Integrating forage,wildlife, water,and fish projections with timber projections at the regional level: A case study in southern United States

The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States. The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion to planted pine.     

Polarization-Sensitive Interneurons in the Optic Lobe of the Desert Ant Cataglyphis bicolor

 Desert ants, Cataglyphis bicolor (Hymenoptera), navigate by using compass information provided by skylight polarization. In this study, electrophysiological recordings were made from polarization-sensitive interneurons (POL-neurons) in the optic lobe of Cataglyphis. The POL-neurons exhibit a characteristic polarization opponency. They receive monochromatic input from the UV receptors of the specialized dorsal rim area of the compound eye. Both polarization opponency and monochromacy are features also found in the POL-neurons of crickets (Orthoptera). Received: 29 September 1999 / Accepted in revised form: 13 December 1999     

恢复力与可持续发展:在瞬息万变的世界中增强适应能力

由于在以往的自然资源政策上逐渐暴露出了两个带根本性的错误,人们开始意识到在环境管理理论和实践方面需要进行一场全球性的重大改革.第一个错误是毫无保留地假定生态系统对人类利用所作出的反应是呈线性关系、是可以预测和控制的.第二个错误是认定人类社会与天然系统可以分别对待,不必联系在一起进行考虑.然而,从世界各地收集到的证据表明,天然系统和人类社会系统是以非线性方式运行的、在其动态运行过程中均有其显著的极限,而且,人类社会与生态系统表现为一种紧密相联的、复杂的且不断演变的综合系统.本文是代表瑞典政府环境咨询委员会编写的一份报告的摘要,这份报告是作为向2002年8月26日～9月4日在南非约翰内斯堡召开的可持续发展世界首脑会议献礼的论文而撰写的.从概念上说,恢复力是一种能缓冲变化所带来的影响、学习知识和求得发展的能力,我们将它作为在一个纷纭复杂、快速变化的世界中,是否真正懂得如何维护和提高适应能力的一种参照标准来使用.在社会、生态综合系统中,有两种有用的工具可用来提高恢复力,一种是结构严谨的工作方案,另一种是积极的适应力管理.这两种工具都需要而且有助于形成这样一种社会环境:具有灵活开放的组织机构和多层次的监管体制,允许学习适应力方面的知识和提高适应力但又不妨碍对未来的发展作出选择.     

参与式管理解决冲突:遥感和GIS用作瑞典北部驯鹿业土地利用需求信息交流的工具

在解决复杂的土地管理问题时,对短缺或者有争执的资源进行地理评估有助于不同利益相关者之间沟通认识和增进理解.本文中,我们说明如何使用遥感和GIS收集和汇总瑞典北部驯鹿放牧者和其他土地使用者(林业、采矿业、旅游业等等)的土地使用活动及使用模式的信息.该项目主要基于最终的土地使用者,即驯鹿放牧者们所做的工作,体现了面向土地使用者的新的努力.发展驯鹿业的土地利用规划的基础有以下几个方面:收集并数字化传统的驯鹿栖息地生态学和景观信息将这些信息与来自野外调查及基于人造卫星观测的植被分类结果整合;绘制其他土地使用者的活动情况图.最终的土地利用规划提供的信息有利于驯鹿放牧者与其他利益相关者之间的磋商,并有助于驯鹿管理实施.该项目可作为一种大众参与和计划编制的模式,从而使本土信息和先进的遥感技术融入一个交互式的过程中.     

A chemical view of the most ancient metazoa--biomarker chemotaxonomy of hexactinellid sponges

Hexactinellid sponges are often considered to be the most ancient metazoans. Lipid biomarkers from 23 species were studied for information on their phylogenetic properties, particularly their disputed relation to the two other sponge classes (Demospongiae, Calcarea). The most prominent lipid compounds in the Hexactinellida comprise C28 to C32 polyenoic fatty acids. Their structures parallel the unique patterns found in demosponge membrane fatty acids ('demospongic acids') and strongly support a close phylogenetic association of the Demospongiae and the Hexactinellida. Both taxa also show unusual mid-chain methylated fatty acids (C15-C25) and irregular C25- and C40-isoprenoid hydrocarbons, tracers for specific eubacteria and Archaea, respectively. These biomarkers indicate a similar, highly conservative symbiont community, although some shift in the abundance of the associated microbiota was observed. The lack of these features in calcareous sponges further contradicts the still common view that Calcarea and Demospongiae are more closely related to each other than either is to the Hexactinellida.     

Genetic amniocentesis in multiple gestations

Thirty-one genetic amniocenteses involving multiple gestations were performed in the genetics unit between 1976 and 1982. Three sets of triplets were included. Precise locations of the sacs were determined using real-time ultrasonography and successful sampling of all sacs was accomplished. Spontaneous abortions occurred in two normal twins and one normal triplet gestation. Two therapeutic abortions were performed for fetal abnormalities. Two cases of discordance for trisomy 21 (one twin and one triplet) were allowed to continue; the twin case terminated at 25 weeks' gestation with neonatal deaths and the triplets are alive and well.     

The time of appearance and disappearance of fetal DNA from the maternal circulation

A single copy Y-chromosome DNA sequence was amplified using the polymerase chain reaction (PCR) from the peripheral blood of 30 women who had achieved a pregnancy through an in vitro fertilization (IVF) programme. The time of conception was known precisely and was confirmed by serial ultrasound scans. Conceptions were dated as the number of weeks after fertilization plus 2, to give a time equivalent to the obstetric menstrual dating of the pregnancy (LMP). Y-chromosome-specific DNA was detected in all pregnancies with a male fetus (18/30). The earliest detection was at 4 weeks and 5 days, and the latest at 7 weeks and 1 day. Y-chromosome-specific sequences were no longer detected in any of the male pregnancies 8 weeks after delivery. No Y-chromosome sequences were detected in any of the pregnancies where only female babies were delivered. This demonstrates that fetal DNA appears in the maternal circulation early in the first trimester, that it can be identified in all pregnancies tested by 7 weeks, that it continues to be present throughout pregnancy, and that it has been cleared from the maternal circulation 2 months after parturition. Early non-invasive prenatal diagnosis for aneuploidies and inherited disorders will be possible in all pregnancies if fetal cells can be isolated free from maternal contamination (or identified accurately in the presence of maternal cells) without problems of contamination from previous pregnancies.