Use of gelatin gels as a reference material for performance evaluation of meat shear force measurements

Abstract: Establishing standards for meat tenderness based on Warner–Bratzler shear force (WBSF) is complicated by the lack of methods for certifying WBSF testing among texture systems or laboratories. The objective of this study was to determine the suitability of using gelatin gels as reference materials for performance testing of texture measurement systems. Three replications of 5 gels (15%, 20%, 25%, 30%, and 35% gelatin) were prepared, vacuum packaged, and stored at 4 °C until use. Three randomly selected strips from each gel were subjected to WBSF testing on 4 instruments (A, B, C, or D) on days 1 and 8. Additional strips from each gel were subjected to WBSF testing on instruments A and C on day 29. Regression line estimates for each set of gels were analyzed. Gel WBSF values ranged from 10 to 177 N. The WBSF by gel concentration response was highly linear (P < 0.0001) for all replications, instruments, and days of analysis. R²‐values across all sets of gels ranged from 0.9562 to 0.9998. On days 1 and 8, instruments A and D exhibited higher slope (P < 0.0001) and lower intercept (P < 0.0001) estimates than instruments B and C. Regression line parameters (slope, intercept, and R²‐values) were not influenced (P > 0.05) by length of gel storage (1, 8, and 29 d). Data from this study suggest that gelatin gels can be used for evaluating WBSF values from various instruments and for validating the performance of meat shear force testing. Practical Application: Validating the performance of meat shear force testing is vital to establishing meat tenderness standards. The gelatin gel standards developed in this study exhibited a highly linear, repeatable relationship with shear force and were found to be stable for at least a month. These gel standards would provide a tool for the meat industry to harmonize shear force measurements across laboratories and various texture measuring instruments.     

Synthesis,structural analysis and microwave dielectric properties of LnTiSb<Subscript>x</Subscript>Nb<Subscript>1−x</Subscript>O<Subscript>6</Subscript> (Ln = Ce,Pr) ceramics

LnTiSb_xNb_1−xO₆ (Ln = Ce, Pr) ceramics were prepared by the conventional solid state ceramic route for x = 0, 0.05, 0.1, 0.15, 0.2 and 0.25. The structure of the materials was analyzed using X-ray diffraction techniques. The cell parameters and the theoretical densities of the samples were calculated using least square methods. The samples are sintered to more than 90% of the theoretical density at 1,325–1,350 °C. The microwave dielectric properties were measured using the cavity resonator method. The surface morphology of the sintered sample was analyzed using Scanning Electron Microscopy. All the materials have good microwave dielectric properties and are suitable for dielectric resonator applications.     

Solid-state photoelectrochemical device based on poly(3-hexylthiophene) and an ion conducting polymer electrolyte, amorphous poly(ethylene oxide) complexed with I3/I redox couple

The photoelectrochemical properties of a solid-state photoelectrochemical cell (PEC) based on poly(3-hexylthiophene), P3HT, and an ion-conducting polymer electrolyte, amorphous poly(ethylene oxide), POMOE, complexed with I₃⁻/I⁻ redox couple has been constructed and studied. The current–voltage characteristics in the dark and under white light illumination, transient photocurrent and photovoltage studies, photocurrent action spectra for front and back side illuminations and an open-circuit voltage and short-circuit current dependence on light intensity have been studied. An open-circuit voltage of 130 mV and a short-circuit current of 0.47 μA cm⁻² were obtained at light intensity of 100 mW/cm². IPCE% of 0.024% for front side illumination (ITO/PEDOT) and IPCE% of 0.003% for backside illumination (ITO/P3HT) were obtained.     

Surgery and the randomised controlled trial: past, present and future

Randomised controlled trials (RCTs), with their prospective definition of methods and outcome measures, double-blind assessment of outcomes and unbiased selection of subjects and controls, provide the best possible evidence for deciding the value of a medical or surgical intervention. Few surgical studies are designed as RCTs, and those that are should be of a higher quality. The lack of good surgical RCTs may be a result of surgeons lacking the necessary training, expertise and desire to perform RCTs, inadequate funding from granting agencies, difficulties in securing patient consent or a lack of sufficient patient numbers. If an RCT is not feasible for a particular study, then alternative research designs, such as prospective matched-pair trials, may need to be better developed and used. If RCTs can be performed, other strategies to increase the number and quality of RCTs may be needed: Education of surgeons in clinical research methods Improved funding of surgical RCTs Compulsory evaluation of new techniques and technology before their general adoption is permitted.     

Haplotype and phenotype analysis of six recurrent BRCA1 mutations in 61 families: results of an international study

Central to the Mu transpositional recombination are the two chemical steps; donor DNA cleavage and strand transfer. These reactions occur within the Mu transpososome that contains two Mu DNA end segments bound to a tetramer of MuA, the transposase. To investigate which MuA monomer catalyzes which chemical reaction, we made transpososomes containing wild-type and active site mutant MuA. By pre-loading the MuA variants onto Mu end DNA fragments of different length prior to transpososome assembly, we could track the catalysis by MuA bound to each Mu end segment. The donor DNA end that underwent the chemical reaction was identified. Both the donor DNA cleavage and strand transfer were catalyzed in trans by the MuA monomers bound to the partner Mu end. This arrangement explains why the transpososome assembly is a prerequisite for the chemical steps.     

The cultural context of interventions for family members with a seriously mentally ill relative

This chapter provides an overview of interventions for relatives of severely mentally ill individuals. The author discusses the design and use of these interventions in the context of the cultural characteristics of families and providers, as well as the culture of the interventions themselves.     

The effect of a new tear substitute containing glycerol and hyaluronate on keratoconjunctivitis sicca

The present study of asthmatic children examined relationships among the frequencies of prior respiratory infections (i.e., those prior to the development of asthma) and recent (past year) respiratory infections, asthma severity, and the impacts of 12 common asthma triggers: air pollution, allergy problems, anger, cigarette smoke, excitement, high humidity, high or low environmental temperature, laughter, nighttime hours, physical activity, respiratory infection, and stress or worry. Data on these variables were obtained through a survey in which 325 families completed questionnaires; 121 families had asthmatic children who were 2-20 years of age. Pearson correlational analyses revealed many significant positive correlations: The frequencies of prior and recent infections were correlated. The frequency of prior infections was correlated with the impacts of all asthma triggers except allergy problems, but the frequency of recent infections was correlated only with the impacts of air pollution, cigarette smoke, respiratory infection, and nighttime hours as triggers of asthma attacks. Asthma severity was correlated with the frequencies of prior and recent respiratory infections and with the impact of respiratory infection as an asthma trigger.     

Visibility of wavelet quantization noise

The discrete wavelet transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression, measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that we call DWT uniform quantization noise; it is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r2^-λ, where r is the display visual resolution in pixels/degree, and λ is the wavelet level. Thresholds increase rapidly with wavelet spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from lowpass to horizontal/vertical to diagonal. We construct a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a “perceptually lossless” quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes     

Consequences of electroencephalographic-suppressive doses of propofol in conjunction with deep hypothermic circulatory arrest

BACKGROUND: Some patients who undergo cerebral aneurysm surgery require cardiopulmonary bypass and deep hypothermic circulatory arrest. During bypass, these patients often are given large doses of a supplemental anesthetic agent in the hope that additional cerebral protection will be provided. Pharmacologic brain protection, however, has been associated with undesirable side effects. These side effects were evaluated in patients who received large doses of propofol. METHODS: Thirteen neurosurgical patients underwent cardiopulmonary bypass and deep hypothermic circulatory arrest to facilitate clip application to a giant or otherwise high-risk cerebral aneurysm. Electroencephalographic burst suppression was established before bypass with an infusion of propofol, and the infusion was continued until the end of surgery. Hemodynamic and echocardiographic measurements were made before and during the prebypass propofol infusion and again after bypass. Emergence time also was determined. RESULTS: Prebypass propofol at 243 +/- 57 micrograms.kg-1.min-1 decreased vascular resistance from 34 +/- 8 to 27 +/- 8 units without changing heart rate, arterial or filling pressures, cardiac index, stroke volume, or ejection fraction. Propofol blood concentration was 8 +/- 2 micrograms/ml. Myocardial wall motion appeared hyperdynamic at the end of cardiopulmonary bypass, and all patients were weaned therefrom without inotropic support. After bypass, vascular resistance decreased further, and cardiovascular performance was improved compared to baseline values. Nine of the 13 patients emerged from anesthesia and were able to follow commands at 3.1 +/- 1.4 h. Three others had strokes and a fourth had cerebral swelling. CONCLUSIONS: Propofol infused at a rate sufficient to suppress the electroencephalogram does not depress the heart or excessively prolong emergence from anesthesia after cardiopulmonary bypass and deep hypothermic circulatory arrest.     

Heterotrimeric G proteins physically associated with the lipopolysaccharide receptor CD14 modulate both in vivo and in vitro responses to lipopolysaccharide

Septic shock induced by lipopolysaccharide (LPS) triggering of cytokine production from monocytes/macrophages is a major cause of morbidity and mortality. The major monocyte/macrophage LPS receptor is the glycosylphosphatidylinositol (GPI)-anchored glycoprotein CD14. Here we demonstrate that CD14 coimmunoprecipitates with Gi/Go heterotrimeric G proteins. Furthermore, we demonstrate that heterotrimeric G proteins specifically regulate CD14-mediated, LPS-induced mitogen-activated protein kinase (MAPK) activation and cytokine production in normal human monocytes and cultured cells. We report here that a G protein binding peptide protects rats from LPS-induced mortality, suggesting a functional linkage between a GPI-anchored receptor and the intracellular signaling molecules with which it is physically associated.