Surface spin dynamics of antiferromagnetically coupled frustrated triangular films

Results are presented for spin-wave dispersions in geometrically frustrated stacked triangular antiferromagnets with a thin film or semi-infinite geometry having either zero, easy-plane, or easy-axis anisotropy. Surface effects on the equilibrium spin configurations and excitation spectrum are investigated for the case of antiferromagnetically coupled films, serving to extend previous results on ferromagnetically coupled layers [E. Meloche et al., Phys. Rev. B 74, 094424 (2006)]. An operator equation of motion formalism is applied to systems which are quasi-one and quasi-two dimensional in character. In contrast to the case of ferromagnetically coupled films the new results show surface modes that are well separated in frequency from bulk excitations. Magnetic excitations in thin films with an even or an odd number of layers show qualitatively different behavior. These results are relevant for a wide variety of stacked triangular antiferromagnetics materials.Comment: 24 pages, 9 figure

EFFECTS OF STORAGE METHODS AND MYCOFLORA ON PROXIMATE COMPOSITION OF AFRICAN YAM BEAN (Sphenostylis stenocarpa Hochust ex Rich ) SEEDS

One of the limitations of African yam bean (AYB) (Sphenostylis sternocarpa) is poor storage ability due to the adverse effect of seed-borne fungi. This study was conducted to examine the effects of storage methods on nutritive composition of AYB  seeds stored in three types of storage materials viz; jute bags, polypropylene bags and plastic bowls. Freshly harvested AYB seeds were stored in all the storage materials for 6 months using 2 × 3 factorial (2 AYB cultivars and 3 storage methods) in 3 replicates. The proximate analysis of the stored AYB seeds was carried out at 3 and 6 months after storage using standard methods. The temperature and relative humidity of the store room were recorded monthly. Seeds stored in jute bags gave the best values for crude protein (24.87%), ash (5.69%) and fat content (6.64%) but recorded least values for crude fibre (2.55%), carbohydrate (50.86%) and moisture content (12.68%) at the 6th month of storage. Temperature of the store room decreased from 32.9 ºC - 28.3ºC, while the relative humidity increased from 78% - 86%. Decreased incidence of field fungi namely: Rhizopus oryzae, Aspergillus flavus, Geotricum candidum, Aspergillus fumigatus and Mucor meihei was accompanied by increase in storage fungi viz: Apergillus niger, Mucor hiemalis, Penicillium espansum and Penicillium atrovenetum with prolonged storage. The study showed that out of the three storage materials, jute bag was more effective in preserving AYB seeds. &nbsp

Management protocol of hospitalized patients with COVID-19 in Babcock University Teaching Hospital, Ilishan-Remo, Ogun State, Nigeria

Coronavirus infection became a global pandemic in March 2020. The number of hospitalized cases in Nigeria and Ogun State has been on a steady increase with a concomitant rise in Mortality. This necessitates a coordinated and a more systemic approach in the management of this deadly disease. As a result of the potential effects of the disease on the socio-economic development of Ogun State, the state government granted Babcock University Teaching Hospital, Ilishan-Remo the permission to diagnose, admit and manage cases in line with Nigeria Centre for Disease Control (NCDC)/World Health Organization (WHO) guidelines. This led to the establishment of a molecular laboratory and a COVID-19 task force to oversee the treatment of confirmed cases of COVID-19 disease. This protocol is developed to serve as a template for the diagnosis, admission, treatment of cases of COVID-19 diseases presenting for care in the hospital and to prevent the spread of the disease among healthcare workers within the hospital environment

Yellow Vein Mosaic disease in kenaf (Hibiscus cannabinus l.) under different sowing dates in two agroecologies

Determination of appropriate sowing dates is an important approach towards obtaining optimum crop yield as it affects the resistance/susceptibility of crops to insect pests and diseases. The study investigated the effect of three sowing dates (May, June and July) on the occurrence and incidence of yellow vein mosaic disease in kenaf variety (IFEKEN-100) planted in the experimental fields of the Institute of Agricultural Research and Training (IAR&T) located in Ibadan and Ilora. The incidence of yellow vein mosaic disease was high in May at the two locations with means of 25 and 30% for Ibadan and Ilora, respectively. Plant height was not significantly different in the two locations across the three months. The highest stem diameter was obtained in May from Ilora and Ibadan with means of 1.44 and 1.53 cm, respectively. The best bast fiber yield was recorded in June at Ibadan with a mean value of 1.72 tha-1. Nucleic acid spot hybridization (NASH) was used to confirm the disease and the results revealed that Begomovirus was present in kenaf sowm in the two locations during the period of the three months except in kenaf sown in July at Ilora. The results of this study revealed the importance of sowing dates on the occurrence of viral diseases on the field. If the sowing date is optimum, the effect of viruses may not be pronounced in the crop as seen in the month of June having relatively low virus incidence as well as the highest plant height and bast fibre yield.Keywords: Begomovirus, kenaf, nucleic acid hybridization, yiel

INFLUENCE OF BOTANICALS ON SOIL FERTILITY POTENTIALS, SEED GERMINATION AND PERFORMANCE OF MAIZE (ZEA MAYS) VARIETIES UNDER LOW FERTILE CONTINUOUSLY-CROPPED SOIL CONDITIONS

It is not unreasonable to state that, even before the introduction of organic agriculture, African local farmers have numerous of undocumented environment-friendly, nature-inclined indigenous techniques for boosting soil fertility and enhancing crop yield. However, despite the versatility of indigenous knowledge, setback is always experienced from western science, which tags such knowledge as being non-scientific and not worthy of scholarly engagements. A field experiment was carried out in the year 2013, at the Teaching and Research Farms, Ladoke Akintola University of Technology, Ogbomoso, to assess the soil fertility and yield promoting potentials of some indigenous plant species’ botanicals used as pre-planting treatments on different maize varieties. It was a 3 by 5 factorial experiment. The treatments introduced were: Three (3) maize varieties (V1 = ACR-DMR-SR-Y, V2 = Local EM-W and V3 = Suwan Solo Yellow and five (5) other treatments (comprising pre-sowing botanical treatments of: Kigelia africana only, Glyphea brevis only, combination of Kigelia africana and Glyphea brevis only, NPK fertilizer application (as a reference) and the control (treated with ordinary water only). The trial was laid out in Split Plot in Randomized Complete Block Design (RCBD), replicated three times. Data were collected on growth and yield parameters, and the data collected were analysed using analysis of variance (ANOVA). Means were compared using Duncan Multiple Range Test (DMRT). All the botanical treatments significantly influenced germination, growth, yield and nutrient uptakes of maize, compared to the control. Either of the botanicals tested (with ordinary basal manure application of the pre-existing plant residues on the field), competed effectively with NPK fertilized plants. Hence, since maize responded better to sole treatments of either Kigelia africana or Glyphea brevis extracts, irrespective of varieties than the combined treatment of the two botanicals, any of the maize varieties is therefore recommended as being suitably compatible with either of the sole botanical treatments, in the study area. Thus, this research is reasonable, particularly in the aspects of fertilizer economy, environment-friendliness, organic farming and more profitable crop production in the tropics, where soils are continuously cropped and marginal

Assessing the mycotoxicological risk from consumption of complementary foods by infants and young children in Nigeria

This study assessed, for the first time, the mycotoxicological risks from consumption of complementary foods by infants and young children in Nigeria. Molds belonging to Aspergillus aculeatinus, A. flavus, A. luchuensis, A. tubingensis, A. welwitschiae and Geotrichum candidum were recovered from the complementary foods. Twenty-eight major mycotoxins and derivatives, and another 109 microbial metabolites including chloramphenicol (a bacterial metabolite), were quantified in 137 food samples by LC-MS/MS. Aflatoxins and fumonisins co-contaminated 42% of the cereal- and nut-based food samples, at mean concentrations exceeding the EU limits of 0.1 and 200 μg/kg set for processed baby foods by 300 and six times, respectively. Milk contained mainly beauvericin, chloramphenicol and zearalenone. The trichothecenes, T-2 and HT-2 toxins, were quantified only in infant formula and at levels three times above the EU indicative level of 15 μg/kg for baby food. Chronic exposure estimate to carcinogenic aflatoxin was high causing low margin of exposure (MOE). Exposures to other mycotoxins either exceeded the established reference values by several fold or revealed low MOEs, pointing to important health risks in this highly vulnerable population. The observed mycotoxin mixtures may further increase risks of adverse health outcomes of exposure; this warrants urgent advocacy and regulatory interventions.</p

Chemical Composition and Quality Characteristics of Wheat Bread Supplemented with Leafy Vegetable Powders

The study investigated the effect of supplementation of the leaf powders of Telfairia occidentalis, Amaranthus viridis, and Solanum macrocarpon on the chemical composition and the quality characteristics of wheat bread. The bread samples were supplemented with each of the vegetable leaf powders at 1%, 2%, and 3% during preparation. The bread samples were assayed for proximate composition, mineral composition, physical, sensory, and antioxidant properties using standard methods. The addition of vegetable powders significantly increased the protein (9.50 to 13.93%), fibre (1.81 to 4.00%), ash (1.05 to 2.38%), and fat (1.27 to 2.00%). Supplementation with vegetable powder however significantly decreased (p<0.05) the carbohydrate and moisture contents. Significant (p<0.05) increases were recorded for all evaluated minerals as the level of vegetable powder increased. Supplementation with vegetable powder caused significant decrease in total phenolic content, percentage DPPH inhibition, metal chelating ability, ferric reducing antioxidant power, and total antioxidant capacity. Sensory results showed that there was significant decrease in sensory qualities with increasing supplementation. This therefore suggests that bread supplemented with vegetable powder could have more market penetration if awareness is highly created

Analysis of squat shear wall with different dimensions and position of opening under different type of static loads

Shear walls are usually used in high-rise building or building on high frequency of wind area as the structural element to restrain lateral forces. Openings are created on the shear wall for the architecture, ventilation or mechanical and electrical purposes. With the existence of the opening, the strength of the wall is reduced by the reduction in concrete area and the discontinuity of the reinforcement due to opening which may lead to structural failure. The main objective is to study the effect of size and position of the opening towards the structural behavior of the shear wall under different type of static loads. The analysis is done using the software ANSYS12.0. The samples are SW1, SW2, SW3, SW4, SW5, SW6, SW7 and SW8 where SW1 is solid shear wall while SW2, SW3, SW4, SW5, SW6, SW7 and SW8 are shear walls with different size and position of opening. They are analyzed by using 2 different types of loads which are uniformly distributed axial load and uniformly lateral load. From the same magnitude of loads applied towards the shear walls, they are compared by the cracking pattern and the stress distribution. Under both axial and lateral loads, it shows a significance results that the shear wall with greater opening size shows less efficiency. The position of opening further from the support shows a more significance effect towards the strength of the wall from axial load but opposite from the lateral load. Besides, the closer the position of the shear wall to the load, the less efficient it is. As a conclusion from the results, the most suitable position of the opening on the shear wall is further from the support and the loads and it shows that there is a significance effect even from a smallest opening

Description and Composition of Tree Species in a Tertiary Institution Agricultural Faculty Arboretum, Ibadan, South-West Nigeria

The Arboretum of the Agricultural Faculty of a tertiary institution in Ibadan is known for its rich diversity of trees. Therefore, the study investigates the tree growth variables in the arboretum such as diameter at breast height (dbh), diameter at the base, middle and top of the bole, total height, merchantable height and crown diameter. The basal area and volume were then calculated per species and per family. Several models were fitted for the height – diameter relationship and crown diameter – diameter relationship and crown diameter – dbh relationship. Positive linear relationships were observed among the growth variables. The fitted models showed that cubic models exhibit a more reliable function than quadratic and linear models for crown diameter – dbh predictions as it has R2 above 0.75. Endangered species were observed too and this was indicated through the diversity index obtained. The highest basal area encounter belongs to myrtaceae family (9.61m2) while the lowest belongs to pinaceae family (0.24m2). The total basal area obtained at (31.72m2) from the faculty trees indicates that they are exhibiting better growth and yield

Insolvency of Small Civil Engineering Firms: An Examination of Critical Strategic Factors

Construction industry insolvency studies have failed to stem the industry’s high insolvency tide because many focus on big civil engineering firms (CEF) when over 90% firms in the industry are small or micro (S&M). This study thus set out to uncover insolvency criteria of S&M CEFs and the underlying factors using mixed methods. Using convenience sampling, storytelling method was used to execute interviews of 16 respondents from insolvent firms. Narrative and thematic analysis were used to extract 17 criteria under 2 groups. Criteria were used to formulate questionnaire of which 81 completed copies were received and analysed using Cronbach’s alpha coefficient and relevance index score for reliability and ranking respectively. The five most relevant criteria are: economic recession, immigration, too many new firms springing up, collecting receivables and burden of sustainable construction. The 4 underlying factors established through factor analysis are: market forces, competence-based management, operations efficiency and other management issues and information management. The factors were in line with Mintzberg’s and Porters’ strategy theories. Results demonstrate that insolvency factors affecting big and small CEF can be quite different and sometimes, even opposite. This research will provide a unique resource on the ‘beware’ factors for potential owners of S&M CEF. The criteria are potential variables for insolvency prediction models for S&M CEFs