秦巴山区生态农业类型及效益

陕西省安康地区位于全国最大的一块贫困片秦巴山区,北靠秦岭主脊,南踞大巴山北坡,汉水横贯其中,形成“两山夹一川”的地貌特征。全地区总面积２．３３９１×１０４ｋｍ２,其中耕地和水域面积约各占１０％,林地和荒山面积约各占４０％。特别是荒山面积平均一人０６１ｈａ,可利用的土地资源十分丰富。据调查和国土资源资料分析,在山区有３０％～４０％的农户单家独居,其居住的方圆土地规模一般为２００～２６７ｈａ,多的可达６６７ｈａ以上,形成一户一条沟,一户一条梁,一户一面坡的人口与土地资源的分布格局。在农业生态…     

口服乐腹康胶囊活菌制剂对人体肠道菌群的影响

本文报道了口服乐腹康胶囊活菌制剂对正常人体肠道的双歧杆菌、乳杆菌、大肠杆菌等的影响。结果显示口服后,对肠道菌群有短暂（１～２天）抑制生长作用,而后对厌氧菌中的双歧杆菌、乳杆菌有明显促进生长的作用。双歧杆菌在服药前平均为５０６±１０３亿／克,服药后１０天升至１８７３±１４３亿／克,增长３７０倍（Ｐ＜００５）,有显著性差异。乳杆菌服药前平均数为２７４±０２５亿／克,服药后１０天升至５０７±１２１亿／克,增长１８５倍。而对需氧的大肠杆菌和其他肠道球菌有持续的抑制作用,大肠杆菌服药前平均数为３４２±０２１亿／克,服药后１０天降至１０５±００９亿／克,仅为原来的３０％（Ｐ＜００５）,有显著的差异     

长白松人工林群落生物量和生产力的研究

应用相对生长法和样方收获法对长白松人工林群落的生物量和生产力进行研究．结果表明,群落总生物量和总净生产量分别为１１１．９８２ｔ·ｈａ－１和８９４２·８０ｋｇ·ｈａ－１·ｙｒ－１,其中乔木层、灌木层和草本层生物量和净生产量分别为１０６．１５０、２．２３０和２．２６４ｔ·ｈａ－１及７４６５．００、２２３．００和１１８２．００ｋｇ·ｈａ－１·ｙｒ－１,分别占总量的９４．７９、互．９９和２．０２％及８３．４７、２．４９和１３．２２％,凋落层生物量０．３６４ｔ·ｈａ－１,立枯量０．９７４ｔ·ｈａ－１．经分析可得,长白松人工林急待进行抚育间伐,调整群落产量结构,提高森林生态系统的整体功能,培育优良速生丰产林．     

商陆皂甙的抗胃溃疡作用

观察了不同剂量的商陆皂甙对大鼠幽门结扎型、醋酸型及小鼠利血平型胃溃疡的影响。实验结果,商陆皂甙Ａ组（１８０ｍｇ／ｋｇ）对三种胃溃疡的溃疡指数分别为０５６±０５３（面积ｍｍ２）;７１８±３３９（面积ｍｍ２）,３３６±１２７（容积μｌ）;１６７±２１８（小溃疡）,１７８±２１１（出血点）,比对照组小,（Ｐ＜００５）。溃疡抑制率分别为６７％;５４４４％（面积ｍｍ２）,５５８９％（容积μ１）;８４４％（小溃疡）,８３８％（出血点）。提示：商陆皂甙（１８０ｍｇ／ｋｇ）对胃溃疡有一定抑制作用。     

马铃薯离体再生及人工种子研究

马铃薯３个品种虎头,克４和Ｆａｖｏｒｉｔａ的茎叶外植体在ＭＳ＋１ｍｇ／ＬＮＡＡ＋１ｍｇ／ＬＢＡ培养基上形成愈伤组织。在ＭＳ＋０２ｍｇ／ＬＮＡＡ＋１ｍｇ／ＬＢＡ培养基上,愈伤组织分化产生不定芽。在ＭＳ＋００５ｍｇ／ＬＮＡＡ培养基上,不定芽生根形成再生完整植株。０２～０３ｃｍ大小的不定芽反复继代可持续增殖。有３个以上叶片的不定芽在ＭＳ＋５ｍｇ／ＬＢＡ＋００５ｍｇ／ＬＩＢＡ培养基上和黑暗条件下,在侧芽或顶芽部位形成微型薯。用４％海藻酸钠和２％氯化钙溶液包裹０２～０３ｃｍ大小的不定芽或直径为０２～０３ｃｍ的微型薯制成微芽人工种子和微薯人工种子。在４℃下贮存２个月后,微芽人工种子和微薯人工种子在有菌腐殖土壤中播种２１ｄ的萌发率分别是１５７％和９６２％。     

真养产碱杆菌二级连续培养系统中稀释率对聚β—羟基丁酸合成的影响

在研究真养产碱杆菌ＷＳＨ３一级连续培养动力学的基础上,采用二级连续培养系统对不同稀释率下聚β羟基丁酸的生产进行了研究。结果表明：在一级连续培养系统中,当稀释率为０２１ｈ－１时,细胞干重最大值达２７１ｇ／Ｌ;二级培养系统中,稀释率为０１４ｈ－１时细胞干重最大值为４７６ｇ／Ｌ;在稀释率为０１２ｈ－１时,ＰＨＢ的生产强度达到最大值为２５０ｇ／（Ｌ·ｈ）,但胞内ＰＨＢ含量仅为４７６％;在稀释率为００７５ｈ－１时,产物对基质的转化率达到最大值为０３８ｇ／ｇ,此时ＰＨＢ的生产强度达２１４ｇ／（Ｌ·ｈ）和胞内ＰＨＢ含量±７２１％;随着细胞比生长速率的增长,细胞中ＰＨＢ含量和单位菌体合成ＰＨＢ的量不断下降。     

蜂胶的乙醇提取物对小鼠体表螨虫的净化研究

用０１％、０３％、０５％和０７５％四种不同浓度的蜂胶乙醇提取物（ＬｉｑｕｉｄｏｆＥｔｈａｎｏｔＥｘｔｒａｔｅｄｆｒｏｍｐｒｏｐｏｌｉｓ）ＥＥＰ来净化自发感染螨虫的ＩＣＲ小鼠。发现不同浓度的ＥＥＰ对体表螨虫均有不同程度的净化作用,但０５％浓度的ＥＥｐ净化效果最佳。净化后的小鼠精神状态较好,被毛光洁贴身,无异常反应,镜检未查见螨虫。结果表明ＥＥＰ天然、无毒〔１〕,价廉易得,是一种高效、简便、理想的实验动物体表螨虫的生物净化剂。     

川西平原大足鼠的种群生态学Ⅰ.种群动态和个体大小

我们利用标志重捕、夹捕解剖和笼养等三种方法于１９８９年１月至１９９５年６月对川西平原的大足鼠的种群密度、个体大小、生长和生物量进行了研究。种群密度最高１１．３只／ｈａ,最低０．７只／ｈａ,平均３．６只／ｈａ,并显示出与农作物相同的季节变动特征。雌雄性比由幼年组和亚成体组约１：１到成体组１：０．７８到老年组１：０．５３。雌雄个体的平均质量分别为１３６ｇ和１１４ｇ,两性的个体质量和后足长有明显差异,体长和耳长差异不明显。饲养的幼体及亚成体个体质量和尾长均持续增长,并可分别用Ｌｏｇｉｓｔｉｃ和对数方程较好地拟合。生物量则显示出比种群密度和个体质量更稳定的特征。     

北京地区184例健康人肠道菌群值的调查

本文对北京地区１８４例７－６９岁健康人的粪便菌群中的肠杆菌、肠球菌、拟杆菌、产气荚膜梭菌、双歧杆菌、乳杆菌等６种细菌进行了培养、计数和鉴定。结果表明：肠杆菌６０７±１８０、肠球菌６１３±１４５、拟杆菌４５７±１７７、产气荚膜梭菌４０６±１５２、双歧杆菌８３２±０９６、乳杆菌７８２±０８６（ＬｏｇＮ／克便）;男性和女性相比,除产气荚膜梭菌男性明显高于女性（Ｐ＜００５）外,其余５种菌均无显著性差异;７－１８岁年龄组肠杆菌极显著地低于平均值（Ｐ＜００１）,６１—６９岁年龄组双歧杆菌明显低于平均值（Ｐ＜００５）;双歧杆菌与肠杆菌之比Ｂ／Ｅ值,７－１８岁年龄组是６１－６９岁年龄组的５７５倍     

海甘蓝愈伤组织再生植株的研究

海甘蓝种子在附加有２～５ｍｇ／Ｌ６－ＢＡ＋０１ｍｇ／ＬＮＡＡ的ＭＳ培养基上,幼苗生长健壮。幼苗的下胚轴和子叶柄在ＭＳ＋１ｍｇ／Ｌ２,４－Ｄ＋０５ｍｇ／Ｌ６－ＢＡ的培养基上可以获得较好的愈伤组织。将来源于下胚轴的愈伤组织培养于含有０５ｍｇ／ＬＮＡＡ,２ｍｇ／Ｌ６－ＢＡ的ＭＳ培养基上分化出的丛生芽状态最好。最佳生根培养基为１／２ＭＳ＋０５ｍｇ／ＬＢＡ。     

马尾松毛虫灾变发生类型与地貌及植被特征间对应分析

1　引　　言对应分析 (ｃｏｒｒｅｓｐｏｎｄｅｎｃｅａｎａｌｙｓｉｓ)由法国Ｂｅｎｚｅｃｒｉ于1970年首先提出 ,是在Ｒ型和Ｑ型因子分析基础上发展起来的一种多元分析方法[5] .它与主成分分析有着密切的联系 ,在某种意义上可以看成是主成分的特殊情形 ,从另外一种意义上讲 ,它又是主成分分析的推广 .另外 ,它和典型分析也是相通的[4 ] .对应分析的主要目的是寻求列联表行因素和列因素的基本分布特征和最优联立表示 ,并将彼此间的结构关系直观地展示出来 .对应分析已被用于生物学研究的不同领域[2 ,3 ] .本文应用对应分析方法 ,对小班 (ｓ…     

Applications of Background Data in Ecological Risk Assessment: Various Shades of Gray

This paper discusses general approaches for evaluating the utility and manner of conducting background analyses in soil for ecological risk assessments. The types and sources of background data are discussed, and advantages and disadvantages of using literature-based versus site-specific background data are presented. The value of background evaluations is discussed with regard to the goals and objectives for a project. A comparison of literature-based ecological soil screening levels with generic metal background concentrations is presented to illustrate a typical problem in incorporating background data in ecological risk assessments, which is that many generic background concentrations are higher than ecological screening levels. This brings into question both the relevance of ecological screening levels and generic background levels. These issues are discussed along with cost-benefit considerations in an attempt to provide recommendations for determining the most appropriate type of background evaluation to conduct at a given site.     

Reduced abundance of insects and spiders linked to radiation at Chernobyl 20 years after the accident

Effects of low-level radiation on abundance of animals are poorly known. We conducted standardized point counts and line transects of bumble-bees, butterflies, grasshoppers, dragonflies and spider webs at forest sites around Chernobyl differing in background radiation by over four orders of magnitude. Abundance of invertebrates decreased with increasing radiation, even after controlling for factors such as soil type, habitat and height of vegetation. These effects were stronger when comparing plots differing in radiation within rather than among sites, implying that the ecological effects of radiation from Chernobyl on animals are greater than previously assumed.     

How ecological indicators construction reveals social changes—The case of lakes and rivers in France

Social and scientific factors are deeply enmeshed in each other within the development and the use of ecological indicators (EI). Yet low research has assessed which factors contribute to selecting ecological indicators on the long-term. This article proposes to study the historical construction of EI by examining ecological, political, and social background of specific places where EI were developed, in France on lakes and rivers. Our major findings in France were that ecological indicators were never optimised for the present market or political arena. Instead EI development was typically recycling previous tools that were elaborated for other purposes by environmentally committed outsiders, without regular funding. We found that regular funding for monitoring an EI was only provided when it matched an institution's goal. Beyond the geographically limited relevance of the case studies, these results therefore improve the theoretical framework we deploy when constructing or relying on indicators.     

Active remodelling of the TIM23 complex during translocation of preproteins into mitochondria

The TIM23 (translocase of the mitochondrial inner membrane) complex mediates translocation of preproteins across and their insertion into the mitochondrial inner membrane. How the translocase mediates sorting of preproteins into the two different subcompartments is poorly understood. In particular, it is not clear whether association of two operationally defined parts of the translocase, the membrane-integrated part and the import motor, depends on the activity state of the translocase. We established conditions to in vivo trap the TIM23 complex in different translocation modes. Membrane-integrated part of the complex and import motor were always found in one complex irrespective of whether an arrested preprotein was present or not. Instead, we detected different conformations of the complex in response to the presence and, importantly, the type of preprotein being translocated. Two non-essential subunits of the complex, Tim21 and Pam17, modulate its activity in an antagonistic manner. Our data demonstrate that the TIM23 complex acts as a single structural and functional entity that is actively remodelled to sort preproteins into different mitochondrial subcompartments.     

考虑滑坡敏感性的天津市蓟州区生态网络构建

随着城镇水平不断提高,人口数量不断增加,滑坡、崩塌等地质灾害频发,天津市蓟州区的景观孤岛化和破碎化现象日益严重,生物多样性减少,生态价值和生态服务功能降低。以天津市蓟州区为研究区,从自然资源、气候调节、水源涵养、生物多样性等方面考虑,选取生态源地;选取坡度、地形起伏度、坡向等滑坡孕灾环境因子,基于信息量模型,在定量分析滑坡与各孕灾环境因子关系的基础上通过地图代数计算滑坡敏感性指数,并用于修正由土地利用类型赋值得到的生态基本阻力面,基于最小费用模型提取研究区生态廊道,进而构建天津市蓟州区生态网络。研究结果表明:研究区内滑坡的空间分布主要受坡度、高程、地形起伏度以及岩土类型等因素的控制;经验证基于信息量模型计算得到的滑坡敏感性指数对研究区内的滑坡具有较强的诊断能力;基于最小费用模型,提取生态廊道23条,总长度约为129 km。通过对比分析,提取的生态廊道基本上避开了滑坡灾害的高敏感性区域,能够有效地将生态源地进行连接;生态廊道在蓟州区的空间分布存在显著的差异,主要分布在蓟州区的北部山区,生态廊道的密度较高,在蓟州区的中部和南部地区,生态廊道的分布非常稀疏。研究成果将为天津市蓟州区生态网络的优化、生态安全格局的构建提供科学依据。     

Time course of the quantitative changes in the autophagic-lysosomal and secretory granule compartments of murine liver cells under the influence of vinblastine

The dynamics of the transient expansion of the autophagic-lysosomal (ALC) and secretory granule (SGC) compartments in mouse liver cells were monitored by electron microscopic morphometry after a single injection of 10 mg/kg b.w. vinblastine sulfate (VBL). Initially (first phase) the cytoplasmic volume fractions of the total ALC and its subcompartments, as well as of the SGC increased by an order of magnitude and peaked at the second h. In the second phase, all the aforementioned compartments regressed gradually, approaching their normal size between 12 and 36 h after VBL injection. Analysis of the dynamic changes in fractional volumes of subcompartments of the ALC showed that early autophagic vacuoles (AV1) were the first to enlarge. Advanced AVs (AV2) reacted 30 min later and a further 30 min time lag was required before late autolysosomes, appearing as dense bodies (DB), started to expand. We regard these data as kinetic proof that the bodies of the later reacting subcompartments developed from the earlier reacting ones. The time lag between the expansion of AV1 and AV2 subcompartments may be explained by a period of retardation of conversion of nascent autophagosomes (AV1) to autolysosomes (AV2) which is known to occur normally by fusion of AV1 with enzyme-carrying lysosomes. However, transformation of AV1 to AV2 and later to DB resumed after the respective time lags. Moreover, our quantitative data lend support to the view that segregation of cytoplasmic portions into newly-formed autophagosomes was stimulated by VBL, at least in the first 2 h of treatment. The expansion of ALC accelerated during this period and led to an obvious overload of the lysosomal apparatus.(ABSTRACT TRUNCATED AT 250 WORDS)     

基于生态安全格局的山水林田湖草生态保护与修复

山水林田湖草生命共同体理论认为：生态要素之间存在普遍联系。在生态安全格局构建中,也应着重维护生态过程的完整性与连通性。以宁波市下辖6个城区为研究区,基于山水林田湖草生命共同体理论构建生态安全格局,以景观连通性评价与栖息地质量评价为基础提取生态源地,确定生态保育区。选取地形、地类因子分别作不同距离的缓冲区分析,对由土地利用类型设定的基础阻力面进行修正,形成综合阻力面。通过最小累积阻力模型识别生态廊道,与生态保育区结合,构建宁波市点-线-面的生态安全格局。研究结果表明：生态源地面积47.24 km²,占研究区总面积的1.30%,生态源地分布较为分散,在东西方向上分布不均衡,生态保育区总面积1191.67 km²,占研究区总面积的32.83%。生态保育区与山地丘陵重合度较高,且植被覆盖度高,生态资源丰富,生态廊道总长度519.32 km。研究区生态廊道呈网状分布,有效的促进物质能量的流动。在阻力面设定中引入邻域分析方法,突出了不同生态要素之间的联系,体现了山水林田湖草生命共同体思想,为该地区生态保护修复提供参考。