scholarly journals Assessing the relationship of ancient and modern populations

2017 ◽  
Author(s):  
Joshua G. Schraiber
Keyword(s):  
Genetic Material ◽  
Sequencing Error ◽  
Effective Population ◽  
Ancient Sample ◽  
Snp Data ◽  
Two Samples ◽  
Low Coverage ◽  
Relationship Of ◽  
Modern Population ◽  
The Relationship

AbstractGenetic material sequenced from ancient samples is revolutionizing our understanding of the recent evolutionary past. However, ancient DNA is often degraded, resulting in low coverage, error-prone sequencing. Several solutions exist to this problem, ranging from simple approach such as selecting a read at random for each site to more complicated approaches involving genotype likelihoods. In this work, we present a novel method for assessing the relationship of an ancient sample with a modern population while accounting for sequencing error and post-mortem damage by analyzing raw read from multiple ancient individuals simultaneously. We show that when analyzing SNP data, it is better to sequence more ancient samples to low coverage: two samples sequenced to 0.5x coverage provide better resolution than a single sample sequenced to 2x coverage. We also examined the power to detect whether an ancient sample is directly ancestral to a modern population, finding that with even a few high cover-age individuals, even ancient samples that are very slightly diverged from the modern population can be detected with ease. When we applied our approach to European samples, we found that no ancient samples represent direct ancestors of modern Europeans. We also found that, as shown previously, the most ancient Europeans appear to have had the smallest effective population sizes, indicating a role for agriculture in modern population growth.

Van rechtvaardigheid naar uitputting en bevlogenheid

2012 ◽  
Vol 25 (2) ◽  
Author(s):  
Peter Verboon ◽  
Klaas Schakel ◽  
Karen van Dam
Keyword(s):  
Organizational Justice ◽  
Affective Commitment ◽  
Positive Behavior ◽  
Mediating Role ◽  
Two Samples ◽  
Group Engagement ◽  
Relationship Of ◽  
The Relationship ◽  
Moderating Role

From justice to exhaustion and engagement. The role of affective commitment to the organization From justice to exhaustion and engagement. The role of affective commitment to the organization In two studies the relationship between perceived organizational justice and emotional exhaustion and engagement was studied. Especially, the role of affective commitment to the organization in this relationship was examined. According to the group engagement model of Tyler and Blader (2003), procedural justice will result in positive behavior and attitudes because it increases commitment to the organization, thus implying that affective commitment mediates the relationship of justice with exhaustion and engagement. Conversely, Glazer and Kruse (2008) argue that a strong commitment to the organization can mitigate the effect of stressors, like injustice perceptions, on exhaustion and engagement, implying a moderating effect of commitment. These models were tested in two samples with employees working in a police organization. Both studies supported the mediating role of commitment; no evidence was found for a moderating role of commitment. The implication of these outcomes and the limitations of the study are discussed.

Protective and Risk Predictors in the Development of Drug Use

1996 ◽  
Vol 26 (1) ◽  
pp. 25-38 ◽  
Author(s):  
József Gerevich ◽  
Erika Bácskai
Keyword(s):  
Drug Use ◽  
Protective Factors ◽  
Drug Users ◽  
Two Dimensions ◽  
Two Samples ◽  
The Family ◽  
Risk Predictors ◽  
Relationship Of ◽  
The Relationship ◽  
Addictive Drug

The authors examined the relationship of two dimensions of the theory of social development—vulnerability (predictors, risk factors) and protectivity—in two samples, schoolchildren aged ten to fifteen years and addictive drug users. On the basis of the Hirschi model of protective factors, they found that the most important protective factors (attachment, commitment, involvement, belief) act against substance use. A surprising finding was that among the predictors of the addicts some forms of escape from the family act against the development of drug use, that is, they can be regarded as a protective predictor. The findings of the study draw attention to the complexity of the vulnerability-protectivity relationship and to the need for further research.

GENETIC CONTROL OF CELLULAR BIOCHEMISTRY

PEDIATRICS ◽  
1960 ◽  
Vol 26 (3) ◽  
pp. 459-465
Author(s):  
David M. Bonner
Keyword(s):  
Genetic Control ◽  
Genetic Material ◽  
Cellular Metabolism ◽  
Human Cells ◽  
Biological Research ◽  
Cellular Biochemistry ◽  
A Cell ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

The Present Paper deals with the cell, but we should not forget that the problems of the cell are at the same time the problems of the whole organism. I would like to consider briefly the gene and the cell, i.e., the relationship of genetic material to metabolism. I would like to consider this problem not only in terms of the cell, but in terms of man as well, since the field of biological research is not a field solely of academic interest. The problems of gene action and of the genetic control of metabolism are fields which are rapidly developing as fields of major importance to medicine, and, in fact, the impact of genetics may be perhaps felt most keenly in the years ahead in the field of pediatrics. In discussing the genetic control of cellular metabolism, one might first ask: What is meant when we speak of the genetics of a cell or of man? Basically, we are concerned with the nature and action of the material which is transmitted from cell to cell or from organism to organism, and which determines the traits of the succeeding generation. It has been clearly shown that the genetic material of the cell resides in its chromosomes, and that chemically, it is a polydeoxyribonucleotide, designated DNA for short.1,2 What makes one think that genetic material controls cellular metabolism? In recent years, the cytology of human cells has enjoyed a great resurgence of interest. It is now possible to grow human cells in tissue culture, and by this means human chromo somes can be studied with great care and precision.

Three essays on the dynamic ownership and governance of U.S. farmer cooperatives

2016 ◽  
Author(s):  
◽  
Jasper Grashuis
Keyword(s):  
Corporate Governance ◽  
Data Analysis ◽  
Agency Theory ◽  
Financial Flexibility ◽  
Farmer Cooperatives ◽  
Two Samples ◽  
Relationship Of ◽  
The Relationship ◽  
Cooperative Governance

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] In order to better understand the long-term behavior of farmer-owned economic organizations, the cooperative life cycle model is advanced and improved via the application of economic theory to each of its five phases. Specifically, transaction cost theory, property rights theory, and agency theory help explain the birth-to-death trajectory of farmer cooperatives, which tinker and reinvent to remain optimal in the competitive market. Tinkering is the adaptation of constitutional rights, policies, and procedures to adjust member objectives, and reinventing is defined as the adaptation of organizational scope or purpose to adjust cooperative actions. As such, tinkering and reinventing are two processes to maintain the long-term cooperative equilibrium. Another aspect of importance to the economic viability of farmer cooperatives is governance, which involves all the mechanisms to manage the separation of control and ownership. Cooperative governance is often assumed to be identical to corporate governance, yet differences in structures and objectives suggest otherwise. Secondary data analysis is conducted to descriptively inform the difference in governance and performance for two samples of agri-food firms and cooperatives. Demographically, all financial characteristics as well as most board and management characteristics are observed to be significantly different for the two samples. According to the main result of the empirical analysis, the causal impact of board size, female directorship, director independence, and director equity ownership on financial performance is also significantly different, which implies cooperative governance is not identical to corporate governance. As compared to the firm, the overall structure of farmer cooperatives is often analyzed in isolation. There exist typologies of the ownership structure, the governance structure, as well as the capital structure. However, the interrelationship is underexplored. To address the gap in the literature, a three-dimensional framework is informed by agency theory, finance theory, and cooperative theory. The three dimensions are member ownership diversity, member control delegation, and financial flexibility, for which a positive linear relationship is hypothesized. Primary survey data is collected for the full population of U.S. farmer cooperative to test hypotheses of the framework. Based on 371 survey responses, a relatively wide tunnel of cooperative life is observed in which low ownership diversity and low member control delegation do not correspond to high financial flexibility. Further, empirical data analysis indicates the relationship of ownership and capital is independent, while the relationship of ownership and governance is bi-directional.

scholarly journals The Decision of Married Woman to Inspect IVA Test in Deli Serdang, Indonesia

2020 ◽  
Vol 2 (1) ◽  
pp. 35-44
Author(s):  
Nurbaity ◽  
Zulfendri ◽  
R. Kintoko Rochadi
Keyword(s):  
Decision Making ◽  
Survey Research ◽  
Power Relations ◽  
Married Woman ◽  
Test Coverage ◽  
Cross Sectional ◽  
Low Coverage ◽  
Relationship Of ◽  
The Relationship

This study aims to find out the decision of married woman to inspect IVA Test in Deli Serdang, Indonesia. This type of research is an analytical survey research with cross sectional approach (Arikunto, 2010), which aims to determine the relationship of power relations with the low coverage of IVA Test coverage. The result shows that the dominance of power in the household, socio-economic that has a relationship with the decision making to conduct an IVA test in Deli Serdang Regency, It can be concluded several things.

scholarly journals Estimation of coalescence probabilities and population divergence times from SNP data

Heredity ◽  
2021 ◽  
Author(s):  
Kristy Mualim ◽  
Christoph Theunert ◽  
Montgomery Slatkin
Keyword(s):  
Demographic History ◽  
Population History ◽  
Divergence Times ◽  
Population Divergence ◽  
High Coverage ◽  
Snp Data ◽  
Population Sizes ◽  
History Of ◽  
Relationship Of ◽  
The Relationship

AbstractWe present a method called the G(A|B) method for estimating coalescence probabilities within population lineages from genome sequences when one individual is sampled from each population. Population divergence times can be estimated from these coalescence probabilities if additional assumptions about the history of population sizes are made. Our method is based on a method presented by Rasmussen et al. (2014) to test whether an archaic genome is from a population directly ancestral to a present-day population. The G(A|B) method does not require distinguishing ancestral from derived alleles or assumptions about demographic history before population divergence. We discuss the relationship of our method to two similar methods, one introduced by Green et al. (2010) and called the F(A|B) method and the other introduced by Schlebusch et al. (2017) and called the TT method. When our method is applied to individuals from three or more populations, it provides a test of whether the population history is treelike because coalescence probabilities are additive on a tree. We illustrate the use of our method by applying it to three high-coverage archaic genomes, two Neanderthals (Vindija and Altai) and a Denisovan.

Clarifying the Relationship of Dissociative Experiences to Suicide Ideation and Attempts: A Multimethod Examination in Two Samples

2021 ◽  
Author(s):  
Mikayla C. Pachkowski ◽  
Megan L. Rogers ◽  
Boaz Y. Saffer ◽  
Nicole M. Caulfield ◽  
E. David Klonsky
Keyword(s):  
Suicide Ideation ◽  
Dissociative Experiences ◽  
Two Samples ◽  
Relationship Of ◽  
The Relationship

scholarly journals Using Ancient Samples in Projection Analysis

2015 ◽  
Author(s):  
Melinda A Yang ◽  
Montgomery Slatkin
Keyword(s):  
Population Model ◽  
Reference Population ◽  
Demographic Model ◽  
Ancient Sample ◽  
Human Genomes ◽  
Test Genome ◽  
Projection Analysis ◽  
The One ◽  
Relationship Of ◽  
The Relationship

Projection analysis is a useful tool for understanding the relationship of two populations. It compares a test genome to a set of genomes from a reference population. The projection's shape depends on the historical relationship of the test genome's population to the reference population. Here, we explore the effects on the projection when ancient samples are included in the analysis. First, we conduct a series of simulations in which the ancient sample is directly ancestral to a present-day population (one-population model) or the ancient sample is ancestral to a sister population that diverged before the time of sampling (two-population model). We find that there are characteristic differences between the projections for the one-population and two-population models, which indicate that the projection can be used to determine whether a test genome is directly ancestral to a present day population or not. Second, we compute projections for several published ancient genomes. We compare three Neanderthals, the Denisovan and three ancient human genomes to European, Han Chinese and Yoruba reference panels. We use a previously constructed demographic model and insert these seven ancient genomes and assess how well the observed projections are recovered.

scholarly journals Assessment of the relationship of yield and its contributing traits in wheat

2022 ◽  
pp. 4-10
Keyword(s):  
Grain Yield ◽  
Genetic Material ◽  
Spike Length ◽  
F1 Hybrids ◽  
Path Coefficient ◽  
Cereal Crop ◽  
Thousand Grain Weight ◽  
Path Coefficient Analysis ◽  
Relationship Of ◽  
The Relationship

Wheat is an essential source of nutrition for humans and an important cereal crop of Pakistan due to its widespread use as food. To fulfill the nutrition needs of boosted population, crop yield must be improved. In this perspective, we conducted the experiment reported in this paper to achieve correlation and path coefficient attributes given by yield-related traits. Our study enables to understand the association and contribution of nine traits toward grain production. The genetic material was comprised of seven parents and twelve F1 hybrids. Correlation analysis showed that grain yield per spike, thousand grain weight, spike length, and number of tillers per plant have positive and significant correlation with grain yield per plant, at both genotypic and phenotypic level. Path coefficient analysis revealed that direct effects of number of tillers per plant, grain yield per spike, and spike length were positive. This data persuaded that selection based on these traits could be useful for breeding purposes to higher grain yield.

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