Miracle-dz/UniFAR-FTUs huggingface dataset:
THE EFFECT OF METALLICITY ON THE DETECTION PROSPECTS FOR GRAVITATIONAL WAVES

Data from the Sloan Digital Sky Survey (∼300,000 galaxies) indicate that recent star formation (within the last 1 billion years) is bimodal: half of the stars form from gas with high amounts of metals (solar metallicity) and the other half form with small contribution of elements heavier than helium (∼10%–30% solar). Theoretical studies of mass loss from the brightest stars derive significantly higher stellar-origin black hole (BH) masses (∼30–80 M☉) than previously estimated for sub-solar compositions. We combine these findings to estimate the probability of detecting gravitational waves (GWs) arising from the inspiral of double compact objects. Our results show that a low-metallicity environment significantly boosts the formation of double compact object binaries with at least one BH. In particular, we find the GW detection rate is increased by a factor of 20 if the metallicity is decreased from solar (as in all previous estimates) to a 50–50 mixture of solar and 10% solar metallicity. The current sensitivity of the two largest instruments to neutron star–neutron star (NS–NS) binary inspirals (VIRGO: ∼9 Mpc; LIGO: ∼18) is not high enough to ensure a first detection. However, our results indicate that if a future instrument increased the sensitivity to ∼50–100 Mpc, a detection of GWs would be expected within the first year of observation. It was previously thought that NS–NS inspirals were the most likely source for GW detection. Our results indicate that BH–BH binaries are ∼25 times more likely sources than NS–NS systems and that we are on the cusp of GW detection.
Observational constraints on the progenitor metallicities of core-collapse supernovae★

We present constraints on the progenitor metallicities of core-collapse supernovae. To date, nearly all metallicity constraints have been inferred from indirect methods such as metallicity gradients in host galaxies, luminosities of host galaxies or derived global galaxy metallicities. Here, progenitor metallicities are derived from optical spectra taken at the sites of nearby supernovae, from the ratio of strong emission lines found in their host H ii regions. We present results from the spectra of 74 host H ii regions and discuss the implications that these have on the nature of core-collapse supernova progenitors. Overall, while we find that the mean metallicity of Type Ibc environments is higher than that of Type II events, this difference is smaller than observed in previous studies. There is only a 0.06 dex difference in the mean metallicity values, at a statistical significance of ∼1. 5σ, while using a Kolmogorov–Smirnov test we find that the two metallicity distributions are marginally consistent with being drawn from the same parent population (probability >10 per cent). This argues that progenitor metallicity is not a dominant parameter in deciding supernovae type, with progenitor mass and/or binarity playing a much more significant role. The mean derived oxygen metallicities [12+log(O/H)] for the different supernova types, on the Pettini & Pagel scale, are 8.580 (standard error on the mean of 0.027) for the 46 Type II supernovae (dominated by Type II plateau), 8.616 (0.040) for 10 Type Ib and 8.626 (0.039) for 14 Type Ic. Overall, the Type Ibc supernovae have a mean metallicity of 8.635 (0.026, 27 supernovae). Hence, we find a slight suggestion of a metallicity sequence, in terms of increasing progenitor metallicity going from Type II through Ib and finally Ic supernovae arising from the highest metallicity progenitors. Finally we discuss these results in the context of all current literature progenitor metallicity measurements, and discuss biases and selection effects that may affect the current sample compared to overall supernova and galaxy samples.
Effects of quark matter nucleation on the evolution of proto-neutron stars

Context. A phase of strong interacting matter with deconfined quarks is expected in the core of a massive neutron star. If this deconfinement phase transition is of the first order, as suggested by many models inspired by quantum chromodynamics, then it will be triggered by the nucleation of a critical size drop of the (stable) quark phase in the metastable hadronic phase. Within these circumstances it has been shown that cold (T = 0) pure hadronic compact stars above a threshold value of their gravitational mass (central pressure) are metastable with respect to the “decay” (conversion) to quark stars (i.e., compact stars made at least in part of quark matter). This stellar conversion process liberates a huge amount of energy (a few 10 53 erg), and it could be the energy source of some of the long gamma ray bursts. Aims. The main goal of the present work is to establish whether a newborn hadronic star (proto-hadronic star) could survive the early stages of its evolution without “decaying” to a quark star. To this aim, we study the nucleation process of quark matter in hot (T 0) β-stable hadronic matter, with and without trapped neutrinos, using a finite temperature equation of state (EOS) for hadronic and quark matter. Methods. The finite-temperature EOS for the hadronic and for the quark phases were calculated using the nonlinear Walecka model and the MIT bag model, respectively. The quantum nucleation rate was calculated making use of the Lifshitz & Kagan nucleation theory. The thermal nucleation rate was calculated using the Langer nucleation theory. Results. We calculate and compare the nucleation rate and the nucleation time due to thermal and quantum nucleation mechanisms. We compute the crossover temperature above which thermal nucleation dominates the finite temperature quantum nucleation mechanism. We next discuss the consequences of quark matter nucleation for the physics and the evolution of proto-neutron stars. We introduce the new concept of limiting conversion temperature and critical mass Mcr for proto-hadronic stars, and we show that protohadronic stars with a mass M < Mcr could survive the early stages of their evolution without decaying to a quark star. We extend the concept of maximum mass of a “neutron star” with respect to the classical one introduced by Oppenheimer & Volkoff to account for the existence of two distinct families of compact stars (hadronic stars and quark stars) as predicted by the present scenario.
Validación del instrumento Trade Policy Sports (TP-SPORTS) para el análisis de la política comercial de los centros y clubs deportivos (Validation of the Trade Policy Sports (TP-SPORTS) instrument for the analysis of the commercial policy of sports centres and clubs)

El deporte ha experimentado una gran evolución a lo largo de los años, hecho que se ha manifestado en un incremento de la práctica deportiva, así como también en un aumento de la oferta de instalaciones deportivas. En mercados cada vez más competitivos, la excelencia en la prestación de servicios juega un papel decisivo. Pese a la importancia de dicha temática, no se han encontrado estudios que evalúen la gestión de la política comercial de los centros y clubs deportivos, y en consecuencia tampoco se han hallado instrumentos válidos para tal fin. Por ello, el objetivo de la presente investigación es validar el instrumento TP-SPORTS: una hoja de registro estructurada en ocho dimensiones y noventa variables que permite analizar la gestión de la política comercial de los centros y clubs deportivos. Para la validación de la misma se ha recurrido a una valoración de juicio de expertos, una evaluación inter e intrapersonal mediante la prueba kappa de Cohen y una prueba piloto con 150 alumnos del grado de Ciencias de la Actividad Física y el Deporte. Tras estos pasos, se puede concluir que el instrumento TP-SPORTS manifiesta ser una herramienta innovadora, a la vez que válida para el análisis de la política comercial de los centros y clubs deportivos de nuestro país. Abstract. Sport has experienced a huge evolution through the years, which is directly reflected on an increase in the population engaged in sport, as well as in the supply of sport facilities. In increasingly competitive markets, excellence in the provision of services plays a decisive role. Despite the importance of this subject, no studies have been found that evaluate the management of the commercial policy of sport centres and clubs and consequently no valid instruments have been found for this purpose. Therefore, the objective of the present research is to validate the TP-SPORTS instrument: a record sheet structured in eight dimensions and ninety variables that allows the analysis of the management of the commercial policy of sports centres and clubs. In order to validate it, an expert judgment assessment, inter and intrapersonal evaluation using Cohen's kappa test and a pilot test with 150 students of the Physical Activity and Sport Sciences degree have been used. In view of the above, it can be concluded that TP-SPORTS instrument proves to be an innovative and valid tool for the analysis of the commercial policy of sports centres and clubs in our country.
Influence of magnetic shear on the current convective instability in the diffuse aurora. Memorandum report

The influence of magnetic shear on the current convective instability is investigated for conditions typical of the high latitude F region during the diffuse aurora. It is found that magnetic shear (1) reduces the growth rate of the instability (although it does not stabilize the mode); and (2) substantially localizes the mode structure parallel to the density gradient.
Determining the heavy seesaw neutrino mass matrix from low-energy parameters

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and $CP$-violating phase observables. The key ingredients are intrafamily symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with interfamily or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.
Selecting Quasar Candidates by a SVM Classification System

We develop and demonstrate a classification system constituted by several Support Vector Machines (SVM) classifiers, which can be applied to select quasar candidates from large sky survey projects, such as SDSS, UKIDSS, GALEX. How to construct this SVM classification system is presented in detail. When the SVM classification system works on the test set to predict quasar candidates, it acquires the efficiency of 93.21% and the completeness of 97.49%. In order to further prove the reliability and feasibility of this system, two chunks are randomly chosen to compare its performance with that of the XDQSO method used for SDSS-III's BOSS. The experimental results show that the high faction of overlap exists between the quasar candidates selected by this system and those extracted by the XDQSO technique in the dereddened i-band magnitude range between 17.75 and 22.45, especially in the interval of dereddened i-band magnitude < 20.0. In the two test areas, 57.38% and 87.15% of the quasar candidates predicted by the system are also targeted by the XDQSO method. Similarly, the prediction of subcategories of quasars according to redshift achieves a high level of overlap with these two approaches. Depending on the effectiveness of this system, the SVM classification system can be used to create the input catalog of quasars for the GuoShouJing Telescope (LAMOST) or other spectroscopic sky survey projects. In order to get higher confidence of quasar candidates, cross-result from the candidates selected by this SVM system with that by XDQSO method is applicable.
Instability of Small Lovelock Black Holes in Even-dimensions

We study the stability of static black holes in Lovelock theory, which is a natural higher dimensional generalization of Einstein theory. We derive a master equation for tensor perturbations in general Lovelock theory. It turns out that the resultant equation is characterized by one functional which determines the background black hole solutions. Thus, the stability issue of static black holes under tensor perturbations in general dimensions is reduced to an algebraic problem. We show that small Lovelock black holes in even-dimensions are unstable.
The Effects of Lengths of Flavin Surfactant N-10-Alkyl Side Chains on Promoting Dispersion of a High-Purity and Diameter-Selective Single-Walled Nanotube

Flavin with defined helical self-assembly helps to understand chemical designs for obtaining high-purity semiconducting (s)-single-walled carbon nanotubes (SWNT) in a diameter (dt)-selective manner for high-end applications. In this study, flavins containing 8, 12, 16, and 20 n-alkyl chains were synthesized, and their single/tandem effects on dt-selective s-SWNT dispersibility were investigated at isomolarity. Flavins with n-dodecyl and longer chain lengths (FC12, FC16, and FC20) act as good surfactants for stable SWNT dispersions whereas n-octyl flavin (FC8) exhibits poor dispersibility owing to the lack of SWNT buoyancy. When used with small-dt SWNT, FC8 displays chirality-selective SWNT dispersion. This behavior, along with various flavin helical motifs, prompts the development of criteria for ‘side chain length (lS)’ required for stable and dt-selective SWNT dispersion, which also explains lS-dependent dt-enrichment behavior. Moreover, SWNT dispersions with flavins with dodecyl and longer lS exhibit increased metallic (m)-SWNT, background absorption-contributing carbonaceous impurities (CIs) and preferential selectivity of s-SWNT with slightly larger dt. The increased CIs that affect the SWNT quantum yield were attributed to a solubility parameter. Furthermore, the effects of flavin lS, sonication bath temperature, centrifugal speed, and surfactant concentration on SWNT purity and s-/m-SWNT ratio were investigated. A tandem FC8/FC12 provides fine-tuning of dt-selective SWNT dispersion, wherein the FC8 ratio governs the tendency towards smaller dt. Kinetic and thermodynamic assemblies of tandem flavins result in different sorting behaviors in which wide dt-tunability was demonstrated using kinetic assembly. This study highlights the importance of appropriate side chain length and other extrinsic parameters to obtain dt-selective or high-purity s-SWNT.
Advances and prospects of orchid research and industrialization

Abstract Orchidaceae is one of the largest, most diverse families in angiosperms with significant ecological and economical values. Orchids have long fascinated scientists by their complex life histories, exquisite floral morphology and pollination syndromes that exhibit exclusive specializations, more than any other plants on Earth. These intrinsic factors together with human influences also make it a keystone group in biodiversity conservation. The advent of sequencing technologies and transgenic techniques represents a quantum leap in orchid research, enabling molecular approaches to be employed to resolve the historically interesting puzzles in orchid basic and applied biology. To date, 16 different orchid genomes covering four subfamilies (Apostasioideae, Vanilloideae, Epidendroideae, and Orchidoideae) have been released. These genome projects have given rise to massive data that greatly empowers the studies pertaining to key innovations and evolutionary mechanisms for the breadth of orchid species. The extensive exploration of transcriptomics, comparative genomics, and recent advances in gene engineering have linked important traits of orchids with a multiplicity of gene families and their regulating networks, providing great potential for genetic enhancement and improvement. In this review, we summarize the progress and achievement in fundamental research and industrialized application of orchids with a particular focus on molecular tools, and make future prospects of orchid molecular breeding and post-genomic research, providing a comprehensive assemblage of state of the art knowledge in orchid research and industrialization.
Menstrual Cycle and Sport: effects on the performance and metabolism of the athlete woman

There are difficulties planning female training. The aim of this meta-analysis work is to know results obtained in studies on the relationship between the menstrual cycle (MC), diet, metabolism and performance in sportswomen. This work began in January-2022 looking differences in performance depending on the MC phase; exclusion criteria after 2015, non-experimental articles with quality indexes >Q2. We finally worked on 11 articles. Perception of the majority of sportswomen is that MC does have an impact on sports performance, as they are affected both physically and psychologically depending on the MC phase. Participant characteristics, such as training history, may also contribute to the variety of responses observed in studies. MC phase where performance may be reduced is in the Early Follicular Phase and may improve in the other MC phases. The effects found maybe of most relevance to female athletes.
Rebalancing of One-Way Car-Sharing Systems Considering Elastic Demand and Waiting Time

This paper studies a vehicle rebalancing problem subject to nonlinear elastic demand and waiting time window for one-way car-sharing systems with charging delay and reservation policy. Firstly, we model the one-way car-sharing system as a mixed Basket-Chandy-Muntz-Palacios (BCMP) queuing network considering: 1) elastic origin-destination demands; 2) passenger waiting time; 3) limited parking and charging facilities; and 4) traffic congestion. Moreover, to maximize the commercial value while achieving a favorable balance between passenger experience and business objectives, a joint rebalancing policy with queue stability control and waiting time constraint is given through combining active balancing performed by passengers and passive rebalancing implemented by operators. Finally, a data-driven simulation based on Chengdu’s Didi dataset is conducted, and the policy comparison and sensitivity analysis are executed to illustrate the performance of the presented method.
Innovative digital technologies in the pr-management specialists training for public administration bodies on the blended learning

Objective. The paper examined the information digital technologies effectiveness in the PR-management specialists training for public administration bodies on the blended learning model. The research methodology is based on a mixed-methods approach and a combination of qualitative and quantitative design to fully cover the use of digital technology in the training of professionals under martial law. Results. It has been demonstrated that through a combination of different digital technologies in the higher education institutions of Ukraine, depending on the stage of training and type of lesson, a flexible inclusive approach was used, making provision for the creation of common standards for teaching through digital technology. Innovative digital technologies were used depending on the stage of the educational process (communication and interaction; conducting lectures and seminars; transferring learning materials and exchanging them; digital content development; knowledge evaluation and academic performance rating). As the higher education institutions of Ukraine significantly improved the asynchronous learning models, the preparation level of both educators and students for the complete transition to asynchronous learning given the war was markedly higher. It is deemed that the flexible self-study model during the war ensures the general competencies development, however students have not mastered a sufficient level of professional practical competencies.
Ship waves on uniform shear current at finite depth: wave resistance and critical velocity

We present a comprehensive theory for linear gravity-driven ship waves in the presence of a shear current with uniform vorticity, including the effects of finite water depth. The wave resistance in the presence of shear current is calculated for the first time, containing in general a non-zero lateral component. While formally apparently a straightforward extension of existing deep water theory, the introduction of finite water depth is physically non-trivial, since the surface waves are now affected by a subtle interplay of the effects of the current and the sea bed. This becomes particularly pronounced when considering the phenomenon of critical velocity, the velocity at which transversely propagating waves become unable to keep up with the moving source. The phenomenon is well known for shallow water, and was recently shown to exist also in deep water in the presence of a shear current (Ellingsen, J. Fluid Mech., vol. 742, 2014, R2). We derive the exact criterion for criticality as a function of an intrinsic shear Froude number $S\sqrt{b/g}$ ( $S$ is uniform vorticity, $b$ size of source), the water depth and the angle between the shear current and the ship’s motion. Formulae for both the normal and lateral wave resistance forces are derived, and we analyse their dependence on the source velocity (or Froude number $Fr$ ) for different amounts of shear and different directions of motion. The effect of the shear current is to increase wave resistance for upstream ship motion and decrease it for downstream motion. Also the value of $Fr$ at which $R$ is maximal is lowered for upstream and increased for downstream directions of ship motion. For oblique angles between ship motion and current there is a lateral wave resistance component which can amount to 10–20 % of the normal wave resistance for side-on shear and $S\sqrt{b/g}$ of order unity. The theory is fully laid out and far-field contributions are carefully separated off by means of Cauchy’s integral theorem, exposing potential pitfalls associated with a slightly different method (Sokhotsky–Plemelj) used in several previous works.
RB49-like Bacteriophages Recognize O Antigens as One of the Alternative Primary Receptors

The power of most of the enterobacterial O antigen types to provide robust protection against direct recognition of the cell surface by bacteriophage receptor-recognition proteins (RBP) has been recently recognized. The bacteriophages infecting O antigen producing strains of E. coli employ various strategies to tackle this nonspecific protection. T-even related phages, including RB49-like viruses, often have wide host ranges, being considered good candidates for use in phage therapy. However, the mechanisms by which these phages overcome the O antigen barrier remain unknown. We demonstrate here that RB49 and related phages Cognac49 and Whisky49 directly use certain types of O antigen as their primary receptors recognized by the virus long tail fibers (LTF) RBP gp38, so the O antigen becomes an attractant instead of an obstacle. Simultaneously to recognize multiple O antigen types, LTFs of each of these phages can bind to additional receptors, such as OmpA protein, enabling them to infect some rough strains of E. coli. We speculate that the mechanical force of the deployment of the short tail fibers (STF) triggered by the LTF binding to the O antigen or underneath of it, allows the receptor binding domains of STF to break through the O polysaccharide layer.