Thermalisation time and specific heat of neutron stars crust

We discuss the thermalisation process of the neutron stars crust described by solving the heat transport equation with a microscopic input for the specific heat of baryonic matter. The heat equation is solved with initial conditions specific to a rapid cooling of the core. To calculate the specific heat of inner crust baryonic matter, i.e., nuclear clusters and unbound neutrons, we use the quasiparticle spectrum provided by the Hartree-Fock-Bogoliubov approach at finite temperature. In this framework we analyse the dependence of the crust thermalisation on pairing properties and on cluster structure of inner crust matter. It is shown that the pairing correlations reduce the crust thermalisation time by a very large fraction. The calculations show also that the nuclear clusters have a non-negligible influence on the time evolution of the surface temperature of the neutron star.Comment: 7 pages, 5 figures, submitted to Phys. Rev.

Candida auris: a literature review

Background: Emerging pathogen Candida auris has been associated with nosocomial outbreaks demonstrating widespread antifungal resistance. This microorganism is associated with systemic infections with a high mortality rate, and studies that contribute to a better understanding of this agent are important. Objectives: The present article aimed to carry out bibliographic research on Candida auris. Therefore, a literature search was carried out between January 2018 and January 2022, applying the following: C. auris; Candida auris and Infection, in Portuguese, English and Spanish. This review considers the available literature on C. auris and highlights key unknowns, which will provide guidance for future work in this field. Results: The data collected in the present review allowed us to divide the theme into topics on Pathophysiology, Epidemiology/clinical and drug resistance mechanisms, so that the understanding of Candida auris can be better detailed and understood. Conclusion: The predilection of C. auris by the most vulnerable and immunosuppressed patients or with comorbidities and with the potential to cause invasive and bloodstream infections with a propensity to cause outbreaks and concerns regarding resistance to antifungal agents, the fungus Candida auris, is of increasing clinical relevance. The increase in the number of detected cases and the occurrence of strains with multiple drug resistance prove to be worrisome, and applied research is essential to contribute to the knowledge of this strain and effective therapy

A New Mapping Protocol for Laser Ablation (with Fast‐Funnel ) Coupled to a Time‐of‐Flight Mass Spectrometer ( LA‐FF‐ICP‐ToF‐MS ) for the Rapid, Simultaneous Quantification of Multiple Minerals

Although in situ analysis by LA-ICP-MS is considered a rapid technique with minimal sample preparation and data reduction, mapping areas of millimetres in size using a small beam (< 15 μm) can be time consuming (several hours) when a quadrupole ICP-MS is used. In addition, fully quantitative imaging using internal standardisation by LA-ICP-MS is challenging in samples with more than one mineral phase present due to varying ablation rates. A new protocol for the quantification of multiple coexisting phases, mapped at a rate of about 12 mm2 h-1 and a resolution of 12 μm × 12 μm per pixel, is presented. The protocol allows mapping of most atomic masses, ranging from 23Na to 238U, using a time-of-flight mass spectrometer (ICP-ToF-MS, TOFWERK) connected to a 193 nm excimer laser. A fast-funnel device was successfully used to increase the aerosol transport speed, reducing the time usually required for mapping by a factor of about ten compared with a quadrupole ICP-MS. The lower limits of detection for mid and heavy masses are in the range 0.1–10 μg g-1, allowing determination of trace to ultra-trace elements. The presented protocol is intended to be a routine analytical tool that can provide greater access to the spatial distribution of major and trace elements in geological materials

Why honey is effective as a medicine. 1. Its use in modern medicine

Honey has been used as a medicine for thousands of years and its curative properties are well documented. However, modern medicine turned its back on honey and it is only now, with the advent of multi-resistant bacteria, that the antibiotic properties of honey are being rediscovered

Osteoinductive PolyHIPE Foams as Injectable Bone Grafts

We have recently fabricated biodegradable polyHIPEs as injectable bone grafts and characterized the mechanical properties, pore architecture, and cure rates. In this study, calcium phosphate nanoparticles and demineralized bone matrix (DBM) particles were incorporated into injectable polyHIPE foams to promote osteoblastic differentiation of mesenchymal stem cells (MSCs). Upon incorporation of each type of particle, stable monoliths were formed with compressive properties comparable to control polyHIPEs. Pore size quantification indicated a negligible effect of all particles on emulsion stability and resulting pore architecture. Alizarin red calcium staining illustrated the incorporation of calcium phosphate particles at the pore surface, while picrosirius red collagen staining illustrated collagen-rich DBM particles within the monoliths. Osteoinductive particles had a negligible effect on the compressive modulus (∼30 MPa), which remained comparable to human cancellous bone values. All polyHIPE compositions promoted human MSC viability (∼90%) through 2 weeks. Furthermore, gene expression analysis indicated the ability of all polyHIPE compositions to promote osteogenic differentiation through the upregulation of bone-specific markers compared to a time zero control. These findings illustrate the potential for these osteoinductive polyHIPEs to promote osteogenesis and validate future in vivo evaluation. Overall, this work demonstrates the ability to incorporate a range of bioactive components into propylene fumarate dimethacrylate-based injectable polyHIPEs to increase cellular interactions and direct specific behavior without compromising scaffold architecture and resulting properties for various tissue engineering applications

A grounded theory of positive youth development through sport based on results from a qualitative meta-study

The overall purpose of this study was to create a model of positive youth development (PYD) through sport grounded in the extant qualitative literature. More specifically, the first objective was to review and evaluate qualitative studies of PYD in sport. The second objective was to analyze and synthesize findings from these studies. Following record identification and screening, 63 articles were retained for analysis. Meta-method analysis revealed strengths of studies were the use of multiple data collection and validity techniques, which produced high-quality data. Weaknesses were limited use of ‘named’ methodologies and inadequate reporting of sampling procedures. Philosophical perspectives were rarely reported, and theory was used sparingly. Results of an inductive meta-data analysis produced three categories: PYD climate (adult relationships, peer relationships, and parental involvement), life skills program focus (life skill building activities and transfer activities), and PYD outcomes (in personal, social, and physical domains). A model that distinguishes between implicit and explicit processes to PYD is presented

Nouveau décodeur à complexité réduite pour codes convolutifs de rendement 1/2

Les codes convolutifs peuvent être décodés de façon optimale à l'aide l'algorithme de Viterbi (VA). Nous proposons un décodeur à entrée souple dans lequel l'algorithme de Viterbi est employé pour identifier le vecteur d'erreur plutôt que le message d'information avec une métrique appropriée. Ce type de décodage permet d'éviter la mise en oeuvre d'un nombre important d'opérations ACS (Add Compare Select). Nous montrons que les performances atteintes sont proches de l'optimum tout en bénéficiant d'une réduction de la complexité qui est d'autant plus importante que le rapport signal à bruit (SNR) est favorable. Par exemple, pour des SNR supérieurs à 3 dB et dans le cas d'une transmission avec la modulation BPSK sur canal gaussien, au moins 88% des ACS peuvent être évités

Minimal Cooling of Neutron Stars: A New Paradigm

A new classification of neutron star cooling scenarios, involving either ``minimal'' cooling or ``enhanced'' cooling is proposed. The minimal cooling scenario replaces and extends the so-called standard cooling scenario to include neutrino emission from the Cooper pair breaking and formation process. This emission dominates that due to the modified Urca process for temperatures close to the critical temperature for superfluid pairing. Minimal cooling is distinguished from enhanced cooling by the absence of neutrino emission from any direct Urca process, due either to nucleons or to exotica. Within the minimal cooling scenario, theoretical cooling models can be considered to be a four parameter family involving the equation of state of dense matter, superfluid properties of dense matter, the composition of the neutron star envelope, and the mass of the neutron star. Consequences of minimal cooling are explored through extensive variations of these parameters. Results are compared with the inferred properties of thermally-emitting neutron stars in order to ascertain if enhanced cooling occurs in any of them. All stars for which thermal emissions have been clearly detected are at least marginally consistent with the lack of enhanced cooling. The two pulsars PSR 0833-45 (Vela) and PSR 1706-44 would require enhanced cooling in case their ages and/or temperatures are on the lower side of their estimated values whereas the four stars PSR 0656+14, PSR 1055-52, Geminga, and RX J0720.4-3125 may require some source of internal heating in case their age and/or luminosity are on the upper side of their estimated values. The new upper limits on the thermal luminosity of PSR J0205+6449 and RX J0007.0+7302 are indicative of the occurrence of some enhanced neutrino emission beyond the minimal scenario.Comment: Version to appear in ApJ Supplements. Minor modifications in text and discussion of updated data with new figure

THERMAL RADIATION FROM MAGNETIZED NEUTRON STARS: A look at the Surface of a Neutron Star.

Surface thermal emission has been detected by ROSAT from four nearby young neutron stars. Assuming black body emission, the significant pulsations of the observed light curves can be interpreted as due to large surface temperature differences produced by the effect of the crustal magnetic field on the flow of heat from the hot interior toward the cooler surface. However, the energy dependence of the modulation observed in Geminga is incompatible with blackbody emission: this effect will give us a strong constraint on models of the neutron star surface.Comment: 10 pages. tar-compressed and uuencoded postcript file. talk given at the `Jubilee Gamow Seminar', St. Petersburg, Sept. 1994