鹅观草属一些种种子胚乳细胞的特征及其分类学意义的探讨

解剖观察了鹅观草属18个种的胚乳细胞, 发现这类细胞在鹅观草属各类群间的发育是不同步的, 其中胚乳细胞的大小、形状、数量以及反映丰厚程度的长宽比不仅具有类群鉴分的价值, 而且还可作为推证类群演化关系的旁证。分析结果表明, 胚乳细胞体积的增大、数量的增多、细胞的变圆、长宽比值的减少皆与类群的进化趋势相顺应。据此, 进一步阐述了鹅观草属组、系、种的系统发育关系。

三自由度全方位移动机器人样机及其控制系统体系结构

本文比较全面地介绍我们研制出的三自由度全方位移动机器人样机系统,包括本体结构、驱动方式、运动学模型、网络通讯、控制及传感系统等方面.该样机系统对于移动机器人规划、避碰、遥操作、鲁棒自适应控制等方法,是一个良好的具有开放性的实验平台及教学机器人;同时,也可以作为产品直接用于导购、导医、迎宾、及科普等领域.另外,多台移动机器人可以方便地构成网络化分布式系统,从而组成支持多智能体系统规划、调度、监控、人一机合作等方面研究的开放式多机器人系统平台.

Public service employment and the public-private wage differential in British regions

Thomas, Dennis, Henley, Andrew, 'Public service employment and the public-private wage differential in British regions', Regional Studies (2001) 35(3) pp.229-240 RAE2008

Towards a regional understanding of Irish traditional music

The geography of Irish traditional music is a complex, popular and largely unexplored element of the narrative of the tradition. Geographical concepts such as the region are recurrent in the discourse of Irish traditional music but regions and their processes are, for the most part, blurred or misunderstood. This thesis explores the geographical approach to the study of Irish traditional music focusing on the concept of the region and, in particular, the role of memory in the construction and diffusion of regional identities. This is a tripartite study considering people, place and music. Each of these elements impacts on our experience of the other. All societies have created music. Music is often associated with or derived from places. Some places construct or reinforce their identity through the music and musicians through which they are associated. The thesis challenges conventional discourse on regional styles that construct an imagined pattern of regions based on subtle musical differences that may, though are not always, shared by people in that region and focuses on the social networks through which the music is disseminated. The thesis also challenges the abandonment of regional styles and the concept of regions in understanding the complex geographies of Irish traditional music (Morton, 2001). It seeks to find a middle ground between discourse analysis, musical analysis, the experience of music and place, and the representation of music and place. The dissertation is divided into three parts. Part one considers the development of music geography, noting and critiquing the abandonment of useful paradigms in both geography and ethnomusicology in search of new ways of understanding. Of particular interest is the concept of the region but it also considers the study of landscape and the humanist approach in cultural geography. The second part focuses on the discourse and study of regions in Irish traditional music and the various agents and processes that shape the concept of the region in Irish traditional music. The final part presents a case study of the Sliabh Luachra region combining and applying the various perspectives and paradigms drawn from geographical, ethnomusicological and anthropological sources. It attempts to generate an understanding of Sliabh Luachra as a region in the Irish traditional music narrative that is based on a combination of musical, socio-cultural and locational/environmental factors.

El papel como material didáctico en la construcción de la geometría plana

La geometría en el currículo de secundaria se introduce con la intención de proporcionar al alumno una mayor capacidad de comprensión de la organización espacial del mundo que nos rodea, exigiendo para ello un aprendizaje sistematizado. Con este propósito, el ``Grupo PI' trabaja en el desarrollo de actividades para el aula utilizando un material económico y de fácil adquisición como es el papel. El objetivo es proporcionar al profesor un material eficaz para el trabajo en el aula y aproximar a los alumnos a la Geometría Plana a través de una serie de tareas estructuradas que logran una mayor significatividad del proceso de aprendizaje. Se emplearán axiomas del origami para crear secuencias que permitan la construcción de representaciones significativas en los procesos de aprendizaje. Por último, intentaremos mostrar a los profesores la utilidad del papel como material didáctico en la construcción de conocimiento geométrico.

Engineering emergence for cluster configuration

Distributed applications are being deployed on ever-increasing scale and with ever-increasing functionality. Due to the accompanying increase in behavioural complexity, self-management abilities, such as self-healing, have become core requirements. A key challenge is the smooth embedding of such functionality into our systems. Natural distributed systems such as ant colonies have evolved highly efficient behaviour. These emergent systems achieve high scalability through the use of low complexity communication strategies and are highly robust through large-scale replication of simple, anonymous entities. Ways to engineer this fundamentally non-deterministic behaviour for use in distributed applications are being explored. An emergent, dynamic, cluster management scheme, which forms part of a hierarchical resource management architecture, is presented. Natural biological systems, which embed self-healing behaviour at several levels, have influenced the architecture. The resulting system is a simple, lightweight and highly robust platform on which cluster-based autonomic applications can be deployed.

Effects Of Low Metal Levels On A Clonal Hydroid

We frequently require sensitive bioassay techniques with which to study the effects of marine contaminants at environmentally realistic concentrations. Unfortunately, it is difficult to achieve sensitivity and precision in an organism amenable to indefinite periods of laboratory culture. Results from different laboratories are often extremely variable: LC50 values for the same substance, using the same organism, may differ by two or even three orders of magnitude (Wilson, Cowell & Beynon, 1975). Moreover, some of the most sensitive bioassay organisms require nutrient media, which may alter the availability and toxicity of metals by complexing them (Jones, 1964; Kamp-Nielsen, 1971; Hannan & Patouillet, 1972) and often contain metal impurities at significant levels (Albert, 1968; Steeman Nielsen & Wium Anderson, 1970). The object of the work reported here has been to develop a technique by which these problems might be minimized or avoided. Hydroids were chosen as bioassay organisms for a variety of reasons. They are tolerant but sensitive to small variations in their chemical environment. Techniques for growing hydroids are simple and they can be cultured under conditions of near optimal temperature, salinity and food supply, thus minimizing the errors frequent in bioassay work arising from variations in the history of the test organisms, their size, sex or physiological state. An important source of variability in all work with organisms is that inherent in the genetic material, but with hydroids this can be avoided by the use of a single clone.

The Atlantic Meridional Transect (AMT) data management experience

As the UK's national marine data centre, a key responsibility of the British Oceanographic Data Centre (BODC) is to provide data management support for the scientific activities of complex multi-disciplinary long-term research programmes. Since the initial cruise in 1995, the NERC funded Atlantic Meridional Transect (AMT) project has undertaken 18 north–south transects of the Atlantic Ocean. As the project has evolved there has been a steady growth in the number of participants, the volume of data, its complexity and the demand for data. BODC became involved in AMT in 2002 at the beginning of phase II of this programme and since then has provided continuous support to the AMT and the wider scientific community through the rescue, quality control, processing and access to the data. The data management is carried out by a team of specialists using a sophisticated infrastructure and hardware to manage, integrate and serve physical, biological and chemical data. Here, we discuss the approach adopted, techniques applied and some guiding principles for management of large multi-disciplinary programmes.

Phytogeographic characterization of Gran Canaria Island (Canary Islands-Spain)

Studies on the flora and fauna of the Canary Islands show that this Archipelago is one of the planet’s diversity hot spots. However, an analysis of the differences in the phytogeographic characteristics of each of the islands that make up this Archipelago is lacking. This article focuses on the phytogeographic characterization of the island of Gran Canaria. This island exhibits geological and climatic characteristics resulting in a rich vascular flora, including endemic species and genera that are significantly different from the other islands of the Archipelago. These differences are verified through statistical analysis of the existing similarity between the floras of the members of the Canary Islands. This study also analyses the subdivision of Gran Canaria Island, indicating that there are three well-differentiated areas on the island itself. Finally, this study argues that these areas, themselves, should be considered biogeographic sectors.