1,099 research outputs found
Interpolation of geometric structures compatible with a pseudo Riemannian metric
No full textLet (M, g) be a pseudo Riemannian manifold. We consider four geometric structures on M compatible with g: two almost complex and two almost product structures satisfying additionally certain integrability conditions. For instance, if r is paracomplex and symmetric with respect to g, then r induces a pseudo Riemannian product structure on M. Sometimes the integrability condition is expressed by the closedness of an associated two-form: if j is almost complex on M and ω(x, y) = g(jx, y) is symplectic, then M is almost pseudo Kähler. Now, product, complex and symplectic structures on M are trivial examples of generalized (para)complex structures in the sense of Hitchin. We use the latter in order to define the notion of interpolation of geometric structures compatible with g. We also compute the typical fibers of the twistor bundles of the new structures and give examples for M a Lie group with a left invariant metric.Fil: Fernández Culma, Edison Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; ArgentinaFil: Godoy, Yamile Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; ArgentinaFil: Salvai, Marcos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentin
Mitigation of ruminal methane production with enhancing the fermentation by supplementation of different tropical forage legumes
No full textAuthor Contributions
G. Aragadvay-Yungán, M. Barros-Rodríguez, L.T. Ortiz, M.D. Carro, C. C.N. Marcos, and A.Z.M. Salem: designed the experiment, conducted the experiment, data analysis, writing, and review of the manuscript; G. Aragadvay-Yungán C.N. Marcos and L.T. Ortiz: conducted the experiment, performed the laboratory analyses, and wrote the manuscript; G. Aragadvay-Yungán, Abdelfattah Z.M. Salem, and Mona M.M.Y. Eghandour: prepared and revised the manuscript for submission.The aim of this research was to evaluate the influence of forage species adapted to the tropical region of Ecuador on gas production, enteric methane, digestion, and ruminal fermentation. The tree forage evaluated were C. arborea, E. fusca, B. forficata, E. poeppigiana, C. argentea, G. sepium, C. tora, and F. macrophylla. Ruminal fluid of four adult sheep fistulated with permanent cannulas in the rumen was used in the in vitro gas production technique. The in vitro gas production parameters were lower (P < 0.05) in the C. arborea (A = 41.68 mL gas/g DM, c = 0.044%/h and Lag = 1.654 h) and the average gas production rate for B. forficata was 1.017 mL/h (P < 0.05). C. arborea presented higher (P = 0.0001) effective degradation and real DM digestibility (40.461 g/kg and 82.51 mg/g, respectively). With respect to VFA, the highest (P < 0.05) proportion of acetic, propionic, and butyric was observed in C. arborea, G. sepium, and E. poeppigiana (72.52, 23.09, and 7.44 mol/100 mol, respectively) and the lowest (P = 0.0001) ratio: acetic/propionic was observed in G. sepium (2.92 mol/100 mol). The content of NH3-N (mg/L) showed no difference. The lowest (P = 0.0001) methane production was observed in C. arborea (1.23 mL CH4/g DM). The use of forage species of tropical climate rich in secondary metabolites in ruminant diets has the capacity to reduce the gas production and enteric methane; however, this is at the expense of the reduction of the fermentation of organic matter in the rumenDepto. de Producción AnimalFac. de VeterinariaTRUEpu
Infectious salmon anaemia virus (ISAV) isolated from the ISA disease outbreaks in Chile diverged from ISAV isolates from Norway around 1996 and was disseminated around 2005, based on surface glycoprotein gene sequences
No full textBACKGROUND: Infectious salmon anaemia (ISA) virus (ISAV) is a pathogen of marine-farmed Atlantic salmon (Salmo salar); a disease first diagnosed in Norway in 1984. For over 25 years ISAV has caused major disease outbreaks in the Northern hemisphere, and remains an emerging fish pathogen because of the asymptomatic infections in marine wild fish and the potential for emergence of new epidemic strains. ISAV belongs to the family Orthomyxoviridae, together with influenza viruses but is sufficiently different to be assigned to its own genus, Isavirus. The Isavirus genome consists of eight single-stranded RNA species, and the virions have two surface glycoproteins; fusion (F) protein encoded on segment 5 and haemagglutinin-esterase (HE) protein encoded on segment 6. However, comparison between different ISAV isolates is complicated because there is presently no universally accepted nomenclature system for designation of genetic relatedness between ISAV isolates. The first outbreak of ISA in marine-farmed Atlantic salmon in the Southern hemisphere occurred in Chile starting in June 2007. In order to describe the molecular characteristics of the virus so as to understand its origins, how ISAV isolates are maintained and spread, and their virulence characteristics, we conducted a study where the viral sequences were directly amplified, cloned and sequenced from tissue samples collected from several ISA-affected fish on the different fish farms with confirmed or suspected ISA outbreaks in Chile. This paper describes the genetic characterization of a large number of ISAV strains associated with extensive outbreaks in Chile starting in June 2007, and their phylogenetic relationships with selected European and North American isolates that are representative of the genetic diversity of ISAV. RESULTS: RT-PCR for ISAV F and HE glycoprotein genes was performed directly on tissue samples collected from ISA-affected fish on different farms among 14 fish companies in Chile during the ISA outbreaks that started in June 2007. The genes of the F and HE glycoproteins were cloned and sequenced for 51 and 78 new isolates, respectively. An extensive comparative analysis of ISAV F and HE sequence data, including reference isolates sampled from Norway, Faroe Islands, Scotland, USA, and Canada was performed. Based on phylogenetic analysis of concatenated ISAV F and HE genes of 103 individual isolates, the isolates from the ISA outbreaks in Chile grouped in their own cluster of 7 distinct strains within Genotype I (European genotype) of ISAV, with the closest relatedness to Norwegian ISAVs isolated in 1997. The phylogenetic software program, BACKTRACK, estimated the Chile isolates diverged from Norway isolates about 1996 and, therefore, had been present in Chile for some time before the recent outbreaks. Analysis of the deduced F protein sequence showed 43 of 51 Chile isolates with an 11-amino acid insert between 265N and 266Q, with 100% sequence identity with Genotype I ISAV RNA segment 2. Twenty four different HE-HPRs, including HPR0, were detected, with HPR7b making up 79.7%. This is considered a manifestation of ISAV quasispecies HE protein sequence diversity. CONCLUSION: Taken together, these findings suggest that the ISA outbreaks were caused by virus that was already present in Chile that mutated to new strains. This is the first comprehensive report tracing ISAV from Europe to South America.Source type: Electronic(1
DOSE AND MODE OF APPLICATION OF THE WATER-ABSORBENT COPOLYMER ON GROWTH OF BERMUDAGRASS
No full textDOSE AND MODE OF APPLICATION OF THE WATER-ABSORBENT COPOLYMER ON GROWTH OF BERMUDAGRASS LEANDRO JOSÉ GRAVA DE GODOY1; MARCOS RENATO VILLARON XAVIER E BARBOSA2; MARCELO VIEIRA FERRAZ1; LUIS AUGUSTO SAES2 E MARCOS VIEIRA FERRAZ3 1Professor Assistente Doutor do curso de Engenharia Agronômica, Universidade Estadual Paulista, Câmpus Experimental de Registro, Registro, SP, Brasil, [email protected]; [email protected] do curso de Engenharia Agronômica, Universidade Estadual Paulista, Câmpus Experimental de Registro, Registro, SP, Brasil, [email protected]; [email protected]ós-doutorando, Departamento de Horticultura, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Câmpus de Botucatu, SP, Brasil, [email protected]. 1 ABSTRACT The present study aimed to evaluate the effects of water-absorbent copolymer in the growth of Bermudagrass, planted in a sandy substrate and soil medium texture. The treatments consisted of five doses of the copolymer (0, 25, 50, 75 or 100 g m-2), and two application modes (dry and hydrated) in a completely randomized design with five replications. During the experimental period turfs were subjected to a period of 10 days without watering. For the sandy substrate, when subjected to water stress, there was linear increase on dry mater production of clippings (growth) in function doses of water-absorbent copolymer. The major dry mater of roots was achieved by application of the copolymer at a dose of 56 g m-2 hydrated. For the soil medium textured copolymer hydrated in doses 50-54 g m-2 water-absorbent copolymer showed greater production of dry mater of clippings of Bermudagrass cv. Celebration applied in powder and hydrated forms respectively. For medium textured soil this water-absorbent copolymer did not influence the intensity of green color, not the green coverage rate of the turfgrass. The application of hydrated copolymer reduced the dry matter of roots in the soil of medium texture. Keywords: Hydrogel, Cynodon dactylon (L.) Pers, Maintenance, Turfgrass. GODOY, L. J. G.; XAVIER E BARBOS, M. R. V.; FERRAZ, M. V.; SAES, L. A.; FERRAZ, M. V.DOSES E MODOS DE APLICAÇÃO DE COPOLÍMERO HIDROABSORVENTE NO CRESCIMENTO DA GRAMA BERMUDA 2 RESUMO Com o presente estudo, objetivou-se avaliar os efeitos do copolímero hidroabsorvente no crescimento da grama bermuda, plantada em substrato de areia e solos de textura média. Os tratamentos consistiram da aplicação de cinco doses do copolímero (0; 25; 50; 75; 100 g m-2), e dois modos de aplicação (seco e hidratado), num delineamento inteiramente casualizado com cinco repetições. Durante o período experimental as gramas foram submetidas a um período sem irrigação de 10 dias. Para o substrato arenoso quando submetido a estresse hídrico houve efeito linear do copolímero sobre a produção de fitomassa seca de aparas (crescimento). A maior fitomassa de raízes foi alcançada com a aplicação do copolímero na dose de 56 g m-2 de forma hidratada. Já para o solo de textura média o copolímero na forma hidratada nas doses de 50 a 54 g m-2 do copolímero proporcionou maior produção de fitomassa seca de aparas da grama bermuda cv. Celebration aplicados em pó e de forma hidratada, respectivamente. Para o solo de textura média este copolímero não influenciou a intensidade de cor verde, nem a taxa de cobertura verde do gramado. A aplicação do copolímero hidratado reduziu a fitomassa seca das raízes, em solo de textura média. Palavras-Chave: Hidrogel, Cynodon dactylon (L.) Pers, Manutenção, Gramado. </jats:p
Do passeio na avenida à balada no prolonga: sociabilidade no espaço público: o caso da Avenida Getúlio Vargas, Chapecó (SC)
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Antropologia Social, Florianópolis, 2009Esta pesquisa busca compreender as sociabilidades no espaço público da Avenida Getúlio Vargas no município de Chapecó. É resultado de uma pesquisa etnográfica na rua que teve como foco de análise as práticas que delimitam, fragmentam e criam lugares no espaço público chapecoense. São apresentados diferentes contextos de sociabilidade, diferentes cenários que abrigam desde o passeio como uma forma costumeira de uso do espaço público que aparece na parte central da avenida às baladas na rua criadas a partir de práticas de jovens que se reúnem em espaços determinados, criam cenários e pontos de encontro. Estes lugares são constituídos por dinâmicas específicas de sociabilidade, analisadas, nesta dissertação, em torno das relações do ver e ser visto. As diferentes sociabilidades urbanas identificadas na Avenida Getúlio Vargas ressaltam a importância desta enquanto ícone do espaço público da cidade de Chapecó, sendo o envolvente físico e simbólico dessas diferentes sociabilidades. Dos cenários analisados, o prolonga aparece como espaço paradoxal, envolvido simultaneamente por conotações de transgressividade e permissividade. Relações ambíguas que se organizam em termos de coexistência, de simultaneidade e complementaridade, permitindo analisar o espaço público em termos de permanências e descontinuidades.This research focuses on sociability in the public space of Avenida Getúlio Vargas in the municipality of Chapecó. It is a result of ethnographic research in the street that had the focus of analysis practices that define, fragment and create posts in the public space chapecoense. Are presented different social contexts, different scenarios that harbor from the tour - as a form of customary use of public space that appears in central part of the avenue - the ballads in the street - established practices of young people who gather in certain spaces, create scenarios and points of meeting. These places are made of specific dynamics of social, analyzed in this work, around the relations of the "see and be seen". The different urban sociability identified on Avenida Getúlio Vargas emphasized the importance of this as an icon of public space in the city of Chapecó and the surrounding physical and symbolic of different sociability. Of the scenarios examined, the prolonga appears as paradoxical space, surrounded both by connotations of transgressive and permissiveness. Ambiguous relationships that are organized in terms of coexistence, of simultaneity and complementarity, consider allowing the public space in terms of permanence and discontinuities
<i>Arachis</i> spp. accessions included in the present study.
No full text<p>* Collectors: = Ar = A.R. Custodio, Bi = L. B. Bianchetti, Co = L. Coradin, Dc = D. Claure, G = W. C. Gregory, Gd = I. J. Godoy, Ge = M. A. N. Gerin, Gr = A. Gripp, H = R. Hammons, J = L. Jank, K = A. Krapovickas, L = W.R. Langford, Lf = L. G. Faria,Lm = L. Monçato, M = J. P. Moss, Mi = S.T.S.Miotto, Mm = M. Moraes, Oa = O.Ahumada, Of = F. O. Freitas, P = J. R. Pietralli, Pm = R. N. Pittmann, Po = A. Pott, Pz = E. Pizarro, R = V. R. Rao, Rc = R.C.Oliveira, S = C. E. Simpson, Sc = A. Schinini, Sg = A. K. Singh, St = H. T. Stalker, Sv = G. P. Silva, Sz = R. Schultze-Kraft, V = J. F. M. Valls, W = W. L. Werneck, Wi = D. E. Williams.</p><p><i>Arachis</i> spp. accessions included in the present study.</p
First description of clinical presentation of piscine orthoreovirus (PRV) infections in salmonid aquaculture in Chile and identification of a second genotype (Genotype II) of PRV
No full textGenetic analysis and comparative virulence of infectious salmon anemia virus (ISAV) types HPR7a and HPR7b from recent field outbreaks in Chile
No full textBackground:
Infectious salmon anemia (ISA) is a serious disease of marine farmed Atlantic salmon, Salmo salar L. caused by ISA virus (ISAV). ISAV genomic segments 5 and 6 encode surface glycoproteins hemagglutinin-esterase (HE) and F protein important for the pathogenicity of ISAV. In this study, we describe the genetic characteristics and relationship between ISAV-HPR7a and ISAV-HPR7b strains that caused the ISA outbreaks in Chile in 2013 and 2014, respectively, and the evolution of the ISAV clades since 2009 based on segment 5 and 6 sequences.
Methods:
The study material included samples from six ISA cases in Chile. RNA was extracted from salmon tissues and ISAV isolated from cell culture; segments 5 and 6 were amplified by RT-PCR and compared by alignment with ISAV sequences from the GenBank database.
Results
ISAV-HPR7a and ISAV-HPR7b belong to the European Genotype I strains only found in Europe and Chile, and in both cases, show high similarity in segments 5 and 6 with identity between 95–96%. Our data confirm the hypothesis that the original virus was introduced to Chile in 1996. Compared to the 2007 ISAV-HPR7b isolate, the 2014 ISAV-HPR7b does not have an insertion in segment 5 and was associated with low mortality, which suggests that ISAV virulence was attenuated by the absence of the insertion in segment 5. In contrast, the highly virulent ISAV-HPR14 from April 2013 outbreak did not have the insertion in segment 5 either.
Conclusion:
Variability in the ISAV virulence markers supports the quasispecies theory that multiple evolution forces are likely to shape ISAV genetic diversity. Our findings provide evidence of continuing evolution of ISAV in the Chilean aquaculture industry
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