Miracle-dz/UniFAR-FTUs huggingface dataset:
Consistent Estimation of Dynamic Panel Data Models With Cross-sectional Dependence

This paper proposes new moment estimators for autoregressive panels with crosssectional dependence. In particular, for each unit i the proposed estimators make use of instruments with respect to another cross-section, unit j, rather than with respect to lagged values of the endogenous regressor (either in levels or in rstdi¤erences) of unit i itself. This is a rather di¤erent approach compared to the conventional one applied in the dynamic panel literature. The resulting estimators are asymptotically valid when the time dimension of the panel is xed. The nitesample evidence of the Monte Carlo experiments suggests that the new moment estimators are by far superior in terms of bias and RMSE compared to the existing ones, under cross-sectional dependence in the error process. Key Words: dynamic panel data, cross-sectional dependence, generalised method of moments, Sargans test. JEL Classi cation: C12; C13; C15; C33. 1 Introduction In dynamic panel data models, it is well known that the xed e¤ects estimator hereafter FE is biased for nite T (the number of time series observations), and this result holds regardless of the number of cross-sections observed in the sample, N . 1 To tackle this problem, applied economic research usually follows the practice of rst-di¤erencing the data and then using an estimator based either on instrumental variables (such as the Anderson-Hsiao estimator, 1981), or on the generalised method of moments (GMM), proposed by Arellano and Bond (1991), Arellano and Bover (1995), Ahn and (1995) and Blundell and Bond (1998). These estimators are consistent for xed T , however, this property hinges crucially upon the assumption that the cross-sectional units are independently drawn, such that the only characteristic giving merit to the panel structure of the sample is a set of common coe¢ cients shared by all individuals. Recently, this Discipline of Econometrics and Business Statistics, University of Sydney, NSW 2006, Australia. Tel: +61-2-9036 9120; e-mail: v.sara dis@econ.usyd. edu.au. See Nickell (1981).
Retina Anatomic Response to Intravitreal Dexamethasone Implant and Baseline Aqueous Humor Cytokine Levels in Diabetic Macular Edema

Citation: Figueras-Roca M, Sala-Puigdollers A, Zarranz-Ventura J, et al. Anatomic response to intravitreal dexamethasone implant and baseline aqueous humor cytokine levels in diabetic macular edema. Invest Ophthalmol Vis Sci. 2019;60:1336–1343. https://doi.org/10.1167/iovs.18-26215 PURPOSE. To determine whether baseline cytokine aqueous humor (AH) levels are associated with diabetic macular edema (DME) anatomic response to dexamethasone intravitreal implant (DEX) injection.
Nonverbal Estimation during Numerosity Judgements by Adult Humans

On an automated task, humans selected the larger of two sets of items, each created through the one-by-one addition of items. Participants repeated the alphabet out loud during trials so that they could not count the items. This manipulation disrupted counting without producing major effects on other cognitive capacities such as memory or attention, and performance of this experimental group was poorer than that of participants who counted the items. In Experiment 2, the size of individual items was varied, and performance remained stable when the larger numerical set contained a smaller total amount than the smaller numerical set (i.e., participants used numerical rather than nonnumerical quantity cues in making judgements). In Experiment 3, reports of the number of items in a single set showed scalar variability as accuracy decreased, and variability in responses increased with increases in true set size. These data indicate a mechanism for the approximate representation of numerosity in adult humans that might be shared with nonhuman animals.
Naïve CD 4 + T cells and Recent Thymic Emigrants in Common Variable

1Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2Research Center for Immunodefi ciencies, Pediatrics Center of Excellence, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran 3Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran 4Department of Epidemiology, Pasteur Institute of Iran, Tehran, Iran
Use of pluripotent stem cells for reproductive medicine: are we there yet?

In recent years, pluripotent stem cells have demonstrated to be exciting tools to understand embryonic development, cell lineage specification, tissue generation and repair, and various other biological processes. In addition, the identification and isolation of germ line stem cells has given more insight into germ cell biology at the molecular level and into the underlying causes of infertility which was not possible earlier. The recent derivation of in vitro derived sperm and oocytes from pluripotent stem cells in the mouse model represents a major breakthrough in the field and substantiates the critical relevance of stem cells as a potential alternative resource for treating infertility. Although the past years have yielded compelling information in understanding germ cell development via in vitro stem cell assays, extended investigative research is necessary in order to derive fully functional ‘artificial gametes’ in a safe way for future therapeutic applications.
ROS‐Induced Nuclear Translocation of Calpain‐2 Facilitates Cardiomyocyte Apoptosis in Tail‐Suspended Rats

Isoproterenol (ISO) induced nuclear translocation of calpain‐2 which further increased susceptibility of cardiomyocyte apoptosis in tail‐suspended rats. The underlying mechanisms remain elusive. In the present study, the results showed that ISO (10 nM) significantly elevated NADPH oxidases (NOXs) activity and NOXs‐derived ROS productions which induced nuclear translocation of calpain‐2 in cardiomyocytes of tail‐suspended rats. In contrast, the inhibition of NADPH oxidase or cleavage of ROS not only reduced ROS productions, but also resisted nuclear translocation of calpain‐2 and decreased ISO‐induced apoptosis of cardiomyocyte in tail‐suspended rats. ISO also increased the constitutive binding between calpain‐2 and Ca2+/calmodulin‐dependent protein kinase II δB (CaMK II δB) in nuclei, concomitant with the promotion of CaMK II δB degradation and subsequent down‐regulation of Bcl‐2 mRNA expression and the ratio of Bcl‐2 to Bax protein in tail‐suspended rat cardiomyocytes. These effects of ISO on cardiomyocytes were abolished by a calpain inhibitor PD150606. Inhibition of calpain significantly reduced ISO‐induced loss of the mitochondrial membrane potential, cytochrome c release into the cytoplasm, as well as the activation of caspase‐3 and caspase‐9 in mitochondrial apoptotic pathway. In summary, the above results suggest that ISO increased NOXs‐derived ROS which activated nuclear translocation of calpain‐2, subsequently nuclear calpain‐2 degraded CaMK II δB which reduced the ratio of Bcl‐2 to Bax, and finally the mitochondria apoptosis pathway was triggered in tail‐suspended rat cardiomyocytes. Therefore, calpain‐2 may represent a potentially therapeutic target for prevention of oxidative stress‐associated cardiomyocyte apoptosis. J. Cell. Biochem. 116: 2258–2269, 2015. © 2015 Wiley Periodicals, Inc.
DAS3H: Modeling Student Learning and Forgetting for Optimally Scheduling Distributed Practice of Skills

Spaced repetition is among the most studied learning strategies in the cognitive science literature. It consists in temporally distributing exposure to an information so as to improve long-term memorization. Providing students with an adaptive and personalized distributed practice schedule would benefit more than just a generic scheduler. However, the applicability of such adaptive schedulers seems to be limited to pure memorization, e.g. flashcards or foreign language learning. In this article, we first frame the research problem of optimizing an adaptive and personalized spaced repetition scheduler when memorization concerns the application of underlying multiple skills. To this end, we choose to rely on a student model for inferring knowledge state and memory dynamics on any skill or combination of skills. We argue that no knowledge tracing model takes both memory decay and multiple skill tagging into account for predicting student performance. As a consequence, we propose a new student learning and forgetting model suited to our research problem: DAS3H builds on the additive factor models and includes a representation of the temporal distribution of past practice on the skills involved by an item. In particular, DAS3H allows the learning and forgetting curves to differ from one skill to another. Finally, we provide empirical evidence on three real-world educational datasets that DAS3H outperforms other state-of-the-art EDM models. These results suggest that incorporating both item-skill relationships and forgetting effect improves over student models that consider one or the other.
Vision-based Robotic Grasping from Object Localization, Pose Estimation, Grasp Detection to Motion Planning: A Review

This paper presents a comprehensive survey on vision-based robotic grasping. We concluded four key tasks during robotic grasping, which are object localization, pose estimation, grasp detection and motion planning. In detail, object localization includes object detection and segmentation methods, pose estimation includes RGB-based and RGB-D-based methods, grasp detection includes traditional methods and deep learning-based methods, motion planning includes analytical methods, imitating learning methods, and reinforcement learning methods. Besides, lots of methods accomplish some of the tasks jointly, such as object-detection-combined 6D pose estimation, grasp detection without pose estimation, end-to-end grasp detection, and end-to-end motion planning. These methods are reviewed elaborately in this survey. What's more, related datasets are summarized and comparisons between state-of-the-art methods are given for each task. Challenges about robotic grasping are presented, and future directions in addressing these challenges are also pointed out.
A Search for High-energy Counterparts to Fast Radio Bursts

We report on a search for high-energy counterparts to fast radio bursts (FRBs) with the Fermi Gamma-ray Burst Monitor, Fermi Large Area Telescope, and the Neil Gehrels Swift Observatory Burst Alert Telescope. We find no significant associations for any of the 23 FRBs in our sample, but report upper limits to the high-energy fluence for each on timescales of 0.1, 1, 10, and 100 s. We report lower limits on the ratio of the radio to high-energy fluence, fr/fγ, for timescales of 0.1 and 100 s. We discuss the implications of our non-detections on various proposed progenitor models for FRBs, including analogs of giant pulses from the Crab pulsar and hyperflares from magnetars. This work demonstrates the utility of analyses of high-energy data for FRBs in tracking down the nature of these elusive sources.
Exposure to temporary employment and job insecurity: a longitudinal study of the health effects

Objective This study analysed interactions between job insecurity and temporary employment and health. We tested the violation hypothesis (whether permanent employment increases the health risk associated with job insecurity) and the intensification hypothesis (whether temporary employment increases the health risk associated with job insecurity) in a longitudinal setting. Previous research on this topic is scarce and based on cross-sectional data. Methods A population cohort (n=1071) was surveyed at age 30 and age 42. Exposure to temporary employment during this 12-year period was elicited with a job-time matrix and measured as the score of 6-month periods. Exposure to job insecurity was measured according to the perceived threat of unemployment. Health at follow-up was assessed as optimal versus suboptimal self-rated health, sleep quality and mental health. In addition to sociodemographics and baseline health, the analyses were adjusted for exposure to unemployment, non-employment and self-employment during the 12-year period. Results 26% of participants had been exposed to temporary employment. The effect of job insecurity on health was the same in the exposed and unexposed groups, that is the violation hypothesis was not supported. Non-significant interactions between the exposures and all health outcomes also indicated null findings regarding the intensification hypothesis. Conclusions These findings suggest that perceived job insecurity can lead to adverse health effects in both permanent and temporary employees. Policies should aim to improve work-related well-being by reducing job insecurity. Efforts towards ‘flexicurity’ are important, but it is equally important to remember that a significant proportion of employees with a permanent contract experience job insecurity.
A low-complexity WMMSE algorithm for power allocation in multicarrier NOMA-FD systems

In this paper, we study the power and channel allocation problem for multicarrier non-orthogonal multiple access (NOMA) full duplex (FD) systems. Owing to the presence of multiple interfering users transmitting over the same channel, the considered allocation problem is nonconvex. With the aim of designing a limited complexity solution, we propose an algorithm based on the minimization of the weighted mean square error, which achieves performance reasonably close to the optimum and allows to clearly outperform a conventional orthogonal multiple access approach. Numerical results assess the effectiveness of our proposal.
Extension of the HCOOH and CO2 solid-state reaction network during the CO freeze-out stage: inclusion of H2CO

Context. Formic acid (HCOOH) and carbon dioxide (CO2) are simple species that have been detected in the interstellar medium. The solid-state formation pathways of these species under experimental conditions relevant to prestellar cores are primarily based off of weak infrared transitions of the HOCO complex and usually pertain to the H2O-rich ice phase, and therefore more experimental data are desired. Aims. Here, we present a new and additional solid-state reaction pathway that can form HCOOH and CO2 ice at 10 K “non-energetically” in the laboratory under conditions related to the “heavy” CO freeze-out stage in dense interstellar clouds, i.e., by the hydrogenation of an H2CO:O2 ice mixture. This pathway is used to piece together the HCOOH and CO2 formation routes when H2CO or CO reacts with H and OH radicals. Methods. Temperature programmed desorption – quadrupole mass spectrometry (TPD-QMS) is used to confirm the formation and pathways of newly synthesized ice species as well as to provide information on relative molecular abundances. Reflection absorption infrared spectroscopy (RAIRS) is additionally employed to characterize reaction products and determine relative molecular abundances. Results. We find that for the conditions investigated in conjunction with theoretical results from the literature, H + HOCO and HCO + OH lead to the formation of HCOOH ice in our experiments. Which reaction is more dominant can be determined if the H + HOCO branching ratio is more constrained by computational simulations, as the HCOOH:CO2 abundance ratio is experimentally measured to be around 1.8:1. H + HOCO is more likely than OH + CO (without HOCO formation) to form CO2. Isotope experiments presented here further validate that H + HOCO is the dominant route for HCOOH ice formation in a CO-rich CO:O2 ice mixture that is hydrogenated. These data will help in the search and positive identification of HCOOH ice in prestellar cores.
Analysis of the low-temperature phase in the two-dimensional long-range diluted XY model

The critical behaviour of statistical models with long-range interactions exhibits distinct regimes as a function of $\rho$, the power of the interaction strength decay. For $\rho$ large enough, $\rho>\rho_{\rm sr}$, the critical behaviour is observed to coincide with that of the short-range model. However, there are controversial aspects regarding this picture, one of which is the value of the short-range threshold $\rho_{\rm sr}$ in the case of the long-range XY model in two dimensions. We study the 2d XY model on the {\it diluted} graph, a sparse graph obtained from the 2d lattice by rewiring links with probability decaying with the Euclidean distance of the lattice as $|r|^{-\rho}$, which is expected to feature the same critical behavior of the long range model. Through Monte Carlo sampling and finite-size analysis of the spontaneous magnetisation and of the Binder cumulant, we present numerical evidence that $\rho_{\rm sr}=4$. According to such a result, one expects the model to belong to the Berezinskii-Kosterlitz-Thouless (BKT) universality class for $\rho\ge 4$, and to present a $2^{nd}$-order transition for $\rho<4$.
Strong gravitational lensing by wormholes

We study strong gravitational lensing by a class of static wormhole geometries. Analytical approaches to the same are developed, and the results differ substantially from strong lensing by black holes, first reported by Bozza. We consider two distinct situations, one in which the observer and the source are on the same side of the wormhole throat, and the other in which they are on opposite sides. Distinctive features in our study arise from the fact that photon and antiphoton spheres might be present on both sides of the wormhole throat, and that the throat might itself act as a photon sphere. We show that strong gravitational lensing thus opens up a rich variety of possibilities of relativistic image formation, some of which are novel, and are qualitatively distinct from black hole lensing. These can serve as clear indicators of exotic wormhole geometries.
Quest for the tertiary component in Cyg OB2 #5

Aims. The Cyg OB2 #5 system is thought to consist of a short-period (6.6 d) eclipsing massive binary orbited by an OB-star with a period of ~6.7 yr; these stars in turn are orbited by a distant early B-star with a period of thousands of years. However, while the inner binary has been studied many times, information is missing on the other stars, in particular the third star whose presence was indirectly postulated from recurrent modulations in the radio domain. Besides, to this date, the X-ray light curve could not be fully interpreted, for example in the framework of colliding-wind emission linked to one of the systems. Methods. We obtained new optical and X-ray observations of Cyg OB2 #5, which we combined to archival data. We performed a thorough and homogeneous investigation of all available data, notably revisiting the times of primary minimum in photometry. Results. In the X-ray domain, XMM-Newton provides scattered exposures over ~5000 d whilst Swift provides a nearly continuous monitoring for the last couple of years. Although the X-ray light curve reveals clear variability, no significant period can be found hence the high-energy emission cannot be explained solely in terms of colliding winds varying along either the short or intermediate orbits. The optical data reveal for the first time clear signs of reflex motion. The photometry indicates the presence of a 2366 d (i.e. 6.5 yr) period while the associated radial velocity changes are detected at the 3σ level in the systemic velocity of the He II λ 4686 emission line. With the revised period, the radio light curve is interpreted consistently in terms of a wind interaction between the inner binary and the tertiary star. From these optical and radio data, we derive constraints on the physical properties of the tertiary star and its orbit.
ReshapeGAN: Object Reshaping by Providing A Single Reference Image

The aim of this work is learning to reshape the object in an input image to an arbitrary new shape, by just simply providing a single reference image with an object instance in the desired shape. We propose a new Generative Adversarial Network (GAN) architecture for such an object reshaping problem, named ReshapeGAN. The network can be tailored for handling all kinds of problem settings, including both within-domain (or single-dataset) reshaping and cross-domain (typically across mutiple datasets) reshaping, with paired or unpaired training data. The appearance of the input object is preserved in all cases, and thus it is still identifiable after reshaping, which has never been achieved as far as we are aware. We present the tailored models of the proposed ReshapeGAN for all the problem settings, and have them tested on 8 kinds of reshaping tasks with 13 different datasets, demonstrating the ability of ReshapeGAN on generating convincing and superior results for object reshaping. To the best of our knowledge, we are the first to be able to make one GAN framework work on all such object reshaping tasks, especially the cross-domain tasks on handling multiple diverse datasets. We present here both ablation studies on our proposed ReshapeGAN models and comparisons with the state-of-the-art models when they are made comparable, using all kinds of applicable metrics that we are aware of.
Dualizable link homology

We modify our previous construction of link homology in order to include a natural duality functor $\mathfrak{F}$. To a link $L$ we associate a triply-graded module $HXY(L)$ over the graded polynomial ring $R(L)=\mathbb{C}[x_1,y_1,\dots,x_\ell,y_\ell]$. The module has an involution $\mathfrak{F}$ that intertwines the Fourier transform on $R(L)$, $\mathfrak{F}(x_i)=y_i$, $\mathfrak{F}(y_i)=x_i$. In the case when $\ell=1$ the module is free over $R(L)$ and specialization to $x=y=0$ matches with the triply-graded knot homology previously constructed by the authors. Thus we show that the corresponding super-polynomial satisfies the categorical version of $q\to 1/q$ symmetry. We also construct an isotopy invariant of the closure of a dichromatic braid and relate this invariant to $HXY(L)$.
Thickness-dependent electron momentum relaxation times in iron films

Terahertz time-domain conductivity measurements in 2 to 100 nm thick iron films resolve the femtosecond time delay between applied electric fields and resulting currents. This current response time decreases from 29 fs for thickest films to 7 fs for the thinnest films. The macroscopic response time is not strictly proportional to the conductivity. This excludes the existence of a single relaxation time universal for all conduction electrons. We must assume a distribution of microscopic momentum relaxation times. The macroscopic response time depends on average and variation of this distribution; the observed deviation between response time and conductivity scaling corresponds to the scaling of the variation. The variation of microscopic relaxation times depends on film thickness because electrons with different relaxation times are affected differently by the confinement since they have different mean free paths.