55 research outputs found
Excited States of Proton-bound DNA/RNA Base Homo-dimers: Pyrimidines
We are presenting the electronic photo fragment spectra of the protonated
pyrimidine DNA bases homo-dimers. Only the thymine dimer exhibits a well
structured vibrational progression, while protonated monomer shows broad
vibrational bands. This shows that proton bonding can block some non radiative
processes present in the monomer.Comment: We acknowledge the use of the computing facility cluster GMPCS of the
LUMAT federation (FR LUMAT 2764
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Fecal microbiota and bile acid interactions with systemic and adipose tissue metabolism in diet-induced weight loss of obese postmenopausal women
Microbiota and bile acids in the gastrointestinal tract profoundly alter systemic metabolic processes. In obese subjects, gradual weight loss ameliorates adipose tissue inflammation and related systemic changes. We assessed how rapid weight loss due to a very low calorie diet (VLCD) affects the fecal microbiome and fecal bile acid composition, and their interactions with the plasma metabolome and subcutaneous adipose tissue inflammation in obesity. We performed a prospective cohort study of VLCD-induced weight loss of 10% in ten grades 2-3 obese postmenopausal women in a metabolic unit. Baseline and post weight loss evaluation included fasting plasma analyzed by mass spectrometry, adipose tissue transcription by RNA sequencing, stool 16S rRNA sequencing for fecal microbiota, fecal bile acids by mass spectrometry, and urinary metabolic phenotyping by H-NMR spectroscopy. Outcome measures included mixed model correlations between changes in fecal microbiota and bile acid composition with changes in plasma metabolite and adipose tissue gene expression pathways. Alterations in the urinary metabolic phenotype following VLCD-induced weight loss were consistent with starvation ketosis, protein sparing, and disruptions to the functional status of the gut microbiota. We show that the core microbiome was preserved during VLCD-induced weight loss, but with changes in several groups of bacterial taxa with functional implications. UniFrac analysis showed overall parallel shifts in community structure, corresponding to reduced abundance of the genus Roseburia and increased Christensenellaceae;g__ (unknown genus). Imputed microbial functions showed changes in fat and carbohydrate metabolism. A significant fall in fecal total bile acid concentration and reduced deconjugation and 7-α-dihydroxylation were accompanied by significant changes in several bacterial taxa. Individual bile acids in feces correlated with amino acid, purine, and lipid metabolic pathways in plasma. Furthermore, several fecal bile acids and bacterial species correlated with altered gene expression pathways in adipose tissue. VLCD dietary intervention in obese women changed the composition of several fecal microbial populations while preserving the core fecal microbiome. Changes in individual microbial taxa and their functions correlated with variations in the plasma metabolome, fecal bile acid composition, and adipose tissue transcriptome
Quantitative Auger electron spectroscopy depth profiling of iron oxides formed on iron (100) and polycrystalline iron by exposure to gas-phase oxygen and borate buffer solutions
Benchmarking advanced architecture computers
Recently, a number of advanced architecture machines have become commercially available. These new machines promise better cost performance than traditional computers, and some of them have the potential of competing with current supercomputers, such as the CRAY XâMP, in terms of maximum performance. This paper describes the methodology and results of a pilot study of the performance of a broad range of advanced architecture computers using a number of complete scientific application programs. The computers evaluated include:
1.
sharedâmemory bus architecture machines such as the Alliant FX/8, the Encore Multimax, and the Sequent Balance and Symmetry
2.
sharedâmemory networkâconnected machines such as the Butterfly
3.
distributedâmemory machines such as the NCUBE, Intel and Jet Propulsion Laboratory (JPL)/Caltech hypercubes
4.
very long instruction word machines such as the Cydrome Cydraâ5
5.
SIMD machines such as the Connection Machine
6.
âtraditionalâ supercomputers such as the CRAY XâMP, CRAYâ2 and SCSâ40.
Seven application codes from a number of scientific disciplines have been used in the study, although not all the codes were run on every machine. The methodology and guidelines for establishing a standard set of benchmark programs for advanced architecture computers are discussed. The CRAYs offer the best performance on the benchmark suite; the shared memory multiprocessor machines generally permitted some parallelism, and when coupled with substantial floating point capabilities (as in the Alliant FX/8 and Sequent Symmetry), provided an order of magnitude less speed than the CRAYs. Likewise, the early generation hypercubes studied here generally ran slower than the CRAYs, but permitted substantial parallelism from each of the application codes
Benchmarking advanced architecture computers
Recently, a number of advanced architecture machines have become commercially available. These new machines promise better cost performance than traditional computers, and some of them have the potential of competing with current supercomputers, such as the CRAY XâMP, in terms of maximum performance. This paper describes the methodology and results of a pilot study of the performance of a broad range of advanced architecture computers using a number of complete scientific application programs. The computers evaluated include:
1.
sharedâmemory bus architecture machines such as the Alliant FX/8, the Encore Multimax, and the Sequent Balance and Symmetry
2.
sharedâmemory networkâconnected machines such as the Butterfly
3.
distributedâmemory machines such as the NCUBE, Intel and Jet Propulsion Laboratory (JPL)/Caltech hypercubes
4.
very long instruction word machines such as the Cydrome Cydraâ5
5.
SIMD machines such as the Connection Machine
6.
âtraditionalâ supercomputers such as the CRAY XâMP, CRAYâ2 and SCSâ40.
Seven application codes from a number of scientific disciplines have been used in the study, although not all the codes were run on every machine. The methodology and guidelines for establishing a standard set of benchmark programs for advanced architecture computers are discussed. The CRAYs offer the best performance on the benchmark suite; the shared memory multiprocessor machines generally permitted some parallelism, and when coupled with substantial floating point capabilities (as in the Alliant FX/8 and Sequent Symmetry), provided an order of magnitude less speed than the CRAYs. Likewise, the early generation hypercubes studied here generally ran slower than the CRAYs, but permitted substantial parallelism from each of the application codes
StreetâScale Mapping of Urban Radio Frequency Noise at Very High Frequency and Ultra High Frequency
Compassion and Community in Perinatal Palliative Care: Understanding the Necessity of the Patient Perspective Through Narrative Illustration
Individualized positive end-expiratory pressure in obese patients during general anaesthesia: a randomized controlled clinical trial using electrical impedance tomography
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