A characterization of the soils and sediments in contaminated sites and rivers using petroleum biomarker compounds

Journal of Soils and Sediments - The objective of this study is to reveal the presence of petroleum biomarkers in sediments of contaminated sites and to prove the existence of these compounds in...     

种公鸡的饲养与选择

1 种公鸡的管理目标 为提高种公鸡的利用率与孵化率,良好的种公鸡管理不可缺少,种公鸡的管理目标包括:提高下代孵化率与整齐度;采取良好的农场管理与生物安全措施以尽量增加下代总数.     

Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea

The Baltic Sea is a stratified, semienclosed sea typified by a low-salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing results from a survey carried out during the 1995 spawning period in the Bornholm Basin, at present the main spawning area of this stock. Cod distribution, abundance and population structure were estimated from hydroacoustic and trawl data and related to hydrographic parameters as well as to bottom depth. In the central basin, cod were aggregated in an intermediate layer about 15 m thick. This area of peak abundance was defined at its upper limit by the halocline and at the lower limit by oxygen content. The majority of individuals caught in the basin centre were in spawning or pre-spawning condition with a high proportion of males to females. On the basin slopes, aggregations of cod were found near the bottom. These individuals were mainly immature and maturing stages with an increasing proportion of females to males with size. Salinity and oxygen conditions were found to be the major factors influencing the vertical and horizontal distribution of adult cod. Abundance of immature cod was also positively related to decreasing bottom depths. The effect of temperature was minor. The observed size- and sex-dependent spawning aggregation patterns, in association with habitat volume and stock size, may influence cod catchability and thereby the assessment and exploitation patterns of this stock.     

牛磺酸对黄瓜幼苗生长和生理特性的影响

采用牛磺酸溶液培育黄瓜幼苗,牛磺酸浓度分别为10、100、500、1000、5000mg·L-1,测定牛磺酸对黄瓜幼苗生长指标和生理特性指标包括光合作用PSⅡ的光化学效率、细胞膜相对透性和膜脂过氧化的影响。结果表明,适量浓度的牛磺酸处理可明显促进黄瓜幼苗的生长、增强幼苗的素质和促进壮苗的形成,并在一定程度上提高黄瓜幼苗叶片的光化学效率,降低细胞膜相对透性和膜脂过氧化产物的含量,最适处理浓度约为500mg·L-1,说明牛磺酸对黄瓜幼苗细胞膜有一定的保护作用。     

Plasma Progesterone Profile in Ovariectomized Beef Cows after Intra-vaginal Insertion of New, Once-used or Twice-used CIDR

Objective of this study was to show plasma progesterone concentrations in ovariectomized beef cows after treatment with new, once-used and twice-used controlled internal drug-releasing devices (CIDRs). Four ovariectomized beef cows were used for the experiment. Plasma concentrations of progesterone were quantified using a validated ELISA. The CIDR was inserted into vagina of cows by using a standard CIDR applicator and then removed 7 days after insertion. One week later, once-used CIDR was inserted and removed on day 7. Twice-used CIDR was, then inserted at an interval of 7 days. Mean plasma concentrations of progesterone 24 h after new CIDR insertion was 4.0 ± 0.1 ng/ml, which thereafter decreased gradually to 1.4 ± 0.1 ng/ml at day 7. In cows treated with once-used CIDR or twice-used CIDR, mean plasma progesterone concentrations at day 1 were 2.4 ± 0.2 or 1.8 ± 0.2 ng/ml and 1.0 ± 0 or 0.9 ± 0.1 ng/ml at day 7 respectively. The results suggest that once-used CIDR may be still effective to produce luteal phase progesterone concentrations in plasma in non-suckling beef cows.     

Natural Product Chemistry of Gorgonian Corals of the Family Plexauridae Distributed in the Indo-Pacific Ocean

The structures, names, bioactivities and references of 105 natural products obtained from gorgonian corals belonging to the family Plexauridae with an Indo-Pacific distribution are described in this review. All compounds mentioned in this review were obtained from gorgonian corals belonging to the genera Astrogorgia, Bebryce, Echinomuricea, Euplexaura and Menella.     

Collaborative non-self recognition system in S-RNase-based self-incompatibility

Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations. However, it remained puzzling how SLF, with much lower allelic sequence diversity than S-RNase, might have the capacity to recognize a large repertoire of non-self S-RNases. We used in vivo functional assays and protein interaction assays to show that in Petunia, at least three types of divergent SLF proteins function as the pollen determinant, each recognizing a subset of non-self S-RNases. Our findings reveal a collaborative non-self recognition system in plants.     

Self-organizing map network for automatically recognizing color texture fabric nature

The method of recognizing color texture brought forth in the present study is to employ unsupervised learning network to automatically recognize the fabric type and the main texture types. Firstly, the color scanner is adopted to extract fabric image which is afterwards saved as the digital image. Secondly,CIE-Lab color model is taken to obtain the feature value and wavelet transform is utilized to display the texture of the fabric image. Thirdly, co-occurrence matrix is employed to figure out the feature values of the texture structure such as angular second moment, entropy, homogeneity, contrast. Finally, self-organizing map (SOM) network is used as the classifier. The experiment result shows that the study can automatically and accurately classify the fabric types (including shuttle-woven fabric, jersey fabric and non-woven fabric) and main texture type of the fabric (such as plain weave, twill weave, satin weave, single jersey, double jersey and non-woven fabric).     

Purification and characterization of a novel extracellular tripeptidyl peptidase from Rhizopus oligosporus

A novel extracellular tripeptidyl peptidase (TPP) was homogenously purified from the culture supernatant of Rhizopus oligosporus by sequential fast protein liquid chromatography. The purified enzyme was a 136.5 kDa dimer composed of identical subunits. The effects of inhibitors and metal ions indicated that TPP is a metallo- and serine protease. TPP was activated by divalent cations, such as Co(2+) and Mn(2+), and completely inhibited by Cu(2+). Enzyme activity was optimal at pH 7.0 and 45 °C with a specific activity of 281.9 units/mg for the substrate Ala-Ala-Phe-pNA. The purified enzyme catalyzed cleavage of various synthetic tripeptides but not when proline occupied the P1 position. Purified TPP cleaved the pentapeptide Ala-Ala-Phe-Tyr-Tyr and tripeptide Ala-Ala-Phe, confirming the TPP activity of the enzyme.     

Using Seven Types of GM (1, 1) Model to Forecast Hourly Particulate Matter Concentration in Banciao City of Taiwan

In this study, seven types of first-order and one-variable grey differential equation model (abbreviated as GM (1, 1) model) were used to predict hourly particulate matter (PM) including PM₁₀ and PM_2.5 concentrations in Banciao City of Taiwan. Their prediction performance was also compared. The results indicated that the minimum mean absolute percentage error (MAPE), mean squared error (MSE), root mean squared error (RMSE), and maximum correlation coefficient (R) was 14.10%, 25.62, 5.06, and 0.96, respectively, when predicting PM₁₀. When predicting PM_2.5, the minimum MAPE, MSE, RMSE, and maximum R value of 15.24%, 11.57, 3.40, and 0.93, respectively, could be achieved. All statistical values revealed that the predicting performance of GM (1, 1, x ⁽⁰⁾), GM (1, 1, a), and GM (1, 1, b) outperformed other GM (1, 1) models. According to the results, it revealed that GM (1, 1) GM (1, 1) was an efficiently early warning tool for providing PM information to the inhabitants.