21 research outputs found
Stochastic backgrounds of relic gravitons: a theoretical appraisal
Stochastic backgrounds or relic gravitons, if ever detected, will constitute
a prima facie evidence of physical processes taking place during the earliest
stages of the evolution of the plasma. The essentials of the stochastic
backgrounds of relic gravitons are hereby introduced and reviewed. The pivotal
observables customarily employed to infer the properties of the relic gravitons
are discussed both in the framework of the CDM paradigm as well as in
neighboring contexts. The complementarity between experiments measuring the
polarization of the Cosmic Microwave Background (such as, for instance, WMAP,
Capmap, Quad, Cbi, just to mention a few) and wide band interferometers (e.g.
Virgo, Ligo, Geo, Tama) is emphasized. While the analysis of the microwave sky
strongly constrains the low-frequency tail of the relic graviton spectrum,
wide-band detectors are sensitive to much higher frequencies where the spectral
energy density depends chiefly upon the (poorly known) rate of
post-inflationary expansion.Comment: 94 pages, 32 figure
Experiences of lifestyle change among women with gestational diabetes mellitus (GDM): A behavioural diagnosis using the COM-B model in a low-income setting
Lifestyle change can reduce the risk of developing type 2 diabetes among women with prior
gestational diabetes mellitus (GDM). While understanding women’s lived experiences and
views around GDM is critical to the development of behaviour change interventions to
reduce this risk, few studies have addressed this issue in low- and middle- income countries.
The aim of the study was to explore women’s lived experiences of GDM and the feasibility of
sustained lifestyle modification after GDM in a low-income setting
Ion homeostasis in the Chloroplast
peer reviewedThe chloroplast is an organelle of high demand for macro- and micro-nutrient ions, which are required for the maintenance of the photosynthetic process. To avoid deficiency while preventing excess, homeostasis mechanisms must be tightly regulated. Here, we describe the needs for nutrient ions in the chloroplast and briefly highlight their functions in the chloroplastidial metabolism. We further discuss the impact of nutrient deficiency on chloroplasts and the acclimation mechanisms that evolved to preserve the photosynthetic apparatus. We finally present what is known about import and export mechanisms for these ions. Whenever possible, a comparison between cyanobacteria, algae and plants is provided to add an evolutionary perspective to the description of ion homeostasis mechanisms in photosynthesis
Les cupules acétabulaires non cimentées sont-elles contre-indiquées chez les patients âgés?
Factor X Inhibitor: A Fulminant Presentation and Fatal Course of a Rare Syndrome in a 59-Year-Old Male
Characterization, Deposition Mechanisms and Modeling of Metallic Glass Powders for Cold Spray
This chapter describes recent efforts to understand the effects that chemical and physical properties of metallic glass (MG) powder particles have on the synthesis of their cold-sprayed coatings. Understanding the mechanical response of MG is fundamental to evaluate the conditions at which their powder particles can be deposited by cold spray. The characteristics of the feedstock powders are evaluated and used to ascertain ideal cold spray parameters. This information is also used to model the deposition mechanism of metallic glasses in the cold spray process. FE analysis and simulation is used to identify the phenomena behind the formation of MG coatings (i.e., homogenous or inhomogeneous deformation). The model defined considers strain rate and temperature dependence of MGs under different conditions
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Inflation physics from the cosmic microwave background and large scale structure
Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of CMB and large-scale structure (LSS) experiments are poised to test the leading paradigm for these earliest moments-the theory of cosmic inflation-and to detect the imprints of the inflationary epoch, thereby dramatically increasing our understanding of fundamental physics and the early universe. A future CMB experiment with sufficient angular resolution and frequency coverage that surveys at least 1% of the sky to a depth of 1 uK-arcmin can deliver a constraint on the tensor-to-scalar ratio that will either result in a 5σ measurement of the energy scale of inflation or rule out all large-field inflation models, even in the presence of foregrounds and the gravitational lensing B-mode signal. LSS experiments, particularly spectroscopic surveys such as the Dark Energy Spectroscopic Instrument, will complement the CMB effort by improving current constraints on running of the spectral index by up to a factor of four, improving constraints on curvature by a factor of ten, and providing non-Gaussianity constraints that are competitive with the current CMB bounds
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CMB-S4 Science Book, First Edition
This book lays out the scientific goals to be addressed by the
next-generation ground-based cosmic microwave background experiment, CMB-S4,
envisioned to consist of dedicated telescopes at the South Pole, the high
Chilean Atacama plateau and possibly a northern hemisphere site, all equipped
with new superconducting cameras. CMB-S4 will dramatically advance cosmological
studies by crossing critical thresholds in the search for the B-mode
polarization signature of primordial gravitational waves, in the determination
of the number and masses of the neutrinos, in the search for evidence of new
light relics, in constraining the nature of dark energy, and in testing general
relativity on large scales