Predation impact of Leptodora kindtii on population dynamics and morphology of Bosmina fatalis and B. longirostris in mesocosms

1. We assessed the impact of predation by the invertebrate predator Leptodora kindtii on Bosmina longirostris and B. fatalis, which show seasonal and reciprocal succession patterns in Lake Suwa, in a mesocosm experiment using 20‐L tanks with or without the predator under different food conditions. We also analysed morphological responses of the two Bosmina species to the predator in the tanks. 2. Bosmina fatalis dominated B. longirostris regardless of predator presence under high food density. However, the presence of Leptodora induced the dominance of B. fatalis more rapidly than its absence. On the contrary, no dominance of B. fatalis was observed in tanks with low food density, irrespective of the presence of the predator. Only B. fatalis showed morphological changes in response to the presence of Leptodora. 3. Mucrone length and antennule shape (angle between body and antennule and angle between antennules) showed marked responses at both high and low food densities, but antennule length responded only at high food density. Mucrone length seems to be a more effective defence against Leptodora. 4. The results suggest that B. fatalis is a superior competitor against B. longirostris and is more resistant to Leptodora predation, especially in good food conditions. The repeatedly observed seasonal succession of the two Bosmina species in the eutrophic Lake Suwa – the replacement of B. longirostris by B. fatalis following the occurrence of abundant Leptodora– seems to be caused by the selective predation of Leptodora on B. longirostris as well as the competitive ability of B. fatalis.     

达斡尔族成人的体格,体型及半个多世纪来的变化

对内蒙古自治区莫力达瓦族３５３名（男１８７,女１６６）２０－６０岁达斡尔族进行了活体观察与测量,总结了达斡尔族的体格特征和类型。并在城乡之间和与半个世纪以前同一地区达斡尔族的体质资料之间进行了比较。     

蛇胆祛痰作用的实验研究

用２组小鼠,每组１０只。实验组用蛇胆酒灌胃,对照组用生理盐水灌胃,均以气管内酚红排泄法观察。结果示,酚红排泄量实验组比对照组明显为高。说明蛇胆确有增加小鼠气管分泌,稀释痰液的作用     

云南热带种子植物区系

云南热带是指云南东南,南极西南的沿边热带地区,其地理范围在现今热带雨林及热带季雨林分布的区域。其种子植物区系有４９１５种,隶属于１４４７属和２４８科,基本上是热带北缘性质但同时明显表现出向亚热带过渡的特点。经分析,云南热带东西两侧的地理联系,替代现象、特有现象和区系起源和演化上有很大差异。其原因可能有不同地史背景。因此,将云南热带东西两侧划分古热带植物区中两个不同的植物区系地区是合理的,但其范围和     

Stream-dwelling insects and extremely low frequency electromagnetic fields: a ten-year study

Changes in the structure of benthic insect communities at an experimental site and at a reference site in the Ford River, Michigan were monitored over a 10-year period to determine whether extremely low frequency electromagnetic fields (ELF) affected those communities. Five of 10 biotic parameters monitored are presented: taxon evenness (J), richness (S), numerical dominance of chironomids, and total insect mass. Data were separated into three seasons because coefficient of variation values were lower in the summer than in the spring and fall. Two-way ANOVA tests for the biotic variables were often significantly different between sites and among years, but the interaction terms were less frequently significant. Biotic parameters were regressed against stream discharge, water temperatures, years, and ELF cumulative ground field exposures. At the experimental site, discharge accounted for more variation than did water temperature or years for all biotic parameters except chironomid numerical dominance in the fall. Intervention analyses, using the B.A.C.I parametric or the R.I.A non-parametric showed significant differences in three of 15 cases; namely, for the highly varying chironomid numerical dominance values in the spring and fall and for the low varying total insect mass values in the summer. For those tests, the Before Impact period spanned April 1984 through May 1986. The After Impact period (full ELF power) spanned June 1989 through August 1993. Trend analysis for total insect mass at the experimental site in the summer showed discharge to be more important than water temperatures or ELF ground field exposures. Natural physical factors appear to be more important than the anthropogenic ELF fields in accounting for seasonal and yearly changes in the community.     

Evaluation of PAPNET-assisted cervical rescreening

Evaluation of PAPNET-assisted cervical rescreening
We have compared the results of targeted manual rescreening of 1211 randomly selected smears with the results of PAPNET-assisted rescreening of 1613 cervical smears, containing at least 6.3% low-grade squamous intraepithelial lesion (SIL). PAPNET diagnosis and the targeted rescreening diagnosis were compared with the initial report, issued on the corresponding smear. Reproducibility scores for inadequacy, presence of endocervical and endometrial cells, specific infections and squamous cell abnormalities were determined. The reproducibility scores for the diagnosis of inadequate smears and specific infections were lower with the PAPNET-assisted rescreening. The detection of squamous cell abnormalities was excellent for both methods (>0.95), with a higher detection rate for false-negative smears with the PAPNET testing system.     

Chemical control of vine weevil larvae on container-grown hardy ornamental nursery stock 1986–1989

In a search for alternatives to the former standard aldrin compost incorporation treatment for control of vine weevil (Otiorhynchus sulcatus) larvae on container-grown hardy ornamental nursery stock, a series of 87 tests of insecticides were done at four experimental centres of the ADAS (Leeds, Reading, Wolverhampton and Wye) from 1986 to 1989. Insecticidally-treated plants and untreated controls were artificially infested with vine weevil eggs at varying intervals before and after treatment, and the survival of the pest was assessed. Aldrin treatment gave consistent and excellent preventive control of vine weevil larvae for over 2 years. Of the candidate materials tested, a slow-release granular formulation of chlorpyrifos incorporated into compost at a dose rate of 100 g a.i. m^-3 of compost gave good control for up to 34 wk after treatment (the longest period evaluated) and a micro-encapsulated slow release formulation of fonofos incorporated at a dose rate of 43.3 g a.i. m^-3 usually gave good control for up to two years (the longest period evaluated). Surface applications of these two organophosphates or of carbofuran granules, though sometimes effective, were unreliable as either preventive or remedial treatments even for short term control.     

Variability of genetic serum protein markers in Austria

Haptoglobin (HP), transferrin (TF), group specific component (GC) and protease inhibitor (PI) polymorphisms were studied in a population sample (n=272) from Tyrol (Austria). Comparing the allele frequencies of these polymorphic serum protein systems with those reported on other Austrian population samples some heterogeneity in the regional distribution of allele frequencies was seen, especially concerning the GC system. The reasons for that may be due to different historical backgrounds in the various regions of Austria.     

高苯丙氨酸血症大鼠脑内单胺类递质的研究

以3d龄Sprague-Dawley大鼠腹腔注射苯丙氨酸(Phe)诱导高苯丙氨酸血症,荧光法测定大脑皮层及其突触体中去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)含量;Y型电迷宫法测其学习记忆能力.结果显示:高苯丙氨酸血症大鼠大脑皮层NE、DA及5-HT含量降低38.6%～67.4%,突触体中NE、DA和5-HT含量降低51.9%～70.2%,学习记忆能力明显低于对照组.结果提示,苯酮尿症智力障碍可能与大脑皮层及其突触体中某些单胺类递质含量降低相关.     

Duration of the breeding season and response to reproductive manipulation in five breeds of sheep under northern prairie conditions

The breeding season was 157, 154, <126, 210 and 217 days for Rambouillet, Columbia, Suffolk, Rambouillet x Finnish Landrace and Columbia x Finnish Landrace ewes respectively. Treatment of cyclic ewes with pregnant mare serum gonadotropin (PMSG) (500 IU), following a 12-day treatment with progestin-containing intravaginal sponges, did not affect fertility, but did decrease the time from sponge removal to estrus, (control 48.0 +/- 3.1 hr; PMSG 39.4 +/- 1.8 hr) to the preovulatory surge of LH (control 52.7 +/- 2.8 hr; PMSG 39.0 +/- 1.7 hr) and FSH (control 52.3 +/- 2.9 hr; PMSG 42.8 +/- 1.6 hr) and caused an elevation of serum LH levels prior to the preovulatory surge (control 1.25 +/- 0.18 ng/ml; PMSG 2.31 +/- 0.22 ng/ml). Exposure of the purebred ewes to 18 hours of daylight in January, decreasing by 30 minutes a week subsequently, counteracted the seasonal reduction in the number of ewes lambing following induced breeding under natural daylight in May. Prolificacy was greatest in crossbred ewes and their fertility was not affected by season. Gestation period was longer for fall-bred ewes and varied with breed.