Set up and run an objective structured clinical exam.

Objective structured clinical exams are increasingly used as a way of assessing a range of clinical skills at both undergraduate and postgraduate level. To those planning to introduce such assessments, this article provides basic guidance on their development and structure and the personnel required. For those already using the assessments, our article may provide new ideas or be the impetus for an exchange of ideas. For those who are facing such formal assessment as candidates, we hope this article shows the efforts that are made to achieve the necessary structure and objectivity in this type of examination.     

壳斗科植物摘录(Ⅱ)

本文报道柯属Lithocarpus Bl。的新分类群,即17新种,7新变种,新名3,新组合5,对少好的种作了订正。属的中名取名为柯,并作简要的讨论。又文内提到的绝大多数的新种,早在1982年出版的《中国高等植物图鉴》补编Ⅰ里用分种检索的形式作了初报,但全部都是裸名。此外,尚有个别种更改其等级或归并。 本文引用的标本,除属华南植物研究所SCBI外均注明标本的保存单位(标术室缩写代号见植物分类学报20(2):252—256,1982)。     

Re-entry programs, from an anti-unconventional ex-offender

The purpose of this article seeks to question the relationship of higher levels of educational attainment and the ability for successful reintegration into mainstream society for the formerly incarcerated. Specifically this article highlights societal negligence for individual success of the formerly incarcerated, opting for a corporatized exploitation of those in the reentry process premised on the socially constructed label “ex-con.” Research surrounding labeling and reentry suggests once individuals are released from prison the social stigma experienced in society is a recipe for failure and reoffending. One way this emerges is in the form of hiring policies in corporate occupations, prohibiting the hiring of individual s convicted of a felony. Critical criminology suggests the class structure is in place for those in power to stay in power and keep those who are inferior in inferior social positions. Using both points of view as a framework, with the idea of corporate monopoly as a lens, allows for an untraditional critical perspective of the reentry process as a capitalist, for-profit industry. Questioning the role and intentions of reentry initiatives provides a general discussion for increasing success rates of those in the reentry process and reducing capital costs spent for incarceration. The specific focus of this article presents my experience of the reentry process.     

The development of a saccus vasculosus in Tilapia mossambica Peters and other cichlids

Observations are made on the development and the presence of a Saccus Vasculosus in Tilapia mossambica and other cichlids.
In those cichlids that do not possess a saccus vasculosus the development of this organ is apparently suppressed in a very early stage of life.
A saccus vasculosus is present in all those American and Indian cichlids that were investigated, but this organ was not found in cichlids indigenous to the African continent.     

Postponing or rejecting parenthood? Results of a survey among female academic professionals

The current surge in childlessness is often seen as an alternative lifestyle amidst growing pluralism and individualism. The results of this study indicate that several subgroups of childless women need to be differentiated: those who actively decide to forgo children in favour of other life pursuits and those who merely defer the decision. Both have accumulated a high degree of human capital in their education or career-building paths. Thus, the increase of a woman's time invested in education or career formation takes its toll on the time available for childrearing. A survey performed among female academics (N = 193) brought to light that among childless women, many merely mean to postpone motherhood until their career prospects are established. Differences between those who outwardly reject motherhood and those who defer the decision can be seen in a variety of job- and career-related aspects. However, due to misconceptions about fertility, many of those who merely intended to postpone children may inevitably end up 'involuntarily childless'. As this trend is most likely to increase in the near future, the resolution of this conflict will be an important milestone in the development of modern industrialized countries. As can be seen from this survey, financial benefits will not induce women to enter into motherhood. Rather, societal and infrastructural changes have to be brought about in order to induce women to enter into motherhood.     

Syringomyelia: A Clinical Review of 75 Cases

Records of 75 patients with syringomyelia are reviewed. Their clinical course fell into one of three main groups: (1) those with a long history of a steadily progressive disability; (2) those with a long history but little or no progression of their disability; and (3) those with a short, fairly rapid downhill course.On the basis of this study, x-ray therapy seems to be of little value in the treatment of this disease. Surgical treatment on the other hand appears to offer more hope for a selected group of patients who are progressing at the time of examination. In this group surgery is recommended (1) in the presence of a foramen magnum anomaly with signs and symptoms related to this deformity; (2) in the presence of a distended cord with pain and evidence of a spinal fluid block; and (3) when the possibility of an ependymoma exists.     

A hypothesis for DNA viruses as the origin of eukaryotic replication proteins

The eukaryotic replicative DNA polymerases are similar to those of large DNA viruses of eukaryotic and bacterial T4 phages but not to those of eubacteria. We develop and examine the hypothesis that DNA virus replication proteins gave rise to those of eukaryotes during evolution. We chose the DNA polymerase from phycodnavirus (which infects microalgae) as the basis of this analysis, as it represents a virus of a primitive eukaryote. We show that it has significant similarity with replicative DNA polymerases of eukaryotes and certain of their large DNA viruses. Sequence alignment confirms this similarity and establishes the presence of highly conserved domains in the polymerase amino terminus. Subsequent reconstruction of a phylogenetic tree indicates that these algal viral DNA polymerases are near the root of the clade containing all eukaryotic DNA polymerase delta members but that this clade does not contain the polymerases of other DNA viruses. We consider arguments for the polarity of this relationship and present the hypothesis that the replication genes of DNA viruses gave rise to those of eukaryotes and not the reverse direction.     

Cellular and molecular biology of glycosphingolipid glycosylation

Brain tissue is characterized by its high glycosphingolipid content, particularly those containing sialic acid (gangliosides). As a result of this observation, brain tissue was a focus for studies leading to the characterization of the enzymes participating in ganglioside biosynthesis, and their participation in driving the compositional changes that occur in glycolipid expression during brain development. Later on, this focus shifted to the study of cellular aspects of the synthesis, which lead to the identification of the site of synthesis in the neuronal soma and their axonal transport toward the periphery. In this review article, we will focus in subcellular aspects of the biosynthesis of glycosphingolipid oligosaccharides, particularly the mechanisms underlying the trafficking of glycosphingolipid glycosyltransferases from the endoplasmic reticulum to the Golgi, those that promote their retention in the Golgi and those that participate in their topological organization as part of the complex membrane bound machinery for the synthesis of glycosphingolipids.     

Differentiation and production of colony-stimulating factor induced by immunostimulants in a leukemia cell line

Immunostimulants from various microorganisms were tested on a myeloid leukemia cell line (Ml) for the ability to induce production of CSF and to cause differentiation of these cells. Based on their activities, the compounds were divided into two general classes: those inducing extensive cellular differentiation and those devoid of this effect. The stimulants which were active in this regard always produced large quantities of CSF, whereas those devoid of a differentiating effect did not cause CSF production. Even the potent stimulants had no effect on the D^? subline, in which the differentiation was not inducible.     

Smoking,Chronic Bronchitis,and Lung Cancer

A follow-up was carried out on 21,579 male mass radiography volunteers aged at least 40 who had been the subject of an earlier investigation in which their smoking habits and sputum production were recorded and the prevalence of lung cancer was determined after chest x-ray examination. During the follow-up period, which was a minimum of 36 months and a maximum of 56 months, 64 new cases of lung cancer were identified by cross checking records with the registers of the regional cancer registration bureau. A significantly higher incidence of lung cancer was found in those with chronic bronchitis than in those without this disease. In the smoking categories, cigarette smokers with chronic bronchitis had a higher incidence than those without it, and this relationship was maintained irrespective of age and amount smoked. It is concluded that persons who smoke run a higher risk of chronic bronchitis than non-smokers and those who develop bronchitis run a higher risk of developing lung cancer.     

Consistency in condom use in the context of HIV/AIDS in Zimbabwe

Against the backdrop of a high prevalence of the human immunodeficiency virus infection in Zimbabwe, this paper analyses data from the 1997 Zimbabwe Sexual Behaviour and Condom Use Survey to throw light on the degree to which sexually active adults consistently use condoms in high-risk sexual situations. The multivariate results indicate that at the time of the survey, consistent condom use in non-marital relationships is significantly higher for males than females, higher among those who had access to information about condoms from multiple sources than among those with limited access, and higher among those who have positive attitudes to condoms than among those with negative attitudes. Even though consistent condom use with non-marital partners is higher for those who know a source where condoms can be obtained, this effect is due to the fact that these respondents have more positive attitudes towards condoms. Likewise, the higher levels of consistent condom use exhibited by those who are aware of the efficacy of condoms are due to the fact that men have higher awareness of this, and men use condoms more consistently than women. In sum, the results suggest that the effects of the respondents' sex and their knowledge of the prophylactic importance of condoms and where condoms might be obtained are a function of other socioeconomic advantages they have. It is, therefore, concluded that programmes that use mass media information, education and communication campaigns to reduce shyness, embarrassment and stigma about condom use can help increase consistent use of condoms in non-marital relationships in Zimbabwe.     

Developmental changes in bone mineral structure demonstrated by extended X-ray absorption fine structure (EXAFS) spectroscopy

EXAFS spectra have been recorded above the calcium K edge from bones of mice aged 3 days, 1 week, 1 month, 2 months and 7 months. Spectra indicated that the calcium ion environment in bone mineral changes during development. Results were compared with those obtained from amorphous calcium phosphate and a poorly crystalline hydroxyapatite matured from this amorphous calcium phosphate in the presence of water. Spectra from the older mice closely resembled those of the matured product but those from the younger mice were more like those from the freshly prepared amorphous calcium phosphate.     

Folate Status Throughout Pregnancy and in Postpartum Period

The serial trends of the whole blood folate level in two groups of patients have been followed throughout pregnancy and up to six weeks postpartum. In those receiving iron alone the whole blood folate remained normal until the test at six weeks after delivery, at which time over half were in the deficient range. There appears to be a delay before this test reflects the current folate status when this changes rapidly. In those receiving iron plus 330 μg. of folic acid a day the results at this time were close to those at the beginning of pregnancy. Subnormal whole blood folate, red cell folate, and serum folate values occurred close to term in patients receiving iron alone, but were not found in those also receiving folic acid. Megaloblastic changes occurred at term in three patients receiving iron alone in whom the whole blood folate had repeatedly been low in early pregnancy.The observations are consistent with the previous suggestion that 300 μg. of folic acid daily is a suitable supplement to prevent deficiency in late pregnancy and the puerperium.     

Parathenar palmar pattern: a dermatoglyphic sign of possible clinical significance.

The frequency of a 'double proximal axial triradius' (DPAT), which results in a palmar parathenar pattern, has been reported to be increased in those with ventricular septal defect (BSD). We scored the presence of this pattern in 313 patients with congenital heart defects (including 86 with isolated VSD), 176 with cystic fibrosis (CF) or relatives of those with CF, and 333 with no known clinical disease who were unrelated to individuals with CF. The frequencies in these three groups were 1.6, 2.3, and 0.6%, respectively. None of those with isolated VSD defect had a DPAT. All five individuals in the heart defect group with a DPAT had pulmonic stenosis. Of the total of eleven individuals in our series with DPAT patterns, eight were affected only on the right hand. The frequency of DPAT in individuals with no known disease in this series was 4/406=1.0%, more than double the frequency in a control series, published previously by DAVID, 5/1,129=0.4%. If the 73 relatives of those with CF are excluded from our own 'control' group, the frequency of DPAT in this group is then 0.6%, closer to the results in DAVID's control series.     

Mechanism of selection of side-chain rotamers in α-helices

In this study, a possible mechanism of selection of side-chain rotamers based on the rotamer distributions in known coiled-coil proteins is suggested. According to this mechanism, interhelical hydrophobic, polar, and packing interactions bring alpha-helices closer to each other and this effect squeezes side chains out of the helix-helix interface. As a result, in dimeric coiled coils and long alpha-alpha-hairpins where alpha-helices are packed in a face-to-face manner, most side chains occupying the a-positions have t-rotamers and those in the d-positions g(-)-rotamers. In tetramers, where alpha-helices are packed side-by-side, most side chains in the a-positions adopt g(-)-rotamers and those in the d-positions t-rotamers.     

Use of a new methylene blue derivative for determination of lipid peroxides in foods

To determine lipid peroxides in chloroform-methanol extracts of foods, a simple and sensitive colorimetric method using a new leucomethylene blue derivative was adopted. The amounts obtained by this method coincided well with those by the iodometric method and paralleled those by the thiobarbituric acid method.     

Mouse models of neurological disorders: A view from the blood–brain barrier

The number of disease models that involve an aspect of blood–brain barrier (BBB) dysregulation have increased tremendously. The main factors contributing to this expansion have been an increased number of diseases in which the BBB is known to be involved, an increase in the known functions of the BBB, and an increase in the number of models and tools with which those diverse functions can be studied. In many cases, the BBB may be a target of disease; current thinking would include hypertensive encephalopathy and perhaps stroke in this category. Another category are those diseases in which special attributes of the BBB may predispose to disease; for example, the ability of a pathogen to cross the BBB often depends on the pathogen's ability to invoke transcytotic pathways in the brain endothelial or choroid plexus cell. Of special interest are those diseases in which the BBB may be the primary seat of disease or play a major role in the onset or progression of the disease. An increasing number of diseases are so categorized in which BBB dysfunction or dysregulation plays a major role; this review highlights such roles for the BBB including those proposed for Alzheimer's disease and obesity.     

The N-glycosylation pattern of Caenorhabditis elegans

Determining the exact nature of N-glycosylation in Caenorhabditis elegans, a nematode worm and genetic model organism, has proved to have been an unexpected challenge in recent years; a wide range of modifications of its N-linked oligosaccharides have been proposed on the basis of structural and genomic analysis. Particularly mass spectrometric studies by a number of groups, as well as the characterisation of recombinant enzymes, have highlighted those aspects of N-glycosylation that are conserved in animals, those which are seemingly unique to this species and those which are shared with parasitic nematodes. These data, of importance for therapeutic developments, are reviewed.     

EVOLUTION OF BREEDING DISTRIBUTIONS IN THE OLD WORLD LEAF WARBLERS (GENUS PHYLLOSCOPUS)

Among Palearctic warblers of the genus Phylloscopus those species that breed farther north occupy larger geographical ranges than those which breed farther south (Rapoport's rule). We suggest that much of this pattern is a consequence of the differential ability of species to occupy areas rendered inhospitable during the Pleistocene. In support of this suggestion, the midpoint of breeding range in a north-south direction has been an exceptionally labile trait through evolutionary time. Comparisons of ecological attributes of those species breeding in the Himalayas with close relatives in Siberia implies a role for habitat tracking in determining which species have been able to colonize northern areas; hypotheses based on climate and climatic variability have less support. In addition there is a likely role for geographic barriers and/or biotic interactions in preventing some taxa from spreading from small southern ranges.     

Mechanisms of salinity tolerance in plants

The mechanisms of salt stress response and tolerance have eluded definition despite reasonable success in defining their physiological manifestations. In this review, we consider the integrated salt metabolism of plants, essentially as a problem in meganutrient physiology. Two critical aspects of cellular and organismal metabolism are given particular attention—those involved in the control and integration of Na⁺ acquisition and allocation in plants and those involved in readjustment of other aspects of metabolism, especially those involving carbon as a resource.