Évaluation de l’efficacité de l’insecticide Tricel 480 EC comparée à la Deltamétrine et à la Cyperméthrine contre les ravageurs du chou (Brassicacae L. sp.) en milieu paysan dans la région de Yamoussoukro en Côte d’Ivoire

Afin decontrôler l’utilisation croissante et non raisonnée de produits phytosanitaires contre les ravageurs des cultures maraîchères, 3 doses du TRIC 480 EC (0,8 L/ha, 1 L/ha et 2 L/ha), ont été testées. Il s’agit dedéterminer la dose optimale d’utilisation pour la réduction efficiente des populations d’insectes ravageurs du chou (Brassicacae L. sp.) comparée à celles de la Deltaméthrine (12g/L) et du Cypermétrine (50g/L), deux formulations de référence utilisées contre les ravageurs du chou en milieu paysan et le témoin non traité. Un dispositif en Split-plot avec trois  répétitions par objet a été utilisé. Les ravageurs prédominants relevéssont les Homoptères (pucerons), les Orthoptères (sautériaux), les larves de Lépidoptères (Plutellaxylostella) et de Diptères. Les 3 doses du TRIC 480 EC permettent de réduire de 80 %, les populations de pucerons etdonc les pertes par la dégénérescence des plants de chou. Contrôle qui est significativement différent de la Deltaméthrine (12g/L) et de la  Cyperméthrine (50g/L) (P = 0,018 < 0,05). La dose de 0,8 L/ha de TRIC 480 EC contre les ravageurs du chou, avec une application hebdomadaire en pulvérisation dès le repiquage jusqu’à une semaine avant les récoltes peut être recommandée aux paysans.Mots-clés : Chou (Brassicacae L. sp.), insectes ravageurs, TRIC 480 EC, Cyperméthrine 50 EC, Deltaméthrine 12 EC, doses efficaces

Minéralogie de la fraction argileuse des sols brunifiés de Kahankro et Anikro (Toumodi) dans le Centre Sud de la Côte d’Ivoire

Dans la perspective d’élucider les occurrences minéralogiques des sols brunifiés de Kahankro et de Anikro (Toumodi), dans la région centre de la Côte d’Ivoire, nous nous sommes intéressés à la fraction argileuse des sols. Cette étude, dans sa phase technique, a consisté à extraire la fraction argileuse des échantillons de sol prélevés sur le terrain en s’appuyant sur la méthode de Hotzapfel. Ces échantillons, de même que ceux du sol total, ont été ensuite soumis à une analyse aux rayons X sur lame orientée séchée à l’air puis, à des analyses thermodifférentielles et thermopondérales à une température allant jusqu’à 1200 °C. Les résultats obtenus au bout de cette étude indiquent que les sols brunifiés de Kahankro et de Anikro contiennent différents types de minéraux existant en des proportions aussi variées. Il s’agit des oxydes (quartz, hématite,ilménite et boéhmite) avec une proportion généralement supérieure à 39%, des minéraux primaires (feldspaths, olivine, dolomite et calcite) ayant une proportion supérieure à 30% et des minéraux argileux (kaolinite, illite et chlorite) qui existent en une proportion généralement inférieure à 25%. Le phénomène d’argilation qui prévaut dans ces sols est la monosiallitisation, vu la prédominance de minéraux argileux de type 1/1 (kaolinite) sur les autres minéraux argileux. A cette monosiallitisation s’adjoint une bisiallitisation gouvernée par la richesse des sols en minéraux primaires. Ces sols sont aussi affectés par un phénomène de ferrallitisation et les paragenèses minérales de type kaolinite-hématite permettent de les définir comme étant caractéristiques d’une couvertured’altération mixte.Mots clés : Occurrences minéralogiques, phénomène d’argilation, ferrallitisation

n-type chalcogenides by ion implantation.

Carrier-type reversal to enable the formation of semiconductor p-n junctions is a prerequisite for many electronic applications. Chalcogenide glasses are p-type semiconductors and their applications have been limited by the extraordinary difficulty in obtaining n-type conductivity. The ability to form chalcogenide glass p-n junctions could improve the performance of phase-change memory and thermoelectric devices and allow the direct electronic control of nonlinear optical devices. Previously, carrier-type reversal has been restricted to the GeCh (Ch=S, Se, Te) family of glasses, with very high Bi or Pb 'doping' concentrations (~5-11 at.%), incorporated during high-temperature glass melting. Here we report the first n-type doping of chalcogenide glasses by ion implantation of Bi into GeTe and GaLaSO amorphous films, demonstrating rectification and photocurrent in a Bi-implanted GaLaSO device. The electrical doping effect of Bi is observed at a 100 times lower concentration than for Bi melt-doped GeCh glasses.This work was supported by the UK EPSRC grants EP/I018417/1, EP/I019065/1 and EP/I018050/1.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ncomms634

Microbial fuel cells: a green and alternative source for bioenergy production

Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

The interaction between a sexually transferred steroid hormone and a female protein regulates oogenesis in the malaria mosquito anopheles gambiae

Molecular interactions between male and female factors during mating profoundly affect the reproductive behavior and physiology of female insects. In natural populations of the malaria mosquito Anopheles gambiae, blood-fed females direct nutritional resources towards oogenesis only when inseminated. Here we show that the mating-dependent pathway of egg development in these mosquitoes is regulated by the interaction between the steroid hormone 20-hydroxy-ecdysone (20E) transferred by males during copulation and a female Mating-Induced Stimulator of Oogenesis (MISO) protein. RNAi silencing of MISO abolishes the increase in oogenesis caused by mating in blood-fed females, causes a delay in oocyte development, and impairs the function of male-transferred 20E. Co-immunoprecipitation experiments show that MISO and 20E interact in the female reproductive tract. Moreover MISO expression after mating is induced by 20E via the Ecdysone Receptor, demonstrating a close cooperation between the two factors. Male-transferred 20E therefore acts as a mating signal that females translate into an increased investment in egg development via a MISO-dependent pathway. The identification of this male–female reproductive interaction offers novel opportunities for the control of mosquito populations that transmit malaria

The relationship between the time of cerebral desaturation episodes and outcome in aneurysmal subarachnoid haemorrhage: a preliminary study.

In this preliminary study we investigated the relationship between the time of cerebral desaturation episodes (CDEs), the severity of the haemorrhage, and the short-term outcome in patients with aneurysmal subarachnoid haemorrhage (aSAH). Thirty eight patents diagnosed with aneurysmal subarachnoid haemorrhage were analysed in this study. Regional cerebral oxygenation (rSO2) was assessed using near infrared spectroscopy (NIRS). A CDE was defined as rSO2 < 60% with a duration of at least 30 min. The severity of the aSAH was assessed using the Hunt and Hess scale and the short-term outcome was evaluated utilizing the Glasgow Outcome Scale. CDEs were found in 44% of the group. The total time of the CDEs and the time of the longest CDE on the contralateral side were longer in patients with severe versus moderate aSAH [h:min]: 8:15 (6:26-8:55) versus 1:24 (1:18-4:18), p = 0.038 and 2:05 (2:00-5:19) versus 0:48 (0:44-2:12), p = 0.038. The time of the longest CDE on the ipsilateral side was longer in patients with poor versus good short-term outcome [h:min]: 5:43 (3:05-9:36) versus 1:47 (0:42-2:10), p = 0.018. The logistic regression model for poor short-term outcome included median ABP, the extent of the haemorrhage in the Fisher scale and the time of the longest CDE. We have demonstrated that the time of a CDE is associated with the severity of haemorrhage and short-term outcome in aSAH patients. A NIRS measurement may provide valuable predictive information and could be considered as additional method of neuromonitoring of patients with aSAH

The sudden change phenomenon of quantum discord

Even if the parameters determining a system's state are varied smoothly, the behavior of quantum correlations alike to quantum discord, and of its classical counterparts, can be very peculiar, with the appearance of non-analyticities in its rate of change. Here we review this sudden change phenomenon (SCP) discussing some important points related to it: Its uncovering, interpretations, and experimental verifications, its use in the context of the emergence of the pointer basis in a quantum measurement process, its appearance and universality under Markovian and non-Markovian dynamics, its theoretical and experimental investigation in some other physical scenarios, and the related phenomenon of double sudden change of trace distance discord. Several open questions are identified, and we envisage that in answering them we will gain significant further insight about the relation between the SCP and the symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F. F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp 309-33

Sentinel surveillance for human enterovirus 71 in Sarawak, Malaysia: lessons from the first 7 years

BACKGROUND: A major outbreak of human enterovirus 71-associated hand, foot and mouth disease in Sarawak in 1997 marked the beginning of a series of outbreaks in the Asia Pacific region. Some of these outbreaks had unusually high numbers of fatalities and this generated much fear and anxiety in the region. METHODS: We established a sentinel surveillance programme for hand, foot and mouth disease in Sarawak, Malaysia, in March 1998, and the observations of the first 7 years are described here. Virus isolation, serotyping and genotyping were performed on throat, rectal, vesicle and other swabs. RESULTS: During this period Sarawak had two outbreaks of human enterovirus 71, in 2000 and 2003. The predominant strains circulating in the outbreaks of 1997, 2000 and 2003 were all from genogroup B, but the strains isolated during each outbreak were genetically distinct from each other. Human enterovirus 71 outbreaks occurred in a cyclical pattern every three years and Coxsackievirus A16 co-circulated with human enterovirus 71. Although vesicles were most likely to yield an isolate, this sample was not generally available from most cases and obtaining throat swabs was thus found to be the most efficient way to obtain virological information. CONCLUSION: Knowledge of the epidemiology of human enterovirus 71 transmission will allow public health personnel to predict when outbreaks might occur and to plan interventions in an effective manner in order to reduce the burden of disease