bluuebunny/crossref_metadata_2025 huggingface dataset:
Sorption of oxadiazon in soils cultivated in the brazilian cerrado
Authors: Mendes K.F. , Reis M.R. , Pereira A.A. , Nunes A.R.S. , Santos C.E.M. , Assis A.C.L.P.
Published: April 2014

The objective of this study was to evaluate oxadiazon sorption in different soils of the Brazilian Cerrado, highlighting the correlations of lethal doses of this herbicide capable of inhibiting 50% of the dry matter accumulation of the bio-indicator (LD50) among the chemical characteristics of the soil and its direct and indirect effects. The experiment was carried out in a greenhouse in a randomized block design and four repetitions. Each experimental unit consisted of a pot with increasing rates of oxadiazon and oat (Avena sativa), as the bio-indicator species. For sorption evaluation, washed sand and 22 soils (substrates) from Cerrado Brazilian's Alliaceae cultivated areas were used. LD50 and sorption ratio (SR) = [(LD50soil - LD50sand)/LD50sand] to the substrates were determined. Pearson correlation analysis was performed between the chemical characteristics of the substrates and the LD50 of oxadiazon. A path analysis was quantified, to deploy only the significant correlations estimated in direct and indirect effects of the characters on LD50, which is a basic variable. A more pronounced LD50 (528.09 g ha-1) for the Cerrado soil sample resulted in higher SR (> 53.00), while in the washed sand substrate, LD50 corresponded only to 9.74 g ha-1 of the oxadiazon (available in soil). It was concluded that oxadiazon sorption is influenced by the chemical characteristics of the soils, highlighting the correlation with pH (CaCl2), magnesium content, aluminum, organic matter, organic carbon, and aluminum saturation.
Formigas como bioindicadores da qualidade do solo em sistema integrado lavoura-pecuária
Authors: Crepaldi Rafael Aparecido , Portilho Irzo Isaac Rosa , Silvestre Rogério , Mercante Fábio Martins
Published: April 2014

O objetivo deste trabalho foi avaliar a comunidade de formigas em sistemas envolvendo a rotação entre lavoura e pecuária, sob plantio direto, comparado a outros sistemas de manejo e com sistemas naturais da região. O estudo foi conduzido no Município de Dourados, MS, sob Argissolo Vermelho distroférrico típico, num sistema integrado lavoura-pecuária, em plantio direto, rotacionado a cada dois anos. Outros sistemas de manejo avaliados, para comparação, incluíram o sistema convencional (aração e gradagem), sistema plantio direto e pastagem cultivada continuamente com Brachiaria decumbens, além de dois fragmentos de vegetação nativa, nos biomas Cerrado e Floresta Semidecídua. A coleta de solo foi realizada no período chuvoso (safra 2009/2010), sendo as amostragens de serapilheira realizadas com a utilização de extratores do tipo mini-Winkler, seguindo o protocolo ALL (Ants of the Leaf Litter). Os resultados indicaram morfoespécies de Strumygenys sp. e Hypoponera sp. como potencial bioindicadores de qualidade do solo. O estudo demonstrou que a importância da manutenção de fragmentos florestais (Cerrado e Floresta Semidecídua) e implementação de sistemas integrados, tais como lavoura-pecuária, são menos impactantes para a mesofauna de solo e contribuem para a conservação da diversidade de formigas e manutenção da qualidade do solo.
Variação longitudinal da massa específica básica da madeira de Cordia americana e Alchornea triplinervia
Authors: Trautenmüller Jonathan William , Balbinot Rafaelo , Borella Juliane , Trevisan Rômulo , Balestrin Diego , Vendruscolo Rafael , Sabadini Angélica Martinelli
Published: April 2014

A massa específica básica (MEb) é um dos principais parâmetros das propriedades da madeira. Considerando isso, este estudo teve por objetivo avaliar a variação longitudinal da MEb da madeira de Cordia americana (Linnaeus) Gottshling & J.E. Mill e de Alchornea triplinervia (Sprengel) Müller Argoviensis. As árvores foram selecionadas em um fragmento de Floresta Estacional Decidual Aluvial, em Iraí-RS, que, após o abate, foram medidas e cubadas pelo método de Smalian. Para a determinação da MEb, foram retirados discos nas posições da base, 25, 50, 75 e 100% da altura comercial e no diâmetro à altura do peito (DAP), 1,30 m do solo. Os resultados indicaram que a MEb da madeira de Alchornea triplinervia (S.) apresentou padrão homogêneo no sentido longitudinal do fuste; diferentemente da variação encontrada para Cordia americana (L.), em que os maiores valores dessa característica foram observados na base, com tendência decrescente até o topo das árvores.
Aclimatização de orquídea (Cymbidium sp.) em resposta à aplicação de ácidos húmicos
Authors: Baldotto Lílian Estrela Borges , Baldotto Marihus Altoé , Gontijo Júlia Brandão , Oliveira Fernanda Miranda de , Gonçalves Joelma
Published: April 2014

A aclimatização de mudas de orquídeas propagadas in vitro é um processo lento e que pode ser beneficiado com o uso de bioestimulantes, como, por exemplo, as substâncias húmicas. O presente trabalho objetivou estudar o crescimento de Cymbidium sp. em resposta à aplicação de ácidos húmicos extraídos de compostos orgânicos de cama de frango (AHcf) e de esterco bovino (AHeb) durante o período de aclimatização. As plantas micropropagadas foram imersas nas soluções de 0, 10, 20, 30 e 40mmol L-1 de C na forma de AHcf e de AHeb e aclimatizadas em viveiro. Aos 150 dias, as plantas foram coletadas para medição das variáveis: número de folhas, altura da planta, diâmetro do caule, matéria fresca da raiz e da parte aérea, matéria seca da raiz, da parte aérea e total, relação entre raiz:parte aérea. Os dados foram submetidos à análise de variância, contraste e análise de regressão. Os resultados mostraram incrementos no acúmulo de matéria seca total das plantas com a aplicação da concentração de 18,75mmol L-1 de C de AHcf e de 3,77mmol L-1 de C de AHeb, com incrementos em relação ao controle de 21 e 28%, respectivamente. Conclui-se que o uso dos ácidos húmicos nas doses indicadas acelera o crescimento das mudas propagadas in vitro de Cymbidium sp., favorecendo a diminuição do período necessário de aclimatização.
Antimicrobial susceptibility of Clostridium difficile isolated from animals and humans in Brazil
Authors: Silva Rodrigo Otávio Silveira , Oliveira Junior Carlos Augusto , Diniz Amanda Nádia , Alves Guilherme Guerra , Guedes Roberto Maurício Carvalho , Vilela Eduardo Garcia , Lobato Francisco Carlos Faria
Published: April 2014

The objective of this study was to evaluate antimicrobial susceptibility in Clostridium difficile strains isolated from animals and humans in Brazil. The 54 C. difficile strains used were isolated from stool samples from piglets (n=16), dogs (n=13), humans (n=13), foals (n=8) calves (n=2), an ocelot (n=1) and a maned wolf (n=1). Antimicrobial susceptibility was determined using the serial plate agar dilution method for penicillin, florfenicol, oxytetracycline, erythromycin, vancomycin, metronidazole and tylosin. The C. difficile strains assessed were susceptible to metronidazole and vancomycin. Florfenicol resistance was rarely observed; 52 (96.4%) strains were sensitive to this antimicrobial. Five (9.3%), five (9.3%), 14 (25.9%) and 20 (37.0%) strains were resistant to oxytetracycline, penicillin, tylosin and erythromycin respectively.
Resistência de Haemonchus placei, Cooperia punctata e Oesophagostomum radiatum à ivermectina pour-on a 500mcgkg-1 em rebanhos bovinos no Brasil
Authors: Lopes Welber Daniel Zanetti , Felippelli Gustavo , Teixeira Weslen Fabricio Pires , Cruz Breno Cayeiro , Maciel Willian Giquelin , Buzzulini Carolina , Matos Lucas Vinicius Shigaki de , Gomes Lucas Vinicius Costa , Pereira João Carlos Melo , Fávero Flávia Carolina , Oliveira Gilson Pereira de , Costa Alvimar José da
Published: April 2014

O amplo espectro de ação dos endectocidas e a praticidade de aplicação das suas formulações pour-on são fatores que têm estimulado uma maior frequência de utilização destes produtos na criação de bovinos. Neste estudo, avaliou-se a eficácia anti-helmíntica da ivermectina, administrada via pour-on, 500mcgkg-1, contra nematódeos de bovinos provenientes de diferentes rebanhos. Foram adquiridos 12 bezerros de cada um dos quatro rebanhos selecionados. Todos os 48 bezerros utilizados apresentavam médias de ovos por grama de fezes (OPG) maiores que 500, considerando-se três contagens consecutivas. Na sequencia, os animais de cada rebanho foram divididos em dois grupos de seis bovinos cada, sendo um tratado com ivermectina 500mcgkg-1 via pour-on e outro mantido como controle. Quatorze dias depois do tratamento, os bovinos foram submetidos à eutanásia para contagem de endoparasitas. A ivermectina demonstrou resultados nulos de eficácia contra H. placei nos quatro rebanhos. Contra C. punctata, tal formulação teve eficácia nula nos rebanhos provenientes de Jaboticabal,SP, e de Formiga,MG, e eficácias de 75,8% e 58,4% nos rebanhos provenientes de São José do Rio Pardo,SP, e de São Sebastião do Paraíso,MG, respectivamente. Valores de eficácia de 94,2% (Jaboticabal), 0,0% (São José do Rio Pardo), 94,2% (Formiga) e 39,2% (São Sebastião do Paraíso) foram detectados contra O. radiatum. Com base nos resultados encontrados, pode-se concluir que as quatro populações de Haemonchus placei e de Cooperia punctata avaliadas foram resistentes à ivermectina, administrada via pour-on, 500mcgkg-1. Foram observadas cepas de Oesophagostomum radiatum resistentes à ivermectina em dois dos quatro rebanhos testados.
Intoxicação crônica por Amaranthus spinosus em bovino no semiárido paraibano
Authors: Melo Diego Barreto de , Simões Sara Vilar Dantas , Dantas Antônio Flávio Medeiros , Galiza Glauco José Nogueira , Matos Rodrigo Antônio Torres , Medeiros Rosane Maria Trindade , Correa Franklin Riet
Published: April 2014

Descreve-se um caso de intoxicação por Amaranthus spinosus em bovino no estado da Paraíba, Brasil. Os principais sinais clínicos foram secreção nasal catarral, edema submandibular e de barbela e diarreia de odor fétido. Havia anemia, hipoproteinemia, hipoalbuminemia e concentrações séricas de ureia e creatinina aumentadas. Na necropsia, os rins estavam difusamente pálidos (superfícies natural e de corte) e levemente aumentados de volume. Histologicamente, observou-se nefrose tubular tóxica com acentuada regeneração epitelial tubular. O diagnóstico de intoxicação por A. spinosus deve ser incluído no diagnóstico diferencial da intoxicação por Combretum glaucocarpum (sin=Thiloa glaucocarpa) que, até o presente momento, era a única planta descrita como nefrotóxica na região Nordeste do Brasil.
Plantas tóxicas para ruminantes do Sudoeste de Goiás
Authors: Sant'Ana Fabiano José Ferreira de , Reis Junior Janildo Ludolf , Freitas Neto Argemiro Pereira , Moreira Junior Carlos Alberto , Vulcani Valcinir Aloisio Scalla , Rabelo Rogério Elias , Terra Juliano Pereira
Published: April 2014

Com o objetivo de verificar quais são as plantas incriminadas como tóxicas para ruminantes do Sudoeste de Goiás, foram realizadas 108 entrevistas com produtores rurais, médicos veterinários, zootecnistas e agrônomos de 18 municípios da região. Foram apontadas como tóxicas para ruminantes: Brachiaria spp., Enterolobium contortisiliquum, Dimorphandra mollis, Palicourea marcgravii, Pteridium aquilinum e Sorghum vulgare. Adicionalmente, foram informadas intoxicações menos frequentes por Senna occidentalis, Stryphnodendrum obovatum e Manihot esculenta. Casos isolados de intoxicação em bovinos por Asclepias curassavica e Pterodon emarginatus foram descritos por alguns entrevistados. Este trabalho demonstra que intoxicações por plantas tóxicas são frequentes na região avaliada e representam importante causa de prejuízos econômicos aos pecuaristas locais.
A sedação sobre os potenciais evocados auditivos em cães
Authors: Palumbo Mariana Isa Poci , Ramos Mariana Cristina , Outeda Nadia Crosignani , Resende Luiz Antonio de Lima , Pantoja José Carlos de Figueiredo , Borges Alexandre Secorun
Published: April 2014

O potencial evocado auditivo de tronco encefálico (Brainstem Auditory Evoked Potential - BAEP) avalia a atividade elétrica do sistema auditivo, desde a cóclea até o tronco encefálico, permitindo diagnóstico de surdez em cães. Como alguns animais não permitem a obtenção do BAEP sem contenção química, o objetivo deste trabalho foi analisar a influência da sedação com morfina e acepromazinano BAEP de 16 cães com audição normal. Os potenciais foram obtidos antes e durante a sedação com administração intramuscular de morfina (0,5mgkg-1) e acepromazina (0,05mgkg-1). O protocolo de sedação utilizado permitiu contenção efetiva e segurança dos animais. A sedação causou prolongamento nas latências das ondas II, III e intervalos I-III e I-V, mas não dificultou as suas identificações. O uso deste protocolo de sedação não interferiu com a interpretação do potencial evocado e pode ser útil em cães. Pelo que se pode observar na literatura compilada, este é o primeiro estudo avaliando a influência da sedação no BAEP em cães no Brasil.
Determinação do teor de umidade em grãos empregando radiação micro-ondas
Authors: Raschen Matheus Rafael , Lucion Fernanda Bortoluzzi , Cichoski Alexandre José , Menezes Cristiano Ragagnin de , Wagner Roger , Lopes Eduardo Jacob , Zepka Leila Queiroz , Barin Juliano Smanioto
Published: April 2014

A determinação de umidade em grãos é um parâmetro de qualidade importante, uma vez que o teor de água presente no alimento tem influência tanto no armazenamento quanto na comercialização do produto. Os métodos usados como referência na determinação de umidade em grãos empregam a perda por dessecação em estufa (LOD). Apesar de ser de fácil execução, esse método dispende cerca de 24h de aquecimento, normalmente, em 105°C, para obtenção do resultado. No presente estudo, é proposta a determinação da perda por dessecação assistida por radiação micro-ondas (MALOD) para amostras de grãos moídos de arroz branco, arroz integral, ervilha, feijão branco, feijão carioca, feijão preto, grão-de-bico, lentilha e milho, buscando reduzir o tempo de análise. Parâmetros como potência irradiada, massa de amostra, influência do recipiente e tempo de irradiação com micro-ondas foram avaliados e os resultados obtidos foram comparados com a LOD (sugerido pelo MAPA) e, também, por radiação infravermelha (IRLOD). Verificou-se que não houve diferença significativa do teor de umidade empregando massas de amostra entre 2 e 15g por LOD, porém, para MALOD, ocorreram hot spots (carbonização da amostra) com massas superiores a 2g. Resultados similares de umidade foram encontrados entre os diferentes recipientes (pesa-filtros e frascos de polipropileno), optando-se pela utilização dos frascos de polipropileno, devido à diminuição do tempo de pré-condicionamento. A MALOD apresentou concordância entre 94% e 102% com o método oficial, sendo que apenas 50min foram suficientes para determinar a umidade para todos os grãos, perfazendo uma redução do tempo de análise de até 29 vezes.
Macro and trace elements in edible mushrooms, Shiitake, Shimeji and Cardoncello from Petrópolis, Rio de Janeiro, Brazil
Authors: Gonçalves Jaylei Monteiro , Souza Monique Dias Corrêa de , Rocha Rafael Christian Chavez , Medeiros Renata Jurema , Jacob Silvana do Couto
Published: April 2014

The concentrations of twenty-five elements (Al, As, Ba, Bi, Ca, Cd, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb , Sb, Se, Sn, Sr, V and Zn) were determined in three edible mushrooms, Shiitake (Lentinula edodes), Black Shimeji (Pleurotus ostreatusi) and Cardoncello (Pleurotus eryngyii) from Petrópolis, Rio de Janeiro, Brazil. Samples were collected along the year 2010 and their preparations were made after drying, milling, an acid pre-digestion and a decomposition procedure in a muffle furnace. The analytical techniques employed for the elements determination were Mass Spectrometry with Inductively Coupled Plasma and Flame Atomic Absorption Spectrometry. Two certified reference materials, Apple Leaves and Mussel Tissue, were used for the evaluation of the analytical procedure and recovery values around 98% were obtained. The results showed that the analyzed mushrooms have high levels of Cu, Fe, K, Mg, Mn and Zn containing more than 30% the recommended daily intake for these nutrients according to Brazilian legislation. These mushrooms presented a very low ratio Na/K. Regarding the levels of some contaminants, the mushrooms had concentrations of Cd, Pb and As below the recommended maximum limits allowed by Brazilian legislation.
Minério de ferro, geologia econômica e redes de expertsentre Wisconsin e Minas Gerais, 1881-1914
Authors: Fischer Georg
Published: April 2014

O presente artigo trata da “descoberta” do minério de ferro brasileiro a partir de duas perspectivas. A primeira analisa a crescente ênfase das geociências em sua aplicação prática e em sua globalidade desde a segunda metade do século XIX. Enquanto no Brasil a geologia econômica foi integrada passo a passo às instituições do Estado, no nível global ela viveu momento de triunfo com o 11o Congresso Geológico Internacional, em 1910. A segunda trata de uma rede social específica com papel decisivo na corrida pelo minério de ferro brasileiro: experts transnacionais movimentandose entre as lógicas do mercado e as da academia. O artigo mostra a importância das negociações locais na incorporação do subsolo mineiro ao espaço global de mineração.
Numerical modeling of buckling failure in a mine slope
Authors: Silva Carolina Helena Caldeira , Lana Milene Sabino
Published: April 2014

In this work the failure mechanism of flexural buckling that occurred in Pau Branco Mine, of Vallourec & Mannesman Group, in 2002, was studied through the finite element method. The software Phase2, from Rocscience Inc. was employed in the analyses. Despite being a method applicable to continuous rock masses, discontinuities may be included in the model using joint elements. Modeling is simpler, avoiding the difficulties of using distinct element methods, due to the relative complexity of the geological section examined, where it was necessary to represent the variability of the foliation attitude, due to the pattern of the observed folds. The consideration of this variability was essential to reproduce buckling failure. Back analyses of failure mechanism were done, leading to representative values of the in situ stress state and the normal and shear stiffness modulus of the foliation discontinuities. The parameters generated by the analyses are extremely useful for further stability analyses in the phyllite slopes of Pau Branco Mine.
Projeto de lajes mistas nervuradas de concreto em incêndio
Authors: Pierin I. , Silva V. P.
Published: April 2014

As normas brasileiras de estruturas em situação de incêndio fornecem dimensões mínimas para as lajes nervuradas para assegurar as funções corta fogo e de estabilidade estrutural. Porém, uma nova laje mista nervurada lançada no mercado brasileiro não é coberta por qualquerdas normas brasileiras para a situação de incêndio. O objetivo deste trabalho é apresentar resultados inéditos, frutos de análises numéricastérmicas e estruturais para esse tipo de laje. Foram estudadas lajes com preenchimento de bloco de concreto celular, lajota cerâmica e EPSsuportado por placa cimentícia. O sistema construtivo é considerado como isolante térmico se possuir a capacidade de impedir a ocorrência,na face que não está exposta ao incêndio, de incrementos de temperatura maiores que 140 ºC na média dos pontos de medida ou maioresque 180 ºC em qualquer ponto de medida. A função estrutural foi determinada admitindo a limitação da temperatura das armaduras de vigas elajes em 500 ºC. As análises foram realizadas com auxílio dos programas ATERM e Super Tempcalc, programas computacionais para análisetérmica bidimensional de transferência de calor, por meio do método dos elementos finitos. Como resultado, serão apresentadas tabelas quecorrelacionarão o TRRF (tempo requerido de resistência ao fogo) às dimensões da laje e posição das armaduras. Antes do uso em projeto,esses resultados deverão ser confirmados por análise experimental.
Análise comparativa de soluções em fundações direta e sobre estacas para um equipamento industrial
Authors: Macabú L. P. , Santos S. H. C. , Lima S. S.
Published: April 2014

Apresenta-se uma metodologia para a análise de fundações de concreto armado em bloco rígido, submetidas a vibrações decorrentes da operação de máquinas. Esta análise é fundamental no projeto de grandes instalações industriais, em que estão presentes fundações paraequipamentos de grandes dimensões e custo elevado, e onde o comportamento estrutural adequado é essencial para a operação destas instalações. É apresentada inicialmente a metodologia de análise, baseada em dois programas computacionais, o BLOCKSOLVER e o PILAY. Esta metodologia é aplicada na análise comparativa de soluções em fundações diretas e sobre estacas de um soprador de gás, equipamento que integra os arranjos das refinarias petroquímicas. A análise dinâmica é feita para os dois tipos de fundação, fazendo também uma variação paramétrica do módulo de deformação transversal do solo (G). O dimensionamento da fundação é feito considerando o espaço limitado para a locação do equipamento determinado pelo arranjo da refinaria. Os resultados mais importantes são os deslocamentos máximos da fundação, que são verificados considerando as rigorosas limitações impostas pelas normas de projeto.
Vibrações devidas ao caminhar e às atividades aeróbicas: uma verificação teórica
Authors: Pretti L. A. , Ferreira W. G. , Calenzani A. F. G.
Published: April 2014

Este trabalho examina a verificação estrutural referente às vibrações em pisos de edifícios urbanos induzidas pelas atividades humanas quepossam motivar algum sentimento de desconforto aos usuários. Apresenta as recomendações normativas vigentes no país relativas ao conforto humano em estruturas na presença de vibrações induzidas pelo próprio usuário em suas atividades cotidianas tais como a prática docaminhar em ambientes residenciais ou comerciais e de atividades aeróbicas em ambientes diversos, como dançar, saltar e correr. Finaliza oferecendo informações relevantes e eminentemente práticas, possíveis de serem exercitadas manualmente ou com o mínimo de recursoscomputacionais pelos profissionais envolvidos, permitindo verificar na fase inicial de projeto a eventual necessidade de maiores cuidados nodimensionamento estrutural de pisos sujeitos as vibrações devidas às atividades humanas.
Assessing Species Boundaries and Sex-Associations in the GenusDrepanaporus(Hymenoptera: Pompilidae), With Comparison of the Utility of Cytochrome c Oxidase I and a Nuclear Molecular Marker, and the Description of a New Species ofDrepanaporus
Authors: Rodriguez Juanita , Dohlen Carol D Von , Pitts James P
Published: April 2014

The taxonomy of the Antillean genus Drepanaporus Bradley (Pompilidae) is problematic because of sexual dimorphism and nearly uniform morphology of males across species. Species limits are not well understood, and sexes are not properly associated in all species. In this study, we reassessed morphology, and collected novel molecular data for the purpose of determining species boundaries and establishing sex-associations for all species. Two genes, cytochrome c oxidase (COI) and long-wavelength rhodopsin (LWRh) were amplified for 20 specimens of Drepanaporus, from both females and males. Using LWRh (including both introns and exons) and COI sequences, the relationships of Drepanaporus samples were reconstructed. Sequences obtained for COI showed unusually high divergences and putative introgression, and thus were not used for taxonomic decisions. Taxonomic changes were made based on the LWRh phylogenetic results. A new species of Drepanaporus— Drepanaporus bachata sp. nov—is described herein based on both molecular and morphological characters for both male and female specimens, and a key is provided for the genus for the three species now recognized. We also discuss the usefulness of mitochondrial and nuclear markers in Pompilidae for species delimitations and sex-associations.
Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Increases Herbicide Use, Tillage, and Hand-Weeding in Georgia Cotton
Authors: Sosnoskie Lynn M. , Culpepper A. Stanley
Published: April 2014

In 2005, the existence of glyphosate-resistance in Palmer amaranth was confirmed at a single 250 ha field site in Macon County, Georgia. Currently, all cotton producing counties in Georgia are infested, to some degree, with glyphosate-resistant Palmer amaranth. In 2010 and 2011, surveys were administered to Georgia growers and extension agents to determine how the development of glyphosate-resistance has affected weed management in cotton. According to respondents, the numbers of cotton acres that were treated with paraquat, glufosinate and residual herbicides effective against Palmer amaranth more than doubled between 2000 to 2005 and 2006 to 2010. Glyphosate use declined between 2000 to 2005 and 2006 to 2010 although, on average, the active ingredient was still applied to a majority of cotton acres. Although grower herbicide input costs have more than doubled following the evolution and spread of glyphosate resistance, chemically-based control of Palmer amaranth is still not adequate. As a consequence, Georgia cotton growers hand weeded 52% of the crop at an average cost of $57 per hand-weeded ha; this represents a cost increase of at least 475% as compared to the years prior to resistance. In addition to increased herbicide use and hand weeding, growers in Georgia are also using mechanical, in-crop cultivation (44% of acres), tillage for the incorporation of preplant herbicides (20% of the acres), and post-harvest deep-turning (19% of the acres every three years) for weed control. Current weed management systems are more diverse, complex and expensive than those employed only a decade ago, but are effective at controlling glyphosate-resistant Palmer amaranth in glyphosate-resistant cotton. The success of these programs may be related to producers improved knowledge about herbicide resistance, and the biological attributes that make Palmer amaranth so challenging, as well as their ability to implement their management programs in a timely manner.
Crop Performance and Weed Suppression by Weed-Suppressive Rice Cultivars in Furrow- and Flood-Irrigated Systems under Reduced Herbicide Inputs
Authors: Gealy David R. , Anders Merle , Watkins Bradley , Duke Sara
Published: April 2014

Weed control in rice is challenging, particularly in light of increased resistance to herbicides in weed populations and diminishing availability of irrigation water. Certain indica rice cultivars can produce high yields and suppress weeds in conventional flood-irrigated, drill-seeded systems in the southern United States under reduced herbicide inputs, but their response to reduced irrigation inputs in these systems in not known. Rice productivity and weed control by weed-suppressive cultivars and conventional nonsuppressive cultivars were evaluated in a nonflooded furrow-irrigated (FU) system and a conventionally flooded (FL) system under three levels of weed management (herbicide inputs) in a 3-yr field study. Rice yields across all weed management levels yielded ∼ 76% less in the FU system than in the FL system. The allelopathic indica cultivar, ‘PI 312777’, and commercial hybrid rice ‘CLXL729’ generally produced the highest grain yields and greatest suppression of barnyardgrass in both irrigation systems. ‘Bengal’ and ‘Wells’ were the top-yielding conventional cultivars whereas ‘Lemont’ and ‘CL171AR’ yielded the least. Weed suppression by PI 312777 and CLXL729 under “medium” weed management was equivalent to that of Lemont and CL171AR at the “high” management level, suggesting that the weed-suppressive cultivars may be able to compensate for suboptimal herbicide inputs or incomplete weed control.
Inheritance of Glyphosate Resistance in Hairy Fleabane (Conyza bonariensis) from California
Authors: Okada Miki , Jasieniuk Marie
Published: April 2014

Inheritance of glyphosate resistance was investigated in hairy fleabane populations from California as part of providing the information needed to predict and manage resistance and to gain insight into resistance mechanism (or mechanisms) present in the populations. Three glyphosate-resistant individuals grown from seed collected from distinct sites near Fresno, CA, were crossed to individuals from the same susceptible population to create reciprocal F1populations. A single individual from each of the F1populations was used to create a backcross population with a susceptible maternal parent, and an F2population. Based on dose response analyses, reciprocal F1populations were not statistically different from each other, more similar to the resistant parent, and statistically different from the susceptible parent, consistent with nuclear control of the trait and dominance to incomplete dominance of resistance over susceptibility in all three crosses. Glyphosate resistance in two of the three crosses segregated in the backcross and the F2populations as a single-locus trait. In the remaining cross, the resistant parent had approximately half the resistance level as the other two resistant parents, and the segregation of glyphosate resistance in backcross and F2populations conformed to a two-locus model with resistance alleles acting additively and at least two copies of the allele required for expression of resistance. This two-locus model of the segregation of glyphosate resistance has not been reported previously. Variation in the pattern of inheritance and the level of resistance indicate that multiple resistance mechanisms may be present in hairy fleabane populations in California.
Evaluation of Weed Emergence Model AlertInf for Maize in Soybean
Authors: Masin Roberta , Loddo Donato , Gasparini Valentina , Otto Stefan , Zanin Giuseppe
Published: April 2014

AlertInf is a recently developed model to predict the daily emergence of three important weed species in maize cropped in northern Italy (common lambsquarters, johnsongrass, and velvetleaf). Its use can improve the effectiveness and sustainability of weed control, and there has been growing interest from farmers and advisors. However, there are two important limits to its use: the low number of weed species included and its applicability only to maize. Consequently, the aim of this study was to expand the AlertInf weed list and extend its use to soybean. The first objective was to add another two important weed species for spring-summer crops in Italy, barnyardgrass and large crabgrass. Given that maize and soybean have different canopy architectures that can influence the interrow microclimate, the second objective was to compare weed emergence in maize and soybean sown on the same date. The third objective was to evaluate if AlertInf was transferable to soybean without recalibration, thus saving time and money. Results showed that predictions made by AlertInf for all five species simulated in soybean were satisfactory, as shown by the high efficiency index (EF) values, and acceptable from a practical point of view. The fact that the algorithm used for estimating weed emergence in maize was also efficient for soybean, at least for crops grown in northeastern Italy with standard cultural practices, encourages further development of AlertInf and the spread of its use.
Predicting Emergence of 23 Summer Annual Weed Species
Authors: Werle Rodrigo , Sandell Lowell D. , Buhler Douglas D. , Hartzler Robert G. , Lindquist John L.
Published: April 2014

First- and second-year seedbank emergence of 23 summer annual weed species common to U.S. corn production systems was studied. Field experiments were conducted between 1996 and 1999 at the Iowa State University Johnson Farm in Story County, Iowa. In the fall of 1996 and again in 1997, 1,000 seeds for most species were planted in plastic crates. Seedling emergence was counted weekly for a 2-yr period following seed burial (starting in early spring). Soil temperature at 2 cm depth was estimated using soil temperature and moisture model software (STM2). The Weibull function was fit to cumulative emergence (%) on cumulative thermal time (TT), hydrothermal time (HTT), and day of year (DOY). To identify optimum base temperature (Tbase) and base matric potential (ψbase) for calculating TT or HTT, Tbaseand ψbasevalues ranging from 2 to 17 C and −33 to −1,500 kPa, respectively, were evaluated for each species. The search for the optimal model for each species was based on the Akaike's Information Criterion (AIC), whereas an extra penalty cost was added to HTT models. In general, fewer seedlings emerged during the first year of the first experimental run (approximately 18% across all species) than during the second experimental run (approximately 30%). However, second-year seedbank emergence was similar for both experimental runs (approximately 6%). Environmental effects may be the cause of differences in total seedling emergence among years. Based on the AIC criterion, for 17 species, the best fit of the model occurred using Tbaseranging from 2 to 15 C with four species also responding to ψbase= −750 kPa. For six species, a simple model using DOY resulted in the best fit. Adding penalty costs to AIC calculation allowed us to compare TT and HTT when both models behaved similarly. Using a constant Tbase, species were plotted and classified as early-, middle-, and late-emerging species, resulting in a practical tool for forecasting time of emergence. The results of this research provide robust information on the prediction of the time of summer annual weed emergence, which can be used to schedule weed and crop management.
Cover Crop Residues—Effects on Germination and Early Growth of Annual Weeds
Authors: Didon Ulla M. E. , Kolseth Anna-Karin , Widmark David , Persson Paula
Published: April 2014

There is an increasing interest in the use of cover crops in agriculture, in Sweden mainly for the use as catch crops to reduce nitrogen leakage. Some of these crops are known for their allelopathic abilities, which may play a role in the control of weeds and contribute to reduced herbicide use. This study aimed to explore the possible suppressive effect of the cover crop species white mustard, fodder radish, rye, and annual ryegrass on the early growth of the weed species silky windgrass, shepherd's-purse, and scentless false mayweed. In a greenhouse experiment using fresh cover crop residues, white mustard was the only crop that showed an effect. It reduced both seedling establishment, by 51 to 73%, and biomass, by 59 to 86%, of shepherd's-purse and scentless false mayweed. In contrast, in a growth chamber experiment using frozen material, mean germination time of silky windgrass was extended by 20 to 66% by all cover crops. Also, three out of four cover crops reduced root growth in scentless false mayweed by 40 to 46%, and two out of four cover crops reduced root growth in shepherd's-purse by 13 to 61%. However, considering seedling survival, white mustard was the most prominent cover crop, reducing survival by 21 to 57% in shepherd's-purse and scentless false mayweed. In this paper we provide evidence that different weed species show different response to different cover crops under climatic conditions prevailing in Scandinavia. Such results emphasize the importance of understanding weed–cover crop interactions as necessary for developing cropping systems that can utilize cover crops to suppress local weed flora.
In-Field Movement of Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) and Its Impact on Cotton Lint Yield: Evidence Supporting a Zero-Threshold Strategy
Authors: Norsworthy Jason K. , Griffith Griff , Griffin Terry , Bagavathiannan Muthukumar , Gbur Edward E.
Published: April 2014

This research was aimed at understanding how far and how fast glyphosate-resistant (GR) Palmer amaranth will spread in cotton and the consequences associated with allowing a single plant to escape control. Specifically, research was conducted to determine the collective impact of seed dispersal agents on the in-field expansion of GR Palmer amaranth, and any resulting yield reductions in an enhanced GR cotton system where glyphosate was solely used for weed control. Introduction of 20,000 GR Palmer amaranth seed into a 1-m2circle in February 2008 was used to represent survival through maturity of a single GR female Palmer amaranth escape from the 2007 growing season. The experiment was conducted in four different cotton fields (0.53 to 0.77 ha in size) with no history of Palmer amaranth infestation. In the subsequent year, Palmer amaranth was located as far as 114 m downslope, creating a separate patch. It is believed that rainwater dispersed the seeds from the original area of introduction. In less than 2 yr after introduction, GR Palmer amaranth expanded to the boundaries of all fields, infesting over 20% of the total field area. Spatial regression estimates indicated that no yield penalty was associated with Palmer amaranth density the first year after introduction, which is not surprising since only 0.56% of the field area was infested with GR Palmer amaranth in 2008. Lint yield reductions as high as 17 kg ha−1were observed 2 yr after the introduction (in 2009). Three years after the introduction (2010), Palmer amaranth infested 95 to 100% of the area in all fields, resulting in complete crop loss since it was impossible to harvest the crop. These results indicate that resistance management options such as a “zero-tolerance threshold” should be used in managing or mitigating the spread of GR Palmer amaranth. This research demonstrates the need for proactive resistance management.
An Ethnographic Study of Barriers to Cancer Pain Management and Opioid Availability in India
Authors: LeBaron Virginia , Beck Susan L. , Maurer Martha , Black Fraser , Palat Gayatri
Published: April 2014

Background.

The world's global cancer burden disproportionally affects lower income countries, where 80% of patients present with late-stage disease and have limited access to palliative care and effective pain-relieving medications, such as morphine. Consequently, millions die each year with unrelieved pain.

Objective.

The objective of this study was to examine barriers to opioid availability and cancer pain management in India, with an emphasis on the experiences of nurses, who are often the front-line providers of palliative care.

Methods.

Fifty-nine participants were recruited using a purposive, snowball sampling strategy. Ethnographic data collection included in-depth, semistructured interviews (n = 54), 400+ hours of participant observation, and review of documents over 9 months at a government cancer hospital in South India. Systematic qualitative analysis led to identification of key barriers that are exemplified by representative quotes.

Results.

Morphine is more available at this study site than in most of India, but access is limited to patients seen by the palliative care service, and significant gaps in supply still occur. Systems to measure and improve pain outcomes are largely absent. Key barriers related to pain management include the role of nursing, opioid misperceptions, bureaucratic hurdles, and sociocultural/infrastructure challenges.

Implications.

Interventions must streamline process details of morphine procurement, work within the existing sociocultural infrastructure to ensure opioids reach patients most in need, target unexpected audiences for symptom management education, and account for role expectations of health care providers.

Conclusion.

Macro- and micro-level policy and practice changes are needed to improve opioid availability and cancer pain management in India.
Are We Ready for the 10% Solution?
Authors: Chen Helen X. , Rubinstein Larry V. , Shankar Lalitha K. , Abrams Jeffrey S.
Published: April 2014

The limitations of the Response Evaluation Criteria in Solid Tumors (RECIST) for the assessment of molecularly targeted agents have been increasingly recognized with the advance of new therapies. The current study and others focusing on vascular endothelial growth factor-pathway inhibitors in advanced renal cell carcinoma highlight that tumor shrinkage below the RECIST threshold can be associated with significant clinical benefit, and flexibility in size change categorization should be considered in future modification of the criteria.
Calcium Phosphate Particles Induce Interleukin‐8 Expression in a Human Gingival Epithelial Cell Line via the Nuclear Factor‐κB Signaling Pathway
Authors: Sakai Yu , Nemoto Eiji , Kanaya Sousuke , Shimonishi Mitsuru , Shimauchi Hidetoshi
Published: April 2014

Background: Dental calculus is calcified plaque composed primarily of calcium phosphate mineral salts, and there is a clear association between the presence of calculus and the initiation/progression of periodontitis. However, it is still inconclusive whether dental calculus can be a direct causative factor. The authors examined the effect of nano/microsized calcium phosphate particles, which may be generated in the process of early precipitation and/or dissolution of calcium phosphate mineral, on the expression of interleukin (IL)‐8 in human gingival epithelial cells.

Methods: Primary human gingival epithelial cells and/or a human gingival carcinoma cell line (Ca9‐22) were stimulated with calcium phosphate particles. Gene and protein levels were assessed by real‐time polymerase chain reaction analysis and enzyme‐linked immunosorbent assay, respectively. The activity of nuclear factor (NF)‐κB signaling was measured by an immunofluorescence assay to evaluate NF‐κB p65 nuclear translocation.

Results: The results show that nano/microsized particles stimulate IL‐8 expression in human gingival epithelial cells at gene and protein levels. The activity to induce IL‐8 expression depends on the particle size: particles with a diameter of 200 nm are more effective than those of 40‐nm and 5‐μm diameters. Calcium phosphate particles (diameter 200 nm) stimulated NF‐κB activity. Pretreatment with BMS‐345541, an NF‐κB signaling inhibitor, inhibited the particle‐mediated IL‐8 gene induction, suggesting a requirement for the NF‐κB signaling pathway.

Conclusion: These findings suggest that calcium phosphate particles, which may be related to calculus development, may act as a direct causative factor in the pathogenesis of gingival epithelium.
Water and Nitrogen Management on Micronutrient Concentrations in Winter Wheat
Authors: Wang Shaoxia , Tian Xiaohong , Li Meng , Ni Yijun , Li Jin , Li Hongyun , Wang Shujuan , Chen Yanlong , Guo Chunhui , Zhao Aiqing
Published: April 2014

Water status and N fertility are the critical factors in micronutrient accumulation in grain of wheat (Triticum aestivum L.). This field experiment was conducted to examine whether the changes in N fertility and water management can influence micronutrient concentration and bioavailability in wheat grown in soils with existing low micronutrient concentrations within drought‐prone regions. The results indicate that fertilizer N (120 or 240 kg N ha−1) application significantly improved grain Zn, Fe, Cu, and protein concentration with a mean increase of 24.7, 39.2, 18.6, 23.9% in 2009/2010 and 8.9, 21.1, 10.5, 29.6% in 2010/2011, respectively, when compared with the unfertilized treatment. However, grain Mn concentration in both cropping seasons were significantly decreased (on average by 8.4%) by N fertilization. Compared to the no irrigation treatment (NI), the water‐saving treatment (RF) significantly increased grain Zn by an average of 13.2%, grain Fe by 22.2%, grain Mn by 4.4%, and grain protein by 8.3%. Grain phytic acid (PA) concentration and PA/micronutrient ratios were on average 28.0 and 32.2% lower in the N fertilized treatment than in the unfertilized treatment. Decreasing the N application rate from 240 to 120 kg N ha−1 did not affect much of the grain nutritional quality, with the exception of a significant decrease in grain Zn concentration, and a significant increase in grain PA concentrations and the PA/Zn molar ratio. These data demonstrate the importance of monitoring grain Zn concentrations, and perhaps the inclusion of supplemental Zn when adopting alternative N fertilizer management regimes in northern China.
Dithiopyr Efficacy, Absorption, and Fate in Annual Bluegrass, Goosegrass, Smooth Crabgrass, and Tall Fescue
Authors: Gómez de Barreda Diego , Sidhu Sudeep S. , Yu Jialin , Reed Thomas V. , McCullough Patrick E.
Published: April 2014

Dithiopyr provides pre‐ and early postemergence (POST) control of smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl] in tall fescue (Festuca arundinacea Schreb.), and may allow greater application flexibility in spring than other herbicides. Dithiopyr also provides preemergence (PRE) control of annual bluegrass (Poa annua L.) and goosegrass [Eleusine indica (L.) Gaertn.], but POST applications are ineffective and may result from differential physiological fate compared to smooth crabgrass. Experiments were conducted to investigate efficacy, absorption, distribution, and metabolism of dithiopyr in annual bluegrass, goosegrass, smooth crabgrass, and tall fescue. From seven dithiopyr rates, 1.18, 1.03, 0.76, and >4.48 kg a.i. ha−1 were required to reduce shoot mass 50% from the nontreated for annual bluegrass, goosegrass, smooth crabgrass, and tall fescue, respectively. In laboratory experiments, smooth crabgrass had ≈75% more kBq kg−1 following root absorption of 14C‐dithiopyr than annual bluegrass, goosegrass, and tall fescue after 72 h. All species recovered >90% of foliar‐absorbed 14C in the treated leaf after 72 h, with limited 14C recovery (≤5%) in roots and nontreated shoots. Metabolism of dithiopyr increased from 1 to 7 d after treatment (DAT) in all grasses. Final metabolism measured 69, 52, 33, and 27% of total 14C recovered in smooth crabgrass, goosegrass, annual bluegrass, and tall fescue, respectively. Results suggest relative herbicide concentration and greater metabolism is associated with dithiopyr selectivity for POST control of smooth crabgrass compared to other grassy weeds in turf.
Winter Wheat Response to Planting Date under Dryland Conditions
Authors: Nleya Thandiwe , Rickertsen John R.
Published: April 2014

Planting date is an important management tool that influences winter wheat (Triticum aestivum L.) performance in the Northern Great Plains. A study was conducted to: (i) evaluate the effect of planting date on grain yield and agronomic traits of eight winter wheat cultivars varying in season length and winter hardiness; and (ii) determine if any interaction between cultivar and planting date exists. The study was located near Wall (43.99° N, 102.24° W) in western South Dakota from 2005 through 2007. Winter wheat cultivars were planted at five planting dates ranging from mid‐September to early December. The response of winter wheat grain yield to planting date was quadratic, with the optimum planting date for maximum yield varying among winter wheat cultivars. Optimum planting dates for early and medium maturing cultivars ranged from 7 September to 19 October. For the late maturing cultivar, optimum planting dates ranged from 5 to 20 October, narrower than the current recommendations. The grain yields for early, medium, and late maturing cultivars were similar at early and intermediate planting dates, suggesting that in early planting situations, the season length of the winter wheat cultivar is not an important determinant of yield. The late maturing cultivar yielded lower than early or medium maturing cultivars when planting was delayed to dates later than mid‐October in all 3 yr. Yield reduction with delayed planting was mostly due to a reduction in head density. Kernels per head increased with delayed planting but the increase was not enough to compensate for low tiller production in late‐planted wheat.