目标物体尺寸的大小对小鼠空间深度感知的影响

探索了小鼠在排除透视、遮挡等空间深度的线索下,是否是依靠视觉目标的尺寸大小来感知空间深度.小鼠放置于可以调节高度的高台上,高台位于仅底面有光线照明、四周黑暗的实验箱内.将由格子构成底部面板的尺寸设计为小鼠估计高度距离的唯一线索,设置了3个空间尺度的底板,分别按2/3的比例缩小,并设置7个高度.在同一高度下每测试一轮即对底板的尺寸进行随机变换.记录小鼠跳落前在高台上停留的时间,研究小鼠对高度的判断是否受到底板尺寸的影响.结果表明所有大小线索条件下小鼠在高台上停留的时间随高度的增加而延长.在20～30cm的高度范围,小鼠不以大小为线索的信息来判断深度,可能主要以双眼视差产生的深度信息来判断高度.而在小于20cm和大于30cm的高度范围,特别是在更高的距离上如50cm、60cm和70cm,小鼠以目标大小信息为线索来对深度进行判断,以弥补在这些条件下双眼深度信息的不足.在理论上说这是由于小鼠只有三分之一的(中央)视野为双眼视野区.实验的行为范式可以应用到以转基因鼠为模式生物的实验中,以研究此类行为与基因之间的关系.     

New technique for studying reaction forces during primate behaviors on vertical substrates

Recording reaction forces from primates during behaviors on vertical substrates, such as leaping, climbing, or biting trees, typically requires the design and construction of customized recording devices or mounting commercially available force platforms in a vertical position. The technical difficulties imposed by either option have hindered in vivo research on the kinetics of primate behaviors on vertical substrates. We describe a simple, inexpensive apparatus for recording forces from primate behaviors on vertical substrates. The apparatus includes an instrumented beam fastened directly to a horizontal force platform and a surrounding vertical substrate that does not contact the instrumented beam or platform. The contact piece at the end of the instrumented beam is positioned flush with the noninstrumented vertical substrate, and reaction forces elicited on this instrumented section are directed to the force platform. Because most of the vertical substrate is not instrumented, we can isolate and record forces from a single limb or jaw during a behavior. Biewener and Full ([1992] Biomechanics Structures and Positions: A Practical Approach; New York: Oxford University press, p. 45-73) gave seven criteria to consider when designing a customized force-recording device. Where appropriate, we tested if our apparatus met their criteria. The apparatus accurately records forces in three orthogonal directions, has low cross-talk, maintains a high frequency response, exhibits a linear response up to at least 200 Newtons, and displays a uniform response to a given force across the instrumented contact piece. Our design does not easily facilitate the identification of the point of force application. Therefore, joint moments cannot be easily calculated. This limitation, however, does not affect the apparatus's ability to accurately record the magnitude and direction of a force (as shown by other tests). We developed this apparatus to measure jaw forces during tree gouging in common marmosets (Callithrix jacchus), but the general design can be readily modified to study a variety of primate behaviors on vertical substrates.     

A micrite-dominated norian carbonate platform from Northern Calabria (Southern Italy)

Summary  This paper is focused on the facies associations of an Early-Middle Norian stratigraphic succession cropping outin the Northern Calabria (Buonvicino, Cosenza). These carbonate deposits, pertaining to the Verbicaro Unit, represent a dolomitized platform characterized by a clear dominance of automicrites over skeletal metazoans. On the basis of the chronostatigraphic data and sedimentary evolution, two stratigraphic units have been distinguished: the Lower Unit (object of the present paper) and the Upper Unit. The Lower Unit consists of an Early-Middle Norian high-relief prograding carbonate platform. The Upper Unit is represented by Middle p.p.-Upper Norian basinal deposits. Three main facies associations, indicative of different depositional settings, have been identified. The inner platform facies association is characterized by automicrite (cauliflower-columnar subordinate planar stromatolites) associated with detrital carbonates (intraclastic breccia, bioclastic grainstone and packstone). Apeculiar facies is represented by megalodontid-bearing beds. Mud-cracked horizons and low-developed teepees occur quite frequently. The margin facies association is dominated by automicrite (planar to low relief stromatolites associated with thrombolitic fenestral boundstone) and detrital carbonates with subaerial exposure features. The slope facies association includes detrital carbonates (breccia/megabreccia) associated with serpulid/sphinctozoan bioconstructions and automicrite (planar stromatolites/thrombolitic boundstone). The whole carbonate body is completely dolomitized; nevertheless the morphology and microarchitecture of carbonate components (cements, grains and automicrite) is still clearly recognizable. The dolomite Mg content ranges from 40 to 48 mole%, sometimes reaching the stoichiometric value. Cements, primary and late, represent a minor component of the rock volume; they occur more frequently on the margin and upper slope setting. Quantitative tacies analyses lead to the following conclusions:

“微生物学”一流课程教学改革与实践

“微生物学”课程是酿酒工程、生物工程、生物技术等专业的必修课程,也是一门重要的专业核心课程。基于培养具有科学探究能力的创新型人才的教学目标,我们教学团队深入改革“微生物学”课程,建设一流本科课程。通过贯彻“以学生为中心”和“科研反哺教学”的教学理念,深入挖掘课程育人价值,开展课程思政建设工作,建设慕课(massive open online course, MOOC)平台“微生物学”课程线上教学全套资源,构建“夯实基础-解构问题分析训练-研讨课”的教学模式,改进学生学习模式,改革学习过程评价体系,以及指导学生参加科创竞赛等教学改革实践,全面提高学生的科学探究能力,为社会储备具有科学探究能力的创新型人才,为工科院校建设一流课程提供借鉴。     

Evolution of Hominid Femur and Tibia: A morphometric approach to the evolutionary research in anthropology

Some theoretical and methodological morphometrical approaches in evolutionary anthropology and paleoanthropology are reviewed in this study. It is shown which are the contemporary possibilities of sophisticated biometrical and biostatistical methods and the role of the morphometrical approach. A new approach, experimental morphometrics, is presented, reflecting recent trends in evolutionary morphology as well as sophisticated biostatistical methods. The approach emphasizes the complex inter-related approach to the data processing and a double nature of morphometric data, i.e. biological and biostatistical one. The practical use of experimental morphometry is given for the two examples of analyses of the evolution of the hominoid and hominid femur and tibia. The hypothesis on a two stage restructuring of morphology of the hominid femur and tibia is supported by experimental results. Two different steps during this restructuring could be recognized: 1) Structural remodelling typical for the origin of hominids and australopithecine evolution, and 2) proportional remodelling of lower limb long bones which is connected with the Australopithecus/Homo transition (i.e. mainly Homo habilis stage). The results confirm the increasing trend of bipedal adaptations on the early hominid lower limb skeleton. Analysis of microevolutionary trends on the Homo sapiens femur and tibia indicates at least three different morphological patterns, Paleolithic, Neolithic and Recent, with numerous specific features in morphology and proportions. Neanderthal morphology is very derived. Upper Paleolithic/Mesolithic/Neolithic transition has a key character for the understanding of post-Paleolithic morphology. A very high sexual dimorphism of the femur and tibia has been demonstrated for Upper Paleolithic and Neolithic populations. Presented at the Foundation of Different Approaches to the Study of Human Evolution edited by B. Sigmon & V.V. Leonovicova-Liblice, September 1–3, 1989     

Gene-Expression Omnibus integration and clustering tools in SeqExpress

SeqExpress, a gene-expression analysis suite, has been extended to offer a number of cluster generation, refinement and visualization techniques. The cluster generation methods have been specialized to deal with aspects of the sparseness and extreme values that occur within microarray data. The results of such cluster analysis can then be refined using either: a functional enrichment based procedure, which examines each cluster to see if it possesses an unusually high or low concentration of ontology terms; or by using Expectation-Maximization to find a mixture of model based distributions within the datasets. Visualizations are provided both to explore and compare the results of the cluster generation algorithms. In addition, a tool has been developed which integrates SeqExpress with the Gene-Expression Omnibus repository. The tool provides seamless access to the large number of experimental results in the repository, so that they can be visualized and analysed locally using SeqExpress. AVAILABILITY: SeqExpress is available as a 6 MB download from http://www.seqexpress.com and runs under Windows. A server-based version is available and is required for the GEO integration. SeqExpress is not affiliated with any academic institution, funding body or commercial organization and is free to use by all.     

Silencing long non‐coding RNA MEG3 accelerates tibia fraction healing by regulating the Wnt/β‐catenin signalling pathway

As fracture healing is related to gene expression, fracture healing is prospected to be implicated in long non‐coding RNAs (lncRNAs). This study focuses on the effects of epigenetic silencing of long non‐coding RNA maternally expressed gene 3 (lncRNA MEG3) on fracture healing by regulating the Wnt/β‐catenin signalling pathway. Genes expressed in fracture were screened using bioinformatics and the subcellular location of MEG3 was determined using FISH. Next, we successfully established tibia fracture (TF) models of C57BL/6J and Col2a1‐ICAT mice and the effect of silencing lncRNA MEG3 on fracture healing was detected after TF mice were treated with phosphate buffer saline (PBS), MEG3 siRNA and scramble siRNA. X‐ray imaging, Safranin‐O/fast green and haematoxylin‐eosin (HE) staining and histomorphometrical and biomechanical analysis were adopted to observe and to detect the fracture healing conditions. Additionally, the positive expression of collagen II and osteocalcin was examined using immunohistochemistry. At last, in the in vitro experiment, the relationship of MEG3 and the Wnt/β‐catenin signalling pathway in fraction healing was investigated. MEG3 was located in the cell nucleus. In addition, it was found that MEG3 and the Wnt/β‐catenin signalling pathway were associated with fraction healing. Moreover, silencing MEG3 was proved to elevate callus area and maximum bending load and to furthermore enhance the recanalization of bone marrow cavity. Finally, MEG3 knockdown elevated levels of Col10a1, Runx2, Osterix, Osteocalcin, Wnt10b and β‐catenin/β‐catenin whereas it reduced p‐GSK‐3β/GSK‐3β levels. Taken together, our data supported that epigenetic silencing of lncRNA MEG3 could promote the tibia fracture healing by activating the Wnt/β‐catenin signalling pathway.     

基于景感生态学的生态环境物联网框架构建

更高的城市化率造成新的城市生态环境问题和变化趋势，新理论与新技术也为生态环境监测与管理提供了新方法。景感生态学是以可持续发展为目标，基于生态学的基本原理，从自然要素、物理感知、心理感知、社会经济、过程与风险等相关方面，研究土地利用规划、建设与管理的科学。基于景感生态学理论，开展生态环境物联网的监测网络设计与监测平台构建。首先，从自然要素中的光、热、水、土壤、综合气象等，以及物理感知的视觉、嗅觉、听觉、触觉等作为监测要素并进行特征分析；其次，结合多目标约束和聚类分析约束条件，提出非规则网格最优法进行生态环境监测网络的布设。再其次，重点探讨了联合地面固定监测站、无人船与无人机构建的"陆海空一体化"的生态环境数据采集与监测；其中，在地面构建综合气象与土壤传感器，可监测自然要素的光照、热量、雨量、气压，以及物理感知要素的风速、风向温度、湿度及噪声等；在海洋中，基于无人船搭载的水环境与水质传感器，可监测水体温度、水浑浊度与水污染状况，以及水体总磷与水体质量等；在空中，基于无人机搭载的气体监测仪、多/高光谱传感器与数码相机，可获取不同区域与不同高度的CO₂、SO₂、PM_1.5、PM_2.5、NO、O₃等大气环境状况及粒子溶度与污染物扩散状况。最后，从全方位、多要素的数据获取、有线网络与无线网络相结合的数据传输、数据分类处理、数据智能控制，以及包含实时监测、预报预警、综合分析和平台管理的远程监控平台等五个模块来构建物联网监测平台。构建的生态环境物联网框架可实现生态环境全方位、全天候、多维度的远程实时监测与智能预警预报，为提升城市生态环境监测与管理提供支撑平台，增强了生态环境安全，满足人民日益增长的优美生态环境需要，提高了城市生态环境动态监测和智能管理的效益。     

计算机辅助药物筛选平台及应用

先导化合物发现是创新药物研发的最重要环节之一。针对目前海量功能不明确的小分子化合物,本文构建了一个用来实现快速发现先导化合物,有效降低药物研发成本的计算机辅助药物筛选平台。该平台采用分布式架构思想,集成了Auto Dock Vina和多个小分子库,具有数据安全、计算与存储的负载均衡以及实时监控的特点。应用平台进行先导化合物筛选,在较短时间发现了有针对性的活性小分子化合物,命中率高,大大缩短先导化合物发现周期。该平台具有很好的实用性和良好的扩展性。