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41.
This study was conducted to establish the contribution of genetic host factors in the susceptibility to community acquired pneumonia (CAP) in the Russian population. Patients with CAP (n = 334), volunteers without a previous history of CAP, constantly exposed to infectious agents, control A group (n = 141) and a second control group B consisted of healthy persons (n = 314) were included in the study. All subjects were genotyped for 13 polymorphic variants in the genes of xenobiotics detoxification CYP1A1 (rs2606345, rs4646903, and rs1048943), GSTM1 (Ins/del), GSTT1 (Ins/del), ABCB1 rs1045642); immune and inflammation response IL-6 (rs1800795), TNF-a (rs1800629), MBL2 (rs7096206), CCR5 (rs333), NOS3 (rs1799983), angiotensin-converting enzyme ACE (rs4340), and occlusive vascular disease/hyperhomocysteinemia MTHFR (rs1801133). Seven polymorphic variants in genes CYP1A1, GSTM1, ABCB1, NOS3, IL6, CCR5 and ACE were associated with CAP. For two genes CYP1A1 and GSTM1 associations remained significant after correction for multiple comparisons. Multiple analysis by the number of all risk genotypes showed a highly significant association with CAP (P = 2.4 × 10− 7, OR = 3.03, 95% CI 1.98–4.64) with the threshold for three risk genotypes. Using the ROC-analysis, the AUC value for multi-locus model was estimated as 68.38.  相似文献   
42.
川西亚高山红桦-岷江冷杉林优势种群的空间格局分析   总被引:2,自引:0,他引:2  
以红桦-岷江冷杉林4 hm2样地调查数据为基础,采用点格局分析法O-ring函数,分析了红桦和岷江冷杉2个优势种群不同龄级的空间分布格局,以及各龄级间的种内和种间关联性.结果表明:红桦种群径级分布呈单峰型,为衰退种群;岷江冷杉种群径级分布呈倒“J”型,为进展种群.岷江冷杉与红桦大树在所有尺度上均为随机分布,其余龄级在小尺度上为聚集分布,随尺度增大趋于随机分布和均匀分布,最大聚集强度随龄级增大而减弱.空间关联主要发生在小尺度上.岷江冷杉种内关联以小尺度正关联为主,红桦种内关联以小尺度负关联为主.对于2个种群的相同龄级,小龄级、中龄级和大龄级间,分别以空间无关联、负关联和无关联为主.2个种群间不同龄级间以负关联为主,龄级相差越大,其负关联越强.  相似文献   
43.
The German Wildlife Information System, founded in 2001, is a long-term monitoring program documenting occurrence, number, and development of game populations throughout Germany. Population numbers are recorded by standardized counting methods in so-called reference areas. The population densities of the European hare are calculated by spotlight strip censuses in the reference areas each spring and autumn all across Germany. From 2002 to 2005, the censuses were carried out by local hunters in 510 to 676 reference areas each year. During these years, the calculated spring densities increased significantly from 11.0 (2002) to 14.5 hares/km2 (2005) nationwide. The overall increase in spring densities was primarily caused by the population rise from spring 2003 to 2004, which correlates with the high net growth rate in 2003. In 2005, the number of counted hares varied between less than 1 and more than 107 hares/km2 in spring and between 0 and more than 170 hares/km2 in autumn. Because of differing landscapes in Germany, three regions were differentiated. In spring 2005, the average population densities (median) in East Germany (5.4 hares/km2) and Southwest Germany (14.6 hares/km2) were significantly lower than in Northwest Germany (23.9 hares/km2). These regional differences had been similarly distinct in former years.  相似文献   
44.
Daily and seasonal fluctuations in temperature present significant challenges for the survival of many ectothermic species that can be tempered via thermal acclimation. In the present study, we use multiple naturally derived genotypes of Drosophila melanogaster to determine the persistence of beneficial short‐term thermal acclimation on subsequent survival after cold shock. We found that the benefit of short‐term acclimation persisted for 2 h in most genotypes after a rapid cold hardening treatment. Genotype did not directly influence the persistence of short‐term acclimation benefits, indicating that environmental variation may be more important for the persistence of acclimation benefits rather than genetic capacity for acclimation. The present study extends the current understanding of the limits and importance of short‐term acclimation events, providing greater detail on the timing of the loss of short‐term acclimation benefits in a genetically variable natural population.  相似文献   
45.
46.
Integrated data of calcareous plankton and benthic foraminifers from the pre-evaporitic interval of Trave section (Central Italy) allowed the reconstruction of surface and bottom-water conditions in the Central Mediterranean during the interval from 7.61 to 6.33 Ma, preceding the Messinian Salinity Crisis.Our data point out a three-step paleoenvironmental evolution. During the first stage (7.61-7.02 Ma) benthic foraminiferal assemblages depict stable, well-oxygenated and ventilated bottom-water conditions, while the surface water records variable temperature and high nutrient conditions, probably associated with strong seasonality. The second stage (7.02-6.70 Ma) points to unfavourable bottom-water condition, triggered by deep-sea stagnation. This is witnessed by a significant decrease in oxygen concentration and biotic diversity, and by the presence of stress-tolerant taxa. A general warming of the surface water and a strongly stratified water column, characterized by an expanded mixed layer, are also recorded.From 6.70 Ma onwards (third stage), a prominent change to more restricted, low-oxygenated, hypersaline conditions at the sea floor is testified by the total disappearance of deep-dwelling planktonic foraminifers and the increasing abundance of stress-tolerant species. Calcareous plankton reflects high instability of the surface water in terms of nutrients, temperature and salinity. During this stage the environmental deterioration reaches intermediate depths in the water column.The initial change toward a step-wise isolation of the Central Mediterranean bottom-waters is probably related to a general warming, responsible for a first slowing-down of the vertical circulation, favouring stratification of surface and intermediate waters and stagnation of bottom-waters. This warming is related to the restricted connection between the Mediterranean Sea and the Atlantic Ocean, which occurred since 7.146 Ma.In the Trave section, the isolation of bottom-waters most likely occurred at the same time as in other Mediterranean sections. However, due to the presence of a hiatus it cannot be excluded that it occurred with a delay of ~ 100 kyr, probably related to the shallower paleodepth of the basin.  相似文献   
47.
肥须亚麻蝇幼虫头咽骨形态学分析及其法医学意义   总被引:1,自引:0,他引:1  
王玲  刘彬  李泽民 《昆虫知识》2008,45(1):133-137,F0002
为了明确肥须亚麻蝇Parasarcophaga crassipalpis Macguart幼虫头咽骨形态学特征的变化规律,分别在16,20,24,28和32℃下饲养肥须亚麻蝇幼虫并定期取样,显微镜下观察其形态变化,利用图像分析软件测量其口钩和咽骨的面积、平均光密度及骨化面积等形态参数。结果显示:在所测量口钩和咽骨的7项指标中,咽骨的平均光密度及骨化面积是最理想的幼虫日龄的判断指标,对尸体上死后间隔时间的推测具有重要的指导意义;口钩部的4项指标在龄期更叠时有明显变化,仅可进行龄期的鉴别。  相似文献   
48.
Understanding WaveShrink: Variance and bias estimation   总被引:15,自引:0,他引:15  
BRUCE  ANDREW G.; GAO  HONG-YE 《Biometrika》1996,83(4):727-745
  相似文献   
49.
利用非线性动力学的方法 ,在多种生物数据中找到了确定性机制。大鼠下丘脑视上核(supraopticnucleus,SON)神经元自发产生不规则的放电。为了研究这些不规则放电是否含有确定性机制 ,用电流钳对大鼠SON神经元进行全细胞纪录,取动作电位峰峰间期序列(interspikeinterval,ISI)作为研究对象。采用一种新的检测时间序列非稳定周期轨道的方法分析ISI序列 ,发现ISI含有非稳定周期轨道族 ,即周期1 ,周期2 ,和周期3存在。结果表明 ,SON神经元的自发放电序列存在确定性的动力学机制。  相似文献   
50.
Problems of establishing equivalence or noninferiority between two medical diagnostic procedures involve comparisons of the response rates between correlated proportions. When the sample size is small, the asymptotic tests may not be reliable. This article proposes an unconditional exact test procedure to assess equivalence or noninferiority. Two statistics, a sample-based test statistic and a restricted maximum likelihood estimation (RMLE)-based test statistic, to define the rejection region of the exact test are considered. We show the p-value of the proposed unconditional exact tests can be attained at the boundary point of the null hypothesis. Assessment of equivalence is often based on a comparison of the confidence limits with the equivalence limits. We also derive the unconditional exact confidence intervals on the difference of the two proportion means for the two test statistics. A typical data set of comparing two diagnostic procedures is analyzed using the proposed unconditional exact and asymptotic methods. The p-value from the unconditional exact tests is generally larger than the p-value from the asymptotic tests. In other words, an exact confidence interval is generally wider than the confidence interval obtained from an asymptotic test.  相似文献   
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