338 research outputs found

    Estimation in the Birnbaum-Saunders distribution based on scale-mixture of normals and the EM-algorithm

    Get PDF
    Scale mixtures of normal (SMN) distributions are used for modeling symmetric data. Members of this family have appealing properties such as robust estimates, easy number generation, and efficient computation of the ML estimates via the EM-algorithm. The Birnbaum-Saunders (BS) distribution is a positively skewed model that is related to the normal distribution and has received considerable attention. We introduce a type of BS distributions based on SMN models, produce a lifetime analysis, develop the EM-algorithm for ML estimation of parameters, and illustrate the obtained results with real data showing the robustness of the estimation procedure.Peer Reviewe

    Influences of thermal environment on fish growth

    Get PDF
    Indexación: Scopus.Thermoregulation in ectothermic animals is influenced by the ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown whether physiological and/or metabolic traits are impacted by modifications to the thermal environment. Our research provides key evidence that fish ectotherms are highly influenced by thermal variability during development, which leads to important modifications at several metabolic levels (e.g., growth trajectories, microstructural alterations, muscle injuries, and molecular mechanisms). In Atlantic salmon (Salmo salar), a wide thermal range (ΔT 6.4°C) during development (posthatch larvae to juveniles) was associated with increases in key thermal performance measures for survival and growth trajectory. Other metabolic traits were also significantly influenced, such as size, muscle cellularity, and molecular growth regulators possibly affected by adaptive processes. In contrast, a restricted thermal range (ΔT 1.4°C) was detrimental to growth, survival, and cellular microstructure as muscle growth could not keep pace with increased metabolic demands. These findings provide a possible basic explanation for the effects of thermal environment during growth. In conclusion, our results highlight the key role of thermal range amplitude on survival and on interactions with major metabolism-regulating processes that have positive adaptive effects for organisms.http://onlinelibrary.wiley.com/doi/10.1002/ece3.3239/ful

    Source gases: Concentrations, emissions, and trends

    Get PDF
    Source gases are defined as those gases that influence levels of stratospheric ozone (O3) by transporting species containing halogen, hydrogen, and nitrogen to the stratosphere. Examples are the CFC's, methane (CH4), and nitrous oxide (N2O). Other source gases that also come under consideration in an atmospheric O3 context are those that are involved in the O3 or hydroxyl (OH) radical chemistry of the troposphere. Examples are CH4, carbon monoxide (CO), and nonmethane hydrocarbons (NMHC's). Most of the source gases, along with carbon dioxide (CO2) and water vapor (H2O), are climatically significant and thus affect stratospheric O3 levels by their influence on stratospheric temperatures. Carbonyl sulphide (COS) could affect stratospheric O3 through maintenance of the stratospheric sulphate aerosol layer, which may be involved in heterogeneous chlorine-catalyzed O3 destruction. The previous reviews of trends and emissions of source gases, either from the context of their influence on atmospheric O3 or global climate change, are updated. The current global abundances and concentration trends of the trace gases are given in tabular format

    Estimation in the Birnbaum-Saunders distribution based on scale-mixture of normals and the EM-algorithm

    Get PDF
    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Scale mixtures of normal (SMN) distributions are used for modeling symmetric data. Members of this family have appealing properties such as robust estimates, easy number generation, and efficient computation of the ML estimates via the EM-algorithm. The Birnbaum-Saunders (BS) distribution is a positively skewed model that is related to the normal distribution and has received considerable attention. We introduce a type of BS distributions based on SMN models, produce a lifetime analysis, develop the EM-algorithm for ML estimation of parameters, and illustrate the obtained results with real data showing the robustness of the estimation procedure.332171191Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FONDECYT [1080326, 1090265]DIPUV [29-2006]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FONDECYT [1080326, 1090265]DIPUV [29-2006

    Produção de inóculo de Trichoderma viride para o controle da armilariose em Pinus spp.

    Get PDF
    Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso

    Characterization of \u3ci\u3eNeofabraea actinidiae\u3c/i\u3e and \u3ci\u3eN. brasiliensis\u3c/i\u3e as causal agents of apple bull’s-eye rot in southern Brazil

    Get PDF
    The causal agents of apple bull’s-eye rot in southern Brazil have recently been described as Neofabraea actinidiae and N. brasiliensis. Isolates of both species were evaluated for response of mycelial growth index (MGI) to different temperatures, enzyme production, mycelial growth inhibition and effective concentrations (EC50 and EC100) of the fungicides triflumizole, pyrimethanil and thiophanate methyl, as well as aggressiveness on fruits of ‘Fuji’ hybrid and ‘Pink Lady’. There was significantly lower mycelium growth in N. brasiliensis compared with N. actinidiae at all temperatures tested. Neither species grew at 3 and 32°C. There were minor differences in production of enzymes in the two species, with all N. brasiliensis isolates showing no production of pectolyase at pH 7. The lowest EC50 and EC100 values were observed with thiophanate methyl. In general, ‘Fuji’ fruits were more susceptible to Neofabraea infection and had larger lesions, while N. brasiliensis isolates showed greater aggressiveness on ‘Fuji’ hybrid and ‘Pink lady’ fruits compared with N. actinidiae. Dans le sud du Brésil, les agents causaux du chancre gloésporien de la pomme ont récemment été décrits comme étant Neofabraea actinidiae et N. brasiliensis. Des isolats des deux espèces ont été évalués en fonction de la réaction de l’indice de croissance mycélienne à différentes températures, de la production enzymatique, de l’inhibition de la croissance mycélienne et des concentrations efficaces (CE50 et CE100) des fongicides triflumizole, pyriméthanil et triophanate méthyle, ainsi qu’en fonction de leur agressivité à l’égard de la pomme hybride Fuji et de la Pink Lady. La croissance mycélienne chez N. brasiliensis était considérablement plus faible que chez N. actinidiae, et ce, à toutes les températures testées. Aucune espèce ne s’est développée à 3 ou à 32°C. Chez les deux espèces, il y a eu de petites différences quant à la production enzymatique, tous les isolats de N. brasiliensis n’affichant aucune production de pectolyase à pH 7. Les plus faibles valeurs de CE50 et de CE100 observées ont été celles du triophanate méthyle. Dans l’ensemble, les Fuji étaient plus sujettes à l’infection causée par Neofabraea et affichaient des lésions plus étendues, tandis que les isolats de N. brasiliensis étaient plus agressifs à l’égard de l’hybride Fuji et de la Pink Lady que ceux de N. actinidiae

    Characterization of \u3ci\u3eNeofabraea actinidiae\u3c/i\u3e and \u3ci\u3eN. brasiliensis\u3c/i\u3e as causal agents of apple bull’s-eye rot in southern Brazil

    Get PDF
    The causal agents of apple bull’s-eye rot in southern Brazil have recently been described as Neofabraea actinidiae and N. brasiliensis. Isolates of both species were evaluated for response of mycelial growth index (MGI) to different temperatures, enzyme production, mycelial growth inhibition and effective concentrations (EC50 and EC100) of the fungicides triflumizole, pyrimethanil and thiophanate methyl, as well as aggressiveness on fruits of ‘Fuji’ hybrid and ‘Pink Lady’. There was significantly lower mycelium growth in N. brasiliensis compared with N. actinidiae at all temperatures tested. Neither species grew at 3 and 32°C. There were minor differences in production of enzymes in the two species, with all N. brasiliensis isolates showing no production of pectolyase at pH 7. The lowest EC50 and EC100 values were observed with thiophanate methyl. In general, ‘Fuji’ fruits were more susceptible to Neofabraea infection and had larger lesions, while N. brasiliensis isolates showed greater aggressiveness on ‘Fuji’ hybrid and ‘Pink lady’ fruits compared with N. actinidiae. Dans le sud du Brésil, les agents causaux du chancre gloésporien de la pomme ont récemment été décrits comme étant Neofabraea actinidiae et N. brasiliensis. Des isolats des deux espèces ont été évalués en fonction de la réaction de l’indice de croissance mycélienne à différentes températures, de la production enzymatique, de l’inhibition de la croissance mycélienne et des concentrations efficaces (CE50 et CE100) des fongicides triflumizole, pyriméthanil et triophanate méthyle, ainsi qu’en fonction de leur agressivité à l’égard de la pomme hybride Fuji et de la Pink Lady. La croissance mycélienne chez N. brasiliensis était considérablement plus faible que chez N. actinidiae, et ce, à toutes les températures testées. Aucune espèce ne s’est développée à 3 ou à 32°C. Chez les deux espèces, il y a eu de petites différences quant à la production enzymatique, tous les isolats de N. brasiliensis n’affichant aucune production de pectolyase à pH 7. Les plus faibles valeurs de CE50 et de CE100 observées ont été celles du triophanate méthyle. Dans l’ensemble, les Fuji étaient plus sujettes à l’infection causée par Neofabraea et affichaient des lésions plus étendues, tandis que les isolats de N. brasiliensis étaient plus agressifs à l’égard de l’hybride Fuji et de la Pink Lady que ceux de N. actinidiae

    The Millimeter Astronomy Legacy Team 90 GHz (MALT90) Pilot Survey

    Full text link
    We describe a pilot survey conducted with the Mopra 22-m radio telescope in preparation for the Millimeter Astronomy Legacy Team Survey at 90 GHz (MALT90). We identified 182 candidate dense molecular clumps using six different selection criteria and mapped each source simultaneously in 16 different lines near 90 GHz. We present a summary of the data and describe how the results of the pilot survey shaped the design of the larger MALT90 survey. We motivate our selection of target sources for the main survey based on the pilot detection rates and demonstrate the value of mapping in multiple lines simultaneously at high spectral resolution.Comment: Accepted to ApJS. 23 pages and 16 figures. Full resolution version with an appendix showing all the data (12.1 MB) is available at http://malt90.bu.edu/publications/Foster_2011_Malt90Pilot.pd
    • …
    corecore