ABSTRACT
This work reports a candidate screening protocol to distinguish beef from horse meat based upon comparison of triglyceride signatures obtained by 60 MHz (1)H NMR spectroscopy. Using a simple chloroform-based extraction, we obtained classic low-field triglyceride spectra from typically a 10 min acquisition time. Peak integration was sufficient to differentiate samples of fresh beef (76 extractions) and horse (62 extractions) using Naïve Bayes classification. Principal component analysis gave a two-dimensional "authentic" beef region (p=0.001) against which further spectra could be compared. This model was challenged using a subset of 23 freeze-thawed training samples. The outcomes indicated that storing samples by freezing does not adversely affect the analysis. Of a further collection of extractions from previously unseen samples, 90/91 beef spectra were classified as authentic, and 16/16 horse spectra as non-authentic. We conclude that 60 MHz (1)H NMR represents a feasible high-throughput approach for screening raw meat.
Subject(s)
Cattle , Horses , Meat/analysis , Nuclear Magnetic Resonance, Biomolecular/methods , Animals , Food Analysis/methods , HumansABSTRACT
There are many techniques available for the analysis of MRI data. Often these methods are presented as completed algorithms, which specify what processing must be performed, but they are rarely presented in a way which makes clear the assumptions that must hold in order that these algorithms will provide valid results. The aim of this review article is to relate the common forms of algorithms and to explain the assumptions behind them. This is done in the context of the use of quantitative statistical methods, which we understand to be the only self-consistent method for any data analysis. We hope that this will go some way towards helping with the choice of which algorithm to use for particular analysis tasks.
Subject(s)
Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging , Algorithms , Brain/anatomy & histology , Data Interpretation, Statistical , HumansABSTRACT
We describe continuous positive airway pressure (CPAP) by mask to reduce hypercarbia in two patients who had pulmonary edema due to congestive heart failure. In such patients, beside reducing venous return and filling pressures, CPAP improves compliance and decreases the work of breathing, thereby improving effective ventilation. Hence, CPAP may be useful to combat not only hypoxemia but also hypercarbia that is associated with pulmonary edema.