Genetic Gain in Grain Yield Potential and Associated Traits of Sesame (Sesamum indicum L.)

A yield potential experiment was conducted with eleven sesame varieties developed by the then Ethiopian Lowland Oil Crops Research Program from 1960s to 2007 along with one local variety. The objectives were to understand the genetic gain made in grain yield potential and to assess changes produced on morphological traits associated with genetic yield potential improvement. The varieties were evaluated in a randomized complete block design (RCBD) with three replications in 2010 main cropping season under irrigation and rainfed conditions at Melka Werer Agricultural Research Center and Mieso experimental testing sites, respectively. The analysis of variance revealed significant differences among varieties for all investigated traits. The over all increase in grain yield of improved varieties over the local variety  was estimated to be 150.3 kg ha-1 (26.03%). Based on the regression analysis, the estimated average annual rate of increase in grain yield potential was 9.55 kg ha-1 year-1 with an annual relative genetic change of 1.24 % year-1. Harvest index and seed yield per plant showed significant and non significant increase with respective annual genetic gains of 3.00 and 0.57% respectively, while biomass yield, plant height, and number of capsules per plant showed insignificant decrease of 0.64, 0.10 and 0.17% per annum respectively. Days to flowering and days to maturity decreased non significantly by 0.33 and 0.26%, while seed growth rate and seed yield per day increased significantly by 1.35 and 1.74% per annum, respectively. Absence of plateau indicated the potential for further progress in grain yield in sesame. Correlation analysis indicated that grain yield was positively correlated with harvest index, plant height, seed yield per plant, number of capsule per plant, capsule length, thousand seed weight, seed growth rate and seed yield per day while, biomass yield, number of branches per plant, days to flowering, days to maturity and capsule filling period were negatively correlated with yield. The stepwise regression analysis showed that seed yield per plant greatly contributed to the variation among the varieties in grain yield. Improvement for high grain yield potential in sesame occurred over the past 47 years was ,due to grain yield improvement efforts. However, the improvement was also associated with paralleled increase in harvest index, plant height, seed yield per plant, number of capsule per plant, capsule length, thousand seed weight, seed growth rate and seed yield per day. Keywords: Ethiopia, Harvest index, Seed yield, Yield components, Yield gain

Genetic Variability and Character Association in Upland Rice (Oryza sativa L.) Genotypes, Southwestern Ethiopia

This study aimed to estimate the genetic variability of 36 upland rice genotypes for yield and its components, and determine trait association among morphological traits. The field experiment was conducted using simple lattice design at two locations (Guraferda and Gojeb) during 2016 main cropping season. Analysis of variance for individual locations revealed significant differences (P≤0.05) among genotypes for most of the studied traits at Guraferda, however number of fertile tillers per plant, number of unfilled grains per panicle, non-fertile tillers per plant, panicle length, thousand grain weight and biological yield were found being non-significant. Similarly, the genotypes showed significant difference (P≤0.05) for plant height, number of filled grain per panicle, days to maturity, number of primary branches per panicle and grain yield however the remaining traits were showed non-significant difference among genotypes at Gojeb. Combined analysis of variance over the two locations revealed significant differences (P≤0.05) among the genotypes for most of the studied traits, while genotype x location interactions showed significant differences for the traits, total number of tillers per plant, plant height, days to 50% heading, days to maturity and grain yield. The mean over the two locations showed, wide ranges for number of filled grains per panicle (24-123), days to 50% heading (50-83) and grain yield (15-34 q/ha). The genotypic coefficient of variation ranged from 2.3% for plant height to 19.5% for number of filled grains per panicle, and phenotypic coefficient of variation (PCV) ranged from 4.0% for panicle length to 20.2% for filled grains per panicle. High broad sense heritability (H2B) estimates were obtained for number of filled grains per panicle (93.3%) and days to 50% heading (61.6%); while low H2B value was found for plant height (20.1%), number of primary branches per panicle (15.1%) and grain yield (14.4%). The estimates of genetic advance as the percentage of the mean (GAM) ranged from 2.1% for plant height to 38.8% for number of filled grains per panicle. High H2B coupled with high GAM were obtained for number of filled grains per panicle, which indicates that this trait can be effectively improved through selection. Grain yield showed significant and positive genotypic correlation with 1000-grain weight, days to 50% heading, days to maturity and harvest index. Similarly, it showed significant and positive phenotypic correlation with panicle length, number of filled grains per panicle, 1000-grain weight, fertile tillers per plant and number of primary branches per panicle. Path coefficient analysis at genotypic level revealed high and positive direct effect of days to heading (0.7), 1000-grain weight (0.6), days to maturity (0.3) and harvest index (0.2). The detected positive correlation indicated that, increases in the value of one trait results in increasing the correlated traits. Keywords: Broad sense heritability, Upland rice, Variability, DOI: 10.7176/JBAH/9-3-0

Effects of Sowing Methods and Seed Rates on Yield Components and Yield of Tef in Soro Woreda, Hadya Zone, Southern Ethiopia

Tef [Eragrostis tef (Zucc.) Trotter] is among the major cereals of Ethiopia and occupies the largest cultivated land more than any other cereals. The need for its production as a staple food is increasing from year to year; however, its productivity is almost stagnant. Tef variety, Kuncho (Dz-Cr-387) was sown during the main cropping season of 2014/15 at First Oda Kebele, Soro District, Hadya Zone, Southern Ethiopia to study the effect of two types of sowing methods (broadcast and row) and three levels of seed rates (25, 20 and 10 kg/ha) and to investigate the interaction effect of sowing methods and seed rates on yield components and yield of tef. A factorial experiment was laid out in RCBD in three replications. All plant parameters were significantly affected by main effects of sowing methods and seed rates. Only two plant parameters (Days to 90 % PM and grain yield) were significantly affected by the interaction effect of sowing methods and seed rates. Sowing plants in rows increased plant height by 4.67cm over the broadcast sowing method. Similarly, there was significant increase in plant height by decreasing the seed rate from 25 kg/ha to 10 kg/ha.  There was 2.55 cm increase of panicle length observed on plants sown in rows as compared to plants sown in broadcast. In the same way, there was significant increase of panicle length by decreasing the seed rate from 25 kg/ha to 10 kg/ha. The highest days to 90 % physiological maturity was recorded by combining row sowing method with 20 kg/ha seed rate. There was 7 days delay of days to 90 % physiological maturity due to this combination as compared to the control treatment. Lodging was more in broadcast sowing than in row sowing. There was 7.78 percent more lodging observed in the treatments under broadcast sowing method as compared to treatments under row sowing method. It was not statistically different by using 25 kg/ha and 20 kg/ha seed rates but it was lower and significant at 10 kg/ha seed rate as compared to the first two seed rates. There was 15.7 % increase of grain yield of tef by combining the row sowing method with 10 kg/ha seed rate as compared to the control treatment.  There was more straw yield (327.8 kg/ha) obtained from treatments under row sowing method as compared to treatments under broadcast sowing method. Similarly, there was significant increase of straw yield by decreasing the seed rate from 25 kg/ha to 10 kg/ha. The higher biomass yield (6 %) was obtained from plants grown under row sowing as compared to plants grown under broadcast sowing. Correspondingly, there was biomass yield increment observed by decreasing the seed rate. In general, the combination of row sowing method with 10 kg/ha seed rate was the best treatment for high grain yield of tef at the study site. Yet, repeated experiment over different seasons and locations necessitates for conclusive recommendation. Keywords: Row sowing, Kuncho te

The geology and geochemistry of the north-eastern sector of Lyttelton volcano, Banks Peninsula, New Zealand.

Miocene volcanic activity constructed the Lyttelton composite cone 11 -10 Ma ago. The Lyttelton volcano which forms the north western half of Banks Peninsula represents a significant volume of mafic volcanic rocks together with some of felsic and minor intermediate composition. In addition to these, the volcano is characterized by pyroclastic deposits (lahars and lithic-crystal tuffs). Lyttelton lavas are intruded by numerous radial dikes and also by a variety of lava domes, sills and plugs. The volcanism was mainly Hawaiian in style, with some Vulcanian and occasional Strombolian styles of activity. Within this composite volcano, two major phase of volcanic activity are recognized. These are the main phase (the older) and late phase (younger) Lyttelton volcanics defined on the basis of field relationships, petrography and geochemistry. The late phase volcanics are designated formally as the Mt Pleasant Formation. The main and late phase Lyttelton volcanics range from mafic to felsic rocks compositions. The dikes range from basalt to trachyte and intruded the volcano during the main and late phase of volcanic activity. Sills and intrusions have felsic compositions. The major valleys and the lahar deposits represent periods of degradation of the active cone. Both the main and late phase (Mt Pleasant Formation) Lyttelton volcanics are alkaline tending transitional in geochemical affinity. The alkaline, sodic series Lyttelton rocks are members of the alkali olivine basalt association and this designation is consistent with mineralogy. Some intermediate and felsic Lyttelton rocks are subalkaline and potassic in composition, but they are classified as alkaline olivine basalt associations on the basis of their mineralogy. There are geochemical distinctions in major oxides, trace -elements and normative mineralogy between the main and late (Mt Pleasant Formation) Lyttelton rocks. The petrogenesis of the main and late Lyttelton volcanics mafic lavas is best explained by low pressure crystal fractionation of the observed phenocryst phases. The intermediate and felsic rocks are derived by similar processes with minor crustal contamination. Tectonically, Lyttelton volcanics represent “within plate” alkaline mafic volcanism

Dilatation of Lateral Ventricles with Brain Volumes in Infants with 3D Transfontanelle US

Ultrasound (US) can be used to assess brain development in newborns, as MRI is challenging due to immobilization issues, and may require sedation. Dilatation of the lateral ventricles in the brain is a risk factor for poorer neurodevelopment outcomes in infants. Hence, 3D US has the ability to assess the volume of the lateral ventricles similar to clinically standard MRI, but manual segmentation is time consuming. The objective of this study is to develop an approach quantifying the ratio of lateral ventricular dilatation with respect to total brain volume using 3D US, which can assess the severity of macrocephaly. Automatic segmentation of the lateral ventricles is achieved with a multi-atlas deformable registration approach using locally linear correlation metrics for US-MRI fusion, followed by a refinement step using deformable mesh models. Total brain volume is estimated using a 3D ellipsoid modeling approach. Validation was performed on a cohort of 12 infants, ranging from 2 to 8.5 months old, where 3D US and MRI were used to compare brain volumes and segmented lateral ventricles. Automatically extracted volumes from 3D US show a high correlation and no statistically significant difference when compared to ground truth measurements. Differences in volume ratios was 6.0 +/- 4.8% compared to MRI, while lateral ventricular segmentation yielded a mean Dice coefficient of 70.8 +/- 3.6% and a mean absolute distance (MAD) of 0.88 +/- 0.2mm, demonstrating the clinical benefit of this tool in paediatric ultrasound

Regulation of protein and carbohydrate intake in caged honeybees Apis mellifera scutellata : assessment based on consumption and various performance measures

When provided with the opportunity to select their diet, most insect herbivores regulate their nutrient intake. However, in a nutritionally heterogeneous environment and with changing demands for growth, development and reproduction, obtaining the required amount and balance of nutrients is a challenge. This is especially true for social insects where the workers bring food into the colony to be shared by nestmates. The ability of insects to self-select their diet is an important trait related to fitness. In this study we investigated whether and how caged worker honeybees meet their nutritional requirements in response to the nutritional composition of the food they find. Using the ‘geometric framework’ we looked at the behavioural and physiological mechanisms used by caged worker honeybees in balancing their diet when provided with different pairs of complementary imbalanced foods. First, we investigated whether caged worker honeybees maintain their intake target by providing them with pairs of complementary imbalanced foods with varying protein to carbohydrate (P:C) ratios. Diets were formulated using different protein sources: casein, royal jelly and Feed-Bee®. Honeybees self-selected or balanced their diet by switching between the complementary foods in accordance with the composition of the food and the type of protein that they encountered. Honeybees selected average P:C ratios of 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee® diets respectively. The level of self-selection was confirmed using two performance measures: survival and ovarian activation. Both survival and ovarian activation differed depending on the type of protein source used. Second, we investigated if honeybees regulated their growth target, which is the amount of nutrients incorporated into growth and storage tissue, by measuring physiological parameters in honeybees confined on imbalanced complementary food combinations having different P:C ratios. Feed-Bee® was used as a protein source. The physiological parameters measured were head fresh mass, hypopharyngeal gland (HPG) development, and protein concentration in the haemolymph. The bees fed on different diet combinations with different P:C ratios maintained each of the performance measures to the same level, which supports the ability of worker honeybees to self-select their diet. The measured physiological parameters were compared with other studies to asses the appropriateness Feed-Bee® diet as a protein source for the bees. In the absence of brood the intake target is directly related to the physiological requirements of the worker bees. The behavior of these individual adult bees gives an insight in to the complex system; similar responses may be seen in nurse bees in the colony condition to obtain protein, carbohydrate and other nutrient requirements from stored pollen and nectar in the hive, either for their own nutritional requirements or for other colony members, especially larvae.Dissertation (MScAgric)--University of Pretoria, 2010.Zoology and Entomologyunrestricte

Guidelines to improve antibiotic prescribing practice at primary healthcare facilities in Ethiopia

Background Antibiotics are the most frequently used medicines in healthcare facilities. Since their discovery, they have played a pivotal role in combating infectious diseases and maintaining health, especially in developing countries where such diseases still remain as a big challenge. In recent years, however, the benefits derived from antibiotic use are facing great challenges due to the emergence of resistance where many bacteria have become resistant to the most commonly used first-line antibiotics. The major driver of antimicrobial resistance is known to be the huge increase in antibiotic prescribing, especially in low- and middle-income countries. Studies conducted on the rate of antibiotic resistance in Ethiopia have shown that the majority of bacteria that cause infections have developed a considerable degree of resistance to commonly used first-line antibiotics. In this country, antibiotics are prescribed at a far higher rate than the optimal value recommended by the World Health Organization. This exposes the available antibiotics to the risk of resistance. Purpose The purpose of this study was to describe the rate and patterns of antibiotic prescribing, explore the factors that affect the decisions to prescribe antibiotics, and identify interventions that should be implemented with a view to developing evidence- based and theory-informed intervention guidelines to improve antibiotic prescribing at primary healthcare facilities in Ethiopia. Methods Guided by the PRECEDE-PROCEED Model, the study was conducted using an explanatory sequential mixed method approach. In the first phase of the study (quantitative), data was collected from 2 000 prescriptions and patient medical charts sampled from ten randomly selected, public health centres situated in five of the sub cities in Addis Ababa City Administration. The second phase of the study (qualitative) was undertaken through in-depth interview of 20 prescribers from five of the health centres, as well as with 22 key informants from the five health centres, five sub-city health offices and the Health Bureau. The quantitative data was analysed using SPSS version 28. Thematic content analysis supported by ATLAS.ti 9 was used to analyse the qualitative data. Intervention guidelines to improve antibiotic prescribing were then developed by integrating findings of the qualitative and quantitative studies. Results The average number of medicines per prescription was 1.87 ranging from 1.71 to 2.11 among the health centres. The percentage of prescriptions containing one or more antibiotic was 52.5%, with wide variation (41.5% to 61.5%) among the health centres included in the study. The rate of antibiotic prescribing was shown to have a statistically significant correlation with the patient’s age, the qualification of the prescriber and the season of prescribing. Amoxicillin, ciprofloxacin, cloxacillin, doxycycline and cotrimoxazole accounted for nearly 80% of the antibiotics prescribed, with amoxicillin (41.2%), ciprofloxacin (14.1%) and cloxacillin (9.6) being the top three most commonly prescribed. About 56% of the prescribed antibiotics belong to the Penicillins category and majority (92.7%) of the antibiotics were prescribed for oral administration. Nearly 77% belong to the Access category and the remaining 23% to the Watch category of the World Health Organization’s Access, Watch and Reserve Classification of antibiotics. Upper respiratory tract infection (21.7%), urinary tract infections (13.1%) and topical infections – skin, eye and ear (9.7%) were the most common diagnoses for prescribing the antibiotics. About 37.3% of the cases for prescribing of antibiotics were respiratory tract infections, the majority (90.7%) being for upper respiratory tract infections. Of those prescribed for respiratory tract cases, 51.6% were found appropriate and 34.9% inappropriate. The types of inappropriate antibiotic therapy included unnecessary antibiotic use (53%); high dose (16%); need for additional antibiotic (14%); not choosing the right antibiotic (11%); and low dose (6%). Cost wise, antibiotics accounted for 36.2% of the total cost of medicines prescribed, with the majority of that being for amoxicillin (39.8%), cloxacillin (15.7%) and ciprofloxacin (10.3%). Five of them (amoxicillin, cloxacillin, ciprofloxacin, amoxicillin/clavulanic acid and cotrimoxazole) accounted for about 81% of the total cost of antibiotics prescribed. Antibiotics prescribed for all kinds of upper respiratory tract cases accounted for over one-third of the total cost of antibiotics prescribed. There were various kinds of problems with the prescription of antibiotics and their use at health centres, including the repeated use of antibiotics for the same diagnosis; use of antibiotics for minor problems; using high level antibiotics; discontinuing medication; and self-medication with antibiotics. The decision of healthcare providers to prescribe antibiotics is influenced by various predisposing, enabling and reinforcing factors. The factors are related with prescribers, patients and the health system, including gaps in the knowledge of health professionals on the use of antibiotics and resistance, low awareness of patients and the public on antimicrobial resistance, shortage of antibiotics and laboratory reagents, lack of updated information on the national and local antibiotic resistance pattern, patient pressure, patient load, excessive antibiotic prescribing at private health facilities, and the dispensing of antibiotics without prescription at private pharmacies. Though not as such heavily focused on antibiotics and resistance, various initiatives have been implemented at health centres that could contribute to improving the prescription of antibiotics and their use. Various interventions have been identified based on which intervention guidelines are developed to improve antibiotic prescribing at primary healthcare facilities. Challenges that might be faced when implementing these proposed interventions include shortage of personnel; financial constraints; resistance to change from professionals; shortage of medicines and laboratory reagents; inadequate government commitment; and resistance from the private sector because of the profit-motive. Conclusion There is high rate of antibiotic prescribing at health centres that far exceeds the recommended rate for primary healthcare facilities. The majority of antibiotics were prescribed for upper respiratory tract infections which are known to be mostly viral origin. Most of the antibiotics prescribed belong to the Access group of the World Health Organization’s Access, Watch and Reserve Classification. Antibiotics accounted for over one-third of the cost of medicines prescribed. Despite prescribers and key informants being aware of antibiotic resistance, its causes and consequences, there are still various types of antibiotic prescribing problems at health centres. The prescribing decisions of healthcare providers are influenced by several factors that are categorised as predisposing, enabling or reinforcing factors. Intervention guidelines that will be used to improve the prescribing of antibiotics at health centres were developed based on the interventions suggested by the study participants. urther studies on medicine use are required to appropriately understand the rate and patterns of antibiotic prescribing, and prescribers’ adherence to the new Primary Healthcare Clinical guidelines in managing commonly encountered cases such as upper respiratory tract infections at primary healthcare facilities. Research should be undertaken to evaluate the effectiveness of the intervention guidelines developed following PRECEED component (implementation, and monitoring and evaluation phases) of the PRECEDE-PROCEED Model that guided this study. The piloting and implementation of the guidelines requires the active involvement of all stakeholders under the leadership of Ministry of Health and the Health Bureau. The anticipated challenges need to be taken into consideration in implementing the interventions.Health StudiesD.Phil. (Public Health

The Transition to Middle School is Associated with Changes in the Developmental Trajectory of ADHD Symptomatology in Young Adolescents with ADHD

The attention deficit hyperactivity disorder (ADHD) symptom presentation of young adolescents with ADHD was examined in association with the transition to middle school. This study used data collected in the Multimodal Treatment Study of ADHD, which included children between 7 and 9 years of age with a diagnosis of ADHD (n=258) and grade- and sex-matched controls (n=112). The trajectory of ADHD symptoms before, during, and after the transition to middle school was modeled using hierarchical linear modeling. A clear developmental reduction in ADHD symptomatology was observed for all three ADHD symptom domains. For young adolescents with ADHD, the transition to middle school was associated with a disruption in the developmental decline of inattention, hyperactivity, and impulsivity symptoms as measured by parent ratings. This effect was also observed for teacher ratings of inattention and hyperactivity. These results support the assertion that the environmental changes associated with transitioning to middle school coincide with a transient reversal in ADHD symptom decline among children with ADHD

Sex differences in white matter development during adolescence: A DTI study

Adolescence is a complex transitional period in human development, composing physical maturation, cognitive and social behavioral changes. The objective of this study is to investigate sex differences in white matter development and the associations between intelligence and white matter microstructure in the adolescent brain using diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS). In a cohort of 16 typically-developing adolescents aged 13 to 17 years, longitudinal DTI data were recorded from each subject at two time points that were one year apart. We used TBSS to analyze the diffusion indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Our results suggest that boys (13–18 years) continued to demonstrate white matter maturation, whereas girls appeared to reach mature levels earlier. In addition, we identified significant positive correlations between FA and full-scale intelligence quotient (IQ) in the right inferior fronto-occipital fasciculus when both sexes were looked at together. Only girls showed significant positive correlations between FA and verbal IQ in the left cortico-spinal tract and superior longitudinal fasciculus. The preliminary evidence presented in this study supports that boys and girls have different developmental trajectories in white matter microstructure

A Roadmap for Building Data Science Capacity for Health Discovery and Innovation in Africa

Technological advances now make it possible to generate diverse, complex and varying sizes of data in a wide range of applications from business to engineering to medicine. In the health sciences, in particular, data are being produced at an unprecedented rate across the full spectrum of scientific inquiry spanning basic biology, clinical medicine, public health and health care systems. Leveraging these data can accelerate scientific advances, health discovery and innovations. However, data are just the raw material required to generate new knowledge, not knowledge on its own, as a pile of bricks would not be mistaken for a building. In order to solve complex scientific problems, appropriate methods, tools and technologies must be integrated with domain knowledge expertise to generate and analyze big data. This integrated interdisciplinary approach is what has become to be widely known as data science. Although the discipline of data science has been rapidly evolving over the past couple of decades in resource-rich countries, the situation is bleak in resource-limited settings such as most countries in Africa primarily due to lack of well-trained data scientists. In this paper, we highlight a roadmap for building capacity in health data science in Africa to help spur health discovery and innovation, and propose a sustainable potential solution consisting of three key activities: a graduate-level training, faculty development, and stakeholder engagement. We also outline potential challenges and mitigating strategies