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1.
目前GenBank数据库共收录167种直翅目昆虫全线粒体基因组序列,涉及蝗亚目9个总科22个科99个物种,螽亚目7个总科12个科68个物种。在此基础上,该文分析了直翅目昆虫线粒体基因组的基本特征,概述了线粒体全基因组在直翅目昆虫系统发育研究上的应用;同时基于线粒体全基因组序列重建了直翅目昆虫的系统发育关系。主要结果如下:(1)直翅目昆虫存在8种线粒体基因组排列类型,其中trnK-trnD重排现象仅发生在蝗总科中,trnN-trnS-trnE重排现象仅发生在蟋蟀总科中,trnM-trnI-(-trnQ)重排现象仅发生在拟叶蟲亚科中;(2)直翅目昆虫全线粒体基因组的碱基组成具有明显的AT偏向性;(3)不同的蛋白质编码基因在直翅目昆虫中的进化速率不同;(4)支持直翅目以及螽亚目和蝗亚目的单系性;(5)不支持沙螽总科单系性;(6)支持蝗亚目各总科阶元的单系性,且各总科间的系统发育关系为:(蚤蝼总科+(蚱总科+(?蜢总科+(蜢总科+(长角蝗总科+(牛蝗总科+叶翅蝗总科)+(锥头蝗总科+蝗总科))))))。  相似文献   

2.
随着植物分子系统学的兴起,被子植物系统发育研究取得了举世瞩目的进展。被子植物系统发育组提出了基于DNA证据的被子植物在目、科分类阶元上的分类系统,简称APG系统。本文简要概括了APG系统的主要成就:(1)验证了被子植物分类系统的可重复性和可预言性;(2)解决了一些依据形态学性状未能确定的类群的系统位置;(3)证明了将被子植物一级分类分为双子叶植物和单子叶植物的不自然性;(4)证实了单沟花粉和三沟花粉在被子植物高级分类单元划分中的重要性;(5)发现雄蕊的向心发育和离心发育在多雄蕊类群中是多次发生的,不应作为划分纲或亚纲的重要依据;(6)支持基于形态学(广义)性状划分的大多数科是自然的;(7)将一些长期认为自然的科四分五裂。同时,我们指出了尚需深入研究的几个问题:(1)如何将以分子数据建立的系统和以综合形态学证据建立的系统相协调;(2)依据APG系统的研究结果需要创立新的形态演化理论;(3)只以"单系群"作为划分科、目的依据值得商榷;(4)APG系统中一些目的分类没有可信的形态学共衍征;(5)依据APG系统需要做出一个自然系统的目、科检索表和目、科的特征集要。此外,我们对以亚洲,特别是东亚为分布中心的一些类群的系统关系或分类等级提出建议,包括八角科、芒苞草科、水青树科、火筒树科、马尾树科、七叶树科、槭树科、伯乐树科应独立为科,山茱萸科(广义)应分为山茱萸科(狭义)和蓝果树科(广义)。  相似文献   

3.
运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP 软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示:(1)红豆杉科和三尖杉科属单系群;(2) 穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;(3)白豆杉应为红豆杉科内一个属Pseudotaxus;(4) 三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;(5) 不赞同将竹柏类从罗汉松属中分离出去成立新科;(6) 红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。  相似文献   

4.
测定了中国鲹科8属9种鱼的细胞色素b基因的全序列(1141bp),结合来自GenBank中分布于美国、安哥拉、希腊以及巴拿马的鲹科4属14种鱼的相应同源序列生成供系统发育分析的序列矩阵,用最大简约法和邻接法构建分子系统树。结果显示:(1)支持科下设四个亚科(鲹亚科,亚科,鲳鲹亚科,鰆鲹科)阶元的分类系统;(2)亚科属下不宜设亚属分类阶元;(3)及达副叶鲹与丽叶鲹亲缘关系较近,应同属于副叶鲹属;(4)我国传统的鱼类检索系统将狮鼻鲳鲹误鉴定为卵形鲳鲹,建议予以修正。  相似文献   

5.
泗洱自然保护区种子植物区系特征分析   总被引:9,自引:0,他引:9  
在对泗洱自然保护区详细调查的基础上,对其种子植物的科、属的分布区类型进行了统计分析。结果表明:(1)保护区内种子植物类群丰富;(2)优势科、属明显;(3)区系起源古老;(4)地理成分复杂;(5)种子植物区系在科和属级水平上均显示出温带性质,同时泛热带类型丰富;(6)保护区内植被具明显的过渡性质;(7)分化现象明显,中间类型和特有种丰富。  相似文献   

6.
千佛山自然保护区种子植物区系特征研究   总被引:5,自引:0,他引:5  
在对千佛山自然保护区详细调查的基础上,对其种子植物的科、属分布区类型进行了统计分析。结果表明:(1)保护区内种子植物丰富,共153科767属2494种;(2)优势科、属明显;(3)区系起源古老;(4)种子植物地理成分复杂,吴征镒划分的中国种子植物属的15大分布类型在千佛山均有分布;(5)种子植物区系在科和属级水平上均显示出温带性质,温带分布属475属,占总属数的61.9%;(6)特有属、种丰富。  相似文献   

7.
湖北省荆门荆山余脉种子植物区系研究   总被引:4,自引:0,他引:4  
对湖北省荆门荆山余脉种子植物区系进行了统计分析。结果表明:(1)物种多样性丰富,共有野生种子植物128科、576属、1226种;(2)优势科、属明显;(3)分布区类型多样,地理成分复杂;(4)温带性质明显,热带成分丰富,与热带植物区系有较高的亲缘关系,并表现出一定的过渡性;(5)区划上属于华东植物地区。  相似文献   

8.
秦皇岛市野生种子植物区系的初步研究   总被引:9,自引:0,他引:9  
曾宪锋 《植物研究》1999,19(4):385-391
从科、属二个层次对秦皇岛市植物区系进行了统计分析,得出如下结论:(1)植物区系丰富,计有野生种子植物122科,513属,1093种;(2)区系主要是温带性质,具有与亚热带--热带区系的过渡性;(3)特有程度低。特有科无;中国特有属7个,本地区特有属无。  相似文献   

9.
杭州西湖风景区外来杂草的调查研究   总被引:3,自引:0,他引:3  
通过野外调查和文献资料的整理分析,确定杭州西湖风景区有外来杂草56种,隶属于21科44属。对西湖风景区外来杂草的种类组成、来源、分布特点进行分析,结果表明:(1)种类较多的科是菊科、苋科、豆科;(2)原产地以来源于北美洲的最多;(3)容易入侵地表裸露较大的生境;(4)发生具有季节差异;(5)种类、分布上呈动态变化。并就外来杂草近二十至三十年的变化进行了讨论。  相似文献   

10.
黑龙江鹤北地区维管束植物的区系分析   总被引:4,自引:0,他引:4  
张捷  胡秉坤  杨逢建  徐辉 《植物研究》2001,21(3):360-364
鹤北地区共有维管植物110 科, 412 属, 978 种, 其中蕨类植物有14 科18 属41 种, 裸子植物只有1 科4 属6 种, 被子植物有95 科390 属931 种。其植物区系成分特征为:(1)植物种类繁多;(2)区系成分丰富;(3)单属科和单种属较多;(4)存在许多孑遗种;(5)区系主要是北温带性质, 具有"南北混合型"特征。  相似文献   

11.
Cultural competence is used (often implicitly) to make decisions in human service settings. When therapists make decisions about whether or not a particular service will be offered, they place themselves in a position where their own competence can be judged. Using narrative data on independence and the elderly, we apply Edgerton's idea of the cloak of competence to demonstrate this doubling effect.  相似文献   

12.

Background

Despite strong recommendations to involve family social support in hypertension control, few questionnaires have been designed to measure family support in Chinese patients. The Chinese Family Support Scale is a self-rated questionnaire that assesses family support over a 6-month period.

Methods

A total of 282 patients with hypertension participated in this study and 136 of them completed the questionnaire twice within an interval of two to three weeks. Exploratory factor analysis was conducted to assess the structural validity of the scale. Concurrent validity was determined by measuring the correlation between the Chinese Family Support Scale, and Hospital Anxiety and Depression Scale using the Sperman’s Correlation Coefficient. Cronbach’s alpha and intraclass correlation coefficients were employed to evaluate the internal and test-retest reliability of the scale.

Results

Exploratory factor analysis revealed a three-factor solution accounting for 62% of the total variance. The three underlying sub-scale dimensions were kinship, nuclear family, and social resources. Significant correlation (r=-0.266; p<0.01) was found between the depression subscales of the Hospital Anxiety and Depression Scale and the extent of support perceived by the patients as measured by the Chinese Family Support Scale. The Chinese Family Support Scale had an acceptable internal consistency (Cronbach’s alpha = 0.84) and test-retest reliability (intraclass correlation coefficient = 0.82).

Conclusion

The study provides preliminary evidence that the12-item Chinese Family Support Scale is acceptable, valid and reliable for measuring the perceived family support in hypertension patients. It is a promising tool which can be easily incorporated into epidemiological surveys.  相似文献   

13.
OBJECTIVE--To investigate the current problems and needs of terminally ill cancer patients and their family members, and to discover their views of hospital, community, and support team services. DESIGN--Prospective study of patients and families by questionnaire interviews in the patients'' homes. SETTING--Inner London and north Kent (London suburbs). SUBJECTS--65 Patients, each with a member of their family or a career. MAIN OUTCOME MEASURES--Ratings of eight current problems and ratings and comments on three services-hospital doctors and nurses, general practitioners and district nurses, and the support team staff-obtained after a minimum of two weeks'' care from palliative care support teams. RESULTS--Effect of anxiety on the patient''s nearest career. and symptom control were rated as the most severe current problems by both patients and families; a few patients and families identified other severe problems. Families'' ratings of pain control, symptom control, and effect of anxiety on the patient were significantly worse than the patients'' ratings (p less than 0.05). Support teams received the most praise, being rated by 58 (89%) patients and 59 (91%) of family members as good as excellent. General practitioners and district nurses were rated good or excellent by 46 (71%) patients and 46 (71%) family members, but six (9%) in each group rated the service as poor or very bad, and ratings in the inner London district were significantly worse than those in the outer London district. Hospital doctors and nurses were rated good or excellent by 22 (34%) patients and 35 (54%) of family members, and 14 (22%) patients and 15 (23%) family members rated this service as poor or very bad. Negative comments referred to communication (especially at diagnosis), coordination of services, the attitude of the doctor, delays in diagnosis, and difficulties in getting doctors to visit at home. Family members were more satisfied with the services than were patients. CONCLUSIONS--Palliative care needs to include both the patient and family because the needs of the family may exceed those of the patient. Support teams and some hospital and community doctors and nurses met the perceived needs of dying patients and families, but better education and organisation of services are needed.  相似文献   

14.
Begum H 《Bioethics》1993,7(2-3):218-223
This presentation began with at least three biases: (i) Acceptance of a secular approach to the problem of artificially controlling human reproduction; (ii) acceptance of an absolute egalitarian position in matter of choices and applications of family planning methods; and (iii) acceptance of the view that a small family gives women more opportunities to flourish as humans. The conclusion of the presentation is: though in implementing family planning programmes much deviation from the egalitarian principle could be found, in reality the implementation itself does bring about some opportunities for women to enhance their position in society. Undoubtedly the malpractices in family planning programmes cause death and miseries to women. But, until better methods are invented for both male and female sexes to replace the harmful ones and the male members of the society feel equal responsibility in matters of controlling reproduction, women have now no other choice but to accept the lesser evil.  相似文献   

15.
A new type of learning algorithms with the supervisor for estimating multidimensional functions is considered. These methods based on Support Vector Machines are widely used due to their ability to deal with high-dimensional and large datasets, and their flexibility in modeling diverse sources of data. Support vector machines and related kernel methods are extremely good at solving prediction problems in computational biology. A background about statistical learning theory and kernel feature spaces is given including practical and algorithmic considerations.  相似文献   

16.
We queried 101,951 white, Hispanic, black, Asian, American Indian (i.e., American Indian or Alaska Native in the United States and North American Indian, Metis, or Inuit in Canada) and Pacific Islander (including Native Hawaiian) adults who agreed to be genotypically and phenotypically screened for hemochromatosis as part of the Hemochromatosis and Iron Overload Screening (HEIRS) study about their views on sharing genetic test information with family members. Multiple logistic regression (adjusting for study site, age group, race/ethnicity, preferred language, gender, education group, income group, SF-36 General Health and Mental Health subscales, perceived benefits and limitations of genetic testing, and belief that genetic testing is a good idea) evaluated independent predictors of responding "Strongly Agree" or "Agree" versus "Disagree" or "Strongly Disagree" to the statement "Information about a person's genetic risk should be shared with family members". Agreement that genetic risk information should be shared with family members was high (93% in the overall sample of 78,952 who answered this question), but differed among racial/ethnic groups. Hispanics were significantly less likely to agree that genetic test information should be shared with family members (i.e., 88% versus 92% or more among all other ethnicities). The relationship of perceived limitations and benefits of testing, gender, and age group to the belief that information should be shared differed among racial/ethnic groups, with Spanish-preferring Hispanics being the most different from other subgroups.  相似文献   

17.
Substituted (thio)hydantoins (2-thioxoimidazolidinones and imidazolidinediones) were reported as new potential reversible inhibitors of fatty acid amide hydrolase (FAAH). Their binding mode to FAAH was explored to rationalize their activity and give idea to design highly active inhibitors. Starting from the crystal structure of one of these molecules, docking studies provide us with rational basis for the design of new inhibitors within the thiohydantoin family.  相似文献   

18.
Restriction-modification (R-M) enzymes are classified into type I, II, III, and IV, based on their recognition sequence, subunit composition, cleavage position, and cofactor requirements. While the role of S-Adenosyl-L-methionine (AdoMet) as the methyl group donor in the methylation reaction is undisputed, its requirement in DNA cleavage reaction has been subject to intense study. AdoMet is a prerequisite for the DNA cleavage by most type I enzymes known so far, with the exception of R.EcoR124I. A number of new type II restriction enzymes belonging to the type IIB and IIG family were found to show AdoMet dependence for their cleavage reaction. The type III enzymes have been found to require AdoMet for their restriction function. AdoMet functions as an allosteric effector of the DNA cleavage reaction and has been shown to bring about conformational changes in the protein upon binding.  相似文献   

19.
This article focuses on the connection between three forms of diversity – religious, ethnic, and linguistic – and family values. The article builds on the idea that diversity challenges social identity and people react by returning to traditional family values in order to protect their social identity and the in-group culture. The paper aims at contributing to the sociological debate about the effect of diversity on social life and investigates how different types of diversity connect with traditional family values because individuals want to protect their in-group culture that is mainly transmitted within family. The paper tests the research hypotheses employing multilevel regression models and using data from the ISSP IV from 2012. Religious diversity associates with traditional attitudes regarding marriage and gender roles, ethnic diversity goes together with lower support for marriage, but has no connection with attitudes towards gender role, while linguistic diversity is not associated with attitudes family values.  相似文献   

20.
Geranyl diphosphate synthase catalyzes the condensation of isopentenyl diphosphate with dimethylallyl diphosphate to give a C(10) compound, geranyl diphosphate, which is a precursor of all monoterpenoids. However, the gene has not been isolated from any organisms. To examine the possibility that geranyl diphosphate synthase has evolved from a common ancestor of the prenyltransferase family and to predict the active site structure, we tried to convert Bacillus stearothermophilus farnesyl diphosphate synthase to geranyl diphosphate synthase, according to our previous findings. Several mutated farnesyl diphosphate synthases that have single amino acid substitutions before the first aspartate-rich motif were constructed. A mutated enzyme that has the replacement of serine by phenylalanine at the fourth position before the motif exclusively produced geranyl diphosphate when dimethylallyl diphosphate was used as the primer, and hardly accepted geranyl diphosphate as a primer, indicating that this mutation causes the conversion to geranyl diphosphate synthase. This result supports the idea that the product specificities of all members of the E-prenyltransferase family are mainly defined by a few structural features: the amino acids at the fourth position and the fifth position before the first aspartate-rich motif, and the insertion of two amino acids in the motif. This suggests that natural geranyl diphosphate synthases might have an active site structure similar to that of the mutated enzyme.  相似文献   

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