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Search Results: 1 - 10 of 220071 matches for " Jara C. "
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Efecto de un surfactante sobre la integridad de espermatozoides ovinos crioconservados
HELLEMANN,C.; JARA,C.;
Archivos de medicina veterinaria , 1997, DOI: 10.4067/S0301-732X1997000100019
Abstract: in order to test the effect of the addition of the commercial surfactant equex stm to tris and na-citrate extenders on the survival of ram semen, four trials using factorial designs were conducted freezing separate ejaculates collected from 2 austral and l border leicester rams. common for all trials was a monophasic dilution at room temperature, with 20% egg-yolk containing extenders split in fractions with 0.5% and without surfactant, packing of extended semen in 0.25 minitüb-straws, an adaptation period at 5°c for 3-4 h, a freezing rate of about 5°c/min performed 10 cm above level of liquid nitrogen, and thawing of straws for 15 seconds in a 40°c water bath. quality criteria for thawed semen were motility index (mi) and normal intact acrosomes (na). with the use of statgraf 5.1, results were submitted to anova and duncan test, complemented with "t"-test (twosam), assuming p < 0.05. in the 1st trial, the comparison of tris-extender (t) vs. 2.9% na-citrate extender (c), mi was significantly lower in c-extenders, specially in c-extender without surfactant, which caused high rates of bent tails indicating osmotic damage. this was not observed in c with surfactant nor in t- fractions. the effect of surfactant on na was significant with both extenders. in the 2nd trial, citrate extender was comparatively modified, adding 0.3% (w/v) sulphanilamide to increase osmolarity and ph. the results were basically the same as in the 1st trial: addition of surfactant gave significantly higher na-rates in tris and citrate extenders and significantly higher mi in both citrate-extenders. in the 3rd trial, designed to compare two concentrations of na-citrate (2.9% vs. 3.1% w/v), and to compare a fast vs. a slow dilution, no differences between extenders nor between fast and slow dilution were found. again, the effect of the surfactant on na and mi was significant. in the 4th trial, conducted mainly to compare fast and slow dilution with tris extender, no difference was found. again th
Efecto de un surfactante sobre la integridad de espermatozoides ovinos crioconservados
C. HELLEMANN,C. JARA
Archivos de medicina veterinaria , 1997,
Abstract: Con el objetivo de comprobar el efecto de la adición de un tensido comercial (Equex STM a diluyentes tris y citrato de Na en la sobrevivencia de semen ovino, se realizaron 4 ensayos con dise o factorial de crioconservación de eyaculados de 2 carneros de raza Austral y un carnero Border Leicester, procesados separadamente. Fue común para todos los ensayos la dilución monofásica rápida a temperatura ambiente, en diluyentes con 20% (v/v) de yema de huevo, divididos en fracciones sin y con 0.5% (v/v) de Equex STM, el empaque en minitubos de 0.25 ml, períodos de adaptación a +5°C de 3 a 4 h, la curva de congelación en vapor de nitrógeno a 10 cm sobre la fase líquida de aproximadamente 5°C/min y la posterior descongelación en agua a 40°C por 15 s. Los criterios de evaluación del semen descongelado fueron el índice de motilidad (IM) y la integridad del borde apical de los acrosomas (AN). Los resultados se sometieron a análisis de varianza, test de Duncan y test de "t" (TWOSAM) del paquete STATGRAF 5.1, asumiendo p <0.05%. La comparación en el 1er. ensayo de los diluyentes tris y citrato de Na al 2.9% mostró diferencias significativas de IM, causadas principalmente por da o osmótico, manifiesto por la inflexión de los flagelos espermáticos en la fracción diluida en citrato de Na sin la adición del tensido. La alteración no se observó en tris. Tanto en tris como en citrato de Na el efecto favorable del tensido sobre la integridad de los acrosomas fue significativo. En el 2° ensayo, con el cambio comparativo de la formulación del diluyente citrato de Na por la adición de sulfanilamida, que elevó la osmolaridad y el pH, se repitió lo observado en el ensayo anterior: el efecto significativo del tensido sobre AN en tris y citrato de Na como también sobre IM en ambas formulaciones del diluyente citrato de Na. En el 3er. ensayo, destinado a comparar la sobrevivencia espermática en dos concentraciones del diluyente citrato de Na (2.9% vs. 3.1%), y a comparar un posible efecto deletéreo de la dilución rápida frente a una dilución lenta, no hubo diferencia entre las concentraciones del citrato de Na, como tampoco hubo una diferencia estadísticamente significativa entre ambas velocidades de dilución. El efecto del tensido sobre AN fue nuevamente significativo, como también sobre IM, al considerar las diferentes fracciones en conjunto. En el 4° ensayo, destinado a probar el efecto de una dilución lenta con diluyente tris, no se apreciaron diferencias frente a la dilución rápida. Nuevamente las fracciones con el tensido mostraron valores de AN significativamente mayores, te
Chatroom: "Conversations"?
Jara C.,Claudio Andrés;
Literatura y lingüística , 2003, DOI: 10.4067/S0716-58112003001400012
Abstract: the purpose of this article is to explore an emerging discourse, that of internet chatroom conversation. it tries to schematize the conversational relationships of the speakers in a text based medium and apply a pragmatic point of view based on cooperative principles within conversations
Chatroom: "Conversations"?
Claudio Andrés Jara C.
Literatura y lingüística , 2003,
Abstract: The purpose of this article is to explore an emerging discourse, that of Internet chatroom conversation. It tries to schematize the conversational relationships of the speakers in a text based medium and apply a pragmatic point of view based on cooperative principles within conversations El propósito de este artículo es el de explorar un discurso emergente, como es el de conversaciones en salas chat en el internet. Intenta esquematizar las relaciones conversacionales de los hablantes en un medio escrito y aplica un punto de vista pragmático basado en principios cooperativos dentro de conversaciones
Quenched nonequilibrium central limit theorem for a tagged particle in the exclusion process with bond disorder
M. D. Jara,C. Landim
Mathematics , 2006,
Abstract: For a sequence of i.i.d. random variables $\{\xi_x : x\in \bb Z\}$ bounded above and below by strictly positive finite constants, consider the nearest-neighbor one-dimensional simple exclusion process in which a particle at $x$ (resp. $x+1$) jumps to $x+1$ (resp. $x$) at rate $\xi_x$. We examine a quenched nonequilibrium central limit theorem for the position of a tagged particle in the exclusion process with bond disorder $\{\xi_x : x\in \bb Z\}$. We prove that the position of the tagged particle converges under diffusive scaling to a Gaussian process if the other particles are initially distributed according to a Bernoulli product measure associated to a smooth profile $\rho_0:\bb R\to [0,1]$.
Nonequilibrium Central Limit Theorem for a Tagged Particle in Symmetric Simple Exclusion
M. D. Jara,C. Landim
Mathematics , 2005, DOI: 10.1016/j.anihpb.2005.04.007
Abstract: We prove a nonequilibirum central limit theorem for the position of a tagged particle in the one-dimensional nearest-neighbor symmetric simple exclusion process under diffusive scaling starting from a Bernoulli product measure associated to a smooth profile $\rho_0:\bb R\to [0,1]$.
Retail Brand Equity: Measurements through Brand Policy and Store Formats  [PDF]
Magali Jara
American Journal of Industrial and Business Management (AJIBM) , 2018, DOI: 10.4236/ajibm.2018.83038
Abstract: This research extends findings on the retail brand equity in measuring the impact of its antecedents on the loyalty to the brand and to the store. This article raises questions about the sustainable created value by standard retail brands mostly oriented to functional components. The retail branding policy and store formats moderate results. This research adopts a PLS-Path modeling to test the retail brand equity model and its variations and then to provide a synthetic calculation of the retail brand equity. Results show that the standard retail brand equity leads to the loyalty to the brand and to the store. It varies according to: 1) the store brand policy (store’s own-named) appears to be a winning option maximizing the loyalty; 2) the “popular store” format—combining supermarket and department store—reinforces the sustainable relationship with customers because of the high level of service. By calculating scores, Carrefour brand maximizes the relationships within the model. This work focuses on French standard retail brands excluding other retail brands (such as generics or premium). Results also focus on one product category. The retailer’s positioning variable extends previous contributions leading to more consistent results. This research is also focused on the antecedents of retail brand equity too less studied: Benefits (received from their consumption) and the packaging of the branded product are thus integrated. Hence, perspectives for practitioners are suggested.
Estimación de la evapotranspiración de referencia para dos zonas (Costa Y Región Andina) del Ecuador
Vega, Emil C.;Jara, Jorge C.;
Engenharia Agrícola , 2009, DOI: 10.1590/S0100-69162009000300006
Abstract: in two locations of ecuador with similar latitude but different altitude (portoviejo, coastal zone and riobamba, andean zone) the holdrigde (ho) and hargreaves-samani (h-s) models and three modifications of these (daily, monthly and annual with constants cho and ke and kt, respectively) were fitted in order to estimate crop reference evapotranspiration (eto) for a range of moving averages in time, for a three day period. once cho, ke and kt were calibrated those eto estimates were compared with eto estimated by the pan evaporation method (eto pan). among cho (ho) and ke (h-s) coefficients, the best performance was achieved relating cho and ke to vapor pressure deficit, since it corrected the vertical thermal gradient and increased the precision in eto prediction, while relating the kt (h-s) coefficient to air temperature allowed the correction of the solar radiation. when comparing the three modifications of both models with eto pan, the daily cho model and the monthly h-s model generated slightly better eto estimates in portoviejo and riobamba, respectively. finally, in terms of quality of eto estimates, any of the three modifications of both models were better than those with penman-monteith in both locations.
LA UTILIZACIóN DE HERRAMIENTAS DE INVESTIGACIóN CUALITATIVA EN LA CONSTRUCCIóN Y DISE?O DE INDICADORES DE LA PRáCTICA DE ENFERMERíA
Jara C,Patricia; Valenzuela S,Sandra;
Ciencia y enfermería , 2009, DOI: 10.4067/S0717-95532009000300002
Abstract: the need to develop nursing practice indicators to asses the added value of the nurses participation who can relate to management and quality of care in providing health services, led to a research proposal which allowed a closer description of nursing practice and then a specific indicators outlining of this. this article aims to describe the nursing practice indicators'delineation process in intensive care units, using qualitative approaches.
La Osteodistrofia Renal y la Paratohormona supresora de la remodelación ósea
Cano Sch,Francisco; Jara C,Aquiles;
Revista chilena de pediatría , 2006, DOI: 10.4067/S0370-41062006000200002
Abstract: hyperparatiroidism plays a central role in renal osteodystrophy (rod) in patients with chronic renal failure (crf). the first plasmatic paratohormone (pth) determinations back in 1960 were based in radioinmunoanalysis (ria), using one antibody against the carboxiterminal or middle region of the hormone. in 1987, an inmunometric method (ima) based on two antibodies, denominated "intact pth" or "sandwich assay" was introduced, and it is used until today in clinical treatment, guideliness, and investigation of rod. in the late 1990s, authors detected two inmunoreactive peaks using the traditional method; one of them moved with intact pth 1-84 and the second peak migrated with the fraction 7-84, which suggested that an important inactive segment was included in the ima quantifications, increasing the real value of pth, therefore, exposing the patient to high doses of active vitamin d. this method allowed the separation of a biologically active fraction (cap-pth) from a bone-metabolism suppressor fraction (cip-pth), maybe associated to the lack of correlation between bone histomorphometry and intact pth 1-84. the increase of the adynamic form of rod and the presence of vascular calcifications in uremic adults have been related to high dosis of vitamin d, along with calcium and phosphorus therapies, that were orientated by plasmatic pth levels until nowadays. the current treatment of rod must be re-evaluated according to new knowledge, and future laboratory research will allow a better control of this crf complication
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