Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog – Page 10103

Evolutionary theory predicts that reproduction entails costs that detract from somatic maintenance, accelerating biological aging. Despite support from studies in human and non-human animals, mechanisms linking ‘costs of reproduction’ (CoR) to aging are poorly understood. Human pregnancy is characterized by major alterations in metabolic regulation, oxidative stress, and immune cell proliferation. We hypothesized that these adaptations could accelerate blood-derived cellular aging. To test this hypothesis, we examined gravidity in relation to telomere length (TL, n = 821) and DNA-methylation age (DNAmAge, n = 397) in a cohort of young (20–22 year-old) Filipino women. Age-corrected TL and accelerated DNAmAge both predict age-related morbidity and mortality, and provide markers of mitotic and non-mitotic cellular aging, respectively. Consistent with theoretical predictions, TL decreased (p = 0.031) and DNAmAge increased (p = 0.007) with gravidity, a relationship that was not contingent upon resource availability. Neither biomarker was associated with subsequent fertility (both p 0.3), broadly consistent with a causal effect of gravidity on cellular aging. Our findings provide evidence that reproduction in women carries costs in the form of accelerated aging through two independent cellular pathways.

Read more

One of the biggest challenges for astronomers searching for habitable exoplanets is trying to match up newly discovered worlds with the increasingly long list of criteria that we believe are required for life to take root. A planet may be at a reasonable distance from its host star, but if that star is too young or too old, or just the wrong type, life as we know it would have a hard time there. Now, researchers are reporting the existence of several new planets that appear to meet all the requirements.

The research, which was conducted by scientists from the University of Cambridge and the Medical Research Council Laboratory of Molecular Biology, focuses on planets that are at a safe distance from their host star, but that are also getting enough UV light to trigger the chemical reactions that serve as the foundation for life to exist.

The researchers involved with the study used data from previous experiments that demonstrated the conditions under which the building blocks of life may have formed. Chemicals produced as a result of carbon-rich meteorites slamming into the early Earth are thought to have been a precursor for life, but the scientists still needed to account for the role that the sun played.

Read more

You may know graphene as a pseudo-legendary substance that could potentially revolutionize science and space travel and all sorts of things. If you don’t, you should get educated is pretty ridiculous. Simply made from carbon arranged into perfect one atom thing sheets makes the material one of the strongest ever observed. And, now, researchers at Rice University have found that so-called “rebar” graphene is dramatically tougher.

Graphene is much stronger than steel. In fact, an elephant could stand on a pencil and that pressure couldn’t break through a thin sheet of the material. But, because it is arranged in sheets, it can still be ripped if damaged from the right angle. But the researchers figured that reinforcing the structure, as we do with steel bars in concrete structures, l could help prevent damage.

The new research, published in the ACS Nano, a journal run by the American Chemical Society, Rice materials scientist Jun Lou and lead author Emily Hacopian examined the properties of rebar graphene under stress. Cracked and tears in the structure that otherwise would have spread across the sheet are stopped by the reinforcement while also staying stretchy and pliable.

Read more

Cuprate superconductors have many unusual properties even in the “normal” (nonsuperconducting) regions of their phase diagram. In the so-called “strange metal” phase, these materials have resistivity that scales linearly with temperature, in contrast to the usual quadratic dependence of ordinary metals. Giraldo-Gallo et al. now find that at very high magnetic fields—up to 80 tesla—the resistivity of the thin films of a lanthanum-based cuprate scales linearly with magnetic field as well, again in contrast to the expected quadratic law. This dual linear dependence presents a challenge for theories of the normal state of the cuprates.

Science, this issue p. 479

The anomalous metallic state in the high-temperature superconducting cuprates is masked by superconductivity near a quantum critical point. Applying high magnetic fields to suppress superconductivity has enabled detailed studies of the normal state, yet the direct effect of strong magnetic fields on the metallic state is poorly understood. We report the high-field magnetoresistance of thin-film La2–xSrxCuO4 cuprate in the vicinity of the critical doping, 0.161 ≤ p ≤ 0.190. We find that the metallic state exposed by suppressing superconductivity is characterized by magnetoresistance that is linear in magnetic fields up to 80 tesla. The magnitude of the linear-in-field resistivity mirrors the magnitude and doping evolution of the well-known linear-in-temperature resistivity that has been associated with quantum criticality in high-temperature superconductors.

Read more