Miracle-dz/UniFAR-FTUs huggingface dataset:
Revisiting Simple Regret: Fast Rates for Returning a Good Arm

Simple regret is a natural and parameter-free performance criterion for pure exploration in multi-armed bandits yet is less popular than the probability of missing the best arm or an $\epsilon$-good arm, perhaps due to lack of easy ways to characterize it. In this paper, we make significant progress on minimizing simple regret in both data-rich ($T\ge n$) and data-poor regime ($T \le n$) where $n$ is the number of arms, and $T$ is the number of samples. At its heart is our improved instance-dependent analysis of the well-known Sequential Halving (SH) algorithm, where we bound the probability of returning an arm whose mean reward is not within $\epsilon$ from the best (i.e., not $\epsilon$-good) for \textit{any} choice of $\epsilon>0$, although $\epsilon$ is not an input to SH. Our bound not only leads to an optimal worst-case simple regret bound of $\sqrt{n/T}$ up to logarithmic factors but also essentially matches the instance-dependent lower bound for returning an $\epsilon$-good arm reported by Katz-Samuels and Jamieson (2020). For the more challenging data-poor regime, we propose Bracketing SH (BSH) that enjoys the same improvement even without sampling each arm at least once. Our empirical study shows that BSH outperforms existing methods on real-world tasks.
On the widths of $\eta(1295)$ and $\eta(1405/1475)$

Based on the assignment of the first radial excitation states of the isoscalar pseudoscalars for $\eta(1295)$ and $\eta(1405/1475)$, we investigate their three-body and four-body decay contributions to the total widths. In agreement with our previous studies we find that the triangle singularity (TS) mechanism arising from the intermediate $K^*\bar{K}$ rescatterings by exchanging a kaon or pion plays a crucial role in both $K\bar{K}\pi$ and $\eta\pi\pi$ channels. For the $\eta_X$ ($\eta_X$ stands for $\eta(1295)$ and $\eta(1405/1475)$) decays into $K\bar{K}\pi$, we find that although the transition $\eta_X\to K^*\bar{K}+c.c. \to K\bar{K}\pi$ is the dominant tree-level process, the productions of the intermediate $K\bar{\kappa}+c.c. $ and $a_0(980)\pi$ are strongly enhanced by the TS mechanism. For the $\eta_X$ decays into $\eta\pi\pi$, we find that the production of the intermediate $a_0(980)\pi$ via the triangle transition is the dominant one for $\eta(1295)$ partly because of the large $\eta(1295)K^*\bar{K}$ coupling. In contrast, the tree-level and triangle loop contributions are compatible and dominant in the $\eta(1405/1475)$ decays into $\eta\pi\pi$. It shows that a combined analysis is useful for disentangling the underlying dynamics for these two states.
Spectral evolution of the extremely fast classical nova V838 Herculis

Spectral evolution of nova V838 Her 1991 was monitored at Asiago Astrophysical Observatory from 1991 March 31 to July 2. The spectra in the early decline stage showed emission lines of H I, He I, He II, N II, N III, C II, C III, C IV, Si II, [S III], [Ne III], and Fe II, where some identifications are different from those reported in the previous works. The emission lines of [Ne III] and carbon ions were unusually intense. New emission peaks appeared at the blue-ward edges of the emission lines of H I and He I about one week after maximum luminosity. It seems that a new clump of gas was ejected at that time along the line of sight towards us. The helium abundance is estimated at N(He) = 0.11 ± 0.01.
Eigenvalue Asymptotics in Isothermal Forced Elongation

In this paper, we consider the formal linearization of the governing equations of forced elongation in the isothermal regime. We give an asymptotic characterization of the spectrum of the associated strongly continuous semigroup. To this end, we develop rigorous asymptotic techniques to determine the asymptotic behavior of the eigenvalues by solving a characteristic integral equation in a generalized sector of the complex plane. The spectral mapping theorem, relating the spectrum of the semigroup to the spectrum of its generator, proves essential. Numerical evidence will be given to demonstrate the accuracy of our asymptotic predictions.
Contrast-Enhanced Ultrasound and Strain Elastography for Differentiating Benign and Malignant Parotid Tumors

Abstract Objectives Preoperative differentiation between benign parotid tumors (BPT) and malignant parotid tumors (MPT) is crucial for treatment decisions. The purpose of this study was to investigate the benefits of combining contrast-enhanced ultrasound (CEUS) and strain elastography (SE) for preoperative differentiation between BPT and MPT. Methods A total of 115 patients with BPT (n=72) or MPT (n=43) who underwent ultrasound (US), SE, and CEUS were enrolled. US and CEUS features and the elasticity score were evaluated. Receiver operating characteristic curve (ROC) analysis was used to assess the diagnostic performance of SE, CEUS, and SE + CEUS with respect to identifying MPT from BPT. Results Solitary presentation, larger diameter, irregular shape, ill-defined margin, heterogeneous echogenicity, and calcification on US and higher elasticity score on SE had a significant association with malignancy. MPT also presented an unclear margin, larger size after enhancement, and “fast-in and fast-out” pattern on CEUS. The combination of SE and CEUS was effective for differentiating MPT from BPT (AUC: 0.88, 0.80–0.95), with a sensitivity of 86.0%, specificity of 88.9%, and accuracy of 87.8%, which were significantly higher than the values for SE (AUC: 0.75, 0.66–0.85) and CEUS (AUC: 0.82, 0.73–0.91) alone. Conclusion The combination of CEUS and SE is valuable for distinguishing MPT from BPT.
Numerical Investigation of MILD Combustion Using Multi-Environment Eulerian Probability Density Function Modeling

In the present paper, the flames imitating Moderate and Intense Low Oxygen Dilution (MILD) combustion are studied using the Probability Density Function (PDF) modeling approach. Two burners which imitate MILD combustion are considered for the current study: one is Adelaide Jet-in-Hot-Coflow (JHC) burner and the other one is Delft-Jet-In-Hot-Coflow (DJHC) burner. 2D RANS simulations have been carried out using Multi-environment Eulerian Probability Density Function (MEPDF) approach along with the Interaction-by-Exchange-with-Mean (IEM) micro-mixing model. A quantitative comparison is made to assess the accuracy and predictive capability of the MEPDF model in the MILD combustion regime. The computations are performed for two different jet speeds corresponding to Reynolds numbers of Re = 4100 and Re = 8800 for DJHC burner, while Re = 10000 is considered for the Adelaide burner. In the case of DJHC burner, for Re = 4100, it has been observed that the mean axial velocity profiles and the turbulent kinetic energy profiles are in good agreement with the experimental database while the temperature profiles are slightly over-predicted in the downstream region. For the higher Reynolds number case (Re = 8800), the accuracy of the predictions is found to be reduced. Whereas in the case of Adelaide burner, the computed profiles of temperature and the mass fraction of major species (CH4, H2, N2, O2) are found to be in excellent agreement with the measurements while the discrepancies are observed in the mass fraction profiles of CO2 and H2O. In addition, the effects of differential diffusion are observed due to the presence of H2 in the fuel mixture.
Social Media and Press Freedom

Abstract As internet penetration rapidly expanded throughout the world, press freedom and government accountability improved in some countries but backslid in others. We propose a formal model that provides a mechanism that explains the observed divergent paths of countries. We argue that increased access to social media makes partial capture, where governments allow limited freedom of the press, an untenable strategy. By amplifying the influence of small traditional media outlets, higher internet access increases both the costs of capture and the risk that a critical mass of citizens will become informed and overturn the incumbent. Depending on the incentives to retain office, greater internet access thus either forces an incumbent to extend capture to small outlets, further undermining press freedom; or relieve pressure from others. We relate our findings to the cases of Turkey and Tunisia.
Testing of Daubenton's Bat (Myotis daubentonii) Droppings for Field Behavioural Endocrinology

Measurement of faecal hormonal metabolites has become a widespread method in field endocrinology due to its non-invasiveness and ability to assess long-term stress; however, this approach has some limitations. We tested the potential of this assay for the Daubenton's bat (Myotis daubentonii), a small vespertilionid species (body mass 6–10 g), and we explored the relationship between cortisol and testosterone levels and dawn swarming, a signalling behaviour that occurs during roost-switching. Swarming was recorded using automated PIT-tag readers on the tree roosts of a maternity colony. In spite of absence of biological validation, our preliminary results demonstrate that field conditions of sample storage and small faeces weight do not interfere with hormonal measurement. We also found a positive correlation between individual levels of stress hormone (cortisol faecal metabolites) and swarming behaviour, but this should be interpreted with caution due to methodological shortcomings that need to be improved in future studies.
Temporal Variations among the Growth Parameters of the Forearms of Juvenile Greater Horseshoe Bats (Rhinolophus ferrumequinum) in the Nursery Roost at Stackpole, West Wales, U.K.

We addressed the question of why juvenile R. ferrumequinum that are born early (May to early June) in the nursery roost at Stackpole, West Wales, tend to have a higher forearm growth rate than individuals born later (late June to July). An appropriate nonlinear growth equation (either logistic, Gompertz, von-Bertalanffy, or asymptotic regression) was identified to fit the measurements of the forearms of juvenile R. ferrumequinum collected from marked individuals at the roost between 1994 and 2013. The logistic growth model provided the best line of fit to the changes in the forearm lengths, indicated by the lowest standard error. Over the 20-year study period, the mean values of the logistic growth parameters were asymptotic length (L∞) = 55.10 mm and growth constant (K) = 0.11 day-1. Multiple regression analysis indicated that the most significant predictors of the variance in L∞ and K (R2 = 58.7% and 54.3%, respectively) were the nursery roost temperatures at midnight, and the total foraging times of the adult bats during the night. If the juveniles were born early, when the roost temperature was colder, and the foraging times of the adults were shorter, then a lower value of K produced forearms that grew toward a longer L∞. If the juveniles were born late, when the roost temperature was warmer, and the foraging times of the adults were longer, then a higher value of K produced forearms that grew toward a shorter L∞. Reasons are proposed to explain the differences between the growth of early and late born individuals, including the effect of increased body mass associated with warmer roost temperatures and possible causes of longer foraging times.
Simultaneous translational and rotational Brownian movement of particles of arbitrary shape

The coupling of the translational and rotational Brownian motion of a particle due to its arbitrary geometric shape is studied. The generalized kinetic equation for the Brownian particle distribution function is derived from the Liouville equation. The correlation functions for random force and torque are calculated from hydrodynamic fluctuation theory. It is found that the coupling effect plays an appreciable role in the diffusivities of asymmetric particles. For the special case of a sphere where there is no coupling, the autocorrelation function for the random torque in rotational Brownian motion is given in closed from. Its asymptotic from at large times is proportional to (time)−5/2. As an example of an asymmetric particle, the diffusivity tensor is worked out for two disks connected by a rigid rod.
Plasma formation and structural modification below the visible ablation threshold in fused silica upon femtosecond laser irradiation

We have investigated the temporal and spatial evolution of the ablation process induced in fused silica upon irradiation with single 120fs laser pulses at 800nm. Time-resolved microscopy images of the surface reflectivity at 400nm reveal the existence of a transient plasma distribution with annular shape surrounding the visible ablation crater. The material in this annular zone shows an increased reflectivity after irradiation, consistent with a local refractive index increase of approximately 0.01. White light interferometry measurements indicate a shallow surface depression in this outer region, most likely due to material densification.
Discovery of a cyclotron absorption line in the spectrum of the binary X-ray pulsar 4U 1538 - 52 observed by Ginga

A cyclotron absorption line near 20 keV has been found in the spectrum of the massive eclipsing binary X-ray pulsar 4U 1538 - 52 in observations with the Ginga observatory. The line is detected throughout the 529 s pulse cycle with a variable equivalent width that has its maximum value during the smaller peak of the two-peak pulse profile. It is found that the profile of the pulse and the phase-dependence of the cyclotron line can be explained qualitatively by a pulsar model based on recent theoretical results on the properties of pencil beams emitted by accretion-heated slabs of magnetized plasma at the magnetic poles of a neutron star. The indicated field at the surface of the neutron star is 1.7 (1 + z) x 10 to the 12th G, where z is the gravitational redshift. 37 refs.
Optimization of apigenin nanoparticles prepared by planetary ball milling: In vitro and in vivo studies

Abstract This study intended to optimize apigenin (APG) nanoparticle formulation prepared by planetary ball milling to enhance its dissolution rate and bioavailability using a design of experiment (DoE). In this study, polyvinyl pyrrolidone (PVP K30) was used as a nanoparticle stabilizer. The independent parameters of milling speed, milling ball size, and drug to solvent ratio were evaluated for their impacts on APG nanoparticles concerning the nanoparticle size (Y1), zeta potential (Y2), and drug dissolution efficiency after 60 min, notated as % DE60 (Y3). The milling ball size showed a significant antagonistic effect (P = 0.0210) on the size of APG nanoparticles, while milling speed had an agonistic effect on the zeta potential values of drug nanoparticles, ranging from low to medium speed levels. In addition, ANOVA analysis indicated that the effect of the drug-to-solvent ratio on the % DE60 of APG from the nanoparticle formulations was antagonistically significant (P = 0.015), and the quadratic effect of milling speed (AA) also had a significant antagonistic effect (P = 0.025) on the % DE60. Risk assessment analytical tools revealed that milling ball size and milling speed significantly affect the nanoparticle size. The drug/solvent ratio exerted a strong impact on % DE60. Furthermore, the maximum plasma concentration (C max) of the optimized APG nanoparticle formula increased by four folds. In addition, AUC0–t (ng·mL−1·h−1) for APG nanoparticle (353.7 ± 185.3 ng·mL−1·h−1) was higher than that noticed in the case of the untreated drug (149 ± 137.5 ng·mL−1·h−1) by more than two folds.
Abundance trends for river macroinvertebrates vary across taxa, trophic group and river typology

There is mounting evidence that terrestrial arthropods are declining rapidly in many areas of the world. It is unclear whether freshwater invertebrates, which are key providers of ecosystem services, are also declining. We addressed this question by analysing a long‐term dataset of macroinvertebrate abundance collected from 2002 to 2019 across 5009 sampling sites in English rivers. Patterns varied markedly across taxonomic groups. Within trophic groups we detected increases in the abundance of carnivores by 19% and herbivores by 14.8%, while we estimated decomposers have declined by 21.7% in abundance since 2002. We also found heterogeneity in trends across rivers belonging to different typologies based on geological dominance and catchment altitude, with organic lowland rivers having generally higher rates of increase in abundance across taxa and trophic groups, with siliceous lowland rivers having the most declines. Our results reveal a complex picture of change in freshwater macroinvertebrate abundance between taxonomic groups, trophic levels and river typologies. Our analysis helps with identifying priority regions for action on potential environmental stressors where we discover macroinvertebrate abundance declines.
Cost Optimization for Cloud Storage from User Perspectives: Recent Advances, Taxonomy, and Survey

With the development and maturity of cloud storage, it has attracted a large number of users. Although cloud users do not need to concern themselves with the infrastructure used for storage, thus saving on equipment and maintenance costs, the sheer volume of data still generates significant cloud storage usage costs, which motivates cloud storage users to look for ways to further save costs. In this article, we analyze the whole process of using cloud storage to exhaustively explore opportunities, motivations, and challenges of cost optimization from user perspectives. Then we provide a comprehensive taxonomy and summary of recent advances in terms of storage efficiency (i.e., cost optimization by improving storage efficiency), cloud storage services (i.e., cost optimization by leveraging the features of cloud storage services), and emerging storage paradigms (i.e., cost optimization by leveraging emerging storage paradigms like edge storage). Finally, we present future directions for cost optimization from user perspectives and present our conclusion. This article offers a thorough survey of recent advances focusing on how to optimize the cost of using cloud storage for cloud users, and it has an opportunity to attract a broad audience in the cost-effective cloud storage market.
GNOM-Dependent Endosomal Recycling Sets the Timing of Founder Cell Specification

Lateral root growth occurs from primed xylem pole pericycle cells that can be specified as founder cells, but how these cells acquire the pluripotency state to initiate a root organogenesis program is not fully understood. Here, we find that the EMS 204 mutant is unable to specify founder cells due to a point mutation affecting the C-terminal HDS3 domain of the GNOM protein. We used genetics and cell biology to study the trafficking machinery of xylem pole pericycle cells, cells in which GNOM is primarily associated with recycling endosomes. We found that the lack of the HDS3 domain negatively affects the stability of the GNOM protein within the cells of the xylem pole pericycle and, subsequently, the integrity of the trafficking machinery of these cells. We determined that GNOM is responsible for the recycling of AUX1 toward the plasma membrane at the xylem pole pericycle and impairment of this recycling results in premature accumulation of AUX1 in the vacuole. In this work, we describe a cell type-specific cellular mechanism and the role of a particular domain during lateral root development.
Single cell DNA methylation ageing in mouse blood

Ageing is the accumulation of changes and overall decline of the function of cells, organs and organisms over time. At the molecular and cellular level, the concept of biological age has been established and biomarkers of biological age have been identified, notably epigenetic DNA-methylation based clocks. With the emergence of single-cell DNA methylation profiling methods, the possibility to study biological age of individual cells has been proposed, and a first proof-of-concept study, based on limited single cell datasets mostly from early developmental origin, indicated the feasibility and relevance of this approach to better understand organismal changes and cellular ageing heterogeneity. Here we generated a large single-cell DNA methylation and matched transcriptome dataset from mouse peripheral blood samples, spanning a broad range of ages (10-101 weeks of age). We observed that the number of genes expressed increased at older ages, but gene specific changes were small. We next developed a robust single cell DNA methylation age predictor (scEpiAge), which can accurately predict age in a broad range of publicly available datasets, including very sparse data and it also predicts age in single cells. Interestingly, the DNA methylation age distribution is wider than technically expected in 19% of single cells, suggesting that epigenetic age heterogeneity is present in vivo and may relate to functional differences between cells. In addition, we observe differences in epigenetic ageing between the major blood cell types. Our work provides a foundation for better single-cell and sparse data epigenetic age predictors and highlights the significance of cellular heterogeneity during ageing. Highlights - Model to estimate DNA methylation age in single cells - Large multi-omics dataset of single cells from murine blood - Epigenetic age deviations from chronological age are greater than technical expected from technical variability - Number of genes expressed increases with chronological and epigenetic age