Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Environment”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,171 records · Page 65Linked to original sources
PubMed2003

Genotype x environment interaction for milk production in Guernsey cattle.

International genetic evaluations that use national genetic evaluation results as input need to acknowledge country boundaries. The current model for international evaluation treats each country as a genetically separate trait, i.e., assumes milk production to be similar within country, but different between countries. The use of cow performance records does not require such restriction, and allows for other statistical models to consider genotype x environment interaction. First-lactation records from 40,000 Guernsey cows in four countries (Australia, Canada, United States, and South Africa) were used to detect and describe genotype x environment interaction for milk production traits. Five statistical models were considered: single-trait across-county (ST), single-trait across-country with heterogeneous residual variance (SThet), multiple-trait across-country (MT), multiple-trait herd cluster model (HC), and reaction norm model (RR). For the herd cluster model, herds were clustered into groups based on information on herd management, genetic composition, and climate. Reaction norms describe the phenotype expressed by a genotype as a function of the environment, and was modeled by random regression on the herd average for peak milk yield as the descriptor of production environment. Gibbs sampling was used to make inferences about the parameters of interest, and models were compared based on goodness of fit and deviance information criterion. Posterior mode of the heritability for the single-trait model was 0.32, and ranged from 0.15 to 0.53 for models SThet and MT. Posterior mode of the genetic correlations between countries estimated with model MT were generally high (0.78 to 0.90). However, posterior SD were high (up to 0.15 for Australia-South Africa), and values near unity for the genetic correlations were not unlikely. Model HC gave more precise inferences but lower goodness of fit compared with model MT. Results from model RR provided evidence for heterogeneity of genetic variances. This model was least supported by the data, probably because heterogeneity of residual variances was not considered. Among the models in this study, the one with homogeneous genetic and heterogeneous residual variances across countries fitted best to the data, and we expect a model for which the assumption of homogeneous genetic variance is relaxed to show an even better fit to the data.

Animals↗
PubMed2004

Genotype x environment interaction for grazing vs. confinement. II. Health and reproduction traits.

Continual selection for increased milk yield for more than 40 yr, combined with the antagonistic relationship between increasing yield, somatic cell count, and fertility, have resulted in sires that may not be optimal for producing daughters for grazing systems where seasonal calving is very important. The objective of this study was to investigate the possible existence of a genotype x environment interaction (G x E) in grazing vs. confinement herds within the United States for lactation average somatic cell score (LSCS), days open (DO), days to first service (DFS), and number of services per conception (SPC). Grazing herds were defined as those that utilized grazing for at least 6 mo each year and were enrolled in Dairy Herd Improvement (DHI). Control herds were confinement DHI herds of similar size in the same states. For LSCS, the performance of daughters in grazing and control herds was examined using linear regression of LSCS on the November 2000 USDA-DHIA sire predicted transmitting abilities (PTA) for SCS. Genetic parameters for all traits were estimated using REML in a bivariate animal model that treated the same trait in different environments as different traits. Rank correlations were calculated between sires' estimated breeding values for LSCS, calculated separately for sires in both environments. The coefficient of regression of daughter LSCS on sire PTA was less in grazing herds than in control herds. The coefficient of regression for control herds was closer to expectation. Estimates of heritability were approximately 0.12 for LSCS, and less than 0.05 for the reproduction traits. Heritabilities for DO, DFS, and SPC were slightly higher for control herds. Estimates of genetic correlation for each reproductive trait between the 2 environments were high and not significantly different from unity. Generally, these traits appear to be under similar genetic control, but a lower coefficient of regression of LSCS on sire PTA for SCS in grazing herds suggests differences in daughter performance in grazing herds may be overstated based on current PTA for SCS.

Animals↗
PubMed2004

Genotype x environment interaction for age at first calving in Brazilian and Colombian Holsteins.

The objective was to determine whether there is a genotype x environment interaction for age at first calving (AFC) in Holstein cattle in Brazil and Colombia. Data included 51,239 and 25,569 first-lactation records from Brazil and Colombia, respectively. Of 4230 sires in the data, 530 were North American sires used in both countries. Analyses were done using the REML bi-trait animal model, and AFC was considered as a distinct characteristic in each country. Fixed effects of contemporary group (herd-calving year), sire genetic group, and cow genetic group, and random effects of animal and residual variation were included in the model. Average AFC in Brazil and Colombia were 29.5 +/- 4.0 and 32.1 +/- 3.5 mo, respectively. Additive and residual genetic components and heritability coefficient for AFC in Brazil were 2.21 mo2, 9.41 mo2, and 0.19, respectively, whereas for Colombia, they were 1.02 mo2, 6.84 mo2, and 0.13, respectively. The genetic correlation of AFC between Brazil and Colombia was 0.78, indicating differences in ranking of sires consistent with a genotype x environment interaction. Therefore, in countries with differing environments, progeny of Holstein sires may calve at relatively younger or older ages compared with contemporary herdmates in one environment versus another.

Aging↗
PubMed2006

Genotype by environment interaction for somatic cell score across bulk milk somatic cell count and days in milk.

The objective of this paper was to investigate the importance of a genotype x environment interaction (G x E) for somatic cell score (SCS) across levels of bulk milk somatic cell count (BMSCC), number of days in milk (DIM), and their interaction. Variance components were estimated with a model including random regressions for each sire on herd test-day BMSCC, DIM, and the interaction of BMSCC and DIM. The analyzed data set contained 344,029 test-day records of 24,125 cows, sired by 182 bulls, in 461 herds comprising 13,563 herd test-days. In early lactation, considerable G x E effects were detected for SCS, indicated by 3-fold higher genetic variance for SCS at high BMSCC compared with SCS at low BMSCC, and a genetic correlation of 0.72 between SCS at low and at high BMSCC. Estimated G x E effects were smaller during late lactation. Genetic correlations between SCS at the same level of BMSCC, across DIM, were between 0.43 and 0.89. The lowest genetic correlation between SCS measures on any 2 possible combinations of BMSCC and DIM was 0.42. Correlated responses in SCS across BMSCC and DIM were, on some occasions, less than half the direct response to selection in the response environment. Responses to selection were reasonably high among environments in the second half of the lactation, whereas responses to selection between environments early and late in lactation tended to be low. Selection for reduced SCS yielded the highest direct response early in lactation at high BMSCC.

Animals↗
PubMed1976

Influence of environment on passive immunity in calves.

Passive immunity in neonatal calves is influenced by environment. Placing newly born Holstein calves (108 head) in three different housing environments (shade, cooled shade, hutch) during hot weather produced differences in body temperature, serum cortocosteroids, immunoglobulin IgG1 concentrations, and mortality. Experimental design permitted examination of effects due to treatments, time, differences in colostrum, and climatic environment in an analysis of variance. Calves exposed to the hotter, less desirable environment responded by having a higher mortality, higher serum corticosteroid concentration, and lower serum immunoglobulin IgG1 at 2 and 10 days after birth. All of these were correlated. Calves that died had serum immunoglobulin IgG1 falling below the mean for all experimental calves.

Adrenal Cortex Hormones↗
PubMed1996

Effects of supplemental shade on thermoregulatory response of calves to heat challenge in a hutch environment.

Holstein (n = 12) and Guernsey (n = 6) calves, housed in hutches, were used to evaluate the complex relationships among external environment, housing microclimate, and thermal status of calves. The study was conducted during the summer; 9 calves were housed in hutches under supplemental shade, and 9 calves were maintained in hutches under direct sunlight. Environmental and calf temperatures were measured twice daily at 0700 and 1500 h, which included determinations of air temperature, inner and outer surface temperatures of the hutch, rectal and skin temperatures of the calf, and respiration rate. Outer and inner surface temperatures of the hutch were lower under supplemental shade. Hutch air temperature was highly correlated with inner surface temperature and therefore was lower in the shaded environment. During the p.m. period, when heat stress was highest, calves housed in a shaded hutch environment had lower skin temperatures and respiration rates than did unshaded calves. Body temperature and respiration rates increased less for calves in shade than for calves in sun. These data define the relationship between the calf and the environment. Supplemental shade diminished the severity of heat stress experienced by calves that were housed in hutches during the summer.

Animals↗
PubMed1999

Genetic analysis of dairy cattle production traits in a management intensive rotational grazing environment.

Management intensive rotational grazing is a low input form of dairy herd management that is practiced by an increasing number of US dairy producers. However, concerns exist regarding the predictability of progeny performance in a grazing environment because most US dairy sires are progeny tested under conventional conditions of herd management. Lactation data from 27 Wisconsin dairy herds that have practiced management intensive rotational grazing for at least 4 yr were analyzed, as were data from three randomly chosen groups of control herds. Coefficients of regression of progeny milk, fat, and protein yields on USDA sire PTA values were 0.99, 0.76, and 0.96, respectively, from the grazing herds. In the control herds, regression coefficients for milk, fat, and protein yields averaged 0.95, 0.98, and 0.88, respectively. Therefore, progeny performance of grazing herds was predicted adequately by national sire PTA values that were derived primarily from conventionally managed herds. Heritability estimates for milk, fat, and protein yields were 0.23, 0.17, and 0.26, respectively, in the grazing herds and 0.24, 0.27, and 0.27, respectively, in a pooled data set containing all control herds. Estimated genetic correlations between production traits in the grazing environment and in the control environment were 0.92, 0.88, and 0.99 for milk, fat, and protein yields, respectively. These correlations, as well as the regression coefficients, indicate that interaction of genotype by environment is not important for these management systems, and nearly optimal genetic progress can be achieved by selecting AI sires progeny tested under traditional management conditions.

Animal Feed↗
PubMed2004

Work environment structure and psychological ownership: the mediating effects of control.

Current theorists on the psychology of possession highlight control as an important route in the development of feelings of ownership. In the present article, the authors hypothesized that the extent to which individuals experience control over their job and work environment is positively associated with feelings of ownership for their job and the organization. The authors used supervisory report data on work environment structure and self-reports on experienced control and psychological ownership to test for the mediating effects of experienced control in the relationship between the work environment structure and psychological ownership. The authors found that experienced control mediates the relationship between 3 sources of work environment structure--technology, autonomy, and participative decision making--and psychological ownership of the job and (to a lesser extent) the organization. The authors proposed implications of the findings and directions of further research.

Adolescent↗
PubMed2006

[Dermatomycosis and environment].

Environments may act as reservoirs for pathogenic fungi, a determinant of the establishment of fungal infection, or an exacerbating factor of disease. In recent years, skin disease caused by geophilic fungi has been decreasing, while case reports of zoonoses from various animals are increasing. Outbreaks of anthropophilic T. tonsurans infection pose a problem to medical mycologists. Tinea pedis is the most common exogenous dermatomycosis in Japan. Although T. rubrum is presumed to be the dominant pathogen of this disease, T. mentagrophytes is detected more frequently from various environments, so far, the reason for this discrepancy has not been fully understood. The latest knowledge about the route of dermatophyte foot infection is as follows: (1) Dermatophyte propagules disseminated from patients may contaminate not only bath-mats but also wood floors, Japanese style mattings, concrete floors, slippers, cushions, etc., and from them adhere to healthy skin. (2) The agar stamping method can easily detect dermatophytes from the skin and the environment. (3) Propagules of T. mentagrophytes can survive for more than three months under certain conditions such as in rubber boots. (4) In order to eliminate dermatophytes gathered in socks and footwear, simple procedures (washing, bathing with hot water, or wiping with a towel) are all effective. (5) Prior application of an antifungal agent promptly eradicates dermatophyte propagules adhering to the skin from the environment. The author also mentioned the possibility of asymptomatic dermatophyte colonization, and the high prevalence of dysgeucia in oral carriers of Candida albicans.

Animals↗
PubMed1998

Improving nursing education classroom environments.

This study describes the first use of a classroom environment questionnaire with a class in nursing education. An instructor of nursing students monitored classes using such a questionnaire. The questionnaire used was the College and University Classroom Environment Inventory and it was used to obtain practical and useful information about the learning environment in two different classes. Collaborative changes were made in the classes to improve the classroom environment and consequently the learning situation. Any instructor of nursing students could use this same process with this instrument.

Adult↗
PubMed1994

Person-environment assessments in occupational therapy.

Occupational therapists have begun to recognize the importance of considering how the environment influences occupational performance. Models of person-environment fit provide a theoretical context within which occupational therapists can consider the influence of the environment on function. The challenge for occupational therapists is to select assessments that incorporate concepts of person-environment fit. However, limited awareness of appropriate environmental assessments that have undergone psychometric testing has limited their introduction into clinical practice. This paper reviews 41 environmental assessments and considers each in terms of its purpose, environmental attribute, environmental application, clinical utility, instrument development, and psychometric testing. A case example illustrates the applicability to the practice of occupational therapy.

Activities of Daily Living↗
PubMed2000

Item bias in indices measuring psychosocial work environment and health.

OBJECTIVES: The main purpose of this study was to demonstrate the relevance of testing indices concerning the psychosocial work environment by item bias or differential item functioning (DIF) analysis. Especially when the work environment for different groups is compared, this kind of construct validation is important. As exogenous variables gender, age, and occupational group were selected. METHODS: Data were taken from a cross-sectional study of Danish employees aged 19-59 years (N=5940). The study was carried out in 1990 and followed-up in 1995. RESULTS: Item bias was demonstrated in all indices when analyzed in relation to gender, age, and occupational groups of the total population. Item bias was much weaker or disappeared as the population was divided into main occupational groups and analyzed in relation to the same exogenous variables. CONCLUSIONS: For a heterogeneous group of employees, gender, age, and occupational status are significant determinants of the response pattern in relation to indices of the psychosocial work environment. It was concluded that, if the psychosocial work environment for different groups is to be compared, indices should always be tested for item bias in relation to the exogenous variables included in the final analyses. Indices should only be used if there is no item bias. If such indices cannot be constructed, it is suggested that researchers either concentrate on constructing indices that are valid in subgroups or report results based on single-item analyses.

Adult↗
PubMed2000

Living environments and older people.

The influence of care environments on patients has long been a fundamental concern for nurses. Considerations of how environments might be defined, particularly how multiple aspects of environments might impact on any individual, are complex. This article aims to unpick some of the complexities and to offer ideas on how nurses can positively influence environments, particularly in settings where older people live and are offered care.

Activities of Daily Living↗
PubMed1998

Virtual environments special needs and evaluative methods.

This paper presents an overview of the development of the Learning in Virtual Environments programme (LIVE), carried out in special education over the last four years. It is more precisely a project chronology, so that the reader can sense the historical development of the programme rather than giving emphasis to any one particular feature or breakthrough, which are covered in other papers and available through the authors. The project conception in a special school in Nottingham is followed by a description of the development of experiential and communicational virtual learning environments. These are followed, in turn, by the results of our testing programmes which show that experience gained in a virtual environment can transfer to the real world and that their use can encourage self-directed activity in students with severe learning difficulties. Also included is a discussion of the role of virtual learning environments (VLEs) in special education and of its attributes in the context of contemporary educational theory.

Activities of Daily Living↗
PubMedDate not supplied

Contrasting influence of the living environment and gender on systemic hypertension in Saudi population of Gassim, Saudi Arabia.

In a cross-sectional total population survey of Faizia East Primary Health District of Buraidah, which is divided into an "urban" and "rural" sections, casual blood pressure was recorded in 5671 subjects. 2222 (910 males) were adults (> 19 years). 3299 (1561 males) were between 3-18 years, making the paediatric/adolescent cohort of the population. The rest were below 3 years and were not included for calculations in this report. For adults, HPN was defined as > or = 140/90 mm Hg and P/A it was > or = 95th percentile for the age cohorts 3-5, 6-9, 10-12, 13-15 and 16-18 years as recommended by The Task Force for Blood Pressure Control in Children (1987). Each of the three subsets of HPN were derived from these basic definitions without modification. In the adults population, overall prevalence (S/DHPN + ISHPN + IDHPN) was 23.58% (524/2222) and gender prevalence was marginal in favour of males (25.71 vs 22.1% for males and females respectively; OR: 1.22, chi square = 3.89; p = 0.05; CI: 1.00 < OR < 1.49). By contrast, overall HPN prevalence in P/A was 10.64% (351/3299) and in all the age cohorts, girls were very significantly more hypertensive than boys. Overall figures were 13.06 vs 7.94% respectively for girls and boys; OR: 0.57; chi square = 22.65; p < 0000019; CI: 0.45 < OR < 0.73. Only in severe HPN (> or = 99th percentile) in 16-18 year age cohort did male preponderance become obvious. When the influence of the living environment was examined, in adult population (urban: 40,001; rural: 1670 subjects), for all age cohorts the rural environment which is largely inhabited by the unsophisticated Bedouins living close to their livestock, significantly predisposed to HPN as compared to the urban setting. Overall figures are 19.95 vs 32.60%, urban vs rural respectively: OR: 0.52; chi square = 40.4; p < 0.000000; CI: 0.42 < OR < 0.64. On the other hand, in the P/A population (2301 urban, 998 rural) for the age cohorts 3-5 and 6-9 years the urban environment significantly predisposed to HPN. At 10-12 years the prevalence was virtually even (12.65 vs 12.71%; OR: 0.99; p: NS). Thereafter, i.e. 13-15, 16-18 year cohorts, the rural environment became more dominant, just like the adult pattern. In other words whatever the factors in the unsophisticated Bedouin "rural" setting which predisposes to HPN does not become operative until after childhood--after 12 years. This contrasting gender and environmental influence in our study population seems unique, being reported for the first time. It may be pointing us in new direction in the elucidation of the pathogenesis of HPN and should deserve further studies.

Adolescent↗
PubMed2000

Women's work and fertility in a sub-Saharan urban setting: a social environment approach.

Data from three separate studies conducted in Maputo, Mozambique, in 1993 are used to analyse the relationship between the type of social environment in which women work and their fertility and contraceptive use. The analysis finds that women who work in more collectivized environments have fewer children and are more likely to use modern contraception than women who work in more individualized milieus and those who do not work outside the home. Most of these differences persist in multivariate tests. It is argued that collectivized work environments are most conducive to diffusion and legitimation of reproductive innovations. In contrast, individualized environments tend to isolate women and therefore may retard their acceptance of innovative fertility-related behaviour.

Adult↗
PubMed2000

Effects of a nocturnal environment perceived as warm on subsequent daytime sleep in humans.

We studied the influence of a nocturnal environment perceived as warm on the subsequent daytime sleep of healthy human subjects (20-25 years old). From 00:00 to 8:00, they were kept awake and exposed to either a thermoneutral and comfortable (CN) or a warm and uncomfortable (EW) environment, as assessed by the predicted mean vote/percentage of persons dissatisfied questionnaire (PMV/PPD). The subjects then slept from 8:00 to 14:00 in a thermoneutral environment. Sleep was scored according to the Rechtschaffen and Kales criteria. Rectal temperature was recorded from 22:00 to the end of the sleep period. Compared to CN, a significant but moderate hyperthermia (0.3-0.4 degrees C) occurred rapidly in EW, and was maintained throughout the night. This modest difference disappeared during subsequent sleep spent at thermal comfort. Exposure to a warm uncomfortable environment before bedtime significantly increased the duration (+37%) and percentage of rapid eye movement sleep (REMS). This hypnic response could be due to interactions occurring between thermoregulatory, circadian, and sleep mechanisms. It could also be ascribed to synergic actions of the neurophysiological (among others, involving the hypothalamo-pituitary-adrenal axis) and psychological (involving memory processing) processes developed when the organism faces a moderate stress.

Adult↗
PubMed2000

[Affect of heredity, disease and environment on the life-span of personage in History Book of Song Dynasty].

The data have been sorted and calculated by statistics for personages' life-span according to surname and Yin-Yang type and disease according to the cause of pattern over 793 personage from the biography of emperor families' and official in feudal times and subjects of the feudal ruler in History Book of Song Dynasty. (1) For there are some genetic diseases causing their earlier death in surname Zhao's, the average value of life-span is shorter than the other surname of Wang, Li, Zhang, Liu and Chen's. Because the average value among those five surnames are not different each other, the character of the distribution of every one's tally with neuter alleles. (2) The average value in a population on a type of mild Yin and Yang is higher than the type of Yang only, P < 0.05. (3) Disease and bad environment are the limiting factors for life. Besides, to rise the resistance ability is an important path way for increasing our life-span. The attribute of a genetic system in Yin or Yang is an objective existence. Influence on life by genetics may vary with various disease and environment, but different disease is controlled genetically. A bad environment may affect life, but neuter environment would be affected the life through attribute of a genetic system in Yin or Yang type indirectly.

Environment↗