Genetic variation studies in Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae) from oil palm plantations using random amplified microsatellite (RAMs) markers

Randomly amplified microsatellite markers were used to study the genetic variation among six populations of Oryctes rhinoceros L. which were collected from oil palm plantations in Selangor, Perak, Pahang and Medan. Samples were collected using light and pheromone trapping for the purpose of obtaining two populations per site study. Thirty individual beetles per population were screened using seven randomly amplified microsatellite primers. Beetles were not attracted to light traps at Pahang and Medan. This resulted in only pheromone populations being caught there. Distances calculated based on the similarity coefficient of Nei and Li (1979) ranged between 0.422 and 0.736. Seventy eight reproducible loci were generated using the seven primers and all the loci were polymorphic. The dendrogram constructed produced two major clusters. Based on the dendrogram, the clusterings were observed to be influenced by preference to trapping system as well as geographical distance. The separation of clustering between Perak Pheromone (PP) and Perak Light (PL) is important as it gives rise to the possibility for the presence of two groups of O. rhinoceros based on their preference toward light and pheromone trap. However, further studies using codominant markers especially single locus DNA microsatellite markers are required to understand the population genetic structure and to further validate the presence of a cryptic species complex.Keywords: Oryctes rhinoceros, RAMs, genetic variatio

Development of microsatellite markers for Helopeltis theivora waterhouse (Hemiptera: Miridae)

Helopeltis theivora is an important pest of cocoa, tea, mangoes and ornamental plants in Asia. In the effort to control this insect pest effectively, information on its population genetics is needed. Single locus DNA microsatellites are very efficient in being able to provide such information when they are used in the study of the population structures of organisms as they are co-dominant markers. As no such marker is available for this species yet, here we reported in our work, the isolation and development of six of such markers which were found to be polymorphic when tested on samples from three populations of this insect in Peninsular Malaysia

The influential of physico-chemical parameters on the distributions of oligochateas (Limnodrilus sp.) at the polluted downstream of the tropical Langat River, Peninsular Malaysia

The influential physico-chemical parameters on the spatial and temporal distribution of oligochateas (Limnodrilus sp.) at the polluted downstream of Langat River were studied in comparison to the unpolluted upstream for 10-months sampling from March 1998 to February 1999. Based on the correlation analysis (CA) and multiple stepwise regression analysis (SRA), the distribution, abundance and density of Limnodrilus sp. were almost consistent during the ten time samplings from April 1998 to February 1999. Based on CA, the density and distribution of Limnodrilus sp. correlated negatively with the pH and dissolved oxygen (DO) while positively correlated with conductivity, biological oxygen demand (BOD), NO3, NH3, total suspended solids (TSS), chemical oxygen demand (COD) and dissolved concentrations of Cu and Zn. Based on SRA, most of the above parameters are selected as influential factors in affecting the distribution and presence of Limnodrilus sp. on the tropical river. This indicated that the Limnodrilus sp. is a pollutant resistant worm since they can survive in the poor water quality ecosystem. These results based on CA and SRA signified the resistance and tolerance of Limnodrilus sp. survived at the polluted ecosystem of the tropical river. Hence, Limnodrilus sp. is a good bioindicator of polluted rivers in the tropical ecoregion. Journal of Applied Sciences and Environmental Management Vol. 10(3) 2006: 135-14

Effects of fibre content and textile structure on dynamic-mechanical and shape-memory properties of ELO/flax biocomposites

Biocomposites were prepared using epoxidized linseed oil (ELO) and flax fibre reinforcements in different assemblies. ELO was cured by two different anhydrides to check how its thermomechanical properties can be influenced. As reinforcements nonwoven mat, twill weave and quasi-unidirectional textile fabrics with two different yarn finenesses were used. Their reinforcing effect was determined in dynamic mechanical analysis (DMA) in flexure. DMA served also to determine the glass transition temperature (Tg). Shape memory properties were derived from quasiunconstrained flexural tests performed near to the Tg of the ELO and its biocomposites. Flax reinforcement reduced the Tg that was attributed to off-stoichiometry owing to chemical reaction between the hydroxyl groups of flax and anhydride hardener. The shape memory parameters were moderate or low. They were affected by both textile content and type

QUALITATIVE EVALUATION OF A POLYTECHNIC LIBRARY AS A LEARNING & SOCIAL HUB

Abstract The purpose of this study is to evaluate the effectiveness of a polytechnic library as a social and learning space for the institution. The Republic Polytechnic library is the first library in Singapore to conceive and utilize physical space based on the Problem-Based Learning pedagogy. The study provides insights as to how this library functions as an integrated hub for work, life and play; which may be useful for library managers interested in designing library spaces to encourage socialisation, relaxation and discussion. The study was conducted in 2007 with a sample size of 15 students and staff. A qualitative survey research method, involving the Critical Incident Technique, was used to evaluate the library's performance as a social hub. Results from the study revealed that the top three positive values perceived by respondents were Library Atmosphere, Design, and Function of the library respectively. Majority of the respondents agreed that the library's living-room concept suited the problem-based learning environment well. Through this study, the authors created an evaluation tool useful for the library to conduct future assessments. By implementing this framework evaluators can gain insights to user perceptions and aid them in future decision-making process. In addition, learning points were suggested from the experiences of Republic Polytechnic which used library space in an unconventional manner. Background At the Republic Polytechnic (RP) library, the use of space is essential. It is the first library in Singapore to conceive and use physical space differently from other academic libraries. Based on the Problem-Based Learning pedagogy that it has adopted, spaces in the library are intentionally designed for group work and discussions. The choice of furniture, the library provides numerous large tables and chairs to allow students to gather and engage in group discussions. Shelves are designed to be movable so that they can double-up as space dividers to facilitate small group discussions within the same space. The library also provides unconventional facilities such as X-Box consoles, card and board games, pool tables, electric instruments (piano and guitar) for students to freely utilize during their information search. It has recently launched its new website 1 and is working on the library blog as well. In fact, the library hopes to suppress silence rather than noise. Therefore, the library aims to support its problem-based learning community through ensuring that the use of its space is designed to allow users to experience new things, create new discoveries and gather in groups for conversations and discussions just as they would in their own living room space. As such the study hopes to evaluate the library's success in its usage of space to construct an environment suitable for the institution. The research moves away from traditional assessment of quantitative assessment of library's success and impact through designing a qualitative evaluation approach. Research Objectives The purpose of this study is to examine the Republic Polytechnic library as an important social and learning space for its school community. The study evaluates how well the library performs its role as 1 RP library website can be found at http://www.rp.sg/lib 27

IL11 stimulates ERK/P90RSK to inhibit LKB1/AMPK and activate mTOR initiating a mesenchymal program in stromal, epithelial, and cancer cells

IL11 initiates fibroblast activation but also causes epithelial cell dysfunction. The mechanisms underlying these processes are not known. We report that IL11-stimulated ERK/P90RSK activity causes the phosphorylation of LKB1 at S325 and S428, leading to its inactivation. This inhibits AMPK and activates mTOR across cell types. In stromal cells, IL11-stimulated ERK activity inhibits LKB1/AMPK which is associated with mTOR activation, ⍺SMA expression, and myofibroblast transformation. In hepatocytes and epithelial cells, IL11/ERK activity inhibits LKB1/AMPK leading to mTOR activation, SNAI1 expression, and cell dysfunction. Across cells, IL11-induced phenotypes were inhibited by metformin stimulated AMPK activation. In mice, genetic or pharmacologic manipulation of IL11 activity revealed a critical role of IL11/ERK signaling for LKB1/AMPK inhibition and mTOR activation in fatty liver disease. These data identify the IL11/mTOR axis as a signaling commonality in stromal, epithelial, and cancer cells and reveal a shared IL11-driven mesenchymal program across cell types

Site-specific incorporation of phosphotyrosine using an expanded genetic code.

Access to phosphoproteins with stoichiometric and site-specific phosphorylation status is key to understanding the role of protein phosphorylation. Here we report an efficient method to generate pure, active phosphotyrosine-containing proteins by genetically encoding a stable phosphotyrosine analog that is convertible to native phosphotyrosine. We demonstrate its general compatibility with proteins of various sizes, phosphotyrosine sites and functions, and reveal a possible role of tyrosine phosphorylation in negative regulation of ubiquitination

CASED: Curriculum Adaptive Sampling for Extreme Data Imbalance

We introduce CASED, a novel curriculum sampling algorithm that facilitates the optimization of deep learning segmentation or detection models on data sets with extreme class imbalance. We evaluate the CASED learning framework on the task of lung nodule detection in chest CT. In contrast to two-stage solutions, wherein nodule candidates are first proposed by a segmentation model and refined by a second detection stage, CASED improves the training of deep nodule segmentation models (e.g. UNet) to the point where state of the art results are achieved using only a trivial detection stage. CASED improves the optimization of deep segmentation models by allowing them to first learn how to distinguish nodules from their immediate surroundings, while continuously adding a greater proportion of difficult-to-classify global context, until uniformly sampling from the empirical data distribution. Using CASED during training yields a minimalist proposal to the lung nodule detection problem that tops the LUNA16 nodule detection benchmark with an average sensitivity score of 88.35%. Furthermore, we find that models trained using CASED are robust to nodule annotation quality by showing that comparable results can be achieved when only a point and radius for each ground truth nodule are provided during training. Finally, the CASED learning framework makes no assumptions with regard to imaging modality or segmentation target and should generalize to other medical imaging problems where class imbalance is a persistent problem.Comment: 20th International Conference on Medical Image Computing and Computer Assisted Intervention 201