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To investigate the formation and leaching potential of degradation products N,N-dimethylsulfamide (DMS) and dimethylsulfamic acid (DMSA) from cyazofamid under real-world agricultural conditions, the fungicide cyazofamid was applied in a potato crop as part of the Danish Pesticide Leaching Assessment Programme (PLAP). Leaching of DMS, DMSA, 4-chloro-5-(4-methylphenyl)-1H-imidazole-2-carbonitrile (CCIM), and 4-chloro-5-(4-methylphenyl)-1H-imidazole-2-carboxylicacid (CTCA) was monitored in water from the variably saturated zone (suction cups) and groundwater for more than two years following the applications. In total, 424 samples were analyzed for the content of the four degradation products. An additional laboratory study was executed in parallel with the field monitoring study. Here, cyazofamid was applied to soil columns and leaching of the four degradation products was studied under controlled conditions. In the EFSA conclusion on cyazofamid, CCIM and CTCA are mentioned as major relevant metabolites; DMS is not mentioned in the risk assessment and DMSA is only included in acute oral toxicity studies and an in vitro bacterial mutation assay. In contrast to the EFSA conclusion on cyazofamid, our studies showed no leaching of the two major metabolites, CTCA and CCIM, but instead, major leaching of DMS and DMSA in both the field and laboratory studies was observed. That is, both DMS and DMSA leached to the groundwater in concentrations >0.1 µg/L for more than half a year. Based on this, we suggest improvements to the current pesticide risk assessment.
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Fungicidas Industriais , Água Subterrânea , Sulfonamidas , Poluentes Químicos da Água , Água Subterrânea/química , Poluentes Químicos da Água/análise , Medição de Risco , Monitoramento Ambiental , Praguicidas/análise , Imidazóis/toxicidade , Imidazóis/análiseRESUMO
BACKGROUND AND STUDY AIMS: Biliary atresia (BA) is the most common cause of neonatal cholestasis, negatively affecting nutritional status, growth, and development. It is the most frequent paediatric indication for liver transplantation. The Kasai portoenterostomy (KPE) operation is an effective procedure with favourable outcomes when performed before two months of age. The present study aimed to assess the nutritional status of patients with biliary atresia who underwent the Kasai operation and to evaluate the effectiveness of nutritional counselling using medium-chain triglyceride (MCT) formulas and proper supplementation on their nutritional status, growth, and vitamin D levels. PATIENTS AND METHODS: This prospective observational study included 36 infants with biliary atresia who underwent Kasai portoenterostomy. All patients underwent clinical assessment, anthropometric evaluation, nutritional counselling, and an evaluation of vitamin D levels. Only compliant patients (22/36) were followed up after 3 and 6 months of nutritional counselling. RESULTS: Z-scores for weight, triceps skinfold thickness, and mid-upper arm circumference improved significantly after three months, and the height velocity Z-score improved after six months of nutritional counselling using an MCT-containing formula and supplementations. Patients who showed an improvement in cholestasis had better responses. The initial assessment revealed low serum levels of 25-hydroxyvitamin D in 77.8 %, which increased significantly (p = 0.012). CONCLUSION: Dietary intervention and supplementation with MCT and micronutrients can improve the nutritional status of children with BA following KPE.
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Atresia Biliar , Estado Nutricional , Portoenterostomia Hepática , Triglicerídeos , Humanos , Atresia Biliar/cirurgia , Portoenterostomia Hepática/métodos , Masculino , Feminino , Triglicerídeos/sangue , Lactente , Estudos Prospectivos , Vitamina D/sangue , Vitamina D/administração & dosagem , Vitamina D/análogos & derivados , Suplementos Nutricionais , Fórmulas Infantis , Estatura , Dobras CutâneasRESUMO
Contamination of rivers by nitrate and pesticides poses a risk for aquatic ecosystems in lowland catchments that are often intensively used for agriculture. Here, the hyporheic zone, the streambed underneath the stream, plays a vital role due to its efficient self-purification capacity. The present study aims to evaluate the denitrification and transformation potential of 14 pesticides and three transformation products in the hyporheic sediment from a lowland stream with a high N load and by comparing an agricultural straightened section to a natural meandering part of the stream influenced by different groundwater discharges. Batch experiments were set up to evaluate the denitrification and pesticide transformation potentials in hyporheic sediment from two depths (5-15 cm (a) and 15-25 cm (b)). Our results revealed that (i) differences between the agricultural and natural sections of the river did not influence pollutant attenuation, (ii) both the nitrate and pesticide attenuation processes were more rapid in the upper "a" layer compared to the "b" layer due to higher microbial abundance, (iii) high groundwater discharge reduced the denitrification potential while pesticide transformation was unaffected, (iv) denitrification correlated with denitrifier abundance (nirK) in the "b" layer, while this correlation was not seen in the "a" layer, and (v) a microbial community with low diversity can explain limited transformation for the majority of tested pesticides. Overall, our results suggest that high groundwater discharge zones with reduced residence time in the hyporheic zone can be an important source of pesticides and nitrate to surface water.
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Água Subterrânea , Praguicidas , Rios , Ecossistema , Desnitrificação , Nitratos/análiseRESUMO
BACKGROUND: Respiratory tract infections (RTIs) are among the most commonly encountered major public health problems, with a higher prevalence of lower RTIs among children and more generally the poor. The present study aimed to describe the pattern of respiratory tract infections in Egyptian children aged under 5 years and explore possible associations between socio-demographics and nutritional status and types of RTIs. METHODS: Over 6 months beginning in September 2018 (including one winter season), a cross-sectional, observational, epidemiological study was conducted on a sample of patients with upper and lower RTIs diagnosed clinically and/or radiologically in the outpatient clinics at Cairo University Children's Hospital in Egypt. An interview questionnaire was employed to collect socio-demographic and nutritional data. Heights/lengths and weights were measured and analyzed using the World Health Organization's (WHO) Anthro Plus [Computer Program]. Patients with pneumonia (n = 28) were compared to 97 healthy children of the same age and sex. RESULTS: The total number of children diagnosed with upper and lower respiratory infections was 611. Malnutrition was present in 12.4% of all children with upper and lower RTIs. Lower RTI and malnutrition were substantially more prevalent among children aged under 2 years (p = 0.048 and p < 0.001, respectively). The strongest predictor of lower RTI was a younger age (OR 0.797, CI 0.713-0.89, p < 0.001). CONCLUSION: At our center, approximately one-third of infections in under-fives were lower RTI. Malnutrition was one of the significant risk factors for lower RTI in children below 2 years. The nutritional status of infants and young children should be improved by encouraging exclusive breastfeeding during the first 6 months of life and strengthening the healthcare and nutritional counseling available for vulnerable children, particularly in rural regions.
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Dissemination of antibiotic resistance genes (ARGs) in aquatic environments is a concern due to human and animal health. Application of liquid manure on agricultural land is an important source of ARGs, where pathogens, antibiotic-resistant bacteria, and selective agents are released. To improve our understanding of ARGs spreading through soils, our main objective was to evaluate the effectiveness of the soil as a barrier protecting water resources. Over the course of a year, profiles and abundances of ARGs and mobile genetic elements in soil and drainage from an agricultural tile-drained clay till field were investigated upon liquid pig manure application by applying high-throughput quantitative polymerase chain reaction targeting 143 genes. The findings were as follows: (a) 97 genes were detected, where only the transposon gene tnpA-03/ IS6 was shared between the genes detected in drainage and those in acidified liquid manure or fertilized soils, indicating that liquid manure application had a limited impact on the drainage resistance profile; (b) intI1 gene was present in â¼60% of drainage samples in concentrations up to 1,634 intI1 ml-1 ; and (c) evapotranspiration from barley (Hordeum vulgare L., 'KWS Irina') and a low groundwater table appeared to reduce preferential transport to drainage during the first 3 mo of liquid manure application. Interestingly, the first preferential transport to drainage was observed immediately after the harvest of spring barley. Overall, during the monitoring year we found the soil to be an effective barrier against the spread of fecal ARGs even though the occurrence of the intI1 gene questions the barrier effect from previous years.
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Genes Bacterianos , Esterco , Animais , Antibacterianos/farmacologia , Argila , Resistência Microbiana a Medicamentos/genética , Humanos , Esterco/microbiologia , Solo , Microbiologia do Solo , SuínosRESUMO
Hyporheic sediments are influenced by physical, biological, and chemical processes due to the interactions with river water and has been shown to play an important role in the environmental fate of pesticides. Therefore, this study evaluated the bacterial degradation potential of MCPA, metolachlor and propiconazole in hyporheic sediments sampled along a 20 km long stretch of an agriculturally impacted river dominated primarily by water losing conditions. Water physicochemical parameters in the river and nearby groundwater wells were assessed along with pesticide sorption to sediments and bacterial community composition. Degradation and mineralisation batch experiments were set up from six locations (five water losing, one water gaining) using environmentally relevant concentrations of pesticides (10 µg kg-1). Highly variable DT50 values from 11 to 44 days for MCPA, 11-27 days for metolachlor (MTC) and 60-147 days for propiconazole were calculated based on ~140 day studies. Degradation of MTC led to accumulation of the transformation products MOA and MESA in batch experiments. Noteworthy, MESA was detected in the groundwater wells adjacent to the part of the river impacted by losing conditions suggesting that degradation processes in hyporheic sediments may lead to the formation of transformation products (TP) leaching towards groundwater. Further, from propiconazole was identified a persistent transformation product being different from 1,2,4-triazole. Specific calculated DT50 values could not the linked to bacterial diversity. However, generally all sediment samples were characterised by high bacterial diversity, where approximately 80% of the relative sequence abundances were < 1%, which may increase the likelihood of finding contaminant-degrading genes, thereby explaining the general high contaminant-degrading activity. The studied sediments revealed a high potential to degrade pesticides despite only being exposed to low diffuse pollutant concentrations that is similar to calculated DT50 values in agricultural soils.
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Ácido 2-Metil-4-clorofenoxiacético , Água Subterrânea , Praguicidas , Poluentes Químicos da Água , Acetamidas , Bactérias , Sedimentos Geológicos/química , Água Subterrânea/química , Rios/química , Triazóis , Água , Poluentes Químicos da Água/químicaRESUMO
Seed dressing with fungicide or insecticide is a standard procedure for growing major crops, but very little is known about the leaching risk and the general fate of pesticides from coated seeds. Triazole fungicides are commonly used seed dressing fungicides and recently, there has been increasing concern that 1,2,4-triazole, a major degradation product of several triazole fungicides, may leach to groundwater in concentrations exceeding the 0.1 µg/L threshold limit of the European Union. We therefore carried out a laboratory column experiment with commercial barley seeds coated with the triazole fungicides tebuconazole and prothioconazole to study the fate of the fungicides and their degradation products, especially 1,2,4-triazole. Our experiment showed that the fungicides themselves were relatively immobile in the soil columns, but also that leaching of 1,2,4-triazole will occur no matter if tebuconazole or prothioconazole is used as seed dressing. Relatively high 1,2,4-triazole concentrations (up to 0.8 µg/L) were measured in the column leachates, but when the experiment was terminated after 63 days, a total of only 1 % of the fungicides was recovered as 1,2,4-triazole in the leachate. Our results suggest that seed dressing pesticides should be considered together with spray applications when estimating the total 1,2,4-triazole load from agriculture and that seed dressing pesticides and their degradation products should be included when evaluating leaching risks from pesticide applications in agriculture.
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Fungicidas Industriais , Hordeum , Fungicidas Industriais/análise , Sementes/química , TriazóisRESUMO
The risk of pesticide leaching from recreational areas such as golf course turfs is not distinguished in a regulative framework within the EU where the focus is on agricultural soils. But with increasing popularity of golf, and thus, increasing number of golf courses leading to potentially increasing use of pesticides, understanding the processes determining pesticide leaching are critical to ensure optimal quality of both groundwater and golf turf. This study input the measured variation in fate properties of tebuconazole (TBZ) and MCPA as pure active ingredients and commercial products in simulations with realistic hydrological conceptualizations to investigate their implication in leaching assessments. Scenarios with (i) fluctuating and fixed groundwater levels and (ii) preferential flows including fluctuating and fixed groundwater levels were evaluated. The results showed that mobile MCPA leached in higher concentrations by a factor of 1.3 with fluctuating groundwater levels than with fixed groundwater levels. When preferential flow paths were incorporated in the models, the leaching was substantial for MCPA regardless of its formulation as active ingredient or commercial product, while in multiple simulations without preferential pathways there was no leaching of MCPA. Compared to MCPA leaching without preferential flow paths, the leaching concentrations increased up to a factor of 13.9 when preferential flows were included. With preferential flow paths, the increase in leaching concentration from fixed groundwater levels to fluctuating groundwater levels was up to a factor of 2.3 depending on the formulation of MCPA. This study demonstrated that it is imperative to assess fate parameters in the topsoil of golf courses and consider realistic groundwater BC (boundary condition) and the presence of preferential flow paths to obtain representative pesticide leaching risk assessments.
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Golfe , Água Subterrânea , Praguicidas , Poluentes do Solo , Praguicidas/análise , Solo , Poluentes do Solo/análiseRESUMO
INTRODUCTION: The final adult height (FAH) of patients with congenital adrenal hyperplasia (CAH) is often lower than the predicted adult height (PAH) using the Bayley-Pinneau (B&P) method. The aim of the current work was to test the validity of B&P in predicting FAH from a bone age (BA) measurement performed at onset of puberty. MATERIAL AND ETHODS: This was a retrospective longitudinal observational convenience single-centre study. The study included 54 patients (male and female) with classic CAH, whether salt-wasting (SW) or simple virilising (SV), who had reached FAH. The results of auxological measurements and hormonal data around the time of puberty were retrieved from files. Predicted adult height (PAH) was calculated from a BA taken at onset of puberty and compared with FAH. RESULTS: The median PAH SDS at the onset of puberty (-1.5) was significantly greater than the median FAH SDS (-2.2) (p < 0.001). The median target height SDS (-0.8) was significantly higher than the median FAH SDS (-2.2) (p < 0.001). FAH and FAH SDS were significantly worse in females (150.36 ± 7.23; -2.05 ± 1.13) than in their male counterparts (162.86 ± 3.30; -1.53 ± 0.51) (p value < 0.001; 0.048). In patients with good control, there was no difference between PAH SDS (-1.7) and FAH SDS (-1.5) (p value = 0.37). In patients with poor control (over- or under-treated) FAH SDS (-2.1) was significantly lower than PAH SDS (-1.4) (p value < 0.001). CONCLUSION: The B&P method was able to accurately predict FAH in children with classic CAH, who were medically well controlled (based on 17-hydroxyprogesterone levels), but overestimated it by a significant 0.7 SD in poorly-controlled patients.
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Hiperplasia Suprarrenal Congênita , Hiperplasia Suprarrenal Congênita/complicações , Hiperplasia Suprarrenal Congênita/diagnóstico , Adulto , Estatura , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Puberdade , Estudos RetrospectivosRESUMO
Critical illness hyperglycemia (CIH) is common in the pediatric intensive care unit (PICU). Increased glucose production, insulin resistance (IR), and pancreatic ß-cell dysfunction are responsible mechanisms. We aimed to investigate ß-cell function in the PICU and to uncover its relation to clinical and laboratory variables and ICU mortality. We prospectively recruited 91 children. Pancreatic ß-cell function was assessed by using a homeostasis model assessment (HOMA)-ß. Patients with ß-cell function <40.0% had significantly higher Pediatric Risk of Mortality III (PRISM III) scores, higher rates of a positive C-reactive protein (CRP), lower IR, and a longer hospital stay. The patients with 40-80% ß-cell function had the highest IR. Intermediate IR was found when the ß-cell function was >80%. ICU survivors had better ß-cell function than ICU non-survivors. A multivariate logistic regression analysis revealed that higher PRISM III score and HOMA-ß <80.0% were significant predictors of mortality. In conclusion, ß-cell dysfunction is prevalent among PICU patients and influences patient morbidity and mortality.
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Groundwater is an important drinking water resource. To ensure clean drinking water, managed aquifer recharge (MAR) could be an attractive solution when recharging with treated wastewater. The installation of reactive barriers, e.g. with compost or other organic materials at MAR facilities, may improve pollutant removal. To link pollutant transformation processes and microbiology in reactive barriers, we simulated infiltration through different sand-compost mixtures using laboratory columns with depth-specific sampling of water and barrier material. We also evaluated the effect of inoculation with activated sludge. Our focus was on the simultaneous removal of organic micropollutants and nitrogen species, with parallel monitoring of the development of microbial communities. During 17 weeks of operation, the columns were fed with synthetic wastewater containing five organic micropollutants (1-2 µg/L each) and ammonium (2 mg N/L). Unique communities developed in the columns in relation to barrier material, with high effects of compost addition and minor effect of inoculation. Removal of the micropollutant paracetamol (acetaminophen) occurred in all columns, while sulfamethoxazole was only removed in columns with 50% compost. By contrast, limited removal was observed for sulfadiazine, carbamazepine and diuron, with the latter two displaying transient removal, attributed sorption. Oxygen was depleted within the top few cm of the columns when compost was present, but this was sufficient to remove all ammonium through nitrification. The fate of accumulated nitrate at deeper layers depended on the fraction of compost, with more compost leading to removal of nitrate by denitrification, but also by dissimilatory nitrate reduction to ammonium, hampering the overall nitrogen removal efficiency. Introducing compost as reactive barrier in MAR facilities has a large effect on the microbial communities and processes, but whether it will provide overall cleaner water to the underlying aquifer is uncertain and will depend very much on the type of pollutant.
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Compostos de Amônio , Água Subterrânea , Poluentes Químicos da Água , Nitratos/análise , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: In children with isolated unilateral undescended testis mechanical anomalies are commonly implicated and a diagnosis of simple hypospadius implies that the rest of the external genitalia are normal. Patients with disorders of sexual development, by contrast, have other associated genital anomalies including micropenis and should be referred to the endocrinologist for hormonal assessment before surgical correction of undescended testis or hypospadius. Early diagnosis of abnormal penile size is important but proper assessment begins with defining the normal population-specific age-appropriate reference range. Anogenital distance (AGD) reflects prenatal and early postnatal testosterone levels. OBJECTIVE: The aim of our study was to establish mean reference values and percentile curves for strtetched penile length (SPL) and AGD in healthy Egyptian males from the age of one month to five years and to determine the mean monthly increase in SPL and AGDs from 1 to 13 months of age (a reflection of mini-puberty). STUDY DESIGN: This was a descriptive cross-sectional study conducted in Cairo University and Mataria Hosptals, Egypt to determine SPL and AGD in 2972 Egyptian males aged from one month to five years from October 2016-December 2018. In addition, we measured length/height, weight and body mass index. RESULTS: SPL increased gradually from a mean ± SD of 3.55 ± 0.51 cm in the first year of life to 5.52 ± 0.67 cm by five years of age with a growth from 1 to 12 months of life of 0.6 cm. SPL showed smaller values in infants 6-9 months old compared to younger infants. AGD increased from 7.48 ± 1.47 cm in the first year of life to 12.83 ± 0.58 cm by 5 years of age with a growth from 1 to 12 months of 4.34 cm. SPL and AGD Z-scores correlated positively with each other and with age (months), and Z-scores of height/length, weight and BMI (p < 0.001). DISCUSSION: The rapid increases in SPL and AGD observed in our study group in the first few months of life reflect the effects of mini-puberty. The fact that SPL and AGD correlated positively with other anthropometric measurements suggests that SPL and AGD may be controlled by nutritional and/or hormonal factors. We suggest that waning testosterone levels marking the end of minipuberty might explain smaller values for SPL in our group of 6-9 month old infants compared with younger infants. LIMITATION: We have not included children under one month old. CONCLUSION: It is important for each country to develop its own national percentile curves for all growth parameters. This will allow the physician to identify normal differences in the population and to pick up disorders at an age when intervention may yield better results We have developed percentile curves for SPL and AGD that can be used as references for Egyptian male infants and young children.
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Criptorquidismo , Doenças dos Genitais Masculinos , Canal Anal , Criança , Pré-Escolar , Estudos Transversais , Egito/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pênis , GravidezRESUMO
Small polar organic pollutants have been discovered to be great threats to the groundwater' as they often are highly mobile and persistent in the environment. 1,2,4-Triazole and N,N-dimethylsulfamide, two well-known examples of small polar compounds, are frequent pollutants of upper groundwater. Both are degradation products of several fungicides commonly or previously used in agriculture' but also in wood-preserving paints. A common trait in the analysis of these small polar compounds is the lack of sufficient pre-concentration methods to lower the limit of detection and enable quantitative analysis at nano-scale concentrations. To date, they are analyzed only by direct injection in HPLC-MS/MS, with detection limits just below the European threshold value for pesticides in groundwater of 0.1 µg/L. Based on a comprehensive method development, a solid phase extraction method was developed. As known LC methods for analysis of 1,2,4-triazole are based on Thermo Fisher's Hypercarb column, emphasis was placed on testing various carbon-based materials. The final, thoroughly validated extraction protocol is based on Supelco's ENVI-Carb Plus cartridges. With extraction recoveries close to 100% for 1,2,4-triazole and N,N-dimethylsulfamide and quantification limits of around 0.003 µg/L, the method enables extraction and quantification of polar pollutants at nano-scale concentration from groundwater samples. In addition, the method is very promising to be used for other small polar pollutants. Graphical abstract.
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BACKGROUND: Familial Mediterranean fever (FMF) is an autoinflammatory disease with potentially devastating effects on the kidney, and the chronic subclinical inflammation may also be deleterious. Further, proteinuria has been associated with chronic inflammatory states. OBJECTIVE: We aimed to probe whether red cell distribution width (RDW) can be used as a reliable indicator of subclinical disease in FMF patients. METHODS: Ninety-nine children with FMF, according to the new pediatric FMF criteria, were included in the present study. All were attack-free at the time of the study. They were compared with 44 healthy age-matched controls. For all patients and controls, the following tests were done: Complete blood count (in the form of red cell count, leukocyte count, platelet count, hemoglobin, RDW and MCV), CRP, ESR, creatinine and an estimated glomerular filtration rate (e-GFR). For patients, serum and urine albumin and albumin/creatinine ratio were also determined. Group 1 consisted of 61 patients, who were not suffering from microalbuminuria, and Group 2 consisted of 38 patients who had confirmed albuminuria. RESULTS: RDW and ESR were significantly higher in patients with FMF without microalbuminuria than in controls, while MCV was smaller in controls (p<0.05). CONCLUSION: RDW can be used as an indicator of subclinical inflammation in children with FMF. The tests are easy to perform and cheaper than more sophisticated tests. Microalbuminuria may be silent and occur on the background of normal levels of acute-phase reactants. All cases must be routinely checked for microalbuminuria.
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Índices de Eritrócitos/fisiologia , Febre Familiar do Mediterrâneo/sangue , Febre Familiar do Mediterrâneo/diagnóstico , Mediadores da Inflamação/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Febre Familiar do Mediterrâneo/epidemiologia , Feminino , Humanos , Inflamação/sangue , Inflamação/diagnóstico , Inflamação/epidemiologia , MasculinoRESUMO
Preferential flow paths in subsurface soils serve as transport routes for water, dissolved organic matter and oxygen. Little is known about bacterial communities in flow paths or in subsoils below â¼4 m. We compared communities from preferential flow paths (biopores, fractures and sand lenses) with those in adjacent matrix sediments of clayey till from the plough layer to a depth of 6 m. 16S rRNA gene-targeted community analysis showed bacterial communities of greater abundance and diversity in flow paths than in matrix sediments at all depths. Deep fracture communities contained a higher relative abundance of aerobes and plant material decomposers like Nitrospirae, Acidobacteria and Planctomycetes than adjacent matrix sediments. Similarly, analyses of the relative abundances of archaeal amoA, nirK and dsrB genes indicated transition from aerobic to anaerobic nitrogen and sulphur cycling at greater depth in preferential flow paths than in matrix sediments. Preferential flow paths in the top 260 cm contained more indicator operational taxonomic units from the plough layer community than the matrix sediments. This study indicates that the availability of oxygen and organic matter and downward transport of bacteria shape bacterial communities in preferential flow paths, and suggests that their lifestyles differ from those of bacteria in matrix communities.
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Argila/microbiologia , Microbiota , Microbiologia do Solo , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Argila/química , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Nutrientes/análise , Oxigênio/análise , RNA Ribossômico 16S/genética , Movimentos da ÁguaRESUMO
Pesticide-polluted drinking water may be remediated by inoculating waterworks sand filters with specific degrading bacteria. However, degradation efficiency is often hampered by the poor adhesion behaviour of the introduced bacteria. The phenoxy acid herbicide 4-chloro-2-methyl-phenoxy-acetic acid (MCPA) is a widespread groundwater contaminant. The aim of this study was to investigate whether specific surface characteristics of MCPA-degrading bacteria could be linked to their degrading capabilities in sand filters. Four MCPA degraders with different taxonomic affiliations and original habitats (Sphingomonas sp. PM2, Sphingomonas sp. ERG5, Burkholderia sp. TFD34, Cupriavidus sp. TFD38) were characterised with regard to their motility, cell surface hydrophobicity, biofilm formation, adhesion behaviour and ability to mineralise MCPA. Strains PM2 and ERG5 were non-motile and hydrophobic, whilst strains TFD34 and TFD38 were motile and less hydrophobic. All the strains except ERG5 showed low biofilm formation on polystyrene, although it was significantly higher on glass. PM2 was the most efficient MCPA degrader as it displayed no lag phase and reached >50 % mineralisation at all concentrations (0.0016-25 mg L-1). PM2 adhered significantly better to sand than the other strains. No link was found between motility, biofilm formation and the ability to adhere to sand. PM2 completely removed MCPA for 14 days when inoculated in sand columns with a constant inlet of 1 mg L-1 MCPA. These results demonstrate that besides the ability to degrade the contaminant, surface hydrophobicity and adherence abilities are significant parameters controlling sustained degradation in flow-through sand columns and must be considered when selecting bacteria for bioaugmentation.
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Ácido 2-Metil-4-clorofenoxiacético/metabolismo , Aderência Bacteriana , Burkholderia/fisiologia , Cupriavidus/fisiologia , Praguicidas/metabolismo , Sphingomonas/fisiologia , Purificação da Água/métodos , Biotransformação , Burkholderia/metabolismo , Cupriavidus/metabolismo , Filtração/métodos , Locomoção , Sphingomonas/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
The fungicide tebuconazole (TBZ) is used to repress fungal growth in golf greens and ensure their playability. This study determined the degradation and sorption of TBZ applied as an analytical grade compound, a commercial fungicide formulation or in combination with a surfactant product in thatch and soils below two types of greens (USGA and push-up greens) in 12-cm vertical profiles covered by three different types of turf grass. Only minor TBZ degradation was observed and it was most pronounced in treatments with the commercial fungicide product or in combination with the surfactant compared to the analytical grade compound alone. A tendency for higher TBZ sorption when applied as the formulated product and lowest sorption when applied as a formulated product in combination with the surfactant was observed, with this effect being most distinct on USGA greens. No correlation between occurrence of degradation and soil depth, green type or grass type was observed. Sorption seemed to be the main process governing the leaching risk of TBZ from the greens and a positive correlation to the organic matter content was shown. In light of these findings, organic matter content should be taken into consideration during the construction of golf courses, especially when following USGA guidelines.
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Fungicidas Industriais/química , Poluentes do Solo/química , Triazóis/química , Adsorção , Golfe , Poaceae , Solo/química , Tensoativos/químicaRESUMO
The herbicide fluazifop-P-butyl (FPB) is used against grasses in agricultural crops such as potato, oilseed rape, and sugar beet. Limited information is available in scientific literature on its environmental fate, therefore extensive monitoring at two agricultural test fields was combined with laboratory studies to determine leaching and the underlying degradation and sorption processes. Water samples from drains, suction cups, and groundwater wells showed leaching of the degradation products fluazifop-P (FP) and 2-hydroxy-5-trifluoromethyl-pyridin (TFMP) following FPB treatment. Laboratory experiments with soil from each field revealed a rapid degradation of FPB to FP. The degradation was almost exclusively microbial, and further biodegradation to TFMP occurred at a slower rate. Both degradation products were sorbed to the two soils to a small extent and were fairly persistent to degradation during the two-month incubation period. Together, the field and laboratory results from this study showed that the biodegradation of FPB in loamy soils gave rise to the production of two major degradation products that sorbed to a small extent. In this study, both degradation products leached to drainage and groundwater during precipitation. It is therefore recommended that these degradation products be included in programs monitoring water quality in areas with FPB use.
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Agricultura , Herbicidas/análise , Laboratórios , Piridinas/análise , Poluentes do Solo/análise , Solo/química , Adsorção , Meia-Vida , Concentração de Íons de Hidrogênio , Piridinas/química , Água/químicaRESUMO
OBJECTIVES: This study aims to compare insulin sensitivity, lipid profile, and blood pressure in late preterm infants born at appropriate for gestational age (AGA) and small for gestational age (SGA). STUDY DESIGN: We conducted a prospective, observational study on AGA and SGA late preterm infants. Blood pressure, fasting blood glucose, insulin, insulin-like growth factor 1 (IGF-1), insulin resistance, and lipid profile were measured on the 1st day and in the 2nd week of life. RESULTS: Overall 81 infants (41 AGA and 40 SGA) were included in the study. At the time of enrollment, there was no difference in blood pressure, insulin resistance, and lipid profile. At follow-up SGA patients had significantly decreased diastolic blood pressure (48 ± 11 mm Hg vs. 42 ± 11 mm Hg, p = 0.04), and decreased IGF-1 (139 ng/mL [119-153] vs. 124 ng/mL [115-138], p = 0.05). No linear association was found between the insulin resistance and either birth weight percentile, day of life, or average 1st week daily caloric intake. CONCLUSION: As compared with AGA, SGA late preterm infants had lower diastolic blood pressure and lower IGF-1 during the 2nd week of life, but similar insulin resistance and lipid profile. We speculate that although metabolic derangements in SGA infants could have occurred at a much earlier age in fetal life, their manifestations may not be present in the immediate postnatal life.
Assuntos
Peso ao Nascer/fisiologia , Pressão Sanguínea , Recém-Nascido Prematuro/sangue , Recém-Nascido Pequeno para a Idade Gestacional/sangue , Resistência à Insulina , Egito , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Unidades de Terapia Intensiva Neonatal , Masculino , Estudos ProspectivosRESUMO
Pesticide biodegradation is a soil microbial function of critical importance for modern agriculture and its environmental impact. While it was once assumed that this activity was homogeneously distributed at the field scale, mounting evidence indicates that this is rarely the case. Here, we critically examine the literature on spatial variability of pesticide biodegradation in agricultural soil. We discuss the motivations, methods, and main findings of the primary literature. We found significant diversity in the approaches used to describe and quantify spatial heterogeneity, which complicates inter-studies comparisons. However, it is clear that the presence and activity of pesticide degraders is often highly spatially variable with coefficients of variation often exceeding 50% and frequently displays non-random spatial patterns. A few controlling factors have tentatively been identified across pesticide classes: they include some soil characteristics (pH) and some agricultural management practices (pesticide application, tillage), while other potential controlling factors have more conflicting effects depending on the site or the pesticide. Evidence demonstrating the importance of spatial heterogeneity on the fate of pesticides in soil has been difficult to obtain but modeling and experimental systems that do not include soil's full complexity reveal that this heterogeneity must be considered to improve prediction of pesticide biodegradation rates or of leaching risks. Overall, studying the spatial heterogeneity of pesticide biodegradation is a relatively new field at the interface of agronomy, microbial ecology, and geosciences and a wealth of novel data is being collected from these different disciplinary perspectives. We make suggestions on possible avenues to take full advantage of these investigations for a better understanding and prediction of the fate of pesticides in soil.