The Texas law prohibiting abortions after a fetal heartbeat could be detected — as early as five or six weeks — went into effect September 1, 2021. At the time, the law — Senate Bill 8, or S.B. 8 — was the most stringent state abortion law in the country. It did not allow exemptions for congenital anomalies.

The researchers’ analysis of monthly death certificate data in Texas and the rest of the United States found that between 2021 and 2022, infant deaths in Texas rose from 1,985 to 2,240, a year-over-year increase of 255 deaths. This corresponds to a 12.9 percent increase in infant deaths in Texas versus a 1.8 percent increase in infant deaths in the rest of the U.S. during the same period. The study defines infants as under 12 months old.

The study was published online June 24 in JAMA Pediatrics.

The findings come as more U.S. states enact stricter abortion laws following the U.S. Supreme Court’s 2022 Dobbs decision, the landmark ruling that overturned Roe v. Wade and returned abortion policymaking to the states.

To approximate the causal impact of S.B. 8, the authors narrowed their analysis to examine changes in the expected number of infant deaths in Texas from March to December 2022 — the time period that captures the first set of pregnancies under S.B. 8. The researchers estimate there were 216 excess infant deaths in Texas that would most likely not have occurred from March to December 2022 had the state’s abortion law not been in place. This is equivalent to a 12.7 percent increase above the expected 1,697 infant deaths for this time period. There were 1,913 observed deaths in Texas from March to December 2022.

An analysis of neonatal deaths — deaths in the first 28 days — found similar patterns, with an estimated 145 excess deaths in the post-policy period. These results were not observed in other states.

The new study is thought to be the first to examine how the Texas abortion ban may have impacted infant deaths in the state and is among the first to present evidence evaluating recent abortion bans and pre-viability restrictions. Prior research has shown that states with more abortion restrictions see more infant deaths than those without. The authors note that these earlier studies evaluate fundamentally different and less severe abortion restrictions and primarily examine correlation.

“Our study is particularly relevant given the June 2022 Dobbs Supreme Court decision that returned abortion lawmaking to states and subsequent rollbacks of reproductive rights in many states,” says Alison Gemmill, PhD, assistant professor in the Bloomberg School’s Department of Population, Family and Reproductive Health and one of the study’s lead authors. “These findings suggest that restrictive abortion policies may have important unintended consequences in terms of infant health and the associated trauma to families and medical costs.”

For their month-by-month causal analysis, the researchers drew from infant death certificates in Texas and 28 comparison states from 2018 through 2022. They excluded the District of Columbia and several states that had fewer than 10 infant deaths in any month from 2018 to 2022, as the exact counts are not provided in currently publicly available data. The researchers selected March 2022 as the first cohort exposed to the Texas abortion policy because these infants, if born full term, would have been approximately 10 to 14 weeks gestation when the Texas law went into effect in September 2021. Before S.B. 8’s enactment, people would have been able to seek termination in the event a fetal issue was detected during screening prior to 20 weeks gestation.

In an analysis of cause of death using all 2021 and 2022 death certificate data, the researchers found that Texas had atypical increases in infant deaths due to congenital anomalies, the leading cause of infant death. Infant deaths attributable to congenital anomalies increased 22.9 percent in Texas between 2021 and 2022 versus a decrease of 3.1 percent in the rest of the U.S. during the same period. Another divergent cause of death pattern in Texas was infant deaths from accidents, which increased by 21 percent in Texas versus a one percent increase in the rest of the U.S.

“Our results suggest that restrictive abortion policies that limit pregnant people’s ability to terminate pregnancies, particularly those with fetal abnormalities diagnosed later in pregnancy, may lead to increases in infant mortality,” says Suzanne Bell, PhD, MPH, assistant professor in the Bloomberg School’s Department of Population, Family and Reproductive Health and one of the study’s lead authors. “These findings make clear the potentially devastating consequences abortion bans can have on pregnant people and families who are unable to overcome barriers to this essential reproductive health service.”

The authors note that the data did not include maternal and clinical characteristics of infant deaths, thus limiting the authors’ ability to explore potential mechanisms behind these findings.

The researchers are currently studying the impact across socioeconomic groups that abortion bans have on live births and infant mortality in Texas and other states that banned abortion following Dobbs.

This study was supported by the Hopkins Population Center from the National Institute of Child Health and Human Development (P2CHD042854).

Exoplanets are abundant in our galaxy. The most common are those between the radius of the Earth (around 6,400 km) and Neptune (around 25,000 km), known as ”sub-Neptunes”. It is estimated that 30% to 50% of sun-like stars contain at least one of these.

Calculating the density of these planets is a scientific challenge. To estimate their density, we must first measure their mass and radius. Problem: planets whose mass is measured by the TTV (Transit-Timing Variation) method are less dense than planets whose mass has been measured by the radial velocity method, the other possible measurement method.

”The TTV method involves measuring variations in transit timing. Gravitational interactions between planets in the same system will slightly modify the moment at which the planets pass in front of their star,” explains Jean-Baptiste Delisle, scientific collaborator in the Astronomy Department of the UNIGE Faculty of Science and co-author of the study. ”The radial velocity method, on the other hand, involves measuring the variations in the star’s velocity induced by the presence of the planet around it”.

Eliminating any bias

An international team led by scientists from NCCR PlanetS, UNIGE and UNIBE has published a study explaining this phenomenon. It is due not to selection or observational biases, but to physical reasons. ”The majority of systems measured by the TTV method are in resonance,” explains Adrien Leleu, assistant professor in the Astronomy Department of the UNIGE Faculty of Science and principal author of the study.

Two planets are in resonance when the ratio between their orbital periods is a rational number. For example, when a planet makes two orbits around its star, another planet makes exactly one. If several planets are in resonance, it forms a chain of Laplace resonances. ”We therefore wondered whether there was an intrinsic connection between density and the resonant orbital configuration of a planetary system,” continues the researcher.

To establish the link between density and resonance, astronomers first had to rule out any bias in the data by rigorously selecting planetary systems for statistical analysis. For example, a large, low-mass planet detected in transit requires more time to be detected in radial velocities. This increases the risk of observations being interrupted before the planet is visible in the radial velocity data, and therefore before its mass is estimated.

”This selection process would lead to a bias in the literature in favor of higher masses and densities for planets characterized with the radial velocity method. As we have no measurement of their masses, the less dense planets would be excluded from our analyses,” explains Adrien Leleu.

Once this data cleaning had been carried out, the astronomers were able to determine, using statistical tests, that the density of sub-Neptunes is lower in resonant systems than their counterparts in non-resonant systems, regardless of the method used to determine their mass.

A question of resonance

The scientists suggest several possible explanations for this link, including the processes involved in the formation of planetary systems. The study’s main hypothesis is that all planetary systems converge towards a resonance chain state in the first few moments of their existence, but only 5% remain stable. The other 95% become unstable. The resonance chain then breaks down, generating a series of ”catastrophes”, such as collisions between planets. The planets fuse together, increasing their density and then stabilizing in non-resonant orbits.

This process generates two very distinct populations of Sub-Neptunes: dense and less dense. ”The numerical models of planetary system formation and evolution that we have developed at Bern over the last two decades reproduce exactly this trend: planets in resonance are less dense. This study, moreover, confirms that most planetary systems have been the site of giant collisions, similar or even more violent than the one that gave rise to our Moon,” concludes Yann Alibert, professor at UNIBE’s Space Research and Planetary Sciences Division (WP) and co-director of the Center for Space and Habitability and co-author of the study.

Researchers led by the University of Cambridge used artificial intelligence techniques to map slush on Antarctic ice shelves, and found that 57% of all meltwater is held in the form of slush, with the remaining amount in surface ponds and lakes.

As the climate warms, more meltwater is formed on the surface of ice shelves, the floating ice surrounding Antarctica which acts as a buttress against glacier ice from inland. Increased meltwater can lead to ice shelf instability or collapse, which in turn leads to sea level rise.

The researchers also found that slush and pooled meltwater leads to 2.8 times more meltwater formation than predicted by standard climate models, since it absorbs more heat from the sun than ice or snow. The results, reported in the journal Nature Geoscience, could have profound implications for ice shelf stability and sea level rise.

Each summer as the weather warms, water pools on the surfaces of Antarctica’s floating ice shelves. Previous research has shown that surface meltwater lakes can contribute to ice shelf fracture and collapse, as the weight of the water can cause the ice to bend or break. However, the role of slush in ice shelf stability is more difficult to determine.

“We can use satellite imagery to map meltwater lakes across much of Antarctica, but it’s hard to map slush, because it looks like other things, such as shadows from clouds, when viewed from a satellite,” said lead author Dr Rebecca Dell from Cambridge’s Scott Polar Research Institute (SPRI). “But using machine learning techniques, we can go beyond what the human eye can see and get a clearer picture of how slush might be affecting ice in Antarctica.”

Using optical data from NASA’s Landsat 8 satellite, the Cambridge researchers, working with researchers from the University of Colorado Boulder and the Delft University of Technology, trained a machine learning model to obtain monthly records of slush and meltwater lakes across 57 Antarctic ice shelves between 2013 and 2021.

“Machine learning allows us to use more information from the satellite, since it can work with more wavelengths of light than the human eye can see,” said Dell. “This allows us to determine what is and isn’t slush, and then we can train the machine learning model to quickly identify it across the whole continent.”

“We’re interested in learning how much slush is present during the Antarctic summer, and how it’s changed over time,” said co-author Professor Ian Willis, also from SPRI.

Using their machine learning model, the researchers found that in the peak of the Antarctic summer in January, over half (57%) of all meltwater on Antarctica’s ice shelves is held in slush, with the remaining 43% in meltwater lakes.

“This slush has never been mapped on a large scale across all of Antarctica’s large ice shelves, so over half of all surface meltwater has been ignored until now,” said Dell. “This is potentially significant for the hydrofracture process, where the weight of meltwater can create or enlarge fractures in the ice.”

Meltwater affects the stability of the floating ice shelves that fringe the Antarctic coastline. As the climate warms and melt rates in Antarctica increase, meltwater — whether in the form of lakes or slush — can get into cracks on the ice, causing the cracks to get bigger. This can cause fractures in the ice shelf, and could cause vulnerable ice shelves to collapse, which in turn would allow inland glacier ice to spill into the ocean and contribute to sea level rise.

“Since slush is more solid than meltwater, it won’t cause hydrofracture in the same way that water from a lake does, but it’s definitely something we need to consider when attempting to predict how or whether ice shelves will collapse,” said Willis.

In addition to the potential implications of slush on hydrofracture, it also has a large effect on melt rates. Since slush and lakes are less white than snow or ice, they absorb more heat from the sun, causing more snowmelt. This extra melt is currently unaccounted for in climate models, which may lead to underestimates in projections of ice sheet melting and ice shelf stability.

“I was surprised that this meltwater was so poorly accounted for in climate models,” said Dell. “Our job as scientists is to reduce uncertainty, so we always want to improve our models so they are as accurate as possible.”

“In future, it’s likely that places in Antarctica that currently don’t have any water or slush will start to change,” said Willis. “As the climate continues to warm, more melting will occur, which could have implications for ice stability and sea level rise.”

The research was supported in part by the European Space Agency and the Natural Environment Research Council (NERC), part of UK Research and Innovation (UKRI). Rebecca Dell is a Fellow of Trinity Hall, Cambridge.