257 research outputs found
Caracterización de cepas de Bacillus thuringiensis berliner y actividad biológica hacia Spodoptera frugiperda (J. E. Smith) (Lepidoptera: noctuidae) y Anticarsia gemmatalis hübner (Lepidoptera: noctuidae).
RESUMEN: Se realizó la caracterización de nueve cepas cubanas de Bacillus thuringiensis según la morfología del cristal, la determinación del patrón de proteínas Cry y la actividad biológica frente a los insectos lepidópteros Spodoptera frugiperda y Anticarsia gemmatalis. Se observó la típica morfología bipiramidal en todas las cepas, y además la presencia de inclusiones cúbicas. El patrón de proteínas Cry obtenido correspondió con el de la cepa estándar internacional de B. thuringiensis var. kurstaki cepa HD1, en el que se observan dos bandas bien definidas correspondientes a la proteína Cry 1 (130 kDa) y Cry 2 (70 kDa). En la evaluación de la actividad biológica las cepas LBT 4 y LBT 7 causaron el 100% de mortalidad frente a S. frugiperda, mientras que las LBT 4, LBT 7, LBT 13 y LBT 47 provocaron el 100% de mortalidad para A. gemmatalis. abstract: This study describes the characterization of nine Cuban Bacillus thuringiensis strains based on crystal morphology, SDS polyacrylamide electrophoresis (PAGE) and insecticidal activity against Spodoptera frugiperda and Anticarsia gemmatalis. Ultrastructural analysis of parasporal bodies of the nine strains showed the typical bipyramidal crystal and cubic inclusion partially embedded in the middle of the bipyramidal crystal. The PAGE analysis showed two bands of 130 kDa and 70 kDa belongs to Cry 1 and Cry 2 protein present to HD1 standard strains B. thuringiensis var. kurstaki. The strains LBT 4 and LBT 7 analyzed in this report showed potential as biological insecticide against S. frugiperda and LBT 4, LBT 7, LBT13 and LBT47 strains showed 100% of mortality to Anticarsia gemmatalis
PepT1 mRNA expression levels in sea bream (Sparus aurata) fed different plant protein sources
The expression and regulation of intestinal oligopeptide transporter (PepT)-1 when vegetable
sources are used as a substitute for fish meal in the diet of marine fish has not yet been
explored. In the present study, as part of our ongoing work on elucidating PepT1 gene
expression in relation to different dietary treatments, we have now isolated and deposited in
Genbank database (accession no. GU733710) a cDNA sequence representing the PepT1 in
the sea bream (Sparus aurata). The \u201cde novo\u201d prediction of the three-dimensional structure of
PepT1 protein is presented.
We also analyzed diet-induced changes in the expression of PepT1 mRNA via real-time RTPCR
using the standard curve method. Sea bream were fed for 140 days with one of the
following four diet formulations (43% protein/21% lipid): a control fast growth-promoting
diet (C), and three diets with the same formulation but in which 15% of the fish meal was
substituted by protein concentrates either from lupine (LPC), chick pea (CPC), or green pea
(PPC). Fish fed PPC had significantly (p < 0.05) lower levels of PepT1 transcripts in the
proximal intestine than the controls, whereas PepT1 transcript levels in fish fed LPC or CPC
were not significantly different from the controls. Although growth was similar between fish
fed with different diets during the first 72 days of feeding, growth of the fish fed with PPC
was reduced during the second part of the trial and was significantly (p < 0.05) lower than fish
fed LPC and CPC diets by the end of the experiment. Correlation between these results and
fish growth performances highlights that the intestinal PepT1 mRNA level may serve as a
useful marker of the dietary protein quality and absorption efficiency
Elementos que connotan la gestión de riesgo en emergencias sanitarias
Objetivo: Proponer elementos que desde el enfoque estratégico de la gestión del riesgo puedan ser usados en la toma de decisiones en el proceso de enfrentamiento a emergencias sanitarias.
Métodos: La revisión bibliográfica y documental de los principales autores relacionados con el tema; se utilizaron los métodos comparativos, descriptivo-explicativos para el análisis y valoraciones, y a través del análisis causal y el matricial se proponen los elementos que connotan la gestión de riesgo.
Resultado: La propuesta de elementos que desde el enfoque estratégico de la gestión del riesgo pueden ser utilizados en el proceso de toma de decisión en emergencias sanitarias.
Conclusiones: En la medida que la pandemia se propaga por el mundo y en el país, su connotación como crisis sanitaria, económica y social se hace más evidente, con dimensiones y duración de sus efectos difíciles de cuantificar y predecir lo que obliga al perfeccionamiento de protocolos para su enfrentamiento. La concepción estratégica de la gestión de riesgos para el enfrentamiento de la emergencia sanitaria se convierte en una plataforma de acción válida para promover vías para la identificación del peligro, potenciar la comunicación y percepción del riesgo así como el desarrollo de la gestión de vulnerabilidades, que pueden además convertirse en acciones para reforzar el enfrentamiento a la pandemia. Estas acciones deben favorecer el fortalecimiento de la capacidad de respuesta, elevando la innovación y transferencia de tecnologías, para reducir las vulnerabilidades
Elementos que connotan la gestión de riesgo en emergencias sanitarias
Objetivo: Proponer elementos que desde el enfoque estratégico de la gestión del riesgo puedan ser usados en la toma de decisiones en el proceso de enfrentamiento a emergencias sanitarias.
Métodos: La revisión bibliográfica y documental de los principales autores relacionados con el tema; se utilizaron los métodos comparativos, descriptivo-explicativos para el análisis y valoraciones, y a través del análisis causal y el matricial se proponen los elementos que connotan la gestión de riesgo.
Resultado: La propuesta de elementos que desde el enfoque estratégico de la gestión del riesgo pueden ser utilizados en el proceso de toma de decisión en emergencias sanitarias.
Conclusiones: En la medida que la pandemia se propaga por el mundo y en el país, su connotación como crisis sanitaria, económica y social se hace más evidente, con dimensiones y duración de sus efectos difíciles de cuantificar y predecir lo que obliga al
perfeccionamiento de protocolos para su enfrentamiento. La concepción estratégica de la gestión de riesgos para el enfrentamiento de la emergencia sanitaria se convierte en una plataforma de acción válida para promover vías para la identificación del peligro, potenciar la comunicación y percepción del riesgo así como el desarrollo de la gestión de vulnerabilidades, que pueden además convertirse en acciones para reforzar el enfrentamiento a la pandemia. Estas acciones deben favorecer el fortalecimiento de la capacidad de respuesta, elevando la innovación y transferencia de tecnologías, para reducir las vulnerabilidades
Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: Effects on growth performance, tissue fatty acid profile and lipid metabolism
The aim of this study was to evaluate the effects of increasing dietary arachidonic acid (ARA) levels (from 1 up to 6 % of total fatty acids) on European sea bass (Dicentrarchus labrax) juveniles growth performance, tissue fatty acid profile, liver morphology as well as long chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, triglyceride and cholesterol synthesis and lipid transport. A diet with total fish oil (FO) replacement and defatted fish meal (FM) containing a 0.1 g ARA g-1 diet was added to the experimental design as a negative control diet. Dietary ARA inclusion levels below 0.2 g ARA g-1 diet significantly worsened growth even only 30 days after the start of the feeding trial, whereas dietary ARA had no effect on fish survival. Liver, muscle and whole body fatty acid profile mainly reflected dietary contents and ARA content increased accordingly with ARA dietary levels. Tissue eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels were positively correlated among them. Hepatic lipid vacuolization increased with reduced dietary ARA levels. Expressions of fatty acyl desaturase 2 and 3-hydroxy-3-methylglutaryl-coenzyme genes were up-regulated in fish fed the negative control diet compared to the rest of the dietary treatments denoting the influence of ARA on lipid metabolism. Results obtained highlight the need to include adequate n-6 levels and not only n-3 LC-PUFA levels in European sea bass diets. Keywords: Dicentrarchus labrax, arachidonic acid, growth performance, tissue fatty acid profile, lipid metabolis
A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms
The merger-driven evolution of massive galaxies
We explore the rate and impact of galaxy mergers on the massive galaxy
population using the amplitude of the two-point correlation function on small
scales for M > 5e10 M_sun galaxies from the COSMOS and COMBO-17 surveys. Using
a pair fraction derived from the Sloan Digital Sky Survey as a low-redshift
benchmark, the large survey area at intermediate redshifts allows us to
determine the evolution of the close pair fraction with unprecedented accuracy
for a mass-selected sample: we find that the fraction of galaxies more massive
than 5e10M_sun in pairs separated by less than 30 kpc in 3D space evolves as
F(z) = (0.0130+/-0.0019)x(1+z)^1.21+/-0.25 between z = 0 and z = 1.2. Assuming
a merger time scale of 0.5 Gyrs, the inferred merger rate is such that galaxies
with mass in excess of 1e11 M_sun have undergone, on average, 0.5 (0.7) mergers
involving progenitor galaxies both more massive than 5e10 M_sun since z = 0.6
(1.2). We also study the number density evolution of massive red sequence
galaxies using published luminosity functions and constraints on the M/L
evolution from the fundamental plane. Moreover, we demonstrate that the
measured merger rate of massive galaxies is sufficient to explain this observed
number density evolution in massive red sequence galaxies since z = 1.Comment: Accepted in Ap
Exploring the Impact of Galaxy Interactions over Seven Billion Years with CAS
We explore galaxy assembly over the last seven billion years by
characterizing "normal" galaxies along the Hubble sequence, against strongly
disturbed merging/interacting galaxies with the widely used CAS system of
concentration (C), asymmetry (A), and 'clumpiness' (S) parameters, as well as
visual classification. We analyze Hubble Space Telescope (HST) ACS images of
~4000 intermediate and high mass (> 10^9 solar masses) galaxies from the GEMS
survey, one of the largest HST surveys conducted to date in two filters. We
explore the effectiveness of the CAS criteria [A>S and A>~0.35] in separating
normal and strongly disturbed galaxies at different redshifts, and quantify the
recovery and contamination rate. We also compare the average star formation
rate and the cosmic star formation rate density as a function of redshift
between normal and interacting systems identified by CAS.Comment: ASP conference proceedings of 2007 Bash Symposium. Latex with
asp2006.sty. 4 pages, 4 figure
Characterization of Bacillus thuringiensis strains under the umbrella of a Brazil-Cuba cooperation on bioinsecticides.
Estudo de fraturas nos taludes de corte, em rocha vulcânica, ao longo da BR 158, Santa Maria, RS
Weathering processes and jointing degree are the conditioning factors for rock falI.The fractured volcanic lithologies from Santa Maria, RS, Brazil, were studied along the BR 158 road. Data was gathered through the Scanline method from BRADY & BROWN (1985) and analyzed by vector statistics.Six main jointing groups were defined, associated to rock cooling and shrinking. Main attitudes are: Group 1: 348;83; Group 2: 174;82; Group 3: 85;76; Group 4: 265;75; Group 5: 300;42 and Group 6: 121 ;53.Os processos de alteração e o grau de faturamento das rochas são fatores condicionantes à ocorrência de queda de blocos. Desse modo, estudou-se as características dos fraturamentos das litologias vulcânicas junto a subida da serra, BR 158, município de Santa Maria, RS.Para a aquisição de dados, utilizou-se o método da Scanline de BRADY & BROWN (1985). Os dados obtidos foram analisados por meio de estatística vetorial.Os principais grupos de fraturas definidos, associam-se com o resfriamento da rocha e estão representados pelas atitudes médias: Grupo 1: 348;83; Grupo 2: 174;82; Grupo 3: 85;86; Grupo 4: 265; 75; Grupo 5: 300;42 e Grupo 6: 121; 53
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