乌鲁木齐市区越冬期长耳鸮的食性分析

2009～2011年间,利用食团分析法对乌鲁木齐市越冬长耳鸮(Asio otus)的食性进行分析。3年累计收集长耳鸮食团683份,辨认出1 132只猎物。分析结果表明,长耳鸮在冬季共捕食小型哺乳类6种,鸟类2种。小家鼠(Mus musculus)是最常见的食物,占总捕食量的53.45%。小型哺乳类是长耳鸮的主要食物,它在食物组成中出现的总频率为88.16%,以生物量计,小型哺乳类占食物构成的95.13%。长耳鸮的食物组成年度间差异显著,与当地猎物资源多样性和可获得性密切相关,表明长耳鸮可能采用机会主义者的捕食策略。     

长耳鸮食性的初步分析

1982—1984年在曲阜孔庙共采集地区留鸟长耳鸮食物团375个,对其中353件进行了食性分析,结果表明,在3—5月,食物团中鼠类占94.44％;而在冬季,鼠类占99.4％;在春季及冬季,极少捕食有益鸟类等。 据胡鸿兴对武昌珞珈山长耳鸮的越冬习性和食性分析,武昌珞珈山长耳鸮有季节迁徙(11月中、下旬至翌年3月下旬)习性,食有害动物占89.3％;有益动物占10.6％。关于北方的长耳鸮生态,尚未见报道。我们从1982年3月至     

北京市区越冬长耳的食性分析

2004年11月至2005年4月,采用食团分析法对北京市区内天坛生物制药厂和国子监公园内栖息越冬的长耳鸮(Asiootus)的食物组成进行了分析。发现天坛生物制药厂长耳鸮的食物中啮齿类占41.0%,翼手类占29.5%,鸟类占29.3%,食虫类占0.2%;国子监长耳鸮的食物组成中翼手类占53.8%,啮齿类占21.5%,鸟类占24.7%。翼手目主要种类有山蝠(Nyctalus noctula)和普通伏翼(Pipistrellus abramus)等。长耳鸮三类主要食物所占比例的逐月变化显示,翼手类所占百分比不断上升,啮齿类所占比例先上升而到翌年1、2月开始下降,鸟类所占百分比一直在下降。蝙蝠大量出现于温带冬季鸮类的食物中属首次发现。     

甘肃民勤治沙站纵纹腹小鸮食性的季节变化

分析民勤治沙站纵纹腹小鸮(Athene noctua)食团405块,共鉴定猎物562只。以个体计,民勤小鸮主要取食昆虫,占64.23%;其次为小型哺乳类,占32.38%;也取食少量爬行类(1.96%)和雀形目鸟类(1.42%)。生物量贡献则以小型哺乳类为主,占93.34%。猎物种类组成存在显著的季节变异:取食小型哺乳类的频率存在显著季节差异,冬季最高94.59%,夏季最低17.75%,食物生物量贡献四季均在90%以上,季节变异不显著;昆虫成分出现在除冬季外的其他季节,且取食频率均在65%以上,季节差异显著;爬行类仅出现于夏季食谱中,仅秋季没有发现鸟类成分。分析秋、冬、春三季哺乳类猎物胫骨的量度发现,小鸮取食哺乳类的胫骨长度平均为16.22mm±4.72mm(n=112),主要取食Ⅰ(10.01mm-15.00mm)和Ⅱ(15.01mm-20.00mm)等级的猎物(分别58.04%和25.00%)。取食猎物的胫骨长度组成存在季节差异,平均长度以春季最大。民勤地区小鸮一年的食物生态位宽度为2.32,季节间存在变异,以冬季最高为2.99,夏季最低为1.64。一年的食物多样性为1.96,季节间存在变异,冬季最高为2.00。食物种类以夏季最多,秋季最少。     

阿尔金山国家级自然保护区纵纹腹小鸮食性的季节变化

2012—2013年间,利用食团分析法对阿尔金山国家级自然保护区纵纹腹小鸮Athene noctua的食性进行分析。共分析343个纵纹腹小鸮食团,鉴定出353个猎物。以个体计,当地纵纹腹小鸮主要取食小型哺乳动物,占95.18%,其次为鸟类,占3.97%,也取食少量昆虫(0.85%)。生物量贡献则以小型哺乳动物为主,占99.35%。纵纹腹小鸮在夏季和冬季就可鉴定的取食动物种类比例组成而言,差异具有高度统计学意义(χ2=52.27,df=4,P0.01)。冬、夏两季纵纹腹小鸮取食哺乳动物的平均胫骨长度差异具有高度统计学意义(P0.01)。全年来看,纵纹腹小鸮取食哺乳动物的胫骨长度平均为19.45 mm±5.84 mm(n=194),主要取食Ⅱ级(10.01 mm~20.00 mm)和Ⅲ级(20.01 mm~30.00 mm)的猎物(分别为46.39%和48.45%)。保护区纵纹腹小鸮的食物生态位宽度以夏季最高(2.583),冬季最低(0.949)。研究结果表明纵纹腹小鸮是机会主义捕食者,根据生境中食物的可获得性改变食性。     

长耳鸮越冬栖息地环境因子分析

通过对河北省保定市直隶总督署博物馆越冬长耳鸮种群数量和习性的长期观察及其越冬栖息地环境因子的分析,得出如下结论:总督署博物馆虽地处保定闹市中心,但由于其建筑格局等因素影响,院内噪声值、大气中的二氧化硫、氮氧化物、总悬浮物微粒的含量明显低于院外;博物馆院内种植有多株高大的常绿乔木,为长耳鸮提供了良好的栖息、隐蔽场所;越冬长耳鸮种群数量的变动与温度有一定的对应关系;近年来在总督署博物馆大院内越冬栖息的长耳鸮数量有较大波动,且有下降趋势,这与总督署博物馆的改建、游客数量增多、食物短缺及冬季气温升高等因素有关.     

内蒙古赛罕乌拉国家级自然保护区猞猁食物构成初步分析

猞猁(Lynxlynx)是内蒙古赛罕乌拉国家级自然保护区内的顶级捕食者,在维持该地区生态平衡和调节猎物数量上具有重要地位。分析猞猁粪便样品残留物不仅能明确其猎物构成,了解与同域分布其他捕食者的关系,还能为制定物种保护措施和栖息地管理策略提供科学参考。本研究在2006至2008年间利用样线法在该区域收集到35份猞猁粪便样品。通过相对出现频率法对粪样进行食性分析,发现猞猁的主要食物组成以蒙古兔(Lepus tolai,30.85%)和植物(28.72%)较多;年度(χ~2=18.696,P <0.001)和季节性(χ~2=74.695,P <0.001)食物构成均存在显著差异。结果表明,蒙古兔在猞猁的食物组成中占最重要地位;猞猁的食物构成与季节有关,寒冷季节捕食大型猎物,而温暖季节捕食的小型猎物更常见。     

马铁菊头蝠捕食活动与猎物资源的关系

捕食者与猎物的关系研究对了解物种捕食行为及种群空间格局具有重要意义。采用Avisoft Bioacoustics超声波仪录制马铁菊头蝠自然状态下的声波以确定其捕食活动强度,用灯诱法、扫网法和飞行阻隔法相结合采集昆虫,搜集蝙蝠粪便并分析其食物组成。结果表明,马铁菊头蝠在8月份活动最频繁,昆虫丰富度在8月份最丰富,马铁菊头蝠捕食活动与鳞翅目丰富度呈显著正相关。马铁菊头蝠主要以鳞翅目和鞘翅目为食,但食性存在明显的月份变化。卡方检验结果表明,马铁菊头蝠捕食的猎物与环境中可利用的昆虫猎物存在显著差异。在食物资源丰富时,马铁菊头蝠选择性地捕食营养丰富的鞘翅目昆虫。     

储草期增加食物对布氏田鼠越冬存活率的影响北大核心CSCD

布氏田鼠(Lasiopodomys brandtii)是内蒙古典型草原区主要鼠种之一。该鼠种在秋季将食物储存在储草仓内,以此来度过植被贫瘠的冬季。为探究储草期增加食物对布氏田鼠越冬存活率的影响,2004年10月,于内蒙古阿巴嘎旗白音图噶苏木的布氏田鼠鼠害草场随机选取两块100 m×200 m的样地,分别设为增食样地和对照样地。增食样地内给每个布氏田鼠洞群补充食物,每天补充500 g小麦,连续补充2 d共计1000 g。对照样地内则不做任何处理。2004年10月,采用标志重捕法调查两块样地内布氏田鼠种群数量,调查显示,增食样地和对照样地内,布氏田鼠数量分别为310只和318只,以该结果作为计算其越冬存活率的基数。2005年5月,返回样地再次进行标志重捕,分别计算两样地布氏田鼠的越冬存活率。卡方检验显示,储草期增加食物能显著提高布氏田鼠越冬存活率。增食样地布氏田鼠越冬存活率为41.3%,显著高于对照样地布氏田鼠越冬存活率(24.2%,P<0.01)。增食样地雌性和雄性布氏田鼠越冬存活率分别为45.4%和37.3%,均显著高于对照样地雌性和雄性布氏田鼠越冬存活率(25.8%和22.6%,P<0.01)。但样地内雌性和雄性越冬存活率均无明显差异(P>0.05)。本研究结果表明,补充食物可大幅度提升布氏田鼠冬季存活率,增加布氏田鼠越冬存活基数,对来年种群增长起重要作用。     

巴基斯坦旁遮普中部仓鸮食性的季节性变化

在巴基斯坦对仓鸮食性的季节变化进行了研究。通过分析连续3年在6个地区搜集的2 360个仓鸮回吐食物团,发现其食物主要是小型哺乳动物(95.6 %)。其中,家(Suncus murinus)有最高的比例,达65.6%(冬季最多78%,夏季最少27%)。就生物量而言,小型哺乳动物占仓鸮食物总生物量的99% 。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

2017年中国植物科学若干领域重要研究进展

2017年中国植物科学继续保持高速发展态势, 重大成果频出, 具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈, 如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中, 有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外, 值得一提的是, 长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果“水稻高产优质性状形成的分子机理及品种设计”荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理, 旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态, 与广大读者共同分享我国科学家所取得的辉煌成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义。综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望。     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义.综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望.     

Changes in aquatic vegetation in Rhine floodplain streams in Alsace in relation to disturbance

Abstract. Changes are described in aquatic vegetation in oligotrophic, groundwater-fed Rhine floodplain streams in Alsace (eastern France), resulting from disturbance. Disturbance factors include changes in nutrients, either permanent ones - effluent from a waste water treatment plant or trout hatcheries - or periodic ones: flooding. Regular inputs of high levels of phosphate and ammonia modified the macrophyte vegetation in these streams. The floristic composition, which was characteristic of oligotrophic waters upstream of the eutrophicated sector, changed to that of a eutrophic situation as originally found downstream. Periodic disturbance by floods which normally occur once a year, irregularly eutrophicates the small streams, causing the development of a mixture of eutrophic and oligotrophic species. Six macrophyte communities are distinguished, indicating different trophic levels. The aquatic vegetation is adapted to the variations of phosphate and ammonia levels. Hence, aquatic macrophytes can be used as bio-indicators of fluctuations in water nutrient levels in relation to the type of disturbance.     

Apoptosis in experimental myocardial infarction in situ and in the perfused heart in vitro

We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.     

Morphine-potentiated platelet aggregation in in vitro and platelet plug formation in in vivo experiments

The detailed mechanisms underlying morphine-signaling pathways in platelets remain obscure. Therefore, we systematically examined the influence of morphine on washed human platelets. In this study, washed human platelet suspensions were used for in vitro studies. Furthermore, platelet thrombus formation induced by irradiation of mesenteric venules with filtered light in mice pretreated with fluorescein sodium was used for an in vivo thrombotic study. Morphine concentration dependently (0.6, 1, and 5 microM) potentiated platelet aggregation and the ATP release reaction stimulated by agonists (i.e., collagen and U46619) in washed human platelets. Yohimbine (0.1 microM), a specific alpha(2)-adrenoceptor antagonist, markedly abolished the potentiation of morphine in platelet aggregation stimulated by agonists. Morphine also potentiated phosphoinositide breakdown and intracellular Ca(2+) mobilization in human platelets stimulated by collagen (1 microg/ml). Moreover, morphine (0.6-5 microM) markedly inhibited prostaglandin E(1) (10 microM)-induced cyclic AMP formation in human platelets, while yohimbine (0.1 microM) significantly reversed the inhibition of cyclic AMP by morphine (0.6 and 1 microM) in this study. The thrombin-evoked increase in pH(i) was markedly potentiated in the presence of morphine (1 and 5 microM). Morphine (2 and 5 mg/g) significantly shortened the time require to induce platelet plug formation in mesenteric venules. We concluded that morphine may exert its potentiation in platelet aggregation by binding to alpha(2)-adrenoceptors in human platelets, with a resulting inhibition of adenylate cyclase, thereby reducing intracellular cyclic AMP formation followed by increased activation of phospholipase C and the Na(+)/H(+) exchanger. This leads to increased intracellular Ca(2+) mobilization, and finally potentiation of platelet aggregation and of the ATP release reaction.