Miracle-dz/UniFAR-FTUs huggingface dataset:
Find your microenvironments faster with Neural Spatial LDA

Spatial organization of different cell types in tissues have been shown to be important factors in many important biological processes such as aging, infection and cancer [3]. In particular, organization of the cells in a tumor microenvironment (TME) has been shown to play a crucial role in treatment response, disease pathology and patient outcome [14]. Spatial LDA [5] is a general purpose probabilistic model that has been used to discover novel microenvironments in settings such as Triple Negative Breast Cancer (TNBC) and Tuberculosis infections. However, the implementation of Spatial LDA proposed in [5] uses variational inference for learning model parameters and unfortunately does not scale well with dataset size and does not lend itself to speed-up via GPUs / TPUs. As researchers begin to collect larger in-situ multiplexed imaging datasets, there is a growing need for more scalable approaches for analysis of microenvironments. Here we propose a VAE-style network which we call Neural Spatial LDA extending the auto-encoding Variational Bayes formulation of classical LDA from [18]. We show Neural Spatial LDA achives significant speed-up over Spatial LDA while at the same time recovering similar topic distributions thus enabling its use in large data domains.
Transient, turbulent, smooth pipe friction

Two of the most promising analytical models of unsteady friction in turbulent pipe flows are based on sharply contrasting hypotheses. One uses the history of the flow; the other uses instantaneous conditions. The purposes of this paper are to present an analysis using the former approach and to indicate how to determine which of the two methods is appropriate. A weighting function model of transient friction is developed for flows in smooth pipes by assuming the turbulent viscosity to vary linearly within a thick shear layer surrounding a core of uniform velocity and is thus applicable to flows at high Reynolds number. In the case of low Reynolds number turbulent flows and short time intervals, the predicted skin friction is identical to an earlier model developed by Vardy et al (1993). In the case of laminar flows, it gives results equivalent to those of Zielke (1966, 1968). The predictions are compared with analytical results for the special case of flows with uniform acceleration. It is this case that .
A dynamic nonlinear subgrid-scale stress model

In this paper, a dynamic subgrid scale (SGS) stress model based on Speziale’s quadratic nonlinear constitutive relation [C. G. Speziale, J. Fluid Mech. 178, 459 (1987); T. B. Gatski and C. G. Speziale, J. Fluid Mech. 254, 59 (1993)] is proposed, which includes the conventional dynamic SGS model as its first-order approximation. The closure method utilizes both the symmetric and antisymmetric parts of the resolved velocity gradient, and allows for a nonlinear anisotropic representation of the SGS stress tensor. Unlike the conventional Smagorinsky type modeling approaches, the proposed model does not require an alignment between the SGS stress tensor and the resolved strain rate tensor. It exhibits significant flexibility in self-calibration of the model coefficients, and local stability without the need for plane averaging to avoid excessive backscatter of SGS turbulence kinetic energy and potential modeling singularity problems. It also allows for variable tensorial geometric relations between the SGS str.
Impact of Sea Surface Temperature Anomalies on the Atlantic Tropical Storm Activity and West African Rainfall

Abstract The association between rainfall over the Sahel and Sudan region and tropical storm activity in the Atlantic is examined using the NCEP–NCAR reanalysis and sea surface temperature anomalies (SSTAs) from 1949 to 1998. Evidence indicates that both are influenced by global SSTAs. The SSTA modes generating favorable atmospheric conditions for tropical storms to develop are also in favor of a wet rainfall season in the Sahel and Sudan region. The easterly waves over West Africa become tropical storms only if the atmospheric conditions over the Atlantic are favorable. These conditions are responses to SSTAs. In addition to ENSO, a multidecadal trend mode also plays a role. The positive phase of the trend mode features positive loadings in the North Pacific and the North Atlantic, and negative loadings over the three southern oceans. The positive (negative) phases of both modes are associated with increased (reduced) Atlantic tropical storm activity, and with wet (dry) West African monsoon seasons. The .
Convectively generated gravity waves simulated by NAM‐SCA

Convectively generated gravity waves are an unresolved process in global models. However, parameterization of their effects is difficult because the parameterized wave spectrum must be linked to the convective source, which is itself parameterized. Here we use the NAM‐SCA model (nonhydrostatic anelastic model with segmentally constant approximation), which is midway between a cloud‐resolving model and convection parameterization. Unlike conventional convection parameterizations, NAM‐SCA is built directly upon a nonhydrostatic anelastic model, and thus it describes dynamical processes consistently but in a “compressed” manner (i.e., with truncation via a spatiotemporal adaptive mesh) that facilitates its potential use as a parameterization. As a result, under the dynamical framework of NAM‐SCA, convection generates a spectrum of gravity waves in a physically consistent manner without any additional assumptions or simplifications. The present study examines the capacity of NAM‐SCA for generating gravity waves from convection under varying degree of “compression” and assesses its viability as a physically consistent convective gravity wave source parameterization. By taking the TWP‐ICE (Tropical Warm Pool‐International Cloud Experiment) period for the case study, NAM‐SCA successfully represents the convectively generated gravity waves even down to the compression rate of 0.1. Analysis in the wave number frequency space shows that the compression behaves as a weak low‐pass filter in wave number, but higher‐frequency components generated by dynamic adaptation partially compensate the filtering effect making the net Reynolds stress relatively insensitive to compression.
Simultaneous in situ detection of atmospheric NO3 and N2O5 via cavity ring-down spectroscopy

This article describes the application of cavity ring-down spectroscopy (CaRDS) to the simultaneous concentration measurement of nitrate radical, NO3, and dinitrogen pentoxide, N2O5, in the ambient atmosphere. The sensitivity for detection of both NO3 and N2O5 is 0.5 pptv (2σ) for a 5 s integration, comparable to or better than previous measurements of NO3 (e.g., via DOAS), but with significantly better time resolution. Furthermore, direct measurement of N2O5 represent a previously unavailable capability. Concentrations of both species are measured simultaneously in two separate flow systems and optical cavities pumped by the same pulsed dye laser at 662 nm. One of the flow systems remains at ambient temperature for detection of NO3, while the other is heated to 80 °C to induce thermal decomposition of N2O5 providing a measurement of the sum of the NO3 and N2O5 concentrations. This article outlines a series of laboratory and field tests of the instrument’s performance. Important considerations include sig.
Elastic Wave Generation by Electron Bombardment or Electromagnetic Wave Absorption

S>High-frequency elastic waves produced by electron bombardment or electromagnetic wave absorption are investigated. It is proposed that the incoming beam of electrons or radiant energy produces surface heating with consequent thermal expansion at the surface and propagation of the elastic disturbance. Several experiments supporting this hypothesis are presented. Stainless steel, copper, molybdenum, and Invar were used as the target materials. (C.E.S.)
Boundary approximation of deterministic and random attractors

A result on the boundary of Ω-limit sets, ∂ΩB ⊆ Ω∂B, is shown and used to prove that boundaries of deterministic and random attractors are covered by Ω-limit sets of boundaries of compact sets. As a consequence, a simple algorithm is given to compute the boundary of attractors for a class of gradient systems with additive noise. Computations using this algorithm reveal similar behaviour to that which is already known for one-dimensional systems. In order to apply the algorithm it is shown that any neighbourhood of an absorbing set for certain deterministic systems is an absorbing set for a corresponding stochastic system with positive probability.
Detection of flare like events and their relationship to presumed spot regions on V471 Tau - A solar-stellar connection

Since its discovery as an eclipsing binary with a white dwarf companion by Nelson and Young (1970), V471 Tau (BD + 16 deg 516) has been an object of considerable importance. The K dwarf companion has been the subject of intensive studies because it demonstrates many of the properties normally attributed to classical RS CVn stars. In the present investigation, it is demonstrated that the K dwarf companion exhibits also flaring properties which characterize the BY Dra stars. In a sense, V471 Tau may be the critical link by providing information that the distinctions between RS CVn phenomena and BY Dra phenomena are artificial and misleading, arising entirely from historical processes. Observations in the optical and the X-ray wavelength regions are reported. A study of the occurrence times of flare events in terms of the ephemeris of the photometric wave which is known to migrate through the light curve of V471 Tau reveals a strong correlation, suggesting that the flares occur near regions of the K dwarf where spot groups are inferred.
Speckle Reduction and Edge Detection in Ultrasound Imagery

This thesis investigates the related topics of speckle reduction and edge detection as applied to speckled ultrasonography. A strategy for the evaluation of speckle filters is presented. This includes their application to a large test set of both clinical and simulated images. Functional performance is measured by application of objective image quality metrics, and the relationship between these objective metrics and the subjective opinion of clinical experts is investigated. Finally a detailed analysis of the complexity of the filtering methods is performed to ascertain the computational requirements of the different filters. Edge detection is investigated using Gabor filters to perform orientation-specific multiscale decompositions. The effect of speckle is reduced in the Gabor transforms by MAP estimation. This involves modelling the statistics of the speckle Gabor transform as a combined Gaussian and symmetric α-stable distribution. A technique is proposed for the estimation of the parameters of this model, and its accuracy is demonstrated. Edge detection is achieved by finding the zero crossings of the even-symmetric Gabor coefficients. To suppress the zero crossings which do not correspond to images edges, two observed properties of the Gabor zero crossings are examined. These measurements are combined to form the final edge detector, which is shown to exceed the performance of other edge detectors for speckled imagery. A close relationship exists between edge detection and speckle removal, especially for the diffusion class of filters. The proposed zero crossing edge detector is accordingly incorporated into a tensor-valued diffusion scheme. The performance of this speckle filter is evaluated using the framework proposed in this thesis, and is found to exhibit excellent functional performance.
Modeling drag reduction and meniscus stability of superhydrophobic surfaces comprised of random roughness

Previous studies dedicated to modeling drag reduction and stability of the air-water interface on superhydrophobic surfaces were conducted for microfabricated coatings produced by placing hydrophobic microposts/microridges arranged on a flat surface in aligned or staggered configurations. In this paper, we model the performance of superhydrophobic surfaces comprised of randomly distributed roughness (e.g., particles or microposts) that resembles natural superhydrophobic surfaces, or those produced via random deposition of hydrophobic particles. Such fabrication method is far less expensive than microfabrication, making the technology more practical for large submerged bodies such as submarines and ships. The present numerical simulations are aimed at improving our understanding of the drag reduction effect and the stability of the air-water interface in terms of the microstructure parameters. For comparison and validation, we have also simulated the flow over superhydrophobic surfaces made up of aligned o.
Passivity and passification of stochastic impulsive memristor‐based piecewise linear system with mixed delays

This paper is concerned with the problem of passivity analysis and passification for a class of stochastic impulsive memristor‐based piecewise linear (PWL) systems with mixed delays and nonlinearity disturbances. Based on the PWL memristor, a PWL system is set up. And some novel sufficient conditions are derived to ensure the passivity/passification performance, such that, for all admissible stochastic disturbances and nonlinearity, the closed‐loop stochastic impulsive memristor‐based PWL system is passive in the sense of expectation. Copyright © 2013 John Wiley & Sons, Ltd.
Long-range surface plasmon polaritons

Long-range surface plasmon polaritons (LRSPPs) are optical surface waves that propagate along a thin symmetric metal slab or stripe over an appreciable length (centimeters). Vigorous interest in LRSPPs has stimulated a large number of studies over three decades spanning a broad topical landscape. Naturally, a good segment of the literature covers fundamentals such as modal characteristics, excitation, and field enhancement. But a large portion also involves the LRSPP in diverse phenomena, including nonlinear interactions, molecular scattering, fluorescence, surface-enhanced Raman spectroscopy, transmission through opaque metal films and emission extraction, amplification and lasing, surface characterization, metal roughness and islandization, optical interconnects and integrated structures, gratings, thermo-, electro- and magneto-optics, and (bio)chemical sensing. Despite the breadth and depth of the research conducted to date, much remains to be uncovered, and the scope for future investigations is broad. We review the properties of the LRSPP, survey the literature involving this wave, and discuss the prospects for applications. Avenues for further work are suggested.
Injective hulls in the category of distributive lattices.

This paper deals primarily with the relationship between the notions of injectivity and essential extension in the category D of all distributive lattices and their lattice homomorphisms, the main point being that in D the Situation regarding these notions is fully analogous to what holds in the category of all left modules over a ring [4] or, for that matter, in the category of all partially ordered sets and order preserving mappings [2] (Propositions 2 and 3). An interesting aspect of the results presented here seems to us the manner in which Boolean lattices make their appearance. Thus, it is proved that every distributive lattice has an essential extension which is Boolean (Proposition 1), and the injective hulls in D are shown to be the MacNeille completions of such Boolean essential extensions (Proposition 3). The paper concludes with a discussion of injective hulls and essential extension of some particular types of distributive lattices and a result, already announced without proof in [2], which shows that essential extensions behave very badly in the category of all lattices and lattice homomorphisms).
A redshift survey of IRAS galaxies. VII - The infrared and redshift data for the 1.936 Jansky sample

We present the data for a redshift survey of galaxies selected from the database of the Infrared Astronomical Satellite (IRAS). The sample is flux limited to 1.936 Jy at 60 microns and covers 11.01 sr of the sky. It consists of 5014 objects, of which 2658 are galaxies. The remaining 2356 sources are listed in a separate table with identifications. Redshift data are also given for 212 IRAS galaxies which are not part of the complete sample, but were measured in conjunction with this project.
Nanopinholes-Based Optical Superlens

A type of nanopinhole-based plasmonic structure is presented. It can realize superfocusing within micron-scale propagation distance with spatial resolution beyond diffraction limit. Cut-off wavelength effect is highlighted for understanding how periodicity distribution of the nanopinholes influences transmission and focusing through the structure. Redshift peak transmission occurs while the periodicity increases. In addition, focusing property of the plasmonic structures is analyzed for the monochromatic illumination with different incident wavelengths ranging from 400 nm to 750 nm. The easy fabrication and high focusing performance of the proposed structures may be used in data storage devices, bioimaging, and nanolithography.
A simple model for ion injection and transport in conducting polymers

We present a simple analytical model that describes ion transport in a planar junction between an electrolyte and a conducting polymer film. When ions are injected in the film, holes recede, leading to partial dedoping of the film. This is modeled by two resistors in series, an ionic one for the dedoped part and an electronic one for the still-doped part. We show that analytical predictions can be made for the temporal evolution of the drift length of ions and the current, variables that could be assessed experimentally. A numerical model based on forward time iteration of drift/diffusion equations is used to validate these predictions. Using realistic materials parameters, we find that the analytical model can be used to obtain the ion drift mobility in the film, and as such, it might be useful towards the development of structure vs. ion transport properties relationships in this important class of electronic materials.
Light emission lifetimes in p-type δ-doped GaAs/AlAs multiple quantum wells near the Mott transition

The time resolved photoluminescence of beryllium δ-doped GaAs/AlAs multiple quantum wells have been studied over a range of doping concentrations, in order to investigate possible mechanisms for the carrier radiative recombination, both above and below the Mott metal-insulator transition. It was found that at doping concentrations near the Mott transition (NBe ∼ 3 × 1012 cm−2), the radiative recombination of excitons-bound-to-acceptor impurities as well as free electrons with acceptor impurities, dominated in the Be δ-doped GaAs/AlAs MQWs (LW = 15 nm) that were used in this study. Above the Mott transition, the major contribution was from radiative recombination of free electrons with a two-dimensional hole gas. The radiative lifetime would therefore exhibit different behavior with doping. In lightly doped GaAs/AlAs MQWs, this changed from 0.3–1 ns at 3.6 K to 8 ns at 300 K, whilst in quantum wells above the Mott transition, it changed from ∼0.36 ns at 3.6 K to ∼1 ns at 300 K, and was also weakly dependen.
A direct test of the original version of regret theory

This paper reports on a direct experimental test of the original version of Regret Theory using a total of 64 subjects in three groups. The experiment, which was run on PCs, was designed to elicit from subjects' responses the two key elements in this theory: namely the basic utility function, and the regret/rejoicing function. It was also designed to provide a quick direct test of the implications of the theory. We found that the evidence refuted this original version of Regret Theory.
Duality in Robust Utility Maximization with Unbounded Claim via a Robust Extension of Rockafellar's Theorem

We study the convex duality method for robust utility maximization in the presence of a random endowment. When the underlying price process is a locally bounded semimartingale, we show that the fundamental duality relation holds true for a wide class of utility functions on the whole real line and unbounded random endowment. To obtain this duality, we prove a robust version of Rockafellar's theorem on convex integral functionals and apply Fenchel's general duality theorem.
Early-type semidetached system LY Aurigae

In an effort to resolve a controversy regarding the configuration, mass ratio, and evolutionary status of the early-type close binary system LY Aur, the six bandpass OAO 2 observations of Heap and the ground-based observations combined by Eaton were analyzed. The Wilson and Devinney approach was used. The system is found to be semidetached, with the cooler and less massive component filling its Roche lobe, while the hotter component is close to its Roche surface. The system is not an early-type zero-age contact, as was suspected earlier. 20 references.
A high-performance top-gate graphene field-effect transistor based frequency doubler

A high-performance top-gate graphene field-effect transistor (G-FET) is fabricated, and used for constructing a high efficient frequency doubler. Taking the advantages of the high gate efficiency and low parasitic capacitance of the top-gate device geometry, the gain of the graphene frequency doubler is increased about ten times compared to that of the back-gate G-FET based device. The frequency response of the frequency doubler is also pushed from 10 kHz for a back-gate device to 200 kHz, at which most of the output power is concentrated at the doubled fundamental frequency of 400 kHz.
A short proof of an existence theorem in constructive measure theory

The most important example of an integration space in the constructive measure theory of Bishop and Cheng is the couple (X, 4), where X is a locally compact metric space and a is a nonnegative linear function on the space of continuous functions of compact support on X. Bishop and Cheng's proof that (X, a) is indeed an integration space is rather involved. In this paper a much simpler proof is given. Let (X, d) be a locally compact metric space and let 1t be a nonnegative linear function on the space C of continuous functions on X with compact supports. To rule out trivial cases assume that A(f) > 0 for some f in C. Bishop and Cheng [1] gave a constructive proof for the following Theorem. If (fm)m=o is a sequence of nonnegative functions in C with 11=iI'/m) convergent and less than 1(f0), then there exists an x in X with Ymilfm(x) convergent and less than fo(x). This theorem is the hardest step in showing that (X, 1L) is an integration space as defined in [1]. It has as consequences many existence theorems. The proof given in [1] is rather involved. We now give a much simpler proof. Let K be a compact set outside which fo vanishes. Construct a finite '2-net ty1l **. *. YN of K, and functions in (1 1. Define 91 = i1 and gn = gn1 V in gn1 (1<n<N) Clearly g< 1, and equality holds on K. Therefore, the hypothesis, EiI'Afm) < 1(f0), of the Theorem implies N 00 N E E: tQmGn ) < Y, ILQ Ogn) n=l m =1 n= Hence there exists some n (1 < n < N) such that ' =1L(Imgn) < p(fg0n) Received by the editors March 5, 1974. AMS (MOS) subject classifications (1970). Primary 02E99, 28A30.