Efeito residual de alguns adubos nitrogenados sobre algumas características químicas de um solo

An experiment was made in pots with four repetitions using an acid soil with poor fertility in order to test the residual values of urea fertilizer (with and without sulphur), ammonium nitrate and ammonium sulphate. In the beginning the pH were correct up to 6,0 and applications of phosphate and potassium fertilizers in quantities of 90 and 120 kg/ha of P(2)0(5)and K(2)0 were respectively done. The quantities of N were 0, 120 and 240 kg/ha. The test plant was corn (Zea mays L.). In the following year this test was repeated without pH correction and without adding nitrogenous fertilizers. In the subsequent year the same experiment was repeated making however, pH corrections in two repetitions of each treatment. After havesting the residual effects of the employed fertilizers were studied using the following items as avaluation parameters: contents of exclangeable Al and H, potencial H, pH and nitrogen of the soils. The main conclusions were as follows: a. There was no residual effect of the nitrogen treatments when the nitrogen content of the soil was taben as a reference point. b. Refering to the exchangeable Al , the treatments that received pH correction showed no residual effect of the nitrogenous fertilizers, but in the abence of the corrective the ammonium sulphate presented a con siderable effect. The others showed less pronounced effects . c. In a general way, what concerns the potencial and exchangeable H there was no residual effect of the nitrogenous fertilizers in the treatments with corrections but in those that did not receive lime there was some residual effect especially of ammonium sulphate.Foi feito um ensaio em vasos, com 4 repetições, usando terra ácida e de baixa fertilidade para testar os valores fertilizantes de uréia (com e sem enxofre), nitrato de amônio e sulfato de amônio. Fez-se, a princípio, correção do pH para 6,0 e aplicação de adubo fosfatado e potássio nas doses de 90 e 120 kg/ha de P(2)0(5) e K(2)0, respectivamente. As doses de N foram de 0, 120 e 240 kg/ha. A planta teste foi o milho. No ano seguinte o ensaio foi repetido, mas sem calagem e sem adição dos fertilizantes nitrogenados. No ano subsequente repetiu-se o ensaio anterior fazendo-se, porém, calagem em duas repetições de cada tratamento. Após a colheita do milho estudaram-se os efeitos residuais dos adubos nitrogenados em competição tomando-se como parâmetros de avaliação a produção de massa de matéria seca de partes aéreas e de plantas inteiras e conteúdos de nitrogênio das mesmas, os teores de alumínio trocável do solo, de hidrogênio potencial, hidrogênio trocável, indices pH e porcentagens de nitrogênio das terras. As principais conclusões gerais são: a. Relativamente ao Al3+ trocável, nos tratamentos que receberam calagem não houve efeito residual dos adubos nitrogenados, mas na ausência do corretivo o sulfato de amônio apresentou efeito considerável. Os demais apresentaram efeitos menos pronunciados. b. De um modo global, no que se refere ao H+ potencial e trocável não houve efeito residual dos fertilizantes nitrogenados nos tratamentos que sofreram correção da acidez, mas, naqueles que não receberam CaCO3 houve algum efeito residual, sobretudo do sulfato de amônio. c. Quando se tomou o valor pH como índice de avaliação do efeito residual, apenas o sulfato de amônio baixou o pH das terras, tanto nos tratamentos que receberam calagem como nos que não a receberam. d. Não houve efeito residual dos fertilizantes nitrogenados quando ele foi avaliado pelo teor de N do solo. e. Quando se emprega fertilizantes amoniacais com frequência, sobretudo o sulfato de amônio, deve-se atentar para a correção da acidez do solo

Efeito residual de alguns adubos nitrogenados na cultura do milho (Zea mays L.) avaliados pela produção de matéria seca

An experiment was carried out in pots with four repetitions using an acid soil with poor fertility in order to test the residual values of urea (with and without sulphur), ammonium witate and ammonium sulphate. In the begiming the pH were corrected up to 6,0 and applications of phosphate and potassium fertilizers in quantities of 90 and 120 kg/ha of P(2)0(5) and K(2)0 were respectively done. The quantities of N were 0, 120 and 240 kg/ha. The test plant was corn (Zea mays L.). In the following year this test was repetead, without pH correction and without adding nitrogenous fertilizers. In the subsequent year the same experiment was repeated making, however, pH corrections in two repetitions of each treatment. After havesting the residual effects of the employed fertilizers were studied using the dry matter productions as avaluation parameters. It was concluded that in what concerning the dry matter production of the whole plant and the root-free plant no residual effect of nitrogen was found, except in the corresponding treatments of root-free plants where the pH was not corrected.Foi feito um ensaio em vasos, com 4 repetições, usando terra ácida e de baixa fertilidade para testar os valores fertilizantes de uréia (com e sem enxofre). nitrato de amônio e sulfato de amônio. Fez-se, a princípio, correção do pH para 6,0 e apiicação de adubo fosfatado e potássio nas doses de 90 e 120 kg/ha de P2O5 e K2O, respectivamente. As doses de N foram de 0, 120 e 240 kg/ha. A planta teste foi o milho. No ano seguinte o ensaio foi repetido, mas sem calagem e sem adição dos fertilizantes nitrogenados. No ano subsequente repetiu-se o ensaio anterior fazendo-se, porém, calagem em duas repetições de cada tratamento. Após a colheita do milho estudaram-se os efeitos residuais dos adubos nitrogenados em competição tomando-se como parâmetros de avaliação a produção de massa de matéria seca de partes aéreas e de plantas inteiras e conteúdos de nitrogênio das mesmas As principais conclusões gerais são: a. No que concerne à produção de matéria seca de partes aéreas e de plantas inteiras não houve efeito residual de N, exceto nos tratamentos correspondentes às partes aéreas de plantas que não receberam calagem. b. Não houve efeito residual das fontes nitrogenadas quando se tomou como parâmetro de avaliação o conteúdo de N das plantas

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Residual effect of nitrogen fertilizer in corn culture

Foi feito um ensaio em vasos, com 4 repetições, usando terra ácida e de baixa fertilidade para avaliar os efeitos residuais de uréia (com e sem enxofre), nitrato de amônio e sulfato de amônio, na dose de 0, 120 e 240 kg N/ha, em milho, após 2 cultivos anteriores. Fez-se, a principio, correção do pH para 6,0 e aplicação de adubo fosfatado e potássico nas doses de 90 e 120 Kg/ha de P2O5 e K2O, respectivamente. As doses de N foram de 0, 120 e 240 Kg/ha. No ano seguinte o ensaio foi repetido, mas sem calagem e sem adição dos fertilizantes nitrogenados. No ano subsequente repetiu-se o ensaio anterior fazendo-se, porém, calagem em duas repetições de cada tratamento. Após a colheita do milho estudaram-se os efeitos residuais dos adubos nitrogenados em competição tomando-se como parâmetros de avaliação a produção de massa de matéria seca de partes aéreas e de plantas inteiras, conteúdos de nitrogênio das mesmas, teores de alumínio trocável no solo, de acidez potencial, hidrogênio trocável, índices pH e porcentagens de nitrogênio das terras. As principais conclusões gerais são: a. No que concerne à produção de matéria seca de partes aéreas e de plantas inteiras não houve efeito residual de N, exceto nos tratamentos correspondentes às partes aéreas de plantas que não receberam calagem. b. Não houve efeito residual das fontes nitrogenadas quando se tomou como parâmetro de avaliação o conteúdo de N das plantas. c. Relativamente ao Al3+ trocável, nos tratamentos que receberam calagem não houve efeito residual dos adubos nitrogenados, mas na ausência do corretivo o sulfato de amônio apresentou efeito considerável. Os demais apresentaram efeitos menos pronunciados. d. De um modo global, no que se refere ao H+ potencial e trocável não houve efeito residual dos fertilizantes nitrogenados nos tratamentos que sofreram correção da acidez, mas, naqueles que não receberam CaCO3 houve algum efeito residual, sobretudo do sulfato de amônio. e. Quando se tomou o valor pH corro índice de avaliação do efeito residual, apenas o sulfato de amônia baixou o pH das terras, tanto nos tratamentos que receberam calagem como nos que não a receberam. f. Não houve efeito residual dos fertilizantes nitrogenados quando ele foi avaliado pelo teor de N do solo. g. Quando se emprega fertilizantes amoniacais com frequência, sobretudo o sulfato de amônio, deve-se atentar para a correção da acidez do solo.An experiment was made in pots with four repetitions using acid soils with poor fertility, in order test the values of urea fertilizer (with and without sulphur) ammonium nitrate, ammonium sulphate. In the beginning corrections of pH were made up to 6.0 and applications of phosphate and potassium fertilizers in quantities of 90 and 120 kg/ha of P2OS and K2O respectively. The quantities of N were of 0, 120 and 240 kg/ha. The test plant was corn (Zea mays L.) the following year this teste was repeated without pH correction and without adding nitrogenous fertilizers. In the subsequent year the same experiment was repeated making, however, pH correction in two repetitions of each treatment. After the harvesting of the corn the residual effects of the nitrogenous fertilizers were studied in competition, taking as a reference point of evaluation the production of dry matter of the whole plant and the plant without the root, the content of nitrogen of these, the quantity of changeable Al3+ in the soil, the potential H+, changeable H+, differences of pH and porcentages of nitrogen of the soils. The principal general conclusions are: a. As to the production dry matter of the whole plant and the plant without the root no residual effect of nitrogen was found, except in the corresponding treatments of the plant without the root did not receive pH correction. b. There was no residual effect of the nitrogen treatments when the content of the nitrogen of the plant was taken as a reference point. c. Referring to the changeable Al3+, in the treatments that received pH correction there was no residual effect of the nitrogenous fertilizers, but in the absence of the corrective, the ammonium sulphate presented and consideravel effect. The others presented less pronounced effects. d. Generally speaking with reference to potential and changeable H+, there was no residual effect of the nitrogenous fertilizers in the treatments with corrections of the acidity, but in those that did not receive CaCO3 there was some residual effect, especially of ammonium sulphate. e. When the value of pH was studied to evaluate the residual effect of different nitrogenous treatments, only, ammonium sulphate reduced the pH of the soils, in both the treatments that received pH correction and those that did not. f. There was no residual effects of the nitrogen fertilizers when there were evaluated by the quantity of N in soil. g. When ammonium fertilizers are used frequently, especially ammonium sulphate, care must be taken as to the correction of the acidity of the soil

Niveles de pobreza en que viven los habitantes de la comunidad La Gallina, Municipio de León, Departamento de León

Tesis (Lic. en Trabajo Social)-Universidad Nacional Autónoma de Nicaragua, LeónUNAN-Leó

Do home cleaning products affect photosynthesis and oxidative metabolism in plants? Preliminary experiments.

We have performed a pilot project to determine chlorophyll contents and catalase activity in plants subjected to irrigation with solutions containing common household cleaning products. The results show that certain treatments cause a reduction in chlorophyll production and catalase activity. These experiments are designed for advanced High School students, and the preliminary results obtained deserve to be explored further in the future.This research has been carried out as part of the project “Contaminación cotidiana”, one of the initiatives of Andalucia Mejor con Ciencia supported by Fundación Descubre.Peer Reviewe

Loss of function of the chloroplast membrane K+/H+ antiporters AtKEA1 and AtKEA2 alters the ROS and NO metabolism but promotes drought stress resilience

Potassium (K) exerts key physiological functions such as osmoregulation, stomatal movement, membrane transport, protein synthesis and photosynthesis among others. Previously, it was demonstrated in Arabidopsis thaliana that the loss of function of the chloroplast K Efflux Antiporters KEA1 and KEA2, located in the inner envelope membrane, provokes inefficient photosynthesis. Therefore, the main goal of this study was to evaluate the potential impact of the loss of function of those cation transport systems in the metabolism of reactive oxygen and nitrogen species (ROS and RNS). Using 14-day-old seedlings from Arabidopsis double knock-out kea1kea2 mutants, ROS metabolism and NO content in roots and green cotyledons were studied at the biochemical level. The loss of function of AtKEA1 and AtKEA2 did not cause oxidative stress but it provoked an alteration of the ROS homeostasis affecting some ROS-generating enzymes. These included glycolate oxidase (GOX) and NADPH-dependent superoxide generation activity, enzymatic and non-enzymatic antioxidants and both NADP-isocitrate dehydrogenase and NADP-malic enzyme activities. NO content, analyzed by confocal laser scanning microscopy (CLSM), was negatively affected in both photosynthetic and non-photosynthetic organs in kea1kea2 mutant seedlings. Furthermore, the S-nitrosoglutathione reductase (GSNOR) protein expression and activity were downregulated in kea1kea2 mutants, whereas the tyrosine nitrated protein profile, analyzed by immunoblot, was unaffected but the relative expression of each immunoreactive band changed. Moreover, kea1kea2 mutants showed an increased photorespiratory pathway and stomata closure, thus promoting a higher resilience to drought stress. Data suggest that the chloroplast osmotic balance and integrity maintained by AtKEA1 and AtKEA2 are necessary to keep the balance of ROS/RNS metabolism. Moreover, these data open new questions about how endogenous NO generation might be affected by the K/H transport located in the chloroplasts.The projects PID 2019-103924 GB-I00 (MICIT) and P18-FR-1359 (Plan Andaluz de Investigación, Desarrollo e Innovación), Spain, financed the research by ASM, SGG, JMP, and FJC, and the grant BIO 2015–65056 P (MINECO, Spain) that of MNAS, PRR and KV

Phase Transformations of 5Cr-0.5Mo-0.1C Steel after Heat Treatment and Isothermal Exposure

This study consists of the experimental and numerical analysis of the phase transformations of 5Cr-0.5Mo.0.1C steel after heat treatment. The microstructure of the as-received steel comprised ferrite and bainite, which is in agreement with the microconstituents predicted by the Calphad-calculated TTT diagram. Calphad-based precipitation calculations show that the cooling stage of normalizing treatment did not cause carbide formation. In contrast, tempering at 700 °C for 15 min promotes the intergranular precipitation of Fe3C, M7C3 and M23C6 carbides, which is consistent with experimental results. Aging at 600 °C for short periods caused the precipitation of both M7C3 and M23C6 carbides; however, M23C6 is the dominant phase after prolonged aging. This is in agreement with experimental results. A rapid decrease in the steel hardness was observed after short aging, which is attributable to bainite transformation. Further reduction in hardness is associated with the diffusion-controlled coarsening of M23C6 carbide