Activities of the enzymes of hepatic gluconeogenesis in periparturient dairy cows with induced fatty liver

The objective was to measure the activities of all the enzymes essential for hepatic gluconeogenesis in dairy cows with induced fatty liver. We aimed to induce severe fatty liver in ten experimental cows by overfeeding them during the dry period while seven control cows were maintained on a restricted diet. To induce a marked negative energy balance, the experimental cows were deprived of feed for 8 h immediately after parturition. In addition, the experimental cows were given a restricted amount of diet during the first 5 d of lactation. Liver samples were collected 1 week before and 1, 2 and 4 weeks after parturition. Before parturition, liver triacylglycerol concentrations did not differ between the two groups. After parturition, the experimental cows developed marked fatty liver as indicated by a higher level of triacylglycerols in the liver compared with the control cows. Before parturition, all gluconeogenic enzymes in the liver were lower in experimental cows than in control cows. Phosphoenolpyruvate carboxykinase, pyruvate carboxylase and propionyl-CoA carboxylase were significantly lower and fructose 1,6-bisphosphatase and glucose 6-phosphatase tended to be lower in the experimental cows. The activities of two crucial enzymes for gluconeogenesis in ruminants, i.e., phosphoenolpyruvate carboxykinase and propionyl-CoA carboxylase, remained low throughout the sampling period post partum. Activities of pyruvate carboxylase and glucose 6-phosphatase in the experimental cows post partum were upgraded to values similar to those of the control cows. The results showed that the capacity for hepatic gluconeogenesis before parturition was lower in cows with induced fatty liver than in control cows. After parturition, the low activities of crucial gluconeogenic enzymes indicated insufficient production of glucose. It is suggested that the low gluconeogenic capacity leads successively to low blood glucose concentrations, low insulin levels and high rates of mobilization of fatty acid, causing severe hepatic lipidosis.     

On-line coupling of high-performance liquid chromatography to a continuous-flow enzyme assay based on electrospray ionization mass spectrometry

Liquid chromatography (LC) was coupled on-line to a continuous-flow enzymatic assay using electrospray ionization mass spectrometry (ESI-MS) as readout for the screening of enzyme inhibitors in complex samples. Inhibitors were detected by changes in the concentration of the enzymatic reaction products, indicating the inhibition of enzymatic activity. The molecular masses of the inhibitors were determined with high certainty by using retention time matching and peak shape comparison. Due to the high matching accuracy, baseline separation of coeluting analytes was not necessary in order to identify the correct masses of the bioactive compounds. The continuous-flow system was successfully applied for the screening of complex samples, such as natural extracts. For a red clover extract, detection limits of 0.3-0.8 micromol/L were obtained. System validation was performed by determining the IC(50) values of four inhibitors in the flow-injection mode. The IC(50) values were in the 0.11-5.6 micromol/L range and correspond closely to data obtained by microtiter plate assays. Detection limits were in the range of 0.018-0.35 micromol/L in the flow-injection mode, and 0.075-0.75 micromol/L in the LC mode. These values are well below the typical compound concentrations (1-10 micromol/L) used in high-throughput screening. Together with an interday precision of 12.6%, these results demonstrate the applicability of the system for bioactivity screening of complex mixtures, generating both chemical and biological information on bioactive compounds in a single run.     

Flows in micro fluidic networks: From theory to experiment

When complex flow structures are designed, such as in DNA computing, it is essential to be able to predict the flow pattern of the solutions in the fluidic network. A model based on the resistance of the channels and flow velocities of the inlets can eliminated re-iterative design steps. We have constructed a symbolic model using Mathematica ® to determine the desired flow pattern based on the equations of Ohm and Kirchoff. The values from this simulation were used in a flow simulation program and then tested in a microflow network. Results show that the simulation and calculation match very well, while the experiments in the fluidic network show a flow pattern as predicted by the model.     

Best Linear Unbiased Estimator of the Parameter of the Rayleigh Distribution?Part I: Small Sample Theory for Censored Order Statistics

The best linear unbiased estimator of the parameter of the Rayleigh distribution using order statistics in a Type II censored sample from a potential sample of size N is considered. The coefficients for this estimator are tabled to five decimal places for N = 2(1)15 and censoring values of r1, (the number of observations censored from the left) and r2 (the number of observations censored from the right) such that r1 + r2 ? N - 2 for N = 2(1)10, r1 + r2 ? N - 3 for N = 11(1)15.     

Review of Meeting Movies.

Reviews the book, Meeting Movies by Norman N. Holland (see record 2006-11509-000). Meeting Movies is a very personal book in which Holland discusses eight films that have been personally meaningful to him. These films are Casablanca, Vertigo, The Seventh Seal, Freud, Persona, Children of Paradise, Shakespeare in Love, and 8 1/2. Holland describes what he was doing with his life when he saw each of these films, and he discusses how each film affected his life and his career. Some of the movies were seen relatively recently, and some were first viewed over half a century ago. In reading the book, it becomes apparent that Holland loves films. Whenever text is in Roman type, Holland is operating in his reader-response critic mode, and the discussion reads much like any other film criticism. However, the most interesting parts of the book occur when Holland is in free association mode, writing about whatever thoughts the movie being discussed brings to mind. These instances are set off from the regular text by use of italicized text. In summary, Meeting Movies is a good read. Holland is well versed in psychology and especially psychoanalytic approaches, and his criticism of these eight films is consistently interesting. His willingness to self-disclose makes this book all the more fascinating. The book will be rewarding for anyone genuinely interested in the interface of psychology and film. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of wind generation on the operation and development of the UK electricity systems

Although penetration of wind generation may displace a significant amount of energy produced by large conventional plant, there are issues associated with the extent to which wind generation will be able to replace the capacity and flexibility of conventional generating plant. This is important since wind power is variable, so it will be necessary to retain a significant proportion of conventional plant to ensure security of supply especially under conditions of high demand and low wind. Hence, the capacity value of wind generation will be limited as it will not be possible to displace conventional generation capacity on a “megawatt for megawatt” basis. Wind power is variable and not easy to predict, hence various forms of additional reserves will be needed to maintain the balance between supply and demand at all times. Additionally, if the majority of wind generation plant is located in Scotland and the North of England, reinforcement of the transmission network will be needed to accommodate the increases in the north-south flow of electricity.     

SIFER: Scale-Invariant Feature Detector with Error Resilience

We present a new method to extract scale-invariant features from an image by using a Cosine Modulated Gaussian (CM-Gaussian) filter. Its balanced scale-space atom with minimal spread in scale and space leads to an outstanding scale-invariant feature detection quality, albeit at reduced planar rotational invariance. Both sharp and distributed features like corners and blobs are reliably detected, irrespective of various image artifacts and camera parameter variations, except for planar rotation. The CM-Gaussian filters are approximated with the sum of exponentials as a single, fixed-length filter and equal approximation error over all scales, providing constant-time, low-cost image filtering implementations. The approximation error of the corresponding digital signal processing is below the noise threshold. It is scalable with the filter order, providing many quality-complexity trade-off working points. We validate the efficiency of the proposed feature detection algorithm on image registration applications over a wide range of testbench conditions.