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PubMed1999

Genetic diversity of archaea in deep-sea hydrothermal vent environments.

Molecular phylogenetic analysis of naturally occurring archaeal communities in deep-sea hydrothermal vent environments was carried out by PCR-mediated small subunit rRNA gene (SSU rDNA) sequencing. As determined through partial sequencing of rDNA clones amplified with archaea-specific primers, the archaeal populations in deep-sea hydrothermal vent environments showed a great genetic diversity, and most members of these populations appeared to be uncultivated and unidentified organisms. In the phylogenetic analysis, a number of rDNA sequences obtained from deep-sea hydrothermal vents were placed in deep lineages of the crenarchaeotic phylum prior to the divergence of cultivated thermophilic members of the crenarchaeota or between thermophilic members of the euryarchaeota and members of the methanogen-halophile clade. Whole cell in situ hybridization analysis suggested that some microorganisms of novel phylotypes predicted by molecular phylogenetic analysis were likely present in deep-sea hydrothermal vent environments. These findings expand our view of the genetic diversity of archaea in deep-sea hydrothermal vent environments and of the phylogenetic organization of archaea.

Adaptation, Physiological↗
PubMed2003

Genotype-environment interactions at quantitative trait loci affecting inflorescence development in Arabidopsis thaliana.

Phenotypic plasticity and genotype-environment interactions (GEI) play a prominent role in plant morphological diversity and in the potential functional capacities of plant life-history traits. The genetic basis of plasticity and GEI, however, is poorly understood in most organisms. In this report, inflorescence development patterns in Arabidopsis thaliana were examined under different, ecologically relevant photoperiod environments for two recombinant inbred mapping populations (Ler x Col and Cvi x Ler) using a combination of quantitative genetics and quantitative trait locus (QTL) mapping. Plasticity and GEI were regularly observed for the majority of 13 inflorescence traits. These observations can be attributable (at least partly) to variable effects of specific QTL. Pooled across traits, 12/44 (27.3%) and 32/62 (51.6%) of QTL exhibited significant QTL x environment interactions in the Ler x Col and Cvi x Ler lines, respectively. These interactions were attributable to changes in magnitude of effect of QTL more often than to changes in rank order (sign) of effect. Multiple QTL x environment interactions (in Cvi x Ler) clustered in two genomic regions on chromosomes 1 and 5, indicating a disproportionate contribution of these regions to the phenotypic patterns observed. High-resolution mapping will be necessary to distinguish between the alternative explanations of pleiotropy and tight linkage among multiple genes.

Arabidopsis↗
PubMed1980

Developmental stability opf Drosophila melanogaster under artificial and natural selection in constant and fluctuating environments.

Populations of Drosophila melanogaster in constant 25 degrees and fluctuating 20/29 degrees environments showed increases in developmental stability, indicated by decreases in bilateral asymmetry of sterno-pleural chaeta number. In both environments, rates of decrease in asymmetry were greater under natural selection (control lines) than under artificial stabilizing selection. Overall mean asymmetry was greater in the fluctuating environment.--There was no evidence that decreased asymmetry was due to heterozygosity, and the decline in asymmetry was not explained by the decline in chaeta number in the lines under natural selection. However, the decline was consistent with changes in total phenotypic variance and environmental variance.--The divergence between lines after 39 generations of selection was seen in differences in asymmetry and also in the genotype-environment interaction expressed in cross-culturing experiments.

Animals↗
PubMed2004

Measuring the 'obesogenic' food environment in New Zealand primary schools.

Childhood obesity is an increasing health problem in New Zealand and many other countries. Information is needed to guide interventions that reduce the 'obesogenic' (obesity-promoting) elements of school environments. The aim of this study was to identify and measure the obesogenic elements of the school environment and the canteen sales of energy-dense foods and drinks. A self-completion questionnaire was developed for assessing each school's nutrition environment and mailed to a stratified random sample of New Zealand schools. The responses from primary schools (n = 200, response rate 61%) were analysed. Only 15.5% of schools had purpose-built canteen facilities and over half ran a food service for profit (31% profit to the school, 24.5% profit for the contractors). Only 16.5% of schools had a food policy, although 91% of those rated the policy as effective or very effective. The most commonly available foods for sale were pies (79%), juice (57%) and sausage rolls (54.5%). Filled rolls were the most expensive item (mean dollars 1.79) and fruit the least expensive (mean dollars 0.47). The ratio of 'less healthy' to 'more healthy' main choices was 5.6:1, for snacks it was 9.3:1 and for drinks it was 1.4:1. In contrast, approximately 60% of respondents said that nutrition was a priority for the school. Only 50% felt there was management support for healthy food choices and only 39% agreed that mainly nutritious food was offered by the food service. 'Less healthy' choices dominated food sales by more than 2:1, with pies being the top selling item (>55000 per week). We found that the food environment was not conducive to healthy food choices for the children at New Zealand schools and that this was reflected in the high sales of relatively unhealthy foods from the school food services. Programmes that improve school food through policies, availability, prices and school ethos are urgently needed.

Beverages↗
PubMed1999

The influence of in-vitro culture versus stimulated and untreated oviductal environment on mouse embryo development and implantation.

A prospective randomised study was performed to evaluate stimulated versus natural oviductal environment in comparison with in-vitro culture for the developmental capacity of mouse embryos. Therefore, embryos of superovulated F1 hybrid CBAxC57Bl females were collected at 17, 22, 41 and 46 h after human chorionic gonadotrophin treatment and randomly divided into five groups. They were either transferred immediately to untreated pseudopregnant females, cultured in vitro for 5, 24 or 29 h before transfer, or cultured in vitro for 96 h to blastocysts. The transfers resulted in an impaired implantation (P < 0.001) and a lower numbers of living fetuses (P < 0.001) when embryos had been exposed longer to the stimulated oviductal environment. Similar results were obtained after a longer period of in-vitro culture (P < 0.05). However when embryos were flushed earlier from the superovulated mice and cultured longer in-vitro until the transfer was performed, the implantation rate was improved (P < 0.01). Blastocyst development, however, was better (P < 0.001) when embryos were flushed later. In conclusion, the stimulated oviductal environment impairs the developmental capacity of embryos in comparison with untreated pseudopregnant females. In-vitro culture is also suboptimal but better than the stimulated oviductal environment.

Animals↗
PubMedDate not supplied

Effects of in-vivo and in-vitro environments on the metabolism of the cumulus-oocyte complex and its influence on oocyte developmental capacity.

There has been an improvement in the blastocyst rates achieved following in-vitro embryo production that can largely be attributed to improved embryo culture conditions based on an increased knowledge of the in-vivo environment, as well as the metabolic needs of the embryo. Despite this, in-vitro oocyte maturation (IVM) conditions have remained largely unchanged. Within the antral follicle, numerous events affect oocyte maturation and the acquisition of developmental competency, including: interactions between somatic cells of the follicle (in particular cumulus cells) and the oocyte; the composition of follicular fluid; and the temperature and vascularity of the follicular environment. Many of these factors change with follicle size and oocyte growth. In contrast, culture conditions for IVM are based on somatic cells that often do not reflect the follicular environment, and/or have complex compositions or additives such as macromolecule supplements that are undefined in nature. Metabolites included in media such as glucose, pyruvate, oxygen and amino acids have been shown to have differential influences on oocyte maturation and competency. Manipulation of these factors and application of gained knowledge of the in-vivo environment may result in improved in-vitro oocyte maturation and overall in-vitro embryo production.

Coculture Techniques↗
PubMed1999

Power and sample size calculations in case-control studies of gene-environment interactions: comments on different approaches.

Power and sample size considerations are critical for the design of epidemiologic studies of gene-environment interactions. Hwang et al. (Am J Epidemiol 1994;140:1029-37) and Foppa and Spiegelman (Am J Epidemiol 1997;146:596-604) have presented power and sample size calculations for case-control studies of gene-environment interactions. Comparisons of calculations using these approaches and an approach for general multivariate regression models for the odds ratio previously published by Lubin and Gail (Am J Epidemiol 1990; 131:552-66) have revealed substantial differences under some scenarios. These differences are the result of a highly restrictive characterization of the null hypothesis in Hwang et al. and Foppa and Spiegelman, which results in an underestimation of sample size and overestimation of power for the test of a gene-environment interaction. A computer program to perform sample size and power calculations to detect additive or multiplicative models of gene-environment interactions using the Lubin and Gail approach will be available free of charge in the near future from the National Cancer Institute.

Case-Control Studies↗
PubMed1989

Mobility methods selected for use in home and community environments.

Efficient mobility methods are a necessity for maximum participation in home and community environments. Individuals who require the use of assistive devices for mobility are at risk for limited environmental access. Few investigations have compared the effectiveness of various mobility methods as a function of the environments in which mobility is required. Sixty-eight adults with physical disabilities who used assistive devices for independent mobility were surveyed to determine mobility methods selected for use in specific home and community environments and to determine how far they would travel outdoors before resorting to use of a motor vehicle. Results indicated that frequently individuals used more than one mobility method at home but only one method in outdoor and community environments. Individuals who used wheeled mobility methods traveled greater distances outdoors than those who walked. Implications for practice and research are discussed.

Adult↗
PubMed1994

Effects of maternal environment on mortality and growth in young Pinus sylvestris in field trials.

The same full-sib families of Scots pine (Pinus sylvestris L.) were created by artificial pollination of genetically identical grafts at three localities in Sweden at approximately 56, 59 and 64 degrees N. Two field trials were established with one-year-old plants in different years at latitude 64 degrees N. Height and survival were monitored for 4-5 years following planting. Maternal environment had significant aftereffects on the height of progeny. In both field trials, plants with the maternal parent at 59 degrees N were tallest and plants with the maternal parent at 64 degrees N were shortest. The aftereffects of maternal environment were as large in six-year-old plants as in one-year-old plants. In one field trial, maternal environment had a significant effect on mortality six years after germination but not after three years. Mortality increased with decreasing latitude of the maternal location. We conclude that the aftereffects of maternal environment are too large and too permanent to be regarded as unimportant.

Journal Article↗
PubMed1994

Adult skin wounds in the fetal environment heal with scar formation.

OBJECTIVE: This study investigated the influence of the fetal environment on the healing characteristics of adult skin. SUMMARY BACKGROUND DATA: The remarkable ability of the fetus to heal without scarring is poorly understood. The unique qualities of fetal wound healing may be caused by the fetal environment, the fetal tissues, or a combination of both. There are numerous differences between the prenatal and postnatal environments that may play a role in the unique fetal response to injury. METHODS: Full-thickness adult sheep skin was transplanted onto the backs of 60-day-gestation fetal lambs (term, 145 days of gestation). The adult skin grafts were thus perfused by fetal blood and bathed in amniotic fluid. Previous work has demonstrated that, before midgestation, fetal lambs do not reject allogenic skin grafts. Forty days later (100 days of gestation), incisional wounds were made on both the adult skin graft and the adjacent fetal skin. The wounds were harvested 14 days postwounding and analyzed by both light microscopy and immunohistochemical testing using antibodies to collagen types I, III, and VI. RESULTS: The wounds in the adult skin grafts healed with scar formation. This observation contrasts strongly with the scarless healing of the incisional fetal skin wounds. CONCLUSIONS: This study suggests that scarless fetal skin healing properties are intrinsic to fetal skin and are not primarily the result of the fetal environment.

Amniotic Fluid↗
PubMed1978

Measuring the medical school learning environment.

Medical educators' growing concern over the high level of student stress has been accompanied by a shift in their conceptualization of the problem. Student stress is increasingly seen as a problem resulting from the individual's interaction with the learning environment and not as an indication of personal deficiency. This shift has made evident the need for an instrument capable of assessing the significant dimensions of the medical school learning environment. This report describes how the Medical School Learning Environment Survey (MSLES) was developed to measure aspects of the learning environment relevant to student stress. Results of the first administration and plans for future projects using the survey are discussed.

Humans↗
PubMed1998

Organizational environment and perceptions of teaching quality in seven South Carolina family medicine residency programs.

PURPOSE: To explore the relationship between organizational environment and teaching quality in seven family medicine residency programs. METHOD: In 1995, a questionnaire on organizational environment was administered to the faculties at all seven family medicine residency programs in South Carolina. Eighty-seven percent of the faculty members participated, as did convenience samples of residents, nurses, and administrative staff. The questionnaire measured seven variables: teaching quality, job satisfaction, organizational climate, employees' autonomy, goal attainment, organizational commitment, and job-related stress. RESULTS: Residents, nurses, and administrative staff who were connected to programs at which faculty expressed high levels of job satisfaction assessed teaching quality as higher than did those at other programs. The residents' perceptions of teaching quality were positively correlated with high ratings of organizational climate and job-related stress. The staffs' ratings of goal attainment were also associated with teaching quality. Faculty satisfaction was associated with their reported employee autonomy and goal attainment. CONCLUSION: The organizational characteristics of family medicine residency programs significantly influence the perceptions of teaching quality: specifically, there perceptions are correlated with the degree to which faculty are satisfied with their work environments. In addition, residents' and staffs' perceptions of teaching quality are associated with their attitudes toward their organizations' environments.

Attitude of Health Personnel↗
PubMed1988

Modeling the outdoor environment--new perspectives and challenges.

Assessing risk from manmade and naturally occurring radionuclides in the environment has long been of primary interest in radiation protection. Early investigations and decisions relied on direct measurements of radiation in environmental media; however, these techniques were inadequate for determining exposure to humans and biota from very low levels of radiation and in predicting exposures from future releases. The Plowshare Program in 1957 investigated the use of nuclear explosives for peaceful purposes and created an immediate need for predicting the dispersion and ultimate fate of radionuclides that might be vented to the atmosphere or enter groundwater and expose man. As a result, modeling the behavior of radionuclides in the outdoor environment became a field of vigorous interest, merging disciplines of mathematics, biology and physics, among others. Environmental models and, more specifically, models predicting radiation dose from radionuclides in the environment have evolved rapidly and have increased significantly in sophistication, complexity and scope. Application of these models is commonly known as radiological assessment. This presentation examines the current status, future direction and weaknesses of radiological assessment models used in making decisions about radiation. The trend in recent years has been toward more complex models, which has not necessarily improved the accuracy of dose estimates and, in certain cases, has had the opposite effect. The presentation also discusses the future of model development, with particular emphasis on simple techniques and the expanded use of microcomputers, which will make radiological assessment models widely available for risk assessment and for practical applications such as the design of efficient monitoring programs and engineering calculations on the clean-up of contaminated soils. The screening models developed by the National Council on Radiation Protection and Measurements are offered as an example of a powerful yet simple method for demonstrating compliance with standards. Finally, the paper reviews two major areas of challenge for the future--defining uncertainty associated with radiological assessment models and the potential for converting radiological assessment models for use with nonradioactive environmental pollutants such as chemicals. Modeling radionuclides in the environment is adopting a new perspective. Future models will be less complex than their predecessors and will be adaptable to a much broader range of users. Key challenges remain in applying the techniques used for radionuclides to nonradioactive pollutants.

Air Pollutants, Radioactive↗
PubMed2001

137Cs concentration in the environment of Kaiga of south west coast of India.

This paper presents the results of 137Cs activity in soil and vegetation obtained through a carefully planned pre-operational survey for the establishment of baseline data on background radiation level and distribution of radionuclides in the environment of Kaiga, in the south west coast of India, where two nuclear power reactors of 235 MWe each are under construction. The vertical profile in soil and the seasonal variation in the activity have been studied. Nine commonly available vegetation species of Kaiga region were analyzed for their 137Cs activity, and the soil-to-plant transfer coefficients were evaluated. Measurements were made by gamma spectrometry method employing a 90 cc HpGe detector and a 3 x 3-inch well type NaI(Tl) detector. Results show significant levels of 137Cs activity in soil samples--ranging from below detection limit (BDL) to 65.4 Bq kg(-1). The mean value of activity observed in 0-5 cm soil profiles of Kaiga environs is significantly higher when compared to the reported values for other environs of India. Depth profile studies show that the 137Cs activity decreases with the increasing soil depth, and it is below detection limit for depths more than 25 cm. The mean value of effective dose commitment due to the presence of 137Cs in soil was 167.2 microSv. Vegetation samples of the region show elevated levels of 137Cs concentration. Epiphytic plants Cymbidium aloifolium (Lo.) Swartz. and Petrobryopsis tumida (Hook.) Dix. have been identified as bio-indicators to monitor the fallout of this radionuclide in the environment of Kaiga. Seasonal variation studies indicate higher fallout of this radionuclide along with rain.

Cesium Radioisotopes↗
PubMed2004

Modeling of an industrial environment: external dose calculations based on Monte Carlo simulations of photon transport.

External gamma exposures from radionuclides deposited on surfaces usually result in the major contribution to the total dose to the public living in urban-industrial environments. The aim of the paper is to give an example for a calculation of the collective and averted collective dose due to the contamination and decontamination of deposition surfaces in a complex environment based on the results of Monte Carlo simulations. The shielding effects of the structures in complex and realistic industrial environments (where productive and/or commercial activity is carried out) were computed by the use of Monte Carlo method. Several types of deposition areas (walls, roofs, windows, streets, lawn) were considered. Moreover, this paper gives a summary about the time dependence of the source strengths relative to a reference surface and a short overview about the mechanical and chemical intervention techniques which can be applied in this area. An exposure scenario was designed based on a survey of average German and Hungarian supermarkets. In the first part of the paper the air kermas per photon per unit area due to each specific deposition area contaminated by 137Cs were determined at several arbitrary locations in the whole environment relative to a reference value of 8.39 x 10(-4) pGy per gamma m(-2). The calculations provide the possibility to assess the whole contribution of a specific deposition area to the collective dose, separately. According to the current results, the roof and the paved area contribute the most part (approximately 92%) to the total dose in the first year taking into account the relative contamination of the deposition areas. When integrating over 10 or 50 y, these two surfaces remain the most important contributors as well but the ratio will increasingly be shifted in favor of the roof. The decontamination of the roof and the paved area results in about 80-90% of the total averted collective dose in each calculated time period (1, 10, 50 y).

Adolescent↗
PubMed2000

Rating the quality of the family environment in different cultures.

OBJECTIVE: To examine the extent to which clinicians from different cultures agree when rating the quality of a child's family environment and the effect of country, language, and training factors on these ratings. METHOD: Eighty-seven health professionals from Malaysia, Spain, Australia, Indonesia, the United States, Denmark, and Singapore rated 7 case vignettes using the Global Family Environment Scale. Half (54%) were psychiatrists. One quarter (26%) performed the ratings after attending a training session, the rest (n = 64, 74%) after reading a training manual. RESULTS: Overall, interrater agreement (intraclass r) was 0.84 (95% confidence interval: 0.68-0.96). There were no significant differences in agreement according to country, language, training, or professional group, although there were country differences in the ratings given to 2 vignettes. The majority of raters found the description of the anchor points (86%), training manual (95%), and case vignettes (97%) clear. CONCLUSIONS: Clinicians from different cultures seem to be able to make global ratings of the quality of the family environment that are reliable and consistent when using case vignettes. This can be achieved with little training. Global ratings of the quality of the family environment may be a useful tool in mental health research and clinical work.

Adult↗
PubMed2004

Evaluation of the built environment at a children's convalescent hospital: development of the Pediatric Quality of Life Inventory parent and staff satisfaction measures for pediatric health care facilities.

In preparation for the design, construction, and postoccupancy evaluation of a new Children's Convalescent Hospital, focus groups were conducted and measurement instruments were developed to quantify and characterize parent and staff satisfaction with the built environment of the existing pediatric health care facility, a 30-year-old, 59-bed, long-term, skilled nursing facility dedicated to the care of medically fragile children with complex chronic conditions. The measurement instruments were designed in close collaboration with parents, staff, and senior management involved with the existing and planned facility. The objectives of the study were to develop pediatric measurement instruments that measured the following: (1) parent and staff satisfaction with the built environment of the existing pediatric health care facility, (2) parent satisfaction with the health care services provided to their child, and (3) staff satisfaction with their coworker relationships. The newly developed Pediatric Quality of Life Inventory scales demonstrated internal consistency reliability (average alpha = 0.92 parent report, 0.93 staff report) and initial construct validity. As anticipated, parents and staff were not satisfied with the existing facility, providing detailed qualitative and quantitative data input to the design of the planned facility and a baseline for postoccupancy evaluation of the new facility. Consistent with the a priori hypotheses, higher parent satisfaction with the built environment structure and aesthetics was associated with higher parent satisfaction with health care services (r =.54, p <.01; r =.59, p <.01, respectively). Higher staff satisfaction with the built environment structure and aesthetics was associated with higher coworker relationship satisfaction (r =.53; p <.001; r =.51; p <.01, respectively). The implications of the findings for the architectural design and evaluation of pediatric health care facilities are discussed.

Attitude of Health Personnel↗
PubMed1997

Creating a healthy work environment in the midst of organizational change and transition.

In the midst of organizational change and transition, the need for a healthy work environment is greater than ever. Leaders may be in a position of leading staff on a journey they would rather not be on. Although there may not be a choice of destination, there are many decisions to be made along the way that will impact the health and quality of the journey. Creation of a healthy work environment does not occur overnight. It requires acknowledgment of the reality of the present environment, clear behavioral expectations and standards, systems, and structures to ensure the organizational changes are enduring and a means to assess continually the health of the work environment. Leaders have an opportunity and a responsibility to structure organizations in such a way that dignity, integrity, honesty, and compassion are preserved.

Hospitals, University↗