Insights into nitrogen fixing traits and population structure analyses in cowpea (Vigna unguiculata L. Walp) accessions grown in Ghana.

With legumes, symbiotic N2 fixation can meet the species N demand and reduce the over-reliance on chemical fertilizers in tropical regions where N deficiency is a major factor limiting crop yields and increased agricultural sustainability. Therefore, to optimize the use of cowpea (Vigna unguiculata L. Walp) germplasm in effective breeding, evaluation of genetic diversity and quantification of N2 fixation are essential prerequisites. The aim of this study was to explore the level of diversity using SSR markers and N2-fixing traits in a set of cowpea germplasm grown in Ghana. We analysed 49 cowpea accessions collected from Northern Ghana using qualitative vegetative and N2 fixation traits, and simple sequence repeat (SSR) markers. Experimental field results revealed considerable morpho-physiological variation for plant growth habits, grain yield and symbiotic performance between and among the cowpea accessions. Results from both the 15N natural abundance and ureides in the xylem sap were able to descriminate between high and low levels of N2 fixation in cowpea accessions. Five subpopulations were identified within accessions inferred from STRUCTURE 2.3.4. A general linear model was used to assess the association of SSR markers with N2-fixing traits. There were significant (p ≤ 0.05) links between SSR markers and symbiosis-related traits such as nodule number, nodule dry weight, shoot dry weight, N-fixed, N derived from air (Ndfa), and relative uried-N (RU-N).

Enriched environment exposure accelerates rodent driving skills.

Although rarely used, long-term behavioral training protocols provide opportunities to shape complex skills in rodent laboratory investigations that incorporate cognitive, motor, visuospatial and temporal functions to achieve desired goals. In the current study, following preliminary research establishing that rats could be taught to drive a rodent operated vehicle (ROV) in a forward direction, as well as steer in more complex navigational patterns, male rats housed in an enriched environment were exposed to the rodent driving regime. Compared to standard-housed rats, enriched-housed rats demonstrated more robust learning in driving performance and their interest in the ROV persisted through extinction trials. Dehydroepiandrosterone/corticosterone (DHEA/CORT) metabolite ratios in fecal samples increased in accordance with training in all animals, suggesting that driving training, regardless of housing group, enhanced markers of emotional resilience. These results confirm the importance of enriched environments in preparing animals to engage in complex behavioral tasks. Further, behavioral models that include trained motor skills enable researchers to assess subtle alterations in motivation and behavioral response patterns that are relevant for translational research related to neurodegenerative disease and psychiatric illness.

Diagnosis delay and duration of hospitalisation of patients with Buruli ulcer in Nigeria.

BACKGROUND: Delayed diagnosis of Buruli ulcer can worsen clinical presentation of the disease, prolong duration of management, and impose avoidable additional costs on patients and health providers. We investigated the profile, delays in diagnosis, duration of hospitalisation, and associated factors among patients with Buruli ulcer in Nigeria. METHODS: This was a prospective cohort study of patients with Buruli ulcer who were identified from a community-based survey. Data on the patients' clinical profile, delays in diagnosis and duration of hospitalisation were prospectively collected. RESULTS: Of 145 patients notified, 125 (86.2%) were confirmed by one or more laboratory tests (81.4% by PCR). The median age of the patients was 20 years, 88 (60.7%) were >15years old and 85 (58.6%) were females. In addition, 137 (94.5%) were new cases, 119 (82.1%) presented with ulcers and 110 (75.9%) had lower limb lesions. The mean time delay to diagnosis was 50.6 (±101.9) weeks. The mean duration of hospitalisation was 108 (±60) days. Determinants of time delay to diagnosis were higher disease category (p=0.001) and laboratory confirmation of disease (p=0.02). Determinants of longer hospitalisation were; multiple lesions (p=0.035), and having functional limitation at diagnosis and undertaking surgery (p=0.003). CONCLUSIONS: Patients with Buruli ulcer have very long time delays to diagnosis and long hospitalisation during treatment. This calls for early case-finding and improved access to Buruli ulcer services in Nigeria.