Concentrate levels and \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e affect rumen fluid-associated bacteria numbers in dairy heifers

Total viable rumenbacteria counts through the use of colony-unit forming assays lack accuracy because they only include culturable bacteria capable of initiating cell division. Thus, bacterial counts can be underestimated. The use of fluorescent characteristics of cell membranes allows flow cytometry to enumerate and distinguish dead from live bacteria cells. The objective of this experiment was to investigate the viable and total ruminal bacteria counts when 3 levels of forage:concentrate in diets were fed at restricted levels with the addition of Saccharomycescerevisiae (YC). Three cannulated post-pubertal Holstein heifers (age 18 ± 1.0 months) were fed corn silage (CS)-based diets in a 3-period (35 d) Latin square design. Heifers were fed the diets for 21 d with no yeast addition, followed by 14 d where yeast culture (YC) was added (1 g/kg as-fed basis); (Yea-Sacc1026, Alltech, Inc., Nicholasville, KY). A low concentrate (LC) TMR (80% CS, 20% concentrate; 12.4% CP, 35% NDF), a medium concentrate (MC) TMR (60% CS, 40% concentrate; 12.3% CP. 28% NDF), and a high concentrate (HC) TMR (40% CS, 60% concentrate; 12.6% CP, 25% NDF), were fed once per day. Rumenfluid was sampled − 2, 0, 2, 4, 6, 8, 10, 12 h after feeding. Samples were immediately stained with fluorescent dyes using the BacLight kit (Molecular Probes Inc., Eugene, OR) and analyzed with a Coulter XL-MCL single laser flow cytometer. Mean rumen viable bacteria counts linearly increased among treatments (4.96, 4.78, 6.73 × 1011 ± 0.53 × 1011 cells/ml; P = 0.02) for LC, MC and HC respectively, and YC addition increased number of viable bacteria cells (P \u3c 0.01). Total and viable bacteria counts decreased for the first 2 h after feeding then increased 4 h post-feeding. Dietary concentratelevel and YC can alter rumenbacteria counts as measured by this method

Contrasting levels of fructose and urea added to an annual ryegrass based diet: effects on microbial protein synthesis, nutrient digestibility and fermentation parameters in continuous culture fermenters

El objetivo de este experimento fue evaluar los efectos de la adición de fructosa cristalina y urea a una dieta basada en raigrás anual sobre la síntesis de proteína microbiana, la fermentación y la digestibilidad de los nutrientes, usando fermentadores de flujo continuo. Se usaron seis fermentadores de flujo continuo en un arreglo factorial 3x2, con tres niveles de hidratos de carbono solubles (WSC) obtenidos por la adición de fructosa cristalina (21, 24 y 27 g.100 g MS1; LWSC, MWSC y HWSC, respectivamente) y dos niveles de proteína bruta (CP) obtenidos por la adición de urea (14,6 y 18,6 g.100 g MS1, LCP y HCP, respectivamente). Se corrieron sucesivamente cuatro períodos de 10d (7d para adaptación, 3d para muestreo). La síntesis de proteína microbiana se estimó por la relación purinas: N. Hubo una interacción significativa entre niveles de WSC y CP para síntesis de proteína microbiana (P<0,001). El nivel de WSC no afectó el pH, la concentración de amonio ni la concentración de ácidos grasos volátiles (VFA). Niveles más altos de CP aumentaron la proporción de ácido acético y tendieron a aumentar la relación acético propiónico, mientras que el nivel de WSC no afectó las proporciones de VFA. Los tratamientos no afectaron la digestibilidad de los nutrientes. Concluimos que la adición de fructosa cristalina a dietas basadas en raigrás anual aumentó la síntesis de proteína microbiana a los niveles más altos de CP en la dieta.The objective of this experiment was to evaluate the effects of the addition of crystalline fructose and urea to an annual ryegrassbased diet on microbial protein synthesis, fermentation profile and nutrient apparent digestibility, using continuous culture fermenters. Six fermenters were used in a 3 x 2 factorial arrangement with three levels of water soluble carbohydrates (WSC) obtained by crystalline fructose addition (21, 24 and 27 g.100 g DM1; LWSC, MWSC and HWSC, respectively) and two levels of CP obtained by urea addition (14.6 and 18.6 g.100 g DM1, LCP and HCP, respectively). Four 10d periods were ran sequentially (7d for adaptation, 3d for sampling). Microbial protein synthesis was assessed by purine to N ratio. There was a positive interaction between WSC and CP level on microbial protein synthesis (P<0.001). Water soluble carbohydrate level did not affect fermentation pH, ammonia concentration or total volatile fatty acids concentration (VFA). Greater CP levels also increased acetic acid proportion and tended to increase acetic to propionic acid ratio, whereas WSC level did not affect VFA proportions. Treatments did not affect nutrient digestibility. We conclude that the addition of crystalline fructose to annual ryegrass samples increased microbial protein synthesis at the greater levels of CP in diet

Analysis of Coaxial Soil Cell in Reflection and Transmission

Accurate measurement of moisture content is a prime requirement in hydrological, geophysical and biogeochemical research as well as for material characterization and process control. Within these areas, accurate measurements of the surface area and bound water content is becoming increasingly important for providing answers to many fundamental questions ranging from characterization of cotton fiber maturity, to accurate characterization of soil water content in soil water conservation research to bio-plant water utilization to chemical reactions and diffusions of ionic species across membranes in cells as well as in the dense suspensions that occur in surface films. In these bound water materials, the errors in the traditional time-domain-reflectometer, “TDR”, exceed the range of the full span of the material’s permittivity that is being measured. Thus, there is a critical need to re-examine the TDR system and identify where the errors are to direct future research. One promising technique to address the increasing demands for higher accuracy water content measurements is utilization of electrical permittivity characterization of materials. This technique has enjoyed a strong following in the soil-science and geological community through measurements of apparent permittivity via time-domain-reflectometery as well in many process control applications. Recent research however, is indicating a need to increase the accuracy beyond that available from traditional TDR. The most logical pathway then becomes a transition from TDR based measurements to network analyzer measurements of absolute permittivity that will remove the adverse effects that high surface area soils and conductivity impart onto the measurements of apparent permittivity in traditional TDR applications. This research examines the theoretical basis behind the coaxial probe, from which the modern TDR probe originated from, to provide a basis on which to perform absolute permittivity measurements. The research reveals currently utilized formulations in accepted techniques for permittivity measurements which violate the underlying assumptions inherent in the basic models due to the TDR acting as an antenna by radiating energy off the end of the probe, rather than returning it back to the source as is the current assumption. To remove the effects of radiation from the experimental results obtain herein, this research utilized custom designed coaxial probes of various diameters and probe lengths by which to test the coaxial cell measurement technique for accuracy in determination of absolute permittivity. In doing so, the research reveals that the basic models available in the literature all omitted a key correction factor that is hypothesized by this research as being most likely due to fringe capacitance. To test this theory, a Poisson model of a coaxial cell was formulated to calculate the effective extra length provided by the fringe capacitance which is then used to correct the experimental results such that experimental measurements utilizing differing coaxial cell diameters and probe lengths, upon correction with the Poisson model derived correction factor, all produce the same results thereby lending support for the use of an augmented measurement technique, described herein, for measurement of absolute permittivity, as opposed to the traditional TDR measurement of apparent permittivity

Development and application of process-based simulation models for cotton production: a review of past, present, and future directions

The development and application of cropping system simulation models for cotton production has a long and rich history, beginning in the southeastern United States in the 1960's and now expanded to major cotton production regions globally. This paper briefly reviews the history of cotton simulation models, examines applications of the models since the turn of the century, and identifies opportunities for improving models and their use in cotton research and decision support. Cotton models reviewed include those specific to cotton (GOSSYM, Cotton2K, COTCO2, OZCOT, and CROPGRO-Cotton) and generic crop models that have been applied to cotton production (EPIC, WOFOST, SUCROS, GRAMI, CropSyst, and AquaCrop). Model application areas included crop water use and irrigation water management, nitrogen dynamics and fertilizer management, genetics and crop improvement, climatology, global climate change, precision agriculture, model integration with sensor data, economics, and classroom instruction. Generally, the literature demonstrated increased emphasis on cotton model development in the previous century and on cotton model application in the current century. Although efforts to develop cotton models have a 40-year history, no comparisons among cotton models were reported. Such efforts would be advisable as an initial step to evaluate current cotton simulation strategies. Increasingly, cotton simulation models are being applied by non-traditional crop modelers, who are not trained agronomists but wish to use the models for broad economic or life cycle analyses. While this trend demonstrates the growing interest in the models and their potential utility for a variety of applications, it necessitates the development of models with appropriate complexity and ease-of-use for a given application, and improved documentation and teaching materials are needed to educate potential model users. Spatial scaling issues are also increasingly prominent, as models originally developed for use at the field scale are being implemented for regional simulations over large geographic areas. Research steadily progresses toward the advanced goal of model integration with variable-rate control systems, which use real-time crop status and environmental information to spatially and temporally optimize applications of crop inputs, while also considering potential environmental impacts, resource limitations, and climate forecasts. Overall, the review demonstrates a languished effort in cotton simulation model development, but the application of existing models in a variety of research areas remains strong and continues to grow

Double-chambered right ventricle in an adult patient diagnosed by transthoracic echocardiography

BACKGROUND: Double-chambered right ventricle is a rare congenital disease frequently misdiagnosed in the adult patient. An anomalous muscle band divides the right ventricle in two cavities causing variable degree of obstruction. Although echocardiography is considered a useful method for the diagnosis of this pathology in children, it has been recognized the transthoracic scanning limitation in adults. CASE PRESENTATION: A 29 year-old patient with double-chambered right ventricle presenting mild exercise intolerance referred for follow up of a known ventricular septal defect in whom a complete diagnosis was obtained based only on transthoracic two dimensional echocardiography without the needing of cardiac catheterization. CONCLUSION: Based on non invasive echocardiographic diagnosis, patient was referred to surgical correction, which was completely successful

Resistencia a la compresión de Biodentine®: mezcla manual vs. Mecánica

INTRODUCCIÓN: La incorporación de innovaciones tecnológicas en determinados materiales dentales, especialmente aquellos que requieren de aparatología específica para su uso y/o cuya pre-dosificación implica el descarte de una porción de su contenido, está condicionada por la relación costo-beneficio del producto. Según las instrucciones del fabricante, las cápsulas del silicato tricálcico Biodentine® (Septodont) deben activarse mediante el uso de mezcladores mecánicos luego de adicionar las proporciones exactas del líquido ad-hoc, utilizando la totalidad de cada cápsula de polvo y su respectiva ampolla del líquido, con un excedente de material considerable, según su indicación. Si bien es posible realizar la mezcla del cemento en forma manual prescindiendo de un amalgamador, una modificación en las recomendaciones del fabricante podría alterar las propiedades del material. OBJETIVO: Determinar si existen diferencias en la resistencia compresiva de Biodentine® según el método de mezcla utilizado: con activación mecánica y con mezcla manual. MATERIALES Y METODOS: Se confeccionaron probetas cilíndricas de 6 mm de alto por 4 mm de diámetro (n=6) para los dos grupos de estudio A) Biodentine® / Mezcla manual y B) Biodentine® / Mezcla mecánica. Las muestras fueron sometidas a la aplicación de una fuerza continua en máquina universal de ensayos Digimess RS-8000-5 a una velocidad de carrera de 1 mm/min hasta su ruptura. Se compararon los valores obtenidos entre los grupos mediante test de Student, determinando diferencias significativas para valores de p>0,05. RESULTADOS: Los valores medios obtenidos y su desviación estándar fueron A) 52.6 (16.3) MPa y B) 65.7 (30.6) MPa respectivamente. La distribución de valores de resistencia a la compresión según el grupo de estudio fue levemente superior en el grupo B, aunque las diferencias no fueron significativas (p=3,77). CONCLUSIONES: La mezcla manual no disminuye significativamente la resistencia a la compresión de Biodentine® en comparación al cemento mezclado mecánicamente

Oral cysteamine as an adjunct treatment in cystic fibrosis pulmonary exacerbations: An exploratory randomized clinical trial

Background Emerging data suggests a possible role for cysteamine as an adjunct treatment for pulmonary exacerbations of cystic fibrosis (CF) that continue to be a major clinical challenge. There are no studies investigating the use of cysteamine in pulmonary exacerbations of CF. This exploratory randomized clinical trial was conducted to answer the question: In future pivotal trials of cysteamine as an adjunct treatment in pulmonary exacerbations of CF, which candidate cysteamine dosing regimens should be tested and which are the most appropriate, clinically meaningful outcome measures to employ as endpoints? Methods and findings Multicentre double-blind randomized clinical trial. Adults experiencing a pulmonary exacerbation of CF being treated with standard care that included aminoglycoside therapy were randomized equally to a concomitant 14-day course of placebo, or one of 5 dosing regimens of cysteamine. Outcomes were recorded on days 0, 7, 14 and 21 and included sputum bacterial load and the patient reported outcome measures (PROMs): Chronic Respiratory Infection Symptom Score (CRISS), the Cystic Fibrosis Questionnaire–Revised (CFQ-R); FEV1, blood leukocyte count, and inflammatory markers. Eighty nine participants in fifteen US and EU centres were randomized, 78 completed the 14-day treatment period. Cysteamine had no significant effect on sputum bacterial load, however technical difficulties limited interpretation. The most consistent findings were for cysteamine 450mg twice daily that had effects additional to that observed with placebo, with improved symptoms, CRISS additional 9.85 points (95% CI 0.02, 19.7) p = 0.05, reduced blood leukocyte count by 2.46x109 /l (95% CI 0.11, 4.80), p = 0.041 and reduced CRP by geometric mean 2.57 nmol/l (95% CI 0.15, 0.99), p = 0.049. Conclusion In this exploratory study cysteamine appeared to be safe and well-tolerated. Future pivotal trials investigating the utility of cysteamine in pulmonary exacerbations of CF need to include the cysteamine 450mg doses and CRISS and blood leukocyte count as outcome measures. Clinical trial registration NCT03000348; www.clinicaltrials.gov