4,027 research outputs found
Lipid Metabolism and Comparative Genomics
Unilever asked the Study Group to focus on two problems. The first concerned dysregulated lipid metabolism which is a feature of many diseases including metabolic syndrome, obesity and coronary heart disease. The Study Group was asked to develop a model of the kinetics of lipoprotein metabolism between healthy and obese states incorporating the activities of key enzymes.
The second concerned the use of comparative genomics in understanding and comparing metabolic networks in bacterium. Comparative genomics is a method to make inferences on the genome of a new organism using information of a previously charaterised organism. The first mathematical question is how one would quantify such a metabolic map in a statistical sense, in particular, where there are different levels of confidence for presense of different parts of the map. The next and most important question is how one can design a measurement strategy to maximise the confidence in the accuracy of the metabolic map
Reducing CO2 Emissions in the Upper Midwest: Technology, Resources, Economics, and Policy
We develop scenarios for reducing carbon dioxide emissions from the electricity sector in the upper Midwest (Wisconsin, Illinois, Minnesota, Iowa, North Dakota, South Dakota, Montana, Wyoming, and Manitoba) by 80% relative to 1990 levels. The report has three major components: 1) an inventory of CO2 emissions from all fossil fuel combustion in the region from 1960-2001, subdividing by economic sector and specific electricity generating station; 2) an evaluation of all electricity resources in the region and all technologies for utilizing them, taking into account the overall scale of the resource, technology costs, and other issues that influence the selection of a certain technology; and 3) the development of a simulation model to examine the impact of various factors (policies, prices, technologies, resources) on the regional electricity supply and its emissions from 2005-2055.Environmental Economics and Policy,
Initial test results on bolometers for the Planck high frequency instrument
We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm
An investigation into the sample preparation procedure and analysis of cyanoacrylate adhesives using capillary electrophoresis
In this study, the trace acid profile of cyanoacrylate adhesives was studied using capillary electrophoresis. Liquid–liquid extraction was employed as the sample preparation step before separation by capillary electrophoresis. The solubility of the adhesives was investigated using various organic solvents, e.g. hexane and dichloromethane, and chloroform was determined to be the optimum solvent as it enabled the full dissolution of the adhesive. A comprehensive stability study was performed over a 3-year period and results indicate that the adhesives were stable for 2 years after which their stability and performance degraded
Transcriptional Enhancers in the Regulation of T Cell Differentiation
The changes in phenotype and function that characterise the differentiation of naïve T cells to effector and memory states are underscored by large-scale, coordinated, and stable changes in gene expression. In turn, these changes are choreographed by the interplay between transcription factors and epigenetic regulators that act to restructure the genome, ultimately ensuring lineage-appropriate gene expression. Here, we focus on the mechanisms that control T cell differentiation, with a particular focus on the role of regulatory elements encoded within the genome, known as transcriptional enhancers. We discuss the central role of transcriptional enhancers in regulating T cell differentiation, both in health and disease
The influence of self-selected music on affect-regulated exercise intensity and remembered pleasure during treadmill running.
This study explored the influence of self-selected music on affect-regulated exercise intensity and Remembered Pleasure. Seventeen active male and female participants (28.1 ±9.9 years; BMI 23.8±3.2 kg/m2; VO2 peak 48.73±8.73 ml.min−1.kg−1) completed a maximal exercise test and each individual’s ventilatory threshold (VT) was identified. Following this, two treadmill exercise trials were performed at an intensity that was perceived to correspond to a Feeling Scale value of +3 (i.e. ‘good’). Sessions with either self-selected music or no music were completed 48 hr apart and in a randomized counterbalanced order. Affective responses (Feeling Scale) and heart rate were measured during exercise and Remembered Pleasure was measured 5-min post exercise. Results indicated that participants selected an exercise intensity that exceeded their VT during the two affect-regulated exercise sessions (p = .002, d = .99). Participants exercised with greater intensity during affect-regulated exercise with music than without (p = .045; d = 1.12) while maintaining a ‘good’ feeling. Furthermore, participants recalled the music session as more pleasurable than the no-music session (p = .001; d = .72). These results illustrate a positive ergogenic and psychological influence of music during affect-regulated exercise. Encouraging individuals to exercise at an intensity that feels ‘good’ elicits an exercise intensity sufficient to garner cardiorespiratory benefits and may lead to improved adherence. Moreover, the use of self-selected music appears to augment this effect.
(226 words)
Keywords: Affect, exercise, heuristics, remembered utility, physical activit
The Benchmark Ultracool Subdwarf HD 114762B: A Test of Low-Metallicity Atmospheric and Evolutionary Models
We present a near-infrared spectroscopic study of HD 114762B, the latest-type
metal-poor companion discovered to date and the only ultracool subdwarf with a
known metallicity, inferred from the primary star to be [Fe/H] = -0.7. We
obtained a medium-resolution Keck/OSIRIS J-band spectrum and a low-resolution
IRTF/SpeX 0.8-2.4 um spectrum of HD 114762B. HD 114762B exhibits spectral
features common to both late-type dwarfs and subdwarfs, and we assign it a
spectral type of d/sdM9 +/- 1. We use a Monte Carlo technique to fit
PHOENIX/GAIA synthetic spectra to the observations, accounting for the
coarsely-gridded nature of the models. Fits to the entire OSIRIS J-band and to
the metal-sensitive J-band atomic absorption features (Fe I, K I, and Al I
lines) yield model parameters that are most consistent with the metallicity of
the primary star and the high surface gravity expected of old late-type
objects. The effective temperatures and radii inferred from the model
atmosphere fitting broadly agree with those predicted by the evolutionary
models of Chabrier & Baraffe, and the model color-absolute magnitude relations
accurately predict the metallicity of HD 114762B. We conclude that current
low-mass, mildly metal-poor atmospheric and evolutionary models are mutually
consistent for spectral fits to medium-resolution J-band spectra of HD 114762B,
but are inconsistent for fits to low-resolution near-infrared spectra of mild
subdwarfs. Finally, we develop a technique for estimating distances to
ultracool subdwarfs based on a single near-infrared spectrum. We show that this
"spectroscopic parallax" method enables distance estimates accurate to < 10% of
parallactic distances for ultracool subdwarfs near the hydrogen burning minimum
mass. (abridged)Comment: Accepted by ApJ; 23 pages, 20 figure
Absolute polarization angle calibration using polarized diffuse Galactic emission observed by BICEP
We present a method of cross-calibrating the polarization angle of a
polarimeter using BICEP Galactic observations. \bicep\ was a ground based
experiment using an array of 49 pairs of polarization sensitive bolometers
observing from the geographic South Pole at 100 and 150 GHz. The BICEP
polarimeter is calibrated to +/-0.01 in cross-polarization and less than +/-0.7
degrees in absolute polarization orientation. BICEP observed the temperature
and polarization of the Galactic plane (R.A= 100 degrees ~ 270 degrees and Dec.
= -67 degrees ~ -48 degrees). We show that the statistical error in the 100 GHz
BICEP Galaxy map can constrain the polarization angle offset of WMAP Wband to
0.6 degrees +\- 1.4 degrees. The expected 1 sigma errors on the polarization
angle cross-calibration for Planck or EPIC are 1.3 degrees and 0.3 degrees at
100 and 150 GHz, respectively. We also discuss the expected improvement of the
BICEP Galactic field observations with forthcoming BICEP2 and Keck
observations.Comment: 13 pages, 10 figures and 2 tables. To appear in Proceedings of SPIE
Astronomical Telescopes and Instrumentation 201
The Generation of Successive Unmarked Mutations and Chromosomal Insertion of Heterologous Genes in Actinobacillus pleuropneumoniae Using Natural Transformation
We have developed a simple method of generating scarless, unmarked mutations in Actinobacillus pleuropneumoniae by exploiting the ability of this bacterium to undergo natural transformation, and with no need to introduce plasmids encoding recombinases or resolvases. This method involves two successive rounds of natural transformation using linear DNA: the first introduces a cassette carrying cat (which allows selection by chloramphenicol) and sacB (which allows counter-selection using sucrose) flanked by sequences to either side of the target gene; the second transformation utilises the flanking sequences ligated directly to each other in order to remove the cat-sacB cassette. In order to ensure efficient uptake of the target DNA during transformation, A. pleuropneumoniae uptake sequences are added into the constructs used in both rounds of transformation. This method can be used to generate multiple successive deletions and can also be used to introduce targeted point mutations or insertions of heterologous genes into the A. pleuropneumoniae chromosome for development of live attenuated vaccine strains. So far, we have applied this method to highly transformable isolates of serovars 8 (MIDG2331), which is the most prevalent in the UK, and 15 (HS143). By screening clinical isolates of other serovars, it should be possible to identify other amenable strains
Comparative Efficacy of Dorsal Root Ganglion Versus Spinal Cord Stimulation in the Management of Complex Regional Pain Syndrome and Failed Back Surgery Syndrome: A Narrative Review
Background: Complex Regional Pain Syndrome (CRPS) and Failed Back Surgery Syndrome (FBSS) are challenging neuropathic pain conditions often refractory to conservative treatment. Neuromodulation offers a promising solution, particularly with spinal cord stimulation (SCS) and dorsal root ganglion stimulation (DRG-S).
Objective: This review compares DRG-S and SCS in CRPS and FBSS to evaluate their relative efficacy, safety, and clinical utility.
Methods: A narrative literature review was conducted using peer-reviewed sources focusing on the use of DRG-S and SCS in CRPS and FBSS populations.
Results: DRG-S offers enhanced targeting of focal pain areas in CRPS, while SCS provides broader coverage useful in FBSS. DRG-S demonstrates superior outcomes in CRPS regarding pain relief and functional improvement. Lead migration, a common complication in both, is reportedly lower in DRG-S.
Conclusion: DRG-S is particularly effective in CRPS due to precise anatomic targeting, while SCS remains valuable in FBSS. Further randomized studies are needed to confirm long-term comparative efficacy
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