Discrete approximations to vector spin models

We strengthen a result of two of us on the existence of effective interactions for discretised continuous-spin models. We also point out that such an interaction cannot exist at very low temperatures. Moreover, we compare two ways of discretising continuous-spin models, and show that, except for very low temperatures, they behave similarly in two dimensions. We also discuss some possibilities in higher dimensions.Comment: 12 page

Mechanism(s) Underlying Interactions Between Cattle Manure and Mineral Fertilizer in a Maize Field Soil in Ghana

A 70-day laboratory incubation study was conducted to unravel the mechanism(s) underlying synergistic interactions between organic and inorganic nutrient inputs to the soil. Soil from a maize farmer's field at Kpongu in the Upper West Region of Ghana was amended with a factorial combination of 0, 50% and 100% levels of the recommended rates (RR) of inorganic fertilizer and cattle manure and incubated at room temperature in plastic cups. Deionized water was added to maintain soil moisture at 70% field capacity throughout the incubation period. Cups were covered with gas-permeable parafilm. Soil sampling was done at 7, 28, 42, 56 and 70 days after incubation. The soil was analyzed for available phosphorus, organic carbon, microbial biomass carbon, nitrates, ammonium, soil urease activity, iron, and copper at each sampling. The addition of 100% RR NPK + 50% RR manure often results in higher amounts of the measured parameters,synergistic interactions and supply of nutrients to the soil, with longer residual effects. While all the under-studied mechanisms (improved nutrient synchrony, priming effects, general fertility improvement fertility) contribute to synergistic interactions, the improved nutrient synchrony mechanism is the most prominent. Farmers can therefore manage the timing of the nutrient inputs well to capitalize on this mechanism for improved soil fertility.&nbsp

The bacteria profiles of wounds in diabetic patients hospitalized in northern Kwazulu-Natal, South Africa

Diabetic wound infections still remain a health concern such that correct identification of bacteria is essential in monitoring the spread of the infections as well as in the administration of the correct treatment. This study therefore focuses on isolating and identifying bacteria present in diabetic wounds of hospitalized patients in northern KwaZulu-Natal and assessing their distribution.The wound specimen were collected and swabbed onto selective and differential media. The bacteria identities were presumptively ascertained through biochemical characterization (Gram-stain, catalase test, oxidase test and API) and then confirmed through 16S rDNA sequencing.A total of 42 isolates were recovered from 83% of the patients sampled from the three participating hospitals (X, Y, and Z). Gram-negative bacilli from Enterobacteriaceaewere predominant followed by Staphylococci spp and Enterococcus faecaliswith 43% polymicrobial cases from hospital Z and 29% from hospital X. Distribution of some opportunistic pathogens and nosocomially-acquired pathogens were also observed across the patients with five bacterial identities distributed among hospital X and Z. The adverse effects associated with the recovered bacteria in diabetic wounds pose a serious health concern and preventive measure should be taken.Keywords: Diabetes mellitus, wounds, bacteria, infectio

Seed management by small-scale farmers in Ghana. A study of maize and cowpea seed in the Brong-Ahafo and Volta regions (NRI Bulletin 68)

Field surveys of on-farm maize and cowpea seed management in two regions of southern Ghana are described. The survey included seed obtained off-farm. Samples of seeds were collected just prior to planting and assessed for germination potential. Conclusions are given on the general status and potential for improving seed quality and on farmer seed management. Notes are included on farmer seed management of millet and sorghum in the Upper East Region

Early contractor involvement in government construction projects in Ghana

The importance of Early Contractor Involvement (ECI) and the input in project development has been acknowledged, however little has been done in practice to actually involve contractors early in government projects in Ghana. This study explores the prospects of early contractor involvement in public construction projects in Ghana. It investigates current construction procurement practices, evaluates potential benefits and challenges of ECI and examines the prospects of adopting the practice in public construction procurement. The research adopted quantitative research methodology using survey that solicited the opinions of 100 professionals from contracting organisations, consulting firms and the relevant government ministry. Results from the study shows that some challenges encountered under the traditional procurement route are linked to poor project development. It also reveals that the government of Ghana might be reluctant to try ECI on its projects however, if adopted; the practice could be successfully implemented and perpetuated. The research shows that ECI could be greatly beneficial to public sector projects if the government embraces the concept and explore the numerous benefits that could be achieved; the practice has good prospects in the delivery of public sector construction projects in Ghana

Fertilizer micro-dosing increases crop yield in the Sahelian low-input cropping system: A success with a shadow

Over the years, a scarcity of information on nutrient gains or losses has led to overemphasis being placed on crop yields and economic income as the direct benefits from fertilizer micro-dosing technology. There is increasing concern about the sustainability of this technology in smallholder Sahelian cropping systems. This study was designed in the 2013 and 2014 cropping seasons to establish nutrient balances under fertilizer micro-dosing technology and their implications on soil nutrient stocks. Two fertilizer micro-dosing treatments [2 g hill−1 of diammonium phosphate (DAP) and 6 g hill−1 of compound fertilizer Nitrogen-Phosphorus-Potassium (NPK) (15-15-15)] and three rates of manure (100 g hill−1, 200 g hill−1 and 300 g hill−1) and the relevant control treatments were arranged in a factorial experiment organized in a randomized complete block design with three replications. On average, millet (Pennisetum glaucum (L.) R.Br.) grain yield increased by 39 and 72% for the plots that received the fertilizer micro-dosing of 6 g NPK hill−1 and 2 g DAP hill−1, respectively, in comparison with the unfertilized control plots. The average partial nutrients balances for the two cropping seasons were −37 kg N ha−1yr−1, −1 kg P ha−1yr−1 and −34 kg K ha−1yr−1 in plots that received the application of 2 g DAP hill−1, and −31 kg N ha−1yr−1, −1 kg P ha−1yr−1 and −27 kg K ha−1yr−1 for 6 g NPK hill−1. The transfer of straw yields accounted for 66% N, 55% P and 89% K for removal. The average full nutrient balances for the two cropping seasons in fertilizer micro-dosing treatments were −47.8 kg N ha−1 yr−1, −6.8 kg P ha−1 yr−1 and −21.3 kg K ha−1 yr−1 which represent 7.8, 24.1 and 9.4% of N, P and K stocks, respectively. The nutrient stock to balance ratio (NSB) for N decreased from 13 to 11 and from 15 to 12 for the plots that received the application of 2 g DAP hill−1 and 6 g NPK hill−1, respectively. The average NSB for P did not exceed 5 for the same plots. It was concluded that fertilizer micro-dosing increases the risk of soil nutrient depletion in the Sahelian low-input cropping system. These results have important implications for developing an agro-ecological approach to addressing sustainable food production in the Sahelian smallholder cropping system

Determinants of fertilizer microdosing-induced yield increment of pearl millet on an acid sandy soil

Recent studies have reported the benefits of fertilizer microdosing in increasing crop yields in low input cropping systems. Little information is however available on the mechanisms underlying this effect. The objective of this study was therefore to explore the root-based mechanisms governing the growth enhancing phenomena of the fertilizer microdosing technology. A two-year experiment was conducted at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Research Station in Niger. Four treatments comprising (i) 2 g hill−1 of diammonuim phosphate (DAP), (ii) 6 g hill−1 of compound fertilizer NPK, (iii) broadcasting of 200 kg ha−1 of compound fertilizer NPK (recommended rate) and (iv) unfertilized control was arranged in a randomized complete block design with four replications. On average, fertilizer microdosing treatments (2-g DAP hill−1 and 6-g NPK hill−1) achieved 86% and 79% of the grain yields recorded from broadcasting of 200-kg NPK ha−1, respectively, in 2013 and 2014. The leaf area index and leaf chlorophyll content significantly increased with fertilizer microdosing at the early stage of millet growth. At the same stage, fertilizer microdosing enhanced the lateral root length density in the topsoil (0–20 cm) by 72% and 40% at respective lateral distances of 25 cm and 50 cm from the centre of the hill compared with broadcast of 200-kg NPK ha−1. Fertilizer microdosing did not significantly change soil pH in the root zone. It is concluded that the positive effect of fertilizer microdosing in increasing millet yield results from the better exploitation of soil nutrients due to early lateral roots proliferation within the topsoil

Anti-oxidant, anti-inflammatory and antiacetylcholinesterase activity of betulinic acid and 3β- acetoxybetulinic acid from Melaleuca bracteata ‘Revolution Gold’

Purpose: To evaluate the anti-oxidant, anti-inflammatory and anti-acetylcholine esterase activities of betulinic acid (BA) and 3β- acetoxybetulinic acid (BAA) from Melaleuca bracteata. ‘Revolution Gold’.Methods: Betulinic acid was isolated from the ethyl acetate extract of M. braceteata while BAA was synthesized by acetylation of BA. Structural elucidation of the compounds was achieved by spectroscopic methods. Antioxidant potential was determined using superoxide dismustase (SOD) and catalase assay kits while iron chelation activity assessed with ferrozin. Anti-inflammatory activity was determined using cotton pellet-induced granuloma rat model. Cyclooxygenase (COX) activity evaluated by COX kits; acetylcholine kit was used for anti-acetylcholinesterase (ACHE) study.Results: The compounds significantly (p < 0.05) dose-dependently inhibited ACHE and inflammatory activity. They also significantly decreased the inhibition of SOD, catalase activity but increased iron chelation activities in a dose-dependent manner. However, BAA showed higher activity than BA for all the parameters. BAA also had a greater inhibitory effect on COX-2 than on COX-1. BAA (IC50, 0.88 mg/mL) showed better iron chelation than citric acid (0.96 ± 0.04) and EDTA (1.04 ± 0.03), the positive control.Conclusion: BA and BAA possess anti-ACHE, anti-inflammatory, antioxidant and anti-COX activities. Structural modification of BAA influences its biological activities. Therefore, BAA can potentially serve as a scaffold in synthesizing potent neurodegeneration drugs.Keywords: Betulinic acid, 3β-Acetoxybetulinic acid, Antioxidant, Anti-inflammatory, Antiacetylcholinesterase, Melaleuca bracteata. ‘Revolution Gold

External perceptions of successful university brands

Branding in universities has become an increasingly topical issue, with some institutions committing substantial financial resources to branding activities. The particular characteristics of the sector present challenges for those seeking to build brands and it therefore seems to be timely and appropriate to investigate the common approaches of those institutions perceived as having successful brands. This study is exploratory in nature, seeking to investigate how successfully UK universities brand themselves, whether they are distinct and if the sector overall communicates effectively. This is approached through examining the perspective of opinion formers external to universities but closely involved with the sector – a key stakeholder group in UK higher education Overall, the research’s exploratory nature aims to further the debate on effective branding in UK higher education. The findings and conclusions identify some issues surrounding university branding activity; most UK universities were considered to be distinct from one another, but few were seen to have real fully formed brands. Although a number of institutions that were seen as having more ‘successful’ brands were identified, it was argued that whilst many UK universities communicate their brand well enough to key stakeholders, they fail to consistently do this across all audiences. It was also suggested that UK universities may concentrate on areas of perceived immediate strategic importance (in terms of branding) to an extent where others are neglected

Antithrombotic, anticoagulant and antiplatelet activity of betulinic acid and 3β-acetoxybetulinic acid from Melaleuca bracteata ‘Revolution Gold’ (Myrtaceae) Muell leaf

Purpose: To investigate the antithrombotic, anticoagulant and antiplatelet activity of betulinic acid (BA) and 3β-acetoxybetulinic acid (BAA) from Melaleuca bracteata ‘Revolution Gold’.Methods: Betulinic acid was isolated from the ethyl acetate extract of M. bracteata leaves by column chromatography, from which BAA was subsequently synthesized by acetylation. Structural elucidation of the compounds was conducted using mass spectrometry (MS), infra-red (IR) spectroscopy and nuclear magnetic resonance (NMR). The antithrombotic potential of the compounds was assessed using chromogenic substrate. Anticoagulation studies were carried using bleeding tail time assay in a rat model. Plasma-rich platelets from rats were employed for platelet aggregation studies using light microscope.Results: The compounds significantly (p < 0.05) showed antithrombotic activities in a dose-dependent manner. BAA showed significantly (p < 0.05) higher half-maximal concentration (IC50) value of 1.10 ± 0.03 mg/mL than BA (2.36 ± 0.09 mg/mL) and aspirin (2.65 ± 0.01 mg/mL) which served as positive control. The compounds exhibited anticoagulation activity with poor bleeding time, compared to aspirin. Likewise, the compounds attenuated platelets aggregation induced by thrombin.Conclusion: BAA displays better antithrombotic, antiplatelet, and anticoagulant activities than BA. Therefore, it may be a promising remedy for the management of cardiovascular events.Keywords: Betulinic acid, Thrombin, Anticoagulation, Antiplatelet, Aspirin, Platelet