scholarly journals Reduced levels of DNA polymorphism and fixed between-population differences in the centromeric region of Drosophila ananassae.

Genetics ◽  
1992 ◽  
Vol 132 (4) ◽  
pp. 1039-1045 ◽  
Author(s):  
W Stephan ◽  
S J Mitchell
Keyword(s):  
Dna Polymorphism ◽  
Restriction Site ◽  
Total Sample ◽  
Dna Polymorphisms ◽  
Drosophila Ananassae ◽  
Site Variation ◽  
V Region ◽  
Two Populations ◽  
Distal Gene

Abstract We have estimated DNA sequence variation within and between two populations of Drosophila ananassae, using six-cutter restriction site variation at vermilion (v) and furrowed (fw). These two gene regions are located close to the centromere on the left and right X chromosome arms, respectively. In the fw region, no DNA polymorphism was detected within each population. In the v region, average heterozygosity per nucleotide was very low in both populations (pi = 0.0005 in the Burma population, and 0.0009 in the India population). These estimates are significantly lower than those from loci in more distal gene regions. The distribution of DNA polymorphisms between both populations was also striking. At fw, three fixed differences between the Burma and India populations were detected (two restriction site differences and one insertion/deletion of approximately 2 kb). At v, each DNA polymorphism in high frequency in the total sample was nearly fixed in one or the other population, although none of them reached complete fixation. The observed pattern of reduced variation within populations and fixed differences between populations appears to correlate with recombination rate. We conclude that recent hitchhiking associated with directional selection is the best explanation for this pattern. The data indicate that different selective sweeps have occurred in the two populations. The possible role of genetic hitchhiking in rapid population differentiation in gene regions of restricted recombination is discussed.

scholarly journals The genetic structure of natural populations of Drosophila melanogaster. XXII. Comparative study of DNA polymorphisms in northern and southern natural populations.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 753-761
Author(s):  
T S Takano ◽  
S Kusakabe ◽  
T Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Drift ◽  
Nucleotide Diversity ◽  
Restriction Site ◽  
Natural Populations ◽  
Dna Polymorphisms ◽  
Restriction Map ◽  
Random Genetic Drift ◽  
Two Populations ◽  
Restriction Site Polymorphisms

Abstract Restriction map variation in four gene regions (Adh, Amy, Pu and Gpdh) was surveyed for 86 second chromosomes from northern (Aomori) and southern (Ogasawara) Japanese populations of Drosophila melanogaster (43 chromosomes from each population). The regions examined cover a total of 62 kilobases. Estimates of nucleotide diversity (pi) were approximately constant across the gene regions and populations examined. The distribution of restriction site polymorphisms was compatible with the expectation from the neutral mutation-random genetic drift hypothesis, but insertion/deletion polymorphisms were not consistent with it. While the two populations shared a majority of restriction site polymorphisms, frequencies of individual restriction site variants were significantly different between the two populations at 7 out of 35 segregating sites. In addition, an insertion in the Amy region was found in 15 chromosomes from the Ogasawara sample but absent in the Aomori sample. A considerable difference was observed in the number of rare insertions and deletions between the two populations. The numbers of aberrations uniquely represented were 16 in the Ogasawara sample and only 3 in the Aomori sample. These findings suggest that the two populations were differentiated from each other to some degree by means of random genetic drift and/or other factors.

scholarly journals DNA POLYMORPHISM DETECTABLE BY RESTRICTION ENDONUCLEASES

Genetics ◽  
1981 ◽  
Vol 97 (1) ◽  
pp. 145-163 ◽  
Author(s):  
Masatoshi Nei ◽  
Fumio Tajima
Keyword(s):  
Statistical Methods ◽  
Nucleotide Diversity ◽  
Restriction Site ◽  
Restriction Enzymes ◽  
Evolutionary Change ◽  
Restriction Endonucleases ◽  
Dna Polymorphisms ◽  
Effective Population ◽  
Mt Dna ◽  
Two Populations

ABSTRACT Data on DNA polymorphisms detected by restriction endonucleases are rapidly accumulating. With the aim of analyzing these data, several different measures of nucleon (DNA segment) diversity within and between populations are proposed, and statistical methods for estimating these quantities are developed. These statistical methods are applicable to both nuclear and non-nuclear DNAs. When evolutionary change of nucleons occurs mainly by mutation and genetic drift, all the measures can be expressed in terms of the product of mutation rate per nucleon and effective population size. A method for estimating nucleotide diversity from nucleon diversity is also presented under certain assumptions. It is shown that DNA divergence between two populations can be studied either by the average number of restriction site differences or by the average number of nucleotide differences. In either case, a large number of different restriction enzymes should be used for studying phylogenetic relationships among related organisms, since the effect of stochastic factors on these quantities is very large. The statistical methods developed have been applied to data of Shah and Langley on mitochondrial (mt)DNA from Drosophila melanogaster, simulans and virilis. This application has suggested that the evolutionary change of mtDNA in higher animals occurs mainly by nucleotide substitution rather than by deletion and insertion. The evolutionary distances among the three species have also been estimated.

Peran kepemilikan institusional, perencanaan pajak dan dewan komisaris asing terhadap nilai perusahaan

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Anita Ade Rahma ◽  
Lisa Nabawi ◽  
Ronni Andri Wijaya
Keyword(s):  
Significant Influence ◽  
Firm Value ◽  
Stock Exchange ◽  
Investment Decisions ◽  
Total Sample ◽  
Tax Planning ◽  
Purposive Sampling ◽  
Institutional Leadership ◽  
Company Value

The purpose of this study is to analyze the role of institutional leadership, tax planning and foreign board of commissioners on firm value. The population in this study were 615 companies listed on the Indonesia Stock Exchange in 2015-2017. The sample was chosen using purposive sampling to get a total sample of 325 companies with a total of 975 observations of company data. The results of this study indicate that institutional leadership and tax planning have no role in increasing company value. While the foreign board of commissioners showed a significant influence on the value of the company. This proves that there is a need for diversity in the structure of the board that can trigger an increase in the value of the company. In addition, the presence of a foreign board is needed for the progress of the companyKeywords: Investment decisions; funding decisions; dividend policy; company value

PERANAN ANGGOTA KELOMPOK TANI DALAM MENINGKATKAN PRODUKSI PADI SAWAH DI DESA KOROBHERA KECAMATAN MEGGO KABUPATEN SIKKA

2020 ◽  
Vol 21 (1) ◽  
pp. 61-70
Author(s):  
Toncerius M. Lesu ◽  
S.P.N. Nainiti ◽  
Serman Nikolaus
Keyword(s):  
Sampling Method ◽  
Simple Random Sampling ◽  
Total Sample ◽  
Rice Production ◽  
Average Score ◽  
Maximum Score ◽  
Central Production ◽  
Group Members ◽  
Farmer Groups

The aim of this research is to find out how big the role of the farmer group members in increasing rice production at Korobhera Village, Meggo Subdistrict, Sikka District. The research has been done on April to May 2019. This is a qualitative study with purposive sampling considering the site was one of rice central production. The objectives of the study were to know : 1) how big the role of the farmer group members to productivity increasing in the area of research ; 2) the constraints faced by the members of the farmer group. Sample was done randomly using simple random sampling method with a total sample size of 50 people, who were the members of four farmer groups existed. The results of research indicated that the role of farmer group members in increasing rice production at the location of research was high, shown by the percentage of the accomplishment maximum score from average score in the amount of 75,65% (average score 87). The constraints faced by members of farmer group were quite similar, which were financial capital limits problem, uncaged livestocks and the availability of production tools was often not on time.

HUBUNGAN PERAN KADER POSYANDU DENGAN STATUS GIZI BALITA

2018 ◽  
Vol 9 (02) ◽  
pp. 192
Author(s):  
Wiwid Wahyuningsih ◽  
Atik Setiyaningsih
Keyword(s):  
Nutritional Status ◽  
Total Sample ◽  
Nutrition Status ◽  
P Value ◽  
Chi Square ◽  
Cross Sectional ◽  
Central Java ◽  
Good Nutrition ◽  
Nutritional Status Of Children

ABSTRAKLatar Belakang : Keberadaan kader di posyandu sebagai salah satu sistem penyelenggarakan pelayanan sangat dibutuhkan. Mereka adalah ujung tombak  pelayanan kesehatan yang merupakan kepanjangtanganan puskesmas Jawa Tengah tahun 2011 jumlah gizi kurang 5,35% dan gizi buruk 0,10%. Untuk Kabupaten Semarang dari 23.562 balita yang ditimbang pada tahun 2011 gizi lebih 1,13%, gizi baik 93,51%, gizi kurang 4,86% dan gizi buruk 0,49% (DepKes Prov Jateng, 2011). Tujuan Penelitian : Penelitian ini bertujuan untuk mengetahui hubungan peran kader posyandu dengan status gizi balita. Metode Penelitian : Desain penelitian ini adalah survey analitik dengan menggunakan pendekatan cross sectional. Populasi dalam penelitian ini adalah seluruh balita di Posyandu Mawar di Desa Gedangan sejumlah 40 responden, dengan teknik total sampling dan analisa data chi square. Hasil Penelitian : Hasil perhitungan chi square di peroleh X² hitung 10.644 pada df=4, P.value 0.031 dimana probabilitas lebih kecil dari level of significant 5 % (0,001 < 0,05) berarti Ha diterima dan Ho ditolak. Kesimpulan : ada hubungan antara peran kader posyandu dengan status gizi pada balita.Kata Kunci : peran kader , status gizi balitaCADERE ROLE RELATIONSHIP WITH NUTRITIONAL STATUS OF CHILDREN POSYANDUABSTRACTBackground : posyandu cadre in Existence as one of the 56th's service system is urgently needed. They are the tip of the Spear is a kepanjangtanganan health services clinics in Central Java in 2011 the amount of nutrition less 5.35% 0.10% and malnutrition. To Semarang from 23.562 toddler who weighed in 2011 more nutritional 1.13%, 93,51%, good nutrition nutrition less 4.86% and 0.49% poor nutrition (Department of Health Central Java Prov., 2011). Objective : the research aims to find out the relationship role of posyandu cadre with the nutritional status of children. Methods : the design of this research is a survey using the analytic approach of cross sectional. The population in this study are all the toddlers at the Rose in the village of Posyandu Gedangan some 38 respondents, with total sample techniques and data analysis a chi square. The results :. The chi square calculation results in getting X ² count 10.644 on df = 4, P. value 0.031 where probability is smaller than the level of significant 5% (0.001 < 0.05) mean Ha Ho accepted and rejected. Conclusion : there is a connection between the role of cadres of posyandu with nutritional status on toddlers.Keywords : the role of cadres, toddler nutrition status

The Role of Race in Relations of Social Support to Hippocampal Volumes Among Older Adults

2021 ◽  
pp. 016402752110172
Author(s):  
Desirée C. Bygrave ◽  
Constance S. Gerassimakis ◽  
Denée T. Mwendwa ◽  
Guray Erus ◽  
Christos Davatzikos ◽  
...  
Keyword(s):  
Social Support ◽  
Older Adults ◽  
African American ◽  
Disease Risk ◽  
Total Sample ◽  
Hippocampal Volume ◽  
Brain Pathology ◽  
Resonance Imaging ◽  
African American Older Adults

Evidence suggests social support may buffer brain pathology. However, neither its association with hippocampal volume, a marker of Alzheimer’s disease risk, nor the role of race in this association has been fully investigated. Multiple regression analyses examined relations of total social support to magnetic resonance imaging-assessed gray matter (GM) hippocampal volumes in the total sample ( n = 165; mean age = 68.48 year), and in race-stratified models of African American and White older adults, adjusting for select covariates. Results showed greater social support was associated with greater GM hippocampal volumes among African American older adults only ( p < .01). Our findings suggest greater total social support may play a role in supporting the hippocampus, particularly among African American older adults, who had lower hippocampal volumes than their White counterparts. Further research is needed to test these questions longitudinally and examine which aspects of social support may promote hippocampal integrity, specifically.

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

scholarly journals Microtubule–microtubule sliding by kinesin-1 is essential for normal cytoplasmic streaming in Drosophila oocytes

2016 ◽  
Vol 113 (34) ◽  
pp. E4995-E5004 ◽  
Author(s):  
Wen Lu ◽  
Michael Winding ◽  
Margot Lakonishok ◽  
Jill Wildonger ◽  
Vladimir I. Gelfand
Keyword(s):  
Cytoplasmic Streaming ◽  
Cell Types ◽  
Nurse Cells ◽  
Wild Type ◽  
Actin Cortex ◽  
Microtubule Motor ◽  
Multiple Cell ◽  
Cytoplasmic Microtubules ◽  
Two Populations

Cytoplasmic streaming in Drosophila oocytes is a microtubule-based bulk cytoplasmic movement. Streaming efficiently circulates and localizes mRNAs and proteins deposited by the nurse cells across the oocyte. This movement is driven by kinesin-1, a major microtubule motor. Recently, we have shown that kinesin-1 heavy chain (KHC) can transport one microtubule on another microtubule, thus driving microtubule–microtubule sliding in multiple cell types. To study the role of microtubule sliding in oocyte cytoplasmic streaming, we used a Khc mutant that is deficient in microtubule sliding but able to transport a majority of cargoes. We demonstrated that streaming is reduced by genomic replacement of wild-type Khc with this sliding-deficient mutant. Streaming can be fully rescued by wild-type KHC and partially rescued by a chimeric motor that cannot move organelles but is active in microtubule sliding. Consistent with these data, we identified two populations of microtubules in fast-streaming oocytes: a network of stable microtubules anchored to the actin cortex and free cytoplasmic microtubules that moved in the ooplasm. We further demonstrated that the reduced streaming in sliding-deficient oocytes resulted in posterior determination defects. Together, we propose that kinesin-1 slides free cytoplasmic microtubules against cortically immobilized microtubules, generating forces that contribute to cytoplasmic streaming and are essential for the refinement of posterior determinants.

scholarly journals Hierarchical Analysis of Nucleotide Diversity in Geographically Structured Populations

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 629-639 ◽  
Author(s):  
Kent E Holsinger ◽  
Roberta J Mason-Gamer
Keyword(s):  
Nucleotide Diversity ◽  
Restriction Site ◽  
Rooted Tree ◽  
Structured Populations ◽  
Hierarchical Analysis ◽  
Restriction Site Variation ◽  
Hierarchical Levels ◽  
Site Variation ◽  
The Mean ◽  
Mean Time

Abstract Existing methods for analyzing nucleotide diversity require investigators to identify relevant hierarchical levels before beginning the analysis. We describe a method that partitions diversity into hierarchical components while allowing any structure present in the data to emerge naturally. We present an unbiased version of Nei's nucleotide diversity statistics and show that our modification has the same properties as Wright's  F  ST. We compare its statistical properties with several other F  ST estimators, and we describe how to use these statistics to produce a rooted tree of relationships among the sampled populations in which the mean time to coalescence of haplotypes drawn from populations belonging to the same node is smaller than the mean time to coalescence of haplotypes drawn from populations belonging to different nodes. We illustrate the method by applying it to data from a recent survey of restriction site variation in the chloroplast genome of Coreopsis grandiflora.

scholarly journals Private specificities of H-2K and H-2D loci as possible selective targets for effector lymphocytes in cell-mediated immunity.

1975 ◽  
Vol 141 (1) ◽  
pp. 11-26 ◽  
Author(s):  
B D Brondz ◽  
I K Egorov ◽  
G I Drizlikh
Keyword(s):  
T Lymphocytes ◽  
Target Cells ◽  
Cell Mediated Immunity ◽  
Skin Grafts ◽  
Immune Lymphocytes ◽  
Direct Cytotoxicity ◽  
Cross Absorption ◽  
Private Specificity ◽  
Two Populations

Receptors of effector T lymphocytes of congeneic strains of mice do not recognize public H-2 specificities and react to private H-2 specificities only. This has been established with the use of three tests: direct cytotoxicity assay of immune lymphocytes upon target cells, specific absorption of the lymphocytes on the target cells, and rejection of skin grafts at an accelerated fashion. Immunization with two private H-2 specificities in the system C57BL/10ScSn leads to B10.D2 induces formation of two corresponding populations of effector lymphocytes in unequal proportion: a greater part of them is directed against the private specificity H-2.33 (Kb), while the smaller part is towards H-2.2 (Db) private specificity. These two populations of effector lymphocytes do not overlap, as demonstrated by experiments on their cross-absorption on B10.D2 (R107), B10.D2 (R101), B10.A(2R), and B10.A(5R) target cells, as well as on mixtures of R107 and R101 targets. Following removal of lymphocytes reacting with one of the private H-2 specificities, lymphocytes specific to the other specificity are fully maintained. A mixture of target cells, each bearing one of the two immunizing private specificities, absorbs 100% of the immune lymphocytes and is totally destroyed by them. It is suggested that H-2 antigens are natural complexes of hapten-carrier type, in which the role of hapten is played by public H-2 specifities and that of the carrier determinant by either private H-2 specificities or structures closely linked to them. Various models of steric arrangement of MHC determinants recognized by receptors of effector T lymphocytes are discussed.

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