5,403 research outputs found
Morphological, biochemical and molecular characterization of sorghum (Sorghum bicolor) genotypes contrasting for phosphate use efficiency.
We compared three Pi-efficient (ATF-14B, ATF-53B, 101B) and four Pi-inefficient (ATF-16B, 116R, 136B, 187R) sorghum genotypes under different Pi concentrations. There were no significant differences between the groups in Pi-use efficiency under Pi-deprivation for anthocyanin accumulation, dry-weight matter, acid phosphatase activity (APA), and aerenchyma formation. However, both groups showed anthocyanin accumulation under Pi-deprivation. Under Pi-deficiency, there was a significant reduction of dry weight in both groups, with no significant differences between contrasting genotypes. All genotypes exhibited a significant increase in root/shoot ratios during Pi-deficiency, and these changes were not related to Pi-use efficiency. The total Pi content in roots and shoots in all genotypes was similar and represented less than 0.2 % of the total dry weight. For all genotypes, the Pi content in P+ treatment resulted in a significant variation ranging from 0.45 to 0.85% and 0.41 to 0.66% in roots and shoots, respectively. The genotype 187R had the highest P content in roots and shoots. APA activity showed increased activity only in the roots of both groups. The development of aerenchyma was conspicuous in the basal and in the middle root sections of all genotypes grown under different Pi levels. Two sorghum Pi-transporter genes were strongly overexpressed in the middle part of Pi-deprived roots of 136B genotype. We did not find differences that explain the Pi-use efficiency between efficient and inefficient genotypes. More studies are needed to elucidate the complex mechanism of P-utilization by sorghum plants
Efeito do cruzamento sobre o crescimento de caprinos no Ceará.
Cruzaram-se, na Fazenda Iracema, da Empresa de Pesquisa Agropecuaria do Ceara - EPACE -, em Quixada, CE, 420 cabras Sem Raça Definida (SRD) com reprodutores das raças e/ou tipos Nativos - Marota, Canindé, Moxoto, Repartida e SRD - e exoticas Anglo-Nubiana e Bhuj. Pesaram-se as crias ao nascer e a intervalos de 28 dias até 112 dias (desmama) e a cada dois meses, até 12 meses. 0 peso ao nascer, dos descendentes de raças exoticas, foi maior que o das lrças nativas. Subseqüentemente, os pesos foram idênticos em todos os grupos, refletindo efeito materno. Aos 12 meses, os descendentes de Anglo-Nubiana tenderam a ser mais pesados que os de Bhuj e SRD, e estes, que aqueles das raças nativas (22,09; 20,55 e 19 kg). Os descendentes das raças nativas foram levemente inferiores aos de SRD, mostrando que essas raças podem estar estreitamente relacionadas corn o tipo SRD. Os machos foram mais pesados que as fêmeas, ao nascer (2,28 e 1,94 kg) e no período pos-desmama. Os nascidos de partos simples foram mais pesados que os nascidos de partos gemelares, até seis meses de idade. 0 peso da mae no parto influenciou o peso das crias no nascimento. [Cross-breed effect upon the growth of goats in Ceará state]. Abstract: Four hundred and twenty SRD (nondescripted breed) does were cross-breeded at Iracerna Farm of the Empresa de Pesquisa Agropecuária do Ceará in Quixadá, Ceará, CE, Brazil, with sires of the nativo breeds Marota, Canindé, Repartida, Moxotó and SRD and exotic breeds Anglo-Nubian and Bhuj. The kids were weighed at birth and each 28 days up to weaning and each two months frorn weaning to 12 months of age. At birth, livo weight were higher for exotics cross-breeded kids as compared to native ones. Subsequently, live weights were the sarne for ali kids, showing great maternal effect on the growth of kids. By 12 rnonths old Anglo-Nubian cross-breeded kids were heavier than Bhuj and SRD, and these were heavier than the nativo ones (22.09, 20.55 and 19kg). Nativa breed progeny did not show advantage over SRD crosses. This suggests that native breeds may be closely reiated to SRD. Male kids were havier than female at birth (2.28 to 1.94 kg), and even during post-weaning growth. Kids bom single were heavier than twins from birth to Mx month old. Does weight at parturition affected the kids weight at birth
Churn, Baby, Churn: Strategic Dynamics Among Dominant and Fringe Firms in a Segmented Industry
This paper integrates and extends the literatures on industry evolution and dominant firms to develop a dynamic theory of dominant and fringe competitive interaction in a segmented industry. It argues that a dominant firm, seeing contraction of growth in its current segment(s), enters new segments in which it can exploit its technological strengths, but that are sufficiently distant to avoid cannibalization. The dominant firm acts as a low-cost Stackelberg leader, driving down prices and triggering a sales takeoff in the new segment. We identify a “churn” effect associated with dominant firm entry: fringe firms that precede the dominant firm into the segment tend to exit the segment, while new fringe firms enter, causing a net increase in the number of firms in the segment. As the segment matures and sales decline in the segment, the process repeats itself. We examine the predictions of the theory with a study of price, quantity, entry, and exit across 24 product classes in the desktop laser printer industry from 1984 to 1996. Using descriptive statistics, hazard rate models, and panel data methods, we find empirical support for the theoretical predictions
Plásticos biodegradáveis à base de amido reforçados com fibras de coco.
bitstream/item/33764/1/CT10001.pd
Transportadores de fosfato e outros mecanismos adaptativos de plantas cultivadas em solos deficientes em fósforo.
O fósforo (P) é um elemento crucial para a existência das várias formas de vida na terra. Em todo o globo, o incremento da produção agrícola é um desafio constante para responder à demanda crescente da população mundial por alimento. Contudo, a maioria dos solos apresenta quantidades limitadas de P disponível, portanto, inadequados para a agricultura de alta performance. Tradicionalmente, o uso de adubo fosfatado encarece a produção e contamina o meio ambiente, quando aplicado em excesso, sendo incompatível com a implantação de modelos baseados em sustentabilidade. O documento aborda diferentes aspectos da adaptação de plantas e suas interações com organismos do solo nos desafios impostos pela quantidade limitada de P disponível e traz alguns resultados importantes das pesquisas realizadas nas últimas décadas pela equipe multidisciplinar da Embrapa Milho e Sorgo na busca de soluções, principalmente para a escassez de P disponível para as plantas cultivadas nos solos do Cerrado brasileiro
On the impact of product quality attributes on open source project evolution
Several Open Source Software (OSS) projects have adopted frequent releases as a strategy to deliver both new features and fixed bugs on time. This cycle begins with express requests from the project’s community, registered as issues in bug repositories by active users and developers. Each OSS project has its own priorities established by their respective communities. A a still open question is the set of criteria and priorities that influence the decisions of which issues should be analyzed, implemented/solved and delivered in next releases. In this paper, we present an exploratory study whose goal is to investigate the influence of target product quality attributes in software evolution practices of OSS projects. The goal is to search for evidence of relationships between these target attributes, priorities assigned to the registered issues and the ways they are delivered by product releases. To this end, we asked six participants of an exploratory study to identify these attributes through the data analysis of repositories of three well-known OSS projects: Libre Office, Eclipse and Mozilla Firefox. Evidence indicated by the participants suggest that OSS community developers use criteria/priorities driven by specific software product quality attributes, to plan and integrate software releases.info:eu-repo/semantics/acceptedVersio
Resistência de bactérias ácido-láticas a bacteriófagos provenientes de unidades de processamento de queijo Coalho.
Este trabalho teve como objetivos isolar bacteriófagos de amostras de leite, soro e queijo de Coalho e avaliar a resistência de cepas de Lactobacillus paracasei , pertencentes à Coleção de Micro-organismos de Interesse para a Agroindústria Tropical da Embrapa Agroindústria Tropical, aos fagos isolados. Posteriormente, a resistência destas cepas a fagos específicos para L. paracasei, da Coleção do Instituto de Lactología Industrial - INLAIN (Santa Fe, Argentina), também foi avaliada. As amostras para isolamento dos fagos foram obtidas em quatro unidades de processamento de queijo de Coalho, sendo duas artesanais e duas industriais, localizadas no Estado do Ceará. Para o isolamento dos bacteriófagos, foi empregado o teste de lise celular (spot), enquanto que a resistência das culturas aos fagos foi avaliada pelos testes de capacidade de produção de ácido e avaliação da turbidez. As cepas avaliadas foram resistentes aos bacteriófagos provenientes das unidades de processamento de queijo de Coalho e aos bacteriófagos da Coleção do INLAIN. Os resultados obtidos indicaram que as culturas láticas testadas, resistentes aos bacteriófagos, podem ser utilizadas na composição de fermento lático destinado à elaboração de queijo de Coalho, a partir de leite pasteurizado
Supply of cashew bagasse for Haemonchus contortus control in sheep.
Due to the inadequate and non-targeted use of anthelmintics, helminthiasis is a common disease in small ruminants.Boletim de Indústria Animal, v. 74
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