Relationship between cyanogenic compounds in kernels, leaves, and roots of sweet and bitter kernelled almonds.

The relationship between the levels of cyanogenic compounds (amygdalin and prunasin) in kernels, leaves, and roots of 5 sweet-, 5 slightly bitter-, and 5 bitter-kernelled almond trees was determined. Variability was observed among the genotypes for these compounds. Prunasin was found only in the vegetative part (roots and leaves) for all genotypes tested. Amygdalin was detected only in the kernels, mainly in bitter genotypes. In general, bitter-kernelled genotypes had higher levels of prunasin in their roots than nonbitter ones, but the correlation between cyanogenic compounds in the different parts of plants was not high. While prunasin seems to be present in most almond roots (with a variable concentration) only bitter-kernelled genotypes are able to transform it into amygdalin in the kernel. Breeding for prunasin-based resistance to the buprestid beetle Capnodis tenebrionis L. is discussed.

Determination of the total iron content of used lubricating oils by atomic-absorption with use of emulsions.

A new method is proposed for the determination of the total iron content of used lubricating oils. It is based on treatment of the samples with a mixture of hydrofluoric and nitric acids (without destruction of the organic matter) and emulsification, followed by atomic-absorption measurement. This allows the use of aqueous standards and provides a simple, rapid, inexpensive and accurate method, that is not affected by the particle size of the solids in the oil.

A cooperative approach for the diagnosis of the melanoma.

In this work we present a decision support system for the melanoma diagnosis using individual methods and the collaboration between these methods. The system designed uses a photograph of the lesion and it makes a preprocessing task to extract the region of interest. Then, several characteristics of the image are analyzed, studying with different methods the degree of malignity; the methods used are based in Bayesian rules and in neural networks. Finally, each individual decision from each method contributes in some way to the final decision. The classification rate obtained with the cooperative approach is above 92%.

Persistent auditory hallucinations.

BACKGROUND: There is still a significant proportion of psychotic patients who suffer from persistent auditory hallucinations (PAH) in spite of treatment. The objective of our study was to analyze those clinical dimensions that characterize persistent hallucinators in comparison with episodic hallucinators. SAMPLING AND METHODS: Ninety-one outpatients with AH were assessed through semistructured interviews. The interviews included the Psychotic Symptom Rating Scales for AH and the Krawiecka scale. They elicited descriptions about the persistence of AH, existence of pleasurable hallucinations and other types of hallucinations. RESULTS: Forty-five patients fulfilled criteria for reported PAH. Persistent hallucinators showed greater scores in frequency and duration of hallucinations, Krawiecka total score and incoherence of speech. Moreover, pleasurable experiences were more frequent in this group of patients. Logistic regression analysis rendered a model with the following variables: duration of voices, degree of control and pleasurable hallucinations. CONCLUSION: Specific dimensions of AH can predict the possibility of treatment resistance.

Purge-and-trap gas chromatographic determination of styrene in urine and blood. Application to exposed workers.

A simple purge-and-trap gas chromatographic method with flame ionization detection was developed for the determination of styrene in urine and blood. Styrene present in a 5 ml sample at room temperature was swept by helium at 40 ml/min for 11 min, trapped on a Tenax trap, desorbed by heating, cryofocused, and injected by flash heating into a DB-5 capillary GC column. The oven temperature program was from 80 degrees C, held for 8 min, to 120 degrees C at 5 degrees C/min, and then held for 2 min. The detector temperature was 250 degrees C. The calibration curves were linear in the range of 2.5-15 ppb styrene in urine and 25-150 ppb in blood. The detection limits calculated were 0.4 microg/l in urine and 0.6 microg/l in blood. The coefficients of variations within the day and day-to-day were 3 and 3.1%, respectively, for 2.5 ppb of styrene in urine, and 1 and 1.6% for 25 ppb of styrene in blood. The results obtained from samples taken from workers exposed to styrene were reported.