Miracle-dz/UniFAR-FTUs huggingface dataset:
Revisiting Dynamical Friction: The Role of Global Modes and Local Wakes

The orbital decay of a perturber within a larger system plays a key role in the dynamics of many astrophysical systems—from nuclear star clusters or globular clusters in galaxies, to massive black holes in galactic nuclei, to dwarf galaxy satellites within the dark matter halos of more massive galaxies. For many decades, there have been various attempts to determine the underlying physics and timescales of the drag mechanism, ranging from the local dynamical friction approach to descriptions based on the back-reaction of global modes induced in the background system. We present ultra-high-resolution N-body simulations of massive satellites orbiting a Milky Way-like galaxy (with > 108 particles), that appear to capture both the local “wake” and the global “mode” induced in the primary halo. We address directly the mechanism of orbital decay from the combined action of local and global perturbations and specifically analyze where the bulk of the torque originates.
Fall and Rise of Nesting Green Turtles (Chelonia mydas) at Aldabra Atoll, Seychelles: Positive Response to Four Decades of Protection (1968–2008)

Abstract When Aldabra Atoll became a nature reserve in 1968, its endangered nesting green turtle (Chelonia mydas) population was the first to be protected in the Indian Ocean. In 1983, Aldabra became a UNESCO World Heritage Site managed by the Seychelles Islands Foundation (SIF). But prior to 1968, its green turtles suffered intense exploitation documented by trade statistics, historical literature, and a scientific study in 1927. Three population surveys conducted just before, during, and shortly after 1968 provide baseline data by which to assess the long-term population recovery monitored since 1980 using a standardized track count protocol. The 52 nesting beaches distributed along the 83-km outer rim of Aldabra were classified into 6 beach groups (WGT, SETT, DDM, DJL, CC, and North), with total beach length of 5.2 km. During Phase 1 (1980–1994) of the study, 17 index beaches (WGT #1–17) were monitored 4 times per month and other beaches opportunistically. During Phase 2 (1994–2008), index beaches (WGT #1–22 and SETT) were monitored at least 4 times per month and remote beaches monthly. Track counts were converted to estimated egg clutch production using nesting success data. Reproductive output for the atoll rose from a mean annual estimated 2000–3000 clutches in the late 1960s to 15,669 (SD = 2776) during 2004–2008, equivalent to a mean estimated 3100–5225 females nesting annually (assuming an average of 3–5 egg clutches per female). This represents a 500%–800% increase during 40 years of complete protection. During Phase 2, the rate of increase was highest at the Settlement Beach (SETT), which had historically suffered the most intense exploitation.
Long term grassland vegetation changes: Case study Nature Park Stara Planina (Serbia)

Changes in grassland flora and vegetation caused by inadequate management, primarily under-grazing and grasslands abandonment were studied in the south-east region of Serbia — Mt. Stara Planina, the largest mountain massif of the country. This mountain is one of the major centres of tertiary and endemic-relict plant species that remains in ravines, and glacial relics and mountain endemic species. The paper presents an analysis and comparison of previous (about 30 years ago) and current biodiversity of the most common grasslands, such as: ass. Festuco-Agrostietum vulgaris, Agrostio-Asphodeletum albae, Koelerietum montanae, Agrostietum vulgaris, Festucetum spadiceae, Nardetum strictae, Poetum molinerii-Plantaginetum carinatae, Poetum violaceae and Seslerietum coerulantis . Both environmental and human impacts on grassland vegetation were discussed and a proposal of sustainable grassland use and management is given.
Fast and principled simulations of the SIR model on temporal networks

The Susceptible–Infectious–Recovered (SIR) model is the canonical model of epidemics of infections that make people immune upon recovery. Many of the open questions in computational epidemiology concern the underlying contact structure’s impact on models like the SIR model. Temporal networks constitute a theoretical framework capable of encoding structures both in the networks of who could infect whom and when these contacts happen. In this article, we discuss the detailed assumptions behind such simulations—how to make them comparable with analytically tractable formulations of the SIR model, and at the same time, as realistic as possible. We also present a highly optimized, open-source code for this purpose and discuss all steps needed to make the program as fast as possible.
Langevin Monte Carlo: random coordinate descent and variance reduction

Sampling from a log-concave distribution function on $\mathbb{R}^d$ (with $d\gg 1$) is a popular problem that has wide applications. In this paper we study the application of random coordinate descent method (RCD) on the Langevin Monte Carlo (LMC) sampling method, and we find two sides of the theory: 1. The direct application of RCD on LMC does reduce the number of finite differencing approximations per iteration, but it induces a large variance error term. More iterations are then needed, and ultimately the method gains no computational advantage; 2. When variance reduction techniques (such as SAGA and SVRG) are incorporated in RCD-LMC, the variance error term is reduced. The new methods, compared to the vanilla LMC, reduce the total computational cost by $d$ folds, and achieve the optimal cost rate. We perform our investigations in both overdamped and underdamped settings.
Information Relaxation and A Duality-Driven Algorithm for Stochastic Dynamic Programs

We use the technique of information relaxation to develop a duality-driven iterative approach to obtaining and improving confidence interval estimates for the true value of finite-horizon stochastic dynamic programming problems. We show that the sequence of dual value estimates yielded from the proposed approach in principle monotonically converges to the true value function in a finite number of dual iterations. Aiming to overcome the curse of dimensionality in various applications, we also introduce a regression-based Monte Carlo algorithm for implementation. The new approach can be used not only to assess the quality of heuristic policies, but also to improve them if we find that their duality gap is large. We obtain the convergence rate of our Monte Carlo method in terms of the amounts of both basis functions and the sampled states. Finally, we demonstrate the effectiveness of our method in an optimal order execution problem with market friction and in an inventory management problem in the presence of lost sale and lead time. Both examples are well known in the literature to be difficult to solve for optimality. The experiments show that our method can significantly improve the heuristics suggested in the literature and obtain new policies with a satisfactory performance guarantee.
Associating Uncertainty to Extended Poses for on Lie Group IMU Preintegration With Rotating Earth

The recently introduced matrix group <inline-formula><tex-math notation="LaTeX">$\mathbf {SE_2(3)}$</tex-math></inline-formula> provides a 5<inline-formula><tex-math notation="LaTeX">$\mathbf {\times }$</tex-math></inline-formula>5 matrix representation for the orientation, velocity, and position of an object in the 3-D space, a triplet we call “extended pose. ” In this article, we build on this group to develop a theory to associate uncertainty with extended poses represented by 5<inline-formula><tex-math notation="LaTeX">$\mathbf {\times }$</tex-math></inline-formula>5 matrices. Our approach is particularly suited to describe how uncertainty propagates when the extended pose represents the state of an inertial measurement unit (IMU). In particular, it allows revisiting the theory of IMU preintegration on manifold and reaching a further theoretic level in this field. Exact preintegration formulas that account for rotating earth, that is, centrifugal force and Coriolis force, are derived as a byproduct, and the factors are shown to be more accurate. The approach is validated through extensive simulations and applied to sensor fusion where a loosely coupled fixed-lag smoother fuses IMU and LiDAR on 1-h-long experiments using our experimental car. It shows how handling rotating earth may be beneficial for long-term navigation within incremental smoothing algorithms.
Index Coding at the WiFi Edge: An Implementation Study for Video Delivery

HTTP based video streaming has become the de facto standard for video content delivery across different video streaming services. However, video content delivery continues to be challenged at the wireless edge by inadequate and highly variable bandwidth. In this paper, we describe WiCode, a platform that improves HTTP based video content delivery at the WiFi edge. WiCode uses coded delivery at the WiFi AP to reduce data transmissions in order to improve the perceived performance of video streaming at the users. WiCode performs index coding on video segments to reduce the number of bits transmitted. Further, it also performs index coding on UDP packets that are retransmitted to reduce the number of bits transmitted. This paper describes the design and implementation of WiCode, and the practical gains achievable due to employing coded delivery in a real system taking into account the overheads introduced by WiCode. The WiCode module at the client side is a browser plugin that does not require any client side device configuration changes. We also show the effect of variable and fixed length segment size on the perceived performance of WiCode.
Deep Learning for Direction of Arrival Estimation via Emulation of Large Antenna Arrays

We present a MUSIC-based Direction of Arrival (DOA) estimation strategy using small antenna arrays, via employing deep learning for reconstructing the signals of a virtual large antenna array. Not only does the proposed strategy deliver significantly better performance than simply plugging the incoming signals into MUSIC, but surprisingly, the performance is also better than directly using an actual large antenna array with MUSIC for high angle ranges and low test SNR values. We further analyze the best choice for the training SNR as a function of the test SNR, and observe dramatic changes in the behavior of this function for different angle ranges.
Off-policy Evaluation in Infinite-Horizon Reinforcement Learning with Latent Confounders

Off-policy evaluation (OPE) in reinforcement learning is an important problem in settings where experimentation is limited, such as education and healthcare. But, in these very same settings, observed actions are often confounded by unobserved variables making OPE even more difficult. We study an OPE problem in an infinite-horizon, ergodic Markov decision process with unobserved confounders, where states and actions can act as proxies for the unobserved confounders. We show how, given only a latent variable model for states and actions, policy value can be identified from off-policy data. Our method involves two stages. In the first, we show how to use proxies to estimate stationary distribution ratios, extending recent work on breaking the curse of horizon to the confounded setting. In the second, we show optimal balancing can be combined with such learned ratios to obtain policy value while avoiding direct modeling of reward functions. We establish theoretical guarantees of consistency, and benchmark our method empirically.
Development of helical vortex theory

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Development of helical vortex theory Valery Okulov
A GENOMIC SCREEN FOR ZIC1 TARGET GENES IN NEURAL DEVELOPMENT

The transcription factor Zic1 plays important roles in patterning the neural plate in early vertebrate development. A crucial step toward understanding the mechanisms of Zic1 function is to identify the downstream target genes. We misexpressed Zic1 in animal caps from Xenopus embryos, and screened for differential gene expression with DNA microarrays. Candidate genes from these microarray data were further validated by quantitative PCR. Through this study, eleven genes have been shown to be directly upregulated by Zic1. One of the direct targets of Zic1 is a novel gene that we have named Xfeb. Xfeb is expressed in the presumptive hindbrain region during neurula stages and in somite tissues later in development. Xfeb represses the hindbrain gene hoxB1 and the anterior neural gene otx2, suggesting that Xfeb is involved in regionalizing the neural plate, possibly by ensuring a posterior expression limit for otx2.
Physics and Chemistry of Clouds: Transformations

Clouds affect our daily weather and play key roles in the global climate. Through their ability to precipitate, clouds provide virtually all of the fresh water on Earth and are a crucial link in the hydrologic cycle. With ever-increasing importance being placed on quantifiable predictions - from forecasting the local weather to anticipating climate change - we must understand how clouds operate in the real atmosphere, where interactions with natural and anthropogenic pollutants are common. This textbook provides students - whether seasoned or new to the atmospheric sciences - with a quantitative yet approachable path to learning the inner workings of clouds. Developed over many years of the authors' teaching at Pennsylvania State University, Physics and Chemistry of Clouds is an invaluable textbook for advanced students in atmospheric science, meteorology, environmental sciences/engineering and atmospheric chemistry. It is also a very useful reference text for researchers and professionals.
Radiative Flux Estimation from a Broadband Radiometer Using Synthetic Angular Models in the EarthCARE Mission Framework. Part I: Methodology

AbstractThe instantaneous top-of-atmosphere (TOA) radiance-to-flux conversion for the broadband radiometer (BBR) on board the Earth Clouds, Aerosols, and Radiation Explorer (EarthCARE) was assessed in Part I of this paper, by developing theoretical angular distribution models (ADMs) specifically designed for the instrument viewing configuration. This paper validates the BBR ADMs by comparing derived flux estimates with flux retrievals obtained from the Clouds and the Earth’s Radiant Energy System (CERES) Terra models. A CERES BBR-like database is employed in the assessment, which is an optimum dataset to validate the BBR algorithms and to determine the benefits of the multiangular conversion procedures in the BBR instrument. The validation of theoretical results with empirical data is essential to prepare the conversion algorithms prior to the launch of EarthCARE. This paper demonstrates that the application of a linear combination method is not recommended when outgoing radiances do not follow the respon.
14-3-3σ Positively Regulates p53 and Suppresses Tumor Growth

ABSTRACT The 14-3-3σ (sigma) protein, a negative regulator of the cell cycle, is a human mammary epithelium-specific marker that is downregulated in transformed mammary carcinoma cells. It has also been identified as a p53-inducible gene product involved in cell cycle checkpoint control after DNA damage. Although 14-3-3σ is linked to p53-regulated cell cycle checkpoint control, detailed mechanisms of how cell cycle regulation occurs remain unclear. Decreased expression of 14-3-3σ was recently reported in several types of carcinomas, further suggesting that the negative regulatory role of 14-3-3σ in the cell cycle is compromised during tumorigenesis. However, this possible tumor-suppressive role of 14-3-3σ has not yet been characterized. Here, we studied the link between 14-3-3σ activities and p53 regulation. We found that 14-3-3σ interacted with p53 in response to the DNA-damaging agent adriamycin. Importantly, 14-3-3σ expression led to stabilized expression of p53. In studying the molecular mechanism of this increased stabilization of p53, we found that 14-3-3σ antagonized the biological functions of Mdm2 by blocking Mdm2-mediated p53 ubiquitination and nuclear export. In addition, we found that 14-3-3σ facilitated the oligomerization of p53 and enhanced p53's transcriptional activity. As a target gene of p53, 14-3-3σ appears to have a positive feedback effect on p53 activity. Significantly, we also showed that overexpression of 14-3-3σ inhibited oncogene-activated tumorigenicity in a tetracycline-regulated 14-3-3σ system. These results defined an important p53 regulatory loop and suggested that 14-3-3σ expression can be considered for therapeutic intervention in cancers.
Messages on the move: the role of the cytoskeleton in mRNA localization and translation in plant cellsThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.

The cytoskeleton plays an important role in numerous cellular processes, including subcellular mRNA localization and translation. Several examples of mRNA localization have emerged in plant cells, and these appear to function in protein targeting, the establishment of polarity, and cell-to-cell trafficking. The identification of several cytoskeleton-associated RNA-binding proteins in plant cells has made available candidate proteins that mediate the interaction between mRNA and the cytoskeleton, and possibly play a role in mRNA localization and translational control. We propose a model that links mRNA–microtubule interactions to translational autoregulation, a process that may assist in the efficient and regulated binding of proteins to microtubules.
Scalpel-CD: Leveraging Crowdsourcing and Deep Probabilistic Modeling for Debugging Noisy Training Data

This paper presents Scalpel-CD, a first-of-its-kind system that leverages both human and machine intelligence to debug noisy labels from the training data of machine learning systems. Our system identifies potentially wrong labels using a deep probabilistic model, which is able to infer the latent class of a high-dimensional data instance by exploiting data distributions in the underlying latent feature space. To minimize crowd efforts, it employs a data sampler which selects data instances that would benefit the most from being inspected by the crowd. The manually verified labels are then propagated to similar data instances in the original training data by exploiting the underlying data structure, thus scaling out the contribution from the crowd. Scalpel-CD is designed with a set of algorithmic solutions to automatically search for the optimal configurations for different types of training data, in terms of the underlying data structure, noise ratio, and noise types (random vs. structural). In a real deployment on multiple machine learning tasks, we demonstrate that Scalpel-CD is able to improve label quality by 12.9% with only 2.8% instances inspected by the crowd.
DRUMBEAT: In Search of Belonging

DRUMBEAT is a flexible program that combines experiential learning with Cognitive Behavioural Therapy, and engages young people and adults who may be anxious or resistant to 'talk based' therapies. The DRUMBEAT program is taught to young people and adults across Australia in schools, youth services, drug and alcohol rehabilitation facilities, child protection residential facilities, mental health services, refugee trauma associations and prisons. Participants lift their self-esteem, learn to work cooperatively with others and are exposed to the therapeutic and recreational benefits of music. The program is a useful tool, effective at engaging a wide range of young people and practical in its application.
Induced chlorophyll mutations in Delphinium malabaricum (Huth) Munz.

The phenotypic response of Delphinium malabaricum to chemical mutagens (EMS and SA) and physical mutagen (gamma rays) were studied. It was observed that D. malabaricum manifested specifi c reactions to the treatments with EMS, SA and gamma rays. Different mutation frequencies and width of mutation spectra were induced under the action of different concentrations of the applied mutagens. Eleven different types of chlorophyll mutants namely albina, albina-green, xantha, aurea, chlorina, viridis, yellow viridis, tigrina, striata, maculata and variegated type were identifi ed in the treated populations and chlorophyll mutation frequency was calculated on plant population basis. Frequency of viridis mutants were highest followed by xantha and other types in all the treatments. The treatments of EMS were found to be more effi cient than SA and gamma rays in inducing chlorophyll mutations. The highest frequency of chlorophyll mutations (9.74%) was reported in the 0.25% EMS. Quantitative estimation of chlorophyll pigments was also done in different kinds of chlorophyll mutants and chlorophyll content was found in the following decreasing order: chlorina > maculata> variegated> striata> tigrina> viridis> yellow viridis> albina green> aurea> xantha > albina. The study of induced genetic variability for frequency and spectrum of chlorophyll mutations is the fi rst report in D. malabaricum.
The north-eastern distribution range of European beech—a review

Summary Today, European beech ( Fagus sylvatica L.) seems to be a markedly successful tree species in the north-east of its distribution range. The distribution area may be larger than originally assumed; past forest management is probably the main cause of the contraction in the postglacial European beech range. Numerous attempts consistently have failed to locate a distinct distribution edge for European beech. Therefore, we defi ne northern and eastern Poland and the southern regions of the Baltic States as margins of European beech distribution. Ecophysiological approaches have identifi ed the drought constraints for European beech in terms of (1) the critical limit for xylem cavitation and loss of hydraulic conductivity, reached at a shoot water potential of – 1.9 MPa, and (2) a reduction in gross primary production and total ecosystem respiration when relative extractable soil water reaches 40 and 20 per cent, respectively. However, it is diffi cult to correlate European beech distribution margins with single macro-climatic factors. Moreover, the adaptation of European beech populations and provenances to drought and frost varies. The phenotypic plasticity and evolutionary adaptability of European beech appear to be underestimated. These characteristics may counteract a further contraction of the European beech range arising from climate change in the future.
Epidemiological analysis on the characteristics and related factors of HIV/AIDS in 50-year and older Chinese population

长期以来,15～49岁人群是HIV感染的高危及主要人群,但近年来我国艾滋病疫情报告系统显示≥50岁年龄组HIV感染者和艾滋病患者(HIV/AIDS)报告数及构成比有增多趋势. 随着全球范围老龄化问题的出现,≥50岁年龄组人群的HIV感染状况开始引起社会关注[1]. 为了解我国中老年人群艾滋病疫情特点及流行因素,本研究对我国≥50岁年龄组HIV/AIDS报告病例进行分析。