Sustainable Aquaculture for Poverty Alleviation (SAPA): Strategy and implementation

There is general agreement amongst Government and many donors that aquaculture and improved aquatic resources management can make a significant and direct impact on poverty reduction and hunger eradication in Vietnam. The key policy issue is to better support poor and vulnerable groups who depend on or could make use of aquatic resources through the use of the livelihoods perspective. To address this issue the Ministry of Fisheries of Vietnam (MOFI) has prepared this Sustainable Aquaculture for Poverty Alleviation strategy - the SAPA strategy. (Pdf contains 54 pages).

Proceedings of the scoping meeting on Sustainable Aquaculture for Poverty Alleviation (SAPA), Hanoi, Vietnam, 23-25 May 2000

Vietnam has a large number of poor people whose livelihoods depend in various ways on aquatic resources. More than 20 million people living along the coastline are among the most vulnerable and poorest in Vietnam and similarly poor situations occur with more than 10 million population living in mid and highland areas throughout the country. The Government of Vietnam is giving high priority to the poverty alleviation and following several successful government and donor funded projects, it is recognized that aquaculture can and should play an increasingly important role in improving the livelihoods of poor people. (Pdf contains 216 pages).

Defective in Cuticular Ridges (DCR) of Arabidopsis thaliana, a Gene Associated with Surface Cutin Formation, Encodes a Soluble Diacylglycerol Acyltransferase

A key step in the triacylglycerol (TAG) biosynthetic pathway is the final acylation of diacylglycerol (DAG) by DAG acyltransferase. In silico analysis has revealed that the DCR (defective in cuticular ridges) (At5g23940) gene has a typical HX4D acyltransferase motif at the N-terminal end and a lipid binding motif VX(2)GF at the middle of the sequence. To understand the biochemical function, the gene was overexpressed in Escherichia coli, and the purified recombinant protein was found to acylate DAG specifically in an acyl-CoA-dependent manner. Overexpression of At5g23940 in a Saccharomyces cerevisiae quadruple mutant deficient in DAG acyltransferases resulted in TAG accumulation. At5g23940 rescued the growth of this quadruple mutant in the oleate-containing medium, whereas empty vector control did not. Lipid particles were localized in the cytosol of At5g23940-transformed quadruple mutant cells, as observed by oil red O staining. There was an incorporation of 16-hydroxyhexadecanoic acid into TAG in At5g23940-transformed cells of quadruple mutant. Here we report a soluble acyl-CoA-dependent DAG acyltransferase from Arabidopsis thaliana. Taken together, these data suggest that a broad specific DAG acyltransferase may be involved in the cutin as well as in the TAG biosynthesis by supplying hydroxy fatty acid.

A Bifunctional Enzyme That Has Both Monoacylglycerol Acyltransferase and Acyl Hydrolase Activities

Monoacylglycerol acyltransferase (MGAT) catalyzes the synthesis of diacylglycerol, the precursor of triacylglycerol biosynthesis and an important signaling molecule. Here, we describe the isolation and characterization of the peanut (Arachis hypogaea) MGAT gene. The soluble enzyme utilizes invariant histidine-62 and aspartate-67 residues of the acyltransferase motif for its MGAT activity. A sequence analysis revealed the presence of a hydrolase (GXSXG) motif, and enzyme assays revealed the presence of monoacylglycerol (MAG) and lysophosphatidylcholine (LPC) hydrolytic activities, indicating the bifunctional nature of the enzyme. The overexpression of the MGAT gene in yeast (Saccharomyces cerevisiae) caused an increase in triacylglycerol accumulation. Similar to the peanut MGAT, the Arabidopsis (Arabidopsis thaliana) homolog (At1g52760) also exhibited both acyltransferase and hydrolase activities. Interestingly, the yeast homolog lacks the conserved HX4D motif, and it is deficient in the acyltransferase function but exhibits MAG and LPC hydrolase activities. This study demonstrates the presence of a soluble MGAT/hydrolase in plants. The predicted three-dimensional homology modeling and substrate docking suggested the presence of two separate substrate (MAG and LPC)-binding sites in a single polypeptide. Our study describes a soluble bifunctional enzyme that has both MGAT and hydrolase functions.

A soluble diacylglycerol acyltransferase is involved in triacylglycerol biosynthesis in the oleaginous yeast Rhodotorula glutinis

The biosynthesis of triacylglycerol (TAG) occurs in the microsomal membranes of eukaryotes. Here, we report the identification and functional characterization of diacylglycerol acyltransferase (DGAT), a member of the 10 S cytosolic TAG biosynthetic complex (TBC) in Rhodotorula glutinis. Both a full-length and an N-terminally truncated cDNA clone of a single gene were isolated from R. glutinis. The DGAT activity of the protein encoded by RgDGAT was confirmed in vivo by the heterologous expression of cDNA in a Saccharomyces cerevisiae quadruple mutant (H1246) that is defective in TAG synthesis. RgDGAT overexpression in yeast was found to be capable of acylating diacylglycerol (DAG) in an acyl-CoA-dependent manner. Quadruple mutant yeast cells exhibit growth defects in the presence of oleic acid, but wild-type yeast cells do not. In an in vivo fatty acid supplementation experiment, RgDGAT expression rescued quadruple mutant growth in an oleate-containing medium. We describe a soluble acyl-CoA-dependent DAG acyltransferase from R. glutinis that belongs to the DGAT3 class of enzymes. The study highlights the importance of an alternative TAG biosynthetic pathway in oleaginous yeasts.

A generalized Stein's estimation approach to speech enhancement based on perceptual criteria

We address the problem of speech enhancement using a risk- estimation approach. In particular, we propose the use the Stein’s unbiased risk estimator (SURE) for solving the problem. The need for a suitable finite-sample risk estimator arises because the actual risks invariably depend on the unknown ground truth. We consider the popular mean-squared error (MSE) criterion first, and then compare it against the perceptually-motivated Itakura-Saito (IS) distortion, by deriving unbiased estimators of the corresponding risks. We use a generalized SURE (GSURE) development, recently proposed by Eldar for MSE. We consider dependent observation models from the exponential family with an additive noise model,and derive an unbiased estimator for the risk corresponding to the IS distortion, which is non-quadratic. This serves to address the speech enhancement problem in a more general setting. Experimental results illustrate that the IS metric is efficient in suppressing musical noise, which affects the MSE-enhanced speech. However, in terms of global signal-to-noise ratio (SNR), the minimum MSE solution gives better results.

Proceedings of the Learning Workshop on Livelihoods Analysis. Long An, Vietnam 19-20 November 2002

Sustainable Aquaculture for Poverty Alleviation (SAPA) is a strategy under the overall national program for hunger eradication and poverty reduction. This reflects high attention by the Ministry of Fisheries (MOFI) to the poor. Since the strategy was initiated, several actions have been taken. Recently, conferences and meetings were conducted in Hanoi, Thai Nguyen and Quang Tri. Consequently we also have workshops on a regional basis, and today we are pleased to conduct a workshop in Long An on livelihoods analysis. Now at the Ministry, there are more than 340 projects in aquaculture to attack poverty. The launch of SAPA has been given a high priority among support agencies. Recently Mr Gill of the World Bank and the Ministry agreed that they would act to strengthen aquaculture for poverty reduction. So today with the support of the Long An People’s Committee, NACA and STREAM we have a workshop to strengthen learning about livelihoods analysis. (PDF has 61 pages.)

Protein Microarray: "Theory" to "Real Practice"

Fueled by ever-growing genomic information and rapid developments of proteomics–the large scale analysis of proteins and mapping its functional role has become one of the most important disciplines for characterizing complex cell function. For building functional linkages between the biomolecules, and for providing insight into the mechanisms of biological processes, last decade witnessed the exploration of combinatorial and chip technology for the detection of bimolecules in a high throughput and spatially addressable fashion. Among the various techniques developed, the protein chip technology has been rapid. Recently we demonstrated a new platform called “Spacially addressable protein array” (SAPA) to profile the ligand receptor interactions. To optimize the platform, the present study investigated various parameters such as the surface chemistry and role of additives for achieving high density and high-throughput detection with minimal nonspecific protein adsorption. In summary the present poster will address some of the critical challenges in protein micro array technology and the process of fine tuning to achieve the optimum system for solving real biological problems.

Online self-and-peer-assessment for teamwork in architecture and business communications

There is considerable evidence of general student scepticism regarding the purpose of team assignments and high levels of concern for the fairness of assessment procedures when all members of a team receive the same grade. Some educators are similarly anxious about not only the validity of team grades, but also the need to assess ongoing team processes in addition to the final assignment product. This paper offers self-andpeer-assessment (SAPA) as a fair, valid and reliable method of producing information about ongoing team processes. The paper examines a pilot study investigating an online SAPA tool originally developed for a small class of architecture students. This tool is adapted for use for by students completing team assignment in two further architecture design units and for a very large class of 800 business communication students. The sample students studied on four campuses, as well as in off campus and offshore modes. The paper focuses on the initial stages of the study to demonstrate how researchers from very different backgrounds collaborated to adapt the online tool and implement a pilot study whilst maintaining both comparability of assessment and integrity of research design.

Online self and peer assessment in large, multi-campus, multi-cohort contexts

The increasing use of team assignments within higher education is well documented. The driving forces behind this include desires to facilitate reflective and collaborative learning, to develop generic teamwork skills for graduate employment and to reduce the grading workloads of faculty staff. Students however consistently report dissatisfaction when the assessment of team assignments produces a common grade for all team members. Self-andpeer-assessment (SAPA) is presented as a fair, valid and reliable method of producing information about ongoing team processes. This information can provide ongoing feedback to team members and rich formative data to instructors attempting to assess the team process and students’ teamwork skills. This data can also enable individualised summative assessment in dysfunctional teams or situations of uneven team member contributions. Whilst manual SAPA protocols can work effectively for smaller classes, computer-assisted SAPA offers a solution to the problems of large classes. This paper reports on the early stages of an online SAPA tool, originally developed for small classes of architecture students, adapted for use by very large business communication classes comprising up to 1000 students in a semester. This large unit is delivered on four Australian campuses as well as off-campus and in off-shore mode, by up to fourteen instructors at any one time. The paper documents how three researchers from very different backgrounds worked to create their own research team, implement a pilot study, and adapt the online tool, whilst adhering to comparability of assessment constraints and maintaining integrity of research design.

The architecture of peer assessment : do academically successful design students make good team mates in design assignments?

This paper considers the relationship between architecture and construction management students’ overall academic abilities (as measured by Weighted Average Marks [WAMs]), their peer ratings for contributions to team design assignments (as measured by an online Self-and-Peer-Assessment [SAPA] tool), and their specific abilities as building designers (as measured by grades in individual design assignments). The research was conducted to determine whether a student’s prior academic achievements might indicate how well they will work in teams. The research demonstrates a statistically significant relationship between WAMs and SAPA ratings indicating that academically successful students more often than not make good teammates. However, the study also highlights that when peers are assessing contributions to teamwork they are assessing skills and qualities in their teammates other than overall academic ability or the ability to design well. Whilst this study is largely located within the field of design, the findings are relevant to any group work where teachers aim to design assessment that unravels group and individual contribution.

Cloning and characterization of two bistructural S-layer-RTX proteins from Campylobacter rectus

Campylobacter rectus is an important periodontal pathogen in humans. A surface-layer (S-layer) protein and a cytotoxic activity have been characterized and are thought to be its major virulence factors. The cytotoxic activity was suggested to be due to a pore-forming protein toxin belonging to the RTX (repeats in the structural toxins) family. In the present work, two closely related genes, csxA and csxB (for C. rectus S-layer and RTX protein) were cloned from C. rectus and characterized. The Csx proteins appear to be bifunctional and possess two structurally different domains. The N-terminal part shows similarity with S-layer protein, especially SapA and SapB of C. fetus and Crs of C. rectus. The C-terminal part comprising most of CsxA and CsxB is a domain with 48 and 59 glycine-rich canonical nonapeptide repeats, respectively, arranged in three blocks. Purified recombinant Csx peptides bind Ca2+. These are characteristic traits of RTX toxin proteins. The S-layer and RTX domains of Csx are separated by a proline-rich stretch of 48 amino acids. All C. rectus isolates studied contained copies of either the csxA or csxB gene or both; csx genes were absent from all other Campylobacter and Helicobacter species examined. Serum of a patient with acute gingivitis showed a strong reaction to recombinant Csx protein on immunoblots.