Radiocarbon re-dating of contact-era Iroquoian history in northeastern North America

A time frame for late Iroquoian prehistory is firmly established on the basis of the presence/absence of European trade goods and other archeological indicators. However, independent dating evidence is lacking. We use 86 radiocarbon measurements to test and (re)define existing chronological understanding. Warminster, often associated with Cahiagué visited by S. de Champlain in 1615–1616 CE, yields a compatible radiocarbon-based age. However, a well-known late prehistoric site sequence in southern Ontario, Draper-Spang-Mantle, usually dated ~1450–1550, yields much later radiocarbon-based dates of ~1530–1615. The revised time frame dramatically rewrites 16th-century contact-era history in this region. Key processes of violent conflict, community coalescence, and the introduction of European goods all happened much later and more rapidly than previously assumed. Our results suggest the need to reconsider current understandings of contact-era dynamics across northeastern North America

The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R ⊕ to 1.6 R ⊕. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V = 11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system

Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.

Telomere length is a risk factor in disease and the dynamics of telomere length are crucial to our understanding of cell replication and vitality. The proliferation of whole genome sequencing represents an unprecedented opportunity to glean new insights into telomere biology on a previously unimaginable scale. To this end, a number of approaches for estimating telomere length from whole-genome sequencing data have been proposed. Here we present Telomerecat, a novel approach to the estimation of telomere length. Previous methods have been dependent on the number of telomeres present in a cell being known, which may be problematic when analysing aneuploid cancer data and non-human samples. Telomerecat is designed to be agnostic to the number of telomeres present, making it suited for the purpose of estimating telomere length in cancer studies. Telomerecat also accounts for interstitial telomeric reads and presents a novel approach to dealing with sequencing errors. We show that Telomerecat performs well at telomere length estimation when compared to leading experimental and computational methods. Furthermore, we show that it detects expected patterns in longitudinal data, repeated measurements, and cross-species comparisons. We also apply the method to a cancer cell data, uncovering an interesting relationship with the underlying telomerase genotype

Publisher Correction: Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper

An Overview of the Penguin Visual System

Penguins require vision that is adequate for both subaerial and submarine environments under a wide range of illumination. Here we provide a structured overview of what is known about their visual system with an emphasis on how and how well they achieve these goals. Amphibious vision is facilitated by a relatively flat cornea, the power in air varying from 10.2 dioptres (D) to 41.3 D depending on the species, and there is good evidence for emmetropia both above and below water. All penguins are trichromats with loss of rhodopsin 2, a nocturnal feature, but only deeper diving penguins have been noted to have pale oil droplets and a preponderance of rods. Conversely, the diurnal, shallow-diving little penguin has a higher ganglion cell density (28,867 cells/mm2) and f-number (3.5) than those that operate in dimmer light. In most species studied, there is some binocular overlap, but this reduces upon submergence. However, gaps in our knowledge remain, particularly with regard to the mechanism of accommodation, spectral transmission, behavioural measurements of visual function in low light, and neural adaptations to low light. The rarer species also deserve more attention

Confocal and Electron Microscopic Structure of the Cornea from Three Species of Penguin

Corneal confocal microscopy has not previously been performed in penguins, despite recognition of its unusually flat shape. To identify features that the penguin shares with other birds and or mammals and those specific to penguins, we undertook confocal microscopic examination of two little (Eudyptula minor), four gentoo (Pygoscelis papua) and five king (Aptenodytes patagonicus) penguin corneas. Transmission electron microscopy was performed on one gentoo and one king penguin, for finer details. Features shared with other higher vertebrates included a five-layered cornea and a similar limbus. Typically avian were a lower density of stromal cells, a more regular arrangement of collagen bands and an absent basal nerve plexus. Features unique to penguins included a flattened superficial epithelium (king penguin), stromal myofibroblasts (all) and an irregular endothelium (little penguin). Other features uniquely identified by confocal microscopy in birds include epithelial and stromal nerves, guttata and stromal imprints on Descemet’s membrane. Transmission electron microscopy identified a lack of wing cells (king penguin), greater posterior collagen lamellae thickness (gentoo penguin) and significantly less interlacing of collagen lamellae in the central cornea (king and gentoo). Most of these unique features are yet to be explained, but some could be adaptations to diving

Mutually attracted or repulsed? : actor-partner interdependence models of Dark Triad traits and relationship outcomes

Although the Dark Triad traits - narcissism, Machiavellianism, and psychopathy - have been studied in individuals, little is known about their roles in dating relationships. Forty-five heterosexual undergraduate couples (N= 90) reported measures of the Dark Triad and relationship commitment and satisfaction. Within couples, assortative mating was slightly negative for narcissism, marginally positive for Machiavellianism, and significantly positive for psychopathy. Using actor-partner interdependence models, we explored the extent to which satisfaction mediated the direct associations between the Dark Triad and commitment. Men's satisfaction marginally mediated the women's Dark Triad. →. men's commitment negative association. Among the three Dark Triad subscales, satisfaction marginally mediated both of the actor-effect-based psychopathy. →. commitment negative associations. We discuss possible implications for couples' relationship strategies