户外教育为基础的高校公共体育教学实践研究*

运用文献资料法、实地考察法、问卷调查法、数理统计法对高校户外教育为基础的公共体育教学中课程结构,教学设计、内容、时间分配及整体教学效果进行了实践检验和分析研究。研究表明,高校公共体育“全人教育”模式具有时代性、可行性和科学性,教学过程不仅注重体验与参与的重要性,也注重学生身体、心理、技术、组织参与等全面素质的培养,课程内容设置科学,课堂时间分配合理,整体教学效果良好,为新时期高校公共体育教育改革提供了借鉴参考。     

不同氮磷浓度对蛋白核小球藻砷富集和转化的影响

氮(N)、磷(P)是影响蛋白核小球藻生长的重要因素,通过改变培养液中N、P的浓度,可能实现对蛋白核小球藻富集砷(As)进行调控。为探讨N、P浓度对这种微藻吸收As的影响是否与其生长变化有关,采用室内培养实验,首先研究不同N、P浓度对蛋白核小球藻生长的影响;进而选择不影响小球藻生长的N(247、24.7 mg·L-1)、P(6、0.6 mg·L-1)浓度组合,设置0.8、8 mg·L-1的亚砷酸盐(As3+)和砷酸盐(As5+)处理3 d,研究N、P浓度对小球藻As富集和转化的影响。结果表明,当P浓度为6 mg·L-1时,N浓度降低到24.7 mg·L-1不会影响小球藻对As3+和As5+的富集及其胞内As形态的转化;而当N浓度为247 mg·L-1时,P浓度降低到0.6 mg·L-1则会显著增加小球藻对As3+和As5+的吸收和富集,藻细胞内As5+还原、甲基化和外排也显著增强。因此,在不影响小球藻细胞生长的条件下,P对其As富集和转化过程的影响比N更为显著。     

Immunohistochemical study on changes in gill Na+/K+-ATPase α-subunit during smoltification in the wild masu salmon, Oncorhynchus masou

Changes in immunoreactivity of Na⁺/K⁺-ATPase -subunit in gill sections of wild masu salmon (Oncorhynchus masou) during the parr-smolt transformation (smoltification) were compared with changes in gill Na⁺/K⁺-ATPase specific activity. Gill Na⁺/K⁺-ATPase specific activity increased from April and peaked in May. Immunohistochemical analysis, using an antiserum against a synthetic oligopeptide based on the conserved region of the Na⁺/K⁺-ATPase -subunit, revealed that immunoreactivity was confined to chloride cells in the surface layer of primary lamellae and the proximal end of secondary lamellae. The size and number of these cells increased gradually from February to May; however, the number of chloride cells of the secondary lamellae decreased in May. These data suggest that the synthesis of Na⁺/K⁺-ATPase and the proliferation of chloride cells occur prior to the elevation of enzyme activity. Moreover, it is likely the proliferation and hypertrophy of chloride cells on primary lamellae prepare smolts for entry into seawater and migration in the ocean.     

The role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem

We evaluated the role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem using the Ecopath/Ecosim approach. As basic input data for the Ecopath/Ecosim model, we used estimates of biomass from bottom trawl surveys and age-structured population models, production/biomass (P/B) ratio, consumption/biomass (Q/B) ratio, diet composition (DC), and fisheries harvests for each component of species or species groups. We estimated the trophic level of each component, niche overlaps among flatfishes, and the impacts of competition and predation on flatfish species in the eastern Bering Sea ecosystem. Based on those estimates, we developed the tropho-dynamic structure of the ecosystem, and the model was used to simulate ecological effects of fishery exploitation patterns. No single flatfish species appeared to have a profound and uniquely important role in the organization and structure of the ecosystem. Instead, the most important component among the guild of flatfish species appeared to be yellowfin sole Pleuronectes asper, which had greater biomass than other flatfish and a relatively diverse diet among the small flatfish species. Pacific halibut Hippoglossus stenolepis, Greenland turbot Reinhardtius hippoglossoides, and arrowtooth flounder Atheresthes stomias were important keystone predators in the eastern Bering Sea ecosystem together with some groups of marine mammals and sea birds. Intra flatfish complex cannibalism was not observed, however, substantial diet overlaps were common in the flatfish guild system.     

粪肥施用对土壤团聚体的影响——Meta分析

粪肥施用为土壤输入大量有机质与养分,能影响土壤团聚体的形成和稳定性,大部分研究主要认为粪肥施用促进土壤大粒径团聚体的形成(marcoaggregate,≥0.25 mm),但进一步细分是对大团聚体(large marcoaggregate,>2 mm)还是小团聚体(small marcoaggregate,2 ~ 0.25 mm)的影响更大,研究存在较大差异。本文使用Meta分析收集了36篇相关文献,共267个团聚体数据,发现施用粪肥能显著增加土壤大团聚体和小团聚体含量,分别增加了95% 和17%,同时减少了土壤微团聚体(microaggregates,0.25 ~ 0.053 mm)和土壤粉黏颗粒(silt-plus and clay-size particles,<0.053 mm)含量,分别减少了14% 和20%。本文还从土壤因素、粪肥因素、气候因素3个角度的解释变量来分析粪肥施用对土壤团聚体影响不同的原因,结果发现土壤类型、土壤pH、粪肥种类和年均气温、年均降水量是造成不同研究结果差异的主要原因。     

植酸酶对不同类型的断乳仔猪日粮粗蛋白、氨基酸和能量的消化率的影响

通过对4个安装了简易T型瘘管的断奶仔猪研究表明,添加植酸酶并没有提高玉米-豆粕型日粮(试验组1)、小麦-豆粕型日粮(试验组2)和大麦-豌豆-菜籽粕型日粮(试验组4)粗蛋白和氨基酸的回肠表观消化率(AID),而使小麦-豆粕-菜粕型日粮的粗蛋白和氨基酸回肠表观消化率或粗蛋白和消化能的总消化道表观消化率(ATTD)得到了显著的提高(P<0.05)或呈提高的势态(P<0.10)。这些结果表明,氨基酸对细菌性植酸酶的反应因子取决于日粮的组成。     

Isolation and molecular characterization of entomopathogenic nematode,Heterorhabditis sp. from an arable land in Nigeria

The occurrence of entomopathogenic nematodes(EPNs) in arable soil samples from Nigeria was investigated using Baermann extraction tray and insect-bait(White's trap) techniques. Isolates were tested for infectivity using the larvae of Galleria mellonella(greater moth) and Tenebrio molitor(mealworm). The study revealed a new species of Heterorhabditis(MT371593) in soil samples that were randomly collected from an arable farmland cultivated with cassava TMS-30572 at the Teaching and Research Farm of Landmark University, Nigeria. Amplification of the internal transcribed spacer region(ITS) of the ribosomal DNA produced a nucleotide sequence of 933 base pairs(bp). A BLASTN search of Gen Bank showed that the sequence of the Nigerian isolate is identical at 99% similarity to that of Heterorhabditis sp. from Thailand. Infectivity test of the isolate showed 100% mortality against T. molitor larvae within 48 h of exposure while only 80% mortality was recorded for G. mellonella after 1 week of exposure. This is the first account of Heterorhabditis sp. in Nigeria. The varying degrees of infectivity against mealworm and greater moth observed in this study proved that the Nigerian isolate of Heterorhabditis sp. could potentially be an attractive option in the management of insect pests of cash crops.     

Viable seeds and spores of weed species in peat soil under pineapple cultivation*

Soil samples were taken from twenty-two fields in a peat area in W. Malaysia where pineapples had been grown for different periods. The numbers of viable seeds and spores in the top 15 cm of fields under cultivation for 6 months, 2, 6 and 10 years varied from 66–122 millions/ha. Of this total, 90% were spores of Nephrolepis biserrata and eight other ferns. The total numbers of seeds of the two sedges, one grass and nine dicotyledons recorded, ranged from 0–7 to 6.3 millions/ha. Les semences et spores viables de mauvaises herbes en sol tourbeux dans des plantations d'ananas Des échantillons de sols ont été prélevés dans vingt-deux champs dans une zone tourbeuse en Malaisie occidentale oü les ananas ont été cultivés pendant des périodes différentes. Les nombres de semences et spores viables dans les 15 premiers centimétres du sol dans les champs mis en culture depuis 6 mois, 2, 6 et 10 ans ont varié de 66 ä 122 millions/ha. Sur ce total, 90 %étaient des spores de Nephrolepis biserrata et de huit autres fougéres. Le nombre total de semences des deux roseaux, de la graminee et des neuf dicotylédones dont la présence dut notée, fut compris entre, 0,7 et 6,3 millions/ha. Lebensfähigen Unkrautsamen und sporen im Moorboden unter Ananas In einem Moor in W. Malaysia wurden aus 22 Feldern die unterschiedlich lang unter Ananas standen, Bodenproben entnommen. Die Zahl an lebensfähigen Samen und Sporen in den obersten 15 cm der Felder, die 6 Monate, 2, 6 und 10 Jahre lang unter Ananas standen, schwankte von 66 bis 122 Millionen je ha. Von dieser gesamten Menge waren 90% Sporen von Nephrolepis biserrata und acht anderen Farnen. Die Gesamtzahl an Samen von zwei Seggen, einem Gras und neun dikotylen Arten, belief sich auf 0,7 bis 6,3 Millionen jeha.