Meteorological factors and the time of onset of chest pain in acute myocardial infarction

Analysis of the time of onset of chest pain in 2254 patients with a myocardial infarction admitted to a coronary care unit in Leicester during a 10-year period shows an association with temperature and humidity. During both the most cold and humid times of the year, the relationship is a strong one. A generalized linear model with a log link was used to fit the data and the backward elimination selection procedure suggested a humid, cold day might help to trigger the occurrence of myocardial infarction. In addition, cold weather was found to have a stronger effect on the male population while those men aged between 50 and 70 years were more sensitive to the effect of high humidity.     

Keratinolytic fungi in sewage sludge

Sewage sludge from the Upper Silesia Region of Poland were surveyed for keratinolytic fungi. Out of 100 Petri dishes examined, 89 were positive for these micro-organisms. Altogether, 185 fungal appearances belonging to 10 species were observed. Trichophyton terrestre with its teleomorph Arthroderma quadrifidum, T. ajelloi with A. uncinatum, Microsporum gypseum with Arthroderma sp., and Chrysosporium keratinophilum with Aphanoascus keratinophilus prevailed in the sludges. The sewage treatment technologies together with the sludge structure, humidity and pH were found to be critical factors determining the occurrence of keratinolytic fungi in the sludge environment. The qualitative and quantitative composition of keratinolytic fungi could be a useful tool in evaluation of sludge treatment processes.     

Resolution of natural hatching factors for golden potato cyst nematode, Globodera rostochiensis

The hatching responses of Globodera rostochiensis (golden potato cyst nematode) to purified and partially-purified preparations of natural (including the potato glycoalkaloids solanine and α-chaconine) and artificial hatching factors (HFs) were bimodal. At least 10 HFs, mostly anionic, were resolved from potato root leachate by a combination of gel permeation and ion-exchange chromatography. Whereas potato roots were the principal source of HFs, haulm leachate also contained such chemicals. Root leachate from aseptically-grown potato plants lacked several HFs which were present in conventionally-produced leachate.     

Flower heliotropism in an alpine population of Ranunculus acris (Ranunculaceae): effects on flower temperature,insect visitation,and seed production

Some plants in arctic and alpine habitats have heliotropic flowers that track the sun. This results in a heating of the flower's interior, which may improve the possibilities for insect pollination and seed production. Here, I examine whether flower heliotropism in an alpine population of the self-incompatible Ranunculus acris L. (Ranunculaceae) enhances pollinator visitation and seed production. Flowers of Ranunculus acris tracked the sun during the day. Tracking accuracy was greatest during the middle of the day. The temperature elevation in flowers was negatively correlated with the flower's angle of deviation from the sun. Despite the increased temperature, insects did not discriminate among flowers on the basis of their angle of deviation from the sun, or tend to stay longer in the flowers aligned closest towards the sun. A tethering experiment was conducted on three groups of plants flowering at different times in the 1993 season and on one group the following season. Manipulation plants were constrained not to track the sun, whereas control plants tracked the sun naturally. Solar tracking had no effect on seed:ovule ratio, seed mass, or abortion rate in any of the groups. There is probably a very narrow range of weather conditions (cold, sunny, and calm) where flower heliotropism may enhance visitation rate to flowers and their seed production.     

Habitat utilization patterns of sympatric populations of Pseudomys gracilicaudatus and Rattus lutreolus in coastal heathland: A multivariate analysis

Abstract Habitat usage characteristics of two species of native murid rodents, Pseudomys gracilicaudatus and Rattus lutreolus were investigated on an area of coastal heathland at Myall Lakes National Park. A grid of 151 trap stations comprising 17 traplines was positioned across a mosaic of habitats. At each trap station 19 structural vegetation and physical variables known to affect the microdistribution of small mammals were measured. Multivariate statistical procedures identified those microhabitat variables that contribute to individual species' habitat use and habitat partitioning, and reduce potential competition for space. Cluster analysis classified trap stations into one of six habitat types that were mapped on the study area, identifying a heterogeneous assemblage of interlocking habitats. The pattern is a consequence of topographic variation on the site and, to a lesser extent, its fire history. Trapping results show P. gracilicaudatus and R. lutreolus exhibit similar macrohabitat selection, preferring topographically low habitats, with both species predominantly occupying short dense heath with dense sedge cover. The high overlap in macrohabitat use is greatly reduced when considered trap station by trap station, so that discriminant function and multiple regression analyses demonstrate marked microhabitat selection. Elevation was a highly significant variable, accounting for 41% and 27% of the variance in the habitat used by P. gracilicaudatus and R. lutreolus, respectively. This variable represents a soil moisture gradient that determines changes in the floristic and structural components of the biotic environment. Two other structural vegetation variables and vegetation height contributed 30% of the variance in P. gracilicaudatus distribution. Sedge cover was found to be significant and explained 13% of the variance in R. lutreolus distribution. Within-habitat separation was explained best with a linear combination of variables in a discriminant function, rather than by any single variable. Differential microhabitat selection, interference competition and diet separation appear to be the major factors facilitating coexistence of these two species.     

Bioremediation of a petroleum‐contaminated cryic soil: Effects of phosphorus,nitrogen, and temperature

Bioremediation has been shown to be an effective means of treating petroleum‐contaminated soils in cold areas, although the conditions required to maximize bioremediation in cold region (cryic) soils are not well documented. A laboratory study was conducted to investigate the effects of nitrogen and phosphorus levels and temperature on petroleum bioremediation. A cryic entisol contaminated with diesel fuel was treated with nitrogen (0, 400, 800, or 1200 mg/kg of soil) and phosphorus (0, 60, 120, or 180 mg/kg of soil) and incubated at two temperatures (10 and 20°C). At 10°C, bioremediation rates were not affected by fertility treatments. At 20°C, reaction rates were increased by the addition of P, but unaffected by N. Regardless of fertility regime, the rate of diesel loss was much greater in soil incubated at 20°C than in soil incubated at 10°C.     

牛肝提取物提高仔鸡免疫力的研究

将牛肝提取物注射到第13日龄和第15日龄鸡胚中能显著提高孵出后仔鸡的抗SRBC血清抗体的效价,促进脾和法氏囊淋巴细胞增殖、分化。同时,牛肝提取物与雏鸡法氏囊粗提取液,抗鸡法氏囊病毒抗体均有增强仔鸡抵抗传染性法氏囊病的能力。实验结果表明牛肝提取物中可能含有类似法氏囊素的物质。     

Self-Reported Substantial 1-Year Weight Change Among Men and Women in the United States

Population-based data have not been readily available on relatively short-term changes in weight. Therefore, we sought to determine the nature of self-reported substantial (> 10%) weight change over one year in a representative sample of the US population which participated in the 1989 National Health Interview Survey (NHIS). Across all ages, a larger proportion of women than men reported both weight loss as well as weight gain of any amount (18.9% vs. 16.1% for weight loss and 20.0% vs. 16.1% for weight gain). In sex-specific logistic regression analyses, significant risk factors common to both sexes for substantial weight loss included divorced/separated marital status, smoking, increased number of blood pressure checks, increased BMI (body mass index) and increased number of bed days. Black race reduced the risk of weight loss for both men and women. Sex-specific risk factors for weight loss in men only were widowhood or never married marital status, while increasing age was a protective factor in women only. Concerning weight gain > 10% over the past year, increased number of blood pressure checks and having one or more diabetic parents were significant risk factors among both men and women; while never being married, increased age, BMI, and education exerted a protective effect in both sexes. For women only, risk factors for weight gain included black race, increased number of contacts with a health professional, and being unemployed. Intention to lose weight was associated with both weight gain and weight loss in both sexes, although it did not serve as a confounder in any of these relationships. A greater likelihood of substantial weight loss among women relative to men was diminished for persons with higher BMI, higher number of blood pressure checks, being widowed, divorced or separated, and intention to lose weight. A greater likelihood of substantial weight gain among women relative to men was diminished for persons with low BMI. The results of this cross-sectional study of weight change, involving a one-year follow-up period, generally correspond with the results obtained by longitudinal studies involving a longer follow-up.     

不同生境区稻田节肢动物群落相似性分析

根据不同生境区稻田节肢动物群落系统调查结果,应用组平均聚类分析法及主成分分析法,讨论节肢动物群落的相似（相异）性问题。结果表明：生境条件及管理措施的差异对群落的结构影响较为明显,不同生境区的稻田节肢动物群落,都能在一定距离取值时聚合成一类,而水稻品种对此影响较小。主成分分析结果由二维图表达已基本满足要求。结果说明大八镇生境区稻田节肢动物群落与岗列镇生境区稻田节肢动物群落差异较大,分别列于两个极端。海陵镇生境区稻田介于两者之间,而与岗列镇生境区稻田节肢动物群落重叠。与聚类分析结果有所差异。这可能与主成分分析法损失部分信息有关。