黄河三角洲莱州湾柽柳低效次生林质效等级评价

以黄河三角洲莱州湾柽柳次生灌木生态林为对象,选取林分生长和土壤理化性状等24项指标,采用综合因子法研究柽柳林低效的主要影响因子和低效林划分的主要参数.结果表明:柽柳树木生长指标与反映土壤质量状况的主要指标相关性不明显,仅依据树木的生长状况不能反映柽柳林的低效程度,需采用树木生长和土壤改良指标来综合判断.土壤含盐量、林龄、土壤含水量、单株地上茎和叶生物量及地径是反映低效柽柳林分质效高低的主要指示因子,其次为土壤容重、孔隙度及土壤养分特征.莱州湾柽柳低效林可划分为生长潜力型、轻度低质型、中度低效型、中度低质低效型和重度低质低效型5大类型.依据聚类分析的类平均值探讨了其林分特征、低效原因及经营改造方法.     

生物腐植酸菌剂用做功能性饲料营养添加剂价值初探

目的以生物腐植酸菌剂（BFA）对哺乳动物（SD大鼠）的生理生化、肠道菌群等指标的影响为评价指标,初步探讨BFA用做功能性饲料营养添加剂的价值。方法将四种生物腐植酸菌剂（分别为乳酸菌发酵BFA、芽胞菌发酵BFA、酵母菌发酵BFA以及三菌混合发酵BFA）均按1.5%的比例与常规饲料混合,并以未加入BFA的常规饲料为对照组,分组饲喂啮齿类哺乳动物—SD大鼠,观察实验组和对照组血常规、血生化指标、增重、料重比以及肠道菌群定量分析等指标的差异。结果①血常规：乳酸菌发酵组的白细胞（WBC）、单核细胞（Mon）、中性粒细胞（Neu）较对照组降低,差异有显著性（P〈0.05,P〈0.01）;芽孢菌发酵组中性粒细胞（Neu）较对照组降低,差异有显著性（P〈0.05）。②血生化：乳酸菌发酵组的总蛋白（TP）、白蛋白（Alb）、白/球比值（A/G）较对照组升高,差异有显著性（P〈0.05,P〈0.01,P〈0.05）,总胆红素（TBIL）较对照组降低,差异有显著性（P〈0.05）;芽孢菌发酵组总胆红素（TBIL）较对照组降低,差异有显著性（P〈0.01）。③增重：混合发酵组的总增重和日增重均显著高于对照组（P〈0.05）;乳酸菌发酵组、芽孢菌发酵组、酵母菌发酵组、混合组、对照组饲料增重比分别为：6.70、6.74、6.49、6.09、6.77。④菌群分析：乳酸菌发酵组和混合发酵组的大肠杆菌数量较对照组降低,差异有显著性（P〈0.05）,同时乳酸杆菌数量较对照组显著升高（P〈0.05）。结论各组BFA制剂均对SD大鼠的生理生化、增重、肠道菌群指标有积极的影响,其中以三菌混合发酵BFA效果最佳,具有作为功能性饲料营养添加剂、改善哺乳动物健康的价值。     

Texture analysis of the 3D collagen network and automatic classification of the physiology of articular cartilage

A close relationship has been found between the 3D collagen structure and physiological condition of articular cartilage (AC). Studying the 3D collagen network in AC offers a way to determine the condition of the cartilage. However, traditional qualitative studies are time consuming and subjective. This study aims to develop a computer vision-based classifier to automatically determine the condition of AC tissue based on the structural characteristics of the collagen network. Texture analysis was applied to quantitatively characterise the 3D collagen structure in normal (International Cartilage Repair Society, ICRS, grade 0), aged (ICRS grade 1) and osteoarthritic cartilages (ICRS grade 2). Principle component techniques and linear discriminant analysis were then used to classify the microstructural characteristics of the 3D collagen meshwork and the condition of the AC. The 3D collagen meshwork in the three physiological condition groups displayed distinctive characteristics. Texture analysis indicated a significant difference in the mean texture parameters of the 3D collagen network between groups. The principle component and linear discriminant analysis of the texture data allowed for the development of a classifier for identifying the physiological status of the AC with an expected prediction error of 4.23%. An automatic image analysis classifier has been developed to predict the physiological condition of AC (from ICRS grade 0 to 2) based on texture data from the 3D collagen network in the tissue.     

Occurrence and reduction of human viruses,F‐specific RNA coliphage genogroups and microbial indicators at a full‐scale wastewater treatment plant in Japan

Aims

To evaluate and compare the reductions of human viruses and F‐specific coliphages in a full‐scale wastewater treatment plant based on the quantitative PCR (qPCR) and plate count assays.

Methods and Results

A total of 24 water samples were collected from four locations at the plant, and the relative abundance of human viruses and F‐RNA phage genogroups were determined by qPCR. Of the 10 types of viruses tested, enteric adenoviruses were the most prevalent in both influent and effluent wastewater samples. Of the different treatment steps, the activated sludge process was most effective in reducing the microbial loads. Viruses and F‐RNA phages showed variable reduction; among them, GI and GIII F‐RNA phages showed the lowest and the highest reduction, respectively.

Conclusions

Ten types of viruses were present in wastewater that is discharged into public water bodies after treatment. The variability in reduction for the different virus types demonstrates that selection of adequate viral indicators is important for evaluating the efficacy of wastewater treatment and ensuring the water safety.

Significance and Impact of the Study

Our comprehensive analyses of the occurrence and reduction of viruses and indicators can contribute to the future establishment of appropriate viral indicators to evaluate the efficacy of wastewater treatment.     

The platform for European root science,COST action E38: An introduction and overview

Abstract

Globally, forests cover 4 billion ha or 30% of the Earth's land surface and account for more that 75% of carbon stored in terrestrial ecosystem. However, 20 – 40% of the forest biomass is roots. Roots play a key role in acquisition of water and nutrients from the soil, the transfer of carbon to soil, as well as providing physical stabilisation. In temperate forests of Europe, average biomass of trees is estimated to be ca. 220 t ha^?1, of which 52 t ha^?1 are coarse roots and 2.4 t ha^?1 are fine roots. Thus, forests and their soils belong to the planets largest reservoirs of carbon. As an outcome of a recently established European platform for scientists working on woody roots, COST action E38, a series of papers has been initiated in order to review the current knowledge on processes in and of roots of woody plants and to identify possible knowledge gaps. These reviews concentrate on aspects of roots as indicators of environmental change, biomass of fine roots, and modelling of course root systems. The reviews of roots as indicators of environmental change cover a number of aspects including, specific root length, the calcium to aluminium ratio, root electrolyte leakage, and ectomycorrhiza community composition.     

Vegetable crop irrigation with tertiary filtered municipal wastewater

Abstract

The use of tertiary membrane-filtered municipal wastewater for irrigation as an alternative to natural freshwater sources was evaluated. Membrane filtration was considered as a viable technology to reclaim wastewater for irrigation, and the microbial and heavy metal impact on crops and soil was studied. The results of 2 years of research (2003 – 2004), carried out in Cerignola in the South of Italy, are reported. Tertiary treatment was carried out using a membrane filtration pilot plant with a hollow fibre submerged system. The water produced was used for drip irrigation of three vegetable crops in succession – processing tomato, fennel and lettuce – and compared with conventional water. Microbiological analyses were performed on the water used for irrigation, on soil samples and on marketable crops. Results show that the microbial content of soil and crops did not show relevant differences in relation to the two types of water. The measured values of heavy metals concentration in crops never exceeded toxic values. The filtered wastewater never caused an increase of bacterial concentration in the soil nor on the edible part of crops. Therefore, tertiary filtered municipal wastewater can be considered a valid alternative source of water for vegetable crop irrigation.     

Imaging the early stages of phospholipase C/sphingomyelinase activity on vesicles containing coexisting ordered-disordered and gel-fluid domains

The binding and early stages of activity of a phospholipase C/sphingomyelinase from Pseudomonas aeruginosa on giant unilamellar vesicles (GUV) have been monitored using fluorescence confocal microscopy. Both the lipids and the enzyme were labeled with specific fluorescent markers. GUV consisted of a mixture of phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, and cholesterol in equimolar ratios, to which 5-10 mol% of the enzyme end-product ceramide and/or diacylglycerol were occasionally added. Morphological examination of the GUV in the presence of enzyme reveals that, although the enzyme diffuses rapidly throughout the observation chamber, detectable enzyme binding appears to be a slow, random process, with new bound-enzyme-containing vesicles appearing for several minutes. Enzyme binding to the vesicles appears to be a cooperative process. After the initial cluster of bound enzyme is detected, further binding and catalytic activity follow rapidly. After the activity has started, the enzyme is not released by repeated washing, suggesting a "scooting" mechanism for the hydrolytic activity. The enzyme preferentially binds the more disordered domains, and, in most cases, the catalytic activity causes the disordering of the other domains. Simultaneously, peanut- or figure-eight-shaped vesicles containing two separate lipid domains become spherical. At a further stage of lipid hydrolysis, lipid aggregates are formed and vesicles disintegrate.     

Reliability of a method for evaluating porosity in denture base resins

doi:10.1111/j.1741‐2358.2009.00347.x
Reliability of a method for evaluating porosity in denture base resins Background: The method of porosity analysis by water absorption has been carried out by the storage of the specimens in pure water, but it does not exclude the potential plasticising effect of the water generating unreal values of porosity. Objective: The present study evaluated the reliability of this method of porosity analysis in polymethylmethacrylate denture base resins by the determination of the most satisfactory solution for storage (S), where the plasticising effect was excluded. Materials and methods: Two specimen shapes (rectangular and maxillary denture base) and two denture base resins, water bath‐polymerised (Classico) and microwave‐polymerised (Acron MC) were used. Saturated anhydrous calcium chloride solutions (25%, 50%, 75%) and distilled water were used for specimen storage. Sorption isotherms were used to determine S. Porosity factor (PF) and diffusion coefficient (D) were calculated within S and for the groups stored in distilled water. anova and Tukey tests were performed to identify significant differences in PF results and Kruskal–Wallis test and Dunn multiple comparison post hoc test, for D results (α = 0.05). Results: For Acron MC denture base shape, FP results were 0.24% (S 50%) and 1.37% (distilled water); for rectangular shape FP was 0.35% (S 75%) and 0.19% (distilled water). For Classico denture base shape, FP results were 0.54% (S 75%) and 1.21% (distilled water); for rectangular shape FP was 0.7% (S 50%) and 1.32% (distilled water). FP results were similar in S and distilled water only for Acron MC rectangular shape (p > 0.05). D results in distilled water were statistically higher than S for all groups. Conclusions: The results of the study suggest that an adequate solution for storing specimens must be used to measure porosity by water absorption, based on excluding the plasticising effect.     

秀丽线虫物理低氧损伤模型的建立与应用

目的:利用秀丽线虫研发合适的低氧损伤模型,以更好地揭示低氧生理和低氧病理的分子机制.方法:通过对秀丽线虫进行不同时间的低氧处理,系统观察线虫的死亡率、运动功能、细胞形态及相关蛋白表达水平的变化,分析低氧对线虫的损伤情况.结果:氧浓度为0.2%的物理性低氧可引起秀丽线虫多种细胞形态发生变化,进而导致线虫死亡,且死亡率随低...     

寄主植物叶片物理性状对潜叶昆虫的影响

潜叶昆虫广泛分布于鳞翅目、双翅目、鞘翅目和膜翅目中,其幼虫潜入叶片内部生活和取食,是一类用于研究植物-昆虫-天敌种间关系和协同进化的重要模式生物。有些潜叶昆虫是重要农林害虫。相比外食性昆虫,在叶内取食的潜叶昆虫幼虫更易受到叶片物理性状的直接影响。叶片的着生位置、朝向、大小、颜色和表皮毛等直接决定潜叶虫成虫的取食和产卵选择,从而影响幼虫的空间分布和寄主适应。叶片的某些物理性状也会直接影响幼虫的取食行为、生长发育和被寄生率。研究叶片物理性状的防御作用以及潜叶昆虫对这些防御的适应,有助于了解潜叶昆虫-寄主植物的协同进化。另一方面,外界环境和遗传育种都有可能改变植物叶片的物理特性,而对潜叶害虫产生抗性,从而实现潜叶害虫的可持续生态控制。