Inhibitive effects of 2-mercaptobenzimidazole (MBI) and 2-thiobenzylbenzimidazole (TBBI) on copper corrosion in 1 M nitric acid solution

The inhibitive actions of 2-mercaptobenzimidazole (MBI) and 2-thiobenzylbenzimidazole (TBBI) on copper corrosion in 1M HNO3 medium were studied, using weight loss method, at 25 to 65°C and concentrations of 5.10-5M to 10-3M. The results showed that the two compounds had fairly good inhibiting properties for copper corrosion in the medium, with efficiencies of 90.0% for TBBI and 87.7% for MBI at 25°C and concentration of 10-3M. Modified Langmuir isotherm was found to provide an accurate description of the behavior of the two compounds. The thermodynamic functions of adsorption (ΔG°ads,Qads) and the activation energy (Ea) were calculated. Negative values of changes in free energies were obtained, indicating the spontaneity of the adsorption process. From thermodynamic adsorption and dissolution functions, both physisorption and chemisorption were proposed. Quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE) and dipole moment (μ) were calculated for these compounds, using DFT/B3LYP/6-31G (d,p) method in order to discuss the correlation between theoretical data and experimental results. It was found that theoretical data support the experimental results.Key words: Corrosion Inhibitor, inhibition efficiency, adsorption isotherm, free adsorption energy, adsorption heat, theoretical calculation, dipole moment

Use of insecticide treated bed nets among pregnant women in Kilifi District, Kenya

Background: Malaria is one of the most serious public health problems in Kenya. Pregnant women are among the groups with the highest risk of malaria. Use of insecticide treated bed nets (ITNs) is a cost-effective method of controlling malaria. Despite this, there is low utilisation of ITNs among pregnant women in Kilifi district which is an endemic malaria zone.Objective: To determine knowledge, attitude and practice on the use of ITNs in the prevention of malaria among pregnant women in Kilifi district.Design: A descriptive cross-sectional study. Setting: The district hospital and the five health centres in Kilifi district Subjects: Two hundred and twenty pregnant women attending antenatal clinics (ANC)between October and December 2007.Results: Knowledge on malaria illness and ITNs was high with majority of pregnant women having adequate level of knowledge (86.9%). There was significant association between level of education and adequate knowledge (P-value=0.010). Good attitude on ITNs use was low. There was no association between good attitude and any of the socio-demographic variables. The majority of pregnant women attending ANC owned ITNs (75.4%). ITNs usage was high (70.5%). There was significant association between religion and good practice (p-value=0.050). Although adequate level of knowledge on malaria and protective role of ITNs was high, there was no association between knowledge with practice and attitude.Conclusion: Before any malaria preventive intervention is implemented in an area, different socio-cultural factors must be considered when behavioural interventions for malaria control are designed and implemented. Targeted health education should be disseminated to the community to remove stigma and misconceptions associated with ITNs. Community concerns and fears should be addressed

Morphological diversity of Kenyan papaya germplasm

Papaya is one of the major fruit crops of the tropical regions of the world. It shows considerable phenotypic variation in morphological and horticultural traits that can be utilized in its genetic improvement. In Kenya, wide range of papaya germplasm exists and has not been characterized. Therefore, there is difficulty in differentiating the papaya accessions in the different regions of Kenya. Characterization of papaya germplasm is normally accomplished by use of morphological descriptors, hence as a first step, a germplasm collection from within Kenya was gathered and its morphological diversity was assessed. The papaya germplasm was collected from Coast, Nyanza, Western, Rift Valley, Eastern and Central provinces of Kenya and characterized in the field using morphological descriptors based on fruit, flower, stem and leaf characteristics. The morphological characters were recorded andmorphological data from sixty accessions were submitted to principal component and Neighbor- Joining cluster analysis. Accessions from Coastal, Western, Rift Valley and Nyanza provinces showed the widest morphological diversity with those from Eastern and Central provinces showing the least diversity. Fruit shape, fruit diameter, tree habit, leaf size and flower color showed the greatest variation in principal component analysis. The high diversity observed within the accessions points to ample possibilities of obtaining desirable trait combinations in specific cultivars.Keywords: Kenya, papaya, germplasm, morphological characterizatio

Compensatory and susceptive responses of cowpea genotypes to infestation by aphis Craccivora koch.

The aim of the study was to estimate yield loss to10 selected genotypes of cowpea as a result of Aphis craccivora infestation during the vegetative phase of the crop. There were two trials with four replications. The first trial serving as the control was sprayed at the seedling, flowering andpodding stages against insect pests with lambda cyhalothrin (PAWA®). The other trial was sprayed only at flowering and podding stages. The cowpea seedlings of the second trial were infested with five four-day-old aphids per seedling two weeks after planting. The aphids were allowed to form colonies and fed on the seedlings until symptoms of damage were observed. When the susceptible seedlings became stunted with distorted leaves and yellowing of leaves at two weeks after infestation (28 days after planting), aphids were controlled. The results showed that aphids’ infestation delayed flowering and maturity of genotypes of cowpea. With the exception of early flowering genotypes all the medium to late flowering genotypes produced higher dry grain yield in infested plots than the control plots. The trend was not different from the production of dry biomass. The results of the present study implies that control of aphids infestation inearly maturing cowpea genotypes should not be delayed up to two weeks after infestation or 28 days after planting. Aphid’s infestation period for studies in susceptive response in medium to late maturing genotypes should go beyond 28 days after planting probably up to 35 days afterplanting

Mobile Technology Usage Mediates Gender Differences in Physical Activity

Gender differences in how technology is used to facilitate physical activity engagement was examined. 578 adults completed a survey assessing gender, mobile device usage, stages of change in physical activity based on the transtheoretical model of behaviour change (TTM) and relevant covariates. Data analysis revealed that both cumulative device types and cumulative reasons for using devices mediated gender differences in stage membership for physical activity. Females used fewer devices and reported fewer reasons for using such devices than male participants. These dispositions predicted a reduced probability of achieving action/maintenance stages for physical activity. Females used fewer mobile devices and perceived fewer incentives for using such devices. As a result they are less likely to enter the action/maintenance stages of physical activity. Interventions to promote female participation in physical activity need to recognise gender differences in the use of mobile technology

Adaptive identification of supply chain disruptions through reinforcement learning

Proactive identification and the management of disruption risks play a crucial role in the achievement of a global supply chain's aims. Given the velocity and volume by which such disruption events occur, it is impractical to expect supply chain managers to determine the occurrence of such events manually. Given the pressures facing global supply chains due to the COVID-19 crisis, it is important for supply chain managers to proactively identify disruption risks to their supply chains and manage them to either achieve the outcomes or develop plans by which resilience against them can be built. In this paper, we demonstrate how the integration of natural language processing and reinforcement learning, which are fundamental artificial intelligence methods, can be used to assist supply chain risk managers in the timely identification of such disruption events. We explain in detail our proposed approach, namely RL-SCRI and show its superiority over the current models in achieving its aim

Morphological diversity of mango germplasm from the upper Athi River region of Eastern Kenya: An analysis based on non- fruit descriptors

Phenotypic variation in plants can be evaluated by morphological characterization using visual attributes. Fruits have been the major descriptors for identification of different varieties of fruit crops. However, even in their absence, farmers, breeders and interested stakeholders require to distinguish between different mango varieties. This study aimed at determining diversity in mango germplasm from the Upper Athi River (UAR) and providing useful alternative descriptors for the identification of different mango varieties in the absence of fruits. A total of 20 International Plant Genetic Resources Institute (IPGRI) descriptors for mango were selected for use in the visual assessment of 98 mango accessions from 15 sites of the UAR region of eastern Kenya. Purposive sampling was used to identify farmers growing diverse varieties of mangoes. Evaluation of the descriptors was performed on-site and the data collected were then subjected to multivariate analysis including Principal Component Analysis (PCA) and Cluster analysis, one- way analysis of variance (ANOVA) and Chi square tests. Results classified the accessions into two major groups corresponding to indigenous and exotic varieties. The PCA showed the first six principal components accounting for 75.12% of the total variance. A strong and highly significant correlation was observed between the color of fully grown leaves, leaf blade width, leaf blade length and petiole length and also between the leaf attitude, color of young leaf, stem circumference, tree height, leaf margin, growth habit and fragrance. Useful descriptors for morphological evaluation were 14 out of the selected 20; however, ANOVA and Chi square test revealed that diversity in the accessions was majorly as a result of variations in color of young leaves, leaf attitude, leaf texture, growth habit, leaf blade length, leaf blade width and petiole length traits. These results reveal that mango germplasm in the UAR has significant diversity and that other morphological traits apart from fruits can be useful in morphological characterization of mango.Keywords: Mango, morphological characterization, Principal Component Analysis, IPGRI, eastern Keny

Effects of Bacillus thuringiensis CRY1A(c) d-endotoxin on growth, nodulation and productivity of beans [Phaseolus vulgaris (L.) and siratro (Macroptilium atropurpureum DC.)]

The recent introduction of Bt maize and Bt cotton transgenic crops into Africa has raised concerns on their potential short and long-term ecological effects on the environment. The effects of Bacillus thuringiensis (Bt) Cry1A(c) d-endotoxin on the growth, nodulation and productivity of two leguminous plants grown in clay soil were evaluated. Bt Cry1A(c) d-endotoxin from a local B. thuringiensis isolate (ICIPE L1-2) active against Chilo partellus (Swinhoe) was used. Beans (Phaseolus vulgaris L.) and Siratro (Macroptilium atropurpureum DC.) seedlings were grown in pots treated with Bt Cry1A(c) dendotoxin solution (100 ìg/ml). Control experiments were treated with water. The plants were maintained in the greenhouse until nodulation (8 weeks) and maturity (14 weeks) stages when sampling was done for measurements of morphological, productivity and nodulation traits. Nodulation was observed in both plants species. Nitrogen content in treatments for both bean and siratro plants, withand without Bt-toxin not were significantly different. Leaf area, plant dry weight, number of pods per plants and number of seeds per pod observed in treatments with and without Bt-toxin for both bean and siratro plants were also not significantly different. This shows that Bt Cry1A(c) delta-endotoxin does not interfere with the host plant growth, nodulation and productivity in clay soil. Findings will provide researchers with data to design more robust experiments and will inform the decisions of diversestakeholders regarding the safety of transgenic crops

SIAEF/PoE: Accountability of Earnestness for encoding subjective information in Blockchain

Blockchain technology has the potential to be applied widely in supply chain operations. One such area is proactive supply chain risk management (SCRM). In this area, existing researchers have highlighted the fraudulent behaviour of supply chain partners who do not disclose information on the risks that impact their operations. Blockchain can address this problem by encoding each partner's commitment to SCRM and achieve consensus. However, before this can be achieved, a key challenge to address is the inability of existing consensus mechanisms such as Proof of Work (PoW), Proof of Authority (PoA) and Proof of Stake (PoS) to deal with information that does not have a digital footprint. In this paper, we address this gap by proposing the Proof by Earnestness (PoE) consensus mechanism which accounts for the authenticity, legitimacy and trustworthiness of information that does not have a digital footprint. We also propose the Subjective Information Authenticity Earnestness Framework (SIAEF) as the overarching framework that assists PoE in achieving its aim. We test the applicability of SIAEF and PoE in a real-world blockchain environment by deploying it as a decentralized application (Dapp) and applying it in BscScan Testnet which is an official test blockchain network