related wild Lactuca spp. is characterized by race-specificity, but the genetic background of resistance is poorly understood. Sources of resistance are known in L. saligna and L. virosa. Lettuce powdery mildew can be effectively controlled by common fungicides (e.g. sulphur, myclobutanil, quinoline, strobilurins, etc.) and protective compounds (e.g. extract of neem oil, Reynoutria sachaliensis extracts). However, fungicide resistance may arise. Non-fungicidal activators of plant systemic acquired resistance (SAR) had no direct effect on the causal agent. Future issues regarding lettuce powdery mildew research are summarized.

Lebeda A; Mieslerová B

2011-06-01

28

Ecology and taxonomy of bacteria attaching to wood surfaces in a tropical harbor.  

UK PubMed Central (United Kingdom)

Water, sediment, and wooden pilings, samples of which were collected from a harbor in Puerto Rico during the course of a long-term study of biofouling of wood treated with creosote and related compounds, were found to support growth of microbial populations, the dominant taxa of which included Hyphomicrobium, Hyphomonas, Pseudomonas, Vibrio, and Bacillus. New wood exposed to the harbor water was rapidly colonized by Hyphomicrobium vulgare. Old pilings in an advanced stage of biodeterioration maintained a diverse bacterial microflora, representatives of which were also found widely distributed in the water column and sediment. Evidence for bacterial species succession was obtained, indicating that microbial interactions are important for attachment to, and subsequent colonization of, wood surfaces in the marine environment.

Austin B; Allen DA; Zachary A; Belas MR; Colwell RR

1979-04-01

29

Forty years of carabid beetle research in Europe – from taxonomy, biology, ecology and population studies to bioindication, habitat assessment and conservation  

Directory of Open Access Journals (Sweden)

Full Text Available ‘Carabidologists do it all’ (Niemelä 1996a) is a phrase with which most European carabidologists are familiar. Indeed, during the last half a century, professional and amateur entomologists have contributed enormously to our understanding of the basic biology of carabid beetles. The success of the field is in no small part due to regular European Carabidologists’ Meetings, which started in 1969 in Wijster, the Netherlands, with the 14th meeting again held in the Netherlands in 2009, celebrating the 40th anniversary of the first meeting and 50 years of long-term research in the Dwingelderveld. This paper offers a subjective summary of some of the major developments in carabidology since the 1960s. Taxonomy of the family Carabidae is now reasonably established, and the application of modern taxonomic tools has brought up several surprises like elsewhere in the animal kingdom. Progress has been made on the ultimate and proximate factors of seasonality and timing of reproduction, which only exceptionally show non-seasonality. Triggers can be linked to evolutionary events and plausibly explained by the “taxon cycle” theory. Fairly little is still known about certain feeding preferences, including granivory and ants, as well as unique life history strategies, such as ectoparasitism and predation on higher taxa. The study of carabids has been instrumental in developing metapopulation theory (even if it was termed differently). Dispersal is one of the areas intensively studied, and results show an intricate interaction between walking and flying as the major mechanisms. The ecological study of carabids is still hampered by some unresolved questions about sampling and data evaluation. It is recognised that knowledge is uneven, especially concerning larvae and species in tropical areas. By their abundance and wide distribution, carabid beetles can be useful in population studies, bioindication, conservation biology and landscape ecology. Indeed, 40 years of carabidological research have provided so much data and insights, that among insects - and arguably most other terrestrial organisms - carabid beetles are one of the most worthwhile model groups for biological studies.

Johan Kotze; Pietro Brandmayr; Achille Casale; Emmanuelle Dauffy-Richard; Wouter Dekoninck; Matti Koivula; Gabor Lovei; Dietrich Mossakowski; Jinze Noordijk; Wilfried Paarmann; Roberto Pizzoloto; Pavel Saska; Axel Schwerk; Jose Serrano; Jan Szyszko; Angela Palomares; Hans Turin; Stephen Venn; Rikjan Vermeulen; Tullia Zetto Brandmayr

2011-01-01

30

Forty years of carabid beetle research in Europe - from taxonomy, biology, ecology and population studies to bioindication, habitat assessment and conservation.  

Science.gov (United States)

'Carabidologists do it all' (Niemelä 1996a) is a phrase with which most European carabidologists are familiar. Indeed, during the last half a century, professional and amateur entomologists have contributed enormously to our understanding of the basic biology of carabid beetles. The success of the field is in no small part due to regular European Carabidologists' Meetings, which started in 1969 in Wijster, the Netherlands, with the 14th meeting again held in the Netherlands in 2009, celebrating the 40th anniversary of the first meeting and 50 years of long-term research in the Dwingelderveld. This paper offers a subjective summary of some of the major developments in carabidology since the 1960s. Taxonomy of the family Carabidae is now reasonably established, and the application of modern taxonomic tools has brought up several surprises like elsewhere in the animal kingdom. Progress has been made on the ultimate and proximate factors of seasonality and timing of reproduction, which only exceptionally show non-seasonality. Triggers can be linked to evolutionary events and plausibly explained by the "taxon cycle" theory. Fairly little is still known about certain feeding preferences, including granivory and ants, as well as unique life history strategies, such as ectoparasitism and predation on higher taxa. The study of carabids has been instrumental in developing metapopulation theory (even if it was termed differently). Dispersal is one of the areas intensively studied, and results show an intricate interaction between walking and flying as the major mechanisms. The ecological study of carabids is still hampered by some unresolved questions about sampling and data evaluation. It is recognised that knowledge is uneven, especially concerning larvae and species in tropical areas. By their abundance and wide distribution, carabid beetles can be useful in population studies, bioindication, conservation biology and landscape ecology. Indeed, 40 years of carabidological research have provided so much data and insights, that among insects - and arguably most other terrestrial organisms - carabid beetles are one of the most worthwhile model groups for biological studies. PMID:21738408

Kotze, D Johan; Brandmayr, Pietro; Casale, Achille; Dauffy-Richard, Emmanuelle; Dekoninck, Wouter; Koivula, Matti J; Lövei, Gábor L; Mossakowski, Dietrich; Noordijk, Jinze; Paarmann, Wilfried; Pizzolotto, Roberto; Saska, Pavel; Schwerk, Axel; Serrano, José; Szyszko, Jan; Taboada, Angela; Turin, Hans; Venn, Stephen; Vermeulen, Rikjan; Zetto, Tullia

2011-05-20

31

Asteroid taxonomy  

International Nuclear Information System (INIS)

The spectral reflectivity of asteroid surfaces over the wavelength range of 0.3 to 1.1 ?m can be used to classify these objects onto several broad groups with similar spectral characteristics. The three most recently developed taxonomies group the asteroids into 9, 11 or 14 different classes, depending on the technique used to perform the analysis. The distribution of the taxonomic classes shows that darker and redder objects become more dominant at larger heliocentric distances, while the rare asteroid types are found more frequently among the small objects of the planet-crossing population

1989-01-01

32

CARRAGENOPHYTAS ECOLOGICAL ASPECTS AND GEOGRAPHICAL DISTRIBUTION  

Directory of Open Access Journals (Sweden)

Full Text Available The carragenophytas species are defined as macro-algae, members of the Phylum Rodophyta, Rodophyceae Class, Florideophycidae Subclass, Gigartinales Order. The most important commercial species at the international level are the Betaphycus, Eucheuma and Kappaphycus genera and at the national level the species belonging to the Gigartina, Mazzaella and Sarcothalia genera. Because of its commercial importance, the Gigartina genus has been the object of investigations such as: Ecology of populations in estuaries and open coast in the North-East Atlantic species; it has been studied by Mathieson and Tveter (1976) in relation with its carragenine quantity and quality. Studies about the response to photoperiods (Guiry, 1984; Guiry et al., 1984) have identified reproductive “windows” suggesting that the explanations for vegetative multiplication are more exclusive each time, different from gametangial or tetra-sporangial production in populations of high latitudes from a generalized European species. Genetic determination of ramification patterns and tolerance limits to temperature has been established for several species (Guiry et al., 1987; Buschmann, 2001). Species cultivation viability in artificial substrates has been evaluated by Mumford y Waaland (1980), and it showed commercial potential. This genus has distribution worldwide in warm and cold seas. However, very few species happen in subtropical regions. The particularly rich species biodiversity centers are California, Japan, New Zealand, Chile y South Africa (Guiry, M.D & Guiry, G.M. 2011).

MARGARITA DEL R. SALAZAR SÁNCHEZ; RAÚL A. SALAZAR SÁNCHEZ

2012-01-01

33

Distribution of trace elements in land plants and botanical taxonomy with special reference to rare earth elements and actinium  

International Nuclear Information System (INIS)

[en] Distribution profiles of trace elements in land plants were studied by neutron activation analysis and radioactivity measurements without activation. Number of botanical samples analyzed were more than three thousand in which more than three hundred botanical species were included. New accumulator plants of Co, Cr, Zn, Cd, rare earth elements, Ac, U, etc., were found. Capabilities of accumulating trace elements can be related to the botanical taxonomy. Discussions are given from view points of inorganic chemistry as well as from botanical physiology

1989-01-01

34

Taxonomy and distribution of aquatic and semiaquatic Heteroptera (Insecta) from Cuba  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Heteroptera es un grupo de insectos que se distribuyen en todo el mundo, viven en ambientes terrestres y acuáticos, en los que tienen un papel ecológico muy importante. Mediante la literatura y colecciones en el campo se estudiaron los Heterópteros acuáticos y semiacuáticos de Cuba, junto con datos sobre la distribución geográfica de las especies, altitud y estaciones de colecta. Se enumeran representantes de 86 especies y morfospecies de los infraórdenes Dipsocor (more) omorpha, Leptopodomorpha, Gerromorpha y Nepomorpha, con un total de 35 géneros y 16 familias. Los datos de distribución muestran una preferencia por los ambientes de aguas lentas o estancadas y áreas de baja altitud. Quince especies se distribuyen en toda la isla; el sector Oriental es el mejor representado, con 53 especies (61.63%), 16 de ellas (18.60%) confinadas a este sector. La similitud biológica más fuerte se encontró entre los sectores oriental y occidental (25%) y la más débil entre los sectores occidental y central (14%). Abstract in english Heteroptera is a worldwide distributed group of insects inhabiting both terrestrial and aquatic habitats and has an important ecological role. A survey of aquatic and semiaquatic Heteroptera from Cuba is provided based on literature reports and field collections. General data on species geographical distribution are given, along with altitude and collection season. Representatives of 86 species and morphospecies of the infraorders Dipsocoromorpha, Leptopodomorpha, Gerromo (more) rpha and Nepomorpha are listed, distributed in 35 genera and 16 families were found. Based on distributional data, a preference for habitats of stagnant water or slow current and lower altitudes is inferred. Fifteen species are distributed throughout the entire island. A higher species diversity was found in the Eastern sector, with 53 species (61.63%), 16 of which (18.60%) are confined to this area. The strongest biological similarity was found between Eastern and Western sectors (25%), and the weakest between Western and Central sectors (14%). Rev. Biol. Trop. 58 (3): 897-907. Epub 2010 September 01.

Naranjo, Carlos; Muñoz Riviaux, Senén; Moreira, Felipe F.F; Correa Court, Ramón

2010-09-01

35

Is there an ecological basis for species abundance distributions?  

UK PubMed Central (United Kingdom)

Community ecologists have attempted to explain species abundance distribution (SAD) shape for more than 80 years, but usually without relating SAD shape explicitly to ecological variables. We explored whether the scale (total assemblage abundance) and shape (assemblage evenness) of avifaunal SADs were related to ecological covariates. We used data on avifaunas, in-site habitat structure and landscape context that were assembled from previous studies; this amounted to 197 transects distributed across 16,000 km(2) of the box-ironbark forests of southeastern Australia. We used Bayesian conditional autoregressive models to link SAD scale and shape to these ecological covariates. Variation in SAD scale was relatable to some ecological covariates, especially to landscape vegetation cover and to tree height. We could not find any relationships between SAD shape and ecological covariates. SAD shape, the core component in SAD theory, may hold little information about how assemblages are governed ecologically and may result from statistical processes, which, if general, would indicate that SAD shape is not useful for distinguishing among theories of assemblage structure.

Yen JD; Thomson JR; Mac Nally R

2013-02-01

36

Ecological distribution of stream macroalgae in different spatial scales using taxonomic and morphological groups  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english We examined the ecological distribution of macroalgal communities in streams using species groups (taxonomic units = algal phyla, and morphological = morphological types) with similar structures and functions instead of the species themselves. The study was conducted from June to July/2007 in two drainage basins located in mid-southern region of Paraná State , Brazil. Evaluations of macroalgal communities took into consideration the following spatial scales: the drainage (more) basin (the Pedras river and Marrecas river basins), shading regime (open and shaded stream segments), mesohabitats (riffles and pools), and microhabitats (sampling units of 0.05m2). A total of 29 taxa (23 subgeneric, one generic, and five vegetative groups) were identified. On these, 12 taxa belong to Chlorophyta, 11 to Cyanobacteria, four to Heterokontophyta, and two to Rhodophyta. The proportions of morphological types were: 24% free filaments, 17.25% mats, tufts, gelatinous colonies, and gelatinous filaments, 7% crusts. In terms of spatial scales, we observed a predominance of Chlorophyta in open stream segments and Cyanobacteria in shaded stream segments, reflecting the loss of competitive advantage of green algae in sites with low energy availability. In the mesohabitats, the morphological types recorded in pools were predominantly poorly adapted to fast currents (free filaments), while those found in riffles (mats, tufts and gelatinous filaments) were highly resistant to fast water flows. As such, the use of species groupings based on algal taxonomy associated with morphological characteristics proved to be useful to understanding the distributions of these organisms in lotic environments.

Krupek, Rogério Antonio; Branco, Ciro Cesar Zanini

2012-01-01

37

Ecological distribution of stream macroalgae in different spatial scales using taxonomic and morphological groups  

Directory of Open Access Journals (Sweden)

Full Text Available We examined the ecological distribution of macroalgal communities in streams using species groups (taxonomic units = algal phyla, and morphological = morphological types) with similar structures and functions instead of the species themselves. The study was conducted from June to July/2007 in two drainage basins located in mid-southern region of Paraná State , Brazil. Evaluations of macroalgal communities took into consideration the following spatial scales: the drainage basin (the Pedras river and Marrecas river basins), shading regime (open and shaded stream segments), mesohabitats (riffles and pools), and microhabitats (sampling units of 0.05m2). A total of 29 taxa (23 subgeneric, one generic, and five vegetative groups) were identified. On these, 12 taxa belong to Chlorophyta, 11 to Cyanobacteria, four to Heterokontophyta, and two to Rhodophyta. The proportions of morphological types were: 24% free filaments, 17.25% mats, tufts, gelatinous colonies, and gelatinous filaments, 7% crusts. In terms of spatial scales, we observed a predominance of Chlorophyta in open stream segments and Cyanobacteria in shaded stream segments, reflecting the loss of competitive advantage of green algae in sites with low energy availability. In the mesohabitats, the morphological types recorded in pools were predominantly poorly adapted to fast currents (free filaments), while those found in riffles (mats, tufts and gelatinous filaments) were highly resistant to fast water flows. As such, the use of species groupings based on algal taxonomy associated with morphological characteristics proved to be useful to understanding the distributions of these organisms in lotic environments.

Rogério Antonio Krupek; Ciro Cesar Zanini Branco

2012-01-01

38

Distribution and ecology of Bulinus truncatus in Khuzestan, Iran*  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The results of a 5-year study on the distribution and ecology of Bulinus truncatus in Khuzestan, south-western Iran, are described. Live snails were found in 4 foci, namely, the main focus, the upper Karun River, the lower Karkheh River, and the Bala Rud watershed; in addition, dead snails were foun...

Chu, K. Y.; Massoud, J.; Arfaa, F.

39

On the challenge of fitting tree size distributions in ecology.  

UK PubMed Central (United Kingdom)

Patterns that resemble strongly skewed size distributions are frequently observed in ecology. A typical example represents tree size distributions of stem diameters. Empirical tests of ecological theories predicting their parameters have been conducted, but the results are difficult to interpret because the statistical methods that are applied to fit such decaying size distributions vary. In addition, binning of field data as well as measurement errors might potentially bias parameter estimates. Here, we compare three different methods for parameter estimation--the common maximum likelihood estimation (MLE) and two modified types of MLE correcting for binning of observations or random measurement errors. We test whether three typical frequency distributions, namely the power-law, negative exponential and Weibull distribution can be precisely identified, and how parameter estimates are biased when observations are additionally either binned or contain measurement error. We show that uncorrected MLE already loses the ability to discern functional form and parameters at relatively small levels of uncertainties. The modified MLE methods that consider such uncertainties (either binning or measurement error) are comparatively much more robust. We conclude that it is important to reduce binning of observations, if possible, and to quantify observation accuracy in empirical studies for fitting strongly skewed size distributions. In general, modified MLE methods that correct binning or measurement errors can be applied to ensure reliable results.

Taubert F; Hartig F; Dobner HJ; Huth A

2013-01-01

40

On the challenge of fitting tree size distributions in ecology.  

Science.gov (United States)

Patterns that resemble strongly skewed size distributions are frequently observed in ecology. A typical example represents tree size distributions of stem diameters. Empirical tests of ecological theories predicting their parameters have been conducted, but the results are difficult to interpret because the statistical methods that are applied to fit such decaying size distributions vary. In addition, binning of field data as well as measurement errors might potentially bias parameter estimates. Here, we compare three different methods for parameter estimation--the common maximum likelihood estimation (MLE) and two modified types of MLE correcting for binning of observations or random measurement errors. We test whether three typical frequency distributions, namely the power-law, negative exponential and Weibull distribution can be precisely identified, and how parameter estimates are biased when observations are additionally either binned or contain measurement error. We show that uncorrected MLE already loses the ability to discern functional form and parameters at relatively small levels of uncertainties. The modified MLE methods that consider such uncertainties (either binning or measurement error) are comparatively much more robust. We conclude that it is important to reduce binning of observations, if possible, and to quantify observation accuracy in empirical studies for fitting strongly skewed size distributions. In general, modified MLE methods that correct binning or measurement errors can be applied to ensure reliable results. PMID:23469137

Taubert, Franziska; Hartig, Florian; Dobner, Hans-Jürgen; Huth, Andreas

2013-02-28

 
 
 
 
41

The scolopendromorph centipedes (Chilopoda, Scolopendromorpha) of Tunisia: taxonomy, distribution and habitats  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present paper provides a review of the composition, distribution and habitat preferences of the scolopendromorph centipedes of Tunisia. Five (sub-)genera and 8 (sub-)species have hitherto been reported from the country, of which two are of uncertain status. After a study of significant amount of...

Nesrine Akkari; Pavel Stoev; John Lewis

42

Chaetognatha of the Namibian upwelling region: taxonomy, distribution and trophic position.  

UK PubMed Central (United Kingdom)

In October 2010, the vertical distribution, biodiversity and maturity stages of Chaetognatha species were investigated at four stations located off Walvis Bay, Namibia. Seventeen species were detected and classified as pelagic, shallow-mesopelagic, deep-mesopelagic and bathypelagic species based upon the weighted mean depth derived from their average vertical distribution. High abundances of Chaetognatha were found in the upper 100 m at all stations of the Walvis Bay transect with a maximum value of 20837 ind. 1000 m(-3) at the outer shelf station near the surface. The community was dominated by species of the Serratodentata group. Furthermore, the distribution of Chaetognatha did not seem to be influenced by low oxygen concentrations. Stable isotope ratios of carbon and nitrogen in Chaetognatha were determined for seven different areas located off northern Namibia. The values of ?(15)N ranged from 6.05 ‰ to 11.39 ‰, while the ?(13)C values varied between -23.89 ‰ and -17.03 ‰. The highest values for ?(15)N were observed at the Walvis Bay shelf break station. The lowest ?(13)C values were found at the Rocky Point offshore station, which was statistically different from all other areas. Stable isotopes of carbon and nitrogen were determined for four taxa (Sagitta minima, Planctonis group, Sagitta enflata, Sagitta decipiens). In this case, the ?(15)N values ranged from 6.17 ‰ to 10.38 ‰, whereas the ?(13)C values varied from -22.70 ‰ to -21.56 ‰. The lowest ?(15)N values were found for S. minima. The C- and N-content revealed maximum C-values for S. decipiens and maximum N-values for the Planctonis group. The C:N ratio of Chaetognatha ranged between 5.25 and 6.20. Overall, Chaetognatha are a diverse group in the pelagic food web of the Benguela Upwelling System and act as competitors of fish larvae and jelly fish by preying on copepods.

Bohata K; Koppelmann R

2013-01-01

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Study on taxonomy and distribution of Ornithocercus in the East China Sea  

UK PubMed Central (United Kingdom)

The samples desccibed in this paper are from the East China Sea taken by R/V Shijian during China-Japan joint project on Kuroshio from 1986-1992. Morphological structures of these species are carefully examined under LM and SEM.It reveals that Ornithocercus possesses five list, namely upper girdle list, low girdle list, right posterior list, left sulcal list and right sulcal list. The distributive pattern of Ornithocercus coinsides well with the hydrological boundary of Kuroshio in all seasons. Thus, they can be served as good indicator for the warm water systems in the East China Sea. Ornithocercus and their symbionts, cyanobacterials, may be beneficial each other in the oligotrophic open water ecosystems. The heterotrophic dinoflagellate may provide the cyanibacterial symbionts with the anaerobic microenvironment necessary for N fixation and in turn, the symbionts can be served as a carbon source such as the functional role of chloroplasts for Ornithocercus.

Lu Douding; Gobel J

2001-01-01

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The scolopendromorph centipedes (Chilopoda, Scolopendromorpha) of Tunisia: taxonomy, distribution and habitats  

Directory of Open Access Journals (Sweden)

Full Text Available The present paper provides a review of the composition, distribution and habitat preferences of the scolopendromorph centipedes of Tunisia. Five (sub-)genera and 8 (sub-)species have hitherto been reported from the country, of which two are of uncertain status. After a study of significant amount of new material collected in the period 2003-2008, 6 species, namely Scolopendra canidens Newport, 1844, S. morsitans Linnaeus, 1758, Cormocephalus gervaisianus (C.L. Koch, 1841), Otostigmus spinicaudus (Newport, 1844), Cryptops punicus Silvestri, 1896 and C. trisulcatus Brölemann, 1902, were found in the country. New illustrations and, where appropriate, brief descriptions of the species are given, along with an identification key for the Tunisian scolopendromorphs. Cryptops anomalans Newport 1844, Scolopendra oraniensis Lucas, 1846 and S. cingulata Latreille, 1829 are excluded from the country’s list since all previous records are most likely based on misidentifications. Cryptops trisulcatus and C. punicus are recorded for the first time from Tunisia and Libya, respectively. The taxonomic position of C. punicus is discussed and the species is transferred from the subgenus Trigonocryptops to Cryptops. Scolopendra morsitans scopoliana is synonymised under S. morsitans. S. canidens, O. spinicaudus and C. punicus are well adapted to arid and semidesert biotopes and have much wider ranges compared to the other three species which are restricted to the northern, more humid parts of the country. S. canidens is the only myriapod in Tunisia found in a pure sandy desert.

Nesrine Akkari; Pavel Stoev; John Lewis

2008-01-01

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Brazilian species of Onychophora with notes on their taxonomy and distribution  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A revision of the currently known distribution of Onychophora (velvet worms) in Brazil is presented. Twenty-four morphospecies (half of them undescribed) belonging to four genera of the Peripatidae (Peripatus Guilding, 1826, Epiperipatus Clark, 1913, Macroperipatus Clark, 1913 and Oroperipatus Cockerell, 1908) are recorded. This high number of "unidentified" morphospecies is due to three major reasons: the poor quality of the characters used in species-level identificatio (more) n, the inadequate specimen conservation in ethanol, and, in most cases, the lack of additional specimens for analysis of intra- and inter-specific variation. The morphological characters currently used to separate Peripatidae species present a large degree of variation and may not be sufficient to allow accurate identification. There are records of these animals from 16 states, located in four political regions of the country (North, Center-West, Northeast and Southeast). Oroperipatus balzani is recorded for the first time from Brazil. The southernmost record for Onychophora is Itacuruçá island, Mangaratiba, Rio de Janeiro State (E. edwardsii) and the northernmost is Vila Tepequém, Amajari, Roraima State (Epiperipatus sp. 4). Considering the large territorial area of Brazil and the paucity of localities where Onychophora have been collected, we may expect a total diversity of these animals much larger than the currently known one.

Sampaio-Costa, Cristiano; Chagas-Junior, Amazonas; Baptista, Renner L. C.

2009-09-01

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Taxonomy and distribution of Formica dusmeti Emery, 1909 and of F. frontalis Santschi, 1919 (Hymenoptera, Formicidae)  

Directory of Open Access Journals (Sweden)

Full Text Available In the present work, we indicate the distribution of and taxonomic differences between Formica dusmeti and Formica frontalis (stat. n.). Morphological differences include a total absence of hairs in F. dusmeti as opposed to uniformly scattered hairs in F. frontalis. These two species have similar coloration and hairless scapes and eyes. In addition, we describe the male and female of F. frontalis, a species that was considered until now to be a subspecies of F. truncorum. We consider F. frontalis to be a separate species from F. truncorum, differentiated by a lack of hairs on the eyes, scapes and genae in the workers of the former. The males of F. frontalis are distinguished from F. truncorum by hairless eyes and scapes. Finally, a key has been formulated for the workers in the rufa, sanguinea and exsecta groups of the genus Formica in the Iberian Peninsula.En este trabajo se señalan las diferencias existentes entre Formica dusmeti y Formica frontalis (stat. n.) y su distribución. Estas diferencias estriban en la ausencia total de quetas en F. dusmeti y la presencia de numerosas quetas uniformemente distribuidas en F. frontalis. Estas dos especies presentan en común la coloración y la ausencia de quetas en escapo y ojos. Describimos el macho y la hembra de F. frontalis, especie que era considerada hasta ahora como subespecie de F. truncorum. En este artículo la elevamos a especie y la diferenciamos de F. truncorum por la ausencia de quetas en los ojos, escapos y genas de las obreras. Los machos se diferencian también por la ausencia de quetas en ojos y escapos. Por último se realiza una clave para las obreras de la Península Ibérica de las especies de Formica de los grupos rufa, sanguinea y exsecta.

Tinaut, A.; Martínez-Ibáñez, Mª. D.

1998-01-01

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The genus Elaphomyces and its ecological distribution in Xizang  

UK PubMed Central (United Kingdom)

Three species and a varities of Elaphomyces in Xizang, China are reported. Among them, E. granulatus var. granulatus, and E. muricatus were previously reported from China, E. granulatus var. asperulus is a new record to China, and E. tuberculatus, with specially large warts on fruitbody surface in the group of E. granulatus, and no marbled peridium, is described as a new species (HXZE 1230, Type, deposited in Xizang Institute of Plateau Ecology). Variabilities between or within species are discussed and some regularities are discovered on the basis of study of the Tibetan collections. These species forming ectomycorrhizas are associated with Abies, Picea and Quercus, but no specimen has been collected in the pine forests, which distributed widely in Xizang.

Xu Asheng

1999-01-01

48

Nacellidae limpets of the southern end of South America: taxonomy and distribution/ Lapas Nacellidae del extremo sur de Sudamérica: taxonomía y distribución  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Los moluscos del extremo sur de Sudamérica son desde un punto de vista taxonómico moderadamente bien conocidos. Sin embargo, la literatura está dispersa, hay poca información sobre sus hábitat y son muy pocos los registros distribucionales, particularmente en el área de los fiordos comprendidos entre la Isla de Chiloé (42° S) y Tierra del Fuego (55° S). Aunque se sabe bastante acerca de la biología y ecología de algunas especies de Nacellidae, la taxonomía del (more) grupo ha sido relativamente poco estudiada, particularmente en áreas remotas del planeta, como es el caso de los fiordos chilenos. El interés del presente estudio ha sido clarificar el estatus nomenclatural y describir las características morfológicas y distribuciones de los Nacellidae chilenos. En particular, se plantearon los siguientes objetivos: (i) clarificar la identidad de las especies descritas, (ii) descripción de detalles morfológicos, destacando los caracteres diagnósticos de cada especie, y (iii) delimitación y discusión de sus rangos geográficos. El análisis de los Nacellidae de los fiordos chilenos ha permitido el reconocimiento de una especie de Nacella (Nacella) y siete de N. (Patinigera), cuyas principales diferencias a nivel de especie radican en la concha (forma, espesor y color) y en la morfología de la dentición radular. El género Nacella y su subgénero Patinigera son habitantes exclusivos de aguas antárticas y subantárticas. Estos organismos son lapas de aguas frías fundamentalmente subantárticas, pero que también se extienden hacia la Antártica por el área del Arco de Escocia, y hacia el norte a lo largo de la costa chilena, hasta el área de Valparaíso a 33° S (N. (P.) clypeater). Aparentemente este género tiene su centro de distribución en la Provincia magallánica en el sur de Sudamérica, correspondiendo a un área de elevada diversidad de especies (N. (N.) mytilina, N. (P.) chiloensis, N. (P.) deaurata, N. (P.) delicatissima, N. (P.) flammea, N. (P.) magellanica, N. (P.) venosa), donde las especies tienden a dispersarse hacia el este, con un transporte larval probablemente facilitado por la corriente de deriva del oeste que opera fuertemente en la zona subantártica Abstract in english Taxonomically, the Mollusca of the southern end of South America are moderately well known, but the literature is scattered, there is little information on their habitats, and distributional records are scarce for the Chilean archipelago lying between Chiloé Island (42° S) and Tierra del Fuego (55° S). Although much is known about the biology and ecology of of some species of Nacellidae, the taxonomy of the group have been partially neglected, particularly in remote ar (more) eas of the world such as the Chilean fjords. Therefore, this study aims to clarify the nomenclatural status, and establish the morphological characteristics and distribution of the Chilean Nacellidae. Especially, the following three objectives are pursued: (i) to clarify the correct identity of existing species; (ii) to describe of morphological details, highlighting the clear diagnostic characters of each species, and (iii) to delimitate and discuss their geographical range in Chile. The examination of the Nacellidae of the Chilean fiords has resulted in the recognition of one species of Nacella (Nacella) and seven species of Nacella (Patinigera), wherein the principal specific differences are in the shell (shape, thickness and color) and in radular teeth morphology. The genus Nacella and its subgenus Patinigera are cold-water limpets, and are exclusively inhabitants of Subantarctic and Antarctic waters. The greater part of their range being subantarctic, but extending to the Antarctic by way of the Scotia Arc, and also ranging northward up the Chilean coast to at least Valparaiso at 33° S (only N. (P.) clypeater). They apparently have their centre of distribution in the Magellanic Province of southern South America, corresponding to an area with a high degree of diversification (N. (N.) mytilina

VALDOVINOS, CLAUDIO; RÜTH, MAXIMILLIAN

2005-09-01

49

Nacellidae limpets of the southern end of South America: taxonomy and distribution Lapas Nacellidae del extremo sur de Sudamérica: taxonomía y distribución  

Directory of Open Access Journals (Sweden)

Full Text Available Taxonomically, the Mollusca of the southern end of South America are moderately well known, but the literature is scattered, there is little information on their habitats, and distributional records are scarce for the Chilean archipelago lying between Chiloé Island (42° S) and Tierra del Fuego (55° S). Although much is known about the biology and ecology of of some species of Nacellidae, the taxonomy of the group have been partially neglected, particularly in remote areas of the world such as the Chilean fjords. Therefore, this study aims to clarify the nomenclatural status, and establish the morphological characteristics and distribution of the Chilean Nacellidae. Especially, the following three objectives are pursued: (i) to clarify the correct identity of existing species; (ii) to describe of morphological details, highlighting the clear diagnostic characters of each species, and (iii) to delimitate and discuss their geographical range in Chile. The examination of the Nacellidae of the Chilean fiords has resulted in the recognition of one species of Nacella (Nacella) and seven species of Nacella (Patinigera), wherein the principal specific differences are in the shell (shape, thickness and color) and in radular teeth morphology. The genus Nacella and its subgenus Patinigera are cold-water limpets, and are exclusively inhabitants of Subantarctic and Antarctic waters. The greater part of their range being subantarctic, but extending to the Antarctic by way of the Scotia Arc, and also ranging northward up the Chilean coast to at least Valparaiso at 33° S (only N. (P.) clypeater). They apparently have their centre of distribution in the Magellanic Province of southern South America, corresponding to an area with a high degree of diversification (N. (N.) mytilina, N. (P.) chiloensis, N. (P.) deaurata, N. (P.) delicatissima, N. (P.) flammea, N. (P.) magellanica, N. (P.) venosa), wherefrom the species tends to spread eastward, with a larval transport probably assisted to a considerable extent by the prevailing West Wind Drift which strongly operates in the Subantarctic ZoneLos moluscos del extremo sur de Sudamérica son desde un punto de vista taxonómico moderadamente bien conocidos. Sin embargo, la literatura está dispersa, hay poca información sobre sus hábitat y son muy pocos los registros distribucionales, particularmente en el área de los fiordos comprendidos entre la Isla de Chiloé (42° S) y Tierra del Fuego (55° S). Aunque se sabe bastante acerca de la biología y ecología de algunas especies de Nacellidae, la taxonomía del grupo ha sido relativamente poco estudiada, particularmente en áreas remotas del planeta, como es el caso de los fiordos chilenos. El interés del presente estudio ha sido clarificar el estatus nomenclatural y describir las características morfológicas y distribuciones de los Nacellidae chilenos. En particular, se plantearon los siguientes objetivos: (i) clarificar la identidad de las especies descritas, (ii) descripción de detalles morfológicos, destacando los caracteres diagnósticos de cada especie, y (iii) delimitación y discusión de sus rangos geográficos. El análisis de los Nacellidae de los fiordos chilenos ha permitido el reconocimiento de una especie de Nacella (Nacella) y siete de N. (Patinigera), cuyas principales diferencias a nivel de especie radican en la concha (forma, espesor y color) y en la morfología de la dentición radular. El género Nacella y su subgénero Patinigera son habitantes exclusivos de aguas antárticas y subantárticas. Estos organismos son lapas de aguas frías fundamentalmente subantárticas, pero que también se extienden hacia la Antártica por el área del Arco de Escocia, y hacia el norte a lo largo de la costa chilena, hasta el área de Valparaíso a 33° S (N. (P.) clypeater). Aparentemente este género tiene su centro de distribución en la Provincia magallánica en el sur de Sudamérica, correspondiendo a un área de elevada diversidad de especies (N. (N.) mytilina, N. (P.) chiloensis, N. (P.) deaurata, N. (P.)

CLAUDIO VALDOVINOS; MAXIMILLIAN RÜTH

2005-01-01

50

Uses and Requirements of Ecological Niche Models and Related Distributional Models  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract.—Modeling approaches that relate known occurrences of species to landscape features to discover ecological properties and predict geographic occurrences have seen extensive recent application in ecology, systematics, and conservation. A key component in this process is estimation or characterization of species’ distributions in ecological space, which can then be useful in understanding their potential distributions in geographic space. Hence, this process is often termed ecological niche modeling or (less boldly) species distribution modeling. Applications of this approach vary widely in their aims, products, and requirements; this variety is reviewed herein, examples are provided, and differences in data needs and possible interpretations are discussed.

A. Townsend Peterson

2006-01-01

51

Ecology Drives the Worldwide Distribution of Human Diseases  

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Full Text Available Identifying the factors underlying the origin and maintenance of the latitudinal diversity gradient is a central problem in ecology, but no consensus has emerged on which processes might generate this broad pattern. Interestingly, the vast majority of studies exploring the gradient have focused on free-living organisms, ignoring parasitic and infectious disease (PID) species. Here, we address the influence of environmental factors on the biological diversity of human pathogens and their global spatial organization. Using generalized linear multivariate models and Monte Carlo simulations, we conducted a series of comparative analyses to test the hypothesis that human PIDs exhibit the same global patterns of distribution as other taxonomic groups. We found a significant negative relationship between latitude and PID species richness, and a nested spatial organization, i.e., the accumulation of PID species with latitude, over large spatial scales. Additionally, our results show that climatic factors are of primary importance in explaining the link between latitude and the spatial pattern of human pathogens. Based on our findings, we propose that the global latitudinal species diversity gradient might be generated in large part by biotic interactions, providing strong support for the idea that current estimates of species diversity are substantially underestimated. When parasites and pathogens are included, estimates of total species diversity may increase by more than an order of magnitude.

Guernier Vanina; Hochberg Michael E; Guégan Jean-François

2004-01-01

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Interpretation of Models of Fundamental Ecological Niches and Species’ Distributional Areas  

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Full Text Available Ecological niche modeling?that is, estimation of the dimensions of fundamental ecological niches of species?to predict their geographic distributions is increasingly being employed in systematics, ecology, conservation, public health, etc. This technique is often (of necessity) based on data comprising records of presences only. In recent years, many modeling approaches have been devised to estimate these interrelated expressions of a species’ ecology, distributional biology, and evolutionary history?nevertheless, in many cases, a formal basis in ecological and evolutionary theory has been lacking. In this paper, we outline such a formal basis for the suite of techniques that can be termed ‘ecological niche modeling,’ analyze example situations that can be modeled using these techniques, and clarify the interpretation of results.

Jorge Soberon; A. Townsend Peterson

2005-01-01

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INVASIVE SPECIES: PREDICTING GEOGRAPHIC DISTRIBUTIONS USING ECOLOGICAL NICHE MODELING  

Science.gov (United States)

Present approaches to species invasions are reactive in nature. This scenario results in management that perpetually lags behind the most recent invasion and makes control much more difficult. In contrast, spatially explicit ecological niche modeling provides an effective solut...

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Benefits from ecological study methods to taxonomy of enchytraeids in southern Mata Atlântica/ Benefícios de métodos de estudos ecológicos para a taxonomia de enquitreídeos no sul da Mata Atlântica  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi determinar como a taxonomia beneficia-se de métodos quantitativos e de amostragem ecológicos nos estudos dos enquitreídeos. Enquitreídeos (pequenos parentes das minhocas) foram coletados em diferentes fases de regeneração da Mata Atlântica no Estado do Paraná, Brasil. Foram combinadas as pesquisas ecológica e taxonômica, pois os enquitreídeos são pouco estudados e difíceis de identificar, e muitas espécies novas eram esperadas. (more) O grande número de espécimes coletados permitiu testar diagnoses de espécies por meio da investigação das amplitudes de variações de caracteres em uma série mais ampla de espécimes. Diagnoses de espécies simplificadas, adaptadas às condições locais do ambiente, foram desenvolvidas, o que permitiu a identificação de todos os exemplares, incluindo juvenis. Caracteres-chave e estados de caracteres foram formulados para três gêneros: Achaeta, Hemienchytraeus e Guaranidrilus. Entre várias espécies novas, uma espécie rara, possível remanescente da fauna autóctone da floresta, foi encontrada e descrita. Abstract in english The objective of this work was to determine how taxonomy benefited from the ecological quantitative and site-based sampling methods in enchytraeids studies. Enchytraeids (small relatives of earthworms) were sampled in different phases of rain forest regeneration in the southern Mata Atlântica in Paraná, Brazil. The research combined ecological and taxonomic work, because enchytraeids are poorly studied and difficult to identify, and many new species were expected. The p (more) rovision of large numbers of specimens enabled the test of species diagnoses by investigating the ranges of character variations in a larger series of specimens. Simplified species diagnoses adapted to the local conditions that allowed the identification of all specimens, juveniles included, were developed. Key characters and character states are presented for the three genera: Achaeta, Hemienchytraeus and Guaranidrilus. Among several new species, a rare species, possibly a remnant of the autochthonous forest fauna, was found and described.

Schmelz, Rüdiger Maria; Peña, Rut Maria Collado de la; Römbke, Jörg

2009-08-01

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Distribution of Lutra maculicollis in Rwanda : ecological constraints  

Directory of Open Access Journals (Sweden)

Full Text Available The study of 10 rwandese lakes, where there are still quite important populations of Lutra maculicollis, has pointed out a few characteristics of the habitat favorable to the survival of these populations. The ecological constraints for the survival of these populations are: the abundance of small fishes, the continuity of the lake side vegetation, the absence of crocodiles and pollution by pesticides, and the low level of predation by man.

Lejeune A.; Frank A.

1990-01-01

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Ecology  

International Nuclear Information System (INIS)

The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP)

1978-01-01

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Measurement of ecological niche of Quercus aliena and Q. serrata under environmental factors treatments and its meaning to ecological distribution  

Directory of Open Access Journals (Sweden)

Full Text Available Quercus aliena and Q. serrata are both occur as natural vegetation alongside natural freshwater bodies of the southernKorea Peninsula. Q. serrata dominates over Q. aliena as secondary forest vegetation in the present day. In order to explainthese natural distributional traits of the oak species, we conducted some experiments with oak seedlings which treatedwith major important environmental resources, including light, moisture and nutrients, under controlled conditions.We then measured the ecological niche breadths and overlap from 15 eco-morphological characteristics. The ecologicalniche breadth of Q. aliena and Q. serrata were higher in terms of the nutrient factor applied, but was lower terms of light.The niche breadth of Q. serrata was wider than that of Q. aliena in light and moisture exposure. On the other hand, theniche breadth of Q. aliena was similar with that of Q. serrata in terms of the nutrient factor applied. These results implythat Q. serrata has a broader ecological distribution in over a wider variety of light and moisture environments than thatof Q. alien. Ecological niche overlap between two oak species was the widest in terms of the light treatment factor applied,and narrowest in terms of moisture. This response pattern was also verified by cluster and principle componentanalysis. These results suggest competitive interactions between Q. serrata and Q. aliena seedlings may be higher for lightresources than moisture or nutrient resources, and that Q. serrata is more shade tolerant than Q. aliena.

Seung-Hyuk Lee; Young-Han You*

2012-01-01

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[Spatial distribution of leptospirosis in Rio Grande do Sul, Brazil: recovering the ecology of ecological studies].  

UK PubMed Central (United Kingdom)

Leptospirosis is an endemic disease in the State of Rio Grande do Sul, Brazil, and presents a broad diversity of exposure routes, reservoirs, etiological agents, and clinical features. The main objective of this work is to identify transmission areas and possible ecological components of leptospirosis transmission. This was accomplished through the aggregation of epidemiological data into spatial units that represent the State's socio-environmental diversity. The 1,274 confirmed leptospirosis cases that occurred in 2001 were georeferenced in the counties of residence. The county maps were overlaid on environmental units characterizing land use, altitude, and river basins. Incidence rates for each environmental class were calculated, along with their statistical significance, through GIS aggregation operations. The highest incidence rates were verified in coastal sedimentary areas with low altitude and predominantly agricultural land use. In these areas, most of the cases were associated with irrigated farming. The results suggest the existence of favorable ecological characteristics for leptospirosis transmission in places involving proliferation of peri-domiciliary rodents and intensive agricultural production. The article discusses the effects of data aggregation into environmental units, as well as strategies to control the endemic in the State.

Barcellos C; Lammerhirt CB; de Almeida MA; dos Santos E

2003-09-01

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Review: Ecological distribution of Dipterocarpaceae species in Indonesia  

Directory of Open Access Journals (Sweden)

Full Text Available Dipterocarpaceae is one of the biggest family with >500 species in the world, and most of dipterocarps population are grown in Indonesia which have high economical value of wood. One of the most important value from dipterocarps species is high on endemicities; there are up to 128 species (53.78%) from 238 dipterocarps species in Indonesia. Distribution of dipterocarps species would be affected by some factors especially edaphic, climate, and altitude. In Indonesia the dipterocarps species distribution could be shown from islands groups, number of species and forest types. Based on the observation of herbarium collection in Herbarium Bogoriense the distribution of the most dipterocarps species was in the altitude of 0-500 m and 500-1000 m on the dipterocarps forest type. Kalimantan and Sumatra were the two bigger islands with have the dipterocarps species distributed relatively high on population and species.

PURWANINGSIH

2004-01-01

60

Taxonomy and environmental policy.  

UK PubMed Central (United Kingdom)

In 1992, with the United Nations Conference on Environment and Development in Rio de Janeiro and the subsequent Convention on Biological Diversity (CBD), the world changed for the science of taxonomy. Many taxonomists appear not to have noticed this change, but it has significantly altered the political climate in which taxonomic research is undertaken. By the late 1990s it was clear that effective implementation of the CBD needed the participation of and funding for the taxonomic community. In this paper, I chart the rise of the Global Taxonomy Initiative (GTI), review some of its goals and explore how it interacts with the CBD. The interactions of the GTI with the Global Environment Facility, a potential funding body, are explored, as are the possible synergies between the GTI and the many other global initiatives linking to taxonomy. Finally, I explore some of the challenges ahead as taxonomy begins to take a front seat in the implementation of environmental policy on the world stage.

Samper C

2004-04-01

 
 
 
 
61

Distribution and ecology of the stoneflies (Plecoptera) of Flanders (Belgium)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on a literature survey and the identification of all available collection material from Flanders, a checklist is presented, distribution maps are plotted and the relationship between the occurrence of the different species and water characteristics is analysed. Of the sixteen stonefly species ...

Lock, Koen; Goethals, Peter

62

Distribution and ecology of the mayflies (Ephemeroptera) of Flanders (Belgium)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A literature survey and the identification of all available collection material resulted in a checklist and distribution maps for the mayflies occurring in Flanders. In addition, the relationship between the occurrence of mayflies and water characteristics was analysed. Of the 32 species that have b...

Lock, Koen; Goethals, Peter

63

The taxonomy of telemedicine.  

UK PubMed Central (United Kingdom)

The purpose of this article is to present a taxonomy for telemedicine. The field has markedly grown, with an increasing number of applications, a variety of technologies, and newly introduced terminology. A taxonomy would serve to bring conceptual clarity to this burgeoning set of alternatives to in-person healthcare delivery. The article starts with a brief discussion of the importance of taxonomy as an information management strategy to improve knowledge sharing, facilitate research and policy initiatives, and provide some guidance for the orderly development of telemedicine. We provide a conceptual context for the proliferation of related concepts, such as telehealth, e-health, and m-health, as well as a classification of the content of these concepts. Our main concern is to develop an explicit taxonomy of telemedicine and to demonstrate how it can be used to provide definitive information about the true effects of telemedicine in terms of cost, quality, and access. Taxonomy development and refinement is an iterative process. If this initial attempt at classification proves useful, subject matter experts could enhance the development and proliferation of telemedicine by testing, revising, and verifying this taxonomy.

Bashshur R; Shannon G; Krupinski E; Grigsby J

2011-07-01

64

Characteristics of plants distribution in botanical gardens outside the ecological optimum ??????????? ??????????????? ???????? ? ?????????? ???????????? ????? ?? ????????? ?????????????? ????????  

Directory of Open Access Journals (Sweden)

Full Text Available This article discusses the results of the botanical gardens activity in the introduction and acclimatization of plants appearing: in the distribution of species beyond their natural ecological optimum, in the creation of collections of closely related species capable to spontaneous hybridization, in the formation of sources of invasive species. The role of botanic gardens as anthropogenic centers of evolution and distribution of plants is emphasized.? ?????? ?????? ??????????????? ?????????? ???????????? ???????????? ????? ? ??????? ??????????? ? ?????????????? ????????, ?????????????: ? ??????????????? ????? ?? ??????? ?? ????????????? ?????????????? ????????; ? ???????? ????????? ????????????????? ?????????????????????? ????? ? ??????; ? ???????????? ?????????? ??????????? ?????. ?????????????? ???????? ???????????? ????? ??? ????????????? ??????? ??????????????? ? ???????? ????????.

Prokhorov Alexey Anatolievich; Karpun Yuriy Nikolaevich

2012-01-01

65

Distribution, ecology, and immunosuppressive properties of Tricholoma populinum (Basidiomycetes).  

UK PubMed Central (United Kingdom)

Tricholoma populinum is widely distributed in Europe and North America. In the GDR 110 localities have been recorded, ranging from sea level to 470 m s.m. It is associated with many Populus spp. on acidic and neutral ground; its frequency has locally increased by recultivation of slap-dumps and waste land with poplars. Maximum of fructification is in the first decade of October. Investigations, stimulated by empiric observations on immunosuppressive effects of the mushroom in allergic diseases of man, lead to isolation of ergosterol peroxide as one substance responsible for these effects.

Kreisel H; Lindequist U; Horak M

1990-01-01

66

Distribution, ecology, and immunosuppressive properties of Tricholoma populinum (Basidiomycetes).  

Science.gov (United States)

Tricholoma populinum is widely distributed in Europe and North America. In the GDR 110 localities have been recorded, ranging from sea level to 470 m s.m. It is associated with many Populus spp. on acidic and neutral ground; its frequency has locally increased by recultivation of slap-dumps and waste land with poplars. Maximum of fructification is in the first decade of October. Investigations, stimulated by empiric observations on immunosuppressive effects of the mushroom in allergic diseases of man, lead to isolation of ergosterol peroxide as one substance responsible for these effects. PMID:2220166

Kreisel, H; Lindequist, U; Horak, M

1990-01-01

67

Chonecolea doellingeri (Chonecoleaceae, Hepaticae), taxonomia e distribuição geográfica no Brasil Chonecolea doellingeri (Chonecoleaceae, Hepaticae), taxonomy and geographical distribution in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Chonecolea doellingeri (Nees) Grolle é uma espécie urbanizada que cresce, preferencialmente, sobre estipe de palmeira ou outras árvores. Sua distribuição geográfica foi ampliada para o estado do Mato Grosso do Sul e, também, para municípios de outros estados já referidos. Algumas associações da espécie com outras briófitas são apresentadas. Dados palinológicos, baseados em observações sob microscopia de luz (ML) e microscopia eletrônica de varredura (MEV), também estão incluídos no trabalho.Chonecolea doellingeri (Nees) Grolle is an urbanized species that grows preferentially on palm-tree trunks and other trees. Its geographical distribution was extended to the state of Mato Grosso do Sul and, also, to cities of other aforementioned states. Some associations of these species with other bryophytes are presented. Palynological data, based on observations under light microscopy (LM) and scanning electron microscopy (SEM), are also included.

Olga Yano; Andréa Pereira Luizi-Ponzo

2006-01-01

68

Chonecolea doellingeri (Chonecoleaceae, Hepaticae), taxonomia e distribuição geográfica no Brasil/ Chonecolea doellingeri (Chonecoleaceae, Hepaticae), taxonomy and geographical distribution in Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Chonecolea doellingeri (Nees) Grolle é uma espécie urbanizada que cresce, preferencialmente, sobre estipe de palmeira ou outras árvores. Sua distribuição geográfica foi ampliada para o estado do Mato Grosso do Sul e, também, para municípios de outros estados já referidos. Algumas associações da espécie com outras briófitas são apresentadas. Dados palinológicos, baseados em observações sob microscopia de luz (ML) e microscopia eletrônica de varredura (MEV), também estão incluídos no trabalho. Abstract in english Chonecolea doellingeri (Nees) Grolle is an urbanized species that grows preferentially on palm-tree trunks and other trees. Its geographical distribution was extended to the state of Mato Grosso do Sul and, also, to cities of other aforementioned states. Some associations of these species with other bryophytes are presented. Palynological data, based on observations under light microscopy (LM) and scanning electron microscopy (SEM), are also included.

Yano, Olga; Luizi-Ponzo, Andréa Pereira

2006-12-01

69

TAXONOMÍA Y DISTRIBUCIÓN DE HILDENBRANDIA ANGOLENSIS (HILDENBRANDIALES: RHODOPHYTA) EN COLOMBIA Taxonomy and distribution of Hildenbrandia angolensis (Hildenbrandiales: Rhodophyta) in Colombia  

Directory of Open Access Journals (Sweden)

Full Text Available Este estudio es el primer registro para Colombia del género Hildenbrandia, representando el primer hallazgo de Rhodophyta dulceacuícola. Se incluye la descripción detallada de los caracteres morfométricos, así como la distribución ambiental de las poblaciones recolectadas en tres localidades del departamento de Santander. Se concluye que la especie corresponde a la circunscripción de Hildenbrandia angolensis; caracterizada por su diámetro celular pequeño (?= 4.8 ?m) y de distribución tropical a subtropical. Se documentaron propágulos vegetativos en una sola población. H. angolensis se presentó en ríos cercanos a zonas de cascada, con temperatura de 16- 18 ºC, pH de neutral a ligeramente alcalino (6.9-7.6), alto contenido de iones (272-1174 ?S cm-1), velocidad de corriente muy alta ( 140 cm s-1) y sitios sombreados con poca profundidad (This study is the first report for Colombia of the genus Hildenbrandia, representing the first record of a freshwater Rhodophyta. It is includes the detailed description of the morfometrics characters, as well as the environmental distribution of the populations collected from three localities of the department of Santander. It is concluded that the species fit within Hildenbrandia angolensis circumscription; it is characterized by it is small cell diameter (?= 4.8 ?m) and of tropical or subtropical distribution. Vegetatives propagules were reported in one single population. H. angolensis occurred in rivers near to cascade zones, with temperature of 16- 18 ºC, pH circumneutral to slightly alkaline (6.9-7.6), high ion content (272-1174 ?S cm-1), high current velocity ( 140 cm s-1) and shallow waters (< 60 cm); algal cover of this species on the rock ranged from 3.2 to 4.1 m2. H. angolensis is reported in upper streams basins of the Oro and Frio streams, in dry forest to very humid low montane belonging to Piedecuesta and Floridablanca municipalities ( Santander, Colombia ).

EDGAR J. RINCÓN-B.; LUIS E. PINZÓN-Q.; HELBER BERMÚDEZ-A.; HUMBERTO E. GARCÍA-P.

2006-01-01

70

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

DEFF Research Database (Denmark)

Background Plague is a rapidly progressing, serious illness in humans that is likely to be fatal if not treated. It remains a public health threat, especially in sub-Saharan Africa. In spite of plague's highly focal nature, a thorough ecological understanding of the general distribution pattern of plague across sub-Saharan Africa has not been established to date. In this study, we used human plague data from sub-Saharan Africa for 1970-2007 in an ecological niche modeling framework to explore the potential geographic distribution of plague and its ecological requirements across Africa. Results We predict a broad potential distributional area of plague occurrences across sub-Saharan Africa. General tests of model's transferability suggest that our model can anticipate the potential distribution of plague occurrences in Madagascar and northern Africa. However, generality and predictive ability tests using regional subsets of occurrence points demonstrate the models to be unable to predict independent occurrence points outside the training region accurately. Visualizations show plague to occur in diverse landscapes under wide ranges of environmental conditions. Conclusion We conclude that the typical focality of plague, observed in sub-Saharan Africa, is not related to fragmented and insular environmental conditions manifested at a coarse continental scale. However, our approach provides a foundation for testing hypotheses concerning focal distribution areas of plague and their links with historical and environmental factors.

Neerinckx, Simon B; Peterson, Andrew T

2008-01-01

71

Society's nature: Ecological economics and the combined challenge of environment and distribution  

DEFF Research Database (Denmark)

The paper introduces the emerging field of ecological economics and evaluates its potential for addressing some of the concerns within development studies. It takes as its point of departure the study of the relationship between nature and society that emerged in the wake of the environmental discourse in the 1960s. In the first section, a new perspective in the study of the interaction between society and nature is briefly outlined. Thereafter, the field of ecological economics is discussed as a specific example of this new perspective, followed by its potential link to the development debate, in particular the combination of the environmental and distributional issues and the challenges therein. Finally, the paper reflects on the persuasive potential of ecological economics in relation to politics.

RØpke, Inge

2010-01-01

72

Ecology and distribution of Armillaria species in Norway  

UK PubMed Central (United Kingdom)

The occurence of Armillaria species was assessed in Norway, enabling the northern-most distribution of this genus to be determined in Europe. Four Armillaria species were found in Norway. Armillaria borealis was the most common species occurring on woody vegetation to the permafrost zone (ca. 69°N). Armillaria cepistipes was present in southern and central Norway, but was not found further than 66°N. Armillaria solidipes and Armillaria gallica were rare, found at only one locality each; 59°40? and 59°32?, respectively. Armillaria species were found on 14 hosts, but there was no significant difference between occurrence of A. borealis and A. cepistipes on declining and dead trees. Phylogenetic analyses separated each species into separate clades. All isolates of A. borealis, except one, and most isolates of A. solidipes were in separate clades. However, a subclade within the A. borealis clade was formed of two A. ostoyae and one A. borealis isolates. Two small A. cepistipes genets were found in a declining oak stand.

Ke?a N; Solheim H

2011-04-01

73

The integrative future of taxonomy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Taxonomy is the biological discipline that identifies, describes, classifies and names extant and extinct species and other taxa. Nowadays, species taxonomy is confronted with the challenge to fully incorporate new theory, methods and data from disciplines that s...

Padial José M; Miralles Aurélien; De la Riva Ignacio; Vences Miguel

74

Distribution of natural uranium in Jiuquan ecological environment  

International Nuclear Information System (INIS)

The concentration of natural uranium in soil, forage grass, ox, sheep and camel at Jiuquan area was determined, and the data were analyzed. Its natural distribution under equilibrium and the transfer from the soil to the forage grass then to the animal body were studied. The results show that the uranium concentration in soil was decreasing from 3.09mg/kg to 2.36 mg/kg (corresponding to the surface to 30 cm), then increasing to 2.82mg/kg (corresponding to 100 cm), so the lowest was at the depth of 30 cm. The descending order of concentration in eight kind of forage grasess is Chenopodium album L., Triticum Sativum Lam, Agropyron cristatum(L.) Gaertu, Hordeum vulgare var nudum (Ard.) Hook, Avenasativa L., Sphaerophysa salsula(Pall.) DC, Medicago sativa L. and Phragmites communis Trin, i.e. from the highest 1.48 x 10-3mg/kg to the lowest 0.051 x 10-3mg/kg. The U concentration in mutton was (0.48 ? 1.86) x 10-6mg/kg and the average was 0.89 x 10-6mg/kg, in sheep bone was (3.60 ? 16.20) x 10-6mg/kg and the average was 9.9 x 10-6mg/kg. The concentration of uranium in the mixed sample of beef and ox bone was 7.54 x 10-6mg/kg, and in the camel meat and bone was 3.35 x 10-6mg/kg. The uptake of uranium from soil by the forage grass varies with the amount of U in the soil, the type of soil and grass species. The transfer coefficients CT1 of uranium from soil surface layer, i. e. O to 30 cm, to forage grass were 2.98 x 10-4 for Chenopodium album L., 2.79 x 10-4 for Triticum sativum Lam and 2.67 x 10-5 for Phragmites communis Trin respectively. The coefficients CT2 of U from the forage grass to ox, sheep and camel body were 7.29 x 10-3 ? 1.44 x 10-1 for sheep bone, 5.10 x 10-3 ? 1.25 x 10-1 for the mixed sample of beef and ox bone, 2.26 x 10-3 ? 5.5 x 10-2 for the mixed sample of camel meat and bone and 2.45 x 10-5 ? 2.41 x 10-4 for mutton respectively. The same results were obtained for eight kind of forage grasses

1990-01-01

75

[Fuzzy decision system for ecological distribution of citrus in north-cultivated-marginal area].  

Science.gov (United States)

The fuzzy decision system for ecological distribution of citrus in north-cultivated-marginal area was established by using the data of mean extreme low temperature, accumulated active temperature (> or = 12.5 degrees C), mean temperature in coldest month, annual mean temperature integrated with annual precipitation, days with mean extreme low temperature below -9 degrees C, physiognomy, elevation, inland water body, cold air barrier, and soil nutrition and pH value. The complex reasoning model with imprecision was used in the decision system by introduction of L-R fuzzy number and recognition formula, which made the decision system have a wide range of application in practice. An example of applying the decision system was tested in Anhui province. The result showed that the development of the decision system would provide a useful tool for the decision of the ecological distribution of citrus in north-cultivated-marginal area. PMID:12920889

Zhu, Liwu; Li, Shaowen; Kong, Juanjuan; Jia, Bing

2003-04-01

76

Fuzzy decision system for ecological distribution of citrus in mrtlr cultivated marginal area  

UK PubMed Central (United Kingdom)

The fuzzy decision system for ecological distribution of citrus in north-cultivated- marginal area was established by using the data of mean extreme low temperature?accumulated active temperature(X12 .5 0C)?mean tempera-ture in coldest month?annual mean temperature integrated with annual precipitation?days with mean extremelow temperature below?9 0C ,physiognomy?elevation?inland water body?cold air barrier?and soil nutritionand pH value .The complex reasoning model with imprecision was used in the decision system by introduction of L- R fuzzy number and recognition formula?which made the decision system have a wide range of application inpractice .An example of applying the decision system was tested in Anhui province.The result showed that the development of the decision system would provide a useful tool for the decision of the ecological distribution ofcitrus in nort cultivated- marginal area.

ZHU Liwu; LIShaowen; KONG Juanjuan; HA Bing

2003-04-01

77

[Fuzzy decision system for ecological distribution of citrus in north-cultivated-marginal area].  

UK PubMed Central (United Kingdom)

The fuzzy decision system for ecological distribution of citrus in north-cultivated-marginal area was established by using the data of mean extreme low temperature, accumulated active temperature (> or = 12.5 degrees C), mean temperature in coldest month, annual mean temperature integrated with annual precipitation, days with mean extreme low temperature below -9 degrees C, physiognomy, elevation, inland water body, cold air barrier, and soil nutrition and pH value. The complex reasoning model with imprecision was used in the decision system by introduction of L-R fuzzy number and recognition formula, which made the decision system have a wide range of application in practice. An example of applying the decision system was tested in Anhui province. The result showed that the development of the decision system would provide a useful tool for the decision of the ecological distribution of citrus in north-cultivated-marginal area.

Zhu L; Li S; Kong J; Jia B

2003-04-01

78

Ecological Factors Affecting the Distribution of Woody Vegetation Near the Arkansas River, Tulsa County  

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Full Text Available Ecological factors affecting plant distribution were studied over different rock strata and slope exposures above the Arkansas River, Tulsa County. Here the Wann sandstone caprock is underlain by the Iola limestone formation. The vegetation was analyzed taxonomically by a complete collection throughout one growing season. Belt transects crossing rock strata on all slope exposures permitted computation of parameters summarized by an Importance Percentage for each woody species. Differences in species populations and degree of mesophytism exist on the slope exposures. Sandstone upland dominants are post and blackjack oaks. Smoke-tree, rare in Oklahoma, and chinquapin oak are closely associated in limestone microhabitats, where each occupies a separate niche. The smoke-tree, of disjunct distribution, appears to be a relict of widespread occurrence in past geologic periods. Its survival with limited ecological amplitude is due to the continuance of the microhabitats to which it is so well adapted.

Anne Wanamnaker Long

2004-01-01

79

Geographic Distributions and Ecology of Ornamental Curcuma (Zingiberaceae) in Northeastern Thailand  

Directory of Open Access Journals (Sweden)

Full Text Available The genus Curcuma is a very important economic plant. Members of this genus were used as food, medicine and ornament plants. The objectives of this study were to examine the geographic distributions and ecological conditions in the natural habitats of Curcuma in Northeastern Thailand. Species diversity was examined using the line transect method. Ecological conditions of the species were examined using a sampling plot of 20x20 m. A total of five species were found including Curcuma angustifolia Roxb., C. alismatifolia Gagnep., C. gracillima Gagnep., C. parviflora Wall. and C. rhabdota. These species were in an altitudinal range between 290 m and 831 m above sea level. Four species (C. angustifolia, C. alismatifolia, C. gracillima and C. rhabdota) were distributed in open gaps in dry dipterocarp forest. One species, C. parviflora was found in the contact zone between dry dipterocarp and bamboo (Gigantochloa sp.) forest. C. rhabdota was found only in a habitat with high humidity and shading along the Thailand-Lao PDR border. Significant ecological conditions of the natural habitats of these Curcuma species were identified. Altitude is the most important factor when determining the geographic distributions of these Curcuma species in Northeastern Thailand.

Sutthira Khumkratok; Kriangsuk Boongtiang; Prasit Chutichudet; Pairot Pramaul

2012-01-01

80

Taxonomies of Organizational Knowledge  

Directory of Open Access Journals (Sweden)

Full Text Available The paper systematizes organizational knowledge, starting from the classical dichotomy of tacit and explicit, and outlining the importance of these taxonomies, which may seem reductive, in properly understanding the nature of organizational knowledge and operating with it in business.

Alina Mihaela DIMA; Vitalie STANCOV

2008-01-01

 
 
 
 
81

NCBI Taxonomy Browser  

Science.gov (United States)

The NCBI (National Center for Biotechnology Information) Taxonomy Browser, enables users to search for taxonomic information using the name of superspecific taxa (e.g., Porifera) or the name of a particular organism (e.g., Thalarctos maritimus or polar bear). Returns provide, in addition to taxonomic information, genetic information, nucleotide/protein sequence information, and references.

1995-01-01

82

Potential ecological distribution of Cytauxzoon felis in domestic cats in Oklahoma, Missouri, and Arkansas.  

UK PubMed Central (United Kingdom)

The ecological distribution of Cytauxzoon felis, an often-fatal tick-borne apicomplexan that infects domestic cats, has not been evaluated or identified despite its continued emergence. Infection of C. felis is characterized by lethargy, icterus, fever, anorexia, anemia, and death. The natural vertebrate reservoir of C. felis is the bobcat (Lynx rufus). To determine the possible distribution of C. felis in three states where infection is common (Oklahoma, Missouri, and Arkansas), two separate approaches to ecological niche modeling were implemented. First, a model relating several different climatic layers to geographic locations where cases of C. felis infection were confirmed in domestic cats was developed to predict the possible distribution of the parasite. The second model incorporated occurrences of bobcats with environmental layers and land cover suitable for tick vectors to identify areas of overlap where C. felis transmission was likely. Results of both models indicated a high probability of C. felis from central Oklahoma to south-central Missouri. However, other predicted areas of C. felis occurrence varied between the two modeling approaches. Modeling the vertebrate reservoir and the tick vector predicted a broader possible distribution compared to modeling cases of C. felis infection in domestic cats. Our results suggest that C. felis is likely to extend beyond areas predicted by case modeling due to the presence of both the vector and reservoir.

Mueller EK; Baum KA; Pape? M; Cohn LA; Cowell AK; Reichard MV

2013-02-01

83

Evolutionary and ecological factors underlying the tempo and distribution of yellow fever virus activity.  

UK PubMed Central (United Kingdom)

Yellow fever virus (YFV) is historically one of the most important viruses to affect human populations. Despite the existence of highly effective vaccines for over 70 years, yellow fever remains a significant and re-emerging cause of morbidity and mortality in endemic and high-risk regions of South America and Africa. The virus may be maintained in sylvatic enzootic/epizootic, transitional and urban epidemic transmission cycles with geographic variation in terms of levels of genetic diversity, the nature of transmission cycles and patterns of outbreak activity. In this review we consider evolutionary and ecological factors underlying YFV emergence, maintenance and spread, geographic distribution and patterns of epizootic/epidemic activity.

Carrington CV; Auguste AJ

2013-01-01

84

Ocean distribution, feeding ecology, and return of Pacific salmon in the 1997 El Nino event year  

Energy Technology Data Exchange (ETDEWEB)

The impact of the 1997 El Nino event on the offshore distribution, migration and feeding ecology of Pacific salmon in the North Pacific Ocean and the Bering Sea, and on the return pattern of Japanese chum salmon, was studied. The run pattern of adult chum salmon showed extreme fluctuation by area and run timing. The 1997 abundance and return rate of early runs was significantly increased in the Okhotsk and Nemuro regions compared to the previous five-year means but the abundance and return rate of Japan Sea populations and some of the late runs was decreased. 5 refs., 4 figs.

Kaeriyama, M. [Hokkaido Tokai Univ., Sapporo (Japan); Urawa, S.; Fukuwaka, M. [National Salmon Resources Centre, Nakanoshima, Sapporo (Japan); Myers, K.W.; Davis, N.D. [Washington Univ., Fisheries Research Inst., Seattle, WA (United States); Takagi, S.; Ueda, H. [Hokkaido Univ., Faculty of Fisheries, Hakodate, Hokkaido (Japan); Nagasawa, K.; Ishida, Y. [National Research Inst. of Far Seas Fisheries, Shimizu, Shizuoka (Japan)

1998-12-31

85

The effect of ecological parameters on the distribution of snail vectors of schistosomiasis.  

Science.gov (United States)

The infestation of the water courses showed 32.5% for Biomphalaria alexandrina and 8.75% for Bulinus truncatus. Ecological parameters, showed non significant variations in the water courses harbouring snail vectors and those free from snails except for conductivity in the habitats harbouring B. truncatus. This variation was more highly significant (p<0.001). Of the examined sites, 11.25% were harbouring B. alexandrina and Lymnaea natalenesis living together and 5% of the sites were harbouring B. truncatus and Physa acuta snails. Snail vectors were distributed with different degrees with aquatic plants reflecting the degree of species preference plants for snails' life. PMID:12557938

Kader, A A

2001-04-01

86

Distribution, sources and ecological risk assessment of heavy metals in surface sediments from Lake Taihu, China  

Science.gov (United States)

The distribution, sources and ecological risk of heavy metals in surface sediments from Lake Taihu were studied. Results showed that the measured heavy metals had varied spatial distribution patterns, indicating that they had complex origins and controlling factors. Pearson's correlation analysis revealed that the total phosphorus and the loss on ignition were positively correlated with the measured metals except Cd. Principal component analysis and cluster analysis demonstrated that Hg, Cu, Cr, Cd and Pb might originate from domestic sewage and industrial wastewater, whereas As predominantly originated from natural processes. Potential ecological risk indices indicated that sediment from Wuli Lake, Gonghu Bay and the Northwest Area suffered high pollution, whereas other areas of Lake Taihu were moderately polluted. A comparison of metal levels with the effects range low (ERL) and effects range median (ERM) showed that metals exceeded their corresponding ERL limit at 13.6-72.3% (72.3% for As, 52.4% for Pb, 27.7% for Cu, 22.8% for Cd, 16.0 for Hg and 13.6% for Cr) of the sites investigated. Moreover, 3.90% and 0.50% of the sites sampled exceeded the ERM thresholds for Hg and Pb, respectively.

Yin, Hongbin; Gao, Yongnian; Fan, Chengxin

2011-10-01

87

Distribution, sources and ecological risk assessment of heavy metals in surface sediments from Lake Taihu, China  

International Nuclear Information System (INIS)

[en] The distribution, sources and ecological risk of heavy metals in surface sediments from Lake Taihu were studied. Results showed that the measured heavy metals had varied spatial distribution patterns, indicating that they had complex origins and controlling factors. Pearson's correlation analysis revealed that the total phosphorus and the loss on ignition were positively correlated with the measured metals except Cd. Principal component analysis and cluster analysis demonstrated that Hg, Cu, Cr, Cd and Pb might originate from domestic sewage and industrial wastewater, whereas As predominantly originated from natural processes. Potential ecological risk indices indicated that sediment from Wuli Lake, Gonghu Bay and the Northwest Area suffered high pollution, whereas other areas of Lake Taihu were moderately polluted. A comparison of metal levels with the effects range low (ERL) and effects range median (ERM) showed that metals exceeded their corresponding ERL limit at 13.6–72.3% (72.3% for As, 52.4% for Pb, 27.7% for Cu, 22.8% for Cd, 16.0 for Hg and 13.6% for Cr) of the sites investigated. Moreover, 3.90% and 0.50% of the sites sampled exceeded the ERM thresholds for Hg and Pb, respectively.

2011-01-01

88

TNOs' Taxonomy Confirmed  

Science.gov (United States)

To expand the TNOs’ taxonomy previously proposed (Barucci et al., A&A,371, 1150-1154, 2001; Fulchignoni et al., Earth, Moon and Planets 92, 243-250, 2003; Barucci et al., A.J., 130, 1291-1298, 2005) we analysed the TNO colour data for two groups of objects: the first contains 67 object described by four colours (B-V,V-R,V-I,V-J) and the second contains the only 53 objects for which H and K photometry has been obtained in addition to the others colors, providing a six colors characterization of the sample. As in the previous works, we analysed the TNOs samples using both the Principal Component Analysis (PCA) (Reyment & Joreskog, 1993) and the G-mode analysis (Coradini et al., The Moon 16,175-190, 1976; Barucci et al., Icarus 78, 311-322, 1987; Fulchignoni et al., Icarus 246, 204-212, 2000). The same four homogeneous groups of objects found by Barucci et al. (2005) have been recognized in the present analysis, whatever four or six colors are used as variables, that provides a strong indication of the robustness of the obtained classification. The two-letter designation of the found groups, introduced to distinguish TNO taxonomy from the asteroid taxonomy, has been clearly confirmed: objects having a neutral color with respect to the Sun are classified as BB ("blue") group, those having a very high red color are classified as RR ("red"). The BR group consists of objects with an intermediate blue-red color while IR group includes moderately red objects.

Fulchignoni, Marcello; Barucci, M. A.; Belskaya, I.; Doressoundiram, A.

2006-09-01

89

Distribution, ecology, life history, genetic variation, and risk of extinction of nonhuman primates from Costa Rica  

Directory of Open Access Journals (Sweden)

Full Text Available We examined the association between geographic distribution, ecological traits, life history, genetic diversity, and risk of extinction in nonhuman primate species from Costa Rica. All of the current nonhuman primate species from Costa Rica are included in the study; spider monkeys (Ateles geoffroyi), howling monkeys (Alouatta palliata), capuchins (Cebus capucinus), and squirrel monkeys (Saimiri oerstedii). Geographic distribution was characterized accessing existing databases. Data on ecology and life history traits were obtained through a literature review. Genetic diversity was characterized using isozyme electrophoresis. Risk of extinction was assessed from the literature. We found that species differed in all these traits. Using these data, we conducted a Pearson correlation between risk of extinction and ecological and life history traits, and genetic variation, for widely distributed species. We found a negative association between risk of extinction and population birth and growth rates; indicating that slower reproducing species had a greater risk of extinction. We found a positive association between genetic variation and risk of extinction; i.e., species showing higher genetic variation had a greater risk of extinction. The relevance of these traits for conservation efforts is discussed. Rev. Biol. Trop. 52(3): 679-693. Epub 2004 Dic 15.Se estudió la asociación entre la distribución geográfica, algunos rasgos ecológicos, las historias de vida, la diversidad genética y el riesgo de extinción, en primates no humanos de Costa Rica. Se incluyen todas las especies de primates no humanos del país: los monos araña (Ateles geoffroyi), congo (Alouatta palliata), cara blanca (Cebus capucinus), y tití (Saimiri oerstedii). La distribución geográfica se caracterizó utilizando principalmente bases de datos existentes. Se obtuvo información acerca de sus características ecológicas y de historias de vida mediante una revisión bibliográfica. Se estudió su diversidad genética utilizando electroforesis de isoenzimas. El riesgo de extinción se evaluó usando información bibliográfica. Se encontró que las cuatro especies presentaban variación en todos estos rasgos. Con estos datos, se realizó una correlación de Pearson entre el riesgo de extinción y las variables indicadoras de la distribución geográfica, los rasgos ecológicos, las historias de vida y la diversidad genética, para aquellas especies con una amplia distribución geográfica. Se encontró una asociación entre el riesgo de extinción y la natalidad y la tasa de crecimiento poblacional; las especies con menor natalidad y menor tasa de crecimiento poblacional tenían mayor riesgo de extinción. Se encontró una asociación positiva entre la diversidad genética y el riesgo de extinción; las especies con mayor diversidad genética tenían mayor riesgo de extinción. Se discute la importancia de estos rasgos para la conservación de estas especies.

María E Zaldívar; Oscar Rocha; Kenneth E Glander; Gabriel Aguilar; Ana S Huertas; Ronald Sánchez; Grace Wong

2004-01-01

90

Ecological Distribution of Tithonia diversifolia (Hemsl). A. Gray-A New Exotic Weed in Nigeria  

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Full Text Available Ecological distribution of Tithonia diversifolia (Hemsl). A. Gray was studied in six states of the southwestern Nigeria using three locations in each of the States. The presence of T. diversifolia was recorded in all the States and locations surveyed in varying numbers with associated weeds. Survey data were analysed using detrended correspondence analysis (DCA). The first two ordination axes of the DCA accounted for 67.2% (Axis 1, 40.6%; Axis 2, 26.6%) of variance on the site and species components. The DCA separated Ogun State locations from others. T. diversifolia was found to be closely associated with Boerhavia coccinea, Fleurya ovaliflora, Indigofera subulata, Merremia dissecta, Mimosa pudica, Momordica foetida, Phyllanthus mimosoides, other species of Phyllanthus, Physalis angulata, Schrankia leptocarpa and Sesbania parchycarpa in Ekiti, Lagos, Ondo, Osun and Oyo States while these species were absent in Ogun State.

K.S. Chukwuka; S. Ogunyemi; I. Fawole

2007-01-01

91

Macrophyte distribution and ecological status of the Turiec River (Slovakia): Changes after seven years  

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Full Text Available Characteristics of diversity, abundance, distribution, and ecological status of aquatic macrophytes were observed in 2000 and 2007 on a circa 4.5 km long section of the Turiec River using Kohler's method. In comparison to 2000, the total number of macrophytes in 2007 increased markedly (from 25 to 35), although only the numbers of amphi­phytes and helophytes were changed substantially. The number of hydrophytes increased from 11 to 12; an invasive, Elodea canadenis, was the only new species. The relative plant mass of hydrophytes represents the bulk of all recorded species (95 and 80% in 2000 and 2007, respectively), and it was changed for most hydrophytes. The most significant changes were detected for Myriophyllum spicatum (decrease), filamentous algae (decrease), and Potamogeton crispus (increase). In 2007, the mean mass total (MMT) sum of hydrophytes decreased from 16.46 to 14.5. On the other hand, the MMTsum of amphiphytes and helophytes doubled in value (7.4 and 14.1 in 2000 and 2007, respectively). Within hydrophytes, Batrachium species (including B. aquatile and B. trichophyllum), Myriophyllum spicatum, and Potamogeton crispus were ubiquitous (distribution ratio d > 0.5) in 2000, whereas in 2007 only Batrachium species and Potamogeton crispus were ubiquitous. At all times, Batrachium species were the most frequent species in the study area, and their abundance was relatively high (MMT> 2.5). A poor ecological status (MMP = 0.378 and MMP = 0.333 in 2000 and 2007, respectively) of the surveyed river section was found in both years, but a slight decline of quality as determined on the basis of aquatic plants was observed after 7 years.

Hrivnák R.; O?ahe?ová Helena; Valachovi? M.

2009-01-01

92

Genomic taxonomy of vibrios  

DEFF Research Database (Denmark)

BACKGROUND: Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera) from 32 genome sequences of different vibrio species. We use a variety of tools to explore the taxonomic relationship between the sequenced genomes, including Multilocus Sequence Analysis (MLSA), supertrees, Average Amino Acid Identity (AAI), genomic signatures, and Genome BLAST atlases. Our aim is to analyse the usefulness of these tools for species identification in vibrios. RESULTS: We have generated four new genome sequences of three Vibrio species, i.e., V. alginolyticus 40B, V. harveyi-like 1DA3, and V. mimicus strains VM573 and VM603, and present a broad analyses of these genomes along with other sequenced Vibrio species. The genome atlas and pangenome plots provide a tantalizing image of the genomic differences that occur between closely related sister species, e.g. V. cholerae andV. mimicus. The vibrio pangenome contains around 26504 genes. The V. cholerae core genome and pangenome consist of 1520 and 6923 genes, respectively. Pangenomes might allow different strains of V. cholerae to occupy different niches. MLSA and supertree analyses resulted in a similar phylogenetic picture, with a clear distinction of four groups (Vibrio core group, V. cholerae-V. mimicus, Aliivibrio spp., and Photobacterium spp.). A Vibrio species is defined as a group of strains that share > 95% DNA identity in MLSA and supertree analysis, > 96% AAI, 61% proteome identity. Strains of the same species and species of the same genus will form monophyletic groups on the basis of MLSA and supertree. CONCLUSION: The combination of different analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in the birth of the online genomic taxonomy whereby researchers and end-users of taxonomy will be able to identify their isolates through a web-based server. This novel approach to microbial systematics will result in a tremendous advance concerning biodiversity discovery, description, and understanding.

Thompson, Cristiane C.; Vicente, Ana Carolina P.

2009-01-01

93

A New Hacker Taxonomy  

UK PubMed Central (United Kingdom)

s engaged in hacking thegeneric hacker term needs to be broken down into moreuseful and empirically valid categories (Chantler, 1996).Fortunately there have been some studies that haveattempted to granulize or operationally define the termhacker into more useful subcategories (Chantler, 1996;Landreth, 1985; Parker, 1998; Post, 1996;). Many of thestudies used data from the popular media, self reportsurveys, or personal observations.One of the first attempts to more clearly define thehacker community was Landreth (1985). Landreth proposed aclassification system based on the activities the hackerTaxonomy 3was involved in. He developed six categories; novice,student, tourist, crasher, thief.The novice was considered the least experienced, andtheir activities were viewed as petty mischief making(Landreth, 1985). The student was just that, a student.Rather than work on homework they occupied their timeexploring others' systems. They were bright and usuallyfound school b

94

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model  

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Full Text Available Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

A. P. Palacz; M. A. St. John; R. J. W. Brewin; T. Hirata; W. W. Gregg

2013-01-01

95

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model  

DEFF Research Database (Denmark)

Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources

Palacz, Artur; St. John, Michael

2013-01-01

96

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model  

Science.gov (United States)

Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

Palacz, A. P.; St. John, M. A.; Brewin, R. J. W.; Hirata, T.; Gregg, W. W.

2013-05-01

97

Characteristics of calcareous dinoflagellate cyst assemblages in a major upwelling region (NW Africa) Spatial distribution, fluxes and ecology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this comparative study, surface sediment and sediment trap samples off the NW African coast were investigated to understand the ecology, spatial distribution and fluxes of calcareous dinoflagellate cysts (dinocysts). From surface sediment samples off the Moroccan coast, relative and absolute abun...

Richter, Dorit

98

[Ecological distribution patterns of soil microbes under artificial Eucalyptus grandis stand].  

UK PubMed Central (United Kingdom)

In order to find out the ecological distribution patterns of soil microbes under artificial Eucalyptus grandis stand, the amount and distribution of soil bacteria, fungi and actinomycetes in Hongya County of Sichuan Province were investigated in 2004. The results showed that soil microbial population under Eucalyptus grandis stand varied with seasons, being the maximum in autumn, fewer in spring, and the minimum in summer. The numbers were decreased in order of bacteria > actinomycetes > fungi, which were mainly concentrated in 0-20 cm soil layer, and rapidly decreased with increasing soil depth. In 0-60 cm soil layer, the numbers of aerobic bacteria were 0. 31 x 10(6) - 14.39 x 10(6), actinomycetes were 0.06 x 10(6) - 0.79 x 10(6), fungi were 0.06 x 10(6) - 0.79 x 10(6), and anaerobes were 0.05 x 10(6) - 3.22 x 10(6) CFU x g(-1). Comparing with artificial C. glauca stand and farming land, Eucalyptus grandis stand had a larger number of soil microbes, suggesting that Eucalyptus grandis was benefit for soil microbial activity. The Simpson and Shannon-Wiener index of the physiological groups of bacteria was 0.773 and 1.896, respectively.

Feng J; Zhang J

2005-08-01

99

[Ecological distribution patterns of soil microbes under artificial Eucalyptus grandis stand].  

Science.gov (United States)

In order to find out the ecological distribution patterns of soil microbes under artificial Eucalyptus grandis stand, the amount and distribution of soil bacteria, fungi and actinomycetes in Hongya County of Sichuan Province were investigated in 2004. The results showed that soil microbial population under Eucalyptus grandis stand varied with seasons, being the maximum in autumn, fewer in spring, and the minimum in summer. The numbers were decreased in order of bacteria > actinomycetes > fungi, which were mainly concentrated in 0-20 cm soil layer, and rapidly decreased with increasing soil depth. In 0-60 cm soil layer, the numbers of aerobic bacteria were 0. 31 x 10(6) - 14.39 x 10(6), actinomycetes were 0.06 x 10(6) - 0.79 x 10(6), fungi were 0.06 x 10(6) - 0.79 x 10(6), and anaerobes were 0.05 x 10(6) - 3.22 x 10(6) CFU x g(-1). Comparing with artificial C. glauca stand and farming land, Eucalyptus grandis stand had a larger number of soil microbes, suggesting that Eucalyptus grandis was benefit for soil microbial activity. The Simpson and Shannon-Wiener index of the physiological groups of bacteria was 0.773 and 1.896, respectively. PMID:16262052

Feng, Jian; Zhang, Jian

2005-08-01

100

Ecological characteristics of Triatoma patagonica at the Southern limit of its distribution (Chubut, Argentina)  

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Full Text Available This study aimed at identifying the ecological characteristics of Triatoma patagonica Del Ponte 1929 (Hemiptera: Reduviidae) and evaluating the epidemiological importance of this species at its southernmost distribution limit. We carried out two surveys in the Province of Chubut, in summer and in spring, 1998. In each survey, we interviewed local health care agents for triatomine recognition and reports of the bugs, followed by entomological searches in houses and peridomestic and silvatic biotopes. The presence of T. patagonica was confirmed in two of the five localities indicated by interview. In agreement with previous studies, all these positive localities were east of the 11°C isotherm, within the Monte phytogeographic province. Triatomine abundance and infestation levels (in peridomiciles and peridomestic biotopes) were higher in summer than in spring, possibly reflecting adverse environmental conditions such as flood and cold winter weather. In the silvatic environment, we found three adult bugs under rocks in summer. In peridomestic sites bugs were only found associated with chickens, which were also the only blood meal source identified. Infection by Trypanosoma cruzi was not detected. We conclude that T. patagonica at its southernmost distribution limit does not represent a risk to public health due to its low abundance, lack of association with humans, and absence of T. cruzi infection.

Wisnivesky-Colli Cristina; Vezzani Darío; Pietrokovsky Silvia M; Scurti Hugo; Iriarte Jorge

2003-01-01

 
 
 
 
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Ecological characteristics of Triatoma patagonica at the southern limit of its distribution (Chubut, Argentina).  

UK PubMed Central (United Kingdom)

This study aimed at identifying the ecological characteristics of Triatoma patagonica Del Ponte 1929 (Hemiptera: Reduviidae) and evaluating the epidemiological importance of this species at its southernmost distribution limit. We carried out two surveys in the Province of Chubut, in summer and in spring, 1998. In each survey, we interviewed local health care agents for triatomine recognition and reports of the bugs, followed by entomological searches in houses and peridomestic and silvatic biotopes. The presence of T. patagonica was confirmed in two of the five localities indicated by interview. In agreement with previous studies, all these positive localities were east of the 11 degrees C isotherm, within the Monte phytogeographic province. Triatomine abundance and infestation levels (in peridomiciles and peridomestic biotopes) were higher in summer than in spring, possibly reflecting adverse environmental conditions such as flood and cold winter weather. In the silvatic environment, we found three adult bugs under rocks in summer. In peridomestic sites bugs were only found associated with chickens, which were also the only blood meal source identified. Infection by Trypanosoma cruzi was not detected. We conclude that T. patagonica at its southernmost distribution limit does not represent a risk to public health due to its low abundance, lack of association with humans, and absence of T. cruzi infection.

Wisnivesky-Colli C; Vezzani D; Pietrokovsky SM; Scurti H; Iriarte J

2003-12-01

102

Ecological variables governing habitat suitability and the distribution of the endangered Juliana’s golden mole  

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Full Text Available Juliana’s golden mole (Neamblysomus julianae) occurs in three isolated populations in the northeastern parts of South Africa. This cryptic species is not evenly distributed throughout its restricted range and appears to have very specific habitat requirements. Its endangered status reflects the necessity for a conservation management programme, which to date has not been comprehensive. A primary hindrance to such initiatives has been the lack of information pertaining to its habitat requirements.We assessed various soil and vegetation parameters, at each population site, in areas where the animals were found to be present or absent. A multiple logistic regression model highlighted the importance of soil hardness (governed by soil particle size distribution), in combination with the cover provided by trees, as the two ecological factors that best explained habitat suitability for Juliana’s golden mole at the three localities. An IndVal analysis failed to identify any plant species that could reliably act as an indicator of habitat suitability for this fossorial mammal. These results have important implications for the conservation of the species.

Craig R. Jackson; Trine Hay Setsaas; Mark P. Robertson; Nigel C. Bennett

2011-01-01

103

DCAordination of ecological distribution of saprophytic bryophytes in forest ecosystems in Changbai Mountains.  

UK PubMed Central (United Kingdom)

Application of DCA to study the ecological distribution of saprophytic bryophytes in Changbai Mountains showed thatthere existed differences in the components of saprophytic bryophyte communities in Pinus koraiensis broad-leavedmixed forest?dark conifer forest?and the transitive forest between Pinus koraiensis broad-leaved mixed forest anddark conifer forest .In Pinus koraiensis broad-leaved mixed forest?Plagiomniu m cuspidatu m?Thuidium philibertiiand Brachythecium buchananii were the main saprophyte bryophytes .Plagio mniu m cuspidatu m?T sac hycystis aR-ellaris?Thui di u m cy mbi fo li u m?Callichladiu m haldanianu m and loco msplendens were the main saprophyticbryopytes in the transitive forest between Pinus koraiensis broad-leaved forest and dark conifer forest.Whereas? lo-co miu m splendens?Sanionia uncinata?IZhytidiadelphus triquetrus?Oncophorus wahlenbergii and Ptilium cristcastrens were the main ones in dark conifer forest .The total coverage and species diversity of saprophytic bryophyteswere the highest in dark conifer forest .Altitude and forest canopy density were the two important environmental factors influencing the distribution patterns of saprophytic bryophytes in the forest ecosystems in Changbai Mountains.

Guo Shuiliang; Cao Tong

1999-01-01

104

A Preliminary Study on the Fauna Composition and Ecological Distribution of Waterfowl of Leizhou Peninsula Wetland  

UK PubMed Central (United Kingdom)

The Survey of the fauna composition and ecological distribution of waterfowl of Leizhou Peninula was conducted from Oct., 1998 to Jun., 2000. The results showed: 56 species of water birds were recorded, which belong to 7 orders, 9 families, in Leizhou Peninsula. Among these water birds, Ardeidae, Anatidae and Charadriidae and Scoipacidae are predominant, and 41 species were identified. In 56 species of the water birds, 35 species of Palearctic birds, 13 species of Oriental birds and 8 species of widespread birds. There are 33 species winter birds, 13 species are residents, 7 species are passengers, 3 species are summer birds. Among winter birds, Anatidae and Charadriidae and Scoipacidae are predominant; resident birds are mainly composed of Ardeidae. Most of Laridae are winter birds in this area. Thirty eight species of water birds are protected by relative laws or agreements. Total of 49 water birds in Leizhou Peninsula distribute in coastal wetland mostly. Mangrove is the most important habitat of water birds, 37 species of water birds were found in mangrove.

Wu Shibao; Ke Yayong; Wu Guisheng; Lu Kaihe; Bi Xiaofeng

2002-01-01

105

STUDIES ON THE ECOLOGICAL DISTRIBUTION OF MICROORGANIS MIS IN THE VVFST LAKE?HANGZ HOU  

UK PubMed Central (United Kingdom)

The ecological distributions of different microbial physiological groups in West Lake?Hangzhou were studied from 1995 to 1996.The heterotrophic bacteria including amm onifie rs?cellulose decomposers?nitrate reducers and denitrifiers were rich in Yuhu Lake? where the water was eutrophic;while autotrophic bacteria?shch as ammonia oxidizers and nitrite oxidizers?were more com mon in Xiaonan Lake where the water quality was relativelygood·Ammonifiers and cellulose decomposers had the negative relations with ambient tempe rat ure?no matter whether they were in the water body or in the sediment·Compared with historical data?it was founded that the heterotrophic bacteria and coliform groups were decreased significantly after comprehensive treatment of West Lake in 1986?but recently they have increasing trend .After determining 78 heterotrophic strains isolated in water body in Apr .1996 .The authors found that Pseudomonas and Enterobacteriaceae were the dominat-ed species;in 117 heterotrophic strains isolated from the sediments in Oct .1995 and Mar. 1996?about 50%were belonged to Bacillus and about 24%were Enterobacteriaceae .According to the data supplied by co?operators?it was founded that am monifiers?cellulose decomposers?nitrate reducers and denitrifiers in the water body had more constrained relationswith total nitrogen than with total phosphorous .It was also founded that these bacteria had the negative relationship with the densities of phytoplankton and zooplankton.

WU Gen?fu; W U Xue?chang; W U Jie; XUAN Mao?dong

2000-01-01

106

Hydropower developments in Canada: number, size and jurisdictional and ecological distribution  

Energy Technology Data Exchange (ETDEWEB)

For over 200 years, energy production and consumption, along with all human activities, have been contributing to global warming. This report is part of a project that examines 10 major energy sectors to provide information on Canada's energy options in the face of climate change; this present study gives information on hydropower reservoirs and associated dams in Canada. The mapping, jurisdictional and ecological distribution of reservoirs and dams across Canada is provided herein. Canada's hydropower installations are composed of 271 large hydropower facilities covering 58,015 km2 with a capacity of 71,857 MW, accounting for 44% of Canada's total technical hydroelectric capacity. Quebec, Ontario and British Columbia are the provinces with the most large hydropower dams; 19% of the watersheds are occupied in part by hydropower reservoirs and the taiga shield, boreal shield and montane cordillera ecozones contain most of the reservoir areas. The majority of future developments are expected to be built within 5km of intact forest landscapes.

Lee, Peter G.; Hanneman, Matt; Cheng, Ryan [Global Forest Watch Canada (Canada)

2011-08-15

107

Distribution and ecology of Dreissena polymorpha (pallas) and Dreissena bugensis (andrusov) in the upper Volga basin  

Science.gov (United States)

This paper presents data on contemporary distribution patterns of two species of Dreissenidae, the zebra mussel (Dreissena polymorpha) and the Quagga mussel (Dreissena bugensis), and their role in ecosystem processes in the Ivan'kovo, Uglich, Rybinsk, and Gorky Reservoirs of the Upper Volga River basin. The role of zebra mussel was also studied in experimental mesocosms of 15 m3. Maximum abundance and species diversity of macroinvertebrates, especially of leeches, polychaetes, crustaceans, and heterotopic insects, were attained in the portions of reservoirs where Dreissenidae were present and in experimental mesocosms where zebra mussel biomass was the highest. In the mesocosm studies, the presence of zebra mussel druses (colonies) provided shelter for macroinvertebrates, reducing their vulnerability to predation by perch (Perca fluviatills) larvae and yearlings, thereby increasing macroinvertebrate species diversity. It was shown that in addition to its role in aquatic biocenosis (ecological community) formation and water purification, Dreissenidae are important food objects for benthophagous fishes, especially roach (Rutilus rutilus). Examination of intestines of benthophagous fishes showed that the length of Dreissenidae ranged from 5 to 20 mm in roach; from 4 to 14 mm in silver bream (Blicca bjoerkna), and from 2 to 10 mm in bream (Abramis brama). The largest mussels consumed were Quagga mussels up to 30 mm, noted in the predatory cyprinid, ide (Leuciscus idus). Copyright ?? 2006 by ASTM International.

Shcherbina, G. Kh.; Buckler, D. R.

2006-01-01

108

Spatial distribution and ecological risk assessment of metals in sediments of Baiyangdian wetland ecosystem  

DEFF Research Database (Denmark)

Although there are many studies of heavy metal contaminations of sediments, attention has seldom been paid to the problem in developing countries. The purpose of this article is to find the distribution and ecological risk of As, Hg, Cr, Cd, Pb, Cu, and Zn in surface sediment of Baiyangdian which is the biggest wetland in Northeast China. We apply three methodologies. The first is literature analysis comparing total concentrations of heavy metals with other water bodies around world. The second is Chinese Environmental Quality Standard for Soils (EQSS), National Environmental Protection Agency of China 1995, and the third is Soil and Aquatic Sediment Guidelines and Standards issued by New York Department of Environmental Conservation (NYSDEC). The results show that compared to other water bodies around the world, the seven heavy metals are low. However, Cd was found in the most polluting level of EQSS near a village and was second grade some distance from it. The village was also the most polluted site of Zn,which was in the second grade. When assessed by NYSDEC, Cu, Cr, and As contaminated the sediment and with moderate impacts on benthic life while Pb, Hg, and Zn were found at tolerable levels throughout Baiyangdian. The centre of Cu and Cr contamination was also near the village. As is the most polluting heavy metals with a major occurrence in the middle of the wetland. There were no heavy metals creating severe disturbance to the benthic communities. Based on the assessment, this article proposes different options for more sustainable management.

Su, Liya; Liu, Jingling

2011-01-01

109

Biomonitors and the assessment of ecological impacts: Distribution of herbivorous epifauna in contaminated macroalgal beds  

International Nuclear Information System (INIS)

We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world. - The accumulation of metals by macroalgae may pose ecological threats to herbivorous epifauna in ports and harbours worldwide.

2008-01-01

110

Biomonitors and the assessment of ecological impacts: Distribution of herbivorous epifauna in contaminated macroalgal beds  

Energy Technology Data Exchange (ETDEWEB)

We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world. - The accumulation of metals by macroalgae may pose ecological threats to herbivorous epifauna in ports and harbours worldwide.

Roberts, David A. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW (Australia)], E-mail: d.roberts@student.unsw.edu.au; Johnston, Emma L.; Poore, Alistair G.B. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW (Australia)

2008-11-15

111

Abundance, diversity, and distribution of mosquito vectors in selected ecological regions of Kenya: public health implications.  

Science.gov (United States)

The diversity of mosquito arbovirus vectors was investigated to define regional risk of arbovirus transmission in Kenya. Mosquitoes were sampled between April, 2007 and December, 2010 at thirteen sites across seven administrative provinces and ecological zones. CDC light traps were used to collect mosquitoes while human-landing collection was conducted in five of the sites to target day-feeding Aedes (Stegomyia) species. Over 524,000 mosquitoes were collected and identified into 101 species, 30 of them known vectors of arboviruses endemic to Kenya. Ae. (Neomelaniconion) mcintoshi and Ae. (Aedimorphus) ochraceus were most abundant in Garissa in the arid northeastern province, and Mansonia uniformis and Mn. africana in semi-arid Baringo in the Rift Valley Province. Ae. ochraceus, Mn. africana and Mn. uniformis were also significant in Nyanza Province, while Ae. (Neomelaniconion) circumluteolus predominated in Budalangi, Western Province. Aedes (Stegomyia) aegypti was predominant in Rabai in the Coast Province but insignificant in the western and Nyanza sites. Culex pipiens was abundant in Rift Valley and Nyanza Provinces around the lake shores. This study highlights the potential for emergence and re-emergence of arboviral diseases among vulnerable populations. This calls for comprehensive mapping of vector distribution and abundance for planning focused vector control measures. PMID:23701618

Lutomiah, Joel; Bast, Joshua; Clark, Jeffrey; Richardson, Jason; Yalwala, Santos; Oullo, David; Mutisya, James; Mulwa, Francis; Musila, Lillian; Khamadi, Samoel; Schnabel, David; Wurapa, Eyako; Sang, Rosemary

2013-06-01

112

Distribution and ecology of Carex secalina in the Czech Republic and Slovakia  

Directory of Open Access Journals (Sweden)

Full Text Available Current and historical occurrence as well as coenotic affinity and ecology of Carex secalina in the Czech Republic and Slovakia are presented. The study is based on revision of herbarium specimens from 25 herbaria, literature data excerption and a field survey carried out during 2004-2010. Altogether, 168 sites were documented in the Czech Republic divided to two separate areas. Stabile occurrence trend was found in last decades, because 45 localities were documented in period 1975-1999 (27% of sites) and recent occurrence was confirmed at 42 localities (24% of sites). On the basis of our current knowledge the species was included into the IUCN threat category VU (vulnerable). In Slovakia, 19 localities of the species were recorded in total, but only 4 sites were confirmed recently (21% of sites recorded). However, only a small number of individuals was recorded there (less than 50 individuals in total) and half of this sites is acutely threatened by destruction (ploughing, secondary succession). Therefore, the C. secalina status in the Slovak Red List was changed to the IUCN category "critically endangered" (CR). Results of the study are summarised in the maps of historical and current species distribution. C. secalina usually occurred in halophytic grassland communities, especially in association Agrostio stoloniferae-Juncetum ranarii Vicherek 1962. However, it may occur in many other communities which suggest that the species had not well-defined coenotic relationships. On the basis of our knowledge, we consider C. secalina as an obligate halophyte.

Pavol Eliáš jun.; Vít Grulich; Daniel Dít?; Dušan Senko

2012-01-01

113

Abundance, diversity, and distribution of mosquito vectors in selected ecological regions of Kenya: public health implications.  

UK PubMed Central (United Kingdom)

The diversity of mosquito arbovirus vectors was investigated to define regional risk of arbovirus transmission in Kenya. Mosquitoes were sampled between April, 2007 and December, 2010 at thirteen sites across seven administrative provinces and ecological zones. CDC light traps were used to collect mosquitoes while human-landing collection was conducted in five of the sites to target day-feeding Aedes (Stegomyia) species. Over 524,000 mosquitoes were collected and identified into 101 species, 30 of them known vectors of arboviruses endemic to Kenya. Ae. (Neomelaniconion) mcintoshi and Ae. (Aedimorphus) ochraceus were most abundant in Garissa in the arid northeastern province, and Mansonia uniformis and Mn. africana in semi-arid Baringo in the Rift Valley Province. Ae. ochraceus, Mn. africana and Mn. uniformis were also significant in Nyanza Province, while Ae. (Neomelaniconion) circumluteolus predominated in Budalangi, Western Province. Aedes (Stegomyia) aegypti was predominant in Rabai in the Coast Province but insignificant in the western and Nyanza sites. Culex pipiens was abundant in Rift Valley and Nyanza Provinces around the lake shores. This study highlights the potential for emergence and re-emergence of arboviral diseases among vulnerable populations. This calls for comprehensive mapping of vector distribution and abundance for planning focused vector control measures.

Lutomiah J; Bast J; Clark J; Richardson J; Yalwala S; Oullo D; Mutisya J; Mulwa F; Musila L; Khamadi S; Schnabel D; Wurapa E; Sang R

2013-06-01

114

The integrative future of taxonomy.  

UK PubMed Central (United Kingdom)

BACKGROUND: Taxonomy is the biological discipline that identifies, describes, classifies and names extant and extinct species and other taxa. Nowadays, species taxonomy is confronted with the challenge to fully incorporate new theory, methods and data from disciplines that study the origin, limits and evolution of species. RESULTS: Integrative taxonomy has been proposed as a framework to bring together these conceptual and methodological developments. Here we review perspectives for an integrative taxonomy that directly bear on what species are, how they can be discovered, and how much diversity is on Earth. CONCLUSIONS: We conclude that taxonomy needs to be pluralistic to improve species discovery and description, and to develop novel protocols to produce the much-needed inventory of life in a reasonable time. To cope with the large number of candidate species revealed by molecular studies of eukaryotes, we propose a classification scheme for those units that will facilitate the subsequent assembly of data sets for the formal description of new species under the Linnaean system, and will ultimately integrate the activities of taxonomists and molecular biologists.

Padial JM; Miralles A; De la Riva I; Vences M

2010-01-01

115

Ecological attributes and distribution of Anatolian black pine [Pinus nigra Arnold. subsp. pallasiana Lamb. Holmboe] in Turkey.  

Science.gov (United States)

The aim of this study is to determine ecoregions and the effect of ecological properties on natural distribution of Anatolian black pine [Pinus nigra Arnold. subsp. pallasiana Lamb. (Holmboe)] in Turkey. The results suggest that 6 ecoregions exist and climate, parent material, topography, anthropogenic factors, floristic composition, competition are ecological factors that determine the distribution of Black pine in Turkey. But, climatic elements such as precipitation and temperature are the dominant factors. The six ecoregions with different characteristics have been identified and distribution ofAnatolian black pine revealed depending on ecological features of each region. Each region has its own characteristics that affect the growth and distribution of black pine. Productive black pine forest are found on the subhumid-semiarid areas receiving humid air mass coming from the seas either on northern or southern coastal mountains of Turkey. The poor and/or lowest productive stands occur in the semiarid parts of Inner Anatolia. Black pine can grow on all material in the semi-arid and sub-humid cold climates, but deep weatheared parent materials are the best for growing of black pine. PMID:23424857

Atalay, Ibrahim; Efe, Recep

2012-04-01

116

Ecological attributes and distribution of Anatolian black pine [Pinus nigra Arnold. subsp. pallasiana Lamb. Holmboe] in Turkey.  

UK PubMed Central (United Kingdom)

The aim of this study is to determine ecoregions and the effect of ecological properties on natural distribution of Anatolian black pine [Pinus nigra Arnold. subsp. pallasiana Lamb. (Holmboe)] in Turkey. The results suggest that 6 ecoregions exist and climate, parent material, topography, anthropogenic factors, floristic composition, competition are ecological factors that determine the distribution of Black pine in Turkey. But, climatic elements such as precipitation and temperature are the dominant factors. The six ecoregions with different characteristics have been identified and distribution ofAnatolian black pine revealed depending on ecological features of each region. Each region has its own characteristics that affect the growth and distribution of black pine. Productive black pine forest are found on the subhumid-semiarid areas receiving humid air mass coming from the seas either on northern or southern coastal mountains of Turkey. The poor and/or lowest productive stands occur in the semiarid parts of Inner Anatolia. Black pine can grow on all material in the semi-arid and sub-humid cold climates, but deep weatheared parent materials are the best for growing of black pine.

Atalay I; Efe R

2012-04-01

117

A Taxonomy of Learning through Asynchronous Discussion  

Science.gov (United States)

This article presents a five-tiered taxonomy that describes the nature of participation in, and learning through, asynchronous discussion. The taxonomy is framed by a constructivist view of asynchronous discussion. The five tiers of the taxonomy include the following: (a) passive participation, (b) developmental participation, (c) generative…

Knowlton, Dave S.

2005-01-01

118

Contributions to Distribution, Reproduction Biology and Ecology of Vormela peregusna (G?ldenstadt, 1770) (Mammalia: Carnivora) in Turkey  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, both captured and uncaptured Vormela peregusna were investigated for their distribution, reproduction biology, some ecological observations and morphological characteristics in our laboratory, and campus area at Erciyes University in Kayseri, Turkey. It was observed that there is a cannibalism within population in Vormela peregusna. The morphological evaluations indicated that Turkish V. peregusna is the same to V. peregusna from Israel.

Co kun Tez; Slam Gunduz; Haluk Kefel o lu

2001-01-01

119

Dynamic taxonomies and faceted search  

CERN Multimedia

Current access paradigms for the Web, i.e., direct access via search engines or database queries and navigational access via static taxonomies, have recently been criticized because they are too rigid or simplistic to effectively cope with a large number of practical search applications. A third paradigm, dynamic taxonomies and faceted search, focuses on user-centered conceptual exploration, which is far more frequent in search tasks than retrieval using exact specification, and has rapidly become pervasive in modern Web data retrieval, especially in critical applications such as product selec

Sacco, Giovanni Maria

2009-01-01

120

ECOLOGICAL STATUS, DIVERSITY RESOURCES AND DISTRIBUTION OF THE LITTLE KNOWN GENUS TAINIA BLUME (ORCHIDACEAE) IN ASSAM OF NORTH EAST INDIA  

Directory of Open Access Journals (Sweden)

Full Text Available Among the Orchid flora of Assam, four species of terrestrial Orchid Tainia recorded viz., T. angustifolia, T. latifolia, T. minor and T. wrayana in an intensive field survey during 1996-2010. The present paper deals Tainia species diversity and distribution in Assam of North East India. This attempt is the first step to correct taxonomic identification to workout currently accepted botanical names with present ecological status, date of collection, habitat, altitudinal ranges, phenology and local and general distribution of Tainia species in the regions.

Khyanjeet Gogoi¹, Raju Das² and Rajendra Yonzone³

2012-01-01

 
 
 
 
121

GENETIC DIVERSITY RESOURCES, DISTRIBUTION AND PRESENT ECOLOGICAL STATUS OF FIFTEEN NEW RECORDS OF ORCHID SPECIES TO ASSAM OF EASTERN HIMALAYA  

Directory of Open Access Journals (Sweden)

Full Text Available Present paper deals 15 Orchid species with 12 genera viz., Bryobium pudicum, Bulbophyllum apodum, Chrysoglossum ornatum, Cleisostoma linearilobatum, C. simondii, Collabium chinense, Diploprora championii, Eria connate, E. ferruginea, Taeniophyllum crepidiforme, Tainia wrayana, Thelasis pygmaea, Thrixspermum acuminatissimum, T. pygmaeum, and Z. glandulosa were recorded from Dibrugarh district of Assam of Eastern Himalaya for the first time and reported as new distributional records to the state. Out of 15 species 11 species are epiphytic and the rest 4 are terrestrial in habitat. All the species are enumerated with latest citation, brief description, phonology, present ecological status and local distribution within Assam.

Khyanjeet Gogoi¹, R. L. Borah², G. C. Sharma³ and Rajendra Yonzone4

2012-01-01

122

Determinations of Urban Political Ecology: The Distribution Pattern Canopy Cover of Tree and Spatial inequality in Tehran  

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Full Text Available Extended abstract1-IntroductionInequality of green space distribution is a type of social production which by creating uneven ecological conditions in a feedback cycle plays its role on the quality of environment and intensification of imbalances inside the urban living environment. Most of the studies conducted so far have focused on the development or distribution of public green space but the truth is that public green spaces have not been the only source of urban metabolism (from the viewpoint of green space function) and a great part of the role of urban green space is undertaken by private green spaces. “What effect do private greeneries located in residential areas have on the quality of citizens’ life or what kind of reality is asserted by their development and distribution pattern in the urban life of today’s modern society” were issues of less attention. Thus, considering the interconnection of green space production and distribution pattern (public and private) with the rest of natural, social, economic and fabric conditions, the present research benefits from NDVI (Normalized Difference Vegetation Index) as a dependent variable which has been influenced by ecological, social, fabric and economic variables and has analyzed them to identify effective factors in Tehran inequality urban green space. The present article theoretically makes use of urban political ecology approach and is considered a correlational research. The required data have been prepared and analyzed by some types of software such as ArcGIS, ArcView, IDRISI, ERDAS Imagine, and SPSS. In conducting this research some techniques have been used such as; “Average Distance to Nearest Neighbor”, “Square Analysis”, “Correlational Analysis and Factor Analysis”. 2-Theoretical basis The present study is theoretically based on an urban political ecology approach. Urban components including green space from urban political ecological perspective are considered a kind of social production whose imagination and change are influenced by political economy, dominant pattern of public and private ownership in society (Heynen, Perkins and Roy, 2006: 3). The aforementioned perspective clearly states that urban material conditions which includes urban environment too are controlled and manipulated by the elite and city experts to serve their interests. This issue is conducive to make some of the urban social groups marginalized and deprived from natural riches and urban environmental artifacts. As a result, the quality of urban environment (physically and socially) increases in some neighborhoods and decreases in others (Heynen, Kaika and Swyngedouw, 2006: 1-15). Since unequal greenery distribution with creating imbalanced ecological conditions often plays its role in a feedback cycle on environment quality and intensification of inequalities within urban life environment, the present study uses pattern of canopy distribution located in areas of residential uses (private and public) to reveal social, economic and spatial inequalities in Tehran. 3- DiscussionThe results of this research in relation to Tehran city confirm the determining position of urban political ecology in forming distribution pattern and density of trees canopy located in areas of Tehran. This is a subject which is confirmed by studies conducted on urban green space (including public and private) in the cities such as San Diego, Toronto (by Perkins, Heynen and Wilson 2004, Scobedo and colleagues 2005, Heynen, Perkins and Roy 2006 and Conway, Shakeel and Atallah 2011). Also, so far many researchers on the urban issues of Tehran city (such as Madanipoor 2005, Horkad 2009) have emphasized the conformity of natural topography over social topography in Tehran. The result f this attempt, while confirming aforementioned perspectives, indicated that the distribution pattern of canopy density in residential areas(private urban green space) has a greater capability to portray social classifications and environmental quality and as a result spatial inequalities in Teh

T. Karami; M. Soleimani; H. Afrakhteh; H. Hataminejad

2012-01-01

123

Building and Maintaining Web Taxonomies  

UK PubMed Central (United Kingdom)

A recognized problem for internet commerce is the task ofbuilding a product taxonomy from web pages, without access to corporatedatabases, and then populating a database with link informationabout service, spare parts, reviews, product specifications, product family,etc. A key precursor for this task is the ability to build classificationhierarchies in an unsupervised manner of web pages potentially useful.

Wray Buntine; Sami Perttu; Henry Tirri

124

Taxonomy of the extrasolar planet  

CERN Document Server

When a star is described as a spectral class G2V, we know that the star is similar to our Sun.We know its approximate mass, temperature, age and size. In our work with extrasolar planets database, it is very useful to have a taxonomy scale (classification), for example, like the Harvard classification for stars. This new taxonomy has to be comprehensible and present the important information about extrasolar planets. The important information of extrasolar planets are their mass, radius, period, density, eccentricity, temperature, and their distance from the parent star. There are too many parameters, that is, taxonomy with six parameters would be complicated and difficult to apply. We propose following the extrasolar planet taxonomy scale with only four parameters. The first parameter is the information about the mass of an extrasolar planet in the form of the units of the mass of other known planets, where M - Mercury, E - Earth, N - Neptune, and J - Jupiter. The second parameter is the distance from its pa...

Plávalová, E

2011-01-01

125

Taxonomy, distribution, and notes on the termites (Isoptera: Kalotermitidae, Rhinotermitidae, Termitidae) of Puerto Rico and the U.S. Virgin Islands.  

UK PubMed Central (United Kingdom)

Termite surveys from Buck, Culebra, Mona, Puerto Rico, St. Croix, St. John, St. Thomas, and Vieques islands yielded 1,564 colony samples from 274 sites. Twenty-one species were recorded including: Cryptotermes brevis, Cryptotermes havilandi, Cryptotermes rotundiceps, Cryptotermes undulans, Glyptotermes liberatus, Glyptotermes pubescens, Incisitermes bequaerti, Incisitermes furvus, Incisitermes incisus, Neotermes intracaulis n. sp., Neotermes mona, and Procryptotermes corniceps (Kalotermitidae); Coptotermes havilandi, Heterotermes sp., and Prorhinotermes simplex (Rhinotermitidae); and Anoplotermes n. sp. undescribed, Caribitermes discolor, Nasutitermes acajutlae, Nasutitermes costalis, Parvitermes wolcotti, and Termes hispaniolae (Termitidae). Of these, twelve are West Indian endemics, six have endemic ranges that include the tropical American mainland, and three are nonendemic pests. Distribution maps and keys based on the soldier caste and the winged imago are provided. Neotermes intracaulis, a new species from St. Croix, is described from the imago and soldier. Additional descriptions or redescriptions are given for G. liberatus (imago), I. incisus (imago and soldier), Ca. discolor (imago and soldier), and Pa. wolcotti (imago). An understanding of West Indian termite biogeography relies on current faunal distributions and the few fossil termites available from Hispaniola. Over-water dispersal of termites on flotsam is the most plausible mechanism for contemporary distributions, however, vicariate speciation cannot be discounted for species that are poor dispersalists. Faunal composition of Puerto Rican and the Virgin Islands termites suggest a biogeographical origin that is derived from both western and southern mainland sources.

Scheffrahn RH; Jones SC; Krecek J; Chase JA; Mangold JR; Su NY

2003-05-01

126

Distribution and habitat ecology of the sorediate species of Menegazzia (Parmeliaceae, lichenized Ascomycota) in Chile/ Distribución y ecología de las especies sorediosas de Menegazzia (Parmeliaceae, Ascomycota liquenizado) en Chile  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Recientemente se han publicado datos sobre la taxonomía y ecología de las especies sorediosas de Menegazzia representadas en las regiones más australes de Chile y Argentina e islas del Atlántico Sur, además de registros esporádicos en zonas ubicadas más al norte en Chile. En este trabajo se discuten los patrones de distribución y la ecología del hábitat de 11 especies sorediosas, con especial enfásis en aquellas que se desarrollan al norte de los 48º S. Menega (more) zzia subpertusa, un epífito de arbustos esclerófilos, se registra por primera vez en América (Chile y Argentina). Menegazzia neozelandica tiene una distribución discontinua en Chile; ha sido recolectada en Fray Jorge (Cuarta Región de Chile), Islas Juan Fernández y en regiones costeras al sur de los 38º S. Menegazzia kawesqarica y M. tenuis son más frecuentes en las zonas más australes de Chile; también se han encontrado en hábitats de altura y bajas latitudes. Se incluyen, además, M. chrysogaster, M. fumarprotocetrarica, M. globulifera, M. magellanica, M. norsorediata, M. sanguinascens y M. wandae. Varias especies sorediosas crecen como pioneras en sustratos jóvenes. Los patrones de distribución a lo largo de gradientes de humedad y de luz son variables. Se presentan mapas de distribución y clave de las especies. Abstract in english ABSTRACT The taxonomy and ecology of the sorediate species of Menegazzia from the southernmost regions of Chile and Argentina and the South Atlantic Islands was recently published, only with sporadic reports from the more northern regions. In the present work the distribution patterns and habitat ecology of the sorediate species are discussed, with emphasis on the area north of 48º S. Eleven species are treated. Menegazzia subpertusa, an epiphyte of sclerophyll scrubs, i (more) s recorded from South America for the first time (Chile and Argentina). Menegazzia neozelandica has a disjunct distribution in Chile, with occurrences in Fray Jorge (Fourth Region of Chile) and on Islas Juan Fernández, and along the coast south of latitude 38º S. Menegazzia kawesqarica and M. tenuis are most common in the southernmost part of Chile, but are also found at high altitudes at lower latitudes. Additional treated species are M. chrysogaster, M. fumarprotocetrarica, M. globulifera, M. magellanica, M. norsorediata, M. sanguinascens and M. wandae. Several of the sorediate species are early colonisers of newly developed substrates. They show variable occurrences along light and humidity gradients. Distribution maps and a revised key are presented.

BJERKE, JARLE W; ELVEBAKK, ARVE; QUILHOT, WANDA

2003-03-01

127

Distribution and habitat ecology of the sorediate species of Menegazzia (Parmeliaceae, lichenized Ascomycota) in Chile Distribución y ecología de las especies sorediosas de Menegazzia (Parmeliaceae, Ascomycota liquenizado) en Chile  

Directory of Open Access Journals (Sweden)

Full Text Available ABSTRACT The taxonomy and ecology of the sorediate species of Menegazzia from the southernmost regions of Chile and Argentina and the South Atlantic Islands was recently published, only with sporadic reports from the more northern regions. In the present work the distribution patterns and habitat ecology of the sorediate species are discussed, with emphasis on the area north of 48º S. Eleven species are treated. Menegazzia subpertusa, an epiphyte of sclerophyll scrubs, is recorded from South America for the first time (Chile and Argentina). Menegazzia neozelandica has a disjunct distribution in Chile, with occurrences in Fray Jorge (Fourth Region of Chile) and on Islas Juan Fernández, and along the coast south of latitude 38º S. Menegazzia kawesqarica and M. tenuis are most common in the southernmost part of Chile, but are also found at high altitudes at lower latitudes. Additional treated species are M. chrysogaster, M. fumarprotocetrarica, M. globulifera, M. magellanica, M. norsorediata, M. sanguinascens and M. wandae. Several of the sorediate species are early colonisers of newly developed substrates. They show variable occurrences along light and humidity gradients. Distribution maps and a revised key are presented.Recientemente se han publicado datos sobre la taxonomía y ecología de las especies sorediosas de Menegazzia representadas en las regiones más australes de Chile y Argentina e islas del Atlántico Sur, además de registros esporádicos en zonas ubicadas más al norte en Chile. En este trabajo se discuten los patrones de distribución y la ecología del hábitat de 11 especies sorediosas, con especial enfásis en aquellas que se desarrollan al norte de los 48º S. Menegazzia subpertusa, un epífito de arbustos esclerófilos, se registra por primera vez en América (Chile y Argentina). Menegazzia neozelandica tiene una distribución discontinua en Chile; ha sido recolectada en Fray Jorge (Cuarta Región de Chile), Islas Juan Fernández y en regiones costeras al sur de los 38º S. Menegazzia kawesqarica y M. tenuis son más frecuentes en las zonas más australes de Chile; también se han encontrado en hábitats de altura y bajas latitudes. Se incluyen, además, M. chrysogaster, M. fumarprotocetrarica, M. globulifera, M. magellanica, M. norsorediata, M. sanguinascens y M. wandae. Varias especies sorediosas crecen como pioneras en sustratos jóvenes. Los patrones de distribución a lo largo de gradientes de humedad y de luz son variables. Se presentan mapas de distribución y clave de las especies.

JARLE W BJERKE; ARVE ELVEBAKK; WANDA QUILHOT

2003-01-01

128

Taxonomy and biology of Culex (Culex) maxi Dyar (Diptera: Culicidae) in South America  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Culex (Culex) maxi Dyar is described in the adult, pupal and larval stages, and the male genitalia and parts of the fourth-instar larva are illustrated. The larva is described for the first time. The paper includes a summary of available information on the taxonomy, bionomics and distribution of the species. The taxonomy and identification of the species are reviewed in light of current knowledge of the subgenus Culex in the New World.

Almirón, Walter R; Harbach, Ralph E

1996-10-01

129

Taxonomy and biology of Culex (Culex) maxi Dyar (Diptera: Culicidae) in South America  

Directory of Open Access Journals (Sweden)

Full Text Available Culex (Culex) maxi Dyar is described in the adult, pupal and larval stages, and the male genitalia and parts of the fourth-instar larva are illustrated. The larva is described for the first time. The paper includes a summary of available information on the taxonomy, bionomics and distribution of the species. The taxonomy and identification of the species are reviewed in light of current knowledge of the subgenus Culex in the New World.

Walter R Almirón; Ralph E Harbach

1996-01-01

130

Taxonomia e distribuição de Cheilolejeunea aneogyna (Spruce) A. Evans (Lejeuneaceae, Marchantiophyta) Taxonomy and distribution of Cheilolejeunea aneogyna (Spruce) A. Evans (Lejeuneaceae, Marchantiophyta)  

Directory of Open Access Journals (Sweden)

Full Text Available Cheilolejeunea aneogyna (Spruce) A. Evans é uma espécie sul americana, ocorrendo nas Florestas Amazônica e Atlântica. Caracteriza-se, principalmente, pela presença do segundo e primeiro dentes do lóbulo contíguos um ao outro e ausência de inovações. Entre as espécies neotropicais, C. aneogyna é a única que pode apresentar ocelos, porém, a presença destes não é constante. Descrição, ilustração, comentários sobre a morfologia e distribuição geográfica são fornecidos e discutidos. Está sendo referida pela primeira vez para a Bolívia.Cheilolejeunea aneogyna (Spruce) A. Evans is a South American species found in the Amazon and Atlantic Forest. It is characterized mainly by the presence of the first and second teeth of the lobule that are adjacent to each other and the lack of innovations. Among the neotropical species, C. aneogyna is the only one that has ocelli; however, their presence is not constant. A description, illustration, and comments on the morphology and geographic distribution are provided. This species is reported for the first time for Bolivia.

Cid José Passos Bastos

2012-01-01

131

Taxonomia e distribuição de Cheilolejeunea aneogyna (Spruce) A. Evans (Lejeuneaceae, Marchantiophyta)/ Taxonomy and distribution of Cheilolejeunea aneogyna (Spruce) A. Evans (Lejeuneaceae, Marchantiophyta)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Cheilolejeunea aneogyna (Spruce) A. Evans é uma espécie sul americana, ocorrendo nas Florestas Amazônica e Atlântica. Caracteriza-se, principalmente, pela presença do segundo e primeiro dentes do lóbulo contíguos um ao outro e ausência de inovações. Entre as espécies neotropicais, C. aneogyna é a única que pode apresentar ocelos, porém, a presença destes não é constante. Descrição, ilustração, comentários sobre a morfologia e distribuição geográfica são fornecidos e discutidos. Está sendo referida pela primeira vez para a Bolívia. Abstract in english Cheilolejeunea aneogyna (Spruce) A. Evans is a South American species found in the Amazon and Atlantic Forest. It is characterized mainly by the presence of the first and second teeth of the lobule that are adjacent to each other and the lack of innovations. Among the neotropical species, C. aneogyna is the only one that has ocelli; however, their presence is not constant. A description, illustration, and comments on the morphology and geographic distribution are provided. This species is reported for the first time for Bolivia.

Bastos, Cid José Passos

2012-09-01

132

Taxonomy of the extrasolar planet.  

UK PubMed Central (United Kingdom)

When a star is described as a spectral class G2V, we know that the star is similar to our Sun. We know its approximate mass, temperature, age, and size. When working with an extrasolar planet database, it is very useful to have a taxonomy scale (classification) such as, for example, the Harvard classification for stars. The taxonomy has to be easily interpreted and present the most relevant information about extrasolar planets. I propose an extrasolar planet taxonomy scale with four parameters. The first parameter concerns the mass of an extrasolar planet in the form of units of the mass of other known planets, where M represents the mass of Mercury, E that of Earth, N Neptune, and J Jupiter. The second parameter is the planet's distance from its parent star (semimajor axis) described in a logarithm with base 10. The third parameter is the mean Dyson temperature of the extrasolar planet, for which I established four main temperature classes: F represents the Freezing class, W the Water class, G the Gaseous class, and R the Roasters class. I devised one additional class, however: P, the Pulsar class, which concerns extrasolar planets orbiting pulsar stars. The fourth parameter is eccentricity. If the attributes of the surface of the extrasolar planet are known, we are able to establish this additional parameter where t represents a terrestrial planet, g a gaseous planet, and i an ice planet. According to this taxonomy scale, for example, Earth is 1E0W0t, Neptune is 1N1.5F0i, and extrasolar planet 55 Cnc e is 9E-1.8R1.

Plávalová E

2012-04-01

133

Skeletonema potamos (Bacillariophyta) in Patos Lagoon, southern Brazil: Taxonomy and distribution Skeletonema potamos (Bacillariophyta) en la Laguna dos Patos, sur del Brasil: Taxonomía y distribución  

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Full Text Available We analyzed the morphogical features of the centric diatom Skeletonema potamos (Weber) Hasle from Patos Lagoon, southern Brazil, using light and scanning electron microscopy. We discuss the abundance and dis- tribution of the species along the salinity gradient in the lagoon. Samples from the water surface were taken monthly at eight stations along the longitudinal axis of the lagoon, from December 1987 to December 1988. The species were counted by the Utermöhl method, and the density (cells.mL-1) was estimated based on live cells. The morphology of the specimens agrees with the type, from the Little Miami River, Ohio, U.S.A., except for the convexity and the pattern of granules on the valve face. Skeletonema potamos was found in the winter and spring, and was distributed in the limnetic, oligohaline and mesohaline zones of the lagoon. The cell con- centration appeared to be controlled by the salinity, with a significant negative correlation observed. Light and competition probably also influence the development of S. potamos populations in the Patos Lagoon.En el presente trabajo analizamos las características morfológicas de la diatomea céntrica Skeletonema pota- mos (Weber) Hasle de la Laguna dos Patos, sur del Brasil, usando microscopia de luz y electrónica de barrido. Discutimos la abundancia y la distribución de la población a lo largo del gradiente de salinidad en la laguna. Las muestras de la superficie del agua fueron recogidas mensualmente en ocho estaciones a lo largo del eje longitudinal de la laguna, en el periodo de diciembre 1987 a diciembre 1988. Las muestras fueron contadas por el método de Utermöhl, y la densidad (cels.mL-1) estimada en base de las células vivas. La morfología de los individuos concuerda con la especie-tipo del río Little Miami, localizado en Ohio, USA, a excepción de la convexidad y del patrón de gránulos en la cara valvar. Skeletonema potamos fue encontrada en el invierno y primavera, y distribuida en las zonas limnéticas, oligohalina y mesohalina de la laguna. La densidad de la po- blación presenta una correlación negativa significativa con la salinidad. La luz y la competencia probablemente también influencian el desarrollo de las poblaciones de la especie S. potamos en la Laguna dos Patos.

Lezilda Carvalho Torgan; Vanessa Becker; Cristiane Bahi dos Santos

2011-01-01

134

ASPECTOS ECOLÓGICOS Y DISTRIBUCION GEOGRÁFICA DE CARRANGENOPHYTAS/ CARRAGENOPHYTAS ECOLOGICAL ASPECTS AND GEOGRAPHICAL DISTRIBUTION  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Las especies carragenófitas están definidas como macroalgas miembro del Phylum Rodophyta, Clase Rodophyceae, Subclase Florideophycidae, Orden Gigartinales. Las especies de mayor importancia comercial a nivel internacional son de los géneros Betaphycus, Eucheuma y Kappaphycus; y a nivel nacional especies de los géneros Gigartina, Mazzaella y Sarcothalia. Debido a su importancia comercial, el género Gigartina, ha sido objeto de investigaciones como: Ecología de las po (more) blaciones de las costas estuarinas y abiertas de la especie del noreste del Atlántico; ha sido investigado por Mathieson y Tveter (1976) con relación a las cantidades y calidad de su carragenina. Estudios de las respuestas a fotoperíodos (Guiry, 1984; Guiry et al., 1984) han identificado "ventanas" reproductivas, sugiriendo que las explicaciones de multiplicación vegetativa son cada vez más exclusivas, a diferencia de la producción y gametangial o tetrasporangial, en las poblaciones de las altas latitudes de una especie europea generalizada. La determinación genética de los patrones de ramificación y límites de tolerancia a la temperatura se han establecido para varias especies de (Guiry et al., 1987.; Buschmann, 2001). La viabilidad del cultivo de especies en sustratos artificiales ha sido evaluada por Mumford y Waaland (1980), y demostró tener potencial comercial. Este género tiene distribución en todo el mundo en mares templados a fríos, sin embargo, muy pocas especies ocurren en las regiones subtropicales. Los centros de diversidad de especies particularmente rica son California, Japón, Nueva Zelanda, Chile y Sudáfrica (Guiry, M.D & Guiry, G.M. 2011). Abstract in english The carragenophytas species are defined as macro-algae, members of the Phylum Rodophyta, Rodophyceae Class, Florideophycidae Subclass, Gigartinales Order. The most important commercial species at the international level are the Betaphycus, Eucheuma and Kappaphycus genera and at the national level the species belonging to the Gigartina, Mazzaella and Sarcothalia genera. Because of its commercial importance, the Gigartina genus has been the object of investigations such as: (more) Ecology of populations in estuaries and open coast in the North-East Atlantic species; it has been studied by Mathieson and Tveter (1976) in relation with its carragenine quantity and quality. Studies about the response to photoperiods (Guiry, 1984; Guiry et al., 1984) have identified reproductive "windows" suggesting that the explanations for vegetative multiplication are more exclusive each time, different from gametangial or tetra-sporangial production in populations of high latitudes from a generalized European species. Genetic determination of ramification patterns and tolerance limits to temperature has been established for several species (Guiry et al., 1987; Buschmann, 2001). Species cultivation viability in artificial substrates has been evaluated by Mumford y Waaland (1980), and it showed commercial potential. This genus has distribution worldwide in warm and cold seas. However, very few species happen in subtropical regions. The particularly rich species biodiversity centers are California, Japan, New Zealand, Chile y South Africa (Guiry, M.D & Guiry, G.M. 2011).

SALAZAR SÁNCHEZ, MARGARITA DEL R.; SALAZAR SÁNCHEZ, RAÚL A.

2012-12-01

135

LEADERSHIP BEHAVIORAL TAXONOMIES IN UNIVERSITIES  

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Full Text Available The study was intended to recognize and replicate the Yukl’s (1989-2004) behavioral taxonomies in the university settings in Sindh. A comprehensive questionnaire based on the items in taxonomies was developed, face validity of the questionnaire was test and found suitable. A total of 90 university Deans and head of Departments were randomly selected from public and private universities of Sindh. Categorical reliability of the data was checked and found highly reliable. The majority of the respondents were male, post graduate, above 50 years of age, married and had more than 15 years of experience. The statistical analysis describes the typical Sindhi culture among the respondents. A large number of university leadership focused on the relation as compared to task and change at the universities. This research also supports partial replication of three dimensions i.e., Relation, Task and Change as Yukl’s behavioral taxonomies with first order factor analysis. Relation factor was replicated completely, while other two were replicated in two different facets each i.e., Change was replicated in two facets – Improvement and Process and Task was also replicated in two facets – Improvement and Process. Making a second order factor analysis assured these two factors were replicated completely.

Riaz Ahmed Mangi; Asad Raza Abidi; Hasan Jawad Soomro; Ikhtiar Ali Ghumro; Amanat Ali Jalbani

2011-01-01

136

Ecological Ordination and Distribution of Hygrophilous Species Growing on a Mediterranean Riverbank (SW Spain)  

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Full Text Available The Guadiamar riverbanks are home to riparian plant communities, such as alder, poplar and ash forests, tamujares, salt marshes,reed beds, etc. characteristic of Mediterranean rivers. A data set of these communities, including floristic relevés and environmentalvariables (physical and chemical soil properties, bioclimate) was analysed to correlate their floristic composition/species distributionwith environmental variables. By means of an RDA (redundancy analysis) and a complementary cluster analysis four groups of specieswere discriminated according to their ecological requirements. The RDA displayed three major, parallel-running gradients (i.e., textural,bioclimatic and chemical) in environmental variables. Other less conspicuous, crossed gradients revealed the impact of man-madealterations, particularly in the middle reaches of the river. The results can be helpful in the planning of future ecologically orientedrestoration programmes of wetlands.

Francisco GOMEZ MERCADO; Esther GIMENEZ LUQUE; Enrique LOPEZ CARRIQUE; Sergio DE HARO LOZANO; Fernando DEL MORAL TORRES

2012-01-01

137

Evaluating a Bayesian approach to improve accuracy of individual photographic identification methods using ecological distribution data  

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Full Text Available Photographic identification of individual organisms can be possible from natural body markings. Data from photo-ID can be used to estimate important ecological and conservation metrics such as population sizes, home ranges or territories. However, poor quality photographs or less well-studied individuals can result in a non-unique ID, potentially confounding several similar looking individuals. Here we present a Bayesian approach that uses known data about previous sightings of individuals at specific sites as priors to help assess the problems of obtaining a non-unique ID. Using a simulation of individuals with different confidence of correct ID we evaluate the accuracy of Bayesian modified (posterior) probabilities. However, in most cases, the accuracy of identification decreases. Although this technique is unsuccessful, it does demonstrate the importance of computer simulations in testing such hypotheses in ecology.

Richard Stafford; Jane R. Lloyd

2011-01-01

138

Inventorying of the tree fern Genus Cibotium of Sumatra: Ecology, population size and distribution in North Sumatra  

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Full Text Available Praptosuwiryo TNg, Pribadi DO, Puspitaningtyas DM, Hartini S (2011) Inventorying the tree fern Genus Cibotium of Sumatra: Ecology, population size and distribution in North Sumatra. Biodiversitas 12: 204-211. Cibotium is one tree fern belongs to the family Cibotiaceae which is easily differentiated from the other genus by the long slender golden yellowish-brown smooth hairs covered its rhizome and basal stipe with marginal sori at the ends of veins protected by two indusia forming a small cup round the receptacle of the sorus. It has been recognized as material for both traditional and modern medicines in China, Europe, Japan and Southeast Asia. Population of Cibotium species in several countries have decreased rapidly because of over exploitation and there is no artificial cultivation until now. The aims of this study were: (i) To re-inventory the species of Cibotiun in North Sumatra, (ii) to record the ecology and distribution of each species, and (iii) to assess the population size of each species. Field study was carried out by using random search with belt transect. Two species were recorded, namely C. arachnoideum dan C. barometz. The geographical distribution of the two species in North Sumatra are presented. Cibotium is commonly growing terrestrially on opened or rather opened areas in secondary forets and primary forest at hills or lower mountains with a relatively high humidity at 30-90º slopes. C. arachnoideum has a strict distribution and only found at 1740-1770 m a.s.l. in primary forest, whereas C. barometz has a broad distribution in secondary forest at elevation range from 650-1200 m.

TITIEN NGATINEM PRAPTOSUWIRYO; DIDIT OKTA PRIBADI; DWI MURTI PUSPITANINGTYAS; SRI HARTINI

2011-01-01

139

Improving ecological risk assessment by including bioavailability into species sensitivity distributions: An example for plants exposed to nickel in soil  

International Nuclear Information System (INIS)

The variability of species sensitivity distribution (SSD) due to contaminant bioavailability in soil was explored by using nickel as metal of concern. SSDs of toxicity test results of Avena sativa L. originating from different soils and expressed as total content and available (0.01 M CaCl2) extractable concentration were compared to SSDs for terrestrial plants derived from literature toxicity data. Also the 'free' nickel (Ni2+) concentration was calculated and compared. The results demonstrated that SSDs based on total nickel content highly depend on the experimental conditions set up for toxicity testing (i.e. selected soil and pH value) and thus on metal bioavailability in soil, resulting in an unacceptable uncertainty for ecological risk estimation. The use in SSDs of plant toxicity data expressed as 0.01 M CaCl2 extractable metal strongly reduced the uncertainty in the SSD curve and thus can improve the ERA procedure remarkably by taking bioavailability into account. - The use of bioavailability toxicity data can improve species sensitivity distribution (SSD) curves and thus ecological risk assessment (ERA).

2007-01-01

140

MURCIÉLAGOS DE UN BOSQUE EN LOS ANDES CENTRALES DE COLOMBIA CON NOTAS SOBRE SU TAXONOMÍA Y DISTRIBUCIÓN Bats from a forest in the Central Andes of Colombia with notes on their taxonomy and distribution  

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Full Text Available Se presenta la diversidad de murciélagos registrados en un inventario rápido en tres estaciones entre los 2500 y los 3500 m de altitud, sobre la vertiente occidental de la cordillera Central de los Andes colombianos, en el departamento de Caldas. El gradiente de distribución de Anoura aequatoris es ampliado hacia el norte y se sugiere su presencia en otras localidades más septentrionales de la cordillera Central y la Cordillera Oriental. Sturnira aratathomasi, S. erythromos y S. ludovici, fueron capturadas en simpatría mientras que Histiotus montanus e H. humboldti se registraron en estaciones diferentes. Myotis keaysi presentó el gradiente altitudinal más amplio, mientras Carollia brevicauda estuvo restringida a la estación de menor altitud. Los géneros Anoura, Sturnira e Histiotus presentan un patrón de sucesión o reemplazo altitudinal de especies. Considerando la confusión en la identificación de las especies registradas, se presentan comentarios sobre la diferenciación entre ellas y recomendaciones para estudios futuros sobre su taxonomía y distribución. La certeza taxonómica es importante para conocer el estado real de las poblaciones colombianas de murciélagos e identificar patrones básicos para interpretar procesos importantes dentro de los ecosistemas y su estado de conservación. Por el contrario, la información errada, puede implicar consecuencias inmensurables cuando es utilizada y los errores replicados.This paper reports the bat diversity found in a rapid assessment inventory in three stations between 2500 and 3500 masl, along the western slopes of the cordillera Central of Colombia (Departmento of Caldas). The distributional range of Anoura aequatoris is expanded northwards and its presence in more western localities of the the cordillera Central and the Oriental is suggested. Sturnira aratathomasi, S. erythromos and S. ludovici were captured in sympatry while Histiotus montanus and H. humboldti were recorded in different stations. Myotis keaysi showed the broadest altitudinal range, while Carollia brevicauda was only found in the station at lowest elevation. The genera Anoura, Sturnira and Histiotus have a pattern of altitudinal succession or replacement of species. Considering the difficulty to identify the recorded species, comments on their taxonomy and recommendations for future studies are included. Taxonomic accuracy is important to know the real status of the Colombian populations of bats and to identify basic biological patterns that allow us to interpret processes within ecosystems and their conservation status; using wrong information and repeating mistakes might bring immeasurable consequences.

MIGUEL E. RODRÍGUEZ-POSADA

2010-01-01

 
 
 
 
141

Pinnularia (Bacillariophyta) do curso inferior do rio Negro, Amazonas, Brasil: taxonomia e distribuição temporal/ Pinnularia (Bacillariophyta) from the lower course of Negro river (Amazon, Brazil): taxonomy and temporal distribution  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este estudo relata a taxonomia e distribuição temporal do gênero Pinnularia ocorrente no curso inferior do rio Negro (03º02'46,5"S e 60º15'13,1"W) ao longo de um ciclo anual. O trabalho foi conduzido a partir da análise de amostras coletadas na coluna d'água, em escala mensal, entre os meses de outubro de 2002 a setembro de 2003. As espécies foram descritas e comentadas com base na sua morfologia e morfometria. Onze espécies e quatro variedades foram identificada (more) s, ilustradas e incluídas em chave taxonômica. Dois táxons registrados neste estudo, P. sterrenburgii var. sterrenburgii Metzeltin & Lange-Bertalot e P. subgibba var. capitata Metzeltin & Krammer, constituem primeira citação de ocorrência para o rio Negro. Temporalmente, a maior riqueza de espécies ocorreu entre os meses de outubro a dezembro de 2002, período de águas baixas, quando houve provavelmente maior interação entre água e sedimento possibilitando aporte de indivíduos da região bentônica. Considerando a ocorrência dos táxons ao longo do estudo, somente P. confirma foi considerada frequente, estando presente em mais de 50% das amostras analisadas. Abstract in english This study reports the taxonomy and temporal distribution of the Pinnularia genus occurring in the lower course Negro river (03º02'46,5"S e 60º15'13,1"W) along an annual cycle. Samples were collected in the water column monthly, from October 2002 to September 2003. The species were described and commented based on their morphology and morphometry. Eleven species and four varieties are registered, illustrated and incorporated in a taxonomic key. P. sterrenburgii var. ste (more) rrenburgii Metzeltin & Lange-Bertalot and P. subgibba var. capitata Metzeltin & Krammer are the first references to Negro river. Temporally, the highest species richness occurred from October and December 2002, low water period, when happened more interaction between water and sediment, and the contribution of the benthos individuals. On base in taxa occurrence during this study, only P. confirma was frequently, with occurrence in more than 50% of sample analyzed.

Pereira, Andreia Cavalcante; Torgan, Lezilda Carvalho; Melo, Sérgio

2012-09-01

142

Taxonomy and distribution of phlebotomine sandflies in Venezuela: II. The subgenus Trichopygomyia of the genus Lutzomyia (Diptera: Psychodidae) Taxonomía y distribución geográfica de los flebótomos en Venezuela: II. El Subgénero Trichopygomyia del género Lutzomyia (Diptera: Psychodidae)  

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Full Text Available Species of sandflies in the subgenuys Trichopygomyia of the genus Lutzomyia occurring in Venezuela are reviewd. A new species, Lutzomyia pinna n. sp. is described. A distribution map and a pictorial key for maleds are provided with remarks on the ecological data collected in Venezuela.Se hace una revisión de las especies de flebótomos del género Trichopygomyia, registradas hasta el presente en Venezuela. Se describe un nuevo taxon, Lutzomyia pinna n. sp. elevándose a 4 el número de especies conocidas para el País: L. conviti, L. longispina, L. wagleyi y L. pinna n. sp. Se proporciona una clave gráfica para los machos y un mapa de distribución geográfica de estas especies en Venezuela.

M. Dora Feliciangeli

1989-01-01

143

Ecology, biology and distribution of spotted-fever tick vectors in Brazil.  

Science.gov (United States)

Spotted-fever-caused Rickettsia rickettsii infection is in Brazil the major tick-borne zoonotic disease. Recently, a second and milder human rickettsiosis caused by an agent genetically related to R. parkeri was discovered in the country (Atlantic rainforest strain). Both diseases clearly have an ecological background linked to a few tick species and their environment. Capybaras (Hydrochoerus hydrochaeris) and Amblyomma cajennense ticks in urban and rural areas close to water sources are the main and long-known epidemiological feature behind R. rickettsii-caused spotted-fever. Unfortunately, this ecological background seems to be increasing in the country and disease spreading may be foreseen. Metropolitan area of São Paulo, the most populous of the country, is embedded in Atlantic rainforest that harbors another important R. rickettsii vector, the tick Amblyomma aureolatum. Thus, at the city-forest interface, dogs carry infected ticks to human dwellings and human infection occurs. A role for R. rickettsii vectoring to humans of a third tick species, Rhipicephalus sanguineus in Brazil, has not been proven; however, there is circumstantial evidence for that. A R. parkeri-like strain was found in A. ovale ticks from Atlantic rainforest and was shown to be responsible for a milder febrile human disease. Rickettsia-infected A. ovale ticks are known to be spread over large areas along the Atlantic coast of the country, and diagnosis of human infection is increasing with awareness and proper diagnostic tools. In this review, ecological features of the tick species mentioned, and that are important for Rickettsia transmission to humans, are updated and discussed. Specific knowledge gaps in the epidemiology of such diseases are highlighted to guide forthcoming research. PMID:23875178

Szabó, Matias P J; Pinter, Adriano; Labruna, Marcelo B

2013-07-12

144

Ecology, biology and distribution of spotted-fever tick vectors in Brazil  

Science.gov (United States)

Spotted-fever-caused Rickettsia rickettsii infection is in Brazil the major tick-borne zoonotic disease. Recently, a second and milder human rickettsiosis caused by an agent genetically related to R. parkeri was discovered in the country (Atlantic rainforest strain). Both diseases clearly have an ecological background linked to a few tick species and their environment. Capybaras (Hydrochoerus hydrochaeris) and Amblyomma cajennense ticks in urban and rural areas close to water sources are the main and long-known epidemiological feature behind R. rickettsii-caused spotted-fever. Unfortunately, this ecological background seems to be increasing in the country and disease spreading may be foreseen. Metropolitan area of São Paulo, the most populous of the country, is embedded in Atlantic rainforest that harbors another important R. rickettsii vector, the tick Amblyomma aureolatum. Thus, at the city–forest interface, dogs carry infected ticks to human dwellings and human infection occurs. A role for R. rickettsii vectoring to humans of a third tick species, Rhipicephalus sanguineus in Brazil, has not been proven; however, there is circumstantial evidence for that. A R. parkeri-like strain was found in A. ovale ticks from Atlantic rainforest and was shown to be responsible for a milder febrile human disease. Rickettsia-infected A. ovale ticks are known to be spread over large areas along the Atlantic coast of the country, and diagnosis of human infection is increasing with awareness and proper diagnostic tools. In this review, ecological features of the tick species mentioned, and that are important for Rickettsia transmission to humans, are updated and discussed. Specific knowledge gaps in the epidemiology of such diseases are highlighted to guide forthcoming research.

Szabo, Matias P. J.; Pinter, Adriano; Labruna, Marcelo B.

2013-01-01

145

A Taxonomy of College Writing Styles.  

Science.gov (United States)

This paper advances a taxonomy of college writing styles based on a broad spectrum of writing research. The taxonomy focuses on the constructs of deep and surface writing and the role of selfhood in affecting writing strategies and outcomes. It compares constructs such as reflective versus reproductive, hierarchical versus linear, active versus…

Lavelle, Ellen

146

Changing distributions of larger ungulates in the Kruger National Park from ecological aerial survey data  

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Full Text Available Documenting current species distribution patterns and their association with habitat types is important as a basis for assessing future range shifts in response to climate change or other influences. We used the adaptive local convex hull (a-LoCoH) method to map distribution ranges of 12 ungulate species within the Kruger National Park (KNP) based on locations recorded during aerial surveys (1980–1993). We used log-linear models to identify changes in regional distribution patterns and chi-square tests to determine shifts in habitat occupation over this period. We compared observed patterns with earlier, more subjectively derived distribution maps for these species. Zebra, wildebeest and giraffe distributions shifted towards the far northern section of the KNP, whilst buffalo and kudu showed proportional declines in the north. Sable antelope distribution contracted most in the north, whilst tsessebe, eland and roan antelope distributions showed no shifts. Warthog and waterbuck contracted in the central and northern regions, respectively. The distribution of impala did not change. Compared with earlier distributions, impala, zebra, buffalo, warthog and waterbuck had become less strongly concentrated along rivers. Wildebeest, zebra, sable antelope and tsessebe had become less prevalent in localities west of the central region. Concerning habitat occupation, the majority of grazers showed a concentration on basaltic substrates, whilst sable antelope favoured mopane-dominated woodland and sour bushveld on granite. Buffalo showed no strong preference for any habitats and waterbuck were concentrated along rivers. Although widespread, impala were absent from sections of mopane shrubveld and sandveld. Kudu and giraffe were widespread through most habitats, but with a lesser prevalence in northern mopane-dominated habitats. Documented distribution shifts appeared to be related to the completion of the western boundary fence and widened provision of surface water within the park. Conservation implications: The objectively recorded distribution patterns provide a foundation for assessing future changes in distribution that may take place in response to climatic shifts or other influences.

George J. Chirima; Norman Owen-Smith; Barend F.N. Erasmus

2012-01-01

147

Pre- and post-IRAS asteroid taxonomies  

Science.gov (United States)

Two asteroid taxonomies, proposed on the basis of a statistical analysis of a wide sample of asteroids, are discussed: the pre-IRAS Tholen (1984) taxonomy, and the first post-IRAS taxonomy proposed by Barucci et al. (1987). The Tholen's taxonomy is based on the analysis of 589 asteroids, described by seven color indices, while the Barucci et al. analysis (of 438 asteroids) uses the IRAS albedo values as well as the seven color indices. Both taxonomies define eight asteroid types (S, C, D, A, E, B, M, and G) and show some differences in the subtypes. This paper shows that some of these differences are intrinsic to the used clustering techniques and some depend on the authors' attitude in reading the results.

Barucci, M. A.; Fulchignoni, M.

148

[The influence of ecological hygiene environmental factors on the distributIon of respiratory diseases in population of Primorskii Krai].  

UK PubMed Central (United Kingdom)

Conducted Ecological hygienic assessment of the incidence of respiratory diseases in bioclimatic zones has been performed. The study of the incidence was conducted with the use of the classical methods of analysis of data such as descriptive statistics, chi-square test, correlation and regression analysis. The study found that respiratory diseases occupy 30%, 47% and 61% in the structure of the incidence in adults, adolescents and children correspondingly. Constructed predictive models describe the tendency of increasing incidence in adolescents and children. The morbidity of environmentally dependent respiratory pathology in residents of different regions of Primorye Territory was found to be dependent on the characteristics of bioclimatic zones and combinations of parameters forming these areas. Factors of bioclimatic character: living in an area of high humidity, temperature swings and the weather travel have the most influence on the level of respiratory diseases in childhood. Iindices of morbidity rate in adolescent achieve those in adult population, that indicates on the immaturity of the adaptation system of adolescent organism to adverse environmental factors.

Kiku PF; Izma?lova OA; Gorborukova TV; Anan'ev VIu

2012-09-01

149

Ecological composition and distribution of the diatoms from the Laguna Superior, Oaxaca, Mexico.  

UK PubMed Central (United Kingdom)

A taxonomic study of diatoms was carried out in a tropical coastal lagoon. Material for this study consists of water samples obtained from February-March 1992 to November-December 2000. Qualitative and quantitative analyses showed the presence of 373 taxa of which the families Bacillariaceae (67 species) and Chaetocerotaceae (37 species) were the most abundant groups. The species Skeletonema costatum, Chaetoceros curvisetus, Coscinodiscus radiatus var. radiatus, Ditylum brightwellii, Thalassiosira eccentrica and Entomoneis alata were found associated with moderate water quality and forming blooms. In addition, a regional comparison between Mexico and South America of the identified species is given. For practical handling, indicative values obtained from their ecological composition are incorporated as well as a code of the floristic list. Achecklist of the species and their occurrence are given.

Moreno-Ruiz JL; Tapia-Garcia M; Licea S; Figueroa-Torres MG; Esquivel A; Herrera-Galindo JE; González-Fernández JM; González-Macias Mdel C

2011-07-01

150

Parasite communities and feeding ecology of the European sprat (Sprattus sprattus L.) over its range of distribution.  

UK PubMed Central (United Kingdom)

The metazoan parasite fauna and feeding ecology of 165 Sprattus sprattus (L., 1758) was studied from different geographic regions (Baltic Sea, North Sea, English Channel, Bay of Biscay, Mediterranean Sea). A total of 13 metazoan parasite species were identified including six Digenea, one Monogenea, two Cestoda, two Nematoda and two Crustacea. Didymozoidae indet., Lecithocladium excisum and Bomolochidae indet. represent new host records. The parasite species richness differed according to regions and ranged between 3 and 10. The most species-rich parasite fauna was recorded for sprats from the Bay of Biscay (North Atlantic), and the fishes from the Baltic Sea contained the lowest number of parasite species. More closely connected geographical regions, the North Sea, English Channel and Bay of Biscay, showed more similar parasite component communities compared with more distant regions. From the examined stomachs of S. sprattus, a total of 11 different prey items were identified, including Mollusca, Annelida, Crustacea and Tunicata. The highest number of prey organisms belonged to the crustaceans. The variety of prey items in the stomach was reflected by the parasite community differences and parasite species richness from the different regions. The feeding ecology of the fish at the sampled localities was responsible for the observed parasite composition and, secondarily, the zoogeographical distribution of the parasites, questioning the use of the recorded sprat parasites as biological indicators for environmental conditions and change.

Kleinertz S; Klimpel S; Palm HW

2012-03-01

151

Ecological significance of assimilate distribution in Agropyron repens clones under influence of the copper smelter Legnica  

Directory of Open Access Journals (Sweden)

Full Text Available The studies on couch grass (Agropyron repens (L.) P. Beauv.) populations growing in stress conditions in close vicinity of a copper smelter concern the integrity of clonal structure. The connections of tillers within a clone and the interclonal integrity was investigated by means of assimilate translocation, using 14C. It was found that heavy metal stress affects the phenotypic plasticity of couch grass in regard to clonal growth of the phalanx type. The phalanx type growth is supported by a considerable integration, which allows the redistribution of resources, through internal routes, from places rich in resources to such clone parts, which cover a surface poor in nutritive compounds. In an unpolluted (control) couch grass population representing the guerilla type of growth, the translocation of assimilates concerns only the closest (sister) ramets. The phalanx type of growth in couch grass subjected to contamination favours also the accumulation of organic matter and macronutrients (N, Ca) in zones of occurrence of Agropyron repens clusters, which are in deficit in areas close to the smelter. The irregular accumulation of heavy metals and the deficit of macronutrients in soil, form near the smelter a patchy environment. In this patchy environment couch grass, as one of few plants, finds appropriate conditions for foraging. The whole of factors in the studied polluted area creates a unique dynamic system between couch grass clones and the local ecological conditions.

Teresa Brej

2001-01-01

152

Ecological distribution of Cyanophyceae in lotic ecosystems of São Paulo State  

Directory of Open Access Journals (Sweden)

Full Text Available A hundred seventy two stream reaches from six distinct natural regions (parts of biomes or geological areas) in São Paulo State (Atlantic Rainforest, Cerrado, Hard Water regions, Northwest region, Subtropical Rainforest, and Tropical Rainforest) were searched for the most representative macroscopic Cyanophyceae of phytobenthic communities. Selected ecological parameters were analyzed in each stream segment: conductance, current velocity, oxygen saturation, pH, turbidity, and water temperature. Algal abundance was evaluated as percentage cover. Thirthy four cyanophyte taxa were identified and Phormidium retzii was the most widespread species throughout the State, occurring in all studied regions, except in hard water areas, and was negatively correlated to conductance. The subtropical Rainforest region presented the highest mean species richness per site, whereas the tropical Rainforest region had the highest abundance (percentage cover) of blue-green algae. Correlation tests revealed that conductance was significantly and negatively related to variations in abundance and richness of cyanophyte in streams of São Paulo State. This relationship probably reflects the ability of blue-green algae to grow at medium to low ion content and to take advantage under nutrient stress conditions.

BRANCO LUIS HENRIQUE Z.; NECCHI JÚNIOR ORLANDO; BRANCO CIRO CESAR Z.

2001-01-01

153

Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory  

Energy Technology Data Exchange (ETDEWEB)

Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

2008-10-01

154

Distribution and Ecological Range of the Alien Plant Species Mikania micrantha Kunth (Asteraceae) in Taiwan  

Directory of Open Access Journals (Sweden)

Full Text Available In the past two decades Mikania micrantha Kunth, a climbing plant species originating from tropicalAmerica, has spread across Taiwan. It can now be found frequently in the lowlands and lower mountain areasup to 1,000 m a.s.l. in the centre and south of the island. Mikania micrantha is considered a problematic invasivealien plant species which is said to cause economical as well as environmental damage. This study investigatedthe ecological site characteristics of M. micrantha in Taiwan. 112 vegetation surveys were carried out in habitatswhere the alien plant was present. A comparison between sites with a high and a low abundance was carriedout in order to assess which factors especially influence the extensive spread of the plant. Furthermore, theinfluence of disturbances was examined. Results showed that Mikania micrantha grows very dense in habitatswhich are characterized by good light conditions combined with vertical structures, such as trees. Resultsrevealed that this invader occurs most frequently in agricultural fallows and wastelands, but it could hardly befound in the intensively managed plantations in the investigation area. Results provide great evidence that theplant is strongly influenced by disturbances, but only if impacts occur rarely.

Willis, Maja; Stefan Zerbe; Yau-Lun Kuo

2008-01-01

155

A Taxonomy for Radio Location Fingerprinting  

DEFF Research Database (Denmark)

Location Fingerprinting (LF) is a promising location technique for many awareness applications in pervasive computing. However, as research on LF systems goes beyond basic methods there is an increasing need for better comparison of proposed LF systems. Developers of LF systems are also lacking good frameworks for understanding different options when building LF systems. This paper proposes a taxonomy to address both of these problems. The proposed taxonomy has been constructed from a literature study of 51 papers and articles about LF. For researchers the taxonomy can also be used as an aid when scoping out future research in the area of LF.

Kjærgaard, Mikkel Baun

2007-01-01

156

Distribution and ecological conditions of Posidonia oceanica (L.) Delile meadows in La Maddalena National Park (Sardinia)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The La Maddalena Archipelago became National Park in 1996 and together with the southern part of Corsica it forms the Bocche di Bonifacio International Park. Posidonia oceanica beds widely distributed in the area play an important role in dividing La Maddalena National Park (MNP) into zones w...

Cossu, Andrea Vito Luigi; Ragazzola, Federica; Demelas, Simone

157

Distribution, abundance and ecological relevance of pelagic fishes in the Lazarev Sea, Southern Ocean  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The distribution and abundance of larval and postlarval fishes was investigated in the Lazarev Sea, Southern Ocean, in March and April 2004. The upper 200 m of the water column were sampled with an 8 m2 rectangular midwater trawl at 93 stations. The larval species community clustered in a diverse co...

Flores, H.; Van De Putte, A.P.; Siegel, V.; Pakhomov, E.A.; van Franeker, J.A.; Meesters, H.W.G.; Volckaert, F.A.M.J.

158

Distribution and ecological risk of organochlorine pesticides and polychlorinated biphenyls in sediments from the Mediterranean coastal environment of Egypt.  

UK PubMed Central (United Kingdom)

Organochlorine contamination in the Mediterranean coastal environment of Egypt was assessed based on 26 surface sediments samples collected from several locations on the Egyptian coast, including harbors, coastal lakes, bays, and estuaries. The distribution and potential ecological risk of contaminants is described. Organochlorine compounds (OCs) were widely distributed in the coastal environment of Egypt. Concentrations of PCBs, DDTs, and chloropyrifos ranged from 0.29 to 377ngg(-1) dw, 0.07 to 81.5ngg(-1) dw, and below the detection limit (DL) to 288ngg(-1) dw, respectively. Other organochlorinated pesticides (OCP) studied were 1-2 orders of magnitude lower. OCP and PCBs had higher concentrations at Burullus Lake, Abu Qir Bay, Alexandria Eastern Harbor, and El Max Bay compared to other sites. OCP and PCB contamination is higher in the vicinity of possible input sources such as shipping, industrial activities and urban areas. PCB congener profiles indicated they were derived from more than one commercially available mixture. The ratios of commercial chlordane and heptachlor metabolites indicate historical usage; however, DDT and HCHs inputs at several locations appear to be from recent usage. The concentrations of PCBs and DDTs are similar to those observed in sediments from coastal areas of the Mediterranean Sea. Ecotoxicological risk from DDTs and PCBs is greatest in Abu Qir Bay, Alexandria Harbor, and El-Max Bay.

Barakat AO; Mostafa A; Wade TL; Sweet ST; El Sayed NB

2013-09-01

159

Distribution and ecological risk of organochlorine pesticides and polychlorinated biphenyls in sediments from the Mediterranean coastal environment of Egypt.  

Science.gov (United States)

Organochlorine contamination in the Mediterranean coastal environment of Egypt was assessed based on 26 surface sediments samples collected from several locations on the Egyptian coast, including harbors, coastal lakes, bays, and estuaries. The distribution and potential ecological risk of contaminants is described. Organochlorine compounds (OCs) were widely distributed in the coastal environment of Egypt. Concentrations of PCBs, DDTs, and chloropyrifos ranged from 0.29 to 377ngg(-1) dw, 0.07 to 81.5ngg(-1) dw, and below the detection limit (DL) to 288ngg(-1) dw, respectively. Other organochlorinated pesticides (OCP) studied were 1-2 orders of magnitude lower. OCP and PCBs had higher concentrations at Burullus Lake, Abu Qir Bay, Alexandria Eastern Harbor, and El Max Bay compared to other sites. OCP and PCB contamination is higher in the vicinity of possible input sources such as shipping, industrial activities and urban areas. PCB congener profiles indicated they were derived from more than one commercially available mixture. The ratios of commercial chlordane and heptachlor metabolites indicate historical usage; however, DDT and HCHs inputs at several locations appear to be from recent usage. The concentrations of PCBs and DDTs are similar to those observed in sediments from coastal areas of the Mediterranean Sea. Ecotoxicological risk from DDTs and PCBs is greatest in Abu Qir Bay, Alexandria Harbor, and El-Max Bay. PMID:23880242

Barakat, Assem O; Mostafa, Alaa; Wade, Terry L; Sweet, Stephen T; El Sayed, Nadia B

2013-07-20

160

Species Distribution Models and Ecological Suitability Analysis for Potential Tick Vectors of Lyme Disease in Mexico  

Science.gov (United States)

Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.

Illoldi-Rangel, Patricia; Rivaldi, Chissa-Louise; Sissel, Blake; Trout Fryxell, Rebecca; Gordillo-Perez, Guadalupe; Rodriguez-Moreno, Angel; Williamson, Phillip; Montiel-Parra, Griselda; Sanchez-Cordero, Victor; Sarkar, Sahotra

2012-01-01

 
 
 
 
161

Distribution, Ecology and Conservation of the Common Otter (Lutra lutra) in DPRK (North Korea)  

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Full Text Available The Red Data Book of DPRK says that the otter belongs to the category of vulnerable species (VU) and suffers from a serious decrease in its numbers recently, although it was widely distributed in the middle and upper parts of rivers all over the country in the past. Therefore, the protection of the otter and its habitat is one of the important issues for species diversity conservation.

Chong Jong Ryol

2011-01-01

162

Ecology and distribution of Asellus aquaticus (1. ) in Norway, including relation to acidification in lakes  

Energy Technology Data Exchange (ETDEWEB)

Acellus aquaticus inhabits pristine oligotrophic and dystrophic lakes, as well as eutrophic sites influenced by agriculture or organic pollution. Total hardness in lakes with A. aquaticus was 0.23 -20.80 degrees dh (1 degrees dh = 10 mg ''CaO''/1) and pH 4.8 -8.8. Slow immigration and cold climate (above 1050 m altitude) restrict the distribution of the species. Acidification has occurred in lakes containing A. Aquaticus. It threatens existing populations and restricts the number of potentially new habitats for future immigration.

Okland, K.A.

1980-01-01

163

[Distribution and ecological characteristics of freshwater snails of medical importance in Santiago de Cuba province].  

UK PubMed Central (United Kingdom)

INTRODUCTION: The ability of freshwater snails to serve as intermediary host of parasites responsible for some tropical diseases is well known. OBJECTIVE: A malacological study was carried out in the Santiago de Cuba province in order to determine the distribution of freshwater snails of medical importance and their relation with the main ecosystems. METHOD: Nineteen sites were sampled in the province and the abundance of each of the species was compared to the type of habitat by means of the correspondence analysis. Each site was referred from the geographical viewpoint to determine the distribution patterns. RESULTS: A total amount of 12 freshwater snail species was found and the most abundant were Tarebia granifera, Physa acuta and Pyrgophorus parvulus. Rivers are the main types of ecosystems associated to these species followed by springs and ditches. Fossaria cubensis showed high density in flooded grounds whereas Biomphalaria pallida was the only planorbid species that could coexist with thiarid species. CONCLUSIONS: Due to the species found in this province, the likelihood of possible outbreaks of fasciolosis as well as the introduction of schistosomiasis is considered as high.

Vázquez Perera AA; González Coello C; Sánchez Noda J; Alba Menéndez A

2011-01-01

164

Introduction to Distribution and Ecology of Sterile Conks of Inonotus obliquus.  

UK PubMed Central (United Kingdom)

Inonotus obliquus is a fungus that causes white heart rot on several broad-leaved species. This fungus forms typical charcoal-black, sterile conks (chaga) or cinder conks on infected stems of the birche (Betula spp). The dark brown pulp of the sterile conk is formed by a pure mycelial mass of fungus. Chaga are a folk remedy in Russia, reflecting the circumboreal distribution of I. obliquus in boreal forest ecosystems on Betula spp. and in meridional mountain forests on beech (Fagus spp.) in Russia, Scandinavia, Central Europe, and Eastern Europe. Distribution at lower latitudes in Western and Southern Europe, Northern America, Asia, Japan, and Korea is rare. Infected trees grow for many years without several symptoms of decline. The infection can penetrate through stem injuries with exterior sterile conks developing later. In the Czech Republic, cinder conk is found on birches inhabiting peat bogs and in mountain areas with a colder and more humid climate, although it is widespread in other broad leaved species over the Czech Republic. The most common hosts are B. pendula, B. pubescens, B. carpatica, and F. sylvatica. Less frequent hosts include Acer campestre, Acer pseudoplatanus, Alnus glutinosa, Alnus incana, Fraxinus excelsior, Quercus cerris, Q. petraea, Q. robur, Q. delachampii, and Ulmus sp.

Lee MW; Hur H; Chang KC; Lee TS; Ka KH; Jankovsky L

2008-12-01

165

Introduction to Distribution and Ecology of Sterile Conks of Inonotus obliquus.  

Science.gov (United States)

Inonotus obliquus is a fungus that causes white heart rot on several broad-leaved species. This fungus forms typical charcoal-black, sterile conks (chaga) or cinder conks on infected stems of the birche (Betula spp). The dark brown pulp of the sterile conk is formed by a pure mycelial mass of fungus. Chaga are a folk remedy in Russia, reflecting the circumboreal distribution of I. obliquus in boreal forest ecosystems on Betula spp. and in meridional mountain forests on beech (Fagus spp.) in Russia, Scandinavia, Central Europe, and Eastern Europe. Distribution at lower latitudes in Western and Southern Europe, Northern America, Asia, Japan, and Korea is rare. Infected trees grow for many years without several symptoms of decline. The infection can penetrate through stem injuries with exterior sterile conks developing later. In the Czech Republic, cinder conk is found on birches inhabiting peat bogs and in mountain areas with a colder and more humid climate, although it is widespread in other broad leaved species over the Czech Republic. The most common hosts are B. pendula, B. pubescens, B. carpatica, and F. sylvatica. Less frequent hosts include Acer campestre, Acer pseudoplatanus, Alnus glutinosa, Alnus incana, Fraxinus excelsior, Quercus cerris, Q. petraea, Q. robur, Q. delachampii, and Ulmus sp. PMID:23997626

Lee, Min-Woong; Hur, Hyeon; Chang, Kwang-Choon; Lee, Tae-Soo; Ka, Kang-Hyeon; Jankovsky, L

2008-12-31

166

Species composition, distribution, and ecological preferences of the ticks of grazing sheep in north-central Spain.  

UK PubMed Central (United Kingdom)

The distribution and ecological preferences of tick (Acari: Ixodidae) parasites of grazing sheep in the region of Aragón (north-central Spain) were surveyed on flocks four times a year and mapped into a 5 x 5 km grid. Nine tick species were found. These were species of the Rhipicephalus sanguineus group (about 95% of them Rhipicephalus turanicus Pomerantsev, in 91% of cells of the grid), Rhipicephalus bursa Canestrini & Fanzago (79% of cells), Dermacentor marginatus (Sulzer) (58% of cells), Haemaphysalis punctata Canestrini & Fanzago (74% of cells) and Ixodes ricinus (Linnaeus) 14% of cells. Other species weakly represented in the surveys were Dermacentor reticulatus (Fabricius), Haemaphysalis sulcata Canestrini & Fanzago and Hyalomma m. marginatum Koch. Data on temperature, Normalized Difference Vegetation index (NDVI), topography, vegetation categories and plant productivity were used to build models of distribution and abundance of D. marginatus, H. punctata, R. bursa and R. turanicus. The occurrence models largely incorporated climatic variables and had good discrimination ability (P < 0.0001 for every modelled species, correct classification rate or sensitivity within 0.89 and 0.99), whereas the abundance models had a lower explanatory power. These models are relevant in the understanding of the variables composing the main distribution patterns, but they are unable adequately to predict the density. Abundance models produce good predictions in cells with low tick density, whereas poor correlation is observed in sites with high tick abundance. Several causes may be responsible for this low predictive power of the abundance models. Model output might be sensible to host density, to local farming practices, or to the size of the grid used to refer the results of the survey. In the latter case, small patches may support locally important populations of ticks, influencing largely the results of the survey. These patches of particular abiotic conditions, or supporting large host densities, may have been undetected at the resolution of the survey, thus obscuring the impact of the predictive variables.

Estrada-Peña A; Quíez J; Sánchez Acedo C

2004-06-01

167

Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, asexual fungus-growing ant.  

Science.gov (United States)

Sex and recombination are central processes in life generating genetic diversity. Organisms that rely on asexual propagation risk extinction due to the loss of genetic diversity and the inability to adapt to changing environmental conditions. The fungus-growing ant species Mycocepurus smithii was thought to be obligately asexual because only parthenogenetic populations have been collected from widely separated geographic localities. Nonetheless, M. smithii is ecologically successful, with the most extensive distribution and the highest population densities of any fungus-growing ant. Here we report that M. smithii actually consists of a mosaic of asexual and sexual populations that are nonrandomly distributed geographically. The sexual populations cluster along the Rio Amazonas and the Rio Negro and appear to be the source of independently evolved and widely distributed asexual lineages, or clones. Either apomixis or automixis with central fusion and low recombination rates is inferred to be the cytogenetic mechanism underlying parthenogenesis in M. smithii. Males appear to be entirely absent from asexual populations, but their existence in sexual populations is indicated by the presence of sperm in the reproductive tracts of queens. A phylogenetic analysis of the genus suggests that M. smithii is monophyletic, rendering a hybrid origin of asexuality unlikely. Instead, a mitochondrial phylogeny of sexual and asexual populations suggests multiple independent origins of asexual reproduction, and a divergence-dating analysis indicates that M. smithii evolved 0.5-1.65 million years ago. Understanding the evolutionary origin and maintenance of asexual reproduction in this species contributes to a general understanding of the adaptive significance of sex. PMID:21768368

Rabeling, Christian; Gonzales, Omar; Schultz, Ted R; Bacci, Maurício; Garcia, Marcos V B; Verhaagh, Manfred; Ishak, Heather D; Mueller, Ulrich G

2011-07-18

168

Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, asexual fungus-growing ant.  

UK PubMed Central (United Kingdom)

Sex and recombination are central processes in life generating genetic diversity. Organisms that rely on asexual propagation risk extinction due to the loss of genetic diversity and the inability to adapt to changing environmental conditions. The fungus-growing ant species Mycocepurus smithii was thought to be obligately asexual because only parthenogenetic populations have been collected from widely separated geographic localities. Nonetheless, M. smithii is ecologically successful, with the most extensive distribution and the highest population densities of any fungus-growing ant. Here we report that M. smithii actually consists of a mosaic of asexual and sexual populations that are nonrandomly distributed geographically. The sexual populations cluster along the Rio Amazonas and the Rio Negro and appear to be the source of independently evolved and widely distributed asexual lineages, or clones. Either apomixis or automixis with central fusion and low recombination rates is inferred to be the cytogenetic mechanism underlying parthenogenesis in M. smithii. Males appear to be entirely absent from asexual populations, but their existence in sexual populations is indicated by the presence of sperm in the reproductive tracts of queens. A phylogenetic analysis of the genus suggests that M. smithii is monophyletic, rendering a hybrid origin of asexuality unlikely. Instead, a mitochondrial phylogeny of sexual and asexual populations suggests multiple independent origins of asexual reproduction, and a divergence-dating analysis indicates that M. smithii evolved 0.5-1.65 million years ago. Understanding the evolutionary origin and maintenance of asexual reproduction in this species contributes to a general understanding of the adaptive significance of sex.

Rabeling C; Gonzales O; Schultz TR; Bacci M Jr; Garcia MV; Verhaagh M; Ishak HD; Mueller UG

2011-07-01

169

Towards a genome based taxonomy of Mycoplasmas.  

UK PubMed Central (United Kingdom)

Mycoplasmas are Gram-positive wall-less bacteria with a wide environmental and host distribution, causing disease in man and in (wild and farmed) animals. The aim of this study was to analyze the usefulness of a genomic taxonomic approach in Mycoplasma systematics. Multilocus Sequence Analysis (MLSA), average amino acid identity (AAI), and Karlin genomic signature allowed a clear identification of species. For instance, Mycoplasma pneumoniae and Mycoplasma genitalium had only 71% MLSA similarity, 67% AAI, and 88 for Karlin genomic signature. Codon usage (Nc) of the phylogenetically distantly related species Mycoplasma conjunctivae and Mycoplasma gallisepticum was identical, in spite of clear differences in MLSA, AAI, and Karlin, suggesting that these two species were subjected to convergent adaptation due to similar environmental conditions. We suggest that a Mycoplasma species may be better defined based on genomic features. In our hands, a Mycoplasma species is defined as a group of strains that share ? 97% DNA identity in MLSA, ? 93.9% AAI and ? 8 in Karlin genomic signature. This new definition may be useful to advance the taxonomy of Mycoplasmas.

Thompson CC; Vieira NM; Vicente AC; Thompson FL

2011-10-01

170

Fine-scale distribution patterns of Synechococcus ecological diversity in the microbial mats of Mushroom Spring, Yellowstone National Park  

DEFF Research Database (Denmark)

Past analyses of sequence diversity in high-resolution protein-encoding genes have identified putative ecological species of unicellular cyanobacteria in the genus Synechococcus, which are specialized to 60°C but not 65°C in Mushroom Spring microbial mats. Because these studies were limited to only two habitats, we studied the distribution of Synechococcus sequence variants at 1°C intervals along the effluent flow channel and at 80-µm vertical-depth intervals throughout the upper photic layer of the microbial mat. Diversity at the psaA locus, which encodes a photosynthetic reaction center protein (PsaA), was sampled by PCR amplification, cloning, and sequencing methods at 60, 63, and 65°C sites. The evolutionary simulation programs Ecotype Simulation and AdaptML were used to identify putative ecologically distinct populations (ecotypes). Ecotype Simulation predicted a higher number of putative ecotypes in cases where habitat variation was limited, while AdaptML predicted a higher number of ecologically distinct phylogenetic clades in cases where habitat variation was high. Denaturing gradient gel electrophoresis was used to track the distribution of dominant sequence variants of ecotype populations relative to temperature variation and to O2, pH, and spectral irradiance variation, as measured using microsensors. Different distributions along effluent channel flow and vertical gradients, where temperature, light, and O2 concentrations are known to vary, confirmed the ecological distinctness of putative ecotypes.

Becraft, E.; Cohan, F.

2011-01-01

171

Ecological suitability and spatial distribution of five Anopheles species in Amazonian Brazil.  

UK PubMed Central (United Kingdom)

Seventy-six sites characterized in Amazonian Brazil revealed distinct habitat diversification by examining the environmental factors associated with the distribution and abundance of five anopheline species (Diptera: Culicidae) in the subgenus Nyssorhynchus. These included three members of the Albitarsis Complex, Anopheles oryzalimnetes, Anopheles marajoara, Anopheles janconnae; Anopheles triannulatus, and Anopheles goeldii. Anopheles janconnae abundance had a positive correlation to water flow and a negative relationship to sun exposure. Abundance of An. oryzalimentes was associated with water chemistry. Anopheles goeldii larvae were abundant in shaded, more saline waters. Anopheles marajoara and An. triannulatus were negatively associated with available resources, although An. marajoara also showed several local correlations. These analyses suggest An. triannulatus is a habitat generalist, An. oryzalimentes and An. janconnae are specialists, and An. marajoara and An. goeldii could not be easily classified either way. Correlations described herein provide testable hypotheses for future research and identifying habitats for vector control.

McKeon SN; Schlichting CD; Povoa MM; Conn JE

2013-06-01

172

Ecological niche modeling and geographic distribution of the genus Polianthes L. (Agavaceae) in Mexico: using niche modeling to improve assessments of risk status  

UK PubMed Central (United Kingdom)

The genus Polianthes (Agavaceae) is endemic to Mexico and is important at the scientific, economical, and cultural level since prehispanic times. Habitat destruction is one of the main factors affecting populations of Polianthes species, yet little is known about the geographic distribution of this genus, and thus its vulnerability to habitat change. We compared three different approaches to measure the Polianthes species area of distribution to assess the risk of species extinction applying the MER (Method of Evaluation of Risk extinction of wild species for Mexico): area of occupancy, extent of occurrence, and ecological modeling. We also found the richness areas of distribution of this genus. We compared the species distributions with Terrestrial Protected Regions (TPR) and Natural Protected Areas (NPA). Although the three methods used to calculate the species area of distribution agree about the highly restricted nature of Polianthes species. The area of occupancy sub-estimate the species distribution, while the extent of occurrence over-estimate it for species with disjoint distribution. Thus, we recommend the use of ecological modeling to improve the assessment of the current species distribution area to apply the MER. Most Polianthes species are distributed in the Sierra Madre Occidental and Transvolcanic Belt. Three species do not occur in any of the NPA or TPR, one species has suitable habitat in three TPR but has not been recorded there, and one species, P. palustris, is likely extinct.

Solano Eloy; Feria TPatricia

2007-06-01

173

DIVERSITY RESOURCES, DISTRIBUTION AND PRESENT ECOLOGICAL STATUS OF HERMINIUM R. Br. A LESS KNOWN TERRESTRIAL ORCHID SPECIES OF DARJEELING HIMALAYA OF INDIA  

Directory of Open Access Journals (Sweden)

Full Text Available The present paper deals botanical description with five Herminium viz., Herminium jaffreyanum, H. lanceum, H. mackinnonii, H. macrophyllum and H. quinquelobum terrestrial Orchid species diversity resources and distribution in Darjeeling Himalaya of India. This attempt is the first step to correct taxonomic identification to workout currently accepted botanical names with ecological status, voucher specimen numbers, habitat, altitudinal ranges, phenology and local and general distribution of Herminium species in the regions. For the assessment of present ecological status, plot of 5mx5m quadrates was laid down diagonally in the field for terrestrial orchid species. Of them, three are sparse and the rest two are rare status in the region. June to October is the main flowering seasons of these species. It is found that the diversity and distribution frequency of Herminium species is rich and widespread throughout the Darjeeling Himalaya.

Rajendra Yonzone1* D. Lama1, R. B. Bhujel2, Khyanjeet Gogoi3 and Samuel Rai4

2012-01-01

174

Taxonomy and origin of reindeer  

Directory of Open Access Journals (Sweden)

Full Text Available Reindeer and caribou was probably the key species for the human immigration and colonization in the Arctic and sub-Arctic by the retreat of the ice in the last glacial period. The close connection between human and reindeer has contributed to great interest and variation in reindeer taxonomy and origin. Through the history several both species, subspecies and types of reindeer and caribou have been described. The early taxonomy of the species is marked by comparisons of individual specimen using traits as body size, skin colour or antler formations - characteristics known to be highly variable and subjected to environmental and nutritional level. During the mid 1900s the taxonomy was more based on variation of morphological traits among populations by analysing a large series of specimens representative of the various geographic populations and a consensus of classification of several subspecies, all belonging to the same species, evolved. During late 1900 the development of modern molecular techniques procured tools for revealing genetic structure of populations reflecting different origin and isolation rather than environmental influences. The genetic structure revealed a major genetic dichotomy between American woodland caribou on the one hand and all other types of reindeer and caribou on the other which gave evidence that the ancestors of present woodland caribou had survived and evolved in ice free refugium south to the glacier in North America and the ancestors of all other types of reindeer and caribou had evolved separated from these in refugium in Eurasia and Beringia. The ancestors of present reindeer in Scandinavia appear furthermore to have evolved from different populations separated during the last glaciation period and the colonization and origin of present wild and domestic reindeer will be discussed in this perspective.Taksonomi og opprinnelse til reinAbstract in Norwegian / Sammendrag: Rein og caribou har hatt stor betydning for det moderne menneskets utvikling og kolonisering av nordlige Eurasia og Amerika etter siste istid. Den nære sammenhengen mellom mennesker og rein har bidratt til stor interesse og variasjon i oppfatningen av reinens taksonomi og opprinnelse. Et utall av både arter, underarter og raser av rein er beskrevet opp gjennom historien. Tidlig taksonomi av rein bar preg av å være basert på enkeltobservasjoner og på morfologiske karakterer som kroppsstørrelse, pelsfarge og størrelse og form på gevir, karakterer som i stor grad påvirkes av miljø og næringsforhold. Først på midten av 1900 tallet ble taksonomien i større grad basert på ulike morfologiske trekk som viste variasjon mellom bestander av rein, og en fikk bl.a. en forståelse av at alle underarter og former av rein og caribou tilhørte samme art. Med utviklingen av den moderne molekylærbiologien på slutten av 1900-tallet fikk en tilgang til verktøy som avdekket genetiske strukturer som reflekterer ulik opprinnelse og utvikling mer enn miljømessig påvirkning. Den genetiske strukturen som ble avdekket, viste liten overensstemmelse med oppdelingen i underarter som var basert på morfologiske trekk. Molekylærgenetiske struktur viser et hovedskille mellom amerikansk woodland caribou på den ene siden og all annen rein og caribou på den andre siden, noe som reflekterer at forfedrene til woodland caribou levde og utviklet seg i isfrie områder sør for iskanten i Nord-Amerika, mens forfedrene til andre typer rein levde atskilt fra disse i isfrie områder i Eurasia og Beringia. Forfedrene til dagens rein i Fennoskandia syntes også å ha utviklet seg fra atskilte bestander av rein som kan føres tilbake til slutten av siste istid. Innvandring og opprinnelse til dagens vill- og tamrein i Fennoskandia vil bli belyst i dette perspektiv.

Knut H. Røed

2007-01-01

175

Notas adicionais sobre a taxonomia e a distribuição geográfica dos gêneros Alchorneopsis Muell. Arg., Cleidion Blume e Polyandra Leal (Euphorbiaceae- Acalyphoideae) Additional notes on taxonomy and geographic distribution of the genera Alchorneopsis Muell. Arg., Cleidion Blume and Polyandra Leal (Euphorbiaceae - Acalyphoideae)  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho apresenta dados taxonômicos e de distribuição geográfica sobre os gêneros Alchorneopsis, Cleidion e Polyandra. Alchorneopsis é um gênero monotípico da América Central, Colômbia, Guianas, Peru e Brasil. Cleidion, com a maioria de suas espécies distribuídas na região paleotropical, apresenta apenas três espécies na América Tropical. Polyandra, um gênero monotípico, é provavelmente endêmico da Amazônia brasileira. As relações taxonômicas dos gêneros estudados são discutidas e as espécies amazônicas ilustradas e comentadas.Complementary data are presented and discussed with regard to the taxonomy and geographic distribution of the genera Alchorneopsis, Cleidion and Polyandra. Alchorneopsis is a probably monotypic genus from Central América, Colômbia, Guiana, Peru and Brazil. Cleidion, with the majority of their 25 species in the paleotropics, has only three species in Tropical America. Polyandra, a monotypic genus, is probably endemic from Brazilian Amazonia. The taxonomic relations of the genera and species are discussed and the Amazonian species are illustrated.

Ricardo de S. Secco

2001-01-01

176

Marine ecology  

International Nuclear Information System (INIS)

[en] Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

1977-01-01

177

Ecological distribution of homobaric and heterobaric leaves in tree species of Malaysian lowland tropical rainforest.  

Science.gov (United States)

Tree species can generally be classified into two groups, heterobaric and homobaric leafed species, according to whether bundle-sheath extensions (BSEs) are found in the leaf (heterobaric leaf) or not (homobaric leaf). In this study, we study whether the leaf type is related to the growth environment and/or life form type, even in a tropical rain forest, where most trees have evergreen leaves that are generally homobaric. Accordingly, we investigated the distribution of leaf morphological differences across different life forms of 250 tree species in 45 families in a tropical rainforest. In total, 151 species (60%) in 36 families had homobaric leaves, and 99 species (40%) in 21 families had heterobaric leaves. We found that the proportion of heterobaric and homobaric leaf species differed clearly across taxonomic groups and life form types, which were divided into five life form types by their mature tree heights (understory, subcanopy, canopy, and emergent species) and as canopy gap species. Most understory (94%) and subcanopy (83%) species such as Annonaceae had homobaric leaves. In contrast, heterobaric leaf trees appeared more frequently in the canopy species (43%), the emergent species (96%) (such as Dipterocarpaceae), and the canopy gap species (62%). Our results suggest that tree species in the tropical rainforest adapt to spatial differences in the environmental conditions experienced at the mature height of each tree species, such as light intensity and vapor pressure difference, by having differing leaf types (heterobaric or homobaric) because these types potentially have different physiological and/or mechanical functions. PMID:21636445

Kenzo, Tanaka; Ichie, Tomoaki; Watanabe, Yoko; Hiromi, Toru

2007-05-01

178

Distribution, ecology and molecular identification of Thioploca from Danish brackish water sediments.  

UK PubMed Central (United Kingdom)

The distribution of Thioploca populations was investigated in Danish fjords, brackish lakes and coastal waters. Thioploca was found in three geographically distinct populations, where biomasses reached 33.8+/-14.3 g wet weight m(-2) (mean+/-SD). Mats or lawns were not formed at the sediment surfaces and Thioploca biomasses peaked 4-7 cm into the sediment and extended down to 18 cm depth. Morphology and 16S rRNA gene sequences classified all populations as Thioploca ingrica. A sequence divergence of 1.7-2.2% indicated that T. ingrica comprise at least two genotypes. Physiological analysis showed that T. ingrica accumulate nitrate in concentrations of approximately 3 mM and that bicarbonate and acetate are used as a carbon source. The presence of oxygen promoted carbon incorporation, but T. ingrica could survive up to 3 months without an external supply of nitrate or oxygen. Thioploca ingrica populations were exclusively found close to river outlets in a bioturbated sediment with separate sulphidic spots and worm burrow walls containing nitrate and oxygen. It is hypothesized that the subsurface T. ingrica have a special advantage in this heterogeneous environment using their sheath surrounding the bacterial trichomes when navigating between electron donor and acceptor.

Høgslund S; Nielsen JL; Nielsen LP

2010-07-01

179

Analysis of floral ecological and geographical distribution of Scorzonera genus in the Mongolian plateau  

UK PubMed Central (United Kingdom)

The Mongolian plateau lies in the Asia temperate zone and 11 species of Scorzonera genus which appeared at Mongolian plateau belong to 6 floral component. Existing of Europ-Asia temperate Zone element (1 sp.) consist with its geographical position of the Mongolian plateau which is situated in the temperate zone. The invasion of the Siberia element (1 sp.) at the northern part of Mongolian plateau and infiltration of east-Asia element (2 sp.) at the east-south of Mongolian plateau have reflected the connection of the floral of Scorzonera genus in the Mongolian plateau and the floral of Siberia and forest floral of East-Asia. Appearance of Loess-plateau element (1 sp.) shows the close relationship between the floral of Mongolian plateau and the floral of Loess plateau. The central-Asia element (5 sp.) plays main part in the Mongolian plateau, of which, S. grubvoii and S. capito are the unique. Appearance of these species results from evolution and suitability for long-term in the Mongolian plateau. Many species of Scorzonera genus belong to xerophyte, which mostly distributed in mountain and sand area. It has close relationship of floral northern China, north-east China and East-Siberia, respectively.

Liu Guixiang; Zhao Yizhi; Liu Lihua

2002-01-01

180

Distribution and ecology of non-marine ostracods (Crustacea, Ostracoda) from Friuli Venezia Giulia (NE Italy)  

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Full Text Available From August 1981 to July 2007, 200 inland water bodies were sampled to gather information on the Recent ostracod fauna of Friuli Venezia Giulia (NE Italy). A total of 320 samples were collected from surface, interstitial and ground waters. Whenever possible, ostracod identification was performed at species level based on the morphology of both valves and limbs. Seventy-four taxa in 30 genera belonging to 9 different families (Darwinulidae, Candonidae, Ilyocyprididae, Notodromadidae, Cyprididae, Limnocytheridae, Cytheridae, Leptocytheridae and Xestoleberididae) were identified. The maximum number of taxa per site was seven. The most common species was Cypria ophthalmica (133 records), followed by Cyclocypris ovum (86 records), C. laevis (49 records), Cypridopsis vidua (40 records) and Notodromas persica (28 records). Of particular relevance is the occurrence of six species new to Italy: Microdarwinula zimmeri, Penthesilenula brasiliensis, Fabaeformiscandona wegelini, Pseudocandona semicognita, Candonopsis scourfieldi, and C. mediosetosa. Scanning electron microscopy images of valves are provided for most of the described taxa. Geographical distribution of ostracods and their occurrence in relation to environmental variables were examined. The results of this study indicate that Friuli Venezia Giulia hosts a very diverse ostracod fauna, representing a significant proportion of all ostracod taxa known thus far from Italy.

Valentina PIERI; Koen MARTENS; Fabio STOCH; Giampaolo ROSSETTI

2009-01-01

 
 
 
 
181

Integrating evolution into geographical ecology: a phylogenetic perspective on palm distributions and community composition across scales  

DEFF Research Database (Denmark)

Species distributions, assemblage composition, and species richness depend on both current environment and the diversification of lineages in past environments. On broad scales, processes that constrain diversifying lineages to certain regions or environments are particularly important. Through species pool effects, those processes also affect local community composition and richness. In addition, evolution directly affects local communities directly via niche-based assembly. We studied these effects with palms (Arecaceae) as a model group, using a) a dataset including >340,000 palm individuals in 430 transects in the Western Amazon, b) a set of range maps for all American palms (550 spp.), and c) global country-level presence/ absence data of all (>2400) palm species. These data were analysed with novel phylogenetic community structure and turnover methods. Globally, the phylogenetic structure of palm assemblages reflects several biogeographic and evolutionary processes. In the Americas, both dispersal limitation and a phylogenetically conserved temperature niche have constrained the evolution of palm species ranges. Broad-scale processes also influenced the local phylogenetic structure of Amazonian palm communities, which mainly reflects the evolution of habitat preferences.

Eiserhardt, Wolf L.; Svenning, J.-C.

182

Distribution and ecology of Clostridium botulinum in fish and aquatic environments of a tropical region.  

UK PubMed Central (United Kingdom)

The distribution of Clostridium botulinum in sediments and fish from coastal and inland areas of India was investigated. Seventy-one samples of sediments from brackish water/freshwater farms on the west coast and from the seashores of both west and east coasts were analyzed. The overall prevalence of C. botulinum in sediments was 21% and the predominant types were types C and D (18%) followed by type A (3%). Sixty-eight samples of wild and farmed shellfish samples from the west coast were examined. Fifteen samples (22%) harboured C. botulinum and the identified C. botulinum types included type C (9%) and type A (4%). Sixty-one samples representing cultivable fish from the west coast and east coast (20), trash fish from the west coast (30) and farmed fish from the west coast (11) were screened and C. botulinum was detected in four (20%), eight (27%) and two (18%) samples, respectively. An overall prevalence of 22% was found in fish. The identified C. botulinum types on the surfaces of wild fish included type D (8%), type C (6%) and type A (6%) and type B(2%), whereas the intestine samples harboured types A (4%) and C (2%). In farmed fish, C. botulinum type C was detected in the intestine sample. The present study revealed that C. botulinum types C and D are the predominant types seen in fish and aquatic environments of the tropical Indian subcontinent.

Lalitha KV; Gopakumar K

2000-10-01

183

Distribution, diversity and ecology of modern freshwater ostracodes (Crustacea), and hydrochemical characteristics of Lago Petén Itzá, Guatemala  

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Full Text Available We analyzed modern ostracode species assemblages and water column physico-chemical characteristics in Lago Péten Itzá, Guatemala. Lake waters are dominated by sulfate, bicarbonate, calcium and magnesium and display a total ion concentration of ~11 meq L-1. Eleven extant ostracode species were identified. We found higher abundances of living ostracodes, as well as relatively higher species richness (eight species) and biodiversity (H of 1.6) between the littoral zone and a water depth of 20 m. At water depths >40 m, these variables all decreased. The thermocline is located at a water depth of ~20-40 m. Cluster analysis revealed three water depth ranges in the lake of importance to ostracode distribution: 1) littoral zone (0.1-3 m), 2) water depths from the base of the littoral zone to the base of the thermocline (3-40 m), and 3) water depths below the thermocline (40-160 m). The assemblage "Darwinula-Heterocypris-Pseudocandona-Strandesia" is characteristic of waters 40 m. Ostracode taxa from Lago Petén Itzá show specific ecological preferences related to water depth and associated physico-chemical characteristics, thus illustrating the potential of ostracodes as indicators of lake level changes and hydrodynamics.

Liseth PÉREZ; Julia LORENSCHAT; Rita BUGJA; Mark BRENNER; Burkhard SCHARF; Antje SCHWALB

2010-01-01

184

Ecological Research ????  

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Ecological Research has been published in English by the Ecological Society of Japan since 1986. The journal publishes original research papers, reviews, technical reports, and notes and comments covering all aspects of ecology and ecological sciences. ????????????????????????????

185

[Ecology and ecologies].  

UK PubMed Central (United Kingdom)

Ecology (from the Greek words ?????, "house" and ????? "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

Valera L

2011-01-01

186

ECOLOGIA Y DISTRIBUCION DE HYDROCOTYLE CRYPTOCARPA SPEG. EN SUDAMERICA ECOLOGY AND DISTRIBUTION OF HYDROCOTYLE CRYPTOCARPA SPEG. IN SOUTH AMERICA  

Directory of Open Access Journals (Sweden)

Full Text Available Hydrocotyle cryptocarpa ha sido descubierto recientemente en diferentes localidades de Chile. Se expone brevemente el actual conocimiento sobre su distribución geográfica, ciclo de vida y autoecología. H. cryptocarpa posee inflorescencias unifloras y frutos monospermos y geocarpos, dichas características la ubican en una posición aislada dentro del género Hydrocotyle. Esta especie es anual y crece en ambientes acuáticos temporales. Adaptaciones especiales a este tipo de habitat son una forma de vida tenagófita (germinación bajo el agua, floración y fructificación durante la ecofase terrestre) y representativa de un "amphibious fluctuation responder" (hojas largamente pecioladas durante la ecofase acuática, hojas de pecíolos breves en la ecofase terrestre). Su distribución es disyunta, con poblaciones halladas en Chile central (desde la Región de Coquimbo a la de La Araucanía) y otras halladas en torno al límite entre Uruguay y Argentina.Hydrocotyle cryptocarpa has recently been discovered from different localities in Chile. Our current knowledge about its total distribution, life cycle and ecology are summarized. H. cryptocarpa is monanthous, monospermous and geocarpous. With these characters, it has an isolated position within the genus Hydrocotyle. The species is annual and occurs in seasonal wetlands. Special adaptations to this habitat are the life cycle as a tenagophyte (germination under water, flowering and fruiting after desiccation of the pool) and as an amphibious fluctuation responder (long-stalked leaves in the aquatic ecophase, short-stalked leaves in the terrestrial ecophase). The distribution is highly disjunct, with populations recorded from central Chile (Region of Coquimbo to de La Araucanía), Uruguay and eastern Argentina.

Miguel Alvarez; Carlos Ramírez; Ulrich Deil

2008-01-01

187

Semisupervised Learning Taxonomy-Aware Catalog Integration  

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Full Text Available Data integration is the major important task for online commercial portals and commerce search engine based applications. The data integration task faced by online commercial portals and e-commerce search engines are the integration of products coming from multiple providers to their product catalogs. Categorization of products from the data provides into the master taxonomy and whereas make use of the data provider taxonomy information becomes major problem. Overcome this problem we classify the products based on their textual based classifier and taxonomy-aware step that adjusts the results of a textual based classifier to ensure that products that are close together in the provider taxonomy remain close in the master taxonomy. In taxonomy aware calibration step the base classifier derives the parameters value by tuning the values. Existing base classifier step, still it becomes major problem identify candidate products for labeling the products, to overcome these problem we proposed a Semi supervised learning techniques to incrementally retrain the base classifier with elements chosen during the taxonomy-aware calibration step. Proposed system it categorizes the product based on their parameters choosen from calibration. Semi supervised learning algorithm involves a large amount of unlabeled product data with only a small number of labeled product data. Semisupervised based active learning method identifies the candidate products for labeling. Proposed system finds the each candidate parameter ?? and then find the optimal parameter ? such that the improve the accuracy on the validation set is maximized. An experimental result shows that the Semi supervised learning algorithm that are efficient and thus applicable to the large data sets that are typical on the web.

D.Umavathi M.Sc1 , R.Tamil selvi M.Sc., M.Phil

2013-01-01

188

Classical taxonomy of mosquitoes--a memorial to John N. Belkin.  

UK PubMed Central (United Kingdom)

The major contributions of John N. Belkin to the field of mosquito systematics are noted. Hallmarks of his publications are presented and his hypotheses about the evolution, speciation, competition, distribution and classification of mosquitoes are summarized. The current status of the field of mosquito systematics is examined. It is argued that mosquito systematics is still largely at the alpha taxonomy level, that at best only 25-50% of mosquito species are known, and that we have not even begun to develop a natural classification for the Culicidae. It is concluded that there will be little improvement in the status of mosquito taxonomy unless there is increased support for systematics.

Zavortink TJ

1990-12-01

189

Infant mortality in South Africa - distribution, associations and policy implications, 2007: an ecological spatial analysis  

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Full Text Available Abstract Background Many sub-Saharan countries are confronted with persistently high levels of infant mortality because of the impact of a range of biological and social determinants. In particular, infant mortality has increased in sub-Saharan Africa in recent decades due to the HIV/AIDS epidemic. The geographic distribution of health problems and their relationship to potential risk factors can be invaluable for cost effective intervention planning. The objective of this paper is to determine and map the spatial nature of infant mortality in South Africa at a sub district level in order to inform policy intervention. In particular, the paper identifies and maps high risk clusters of infant mortality, as well as examines the impact of a range of determinants on infant mortality. A Bayesian approach is used to quantify the spatial risk of infant mortality, as well as significant associations (given spatial correlation between neighbouring areas) between infant mortality and a range of determinants. The most attributable determinants in each sub-district are calculated based on a combination of prevalence and model risk factor coefficient estimates. This integrated small area approach can be adapted and applied in other high burden settings to assist intervention planning and targeting. Results Infant mortality remains high in South Africa with seemingly little reduction since previous estimates in the early 2000's. Results showed marked geographical differences in infant mortality risk between provinces as well as within provinces as well as significantly higher risk in specific sub-districts and provinces. A number of determinants were found to have a significant adverse influence on infant mortality at the sub-district level. Following multivariable adjustment increasing maternal mortality, antenatal HIV prevalence, previous sibling mortality and male infant gender remained significantly associated with increased infant mortality risk. Of these antenatal HIV sero-prevalence, previous sibling mortality and maternal mortality were found to be the most attributable respectively. Conclusions This study demonstrates the usefulness of advanced spatial analysis to both quantify excess infant mortality risk at the lowest administrative unit, as well as the use of Bayesian modelling to quantify determinant significance given spatial correlation. The "novel" integration of determinant prevalence at the sub-district and coefficient estimates to estimate attributable fractions further elucidates the "high impact" factors in particular areas and has considerable potential to be applied in other locations. The usefulness of the paper, therefore, not only suggests where to intervene geographically, but also what specific interventions policy makers should prioritize in order to reduce the infant mortality burden in specific administration areas.

Sartorius Benn KD; Sartorius Kurt; Chirwa Tobias F; Fonn Sharon

2011-01-01

190

Taxonomy of bacterial fish pathogens  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens.

Austin Brian

2011-01-01

191

Blastocystis: Taxonomy, biology and virulence.  

Science.gov (United States)

The unicellular protist Blastocystis has long been an unsolved puzzle for taxonomists, microbiologists and clinicians. Over the years, the organism has been bounced on and off the different branches of the tree of life due the possession of unique phenotypic characters intermediary to different organisms. The organism is polymorphic with only few of forms such as vacuolar, granular, amoeboid, and the cyst form being commonly known. However it could exist in other forms much more frequently than the widely known forms which could be missed by the unaware observer. Certain older concepts in the life cycle of Blastocystis although has been proven wrong are still being followed in various textbooks and other trustworthy internet sources. The causal role of Blastocystis in human disease has long been a subject of controversy. It is widely believed that certain subtypes of the organism are virulent. But this is not so as other factors are also involved in the clinical outcome of the infection. In these contexts, this review intends to shed light on the past misconceptions and the recent findings on the taxonomy, biology and the virulence of this organism. PMID:23961437

Parija, Subhash Chandra; Jeremiah, Ss

2013-01-01

192

Blastocystis: Taxonomy, biology and virulence.  

UK PubMed Central (United Kingdom)

The unicellular protist Blastocystis has long been an unsolved puzzle for taxonomists, microbiologists and clinicians. Over the years, the organism has been bounced on and off the different branches of the tree of life due the possession of unique phenotypic characters intermediary to different organisms. The organism is polymorphic with only few of forms such as vacuolar, granular, amoeboid, and the cyst form being commonly known. However it could exist in other forms much more frequently than the widely known forms which could be missed by the unaware observer. Certain older concepts in the life cycle of Blastocystis although has been proven wrong are still being followed in various textbooks and other trustworthy internet sources. The causal role of Blastocystis in human disease has long been a subject of controversy. It is widely believed that certain subtypes of the organism are virulent. But this is not so as other factors are also involved in the clinical outcome of the infection. In these contexts, this review intends to shed light on the past misconceptions and the recent findings on the taxonomy, biology and the virulence of this organism.

Parija SC; Jeremiah S

2013-01-01

193

Allium olivieri Boiss. (Alliaceae), a new taxon to Turkey, with contributions to its taxonomy  

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Full Text Available Allium olivieri Boiss. (Alliaceae) is reported as a new record for Turkish flora. It was identified using the collected specimens and Flora orientalis, Flora of Iraq and Flora Iranica. The detailed description, illustrations, geographical distribution, habitat, status of IUCN extinction risk and some comments and discussions on the taxonomy of the species are given.

?smail Eker; Mehmet Koyuncu

2011-01-01

194

Ecological studies in the Bay of Paranaguá: I. horizontal distribution and seasonal dynamics of the phytoplankton  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Foram feitas coletas mensais na Baia de Paranaguá (Paraná) em 5 estações fixas durante um ano (1983-1984) para se medir parâmetros ambientais básicos, biomassa e fotossíntese do fitoplâncton durante um período sazonal. A temperatura na superfície variou de 17 a 30ºC. As médias anuais de salinidade, oxigênio dissolvido e pH variaram de 9,38-32,00?, 5,17-5,53 ml/l e 7,468,18, respectivamente. As concentrações médias do nitrogênio inorgânico total, fosfato (more) e silicato variaram de 3,31-8,48, 0,38-0,97 e 27,68-98,36 µg-at/l, respectivamente, com os máximos obtidos na parte mais interna da baia. A clorofila-a na superfície variou entre 2,86 e 13,99 mg/m³ com máximos na parte mais interna da baía associadas às altas concentrações de nutrientes e salinidades mais baixas. As taxas de fotossíntese obtidas na superfície variaram entre 0,01 e 7,36 mgC/m³/h, com máximos na região mais interna da baía. Fitoflagelados e Skeletonema costatum dominaram a populaçao fitoplanctonica durante o período estudado. As variações temporais no interior da baía foram associadas ao regime de chuvas. A alta pluviosidade aumenta a concentração de nutrientes e conseqüentemente, estimula o desenvolvimento do fitoplâncton que é, no entanto, limitado pela deficiência em nitrogênio e pela turbidez da água. Abstract in english Five stations were sampled monthly in the Bay of Paranaguá during one year cycle (1983-1984) to measure basic environmental parameters, phytoplankton biomass and photosynthesis with the purpose of understanding the principal factors that regulate the phytoplankton growth and distribution throughout the year. Surface temperature varied from 17 to 30ºC. The yearly average values for salinity, dissolved oxygen and pH ranged from 9.38 to 32.00?, 5.17 to 5.53 ml/l and 7.46 (more) to 8.18, respectively. Average concentrations of total inorganic nitrogen, phosphate and silicate varied from 3.31 to 8.48, 0.38 to 0.97 and 27.68 to 98.36 µg-at/l, respectively, with increasing concentrations toward the inner bay. Chlorophyll-a at the surface varied between 2.86 and 13.99 mg/m³ with high concentrations in the inner bay associated with high nutrient contents and lower salinities. Low photosynthetic rates were measured at the surface, varying from 0.01 to 7.36 mgC/m³/h. Phytoflagellates and Skeletonema costatum dominated the phytoplankton population during the study period. The temporal fluctuations in the inner bay are associated with the rainfall regime. High amounts of precipitation increase the concentrations of nutrients and consequently improve the phytoplankton growth. This is however limited by nitrogen deficiency (as indicated by the low N to P ratios observed) and turbidity.

Brandini, Frederico P

1985-01-01

195

Ecological studies in the bay of Paranaguá: I. horizontal distribution and seasonal dynamics of the phytoplankton  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Foram feitas coletas mensais na Baia de Paranaguá (Paraná) em 5 estações fixas durante um ano (1983-1984) para se medir parâmetros ambientais básicos, biomassa e fotossíntese do fitoplâncton durante um período sazonal. A temperatura na superfície variou de 17 a 30ºC. As médias anuais de salinidade, oxigênio dissolvido e pH variaram de 9,38-32,00?, 5,17-5,53 ml/l e 7,468,18, respectivamente. As concentrações médias do nitrogênio inorgânico total, fosfato (more) e silicato variaram de 3,31-8,48, 0,38-0,97 e 27,68-98,36 µg-at/l, respectivamente, com os máximos obtidos na parte mais interna da baia. A clorofila-a na superfície variou entre 2,86 e 13,99 mg/m³ com máximos na parte mais interna da baía associadas às altas concentrações de nutrientes e salinidades mais baixas. As taxas de fotossíntese obtidas na superfície variaram entre 0,01 e 7,36 mgC/m³/h, com máximos na região mais interna da baía. Fitoflagelados e Skeletonema costatum dominaram a populaçao fitoplanctonica durante o período estudado. As variações temporais no interior da baía foram associadas ao regime de chuvas. A alta pluviosidade aumenta a concentração de nutrientes e conseqüentemente, estimula o desenvolvimento do fitoplâncton que é, no entanto, limitado pela deficiência em nitrogênio e pela turbidez da água. Abstract in english Five stations were sampled monthly in the Bay of Paranaguá during one year cycle (1983-1984) to measure basic environmental parameters, phytoplankton biomass and photosynthesis with the purpose of understanding the principal factors that regulate the phytoplankton growth and distribution throughout the year. Surface temperature varied from 17 to 30ºC. The yearly average values for salinity, dissolved oxygen and pH ranged from 9.38 to 32.00?, 5.17 to 5.53 ml/l and 7.46 (more) to 8.18, respectively. Average concentrations of total inorganic nitrogen, phosphate and silicate varied from 3.31 to 8.48, 0.38 to 0.97 and 27.68 to 98.36 µg-at/l, respectively, with increasing concentrations toward the inner bay. Chlorophyll-a at the surface varied between 2.86 and 13.99 mg/m³ with high concentrations in the inner bay associated with high nutrient contents and lower salinities. Low photosynthetic rates were measured at the surface, varying from 0.01 to 7.36 mgC/m³/h. Phytoflagellates and Skeletonema costatum dominated the phytoplankton population during the study period. The temporal fluctuations in the inner bay are associated with the rainfall regime. High amounts of precipitation increase the concentrations of nutrients and consequently improve the phytoplankton growth. This is however limited by nitrogen deficiency (as indicated by the low N to P ratios observed) and turbidity.

Brandini, Frederico P

1985-01-01

196

[Ecological distribution and antimicrobial effects of soil actinomycetes in artificial vegetation systems in Shazhuyu of Qinghai, China].  

UK PubMed Central (United Kingdom)

In order to probe into the effects of artificial vegetation rehabilitation on soil actinomycetes, dilution plate and agar block methods were used to investigate the ecological distribution and antimicrobial effects of actinomycetes in sandy soil in Shazhuyu area of Qinghai after artificial vegetation restoration. The results showed that with the vegetation rehabilitation and the improvement of vegetation coverage on alpine sandy dry land, the quantity of soil actinomycetes increased significantly, being 145.4% higher in the grassland transferred from farmland than in sandy land. The quantity of soil Micromonospora in grassland transferred from farmland was about six times as much as that in sandy land. The average selection rate of antimicrobial actinomycetes was increased greatly, with the antimicrobial actinomycetes in the soil of grassland transferred from farmland, the antibacterial actinomycetes in the soil of natural grassland, and the pathogenic fungus resistant aetinomycetes in the soil of forestland being approximately 2, 3.2 and 1.5 times as much as those in the soil of sandy land, respectively. Vegetation coverage and soil nutrients had great influences on the quantities of actinomycetes and antimicrobial actinomycetes. The contents of soil organic matter and alkali-hydrolyzable nitrogen and the yield of fresh grasses had significant correlations with the quantities of actinomycetes (P < 0.01), and the content of soil organic matter and the yield of fresh grasses significantly correlated with the strain numbers of antimicrobial actinomycetes (P < 0.01). Furthermore, vegetation coverage and the contents of soil total nitrogen, total phosphorous, total potassium, total salt, and available potassium had significant correlations with the total quantities of actinomycetes, Streptomycetes, and Micromonospora (P < 0.05).

Yang B; Xue QH; Chen ZQ; Guo ZY; Zhang XL; Zhou YQ; Xu YJ; Sun DF

2008-08-01

197

Distribution Pattern and Dynamics of Dominant Population in the Progression of Ecological Restoration of Evergreen Broadleaved Forest after Wind-damage in Jinyun Mountain  

UK PubMed Central (United Kingdom)

We investigated the species,quantity and growth state of the plants at the wind?dama??ged? slash in 1992,1994,1996,1999 and 2001.On the basis of the investigation into ecological restoration of evergreen broadleaved forest of wind?damaged slash in Jinyun Mountain,we studied the distribution pattern and dynamics of dominant population.The result indicates that seedlings of Pinus massoniana and Gordonia acuminata are decreasing,but the seedlings of Costanopsis carlesii var.spinulosa,Symplocos setchuanenesis and other evergreen broadleaved trees are increasing.Patterns of spatial dispersion of the dominant population are varied with size class,the clumped distribution appears in Costanopsis carlesii var.spinulosa and Symplocos setchuanenesis,Possion distribution in ? and ? class of Gordonia acuminata after 1996,before 1996,it appeared clumped distribution.? and ? class in Pinus massoniana and Gordonia acuminata are appearing possion distribution.The age?structure of Pinus massoniana and Gordonia acuminata appeared growing.

Shi Shengyou; Shang Jin; Tian Haiyan; Li Xuguang

2003-01-01

198

Using ecological niche modelling to predict spatial and temporal distribution patterns in Chinese gibbons: lessons from the present and the past.  

UK PubMed Central (United Kingdom)

Ecological niche modelling (ENM) is used to predict species' tolerance to changing environmental conditions. Understanding changes in the spatial distribution of species across time is essential in order to develop effective conservation strategies. Here we map the past and present distribution of gibbons across China, a country experiencing extensive anthropogenic habitat destruction and ongoing biodiversity loss. The distribution of gibbons across three time intervals is described based on fossil, historical and modern-day data, and ENM, implemented using DIVA-GIS, is used to predict how modern-day gibbon distributions might respond to future climate change. Predictions based on modern-day data alone fail to reveal patterns of environmental tolerance and geographical distribution shown by gibbons in the relatively recent historical period, emphasizing the need to incorporate past as well as present data in conservation analyses.

Chatterjee HJ; Tse JS; Turvey ST

2012-01-01

199

Using ecological niche modelling to predict spatial and temporal distribution patterns in Chinese gibbons: lessons from the present and the past.  

Science.gov (United States)

Ecological niche modelling (ENM) is used to predict species' tolerance to changing environmental conditions. Understanding changes in the spatial distribution of species across time is essential in order to develop effective conservation strategies. Here we map the past and present distribution of gibbons across China, a country experiencing extensive anthropogenic habitat destruction and ongoing biodiversity loss. The distribution of gibbons across three time intervals is described based on fossil, historical and modern-day data, and ENM, implemented using DIVA-GIS, is used to predict how modern-day gibbon distributions might respond to future climate change. Predictions based on modern-day data alone fail to reveal patterns of environmental tolerance and geographical distribution shown by gibbons in the relatively recent historical period, emphasizing the need to incorporate past as well as present data in conservation analyses. PMID:23038160

Chatterjee, H J; Tse, J S Y; Turvey, S T

2012-10-02

200

Fundamentals of ecology. Vol. 2. Grundlagen der Oekologie. Bd. 2. Standorte und Anwendung  

Energy Technology Data Exchange (ETDEWEB)

The following topics are discussed: freshwater flora and fauna; marine ecosystems; shelf, krill, mangroves, and coral reefs; terrestrial biota and biogeographic regions; deciduous wood, grassland, desert; microbial-ecological perspectives: taxonomy, efficiency, turnover; aquaculture, agriculture, forestry; types, cost, and phases of environmental pollution; specific population ecology of humans.

Odum, E.P.

1980-01-01

 
 
 
 
201

Refining a taxonomy for guideline implementation: results of an exercise in abstract classification.  

UK PubMed Central (United Kingdom)

BACKGROUND: To better understand the efficacy of various implementation strategies, improved methods for describing and classifying the nature of these strategies are urgently required. The aim of this study was to develop and pilot the feasibility of a taxonomy to classify the nature and content of implementation strategies. METHODS: A draft implementation taxonomy was developed based on the Cochrane Effective Practice and Organisation of Care (EPOC) data collection checklist. The draft taxonomy had four domains (professional, financial, organisational and regulatory) covering 49 distinct strategies. We piloted the draft taxonomy by using it to classify the implementation strategies described in the conference abstracts of the implementation stream of the 2010 Guideline International Network Conference. Five authors classified the strategies in each abstract individually. Final categorisation was then carried out in a face-to-face consensus meeting involving three authors. RESULTS: The implementation strategies described in 71 conference abstracts were classified. Approximately 15.5% of abstracts utilised strategies that could not be categorised using the draft taxonomy. Of those strategies that could be categorised, the majority were professionally focused (57%). A total of 41% of projects used only one implementation strategy, with 29% using two and 31% three or more. The three most commonly used strategies were changes in quality assurance, quality improvement and/or performance measurement systems, changes in information and communication technology, and distribution of guideline materials (via hard-copy, audio-visual and/or electronic means). CONCLUSIONS: Further refinement of the draft taxonomy is required to provide hierarchical dimensions and granularity, particularly in the areas of patient-focused interventions, those concerned with audit and feedback and quality improvement, and electronic forms of implementation, including electronic decision support.

Mazza D; Bairstow P; Buchan H; Chakraborty SP; Van Hecke O; Grech C; Kunnamo I

2013-01-01

202

Occurrence, distribution, and ecological risk assessment of DDTs and heavy metals in surface sediments from Lake Awassa-Ethiopian Rift Valley Lake.  

UK PubMed Central (United Kingdom)

Dichlorodiphenyltrichloroethanes (DDTs) and heavy metals are ubiquitous contaminants with high bioaccumulation and persistence in the environment, which can have adverse effects on humans and animals. Although applications of DDTs have been banned in many countries, developing countries like Ethiopia are still using these for agricultural and medicinal purposes. In addition, heavy metals are naturally present in the aquatic environment and distributed globally. In this study, the occurrence, distribution, and ecological risk of DDTs and heavy metals in surface sediments from one of the Ethiopian rift valley lakes were studied. Twenty-five surface sediment samples from Lake Awassa, Ethiopia were collected and analyzed for DDTs and heavy metals. Results showed that concentrations of total DDTs ranged from 3.64 to 40.2 ng/g dry weight. High levels of DDTs were observed in the vicinity of inflow river side and coastal areas with agricultural activities. The heavy metals content were followed the order Zn?>?Ni?>?Pb?>?Cu?>?Cr?>?Co?>?As?>?Cd?>?Hg. Correlation analysis and principal components analysis demonstrated that heavy metals were originated from both natural and anthropogenic inputs. The levels of DDE and DDD in surface sediments exceeded the sediment quality guideline values, indicating that adverse effects may occur to the lake. A method based on toxic-response factor for heavy metals revealed that the calculated potential ecological risk indices showed low ecological risk for the water body.

Yohannes YB; Ikenaka Y; Saengtienchai A; Watanabe KP; Nakayama SM; Ishizuka M

2013-05-01

203

THE EFFECT OF AGRO-ECOLOGICAL ZONES ON THE INCIDENCE AND DISTRIBUTION OF APHID VECTORS OF PEPPER VEINAL MOTTLE VIRUS, ON CULTIVATED PEPPER (CAPSICUM ANNUUM L.) IN NIGERIA  

Directory of Open Access Journals (Sweden)

Full Text Available The distribution of aphid vectors of Pepper veinal mottle virus (PVMV) was studied on cultivated pepper between 2003 and 2005 in the major pepper producing areas of the six agro-ecological zones in Nigeria. The aphids were isolated, identified and their transmission ability determined. Population of aphid vectors increased progressively in all the agro-ecological zones from March at the onset of raining season reaching a peak in August and then declining from September at the on set of the dry season. The Humid forest and Derived Savanna agro-ecological zones recorded highest mean population of aphids / leaf and types of aphid’s species compared with other agro-ecological zones. Six species of aphid, Myzus persicae (Sulzer), Aphis gossipii (Glover), Aphis craccivora (Koch), Aphis spiraecola (Patch), Aphis fabae (Blanchard), and Rhopalosiphum maidis (Fitch), were identified on the pepper fields surveyed in all the agro-ecological zones. There was no significant difference in the occurrence of M. persicae, A. gossipii, A. craccivora, and R. maidis while A. spiraecola and A. fabae that varied in occurrence in all the zones. Ability to transmit PVMV to a healthy pepper plants varied in all the identified aphid species but R. maidis was not able to transmit PVMV from infected to a healthy pepper plant. A more sustainable approach to controlling pepper viruses is by targeting the aphid vectors and preventing the vectors from reaching the crops because the aphid vectors which are virus specific are the major means of transmitting virus to healthy plant.

A.A. FAJINMI; C.A. ODEBODE; O.B. FAJINMI

2011-01-01

204

Ecological Applications ????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ecological Applications invites contributions from scientists, policy makers, and managers concerned with the full spectrum of ecological applications. Included within this spectrum are global climate change and biogeochemistry, conservation biology, ecotoxicology and pollution ecology, fishe...

205

Ecological Monographs ????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ecological Monographs, issued quarterly, publishes complex, multi-faceted studies that demand greater length than those published in Ecology or Ecological Applications. These are not merely long papers, but must tell a truly complicated scientific story with multiple components....

206

The colonial legacy in African plant taxonomy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The conservation of biodiversity is inescapably linked to taxonomy and systematics, the branches of science dealing with the identification, naming and classification of organisms. If there is no reliable and correct name (and therefore no associated description) for a given organism, that organism ...

Figueiredo, Estrela; Smith, G.F. (Gideon Francois), 1959-

207

Taxonomy of an endemic Aristolochia (Aristolochiaceae) from the Iberian Peninsula  

Directory of Open Access Journals (Sweden)

Full Text Available The taxonomy of an Iberian endemic Aristolochia is treated, based on morphological and cytological characters. A brief description of its main diagnostic characters, distribution and habitat is included, as well as a distribution map and a few comments on its possible phylogenetic relationships. A new combination is proposed, raising this taxon from subspecies to a species proper: A. castellana (Nardi) Costa. A revised dichotomous key for the Iberian taxa of the genus is proposed.El presente trabajo trata la taxonomía de una Aristolochia endémica de la Península Ibérica, basándose en caracteres morfológicos y citológicos. Se incluye una breve descripción de los caracteres diagnósticos principales, de su distribución y hábitat, así como un mapa de su distribución y algunos comentarios sobre sus posibles relaciones filogenéticas. Se propone una nueva combinación, ascendiendo el taxon de subespecie a especie: A. castellana (Nardi) Costa. Se propone una nueva clave dicotómica para los táxones del género presentes en la Península Ibérica.

Costa, Andrea

2008-01-01

208

Ecological distribution and fate of plutonium and americium in a processing waste pond on the Hanford Reservation  

International Nuclear Information System (INIS)

[en] During the past 21/2 yr a study was conducted on the Hanford Reservation concerning the ecological behavior of plutonium and americium in a radioactive waste pond which has been receiving low-level Pu processing waste for about 30 yr. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization and studies of the ecological behavior of Pu and Am in an ultra-eutrophic aquatic environment. The purpose of this work is to explain Pu and Am concentrations at specific ecological sites, rates of accumulation at these sites, important export routes out of the pond, and potential pathways to man. Seston (30 percent diatoms) appears to be the principal concentrator of transuranics in the pond system. Organic floc, overlaying the pond sediments that are the major sink for Pu and Am in this system, is also a major concentrator of transuranics. Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Thus, transuranics appear to be relatively immobile in this aquatic ecosystem

1976-01-01

209

An Extended and Granular Classification of Cloud’s Taxonomy and Services  

Directory of Open Access Journals (Sweden)

Full Text Available In the recent time cloud computing has come forwarded as one of the most admired computing model in knowledge domain that concerns about the distributed information systems to support the whole world as a cloud community. Distributed, virtualization and service-oriented nature have given ascendancy to cloud computing to distinguish from its core descendants like grid computing, geographical information systems, and distributed system. Although cloud computing dominants the e-society, but it is still in under research, progress. The architecture of cloud’s taxonomy and its services are very significant issues for cloudifications because every day some new advancements and developments are adjoined under its umbrella. In this paper we proposed an extended and granular classification of taxonomy for cloud computing and specified services that is a detailed ontology of cloud, which will be helpful for researchers and stakeholders in better understanding, developing, and implementing cloud technology and services to their lives.

Shah Murtaza Rashid Al Masud

2012-01-01

210

Modeling ecological niches and predicting geographic distributions: a test of six presence-only methods/ Modelado de nichos ecológicos y predicción de distribuciones geográficas: comparación de seis métodos  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La predicción de las distribuciones geográficas de las especies obtenida mediante el modelado de sus nichos ecológicos, representa una línea de investigación en expansión, la cual ha sido aplicada en múltiples áreas de conocimiento tales como ecología, sistemática y salud pública. La creciente disponibilidad y variedad de tales métodos y algoritmos de predicción determina su evaluación como necesaria. En este estudio, comparamos 6 algoritmos (Maxent, BioMapp (more) er, Domain, FloraMap, GARP, Weights of Evidence) con respecto a su habilidad para predecir las distribuciones geográficas de 10 especies de aves de México, para las cuales se cuenta con suficientes datos distribucionales. No obstante, los resultados de nuestro estudio sugieren la necesidad de elaborar nuevos criterios para la evaluación de modelos. Abstract in english Modeling ecological niches of species as a means to predict geographic distributions is a growing field that has been applied to numerous challenges of importance in ecology, systematics, and human well-being. The increasing availability and variety of such predictive algorithms requires testing their performance. In this study, we compare 6 such algorithms (Maxent, BioMapper, DOMAIN, FloraMap, the genetic algorithm GARP, and weights of evidence) as regards their ability (more) to predict the geographic distributions of 10 species of Mexican birds for which ample distributional data are available. The results of this study nevertheless led to reflections on how model quality should be evaluated.

Ortega-Huerta, Miguel A.; Townsend Peterson, A

2008-06-01

211

Modeling ecological niches and predicting geographic distributions: a test of six presence-only methods Modelado de nichos ecológicos y predicción de distribuciones geográficas: comparación de seis métodos  

Directory of Open Access Journals (Sweden)

Full Text Available Modeling ecological niches of species as a means to predict geographic distributions is a growing field that has been applied to numerous challenges of importance in ecology, systematics, and human well-being. The increasing availability and variety of such predictive algorithms requires testing their performance. In this study, we compare 6 such algorithms (Maxent, BioMapper, DOMAIN, FloraMap, the genetic algorithm GARP, and weights of evidence) as regards their ability to predict the geographic distributions of 10 species of Mexican birds for which ample distributional data are available. The results of this study nevertheless led to reflections on how model quality should be evaluated.La predicción de las distribuciones geográficas de las especies obtenida mediante el modelado de sus nichos ecológicos, representa una línea de investigación en expansión, la cual ha sido aplicada en múltiples áreas de conocimiento tales como ecología, sistemática y salud pública. La creciente disponibilidad y variedad de tales métodos y algoritmos de predicción determina su evaluación como necesaria. En este estudio, comparamos 6 algoritmos (Maxent, BioMapper, Domain, FloraMap, GARP, Weights of Evidence) con respecto a su habilidad para predecir las distribuciones geográficas de 10 especies de aves de México, para las cuales se cuenta con suficientes datos distribucionales. No obstante, los resultados de nuestro estudio sugieren la necesidad de elaborar nuevos criterios para la evaluación de modelos.

Miguel A. Ortega-Huerta; A Townsend Peterson

2008-01-01

212

Distribution of trace elements in certain ecological components and animal products in a dairy farm at Tirupati, Chittoor District, Andhra Pradesh, India.  

UK PubMed Central (United Kingdom)

Biogeochemical characteristics of the cattle are dealt based on the observations made in Ayurveda in the light of modern scientific developments in applied environmental geochemistry. The biogeochemical characteristics of certain important ecological components and animal products of the stall-fed animals were studied. For this purpose, a dairy farm of Tirumala-Tirupati Devasthanams, a religious organization in Tirupati, Chittoor District, Andhra Pradesh was selected. This study is intended to trace out the trace element interactions in the ecological components (soil, water, fodder, feed) of the stall-fed animals and their output components viz. dung, urine and milk. Physical, physico-chemical properties and certain trace elements were determined for composite samples of ecological components and dung, urine, and milk of stall-fed animals. The variations in the distribution of pH and EC of urine and milk reflect the variations in their physico-chemical or hydro-chemical properties. As mentioned in Ayurveda, not only the properties of milk but also the properties of dung and urine reflect their diet and conditions of their habitat. Even though the diet is the same, the cows of different breeds yield milk of variable physical, physico-chemical properties and trace element composition which can be attributed to their body colour, substantiating Ayurveda.

Raghu V

2013-07-01

213

Hierarchical and Bayesian Scattered Data Taxonomy in Mobile Ad-hoc Network  

Directory of Open Access Journals (Sweden)

Full Text Available MANETS promise an unprecedented opportunity to monitor physical environments via inexpensive wireless embedded devices. Given the sheer amount of sensed data, efficient taxonomy of them becomes a critical task in many sensor network applications. The Bayesian classifier is a fundamental taxonomy technique. We introduce two classifiers: Naive Bayes and a classifier based on class decomposition using K-means clustering. We consider two complementary tasks: model computation and scoring a data set. We study several layouts for tables and several indexing alternatives.In this paper, we propose a novel decision-tree-based hierarchical scattered taxonomy approach, in which local classifiers are built by individual sensors and merged along the routing path forming a spanning tree. The classifiers are iteratively enhanced by combining strategically generated pseudo data and new local data, eventually converging to a global classifier for the whole network. We also introduce some control factors to facilitate the effectiveness of our approach. Through extensive analysis, we study the impact of the introduced control factors, and demonstrate that our approach maintains high taxonomy accuracy with very low storage and communication overhead. The approach also addresses a critical issue of heterogeneous data distribution among the sensors.

Sunar Arif Hussain; K.E.Sreenivasa Murthy

2011-01-01

214

Integrative taxonomy on the fast track - towards more sustainability in biodiversity research.  

UK PubMed Central (United Kingdom)

BACKGROUND: A so called "taxonomic impediment" has been recognized as a major obstacle to biodiversity research for the past two decades. Numerous remedies were then proposed. However, neither significant progress in terms of formal species descriptions, nor a minimum standard for descriptions have been achieved so far. Here, we analyze the problems of traditional taxonomy which often produces keys and descriptions of limited practical value. We suggest that phylogenetics and phenetics had a subtle and so far unnoticed effect on taxonomy leading to inflated species descriptions. DISCUSSION: The term "turbo-taxonomy" was recently coined for an approach combining cox1 sequences, concise morphological descriptions by an expert taxonomist, and high-resolution digital imaging to streamline the formal description of larger numbers of new species. We propose a further development of this approach which, together with open access web-publication and automated pushing of content from journal into a wiki, may create the most efficient and sustainable way to conduct taxonomy in the future. On demand, highly concise descriptions can be gradually updated or modified in the fully versioned wiki-framework we use. This means that the visibility of additional data is not compromised, while the original species description -the first version- remains preserved in the wiki, and of course in the journal version. A DNA sequence database with an identification engine replaces an identification key, helps to avoid synonyms and has the potential to detect grossly incorrect generic placements. We demonstrate the functionality of a species-description pipeline by naming 101 new species of hyperdiverse New Guinea Trigonopterus weevils in the open-access journal ZooKeys. SUMMARY: Fast track taxonomy will not only increase speed, but also sustainability of global species inventories. It will be of great practical value to all the other disciplines that depend on a usable taxonomy and will change our perception of global biodiversity. While this approach is certainly not suitable for all taxa alike, it is the tool that will help to tackle many hyperdiverse groups and pave the road for more sustainable comparative studies, e.g. in community ecology, phylogeography and large scale biogeographic studies.

Riedel A; Sagata K; Suhardjono YR; Tänzler R; Balke M

2013-01-01

215

Taxonomic, phylogenetic, and ecological diversity of methanogenic Archaea  

Energy Technology Data Exchange (ETDEWEB)

Methanogens are strict anaerobes which share a complex biochemistry for methane synthesis as part of their energy metabolism. The discovery of the unique biochemical and genetic properties of these organisms led to the concept of Archaebacteria at the end of the seventies and the proposal in 1990 for the domain Archaea. A number of studies have provided evidence that they are of economic value. The successive petroleum crisis since 1973 has led to great interest in alternative forms of energy, including recovery of methane via anaerobic digestion of wastes. Improvements in the design of digestors have been made possible by advances in understanding the ecology and physiology of methanogens. In the cattle industry, the knowledge of the fermentation processes in the rumen demonstrated a net loss of energy via the methanogenesis, and inhibitors such as Rumensin have been developed to enhance meat yields. Oil companies try to distinguish between natural gas produced by methanogens or by the thermocatalytic reactions associated with petroleum generation. Finally, studies on the global distribution of methane in the earth's atmosphere are increasing due to the sudden awareness of its possible role in the enhancement of the greenhouse effect from CO-2 accumulation, and on the reversal of stratospheric ozone depletion. This paper summarizes the recent knowledge of methanogenic Archaea with emphasis on their taxonomy and ecology. (author)

Garcia, J.-L.; Ollivier, B. [Universite de Provence, Marseille (France). Laboratoire de Microbiologist; Patel, B.K.C. [Griffith University, Brisbane (Australia). Microbial Discovery Research Unit

2000-07-01

216

[Distribution and ecological risk assessment of polycyclic aromatic hydrocarbons in agricultural soil of the Chongming Island in Shanghai].  

UK PubMed Central (United Kingdom)

The concentration and ecological risk of Polycyclic aromatic hydrocarbons (PAHs) were investigated in thirty-three surface soil samples collected from cultivated land in Chongming Island in July 2008. Those samples were extracted using an accelerated solvent extractor (ASE) and determined by GC-MS. Results showed that the concentrations of PAHs ranged between 24.92-1014.61 ng x g(-1) (dry weight), with a mean value of 192.83 ng x g(-1). The sixteen priority PAHs with exception of Indeno(1, 2, 3-cd) pyrene (IcdP) and Dibenzo(a, h)anthracene (DahA) were all detected in all the samples. The dominant compounds were 2-3 ring and 4 ring PAHs, which accounted for 42.6% and 42.2%, respectively, while the 5-6 ring PAHs accounted for 15.7%. PAHs in soil were mainly derived from the fossil oil and the combustion of wood and coal, as determined by the concentration ratio method. The non-industrial combustion and automobile exhaust emissions in Chongming Island may be two of the important sources of PAHs in farmland soil. The analysis of ecological risk showed that the agricultural soil of Chongming Island had low ecological risk.

Lü JG; Bi CJ; Chen ZL; Zhou JC; Han JC

2012-12-01

217

Hierarchical Taxonomy in Multi-Party System  

CERN Multimedia

We propose the use of hierarchical taxonomy to analyze the legislative election results as a model of multi-party system to show the robustness in political system. As an example we use the result of Indonesian legislative election 2004 is analyzed with certain comparative with the previous one (1999). We construct the graph theoretical analysis by finding the Euclidean distances among political parties. The distances are then treated in ultrametric spaces by using the minimum spanning tree algorithm. By having the Indonesian hierarchical taxonomy model of political parties we show some patterns emerging the pattern agrees with the classical anthropological analysis of socio-political system in Indonesia. This fact accentuates a character of robustness in Indonesian political society as a self-organized system evolves to critical state. Some small perturbations i.e.: different voting process resulting the same pattern and occasions statistically, emerges from the social structure based upon political streams:...

Situngkir, H

2004-01-01

218

Multi-faceted Learning for Web Taxonomies  

UK PubMed Central (United Kingdom)

A standard problem for internet commerce is the task ofbuilding a product taxonomy from web pages, without access to corporatedatabases. However, a nasty aspect of the real world is that mostweb-pages have multiple facets. A web page might contain informationabout both cameras and computers, as well as having both specicationand sale data. We are interested in methods for supervised and unsupervisedlearning of multiple faceted models. Here we present results formulti-faceted clustering of bigram words data.

Wray Buntine; Henry Tirri

219

Multi-faceted Learning for Web Taxonomies  

UK PubMed Central (United Kingdom)

A standard problem for internet commerce is the task ofbuilding a product taxonomy from web pages, without access to corporatedatabases. However, a nasty aspect of the real world is that mostweb-pages have multiple facets. A web page might contain informationabout both cameras and computers, as well as having both specificationand sale data. We are interested in methods for supervised and unsupervisedlearning of multiple faceted models. Here we present results formulti-faceted clustering of bigram words data.

Wray Buntine; Henry Tirri

220

Distribution characteristics and potential ecological risk assessment of heavy metals (Cu, Pb, Zn, Cd) in water and sediments from Lake Dalinouer, China.  

UK PubMed Central (United Kingdom)

The concentrations of Cu, Pb, Zn and Cd were measured in water and sediment to determine their distribution characteristics and potential ecological risks of the Lake Dalinouer. The results revealed that the dominate form of Cu, Pb, Cd and Zn in surface sediments respectively were organic sulfides, Fe-Mn oxides, carbonates and Fe-Mn oxides, with a mean content of 4.28mgkg(-1), 0.76mgkg(-1), 7.84?gkg(-1) and 1.77mgkg(-1), respectively; the concentrations of bio-available metals had an increase tendency from the northeast to the southwest part of this lake. Acid volatile sulfides (AVS) and simultaneously extracted metal (SEM) were used to predict the potential bioavailability of heavy metals. The horizontal distribution of AVS (0.15-2.4?molg(-1), mean 0.53?molg(-1)) in surface sediments shows an increasing trend from southwest to northeast of the lake, whereas SEM (0.02-0.99?molg(-1), mean 0.37?molg(-1)) had an opposite pattern. The relative high salt and pH which restrained the bioactivities of sulfate-reducing bacteria (SRB) were the main controlling factor in AVS concentrations. The vertical variation of AVS concentration in sediment core increased with depth and different from SEM. Potential ecological risk index (PERI) and geo-accumulation index (Igeo) were used to assess heavy metals accumulation. The results indicated that moderate contamination of most heavy metals was prevalent and presented a decreased trend from southern to northern of the lake, and element Cd emerged the greatest potential ecological risk. The pollution of heavy metal in the southern of the Lake Dalinouer should be taken into consideration seriously.

Hou D; He J; Lü C; Ren L; Fan Q; Wang J; Xie Z

2013-07-01

 
 
 
 
221

Distribution characteristics and potential ecological risk assessment of heavy metals (Cu, Pb, Zn, Cd) in water and sediments from Lake Dalinouer, China.  

Science.gov (United States)

The concentrations of Cu, Pb, Zn and Cd were measured in water and sediment to determine their distribution characteristics and potential ecological risks of the Lake Dalinouer. The results revealed that the dominate form of Cu, Pb, Cd and Zn in surface sediments respectively were organic sulfides, Fe-Mn oxides, carbonates and Fe-Mn oxides, with a mean content of 4.28mgkg(-1), 0.76mgkg(-1), 7.84?gkg(-1) and 1.77mgkg(-1), respectively; the concentrations of bio-available metals had an increase tendency from the northeast to the southwest part of this lake. Acid volatile sulfides (AVS) and simultaneously extracted metal (SEM) were used to predict the potential bioavailability of heavy metals. The horizontal distribution of AVS (0.15-2.4?molg(-1), mean 0.53?molg(-1)) in surface sediments shows an increasing trend from southwest to northeast of the lake, whereas SEM (0.02-0.99?molg(-1), mean 0.37?molg(-1)) had an opposite pattern. The relative high salt and pH which restrained the bioactivities of sulfate-reducing bacteria (SRB) were the main controlling factor in AVS concentrations. The vertical variation of AVS concentration in sediment core increased with depth and different from SEM. Potential ecological risk index (PERI) and geo-accumulation index (Igeo) were used to assess heavy metals accumulation. The results indicated that moderate contamination of most heavy metals was prevalent and presented a decreased trend from southern to northern of the lake, and element Cd emerged the greatest potential ecological risk. The pollution of heavy metal in the southern of the Lake Dalinouer should be taken into consideration seriously. PMID:23602414

Hou, Dekun; He, Jiang; Lü, Changwei; Ren, Limin; Fan, Qingyun; Wang, Jinghua; Xie, Zhilei

2013-04-18

222

Evolutionary ecology in silico: evolving food webs, migrating population and speciation  

Science.gov (United States)

After a brief review of our recent works on “unified” models of evolutionary ecology, we have generalized our “unified” model by taking into account spatial variations from one “patch” to another. We model the spatial extension of the ecosystem (i.e., the geography) by a square lattice where each site corresponds to a distinct “patch”. A distinct self-organizing hierarchical food web describes the prey predator relations at each patch in the ecosystem. By carrying out computer simulations up to 10 time steps, we found that, depending on the values of the set of parameters, the distribution of the lifetimes of the species can be fitted to power laws, but only over a very restricted regime of lifetimes. We also interpret our model in terms of taxonomy and present results to elucidate some evolutionary trends in genus, family, order, class, phylum, etc.

Stauffer, Dietrich; Kunwar, Ambarish; Chowdhury, Debashish

2005-07-01

223

Taxonomia e distribuição do gênero Caulerpa Lamouroux (Bryopsidales - Chlorophyta) na costa de Pernambuco e Arquipélago de Fernando de Noronha, Brasil Taxonomy and distribution of the genus Caulerpa Lamouroux (Bryopsidales - Chlorophyta) on the coast of Pernambuco State and Fernando de Noronha Archipelago, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho identifica e fornece a distribuição do gênero Caulerpa na costa de Pernambuco (07º30' S e 09º00' W) e no Arquipélago de Fernando de Noronha (03º51' S e 32º25' W). As coletas foram realizadas em 32 praias da costa de Pernambuco no período entre abril/2004 a novembro/2005, na região entre-marés. Em Fernando de Noronha as coletas foram feitas em junho/2006, na região entre marés e no infralitoral (10, 15 e 21 m de profundidade), em oito praias. Foram, também, analisadas as exsicatas de Caulerpa depositadas no Herbário Professor Vasconcelos Sobrinho (PEUFR) da Universidade Federal Rural de Pernambuco. Os resultados mostram que o gênero Caulerpa está representado na costa de Pernambuco, por 19 táxons infragenéricos. Algumas espécies apresentaram distribuição restrita como C. kempfii Joly & Pereira, C. lanuginosa J. Agardh e C. serrulata (Forssk.) J. Agardh. Para o Arquipélago de Fernando de Noronha foram registrados três táxons infragenéricos.This paper analyzes the taxonomy and distribution of the genus Caulerpa on the coast of Pernambuco (07º30'S; 09º00'W) and in the Fernando de Noronha Archipelago (03º51'S; 32º25'W). Sampling was carried out on the coast of Pernambuco from April/2004 to November/2005, in the intertidal zone of 32 beaches. On Fernando de Noronha collections were made in June/2006 in the intertidal and infralittoral (10, 15 and 21m depth) regions of eight beaches. Exsiccata of Caulerpa from the Professor Vasconcelos Sobrinho Herbarium (PEUFR) were also examined. The results showed that the genus Caulerpa is represented on the coast of Pernambuco state by 19 infrageneric taxa. Some species had restricted distributions such as C. kempfii Joly & Pereira, C. lanuginosa J. Agardh and C. serrulata (Forssk.) J. Agardh. Three infrageneric taxa were registered for the Fernando de Noronha Archipelago.

Suellen Brayner; Sonia Maria Barreto Pereira; Maria Elizabeth Bandeira-Pedrosa

2008-01-01

224

Taxonomia e distribuição do gênero Caulerpa Lamouroux (Bryopsidales - Chlorophyta) na costa de Pernambuco e Arquipélago de Fernando de Noronha, Brasil/ Taxonomy and distribution of the genus Caulerpa Lamouroux (Bryopsidales - Chlorophyta) on the coast of Pernambuco State and Fernando de Noronha Archipelago, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este trabalho identifica e fornece a distribuição do gênero Caulerpa na costa de Pernambuco (07º30' S e 09º00' W) e no Arquipélago de Fernando de Noronha (03º51' S e 32º25' W). As coletas foram realizadas em 32 praias da costa de Pernambuco no período entre abril/2004 a novembro/2005, na região entre-marés. Em Fernando de Noronha as coletas foram feitas em junho/2006, na região entre marés e no infralitoral (10, 15 e 21 m de profundidade), em oito praias. For (more) am, também, analisadas as exsicatas de Caulerpa depositadas no Herbário Professor Vasconcelos Sobrinho (PEUFR) da Universidade Federal Rural de Pernambuco. Os resultados mostram que o gênero Caulerpa está representado na costa de Pernambuco, por 19 táxons infragenéricos. Algumas espécies apresentaram distribuição restrita como C. kempfii Joly & Pereira, C. lanuginosa J. Agardh e C. serrulata (Forssk.) J. Agardh. Para o Arquipélago de Fernando de Noronha foram registrados três táxons infragenéricos. Abstract in english This paper analyzes the taxonomy and distribution of the genus Caulerpa on the coast of Pernambuco (07º30'S; 09º00'W) and in the Fernando de Noronha Archipelago (03º51'S; 32º25'W). Sampling was carried out on the coast of Pernambuco from April/2004 to November/2005, in the intertidal zone of 32 beaches. On Fernando de Noronha collections were made in June/2006 in the intertidal and infralittoral (10, 15 and 21m depth) regions of eight beaches. Exsiccata of Caulerpa fr (more) om the Professor Vasconcelos Sobrinho Herbarium (PEUFR) were also examined. The results showed that the genus Caulerpa is represented on the coast of Pernambuco state by 19 infrageneric taxa. Some species had restricted distributions such as C. kempfii Joly & Pereira, C. lanuginosa J. Agardh and C. serrulata (Forssk.) J. Agardh. Three infrageneric taxa were registered for the Fernando de Noronha Archipelago.

Brayner, Suellen; Pereira, Sonia Maria Barreto; Bandeira-Pedrosa, Maria Elizabeth

2008-12-01

225

Distribution of rare earths, thorium and uranium in bryophytes and soils in Tripui Ecological Station, Minas Gerais, Brazil  

International Nuclear Information System (INIS)

The concentrations of rare earth elements (REEs), thorium and uranium were determined in liverworts (Noteroclada confluens (Tayl.) and Dumortirea hirsute (Sw.) Nees), in mosses (Leucobryum martianum (Hornsh.) Hampe, Vesicularia vesicularis (Schwaegr.) Broth., Pyrrhobruym spiniforme (Hedw.) Mitt. and Sematophyllum subsimplex (Hedw.) Mitt.) and in the soil upon which they were growing. The samples were collected on the margins of the main streams of the Tripui Ecological Station, located in the valley of the Tripui stream near the town of Ouro Preto, Minas Gerais State, Brazil. For decades, this Station has been the object of interest of many studies due to its historical, ecological and environmental importance. Analyses in bryophytes (mosses and liverworts) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and in the soil samples by using neutron activation analysis (NAA), specifically the k0-standardization method and the energy dispersive spectrometry technique (EDS). Lanthanum (La), cerium (Ce) and neodymium (Nd) were present in higher concentrations in soils and bryophytes than other REEs. It was observed that in all the collected bryophytes species the elements Th, U, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Yb were transferred from the soil water to these plants. These bryophytes presented different capacities of accumulating these elements with the liverworts (Noteroclada confluens and Dumortirea hirsute) and the moss Leucobryum martianum showing a more efficient accumulation capacity than the other bryophyte species. (author)

2007-10-05

226

Distribution of rare earths, thorium and uranium in bryophytes and soils in Tripui Ecological Station, Minas Gerais, Brazil  

Energy Technology Data Exchange (ETDEWEB)

The concentrations of rare earth elements (REEs), thorium and uranium were determined in liverworts (Noteroclada confluens (Tayl.) and Dumortirea hirsute (Sw.) Nees), in mosses (Leucobryum martianum (Hornsh.) Hampe, Vesicularia vesicularis (Schwaegr.) Broth., Pyrrhobruym spiniforme (Hedw.) Mitt. and Sematophyllum subsimplex (Hedw.) Mitt.) and in the soil upon which they were growing. The samples were collected on the margins of the main streams of the Tripui Ecological Station, located in the valley of the Tripui stream near the town of Ouro Preto, Minas Gerais State, Brazil. For decades, this Station has been the object of interest of many studies due to its historical, ecological and environmental importance. Analyses in bryophytes (mosses and liverworts) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and in the soil samples by using neutron activation analysis (NAA), specifically the k{sub 0}-standardization method and the energy dispersive spectrometry technique (EDS). Lanthanum (La), cerium (Ce) and neodymium (Nd) were present in higher concentrations in soils and bryophytes than other REEs. It was observed that in all the collected bryophytes species the elements Th, U, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Yb were transferred from the soil water to these plants. These bryophytes presented different capacities of accumulating these elements with the liverworts (Noteroclada confluens and Dumortirea hirsute) and the moss Leucobryum martianum showing a more efficient accumulation capacity than the other bryophyte species. (author)

Palmieri, Helena E.L. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], E-mail: help@cdtn.br; Nalini Junior, Herminio A. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil). Dept. de Geologia], E-mail: nalini@degeo.ufop.br; Friese, Kurt [Helmholtz Centre for Environmental Research- UFZ, Magdeburg (Germany). Dept. of Lake Research], E-mail: kurt.friese@ufz.de

2007-07-01

227

Predicting the distribution and ecological niche of unexploited snow crab (Chionoecetes opilio) populations in Alaskan waters: a first open-access ensemble model.  

UK PubMed Central (United Kingdom)

Populations of the snow crab (Chionoecetes opilio) are widely distributed on high-latitude continental shelves of the North Pacific and North Atlantic, and represent a valuable resource in both the United States and Canada. In US waters, snow crabs are found throughout the Arctic and sub-Arctic seas surrounding Alaska, north of the Aleutian Islands, yet commercial harvest currently focuses on the more southerly population in the Bering Sea. Population dynamics are well-monitored in exploited areas, but few data exist for populations further north where climate trends in the Arctic appear to be affecting species' distributions and community structure on multiple trophic levels. Moreover, increased shipping traffic, as well as fisheries and petroleum resource development, may add additional pressures in northern portions of the range as seasonal ice cover continues to decline. In the face of these pressures, we examined the ecological niche and population distribution of snow crabs in Alaskan waters using a GIS-based spatial modeling approach. We present the first quantitative open-access model predictions of snow-crab distribution, abundance, and biomass in the Chukchi and Beaufort Seas. Multi-variate analysis of environmental drivers of species' distribution and community structure commonly rely on multiple linear regression methods. The spatial modeling approach employed here improves upon linear regression methods in allowing for exploration of nonlinear relationships and interactions between variables. Three machine-learning algorithms were used to evaluate relationships between snow-crab distribution and environmental parameters, including TreeNet, Random Forests, and MARS. An ensemble model was then generated by combining output from these three models to generate consensus predictions for presence-absence, abundance, and biomass of snow crabs. Each algorithm identified a suite of variables most important in predicting snow-crab distribution, including nutrient and chlorophyll-a concentrations in overlying waters, temperature, salinity, and annual sea-ice cover; this information may be used to develop and test hypotheses regarding the ecology of this species. This is the first such quantitative model for snow crabs, and all GIS-data layers compiled for this project are freely available from the authors, upon request, for public use and improvement.

Hardy SM; Lindgren M; Konakanchi H; Huettmann F

2011-10-01

228

Modeling ecological minimum requirements for distribution of greater sage-grouse leks: implications for population connectivity across their western range, U.S.A.  

Science.gov (United States)

Greater sage-grouse Centrocercus urophasianus (Bonaparte) currently occupy approximately half of their historical distribution across western North America. Sage-grouse are a candidate for endangered species listing due to habitat and population fragmentation coupled with inadequate regulation to control development in critical areas. Conservation planning would benefit from accurate maps delineating required habitats and movement corridors. However, developing a species distribution model that incorporates the diversity of habitats used by sage-grouse across their widespread distribution has statistical and logistical challenges. We first identified the ecological minimums limiting sage-grouse, mapped similarity to the multivariate set of minimums, and delineated connectivity across a 920,000 km2 region. We partitioned a Mahalanobis D2 model of habitat use into k separate additive components each representing independent combinations of species–habitat relationships to identify the ecological minimums required by sage-grouse. We constructed the model from abiotic, land cover, and anthropogenic variables measured at leks (breeding) and surrounding areas within 5 km. We evaluated model partitions using a random subset of leks and historic locations and selected D2 (k = 10) for mapping a habitat similarity index (HSI). Finally, we delineated connectivity by converting the mapped HSI to a resistance surface. Sage-grouse required sagebrush-dominated landscapes containing minimal levels of human land use. Sage-grouse used relatively arid regions characterized by shallow slopes, even terrain, and low amounts of forest, grassland, and agriculture in the surrounding landscape. Most populations were interconnected although several outlying populations were isolated because of distance or lack of habitat corridors for exchange. Land management agencies currently are revising land-use plans and designating critical habitat to conserve sage-grouse and avoid endangered species listing. Our results identifying attributes important for delineating habitats or modeling connectivity will facilitate conservation and management of landscapes important for supporting current and future sage-grouse populations.

Knick, Steven T.; Hanser, Steven E.; Preston, Kristine L.

2013-01-01

229

Modeling ecological minimum requirements for distribution of greater sage-grouse leks: implications for population connectivity across their western range, U.S.A.  

Science.gov (United States)

Greater sage-grouse Centrocercus urophasianus (Bonaparte) currently occupy approximately half of their historical distribution across western North America. Sage-grouse are a candidate for endangered species listing due to habitat and population fragmentation coupled with inadequate regulation to control development in critical areas. Conservation planning would benefit from accurate maps delineating required habitats and movement corridors. However, developing a species distribution model that incorporates the diversity of habitats used by sage-grouse across their widespread distribution has statistical and logistical challenges. We first identified the ecological minimums limiting sage-grouse, mapped similarity to the multivariate set of minimums, and delineated connectivity across a 920,000 km(2) region. We partitioned a Mahalanobis D (2) model of habitat use into k separate additive components each representing independent combinations of species-habitat relationships to identify the ecological minimums required by sage-grouse. We constructed the model from abiotic, land cover, and anthropogenic variables measured at leks (breeding) and surrounding areas within 5 km. We evaluated model partitions using a random subset of leks and historic locations and selected D (2) (k = 10) for mapping a habitat similarity index (HSI). Finally, we delineated connectivity by converting the mapped HSI to a resistance surface. Sage-grouse required sagebrush-dominated landscapes containing minimal levels of human land use. Sage-grouse used relatively arid regions characterized by shallow slopes, even terrain, and low amounts of forest, grassland, and agriculture in the surrounding landscape. Most populations were interconnected although several outlying populations were isolated because of distance or lack of habitat corridors for exchange. Land management agencies currently are revising land-use plans and designating critical habitat to conserve sage-grouse and avoid endangered species listing. Our results identifying attributes important for delineating habitats or modeling connectivity will facilitate conservation and management of landscapes important for supporting current and future sage-grouse populations. PMID:23789066

Knick, Steven T; Hanser, Steven E; Preston, Kristine L

2013-04-22

230

Modeling ecological minimum requirements for distribution of greater sage-grouse leks: implications for population connectivity across their western range, U.S.A.  

UK PubMed Central (United Kingdom)

Greater sage-grouse Centrocercus urophasianus (Bonaparte) currently occupy approximately half of their historical distribution across western North America. Sage-grouse are a candidate for endangered species listing due to habitat and population fragmentation coupled with inadequate regulation to control development in critical areas. Conservation planning would benefit from accurate maps delineating required habitats and movement corridors. However, developing a species distribution model that incorporates the diversity of habitats used by sage-grouse across their widespread distribution has statistical and logistical challenges. We first identified the ecological minimums limiting sage-grouse, mapped similarity to the multivariate set of minimums, and delineated connectivity across a 920,000 km(2) region. We partitioned a Mahalanobis D (2) model of habitat use into k separate additive components each representing independent combinations of species-habitat relationships to identify the ecological minimums required by sage-grouse. We constructed the model from abiotic, land cover, and anthropogenic variables measured at leks (breeding) and surrounding areas within 5 km. We evaluated model partitions using a random subset of leks and historic locations and selected D (2) (k = 10) for mapping a habitat similarity index (HSI). Finally, we delineated connectivity by converting the mapped HSI to a resistance surface. Sage-grouse required sagebrush-dominated landscapes containing minimal levels of human land use. Sage-grouse used relatively arid regions characterized by shallow slopes, even terrain, and low amounts of forest, grassland, and agriculture in the surrounding landscape. Most populations were interconnected although several outlying populations were isolated because of distance or lack of habitat corridors for exchange. Land management agencies currently are revising land-use plans and designating critical habitat to conserve sage-grouse and avoid endangered species listing. Our results identifying attributes important for delineating habitats or modeling connectivity will facilitate conservation and management of landscapes important for supporting current and future sage-grouse populations.

Knick ST; Hanser SE; Preston KL

2013-06-01

231

Backyard Ecology.  

Science.gov (United States)

|Describes the Ecology Explorers, the community education component of Arizona State University's Central Arizona Phoenix Long-Term Ecological Research project, which offers teacher internship programs that link university researchers, K-12 teachers, and students in studying urban ecology. Explains that student neighborhoods are dynamic ecosystems…

Elser, Monica; Musheno, Birgit; Saltz, Charlene

2003-01-01

232

Ecology Letters ?????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ecology Letters is a forum for the very rapid publication of the most novel research in ecology. Manuscripts relating to the ecology of all taxa, in any biome and geographic area will be considered, and priority will be given to those papers exploring or testing clearly stated hypotheses. The...

233

Web Ecology ?????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Web Ecology is an electronic peer-reviewed journal issued by the European Ecological Federation in cooperation with the Oikos Editorial Office, Lund, Sweden. Ecologists from all countries are invited to publish original results on its pages. Web Ecology will publish studies and re...

234

Assessment of spatial distribution and potential ecological risk of the heavy metals in relation to granulometric contents of Veeranam lake sediments, India.  

UK PubMed Central (United Kingdom)

The contents and spatial distributions of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) have been studied in surface sediments of Veeranam lake, Tamilnadu, India. Heavy metal contents are higher in open water area (limnetic zone) (OWA) than other two regions such as inflow river mouth (littoral zone) (IFR) and outflow river mouth region (OFR). Present metal contents are compared with both background and toxicological reference values. The comparative results suggest that the present metals except Cd and Pb create an adverse effect on the aquatic ecosystems associated with this lake. The Pollution Load Index (PLI) and Potential Ecological Risk (PER) are calculated and calculated PLI values (range: 1.18-4.09 with an average of 2.03) show that the present sediments are polluted significantly and these values are higher in OWA region. From the PER values, each single element has low potential ecological risk. However, Cd shows higher ecological risk. The comprehensive PER index of the sediments shows moderate degree. The magnetic susceptibility is higher in OWA region. Granulometric analysis confirms that the silt is major content. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis) were carried out and obtained results suggested that the heavy metals in present lake have complicated contamination sources or controlling factors and the heavy metals such as Cr, Cu, Ni and Zn may be incorporated in magnetic minerals which are presented in silt grains. Also it shows that the role of silt is incorporating the cations on their surface and raising the level of magnetic susceptibility and heavy metal contents. The present study recommends that the heavy metal levels are unlikely to cause additional adverse health risks to the aquatic ecosystem associated with this lake.

Suresh G; Sutharsan P; Ramasamy V; Venkatachalapathy R

2012-10-01

235

Dissecting in silico: towards a taxonomy for medical simulators.  

UK PubMed Central (United Kingdom)

In this paper, we investigated several approaches in literature that classify different aspects of medical simulators. We have merged these definitions to form a structured taxonomy. This new taxonomy should facilitate the design of new medical simulators and allow to analyze and classify existing simulators, algorithms, toolkits and hardware.

Ullrich S; Knott T; Kuhlen T

2011-01-01

236

Dissecting in silico: towards a taxonomy for medical simulators.  

Science.gov (United States)

In this paper, we investigated several approaches in literature that classify different aspects of medical simulators. We have merged these definitions to form a structured taxonomy. This new taxonomy should facilitate the design of new medical simulators and allow to analyze and classify existing simulators, algorithms, toolkits and hardware. PMID:21335878

Ullrich, Sebastian; Knott, Thomas; Kuhlen, Torsten

2011-01-01

237

Taxonomy of the nuclear plant operator's role  

International Nuclear Information System (INIS)

A program is presently under way at the Oak Ridge National Laboratory (ORNL) to define the functional design requirements of operational aids for nuclear power plant operators. A first and important step in defining these requirements is to develop an understanding of the operator's role or function. This paper describes a taxonomy of operator functions that applies during all operational modes and conditions of the plant. Other topics such as the influence of automation, role acceptance, and the operator's role during emergencies are also discussed. This systematic approach has revealed several areas which have potential for improving the operator's ability to perform his role.

1981-06-19

238

Taxonomy of Penicillium section Citrina  

DEFF Research Database (Denmark)

Species of Penicillium section Citrina have a worldwide distribution and occur commonly in soils. The section is here delimited using a combination of phenotypic characters and sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA (ITS) and partial RPB2 sequences. Species assigned to section Citrina share the production of symmetrically biverticillate conidiophores, flask shaped phialides (7.0–9.0 ?m long) and relatively small conidia (2.0–3.0 ?m diam). Some species can produce greyish-brown coloured cleistothecia containing flanged ascospores. In the present study, more than 250 isolates presumably belonging to section Citrina were examined using a combined analysis of phenotypic and physiological characters, extrolite profiles and ITS, ?-tubulin and/or calmodulin sequences. Section Citrina includes 39 species, and 17 of those are described here as new. The most important phenotypic characters for distinguishing species are growth rates and colony reverse colours on the agar media CYA, MEA and YES; shape, size and ornamentation of conidia and the production of sclerotia or cleistothecia. Temperature-growth profiles were made for all examined species and are a valuable character characters for species identification. Species centered around P. citrinum generally have a higher maximum growth temperature (33–36 °C) than species related to P. westlingii (27–33 °C). Extrolite patterns and partial calmodulin and ?-tubulin sequences can be used for sequence based identification and resolved all species. In contrast, ITS sequences were less variable and only 55 % of the species could be unambiguously identified with this locus.

Houbraken, Jos; Frisvad, Jens Christian

2011-01-01

239

Morphological features, ecology, and distribution of poorly studied molluscan genera of the Colinae subfamily (Bastropoda, Buccinidae) from the far eastern seas of Russia  

Science.gov (United States)

Data on the distribution of six genera of poorly studied buccinids of the Colinae subfamily (Neogastropoda, Buccinidae), namely, Colus Röding, 1799; Plicifusus Dall, 1902; Retifusus Dall, 1916; Aulacofusus Dall, 1918; Pararetifusus Kosuge, 1967; and Latisipo Dall, 1916, are presented. These mollusks are widely spread in the North Pacific region dwelling predominantly over loose sediments in a wide range of sea depths. Based on the morphology and contents of their digestive tracts, it is assumed that the representatives of the genera studied are predators with diverse diets. It is supposed that the increase in the dwelling depths had no significant influence on the feeding ecology of the species studied. Meanwhile, the lower abundance of preys at greater depths caused the lower population densities and modifications in the proboscis structure of selected taxa.

Kosyan, A. R.

2007-08-01

240

Constraints of bioenergetics on the ecology and distribution of vertebrate ectotherms: Progress report for period 1 January 1987 to 31 December 1987  

Energy Technology Data Exchange (ETDEWEB)

We quantified the constraints of bioenergetics on the ecology and distribution of vertebrate ectotherms. We completed studies on the thermoregulation of largemouth bass, on the bioenergetics of the slider turtle, Trachemys scripta, and on the role of temperature dependent sex determination in the extinction of dinosaurs. We also began research to develop the three dimensional bioenergetic climate space for freshwater turtles, to determine the role of incubation temperature on the post hatching growth rate of the snapping turtle, Chelydra serpentina, to establish the rate of energy expenditure of the slider turtle, Trachemys scripta, in the field, to determine the field metabolic rates, body temperatures and water flux rates of the box turtle, Terrapene carolina, and to measure the effect of diet type on the consumption rate, digestion rate and digestive efficiency of adult T. scripta. 60 refs., 9 figs.

Spotila, J.R.; Standora, E.A.

1987-09-01

 
 
 
 
241

Influence of three sour gas processing plants on the ecological distribution of epiphytic lichens in the vicinity of Fox Creek and Whitecourt, Alberta, Canada  

Energy Technology Data Exchange (ETDEWEB)

The ecological distributions of epiphytic lichens have been reduced by SO/sub 2/ emissions from three sour gas processing plants located near Fox Creek and Whitecourt, Alberta. Pollutants tend to concentrate in drainage channels leading to the Athabasca River. These channels parallel the prevailing wind. No sites were encountered which totally lacked lichens but at sites within 1 to 2 km downwind of gas plants and associated S storage blocks, the epiphytic lichen flora was reduced in variety, cover and vitality. An index of atmospheric purity (IAP) was calculated from epiphyte data using selected indicator species and air pollution zones determined. Zone maps of relative air purity were generated using the symap mapping package. Improvements to previous IAP methodologies are suggested. Average sulfation rates, S content, and stable S isotope abundance ratios are discussed as they relate to lichen diversity, vitality and IAP values.

Case, J.W.

1980-01-01

242

Distribution of uranium, Ra-226, Pb-210 and Po-21a in the ecological cycle in mountain regions of central Yugoslavia  

International Nuclear Information System (INIS)

[en] The distributions of U, 226Ra, 210Pb and 210Po in the ecological cycle: soil-hay-domestic animals-meat-cheese-milk were investigated. The levels of radioactivity in soil were found to be normal. The highest result found for U in hay was 100 ug/kg. The amount of 226Ra was highest in beef bones, where the contamination reached 190 pCi/kg. The amount of 210Pb in bones never exceeded 30 pCi/kg and in meat, 5 pCi/kg. In most samples 210Po was below the detection level, but one bone sample reached 90 pCi/kg. U, 226Ra, 210Pb and 210Po in milk all vary from 0 - 2.45 pCi/l. Only 210Pb in cheese was as high as 60 pCi/kg, 226Ra, 210Po and U were hardly detectable. (H.K.)

1980-03-14

243

Systematics and ecology of the brown dog tick, Rhipicephalus sanguineus.  

UK PubMed Central (United Kingdom)

Rhipicephalus sanguineus, the brown dog tick, kennel tick, or pan-tropical dog tick, is probably the most widespread ixodid tick, colonising both human and canine dwellings. It is of great significance in both human and veterinary medicine as a vector of several important pathogens and can also cause clinical illness in heavy infestations of dogs. However, there are still significant taxonomic uncertainties, and it is probable that some records of this tick refer to other species. Most past reviews have been broad-ranging or have focused on the pathogens that R. sanguineus transmits, and relatively few have considered its biology in detail or the issues around its true identity. The present review has paid most attention to the taxonomy of R. sanguineus and to the ecological factors that influence tick survival and distribution, particularly in a climate change context. It is evident that more research is required on the systematics of the R. sanguineus species complex, in order to elucidate the epidemiology and prevention of the diseases that it transmits, and to provide the relevant biological data required for development of predictive models of future tick distribution in a climate change scenario.

Gray J; Dantas-Torres F; Estrada-Peña A; Levin M

2013-04-01

244

Use of molecular markers in biochemical taxonomy of Tischeriidae (Lepidoptera: Tischerioidea) and Elachistidae (Lepidoptera: Gelechioidea) Molekulini? žymen? panaudojimas Tischeriidae (Lepidoptera: Tischerioidea) ir Elachistidae (Lepidoptera: Gelechioidea) drugi? biochemin?je sistematikoje  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The field of molecular biology has expanded greatly in the last ten years and currently many entomologists want to use this technology since it is a new level of carrying out studies of insect ecological systems and taxonomy. The study of mitochondrial DNA (mtDNA) sequences has become the method for...

Paulavi?i?t?, Brigita

245

Metabolic ecology.  

UK PubMed Central (United Kingdom)

Ecological theory that is grounded in metabolic currencies and constraints offers the potential to link ecological outcomes to biophysical processes across multiple scales of organization. The metabolic theory of ecology (MTE) has emphasized the potential for metabolism to serve as a unified theory of ecology, while focusing primarily on the size and temperature dependence of whole-organism metabolic rates. Generalizing metabolic ecology requires extending beyond prediction and application of standardized metabolic rates to theory focused on how energy moves through ecological systems. A bibliometric and network analysis of recent metabolic ecology literature reveals a research network characterized by major clusters focused on MTE, foraging theory, bioenergetics, trophic status, and generalized patterns and predictions. This generalized research network, which we refer to as metabolic ecology, can be considered to include the scaling, temperature and stoichiometric models forming the core of MTE, as well as bioenergetic equations, foraging theory, life-history allocation models, consumer-resource equations, food web theory and energy-based macroecology models that are frequently employed in ecological literature. We conclude with six points we believe to be important to the advancement and integration of metabolic ecology, including nomination of a second fundamental equation, complementary to the first fundamental equation offered by the MTE.

Humphries MM; McCann KS

2013-07-01

246

A revised taxonomy of assistance animals  

Directory of Open Access Journals (Sweden)

Full Text Available The use of animals in various assistive, therapeutic, and emotional support roles has contributed to the uncoordinated expansion of labels used to distinguish these animals. To address the inconsistent vocabulary and confusion, this article proposes a concise taxonomy for classifying assistance animals. Several factors were identified to differentiate categories, including (1) whether the animal performs work or tasks related to an individual’s disability; (2) the typical level of skill required by the animal performing the work or task; (3) whether the animal is used by public service, military, or healthcare professionals; (4) whether training certifications or standards are available; and (5) the existence of legal public access protections for the animal and handler. Acknowledging that some category labels have already been widely accepted or codified, six functional categories were identified: (1) service animal; (2) public service animal; (3) therapy animal; (4) visitation ­animal; (5) sporting, recreational, or agricultural animal; and (6) support animal. This taxonomy provides a clear vocabulary for use by consumers, professionals working in the field, researchers, policy makers, and regulatory agencies.

Lindsay Parenti, MA, BCBA; Anne Foreman, PhD; B. Jean Meade, MD, DVM, MPH, PhD; Oliver Wirth, PhD

2013-01-01

247

Nesting ecology of greater sage-grouse Centrocercus urophasianus at the eastern edge of their historic distribution  

Science.gov (United States)

Greater sage-grouse Centrocercus urophasianus populations in North Dakota declined approximately 67% between 1965 and 2003, and the species is listed as a Priority Level 1 Species of Special Concern by the North Dakota Game and Fish Department. The habitat and ecology of the species at the eastern edge of its historical range is largely unknown. We investigated nest site selection by greater sage-grouse and nest survival in North Dakota during 2005 2006. Sage-grouse selected nest sites in sagebrush Artemisia spp. with more total vegetative cover, greater sagebrush density, and greater 1-m visual obstruction from the nest than at random sites. Height of grass and shrub (sagebrush) at nest sites were shorter than at random sites, because areas where sagebrush was common were sites in low seral condition or dense clay or clay-pan soils with low productivity. Constant survival estimates of incubated nests were 33% in 2005 and 30% in 2006. Variables that described the resource selection function for nests were not those that modeled nest survival. Nest survival was positively influenced by percentage of shrub (sagebrush) cover and grass height. Daily nest survival decreased substantially when percentage of shrub cover declined below about 9% and when grass heights were less than about 16 cm. Daily nest survival rates decreased with increased daily precipitation. ?? 2009 Wildlife Biology, NKV.

Herman-Brunson, K. M.; Jensen, K. C.; Kaczor, N. W.; Swanson, C. C.; Rumble, M. A.; Klaver, R. W.

2009-01-01

248

Ecological niche modeling of coastal dune plants and future potential distribution in response to climate change and sea level rise.  

UK PubMed Central (United Kingdom)

Climate change (CC) and sea level rise (SLR) are phenomena that could have severe impacts on the distribution of coastal dune vegetation. To explore this we modeled the climatic niches of six coastal dunes plant species that grow along the shoreline of the Gulf of Mexico and the Yucatan Peninsula, and projected climatic niches to future potential distributions based on two CC scenarios and SLR projections. Our analyses suggest that distribution of coastal plants will be severely limited, and more so in the case of local endemics (Chamaecrista chamaecristoides, Palafoxia lindenii, Cakile edentula). The possibilities of inland migration to the potential 'new shoreline' will be limited by human infrastructure and ecosystem alteration that will lead to a 'coastal squeeze' of the coastal habitats. Finally, we identified areas as future potential refuges for the six species in central Gulf of Mexico, and northern Yucatán Peninsula especially under CC and SLR scenarios.

Mendoza-González G; Martínez ML; Rojas-Soto OR; Vázquez G; Gallego-Fernández JB

2013-08-01

249

Revisión cráneo-dentaria de Procyon (Carnivora: Procyonidae) en Colombia y Ecuador, con notas sobre su taxonomía y distribución/ Cranio-dental revision of Procyon (Carnivora: Procyonidae) in Colombia and Ecuador, with remarks on its taxonomy and distribution  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish En América del Sur, dos especies del género Procyon han sido históricamente registradas, P. cancrivorus y P. lotor, sin embargo, el conocimiento relacionado con la morfología, la historia natural y su distribución en Colombia y Ecuador es limitado, razón por la cual se ha cuestionado la presencia de P. lotor en esta parte del continente. Con el propósito de contribuir al conocimiento de Procyon en estos países, elaboramos una evaluación morfológica y morfométri (more) ca craneana; utilizamos 24 medidas que examinamos por medio de análisis multivariados y pruebas estadísticas estándar. Aclaramos dudas relacionadas con la presencia de P. lotor en Colombia y actualizamos la distribución de P. cancrivorus en ambos países. Nuestros resultados muestran que las dos especies se encuentran en Colombia y pueden diferenciarse por el ancho del P4 y por la relación longitud del paladar después del M2/longitud total del paladar. Caracteres morfológicos que diferencian las dos especies son: molariformes más masivos con cúspides anchas y redondeadas en P. cancri-vorus, mientras que en P. lotor son más agudas. Procyon lotor se encuentra restringida al norte de Colombia, mientras que P. cancrivorus está más ampliamente distribuida en varias regiones naturales hasta los 2350 msnm en los Andes. Los ejemplares de P. cancrivorus del noroccidente de Colombia presentan características dentarias que concuerdan con las propuestas para la subespecie P. c. proteus y sugerimos que este nombre debería aplicarse a estas poblaciones; sin embargo, el estatus subespecífico de las poblaciones colombianas de P. lotor y de las poblaciones ecuatorianas de P. cancrivorus es incierto. Abstract in english In South America, two species of Procyon have been historically recorded, P. cancrivorus and P. lotor. However, the knowledge related to the morphology, natural history and distribution in Colombia and Ecuador is limited, for this reason the presence of P. lotor in this part of the continent has been questioned. In order to contribute to the knowledge of Procyon in these countries, we developed a cranial morphological and morphometric evaluation; we used twenty-four measu (more) res that were analyzed using multivariate analysis and standard statistical. We elucidated doubts regarding P. lotor's presence in Colombia and updated the distribution of P. cancrivorus in both countries. Our results show that both species are present in Colombia and can be distinguished by the P4 width and the palate length after M2/palate total length ratio. Morphological characters that differentiated the two species are massive molar teeth with broad and round cusps in P. cancrivorus, whereas in P. lotor, are sharper. Procyon lotor is restricted to northern Colombia, while P. cancrivorus is more widely distributed in different natural regions up to 2350 m in the Andes. Procyon cancrivorus specimens from northwestern Colombia have dental characteristics consistent with the proposals for the subspecies P. c. proteus and we suggest that this name should be applied to these populations. Nevertheless, the subspecific status of the colombian populations of P. lotor and ecuatorian populations of P. cancrivorus remain uncertain.

Marín, David; Ramírez-Chaves, Héctor E; Suárez-Castro, Andrés Felipe

2012-12-01

250

Geographic distribution of need and access to health care in rural population: an ecological study in Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Introduction Equity in access to and utilization of health services is a common goal of policy-makers in most countries. The current study aimed to evaluate the distribution of need and access to health care services among Iran's rural population between 2006 and 2009. Methods Census data on population's characteristics in each province were obtained from the Statistical Centre of Iran and National Organization for civil registration. Data about the Rural Health Houses (RHHs) were obtained from the Ministry of Health. The Health Houses-to-rural population ratio (RHP), crude birth rate (CBR) and crude mortality rate (CMR) in rural population were calculated in order to compare their distribution among the provinces. Lorenz curves of RHHs, CMR and CBR were plotted and their decile ratio, Gini Index and Index of Dissimilarity were calculated. Moreover, Spearman rank-order correlation was used to examine the relation between RHHs and CMR and CBR. Results There were substantial differences in RHHs, CMR and CBR across the provinces. CMR and CBR experienced changes toward more equal distributions between 2006 and 2009, while inverse trend was seen for RHHs. Excluding three provinces with markedly changes in data between 2006 and 2009 as outliers, did not change observed trends. Moreover; there was a significant positive relationship between CMR and RHP in 2009 and a significant negative association between CBR and RHP in 2006 and 2009. When three provinces with outliers were excluded, these significant associations were disappeared. Conclusion Results showed that there were significant variations in the distribution of RHHs, CMR and CBR across the country. Moreover, the distribution of RHHs did not reflect the needs for health care in terms of CMR and CBR in the study period.

Ahmad Kiadaliri Aliasghar; Najafi Behzad; Haghparast-Bidgoli Hassan

2011-01-01

251

Geographic distribution of need and access to health care in rural population: an ecological study in Iran.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Equity in access to and utilization of health services is a common goal of policy-makers in most countries. The current study aimed to evaluate the distribution of need and access to health care services among Iran's rural population between 2006 and 2009. METHODS: Census data on population's characteristics in each province were obtained from the Statistical Centre of Iran and National Organization for civil registration. Data about the Rural Health Houses (RHHs) were obtained from the Ministry of Health. The Health Houses-to-rural population ratio (RHP), crude birth rate (CBR) and crude mortality rate (CMR) in rural population were calculated in order to compare their distribution among the provinces. Lorenz curves of RHHs, CMR and CBR were plotted and their decile ratio, Gini Index and Index of Dissimilarity were calculated. Moreover, Spearman rank-order correlation was used to examine the relation between RHHs and CMR and CBR. RESULTS: There were substantial differences in RHHs, CMR and CBR across the provinces. CMR and CBR experienced changes toward more equal distributions between 2006 and 2009, while inverse trend was seen for RHHs. Excluding three provinces with markedly changes in data between 2006 and 2009 as outliers, did not change observed trends. Moreover; there was a significant positive relationship between CMR and RHP in 2009 and a significant negative association between CBR and RHP in 2006 and 2009. When three provinces with outliers were excluded, these significant associations were disappeared. CONCLUSION: Results showed that there were significant variations in the distribution of RHHs, CMR and CBR across the country. Moreover, the distribution of RHHs did not reflect the needs for health care in terms of CMR and CBR in the study period.

Ahmad Kiadaliri A; Najafi B; Haghparast-Bidgoli H

2011-01-01

252

Ecology and distribution of Bulinus truncatus in the Middle East: With comments on the effect of some human activities in their relationship to the snail host on the incidence of bilharziasis haematobia in the Middle East and Africa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The author gives a comprehensive account of the present status of knowledge regarding the ecology and distribution of Bulinus truncatus, the intermediate host of Schistosoma haematobium in the Middle East and North Africa. He discusses in detail the types of habitat favoured by this snail, its life-...

Watson, J. M.

253

Taxonomy of Campylobacter, Arcobacter, Helicobacter and related bacteria: current status, future prospects and immediate concerns  

DEFF Research Database (Denmark)

The taxonomy of the genus Campylobacter has changed dramatically since its inception in 1963. At that time the genus comprised just two species. At present, taxa that were once assigned to Campylobacter may belong to one of over 50 species distributed among six genera. Most of these taxa belong to a phylogenetically distinct group referred to as either ribosomal RNA (rRNA) superfamily VI or the epsilon division of the class Proteobacteria. The taxonomic diversity of the group is matched by the diverse habitats in which they may be found, and by the wide range of diseases that they are associated with. Recognition of their clinical and economic importance has resulted in intense interest in the group, and the application of increasingly sophisticated isolation, detection and chemotaxonomic methods continues to elucidate new aspects of their biodiversity. However, despite the advances in new bacterial systematics, there remain a number of important issues concerning the classification of various campylobacterial taxa that require careful consideration. Ultimately, these issues are relevant to many working in the field of applied microbiology, including clinicians, veterinarians, epidemiologists and taxonomists. The purpose of this article is briefly to review the major developments in the taxonomy of Campylobacter from its inception to the present day; summarize the most recent changes in the field; analyse current topical issues of special relevance to applied microbiologists, including identification of the bacteria; and speculate on future prospects for campylobacterial taxonomy.

On, Stephen L.W.

2001-01-01

254

Biochemical identification and numerical taxonomy of Aeromonas spp. isolated from environmental and clinical samples in Spain.  

UK PubMed Central (United Kingdom)

AIMS: To study the phenotypic characteristics of Aeromonas spp. from environmental and clinical samples in Spain and to cluster these strains by numerical taxonomy. METHODS AND RESULTS: A collection of 202 Aeromonas strains isolated from bivalve molluscs, water and clinical samples was tested for 64 phenotypic properties; 91% of these isolates were identified at species level. Aeromonas caviae was predominant in bivalve molluscs and Aerom. bestiarum in freshwater samples. Cluster analyses revealed eight different phena: three containing more than one DNA-DNA hybridization group but including strains that belong to the same phenospecies complex (Aerom. hydrophila, Aerom. sobria and Aerom. caviae), Aerom. encheleia, Aerom. trota and three containing unidentified Aeromonas strains isolated from bivalve molluscs. CONCLUSIONS:Aeromonas spp. are widely distributed in environmental and clinical sources. A selection of 16 of the phenotypical tests chosen allowed the identification of most isolates (91%), although some strains remain unidentified, mainly isolates from bivalve molluscs, suggesting the presence of new Aeromonas species. Numerical taxonomy was not in total concordance with the identification of the studied strains. SIGNIFICANCE AND IMPACT OF THE STUDY: Numerical taxonomy of Aeromonas strains isolated from different sources revealed the presence of potentially pathogenic Aeromonas spp., especially in bivalve molluscs, and phena with unidentified strains that suggest new Aeromonas species.

Miñana-Galbis D; Farfán M; Lorén JG; Fusté MC

2002-01-01

255

Taxonomía y distribución de los anofelinos en el estado de Veracruz, México (Diptera: Culicidae, Anophelinae)/ Taxonomy and distribution of the anopheline mosquitoes in the state of Veracruz, Mexico (Diptera: Culicidae, Anophelinae)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La malaria o paludismo es una enfermedad humana causada por protozoarios del género Plasmodium y es transmitida por hembras de mosquito de ciertas especies de Anopheles. Se estima que en México el 33.1% de la población vive en áreas donde puede ocurrir la transmisión de la malaria. Veracruz es un estado donde la enfermedad es endémica debido a diversos factores que lo hacen una zona de riesgo para la transmisión, entre ellos las condiciones climáticas y la migraci (more) ón humana. Por lo anterior, en este trabajo se presentan las bases para la reactivación de la vigilancia entomológica del paludismo en el estado de Veracruz, para lo cual se provee la diagnosis ilustrada de la larva, la pupa y los adultos de ambos sexos de las especies de anofelinos del estado, así como las claves taxonómicas que permiten su reconocimiento, con base en el examen de ejemplares recolectados o depositados en colecciones entomológicas de referencia. También se obtuvieron mapas de distribución conocida y potencial de las especies por medio de GARP. Se mencionan además algunos datos bionómicos y la importancia médica de cada especie. Se conocen en Veracruz 18 especies de anofelinos, agrupadas en dos géneros, Chagasia con una especie y Anopheles con 17 pertenecientes a los subgéneros An. (Anopheles), An. (Kerteszia) y An. (Nyssorhynchus). Se reconocen cuatro grupos de especies de acuerdo a su capacidad de transmisión de plasmodios y por su amplitud de distribución: el grupo de alto riesgo constituido por 2 especies; el grupo de riesgo moderado o regional, con 8 especies; el de escaso riesgo, con 3 especies y el de riesgo nulo con 5 especies. Prácticamente todo el estado posee vectores potenciales por lo que debe reestablecerse la vigilancia permanente de sus poblaciones. Este trabajo aporta elementos de juicio para que el estado pueda ser, en un futuro cercano, certificado como área libre de paludismo. Abstract in english Malaria is a human disease caused by four species of the protozoon genus Plasmodium which are transmitted by Anophelinae female mosquitoes of some species of the genus Anopheles. It has been estimated that in Mexico 33.1% of the human population lives in areas where the transmission of malaria is possible. The risk area includes the State of Veracruz that has been a traditional endemic zone in the past. Factors as weather, human density and human migration elevate the pot (more) ential transmission risk. In this study, basic information needed for the reactivation of the entomological surveillance in the Veracruz State is provided, presenting the check-list with the illustrated diagnosis of larva, pupa, adult male and female, and taxonomic keys for the identification of species based in all postembryonic developmental stages. The known and potential distribution maps were obtained using GARP. Some bionomic data and the medical importance of the species are also mentioned. There are 18 Anophelinae species in Veracruz, grouped in two genera, Chagasia with one species and Anopheles with 17, pertaining to three subgenera An. (Anopheles), An (Kerteszia) and An. (Nyssorhynchus). According to the plasmodium transmission capability and distribution range, four groups of species are recognized: the high risk group, with 2 species; the median risk or regional risk group, with 8 species; the low risk group, with 3 species and the no risk group with 5 species. Potential malaria vectors are present throughout almost the entire state, so permanent surveillance of the anopheline populations must be reestablished. This study contributes strong elements for the future certification of the Veracruz State as an area free from malaria.

Beltrán-Aguilar, Adriana; Ibáñez-Bernal, Sergio; Mendoza-Palmero, Fredy; Sandoval-Ruiz, César A.; Hernández-Xoliot, Ruth A.

2011-12-01

256

Ecological Status of a Margaritifera margaritifera (Linnaeus, 1758) Population at the Southern Edge of its Distribution (River Paiva, Portugal).  

UK PubMed Central (United Kingdom)

An important population of the critically endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) was surveyed at the edge of its southern distribution (River Paiva, Portugal). Although an earlier study suggested that this population had a very low number of individuals (<500), a narrow distribution, and was mainly comprised by old specimens our data contradict these findings. Our assessment estimated a population with probably more than 5,000 individuals distributed across 80 km of the river length. From the 32 sites surveyed, 19 contained M. margaritifera with higher abundances verified in the middle and upper parts of the river (a maximum of 78 ind. per 100 m of river stretch was recorded). The pearl mussels showed a clear preference for areas near the banks, in shallow water, sandier and gravel sediments, and a high degree of riparian vegetation cover. The population structure was skewed with a very high percentage of large (and old) animals but 3.7 % of the individuals collected were juveniles (<60 mm in length); therefore, this population can be considered functional. Environmental characterization indicated that this river is still in excellent or good condition although some areas showed deterioration due to discharge of domestic effluents. The main conservation requirements of M. margaritifera in the River Paiva include maintaining the water quality (and if possible stopping the discharge of domestic effluents), increasing riparian vegetation cover, removing several weirs to increase connectivity, and increasing trout density.

Sousa R; Amorim A; Sobral C; Froufe E; Varandas S; Teixeira A; Lopes-Lima M

2013-07-01

257

Taxonomy, distribution and population structure of invasive Corbiculidae (Mollusca, Bivalvia) in the Suquía River basin, Córdoba, Argentina/ Taxonomía, distribución y estructura poblacional de Corbiculidae (Mollusca, Bivalvia) invasores en la cuenca del Río Suquía, Córdoba, Argentina  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Las especies invasoras son una de las causas más importantes de la pérdida de biodiversidad y de las alteraciones que se producen en los servicios ecosistémicos; en ello reside la importancia de la detección de estas especies y su estudio. Las almejas asiáticas (Corbiculidae) son organismos invasores que ingresaron accidentalmente en el Río de La Plata, Argentina, presuntamente en la década de los 1960'. Los objetivos del presente trabajo fueron identificar las esp (more) ecies de corbicúlidos y determinar su distribución en distintas localidades a lo largo de la cuenca del Río Suquía, un área extensa localizada en el centro de Argentina. Asimismo, la estructura poblacional fue evaluada mensualmente durante el periodo de un año, en un sitio de la ciudad de Córdoba caracterizado por una alta influencia humana. Se reporta por primera vez la presencia de Corbicula fluminea (Müller, 1774) y Corbicula largillierti (Philippi, 1844) en la cuenca del Rio Suquía. La primera sólo se encontró en un ambiente léntico (embalse San Roque), mientras que la segunda especie también se encontró a lo largo de los afluentes y arroyos de la cuenca. Corbicula largillierti mostró una variación en la densidad media, considerando los diferentes sitios; asimismo en la biomasa y las clases de tamaño en un mismo sitio, durante el período de estudio. La composición relativa de los sedimentos, la fluctuación del caudal y la contaminación humana podrían ser las responsables de las diferencias observadas. Abstract in english Invasive species are one of the most significant causes of biodiversity loss and changes in ecosystem services, which underlines the importance of their detection and their study. The Asian clams (Corbiculidae) are invasive organisms that accidentally entered the La Plata River, Argentina, presumably in the 1960s. The objectives of the present study were to identify the corbiculid species and to determine their distribution at several locations along the Suquía River bas (more) in, an extended area in central Argentina. In addition, population structure was evaluated monthly during one year, at a site in the city of Córdoba that is characterized by high human influence. The presence of Corbicula fluminea (Müller, 1774) and Corbicula largillierti (Philippi, 1844) in the Suquía River basin is reported for the first time. The former species was found only in a lentic environment (San Roque reservoir), while the latter was also found along the tributary rivers and brooks of the basin. Corbicula largillierti showed variations in average density between the different sites and also in biomass and size classes throughout the study period at the site at Córdoba city. The relative composition of the sediments, flow fluctuation and human pollution may be responsible for the observed differences.

Reyna, Paola B.; Morán, Ariana G.; Tatián, Marcos

2013-06-01

258

Ecological Indicators ????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The ultimate aim of Ecological Indicators is to integrate the monitoring and assessment of ecological and environmental indicators with management practices. The journal provides a forum for the discussion of the applied scientific development and review of traditional indicator approaches as...

259

Ecological Complexity ?????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ecological Complexity is an international journal devoted to the publication of high quality, peer-reviewed articles on all aspects of biocomplexity in the environment, theoretical ecology, and special issues on topics of current interest. The scope of the journal is wide and interdisciplinar...

260

Multicast Transport Protocols: A Survey and Taxonomy  

UK PubMed Central (United Kingdom)

Network support for multicast has triggered the development of group communication applications such asmultipoint data dissemination and multi-party conferencing tools. To support these applications, several multicasttransport protocols have been proposed and implemented.Multicast transport protocols have been an area of active research for the past couple of years. This documenttries to summarize the activities in this work-in-progress area by surveying several multicast transport protocols.The paper also presents a taxonomy to classify the surveyed protocols according to several distinct features,discusses the rationale behind the protocol's design decisions, and presents some current research issues in multicastprotocol design.1 IntroductionMulticast transport mechanisms have been a topic of intense research and development efforts over the past couple ofyears. Both the Internet Engineering and Internet Research Task Forces (IETF and IRTF) have been heavily involvedin co...

Katia Obraczka

 
 
 
 
261

THE APPLICATION OF PIMKAT TAXONOMY IN CAREER TRAINING / Aplikace taxonomie PIMKAT v profesní príprav?  

Directory of Open Access Journals (Sweden)

Full Text Available Contemporary pedagogical approaches to the career training of new police officers require a change in attitude of educators shifting the focus from traditional towards activating teaching methods. For this purpose there are nowadays in use, among others, model situations that make the process of education much more effective. The key issue remains to be the determination of real competences and the evaluation of students' performance. The performance evaluation of police trainees is a difficult and responsible endeavour as well as a significant element of the career training process. Many experienced educators often face difficulties in the course of their work that lead to questions - "What, when and based on what criteria should they evaluate?" Primarily, it is the determination of those criteria and their formulation with focus on their unambiguousness that optimizes use of practical "manuals" - taxonomies. In order to define objectives in the psychomotor domain so called PIMKAT taxonomy was developed at the Department of Pedagogy of the Philosophical Faculty of Pavol Jozef Šafárik University in Košice, whose practical application in career training is what the author deals with in the given contribution. The application of PIMKAT taxonomy gives subjects of the evaluation a groundwork for the formulation of conclusions based on the comparison between the achieved and intended state (the objective of education).Moderní pedagogické prístupy v profesní príprave nových policistu vyžadují zmenu dosavadního prístupu pedagogo od klasických metod výuky k aktivi-za?ním metodám. V sou?asné dobe jsou k tomuto ú?elu využívaný mimo jiné modelové situace, které významne zefektiv?ují eduka?ní proces. Zásadní otázkou zustává zjištení reálných kompetencí a hodnocení výkonu stu-dujících.Hodnocení výkonu policejních adeptu je složitou, zodpovednou ?inností a významnou složkou procesu edukace profesní prípravy. Rada méne zkušených pedagogu nará-ží ?asto ve své práci na problémy „Co, kdy a podle jakých kritérií hodnotit?". Zejména stanovení kritérií hodnocení a jejich formulace s p?ihlédnutím k jejich jednozna?nosti optimalizuje užití praktických „návodu" - taxonomií.Pro stanovení cílu výuky v psychomotorické oblasti byla formulována na katedre pedagogiky FF UPJŠ taxonomie PIMKAT, jejíž praktickou aplikací v profesní príprave se autor zabývá ve svém p?íspévku.Využití taxonomie PIMKAT prináší subjektum hodnocení podklad pro formulaci závéru na základé srovnání dosaženého stavu se stavem plánovaným (cílem výuky).

Zlámal Ji?í

2010-01-01

262

Tick species infesting ruminants in Italy: ecological and bio-climatic factors affecting the different regional distribution.  

UK PubMed Central (United Kingdom)

The distribution of tick species able to infest ruminants in Italy is briefly reviewed on the basis of published records and new data obtained in several surveys carried out mainly in northern Italy. The most frequent and abundant tick species found on ruminants throughout Italy are Ixodes ricinus and Dermacentor marginatus, the first gradually replacing its association with sheep by the association with wild ruminants. Rhipicephalus bursa was mainly found on cattle while R. turanicus, which is considered one of the most sheep-associated species, was found only on wild boar. Haemaphysalis punctata, H. sulcata and H. parva are the other tick species quite frequently found on small ruminants when they are reared on pastures mainly in central-southern Italy. However, the land exploitation of these last decades has dramatically reduced the diversity of Italian environment and significantly modified the distribution and the abundance of ticks causing a heavy spread of the tick species characterized by a strong adaptability such as I. ricinus and R. sanguineus. If this trend continues, it is possible to hypothesise that few "resistant" tick species will gradually replace most of the others. This hypothesis seems to be confirmed by the high percentage observed for I. ricinus (57.4%) and R. sanguineus (35.73%) out of 8,712 specimens collected from several different hosts and from the environment.

Genchi C; Manfredi MT

1999-09-01

263

Ecological thresholds at the savanna-forest boundary: how plant traits, resources and fire govern the distribution of tropical biomes.  

Science.gov (United States)

Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold is reached when an ecosystem has sufficient canopy cover to suppress fire by excluding grasses. Surpassing either threshold is dependent upon long fire-free intervals, which are rare in mesic savanna. On high-resource sites, the thresholds are reached quickly, increasing the probability that savanna switches to forest, whereas low-resource sites are likely to remain as savanna even if fire is infrequent. Species traits influence both thresholds; saplings of savanna trees accumulate bark thickness more quickly than forest trees, and are more likely to become fire resistant during fire-free intervals. Forest trees accumulate leaf area more rapidly than savanna trees, thereby accelerating the transition to forest. Thus, multiple factors interact with fire to determine the distribution of savanna and forest by influencing the time needed to reach these thresholds. Future work should decipher multiple environmental controls over the rates of tree growth and canopy closure in savanna. PMID:22554474

Hoffmann, William A; Geiger, Erika L; Gotsch, Sybil G; Rossatto, Davi R; Silva, Lucas C R; Lau, On Lee; Haridasan, M; Franco, Augusto C

2012-05-04

264

Ecological thresholds at the savanna-forest boundary: how plant traits, resources and fire govern the distribution of tropical biomes.  

UK PubMed Central (United Kingdom)

Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold is reached when an ecosystem has sufficient canopy cover to suppress fire by excluding grasses. Surpassing either threshold is dependent upon long fire-free intervals, which are rare in mesic savanna. On high-resource sites, the thresholds are reached quickly, increasing the probability that savanna switches to forest, whereas low-resource sites are likely to remain as savanna even if fire is infrequent. Species traits influence both thresholds; saplings of savanna trees accumulate bark thickness more quickly than forest trees, and are more likely to become fire resistant during fire-free intervals. Forest trees accumulate leaf area more rapidly than savanna trees, thereby accelerating the transition to forest. Thus, multiple factors interact with fire to determine the distribution of savanna and forest by influencing the time needed to reach these thresholds. Future work should decipher multiple environmental controls over the rates of tree growth and canopy closure in savanna.

Hoffmann WA; Geiger EL; Gotsch SG; Rossatto DR; Silva LC; Lau OL; Haridasan M; Franco AC

2012-07-01

265

Towards a Taxonomy of Virtual Reality User Interfaces  

UK PubMed Central (United Kingdom)

Virtual Reality-based user interfaces (VRUIs) are expected to bring about a revolution in computing. VR can potentially communicate large amounts of data in an easily understandable format. VR looks very promising, but it is still a very new interface technology for which very little application-oriented knowledge is available. As a basis for such a future VRUI-design theory, a taxonomy of VRUIs is required. In this paper, a general model of human-computer communication is formulated. This model constitutes a frame for the integration of partial taxonomies of human computer interaction that are found in the literature. The whole constitutes a general user interface taxonomy. The field of VRUIs is described and delimited with respect to this taxonomy. 1. Introduction Virtual Reality (VR) is getting an increasing amount of attention in both the scientific and business community. While at first only the entertainment value of VR was widely accepted, more and more people are getting now ...

M. K. D. Coomans; H. J. P. Timmermans

266

First data on the distribution and ecology of Vibrio spp. of the Straits of Magellan (South America).  

UK PubMed Central (United Kingdom)

During the austral summer of 1991 a study was carried out on the presence and distribution of the genus Vibrio in the Straits of Magellan. Vibrios strains were isolated using membrane filters and Marine Agar 2216 in anaerobiosis. Variations of the populations of total heterotrophic bacteria and vibrios were observed both on the surface and along the column of water. All vibrios are psychrotrophic and were grouped in 4 cluster among which cluster 1, identified as presumed V. anguillarum, seems the most important including 73% of strains. A certain habitat segregation of clusters was noted. Cluster 4 was found only in a deep and permanently colder water mass. The relations between 20 environmental parameters and the bacterial population were also studied. Significant positive correlations were observed between the vibrios population and various fractions of suspended particulate matter.

Monticelli LS; Crisafi E

1995-07-01

267

Dynamics of market correlations Taxonomy and portfolio analysis  

CERN Document Server

The time dependence of the recently introduced minimum spanning tree description of correlations between stocks, called the ``asset tree'' have been studied to reflect the economic taxonomy. The nodes of the tree are identified with stocks and the distance between them is a unique function of the corresponding element of the correlation matrix. By using the concept of a central vertex, chosen as the most strongly connected node of the tree, an important characteristic is defined by the mean occupation layer (MOL). During crashes the strong global correlation in the market manifests itself by a low value of MOL. The tree seems to have a scale free structure where the scaling exponent of the degree distribution is different for `business as usual' and `crash' periods. The basic structure of the tree topology is very robust with respect to time. We also point out that the diversification aspect of portfolio optimization results in the fact that the assets of the classic Markowitz portfolio are always located on ...

Onnela, J P; Kaski, K; Kertész, J; Kanto, A

2003-01-01

268

Dynamics of market correlations: taxonomy and portfolio analysis.  

UK PubMed Central (United Kingdom)

The time dependence of the recently introduced minimum spanning tree description of correlations between stocks, called the "asset tree" has been studied in order to reflect the financial market taxonomy. The nodes of the tree are identified with stocks and the distance between them is a unique function of the corresponding element of the correlation matrix. By using the concept of a central vertex, chosen as the most strongly connected node of the tree, an important characteristic is defined by the mean occupation layer. During crashes, due to the strong global correlation in the market, the tree shrinks topologically, and this is shown by a low value of the mean occupation layer. The tree seems to have a scale-free structure where the scaling exponent of the degree distribution is different for "business as usual" and "crash" periods. The basic structure of the tree topology is very robust with respect to time. We also point out that the diversification aspect of portfolio optimization results in the fact that the assets of the classic Markowitz portfolio are always located on the outer leaves of the tree. Technical aspects such as the window size dependence of the investigated quantities are also discussed.

Onnela JP; Chakraborti A; Kaski K; Kertész J; Kanto A

2003-11-01

269

Dynamics of market correlations: taxonomy and portfolio analysis.  

Science.gov (United States)

The time dependence of the recently introduced minimum spanning tree description of correlations between stocks, called the "asset tree" has been studied in order to reflect the financial market taxonomy. The nodes of the tree are identified with stocks and the distance between them is a unique function of the corresponding element of the correlation matrix. By using the concept of a central vertex, chosen as the most strongly connected node of the tree, an important characteristic is defined by the mean occupation layer. During crashes, due to the strong global correlation in the market, the tree shrinks topologically, and this is shown by a low value of the mean occupation layer. The tree seems to have a scale-free structure where the scaling exponent of the degree distribution is different for "business as usual" and "crash" periods. The basic structure of the tree topology is very robust with respect to time. We also point out that the diversification aspect of portfolio optimization results in the fact that the assets of the classic Markowitz portfolio are always located on the outer leaves of the tree. Technical aspects such as the window size dependence of the investigated quantities are also discussed. PMID:14682849

Onnela, J-P; Chakraborti, A; Kaski, K; Kertész, J; Kanto, A

2003-11-13

270

Diptera vectors of avian Haemosporidian parasites: untangling parasite life cycles and their taxonomy.  

UK PubMed Central (United Kingdom)

Haemosporida is a large group of vector-borne intracellular parasites that infect amphibians, reptiles, birds, and mammals. This group includes the different malaria parasites (Plasmodium spp.) that infect humans around the world. Our knowledge on the full life cycle of these parasites is most complete for those parasites that infect humans and, to some extent, birds. However, our current knowledge on haemosporidian life cycles is characterized by a paucity of information concerning the vector species responsible for their transmission among vertebrates. Moreover, our taxonomic and systematic knowledge of haemosporidians is far from complete, in particular because of insufficient sampling in wild vertebrates and in tropical regions. Detailed experimental studies to identify avian haemosporidian vectors are uncommon, with only a few published during the last 25 years. As such, little knowledge has accumulated on haemosporidian life cycles during the last three decades, hindering progress in ecology, evolution, and systematic studies of these avian parasites. Nonetheless, recently developed molecular tools have facilitated advances in haemosporidian research. DNA can now be extracted from vectors' blood meals and the vertebrate host identified; if the blood meal is infected by haemosporidians, the parasite's genetic lineage can also be identified. While this molecular tool should help to identify putative vector species, detailed experimental studies on vector competence are still needed. Furthermore, molecular tools have helped to refine our knowledge on Haemosporida taxonomy and systematics. Herein we review studies conducted on Diptera vectors transmitting avian haemosporidians from the late 1800s to the present. We also review work on Haemosporida taxonomy and systematics since the first application of molecular techniques and provide recommendations and suggest future research directions. Because human encroachment on natural environments brings human populations into contact with novel parasite sources, we stress that the best way to avoid emergent and reemergent diseases is through a program encompassing ecological restoration, environmental education, and enhanced understanding of the value of ecosystem services.

Santiago-Alarcon D; Palinauskas V; Schaefer HM

2012-11-01

271

Distribution, sources, and ecological risks of organochlorine pesticides in surface sediments from the Yellow River Estuary, China.  

UK PubMed Central (United Kingdom)

Thirty-four surface sediment samples were analyzed for organochlorine pesticides (OCPs), in order to provide information on levels, distribution and sources of these compounds in the Yellow River Estuary, China. The levels of the organochlorine pesticides in samples were detected by the technique of soxhlet extraction followed by analysis by gas chromatography (GC) coupled with a mass selective detector. Total concentrations of OCPs ranged widely from 0.06 to 53.4 ng g(-1), with a mean value of 44.84 ng g(-1), at the mid level of pesticide concentrations compared to those reported in other regions worldwide. HCHs were the predominant species in the study area. The ratios of ?-HCH/?-HCH indicated that the technical HCH contamination was mainly due to a recent input of lindane in upper reach of Yellow River Estuary. The ratios of (DDD + DDE)/DDTs and DDD/DDE suggested that DDTs in sediments came mainly from the degradation of historical DDT in the environment, and DDT could be much easier to degrade into DDD under anaerobic conditions. Principal component analysis (PCA) could conclude that most of the OCPs came from early input and historical degradation products in the study area. Based on the sediment quality guidelines, ?-HCH and p'p-DDE would be of more concern for the ecotoxicological risk in this study area.

Da C; Liu G; Tang Q; Liu J

2013-10-01

272

Socio-ecology of the marsh rice rat (Oryzomys palustris) and the spatio-temporal distribution of Bayou virus in coastal Texas.  

UK PubMed Central (United Kingdom)

Along the southeastern coast of the United States of America (USA), the marsh rice rat (Oryzomys palustris) is the primary host for the hantavirus, genotype Bayou. According to the socio-ecological model for a territorial, polygamous species, females should be distributed across space and time by habitat resources and predation risks, whereas males should space themselves according to the degree of female aggregation and reproductive synchrony. To investigate how females affect the male-male transmission paradigm of Bayou virus, rodents were captured, marked, released in two macrohabitat types and followed across a 30-month period. Microhabitat cover variables were quantified around the individual trap stations. A geodatabase was created from habitat and rodent capture data and analysed in a geographical information system. The ratio of breeding to non-breeding females was ~1:1, with breeding females overly dispersed and non-breeding females randomly dispersed. Spatial analyses revealed both macro- and microhabitat preferences in females. Compared to seronegatives, higher proportions of seropositive adult males were found consistently within closer proximities to breeding females but not to non-breeding females, indicating that male locations were not driven simply by habitat selection. Activities to acquire dispersed receptive females could be an important driver of Bayou virus transmission among male hosts. Herein, we describe an interdisciplinary effort providing a novel approach to elucidate the complexity of hantavirus trafficking and maintenance in rodent populations of a coastal marsh ecosystem.

Holsomback TS; Van Nice CJ; Clark RN; McIntyre NE; Abuzeineh AA; Salazar-Bravo J

2013-05-01

273

An illustrated key to the soft-bottom caprellids (Crustacea: Amphipoda) of the Iberian Peninsula and remarks to their ecological distribution along the Andalusian coast  

Science.gov (United States)

The soft-bottom caprellids of the Iberian Peninsula are revised. Nineteen species have been reported so far, 42 % being endemic to the Mediterranean Sea. The lateral view of all of them is provided, together with an illustrated key for all the species. An ecological study was also conducted during 2007-2010 along the Andalusian coast to explore the relationships of caprellids with abiotic data. A total of 90 stations (0-40 m deep) were sampled and 40 contained caprellids. Along the Atlantic, caprellids were present in only 20 % of the stations, while along the Mediterranean coast, caprellids were present in the 75 % of the sampling sites. Furthermore, the abundance of caprellids was also higher in the Mediterranean coast. The dominant species was Pseudolirius kroyeri (present in 24 stations and showing the highest abundances with 1,780 ind/m2), followed by Phtisica marina (22 stations) and Pariambus typicus (11 stations). According to CCA and BIO-ENV, sediment type, P, pH and oxygen were the parameters that better explained the distribution of caprellids. Although the three dominant species were found in all types of sediment, the univariate approach showed that P. kroyeri was significantly more abundant in fine sediments (silt-clay and very fine sands) than in gross sediments (coarse and very coarse sands). The majority of studies dealing with caprellids from the Iberian Peninsula have been focused on shallow waters and further efforts are needed to explore biodiversity of deeper areas.

Guerra-García, José M.; Navarro-Barranco, Carlos; Corzo, Juan; Cobos-Muñoz, Vanessa; García-Adiego, Emilio M.; Giménez, Francisco Sempere; García-Gómez, J. Carlos

2013-06-01

274

Socio-ecology of the marsh rice rat (Oryzomys palustris) and the spatio-temporal distribution of Bayou virus in coastal Texas.  

Science.gov (United States)

Along the southeastern coast of the United States of America (USA), the marsh rice rat (Oryzomys palustris) is the primary host for the hantavirus, genotype Bayou. According to the socio-ecological model for a territorial, polygamous species, females should be distributed across space and time by habitat resources and predation risks, whereas males should space themselves according to the degree of female aggregation and reproductive synchrony. To investigate how females affect the male-male transmission paradigm of Bayou virus, rodents were captured, marked, released in two macrohabitat types and followed across a 30-month period. Microhabitat cover variables were quantified around the individual trap stations. A geodatabase was created from habitat and rodent capture data and analysed in a geographical information system. The ratio of breeding to non-breeding females was ~1:1, with breeding females overly dispersed and non-breeding females randomly dispersed. Spatial analyses revealed both macro- and microhabitat preferences in females. Compared to seronegatives, higher proportions of seropositive adult males were found consistently within closer proximities to breeding females but not to non-breeding females, indicating that male locations were not driven simply by habitat selection. Activities to acquire dispersed receptive females could be an important driver of Bayou virus transmission among male hosts. Herein, we describe an interdisciplinary effort providing a novel approach to elucidate the complexity of hantavirus trafficking and maintenance in rodent populations of a coastal marsh ecosystem. PMID:23733291

Holsomback, Tyla S; Van Nice, Christopher J; Clark, Rachel N; McIntyre, Nancy E; Abuzeineh, Alisa A; Salazar-Bravo, Jorge

2013-05-01

275

Amphibians in Southern Apennine: distribution, ecology and conservation notes in the “Appennino Lucano, Val d’Agri e Lagonegrese” National Park (Southern Italy)  

Directory of Open Access Journals (Sweden)

Full Text Available Italy is the European country with the highest amphibian richness and endemism. However distributional data from some Southern Italy areas are scanty, in particularly for the Basilicata region. In this study, we present the results of field and bibliographic survey on the amphibians of the “Appennino Lucano, Val d’Agri e Lagonegrese” National Park (almost 70,000 ha). We recorded breeding activity of 12 amphibian species in 307 sites, for a total of 493 records. For some endemic species we provide new ecological data, such as new altitudinal limit (Salamandrina terdigitata) or expansion of the annual activity cycle (Bombina pachypus). Indices of diffusion, density and rarity were applied to test the status of each species in the Park. Correspondence analyses showed a clear aquatic habitat partitioning between anurans and urodelans and, concerning the latter, between newts and salamanders, newts being strictly dependent on artificial water bodies. Our results support the growing idea, recently formalized by the IUCN, that maintaining and restoring artificial water bodies may be fundamental for an appropriate conservation management of amphibian communities in Mediterranean rural landscapes.

Antonio Romano; Remo Bartolomei; Antonio Luca Conte; Egidio Fulco

2012-01-01

276

The genus Scolymus Tourn. ex L. (Asteraceae): taxonomy and distribution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A taxonomic study of the genus Scolymus Tourn. ex L. is presented. Seven taxa are recognised, two of them new to science: Scolymus hispanicus subsp. occidentalis F.M. Vázquez, subsp. nov., and S. hispanicus [subsp. hispanicus] i. decoloratus Fiori ex F.M. Vá...

Vázquez, Francisco M.

277

The genus Scolymus Tourn. ex L. (Asteraceae): taxonomy and distribution  

Directory of Open Access Journals (Sweden)

Full Text Available A taxonomic study of the genus Scolymus Tourn. ex L. is presented. Seven taxa are recognised, two of them new to science: Scolymus hispanicus subsp. occidentalis F.M. Vázquez, subsp. nov., and S. hispanicus [subsp. hispanicus] i. decoloratus Fiori ex F.M. Vázquez,/ nov.; a new combination, S. hispanicus [subsp. hispanicus] var. aggregatus (Ruch.) F.M. Vázquez, comb. & stat. nov., is proposed. The type and full synonymy for each taxon are given. A selection of the specimens studied is presented in Appendix I. Some of the taxa are illustrated in figures.Se presenta una revisión taxonómica del género Scolymus Tourn. ex L., en la que se reconocen siete táxones, dos de ellos nuevos para la ciencia: Scolymus hispanicus subsp. occidentalis F.M. Vázquez, subspnov. ., y S. hispanicus [subsp. hispanicus] f. decoloratus Fiori ex F.M. Vázquez,/ nov.; se propone una combinación a nivel de variedad: S. hispanicus [subsp. hispanicus] var. aggregatus (Ruch.) F.M. Vázquez, comb. & stat. nov. Se han revisado todos los sinónimos nomenclaturales y taxonómicos, y se incluye en el Apéndice I un listado de parte del material estudiado. Finalmente, se ilustra mediante figuras una parte de los táxones recogidos en el trabajo.

Vázquez, Francisco M.

2000-01-01

278

[Ecology of mosquitoes (Diptera: Culicidae) in areas of Serra da Bocaina National Park, Brazil. I. Habitat distribution  

UK PubMed Central (United Kingdom)

OBJECTIVE: To assess the mosquito fauna in Serra da Bocaina National Park (PNSB), by collecting information through a general survey, and investigating the population behavior in habitats within the park with different vegetation. METHODS: Human bait collections were conducted once a month for both the forest and households, in diurnal and nocturnal periods, three time a day, throughout 24 months, from January 1991 to December 1992. RESULTS: A total of 11, 808 adult mosquitoes belonging to 28 species were collected. Runchomyia reversa and Anopheles cruzii were the most abundant, reaching 52.5% and 17.9% of the total collected specimens, respectively. In the dense forest, Ru. reversa comprised 59.4% of the total, followed by Ru. frontosa with 10.5%, and An. cruzii with 9.9%. In the high altitude fields and in gallery forest, An. cruzii was the most abundant (48.1%) followed by Ru. reversa (28.1%). Inside households An. cruzii was also the most prominent species, representing 73.7% of the total for that location. Coquillettidia chrysonotum was the only species mainly seen in the household surroundings, where its distribution was: 14.9% (indoors), 19.4% (close to the house), and 65.7% (outdoors). An. cruzii and Ru. reversa were found throughout the whole year and captured every month. CONCLUSIONS: Mosquitoes in PNSB present an assynanthropic behavior, except for Cq. chrysonotum which lives preferentially in the household environment. Though An. cruzii is an assynantropic species it may approaches live near households and even invades and infest them for the blood meals. The occurrence of Aedes serratus in the household vicinity emphasizes its epidemiological importance as a potential vector of arboviruses. Sabethini are all exclusively sylvatic species.

Guimarães AE; Gentile C; Lopes CM; Sant'Anna A; Jovita AM

2000-06-01

279

Modelling dendritic ecological networks in space: an integrated network perspective.  

Science.gov (United States)

Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of ecological networks, or in 2-D space, may be inadequate for studying the influence of structure and connectivity on ecological processes within DENs. We propose a conceptual taxonomy of network analysis methods that account for DEN characteristics to varying degrees and provide a synthesis of the different approaches within the context of stream ecology. Within this context, we summarise the key innovations of a new family of spatial statistical models that describe spatial relationships in DENs. Finally, we discuss how different network analyses may be combined to address more complex and novel research questions. While our main focus is streams, the taxonomy of network analyses is also relevant anywhere spatial patterns in both network and 2-D space can be used to explore the influence of multi-scale processes on biota and their habitat (e.g. plant morphology and pest infestation, or preferential migration along stream or road corridors). PMID:23458322

Peterson, Erin E; Ver Hoef, Jay M; Isaak, Dan J; Falke, Jeffrey A; Fortin, Marie-Josée; Jordan, Chris E; McNyset, Kristina; Monestiez, Pascal; Ruesch, Aaron S; Sengupta, Aritra; Som, Nicholas; Steel, E Ashley; Theobald, David M; Torgersen, Christian E; Wenger, Seth J

2013-03-04

280

Modelling dendritic ecological networks in space: an integrated network perspective.  

UK PubMed Central (United Kingdom)

Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of ecological networks, or in 2-D space, may be inadequate for studying the influence of structure and connectivity on ecological processes within DENs. We propose a conceptual taxonomy of network analysis methods that account for DEN characteristics to varying degrees and provide a synthesis of the different approaches within the context of stream ecology. Within this context, we summarise the key innovations of a new family of spatial statistical models that describe spatial relationships in DENs. Finally, we discuss how different network analyses may be combined to address more complex and novel research questions. While our main focus is streams, the taxonomy of network analyses is also relevant anywhere spatial patterns in both network and 2-D space can be used to explore the influence of multi-scale processes on biota and their habitat (e.g. plant morphology and pest infestation, or preferential migration along stream or road corridors).

Peterson EE; Ver Hoef JM; Isaak DJ; Falke JA; Fortin MJ; Jordan CE; McNyset K; Monestiez P; Ruesch AS; Sengupta A; Som N; Steel EA; Theobald DM; Torgersen CE; Wenger SJ

2013-05-01

 
 
 
 
281

Urban Ecology  

Science.gov (United States)

When people think about the concept and idea of ecology, they may not immediately picture a bustling urban street or a network of interconnected bike paths. Since 1975, a group of architects and activists have been thinking about exactly those things in terms of urban ecology (and a good deal more to boot), coupling it with a conviction that urban ecology can draw on ecology, public participation and urban planning "to help design and build healthier cities." Given these ideas, it seems logical that this organization has its roots in the Bay Area, and continues to offer up interesting plans and proposals, many of which can be found on the website. One such document is the Walkable Streets Toolkit, which is designed for use by communities that seek to make their streets more pedestrian friendly. Additionally, visitors will want to look at current and past editions of The Urban Ecologist, which is the group's quarterly newsletter.

282

Phytoplankton Ecology  

Science.gov (United States)

This site describes phytoplankton ecology research by marine ecologists at Mote Marine Laboratory (MML), an independent, nonprofit research organization based in Sarasota, Florida. The emphasis of MML's phytoplankton ecology research is the photophysiology of marine algae -- with recent emphasis on the ability to predict and possibly mitigate blooms of the toxic marine dinoflagellate, Gymnodinium breve. The no-frills phytoplankton ecology homepage describes research and offers data (maps, figures, tables) from 1998 and 1999 projects on Red Tide transects, Nutrient and chlorophyll concentrations, and Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) transect data, among several others. The site also offers general information on Red Tides, Red Tide conditions in Southwest Florida, a chronology of historic Red Tide events, and links to related resources.

283

Ecological Economics ?????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The journal is concerned with extending and integrating the study and management of "nature's household" (ecology) and "humankind's household" (economics). This integration is necessary because conceptual and professional isolation have led to economic and environmental policies which are mutually d...

284

Constructing ecologies.  

UK PubMed Central (United Kingdom)

We synthesize the generic properties of ecologically realistic multi-trophic level models and define criteria for ecological realism. We define an "ecospace" in which all ecologically realistic dynamics are confined, and construct "resource rays" that define the resources available to each species at every point in the ecospace. Resource rays for a species are lines from a vertex of maximum resource to the opposite boundary where no resources are available. The growth functions of all biota normally decrease along their resource rays, and change sign from positive to negative. This property prescribes that each species must have a zero isosurface within the ecospace. We illustrate our conditions on a highly cited three trophic level model from population dynamics, showing how to extend this system biologically consistently to a closed ecological system. Our synthesis extends the concept of carrying capacity of population models to explicitly include exhaustion of limiting resources, and so allows for population biology models to be considered as ecologically closed systems with respect to a key limiting nutrient. This approach unifies many theoretical and applied models in a common biogeochemical framework, facilitates better understanding of the key structures of complex ecologies, and suggests strategies for efficient design of experiments.

Cropp R; Norbury J

2012-02-01

285

Biome specificity of distinct genetic lineages within the four-striped mouse Rhabdomys pumilio (Rodentia: Muridae) from southern Africa with implications for taxonomy.  

Science.gov (United States)

Within southern Africa, a link between past climatic changes and faunal diversification has been hypothesized for a diversity of taxa. To test the hypothesis that evolutionary divergences may be correlated to vegetation changes (induced by changes in climate), we selected the widely distributed four-striped mouse, Rhabdomys, as a model. Two species are currently recognized, the mesic-adapted R. dilectus and arid-adapted R. pumilio. However, the morphology-based taxonomy and the distribution boundaries of previously described subspecies remain poorly defined. The current study, which spans seven biomes, focuses on the spatial genetic structure of the arid-adapted R. pumilio (521 specimens from 31 localities), but also includes limited sampling of the mesic-adapted R. dilectus (33 specimens from 10 localities) to act as a reference for interspecific variation within the genus. The mitochondrial COI gene and four nuclear introns (Eef1a1, MGF, SPTBN1, Bfib7) were used for the construction of gene trees. Mitochondrial DNA analyses indicate that Rhabdomys consists of four reciprocally monophyletic, geographically structured clades, with three distinct lineages present within the arid-adapted R. pumilio. These monophyletic lineages differ by at least 7.9% (±0.3) and these results are partly confirmed by a multilocus network of the combined nuclear intron dataset. Ecological niche modeling in MaxEnt supports a strong correlation between regional biomes and the distribution of distinct evolutionary lineages of Rhabdomys. A Bayesian relaxed molecular clock suggests that the geographic clades diverged between 3.09 and 4.30Ma, supporting the hypothesis that the radiation within the genus coincides with paleoclimatic changes (and the establishment of the biomes) characterizing the Miocene-Pliocene boundary. Marked genetic divergence at the mitochondrial DNA level, coupled with strong nuclear and mtDNA signals of non-monophyly of R. pumilio, support the notion that a taxonomic revision of the genus is needed. PMID:22728170

du Toit, Nina; van Vuuren, Bettine Jansen; Matthee, Sonja; Matthee, Conrad A

2012-06-19

286

Biome specificity of distinct genetic lineages within the four-striped mouse Rhabdomys pumilio (Rodentia: Muridae) from southern Africa with implications for taxonomy.  

UK PubMed Central (United Kingdom)

Within southern Africa, a link between past climatic changes and faunal diversification has been hypothesized for a diversity of taxa. To test the hypothesis that evolutionary divergences may be correlated to vegetation changes (induced by changes in climate), we selected the widely distributed four-striped mouse, Rhabdomys, as a model. Two species are currently recognized, the mesic-adapted R. dilectus and arid-adapted R. pumilio. However, the morphology-based taxonomy and the distribution boundaries of previously described subspecies remain poorly defined. The current study, which spans seven biomes, focuses on the spatial genetic structure of the arid-adapted R. pumilio (521 specimens from 31 localities), but also includes limited sampling of the mesic-adapted R. dilectus (33 specimens from 10 localities) to act as a reference for interspecific variation within the genus. The mitochondrial COI gene and four nuclear introns (Eef1a1, MGF, SPTBN1, Bfib7) were used for the construction of gene trees. Mitochondrial DNA analyses indicate that Rhabdomys consists of four reciprocally monophyletic, geographically structured clades, with three distinct lineages present within the arid-adapted R. pumilio. These monophyletic lineages differ by at least 7.9% (±0.3) and these results are partly confirmed by a multilocus network of the combined nuclear intron dataset. Ecological niche modeling in MaxEnt supports a strong correlation between regional biomes and the distribution of distinct evolutionary lineages of Rhabdomys. A Bayesian relaxed molecular clock suggests that the geographic clades diverged between 3.09 and 4.30Ma, supporting the hypothesis that the radiation within the genus coincides with paleoclimatic changes (and the establishment of the biomes) characterizing the Miocene-Pliocene boundary. Marked genetic divergence at the mitochondrial DNA level, coupled with strong nuclear and mtDNA signals of non-monophyly of R. pumilio, support the notion that a taxonomic revision of the genus is needed.

du Toit N; van Vuuren BJ; Matthee S; Matthee CA

2012-10-01

287

Integrative taxonomy for continental-scale terrestrial insect observations.  

UK PubMed Central (United Kingdom)

Although 21(st) century ecology uses unprecedented technology at the largest spatio-temporal scales in history, the data remain reliant on sound taxonomic practices that derive from 18(th) century science. The importance of accurate species identifications has been assessed repeatedly and in instances where inappropriate assignments have been made there have been costly consequences. The National Ecological Observatory Network (NEON) will use a standardized system based upon an integrative taxonomic foundation to conduct observations of the focal terrestrial insect taxa, ground beetles and mosquitoes, at the continental scale for a 30 year monitoring program. The use of molecular data for continental-scale, multi-decadal research conducted by a geographically widely distributed set of researchers has not been evaluated until this point. The current paper addresses the development of a reference library for verifying species identifications at NEON and the key ways in which this resource will enhance a variety of user communities.

Gibson CM; Kao RH; Blevins KK; Travers PD

2012-01-01

288

Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus, Talpidae): implications for taxonomy and conservation.  

UK PubMed Central (United Kingdom)

CONCLUSIONS: The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. Two synonyms of gracilis (atronates and nivatus) should be given full species status, and the taxonomic status of another three potential species should be evaluated using extensive taxon sampling, comprehensive morphological, and morphometric approaches. Consequently, the conservation status of Uropsilus spp. should also be re-evaluated, as most of the species/potential species have very limited distribution.

Wan T; He K; Jiang XL

2013-10-01

289

Genomic Taxonomy of the Genus Prochlorococcus.  

UK PubMed Central (United Kingdom)

The genus Prochlorococcus is globally abundant and dominates the total phytoplankton biomass and production in the oligotrophic ocean. The single species, Prochlorococcus marinus, comprises six named ecotypes. Our aim was to analyze the taxonomic structure of the genus Prochlorococcus. We analyzed the complete genomes of 13 cultured P. marinus type and reference strains by means of several genomic taxonomy tools (i.e., multilocus sequence analysis, amino acid identity, Karlin genomic signature, and genome to genome distance). In addition, we estimated the diversity of Prochlorococcus species in over 100 marine metagenomes from all the major oceanic provinces. According to our careful taxonomic analysis, the 13 strains corresponded, in fact, to ten different Prochlorococcus species. This analysis establishes a new taxonomic framework for the genus Prochlorococcus. Further, the analysis of the metagenomic data suggests that, in total, there may only be 35 Prochlorococcus species in the world's oceans. We propose that the dearth of species observed in this study is driven by high selective pressures that limit diversification in the global ocean.

Thompson CC; Silva GG; Vieira NM; Edwards R; Vicente AC; Thompson FL

2013-08-01

290

Colors and Taxonomy of Tnos and Centaurs  

Science.gov (United States)

The investigation of the surface properties of the minor bodies of the outer Solar System constitutes a major topic in modern planetary science, since they represent the "vestiges" of the leftover planetesimals from the early accretional phases of the outer pre-planetary disk. Because of the faintness of Trans-Neptunian Objects (TNOs) and Centaurs, spectroscopic observations are feasible only for a small number of them. Hence photometry is still the best tool to investigate the surface properties of a significant sample of these objects, retrieving a global view of the whole known population. Here we present new visible and near-infrared photometric observations of 31 objects, executed at the Very Large Telescope of the European Southern Observatory (ESO) between November 2007 and November 2008, in the framework of a second ESO Large Programme devoted to the study of TNOs and Centaurs by means of different techniques (PI: M. A. Barucci). The taxonomic classification of the targets was derived via the G-mode statistical method presented in Fulchignoni et al. 2000 (Icarus, 146, 204) using the Barucci taxonomy for TNOs and Centaurs (Barucci et al. 2005, AJ, 130, 1291), which identifies four classes (with increasingly red colors: BB, BR, IR, RR) that reasonably indicate different composition and/or evolutional history. A comparison with literature data, whenever available, was performed. The obtained complete results will be presented and discussed.

Perna, Davide; Fornasier, S.; Barucci, M. A.; DeMeo, F.; Merlin, F.; Alvarez-Candal, A.; Guilbert, A.; Delsanti, A.; Dotto, E.; Doressoundiram, A.; Protopapa, S.; de Bergh, C.

2009-09-01

291

Nuclear and original DNA application in Oryza taxonomy and phylogeny  

International Nuclear Information System (INIS)

Conventional taxonomy and phylogeny of germplasm are based on the tedious characterization of morphological variation. The ability to assay DNA variation that underlies morphological variation offers great promise as a convenient alternative for the genetic characterization of germplasm. Restriction fragment length polymorphism (RFLP) was used to survey DNA variation in 22 species of the genus Oryza. At the ribosomal DNA (rDNA) multigene family, 15 rDNA spacer length (sl) variants were identified using restriction enzyme Sst1 and wheatrDNA unit as probe. Particular sl variants predominated in certain isozyme groups of O. sativa, indicating a potential of sl ploymorphism in varietal classification. The distribution of sl variants supports the origin of O. sativa and O. nivara from O. rufipogon, and that O. spontanea arose from introgressions among O. sativa, O. nivara, and O. rufipogon. The distribution also suggests that the CCgenome, of all the genomes in the Officinalis complex, may be closest to the Sativa complex genomes, and it affirms the genetic position of the Officinalis complex intermediate between the Sativa and Ridleyi complexes. Variation at the Oryza organelle genomes was probed with a maize mitochondrial gene, atpA, a wheat chloroplast inverted repeat segment, p6. Results indicated that the complexes can be differentiated by their mitochondrial genome, but not their chloroplast genome when digested by Sst1 or BamH1. Therefore, the natural DNA variation in the nuclear and mitochondrial genomes has demonstrated great potential in complementing the conventional basis of taxa classification and phylogeny in the genus Oryza. (Author)

1998-01-01

292

Founding RGB ecology: The ecology of synthesis  

Directory of Open Access Journals (Sweden)

Full Text Available There is an arising need to interpret an amount of ecological information that is more and more available. It is not only the pursuit of an easy handling of a large amount of data, but above all the quest for a deep and multivariate interpretation of many sources of ecological info. To this aim, I introduce here RGB ecology as a new branch of ecology devoted to the cartographic synthesis of ecological information. RGB ecology has the following properties: (1) it can not be separated from GIS cartography; (2) it can compact ecological information along space and time; (3) it can create a decision space for management decisions; (4) it can go beyond the third dimension by using compressive statistical techniques. RGB ecology can also be an effective flanker of several branches of ecology, such as landscape ecology, conservation ecology, urban ecology, forest ecology and so forth.

Alessandro Ferrarini

2012-01-01

293

New data on morphometrics, distribution and ecology of Mioscirtus wagneri (Kittary, 1849) (Orthoptera, Acrididae) in Spain: is maghrebi a well defined subespecies?  

Directory of Open Access Journals (Sweden)

Full Text Available We studied different populations of Mioscirtus wagneri (Kittary, 1859) in Spain assigned to subspecies maghrebi by Fernandes (1968) and obtained some new records for the species. To see if maghrebi is a consistent taxon for the Iberian populations, we performed a morphometric analysis involving 53 individuals from different origins considering body size (front of the head to tip of the abdomen); the shape of pronotum and presence of a second anterior notch or sulcus; length of the antennae and epiphallum, according to the characters used to define subspecies maghrebi. If maghrebi is consistent, we would expect intermediate sizes between wagneri and rogenhoferi, the other two well separated subspecies considered for M.w. However, in our measurements we obtained that body size is not intermediate between M. w. wagneri and M. w. rogenhoferi contrary to expectations if assuming the existence of maghrebi. Body size is similar to wagneri and further, we recorded some of the smallest individuals described so far. Also, the pronotum varied widely across and within populations showing different phenotypes that formerly were used to separate maghrebi and wagneri. Taking into account body size, pronotum, length of antenna and epiphallum, we think that differences between the studied Spanish populations and wagneri form are not enough to assign the studied populations to maghrebi. In the studied area, M.w. shows a narrow ecological niche inhabiting shores or proximities of hipersaline lagoons wherever Suaeda vera (Forsskål 1791, Chenopodiacea) is present, M.w. uses this plant as refuge and food. The species also inhabits bare saline low grounds with scattered S vera. It presents a markedly discontinuous and patchy distribution in Spain, showing up punctually, where the microhabitat is appropriate. We obtained a morphometric variability with a significant association between body size and locality, and between body size and the colour of posterior wings in males. Because of its wide range disjunction, its discontinuous regional distribution and morphological variability, we believe that M.w. is an interesting species to investigate possible substructuring of populations in which we probably may recognize ecological forms or varieties that deserve deeper and further study.Estudiamos distintas poblaciones de Mioscirtus wagneri (Kittary, 1859), considerado como M. w. maghrebi por Fernandes (1968) en España, con algunas nuevas citas para la especie. Para dilucidar si el taxón maghrebi es consistente en nuestras poblaciones, realizamos un análisis morfométrico de 53 ejemplares considerando los mismos caracteres utilizados para establecer dicha subespecie, a citar: tamaño del cuerpo, relieve y forma del pronoto, longitud de la antena y forma del epifalo. El tamaño de los individuos de nuestras poblaciones no es intermedio entre las formas conocidas de M. w. wagneri y M. w. rogenhoferi Saussuare, 1888, como cabría esperar asumiendo la existencia de maghrebi. Nuestras poblaciones no se apartan del tamaño de wagneri e incluso encontramos las menores tallas descritas para este taxón. El relieve del pronoto, y en particular la presencia de un segundo surco, el anterior, es muy variable abarcando en una misma población fenotipos dispares utilizados anteriormente para separar las formas maghrebi y wagneri. Las diferencias entre el tamaño del cuerpo, el pronoto, la longitud de la antena y la forma del epifalo no nos parecen suficientes para asignar como maghrebi al conjunto de las poblaciones estudiadas y separarlas de la subespecie nominada wagneri. M.w. es una especie de requerimientos ecológicos muy restringidos. La hemos encontrado a orillas de lagunas hipersalinas y siempre dependiendo de Suaeda vera (Forsskål, 1791) Chenopodiacea que utiliza como refugio y alimento, en particular en suelos desnudos y salitrosos donde predominan manchas de esa planta. Su distribución regional es marcadamente discontinua y muy puntual, presentándose allí donde el hábitat le es propicio. Aunque el análisis es preliminar, e

Cordero, P. J.; Llorente, V.; Aparicio, J. M.

2007-01-01

294

Historical development and some emendations of dinoflagellate taxonomy  

Directory of Open Access Journals (Sweden)

Full Text Available The historical development of dinoflagellate taxonomy in China and the world are reviewed, and the taxonomic status of some dinoflagellate groups in Chinese coastal seas are emended. It has been more than 200 years since the discovery of dinoflagellates, but following intensive study, increasing confusion and controversy in dinofalgellate taxonomy has become apparent. In this paper, a broad overview of the history of dinoflagellate taxonomy is presented, highlighting some major developments. Differences exist between the international and Chinese taxonomy system. When comparing the internationally accepted system (based on the information provided by the website algaeBASE) with that used in China (based on the monograph Checklist of Marine Biota of China Seas), we found that they were very similar at the order level, but some differences existed at the family and genus levels. According to morphological and some physiological characteristics, a more reasonable taxonomy is presented. The main emendations are: (1) the three genera named Karenia, Karlodinium and Takayama, are separated from the family Gymnodiniaceae and classified as a new family Kareniaceae; (2) most species in the genus Ceratium are placed in Neoceratium; (3) the genus Alexandrium is separated from family Goniodomataceae, and placed in the family Gonyaulacaceae; (4) the family Heteraulacaceae is replaced by the family Goniodomataceae; and (5) two new orders, Oxyrrhinales and Pyrocystales, are established.

Xin Ma; Ruixiang Li; Yan Li; Yulong Pan

2013-01-01

295

Developing a Taxonomy for Coding Ambulatory Medical Errors: A Report From the ASIPS Collaborative.  

Science.gov (United States)

Multiple taxonomies are used to classify medical errors. Most are conceptually based with limited empirical evidence on their utility to characterize processes leading to errors. We analyzed the utility of the Dimensions of Medical Outcomes taxonomy to de...

W. D. Pace D. H. Fernald D. M. Harris L. M. Dickinson R. Araya-Guerra

2005-01-01

296

Distributions, sources, and ecological risks of DDT-related contaminants in water, suspended particulate matter, and sediments from Haihe Plain, Northern China.  

UK PubMed Central (United Kingdom)

The residual levels of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including p,p'-DDT, DDD, and DDE) in water, suspended particulate matter (SPM), and sediments from major rivers, lakes, and reservoirs in Haihe Plain were measured with a gas chromatograph equipped with a (63)Ni microelectron capture detector. In the fall of 2004, the contents of the total DDXs in the water and SPM were 0.29 ± 0.69 ng L(-1) and 423.13 ± 577.85 ng g(-1) dry wt., respectively. In the spring of 2005, the total DDXs were 0.36 ± 0.91 ng L(-1) for water and 35.93 ± 62.65 ng g(-1) dry wt. for SPM. The average concentration of DDXs for sediments was 7.10 ± 7.57 ng g(-1) dry wt. during the two seasons. The Eastern-Hebei-Province Coastland River System was the most polluted, which was mainly attributable to the extensive use of DDT pesticide and dicofol in that system. Recent DDT inputs still occur in some regions, as indicated by DDT/(DDD + DDE) > 1 at 29-36 % of the sites for water and 55-61 % of the sites for SPM. The potential ecological risks of DDT in the water were assessed using a species sensitivity distribution model. Only shrimp and crabs were found to have potentially affected fraction values of 1.63 × 10(-3) to 2.27 × 10(-4), with probabilities beyond the hazardous concentration for 5 % of species (HC5) values of 1.90-2.56 %, suggesting only slight risks. DDXs in the sediments of some sites were also of potential risk to benthic organism based on consensus-based sediment quality guidelines.

Wang Y; He W; Qin N; He QS; Kong XZ; Tao S; Xu FL

2013-02-01

297

Ecological distribution of Legionella pneumophila  

Energy Technology Data Exchange (ETDEWEB)

Bacteria were concentrated 500-fold from 20-liter water samples collected from 67 different lakes and rivers in the United States. The data suggest that Legionella pneumophila is part of the natural aquatic environment, and that the bacterium is capable of surviving extreme ranges of environmental conditions. The data further demonstrate the effectiveness of the direct fluorescent antibody technique for detecting L. pneumophila in natural aquatic systems. Smears of the concentrated samples were screened microscopically for the serogroups of L. pneumophilia by the direct fluorescent antibody (DFA) technique. Virtually all of the 793 samples were DFA-positive. Those samples (318) containing the largest numbers of DFA positive bacteria which were morphologically consistent with L. pneumophila were injected into guinea pigs for attempted isolations. Isolates were obtained from habitats with a wide range of physical, chemical, and biological parameters. Samples collected monthly from a thermally altered lake demonstrated a seasonality of guinea pig infection, with greatest infection occurring during the summer months.

Fliermans, C B; Cherry, W B; Orrison, L H; Smith, S J; Tison, D L; Pope, D H

1980-01-01

298

Political ecology  

International Nuclear Information System (INIS)

Using facts and examples, this didactically structures textbook gives an insight into the extent and consequences of the damage to the environment, with the subjects - fundamentals of ecology; - population and food problems; - the energy problem; - economic growth; scarcity of resources, recycling; - ground, water, and air pollution, - city and traffic problems; - work protection and medical care; - political alternatives and 'soft technologies'. The analysis of the political and economic reasons is combined with social and technical alternatives from which demands to be made and measures to be taken can be derived for individuals, citizens' interest groups, political groups and trade unions. Teaching models intend to help teachers to work on specific problems of ecology. (orig.)

1979-01-01

299

ECOLOGICAL EDUCATION  

Directory of Open Access Journals (Sweden)

Full Text Available While in most emerging and developing countries, the population has a lower ecological footprint in the developed countries have a larger footprint.There is also an alarming contrast between a person perception of her liability for damages to its environment and its actual size. These misconceptions may have their source in the absence of awareness of risks from climate change, culture or religion.The purpose of this study is to analyze the situation at the international and Romanian level and to draw attention on the necessity of un ecological education.

GABRIELA GYONGY MIHUT

2011-01-01

300

Ecological niche  

Energy Technology Data Exchange (ETDEWEB)

The ecological niche of an organism is the set of environmental conditions under which the particular functions of the organism could be expected to assure its survival. It comprises both the set of conditions where the organism lives (often termed the habitat of the organism) and the functional role of the organism in the ecosystem. Recent works in niche theory have enabled ecologists to develop predictions and actual applications. The history of the niche concept, applications of niche theory, and ecological differences between similar species are discussed.

Shugart, H.H.

1980-01-01

 
 
 
 
301

A taxonomy of control in intensified processes  

International Nuclear Information System (INIS)

Process Intensification (PI) is a revolutionary approach to design, development and implementation of process and plant. PI technology offers improved environment in a chemical process in terms of better products, and processes which are safer, cleaner, smaller - and cheaper. PI is a strategy of making dramatic reductions in the size of unit operations within chemical plants, in order to achieve given production objectives. However, PI technology would be handicapped if such system is not properly controlled. There are some foreseeable problems in order to control such processes for instance, dynamic interaction between components that make up a control loop, response time of the instrumentations, availability of proper sensor and etc. In some cases, in order to control these systems, advanced control solutions have been applied i.e. model predictive controllers (MPC) and its different algorithms such as quadratic generalized predictive control (QGPC) and self tuning quadratic generalized predictive control (STQGPC). Nevertheless in some cases simpler solutions could be applied to control such system for example proportional integral controller in the control of reactive distillation systems. As mentioned, conventional control systems like proportional-integral, proportional-integral-derivative (PID) controllers and their different structures can be used in PI systems but due to inherent nonlinearity and fast responsiveness of PI systems, digital controllers-regarding to their robustness-are mostly applied in order to control PI systems. Regarding to the fact that choosing the appropriate control strategy is the most essential part of making PI systems possible to be handle easily, taxonomy of the usage of various control structure in controlling PI systems is proposed. This paper offers an overview and discussion on identifying potential problems of instrumentation in PI technology and available control strategies

2006-01-01

302

The conceptual validity of a taxonomy of nursing interventions.  

Science.gov (United States)

The purpose of this paper is to report validity evidence for the nursing intervention taxonomy developed as part of the Nursing Intervention Lexicon and Taxonomy (NILT) Study. Using eclectic classification methods of library science, cognitive science, nursing science and computational linguistics, a taxonomy of nursing interventions consisting of seven categories was developed. These categories which incorporate care as a central concept are described and defined, and prototypical examples of each category are presented. Brinberg & McGrath's validity schema provides the framework within which evidence for validity as value, validity as correspondence and validity as generalizability were examined. Comparison of the NILT categories with previously published categorizations of nursing functions and interventions provides strong support for the validity of this classification. Additionally, comparison of the NILT categories with two internationally derived categorizations of nursing functions supports the robustness or generalizability of the NILT classification. PMID:8132925

Grobe, S J; Hughes, L C

1993-12-01

303

The conceptual validity of a taxonomy of nursing interventions.  

UK PubMed Central (United Kingdom)

The purpose of this paper is to report validity evidence for the nursing intervention taxonomy developed as part of the Nursing Intervention Lexicon and Taxonomy (NILT) Study. Using eclectic classification methods of library science, cognitive science, nursing science and computational linguistics, a taxonomy of nursing interventions consisting of seven categories was developed. These categories which incorporate care as a central concept are described and defined, and prototypical examples of each category are presented. Brinberg & McGrath's validity schema provides the framework within which evidence for validity as value, validity as correspondence and validity as generalizability were examined. Comparison of the NILT categories with previously published categorizations of nursing functions and interventions provides strong support for the validity of this classification. Additionally, comparison of the NILT categories with two internationally derived categorizations of nursing functions supports the robustness or generalizability of the NILT classification.

Grobe SJ; Hughes LC

1993-12-01

304

Ecology, Microbial  

Energy Technology Data Exchange (ETDEWEB)

Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

Konopka, Allan

2009-05-15

305

Ecology of gelatious plankton : With emphasis on feeding interactions, distribution pattern and reproduction biology of Mnemiopsis leidyi in the Baltic Sea  

DEFF Research Database (Denmark)

Comb jellies were a relatively obscure group of zooplankton, until Mnemiopsis leidyi invaded the Black Sea in the 1980’s with cascading effects on several ecosystem levels including commercial fisheries. This native to the east coasts of America triggered large public and scientific attention as a result of this invasion and its ecological and economic impacts. In 2005, when M. leidyi was sighted in Northern Europe for the first time, similar consequences were feared. The aim of my PhD project was to understand the potential impact of M. leidyi on the Baltic Sea ecosystem and constrains on its dispersal. Specifically, the project investigated (i) direct and indirect effects of M. leidyi on the Baltic cod population in its most important spawning ground, (ii) factors governing the spatial and temporal distribution of M. leidyi eggs, larvae and adults in the Baltic and, (iii) M. leidyi reproduction and its effect on population development. The approach involved 13 monthly monitoring cruises from high saline Skagerrak to low saline northern Baltic regions, in situ and laboratory controlled reproduction and feeding experiments, molecular analysis for species verification, and statistical modeling. The low feeding rates and passive negative selection of cod eggs in experiments demonstrate that M. leidyi does not pose a direct threat to the Baltic cod population at the environmental conditions characteristic for its spawning ground. Furthermore, the drastically reduced reproduction rates observed under low salinities suggest M. leidyi is not likely to compete with cod recruits prey. Spatial and temporal surveys show highest abundances during October, with a consistent absence of adult and larval M. leidyi in the northern Baltic. Abundances in the Kattegat were 60 times higher than in the central Baltic, suggesting that the M. leidyi population in the central Baltic is dependent on advection from high saline areas. This interpretation is consistent with the low reproduction rates measured and a low fraction of up-growing animals in the central Baltic. While adults were not observed from April to June in high saline areas, M. leidyi larvae were present throughout the year. It remains unclear where M. leidyi overwinters but high saline areas appear to be important in the annual establishment of the population. Laboratory and in situ reproduction experiments confirmed that fecundity is a major contributor to M. leidyi’s invasion success, although salinity is regulating, and possibly restricting, its range expansion in Northern Europe. Maximum reproduction rates are shown to be attained at low food concentrations, helping reconcile the high population densities observed in localized areas despite low food concentrations. An unexpected discovery was that the arctic relict ctenophore Mertensia ovum, thought to be restricted to the northern Baltic, also occurs in the high saline Kattegat/Skagerrak during winter and spring. Interestingly, in the northern Baltic the M. ovum population consists exclusively of larval-sized animals that are actively reproducing and maintaining a self-sustained population. Natural selection can favor early maturation at small size when mortality rates are high, and our results are consistent with this hypothesis. Currently, M. leidyi has established itself permanently in high and intermediate saline areas in Northern Europe. While the ecological impact of M. leidyi in the central Baltic appears to be limited concern, the environment in other European waters should be more favourable to their populations. In these areas, it is suggested that M. leidyi constitutes a potential threat to fisheries through resource competition with fishes

Jaspers, Cornelia

2012-01-01

306

The taxonomy, biogeography and conservation of the myrmecophilous Chrysoritis butterflies (Lepidoptera: Lycaenidae) in South Africa  

Directory of Open Access Journals (Sweden)

Full Text Available The relevance and integration of scientific knowledge to conservation management of the locally popular and highly endemic butterfly genus Chrysoritis are investigated within the research fields of taxonomy and biogeography. The butterfly genus Chrysoritis contains at least 41 species endemic to South Africa. The taxonomy of Chrysoritis has reached a state where revisions could easily result in a plethora of names between “lumping and splitting”. In practice, the state of the taxonomy of these butterflies on species level may alter their conservation priority. The two most species rich species groups in Chrysoritis have different centres of endemism, however, a butterfly atlas becomes a necessity to reveal more about their biogeography. There is an absence of butterfly species lists in many of our National Parks and Nature Reserves. Legislation should facilitate rather than limit the valuable role of the amateur lepidopterist to add distribution records. In turn, the amateur lepidopterists should adapt and make an effort to explore unknown localities, apart from monitoring butterflies at their well-known localities. The red listing of localised butterflies in South Africa, including a number of Chrysoritis species, is in need of an urgent review in the light of the most recent IUCN categories. A species such as Chrysoritis dicksoni should be protected by law - but at its known localities. The scenario that real conservation action is only needed if the last known locality of a butterfly is threatened, should be abolished. A paradigm shift to conserve the metapopulations of the highly endemic Chrysoritis genus and not merely a few of its species as items that appear on lists, seems necessary.

R.F. Terblanche; H. van Hamburg

2003-01-01

307

A taxonomy of multinational ethical and methodological standards for clinical trials of therapeutic interventions.  

UK PubMed Central (United Kingdom)

BACKGROUND: If trials of therapeutic interventions are to serve society's interests, they must be of high methodological quality and must satisfy moral commitments to human subjects. The authors set out to develop a clinical-trials compendium in which standards for the ethical treatment of human subjects are integrated with standards for research methods. METHODS: The authors rank-ordered the world's nations and chose the 31 with >700 active trials as of 24 July 2008. Governmental and other authoritative entities of the 31 countries were searched, and 1004 English-language documents containing ethical and/or methodological standards for clinical trials were identified. The authors extracted standards from 144 of those: 50 designated as 'core', 39 addressing trials of invasive procedures and a 5% sample (N=55) of the remainder. As the integrating framework for the standards we developed a coherent taxonomy encompassing all elements of a trial's stages. FINDINGS: Review of the 144 documents yielded nearly 15?000 discrete standards. After duplicates were removed, 5903 substantive standards remained, distributed in the taxonomy as follows: initiation, 1401 standards, 8 divisions; design, 1869 standards, 16 divisions; conduct, 1473 standards, 8 divisions; analysing and reporting results, 997 standards, four divisions; and post-trial standards, 168 standards, 5 divisions. CONCLUSIONS: The overwhelming number of source documents and standards uncovered in this study was not anticipated beforehand and confirms the extraordinary complexity of the clinical trials enterprise. This taxonomy of multinational ethical and methodological standards may help trialists and overseers improve the quality of clinical trials, particularly given the globalisation of clinical research.

Ashton CM; Wray NP; Jarman AF; Kolman JM; Wenner DM; Brody BA

2011-06-01

308

Building a taxonomy of GI knowledge : using Bloom`s taxonomy to evalute non-professional users` understanding of GI  

DEFF Research Database (Denmark)

This paper reports on and ongoing study concerning non-professional users` understanding of GI. Online access to GI are offered by many public authorities, in order to make the public able to serve them selves online and gain insight in the physical planning and area administration. The aim of this project is to investigate how and how well non-professional users actually understand GI. For that purpose a taxonomy of GI knowledge is built, drawing on Bloom`s taxonomy. The elements of this taxonomy are described after a presentation of the main research question of the study, the applications chosen for the study and the definition of the non-professional user group. Finally considerations are made concerning the difference between this study and a traditional usability study as well as the further implications of the outcome of the study.

Arleth, Mette

2004-01-01

309

Ecology and distribution of Bulinus truncatus in the Middle East; with comments on the effect of some human activities in their relationship to the snail host on the incidence of bilharziasis haematobia in the Middle East and Africa.  

UK PubMed Central (United Kingdom)

The author gives a comprehensive account of the present status of knowledge regarding the ecology and distribution of Bulinus truncatus, the intermediate host of Schistosoma haematobium in the Middle East and North Africa. He discusses in detail the types of habitat favoured by this snail, its life-cycle and seasonal variations in its populations, the effect of ecological factors on its distribution and occurrence, and the relationship between its control and its bionomics, stressing the many aspects of these subjects that require further investigation and suggesting lines for future research.In addition, the author outlines briefly the effect of some human activities (for example, extension of irrigation and agriculture), in their relationship to the snail host, on the incidence of bilharziasis haematobia in the Middle East and Africa. He concludes the paper with a summary of the three basic needs in respect of bilharziasis control: ecological research; prevention of pollution of waters with human excrement; and avoidance of human contact with infective water.

WATSON JM

1958-01-01

310

An empirically-derived taxonomy of interaction primitives for interactive cartography and geovisualization.  

Science.gov (United States)

Proposals to establish a 'science of interaction' have been forwarded from Information Visualization and Visual Analytics, as well as Cartography, Geovisualization, and GIScience. This paper reports on two studies to contribute to this call for an interaction science, with the goal of developing a functional taxonomy of interaction primitives for map-based visualization. A semi-structured interview study first was conducted with 21 expert interactive map users to understand the way in which map-based visualizations currently are employed. The interviews were transcribed and coded to identify statements representative of either the task the user wished to accomplish (i.e., objective primitives) or the interactive functionality included in the visualization to achieve this task (i.e., operator primitives). A card sorting study then was conducted with 15 expert interactive map designers to organize these example statements into logical structures based on their experience translating client requests into interaction designs. Example statements were supplemented with primitive definitions in the literature and were separated into two sorting exercises: objectives and operators. The objective sort suggested five objectives that increase in cognitive sophistication (identify, compare, rank, associate, & delineate), but exhibited a large amount of variation across participants due to consideration of broader user goals (procure, predict, & prescribe) and interaction operands (space-alone, attributes-in-space, & space-in-time; elementary & general). The operator sort suggested five enabling operators (import, export, save, edit, & annotate) and twelve work operators (reexpress, arrange, sequence, resymbolize, overlay, pan, zoom, reproject, search, filter, retrieve, & calculate). This taxonomy offers an empirically-derived and ecologically-valid structure to inform future research and design on interaction. PMID:24051802

Roth, Robert E

2013-12-01

311

An empirically-derived taxonomy of interaction primitives for interactive cartography and geovisualization.  

UK PubMed Central (United Kingdom)

Proposals to establish a 'science of interaction' have been forwarded from Information Visualization and Visual Analytics, as well as Cartography, Geovisualization, and GIScience. This paper reports on two studies to contribute to this call for an interaction science, with the goal of developing a functional taxonomy of interaction primitives for map-based visualization. A semi-structured interview study first was conducted with 21 expert interactive map users to understand the way in which map-based visualizations currently are employed. The interviews were transcribed and coded to identify statements representative of either the task the user wished to accomplish (i.e., objective primitives) or the interactive functionality included in the visualization to achieve this task (i.e., operator primitives). A card sorting study then was conducted with 15 expert interactive map designers to organize these example statements into logical structures based on their experience translating client requests into interaction designs. Example statements were supplemented with primitive definitions in the literature and were separated into two sorting exercises: objectives and operators. The objective sort suggested five objectives that increase in cognitive sophistication (identify, compare, rank, associate, & delineate), but exhibited a large amount of variation across participants due to consideration of broader user goals (procure, predict, & prescribe) and interaction operands (space-alone, attributes-in-space, & space-in-time; elementary & general). The operator sort suggested five enabling operators (import, export, save, edit, & annotate) and twelve work operators (reexpress, arrange, sequence, resymbolize, overlay, pan, zoom, reproject, search, filter, retrieve, & calculate). This taxonomy offers an empirically-derived and ecologically-valid structure to inform future research and design on interaction.

Roth RE

2013-12-01

312

Current and pending taxonomy of the Pasteurellaceae  

DEFF Research Database (Denmark)

Since the family Pasteurellaceae was established in 1981 the taxonomy of this group of bacteria has undergone significant changes. 16S DNA sequencing showed in the early 1990-ties, that the three original genera were genetically heterogeneous. Presently, the family consists of 13 genetically coherent genera with 38 properly classified species. In addition, there are 24 misclassified species that have been excluded from the genera Actinobacillus, Pasteurella and Heamophilus and which probably will be allocated to new genera in the future. At the moment 92 different taxa (named species and provisional taxa) have been described within the family. In the presentation different methods for species delineation will be presented and potential problems discussed in relation to selected examples. It is currently recommended that a new species should be separated from other species by at lest two phenotypic tests. Within genus Mannheimia the separation between M. haemolytica and M. glucosida was based on a polyphasic taxonomic investigation, but there is only one phenotypic character to separate the species and presently no genotypic test. A group of Mannheimia sp. is genetically distinct but lack common phenotypic characters and can consequently not be formally named. Such problems could be solved by establishing genomospecies. Histophilus somni represent a genotypically well defined species but show great phenotypic variability. Here a PCR test based on the rrn-operon was included in the formal species description. [Haemophilus] parasuis show marked variability in the rnn-operons and illustrates that analysis of 16S rDNA sequences can lead to incorrect conclusions in a non-clonal population. The separation between Actinobacillus pleuropneumoniae and A. lignieresii is not possible based on the rrn-operons alone but the existence of two separate species is evident based on AFLP-genotyping. Although 16S sequencing is a versatile tool for taxonomic investigations, its discriminative power for species delineation is in a number of cases limited. DNA-DNA hybridization is still regarded as a golden standard for separating species but the sequencing of housekeeping genes represents a promising alternative. Whole genome sequencing will probably accelerate as less labour intensive methods are developed and prices go down. Data from these genome sequencing projects will make a more detailed study of the genetic affiliation between strains and species feasible. At the same time the genotypic variation within a species and the description of the “pan-genomes” and “core-genomes” will represent a challenge to our conception of what a species is.

Angen, Øystein Technical University of Denmark,

313

Distribution of environmentally sensitive elements in residential soils near a coal-fired power plant: Potential risks to ecology and children's health.  

UK PubMed Central (United Kingdom)

One hundred and twelve soil samples were collected from residential areas surrounding a coal-fired power plant at Huainan City, Anhui Province, China. The concentrations of environmentally sensitive elements (ESEs As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V and Zn) in soil samples were determined, and their potential ecological and health risks were assessed. Mean concentrations of ESEs in the downwind soils of the power plant are relatively higher than those in the upwind soils, pointing to a potential ESEs input from coal combustion. The calculated ecological risk of ESEs in soils indicates a relatively low ecological risk. Hazard quotient (HQ) of ESEs in downwind soils is 1.5, suggesting a potential health risk for children. However, the carcinogenic risk values of ESEs in soils are within the acceptable non-hazardous range of 1E-06-1E-04.

Tang Q; Liu G; Zhou C; Zhang H; Sun R

2013-09-01

314

Fish-based groups for ecological assessment in rivers: the importance of environmental drivers on taxonomic and functional traits of fish assemblages Groupes ichtyologiques pour l'évaluation écologique des rivières : importance des facteurs environnementaux sur la taxonomie et les caractéristiques fonctionnelles des peuplements de poissons  

Directory of Open Access Journals (Sweden)

Full Text Available The use of river-types is of practical value, serving as groups for which assessment procedures can be developed and applied. An abiotic typology was set by the Portuguese Water Agency, mainly based on 6 major morphoclimatic regions. However, to be biologically meaningful, this typology should fit the distribution patterns of the biological quality elements communities proposed in Water Framework Directive under the lowest possible human pressure. This study aimed to identify and characterize fish-based geographical groups for continental Portugal and their environmental and geographical discriptors, using taxonomic and functional traits. Sampling took place between 2004 and 2006 during Spring. Fish fauna from 155 reference sites was analysed using a multivariate approach. Cluster Analysis on fish composition identified 10 fish-groups, expressing a clear correspondence to the river basin level, due to the restrict basin distribution of many species. Groups showed a wider aggregation in 4 regions with a larger geographical correspondence, statistically supported by Similarity Analysis, both on fish composition and mostly on fish metrics/guilds. Principal Components Analysis revealed major environmental drivers associated to fish-groups and fish-regions. Fish-groups were hierarchically grouped over major and local regions, expressing a large-scale response to a North-South environmental gradient defined by temperature, precipitation, mineralization and altitude, and a regional scale response mainly to drainage area and flow discharge. From North to South, fish-regions were related to the morphoclimatic regions. Results contributed to reduce redundance in abiotic river-types and set the final typology for Portuguese rivers, constituting a fundamental tool for planning and managing water resources. L'utilisation de rivière-types est un moyen pratique, fournissant des groupes pour lesquels des procédures d'évaluation peuvent être développées et appliquées. Une typologie abiotique a été fixée par l'Agence de l'Eau Portugaise, principalement basée sur 6 principales régions morphoclimatiques. Toutefois, pour être biologiquement significative, cette typologie devrait correspondre aux schémas de distribution des communautés, éléments de qualité biologique, proposés dans la directive cadre sur l'eau sous la pression anthropique la plus basse possible. Cette étude visait à identifier et à caractériser des groupes géographiques reposant sur les communautés ichtyologiques pour le Portugal continental et leurs descripteurs environnementaux et géographiques, à l'aide de traits taxonomiques et fonctionnels. L'échantillonnage a eu lieu entre 2004 et 2006 au cours du printemps. La faune de poissons provenant de 155 sites de référence a été analysée en utilisant une approche multivariée. L’analyse de clusters sur la composition en poissons a identifié 10 groupes ichtyologiques, exprimant une correspondance claire à l'échelle du bassin versant, en raison de la distribution limitée à un bassin de nombreuses espèces. Les groupes ont montré une plus large agrégation dans 4 régions avec une plus grande correspondance géographique, confirmée statistiquement par l'analyse de similarité, à la fois sur la composition en poisson et surtout sur les métriques ichtyologiques ou les guildes. L’analyse en Composantes Principales a révélé les principaux facteurs environnementaux associés aux groupes et régions ichtyologiques. Les groupes ichtyologiques ont été regroupés hiérarchiquement sur des régions locales et plus grandes, exprimant une réponse à grande échelle à un gradient Nord-Sud de l'environnement défini par la température, les précipitations, la minéralisation et l'altitude, et une réponse à l'échelle régionale principalement à l'aire de drainage et au débit. Du Nord au Sud, les régions ichtyologiques étaient liées aux zones morphoclimatiques. Les résultats contribuent à réduire la redondance dans les types abiotiques de rivières et définissent

Matono P.; Bernardo J.M.; Ferreira M.T.; Formigo N.; Raposo de Almeida P.; Cortes R.; Ilhéu M.

2012-01-01

315

Landscape ecology  

Energy Technology Data Exchange (ETDEWEB)

In this paper the authors outline an approach to landscape study that employs a hierarchical paradigm of pattern and behavior. Although emphasis is on forested landscapes, we can generalize a theory of landscape ecology. Attention is focused on the wide range of phenomena in a natural terrestrial landscape by considering the apparent complexity of landscape dynamics and illustrating how a hierarchical paradigm lends itself to simplifying such complexity. This perspective also affords insights into the management of man-dominated landscapes.

Urban, D.L.; O' Neill, R.V.; Shugart, H.H. Jr.

1987-02-01

316

A Taxonomy for Semi-Supervised Learning Methods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We propose a simple taxonomy of probabilistic graphical models for the semi-supervised learning problem. We give some broad classes of algorithms for each of the families and point to specific realizations in the literature. Finally, we shed more detailed light on the family of methods using input-d...

Chapelle, O.; Schoelkopf, Bernhard; Zien, A.; Seeger, Matthias

317

Applying a Knowledge Management Taxonomy to Secondary Schools  

Science.gov (United States)

|The purpose of this article is to examine the relevance of a corporate-based taxonomy of knowledge management to secondary schooling. Do the principles of knowledge management from the corporate world translate to the world of education; specifically, secondary schooling? This article examines categories of knowledge management articulated in…

Thambi, Melinda; O'Toole, Paddy

2012-01-01

318

Toward a Taxonomy of Self-Assessable Skills.  

Science.gov (United States)

Summarizes the activities the authors undertook to develop a comprehensive taxonomy of transferable skills that would be amenable to self-identification by adults with work experience and that could be related reliably to a wide range of occupations in the labor market. (CT)

Mayall, Donald; Maze, Marilyn

1985-01-01

319

Teaching Introductory Organic Chemistry: 'Blooming' beyond a Simple Taxonomy.  

Science.gov (United States)

Suggests that most students approach organic chemistry classes with a certain amount of apprehension and try to just manage or memorize the material rather than understand it. Recommends the use of Bloom's taxonomy as a way to increase comprehension and gives an example of how to use it in an organic chemistry classroom. (SOE)

Pungente, Michael D.; Badger, Rodney A.

2003-01-01

320

New Augmented Reality Taxonomy: Technologies and Features of Augmented Environment.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article has a dual aim: firstly to define augmented reality (AR) en- vironments and secondly, based on our definition, a new taxonomy enabling these environments to be classified. After briefly reviewing existing classifica- tions, we define AR by its purpose, ie. to enable someone to create se...

Hugues, Olivier; Fuchs, Philippe; Nannipieri, Olivier

 
 
 
 
321

PHYSIOLOGY OF THE ENTEROCOCCI AS RELATED TO THEIR TAXONOMY1  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.), Donald E. Lake, and C. F. Niven, Jr. Physiology of the enterococci as related to their taxonomy. J. Bacteriol. 86:1275–1282. 1963—Studies on a collection of enterococci isolated from diverse sources have confirmed the existence of tw...

Deibel, R. H.; Lake, Donald E.; Niven, C. F.

322

Using Bloom's Taxonomy to Teach Students about Plagiarism  

Science.gov (United States)

Melissa A. Vosen outlines a unit she has designed to help students comprehend the often unclear boundaries and issues surrounding plagiarism. Using Bloom's taxonomy of the cognitive domain, students complete increasingly complex tasks, learning to construct a works cited page and assess scholarly opinions. They also research the consequences of…

Vosen, Melissa A.

2008-01-01

323

Measuring the Impact of Haptic Feedback Using the SOLO Taxonomy  

Science.gov (United States)

The application of Biggs' and Collis' Structure of Observed Learning Outcomes taxonomy in the evaluation of student learning about cell membrane transport via a computer-based learning environment is described in this study. Pre-test-post-test comparisons of student outcome data (n = 80) were made across two groups of randomly assigned students:…

Minogue, James; Jones, Gail

2009-01-01

324

Taxonomy becoming a driving force in genome sequencing projects.  

UK PubMed Central (United Kingdom)

We studied the possible impact of genomic projects by comparing the number of published articles before and after the completion of the project. We found that for most species, there is no significant change in the number of citations. Also our study remarks the growing importance of taxonomy as main motivation for the sequencing of genomes.

Tamames J; Durante-Rodríguez G

2013-06-01

325

Merlin C. Wittrock and the Revision of Bloom's Taxonomy  

Science.gov (United States)

|Merl Wittrock, a cognitive psychologist who had proposed a generative model of learning, was an essential member of the group that over a period of 5 years revised the "Taxonomy of Educational Objectives," originally published in 1956. This article describes the development of that 2001 revision (Anderson and Krathwohl, Editors) and Merl's…

Krathwohl, David R.; Anderson, Lorin W.

2010-01-01

326

Solutions to Penicillium taxonomy crucial to mycotoxin research and health.  

Science.gov (United States)

The stability of taxonomy within Penicillium is reviewed with respect to mycotoxin production. Identification remains difficult despite the availability of modern methods. Proficiency testing is rare and conventional identifications do not inform reliably as to whether mycotoxins were detected/produced. A solution which consists of identifying a Penicillium strain as terverticillate and then undertaking mycotoxin analysis is described. PMID:15313249

Paterson, R Russell M; Venâncio, Armando; Lima, Nelson

2004-09-01

327

Solutions to Penicillium taxonomy crucial to mycotoxin research and health.  

UK PubMed Central (United Kingdom)

The stability of taxonomy within Penicillium is reviewed with respect to mycotoxin production. Identification remains difficult despite the availability of modern methods. Proficiency testing is rare and conventional identifications do not inform reliably as to whether mycotoxins were detected/produced. A solution which consists of identifying a Penicillium strain as terverticillate and then undertaking mycotoxin analysis is described.

Paterson RR; Venâncio A; Lima N

2004-09-01

328

Molecular phylogenetics reveals extreme morphological homoplasy in Brazilian worm lizards challenging current taxonomy.  

UK PubMed Central (United Kingdom)

Amphisbaenians are fossorial squamate reptiles distributed mainly in South America and Africa. Brazilian worm lizards belong to the family Amphisbaenidae, which has far more recognized species than any of the other five amphisbaenian families. Morphological datasets recovered Amphisbaenidae as paraphyletic, while previous molecular phylogenetic studies did not include enough taxa to solve the generic-level relationships within this family. We present a molecular phylogenetic hypothesis based on a sample of 58 amphisbaenians, including representatives of six of the seven South American genera. Our molecular data include sequences from two mitochondrial genes (16S, ND2; 1,184 characters) and three nuclear genes (RAG-1, C-MOS, BDNF; 1,898 characters). Our phylogenetic hypothesis is not fully resolved, although it does not support the monophyly of most genera except Leposternon. Morphological characters currently used to diagnose genera of South American amphisbaenians are homoplastic, and the taxonomy based on them is not appropriate. We revise the taxonomy of this group and sink several South American genera of Amphisbaenidae (Cercolophia, Bronia, Aulura, Anops and Leposternon) into Amphisbaena.

Mott T; Vieites DR

2009-05-01

329

Advances in molecular identification, taxonomy, genetic variation and diagnosis of Toxocara spp.  

UK PubMed Central (United Kingdom)

The genus Toxocara contains parasitic nematodes of human and animal health significance, such as Toxocara canis, Toxocara cati and Toxocara vitulorum. T. canis and T. cati are among the most prevalent parasites of dogs and cats with a worldwide distribution. Human infection with T. canis and T. cati, which can cause a number of clinical manifestations such as visceral larva migrans (VLMs), ocular larva migrans (OLMs), eosinophilic meningoencephalitis (EME), covert toxocariasis (CT) and neurotoxocariasis, is considered the most prevalent neglected helminthiasis in industrialized countries. The accurate identification Toxocara spp. and their unequivocal differentiation from each other and from other ascaridoid nematodes causing VLMs and OLMs has important implications for studying their taxonomy, epidemiology, population genetics, diagnosis and control. Due to the limitations of traditional (morphological) approaches for identification and diagnosis of Toxocara spp., PCR-based techniques utilizing a range of genetic markers in the nuclear and mitochondrial genomes have been developed as useful alternative approaches because of their high sensitivity, specificity, rapidity and utility. In this article, we summarize the current state of knowledge and advances in molecular identification, taxonomy, genetic variation and diagnosis of Toxocara spp. with prospects for further studies.

Chen J; Zhou DH; Nisbet AJ; Xu MJ; Huang SY; Li MW; Wang CR; Zhu XQ

2012-10-01

330

Advances in molecular identification, taxonomy, genetic variation and diagnosis of Toxocara spp.  

Science.gov (United States)

The genus Toxocara contains parasitic nematodes of human and animal health significance, such as Toxocara canis, Toxocara cati and Toxocara vitulorum. T. canis and T. cati are among the most prevalent parasites of dogs and cats with a worldwide distribution. Human infection with T. canis and T. cati, which can cause a number of clinical manifestations such as visceral larva migrans (VLMs), ocular larva migrans (OLMs), eosinophilic meningoencephalitis (EME), covert toxocariasis (CT) and neurotoxocariasis, is considered the most prevalent neglected helminthiasis in industrialized countries. The accurate identification Toxocara spp. and their unequivocal differentiation from each other and from other ascaridoid nematodes causing VLMs and OLMs has important implications for studying their taxonomy, epidemiology, population genetics, diagnosis and control. Due to the limitations of traditional (morphological) approaches for identification and diagnosis of Toxocara spp., PCR-based techniques utilizing a range of genetic markers in the nuclear and mitochondrial genomes have been developed as useful alternative approaches because of their high sensitivity, specificity, rapidity and utility. In this article, we summarize the current state of knowledge and advances in molecular identification, taxonomy, genetic variation and diagnosis of Toxocara spp. with prospects for further studies. PMID:22569289

Chen, Jia; Zhou, Dong-Hui; Nisbet, Alasdair J; Xu, Min-Jun; Huang, Si-Yang; Li, Ming-Wei; Wang, Chun-Ren; Zhu, Xing-Quan

2012-04-28

331

THE INFLUENCE OF SEASONAL DISTRIBUTION PATTERNS, ECOLOGICAL PREFERENCES AND CALCIFICATION PROCESSES ON THE INCORPORATION OF STABLE OXYGEN AND CARBON ISOTOPES IN PLANKTIC FORAMINIFERAL CALCITE SHELLS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The presented thesis contributes to a better knowledge of planktic foraminiferal ecology as a prerequisite to understand the incorporation of stable carbon and oxygen isotopes into their calcite shells. This in turn provides the opportunity of improved proxy development and/or proxy calibration. The...

Wilke, Iris

332

Advances and trends in the molecular systematics of anisakid nematodes, with implications for their evolutionary ecology and host-parasite co-evolutionary processes.  

Science.gov (United States)

The application of molecular systematics to the anisakid nematodes of the genera Anisakis, Pseudoterranova and Contracaecum, parasites of aquatic organisms, over the last two decades, has advanced the understanding of their systematics, taxonomy, ecology and phylogeny substantially. Here the results of this effort on this group of species from the early genetic works to the current status of their revised taxonomy, ecology and evolutionary aspects are reviewed for each of three parasitic groups. It has been shown that many anisakid morphospecies of Anisakis, Contracaecum and Pseudoterranova include a certain number of sibling species. Molecular genetic markers provided a rapid, precise means to screen and identify several species that serve as definitive and intermediate and or/paratenic hosts of the so far genetically characterized species. Patterns of differential distribution of anisakid nematodes in various definitive and intermediate hosts are presented. Differences in the life history of related species can be due both to differential host-parasite co-adaptation and co-evolution, and/or to interspecific competition, that can reduce the range of potential hosts in sympatric conditions. Phylogenetic hypotheses attempted for anisakid nematodes and the possible evolutionary scenarios that have been proposed inferred from molecular data, also with respect to the phylogeny of their hosts are presented for the parasite-host associations Anisakis-cetaceans and Contracaecum-pinnipeds, showing that codivergence and host-switching events could have accompanied the evolution of these groups of parasites. Finally, examples in which anisakid nematodes recognized genetically at the species level in definitive and intermediate/paratenic hosts from various geographical areas of the Boreal and Austral regions and their infection levels have been used as biological indicators of fish stocks and food-web integrity in areas at high versus low levels of habitat disturbance (pollution, overfishing, by-catch) are presented. PMID:18486689

Mattiucci, Simonetta; Nascetti, Giuseppe

2008-01-01

333

US ecology data system  

International Nuclear Information System (INIS)

The US Ecology computer data system was instituted March 1, 1982. This system was designed to manage the increasing flow of paperwork and data associated with the receipt and disposal of low-level radioactive waste at Richland, Washington and Beatty, Nevada. The system was modified and upgraded in 1984 to accommodate a revised shipping manifest pursuant to the requirements of 10 CFR 20.311. The data system is used to generate various reports for both internal and external distribution. The computer system is located at US Ecology's corporate headquarters in Louisville, Kentucky. Remote access terminals are located at the disposal sites. The system is supported by a Wang VS-100 processor. In addition to supporting the radwaste data system, the system supports a chemical waste data base, word processing, and electronic mail. The management and operation of this data base are described. 19 figures.

1987-01-01

334

A Note on Extending Taylor's Power Law for Characterizing Human Microbial Communities: Inspiration from Comparative Studies on the Distribution Patterns of Insects and Galaxies, and as a Case Study for Medical Ecology  

CERN Multimedia

Many natural patterns, such as the distributions of blood particles in a blood sample, proteins on cell surfaces, biological populations in their habitat, galaxies in the universe, the sequence of human genes, and the fitness in evolutionary computing, have been found to follow power law. Taylor's power law (Taylor 1961: Nature, 189:732-) is well recognized as one of the fundamental models in population ecology. A fundamental property of biological populations, which Taylor's power law reveals, is the near universal heterogeneity of population abundance distribution in habitat. Obviously, the heterogeneity also exists at the community level, where not only the distributions of population abundances but also the proportions of the species composition in the community are often heterogeneous. Nevertheless, existing community diversity indexes such as Shannon index and Simpson index can only measure "local" or "static" diversity in the sense that they are computed for each habitat at a specific time point, and t...

Ma, Zhanshan Sam

2012-01-01

335

TAXONOMY FOR WSN SECURITY-A SURVEY  

Directory of Open Access Journals (Sweden)

Full Text Available WSN is one of the dominant and emerging technology that shows great promise for  various application in military, ecological and health related areas.WSN is highly vulnerable to attacks and inclusion of wireless communication technology incurs various types of security threats.WSN requires security measures due to sensitive data and as sensor may operate in hostile unattended environment.WSN suffer from constraints like low computational capability, small memory limited energy resources physical capture susceptibility and insecure wireless communication channel. These create security a challenge in WSN. In this article we provide a survey of security in WSN.We provide an outline with constraints and security requirement and attacks with their counter measures in WSN.

kshitija Ajabrao chaple

2013-01-01

336

Phylogeny and taxonomy of the genus Gliocladiopsis.  

UK PubMed Central (United Kingdom)

Using a global set of isolates and a phylogenetic approach employing DNA sequence data from five genes (?-tubulin, histone H3, internal transcribed spacer region, 28S large subunit region and translation elongation factor 1-?), the taxonomic status of the genus Gliocladiopsis (Glionectria) (Hypocreales, Nectriaceae) was re-evaluated. Gliocladiopsis sagariensis is reinstated as type species for the genus, which proved to be distinct from its former synonym, G. tenuis. The purported teleomorph state of G. tenuis, Glionectria tenuis, is shown to be distinct based on morphological comparisons supported by phylogenetic inference, and is provided with a new name, Gliocladiopsis pseudotenuis. A further four species, mostly isolated from soil, are newly described, namely G. curvata (New Zealand, Ecuador and Indonesia), G. elghollii (USA), G. indonesiensis (Indonesia) and G. mexicana (Mexico). Although species of Gliocladiopsis are frequently isolated from roots of diseased plants or plant litter in soil, little is presently known of their ecology, or potential role as plant pathogens.

Lombard L; Crous PW

2012-06-01

337

Compilation of morphological and molecular data, a necessity for taxonomy: The case of Hormogaster abbatissae sp. n. (Annelida, Clitellata, Hormogastridae)  

Directory of Open Access Journals (Sweden)

Full Text Available Conflict among data sources can be frequent in evolutionary biology, especially in cases where one character set poses limitations to resolution. Earthworm taxonomy, for example, remains a challenge because of the limited number of morphological characters taxonomically valuable. An explanation to this may be morphological convergence due to adaptation to a homogeneous habitat, resulting in high degrees of homoplasy. This sometimes impedes clear morphological diagnosis of species. Combination of morphology with molecular techniques has recently aided taxonomy in many groups difficult to delimit morphologically. Here we apply an integrative approach by combining morphological and molecular data, including also some ecological features, to describe a new earthworm species in the family Hormogastridae, Hormogaster abbatissae sp. n., collected in Sant Joan de les Abadesses (Girona, Spain). Its anatomical and morphological characters are discussed in relation to the most similar Hormogastridae species, which are not the closest species in a phylogenetic analysis of molecular data. Species delimitation using the GMYC method and genetic divergences with the closest species are also considered. The information supplied by the morphological and molecular sources is contradictory, and thus we discuss issues with species delimitation in other similar situations. Decisions should be based on a profound knowledge of the morphology of the studied group but results from molecular analyses should also be considered.

Marta Novo; Rosa Fernández; Daniel Fernández Marchán; Mónica Gutiérrez; Dario Diaz Cosin

2012-01-01

338

Compilation of morphological and molecular data, a necessity for taxonomy: The case of Hormogaster abbatissae sp. n. (Annelida, Clitellata, Hormogastridae).  

UK PubMed Central (United Kingdom)

Conflict among data sources can be frequent in evolutionary biology, especially in cases where one character set poses limitations to resolution. Earthworm taxonomy, for example, remains a challenge because of the limited number of morphological characters taxonomically valuable. An explanation to this may be morphological convergence due to adaptation to a homogeneous habitat, resulting in high degrees of homoplasy. This sometimes impedes clear morphological diagnosis of species. Combination of morphology with molecular techniques has recently aided taxonomy in many groups difficult to delimit morphologically. Here we apply an integrative approach by combining morphological and molecular data, including also some ecological features, to describe a new earthworm species in the family Hormogastridae, Hormogaster abbatissaesp. n., collected in Sant Joan de les Abadesses (Girona, Spain). Its anatomical and morphological characters are discussed in relation to the most similar Hormogastridae species, which are not the closest species in a phylogenetic analysis of molecular data. Species delimitation using the GMYC method and genetic divergences with the closest species are also considered. The information supplied by the morphological and molecular sources is contradictory, and thus we discuss issues with species delimitation in other similar situations. Decisions should be based on a profound knowledge of the morphology of the studied group but results from molecular analyses should also be considered.

Novo M; Fernández R; Marchán DF; Mónica Gutiérrez; Cosín DJ

2012-01-01

339

Patterns of Genitalic Morphology Around Suture Zones in North American Lycaeides (Lepidoptera: Lycaenidae): Implications for Taxonomy and Historical Biogeography  

UK PubMed Central (United Kingdom)

Within the North American Lycaeides (Hübner) fauna, there are at least three major lineages that exhibit extensive morphological and ecological variation, especially at suture zones where these lineages meet. We examined male genitalic morphology in Lycaeides populations spanning much of North America to evaluate the current taxonomy and to address questions about the patterns of morphological variation at suture zones and potential evolutionary processes responsible for the patterns. Our genitalic measurements were based on those of V. Nabokov who revised North American Lycaeides taxonomy in the 1940s. Canonical discriminant analysis validated Nabokov's original species designations, but it did not support many of his subspecific designations. Populations at a suture zone in the Great Lakes region are similar to populations on the east side of this zone. Populations at a western suture zone in the Sierra Nevada and adjacent ranges exhibit intermediate morphology between lineages on either side of this suture zone. We tested the hypothesis that contemporary gene flow contributes to the patterns of morphology in suture zones by testing for the increased variance in quantitative traits that is expected in a hybrid swarm. Based on a comparison of variances from populations within and outside of these suture zones, there is no evidence of current hybridization between lineages, with the sole exception of the population sample from the White Mountains of eastern California. The intermediate morphology and the general absence of increased variance within western suture zone populations imply that hybridization may have been important in the evolution of North American Lycaeides.

Lucas LK; Fordyce JA; Nice CC

2008-01-01

340

Migration Ecology  

Science.gov (United States)

This site from the University of Lund, Sweden, introduces various research studies in the field of Migration Ecology including research information on "Orientation and navigation," "Flight," "Migration patterns," and "Energetics." The mission of the group is "to forward, by research and teaching, the understanding of adaptive values and evolutionary possibilities and limitations in animal migration, -flight, -orientation and energetics." Many of the group's publications are available for free as PDFs, and the site offers a simple search mechanism to help visitors find the publications they are seeking.

Alerstam, Thomas

2008-01-15

 
 
 
 
341

Predicting the distribution of a parasite using the ecological niche model, GARP Predicción de la distribución de un parásito usando el modelo de nicho ecológico, GARP  

Directory of Open Access Journals (Sweden)

Full Text Available The ecological niche of a parasite exists only at the nexus of certain abiotic and biotic conditions suitable for both the definitive and intermediate hosts. However, the life cycles of most parasites are not known, or are poorly known, and using known ranges of hosts to find endemic parasitic infections has been difficult. However, with ecological niche modeling, we can create potential range maps using known localities of infection. Testing the validity of such maps requires knowledge of the localities of other parasites with common history. Here, we find that the ecological niche of a tapeworm parasite of voles, Paranoplocephala macrocephala (Cestoda: Anoplocephalidae), allows prediction of the presence (in ecological and geographic space) of 19 related parasite species from 3 genera in 23 different hosts throughout the Nearctic. These results give credence to the idea that this group shares similar life cycle requirements despite phylogenetic distance. This work further validates ecological niche modeling as a means by which to predict occurrence of parasites when not all facets of the life cycle are confirmed. Such inductive methods create the opportunity for deducing potential reservoir or intermediate hosts, and complementing studies of parasite biodiversity and community ecology.El nicho ecológico de un parásito existe sólo cuando coinciden condiciones abióticas y bióticas necesarias para los hospederos definitivos e intermediarios. No obstante, los ciclos de vida de la mayoría de los parásitos son poco conocidos; el usar áreas de distribución de hospederos para encontrar áreas endémicas de parasitismo ha resultado difícil. Con el modelado de nicho, se pueden producir mapas del área de distribución potencial con base en sitios conocidos de presencia. Para probar la validez de estos mapas, se requiere el conocimiento de sitios de presencia de otros parásitos relacionados. En este estudio, encontramos que el nicho ecológico de un gusano parásito de ratones, Paranoplocephala macrocephala (Cestoda: Anoplocephalidae) permite predecir la presencia de 19 especies relacionadas de parásitos de 3 géneros en 23 diferentes hospederos a través del Neártico. Estos resultados apoyan la idea de que este grupo comparte una historia filogenética común que se refleja en nichos compartidos y que el modelado de nichos ofrece una manera de predecir la presencia de parásitos aunque no se conozcan todos los detalles de su ciclo de vida. Estos métodos permiten deducir reservorios u hospederos para estos parásitos.

Terry R. Haverkost; Scott L. Gardner; A. Townsend Peterson

2010-01-01

342

Predicting the distribution of a parasite using the ecological niche model, GARP/ Predicción de la distribución de un parásito usando el modelo de nicho ecológico, GARP  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El nicho ecológico de un parásito existe sólo cuando coinciden condiciones abióticas y bióticas necesarias para los hospederos definitivos e intermediarios. No obstante, los ciclos de vida de la mayoría de los parásitos son poco conocidos; el usar áreas de distribución de hospederos para encontrar áreas endémicas de parasitismo ha resultado difícil. Con el modelado de nicho, se pueden producir mapas del área de distribución potencial con base en sitios conoc (more) idos de presencia. Para probar la validez de estos mapas, se requiere el conocimiento de sitios de presencia de otros parásitos relacionados. En este estudio, encontramos que el nicho ecológico de un gusano parásito de ratones, Paranoplocephala macrocephala (Cestoda: Anoplocephalidae) permite predecir la presencia de 19 especies relacionadas de parásitos de 3 géneros en 23 diferentes hospederos a través del Neártico. Estos resultados apoyan la idea de que este grupo comparte una historia filogenética común que se refleja en nichos compartidos y que el modelado de nichos ofrece una manera de predecir la presencia de parásitos aunque no se conozcan todos los detalles de su ciclo de vida. Estos métodos permiten deducir reservorios u hospederos para estos parásitos. Abstract in english The ecological niche of a parasite exists only at the nexus of certain abiotic and biotic conditions suitable for both the definitive and intermediate hosts. However, the life cycles of most parasites are not known, or are poorly known, and using known ranges of hosts to find endemic parasitic infections has been difficult. However, with ecological niche modeling, we can create potential range maps using known localities of infection. Testing the validity of such maps req (more) uires knowledge of the localities of other parasites with common history. Here, we find that the ecological niche of a tapeworm parasite of voles, Paranoplocephala macrocephala (Cestoda: Anoplocephalidae), allows prediction of the presence (in ecological and geographic space) of 19 related parasite species from 3 genera in 23 different hosts throughout the Nearctic. These results give credence to the idea that this group shares similar life cycle requirements despite phylogenetic distance. This work further validates ecological niche modeling as a means by which to predict occurrence of parasites when not all facets of the life cycle are confirmed. Such inductive methods create the opportunity for deducing potential reservoir or intermediate hosts, and complementing studies of parasite biodiversity and community ecology.

Haverkost, Terry R.; Gardner, Scott L.; Townsend Peterson, A.

2010-12-01

343

An evolutionary perspective on morphological and ecological characters in the mushroom family Inocybaceae (Agaricomycotina, Fungi).  

UK PubMed Central (United Kingdom)

Inocybaceae is one of the larger families among the gilled mushrooms (Agaricales) but their morphology-based taxonomy is still not fully settled considering molecular-based phylogenetic insights. Here we investigate the evolution of five morphological and four ecological characters using ancestral state reconstruction methods. All the morphological characters are correlated with the phylogeny, but we find spore shape and presence of cortina, to have the greatest taxonomic potential, as they are the most evolutionarily conserved. None of the five characters have, however, evolved in a way that easily delimits inclusive monophyletic groups and the section level taxonomy needs revision. Host preference, preference for calcareous soil, and soil nutritional status preference are shown to be reflective of the evolutionary history of the species at the scale investigated here while soil moisture preference is not. The states of three of the four ecological characters can therefore be predicted in a phylogenetic framework for species where they are unknown.

Ryberg M; Larsson E; Jacobsson S

2010-05-01

344

Ecological Impacts of the Cerro Grande Fire: Predicting Elk Movement and Distribution Patterns in Response to Vegetative Recovery through Simulation Modeling October 2005  

Energy Technology Data Exchange (ETDEWEB)

In May 2000, the Cerro Grande Fire burned approximately 17,200 ha in north-central New Mexico as the result of an escaped prescribed burn initiated by Bandelier National Monument. The interaction of large-scale fires, vegetation, and elk is an important management issue, but few studies have addressed the ecological implications of vegetative succession and landscape heterogeneity on ungulate populations following large-scale disturbance events. Primary objectives of this research were to identify elk movement pathways on local and landscape scales, to determine environmental factors that influence elk movement, and to evaluate movement and distribution patterns in relation to spatial and temporal aspects of the Cerro Grande Fire. Data collection and assimilation reflect the collaborative efforts of National Park Service, U.S. Forest Service, and Department of Energy (Los Alamos National Laboratory) personnel. Geographic positioning system (GPS) collars were used to track 54 elk over a period of 3+ years and locational data were incorporated into a multi-layered geographic information system (GIS) for analysis. Preliminary tests of GPS collar accuracy indicated a strong effect of 2D fixes on position acquisition rates (PARs) depending on time of day and season of year. Slope, aspect, elevation, and land cover type affected dilution of precision (DOP) values for both 2D and 3D fixes, although significant relationships varied from positive to negative making it difficult to delineate the mechanism behind significant responses. Two-dimensional fixes accounted for 34% of all successfully acquired locations and may affect results in which those data were used. Overall position acquisition rate was 93.3% and mean DOP values were consistently in the range of 4.0 to 6.0 leading to the conclusion collar accuracy was acceptable for modeling purposes. SAVANNA, a spatially explicit, process-oriented ecosystem model, was used to simulate successional dynamics. Inputs to the SAVANNA included a land cover map, long-term weather data, soil maps, and a digital elevation model. Parameterization and calibration were conducted using field plots. Model predictions of herbaceous biomass production and weather were consistent with available data and spatial interpolations of snow were considered reasonable for this study. Dynamic outputs generated by SAVANNA were integrated with static variables, movement rules, and parameters developed for the individual-based model through the application of a habitat suitability index. Model validation indicated reasonable model fit when compared to an independent test set. The finished model was applied to 2 realistic management scenarios for the Jemez Mountains and management implications were discussed. Ongoing validation of the individual-based model presented in this dissertation provides an adaptive management tool that integrates interdisciplinary experience and scientific information, which allows users to make predictions about the impact of alternative management policies.

S.P. Rupp

2005-10-01

345

The Twelve Soil Orders - Soil Taxonomy  

Science.gov (United States)

This University of Idaho website discusses the twelve orders of soils, and provides images that illustrate the distribution, properties, and use of the soil orders. It provides general information on each of the twelve orders with a description, a U.S. map showing soil locations, and pictures of the soil type. A Global Distribution Map indicates locations of each soil type throughout the world.

346

Distribuição espacial da leptospirose no Rio Grande do Sul, Brasil: recuperando a ecologia dos estudos ecológicos Spatial distribution of leptospirosis in Rio Grande do Sul, Brazil: recovering the ecology of ecological studies  

Directory of Open Access Journals (Sweden)

Full Text Available A leptospirose apresenta no Estado do Rio Grande do Sul uma grande diversidade de situações de exposição, reservatórios, agentes etiológicos e quadros clínicos. O principal objetivo desse trabalho é identificar áreas de maior risco e possíveis componentes ecológicos da transmissão da leptospirose por meio da agregação de dados epidemiológicos em unidades espaciais que representem a diversidade sócio-ambiental do Estado. Os 1.274 casos confirmados de leptospirose ocorridos em 2001 foram georreferenciados por município de residência. Os mapas de municípios foram sobrepostos aos de caracterização de uso do solo, relevo e bacias hidrográficas. Com as operações de SIG, foram calculadas as taxas de incidência para cada categoria e sua significância estatística. As maiores taxas de incidência foram verificadas em áreas sedimentares litorâneas, de baixa altitude e uso do solo predominantemente agrícola. Nessas áreas, a maior parte dos casos está associada à lavoura irrigada. Os resultados sugerem a existência de características ecológicas favoráveis à transmissão da leptospirose em locais de proliferação de roedores sinantrópicos e de produção agrícola intensiva. São discutidos os efeitos da agregação de dados em unidades ambientais na análise de dados epidemiológicos e estratégias de controle da endemia no Estado.Leptospirosis is an endemic disease in the State of Rio Grande do Sul, Brazil, and presents a broad diversity of exposure routes, reservoirs, etiological agents, and clinical features. The main objective of this work is to identify transmission areas and possible ecological components of leptospirosis transmission. This was accomplished through the aggregation of epidemiological data into spatial units that represent the State's socio-environmental diversity. The 1,274 confirmed leptospirosis cases that occurred in 2001 were georeferenced in the counties of residence. The county maps were overlaid on environmental units characterizing land use, altitude, and river basins. Incidence rates for each environmental class were calculated, along with their statistical significance, through GIS aggregation operations. The highest incidence rates were verified in coastal sedimentary areas with low altitude and predominantly agricultural land use. In these areas, most of the cases were associated with irrigated farming. The results suggest the existence of favorable ecological characteristics for leptospirosis transmission in places involving proliferation of peri-domiciliary rodents and intensive agricultural production. The article discusses the effects of data aggregation into environmental units, as well as strategies to control the endemic in the State.

Christovam Barcellos; Célia Beatriz Lammerhirt; Marco Antonio B. de Almeida; Edmilson dos Santos

2003-01-01

347

Distribuição espacial da leptospirose no Rio Grande do Sul, Brasil: recuperando a ecologia dos estudos ecológicos/ Spatial distribution of leptospirosis in Rio Grande do Sul, Brazil: recovering the ecology of ecological studies  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A leptospirose apresenta no Estado do Rio Grande do Sul uma grande diversidade de situações de exposição, reservatórios, agentes etiológicos e quadros clínicos. O principal objetivo desse trabalho é identificar áreas de maior risco e possíveis componentes ecológicos da transmissão da leptospirose por meio da agregação de dados epidemiológicos em unidades espaciais que representem a diversidade sócio-ambiental do Estado. Os 1.274 casos confirmados de leptos (more) pirose ocorridos em 2001 foram georreferenciados por município de residência. Os mapas de municípios foram sobrepostos aos de caracterização de uso do solo, relevo e bacias hidrográficas. Com as operações de SIG, foram calculadas as taxas de incidência para cada categoria e sua significância estatística. As maiores taxas de incidência foram verificadas em áreas sedimentares litorâneas, de baixa altitude e uso do solo predominantemente agrícola. Nessas áreas, a maior parte dos casos está associada à lavoura irrigada. Os resultados sugerem a existência de características ecológicas favoráveis à transmissão da leptospirose em locais de proliferação de roedores sinantrópicos e de produção agrícola intensiva. São discutidos os efeitos da agregação de dados em unidades ambientais na análise de dados epidemiológicos e estratégias de controle da endemia no Estado. Abstract in english Leptospirosis is an endemic disease in the State of Rio Grande do Sul, Brazil, and presents a broad diversity of exposure routes, reservoirs, etiological agents, and clinical features. The main objective of this work is to identify transmission areas and possible ecological components of leptospirosis transmission. This was accomplished through the aggregation of epidemiological data into spatial units that represent the State's socio-environmental diversity. The 1,274 co (more) nfirmed leptospirosis cases that occurred in 2001 were georeferenced in the counties of residence. The county maps were overlaid on environmental units characterizing land use, altitude, and river basins. Incidence rates for each environmental class were calculated, along with their statistical significance, through GIS aggregation operations. The highest incidence rates were verified in coastal sedimentary areas with low altitude and predominantly agricultural land use. In these areas, most of the cases were associated with irrigated farming. The results suggest the existence of favorable ecological characteristics for leptospirosis transmission in places involving proliferation of peri-domiciliary rodents and intensive agricultural production. The article discusses the effects of data aggregation into environmental units, as well as strategies to control the endemic in the State.

Barcellos, Christovam; Lammerhirt, Célia Beatriz; Almeida, Marco Antonio B. de; Santos, Edmilson dos

2003-10-01

348

Ecological Status and Change by Remote Sensing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Evaluating ecological patterns and processes is crucial for the conservation of ecosystems [1]. In this view, remote sensing is a powerful tool for monitoring their status and change. This involves several tasks like biodiversity estimate, landscape ecology, and species distribution modeling, to nam...

Duccio Rocchini

349

Ecological stability of landscape - ecological infrastructure - ecological management  

International Nuclear Information System (INIS)

[en] The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

1992-01-01

350

The New Ecology  

Science.gov (United States)

Describes new techniques and approaches to ecology, including the systems approach, behavioral studies, the use of of radioistopes to investigate ecological cycles and energetics, and evolutionary ecology, all leading to a more sophisticated understanding of complex natural systems. (EB)

Bioscience, 1970

1970-01-01

351

Evolutionary Ecology Research ???????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Evolutionary Ecology Research is a professional scientific journal focusing on the overlap between ecology and evolution. In 2002, the journal expanded its coverage of macroecology and macroevolution. It has not reduced its attention to the other areas of evolutionary ecology. ?????????...

352

Advances in Ecological Research ??????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Advances in Ecological Research presents a wide range of papers on all aspects of ecology. Topics include the physiology, populations, and communities of plants and animals, as well as landscape and ecosystem ecology. ?????Elsevier???????????????????????????????

353

Evaluating the bases of supplier segmentation : A review and taxonomy  

DEFF Research Database (Denmark)

A taxonomy of segmentation bases is presented which builds a multi-disciplinary approach to the categorization of suppliers. Supplier segmentation, from a purchasing perspective, still appears to be in the early stages of providing a coherent strategic intent behind supplier assessment. Whilst fragmentary in nature, current portfolio models are grouped into two principal taxonomic constructs of power and dependence and relational factors. In particular, the prevalent use of transaction cost economics (TCE) in portfolio modelling provides a foundation for purchasers to appraise risks from supplier opportunism. We augment existing approaches with reference to inter-organisational theory and the resource-based view to show different modes of inter-firm value creation that act as constituents of a strategic intent for segmentation. Our resulting taxonomy draws together a holistic view of supplier segmentation covering supply market conditions, product/service characteristics, supplier characteristics, buyer characteristics, and buyer-supplier relational factors.

Day, Marc; Magnan, Gregory M.

2010-01-01

354

Multiplex versus multiple taxonomy of paraphilia: case example.  

UK PubMed Central (United Kingdom)

Several different paraphilias are presently diagnosed in some individuals whereas a more parsimonious taxonomy would be that of one multiplex paraphilia. A multiplex paraphilia may be expressed by variations of content at different times in an individual's life or in different situations. The present case example shows the unfolding of a multiplex paraphilia over a lifetime. At age 7 the subject was dressed in public as a girl wearing a diaper as a humiliation for bed-wetting. This experience had 3 paraphilic components that were separately manifested at different times in his life: fetishistic transvestism, pedophilic incest, and infantilism. A multiplex paraphilia taxonomy may lead to improved identification of etiology, prognosis, and treatment of paraphilia.

Lehne GK; Money J

2003-01-01

355

[Numerical taxonomy of the genus Desulfovibrio by group analysis  

UK PubMed Central (United Kingdom)

The Desulfovibrio genus has a particular interest because it includes the microorganisms connected with the corrosion produced microbiologically. The taxonomy of the genus shows disadvantages due to its metabolical and physiological characteristics. In this paper, 14 strains of the Desulfovibrio type were studied from the metabolical point of view. Numeric taxonomy was carried out according to the Group Analysis method, using and comparing the change possibilities of the method. The Consensus Method was also applied. The results obtained indicate a low metabolic activity of the strains with regard to the number of compounds which can be used as energy source. The taxonomic method showed a better structure with more clear divisions, corresponding to Simple Matching coefficient (which coincides with other symmetric coefficients and with the distance coefficient) with average bond (UPGMA). It is estimated that the present classification will vary in time with new strains with different metabolic characteristics. The two groups of bacteria correspond to those with more and less degrading ability.

Pucci OH

1992-07-01

356

A test on the way of superoxide dismutase isozymes to mammalian taxonomy  

UK PubMed Central (United Kingdom)

This paper is to try to find out the significance and effect to apply the analytic method of SOD isozymes to mammalian taxonomy by polyacrylamide gel electrophoresis of the isozymes in the tissues of bats and the erythrocytes of murids. The obtained results show that SOD isozyme is a very useful tool enzyme to distinguish new species or evolution of mammal?because there are marked differences of the mobility, the composition and the distribution of SOD isozymes in different species. But there are not notable differences about above-mentioned characicristics of SOD isozymes in different individual of same species and in different tissue of same individual. The results suggest that it would be not necessity to emphasise the number of animal analysed and not necessity to analyse every tissues. It is very good to make research on protein biochemical types of rare mammals, because they are very scarce and not killed in order to draw materials.

He Xinxia; Zhou Yucan; Shao Lingxiang

1993-01-01

357

On the use of meiofauna in ecological monitoring: who needs taxonomy?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Taxonomic problems have hindered the widespread use of meiobenthos for the purpose of pollution monitoring despite its potential usefulness. The question whether it is necessary to go down to species level in order to distinguish assemblages and stations was studied. From a practical point of view, ...

Herman, P.M.J.; Heip, C.H.R.

358

Contribution to the taxonomy and ecology of the Azorean benthic marine algae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Algal zonation patterns were studied in two sites (Caloura, south coast and Ribeirinha, north coast) of the island of São Miguel, Azores. At each site two stations were studied and the transects revealed the occurrence of two distinct and well established algal zones. In the first zone, daily immers...

Neto, Ana I.

359

The new resources on the Internet and their taxonomy  

Directory of Open Access Journals (Sweden)

Full Text Available The article describes new resources on the Internet and their taxonomy. The revised standard ISBD(CR) for continuing resources is presented, together with changes and differences in the bibliographic description of serials versus integrating resources. The main features of the ISSN-manual revision,standard and format are described, as well as the possibility of using the ISSN number as a resource identifier and as a persistent namespace identifier in the frame of a URN.

Dunja Kal?i?

2004-01-01

360

Learning Taxonomy for Text Segmentation by Formal Concept Analysis  

CERN Multimedia

In this paper the problems of deriving a taxonomy from a text and concept-oriented text segmentation are approached. Formal Concept Analysis (FCA) method is applied to solve both of these linguistic problems. The proposed segmentation method offers a conceptual view for text segmentation, using a context-driven clustering of sentences. The Concept-oriented Clustering Segmentation algorithm (COCS) is based on k-means linear clustering of the sentences. Experimental results obtained using COCS algorithm are presented.

Lupea, Mihaiela; Marian, Zsuzsana

2010-01-01

 
 
 
 
361

Three-parameter asteroid taxonomy classifications  

International Nuclear Information System (INIS)

This paper contains a listing of the classifications for the 357 asteroids with both high-quality visual (U,V,x) photometry and high-quality IRAS albedos used to define the three-parameter taxonomic system. All but one of the three- paramter classes are similiar to those previously recognized using other classification schemes. Eleven classes are found: the C,S,M and E classes have been known for a long time, the A,F,P,D,T and G classes have been generally accepted in recent years, and the K class is new. The P class is contiguous with C's, but is distinguishable from a change in morphology of the distribution of the three parameters. The distribution of P's may be bimodal in U-V. The D's are slightly seperated from the P's. The G's are slighly seperated from the C's; they are not end members of the C distribution. The F's are adjacent to the C's, but seem distinct. The K's lie at the low-color, low-albedo side of the S distribution.

1989-01-01

362

Paleobiogeography and taxonomy of the genus Concholepas (Lamarck, 1801): a review and new evidences Paleobiogeografía y taxonomía del género Concholepas (Lamarck, 1801): una revisión y nuevas evidencias  

Directory of Open Access Journals (Sweden)

Full Text Available The muricid gastropod Concholepas concholepas, known in Chile as 'loco', is an important component of intertidal and shallow subtidal communities, and is one of the main invertebrates targeted by small-scale fishers (divers) in Chile. Because of its ecological importance and economical value, numerous studies have been conducted to describe its life history, ecology and to understand population dynamics, fishery and management. However, little effort has been done to address the causal factor (s) behind its current geographic distribution and moreover little is known about the past distribution of the different species in the genus. In this paper, first we review the paleobiogeography, historical relationships, taxonomy and geographical distribution of Concholepas species, so to contribute in the reconstruction on the past history of the genus. Second, we discuss the robustness of using shell traits when classifying specimens of the genus Concholepas. Third, we evaluate the taxonomic status of C. concholepas including samples from Peru, the continental coast of Chile and Juan Fernández Archipelago, using a molecular approach. Four main conclusions are reached: (1) the evolutionary history of the genus Concholepas has been characterized by successive phenotypically different forms where the fossils species appear to be distinguishable states in the same evolving lineage; (2) the historical biogeography of Concholepas was probably the result of a southward direction process of expansions and extinctions, with the ancestral species being located in south-central Peru; (3) C. concholepas corresponds to a single taxonomic unit along its continental geographical range of distribution; (4) the mtDNA variation present in C. concholepas does not support the existence of the subspecies C. concholepas fernandizianus in the Juan Fernández Archipelago. We suggest that these results should be considered in future ecological, fishery, management and conservation studies on C. concholepas along the Peruvian and Chilean coast and in the Juan Fernández Archipelago.El gastrópodo muricido Concholepas concholepas, conocido en Chile como 'loco', es un importante componente de comunidades marinas intermareales y submareales y es una de las principales especies de invertebrados en la pesquería artesanal chilena. Debido a su importancia y valor económico, se han realizado numerosos estudios para describir su historia de vida, ecología y entender las dinámicas poblacionales, pesquería y manejo. Sin embargo, menores esfuerzos han sido realizados para entender los factores causales detrás de su actual distribución geográfica y más aún poco es conocido acerca de la pasada distribución de las diferentes especies del género. En este trabajo, nosotros primero revisamos la paleobiogeografía, relaciones históricas y taxonomía, de las especies del género Concholepas para contribuir en la reconstrucción de la historia pasada del género. Segundo, discutimos la robustez de usar caracteres morfológicos en la taxonomía del género. Tercero, usando una aproximación molecular evaluamos el estatus taxonómico de C. concholepas incluyendo muestras desde Perú, la costa continental de Chile y del archipiélago de Juan Fernández. Se obtuvieron cuatro conclusiones principales: (1) la historia evolutiva del género Concholepas ha sido caracterizada por sucesivas formas fenotípicamente diferentes, donde las especies fósiles parecen ser estados morfológicos distinguibles de un único linaje evolutivo; (2) la biogeografía histórica de Concholepas parece ser resultado de un proceso continuo de expansión y extinción con dirección sur, con las especies ancestrales localizadas en el centro-sur de Perú; (3) C. concholepas corresponde a una sola unidad taxonómica a lo lago de su rango de distribución continental; (4) la variación en el ADNmt detectada en C. concholepas no apoya la existencia de la subespecie C. concholepas fernandizianus en el Archipiélago de Juan Fernández. Sugerimos que estos resultados deberán ser

LEYLA CÁRDENAS; FRÉDÉRIQUE VIARD; JUAN CARLOS CASTILLA

2008-01-01

363

Quality control for terms and definitions in ontologies and taxonomies  

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Full Text Available Abstract Background Ontologies and taxonomies are among the most important computational resources for molecular biology and bioinformatics. A series of recent papers has shown that the Gene Ontology (GO), the most prominent taxonomic resource in these fields, is marked by flaws of certain characteristic types, which flow from a failure to address basic ontological principles. As yet, no methods have been proposed which would allow ontology curators to pinpoint flawed terms or definitions in ontologies in a systematic way. Results We present computational methods that automatically identify terms and definitions which are defined in a circular or unintelligible way. We further demonstrate the potential of these methods by applying them to isolate a subset of 6001 problematic GO terms. By automatically aligning GO with other ontologies and taxonomies we were able to propose alternative synonyms and definitions for some of these problematic terms. This allows us to demonstrate that these other resources do not contain definitions superior to those supplied by GO. Conclusion Our methods provide reliable indications of the quality of terms and definitions in ontologies and taxonomies. Further, they are well suited to assist ontology curators in drawing their attention to those terms that are ill-defined. We have further shown the limitations of ontology mapping and alignment in assisting ontology curators in rectifying problems, thus pointing to the need for manual curation.

Köhler Jacob; Munn Katherine; Rüegg Alexander; Skusa Andre; Smith Barry

2006-01-01

364

A taxonomy of dignity: a grounded theory study  

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Full Text Available Abstract Background This paper has its origins in Jonathan Mann's insight that the experience of dignity may explain the reciprocal relationships between health and human rights. It follows his call for a taxonomy of dignity: "a coherent vocabulary and framework to characterize dignity." Methods Grounded theory procedures were use to analyze literature pertaining to dignity and to conduct and analyze 64 semi-structured interviews with persons marginalized by their health or social status, individuals who provide health or social services to these populations, and people working in the field of health and human rights. Results The taxonomy presented identifies two main forms of dignity–human dignity and social dignity–and describes several elements of these forms, including the social processes that violate or promote them, the conditions under which such violations and promotions occur, the objects of violation and promotion, and the consequences of dignity violation. Together, these forms and elements point to a theory of dignity as a quality of individuals and collectives that is constituted through interaction and interpretation and structured by conditions pertaining to actors, relationships, settings, and the broader social order. Conclusion The taxonomy has several implications for work in health and human rights. It suggests a map to possible points of intervention and provides a language in which to talk about dignity.

Jacobson Nora

2009-01-01

365

Do diet and taxonomy influence insect gut bacterial communities?  

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Many insects contain diverse gut microbial communities. While several studies have focused on a single or small group of species, comparative studies of phylogenetically diverse hosts can illuminate general patterns of host-microbiota associations. In this study, we tested the hypotheses that (i) host diet and (ii) host taxonomy structure intestinal bacterial community composition among insects. We used published 16S rRNA gene sequence data for 58 insect species in addition to four beetle species sampled from the Sevilleta National Wildlife Refuge to test these hypotheses. Overall, gut bacterial species richness in these insects was low. Decaying wood xylophagous insects harboured the richest bacterial gut flora (102.8 species level operational taxonomic units (OTUs)/sample ± 71.7, 11.8 ± 5.9 phylogenetic diversity (PD)/sample), while bees and wasps harboured the least rich bacterial communities (11.0 species level OTUs/sample ± 5.4, 2.6 ± 0.8 PD/sample). We found evidence to support our hypotheses that host diet and taxonomy structure insect gut bacterial communities (P < 0.001 for both). However, while host taxonomy was important in hymenopteran and termite gut community structure, diet was an important community structuring factor particularly for insect hosts that ingest lignocellulose-derived substances. Our analysis provides a baseline comparison of insect gut bacterial communities from which to test further hypotheses concerning proximate and ultimate causes of these associations.

Colman DR; Toolson EC; Takacs-Vesbach CD

2012-10-01

366

Molecular systematics, phylogeny and ecology of anisakid nematodes of the genus Anisakis Dujardin, 1845: an update.  

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Advances in the taxonomy and ecological aspects concerning geographical distribution and hosts of the so far genetically recognised nine taxa of the nematodes belonging to genus Anisakis (i.e. A. pegreffii, A. simplex s.s., A. simplex C, A. typica, A. ziphidarum, Anisakis sp., A. physeteris, A. brevispiculata and A. paggiae) are here summarized. Genetic differentiation and phylogenetic relationships inferred from allozyme (20 enzyme-loci) and mitochondrial (sequences of cox-2 gene) markers, are revised and compared. The two genetic analyses are congruent in depicting their phylogenetic relationships. Two main clusters are showed to exist in the obtained trees, one encompassing the species A. pegreffii, A. simplex s.s., A. simplex C, A. typica, A. ziphidarum and Anisakis sp.; while, the second including A. physeteris, A. brevispiculata and A. paggiae. The existence of two clades is also supported by their morphological differentiation in adult and larval morphology. Comparison of phylogenetic relationships among Anisakis spp. with those currently available for their cetacean definitive hosts suggests parallelism between host and parasi