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Biomedical subjects

P Dardenne

Publications and source records attributed to P Dardenne.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of pretreatment strategies for near-infrared spectroscopy calibration development of unground and ground compound feedingstuffs.

Chemometric procedures are usually applied to near-infrared (NIR) spectra in order to obtain prediction models. These procedures include the application of different combinations of spectral mathematical pretreatments for the improvement of calibrations and the selection of the best model on the basis of validation results. In this work, we used an automatic routine to obtain calibrations for unground and ground compound feedingstuffs (N=354 samples), including 49 combinations of pretreatments (first and second derivatives, an auto scaling procedure, detrending and two versions of multiplicative scatter correction). Calibrations for crude fiber and crude protein were developed without elimination of outliers and with 2 or 9 maximum passes of elimination of outliers. Validation statistics were highly influenced by the pretreatments used, as a combined result of their ability to improve the detection of outliers and the model adjustment. The standard error of prediction (SEP) values ranged from 0.61 to 1.27 for crude protein (CP) and from 0.74 to 1.33 for crude fiber (CF). In spite of the fact that validation statistics did not show a clear distribution pattern, some combinations of pretreatments provided consistently better results.

Algorithms↗
PubMed2006

Estimating fatty acid content in cow milk using mid-infrared spectrometry.

Interest in the fatty acid composition of dairy products is increasing; however, the measurement of fatty acids requires using gas-liquid chromatography. Although this method is suitable, it involves a time-consuming procedure, expensive reagents, and qualified staff. By comparison, the mid-infrared (MIR) spectrometry method could be a good alternative for assessing the fatty acid profile of dairy products. The objective of this study was to explore the calibration of MIR spectrometry for estimating fatty acid concentrations in milk and milk fat. Estimated concentrations in milk fat were less reliable than those for the same fatty acids in milk. Results also showed that when the fatty acid concentrations in milk increased, the efficiency of the infrared analysis method in predicting these values simultaneously increased. Selected prediction equations must have a high cross-validation coefficient of determination, a high ratio of standard error of cross-validation to standard deviation, and good repeatability of chromatographic data. Results from this study showed that the calibration equations predicting 12:0, 14:0, 16:0, 16:1cis-9, 18:1, and saturated and monounsaturated fatty acids in milk could be used. Thus, with its potential for use in regular milk recording, this infrared analysis method offers the possibility of assessing and improving the quality of milk produced. Indeed, it enables the fatty acid composition in milk to be estimated for each cow and the estimates to be used as indicator traits to determine the genetic values of underlying fatty acid concentrations. The knowledge of these genetic values would open up opportunities for animal selection aimed at improving the nutritional quality of cow milk.

Animals↗
PubMed2006

Variation in fatty acid contents of milk and milk fat within and across breeds.

The aim of this research was to study the potential for selection of cows with a higher nutritional quality of milk fat by studying the differences in fatty acid profiles within and across the following breeds: Dual Purpose Belgian Blue, Holstein-Friesian, Jersey, Montbeliarde, and non-Holstein Meuse-Rhine-Yssel type Red and White. Six hundred milk samples from 275 animals were taken from 7 herds. Several types of fatty acids in milk and milk fat were quantified using mid-infrared spectrometry and previously obtained calibration equations. Statistical analyses were made using a mixed linear model with a random animal effect. The variance components were estimated by using REML. Results showed breed differences for the fatty acid profile. The repeatability estimate obtained in the present study may suggest the existence of moderate additive genetic variance for the fatty acid profile within each breed. Results also indicated variation for each analyzed milk component in the whole cow population studied. Genetic improvement of the nutritional quality of milk fat based on fatty acid profiles might be possible, and further research and development are warranted.

Animals↗
PubMed2005

Classification of modified starches by fourier transform infrared spectroscopy using support vector machines.

The aim of this study was to compare the performance of different supervised discrimination methods based on IR data for the classification of starches according to the type of chemical modification undergone. The goal of the supervised classification methods is to develop classification rules. Representative samples of each group (known beforehand) were available, from which the relevant characteristics (chemical modification) were known. On the basis of a training data set, classification rules are determined, which can then be applied to classify new (unknown) samples.

Spectroscopy, Fourier Transform Infrared↗
PubMed2001

Interpretation of Fourier transform Raman spectra of the unsaponifiable matter in a selection of edible oils.

The unsaponifiable matter of edible oils is a source of information for their characterization and authentication. FT-Raman spectroscopy has been applied with success to the determination of the spectra of the unsaponifiable matter of varietal olive oils as well as other refined and crude edible oils. The spectra of the major unsaponifiable series of compounds (squalene, sterolic, and terpenic alcoholic fractions), together with beta-carotene and lutein, have been used to explain the most prominent bands found in the spectra of the unsaponifiable matter of 15 edible oil samples. The order of the scattering intensities of the varietal olive oils agrees with the results obtained by chromatography. An unsupervised multivariate statistical analysis of selected bands points out differences between olive oils and the other seed oils and also among varietal virgin olive oils.

Dietary Fats, Unsaturated↗
PubMed1993

[Incest by the mother: clinical and therapeutic aspects].

Whereas clinical and preventive aspects of father-daughter incest are now better-known, mother-child incest remains mysterious. Reporting four recent cases, the authors attempt to describe its main clinical features, particularly those which could allow earlier diagnosis. An original "constructive" therapeutic approach of the most severely mentally disturbed children among these victims is then developed: the emphasis is put on how medical, social and legal procedures might be coordinated.

Child↗
PubMed1979

[Outcome of myocardial infarctions complicated by heart conduction disorders in the acute phase].

Of 945 patients hospitalised for myocardial infarction between January 1st 1972 and December 31st 1975, 40 with anterior myocardial infarction (Group I-A) and 53 with posterior myocardial infarction (Group II-A) were complicated by atrioventricular and/or intraventricular arrhythmias. The average follow up period is now of 48 months (range 24 to 78 months). Their outcome was compared to two control groups of 50 anterior myocardial infarctions (Group I-B) and 50 posterior myocardial infarctions (Group II-B) uncomplicated by arrhythmias in the acute phase. The immediate (10%) and secondary (30%) mortality was identical in the two groups II-A and II-B with posterior wall necrosis. The immediate (32%) and secondary (40%) mortality in Group I-A was much higher than in Group I-B (22% and 28% respectively). Sudden death was the most frequent form of demise in all groups (I-A, II-A, II-B) except Group I-B in which heart failure predominated. Death occured earlier in Group I-A than in the control Group II-B. These results pose the problem of the indication of prophylactic permanent pacing to decrease the incidence of sudden death.

Acute Disease↗
PubMed1979

[Continuous ambulatory electrocardiographic recordings using the Holter system in the late phase of hospitalization for recent myocardial infarct. Value and limitations studied in a series of 100 patients].

Repeated continuous ambulatory electrocardiography by Holter monitoring was performed after early mobilisation post-myocardial infarction in 100 patients, without ventricular extrasystoles on classical ECG. Frequent ventricular arrhythmias were recorded in 58 p. 100 cases, unrelated to the localisation of the infarct. The observation of ventricular arrhythmias in the Coronary Care Unit (CCU) was not related to the occurrence of VEs during Holter monitoring. On the other hand, VEs were less frequent (38 p. 100 compared to 68 p. 100) in patients taking amiodarone or betablockers on transfer from the CCU. The reduced activity of patients during Holter monitoring minimises the frequency of arrhythmias, and 10 p. 100 patients were observed to have VEs only after exercise tolerance testing. These VEs seem to be a bad prognostic factor; the 9 patients who died in this series all presented VEs on ambulatory monitoring (7) or during exercise tolerance testing (2). However the number of patients with triple vessel disease was greater in the group with VEs on ambulatory monitoring (57 p. 100 compared with 13 p. 100). It is difficult to assess the precise role of the VEs amongst the other risk factors of sudden death. This is not a randomised study, but it would appear that long=term amiodarone or betablockers therapy may influence the medium-term prognosis.

Adrenergic beta-Antagonists↗
PubMed1979

[Unstable angina with threatening coronary lesions turned down for surgery. Outcome and prognostic factors].

The aim of this study based on a series of 200 patients, was to define the outcome and the prognostic factors of patients presenting with unstable angina, according to Bertolazi's criteria [3] and at least one stenosis greater than 80% on a proximal segment of a main coronary trunc, and to determine which factors should eventually be taken into consideration in the discussion of surgical indications. 70 out of 200 patients (35%) were turned down for direct revascularisation surgery because of an ejection fraction less than 0,35 and/or a poor arterial run off. Coronary arteriography showed 30% patients with a menacing stenosis (greater than 80%) on all three vessels, 36% on two vessels and 22% on a single vessel. The distribution and the extent of the lesions was about the same as in the operated patients. 20% patients had an ejection fraction less than 0,35, 24% between 0,34 and 0,50, and 56% greater than 0,50. At patient, the follow up period ranges from 22 to 66 months (average 32 months). In this group, the hospital mortality was 2,9%, the secondary cardiac deaths 16% and the global mortality 19% compared to 12,6% for the operated patients in the same period. The incidence of secondary non-fatal infarction was low (9%). 52% of survivors have persistent angina, 39% severe (Class II or III). Two prognostic factors were detected from this study: the type of angina: the intermediary syndrome had a bad prognosis, 38,5% mortality compared to 13% for aggravated chronic angina; and the ventriculography: patients with ejection fractions less than 0,35 had 64% mortality compared to 7,3% for those with ejection fractions greater than 0,40. The number of menacing lesions, the extent of the lesions of the artery involved did not affect the prognosis when severe abnormalities of left ventricular function were absent.

Adrenergic beta-Antagonists↗