2,864 research outputs found
Stable, metastable and unstable states in the mean-field RFIM at T=0
We compute the probability of finding metastable states at a given field in
the mean-field random field Ising model at T=0. Remarkably, this probability is
finite in the thermodynamic limit, even on the so-called ``unstable'' branch of
the magnetization curve. This implies that the branch is reachable when the
magnetization is controlled instead of the magnetic field, in contrast with the
situation in the pure system.Comment: 10 pages, 3 figure
Supernova Remnants as Clues to Their Progenitors
Supernovae shape the interstellar medium, chemically enrich their host
galaxies, and generate powerful interstellar shocks that drive future
generations of star formation. The shock produced by a supernova event acts as
a type of time machine, probing the mass loss history of the progenitor system
back to ages of 10 000 years before the explosion, whereas supernova
remnants probe a much earlier stage of stellar evolution, interacting with
material expelled during the progenitor's much earlier evolution. In this
chapter we will review how observations of supernova remnants allow us to infer
fundamental properties of the progenitor system. We will provide detailed
examples of how bulk characteristics of a remnant, such as its chemical
composition and dynamics, allow us to infer properties of the progenitor
evolution. In the latter half of this chapter, we will show how this exercise
may be extended from individual objects to SNR as classes of objects, and how
there are clear bifurcations in the dynamics and spectral characteristics of
core collapse and thermonuclear supernova remnants. We will finish the chapter
by touching on recent advances in the modeling of massive stars, and the
implications for observable properties of supernovae and their remnants.Comment: A chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and
Paul Murdin (18 pages, 6 figures
Atom--Molecule Coherence in a Bose-Einstein Condensate
Coherent coupling between atoms and molecules in a Bose-Einstein condensate
(BEC) has been observed. Oscillations between atomic and molecular states were
excited by sudden changes in the magnetic field near a Feshbach resonance and
persisted for many periods of the oscillation. The oscillation frequency was
measured over a large range of magnetic fields and is in excellent quantitative
agreement with the energy difference between the colliding atom threshold
energy and the energy of the bound molecular state. This agreement indicates
that we have created a quantum superposition of atoms and diatomic molecules,
which are chemically different species.Comment: 7 pages, 6 figure
Anålisis de los goles anotados en la Primera y Segunda División española durante la temporada 2017/2018
The aim of the present investigation was to know the typology of the goals scored in Spanish professional soccer through an observational analysis. 1137 goals (508 First division and 629 Second division) scored in 421 soccer matches corresponding to the 2017-2018 season in First and Second division were analyzed. All the goals were classified according to their typology. In general, most of the goals were scored with the legs, at the first touch and from within the area. No significant differences were obtained (p> 0.05) when comparing the typology of goals according to the category of the competition. However, significant differences were observed (p <0.05) when comparing the different playing positions. The results obtained suggest that specific training tasks should be proposed, depending on the playing position, in order to optimize the performance of the players' goal.El objetivo del presente estudio fue conocer la tipologĂa de los goles marcados en el fĂștbol profesional español mediante un anĂĄlisis observacional. Los 1137 goles (508 en Primera divisiĂłn y 629 Segunda divisiĂłn) marcados en los 421 partidos de fĂștbol correspondientes a la temporada 2017-2018 en Primera y Segunda divisiĂłn fueron analizados. Todos los goles se clasificaron en funciĂłn de su tipologĂa. De manera general, la mayorĂa de los goles se anotaron con las extremidades inferiores, al primer toque y desde dentro del ĂĄrea. No se obtuvieron diferencias significativas (p > 0,05) al comparar la tipologĂa de los goles en funciĂłn de la categorĂa de la competiciĂłn. Sin embargo, se observaron diferencias significativas (p < 0,05) al comparar los diferentes puestos especĂficos. Los resultados obtenidos sugieren que se deben plantear tareas de entrenamiento especĂficas, en funciĂłn del puesto especĂfico, con el fin de optimizar el rendimiento de cara a gol de los futbolistas
Expression of eicosanoid receptors subtypes and eosinophilic inflammation: implication on chronic rhinosinusitis
BACKGROUND: Eicosanoid receptors are G-protein-coupled receptors playing an important immunomodulatory role in airway diseases. However, there is little information on the expression of these receptors and their link with eosinophilic inflammation in paranasal sinus diseases. We aimed with this study to investigate the tissue expression of leukotrienes and prostaglandin E2 receptors in chronic rhinosinusitis patients and the link of this regulation with eosinophilic inflammation. METHODS: Samples were prepared from nasal tissue of patients with chronic rhinosinusitis without nasal polyps (CRS, n = 11), with nasal polyps (CRS-NP, n = 13) and healthy subjects (Controls, n = 6). mRNA expression of CysLT(1), CysLT(2), BLT(1), BLT(2), E-prostanoid receptors (EP(1), EP(2), EP(3), EP(4)) and sol-IL-5Rα was determined by real-time PCR. Concentrations of PGE2, LTC4/D4/E4, LTB4 and sol-IL-5Rα were determined by ELISA and of ECP by ImmunoCap. Protein expression and tissue localization of eicosanoid receptors and activated eosinophils were evaluated by immunohistochemistry. RESULTS: CysLT(1 )mRNA expression was significantly increased in CRS-NP compared to CRS and controls, and CRS compared to controls, whereas CysLT(2 )mRNA was enhanced in both CRS groups without differences between them. Levels of both receptors correlated to the number of activated eosinophils, sol-IL-5Rα, ECP and LTC(4)/D(4)/E(4 )concentrations in the disease groups. PGE(2 )protein concentrations and prostanoid receptors EP(1 )and EP(3 )were down-regulated in the CRS-NP tissue vs. CRS and controls, whereas EP(2 )and EP(4 )expression was enhanced in CRS and CRS-NP patients vs. controls. No differences in BLT receptors were observed between patients and controls. CONCLUSION: CyLTs receptors are up-regulated in nasal polyp tissue and their expression correlate with eosinophilic inflammation supporting previous results. Eicosanoid receptors mRNA pattern observed suggests that down-regulation of EP(1 )and EP(3 )in CRS-NP and up-regulation EP(2 )and EP(4 )in CRS and CRS-NP groups may have some role in the development of the diseases and their regulation may not be directly linked to eosinophil activation but involve post-transcriptional events mainly related to other inflammatory cell sources
The rise of policy coherence for development: a multi-causal approach
In recent years policy coherence for development (PCD) has become a key principle in international development debates, and it is likely to become even more relevant in the discussions on the post-2015 sustainable development goals. This article addresses the rise of PCD on the Western donorsâ aid agenda. While the concept already appeared in the work of Organisation for Economic Co-operation and Development (OECD) in the early 1990s, it took until 2007 before PCD became one of the Organisationâs key priorities. We adopt a complexity-sensitive perspective, involving a process-tracing analysis and a multi-causal explanatory framework. We argue that the rise of PCD is not as contingent as it looks. While actors such as the EU, the DAC and OECD Secretariat were the âactive causesâ of the rise of PCD, it is equally important to look at the underlying âconstitutive causesâ which enabled policy coherence to thrive well
The gradient flow running coupling with twisted boundary conditions
We study the gradient flow for Yang-Mills theories with twisted boundary
conditions. The perturbative behavior of the energy density is used to define a running coupling at a scale given by the
linear size of the finite volume box. We compute the non-perturbative running
of the pure gauge coupling constant and conclude that the technique is
well suited for further applications due to the relatively mild cutoff effects
of the step scaling function and the high numerical precision that can be
achieved in lattice simulations. We also comment on the inclusion of matter
fields.Comment: 27 pages. LaTe
Microbial catabolic activities are naturally selected by metabolic energy harvest rate
The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate
Labdane diterpenes protect against anoxia/reperfusion injury in cardiomyocytes: involvement of AKT activation
Several labdane diterpenes exert anti-inflammatory and cytoprotective actions; therefore, we have investigated whether these molecules protect cardiomyocytes in an anoxia/reperfusion (A/R) model, establishing the molecular mechanisms involved in the process. The cardioprotective activity of three diterpenes (T1, T2 and T3) was studied in the H9c2 cell line and in isolated rat cardiomyocyte subjected to A/R injury. In both cases, treatment with diterpenes T1 and T2 protected from A/R-induced apoptosis, as deduced by a decrease in the percentage of apoptotic and caspase-3 active positive cells, a decrease in the Bcl-2/Bax ratio and an increase in the expression of antiapoptotic proteins. Analysis of cell survival signaling pathways showed that diterpenes T1 and T2 added after A/R increased phospho-AKT and phospho-ERK 1/2 levels. These cardioprotective effects were lost when AKT activity was pharmacologically inhibited. Moreover, the labdane-induced cardioprotection involves activation of AMPK, suggesting a role for energy homeostasis in their mechanism of action. Labdane diterpenes (T1 and T2) also exerted cardioprotective effects against A/R-induced injury in isolated cardiomyocytes and the mechanisms involved activation of specific survival signals (PI3K/AKT pathways, ERK1/2 and AMPK) and inhibition of apoptosis
Tetrahydropyrazolo[1,5-a]Pyrimidine-3-Carboxamide and N-Benzyl-6âČ,7âČ-Dihydrospiro[Piperidine-4,4âČ-Thieno[3,2-c]Pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3
Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-caârboxamide(THPP) and N-benzyl-6âČ,7âČ-dihydrospiro[piperidine-4,â4âČ-thieno[3,2-c]pyran](Spiro) analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This âgenetic phenotypeâ was further confirmed by a âchemical phenotypeâ, whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice
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