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Don't torque like that. Measuring compact object magnetic fields with analytic torque models
No full textContext. Changes of the rotational period observed in various magnetized accreting sources are generally attributed to the interaction between the in-falling plasma and the large-scale magnetic field of the accretor. A number of models have been proposed to link these changes to the mass accretion rate, based on different assumptions on the relevant physical processes and system parameters. For X-ray binaries with neutron stars, with the help of precise measurements of the spin periods provided by current instrumentation, these models render a way to infer such parameters as the strength of the dipolar field and a distance to the system. Often, the obtained magnetic field strength values contradict those from other methods used to obtain magnetic field estimates. Aims. We want to compare the results of several of the proposed accretion models. To this end an example application of these models to data is performed. Methods. We reformulate the set of disk accretion torque models in a way that their parametrization are directly comparable. The application of the reformulated models is discussed and demonstrated using Fermi/GBM and Swift/BAT monitoring data covering several X-ray outbursts of the accreting pulsar 4U 0115+63. Results. We find that most of the models under consideration are able to describe the observations to a high degree of accuracy and with little indication for one model being preferred over the others. Yet, derived parameters from those models show a large spread. Specifically the magnetic field strength ranges over one order of magnitude for the different models. This indicates that the results are heavily influenced by systematic uncertainties.This research was supported by the International SpacenScience Institute ISSI in Bern through ISSI International Team project 495 Feeding the spinning top GV acknowledges support from the Hellenic Foundation for Research and Innovation H F R I through the project ASTRAPE Project ID 7802 CM acknowledges funding from the Italian Ministry of University and Research MUR PRIN 2020 prot 2020BRP57Z Gravitational and Electro magnetic wave Sources in the Universe with current and next generation detectors GEMS and the INAF Research Grant Uncovering the optical beat of the fastest magnetised neutron stars FANS JW and ESL acknowledge support from Deutsche Forschungsgemeinschaft grant WI 1860 11 2https://www.aanda.org/articles/aa/abs/2025/06/aa53809-25/aa53809-25.htm
Predicting Students' Interest from Small Group Conversational Characteristics: Insights from an AI Literacy Education with High School Students
No full textSIGCSETS 2025: Proceedings of the 56th ACM Technical Symposium on Computer Science Education V. 2, Pittsburgh PA USA, 26 February 2025- 1 March 2025Recent years have seen developments in AI instructional practices for K-12 students. In literature, students' interest in AI is shown to correlate with gaining AI knowledge; however, little is known about how AI interest manifests in classroom discourses during AI literacy lessons. This study examined students' participation in an integrated AI curriculum delivered to a cognitive science class in a high school in the southern US. Students worked in small groups and built a supervised machine learning model to recognize kids' drawings at different stages of artistic development. Our analysis showed that semantic features extracted from students' small group conversations significantly predicted their interest in learning AI. However, we found no significant relationship between students' social construction of knowledge and their interests. This study sheds light on the relationship between the learning process and interest; when further developed, this analysis may be developed into a classroom activity analytics tool that may provide real-time feedback to teachers engaged in AI literacy education to enhance teaching effectiveness in this nascent content area.This material is based upon work supported by the National Science Foundation DRL2333098, OIA2218046, and CNS1953544.https://dl.acm.org/doi/10.1145/3641555.370523
The feedback between morphogens and shape
No full textPatterning and morphogenesis in multicellular organisms require precise dynamic coordination between cellular behaviors and mechano-chemical signals. However, the mechanisms underlying the pathways that coordinate and integrate these signals into emergent cellular behaviors and tissue shapes remain poorly understood. Here, we present a cell-centered agent-based mathematical approach to shed light on the feedback mechanisms underlying tissue growth and pattern formation. The model includes cell size dynamics governed by both intercellular diffusible morphogen concentrations and mechanical stress between cells to control their spatial organization, and does not require the use of any superimposed lattice, increasing its applicability and performance. The results show how the precise integration of the feedback loop between cellular behaviors and mechano-chemical signaling is essential for the regulation of shape and spatial patterns across the tissue scale. Furthermore, the regulation of cellular dynamics by patterning processes, such as Turing activator-inhibitor systems, can drive the formation of emergent stable tissue shapes, which, in turn, specify the domain for morphogen patterning? closing the self-regulated loop between tissue shape and morphogenetic signals. Overall, this study highlights the importance of the feedback loop between morphogen patterning and cellular behaviors in regulating tissue growth dynamics and stable shape formation. Moreover, this study establishes a framework for further experiments to understand the regulatory dynamics of whole-body development and regeneration using high spatiotemporal resolution models.Significance Tight coordination and interpretation of the multitude of signals at different biological scales are essential during the development of multicellular organisms to control their shape, size, and pattern. In this work, we investigated the leading role of the feedback between mechano-chemical signaling networks and tissue shape through cellular behaviors such as growth, proliferation, and apoptosis. The model explains the interdependence between tissue growth and pattern formation mechanisms in regulating the fundamental properties of morphogenesis. Overall, this study provides mechanistic insights into the regulatory feedback interactions between tissue morphogenesis and patterning dynamics.We thank the members of the Lobo Lab for helpful discussions. This work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number R35GM137953. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Computations used the UMBC High Performance Computing Facility (HPCF) supported by the NSF MRI program grants CNS-1920079 and OAC-1726023.https://www.biorxiv.org/content/10.1101/2025.02.16.638504v
Understanding what information is available to pregnant women through HHS agencies (NIH, CDC, FDA) and how has it changed over time
No full textD.P.A. -- The University of
Baltimore, 2025Public scholarship project submitted to the College of Public Affairs of The University of Baltimore in partial fulfillment of the requirements for the degree of Doctor of Public AdministrationDoes the government provide accurate, intergraded pregnancy health information to its citizens? My research showed that the federal government does provide accurate public health information on different HHS agencies (NIH, CDC, FDA) over time. Historical data shows that the agencies could improve their communication strategy and make it easier for the consumer to access their information. The biggest challenge is the findability of that information. Agencies should work to incorporate their communication strategy to the public and make the information available, easily accessible to the consumer
Long term variability of Cygnus X-1. IX. A spectral-timing comparison of Cygnus X-1 and MAXI J1820+070 in the hard state
No full textCygnus X-1 is a persistent, high-mass black hole X-ray binary (BHXRB) which in the hard state shows many similar properties to transient BHXRBs, along with intriguing differences, such as the lack of quasi-periodic oscillations. Here, we compare for the first time the detailed spectral-timing properties of Cyg X-1 with a transient BHXRB, MAXI J1820+070, combining data from XMM-Newton and NICER with contemporaneous INTEGRAL data to study the power spectra, rms spectra and time-lags over a broad 0.5–200 keV range. We select bright hard state MAXI J1820+070 data with similar power-spectral shapes to the Cyg X-1 data, to compare the source behaviours while accounting for the evolution of spectral-timing properties, notably the lags, through the hard state. Cyg X-1 shows no evidence for soft lags in the 1–10 Hz frequency range where they are clearly detected for MAXI J1820+070. Furthermore the low-frequency hard lags and rms-spectra evolve much more strongly during the hard state of Cyg X-1 than for MAXI J1820+070. We argue that these differences cannot be explained by the different black hole masses of these systems, but may be related to their different accretion rates and corresponding locations on the hardness-intensity diagram. We conjecture that there is a significant luminosity-dependence of coronal geometry in the hard state of BHXRBs, rather than an intrinsic difference between Cyg X-1 and transient BHXRBs. This possibility has also been suggested to explain a common time-lag feature that appears in the hard intermediate states of Cyg X-1 and transient BHXRBs.The authors would like to thank the anonymous referee for their suggestions, which improved the quality and clarity of this work. This work uses Stingray, a Python library developed for timesseries analysis which supports a range of commonly-used Fourier analysis techniques (Huppenkothen et al. 2019), and AstroPy, a community-developed core Python package along with an ecosystem of tools and resources for astronomy (Astropy Collaboration et al. 2022). Additionally, we have extensively utilized NumPy (Harris et al. 2020), SciPy (Virtanen et al. 2020), and Matplotlib (Hunter 2007) in this work. BDM acknowledges support via Ramón y Cajal Fellowship (RYC2018-025950-I), the Spanish MINECO grants PID2020-117252GB-I00, PID2022-136828NB-C44, and the AGAUR/Generalitat de Catalunya grant SGR-386/2021. EVL is supported by the Italian Research Center on High Performance Computing Big Data and Quantum Computing (ICSC), a project funded by European Union – NextGenerationEU – and National Recovery and Resilience Plan (NRRP) – Mission 4 Component 2 within the activities of Spoke 3 (Astrophysics and Cosmos Observations). KP is supported by NASA under award number 80GSFC24M0006. For the purpose of open access, the authors have applied a Creative Commons Attribution license to the Author Accepted Manuscript version arising from this submission.https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/staf1155/820282
Like A Good Neighbor: The Role of Neighbors in Career Choice
No full textSocial Science History Association, 2025 Annual Meeting Chicago, Illinois, November 20-23, 2025.There is growing evidence that where a child grows up has long-run, economic mobility consequences. We explore the role of neighbors in this place-based transmission. Using linked census records for over 6 million boys and 4 million girls and historic census sheet microgeography, we estimate how growing up next door to someone in a particular occupation affects a child’s probability of working in that occupation as an adult, relative to other children who grew up further down the street. Living next door to someone as a child increases the probability of having the same occupation as them 30 years later by about 10 percent. High income, high education occupations are more transmissible, and ethnic, race, and child age homophily strengthens transmission, consistent with information and exposure channels. Childhood neighbors have real economic consequences. Children who grow up next to neighbors in high income occupations, such as doctors or lawyers, see gains in income and education, even relative to other children living on the same street, suggesting that neighborhood networks significantly contribute to economic mobility.https://ssha2025.ssha.org/abstracts/25049
Fiber-to-fiber loop-based quantum memory for photonic polarization qubits
No full textOptica Quantum 2.0 Conference 2025, San Francisco United States, 1–5 June 2025We demonstrate a loop-based quantum memory with single-mode input and output for ultra-broadband polarization qubits. Visibility and fidelity results will be presented for heralded photons with reconfigurable storage times of 36.5 ns and 526 ns.https://opg.optica.org/abstract.cfm?uri=QUANTUM-2025-QM4A.
Characterization of the Excited States of 4-Amino-1,8-naphthalimides Towards an Understanding of Interactions with Proteins and Amino Acids
No full textLight is increasingly used in the development and design of new molecules in a variety of applications. Light is used as an initiator for chemical reactions, as a tool to excite photoactive molecules into a more reactive state, and as an energy source for imaging purposes. The use of photoactive molecules in biomedicine is of great interest due to the versatility and efficacy of the intended applications. One such application is the photochemical crosslinking of tissues, or ‘tissue welding,’ as a method of wound healing and an alternative to sutures. This is especially of interest for tissues which are unable to be easily treated with sutures, such as cartilaginous joint tissues in the knee. 4-Amino-1,8-naphthalimides were synthesized to evaluate them as photochemical crosslinkers and determine the efficiency of blue-light excitation. The 4-amino-1,8-naphthalimides were differentiated by the nature of the azacyclic or dimethyl 4-amino moiety and the imide substituent. The 4-amino substituents were chosen to determine the effect of ring size on the ability of the ring to enter a twisted intramolecular charge transfer state. Entering this state can change fundamental properties such as fluorescence quantum yield and excited state energies, as well as oxidation-reduction potentials, which would contribute to the reactivity for oxidative crosslinking. The photophysical properties of the 4-amino-1,8-naphthalimides were determined through absorption and steady-state fluorescence spectroscopy, as well as time-correlated single photon counting. Fluorescence quantum yields and fluorescence lifetimes were calculated, and photochemical reactivity with oxidizable amino acids and proteins were determined. Dynamic singlet-state quenching of fluorescence intensity was observed in the presence of L-tryptophan, and dynamic fluorescence intensity enhancement was observed in the presence of L-histidine or a glycine-tyrosine dipeptide. Dynamic singlet-state quenching of fluorescence lifetimes was observed in the presence of oxidizable amino acids. Static fluorescence enhancement was observed in the presence of protein (bovine serum albumin or lysozyme). The rate constants of dynamic quenching with L-tryptophan (~2-3.5 x 109 M-1 s-1) were up to one or two orders of magnitude greater than the rate constants for quenching with L-histidine (0.4-3.2 x 108 M-1 s-1) or a glycine-tyrosine dipeptide (0.55-1.1 x 109 M-1 s-1). Gel electrophoresis experiments showed that photoinduced oxidative crosslinking did not occur with either bovine serum albumin or lysozyme after multiple hours of blue-light irradiation of the ANIs