First report of Rice stripe necrosis virus infecting rice in Benin

International audienc

A steepest descent algorithm for the optimal control of a cascaded hydropower system

Optimal power generation along the cascaded Kainji-Jebba hydroelectric power system had been very difficult to achieve. The reservoirs operating heads are being affected by possible variation in impoundments upstream, stochastic factors that are weather-related, availability of the turbo-alternators and power generated at any time. Proposed in this paper, is an algorithm for solving the optimal release of water on the cascaded hydropower system based on steepest descent method. The uniqueness of this work is the conversion of the infinite dimensional control problem to a finite one, the introduction of clever techniques for choosing the steepest descent step size in each iteration and the nonlinear penalty embedded in the procedure. The control algorithm was implemented in an Excel VBA® environment to solve the ormulated Lagrange problem within an accuracy of 0.03%. It is recommended for use in system studies and control design for the optimal power generation in the cascaded hydropower system

Feature Selection by Multiobjective Optimization: Application to Spam Detection System by Neural Networks and Grasshopper Optimization Algorithm

Networks are strained by spam, which also overloads email servers and blocks mailboxes with unwanted messages and files. Setting the protective level for spam filtering might become even more crucial for email users when malicious steps are taken since they must deal with an increase in the number of valid communications being marked as spam. By finding patterns in email communications, spam detection systems (SDS) have been developed to keep track of spammers and filter email activity. SDS has also enhanced the tool for detecting spam by reducing the rate of false positives and increasing the accuracy of detection. The difficulty with spam classifiers is the abundance of features. The importance of feature selection (FS) comes from its role in directing the feature selection algorithm’s search for ways to improve the SDS’s classification performance and accuracy. As a means of enhancing the performance of the SDS, we use a wrapper technique in this study that is based on the multi-objective grasshopper optimization algorithm (MOGOA) for feature extraction and the recently revised EGOA algorithm for multilayer perceptron (MLP) training. The suggested system’s performance was verified using the SpamBase, SpamAssassin, and UK-2011 datasets. Our research showed that our novel approach outperformed a variety of established practices in the literature by as much as 97.5%, 98.3%, and 96.4% respectively.©2022 the Authors. Published by IEEE. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. For more information, see https://creativecommons.org/licenses/by-nc-nd/4.0/fi=vertaisarvioitu|en=peerReviewed

Prevalence and risk factors for antimicrobial resistance among newborns with gram-negative sepsis

Introduction Newborn sepsis accounts for more than a third of neonatal deaths globally and one in five neonatal deaths in Ethiopia. The first-line treatment recommended by WHO is the combination of gentamicin with ampicillin or benzylpenicillin. Gram-negative bacteria (GNB) are increasingly resistant to previously effective antibiotics. Objectives Our goal was to estimate the prevalence of antibiotic-resistant gram-negative bacteremia and identify risk factors for antibiotic resistance, among newborns with GNB sepsis. Methods At a tertiary hospital in Ethiopia, we enrolled a cohort pregnant women and their newborns, between March and December 2017. Newborns who were followed up until 60 days of life for clinical signs of sepsis. Among the newborns with clinical signs of sepsis, blood samples were cultured; bacterial species were identified and tested for antibiotic susceptibility. We described the prevalence of antibiotic resistance, identified newborn, maternal, and environmental factors associated with multidrug resistance (MDR), and combined resistance to ampicillin and gentamicin (AmpGen), using multivariable regression. Results Of the 119 newborns with gram-negative bacteremia, 80 (67%) were born preterm and 82 (70%) had early-onset sepsis. The most prevalent gram-negative species were Klebsiella pneumoniae 94 (79%) followed by Escherichia coli 10 (8%). Ampicillin resistance was found in 113 cases (95%), cefotaxime 104 (87%), gentamicin 101 (85%), AmpGen 101 (85%), piperacillin-tazobactam 47 (39%), amikacin 10 (8.4%), and Imipenem 1 (0.8%). Prevalence of MDR was 88% (n = 105). Low birthweight and late-onset sepsis (LOS) were associated with higher risks of AmpGen-resistant infections. All-cause mortality was higher among newborns treated with ineffective antibiotics. Conclusion There was significant resistance to current first-line antibiotics and cephalosporins. Additional data are needed from primary care and community settings. Amikacin and piperacillin-tazobactam had lower rates of resistance; however, context-specific assessments of their potential adverse effects, their local availability, and cost-effectiveness would be necessary before selecting a new first-line regimen to help guide clinical decision-making

The Role of Colour Perception in Visual Sustainability: a Survey of Senate Building Facades in Selected Universities in Southwest, Nigeria

Colour perception is essential in the appreciation of the physical world. The inclusion of colour in the consideration of sustainable development of buildings is an important environmental and social factor which calls for distinguishing different colours for diverse building typology. This paper was aimed at identifying public colour preference for senate building facade in selected universities in southwest Nigeria, with a view to establish distinct colour scheme for office buildings. A survey research design was adopted with the stratified random sampling technique used in selecting respondents. Primary data were obtained through the administration of questionnaire to 577 users from ten selected universities. Photographs of 10 selected university senate building façade were attached to the questionnaire to serve as bases for assessing the buildings. Data was analysed using frequencies, percentages and mean ranking. The study revealed that façade colour is an important architectural element for visual sustainability and lighter shades of different colours were observed to be most preferred by the respondents in the study area. The study recommended the need for equipping the design professionals on the fundamentals of colour choices as an architectural design element for building façade attractiveness

Determination of Sulphur Content in the Combustion Products from Artisanal Refineries in the Niger-Delta Region of Nigeria

This study investigated the air pollutants that are associated with combustion of refined petroleum products from artisanal refineries in Nigeria. It characterized refined petroleum products of petrol, diesel and kerosene from randomly selected artisanal refineries in the Niger Delta Region for quality and then characterized their combustion products for air pollutants. The air quality implication of the air pollutants associated with the combustion products of the refined petroleum products were then determined and the treatment methods that might be required to bring the quality of products from these refineries to the level where they can be air quality friendly were then identified. In this study, samples (Premium Motor Spirit (PMS), Automotive Gas Oil (AGO), and Household Kerosene (HHK)) were collected from thirty (30) local refinery in the Niger delta region of Nigeria and their sulphur content were examined to ascertain their conformity with the minimum requirements of the Standard Organisation of Nigeria (SON) and Department of Petroleum Refinery (DPR) on fuel quality. Gravimetric method using Eschka's mixture was used for sulphur content determination. The results showed that sulphur met the SON and DPR standards

First Report of Bacterial Leaf Blight of Rice Caused by Xanthomonas oryzae pv. oryzae in Benin

International audienceIn May 2013, bacterial leaf blight (BLB)-like symptoms were observed on wild rice Oryza longistaminata plants near Tanguiéta town (10°38.721′ N; 1°17.323′ E), near Pendjari National Park, northwest Benin. Symptoms included water-soaked stripes below the leaf tip and on leaf margins. The stripes occasionally enlarged and turned yellow and the most severely affected leaves became greyish-brown with yellow margins on one or both sides ofleaves. For diagnosis, symptomatic 1- to 2-cm2 leaf pieces were surface-sterilized and macerated in sterile water. The resulting sap was subjected to a multiplex PCR assay that is diagnostic for Xanthomonas oryzae pathovars (Lang et al. 2010). A sample yielding the two X. oryzae pv. oryzae-specific DNA fragments (162 and 331 bp) was used to isolate single colonies on semiselective peptone-sucrose-agar (PSA) medium (peptone 10 g/liter, sucrose 10 g/liter, glutamic acid 1 g/liter, bacto agar 16 g/liter, actidione 50 mg/liter, cephalexin, 40 mg/liter, and kasugamycin 20 mg/liter) (Poulin et al. 2014). Incubation at 28°C for 3 to 4 days yielded yellow-pigmented Xanthomonas-like colonies that were mucoid, convex and straw-colored to yellow, like those of the reference strain BAI3 (Gonzalez et al. 2007). One isolate named ABB1 was obtained. Partial DNA sequence analysis of the gyrB gene was conducted upon amplification using the primers XgyrB1F and XgyrB1R (Young et al. 2008). The obtained 645-bp sequence was identical to that of 12 other African X. oryzae pv. oryzae strains (Hajri et al. 2012). The partial nucleotide sequence of the gyrB gene of ABB1 was submitted to GenBank (Accession No. KT325857) and ABB1 was deposited in the Collection Française de Bactéries Phytopathogènes as strain CFBP8172 (http://www6.inra.fr/cirm​/CFBP- Bacteries-associees-aux-Plantes). Pathogenicity assays were conducted on 10 O. sativa ricecultivars as follows: ABB1 was grown overnight in PSA broth and adjusted to 1 × 108 CFU/ml in sterile distilled water. Leaves of 35-day-old rice plants were clipped 2 to 3 cm below the leaf tip with sterile scissors dipped in the bacterial suspension (Gonzalez et al. 2007). Twelve leaves per seedling and 3 to 4 seedlings per accession were inoculated. Control plants were inoculated with sterile distilled water. Fifteen days after incubation in the greenhouse (27 ± 5°C), inoculated leaves exhibited typical bacterial leaf blight lesions, whereas control plants remained symptomless. The reisolated bacteria from diseased leaves yielded colonies that had the same morphology as ABB1, and were confirmed to be X. oryzae pv. oryzae via multiplex PCR and sequence analysis of the gyrB gene portion, fulfilling Koch’s postulates. In 2013, new samples were collected during the rainy (July) and dry (November) seasons from different host plants including rice (O. sativa and O. glaberrima) and wild rice (O. longistaminata) around the site where ABB1 originated. While all samples collected in July were negative in multiplex PCR assays, those collected in November from wild rice (O. longistaminata) led to the isolation of ABB40 and ABB41 that were confirmed as X. oryzae pv. oryzae by multiplex PCR assay and gyrB sequencing. Further studies are needed to clarify the importance of the disease in Benin. If spread from wild to cultivated rice, serious damage can be caused as several farmer-adopted cultivars were found to be highly susceptible to these 3 isolates

A geospatial solution using a TOPSIS approach for prioritizing urban projects in Libya

The world population is growing rapidly; consequently, urbanization has been in an increasing trend in many developing cities around the globe. This rapid growth in population and urbanization have also led to infrastructural development such as transportation systems, sewer, power utilities and many others. One major problem with rapid urbanization in developing/third-world countries is that developments in mega cities are hindered by ineffective planning before construction projects are initiated and mostly developments are random. Libya faces similar problems associated with rapid urbanization. To resolve this, an automating process via effective decision making tools is needed for development in Libyan cities. This study develops a geospatial solution based on GIS and TOPSIS for automating the process of selecting a city or a group of cities for development in Libya. To achieve this goal, fifteen GIS factors were prepared from various data sources including Landsat, MODIS, and ASTER. These factors are categorized into six groups of topography, land use and infrastructure, vegetation, demography, climate, and air quality. The suitability map produced based on the proposed methodology showed that the northern part of the study area, especially the areas surrounding Benghazi city and northern parts of Al Marj and Al Jabal al Akhdar cities, are most suitable. Support Vector Machine (SVM) model accurately classified 1178 samples which is equal to 78.5% of the total samples. The results produced Kappa statistic of 0.67 and average success rate of 0.861. Validation results revealed that the average prediction rate is 0.719. Based on the closeness coefficient statistics, Benghazi, Al Jabal al Akhdar, Al Marj, Darnah, Al Hizam Al Akhdar, and Al Qubbah cities are ranked in that order of suitability. The outputs of this study provide solution to subjective decision making in prioritizing cities for development