Miracle-dz/UniFAR-FTUs huggingface dataset:
Spaces of bochner integrable functions and spaces of representable operators as U-ideals

IN this paper we study the geometry of the space of Bochner integrable functions as a subspace of the space of vector valued countably additive measures of finite variation and that of the space of representable operators as a subspace of the space of bounded linear operators. Let £ be a Banach space and (fi, si, fi) a finite measure space; let cabv(fi, E) denote the space of countably additive £-valued measures of finite variation that are absolutely continuous with respect to fi. Drewnowski and Emmanuele [6] have proved recently that if £ has a copy of c0 then L ^, E), the space of Bochner integrable functions, is not complemented in cabv(fi, £). However, if one is interested in weaker geometric conditions like being locally 1-complemented (recall from [12], that a closed subspace Y of a Banach space X is said to be locally 1-complemented if Y is the kernel of a norm one projection in X*\ such a subspace was called an "ideal" in [9]) then L(ji, E) is always locally 1-complemented in cabv(/i, £). Similarly 9? (L'(/A), £) the space of representable operators from L{fi) to £ is a locally 1-complemented subspace of if(L(/u.)£), the space of bounded linear operators (see [14]). Here again, if E has a copy of c0 then 9L{L}(JJL), E) is not complemented in 2(V(jt), E) (see [8]). These results suggest that better and more reasonable geometric properties to study in this context are the notions of "L-ideal and <ft-summand recently introduced by Godefroy, Kalton and Saphar in [9]. Let us recall from [9], that a subspace Y of X is said to be a ^-summand if Y is the range of a (unique) projection P in X satisfying ||7 2P|| = 1 and Y is said to be a "ft-ideal if Y is a %-summand in X*. Since the condition ||7 2P\\ = 1 implies ||P|| = 1 (and | | 7 P|| = 1) any <ft-ideal is clearly an ideal. Following the approach of Godefroy et al, who use the notion of unconditional compact approximation property (UKAP) to study similar questions in the context of the space of compact operators,
Blazhko Effect in the first overtone RR Lyrae stars of the OGLE Galactic bulge collection

We present the analysis of the Blazhko effect - quasi-periodic modulation of pulsation amplitude and/or phase - in the Galactic bulge first overtone RR Lyrae stars (RRc). We used the data gathered during the fourth phase of the Optical Gravitational Lensing Experiment (OGLE). Out of 10 826 analyzed RRc stars, Blazhko effect was detected in 607 stars which constitute 5.6 percent of the sample. It is the largest and most homogeneous sample of modulated RRc stars analyzed so far. Modulation periods cover a wide range, from slightly above 2 d to nearly 3000 d. Multiperiodic modulation was detected in 47 stars. The appearance of modulation in the frequency domain was studied in detail. Modulation manifests either as close doublets or as equidistant triplets and multiplets centered on radial mode frequency and its harmonics. In a significant fraction (29 percent) of stars, we have detected the modulation frequency itself, which corresponds to the modulation of the mean stellar brightness. Our search for period doubling effect, that was discovered recently in modulated fundamental mode RR Lyrae stars, and triggered development of new model behind the Blazhko modulation, yielded negative result. In 104 stars we detected additional signals that could correspond to both radial and non-radial modes. Statistical properties of modulated stars were analyzed in detail and confronted with properties of non-modulated stars and of modulated fundamental mode RR Lyrae stars. Our analysis provides constraints for the models to explain the Blazhko phenomenon, which still remains a puzzle more than hundred years after its discovery.
Large-signal output characteristic investigation of the MOSFETs in the breakdown region based on X-parameters

In this paper, large-signal output characteristics of the metal–oxide–semiconductor field-effect transistors in the breakdown region are investigated using X-parameter measurements for the first time. Magnitude of coefficients can be larger than the result of coefficients at high input power as drain voltage increases to the breakdown region. The output impedance under large-signal drive incorporating with the and coefficients is derived and then employed to investigate output matching in the breakdown region and at high input power, which is significant for power amplifier designs. Compared with the conventional hot-Z2121 without coefficients considered, can be more accurate for the output impedance characterization. The presented analysis based on the X-parameters can be beneficial to output matching at high input power for power amplifier designs in the breakdown region.
Discovery of GRB 020405 and Its Late Red Bump

We present the discovery of GRB 020405 made with the Interplanetary Network (IPN). With a duration of 60 s, the burst appears to be a typical long-duration event. We observed the 75 arcmin2 IPN error region with the Mount Stromlo Observatory's 50 inch robotic telescope and discovered a transient source that subsequently decayed and was also associated with a variable radio source. We identify this source as the afterglow of GRB 020405. Subsequent observations by other groups found varying polarized flux and established a redshift of 0.690 to the host galaxy. Motivated by the low redshift, we triggered observations with WFPC2 on board the Hubble Space Telescope (HST). Modeling the early ground-based data with a jet model, we find a clear red excess over the decaying optical light curves that is present between day 10 and day 141 (the last HST epoch). This bump has the spectral and temporal features expected of an underlying supernova (SN). In particular, the red color of the putative SN is similar to that of the SN associated with GRB 011121 at late time. Restricting the sample of GRBs to those with z < 0.7, a total of five bursts, red bumps at late times are found in GRB 970228, GRB 011121, and GRB 020405. It is possible that the simplest idea, namely, that all long-duration γ-ray bursts have underlying SNe with a modest dispersion in their properties (especially peak luminosity), is sufficient to explain the nondetections.
Constraining the Metallicity of the Low-Density Lyα Forest Using O VI Absorption

We present a systematic search for O VI (1032, 1037 Å) absorption in a Keck High-Resolution Echelle Spectrometer spectrum of the z = 3.62 quasar Q1422+231, with the goal of constraining the metallicity and ionization state of the low-density intergalactic medium (IGM). Comparison of C IV absorption measurements to models of the Lyα forest based on cosmological simulations shows that absorbers with NH I ≳ 1014.5 cm-2 have a mean carbon abundance [C/H] ≈ -2.5, assuming a metagalactic photoionizing background with the spectral shape predicted by Haardt and Madau in 1996. In these models, lower column density absorption arises in lower density gas where most C IV is photoionized to C V. Therefore, O VI should be the most sensitive tracer of metallicity in Lyα absorbers with NH I ≲ 1014.5 cm-2. O VI lines lie at wavelengths heavily contaminated by Lyman series absorption, so we interpret the search results by comparing them to carefully constructed, mock Q1422 spectra drawn from a hydrodynamic simulation of a Λ-dominated cold dark matter model. A search for deep, narrow absorption features yields only a few candidate O VI lines in the spectrum of Q1422. H I absorption blankets the position of the doublet companion line in each case, and the total number of narrow lines is statistically consistent with that in zero-metallicity artificial spectra. Artificial spectra generated with the Haardt and Madau background and [O/H] ≳ -2.5 predict too many narrow lines and are statistically inconsistent with the data. We also search for O VI associated with C IV systems, using the optical depth ratio technique of Songaila. With this method we do find significant O VI absorption; matching the data requires [O/C] ≈ 0.5 and corresponding [O/H] ≈ -2.0. Taken together, the narrow-line and optical depth ratio results imply that (1) the metallicity in the low-density regions of the IGM is at least a factor of 3 below that in the overdense regions where C IV absorption is detectable, and (2) oxygen is overabundant in the C IV regions, consistent with the predictions of Type II supernova-enrichment models and the observed abundance pattern in old halo stars. The photoionizing background spectrum would be truncated above 4 Ryd in regions that have not undergone helium reionization (He II → He III), and in this case matching the Q1422 data requires lower [C/H] but higher [O/H]. Taking [O/C] ≈ 1 as the maximum plausible overabundance of oxygen, we conclude that helium must have been reionized through at least 50% of the volume from z ~ 3-3.6.
A One-dimensional Land Surface Model Adaptable to Intensely Cold Regions and its Applications in Eastern Siberia

A one-dimensional land surface model has been developed to estimate water and energy fluxes between the atmosphere and ground surfaces. The model includes three submodels; vegetation, snow cover, and soil. In order to adapt the model to intensely cold regions, the snow cover submodel can consider depth hoar by means of effective temperature gradient. This submodel can calculate profiles of snow temperature, density, and liquid water content using meteorological data inputs; the model structure is simple having snow layers with the same thickness. The ratio of fallen snow amount to rain amount is given as a function of wet-bulb temperature. The model has been applied to a GAME-Siberia site in the Central Yakutia, Russia. Since we do not have complete data sets in midwinter, the model has been validated through whole winter simulations at several routine stations first. Snow depth and snow-cover period are simulated reasonably. Next, fluxes have been estimated using 1998 data at the GAME plain taiga site, compared with the observed fluxes. Diurnal and seasonal changes of fluxes are simulated reasonably. The calculated snow cover disappearance date is earlier than the observed day.
The Origin of Faint Tidal Features around Galaxies in the RESOLVE Survey

We study tidal features around galaxies in the REsolved Spectroscopy Of a Local VolumE (RESOLVE) survey. Our sample consists of 1048 RESOLVE galaxies that overlap with the DECam Legacy Survey, which reaches an r-band 3σ depth of ∼27.9 mag arcsec−2 for a 100 arcsec2 feature. Images were masked, smoothed, and inspected for tidal features such as streams, shells, or tails/arms. We find tidal features in 17±2% of our galaxies, setting a lower limit on the true frequency. The frequency of tidal features in the gas-poor (gas-to-stellar mass ratio <0.1) subsample is lower than in the gas-rich subsample (13±3% versus 19±2%). Within the gas-poor subsample, galaxies with tidal features have higher stellar and halo masses, ∼3× closer distances to nearest neighbors (in the same group), and possibly fewer group members at fixed halo mass than galaxies without tidal features, but similar specific star formation rates. These results suggest tidal features in gas-poor galaxies are typically streams/shells from dry mergers or satellite disruption. In contrast, the presence of tidal features around gas-rich galaxies does not correlate with stellar or halo mass, suggesting these tidal features are often tails/arms from resonant interactions. Similar to tidal features in gas-poor galaxies, tidal features in gas-rich galaxies imply 1.7× closer nearest neighbors in the same group; however, they are associated with diskier morphologies, higher star formation rates, and higher gas content. In addition to interactions with known neighbors, we suggest that tidal features in gas-rich galaxies may arise from accretion of cosmic gas and/or gas-rich satellites below the survey limit.
No purification in all discrete theories and the power of the complete extension

Quantum theory has an outstanding property, namely each state has its well defined purification - a state extremal in the set of states in larger Hilbert space. It is known that the classical theory and the theory of non-signaling boxes does not have purification for all of their states. These theories are examples of the so called generalized probabilistic theories (GPTs). However in any non-signaling GPT each state has a number of extensions to a larger system. We single out the most relevant among them, called a complete extension, unique up to local reversible operations on the extending system. We prove that this special, finite dimensional extension bares an analogy to quantum purification in that (i) it allows for an access to all ensembles of the extended system (ii) from complete extension one can generate any other extension. It then follows, that an access to the complete extension represents the total power of the most general non-signaling adversary. A complete extension of a maximally mixed box in two-party binary input binary output scenario is up to relabeling the famous Popescu-Rohrlich box. The latter thus emerges naturally without reference to the Bell's non-locality. However the complete extension is not a purification (a vertex) in the generic case. Moreover, we show that all convex discrete theories does not provide purification for almost all of it states. In particular the theory of contextuality does not possess purification. The complete extensions are by nature high-dimensional systems. We were able however to provide explicit structure of complete extension for the noisy Popescu-Rohrlich-boxes and the 3-cycle contextual box.
The structural and luminescence properties of porous silicon

A large amount of work world-wide has been directed towards obtaining an understanding of the fundamental characteristics of porous Si. Much progress has been made following the demonstration in 1990 that highly porous material could emit very efficient visible photoluminescence at room temperature. Since that time, all features of the structural, optical and electronic properties of the material have been subjected to in-depth scrutiny. It is the purpose of the present review to survey the work which has been carried out and to detail the level of understanding which has been attained. The key importance of crystalline Si nanostructures in determining the behaviour of porous Si is highlighted. The fabrication of solid-state electroluminescent devices is a prominent goal of many studies and the impressive progress in this area is described.
Time-dependent coronal shock acceleration of energetic solar flare particles

A global time-dependent model is presented for the coronal and interplanetary shock acceleration and propagation of energetic solar flare particles. The calculations are carried out to help prove that coronal shock acceleration of solar flare particles is responsible for energetic solar flare event data gathered in interplanetary space. The model is based on the theory of diffusive shock acceleration, and requires particle speeds to be much greater than bulk velocities. Also, sufficient scattering must occur upstream and downstream of the shock for the particle scattering mean free path to be smaller than the characteristic scale lengths, which causes the same particles to encounter the shock repeatedly. A spherically symmetric shock wave is assumed, which leads to the same emission configuration for impulsively and monoenergetically emitted particles. Consideration is given to acceleration by compression at the shock front, adiabatic deceleration in the divergent downstream flow, the temporal evolution of the shock and the three-dimensional geometry of the corona. The model is used to generate normalized proton omnidirectional distributions at 1 AU and at the shock front. The spectral exhibit trends similar to those in observational data, especially proton acceleration times and the proton distribution profiles at 1 AU. 92 references
Genome-wide analysis of maize OSCA family members and their involvement in drought stress

Background Worldwide cultivation of maize is often impacted negatively by drought stress. Hyperosmolality-gated calcium-permeable channels (OSCA) have been characterized as osmosensors in Arabidopsis. However, the involvement of members of the maize OSCA (ZmOSCA) gene family in response to drought stress is unknown. It is furthermore unclear which ZmOSCA gene plays a major role in genetic improvement of drought tolerance in Maize. Methods We predicted the protein domain structure and transmembrane regions by using the NCBI Conserved Domain Database database and TMHMM server separately. The phylogeny tree was built by Mega7. We used the mixed linear model in TASSEL to perform the family-based association analysis. Results In this report, 12 ZmOSCA genes were uncovered in the maize genome by a genome-wide survey and analyzed systematically to reveal their synteny and phylogenetic relationship with the genomes of rice, maize, and sorghum. These analyses indicated a relatively conserved evolutionary history of the ZmOSCA gene family. Protein domain and transmembrane analysis indicated that most of the 12 ZmOSCAs shared similar structures with their homologs. The result of differential expression analysis under drought at various stages, as well as the expression profiles in 15 tissues, revealed a functional divergence of ZmOSCA genes. Notably, the expression level of ZmOSCA4.1 being up-regulated in both seedlings and adult leaves. Notably, the association analysis between genetic variations in these genes and drought tolerance was detected. Significant associations between genetic variation in ZmOSCA4.1 and drought tolerance were found at the seedling stage. Our report provides a detailed analysis of the ZmOSCAs in the maize genome. These findings will contribute to future studies on the functional characterization of ZmOSCA proteins in response to water deficit stress, as well as understanding the mechanism of genetic variation in drought tolerance in maize.
Rapid morphological change of nonnative frugivores on the Hawaiian island of O'ahu *

Novel ecosystems have become widespread created, in part, by the global spread of species. The nonnative species in these environments can be under intense evolutionary pressures that cause rapid morphological change, which can then influence species interactions. In Hawaii, much of the native frugivore community is extinct, replaced by nonnative bird species. Here, we determined if the passerine species of the nonnative frugivore community on O'ahu have morphologically diverged from their native ranges. We compared a variety of traits, all important for frugivory, between museum specimens from the species’ native ranges to wild individuals from O'ahu. All four species tested exhibited significant divergence ranging in magnitude from 2.3% to 13.0% difference in at least two traits. Using a method developed from quantitative genetics, we found evidence that a mixture of nonadaptive and adaptive processes worked in concert to create the observed patterns of divergence. Our results suggest that rapid morphological change is occurring and, based on the traits measured, that these changes may influence seed dispersal effectiveness. As these species are largely responsible for seed dispersal on the island, the rapid morphological change of these species can influence the stability and maintenance of plant communities on O'ahu.
Primordial non-Gaussianity and the CMB bispectrum

We present a new formalism, together with efficient numerical methods, to directly calculate the cosmic microwave background (CMB) bispectrum today from a given primordial bispectrum using the full linear radiation transfer functions. Unlike previous analyses which have assumed simple separable Ans\"atze for the bispectrum, this work applies to a primordial bispectrum of almost arbitrary functional form, for which there may have been both horizon-crossing and superhorizon contributions. We employ adaptive methods on a hierarchical triangular grid and we establish their accuracy by direct comparison with an exact analytic solution, valid on large angular scales. We demonstrate that we can calculate the full CMB bispectrum to greater than 1% precision out to multipoles $ll1800$ on reasonable computational time scales. We plot the bispectrum for both the superhorizon (``local'') and horizon-crossing (``equilateral'') asymptotic limits, illustrating its oscillatory nature which is analogous to the CMB power spectrum.
After the Fall: The Dust and Gas in E+A Post-starburst Galaxies

The traditional picture of post-starburst galaxies as dust- and gas-poor merger remnants, rapidly transitioning to quiescence, has been recently challenged. Unexpected detections of a significant interstellar medium (ISM) in many post-starburst galaxies raise important questions. Are they truly quiescent, and if so, what mechanisms inhibit further star formation? What processes dominate their ISM energetics? We present an infrared spectroscopic and photometric survey of 33 E+A post-starbursts selected by the Sloan Digital Sky Survey, aimed at resolving these questions. We find compact, warm dust reservoirs with high PAH abundances and total gas and dust masses significantly higher than expected from stellar recycling alone. Both polycyclic aromatic hydrocarbon (PAH)/total infrared (TIR) and dust-to-burst stellar mass ratios are seen to decrease with post-burst age, indicative of the accumulating effects of dust destruction and an incipient transition to hot, early-type ISM properties. Their infrared spectral properties are unique, with dominant PAH emission, very weak nebular lines, unusually strong H2 rotational emission, and deep [C ii] deficits. There is substantial scatter among star formation rate (SFR) indicators, and both PAH and TIR luminosities provide overestimates. Even as potential upper limits, all tracers show that the SFR has typically experienced a decline of more than two orders of magnitude since the starburst and that the SFR is considerably lower than expected given both their stellar masses and molecular gas densities. These results paint a coherent picture of systems in which star formation was, indeed, rapidly truncated, but in which the ISM was not completely expelled, and is instead supported against collapse by latent or continued injection of turbulent or mechanical heating. The resulting aging burst populations provide a “high-soft” radiation field that seemingly dominates the E+A galaxies’ unusual ISM energetics.
On the motion of suspension thermals and particle swarms

When a load dense particulate material is dumped from a barge, it descends in the water body as an irregularly shaped particle cloud. Provided that the particles are suflicienly small to be kept in suspension initially, the motion of the cloud is similar to that of a thermal of warm air rising in the atmosphere. Both types of buoyant clouds increase in size and slow down as they progress. For suspension clouds this thermal stage ends when their velocity has decreased to a value which is close to the individual settling velocity of the particles in a calm tluid. and the particles start falling out through the lower fringes of the cloud. After this transition is completed, a smooth, bowl-shaped particle swarm develops. An important difference between these two tlow regimes is that in the thermal stage the tluid inside the cloud moves in unison with the particles, whilst the interstitial fluid in the swarm stage remains nearly motionless as the particles rain through it. In this paper we propose a relation for the growth rate and velocity of thermals which is also applicable in the swarm stage. The resulting description thus covers the entire range of flows which are of interest for barge dumping. Experimental results are presented w hich allow a determination of the relevant flow constants in the swarm stage.