Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on Plant Species Recovery in Kondoa Irangi Hills, Tanzania

Fertilization, mulching, imported seed bank seeding and seedlings were applied to triplicates of 1m x1m plots at Chakwe and Gubali sites in Kondoa Irangi Hills, Tanzania. Responses tested were seedling recruitment, species turnover, species’ biomass, mortality of seedlings, total number of perennial and woody species recruited and leguminous species. There were high significant correlations of 0.85 and 0.87 between seedling recruitment and mortality in both sites, indicating that other factors, probably aridity, rather than prevailing site conditions were likely to be important determinants of mortality. Inorganic fertilization was not an efficient means of improving short-term productivity, seedling recruitment or increased number of species. In other words, fertilization was negatively correlated to the above factors mentioned. Mulching treatment had an effect of increasing mortality of non-woody species and selectively favoring the establishment of woody species. The interactions between seeding, seed bank and seedlings treatments increased the overall number of species (species turnover) in the study area. Direct sowing of seeds with desired traits into the soil to enhance seedling recruitment and species diversity is recommended over imported seed bank due to the costs involved in mobilizing large volumes of soil as well as availability of proper seed bank soil.Tanz. J. Sci. Vol 36 2010, 19-3

Seed longevity of dominant plant species from degraded savanna in semi-arid Tanzania

Artificially buried seeds were followed by periodic exhumation and germination during 21 months in Kondoa Irangi Hills, central Tanzania. Viable seeds from thirteen selected species were buried in polythene envelopes at a depth of 15 cm below woodland vegetation. Lethalgermination, fungal decay and insect infestation were singled out as the most important contributors to loss of viability among seeds. Hierarchical clustering based on a seed’s mean viability, seed shape and presence or absence of dispersal appendages, produced three distinct groups: (1) non-dormant seeds (2) seeds with enforced dormancy and (3) seeds with seed coat imposed dormancy. The low decay constant of some species is an indication of their abilities to form persistent seed banks. The intermittent and extended germination of seeds of the same species from the same batch shown by some species may be regarded as an ecological adaptation to prevent synchronous germination in unpredictable harsh environments, whereas prompt germination of some Acacia seeds may be viewed as a strategy to avoid seed predation in the soil. Seed dormancy, which predicts seed longevity, is strongly dependent on seed moisture content and partly on other environmental factors, notably low temperatures, light and increased carbon dioxide levels

Improving propagation success of Dalbegia melanoxylon (African blackwood) in Tanzania (I): Characterization of mycorrhizal associated with D. melanoxylon (African blackwood) in Tanzania

Dalbergia melanoxylon is a plant with valuable wood in the world and therefore is over harvested for timber while its regeneration is very low. The propagation efforts by techniques such as tissue culture or mycorrhiza have not been investigated which instigated conduction of this study. Soil and cuttings were collected from Kilwa, Kilosa and Babati for rooting test, potting media and soil characterization. The results showed that fresh soil improved rooting characteristics while sterilized soil did not due to the presence of mycorrhiza in fresh soil compared to none in sterilized media. The overall rooting in fresh soil in non-mist propagator was higher, 100% for softwood and 37% for root cuttings while none rooted in the open nursery. The results revealed that there was no significant correlation between rooting and collection sites while cutting type and the soil type used significantly influenced rooting. Softwood cuttings that weighed less than 15g significantly increased rooting at (P < 0.05) compared to cuttings that weighed above 15g. It was recommended to propagate Dalbergia melanoxylon using softwood cuttings placed in a non-mist propagator and using fresh soil infected with mycorrhiza.Key words: Dalbergia melanoxylon, non-mist propagator, rooting

High-performance hybrid oxide catalyst of manganese and cobalt for low-pressure methanol synthesis

Carbon dioxide capture and use as a carbon feedstock presents both environmental and industrial benefits. Here we report the discovery of a hybrid oxide catalyst comprising manganese oxide nanoparticles supported on mesoporous spinel cobalt oxide, which catalyses the conversion of carbon dioxide to methanol at high yields. In addition, carboncarbon bond formation is observed through the production of ethylene. We document the existence of an active interface between cobalt oxide surface layers and manganese oxide nanoparticles by using X-ray absorption spectroscopy and electron energy-loss spectroscopy in the scanning transmission electron microscopy mode. Through control experiments, we find that the catalyst's chemical nature and architecture are the key factors in enabling the enhanced methanol synthesis and ethylene production. To demonstrate the industrial applicability, the catalyst is also run under high conversion regimes, showing its potential as a substitute for current methanol synthesis technologies.open2

How do admission committees select? Do applicants know how they select? Selection Criteria and Transparency at a Dutch University.

In this study, we investigated the currently applied selective admission criteria and tools of the two-year research master’s programs of both the Graduate Schools of Life Sciences and Natural Sciences of Utrecht University (the Netherlands). In addition, we evaluated their transparency to applicants. Both admissions staff members and applicants participated. To determine admission criteria that are important for admission decisions, we ranked 51 admission criteria and, on their basis, combined into six domains: academic background, grades, cognitive ability, research background, personality and personal competencies, motivation factors. To evaluate transparency, we contrasted the perceptions of applicants with the actual importance of admission criteria, as reported by admission staff members. We found that admissions criteria related to personality and personal competencies are less important in admission decisions than criteria related to grades, academic background and motivation. The applicants find the admissions decisions transparent to a moderate degree. This study also revealed that selectors use criteria and tools both with and without predictive value for later graduate performance. Moreover, some of the currently applied admission instruments might be prone to admission biases. We advocate selectors to use admission criteria and tools that are evidence-based, resistant to admission biases, and transparent to the applicants

Southern Forests

Scorodophloeus fischeri (Fabaceae, subfamily Caesalpinoideae) and Manilkara sulcata (Sapotaceae) are examples of tropical African hardwood species and are endemic to East African coastal forests. These plant species are threatened by human activities beyond natural recovery in some forests. This study aimed to assess the effects of anthropogenic disturbance on the natural regeneration potential of S. fischeri and M. sulcata in the selected coastal forests of Tanzania. Transects were established in various vegetation communities and a nested quadrat technique was used to assess the natural regeneration. Scorodophloeus fischeri regenerates best in Zaraninge forest with high density of trees with diameter at breast height (DBH) between 10-50 cm and a higher seedling density than in other forests. Similarly, M. sulcata regenerates best in Pande forest, although many trees had a DBH of 10-30 cm, implying that the trees with size classes above these are missing. It was concluded that the minimum level of human disturbances in Zaraninge favoured high potentials of natural regeneration of S. fischeri. Disturbances through human activities contributed to the variation in the natural regeneration potentials for S. fischeri and M. sulcata in these forests. Conservation attention is likely to improve population structure and natural regeneration patterns of S. fischeri and M. sulcata in East African coastal forests

A mixed method study investigating the key translational competencies acquired during a challenge-based course

Background The translational domain is a complex subfield of the biomedical life sciences focused on bridging the gap between scientific research and clinical application, with the ultimate goal of improving patient care through healthcare innovations. Professionals in this field, ranging from researchers to clinicians and industry experts, require specific core competencies. These include communication, collaboration, boundary crossing, innovation, and the ability to integrate diverse scientific domains. Methods We investigated the translational competencies acquired most by life science students who participated in a six-month challenge-based course at a Dutch graduate school. Seventeen students were part of the 2021 cohort, supervised by five biomedical experts serving as their clients. Quantitative and qualitative student survey data (n = 10), and semi-structured expert interview data (n = 4) were collected after completion of the course in 2021. Two existing translational competency frameworks were used to categorize and rank the acquired competencies, highlighting those most developed and relevant during the translational challenge-based course. Results Communication was the most listed competency category by both students and experts, and a new competency category was identified named Self-Development Tools, which included competencies related to decision-making, reflection, feedback, and creative thinking. Student data also showed that the course influenced their choice in pursuing a translational career path. Conclusions This study provides insight into key translational competencies acquired by students during a six-month challenge-based course and insight into competencies that may be part of their continued education after graduation from both student and expert perspectives. These findings are relevant for both educators and prospective employers in the translational domain as they apply a novel ranking to the existing literature on translational competencies and elaborate on how to prepare life sciences graduates towards a translational career

One size does not fit all: an exploratory interview study on how translational researchers navigate the current academic reward system

Introduction: Translational research is a subfield of the biomedical life sciences that focuses on clinically driven healthcare innovations. The workforce of this subfield, i.e., translational researchers, are diversely specialized and collaborate with a multitude of stakeholders from diverse disciplines in and outside academia in order to navigate the complex path of translating unmet clinical needs into research questions and ultimately into advancements for patient care. Translational researchers have varying responsibilities in the clinical, educational, and research domains requiring them to split their time two- or three-ways. Working between these domains and alongside peers who do not split their time as such, raises questions about the academic reward system used to recognize their performance, which mainly focuses on publication metrics within the research domain. What is unclear is how combining research tasks with tasks in the clinical and/or educational domains effects translational researchers and how they navigate the academic reward system. Methods: In this exploratory interview study, semi-structured interviews were conducted to gain a deeper understanding of the current academic reward system for translational researchers. Stratified purposeful sampling was used to recruit 14 translational researchers from varying countries, subspecialties, and career stages. The interviews were coded after data collection was complete and arranged into three overarching result categories: intrinsic motivation, extrinsic factors, and ideal academic reward system and advice. Results: We found that these 14 translational researchers were intrinsically motivated to achieve their translational goals while working in settings where clinical work was reported to take priority over teaching which in turn took priority over time for research. However, it is the latter that was explained to be essential in the academic reward system which currently measures scientific impact largely based on publications metrics. Conclusion: In this study, translational researchers were asked about their thoughts regarding the current academic reward system. Participants shared possible structural improvements and ideas for specialized support on an individual, institutional, and also international level. Their recommendations focused on acknowledging all aspects of their work and led to the conclusion that traditional quantitative academic reward metrics do not fully align with their translational goals

Once the best student always the best student? Predicting graduate study success using undergraduate academic indicators: Evidence from research masters’ programs in the Netherlands

In the face of increasing and diversifying graduate application numbers, evidence-based selective admissions have become a pressing issue. By conducting multilevel regression analyses on institutional admissions data from a Dutch university, this study aims to determine the predictive value of undergraduate academic indicators for graduate study success on research masters’ programs in the life sciences. The results imply that in addition to undergraduate grade point average, undergraduate thesis grade is a valid predictor of graduate grade point average. To a small extent, the examined undergraduate academic indicators also predict graduate degree completion and time to degree. The results from this study can be used by admissions committees for evaluating and improving their current practices of graduate selective admissions

Outcomes After Liver Transplantation With Incidental Cholangiocarcinoma

Cholangiocarcinoma (CCA) is currently a contraindication to liver transplantation (LT) in the United Kingdom (UK). Incidental CCA occurs rarely in some patients undergoing LT. We report on retrospective outcomes of patients with incidental CCA from six UK LT centres. Cases were identified from pathology records. Data regarding tumour characteristics and post-transplant survival were collected. CCA was classified by TNM staging and anatomical location. 95 patients who underwent LT between 1988–2020 were identified. Median follow-up after LT was 2.1 years (14 days-18.6 years). Most patients were male (68.4%), median age at LT was 53 (IQR 46-62), and the majority had underlying PSC (61%). Overall median survival after LT was 4.4 years. Survival differed by tumour site: 1-, 3-, and 5-year estimated survival was 82.1%, 68.7%, and 57.1%, respectively, in intrahepatic CCA (n = 40) and 58.5%, 42.6%, and 30.2% in perihilar CCA (n = 42; p = 0.06). 1-, 3-, and 5-year estimated survival was 95.8%, 86.5%, and 80.6%, respectively, in pT1 tumours (28.2% of cohort), and 65.8%, 44.7%, and 31.1%, respectively, in pT2-4 (p = 0.018). Survival after LT for recipients with incidental CCA is inferior compared to usual outcomes for LT in the United Kingdom. LT for earlier stage CCA has similar survival to LT for hepatocellular cancer, and intrahepatic CCAs have better survival compared to perihilar CCAs. These observations may support LT for CCA in selected cases