广东省SARS家庭聚集性病例流行病学分析

目的　了解广东省传染性非典型肺炎 (SARS)家庭聚集性病例的流行病学特征 ,探讨家庭因素在本病传播方面的作用。方法　采用统一个案调查表 ,用描述性流行病学方法对广东省SARS家庭聚集性病例进行分析。结果　截至 5月 1 5日止 ,在广东省 1 5 1 2例SARS病例中 ,6 0户家庭出现聚集性病例 ,共 1 91例 ,占全省病例总数的1 2 6 %。家庭聚集性病例的病死率为 9 9% ,高于全省平均病死率 (3 7% ) (P <0 0 1 )。家庭聚集性病例主要发生在2 0 0 3年 1月至 3月 ,占家庭聚集性病例总数的 90 6 % (1 73/ 1 91 )。病例以 30～ 4 9岁青壮年为主 ,占 5 2 9% (1 0 1 / 1 91 ) ;职业以干部职员为主 ,占 1 3 6 % (2 6 / 1 91 ) ,其次为饮食、服务人员 ,占 1 2 6 % (2 4 / 1 91 )。 4 1 7%家庭的首发病例在发病前两周有明确或可疑接触史。在 1 2 9例家庭聚集二代感染病例中可能因陪护或探病感染发病的有 4 2户 ,共 92例 ,占71 3%。首发病例与二代病例发病时间间隔中位数为 7d。结论　家庭聚集性病例的病死率较高 ,家庭聚集性病例有较大比例可能在医院内感染 ,但家庭密切接触也是造成疫情传播的原因之一 ,控制医院内感染和及早对病例进行家庭隔离可以减少聚集性病例的出现     

Clustered data in sports research

Clustered, or dependent, data, arise commonly in sports medicine and sports science research, particularly in studies of sports injury and biomechanics, particularly in sports injury trials that are randomised at team or club level, in cross-sectional surveys in which groups of individuals are studied and in studies with repeated measures designs. Clustering, or positive correlation among responses, arises because responses and outcomes from the same cluster will usually be more similar than from different clusters. Study designs with clustering will usually required an increased sample size when compared to those without clustering. Ignoring clustering in statistical analyses can also lead to misleading conclusions, including incorrect confidence intervals and p-values. Appropriate statistical analyses for clustered data must be adopted. This paper gives some examples of clustered data and discusses the implications of clustering on the design and analysis of studies in sports medicine and sports science research.     

Growing Hierarchical Tree SOM: An unsupervised neural network with dynamic topology

In this paper we introduce a tree structured self-organizing network, called the Growing Hierarchical Tree SOM (GHTSOM), that combines unsupervised learning with a dynamic topology for hierarchical classification of unlabelled data sets. The main feature of the proposed model is a SOM-like self-organizing process that allows the network to adapt the topology of each layer of the hierarchy to the characteristics of the training set. In particular the self-organization is obtained in two steps: the first one concerns the learning phase and is finalized with the creation of a tree of SOMs, while the second one is in regard to the clustering phase and provides the formation of classes for each level of the tree (hence self-organization not only for training but also for the creation of topological connections). As a result the network works without the need for user-defined parameters. Experimental results are proposed on both synthetic and real data sets.     

Density equalized map projections: a method for analysing clustering around a fixed point

Cases plotted on a geopolitical map entail difficulties in interpretation and analysis because of variable population density in the study area. Density equalized map projections (DEMPs) eliminate the distribution of the resident population as an interfering influence by transforming map area to be proportional to population. This paper discusses a transformation algorithm, its properties, and develops statistical methods to detect clustering of cases around a fixed point for data plotted on DEMPs. We suggest two numeric methods where exact solutions are too complicated or do not exist. Finally, we illustrate these methods using data from Denver and Jefferson counties in Colorado to investigate whether lung cancer and leukaemia incidence patterns are associated with plutonium exposure from the Rocky Flats plant site.     

Validation of the rat model of cryptogenic infantile spasms

Purpose: To determine whether a new model of cryptogenic infantile spasms consisting of prenatal priming with betamethasone and postnatal trigger of spasms by N‐methyl‐d ‐aspartate (NMDA) responds to chronic adrenocorticotropic hormone (ACTH) treatment, and has electroencephalography (EEG) signature, efficacy of treatments, and behavioral impairments similar to those in human infantile spasms. Methods: Rats prenatally primed with betamethasone on gestational day 15 were used. Spasms were triggered with NMDA between postnatal days (P) 10 and 15 in a single session or in multiple sessions in one subject. The expression of spasms was compared to prenatally saline‐injected controls. Effects of relevant treatments (ACTH, vigabatrin, methylprednisolone, rapamycin) were determined in betamethasone‐primed rats. In the rats after spasms, behavioral evaluation was performed in the open field and elevated plus maze on P20–22. Key Findings: NMDA at P10–15 (the rat “infant” period) triggers the spasms significantly earlier and in greater numbers in the prenatal betamethasone‐exposed brain compared to controls. Similar to human condition, the spasms occur in clusters. Repeated trigger of spasms is associated with ictal EEG electrodecrements and interictal large‐amplitude waves, a possible rat variant of hypsarrhythmia. Chronic ACTH treatment in a randomized experiment, and chronic pretreatment with methylprednisolone significantly suppress the number of spasms similar to the human condition. Pretreatment with vigabatrin, but not rapamycin, suppressed the spasms. Significant behavioral changes occurred following multiple bouts of spasms. Significance: The model of infantile spasms has remarkable similarities with the human condition in semiology, EEG, pharmacologic response, and long‐term outcome. Therefore, the model can be used to search for novel and more effective treatments for infantile spasms.     

Identification of homogeneous genetic architecture of multiple genetically correlated traits by block clustering of genome‐wide associations

Genome‐wide association studies (GWAS) using high‐density genotyping platforms offer an unbiased strategy to identify new candidate genes for osteoporosis. It is imperative to be able to clearly distinguish signal from noise by focusing on the best phenotype in a genetic study. We performed GWAS of multiple phenotypes associated with fractures [bone mineral density (BMD), bone quantitative ultrasound (QUS), bone geometry, and muscle mass] with approximately 433,000 single‐nucleotide polymorphisms (SNPs) and created a database of resulting associations. We performed analysis of GWAS data from 23 phenotypes by a novel modification of a block clustering algorithm followed by gene‐set enrichment analysis. A data matrix of standardized regression coefficients was partitioned along both axes—SNPs and phenotypes. Each partition represents a distinct cluster of SNPs that have similar effects over a particular set of phenotypes. Application of this method to our data shows several SNP‐phenotype connections. We found a strong cluster of association coefficients of high magnitude for 10 traits (BMD at several skeletal sites, ultrasound measures, cross‐sectional bone area, and section modulus of femoral neck and shaft). These clustered traits were highly genetically correlated. Gene‐set enrichment analyses indicated the augmentation of genes that cluster with the 10 osteoporosis‐related traits in pathways such as aldosterone signaling in epithelial cells, role of osteoblasts, osteoclasts, and chondrocytes in rheumatoid arthritis, and Parkinson signaling. In addition to several known candidate genes, we also identified PRKCH and SCNN1B as potential candidate genes for multiple bone traits. In conclusion, our mining of GWAS results revealed the similarity of association results between bone strength phenotypes that may be attributed to pleiotropic effects of genes. This knowledge may prove helpful in identifying novel genes and pathways that underlie several correlated phenotypes, as well as in deciphering genetic and phenotypic modularity underlying osteoporosis risk. © 2011 American Society for Bone and Mineral Research.     

新农村建设背景下青年农民心理和谐现状的聚类分析

目的探讨新农村建设背景下青年农民心理和谐的现状。方法采用目的性取样的方法,以云南省和河南省1275名农民为被试,用心理和谐量表进行测量。结果 1性别、民族、省份和农民类型是影响青年农民心理和谐的重要因素;2通过聚类分析将青年农民的心理和谐状况分为3类,3类农民的数量存在显著的统计学差异(χ2=169.416,P0.001),只有32.47%的青年农民的心理和谐程度较好。结论中国青年农民心理和谐平均得分为3.89分,已接近4分,这是政府、社会及个人多方努力的结果,但状况参差不齐,尚未达到非常和谐的程度,应继续努力提高其心理和谐水平。     

通州市农村人群代谢综合征的因子分析

目的探讨代谢综合征（MS）患病率的性别差异,分析不同性别代谢综合征各组分的聚集特征。方法有效样本20502名,男性6997人,女性13505人,分别对其代谢综合征的组分f血压、体质指数（BMI）、腰围（WC）、血清胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL—C）、空腹血糖（FPG）1进行因子分析。结果代谢综合征患者3434人,粗患病率为16．75％,其中男性为11．52％,女性为19．46％,女性粗患病率显著高于男性（P〈0．001）;标化率为10．74％,其中男性为10．35％,女性为11．16％。男性WC、收缩压（SBP）、舒张压（DBP）高于女性,女性BMI、TC、HDL—C、FPG高于男性,差异均有统计学意义（P〈0．05）,男女性之间TG差异无统计学意义。男、女因子分析分别都提取了4个主要因子,因子方差累计贡献率分别为80．898％,78．347％。男女代谢综合征组分的聚集性基本相同但也存在差异,肥胖因子处于核心地位,血压因子为重要且独立的因子,其次是血脂紊乱因子、血糖因子。结论代谢综合征是多因素综合作用的结果,该调查研究显示肥胖因子、血压因子作用较强,男女代谢综合征的因子构成存在差异。