32 research outputs found
Phenolic content and heritability of resistance in four hybrid populations of Theobroma cacao L. after leaves inoculation with Phytophthora megakarya Bras. et Grif
Cocoa is cultivated in Cameroon for its broad beans. The commercialization of cocoa seeds constitutes a major source of income to farmers. Nevertheless, cacao black pod disease caused by Phytophthora megakarya is responsible of about 80% of cocoa production loss in Cameroon without any protection method. To assess the resistance of cocoa plants against this pathogen, necrotic lesions and phenolic content were conducted on 3 clones (SNK16, ICS40, Sca12) and their progenies (families F40, F12, F20 and F25) after leaves inoculation. The existence of strong hybrid vigour has been shown. All hybrid genotypes manifested a positive heterosis effect for this symptom suggesting the existence of hybrid vigour. Some hybrids like F40.6, F40.7, F40.8, F40.9, F40.10, F12.10, F12.15, F20.7, F20.10, F25.2, F25.5 and F25.7 were characterized by localized lesions. A negative correlation between the size of necrotic lesions and the total phenolic compound was demonstrated. Three genotypes of the F40 family (F40.8, F40.9 and F40.13), one of the F12 (F12.15) and two of the F25 (F25.2 and F25.8) had small lesions and high concentrations of phenols. These six genotypes can be considered as elite clones with high tolerance to P. megakarya. The values of the heritability of lesion size and the total phenolic content in offsprings donât show the maternal effect.Keywords: Cocoa, Phytophthora megakarya, heterosis, heritability, necrosis, phenol
Facility-Based Treatment of Under Five Diarrhoea in Cross River State: A Clinical Audit
Introduction: Diarrhoea is the second leading cause of under-five mortality globally and ranks second among the top 10 priority child health problems in Nigeria. The World Health Organization (WHO) has recommended some cost-effective, evidence- based interventions for diarrhoea case management. It is needful to evaluate the current practice in the treatment of diarrhoea in under-fives in health facilities in the country.Objective: To determine the extent to which current treatment practice for diarrhoea in underfives conforms to the WHO recommendation.Method: A clinical audit was conducted between May and June 2013 in 32 health facilities in the Southern Senatorial district of Cross River State, Nigeria. Trained field workers extracted information from patientsâ case records using a validated audit tool. Treatment was checked as appropriate, inappropriate, wrong or none, based on prescription on patientsâ case records.Result: Of the 370 case records audited, prescription for diarrhoea was appropriate in 40 (10.8%), inappropriate in 231 (62.4%), wrong in 82 (22.2%) and no prescription was made in 17 (4.6%).Conclusion: Treatment of diarrhoea in under-fives in health facilities in the State is suboptimum. Retraining of health workers on the current WHO and UNICEF treatment guidelines is highly recommended.Keywords: Diarrhoea, Underfives, Health Facilities, Prescription, Clinical Audi
Physiological and genetic control of transpiration efficiency in African rice, Oryza glaberrima Steud
Improving crop water use efficiency, the amount of carbon assimilated as biomass per unit of water used by a plant, is of major importance as water for agriculture becomes scarcer. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative component trait transpiration restriction under high evaporative demand remain unknown. These traits were measured in 2019 in a panel of 147 African rice (Oryza glaberrima) genotypes known to be potential sources of tolerance genes to biotic and abiotic stresses. Our results reveal that higher transpiration efficiency is associated with transpiration restriction in African rice. Detailed measurements in a subset of highly contrasted genotypes in terms of biomass accumulation and transpiration confirmed these associations and suggested that root to shoot ratio played an important role in transpiration restriction. Genome wide association studies identified marker-trait associations for transpiration response to evaporative demand, transpiration efficiency, and its residuals, with links to genes involved in water transport and cell wall patterning. Our data suggest that root-shoot partitioning is an important component of transpiration restriction that has a positive effect on transpiration efficiency in African rice. Both traits are heritable and define targets for breeding rice with improved water use strategies.This work was supported by the Institut de Recherche pour le DĂ©veloppement, the CGIAR Research Program (CRP) on rice-agrifood systems (RICE, 2017-2022) and the Agence Nationale de la Recherche (grant ANR-17-MPGA-0011 to VV). Financial support by the Access to Research Infrastructures activity in the Horizon 2020 Programme of the EU (EPPN2020 Grant Agreement 731013) is gratefully acknowledged. PA was supported by a doctoral fellowship from the French Ministry of Higher Education. BEE was supported by the Centre National de la Recherche Scientifique et Technologique of Gabon. The authors acknowledge the IRD iTrop HPC (South Green Platform) at IRD Montpellier for providing HPC resources (https://bioinfo.ird.fr, http://www.southgreen.fr)
Understanding and retention of the informed consent process among parents in rural northern Ghana
<p>Abstract</p> <p>Background</p> <p>The individual informed consent model remains critical to the ethical conduct and regulation of research involving human beings. Parental informed consent process in a rural setting of northern Ghana was studied to describe comprehension and retention among parents as part of the evaluation of the existing informed consent process.</p> <p>Methods</p> <p>The study involved 270 female parents who gave consent for their children to participate in a prospective cohort study that evaluated immune correlates of protection against childhood malaria in northern Ghana. A semi-structured interview with questions based on the informed consent themes was administered. Parents were interviewed on their comprehension and retention of the process and also on ways to improve upon the existing process.</p> <p>Results</p> <p>The average parental age was 33.3 years (range 18â62), married women constituted a majority (91.9%), Christians (71.9%), farmers (62.2%) and those with no formal education (53.7%). Only 3% had ever taken part in a research and 54% had at least one relation ever participate in a research. About 90% of parents knew their children were involved in a research study that was not related to medical care, and 66% said the study procedures were thoroughly explained to them. Approximately, 70% recalled the study involved direct benefits compared with 20% for direct risks. The majority (95%) understood study participation was completely voluntary but only 21% recalled they could withdraw from the study without giving reasons. Younger parents had more consistent comprehension than older ones. Maternal reasons for allowing their children to take part in the research were free medical care (36.5%), better medical care (18.8%), general benefits (29.4%), contribution to research in the area (8.8%) and benefit to the community (1.8%). Parental suggestions for improving the consent process included devoting more time for explanations (46.9%), use of the local languages (15.9%) and obtaining consent at home (10.3%).</p> <p>Conclusion</p> <p>Significant but varied comprehension of the informed consent process exists among parents who participate in research activities in northern Ghana and it appears the existing practices are fairly effective in informing research participants in the study area.</p
Embedded Software of the KM3NeT Central Logic Board
The KM3NeT Collaboration is building and operating two deep sea neutrino
telescopes at the bottom of the Mediterranean Sea. The telescopes consist of
latices of photomultiplier tubes housed in pressure-resistant glass spheres,
called digital optical modules and arranged in vertical detection units. The
two main scientific goals are the determination of the neutrino mass ordering
and the discovery and observation of high-energy neutrino sources in the
Universe. Neutrinos are detected via the Cherenkov light, which is induced by
charged particles originated in neutrino interactions. The photomultiplier
tubes convert the Cherenkov light into electrical signals that are acquired and
timestamped by the acquisition electronics. Each optical module houses the
acquisition electronics for collecting and timestamping the photomultiplier
signals with one nanosecond accuracy. Once finished, the two telescopes will
have installed more than six thousand optical acquisition nodes, completing one
of the more complex networks in the world in terms of operation and
synchronization. The embedded software running in the acquisition nodes has
been designed to provide a framework that will operate with different hardware
versions and functionalities. The hardware will not be accessible once in
operation, which complicates the embedded software architecture. The embedded
software provides a set of tools to facilitate remote manageability of the
deployed hardware, including safe reconfiguration of the firmware. This paper
presents the architecture and the techniques, methods and implementation of the
embedded software running in the acquisition nodes of the KM3NeT neutrino
telescopes
Arbuscular mycorrhizal symbiosis in rice: Establishment, environmental control and impact on plant growth and resistance to abiotic stresses
Rice is one of the most consumed crop around the globe and its production needs to be increased in a context of climate change and water scarcity. Rice roots, as most land plants, can establish symbiotic association with arbuscular mycorrhizal fungi (AMF). Rice has emerged, in the past decade, as a model to study the molecular determinants of AM symbiosis establishment and functioning, providing insight into potential breeding target to improve the capacity of this crop to interact with AMF. Furthermore, evidences showing the beneficial effects of AMF on rice performance in field conditions and resistance to abiotic stresses in controlled conditions are increasing. In this review, we describe recent discoveries about rice root AMF interactions and collect evidences supporting the idea that AM symbiosis can be used to develop agronomic practices for sustainable rice production and rice resistance to abiotic stresses
Arbuscular mycorrhizal symbiosis in rice: Establishment, environmental control and impact on plant growth and resistance to abiotic stresses
International audienceRice is one of the most consumed crop around the globe and its production needs to be increased in a context of climate change and water scarcity. Rice roots, as most land plants, can establish symbiotic association with arbuscular mycorrhizal fungi (AMF). Rice has emerged, in the past decade, as a model to study the molecular determinants of AM symbiosis establishment and functioning, providing insight into potential breeding target to improve the capacity of this crop to interact with AMF. Furthermore, evidences showing the beneficial effects of AMF on rice performance in field conditions and resistance to abiotic stresses in controlled conditions are increasing. In this review, we describe recent discoveries about rice root AMF interactions and collect evidences supporting the idea that AM symbiosis can be used to develop agronomic practices for sustainable rice production and rice resistance to abiotic stresses
A Novel Virtual Button User Interface for Determining the Characteristics of an Impulse Input Based on MEMS Inertial Sensors
This paper introduces a novel application of MEMS accelerometers in consumer electronics for âVirtual Buttonâ technology. The MEMS accelerometer is designed to measure low-g acceleration and sense tapping motion on a cell phone, consumer electronic, medical user interface, or harsh environment user interface. In this paper we outline this patent pending application and discuss the modeling and analysis of the accelerometer designed for this purpose. Prior art in impulse localization with inertial sensors is discussed. The features of the Virtual Button user interface are presented and applications of Virtual Buttons to medical, touch screen, and hand-held electronic devices are discussed. The initial considerations for the design of an accelerometer with an operating range of 0.5-20 and noise levels of less than 0.124 mg (Hz)^0.5 are also presented
Optimization of Sensorless Sliding Mode Control of an Induction Motor Taking Into Account Magnetic Saturation Effects
This paper presents the optimization of sensorless sliding-mode control for induction motor, considering magnetic saturation effects. A five-order sliding-mode observers and estimators are elaborated to replace the sensors of an induction motor. The proposal is based on double optimization of sensorless sliding mode control of an induction motor in the point of view of dynamic and energetic performances. In order to obtain better performances of the proposed control method, Particle Swarm Optimization (PSO) algorithm is used notably to determine the optimal gains of the observers as well as the optimal parameters of the regulators. Regarding the energetic optimization, the reference of the rotor flux is generated using another developed algorithm that permits us to dynamically determine the optimal rotor flux for each given value of motor load and speed. As results, sensorless sliding mode control takes into account all operating ranges of the machine from very low speeds, low speeds, to high speed with or without load. Numerical simulations are carried out each time to confirm theoretical predictions
Amino acids, carbohydrates and heritability of resistance in Theobroma cacao/ Phythophtora megakarya interaction.
The black pod disease of cocoa (Theobroma cacao), caused by Phythophthora megakarya, is responsible for 80% loss of cocoa production in Cameroon. The principal method of ameliorating crop losses is through the use of black pod resistant and high productivity hybrid cocao clones. In order to assess the possible role of amino acids and carbohydrates in the defence of T. cacao against P. megakarya, comparative analyses (quantitative and qualitative) of sugars and amino acids were carried out on leaves of parental genotypes, ICS95, ICS84 and hybrids (families F25:âICS84 X âICS95 and F30: âICS95 X âICS84 ). A reduction in soluble sugar contents of parental genotypes ICS84, ICS95 and 30% of hybrid genotypes was noted under conditions of infection. Qualitative analyses of sugars showed that most cases of infection were characterized by the disappearance of sucrose and the persistence of glucose. Amino acids content increased in 70% of genotypes after injury or infection. In parental tolerant clone ICS84 and hybrid genotypes F3011, F2551 and F2552, proline appeared solely during conditions of infection, suggesting its implication in the defence mechanism of T. cacao against P. megakarya. A significant positive relationship was observed between amino acid contents and the severity of necrosis. There was a very weak relationship between sugar and amino acid contents in parental genotype, and those of the progeny. PCA of the length of necrosis, sugar level, amino acids and phenolics showed that under infection, the increase in content of phenolic compound was concomitant with reduction in amino acid content