Biospecific Interaction in Electrophoresis

Aspects of practical assessment such as question design and management of the assessment are discussed. Reference is made to some of the problems and to the possibilities for innovation which are possible as a result of implementing practical assessment of the kind required by the GCSE examining groups.     

The influence of artery wall curvature on the anatomical assessment of stenosis severity derived from fractional flow reserve: a computational fluid dynamics study

This study aims to investigate the influence of artery wall curvature on the anatomical assessment of stenosis severity and to identify a region of misinterpretation in the assessment of per cent area stenosis (AS) for functionally significant stenosis using fractional flow reserve (FFR) as standard. Five artery models of different per cent AS severity (70, 75, 80, 85 and 90%) were considered. For each per cent AS severity, the angle of curvature of the arterial wall varied from straight to an increasingly curved model (0°, 30°, 60°, 90° and 120°). Computational fluid dynamics was performed under transient physiologic hyperemic flow conditions to investigate the influence of artery wall curvature on the pressure drop and the FFR. The findings in this study may be useful in in vitro anatomical assessment of functionally significant stenosis. The FFR decreased with increasing stenosis severity for a given curvature of the artery wall. Moreover, a significant decrease in FFR was found between straight and curved models discussed for a given severity condition. These findings indicate that the curvature effect was included in the FFR assessment in contrast to minimum lumen area (MLA) or per cent AS assessment. The MLA or per cent AS assessment may lead to underestimation of stenosis severity. From this numerical study, an uncertainty region could be evaluated using the clinical FFR cutoff value of 0.8. This value was observed at 81.98 and 79.10% AS for arteries with curvature angles of 0° and 120° respectively. In conclusion, the curvature of the artery should not be neglected in in vitro anatomical assessment.     

Formative fieldwork for the younger pupil

In the early days of the FSC, younger pupils comprised only about 4% of visitors to the Centres; this proportion fell to around 1% in the mid 1970s but has risen dramatically (to 16% in 1986) during the present decade. During 1986, the introduction of GCSE has brought a further factor into play and the F'SC's junior category now embraces the range from 6-year-olds to GCSE pupils. At all levels, courses are carefully designed in consultation with school staff to enable pupils to gain the maximum benefit from their visit. While there is always a carefully-structured basis to a course, the approach to a topic is as heuristic as possible and child-centred learning is considered critically important. In GCSE courses, care is taken to link content to both the National Criteria of the Secondary Examination Council and the more detailed requirements of the particular syllabus being followed.     

A TEN-YEAR STUDY OF ANENCEPHALY

The incidence of anencephaly at the Los Angeles County General Hospital during the period of July, 1948 through June, 1958 was 0.049 per cent. Worldwide the range of reported incidence is 0.012 per cent to 0.671 per cent.In this study 65 per cent of the total number of anencephalics delivered were females, a predominance agreeing with reports by other investigators.Polyhydramnios appeared in 38 per cent of the anencephalic pregnancies of this study, while 15 per cent of the deliveries were complicated by placenta praevia.A significant number (48 per cent) of the multiparae gave a history of previous stillbirths or abortions.The present study does not support observations by other investigators which indicated an increase in anencephalic births during the winter months.Evidence from stillbirth statistics would seem to indicate that anencephaly is primarily a genetically induced phenomenon. Further evaluation and analysis of the predominance of females in anencephalic stillbirths and abortions is suggested, in order to study whether the observed secondary or birth sex ratio (in which males predominate) is, in fact, due to genetic effect.     

A RAPID METHOD FOR SELECTIVE SILVER STAINING OF NERVE FIBRES AND NERVE ENDINGS IN MOUNTED PARAFFIN SECTIONS

Abstract The staining described in this paper fundamentally is performed by two manipulations, namely (1) the treatment of deparaffinized sections for about fifteen minutes in a solution containing 15 per cent silver nitrate, 10 per cent potassium nitrate and 0.05 per cent glycine, and (2) the reduction for one minute in a solution of 1 per cent pyrogallol, 55 per cent ethyl alcohol and a trace (0.002 per cent) of nitric acid. After toning, dehydrating and mounting in the usual manner the sections generally are ready for examinations within less than an hour. The method is available for specimens fixed in the ordinary fixatives but those containing oxidizing metal compounds. The procedure is discussed from a theoretical point of view and some results are shown in photomicrographs.     

HYPOTHYROIDISM IN MEN IN INDUSTRY—A Preliminary Report on Chemical Evidence

Of 2,807 specimens from blood donors and men in industry, 340 or 12 per cent had serum protein-bound iodine values of 4.0 micrograms or less per 100 cc.In a selected group of 610 “white collar” workers, 52 or 8.5 per cent had similar low values.Careful reexamination of a sample of the latter group indicated that at least 75 per cent of them had hypothyroidism needing treatment.Further analysis of the factors producing hypothyroidism and the validation of the incidence found is warranted. If the incidence observed in this study is confirmed, these findings indicate that 6 per cent to 9 per cent, or more than a million middle aged American men have hypothyroidism.     

STAPHYLOCOCCIC INFECTIONS IN CHILDREN

Over 50 per cent of all staphylococcic infections are hospital-acquired. In 92 per cent of hospital-acquired infection, the organism is resistant to penicillin, and in 74 per cent to tetracycline.Chloramphenicol, bacitracin, novobiocin and erythromycin are the drugs of choice for therapy. There was good correlation between clinical response and antibiotic therapy selected on the basis of results of organism sensitivity tests done by the agar diffusion technique.Cross-resistance among the tetracyclines averaged 94 per cent. Erythromycin and magnamycin showed similar pattern.Mortality in infants less than two months old was 7.8 per cent as compared with 1.1 per cent in older children. Death was related either to pneumonia or to septicemia in the ten fatalities recorded in this series.     

Teacher assessment of University of London A-level biology practical notebooks—a report on the first operational examination

From June 1980 onwards most home candidates taking the University of London Advanced level Biology Examination have been required to submit their practical and fieldwork notebooks for assessment by their teachers. The teacher-assessed component of the examination contributes 10 per cent to their final subject mark. This paper describes the research undertaken during the first operational examination. The method of assessment is reviewed and the moderation techniques are analysed and discussed in the light of known problems. The assessment and its moderation both appear to be functioning satisfactorily.     

OXYGEN TENSION AND THE RATES OF MITOSIS AND INTERPHASE IN ROOTS

The object of this work was to determine the influence of a wide range of oxygen tensions upon the relative rates of respiration, mitosis, and interphase in pea root tips, compared with the normal rates of these processes in air. From the rates of disappearance of mitotic figures in excised tips kept in various oxygen tensions, the relative rates of mitosis were found to decrease gradually from 122 per cent in 100 per cent oxygen to 24 per cent in 0.0007 per cent oxygen. From the mitotic indices of intact seedlings, the relative rates of interphase were found to decrease sharply from 82 per cent in 10 per cent oxygen to 6 per cent in 5 per cent oxygen. The data on relative rates of respiration, mitosis, and interphase in root tips were compared, and it was shown that the three processes are perfectly distinct in their quantitative relationships to low oxygen tensions.     

Effect of dietary fat on lymphocyte proliferation and metabolism

The effect of diets enriched with fat containing different fatty acids on glucose and glutamine metabolism of mesenteric lymph nodes lymphocytes, spleen, and thymus and lymphocyte proliferation was examined. The following fat-rich diets were tested: (1) standard chow (CC); (2) medium chain saturated fatty acids (MS)—coconut fat oil; (3) long chain saturated fatty acids (LS)—cocoa butter; (4) monounsaturated fatty acids (MU)—canola oil (n-9); (5) polyunsaturated fatty acids (PU)—soybean oil (n-6). Of the fat-rich diets tested, MS was the one to present the least pronounced effect. Lymphocyte proliferation was reduced by LS (64 per cent), MU (55 per cent), and PU (60 per cent). Hexokinase activity was enhanced in lymph node lymphocytes by PU (67 per cent), in the spleen by MS (42 per cent), and in the thymus by PU (30 per cent). This enzyme activity was reduced in the spleen (33 per cent) by LS and MU (35 per cent). In the thymus, this enzyme activity was reduced by LS (26 per cent) and MU (13 per cent). Maximal phosphate-dependent glutaminase activity was raised in lymphocytes by MS (70 per cent) and MU (20 per cent). This enzyme activity, however, was decreased in lymphocytes by PU (26 per cent), in the spleen by LS (15 per cent), and in the thymus by MU (44 per cent). Citrate synthase activity was increased in lymphocytes by MU (35 per cent), in the spleen by LS (56 per cent) and MU (68 per cent), and in the thymus by LS (42 per cent). This enzyme activity was decreased in lymphocytes by PU (24 per cent) only. [U-¹⁴C]-Glucose decarboxylation was raised by all fat-rich diets; MS (88 per cent), LS (39 per cent), MU (33 per cent), and PU (50 per cent), whereas [U-¹⁴C]-glutamine decarboxylation was increased by LS (53 per cent) and MU (55 per cent) and decreased by MS (17 per cent). The results presented indicate that the reduction in lymphocyte proliferation due to LS, LU and PU could well be a consequence of changes in glucose and glutamine metabolism. Copyright © 1998 John Wiley & Sons, Ltd.     

Mineralization of nitrogen in two soil-organic-matter fractions extracted with formic acid

Summary Extraction of a calcareous meadow soil with boiling formic acid containing 10 per cent acetylacetone yielded a fraction of soil organic matter representing about 40 per cent of the total. This fraction contained only 2.2 per cent N. Less than 18 per cent of this was mineralized during incubation for 8 weeks at 28°C. Further extraction of the soil with a formic acid and hydrofluoric acid mixture yielded a second fraction. This represented about 37 per cent of the total organic matter and contained 6.0 per cent N of which up to 41 per cent was mineralized during incubation. Preincubation and leaching had a stabilizing effect on subsequent mineralization of native N of a standard sandy loam soil.     

Teacher assessment of A-level biology practical notebooks—the development of a system of moderation

From June 1980 onwards most home candidates taking University of London Advanced level Biology are required to submit their practical and fleldwork notebooks to their teachers for an assessment which contributes up to 10 per cent of their final subject mark. This paper describes a trial run assessment of the practical books of 700 candidates, conducted in June 1979, and the statistical moderation procedure produced.     

I’m neither racist nor xenophobic,but: dissecting European attitudes towards a ban on Muslims’ immigration

During his presidential campaign, the new elected President of U.S., Donald Trump, called for a complete ban on Muslims from entering the United States. Although numerous European observers have been shocked by this proposal, using the most recent European Social Survey immigration module, this paper found that a sizeable proportion of Europeans support a similar ban in their own countries, e.g. Czech Republic (54 per cent), Hungary (51 per cent), Estonia (42 per cent), Poland (33 per cent), and Portugal (33 per cent). The paper also provides evidence that racism and immigration phobia play a key role in shaping Europeans’ support of a ban on Muslims’ immigration.     

TIME RELATIONS OF GROWTH : III. GROWTH CONSTANTS DURING THE SELF-ACCELERATING PHASE OF GROWTH.

Growth curves consist, in all cases, of two major segments. The first major segment is, in the case of higher animals and plants, made up in turn of several (probably five) shorter segments during each of which growth takes place at a constant percentage rate. The transitions between the successive stages are abrupt, the abruptness being of the order of metamorphosis in cold blooded animals. It has been made clear in the first paper of this series that the time rate of growth following the major inflection declines at a constant percentage rate. The junction between the two major segments occurs at puberty in animals and flowering in plants. The two major segments are not symmetrical about the major inflection. The slope of the segment following the inflection is always less than the slope of the segment preceding the inflection. The major inflection does not occur in the center of the growth curve. The instantaneous rate of growth at the beginning of growth is of the order of 100–200 per cent per day (i.e. the body weight is doubled in from 7 to 17 hours). It may be mentioned that 2 months after conception the rate of growth in man is only 8 per cent per day. This is contrary to all the published statements. Thus, Minot concluded that growth begins at 1000 per cent per day; Jackson concluded that in man, growth during the 1st month takes place at 57.5 million per cent per month; during the 2nd month 990 per cent per month; during the 3rd month 390 per cent per month (8 per cent per day is only 240 per cent per month). The reason for the discrepancy between the values derived, by the method adopted by the writer, and the values given in the literature is explained by Fig. 1.     

Do Spanish Hospital Professionals Educate Their Patients About Advance Directives?

It is unknown whether hospital-based medical professionals in Spain educate patients about advance directives (ADs). The objective of this research was to determine the frequency of hospital-based physicians’ and nurses’ engagement in AD discussions in the hospital and which patient populations merit such efforts. A short question-and-answer-based survey of physicians and nurses taking care of inpatients was conducted at a university hospital in Madrid, Spain. In total, 283 surveys were collected from medical professionals, of whom 71 per cent were female, with an average age of thirty-four years. Eighty-four per cent had never educated patients about ADs because of lack of perceived responsibility, time, or general knowledge of ADs. Patient populations that warranted AD discussions included those with terminal illnesses (77 per cent), chronic diseases (61 per cent), and elderly patients (43 per cent). Regarding degree of AD understanding in medical professionals: 57 per cent of medical professionals claimed sufficient general knowledge of ADs, 19 per cent understood particulars regarding AD document creation, and 16 per cent were aware of AD regulatory policies. Engagement in AD discussions was considered important by 83 per cent of medical professionals, with 79 per cent interested in participating in such discussions themselves. The majority of hospital physicians and nurses do not educate their patients about ADs, despite acknowledging their importance. Patient populations of highest priority included those with terminal diseases or chronic illness or who are of advanced age.     

Hospital Bills—What Portion Is Paid by Insurance?—Report of Bureau of Research and Planning

A two-year survey result—ending some 18 months ago and just released—reveals that 68 per cent of all short-stay hospital discharges had hospitalization coverage. Insurance paid three-fourths or more of the bill for over 75 per cent of those covered.One-half of the discharges in the 65+ age group were covered. Almost 60 per cent of this group had three-fourths or more of the hospital bill paid by voluntary health insurance.The 65+ group with family income under $4,000 had better protection than age groups under age 45.The highest per cent of coverage was in the 45 to 64 age group where over 75 per cent of the discharges had coverage, with insurance paying more than three-fourths of the bill. This is the group which is likely to retain coverage upon retirement.     

Stability of the brain fatty acid pattern in adult rats during extreme starvation

Abstract— Adult rats were denied food for 7 days. As compared with a control group, this severe starvation reduced the mean total body weight by 44 per cent, the weight of the diaphragm by 33 per cent and liver by 67 per cent, the total lipid content of the diaphragm by 57 per cent and liver by 69 per cent, and the total lipid phosphorus content of the diaphragm by 19 per cent and liver by 68 per cent. The decrease in lipid phosphorus contents indicates that the diaphragm and liver catabolized membrane phospholipids as well as triglycerides. In contrast, the fresh weight of the brain and the total lipid content of the brain were not significantly altered by starvation. The fatty acid patterns of the total lipid of the diaphragm and liver (determined by GLC) were grossly altered by starvation. In the brain, however, 17 of the 21 fatty acids measured did not change significantly (P > 0.05) and the remaining four changed, with borderline statistical significance, by only 2 to 13 per cent. There was no significant effect of starvation of the pattern of the brain polyunsaturated fatty acids when measured by alkali isomerization. In contrast to the liver and diaphragm, the brain is apparently unable to utilize its lipids appreciably as an energy source. Presumably the lipids of the brain are preserved to permit this organ to function properly, even in the last stages of starvation.     

粉剂防治粘虫Pseudaletia separata (Walker)研究

粘虫Pseudaletia separata(Walker)是粮食作物的毁灭性害虫,也是全国农业发展纲要(修正草案)所规定要消灭的八大害虫之一。粘虫在大发生时为害面积很广,虫体发育迅速,食量很大,过去多采用人工器械捕打办法,但不能澈底解决问题,尤其在作物密植的情况下,捕打也发生了困难,常因捕打时将作物践踏而引起损失,因此要求在发生时应用化学防治方法,以达到迅速消灭为害之目的。     

The genetics of urinary tract malformations

In this discussion I have excluded consideration of the genetics of purely renal malformations, such as polycystic kidneys, and of functional disorders of the kidney. Systematic family studies are available for renal agenesis, duplication of the ureters, vesico-ureteric reflux (each probably due to maldevelopment of the ureteric bud), bladder exstrophy and hypospadias as isolated malformations. Renal agenesis has a birth frequency of about 1.2 in 10 000 and the proportion affected of sibs is about 3 per cent. Duplication of the ureter has a birth frequency of about 1 per cent and the proportion affected of sibs and parents of probands is about 12 per cent. Vesico-ureteral reflux also has a prevalence in early childhood of about 1 per cent and the proportion of sibs affected is about 10 per cent. Bladder exstrophy has a birth frequency of about 1 in 20 000 and perhaps about 1 per cent of sibs are affected. Hypospadias has a birth frequency in boys of about 1 in 300 and the proportion affected of brothers is about 10 per cent. Further family studies are needed of these malformations when they occur in isolation. Either the multifactorial threshold model or dominant inheritance with reduced penetrance and varied expressivity would fit the data available.     

Influence of seed moisture content and post-irradiation hydration temperature on the kinetics of reactivity towards oxygen or decay of oxygen-sensitive sites.

The rate of development of post-irradiation oxygen-dependent damage when oxygen is available, and its rate of elimination when seeds are first post-hydrated in oxygen-free water prior to their transfer to oxygenated water, was studied in barley seeds of approximately 3 per cent, approximately 8 per cent and approximately 9 per cent moisture contents at 3 degrees C, 25 degrees C and 37 degrees C. The magnitude of oxic damage at a given dose (35 krad) decreases as the initial seed moisture content increases from approximately 3 per cent to approximately 9 per cent. Significant (P = 0.01) oxic damage is observed in seeds of all the three moisture contents at 3 degrees C and 25 degrees C; however, at 37 degrees C significant (P = 0.01) oxic damage is observed only in seeds of approximately 3 per cent and approximately 8 per cent moisture contents. The magnitude of oxic damage in seeds of a given moisture content remains unaltered following oxygenated post-hydration of seeds at 3 degrees C and 25 degrees C, but it registers a significant (P = 0.01) decrease if post-hydration in oxygenated water is carried out at 37 degrees C. The radiation-induced oxygen-sensitive (An) sites react with oxygen approximately 6 to 8 times faster as compared to their rate of decay in the absence of oxygen at both 3 degrees C and 25 degrees C; however, at 37 degrees C they react only approximately 3 to 4 times faster, in seeds of all the three moisture contents. Moreover, the initiation of the decay of An sites becomes evident much earlier in very dry (approximately 3 per cent moist) seeds than in relatively moist (approximately 8 per cent and approximately 9 per cent) seeds. It is also observed that this fraction of An sites which is capable of a very rapid rate of decay in the absence of oxygen is capable also of an even more rapid rate of reactivity towards oxygen.