东莞石马河沿岸土壤重金属污染及生态毒性研究

为研究河水-地下水交互作用对河流沿岸土壤环境质量的影响,以东莞石马河沿岸土壤为研究对象,采集沿岸距离河道不等的6个土壤剖面共31个土样,测定土壤重金属(As、Cd、Cr、Cu、Fe、Mn、Ni、Pb和Zn)含量和土壤水提取液对发光菌的抑制率。结果表明,Cd、Cu、Ni和Zn的含量分别为2.80~11.2mg kg-1、9.70~298mg kg-1、11.4~69.7mg kg-1和40.4~465mg kg-1;Cd的地累积系数为6.06,达到极度污染水平;土壤重金属污染的地累积系数排序为CdZnCuNiCrMnAsPbFe;重金属含量差异与土壤有机质(SOM)含量和土壤微粒组分(63μm)有关,Cr、Cu、Ni、Zn、Mn和Cr、Ni与SOM含量和微粒组分分别呈显著正相关(p0.05或p0.01);土壤剖面毒性单位(∑TU)评价结果为剖面S3S2SbS1S4Sa,其中剖面S3的值最大,为5.51,属于中毒;土壤水提取液对发光菌的抑制率为2.45%~16.5%,为无毒或低毒。     

Effects of probiotic Bacillus cereus toyoi on abdominal fat accumulation in the Japanese quail (Coturnix japonica)

Effects of a commercial probiotic, Bacillus cereus toyoi on abdominal fat accumulation in the Japanese quail fed either a commercial control diet (crude protein (CP), 23.5%; metabolizable energy (ME), 11.7MJ/kg) or a high‐energy diet (CP, 23.0%; ME, 13.8MJ/kg) were investigated. Four‐week‐old male birds (n = 108) were divided into four diet groups: control diet, control with probiotic, high‐energy diet and high‐energy diet with probiotic. At 8 weeks and 12 weeks of age (4 and 8 weeks of probiotic supplementation period, respectively), abdominal fat, muscles and the liver were weighed. The weight of total fat and protein in the muscles and liver were also determined. A rectal temperature was recorded weekly. Bodyweight and feed intake in both diets were not affected by probiotic supplementation. At 8 weeks of age, birds fed the control diet with probiotic had significantly less abdominal fat than those fed without the probiotic, and a similar tendency was seen for both diet groups at 12 weeks of age. The decrease in abdominal fat coincided with an increase in rectal temperature. These results suggest that greater metabolizable energy was consumed through elevation of heat production by supplementation of B. cereus toyoi, with hardly any energy stored as body fat. Probiotic supplementation appears to induce greater muscle weight, higher protein and lower lipid content in muscles by 8 weeks of age, and lower lipid content in muscles and greater liver weight by 12 weeks of age, in the Japanese quail.     

Profiling of plasma metabolites in canine oral melanoma using gas chromatography-mass spectrometry

Malignant melanoma is one of the most common and aggressive tumors in the oral cavity of dog. The tumor has a poor prognosis, and methods for diagnosis and prediction of prognosis after treatment are required. Here, we examined metabolite profiling using gas chromatography-mass spectrometry (GC-MS) for development of a discriminant model for evaluation of prognosis. Metabolite profiles were evaluated in healthy and melanoma plasma samples using orthogonal projection to latent structure using discriminant analysis (OPLS-DA). Cases that were predicted to be healthy using the OPLS discriminant model had no advanced lesions after radiation therapy. These results indicate that metabolite profiling may be useful in diagnosis and prediction of prognosis of canine malignant melanoma.     

Pneumocystis Pneumonia in a Thoroughbred Racehorse

Pneumocystis pneumonia is an opportunistic respiratory infection that occurs in immunocompromised animals. In horses, pneumocystic pneumonia is observed mostly in foals and often progresses rapidly. Here, we report pneumocystic pneumonia in a Thoroughbred racehorse. A 3-year-old Thoroughbred racehorse colt had marked respiratory symptoms for 3 weeks and was unresponsive to antibiotic treatment. At necropsy, firm, tan, patchy lesions were scattered diffusely in the lungs. Microscopically, alveolar septa thickened by proliferation of collagen fibers and infiltration of inflammatory cells were observed. In the alveolar spaces, many brown-black yeast-like organisms similar to cystic forms of Pneumocystis carinii were recognized by staining with Gomori's methenamine silver. Bronchoalveolar lavage fluid (BALF) obtained before necropsy included macrophages engulfing the fungus bodies. Amplified products were obtained from BALF and lung tissue samples by Pneumocystis-specific nested PCR. Phylogenetic analysis based on the 18S rRNA gene sequence revealed that the P. carinii organism from BALF was related to the Pneumocystis spp. detected in other animals and was especially close to P. carinii derived from ferrets. This is a rare case of pneumocystic pneumonia in a colt with chronic pulmonary lesions.     

A review of tower flux observation sites in Asia

Aggregating and sharing the metadata of flux observation sites results in a strong collaboration among various fields of study. Such data sharing will also be a part of the future design of a tower flux observation network in Asia. The aim of this review is to comprehend the state of tower flux observation sites in Asia. There are 109 tower flux observation sites in Asia including 51 forest sites. There are more new sites under construction in Asia than in America and Europe. These sites range from the taiga in Siberia to the rainforest in Southeast Asia, and from the equatorial to polar Koeppen climate zones. There are many highly humid areas in Asia, not only at low latitudes but also at middle latitudes. This climate condition has developed unique vegetation such as lucidophyllous (evergreen broadleaf) forest, which is distributed in warm areas with high precipitation in the growing season. However, there are only a few observations taking place in lucidophyllous forest. Rice paddy fields are also unique land cover in Asia. It is important to accumulate long-term data for rice fields with their management records, because plant activity depends highly on both climate conditions and land-use management. Flux data, especially net ecosystem exchange and related elements, are used for widespread studies not only within the flux-research community but also in other fields of study, for example remote sensing. At present, however, both the quantity and quality of the data are not sufficient for these studies. Regarding the quantity, there are many recently established sites that have not published data yet; regarding quality, flux data include uncertainties caused by methodological problems. Flux researchers are required not only to obtain flux data but also to improve their quality. Meanwhile, data users must understand there are still uncertainties in flux data. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Poly(3-hydroxybutyrate) production using mannitol as a sole carbon source by Burkholderia sp. AIU M5M02 isolated from a marine environment

Fisheries Science - We isolated Burkholderia sp. AIU M5M02, which accumulates poly(3-hydroxybutyrate) [P(3HB)] homopolymer in a nitrogen-limiting mineral salt medium containing mannitol as a sole...     

Spatiotemporal distribution of Flavobacterium psychrophilum and ayu Plecoglossus altivelis in rivers revealed by environmental DNA analysis

Outbreaks of bacterial cold-water disease (BCWD), caused by Flavobacterium psychrophilum, are widespread in Japan, especially among ayu Plecoglossus altivelis. There are few investigations of F. psychrophilum in river water, and its seasonal distribution has not been clarified. We aimed to identify the spatiotemporal dynamics of F. psychrophilum and ayu to provide information that is useful for establishing a countermeasure for BCWD. Quantitative analysis of environmental DNA (eDNA) was used to clarify the year-round dynamics of ayu and F. psychrophilum. We sampled river water from the Nagara and Ibi rivers in Japan, and conducted monthly water sampling and eDNA quantification. Changes in the eDNA concentration of ayu were consistent with the known life histories of the fish. There was a strong negative correlation between the eDNA concentration of F. psychrophilum and water temperature, suggesting a strong dependence of F. psychrophilum dynamics in the river on water temperature. Furthermore, relatively high eDNA concentrations were recorded for both organisms in early summer and fall, suggesting that ayu is infected with F. psychrophilum during these seasons when experiencing up- and downmigration, respectively.

     

气相色谱-质谱法测定小鼠血浆的尼古丁和可替宁

建立了一种同时测定小鼠血浆中尼古丁和可替宁含量的气相色谱-质谱方法.以二苯胺为内标,采用HPDB-225毛细管色谱柱(30 m×0.25 mm i.d.,膜厚0.25μm)和选择离子监测.该方法尼古丁和可替宁的线性范围均为40～1 000 ng/mL,线性相关系数分别为0.998 9和0.999 7,检出限均为2 ng/mL.平均回收率尼古丁为83.2%～94.6%,可替宁为79.3%～101.6%.该方法简便、特异、灵敏、重现性好.