淡淡妆，自然样

十五年的光阴把每个同学都推向成熟，也把年轮印在每一张曾经年轻的脸上。十五年足以把一些漂亮的女孩变成地道的家庭妇女，可是，谁也没想到，会把当年的丑小鸭变成一只白天鹅。

Effects of Organic Enrichment on Sandy Beach Meiofauna:A Laboratory Microcosm Experiment

Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three different treatments including non-organic addition as the control, low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL). After 21 d, the meiofauna richness decreased in both organic enrichment treatments. Among the three treatments, total meiofauna abundance was significantly different, and the control groups had higher abundance than the other two treatment groups. However, the responses of the meiofauna abundance in the two organic enrichment treatments were non-significantly different. The relationship of meiofaunal abundance and nematode/copepod ratios to organic matter and oxygen level in the microcosm experiments were discussed.

Substrate selection and seasonal variation in abundance and size composition of isopod Lirceus fontinalis in Ontario streams, Canada

The abundance and size composition of stream isopods Lirceusfontinalis were investigated from April 2001 to August 2002 in 3 streams in southem Ontario, Canada. Effects of current speed was released from the analysis by choosing slow flowing water. The effects of substrate, season and water depth on the abundance, distribution and size composition of the isopods were analyzed. It was found that substrate and season influence isopods the most. The rocky substrate with attached filamentous macro-algae contains an isopod abundance 7.05 times that of bare rock substrate and 14.6 times that of free-sand and mud substrate. There was a large variation with respect to seasonali .ty in both abundance and size composition of the isopods, with the highest abundance occumng in summer and the lowest in winter and spring; individual isopods also tend to be larger in the winter and spring. In all substrates, shallow areas tend to support higher densities of isopods than deeper areas.

Comparison of Meiofaunal Abundance in Two Mangrove Wetlands in Tong'an Bay, Xiamen, China

To compare meiofaunal community in the two mangrove wetlands in Tong＇an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang＇an mangrove wetlands in the bay. The results showed that the Ne/Co ratio （nematode to benthic copepod） and organic matter in Fenglin mangrove wetland were higher than those in Xiang＇an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang＇an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang＇an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and regionxseason. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang＇an wetland＇s level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.

The Effect of Selective Logging on the Nest Density, Foraging Range and Colony Size on the Ground-Dwelling Ant Aphaenogaster Swammerdami Forel, 1886 in Kirindy ForestmMadagascar

Studying the ecology of ants can be a powerful tool for conservation, While the effect of logging is mainly investigated by the comparison of species richness and composition, the impact on individual species are often neglected. This study investigated the effect of selective logging on the nest density, foraging range and colony size on the ground-dwelling ant Aphaenogaster swammerdami in Kirindy forest--Madagascar. This ant is a common ground-dwelling species in Kirindy, a western dry deciduous forest of Madagascar. Sampling was done in two sites of the forest： One part that was selectively lodged and another that have not been logged. Here we show that selective logging led to a decrease in colony size and density, while the foraging range seemed to be unaffected. Higher desiccation stress and lower food availability in the logged forest are most likely to be responsible for these results.

Impact of Cutting a Clover Crop on the Nitrogen Supplied to Winter Wheat in an Intercropping System

The major function of clover in a winter wheat–white clover intercropping system is to supply nitrogen （N） for the wheat. A field experiment was conducted at Yucheng Comprehensive Station of the Chinese Academy of Sciences, to evaluate the effect of cutting white clover on N fixation and the transfer of fixed N to the associated winter wheat. A method of 15N natural abundance was used to determine the nitrogen dynamics in the intercropping system. The results showed that the amount of N transferred from the clover to the wheat, throughout the growing season, varied between 34.4 and 57.5 kg ha-1. Compared to leaving the clover standing, cutting the clover increased the amount of N that accumulated in the soil and also resulted in reduced N concentrations in the leaves and stems of the wheat. Using the cut clover as mulch between wheat rows led to decreased N concentrations in the wheat plants’ leaves and stems. The present study provides preliminary information on the amount of N transferred from clover to wheat in an intercropping system.

Natural ^(15)N Abundance in Winter Wheat Amended with Urea and Compost: A Long-Term Experiment

We investigated 15N abundance （δ15N） of winter wheat （Triticum aestivum cv. Jinmai 1） plants and soil at different growth stages in a field with a 13-year fertilization history of urea and compost, to determine whether or not the δ15N of plant parts can be used as an indicator of organic amendment with compost. Plant parts （roots, leaves, stems and grains） and soil were sampled at re-greening, jointing, grain filling and mature growth stages of winter wheat. There were significant differences between the urea and compost treatments in 815N of whole plants, plant parts and soil over the whole growing season. Determination of the δ15N of plant parts was more convenient than that of whole plant to distinguish between the application of organic amendment and synthetic N fertilizer.

Effects of subchronic oral toxic metal exposure on the intestinal microbiota of mice

Oral exposure to toxic metals such as cadmium （Cd）, lead （Pb）, copper （Cu） and aluminum （AI） can induce various adverse health effects in humans and animals. However, the effects of these metals on the gut microbiota have received limited attention. The present study demonstrated that long-term toxic metal exposure altered the intestinal microbiota of mice in a metal-specific and time-dependent manner. Subchronic oral Cu exposure for eight weeks caused a profound decline in gut microbial diversity in mice, whereas no significant changes were observed in groups treated with other metals. Cd exposure signif- icantly increased the relative abundances of organisms from the genera Alistipes and Odoribacter and caused marked decreases in Mollicutes and unclassified Ruminococcaceae. Pb exposure significantly decreased the abundances of eight genera： unclassified and uncultured Ruminococcaceae, unclassified Lachnospiraceae, Ruminiclostridium_9, Rikenellaceae_RCg_gut group, Oscillibacter, Anaerotruncus and Lachnoclostridium. Cu exposure affected abundances of the genera Alistipes, Bacteroides, Ruminococcaceae_UCG-014, AUobaculum, Mollicutes_RF9_norank, Rikenellaceae_RCg gut_group, Ruminococcaceae_unclassified and Turicibacter. A1 exposure increased the abundance of Odoribacter and decreased that of Anaerotruncus. Exposure to any metal for eight weeks significantly decreased the abun- dance of Akkermansia. These results provide a new understanding regarding the role of toxic metals in the pathogenesis of intestinal and systemic disorders in the host within the gut microbiota framework.

THE IMPLEMENTATION OF A BALANCED READING INSTRUCTION IN TAIWAN

The purpose of this study is to explore the effects of the balanced reading program on the elementary school students in Taiwan. The participants were 36 fifth graders in Taiwan. The researchers chose suitable picture books as teaching materials and made use of them to design a balanced reading program. The program combines the ideas of whole language and phonics rules. Whole-part-whole structure was used in the teaching process. The teaching of the balanced reading program lasted for nine weeks. The questionnaire of learning feedbacks, the questionnaire of reading activities, the teacher's journal, interviews with teachers and students were used to gather data. Six facts were found after the analysis of the data: (1) Among the picture books, 'Seven Blind Mice' and 'Snow' were chosen by the students as their favorite. (2) Most students liked the reading activities for this semester. (3) The students made progress in reading ability and reading techniques. (4) The frequency of the students' reading English storybooks increased. (5) Most students were willing to read English storybooks after the program. (6) The table of self-evaluation didn't work well. Some suggestions have been provided according to the findings.