Miracle-dz/UniFAR-FTUs huggingface dataset:
Multiscale Metamorphic VAE for 3D Brain MRI Synthesis

Generative modeling of 3D brain MRIs presents difficulties in achieving high visual fidelity while ensuring sufficient coverage of the data distribution. In this work, we propose to address this challenge with composable, multiscale morphological transformations in a variational autoencoder (VAE) framework. These transformations are applied to a chosen reference brain image to generate MRI volumes, equipping the model with strong anatomical inductive biases. We structure the VAE latent space in a way such that the model covers the data distribution sufficiently well. We show substantial performance improvements in FID while retaining comparable, or superior, reconstruction quality compared to prior work based on VAEs and generative adversarial networks (GANs).
Min-Max Optimization Made Simple: Approximating the Proximal Point Method via Contraction Maps

In this paper we present a first-order method that admits near-optimal convergence rates for convex/concave min-max problems while requiring a simple and intuitive analysis. Similarly to the seminal work of Nemirovski and the recent approach of Piliouras et al. in normal form games, our work is based on the fact that the update rule of the Proximal Point method (PP) can be approximated up to accuracy $\epsilon$ with only $O(\log 1/\epsilon)$ additional gradient-calls through the iterations of a contraction map. Then combining the analysis of (PP) method with an error-propagation analysis we establish that the resulting first order method, called Clairvoyant Extra Gradient, admits near-optimal time-average convergence for general domains and last-iterate convergence in the unconstrained case.
Cross-Model Comparative Loss for Enhancing Neuronal Utility in Language Understanding

Current natural language understanding (NLU) models have been continuously scaling up, both in terms of model size and input context, introducing more hidden and input neurons. While this generally improves performance on average, the extra neurons do not yield a consistent improvement for all instances. This is because some hidden neurons are redundant, and the noise mixed in input neurons tends to distract the model. Previous work mainly focuses on extrinsically reducing low-utility neurons by additional post- or pre-processing, such as network pruning and context selection, to avoid this problem. Beyond that, can we make the model reduce redundant parameters and suppress input noise by intrinsically enhancing the utility of each neuron? If a model can efficiently utilize neurons, no matter which neurons are ablated (disabled), the ablated submodel should perform no better than the original full model. Based on such a comparison principle between models, we propose a cross-model comparative loss for a broad range of tasks. Comparative loss is essentially a ranking loss on top of the task-specific losses of the full and ablated models, with the expectation that the task-specific loss of the full model is minimal. We demonstrate the universal effectiveness of comparative loss through extensive experiments on 14 datasets from 3 distinct NLU tasks based on 5 widely used pretrained language models and find it particularly superior for models with few parameters or long input.
Study of neutrino mass matrices with vanishing trace and one vanishing minor

In this work we carry out a systematic texture study of the neutrino mass matrix with the ansatzes - (i) one vanishing minor and (ii) the zero sum of the mass eigenvalues with the CP phases (henceforth vanishing trace). There are six possible textures of a neutrino mass matrix with one vanishing minor. The viability of each texture is checked with $3\sigma$ values of current neutrino data by drawing scatter plots. In our analysis we are motivated to use the ratio of solar to atmospheric mass-squared differences $R_{\nu}$ for its precise measurement (and also the atmospheric mixing angle $\theta_{23}$) to constrain phenomenologically first the Dirac CP phase $\delta$ in the range of $0^{\degree}-360^{\degree}$ for a given texture with the solutions of the constraint equations. Subsequently we employ this constrained $\delta$ to determine the range of completely unknown Majorana CP Phases ($\alpha$ and $\beta$) for all the viable textures. We also check the neutrinoless double beta decay rate, $|m_{ee}|$ and the Jarlskog invariant, $J_{cp}$ for the textures. Finally the symmetry realization of all the viable textures under the flavor symmetry group $Z_5$ via seesaw mechanism is implemented along with the FN mechanism to determine mass hierarchy structure.
Composite-boson formalism applied to strongly bound fermion pairs in a one-dimensional trap

We analyze a system of fermions in a one dimensional harmonic trap with attractive delta-interactions between different fermions species, as an approximate description of experiments involving atomic dimers. We solve the problem of two fermion pairs numerically using the so-called "coboson formalism" as an alternative to techniques which are based on the single-particle basis. This allows us to explore the strongly bound regime, approaching the limit of infinite attraction in which the composite particles behave as hard-core bosons. Our procedure is computationally inexpensive and illustrates how the coboson toolbox is useful for ultracold atom systems even in absence of condensation.
Constraints On Dark Matter From Reionization

This conference proceedings paper provides a short summary of the constraints presented in Menci et al. 2016, 2017 on the mass of thermal WDM candidates, and of the results presented in Romanello et al. 2021 on how Reionization scenarios are affected by early galaxy formation in WDM cosmologies. The abundance of galaxies in the epoch of reionization ($z>$6) is dependent on fundamental cosmological parameters, most importantly on the properties of dark matter, such that it can be used as a powerful cosmological probe. Here we show how the number density of primordial galaxies allows to constrain the mass of thermal WDM candidates, and we discuss the constraints that will be made possible by future JWST observations. We then investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in thermal Warm Dark Matter and sterile neutrino cosmologies. For each cosmology, we find an upper limit to fixed $f_{esc}$, which guarantees the completion of the process at $z<6.7$.
Quasi-periodic wind variations with height in the lower stratosphere

Quasi-periodic wind variations with height have been commonly observed in the lower stratosphere by means of the radar-sonde theodolite at Crawley. The atmospheric disturbances which give rise to these wind variations have a vertical dimension of 1 km or so, but their horizontal dimensions must be much greater, perhaps of the order of several hundred kilometers. Perturbation theory is used to show that slow ‘inertia oscillations’ with a period of the order of half a day might have such dimensions.
Adaptive Control Design Methodology for Nonlinear-in-Control Systems in Aircraft Applications

An adaptive control design method for both short-period and lateral/directional control of a fighter aircraft is presented. The proposed method is directly applicable to flight control of vehicles with state-dependent and nonlinear-in-control uncertain dynamics. The developed design approach uses a specialized set of radial basis function approximators and Lyapunov-based adaptive laws to compensate for the unknown control-dependent nonlinearities. The adaptive controller is defined as a solution of fast dynamics, which verifies the assumptions of Tikhonov’s theorem from singular perturbations theory. Simulations illustrate the theoretical findings.
Transient phenomena analysis using dynamic speckle patterns

The full width at half maximum (FWHM) is sometimes used to characterize the autocorrelation function of the time history of a speckle pattern. We propose to include more autocorrelation points to diminish the variability of the measurement. The width of the equivalent rectangle (WER) and the X*LOG X measurements are defined and some simulations and experimental results obtained are shown.
DNA fragility at the KMT2A/MLL locus: insights from old and new technologies

The Mixed-Lineage Leukaemia (MLL/KMT2A) gene is frequently rearranged in childhood and adult acute leukaemia (AL) and in secondary leukaemias occurring after therapy with DNA topoisomerase targeting anti-cancer agents such as etoposide (t-AL). MLL/KMT2A chromosome translocation break sites in AL patients fall within an 8 kb breakpoint cluster region (BCR). Furthermore, MLL/KMT2A break sites in t-AL frequently occur in a much smaller region, or hotspot, towards the 3′ end of the BCR, close to the intron 11/exon 12 boundary. These findings have prompted considerable effort to uncover mechanisms behind the apparent fragility of the BCR and particularly the t-AL hotspot. Recent genome-wide analyses have demonstrated etoposide-induced DNA cleavage within the BCR, and it is tempting to conclude that this cleavage explains the distribution of translocation break sites in t-AL. However, the t-AL hotspot and the centre of the observed preferential DNA cleavage are offset by over 250 nucleotides, suggesting additional factors contribute to the distribution of t-AL break sites. We review these recent genomic datasets along with older experimental results, analysis of TOP2 DNA cleavage site preferences and DNA secondary structure features that may lead to break site selection in t-AL MLL/KMT2A translocations.
Medicinal plants as a cellulose source for the fabrication of poly(lactic acid) composites: A mini-review

More recently, natural polymers produced by living organisms have received considerable attention due to their unique properties such as eco-friendliness, biodegradability, and biocompatibility. These polymers possess similar properties to conventional plastics, making them suitable potential plastic substitutes for sustainable development and conservation of finite oil resources. Poly(lactic acid) (PLA) is comparable to commonly used plastics but is inferior, thus limited applications. However, PLA can benefit from the incorporation of various polymer components with complementary properties to yield improved physical properties. The fabrication of fully bio-based nanocomposites such as that of PLA and cellulose is of particular interest to research scientists. Incorporating organic fillers such as nanocellulose in a PLA matrix gives rise to improved composite properties. Because plant cell walls comprise semicrystalline cellulose molecules embedded in matrices, the crystalline portion of the stiff chains extracted from medicinal plants is currently exploited for potential filler roles. In this review, the use of medicinal plants in bio-based composite applications is covered. Several medicinal plants as sources of cellulose, different cellulose extraction methods, as well as the resulting fiber properties, are discussed. Although tremendous progress has been made in developing biocomposites, a lot of research still needs to be carried out.
Physics of the enhancement of impact ionization in multiquantum well structures

We present an analytical theory of the experimentally observed enhanced impact ionization rate in multiquantum well structures, which is based on a modification of Schockley’s [Solid State Electron. 2, 35 (1961)] lucky electron theory. The general expression always predicts an enhancement in the ionization rate over the corresponding bulk value. The model is compared to both Monte Carlo calculations and recent experimental results. It is concluded that owing to the nonlinear aspects of impact ionization, the ionization rate can be significantly enhanced by the superposition of a uniform electric field and any spatially periodic electric field.
A broadband, self-powered, and polarization-sensitive PdSe2 photodetector based on asymmetric van der Waals contacts

Abstract Self-powered photodetectors with broadband and polarization-sensitive photoresponse are desirable for many important applications such as wearable electronic devices and wireless communication systems. Recently, two-dimensional (2D) materials have been demonstrated as promising candidates for self-powered photodetectors owing to their advantages in light–matter interaction, transport, electronic properties, and so on. However, their performance in speed, broadband response, and multifunction is still limited. Here, we report a PdSe2 photodetector with asymmetric van der Waals (vdWs) contacts formed by using a homojunction configuration. This device achieves a high responsivity approaching 53 mA/W, a rise/decay time of about 0.72 ms/0.24 ms, and a detectivity of more than 5.17 × 1011 Jones in the visible-near infrared regime (532–1470 nm). In addition, a linear polarization-sensitive response can be observed with an anisotropy ratio of 1.11 at 532 nm and 1.62 at 1064 nm. Furthermore, a strong anisotropic response endows this photodetector with outstanding polarization imaging capabilities, realizing a contrast-enhanced degree of linear polarization imaging. Our proposed device architecture demonstrated the great potential of PdSe2-based asymmetric vdWs contacts for high-performance photodetectors operating without any external bias.
Is Sustainable Development Really Sustainable – Theoretical Reflections, Statistics and the Need for Changes

Abstract The aim of the article is to explain holistically the main provisions of sustainable development in the nature-society-human system based on the methodology for analyzing changes in energy flows and the power of socio-economic systems. The authors consider the development of society as a creative process aimed at changing the direction and speed of free energy flows (useful power) in Space and Time. They also consider sustainable development in the nature-society-human system to be consistent with the laws of the global evolution of living nature and the laws of the historical development of humankind. The paper focuses on key questions concerning the new concepts of sustainable development; the methodology for designing the sustainable development using the concept of energy flows in open, non-equilibrium stable systems and power change analysis approach. The results of the main positions of the models and their interpretation are presented based on the statistical data of United States of America (USA) in the period of 1960–2021. One of the most important primary things in order to bring about changes in people's thinking, understanding and attitude towards sustainability issues is their education in different forms – formal education and non-formal education opportunities. Creating an interdisciplinary approach and explaining sustainability as a set of economic, social and ecological factors also play a crucial role in raising public awareness of sustainability issues.
Microscopic origin of slow dynamics at the good glass forming composition range in Zr1-xCux metallic liquids

We have studied the structure and dynamics of a series of Zr1−xCux metallic liquids at temperatures of 1500 and 1300 K. We found that as the Cu composition increases, the Zr–Zr order undergoes considerable transition, which can be attributed to the different size of Zr and Cu atoms. The diffusivities of both Cu and Zr atoms become lower at the composition range corresponding to good glass forming region, i.e., 0.50≤x≤0.70. We found that the lower diffusivities for the intermediate composition range are correlated with the concentration of some specific clusters, including icosahedra, which can be screened out automatically and unbiasedly by using direct atomic dynamics analysis. Our analysis for the dynamic properties of high temperature liquids of ZrCu metallic alloys shows that the icosahedral clusters together with some other pentagon-rich Voronoi clusters are responsible for slowing dynamics. Cluster lifetime analysis indicates that the slow clusters mobility could be originated in their energy.
Light scattering from multilayer optics. I. Tools of investigation

We emphasize the role of correlated isotropy in the study of microroughness in high-quality optical coatings. First, cross correlation between surfaces and cross coherence between scattering sources are discussed and compared. An isotropy degree of roughness is then introduced as a quantitative value to describe the angular disorder of a surface connected with the polar dependence of scattering. We show how the frequency variations of this isotropy degree allow one to solve the inverse problem and obtain a unique solution for the scattering parameters that describe structural irregularities of the stacks. Light scattering can also be used to detect an oblique growth of the materials in thin-film form. Finally, we study the sensitivity of the investigation method to the stack parameters.
Kosterlitz‐Thouless transition in two‐dimensional planar ferromagnet K2CuF4 (invited)

We report that in 2D planar ferromagnet K2CuF4 the Kosterlitz‐Thouless transition occurs in a slightly modified form by the weak 3D interaction. K2CuF4 is a good 2D ferromagnet, but by no means a true XY magnet, the anisotropic part of interaction being only 1%. Nevertheless, it is approximated by a good 2D XY magnet at low temperatures. We have carried out static magnetization as well as neutron scattering measurements and found that all the critical parameters δ(T), χ(T), κ(T), ξ(T) and η(T) determined in the 2D XY‐like crossover regime are in good agreement with the Kosterlitz theory and the Monte Carlo simulation. The existence of the universal jump in Jeff is also indicated through the diffuse scattering measurements.
A TEST OF THICK-TARGET NONUNIFORM IONIZATION AS AN EXPLANATION FOR BREAKS IN SOLAR FLARE HARD X-RAY SPECTRA

Solar nonthermal hard X-ray (HXR) flare spectra often cannot be fitted by a single power law, but rather require a downward break in the photon spectrum. A possible explanation for this spectral break is nonuniform ionization in the emission region. We have developed a computer code to calculate the photon spectrum from electrons with a power-law distribution injected into a thick target in which the ionization decreases linearly from 100% to zero. We use the bremsstrahlung cross section from Haug, which closely approximates the full relativistic Bethe–Heitler cross section, and compare photon spectra computed from this model with those obtained by Kontar et al., who used a step-function ionization model and the Kramers approximation to the cross section. We find that for HXR spectra from a target with nonuniform ionization, the difference (Δγ) between the power-law indexes above and below the break has an upper limit between ∼0.2 and 0.7 that depends on the power-law index δ of the injected electron distribution. A broken power-law spectrum with a higher value of Δγ cannot result from nonuniform ionization alone. The model is applied to spectra obtained around the peak times of 20 flares observed by the Ramaty High-Energy Solar Spectroscopic Imager from 2002 to 2004 to determine whether thick-target nonuniform ionization can explain the measured spectral breaks. A Monte Carlo method is used to determine the uncertainties of the best-fit parameters, especially on Δγ. We find that 15 of the 20 flare spectra require a downward spectral break and that at least six of these could not be explained by nonuniform ionization alone because they had values of Δγ with less than a 2.5% probability of being consistent with the computed upper limits from the model. The remaining nine flare spectra, based on this criterion, are consistent with the nonuniform ionization model.
Microbially driven fate of terrigenous particulate organic matter in oceans

A long‐standing enigma in oceanography is why terrestrial organic matter is “missing” in the global ocean, despite the considerable discharge into it every year. Although some explanations, such as mineralogical composition, hydrodynamic processes, and priming effect, have been proposed, we hypothesize that the essential mechanism behind the missing organic matter is microbial processing, for which the underlying coupled geochemical, molecular, and genetic evidence is unknown. An ultra‐large‐volume, long‐term river–seawater stratified simulation system was constructed to unravel the microbially driven fate of terrigenous particulate organic matter (POM) in oceans. Analysis of combining the molecular with POM chemical composition data suggests that Bacteroidetes could act as pioneers in the processing of terrigenous POM in oceans, degrading high‐molecular‐weight, high‐carbon compounds such as polysaccharides. Remaining low‐molecular‐weight nitrogenous organic matter is subsequently degraded by Planctomycetes and Proteobacteria. Isotopic signals show that this preferential degradation causes a distinct “aging” effect of POM, and along with nitrification enhanced by remineralization, causes a decrease in the POM C : N ratio. Degradation of terrigenous POM and bacterial biomass biosynthesis leads to positive deviations in δ15N and δ13C. Relatively refractory hydrocarbons, aromatic compounds, and phenols are accumulated by microbial processes in this system. This study provides mechanistic insights into the missing chemical and isotopic signals and microbially driven fate of terrigenous POM in the ocean, with important implications for how riverine material input affects marine carbon and nitrogen cycling.
Educated perception

Given the preponderance of disinformation and denialism, research plays a vital role in truth-telling and shaping public opinion. While opinions have objective and subjective elements, what proves to be crucial in avoiding baseless claims is educated perception. The rightness or wrongness of perceptions may be determined by cognitive (knowledge), conative (actions) and affective (feeling) aspects (Walgito, 2010). In media practice, editorial decisions should be based on the right information coming from reliable sources. This is much easier said than done as “fake news” has become an industry (Ong & Caba~ nes, 2018). Vosoughi et al. (2018) also stressed that lies, misinformation, and disinformation tend to spread faster than the truth. That there are certain groups and individuals who deny basic truths on issues like human rights violations and climate change make the task of truth-telling even more challenging and even frustrating. May we all be armed with the right education and perception in fighting disinformation and denialism.
Hypothalamic Protein Profiling from Mice Subjected to Social Defeat Stress

The Hypothalmic-pituitary axis also known as the HPA axis is central to stress response. It also acts as the relay centre between the body and the brain. We analysed hypothalamic proteome from mice subjected to chronic social defeat paradigm using iTRAQ based quantitative proteomics in identify changes associated with stress response. We identified greater than 2000 proteins processing our samples analysed through Q-Exactive (Thermo) and Orbitrap Velos (Thermo) at 5% FDR. Analysis of data procured from the runs showed that the proteins whose levels were affected belonged primarily to mitochondrial and metabolic processes, translation, complement pathway among others. We also found increased levels of fibrinogen, myelin basic protein (MBP) and neurofilaments (NEFL, NEFM, NEFH) in the hypothalamus from socially defeated mice. Interestingly these proteins are found upregulated in blood and CSF of subjects exposed to trauma and stress. Since hypothalamus is in direct contact of blood and CSF, their utility as biomarkers in depression holds an impressive probability and should be validated in clinical samples.