988 resultados para Active material
Resumo:
The main goal of this paper is to obtain a granular material formulated with Municipal Solid Waste Incinerarion (MSWI) bottom ash (BA) and air pollution control (APC) ash to be used as secondary building material. Previously, an optimum concrete mixture using both MSWI residues as aggregates was formulated. A compromise between the environmental behaviour and the economy of the process was considered. Unconfined compressive strength and abrasion resistance values were measured in order to evaluate the mechanical properties. From these results, the granular mixture was not suited for certain applications owing to the high BA/APC content and low cement percentages used to reduce the costs of the final product. Nevertheless, the leaching test performed showed that the concentrations of all heavy metals were below the limits established by the current Catalan legislation for their reutilization. Therefore, the material studied might be mainly used in embankments, where high mechanical properties are not needed and environmental safety is assured.
Resumo:
Background: Microsporum canis is a dermatophyte responsible for cutaneous superficial mycoses in domestic carnivores and humans. The pathogenesis of dermatophytoses, including M. canis infections, remains poorly understood. Secreted proteases including members of the subtilisin family are thought to be involved in the infection process. In particular the subtilisin Sub6 could represent a major virulence factor.Objective: The aim of this work was to (i) isolate the M. canis SUB6 genomic DNA and cDNA (ii) produce Sub6 as a recombinant protease (rSub6) and (iii) produce a specific anti-Sub6 polyclonal serum. Material and methods: Genomic SUB6 was amplified by PCR using specific primers and M. canis IHEM 21239 DNA as a target. The SUB6 cDNA was obtained by reverse transcriptase (RT)-PCR using total RNA extracted from the same M. canis strain grown in liquid medium containing feline keratin as unique nitrogen source. Both SUB6 cDNA and genomic DNA were sequenced. The SUB6 cDNA was cloned in pPICZA to produce recombinant Sub6 (rSub6) in Pichia pastoris KM71. This protease rSub6 was produced in methanol medium at a yield of 30 mg ml)1 and purified by anion exchange chromatography using a DEAE-sepharose column. Polyclonal antibodies against purified rSub6 were produced in a rabbit using a standard immunization procedure with saponin as the adjuvant. Seventy days after the first immunization, serum was collected and IgG were purified by affinity chromatography.Results: The coding sequence for M. canis SUB6 from genomic DNA contains 1410 bp and 3 introns, while the cDNA contains a 1221 bp open reading frame. Deduced amino acid sequence analysis revealed that Sub6 is synthesized as a 406 amino acids preproprotein. The predicted catalytic domain has 286 amino acids, a molecular mass of 29.1 kDa and five potential N-glycosylation sites. SDS-PAGE of rSub6 revealed a single polypeptide chain with an apparent molecular mass of 37 kDa. Purified rabbit IgG were shown to be specific for Sub6 using ELISA.Conclusion: We have characterized for the first time Sub6 from a dermatophyte species as a recombinant secreted active enzyme and purified it until homogeneity. Active rSub6 and Sub6 specific antiserum will be used to further study the role of M. canis Sub6 protease in pathogenesis, notably the pattern of in vivo Sub6 secretion in different host species.
Resumo:
Mixture materials, mix design, and pavement construction are not isolated steps in the concrete paving process. Each affects the other in ways that determine overall pavement quality and long-term performance. However, equipment and procedures commonly used to test concrete materials and concrete pavements have not changed in decades, leaving gaps in our ability to understand and control the factors that determine concrete durability. The concrete paving community needs tests that will adequately characterize the materials, predict interactions, and monitor the properties of the concrete. The overall objectives of this study are (1) to evaluate conventional and new methods for testing concrete and concrete materials to prevent material and construction problems that could lead to premature concrete pavement distress and (2) to examine and refine a suite of tests that can accurately evaluate concrete pavement properties. The project included three phases. In Phase I, the research team contacted each of 16 participating states to gather information about concrete and concrete material tests. A preliminary suite of tests to ensure long-term pavement performance was developed. The tests were selected to provide useful and easy-to-interpret results that can be performed reasonably and routinely in terms of time, expertise, training, and cost. The tests examine concrete pavement properties in five focal areas critical to the long life and durability of concrete pavements: (1) workability, (2) strength development, (3) air system, (4) permeability, and (5) shrinkage. The tests were relevant at three stages in the concrete paving process: mix design, preconstruction verification, and construction quality control. In Phase II, the research team conducted field testing in each participating state to evaluate the preliminary suite of tests and demonstrate the testing technologies and procedures using local materials. A Mobile Concrete Research Lab was designed and equipped to facilitate the demonstrations. This report documents the results of the 16 state projects. Phase III refined and finalized lab and field tests based on state project test data. The results of the overall project are detailed herein. The final suite of tests is detailed in the accompanying testing guide.
Resumo:
It is known that post-movement beta synchronization (PMBS) is involved both in active inhibition and in sensory reafferences processes. The aim of this study was examine the temporal and spatial dynamics of the PMBS involved during multi-limb coordination task. We investigated post-switching beta synchronization (assigned PMBS) using time-frequency and source estimations analyzes. Participants (n = 17) initiated an auditory-paced bimanual tapping. After a 1500 ms preparatory period, an imperative stimulus required to either selectively stop the left while maintaining the right unimanual tapping (Switch condition: SWIT) or to continue the bimanual tapping (Continue condition: CONT). PMBS significantly increased in SWIT compared to CONT with maximal difference within right central region in broad-band 14âeuro"30 Hz and within left central region in restricted-band 22âeuro"26 Hz. Source estimations localized these effects within right pre-frontal cortex and left parietal cortex, respectively. A negative correlation showed that participants with a low percentage of errors in SWIT had a large PMBS amplitude within right parietal and frontal cortices. This study shows for the first time simultaneous PMBS with distinct functions in different brain regions and frequency ranges. The left parietal PMBS restricted to 22âeuro"26 Hz could reflect the sensory reafferences of the right hand tapping disrupted by the switching. In contrast, the right pre-frontal PMBS in a broad-band 14âeuro"30 Hz is likely reflecting the active inhibition of the left hand stopped. Finally, correlations between behavioral performance and the magnitude of the PMBS suggest that beta oscillations can be viewed as a marker of successful active inhibition.
Resumo:
This letter has been prepared as a consultation to determine some potential health concerns raised by a resident of Spencer from exposure to wire shredder fluff material emitted by Shine Brothers metal salvaging facility in Spencer, Iowa on July 10, 2011 and, a concern regarding the health impacts from the level of noise measured by a resident near the metal salvaging facility.
Resumo:
[spa] La adaptación al EEES ha implicado una reestructuración de los estudios universitarios promoviendo, entre otros, el uso de una evaluación continuada de los aprendizajes y de herramientas docentes virtuales en los nuevos grados. Estos cambios también pueden aplicarse en el posgrado, aunque hasta el momento, son pocas las experiencias al respecto. El presente trabajo muestra la opinión y los resultados obtenidos de los estudiantes de una asignatura de posgrado de un Máster Oficial Universitario URV-UB en el que se llevó a cabo evaluación continuada y se utilizó el Campus Virtual (CV) como herramienta de aprendizaje y participación activa. La aplicación del proyecto (2007PID/UB-14) se llevó a cabo en 4 fases: elaboración del aula, diseño de encuestas dirigidas a los estudiantes para obtener su opinión sobre la evaluación continuada y sus conocimientos en el uso de plataformas virtuales de forma previa al curso, gestión diaria del aula y seguimiento de las actividades propuestas y finalmente, evaluación del proyecto a través de indicadores cualitativos y cuantitativos derivados de las encuestas y de la propia aplicación virtual. Al inicio del curso la mayoría (93,75%) de los estudiantes prefería evaluación continuada y al final de éste el 100% estuvieron de acuerdo con el tipo de evaluación realizado. Respecto al CV, los estudiantes realizaron todas las actividades de autoevaluación voluntarias. La puntuación sobre la utilidad de todos los recursos del aula del CV fue muy elevada, siendo máxima la obtenida por los ejercicios de autoevaluación. En global, los estudiantes otorgaron al aula una puntuación de 8,1 sobre 10.
Resumo:
[spa] La adaptación al EEES ha implicado una reestructuración de los estudios universitarios promoviendo, entre otros, el uso de una evaluación continuada de los aprendizajes y de herramientas docentes virtuales en los nuevos grados. Estos cambios también pueden aplicarse en el posgrado, aunque hasta el momento, son pocas las experiencias al respecto. El presente trabajo muestra la opinión y los resultados obtenidos de los estudiantes de una asignatura de posgrado de un Máster Oficial Universitario URV-UB en el que se llevó a cabo evaluación continuada y se utilizó el Campus Virtual (CV) como herramienta de aprendizaje y participación activa. La aplicación del proyecto (2007PID/UB-14) se llevó a cabo en 4 fases: elaboración del aula, diseño de encuestas dirigidas a los estudiantes para obtener su opinión sobre la evaluación continuada y sus conocimientos en el uso de plataformas virtuales de forma previa al curso, gestión diaria del aula y seguimiento de las actividades propuestas y finalmente, evaluación del proyecto a través de indicadores cualitativos y cuantitativos derivados de las encuestas y de la propia aplicación virtual. Al inicio del curso la mayoría (93,75%) de los estudiantes prefería evaluación continuada y al final de éste el 100% estuvieron de acuerdo con el tipo de evaluación realizado. Respecto al CV, los estudiantes realizaron todas las actividades de autoevaluación voluntarias. La puntuación sobre la utilidad de todos los recursos del aula del CV fue muy elevada, siendo máxima la obtenida por los ejercicios de autoevaluación. En global, los estudiantes otorgaron al aula una puntuación de 8,1 sobre 10.
Resumo:
Protective immunity to Mycobacterium tuberculosis (Mtb) is commonly ascribed to a Th1 profile; however, the involvement of Th17 cells remains to be clarified. Here, we characterized Mtb-specific CD4(+) T cells in blood and bronchoalveolar lavages (BALs) from untreated subjects with either active tuberculosis disease (TB) or latent Mtb infection (LTBI), considered as prototypic models of uncontrolled or controlled infection, respectively. The production of IL-17A, IFN-γ, TNF-α, and IL-2 by Mtb-specific CD4(+) T cells was assessed both directly ex vivo and following in vitro antigen-specific T-cell expansion. Unlike for extracellular bacteria, Mtb-specific CD4(+) T-cell responses lacked immediate ex vivo IL-17A effector function in both LTBI and TB individuals. Furthermore, Mtb-specific Th17 cells were absent in BALs, while extracellular bacteria-specific Th17 cells were identified in gut biopsies of healthy individuals. Interestingly, only Mtb-specific CD4(+) T cells from 50% of LTBI but not from TB subjects acquired the ability to produce IL-17A following Mtb-specific T-cell expansion. Finally, IL-17A acquisition by Mtb-specific CD4(+) T cells correlated with the coexpression of CXCR3 and CCR6, currently associated to Th1 or Th17 profiles, respectively. Our data demonstrate that Mtb-specific Th17 cells are selectively undetectable in peripheral blood and BALs from TB patients.
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Embankment subgrade soils in Iowa are generally rated as fair to poor as construction materials. These soils can exhibit low bearing strength, high volumetric instability, and freeze/thaw or wet/dry durability problems. Cement stabilization offers opportunities to improve these soils conditions. The objective of this study was to develop relationships between soil index properties, unconfined compressive strength and cement content. To achieve this objective, a laboratory study was conducted on 28 granular and non-granular materials obtained from 9 active construction sites in Iowa. The materials consisted of glacial till, loess, and alluvium sand. Type I/II portland cement was used for stabilization. Stabilized and unstabilized specimens were prepared using Iowa State University 2 in. by 2 in. compaction apparatus. Specimens were prepared, cured, and tested for unconfined compressive strength (UCS) with and without vacuum saturation. Percent fines content (F200), AASHTO group index (GI), and Atterberg limits were tested before and after stabilization. The results were analyzed using multi-variate statistical analysis to assess influence of the various soil index properties on post-stabilization material properties. Results indicated that F200, liquid limit, plasticity index, and GI of the materials generally decreased with increasing cement content. The UCS of the stabilized specimens increased with increasing cement content, as expected. The average saturated UCS of the unstabilized materials varied between 0 and 57 psi. The average saturated UCS of stabilized materials varied between 44 and 287 psi at 4% cement content, 108 and 528 psi at t 8% cement content, and 162 and 709 psi at 12% cement content. The UCS of the vacuum saturated specimens was on average 1.5 times lower than that of the unsaturated specimens. Multi-variate statistical regression models are provided in this report to predict F200, plasticity index, GI, and UCS after treatment, as a function of cement content and soil index properties.
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We present a model for mechanical activation of the cardiac tissue depending on the evolution of the transmembrane electrical potential and certain gating/ionic variables that are available in most of electrophysiological descriptions of the cardiac membrane. The basic idea consists in adding to the chosen ionic model one ordinary differential equation for the kinetics of the mechanical activation function. A relevant example illustrates the desired properties of the proposed model, such as delayed muscle contraction and correct magnitude of the muscle fibers' shortening.
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A geophysical and geochemical study has been conducted in a fractured carbonate aquifer located at Combioula in the southwestern Swiss Alps with the objective to detect and characterize hydraulically active fractures along a 260-m-deep borehole. Hydrochemical analyses, borehole diameter, temperature and fluid electrical conductivity logging data were integrated in order to relate electrokinetic self-potential signals to groundwater flow inside the fracture network. The results show a generally good, albeit locally variable correlation of variations of the self-potential signals with variations in temperature, fluid electrical conductivity and borehole diameter. Together with the hydrochemical evidence, which was found to be critical for the interpretation of the self-potential data, these measurements not only made it possible to detect the hydraulically active fractures but also to characterize them as zones of fluid gain or fluid loss. The results complement the available information from the corresponding litholog and illustrate the potential of electrokinetic self-potential signals in conjunction with temperature, fluid electrical conductivity and hydrochemical analyses for the characterization of fractured aquifers, and thus may offer a perspective for an effective quantitative characterization of this increasingly important class of aquifers and geothermal reservoirs.
Resumo:
In anticipation of regulation involving numeric turbidity limit at highway construction sites, research was done into the most appropriate, affordable methods for surface water monitoring. Measuring sediment concentration in streams may be conducted a number of ways. As part of a project funded by the Iowa Department of Transportation, several testing methods were explored to determine the most affordable, appropriate methods for data collection both in the field and in the lab. The primary purpose of the research was to determine the exchangeability of the acrylic transparency tube for water clarity analysis as compared to the turbidimeter.