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1.
Cytoplasmic antigen relationships among the Actinomycetales 总被引:1,自引:0,他引:1
J B Kwapinski 《Journal of bacteriology》1964,87(5):1234-1237
Kwapinski, J. B. (The University of New England, Armidale, N.S.W., Australia). Cytoplasmic antigen relationships among the Actinomycetales. J. Bacteriol. 87:1234-1237. 1964.-Cytoplasm obtained from 44 strains of the Actinomycetales was tested against the homologous and heterologous antisera in a diffusion precipitation test. A pattern of serological relationships among the cytoplasmic fractions was revealed, with Mycobacterium smegmatis occupying a central position in the antigenic evolution of these microorganisms. 相似文献
2.
P. Bion Griffin 《American anthropologist》2001,103(2):551-552
Ants for Breakfast: Archaeological Adventures among the Kalinga. James Skibo. Salt Lake City: University of Utah Press, 1999.178 pp. 相似文献
3.
BACKGROUND AND AIMS: It is increasingly accepted that crop models, if they are to simulate genotype-specific behaviour accurately, should simulate the morphogenetic process generating plant architecture. A functional-structural plant model, GREENLAB, was previously presented and validated for maize. The model is based on a recursive mathematical process, with parameters whose values cannot be measured directly and need to be optimized statistically. This study aims at evaluating the stability of GREENLAB parameters in response to three types of phenotype variability: (1) among individuals from a common population; (2) among populations subjected to different environments (seasons); and (3) among different development stages of the same plants. METHODS: Five field experiments were conducted in the course of 4 years on irrigated fields near Beijing, China. Detailed observations were conducted throughout the seasons on the dimensions and fresh biomass of all above-ground plant organs for each metamer. Growth stage-specific target files were assembled from the data for GREENLAB parameter optimization. Optimization was conducted for specific developmental stages or the entire growth cycle, for individual plants (replicates), and for different seasons. Parameter stability was evaluated by comparing their CV with that of phenotype observation for the different sources of variability. A reduced data set was developed for easier model parameterization using one season, and validated for the four other seasons. KEY RESULTS AND CONCLUSIONS: The analysis of parameter stability among plants sharing the same environment and among populations grown in different environments indicated that the model explains some of the inter-seasonal variability of phenotype (parameters varied less than the phenotype itself), but not inter-plant variability (parameter and phenotype variability were similar). Parameter variability among developmental stages was small, indicating that parameter values were largely development-stage independent. The authors suggest that the high level of parameter stability observed in GREENLAB can be used to conduct comparisons among genotypes and, ultimately, genetic analyses. 相似文献
4.
Michael Lambek 《American anthropologist》1998,100(1):203-204
People of the Sea: Identity and Descent among the Vezo of Madagascar Rita Astuti. Cambridge: Cambridge University Press, 1995. 188 pp. 相似文献
5.
George M. Foster 《American anthropologist》1998,100(1):229-230
Fieldwork among the Maya: Reflections on the Harvard Chiapas Project. Evon Z. Vogt Albuquerque. University of New Mexico Press, 1994. 451 pp. 相似文献
6.
Sexual selection and simultaneous hermaphroditism among the Unionidae (Bivalvia: Mollusca) 总被引:1,自引:0,他引:1
Simultaneous hermaphroditism is an infrequent mode of reproduction among bivalves of the family Unionidae: only five of the 220 North American species are simultaneous hermaphrodites. However, hermaphroditic individuals of otherwise predominantly dioecious species have been encountered in 30 of I01 species examined. These hermaphroditic individuals as well as simultaneous hermaphrodites can exhibit considerable variability in the ratio of spermatogenic: oogenic tissue within the gonad, and the purposes of this paper are to determine the underlying causes of both this variability and the occurrence of occasional hermaphroditic individuals among dioecious species. Results indicate that the ratio of male: female gonodal tissue of a simultaneous hermaphrodite is bimodally distributed, and several hypotheses to account for this observation are presented. It is proposed that populations occurring in different habitats and under conditions of different individual density are subject to fundamentally different sexual selection pressures acting on ratios of allocation to male and female gametes. Occasional hermaphroditism among otherwise predominantly dioecious species was in this study associated with infection of the gonads by digenean trematodes. A model of sexual determination among unionids presented in this paper proposes that sex is determined by genetically controlled hormone levels: occasional hermaphrodites result from alterations in these hormone levels caused by developmental errors and trematodal infections which mimic the results of such errors. Predictions of this model are consistent with observed levels of variability in male: females gonadal tissue among occasional hermaphrodites. 相似文献
7.
Wirth M Burch J Violanti J Burchfiel C Fekedulegn D Andrew M Zhang H Miller DB Hébert JR Vena JE 《Chronobiology international》2011,28(5):446-457
Police officers are required to work irregular hours, which induces stress, fatigue, and sleep disruption, and they have higher rates of chronic disease and mortality. Cortisol is a well-known "stress hormone" produced via activation of the hypothalamic-pituitary-adrenal axis. An abnormal secretion pattern has been associated with immune system dysregulation and may serve as an early indicator of disease risk. This study examined the effects of long- and short-term shiftwork on the cortisol awakening response among officers (n = 68) in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) pilot study (2001-2003). The time each officer spent on day (start time: 04:00-11:59 h), afternoon (12:00-19:59 h), or night (20:00-03:59 h) shifts was summarized from 1994 to examination date to characterize long-term (mean: 14 ± 9 yrs) and short-term (3, 5, 7, or 14 days prior to participation) shiftwork exposures. The cortisol awakening response was characterized by summarizing the area under the curve (AUC) for samples collected on first awakening, and at 15-, 30-, and 45-min intervals after waking. Data were collected on a scheduled training or off day. The cortisol AUC with respect to ground (AUC(G)) summarized total cortisol output after waking, and the cortisol AUC with respect to increase (AUC(I)) characterized the waking cortisol response. Officers also completed the Center for Epidemiologic Studies Depression scale. Waking cortisol AUC values were lower among officers working short-term night or afternoon shifts than day shifts, with maximal differences occurring after 5 days of shiftwork. The duration of long-term shiftwork was not associated with the cortisol awakening response, although values were attenuated among officers with more career shift changes. 相似文献
8.
Katzmarzyk PT 《Obesity (Silver Spring, Md.)》2008,16(1):184-190
Objective: To investigate ethnic differences in obesity and physical activity among Aboriginal and non‐Aboriginal Canadians. Methods and Procedures: The sample included 24,279 Canadians (1,176 Aboriginals, 23,103 non‐Aboriginals) aged 2–64 years from the 2004 Canadian Community Health Survey (CCHS). Adult participants were classified as underweight/normal weight, overweight (BMI 25–29.9 kg/m2) or obese (BMI ≥ 30 kg/m2). Children and youth 2–17 years of age were classified as normal weight, overweight or obese based on the International Obesity Task Force criteria. Leisure‐time physical activity levels over the previous 3 months were obtained by questionnaire in those aged 12–64 years. Results: The prevalence of obesity in adults was 22.9% (men: 22.9%; women: 22.9%), and the prevalence was higher among Aboriginals (37.8%) compared to non‐Aboriginals (22.6%). The prevalence of obesity in children and youth was 8.2% (boys: 9.2%; girls: 7.2%), and the prevalence was higher among Aboriginals (15.8%) compared to non‐Aboriginals (8.0%). In both youth and adults, the odds for obesity were higher among Aboriginals (youth: OR = 2.3 (95% CI: 1.4–3.8); adults: OR = 2.4 (95% CI: 1.6–3.6)) after adjustment for a number of covariates. There were no ethnic differences in the prevalence of physical inactivity; however, physical inactivity was a predictor of obesity in both the Aboriginal and non‐Aboriginal samples. Discussion: The prevalence of obesity is higher among Canadian Aboriginals compared to the rest of the population. Further research is required to better delineate the determinants of obesity and the associated health consequences in this population. 相似文献
9.
OBJECTIVE: To compare and contrast the characteristics of suicides among aboriginal and nonaboriginal people in Manitoba. DESIGN: Retrospective review of all suicides, based on a confidential analysis of records held by the Office of the Chief Medical Examiner. SETTING: Manitoba between 1988 and 1994. OUTCOME MEASURES: Standardized suicide rates, age- and sex-specific suicide rates, blood alcohol level at time of death, psychiatric help-seeking behaviour before suicide and residence on a reserve. RESULTS: Age-standardized suicide rates were 31.8 and 13.6 per 100,000 population per year among aboriginal and nonaboriginal people, respectively. The mean age of aboriginal people who committed suicide was 27.0 (standard deviation [SD] 10.8) years, compared with a mean age of 44.6 (SD 18.8) years for nonaboriginal people who committed suicide (p < 0.001). Blood alcohol levels at the time of death were a mean of 28 (SD 23) mmol/L among aboriginal people and 12 (SD 20) mmol/L among nonaboriginal people (p < 0.0001). Before their death, 21.9% of nonaboriginal suicide victims had sought psychiatric care whereas among aboriginal suicide victims 6.6% had sought care (p < 0.0001). Although the suicide rate was higher among aboriginal people living on reserve than among those living off reserve (52.9 v. 31.3 per 100,000 per year), both of these rates were substantially higher than the overall rates among nonaboriginal people. There were no significant differences in mean age, sex, blood alcohol level and previous psychiatric care among aboriginal people who committed suicide living on and off reserve. CONCLUSIONS: There was a high rate of suicide among Manitoba''s aboriginal people between 1988 and 1994; this rate was comparable to earlier estimates of national suicide rates among aboriginal people. The reserve environment does not, by itself, account for the high suicide rate among Manitoba''s aboriginal people. Further study of help-seeking behaviour and the association between alcohol abuse and suicide, particularly among aboriginal peoples, is indicated. 相似文献
10.
Predator-mediated interactions among the seeds of desert plants 总被引:2,自引:0,他引:2
J. A. Veech 《Oecologia》2000,124(3):402-407
In theory, seed predators are capable of inducing indirect interactions among the seeds they consume. However, empirical evidence
of predator-mediated interactions among seeds is rare. Rodents in the Heteromyidae are highly granivorous and therefore likely
to induce indirect interactions among the seeds of desert plants. The indirect interactions may be in the form of apparent
competition and apparent mutualism between seeds within a patch. Apparent competition exists when the survival of seeds of
a focal species is lessened because of the presence of additional seeds of other species in the patch. Apparent mutualism
exists when the presence of the other seeds results in an increase in survival of seeds of the focal species. By measuring
seed removal from trays placed in the field, apparent competition between the seeds of several plant species was detected.
Apparent mutualism might also exist, but there was no strong evidence of it. Apparent competition appeared most likely to
occur among the species whose seeds were the most heavily predated. For instance, predation on seeds of Astragalus cicer, Oryzopsis hymenoides, and Sphaeralcea coccinea was substantial with more than 50% of the seeds removed from the trays, on average. The intensity of apparent competition
(measured by the indirect effect, IS) between these species and two others was significant; IS ranged from –0.02 to –0.39
on a scale of 0 to –1. This indicates that, in some communities, indirect effects are most likely to exist when direct effects
are strong.
Received: 5 August 1999 / Accepted: 2 March 2000 相似文献
11.
BACKGROUND:
Gujarat is located at the western most point of the Indian subcontinent. Valsad and Surat districts are part of the ‘tribal belt’of Gujarat and constitute 29.1% of total tribal population of Gujarat. These tribal populations are a rich source of gaining insights in the patterns of genetic diversity and genetico-environmental disorders against the back drop of their ecological, historical and ethnographic aspects.AIM:
The objectives were to find out a) the genetic diversity among the tribes of Gujarat with reference to haptoglobin (Hp) locus b) the relationship between Hp polymorphism and sickle cell anemia/trait.MATERIALS AND METHODS:
431 individuals belonging to eight tribal groups were studied for Hp polymorphism using polyacrylamide disc gel electrophoresis (PAGE). Hb*S was screened by dithionate tube turbididy (DTT) test and confirmed using cellulose acetate membrane electrophoresis (CAME).STATISTICAL ANALYSIS:
Allele frequency was calculated by direct gene counting method. Average heterozygosity and gene diversity were computed using software DISPAN. Analysis of molecular variance (AMOVA) was estimated using software ARLEQUIN version 3.1.RESULTS AND CONCLUSIONS:
Pattern of allele frequency distribution showed preponderance of Hp2 allele in all the eight tribal groups, which is in accordance with its frequency in different populations of Indian subcontinent. Total average heterozygosity (HT) was found to be low (0.160) but the level of genetic differentiation (GST) was found to be moderately high (5.6%). AMOVA analysis indicated least among group variance between west and south Indian populations (-0.04%) indicating the affinities of the tribes of Gujarat with that of Dravidian speaking groups. Analysis of Hp phenotypes among sickle cell anemia/ trait individuals revealed a high frequency of Hp 0-0 phenotype (92.7%) among SS individuals as opposed to only 9.7% among AS individuals, reaffirming the selective advantage of HbAS state in relation to hemolytic disorders. 相似文献12.
BACKGROUND:
Paraoxonase (PON1) can hydrolyze organophosphate pesticides (OP) and has a key role in the susceptibility of human in OP toxicity. The human-enzyme shows polymorphism and variations in the distribution profile of its phenotypes among different ethnic groups have been observed.AIMS:
To see the distribution pattern of total PON1 activity in 45 healthy attendants of poisoning cases; 121 healthy unrelated farm-labours and 59 normal subjects of trauma.MATERIALS AND METHODS:
The PON1 activities from serum/plasma samples of these healthy normal individuals were estimated with/without addition of 1M NaCl in order to determine salt-stimulated and basal activity. The PON 1 phenotypes were determined on the basis of percent activation of enzyme activity.RESULTS:
Tri-modal distribution of basal PON1 activity was observed among all these individuals. 52.0% of the individuals belonged to Phenotype A, 46.6% to phenotype AB while 1.4% to Phenotype B with gene frequency of allele-A and allele-B being 0.753 and 0.247 respectively in excellent agreement with Hardy-Weinberg equilibrium.CONCLUSION:
Maximum number of individuals belonged to phenotype-A (low PON1 activity) showing potential vulnerability towards Op-poisoning. 相似文献13.
Paul L. Reiter Mira L. Katz Mack T. Ruffin Erinn M. Hade Cecilia R. DeGraffenreid Divya A. Patel Electra D. Paskett Elizabeth R. Unger 《PloS one》2013,8(8)
Background
Cervical cancer incidence and mortality rates are high among women from Appalachia, yet data do not exist on human papillomavirus (HPV) prevalence among these women. We examined the prevalence of genital HPV among Appalachian women and identified correlates of HPV detection.Methods
We report data from a case-control study conducted between January 2006 and December 2008 as part of the Community Awareness, Resources, and Education (CARE) Project. We examined HPV prevalence among 1116 women (278 women with abnormal Pap tests at study entry [cases], 838 women with normal Pap tests [controls]) from Appalachian Ohio. Analyses used multivariable logistic regression to identify correlates of HPV detection.Results
The prevalence of HPV was 43.1% for any HPV type, 33.5% for high-risk HPV types, 23.4% for low-risk HPV types, and 12.5% for vaccine-preventable HPV types. Detection of any HPV type was more common among women who were ages 18–26 (OR = 2.09, 95% CI: 1.26–3.50), current smokers (OR = 1.86, 95% CI: 1.26–2.73), had at least five male sexual partners during their lifetime (OR = 2.28, 95% CI: 1.56–3.33), or had multiple male sexual partners during the last year (OR = 1.98, 95% CI: 1.25–3.14). Similar correlates were identified for detection of a high-risk HPV type.Conclusions
HPV was prevalent among Appalachian women, with many women having a high-risk HPV type detected. Results may help explain the high cervical cancer rates observed among Appalachian women and can help inform future cervical cancer prevention efforts in this geographic region. 相似文献14.
William R. Merrifield 《American anthropologist》2002,104(1):343-344
Mortuary Feasting on New Ireland: The Activation of Matriliny among the Sursurunga. Alexander H. Bolyanatz. Westport, CT: Bergin and Garvey, 2000.182 pp. 相似文献
15.
Zúñiga-Vega JJ Suárez-Rodríguez M Espinosa-Pérez H Johnson JB 《Journal of fish biology》2011,79(4):1029-1046
In viviparous organisms, pregnant females typically experience an increase in body mass and body volume. In this study, the prediction that variation in reproductive traits among populations of viviparous organisms should be related to variation among populations in body shape was tested in the Pacific molly Poecilia butleri, a viviparous fish that inhabits western Mexico and northern Central America. Variation among 10 populations in four reproductive traits was examined: brood size, individual embryo mass, total reproductive allotment and degree of maternal provisioning of nutrients to developing embryos. Variation among these populations in body shape was also examined. Significant variation among populations was observed in both brood size and reproductive allotment but not in embryo mass or degree of maternal provisioning. Significant variation among populations was also observed in body shape. After correcting for female size, however, reproductive traits and body shape were not associated among populations. This suggests that selective pressures acting on reproduction do not necessarily affect morphology and vice versa. Several factors might contribute to this unexpected lack of association between reproductive traits and morphology. 相似文献
16.
Marjorie Mandelstam Balzer 《American anthropologist》1997,99(3):672-673
Shamans and Elders: Experience, Knowledge and Power among the Daur Mongols. Caroline Humphrey. with Urgunge Onon. Oxford, England: Oxford University Press, 1996.396 pp. 相似文献
17.
Jizzo R. Bosdriesz Nienke Lichthart Margot I. Witvliet Wim B. Busschers Karien Stronks Anton E. Kunst 《PloS one》2013,8(3)
Objectives
Smoking among migrants is known to differ from the host population, but migrants’ smoking is rarely ever compared to the prevalence of smoking in their country of origin. The goal of this study is to compare the smoking prevalence among migrants to that of both the US-born population and the countries of origin. Further analyses assess the influence of sex, age at time of entry to the US and education level.Methods
Data of 248,726 US-born and migrants from 14 countries were obtained from the Tobacco Use Supplement to the Current Population Survey (TUS-CPS) from 2006–2007. Data on 108,653 respondents from the corresponding countries of origin were taken from the World Health Survey (WHS) from 2002–2005.Results
The prevalence of smoking among migrants (men: 14.2%, women: 4.1%) was lower than both the US-born group (men: 21.4%, women: 18.1%) and countries of origin (men: 39.4%, women: 11.0%). The gender gap among migrants was smaller than in the countries of origin. Age at time of entry to the US was not related to smoking prevalence for migrants. The risk of smoking for high-educated migrants was closer to their US counterparts.Conclusions
The smoking prevalence among migrants is consistently lower than both the country of origin levels and the US level. The theory of segmented assimilation is supported by some results of this study, but not all. Other mechanisms that might influence the smoking prevalence among migrants are the ‘healthy migrant effect’ or the stage of the smoking epidemic at the time of migration. 相似文献18.
David S. Freedman John C. Thornton Zuguo Mei Jack Wang William H. Dietz Richard N. Pierson Mary Horlick 《Obesity (Silver Spring, Md.)》2004,12(5):846-853
Objectives : Although BMI (kilograms per meter squared) is widely used as a surrogate measure of adiposity, it is moderately associated (r ~ 0.3) with height among children. We examined whether the resulting preferential classification of taller children as overweight, based on a BMI ≥95th percentile, is appropriate. Research Methods and Procedures : We assessed the cross‐sectional relation of height among 5‐ to 18‐year‐old subjects (n = 1180) to levels of BMI, the sum of 10 skinfold thicknesses, and percentage body fat as determined by DXA. Results : The prevalence of a BMI level ≥95th percentile was substantially higher among 5‐ to 11‐year‐old subjects who were relatively tall for their age than among shorter children. Among 5‐ to 8‐year‐old boys, for example, each SD increase in height‐for‐age was associated with a 4.6‐fold increase in the prevalence of overweight (p < 0.001). Height not only was associated with BMI but also showed similar correlations with the skinfold sum and with percentage body fat; furthermore, the magnitudes of these associations decreased with age. We also found that the association between percentage body fat and BMI (r = 0.85 to 0.90) was close to the maximum correlation that can be achieved by any weight‐height index. Discussion : The use of BMI, which preferentially classifies taller young children as overweight, is appropriate because height and adiposity are correlated before the age of 12 years. 相似文献
19.
Besser LM Shin M Kucik JE Correa A 《Birth defects research. Part A, Clinical and molecular teratology》2007,79(11):765-774
BACKGROUND: Down syndrome (DS) prevalence estimates beyond infancy are needed to assess health service needs among those with DS. METHODS: Children with DS born in metropolitan Atlanta from 1979 through 2003 were ascertained from a population-based birth defects registry. Vital status through 2003 was obtained using case records, vital records, and the National Death Index. Prevalence was calculated by dividing the children surviving with DS by the population derived from U.S. Census estimates. Variations in DS prevalence by race, heart defects, age, birth cohort, and time period were examined using Poisson regression. RESULTS: In metropolitan Atlanta in 2003, there were 67 livebirths with DS (13.0 per 10,000 livebirths) and 738 0- to 19-year-olds surviving with DS (8.3 per 10,000 population). Over time, births to mothers 35 years and older and DS birth prevalence increased. Birth prevalence was higher among Whites, did not vary by sex, and was higher for infants without heart defects. DS prevalence among 0- to 14-year-olds increased over time (p < .05). Within each 5 year birth cohort, prevalence decreased with age: this decrease was greater among Blacks than among Whites and among children with heart defects than among children without heart defects. CONCLUSIONS: DS prevalence increased among livebirths and among young children. Further studies are warranted to determine whether health services are meeting the needs of an increasing number of children with DS. 相似文献
20.
Context: IL-27 is a novel biomarker to identify bacterial infection in children.Objective: IL-27 was evaluated among pediatric emergency department (ED) patients and compared with procalcitonin (PCT).Methods and results: Children undergoing blood, urine, or cerebrospinal fluid cultures had IL-27 and PCT assays performed. Bacterial infection was defined as a positive culture or a clinical diagnosis based on chart review. IL-27 and PCT were increased among patients with bacterial infection and demonstrated comparable AUC’s (0.62 versus 0.61). A decision tree incorporating IL-27, PCT, and white blood cell count improved the AUC (0.80).Conclusion: IL-27 is a viable candidate biomarker to identify bacterial infection among ED patients and is comparable with PCT. 相似文献