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1.
一品红试管苗移栽驯化期叶片的解剖结构变化   总被引:3,自引:0,他引:3  
对一品红试管苗移栽驯化,同时研究了驯化过程中叶片结构的变化,结果表明,一品红在珍珠岩基质中成活率达98%,随着移栽时间的延长,表皮细胞增大,排列紧密;叶肉细胞间隙减小,栅栏组织细胞长度增加,主脉增厚,导管数目增加,保水,输水和抗逆能力增强。  相似文献   

2.
The Color of My Skin is an instrument developed to assess children's internalized idea (abstraction) of the color of their skin; their satisfaction with that color; the desire, if any, to change the color of their skin; and their affect regarding their skin color. The assessment is part of a questionnaire utilized in a 3-year longitudinal study that examines psychosocial development, physical health, and behavioral adjustment of Puerto Rican children (N = 257) reared in the Greater Boston area. The results demonstrate that children's internalized representation of their skin color is a construct that can be reliably and validly measured. The children's ratings of their skin color were not associated with their sex, school grade, ethnic identity, the child's or the parent's nativity, or the racial or ethnic compositions of 3 social contexts: their neighborhood, their classmates, and their closest friends. Puerto Rican children did not show a preference for light-colored skin. Moreover, there were no significant differences in self-esteem based on the child's self-reported skin color. The lack of association between self-esteem and skin color was interpreted in light of a developmental tendency prevalent in early to middle childhood to place a positive value on different aspects of one's self. Whereas almost all children (96%) reported being happy or very happy with their color, 16% of the children would like to change their skin color if they could (51% to a lighter and 46% to a darker color).  相似文献   

3.
The Color of My Skin is an instrument developed to assess children's internalized idea (abstraction) of the color of their skin; their satisfaction with that color; the desire, if any, to change the color of their skin; and their affect regarding their skin color. The assessment is part of a questionnaire utilized in a 3-year longitudinal study that examines psychosocial development, physical health, and behavioral adjustment of Puerto Rican children (N = 257) reared in the Greater Boston area. The results demonstrate that children's internalized representation of their skin color is a construct that can be reliably and validly measured. The children's ratings of their skin color were not associated with their sex, school grade, ethnic identity, the child's or the parent's nativity, or the racial or ethnic compositions of 3 social contexts: their neighborhood, their classmates, and their closest friends. Puerto Rican children did not show a preference for light-colored skin. Moreover, there were no significant differences in self-esteem based on the child's self-reported skin color. The lack of association between self-esteem and skin color was interpreted in light of a developmental tendency prevalent in early to middle childhood to place a positive value on different aspects of one's self. Whereas almost all children (96%) reported being happy or very happy with their color, 16% of the children would like to change their skin color if they could (51% to a lighter and 46% to a darker color).  相似文献   

4.
噬菌体和它们的宿主菌组成了地球上教目最庞大的微生物种群,噬菌体靠寄生宿主菌来扩增繁衍。但在漫长的进化中,噬菌体与宿主菌间不单是捕食关系,它们间还形成了复杂的相互对抗机制,其中抵抗防御机制的抗防御机制也会促使抗.抗防御机制的产生。从生态学角度来看,噬菌体和宿主菌间的共进化保持着动态平衡。本文综述近年来这一领域的研究,为更清楚地了解噬菌体与宿主菌间的关系和应用提供了参考。  相似文献   

5.
The study of the properties of C. diphtheriae adhesins revealed the absence of their thermostability, which suggested the protein nature of these adhesins. C. diphtheriae also showed pronounced mannose-resistant hemagglutinating activity, as this activity remained unchanged even in the presence of d-mannose. The comparison of the adhesive activity of C. diphtheriae with their phage and corycine sensitivity revealed essential differences between these macroorganisms in the degree of their adhesiveness. The phage lysability and corycine sensitivity of C. diphtheriae strains, determined by the properties of their surface structure, correlated with the degree of their activity.  相似文献   

6.
West African dwarf nanny goats and their twin-born kids were tested to determine their behavioural response to separation and their mutual recognition during the first 48 h post-partum. Does and their kids were given scores ranging from 1 to 5, depending on how they performed in the tests. Animals that showed maximum response and recognition ability were given a score of 5, while those with minimum response and recognition ability scored 1. The kids were prevented from sucking 2 h prior to the tests, which were carried out at 18, 24, 36 and 48 h post-partum. Chi-square procedure was used to determine whether age, sex and birthweight of kids as well as hours post-partum and parity of dams had any effect on these post-partum behaviours. Out of 48 twin-born kids tested, 32 (67%) responded actively to separation from dams (i.e. had scores of 3 or more). The age, sex and birthweight of kids did not significantly affect (P>0.05) their response to separation from their dams. The hours post-partum and the parity of does also did not affect their response to separation from their kids. The dam recognition ability of twin-born kids was very poor. Out of a total of 48 kids tested, only 17 (35%) were able to recognize their dams (i.e. had scores of 3 or more). Even at 36 h, only four out of 14 (26%) could recognize their dams. It was only at 48 h that the majority of kids tested (i.e. 75%) successfully identified their dams. At 48 h, the dam recognition ability of kids was significantly better (P<0.05) than that of 18-h-old kids. Sex and birthweight of 24-48-h-old twin-born kids did not significantly affect (P>0.05) their ability to recognize their dams. The majority of does tested (i.e. 20 out of 24) were able to recognize their twin-born kids. The hour post-partum and parity of does did not significantly affect (P>0.05) their kid recognition ability.  相似文献   

7.
The study of the growth of the yeasts Rhodotorula rubra, Saccharomyces cerevisiae, and Debaryomyces vanriji at elevated temperatures and their survival after transient lethal heat shock showed that the ability of these yeasts to grow at supraoptimal temperatures (i.e., their thermoresistance) and their ability to tolerate lethal heat shocks (i.e., their thermotolerance) are determined by different mechanisms. The thermotolerance of the yeasts is suggested to be mainly determined by the division rate of cells before their exposure to heat shock.  相似文献   

8.
The specific features of the fatty acid composition of phospholipid carriers obtained from raw materials of vegetable and animal origin were studied. Differences in the enrichment of phospholipids of different origin with polyene fatty acids were shown. The method for obtaining fluoroliposomes incorporating such components as phospholipids of mouse organs, egg yolk, etc. were proposed. The study proved that the homology of the lipid base of liposomes facilitated their binding by tropic organs and more rapid liberation of the blood stream from them. The selection of lipid carriers and their sources was determined by their uniformity, morpho-functional importance, phospholipid and fatty acid composition, as well as their homology as regards their composition features.  相似文献   

9.
The case records of 100 patients over the age of 60 at the time of their admission to a state mental hospital in California were evaluated, using rigid criteria to determine whether the precipitating cause for their state hospitalization was due to a deterioration of their mental state or a change in their socio-environmental milieu. The results of the study indicated that 77 per cent of these patients were in hospital because of a deterioration in their own mental state while 23 per cent were there because of a deterioration in their socio-environmental milieu. The data also were indicative that the proportion of patients put in hospital because of a deterioration in their socio-environmental milieu might conceivably be higher than 23 per cent if subtle changes in family attitude towards the patient could be adequately evaluated.  相似文献   

10.
Function and structure of inherently disordered proteins   总被引:2,自引:0,他引:2  
The application of bioinformatics methodologies to proteins inherently lacking 3D structure has brought increased attention to these macromolecules. Here topics concerning these proteins are discussed, including their prediction from amino acid sequence, their enrichment in eukaryotes compared to prokaryotes, their more rapid evolution compared to structured proteins, their organization into specific groups, their structural preferences, their half-lives in cells, their contributions to signaling diversity (via high contents of multiple-partner binding sites, post-translational modifications, and alternative splicing), their distinct functional repertoire compared to that of structured proteins, and their involvement in diseases.  相似文献   

11.
For the first time V. fluvialis strains were detected on the territory of the USSR. The taxonomic position of these vibrios was determined by their nucleotide DNA composition (the content of guanine + cytosine was 49.3-51.0 mole%) and the characteristic features of their phenotype. The individual features of the strains consisted in their capacity for agglutination with cholera antisera, groups 01 and Inaba, in diagnostic dilutions in the presence of differences in genomes and phenotypes with cholera vibrios. Molecular hybridization DNA-DNA also gave no confirmation of their relationship to cholera vibrios (23-26% homology). The comparative study of V. fluvialis strains from the USSR and other countries by a broader set of their phenotypical signs confirmed their identity.  相似文献   

12.
Moshe Shokeid 《Ethnos》2013,78(2):219-238
Ethnographic texts preserve the historicity and losses of both the people observed and their observer. However, anthropologists rarely inform their readers about the circumstances of their departure from a fieldwork project. Without formally indicating the completion of their research goals, they usually move on to a new field and cease publishing on their former site. This procedure seemed natural enough when anthropologists conducted their studies in remote Third World locations. The constraints of distance, time, and budget made that abrupt separation seemingly inevitable and self-explanatory. But when anthropologists choose fieldwork sites that are close to home or easy to revisit, or conduct long-term research, their relationships with their subjects change radically, both during fieldwork and during the stages of writing and publishing the ethnographic text. Consequently, their eventual exit from the field involves a different process. Based on the experience of a fifteenyear engagement in the study of a gay synagogue in New York, this paper explores the latter process. The issue of exiting presents a methodological, emotional, and ethical problem meriting serious professional consideration.  相似文献   

13.
14.
The aims of the study were to analyse the sport activity and eating habits of obese people in their childhood and adulthood. The research was underpinned by a survey questionnaire containing 37 variables which was completed by 71 people attending the obesity programme. The frequencies and contingency tables were calculated, whereas statistical significance was established at a 5% significance level. The analysis of the results showed that more than one-half of the survey respondents joined the obesity programme primarily for reasons of health and well-being. Most obese people did not engage in any organised sport activity in their childhood, nor did most of their parents. The respondents practiced sport in their childhood to a greater extent if their parents were also physically active and if they guided and encouraged their children. No less than one-third of the respondents were overweight in their childhood, of whom two-thirds did not participate in any organised sport activity. The majority of the respondents (85.9%) are currently engaged in an organised sport activity in their adulthood, mainly due to their participation in the weight reduction programme; most of them practice sport twice a week. Their eating habits are encouraging; the share of skipped meals is considerably lower and practically negligible compared to that in childhood. It has to be emphasized that most of them are of opinion that obese people have difficulties finding expert information on obesity, nutrition and sport activities as well as weight management centers and institutions.  相似文献   

15.
The purpose of this study was to explore professional development themes in experienced strength and conditioning coaches. Strength and conditioning coaches (N = 15, mean age = 34.3 years, SD = 5.2 years) with 11.4 (SD = 4.9) years experience working with elite, professional, or talented athletes were interviewed about their professional development. The interviews were transcribed verbatim and content analyzed. Over time, subjects' service-delivery practices became more flexible and client driven. Their role understanding also broadened to include various dimensions, such as the need to consider various stakeholders and the value of good relationships with athletes. The subjects shifted from relying on external justification for professional decision making to their experience-based knowledge. The subjects believed athlete work experience, interactions with senior strength and conditioning coaches and other colleagues, the professional literature, and nonprofessional experiences, such as their own athletic experience and sales or managerial training, were the primary influences on their professional development. Typically, the subjects experienced anxiety about their competence, both early in their careers and when working in new contexts or with new athlete groups, but over time, they developed increased confidence. In addition, the subjects experienced reduced narcissism over time about the control they had over athletes and their competitive results. The current results provide information about the characteristics of effective strength and conditioning coaches, the ways they develop their competencies to help athletes, and the emotions they experience throughout their careers. These results may help strength and conditioning practitioners in planning and optimizing their professional development and effectiveness with athletes.  相似文献   

16.
To investigate the regulation of the biosynthesis of ergot alkaloids by end products, the effect of exogenous agroclavine-1 and epoxyagroclavine-1 on their accumulation byP. sizovae was studied. The added alkaloids stimulated considerably their own biosynthesis depending on their concentration and time of introduction. The stimulating effect of both alkaloids and products of their degradation was suggested. Exogenous agroclavine-1 and epoxyagroclavine-1 changed the relation between the quantities of intra-and extracellular alkaloids, thus pointing to their possible influence on the transport processes.  相似文献   

17.
G A Golden  M Brennan 《CMAJ》1995,153(9):1241-1245
In spite of prohibitions against the sexual involvement of physicians with their patients, erotic feelings sometimes arise in physician-patient relationships. The authors suggest that physicians can protect themselves and their patients from the harm that results from sexual involvement by establishing behavioural limits for their professional relationships, responding to patients'' sexual overtures in a firm but nonjudgemental manner, examining their own sexual feelings rationally, seeking consultation if necessary and terminating the relationship if sexual feelings are compromising patient care. The challenge for physicians is to acknowledge that sexual feelings can arise and to manage such feelings for the sake of their own and their patients'' well-being.  相似文献   

18.
The importance of hydrogen bonding studies lies in their structural, biological and medicinal applications. Non-conventional hydrogen bonds are weak, but are found to play an important role in biological molecules. In view of their importance,a study of the aromatic hydrogen bonds in peptides with aromatic amino acid side chains was carried out. The results indicate a reasonable probability for their occurrence, thereby enumerating their distinct features.  相似文献   

19.
We present an hypothesis, derived from the zootype concept of Slack, Holland and Graham. The main point of this hypothesis is to postulate that the primordial function of the zootype genes is to design an appropriate neuronal network in bilaterian animals, by controlling the genes involved in the specificity of the axon pathways. This would be the primary function of the zootype genes in development and their primitive function in evolution. The hypothesis is discussed in view of the current knowledge on the Hox genes, their evolution, their genomic organisation, their expression and their targets.  相似文献   

20.
Monoclonal antibodies have reached the stage of therapeutic agents, mostly in oncology, as illustrated by their wide use in lymphoma, breast cancer or colorectal cancer. The unravelling of their mechanisms of action and their interactions with their cellular receptors allows us to engineer new classes of therapeutic antibodies with increased efficacy. The identification of some of the tumour escape mechanisms may also help to define new approaches for patient selection and immunomonitoring. The present review addresses these various aspects.  相似文献   

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