Counteracting Recontamination of Pasteurized Milk by Methylated Soybean Protein

Methylated soy protein (MSP) was evaluated as an antimicrobial agent that can counteract the potential post-pasteurization contamination of milk during a 30-day cold storage (4 °C) or 24-h room temperature storage (25 °C) as compared to its native form (SP). SP and MSP were added to buffalo milk at 0.5% (w/v) after pasteurization and before storage. Milk microbiological and chemical analyses were carried out either directly to follow the spontaneous microbial contamination or after artificial contamination with three pathogens (Escherichia coli O157:H7, Listeria monocytogenes Scott A, and Salmonella enterica subsp. enterica serovar Enteritidis PT4). Supplementation of milk samples with MSP (0.5%) significantly (p?<?0.05) and considerably inhibited the levels of the spontaneously proliferating bacterial counts, i.e., total viable and Enterobacteriaceae counts were inhibited by about 2.5 log CFU mL^?1, while psychrotrophic and pseudomonads counts were inhibited by 1.8 and 1.6 log CFU mL^?1, respectively, after 16 days of preservation at 4 °C. Similar trend of effects were also produced after 12–18 h of milk storage at 25 °C. MSP (0.5%) nearly hindered the proliferation of the three inoculated pathogens in pasteurized milk during 16 days of storage at 4 °C or 12–18-h storage at 25 °C. Based on milk acidity, SDS–PAGE pattern, and microbiological analysis, it is concluded that supplementation with MSP (0.5%) can prolong the shelf life of pasteurized milk from 6 to 16 days when stored under cold conditions and from 8 to 18 h under room temperature conditions.     

Conversion of pentahalogenated phenols by microperoxidase-8/H2O2 to benzoquinone-type products

This study reports the microperoxidase-8 (MP8)/H2O2-catalyzed dehalogenation of pentafluorophenol and pentachlorophenol, compounds whose toxic effects and persistence in the environment are well documented. The primary products of this dehalogenation reaction appear to be the corresponding tetrahalo-p-benzoquinones. Under the conditions used, the fluorinated phenol and its intermediate products are more susceptible to degradation than the corresponding chlorinated analogue and its products. The main degradation products of tetrachloro-p-benzoquinone and tetrafluoro-p-benzoquinone were identified as trichlorohydroxy-p-benzoquinone and trifluorohydroxy-p-benzoquinone, respectively. This secondary conversion of tetrafluoro-p-benzoquinone and tetrachloro-p-benzoquinone was not mediated by MP8, but was driven by H2O2. Evidence is presented for a mechanism where H2O2 molecules and not hydroxide anions are the reactive nucleophilic species attacking the tetrahalo-p-benzoquinones. In addition to the formation of the trihalohydroxy-p-benzoquinones, the formation of adducts of the tetrahalo-p-benzoquinone products with ethanol, present in the incubation medium, was observed. The adduct from the reaction of tetrachloro-p-benzoquinone with ethanol was isolated and identified as trichloroethoxyquinone. Thus, the present paper describes a system in which the formation of tetrahalo-p-benzoquinone-type products by an oxidative heme-based catalyst could be unequivocally demonstrated.     

Molecular studies on bromovirus capsid protein

Brome mosaic bromovirus (BMV) and cucumber mosaic cucumovirus (CMV) are structurally and genetically very similar. The specificity of the BMV and CMV coat proteins (CPs) during in vivo encapsidation was studied using two RNA3 chimera in which the respective CP genes were exchanged. The replicative competence of each chimera was analyzed in Nicotiana benthamiana protoplasts, and their ability to cause infections was examined in two common permissive hosts, Chenopodium quinoa and N. benthamiana. Each RNA3 chimera replicated to near wild-type (wt) levels and synthesized CPs of expected parental origin when co-inoculated with their respective genomic wt RNAs 1 and 2. However, inoculum containing each chimera was noninfectious in the common permissive hosts tested. Encapsidation assays in N. benthamiana protoplasts revealed that CMV CP expressed from chimeric BMV RNA3 was capable of packaging heterologous BMV RNA, however, at a lower efficiency than parental BMV CP. By contrast, BMV CP expressed from chimeric CMV RNA3 was unable to package heterologous CMV RNA. These observations demonstrate that BMV CP, but not CMV CP, exhibits a high degree of specificity during in vivo packaging. The reasons for the noninfectious nature of each chimera in the host plants tested and factors likely to affect encapsidation in vivo are discussed.     

A fuzzy logic supervisor for active and reactive power control of a variable speed wind energy conversion system associated to a flywheel storage system

In this paper, we propose a Wind Energy Conversion System (WECS) at variable speed using a Doubly Fed Induction Generator (DFIG) controlled on the rotor side through converters. A Flywheel Energy Storage System (FESS) is connected to the studied wind generator at the DC bus in order to evaluate its capacity to participate to the ancillary services. We study the improvement of the active and reactive power quality produced by the wind generator and its effect on the load voltage regulation connected to the wind generator. For that, a fuzzy logic supervisor is established to control the FESS operation and the DC bus voltage in order to smooth the active power fluctuations due to the random wind speed variations. A control law is also described to smooth the reactive power at the connection node to the grid.     

Formulation of blended cement: Effect of process variables on clay pozzolanic activity

Chemical, physical and mineralogical properties of crude and calcined local kaolinitic clay were studied in detail in order to use it as an artificial pozzolan. The aim of this study was to investigate and optimize the properties of mortars in which calcined clay is employed as a pozzolan.A three variable (calcination time: X1, calcination temperature: X2 and % of calcined clay in the blended cement: X3) rotatable orthogonal composite design was set up. It was concluded that the compressive strengths were governed by the calcination temperature and the percentage of the calcined clay in the blended cement. It was proven that the strengths could be improved by increasing simultaneously the percentage of incorporation and the calcination temperature of the clay. It was also demonstrated that at temperatures lower than 700 °C, the increase of the calcination time, improved the compressive strength, while above 700 °C, the opposite effect was observed. Finally, a blended cement composition has been formulated and optimized using the desirability functions. The optimized blended cement contains 25% of calcined clay, heated for 3 h at a temperature of 750 °C.     

Ultimate strain of stiffened steel box sections under bending moment and axial force fluctuations

The influence of axial force fluctuations on the ductility of short steel cylinders has been previously reported by the authors, together with a proposal for a design formula that takes this influence into account. The present paper describes a similar investigation for stiffened short steel box columns. Elastoplastic large-displacement analysis of parametric short steel box columns is carried out and the bending behavior under constant and fluctuating axial forces is compared. The maximum value of axial force fluctuation is taken to be the same as the axial force magnitude in the constant axial force case. It is found that ductile capacity corresponding to the post-peak region of the bending behavior is improved to different degrees depending on the magnitude and amount of fluctuation of the axial force, a finding that is similar to that for short steel cylinders. Design formulae for failure strain taking this improvement into account are proposed for two different limit states and their validity is demonstrated through numerical analysis.     

S-phase-specific activation of Cds1 kinase defines a subpathway of the checkpoint response in Schizosaccharomyces pombe

Checkpoints that respond to DNA structure changes were originally defined by the inability of yeast mutants to prevent mitosis following DNA damage or S-phase arrest. Genetic analysis has subsequently identified subpathways of the DNA structure checkpoints, including the reversible arrest of DNA synthesis. Here, we show that the Cds1 kinase is required to slow S phase in the presence of DNA-damaging agents. Cds1 is phosphorylated and activated by S-phase arrest and activated by DNA damage during S phase, but not during G1 or G2. Activation of Cds1 during S phase is dependent on all six checkpoint Rad proteins, and Cds1 interacts both genetically and physically with Rad26. Unlike its Saccharomyces cerevisiae counterpart Rad53, Cds1 is not required for the mitotic arrest checkpoints and, thus, defines an S-phase specific subpathway of the checkpoint response. We propose a model for the DNA structure checkpoints that offers a new perspective on the function of the DNA structure checkpoint proteins. This model suggests that an intrinsic mechanism linking S phase and mitosis may function independently of the known checkpoint proteins.     

Neural classifiers and statistical pattern recognition:applications for currently established links

Recent research has linked backpropagation (BP) and radial basis function (RBF) network classifiers, trained by minimizing the standard mean square error (MSE), to two main topics in statistical pattern recognition (SPR), namely the Bayes decision theory and discriminant analysis. However, so far, the establishment of these links has resulted in only a few practical applications for training, using, and evaluating these classifiers. The paper aims at providing more of these applications. It first illustrates that while training a linear output BP network, the explicit utilization of the network discriminant capability leads to an improvement in its classification performance. Then, for linear output BP and RBF networks, the paper defines a new generalization measure that provides information about the closeness of the network classification performance to the optimal performance. The estimation procedure of this measure is described and its use as an efficient criterion for terminating the learning algorithm and choosing the network topology is explained. The paper finally proposes an upper bound on the number of hidden units needed by an RBF network classifier to achieve an arbitrary value of the minimized MSE. Experimental results are presented to validate all proposed applications.     

Paragonimiasis: a rare little known disease

BACKGROUND: Paragonimiasis, caused by a lung fluke, is an parasitic disease rarely encountered in France. CASE REPORT: A 52-year-old man developed dyspnea, cough, mild fever and chest pain. Pleural effusion suggested possible pulmonary embolism or tuberculosis. Cell counts in blood and pleural effusion fluid revealed major eosinophila in this patient who had recently returned from a trip to Japan. Paragonimiasis was confirmed by ELISA. Treatment with praziquantel led to complete clinical and radiographic recovery. DISCUSSION: The clinical and radiographic features of paragonimiasis are often similar to tuberculosis with pleuropneumopathy, mild fever and dyspnea. ELISA has now replaced parasitologic diagnosis. Cure is achieved with praziquantel.     

Coronary flow and flow reserve in canines using MR phase difference and complex difference processing

Coronary artery disease continues to be the leading cause of death for adults in the United States. Magnetic resonance imaging (MR) has the potential to dramatically impact the diagnosis of heart disease by noninvasively providing a wide range of anatomic and physiologic information. Previous research has shown that coronary flow, one component of a complete examination, can be accurately measured in the left anterior descending artery in vivo. The current work validates MR flow measurements in canine circumflex arteries using transit time ultrasound as a standard. The circumflex artery experiences greater in-plane motion and is a more stringent test for flow measurement accuracy. This work also compares two methods of processing MR velocity data, phase difference and complex difference techniques, and examines the sources of error present in the animal validation model. Phase difference processing with a 30% magnitude threshold best matched the mean ultrasound flow values (30% PD = 1.04 x US + 1.49, r = 0.94), but it was very sensitive to vessel boundary identification. The complex difference process was less sensitive to vessel boundary identification and correlated well with the transit time ultrasound despite systematic underestimations. The reasons for the discrepancies are shown to stem from a number of possible sources including variability of the ultrasound standard, low signal-to-noise ratios in the MR images, sensitivity of the MR technique to vessel boundary identification, and motion artifacts in the images.