中国生态安全屏障体系建设现状、主要问题及对策建议

中国生态安全屏障体系建设是生态文明建设的重要组成部分，在维护国家安全方面具有重大战略意义。研究从生态安全屏障功能特点、建设、监测与评估及规划和实施等方面阐述了我国生态安全屏障体系建设现状；分析了在生态安全屏障建设中，自然生态系统的破坏、社会-生态系统脆弱性、生物多样性保护受到威胁、科技体系支撑不足、公众参与意识薄弱和保护与发展的矛盾等方面面临的主要问题和挑战；进而提出了基于生态安全格局的整体布局方略，指出了开展社会-生态脆弱性调查和评估的重要性，强调了国家公园在生态安全屏障体系建设的引领示范作用。最终，希望通过围绕生态文明建设，引导社会公众深度参与，构建“生态-生产-生活”统筹协调机制，以求积极探索生态安全屏障体系建设高质量、高速和可持续发展道路，迈向新时代生态安全屏障建设新征程。     

LRF and CRF Release in Subcellular Fractions of Bovine Median Eminence

KNOWLEDGE of the subcellular location of pituitary hormone releasing factors in the cellular elements of the neurohypophysis would facilitate the elucidation of the site and mode of synthesis of these factors and the mechanism of their secretion. Our studies of subcellular location of luteinizing hormone and corticotrophin-releasing factors (LRF and CRF) in bovine stalk-median eminence (SME) tissue suggest that both releasing factors are present in fractions which contain structures resembling nerve vesicles and terminals.     

Multi-trichomous cyanobacterial microfossils from the Mesoproterozoic Gaoyuzhuang Formation, China: Paleoecological and taxonomic implications

Populations of the multi-trichomous microbial fossil Eoschizothrix composita n.gen. et sp. are preserved in growth position in silicified stratiform stromatolites of the Gaoyuzhuang Formation, Hebei Province, northern China. The microbial fossils consist predominantly of preserved sheaths, although several specimens retain shriveled remains of trichomes within sheaths. Comparisons with modern morphological counterparts, including shape, growth habit and orientation, degradational sequences, and habitat, support the interpretation of the multi-trichomous microfossils as cyanobacteria, which acted as frame-builders of ancient stromatolites. The distribution and orientation of multi-trichomous microfossils within a synsedimentary context reveal their behavioral responses to sedimentation regime. Horizontally spread, interwoven mats formed during periods of sedimentary stasis. During periods of rapid sediment influx, the filaments assumed an upright orientation, possibly to avoid accumulating particles. This is the first record of fossil stromatolite-building multi-trichomous cyanobacterial which underscores early morphological and functional diversification in cyanobacterial evolution.     

Mitochondrial DNA analyses reveal low genetic diversity in Culex quinquefasciatus from residential areas in Malaysia

The present study explored the intraspecific genetic diversity, dispersal patterns and phylogeographic relationships of Culex quinquefasciatus Say (Diptera: Culicidae) in Malaysia using reference data available in GenBank in order to reveal this species' phylogenetic relationships. A statistical parsimony network of 70 taxa aligned as 624 characters of the cytochrome c oxidase subunit I (COI) gene and 685 characters of the cytochrome c oxidase subunit II (COII) gene revealed three haplotypes (A1–A3) and four haplotypes (B1–B4), respectively. The concatenated sequences of both COI and COII genes with a total of 1309 characters revealed seven haplotypes (AB1–AB7). Analysis using tcs indicated that haplotype AB1 was the common ancestor and the most widespread haplotype in Malaysia. The genetic distance based on concatenated sequences of both COI and COII genes ranged from 0.00076 to 0.00229. Sequence alignment of Cx. quinquefasciatus from Malaysia and other countries revealed four haplotypes (AA1–AA4) by the COI gene and nine haplotypes (BB1–BB9) by the COII gene. Phylogenetic analyses demonstrated that Malaysian Cx. quinquefasciatus share the same genetic lineage as East African and Asian Cx. quinquefasciatus. This study has inferred the genetic lineages, dispersal patterns and hypothetical ancestral genotypes of Cx. quinquefasciatus.     

Effects of Desiccation on some Activated Oxygen Processing Enzymes and Anti-Oxidants in Mosses

The possibility that desiccation tolerance in mosses may bedependent on an ability to process species of activated oxygenwas investigated using the tolerant sand-dune moss Tortula ruraliformis(Besch.) Grout and the sensitive minerotrophic flush speciesDicranella palustris (Dicks.) ex. E. F. Warb (D. squarrosa (Starke)Schp.). Mosses were desiccated in low and high irradiance andresponses of these plants compared to those of dark-desiccatedand hydrated control plants. Both desiccated and undesiccatedplants of T. ruraliformis had a higher superoxide dismutase(SOD) activity than D. palustris, but had similar, or loweractivities of the chloroplastic H₂O₂-processing enzymes peroxidaseand ascorbate peroxidase. In T. ruraliformis, desiccation inboth light and dark led to a significant increase in SOD activity,but did not consistently stimulate the activities of peroxidaseand ascorbate peroxidase. In D. palustris, desiccation in combinationwith irradiance led to a decrease in peroxidase activity, buthad little affect on the activities of other activated oxygen-processingenzymes. Catalase, an extra-chloroplastic enzyme, was up to7-fold more active in hydrated T. ruraliformis than in D. palustris,but desiccation resulted in significant decreases in the activityof this enzyme in both species. Regardless of irradiance level,there was a depletion of the anti-oxidant ascorbic acid in bothspecies when desiccated. Only in T. ruraliformis was there asynthesis of     

Mating effects on the feeding and locomotion of the German cockroach, Blattella germanica

Abstract. Feeding cycles and daily locomotory patterns of the German cockroach, Blattella germanica L. (Dictyoptera: Blattellidae), were correlated with the ovarian development cycle. To meet the nutrient requirement for ovarian development, females increased feeding before forming oothecae. Locomotory activity also increased when females became sexually receptive. All these activities reached a peak just before the formation of oothecae. Ovarian development ceased and locomotion and food consumption decreased during pregnancy. Both mated and virgin females showed similar reproductive cycles, but those of mated females were more precisely timed (intervals between successive oothecae, and pregnancy duration, were 5 ± 0.6 and 17 ± 0.6 days, respectively). However, the intervals between successive oothecae of virgin females were longer and less synchronized. During this longer interval, feeding took place immediately following the discharge of the ootheca, but locomotory activity increased 5 days later when females became sexually receptive. Mated females increased locomotory activities 1 or 2 days before the end of pregnancy, presumably searching for deposition sites for oothecae. Female adults were found to exhibit a daily nocturnal locomotory pattern. However, under the physiological demands of reproduction, the pattern could be changed, for example by increasing activity during photophase when females were sexually receptive. The physiological effects of reproduction override the control of the daily locomotory pattern by its diel clock.