Search

Although many glaciers in the Cordillera Darwin Icefield calve into fjords or lakes, the icefield’s evolution is largely controlled by atmospheric conditions. Over the recent two decades surface melt has increased significantly due to rising air temperatures.

Discovery of a nearly complete skeleton of Huayracursor jaguensis, a Carnian dinosaur from the Northern Precordillera Basin in northwestern Argentina provides evidence of increased body size and early cervical elongation during the Late Triassic epoch.

Previous studies suggest that rates of gorge formation are controlled by bedrock erodibility, erosion mechanism and hillslope processes. Here, the authors show evidence of rapid gorge formation in granite bedrock and report no relationship with flood size or bedload, attributing the rate to pre-existing jointing.

It is postulated that the Patagonian steppe evolved purely as a consequence of Andean uplift 15 million years ago, yet direct evidence is lacking. Palazzesi et al.present a bioclimatic analysis of pollen assemblages and show that Patagonian desertification began much more recently than previously thought.

A previously unsampled deep lineage in central Argentina was discovered that had distinctive genetic drift by 8,500 bp and persisted as the main Native American ancestry component in the region up to the present day.

A streamlined blood test using mass spectrometry improves measurement of amyloid-β for early Alzheimer’s disease diagnosis, requiring less sample volume and reagents while maintaining high accuracy, sensitivity and strong agreement with brain imaging.

Repeated evolution provides valuable insight into adaptation. In this study, the authors found that repeated evolution of cave-adapted phenotypes of a fish (Astyanax mexicanus) was driven by selection on standing genetic variation and novel mutations and genes repeatedly under selection are longer compared to the rest of the genome.

Analysis combining multiple global tree databases reveals that whether a location is invaded by non-native tree species depends on anthropogenic factors, but the severity of the invasion depends on the native species diversity.

How Indigenous populations in the southern tip of South America have changed over time has been unclear. Here the authors generate genome-wide data for 20 ancient individuals and examine how past migrations and admixture events correlate to geography and shifts in the archaeological record.

This study provides a comprehensive characterization of blue C for South American Atlantic salt marshes and reveals that environmental and biological variables are important for an understanding of blue C storage leading to lower global estimates.

Cretaceous amber from the Ecuadorian Napo region provides exceptional evidence of a resinous forest ecosystem and diverse arthropod fauna in equatorial Gondwana, as revealed by integrated analyses of amber geochemistry and bioinclusions, palynology, and associated macrofloras.

The authors report a trial subset analysis of the immune responses induced by two inactivated quadrivalent influenza vaccines (QIVs): Sinovac QIV and Vaxigrip-Tetra™. Both vaccines elicit robust humoral responses and distinct T cell profiles.

Using lidar over an area of 85,000 km², Inomata et al. identified 478 early ceremonial complexes in southern Mexico. These discoveries offer new information for understanding the origins of Mayan civilization and its relation with the Olmecs.

Hechenleitner et al. describe two new titanosaurians and the finding of numerous accumulations of titanosaurian eggs in La Rioja, Argentina. This study suggests nesting site philopatry among Titanosauria and that this clade was spread throughout southern South America at the end of the Late Cretaceous.

The 2023 monkeypox outbreak was caused by a subclade IIb monkeypox virus (MPXV). Here, using advanced sequencing techniques, the authors identify variations on low-complexity regions of the MPXV genome and describe their potential as evolutionary drivers.

Archaeological evidence that anthropic landscape changes and crop cultivation in southwestern Amazonia began about 10,000–11,000 years ago confirms that the region is a centre of early plant domestication.

De Solis and Del Río-Martín et al. investigate the reciprocal interplay between AgRP and POMC neurocircuits that governs the precise regulation of food intake and systemic metabolic homeostasis.

An analysis of 24,202 critical cases of COVID-19 identifies potentially druggable targets in inflammatory signalling (JAK1), monocyte–macrophage activation and endothelial permeability (PDE4A), immunometabolism (SLC2A5 and AK5), and host factors required for viral entry and replication (TMPRSS2 and RAB2A).

Analysis of 20 chemical and morphological plant traits at diverse sites across 6 continents shows that the transition from semi-arid to arid zones is associated with an unexpected 88% increase in trait diversity.

Clarke et al. identify chromatin factor ZNF280A, which is recruited to damaged chromatin where it promotes long-range DNA-end resection. Loss of ZNF280A is linked to genome instability in patients with 22q11.2 distal deletion syndrome.

While integrin-based adhesions are thought to underlie many aspects of cell response to localized tension, another matrix receptor, syndecan-4, has now been shown to act as a mechanosensor, which triggers cell-wide integrin activation and adhesion reinforcement.

A comparison of alpha diversity (number of plant species) and dark diversity (species that are currently absent from a site despite being ecologically suitable) demonstrates the negative effects of regional-scale anthropogenic activity on plant diversity.

Microglia can help clear amyloid β plaques in the Alzheimer’s disease brain but may also become dysfunctional and can contribute to disease progression. March-Diaz et al. reveal that hypoxia, a potentially modifiable risk factor for Alzheimer’s disease, disrupts the metabolism and function of microglia near plaques, which may contribute to neuropathology.

Obstructive sleep apnea (OSA) is a highly prevalent condition with a number of comorbidities, but it has a high misdiagnosis rate. In this retrospective study, the authors used six independent databases to develop and evaluate a deep learning model, denoted OxiNet, for the diagnosis of OSA from the sole oximetry signal.

Modern crocodylian diversity is in decline and sympatry is rare, with usually no more than two or three species occurring in the same geographic area. Here Scheyer et al. identify a diversity peak in sympatric occurrence of at least seven new and previously characterized crocodylian species during the Miocene in South America.

Wood density is an important plant trait. Data from 1.1 million forest inventory plots and 10,703 tree species show a latitudinal gradient in wood density, with temperature and soil moisture explaining variation at the global scale and disturbance also having a role at the local level.

Multisystem inflammatory syndrome following SARS-CoV-2 infection results from increased serum levels of TGFβ, which impairs the reactivation of virus-specific T cells.