Miracle-dz/UniFAR-FTUs huggingface dataset:
Gravitational-Wave Detection and Astrophysics with Pulsar Timing Arrays

We have begun an exciting era for gravitational wave detection, as several world-leading experiments are breaching the threshold of anticipated signal strengths. Pulsar timing arrays (PTAs) are pan-Galactic gravitational wave detectors that are already cutting into the expected strength of gravitational waves from cosmic strings and binary supermassive black holes in the nHz-$\mu$Hz gravitational wave band. These limits are leading to constraints on the evolutionary state of the Universe. Here, we provide a broad review of this field, from how pulsars are used as tools for detection, to astrophysical sources of uncertainty in the signals PTAs aim to see, to the primary current challenge areas for PTA work. This review aims to provide an up-to-date reference point for new parties interested in the field of gravitational wave detection via pulsar timing.
Active Galactic Nuclei with a Low-metallicity Narrow-line Region

Low-metallicity active galactic nuclei (AGNs) are interesting to study for the early phase of AGN evolution. However, most AGNs are chemically matured, and accordingly, low-metallicity AGNs are extremely rare. One approach to search for low-metallicity AGNs systematically is utilizing the so-called BPT diagram that consists of the [O iii]λ5007/Hβ and [N ii] /Hα flux ratios. Specifically, photoionization models predict that low-metallicity AGNs show a high [O iii]λ5007/Hβλ4861 ratio and a relatively low [N ii]λ6584/Hαλ6563 ratio that corresponds to the location between the sequence of star-forming galaxies and that of usual AGNs on the BPT diagram (hereafter “the BPT valley”). However, other populations of galaxies such as star-forming galaxies and AGNs with a high electron density or a high-ionization parameter could be also located in the BPT valley, not only low-metallicity AGNs. In this paper, we examine whether most of the emission-line galaxies at the BPT valley are low-metallicity AGNs or not. We select 70 BPT-valley objects from 212,866 emission-line galaxies obtained by the Sloan Digital Sky Survey. Among the 70 BPT-valley objects, 43 objects show firm evidence of the AGN activity, i.e., the He iiλ4686 emission and/or weak but significant broad Hα emission. Our analysis shows that those 43 BPT-valley AGNs are not characterized by a very high gas density nor ionization parameter, inferring that at least 43 among 70 BPT-valley objects (i.e., %) are low-metallicity AGNs. This suggests that the BPT diagram is an efficient tool to search for low-metallicity AGNs.
Terahertz emission from ZnGeP_2: phase-matching, intensity, and length scalability

Collinear phase-matched optical rectification is studied in ZnGeP2 pumped with near-infrared light. The pump-intensity dependence is presented for three crystal lengths (0.3, 1.0, and 3.0 mm) to determine the effects of linear optical absorption, nonlinear optical absorption, and terahertz free-carrier absorption on the generation. Critical parameters such as the coherence length (for velocity matching), dispersion length (for linear pulse broadening), and nonlinear length (for self-phase modulation) are determined for this material. These parameters provide insight into the upper limit of pulse intensity and crystal length required to generate intense terahertz pulses without detriment to the pulse shape. It is found that 1 mm thick ZnGeP2(012), pumped at 1.28 μm with intensity of ∼15 GW/cm2, will produce intense undistorted pulses, whereas longer crystals or larger intensities modify the pulse shape to varying degrees. Moreover, phase-matching dispersion maps are presented for the terahertz generation over a large tuning range (1.1–2.4 μm) in the longer (3 mm) crystal, demonstrating the phase-matching bandwidth and phase mismatch that leads to fringing associated with multipulse interference. All observed results are simulated numerically showing good qualitative agreement.
THE SIZE, STRUCTURE, AND IONIZATION OF THE BROAD-LINE REGION IN NGC 3227

Hubble Space Telescope spectroscopy of the Seyfert 1.5 galaxy, NGC 3227, confirms previous reports that the broad Hα emission line flux is time variable, decreasing by a modest ∼11% between 1999 and 2000 in response to a corresponding ∼37% decrease in the underlying continuum. Modeling the gas distribution responsible for the broad Hα, Hβ, and Hγ emission lines favors a spherically symmetric inflow as opposed to a thin disk. Adopting a central black hole mass of 7.6 × 106 M☉, determined from prior reverberation mapping, leads to the following dimensions for the size of the region emitting the broad Hα line: an outer radius ∼90 lt-days and an inner radius ∼3 lt-days. Thus, the previously determined reverberation size for the broad-line region (BLR) consistently coincides with the inner radius of a much larger volume of ionized gas. However, the perceived size of the BLR is an illusion, a consequence of the fact that the emitting region is ionization bounded at the outer radius and diminished by Doppler broadening at the inner radius. The actual dimensions of the inflow remain to be determined. Nevertheless, the steady-state mass inflow rate is estimated to be ∼10−2 M☉ yr−1 which is sufficient to explain the X-ray luminosity of the active galactic nucleus (AGN) in terms of radiatively inefficient accretion. Collectively, the results challenge many preconceived notions concerning the nature of BLRs in AGNs.
Presequence translocase-associated motor subunits of the mitochondrial protein import apparatus are dual-targeted to mitochondria and plastids

The import and assembly of most of the mitochondrial proteome is regulated by protein translocases located within the mitochondrial membranes. The Presequence Translocase-Associated Motor (PAM) complex powers the translocation of proteins across the inner membrane and consists of Hsp70, the J-domain containing co-chaperones, Pam16 and Pam18, and their associated proteins Tim15 and Mge1. In Arabidopsis, multiple orthologues of Pam16, Pam18, Tim15 and Mge1 have been identified and a mitochondrial localization has been confirmed for most. As the localization of Pam18-1 has yet to be determined and a plastid localization has been observed for homologues of Tim15 and Mge1, we carried out a comprehensive targeting analysis of all PAM complex orthologues using multiple in vitro and in vivo methods. We found that, Pam16 was exclusively targeted to the mitochondria, but Pam18 orthologues could be targeted to both the mitochondria and plastids, as observed for the PAM complex interacting partner proteins Tim15 and Mge1.
Emotional Labor in Everyday Resilience: Class-Based Experiences of Navigating Unemployment Amid the COVID-19 Pandemic in the U.S.

During the COVID-19 global health crisis, institutions, policymakers, and academics alike have called for practicing resilience to overcome its ongoing disruptions. This paper contributes a comparative study of the job search experiences of working-class and upper-middle-class job seekers, particularly in relation to their resilience practices during the pandemic. Drawing from in-depth interviews with 12 working-class and 11 upper-middle-class job seekers in the U.S., we unpack challenges resulting from both the pandemic and unemployment and job seekers' novel practices of navigating these challenges in their everyday disrupted life. Job seekers' ongoing negotiation with their resources, situations, and surroundings gives practical meanings to building everyday resilience, which we theorize as an ongoing process of becoming resilient. While job seekers across classes experienced similar challenges, working-class job seekers took on additional emotional labor in their everyday resilience due to their limited experience in the digital job search space, competition with higher-degree holding job seekers applying for the same jobs, limited social support networks, and at times, isolation. By foregrounding the uneven distribution of emotional labor in realizing the promise of resilience along class lines, this work cautions against the romanticization of resilience and calls for a more critical and nuanced understanding of resilience in CSCW.
Two-dimensional transition metal carbides and nitrides (MXenes) based biosensing and molecular imaging

Abstract As a “star material”, 2D transition metal carbides and/or nitrides (MXenes) have tremendous potential applications in biosensor development and molecular imaging. MXenes have a lot of advantages due to their large specific surface, excellent electrical conductivity, adjustable band gap, and easy modification. MXenes that immobilized with DNA strands, proteins, enzymes, or other bioluminescent materials on the surface, have been used to measure small molecules with extraordinary sensitivity and remarkable limit of detection. This review provides an overview of most recent development in the synthesis, fundamental properties, biosensing, and molecular imaging applications of MXenes. We focused on molecular detection through MXene-based electrochemical properties their challenges and novel opportunities of MXenes in biological applications. This article will provide a guide for researchers who are interested in the application of MXenes biosensors.
Stratification, superfluidity and magnetar QPOs

The violent giant flares of magnetars excite QPOs which persist for hundreds of seconds, as seen in the X-ray tail following the initial burst. Recent studies, based on single-fluid barotropic magnetar models, have suggested that the lower-frequency QPOs correspond to magneto-elastic oscillations of the star. The higher frequencies, however, in particular the strong 625 Hz peak, have proved harder to explain, except as high mode multipoles. In this work we study the time evolutions of non-axisymmetric oscillations of two-fluid Newtonian magnetars with no crust. We consider models with superfluid neutrons and normal protons, and poloidal and toroidal background field configurations. We show that multi-fluid physics (composition-gradient stratification, entrainment) tends to increase Alfven mode frequencies significantly from their values in a single-fluid barotropic model. The higher-frequency magnetar QPOs may then be naturally interpreted as Alfven oscillations of the multi-fluid stellar core. The lower-frequency QPOs are less easily explained within our purely fluid core model, but we discuss the possibility that these are crustal modes.
The γ-ray pulsar J1932+1916 in X-rays

We report the results of a simultaneous analysis of the archival Suzaku and Swift X-ray data of the γ-ray pulsar J1932+1916 field. A point-like source and diffuse emission around it were detected at the γ-ray position of the pulsar. Their spectral properties allow one to suggest that Suzaku and Swift detected the X-ray counterpart of PSR J1932+1916. Using of the interstellar absorption–distance relations, we constrain the distance to the pulsar in the range of 2–6 kpc. We also discuss a possible association of the pulsar with the supernova remnant G54.4–0.3.
Do as I say, not as I do: Therapist Evaluation of a Practice and Supervision Aid

Interactive software offers the potential to improve the quality of mental health care by promoting skill development, clinical insight, and shared reflection among mental health professionals. However, research on therapists' usage of interactive software has been primarily based in training and mock-clinical settings. In this paper, we present a qualitative study of clinicians' experience using CORE-MI, a collaborative recording and annotation software, in a real-world university counseling center. We describe how and why therapists, both trainees and licensed staff, used CORE-MI to support their practice and improve their skills. We also consider how usage varied with therapists' developmental level and how the software impacted relationships between supervisors and supervisees. Finally, we offer recommendations for future research and design of interactive systems in mental health settings.
Can Humans Detect Malicious Always-Listening Assistants? A Framework for Crowdsourcing Test Drives

As intelligent voice assistants become more widespread and the scope of their listening increases, they become attractive targets for attackers. In the future, a malicious actor could train voice assistants to listen to audio outside their purview, creating a threat to users' privacy and security. How can this misbehavior be detected? Due to the ambiguities of natural language, people may need to work in conjunction with algorithms to determine whether a given conversation should be heard. To investigate how accurately humans can perform this task, we developed a framework for people to conduct "Test Drives" of always-listening services: after submitting sample conversations, users receive instant feedback about whether these would have been captured. Leveraging a Wizard of Oz interface, we conducted a study with 200 participants to determine whether they could detect one of four types of attacks on three different services. We studied the behavior of individuals, as well as groups working collaboratively, and investigated the effects of task framing on performance. We found that individuals were able to successfully detect malicious apps at varying rates (7.5% to 75%), depending on the type of malicious attack, and that groups were highly successful when considered collectively. Our results suggest that the Test Drive framework can be an effective tool for studying user behaviors and concerns, as well as a potentially welcome addition to voice assistant app stores, where it could decrease privacy concerns surrounding always-listening services.
Nationalizing the Internet to Break a Protest Movement: Internet Shutdown and Counter-Appropriation in Iran of Late 2019

To deal with a spontaneous civil uprising following a substantial rise in gas prices, the Iranian security apparatus imposed in late 2019 techno-political measures and blocked access to international websites and services. To analyze these measures, we conducted 19 interviews with Iranians living inside and outside the country. We argue that the concept of the shutdown, as portrayed in Western media, is not perfectly suitable to describe the infrastructural restrictions and propose the concept of an internet nationalization. This paper offers an in-depth analysis of what the nationalization meant and how it affected the lives of Iranians participating or not participating in the protests. We also report on a variety of creative measures, both technical and non-technical, Iranians took to counter-appropriate the government-imposed shutdown of international connectivity. Based on these data, we elaborate on the concept of counter-appropriation.
Supernova neutrino oscillations: What do we understand?

We summarize our current understanding of the neutrino flavor conversions inside a core collapse supernova, clarifying the important role played by the collective effects in determining flavor conversion probabilities. The potentially observable νe and e spectra may help us identify the neutrino mixing scenario, distinguish between primary flux models, and learn more about the supernova explosion.
What lattice theorists can do for superstring/M-theory

The gauge/gravity duality provides us with nonperturbative formulation of superstring/M-theory. Although inputs from gauge theory side are crucial for answering many deep questions associated with quantum gravitational aspects of superstring/M-theory, many of the important problems have evaded analytic approaches. For them, lattice gauge theory is the only hope at this moment. In this review I give a list of such problems, putting emphasis on problems within reach in a five-year span, including both Euclidean and real-time simulations.
You Are Not Alone

People experience various stressful events in their daily lives. Receiving social support, especially from peers who went through a similar experience, helps individuals cope with such stress. We propose StressTrendmeter, a mobile application that targets college students for anonymously sharing the source of stress via the form of hashtags, viewing stress topics based on trends, and providing social support through the empathy button and hashtag-based chat. We deployed StressTrendmeter to 222 students from two universities for five weeks. With hashtags and trending features, students found StressTrendmeter (i)helpful to spontaneously yet concisely articulate their stress topics and (ii) easy to browse through and become aware of issues around the campus. Our study reveals that social sharing with StressTrendmeter brought awareness, resonance, and accountability as students empathized and expressed support. Based on our study, we share design implications for social support systems with community awareness.
"That Robot Played with Us!" Children's Perceptions of a Robot after a Child-Robot Group Interaction

The design of child-centred, intelligent and collaborative robots is a challenging endeavour, which requires to understand how the implemented robot behaviours and collaboration paradigms affect children's perception about the robot. This paper presents the results of a set of semi-structured interviews of N=81, 5 to 8 years old children who previously interacted in pairs with a robot in the context of a problem-solving task. We manipulated two different factors of the robot behaviour: cognitive reliability in logic game movements (optimal vs sub-optimal) and expressivity in the communication (expressive vs neutral) and we assigned the children in one of the four conditions. At post-intervention interviews, we examined children's perceptions on the robot's attributions, collaboration and social role. Results indicate that a robot's cognitive reliability shapes the helping relationship between the children and the robot, while the robot's expressivity impacts children perception of the robot supportive ability and friendship. Finally, results also indicate that, even if children interact in pairs with the robot, their perceptions about it remain individual, although a good collective task-performance seems to empower children perception of the robot in terms of friendship and reliability.
N131: A dust bubble born from the disruption of a gas filament

Context. OB-type stars have strong ionizing radiation and drive energetic winds. The ultraviolet radiation from ionizing stars may heat dust and ionize gas to sweep up an expanding bubble shell. This shell may be the result of feedback leading to a new generation of stars. Aims. N131 is an infrared dust bubble residing in a molecular filament. We study the formation and fragmentation of this bubble with multiwavelength dust and gas observations. Methods. Towards the bubble N131, we analysed archival multiwavelength observations including 3.6, 4.5, 5.8, 8.0, 24, 70, 160, 250, 350, 500 μm, 1.1 mm, and 21 cm. In addition, we performed new observations of CO (2–1), CO (1–0), and 13 CO (1–0) with the IRAM 30 m telescope. Results. Multiwavelength dust and gas observations reveal a ring-like shell with compact fragments, two filamentary structures, and the secondary bubble N131-A. Bubble N131 is a rare object with a large hole at 24 μm and 21 cm in the direction of its centre. The dust and gas clumps are compact and might have been compressed at the inner edge of the ring-like shell, while they are extended and might be pre-existing at the outer edge. The column density, excitation temperature, and velocity show a potentially hierarchical distribution from the inner to outer edge of the ring-like shell. We also detected the front and back sides of the secondary bubble N131A in the direction of its centre. The derived Lyman-continuum ionizing photon flux within N131-A is equivalent to an O9.5 star. Based on the above, we suggest that the bubble N131 might be triggered by the strong stellar winds from a group of massive stars inside the bubble. Conclusions. We propose a scenario in which the bubble N131 forms from the disruption of a gas filament by the expansion of the H II region, strong stellar winds, and fragments under self-gravity.
A Multi-Objective Optimization Framework for Redirecting Pointing Gestures in Remote-Local Mixed/Augmented Reality

Collaborative augmented reality is an emerging field with the promise of simulating natural human-human interactions from remote locations. Users, represented by their photorealistic avatars, and relevant objects in their scenes can be teleported to each other's environments, with the capability of tracking their gaze, body pose, and other nonverbal behaviors using modern augmented reality devices. Pointing gestures play a key role for users to communicate about aspects related to their environment. Also, the body pose one uses during pointing, relays cues of the user's intentions and nonverbal behaviors during the interaction. Due to dissimilarities in multiple users’ environments, pointing gesture needs to be redirected since direct animation of the user's motion onto its avatar may introduce error. At the same time, the nonverbal behavior represented by the body pose also needs to be preserved for realistic interaction. While these objectives are not mutually exclusive, current approaches only solve the redirection of the gesture without preserving the body pose. In this paper, we present a systematic approach to solving the dual problem of redirection of gesture as well as preserving the body pose using a multi-objective optimization framework. The presented framework efficiently adjusts the weighting between the two objectives and gives the user the flexibility to set the minimum angular error tolerance for the pointing gesture redirection. We have tested our approach with the current state-of-the-art using both pointing gesture reference poses and redirecting against continuous gesture actions collected from an augmented reality human participant study. Results show that for a given user-defined error tolerance, our approach has a decrease of 33.5% in body pose error vs current-state-of-the-art for pointing gesture reference poses and 33.6% for pointing gestures recorded during the human participant study.
Interrogating Data Work as a Community of Practice

We apply Lave & Wenger's construct of a community of practice to identify and position members of the data work community of practice, focusing on members on the periphery who have received less attention - as compared to full practitioners (e.g., data scientists). Reporting on results of interviews with 19 civic workers who perform data work as their main task, we identify an atypical relationship between subject-domain experts (such as our interviewees) and full members of the data work community. Our interviewees may have less computational skill in data work, but they have extensive and varied practices to engage in data contextualization that data scientists and other full community members could learn from. In identifying the attributes of data workers on the periphery, we also hope to call attention to the challenges they face in performing data work in low resources institutions (e.g., governmental, non-profit). Our findings contribute to the larger conversations in human-centered data science about who performs data work and how they go about it, in order to addresses questions of power, fairness, and bias in data-intensive systems.
Moderation as Empowerment: Creating and Managing Women-Only Digital Safe Spaces

This paper explores the creation, management and moderation of women-only online groups as digital safe spaces. We interview eleven founders and moderators of six distinct, closed, women-only Facebook groups that predominantly cater to women in and from the Global South. The study provides insights into the motivations and mechanisms for creating and moderating these safe spaces, the affordances of social networking sites that enable or hinder the creation and moderation of such spaces and finally, and the deep impact moderating such spaces has on the women who manage them. Based on these findings we discuss suggestions for specific technological affordances to enable and support digital safe spaces for marginalized and vulnerable communities.