Evaluation of the level of difficulty of patient cases for veterinary problem-solving examination: a preliminary comparison of three taxonomies of learning

An important issue that has received insufficient attention in the use of problem-based learning in the medical curriculum is the mode of assessing the level of difficulty of patient cases. In the present study, the level of difficulty of case-based questions in a veterinary degree final examination in reproduction was evaluated. First, cognitive taxonomies were evaluated to clarify whether qualitative methods such as Bloom's taxonomy, the Structure of the Observed Learning Outcome (SOLO) taxonomy, and the Amsterdam Clinical Challenge Scale (ACCS) differed from each other as evaluation tools for problem-based cases. Using these taxonomies, 30 case-based questions from the final examination in reproduction in the Helsinki veterinary program were initially evaluated to determine which one was best suited to the evaluation of the difficulty of cases. In follow-up, the same cases were also evaluated by an experienced veterinary instructor in reproduction, with the aim of gaining insight into using these approaches to evaluating difficulty. It would appear, from this preliminary assessment, that the SOLO taxonomy may be the most suitable for evaluating the difficulty of patient cases, since the instructor's quality rating resembled more closely the SOLO than the Bloom taxonomy or the ACCS. It is to be emphasized that the purpose of this study was to provide a preliminary evaluation of possible approaches that might be used to assess patient-case difficulty. Resolving all issues will require a greater number of evaluations of all components.     

神农架林区森林资源可持续发展途径探讨

笔者以神农架林区为例,用全面规划、总体布局的观点分析林区资源特点与利用现状问题,并以天然林保护工程为重点,实现森林保护多种效益的永续利用为目标,以探讨我省国有林区森林资源可持续发展的有效途径,提出国有林区森林资源可持续发展的关键是对现有林科学合理地经营和管护,并指出在禁伐区、一般公益林区和商品林区应采取的不同策略。     

Diameter growth of Scots pine (Pinus sylvestris) trees grown at elevated temperature and carbon dioxide concentration under boreal conditions

We investigated the impacts of elevated temperature and carbon dioxide concentration ([CO2]) on diameter growth of Scots pine (Pinus sylvestris L.), aged about 20 years, grown with a low nitrogen supply in closed chambers at (i) ambient temperature and [CO2] (AT+AC), (ii) ambient temperature and elevated [CO2] (AT+EC), (iii) elevated temperature and ambient [CO2] (ET+AC), and (iv). elevated temperature and [CO2] (ET+EC). Each treatment was replicated four times. Diameter growth was monitored with a band dendrograph at 15-min intervals throughout the growing seasons of 1997, 1998 and 1999. Over the monitoring period, diameter growth began 2-3 weeks earlier in trees in the ET+EC and ET+AC chambers than in trees in the AT+AC and AT+EC chambers. However, the cessation of growth occurred about a week later in trees in the ET+EC, ET+AC and AT+EC chambers compared with the AT+AC chambers. The duration of the growing season was 115 and 108 days in the ET+EC and ET+AC chambers, respectively, and 95 and 84 days in the AT+EC and AT+AC chambers, respectively. The ET+AC and ET+EC treatments enhanced diameter growth most early in the growing season, whereas in trees in the AT+AC and AT+EC treatments diameter growth rate was highest in the middle of the growing season. Diameter growth rate leveled off more slowly in trees in the ET+EC and AT+EC treatments than in the other treatments. The growth response to elevated T, elevated [CO2] or both decreased with time and it was less than the maximum observed in other studies for small seedlings and under optimal growth conditions. Nevertheless, cumulative diameter growth for the 3-year period was 67% greater in trees in the ET+EC treatment, and 57 and 26% greater in trees in the AT+EC and ET+AC treatments, respectively, compared with trees in the AT+AC treatment. Over the 3 years, [CO2] had a statistically significant (P < 0.10) effect on both absolute and relative diameter growth, but the interaction between [CO2] and temperature was not significant.     

Wood properties of Scots pines (Pinus sylvestris) grown at elevated temperature and carbon dioxide concentration

Impacts of elevated temperature and carbon dioxide concentration ([CO2]) on wood properties of 15-year-old Scots pines (Pinus sylvestris L.) grown under conditions of low nitrogen supply were investigated in open-top chambers. The treatments consisted of (i) ambient temperature and ambient [CO2] (AT+AC), (ii) ambient temperature and elevated [CO2] (AT+EC), (iii) elevated temperature and ambient [CO2] (ET+AC) and (iv) elevated temperature and elevated [CO2] (ET+EC). Wood properties analyzed for the years 1992-1994 included ring width, early- and latewood width and their proportions, intra-ring wood density (minimum, maximum and mean, as well as early- and latewood densities), mean fiber length and chemical composition of the wood (cellulose, hemicellulose, lignin and acetone extractive concentration). Absolute radial growth over the 3-year period was 54% greater in AT+EC trees and 30 and 25% greater in ET+AC and ET+EC trees, respectively, than in AT+AC trees. Neither elevated temperature nor elevated [CO2] had a statistically significant effect on ring width, early- and latewood widths or their proportions. Both latewood density and maximum intra-ring density were increased by elevated [CO2], whereas fiber length was increased by elevated temperature. Hemicellulose concentration decreased and lignin concentration increased significantly in response to elevated temperature. There were no statistically significant interaction effects of elevated temperature and elevated [CO2] on the wood properties, except on earlywood density.     

Muscle fibre type distribution of the thoracolumbar and hindlimb regions of horses: relating fibre type and functional role

Background

Although the majority of equine muscles have a mixed fibre type distribution indicative of diverse functional roles, the predominance of a fibre type can indicate the primary function of a muscle. The deep epaxial musculature has an important role in core spinal stability in humans, reflected as a predominantly muscle fibre type (MFT) I or postural fibre type. The fibre type of the deep epaxial musculature has not been determined in horses. The objective of the study was to determine the MFT distribution in selected muscles of thoracolumbar and hindlimb region of horses. This included deep epaxial and hypaxial muscles that were hypothesised to have a postural stabilising role. A second objective was to examine differences in MFT distribution between horses bred for endurance (Arabian) and sprinting (Quarter horse). Muscle biopsy samples were obtained from selected thoracolumbar and hind limb muscles of 5 Quarter horses, 4 Arabians, and 2 Thoroughbreds. The myosin heavy chain distribution was determined by gel electrophoresis. Mann–Whitney rank test was used to compare the proportional MFT and differences between breeds.

Results

Mm. sacrocaudalis dorsalis medialis and diaphragm had the highest proportion of MFT-I. The remaining deep epaxial muscles and the hypaxial muscle m. psoas minor had approximately equal MFT I and II proportions. Mm. psoas major, iliocostalis, longissimus dorsi and the hind limb muscles contained mostly MFT-IIX. The fibre type distribution was similar between Arabians and Quarter horses, although Quarter horses had more MFT-IIX fibres in psoas major (P = 0.02) while Arabians had more MFT-I fibres in m. longissimus dorsi (P = 0.03).

Conclusions

The fibre type distribution of the deep epaxial muscles, mm psoas minor and diaphragm varied from approximately equal MFT-I and II proportions to predominantly MFT-I suggesting a postural stabilising role possibly important in core spinal stability. In contrast the fibre type proportions of mm psoas major, iliocostalis, longissimus dorsi and the hind limb muscles were mainly MFT-II suggesting a locomotory role. Knowledge of fibre type distribution in such a clinically important area can direct diagnosis, prevention and treatment of muscular or neuromotor dysfunction.     

无机及有机栽培对黄瓜生育的影响

本文探讨了当前食品生产存在的主要问题以及可持续农业和有机食品的重要性,该实验的目的是通过有机基质（城市有机垃圾堆肥）和无机基质（草炭、火山岩,营养液施肥）对黄瓜生长影响的比较,了解不同栽培基质的特性,掌握有机蔬菜生产技术体系.实验表明两种处理,黄瓜叶面积、地上和根系的鲜重、干重有很大差异,而叶片数差异不大,植株地上部生长与根系发育呈正相关,由于有机基质没有补充任何肥料,植株生长不良.为了生产无公害的安全食品,不同堆肥种类对蔬菜产量及品质的影响、有机栽培的施肥与管理还需进一步研究.     

大兴安岭火烧迹地主要目的树种的天然更新

对不同火烧方式、火烧强度、林分组成、坡向、坡位、郁闭度、土壤厚度、下木盖度、地被物盖度、林龄等条件下的样地的天然更新情况进行了调查。结果表明:地表火火烧迹地的天然更新效果好于树冠火火烧迹地;中度火烧迹地好于重度火烧迹地;发生火烧的林分比未发生火烧的林分天然更新效果好。     

潘敏求教授从“瘀、毒、虚”论治乳腺癌经验

潘敏求教授认为乳腺与肝、脾、肾及冲任二脉关系密切,“瘀”、“毒”、“虚”是乳腺癌的基本病机,“疏肝健脾、补肾益精、化瘀解毒”是治疗乳腺癌的主要治则,潘教授临床用药常扶正祛邪并用,中西结合综合治疗,在疏肝健脾的基础上,十分重视脾胃与肝肾之气,以自拟乳复方为基本方,随症加减,临床应用疗效满意。     

Clinical characteristics and persistence of bovine mastitis caused by different species of coagulase-negative staphylococci identified with API or AFLP

The coagulase-negative staphylococcal species causing mastitis in lactating cattle were identified and possible differences in the clinical characteristics or persistence of mastitis caused by different CNS were evaluated. The effect of antimicrobial treatment was also assessed. In addition, AFLP-typing of CNS was compared with the phenotypic identification. A total of 133 clinical or subclinical quarter cases of intramammary infection caused by CNS from the practice area of the Ambulatory Clinic of the University of Helsinki were studied. Bacteriological diagnosis was based on biochemical (API) testing. Staphylococcus simulans (43.6%) followed by S. chromogenes (23.3%) were the most common CNS species isolated from the milk samples. Ninety-nine isolates were genotyped using AFLP-analysis. Only 75.0% of S. chromogenes and S. simulans isolates identified with API test were clustered with the type strains of these species. Approximately half of the mastitis cases were clinical, and in the majority clinical signs were mild. The severity and persistence of intramammary infection were unaffected by CNS species. Fifty-nine percent of the quarter cases were treated with antimicrobials, and the rest were left without treatment. Mastitis due to beta-lactamase-negative CNS was treated with penicillin G and that due to beta-lactamase-positive CNS with cloxacillin. Nineteen percent of the isolates were beta-lactamase-positive. The bacterial cure rate for quarters treated with antimicrobials was high, 85.9%, as opposed to only 45.5% for untreated quarters. Bacterial cure rates for the most common CNS species or AFLP clusters were not statistically different. Further studies on identification of CNS species are needed.