Efficacy and Pertinence 01 Heat Treatments against Monilia Decay in Commerciai Condition

Post-harvest decay can lead to very important damages on stone fruits. especially in the Rhone valley. Hot water treatments are known to be efficient against many fruit pathogens including monilia, but industriai application remains difficult, since it can present some risks according to fruit maturity, thermostat accuracy of the engine We went on trying this alternative on peach decay, by testing a prototype lend by Xeda, in a professional station. Several parameters were to be evaluated : temperature and length of treatment, relation between both, container emptying, application of treatment period At the sa me time, we intended to assess eugenol (essenti al oil of clover) efficacy when added in hot water, for different concentrations, up to phytotoxicity

Orienting Ion-Containing Block Copolymers Using Ac Electric Fields

ABSTRACT: We consider orientation mechanisms for block copolymers in an electric field. Theoretical and experimental studies have shown that nonuniformity of the dielectric constant gives rise to a preferred orientation of the melt with respect to the applied field. We show that the presence of ions, as found in anionically prepared copolymers, may increase the alignment effect markedly. Time-varying (ac) and static (dc) fields are considered within a unified framework. We find that orientation of block copolymers can in principle be achieved without a dielectric contrast if there is a mobility contrast. The presence of ions is especially important at small field frequencies, as is in most experiments. Unlike the no-ions case, it is found that orienting forces depend on the polymer chain lengths. The mobile-ions mechanism suggested here can be used to reduce the magnitude of orienting fields as well as to discriminate between block copolymers of different lengths

Numerical analysis of the dynamic behaviour of a nonlinear preloaded intervertebral disc

In order to understand the mechanisms in degenerative disc disease and support the design of robust disc prothesis, accurate modelling of the intervertebral disc's (IVD) dynamics is necessary. Many experimental studies relate changes in the mechanical properties of the disk to the degenerative state of the IVD. However, further studies are necessary to better assess the influence of parameters which may affect those mechanical properties on the dynamic behaviour of the IVD, especially its dissipative behaviour. The goal of this work is to investigate the effect the static preload and the frequency of excitation through numerical simulations

D2-Like Receptors Mediate the Expulsion Phase of Ejaculation Elicited by 8-Hydroxy-2-(di-N-propylamino)tetralin in Rats

ABSTRACT The mechanism of action by which 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) facilitates ejaculation in conscious rats is not clearly established. The serotonin (5-HT) 1A agonist 8-OH-DPAT may actually act on cerebral dopaminergic receptors to exert its proejaculatory effect. The present work was undertaken to clarify this issue by testing various compounds i

Methyl-laudanosine: A new pharmacological tool to investigate the function of small-conductance Ca2+-activated K+ channels

ABSTRACT Small-conductance Ca 2ϩ -activated K ϩ channels (SK channels) underlie the prolonged postspike afterhyperpolarization (AHP) observed in many central neurons and play an important role in modulating neuronal activity. However, a lack of specific and reversible blockers of these channels hampers their study in various experimental conditions. Because previous work has shown that bicuculline salts block these channels, we examined whether related alkaloids, namely laudanosine quaternary derivatives, would produce similar effects. Intracellular recordings were performed on rat midbrain dopaminergic neurons and hippocampus CA1 pyramidal cells. Binding experiments were performed on rat cerebral cortex membranes. Laudanosine, methyl-laudanosine, and ethyl-laudanosine blocked the apamin-sensitive AHP of dopaminergic neurons with mean IC 50 values of 152, 15, and 47 M, respectively. The benzyl and butyl derivatives were less potent. Methyl-laudanosine had no effect on the I h current, action potential parameters, or membrane resistance of dopaminergic cells, or on the decrease in input resistance induced by muscimol, indicating a lack of antagonism at GABA A receptors. Interestingly, 100 M methyllaudanosine induced a significant increase in spiking frequency of dopaminergic neurons but not of CA1 pyramidal cells, suggesting the possibility of regional selectivity. Binding experiments on laudanosine derivatives were in good agreement with electrophysiological data. Moreover, methyl-laudanosine has no affinity for voltage-gated potassium channels, and its affinity for SK channels (IC 50 4 M) is superior to its affinity for muscarinic (IC 50 114 M) and neuronal nicotinic (IC 50 Ն367 M) receptors . Methyl-laudanosine may be a valuable pharmacological tool to investigate the role of SK channels in various experimental models. Other than neurotransmitter receptors and transporters, ion channels constitute an attractive target to develop new drugs that will be active on the central nervous system. Currently, the only ion channel that is well established as a central nervous system target is the voltage-gated Na ϩ channel, which is blocked by antiepileptic drugs such as phenytoin, carbamazepine, and lamotrigine Evidence suggests that SK-channel modulation may be interesting in a range of central nervous system disorders, This work was supported in part by Grant 3.4525.98 from the National Fund for Scientific Research (Brussels, Belgium). This work has been presented in meeting abstract form: Scuvée-Moreau J, Liégeois JF, and Seutin V (2002) Effect of laudanosine derivatives on the apamin-sensitive afterhyperpolarization of rat dopaminergic neurons-identification of methyl-laudanosine as a new specific blocker (Abstract). Fundam Clin Pharmacol 16:67

Development of MPS Method for Analysing Convection and Solidification of Multi-Component Corium in Severe Accident of a Light Water Reactor

In this study, a numerical approach for analyzing the internal status of Molten CoreConcrete Interaction (MCCI) has been developed based on Moving Particle Semi-implicit (MPS) method. Among the key required models, such as accurate viscosity interaction model for solidifying particles and interface tension models of different liquid phases, preliminary attempts have been made with new models. Namely, a simple mixing model and gas hosting particle model has been implemented to simulate the experiment with affordable calculation cost. The analysis results for VULCANO VF-U1 experiment have shown the possible mechanisms responsible for the characteristic distribution of the solidified metallic corium, which seemed to be highly dependent on the density of surrounding oxidic coriu

A Novel Nonpeptide Antagonist of the Kinin B 1 Receptor: Effects at the Rabbit Receptor

ABSTRACT The kinin B 1 receptor (B 1 R) has attracted interest as a potential therapeutic target because this inducible G protein-coupled receptor is involved in sustained inflammation and inflammatory pain production. is a high-affinity nonpeptide antagonist for the human B 1 R, but it is potent at the rabbit B 1 R as well: its K i value for the inhibition of [ The kinin B 1 receptor (B 1 R) is a G protein-coupled receptor selectively stimulated by sequences related to bradykinin (BK) but not by BK itself. Instead, des-Arg 9 -BK, Lys-BK (kallidin) and Lys-des-Arg 9 -BK (des-Arg 1

A Decomposition Heuristic for the Maximal Covering Location Problem

This paper proposes a cluster partitioning technique to calculate improved upper bounds to the optimal solution of maximal covering location problems. Given a covering distance, a graph is built considering as vertices the potential facility locations, and with an edge connecting each pair of facilities that attend a same client. Coupling constraints, corresponding to some edges of this graph, are identified and relaxed in the Lagrangean way, resulting in disconnected subgraphs representing smaller subproblems that are computationally easier to solve by exact methods. The proposed technique is compared to the classical approach, using real data and instances from the available literature