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Hyperspectral microscope images (HMIs) have previously shown promise as a means for rapid and early detection of foodborne bacteria at the cellular level. System calibration and data normalization are critical for comparing information obtained from HMIs collected with multiple instruments and system parameters. Here, we implement a wavelength and radiometric calibration for spectral data obtained from a hyperspectral microscope, assess the spatial uniformity of HMIs, and show the need to normalize data from single-cell regions of interest (ROIs). A hyperspectral microscope with a tungsten halogen light source, acousto-optical tunable filter, and electron multiplying camera with variable gain and exposure time settings were used. HMIs were collected at additional gain settings of 0%, 1.6%, 3.5%, and 5.1% along with ten exposure time settings between 100 and 1000 ms with both calibration lamps. Wavelength peak shift started to occur at an exposure time of 600 ms for 1.6% gain, at 400 ms for 3.5% gain, and at 200 ms for 5.1% gain. HMIs of E. coli, Salmonella Typhimurium, and Staphylococcus sciuri cells were collected to assess spectral data normalcy and the need for preprocessing spectra from single bacteria cells. Spatial characteristics of cells were assessed by HMIs of a glass slide with a micrometer for determining pixel size from the field of view. HMIs were preprocessed by normalizing cell spectra to the light source and applying multiplicative scatter correction. Data normalcy was assessed on both the raw and preprocessed data sets. Preprocessing the data was found to reduce the cell-to-cell variation associated with a single-cell ROI method, while outliers were detected and verified through HMIs as physically different from other cells. [ABSTRACT FROM AUTHOR]

Optical detection of foodborne bacteria such as Salmonella classifies bacteria by analysing spectral data, and has potential for rapid detection. In this experiment hyperspectral microscopy is explored as a means for classifying five Salmonella serotypes. Initially, the microscope collects 89 spectral measurements between 450 and 800 nm. Here, the objective was to develop correct classification of five serotypes with optimal spectral bands selected through multivariate data analysis (MVDA), thus reducing the data processing and storage requirement necessary for practical application in the food industry. An upright digital microscope is equipped with an acousto-optical tuneable filter, electron multiplying charge-coupled device, and metal halide lighting source. Images for each of the five serotypes were collected, and informative bands were identified through a principal component analysis, for four abbreviated spectral ranges containing 3, 7, 12 and 20 spectral bands. The experiment was repeated with an independent repetition and images were collected at each of the reduced band sets, identified by the first repetition. A support vector machine (SVM) was used to classify serotypes. Results showed that with the first repetition, classification accuracy decreased from 99.5% (89 bands) to 84.5% (3 bands), whereas the second repetition showed classification accuracies of 100%, possibly due to a reduction in spectral noise. The support vector machine regression (SVMR) was applied with cross-validation, and had R2 calibration and validation values >0.922. Although classification accuracies through SVM classification showed that as little as 3 bands were able to classify 100% of the samples, the SVMR shows that the smallest root-mean squared-error values were 0.001 and 0.002 for 20 and 12 bands, respectively, suggesting that the 12 band range collected between 586 and 630 nm is optimal for classifying bacterial serotypes, with only the informative HMI bands selected. [ABSTRACT FROM AUTHOR]

This study determined the effects of extraction buffer pH and postmortem aging on the extraction of salt-soluble and water-soluble proteins from broiler pectoralis muscle. Deboned broiler breast fillets were collected at 4 h postmortem, packaged, and then stored at 4°C until 1, 5, or 8 d postmortem. After the designated aging period, salt-soluble and water-soluble protein extractions were performed using buffers at 7 different pH levels (pH 5.4, 6.4, 6.9, 7.2, 7.5, 8.0, 9.0). Protein concentrations of the extracts were measured and SDS-PAGE analysis was performed. Salt-soluble protein concentration increased (P < 0.0001) as buffer pH increased from pH 5.4 to 6.9 and then remained unchanged from pH 6.9 to 9.0. Water-soluble protein concentration increased (P < 0.0001) as buffer pH increased from pH 5.4 to 7.2 and then remained unchanged from pH 7.2 to 9.0. There was not a significant extraction buffer pH by aging treatment interaction for the total protein concentration of either the salt-soluble or water-soluble protein extracts. The protein concentrations of salt-soluble extracts were similar at both 1 and 8 d postmortem but lower ( P < 0.0001) at 5 d postmortem. The protein concentrations of water-soluble extracts were similar at both 1 and 5 d postmortem, but higher (P < 0.0001) at 8 d. Both extraction buffer pH and postmortem aging influenced the SDS-PAGE protein profiles of salt-soluble and water-soluble protein extracts from breast muscles. Data demonstrate that postmortem aging and extraction buffer pH influence both the total amount and the composition of the myofibrillar and sarcoplasmic proteins that can be extracted from broiler breast fillets. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this systematic review was to investigate professional learning models (length, mode, content) offered as part of objectively measured physical childcare‐based interventions. A systematic review of eight electronic databases was conducted to June 2017. Only English, peer‐reviewed studies that evaluated childcare‐based physical activity interventions, incorporated professional learning and reported objectively measured physical activity were included. Study designs included randomized controlled trails, cluster randomized trials, experimental or pilot studies. The search identified 11 studies. Ten studies objectively measured physical activity using accelerometers; five studies used both accelerometer and direct observation tools and one study measured physical activity using direct observation only. Seven of these studies reported statistically significant intervention effects. Only six studies described all components of professional learning, but only two studies reported specific professional learning outcomes and physical activity outcomes. No patterns were identified between the length, mode and content of professional learning and children's physical activity outcomes in childcare settings. Educators play a critical role in modifying children's levels of physical activity in childcare settings. The findings of this review suggest that professional learning offered as part of a physical activity intervention that potentially impacts on children's physical activity outcomes remains under‐reported. [ABSTRACT FROM AUTHOR]