516 research outputs found
Invasive breast cancer. Clinical, molecular and genetic aspects
El cáncer de mama es la segunda causa de muerte en EE.UU. A pesar de las modernas terapéuticas, de la tercera a la mitad de las pacientes que desarrollan la enfermedad, mueren por la misma. La efectividad limitada de los tratamientos actuales, ha focalizado los esfuerzos en la prevención, para lo cual es importante el conocimiento de las anormalidades biológicas que llevan a su desarrollo y progresión. Desde el punto de vista de la evolución, el cáncer de mama invasivo se desarrolla gradualmente de lesiones precursoras microscópicamente. Estas lesiones son relativamente pequeñas, sólo una pequeña proporción de las mismas progresa a cáncer invasivo. Muchas anormalidades biológicas son silentes. Identificar las anormalidades biológicas en lesiones premalignas permite conocer el riesgo de progresión a invasivo y prevenir antes que ocurra esta progresión.Facultad de Ciencias Médica
Grazing Behaviour of Beef Steers Grazing Kentucky 31 Endophyte Infected Tall Fescue, Q4508-AR542 Novel Endophyte Tall Fescue, and Lakota Prairie Grass
Tall fescue is the most dominant grass used for pasture in the U.S. covering over 14 million ha. As a result, fescue toxicosis is a major concern among producers, especially during the summer months when the symptoms, such as reduced weight gains, are most pronounced. Producers need alternative forages for grazing cattle that do not have the negative effects associated with endophyte infected tall fescue. The objective of this experiment was to determine the grazing behaviour of cattle on Kentucky 31 endophyte infected (E+) tall fescue (Festuca arundinacea Schreb.), Q4508-AR542 (Q) novel endophyte tall fescue, and Lakota (L) prairie grass (Bromus catharticus)
CONTROL BASED ON NUMERICAL METHODS AND RECURSIVE BAYESIAN ESTIMATION IN A CONTINUOUS ALCOHOLIC FERMENTATION PROCESS
Biotechnological processes represent a challenge in the control field, due to their high nonlinearity. In particular, continuous alcoholic fermentation from Zymomonas mobilis (Z.m) presents a significant challenge. This bioprocess has high ethanol performance, but it exhibits an oscillatory behavior in process variables due to the influence of inhibition dynamics (rate of ethanol concentration) over biomass, substrate, and product concentrations. In this work a new solution for control of biotechnological variables in the fermentation process is proposed, based on numerical methods and linear algebra. In addition, an improvement to a previously reported state estimator, based on particle filtering techniques, is used in the control loop. The feasibility estimator and its performance are demonstrated in the proposed control loop. This methodology makes it possible to develop a controller design through the use of dynamic analysis with a tested biomass estimator in Z.m and without the use of complex calculations
Linear algebra and optimization based controller design for trajectory tracking of typical chemical process
This paper presents a new controller design to tracking trajectory of a typical chemical process. The plant model is represented by numerical methods and, from this approach, the control actions for an optimal operation of the system are obtained. Its main advantage is that the condition for the tracking error tends to zero and the calculation of control actions, are obtained solving a system of linear equations. The proofs of convergence to zero of the tracking error are presented. Simulation results show the good performance of the proposed control system.Fil: Serrano, Mario Emanuel. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aballay, P.. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; ArgentinaFil: Ortiz, O. A.. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Instituto de Automática; Argentin
Performance and Carcass Characteristics of Feedlot Steers: Effects of Delayed Implanting and Programmed Feeding During the Growing Period
This experiment was conducted to determine the effect of programming the rate of gain and delaying the first implant in feedlot steers on feedlot performance and carcass characteristics. Ninety-six growing steers (269 ± 16.2 kg) were assigned to 12 pens in a completely randomized design. Treatments were implant (Synovex-S®; 20 mg estradiol benzoate and 200 mg progesterone; Fort Dodge Animal Health, Overland Park, KS) on d 1 or no implant and programmed feeding to gain at a slow (0.68 kg/d) or fast (1.14 kg/d) rate during the growing period; these treatments were randomly assigned (n = 8) to pens of steers in a 2 × 2 factorial arrangement. Steers were fed a growing diet and after 88 and 60 d (for steers fed to gain at a slow or fast rate, respectively), steers were transitioned to ad libitum consumption of a high concentrate finishing diet. Growing period implant treatments did not affect ADG but did affect (P\u3c0.01) gain efficiency during the finishing period. Feeding steers for a slow rate of BW gain during the growing period improved (P=0.062) gain efficiency in the finishing period (169 vs 145 g gain/kg feed). Correlation coefficients between fat thickness and marbling score obtained via ultrasound and fat thickness and marbling score measured at harvest were greater the closer the ultrasound measurements were made to the final harvest date. These data indicate that feeding level prior to the start of the finishing period may affect BW gain efficiency during the finishing period
Effectiveness Of Aminosidine (Paromomycin) Sulfate In Chronic Cryptosporidium Diarrhea In Aids Patients: An Open, Uncontrolled, Prospective Clinical Trial
Lynch Syndrome from a surgeon perspective: retrospective study of clinical impact of mismatch repair protein expression analysis in colorectal cancer patients less than 50 years old.
BACKGROUND:
In clinical practice, unexpected diagnosis of colorectal cancer in young patients requires prompt surgery, thus genetic testing for Lynch Syndrome is frequently missed, and clinical management may result incorrect.
METHODS:
Patients younger than 50 years old undergoing colorectal resection for cancer in the period 1994-2007 were identified (Group A, 49 cases), and compared to a group of randomly selected patients more than 50 (Group B, 85 cases). In 31 group A patients, immunohistochemical expression analysis of MLH1, MSH2 and MSH6 was performed; personal and familial history of patients with defective MMR proteins expression was further investigated, searching for synchronous and metachronous tumors in probands and their families.
RESULTS:
Fifty-one percent of patients did not express one or more MMR proteins (MMR-) and should be considered Lynch Syndrome carriers (16 patients, group A1); while only 31.2% of them were positive for Amsterdam criteria, 50% had almost another tumor, 37.5% had another colorectal tumor and 68% had relatives with colorectal tumor. This group of patients, compared with A2 group (< 50 years old, MMR+) and B group, showed typical characteristics of HNPCC, such as proximal location, mucinous histotype, poor differentiation, high stage and shorter survival.
CONCLUSIONS:
The present study confirms that preoperative knowledge of MMR proteins expression in colorectal cancer patients would allow correct staging, more extended colonic resection, specific follow-up and familial screening
Effect of Long-Term Nutrient Management Strategies for Pastures on Phosphorus in Surface Runoff and Soil Quality
Manure, whether mechanically applied or deposited by grazing animals, has been associated with increased risk of non-point source pollution, especially phosphorus. This is especially true in areas where the industry, especially poultry, has been concentrated in geographical areas that are grain deficient, resulting in a reliance on imported grain for poultry feed. Intensification has resulted in the production of large quantities of poultry manure, within relatively small geographical areas. Surplus litter is typically land applied as a nutrient source or used as an animal feed. The objective of this project was to evaluate the effects of long-term nutrient management strategies using poultry litter as a feed and fertiliser for grazed pasture systems in the Shenandoah Valley of Virginia on soil quality, selected soil chemical characteristics and P losses in surface runoff
Development of a tomato pomace biorefinery based on a CO2-supercritical extraction process for the production of a high value lycopene product, bioenergy and digestate
Tomato peels and seeds (TP) are the most abundant canning industry waste actually used to produce biogas. TP is rich in lycopene (lyc) and represent a more sustainable feedstock than tomato fruits actually employed. It was therefore chosen as feedstock together with supercritical CO2 extraction (SFE-CO2) technology to develop a TP-SFE-CO2 biorefinery, topic scarcely investigated. Two TP were tested and although TP-SFE-CO2 parameters were the same, lyc recoveries depended by peel structure changes occurred during pre -SFE-CO2 drying step. Higher moisture (102.7 g kg-1 wet weight) permitted 97 % lyc recovery and gave a water-in-oil emulsion as extract. Mass balance confirmed that lyc isomerisation did not cause lyc losses. After a significant oil extraction, exhaust TP showed a biodegradability 64% higher than the raw one, attributable to fibre structure disruption. The biorefinery proposed (SFE_CO2+anaerobic digestion) determined positive economic revenue (+787.9 \u20ac t-1 TP) on the contrary of the actual TP management
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