Uptake of glycine by excised pulvini of Mimosa pudica in relation to proton pump activity

Uptake of [³H]-glycine by sections of Mimosa pudica L. pulvini is pH dependent (maximum at pH 5.5) and exhibits biphasic saturation kinetics in the range of concentrations tested (1–75 m M ). Effects of compounds which increase [fusicoccin (FC)] or decrease (uncouplers, ATPase inhibitors) the proton-motive force were tested both on the pH variations induced in the incubation medium and on glycine uptake by the pulvinar tissues: there is a close relationship between the time required for the effect of these compounds on the acidification (for FC) and the pH rise (for the inhibitors) of the medium and that needed respectively for promotion and inhibition of glycine uptake. Experiments with sulfhydryl-reacting compounds show that N-ethylmaleimide induces a large rise in pH in the incubation medium and strongly inhibits glycine uptake, whereas p -chloromercuribenzenesulfonic acid has less effect on these processes. These results argue for a proton-glycine symport mechanism in the pulvinar tissue and thus support the previously postulated involvement of a proton pump in the regulation of pulvinar movement.     

Distribution and Frequency of kdr Mutations within Anopheles gambiae s.l. Populations and First Report of the Ace.1G119S Mutation in Anopheles arabiensis from Burkina Faso (West Africa)

An entomological survey was carried out at 15 sites dispersed throughout the three eco-climatic regions of Burkina Faso (West Africa) in order to assess the current distribution and frequency of mutations that confer resistance to insecticides in An. gambiae s.l. populations in the country. Both knockdown (kdr) resistance mutation variants (L1014F and L1014S), that confer resistance to pyrethroid insecticides, were identified concomitant with the ace-1 G119S mutation confirming the presence of multiple resistance mechanisms in the An. gambiae complex in Burkina Faso. Compared to the last survey, the frequency of the L1014F kdr mutation appears to have remained largely stable and relatively high in all species. In contrast, the distribution and frequency of the L1014S mutation has increased significantly in An. gambiae s.l. across much of the country. Furthermore we report, for the first time, the identification of the ace.1 G116S mutation in An. arabiensis populations collected at 8 sites. This mutation, which confers resistance to organophosphate and carbamate insecticides, has been reported previously only in the An. gambiae S and M molecular forms. This finding is significant as organophosphates and carbamates are used in indoor residual sprays (IRS) to control malaria vectors as complementary strategies to the use of pyrethroid impregnated bednets. The occurrence of the three target-site resistance mutations in both An. gambiae molecular forms and now An. arabiensis has significant implications for the control of malaria vector populations in Burkina Faso and for resistance management strategies based on the rotation of insecticides with different modes of action.     

Effects of glycine on dark-and ligh-induced pulvinar movements and modifications of proton fluxes in the pulvinus of Mimosa pudica during glycine uptake

Glycine (1–50 mM) increases the rate of the dark-induced (scotonastic) movements and decreases the amplitude and the rate of the light-induced (photonastic) movements of the secondary pulvini of Mimosa pudica leaves. The uptake of glycine is accompanied by a long-lasting dose-dependent increase in the alkalinity of the bathing medium of the excised pulvini. The data are in agreement with a H⁺-glycine co-transport mechanism within the pulvinar cells. Fusicoccin (50 M), known to promote H⁺–K⁺ exchange, antagonizes the effects of glycine on the movements and the alkalization of the bathing medium of the excised pulvini. The present results argue for the hypothesis that proton fluxes mediate the scotonastic and photonastic pulvinar movements.Abbreviations Gly glycine - FC fusicoccin - P₁ primary pulvinus - P₂ secondary pulvinus     

Inheritance and relationship between key agronomic and quality traits in an interspecific cross between Coffea pseudozanguebariae Bridson and C. canephora Pierre

The inheritance and relationships between four traits of agronomic and quality interest??fructification time, caffeine, and heteroside contents and 100-bean weight??were analyzed in the first backcross hybrids derived from an interspecific cross between Coffea pseudozanguebariae and Coffea canephora. We showed that short vs. long fructification time was governed by one major gene with two co-dominant alleles ft1 and ft2. Absence vs. presence of both caffeine and heteroside was also controlled by one major gene. The allele responsible for the presence of caffeine (caf2) dominated over the absence one (caf1) whereas both alleles controlling heteroside, het1 and het2, were co-dominant. The fructification time and the heteroside content were additive while the caffeine content seemed multiplicative. The 100-bean weight was additive and under a polygenic control. The two genes ft and caf were linked, separated by 30.8?cM, and were independent from the het gene. The relationships between the four traits were not strong enough, except between 100-bean weight and fructification time (r?=?0.43) or caffeine content (r?=?0.41). Recombination occurred between the genes controlling the four traits suggesting that new introgressed Robusta varieties, characterized by short, medium, or long fructification time depending on demand, bigger seeds with low or no caffeine content, and being heteroside-free, could be produced.     

Seamlessly Conductive 3D Nanoarchitecture of Core–Shell Ni‐Co Nanowire Network for Highly Efficient Oxygen Evolution

Electrochemical splitting of water is an attractive way to produce hydrogen fuel as a clean and renewable energy source. However, a major challenge is to accelerate the sluggish kinetics of the anodic half‐cell reaction where oxygen evolution reaction (OER) takes place. Here, a seamlessly conductive 3D architecture is reported with a carbon‐shelled Ni‐Co nanowire network as a highly efficient OER electrocatalyst. Highly porous and granular Ni‐Co nanowires are first grown on a carbon fiber woven fabric utilizing a cost‐effective hydrothermal method and then conductive carbon shell is coated on the Ni‐Co nanowires via glucose carbonization and annealing processes. The conductive carbon layer surrounding the nanowires is introduced to provide a continuous pathway for facile electron transport throughout the whole of the integrated 3D catalyst. This 3D hierarchical structure provides several synergistic effects and beneficial functions including a large number of active sites, easy accessibility of water, fast electron transport, rapid release of oxygen gas, enhanced electrochemical durability, and stronger structural integrity, resulting in a remarkable OER activity that delivers an overpotential of 302 mV with a Tafel slope of 43.6 mV dec^?1 at a current density of 10 mA cm^?2 in an alkaline medium electrolyte (1 m KOH).