Miracle-dz/UniFAR-FTUs huggingface dataset:
High nest predation by brown tree snakes on Guam

A great deal of attention has recently been focused on the drastic decline of the native avifauna of Guam since the 1960s (Engbring 1983; Jenkins 1983; Engbring and Ramsey 1984; Savidge 1984, 1986, 1987). Populations of once common native forest birds have declined and are now thought to be locally extinct or restricted to the northernmost part of the island (Jenkins 1983; Engbring and Ramsey 1984; U.S. Fish and Wildlife Service, in press). Savidge (1986, 1987) investigated the role of disease and predation in the decline and concluded that the introduced brown tree snake (Boiga irregularis) was responsible for the extinction or decline of 10 species of native forest birds on Guam. My report provides direct evidence of the significant impact that snake predation is having on the nesting success and population dynamics of the Philippine TurtleDove (Streptopelia bitorquata), one of the few wild birds on Guam that remains sufficiently abundant for such a study. The Philippine Turtle-Dove was probably introduced to the Mariana Islands by the Spanish in the late 1700s (Baker 1951). The species became one of the most abundant birds on Guam and was made a legal game bird (Baker 1947, 1951; Conry 1987). More recently, however, numbers have declined in a pattern similar to that of the native forest birds, though not as severely, and the hunting season for the species has been closed (Engbring and Ramsey 1984, Conry 1987). The turtle-dove is presently uncommon to rare throughout southern Guam, common in localized areas of central and northern Guam, and abundant on Cocos Island, a small snake-free islet 2 km off southern Guam (Conry 1987). The turtle-dove also occurs on the neighboring southern Mariana Islands of Rota, Aguijan, Tinian, and Saipan (Pratt et al. 1987), where its numbers appear stable (T. K. Pratt, pers. comm.) and the brown tree snake does not occur.
Modeling COVID-19 spread in small colleges

We develop an agent-based model on a network meant to capture features unique to COVID-19 spread through a small residential college. We find that a safe reopening requires strong policy from administrators combined with cautious behavior from students. Strong policy includes weekly screening tests with quick turnaround and halving the campus population. Cautious behavior from students means wearing facemasks, socializing less, and showing up for COVID-19 testing. We also find that comprehensive testing and facemasks are the most effective single interventions, building closures can lead to infection spikes in other areas depending on student behavior, and faster return of test results significantly reduces total infections.
Phase-resolved Analyses of Millihertz Quasi-periodic Oscillations in 4U 1636-53 using the Hilbert–Huang Transform

We present phase-resolved spectroscopy based on the Hilbert–Huang transform (HHT) for millihertz quasi-periodic oscillations (mHz QPOs) in 4U 1636-53. The ∼8 mHz QPO can be detected approximately several thousand seconds before a type-I X-ray burst. It has been interpreted as marginally stable burning on the neutron-star surface. In this study, we use the HHT to analyze the data collected by XMM-Newton between 2007 and 2009. The HHT is a powerful tool that enables us to obtain instantaneous frequency, amplitude, and phase of phenomena with nonstationary periodicity, such as QPOs. With well-defined phases, the oscillation profile of the ∼8 mHz QPO for 4U 1636-53 can be precisely revealed. In addition to the oscillation profile, phase-resolved spectra for the complete cycle are constructed. From the correlation between spectral parameters and fluxes, we find that the oscillation is mainly attributed to variations in the area emitting blackbody radiation in three out of four observations with mHz QPO detections, whereas the other one shows a concurrent variation of temperature and flux with a constant emitting area. Although the cause of the difference is not clear, it might be related to the spectral state of the source that can be observed from a hard color difference in the color–color diagram.
Align Deep Features for Oriented Object Detection

The past decade has witnessed significant progress on detecting objects in aerial images that are often distributed with large-scale variations and arbitrary orientations. However, most of existing methods rely on heuristically defined anchors with different scales, angles, and aspect ratios, and usually suffer from severe misalignment between anchor boxes (ABs) and axis-aligned convolutional features, which lead to the common inconsistency between the classification score and localization accuracy. To address this issue, we propose a single-shot alignment network (S2A-Net) consisting of two modules: a feature alignment module (FAM) and an oriented detection module (ODM). The FAM can generate high-quality anchors with an anchor refinement network and adaptively align the convolutional features according to the ABs with a novel alignment convolution. The ODM first adopts active rotating filters to encode the orientation information and then produces orientation-sensitive and orientation-invariant features to alleviate the inconsistency between classification score and localization accuracy. Besides, we further explore the approach to detect objects in large-size images, which leads to a better trade-off between speed and accuracy. Extensive experiments demonstrate that our method can achieve the state-of-the-art performance on two commonly used aerial objects’ data sets (i.e., DOTA and HRSC2016) while keeping high efficiency.
Acyclic, Star and Injective Colouring: A Complexity Picture for H-Free Graphs

A k-colouring c of a graph G is a mapping V(G) to {1,2,. k} such that c(u) is distinct from c(v) whenever u and v are adjacent. The corresponding decision problem is Colouring. A colouring is acyclic, star, or injective if any two colour classes induce a forest, star forest or disjoint union of vertices and edges, respectively. Hence, every injective colouring is a star colouring and every star colouring is an acyclic colouring. The corresponding decision problems are Acyclic Colouring, Star Colouring and Injective Colouring (the last problem is also known as L(1,1)-Labelling). A classical complexity result on Colouring is a well-known dichotomy for H-free graphs, which was established twenty years ago (in this context, a graph is H-free if and only if it does not contain H as an induced subgraph). Moreover, this result has led to a large collection of results, which helped us to better understand the complexity of Colouring. In contrast, there is no systematic study into the computational complexity of the other three problems despite numerous algorithmic and structural results that have appeared over the years. We initiate such a systematic complexity study, and similar to the study of Colouring we use the class of H-free graphs as a testbed. We prove: 1. We give almost complete classifications for the computational complexity of Acyclic Colouring, Star Colouring and Injective Colouring for H-free graphs. 2. If the number of colours k is fixed, that is, not part of the input, we give full complexity classifications for each of the three problems for H-free graphs. From our study we conclude that for fixed k the three problems behave in the same way, but this is no longer true if k is part of the input. To obtain several of our results we prove stronger complexity results that in particular involve the girth of a graph and the class of line graphs.
Diameter‐free estimates for the quadratic Vinogradov mean value theorem

Let s⩾3$s \geqslant 3$ be a natural number, let ψ(x)$\psi (x)$ be a polynomial with real coefficients and degree d⩾2$d \geqslant 2$ , and let A$A$ be some large, non‐empty, finite subset of real numbers. We use Es,2(A)$E_{s,2}(A)$ to denote the number of solutions to the system of equations ∑i=1s(ψ(xi)−ψ(xi+s))=∑i=1s(xi−xi+s)=0,$$\begin{equation*}\hskip2.5pc \sum _{i=1}^{s} (\psi (x_i) - \psi (x_{i+s}) )= \sum _{i=1}^{s} (x_i - x_{i+s} ) = 0, \end{equation*}$$where xi∈A$x_i \in A$ for each 1⩽i⩽2s$1 \leqslant i \leqslant 2s$ . Our main result shows that Es,2(A)≪d,s|A|2s−3+ηs,$$\begin{equation*}\hskip6pc E_{s,2}(A) \ll _{d,s} |A|^{2s -3 + \eta _{s}}, \end{equation*}$$where η3=1/2$\eta _3 = 1/2$ , and ηs=(1/4−1/7246)·2−s+4$\eta _{s} = (1/4- 1/7246)\cdot 2^{-s + 4}$ when s⩾4$s \geqslant 4$ . The only other previously known result of this flavour is due to Bourgain and Demeter, who showed that when ψ(x)=x2$\psi (x) = x^2$ and s=3$s=3$ , we have E3,2(A)≪ε|A|3+1/2+ε,$$\begin{equation*}\hskip6pc E_{3,2}(A) \ll _{\epsilon } |A|^{3 + 1/2 + \epsilon }, \end{equation*}$$for each ε>0$\epsilon > 0$ . Thus, our main result improves upon the above estimate, while also generalising it for larger values of s$s$ and more wide‐ranging choices of ψ(x)$\psi (x)$ . The novelty of our estimates is that they only depend on d$d$ , s$s$ and |A|$|A|$ , and are independent of the diameter of A$A$ . Thus, when A$A$ is a sparse set, our results are stronger than the corresponding bounds that are provided by methods such as decoupling and efficient congruencing. Consequently, our strategy differs from these two lines of approach, and we employ techniques from incidence geometry, arithmetic combinatorics and analytic number theory. Amongst other applications, our estimates lead to stronger discrete restriction estimates for sparse sequences.
The Effect of Solar Wind Expansion and Nonequilibrium Ionization on the Broadening of Coronal Emission Lines

When observing spectral lines in the optically thin corona, line-of-sight (LOS) effects can strongly affect the interpretation of the data, especially in regions just above the limb. We present a semiempirical forward model, called the Global Heliospheric Optically thin Spectral Transport Simulation (GHOSTS), to characterize these effects. GHOSTS uses inputs from several other models to compute nonequilibrium ionization states (which include the solar-wind freezing-in effect) for many ions. These are used to generate ensembles of simulated spectral lines that are examined in detail, with emphasis on (1) relationships between quantities derived from observables and the radial variation of the observed quantities, (2) the behavior of thermal and nonthermal components of the line width, and (3) relative contributions of collisionally excited and radiatively scattered photons. We find that rapidly changing temperatures in the low corona can cause ion populations to vary dramatically with height. This can lead to line width measurements that are constant with height (a “plateau” effect) even when the temperature is increasing rapidly, as the plane of sky becomes evacuated and the foreground/background plasma dominates the observation. We find that LOS effects often drive the velocity width to be close to the plane-of-sky value of the wind speed, despite it flowing perpendicularly to the LOS there. The plateau effect can also cause the nonthermal component of the line width to greatly exceed the solar wind velocity at the observation height. Lastly, we study how much of the LOS is significant to the observation, and the importance of including continuum in the solar spectrum when computing the radiatively scattered emission.
The Wide-field VLBA Calibrator Survey: WFCS

This paper presents the results of the largest very long baseline interferometry (VLBI) absolute astrometry campaign to date of 13,645 radio source observations with the Very Long Baseline Array. Of these, 7220 have been detected, including 6755 target sources that have never been observed with VLBI before. This makes the present VLBI catalog the largest ever published. The positions of the target sources have been determined with the median uncertainty of 1.7 mas, and 15,542 images of 7171 sources have been generated. Unlike previous absolute radio astrometry campaigns, observations were made at 4.3 and 7.6 GHz simultaneously using a single wide-band receiver. Because of the fine spectral and time resolutions, the field of view was 4′–8′—much greater than the 10″–20″ in previous surveys. This made possible the use of input catalogs with low position accuracy and the detection of a compact component in extended sources. Unlike previous absolute astrometry campaigns, both steep- and flat-spectrum sources were observed. The observations were scheduled in the so-called filler mode to fill the gaps between other high-priority programs. This was achieved by the development of the totally automatic scheduling procedure.
Combining 
T1
 and 
T2
 estimation with randomized benchmarking and bounding the diamond distance

The characterization of errors in a quantum system is a fundamental step for two important goals. First, learning about specific sources of error is essential for optimizing experimental design and error correction methods. Second, verifying that the error is below some threshold value is required to meet the criteria of threshold theorems. We consider the case where errors are dominated by the generalized damping channel (encompassing the common intrinsic processes of amplitude damping and dephasing) but may also contain additional unknown error sources. We demonstrate the robustness of standard $T_1$ and $T_2$ estimation methods and provide expressions for the expected error in these estimates under the additional error sources. We then derive expressions that allow a comparison of the actual and expected results of fine-grained randomized benchmarking experiments based on the damping parameters. Given the results of this comparison, we provide bounds that allow robust estimation of the thresholds for fault-tolerance.
TAnoGAN: Time Series Anomaly Detection with Generative Adversarial Networks

Anomaly detection in time series data is a significant problem faced in many application areas such as manufacturing, medical imaging and cyber-security. Recently, Generative Adversarial Networks (GAN) have gained attention for generation and anomaly detection in image domain. In this paper, we propose a novel GAN-based unsupervised method called TAnoGan for detecting anomalies in time series when a small number of data points are available. We evaluate TAnoGan with 46 real-world time series datasets that cover a variety of domains. Extensive experimental results show that TAnoGan performs better than traditional and neural network models.
Lelong numbers of currents of full mass intersection

We study Lelong numbers of currents of full mass intersection on a compact Kaehler manifold in a mixed setting. Our main theorems cover some recent results due to Darvas-Di Nezza-Lu. One of the key ingredients in our approach is a new notion of products of pseudoeffective classes which captures some "pluripolar part" of the "total intersection" of given pseudoeffective classes.
Local Energy Solutions to the Navier-Stokes Equations in Wiener Amalgam Spaces

We establish existence of solutions in a scale of classes weaker than the finite energy Leray class and stronger than the infinite energy Lemari\'e-Rieusset class. The new classes are based on the $L^2$ Wiener amalgam spaces. Solutions in the classes closer to the Leray class are shown to satisfy some properties known in the Leray class but not the Lemari\'e-Rieusset class, namely eventual regularity and long time estimates on the growth of the local energy. In this sense, these solutions bridge the gap between Leray's original solutions and Lemari\'e-Rieusset's solutions and help identify scalings at which certain properties may break down.
Cryoprotective Mechanism of Saccharides on Freeze-Drying of Liposome

The cryoprotective effects of various additives such as saccharides and polyalcohols on sonicated liposomes during freeze-drying were investigated. Fusion of liposomes was measured as energy transfer and size distribution. There was considerable difference among the additives in their cryoprotective ability. Polyalcohol systems showed considerable fusion. Although monosaccharides completely prevented the fusion of liposomes during freeze-drying similarly to disaccharides, they showed far less ability to retain the entrapped calcein of liposomes than disaccharides. The heating thermograms of differential scanning calorimetry of dipalmitoylphosphatidylcholine (DPPC) in the state of sonicated liposomes freeze-dried with various additives were measured. Disaccharides and monosaccharides again markedly differed in their effects on the thermal property of the DPPC. The reason for the variety in their cryoprotective ability was attributed to the difference in the strength of their interaction with phospholipid head group.
Greedy Approaches to Online Stochastic Matching

Within the context of stochastic probing with commitment, we consider the online stochastic matching problem; that is, the one-sided online bipartite matching problem where edges adjacent to an online node must be probed to determine if they exist based on edge probabilities that become known when an online vertex arrives. If a probed edge exists, it must be used in the matching (if possible). We consider the competitiveness of online algorithms in the random order input model (ROM), when the offline vertices are weighted. More specifically, we consider a bipartite stochastic graph $G = (U,V,E)$ where $U$ is the set of offline vertices, $V$ is the set of online vertices and $G$ has edge probabilities $(p_{e})_{e \in E}$ and vertex weights $(w_{u})_{u \in U}$. Additionally, $G$ has patience values $(\ell_{v})_{v \in V}$, where $\ell_v$ indicates the maximum number of edges adjacent to an online vertex $v$ which can be probed. We assume that $U$ and $(w_{u})_{u \in U}$ are known in advance, and that the patience, adjacent edges and edge probabilities for each online vertex are only revealed when the online vertex arrives. If any one of the following three conditions is satisfied, then there is a conceptually simple deterministic greedy algorithm whose competitive ratio is $1-\frac{1}{e}$. (1) When the offline vertices are unweighted. $\\$ (2) When the online vertex probabilities are "vertex uniform"; i.e., $p_{u,v} = p_v$ for all $(u,v) \in E$. $\\$ (3) When the patience constraint $\ell_v$ satisfies $\ell_v \in \{[1,|U|\}$ for every online vertex; i.e., every online vertex either has unit or full patience. Setting the probability $p_e = 1$ for all $e \in E$, the stochastic problem becomes the classical online bipartite matching problem. Our competitive ratios thus generalize corresponding results for the classical ROM bipartite matching setting.
Measuring the Stellar Population Parameters of the Early-type Galaxy NGC 3923: The Challenging Measurement of the Initial Mass Function

Recent studies of early-type galaxies have suggested that the initial mass function (IMF) slope is bottom-heavy; that is, they contain a larger fraction of low-mass stars than the Milky Way. However, measurements of the IMF remain challenging in unresolved galaxies because features in their observed spectra are sensitive to a number of factors, including the stellar age, metallicity, and elemental abundances, in addition to the IMF. In this paper, we use new high signal-to-noise IMACS (Magellan) spectra to study the elliptical shell galaxy NGC 3923 at optical (3700–6600 Å) and near-infrared (7900–8500 Å) wavelengths, as a function of radius. We have undertaken a number of independent approaches to better understand the uncertainties in our results. (1) We compare two different stellar population model libraries; (2) we undertake spectral index fitting as well as full spectral fitting; (3) we have performed simulations for which we a priori know the input IMF and that closely match our data; (4) we also investigate the effects of including a two-component rather than a single stellar population. We show that our results are sensitive to the assumptions we make and to the methods we use. In addition, we evaluate the accuracy and precision of our results based on simulated mock data. We find some indication (although assumption dependent) for a bottom-heavy IMF in the mass range 0.5–1.0 M ⊙, while the IMF in the mass range 0.08–0.5 M ⊙ appears to be Milky Way–like and constant. Including near-infrared data in our analysis gives consistent results and improves the precision.
Adapting Event Extractors to Medical Data: Bridging the Covariate Shift

We tackle the task of adapting event extractors to new domains without labeled data, by aligning the marginal distributions of source and target domains. As a testbed, we create two new event extraction datasets using English texts from two medical domains: (i) clinical notes, and (ii) doctor-patient conversations. We test the efficacy of three marginal alignment techniques: (i) adversarial domain adaptation (ADA), (ii) domain adaptive fine-tuning (DAFT), and (iii) a new instance weighting technique based on language model likelihood scores (LIW). LIW and DAFT improve over a no-transfer BERT baseline on both domains, but ADA only improves on notes. Deeper analysis of performance under different types of shifts (e.g., lexical shift, semantic shift) explains some of the variations among models. Our best-performing models reach F1 scores of 70.0 and 72.9 on notes and conversations respectively, using no labeled target data.
Sharp $L^p$-$L^q$ estimate fof the spectral projection associated with the twisted Laplacian

In this note we are concerned with estimates for the spectral projection operator $\mathcal{P}_\mu$ associated with the twisted Laplacian $L$. We completely characterize the optimal bounds on the operator norm of $\mathcal{P}_\mu$ from $L^p$ to $L^q$ when $1\le p\le 2\le q\le \infty$. As an application, we obtain uniform resolvent estimate for $L$.
Top2Vec: Distributed Representations of Topics

Topic modeling is used for discovering latent semantic structure, usually referred to as topics, in a large collection of documents. The most widely used methods are Latent Dirichlet Allocation and Probabilistic Latent Semantic Analysis. Despite their popularity they have several weaknesses. In order to achieve optimal results they often require the number of topics to be known, custom stop-word lists, stemming, and lemmatization. Additionally these methods rely on bag-of-words representation of documents which ignore the ordering and semantics of words. Distributed representations of documents and words have gained popularity due to their ability to capture semantics of words and documents. We present $\texttt{top2vec}$, which leverages joint document and word semantic embedding to find $\textit{topic vectors}$. This model does not require stop-word lists, stemming or lemmatization, and it automatically finds the number of topics. The resulting topic vectors are jointly embedded with the document and word vectors with distance between them representing semantic similarity. Our experiments demonstrate that $\texttt{top2vec}$ finds topics which are significantly more informative and representative of the corpus trained on than probabilistic generative models.
Logic-Induced Bisimulations

We define a new logic-induced notion of bisimulation (called $\rho$-bisimulation) for coalgebraic modal logics given by a logical connection, and investigate its properties. We show that it is structural in the sense that it is defined only in terms of the coalgebra structure and the one-step modal semantics and, moreover, can be characterised by a form of relation lifting. Furthermore we compare $\rho$-bisimulations to several well-known equivalence notions, and we prove that the collection of bisimulations between two models often forms a complete lattice. The main technical result is a Hennessy-Milner type theorem which states that, under certain conditions, logical equivalence implies $\rho$-bisimilarity. In particular, the latter does \emph{not} rely on a duality between functors $\mathsf{T}$ (the type of the coalgebras) and $\mathsf{L}$ (which gives the logic), nor on properties of the logical connection $\rho$.