Decreased Anti-Inflammatory Responses to Vitamin D in Neonatal Neutrophils

Neutrophil activity is prolonged in newborns, suggesting decreased exposure and/or responses to immunosuppressive modulators, such as 1,25-hydroxyvitamin D3 (1,25-vit D3). We hypothesized that 1,25-vit D3 suppresses neutrophil activation and that this response is impaired in newborns. Consistent with this, 1,25-vit D3 decreased LPS-induced expression of macrophage inflammatory protein-1β and VEGF in adult, but not neonatal, neutrophils. Expression of vitamin D receptor (VDR) and 25-hydroxyvitamin D3-1α-hydroxylase was reduced in neonatal, relative to adult neutrophils. Moreover, 1,25-vit D3 induced VDR gene expression in activated adult, but not neonatal, neutrophils. 1,25-vit D3 also suppressed expression of cyclooxygenase-2 and induced expression of 5-lipoxygenase in LPS-exposed adult neutrophils, while neonatal cells were not affected. 1,25-vit D3 had no effect on respiratory burst in either adult or neonatal cells. Anti-inflammatory activity of vitamin D is impaired in neonatal neutrophils, and this may be due to decreased expression of VDR and 1α-hydroxylase. Insensitivity to 1,25-vit D3 may contribute to chronic inflammation in neonates

Stable isotope ecology of Cape dune mole-rats (Bathyergus suillus) from Elandsfontein, South Africa: implications for C4 vegetation and hominin paleobiology in the Cape Floral Region

The archaeological and paleontological records from the west coast of South Africa have potential to provide insights into ecosystem dynamics in the region during the mid Pleistocene. Although the fossil record suggests an ecosystem quite different than that of the region today, we understand little about the ecological factors that contributed to this disparity. The site of Elandsfontein (EFT) dates to between 1.0 and 0.6 million years ago (Ma), preserves in situ lithic and faunal materials found in direct association with each other, and provides the rare opportunity to examine the relationship between hominin behavioural variability and landscape heterogeneity in a winter rainfall ecosystem. In this study, we examine the stable carbon isotopic composition of a large sample (n = 81) of Cape dune mole-rats (Bathyergus suillus) and contemporaneous large mammals (> 6 kg; n = 194) from EFT. We find that δ13C values of B. suillus are significantly different to those of contemporaneous large mammals from EFT indicating a significant presence of plants utilizing the C4 photosynthetic pathway during the mid-Pleistocene, in contrast to present C3 dominated ecosystems along the west coast of South Africa. Additionally, we find that artifact density at EFT localities is positively correlated with δ13C values in B. suillus enamel suggesting that evidence of more intense hominin occupation may be associated with the presence of more C4 vegetation. Lastly, we hypothesize that this unique distribution of vegetation 1) provided abundant resources for both hominin and non-hominin taxa and 2) may have concentrated hominin and animal behavior in certain places on the ancient landscape

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea)

Seasonal two-way migration is an ecological phenomenon observed in a wide range of large-bodied placental mammals, but is conspicuously absent in all modern marsupials. Most extant marsupials are typically smaller in body size in comparison to their migratory placental cousins, possibly limiting their potential to undertake long-distance seasonal migrations. But what about earlier, now-extinct giant marsupial megafauna? Here we present new geochemical analyses which show that the largest of the extinct marsupial herbivores, the enormous wombat-like Diprotodon optatum, undertook seasonal, two-way latitudinal migration in eastern Sahul (Pleistocene Australia-New Guinea). Our data infer that this giant marsupial had the potential to perform round-trip journeys of as much as 200 km annually, which is reminiscent of modern East African mammal migrations. These findings provide, to our knowledge, the first evidence for repetitive seasonal migration in any metatherian (including marsupials), living or extinct, and point to an ecological phenomenon absent from the continent since the Late Pleistocene

Reply to Brook et al: No empirical evidence for human overkill of megafauna in Sahul

We welcome comments by Brook et al. (1), supporters of human-driven models, on our review of the role of climate in Pleistocene faunal extinctions in Sahul (Pleistocene Australia–New Guinea) (2). In response, we begin on a point of agreement: the fossil fauna record on which our respective arguments are based is sparse, although our understanding of Pleistocene environmental conditions is improving (3⇓–5). However, we also flag a basic point of difference. Unlike Brook et al., who focus on the ∼50 extinct Australian species (an artificial distinction because Australia was part of the larger landmass Sahul) and the 50 ka since human arrival, we consider the bigger picture, and the 88 large taxa that disappeared from Sahul from ∼450 ka