297 research outputs found
The Effect of flashing in reducing the tonal range of a transparency for photomechanical reproduction
Photographic processing and lithographic printing reproduction are two different processes. In photography, the transparency reproduces the original scene in continuous tone. Whereas, in lithographic printing, the reproduction is a result of an all-or-nothing process. A transparency may have a tonal range that exceeds the range that can be reproduced in lithographic printing. So tone compression is performed on transparencies that exceed the tonal range for printing. Avoiding tone compression during lithographic production results in considerable savings in cost and time. One of the methods to reduce tonal range is for the photographer to understand the relationship between emulsion flashing and the tonal range of transparencies. Flashing is the process of projecting nonimage white light to the film emulsion either before or after exposure, but prior to processing. This study investigated the relationship between flashing and exposure for a transparency which would reduce its tonal range and make it suitable for printing. The hypotheses under investigation were: (1) it is possible to flash Ektachrome transparency film by a predetermined amount of light to produce a desired reduction in the tonal range of a transparency, making it more acceptable to the printing range of lithographic printing when using coated paper; (2) the post-flashing technique produces the most acceptable result in achieving the desired tonal range as compared to the pre-flashing technique; (3) the flashing technique produces the same result in a transparency as the image prepared by the use of adjusting the lighting ratio in measured photography. An experimental investigation was conducted. A setup consisting of standard scales was photographed at various exposures and different degrees of flashing. The photography was performed using a 4X5 camera. The setup was illuminated at 45 angles by means of two strobe lights. Exposure was controlled by altering the aperture opening of the lens or fstop. The degree of flashing was determined by pre-exposing or post-exposing the Ektachrome transparency film emulsion to non-image white light through sheets of parchment paper placed at a distance of three inches from the camera lens. The amount of light that could reach the lens during flashing was controlled by varying the number of sheets of parchment paper. Thirty-two transparencies were photographed. The transparencies were processed by E-6 process. The tonal ranges of the transparencies were measured by means of a transmission densitometer. A visual test was conducted to determine the visual appeal of the transparencies by professionals in the field of photography and printing. The outcome of the experimental investigation showed that the tonal range of a transparency is reduced when the film emulsion is flashed. The results suggest that preflashing by an amount of a little over one-third of the light required for normal exposure and then exposing the film to the subject or setup at one and a half stop below the normal exposure produces transparencies that have a tonal range within the limits of lithographic printing and that are visually appealing. It was also shown that pre-flashing the film had a greater effect on reducing the tonal range than post-flashing. Moreover, the flashing technique was compared with methods used to reduce the tonal range by adjusting the lighting ratio. Based on these results, the first hypothesis was confirmed, the second was rejected, and the third was qualitatively accepte
Use of Spineless Cactus (Opuntia ficus indica f. inermis) for Dairy Goats and Growing Kids: Impacts on Milk Production, Kid's Growth, and Meat Quality
The objective of this study was to determine the effect of spineless cactus incorporation in food of dairy goats and growing kids on milk production and composition and on kid's growth and meat characteristics. Two experiments were conducted on Tunisian local goats. In the first, 30 females were divided into two groups; goats of Control group were reared on grazing pasture receiving indoor 0.5 kg of hay and 0.4 kg of concentrate. Goats for the second group (Cac-FL) were kept in feedlot and fed cactus ad libitum more 0.5 kg of hay and 0.4 kg of concentrate. In the second experiment, 14 kids were divided into 2 groups receiving 600 g of hay. The Control group received ad libitum a concentrate containing 130 g crude protein (CP) per kg of dry matter. The second group received cactus ad-libitum plus the half concentrate quantity of control one with 260 g CP/kg DM (Cactus). The daily milk production averaged 485 ml for Control group and 407 ml for Cac-FL one. The milk fat content was significantly higher for Control than Cac-FL group. In the second experiment, animals in Control and Cactus groups had similar growth rate. Carcass fat was significantly lower in Cactus than in the Control group. Cactus in the diet was associated with more C18:2 and conjugated linoleic acid as well as a higher proportion of PUFA than Control ones
Analisis PDRB, Inflasi, Upah Minimum Provinsi, Dan Angka Melek Huruf Terhadap Tingkat Pengangguran Terbuka Di Provinsi Jawa Tengah Tahun 1990-2011
This study aim to analyze factors which having an effect to open-unemployment level in Central Java Province at 1990 to 2011. Ordinary least squares (OLS) will be used as regression model with the dependent variable, open-unemployment level and four independent variables, that are domestic regional gross product, inflation, province minimum wage, and the number of alphabetist. The result show that province minimum wage and the number of alphabetist influential manifestly and significantly to the open-unemployment level. In future, province minimum wage policy need a depth monitoring, so as to persistent over the market equilibrium and the labor welfare guaranteed. The value of province minimum wage which came near 100% indicate the high education quality of society in that region. This case need a special attention from government to create job demand in formal sector to anticipate the castaway potential resource which is the one of development support
Efecto de la incorporación de aceites esenciales de romero sobre la producción de leche de cabra y el crecimiento de los cabritos
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Urate Oxidase Purification by Salting-in Crystallization : Towards an Alternative to Chromatography
Background: Rasburicase (FasturtecH or ElitekH, Sanofi-Aventis), the recombinant form of urate oxidase from Aspergillus flavus, is a therapeutic enzyme used to prevent or decrease the high levels of uric acid in blood that can occur as a result of chemotherapy. It is produced by Sanofi-Aventis and currently purified via several standard steps of chromatography. This work explores the feasibility of replacing one or more chromatography steps in the downstream process by a crystallization step. It compares the efficacy of two crystallization techniques that have proven successful on pure urate oxidase, testing them on impure urate oxidase solutions
PGC-1α controls mitochondrial biogenesis and dynamics in lead-induced neurotoxicity
Due to its role in regulation of mitochondrial function, PGC1α is emerging as an important player in ageing and neurodegenerative disorders. PGC1α exerts its neuroprotective effects by promoting mitochondrial biogenesis (MB) and functioning. However, the precise regulatory role of PGC1α in the control of mitochondrial dynamics (MD) and neurotoxicity is still unknown. Here we elucidate the role of PGC1α in vitro and in vivo in the regulatory context of MB and MD in response to lead (II) acetate as a relevant model of neurotoxicity. We show that there is an adaptive response (AR) to lead, orchestrated by the BAP31-calcium signalling system operating between the ER and mitochondria. We find that this hormetic response is controlled by a cell-tolerated increase of PGC1α expression, which in turn induces a balanced expression of fusion/fission genes by binding to their promoters and implying its direct role in regulation of MD. However, dysregulation of PGC1α expression through either stable downregulation or overexpression, renders cells more susceptible to lead insult leading to mitochondrial fragmentation and cell death. Our data provide novel evidence that PGC1α expression is a key regulator of MD and the maintenance of tolerated PGC1α expression may offer a promising strategy for neuroprotective therapies.España Ministerio de Economía y Competitividad SAF2012-3902
Cambios en el perfil de ácidos grasos del músculo de Holothuria forskali tras una exposición aguda a mercurio
The present study aimed to document the interaction between mercury (Hg), as a model chemical stressor to an aquatic organism, and Fatty acid (FA) profile in the longitudinal muscle of the sea cucumber Holothuria forskali. To assess the sensitivity of this species to the toxic effects of Hg, young H. forskali were exposed to gradual doses of Hg (40, 80 and160 µg·L-1) for 96 h. The results showed that following Hg exposure, the FA profile of H. forskali corresponded to an increase in the level of saturated fatty acids, and the decrease in the level of monounsaturated and polyunsaturated fatty acids. The most prominent changes in the FA composition were recorded at the lowest dose with noticeable decreases in linoleic, arachidonic and eicosapentaenoic acid levels and an increase of docosahexaenoic acid. The occurrence of a state of oxidative stress induced by Hg contamination was evidenced by the enhanced levels of malondialdehyde, hydrogen peroxide and lipid hydroperoxide. Overall, the low concentration of mercury exerted the most obvious effects on lipid metabolism, suggesting that changes in fatty acid composition may be act as an early biomarker to assess mercury toxicity in this ecologically and economically important species.El presente estudio tuvo como objetivo demostrar la interacción entre el mercurio (Hg), como modelo de estresor químico para el organismo acuático, y el perfil de ácidos grasos (FA) en el músculo longitudinal del pepino de mar Holothuria forskali. Para evaluar la sensibilidad de esta especie a los efectos tóxicos del Hg, los juveniles de H. forskali fueron expuestos a dosis graduales de Hg (40, 80 y 160 µg·L-1) durante 96 h. Los resultados mostraron que después de la exposición al Hg, el perfil de FA de H. forskali respondió con una tendencia direccional anclada por el aumento en el nivel de ácidos grasos saturados y la disminución en el nivel de ácidos grasos monoinsaturados y poliinsaturados. Los cambios más prominentes en la composición de AG se registraron a la dosis más baja con una disminución notable en los niveles de ácido linoleico, araquidónico y eicosapentaenoico frente a un aumento de ácido docosahexaenoico. La aparición de un estado de estrés oxidativo inducido por la contaminación con Hg se puso de manifiesto por el aumento en los niveles de malondialdehído, peróxido de hidrógeno e hidroperóxido de lípidos. En general, la concentración más baja de mercurio ejerció efectos más obvios sobre el metabolismo de los lípidos, lo que sugiere que los cambios en la composición de los ácidos grasos pueden actuar como un biomarcador anterior para evaluar la toxicidad del mercurio en esta especie de importancia ecológica y económica
OBSERVATION OF AN ISOKINETIC TEMPERATURE AND COMPENSATION EFFECT FOR HIGH TEMPERATURE CRUDE OIL FOULING
The initial fouling rates of four crude oils were determined at a nominal bulk temperature of 315 °C, an initial heated wall shear stress of 13 Pa, and initial surface temperatures between 375 and 445 °C. These initial fouling rates ranged from 1.3(10-6) to 7.8(10-5) m2 K/kJ. Corresponding Arrhenius plots were linear with the initial fouling rates passing through an isokinetic temperature of 407.5 °C. A plot of the natural logarithm of the preexponential factors (7.6(104) – 5.2(1015) m2 K/kJ) versus the apparent activation energies (128 – 269 kJ/mol) was also linear, confirming the validity of the isokinetic temperature and the presence of the compensation effect. Below the isokinetic temperature, the relative fouling rates were Crude Oil C \u3e Crude Oil A \u3e Crude Oil D \u3e Crude Oil B; above the isokinetic temperature, the relative fouling rates were reversed (Crude Oil B \u3e Crude Oil D \u3e Crude Oil A \u3e Crude Oil C). Chemical characterization of a fouling deposit suggested that the dominant fouling mechanism at these conditions was coking with significant contributions from sedimentation (iron sulfide) and corrosion (~340 μm/yr) of the 304 stainless steel test material
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