Morphological and genetic differences of Trypanosoma in some Chinese freshwater fishes: difficulties of species identification

Blood smears and purified trypanosome from freshwater fishes yellow catfish (Pseudobagras fulvidraco) and common carp (Cyprinus carpio) captured from Niushan Lake, Hubei Province were examined to determine whether all of their trypanosomes were Trypanosoma pseudobagri, a species of supposed host specificity and widespread existence across China. Trypanosomes occurred in 16/16 blood smears, and morphometric character analysis of trypanosomes from these smears showed that there were three morphospecies, Trypanosoma sp Carpio, T. sp Pseudobagri, and T. sp. 18S rDNA sequences of trypanosomes from 16 samples revealed three genetic groups among these fish trypanosomes. Group 1 was from C. carpio containing T. sp Carpio; groups 2 and 3 were from P. fulvidraco containing T. sp Pseudobagri and T. sp, respectively. The high similarity of morphometric characters and 18S rDNA sequences showed that T. sp Carpio and T. siniperca probably were the same species. T. sp Pseudobagri was the first occurrence in China. Sequence comparison showed that T. sp Pseudobagri sequence was most similar to that of clone Marv, whereas T. sp sequence differ from those of T. sp Carpio and T. sp Pseudobagri by 5.4 and 5.8%, respectively, and tentatively identified as T. pseudobagri. It was concluded that three species of trypanosomes, at least three genotypes occur in Niushan Lake fishes, and P. fulvidraco in this region appear to contain both types, although the identification of T. pseudobagri remains a problem.

本科实习男护生压力源、应对方式与心理健康关系的研究

Objectives:To investigate stressor and stress level,coping styles and mental health of male nursing undergraduates in clinical practice;To find out the factors that influence mental health of male nursing undergraduates in clinical practice and to put forward some suggestions to improve the mental health status of male nursing undergraduates. Methods: After doing many literaturere search both at home and abroad,I gather further consulting many nursing undergraduates in clinical practice,Finally I formulate the “Nursing Student's Clinical Stressor Scale”.80 male nursing ungraduates from Bengbu Medical Colledge were recruited. While 140 female nursing ungraduates who were in clinical practice in the same period of time were taken as a comparative group.The following questionnaire package including a background questionnair,Nursing Student's Clinical Stressor Scale NSCSS,Simplified Coping Style Questionnaire SCSQ,The Symptom Checklist 90 SCL-90 were distributed and collected together in the 14th week during the clinical practice.Of the 220 questionnaires were distributed and 198 were found to valid,the valid callback rate was 92%.The endudeed 77 were male and 121 were female .Statistices analysis was performed by SPSS13.0 and AMOS5.0 software. Results： 1.25% of male nursing undergraduates had a higher level of stress, mainly from employment,major,working nature,working contents and so on.Compared with female nursing undergraduates,male nursing undergraduates underwent a higher pressure in the employment and the profession aspect,but lower in their insufficient knowledge and ability.There was a significant negative correlation between the male undergraduates’ stress level and their satisfaction degree to clinical nursing teaching and the professional title of the clinical teachers,but it was positively correlated with their family monthly income. Stress level of female nursing undergraduates positively related with the number of children in their families,but negatively correlated with their family monthly income; 2.Male nursing undergraduates' coping style both positive and negative coping styles were adopted by male nursing undergraduates but mean at while positive coping styles.The positive coping styles adopted by male nursing undergraduates were significantly lower than that adopted by female nursing undergraduates; 3.The scores of depression,interpersonal sensitivity and anxiety in male nursing undergraduates were significantly higher than those of the nationwide youths norm.Alist all subscales scores of male nursing group were more than those of female nursing undergraduates except for fear subscale. Mental health of male nursing undergraduates was inversly correlated with the professional title of the clinical teachers and satisfaction of their majors; 4.Among male nursing undergraduates,the total score of stress and most subscale(except working nature and working contents,employment)scores of stress were positively correlated with the negative coping styles.The scores of stress level was positively correlated with the scores of SCL-90,Negative coping styles was positively correlated with the scores of SCL-90 among male nursing undergraduates,while positive coping styles were inversly correlated with most subscales(except phobic,paranoia,psychoticism)scores of SCL-90. Conclusions： 1.25% male nursing undergraduates have a higher level of stress,which is from employment, profession,working nature and working contents,financial difficulties and so on.The coping styles adopted by male nursing undergraduates were mainly positive coping styles.The mental health of male nursing undergraduates were lower; 2.Different genders have significant differences between stressors, coping style and mental health; 3.Stress,coping style,satisfaction degree to clinical nursing teaching and the professional title of the clinical teachers are predietors of mental health among male nursing undergraduates.

中学生抑郁和素质、压力、环境因素的关系及其整合模型研究

As a kind of mood, depression is one of the emotions which people experienced usually. Depressive disorder is one of the common mental diseases. There are about 100 million people in the world be disturbed by depression every year. So it is long history that depression is investigated widely in medicine, psychology, and sociology. There are many theorial problems remain to be solved. Viewed from latest vocuments, the development of depression theory is tending to become more complicated. Most of the prior depression theory focused on relation between one factor and depression. Because depressed individuls have various characteristics and factors that cause depression are different, and each factor can explain only part of depression variance, these prior depression theories are defected. As the knowledge about depression accumulated, the view that depression be caused by multifactor is clearer. There is tendency to integrate these cooperational factor into a model while developing a depression theory. In the present study, depression status of 1625 middle school students from junior 1 to senior 3 are measured using Depression Scale of Middle-school Student which is developed by ourselves. From approach of depressive mood, the present study explored depressive diathesis including attributional style, personality, coping style, and self. The relation among depressive diathesis, stress and depression is analysed. The relation between depression and school life adaptation, depression and cohesion, adaptation in family are also analysed from environmental view. At last, relation among environment, stress, depressive diathesis is examined by using covariance structure modelling. Synthesizing the results from the present study, the following conclusions were drawn: (1) There is grade-characteristics in development of depression in middle school students. Depression degree increased with grade. The main reason may be that the stress middle-school students experience increase and self-acceptance decrease with grade; (2) High depressive diathesis is different from low depressive diathesis. the features of high depressive diathesis are that attributing failure to ability or background, low capacity for status, low sociability, low independence, low self-blame, more illusion. The features of low depressive diathesis are that not attributing failure to ability or background, high capacity for status, high sociability, high independence, high self-acceptance, while facing difficulties, using problem-resolving coping strategy, less self-blame, less illusion. Individuals who have high depressive diathesis showed serious depression, and individuals who have low depressive diathesis showed light depression; (3) Depressive diathesis had accumulative effect on depression. More low depressive diathesis, more light is depression. More high depressive diathesis, more serious is depression; (4) Depressive diathesis can predict present depression and future depression. Predicting present depression is more effective than predicting future depression; (5) Individual who has different depressive diathesis experiences different level of stress. Higher the depressive diathesis individual has, higher stress he will experience. Lower the depressive diathesis individual has, lower stress will he experience; (6) There is correlation between life event pressure and depression. Life event pressure can predict a part of variance of depression. Life event pressure has accumulative effect on depression. More life event and higher life event pressure, more serious depression individual will experience; (7) There exits high correlation between depression and school life adaptation which can predict depression; (8) There is high correlative relation between depression and cohesion, adaptation in family which can predict depression; and (9) Environment have more effect on diathesis than on stress. Diathesis has more effect on depression than stress does. The past depression can predict future depression. This study had enlarged the domain of depressive diathesis such as attributional style, personality, coping style, and self, which are analysed wholly. This study had also enriched the connotation of diathesis=stress theory. Above two aspects are theoretical significance of the study. This study provide a framework of mental health educational curriculum in high school and provide the guideline for prevention and cure of depression. It is the practical significance of this study.