scholarly journals Variation in Population Structures of Tropical Freshwater Eels, Anguilla Marmorata, A. Bicolor Bicolor and A. Bengalensis Bengalensis, in the Indo-Pacific

2021 ◽  
Author(s):  
Takaomi Arai ◽  
Hussein Taha
Keyword(s):  
Tropical Species ◽  
Pacific Region ◽  
Oceanic Current ◽  
Dispersion Patterns ◽  
Population Structures ◽  
Different Populations ◽  
And Migration ◽  
Current Systems ◽  
Freshwater Eels ◽  
Spawning Sites

Abstract Freshwater eels, genus Anguilla, have a distinctive catadromous life history, which could be associated with certain oceanic current systems and offshore spawning sites. Thus, migration and dispersion patterns are believed to be important factors influencing the population structures of each species. Temperate eel species are well studied, while little research has been conducted on the tropical counterparts that comprise two-thirds of all eel species. The population structures of three tropical species, A. marmorata, A. bicolor bicolor and A. bengalensis bengalensis, which are distributed widely in the Indo-Pacific region, were explored by means of DNA sequence analysis of mitochondrial cytochrome c oxidase subunit I (COI). This study found that A. bicolor bicolor had two genetically distinct populations, and these different populations co-occur geographically in the Indo-Pacific region, while A. marmorata and A. bengalensis bengalensis showed a panmictic-population structure in this region. The populations of A. bicolor bicolor were also found to have lower genetic variability than the populations of A. marmorata and A. bengalensis bengalensis. This study is the first to explore the population genetic structure of A. bengalensis bengalensis. The present results also suggest plausible dispersion and migration of these tropical species into their continental habitats.

Surnames and population structure in the Doctrine of Belén, Altos de Arica, Viceroyalty of Peru (1750–1813)

2021 ◽  
pp. 1-13
Author(s):  
Emma Alfaro ◽  
Xochitl Inostroza ◽  
José E. Dipierri ◽  
Daniela Peña Aguilera ◽  
Jorge Hidalgo ◽  
...  
Keyword(s):  
Population Structure ◽  
Indigenous Population ◽  
Random Mating ◽  
Quantitative Information ◽  
Geographic Space ◽  
Documentary Sources ◽  
Cultural Variables ◽  
The Social ◽  
Population Structures ◽  
And Migration

Abstract The analysis of multiple population structures (biodemographic, genetic and socio-cultural) and their inter-relations contribute to a deeper understanding of population structure and population dynamics. Genetically, the population structure corresponds to the deviation of random mating conditioned by a limited number of ancestors, by restricted migration in the social or geographic space, or by preference for certain consanguineous unions. Through the isonymic method, surname frequency and distribution across the population can supply quantitative information on the structure of a human population, as they constitute universal socio-cultural variables. Using documentary sources to undertake the Doctrine of Belén’s (Altos de Arica, Chile) historical demography reconstruction between 1763 and 1820, this study identified an indigenous population with stable patronymics. The availability of complete marriage, baptism and death records, low rates of migration and the significant percentage of individuals registered and constantly present in this population favoured the application of the isonymic method. The aim of this work was to use given names and surnames recorded in these documentary sources to reconstruct the population structure and migration pattern of the Doctrine of Belén between 1750 and 1813 through the isonymic method. The results of the study were consistent with the ethno-historical data of this ethnic space, where social cohesion was, in multiple ways, related to the regulation of daily life in colonial Andean societies.

scholarly journals Demographic and social degradation in the Lubelskie Voivodeship as a peripheral area of East Poland

2018 ◽  
Vol 41 (41) ◽  
pp. 7-27 ◽  
Author(s):  
Małgorzata Flaga ◽  
Monika Wesołowska
Keyword(s):  
Rural Areas ◽  
Political Transformation ◽  
Social Infrastructure ◽  
Economic Changes ◽  
Peripheral Area ◽  
Population Structures ◽  
Natural Movement ◽  
Regional Factors ◽  
Post War ◽  
And Migration

Abstract Eastern regions of Poland are regarded as areas where numerous unfavourable socio-economic phenomena appear and accumulate. These are the results of historical conditions as well as post-war border localization and various processes, primarily in terms of economy. The consequences of the political transformation of the state in the 1990s and profound social and economic changes in recent decades are also crucial drivers of many disadvantageous changes in the region. The article shows population processes which can be recognized nowadays in Eastern Poland, and the attention of the authors is focused on the peripheral rural areas of the region. General tendencies reported in the text are based on the cases from the Lubelskie Voivodeship where concentration of the demographic and social problems is particularly noticeable. The analyses comprise changes of population growth and its components (natural movement and migration), population structures as well as some characteristics concerning the quality and conditions of inhabitants’ lives. The main causes of negative processes shaping the population, including domestic, regional and micro-regional factors, are also presented. The final part of the article deals with the most important outcomes of population changes which are reflected in the progressing ageing of society, the decline of villages and social infrastructure, among other facts. These unfavourable phenomena are shown in the context of the future development of the region.

Mineral deposits and chalcogen gases

1993 ◽  
Vol 57 (389) ◽  
pp. 599-606 ◽  
Author(s):  
Martin Hale
Keyword(s):  
Ore Deposits ◽  
Anomalous Dispersion ◽  
Mineral Deposits ◽  
Oxidation Reactions ◽  
Sulphide Minerals ◽  
Sulphide Ore ◽  
Dispersion Patterns ◽  
Sulphide Deposits ◽  
High Concentrations ◽  
And Migration

AbstractSulphide minerals and their analogues yield gases as a result of oxidation reactions. Even where sulphide minerals are in contact with mildly reducing groundwaters, S2- ions pass into solution and their dispersion patterns can be detected in soil as acid-released H2S. In more oxidising conditions, the metastable gases COS and CS2 are generated. Anomalous dispersion patterns of COS have been reported in soils above more than ten sulphide ore deposits, many of them concealed beneath transported exotic overburden. High concentrations of CS2 occur in the soils over several of the same deposits and uniquely reflect others. Anomalies of SO2 over sulphide deposits are confined to arid terrains. Certain anomalous dispersion patterns of arsenic and tellurium in soils are attributed to the generation and migration of unspecified gases from the oxidation of arsenide and telluride minerals.

Tropical species of Kurzia (Crustacea, Cladocera) with a description of Kurzia brevilabris sp.nov.

1986 ◽  
Vol 64 (11) ◽  
pp. 2590-2602 ◽  
Author(s):  
R. Rajapaksa ◽  
C. H. Fernando
Keyword(s):  
New Species ◽  
Sri Lanka ◽  
Tropical Species ◽  
Tropical Region ◽  
Oriental Region ◽  
Morphological Variations ◽  
Different Populations ◽  
A New Species

Kurzia longirostris (Daday) from throughout the tropical region was examined, together with a review of all previous records worldwide. It is clear that what was considered K. longirostris consists of two species in the Oriental region. This includes a new species, Kurzia brevilabris sp.nov. It differs from K. longirostris in the head pore configuration, the structure of the labrum, and the arrangement of the submarginal setules along the posteroventral corner of the carapace. A detailed description of the species is given. A detailed redescription of K. longirostris is given based on the types and material from Sri Lanka. The morphological variations observed in different populations of the tropical region are also included in the description.

scholarly journals Assessment and mapping of demographic potential of urbanized territories of the Baikal-Mongol region

2021 ◽  
Vol 885 (1) ◽  
pp. 012028
Author(s):  
N V Vorobyev ◽  
A N Vorobyev
Keyword(s):  
Urban Areas ◽  
Irkutsk Region ◽  
Quantitative Characteristics ◽  
Working Age ◽  
Population Structures ◽  
Demographic Processes ◽  
The Republic ◽  
And Migration ◽  
Population Demographic ◽  
Demographic Potential

Abstract This article provides an assessment of the demographic potential of the Baikal-Mongolian region, which unites the adjacent territories of the two countries. The cores of the research site are the urbanized territories of Irkutsk, Ulan-Ude and Ulan-Bator, and communications are railways and highways connecting the main centres. The demographic potential is characterized by the level and possibilities for the development of demographic processes and population structures, and mainly numerous quantitative characteristics of the population of the territory are used. The authors limited themselves to using quantitative characteristics of the demographic potential according to statistical data for 2019–2020 within the territories of the municipal districts and urban districts of the Irkutsk region, the Republic of Buryatia and aimags of Mongolia. Data on density and proportion of urban population reflect the size of the main urban areas. Data on demographic processes reflect the characteristics of the natural and migration movement of the population. Demographic structures are represented by the age structure and the demographic load of the working-age population, which is minimal throughout Mongolia and in the suburbs of Russian regional centres. Generalizing characteristics of demographic potential calculated from the average sum of individual indicators.

scholarly journals DNA barcoding of a tropical anguillid eel, Anguilla bicolor (Actinopterygii: Anguilliformes), in Indo-Pacific region and notes on its population structure

2021 ◽  
Vol 38 ◽  
pp. 1-7
Author(s):  
Ahmad Fathi Norarfan ◽  
Siti Shazwani Azreena Mokti ◽  
Hussein Taha ◽  
Muhamad Amin ◽  
Muhamad Ali ◽  
...  
Keyword(s):  
Population Structure ◽  
Indian Ocean ◽  
Dna Barcoding ◽  
Stock Assessment ◽  
Molecular Evidence ◽  
Pacific Region ◽  
Mitochondrial Cytochrome ◽  
The Indian Ocean ◽  
Different Populations ◽  
Important Fish

The tropical anguillid eel, Anguilla bicolor McCelland, 1844, includes two subspecies, Anguilla bicolor bicolor McCelland, 1844 and Anguilla bicolor pacifica Schmidt, 1928, and is distributed across the Indo-Pacific region. Although A. bicolor is widely distributed and recognized as an important fish resource in the Indo-Pacific region, few studies have been conducted on its genetic variation and population structure. DNA barcoding of A. bicolor specimens collected in the Indo-Pacific region was carried out in this study using mitochondrial cytochrome c oxidase subunit I. Anguilla bicolor was found to diverge genetically, which supported its classification into two different subspecies. In addition, our study showed that A. bicolor bicolor had two genetically distinct populations/groups, and these different populations co-occur geographically in Indonesia and Malaysia in the eastern Indian Ocean. Our findings suggest that the eel larvae might be transported from at least two geographically different spawning grounds in the Indian Ocean, and then recruited to and settled in the same habitats in Indonesian and Malaysian waters. The molecular evidence calls for further research on the life history, stock assessment and protection of the populations of A. bicolor bicolor in Indonesia and Malaysia.

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