喹乙醇在鱼饲料和鲤鱼组织中的残留量

测定了喹乙醇在鱼饲料和鲤鱼组织中的残留量。用体积分数为 2 0σ/v的甲醇提取饲料中的喹乙醇。用乙腈 -乙酸乙酯 (体积比为 3∶2 )提取鱼组织中的喹乙醇。高效液相色谱条件 :Hypersil-C18为分离柱 ( 12 5mm× 4 0mm) ;流动相为 15σ/v甲醇 ;体积流量 1 0ml·min-1;紫外检测波长 2 60nm。喹乙醇在 2～ 2 0 μg·ml 1线性关系良好 ,相关系数 0 9996。测定下限为 2 0mg·kg 1。     

轮叶党参不同时期各种指标与产量的研究

我们对轮叶党参不同生长时期的形态指标和生理指标进行了研究,结果表明：株高与根分枝数、主根粗、叶面积、根重之间差异显著.茎分枝数与根分枝数、主根粗、叶面积、根重之间差异显著;时间各水平之间差异不显著,说明时间对各个形态指标没有显著的差异,影响较小.根重与轮叶党参的生理指标没有差异.     

Analysis of the carbohydrates in an East African traditional beverage, togwa

In sub-Saharan Africa, togwa is a widely consumed beverage containing saccharified starch as a basis, being made from cereals and their malt flours. Togwa was prepared from maize flour and finger millet malt in a laboratory, and trace element and amino acid contents in the togwa were analyzed. The major constituents of togwa are carbohydrates, which are starch and starch hydrolysates that seem to be smoothly digested after ingestion. Carbohydrates in field and laboratory togwa were analyzed in detail by two different HPLC systems: normal phase chromatography and a gel permeation chromatography-multi angle laser light scattering system. Togwa was found to contain a very wide range of size distributions of molecules from glucose to starch that have molecular masses in the millions. It was concluded that togwa is an easily digestible and nutritious food.     

Nutritional Environment of Tropical Peat Soils in Sarawak,Malaysia Based on Soil Solution Composition

It has been considered that natural peat soils and swamp forest ecosystems in the tropics are quite oligotrophic. This concept seems to be related to the low mineral contents in the soil solid phase of the peat soils. However, some nutritional elements such as K, Mg, Ca, and/or P may be abundant in the soil solution phase and could easily migrate in peat soils. In order to analyze the nutritional environment of peat soils, chemical composition of the soil solid phase and soil solution was compared.

This study was carried out in Naman Forest Reserve, Sibu and in/around Sg. Talau Peat Research Station, Mukah, Sarawak, Malaysia. In both areas, each of the three study sites with a different depth of underlying mineral layer was selected for sampling of soil and soil solution. All the soils studied except for one shallow peat profile were classified into Oligotrophic peat based on Fleischer’s criteria. The soil solution collected monthly showed the following characteristics in its composition.

1. Concentrations of Al, Si, and Fe were higher in the soil solution from the shallow peat than in that from the deep peat, reflecting the effect of underlying mineral layers on the soil solution composition.

2. Concentrations of Na, Mg, and Cl in the soil solution and Na and Mg contents in the soil solid phase reflected the distance from the sea. In the Naman series, accumulation of K and Ca in the soil solution was larger in the surface layer in the deep peat than in the shallow peat, though such clear trend was not observed for the K content in the soil solid phase.

3. The concentrations of N and P were fairly high in the soil solution in all the profiles except for P in the profile near the center of the peat dome. Dissolved P consisted mostly of ortho-phosphate, whereas a larger part of N was in the organic form.

4. At the Sago plantation farm on deep peat, depletion of K and P was observed during the rainy season. Such instability in the concentrations in the soil solution was attributed to forest clear-cutting and subsequent disturbance of nutrient cycling.

In general, the concentrations of N, P, K, and Ca in the soil solution were not low even in the Oligotrophic peat. However, in taking account of the fact that the peat soils showed low mineral contents in the available forms and that the bulk density was also quite low, the potential capacity to supply K, Ca, and/ or P was not necessarily high in spite of the apparent high intensity observed for the soil solution composition. Therefore, from the viewpoint of nutrient dynamics, the potential for the use of reclaimed peat land was considered to be rather limited especially under low input management.     

水稻生长日历模拟模型（RICAM）的调控决策系统（RICOS）研究I水稻调控决策系统（RICOS）的系统结构设计

研究阐述在ＲＩＣＡＭ模型系统、专家知识系统和实时信息收集处理系统支持下的水稻调控决策系统的总体结构设计，使ＲＩＣＡＭ与ＲＩＣＯＳ联结，形成具有显著生产管理功能的决策系统。     

Estimating the success rate of ovulation and early litter loss rate in the Japanese black bear (Ursus thibetanus japonicus) by examining the ovaries and uteri

In order to develop a method for estimating the success/failure rates of reproductive processes, especially those of ovulation and neonate nurturing, in the Japanese black bear (Ursus thibetanus japonicus), we examined offspring status, corpora lutea (CLs), placental scars (PSs) and corpora albicantia (CAs) in 159 females (0-23 years old) killed as nuisances on Honshu Island of Japan during 2001-2009. PSs were found to remain in the uterus at least until November of the year of parturition. CA detectability began to decline after September of the year of parturition. Monthly and age-specific proportions of CL-present females revealed that the post-mating season starts in August, and that the age of first ovulation is 4 years. These results indicate that the success rate of ovulation (SRO: the probability that solitary/non-lactating mature females actually succeed in ovulation) can be estimated by calculating the proportion of CL-present females among > or = 4-year-old females without PSs captured from August to November; the early litter loss rate (ELLR: the probability that parenting females lose all of their cubs [0-year-old offspring] before mating season) can be estimated by calculating the proportion of CL-present females among those with PSs and CAs captured in August or later. The estimated values of SRO and ELLR were 0.93 (62/67) and 0.27 (6/22), respectively.     

Land use affects soil organic carbon of paddy soils: empirical evidence from 6280 years BP to present

Purpose

Submerged rice cultivation has been practiced in China for 7000 years. Empirical evidence on changes of soil organic carbon (SOC) contents in paddy soils over this historical time period is scarce. Therefore, a field study was conducted to investigate the effect of submerged rice cultivation on the accumulation and preservation of SOC in paddies.

Materials and methods

Two buried ancient paddy profiles (6280 years BP, named P-01 and P-03) in the Yangtze Delta of eastern China were excavated to illustrate the development of SOC contents in soils during the evolution of paddies under anthropogenic land use and environmental changes from the prehistoric period to the present time. Trends in SOC concentrations, total nitrogen concentrations, and stable carbon isotope ratio were identified for different points in time.

Results and discussion

Accumulation of organic carbon was found in the paddy soil layers of P-01 at 100–174 cm depth. This site was taken under submerged rice cultivation in about 6280 years BP. The average SOC concentration in the prehistoric paddy topsoil in 100–130 cm depth was 1.27 %, which is seven times higher than that in the adjacent uncultivated land at 103–130 cm depth of P-03. This implies that the paddy soil has experienced substantial CO₂ sequestration under submerged management during that time. By about 3320 years BP, organic carbon contents were halved, potentially due to marine inundation by sea level rise. Up to the year 2003, the SOC contents in all horizons in the present time paddy soil have increased, especially in the surface layer, indicative of continuous rice cultivation. However, due to rapid urbanization and industrialization, the cultivation of paddies in eastern China has gradually been discontinued leading to the loss of SOC stocks of approximately 10 % in a 6-year interval (from 2003 to 2009). A significant relationship between SOC and rice phytolith contents was found in the paddy soil horizons of P-01 (r?=?0.71, p?<?0.01) and P-03 (r?=?0.72, p?<?0.01), suggesting that phytolith-occluded organic carbon could be used as a biomarker to ascertain the development of SOC in the evolution of rice paddies over the past 6000 years.

Conclusions

Submerged rice cultivation led to a noticeable accumulation of SOC in paddies. Phytolith-occluded organic carbon could be used as a biomarker to monitor changes of OC contents in paddy soils.

     

Time-dependent sorption of imidacloprid in two different soils

Time-dependent sorption of imidacloprid [1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine] was investigated with two German soils (sandy loam and silt loam). Soil batches containing the active ingredient (0.33 mg/kg) were incubated for 100 days. After selected aging periods, imidacloprid desorbed by 0.01 M CaCl(2) (soluble phase) and by organic solvents (methanol and acetonitrile) and reflux extraction with acidified methanol (sorbed phase) was determined. Calculated sorption coefficients K(d) and K(oc) increased by a factor of 3.2-3.8 during 100 days of aging. Additionally, the time-dependent sorption was verified by a column leaching experiment with the aged soil. The amount of imidacloprid in column eluates (0.01 M CaCl(2)) decreased compared to total recovered by a factor of approximately 2. Sorption of imidacloprid thus increased with residence time in soil, making it more resistant to leaching. These results are further information to explain the low leaching potential of imidacloprid in the field, despite its high water solubility.     

羊源多杀性巴氏杆菌ompW基因的克隆及生物信息学分析

试验旨在克隆羊源多杀性巴氏杆菌ompW基因,并对其序列进行生物信息学分析。根据GenBank中多杀性巴氏杆菌HN07株ompW基因序列(登录号:CP007040.1),使用DNAMAN 5.0软件设计1对引物,选取高保真酶PrimeSTARMax DNA Polymerase进行PCR反应获取目的基因片段,并对ompW基因的核苷酸序列及预测的氨基酸序列进行生物信息学分析。结果表明,PCR扩增产物约为615bp,编码204个氨基酸。核苷酸同源性比对分析显示,羊源多杀性巴氏杆菌ompW基因与猪源、牛源、禽源多杀性巴氏杆菌同源性较高,而与兔源同源性较低。系统进化树结果发现,羊源多杀性巴氏杆菌ompW基因与猪源多杀性巴氏杆菌ompW基因亲缘关系最近。经生物信息学分析发现,ompW蛋白分子式为C1007H1567N257O283S3,分子质量为21.90ku,理论等电点(pI)为9.16,属碱性蛋白质,疏水指数为96.57,总平均疏水性(GRAVY)为0.173(>0),属于疏水类蛋白;前21位氨基酸为信号肽,第5-27位氨基酸区域存在1个跨膜区,存在N-糖基化位点及磷酸化位点,不存在O-糖基化位点,具有多个B细胞、CTL细胞及Th细胞抗原表位;二级结构的α-螺旋、延伸链、β-转角和无规则卷曲分别占17.65%、35.29%、3.92%和43.14%;三级结构是呈β-桶状的单聚体,隶属于外膜蛋白家族成员之一。本研究结果为进一步阐明羊源多杀性巴氏杆菌侵染宿主过程中自身的抗宿主免疫胁迫机制及疫苗的开发与研制提供了理论依据。