Remote Sensing of Canopy Photosynthetic Performances: Two Complementary Ways for Assessing the Photochemical Reflectance Index

Two methods have been developed concurrently for hyperspectral measurements of plant canopy reflectance in two narrow wavelength bands centred around 531 and 570 nm. A laboratory-built two-channel radiometer provided an easy and quick estimation of the Photochemical Reflectance Index PRI = (R₅₃₁ − R₅₇₀)/(R₅₇₀ + R₅₃₁) of a plot of alfalfa. A CCD digital camera provided multispectral imaging and the analysis of this index on the same target. The two devices are complementary. The results of measurements are complementary with those of chlorophyll fluorescence induction. This revised version was published online in August 2006 with corrections to the Cover Date.     

浅析微生物学双语教学几个关键问题

专业基础课是衔接大学基础知识和专业知识的重要课程,也是比较难学的课程之一。根据《微生物学》课程的双语教学实践,对生物工程专业的专业基础课中双语教学的教材选择、教学方法、教学内容等几个关键问题展开讨论,并就如何提高双语讲授专业基础课的教学质量进行有益的探讨。     

微生物类课程一体化拓展资源构建与应用

微生物类课程作为高校环境、生物、食品、医学等大类专业的基础支柱性课程,地位极其重要。"互联网+"时代背景下,现代教育技术不断推陈出新,新形态教学发展迅速,在为教学活动注入新鲜血液的同时,切实推进了教育公平,降低了教学成本,并为践行终身学习提供了现实基础和可靠保障。新时期教育工作任重而道远,内涵式发展对课程资源建设提出了新的要求。本文通过剖析高校微生物类课程建设现存问题,结合"教辅书籍、网、端"一体化拓展资源建设与应用实践,就优质微生物类课程教学资源建设,特别是能够与"金课"相匹配的拓展资源打造进行了探索,以期起到抛砖引玉的作用。     

基于“五位一体”新工科智能信息化教学理念的微生物学线上线下混合式教学改革及实践

近年来,在教育部提出的“一流课程”建设背景下,涌现出了大量的混合式课程。作者团队通过近10年的本科生持续课程培养研究及分析,结合理工科院校背景及信息工程领域优势,初步建立起一套适用于当今“互联网+”背景下的“五位一体”微生物学课程混合式教学体系。课程基于新工科特色内容重构,有效打通了生命科学和工科类课程的联系;随后基于多维度信息化资源,为学生提供分层级和多元化的选择方式;线下开展的高阶性教学活动,为学生科研创新能力打下基础;课程中有效融合系统性育人要素,正确树立学生的价值导向;最后利用大数据开展形成性教学评价,为学生的全过程个性化学习质量保驾护航。该课程基于上述内容持续开展的改革和实践,在不断实践探索中取得了较好的成效。     

“医学微生物学”慕课与翻转课堂混合式教学与传统式教学的比较

在"以学生为中心"的课堂教学改革中,需关注的主要问题是学生满意度和学生的表现。北华大学基础医学院"医学微生物学"慕课(Massive Open Online Courses,MOOC)是吉林省精品视频公开课,为充分发挥MOOC的优势,更好体现"以学生为中心"的教学理念,医学微生物学教研室采用基于慕课的翻转课堂(Flipped Classroom,FC)混合式教学模式进行了课堂教学改革。教学团队详细比较了临床医学专业中采用慕课与翻转课堂混合式教学模式与传统讲授模式在"医学微生物学"课程的教学效果,并对学生进行了2种教学方式的学习满意度调查。2组的独立样本t检验结果表明,MOOCFC混合式教学方式未影响学生考试成绩,2种教学模式下学生的表现及这2种教学方法有效性是相同的;成绩分析表明,实验组学生分析问题及解决问题的能力显著提升;调查反馈表明,学生对MOOCFC混合式教学中的自我学习能力与团队协作意识的提高更加满意,并且更喜欢MOOCFC课程所具有的灵活性及主动性。     

基于一流专业建设的应用型示范课程改革与实践：以“临床微生物学检验”课程为例

“双一流”建设的核心是培养一流人才,课程是人才培养的核心要素。应用型示范课程建设是地方普通高等学校培养应用型人才的重要举措,其建设水平直接影响着人才培养的质量。本文以成都医学院“临床微生物学检验”课程为例,围绕课程目标、课程内容、教学手段、课程考核等几个方面介绍了课程的改革与实践。这些改革在教学上更加注重专业知识、实践能力、创新能力、人文素养的培养,突显高素质临床微生物检验应用型人才的培养目标。本课程经过多年的改革与发展,已形成了具有一定特色的医学课程体系,可为地方医学院校应用型示范课程的建设提供参考和借鉴。     

Comparison of the urinary excretion time courses of pyrene-1,6-dione,pyrene-1,8-dione and 1-hydroxypyrene in rats intravenously exposed to pyrene

Abstract

The urinary excretion time courses of pyrene-1,6-dione (P16D), pyrene-1,8-dione (P18D) and 1-hydroxypyrene (1-OHP) were compared in Sprague–Dawley and Wistar rats. Groups of five male rats, of about 200 g of body weight, were injected intravenously with 0.05, 0.5, 5 and 50 µmol pyrene kg^?1 of body weight. Urine was collected at 2, 4, 6, 8, 10, 12, 18, 24, 30, 42 and 48 h post-dosing. Pyrene metabolites were measured by high-performance liquid chromatography (HPLC)/fluorescence after enzymatic hydrolysis of the glucurono- and sulfo-conjugates, extraction on Sep-Pak C18 cartridges and, for the analysis of dione metabolites, derivatization to stable diacetoxypyrene molecules. Over the 48-h sampling period, on average 17.4–25.6% of the injected pyrene was excreted overall as P16D, 6.4–8.8% as P18D and 0.6–0.8% as 1-OHP in the urine of Sprague–Dawley rats. By comparison, on average 10.3–14.7% of the intravenous pyrene dose was recovered as P16D, 4.8–6.4% as P18D and 0.3–0.4% as 1-OHP in the urine of Wistar rats. In both strains of rats there was no clear effect of the dose on the 0–48-h cumulative urinary excretion of P18D and 1-OHP over the entire dose range, while the percentage of dose recovered overall as P16D in urine at the highest dose (50 µmol kg^?1) was statistically lower than at the other doses. The 0–48-h cumulative percentage of pyrene dose excreted as metabolites in the urine of Sprague–Dawley rats was also significantly higher than in Wistar rats (p<0.01) exposed under identical conditions. As for the urinary excretion-time courses of the different metabolites, for a given dose and strain of rats, excretion curves of P16D, P18D and 1-OHP generally evolved in parallel. There was also no clear effect of the dose on the excretion rate, thus half-life, of pyrene metabolites, except for P16D in Sprague–Dawley rats at the highest dose where elimination tended to be slower compared with the other doses (p<0.01). The average first-order elimination half-life of P16D, P18D and 1-OHP was 4.0, 5.7 and 4.1 h, respectively, in Sprague–Dawley rats, and 5.1, 6.1 and 5.1 h, respectively, in Wistar rats (all doses combined but excluding the highest dose for P16D). This study showed the relative importance of metabolic pathways leading to diones compared with 1-OHP. These dioxygenated metabolites appear to be interesting biomarkers of pyrene exposure at environmentally and occupationally relevant doses. Their adequacy as biomarkers of human exposure has yet to be confirmed.     

A comparative study between outcomes of an in‐person versus online introductory field course

The COVID‐19 pandemic has disrupted many standard approaches to STEM education. Particularly impacted were field courses, which rely on specific natural spaces often accessed through shared vehicles. As in‐person field courses have been found to be particularly impactful for undergraduate student success in the sciences, we aimed to compare and understand what factors may have been lost or gained during the conversion of an introductory field course to an online format. Using a mixed methods approach comparing data from online and in‐person field‐course offerings, we found that while community building was lost in the online format, online participants reported increased self‐efficacy in research and observation skills and connection to their local space. The online field course additionally provided positive mental health breaks for students who described the time outside as a much‐needed respite. We maintain that through intentional design, online field courses can provide participants with similar outcomes to in‐person field courses.     

“双一流”背景下非生物专业生命科学实践类系列特色通识课程的建设与探索

生命科学是与人类关系最密切的学科,也是众多科学领域中发展迅速且交叉性强的实验性学科。“双一流”建设背景下,人才培养以全面发展为导向,这对大学生生命科学素养和综合能力的培养提出了迫切需求。以通识课程体系改革为契机,积极探索并成功建设面向非生物专业学生的8门生命科学实践类系列通识课程,课程内容涵盖生命科学的各个分支学科或方向,培养具有生命科学知识和素养并具有一定实践能力和创新能力的复合型人才,可为高校实验教学中心通识课程开设和实验教学改革提供参考和借鉴的经验。     

Effects of benzo(k)fluoranthene exposure on the biomarkers of scallop Chlamys farreri

Scallops (Chlamys ferrari) were cultured for 30 days in seawater containing benzo(k)fluoranthene (BkF) at 0.5, 1.0 and 10.0 microg/L. No effects were noted on 7-ethoxyresorufin O-deethylase (EROD) activity in digestive gland at low concentrations (0.5 and 1 microg/L) of BkF, but BkF increased the glutathione-S-transferase (GST) activity. At 10 microg/L BkF increased EROD activity significantly, and depressed GST activity. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in digestive gland increased significantly in 0.5 and 1 microg/L BkF. In 10 microg/L concentrations of BkF, the activity of three antioxidant enzymes increased first and reached a peak after a few days, before tapering off towards the end of the 30 day exposure. In high concentrations of BkF, activity of three antioxidant enzymes in gill showed an early peak (12 h), before dropping off. Lipid peroxidation (LPO) levels increased along with sampling times, and there were time- and concentration-effects between LPO levels and BkF. The responses of the gills and the digestive gland were not always parallel which can be explained by differences in the bioavailability of the toxicant. The performance of each biomarker is assessed in the context of the role and advantages of selecting a battery of biomarkers for detecting contamination problems. The use of C. ferrari as a sentinel species for biomonitoring potential toxic effects in situ is discussed as well as mechanisms of BKF toxicity and alexipharmic strategies of C. ferrari.