bluuebunny/crossref_metadata_2025 huggingface dataset:
Sazonalidade e estado nutricional de populações indígenas: o caso Wari', Rondônia, Brasil
Authors: Leite Maurício Soares , Santos Ricardo Ventura , Coimbra Jr. Carlos E. A.
Published: October 2007

A despeito da relevância do tema, as condições de alimentação e nutrição das populações indígenas no Brasil permanecem largamente desconhecidas. O presente estudo examina o caso de uma comunidade Wari', povo indígena localizado em Rondônia, no sudoeste amazônico. Foram realizados dois inquéritos antropométricos de modo a investigar a situação nutricional da população e analisar variações sazonais. Nos inquéritos, seis meses aparte, foram examinados 279 e 266 indivíduos com idades entre zero e 87 anos. As prevalências de baixa estatura (61,7%) e peso (51,7%) entre as crianças menores de cinco anos estão entre as mais elevadas já registradas na literatura sobre populações indígenas no Brasil. Sobrepeso e obesidade não são expressivos na população, seja qual for a faixa etária considerada. Os perfis antropométricos indicam condições mais desfavoráveis durante os meses de chuva, quando as prevalências de desnutrição em crianças aumentam e adultos de ambos os sexos apresentam menores médias de peso corporal. Aponta-se para a necessidade de se considerar a sazonalidade na definição de rotinas de vigilância nutricional e na discussão dos perfis de nutrição de povos indígenas.
Tendência na utilização de serviços odontológicos entre idosos brasileiros e fatores associados: um estudo baseado na Pesquisa Nacional por Amostra de Domicílios (1998 e 2003)
Authors: Matos Divane Leite , Lima-Costa Maria Fernanda
Published: October 2007

O objetivo deste estudo foi determinar a prevalência e os fatores associados ao uso de serviços odontológicos entre idosos brasileiros em 1998 e 2003. O modelo de Andersen & Newman foi utilizado como base conceitual da pesquisa. Participaram do estudo 28.943 e 35.040 idosos participantes da PNAD 1998 e 2003, respectivamente. As características daqueles que haviam visitado o dentista há < 1 ano foram comparadas às daqueles que visitaram o dentista há mais tempo (<1 ano) e às daqueles que jamais foram ao dentista, utilizando-se regressão logística multimonial. No período considerado, a prevalência de visitas ao dentista há < 1 ano aumentou de 13,2 para 17,4%. Características de predisposição (sexo, idade e escolaridade), de necessidade (percepção da saúde geral) e de facilitação (renda domiciliar per capita, filiação a plano de saúde, situação rural/urbana do domicílio e macrorregião de residência) apresentaram associações independentes e significantes com o uso de serviços odontológicos. Observam-se importantes desigualdades sociais associadas ao uso de serviços odontológicos por idosos, apontando para a necessidade premente de políticas que visem a redução dessas desigualdades.
Heart rate and energy expenditure during garbage collection in Rio de Janeiro, Brazil
Authors: Anjos Luiz A. , Ferreira João A. , Damião Jorginete J.
Published: October 2007

Physiological workload is used to estimate the physical demand of tasks in the workforce, but limited information is available for the various work activities in developing countries. Eighty-three randomly selected male workers participated in the present study, aimed at assessing the physiological workload of garbage collection (GC) in Rio de Janeiro, Brazil. Heart rate (HR) was obtained on four consecutive workdays. Energy expenditure (EE) was extrapolated from heart rate data based on individual laboratory-established heart rate/oxygen consumption curve in 70 workers. Mean HR during GC was 104.0 ± 11.7bpm (± SD), representing 56.9 ± 7.5% of maximum heart rate. EE was 1608.3 ± 738.5kcal for an average of 293.1 ± 103.9 minutes of work per day. Based on all measurements, work in garbage collection in Rio de Janeiro can be considered excessively heavy. These data emphasize the need to develop appropriate classification of workload to be used in health-related research and in the development of maximum acceptable work time in association with the physiological workload, particularly in developing countries.
Prevalência dos marcadores sorológicos dos vírus das hepatites B e D na área indígena Apyterewa, do grupo Parakanã, Pará, Brasil
Authors: Nunes Heloisa Marceliano , Monteiro Maria Rita de Cassia Costa , Soares Manoel do Carmo Pereira
Published: October 2007

Com o objetivo de estudar a prevalência dos vírus das hepatites B (HBV) e D (HDV), nas aldeias Apyterewa e Xingu, do grupo Parakanã, e avaliar o impacto da vacinação contra a hepatite B, iniciada nessas aldeias em 1995, foram coletadas, em 2004, 258 amostras de soro para análise dos marcadores sorológicos das hepatites B e D, por técnicas imunoenzimáticas; cujos resultados revelaram padrão de endemicidade moderada com prevalência total de infecção pelo HBV de 55,7%, com 5,4% de portadores do vírus, na aldeia Apyterewa, e de 49,5%, com 1,1% de portadores, na Xingu; 31,4% de anti-HBs+ como marcador isolado nas duas aldeias, e não foi detectada sorologia positiva para o HDV entre portadores do HBV. Caracterizamos, em base laboratorial, a presença de portadores crônicos do HBV, ausência de portadores do HDV e emergência de perfil vacinal entre os susceptíveis, confirmando a efetividade e a necessidade de manter a vacinação, principalmente no primeiro ano de vida, e, ainda, a necessidade de desenvolver vigilância epidemiológica efetiva para detecção precoce da infecção pelo HDV, entre os portadores do HBV.
Riscos percebidos e vitimização de policiais civis e militares na (in)segurança pública
Authors: Minayo Maria Cecília de Souza , Souza Edinilsa Ramos de , Constantino Patrícia
Published: October 2007

Este estudo se baseou em uma pesquisa maior que investigou características sócio-econômicas, qualidade de vida, condições de trabalho e de saúde de policiais militares e civis do Estado do Rio de Janeiro, Brasil. Para isso, foram triangulados métodos quantitativos (questionário anônimo, em amostra aleatória de conglomerados envolvendo 46 unidades policiais e 2.678 policiais) e qualitativos (18 grupos focais com 143 policiais, 24 entrevistas individuais semi-estruturadas e observações de campo). Neste artigo abordamos particularmente a vitimização e os riscos percebidos pelos policiais dentro e fora da Polícia. Os dados foram processados e analisados segundo variáveis relativas a risco. Realizamos análise de conteúdo, comparando estratos intra e entre corporações segundo eixos temáticos. Essa abordagem empírica é aqui balizada por análises de dados secundários. Evidenciamos que os policiais são as maiores vítimas do desempenho de suas atividades, sobretudo os militares e aqueles de ambas as corporações que exercem funções operacionais. Diferentes variáveis se associam à vivência de risco nas duas corporações, destacando-se as condições de trabalho, em especial, o exercício de outras atividades no período legal de descanso.
Fatores associados com a incapacidade funcional em idosos do Município de Guatambu, Santa Catarina, Brasil
Authors: Santos Kelly Antunes dos , Koszuoski Ricardo , Dias-da-Costa Juvenal Soares , Pattussi Marcos Pascoal
Published: October 2007

O objetivo deste estudo era estimar a prevalência de incapacidade funcional e seus fatores associados. Foi realizado um estudo transversal de base populacional (censo) com 352 pessoas com idade maior ou igual 60 anos do Município de Guatambu, Santa Catarina, Brasil. Entrevistas foram realizadas pelos agentes de saúde. A incapacidade funcional foi medida usando-se o índice de Barthel. A análise dos dados utilizou regressão de Poisson. A prevalência de algum tipo de incapacidade funcional (leve, moderada, grave ou total) foi igual a 30,5% (IC95%: 25,6-35,2). A incapacidade funcional foi maior (p < 0,05) nos analfabetos quando comparados aos com escolaridade mais elevada (RP = 2,21; IC95%: 1,02-4,79); nas pessoas com qualidade de vida baixa comparadas às com alta (RP = 1,83; IC95%: 1,13-2,97); nas pessoas com saúde referida ruim/moderada comparadas às com saúde boa/muito boa/ótima (RP = 1,73; IC95%: 1,11-2,69); nas pessoas aposentadas comparadas às que ainda trabalhavam (RP = 2,12; IC95%: 1,19-3,78) bem como nas pessoas com maior número de morbidades e seqüelas associadas. O estudo sugere que a capacidade funcional depende da interação de fatores multidimensionais incluindo a saúde física, independência na vida diária, aspectos econômicos e psicossociais.
Effects of hyperglycemia and aging in angiogenesis and reepithelization of colonic anastomoses in rats
Authors: Nóbrega Norton Luiz , Biondo-Simões Maria de Lourdes Pessole , Barczak Daniel , Ioshii Sérgio Ossamu
Published: October 2007

PURPOSE: To evaluate angiogenesis and reepithelization of colonic anastomoses in rats. METHODS: 82 Wistar rats, divided into: young normoglycemic, old normoglycemic and hyperglycemic. Diabetes was induced with streptozotocin. Glycemia was assessed before induction, at 24 hours and after 90 days, when a colotomy and an anastomosis were performed, assessed at days 3, 7, and 14. Samples were prepared by immuno-histochemistry (PCNA and antifactor VIII). RESULTS: Mean glycemia after 90 days streptozotocin induction was 244,95 mg/dl. Day 7, reepithelization was greater in the young group than in the old normoglycemic (p<0.0001) and old hyperglycemic (p<0.0001) groups. Day 14, the differences were significant between the young and old normoglycemic (p<0.0001) and old hyperglycemic (p<0.0001) groups. The two old groups were not significantly different. At the three periods angiogenesis was higher in the young group than in the old normoglycemic (p3=0.014; p7<0.0001; p14<0.0001) or the old hyperglycemic groups (p3=0.014, p7<0.0001; p14<0.0001). The old groups, day 3, were not different (p3=0.627), but days 7 and 14, angiogenesis was bigger in the normoglycemic group (p7=0.042; p14=0.005). CONCLUSION: Age is important in reepithelization and angiogenesis of colonic anastomoses. Hyperglycemia interferes mainly in angiogenesis.
The intestinal tract as the major source of interleukin 6 production during abdominal aortic clamping and hind limb ischaemia-reperfusion injury
Authors: Pimenta Márcio Benedito Palma , Aguilar-Nascimento José Eduardo de , Martins Dely Cristina , Silva Daniele Ribastski da , Bacelo Kátia Leston , Bocchese Isabel Cristina , Zaffani Sarai , Zaffani Elieser , Silveira Érika Alessandra Oliveira , Carmo Aracelle Victor do , Ferreira Simone Sampaio Saldanha
Published: October 2007

PURPOSE: The aim of this study was to investigate whether the hind limbs or intestinal tract is the most important initiator of the inflammatory response secondary aortic clamping and hind limb ischemia/reperfusion injury. METHODS: Blood samples of Wistar rats obtained from posterior cava vein, portal vein, and heart cavity during either laparotomy (control group, n=8) or laparotomy + 2 h of aortic clamping and bilateral hind limb ischemia (ischemia group, n=8), or 2 h after ischemia and 2 h of reperfusion (ischemia-reperfusion group, n=8) were assayed for interleukin 6 (IL-6) and C-reactive protein (CRP). RESULTS: Serum IL-6 at the heart (223.6±197.9 [10-832] pg/mL) was higher (p<0.001) than at both portal (133.08±108.52 [4-372] pg/mL) and posterior cava veins (127.58±109.15 [8-388] pg/mL). CRP was not significant different among groups. CONCLUSION: The splanchnic region is also a source of inflammatory response secondary to ischemia and reperfusion of the hind limbs.
Effects of budesonide and probiotics enemas on the systemic inflammatory response of rats with experimental colitis
Authors: Souza Mardem Machado de , Aguilar-Nascimento José Eduardo de , Dock-Nascimento Diana Borges
Published: October 2007

PURPOSE: The aim of this study was to investigate the effect of enemas containing probiotics and budesonide on the systemic inflammatory response in experimental colitis. METHODS: Fifty male Wistar rats with experimental colitis induced by 10% acetic acid enema were randomized to five groups (10 rats each) according to the treatment: group 1 - saline solution, group 2 - budesonide (0.75 mg/kg/day), group 3 - probiotics (1mg/day), group 4 - probiotics plus budesonide, and group 5 - control, with not-treated rats. The following variables were studied: body weight, serum levels of albumin, C-reactive protein and interleucine-6 (IL-6). RESULTS: All animals lost weight between the beginning and the end of the experiment (280+ 16 mg versus 249+21 mg, p< 0.001). There was a significant decrease in the serum albumin between the normal pre-induction level (3.45 + 0.49mg/dL) and the 1st day after colitis induction (1.61+051mg/dL, p< 0.001) in all treated groups when compared to the control group. C- reactive protein increased after induction and diminished on the 7th day in all groups. In the control group there was an increase in the IL-6 after colitis induction. None of the treated groups significantly differed from IL-6 pre-colitis status (p>0.05). Only probiotic rats presented a significant decrease of IL-6 than controls (0,30±0,08 mg/dL vs. 0,19±0,03 mg/dL; p<0.01). CONCLUSION: Probiotic associated with budesonida Probiotics are effective to diminished inflammatory status mediated by IL-6 in experimental colitis.
Simvastatin improves the healing of infected skin wounds of rats
Authors: Rego Amália Cínthia Meneses do , Araújo Filho Irami , Damasceno Bolívar P G L , Egito Eryvaldo Sócrates Tabosa , Silveira Ivanaldo Amâncio da , Brandão-Neto José , Medeiros Aldo Cunha
Published: October 2007

PURPOSE: This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. METHODS: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. RESULTS: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 ìm²) than in saline (2120.0 ± 327.1 ìm²). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. CONCLUSION: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising.
Effects of the basic fibroblast growth factor and its anti-factor in the healing and collagen maturation of infected skin wound
Authors: Dantas Filho Antonio Medeiros , Aguiar José Lamartine de Andrade , Rocha Luís Reginaldo de Menezes , Azevedo Ítalo Medeiros , Ramalho Esdras , Medeiros Aldo Cunha
Published: October 2007

PURPOSE: The infection is one of the main factors that affect the physiological evolution of the surgical wounds. The aim of this work is to evaluate the effects of fibroblast growth factor (FGFâ) and anti-FGFâ in the healing, synthesis and maturation of collagen when topically used on infected skin wounds of rats. METHODS: An experimental study was perfomed in 60 male Wistar rats. All animals were divided in two groups (A and B). Each group was divided in three subgroups A1, B1; A2, B2 and A3, B3. After anesthesia with pentobarbital, two open squared wounds (1cm²), 4cm distant to each other, were done in the dorsal skin of all the rats. In group A (n=30) the wounds were contaminated with multibacterial standard solution, and in group B(n=30) the wounds were maintained sterile. These wounds were named F1 (for inflammation analysis) and F2 (for collagen study). The open wounds of A1 and B1 rats were topically treated with saline solution, A2 and B2 were treated with FGFâ and subgroups A3 and B3 were treated with FGFâ and anti-FGFâ. The rats were observed until complete epitelization of F2 wounds for determination of healing time and the expression of types I and III collagen, using Picro Sirius Red staining. Inflammatory reaction in F1 wounds was studied using hematoxilineosin staining. The three variable was measured by the Image Pro-Plus Média Cybernetics software. The statistical analysis was performed by ANOVA and Tukey test, considering p<0.05 as significant. RESULTS: It was observed that infection retarded significantly (p<0.05) the time of wound scarring and the topical application of FCFb reverted the inhibition of healing caused by bacteria. The inflammatory reaction was greater in the subgroup B2 than in B1 and A3, and the difference was significant (p<0.05). It was observed greater expression of type I collagen in all the subgroups treated with FCFb, when compared with the untreated subgroups. Type III collagen was significantly decreased in wounds of B3 rats, comparing to the other subgroups. CONCLUSIONS: The FCFb accelerated the healing of open infected wounds and contributed with maturation of collagen, enhancing the type I collagen density. The anti-FCFb antibody was able to attenuate the production of both type I and III collagen.
Methyl-tert-hexyl ether and methyl-tert-octyl ether as gasoline oxygenates: Anticipating widespread risks to community water supply wells
Authors: Snelling Jeff , Barnett Mark O. , Zhao Dongye , Arey J. Samuel
Published: October 2007

The widespread contamination of groundwater resources associated with methyl-tert-butyl ether (MtBE) use has prompted a search for replacement oxygenates in gasoline. Among the alternatives currently under development are higher methyl-tert-alkyl ethers, notably methyl-tert-hexyl ether (MtHxE) and methyl-tert-octyl ether (MtOcE). As was the case with MtBE, the introduction of these ethers into fuel supplies guarantees their migration into groundwater resources. In the present study, a screening-level risk assessment compared predicted well water concentrations of these ethers to concentrations that might cause adverse effects. A physicochemical model which has been successfully applied to the prediction of MtBE concentrations in community water supply wells (CSWs) was used to predict well water concentrations of MtHxE and MtOcE. The results indicate that these ethers are likely to contaminate water supply wells at slightly lower levels than MtBE as a result of migrating from leaking underground fuel tanks to CSWs. Because very little data is available on the physicochemical and environmental properties of MtHxE and MtOcE, estimation methods were employed in conjunction with the model to predict well water concentrations. Model calculations indicated that MtHxE and MtOcE will be present in many CSWs at concentrations approaching the concentrations that have caused widespread public health concern for MtBE. Based on these results and the possibility that MtHxE and MtOcE are potential carcinogens, testing of the toxicological properties of these ethers is recommended before they are used to replace MtBE in gasoline.
Estrogen-like properties of perfluorooctanoic acid as revealed by expressing hepatic estrogen-responsive genes in rare minnows (Gobiocypris rarus)
Authors: Wei Yanhong , Dai Jiayin , Liu Min , Wang Jianshe , Xu Muqi , Zha Jinmiao , Wang Zijian
Published: October 2007

Perfluorooctanoic acid (PFOA) is an important perfluorinated compound (PFC) with various applications and has been widely disseminated in the environment, wildlife, and humans. The present study investigated the effects of waterborne PFOA on the expression of hepatic estrogen-responsive genes, vitellogenin (VTG), and estrogen receptor β (ERβ) and on the gonadal development in a freshwater rare minnow (Gobiocypris rarus). The mRNA levels of VTG and ERβ were determined using reverse transcription polymerase chain reaction (RT-PCR) techniques, and VTG protein levels were identified using enzyme-linked immunosorbent assay. A significant increase of VTG expression in the livers of both mature males and females was observed after 14 and 28 d of exposure to 3, 10, and 30 mg/L PFOA, indicating that PFOA could induce VTG synthesis. The expression of ERβ increased significantly in livers of both mature males and females after a 14-d exposure, although no difference was observed after a 28-d exposure. The development of oocytes in testes exposed to PFOA also provided evidence of estrogenic activity in males. The ovaries of PFOA-exposed females underwent degeneration, as reported in other fish species exposed to environmental estrogens. This preliminary study indicates that PFOA can disturb the activity of estrogen in mature male rare minnows by inducing hepatic estrogen-responsive genes, VTG and ERβ, and barrier female reproduction.
Metabolic fate of [14C]-2,4-dichlorophenol in tobacco cell suspension cultures
Authors: Laurent Francois , Canlet Cécile , Debrauwer Laurent , Pascal-Lorber Sophie
Published: October 2007

In plant tissues, xenobiotics often are conjugated with natural constituents such as sugars, amino acids, glutathione, and malonic acid. Usually, conjugation processes result in a decrease in the reactivity and toxicity of xenobiotics by increasing the water solubility and polarity of conjugates, and reducing their mobility. Due to their lack of an efficient excretory system, xenobiotic conjugates finally are sequestered in plant storage compartments or cell vacuoles, or are integrated as bound residues in cell walls. Chlorophenols are potentially harmful pollutants that are found in numerous natural and agricultural systems. we studied the metabolic fate of 2,4-dichlorophenol (DCP) in cell-suspension cultures of tobacco (Nicotiana tabacum L.). After a standard metabolism experiment, 48h of incubation with a [U-phenyl-14C]-DCP solution, aqueous extracts of cell suspension cultures were analyzed by high-performance liquid chromatography (HPLC). Metabolites then were isolated and their chemical structures determined by enzymatic and chemical hydrolyses, electrospray ionization-mass spectrometry in negative mode (ESI-NI), and 1H nuclear magnetic resonance analyses. The main terminal metabolites identified were DCP-glycoside conjugates, DCP-(6-O-malonyl)-glucoside, DCP-(6-O-acetyl)-glucoside, and their precursor, DCP-glucoside. More unusual and complex DCP conjugates such as an α(1→6)-glucosyl-pentose and a triglycoside containing a glucuronic acid were further characterized. All the metabolites identified were complex glycoside conjugates. However, these conjugates still may be a source of DCP in hydrolysis reactions caused by microorganisms in the environment or in the digestive tract of animals and humans. Removal of xenobiotics by glycoside conjugation thus may result in underestimation of the risk associated with toxic compounds like DCP in the environment or in the food chain.
Application of the target lipid model for deriving predicted no-effect concentrations for wastewater organisms
Authors: Redman Aaron , McGrath Joy , Febbo Eric , Parkerton Thomas , Letinski Dan , Connelly Martin , Winkelmann Douglas , Toro Dominic Di
Published: October 2007

The target lipid model (TLM) was applied to literature data from 10 microbial toxicity assays to provide a quantitative effects assessment framework for wastewater treatment plant organisms. For the nonpolar organic chemicals considered, linear relationships between the logarithm of the median effect concentrations (EC50) and log(KOW) conformed to the TLM for all endpoints with the exception of nitrification inhibition. Additional experimental data for the nitrification inhibition endpoint were generated for 16 narcotic chemicals using a procedure that allowed testing of volatile substances. Results obtained from the present study demonstrated that the nitrification inhibition endpoint was not adequately described by the TLM consistent with previous literature data. Acute to chronic ratios (ACRs) defined as the ratio of the EC50 to the 10% effect concentration (EC10) were available for two of the endpoints investigated and ranged from 1.1 to 2.3 for the Tetrahymena growth assay and from 2.4 to 24.1 for the nitrification inhibition endpoint. No inhibitory effects for any of the microbial endpoints investigated were observed for compounds with log(KOW) > 5. The critical target lipid body burdens (CL*) were calculated for the nine microbial toxicity endpoints conforming to the TLM and ranged from 252 to 2,250 μmol/g octanol. The Microtox® light inhibition (CL* = 252 μmol/g octanol) and Tetrahymena pyriformis growth (CL* = 254 μmol/g octanol) assays were found to be the most sensitive endpoints. The predicted no-effect concentration (PNEC) derived using the HC5 (hazardous concentration to 5% of test organisms) statistical extrapolation procedure was calculated using TLM parameters for substances with log(KOW) from 0 to 5. Results from this analysis demonstrate PNECs for narcotic compounds are protective of wastewater organisms excluding nitrifying bacteria. Further model improvement is needed if protection of nitrifying bacteria in wastewater treatment systems is required.
Effect of organic carbon content, clay type, and aging on the oral bioavailability of hexachlorobenzene in rats
Authors: Saghir Shakil A. , Bartels Michael J. , Budinsky Robert A. , Harris Jr., Eric E. , Clark Amy J. , Staley Jennifer L. , Chai Yunzhou , Davis John W.
Published: October 2007

Bioavailability of lipophilic chemicals is influenced by the physicochemical properties of soils/sediment such as particle size, pH, clay, and organic carbon content. The present study investigated the effects of sediment composition and aging on the oral bioavailability of hexachlorobenzene (HCB) in rats. Formulated sediments were prepared using various ratios of kaolinite and montmorillonite clay, sand, peat moss, and black carbon, spiked with 14C-HCB, and orally administered to rats prior to and after one year of aging in dark at 10°C. In the nonaged sediments there was a 21 to 45% reduction in the oral bioavailability of HCB when compared to the corn oil standard without any clear pattern of the impact of the sediment clay and/or organic carbon content. One year of aging resulted in statistically significant (p = 0.049) reduction in the oral bioavailability of HCB from the sediments compared to the corn oil standard and nonaged sediment indicating stronger interactions between HCB and sediment contents with aging. The mean reduction in oral bioavailability after one year of aging ranged from approximately 5 to 14% greater than that observed for nonaged sediments. The fecal elimination of the HCB-derived radioactivity from the one-year-aged sediments was much higher than the nonaged sediments, consistent with the lower absorption from the gastrointestinal tract due to lower desorption of HCB from the aged sediments. Increase in the fecal elimination and decrease in oral bioavailability of 14C-HCB was related to the increase in clay and black carbon.
Concentrations of methylated naphthalenes, anthracenes, and phenanthrenes occurring in Czech river sediments and their effects on toxic events associated with carcinogenesis in rat liver cell lines
Authors: Vondráĉek Jan , Ŝvihálková-Ŝindlerová Lenka , Pênĉíková Kater̂ina , Marvanová Son̂a , Krĉmár̂ Pavel , Ciganek Miroslav , Neĉa Jir̂í , Trosko James E. , Upham Brad , Kozubík Alois , Machala Miroslav
Published: October 2007

Alkylated polycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants. In the present study, we determined levels of monomethylated naphthalenes (MeNap), phenanthrenes (MePhe), and anthracenes (MeAnt) in Czech river sediments. The levels of MePhe generally were lower than the concentrations of phenanthrene. In contrast, both MeNap and MeAnt were found at levels higher than their respective parent compounds in the majority of sampling sites. We then investigated their aryl hydrocarbon receptor (AhR)-mediated activity, accumulation of phosphorylated p53 protein, induction of expression of cytochrome P450 1A1 (CYP1A1), inhibition of gap junctional intercellular communication (GJIC), and effects on cell proliferation in rat liver cell models to evaluate the relative importance of these toxicity mechanisms of low-molecular-weight methylated PAHs. Methylated phenanthrene and anthracene compounds were weak inducers of AhR-mediated activity as determined both in a reporter gene assay system and by detection of the endogenous gene (Cyp1a1) induction. 2-Methylphenanthrene was the most potent AhR ligand. Contribution of MeAnt and MePhe to overall AhR-inducing potencies should be taken into account in PAH-contaminated environments. Nevertheless, their effects on AhR were not sufficient to modulate cell proliferation in a normal rat liver progenitor cell model system. These PAHs only had a marginal effect on p53 phosphorylation at high doses of 1-, 3-, and 9-MePhe as well as 1 MeAnt. On the other hand, both 2- and 9-MeAnt as well as all the MePhe under study were efficient inhibitors of GJIC, suggesting that these compounds might act as tumor promoters. In summary, inhibition of GJIC and partial activation of AhR seem to be the most prominent toxic effects of the methylated PAHs in the present study.
Stereoisomeric separation and toxicity of the nematicide fosthiazate
Authors: Lin Kunde , Zhang Feng , Zhou Shanshan , Liu Weiping , Gan Jay , Pan Zhiyan
Published: October 2007

Considerable attention has been paid to the enantiomeric resolution and toxicity of some chiral organophosphorous pesticides (OPs) with one asymmetric center, but research concerning chiral OPs with two asymmetric centers is still limited. In the present study, the stereoisomeric separation and toxicity of fosthiazate, a chiral OP with two asymmetric centers on phosphorus and carbon atoms, was investigated. All four stereoisomers of fosthiazate were separated successfully with a Chiralpak® AD [amylase tris(3,5-dimethyl-phenyl carbamate)] column on high-performance liquid chromatography. The resolved isomers and the pairs of enantiomers were further distinguished using a circular dichroism detector and an optical rotation detector, designating the first (pk1) and third (pk3) eluted peaks as one pair of enantiomers and the second (pk2) and fourth (pk4) peaks as the other pair. The developed method was used to prepare microquantities of individual stereoisomers that were used for in vitro and in vivo bioassays. The inhibition potencies of the stereoisomers against acetylcholinesterase of Electrophorus electricus were slightly stereoselective, with a maximum difference of 1.4-fold among the isomers. A 3.1-fold difference, however, was observed in the acute toxicity of isomers to Daphnia magna. The 48-h toxicity of isomers to D. magna followed the order pk1 > pk2 > pk4 > racemate ≈ pk3. The stereoselective toxicity to D. magna found in fosthiazate suggests that the environmental safety of fosthiazate should be evaluated on the basis of its individual isomers.
Suitability of Cotton as an Alternative Crop in the Ogallala Aquifer Region
Authors: Gowda Prasanna H. , Baumhardt R. Louis , Esparza Allison M. , Marek Thomas H. , Howell Terry A.
Published: October 2007

Renewed interest in cotton (Gossypium hirsutum L.) production in the Ogallala Aquifer Region can be linked to development of early maturing varieties, rising energy costs, and declining water levels in the Ogallala Aquifer. The main objectives of this study were to assess the feasibility of growing cotton and estimate the cotton yield potential and the potential reduction in Ogallala Aquifer withdrawals by producing cotton as an alternative to corn. For this purpose, the heat unit based, county‐wide exceedance probability (P) curves for potential cotton yield were developed using a long‐term air temperature dataset (1971–2000), and counties that have the potential to produce cotton every year (P = 0.99), 4 out of 5 yr (P = 0.85), and 3 out of 4 yr (P = 0.75) return periods were identified and mapped. Results indicate that 91 of 131 counties in the study area have the potential to produce cotton with lint yield > 500 kg ha−1 3 out of 4 yr. A county‐wide lint yield goal based on a 3 out of 4 yr scenario may improve the chances for better profits to producers than with lint yield that can be expected every year. However, management uncertainties on water use efficiency; fuel, fertilizer, and pest management costs; and planting and harvesting schedule may require further consideration for estimating potential profitability. Nevertheless, these results show that cotton is a suitable alternative crop for most counties in southwest Kansas and all counties in the Texas and Oklahoma Panhandles. In addition, a significant reduction in water withdrawals from the Ogallala Aquifer for irrigation is probable if producers were to convert 50% of their land under corn to cotton production.
Yield Editor: Software for Removing Errors from Crop Yield Maps
Authors: Sudduth Kenneth A. , Drummond Scott T.
Published: October 2007

Yield maps are a key component of precision agriculture, due to their usefulness in both development and evaluation of precision management strategies. The value of these yield maps can be compromised by the fact that raw yield maps contain a variety of inherent errors. Researchers have reported that 10 to 50% of the observations in a given field contain significant errors and should be removed. Methods for removing these outliers from raw yield data have not been standardized, although many different filtering techniques have been suggested to address specific error types. We developed a software tool called Yield Editor to simplify the process of applying filtering techniques for yield data outlier detection and removal. Yield Editor includes a map view of the yield data, allowing the user to interactively set, assess the effects of, and refine a number of previously reported automated filtering methods. Additionally, Yield Editor allows manual selection of erroneous points, transects, or regions for investigation and possible deletion. This paper describes the filters implemented in Yield Editor, discusses input, output, and filtering options, and documents availability of the program. Example applications of Yield Editor on five test fields are used to show how the user interacts with the software and to analyze the relative importance of the various filters.
Thatch and Mat Management in an Established Creeping Bentgrass Golf Green
Authors: McCarty Lambert B. , Gregg Matthew F. , Toler Joe E.
Published: October 2007

Thatch is a layer of partially decomposed organic matter between green shoot tissue and the soil surface, and mat is thatch partially intermixed with topsoil. Excessive thatch–mat layering (>2.54 cm) is generally detrimental to turfgrass management, and numerous techniques including various mechanical and topdressing regimes, have been attempted to reduce its severity. This factorial experiment investigated the effectiveness of combining mechanical–biological and topdressing treatments for controlling thatch–mat levels in an established USGA‐specified golf green planted with ‘A‐1’ creeping bentgrass [Agrostis stoloniferous L. var. palustris (Huds.)]. Two levels of topdressing were used, and the mechanical–biological treatments included vertical mowing at two different depths and timings, core cultivation, grooming, a biological granular supplement (Thatch‐X), and combinations of core cultivation with grooming and/or vertical mowing. Differences among the mechanical–biological treatments were detected following 2 consecutive yearly applications. Thatch–mat depth (mm) was 12 to 15% greater for Thatch‐X and topdressing alone compared with other treatments. Organic matter content (g kg−1) increased 32% for the untreated and decreased 19% for core cultivation combined with vertical mowing and grooming, whereas all other treatments maintained pre‐study levels. Compared with the untreated, surface hardness was reduced ∼9% for all treatments using core cultivation, while water infiltration rates increased 127 to 168%. Vertical mowing treatments improved water infiltration rates by 40 to 65%. Turfgrass quality was not greatly impacted by the mechanical–biological treatments as ratings ranged from 8.4 to 10.0. However, mower scalping and dry spots contributed to unacceptable or only marginally acceptable turfgrass quality (6.4–7.2) for the untreated by the end of the study. Compared with topdressing alone, ball roll distance was decreased 6% by vertical mowing 7 days after treatment (DAT) and 5 to 8% by core cultivation up to 14 DAT. Sand topdressing alone was insufficient for managing thatch–mat levels in an established creeping bentgrass golf green.
Soil Seed Bank Composition in Pastures of Diverse Mixtures of Temperate Forages
Authors: Sanderson Matt A. , Goslee Sarah C. , Klement Keith D. , Soder Kathy J.
Published: October 2007

Seed banks may contribute useful or weedy species that fill gaps in pastures. In a previous study, pastures planted to complex mixtures of forages had a lesser proportion of weedy species in the aboveground vegetation. In this study, we relate changes in the species composition of the seed bank to changes in the aboveground vegetation. In August 2001, four mixtures [two, three, six, and nine species of temperategrasses, legumes and chicory (Cichorium intybus L.)] were established in replicated 1‐ha pastures (eight total) in central Pennsylvania. Pastures were grazed by dairy cattle from April to September in 2002 and 2003. Soil cores (1.88‐cm diam. by 5‐cm depth) were taken in April and October in 2002 and 2003, and in April 2004 to determine the density of germinable seeds. Soil samples were placed in a greenhouse under natural light and controlled temperatures for 12 to 18 mo and germinated seedlings counted regularly. The total density of germinable seeds from all species did not differ among mixtures (P = 0.08). Annual nonleguminous forbs accounted for 79% of the germinable seeds. Yellow woodsorrel (Oxalis stricta L.) was the dominant annual forb. There were significant differences among pastures planted to different mixtures in the density of germinable annual forb seeds; however, these differences likely occurred because of preexisting spatial variation in seed bank composition. Seeded species contributed fewer than 1000 seeds m−2 total in the 3 yr. Kentucky bluegrass (Poa pratensis L.) and white clover (Trifolium repens L.) were the most common forage species in the seed bank. There was little relation between the species composition of the seed bank and the composition of the aboveground vegetation. Data from this study indicate that previous land management had larger effects on the soil seed bank than did planting diverse mixtures of forages.
Cultivar Type, Plant Population, and Ascochyta Blight in Chickpea
Authors: Gan Yantai , Gossen Bruce D. , Li Lin , Ford Greg , Banniza Sabine
Published: October 2007

Integrated management strategies are required to minimize ascochyta blight, a fungal disease caused by Ascochyta rabiei (Pass.) Labrousse [teleomorph, Didymella rabiei (Kovachevski) v. Arx] in chickpea (Cicer arietinum L.). This study determined the effect of cultivars varying in plant architecture and plant population density (PPD) on the severity of ascochyta blight. Four desi chickpea (with pinnate leaves) and four kabuli chickpea (two with pinnate leaves and two with unifoliate leaves) were grown at 25, 36, 44, 53, and 62 plants m−2 (actual counts 3 wk after initial seedling emergence) at Swift Current from 2002 to 2005 and at Saskatoon in 2004 and 2005. Site‐years had a significant effect on ascochyta blight epidemics, with the highest severity at Swift Current in 2005 and lowest at Saskatoon in 2004. Across site‐years, ascochyta blight was most severe on ‘Evans’, followed by ‘CDC Xena’, and lowest on ‘222B‐11’. Cultivars with pinnate leaves had lower blight severity than those with unifoliate leaves during all growth stages. At the late‐pod stage, severity in cultivars with pinnate leaves averaged 15% compared with 48% in unifoliate cultivars. Kabuli cultivars had higher severity than desi cultivars throughout the growing season, and at the late‐pod stage, severity was 13% for the desi and 33% for the kabuli. There was a significant interaction between cultivar and PPD for blight severity. Ascochyta blight increased as PPD increased for the majority of the cultivars tested, with a few exceptions. Site‐year accounted for the largest portion of the treatment variance in blight severity (69%), followed by cultivar type (25%), and then PPD (6%). Increasing PPD consistently increased seed yield per unit area, despite more disease on plants at higher PPD. Identifying optimum plant populations for groups of cultivars with similar plant architecture should be a component in an integrated strategy to minimize ascochyta blight in chickpea.
Methane Oxidation in an Intensively Cropped Tropical Rice Field Soil under Long‐Term Application of Organic and Mineral Fertilizers
Authors: Nayak D. R. , Babu Y. Jagadeesh , Datta A. , Adhya T. K.
Published: October 2007

Methane (CH4) oxidation is the only known biological sink process for mitigating atmospheric and terrestrial emissions of CH4, a major greenhouse gas. Methane oxidation in an alluvial soil planted to rice (Oryza sativaL.) under long‐term application of organic (compost with a C/N ratio of 21.71), and mineral fertilizers was measured in a field‐cum‐laboratory incubation study. Oxidation rates were quantified in terms of decrease in the concentration of CH4in the headspace of incubation vessels and expressed as half‐life (t½) values. Methane oxidation rates significantly differed among the treatments and growth stages of the rice crop. Methane oxidation rates were high at the maximum tillering and maturity stages, whereas they were low at grain‐filling stage. Methane oxidation was low (t½= 15.76 d) when provided with low concentration of CH4On the contrary, high concentration of CH4resulted in faster oxidation (t½= 6.67 d), suggesting the predominance of “low affinity oxidation” in rice fields. Methane oxidation was stimulated following the application of mineral fertilizers or compost implicating nutrient limitation as one of the factors affecting the process. Combined application of compost and mineral fertilizer, however, inhibited CH4oxidation probably due to N immobilization by the added compost. The positive effect of mineral fertilizer on CH4oxidation rate was evident only at high CH4concentration (t½= 4.80 d), while at low CH4concentration their was considerable suppression (t½= 17.60 d). Further research may reveal that long‐term application of fertilizers, organic or inorganic, may not inhibit CH4oxidation.
Hydrological Variability and Agricultural Drainage Ditch Inorganic Nitrogen Reduction Capacity
Authors: Kröger R. , Holland M. M. , Moore M. T. , Cooper C. M.
Published: October 2007

The application of inorganic nitrogen fertilizers on agricultural landscapes has the potential to generate concerns of environmental degradation at fine to coarse scales across the catchment and landscape. Inorganic nitrogen species (NO3−, NO2−, and NH3) are typically associated with subsurface flow processes; however, surface runoff from rainfall events in no‐till agriculture with inorganic surface fertilizers might contribute to downstream eutrophication. Inorganic nitrogen reduction capacity of agricultural drainage ditches under no‐till cotton was determined under natural, variable rainfall conditions in northern Mississippi. Monthly grab baseflow samples and storm‐generated flow samples were variably sampled temporally within two experimental farm ditches over 2 yr. Inorganic nitrogen concentrations, in conjunction with Manning's equation and Natural Resources Conservation Service dimensionless hydrographs, provided individual water volumes per storm event and thus maximum effluent and outflow nitrogen loads. Base and stormflow regression results indicate drainage ditches reducing NO3− and NH3 over the length of the ditch for growing and dormant seasons. Overall, maximum storm loads of dissolved inorganic nitrogen (DIN) from the farm over the 2‐yr sampling period accounted for 2.2% of the initial fertilizer application, of which 1.1% left the ditch (0.84 kg ha−1 yr−1) (a 57% ditch reduction of DIN load over 2 yr). Long‐term sampling incorporating data on application and loss of fertilizers and farm management will provide critical information for farmers and scientists on the potential of economic gains and downstream ecosystem eutrophication, respectively.
Variations in Stream Water and Sediment Phosphorus among Select Ozark Catchments
Authors: Haggard Brian E. , Smith Douglas R. , Brye Kristofor R.
Published: October 2007

Stream sediments play a large role in the transport and fate of soluble reactive phosphorus (SRP) in stream ecosystems, and equilibrium P concentrations (EPC0) of benthic sediments at which P is neither adsorbed nor desorbed are often related to stream water SRP concentrations. This study evaluated (i) the variation among water chemistry and sediment‐P interactions among streams draining catchments that varied in the land use; (ii) the relations between SRP concentration, sediment EPC0, and other measured abiotic factors (e.g., particle size distribution, slope of linear sorption isotherms, etc.) in the stream sediments; and (iii) the use of the traditional Mehlich‐3 (M3) soil extraction on stream sediments to elucidate other abiotic factors (e.g, M3P, P saturation ratio, etc.) related to SRP concentration in stream sediments. Stream water and sediments were sampled at 22 selected Ozark streams in northwest Arkansas during fall 2003 and spring 2004. Nitrate‐N concentrations in the water column (r = 0.69) and modified P saturation ratios (PSRmod) of the benthic sediments (r = 0.79) at the selected streams increased with an increase in percent pasture in the catchments, whereas SRP concentration (r = –0.56) and Mehlich‐3–extractable P (M3P) content (r = –0.47) decreased with an increase in the percent forested area. Soluble reactive P concentrations in the stream water were positively correlated to sediment EPC0 (r = 0.51), although sediment EPC0 was generally greater than SRP. The M3 soil extraction was useful in identifying abiotic factors related to SRP concentrations in the selected streams, in particular SRP concentrations were positively correlated to M3P contents (r = 0.50) and PSRmod (r = 0.71) of the benthic sediments. Thus, M3P and EPC0 estimates from stream sediments may be valuable yet simple indicators of whether benthic sediments act as sinks or sources of P in fluvial systems, as well as estimating changes in stream SRP concentrations.