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1.
PLoS One ; 16(10): e0258306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34618867

RESUMO

BACKGROUND: Exploring the cultural context of intergenerational continuity of warm and harsh parenting informs parents motivations to adopt specific parenting behaviours. OBJECTIVE: Parents' perceptions of being parented in the past and their current parenting as well as adolescents' perceptions of current parenting were explored applying a multi-method approach. METHODS: Following written informed consent, a total of 24 interviews with 10 families (dyads of 14 parents and ten adolescents) from Udupi taluk in southern India was conducted. In the first stage, in-depth interviews were conducted with parent participants (Generation 1 (G1)) and in the second stage, adolescents (Generation 2 (G2)) participated in the photovoice component. Multiple forms of data including photographs, journals and interviews facilitated using the SHOWeD model were collected and were analysed thematically using ATLAS.ti(v.8). RESULTS: Subtle changes in reinforcing culture-specific gender norms between generations were elicited. Differences in communication, granting autonomy to female adolescents, and in disciplining methods between G1 and G2 were observed. Warm parenting was transmitted between generations while harsh parenting in G1 in the presence of external social support was discarded in favor of warm parenting in G2. CONCLUSION: We provide evidence for perceptions of parenting and adolescent behaviors across two generations. Transmission of warm parenting and interruption in the cycle of harsh parenting in the presence of external social support were significant findings. Related theoretical and methodological applications are discussed.


Assuntos
Comportamento Infantil , Educação Infantil , Relação entre Gerações , Poder Familiar , Adolescente , Comportamento do Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pais/psicologia , Punição
2.
J Hazard Mater ; 396: 122595, 2020 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-32298868

RESUMO

Decontamination of oil spills from coastal wetland soils requires a delicate approach. A microcosm study was carried out to investigate the impact of integrated application of biochar, rhamnolipid (RL) biosurfactant and nitrogen (N) on petroleum hydrocarbon remediation in a Louisiana coastal saline marsh and their impact on soil microbial community. The soil was artificially contaminated with crude oil and subjected to treatments of different combinations of sugarcane residue biochar, RL, and coated urea. Total petroleum hydrocarbons (TPH) in the contaminated soil were analyzed periodically using gas chromatograph and associated soil bacterial community was studied using 16 s rRNA sequencing technologies. Results showed that integrated application of biochar + RL, biochar + N, and biochar + N+RL reduced 32.3%, 73.2%, 80.9% of TPH, respectively, and exhibited synergic interaction with higher efficiency than application individually. Combined treatments showed distinct functions that biochar increased the sorption of aromatic compounds, while RL and N enhanced the degradation of heavy and light aliphatic compounds. All remediation treatments caused reduction of soil bacterial diversity while RL and N shifted the microbial community to higher abundances of Proteobacteria and Bacteroidetes, respectively. Overall, the findings of this study demonstrate the positivity of applying integrated biochar, biosurfactant, and N treatment in oil remediation in wetland soils.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Carvão Vegetal , Glicolipídeos , Hidrocarbonetos , Nitrogênio/análise , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Áreas Alagadas
3.
J Zoo Wildl Med ; 51(1): 88-95, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32212550

RESUMO

A prospective clinical trial was performed to evaluate the efficacy of haloperidol premedication prior to xylazine-ketamine anesthesia with a goal of reducing capture stress in adult male captive spotted deer (Axis axis). On the morning of the study, deer were fed a banana either containing haloperidol tablets (1 mg/kg) (haloperidol group, n = 10) or without haloperidol (placebo group, n = 10). Six hours postadministration, xylazine (3 mg/kg) and ketamine (2 mg/kg) was administered intramuscularly via a dart. Rectal temperature, heart rate, respiratory rate, and SpO2 (percent hemoglobin saturation) were recorded at 5-min intervals. Blood gas analysis was performed at time 0 (venous blood) and 10 and 20 min (arterial blood) postinduction. Serum cortisol was determined from venous blood (35 min postinduction), following which yohimbine was administered at a dose of 0.15 mg/kg intramuscular and 0.15 mg/kg intravenous. Statistical analysis of repeated measures data was performed with a two-way analysis of variance. Paired data were analyzed with a Wilcoxon rank-sum test (categorical data) or a paired t-test (continuous data). Significance was set at P ≤ 0.05, and results were expressed as mean ± SEM. There was no significant difference in induction time or recovery time between treatment groups. Rectal temperature and heart rate were significantly lower in the haloperidol group. Both groups demonstrated acidosis with venous pH being significantly lower in the placebo group when compared to the haloperidol group. Serum cortisol and arterial plasma lactate were lower in the haloperidol group indicative of reduced stress and physical exertion. Haloperidol premedication proved to be beneficial in reducing capture stress, when administered prior to xylazine-ketamine anesthesia, in spotted deer.


Assuntos
Cervos/fisiologia , Haloperidol/uso terapêutico , Pré-Medicação/veterinária , Estresse Fisiológico/efeitos dos fármacos , Tranquilizantes/uso terapêutico , Administração Oral , Anestésicos Dissociativos/administração & dosagem , Animais , Animais de Zoológico/fisiologia , Hipnóticos e Sedativos/administração & dosagem , Ketamina/administração & dosagem , Masculino , Pré-Medicação/métodos , Xilazina/administração & dosagem
4.
Sci Total Environ ; 709: 136158, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31887499

RESUMO

Recent studies have shown the effect of nitrate (NO3-) on carbon gas emissions from wetland soils that contradict thermodynamic predictions. In this study, CO2 production in three Mississippi River deltaic plain wetland soils (forest swamp, freshwater and saline marshes) with the presence of different NO3- levels (0.2, 2.0, and 3.2 mM) was evaluated in an anaerobic microcosm. Molecular composition of dissolved organic matter (DOM) of these soils was investigated using pyrolysis-GC/MS, and soil microbial community was characterized based on phosphorus lipid fatty acid (PLFA) method to elucidate the underlying mechanisms. Addition of NO3- promoted CO2 production in swamp forest soil, but inhibited CO2 emission from marsh soils. Pyrolysis-GC/MS analysis showed that swamp soil contained more polysaccharides, whereas both marsh soils had high abundance of phenolic compounds. Total PLFAs of forest swamp soil were 34% and 66% higher than freshwater and saline marsh soils, respectively. The PLFA profiles indicated different microbial distribution along a salinity gradient with the forest swamp having a higher proportion of fungi and NO3- reducers but lower sulfate (SO42-) reducers than marsh soils. Overall, the study indicated that the inherent differences in soil DOM and microbial community led to the contrasting response in soil CO2 respiration between forest swamp and marsh ecosystems to NO3- loading. These differences should be considered in determining the fate of nitrate entering Louisiana coastal wetlands from river diversions and other sources and their management.

5.
Sci Total Environ ; 686: 959-967, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31200312

RESUMO

Animal manure application in agricultural land has caused the release of steroid estrogens in the soil environment and further movement to aquatic systems. The objective of this study was to investigate the effects of biochar addition on sorption-desorption and dissipation behaviors of 17α­ethinylestradiol (EE2) in two different textured soils. A Commerce sandy loam and a Shakey clay were selected and subjected to sterilization. Soil samples with and without sterilization were reacted with a series of EE2 solutions of different concentrations for sorption followed by desorption and quantification using HPLC-MS/MS. Long-term dissipation of EE2 in the same soils was also evaluated over a 30-d incubation. Biochar amendment increased the maximum EE2 sorption capacity but decreased its water desorption in both sandy loam and clay soils. On other hand, biochar addition increased the Koc in the clay soil which had low EE2 sorption efficiency but decreased Koc in the sandy loam which had high EE2 sorption efficiency. Biochar did significantly increase both desorbable and non-extractable fractions of EE2, while it reduced the bioavailability of EE2 to microbial degradation. The dissipation of EE2 in non-sterilized soils fit to the first-order kinetic model, whereas it was better described by zero-order kinetic for sterilized soil. Biochar increased the half-life of EE2 dissipation in non-sterilized Commerce sandy loam soil by 48% (from 3.63 to 5.37 d) and in non-sterilized Sharkey clay soil by 67% (from 2.28 to 3.81 d). Overall, this study demonstrated positive impacts of biochar on the retention of estrogen hormones in soils.


Assuntos
Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Etinilestradiol/química , Poluentes do Solo/química , Argila/química , Solo/química , Poluentes do Solo/análise
6.
Waste Manag ; 78: 802-810, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32559975

RESUMO

In this study, nutrient properties and carbon sequestration potential of biochars derived from chicken manure (CM) impregnated with mineral salts (calcium chloride, magnesium chloride, ferric chloride) were evaluated. Pretreatment with mineral salts reduced phosphorus (P) availability via the formation of insoluble metal phosphate minerals. Less carbon was lost during the pyrolysis of pretreated CM, and the produced biochars (BCCa, BCMg, and BCFe) were more stable (i.e., reduced C loss during chemical oxidation and less CO2 release during incubation) than pristine biochars. Spectroscopic evidence indicated that enhanced biochar stability via metal salt pretreatment before pyrolysis was related to increased aromatization and enhanced physical protection due to the metal-oxygen interaction, together with the formation of metal mineral phases on biochar surfaces. Moreover, ferric chloride was the optimal additive, as it significantly decreased biochar P leachability and increased carbon sequestration potential.

7.
PLoS Negl Trop Dis ; 10(9): e0004965, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27618709

RESUMO

Dengue virus (DENV) is a human pathogen and its etiology has been widely established. There are many interactions between DENV and human proteins that have been reported in literature. However, no publicly accessible resource for efficiently retrieving the information is yet available. In this study, we mined all publicly available dengue-human interactions that have been reported in the literature into a database called DenHunt. We retrieved 682 direct interactions of human proteins with dengue viral components, 382 indirect interactions and 4120 differentially expressed human genes in dengue infected cell lines and patients. We have illustrated the importance of DenHunt by mapping the dengue-human interactions on to the host interactome and observed that the virus targets multiple host functional complexes of important cellular processes such as metabolism, immune system and signaling pathways suggesting a potential role of these interactions in viral pathogenesis. We also observed that 7 percent of the dengue virus interacting human proteins are also associated with other infectious and non-infectious diseases. Finally, the understanding that comes from such analyses could be used to design better strategies to counteract the diseases caused by dengue virus. The whole dataset has been catalogued in a searchable database, called DenHunt (http://proline.biochem.iisc.ernet.in/DenHunt/).


Assuntos
Bases de Dados como Assunto , Vírus da Dengue/patogenicidade , Dengue/imunologia , Dengue/metabolismo , Interações Hospedeiro-Patógeno , Mapeamento de Interação de Proteínas , Linhagem Celular , Mineração de Dados , Conjuntos de Dados como Assunto , Vírus da Dengue/fisiologia , Humanos , Índia , Replicação Viral
8.
J Clin Orthop Trauma ; 7(3): 207-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27489418

RESUMO

BACKGROUND: Sports-related knee injuries occur commonly in athletes. However, there is no published epidemiological study from India till date. OBJECTIVES: The purpose of this study was to identify common injuries sustained by Indian athletes participating in different sports and to study various associated demographic features. A secondary objective was to investigate different factors, which may affect return to sport by the athlete. STUDY DESIGN: Cross-sectional study (observational study). STUDY CENTRE: Sports injury clinic, PGIMER, Chandigarh. METHODS: Out of 465 athletes who presented to us with sports-related knee injuries over a 5-year period, 363 athletes (from 24 different sports) with complete records were identified. Data were analysed for demographic features, type of sport, mechanism of injury, injury scenario, athlete's level of play, injury duration at presentation, injury patterns and type of management. Telephonic interviews were conducted with each athlete to enquire about return to sport and time lost in sport due to the knee injury. Factors associated with return to sport were investigated using statistical tests of association. RESULTS: Soccer was found to be the most common sport associated with knee injuries accounting for 30.6% of the injuries followed by kabaddi (20.9%). The most common mechanism was non-contact injury (64.4%). Competitive injuries were found to be significantly more than practice/training injuries (p < 0.0001). The most common injuries noted were ACL tears (n = 314) followed by meniscus injuries (n = 284) and the most common combination of injuries were an ACL tear with medial meniscus tear (n = 163). Only 39.8% of the athletes returned to sport. Mean duration of time lost in sport among those who returned to sport was 8.84 months. Return to sport was significantly associated with body mass index, level of competitiveness of the athlete and type of management (p = 0.017, 0.045 and <0.0001, respectively). CONCLUSION: Knee injuries take a huge toll on an athlete's career as observed in this study. Prevention of knee injuries is of paramount importance and more focussed epidemiological studies are needed for formulating policies to prevent sports injuries in both professional and amateur athletes. LEVEL OF EVIDENCE: IV.

9.
Chemosphere ; 142: 4-13, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26058554

RESUMO

Biochar conversion of sugarcane and rice harvest residues provides an alternative for managing these crop residues that are traditionally burned in open field. Sugarcane leaves, bagasse, rice straw and husk were converted to biochar at four pyrolysis temperatures (PTs) of 450 °C, 550 °C, 650 °C, and 750 °C and evaluated for various elemental, molecular and surface properties. The carbon content of biochars was highest for those produced at 650-750 °C. Biochars produced at 550 °C showed the characteristics of biochar that are commonly interpreted as being stable in soil, with low H/C and O/C ratios and pyrolysis fingerprints dominated by aromatic and polyaromatic hydrocarbons. At 550 °C, all biochars also exhibited maximum CEC values with sugarcane leaves biochar (SLB) > sugarcane bagasse biochar (SBB) > rice straw biochar (RSB) > rice husk biochar (RHB). The pore size distribution of biochars was dominated by pores of 20 nm and high PT increased both smaller and larger than 50 nm pores. Water holding capacity of biochars increased with PT but the magnitude of the increase was limited by feedstock types, likely related to the hydrophobicity of biochars as evident by molecular composition, besides pore volume properties of biochars. Py-GC/MS analysis revealed a clear destruction of lignin with decarboxylation and demethoxylation at 450 °C and dehydroxylation at above 550 °C. Overall, biochar molecular compositions became similar as PT increased, and the biochars produced at 550 °C demonstrated characteristics that have potential benefit as soil amendment for improving both C sequestration and nutrient dynamics.


Assuntos
Carvão Vegetal/química , Oryza/química , Saccharum/química , Solo/química , Propriedades de Superfície , Temperatura , Água/química
10.
Sci Total Environ ; 533: 329-38, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26172600

RESUMO

Nitrogen (N) fertilization affects both ammonia (NH3) and greenhouse gas (GHG) emissions that have implications in air quality and global warming potential. Different cropping systems practice varying N fertilizations. The aim of this study was to investigate the effects of applications of polymer-coated urea and urea treated with N process inhibitors: NBPT [N-(n-butyl)thiophosphoric triamide], urease inhibitor, and DCD [Dicyandiamide], nitrification inhibitor, on NH3 and GHG emissions from a cotton production system in the Mississippi delta region. A two-year field experiment consisting of five treatments including the Check (unfertilized), urea, polymer-coated urea (ESN), urea+NBPT, and urea+DCD was conducted over 2013 and 2014 in a Cancienne loam (Fine-silty, mixed, superactive, nonacid, hyperthermic Fluvaquentic Epiaquepts). Ammonia and GHG samples were collected using active and passive chamber methods, respectively, and characterized. The results showed that the N loss to the atmosphere following urea-N application was dominated by a significantly higher emission of N2O-N than NH3-N and the most N2O-N and NH3-N emissions were during the first 30-50 days. Among different N treatments compared to regular urea, NBPT was the most effective in reducing NH3-N volatilization (by 58-63%), whereas DCD the most significant in mitigating N2O-N emissions (by 75%). Polymer-coated urea (ESN) and NBPT also significantly reduced N2O-N losses (both by 52%) over urea. The emission factors (EFs) for urea, ESN, urea-NBPT, urea+DCD were 1.9%, 1.0%, 0.2%, 0.8% for NH3-N, and 8.3%, 3.4%, 3.9%, 1.0% for N2O-N, respectively. There were no significant effects of different N treatments on CO2-C and CH4-C fluxes. Overall both of these N stabilizers and polymer-coated urea could be used as a mitigation strategy for reducing N2O emission while urease inhibitor NBPT for reducing NH3 emission in the subtropical cotton production system of the Mississippi delta region.


Assuntos
Agricultura/métodos , Poluição do Ar/prevenção & controle , Amônia/análise , Fertilizantes , Ureia , Urease , Poluição do Ar/análise , Gossypium/crescimento & desenvolvimento , Mississippi , Nitrificação/efeitos dos fármacos , Solo
11.
Chemosphere ; 134: 120-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25929872

RESUMO

On April 20, 2010, the Deepwater Horizon oil platform experienced an explosion which triggered the largest marine oil spill in US history, resulting in the release of ∼795 million L of crude oil into the Gulf of Mexico. Once oil reached the surface, changes in overall chemical composition occurred due to volatilization of the smaller carbon chain compounds as the oil was transported onshore by winds and currents. In this study, the toxic effects of both fresh and weathered crude oil on denitrification rates of coastal marsh soil were determined using soil samples collected from an unimpacted coastal marsh site proximal to areas that were oiled in Barataria Bay, LA. The 1:10 ratio of crude oil:field moist soil fully coated the soil surface mimicking a heavy oiling scenario. Potential denitrification rates at the 1:10 ratio, for weathered crude oil, were 46 ± 18.4% of the control immediately after exposure and 62 ± 8.0% of the control following a two week incubation period, suggesting some adaptation of the denitrifying microbial consortium over time. Denitrification rates of soil exposed to fresh crude oil were 51.5 ± 5.3% of the control after immediate exposure and significantly lower at 10.9 ± 1.1% after a 2 week exposure period. Results suggest that fresh crude oil has the potential to more severely impact the important marsh soil process of denitrification following longer term exposure. Future studies should focus on longer-term denitrification as well as changes in the microbial consortia in response to oil exposure.


Assuntos
Desnitrificação/efeitos dos fármacos , Poluição por Petróleo , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Áreas Alagadas , México , Petróleo/análise , Solo , Poluentes Químicos da Água/análise , Tempo (Meteorologia)
12.
Chemosphere ; 91(11): 1583-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23352520

RESUMO

Veterinary antibiotics are the most heavily used pharmaceuticals in intensive animal farming operation. Their presence in the environment through application of manure and lagoon water as fertilizer in agricultural fields has generated a growing concern in recent years due to potential threat to the ecosystem and the risk they pose to human and animal health. Among the antibiotics, tylosin, a macrolide class of antibiotics, has been widely used for disease prevention and growth promotion in swine, cattle/dairy, and poultry production. To understand degradation and sorption behavior of tylosin A, a laboratory microcosm incubation study was conducted on dairy lagoon sediments suspension under different pH (5.5, 7.0, 8.5) and redox potentials (Eh at -100 mV, 0 mV, +250 mV, +350 mV). Sorption and degradation of tylosin was strongly influenced by sediment pH and redox conditions. Under acidic (pH 5.5) and reduced (Eh -100 mV) condition, tylosin persisted in the solution phase of dairy lagoon sediment suspension much longer with resident time of 77 d. Under oxidized (Eh +350 mV) condition, microbial degradation was much greater causing 68-75% of tylosin loss from the solution at pH 5.5 and 32-75% at pH 7.0 during the 20 d incubation. At pH 8.5, abiotic transformation of tylosin A into unknown degradates rather than sediment adsorption and microbial degradation was the major mechanism controlling tylosin disappearance from the solution regardless of the status of redox potentials. Overall, the results suggested that under reduced condition with low pH, tylosin will be persisted in the lagoon effluents and residue of tylosin may enter agricultural fields through the application of lagoon slurry as fertilizer.


Assuntos
Antibacterianos/metabolismo , Sedimentos Geológicos/análise , Tilosina/metabolismo , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Indústria de Laticínios , Monitoramento Ambiental , Oxirredução
13.
Sci Total Environ ; 435-436: 151-8, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22850399

RESUMO

Adequate characterization of labile organic carbon (LOC) is essential to the understanding of C cycling in soil. There has been very little evaluation about the nature of LOC characterizations in coastal wetlands, where soils are constantly influenced by different redox fluctuations and salt water intrusions. In this study, we characterized and compared LOC fractions in coastal wetland soils of the Mississippi River deltaic plain using four different methods including 1) aerobically mineralizable C (AMC), 2) cold water extractable C (CWEC), 3) hot water extractable C (HWEC), and 4) salt extractable C (SEC), as well as acid hydrolysable C (AHC) which includes both labile and slowly degradable organic C. Molecular organic C functional groups of these wetland soils were characterized by (13)C solid-state nuclear magnetic resonance (NMR). The LOC and AHC increased with soil organic C (SOC) regardless of wetland soil type. The LOC estimates by four different methods were positively and significantly linearly related to each other (R(2)=0.62-0.84) and with AHC (R(2)=0.47-0.71). The various LOC fractions accounted for ≤4.3% of SOC whereas AHC fraction represented 16-49% of SOC. AMC was influenced positively by O/N-alkyl and carboxyl C but negatively by alkyl C, whereas CWEC and SEC fractions were influenced only positively by carboxyl C but negatively by alkyl C in SOC. On the other hand, HWEC fraction was found to be only influenced positively by carbonyl C, and AHC positively by O/N-alkyl and alkyl C but negatively by aromatic C groups in SOC. Overall these relations suggested different contributions of various molecular organic C moieties to LOC in these wetlands from those often found for upland soils. The presence of more than 50% non-acid hydrolysable C suggested the dominance of relatively stable SOC pool that would be sequestered in these Mississippi River deltaic plain coastal wetland soils. The results have important implications to the understanding of the liability and refractory character of SOC in these wetlands as recent studies suggest marsh SOC to be an important C source in fueling hypoxia in the northern Gulf of Mexico.


Assuntos
Carbono/química , Compostos Orgânicos/química , Rios/química , Solo/química , Áreas Alagadas , Fracionamento Químico , Mississippi
14.
J Environ Qual ; 41(4): 1185-92, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22751061

RESUMO

The role of biochar as a soil amendment on the adsorption-desorption and transport of tylosin, a macrolide class of veterinary antibiotic, is little known. In this study, batch and column experiments were conducted to investigate the adsorption kinetics and transport of tylosin in forest and agricultural corn field soils amended with hardwood and softwood biochars. Tylosin adsorption was rapid at initial stages, followed by slow and continued adsorption. Amounts of adsorption increased as the biochar amendment rate increased from 1 to 10%. For soils with the hardwood biochar, tylosin adsorption was 10 to 18% higher than that when using the softwood biochar. Adsorption kinetics was well described by Elovich equation ( ≥ 0.921). As the percent of biochar was increased, the rates of initial reactions were generally increased, as indicated by increasing α value at low initial tylosin concentration, whereas the rates during extended reaction times were generally increased, as indicated by decreasing ß value at high initial tylosin concentration. A considerably higher amount of tylosin remained after desorption in the corn field soil than in the forest soil regardless of the rate of biochar amendment, which was attributed to the high pH and silt content of the former. The breakthrough curves of tylosin showed that the two soils with biochar amendment had much greater retardation than those of soils without biochar. The CXTFIT model for the miscible displacement column study described well the peak arrival time as well as the maximum concentration of tylosin breakthrough curves but showed some underestimation at advanced stages of tylosin leaching, especially in the corn field soil. Overall, the results indicate that biochar amendments enhance the retention and reduce the transport of tylosin in soils.


Assuntos
Antibacterianos/química , Carvão Vegetal/química , Poluentes do Solo/química , Solo/química , Tilosina/química , Adsorção , Agricultura , Árvores , Zea mays/química
15.
Chemosphere ; 76(4): 517-22, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19349060

RESUMO

Dynamics of carbon (C) gas emission from wetlands influence global C cycling. In many freshwater systems such as Louisiana freshwater marsh, soil contents of NO3(-) and SO4(2-) have increased due to nutrient loading and saltwater intrusion. This could affect C mineralization and the emission of the major greenhouse gases carbon dioxide (CO2) and methane (CH4). In this investigation, a laboratory microcosm study was carried out to elucidate the effects of NO(3)(-) and SO4(2-) on CO2 and CH4 production from a freshwater marsh soil located in the Barataria Basin of Louisiana coast, which has been subjected to the Mississippi River diversion and seawater intrusion. Composite soil samples were collected from top 50 cm marsh profile, treated with different levels of NO3(-) (0, 3.2 and 5mM) or SO4(2-) (0, 2, and 5mM) concentrations, and incubated for 214d under anaerobic conditions. The results showed that the presence of NO3(-) (especially at 3.2mM) significantly decreased CO2 productions whereas SO4(2-) did not. On the other hand, both NO(3)(-) and SO4(2-) treatments decreased CH4 production but the NO3(-) almost completely inhibited CH4 production (>99%) whereas the SO4(2-) treatments reduced CH4 production by 78-90%. The overall C mineralization rate constant under the NO3(-) presence was also low. In addition, the results revealed that a large proportion (95%) of anaerobic carbon mineralization in the untreated freshwater soil was unexplained by the reduction of any of the measured major electron acceptors.


Assuntos
Dióxido de Carbono/química , Carbono/química , Gases/química , Metano/química , Solo , Dióxido de Carbono/análise , Transporte de Elétrons , Água Doce , Metano/análise , Nitratos/química , Sulfatos/química , Áreas Alagadas
16.
Sci Total Environ ; 407(1): 471-80, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18848345

RESUMO

Capacity of a wetland to remove nitrate through denitrification is controlled by its physico-chemical and biological characteristics. Understanding these characteristics will help better to guide beneficial use of wetlands in processing nitrate. This study was conducted to determine the relationship between soil organic carbon (SOC) quality and denitrification rate in Louisiana coastal wetlands. Composite soil samples of different depths were collected from three different wetlands along a salinity gradient, namely, bottomland forest swamp (FS), freshwater marsh (FM), and saline marsh (SM) located in the Barataria Basin estuary. Potential denitrification rate (PDR) was measured by acetylene inhibition method and distribution of carbon (C) moieties in organic C was determined by 13C solid-state NMR. Of the three wetlands, the FM soil profile exhibited the highest PDR on both unit weight and unit volume basis as compared to FS and SM. The FM also tended to yield higher amount of N2O as compared to the FS and SM especially at earlier stages of denitrification, suggesting incomplete reduction of NO3(-) at FM and potential for emission of N2O. Saline marsh soil profile had the lowest PDR on the unit volume basis. Increasing incubation concentration from 2 to 10 mg NO3(-)-N L(-1) increased PDR by 2 to 6 fold with the highest increase in the top horizons of FS and SM soils. Regression analysis showed that across these three wetland systems, organic C has significant effect in regulating PDR. Of the compositional C moieties, polysaccharides positively influenced denitrification rate whereas phenolics (likely phenolic adehydes and ketonics) negatively affected denitrification rate in these wetland soils. These results could have significant implication in integrated assessment and management of wetlands for treating nutrient-rich biosolids and wastewaters, non-point source agricultural runoff, and nitrate found in the diverted Mississippi River water used for coastal restoration.


Assuntos
Substâncias Húmicas/análise , Nitratos/análise , Óxido Nitroso/análise , Áreas Alagadas , Monitoramento Ambiental , Louisiana , Polissacarídeos/análise , Salinidade , Solo/análise , Solo/normas
18.
J Assoc Physicians India ; 53: 49-51, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15857014

RESUMO

Moya Moya disease is a rare cause of stroke in adults, and is a rarity secondary to hepatitis C virus infection (HCV) and cryoglobulinemia (CG). We report such a rare association in a young patient who presented with intracerebral hemorrhage.


Assuntos
Hemorragia Cerebral Traumática/etiologia , Crioglobulinemia/complicações , Hepatite C/complicações , Doença de Moyamoya/complicações , Acidente Vascular Cerebral/etiologia , Adulto , Humanos , Masculino , Doença de Moyamoya/diagnóstico
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