38 research outputs found

    Recurrent neural identification and control of a continuous bioprocess via first and second order learning

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    This paper applies a new Kalman Filter Recurrent Neural Network (KFRNN) topology and a recursive Levenberg-Mar quardt (L-M) learning algorithm capable to estimate para meters and states of highly nonlinear unknown plant in noisy environment. The proposed KFRNN identifier, learned by the Backpropagation and L-M learning algorithm, was incorporated in a direct and indirect adaptive neural con trol schemes. The proposed control schemes were applied for real-time recurrent neural identification and control of a continuous stirred tank bioreactor model, where fast convergence, noise filtering and low mean squared error of reference tracking were achieved

    An albino form of Auricularia fuscosuccinea from Lacandonia tropical forest, Chiapas, Mexico

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    An albino form of Auricularia fuscosuccinea is described from Chiapas tropical forest in Mexico. The taxonomy of Auricularia species is briefly reviewed

    Volatile fraction of ewe's milk semi-hard cheese manufactured with and without the addition of a cysteine proteinase

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    A dynamic headspace technique (purge and trap) coupled to gas chromatography-mass spectrometry was used for the study of the volatile fraction of pasteurized ewe's milk cheese. The effect of the addition of the cysteine proteinase of Micrococcus sp. INIA 528 to milk on the formation of volatile aroma compounds in cheese was also evaluated. Forty-five compounds, in total, were identified, including hydrocarbons, alcohols, ketones, aldehydes, esters, terpenes and sulfur compounds. The abundance of most volatile compounds increased significantly (P < 0.05) with ripening time, except those of ethanol and 2, 3-butanedione which decreased. Acetaldehyde and some minor components did not vary remarkably during ripening. Acetaldehyde, 2-methyl-1-butanal, 3-methyl-1-butanal, 2-propanol, 2-pentanone and 3-methyl-3-buten-1-ol were the only compounds affected by the addition of cysteine proteinase. The more extensive proteolysis in cheese with cysteine proteinase might have enhanced the formation of volatile compounds derived from amino acids, such as acetaldehyde, 2-methyl-1-butanal and 3-methyl-1-butanal, formed from threonine, isoleucine and leucine breakdown, respectively

    Case report: Penile necrosis associated to paraphimosis with calciphylaxis due to terminal chronic kidney disease [version 1; peer review: 2 approved]

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    Penile necrosis is a rare condition that may present in patients with diabetes mellitus or chronic kidney disease (CKD). The recommended treatment is controversial. We report a case of penile necrosis in a diabetic patient caused by episode of paraphimosis associated with uremic arteriopathy treated with partial amputation. Clinical Case: A 53-year-old male with a background of arterial hypertension, diabetes mellitus and CKD in hemodialysis. The patient presented with paraphimosis and glans necrosis. An emergency circumcision was carried out. A doppler ultrasound found fluid collection in the left corpus cavernosum, parietal vascular calcifications and vascular insufficiency in the corpus cavernosum that suggested necrosis. A partial amputation of the penis was carried out. After three years of follow-up, the outcome has remained favorable

    Proteolysis and formation of volatile compounds in cheese manufactured with a bacteriocin-producing adjunct culture

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    Hispánico cheese, a semi-hard Spanish variety, was manufactured from a mixture of pasteurized cows' and ewes' milks (41) using a commercial mesophilic LD-type starter comprising Lactococcus lactis subsp. cremoris, Lc. lactis subsp. lactis, Lc. lactis subsp. lactis var diacetylactis and Leuconostoc mesenteroides subsp. cremoris. Varying amounts (0-1·0 g/kg) of an Enterococcus faecalis INIA 4 culture in milk were added as a bacteriocin-producing adjunct. Differences in pH between cheeses manufactured with and without the bacteriocin producer did not exceed 0·11 pH units. Starter lactococci lost viability more rapidly in cheeses made with the bacteriocin producer, which reached counts of up to 6 × 107 cfu/g during ripening. Aminopeptidase activity in 1-d-old cheese made from milk inoculated with 1·0 g bacteriocin-producing culture/kg was twice that in control cheese. Degrees of overall proteolysis and levels of total free amino acids in 45-d-old cheese made with 1·0 g bacteriocin-producing culture/kg were 1·80-fold and 2·17-fold those in control cheese of the same age. Inoculating milk with 1·0 g/kg bacteriocin-producing culture reduced the level of hydrophobic peptides in the resultant cheese, increased the concentrations of 3-methyl-1-butanal, diacetyl and acetoin, and resulted in the highest scores for flavour quality and flavour intensity throughout ripening
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