CSM-CERES-Rice model to determine management strategies for lowland rice production

The cropping system model, namely, the crop environment resource synthesis-rice (CSM-CERES-Rice) model, is a decision supporting tool for the design of crop management. This study aimed to determine management practices for increasing rice (Oryza sativa L.) production in Laos by using the CSM-CERES-Rice model. The model was evaluated with data sets from the TDK8 and TDK11 cultivars in farmers’ fields in the Vientiane plain in 2012. Anthesis and harvesting dates, growth and yield for various management scenario combinations (eight transplanting dates × two levels of plant densities × three rates of nitrogen (N) fertilizer application) for both cultivars were simulated by the model from 1980 to 2012. The model evaluation results showed strong agreement between simulated and observed data for days to harvest with a difference within four days. The model provided acceptable accuracy for grain yields with normalized root mean square error values ranging between 1 and 16 %. The results from the model application indicated that TDK8 and TDK11 produced similar yields. Transplanting TDK8 with two plant densities produced similar yields. The highest yield for both cultivars was achieved on the transplanting date of 15 Jan. N-fertilizer application at 60 and 120 kg N ha−1 was able to increase yield for TDK8 by 50 and 87 %, respectively, and for TDK11 by 54 and 70 %, respectively. Rice transplanted on 15 Jan with 5 seedlings hill−1 and N-fertilizer at 120 kg N ha−1 had the highest average yield for both cultivars with 6,460 and 6,351 kg ha−1 for TDK8 and TDK11, respectively. The CSM-CERES-Rice model is an alternative tool in determining crop management practices for rice production

CD154-CD40 T-cell co-stimulation pathway is a key mechanism in kidney ischemia-reperfusion injury

© 2015 International Society of Nephrology. Ischemia-reperfusion occurs in a great many clinical settings and contributes to organ failure or dysfunction. CD154-CD40 signaling in leukocyte-endothelial cell interactions or T-cell activation facilitates tissue inflammation and injury. Here we tested a siRNA anti-CD40 in rodent warm and cold ischemia models to check the therapeutic efficacy and anti-inflammatory outcome of in vivo gene silencing. In the warm ischemia model different doses were used, resulting in clear renal function improvement and a structural renoprotective effect. Renal ischemia activated the CD40 gene and protein expression, which was inhibited by intravenous siRNA administration. CD40 gene silencing improved renal inflammatory status, as seen by the reduction of CD68 and CD3 T-cell infiltrates, attenuated pro-inflammatory, and enhanced anti-inflammatory mediators. Furthermore, siRNA administration decreased a spleen pro-inflammatory monocyte subset and reduced TNFα secretion by splenic T cells. In the cold ischemia model with syngeneic and allogeneic renal transplantation, the most effective dose induced similar functional and structural renoprotective effects. Our data show the efficacy of our siRNA in modulating both the local and the systemic inflammatory milieu after an ischemic insult. Thus, CD40 silencing could emerge as a novel therapeutic strategy in solid organ transplantation

Modeling of gas-liquid reactions in porous membrane microreactors

This work provides a numerical model studying mass transport and heterogeneously catalyzed reactions in a porous membrane microreactor. The hydrogenation of nitrite over a Pd catalyst was used as a model reaction. The influence of liquid flow rates, initial nitrite concentration and catalytic membrane layer thickness (wetting thickness) on the conversion was studied. Firstly, a kinetic model was implemented based on the correlations available for reaction kinetics from literature. The results were validated using experimental results and it was found that the process is best described by Langmuir¿Hinshelwood reaction kinetics. Secondly, to obtain an optimized reactor geometry, boundary conditions were derived, which represent the reactant concentration at the microreactor inner wall as a function of catalytic layer properties. An optimum in conversion was found for varying catalytic membrane layer thickness. The initial increase in conversion with increasing catalytic layer thickness is due to enhanced catalyst area. The conversion later reduces due to gaseous reactant mass transfer limitation, for even thicker layers. This study provides detailed understanding of the mass transfer taking place in membrane microreactors. It also provides routes towards optimized reactor configurations, which allows for more efficient catalyzed gas¿liquid reaction processe

ÉLECTROVESTIBULOGRAPHIE PAR ÉLECTRODES À DISTANCE CHEZ L'ANIMAL

In order to produce synchronous detectable responses in the vestibular pathways, electrical stimuli (ES) were applied on guinea pigs cochleas, first during rest then during an angular acceleration. The difference between the signals recorded before and during rotation represented the variation of the response to ES induced by the kinetic excitation and thus represents an electro-vestibulographic (EVG) type of response. EVG responses recorded on the round window and on the vertex were made each of a main negative wave, with a rotation speed threshold of about 2 to 3°/s, with amplitudes proportional to the acceleration culminating respectively to 4 µV and 40 µV with latencies around 0.4 ms and 1.2 ms, which could be associated with the vestibular nerve and nucleus. These results, along with those related to post rotation responses and to selective cochlear and vestibular destructions, confirmed the vestibular specificity of EVG responses.Afin de produire dans les voies vestibulaires des réponses synchrones observables, des stimulations électriques (SE) sont appliquées sur la cochlée du cobaye, au repos puis au cours d'une accélération angulaire. La différence entre les signaux enregistrés avant et pendant la rotation reflète la variation de la réponse à la SE induite par l'excitation cinétique et représente donc une réponse de type électro-vestibulographique (EVG). Les réponses EVG enregistrées sur la fenêtre ronde et le vertex comportent chacune une onde principale négative, de seuil en vitesse voisin de 2 à 3°/s, d'amplitude proportionnelle à l'accélération, et, respectivement, culminant à 40 µV et 4 µV avec des latences voisines de 0,4 ms et 1,2 ms, qui peuvent être associées au nerf et au noyau vestibulaires. Ces résultats, ainsi que ceux relatifs aux réponses post rotatoires et à des destructions vestibulaires et cochléaires sélectives, confirment la spécificité vestibulaire des réponses EVG

Influence of geometrical and operational parameters on the performance of porous catalytic membrane reactors

In this study, porous membrane reactors with various characteristic length (inner diameter), controllable catalyst support thickness, active catalyst surface area and tunable wetting properties are described for heterogeneously catalyzed gas¿liquid¿solid (G¿L¿S) reactions. We developed porous ceramic membrane reactors (Al2O3) with various geometrical parameters and applied these to a model G¿L¿S reaction. Integration of a catalyst support layer (¿-Al2O3), catalyst deposition (palladium) and surface modification (hydrophobization) steps were carried out to tailor these tubular porous ceramic reactors. These reactors were tested for catalytic hydrogenation of nitrite ions () in water for different initial concentrations and flow rates. In addition, to improve the external mass transfer in the liquid phase, we integrated additional slug flow in our porous reactors, merging the advantages of both dispersed phase and membrane reactor operation. Results showed that the reaction rate per Pd-catalyst decreased with increasing thickness of the catalyst support layer, indicating internal mass transfer limitations. Reducing the inner diameter of the reactor and also integration of slug flow enhanced the performance by improving its external mass transfer