Angle Cleat Base Connections

Tests, performed on base connections fabricated from cold-formed channels and hot-rolled angle cleats, are presented in this paper. This research is part of an on- going research to develop portal frames made out of cold-formed steel. The base connections are subjected to an axial load and moment. Hot-rolled angle cleats are used to prevent premature failing of the base connections. Several loading configurations are considered and these are dependent on the eccentricity of the load. In all the tests the cold-formed channels failed by local buckling. A significant amount of bearing distortion was observed in the heavily loaded flange. The use of bolted angle cleats a llows for a simple connection to be developed, which can result in significant cost savings within the steel construction industry

Significance of sweet sorghum as a multi-purpose crop for sub-Saharan Africa

There is great interest in sweet sorghum (Sorghum bicolor L.) for promoting resilience in rural livelihoods in Sub- Saharan Africa (SSA). Unlike other crops, sweet sorghum is a multi-purpose crop for grain, feed, fodder, chewing, syrup and biofuel production. The objective of this paper is to analyse information on the diversity within the crop, its adaptation and plant breeding efforts in SSA. We also discuss opportunities that exist in SSA that make the crop an attractive alternative. It is clear from the review that the crop has a wide genetic base, hence significant improvements can be made on a number of preferred traits. The review further outlines four possible production models for the economic development of the sweet sorghum industry in Sub-Saharan Africa; which are (i) production for supply to urban chewing markets, (ii) syrup production, (iii) biofuel production and (iv) fodder production. Although current research focuses on production of ethanol for biofuel, other potential uses such as production for chewing, syrup and fodder cannot be overlooked for most SSA farmers. A lot has to be done on the research front before biofuel production from sweet sorghum can be profitable and technically feasible. Future plant breeding efforts can be tailor made to deliver cultivars with peculiar traits for various end-uses

SIGNIFICANCE OF SWEET SORGHUM AS A MULTI-PURPOSE CROP FOR SUB-SAHARAN AFRICA

There is great interest in sweet sorghum ( Sorghum bicolor L.) for promoting resilience in rural livelihoods in Sub- Saharan Africa (SSA). Unlike other crops, sweet sorghum is a multi-purpose crop for grain, feed, fodder, chewing, syrup and biofuel production. The objective of this paper is to analyse information on the diversity within the crop, its adaptation and plant breeding efforts in SSA. We also discuss opportunities that exist in SSA that make the crop an attractive alternative. It is clear from the review that the crop has a wide genetic base, hence significant improvements can be made on a number of preferred traits. The review further outlines four possible production models for the economic development of the sweet sorghum industry in Sub-Saharan Africa; which are (i) production for supply to urban chewing markets, (ii) syrup production, (iii) biofuel production and (iv) fodder production. Although current research focuses on production of ethanol for biofuel, other potential uses such as production for chewing, syrup and fodder cannot be overlooked for most SSA farmers. A lot has to be done on the research front before biofuel production from sweet sorghum can be profitable and technically feasible. Future plant breeding efforts can be tailor made to deliver cultivars with peculiar traits for various end-uses.Il existe un grand int\ue9r\ueat pour le sorgho doux (Sorghum bicolor L.) pour promouvoir la r\ue9silience des moyens de subsistance ruraux en Afrique subsaharienne (ASS). Contrairement \ue0 d\u2019autres cultures, le sorgho sucr\ue9 est une culture polyvalente pour la production de c\ue9r\ue9ales, d\u2019aliments pour animaux, de fourrage, de mastication, de sirop et de biocarburant. L\u2019objectif de cet article est d\u2019examiner les informations sur la diversit\ue9 au sein de la culture, son adaptation et les efforts de s\ue9lection v\ue9g\ue9tale en ASS. Il traite \ue9galement des opportunit\ue9s qui existent en ASS et qui font de cette culture une alternative attrayante. Les r\ue9sultats de l\u2019examen montrent que la culture a une large base g\ue9n\ue9tique, ce qui permet d\u2019apporter des am\ue9liorations significatives \ue0 un certain nombre de caract\ue8res pr\ue9f\ue9r\ue9s. L\u2019examen d\ue9crit en outre quatre mod\ue8les de production possibles pour le d\ue9veloppement \ue9conomique de l\u2019industrie du sorgho sucr\ue9 en Afrique subsaharienne\ua0; qui sont (i) la production pour l\u2019approvisionnement des march\ue9s urbains de mastication, (ii) la production de sirop, (iii) la production de biocarburants et (iv) la production de fourrage. Les questions cl\ue9s \ue9mergeant de la discussion sont les suivantes\ua0; la recherche actuelle se concentre sur la production d\u2019\ue9thanol pour le biocarburant, bien que ce soit une bonne priorit\ue9 pour la recherche, cela ne devrait pas \ue9clipser d\u2019autres utilisations potentielles de la culture telles que la production pour la mastication, le sirop et le fourrage qui peuvent \ueatre la seule option pour la plupart des agriculteurs d\u2019ASS. Beaucoup reste \ue0 faire sur le front de la recherche avant que la production de biocarburants \ue0 partir de sorgho sucr\ue9 puisse \ueatre rentable et techniquement r\ue9alisable, en particulier pour les petits exploitants agricoles dans la plupart des pays d\u2019ASS. Par cons\ue9quent, les futurs efforts de s\ue9lection v\ue9g\ue9tale peuvent \ueatre adapt\ue9s pour fournir des cultivars avec des traits particuliers pour diverses utilisations finales

Evaluation of carcass performance of Matebele goats managed extensively based on the eruption of permanent incisors teeth

Matebele goats were slaughtered at different state of permanent incisors eruption 1st pair (I1 )(237records), 2nd pair (I2 )(312 records), 3rd pair (I3 )(237records), 4th pair (I4)(232 ), Broken Mouth (BM)(214) and Smooth Mouth (SM)(218) over a period of 15 years (1989- 2004) and analysed for carcass performance. Performance parameters and weight of organs as a percentage of empty body weight (EBW) containing the effects of number of permanent incisors at I1, I2, I3, I4,, BM and SM were analysed using the General Linear Models. Live weight averaged 21.57 kg ± 0.02, 27.01± 0.02 kg, 28.40± 0.02 kg, 28.88± 0.02 kg, 36.92± 0.02 kg and 37.33± 0.02 kg for goats slaughtered at I1, I2, I3, I4,,, BM and SM, respectively. There was a significant (p<0.01) difference in slaughter weight at different periods of permanent incisors teeth eruptions. The goats slaughtered at I1 and I2 had significantly heavier hot carcass mass,cold carcass mass and rib barrel than those slaughtered I3, I4,, BM and SM. The goats slaughtered at I3 had the highest dressing percentage and goats slaughtered at BM had the lowest dressing percentage (DP). For external noncarcass components, the proportion of the head did not change but it was the feet proportion that increased markedly from I1 to I3 which coincided with the decrease in pelt. The proportion of hind barrel, head and kidney fat seemed to be constant. There was a significant (p< 0.01) difference between mesenteric fat amongst teeth groups, which increased with increasing number of permanent incisors eruption representing age increase. The lower proportion of noncarcass components in I3 may have contributed to a higher DP

Student Performance Patterns in Engineering at the University of Johannesburg: An Exploratory Data Analysis

Globally, the increased demand for engineers is not matched by an increase in graduates. This is further exacerbated by the fact that student dropout rates in engineering are higher than in other disciplines. Understanding engineering students’ performance patterns and potential influences can lead to developing interventions to improve engineering students’ success. Recent advances in data science and educational data mining have made it possible to extract valuable information from historical data, which can supplement interventions. This study sought to extract insights and information from real-world data, analyse correlations in the dataset’s variables and better understand the influences of student performance. Exploratory data analysis was applied to the dataset to visualise the dataset and infer the correlations between variables provided in the dataset on student performance patterns. We used Python for data analysis and visualising the correlation between variables. The results show gender disparity in engineering enrollments, with only a quarter of female students enrolled. The study also indicates that the completion rates could be much higher. Another finding is that most students who drop out do so because of choosing the wrong qualifications. Furthermore, when comparing the percentages, female students performed slightly better than their male counterparts. The correlation analysis shows no relationships between gender, race, admission point score, mathematics marks and science marks with student performance in engineering. Understanding student performance patterns can reduce dropout rates by correctly advising students to enrol on the most suitable programmes, and aid support interventions are needed to improve student success in engineering

Seed vigour tests for predicting field emergence of selected crops in Zimbabwe

Seed vigour testing provides valuable information for assessing seed lot quality, under less than optimum or diverse growing conditions, similar to those which occur in the field. A study was done to evaluate the effectiveness of vigour tests in distinguishing seedlots using cold test (CT), heat shock stress test (HSST), accelerated ageing test (AAT) and standard germination test (SGT) to predict field emergence of various crops, with farmer retained seed used as a control for all the crops. Analysis of variance revealed that the twelve genotypes (ZM401, SC403, local maize landrace, Macia, SV4, local sorghum landrace, Okashana, PMV3, local pearlmillet landrace, CBC 2, IT18 and local cowpea landrace) and five vigour test methods showed a significant difference (P<0.05) for germination percentage and days to 50% germination. There were significant interactions between crops 7 vigour tests and variety 7 vigour tests, indicating a differential performance of the vigour test in all the crops and varieties evaluated. This suggests that out of the vigour test methods evaluated, no single method can be used in isolation to accurately predict field emergence in the crops and varieties under study.Les tests de vigueur des semences fournissent des informations pr\ue9cieuses pour \ue9valuer la qualit\ue9 des lots de semences, dans des conditions de croissance moins qu\u2019optimales ou diverses, similaires \ue0 celles qui se produisent sur le terrain. Une \ue9tude a \ue9t\ue9 r\ue9alis\ue9e pour \ue9valuer l\u2019efficacit\ue9 des tests de vigueur dans la distinction des lots de semences \ue0 l\u2019aide d\u2019un test \ue0 froid (CT), d\u2019un test de stress par choc thermique (HSST), d\u2019un test de vieillissement acc\ue9l\ue9r\ue9 (AAT) et d\u2019un test de germination standard (SGT) pour pr\ue9dire l\u2019\ue9mergence au champ de diverses cultures, avec l\u2019agriculteur a conserv\ue9 les semences utilis\ue9es comme contr\uf4le pour toutes les cultures. L\u2019analyse de la variance a r\ue9v\ue9l\ue9 que les douze g\ue9notypes (ZM401, SC403, race locale de ma\uefs local, Macia, SV4, race locale de sorgho, Okashana, PMV3, race locale de filet de perle, CBC 2, IT18 et race locale de ni\ue9b\ue9) et cinq m\ue9thodes de test de vigueur ont montr\ue9 une importante diff\ue9rence (P <0,05) pour le pourcentage de germination et les jours jusqu\u2019\ue0 50% de germination. Il y avait des interactions significatives entre les cultures 7 tests de vigueur et les tests vari\ue9t\ue9 7 vigueur, indiquant une performance diff\ue9rentielle du test de vigueur dans toutes les cultures et vari\ue9t\ue9s \ue9valu\ue9es. Cela sugg\ue8re que parmi les m\ue9thodes d\u2019essai de vigueur \ue9valu\ue9es, aucune m\ue9thode ne peut \ueatre utilis\ue9e isol\ue9ment pour pr\ue9dire avec pr\ue9cision l\u2019\ue9mergence au champ dans les cultures et les vari\ue9t\ue9s \ue9tudi\ue9es

Effect of priming regimes on seed germination of field crops

Germination, early emergence and stand establishment of crops are major yield determining factors in semi-arid and arid rainfed areas. Farmers in marginal and low input areas tend to have poor germination due to poor and shallow soils. The objective of this study was to evaluate the effect of priming regimes on seed germination of field crops. A study was conducted at Lupane State University, Biotechnology Laboratory in 2019. Treatments included seed priming techniques, namely hydropriming, halopriming (2% NaCl solution) osmopriming (10% PEG 6000), and solid matrix priming (18% volume/weight sand); and timing at 6, 12, 24 hours for maize and 2, 4, 6 hours for cowpea, sorghum and millet. Solid matrix priming, followed by hydropriming significantly (P<0.05) improved germination parameters (germination percentage, daily germination, peak value and germination speed) of all crops. Halopriming and osmopriming were similar in their ineffectiveness, and resulted in the least germination parameter values. Six hour solid matrix priming in 18% v/w sand was the most effective method among most crops; suggesting that solid matrix priming is an effective and possibly low cost technology, with potential to improve germination of field crops.La germination, l\u2019\ue9mergence pr\ue9coce et l\u2019\ue9tablissement des peuplements sont des facteurs d\ue9terminants du rendement dans les zones pluviales semi-arides et arides. Les agriculteurs des zones marginales et \ue0 faible apport ont tendance \ue0 avoir une mauvaise germination en raison de sols pauvres et peu profonds. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer l\u2019effet des r\ue9gimes d\u2019amor\ue7age sur la germination des semences des cultures de champs. Une \ue9tude a \ue9t\ue9 faite \ue0 Lupane State University, laboratoire de biotechnologie en 2019. Les traitements comprenaient des techniques d\u2019amor\ue7age des semences, \ue0 savoir l\u2019hydroprimage, l\u2019halopriming (solution \ue0 2% de NaCl), l\u2019osmopriming (10% PEG 6000) et l\u2019amor\ue7age \ue0 matrice solide (18% volume / poids de sable) ; et chronom\ue9trage \ue0 6, 12, 24 heures pour le ma\uefs et 2, 4, 6 heures pour le ni\ue9b\ue9, le sorgho et le mil. L\u2019amor\ue7age de la matrice solide, suivi de l\u2019hydropriming, a significativement am\ue9lior\ue9 (P <0,05) les param\ue8tres de germination (pourcentage de germination, germination quotidienne, valeur maximale et vitesse de germination) de toutes les cultures. L\u2019halopriming et l\u2019osmopriming \ue9taient similaires dans leur inefficacit\ue9 et ont donn\ue9 les valeurs de param\ue8tres de germination les moins \ue9lev\ue9es. L\u2019amor\ue7age de la matrice solide sur six heures dans du sable \ue0 18% v / w \ue9tait la m\ue9thode la plus efficace parmi la plupart des cultures; sugg\ue9rant que l\u2019amor\ue7age \ue0 matrice solide est une technologie efficace et peut-\ueatre \ue0 faible co\ufbt, avec un potentiel pour am\ue9liorer la germination des cultures de champs

Tomato breeding in sub-Saharan Africa - Challenges and opportunities: A review

Successful tomato ( Solanum lycopersicum ) production depends on availability of improved cultivars that can withstand biotic and abiotic pressures inflicted by the environment. This paper explores the challenges in tomato breeding and identifies opportunities that can be explored to improve tomato breeding initiatives in Africa. The review focuses on primary sources of information and notes that few existing tomato breeding institutions in Africa can drive a vibrant tomato industry and its downstream enterprises. This is coupled with inadequate breeding policies regarding varietal release and protection, negative effects of climate change, emergence of pests and diseases that impact negatively on tomato production efforts in Africa. There is a chance to tap in the diversity currently existing in wild tomato relatives, and to introduce and strengthen tomato breeding at various research institutes, through capacity building. Furthermore, there is need for Africa to embrace long term breeding strategies such as pre-breeding and the use of modern breeding technologies, if tomato production is to be sustained. Key production challenges in Africa include high incidences of fungal diseases and pests, low soil fertility, limited tomato breeding, climate change induced stresses and lack of adequate inputs due to prohibitive costs. Tomato production opportunities arise as a result of increase in human populations and consequently mounting consumer demands for nutrition and potential use of improved technologies such as CRISPR and gene sequence technologies to produce novel genotypes.La r\ue9ussite de la production de tomates ( Solanum lycopersicum ) d\ue9pend de la disponibilit\ue9 de cultivars am\ue9lior\ue9s qui peuvent r\ue9sister aux pressions biotiques et abiotiques inflig\ue9es par l\u2019environnement. Cet article scientifique explore les d\ue9fis de la s\ue9lection des tomates et identifie les opportunit\ue9s qui peuvent \ueatre explor\ue9es pour am\ue9liorer les initiatives de s\ue9lection des tomates en Afrique. La revue scientifique se concentre sur les principales sources d\u2019information et note que peu d\u2019institutions de s\ue9lection de tomates en Afrique peuvent stimuler une industrie de la tomate dynamique et ses entreprises en aval. Ceci est coupl\ue9 \ue0 des politiques de s\ue9lection inad\ue9quates concernant la lib\ue9ration et la protection vari\ue9tales, les effets n\ue9gatifs du changement climatique, l\u2019\ue9mergence de ravageurs et de maladies qui ont un impact n\ue9gatif sur les efforts de production de tomates en Afrique. Il est possible d\u2019exploiter la diversit\ue9 qui existe actuellement chez les parents de tomates sauvages et d\u2019introduire et de renforcer la s\ue9lection des tomates dans divers instituts de recherche, gr\ue2ce au renforcement des capacit\ue9s. En outre, l\u2019Afrique doit adopter des strat\ue9gies de s\ue9lection \ue0 long terme telles que la pr\ue9-s\ue9lection et l\u2019utilisation de technologies de s\ue9lection modernes, si la production de tomates doit \ueatre maintenue. Les principaux d\ue9fis de production en Afrique comprennent une incidence \ue9lev\ue9e de maladies fongiques et de ravageurs, une faible fertilit\ue9 des sols, une reproduction limit\ue9e des tomates, des stress induits par le changement climatique et le manque d\u2019intrants ad\ue9quats en raison de co\ufbts prohibitifs. Les opportunit\ue9s de production de tomates r\ue9sultent de l\u2019augmentation des populations humaines et par cons\ue9quent de la demande croissante des consommateurs pour la nutrition et l\u2019utilisation potentielle de technologies am\ue9lior\ue9es telles que CRISPR et les technologies de s\ue9quence de g\ue8nes pour produire de nouveaux g\ue9notypes

Genetic basis and the current breeding efforts for quality protein maize in Southern Africa

Maize ( Zea mays L.) is deficient in essential amino acids, lysine and tryptophan. Opaque-2 maize mutant discovery that is high in lysine and tryptophan, offers an avenue for maize protein quality improvement. Quality protein maize (QPM), a product of the extensive development of the Opaque-2 mutant, is an affordable and viable option for overcoming the scourge of protein malnutrition in humans and monogastric livestock especially in sub-Saharan Africa. The objective of this review was to scrutinise the genetic basis of quality protein maize (QPM), and current breeding efforts, and propose potential uptake pathways for QPM products in southern Africa. The conventional QPM breeding methods are based on phenotypic selection to identify genotypes carrying the recessive Opaque-2 alleles. However, phenotypic selection is negatively influenced by the environment and has huge drain on resources such as time, money and labour, with low genetic gains. From this, marker assisted breeding methods are clearly the most efficient way of QPM breeding. Institutions such as the International Maize and Wheat Improvement Centre (CIMMYT) are currently employing molecular breeding in QPM breeding programmes so as to quicken and ease the process of QPM breeding. To date, a number of QPM varieties have been released and are being promoted using various pathways and policies.Le Ma\uefs ( Zea mays L.) est d\ue9ficient en acides amin\ue9s essentiels, lysine et tryptophane. La d\ue9couverte du ma\uefs mutant Opaque-2 qui a un taux \ue9lev\ue9 en lysine et tryptophane, offre une voie pour une am\ue9lioration de la qualit\ue9 de prot\ue9ine dans le ma\uefs. Le ma\uefs \ue0 haute teneur prot\ue9ique (QPM), un produit du d\ue9veloppement extensif du mutant Opaque-2, est une option \ue9conomique et viable pour r\ue9duire le taux de malnutrition prot\ue9ique chez les humains et les animaux monogastriques sp\ue9cialement en Afrique sub-saharienne. L\u2019objectif de cette revue \ue9tait d\u2019examiner la base g\ue9n\ue9tique du ma\uefs \ue0 haute teneur prot\ue9ique (QPM), et les efforts r\ue9cents d\u2019am\ue9lioration g\ue9n\ue9tique, et de proposer un moyen d\u2019adoption des produits QPM en Afrique du Sud. Les m\ue9thodes conventionnelles d\u2019am\ue9lioration pour QPM sont bas\ue9es sur la s\ue9lection ph\ue9notypique pour identifier les g\ue9notypes portant les all\ue8les r\ue9cessifs d\u2019Opaque-2. Cependant, la s\ue9lection ph\ue9notypique est n\ue9gativement influenc\ue9e par l\u2019environnement et n\ue9cessite assez de ressources telles que le temps, argent et la main d\u2019\u153uvre, avec moins de gain g\ue9n\ue9tique. De l\ue0, les m\ue9thodes de s\ue9lection assist\ue9e par les marqueurs sont clairement les moyens les plus efficients pour la s\ue9lection pour QPM. Les institutions telles que le Centre International l\u2019Am\ue9lioration du Ma\uefs et du Bl\ue9 (CIMMYT) sont actuellement entrain d\u2019employer la s\ue9lection mol\ue9culaire dans les programmes d\u2019am\ue9lioration pour QPM de fa\ue7on \ue0 acc\ue9l\ue9rer et faciliter le processus d\u2019am\ue9lioration pour QPM. Au jour d\u2019aujourd\u2019hui, un certain nombre de vari\ue9t\ue9s QPM ont \ue9t\ue9 livr\ue9es et sont en cours d\u2019\ueatre promues en utilisant diff\ue9rents chemins et politiques