1,084 research outputs found
Reconstruction of the Cosmic Equation of State for High Redshift
We investigate the possibilities of reconstructing the cosmic equation of
state (EoS) for high redshift. In order to obtain general results, we use two
model-independent approaches. The first reconstructs the EoS using comoving
distance and the second makes use of the Hubble parameter data. To implement
the first method, we use a recent set of Gamma-Ray Bursts (GRBs) measures. To
implement the second method, we generate simulated data using the Sandage-Loeb
() effect; for the fiducial model, we use the model. In both
cases, the statistical analysis is conducted through the Gaussian processes
(non-parametric). In general, we demonstrate that this methodology for
reconstructing the EoS using a non-parametric method plus a model-independent
approach works appropriately due to the feasibility of calculation and the ease
of introducing a priori information ( and ). In the near
future, following this methodology with a higher number of high quality data
will help obtain strong restrictions for the EoS.Comment: 9 pages, 5 figure
Interacting photon-baryon fluid, warm dark matter and the first acoustic peak
The Reduced Relativistic Gas (RRG) model was introduced by A. Sakharov in
1965 for deriving the cosmic microwave background (CMB) spectrum. It was
recently reinvented by some of us to achieve an interpolation between the
radiation and dust epochs in the evolution of the Universe. This model
circumvents the complicated structure of the Boltzmann-Einstein system of
equations and admits a transparent description of warm-dark-matter effects. It
is extended here to include, on a phenomenological basis, an out-of-equilibrium
interaction between radiation and baryons which is supposed to account for
relevant aspects of pre-recombination physics in a simplified manner.
Furthermore, we use the tight-coupling approximation to explore the influence
of both this interaction and of the RRG warmness parameter on the anisotropy
spectrum of the CMB. The predictions of the model are very similar to those of
the {\Lambda}CDM model if both the interaction and the dark-matter warmness
parameters are of the order of or smaller. As far as the warmness
parameter is concerned, this is in good agreement with previous estimations on
the basis of results from structure formation.Comment: 10 pages and 4 figure
Impact of Plant-Based Meat Alternatives on the Gut Microbiota of Consumers: A Real-World Study
Eating less meat is increasingly seen as a healthier, more ethical option. This is leading to growing numbers of flexitarian consumers looking for plant-based meat alternatives (PBMAs) to replace at least some of the animal meat they consume. Popular PBMA products amongst flexitarians, including plant-based mince, burgers, sausages and meatballs, are often perceived as low-quality, ultra-processed foods. However, we argue that the mere industrial processing of ingredients of plant origin does not make a PBMA product ultra-processed by default. To test our hypothesis, we conducted a randomised controlled trial to assess the changes to the gut microbiota of a group of 20 participants who replaced several meat-containing meals per week with meals cooked with PBMA products and compared these changes to those experienced by a size-matched control. Stool samples were subjected to 16S rRNA sequencing. The resulting raw data was analysed in a compositionality-aware manner, using a range of innovative bioinformatic methods. Noteworthy changes included an increase in butyrate metabolising potential—chiefly in the 4-aminobutyrate/succinate and glutarate pathways—and in the joint abundance of butyrate-producing taxa in the intervention group compared to control. We also observed a decrease in the Tenericutes phylum in the intervention group and an increase in the control group. Based on our findings, we concluded that the occasional replacement of animal meat with PBMA products seen in flexitarian dietary patterns can promote positive changes in the gut microbiome of consumers
The effect of heat treatments on the constituent materials of a nuclear reactor pressure vessel in hydrogen environment
AbstractA nuclear reactor pressure vessel (NRPV) wall is formed by two layer of different materials: an inner layer of stainless steel (cladding material) and an outer layer of low carbon steel (base material) which is highly susceptible to corrosion related phenomena. A reduction of the mechanical properties of both materials forming the wall would appear due to the action of the harsh environment causing hydrogen embrittlement (HE) related phenomena. As a result of the manufacturing process, residual stresses and strains appear in the NRPV wall, thereby influencing the main stage in HE: hydrogen diffusion. A common engineering practice for reducing such states is to apply a tempering heat treatment. In this paper, a numerical analysis is carried out for revealing the influence of the heat treatment parameters (tempering temperature and tempering time) on the HE of a commonly used NRPV. To achieve this goal, a numerical model of hydrogen diffusion assisted by stress and strain was used considering diverse residual stress-strain states after tempering. This way, the obtained hydrogen accumulation during operation time of the NRPV provides insight into the better tempering conditions from the structural integrity point of view
Harnessing the Power of Microbiome Assessment Tools as Part of Neuroprotective Nutrition and Lifestyle Medicine Interventions
An extensive body of evidence documents the importance of the gut microbiome both in health and in a variety of human diseases. Cell and animal studies describing this relationship abound, whilst clinical studies exploring the associations between changes in gut microbiota and the corresponding metabolites with neurodegeneration in the human brain have only begun to emerge more recently. Further, the findings of such studies are often difficult to translate into simple clinical applications that result in measurable health outcomes. The purpose of this paper is to appraise the literature on a select set of faecal biomarkers from a clinician’s perspective. This practical review aims to examine key physiological processes that influence both gastrointestinal, as well as brain health, and to discuss how tools such as the characterisation of commensal bacteria, the identification of potential opportunistic, pathogenic and parasitic organisms and the quantification of gut microbiome biomarkers and metabolites can help inform clinical decisions of nutrition and lifestyle medicine practitioners
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