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881.
Multiple Dimensions of Socioeconomic Position and Obesity among Employees: The Helsinki Health Study
Mikko Laaksonen Sirpa Sarlio‐Lhteenkorva Eero Lahelma 《Obesity (Silver Spring, Md.)》2004,12(11):1851-1858
Objective: To examine socioeconomic differences in obesity using several different socioeconomic indicators, ranging from childhood socioeconomic environment and adult socioeconomic status to material resources and economic satisfaction. Research Methods and Procedures: The data derived from the Helsinki Health Study baseline surveys in 2000 and 2001. Respondents to postal surveys were middle‐aged employees of the City of Helsinki (4, 975 women and 1, 252 men, response rate 68%). Associations between eight socioeconomic indicators and obesity (BMI ≥ 30 kg/m2), calculated from self‐reported data, were examined by fitting a series of logistic regression models. Results: In women, all socioeconomic indicators except household income and economic satisfaction were associated with obesity. Parental education and childhood economic difficulties, i.e., socioeconomic conditions in childhood, remained associated with obesity after adjusting for all indicators of current socioeconomic position. Indicators of adult socioeconomic status, own education and occupational class, were no longer associated with obesity when childhood socioeconomic conditions were adjusted for. Home ownership and economic difficulties were associated with obesity after full adjustments. In men, the findings paralleled those among women, but few associations reached statistical significance. Discussion: Obesity was associated with several dimensions of socioeconomic position. Childhood socioeconomic disadvantage was associated with obesity independently of the various indicators of current socioeconomic position. Associations between obesity and both educational level and occupational class disappeared after adjustment for other indicators of socioeconomic position. This suggests that the variation observed in the prevalence of obesity by these key socioeconomic indicators may reflect differences in the related material resources. 相似文献
882.
Adaptive divergence in plasticity in natural populations of Impatiens capensis and its consequences for performance in novel habitats 总被引:4,自引:0,他引:4
Donohue K Pyle EH Messiqua D Heschel MS Schmitt J 《Evolution; international journal of organic evolution》2001,55(4):692-702
We tested for adaptive differentiation between two natural populations of Impatiens capensis from sites known to differ in selection on plasticity to density. We also determined the degree to which plasticity to density within a site was correlated with plastic responses of experimental immigrants to foreign sites. Inbred lines, derived from natural populations in an open-canopy site and a woodland site, were planted reciprocally in both original sites at naturally occurring high densities and at low density. The density manipulation represents environmental variation typically experienced within the site of a given population, and the transplant manipulation represents environmental differences between sites of different populations. Internode elongation, meristem allocation, leaf length, flowering date, and total lifetime fitness were measured. Genotypes originating in the open site, where selection favored plasticity of first internode length and flowering time (Donohue et al. 2000a), were more plastic in those characters than genotypes originating from the woodland site, where plasticity was maladaptive. Therefore, these two populations appear to have responded to divergent selection on plasticity. Plasticity to density strongly resembled plasticity to site differences for many characters, suggesting that similar environmental factors elicit plasticity both to density and to overhead canopy. Thus, plasticity that evolved in response to density variation within a site influenced phenotypic expression in the foreign site. Plastic responses to site caused immigrants from foreign populations to resemble native genotypes more closely. In particular, immigrants from the open site converged toward the selectively favored early-flowering phenotype of native genotypes in the woodland site, thereby reducing potential fitness differences between foreign and native genotypes. However, because genotypes from the woods population were less plastic than genotypes from the sun population, phenotypic differences between populations were greatest in the open site at low density. Therefore, population differences in plasticity can cause genotypes from foreign populations to be more strongly selected against in some environments than in others. However, genetic constraints and limits to plasticity prevented complete convergence of immigrants to the native phenotype in any environment. 相似文献
883.
Maria Triantaphyllou Margarita Dimiza Elisa Malinverno Ekaterini Souvermezoglou 《Geobios》2010,43(1):99
A seasonal morphological variability is observed in Emiliania huxleyi var. huxleyi specimens, collected from discrete water samples in the Aegean Sea. Biometric analyses reveal a consistent pattern of increase in the size of coccoliths and coccospheres, including the thickness of the inner tube elements (INT), in winter/spring time low sea surface temperature and moderate productivity samples when compared with summer time high temperature-low productivity samples. The small range of salinity change in the Aegean Sea and the absence of seasonal pattern in nutrient content do not support any association with the observed increase in E. huxleyi coccolith size. A relatively increased [HCO3-] content is observed during spring-time interval related with the increase in the coccolith size, however it remains unclear which parameter of the carbonate system causes the observed effects. 相似文献
884.
Virginie Clément Bernard Bibé étienne Verrier Jean-Michel Elsen Eduardo Manfredi Jacques Bouix éric Hanocq 《遗传、选种与进化》2001,33(4):369-395
Simulations were used to study the influence of model adequacy and data structure on the estimation of genetic parameters for traits governed by direct and maternal effects. To test model adequacy, several data sets were simulated according to different underlying genetic assumptions and analysed by comparing the correct and incorrect models. Results showed that omission of one of the random effects leads to an incorrect decomposition of the other components. If maternal genetic effects exist but are neglected, direct heritability is overestimated, and sometimes more than double. The bias depends on the value of the genetic correlation between direct and maternal effects. To study the influence of data structure on the estimation of genetic parameters, several populations were simulated, with different degrees of known paternity and different levels of genetic connectedness between flocks. Results showed that the lack of connectedness affects estimates when flocks have different genetic means because no distinction can be made between genetic and environmental differences between flocks. In this case, direct and maternal heritabilities are under-estimated, whereas maternal environmental effects are overestimated. The insufficiency of pedigree leads to biased estimates of genetic parameters. 相似文献
885.
The effect of an acute LD50 dose of Echis coloratus crude venom in male albino rats was tested on blood parameters: white blood cells (WBCs), red blood cells (RBCs), platelets count, hemoglobin, hematocrit, mean cell volume (MCV), mean cell hemoglobin (MCH) and mean cell hemoglobin concentration (MCHC), also serum glucose, total protein, triglycerides with alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and γ-glutamyl transferase (GGT) enzyme activities. The effect of the LD50 dose was monitored over a period of seven days, with time intervals of 1, 3, 6, 12, 24, 72 h. All of the tested parameters show fluctuations with time and with tendency to regain normal control level after 12 h. At 12–24 h it seems to be crucial for the process of physiological recovery, in spite of the irreversible damage and tissue distraction. The process of physiological adaptation and recovery from the lethal destructive venom effect seems to stabilize after one week, leaving the animal alive with several biochemical altered metabolisms and disturbed physiological profile. 相似文献
886.
In this work, N-methylene phosphonic chitosan (NMPC) based hydrogels and electrospun nanofibrous scaffolds are reported with objective to obtain osteoconductive and osteoinductive matrixes for bone grafting applications. NMPC, a phosphorylated derivative of chitosan, is known to mimic the function of non collagenous phosphoproteins in providing nucleation sites for biomineralization. NMPC hydrogels were prepared by crosslinking between NMPC and genipin. A detailed investigation of physicochemical properties of NMPC solutions is also carried out in order to obtain beads free nanofibers. Both NMPC gels and nanofibers were further evaluated for their biomineralization potential and biocompatibility with human osteoblast like cells. Results indicated that hydrogels and nanofibrous scaffolds NMPC are biocompatible and significantly osteoinductive compared to tissue culture plate controls. However, cells seeded on nanofibrous scaffolds exhibited greater proliferation measured by MTT assay, and higher expression of early markers for osteogenic differentiation proving the superior applicability of nanofibrous scaffolds for bone grafting applications. 相似文献
887.
摘要 目的:探讨胃肠道间质瘤组织S100A4、衰变加速因子(CD55)的表达及与临床病理参数及预后的关系。方法:选取2011年1月-2015年12月在陆军军医大学附属西南医院江北院区/陆军第958医院行手术切除并经术后病理确诊的124例GIST组织和对应的瘤旁正常组织病理蜡块,采用免疫组化法检测S100A4、CD55在GIST组织及瘤旁正常组织中的表达,分析其表达与GIST患者临床病理参数及预后的关系。结果:S100A4、CD55在GIST组织中的高表达率明显高于瘤旁正常组织,差异有统计学意义(P<0.05)。S100A4、CD55表达与GIST患者肿瘤大小、核分裂相、NIH分级及远处转移有关(P<0.05),与GIST患者年龄、性别、发生部位、组织学类型无关(P>0.05)。S100A4、CD55低表达的GIST患者术后复发率和转移率低于S100A4、CD55高表达的GIST患者,差异有统计学意义(P<0.05);S100A4、CD55低表达组患者5年中位无进展生存期明显高于S100A4、CD55高表达组,差异有统计学意义(P<0.05)。结论:S100A4、CD55在GIST组织存在高表达, 二者可能参与了GIST的侵袭与转移,并与患者术后的预后有关。 相似文献
888.
I. J. Manguiat G. B. Mascariña J. K. Ladha R. J. Buresh J. Tallada 《Plant and Soil》1994,160(1):131-137
Field experiments were conducted under flooded soil conditions using Maahas clay amended with urea and rice straw-sesbania mixtures during the wet and dry seasons. Parallel laboratory incubation tests were done. The objectives were 1) to determine N mineralization patterns and establish the relationship between mineralization parameters and either N availability or grain yield, and 2) to correlate the results of organic N mineralization studies in the laboratory with data from field experiments. The N mineralization patterns of flooded soils in the laboratory followed a logistic function. In laboratory studies, mineralization potential was positively correlated with extractable soil NH4
+-N at the end of the incubation period (cumulative available N). Likewise, mineralization potential calculated from laboratory studies was positively correlated with N uptake and grain yield from field studies. Extractable (NH4
++NO3
–)-N in the field correlated positively with extractable NH4
+-N in the laboratory. The extractable NH4
+-N from laboratory incubations at 14 days after transplanting, panicle initiation, and maturity was also highly and positively correlated with grain yield from field experiments. 相似文献
889.
The variation in airborne pollen concentrationof the Braga region (Portugal) was studied inspringtime, during the flowering of Vitisvinifera. The data set was obtained for twoconsecutive years (1999 and 2000), using aCour-type sampler.During this period, thirty-six taxa wereobserved in a total of 3,200 pollengrains m-3 of air (CPA). The main pollentypes observed were Olea, Poaceaea,nd Castanea, representing 74% of thepollen spectrum.The airborne pollen concentration (CPA) wassignificantly correlated with certainmeteorological parameters. Pollen concentrationwas positively correlated with temperature andwind direction (East and Northeast) andnegatively correlated with rainfall and numberof rainy days. 相似文献
890.
Eviatar Nevo John G. Moseman Avigdor Beiles Daniel Zohary 《Plant Systematics and Evolution》1984,145(1-2):79-96
The association of ecological factors and allozymic markers of wild barley,Hordeum spontaneum, with genotypes varying in resistance to 3 cultures of the pathogenErysiphe graminis hordei, which incites the disease powdery mildew of barley, were explored theoretically and practically. The study involved 275 accessions comprising 16 populations largely representing the ecological range ofH. spontaneum in Israel. From earlier studies of allozymic variation and disease resistance it now becomes apparent that genetic polymorphisms for resistance toE. graminis hordei are structured geographically, and are predictable by climatic as well as allozymic variables. Three-variable combinations of temperature and water factors explain significantly 0.32 of the spatial variance in disease resistance between localities. Also, several allozyme genotypes, singly or in combination, are significantly associated with disease resistance. A high correlation was found between the standard deviation of infection types of the culture of the pathogen from Israel, and allozymic polymorphism,P (rs = 0.86, p < 0.001). Consequently, the IsraelH. spontaneum populations, growing in the center of diversity of the species, contain large amounts of unexploited disease resistance polymorphism. These could be effectively screened and utilized for producing resistant barley varieties by using ecological factors and allozymic variants as guidelines. 相似文献