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C Paredes

Publications and source records attributed to C Paredes.

At least 19 recordsLinked to original sources
PubMed2006

Short-term carbon and nitrogen mineralisation in soil amended with winery and distillery organic wastes.

The aim of this work was to study the influence of the organic wastes derived from the winery and distillery industry (grape stalk (GS), grape marc (GM), wine lees (WL) and exhausted grape marc (EG)) and the soil type (clayey-loam (S1), loam (S2) and sandy textured (S3)) on different soil characteristics, especially the carbon and nitrogen mineralisation. The evolution of C mineralisation fitted a first-order kinetic for all amended soils. An initial increase was observed in the specific respiration (qCO(2)) at the beginning of the experiment. However, afterwards, the evolution in the qCO(2) was to tend towards the values of the control soil due to the pattern of the soil to recover its initial equilibrium status. The addition of these materials in the soils produced a slight increase of the inorganic nitrogen content, except in the case of GS and EG in most of the studied soils. The use of GS as amendment produced an inhibition in the N mineralisation in the three types of soils studied. Organic matter mineralisation was probably influenced by soil type, the sandy soil favouring more the N and C mineralisation processes than the clayey-loam and loam soils.

Carbon↗
PubMed2005

Use of composted sewage sludge in growth media for broccoli.

In this study, the use of composted sewage sludge (CSS) as a binary component with peat (P) in growth media for a horticultural crop, broccoli (Brassica oleracea var. Botryti cv. Marathon), was evaluated. Four treatments were established, based on the addition of increasing quantities of composted sewage sludge to peat (0%, 15%, 30% and 50%, v/v). Physical, physico-chemical and chemical analyses of the different mixtures of CSS and P were made. Plant growth, biomass production and macronutrient (N, P, K, Ca, Mg), micronutrient (Fe, Cu, Mn, Zn) and heavy metal (Pb, Ni, Cd, Cr) contents of plants were determined. The addition of CSS to P increased plant nutrient and heavy metal contents of plants and electrical conductivity (EC) and bulk density values of the substrates. The use of CSS did not affect the germination rate, even at 50% compost. For broccoli growth, the highest yield was obtained with the medium prepared by mixing the peat with 30% of compost; however, the mixture with the most sewage sludge compost (50%) had the greatest contents of macro and micronutrients.

Agriculture↗
PubMed2005

Characterisation of the organic matter pool in manures.

In this research, different types of animal manure were evaluated with respect to organic matter (OM), total organic carbon (C(ot)), total N (N(t)), C(ot)/N(t) ratio, water-soluble organic carbon (C(w)), organic N (N(org)), carbohydrates, C(w)/N(org) ratio, humic acid-like carbon (C(ha)), fulvic acid-like carbon (C(fa)), humification index ((C(ha)/C(ot))x100) (HI) and the C(ha)/C(fa) and NH(4)(+)-N/NO(3)(-)-N ratios. In comparison with the limits set by the Spanish legislation for organic fertilisers, most of the manures had high OM contents, moderate N(org) concentrations (except in the case of the chicken and pig manures where this parameter was high) and C(ot)/N(t) ratios above the value stated in the legislation. The study of the different fractions of organic matter showed that the horse, pig and rabbit manures had the greatest content of C(ot). However, the fraction of easily-biodegradable organic compounds (C(w)) was significantly higher in the horse, goat and chicken manures. The study also showed that, in most cases, the percentage of fulvic acid-like C was greater than that of the humic acid-like C, indicating that the organic matter of these wastes is not completely humified. Values of HI ((C(ha)/C(ot))x100) and C(ha)/C(fa) ratio in the studied manures were not significantly different. Regarding the parameters related to the organic matter stability such as C(w), carbohydrates and the C(ot)/N(t), C(w)/N(org) and NH(4)(+)-N/NO(3)(-)-N ratios, it has been determined that the organic matter of these materials was not completely stabilised. The heterogeneity in OM composition of the studied manures did not allow the formulation of simple equations for evaluation of the composition of these wastes from easily-determined parameters.

Animals↗
PubMed2005

Influence of olive mill wastewater in composting and impact of the compost on a Swiss chard crop and soil properties.

The suitability of olive mill wastewater (OMW) for composting was studied by the addition of this liquid waste to a mixture of cotton gin waste and sewage sludge, and its composting was compared with that of another pile of similar composition, but without olive mill wastewater. Both piles were composted by the Rutgers static pile system in a pilot plant. To study the effects of both composts on plant yield and soil properties, a plot experiment was carried out with Swiss chard (Beta vulgaris L. var. cicla). Five treatments were applied: mineral fertiliser and two doses (30 and 60 tons ha(-1)) of both composts. The olive mill wastewater addition produced a compost with lower organic matter and nitrate concentrations, higher electrical conductivity, and a stabilised and humified organic matter similar to that of the compost produced without olive mill wastewater. The olive mill wastewater compost application to soil did not injure plants, producing a similar plant yield to both compost without olive mill wastewater and inorganic fertiliser. Also, the accumulation of potentially toxic heavy metals in plants cultivated with organic or mineral fertilisers did not reveal significant differences. The olive mill wastewater compost application to soil also improved the chemical and physicochemical properties of the soil.

Agriculture↗
PubMed2005

Uses of winery and distillery effluents in agriculture: characterisation of nutrient and hazardous components.

Twenty-one samples of winery and distillery effluents were collected from different Spanish winery and distillery industries. Electrical conductivity, pH, redox potential, density, organic charge (chemical oxygen demand, biological oxygen demand, total, volatile and suspended solids, oxidisable organic C and polyphenols) and contents of plant nutrients and heavy metals were analysed. The aim of this work was to study the composition of these effluents and to find relationships which would make it possible to use easily determined parameters to estimate their composition. The winery wastewater (WW) and vinasse (V) showed an acidic pH, a high organic load and notable polyphenol, macronutrient, micronutrient and heavy metal contents. Some of these properties are not compatible with agricultural requirements; therefore, conditioning treatment of these liquid wastes is necessary to produce a safe, stable and easily manageable end product. Generally, in both effluent types, significant correlations were found between easily analysable parameters, such as suspended, volatile and total solids, pH, electrical conductivity, density and redox potential, and most of the parameters studied. The linear regression equations obtained permitted an immediate characterisation of the WW and V samples using these parameters.

Agriculture↗
PubMed2004

Estimation of nutrient values of pig slurries in Southeast Spain using easily determined properties.

The contents of available nutrients in pig slurries are not easy to quantify in situ without laboratory facilities, but chemical analyses using standard laboratory methods also take time and are costly and not practical for most farms. Thus, when animal slurries are applied to land, their fertiliser potential is often unknown. In addition, in the last years, the changes in the management of industrial piggeries has changed the nature of the pig slurries vg. decrease of the dry matter content, and consequently the methods and equations used for estimating the nutrient contents in these residues must be checked. In our study, slurry samples were collected from the storage tanks of 36 commercial farms in Southeast Spain. Samples were analysed for pH, electrical conductivity (EC), redox potential (RP), specific density (D), total solids (TS), sedimentable solids (SS), biological oxygen demand (BOD(5)), chemical oxygen demand (COD), total nitrogen (TKN), ammonium nitrogen (AN), organic nitrogen (ON), and total contents of phosphorus, potassium, calcium and magnesium. Relationships between major nutrient levels of pig slurries and a range of physical and chemical properties were investigated. We also analysed the variability of pig slurries according to the production stage. TKN, AN and K were closely related to EC. The P content in slurries was related more closely to solids-derived parameters such as D. The use of multiple properties to estimate nutrient contents in pig slurries, especially for AN and K, seemed unnecessary due to the limited improvement achieved with an additional property. Therefore, electrical conductivity seemed to be the most appropriate single, easily determined parameter for estimation of total and ammonium nitrogen and potassium in pig slurries, with more than 83% of the variance explained. P seemed to be the worst key nutrient for estimation using any easily determined parameter.

Animals↗
PubMed2004

Strategies for fed-batch cultivation of t-PA producing CHO cells: substitution of glucose and glutamine and rational design of culture medium.

A strategy for fed-batch cultivation of t-PA producing recombinant CHO cells is presented, based on the substitution of glucose and glutamine for slowly metabolized nutrients and in a rational design of the medium. Media for the batch and fed stages were based on the cell specific amino acid requirements, which allowed a more accurate determination of the initiation of the fed stage and the frequency of nutrient addition from then on. Salt concentration was also reduced in both media to avoid an increase in osmolality. As a consequence of this rational design, most amino acid did not accumulate significantly during the fed stage, as usually occurs when their supply is not based on cell requirements; also, lower amounts of by-products were obtained when osmolality level was kept low, that altogether increased viability, longevity and t-PA production when compared with a reference batch culture. Alternating glucose and galactose during the fed stage, allowed lactate detoxification of the cells through their own metabolism. This allowed an increase in cell growth and cell viability with respect to a fed-batch culture in which only glucose was used in the fed stage.

Animals↗
PubMed2002

Bio-degradation of olive mill wastewater sludge by its co-composting with agricultural wastes.

The use of maize straw (MS) or cotton waste (CW) as bulking agents in the composting of olive mill wastewater (OMW) sludge was compared by studying the organic matter (OM) mineralisation and humification processes during composting and the characteristics of the end products. Both composts were prepared in a pilot-plant using the Rutgers static-pile system. The use of CW instead of MS to compost OMW sludge extended both the thermophilic and bio-oxidative phases of the process, with higher degradation of polymers (mainly lignin and cellulose), a greater formation of nitrates, higher total nitrogen losses and a lower biological nitrogen fixation. The CW produced a compost with a more stabilised OM and more highly polymerised humic-like substances. In the pile with CW and OMW sludge, OM losses followed a first-order kinetic equation, due to OM degradation being greater at the beginning of the composting and remaining almost constant until the end of the process. However, in the pile with MS and OMW sludge this parameter followed a zero-order kinetic equation, since OM degraded throughout the process. The germination index indicated the reduction of phytotoxicity during composting.

Agriculture↗
PubMed2001

Respiratory effects of halothane in a patient with refractory status asthmaticus.

We describe the case of a 36 year old patient who was admitted to the intensive care unit (ICU) for an acute asthma attack that failed to respond to conventional treatment and required mechanical ventilation. The patient's condition improved after halothane was administered; treatment with this inhalational anaesthetic lasted 7 h, and the beneficial effect was obtained by employing concentrations between 0.5 and 2%. Under constant mechanical ventilator settings, a highly significant linear correlation between peak airway pressure and arterial pCO(2)(r: 0.98 P<0.001) was observed. The decrease in p(a)CO(2)induced by halothane may be explained by the diminished dead space that results from the drop in peak airway pressure. Arterial hypotension, which improved with inotropic agents, was the only complication that seemed related to the inhaled anaesthetic. The patient was extubated 24 h after her arrival to the ICU and discharged 72 h later. A causal relationship between the administration of halothane and clinical improvement is suggested.

Administration, Inhalation↗
PubMed2001

Nitrogen transformation during organic waste composting by the Rutgers system and its effects on pH, EC and maturity of the composting mixtures.

The evolution of the different forms of nitrogen during the composting of several wastes was studied, as well as its relation to the pH, electrical conductivity and parameters of maturity of the composts obtained. Four mixtures were prepared from different organic materials: sewage sludge, municipal solid waste, brewery sludge, sorghum bagasse, cotton waste and pine bark. The evolution of the different forms of nitrogen during composting depended on the material which supplied the nitrogen to the mixtures and the organic matter (OM) degradation rate during composting. The greatest concentration of ammonium was observed during the first weeks of composting, coinciding with the most intense period of OM degradation, and ammonium then decreased gradually to reach final values of below 0.04%. The use of urea as a nitrogen source in the mixtures led to high ammonium levels during the first weeks as a result of its rapid hydrolysis. The nitrification process began only when the temperature of the mixtures had dropped below 40 degrees C and its intensity depended on the quantity of ammonium present when the process began. The highest concentrations of NO3-N were always produced at the end of maturation, reaching values of 0.52%, 0.53%, 0.12% and 0.20% in the four mixtures studied. Nitrogen losses during composting depended on the materials used and on the pH values of the mixtures. Mixtures with the highest lignocellulose content showed the lowest losses (below 25%), while those containing municipal solid waste lost more than 40% of the initial content. Statistically significant correlations at a high probability level were found between the NO3-N concentration and pH and electrical conductivity. confirming that nitrification was responsible for the falling pH values and increasing electrical conductivity. The ratio of NH4-N and NO3-N concentrations was shown to be a clear indicator of the maturity of the mixtures during composting, the final values of 0.08, 0.04, 0,16 and 0.11 for the four mixtures being equal to, or below the maximum value established as a maturity index in other materials.

Biodegradation, Environmental↗
PubMed2001

Effects of olive mill wastewater addition in composting of agroindustrial and urban wastes.

In order to study the suitability of olive mill wastewater (OMW) for composting, this liquid waste was added to two different mixtures of agroindustrial and urban wastes and the composting process was compared with two other piles of similar composition, but without OMW. These four piles were studied in a pilot plant using the Rutgers static pile system. The addition of OMW produced a greater proportion of degradable organic matter or a higher degradation rate, higher electrical conductivity values, greater losses of total N and lower nitrification than in piles without OMW. Its addition also restricted the increase of the cation exchange capacity and provoked the appearance of phytotoxicity or a longer persistence of phytotoxicity. However, in general, all the composts showed increases in the cation exchange capacity, the percentage of humic acid-like carbon, the polymerisation ratio of these humic substances (which revealed that the organic matter had been humified during composting) and the germination index, the latter indicating the reduction of phytotoxicity during the process.

Agriculture↗
PubMed2001

Early introduction of cereals into children's diets as a risk-factor for grass pollen asthma.

BACKGROUND: The prevalence of asthma has increased from the 1950s to the 1990s. The relationship between diet and asthma is an area of controversy that has never been fully evaluated. Attempts at dietary prevention of asthma have produced conflicting results. We have recently identified allergens from cereals that show cross-reactivity with proteins in grass pollen. An early intake of cereals in the diet during early life might cause IgE sensitization to cereals. It is not known whether such sensitization predisposes the development of allergy to pollen. METHODS: To test this hypothesis, a cross-sectional study and an observational case-control analysis of reviewed data were carried out on 16381 patients who had been admitted to our Allergy Unit between 1989 and 1999. All the patients underwent allergy tests to identify asthma risk-factors. All information in our data base was analysed using the SPSS computer system. RESULTS: There has been an increase of 7.8% in incidences of allergic asthma and a 7.3% increase in asthma due to grass pollen in the last decade. Grass-pollen asthma was associated with sensitization to cereals. The early introduction of cereals in the diet of children was found to be a risk factor for grass-pollen asthma (OR = 5.95; 95% CI 3.89-9.10). CONCLUSIONS: These findings document the progression of allergic asthma during a decade in a large sample of people who were influenced by similar environmental conditions and studied with the same diagnostic methods. This study represents the largest database of patients in which a common food is shown to be a risk factor for asthma.

Adult↗
PubMed2001

[Pulmonary diffusion of carbon monoxide in 2 clinical situations: bronchial asthma and diabetes mellitus].

OBJECTIVE: The aim of our work has been the study and comparison of diffusion capacity of CO (DLCO) in two different clinical situations: bronchial asthma and diabetes mellitus. METHOD: We have studied 16 control subjects, 38 patients with bronchial asthma and 65 patients with diabetes mellitus. We performed CO pulmonary diffusion tests by single breath method to determine two components: membrane diffusion factor (Dm) and pulmonary capillary blood volume (Vc). RESULTS: We have found a positive correlation of FEV1 with Dm. The bronchial asthma group had a lower FEV1 and FEF25-75% and an increase in DLCO, Dm and Vc, with respect to the control group. The diabetes mellitus group presented a decrease in CVF, FEV1, DLCO and Vc, with respect to the control group. The bronchial asthma group showed a lower ratio of Dm/Vc than the control and diabetes groups. CONCLUSIONS: The bronchial asthma patients have an increase in CO pulmonary diffusion, membrane diffusion factor and pulmonary capillary volume. However, the diabetes mellitus patients present a decrease in CO pulmonary diffusion mainly due to pulmonary capillary volume.

Aged↗
PubMed1996

[Application of the distortion products register in newborns. Preliminary results].

Following the development of an up-to-date audiological technique--as it seems to be--the register of acoustic distortion products 2F1-F2, the AA. have undertaken the study of the characteristics of otoacoustic emissions in a new-born normal hearing group. They describe the features of distortion products audiogram (DP-gram) of the collective, the limitations of the test and its possible clinical appliances.

Acoustic Stimulation↗
PubMed1995

Distortion product otoacoustic emissions in healthy newborns: normative data.

Distortion product otoacoustic emissions (DPOAE) offer an alternative to transiently evoked otoacoustic emissions (TEOAE) as an audiological test. The former can be used as a screening technique, and may also provide frequency-specific information about the functional state of the cochlea. We recorded DPOAE in a group of healthy newborns to establish the characteristics of a DPOAE "audiogram" (DP-gram) in this population. The DP-gram can be obtained with characteristics quite similar to those observed in adults, with two sharp peaks of maximum amplitude at F2 frequencies of 2 kHz and 5-6 kHz, and a decline in DPOAE amplitude in midfrequencies. The results confirm the limitations of DPOAE recording for testing parts of the basilar membrane where lower frequencies are coded.

Acoustic Stimulation↗
PubMed1993

[Prognostic factors in typhoid perforation].

This retrospective study evaluated 112 patients who had undergone surgery by typhoid perforation at the Belen Hospital, Trujillo, Peru, from 1967 trough 1990 in order to identify by univariate analysis the combination of factors predictive of postoperative morbidity and mortality. All the patients had one or more of the following diagnostic criteria: bacteriologic, serologic, anatomopathologic and surgical. The surgical procedures performed were: simple closure (n = 70), intestinal resection in conjunction with primary anastomosis (n = 6), intestinal resection plus ileostomy (n = 33), whilst peritoneal drainage operations were used in 3 cases. The following parameters were evaluated: age, sex, length of history, length of perforation, low intestinal hemorrhage, leukocyte count, type of peritoneal fluid and number of perforations. The operative mortality rate for all patients was 21.4% and morbidity rate was 80.4%. Significant differences in morbidity were only found in patients with perforations over 48 hours (p < 0.05). Analysis of post-operative mortality: length of perforation over 48 hours (p < 0.001), presence of hematochezia (p < 0.01), leukopenia (p < 0.05), fecaloid peritoneal fluid (p < 0.05) or the evidence of 3 or more intestinal perforations (p < 0.05). We concluded that a surgeon must take into account all of these factors to lead to satisfactory results.

Adolescent↗
PubMed1992

Extrinsic allergic alveolitis due to exposure to esparto dust.

We here describe the case of a patient with a history of exposure to esparto grass for two and a half years, who presented with clinical symptoms, radiological signs, pulmonary function test and histological findings consistent with the diagnosis of hypersensitivity pneumonitis. Signs and symptoms reappeared after re-exposure. There are few reports of stipatosis in the world literature.

Alveolitis, Extrinsic Allergic↗