Miracle-dz/UniFAR-FTUs huggingface dataset:
Chromospheric evaporation in a well-observed compact flare

We have observed the flare of 1980 May 7 1456 UT with several Solar Meaximum Mission instruments, in coordination with the Sacramento Peak Observatory vacuum tower telescope. From the X-ray data we are able to determine the total emission measure of all material at T>2 x 10/sup 6/ K, commonly attributed to chromospheric evaporation. Volume estimates from X-ray and H.cap alpha. images lead to an estimate of the number of electrons in the soft X-ray plasma. Comparison of theoretical calculations of the H.cap alpha. signature of an evaporated state of the chromosphere to H.cap alpha. line profile observations shows that chromospheric evaporation indeed has taken place concurrently with the appearance of the X-ray plasma. We have determined the amount of material that has been evaporated from the chromosphere, relative to the preflare state. This leads us to the conclusion that more than enough material has been evaporated from the chromosphere to account for the material in the X-ray plasma. Taken together, the H.cap alpha. , soft, and hard X-ray images suggest that chromospheric evaporation is driven by two mechanisms. During the impulsive phase, there is evidence that chromospheric evaporation is due to flare-accelerated electrons. During the thermal phase, it appears tomore » be driven by thermal conduction from the hot coronal plasma created earlier in the flare. « less
Effect of arbitrary magnetic Reynolds number on MHD flows in convergent‐divergent channels

Purpose – The objective of the present study is to investigate the effect of arbitrary magnetic Reynolds number on steady flow of an incompressible conducting viscous liquid in convergent‐divergent channels under the influence of an externally applied homogeneous magnetic field.Design/methodology/approach – The solution of the non‐linear 2D Navier‐Stokes equations modeling the flow field is obtained using a perturbation technique coupled with a special type of Hermite‐Pade approximation method implemented numerically on MAPLE and a bifurcation study is performed.Findings – The results show that increasing values of magnetic Reynolds number causes a general decrease in the fluid velocity around the central region of the channel. The flow reversal control is also observed by increasing magnetic field intensity. The bifurcation study reveals the solution branches and turning points.Practical implications – The reported results are very useful in the field of engineering flow control and industrial metal cast.
Simulation analysis of the antenna structure for terahertz generation

The research on terahertz (THz) fields exists for decades of years, because of its promising applications in imaging, medical diagnosis, security inspection, information communication, etc. There are many ways to generate THz pulses, such as photoconductive effect, optical rectification, photomixing, and so on. For the detection of THz pulses, two methods, free space electro-optic sampling (FS-EOS) and photoconductive (PC) sampling, can be normally used. In our previous experiments, the photoconductive effect has been utilized to generate THz radiation from a piece of semiconductor with antenna structure. The amplitude of THz signals was found to be proportional to the magnitude of the electric field. To understand this more clearly and try to get better THz signals, simulation analysis of the electric field in between the electrodes of the photoconductive antenna has been done, and a optimized antenna structure which will be more efficient than the parallel dipolar electrodes has been designed based on the simulation analysis.
Kernel and Nearest-Neighbor Estimation of a Conditional Quantile

Let (X 1 , Z 1 ), (X 2 ,Z 2 ), . , (X n , Z n ) be iid as (X, Z), and for 0<p<1, let ξ p (x) denote the conditional p-quantile of Z given X=x, i.e., P(Z≤ξ p (x)|X=x)=p. Kernel and near-est-neighbor estimators of ξ p (x) are proposed. In order to study the asymptotics of these estimates, Bahadur-type representations of the sample conditional quantiles are obtained. These representations are used to examine the important issue of choosing the smoothing parameter by a local approach (for a fixed x) based on weak convergence of these estimators. The results lead to asymptotic linear models which motivate certain estimators
Absolute intensities of acoustic shadow zone arrivals

Qualitative observations from bottom‐mounted US Navy SOSUS receiving stations in the North Pacific reveal anomalously deep acoustic arrivals at travel times directly corresponding with timefronts expected to have turned much higher in the water column. The vertical structure of these shadow zone arrivals was studied during SPICEX, a long‐range propagation experiment conducted from June to November 2004 in the North Pacific, utilizing moored sources 500 and 1000 km distant from two vertical line array receivers, which together virtually spanned the full ocean depth. Comparison of the measured absolute intensities of shadow zone arrivals with Monte Carlo parabolic equation simulations suggest that the amount of internal wave scattering associated with the standard Garrett‐Munk (GM) internal wave spectrum is not adequate to account for the extent of scattering into the acoustic shadow evident in the experimental data, suggesting either that the GM spectrum is not an appropriate representation of the internal.
THE TWO POINT CORRELATION FUNCTION FOR GROUPS OF GALAXIES IN THE CENTER FOR ASTROPHYSICS REDSHIFT SURVEY

The large-scale distribution of groups of galaxies selected from complete slices of the CfA redshift survey extension is examined. The survey is used to reexamine the contribution of group members to the galaxy correlation function. The relationship between the correlation function for groups and those calculated for rich clusters is discussed, and the results for groups are examined as an extension of the relation between correlation function amplitude and richness. The group correlation function indicates that groups and individual galaxies are equivalent tracers of the large-scale matter distribution. The distribution of group centers is equivalent to random sampling of the galaxy distribution. The amplitude of the correlation function for groups is consistent with an extrapolation of the amplitude-richness relation for clusters. The amplitude scaled by the mean intersystem separation is also consistent with results for richer clusters. 35 refs.
A SURVEY OF 0II EMISSION IN ELLIPTICAL GALAXIES.

A survey of elliptical galaxy spectra using image-tube spectrograms has been carried out with the result that 40 percent of the galaxies have been found to contain ionized gas. Galaxies with intense nuclear emission also tend to have extended emission that appears to be confined to a plane. Since there is a detectable velocity gradient for the gas in those planes, the gas appears to be in a rotating disk.
Comment on “Ghost cytometry”

Ota et al. (Reports, 15 June 2018, p. 1246) report using pseudo-random optical masks and a spatial-temporal transformation to perform blur-free, high–frame rate imaging of cells in flow with a high signal-to-noise ratio. They also claim sorting at rates of 3000 cells per second, based on imaging data. The experiments conducted and results reported in their study are insufficient to support these conclusions.
Entropy-based Mesh Simplification

AbstractComplex mesh models usually affect the performance of algorithms for CAD applications. Therefore, it is often desirable to use simplified models and at the same time preserves the general features of the shape. In this paper, we present an entropy based surface mesh simplification algorithm which can rapidly and efficiently produce high quality approximations of triangle mesh models. The algorithm uses iterative contraction of edges to simplify models. It first exploits the geometric feature of model surface by estimating vertex curvature entropy and then iteratively contracts edges with relatively lower simplification cost. The simplification cost is measured by a combination of vertex curvature and curvature entropy of the two vertices compositing the edge. The goal is to simplify regions that are relatively flat while preserving salient features of the shape. Experiments show promising results of the algorithm.
The ionization structure of planetary nebulae. III - NGC 7009

Spectrophotometric observations of emission line intensities were made in 8 positions in the planetary nebula NGC 7009. For the 6 brightest positions, the coverage is from 1400 A to 10,000 A. Standard equations used to correct for the existence of elements in other than the optical observable ionization stages give results over a wide range of ionization that are consistent and agree with abundances calculated using ultraviolet lines. This result is particularly gratifying for N because previously the standard formula gave inconsistent abundances in NGC 7009. The major outstanding problem is that the lambda 4267 CII line implies a C(2+) abundance as much as 12 times greater than that determined from the UV lines. This discrepancy is greatest nearest the central star, as is the case in the planetary nebula NGC 6720. The logarithmic abundances (relative to H=12.00) are: He=11.07, 0=8.68, N=8.10, Ne=8.16, C=8.18, Ar=6.36, and S=7.12. The average of the Ne, Ar, and S abundances agrees to within 5% of that for NGC 6720, but the O, N, nd C abundances average 1.9 times lower in NGC 7009, suggesting that here may have been mixing of processed material in the planetary precursor in NGC 6720.
Dual Flows with Supersonic Velocities in the Sunspot Transition Region

Observations of sunspot transition region lines that deviate significantly from a Gaussian shape are presented. Attention is given to "dual flows," a line profile phenomenon in which two distinct velocities are observed within the same spatial resolution element. In 5 out of 12 sunspots we observe dual flows. Several emission line profiles are well represented by two Gaussian line components, one with a subsonic and one with a supersonic line-of-sight velocity.
Stability of thermocapillary‐driven flow in rectangular cavities

The flow in an infinitely extended cavity with rectangular cross section is considered. The upper boundary is a free surface where thermocapillary forces are driving a circulation within the cavity (Marangoni effect). If the driving force (temperature difference) exceeds a critical threshold, the two dimensional flow becomes unstable towards an infinitesimal three‐dimensional perturbation. The critical mode depends on the aspect ratio and may be steady or oscillatory. Results are presented for vanishing Prandtl number and varying aspect ratios of the cavity. These are compared to the classical lid‐driven cavity problem and the mechanism leading to instability is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient UAV Path Planning with Multiconstraints in a 3D Large Battlefield Environment

This study introduces an improved algorithm for the real-time path planning of Unmanned Air Vehicles (UAVs) in a 3D large-scale battlefield environment to solve the problem that UAVs require high survival rates and low fuel consumption. The algorithm is able to find the optimal path between two waypoints in the target space and comprehensively takes factors such as altitude, detection probability, and path length into account. It considers the maneuverability constraints of the UAV, including the safety altitude, climb rate, and turning radius, to obtain the final flyable path. Finally, the authors test the algorithm in an approximately 2,500,000 square meter area containing radars, no-fly zones, and extreme weather conditions to measure its feasibility, stability, and efficiency.
Three‐dimensional flows over backward facing s.tif

Three‐dimensional flows over backward facing s.tif are analysed by means of a finite element procedure, which shares many features with the SIMPLER method. In fact, given an initial or guessed velocity field, the pseudovelocities, i.e. the velocities that would prevail in the absence of the pressure field, are found first. Then, by enforcing continuity on the pseudovelocity field, the tentative pressure is estimated, and the momentum equations are solved in sequence for velocity components. Afterwards, continuity is enforced again to find corrections that are used to modify the velocity field and the estimated pressure field. Finally, whenever necessary, the energy equation is solved before moving to the next step.
Isothermal, Compton-heated Coronae above Accretion Disks

The structure of Compton-heated coronae above accretion disks is studied here by using analytic and numerical approaches are used here to determine the direct and scattered radiation reaching the base of the corona for a range of central source luminosities. It is found that the outer region of the corona is unaffected by multiple scattering in the interior, provided that the luminosity of the central source is sufficient below the Eddington limit. How attenuation and scattering by the corona affects the strength of chromospheric emission lines is determined, as is the condition for which the irradiation due to the central source exceeds the locally generated flux from the disk. Finally, it is shown that the stability analysis for irradiated accretion disks of Tuchman et al. is not substantially altered by the corona. 29 refs.
HDAC3-Mediated Repression of the Nr4a Family Contributes to Age-Related Impairments in Long-Term Memory

Aging is accompanied by cognitive deficits, including impairments in long-term memory formation. Understanding the molecular mechanisms that support preserved cognitive function in aged animals is a critical step toward identifying novel therapeutic targets that could improve memory in aging individuals. One potential mechanism is the Nr4a family of genes, a group of CREB-dependent nuclear orphan receptors that have previously been shown to be important for hippocampal memory formation. Here, using a cross-species approach, we tested the role of Nr4a1 and Nr4a2 in age-related memory impairments. Using a rat model designed to identify individual differences in age-related memory impairments, we first identified Nr4a2 as a key gene that fails to be induced by learning in cognitively impaired male aged rats. Next, using a mouse model that allows for genetic manipulations, we determined that histone deacetylase 3 (HDAC3) negatively regulates Nr4a2 in the aged male and female hippocampus. Finally, we show that overexpression of Nr4a1, Nr4a2, or both transcripts in the male mouse dorsal hippocampus can ameliorate age-related impairments in object location memory. Together, our results suggest that Nr4a2 may be a key mechanism that promotes preserved cognitive function in old age, with HDAC3-mediated repression of Nr4a2 contributing to age-related cognitive decline. More broadly, these results indicate that therapeutic strategies to promote Nr4a gene expression or function may be an effective strategy to improve cognitive function in old age. SIGNIFICANCE STATEMENT Aging is accompanied by memory impairments, although there is a great deal of variability in the severity of these impairments. Identifying molecular mechanisms that promote preserved memory or participate in cognitive reserve in old age is important to develop strategies that promote healthy cognitive aging. Here, we show that learning-induced expression of the CREB-regulated nuclear receptor gene Nr4a2 is selectively impaired in aged rats with memory impairments. Further, we show that Nr4a2 is regulated by histone deacetylase HDAC3 in the aged mouse hippocampus. Finally, we demonstrate that hippocampal overexpression of either Nr4a2 or its family member, Nr4a1, can ameliorate age-related memory impairments. This suggests that promoting Nr4a expression may be a novel strategy to improve memory in aging individuals.
Giant magnetic refrigeration capacity near room temperature in Ni40Co10Mn40Sn10 multifunctional alloy

We report a giant effective magnetic refrigeration capacity in a Ni40Co10Mn40Sn10 multifunctional alloy. With a large magnetization difference between austenite and martensite, this alloy shows a strong magnetic field dependence of transformation temperatures. Complete magnetic-field-induced structural transformation and a considerable magnetic entropy change are observed in a broad operating temperature window of 33 K near room temperature. Consequently, an effective magnetic refrigeration capacity of 251 J/kg for 5 T is achieved, which is the largest value for Ni-Mn-based Heusler alloys and comparable to that of the high-performance Gd-Si-Ge and La-Fe-Si magnetocaloric materials. Incorporating the advantages of low cost and non-toxicity, this alloy shows very promising prospects for room-temperature magnetic refrigeration.
Post-frontal shower cells in the COSMO-DE model. A comparison with radar measurements

The NWP model COSMO-DE is run operationally at the German Meteorological Service (Deutscher Wetterdienst, DWD) with a horizontal grid size of 2.8 km. Due to the high resolution the COSMO-DE model has no parameterization of the deep moist convection, so that the model must resolve the macrostructure of convective phenomena explicitly. This study analyses post-frontal rain areas of COSMO-DE model simulations with respect to their spatial and temporal structure. The same analysis is applied to the RZ product, a radar composite of the German Meteorological Service, for comparison. Ensemble properties like rain area size distribution and mean life cycle of shower cells have been analysed. The examined properties are based on different former investigations, that use radar measurements to characterize the structure of post-frontal rain areas. By comparing the statistical properties of rain cells as obtained from radar observations and model simulations one gets a first impression of model performance concerning precipitation forecast under convective situations. Basically the ensemble properties arising from the radar measurements also apply to the COSMO-DE simulations. Slight differences are related to the intensity of the rain areas or are connected to the different spatial resolution of the two datasets. Our analysis differs from usual model verifications, where ground based rain measurements are compared with precipitation forecasts over larger areas and time intervals.
Sta¨kel equivalent integrable Hamiltonian systems

The Stackel transform is a mapping of the commuting constants of the motion (corresponding to a separable coordinate system) for one completely integrable classical or quantum Hamiltonian system to the constants of the motion for another such system. Here the transform is defined and given an intrinsic characterization, and a large family of nontrivial examples is worked out of systems which are “Stackel equivalent”. Among the simplest examples are geodesic flow on an n-dimensional ellipsoid with distinct axes, which is equivalent to the motion of a mass point on the unit sphere in $R^{n + 1} $ under the influence of a quadratic potential with distinct eigenvalues, and the Kepler (Coulomb) problem in three dimensions which is equivalent to the pseudo-Coulomb problem.
FIBER CONES WITH ALMOST MAXIMAL DEPTH

ABSTRACT Let A be a noetherian local ring with dimension d and I be an ideal of A . Let E=( E n )n≥ 0 be a good I-filtration of submodules of an A-module E . Let H be an ideal of A containing I and F H E) = ⨁n ≥ 0 E n / HE n . Assume that E is a Cohen–Macaulay module with λ(E/IE) finite and Ann(E) = 0, and let J be a minimal reduction of I. In this paper we give conditions on λ(E n ∩ JE/JE n−1) and λ(HE n ∩ JE/JHE n−1) so, that F H (E), has depth of at least d − 1.
Near-infrared imaging of RAFGL7009S

RAFGL7009S is a deeply embedded massive young stellar objet (YSO) showing strong ice and saturated silicate absorption features in the mid infrared. It is associated with the ultracompact H n region G25.65+1.05, which maybe excited by a B 1V star. We have obtained JHK images of a 1' field centred on this YSO. In K we detect a non-resolved object coinciding with the radio continuum emission peak. Considering the high extinction towards this source (A v > 100 mag), the observed K emission is more than 7 mag in excess of that expected for a B1V star. We suggest that this emission is mainly due to scattering of the central zone emission, as recently found for a sample of embedded massive YSOs associated with 3.1 μm H 2 O ice absorption (Ishii et al. 2002). We estimate the YSO's age to be 2×10 4 years. The outflow, the methanol maser emission and the strong ice absorption features suggest the presence of a dense medium very close to the star, possibly a disk.
Psychological Well-Being of Older Adults With Cognitive Deterioration During Quarantine: Preliminary Results From the GeroCovid Initiative

Objectives: The spread of COVID-19 has undeniably unsettled the social, psychological and emotional life of the entire world population. Particular attention should be paid to older adults with dementia, given their vulnerability to emotional stressors. The aim of this retrospective study is to evaluate the impact of the first wave quarantine related to Covid-19 on psychological and affective well-being of older adults with mild/major neurocognitive disorders and of their caregivers. Methods: Data on participants' assessment before the quarantine (PREQ) were retrospectively collected. Patients with Mild Cognitive Impairment (MCI) or dementia were recruited from different Centers for Cognitive Decline and Dementia in Italy. During the quarantine, psychological and affective well-being were evaluated by phone through the administrations of scales measuring anxiety and depression (DASS), perceived stress (PSS), coping strategies (COPE) and the caregivers' burden (CBI). The scales' results were compared across participants' PREQ cognitive level (Mini Mental State Examination, MMSE ≥25, 23–24, and ≤ 22) with multiple linear regression models. Results: The sample included 168 patients (64% women) with a mean age of 79 ± 7 years. After adjusting for potential confounders, more severe cognitive impairment was independently associated with higher DASS and PSS score, and poorer coping strategies (p < 0.05). Cognitive functioning was also inversely associated with CBI. Conclusions: The impact of the quarantine on the psycho-affective well-being of individuals with MCI and dementia and on caregivers' burden varies according to the PREQ cognitive functioning with more severely impaired patients having worse outcomes.
Estimation of a Convex Density Contour in Two Dimensions

Abstract If a density in two dimensions has a convex contour containing probability α, the contour may be estimated from a sample by finding the convex polygon of smallest area containing a proportion α of the sample points. An algorithm for finding a particular contour is given that takes O(n 2) space and O(n 3) time for n sample points.