青天葵的人工栽培技术研究

本文报道青天葵的栽培研究结果。采用较大的种苗种植可获得较大的种茎;选用大中种茎,适当密植,在60—70%的荫蔽度条件下产量较高;适当推迟收获期,不但产量高,而且形成的球茎较大,有利于青天蔡的繁殖和生长。     

国家公园类型划分与空间识别——以云南省为例

国家公园是我国推进生态文明建设的重大制度创新,如何科学地对国家公园进行类型划分及空间识别,是国家公园布局和建设中的基础性工作,既有必要性也有紧迫性。本研究以中国国情为基础,参考国际经验,将国家公园划分为荒野导向型、生态优先型、游憩导向型与遗产导向型,构建了一个比较完整的国家公园分类体系。并以自然和人文多样化程度较高的云南为案例,以“双评价”为基础建立了一套指标体系和区划规则,利用人工神经网络建立土地利用演化学习算法,利用融入自适应惯性机制的元胞自动机展开时空模拟,对云南全域进行高分辨率不同类型国家公园的空间辨识,并通过收缩-膨胀原理对识别区域进行比较、修正和优化,进而提出未来云南国家公园布局的综合方案。结果表明: 云南省国家公园主要集中在三江地区与横断山区、滇西以及西南部地区,这3类地区可作为未来国家公园区划与分类保护的重点。本研究所建立的国家公园类型划分和空间识别的一般性可推广的研究范式和工作流程可作为全国应用的参考。     

Utility of field-based artificial streams for assessing effluent effects on riverine ecosystems

Experimentation using field-based artificial streams provides a promising, complimentary approach to biomonitoring assessments because artificial streams provide control over relevant environmental variables and true replication of treatments. We have used large and small artificial stream systems, based in the field, to examine the effect of treated bleached kraft pulp mill effluent (BKME) on the benthos of three large rivers in western Canada. Under natural regimes of temperature, water chemistry, and insolation, these artificial streams provide current velocities and substrata to food chains or food webs that are representative of those in the study river. With these tools we have shown that BKME stimulated mayfly growth in the Thompson River above that which could be accounted for by fertilization of their algal food supply. In contrast, moulting frequency was inhibited at high BKME concentrations. Results from artificial streams also indicate that increased algal biomass and abundances of benthic communities downstream of BKME outfalls were induced by nutrient enrichment from the effluent. BKME treatments did not change diatom species richness in the Fraser River, or diatom species diversity in either the Athabasca or Fraser Rivers. Artificial streams provide a means of understanding the mechanisms of stressor effects over a continuum ranging from single stressor effects on specific taxa to the effects of multiple stressors on communities and ecosystems. Because riverside deployment provides environmental realism within a replicated experimental design, this approach can (i) address questions that cannot be examined using laboratory tests or field observations, (ii) improve our mechanistic understanding of stressor effects on riverine ecosystems, and (iii) can contribute directly to the development, parameterization, and testing of models for predicting ecosystem-level responses.     

Construction and characterization of two rice bacterial artificial chromosome libraries from the parents of a permanent recombinant inbred mapping population

Rice is a leading grain crop and the staple food for over half of the world population. Rice is also an ideal species for genetic and biological studies of cereal crops and other monocotyledonous plants because of its small genome and well developed genetic system. To facilitate rice genome analysis leading to physical mapping, the identification of molecular markers closely linked to economic traits, and map-based cloning, we have constructed two rice bacterial artificial chromosome (BAC) libraries from the parents of a permanent mapping population (Lemont and Teqing) consisting of 400 F9 recombinant inbred lines (RILs). Lemont (japonica) and Teqing (indica) represent the two major genomes of cultivated rice, both are leading commercial varieties and widely used germplasm in rice breeding programs. The Lemont library contains 7296 clones with an average insert size of 150 kb, which represents 2.6 rice haploid genome equivalents. The Teqing library contains 14208 clones with an average insert size of 130 kb, which represents 4.4. rice haploid genome equivalents. Three single-copy DNA probes were used to screen the libraries and at least two overlapping BAC clones were isolated with each probe from each library, ranging from 45 to 260 kb in insert size. Hybridization of BAC clones with chloroplast DNA probes and fluorescent in situ hybridization using BAC DNA as probes demonstrated that both libraries contain very few clones of chloroplast DNA origin and are likely free of chimeric clones. These data indicate that both BAC libraries should be suitable for map-based cloning of rice genes and physical mapping of the rice genome.     

人类口腔小生境微生物的多样性

本文论述了人类口腔中微生物的物种多样性,口腔小生境的复杂性与微生物多样性的关系,以及口腔中微生物变化与人类疾病和健康的关系。     

Theoretical and experimental determination of SAR patterns for spherical tissue models in a rectangular resonant cavity

Specific absorption rates (SARs) were determined theoretically and experimentally for several spherical models of tissue exposed to electrical fields of TE101 mode in a rectangular cavity of 57.3 MHz resonant frequency. The approximate theoretical SAR can be calculated according to the Mie theory by superposition of four plane waves representing the fields excited in the cavity. The theoretical and thermographically determined SAR patterns in spheres with radii of 5, 7.5, and 10 cm and with conductivities of 0.1, 1, and 10 S/m were compared. For a sphere with radius less than 7.5 cm and conductivity less than 1 S/m, the SAR was quite uniform. When conductivity was increased to 10 S/m, the SAR patterns showed higher absorption in the periphery of the largest sphere (10-cm radius). These characteristics are important in evaluating the scaling technique of exposing a model of a human to very-high-frequency fields to obtain power absorption data in humans exposed to high-frequency or very-low-frequency fields.     

The consumption and utilization of the spiral blue-green algae Spirulina platensis in artificial diets by the silkworm, Bombyx mori

The consumption and utilization of various concentrations of the spiral blue-green algae, Spirulina platensis (Nordst.) Geitl., by the fourth-instar larvae of the silkworm, Bombyx mori L., was studied by incorporation into an artificial diet. The silkworms ingested more food on the low algal-powder diets, whereas they digested more efficiently on the high algal levels. The larvae fed on diets containing 30–40% algae had the shortest larval duration compared to those on low algal-powder diets. The freeze-dried powder of S. platensis is well utilized by B. mori larvae when added to artificial diets at levels between 15% and 30%, although the high algal content at 40% was slightly better for the efficiency of conversion of ingested diet into body substance (E.C.I.) and the cocoon production. However, analysis of the protein content in feces indicated an excess of the algal powder at 40%. Measurements of data on the food consumption and utilization in this study proposed that this spiral alga is dietetically utilizable as a protein source for rearing the silkworm in smaller quantities than on a soybean meal.

---

Resúmé La consommation et l'utilisation de différentes concentrations de Spirulina platensis par les chenilles de 4ème stade de Bombyx mori, ont été étudiées par incorporation dans un aliment artificiel. Les vers à soie ont ingéré plus d'aliment avec les régimes à faible concentration en algue, tandis qu'ils ont digéré plus efficacement les régimes à haute concentration d'algue. Les chenilles alimentées sur des régimes contenant 30 à 40% d'algue ont eu un développement larvaire plus bref que celles alimentées sur des régimes à faible concentration. La poudre congelée et séchée de S. platensis incorporée aux taux de 15 à 30% dans le régime artificiel est bien utilisée par les chenilles de B. mori, quoiqu'une teneur de 40% soit légèrement meilleure pour l'efficacité de conversion de l'aliment en matière vivante (E.C.I.) et la production de cocons. Cependant, l'analyse du contenu protéique dans les excréments révélait un excès de poudre d'algue à 40%. L'analyse des données au cours de cette étude, sur la consommation et l'utilisation des aliments, montre que S. platensis est utilisable diét étiquement en plus petite quantité que la farine de soja comme source de protéines pour l'élevage du ver à soie.

     

B-cells of the synovial membrane. II. Differentiation during development of the synovial cavity in the mouse

Summary Study of pre- and postnatal development of the metatarsophalangeal joint of the mouse shows that the synovial cavity (SC) forms before any differentiation of the synovial mesenchyme. The primitive cleft results from degradation of a thin vascular mesenchymal layer in direct contact with the chondrogenic layers. Differentiation of the synovial membrane coincides with clarification of the SC (3rd to 6th day of postnatal life). When dilatation of the SC occurs (6th to 8th day), the two intimal cells types (A- and B-cells) are well identified. The B-cells already show typical features at day 6; their content of typical dense secretory vesicles is comparable to that of the adult B-cells at day 13. The specific secretory function of B-cells could be correlated with the particular structure of the intimal interstitial tissue and could account for the origin of some protein(s) of the synovial fluid.ERA 178 (Neuroendocrinologie Comparée) du CNRS et INSERM