bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic pattern of morphological variation of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), using multivariate morphometry
Authors: Navia D. , Moraes GJ. , Querino RB.
Published: January 2010

The coconut mite, Aceria guerreronis Keifer, has become one of the most important pests of coconut in the Americas and Africa and recently in Southeast Asia. Despite the great economic importance of this mite, there is a lack of information on its origin and invasion history that are important to guide the search of biological control agents as well as the adoption of quarantine procedures. This study evaluates morphometric variation among A. guerreronis populations throughout its occurrence area, relates this variation with historical sequence of records, looking for information on its biogeography. Samples of 27 populations from the Americas, Africa and Asia were analysed using Principal Component Analysis and Canonical Discriminant Analysis. Results showed significant morphometric variability of A. uerreronis throughout its distribution area, with a high variability among American populations and otherwise a high similarity among African and Asian populations. The geographic pattern of variation of mite populations observed supports the hypothesis that A. guerreronis originated in the Americas and was introduced into Africa and Asia. Some inferences related to taxonomy of Eriophyoidea mites were included.
Aspectos populacionais de Serrapinnus notomelas (Eigenmann, 1915) e Bryconamericus stramineus Eigenmann, 1908 (Characiformes: Characidae) em riachos da bacia do rio Ivinhema, Alto Rio Paraná
Authors: Lourenço Luzia da Silva , Súarez Yzel Rondon , Florentino Alexandro Cezar
Published: January 2010

O conhecimento dos parâmetros populacionais para as espécies de peixes neotropicais é um grande desafio da ictiologia. No presente trabalho analisamos a relação peso/comprimento, parâmetros de crescimento, mortalidade, recrutamento e avaliamos a influência da variação sazonal da precipitação sobre o peso médio dos indivíduos e o padrão de recrutamento para duas espécies de peixes em riachos da bacia do rio Ivinhema, Estado de Mato Grosso do Sul - Brasil. As amostragens foram realizadas mensalmente de janeiro a dezembro/2002, com esforço padronizado entre os locais. A equação que descreve a relação peso total/comprimento padrão para Serrapinnus notomelas é (Peso = 0,0000191 * LS3,106) e para Bryconamericus stramineus é (Peso = 0,0000080 * LS3,193), sendo a constante b significativamente maior que três. O comprimento assintótico para S. notomelas foi de 42,1 mm e para B. stramineus foi de 54,7 mm. Serrapinnus notomelas apresentou maior mortalidade natural (Z = 1,08) do que B. stramineus (Z = 0,93) e maior taxa de crescimento (S. notomelas k = 0,60 e B. stramineus k = 0,54), sendo que S. notomelas apresentou uma menor longevidade (4,99 anos) do que B. stramineus (5,54 anos). O Índice de performance de crescimento (ø) calculado para S. notomelas foi de 3,027, enquanto para B. stramineus foi de 3,208. Constatamos variação sazonal significativa no peso médio ajustado para ambas as espécies estudadas. O padrão de recrutamento para S. notomelas e B. stramineus também segue um padrão sazonal, com dois picos de recrutamento no ano, sendo que S. notomelas apresentou um pico de recrutamento em março e outro em junho, enquanto B. stramineus apresentou um pico em abril e outro em outubro.
Novas referências de rodofíceas marinhas bentônicas para o litoral brasileiro
Authors: Nunes José Marcos de Castro , Guimarães Silvia Maria Pita de Beauclair
Published: January 2010

Sete táxons de rodofíceas marinhas bentônicas são referidos pela primeira vez para o litoral brasileiro: Acrochaetium corymbiferum (Thur. in Le Jolis) Batters, A. liagorae Børgesen, Aglaothamnion herveyi (M. Howe) Aponte, D.L. Ballant. & J.N. Norris, Crouanophycus latiaxis (L.A. Abbott) Athanas., Grallatoria reptans M. Howe e Gelidiella sanctarum Feldmann & Hamel. Gelidiopsis repens (Kütz.) Weber Bosse é pela primeira vez referido para o Oceano Atlântico. As coletas foram realizadas no medio e infralitoral. O material está depositado no Herbário Alexandre Leal Costa. Referência da descrição original, basiônimo, descrição morfológica, distribuição geográfica e comentários taxonômicos são apresentados para cada táxon estudado.
Allometric models for estimating the phytomass of a secondary Atlantic Forest area of southeastern Brazil
Authors: Burger Déborah Moreira , Delitti Welington Braz Carvalho
Published: January 2010

The purpose of this study was to develop and validate equations to estimate the aboveground phytomass of a 30 years old plot of Atlantic Forest. In two plots of 100 m², a total of 82 trees were cut down at ground level. For each tree, height and diameter were measured. Leaves and woody material were separated in order to determine their fresh weights in field conditions. Samples of each fraction were oven dried at 80 °C to constant weight to determine their dry weight. Tree data were divided into two random samples. One sample was used for the development of the regression equations, and the other for validation. The models were developed using single linear regression analysis, where the dependent variable was the dry mass, and the independent variables were height (h), diameter (d) and d²h. The validation was carried out using Pearson correlation coefficient, paired t-Student test and standard error of estimation. The best equations to estimate aboveground phytomass were: lnDW = -3.068+2.522lnd (r² = 0.91; s y/x = 0.67) and lnDW = -3.676+0.951ln d²h (r² = 0.94; s y/x = 0.56).
Mamíferos do Parque Estadual do Desengano, Rio de Janeiro, Brasil
Authors: Modesto Thiago Carvalho , Pessôa Flávia Soares , Enrici Maria Carlota , Attias Nina , Jordão-Nogueira Tássia , Costa Luciana de Moraes , Albuquerque Hermano Gomes , Bergallo Helena de Godoy
Published: January 2010

Mesmo após a devastação de grande parte das suas matas, o Estado do Rio de Janeiro ainda abriga uma grande riqueza de mamíferos terrestres. Contudo, informações sobre abundância e distribuição da mastofauna do Estado ainda são escassas. Este estudo tem como objetivo inventariar os mamíferos do Parque Estadual do Desengano, localizado na região norte do Estado do Rio de Janeiro, uma das regiões menos amostradas e mais alteradas do Estado. O inventário foi realizado utilizando armadilhas do tipo Sherman e Tomahawk, e armadilhas de queda para os pequenos mamíferos não-voadores, redes de neblina para os morcegos, armadilhas fotográficas, avistamentos e relatos de moradores e funcionários do Parque para os mamíferos de maior porte. Nós registramos 56 espécies de mamíferos, das quais 15 constam na lista da fauna ameaçada de extinção do Estado do Rio de Janeiro e 10 na lista da fauna brasileira ameaçada de extinção, incluindo Brachyteles arachnoides. As espécies mais abundantes foram o morcego Sturnira lilium e o roedor Akodon serrensis. Além disso, Thaptomys nigrita, roedor normalmente pouco capturado no Estado, foi relativamente abundante no Parque Estadual do Desengano. Nossos resultados indicam que o Parque abriga 33,7% das espécies de mamíferos com ocorrência conhecida para o Estado, destacando a importância da área para a conservação da fauna do Rio de Janeiro.
Oligochaeta (Annelida: Clitellata) em córregos de baixa ordem do Parque Estadual de Campos do Jordão (São Paulo - Brasil)
Authors: Gorni Guilherme Rossi , Alves Roberto da Gama
Published: January 2010

O objetivo desse artigo foi inventariar as espécies de oligoquetos limnícolas que habitam córregos do Parque Estadual de Campos do Jordão (PECJ). As amostras revelaram 2302 indivíduos, distribuídos em três famílias (Naididae, Enchytraeidae, Tubificidae). Foram inventariadas 17 espécies, sendo elas: Achaeta sp., Allonais paraguayensis, Chaetogaster diastrophus, Nais communis, Nais variabilis, Pristina biserrata, Pristina leidyi, Pristina proboscidea, Pristinella jenkinae, Pristinella longidentata, Pristinella minuta, Pristinella notopora, Pristinella osborni, Pristinella sima, Aulodrilus limnobius, Botrioneurum sp. e Limnodrilus hoffmeisteri. O número total de espécies encontrado representa 24% de todas as espécies de oligoquetos registrados em diversos ambientes aquáticos no Brasil (70), evidenciando a importância deste trabalho, visto que há ainda grandes lacunas no conhecimento da fauna de oligoquetos límnicos no Brasil.
New records of mosquito species (Diptera: Culicidae) for Santa Catarina and Paraná (Brazil)
Authors: Müller Gerson Azulim , Kuwabara Eduardo Fumio , Duque Jonny Edward , Navarro-Silva Mario Antônio , Marcondes Carlos Brisola
Published: January 2010

We provide eight new mosquito species records for Santa Catarina (Limatus flavisetosus Oliveira Castro 1935, Mansonia flaveola (Coquillett 1906), Ma. titillans (Walker 1848), Psorophora forceps Cerqueira 1939, Sabethes xyphydes Harbach 1994, Toxorhynchites bambusicolus (Lutz & Neiva 1913), Tx. theobaldi (Dyar & Knab 1906) and Wyeomyia lassalli Bonne-Wepster & Bonne 1921) and three for Paraná (Ochlerotatus argyrothorax Bonne-Wepster & Bonne 1920, Uranotaenia pallidoventer Theobald 1903 and Wyeomyia pilicauda Root 1928). Additionally, we list all species in these eight genera recorded previously in the two states. The known distribution and possible epidemiological implications of the new species records are discussed.
Relações entre diversidade íctia e fatores hidrodinâmicos de um riacho na bacia do rio Uruguai
Authors: Kaufmann Vander , Pinheiro Adilson
Published: January 2010

Fatores físicos, químicos e ambientais em um curso de água podem influenciar a estrutura e a diversidade das espécies da biota aquática. Entre os fatores físicos têm-se as condições hidrodinâmicas. Variações do escoamento resultam em dinâmicas complexas das populações e comunidades de peixes. Este trabalho tem por objetivo avaliar as correlações entre as variáveis hidrodinâmicas no Arroio Fortaleza, afluente do rio Uruguai, e a diversidade das espécies. A metodologia compreendeu a coleta de dados hidrodinâmicos (profundidade média da coluna de água, velocidade média do escoamento e vazão escoada na seção fluviométrica) e biológicos (coleta de peixes nas áreas de influência das seções fluviométricas). Com os dados biológicos foram calculados os seguintes índices: o de diversidade de Shannon, o de equitabilidade e o de similaridade. Coletaram-se 527 exemplares, de 25 espécies, dentre elas 4 exóticas e 4 ainda não classificadas. Essas 25 espécies estão classificadas em 4 ordens, 7 famílias e 13 gêneros. O índice de Shannon variou entre 1,43 e 2,68 nats/indivíduo. O índice de equitabilidade foi sempre superior a 0,8, indicando que os indivíduos estão bem distribuídos entre as diferentes espécies. O índice de similaridade de Jaccard variou entre 20 e 80%. Os menores valores foram obtidos para a área amostral situada próximo da nascente. As correlações entre o índice de Shannon e as características hidrodinâmicas resultaram em coeficientes R² variando entre 0,59 e 0,83. Estes resultados evidenciam que a diversidade das espécies é influenciada pelas características hidrodinâmicas. No entanto, a profundidade da coluna de água ou a velocidade média do escoamento não são suficientemente significativas para explicar a variabilidade espacial da diversidade das espécies isoladamente.
Shoot-foliage relationships in deciduous, semideciduous, and evergreen cerrado tree species
Authors: Souza João Paulo , Prado Carlos Henrique B. A. , Albino Ana Lúcia S. , Damascos Maria A.
Published: January 2010

The morphology and the biomass allocation in shoots and leaves were investigated in 15 cerrado tree species with distinct leaf phenology growing under natural conditions. Higher values of leaf/shoot ratio on mass base, individual leaf area, leaf area per shoot, leaf display index, and leaf number per shoot length were found in deciduous than in evergreen species. The differences about shoot-foliage relationship across leaf phenological groups could be explained by plagiotropic shoots on deciduous and by erect shoots in semideciduous and evergreen species. Plagiotropic shoots allow similar irradiance along shoots and high biomass allocation in favor of leaves without foliage self-shading in deciduous tree species. The structural differentiation between short and long shoots was indicated by an exponential relationship between leaf display index and shoot length in all deciduous, in three semideciduous, and in two evergreen species. Therefore, especially in deciduous, the short shoots had higher leaf area per unit of length than the long shoots. The differentiation between short and long shoots depends on the shoot length in deciduous because of the leaf number on shoot is predetermined in buds. Contrastingly, the leaf neo-formation in semideciduous and in evergreen tree species keeps the shoot-leaf relationship per shoot length more constant, because of the foliage being produced according to the shoot growth during the year. In conclusion, the foliage persistence, the shoot inclination, the type of leaf production and the resources allocation between autotrophic and heterotrophic vegetative canopy parts are interdependent in cerrado tree species across different leaf phenological groups.
Perviedade e complicações no seguimento de cateteres venosos totalmente implantáveis para quimioterapia
Authors: Miranda Robson Barbosa de , Lopes Jocefábia Reika Alves , Cavalcante Rafael Noronha , Kafejian Ohannes
Published: January 2010

CONTEXTO: A disponibilidade de acesso venoso nos pacientes que recebem cursos prolongados de terapia citotóxica é de grande importância para o sucesso do tratamento. Os cateteres totalmente implantáveis vêm sendo cada vez mais utilizados para a referida terapia, proporcionando melhoria na qualidade de vida dos doentes. OBJETIVO: Avaliar a perviedade e complicações dos cateteres venosos totalmente implantáveis instalados nos pacientes oncológicos. MÉTODOS: Estudo longitudinal retrospectivo com 74 pacientes submetidos a colocação de cateter totalmente implantável de janeiro de 2004 a fevereiro de 2007. RESULTADOS: Foram inseridos cateteres venosos totalmente implantáveis em 74 pacientes com idade média 48,9 anos, predominando o sexo feminino. As neoplasias mais prevalentes foram mama (40,5%), cólon (20,8%) e linfoma (18,9%). Houve predomínio do acesso venoso pela via cervical (74,3%), com utilização da veia jugular interna em 45,9% dos casos. Somente 13,5% dos acessos ocorreram por punção da veia subclávia. A duração média de uso dos cateteres foi de 335,33 dias. Trinta e seis doentes (48,6%) mantiveram-se com o cateter após o término da quimioterapia. Sessenta e sete doentes (90,5%) não apresentaram complicações. Entre as complicações precoces, houve um (1,4%) pneumotórax e um (1,4%) hematoma na loja de implantação. Entre as complicações tardias, ocorreram cinco (6,7%) infecções. Foram retirados 10 (13,5%) cateteres, cinco devido às complicações e cinco por término do tratamento. Houve 11 (14,9%) óbitos de pacientes em decorrência do câncer, com o cateter funcionante. CONCLUSÃO: Os resultados obtidos demonstram baixa taxa de complicações, confirmando a segurança e conveniência do uso dos acessos totalmente implantáveis em paciente em regime de quimioterapia.
Teoria ator-rede e estudos críticos em administração: possibilidades de um diálogo
Authors: Alcadipani Rafael , Tureta César
Published: January 2010

O objetivo deste artigo é questionar se a teoria ator-rede (TAR) seria, de fato, incapaz de contribuir para análises criticas nos estudos organizacionais. Discutimos, então, as princpais características dos estudos críticos em administração, bem como seu desenvolvimento no contexto brasileiro. Apresentamos ainda alguns dos conceitos iniciais da TAR, que foram alvo de críticas não apenas por naturalizarem as organizações e transmitirem a ideia de que o processo de ordenação é estático, podendo ser entendido de maneira mecânica, mas também por desconsiderarem a dimensão política em suas análises. Como forma de superar tais limitações, que dificultariam um posicionamento crítico da TAR, analisamos os novos desenvolvimentos dessa abordagem, conhecidos como TAR e Depois, que redefiniram algumas de suas principais noções, possibilitando adotar essa perspectiva como "instrumento" analítico crítico das organizações. Concluímos que muitas das críticas direcionadas à TAR, no que concerne ao seu caráter acrítico e não-reflexivo, já não se sustentam mais, em função dos novos desdobramentos emergidos da TAR e Depois.
Structure and dynamics of the macrobenthic communities of Ubatuba Bay, southeastern Brazilian Coast
Authors: Santos Maria Fernanda Lopes dos , Pires-Vanin Ana Maria S.
Published: January 2010

Species composition, distribution, density, biomass, diversity and trophic relationships of the macrobenthic communities in Ubatuba Bay, southeastern Brazilian coast, were investigated seasonally from August 1995 to June 1996. Sampling was carried out at 9 stations of between 4 and 13 m depth and taken in duplicate with a 0.1m² van Veen grab. Two hundred and five macrofaunal species were identified, presenting low dominance and frequency. Polychaetes and nematodes dominated, representing 89% of the whole fauna. Spatial variations in the structure of the communities were correlated to sediment type whereas seasonal variations were correlated to the increase in wave size and current disturbance over the substrate during the rainy period. Carnivore and surface deposit-feeder polychaetes were dominant, totalling 81% of the species. Mean grain size, fine sand, very fine sand, silt and clay contents were among the main factors related to the patterns of macrofaunal distribution, density and diversity and to the dominance of trophic groups. Multivariate analysis showed that the area may be divided into two groups of stations each of them characterized, respectively, by the presence of Magelona papillicornis and Mediomastus capensis.
Land-ocean fluxes in the Paranaguá Bay estuarine system, southern Brazil
Authors: Marone Eduardo , Machado Eunice C. , Lopes Rubens M. , Silva Eduardo Teixeira da
Published: January 2010

A worldwide modeling effort has been proposed by the LOICZ (Land-Ocean Interactions in the Coastal Zone) Program to foster the acquisition of intercomparable data on land-ocean fluxes in estuaries and continental shelf ecosystems from all continental margins. As part of the South American component of this initiative, we present flux estimates of water, salt, dissolved inorganic phosphorus (DIP), dissolved inorganic nitrogen (DIN) and plankton for the estuarine system of Paranaguá Bay, southern Brazil, based on the LOICZ modeling approach and local data obtained during the 1990's. This system is strongly influenced by a seasonal meteorological cycle, represented by the rainy/summer and dry/winter periods. Semi-diurnal tides of up to the 2.7-m range are responsible for the short time-scale dynamics. The model indicated a potential water export to the adjacent coast of up to 7 x 10(6) m³ d-1 in the dry season, and 28 x 10(6) m³ d-1 during the rainy season. The system exhibits seasonal and spatial variations in DIP and DIN fluxes. "DIP amounted to +2.3 x 10(6) mol P yr-1 and "DIN to -2.7 x 10(6) mol N yr-1, suggesting that net production of phosphate and consumption of inorganic nitrogen predominate throughout in the system. Fluxes and therefore export of DIN and eespecially of DIP are higher in the rainy season. Stoichiometric estimates based on the C:N:P ratios of the reacting particulate organic matter (mangrove and plankton detritus) suggest that net denitrification predominates all over the bay, with values between -24.3 and -10.6 x 10(6) mol N year-1. Estimated seaward outflows had little effect upon the fate of the phyto- and zooplankton biomass in different sectors of the bay. This is exemplified by the low net export of algal production from the upper to the middle sectors of the estuary.
Virtual population analysis of two snapper species, Lutjanus analis and Lutjanus chrysurus, caught off Pernambuco State, north-eastern Brazil
Authors: Mattos Sérgio Macedo Gomes de , Maynou Francesc
Published: January 2010

We applied steady-state Virtual Population Analysis - VPA to two stocks of snappers (Lutjanus analis and L. chrysurus) exploited by artisanal hand-line fleets along the Pernambuco State coast (North-eastern Brazil). We show that even short-data series (1 year of sampling) can produce a useful diagnosis of fisheries resources. Both stocks are slightly overexploited by the hand-line fishery and a higher yield-per-recruit would be obtained by a reduction of effort of 16% for L. analis and 43% for L. chrysurus. Given the impracticability of managing the two stocks separately, we propose a 25% decrease of fishing effort for the hand-line fleet. By incorporating the results of VPA into a simulation framework, we can develop a comparison of the likely result of different policy options (effort regulation) based on 3 simple indicators (Spawning stock biomass-per-recruit, biomass-perrecruit and yield-per-recruit). We compare the results of effort reduction with those of effort increase (25%) through simulation analysis. Allowing for the difficulty of testing assumptions introduced in our model (steady-state, Beverton and Holt recruitment model) and using standard fisheries analysis techniques, we show that useful fisheries advice can be produced even in a context of limited data. Providing advice to developing countries coastal fisheries is an urgent issue, given the high dependence of local communities on coastal living resources and the increasing fishing effort applied by a growing population.
Uso da broncoscopia virtual em pacientes pediátricos com suspeita de aspiração de corpo estranho
Authors: Veras Tiago Neves , Hornburg Gilberto , Schner Adrian Maurício Stockler , Pinto Leonardo Araújo
Published: January 2010

A aspiração de corpo estranho (ACE) para o trato respiratório é um problema comum em pacientes pediátricos, em especial abaixo dos três anos de idade. Na avaliação radiológica inicial, cerca de 30% dos pacientes apresentam radiograma de tórax normal. A tomografia com broncoscopia virtual (BV) pode auxiliar no diagnóstico precoce desse quadro e seu pronto manejo. O tratamento definitivo se dá com a retirada do corpo estranho através de broncoscopia rígida e mediante anestesia geral. O objetivo deste trabalho foi descrever o uso da BV na abordagem de dois pacientes com suspeita de ACE e realizar uma revisão da literatura sobre este tópico. Os dois pacientes tiveram início súbito de sintomas respiratórios e relato de tosse ou engasgo com alimentos antecedendo o quadro. Os pacientes foram submetidos à BV, e foi detectada a presença de corpo estranho endobrônquico em ambos os casos, com remoção posterior por broncoscopia rígida convencional em um caso. A BV é um método não-invasivo recente e com potencial para detectar a presença de corpo estranho na via respiratória em crianças. Em casos selecionados, BV pode auxiliar na localização correta do corpo estranho e até mesmo evitar o procedimento de broncoscopia rígida na ausência de corpo estranho.
9 cenas, algumas obs-cenas, da rua
Authors: Pechman Robert Moses
Published: January 2010

Importa aqui tomar o acontecimento urbano como sintoma da cidade. Mas de que sofre a cidade? De excesso de individualismo e do escasseamento da vida pública na rua. Mas se o que caracteriza a cidade é o acolhimento do Outro, que se desdobra em convivialidades e em sociabilidades, como podemos pensar numa cidade sem que a questão da hospitalidade venha à tona? À propósito dessa contradição entre cidade e individualismo e privativismo e hospitalidade, me ponho a observar nossas ruas e a divisar certas cenas urbanas, depreendendo daí o que essas cenas podem nos contar de um ethos citadino. E, sim, elas nos contam muitas coisas de uma nova paisagem urbana/humana que insiste em desmanchar a imagem do acolhimento como a cena primordial da cidade, impondo sua obscena verdade, sua cena obs-cena.
Characterization of Resistance to Fusarium Head Blight in an Eastern U.S. Soft Red Winter Wheat Population
Authors: Sneller Clay H. , Paul Pierce , Guttieri Mary
Published: January 2010

Host resistance is important to control Fusarium head blight (FHB) ), caused by the fungus Fusarium graminearum (Schwabe) [teleomorph: Gibberella zeae (schw.) Petch], in wheat (Triticum aestivum L.). Effective breeding requires understanding the genetics of resistance in breeding populations. Our objective was to deduce the genetics of FHB resistance in eastern U.S. soft red winter wheat (SRWW) by estimating heritability, means, and phenotype frequencies. We evaluated the FHB index of 2983 lines from 223 parents in a series of single‐ and multiyear trials conducted in inoculated FHB nurseries. The mean index of all lines (23.8%) was similar to that of the moderate resistant check (19.7%), and the distribution was often skewed toward low index values. Without selection, 41% of all lines had moderate resistance and 70% of all crosses produced such lines. Entry‐mean heritability for index generally exceeded 0.65 and selection for lower index reduced the index by −37%. The moderate resistance arose from many SRWW parents with varying levels of FHB resistance. The genetics of resistance in this population is probably characterized by a relatively high frequency of resistance alleles at multiple loci, dispersed over many parents that differ in allele content at loci controlling FHB resistance. This population should provide excellent gain from recurrent selection and complement current marker‐assisted selection efforts.
Corn Morphology, Mass, and Grain Yield as Affected by Early‐Season Red: Far‐Red Light Environments
Authors: Markham Melinda Y. , Stoltenberg David E.
Published: January 2010

The spatial arrangement among plants affects both vegetative and reproductive meristem development. More axillary meristems develop at lower plant densities, which are associated with relatively high red:far‐red light ratios (R:FRs; 645:735 nm). However, little is known about the effect of R:FR on corn (Zea maysL.) productivity. We conducted field research to determine the effect of early‐season (VE–V7 corn) R:FR environments on corn morphology and productivity. Low, control, and high R:FR treatments were established by varying corn plant density (107,600, 53,800, and 3000 plants ha−1, respectively). At canopy closure (V7 corn), R:FR in the low, control, and high R:FR treatments was 0.23, 0.49, and 0.99, respectively. Each treatment was subsequently thinned to 3000 plants ha−1to avoid confounding effects of R:FR treatments and shading among plants. Grain yield per plant in the high R:FR treatment was 1.5 and 2.0 times greater than in control and low R:FR treatments, respectively, across years. Greater yield in the high R:FR treatment was attributed to greater tiller grain yield. Soil moisture and nutrient availability were similar among R:FR treatments. These results indicate that early‐season R:FR was an important factor affecting corn productivity. Greater understanding of the R:FR‐dependent pathway that controls axillary meristem development may provide direction for increasing productivity of elite nonprolific corn genotypes.
Vegetative Phase Change Characteristics and Resistance to Common Rust of Corn Cultivars Developed in Different Eras
Authors: Riedeman E. S. , Tracy W. F.
Published: January 2010

Since 1930, maize (Zea mays L.) yields in the United States have increased more than fourfold. Previous studies examining maize cultivars grown during that period have documented changes in yield, leaf angle, tassel size, drought tolerance, and insect resistance, but none have examined changes in vegetative phase change or resistance to common rust (Puccinia sorghi Schwein.). Vegetative phase change has been shown to affect both disease and insect resistance, and common rust can reduce yields in maize especially east of the Mississippi River. Thirty‐six widely used northern Corn Belt cultivars spanning the years of pre‐1930 to 2006 were evaluated for phase change traits and rust resistance. Cultivars were divided into early and late maturity groups from different eras and planted at two locations with two planting dates per location for 2 yr. Timing of vegetative phase change has not changed linearly over the eras examined. There was, however, a significant linear increase in rust resistance over that time. In the early maturity group, percentage of leaf area infected by rust was found to decrease at a rate of 0.1% yr−1 Whole‐plant rust resistance in the late maturity group was found to increase at a rate of 0.05% yr−1.
A Model to Predict Diurnal Pollen Shed in Maize
Authors: Viner Brian J. , Westgate Mark E. , Arritt Raymond W.
Published: January 2010

We have developed a mathematical model to predict the diurnal pattern of maize (Zea mays L.) pollen shed on the basis of local meteorological conditions. Our goal is to improve simulations of maize pollen dispersion that have typically released pollen at a constant rate in contrast with measurements of pollen shed that show diurnal variation in the rate of shed. Measurements coupling pollen shed and local meteorological variables were made during controlled experiments and a 2004 field experiment to examine the influence of meteorological conditions on pollen shed. From these data, a model was developed to predict the diurnal pattern of pollen shed as a function of vapor pressure deficit, solar radiation, temperature, and the amount of pollen remaining to be shed. The model was validated by predicting the rate of pollen shed, normalized by the daily total of pollen shed, that occurred hourly for days during a 2003 field study () and results from van Hout et al. (2008; ). The model captured the general trend of pollen shed and predicted the time of peak shed within an hour of the measured peak on most days. The model, however, tended to underpredict the magnitude of the normalized peak rate of shed and did not account for secondary peaks in pollen shed that were occasionally observed. Thus, future model refinements will depend on identifying additional biological or environmental factors that impact the instantaneous rate of pollen shed.
Green Tea Catechins Applied to Susceptible Hosts Inhibit Parasitic Plant Attachment Success
Authors: Lewis Kristin C. , Alers‐García Janice , Wright Leslie J.
Published: January 2010

Parasitic plants utilize cell wall degrading enzymes (CWDEs) to penetrate their host plant and attach to host vasculature. Inhibition of CWDEs may confer resistance on susceptible hosts, offering a strategy for parasitic plant control. Here, exogenous application of green tea catechins, which inhibit pectin methylesterase (a CWDE), was used to delay parasitic plant attachment. Texas bluebonnet (Lupinus texensisHook.) was grown with its naturally occurring root hemiparasite, Texas paintbrush (Castilleja indivisaEngelm.). Catechins, fertilizer (ammonium nitrate), or water were added to soil twice weekly. Parasite attachment was detected using Dragendorff reagent. Effects on growth and germination were also assessed. Parasite attachment to the host was prevented by 5 g L−1of catechins through 20 d and reduced through 36 d after parasite seedling addition. Five grams per liter of catechins delayed germination in Texas bluebonnet but not in Texas paintbrush. To test the effects of CWDE inhibitors on aboveground parasitism,Arabidopsis thaliana(L.) Heynh. seedlings were grown with field dodder (Cuscuta pentagonaEngelm.), a promiscuous shoot holoparasite. Ten grams per liter of catechins applied to theA. thalianashoot surface inhibited field dodder attachment, although prehaustorial development was not affected. Our findings corroborate existing evidence that CWDE inhibition is a critical component of natural resistance to parasitic plants and open a new area of research into the use of exogenous CWDE inhibitors to control parasitic plant attachment.
Validation of Molecular Markers Associated with Net Blotch Resistance and Their Utilization in Barley Breeding
Authors: Grewal Tajinder S. , Rossnagel Brian G. , Scoles Graham J.
Published: January 2010

With the advancement of molecular marker technology and computer software, mapping quantitative trait loci (QTL) for complex traits in agricultural crops is frequent; however, exploitation of these QTL in practical breeding programs is limited. Here we report the validation of molecular markers linked to net blotch resistance QTL and their utilization in a barley (Hordeum vulgare L.) breeding program. Barley net blotch, caused by Pyrenophora teres Drechs. [anamorph: Drechslera teres (Sacc.) Shoemaker], is a serious foliar disease in Canada and other parts of the world. Simple sequence repeat (SSR) markers linked to net‐form net blotch (NFNB) resistance QTL (QRpt6) and spot‐form net blotch (SFNB) resistance QTL (QRpts4) were validated in two barley populations unrelated to the original mapping population. Marker‐assisted selection (MAS) was performed with SSR markers to select resistant and susceptible lines in two other populations. The lines homozygous for the resistant‐parent alleles at both marker loci had significantly lower infection than lines homozygous for the susceptible‐parent alleles at both markers, indicating that MAS for net blotch resistance is practical. Since the major QTL, QRpt6, may provide adequate NFNB field resistance in western Canada, the plan for the Crop Development Centre (CDC) barley breeding program is to routinely utilize MAS for QRpt6 followed by normal field screening in disease nurseries to select the most resistant lines having additional resistance provided by less critical genes associated with other identified QTL. The CDC program has implemented routine MAS for QRpt6 and recommends this approach to other barley breeding programs.
Seed Yield, Development, and Variation in Diverse Poa pratensis Accessions
Authors: Johnson R. C. , Johnston W. J. , Bertoli F. B. , Golob C. T.
Published: January 2010

Post‐harvest residue removal is critical for high seed production of Kentucky bluegrass (Poa pratensis L.). Previous work showed some accessions have little yield reduction with mechanical removal of post‐harvest residue compared with the controversial practice of open‐field burning. Using 10 of these accessions, our objectives were (i) to relate seed yield and yield components in spaced plants to yield in row‐seeded plots, (ii) to link yield to growth and development factors, and (iii) to determine variation for seed production factors among accessions. Seed yield, seeds per panicle, panicle number, weight per seed, heading, anthesis, and harvest dates showed strong accession differences on spaced plants in 2002 and 2003. Yields in row‐seeded plots from 1998 and 1999 data were consistently correlated with yield per plant per area in spaced plants in 2002 (r = 0.75, P < 0.05) and 2003 (r = 0.90, P < 0.01). Turf quality was negatively correlated with yield per plant per area in 2002 and 2003 but was not consistently correlated with yield components. Days from heading to anthesis consistently correlated with yield per plant per area in 2002 (r = 0.81, P < 0.01) and 2003 (r = 0.85, P < 0.01). Variation for seed yield and yield components was observed within accessions both years and differed among accessions. The results show that seed yield per plant per area in spaced plants may be a useful predictor of yield in field stands and that a long heading to anthesis period promotes seeds per panicle and seed yield.
Molecular Mapping of Wheat Leaf Rust Resistance Gene Lr42
Authors: Sun Xiaochun , Bai Guihua , Carver Brett F. , Bowden Robert
Published: January 2010

Leaf rust, caused by Puccinia triticina Eriks., is an important foliar disease of wheat (Triticum aestivum L.) worldwide. Leaf rust resistance gene Lr42 from Aegilops tauschii Coss. has been used as a source of rust resistance in breeding programs. To identify molecular markers closely linked to Lr42, a segregating population of near‐isogenic lines contrasting for the presence of Lr42 was developed in the hard winter wheat cultivar Century background and evaluated for rust infection type at both seedling and adult‐plant stages. Simple sequence repeat (SSR) markers were screened using bulked‐segregant analysis. Two markers closely linked to Lr42 were identified on chromosome 1DS. The closest marker, Xwmc432, is about 0.8 cM from Lr42. Physical mapping of both SSR markers using Chinese Spring nullitetrasomic and ditelosomic genetic stocks confirmed that the markers linked to Lr42 were on 1DS. Markers for Lr42 were highly polymorphic between parents and among a diverse set of wheat germplasm collected from several countries, indicating that these markers are useful for marker‐assisted selection for Lr42.
Feasibility of Seed Production from Nonflowering Orchardgrass
Authors: Casler M. D. , Johnson R. C. , Barker R. E. , Jenderek M. M. , Papadopoulos Y. A. , Cherney J. H.
Published: January 2010

Nonflowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems. Our objective was to quantify seed production on nonflowering orchardgrass clones selected in cold‐winter climates, but grown for seed in mild‐winter climates. We evaluated 98 orchardgrass clones for seed production traits at four locations. Most plants (∼92%) flowered at the three northern locations, but only 38% flowered at Parlier, which may have a winter insufficiently cold for adequate floral induction and vernalization. Mean panicle number was lowest (11%) for plants selected at the location with the warmest winter conditions, and highest (37%) for plants selected at the location with the coldest winter conditions. These results confirm our expectations that the most desirable plants (nonflowering under cold winters and normal flowering under mild winters) should arise from selection under more severe winters. Selection for nonflowering under mild winter conditions simply leads to nonflowering plants under all conditions. These results demonstrate that individual orchardgrass genotypes are capable of dual phenotypic expression, flowering in mild‐winter climates or expressing the nonflowering trait in cold‐winter climates and that the expression of this trait depends on both the selection and evaluation location.
Response of Oat Genotypes to Fusarium Head Blight in Eastern Canada
Authors: Yan Weikai , Fregeau‐Reid Judith , Rioux Sylvie , Pageau Denis , Xue Allen , Martin Richard , Fedak George , de Haan Brad , Lajeunesse Julie , Savard Marc
Published: January 2010

Recent investigations in northern Europe and western Canada suggested that mycotoxins caused by Fusarium head blight (FHB) could be a potential problem for oat (Avena sativa L.) production and oat food safety. Here we report studies conducted in eastern Canada to address this issue. In one study, oat genotypes of diverse origin were evaluated for grain and groat deoxynivalenol (DON) contamination owing to artificial FHB inoculation at Ottawa, ON, in 2006 and 2007. In a separate study, oat genotypes tested in the yearly Quebec Oat Registration and Recommendation Trials were evaluated for DON contamination due to artificial inoculation in Quebec from 2003 to 2008. Deoxynivalenol was detected in all tested genotypes, and up to 43 μg g−1 of DON was observed in the oat grain. Up to 86% of the DON in the oat grain was removed by dehulling. However, some genotypes still retained up to 9 μg g−1 of DON in the groat. Genotype ranking in DON content was relatively consistent across years, planting dates, and experiments, and genotypes with consistently low and high DON levels were identified. It was concluded that FHB is a potential problem for oat production and oat food safety under high FHB pressures; however, the severity of this problem needs to be further assessed by extensive monitoring of the DON level under natural conditions. The most susceptible genotypes identified in this study can be useful for this purpose.
Probability of Yield Response to Inoculants in Fields with a History of Soybean
Authors: De Bruin J. L. , Pedersen P. , Conley S. P. , Gaska J. M. , Naeve S. L. , Kurle J. E. , Elmore R. W. , Giesler L. J. , Abendroth L. J.
Published: January 2010

Inoculants containing Bradyrhizobium japonicum are available for soybean [Glycine max (L.) Merr.] production but may not be necessary in fields where soybean previously has been produced. The objective of this study was to determine yield response and probability of an economic return from inoculants in fields with a recent history of soybean production. Fifty‐one inoculant products were evaluated in experiments (n = 73) conducted in Indiana, Iowa, Minnesota, Nebraska, and Wisconsin between 2000 and 2008. Inoculant products were similar and did not produce a yield response relative to an untreated control different from zero (P > 0.05) at 63 environments. Probability for a break‐even economic return at a soybean sale price of $0.33 kg−1 was 59% for Nebraska, 36% for Wisconsin, 25% for Minnesota, 25% for Indiana, and 4% for Iowa. Attaining a return on investment of 67 kg ha−1 (a 2:1 return) reduced success to 11, 2, 1, 7, and 0.2%, for the five states, respectively. Data from this range of environments and products indicate that application of an inoculant offers limited success for either a yield increase or improved economic return on soils where soybean has previously been grown in the upper Midwest.
Genotypic Variation in Peanut for Transpiration Response to Vapor Pressure Deficit
Authors: Devi M. Jyostna , Sinclair Thomas R. , Vadez Vincent
Published: January 2010

Conservation of soil water resulting from decreases in stomata conductance under atmospheric high vapor pressure deficit (VPD) conditions is a possible approach for enhanced tolerance of water deficit by crops. Water deficit is usually a concern in peanut (Arachis hypogea L.) since it is frequently grown on sandy soils with low water‐holding capacity. Seventeen peanut genotypes were studied to determine the response of their transpiration rates (TR) to VPD. The results of this study demonstrated variation among peanut genotypes with nine genotypes exhibiting a breakpoint in their VPD response at about 2.2 kPa, above which there was little or no further increase in TR. Therefore, these genotypes with a breakpoint have the possibility of soil water conservation when VPD exceeded 2.2 kPa. The remaining eight genotypes had a linear response in TR over the whole range of tested VPD. Also, the 17 genotypes could be separated into groups with differing rates of increasing TR at low VPD. The change in TR with increasing VPD may be important in determining the rate at which soil water is used under field conditions.
Multiseason Recoveries of Organic and Inorganic Nitrogen‐15 in Tropical Cropping Systems
Authors: Dourado-Neto D. , Powlson D. , Bakar R. Abu , Bacchi O. O. S. , Basanta M.V. , Cong P. thi , Keerthisinghe G. , Ismaili M. , Rahman S. M. , Reichardt K. , Safwat M. S. A. , Sangakkara R. , Timm L. C. , Wang J. Y. , Zagal E. , van Kessel C.
Published: January 2010

In tropical agroecosystems, limited N availability remains a major impediment to increasing yield. A15N‐recovery experiment was conducted in 13 diverse tropical agroecosystems. The objectives were to determine the total recovery of one single15N application of inorganic or organic N during three to six growing seasons and to establish whether the losses of N are governed by universal principles. Between 7 and 58% (average of 21%) of crop N uptake during the first growing season was derived from fertilizer. On average, 79% of crop N was derived from the soil. When15N‐labeled residues were applied, in the first growing season 4% of crop N was derived from the residues. Average recoveries of15N‐labeled fertilizer and residue in crops after the first growing season were 33 and 7%, respectively. Corresponding recoveries in the soil were 38 and 71%. An additional 6% of the fertilizer and 9.1% of the residue was recovered by crops during subsequent growing seasons. There were no significant differences in total15N recovery (average 54%) between N from fertilizer and N from residue. After five growing seasons, more residue N (40%) than fertilizer N (18%) was recovered in the soil, better sustaining the soil organic matter N content. Long‐term total recoveries of15N‐labeled fertilizer or residue in the crop and soil were similar. Soil N remained the primary source of N for crops. As higher rainfall and temperature tend to cause higher15N losses, management practices to improve N use efficiency and reduce losses in wet tropical regions will remain a challenge.
On the Theory of Electrostatic Interactions in Suspensions of Charged Colloids
Authors: Mulder Willem H.
Published: January 2010

This study assessed the relative merits of the Derjaguin–Landau–Verwey–Overbeek and Sogami–Ise theories for the description of the electrostatic interaction between like‐charged colloid particles in an electrolyte solution, which differ qualitatively in their predictions of the nature of this interaction. The former implies a repulsion at all distances with a screened‐Coulomb (or Yukawa‐type) dependence on distance, whereas the latter leads to an electrolyte‐mediated, long‐range attraction. The Sogami–Ise result for the interaction potential depends critically on the notion that the electrostatic parts of the Helmholtz and Gibbs energies of an electrolyte solution are different. By elaborating on the thermodynamic implications of this assumption, it was determined that it leads to a conflict with well‐established results, in particular the relation between osmotic pressure and solvent chemical potential, already at the Debye–Hückel level. For this reason alone, the Sogami–Ise theory is untenable. The condensation and ordering phenomena observed with charged colloids in low‐ionic‐strength solutions, which the Sogami–Ise theory was originally designed to explain, can be interpreted without the need to resort to long‐range electrostatic attraction, as has been demonstrated in previously published work.
Characteristics of Positive Autobiographical Memories in Adulthood
Authors: Bluck Susan , Alea Nicole
Published: January 2010

The characteristics of positive autobiographical memory narratives were examined in younger and older adults. Narratives were content-coded for the extent to which they contained indicators of affect, sensory imagery, and cognition. Affect was additionally assessed through self-report. Young adults expressed more positive affect and less sensory imagery in their memory narratives than did older adults. Age differences in cognitive characteristics also appeared: younger adults showed greater causation-insight, and greater tentativeness in retelling their autobiographical memories. Controlling for episodic memory ability eliminated age differences in positive affect but did not affect age differences on other memory characteristics. Results are discussed in terms of the role that positive autobiographical memories play in daily emotional life across adulthood.
Mineralization of teeth and bones of the cave bear (Ursus spelaeus) from the Biśnik Cave, Southern Poland
Authors: Rogóż Anna , Sawłowicz Zbigniew , Socha Paweł , Stefaniak Krzysztof
Published: January 2010

Mineralization of teeth and bones of the cave bear (Ursus spelaeus) from the Biśnik Cave, Southern Poland

The studied bones and teeth of the cave bear (Ursus spelaeus) come from the Biśnik Cave, located in the Częstochowa Upland (Southern Poland). The specimens originate from different geological layers formed since the Odra Glaciation (250-270 thousand years BP). The fossilized bones and teeth were studied using optical microscopy, scanning electron microscopy, X-ray diffraction, FTIR spectroscopy, and INAA. They are built of recrystallized carbonate-rich apatite-(CaOH) and/or apatite-(CaOH). The teeth additionally contain some apatite-(CaF). The lack of collagen and minor REE contents suggest rapid burial and collagen decay in the early stage of diagenesis. The bones and teeth have only limited mineral infillings. In some teeth, Mn-Fe (hydroxy)oxides were found in the dentine canaliculi and in bones, some osteocyte lacunae contain Fe (hydroxy)oxides with admixture of Mn. In one bone specimen, calcite infillings are present in Haversian canals. The infillings formed during later stages of diagenesis and were succeeded by non-filled cracks.