Comparison on botanical morphology in different populations of Changium smyrnioides

2010 ◽  
Author(s):  
WANG Changlin
Keyword(s):  
Different Populations ◽  
Changium Smyrnioides

Gene Polymorphisms and Their Association to Coronavirus Family Infections: Susceptibility in Different Populations

2020 ◽  
Vol 5 ◽  
Keyword(s):  
Genetic Variants ◽  
Viral Infections ◽  
Human Leukocyte ◽  
Asian Population ◽  
African Region ◽  
Mediterranean Populations ◽  
Susceptibility To Infection ◽  
Asian Populations ◽  
Spread Pattern ◽  
Different Populations

Human leukocyte antigen (HLA) loci are highly polymorphic and determine differential features of the immune response in subjects from different regions. HLA genes have been proposed to determine genetic susceptibility to several diseases, particularly to viral infections. Moreover, it has been suggested that each ethnic group could have a different specificity of T-lymphocyte reactivity to the same viral infections. In this review, we analyzed the distribution of HLA types in countries of the Asian, European and North African region. Also, we studied the relation between these HLA polymorphisms and susceptibility to infection by the coronavirus. Our findings indicated that homozygosity would increase susceptibility to viral infections and, in some cases, to coronavirus infection. HLA types showing higher susceptibility were reported in Asian population, including China, Singapore, and Taiwan. In contrast, lower susceptibility HLA variants were detected among African populations, some Asian populations, and Mediterranean populations. The presented evidence along with the spread pattern of COVID-19 infection suggests that HLA genetic variants might be related to its infection susceptibility and severity. The investigation of HLA genetic variants distribution would be a useful tool to predict different populations’ susceptibility to viral infections.

Some comparative aspects of a longitudinal growth study in normal spanish children and other longitudinal studies

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S93-S97 ◽  
Author(s):  
A. FERRANDEZ ◽  
E. MAYAYO ◽  
M. RODRIGUEZ ◽  
J.M. ARNAL ◽  
J. CARO ◽  
...  
Keyword(s):  
Longitudinal Studies ◽  
Environmental Conditions ◽  
Regional Differences ◽  
Longitudinal Growth ◽  
Growth Study ◽  
Growth Studies ◽  
Different Populations ◽  
Catch Up

Abstract The differences existing among some european longitudinal growth studies make it necessary to be cautious in the use of standards constructed on different populations. The improvement of the environmental conditions during the last 20 years is probably the most important cause of the "catch-up" phenomenon of the spanish stature. It is probable that racial characteristics also play a role, even in the same country as can be appreciated on comparing two spanish longitudinal studies based on children originary from different regions. All of wich indicates the need to use own standards in those countries wich, like ours, have lived through a period of intenses changes. Even exploratory studies of regional differences in the same country seem necesary.

Identification of sibling species in the genus Eucyclops from water-bodies of Ukraine and Russia using crossbreeding studies

2014 ◽  
Vol 25 (1-2) ◽  
pp. 61-68 ◽  
Author(s):  
V. I. Monchenko ◽  
L. P. Gaponova ◽  
V. R. Alekseev
Keyword(s):  
Cryptic Species ◽  
River Basin ◽  
Black Sea ◽  
Species Complex ◽  
River Basins ◽  
Water Bodies ◽  
Similar Species ◽  
Basin Water ◽  
Different Populations ◽  
Baltic Sea Basin

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.

Morphological peculiarities of seeds of some species of the genus Epipactis Zinn. (Orchidaceae Juss.) of Ukrainian flora

2019 ◽  
Vol 11 (1) ◽  
pp. 93-100
Author(s):  
T Ljubka ◽  
O Tsarenko ◽  
I Tymchenko
Keyword(s):  
Seed Coat ◽  
Cell Walls ◽  
Morphological Study ◽  
Population Level ◽  
Intercellular Spaces ◽  
Different Populations ◽  
Periclinal Walls ◽  
High Degree ◽  
Shape And Size ◽  
Generative Organs

The investigation of macro- and micromorphological peculiarities of seeds of four species of genus Epipactis (Orchidaceae) of Ukrainian flora were carried out. The genus Epipactis is difficult in the in in taxonomic terms and for its representatives are characterized by polymorphism of morphological features of vegetative and generative organs of plants and ability of species to hybridize. The aim of the research was to perform a comparative morphological study of seeds of E. helleborine, E. albensis, E. palustris, E. purpurata and to determine carpological features that could more accurately identify species at the stage of fruiting. A high degree of variation in the shape of the seeds in different populations within the species and overlap of most quantitative carpological characteristics of studied species are noted. There were no significant differences in micromorphological features of the structure of the testa at species or population level. The reticulate surface of the testa is characteristic of all species, the cells of testa are mostly elongated, penta-hexagonal, individual cells almost isodiametric-pentagonal. From the micropillary to the chalasal end, a noticeable change in the shape and size of the seed coat cells is not observed. There are no intercellular spaces, the anticlinal walls of adjacent cells are intergrown and the boundaries between them become invisible. The outer periclinal walls have a single, mainly longitudinal thin ribbed thickenings. Anticlinal cell walls are thick, dense, smooth. The longitudinal Anticlinal walls are almost straight, transverse - straight or sometimes curved in some cells. Epicuticular deposits on the periclinal walls are absent. It is concluded that the use of macro and micromorphological characteristics of seeds of these species for clearer diagnosis at the stage of fruiting is low informative.

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