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E Pardo

Publications and source records attributed to E Pardo.

15 recordsLinked to original sources
PubMed2006

Noise reduction in ultrasonic NDT using undecimated wavelet transforms.

Translation-invariant wavelet processing is applied to grain noise reduction in ultrasonic non-destructive testing of materials. In particular, the undecimated wavelet transform (UWT), which is essentially a discrete wavelet transform (DWT) that avoids decimation, is used. Two different UWT processors have been specifically developed for that purpose, based on two UWT implementation schemes: the "à trous" algorithm and the cycle-spinning scheme. The performance of these two UWT processors is compared with that of a classical DWT processor, by using synthetic grain noise registers and experimental pulse-echo NDT traces. The synthetic ultrasonic traces have been generated by an own-developed frequency-domain model that includes frequency dependence in both material attenuation and scattering. The experimental ultrasonic traces have been obtained by inspecting a piece of carbon-fiber reinforced plastic composite in which we have mechanized artificial flaws. Decomposition level-dependent thresholds, which are suitable for correlated noise, are specifically determined in all cases. Soft thresholding, Daubechies db6 mother wavelet and the three well-known threshold selection rules, Universal, Minimax and SURE, are applied to the different decomposition levels. The performance of the different de-noising procedures for single echo detection has been comparatively evaluated in terms of signal-to-noise ratio enhancement.

Journal Article↗
PubMed2006

Ecophysiology of ochratoxigenic Aspergillus ochraceus and Penicillium verrucosum isolates. Predictive models for fungal spoilage prevention - a review.

Ochratoxin A (OTA) is a secondary metabolite produced by several species of Aspergillus and Penicillium; among them Aspergillus ochraceus and Penicillium verrucosum are two ochratoxigenic species capable of growing in different climates and thus contamination of food crops with OTA can occur worldwide. OTA can be found in a wide range of foods such as cereals, coffee, cocoa, spices, beer, wine, dried vine fruit, grapes and meat products. OTA is toxic to animals, it presents neurotoxic, immunotoxic and nephrotoxic effects. It has been implicated in a human kidney disorder known as Balkan Endemic Nephropathy. This review focuses on the ecophysiology of ochratoxin-producing Aspergillus ochraceus and Penicillium verrucosum, the effect of environmental factors on their germination, mycelial growth, and OTA production. Knowledge of environmental conditions required for sucessive stages of fungal development represent the first step towards preventing mycotoxin formation. Predictive models for different stages of fungal development are presented, which allow prediction of the time before spoilage as a function of the abiotic factors. Finally, the implications of these studies in management of barley, coffee and grapes are described. This can help to identify the critical control points in their production, storage and distribution processes.

Aspergillus ochraceus↗
PubMed2005

Effects of water activity and temperature on germination and growth profiles of ochratoxigenic Penicillium verrucosum isolates on barley meal extract agar.

The aim of this work was to study the combined effects of water activity (aw, 0.75-0.99), temperature (10-30 degrees C) and isolate on spore germination and mycelial growth of ochratoxigenic Penicillium verrucosum isolates on barley meal extract agar (BMEA). Lag phases prior to germination (h), germination rates (h(-1)) and growth rates (mm day(-1)) were obtained at each set of conditions and for all the isolates. Analysis of variance showed a significant influence of the abiotic factors assayed on fungal development. Minimum aw levels found for germination and mycelial growth were 0.80 and 0.85, respectively, while maximum germination and growth rates were obtained at 0.95-0.99 aw level. Although maximum germination was obtained at 20 degrees C, significant differences were not found between growth rates at 20 and 30 degrees C. Data were modelled by MLR regressions and response surface models were obtained. Spore germination and mycelial growth of ochratoxigenic P. verrucosum isolates are significantly affected by water activity and temperature. Moreover, different isolates may have slightly different response to environmental factors. Predictive models obtained may allow a rough prediction of germination/growth as a function of the storage temperature and moisture content of barley grains.

Agar↗
PubMed2005

Non-specificity of nutritional substrate for ochratoxin A production by isolates of Aspergillus ochraceus.

Aspergillus ochraceus is an important contaminant of diverse substrates, such as cereals, coffee, grapes and derivates. This fungus produce a nephrotoxic metabolite, ochratoxin A (OTA), whose presence on food and feeds may be an important risk for animal and human health. The aim of this work was to evaluate the significance of the origin of A. ochraceus isolates on their OTA production patterns on different substrates (yeast extract sucrose (YES) broth, irradiated barley grains, irradiated green coffee beans and sterilized grapes) and under different environmental conditions. Results did not show a significant influence of the isolation source on OTA-production profiles by A. ochraceus isolates on several substrates, since the isolates which produced the highest OTA amounts in vitro (YES medium) were also the isolates with the highest OTA yields on the other substrates. Abiotic factors assayed (water activity, temperature and substrate) affected significantly OTA productions by A. ochraceus. Maximum OTA amounts were detected at 25 degrees C and 0.98 a(w) on all substrates tested. The highest OTA accumulations found on the different substrates were: green coffee beans (> 2 mg g(-1)), barley grains (approximately 1 mg g(-1)), YES medium (13.9 microg ml(-1)) and grape (approximately 3 ng g(-1)).

Aspergillus ochraceus↗
PubMed2005

Modelling of effects of water activity and temperature on germination and growth of ochratoxigenic isolates of Aspergillus ochraceus on a green coffee-based medium.

Influence of water activity (0.75-0.99 a(w)) and temperature (10, 20 and 30 degrees C) on germination and mycelial growth on green coffee extract agar medium of three ochratoxigenic isolates of Aspergillus ochraceus was studied. Optimal conditions for germination and growth were observed at 0.95-0.99 a(w) and 20-30 degrees C for the three isolates. Minimum a(w) level for germination was 0.80, and 0.85 for mycelial growth. At marginal a(w) and temperature levels assayed, the lag phases prior to germination increased and the growth rates showed a significant decrease in comparison with the optimal conditions. Data were modelled by a multiple linear regression (MLR) and response surface models were obtained. Germination and growth of A. ochraceus in green coffee beans could be prevented or at least inhibited to some extent by minimising the time that coffee beans are exposed to temperature and humidity conditions near to the optimum during processing and storage. This could be an empirical approach to predict the effects of water activity and temperature conditions on the development of ochratoxigenic isolates of A. ochraceus during handling and storage of green coffee.

Aspergillus ochraceus↗
PubMed2005

Effect of water activity and temperature on mycelial growth and ochratoxin A production by isolates of Aspergillus ochraceus on irradiated green coffee beans.

Aspergillus ochraceus as a fungal contaminant and ochratoxin A (OTA) producer plays an important role in coffee quality. Temperature and water activity (a(w)) significantly influence mycelial growth and OTA production by isolates of A. ochraceus on green coffee beans. Maximum mycelial growth was found at 30 degrees C and 0.95 to 0.99 a(w). A marked decrease in growth rate was observed when temperature and a(w) were reduced. At 0.80 a(w), mycelial growth occurred only at 30 and 20 degrees C for one isolate. Maximum OTA production was found at 20 degrees C and 0.99 a(w). At 10 degrees C, OTA was not produced, regardless of a(w). Similarly, no OTA was detected at 0.80 a(w). OTA production ranged from the limit of detection (40 ng g(-1) of green coffee) to 17,000 ng g(-1) of green coffee. Significant intraspecific differences in mycelial growth and OTA production were found. Primary data for lag phases prior to mycelial growth under the influence of temperature and a(w) were modelled by multiple linear regression, and the response surface plots were obtained.

Aspergillus ochraceus↗
PubMed2004

Prediction of fungal growth and ochratoxin A production by Aspergillus ochraceus on irradiated barley grain as influenced by temperature and water activity.

Ochratoxin A (OTA) is a secondary metabolite of Aspergillus and Penicillium species, including Aspergillus ochraceus, a species that can be found in stored cereal grains such as barley. The objective of this study was to determine the effects of water activity (a(w), 0.80-0.99), temperature (10, 20, 30 degrees C), and A. ochraceus isolate differences on radial growth and OTA production in irradiated barley grains. The three isolates showed optimal conditions for growth and ochratoxin A production at 0.99 a(w) and 30 degrees C, with a marked decrease of growth rates and OTA production at the lowest levels of a(w) and temperature assayed. The minimum a(w) level for growth, observed in this study, was 0.85 and 0.90 a(w) for OTA production. Significant differences among the isolates were found. Lag phases prior to fungal growth and OTA production values were modelled by multiple linear regression and response surface models. These models could provide an approximate prediction of growth and OTA production.

Aspergillus ochraceus↗
PubMed2001

Alkane oxidation by a carboxylate-bridged dimanganese(III) complex.

A new manganese(II) oxamato dimer possesing an unprecedented Mn2(mu-O2CR)(mu-OH2...O2CR) core has been synthesised, structurally and magnetically characterised, and used as a catalyst for the oxidation of alkanes to alcohols and ketones by ButO2H and O2 in CH2Cl2 at rt.

Journal Article↗
PubMed1996

Flow cytometric analysis of goat milk lymphocytes: subpopulations and adhesion molecule expression.

Cytometric analysis of cells in milk from healthy goats was achieved after elimination of interfering signals from debris and dead cells by irreversible staining with ethidium monoazide. Some 61% of milk lymphocytes are CD8+ T cells, 17% are CD4+ and about 20% of these express class II antigens: less than 4% are B cells. Compared with blood, the CD4/CD8 ratio was inverted and fewer lymphocytes expressed CD4SR or L-selectin. Monoclonal antibodies to ovine integrins recognised the caprine alpha 4 chain on most lymphocytes from milk or blood, while beta 1 was more frequent on milk cells.

Animals↗
PubMed1980

Fat-modified menu's ongoing success noted.

In 1972, a hospital food service introduced a fat-modified selective cycle menu program for its patients, staff members, and visitors. Goals and implementation are discussed.

Attitude of Health Personnel↗
PubMed1980

Experience in changing food habits of hyperlipidemic men and women.

In this study, the following were planned and tested: Methods of changing adult eating habits to conform with dietary principles for lowering serum lipids; a method to assess adherence to dietary modifications; and use of nutrition aides as instructors. Six slide-tape units--tested by individual, group, and self-teaching methods, and a combination of these--were effective as judged by such indicators as lowered serum cholesterol, reduced intake of saturated fat and dietary cholesterol, and increased intake of polyunsaturated fat. The Diet Achievement Score is an effective tool for assessing adherence. Nutrition aides proved useful in this study, when effectively supervised by professional nutritionists.

Black or African American↗
PubMedDate not supplied

[Ureteral triplicity: trifid ureter with ipsilateral ureterocele and renal dysplasia in an adult with testicular seminoma].

Ureteral triplicity is a rare abnormality of which there are less than a hundred cases reported up to date. The possible absence of clinical signs can explain why this malformation passes unnoticed specially when there are blind branches and dysplastic renal segments. The paper presents the case of a 43 year-old male, attending the clinic on a testicle tumour consultation, in which in spite of the previously mentioned circumstances a preoperative diagnosis of trifid ureter with ipsilateral ureterocele and renal dysplasia was reached owing to the use of C.A.T.

Abnormalities, Multiple↗
PubMedDate not supplied

[Skin metastasis as the first manifestation of dissemination of bladder cancer].

Cutaneous metastases of vesical carcinoma are an uncommon finding and generally appear amid multisystemic dissemination. We present a case of appearance of multiple cutaneous metastases in the immediate postoperative period of a patient subjected to radical cystectomy, in which this affection was the only sign of metastatic seeding. We discuss the etiopathogeny and possible evolution of similar cases.

Aged↗