UNPs as HEDP simulators

Dynamically studying trans-Neptunian object (TNO) binaries allows us to measure masses and orbits. Most of the known objects appear to have only two components, except (47171) Lempo, which is the single known hierarchical triple system with three similar-mass components. Though hundreds of TNOs have been imaged with high-resolution telescopes, no other hierarchical triples (or trinaries) have been found among solar system small bodies, even though they are predicted in planetesimal formation models such as gravitational collapse after the streaming instability. By going beyond the point-mass assumption and modeling TNO orbits as non-Keplerian, we open a new window into the shapes and spins of the components, including the possible presence of unresolved "inner" binaries. Here we present evidence for a new hierarchical triple, (148780) Altjira (2001 UQ18), based on non-Keplerian dynamical modeling of the two observed components. We incorporate two recent Hubble Space Telescope observations, leading to a 17 yr observational baseline. We present a new open-source Bayesian point-spread function fitting code called nPSF that provides precise relative astrometry and uncertainties for single images. Our non-Keplerian analysis measures a statistically significant (∼2.5σ) nonspherical shape for Altjira. The measured J2 is best explained as an unresolved inner binary, and an example hierarchical triple model gives the best fit to the observed astrometry. Using an updated non-Keplerian ephemeris (which is significantly different from the Keplerian predictions), we show that the predicted mutual event season for Altjira has already begun, with several excellent opportunities for observations through ∼2030.

This research describes the changes made to a physics course for preservice elementary teachers during the COVID-19 pandemic and their efforts to engage in constructing scientific explanations in virtual learning. The preservice teachers engaged in three types of virtual labs: simulations, video analysis, and observations. We evaluated the participants’ performance in constructing scientific explanations with a Level of Sophistication rubric scoring engagement from novice to expert levels. We collected data from three cohorts: 2019 (pre-pandemic) and 2020–21 (mid-pandemic), in the form of course documents, interviews, and student lab submissions. We analyzed the data using a-priori and open coding methods as well as applying descriptive statistics and a series of ANOVA tests to the rubric results. We found that the participants (new to science practice) on average engaged at an intermediate level, but were more sophisticated when they used reasoning that included scientific models, theory, or mathematical thinking. Students can successfully engage in constructing explanations in virtual contexts when provided with opportunities to collect their own data through virtual experimentation. This is especially true when scaffolding is in place to prompt sensemaking. The reasoning in their explanations provides a glimpse at the mental models that drive their reasoning and sensemaking.

The physical and orbital parameters of trans-Neptunian objects provide valuable information about the solar system's formation and evolution. In particular, the characterization of binaries provides insights into the formation mechanisms that may be playing a role at such large distances from the Sun. Studies show two distinct populations, and (38628) Huya occupies an intermediate position between the unequal-sized binaries and those with components of roughly equal sizes. In this work, we predicted and observed three stellar occultation events by Huya. Huya and its satellitewere detected during occultations in 2021 March and again in 2023 June. Additionally, an attempt to detect Huya in 2023 February resulted in an additional single-chord detection of the secondary. A spherical body with a minimum diameter of D = 165 km can explain the three single-chord observations and provide a lower limit for the satellite size. The astrometry of Huya's system, as derived from the occultations and supplemented by observations from the Hubble Space Telescope and Keck Observatory, provided constraints on the satellite orbit and the mass of the system. Therefore, assuming the secondary is in an equatorial orbit around the primary, the limb fitting was constrained by the satellite orbit position angle. The system density, calculated by summing the most precise measurement of Huya's volume to the spherical satellite average volume, is ρ1 = 1073 ± 66 kg m−3. The density that the object would have assuming a Maclaurin equilibrium shape with a rotational period of 6.725 ± 0.01 hr is ρ2 = 768 ± 42 kg m−3. This difference rules out the Maclaurin equilibrium assumption for the main body shape.

Spiral galaxies are ubiquitous in the local Universe. However, the properties of spiral arms in them are still not well studied, and there is even less information concerning spiral structure in distant galaxies. We aim to measure the most general parameters of spiral arms in remote galaxies and trace their changes with redshift. We perform photometric decomposition, including spiral arms, for 159 galaxies from the HST COSMOS and JWST CEERS and JADES surveys, which are imaged in optical and near-infrared rest-frame wavelengths. We confirm that, in our representative sample of spiral galaxies, the pitch angles increase, and the azimuthal lengths decrease with increasing redshift, implying that the spiral structure becomes more tightly wound over time. For the spiral-to-total luminosity ratio and the spiral width-to-disc scale length ratio, we find that band-shifting effects can be as significant as, or even stronger than, evolutionary effects. Additionally, we find that spiral structure becomes more asymmetric at higher redshifts.

The effects of physiologically relevant glucose concentrations on the optical properties of whole blood were measured in-vitro. A concentration increase of +400 mg/dL caused a decrease in the scattering coefficient by 10% over all wavelengths studied. To determine potential mechanisms for the change in the scattering coefficient, we employed optical microscopy to quantify the change in erythrocyte geometry. A 15% change in cell thickness was observed following a glucose increase of +500 mg/dL.

Objective

To investigate the dose-response relationship between dietary sugar and T2D risk.

Methods

MEDLINE, Embase, CINAHL, Web of Science and Cochrane databases were searched through July 9, 2024 for prospective cohorts reporting relative measures of incident T2D risk by categories of dietary sugar (total, free, added, fructose, sucrose) or two beverage sources (non-diet SSB, fruit juice) in healthy adults (Prospero ID: CRD42023401800). Linear and restricted cubic spline dose-response models were fitted for each exposure and study-specific slopes and confidence intervals (CIs) were calculated. Heterogeneity was evaluated using Q-statistics. Risk of bias was evaluated using ROBINS-E tool GRADE approach was applied to assess the certainty of evidence.

Results

Of 10,384 studies, 29 cohorts were included: SSB:18 (n = 541,288); fruit juice:14 (n = 490,413); sucrose: 7 (n = 223,238); total sugar: 4 (n = 109,858); fructose: 5 (n = 158,136); and added sugar: 2 (n = 31,004). Studies were conducted in Europe (13), USA (11), Asia (6), Australia (4), and Latin America (3). Each additional serving of SSB and fruit juice was associated with a higher risk of T2D (RR: 1.25; 95% CI: 1.17–1.35 and RR: 1.05; 95% CI: >1.00–1.11, respectively; moderate certainty). In contrast, 20 g/d intakes of total sugar and sucrose were inversely associated with T2D (RR: 0.96; 95% CI: 0.94–0.98; low certainty; and RR: 0.95; 95% CI: 0.91– <1.00; moderate certainty, respectively). No associations for added sugar (RR: 0.99; 95% CI: 0.96–1.01; low certainty) or fructose (RR: 0.98; 95% CI: 0.83–1.15; very low certainty).

Conclusion

These findings suggest that dietary sugar consumed as a beverage (SSB and fruit juice) is associated with incident T2D risk. The results do not support the common assumption that dietary sugar (i.e., total sugar and sucrose), irrespective of type and amount, is consistently associated with increased T2D risk.