Assessment of the main factors affecting the dynamics of nutrients in two rainfed cereal watersheds

Nutrient dynamics and factors that control nutrient exports were observed in two watersheds, namely Latxaga and La Tejería, with similar climatic and management characteristics throughout 10 years (2007-2016). Similar patterns were observed in intra-annual and inter-annual dynamics with higher NO₃^- concentration and NO₃^--N yield during the humid seasons (i.e., winters and hydrological year 2013). Regarding concentration, Latxaga showed a higher decrease of nitrate due to a higher development of vegetated areas. High discharge events produced nitrate dilution due to the presence of tile-drainage at La Tejeria. At Latxaga, where tile-drainage was not observed, an increase in concentration occurred as a response to high discharge events. Comparing both watersheds, La Tejería presented ca. 73 ± 25 mg NO₃^- L^-1 while at Latxaga, the concentration observed was almost three times lower, with ca. 21 ± 15 mg NO₃^- L^-1 throughout the study period. Similar patterns were observed for the NO₃^--N yield, with 32 kg NO₃^--N ha^-1 year^-1 and 17 kg NO₃^--N ha^-1 year^-1 at La Tejería and Latxaga, respectively. Regarding phosphorous, the observed concentrations were 0.20 ± 0.72 mg PO₄^3- L^-1 and 0.06 ± 0.38 mg PO₄^3- L^-1 at La Tejería and Latxaga, respectively, with PO₄^3--P yields being 71 kg PO₄^3--P ha^-1 year^-1 and 33 kg PO₄^3--P ha^-1 year^-1. Annual phosphate-P yield distribution in both watersheds followed similar patterns to those observed for the nitrate-N yield, with higher yields in the humid season. Regarding concentration, highly erosive rainfall that occurred in summer, mobilizing sediments and probably generating desorption of phosphorous in the stream channel, increased phosphate concentration. This research adds to the knowledge base regarding the dynamics of nutrients and the controlling factors in complex agricultural systems with Mediterranean characteristics.

Effect of brewing time and temperature on antioxidant capacity and phenols of white tea: Relationship with sensory properties

White tea is highly consumed due to its sensory properties and health benefits, although most scientific reports don't include the analysis of both properties. Therefore, the objective of the present study was to unravel the best brewing conditions for optimal extraction of the bioactive compounds and antioxidant capacity, while realising the best sensory properties. Infusions of eighty commercial teas (sold in bags or leaves) were obtained at different time-temperature ratios, studying bioactive compounds (caffeine and individual catechins), antioxidant capacity and sensory analysis. Brewing at 98 °C for 7 min was the best condition to obtain a high content of antioxidant polyphenols and pleasant sensory properties. Those teas sold in bags give rise to tea brews with almost double antioxidant capacity. In conclusion, it is very important to link sensory and chemical data to obtain optimal sensorial quality and the highest healthy properties in white tea infusions.

Assessing hillslope-channel connectivity in an agricultural catchment using rare-earth oxide tracers and random forests models

Soil erosion from agricultural areas is a large problem, because of off-site effects like the rapid filling of reservoirs. To mitigate the problem of sediments from agricultural areas reaching the channel, reservoirs and other surface waters, it is important to understand hillslope-channel connectivity and catchment connectivity. To determine the functioning of hillslope-channel connectivity and the continuation of transport of these sediments in the channel, it is necessary to obtain data on sediment transport from the hillslopes to the channels. Simultaneously, the factors that influence sediment export out of the catchment need to be studied. For measuring hillslope-channel sediment connectivity, Rare-Earth Oxide (REO) tracers were applied to a hillslope in an agricultural catchment in Navarre, Spain, preceding the winter of 2014-2015. The results showed that during the winter no sediment transport from the hillslope to the channel was detected.To test the implication of the REO results at the catchment scale, two contrasting conceptual models for sediment connectivity were assessed using a Random Forest (RF) machine learning method. The RF method was applied using a 15-year period of measured sediment output at the catchment scale. One model proposes that small events provide sediment for large events, while the other proposes that only large events cause sediment detachment and small events subsequently remove these sediments from near and in the channel. For sediment yield prediction of small events, variables related to large preceding events were the most important. The model for large events underperformed and, therefore, we could not draw any immediate conclusions whether small events influence the amount of sediment exported during large events. Both REO tracers and RF method showed that low intensity events do not contribute any sediments from the hillslopes to the channel in the Latxaga catchment. Sediment dynamics are dominated by sediment mobilisation during large (high intensity) events. Sediments are for a large part exported during those events, but the system shows a memory of the occurrence of these large events, suggesting that large amounts of sediments are deposited in and near the channel after these events. These sediments are gradually removed by small events. To better understand the delivery of sediments to the channel and how large and small events influence each other more field data on hillslope-channel connectivity and within-channel sediment dynamics is necessary.

Does bariatric surgery improve the patient's quality of life?

OBJECTIVE

The aim of this investigation was to assess the effect of malabsorptive bariatric surgery (BS) on the quality of life (QoL), applying the Nottingham Health Profile (NHP) and the bariatric analysis and reporting outcome system (BAROS).

DESIGN

A prospective cohort study was performed in 100 adult patients (> 18 years) undergoing bariatric surgery by malabsorptive technique for one year.

RESEARCH METHODS AND PROCEDURES

Patients were monitored from the beginning of the BS program until a year after the intervention, applying the NHP and the BAROS test. At baseline, the mean weight of the women was 132 ± 22 kg and the Body Mass Index (BMI) was 50.7 kg/m².

RESULTS

The values obtained from different areas applying the NHP questionnaire showed statistical significant differences (p < 0.001) with respect to baseline values. According to the BAROS test, 48% of patients lost 25-49% of weight excess and 80.8% had resolved major comorbidities at 1 yr. According to the Moorehead-Ardelt QoL score, there were major improvements in employment and self-esteem in 89% and 87% of patients, respectively, and improvements in physical activity, sexual and social relationships. According to the total mean BAROS score, the outcome was considered "very good".

CONCLUSION

NHP and BAROS questionnaires appear to be useful and easily applicable tools to assess the QoL of obese patients.

Role of secreted glyceraldehyde-3-phosphate dehydrogenase in the infection mechanism of enterohemorrhagic and enteropathogenic Escherichia coli: Interaction of the extracellular enzyme with human plasminogen and fibrinogen

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (EC 1.2.1.12) is an anchorless, multifunctional protein displayed on the surface of several fungi and Gram-positive pathogens, which contributes to their adhesion and virulence. To date a role for extracellular GAPDH in the pathogenesis of Gram-negative bacteria has not been described. The aim of this study was to analyze the extracellular localization of GAPDH in enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli strains and to examine its interaction with host components that could be related to the infection mechanism. Recombinant E. coli GAPDH was purified and polyclonal antibodies were obtained. Western blotting and immunoelectron microscopy showed that GAPDH is located on the bacterial surface and released to the culture medium of EHEC and EPEC strains. GAPDH export in these Gram-negative pathogens depends on the external medium, is not mediated by vesicles and leads to an extracellular active enzyme. Non-pathogenic E. coli strains do not secrete GAPDH. Two-dimensional electrophoresis analysis showed that in E. coli GAPDH is present at least in two major forms with different isoelectric points. Of these forms, the more basic is secreted. Purified GAPDH was found to bind human plasminogen and fibrinogen in Far-Western blot and ELISA-based assays. In addition, GAPDH remained associated with colonic Caco-2 epithelial cells after adhesion of EHEC or EPEC. These observations indicate that exported GAPDH may act as a virulence factor which could contribute to EHEC and EPEC pathogenesis. This is the first description of an extracellular localization for this enzyme, with a function other than its glycolytic role in Gram-negative pathogens.

Platelet dysfunction-eosinophilia syndrome in parasitized Venezuelan children

Platelet dysfunction was detected in six children with purpura and eosinophilia. We conducted clinical evaluations, hematologic and platelet function tests, clotting studies (bleeding time, prothrombin time, partial thromboplastin time, thrombin time, factor XIII, factor VIII, and von Willebrand factor), assays for IgG and IgM antibodies to platelets, and a search for stool parasites. Mild bleeding phenomena (ecchymoses, petechiae, epistaxis, and gingival) were transient. All children showed intestinal parasites and marked eosinophilia (mean count = 2,615.2 cells/muL, 95% confidence interval = 1,259.6-5,429.8). Main abnormalities included prolonged bleeding times (50%) and defective aggregation with collagen (100%) adrenaline (66%), or ADP (66%). Antibodies to platelets were not detected. Anti-parasite therapy reversed the hemorrhagic manifestations and normalized eosinophil counts and platelet alterations. No relationship could be established between excess eosinophils, intensity of bleeding, or type and degree of platelet abnormalities. Thrombocytopathic features mimicked the intrinsic defect of storage pool disease. The possible pathogenic roles of eosinophilia and parasitism are reviewed. This is the first report of this pathologic combination in Latin American children.

Ascorbic acid in diet supplements: loss in the manufacturing process and storage

The ascorbic acid content was determined in 25 different diet supplements commercially available to the consumer in two pharmaceutical forms (pills and ampoules). These products are widely consumed by several population groups (elderly people, sportsmen, adolescents, children, etc.). High-performance liquid chromatography was used as the analytical technique. The proposed method has been validated with good linearity, reproducibility, recovery and accuracy, and can be used in routine analyses and in quality control. The ascorbic acid content in pills ranged from 15.62 to 50.16 mg/g, and in that ampoules from 2.12 to 8.83 mg/ml. Depending on the dosage rates, these levels would represent approximately 20-50% of the daily dietary intake recommended by the National Research Council. Possible losses in the manufacturing process and stability during storage for 30 days at 40 +/- 2 degrees C without light, were tested. In relation to the ascorbic acid concentrations stated on the labels, a loss of 12.0-21.9% in pills and of 11.7-18.0% in ampoules was detected. In relation to the stability conditions, the losses are of 1.8-24.8% in pills and of 10.4-19.3% in ampoules. The pasteurisation and sterilisation processes produced a mean loss of ascorbic acid in ampoules of 2.1 and 1.4%, respectively. A statistically significant direct correlation was observed between ascorbic acid loss and content in proteins, humidity, ash, and fructose. The influence of the pharmaceutical form was also tested. Data revealed that the control of losses during the manufacturing and commercialisation process of these products is necessary to ensure the intake of vitamin C from these products by the consumer.

Zinc levels in foods from southeastern Spain: relationship to daily dietary intake

The zinc content of 300 food and 79 beverage samples was determined using flame atomic absorption spectrometry. Sample recoveries, repeatability, and analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. Mean zinc concentrations varied from 0.02 microg/ml in fresh water to 71.0 microg/g (fresh weight) in pork liver. The daily dietary intake of zinc for inhabitants of southeastern Spain was estimated to be 10.1 mg (5.5, 4.0, 0.5, and 0.1 mg Zn/day per person from foods of animal and vegetable origin, drinks, and other foods, respectively). Zinc levels found in high protein foods (meat, fish, milk products, eggs, dry fruits, cereals and legumes) were significantly higher than those found in food with a low protein content (vegetables, fruits and drinks) (p < 0.001). A significant linear correlation between zinc levels and the corresponding protein content of cereals, legumes and dry fruits was found (r = 0.754, p < 0.005). Zinc concentrations in milk samples were significantly modified by the thermal treatment (p < 0.001), and the skimming (p < 0.05) and calcium enrichment processes (p < 0.001). Shellfish zinc levels were also significantly higher than those measured in fish (p < 0.05). Mean zinc concentrations found in cheese were statistically higher than those determined in the remaining milk products (p < 0.001). Zinc levels measured in distilled beverages were also statistically lower than those found in fermented ones (p < 0.001).

Dendromesogens: liquid crystal organizations of poly(amidoamine) dendrimers versus starburst structures

A new series of liquid crystalline poly(amidoamine) (PAMAM) dendrimers is described. These dendrimers are made by attaching to the 0-, 1-, 2-, 3-, and 4-generation of PAMAM-terminal promesogenic units that carry two decyloxy chains in the 3- and 4-positions of their peripheral aromatic ring. X-ray diffraction studies show that all the compounds display a hexagonal columnar mesophase. A high density of aliphatic chains imposes a curved interface with the promesogenic units that forces the molecules to adopt a radial conformation, and therefore, the columnar structure. A model for the supramolecular organization of the different generations within the columnar mesophase is proposed based on the variation of some of the structural parameters.

Cytidine (5') diphosphocholine-induced decrease in cerebral platelet activating factor is due to inactivation of its synthesizing enzyme cholinephosphotransferase in aged rats

Levels of cerebral platelet activating factor (PAF) result from the balance between the activities of its synthesizing enzyme dithiothreitol (DTT)- insensitive cholinephosphotransferase and its degradative enzyme PAF acetylhydrolase. Cerebral fractions of aged rats (19 months) displayed higher levels of PAF acetylhydrolase isoenzymes (P<0.05; n=4), unaltered levels of DTT-insensitive cholinephosphotransferase and lower PAF levels than young animals (2 months). Cerebral fractions of aged rats treated with cytidine (5') diphosphocholine displayed lower DTT-insensitive cholinephosphotransferase (55% after 8 days of treatment with 350 mg/kg per day, P<0.05; n=4), unaltered levels of PAF acetylhydrolase and lower PAF levels than untreated control animals. Thus our data would indicate that decrease of cerebral PAF may be attributed to an activation of PAF acetylhydrolase in ageing, and to an inactivation of DTT-insensitive cholinephosphotransferase in cytidine (5') diphosphocholine treated animals.

Cytidine diphosphate choline administration activates brain cytidine triphosphate: phosphocholine cytidylytransferase in aged rats

Beneficial effects of cytidine (5') diphosphocholine (CDP-choline) administration on several diseases including brain aging, ischemia and stroke are based on an increase in membrane phospholipid turnover. We have studied the possible involvement of CTP:phosphocholine cytidylyltransferase (CT) in this mechanism by measuring its gene expression and enzyme activity in the brains of young and aged rats treated with 500 mg/kg per day of CDP-choline. Older animals showed higher (57%) of total CT activity in particulate (active) fraction than younger animals (46%). Treatment of aged animals for 8, 16, or 60 days had no effect on the CT gene expression but increased activation of the CT by translocation to membranes. The particulate fraction rose from 57% of total activity to more than 65% after 2 months of treatment. This may explain the long-term repairing effects of CDP-choline on damaged membranes of aged animals.

Effects of CDP-choline administration on brain striatum platelet-activating factor in aging rats

Cytidine 5'-diphosphocholine (CDP-choline) is a precursor in platelet-activating factor (PAF) biosynthesis and it is used in the treatment of diseases of the central nervous system. PAF levels in the striatum of aged (19 months) rats were 67% lower than those found in young (2 months) animals. Chronic treatment of aged rats with CDP-choline (500 mg/kg per day) reduced these PAF levels by more than 65% with respect to those of untreated aged rats after 8 days of treatment. PAF subsequently stabilized at these low levels as treatment continued. These results suggest that some effects of CDP-choline could be mediated by changes in brain PAF levels.

Changes in brain striatum dopamine and acetylcholine receptors induced by chronic CDP-choline treatment of aging mice

1. Spiroperidol binding (dopamine D2 receptors) and quinuclidinyl benzilate binding (muscarinic receptors) in striata of 19-month old mice was analyzed for animals that had received chronic administration of cytidine 5'-diphosphocholine (CDP-choline) incorporated into the chow consumed (100 or 500 mg kg-1 added per day) for the 7 months before they were killed. 2. Treated animals displayed an increase in the dopamine receptor densities of 11% for those receiving 100 mg kg-1 and 18% for those receiving 500 mg kg-1 as compared to the control aged animals that had received no CDP-choline. Control animals showed, from 2 months to 19 months of life, a 28% decrease in the receptor density. No change in the affinity of the receptors for spiroperidol was found in the treated or untreated animals. 3. Muscarinic acetylcholine receptor densities were also partially recovered by the same treatment in aged animals that showed a 14% decrease of these receptors in this case. The muscarinic receptor density increased 6% for the animals that received 100 mg kg-1 and 17% for the animals that received 500 mg kg-1 without any change in the affinity of the receptor for quinuclidinyl benzilate. 4. Aged animals displayed a slight increase in brain membrane fluidity as indicated by a decrease in the polarization value of the non-polar fluorophore 1,6-diphenyl-1,3,5-hexatriene. Interestingly, in the treated animals a greater increase in membrane fluidity was determined and found to be very similar for the two doses.5. It is concluded that chronic administration of CDP-choline to aged animals promoted a partial recovery of the striatum dopamine and acetylcholine receptor function normally reduced with aging, which might be explicable in terms of mechanisms involving fluidity of the brain neuronal membrane.

[Control of hydatidosis in the Province of Rio Negro, Argentina: epidemiology]

In this paper we attempt to present a general view of the situation of hydatidosis in the Province of Rio Negro, Argentina, considering the magnitude of infection in man and dog. Because of its seriousness a 10 year program for the control of hydatidosis has been carried out, which included veterinary and medical care. The number of human cases with hydatidosis in the period 1981-1988 was determined by a retrospective study of the registers of Public Health. From 1188 cases registered in the period, the annual numbers varied between 152 in 1981 and 104 in 1988. This implies an incidence rate of 40 x 100,000. The most frequent localization observed was in the liver. The average days of hospitalization has decreased to 15.8 per patient. Screening seroepidemiological surveys using DD5 allowed us to determine that the prevalence rate was in some departments of 2330 x 100,000. Also included are the results, up to now, of 10 years of field work done in the program area.