bluuebunny/crossref_metadata_2025 huggingface dataset:
A pesquisa de intervenção na psicologia da educação matemática: aspectos conceituais e metodológicos
Authors: Fávero Maria Helena
Published: September 2011

Focamos um dos grandes desafios atuais da psicologia: a pesquisa de intervenção tomada como geradora de transformação e que, ao mesmo tempo, evidencia o processo a ela subjacente. Expomos nossa linha teórico-metodológica de investigação e relatamos uma pesquisa de intervenção no contexto da psicologia da educação matemática. Consideramos quatro aspectos teórico-conceituais articulados: 1. a evidência das interações entre as regulações cognitivas e as sociais; 2. o papel da mediação semiótica no desenvolvimento psicológico humano; 3. os efeitos dos sistemas de signos no desenvolvimento psicológico e nas comunicações individuais; 4. a tomada de consciência de que as ações humanas não são aleatórias: trata-se de práticas sociais com um conteúdo que lhes dão fundamento. Tais aspectos fundamentam a Psicologia do conhecimento e o método adotado, com um duplo desafio: desenvolver um procedimento visando à tomada de consciência de uma professora licenciada em matemática sobre o paradigma que sustentava sua prática e o reformulasse assumindo um trabalho sistematizado de articulação entre intervenção psicopedagógica e pesquisa, que possibilitasse: 1. o estudo das aquisições conceituais dos alunos; e 2. a análise dos processos mediacionais das interações interpessoais, considerando a natureza do material utilizado e das atividades propostas. Os resultados evidenciaram a pertinência do procedimento: as atividades propostas e a qualidade da atividade mediada engendraram a aquisição de novas competências conceituais nos alunos e o desenvolvimento de novas competências para a professora como mediadora do conhecimento.
Estudo de intervenção sobre a divisão: ilustrando as relações entre metacognição e aprendizagem
Authors: Lautert Síntria Labres , Spinillo Alina Galvão
Published: September 2011

Discute-se um estudo de intervenção conduzido em um contexto experimental em que a interação adulto-criança era marcada por atividades metacognitivas com vistas a auxiliar na superação das dificuldades experimentadas por crianças com o conceito de divisão. As atividades metacognitivas propostas envolviam a tomada de consciência da criança sobre procedimentos adotados na resolução de problemas, sendo associada uma explicitação dos princípios invariantes do conceito de divisão. O estudo consistiu em um pré-teste e um pós-teste aplicado a 100 crianças de baixa renda (8 a 11 anos), alunas do 4.º ano do ensino fundamental de escolas públicas na cidade do Recife que apresentavam dificuldades com a divisão. As crianças foram distribuídas em um grupo controle e em um grupo experimental, havendo as crianças do grupo experimental participado da referida intervenção. As relações entre metacognição e aprendizagem são ilustradas a partir da apresentação e discussão de passagens extraídas das sessões de intervenção. Os resultados mostraram que no pré-teste os dois grupos não diferiam entre si, apresentando o mesmo nível de dificuldade; porém, após a intervenção, os participantes do grupo experimental superaram as dificuldades iniciais, o mesmo não sendo observado em relação aos participantes do grupo controle.
Pesquisas atuais sobre a construção do conceito de número: para além de Piaget?
Authors: Nogueira Clélia Maria Ignatius
Published: September 2011

As atuais pesquisas acerca da construção do número vêm resgatando o papel desempenhado pelas atividades numéricas (em particular, a contagem) na construção do número. Para a maioria dos autores dessas pesquisas e outros estudiosos do tema, os resultados mais recentes, quando não contrariam, ultrapassam, do ponto de vista teórico, o estágio alcançado pelas pesquisas do Centro Internacional de Epistemologia Genética. Neste trabalho discutimos o papel da contagem no desenvolvimento do número segundo a Epistemologia Genética. Buscando destacar a atualidade da teoria piagetiana, comentamos algumas das recentes pesquisas e propostas metodológicas sobre a construção do conceito de número que se fundamentam quase que exclusivamente na contagem, procurando verificar se os resultados encontrados ou as sugestões apresentadas pelos pesquisadores estariam, do ponto de vista teórico, "além de Piaget".
Influência de diferentes sistemas de manejo e calagem em experimento de longa duração sobre fungos micorrízicos arbusculares
Authors: Schneider Jerusa , Klauberg Filho Osmar , Fontoura Sandra Mara Vieira , Alves Mauricio Vicente
Published: September 2011

Visando estudar a influência de diferentes sistemas de manejo do solo com e sem calagem, sobre a colonização micorrízica radicular e a produção de micélio extrarradicular, por meio de técnica de análise multivariada, utilizou-se um experimento implantado em 1978, no município de Guarapuava, PR. A análise de componentes principais comprovou a existência de efeitos negativos do sistema de preparo convencional do solo sobre a colonização de fungos micorrízicos arbusculares (FMAs) do solo, principalmente em estruturas como arbúsculos e vesículas. A calagem apresentou benefícios para os parâmetros de colonização micorrízica e comprimento de micélio extrarradicular, sendo mais significativo nos sistemas de manejo conservacionistas, principalmente o sistema de plantio direto. Nas áreas de sistemas convencionais ocorreu uma redução na colonização micorrízica e, conseqüentemente, diminuição dos efeitos benéficos dos FMAs para as plantas, reduzindo a qualidade do solo e a sustentabilidade.
Evaluation of omega-3 fatty acids content and antioxidant activity in wheat (Triticum aestivum L.) leaves
Authors: Aguiar Ana Carolina de , Boroski Marcela , Bonafé Elton Gutendorfer , Almeida Vanessa Vivian de , Souza Nilson Evelázio de , Visentainer Jesuí Vergílio
Published: September 2011

The objective of this study was to quantify alpha-linolenic acid (LNA, 18:3n-3) of dried wheat leaves, harvested at different development stages (20, 40 and 80 days), to determine the antioxidant potential and the total phenolic compounds of leaves harvested at 80 days, as well as to perform mineral analysis (Na, K, Fe, Ca, Mg, P, Zn, Cu and Mn). It was observed a predominance of polyunsaturated fatty acids (PUFA) compared to saturated fatty acids (SFA) in the lipid fraction of leaves. Leaves collected in all periods presented ratios of PUFA/SFA, omega-6 and omega-3 fatty acids (n-6/n-3) considered suitable for food. The highest content of LNA was found in leaves harvested at 60 days, corresponding to 2.146,72 mg 100 g-1 dried matter. The range time between 60 and 80 days showed a decline of nearly 30% in the concentration of LNA. The acetate fraction was the most effective over DPPH radical assay, showing IC50 value of 154 µg mL-1, and the phenolic compounds content was 615.4 ± 36.4 mg EAG L-1, both analyses carried out in leaves harvested at 80 days. In this development stage, wheat leaves showed significant levels of the minerals P, Zn, Cu and Mn. These results reinforce the potential of using wheat leaves in foods, according to its antioxidant content and significant levels of LNA.
Viabilidade econômica da terminação de novilhos Nelore e Red Norte em confinamento na região de Lavras-MG
Authors: Lopes Leandro Sâmia , Ladeira Márcio Machado , Machado Neto Otávio Rodrigues , Silveira Antonio Rogério Mendes Carli da , Reis Ricardo Pereira , Campos Fabrício Rodrigues
Published: September 2011

Conduziu-se este trabalho, com o objetivo de verificar a viabilidade econômica da terminação em confinamento de novilhos Nelore e Red Norte na região de Lavras, MG. Foram utilizados 41 novilhos, não castrados, de dois grupos genéticos, sendo: 19 Nelore e 22 Red Norte, com pesos vivos iniciais médios de 315 ±31 kg e 321 ±30 kg, respectivamente. O período experimental foi de 112 dias, divididos em quatro períodos de 28 dias. A viabilidade econômica foi analisada utilizando o modelo de custo, considerando os custos operacionais, alternativos e de depreciação. Todos os indicadores econômicos gerados apresentaram resultados negativos. A atividade apresentou prejuízo de R$ 6,88 e 19,74/arroba para os animais Red Norte e Nelore, respectivamente. Os resultados negativos obtidos nessas condições ocorreram porque o custo operacional efetivo foi maior que o preço de venda da arroba. Em um cenário com a aquisição de animais a atividade de confinamento apresentou resíduo próximo de zero para o grupo Red Norte. A prática do confinamento não apresentou viabilidade econômica para a região de Lavras, MG, no ano de 2007.
Viabilidade econômica do uso do sistema de irrigação por gotejamento na cultura da cebola
Authors: Boas Renato Carvalho Vilas , Pereira Geraldo Magela , Reis Ricardo Pereira , Lima Junior Joaquim Alves de , Consoni Rodrigo
Published: September 2011

Objetivou-se, com este estudo, avaliar a viabilidade econômica do uso do sistema de irrigação por gotejamento na cultura da cebola. O experimento foi conduzido em canteiros construídos a céu aberto, na área experimental do Departamento de Agricultura/ UFLA, no período de junho a outubro de 2008. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial 2 x 6, com quatro repetições. Os tratamentos constituíram-se de duas cultivares de cebola, cultivar híbrida Optima F1 e cultivar não híbrida Alfa Tropical, e seis tensões da água no solo, 15, 25, 35, 45, 60 e 75 kPa. A análise econômica da lavoura irrigada foi fundamentada na teoria dos custos de produção e, considerando-se a metodologia aplicada, conclui-se que as despesas com os recursos variáveis foram as que mais oneraram o custo final da cebola em todos os tratamentos estudados. Os custos totais médios foram, inversamente, proporcionais às produtividades dos tratamentos de tensão da água no solo, para ambas as cultivares, indicando uma resposta à escala de produção. Na condição do experimento, a recomendação é de que se adote, como momento de irrigar, a tensão da água no solo de 15 kPa e, como cultivar o híbrido Optima F1, para que se obtenha maior rentabilidade na atividade produtiva. A irrigação por gotejamento na cultura da cebola, adotando-se as tensões da água no solo e as cultivares estudadas neste trabalho, é uma técnica economicamente viável.
Estudo de rajadas de ventos e direções predominantes em Lavras, Minas Gerais, por meio da distribuição gama
Authors: Bueno Renato Cândido , Carvalho Luiz Gonsaga de , Vianello Rubens Leite , Marques João José Granate de Sá e Melo
Published: September 2011

O presente trabalho foi conduzido com o objetivo de estudar as probabilidades de ocorrência de ventos extremos e suas direções predominantes para a região de Lavras, MG. Foram usados os dados registrados pelo anemógrafo universal da Estação Climatológica Principal de Lavras, situada no campus da Universidade Federal de Lavras. Com os dados disponíveis (139 meses), no período de janeiro de 1988 a maio de 2004, verificou-se o ajuste à distribuição Gama pelo teste de χ² a 5% de probabilidade. Foram estimadas probabilidades de ocorrência de velocidades máximas diárias de vento iguais ou superiores a 10, 20, 30, 40, 50, 60, 70, 80, 90 e 100 km h-1, para cada mês. Verificou-se que os meses de setembro a fevereiro apresentaram ventos fortes, com probabilidades de ocorrência superiores as dos outros meses. Para ventos bastante fortes acima de 100 km h-1, as probabilidades de ocorrência são mínimas para todos os meses do ano. Quanto à direção para as rajadas de ventos, observou-se predominância das direções leste e oeste em relação às demais.
Perfil da aptidão física dos praticantes de Le Parkour
Authors: Leite Neiva , Aguiar Junior Rossine Pinto de , Cieslak Fabrício , Ishiyama Mary , Milano Gerusa Eisfeld , Stefanello Joice Mara Facco
Published: September 2011

O objetivo deste estudo foi avaliar a aptidão física dos praticantes do Le Parkour na cidade de Curitiba-PR. Participaram do estudo 13 sujeitos (19,46 ± 2,82 anos) do sexo masculino, praticantes da atividade há mais de seis meses. Foram realizadas medidas antropométricas e testes de aptidão física (teste de corrida vai-e-vem de 20 metros, de abdominal em um minuto, flexão e extensão dos braços, impulsão vertical e horizontal, sentar-e-alcançar e teste de Wingate). Os resultados foram analisados através de estatística descritiva (média e desvio padrão), sendo classificados com base em tabelas de referência para cada teste. Após avaliar o VO2máx, 53,85% dos praticantes estavam com valores considerados "baixa aptidão" e 46,15% apresentaram uma aptidão cardiorrespiratória adequada. Na força/resistência abdominal, 46,15% dos sujeitos foram classificados como "baixa aptidão" e 53,85% como "faixa recomendável". A potência de pico e a potência média foram consideradas como "regular" em todos os indivíduos. O índice de fadiga foi igual ou superior em 54% dos sujeitos. A flexibilidade foi avaliada como "baixa aptidão" em 69,23% da amostra. Na avaliação da força/resistência de membros superiores, observou-se que 84,62% estavam na "faixa recomendável". A partir dos resultados encontrados neste estudo, sugere-se que o Le Parkour, por ser uma atividade acíclica com ênfase em saltos e atividades de força nos braços, ocasionou melhores valores nos testes de impulsão horizontal, vertical e força de membros superiores. Entretanto, as demais variáveis avaliadas estavam abaixo da média, o que deve ser considerado na prescrição de exercícios e no acompanhamento dos indivíduos durante a prática da atividade. Sugerem-se novos estudos com amostras maiores e controle de treinamento dos praticantes de Le Parkour.
An overview of the epidemiology of periodontal diseases in Latin America
Authors: Oppermann Rui Vicente
Published: September 2011

The aim of the present review was to identify the presence of periodontal diseases and the relative importance of known risk factors in Latin American countries. The retrieved data are sparse and inconsistent, lacking information for the majority of the countries. Gingivitis is ubiquitous in the region, affecting all ages independently of the socioeconomic background. The extension of bleeding may vary greatly, ranging from 40% to 70% of sites. The prevalence of aggressive periodontitis is higher in Latin America than in industrialized countries. Prevalence ranges from 0.3% to 4.5%, and the localized form is the less prevalent. The prevalence of chronic periodontitis is high, with a large variation (40-80%) probably due to differences in methodology and diagnostic criteria. Regional differences may be relevant. Known risk factors are present in the populations studied. Non-modifiable factors such as age, gender and genetics have been associated in Brazilian and Chilean populations. Tobacco smoking and diabetes are relevant risk factors. The importance of socioeconomic status, although present as a risk factor, has been largely underestimated. Oral hygiene is extremely deficient in the area although it is a cultural habit in most populations. It can be concluded that periodontal diseases are highly prevalent in Latin American populations. Its prevalence and extent are associated with known risk factors. Oral hygiene habits are deficient. Well designed epidemiological studies with external validity are needed.
Evaluating Restoration Methods across a Range of Plant Communities Dominated by Invasive Annual Grasses to Native Perennial Grasses
Authors: Nyamai Priscilla A. , Prather Timothy S. , Wallace John M.
Published: September 2011

Prairies are imperiled habitats, with remnants being generally small and often existing in isolation. Invasive plants have the potential to invade not just the edge of small remnants but also the interior because smaller remnants experience greater edge effects than do large, contiguous prairies. Additionally, invasive plants limit recruitment of native plants, which can arrest secondary succession. We proposed to assess techniques for restoration that included removing annual grasses and supplementing native species recruitment with seeding of native grass and forb species. We also assessed the effect of specific factors affecting recruitment: soil moisture and seed predation. Treatments included broadcast, spot, or no application of the herbicides imazapic and glyphosate and with or without seeding plus mulch. With treatments nested within each of three plant communities, ranging from annual- to perennial-dominated communities, in four blocks per community, plant characteristics (percentage of cover and plant density), soil moisture availability, and seed-predation losses were measured along a plant community gradient within one season at two locations. A combination of broadcast herbicide application and seeding with mulching was found to be more effective in reducing annual grasses and enhancing the establishment of native grass species in predominately annual and mixed communities (annuals and perennials). Spot herbicide application was effective in predominately perennial communities, whereas only seeding native species did not improve recruitment. Although seed predation reduced seedling recruitment, mulch provided seed protection and enhanced soil moisture retention. Plant community response to imposed treatments differed among communities, suggesting that a decision support tool would facilitate management decisions tailored for each plant community. The decision tool would be useful to ensure that appropriate treatments are applied and that specific factors affecting recruitment, such as seed predation and soil moisture, are addressed.
Using Rangeland Health Assessment to Inform Successional Management
Authors: Sheley Roger L. , James Jeremy J. , Vasquez Edward A. , Svejcar Tony J.
Published: September 2011

Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in a favorable direction. The objective of this paper is to detail how these two endeavors can be integrated to form a holistic vegetation management framework. The Rangeland Health Assessment procedures described by Pyke et al. (2002) and Pellant et al. (2005) currently are being adopted by land managers across the western United States. Seventeen standard indicators were selected to represent various ecological aspects of ecosystem health. Each of the indicators is rated from extreme to no (slight) departure from the Ecological Site Description and/or the Reference Area(s). Successional management identifies three general drivers of plant community change: site availability, species availability, and species performance, as well as specific ecological processes influencing these drivers. In this paper, we propose and provide examples of a method to link the information collected in rangeland health assessment to the successional management framework. Thus, this method not only allows managers to quantify a point-in-time indication of rangeland health but also allows managers to use this information to decide how various management options might influence vegetation trajectories. We argue that integrating the Rangeland Health Assessment with Successional Management enhances the usefulness of both systems and provides synergistic value to the decision-making process.
The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes
Authors: Pino Nicola Alessandro
Published: September 2011

Seismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100–120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques.

In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the XXth century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) – both of which are the strongest ever recorded instrumentally in their respective countries –and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismogenic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Apennines.
Row Spacing and Nitrogen Effects on Upright Pinto Bean Cultivars under Direct Harvest Conditions
Authors: Eckert Fernando R. , Kandel Herman J. , Johnson Burton L. , Rojas‐Cifuentes Gonzalo A. , Deplazes Chad , Vander Wal Albert J. , Osorno Juan M.
Published: September 2011

Increasing soil‐N in a dry bean (Phaseolus vulgaris L.) crop may increase seed yield. However, excessive N can inhibit nodule formation, delay maturity, and promote vegetative growth. In the same way, the effect of row spacing on yield and other traits appears to be different for variable levels of available N. With releases of new upright pinto bean cultivars, it is unknown how factors such as row spacing and soil‐N level may affect seed yield and seed losses under direct harvest operations. Experiments were conducted in North Dakota to evaluate the effect of row spacing and soil‐N level on agronomic traits of pinto bean cultivars under direct harvest. The experimental design was a randomized complete block design in a split‐plot arrangement, where whole plots were three row spacings (30, 46, and 76 cm), and subplots were a factorial with three pinto cultivars (Lariat, Stampede, and Maverick) and two soil‐N levels (56 and 112 kg N ha−1). Cultivar and row spacing were the most important factors determining seed yield and seed loss. Lariat produced the greatest seed yield (2045 kg ha−1) and had the lowest harvest loss (11.6%). The intermediate row spacing (46 cm) had the highest seed yield with no significant changes in the amount of seed loss when compared with the wide rows (76 cm). The N level did not influence seed yield or yield potential. Therefore, to maximize productivity with upright pinto cultivars, growers should plant at intermediate row spacing and reduce the amount of N applied.
Utilization of Dry Distillers Grains and Charcoal as Nitrogen Fertilizer in Corn
Authors: Shroyer K. J. , Staggenborg S. A. , Propheter J. L.
Published: September 2011

Increasing bioenergy production will result in increased by‐products which will need proper disposal methods to prevent economic and/or ecological problems. Land application has potential for disposal and/or nutrient cycling if these by‐products have crop nutritive value. Our objective was to compare the fertilizer effects of two by‐products of bioenergy production, dry distillers grains with solubles (DDGs) and charcoal with urea in corn (Zea mays L.) and evaluate nutrient uptake. Treatments were DDGs under no‐till and tilled at four location‐years and charcoal under no‐till and tilled at three location‐years. No‐till urea was used as a baseline at all location‐years. Nitrogen rates ranged from 0 to 180 kg N ha−1. All materials were spring applied before tillage and planting. Corn yields for DDGs and urea were similar across tillage treatments and locations. Corn yields over all charcoal rates and tillage treatments were the same as 0 kg N ha−1. The charcoal, because of immobilization or lack of decomposition, did not contribute to the corn N nutrition. Neither material showed any negative effects on the corn yields. Stalk N, P, K, and grain N followed expected trends and had few effects compared with those from urea. Land application of DDGs and charcoal has merit for disposal/N cycling with DDGs being preferred for its N contribution.
Yield Gaps, Indigenous Nutrient Supply, and Nutrient Use Efficiency of Wheat in China
Authors: Liu Xiaoyan , He Ping , Jin Jiyun , Zhou Wei , Sulewski Gavin , Phillips Steve
Published: September 2011

Great advances in food production have been made in China, but the continuous increase of nutrient inputs has caused a series of environmental problems. Nutrient management for crops must be improved. Yield gaps, indigenous nutrient supplies, and nutrient use efficiencies (NUEs) must be assessed to design management strategies for further yield increase. In this study, data from 1022 field experiments with wheat (Triticum aestivumL.) conducted between 2000 and 2008 in north central China, the middle and lower reaches of the Yangtze River, and northwest China were analyzed. Treatments in these experiments consisted of a check without fertilizer use, an optimum nutrient application, the farmers’ practice, and a series of nutrient omission treatments. The results showed that gaps between attainable yields and yields in experimental plots with farmers’ practices averaged 0.76 Mg ha−1. Indigenous nutrient supplies of N, P, and K averaged 133.0, 30.2, and 131.7 kg ha−1, respectively, in the regions studied. On a national scale and under optimum fertilization, agronomic efficiency of N, P, and K were 9.8, 19.2, and 7.2 kg kg−1, while recovery efficiencies were 37.9, 19.0, and 27.0%, respectively. Compared with values obtained 10 yr previous, agronomic efficiencies and recovery efficiencies determined between 2000 and 2008 were lower but also lower than world averages. Successive inputs of large amounts of nutrients significantly increased the indigenous nutrient supply and therefore are contributing to lower NUE because recommendations for N, P, and K have not been adjusted downward in China.
Integrated Foliar Disease Management to Prevent Yield Loss in Argentinian Wheat Production
Authors: Simón María Rosa , Ayala Francisco M. , Golik Silvina I. , Terrile Ignacio I. , Cordo Cristina A. , Perelló Analía E. , Moreno Virginia , Chidichimo Hugo O.
Published: September 2011

Zero tillage often leads to wheat (Triticum aestivum L.) yield losses from diseases caused by necrotrophic foliar pathogens. The aim of this work was to evaluate the combined effect of tillage, N fertilization, fungicides, and resistant cultivars in reducing foliar disease severity to prevent significant yield losses. A 2‐yr study including combinations of (i) conventional and zero tillage; (ii) N fertilization rates 0, 80, or 160 kg ha−1 N; (iii) two fungicide treatments (with and without a fungicide (1 L of metconazole, 9%) at growth stages (GS) 32 and 39; and (iv) three wheat cultivars was conducted in the Rolling Pampas region in Argentina. The most common foliar disease in the trial was tan spot [Pyrenophora tritici‐repentis (Died.) Drechs.]. Conventional tillage reduced foliar disease severity at GS 23 by 46 and 56% and the area under disease progress curve (AUDPC) by 20 and 14% for each season, respectively compared with zero tillage. The cultivar Buck Bigua had significantly lower AUDPC values than the others. Fungicide and N application reduced disease severity at GS 23 by 35 and 34% respectively, on average over both years. Disease was less severe in zero tillage plots which received a fungicide compared to conventional tillage plots that were not treated with fungicide. In 2002 yields were greater in conventional tillage plots with 160 kg ha−1 N and fungicide application than in all other treatments. In 2003 yields were greatest in zero tillage plots with 160 kg ha−1 N and fungicide. The results of this study indicate that in spite of the increase of necrotrophic diseases, developing no‐till systems in wheat monoculture is possible without significant yield losses if effective disease management practices are applied.
Integrating Multiple Tactics for Managing Weeds in High Residue No‐Till Soybean
Authors: Nord E. A. , Curran W. S. , Mortensen D. A. , Mirsky S. B. , Jones B. P.
Published: September 2011

Rolled cover crop mulches can suppress weeds in subsequent cash crops, reduce the need for herbicides, and allow organic no‐till cash crop establishment. This study investigated the weed suppressiveness of a cereal rye (Secale cereale L.) cover crop mulch across varying weed seedbank density. Cereal rye was seeded at two dates in the fall and terminated at five dates in the spring to create biomass ranging from 100 to 1600 g m−2. The first three termination dates included both herbicide (glyphosate) and rolling of the rye, while later three dates were only rolled. Soybean [Glycine max (L.) Merr.] was no‐till planted after rye termination, and weed biomass and soybean yield were assessed. Spring termination date more strongly affected cereal rye biomass than fall planting date; a termination delay of 5 to 15 d compensated for a planting delay of 30 d. Weed biomass generally declined with increasing cereal rye biomass, and this relationship was stronger at higher weed seedbank densities. Supplemental weed control reduced weed biomass compared to no supplemental control and postherbicide was more effective than cultivation. While increasing cereal rye biomass was associated with a decline in soybean yield in 2009, it did not consistently impact soybean stand. Instead soybean stand establishment appeared to be impacted by high cover crop biomass and changing edaphic conditions at planting. Future research should focus on improved technology for direct seeding in high residue environments and developing longer term cropping systems less reliant on tillage and herbicides.
An In Vitro Method for Identifying Postattachment Striga Resistance in Maize and Sorghum
Authors: Amusan Idris O. , Rich Patrick J. , Housley Thomas , Ejeta Gebisa
Published: September 2011

Breeding for durable Striga resistance requires identification and stacking of multiple genetic barriers to parasitism in crops. This task would be greatly aided by having screening tools for identifying in parent sources and breeding populations resistance traits that function at various stages in the parasitic association. In this study, we describe a root observation system called the sand packed titer plate assay (SPTPA) used to study early postattachment development of Striga hermonthica (Del.) Benth. on two maize (Zea mays L.) and two sorghum [Sorghum bicolor (L.) Moench] inbred lines selected for field resistance and susceptibility to Striga. The resistant maize and sorghum lines had fewer Striga attachments and these showed delayed parasitic development, and higher mortality compared to those on susceptible cultivars. The SPTPA was useful in identifying specific resistance reactions to S. hermonthica in maize and sorghum and reflected results from field studies of these varieties. This assay would complement field testing during development of Striga‐resistant varieties.
Integrating Multiple Control Options Enhances Striga Management and Sorghum Yield on Heavily Infested Soils
Authors: Tesso Tesfaye T. , Ejeta Gebisa
Published: September 2011

Parasitic weed Striga (Striga hermonthica and Striga asiatica) poses the greatest threat to sorghum [Sorghum bicolor (L.) Moench] production in sub‐Saharan Africa. Several control options have been attempted but none was most effective when deployed individually. In this study combination of three different Striga control options namely resistant variety, tied‐ridge tillage, N fertilizer and their controls (susceptible variety, flat bed plating, and no N fertilizer) were evaluated at two Striga infested locations (Sirinka and Kobo) in Ethiopia in 2002 and 2003. Plots consisted of six 5‐m long rows and the experiment was replicated four times. Grain yield, biomass, and 1000‐kernel weight were determined. Striga emergence and vigor were recorded four times beginning 15 d after the first Striga plant emerged. Grain yield was 121% higher with the package involving the resistant variety, tied‐ridging, and N application compared with the package consisting of the controls. The use of the treatment combination involving resistant variety, tied‐ridges, and N fertilizer resulted in yield increases of 11, 42, and 43%, respectively. Striga emergence and vigor were 4 and 63% for the resistant variety and 85 and 100% for the N fertilizer, respectively, compared with the controls. Number of emerged Striga was 152% higher in tie‐ridged plots but Striga vigor was not affected. Resistant varieties should serve as central component in all integrated approaches for management of Striga in sorghum.
Relationships of Spectral Vegetation Indices with Rice Biomass and Grain Yield at Different Sensor View Angles
Authors: Tubaña B. , Harrell D. , Walker T. , Teboh J. , Lofton J. , Kanke Y. , Phillips S.
Published: September 2011

Changing sensor view angles can alter the proportion of water background in rice (Oryza sativa L.) canopy reflectance spectra. However, its impact on the reported interference of water background in rice fields and performance of spectral vegetation indices (SVI) derived from canopy reflectance as predictors of rice biomass and grain yield is unknown. The objective of this study was to evaluate the relationships of normalized difference vegetation index (NDVI) and simple ratio (SR), measured at different view angles using an active sensor, with rice biomass and grain yield. Sensor readings and biomass at panicle differentiation (PD) and 50% heading, and grain yield were collected from multiple variety × N rate trials established at different rice‐producing areas of the mid‐southern United States in 2009 and 2010. Three sensor view angles were evaluated: nadir 0°, and two off‐nadirs. The relationships of NDVI and SR with biomass and grain yield were exponential and linear (P < 0.05), respectively. At PD, the pattern and values of NDVI and SR with biomass were similar across sensing view angles. At 50% heading, the off‐nadir angles viewed more green vegetation scene from rice stems than the nadir which caused NDVI to approach saturation at a lower biomass level. In addition, there were a higher number of sites where the nadir‐acquired NDVI obtained better exponential relationships with biomass than the off‐nadir view angles. There were larger differences in coefficient of determination (r2) values across site years than view angles implying the larger influence of spatiotemporal variability on NDVI and SR.
Economics of No‐Till Versus Tilled Dryland Cotton, Grain Sorghum, and Wheat
Authors: Varner Brandon T. , Epplin Francis M. , Strickland Gary L.
Published: September 2011

The majority of cropland in the Southwest Oklahoma Agricultural Statistics District is tilled and seeded to continuous monoculture winter wheat (Triticum aestivum L.). This study was conducted to determine the expected yield and expected net returns of wheat, cotton (Gossypium hirsutum L.), and grain sorghum [Sorghum bicolor (L.) Moench], under two production systems, no‐till (NT) and tilled (TL), and to determine the most risk‐efficient system. The effect of tillage was investigated over 6 yr at Altus, OK, on a Hollister silty clay loam (fine, smectitic, thermic Typic Haplusterts) soil. Wheat and cotton yields were not different between tillage systems. Sorghum NT yielded significantly more than TL sorghum (P ≤ 0.05). Wheat NT produced the greatest expected net return to land, labor, overhead, and management ($217 ha−1 yr−1). Tilled grain sorghum was the least profitable system (–$42 ha−1 yr−1). Wheat NT required additional expenditures for herbicides ($15 ha−1), less for machinery fuel, lube, and repairs ($22 ha−1), and less ($23 ha−1) for machinery fixed costs. Net returns were slightly greater ($18 ha−1) for NT wheat than for TL wheat. However, since NT wheat yields were more variable, TL wheat may be preferred by risk‐averse producers. Estimated machinery labor savings from switching from TL to NT wheat were 0.588 h ha−1 or 609 h yr−1 for a 1036 ha farm. The decision to switch from TL to NT wheat depends on risk preferences, and on the potential to use saved labor productively elsewhere, or to farm more land.
Rotating a Field of Mature Miscanthus × giganteus to Glyphosate‐Resistant Crops
Authors: Anderson Eric K. , Voigt Thomas B. , Bollero Germán A. , Hager Aaron G.
Published: September 2011

Miscanthus × giganteus Greef and Deuter ex Hodkinson and Renvoize is a perennial C4 grass being studied as a potential bioenergy feedstock in the United States. It is a triploid, sterile hybrid with high biomass potential. Adoption of a perennial crop is likely to be met with skepticism unless methods of controlling the crop are established. Proposed methods of controlling M. × giganteus typically require at least one full growing season, thus excluding the possibility for revenue from the field for a year. An experiment was conducted from 2007 to 2010 to examine the feasibility of controlling M. × giganteus by planting glyphosate‐resistant soybean [Glycine max (L.) Merr.] followed by glyphosate‐resistant corn (Zea mays L.) directly into a mature (4‐yr old) field of M. × giganteus with typical agronomic practices without significant crop yield loss. Results showed that soybean yields were not significantly reduced with two sequential glyphosate (N‐(phosphonomethyl)glycine) in‐crop applications compared with a weed‐free control, but were generally reduced with one glyphosate application (6.2 and 14.0%, respectively). Corn yields also were not significantly reduced with two sequential glyphosate applications, but were generally reduced with one glyphosate application (0.3 and 7.0%, respectively). Miscanthus × giganteus shoot numbers were reduced by as much as 85.8 and 94.3% over the course of the experiment in plots receiving one and two glyphosate applications per season, respectively. Complete control, however, was not achieved indicating treatments will likely need to be employed for more than two growing seasons to completely control M. × giganteus.
Responses of Fruit Yield and Quality of Processing Tomato to Drip‐Irrigation and Fertilizers Phosphorus and Potassium
Authors: Liu K. , Zhang T. Q. , Tan C. S. , Astatkie T.
Published: September 2011

Water and nutrient management are essential to achieve high yield and desirable quality attributes in processing tomato (Lycopersicon esculentumMill.). A 4‐yr field study (2006–2009) was conducted to assess effects of contrasting water management (drip‐irrigation vs. nonirrigation), fertilizer P (0, 30, 60, and 90 kg P ha−1), and K (0, 200, 400, and 600 kg K ha−1) on yields and quality of processing tomato when the optimum N rate of 270 kg N ha−1was applied. Compared with nonirrigation, drip irrigation increased marketable fruit yield by 127%, total fruit yield by 66%, and fruit size by 32%, while it decreased soluble solids content (SSC) by 19% and lycopene content by 8%, with no effects on dry biomass of stems and leaves (DBSL). Phosphorus addition had no effects on marketable yield and SSC, but increased the DBSL and lycopene content to maximum values at 60 kg P ha−1. Fertilize K rate affected all examined variables but the lycopene content. Increasing K rates from 0 to 200 kg K ha−1increased marketable fruit yield by 10% and total fruit yield by 9%, but fruit size declined by 3%. Increasing K rates from 200 to 600 kg K ha−1, however, had no effects on yield and fruit size. Fertilizer K rate had no effects on SSC with nonirrigation, but resulted in a linear increase in SSC with drip‐irrigation. The results suggested that, with optimum N supply, K application is required to increase fruit yield and quality of drip irrigated processing tomato.
Soil Salinity and Quality of Sprinkler and Drip Irrigated Cool‐Season Turfgrasses
Authors: Sevostianova Elena , Leinauer Bernd , Sallenave Rossana , Karcher Douglas , Maier Bernd
Published: September 2011

A 3‐yr study was conducted in New Mexico to investigate the effects of saline water on changes in quality, cover, and root zone salinity of seven cool‐season turfgrasses. Plots were irrigated using either sprinklers or subsurface drip with water of 0.6, 2.0, or 3.5 dS m−1. From March to November plots were rated monthly for quality, and green cover was determined using digital image analysis. Soil samples were collected at depths of 0 to 10, 10 to 20, and 50 to 60 cm in June and November and analyzed for electrical conductivity (EC), Na, and sodium adsorption ratio (SAR). Changes in soil EC, Na content, and SAR reflected seasonal changes in irrigation and natural precipitation and EC and Na values were highest (6.1 dS m−1 and 943 mg L−1, respectively) in June of 2006 on drip irrigated plots at depths of 0 to 10 cm. Electrical conductivity was higher in drip irrigated than sprinkler irrigated plots on four of the six sampling dates. Irrigation type and water quality did not affect EC and Na at soil depths of 50 to 60 cm. For four of the seven grasses tested, EC, Na, or SAR values showed a significant but weak relationship (0.18 < r2 < 0.27) with turf quality, indicating that more than one stressor affected visual ratings. With the exception of tall fescue [Festuca arundinacea (Schreb.)], cool‐season grasses could not be maintained at acceptable quality levels in the arid transitional climate when irrigated with saline water from either a sprinkler or a subsurface drip system.
Social and Spatial Dimensions of Demographic Processes in Beijing Municipality at the Turn of the 21ST Century
Authors: Chaberko Tomasz , Fedirko Anna , Kretowicz Paweł
Published: September 2011

Social and Spatial Dimensions of Demographic Processes in Beijing Municipality at the Turn of the 21ST Century

This study focuses on the demographic processes in Beijing Municipality at the turn of the 21st century and attempts to evaluate a role of China's social policies upon contemporary population changes. Two main determinants influencing present demographic characteristics were taken into consideration: the immigration of temporary workers and one-child policy. Socio-economic processes in Beijing are accompanied by the rapid changes of urban physiognomy as a result of immense city development (new industrial and residential areas) and new investments prepared for the 2008 Olympics. A spatial typology of socio-demographic changes between 1997 and 2007 was created in order to distinguish areas of different demographic and social development. Concluding remarks of this study highlight main characteristics and determinants of Beijing Municipality demographic features and a pace of their changes. Evidences typically found in Beijing clearly show a crucial role of market economy elements which have a great effect upon socio-spatial urban expansion.
The Goods Structure of Trade between Polish Regions and the European Union (1)
Authors: Maćkowiak Henryk
Published: September 2011

The Goods Structure of Trade between Polish Regions and the European Union (1)

The goal of this article is to present the structure of trade between Polish regions (voivodships) and the European Union. The research is a dynamic analysis making it possible to compare the time before and after the expansion of the European Union. The timeframe of the discussed issues relates to 1999-2007. Attention is paid to the scale and diversified nature of the changes to the goods structure of export and import activities undertaken by Polish voivodships to (from) the European Union. The analysis is preceded by the characteristics of the European Union's role in trade of specific regions. Finally, the degree of intra-industry specialization is evaluated as is the trend in changes to the trade between Polish regions and European Union countries.
Process of Ageing of Śląskie Voivodship Population Until 2035
Authors: Sojka Elżbieta
Published: September 2011

Process of Ageing of Śląskie Voivodship Population Until 2035

The article presents changes in the structure of population by age in Śląskie voivodship between 1990 and 2035. The similarity of structures has been studied with the use of taxonomic algorithm and the time distributions of senility and load indices of the population in general while taking sex and place of residence into consideration have been presented. The process of population ageing is more and more intensive. Less and less numerous age groups that reach the productive age and more and more numerous age groups that enter the retirement age show that Śląskie voivodship, similarly to the whole area of Poland and other European countries, will have to face the problem of population ageing. This challenge is particularly hard to confront because of the low level of professional activity of the people over 50 years of age.
Typology of Suburban Communities in Poland
Authors: Zębik Grzegorz
Published: September 2011

Typology of Suburban Communities in Poland

The paper presents an attempt to classify new and existing suburban communities in Poland based on spatial patterns and comparisons with suburbs in the United States. Fifteen types of Polish suburban communities are identified in the paper. As large-scale suburban development is a relatively new phenomenon in Poland, most Polish suburban communities will continue to evolve over time and make the transition from one community type to another. An understanding of each type of suburban community may help local governments assist the communities they serve in the process of creating infrastructure and jobs for a growing population.
Effect of UV-B radiations on the pigments of two Antarctic lichens of Schirmacher Oasis, East Antarctica
Authors: Gautam Sanghdeep , Singh Jaswant , Pant Aditya
Published: September 2011

Effect of UV-B radiations on the pigments of two Antarctic lichens of Schirmacher Oasis, East Antarctica

Antarctic plants experience UV-B stress and for their survival they have been showing various adaptive strategies. The first line of defence is to screen UV-B radiation before it reaches the cell, then to minimize damage within the cells through other protective strategies, and finally to repair damage once it has occurred. A fifteen days experiment was designed to study lichen: Dermatocarpon sp. and Acarospora gwynnii under natural UV and below UV filter frames in the Indian Antarctic Station Maitri region of Schirmacher Oasis, East Antarctica. Changes in UV absorbing compounds, total phenolics, total carotenoids and chlorophyll content were studied. The change in total phenolics and total carotenoid content was significant in both Dermatocarpon sp. and A. gwynnii indicating that the increase in UV absorbing compounds, total phenolics and total carotenoid content act as a protective mechanism against the deleterious effect of UV-B radiations, whereas the change in chlorophyll content was not significant in both lichen species.