Miracle-dz/UniFAR-FTUs huggingface dataset:
Metrology of Time-Domain Soft X-Ray Attosecond Pulses and Reevaluation of Pulse Durations of Three Recent Experiments

Attosecond pulses in the soft-X-ray (SXR) to water-window energy region offer the tools for creating and studying target specific localized inner-shell electrons or holes in materials, enable monitoring or controlling charge and energy flows in a dynamic system on attosecond timescales. Recently, a number of laboratories have reported generation of continuum harmonics in the hundred-electron-volt to kilovolt region with few-cycle long-wavelength mid-infrared lasers. These harmonics have the bandwidth to support pulses with duration of few- to few-ten attoseconds. But harmonics generated in a gas medium have attochirps that cannot be fully compensated by materials over a broad spectral range; thus, realistically what are the typical shortest attosecond pulses that one can generate? To answer this question, it is essential that the temporal attosecond pulses be accurately characterized. By re-analyzing the soft X-ray harmonics reported in three recent experiments \cite{chang_natcom2017,Thomas_OE2017,Bieger_2017PRX} using a newly developed broadband phase retrieval algorithm, we show that their generated attosecond pulses are all longer than about 60 as. Since broadband pulses tend to have high-order chirps away from the spectral center of the pulse, the algorithm has to be able to retrieve accurately the phase over the whole bandwidth. Our re-evaluated pulse durations are found to be longer than those previously reported. We also introduce the autocorrelation (AC) of the streaking spectrogram. By comparing the ACs from the experiments and from the retrieved SXR pulses, the accuracy of the retrieved results can be directly visualized to ensure that correct phases have been obtained. Our retrieval method is fast and accurate, and it shall provide a powerful tool for the metrology of few-ten-attosecond pulses in the future.
Household Matters: Revisiting the Returns to Capital Among Female Micro-Entrepreneurs

Multiple field experiments report positive financial returns to capital shocks for male and not female microentrepreneurs. But these analyses overlook the fact that female entrepreneurs often reside with male entrepreneurs. Using data from experiments in India, Sri Lanka, and Ghana, we show that the observed gender gap in microenterprise responses does not reflect lower returns on investment, when measured at the household level. Instead, the absence of a profit response among female-run enterprises reflects the fact that women’s capital is typically invested into their husband’s enterprise. We cannot reject equivalence of household-level income gains for male and female capital shock recipients. (JEL G31, J16, L25, L26, O12, O16)
How degenerate is the parametrization of neural networks with the ReLU activation function?

Neural network training is usually accomplished by solving a non-convex optimization problem using stochastic gradient descent. Although one optimizes over the networks parameters, the main loss function generally only depends on the realization of the neural network, i.e. the function it computes. Studying the optimization problem over the space of realizations opens up new ways to understand neural network training. In particular, usual loss functions like mean squared error and categorical cross entropy are convex on spaces of neural network realizations, which themselves are non-convex. Approximation capabilities of neural networks can be used to deal with the latter non-convexity, which allows us to establish that for sufficiently large networks local minima of a regularized optimization problem on the realization space are almost optimal. Note, however, that each realization has many different, possibly degenerate, parametrizations. In particular, a local minimum in the parametrization space needs not correspond to a local minimum in the realization space. To establish such a connection, inverse stability of the realization map is required, meaning that proximity of realizations must imply proximity of corresponding parametrizations. We present pathologies which prevent inverse stability in general, and, for shallow networks, proceed to establish a restricted space of parametrizations on which we have inverse stability w.r. t. to a Sobolev norm. Furthermore, we show that by optimizing over such restricted sets, it is still possible to learn any function which can be learned by optimization over unrestricted sets.
ALMA Polarimetry of AT2018cow

We present the first radio polarimetric observations of a fast-rising blue optical transient, AT2018cow. Two epochs of polarimetry with additional coincident photometry were performed with the Atacama Large Millimeter/submillimeter Array. The overall photometric results based on simultaneous observations in the 100 and 230 GHz bands are consistent with the nonthermal radiation model reported by Ho et al. and indicate that the spectral peaks (∼110 GHz at the first epoch and ∼67 GHz at the second epoch) represent the synchrotron self-absorption frequency. The non-detection of linear polarization with <0.15% in the 230 GHz band at the phase when the effect of synchrotron self-absorption was quite small in the band may be explained by internal Faraday depolarization with high circumburst density and strong magnetic field. This result supports the stellar explosion scenario rather than the tidal disruption model. The maximum energy of accelerating particles at the shocks of AT2018cow-like objects is also discussed.
Estimating Risk and Uncertainty in Deep Reinforcement Learning

We propose a method for disentangling epistemic and aleatoric uncertainties in deep reinforcement learning. Aleatoric uncertainty, or risk, which arises from inherently stochastic environments or agents, must be accounted for in the design of risk-sensitive algorithms. Epistemic uncertainty, which stems from limited data, is important both for risk-sensitivity and for efficient exploration. Our method combines elements from distributional reinforcement learning and approximate Bayesian inference techniques with neural networks, allowing us to disentangle both types of uncertainty on the expected return of a policy. Specifically, the learned return distribution provides the aleatoric uncertainty, and the Bayesian posterior yields the epistemic uncertainty. Although our approach in principle requires a large number of samples from the Bayesian posterior to estimate the epistemic uncertainty, we show that two networks already yield a useful approximation. We perform experiments that illustrate our method and some applications.
Modeling the X-Ray Power Spectra of AGN by Using Reprocessing Echoes from an Extended Corona

Characteristic signatures that X-ray reverberation from an extended corona can manifest in the observed PSD of AGN are investigated. The presence of two X-ray blobs illuminating an accretion disk can cause the interference between two reprocessing-echo components and produce distinct physical features in the PSD. The oscillatory structures (e.g., dips and humps) are seen, but, contrarily to the lamp-post case, the strongest dip is not always the one at the lowest frequency. Instead, we find that the frequency where the strongest dip is seen is associated with the lower-source height while the lowest frequency where the first dip appears is linked to the upper-source height. This is because the reverberation timescales increase with the source height. Accurate modeling of the PSD then helps put constraints on the lower and upper limits of the corona extent. Furthermore, the reverberation signatures are less pronounced with increasing number of sources that do not produce reflection (e.g., additional X-rays from fast, relativistic outflows). The amplitude of the oscillations also depends on the amount of dilution contributed by the X-ray sources, and thus encodes information about their relative brightness. Due to stronger dilutions, robust detection of these signatures with current observations will become even more difficult if the corona is extended. Future observations made by Athena will enable us to fit these characteristics with statistically significant details, and to reveal the nature of the disk–corona system.
A general class of gravitational theories as alternatives to dark matter where the speed of gravity always equals the speed of light.

A number of theories of gravity have been proposed as proxies for dark matter in the regime of galaxies and cosmology. The recent observations of gravitational waves (GW170817) from the merger of two neutron stars, followed by an electromagnetic counterpart (GW170817a) have placed stringent constraints on the difference of the speed of gravity to the speed of light, severely restricting the phenomenological viability of such theories. We revisit the impact of these observations on the Tensor-Vector-Scalar (TeVeS) paradigm of relativistic Modified Newtonian Dynamics (MOND) and demonstrate the existence of a previously unknown class of this paradigm where the speed of gravity always equals the speed of light. We show that this holds without altering the usual (bimetric) MOND phenomenology in galaxies.
The effect of temperature on the development and reproduction of Busseola fusca (Lepidoptera: Noctuidae)

Abstract The effect of temperature on the reproduction and development of Busseola fusca was studied under laboratory conditions. Single male–female pairs were confined to oviposition chambers kept at 15, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. Data on reproduction parameters were captured daily. Oviposition occurred at all the mentioned temperatures but no fertility was recorded at 30°C. The total number of eggs laid per female moth was between 300 and 400 and the optimum temperature for oviposition and fertility was between 20 and 26°C. Larval development was studied at five different temperature regimes, i.e. 15, 18, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. The most favourable temperature as well as the upper threshold temperature for larval development was between 26 and 30°C. Total development period was 152.6–52.6 days, respectively, at 15°C, and 26–30°C. The thermal constants for B. fusca was 99.50, 536.48, 246.25 and 893.66°D and lower temperature thresholds were 10.36, 8.14, 8.99 and 8.84°C, for completion of the egg, larval, pupal and egg-to-adult stages, respectively. Results on the thermal constants and lower and upper threshold temperatures of B. fusca can be used to predict the impact of climate change on the distribution and population growth of this pest.
Average reward reinforcement learning with unknown mixing times

We derive and analyze learning algorithms for policy evaluation, apprenticeship learning, and policy gradient for average reward criteria. Existing algorithms explicitly require an upper bound on the mixing time. In contrast, we build on ideas from Markov chain theory and derive sampling algorithms that do not require such an upper bound. For these algorithms, we provide theoretical bounds on their sample-complexity and running time.
PoseRBPF: A Rao–Blackwellized Particle Filter for 6-D Object Pose Tracking

Tracking 6-D poses of objects from videos provides rich information to a robot in performing different tasks such as manipulation and navigation. In this article, we formulate the 6-D object pose tracking problem in the Rao–Blackwellized particle filtering framework, where the 3-D rotation and the 3-D translation of an object are decoupled. This factorization allows our approach, called PoseRBPF, to efficiently estimate the 3-D translation of an object along with the full distribution over the 3-D rotation. This is achieved by discretizing the rotation space in a fine-grained manner and training an autoencoder network to construct a codebook of feature embeddings for the discretized rotations. As a result, PoseRBPF can track objects with arbitrary symmetries while still maintaining adequate posterior distributions. Our approach achieves state-of-the-art results on two 6-D pose estimation benchmarks. We open-source our implementation at https://github.com/NVlabs/PoseRBPF.
Erratum: Static charged black holes in (2+1)-dimensional dilaton gravity

A one parameter family of static charged black hole solutions in $(2+1)$-dimensional general relativity minimally coupled to a dilaton $\phi\propto ln({r\over\beta})$ with a potential term $e^{b\phi}\Lambda$ is obtained. Their causal strutures are investigated, and thermodynamical temperature and entropy are computed. One particular black hole in the family has the same thermodynamical properties as the Schwarzschild black hole in $3+1$ dimensions. Solutions with cosmological horizons are also discussed. Finally, a class of black holes arising from the dilaton with a negative kinetic term (tachyon) is briefly discussed.
Through thick or thin: multiple components of the magneto-ionic medium towards the nearby H ii region Sharpless 2–27 revealed by Faraday tomography

Sharpless 2-27 (Sh2-27) is a nearby ${\rm H\,{\small II}}$ region excited by $\zeta$Oph. We present observations of polarized radio emission from 300 to 480$\,$MHz towards Sh2-27, made with the Parkes 64$\,$m Radio Telescope as part of the Global Magneto-Ionic Medium Survey. These observations have an angular resolution of $1.35^{\circ}$, and the data are uniquely sensitive to magneto-ionic structure on large angular scales. We demonstrate that background polarized emission towards Sh2-27 is totally depolarized in our observations, allowing us to investigate the foreground. We analyse the results of Faraday tomography, mapping the magnetised interstellar medium along the 165$\,$pc path to Sh2-27. The Faraday dispersion function in this direction has peaks at three Faraday depths. We consider both Faraday thick and thin models for this observation, finding that the thin model is preferred. We further model this as Faraday rotation of diffuse synchrotron emission in the Local Bubble and in two foreground neutral clouds. The Local Bubble extends for 80$\,$pc in this direction, and we find a Faraday depth of $-0.8 \pm 0.4\,$rad$\,$m$^{-2}$. This indicates a field directed away from the Sun with a strength of $-2.5\pm1.2\,\mu$G. The near and far neutral clouds are each about 30$\,$pc thick, and we find Faraday depths of $-6.6\pm0.6\,$rad$\,$m$^{-2}$ and $+13.7\pm0.8\,$rad$\,$m$^{-2}$, respectively. We estimate that the line-of-sight magnetic strengths in the near and far cloud are $B_{\parallel, \text{near}} \approx -15\,\mu\text{G}$ and $B_{\parallel, \text{far}} \approx +30\,\mu\text{G}$. Our results demonstrate that Faraday tomography can be used to investigate the magneto-ionic properties of foreground features in front of nearby ${\rm H\,{\small II}}$ regions.
The space of persistence diagrams on $n$ points coarsely embeds into Hilbert space

We prove that the space of persistence diagrams on $n$ points (with the bottleneck or a Wasserstein distance) coarsely embeds into Hilbert space by showing it is of asymptotic dimension $2n$. Such an embedding enables utilisation of Hilbert space techniques on the space of persistence diagrams. We also prove that when the number of points is not bounded, the corresponding spaces of persistence diagrams do not have finite asymptotic dimension. Furthermore, in the case of the bottleneck distance, the corresponding space does not coarsely embed into Hilbert space.
End-tidal carbon dioxide during cardiopulmonary resuscitation in humans presenting mostly with asystole: a predictor of outcome.

OBJECTIVE To determine whether continuous semiquantitative assessment of end-tidal CO2 could provide a highly sensitive predictor of return of spontaneous circulation during cardiopulmonary resuscitation (CPR). DESIGN Prospective, clinical study. SETTING Prehospital CPR. PATIENTS One hundred twenty patients, during nontraumatic cardiac arrest. INTERVENTIONS End-tidal CO2 values were measured continuously after tracheal intubation, and were categorized as the initial value, and as minimal and maximal values during the first 20 mins. MEASUREMENTS AND MAIN RESULTS Presenting rhythm was asystole in 22 of the first 24 patients. Return of spontaneous circulation occurred in eight patients. Initial, minimal, and maximal end-tidal CO2 values were significantly (p < .01) higher in these patients than in the patients without return of spontaneous circulation. Cutoff values providing a 100% sensitivity and the highest specificity in predicting return of spontaneous circulation were found to be 10 torr for initial and maximal end-tidal CO2 values, and 2 torr for the minimal end-tidal CO2 value. The number of patients required to reject (with a risk error of <.05) the hypothesis of an actual sensitivity of < or = 90% for an observed sensitivity of 100% was found to be 95. In the second part of the study, this hypothesis was prospectively tested for initial and maximal end-tidal CO2 values in the subsequent 96 patients. Presenting cardiac rhythm was asystole in 87 patients. Return of spontaneous circulation was obtained in 30 patients. The cutoff value of 10 torr for maximal end-tidal CO2 during the first 20 mins after tracheal intubation provided an observed sensitivity of 100% in predicting return of spontaneous circulation with a specificity of 67%. This result allows rejection of the hypothesis of an actual sensitivity of < or = 90% (p = .042). By contrast, the observed sensitivity of initial end-tidal CO2 was only 87%. CONCLUSIONS End-tidal CO2 represents a valuable tool for monitoring patients presenting with asystole during prehospital CPR. Fluctuations in end-tidal CO2 during CPR and the utility of end-tidal CO2 in detecting return of spontaneous circulation justify its continuous measurement. In addition, a high sensitivity (>90%) in predicting return of spontaneous circulation is prospectively demonstrated using the maximal end-tidal CO2 during the first 20 mins after tracheal intubation, with a cutoff value of 10 torr. Such a prognostic indicator could be used for a more rational approach to prolonged CPR.
Aminopeptidase N Activity Predicts 5-Year Survival in Colorectal Cancer Patients

Background Aminopeptidase N (APN; EC 3.4.11.2) is a membrane dimeric metallopeptidase involved in differentiation, development, and proliferative processes of several tissues. Recent studies have demonstrated the increased expression and activity of this enzyme in several cancers. However, there are no available data about the impact of this peptidase in the biological aggressiveness and the survival of colorectal cancer (CRC) patients. Methods The activity and mRNA expression of APN in tumor tissue (n = 81) and plasma (n = 40) of patients with CRC of low and high grades and stages were prospectively analyzed by fluorimetric and quantitative reverse transcriptase–polymerase chain reaction methods. Data obtained in adenoma and CRC were compared with those from the surrounding normal mucosa. Classic clinical and pathological parameters were stratified following APN data and analyzed for 5-year survival. Results mRNA levels of APN (ANPEP) were lower in colorectal adenomas and adenocarcinomas than in the surrounding uninvolved mucosa (Kruskal-Wallis, P < 0.001). Aminopeptidase N activity in CRC tissue was higher in patients with better overall survival (log-rank P < 0.05, Cox analysis P < 0.05). By contrast, higher plasmatic APN activity correlated with worse overall survival (log-rank P < 0.01, Cox analysis P < 0.05). Conclusions Aminopeptidase N activity in tissue and plasma from CRC patients is an independent prognostic factor of 5-year survival. The determination of APN activity levels in the plasma may be a safe, minimally invasive, and inexpensive way to define the aggressiveness of CRC in daily practice.
Behavioral Intention of Using Social Networking Site: A Comparative Study of Taiwanese and Thai Facebook Users

Although major contributions are being made by Social Networking Sites (SNS) in communications and e-commerce, very little attention has been given to its implementation. This study contributes to technology and human interaction domain by (1) extending the technology acceptance model (TAM), personality trait and telepresence in developing a comparative mode based on the behavioral intention, (2) testing the model with Partial Least Square (PLS) using Facebook user's data; and (3) comparing result across a developed (Taiwan) and an emerging (Thailand) economy. Results indicate TAM was to fit to test the behavioral intention model in these two economies. The findings support for the telepresence, perceived usefulness, and perceived ease of use, attitude and behavioral intention; however, the effect levels are different in these two countries (Taiwan vs. Thailand). In addition, only extraversion, conscientiousness, agreeableness, and neuroticism of the big-five personality have been discussed.
Simultaneous Primary and Secondary Syphilis Associated with Syphilitic Alopecia and Folliculitis in an HIV Positive Patient

Syphilis has been classically divided into three clinical stages. The chancre that appears at the site of inoculation is referred to as the primary stage. The secondary stage is characterized by systemic involvement and the appearance of a disseminated maculopapular rash. Cardiovascular, neurologic and gummatous lesions characterize tertiary syphilis. The simultaneous presentation of primary and secondary syphilis has been reported because the chancre can persist into the secondary stage, especially in HIV positive patients. Although syphilitic alopecia is a rare manifestation of secondary syphilis it is an important differential diagnosis in the evaluation of patients with patchy hair loss. This article aims to present the case of a 34-year-old HIV-positive male patient that presented simultaneous primary and secondary syphilis associated with syphilitic alopecia and acute bacterial folliculitis.
The Description of the Eggs of Toxorhynchites moctezuma (Diptera: Culicidae) from Trinidad, West Indies With notes on other eggs.

A description of the eggs of Toxorhynchites moctezwl2a is presented, accompanied with photographs using both light and electron microscopy. Field observations on the oviposition behavior of this species are also described. In addition, the eggs of five Toxorhynchites species are compared and three photographed.
Adoption of Electronic Data Interchange in Small and Medium-Sized Enterprises

As more and more small- and medium-sized enterprises (SMEs) adopt information technology (IT) in their daily business operations and even in their strategic planning, the positive impacts of IT are no longer a privilege of large organizations. However, there has been little research conducted and published on the adoption of electronic data interchange (EDI) in SMEs. Most previous studies on EDI in SME used the case study approach, thus limiting the generalizability of their findings. This study adopts the survey approach to conduct a large-scale empirical study of the key factors that influence EDI adoption in the SME context. A research model consisting of seven factors under three categories, namely characteristics of innovation, organizational context and external influence was proposed and tested against data collected from 644 SME using logistic regression analysis. The findings indicate that the critical factors that determine EDI adoption in the SMEs context are perceived direct benefits, perceived cost, IT knowledge, government incentives and enforcement, and trading partnersâ€™ influence. Based on these findings, implications for both research on and practice of adoption of EDI in SMEs are provided.