广西苦丁茶的生产现状及无公害栽培技术探讨

广西苦丁茶生产区主要在大新县和天等县,种植面积约3 000 hm2,年产茶叶约700 t。生产过程中存在对农药和化肥的过份依赖、产品的重金属和农药超标等问题,需要通过无公害栽培来提高产品质量。该文从茶园选择、种植、土壤管理和施肥、茶树修剪和茶叶采摘、病虫害防治等方面对苦丁茶的无公害栽培技术进行了初步探讨。     

Ways of Investigating Motivation for Learning in Schoolchildren

The tasks of universal education in our country and the cultivation of an active, comprehensively developed personality in the young people of communist society call for further studies of the possibilities of mobilizing the "human factor," the reserves of mental development, in schoolchildren. The new tasks confronting contemporary education (not just to increase pupils' knowledge quantitatively but also to teach them ways to acquire that knowledge independently [1]) and the practical problems of classroom instruction (overburdening of pupils in some subjects, diminished interest in school at certain periods, e.g., at the transition from primary to secondary school) necessitate psychological study of ways to stimulate the activity of schoolchildren and to cultivate in them an active, internalized interest in schoolwork.     

Diazonium inactivation in simultaneous-coupling and product inhibition in post-coupling azo-techniques for demonstrating activity of acid hydrolases

In this communication results are presented of an investigation in which the activity of the hydrolytic enzymes acid phosphatase, beta-glucuronidase, non specific arylesterase, microsomal arylsulphatase, beta-galactosidase, beta-N-acetylglucosaminidase, acid alpha-glucosidase and aminopeptidase M are demonstrated in tissue sections with simultaneous- and post-coupling azo-techniques. Semipermeable membrane techniques are used to hamper enzyme diffusion during the incubation period. From the histochemical and biochemical findings it appeared that an advantage of the post-coupling techniques over the simultaneous-coupling techniques is that inactivation of the enzymes by the coupling reagents is avoided. On the other hand post-coupling techniques are subject to product inhibition. With kinetic inhibition studies it is found that for microsomal arylsulphatase and non-specific arylesterase this product inhibition is non-competitive. This product inhibition may be a problem for histochemical quantitative post-coupling techniques for the determination of acid hydrolase activity.     

Problems in the Psychology of Activity

My purpose today is to sum up a number of the postulates concerning activity as it is used in psychology, without introducing any new ones; and I shall do this with the following in mind. Until now I have used a system of concepts I proposed earlier with respect to an analysis of activity; of course, I should like to work out a position, first and foremost my own, on this system, and to reexamine it. On the other hand, I should like to pose a number of questions, such as: Is this system of concepts of any significance, i.e., is it able to work in psychology? Obviously, this system must be developed, which essentially has not been done in recent years. This system of concepts is frozen, without any movement. I personally was quite alone in this respect. All movement takes place with regard to various problems contiguous with the problem of activity, some more, some less; but in my opinion, the concept of activity has been developed highly unsatisfactorily. That is why I thought I should try, today, to sum up very briefly what I think is important.     

Taste development from health education among schoolchildren: a two-year intervention study

It is necessary to develop a system of nutritional education which can be understood among schoolchildren who have not yet received a basic education. In the present study, we conducted an educational program for lower-grade schoolchildren, which contained dish selection, an agricultural experience, a cooking experience, and a lecture on digestive absorption. We evaluated the effect of this program on development by measuring taste sensitivity regarding sweet, sour, salty and bitter tastes. For the baseline period, there was no significant difference between the intervention school and the control school in each variable. At follow-up periods, both the intervention and the control schools showed an increasing sense of taste. In the intervention school, development of sensitivity to the sweet, the sour, and the bitter taste was significant. In the control school, development of sensitivity to the sweet and the bitter taste was significant. The increases in the sense of the sour and the bitter tastes and the sum of the four tastes for the intervention subjects were significantly larger than comparable values for the control subjects. These results suggest that the development of taste sensitivity is affected by nutritional education for lower-grade elementary schoolchildren.     

黑木耳代用料栽培关键技术研究

针对目前黑木耳代用料栽培中存在的问题,结合吉林省东部地区资源及气候特点,系统地对黑木耳栽培技术进行研究。结果表明:黑木耳最适培养料装量为800g;在接种时间为3月10日、置于相同培养条件下,最适栽培时间为4月下旬至5月初;菌丝体培养最适温度20～25℃,初期略高;最适水分条件为采用间歇式供水,干湿交替;最适光照条件为全日光。     

Psychosocial adaptation to short stature - an indication for growth hormone therapy?

Although growth hormone does not clearly improve final height in non-growth-hormone-deficient children with short stature, it leads to a temporary acceleration of growth velocity. It is an ongoing discussion whether this effect supports psychosocial adaptation to short stature and therefore could be an indication for growth hormone treatment in children with short stature without growth hormone deficiency. We have reviewed recent literature concerning psychosocial consequences of short stature. Together with own data we can demonstrate that short people regularly adapt well to their height and have a good self-esteem. On the other hand, we focus on the problem that most studies on this subject suffer from methodical problems. A growth-related questionnaire that evaluates subjective and objective perceptions of being short in patients and peers is not at hand. As a consequence, psychosocial problems due to short stature have not been exactly classified yet and therefore do not represent an indication for growth hormone therapy.     

A case study in techniques of allocation.

A number of techniques for allocating an individual into one of two groups have been compared in a practical situation. On the basis of the answers to nine Yes/No questions it was necessary to allocate patients previously treated for thyrotoxicosis into those suspected to be hypothyroid and those thought to be euthyroid. Eight different methods have been applied to this problem and the main conclusion from the analysis is that seven of the techniques give broadly similar results, including the simple one of symptom counting. The other method, the multinomial, suffered from the need to estimate a large number of parameters on a relatively small set of data, and the resulting allocation rule performed badly in an independent sample.     

MICROALGAL BIOTRANSFORMATION OF STEROIDS1

Microbial biotransformation of steroids is not a new concept, but most studies in this field have focused on fungal and bacterial systems. Microalgae, despite their photosynthetic ability and immense biodiversity, have not received much attention in this aspect until recently. Since the publication of the first article on microalgal biotransformation of steroids about 20 years ago, there have been many reports describing different modifications, including hydroxylation, reduction, side‐chain degradation, and isomerization introduced by these microorganisms on estrane, androstane, and pregnane derivatives. On the other hand, the development of new large‐scale cultivation systems, the adaptation of existing fermentation techniques to microalgae, and the introduction of microalgal genetic manipulation methods have made these organisms promising candidates for a wide range of biotechnological processes, including biotransformations. In this review, we have summarized the steroid transformation patterns of several microalgal strains and present a perspective of the future trends in microalgal biotechnology, including the possibility of adapting relatively new techniques, such as organic media catalysis and cell immobilization, to this specific field.     

The Category of Age in the Psychology and Pedagogy of Development

Vygotsky's words, uttered about sixty years ago, may serve as a very special epigraph to the analysis that follows; they have not lost their meaning even today: "The problem of age is not only central to the whole of child psychology: it is the key to all questions of practice as well" [4. P. 260].

The key importance of the concept of age as a category in educational psychology has become obvious now, in light of the urgent need for a reorganization of education, a need to give it a developmental character. This category is just as important for a practice-oriented pedagogy, which can no longer be satisfied with simple study of individual phenomena in educational psychology; it must necessarily become a composite and, even more, a projective science, since it involves contriving complex, synthetic objects that bring together concrete studies, blueprints for educational systems, the programs and technology of continuous education throughout a person's entire life, and expert systems for evaluating and means for monitoring the effectiveness of such continuous education.     

Comparision of the sensitivity of detection of bacteria in human blood using classic culture methods and molecular techniques: PCR and FISH

Blood infections are one of the major problems of the contemporary medical care. Their detection depends strongly on sensitivity of the used microbiological methods. Widely applied classical techniques based on blood cultivation are time consuming and less sensitive. Therefore, it is necessary to search for new molecular tools to detect bacteria in blood directly taken from patient, like as PCR or FISH. In this paper we have proved that both PCR and FISH show very high sensitivity but due to various limitations their procedures need for further standardization before future application to routine diagnosis of blood infections.     

PHENOTYPIC CONSEQUENCES OF FORCING GERMINATION: A GENERAL PROBLEM OF INTERVENTION IN EXPERIMENTAL DESIGN

Many evolutionary and ecological studies of plants with seed dormancy are plagued by design problems related to seed germination. On the one hand, traits of interest, especially life history traits like early growth rate or time to flowering, may not be independent of dormancy phenotype. On the other hand, germination-inducing treatments are likely to affect these traits of interest. Consequently, researchers often have had to use confounded designs without information about the consequences. To examine this problem, we studied how early growth in California poppy (Eschscholzia californica) is affected by treating seeds with giberellic acid (GA) to stimulate germination. The dose used was sufficient to slightly but significantly advance emergence time in treated seeds, but it appeared to cause variable growth responses among treated seeds. Experiments using GA to stimulate germination may thus be misleading, at least for the populations and dose studied. Perhaps more importantly, the experimental and statistical approach we used can be employed to study the effects of this confounded design for other doses and species.     

Evaluation of Public Engagement Activities to Promote Science in a Zoo Environment

Scientists are increasing their efforts to promote public engagement with their science, but the efficacy of the methods used is often not scientifically evaluated. Here, we designed, installed and evaluated the educational impact of interactive games on touchscreens at two primate research centres based in zoo environments. The games were designed to promote interest in and understanding of primates and comparative psychology, as a scaffold towards interest in science more generally and with the intention of targeting younger individuals (under 16''s). We used systematic observational techniques and questionnaires to assess the impact of the games on zoo visitors. The games facilitated increased interest in psychology and science in zoo visitors, and changed the knowledge of visitors, through demonstration of learning about specific scientific findings nested within the games. The impact of such devices was greatest on younger individuals (under 16''s) as they were significantly more likely to engage with the games. On the whole, therefore, this study demonstrates that interactive devices can be successful educational tools, and adds to the growing body of evidence that conducting research on public view in zoos can have a tangible impact on public engagement with science.     

Kinetics of circadian band development in Neurospora crassa

The circadian rhythm of Neurospora crassa can be seen as a conidiation rhythm that produces concentric rings of bands (conidiating regions) alternating with interbands (non-conidiating regions) on the surface of an agar medium. To follow quantitatively this rhythm, densitometric analysis, gravimetric procedures, and video microscopy were employed. The circadian behavior of N. crassa is commonly monitored by cultivation in race tubes; in this work we report different growth kinetics during cultivation in conventional Petri dish cultures. Two different growth parameters were measured: total colony mass (true growth rate) and distance (colony radial expansion or hyphal elongation). Determinations of cellular mass revealed a dramatic circadian oscillation with a marked drop in growth rate during new interband formation followed by a sharp increase during the development of a new conidiation band. On the other hand, we found that the radial expansion of the colony previously reported to decrease periodically seemed unaffected by the circadian clock. Densitometric analysis showed no initial difference in the expanding margin of the colony, independent of whether that area was destined to be a band or an interband. The band areas increased rapidly in density for about 15 h whereas the interband areas maintained an equally rapid rate of increase for only 6h. The density of band areas kept increasing slowly for almost 40 h, along with an increase in the amount of conidia. Video microscopy showed the importance of cytoplasmic flow in colony development with continuous forward flow to support hyphal morphogenesis and reverse flow to support an extended period of conidiogenesis. Our results indicate that the circadian system of Neurospora can be expressed at the level of cellular mass formation, not just as the developmental conidiation rhythm.     

Prevalence of Intestinal Protozoans among Schoolchildren in Suburban Areas near Yangon,Myanmar

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area.     

Partial mixture model for tight clustering of gene expression time-course

Background  

Tight clustering arose recently from a desire to obtain tighter and potentially more informative clusters in gene expression studies. Scattered genes with relatively loose correlations should be excluded from the clusters. However, in the literature there is little work dedicated to this area of research. On the other hand, there has been extensive use of maximum likelihood techniques for model parameter estimation. By contrast, the minimum distance estimator has been largely ignored.     

Role of AMP-activated protein kinase in autophagy and proteasome function

In this work, we have examined the possible role of AMP-activated protein kinase (a key energy sensor) in regulating intracellular protein degradation. We have found that AICAR, a known activator of AMPK, has a dual effect. On one hand, it inhibits autophagy by a mechanism independent of AMPK activity; AICAR decreases class III PI3-kinase binding to beclin-1 and this effect counteracts and reverses the known positive effect of AMPK activity on autophagy. On the other hand, AICAR inhibits the proteasomal degradation of proteins by an AMPK-dependent mechanism. This is a novel function of AMPK that allows the regulation of proteasomal activity under conditions of energy demand.     

Modeling leaflet correction techniques in aortic valve repair: A finite element study

In aortic valve sparing surgery, cusp prolapse is a common cause of residual aortic insufficiency. To correct cusp pathology, native leaflets of the valve frequently require adjustment which can be performed using a variety of described correction techniques, such as central or commissural plication, or resuspension of the leaflet free margin. The practical question then arises of determining which surgical technique provides the best valve performance with the most physiologic coaptation. To answer this question, we created a new finite element model with the ability to simulate physiologic function in normal valves, and aortic insufficiency due to leaflet prolapse in asymmetric, diseased or sub-optimally repaired valves. The existing leaflet correction techniques were simulated in a controlled situation, and the performance of the repaired valve was quantified in terms of maximum leaflets stress, valve orifice area, valve opening and closing characteristics as well as total coaptation area in diastole. On the one hand, the existing leaflet correction techniques were shown not to adversely affect the dynamic properties of the repaired valves. On the other hand, leaflet resuspension appeared as the best technique compared to central or commissural leaflet plication. It was the only method able to achieve symmetric competence and fix an individual leaflet prolapse while simultaneously restoring normal values for mechanical stress, valve orifice area and coaptation area.