Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "populations" wg kryterium: Wszystkie pola


Tytuł:
The local populations of the fungus Schizophyllum commune Fr. as drivers of its biodiversity
Autorzy:
Boiko, Sergiy
Powiązania:
https://bibliotekanauki.pl/articles/2040907.pdf
Data publikacji:
2021
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
Schizophyllum commune
gene drift
genetic structure
local populations
terrain
Opis:
Changes that occur on the local level can explain the processes on the population level and, at the same time, are the driving force of species adaptation. This manuscript reports data about genetic diversities of the fungus Schizophyllum commune on the level of a local population. Objects of the study were dicarious cultures of S. commune collected from 38 basidiocarps grown on the territory of Holosiivskyi National Nature Park, Lysa Hora Regional Landscape Park and Feofaniya forest parcel (Ukraine). Results showed similarity of genetic variability of S. commune in different local populations. The heterozygote deficiency of some loci that was discovered might have resulted from new forms of allozymes that have not become widespread or due to small population sizes. The degree of differentiation of genes between local studied populations was moderate due to the high flow of genes. The absence of spatial structuration of genotypes is established, and the Mantel test showed a lack of interconnection between the genetic component and the geographical coordinates of the samples. It has been suggested that wind direction and terrain are the factors that influence the genetic structure of local populations.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2021, 63, 4; 308-316
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The genetic diversity of HLA DRB1* alleles among Indian and African populations
Autorzy:
Nandakumar, R.
Powiązania:
https://bibliotekanauki.pl/articles/1158256.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Admixture
Demography
HLA DRB1
Indian and African populations
Migration
Population Genetics
Opis:
The HLA system is highly polymorphic and commonly used as a marker to understand core population genetical aspects such as stratification, human migration, predisposition to diseases and tissue transplantation compatibility. Although HLA alleles are generally treated as equidistant molecular units in population genetic studies, the diversity of DNA allelic frequencies among populations is also considered to be crucial to interpret the observed HLA polymorphisms. This study compares the variation of HLA DRB1 alleles across various subgroups of both Indian and African Populations, using their respective allelic frequencies. The HLA DRB1 allelic frequencies for 3,153 individuals of 32 subgroups of both Indian and African populations, were collected from the Allele Frequency Net Database (AFND). Correlation matrix and Grid diagram were compiled using the R statistical package. Allele frequencies were analyzed for the respective population subgroups using XLSTAT. The North East Indian populations were completely devoid of HLA DRB1* 16, which is fairly present in south Indian populations. The South Indian populations harbor both HLA DRB1* 10 and HLA DRB1* 15 at relatively higher levels but are very scarce of HLA DRB1* 07, HLA DRB1* 09, HLA DRB1* 12 and HLA DRB1* 13. The alleles HLA DRB1* 03, HLA DRB1* 04 and HLA DRB1* 07 could represent an epicenter for the admixture of African, North-East Indian and South Indian populations.
Źródło:
World Scientific News; 2018, 114; 15-29
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of populations of Dreissena polymorpha (Pall.) in lakes
Autorzy:
Lewandowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/83702.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Mikołaja Kopernika. Wydział Biologii i Ochrony Środowiska. Stowarzyszenie Malakologów Polskich
Opis:
The paper summarizes the results of a long-term study on the ecology of Dreissena polymorpha (Pall.) in several dozen lakes of different size, depth and trophy. The abundance of adults, planktonic larvae, and settled postveligers was found to vary widely between the lakes, localities within a lake, and years. The temperature influences the period of appearance and abundance dynamics of planktonic larvae; wind affects their vertical and horizontal distribution in the water column; winds and water currents displace settling postveligers. Settling postveligers display preferences for various natural substrates: most often they settle on submerged plants, especially perennials. The age structure of D. polymorpha settled on plants (dominance of young individuals, at most 3 years old) differs from that in colonies settled on the littoral bottom. The abundance of mussel populations in lakes is primarily determined by the mortality at the transition from planktonic to sedentary life, and by the mortality of individuals settled on submerged plants.
Źródło:
Folia Malacologica; 2001, 09, 4
1506-7629
Pojawia się w:
Folia Malacologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stochastic vortices in periodically reclassified populations
Autorzy:
Guerreiro, Gracinda
Mexia, João
Powiązania:
https://bibliotekanauki.pl/articles/729714.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Markov chains
stochastic vortices
Opis:
Our paper considers open populations with arrivals and departures whose elements are subject to periodic reclassifications. These populations will be divided into a finite number of sub-populations.
Assuming that:
a) entries, reclassifications and departures occur at the beginning of the time units;
b) elements are reallocated at equally spaced times;
c) numbers of new elements entering at the beginning of the time units are realizations of independent Poisson distributed random variables;
we use Markov chains to obtain limit results for the relative sizes of the sub-populations corresponding to the states of the chain. Namely we will obtain conditions for stability of the relative sizes for transient and recurrent states as well as for all states. The existence of such stability corresponds to the existence of a stochastic structure based either on the transient or on the recurrent states or even on all states. We call these structures stochastic vortices because the structure is maintained despite entrances, departures and reallocations.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2008, 28, 2; 209-227
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Populations of parasitic nematodes colonizing Jerusalem artichoke (Helianthus tuberosus L.)
Autorzy:
Zapalowska, A.
Skwiercz, A.
Powiązania:
https://bibliotekanauki.pl/articles/57124.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The populations of parasitic nematodes colonizing the rhizosphere of Helianthus tuberosus L. grown in Polish plantations were studied in the summer of 2016 and the spring of 2017. A total of 35 nematode species were identified: Paratrichodorus pachydermus, Trichodorus cylindricus, T. viruliferus, Longidorus attenuatus, L. elongatus, L. leptocephalus, Criconema annuliferum, Criconemoides informis, Mesocriconema rusticum, M. solivagum, M. xenoplax, Paratylenchus nanus, P. neoamblycephalus, P. projectus, Bitylenchus dubius, B. maximus, Merlinius brevidens, M. nothus, Scutylenchus quadrifer, S. tartuensis, Helicotylenchus digonicus, H. pseudorobustus, H. vulgaris, Rotylenchus pumilus, R. robustus, Pratylenchus crenatus, P. fallax, P. neglectus, Hirschmanniella gracilis, Aphelenchoides fragariae, Aphelenchus avenae, A. eremitus, Ditylenchus dipsaci, and D. medicaginis. Aphelenchoides fragariae and Ditylenchus dipsaci could be foliar pathogens of H. tuberosus L. This is the first study to demonstrate the presence of A. fragariae on the leaves of the Jerusalem artichoke in Poland. The frequencies of occurrence and population densities of the 35 nematode species were determined.
Źródło:
Acta Societatis Botanicorum Poloniae; 2018, 87, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
COMPARING PROPORTIONS OF SENSITIVE ITEMS IN TWO POPULATIONS WHEN USING POISSON AND NEGATIVE BINOMIAL ITEM COUNT TECHNIQUES
Autorzy:
Kowalczyk, Barbara
Wieczorkowski, Robert
Powiązania:
https://bibliotekanauki.pl/articles/453738.pdf
Data publikacji:
2017
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
sensitive questions
Poisson and negative binomial item count techniques
latent data
two populations
asymptotic test
Opis:
Sensitive attributes are extremely difficult to be measured directly. Recently new indirect methods of questioning, called Poisson and negative binomial item count techniques, have been proposed by [Tian et al. 2014]. This paper focuses on important problem of comparing proportions of sensitive items in two populations when using new indirect method. Proper statistical theory is introduced, including tests for equality of two sensitive proportions followed by derivation of their asymptotic power functions. Simulation studies are conducted to illustrate the problem.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2017, 18, 1; 68-77
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differences among Juniperus excelsa populations as revealed at morphological traits
Autorzy:
Yucedag, C.
Gailing, O.
Powiązania:
https://bibliotekanauki.pl/articles/41657.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Opis:
The comparison of phenotypic trait differentiation and genetic differentiation at selectively neutral genetic markers can indicate divergent selection on traits. Phenotypic trait differentiation (PST) andtwo multivariate analysis methods were used to determine the level of differentiation and relationships among seven Juniperus excelsa populations basedon 13 morphological characters of their cones, seeds, juvenile seedlings and 1+0 year old seedlings. Significant differences among populations were found for all morphological characters (P<0.001) apart from cotyledon length using ANOVA. According to Penrose and Squared Euclidean distances, the southeastern populations Bucak-Kestel and Gölhisar-Gölhisar (0.970; 12.374) were most similar. Aksu-Sorgun andE ðirdir-Barla populations, separated by a mountain range, were the most different populations (4.647; 47.157). Evaluatedas a whole, both multivariate analysis methods gave similar results. Phenotypic trait differentiation (PST) for 1+0 year oldseed lings that were grown in a common environment was similar in magnitude for the majority of traits as genetic differentiation at nuclear microsatellite markers (FST) suggesting the absence of divergent selection on these traits.
Źródło:
Dendrobiology; 2013, 70
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variation and genetic structure of Serratula lycopifolia populations (Vill.) kern.(Asteraceae) in Poland and adjacent regions
Autorzy:
Cieslak, E.
Powiązania:
https://bibliotekanauki.pl/articles/57308.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Botaniczne
Źródło:
Acta Societatis Botanicorum Poloniae; 2013, 82, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies