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排序方式: 共有239条查询结果,搜索用时 15 毫秒
101.
Anton Chernenko Luke Holman Heikki Helanterä Liselotte Sundström 《Journal of chemical ecology》2012,38(12):1474-1482
Communication between organisms involves visual, auditory, and olfactory pathways. In solitary insects, chemical recognition cues are influenced mainly by selection regimes related to species recognition and sexual selection. In social insects, chemical recognition cues have an additional role in mediating recognition of society members and, thereby, allowing kin selection to operate. Here, we examined whether cuticular hydrocarbon profiles are sex-specific and whether males and young queens of the ant Formica fusca have colony-specific profiles. We also investigated whether there is a relationship between genetic relatedness and chemical diversity within colonies. We demonstrated that female and male sexuals do not have unique sex-specific compounds, but that there are quantitative chemical differences between the sexes. Out of the 51 cuticular hydrocarbon compounds identified, 10 showed a significant quantitative difference between males and females. We also showed that both males and females have a significant colony-specific component in their profiles. Finally, we found a negative correlation between within-colony relatedness and within-colony chemical diversity of branched, but not linear compounds. This suggests that colonies with multiple matri- or patrilines also have a significantly greater chemical diversity. 相似文献
102.
KA Johnson MF Kijewski JA Becker B Garada A Satlin BL Holman 《Canadian Metallurgical Quarterly》1993,34(11):2044-2048
To improve the diagnostic utility of brain single-photon emission computed tomography (SPECT) in Alzheimer's disease (AD), we have developed and evaluated an objective method of differentiating patients and healthy elderly controls using a quantitative image analysis protocol. HMPAO-SPECT image datasets from 29 patients with probable AD and 78 age-matched controls were registered to a common anatomic frame of reference. Activity levels within 120 standardized cortical volumes were determined by an automated procedure. Subjects were classified into normal and AD groups by quadratic discriminant analysis using two features: global average activity level and average normalized activity levels within the two clusters of standardized volumes identified as most significantly different in AD by analysis of covariance. The classification used split-half replication to ensure valid results. Classification performance quantified by the area under a binormal ROC curve fitted to the data was 0.923 +/- 0.036; at a threshold likelihood ratio of 1, the sample sensitivity was 91% and specificity was 86%. We conclude that quantitative SPECT accurately distinguishes AD patients from elderly controls. 相似文献
103.
Fatty acid compositions of the major serum lipid classes from 43 cystic fibrosis (CF) homozygotes (CF patients), 36 obligate
heterozygotes (parents of CF patients) and 34 controls were determined by capillary gas chromatography. Fatty acid compositions
of the homozygote CF patients were skewed in the direction of relative essential fatty acid deficiency in comparison with
the controls. Less pronounced, but similar deviations from normal, were observed in the heterozygotes. Homozygotes with normal
fatty acid compositions and heterozygotes with considerably disturbed fatty acid profiles were found. 相似文献
104.
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106.
Banning tobacco sponsorship: replacing tobacco with health messages and creating health-promoting environments 总被引:3,自引:2,他引:3
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C. D. Holman R. J. Donovan B. Corti G. Jalleh S. K. Frizzell A. M. Carroll 《Tobacco control》1997,6(2):115-121
OBJECTIVE: To evaluate the replacement of Western Australian tobacco sponsorship with health promotion sponsorship by the Western Australian Health Promotion Foundation (known as "Healthway"), following the Tobacco Control Act 1990. DESIGN: Process measures of performance were collected from 25 tobacco replacement projects (sponsorship by Healthway of sport, racing, and arts groups previously supported by tobacco companies) and 727 other health sponsorship projects, that is, new sponsorship provided by Healthway to these groups. Cross-sectional survey data were obtained from 917 respondents at tobacco replacement and 2352 at other sponsorship venues. SETTING: Sport, racing, and arts venues sponsored by the Western Australian Health Promotion Foundation (Healthway) in 1991-95. MAIN OUTCOME MEASURES: Population reach, occasions of media publicity, healthy structural changes, cognitive/attitudinal impact of health messages, and the prevalence of five health-risk behaviours. RESULTS: Tobacco replacement and other sponsorship projects achieved comparable performance in publicity for health messages and in healthy structural change, but replacement projects achieved a fourfold higher level of direct population reach for a given amount of funding. Structural change towards a smoke-free environment occurred more often in tobacco replacement projects and a permanent smoke-free policy was achieved in 47% of projects, compared with 15% in other sponsorship projects. The prevalence ratio of current smoking at tobacco replacement venues was 1.86 (95% confidence interval 1.62 to 2.04) relative to other sponsorship venues. There was evidence of higher cognitive resistance to health messages at venues previously sponsored by tobacco companies. CONCLUSIONS: A comprehensive ban on tobacco sponsorship linked to health promotion activities funded by tobacco tax delivers potential public health benefits that exceed those achieved by prohibition of tobacco sponsorship alone. Tobacco replacement venues offer opportunities for environmental modification, promotion of anti-smoking messages, and targeting groups that are hard to reach.
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107.
Kalabegishvili TL Tsibakhashvili NY Holman HY 《Environmental science & technology》2003,37(20):4678-4684
Bacterial reduction of Cr(VI) to Cr(III) compounds may produce reactive intermediates Cr(V) and Cr(IV), which can affect the mobility and toxicity of chromium in environments. To address this important subject, we conducted an electron spin resonance (ESR) study to understand the kinetics of the formation and decomposition of Cr(V) during Cr(VI) reduction by different gram-positive Cr(VI)-tolerant bacteria, which were isolated from polluted basalts from the United States of America and the Republic of Georgia. Results from our batch experiments show that during Cr(VI) reduction, the macromolecules at the cell wall of these bacteria could act as an electron donor to Cr(VI) to form a stable square-pyramidal Cr(V) complexes, which were reduced further probably via a one-electron transfer pathway to form Cr(IV) and Cr(III) compounds. The Cr(V) peak at the ESR spectrum possessed superhyperfine splitting characteristic of the Cr(V) complexes with diol-containing molecules. It appears that the kinetics of Cr(V) formation and decomposition depended on the bacterial growth phase and on the species. Both formation and decomposition of Cr(V) occurred more quickly when Cr(VI) was added at the exponential phase. In comparison with other gram-positive bacteria from the republic of Georgia, the formation and decomposition of Cr(V) in Arthrobacter species from the Unites States was significantly slower. 相似文献
108.
Holman HY Goth-Goldstein R Aston D Yun M Kengsoontra J 《Environmental science & technology》2002,36(6):1281-1286
Petroleum hydrocarbon residues in weathered soils may pose risks to humans through the ingestion pathway. To understand the factors controlling their gastrointestinal (GI) absorption, a newly developed experimental extraction protocol was used to model the GI solubility of total petroleum hydrocarbon (TPH) residues in highly weathered soils from different sites. The GI solubility of TPH residues was significantly higher for soil contaminated with diesel than with crude oil. Compared to the solubility of TPH residues during fasted state,the solubility of TPH residues during fat digestion was much greater. Diesel solubility increased from an average of 8% during the "gallbladder empty" phase of fasting (and less than 0.2% during the otherfasting phase) to an average of 16% during fat digestion. For crude oil, the solubility increased from an average of 1.2% during the gallbladder empty phase of fasting (and undetectable during the other fasting phase) to an average of 4.5% during fat digestion. Increasing the concentration of bile salts also increased GI solubility. GI solubility was reduced by soil organic carbon but enhanced by the TPH content. 相似文献
109.
Controlled interpersonal affect regulation refers to the deliberate regulation of someone else’s affect. Building on existing research concerning this everyday process, the authors describe the development of a theoretical classification scheme that distinguishes between the types of strategy used to achieve interpersonal affect regulation. To test the theoretical classification, the authors generated a corpus of 378 distinct strategies using self-report questionnaires and diaries completed by student and working samples. Twenty participants then performed a card-sort of the strategies. Hierarchical cluster analysis was used to determine how well the theoretical classification represented spontaneous understandings of controlled interpersonal affect regulation. The final classification primarily distinguished between strategies used to improve versus those used to worsen others’ affect, and between strategies that engaged the target in a situation or affective state versus relationship-oriented strategies. The classification provides a meaningful basis for organizing existing research and making future conceptual and empirical distinctions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
110.
RJ Cerfolio RP Tummala WL Holman GL Zorn JK Kirklin DC McGiffin DC Naftel AD Pacifico 《Canadian Metallurgical Quarterly》1998,66(5):1726-1731
BACKGROUND: Air leaks (ALs) are a common complication after pulmonary resection, yet there is no consensus on their management. METHODS: An algorithm for the management of chest tubes (CT) and ALs was applied prospectively to 101 consecutive patients who underwent elective pulmonary resection. Air leaks were graded daily as forced expiratory only, expiratory only, inspiratory only, or continuous. All CTs were kept on 20 cm of suction until postoperative day 2 and were then converted to water seal. On postoperative day 3, if both a pneumothorax and AL were present, the CT was placed to 10 cm H2O of suction. If a pneumothorax was present without an AL, the CT was returned to 20 cm H2O of suction. Air leaks that persisted after postoperative day 7 were treated with talc slurry. RESULTS: There were 101 patients (67 men); on postoperative day 1, 26 had ALs and all were expiratory only. Univariable analysis showed a low ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) (p = 0.005), increased age (p = 0.007), increased ratio of residual volume to total lung capacity (RV/TLC) (p = 0.04), increased RV (p = 0.02), and an increased functional residual capacity (FRC) (p = 0.02) to predict the presence of an AL on postoperative day 1. By postoperative day 2, 22 patients had expiratory ALs. After 12 hours of water seal, 13 of the 22 patients' ALs had stopped, and 3 more sealed by the morning of postoperative day 3. However, 2 of the 6 patients whose ALs continued experienced a pneumothorax. Five of the 6 patients with ALs on postoperative day 4 still had ALs on postoperative day 7, and all were treated by talc slurry through the CT. All ALs resolved within 24 hours after talc slurry. CONCLUSIONS: Most ALs after pulmonary resection are expiratory only. A low FEV1/FVC ratio, increased age, increased RV/TLC ratio, increased RV, and an increased FRC were predictors of having an ALs on postoperative day 1. Conversion from suction to water seal is an effective way of sealing expiratory AL, and pneumothorax is rare. If an expiratory AL does not stop by postoperative day 4 it will probably persist until postoperative day 7, and talc slurry may be an effective treatment. 相似文献