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At least 289 records · Page 16Linked to original sources
PubMed2003

Industry-sponsored research on the potential health and environmental effects of selected brominated flame retardants.

Modern fire-fighting techniques, equipment and fire-resistant building design has lead to less destruction than in the previous centuries. However, a high fuel load in either a residence or a commercial building can overwhelm even the best firefighters or building construction, and factors affecting the fuel load have changed in recent decades. The fire load in a typical home has doubled over the last 50 years, furnishings typically include those made of petrochemicals that can behave as if containing built-in accelerant, and modern energy-efficient buildings are less able to disperse heat in the event of a fire. Flame retardant chemicals (FRs) are one means used to reduce the risk of fire. FRs are typically added or incorporated chemically into a polymer to slow or hinder the ignition or growth of a fire in low-to-moderate cost commodity polymers. One type of FR contains bromine atoms as the active moiety. The FR industry, either as individual companies or as consortia, has conducted a broad range of studies on the commercial deca-, octa- and pentabromodiphenyl oxide/ether, tetrabromobisphenol A and hexabromocyclododecane products. These five products have data in excess of the OECD Screening Informational Data Set (SIDS) and the U.S. High Production Volume (HPV) program, and sufficient data for the performance of formal EU risk assessments. The objective of this paper is to present the range of data developed by industry consortia and to provide sources for the information. We hope to facilitate further research by assembling references to industry consortia-sponsored research here.

Environment↗
PubMed1976

Environmental determination of selective significance or neutrality of amylase variants in Drosophila melanogaster.

Strains homozygous at the amylase locus were derived from a polymorphic laboratory population of Drosophila melanogaster. The Amy4,6 strain has higher enzyme activity than Amy1 strain.-Maltose has the same nutritional value as starch.- The effect of starch in pure culture depends on the yeast level. At low yeast level increasing starch increases survival, at high yeast level increasing starch increases mean dry weight. The strains do not differ in survival or mean dry weight in pure culture.--In mixed cultures at 50% input of Amy4,6 and Amy1 as larvae the percentage Amy4,6 in adults is present with increasing maltose at low yeast levels in mixed culture. The increase in percentage Amy4,6 with increasing starch must be due to selection on the amylase locus working by competition for food in the larval stage. The single locus selection coefficient is determined by the environment and can reach quite high values.--Viability selection in the presence of starch is in the direction indicated by the enzyme activities.

Amylases↗
PubMed2000

Evidence for natural selection in a fern hybrid zone.

Morphological characters, chloroplast DNA, and allozymes were used to analyze the distribution of individuals within a hybrid population of the ferns Polystichum munitum and P. imbricans in northwestern California. Microsites within the population were characterized according to soil moisture and light levels reaching the plants. In sites with low soil moisture and high light levels, all of the ferns were genetically and morphologically like P. imbricans. In contrast, ferns with the genetic and morphological identity of P. munitum predominated in moist shady sites. Intermediate sites supported very few P.munitum, a wide variety of hybrid recombinants, and a majority of ferns with P. imbricans characteristics. The pattern of variation within the population is noteworthy because of the close proximity of the habitat extremes and the long-range dispersal of fern spores. We conclude that natural selection along environmental gradients must be a major factor in determining the ecological and genetic associations within the hybrid zone. The results of this study are evaluated in the context of the fern life cycle and compared to the assumptions of models explaining the establishment and maintenance of hybrid zones, which vary in the role attributed to environmentally mediated natural selection.

Journal Article↗
PubMedDate not supplied

Comparison of the Reveal 20-hour method and the BAM culture method for the detection of Escherichia coli O157:H7 in selected foods and environmental swabs: collaborative study.

Four different food types along with environmental swabs were analyzed by the Reveal for E. coli O157:H7 test (Reveal) and the Bacteriological Analytical Manual (BAM) culture method for the presence of Escherichia coli O157:H7. Twenty-seven laboratories representing academia and private industry in the United States and Canada participated. Sample types were inoculated with E. coli O157:H7 at 2 different levels. Of the 1,095 samples and controls analyzed and confirmed, 459 were positive and 557 were negative by both methods. No statistical differences (p <0.05) were observed between the Reveal and BAM methods.

Beverages↗
PubMedDate not supplied

[Analysis of selected constitutional and environmental factors in patients with atopic dermatitis].

In 156 children and adolescents with atopic dermatitis retrospective analysis was carried out for establishing the effect of constitutional and environmental factors on the process of development and clinical course of this disease. It was demonstrated that the type of feeding during infancy was related to the beginning of the first symptoms. The onset of atopic dermatitis was earliest and most frequent in children with a history of only brief breast-feeding (up to 2 months) or fed with cow milk formulas since birth. Breast-feeding during 2-6 months delayed the onset of atopic dermatitis by about 2 months in relation to the former group. The effect of environmental factors manifested itself also as exacerbation of skin changes after contact with house dust, animal hairs, feathers and other antigens (fish food, contact with plants). At the same time positive results were observed of point tests with these allergens. A significant effect of the constitutional factor on the development of atopic dermatitis included familial occurrence of atopic diseases (mostly atopic dermatitis). Only 12.8% of the studied children had no family history of atopy.

Adolescent↗
PubMed1979

Developmental issues in cognitive mapping: the selection and utilization of environmental landmarks.

2 studies were conducted to investigate developmental differences in the ability to select and use environmental landmarks for cognitively organizing distance information from a walk. In experiment 1, second-grade, fifth-grade, and college subjects viewed a simulated walk and selected scenes that were high in potential landmark value. In experiment 2, children from the same grade levels first viewed the walk and then ranked distances among either the test scenes most frequently selected by their peers or those selected most frequently by adults. Results indicated that (a) adults and children may not spontaneously select the same features as real-world landmarks; (b) children are less capable than adults in judging the value of potential landmarks as distance cues; and (c) the ability to use environmental landmarks as cues for distance information developmentally precedes the ability to assess this potential information value.

Adult↗