990 research outputs found

    Vinyl chloride: still a cause for concern.

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    Vinyl chloride (VC) is both a known carcinogen and a regulated chemical, and its production capacity has almost doubled over the last 20 years, currently 27 million tons/year worldwide. According to recent reports it is still a cause for concern. VC has been found as a degradation product of chloroethylene solvents (perchloroethylene and trichloroethylene) and in landfill gas and groundwater at concentrations up to 200 mg/m(3) and 10 mg/L, respectively. Worldwide occupational exposure to VC still seems to be high in some countries (e.g., averages of approximately 1,300 mg/m(3) until 1987 in one factory), and exposure may also be high in others where VC is not regulated. By combining the most relevant epidemiologic studies from several countries, we observed a 5-fold excess of liver cancer, primarily because of a 45-fold excess risk from angiosarcoma of the liver (ASL). The number of ASL cases reported up to the end of 1998 was 197 worldwide. The average latency for ASL is 22 years. Some studies show a small excess risk for hepatocellular carcinoma, and others suggest a possible risk of brain tumors among highly exposed workers. Lung cancer, lymphomas, or leukemia do not seem to be related to VC exposure according to recent results. The mutation spectra observed in rat and human liver tumors (ASL and/or hepatocellular carcinoma) that are associated with exposure to VC are clearly distinct from those observed in sporadic liver tumors or hepatic tumors that are associated with other exposures. In rats, the substitution mutations found at A:T base pairs in the ras and p53 genes are consistent with the promutagenic properties of the DNA adduct 1,N(6)-ethenoadenine formed from VC metabolites. Risk assessments derived from animal studies seem to overestimate the actual risk of cancer when comparing estimated and reported cases of ASL

    The Origin of Indian Corn and its Relatives.

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    315 pgIntroduction; Botanical Relationships of Maize; Previous Evidence on the Origin of Maize; Previous Theories on the Origin of Maize; New Evidence from Cytogenetic Studies; The Origin of Teosinte; The Origin of Maize; The Origin of Tripsacum; Theorhetical Phylogeny of the American Maydeae; Relationship of the American Maydeae to the Andropogoneae; Maize in Relation to Culture and Civilization; Conclusions; Literature Cite

    Parental beliefs, infant temperament, and marital quality: Associations with infant–mother and infant–father attachment.

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    The present research examined parental beliefs about the importance of the paternal caregiving role, mothers’ and fathers’ reports of infant temperament, and observed marital quality as predictors of infant-mother and infant-father attachment security, over and above the effects of parental sensitivity. Infants’ attachment security to mothers and fathers were observed in the Strange Situation at 12- and 13-months, respectively (N = 62 two-parent families). Hierarchical regression models revealed that mothers who viewed the paternal caregiving role as important were less likely to have securely attached infants, but only when infant fussiness was high. Additionally, fathers who viewed the paternal caregiving role as important were more likely to have securely attached infants, but only when infants’ fussiness or marital quality was high

    The latent structure of the adult attachment interview: Large sample evidence from the collaboration on attachment transmission synthesis

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    The Adult Attachment Interview (AAI) is a widely used measure in developmental science that assesses adults’ current states of mind regarding early attachment-related experiences with their primary caregivers. The standard system for coding the AAI recommends classifying individuals categorically as having an autonomous, dismissing, preoccupied, or unresolved attachment state of mind. However, previous factor and taxometric analyses suggest that: (a) adults’ attachment states of mind are captured by two weakly correlated factors reflecting adults’ dismissing and preoccupied states of mind and (b) individual differences on these factors are continuously rather than categorically distributed. The current study revisited these suggestions about the latent structure of AAI scales by leveraging individual participant data from 40 studies (N = 3,218), with a particular focus on the controversial observation from prior factor analytic work that indicators of preoccupied states of mind and indicators of unresolved states of mind about loss and trauma loaded on a common factor. Confirmatory factor analyses indicated that: (a) a 2-factor model with weakly correlated dismissing and preoccupied factors and (b) a 3-factor model that further distinguished unresolved from preoccupied states of mind were both compatible with the data. The preoccupied and unresolved factors in the 3-factor model were highly correlated. Taxometric analyses suggested that individual differences in dismissing, preoccupied, and unresolved states of mind were more consistent with a continuous than a categorical model. The importance of additional tests of predictive validity of the various models is emphasized

    Parents’ differential susceptibility to the effects of marital quality on sensitivity across the first year

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    The current investigation examined the differential susceptibility of parents to the effects of marital quality on changes in parenting. We predicted that parents who were high on the personality constructs Negative Affect and Constraint would be more susceptible to the effects of marital quality on their level of sensitivity. Sensitivity was assessed at 3.5 and 13 months for both mothers and fathers during a triadic interaction. Consistent with the differential susceptibility theory, results suggested that when mothers were high on Negative Affect and when fathers were high on Constraint, their marital quality was associated with changes in sensitivity. This investigation suggests that personality factors may create “vulnerabilities” in parents that make them differentially susceptible to the effects of the family environment on parentin

    Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

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    Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases
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