基于DEA的西宁市城市土地利用配置有效性研究

采用数据包络分析(DEA)方法的C2R模型,以每个年度为决策单元(DMU)对西宁市2000～2008年城市土地利用配置有效性进行了有效性评价和分析。计算结果表明:2000～2008年年间西宁市城市土地利用效率整体较高;2003～2008年均表现城市土地利用配置有效,2000～2002年均表现为规模收益递增。以此为依据对西宁提高城市土地利用效率提供参考。     

Effects of estrogen on estrogen receptor expression in the bursal cells of chick embryos and steroidogenic enzymes gene expression in the bursa: Relevance of estrogen receptor and estrogen synthesis in the bursa of chick embryos

Estrogen has been reported to act on B cell genesis in the bursa of Fabricius of chick embryos. In this study, we attempted to demonstrate the hypothesis that B cell genesis is controlled by estrogen receptor (ER) in the bursal cells and steroidogenic enzymes synthesized in the bursa. We previously reported the presence of estrogen receptor α (ERα) in the bursa during the late stage of embryogenesis and an increase in the expression of ERα messenger RNA (mRNA) between the 13th day and 16th day. The number of ER-positive cells was maximal on the 16th day. In the present study, ER-positive cells in the bursa during the late stage of embryogenesis increased 4 h after β-estradiol treatment on the 14th to 18th day. The concentration of β-estradiol in the embryonic bursa increased. These results suggest that this stage of embryogenesis is critical in B cell development in the bursa in connection with the effect of estrogen treatment. Our findings also showed that the mRNA expression of five steroidogenic enzymes occurred in the bursa of chick embryos. These results suggest that estrogen is synthesized in the embryonic bursa and estrogen acts on the bursal cells in a paracrine fashion.     

卡那霉素对108杨不定芽诱导的影响

以108杨为试材,以茎段、叶柄、叶片3种外植体的高效不定芽诱导再生为基础,研究了不同梯度浓度卡那霉素(Km)对108杨不定芽诱导的影响。结果表明:茎段外植体对Km表现出较高的耐受性,叶柄和叶片外植体的敏感性高;在遗传转化过程中70mg/L的Km作为茎段外植体的临界筛选浓度较为合适;对于叶柄和叶片外植体,选择30mg/L的Km临界筛选浓度较为合适。     

黑木耳新品种“吉耳1号”的区域试验

2009年,在科技部的农业科技成果转化资金资助下,对"吉耳1号"品种在该年度春季和秋季分别做了的区域试验。结果表明:利用周转棒封口,提高了生产效率,降低了菌袋的污染率,提高了菌袋的成品率,污染率降至2%以下。"吉耳1号"每万袋平均产量为460.3kg,比对照增产13%,经济与社会效益显著,具有极好的推广价值。     

江西乐安红豆杉林蜘蛛资源调查

江西省乐安红豆杉林位于东经115.49,北纬27.25,近千棵红豆杉与针叶林、宽叶林、灌丛和草丛等共同形成了红豆杉林植物群落.通过调查共获得蜘蛛标本234份,经鉴定计24科61属73种,其中2种为江西新记录种,另有新种2种.     

Emerging forests on abandoned land: Puerto Rico’s new forests

The species composition of forests change continuously as the earth’s biota evolves and adjusts to environmental change. Humans are accelerating the rate of species turnover by moving species around the planet and dramatically changing environmental conditions. Our focus is on new forests in Puerto Rico that emerge naturally on abandoned lands previously converted to agriculture and degraded. These forest stands have combinations of species that are new to the island’s landscapes. New forests exhibit high species dominance during forest establishment, which includes dominance by alien tree species. These alien tree species establish and maintain forest cover, which may facilitate regeneration of native tree species. Landscape analysis and literature review revealed that these emerging stands are highly fragmented (60% were <1 ha in 1991), function as refugia for native organisms, and at 60–80 years old have similar species richness and structural features as native stands of similar age. However, the island’s new forests exhibit important differences from mature native forests on unconverted forestlands. New forests have fewer endemic species and fewer large trees (≥55 cm dbh) than mature native forests; they have higher soil bulk density and lower soil carbon and litter stocks; and they accumulate aboveground biomass, basal area, and soil carbon more slowly than native forests of similar age. We suggest that new forests will become increasingly prevalent in the biosphere in response to novel environmental conditions introduced to the planet by humans.     

运用Cytb 和12s rRNA 基因鉴别梅花鹿(Cervus nippon)和马鹿(Cervus elaphus)的研究

本研究介绍了运用细胞色素b基因和12s核糖体RNA基因部分序列的系统学和核甘酸距离分析来鉴别降解的梅花鹿和马鹿样品。采用PCR和直接测序技术获得了8份嫌疑样品402bp细胞色素b基因序列,并与来自GenBank数据库27份同源的细胞色素b基因序列进行比对。3份嫌疑样品与梅花鹿的核甘酸距离值相同(0.026±0.006),小于梅花鹿与东部马鹿间最小的核甘酸距离值(0.036)。并且梅花鹿和马鹿的系统学分析表明这些样品与梅花鹿聚为一枝,因此可以推测它们来源于梅花鹿。同样的方法得出另3份嫌疑样品来源于马鹿。该结果被387bp12s核糖体RNA基因序列的系统学和核甘酸距离分析进一步证实。该方法是有效的,花费的时间少,能帮助减少同类野生动物案件的发生。图2表1参13。     

明末清初江南“秦淮八艳”园林生活探究

明末清初江南青楼才女拥有丰富的园林生活,其本身亦和园林环境共同组成文人名士的审美价值体现。同时,园林空间也是其一生境遇的环境背景。基于对江南青楼才女"秦淮八艳"园林生活的探究,概括其园林生活包含私家园林生活、青楼园林生活和公共园林及自然山水生活,并总结出其园林生活具有文人化、神秘化、男性化的特点,从而对中国古典园林史中女性生活与园林环境关系现有研究进行补充,引发对明末清初女性园林文化的思考和探讨。     

Spatial dispersion of trees in an old-growth temperate hardwood forest over 60 years of succession

An analysis of spatial dispersion was conducted for individual tree species in the old-growth forest at the Davis-Purdue Research Forest in Indiana. This 20.6 ha stand has been left largely undisturbed by exogenous factors since its acquisition by Purdue in 1917. It is the only long-term study plot of its size for a temperate hardwood forest with x–y coordinates (rectangular plot) for all species above 10 cm diameter. Full censuses have been conducted spanning 60 years (1926, 1976 and 1986).

Ripley’s L(t) function revealed that most species are characterized by some form of aggregation, agreeing with a prior evaluation from 1981. Heterogeneity of spatial structure was evident between two large plots, indicating that differences in site quality and history had influenced spatial structure. Shade-intolerant species were numerically dominant and spatially aggregated in 1926 but have declined over the 60-year interval and become more random in spatial dispersion. Shade-tolerant species have increased in number and become more aggregated over time, or they exhibit little change in spatial structure. Examples of the latter include Acer saccharum and Ulmus americana, species that experienced explosive population growth. These contrasting patterns are masked by stand-level patterns that show a trend toward uniformity over the same time frame.

These data reveal that changes in dispersion accompany the demographic failure experienced by numerous tree species in Central Hardwood old-growth stands, and these changes may feed back into a negative population cycle and further impede regeneration. The simultaneous manipulation of dispersion and density should be considered as a tool for influencing forest succession and promoting regeneration of desired tree species.