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As mass bleaching events decimate stony coral populations, production of calcium carbonate is diminished on reefs, dampening their capacity to keep pace with rising sea levels. However, perturbations to the calcification process of surviving wild corals during bleaching are poorly constrained, owing to the lack of suitable techniques to retroactively extract this information from coral skeletons at sufficient resolution. Here, we use novel Raman spectrometry techniques to test the biogeochemical response of long‐lived corals before, during, and after bleaching. Maintenance of high aragonite saturation state (Ω_Ar) in the coral calcifying fluid is key to driving rapid skeletal growth but would be expected to decrease when corals become energetically depleted without their symbionts. Contrary to this expectation, our results demonstrate that corals upregulate calcifying fluid Ω_Arduring bleaching and for at least 2 yr after recovery. This indicates that the calcification process of coral‐bleaching survivors is unexpectedly resilient.

 

Previous research examining toddler sleep problems has relied almost exclusively on variable-centered statistical approaches to analyze these data, which provide helpful information about the development of the average child. The current study examined whether person-centered trajectory analysis, a statistical technique that can identify subgroups of children who differ in their initial level and/or trajectory of sleep problems, has the potential to inform our understanding of toddler sleep problems and their development.

Families (N = 185) were assessed at 12, 24, 30, and 36 months of child age. Latent class growth analysis was used to test for subgroups that differed in their 24–36 month sleep problems. Subgroups were compared on child 36-month externalizing, internalizing, and total problem behaviors, and on 12 month maternal mental health, inter-parental conflict, and maternal parenting behaviors.

Results support a four-class solution, with “low, stable,” “low, increasing,” “high, increasing,” and “high decreasing” classes. The classes whose sleep problems persisted or worsened over time had worse behavioral problems than those whose symptoms improved or remained stably low. Additionally, 12 month maternal depression and global symptom severity, intimate partner violence, and maternal harsh-intrusive parenting behaviors discriminated between the classes that had similar levels of 24 month sleep disturbance but who had diverging trajectories over time.

This statistical approach appears to have the potential to increase understanding of sleep problem trajectories in the early years of life. Maternal mental health, intimate partner violence, and parenting behaviors may be clinically useful markers of risk for the persistence or development of toddler sleep problems.

 

Redox-active metal–organic frameworks (MOFs) are promising materials for a number of next-generation technologies, and recent work has shown that redox manipulation can dramatically enhance electrical conductivity in MOFs. However, ligand-based strategies for controlling conductivity remain under-developed, particularly those that make use of reversible redox processes. Here we report the first use of ligand n-doping to engender electrical conductivity in a porous 3D MOF, leading to tunable conductivity values that span over six orders of magnitude. Moreover, this work represents the first example of redox switching leading to reversible conductivity changes in a 3D MOF. 

Exposure to higher levels of sociodemographic risk is associated with lower levels of academic achievement among young children. However, there is variability in the strength of this association, which may be traced to individual differences in physiological processes underlying self‐regulation. In the current study, we examined whether the response of the parasympathetic nervous system to challenge, indexed by change in respiratory sinus arrhythmia (RSA), moderated the association between risk and school readiness at 5 years of age in a diverse sample of young children. We found that parasympathetic response to the Still‐Face Paradigm moderated the effects of risk on a measure of school readiness, such that there was no association between risk and school readiness among children who exhibited RSA decreases during challenge at 6 months of age, a purported index of self‐regulation at this age. For those infants who did not exhibit RSA withdrawal during this challenge, exposure to early cumulative risk was associated with lower scores on achievement assessment. These results speak to the possibility that certain patterns of parasympathetic response can serve as a protective factor for young children growing up in disadvantaged environments.

 

Gravitational lensing by massive objects along the line of sight to the source causes distortions to gravitational wave (GW) signals; such distortions may reveal information about fundamental physics, cosmology, and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO-Virgo network. We search for repeated signals from strong lensing by (1) performing targeted searches for subthreshold signals, (2) calculating the degree of overlap among the intrinsic parameters and sky location of pairs of signals, (3) comparing the similarities of the spectrograms among pairs of signals, and (4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by (1) frequency-independent phase shifts in strongly lensed images, and (2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the nondetection of GW lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.

 

We report the observation of a coalescing compact binary with component masses 2.5–4.5M_⊙and 1.2–2.0M_⊙(all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5M_⊙at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of${55}_{-47}^{+127}{\mathrm{Gpc}}^{-3}{\mathrm{yr}}^{-1}$for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star–black hole merger, GW230529_181500-like sources may make up the majority of neutron star–black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star–black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap.

 

We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers.