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1.
The aim of this work was to study the nycthemeral and sleep-related variations of thyrotropin (TSH) in sleeping sickness (Human African trypanosomiasis). Six untreated patients were studied during 24 hours using 10 min blood sampling and polygraphic sleep recordings. These patients were compared to 5 healthy African subjects. The patients were selected during a medical investigation in Congo. Sleeping sickness was diagnosed clinically and confirmed by the detection of Trypanosoma brucei gambiense in the blood, the cerebrospinal fluid, or in a lymph node puncture, and by a serologic immunofluorescence test. Blood was withdrawn continuously via a catheter and sampled into 10 min aliquots in an adjoining room. TSH was measured by a commercial IRMA kit. Sleep was recorded by continuous polysomnography and scored visually. The integrity of the sleep-wake cycle varied greatly among patients, ranging from major disruption with insomnia to almost undisturbed nocturnal sleep. Mean TSH levels were slightly higher in the patients than in the controls, although the difference was not significant. The nocturnal surge was preserved in all but one patient and its amplitude was not different between patients and controls. There were more TSH pulses in the patients, maybe due to fragmented sleep with many awakenings. The relationships between sleep structure and TSH variations were preserved, with decreasing TSH levels during slow-wave sleep and increasing levels after awakenings. We conclude that contrarily to other biological rhythms, the nycthemeral pattern of TSH is preserved in the sleeping sickness patients. The TSH nocturnal surge persisted, unlike in other nonthyroidal illnesses. The relationhsips between TSH variations and sleep structure are also preserved, demonstrating the robustness of this association.  相似文献   

2.
B. (Sibiricobombus) niveatus and B. (Sibiricobombus) vorticosus are analyzed and compared with selected species of the subgenera Melanobombus and Mendacibombus. Different geometric morphometric methods based on wings landmark data show that there are no morphological differences between B. niveatus and B. vorticosus. These results support the hypothesis that B. niveatus and B. vorticosus should be regarded as conspecific. On the other hand, the wing shapes show significant differences among the bumblebee species and subgenera that are coherent with their specific and subgeneric status. This approach may help future studies not only by contributing towards solving problems in systematics but also in understanding the flight mechanism of bumblebees. It also supports studies on the evolution of crossvein structure and on aerodynamics of different wing shapes in insects.  相似文献   

3.
经纬杂交试验分析新法—一般最小二乘   总被引:1,自引:0,他引:1  
潘玉春 《遗传学报》1991,18(1):23-32
经纬杂交试验主要涉及地方品种。这些品种具有两个显著特点:一是品种之内纯合程度较差,二是品种之间纯合程度不同。所以对于不同杂交组合而言,相应于观测值的误差效应不仅很大而且服从不同的分布;此时若再利用正规最小二乘进行分析,必然不能得到正确结果。本文根据客观特点,依据新的模型和最优线性无偏估计原理,对于这种试验提出了一种新的分析方法——一般最小二乘分析。这种方法只需首先估计各个组合的方差,然后用它对重复数和观测值进行校正,再按正规最小二乘分析步骤分析即可,所以并不复杂。具体使用有一实例说明。  相似文献   

4.
A review is given of the role of traditional morphometrics in plant systematics. The three most commonly used techniques of data analysis – Cluster Analysis, Principal Component Analysis and Discriminant Analysis – are discussed. The kinds of data that can be taken from palm specimens and the problems of using specimens as data sources are outlined. Published systematic studies of palms using traditional morphometrics are reviewed. More recent studies indicate that: hybrid zones between species may be common; infraspecific diversity is greater than previously suspected; there may be more than double the currently accepted number of species; and our current knowledge of morphological variation in palms is superficial. A procedure for scientific systematics is given, which incorporates traditional morphometric methods.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 103–111.  相似文献   

5.
Controlled freezing methods adopted for Thermal Analysis (TA) and Differential Thermal Analysis (DTA), were used to investigate the capacity for subcooling short shoots of Pinus silvestris L. of various ages. Both methods showed that there were no differences in subcooling temperature along the length of the short shoots. Differences in age and water content have a significant effect on the freezing profiles. Short shoots of the current years growth were able to subcool to about −13°C. One-year-old short shoots subcooled to about −9°C. There were no apparent variations in subcooling temperatures from June to September. Rainfall or dry periods had no effect on subcooling temperatures. The freezing profiles of living material was characteristic and was not repeated during subsequent freezing cycles. Detection of ice crystal formation during refreezing experiments indicated whether short shoots were alive or dead.  相似文献   

6.

Statistical methods allow the effects of uncertainty to be incorporated into finite element models. This has potential benefits for the analysis of biological systems where natural variability can give rise to substantial uncertainty in both material and geometrical properties. In this study, a simple model of the intervertebral disc under compression was created and analysed as both a deterministic and a stochastic system. Factorial analysis was used to determine the important parameters to be included in the stochastic analysis. The predictions from the model were compared to experimental results from 21 sheep discs. The size and shape of the distribution of the axial deformations predicted by the model was consistent with the experimental results given that the number of model solutions far exceeded the number of experimental results. Stochastic models could be valuable in determining the range and most likely value of stress in a tissue or implant.  相似文献   

7.
Abstract. Floristic and climate data from 150 plots in 25 sites in Galicia, Spain, were analysed to test the hypothesis that climate is the major factor governing the distribution of woody plant species. TWINSPAN classification, Detrended Correspondence Analysis and Canonical Correspondence Analysis were applied in successive stages of the data analysis to describe vegetational variation in relation to climatic gradients. Six groups of species were defined, two clearly oceanic (Maritime and Cool Maritime), one mediterranean maritime, and three mediterranean (Cold Mediterranean, Cool Mediterranean and Temperate Mediterranean). An aridity gradient was revealed as the primary factor regulating the distribution of the species considered. This main gradient reflects the transition between the Eurosiberian and Mediterranean bio-geographic regions. The gradient can be characterized by means of the Vernet bioclimatic index. A value ≥ 4 for this index can be taken to define the mediterranean zone in our study area. The mean minimum temperature in the coldest month was the second most influential climatic variable. Partial ordination analysis revealed that the residual variation was insignificant and that the observed variation in vegetation can be fully accounted for by climatic variables.  相似文献   

8.
甘肃保安族体质特征研究   总被引:28,自引:6,他引:22  
对保安族208人(男105人,女103人)的52项体质特征进行了人体测量学研究。对保安族及其周围民族体质特征的差异进行了主成份分析,找出了民族间差异的主要表现。使用主成份得分(作为变量)进行聚类的方法,对保安族和周围民族体质特征的相像相异作了分析研究,保安族和东乡族,甘肃汉族和回族较为相像,和藏族,维吾尔族,蒙古族和陕西汉族较为相异。  相似文献   

9.
不同品种、不同花期的依兰花精油成分研究   总被引:1,自引:0,他引:1  
为探讨依兰花精油的香气质量,我们对云南省西双版纳产依兰花精油以及引种栽培于西双版纳的泰国种、老挝种的依兰花精油的化学成分在Finnigan-4510 GC/MS/DS上用毛细管柱进行了定性和定量分析,鉴定了44个化学成分。分析结果表明,依兰油的香气与品种及精油中的酯类、醇类和酚醚的含量有关。倍半萜烯类和倍半萜醇类的含量越高,其香气质量越差。就西双版纳产依兰油的香气而言,依兰花由青转黄时得到的精油远较绿花和花蕾油为好。  相似文献   

10.
The 2′-deoxy-2′-fluoro-β-D-arabinofuranosyl ortho-aza-purine and -pyrimidine nucleosides manifest an unusually rigid sugar N conformation in solution.  相似文献   

11.
Time-associated variations of blood pressure became accesible due to the modern development of pressure monitoring technology. The data collection and analysis should be standardized and formulated. Time-associated changes of pressure were evaluated not only by nonparametric and conventional but also by parametric and rhythmometric estimation. The reference data (chronodesms) are essential to define the deviant magnitude of pressure. This chronobiologic approach became feasible to quantitate the efficacy of antihypertensive agents in hypertensives.  相似文献   

12.
Methods used in vicariance biogeography fall into the categories of a posteriori methods (e.g., Component Compatibility Analysis and Brooks Parsimony Analysis) and a priori methods (e.g., Component Analysis, Reconciled Tree Analysis, and Three Area Statement Analysis). Each category corresponds to a particular methodology that arrives at general area cladograms by testing null hypotheses in a particular way. A posteriori methods assume the process of vicariance only (A0) as a common cause of the distribution of different monophyletic groups of taxa under the null hypothesis. Whenever a parsimony analysis of combined data from these monophyletic groups results in a general area cladogram with homoplasy, the null hypothesis is rejected and extinction and dispersal are invoked a posteriori as ad hoc process explanations. A priori methods assume not only vicariance (A0) but also combinations of vicariance with the processes of extinction (A1) and dispersal (A2) as possible causes of the distribution of the taxa of different monophyletic groups. Each assumed set of processes corresponds to a different null hypothesis. Under the assumption of independence and thus additivity of the processes involved, the sets of area cladograms obtained under A0, A1, and A2 from data of each monophyletic group must be inclusive (requirement I). Whenever no congruent area cladograms are found in the intersection of sets of area cladograms derived under the same assumption for different monophyletic groups (II), the corresponding null hypothesis is rejected.  相似文献   

13.

In this study, we developed an approach for prosthetic foot design incorporating motion analysis, mechanical testing and computer analysis. Using computer modeling and finite element analysis, a three-dimensional (3D), numerical foot model of the solid ankle cushioned heel (SACH) foot was constructed and analyzed based upon loading conditions obtained from the gait analysis of an amputee and validated experimentally using mechanical testing. The model was then used to address effects of viscoelastic heel performance numerically. This is just one example of the type of parametric analysis and design enabled by this approach. More importantly, by incorporating the unique gait characteristics of the amputee, these parametric analyses may lead to prosthetic feet more appropriately representing a particular user's needs, comfort and activity level.  相似文献   

14.
Chronobiologic Evaluation of Drug Efficacy in Hypertension   总被引:1,自引:0,他引:1  
Time-associated variations of blood pressure became accesible due to the modern development of pressure monitoring technology. The data collection and analysis should be standardized and formulated. Time-associated changes of pressure were evaluated not only by nonparametric and conventional but also by parametric and rhythmometric estimation. The reference data (chronodesms) are essential to define the deviant magnitude of pressure. This chronobiologic approach became feasible to quantitate the efficacy of antihypertensive agents in hypertensives.  相似文献   

15.
Geographical variation of cytochrome b mitochondrial DNA (mtDNA) in chub (Leuciscus cephalus L.) was analysed in 31 samples from 20 different river basins in the Balkan Peninsula and Danube catchment. Multivariate methods of ordination were used to analyse variation of the data sets. The results were interpreted in the context of the proposed ichthyogcographic districts separating the Balkan Peninsula into two main ichthyogeographic divisions (Eastern Greece/Ponto-Acgcan and Western Greece/South Adriatic-Ionian). Boundary detection supported these two ichthyogeographic districts for L. cephalus , revealing a boundary that ran from north to south through the Balkan Peninsula and the middle of Greece. The results also revealed the existence of a third division in Central Greece. The results of ordination techniques on homogeneous zones and analysis of the molecular variance confirmed the results obtained in studying local variability (boundaries). They also allowed us to test the existence of possible subdivisions proposed by different authors inside the two main ichthyogeographic districts. These subdivisions were not supported. The multivariate methods used in this study allowed us to propose a coherent picture of chub ichthyogeographic districts in terms of boundary detection and maximal autocorrelation between populations and to explain the patterns of chub mtDNA variation. A complete interpretation of results concerning L. cephalus requires careful consideration of both boundary analysis and autocorrelative approach. Results from an the autocorrclativc approach alone could lead to substantial misinterpretations.  相似文献   

16.
大熊猫——剑齿象动物群的聚类分析   总被引:1,自引:0,他引:1  
<正> 中外学者对我国南方石灰岩溶洞出土的第四纪哺乳动物化石(按照以往的习惯,又可总称为广义的“大熊猫——剑齿象动物群”)已经进行了长期的、广泛的研究。最近有人(计宏祥,1977;黄万波,1979)对这段历史作了详尽的总结。从历史的回顾中可以看到,随着化石材料的不断积累,华南溶洞出土的第四纪哺乳动物化石已由单一  相似文献   

17.
采用不同的氯离子(Cl-)含量测试方法(摩尔法、氯离子选择电极法、电位滴定法、电导法、比浊法),对甘氨酸合成中各步骤的产物分别进行Cl-含量测试,确定出相适应的测定方法。  相似文献   

18.
生物芯片技术与食品分析   总被引:11,自引:0,他引:11  
生物芯片检测技术是一种全新的微量分析技术。本文综述了生物芯片基本技术流程包括方阵构建、样品制备、化学反应和结果检测 ;探讨了生物芯片技术在食品分析中的应用前景 ;分析了生物芯片应用的技术障碍 ,旨在为生物芯片应用发展提供理论基础。  相似文献   

19.
Abstract. An inventory was made of the vegetation and soils of a watershed area of 480 ha in the tropical rain forest of Guyana. 252 plots of 0.05 ha were sampled. In total 111 tree species > 20 cm were recorded. A TWINSPAN analysis resulted in seven groupings. Correspondence Analysis revealed that the major environmental differentiation underlying the floristic variation is according to soil type. Finally, five main forest communities were described. Most sites in the watershed area are characterized by the dominance of one or a few species. Species distribution patterns are strongly determined by soil type and drainage class.  相似文献   

20.
73份亚洲水稻恢复系农艺性状的主成分与聚类分析   总被引:5,自引:0,他引:5  
选取来自亚洲主要产稻国家的73份恢复系资源,种植在四川省德阳市和泸州市2个环境下,根据株高、单株有效穗、千粒重、单株生物量、单株稻谷产量、每穗实粒数、每穗颖花数、每日稻谷产量、每日生物量、结实率、收获指数等11个性状进行主成分与聚类分析。结果表明:通过主成分分析,将11个性状简化为4个主成分,即稻谷产量因子、生物产量因子、穗数因子和粒重因子,以上因子提供的信息量占总信息量的87.640%(德阳)和88.861%(泸州)。利用4个主成分因子进行系统聚类,在2个环境下,73份资源均聚为4大类,其中来自中国60.71%的资源聚在Ⅰ类群,主要特点是千粒重大,株高偏高,产量较高。来自印度45.45%的资源聚在Ⅱ类群,主要特点是千粒重偏小,产量、收获指数等性状均较高。4类群间差异明显,分类结果与地理来源基本一致。  相似文献   

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