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The aim of this paper is to estimate the parameters of a counterflow heat exchanger in the case where the dynamics are described by a system of two hyperbolic partial differential equations (PDEs). This study is performed using data collected on a laboratory test bench. First we study the practical identifiability of the system, the objective of which is to verify the possibility of determining the parameters of the system in a unique way from the available data. Next the parameter estimation is performed by a nonlinear optimization method, typically by the Levenberg-Marquardt algorithm on a set of ordinary differential equations obtained from the reduction of the original PDEs by the method of lines. Since the Levenberg-Marquardt algorithm may only converge with a reasonable estimate of the parameters, we first consider a least squares parameter estimation approach based on the global difference model. Finally, the results of this Identification are validated by using laboratory data, and by verifying some statistical properties.

In this paper we are interested in the thermodynamic analysis of a counterflow heat exchanger, when the dynamics are described by two hyperbolic partial differential equations (PDEs). First from the first and second law of thermodynamics we derive the different models of the heat exchanger. Next we perform an analysis of the equilibrium profiles from a certain condition on the system parameters that guarantees the existence and uniqueness of the solution of the PDEs model. In this analysis we show the importance of the thermal pinch as an energy efficiency factor. Finally we study the passivity and the asymptotic stability of the considered heat exchanger essentially basing ourselves on the entropy as a storage function, entropy production as a dissipation function, and the thermodynamic availability function as a Lyapunov function.

Heat exchangers are generally described by two coupled partial differential equations (PDEs), and belong to the class of systems of conservation laws. In this paper we propose a result on the regulation of heat exchangers, in which we are choosing a proportional-integral (PI)-controller implemented on an output feedback from a boundary condition. First, a study on the existence and uniqueness of solutions of uncontrolled system is carried out, and we give a condition on the parameters of the system that ensures that the control-observation problem is well-posedness. Secondly we successively study the stability of the system controlled by a proportional and integral action, when the gains are adjusted following respectively a classic Lyapunov approach, and using a recent result that combines Lyapunov's approach and operator perturbation theory.

This paper presents a sliding mode observer (SMO) for estimating temperatures in a heat exchanger. First a port-Hamiltonian formulation for a countercurrent heat exchanger is proposed. It is so as to guarantee convergence of the observer. It is shown that the Stokes-Dirac structure obtained by opening only the dissipation ports due to the convection phenomenon, is conservative. Secondly, a SMO based on an interconnected structure of port-Hamiltonian systems is designed. The convergence of the dynamics of the estimation error is proven. The simulation results illustrate the effectiveness of this estimation strategy.

HIV programmes face challenges achieving high rates of HIV testing and treatment needed to optimise health and to reduce transmission. We used data from the Botswana Combination Prevention Project study survey to assess Botswana's progress toward achieving UNAIDS targets for 2020: 90% of all people living with HIV knowing their status, 90% of these receiving sustained antiretroviral therapy (ART), and 90% of those having virological suppression (90-90-90).

In this article, the authors consider the basic problem of recommender systems that is identifying a set of users to whom a given item is to be recommended. In practice recommender systems are run against huge sets of users, and the problem is then to avoid scanning the whole user set in order to produce the recommendation list. To cope with problem, they consider that users are connected through a social network and that taxonomy over the items has been defined. These two kinds of information are respectively called social and semantic information. In their contribution the authors suggest combining social information with semantic information in one algorithm in order to compute recommendation lists by visiting a limited part of the social network. In their experiments, the authors use two real data sets, namely Amazon.com and MovieLens, and they compare their algorithms with the standard item-based collaborative filtering and hybrid recommendation algorithms. The results show satisfying accuracy values and a very significant improvement of performance, by exploring a small part of the graph instead of exploring the whole graph.

This paper discusses the possibilities of applying Virtual Reality (VR) technologies to Manufacturing Engineering, and in particular assesses its role in the Factory of the Future (FoF). We review, classify and compare the recommendations given by four major European reports on the challenges that have to be met for a successful deployment of the FoF, and we identify the potential contributions of VR to this vision in terms of new technologies, worker-factory relationship, modular infrastructure and production efficiency. We argue that VR can be a key technology to support the FoF at all levels of the Systems Engineering approach, either directly by applying it in standard engineering processes, or indirectly by leveraging other useful technologies.

Cloud computing is a fast growing technology allowing companies to use on-demand computation, and data services for their everyday needs. The main contribution of this work is to propose a new model of genetic algorithm for the workflow scheduling problem. The algorithm must be capable of: 1) dealing with the multi-objective problem of optimising several quality of service (QoS) variables, namely: computation time, cost, reliability or security; 2) handling a large number of workflow scheduling aspects such as adding constraints on QoS variables (deadlines and budgets); 3) handling hard constraints such as restrictions on task scheduling that the previous algorithms have not addressed. Using data from Amazon elastic compute cloud (EC2) and workflows from the London e-Science Centre; we have compared our algorithm with other scheduling algorithms. Simulation results indicate the efficiency of the proposed metaheuristic both in terms of solution quality and computational time.

It has become increasingly apparent that the ability to generate an optimal host immune response requires effective cross talk between the innate and adaptive components of the immune system. Pro-inflammatory cytokines, in particular those that can induce a danger signal, often called signal 3, are crucial in this role of initiating and augmenting the presentation of exogenous antigen to T cells by dendritic cells. Interleukin-12 (IL-12) in particular has been defined as a "signal 3" cytokine required for the antigen cross priming. Given this unique interactive function, a significant amount of work has been performed to define possible therapeutic applications for IL-12. Systemic IL-12 administration can clearly act as a potent adjuvant for postvaccination T cell responses in a variety of diseases. As an example, in the cancer setting, systemic IL-12 is capable of suppressing tumor growth, metastasis, and angiogenesis in vivo. IL-12, however, has been associated with significant dose- and schedule-dependent toxicity in early clinical trials, results that have proven to be a major obstacle to its clinical application. Recent research has focused on decreasing the toxicity of IL-12 using different delivery approaches, including virus-based and gene-modified cell-based delivery. Although effective, these approaches also have limitations, including the generation of neutralizing antibodies, in addition to lacking the simplicity and versatility required for universal clinical application. Thus, there is a significant interest in the development of alternative delivery approaches for IL-12 administration that can overcome these issues. Several nonviral delivery approaches for IL-12 protein or gene expression vectors are being defined, including alum, liposomes, and polymer-based delivery. These developing approaches have shown promising adjuvant effects with significantly lessened systemic toxicity. This article discusses the potential capabilities of these nonvirus-based IL-12 delivery systems in different disease settings, including allergy, infection, and cancer.

Leishmania amazonensis is one of the major etiologic agents of a broad spectrum of clinical forms of leishmaniasis and has a wide geographical distribution in the Americas, which overlaps with the areas of transmission of many other Leishmania species. The LACK and A2 antigens are shared by various Leishmania species. A2 was previously shown to induce a potent Th1 immune response and protection against L. donovani infection in BALB/c mice. LACK is effective against L. major infection, but no significant protection against L. donovani infection was observed, in spite of the induction of a potent Th1 immune response. In an attempt to select candidate antigens for an American leishmaniasis vaccine, we investigated the protective effect of these recombinant antigens (rLACK and rA2) and recombinant interleukin-12 (rIL-12) against L. amazonensis infection in BALB/c mice. As expected, immunization with either rA2-rIL-12 or rLACK-rIL-12 induced a robust Th1 response prior to infection. However, only the BALB/c mice immunized with rA2-rIL-12 were protected against infection. Sustained gamma interferon (IFN-gamma) production, high levels of anti-A2 antibodies, and low levels of parasite-specific antibodies were detected in these mice after infection. In contrast, mice immunized with rLACK-rIL-12 displayed decreased levels of IFN-gamma and high levels of both anti-LACK and parasite-specific antibodies. Curiously, the association between rA2 and rLACK antigens in the same vaccine completely inhibited the rA2-specific IFN-gamma and humoral responses and, consequently, the protective effect of the rA2 antigen against L. amazonensis infection. We concluded that A2, but not LACK, fits the requirements for a safe vaccine against American leishmaniasis.

ABSTRACTLeishmania amazonensisis one of the major etiologic agents of a broad spectrum of clinical forms of leishmaniasis and has a wide geographical distribution in the Americas, which overlaps with the areas of transmission of many other Leishmaniaspecies. The LACK and A2 antigens are shared by various Leishmaniaspecies. A2 was previously shown to induce a potent Th1 immune response and protection against L. donovaniinfection in BALB/c mice. LACK is effective against L. majorinfection, but no significant protection against L. donovaniinfection was observed, in spite of the induction of a potent Th1 immune response. In an attempt to select candidate antigens for an American leishmaniasis vaccine, we investigated the protective effect of these recombinant antigens (rLACK and rA2) and recombinant interleukin-12 (rIL-12) against L. amazonensisinfection in BALB/c mice. As expected, immunization with either rA2-rIL-12 or rLACK-rIL-12 induced a robust Th1 response prior to infection. However, only the BALB/c mice immunized with rA2-rIL-12 were protected against infection. Sustained gamma interferon (IFN-γ) production, high levels of anti-A2 antibodies, and low levels of parasite-specific antibodies were detected in these mice after infection. In contrast, mice immunized with rLACK-rIL-12 displayed decreased levels of IFN-γ and high levels of both anti-LACK and parasite-specific antibodies. Curiously, the association between rA2 and rLACK antigens in the same vaccine completely inhibited the rA2-specific IFN-γ and humoral responses and, consequently, the protective effect of the rA2 antigen against L. amazonensisinfection. We concluded that A2, but not LACK, fits the requirements for a safe vaccine against American leishmaniasis.

The Unified Process (UP) is an OMG standard. This Process is driven by UML use cases and architecture. UP proposes some disciplines but not enough to cope all the needs of the enterprises. One of these needs is the composition. In this paper, we shortly present UP and principles of our methodology named Extended Unified Process (EUP). EUP adds to UP a specific architecture discipline including a process for composition. This paper is an overview of this process. [Copyright &y& Elsevier]

Background: Generic antimalarial drugs sold in sub-Saharan Africa require tighter control as counterfeiting has grown more and more out of control. The study aimed to analyze the pharmaceutical quality of quinine sulfate (QS) and Artemether/Lumefantrine(AL) tablets marketed in Bukavu city compared to the current trends in other African cities. Results: The samples were purchased in community pharmacies or from ambulatory street vendors and analyzed using a set of thirteen simple tests, including visual inspection, UV spectrometry, TLC, and conventional quality control procedures. More than 93% of AL samples had an acceptable global quality score of > 90%. Around 16.6% of QS batches did not satisfy the requirements about hardness, friability, and mass uniformity. Only 33.3% met the disintegration quality; 33.3% did not contain quinine; 8.33% had an active ingredient other than quinine. Conclusion: The findings strongly alert the circulation of fake antimalarial medicines observed in many countries. Simple TLC procedures may help to detect any low-quality generics to avoid microbial resistance and guarantee the health of the population. Pharmacists and regulatory authorities are alerted to the circulation of low-quality generic quinine preparations in the country.

Background: The Chenopodiumgenus is a plant family widely spread worldwide that includes various plant species reputed to possess several medicinal virtues in folk medicines. Chenopodium ambrosioidesL. is among the most used plants in traditional medicines worldwide. This review aimed to highlight ethnomedicinal uses, phytochemical status, and pharmacological properties of C. ambrosioidesL. Main body of the abstract: The analysis of relevant data highlights various ethnomedicinal uses against human and veterinary diseases in forty countries. Most indications consisted of gastrointestinal tract dysfunctioning troubles and worms parasitemia. Around 330 chemical compounds have been identified in different plant parts, especially in its essential oil fractions (59.84%). However, only a few compounds—mainly monoterpenes and glycosides—have been isolated and characterized. Experimental pharmacological studies validated a large scale of significant health benefits. It appeared that many monoterpenes are antioxidant, insecticidal, trypanocidal, analgesic, antifungal, anti-inflammatory, anti-arthritic, acaricidal, amoebicidal, anthelmintic, anticancer, antibacterial, antidiabetic, antidiarrheal, antifertility, antifungal, anti-leishmanial, antimalarial, antipyretic, antisickling, antischistosomal, antiulcer, anxiolytic, immunomodulatory, molluscicidal, and vasorelaxant agents. Short conclusion: Thus, the Chenopodium ambrosioidesspecies necessitates further chemical studies to isolate and characterize new bioactive secondary metabolites and pharmacological investigations to precise the mechanisms of action before clinical trials.

Stem Canker caused by Diaporthe phaseolorum(Cooke & Ellis) Sacc. var. caulivoraK. L. Athow & R. M. Caldwell (Dpc) has become a serious disease of soybean [Glycine max(L.) Merr.] throughout the southeastern USA. Sources of resistance have been identified and information on the inheritance of resistance is needed for each source. The objective of this work was to study the inheritance of resistance to stem canker in ‘Crockett’ and ‘Dowling’ soybean. Crockett, Dowling, and ‘Tracy‐M’ were crossed with each other and with two susceptible cultivars, Coker 338 and Johnston. Disease reactions of parent and progeny populations were studied in the greenhouse following artificial (toothpick) incoculation with a southern isolate of Dpc. Crosses between either Dowling or Crockett and the two susceptible parents resulted in segregating F2populations that fit a 3 resistant : 1 susceptible ratio, and F2:3families that fit a 1 resistant : 2 segregating : 1 susceptible ratio. The cross between Crockett and Dowling resulted in a 15:1 ratio in the F2and a 7:8:1 ratio in the F3generation. Crosses between Tracy‐M and Crockett or Dowling resulted in segregation ratios of 63:1 in the F2and 37:26:1 and F3. These results suggest that Crockett and Dowling each have a major dominant gene, and that these two genes are different from RdC1and RdC2found in Tracy‐M. The gene symbols Rdc3and Rdc4are proposed to identify genes controlling resistance to stem canker in Crockett and Dowling, respectively.

Summary Chloroperoxidase is an extracellular heme glycoprotein produced by the imperfect fungusCaldariomyces fumago. The enzyme can catalyse chlorination reactions as well as act as a catalase or a peroxidase. As a peroxidase, it has a wide substrate specificity and we are interested in some applied aspects of this activity, requiring the production and purification of moderate quantities of the enzyme. High levels of chloroperoxidase are produced in a fructose synthetic medium, and highest enzyme production occurs in a low-shear environment. fungal pellets produce enzyme continuously at low medium replacement rates and at up to 0.6 g enzyme per 1: chloroperoxidase is essentially the only extracellular enzyme produced. Enzyme purification is uncomplicated and gives good yields of high purity. Pure enzyme is stable for weeks at room temperature and under pH control. Chloroperoxidase can be ionically bound to aminopropyl glass, then covalently immobilized by glutaraldehyde crosslinking. Immobilized preparations have been washed and re-used five times, and are most stable at pH 5.5-6. Like many peroxidases, chloroperoxidase will oxidize phenols and phenolics, often causing a precipitate, and can totally remove phenols at low aqueous concentrations. Chloroperoxidase incubation with the petroporphyrin component of crude oil asphaltene (fraction 5) causes a reduction or removal of the Soret band (410 nm) and the a-peak (573 nm). This petroporphyrin fraction is enriched with vanadium which poisons the chemical catalyst used in cracking crude oil.

Summary d-(l-a-Aminoadipyl)-l-cysteinyl-d-valine (ACV)-synthetase fromStreptomyces clavuligerus was studied under conditions that enabled the reuse of the enzyme. Coupling of ACV-synthetase to DEAE-Trisacryl and aminopropyl-glass resulted in an immobilized enzyme product of little or no catalytic activity. However, an enzyme reactor was designed by physical confinement of partially-purified ACV-synthetase in an ultrafiltration cell. This system was stimulated by phosphoenolpyruvate at lower concentrations of ATP, an effect not observed with purified enzyme. Up to 30% conversion of the limiting substrate, cysteine, to ACV occurred under semi-continuous conditions. Reaction products were investigated as potential inhibitors: AMP was the most inhibitory, but only when used at concentrations in excess of those produced in reaction mixtures. Under a nitrogen atmosphere, both product and enzyme stabilities were greatly improved and the enzyme retained 45–46% of its initial activity after five uses at room temperature during a 24-h period. Extrapolations based on these data suggest that 1.3 g partially purified enzyme (0.13 U g-1) would be capable of producing 411 mg of ACV in a 1-L reaction mixture in this period.

Summary ϖ-(l-α-Aminoadipyl)-l-cysteinyl-d-valine (ACV)-synthetase is a key enzyme that channels primary metabolites to a tripeptide common to cephalosporin and cephamycin biosynthesis inStreptomyces clavuligerus. Time-course studies indicated that theS. clavuligerus ACV-synthetase was stable during the cephamycin C fermentation: the enzyme was produced early in the growth phase and its activity remained high up to 96 h of growth. The detection of crude ACV-synthetase activity in older cultures was best achieved with an assay medium supplemented with 5 mM phosphoenolpyruvate, at lower ATP concentrations. During storage at 4°C, a progressive decrease in the stability of crude ACV-synthetase was observed with increasing culture age. Although a proteinolytic activity with a pH optimum at 8.2 was detected in crude cell-free extracts, no significant variation was observed in its activity with increasing culture age to account for the instability of ACV-synthetase in vitro. Addition of proteinase inhibitors did not improve the stability of the enzyme. However, a stabilization cocktail containing dithiothreitol. MgCl2, the three substrate amino acids, and glycerol increased the stability of the enzyme isolated from cultures grown for 30–40 h, which was shortly after the appearance of antibiotics in the culture fluid. This stabilized enzyme retained half of its initial activity after 6 days at 4°C.

The TLC isolation as well as the mass spectrometric identification of gitoxin metabolites excreted in bile are described.

Resistance to piperacillin in several isolates of Citrobacter freundii and Enterobacter cloacae was investigated and confirmed to occur at a frequency of 10(-7) to 10(-6). Development of resistance to piperacillin was significantly suppressed by tazobactam but not by clavulanic acid. To elucidate the mechanism by which resistance suppression occurs, the effect of piperacillin plus tazobactam on the induction of AmpC beta-lactamase was analyzed by monitoring the beta-galactosidase activity of an inducible ampC-lacZ gene fusion in Escherichia coli. The combination exerted no inhibitory effect on AmpC beta-lactamase induction. Tazobactam also had no effect on the accumulation of a key intermediate in the AmpC beta-lactamase induction pathway, 1,6-anhydromurotripeptide, in an ampD mutant strain of E. coli. However, the addition of tazobactam to liquid cultures of E. cloacae 40001 in the presence of piperacillin at four times the MIC caused a delay in the recovery of the culture to piperacillin-induced stress. At 16 times the MIC, a complete suppression of regrowth occurred. Analysis of culture viability on piperacillin plates showed that the culture recovery was due to growth by moderately resistant mutants preexisting in the cell population, which at 16 times the MIC became susceptible to the combination. Evidence from the kinetics of inhibition of the E. cloacae 40001 AmpC beta-lactamase by clavulanic acid, sulbactam, and tazobactam and from the effects of these drugs on the frequency of resistance to piperacillin suggests that the suppressive effect of tazobactam on the appearance of resistance is primarily mediated by the beta-lactamase inhibitory activity.

Hairy cell leukemia is a rare form of leukemia and has been rarely reported in African and pediatric population.