Miracle-dz/UniFAR-FTUs huggingface dataset:
The triangle-free process and R(3,k)

The areas of Ramsey Theory and Random Graphs have been closely linked every since Erd\H{o}s' famous proof in 1947 that the 'diagonal' Ramsey numbers R(k) grow exponentially in k. In the early 1990s, the triangle-free process was introduced as a model which might potentially provide good lower bounds for the 'off-diagonal' Ramsey numbers R(3,k). In this model, edges of K_n are introduced one-by-one at random and added to the graph if they do not create a triangle; the resulting final (random) graph is denoted G_{n,\triangle}. In 2009, Bohman succeeded in following this process for a positive fraction of its duration, and thus obtained a second proof of Kim's celebrated result that R(3,k) = \Theta (k^2 / log k). In this paper we improve the results of both Bohman and Kim, and follow the triangle-free process all the way to the end. In particular, we shall prove that e(G_{n,\triangle}) = (1 / 2\sqrt{2} + o(1)) n^{3/2} \sqrt{log n}, with high probability as n \to \infty. We also obtain several 'pseudo-random' properties of G_{n,\triangle}, and use them to bound its independence number, which gives as an immediate corollary R(3,k) \ge (1/4 - o(1)) k^2 / log k. This significantly improves Kim's lower bound, and is within a factor of 4 + o(1) of the best known upper bound, proved by Shearer over 25 years ago. Similar results have been proved independently by Bohman and Keevash.
The effect of whole-body vibration on spasticity in post-stroke hemiplegia: A prospective, randomized-controlled study

Objectives This study aims to investigate whether whole-body vibration (WBV) has an anti-spastic effect on the ankle plantar flexors. Patients and methods This single-blind, prospective, randomized-controlled clinical study included a total of 48 patients with chronic stroke (33 males, 15 females; mean age: 60.7±10.9 years; range, 25 to 80 years) between May 2019 and February 2020. They were randomized into two groups: WBV group (n=24) and sham WBV group (n=24). A training program of 12 sessions (three days a week for four weeks) was applied regularly in both groups. The spasticity degree of the plantar flexors was evaluated by using both a subjective assessment method (modified Ashworth scale [MAS]) and several objective assessment methods (Hmax/Mmax, homosynaptic post-activation depression [HPAD], and torque) before and after the training program. Results There were no significant changes in the torque values, Hmax/Mmax, and HPAD level after the training program in both groups (p>0.05). However, the MAS score in the WBV group significantly decreased (-9.0%), but no change in the control group was observed (0.7%) (p=0.027, effect size = 0.32). Conclusion The objective assessment methods for spasticity show that WBV has no anti-spastic effect.
Single-Cell Transcriptome Analysis Reveals Paraspeckles Expression in Osteosarcoma Tissues

Nuclear paraspeckles are subnuclear bodies contracted by nuclear-enriched abundant transcript 1 (NEAT1) long non-coding RNA, localised in the interchromatin space of mammalian cell nuclei. Paraspeckles have been critically involved in tumour progression, metastasis and chemoresistance. To this date, there are limited findings to suggest that paraspeckles, NEAT1 and heterogeneous nuclear ribonucleoproteins (hnRNPs) directly or indirectly play roles in osteosarcoma progression. Herein, we analysed NEAT1, paraspeckle proteins (SFPQ, PSPC1 and NONO) and hnRNP members (HNRNPK, HNRNPM, HNRNPR and HNRNPD) gene expression in 6 osteosarcoma tumour tissues using the single-cell RNA-sequencing method. The normalised data highlighted that the paraspeckles transcripts were highly abundant in osteoblastic OS cells, except NEAT1, which was highly expressed in myeloid cell 1 and 2 subpopulations.
Carbon Emissions in the U.S.: Factor Decomposition and Cross-State Inequality Dynamics

This paper examines the determinants of inequality in the distribution of CO2 emissions across U.S. regions. We implement a factorial decomposition of CO2 per capita based on extended Kaya factors, that is, carbon intensity of fossil fuel consumption, energy mix, energy intensity of GDP, economic growth in terms of labor productivity and employment rate. Results reveal that U.S. states display marked differences in most factors. We identify energy intensity as the main source of emissions inequality. Based on the within and between group inequality components we also explore the effect of geographical, geological, climatic and human development partitions of U.S. states’ groups. Findings indicate that the within-group inequality had been the main contributor to the whole inequality. Finally, some economic policy implications are also discussed; explaining the unequal distribution of emissions is vital to establish differentiated targets and work towards successful mitigation proposals.
Quantifying the optical properties and chromophore concentrations of turbid media using polarization sensitive hyperspectral imaging: optical phantom studies

We present a polarization-sensitive hyperspectral imaging system (SkinSpect) that employs a spectrally-programmable light source in the visible and NIR domains. Multiple tissue-mimicking phantoms were fabricated to mimic the optical properties of normal skin as well as pigmented light and dark moles. The phantoms consist of titanium dioxide and a mixture of coffee, red food dye, and naphthol green as the scattering and the three absorptive agents in a polydimethylsiloxane (PDMS) base. Phantoms were produced with both smooth and rough textured surfaces and tested using Spatial Frequency Domain Imaging (SFDI) and Spatially Modulated Quantitative Spectroscopy (SMoQS) for homogeneity as well as determining absorption and scattering variance, respectively. The reflectance spectral images were also recorded using the SkinSpect research prototype; the spectral signatures of the phantoms were calculated using a two-flux single-layer Kubelka-Munk model and non-negative least square fitting routine was applied to extract the relative concentrations of the individual phantom components.
The BEST PATHS P roject on MgB 2 Superconducting Cables for Very High P ower T ransmission

BEST PATHS (acronym for “BEyond State-of-theart Technologies for rePowering Ac corridors and multiTerminal HVDC Systems”) is a collaborative project within the FP7 framework of the European Commission that includes an MgB2-based power transmission line among its five constituent demonstrators. Led by Nexans and bringing together transmission operators, industry and research organizations, this demonstrator aims at validating the novel MgB2 technology for very high power transfer (gigawatt range). The project foresees the development of a monopole cable system operating in helium gas in the range 5–10 kA/200–320 kV, corresponding to a transmitted power from 1 to 3.2 GW. The main research and demonstration activities that will be pursued over the four-year project duration are: 1) development and manufacturing of MgB2 wires and of the cable conductor; 2) design and manufacturing of the HVDC electrical insulation of the cable; 3) optimization of the required cryogenic system; 4) electromagnetic field analysis; 5) design and construction of a prototype electrical feeding system including terminations and connectors; 6) testing of the demonstrator; 7) study of grid connection procedures and integration of a superconducting link into a transmission grid; and finally, 8) a socio-economic analysis of the MgB2 power transmission system. CIGRÉ recommendations will be used to take into account the established international practices, and guidance will be given on newly addressed technical aspects. An overview of the project is presented in the paper, including the main tasks and challenges ahead, as well as the partners and their roles.
Effect of Atmospheric Conditions on Pathogenic Phenotypes of Arcobacter butzleri

Arcobacter butzleri is an emergent gram-negative enteropathogenic bacterium widespread in different environments and hosts. During the colonization of the gastrointestinal tract, bacteria face a variety of environmental conditions to successfully establish infection in a new host. One of these challenges is the fluctuation of oxygen concentrations encountered not only throughout the host gastrointestinal tract and defences but also in the food industry. Oxygen fluctuations can lead to modulations in the virulence of the bacterium and possibly increase its pathogenic potential. In this sense, eight human isolates of A. butzleri were studied to evaluate the effects of microaerobic and aerobic atmospheric conditions in stressful host conditions, such as oxidative stress, acid survival, and human serum survival. In addition, the effects on the modulation of virulence traits, such as haemolytic activity, bacterial motility, biofilm formation ability, and adhesion and invasion of the Caco-2 cell line, were also investigated. Overall, aerobic conditions negatively affected the susceptibility to oxygen reactive species and biofilm formation ability but improved the isolates’ haemolytic ability and motility while other traits showed an isolate-dependent response. In summary, this work demonstrates for the first time that oxygen levels can modulate the potential pathogenicity of A. butzleri, although the response to stressful conditions was very heterogeneous among different strains.
A Post-Processing Technique and an a Posteriori Error Estimate for the Newmark Method in Dynamic Analysis

In this paper, we present a post-processing technique and an a posteriori error estimate for the Newmark method in structural dynamic analysis. By post-processing the Newmark solutions, we derive a simple formulation for linearly varied third-order derivatives. By comparing the Newmark solutions with the exact solutions expanded in the Taylor series, we achieve the local post-processed solutions which are of fifth-order accuracy for displacements and fourth-order accuracy for velocities in one step. Based on the post-processing technique, a posteriori local error estimates for displacements, velocities and, thus, also the total energy norm error estimate are obtained. If the Newmark solutions are corrected at each step, the post-processed solutions are of third-order accuracy in the global sense, i.e. one-order improvement for the original Newmark solutions is achieved. We also discuss a method for estimating the global time integration error. We find that, when the total energy norm is used, the sum of the local error estimates will give a reasonable estimate for the global error. We present numerical studies on a SDOF and a 2-DOF example in order to demonstrate the performance of the proposed technique.
The generalized perpetual American exchange-option problem

This paper revisits a general optimal stopping problem that often appears as a special case in some finance applications. The problem is essentially of the same form as the investment-timing problem of McDonald and Siegel (1986) in which the underlying processes are two correlated geometric Brownian motions (GBMs) with drifts less than the discount rate. By contrast, we attempt to analyze the underlying optimal stopping problem to its full generality without imposing any restriction on the drifts of the GBMs. By extending the first passage time approach of Xia and Zhou (2007) to the current context, we manage to obtain a complete and explicit characterization of the solution to the problem on all possible drift domains. Our analysis leads to a new and interesting observation that the underlying optimal stopping problem admits a two-sided optimal continuation region on some certain parameter domains.
Byzantine Resilient Locally Optimum Radioactive Source Detection Using Collaborative Sensor Networks

In this paper, we propose a locally optimum detection (LOD) scheme for detecting a weak radioactive source buried in background clutter. We develop a decentralized algorithm, based on alternating direction method of multipliers (ADMM), for implementing the proposed scheme in autonomous sensor networks. Results show that algorithm performance approaches the centralized clairvoyant detection algorithm in the low SNR regime, and exhibits excellent convergence rate and scaling behavior (w.r.t. number of nodes). We also devise a low-overhead, robust ADMM algorithm for Byzantine-resilient detection, and demonstrate its robustness to data falsification attacks. Keywords—locally optimum detection, data falsification, Byzantines, autonomous networks, ADMM
Développement de détecteurs Micromegas pixellisés pour les hauts flux de particules et évaluation de la contribution diffractive à la leptoproduction de hadrons à COMPASS

Le travail presente dans cette these porte d’une part sur le developpement et la caracterisation d’une nouvelle generation de detecteurs Micromegas (MICROMEsh GAseous Structure) pour l’experience COMPASS au Cern, et d’autre part sur l’estimation de la contribution de canaux diffractifs a la production de pions et de kaons, dans le cadre de l’etude des fonctions de fragmentation de quarks en hadrons a COMPASS. De nouveaux detecteurs Micromegas d’une surface active de 40 x 40 cm² sont en cours de developpement pour le futur de l’experience COMPASS, a partir de 2015. Ces detecteurs devront fonctionner dans des flux de muons et hadrons approchant 8 MHz/cm². Pour cela, une zone centrale d’environ 5 cm de diametre, traversee par le faisceau, sera constituee de 1280 pixels, et des technologies permettant de fortement reduire l’impact des decharges seront adoptees. Quatre prototypes de geometrie finale utilisant deux types de technologies de reduction des decharges differentes ont ete produits au Cern et testes en conditions reelles a COMPASS entre 2010 et 2012. Trois d’entre eux sont des detecteurs hybrides utilisant une feuille GEM (Gas Electron Multiplier) en tant qu’etage de preamplification pour reduire la probabilite de decharge. Le dernier detecteur est equipe d’une structure resistive a « resistances enterrees », permettant la reduction de l’amplitude des decharges. Leurs performances sont presentees dans cette these. L’impact de ces resultats sur la production et la mise en œuvre de la serie finale de detecteurs est egalement discute. Les fonctions de fragmentation de quarks en hadrons l’hadronisation d’un quark de saveur q en un hadron h. Ces fonctions universelles interviennent dans l’expression de la section efficace de nombreux processus. Elles sont accessibles a COMPASS via la reaction de diffusion profondement inelastique semi-inclusive de muons sur des nucleons. Les observables permettant leur extraction dans ce cadre sont les multiplicites de hadrons, soit le nombre moyen de hadrons produits par evenement de diffusion profondement inelastique. Les mesons vecteurs issus de processus diffractifs produisent egalement des pions et kaons par leur desintegration. Ces processus n’impliquant pas l’hadronisation d’un quark, il semble justifie de ne pas les comptabiliser dans la mesure des multiplicites. Ce travail propose une etude Monte-Carlo des contributions de la production diffractive de mesons vecteurs rho et phi a la production de hadrons leger et aux evenements inclusifs. Des facteurs de correction des multiplicites sont finalement etablis. Enfin, l’effet de cette correction sur l’extraction des fonctions de fragmentation en pions est presente.
The stability of obliquely-propagating solitary-wave solutions to Zakharov–Kuznetsov-type equations

In certain circumstances, small amplitude, weakly nonlinear ion-acoustic waves in a magnetized plasma are governed by a Zakharov–Kuznetsov equation or by a reduced form of the equation. Both equations have a plane solitary travelling-wave solution that propagates at an angle αto the magnetic field. The multiple-scale perturbation method developed by Allen and Rowlands is used to calculate the initial growth rate of a small, transverse, long-wavelength perturbation to these solitary-wave solutions. Previous results in the literature are corrected. A numerical determination of the growth rate is given. For k[mid ] secα[mid ][Lt ]1, where k is the wavenumber of the perturbation, there is excellent agreement between our analytical and numerical results.
Nanosecond Square Pulse Fiber Laser based on the Nonlinear Amplifying Loop Mirror

We propose and demonstrate a nanosecond square pulse ytterbium doped fiber laser in the 1060nm band. The laser is based on the figure-8 structure and has a tunable pulse bandwidth from 3 ns to beyond 100 ns, showing excellent temporal tuning ability. The experimental results show that a steady square pulse can be generated when the parameters of the cavity are chosen appropriately.
Hybrid states of Tamm plasmons and exciton polaritons

Channeling of exciton polaritons in the plane of semiconductor microcavities can be achieved by the deposition of metallic mesas on the top of the semiconductor structure. We show theoretically that the regime of strong coupling between cavity polaritons and Tamm surface plasmons is possible in such structures. The effect is favorable for the spatial confinement of polaritons and the formation of hybrid one-dimensional plasmon-polariton modes.
AP and ABR tuning curves: A comparative study

Whole‐nerve action potential (AP) and auditory brain‐stem response (ABR) were recorded from anesthetized eats. Response amplitude and latency to a probe stimulus were measured and tuning curves were constructed using three masking paradigms; forward, simultaneous (a tone burst masker overlapping the probe), and continuous (a continuous masker tone). AP and ABR tuning curves were generated on the basis of criterion changes in both amplitude and latency of the response. Within each of the masking techniques, tuning curves developed from the amplitude and latency criterion changes of the AP and the ABR showed no significant differences. The only significant differences were measured across masking conditions. Forward masking tuning curves were found to have steeper high‐frequency slopes, higher Q 10 values, and lower sensitivity indicies (defined as the difference between probe level and the level at the tip of the tuning curve). Low‐frequency slopes and the tip‐to‐tail ratios showed no significant differenc.
Small-angle scattering and diffraction experiments in biology and physics employing synchrotron radiation and energy-dispersive techniques

Small-angle scattering and diffraction experiments using the continuum of X-rays provided by synchrotron radiation and energy-dispersive techniques are discussed. An analysis of the characteristics of the method backed with experimental results obtained from fibres (muscle and collagen) and proteins (catalase, myoglobin, bovine serum albumin and ferritin) in solution has been made. The presentation includes: characteristics of experimental layout, theory and intensity analysis, resolution, scattering-vector range, absorption problems, speed of data collection and radiation damage effects. Some suggestions for future developments are also put forward.
Brown Macroalgae Sargassum cristaefolium Extract Inhibits Melanin Production and Cellular Oxygen Stress in B16F10 Melanoma Cells

The brown macroalgae Sargassum has been reported for its anti-UV and photoprotective potential for industrial applications. This study evaluated the melanin inhibition activity of Sargassum cristaefolium (SCE) ethanol extract. Melanogenesis inhibition by SCE was assessed in vitro with B16-F10 melanoma cell models and in silico against melanin regulatory proteins Tyrosinase (TYR) and Melanocortin 1 Receptor (MC1R). The regulatory properties evaluated were the melanin content, intracellular tyrosinase activity and cellular antioxidant activities. In addition, the bioactive compounds detected in SCE were subjected to molecular docking against TYR and MC1R. Based on the results, 150 µg/mL SCE effectively inhibited the production of melanin content and intracellular tyrosinase activity. Cellular tyrosinase activity was reduced by SCE-treated cells in a concentration-dependent manner. The results were comparable to the standard tyrosinase inhibitor kojic acid. In addition, SCE effectively decreased the intracellular reactive oxygen species (ROS) levels in B16-F10 cells. The antioxidant properties may also contribute to the inhibition of melanogenesis. In addition, LCMS UHPLC-HR-ESI-MS profiling detected 33 major compounds. The results based on in silico study revealed that the bioactive compound putative kaurenoic acid showed a strong binding affinity against TYR (−6.5 kcal/mol) and MC1R (−8.6 kcal/mol). However, further molecular analyses are needed to confirm the mechanism of SCE on melanin inhibition. Nevertheless, SCE is proposed as an anti-melanogenic and antioxidant agent, which could be further developed into cosmetic skin care products.
Ion entry into the wake behind a nonmagnetized obstacle in the solar wind: Two‐dimensional particle‐in‐cell simulations

The ion entry into the wake behind an obstacle in the solar wind is studied using two‐dimensional, electromagnetic full‐particle simulations. A significant difference is found between the number of ions and electrons in the near wake, mainly due to the negative electric charge on the nightside surface of the obstacle. The ion acceleration toward the void is observed far from the position of the rarefaction wave expected in the self‐similar solution. The velocity profile of the ions in the wake approaches the self‐similar solution with finite ion temperature asymptotically until they reach the distance where the ions from both sides of the wake meet. The ions that entered from both sides are accelerated in the opposite directions. They raise the ion temperature and the pressure in the center of the wake, although each component remains cool when treated separately. The electron temperature appears nearly constant, except for the edge of the complete void of electrons. The large‐scale obstacle and a slow solar wind are favorable conditions for a detection of well‐accelerated ions near the nightside surface of the obstacle, because they have enough time to accelerate. The direction of the electric field in the wake seems consistent with the gradient of the electron pressure.
Stiffness and thickness of the upper trapezius muscle increase after repeated climbing bouts in male climbers

Background Indoor climbing involves overloading the shoulder girdle, including the rotator cuff and upper trapezius muscles. This on the field study aimed to investigate the effects of repeated climbing bouts on morphological and mechanical measures of the upper trapezius muscle. Materials and Methods Fifteen experienced male climbers participated in the study. Rate of perceived exertion (RPE), blood lactate concentration ([La−]b), and stiffness and thickness over four points of the upper trapezius were assessed before and after a repeated climbing exercise. The procedure for the climbing exercise consisted of five climbs for a total time of 5-minutes per climb, followed by a 5-minute rest. Results The analysis showed an increase from baseline to after the 3rd climb (p ≤ 0.01) for RPE and after the 5th climb for [La−]b (p ≤ 0.001). Muscle stiffness and thickness increased at all points (1–2–3–4) after the 5th climb (p ≤ 0.01). We found spatial heterogeneity in muscle stiffness and thickness; muscle stiffness was the highest at Point 4 (p ≤ 0.01), while muscle thickness reached the highest values at points 1–2 (both p ≤ 0.01). Moreover, the analysis between the dominant and non-dominant shoulder showed greater stiffness after the 1st climb at Point 1 (p = 0.004) and after the 5th climb at Point 4 (p ≤ 0.001). Conclusions For muscle thickness, the analysis showed significant changes in time and location between the dominant and the non-dominant shoulder. Bilateral increases in upper trapezius muscle stiffness and thickness, with simultaneous increases in RPE and blood lactate in response to consecutive climbs eliciting fatigue.