SSR genetic diversity assessment of popular pigeonpea varieties in Malawi reveals unique fingerprints

Background: Pigeonpea ( Cajanus cajan L. Millsp.) is a drought tolerant legume of the Fabaceae family and the only cultivated species in the genus Cajanus. It is mainly cultivated in the semi-arid tropics of Asia and Oceania, Africa and America. In Malawi, it is grown as a source of food and income and for soil improvement in intercropping systems. However, varietal contamination due to natural outcrossing causes significant quality reduction and yield losses. In this study, 48 polymorphic SSR markers were used to assess the diversity among all pigeonpea varieties cultivated in Malawi to determine if a genetic fingerprint could be identified to distinguish the popular varieties. Results: A total of 212 alleles were observed with an average of 5.58 alleles per marker and a maximum of 14 alleles produced by CCttc019 (Marker 40). Polymorphic information content (PIC), ranged from 0.03 to 0.89 with an average of 0.30. A neighbor-joining tree produced 4 clusters. The most commonly cultivated varieties, which include released varieties and cultivated land races, were well-spread across all the clusters observed, indicating that they generally represented the genetic diversity available in Malawi, although substantial variation was evident that can still be exploited through further breeding. Conclusion: Screening of the allelic data associated with the five most popular cultivated varieties, revealed 6 markers – CCB1, CCB7, Ccac035, CCttc003, Ccac026 and CCttc019 – which displayed unique allelic profiles for each of the five varieties. This genetic fingerprint can potentially be applied for seed certification to confirm the genetic purity of seeds that are delivered to Malawi farmers.

Selection of polyvalent bacteriophages infecting Salmonella enterica serovar Choleraesuis

Background: Ideally, bacteriophages of pathogenic bacterial hosts should be polyvalent to be able to replicate in an alternative nonpathogenic bacterium. Thus, accidental infection by the original host can be avoided when bacteriophage lysates are used in biocontrol protocols. Results: From 15 wastewater samples, collected at different sites in the V Region in Chile, we selected three bacteriophages (FC, FP, and FQ) capable of productively infecting Salmonella enterica serovar Choleraesuis. By transmission electron microscopy (TEM) observation, the bacteriophages were found to belong to the order Caudoviridae. Molecular analyses indicated that FC, FP, and FQ contained double-stranded DNA genomes, of sizes similar to bacteriophage P22, and distinct recognition sites for the restriction endonucleases HaeIII and HindIII. Assays of host range revealed that the bacteriophages were polyvalent and thus capable of infecting different strains of Escherichia coli and other serovars of Salmonella . Conclusion: We have isolated newbacteriophages of the serovar Choleraesuiswith various potential applications in relation to this pathogenic bacterium.

DNA demethylation during Chrysanthemum floral transition following short-day treatment

Background: Analytical techniques such as methylation-sensitive amplification polymorphism and high-performance liquid chromatography were used to detect variation in DNA methylation of mature Chrysanthemum leaves during the floral transition induced by short-day (SD) treatment. Results: For both early- and late-flowering cultivars, the time from the date of planting to the appearance of the capitulum bud and early blooming were significantly shorter than those of the control. The capitulum development of the early-flowering cultivar was significantly accelerated compared to the control, unlike the late-flowering cultivar. The DNA methylation percentage of leaves was significantly altered during flower development. For the early-flowering cultivar, DNA methylation was 42.2–51.3% before the capitulum bud appeared and 30.5–44.5% after. The respective DNA methylation percentages for the late-flowering cultivar were 43.5–56% and 37.2–44.9%. Conclusions: The DNA methylation percentage of Chrysanthemum leaves decreased significantly during floral development. The decline in DNA methylation was elevated in the early-flowering cultivar compared with the late-flowering cultivar.

Thermotolerant fermenting yeasts for simultaneous saccharification fermentation of lignocellulosic biomass

Lignocellulosic biomass is the most abundant renewable source of energy that has been widely explored as second-generation biofuel feedstock. Despite more than four decades of research, the process of ethanol production from lignocellulosic (LC) biomass remains economically unfeasible. This is due to the high cost of enzymes, end-product inhibition of enzymes, and the need for cost-intensive inputs associated with a separate hydrolysis and fermentation (SHF) process. Thermotolerant yeast strains that can undergo fermentation at temperatures above 40°C are suitable alternatives for developing the simultaneous saccharification and fermentation (SSF) process to overcome the limitations of SHF. This review describes the various approaches to screen and develop thermotolerant yeasts via genetic and metabolic engineering. The advantages and limitations of SSF at high temperatures are also discussed. A critical insight into the effect of high temperatures on yeast morphology and physiology is also included. This can improve our understanding of the development of thermotolerant yeast amenable to the SSF process to make LC ethanol production commercially viable.

Simple approximate MAP inference for Dirichlet processes mixtures

The Dirichlet process mixture model (DPMM) is a ubiquitous, flexible Bayesian nonparametric statistical model. However, full probabilistic inference in this model is analytically intractable, so that computationally intensive techniques such as Gibbs sampling are required. As a result, DPMM-based methods, which have considerable potential, are restricted to applications in which computational resources and time for inference is plentiful. For example, they would not be practical for digital signal processing on embedded hardware, where computational resources are at a serious premium. Here, we develop a simplified yet statistically rigorous approximate maximum a-posteriori (MAP) inference algorithm for DPMMs. This algorithm is as simple as DP-means clustering, solves the MAP problem as well as Gibbs sampling, while requiring only a fraction of the computational effort. (For freely available code that implements the MAP-DP algorithm for Gaussian mixtures see http://www.maxlittle.net/.) Unlike related small variance asymptotics (SVA), our method is non-degenerate and so inherits the “rich get richer” property of the Dirichlet process. It also retains a non-degenerate closed-form likelihood which enables out-of-sample calculations and the use of standard tools such as cross-validation. We illustrate the benefits of our algorithm on a range of examples and contrast it to variational, SVA and sampling approaches from both a computational complexity perspective as well as in terms of clustering performance. We demonstrate the wide applicabiity of our approach by presenting an approximate MAP inference method for the infinite hidden Markov model whose performance contrasts favorably with a recently proposed hybrid SVA approach. Similarly, we show how our algorithm can applied to a semiparametric mixed-effects regression model where the random effects distribution is modelled using an infinite mixture model, as used in longitudinal progression modelling in population health science. Finally, we propose directions for future research on approximate MAP inference in Bayesian nonparametrics.

Supervivencia y mortalidad por tipo de terapia de reemplazo renal, en pacientes con enfermedad renal crónica terminal, en una cohorte de pacientes asegurados en Colombia

En Colombia se ha podido establecer que la incidencia y mortalidad de la Enfermedad Renal Crónica Terminal continúan en aumento en los últimos 6 años a pesar de las estrategias de intervención para prevención y control de la enfermedad implementadas nivel nacional. Este trabajo busca establecer la línea de base para la población asegurada en Colombia, frente a la supervivencia de pacientes en terapia de remplazo renal (TRR).

Estrategia y plan de mercadeo de la empresa YouTube

Esta investigación describe la situación de cómo Youtube se ha convertido a partir de sus estrategias y plan de mercadeo en la plataforma número uno en variedad de clips de películas, vídeos musicales, video de blogs, entre otros; llegando a popularizarse como una red social. Las redes sociales han desarrollado una nueva forma de comunicar y son una herramienta fundamental para la creación de conocimiento colectivo, es el caso de YouTube buscador de contenido audiovisual y red social que permite a millones de usuarios conectarse alrededor del mundo. Esta plataforma rompe las barreras culturales y de comunicación que anteriormente existían a falta de internet. En este sentido se pretende analizar a YouTube desde una perspectiva administrativa enfocada en el área de mercadeo.

Impact of IS/IT Investments on Firm Performance: Does Stakeholder Orientation Matter?

This research project addresses a central question in the IS business value field: Does IS/IT investments impact positively on firm financial performance? IS/IT investments are seen as having an enormous potential impact on the competitive position of the firm, on its performance, and demand an active and motivated participation of several stakeholder groups. Actual research conducted in the Information Systems field, relating IS/IT investments with firm performance use transactions costs economics and resource-based view of the firm to try to explain and understand that relationship. However, it lacks to stress the importance of stakeholder management, as a moderator variable in that relationship. Stakeholder theory sees the firm as the hub centric to the spokes representing various stakeholders who were in essence equidistant to the firm, and survival and continuing profitability of the corporation depend upon its ability to fulfil its economic and social purpose, which is to create and distribute wealth or value sufficient to ensure that each primary stakeholder group continues as part of the corporation’s stakeholder system. Stakeholder theory in its instrumental version, argues that if a firm pays attention to the stakes of all stakeholder groups (and not just shareholders), it will obtain higher levels of financial performance. With this premise in mind, the aim of this paper is to discuss and test the use of stakeholder theory in the IS business value stream of research, in order to achieve a better understanding of the impact of IS/IT investments on firm performance (moderated by stakeholder management). To achieve the expected impact from an IS/IT investment, it is argued that firms need a strong commitment from those stakeholder groups, which lead us to the need of a corporate “stakeholder orientation”. When firm financial performance is measured by returns on assets (ROA), returns on investments (ROI) and returns on sales (ROS), the results show that “stakeholder orientation” impact positively in the relation between IS/IT and firm performance, using a sample of Portuguese large companies.

Electronic Publishing -- a Journal and its Production

The use of the term "Electronic Publishing" transcends any notions of the paperless office and of a purely electronic transfer and dissemination of information over networks. It now encompasses all computer-assisted methods for the production of documents and includes the imaging of a document on paper as one of the options to be provided by an integrated processing scheme. Electronic publishing draws heavily on techniques from computer science and information technology but technical, legal, financial and organisational problems have to be overcome before it can replace traditional publication mechanisms. These problems are illustrated with reference to the publication arrangements for the journal `Electronic Publishing Origination, Dissemination and Design'. The authors of this paper are the co-editors of this journal, which appears in traditional form and relies on a wide variety of support from electronic technologies in the pre-publication phase.

Linking electronic journals - Lessons from the Open Journal project

The Open Journal project has completed its three year period of funding by the UK Electronic Libraries (eLib) programme (Rusbridge 1998). During that time, the number of journals that are available electronically leapt from a few tens to a few thousand. Some of these journals are now developing the sort of features the project has been advocating, in particular the use of links within journals, between different primary journals, with secondary journals data, and to non-journal sources. Assessing the achievements of the project and considering some of the difficulties it faced, we report on the different approaches to linking that the project developed, and summarise the important user responses that indicate what works and what does not. Looking ahead, there are signs of change, not just to simple linking within journals but to schemes in which links are the basis of "distributed" journals, where information may be shared and documents built from different sources. The significance has yet to be appreciated, but this would be a major change from printed journals. If projects such as this and others have provided the initial impetus, the motivation for distributed journals comes, perhaps surprisingly, from within certain parts of the industry, as the paper shows.

Electronic Publishing : the evolution and economics of a hybrid journal.

The technical, social and economic issues of electronic publishing are examined by using as a case study the evolution of the journal Electronic Publishing Origination, Dissemination and Design (EP-odd) which is published by John Wiley Ltd. The journal is a `hybrid' one, in the sense that it appears in both electronic and paper form, and is now in its ninth year of publication. The author of this paper is the journal's Editor-in- Chief. The first eight volumes of EP-odd have been distributed via the conventional subscription method but a new method, from volume 9 onwards, is now under discussion whereby accepted papers will first be published on the EP-odd web site, with the printed version appearing later as a once-per-volume operation. Later sections of the paper lead on from the particular experiences with EP-odd into a more general discussion of peer review and the acceptability of e-journals in universities, the changing role of libraries, the sustainability of traditional subscription pricing and the prospects for `per paper' sales as micro-payment technologies become available.

A quantitative and qualitative evaluation of reports of clinical trials published in six Brazilian dental journals indexed in the Scientific Electronic Library Online (SciELO)

INTRODUCTION: Open access publishing is becoming increasingly popular within the biomedical sciences. SciELO, the Scientific Electronic Library Online, is a digital library covering a selected collection of Brazilian scientific journals many of which provide open access to full-text articles.This library includes a number of dental journals some of which may include reports of clinical trials in English, Portuguese and/or Spanish. Thus, SciELO could play an important role as a source of evidence for dental healthcare interventions especially if it yields a sizeable number of high quality reports. OBJECTIVE: The aim of this study was to identify reports of clinical trials by handsearching of dental journals that are accessible through SciELO, and to assess the overall quality of these reports. MATERIAL AND METHODS: Electronic versions of six Brazilian dental Journals indexed in SciELO were handsearched at www.scielo.br in September 2008. Reports of clinical trials were identified and classified as controlled clinical trials (CCTs - prospective, experimental studies comparing 2 or more healthcare interventions in human beings) or randomized controlled trials (RCTs - a random allocation method is clearly reported), according to Cochrane eligibility criteria. CRITERIA TO ASSESS METHODOLOGICAL QUALITY INCLUDED: method of randomization, concealment of treatment allocation, blinded outcome assessment, handling of withdrawals and losses and whether an intention-to-treat analysis had been carried out. RESULTS: The search retrieved 33 CCTs and 43 RCTs. A majority of the reports provided no description of either the method of randomization (75.3%) or concealment of the allocation sequence (84.2%). Participants and outcome assessors were reported as blinded in only 31.2% of the reports. Withdrawals and losses were only clearly described in 6.5% of the reports and none mentioned an intention-to-treat analysis or any similar procedure. CONCLUSIONS: The results of this study indicate that a substantial number of reports of trials and systematic reviews are available in the dental journals listed in SciELO, and that these could provide valuable evidence for clinical decision making. However, it is clear that the quality of a number of these reports is of some concern and that improvement in the conduct and reporting of these trials could be achieved if authors adhered to internationally accepted guidelines, e.g. the CONSORT statement.