Virulence of 32 Salmonella Strains in Mice

Virulence and persistence in the BALB/c mouse gut was tested for 32 strains of Salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies I (enterica), and two representatives of each of the other five subspecies. Only serovar Paratyphi C strain BAA1715 and serovar Typhimurium strain 14028 were fully virulent in mice. Three divergent atypical Enteritidis strains were not virulent in BALB/c, but two efficiently persisted. Most of the other strains in all six subspecies persisted in the mouse intestinal tract for several weeks in multiple repeat experiments although the frequency and level of persistence varied considerably. Strains with heavily degraded genomes persisted very poorly, if at all. None of the strains tested provided immunity to Typhimurium infection. These data greatly expand on the known significant strain-to-strain variation in mouse virulence and highlight the need for comparative genomic and phenotypic studies

Risk Classification Model for Design and Build Projects

The purpose of this paper is to investigate if the various risk sources in Design and Build projects can be classified into three risk groups of cost, time and quality using the discriminant analysis technique. Literature search was undertaken to review issues of risk sources, classification of the identified risks into a risk structure, management of risks and effects of risks all on Design and Build projects as well as concepts of discriminant analysis as a statistical technique. This literature review was undertaken through the use of internet, published papers, journal articles and other published reports on risks in Design and Build projects. A research questionnaire was further designed to collect research information. This research study is a survey research that utilized cross-sectional design to capture the primary data. The data for the survey was collected in Nigeria. In all 40 questionnaires were sent to various respondents that included Architects, Engineers, Quantity Surveyors and Builders who had used Design and Build procurement method for their recently completed projects. Responses from these retrieved questionnaires that measured the impact of risks on Design and Build were analyzed using the discriminant analysis technique through the use of SPSS software package to build two discriminant models for classifying risks into cost, time and quality risk groups. Results of the study indicate that time overrun and poor quality are the two factors that discriminate between cost, time and quality related risk groups. These two discriminant functions explain the variation between the risk groups. All the discriminating variables of cost overrun, time overrun and poor quality demonstrate some relationships with the two discriminant functions. The two discriminant models built can classify risks in Design and Build projects into risk groups of cost, time and quality. These classifications models have 72% success rate of classification of risks in Design and Build projects. These models are strongly recommended for use of clients, Design and Build contractors and Risk Managers for the management, control and mitigation of future risks in new Design and Build projects. These models will offer appreciable improvements in risk management and mitigations which can enhance better management of future Design and Build projects. This study also recommends that clients and contractors using Design and Build approach should watch out for emerging issues of cost overrun and poor quality in their projects as these can dictate classification of newly encountered risks

Weaner pigs fed graded levels of maize offal as replacement for maize. 2. Effect on serum metabolites

No Abstrac