Unsupervised learning approach in defining the similarity of catchments: Hydrological response unit based k-means clustering,a demonstration on Western Black Sea Region of Turkey

This study investigated the similarity of the catchments with the k-means clustering method by using the hydrological response unit (HRU) images of 33 catchments located in the Western Black Sea Region of Turkey. HRUs are the unit cells in hydrological models and these units are important because the same HRUs have the same hydrological behavior regarding weather inputs and water runoff. Catchments that reside inside a cluster will have high hydrological similarity, the catchments of two separate clusters would be dissimilar to each other. With the help of the clustered catchments, an elimination process can be conducted that can save time and effort in basin selection for future hydrological studies. In the study, the basic process sequence was carried out in 5 steps. These steps were creating HRUs, assigning a color to HRUs, creating HRU images, image embedding, and k-means clustering respectively. Silhouette and multidimensional scaling plots were sketched to visually examine the quality of intra-cluster distributions. Considering the silhouette score values, the optimum number of clusters was determined as 8, and the clustered catchments were illustrated on the study area.     

鸡肝细胞中C/EBPα基因的敲低及对糖脂代谢相关基因表达的影响

C/EBPα即CCAAT/增强子结合蛋白α基因,其编码的CCAAT/增强子结合蛋白是重要的转录调控因子,在细胞的分化和代谢过程中发挥着重要的调节作用。试验利用RNAi来敲低鸡LMH细胞系中C/EBPα基因的表达,以研究C/EBPα基因影响脂肪代谢的机制。根据鸡C/EBPα基因的mRNA序列,设计3对siRNA,用RNAi干扰技术来敲低鸡LMH细胞中的C/EBPα基因表达,然后用荧光定量PCR检测C/EBPα基因的表达情况,发现其中的C/EBPα-siRNA-161能够显著降低C/EBPα基因的表达;并将C/EBPα-siRNA-161转染LHM细胞后48 h后,利用荧光定量PCR检测LMH细胞中糖脂代谢相关基因(PCK1、SCD、GLUT2、PPARγ、INS、G6PC、IGF1、IGF2、INSR、STAT3)的表达,发现在LMH细胞中PCK1、G6PC、GLUT2基因的mRNA表达量下降,结果表明C/EBPα基因能影响糖代谢相关基因G6PC、GLUT2、甘油异生相关基因PCK1的表达,证实了C/EBPα基因对鸡肝细胞中的糖脂代谢具有调控作用,通过调控C/EBPα基因的表达将影响糖吸收及甘油异生。     

原条量材设计中木材等级的确定

针对采用标号法进行原条量材设计时原木等级难确定这一问题 ,提出利用双向链表存储木材缺陷的信息 ,编制特定函数的办法 ,来解决这一问题     

辣椒PAP3和PPI蛋白相互作用的鉴定

PAP3(Gen Bank登录号:HM104635)和PPI(Gen Bank登录号:GU812176)基因是控制辣椒花器官发育的B类基因,共同控制花瓣和雄蕊的发育,均属于MADS-box家族基因。为验证PAP3蛋白和PPI蛋白的相互作用,利用酵母双杂交系统,构建pGBKT7-PPI和pGADT7-PAP3酵母表达载体,转化相应酵母AH109感受态细胞后未出现自激活和毒性现象,融合的二倍体酵母(pGBKT7-PPI×pGADT7-PAP3)能在营养缺陷型培养基上生长;同时利用体外GST-Pull down技术,将诱导的GST-PAP3蛋白和His-PPI蛋白孵育,结果均表明,PAP3蛋白和PPI蛋白之间存在特异性相互作用。     

Experimental determination and allometric prediction of vitreous volume, and retina and lens weights in Göttingen minipigs

Objectives To determine the vitreous volume, and retinal and lens wet weights in male and female Göttingen minipigs of different age groups. Procedures Vitreous, lens and retina were isolated from fresh minipig eyes. Vitreous volume, lens and retina weight were measured and allometric scaling was utilized to predict these parameters. Results There were no gender differences in body weights or retina and lens weights in the three age groups examined in this study. For vitreous volumes, females had a significantly larger volume (approximately 10%–12%) than males in the 4–6 and 6–8 month, but not in the 8–11‐month group. The mean body weight increased from 12.2 ± 2.6 kg (4–6 months) to 19.4 ± 4.0 kg (8–11 months). In the same period, the mean vitreous volume increased from 2.00 ± 0.28 to 2.67 ± 0.31 mL, while the mean retinal and lens weights increased from 114 ± 22 to 126 ± 17 mg, and from 298 ± 26 to 392 ± 15 mg, respectively. Allometric analysis between six species for vitreous volume and four species for lens weight covering a weight range of 260‐fold was not able to estimate the vitreous volume, but it did predict the lens weight in 8–11 months minipigs. Conclusions Overall these measurements add important context to intraocular pharmacology studies, and will help in the improved design and interpretation of such experiments.     

Influences of habitat and land cover on fish distributions along a tributary to Lake Ontario,New York

Influences of habitat and land cover on fish distributions were determined along a lentic–lotic gradient along a tributary to Lake Ontario, New York. Nonmetric multidimensional scaling, cluster analysis, and specific characterization methods were used to classify the fish species into five groups based on their similar patterns of distribution, species-specific habitat relationship, and relative abundance observed along the gradient. A stepwise regression approach was used to select the best habitat and land cover variables to explain variations in the distribution pattern of each fish group. Distribution patterns of the five fish groups were significantly explained by either a set of the selected habitat or land cover predictor variables or a combination of both. Of the 10 habitat variables, water depth, current velocity, aquatic plants, algae, woody debris, sand, and rock-bedrock were selected to explain the variations in distribution patterns of one or more fish groups. Of the 16 land cover types, evergreen wetlands, evergreen plantations, successional shrubs, shrub swamps, roads, and urban areas were selected to explain the variations in distribution patterns of at least one fish group.     

Relationships between fish assemblages and habitat characteristics in Iowa’s non‐wadeable rivers

Abstract Non‐wadeable river systems are some of the most diverse aquatic ecosystems, but little work has been conducted to quantify the relationships between fish assemblages and habitat characteristics in them. In 2007 and 2008, 21 reaches were sampled on 16 non‐wadeable rivers across Iowa, USA. Fish were sampled in each reach with three different gears, and habitat characteristics (channel morphology, current velocity, instream cover) were measured using standard procedures. Fish assemblages were structured based on drainage basin and reaches and could be categorised as belonging to one of three groups. Reaches in the Missouri River basin group were narrow and had a high proportion of fine substrate. Reaches in the Mississippi River A group were also narrow but had a high proportion of large rocky substrate. Reaches in the Mississippi River B group tended to be wider, deeper and have higher proportions of fine substrate than the other groups. Fish assemblages were closely related to habitat characteristics and reflected differences among the three groups. Results of this study suggest that stream geomorphology may have a substantial influence on fish assemblage structure in large rivers.