Environmental Factors In Development Research Articles

Recent Developments in Human Behavioral Genetics: Past Accomplishments and Future Directions

The field of behavioral genetics has enormous potential to uncover both genetic and environmental influences on normal and deviant behavior. Behavioral-genetic methods are based on a solid foundation of theories and methods that successfully have delineated components of complex traits in plants and animals. New resources are now available to dissect the genetic component of these complex traits. As specific genes are identified, we can begin to explore how these interact with environmental factors in development. How we interpret such findings, how we ask new questions, how we celebrate the knowledge, and how we use or misuse this knowledge are all important considerations. These issues are pervasive in all areas of human research, and they are especially salient in human behavioral genetics.

The Pediatrician and Cancer Prevention-Reply

Dr Donnelly suggests that breast-feeding might contribute a protective effect against development of childhood cancer. The scope of the Editorial1precluded an exhaustive critical discussion of a number of practices, including breast-feeding, that might prevent pediatric neoplastic diseases. That breast-feeding per se decreases the risk for all childhood cancers is not firmly established in the literature. Dr Donnelly cites two epidemiologic studies that support this beneficial effect, but these retrospective reports were weakened by small sample size, limited geographical area, and questions about maternal recall bias regarding duration and exclusiveness of breast-feeding.2,3In a study to evaluate a general-purpose epidemiologic questionnaire of possible environmental factors in development of childhood cancer, Schwartzbaum et al4 found an association (P=.04) between duration of breast-feeding and risk for development of childhood Hodgkin's disease; however, this study also pointed out the limited value of these types of survey instruments for identification of

Therapeutic Models of Psychopathology: Part I: Introduction, Overview of the Model, and Personality Organization

Part I of this paper introduces an integrated model of psychopathology that may be used as a guide for formulating a more specific model for patients in psychotherapy. This model considers the influence of biological and environmental factors in development, as well as the influence of the current environment on the psychological structure of the adult. It is compatible with a broader biological context and with current scientific thinking about the functioning of the human mind. Key principles in the development and functioning of the psychological organization of the individual are introduced. The central concept of Psychological Organization and the major dimensions of motivation, models of self and other, and information processing are discussed in detail.

Metaphors and the privileging of causes

With regard to the theoretical place of environmental factors in development, three approaches to evolution and development can be distinguished. One is the neo-Darwinist approach in which ‘genetic programs’ are central. The other two present themselves as alternatives to the gene-centrism in present-day biology. I discuss pairwise similarities and differences between the three approaches. Goodwin's approach differs from neo-Darwinism in its favoured types of causes, but shares the internalist perspective on embryological development. The ‘constructionist’ alternative proposes to enlarge the developmental system to include external factors, and shares with neo-Darwinism the emphasis on contingent causes. Thus there is neither a grand dichotomy in biology, between neo-Darwinism and its alternative, nor a grand trichotomy. Different purposes make different approaches useful. I conclude by arguing that environmental influences should have a more prominent place in developmental biology.

Conference summary: diet as an environmental factor in development of insulin-dependent diabetes mellitus.

An international symposium on diet as an environmental factor in development of insulin-dependent diabetes mellitus (IDDM) was held in Ottawa, Ont., Canada, September 1989. Several environmental factors such as viruses and chemicals, as well as diet modifications per se, were reviewed in both human and animal diabetes. Although the pathophysiology in the BB rat and nonobese diabetic (NOD) mouse may have different immunological mechanisms, both these animal syndromes of spontaneous IDDM are markedly affected by diet. In them, cereal-based rodent diets are the most diabetogenic and hydrolyzed casein-based purified diets are least diabetogenic. In two different NOD mouse colonies, diabetogenicity of cereal-based diets can be markedly decreased by extracting the diet with chloroform-methanol or water, reflecting either the different composition of the diets used in each colony or the chemical extraction and (or) alteration of certain diabetogenic agents. Thus, dietary lipids can be potent immune system modulators in several systems and the role of chloroform-methanol soluble agents in initiation and (or) promotion of the disease process is being studied. Attention was focused on protein sources previously identified by some groups as diabetogenic such as skim milk powder and wheat products, both of which can be found in natural ingredient rodent feeds. Circulating antibodies to dietary antigens such as bovine serum albumin and (crude) wheat gliadin may be elevated in diabetes-prone rodents and newly diagnosed patients, but their relationship to the pathogenesis of IDDM remains to be established. Because diet components can clearly influence the expression of the diabetic syndromes in the BB rat and NOD mouse, it will be crucial to identify the chemical nature of such components as a first step in understanding their mode of action.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of environmental factors in development of hyperbaric bradycardia.

Bradycardia has been observed in animals and humans upon exposure to various hyperbaric environments. However, the relative contribution of ambient pressure, gas density, inert gas species, and inspired O2 tension has not been defined. By means of cutaneous ECG leads, the heart rates of unanesthetized rats were recorded and compared in 11 separate thermo-neutral environments. Ambient pressures applied were 1, 3, and 10 ATA, O2 partial pressure PO2 ranged from 140 to 1,590 Torr, and gas densities were varied from 0.40 to 11.45 g/l, utilizing either N2-O2 or He-O2 mixtures. The exposure heart rates were averaged over a 30-min period and compared with a preceding control value obtained in 1 ATA normoxic He or N2. Significant bradycardia was associated with hyperoxia in environments containing either He or N2, with a magnitude proportional to log PO2. On the other hand, under normoxic conditions bradycardia was not observed despite the similar density, pressure, and inert gas components. It is concluded that hyperoxia is the most important variable of those considered in the development of hyperbaric bradycardia.

The interaction of genetic and environmental factors in development

Journal of Experimental ZoologyVolume 46, Issue 2 p. 181-244 Article The interaction of genetic and environmental factors in development Charles R. Plunkett, Charles R. Plunkett Department of Zoölogy, Columbia UniversitySearch for more papers by this author Charles R. Plunkett, Charles R. Plunkett Department of Zoölogy, Columbia UniversitySearch for more papers by this author First published: October 1926 https://doi.org/10.1002/jez.1400460204Citations: 53AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume46, Issue2October 1926Pages 181-244 RelatedInformation