980 resultados para ROMA - HISTORIA - IMPERIO, 30 A.C. 476 D.C.


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effects of temperature and food availability on feeding and egg production of the Arctic copepod Calanus hyperboreus were investigated in Disko Bay, western Greenland, from winter to spring 2009. The abundance of females in the near bottom layer and the egg production of C. hyperboreus prior to the spring bloom document that reproduction relies on lipid stores. The maximum in situ egg production (± SE) of 54 ± 8 eggs female/d was recorded in mid-February at chlorophyll a concentrations below 0.1 µg/l, whereas no egg production was observed in mid-April when the spring bloom developed. After reproduction, the females migrated to the surface layer to exploit the bloom and refill their lipid stores. In 2 laboratory experiments, initiated before and during the spring bloom, mature females were kept with and without food at 5 different temperatures ranging from 0 to 10°C and the fecal pellet and egg production were monitored. Food had a clear effect on fecal pellet production but no effect on egg production, while temperature did not have an effect on egg or fecal pellet production in any of the experiments. Analyses of carbon and lipid content of the females before and after the experiments did not reflect any effect of food or temperature in the pre-bloom experiment, whereas in the bloom experiment a clear positive effect of food was detected in female biochemical profiles. The lack of a temperature response suggests a future warmer ocean could be unfavorable for C. hyperboreus compared to smaller Calanus spp. which are reported to exploit minor temperature elevations for increased egg production.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ausonio de Burdigala (Burdeos) escribe entre los años 379-383 su obra poética titulada Caesares. Esta colección es una biografía de la vida de los emperadores en verso (hexámetro y dístico elegíaco). Caesares no está completa; la obra acaba de repente en el cuarteto dedicado a Heliogábalo. En este trabajo abordamos el género de la colección, examinamos el estilo de Ausonio en varias partes (monósticos y tetrásticos) y destacamos las fuentes (Suetonio, Tácito, Kaisergeschichte, Mario Máximo). Asimismo valoramos las diferentes opiniones que los estudiosos de Ausonio han expresado sobre la parte perdida de esta colección.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

En el presente artículo analizamos los desplazamientos de cultos indígenas hispanos desde distintas áreas de la Península Ibérica hacia los principales lugares de inmigración en Hispania: las áreas mineras y las ciudades. Proponemos que estos grupos de emigrantes rendían culto en su nueva residencia a las deidades que veneraban en sus regiones de procedencia como un medio de preservar su cohesión social y su identidad cultural. La dureza de la vida laboral en las áreas mineras reforzaba la necesidad de fortalecer los lazos culturales.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

En este trabajo hemos examinado comentarios a la traducción al latín del ejercicio de la Fábula de los Progymnasmata de Aftonio para ver cómo afecta la traducción de algunos términos al comentario. Dado que, al traducir de una lengua a otra, difícilmente hay correspondencia exacta, el traductor opta por la solución que estima más adecuada, primando ciertos matices sobre otros y, con frecuencia, llega, incluso, a dotar al término de acepciones en la lengua meta que no existían en la lengua origen. La elección realizada no parece obedecer a otra razón que a preferencias del traductor, pero tiene consecuencias e influye en los comentaristas. Por otra parte, la existencia de un término acuñado no impide que tanto los traductores como los escoliastas creen otros nuevos, tal vez por deseo de mostrar originalidad. Finalmente, la traducción tiene una doble vertiente: de un lado, influye en el entendimiento del concepto y en el comentario, y, de otro, refleja la concepción que de la realidad tiene el traductor.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Las enfermedades raras o huérfano son una problemática que ha tomado mucha importancia en el contexto mundial del presente siglo, estas se han definido como crónicas, de difícil tratamiento de sus síntomas y con baja prevalencia en la población; muchas de estas enfermedades cursan con varios tipos de discapacidad, siendo el objetivo del presente trabajo el enfocarse en aquellas enfermedades raras que cursan con discapacidad intelectual. Para poder profundizar en estas enfermedades se realizó una revisión teórica sobre las enfermedades raras, así como de la discapacidad psíquica y su importancia a nivel mundial y nacional. A partir de estas definiciones, se revisaron en profundidad 3 enfermedades raras que cursan con discapacidad intelectual en el contexto colombiano, como son: el síndrome de Rett, el síndrome de Prader-Willi y el síndrome de X frágil. En cada una de estas enfermedades además se explicaron los tipos de diagnóstico, intervención, prevención, grupos de apoyo y tipos de evaluación que más se usan en el contexto nacional

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Varias investigaciones sobre el café han enfatizado la dimensión económica e histórica para analizarlo. La estructura económica, los precios, la organización de las empresas de acuerdo a la reducción de costos, los procesos políticos y culturales en fin, han sido los articuladores de estos análisis. Sin embargo, el presente trabajo se enfatizó en el análisis de las organizaciones a partir de la antropología empresarial de Bourdieu para abordar el café en Neiva. Cómo las diferentes organizaciones de intermediación interactúan para establecer, garantizar y perpetuar su posición en el mercado del café.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Este documento corresponde al ejercicio preliminar de la línea de investigación en dinámicas territoriales, y es uno de los artículos científicos propuestos como resultado del Proyecto de investigación “Inteligencia territorial para la recuperación de las dinámicas socio-productivas de la subregión de Lengupá”. Por lo tanto, presenta los resultados de la fase exploratoria, correspondiente al diagnóstico regional en el marco de los enfoques teóricos desde los cuales la región es estudiada. A continuación, se presentarán los dos pilares fundamentales de ésta investigación: el territorio y la Inteligencia Territorial. En el caso del territorio, este proceso de investigación parte de un diferenciación previa respecto al lugar y al espacio, debido a que en el territorio se dan relaciones históricas y de poder en una relación dialéctica, entre los atributos ecológicos y culturales, teniendo en cuenta el planteamiento de Sasquet, (2015) cuando menciona que para comprender el territorio es necesario comprender el espacio geográfico, territorialidad humana, en escala subregional y a través del tiempo.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Tras conocer cuatro años de debate (dentro y fuera de La Habana), los borradores de dos puntos de la agenda y presenciar el crecimiento de bandas criminales y/u organizaciones sucesoras del paramilitarismo, de la mano de la expansión de economías ilegales y una polarización creciente (y preocupante por sus características) en torno a la paz y el conflicto social/armado en el país, el presente trabajo pretende analizar a profundidad el carácter y alcance de los discursos emitidos por los negociadores en La Habana.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p+p collisions at a center-of-mass energy of root s = 200 GeV. The data, which cover jet transverse momenta 5 < p(T) < 30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this research was to improve Glucose-6-phosphate dehydrogenase (G6PD) production by Saccharomyces cerevisiae W303-181, which carry the plasmid YEpPGK-G6PD, by varying the following cultivation conditions: pH value (4.8, 5.7 and 6.6); inoculum concentration (0.1, 0.6 and 1.1 g/L) and initial glucose concentration (20.0, 30.0 and 40.0 g/L). The effect of those variables on G6PD production capability was studied by the application of response surface statistical analysis. The results showed that the highest G6PD production (1594.2 U/L), specific activity (1189.7 U/g(cell)) and productivity (45.6 U/L.h) occurred at pH 4.8, inoculum concentration of 0.1 g/L and initial glucose concentration of 20.0 g/L, under agitation of 150 rpm at 30 degrees C after 36 h. In this work, the strain expressed about 21 fold more activity than the wild S. cerevisiae strain, being an attractive and promising new source of this enzyme.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The influence of impeller type and stirring frequency on the performance of a mechanically stirred anaerobic sequencing batch reactor containing immobilized biomass on an inert support (AnSBBR - Anaerobic Sequencing Batch Biofilm Reactor) was evaluated. The biomass was immobilized on polyurethane foam cubes placed in a stainless-steel basket inside a glass cylinder. Each 8-h batch run consisted of three stages: feed (10 min), reaction (460 min) and discharge (10 min) at 30 degrees C. Experiments were performed with four impeller types, i.e., helical, flat-blade, inclined-blade and curved-blade turbines, at stirring frequencies ranging from 100 to 1100 rpm. Synthetic wastewater was used in all experiments with an organic-matter concentration of 530 +/- 37 mg/L measured as chemical oxygen demand (COD). The reactor achieved an organic-matter removal efficiency of around 87% under all investigated conditions. Analysis of the four impeller types and the investigated stirring frequencies showed that mass transfer in the liquid phase was affected not only by the applied stirring frequency but also by the agitation mode imposed by each impeller type. The best reactor performance at all stirring frequencies was obtained when agitation was provided by the flat-blade turbine impeller. (C) 2010 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The removal of sulfate and organic matter was assessed in an ASBR, which treated wastewater containing 500 mg COD L(-1) (3 g COD L(-1) d(-1)) in 8 h-cycles at 30 degrees C. The wastewater was enriched with sulfate at [COD/SO(4)(2-]) ratios of 1.34, 0.67 and 0.34 (8.8,4.5 and 2.2 gSO(4)(2-) L(-1) d(-1)). For each COD/[SO(4)(2-)] ratio fill times used were: 10 min (batch), 3 and 6 h (fed-batch), achieving sulfate reduction of 30%, 72% and 72% (COD/[SO(4)(2-)] of 1.34); 25%, 58% and 55% (COD/[SO(4)(2-)] of 0.67) and 23%, 37% and 27% (COD/[SO(4)(2-)] of 0.34), respectively, and organic matter removal of 87%, 68% and 80% (COD/[SO(4)(2-)] of 1.34); 78%, 75% and 69% (COD/[SO(4)(2-)] of 0.67) and 85%, 84% and 83% (COD/[SO(4)(2-)] of 0.34), respectively. The results showed that fed-batch operation improved sulfate reduction, whereas organic matter removals were similar for batch and fed-batch operation. In addition, increase in sulfate loading in the fed-batch operation improved organic matter removal. (C) 2010 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effect of flow type and rotor speed was investigated in a round-bottom reactor with 5 L useful volume containing 2.0 L of granular biomass. The reactor treated 2.0 L of synthetic wastewater with a concentration of 800 mgCOD/L in 8-h cycles at 30 degrees C. Five impellers, commonly used in biological processes, have been employed to this end, namely: a turbine and a paddle impeller with six-vertical-flat-blades, a turbine and a paddle impeller with six-45 degrees-inclined-flat-blades and a three-blade-helix impeller. Results showed that altering impeller type and rotor speed did not significantly affect system stability and performance. Average organic matter removal efficiency was about 84% for filtered samples, total volatile acids concentration was below 20 mgHAc/L and bicarbonate alkalinity a little less than 400 mgCaCO(3)/L for most of the investigated conditions. However, analysis of the first-order kinetic model constants showed that alteration in rotor speed resulted in an increase in the values of the kinetic constants (for instance, from 0.57 h(-1) at 50 rpm to 0.84 h(-1) at 75 rpm when the paddle impeller with six-45 degrees-inclined-flat-blades was used) and that axial flow in mechanically stirred reactors is preferable over radial-flow when the vertical-flat-blade impeller is compared to the inclined-flat-blade impeller (for instance at 75 rpm, from 0.52 h(-1) with the six-flat-blade-paddle impeller to 0.84 h(-1) with the six-45 degrees-inclined-flat-blade-paddle impeller), demonstrating that there is a rotor speed and an impeller type that maximize solid-liquid mass transfer in the reaction medium. Furthermore, power consumption studies in this reduced reactor volume showed that no high power transfer is required to improve mass transfer (less than 0.6 kW/10(3) m(3)). (C) 2008 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An investigation was performed on the effect of temperature and organic load on the stability and efficiency of a 1.8-L fluidized-bed anaerobic sequencing batch reactor (ASBR), containing granulated biomass. Assays were carried out employing superficial up How velocity of 7 m/h, total cycle length of 6 h and synthetic wastewater volume of 1.3 L per cycle. The fluidized-bed ASH was operated at 15, 20, 25 and 30 degrees C with influent organic matter concentrations of 500 and 1000 mgCOD/L The system showed stability under all conditions and presented filtered samples removal efficiency ranging from 79 to 86%. A first-order kinetic model could be fitted to the experimental values of the organic matter concentration profiles. The specific kinetic parameter values of this model ranged from 0.0435 to 0.2360 L/(gTVS h) at the implemented operation conditions. in addition, from the slope of an Arrhenius plot, the activation energy values were calculated to be 16,729 and 12,673 cal/mol for operation with 500 and 1000 mgCOD/L, respectively. These results show that treatment of synthetic wastewater. with concentration of 500 mgCOD/L, was more sensitive to temperature variations than treatment of the same residue with concentration of 1000 mgCOD/L. Comparing the activation energy value for operation at 500 mgCOD/L with the value obtained by Agibert et al. (S.A. Agibert, M.B. Moreira, S.M. Ratusznei, J.A.D. Rodrigues, M. Zaiat, E. Foresti. Influence of temperature on performance of an ASBBR with circulation applied to treatment of low-strength wastewater. journal of Applied Biochemistry and Biotechnology, 136 (2007) 193-206) in an ASBBR treating the same wastewater at the same concentration, the value obtained in the fluidized-bed ASBR showed to be superior, indicating that treatment of synthetic wastewater in a reactor containing granulated biomass was more sensitive to temperature variations than the treatment using immobilized biomass. (c) 2008 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this work was to analyze the interaction effects between temperature, feed strategy and COD/[SO(4)(2-)] levels, maintaining the same ratio, on sulfate and organic matter removal efficiency from a synthetic wastewater. This work is thus a continuation of Archilha et al. (2010) who studied the effect of feed strategy at 30 degrees C using different COD/[SO] ratios and levels. A 3.7-L anaerobic sequencing batch reactor with recirculation of the liquid phase and which contained immobilized biomass on polyurethane foam (AnSBBR) was used to treat 2.0 L synthetic wastewater in 8 h cycles. The temperatures of 15, 22.5 and 30 degrees C with two feed strategies were assessed: (a) batch and (b) batch followed by fed-batch. In strategy (a) the reactor was fed in 10 min with 2 L wastewater containing sulfate and carbon sources. In strategy (b) 1.2 L wastewater (containing only the sulfate source) was fed during the first 10 min of the cycle and the remaining 0.8 L (containing only the carbon source) in 240 min. Based on COD/[SO(4)(2-)] = 1 and on the organic matter (0.5 and 1.5 gCOD/L) and sulfate (0.5 and 1.5 gSO(4)(2-)/L) concentrations, the sulfate and organic matter loading rates applied were 1.5 and 4.5 g/L.d, i.e., same COD/[SO(4)(2-)] ratio (=1) but different levels (1.5/1.5 and 4.5/4.5 gCOD/gSO(4)(2-)). When reactor feed was 1.5 gCOD/L.d and 1.5 gSO(4)(2-)/L.d, gradual feeding (strategy b) showed to favor sulfate and organic matter removal in the investigated temperature range, indicating improved utilization of the electron donor for sulfate reduction. Sulfate removal efficiencies were 87.9; 86.3 and 84.4%, and organic matter removal efficiencies 95.2; 86.5 and 80.8% at operation temperatures of 30; 22.5 and 15 degrees C, respectively. On the other hand, when feeding was 4.5 gCOD/L.d and 4.5 gSO(4)(2-)/L.d, gradual feeding did not favor sulfate removal, indicating that gradual feeding of the electron donor did not improve sulfate reduction. (C) 2011 Elsevier Ltd. All rights reserved.