scholarly journals Comparing The Relative Contribution Of Individual And Environmental Factors To The Intent To Remain In An Engineering Major, By Gender

2020 ◽  
Author(s):  
Elizabeth Creamer ◽  
Peggy Meszaros ◽  
Catherine Amelink
Keyword(s):  
Environmental Factors ◽  
Intent To Remain ◽  
Relative Contribution

scholarly journals Multi-Year NDVI Values as Indicator of the Relationship between Spatiotemporal Vegetation Dynamics and Environmental Factors in the Qaidam Basin, China

2021 ◽  
Vol 13 (7) ◽  
pp. 1240
Author(s):  
Junpeng Lou ◽  
Guoyin Xu ◽  
Zhongjing Wang ◽  
Zhigang Yang ◽  
Sanchuan Ni
Keyword(s):  
Environmental Factors ◽  
Vegetation Dynamics ◽  
Vegetation Index ◽  
Qaidam Basin ◽  
Elevation Gradient ◽  
Practical Significance ◽  
Elevation Gradients ◽  
Relative Contribution ◽  
Significant Difference ◽  
Different Altitudes

The Qaidam Basin is a unique and complex ecosystem, wherein elevation gradients lead to high spatial heterogeneity in vegetation dynamics and responses to environmental factors. Based on the remote sensing data of Moderate Resolution Imaging Spectroradiometer (MODIS), Tropical Rainfall Measuring Mission (TRMM) and Global Land Data Assimilation System (GLDAS), we analyzed the spatiotemporal variations of vegetation dynamics and responses to precipitation, accumulative temperature (AT) and soil moisture (SM) in the Qaidam Basin from 2001 to 2016. Moreover, the contribution of those factors to vegetation dynamics at different altitudes was analyzed via an artificial neural network (ANN) model. The results indicated that the Normalized Difference Vegetation Index (NDVI) values in the growing season showed an overall upward trend, with an increased rate of 0.001/year. The values of NDVI in low-altitude areas were higher than that in high-altitude areas, and the peak values of NDVI appeared along the elevation gradient at 4400–4600 m. Thanks to the use of ANN, we were able to detect the relative contribution of various environmental factors; the relative contribution rate of AT to the NDVI dynamic was the most significant (35.17%) in the low-elevation region (< 2900 m). In the mid-elevation area (2900–3900 m), precipitation contributed 44.76% of the NDVI dynamics. When the altitude was higher than 3900 m, the relative contribution rates of AT (39.50%) and SM (38.53%) had no significant difference but were significantly higher than that of precipitation (21.97%). The results highlight that the different environmental factors have various contributions to vegetation dynamics at different altitudes, which has important theoretical and practical significance for regulating ecological processes.

scholarly journals Hereditary and environmental factors causing total joint replacement due to hip and knee osteoarthritis – a twin registry based prospective cohort study

2016 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Karin Magnusson ◽  
Kåre Birger Hagen
Keyword(s):  
Environmental Factors ◽  
Knee Joint ◽  
Joint Replacement ◽  
Total Joint Replacement ◽  
Population Based ◽  
Genetic Contribution ◽  
Questionnaire Response ◽  
Knee Oa ◽  
Relative Contribution ◽  
Twin Registry

The relative contribution of genetic factors and more modifiable environmental factors to a clinically<br />relevant osteoarthritis (OA) diagnosis is unkown. In this paper we present an ongoing study on the genetic<br />contribution to total joint replacement (TJR) due to hip and knee OA and effects of lifestyle and lifestyle<br />related conditions on TJR due to OA. We have linked data on incident OA from the Norwegian Arthroplasty<br />Registry were l with the Norwegian Twin Registry on the National ID number in 2014, thus obtaining a<br />population based cohort of same-sex twins born 1915-60. Data on height, weight and lifestyle were selfreporteded<br />in questionnaires conducted between 1978 and 1992. The monozygotic (MZ) and dizygotic<br />(DZ) concordances as well as the genetic contribution vs. contribution of more modifiable, environmental<br />factors to arthroplasty will be examined in separate analyses for the hip and the knee joint. The sample<br />comprised N=18058 twins (N=3803 MZ and N=5226 DZ pairs) including N=9650 (53.4%) females and a<br />mean (SD) age of 38 (12.3) years at questionnaire response. Some preliminary analyses have been performed<br />showing a higher concordance for TJR due to hip OA among MZ (0.36) than DZ twins (0.16), which may<br />be consistent with a genetic contribution to hip OA. TJR due to hip OA may be determined by genetic<br />factors. Results for the knee joint as well as final results from hereditary analyses and co-twin control<br />analyses of will be published consecutively from 2016.

scholarly journals Disentangling age-dependent DNA methylation: deterministic, stochastic, and nonlinear

2020 ◽  
Author(s):  
O. Vershinina ◽  
M. Ivanchenko ◽  
M.G. Bacalini ◽  
A. Zaikin ◽  
C. Franceschi
Keyword(s):  
Dna Methylation ◽  
Environmental Factors ◽  
Methylation Level ◽  
Signal To Noise Ratio ◽  
Cross Sectional ◽  
Ample Evidence ◽  
Systematic Assessment ◽  
Relative Contribution ◽  
Age Dependent ◽  
The Individual

ABSTRACTDNA methylation variability arises due to concurrent genetic and environmental influences. Each of them is a mixture of regular and noisy sources, whose relative contribution has not been satisfactorily understood yet. We conduct a systematic assessment of the age-dependent methylation by the signal-to-noise ratio and identify a wealth of “deterministic” CpG probes (about 90%), whose methylation variability likely originates due to genetic and general environmental factors. The remaining 10% of “stochastic” CpG probes are arguably governed by the biological noise or incidental environmental factors. Investigating the mathematical functional relationship between methylation levels and variability, we find that in about 90% of the age-associated differentially methylated positions, the variability changes as the square of the methylation level, whereas in the most of the remaining cases the dependence is linear. Furthermore, we demonstrate that the methylation level itself in more than 15% cases varies nonlinearly with age (according to the power law), in contrast to the previously assumed linear changes. Our findings present ample evidence of the ubiquity of strong DNA methylation regulation, resulting in the individual age-dependent and nonlinear methylation trajectories, whose divergence explains the cross-sectional variability. It may also serve a basis for constructing novel nonlinear epigenetic clocks.

scholarly journals Implications of predictable and unpredictable environmental factors in common bean VCU trials in Minas Gerais

2014 ◽  
Vol 14 (3) ◽  
pp. 146-153 ◽  
Author(s):  
Lidiane Kely de Lima ◽  
Magno Antonio Patto Ramalho ◽  
Ângela de Fátima Barbosa Abreu ◽  
Fernando Henrique Ribeiro Barrozo Toledo ◽  
Ricardo Augusto Diniz Cabral Ferreira
Keyword(s):  
Environmental Factors ◽  
Grain Yield ◽  
Common Bean ◽  
Total Variation ◽  
Minas Gerais ◽  
The State ◽  
Good Strategy ◽  
Yield Data ◽  
Relative Contribution ◽  
Environmental Variations

The aim of this study was to estimate the relative contribution of predictable and unpredictable environmental variations to the lines x environments interaction and verify if it is possible to reduce the number of evaluation environments of the Value for Cultivation and Use Trials (VCU) conducted in Minas Gerais, Brazil. We used grain yield data from 166 VCU trials of common bean conducted in the state from 2002 to 2012. Individual and joint analyses of variance of the environments were carried out for each two-year period and the contribution of each source of variation to total variation was estimated. Subsequently, ecovalence was used, and joint analyses of variance were made considering different numbers of environments by means of resampling. The source of variation that most contributes to the interaction is location. Reduction in the number of environments in the VCU trials is not a good strategy for recommendation of cultivars in Minas Gerais.

Exploring Genetic and Environmental Influences on Miscarriage Rates: A Twin Study

2010 ◽  
Vol 13 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Andrea V. Burri ◽  
Lynn Cherkas ◽  
Timothy D. Spector
Keyword(s):  
Environmental Factors ◽  
Twin Study ◽  
Variance Components ◽  
Model Fitting ◽  
Genetic Influence ◽  
Shared Environment ◽  
Pair Correlations ◽  
Relative Contribution ◽  
Genetic And Environmental Factors ◽  
Common Variable

AbstractMiscarriage is the most common type of pregnancy loss, occurring in up to 15% of clinically recognized pregnancies. Our understanding of the etiology is still limited but is believed to be multifactorial, including endocrine and anatomical abnormalities, immunologic, genetic and lifestyle factors. The aim of this study was to explore whether genetic variability in miscarriage is under any genetic influence. 3234 MZ and DZ female twins completed postal self-completion questionnaires on pregnancies. Rates were adjusted for total number of pregnancies. The relative contribution of genetic and environmental factors to variation in miscarriage was assessed using twin intra-pair correlations and quantified using a variance components model fitting approach. We found 22.7% of our twins reporting having suffered at least one miscarriage. Current age, age at first pregnancy and higher number of pregnancies all had a significant influence on reported miscarriage. The concordance of miscarriage was similar in identical and non-identical twins, 26% and 27%, respectively. Shared environment and predominantly random error and unique environment rather than genetic factors best explained the total variation of miscarriage. To our knowledge, this is the first large twin study exploring heritability of miscarriage which unlike the vast majority of common variable traits, shows no significant genetic influence. In the absence of clear environmental factors, these results suggest the influence of random factors.

Complex genetic and environmental relationships between psychological distress, fatigue and immune functioning: a twin study

1999 ◽  
Vol 29 (2) ◽  
pp. 269-277 ◽  
Author(s):  
I. HICKIE ◽  
B. BENNETT ◽  
A. LLOYD ◽  
A. HEATH ◽  
N. MARTIN
Keyword(s):  
Psychological Distress ◽  
Environmental Factors ◽  
Immune Function ◽  
Familial Aggregation ◽  
Delayed Type Hypersensitivity ◽  
Immune Responsiveness ◽  
Environmental Correlations ◽  
Relative Contribution ◽  
Skin Response ◽  
Genetic And Environmental Factors

Background. Although there is considerable support for adverse relationships between states of psychological and somatic distress and immune response, there is little evidence in humans of the relative contribution of genetic and environmental factors.Methods. This study utilized a twin methodology to examine the interplay between psychological distress, fatigue and immune function. We recorded a number of measures of distress, including conventional depression and anxiety as well as the somatic symptom of prolonged fatigue, and immune responsiveness (by delayed-type hypersensitivity skin response) in 124 normal adult twin pairs (79 monozygotic, 45 dizygotic).Results. While there were strong genetic influences on the psychological distress and fatigue factors (only some of which are common to both), familial aggregation of immune responsiveness arose mainly from environmental factors shared by both members of a twin pair. Phenotypic correlations between psychological and immune measures were negligible, but multivariate genetic modelling revealed that these masked larger genetic and environmental correlations of opposite sign. Negative environmental effects of psychological distress and fatigue on immune responsiveness were countered by a positive genetic relationship between psychological distress and immune function.Conclusions. Our study suggests that current psychoneuroimmunological hypotheses in humans need to be modified to place increasing importance on the individual's genotype. In this cohort immune responsiveness varied in response to a complex interplay of genetic and environmental factors. Additionally, although psychological distress and fatigue had some shared genetic determinants, independent genetic and environmental risk factors for fatigue were also identified.

scholarly journals How Nonshared Environmental Factors Come to Correlate with Heredity

2020 ◽  
Author(s):  
Christopher Beam ◽  
Patrizia Pezzoli ◽  
Jane Mendle ◽  
S. Alexandra Burt ◽  
Michael C. Neale ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genetic Models ◽  
Future Research ◽  
Longitudinal Models ◽  
Behavioral Genetic ◽  
Relative Contribution ◽  
Environment Effects ◽  
Gene Environment ◽  
Genetic And Environmental Factors ◽  
Over Time

Conventional longitudinal behavioral genetic models estimate the relative contribution of genetic and environmental factors to stability and change of traits and behaviors. Longitudinal models rarely explain the processes that generate observed differences between genetically and socially related individuals. We propose that exchanges between people and their environments (i.e., phenotype-environment effects) can explain the emergence of observed differences over time. Such models, however, require violation of the independence assumption of standard behavioral genetic models, that is, uncorrelated genetic and environmental factors (Beam &amp; Turkheimer, 2013; de Kort, Dolan, &amp; Boomsma, 2012; Dolan, De Kort, Van Beijsterveldt, Bartels, &amp; Boomsma, 2014). We review how specification of phenotype-environment effects contributes to understanding observed changes in genetic variability over time and longitudinal correlations among nonshared environmental factors. We then provide an example using 30 days of positive and negative affect scores from an all-female sample of twins. Results demonstrate that the phenotype-environment effects explain how heritability estimates fluctuate as well as how nonshared environmental factors persist over time. We discuss possible mechanisms underlying change in gene-environment correlation over time, the advantages and challenges of including gene-environment correlation in longitudinal twin models, and recommendations for future research.

A Male Monozygotic Twinship Discordant for Homosexuality

1971 ◽  
Vol 118 (547) ◽  
pp. 675-682 ◽  
Author(s):  
K. Davison ◽  
H. Brierley ◽  
C. Smith
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Prison Population ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
The Third ◽  
Relative Contribution ◽  
Quantitative Rating ◽  
Genetic And Environmental Factors ◽  
Sexual Identification

The relative contribution of genetic and environmental factors to the development of homosexual behaviour is a controversial subject. The original suggestion that homosexuality is a purely inherited trait has been attributed to Krafft-Ebing (Kallmann, 1952). Perhaps the strongest support for this view was Kallmann's series of 40 male monozygotic twin pairs showing 100 per cent concordance for the overt practice and quantitative rating of homosexual behaviour (Kallmann, 1952). This report has been criticized, and Kallmann later conceded that the 100 per cent concordance was possibly a statistical artefact (Kallmann, 1960). Habel (1950), who obtained the index twins from a prison population, found concordant homosexuality in 3 out of 5 monozygotic pairs (60 per cent), but none of 5 dizygotic pairs. In a more recent study, Heston and Shields (1968) found concordant homosexuality in 2 out of 5 monozygotic pairs (40 per cent) and 1 out of 7 dizygotic pairs (14 per cent). Heston and Shields (1968) also report a family with a sibship of 14 which included 3 pairs of male monozygotic twins, in two of which both twins were homosexual and in the third both heterosexual; no environmental factors which differentiated the homosexual from the heterosexual sibs could be detected. These workers also refute the suggestion that the tendency for monozygotic twins to be more alike with regard to homosexuality than dizygotic twins is related not to genetic factors but to problems of sexual identification which predispose to homosexuality (Money, 1962) by pointing out that there is no evidence that monozygotic twins per se are especially prone to become homosexual.

scholarly journals Etiology of Parkinson's Disease

2003 ◽  
Vol 30 (S1) ◽  
pp. S10-S18 ◽  
Author(s):  
Zhigao Huang ◽  
Raúl de la Fuente-Fernández ◽  
A. Jon Stoessl
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Environmental Factors ◽  
Neurodegenerative Disorders ◽  
Caffeine Intake ◽  
Genetic Mutations ◽  
Abnormal Protein ◽  
Relative Contribution ◽  
Genetic And Environmental Factors

There is growing recognition that Parkinson's disease (PD) is likely to arise from the combined effects of genetic predisposition as well as largely unidentified environmental factors. The relative contribution of each varies from one individual to another. Even in situations where more than one family member is affected, the predominant influence may be environmental. Although responsible for only a small minority of cases of PD, recently identified genetic mutations have provided tremendous insights into the basis for neurodegeneration and have led to growing recognition of the importance of abnormal protein handling in Parkinson's as well as other neurodegenerative disorders. Abnormal protein handling may increase susceptibility to oxidative stress; conversely, numerous other factors, including oxidative stress and impaired mitochondrial function can lead to impaired protein degradation. A limited number of environmental factors are known to be toxic to the substantia nigra; in contrast, some factors such as caffeine intake and cigarette smoking may protect against the development of PD, although the mechanisms are not established. We review the various genetic and environmental factors thought to be involved in PD, as well as the mechanisms that contribute to selective nigral cell death.

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