Immune Function Effects of Dental Amalgam in Children: A Randomized Clinical Trial

Background Dental amalgam is a widely used restorative material containing 50% elemental mercury that emits mercury vapor. No randomized clinical trials have determined whether there are adverse immunologic effects associated with this low-level mercury exposure in children. The objective of this study was to evaluate a sub-population of the New England Children’s Amalgam Trial (NECAT) for in vitro manifestations of immunotoxic effects of dental amalgam. Methods A randomized clinical trial in which children requiring dental restorative treatment were randomized to either amalgam for posterior restorations or resin composite. A total of 66 children, aged 6–10 years, were assessed for total white cell numbers, T-cell, B-cell, neutrophil and monocyte responsiveness over a five-year period. Owing to the small number of participants, the study is exploratory in nature with limited statistical power. Results The mean number of tooth surfaces restored during the five-year period was 7.8 for the amalgam group and 10.1 for composite group. In the amalgam group there was a slight, but not statistically significant, decline in responsiveness of T-cells and monocytes at 5–7 days post treatment; no differences were consistently observed at 6, 12 or 60 months. Conclusions This study confirms that treatment of children with dental amalgams leads to increased, albeit low level, exposure to mercury. In this exploratory analysis of immune function, amalgam exposure did not cause overt immune deficits, although small transient effects were observed 5–7 days post restoration. Clinical implications These findings suggest that immunotoxic effects of amalgam restorations in children need not be a concern when choosing this restorative dental material

Spatial aspects of the reproductive and feeding biology of the striped robber, Brycinus lateralis (Pisces: Characidae), in the Okavango Delta, Botswana

The Okavango Delta is a vast inland wetland system situated in northern Botswana. High rainfall is received in early summer in the southern Angolan highlands and throughout the Delta with the flood waters reaching the upper riverine floodplain between March and May where it percolates through to the lower drainage rivers between July and September. Aspects of the reproductive and feeding biology of two allopatric populations of the striped robber, Brycinus lateralis, a small characin species inhabiting the northern riverine floodplain and southern drainage rivers, were investigated. Both populations were similar in the biological aspects studied, with the flood cycle having little influence on the timing of reproduction, sexual maturity and dietary composition. Female fish from both populations matured sexually at 57mmSL, breeding over a protracted period during the warm, summer months. In both populations, the sex ratio was female-dominated at 4.8:1 (riverine floodplain) and 2.2:1 (drainage rivers). The striped robber is an opportunistic micro-carnivore with immature fish feeding predominantly on Daphnia spp. and adults being largely insectivorous

High-coverage genomes to elucidate the evolution of penguins

Background: Penguins (Sphenisciformes) are a remarkable order of flightless wing-propelled diving seabirds distributed widely across the southern hemisphere. They share a volant common ancestor with Procellariiformes close to the Cretaceous-Paleogene boundary (66 million years ago) and subsequently lost the ability to fly but enhanced their diving capabilities. With ∼20 species among 6 genera, penguins range from the tropical Galápagos Islands to the oceanic temperate forests of New Zealand, the rocky coastlines of the sub-Antarctic islands, and the sea ice around Antarctica. To inhabit such diverse and extreme environments, penguins evolved many physiological and morphological adaptations. However, they are also highly sensitive to climate change. Therefore, penguins provide an exciting target system for understanding the evolutionary processes of speciation, adaptation, and demography. Genomic data are an emerging resource for addressing questions about such processes. Results: Here we present a novel dataset of 19 high-coverage genomes that, together with 2 previously published genomes, encompass all extant penguin species. We also present a well-supported phylogeny to clarify the relationships among penguins. In contrast to recent studies, our results demonstrate that the genus Aptenodytes is basal and sister to all other extant penguin genera, providing intriguing new insights into the adaptation of penguins to Antarctica. As such, our dataset provides a novel resource for understanding the evolutionary history of penguins as a clade, as well as the fine-scale relationships of individual penguin lineages. Against this background, we introduce a major consortium of international scientists dedicated to studying these genomes. Moreover, we highlight emerging issues regarding ensuring legal and respectful indigenous consultation, particularly for genomic data originating from New Zealand Taonga species. Conclusions: We believe that our dataset and project will be important for understanding evolution, increasing cultural heritage and guiding the conservation of this iconic southern hemisphere species assemblage.Fil: Pan, Hailin. Bgi-shenzhen; ChinaFil: Cole, Theresa L. University Of Otago; CanadáFil: Bi, Xupeng. Bgi-shenzhen; ChinaFil: Fang, Miaoquan. Bgi-shenzhen; ChinaFil: Zhou, Chengran. Bgi-shenzhen; ChinaFil: Yang, Zhengtao. Bgi-shenzhen; ChinaFil: Ksepka, Daniel T. Bruce Museum; Estados UnidosFil: Hart, Tom. University of Oxford; Reino UnidoFil: Bouzat, Juan L.. Bowling Green State University; Estados UnidosFil: Boersma, P. Dee. University of Washington; Estados UnidosFil: Bost, Charles-André. Centre Detudes Biologiques de Chizé; FranciaFil: Cherel, Yves. Centre Detudes Biologiques de Chizé; FranciaFil: Dann, Peter. Phillip Island Nature Parks; AustraliaFil: Mattern, Thomas. University of Otago; Nueva ZelandaFil: Ellenberg, Ursula. Global Penguin Society; Estados Unidos. La Trobe University; AustraliaFil: Garcia Borboroglu, Jorge Pablo. University of Washington; Estados Unidos. Global Penguin Society; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Argilla, Lisa S.. Otago Polytechnic; Nueva ZelandaFil: Bertelsen, Mads F.. Copenhagen Zoo; Dinamarca. University of Copenhagen; DinamarcaFil: Fiddaman, Steven R.. University of Oxford; Reino UnidoFil: Howard, Pauline. Hornby Veterinary Centre; Nueva Zelanda. South Island Wildlife Hospital; Nueva ZelandaFil: Labuschagne, Kim. National Zoological Garden; SudáfricaFil: Miller, Gary. University of Western Australia; Australia. University of Tasmania; AustraliaFil: Parker, Patricia. University of Missouri St. Louis; Estados UnidosFil: Phillips, Richard A.. Natural Environment Research Council; Reino UnidoFil: Quillfeldt, Petra. Justus-Liebig-Universit ̈ at Giessen; AlemaniaFil: Ryan, Peter G.. University of Cape Town; SudáfricaFil: Taylor, Helen. Vet Services Hawkes Bay Ltd; Nueva Zelanda. Wairoa Farm Vets; Nueva ZelandaFil: Zhang, De-Xing. Chinese Academy of Sciences; República de ChinaFil: Zhang, Guojie. BGI-Shenzhen; China. Chinese Academy of Sciences; República de China. University of Copenhagen; DinamarcaFil: McKinlay, Bruce. Department of Conservation; Nueva Zeland

Notes on the distribution, ecology, and life history of Maotoweta virescens (Orthoptera, Rhaphidophoridae, Macropathinae) and a comparison of two survey methods

When described in 2014, Maotoweta virescens was believed to be one of New Zealand’s rarest cave wētā (Rhaphidophoridae). Here, we present new information about the distribution, ecology, and life history of the species. M. virescens has now been recorded from indigenous forest sites throughout the length of the western South Island, where it can occur in relatively high abundance. M. virescens shows a close association with arboreal mosses, particularly Weymouthia mollis, roosting within them during the day and feeding on them at night. The wētā has also been documented feeding on lichens and dead insects. The species is hypothesized to have a lifecycle of approximately one year, closely linked to season. Eggs are thought to hatch out relatively quickly after being laid in summer and early autumn, with the species overwintering as nymphs and maturing the following late spring through to early-autumn. Further work is required to fully understand its biology. A comparison was made between active night searching and vegetation beating as two different methods for the detection and monitoring of M. virescens. Beating of W. mollis and other suitable M. virescens microhabitats was found to be significantly more effective than night searching. Our results show that M. virescens is widespread and can occur at relatively high densities within South Island temperate forests, with the species’ perceived rarity to date largely owing to a lack of survey effort and the past use of ineffective sampling methods