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PubMed2004

Behavior and pollination efficiency of Nannotrigona perilampoides (Hymenoptera: Meliponini) on greenhouse tomatoes (Lycopersicon esculentum) in subtropical México.

The acclimation, foraging behavior, and pollination efficiency of stingless bees of the species Nannotrigona perilampoides Cresson were evaluated in tomato (Lycopersicon esculentum Mill.) plants cultivated in two greenhouses. The greenhouses were divided into three areas of 16 m2, and one of the following treatments was used for pollination: stingless bees (SB), mechanical vibration (MV), and no pollination (NP). Observations were conducted once a week from 0800 to 1600 hours during 2 mo. The acclimation of the bees to the greenhouses was estimated by the number of bees that did not return to the hive (lost bees) and by comparing the population of the colonies (brood and adults). The foraging activity of the bees across the day was evaluated by comparing the number of foragers per hour. The influence of environmental variables on the foraging activity was also analyzed. The pollination efficiency was compared among treatments through the percentage of fruit set, weight of individual fruit, kilograms of fruit produced per square meter, and the number of seed per fruit. The bees started foraging on the flowers approximately 7 d after the colonies were introduced to the greenhouse. There was a decline in the population of the colonies across the experiment, but colonies did not die out. Correlations of environmental variables with the foraging activity of the bees showed that none of them had a significant influence on pollen foraging. However, water collection was positively correlated with the temperature and negatively correlated with the humidity inside the greenhouse. The estimation of the pollination efficiency per treatment showed that there were significant differences in fruit set in SB (83 +/- 4.2) and MV (78.5 +/- 6.4) compared with NP (52.6 +/- 7.6). However, the average weight of the fruit was similar for the three treatments (65 g). There were significant differences for seed number in SB (200 +/- 15.3) and MV (232 +/- 21.4) compared with NP (120 +/- 16.6). The productivity in kilograms of fruit per square meter was higher in SB (5.72 +/- 0.61) and MV (5.66 +/- 0.58 kg) compared with NP (3.34 +/- 0.72). The number of seed was positively correlated with the weight of the fruit. We conclude that the use of Nannotrigona testaceicornis Rondani, for pollinating greenhouse tomatoes in tropical climates, could be an alternative to the use of highly defensive African-derived Apis mellifera or non-native bumble bees (Bombus spp.). However, more research is needed to evaluate the cost/benefit on large-scale greenhouse pollination using N. perilampoides Cresson against other bee species and pollination methods.

Agriculture↗
PubMed2006

Examining communication repairs of 2 young children with autism spectrum disorder: the influence of the environment.

PURPOSE: The purpose of this study was to examine the repair strategies of 2 young children with autism spectrum disorder from an environmental rather than a developmental perspective. METHOD: A scripted protocol that included opportunities for requests and repair was followed. The environmental variables investigated were activity type (e.g., puzzle, shapes, book) and breakdown type (i.e., request for clarification, wrong response, and ignore). The sessions were videotaped, and each child's behavior was coded. RESULTS: The results revealed that (a) both participants repaired the majority (70%) of their unsuccessful initial requests and (b) the repair strategies varied across children, activities, and breakdowns. CONCLUSIONS: The findings of this study suggest that the 2 young children with autism and limited expressive language discriminated among environmental variables (i.e., type of activity and type of breakdown). The participants modified their repair topographies to correspond to changes in the environment. The findings from this study offer ways to enhance assessment and intervention of early communication. Implications for future research and practice are discussed.

Autistic Disorder↗
PubMed1996

Study on the feasibility of delineating mosquitogenic conditions in and around Delhi using Indian Remote Sensing Satellite data.

A feasibility study to identify mosquitogenic conditions in six study sites in and around Delhi (Bhalaswa lake, Nazafgarh drain, Seelampur lake, Sanjay lake, Okhla barrage and Hindon barrage) using Indian Remote Sensing Satellites was carried out. The water bodies with marshy areas, vegetation and human settlements were considered as environmental variables responsible for mosquitogenic conditions. Multidate IRS 1A and B, LISS-II satellite data were collected and analysed on Vax 11/780 computers. False colour composite (FCC) images were generated and land cover assessed using supervised classification based on ground truth training sets. Ground truth validation of satellite data was done on satellite pass dates. Concurrent monitoring of larval and adult mosquito density was performed by selecting sub-sites in each study site. The results indicate that mosquitogenic conditions can be identified (with limitation of resolution, i.e. 36.5 m) using FCC images and these images can be used as base maps of study sites. Characterization of study sites based on land cover was done from the view point of mosquitogenic conditions. Spatial changes in mosquito density vis-a-vis changes in environmental variables revealed positive correlation with water bodies and vegetation in some study sites.

Animals↗
PubMedDate not supplied

Abundance of terrestrial gymnamoebae at a northeastern U. S. site: a four-year study, including the El Niño winter of 1997-1998.

The abundance, sizes, and when appropriate, diversity of gymnamoebae were documented at approximately monthly intervals for four years (1995-1998) at a grassy, terrestrial site slightly upslope from a freshwater pond. Soil samples were analyzed for viable gymnamoebae using a standard laboratory culturing protocol. The mean density of gymnamoebae based on the total data set was ca. 1,600/g (s.e.+/-190). Minimum densities of gymnamoebae (156/g) occurred in January 1995, and a maximum for the sampling period (5,838/g) occurred in July 1997, when a rainy period followed an extended period of drought. Among the environmental variables monitored (precipitation, soil moisture, organic content, and temperature) only precipitation correlated significantly with abundance of gymnamoebae (r = 0.34, p = 0.02). During the mild, moist El Niño winter of 1997-1998, a larger than usual number of gymnamoebae was recorded at the site (approximately 3,800/g) compared to a mean density of approximately 900/g for comparable periods in preceding years. The mean sizes were also larger. Since gymnamoebae are increasingly recognized as major members of soil microbial communities enhancing soil fertility through nutrient mineralization, it is important to document environmental variables that influence their abundance and activity in terrestrial ecosystems.

Amoebida↗
PubMedDate not supplied

[Risk factors for Helicobacter pylori infection in children].

OBJECTIVE: To establish the seroprevalence of Helicobacter pylori infection in children and to identify risk factors for seropositivity.\par METHODS: A cross-sectional study established the seroprevalence of infection by Helicobacter pylori and afterwards a comparative study was performed amongst seropositive and seronegative children. A group of 228 children were cared for at the outpatient clinic of Instituto Materno Infantil de Pernambuco, from May to July 1999. Age, sex, indicators of environmental, social and economic conditions, health and nutritional status as well as children living in contact with dwellers with history of gastrointestinal pain or peptic disease were evaluated. All data was obtained through an interview with children's parents or caretakers. Nutritional status was evaluated by anthropometric index. \par RESULTS: Seroprevalence of infection caused by Helicobacter pylori was found in 32% (95% CI 26% - 38%); 25.8% (95% CI 17.8% - 33.8%) in preschool children and 39.4% (95% CI 30.4% - 48.4%) in school age children. Analysis of environmental variables demonstrated higher frequency of seropositivity in children living in houses without toilets or sanitary flush toilet facilities (p = 0.008), overcrowded (p = 0.05), lower family income (p = 0.03) and poor maternal education (p = 0.002). There were no statistically significant differences between the groups regarding health indicators, anthropometric indexes and children living with dwellers with history of gastritis or peptic ulcer.\par CONCLUSION: Seroprevalence of Helicobacter pylori infection was high in the studied population, being even higher among the school age group. A positive association between seropositivity and less favorable environmental variables was detected.

Brazil↗
PubMed1976

A family study of coarctation of the aorta.

Families of 100 patients with coarctation of the aorta and 50 controls for age, sex, and social status were studied to assess the influence of genetic and environmental variables in the aetiology. A tendency to familial aggregation of the condition and other congenital heart defects compatible with multifactorial inheritance was discerned. Recurrence risk for sibs is approximately 1 in 200 for coarctation of the aorta, and 1% for any form of congenital heart defect. The heritability of coarctation is estimated at 58%. The tendency for other non-cardiac defects to occur in the patients with coarctation does not appear in their sibs and is not so pronounced as in some other congenital heart conditions. Of the several environmental variables examined, there was no definitive association with any other than season of birth, which implies a possible association with maternal infection; there is also a suggestion of a paternal age effect, but these require investigation in a prospective survey.

Abnormalities, Multiple↗
PubMed1991

Urinary catecholamines, plasma insulin and environmental factors in relation to body fat distribution.

The relationship of body fat distribution to insulin and the catecholamines, hormones that affect lipolysis differentially by fat site, was examined within an environmental context, including factors of medication use, physical activity, dietary intake, educational attainment, and age. Four cross-sectional body fat areas (cm2) were determined by three computed tomography (CT) scans (subcutaneous chest fat at the level of the nipples, subcutaneous and intra-abdominal fat at the level of the umbilicus, and subcutaneous left mid-thigh fat) in 191 second-generation Japanese-American men aged 45-74 years. The site-specific fat measurements were first examined in relation to use of beta-adrenergic antagonists, then to fasting plasma insulin and C-peptide levels and to urinary epinephrine and norepinephrine levels from a 24-h urine collection made during usual daily activities. Greater fat stores in the intra-abdominal area, even after adjustment for body mass index (BMI, weight/height2) and presence of coronary heart disease, were found to be related to use of beta-adrenergic antagonists. In men taking no adrenergic antagonists (n = 157), after adjustment for BMI, truncal fat measurements of the chest (partial r = -0.16, P less than 0.05) and intra-abdominal area (partial r = -0.21, P less than 0.05) were found to be inversely related to epinephrine, and intra-abdominal fat (partial r = 0.25, P less than 0.01) alone was directly related to fasting plasma insulin. With respect to other environmental variables, the significant inverse relationship of intra-abdominal fat (adjusted for BMI) with physical activity (partial r = -0.17, P less than 0.05) and the significant difference in intra-abdominal fat by educational attainment (college 102.3 +/- 5.7 vs no college 115.7 +/- 6.1 cm2, P = 0.03) became non-significant with adjustment, using multiple regression analysis, for insulin in the case of physical activity and epinephrine in the case of educational attainment. Thus, intra-abdominal fat showed a unique set of relationships to metabolic parameters which could be further related to certain environmental variables.

Adipose Tissue↗
PubMed1992

Effects of environmental factors on maxillofacial elastomers: Part III--Physical properties.

The physical properties of four currently used and two recently introduced maxillofacial prosthetic materials were evaluated after the materials were subjected to the following seven environmental variables: natural weathering, normal aging, two types of adhesives, two types of cleaning agents and cosmetics. Ultimate tensile strength, percent elongation, tear strength, and Shore A hardness were evaluated. The physical properties recorded for the currently used materials were consistent with previous studies. Although the properties of the recently introduced materials were similar to those currently in use, one of the new materials, A-2186, showed high strength values, although it was one of the softest materials tested. Unfortunately, this new material lost these advantageous characteristics as it was weakened and made harder by most of the tested environmental variables.

1-Propanol↗
PubMed1999

Distribution of native legumes (Leguminoseae) in frequently burned longleaf pine (Pinaceae)-wiregrass (Poaceae) ecosystems.

Legume species distribution and abundance and selected environmental variables were quantified across a complex gradient (varying in both water-holding capacity and fertility) for frequently burned longleaf pine (Pinus palustris)-wiregrass (Aristida stricta) ecosystems. Legumes were present in all months; however, abundance peaked in June and was minimal after killing frosts in October. Legume species were prominent in the flora (43 species encountered) ubiquitous (94% of 2-m(2) subplots had at least one legume species), and abundant (nearly 120 000 stems/ha). Although most species were widely distributed throughout the gradient, Lespedeza angustifolia was distinctly associated with the more hydric end of the gradient, while both Petalostemon pinnatum and Galactia microphylla were located in the more xeric extreme. The percentage variation in species that could be accounted for by environmental variation was low (27%). Of the variation that could be accounted for, a number of environmental variables were important, including soil moisture, pine basal area (i.e., light), and bivalent base cations (e.g., Ca(2+)). Although gradients in resource availability among sites did not affect the distribution of species or abundance of legumes strongly, variation in resources are likely to regulate N(2)-fixation rates of the various native legume species, and thereby affect ecological functions such as maintenance of N capital and productivity.

Journal Article↗
PubMed2001

Mercury content in roach (Rutilus rutilus L.) in circumneutral lakes--effects of catchment area and water chemistry.

The environmental influence on the mercury content in roach (Rutilus rutilus L.) is investigated using partial least square regression on 46 environmental variables describing the land use in the catchment area, various catchment area and lake characteristics, lake water chemistry, and fish stock. The Hg content in the fish from the 78 investigated circumneutral lakes is heavily influenced by the land use in their surroundings. The boreal forest lakes possessed the highest Hg levels in roach, whereas fish from lakes surrounded by arable land had lower levels. The Hg levels also showed a negative relationship to the amount of dissolved ions and the total amount of nutrients in lake water. Lake pH did not have any significant influence on the Hg content in roach in these non-acidified lakes. The Hg levels in lakes influenced by large amounts of wetland were less well explained by the presently investigated environmental variables, which implies that the Hg burden in fish from this kind of lake is governed by other factors.

Animals↗
PubMed2000

Resource allocation between reproductive phases: the importance of thermal conditions in determining the cost of incubation.

Changes in the resources allocated to particular stages of reproduction are expected to influence allocation to, and performance in, subsequent reproductive stages. Experimental manipulation of individual investment patterns provides important evidence that such physiological trade-offs occur, and can highlight the key environmental variables that influence reproductive costs. By temporarily altering the thermal properties of starling nests, we reduced the energetic demand of first-clutch incubation, and examined the effect of this manipulation on performance during the same and the subsequent reproductive attempts. Compared with controls, starlings investing less in incubation were more successful in fledging young, and were more likely to hatch all their eggs if a subsequent reproductive attempt was made. Our results show that incubation demands can limit reproductive success, and that resources saved during incubation can be reallocated to later stages of the same reproductive attempt and to future reproductive attempts. This study also shows that small changes in thermal environment can affect breeding success by altering the energetic demands imposed on incubating parents, independently of the effect of temperature on other environmental variables such as food supply.

Animals↗
PubMed1998

Effects of light intensity and air velocity on air temperature, water vapor pressure, and CO2 concentration inside a plant canopy under an artificial lighting condition.

In order to characterize environmental variables inside a plant canopy under artificial lighting in the CELSS, we investigated the effects of light intensity and air velocity on air temperature, water vapor pressure, and CO2 concentration inside a plant canopy. Under a PPF of 500 micromoles m-2 s-1, air temperature was 2-3 degrees C higher, water vapor pressure was 0.6 kPa higher, and CO2 concentration was 25-35 micromoles mol-1 lower at heights ranging from 0 to 30 mm below the canopy than at a height 60 mm above the canopy. Increasing the PPF increased air temperature and water vapor pressure and decreased CO2 concentration inside the canopy. The air temperature was lower and the CO2 concentration was higher inside the canopy at an air velocity of 0.3 m s-1 than at an air velocity of 0.1 m s-1. The environmental variables inside the canopy under a high light intensity were characterized by higher air temperature, higher vapor pressure, and lower CO2 concentration than those outside the canopy.

Air Conditioning↗
PubMed1989

Genetic heritability and common environmental components of resting and stressed blood pressures, lipids, and body mass index in Utah pedigrees and twins.

The relative contributions of genes and shared environment to cardiovascular risk factors were studied in twins and pedigrees in 1983-1985. Sitting, standing, isometric hand grip, bicycling, and mentally stressed (serial subtraction) blood pressures were obtained from 146 male monozygous twins, 162 male dizygous twins, and 1,102 healthy adults in 67 Utah pedigrees. Fasting total plasma cholesterol, triglycerides, high density lipoprotein cholesterol (HDL), and body mass index were also measured. Heritability was estimated before and after adjusting for 12 environmental variables (measures of socioeconomic status; personality types; exercise levels; use of tobacco, alcohol, coffee, etc.) by using age-adjusted twin intraclass correlations. These heritabilities were compared with those obtained from a variance components analysis of the pedigree data separating genetic and common household effects. Sitting and standing blood pressure heritability estimates were much higher from twin than from pedigree data (39-63% in twins vs. 16-22% in pedigrees), as were those for cholesterol and triglycerides (65 and 75% from twins vs. 42 and 37% from pedigrees) and body mass index (51 vs. 21%). Estimates were similar for heritability of HDL cholesterol (51 vs. 45%). Most of the stressed blood pressure heritabilities were similar to sitting blood pressure estimates. No common household effect (except for adjusted HDL cholesterol (24%), p less than 0.01) was statistically significant for the lipids, blood pressures, or body mass index. Environmental variables correlated much better in monozygous twins and spouses than in dizygous twins, brothers, or sisters. Spouse correlations for lipids, blood pressures, and body mass index were low, with a maximum of 0.12 (p less than 0.05) for HDL cholesterol. We conclude that genes contribute much more than shared environment to the well-recognized familial correlation of blood pressures, lipids, and body mass index.

Adult↗
PubMed2001

Epidemiological and ecological characteristics of past dengue virus infection in Santa Clara, Peru.

To determine risk factors associated with dengue (DEN) virus infection among residents of Santa Clara, Peru, a rural Amazonian village near Iquitos, a cross-sectional serological, epidemiological and environmental survey was conducted. Demographic, social and behavioural information was obtained by standardized questionnaire from 1225 Santa Clara residents (61.3%) aged 5 years or older. Additional data were obtained on the environmental variables and immature mosquito species and abundance surrounding each household (n = 248). Sera that had been collected previously by the Peruvian Ministry of Health from residents were tested by an enzyme-linked immunosorbent assay (ELISA) for DEN virus IgG antibody. Antibody identity was verified as DEN by plaque reduction neutralization test. Data on individuals were analysed by univariate and multivariable methods, and independent sample t-tests. Spatial clustering was evaluated by comparing distances among DEN positive households. Overall, antibody prevalence was 29.4 % and more than doubled from the youngest to the oldest age groups, but did not differ by sex. Curiously, length of residence in Santa Clara was negatively associated with DEN virus antibodies. More frequent travel to Iquitos was positively associated with seroprevalence. Residents who obtained water from a river source rather than a local well also had significantly higher antibody prevalence. None of the environmental variables measured at each household corresponded to the patterns of antibody distribution. Of the larval mosquitoes found around residences, all were determined to be species other than Aedes. No evidence of spatial autocorrelation among antibody-positive households was detected. These results strongly suggested that recent DEN virus transmission did not occur in the village and that most infections of residents of this rural village were acquired while visiting the city of Iquitos.

Adolescent↗
PubMed2004

Sampling design for an integrated socioeconomic and ecological survey by using satellite remote sensing and ordination.

Environmental variability is an important risk factor in rural agricultural communities. Testing models requires empirical sampling that generates data that are representative in both economic and ecological domains. Detrended correspondence analysis of satellite remote sensing data were used to design an effective low-cost sampling protocol for a field study to create an integrated socioeconomic and ecological database when no prior information on ecology of the survey area existed. We stratified the sample for the selection of tambons from various preselected provinces in Thailand based on factor analysis of spectral land-cover classes derived from satellite data. We conducted the survey for the sampled villages in the chosen tambons. The resulting data capture interesting variations in soil productivity and in the timing of good and bad years, which a purely random sample would likely have missed. Thus, this database will allow tests of hypotheses concerning the effect of credit on productivity, the sharing of idiosyncratic risks, and the economic influence of environmental variability.

Agriculture↗
PubMed2003

[Respiratory illnesses in children younger than 5 years of age in southern Brazil: the influence of the home environment].

OBJECTIVE: To determine the prevalence of acute lower respiratory tract infections and the risk factors associated with living conditions among children up to 5 years of age in the city of Rio Grande, in the state of Rio Grande do Sul, Brazil. METHODS: A population-based cross-sectional study was carried out with 775 children. A standardized questionnaire was administered to the mother or other caregiver at the child's home in order to collect information on housing conditions, socioeconomic status, and smoking in the home. Additional variables examined included nutritional status, duration of breast-feeding, prenatal care, and utilization of health care services. Environmental variables were analyzed individually and were also grouped together in an "environmental score" that encompassed 10 variables: type of house construction, type of floor, home heating system, type of stove, dog in the child's room, dog in the house, cat in the child's room, cat in the house, number of people per room, and maternal smoking. The grouped environmental score ranged from 0 (best) to 10 (worst). The analysis included two stages: a bivariate stage, in which the prevalence ratio was calculated for each risk factor, and a multivariate stage, with logistic regression. RESULTS: The overall prevalence of acute lower respiratory tract infections was 23.9%. The main risk factors identified were: environmental score >/= 3 points, maternal schooling < 5 years, monthly family income < US$ 200, four or more people sharing the child's bedroom, and maternal smoking. Maternal age > or = 30 years was found to protect against the development of respiratory illness. CONCLUSIONS: Specific programs need to be implemented to control acute respiratory illnesses in the population studied. In future studies with this population, the environmental score that we developed could be used in place of the complete set of environmental variables that we tested. This environmental score should be applied in other contexts so as to determine its external validity.

Adolescent↗
PubMed2002

Social environment, ethnicity and schizophrenia. A case-control study.

BACKGROUND: There is accumulating evidence that genetic and neurodevelopmental factors cannot solely account for the pathogenesis of schizophrenia. In view of the reportedly increased incidence of schizophrenia among the African-Caribbean population in Britain, we sought to establish the socio-environmental influences which distinguished African-Caribbean patients from white British and Asian patients with schizophrenia, as well as from normal population controls of the same community. METHOD: A matched case-control study was conducted in London between 1991 and 1993. Inclusion criteria for patients was a first onset psychosis between the ages of 18 and 64. Symptoms were recorded using the Present State Examination (PSE), and a research diagnosis of schizophrenia was made using the CATEGO program. Comparisons were made on a range of demographic and socio-environmental measures between patients (n = 100: 38 African-Caribbean, 38 white and 24 Asian) and the same number of normal controls. RESULTS: Three socio-environmental variables differentiated the African-Caribbean cases from their peers and their normal controls: unemployment, living alone and a long period of separation from either or both parents as a minor. Though all patients were much more likely than controls to be unemployed at first contact with the services (odds ratio 5.5, 95 % CI 2.59, 11.68), the odds ratio was highest among African-Caribbeans, and further conditional logistic regression analysis demonstrated that unemployment was significantly associated with the high rate of caseness among African-Caribbeans. However, the direction of cause and effect cannot be determined from this type of study. Despite the fact that African-Caribbean cases were more likely than their peers and same group controls to live alone (p < 0.05), this did not achieve significance using Fisher's Exact Test. Separation from both parents in childhood distinguished African-Caribbean cases from their controls and from cases and controls of the other ethnic groups (odds ratio 5.0, 95 % CI 1.09, 22.82). This event cannot be attributed to the premorbid manifestations of schizophrenia, nor to psychoses in the parents, and hence is a possible explanatory factor for the high incidence of schizophrenia among African-Caribbeans in Britain. CONCLUSIONS: These findings indicate that unemployment and early separation from both parents distinguish African-Caribbeans diagnosed with schizophrenia from their counterparts of other ethnic groups as well as their normal peers, and imply that more attention needs to be focussed on socio-environmental variables in schizophrenia research.

Adult↗
PubMed2000

Reducing level of handicap in traumatic brain injury: an environmentally based model of treatment.

A treatment model is described that has as its primary focus reducing the level of handicap of individuals with traumatic brain injury (TBI) by addressing the interaction between critical environmental variables and areas of deficit. The model focuses on two primary environmental variables-degree of distraction tolerated and degree of structure required by each individual to function optimally. These variables are systematically addressed in treatment through environmental simulations within the clinic. An outcome measurement system (Pate Environmentally Relevant Program Outcome System [PERPOS]) is presented that quantifies the level of handicap throughout treatment and at discharge as a function of the interplay between deficit and environment. Data are provided that validate the PERPOS scores through comparison with qualitative descriptors of day-to-day functioning in several domains. Outcome data indicate the participants in this treatment model made significant gains with regard to reduction of handicap.

Activities of Daily Living↗