Peer group image enhancement

Peer group image processing identifies a "peer group" for each pixel and then replaces the pixel intensity with the average over the peer group. Two parameters provide direct control over which image features are selectively enhanced: area (number of pixels in the feature) and window diameter (window size needed to enclose the feature). A discussion is given of how these parameters determine which features in the image are smoothed or preserved. We show that the Fisher discriminant can be used to automatically adjust the peer group averaging (PGA) parameters at each point in the image. This local parameter selection allows smoothing over uniform regions while preserving features like corners and edges. This adaptive procedure extends to multilevel and color forms of PGA. Comparisons are made with a variety of standard filtering techniques and an analysis is given of computational complexity and convergence issues.     

Formulation Protocol and Dicationic Salts Affect Protein Functionality of Model System Beef Batters

ABSTRACT: The objective of this study was to determine if addition, and order of addition, of CaCl₂ and MgCl₂ affected protein functionality of lean beef preblends. Four treatments were applied to non-preblended (NPB) batters prior to thermal processing. Six treatments were applied to preblended (PB) batters 12 h prior to thermal processing. All treatments contained 2% NaCl. Dicationic salts decreased raw pH in NPB and PB batters, while cooked pH was unaffected. Magnesium chloride in NPB and CaCl₂+ MgCl₂ in PB batters resulted in the highest total soluble protein (TSP). Calcium chloride + MgCl₂ in NPB batters resulted in firmer gels compared to the control. Magnesium chloride, in both NPB and PB, caused the greatest increase in soluble myosin, and preblending decreased myosin solubility.     

Cell wall reactivity of acidophilic and alkaliphilic bacteria determined by potentiometric titrations and Cd adsorption experiments

In this study, we used potentiometric titrations and Cd adsorption experiments to determine the binding capacities of two acidophilic (A. cryptum and A. acidophilum) and two alkaliphilic (B. pseudofirmus and B. circulans) bacterial species in order to determine if any consistent trends could be observed relating bacterial growth environment to proton and Cd binding properties and to compare those binding behaviors to those of neutrophilic bacteria. All of the bacterial species studied exhibited significant proton buffering over the pH range in this study, with the alkaliphiles exhibiting significantly higher acidity constants than the acidophiles as well as the neutrophilic bacterial consortia. The calculated average site concentrations for each of the bacteria in this study are within 2σ experimental error of each other, with the exception of A. cryptum, which has a significantly higher Site 2 concentration than the other species. Despite differing acidity constants between the acidophiles and alkaliphiles, all bacteria except A. cryptum exhibited remarkably similar Cd adsorption behavior to each other, and the observed extent of adsorption was also similar to that predicted from a generalized model derived using neutrophilic bacterial consortia. This study demonstrates that bacteria that grow under extreme conditions exhibit similar proton and metal adsorption behavior to that of previously studied neutrophilic species and that a single set of proton and metal binding constants can be used to model the behavior of bacterial adsorption under a wide range of environmental conditions.     

Cryoprotection Affects Physiochemical Attributes of Rainbow Trout Fillets

ABSTRACT: Stabilization of trout myofibrillar proteins during −20°C, 90-d storage and after soaking fillets in water, 8.0% sucrose/sorbitol, or 1.0% sodium lactate was investigated with or without 0.5% phosphate and with or without 0.05% MgCl₂. Fillets not soaked were the control. Compared with the control, cryoprotectants increased total protein and myofibrillar protein solubility; decreased surface hydrophobicity, total, free, and disulfide sulfhydryl content, and myosin susceptibility to thermal denaturation. There were no differences in total protein solubility and actin susceptibility to thermal denaturation between cryoprotectants and the water treatment. Phosphate minimized frozen storage effects on actin solubility and reduced protein surface hydrophobicity and myosin susceptibility to thermal denaturation, while MgCl₂ increased the negative effects of frozen storage.     

Isoelectric fractionation and some properties of a protease from soyabean seeds

A protease, capable of hydrolysing benzoyl DL -arginine p-nitroanilide(BAPA), and L-amino acid β-naphthylamide derivatives, was purified, by isoelectric focusing in the region pH 3–6, from dormant and 6-day germinated soyabean seeds. The enzyme was focused at pH 4·80. The K_m value using BAPA as substrate was found to be 5·03 × 10⁻⁴M . Maximum activity of the enzyme towards BAPA was obtained in the pH 8·2–8–5 region. Slight activation was observed in the presence of 0·05 M concentration of Ca²⁺ and Mg²⁺ ions. The protease lacked caseinolytic activity, and was not inhibited by Kunitz soyabean trypsin inhibitor.     

Survival of Escherichia coli O157:H7 and Salmonella Muenchen on apples as affected by application of commercial fruit waxes

Survival of Escherichia coli O157:H7, Salmonella Muenchen, and yeasts and molds on apples as affected by application of five commercial apple waxes was investigated. Red Delicious cv. apples at 21 degrees C were spot inoculated with E. coli O157:H7 and S. Muenchen and spray coated with waxes. Apples sprayed with water served as controls. Apples were dried at either 21 or 55 degrees C for 2 min before subjecting to microbiological analysis after storage for 0, 1, 3, 6, and 12 weeks at 2 or 21 degrees C. Drying temperature did not significantly influence populations of E. coli O157:H7 and S. Muenchen. Waxing reduced populations E. coli O157:H7 and S. Muenchen by up to 1.48 log10 cfu/apple. Compared to untreated apples, treatment of apples with water or waxes resulted in significant (P < or = 0.05) reductions in populations of E. coli O157:H7 and S. Muenchen during storage at 2 degrees C. Reductions on waxed apples stored at 21 degrees C were not as marked compared to reductions on waxed apples stored at 2 degrees C. With the exception of one wax, drying temperature did not significantly influence populations of yeasts and molds. Mold populations were less affected by wax applications than were yeasts, and were detected in higher numbers on apples treated with three of the five waxes compared to populations recovered from untreated control apples. None of the waxes evaluated can be relied upon to kill or remove E. coli O157:H7 and Salmonella on apples.     

Effectiveness of cleaners and sanitizers in killing Salmonella Newport in the gut of a free-living nematode, Caenorhabditis elegans

Caenorhabditis elegans, a free-living nematode found in soil, has been shown to ingest human enteric pathogens, thereby potentially serving as a vector for preharvest contamination of fruits and vegetables. A study was undertaken to evaluate the efficacy of cleaners and sanitizers in killing Salmonella enterica serotype Newport in the gut of C. elegans. Adult worms were fed nalidixic acid-adapted cells of Escherichia coli OP50 (control) or Salmonella Newport for 24 h, washed, placed on paper discs, and incubated at temperatures of 4 or 20 degrees C and relative humidities of 33 or 98% for 24 h. Two commercial cleaners (Enforce and K Foam Lo) and four sanitizers (2% acetic acid, 2% lactic acid, Sanova, and chlorine [50 and 200 microg/ml]) were applied to worms for 0, 2, or 10 min. Populations of E. coli and Salmonella Newport (CFU per worm) in untreated and treated worms were determined by sonicating worms in 0.1% peptone and surface plating suspensions of released cells on tryptic soy agar containing nalidixic acid. Populations of Salmonella Newport in worms exposed to 33 or 98% relative humidity at 4 degrees or 33% relative humidity at 20 degrees C were significantly (P < or = 0.05) lower than the number surviving exposure to 98% relative humidity at 20 degrees C. In general, treatment of desiccated worms with cleaners and sanitizers was effective in significantly (P < or = 0.05) reducing the number of ingested Salmonella Newport. Results indicate that temperature and relative humidity influence the survival of Salmonella Newport in the gut of C. elegans, and cleaners and sanitizers may not eliminate the pathogen.     

Scintillating Glass, Fiber-Optic Plate Detectors for Active Target and Tracking Applications in High Energy Physics Experiments

We have studied the performance of scintillating glass fiber-optic plates using 10 GeV/c particles at the SLAC test beam. The plates were composed of: (1) Terbium activated cladded-glass cores in a matrix of 15 ?m spacing; and (2) Cerium activated cladded-glass cores in a matrix of variable spacing 6-10 ?m. The target plates were viewed with a three-stage, gatable image intensifier. Particle tracks and nuclear interactions were recorded on film for both materials. We observe 5 detected hits/mm for minimum ionizing particles for the Tb glass, and 1-2 hits/mm for the Ce glass. The test results indicate that scintillating glass fiber-optic plates can be used as high spatial resolution tracking detectors for both fixed target and colliding beam experiments.     

A baseline assessment of cigarette sales to minors in San Diego, California

A community-wide survey of 302 parents of 2-year-old children and 90 private medical practitioners in a large midwestern city revealed low immunization rates (31%) and differences in parent and provider perceptions of barriers to preschool immunizations. Parents most frequently identified barriers of system factors such as cost, lack of insurance coverage, and long office waits. System barriers were reported across differing sources of immunizations (private physician as well as public clinics) and were pervasive across income groups. Providers were more likely to report barriers of parental difficulties with forgetting immunizations or not knowing when the immunizations were due. Even though providers identified parental shortcomings with scheduling as problematic, only one fifth employed tracking and reminder systems. Implications of findings for modifications of the delivery of immunization services and for parent education are discussed.