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  • 1
    Digitale Medien
    Digitale Medien
    Nest plundering allomones of the fire beeTrigona (Oxytrigona) mellicolor (1988)
    Springer
    Journal of chemical ecology 14 (1988), S. 495-501 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Fire bee ; Trigona (Oxtrigona) mellicolor ; Trigona (Oxtrigona) tataira ; honeybee ; Apis mellifera ; Hymenoptera ; Apidae ; mandibular gland secretion ; allomone ; nest plundering ; diketones ; (E)-3-heptene-2,5-dione ; (E)-3-nonene-2,5-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Ten volatile compounds derived from the cephalic glands of the fire beeTrigona (Oxytrigona)mellicolor were bioassayed for possible allomonal activities facilitating nest plundering. Two diketones, (E)-3-heptene-2,5-dione and (E)-3-nonene-2,5-dione, caused the honeybeeApis mellifera to display avoidance behavior and reduced defensive behavior. These diketones are produced in relatively large quantities in fire-bee cephalic glands.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01013901
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  • 2
    Digitale Medien
    Digitale Medien
    Evidence that Childhood Acute Lymphoblastic Leukemia is Associated with an Infectious Agent Linked to Hygiene Conditions (1998)
    Springer
    Cancer causes & control 9 (1998), S. 285-298 
    Details
    ISSN: 1573-7225
    Schlagwort(e): Acute lymphoblastic leukemia ; hepatitis A virus ; hygiene ; Japan ; socioeconomic status ; United States
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objectives: The incidence of acute lymphoblastic leukemia (ALL) in children has shown temporal and geographic variation during the 20th century, with higher rates in developed nations appearing in the first half of the century, but with persisting low rates in developing nations. We sought to assess the relation of childhood ALL with hygiene conditions, an aspect of socioeconomic development affecting rates of exposure to infectious agents. Methods: Infection patterns for hepatitis A virus (HAV), an agent with a fecal-oral route of transmission, were used to indicate hygiene conditions in different populations, with emphasis on instructive United States and Japanese data. A catalytic model was fit to these data, estimating the HAV force of infection and age-specific seroprevalence rates over time. These analyses were used to assess the temporal relationship of changes in HAV infection rates to changes in childhood leukemia mortality and incidence rates. Results: We observed an inverse relationship between HAV infection prevalence and rates of childhood leukemia. Further, decreases in the HAV force of infection in the United States and Japan appear to have preceded increases in childhood leukemia rates. We describe a model based on a putative leukemia-inducing agent with a change in infection rate over time correlated with that of HAV that describes well the temporal trends in childhood leukemia rates for White children in the US and for Japanese children. Conclusion: The data suggest that improved public hygiene conditions, as measured by decreased prevalence of HAV infection, are associated with higher childhood ALL incidence rates. The model that we present supports the plausibility of the hypothesis that decreased childhood exposure to a leukemia-inducing agent associated with hygiene conditions leads to higher rates of ALL in children by increasing the frequency of in utero transmission caused by primary infection during pregnancy (or by increasing the number of individuals infected in early infancy because of lack of protective maternal antibodies). Cancer causes and Control 1998, 9, 285-298
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008873103921
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  • 3
    Digitale Medien
    Digitale Medien
    Physical activity and breast cancer risk in the College Alumni Health Study (United States) (1998)
    Springer
    Cancer causes & control 9 (1998), S. 433-439 
    Details
    ISSN: 1573-7225
    Schlagwort(e): Body mass ; breast cancer ; menopause ; physical activity ; United States ; women
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objectives: It is unclear whether physical activity is associated with a reduced risk of breast cancer. Some studies also suggest different effects between pre- and postmenopausal women, and lean and heavy women. Methods: We followed 1,566 University of Pennsylvania alumnae (mean age, 45.5 years), initially free of breast cancer, from 1962 until 1993. Physical activity at baseline was assessed by asking women about stairs climbed, blocks walked, and sports played. We estimated energy expenditure and categorized women into approximate thirds (〈 500, 500-999, 1,000+ kcal/wk). We identified 109 breast cancer cases during 35,365 person-years from follow-up questionnaires or from death certificates. Results: After adjustment for age and body mass index (BMI) (kg/m2), the relative risk (RR) of breast cancer was 0.92 (95 percent confidence interval [CI]=0.58-1.45) among women expending 500-999 kcal/wk and 0.73 (CI=0.46-1.14) for those expending 1,000+ kcal/wk, compared with women expending 〈 500 kcal/wk (P trend=0.17). This association was modified by menopausal status, but not BMI. For postmenopausal women, corresponding RRs were 0.95 (CI=0.58-1.57) and 0.49 (CI=0.28-0.86), respectively (P trend=0.015). Increased physical activity in premenopausal women was not significantly associated with decreased risk of breast cancer. Conclusions: These data support an inverse association between physical activity and breast cancer among postmenopausal women. Cancer Causes and Control 1998, 9, 433–439
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008827903302
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  • 4
    Digitale Medien
    Digitale Medien
    Chemistry of cephalic secretion of fire beeTrigona (Oxytrigona) tataira (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 451-461 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Fire bee ; Trigona (Oxytrigona) tataira ; Hymenoptera ; Apidae ; mandibular gland secretion ; enediones ; monoketones ; carboxylic esters ; hydrocarbons ; E-3-hepten-2,5-dione ; E-3-nonen-2,5-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Analysis of the volatile compounds derived from cephalic glands of the fire beeTrigona (Oxytrigona) tataira by GC-MS was undertaken. The following compounds were readily identified: hydrocarbons:n-C11H24,n-C13H28,n-C14H30,n-C15H32,n-C17H36,n-C23H48,n-C15H30,n-C17H34,n-C21 H42, andn-C23H46; carboxylic acids: palmitic acid, linoleic acid, linolenic acid, stearic acid, and oleic acid; carboxylic esters: dodecyl acetate, tetradecyl acetate, hexadecyl acetate, octadecyl acetate, and dodecyl decanoate; monoketones: 5-hepten-2-one, 3-hepten-2-one, 2-heptanone, and 5-nonen-2-one. Two major components of the mixture were identified asE-hepten-2,5-dione andE-3-nonen-2,5-dione. Structures of these novel compounds were suggested by their GC-MS behavior and the GC-MS behavior of their dimethoximes and proved by comparison with authentic synthetic samples. Trace amounts of the corresponding Z isomers and the saturated analogs, heptan-2,5-dione and nonan-2,5-dione, were also found. The possible functions of these glandular constituents are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988091
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