Differential Sensitivity of Mosquito Taxa to Vegetable Tannins

The sensitivity of larval Culicidae to vegetable tannins was investigated in different taxa representative of the fauna from alpine hydrosystems (Aedes rusticus, Culex pipiens) and foreign noxious fauna (Aedes aegypti, A. albopictus). Bioassays reveal that tannic acid at concentrations of 0.1–6 mM is significantly more toxic for C. pipiens than for Aedes taxa, and A. aegypti is more sensitive than A. albopictus and A. rusticus. Comparison of the rank order of sensitivity among taxa with the associated levels of cytochrome P-450, esterase, and glutathione-S-transferase activities suggests that cytochrome P-450 and esterases may be involved in the detoxification of tannins. A possible involvement of these detoxifying enzymes is also revealed in vivo by the synergistic effects of S,S,S-tributyl phosphorotrithioate (esterase inhibitor) and piperonyl butoxide (P-450 inhibitor). The differential sensitivity to tannins among taxa is discussed in terms of ecological implications within mosquito communities from alpine hydrosystems, where the acquisition of tannins–detoxifying enzymatic systems may be considered as a key innovation.     

State estimation of a batch hydrogen production process using the photosynthetic bacteria Rhodobacter capsulatus

This paper addresses the problem of estimating the states of an anaerobic photosynthetic process used for biohydrogen production by the photosynthetic bacterium Rhodobacter capsulatus. The process is described by a non-linear, time-discrete model and the state estimation is solved using an observer based on the Moving-Horizon State Estimation Method (MHSE). This approach is based on the minimization of a criterion (a non-linear function), in this case, the difference between the estimated output and the measured output of the system over a considered time horizon, where the solution is computed by using a numerical interval method. The observer was successfully applied to hydrogen production by R. capsulatus strain B10 in a batch process.     

Stress corrosion cracking mechanisms of alloy 600 polycrystals and single crystals in primary water—Influence of hydrogen

This article investigates the mechanisms governing the process of alloy 600 stress corrosion cracking (SCC). Several critical points have been selected. First, the deleterious influence of cathodic polarization on alloy 600 SCC resistance has been assessed by slow strain rate tests (SSRTs) in primary water at 360 °C. The effects on crack initiation and propagation have been distinguished. Second, a global hydrogen embrittlement of alloy 600 has also been studied at different temperatures from 25 °C to 360 °C. Finally, the use of alloy 600 single crystals allowed clear separation of the crack initiation and crack propagation mechanisms. Transgranular SCC propagation has been precisely observed and described. The possible mechanisms for SCC initiation and propagation on polycrystals are then discussed.     

On the discovery of novel wordlike units from utterances: An artificial-language study with implications for native-language acquisition.

In 4 experiments, adults were familiarized with utterances from an artificial language. Short utterances occurred both in isolation and as part of a longer utterance, either at the edge or in the middle of the longer utterance. After familiarization, participants' recognition memory for fragments of the long utterance was tested. Recognition was greatest for the remainder of the longer utterance after extraction of the short utterance, but only when the short utterance was located at the edge of the long utterance. These results support the incremental distributional regularity optimization (INCDROP) model of speech segmentation and word discovery, which asserts that people segment utterances into familiar and new wordlike units in such a way as to minimize the burden of processing new units. INCDROP suggests that segmentation and word discovery during native-language acquisition may be driven by recognition of familiar units from the start, with no need for transient bootstrapping mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proteomic characterisation of subclover seed storage proteins during germination

BACKGROUND: Early seedling development is a critical step in the establishment of subclover (Trifolium subterraneum), an economically important and widespread pasture legume. In this study the seed storage proteome of this non‐model species was characterised in mature dry seeds and during imbibition by using two‐dimensional electrophoresis coupled with tandem mass spectrometry. RESULTS: The phenol‐extracted proteome of subclover dry seeds consisted of 97 polypeptide spots displayed within a window of pI 3–10 and molecular mass 10–150 kDa. De novo sequencing coupled with MS BLAST search enabled the confident identification of 61 proteins, which corresponded to 59 7S vicilin‐ and two 11S legumin‐type globulins. The experimental mobility of vicilin isoforms along with peptide mapping indicated that low‐molecular‐mass polypeptides might account for the post‐translational proteolysis of small vicilin subunits according to the model described for those of pea. Analysis of quantitative changes in the seed storage proteome upon imbibition showed that vicilin catabolism according to a site‐specific process was favoured during early seedling growth in T. subterraneum. CONCLUSION: The establishment of a seed proteome map for T. subterraneum pointed to vicilins as dominant proteins in mature seeds whose catabolism features during early seedling growth may be of relevance under environmental conditions. Copyright © 2009 Society of Chemical Industry     

Biological diagnosis of premature rupture of membranes: respective values of diamine oxidase activity compared to vaginal fluid pH (Amnicator)

OBJECTIVES: To compare the sensitivity (Se), specificity (Spe), positive predictive (PPV) and negative predictive (PNV) values of 2 tests used routinely for suspected premature rupture of the membranes (PROM) and their implication in the management of such cases. PATIENTS AND METHODS: From 1 November 1995 to 31 July 1996, 87 patients: 16 with obvious PROM on physical examination (group I) and 71 with suspected PROM (group II) were tested with both DAO and Amnicator. PROM was arbitrary confirmed in group II when delivery occurred within 48 hours after the diagnosis was suspected. The corrected chi 2 test was used to compare both tests results in group II. RESULTS: In case of obvious PROM, the sensitivity of the DAO and Amnicator tests were 75 and 87.5% respectively. Eleven patients from group II delivered within 48 hours following admission and the 2 tests results were respectively: Se 90.9 and 81.81%, Spe 100 and 83.33%, PPV 100 and 52.63% and PNV 98.36 and 96.15%. DAO gave better results in terms of Spe and PPV (p < 0.05). COMMENTS: The DAO test remains a reference test when PROM is suspected but when it is not available (during night or week-end), the quite good negative predictive value of Amnicator could avoid unnecessary hospitalisation and permit later DAO test.     

An MTP inhibitor that normalizes atherogenic lipoprotein levels in WHHL rabbits

Patients with abetalipoproteinemia, a disease caused by defects in the microsomal triglyceride transfer protein (MTP), do not produce apolipoprotein B-containing lipoproteins. It was hypothesized that small molecule inhibitors of MTP would prevent the assembly and secretion of these atherogenic lipoproteins. To test this hypothesis, two compounds identified in a high-throughput screen for MTP inhibitors were used to direct the synthesis of a highly potent MTP inhibitor. This molecule (compound 9) inhibited the production of lipoprotein particles in rodent models and normalized plasma lipoprotein levels in Watanabe-heritable hyperlipidemic (WHHL) rabbits, which are a model for human homozygous familial hypercholesterolemia. These results suggest that compound 9, or derivatives thereof, has potential applications for the therapeutic lowering of atherogenic lipoprotein levels in humans.     

Optimizing a wet granulation process to obtain high-dose sustained-release tablets with Compritol 888 ATO

Context: Niacin (vitamin B3) is a micronized active pharmaceutical ingredient (API) with poor flow properties making the production of high-dose sustained-release tablets by direct compression a challenge.

Objective: We evaluated various wet granulation processes as a simple and efficient approach to obtain high-dose (500 and 1000?mg) niacin sustained-release lipid matrix tablets.

Materials and methods: A high melting-point lipid (Compritol® 888 ATO) was used as the sustained-release agent. Tablets were prepared by various wet granulation techniques, with different process parameters and binder concentrations to identify the optimal process conditions.

Results: A binder (PVP) was needed to increase particle bonding and tablet strength. Process parameters, such as spray rate and quantity of liquid, had only a slight impact on the properties of the granules and resultant tablets, in the presence of low binder concentrations. Increasing binder concentration improved granule wetting, resulting in significant granule growth and improved flow properties. Sustained-release over 12?h was observed for all the compacted granules, irrespective of the drug dose. The sustained-release kinetics for 1000?mg niacin matrix tablets with Compritol 888 produced with the identified optimal parameters were similar to those for the market reference product, Niaspan® FCT 1000?mg. The tablets were stable for up to six months when stored at 25 and 40?°C.

Conclusions: Wet granulation with Compritol 888 presents an effective approach to improve material flow and compressibility. High-dose lipid matrix tablets with sustained release profiles can be successfully produced.     

Persistence and prevalence of pathogenic and extended-spectrum beta-lactamase-producing Escherichia coli in municipal wastewater treatment plant receiving slaughterhouse wastewater

We compared the prevalence of pathogenic and extended-spectrum beta-lactamase (ESBL) – producing Escherichia coli in effluents of a municipal wastewater treatment plant (WWTP) receiving wastewater from a slaughterhouse. A total of 1248 isolates were screened for the presence of virulence genes associated with enterohemorrhagic E. coli (EHEC) (stx₁, stx₂, and eae) and extraintestinal pathogenic E. coli (ExPEC) (sfa/focDE, kpsMT K1, hlyA, papEF, afa/draBC, clbN, f17A and cnf). The prevalence of atypical enteropathogenic E. coli (EPEC) was 0.7%, 0.2% and 0.5% in city wastewater, slaughterhouse wastewater and in the treated effluent, respectively. One stx_1a and stx_2b-positive E. coli isolate was detected in city wastewater. The prevalence of ExPEC was significantly higher in city wastewater (8.4%), compared to slaughterhouse wastewater (1.2%). Treatment in the WWTP did not significantly impact the prevalence of ExPEC in the outlet effluent (5.0%) compared to city wastewater. Moreover, the most potentially pathogenic ExPEC were isolated from city wastewater and from the treated effluent. ESBL-producing E. coli was also mainly detected in city wastewater (1.7%), compared to slaughterhouse wastewater (0.2%), and treated effluent (0.2%). One ESBL-producing E. coli, isolated from city wastewater, was eae-β1 positive. These results showed that pathogenic and/or ESBL-producing E. coli were mainly detected in human wastewater, and at a lesser extend in animal wastewater. Treatment failed to eliminate these strains which were discharged into the river, and then these strains could be transmitted to animals and humans via the environment.     

Integrated Routing and Storage for Messaging Applications in Mobile Ad Hoc Networks

This paper is motivated by the observation that traditional ad hoc routing protocols are not an adequate solution for messaging applications (e.g., e-mail) in mobile ad hoc networks. Routing in ad hoc mobile networks is challenging mainly because of node mobility – the more rapid the rate of movement, the greater the fraction of bad routes and undelivered messages. For applications that can tolerate delays beyond conventional forwarding delays, we advocate a relay-based approach to be used in conjunction with traditional ad hoc routing protocols. This approach takes advantage of node mobility to disseminate messages to mobile nodes. The result is the Mobile Relay Protocol (MRP), which integrates message routing and storage in the network; the basic idea is that if a route to a destination is unavailable, a node performs a controlled local broadcast (a relay) to its immediate neighbors. In a network with sufficient mobility – precisely the situation when conventional routes are likely to be non-existent or broken – it is quite likely that one of the relay nodes to which the packet has been relayed will encounter a node that has a valid, short (conventional) route to the eventual destination, thereby increasing the likelihood that the message will be successfully delivered. Our simulation results under a variety of node movement models demonstrate that this idea can work well for applications that prefer reliability over latency.