A uniquely African focus: bioinformatics is a field that has grown exponentially in the past few years, and it is becoming increasingly important to collaborate as the field continues to gather momentum

Bioinformatics is a field that has grown exponentially in the past few years, and it is becoming increasingly important to collaborate as the field continues to gather momentum

Molecular evolution of key receptor genes in primates and non-human primates

African primates remain an unexplored source of information required to complete the origin and evolution of many human pathogens. Current studies have shown the importance of several receptor human genes implicated in host resistance or susceptibility to tuberculosis. The validation of these genes in Mycobacterium tuberculosis infection makes them an excellent model system to investigate the mode of selective pressures that may act on pathogen defense genes. To trace the evolutionary history of these genes, the report describes preliminary results for eight receptors human genes having either a significant or a possible association with Tuberculosis (TB). By using a combination of maximum likelihood approaches, evidence of positive selection were detected for four genes. The analysis between species, nevertheless, shows a clear pattern of nucleotide variation mostly compatible with purifying selection.South African Research Chair Initiative (DST) National Research Foundation of South Afric

STOP TALKING! Inhibition of speech is affected by word frequency and dysfunctional impulsivity

Speaking is a complex natural behavior that most people master very well. Nevertheless, systematic investigation of the factors that affect adaptive control over speech production is relatively scarce. The present experiments quantified and compared inhibitory control over manual and verbal responses using the stop-signal paradigm. In tasks with only two response alternatives, verbal expressions were slower than manual responses, but the stopping latencies of hand and verbal actions were comparable. When engaged in a standard picture-naming task using a large set of pictures, verbal stopping latencies were considerably prolonged. Interestingly, stopping was slower for naming words that are less frequently used compared to words that are used more frequently. These results indicate that adaptive action control over speech production is affected by lexical processing. This notion is compatible with current theories on speech self-monitoring. Finally, stopping latencies varied with individual differences in impulsivity, indicating that specifically dysfunctional impulsivity, and not functional impulsivity, is associated with slower verbal stopping

Bilingual language control: An event-related brain potential study

This study addressed how bilingual speakers switch between their first and second language when speaking. Event-related brain potentials (ERPs) and naming latencies were measured while unbalanced German (L1)-Dutch (L2) speakers performed a picture-naming task. Participants named pictures either in their L1 or in their L2 (blocked language conditions), or participants switched between their first and second language unpredictably (mixed language condition). Furthermore, form similarity between translation equivalents (cognate status) was manipulated. A cognate facilitation effect was found for L1 and L2 indicating phonological activation of the non-response language in blocked and mixed language conditions. The ERP data also revealed small but reliable effects of cognate status. Language switching resulted in equal switching costs for both languages and was associated with a modulation in the ERP waveforms (time windows 275-375 ms and 375-475 ms). Mixed language context affected especially the L1, both in ERPs and in latencies, which became slower in L1 than L2. It is suggested that sustained and transient components of language control should be distinguished. Results are discussed in relation to current theories of bilingual language processing

Neural correlates of verbal feedback processing: an fMRI study employing overt speech

Speakers use external auditory feedback to monitor their own speech. Feedback distortion has been found to increase activity in the superior temporal areas. Using fMRI, the present study investigates the neural correlates of processing verbal feedback without distortion. In a blocked design, the following conditions were presented: (1) overt picture-naming, (2) overt picture-naming while pink noise was presented to mask external feedback, (3) covert picture-naming, (4) listening to the picture names (previously recorded from participants' own voices), and (5) listening to pink noise. The results show that auditory feedback processing involves a network of different areas related to general performance monitoring and speech-motor control. These include the cingulate cortex and the bilateral insula, supplementary motor area, bilateral motor areas, cerebellum, thalamus and basal ganglia. Our findings suggest that the anterior cingulate cortex, which is often implicated in error-processing and conflict-monitoring, is also engaged in ongoing speech monitoring. Furthermore, in the superior temporal gyrus, we found a reduced response to speaking under normal feedback conditions. This finding is interpreted in the framework of a forward model according to which, during speech production, the sensory consequence of the speech-motor act is predicted to attenuate the sensitivity of the auditory cortex. Hum Brain Mapp 2007. © 2007 Wiley-Liss, Inc

The influence of stakeholder power, proximity and urgency on the selection and prioritization of projects within IT project portfolio management

Includes bibliographical references (leaves 118-122).IT investments constitute a major portion of the capital budgets of many organizations. It can be challenging to select the right projects that fit the corporate strategy to maximize value for the organization. In the past, senior executives focused on projects that met three criteria, namely being on-time, on budget and in scope. However, a shift has occurred as a result of the fact that senior executives are more concerned about the right mix of projects that will best utilise the organization's resources and deliver long-range growth. Some of the benefits of IT Project Portfolio Management (IT PPM) are to provide executives with the ability to monitor projects ensure business alignment and identify risks quickly. It is argued that maintaining a balanced portfolio of diverse projects can reduce the risk of an individual project and can produce a higher rate of return

TSS seq based core promoter architecture in blood feeding Tsetse fly (Glossina morsitans morsitans) vector of Trypanosomiasis

A comprehensive illustration of the TSS and promoter identification pipeline. (PNG 184 kb