168 resultados para Nitrogen impact

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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The biogeochemical processes affecting the transport and cycling of terrestrial organic carbon in coastal and transition areas are still not fully understood One means of distinguishing between the sources of organic materials contributing to particulate organic matter (POM) in Babitonga Bay waters and sediments is by the direct measurement of delta(13)C of dissolved inorganic carbon (DIC) and delta(13)C and delta(15)N in the organic constituents. An isotopic survey was taken from samples collected in the Bay in late spring of 2004. The results indicate that the delta(13)C and delta(15)N compositions of OM varied from -21.7 parts per thousand to -26 2 parts per thousand. and from + 9 2 parts per thousand. to -0 1 parts per thousand, respectively. delta(13)C from DIC ranges from +0.04 parts per thousand to -12.7 parts per thousand The difference in the isotope compositions enables the determination of three distinct end-members terrestrial, marine and urban Moreover, the evaluation of source contribution to the particulate organic matter (POM) in the Bay, enables assessment of the anthropogenic impact. Comparing the depleted values of delta(13)C(DIC) and delta(13)C(POC) it is possible to further understand the carbon dynamic within Babitonga Bay (C) 2010 Elsevier BV All rights reserved

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The effects of combined nitrogen and sulphur fertilisation on the dynamics of leaf and tiller appearance in Marandu palisadegrass (Brachiaria brizantha cv. Marandu) and its impact on dry matter production were evaluated in a greenhouse study. Grass seedlings were grown in pots filled with a soil classified as an Entisol and were harvested after 43 days, a further 35 days and finally after 48 more days. Five rates of N (0, 100, 200, 300 and 400 mg/dm(3)) and 5 rates of S (0, 10, 20, 30 and 40 mg/dm(3)) were tested in an incomplete factorial design with 4 replications. Leaf and tiller development were monitored every 3 days by counting the appearance of recently expanded leaves and new basal tillers. The phyllochron and thermal time between appearance of tillers decreased as N and S fertiliser levels increased to about 300 and 25 mg/dm(3), respectively, then tended to increase. In contrast, leaf and tiller appearance rates increased with the supply of these nutrients to similar levels, then tended to decline. Leaf and tiller production and dry matter yields were affected by both N and S levels, with the role of S increasing as the growth phases increased.

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Glucose and fructose fermentations by industrial yeasts strains are strongly affected by both the structural complexity of the nitrogen Source and the availability of oxygen. In this Study two Saccharomyces cerevisiae industrial wine strains were grown, under shaken and static conditions, in a media containing either a) 20% (w/v) glucose, or b) 10% (w/v) fructose and 10% (w/v) glucose or c) 20% (w/v) fructose, all supplemented with nitrogen Sources varying from a single ammonium salt (ammonium Sulfate) to free amino acids (casamino acids) and peptides (peptone). Data Suggest that 1 complex Structured nitrogen source is not submitted to the same control mechanisms as those involved in the utilization of simpler structured nitrogen Sources, and mutual interaction between carbon and nitrogen Sources, including the mechanisms involved ill the regulation of aerobic/anaerobic metabolism, may play in important role in defining yeast fermentation performance and the differing response to the structural complexity of the nitrogen Source, with a strong impact oil fermentation performance.

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Based on the fact that streamwater quality reflects landscape conditions, the objectives of this study were: to investigate nitrogen (N), carbon (C), and major ion concentrations in six streams crossing minimally disturbed Atlantic Forest areas, with similar geomorphological characteristics; to determine N and C fluxes in one of these pristine streams (Indaia); and assess the impact of human activity on the biogeochemistry of two other streams in the same region, crossing urbanized areas. The distribution pattern of carbon and inorganic nitrogen dissolved forms, as well as the major ion and biogenic gas concentrations in the streamwater, was similar in pristine streams, indicating that the C and N dynamics were determined by influence of some factors, such as climate, atmospheric deposition, geology, soil type, and land covering, which were analogous in the forested watersheds. The urban streams were significantly different from the pristine streams, showing low dissolved oxygen concentrations, high respiration rates, and high concentrations of carbon dioxide, dissolved inorganic nitrogen, dissolved inorganic carbon, and major ion. These differences were attributed to anthropogenic impact on water quality, especially domestic sewage discharge. Additionally, in the Indaia stream, it was possible to observe the importance of rainfall over temporal dynamics of dissolved carbon forms, and also, the obtained specific flux of dissolved inorganic nitrogen was relatively elevated (approximately 11 kg ha(-1) year(-1)). These results reveal the influence of human activity over the biogeochemistry of coastal streams and also indicate the importance N export of Atlantic Forest to the ocean.

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The purpose of this study was to evaluate the impact and fracture resistance of acrylic resins: a heat-polymerized resin, a high-impact resin and an experimental polymethyl methacrylate with elastomer in different proportions (10, 20, 40 and 60%). 120 specimens were fabricated and submitted to conventional heat-polymerization. For impact test, a Charpy-type impact tester was used. Fracture resistance was assessed with a 3-point bending test by using a mechanical testing machine. Ten specimens were used for each test. Fracture (MPa) and impact resistance values (J.m-1) were submitted to ANOVA - Bonferroni's test - 5% significance level. Materials with higher amount of elastomer had statistically significant differences regarding to impact resistance (p < 0.05). Fracture resistance was superior (p < 0.01) for high-resistance acrylic resin. The increase in elastomer concentration added to polymethyl methacrylate raised the impact resistance and decreased the fracture resistance. Processing the material by injection decreased its resistance to impact and fracture.

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The aim of this study was to assess oral health status and its relationship with quality of life. A household population, cross-sectional study was carried out; participants were between 15 and 17 years of age (n = 247) and were examined by two calibrated dentists. Socio-economic status was classified according to ANEP-ABIPEME criteria. Clinical examinations to observe DMFT, CPI and Dean indices were performed as per WHO criteria. The Significant Caries Index (SiC) was used to evaluate polarization of the occurrence of caries among participants of the tercile with higher DMF-T. The OHIP instrument was used to measure quality of life. The Spearman and Mann-Whitney tests were used for assessing correlations (5% significance level). Examinations were carried out in 117 (47.37%) females and in 130 (52.63%) males. Of the examined participants, 45.75% were classified as belonging to socio-economic class C. Caries occurrence was observed in 218 subjects (88.26%); the mean DMFT was 5.40. The SiC index was 9.97. Almost half (47.77%) of the participants examined did not present sextants affected by periodontal disease. Of the participants examined, 80.16% presented absence of fluorosis. The mean OHIP was 3.95. The following correlations were observed: a positive and statistically significant correlation between the highest score in the OHIP and decayed teeth; a positive correlation with threshold significance between OHIP and DMFT; an inverse correlation between intact teeth and OHIP; and a positive and non statistically significant correlation between SiC and OHIP (correlation coefficient = 0.13, p = 0.245). Association between the mean OHIP and the terciles was not significant (p = 0.146); there were also no associations between periodontal condition and OHIP nor were there associations between the presence of fluorosis and mean OHIP.

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The objective of this study was to compare the completion rates and performance of the Brazilian version of the Oral Health Impact Profile (OHIP14) when applied as an interview or in its original self-reported form. A convenience sample of 74 adult patients was selected in a Dental Clinic (University of Araras, Brazil). One examiner administered the instrument in both formats to participants with an interval of 2 weeks between each administration. Data about dental health condition and socioeconomic status were collected and associated with total OHIP14 scores in both formats using linear regression analyses. No differences were found in the total scores and in each subscale of the OHIP14 according to the form of administration. Higher values of completion were found in the interview format. More severe impacts were recorded in the interview format than in the questionnaire format. Higher values of total OHIP-14 scores in both formats were related to the presence of dental caries. Total OHIP14 scores were not influenced by the method of administration. However, the use of the OHIP14 in the questionnaire format may result in lower completion rates and loss of data.

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The effects were assessed of two energy sources in concentrate (ground grain corn vs. citrus pulp) and two nitrogen sources (soybean meal vs. urea) on rumen metabolism in four buffaloes and four zebu cattle (Nellore) with rumen cannula and fed in a 4 × 4 Latin square design with feeds containing 60% sugar cane. Energy supplements had no effect on the rumen ammonia concentration in cattle, but ground grain corn promoted higher ammonia level than citrus pulp in buffalo. Urea produced higher ammonia level than soybean meal in both animal species. On average, the buffaloes maintained a lower rumen ammonia concentration (11.7 mg/dL) than the cattle (14.5 mg/dL). Buffaloes had lower production of acetic acid than cattle (58.7 vs. 61.6 mol/100 mol) and higher of propionic acid (27.4 vs. 23.6 mol/100 mol). There was no difference in the butyric acid production between the buffaloes (13.6 mol/100 mol) and cattle (14.8 mol/100 mol) and neither in the total volatile fatty acids concentration (82.5 vs. 83.6 mM, respectively). The energy or nitrogen sources had no effect on rumen protozoa count in either animal species. The zebu cattle had higher rumen protozoa population (8.8 × 10(5)/mL) than the buffaloes (6.1 × 10(5)/mL). The rumen protozoa population differed between the animal species, except for Dasytricha and Charonina. The buffaloes had a lower Entodinium population than the cattle (61.0 vs 84.9%, respectively) and a greater percentage of species belonging to the Diplodiniinae subfamily than the cattle (28.6 vs. 1.4%, respectively). In cattle, ground corn is a better energy source than citrus pulp for use by Entodinium and Diplodiniinae. In the buffaloes, the Entodinium are favored by urea and Diplodiniinae species by soybean meal.

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INTRODUCTION: Excessive group 2 carbapenem use may result in decreased bacterial susceptibility. OBJECTIVE: We evaluated the impact of a carbapenem stewardship program, restricting imipenem and meropenem use. METHODS: Ertapenem was mandated for ESBL-producing Enterobacteriaceae infections in the absence of non-fermenting Gram-negative bacilli (GNB) from April 2006 to March 2008. Group 2 carbapenems were restricted for use against GNB infections susceptible only to carbapenems and suspected GNB infections in unstable patients. Cumulative susceptibility tests were done for nosocomial pathogens before and after restriction using Clinical and Laboratory Standards Institute (CLSI) guide-lines.Vitek System or conventional identification methods were performed and susceptibility testing done by disk diffusion according to CLSI.Antibiotic consumption (t-test) and susceptibilities (McNemar's test) were determined. RESULTS: The defined daily doses (DDD) of group 2 carbapenems declined from 61.1 to 48.7 DDD/1,000 patient-days two years after ertapenem introduction (p = 0.027). Mean ertapenem consumption after restriction was 31.5 DDD/1,000 patient-days. Following ertapenem introduction no significant susceptibility changes were noticed among Gram-positive cocci. The most prevalent GNB were P. aeruginosa, Klebsiella pneumoniae, and Acinetobacter spp. There was no change in P. aeruginosa susceptibility to carbapenems. Significantly improved P. aeruginosa and K. pneumoniae ciprofloxacin susceptibilities were observed, perhaps due to decreased group 2 carbapenem use. K. pneumoniae susceptibility to trimethoprim-sulfamethoxazole improved. CONCLUSION: Preferential use of ertapenem resulted in reduced group 2 carbapenem use, with a positive impact on P. aeruginosa and K. pneumoniae susceptibility.

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The aim of this study was to estimate the additional cost of treatment of a group of nosocomial infections in a tertiary public hospital. A retrospective observational cohort study was conducted by means of analyzing the medical records of 34 patients with infection after total knee arthroplasty, diagnosed in 2006 and 2007, who met the criteria for nosocomial infection according to the Centers for Disease Control and Prevention. To estimate the direct costs of treatment for these patients, the following data were gathered: length of hospital stay, laboratory tests, imaging examinations, and surgical procedures performed. Their costs were estimated from the minimum values according to the Brazilian Medical Association. The estimated cost of the antibiotics used was also obtained. The total length of stay in the ward was 976 days, at a cost of US$ 18,994.63, and, in the intensive care unit, it was 34 days at a cost of US$ 5,031.37. Forty-two debridement procedures were performed, at a cost of US$ 5,798.06, and 1965 tests (laboratory and imaging) were also performed, at a cost of US$ 15,359.25. US$ 20,845.01 was spent on antibiotics and US$ 1,735.16 on vacuum assisted closure therapy, microsurgical flaps, implant removal, spacer use, and surgical revision. The total additional cost of these cases of hospital infection in 2006 and 2007 was of US$ 91,843.75. Based on that, we demonstrate that the high cost of treatment for hospital infections emphasizes the importance of taking measures to prevent and control hospital infection.

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Carbon and nitrogen biogeochemical cycles in savannas are strongly regulated by the seasonal distribution of precipitation and pulses of nutrients released during the wetting of the dry soil and are critical to the dynamics of microorganisms and vegetation. The objective of this study was to investigate the spatial and temporal variability of C and N isotope ratios as indicators of the cycling of these elements in a cerrado sensu stricto area, within a protected area in a State Park in the state of São Paulo, Brazil. The foliar δ13C and δ15N values varied from -33.6 to -24.4 ‰ and -2.5 to 4.5 ‰, respectively. The δ13C values showed a consistent relationship with canopy height, revealing the importance of structure of the canopy over the C isotopic signature of the vegetation. Carbon isotopic variations associated with the length of the dry season indicated the importance of recent fixed C to the integrated isotopic signature of the leaf organic C. The studied Cerrado species showed a depleted foliar δ15N, but a wide range of foliar Nitrogen with no difference among canopy heights. However, seasonal variability was observed, with foliar δ15N values being higher in the transition period between dry and rainy seasons. The variation of the foliar C and N isotope ratios presented here was consistent with highly diverse vegetation with high energy available but low availability of water and N.

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Studies evaluating immune function in obese humans and experimental animals indicate that the excess adiposity is associated with impaired in immune responses. Obesity is related to a higher rate of infections and to some types of cancer. Nutritional, metabolic and endocrine factors are implicated in the immunological changes. The adipose tissue directly produces substances with various functions related to immune system. Furthermore, some investigations suggest that certain types of weight reduction strategies can alter the immune function. Nevertheless, long-term studies should be carried out to address whether these changes positively affects the ability of these obese individuals to control infections and tumor development.

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Geographic Data Warehouses (GDW) are one of the main technologies used in decision-making processes and spatial analysis, and the literature proposes several conceptual and logical data models for GDW. However, little effort has been focused on studying how spatial data redundancy affects SOLAP (Spatial On-Line Analytical Processing) query performance over GDW. In this paper, we investigate this issue. Firstly, we compare redundant and non-redundant GDW schemas and conclude that redundancy is related to high performance losses. We also analyze the issue of indexing, aiming at improving SOLAP query performance on a redundant GDW. Comparisons of the SB-index approach, the star-join aided by R-tree and the star-join aided by GiST indicate that the SB-index significantly improves the elapsed time in query processing from 25% up to 99% with regard to SOLAP queries defined over the spatial predicates of intersection, enclosure and containment and applied to roll-up and drill-down operations. We also investigate the impact of the increase in data volume on the performance. The increase did not impair the performance of the SB-index, which highly improved the elapsed time in query processing. Performance tests also show that the SB-index is far more compact than the star-join, requiring only a small fraction of at most 0.20% of the volume. Moreover, we propose a specific enhancement of the SB-index to deal with spatial data redundancy. This enhancement improved performance from 80 to 91% for redundant GDW schemas.

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OBJECTIVE: To analyze the impact on human health of exposure to particulate matter emitted from burnings in the Brazilian Amazon region. METHODS: This was an ecological study using an environmental exposure indicator presented as the percentage of annual hours (AH%) of PM2.5 above 80 μg/m3. The outcome variables were the rates of hospitalization due to respiratory disease among children, the elderly and the intermediate age group, and due to childbirth. Data were obtained from the National Space Research Institute and the Ministry of Health for all of the microregions of the Brazilian Amazon region, for the years 2004 and 2005. Multiple regression models for the outcome variables in relation to the predictive variable AH% of PM2.5 above 80 μg/m3 were analyzed. The Human Development Index (HDI) and mean number of complete blood counts per 100 inhabitants in the Brazilian Amazon region were the control variables in the regression analyses. RESULTS: The association of the exposure indicator (AH%) was higher for the elderly than for other age groups (β = 0.10). For each 1% increase in the exposure indicator there was an increase of 8% in child hospitalization, 10% in hospitalization of the elderly, and 5% for the intermediate age group, even after controlling for HDI and mean number of complete blood counts. No association was found between the AH% and hospitalization due to childbirth. CONCLUSIONS: The indicator of atmospheric pollution showed an association with occurrences of respiratory diseases in the Brazilian Amazon region, especially in the more vulnerable age groups. This indicator may be used to assess the effects of forest burning on human health.

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The present contribution explores the impact of the QUALIS metric system for academic evaluation implemented by CAPES (Coordination for the Development of Personnel in Higher Education) upon Brazilian Zoological research. The QUALIS system is based on the grouping and ranking of scientific journals according to their Impact Factor (IF). We examined two main points implied by this system, namely: 1) its reliability as a guideline for authors; 2) if Zoology possesses the same publication profile as Botany and Oceanography, three fields of knowledge grouped by CAPES under the subarea "BOZ" for purposes of evaluation. Additionally, we tested CAPES' recent suggestion that the area of Ecology would represent a fourth field of research compatible with the former three. Our results indicate that this system of classification is inappropriate as a guideline for publication improvement, with approximately one third of the journals changing their strata between years. We also demonstrate that the citation profile of Zoology is distinct from those of Botany and Oceanography. Finally, we show that Ecology shows an IF that is significantly different from those of Botany, Oceanography, and Zoology, and that grouping these fields together would be particularly detrimental to Zoology. We conclude that the use of only one parameter of analysis for the stratification of journals, i.e., the Impact Factor calculated for a comparatively small number of journals, fails to evaluate with accuracy the pattern of publication present in Zoology, Botany, and Oceanography. While such simplified procedure might appeals to our sense of objectivity, it dismisses any real attempt to evaluate with clarity the merit embedded in at least three very distinct aspects of scientific practice, namely: productivity, quality, and specificity.