1366 research outputs found
Sort by
Sulfur-enhanced reductive bioprocessing of cobalt-bearing materials for base metals recovery
Get PDFThe abundance of limonitic laterite ores in tropical and sub-tropical areas represents a large, and mostly unexploited, cobalt resource. Bioprocessing oxidised ores, and also waste materials such as tailings and processing residues, using acidophilic microorganisms to catalyse the reductive dissolution of iron and manganese minerals, is an environmentally benign alternative approach of extracting valuable base metals associated with these deposits. This work describes results from laboratory-scale experiments in which five cobalt-bearing materials, three primary limonitic laterite ores and two processing residues (filter dust and slag), all sourced from mines and a processing plant in Greece, were bioleached under reducing conditions by a consortium of acidophilic bacteria (using elemental sulfur as electron donor) in stirred tank bioreactors at pH 1.5 and 35 °C. Whilst the target metal, cobalt, was successfully bioleached from all five materials (40–50% within 30 days) the extraction of some other metals was more variable (e.g. between 2 and 48% of iron). Concentrations of soluble cobalt were highly correlated, in most cases, with those of manganese, in agreement with the finding that cobalt was primarily deported in manganese (IV) minerals. Acid consumption also differed greatly between mineral samples, ranging between 3 and 67 moles H2SO4 g−1 cobalt extracted. Comprehensive mineralogical analysis of the three limonitic samples before and after bioprocessing revealed significant variations between the ores, and demonstrated that elemental and mineralogical variabilities can greatly impact their amenability for reductive bioleaching.Copyright: © 2020 Elsevier B.V. All rights reserved. The attached file is the published version of the article.NHM Repositor
Long-term stability in the volume of Atlantic Puffin (Fratercula arctica) eggs in the western North Atlantic
Get PDFIn the eastern North Atlantic, declines in the volume of Atlantic Puffin (Fratercula arctica (Linnaeus, 1758)) eggs have been associated with shifts in the marine ecosystem, such as changes in the abundance of forage fishes and increasing sea-surface temperatures. In the western North Atlantic, where similar shifts in oceanographic conditions and changes in the abundance of forage fishes have presumably occurred, trends in the volume of Atlantic Puffin eggs remain unknown. In this study, we investigate Atlantic Puffin egg volume in the western North Atlantic. We compiled 140 years (1877–2016) of egg volume measurements (n = 1805) and used general additive mixed-effects models to investigate temporal trends and regional variation. Our findings indicate that Atlantic Puffin egg volume differs regionally but has remained unchanged temporally in the western North Atlantic since at least the 1980s.Copyright © 2021, The Authors. This document is the author’s final accepted version of the journal article. You are advised to consult the published version if you wish to cite from it.NHM Repositor
Tracking the impacts of COVID-19 pandemic-related debris on wildlife using digital platforms
Get PDFSince the start of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; COVID-19) pandemic in December 2019, there have been global surges of single-use plastic use. Due to the importance of personal protective equipment (PPE) and sanitation items in protecting against virus transmission and from testing, facemasks, respirators, disposable gloves and disposable wet wipes have become global staples in households and institutions. Widespread use and insufficient infrastructure, combined with improper waste management have resulted in an emerging category of litter. With widespread presence in the environment, such items pose a direct threat to wildlife as animals can interact with them in a series of ways. We examined the scope of COVID-19 pandemic-related debris, including PPE and sanitation items, on wildlife from April 2020 to December 2021. We document the geographic occurrence of incidents, debris types, and consequences of incidents that were obtained from social media searches, unpublished reports from colleagues, and reports available from the citizen science database "Birds and Debris". There were 114 unique sightings of wildlife interactions with pandemic-related debris (38 from 2020 and 76 from 2021). Within the context of this dataset, most incidents involved birds (83.3 %), while fewer affected mammals (10.5 %), invertebrates (3.5 %), fish (1.8 %), and sea turtles (0.9 %). Sightings originated in 23 countries, and consisted mostly of entanglements (42.1 %) and nest incorporations (40.4 %). We verified sightings by contacting the original observers and were able to identify replicated sightings and increase the resolution of the data collected compared with previously published results. Due to the complexities associated with global use and accessibility of digital platforms, we likely underestimate the number of animals harmed by debris. Overall, the global scope of this study demonstrates that online and social media platforms are a valuable way to collect biologically relevant citizen science data and track rapidly emerging environmental challenges.Copyright © 2022 Elsevier B.V. All rights reserved.NHM Repositor
Evaluation and recommendations for greater accessibility of colour figures in ornithology
No full textPeople who are colour-blind or have some form of colour vision deficiency form an invisible minority and scientists should strive to be as inclusive as possible. We reviewed 2873 figures published in 2019 from 1031 scientific papers in 27 ornithological journals to determine those that were colour-blind compatible, and those that were black-and-white printer friendly. About 26% of the published figures were in colour, and while most were colour-blind compatible, only ~ 60% of them were black-and-white printer friendly. Ensuring figures in all forms of scientific communication can be interpreted by readers who are colour-blind, and can be printed in black-and-white will improve the accessibility of ornithological research.This is an open access article, available to all readers online, published under a creative commons licensing (https://creativecommons.org/licenses/by/4.0/). The attached file is the published version of the article.NHM Repositor
Revision of the Tomoderinae (Coleoptera: Anthicidae). Part III. New species and records of Macrotomoderus Pic, 1901 from China and a key to the Palaearctic species
Get PDFDescriptions of the following 23 species of Macrotomoderus Pic, 1901 new to science, from continental China, are provided as an addition to the recently published review of the genus from China and Taiwan (Telnov 2018): M. angelinii, M. belousovi, M. bicrispus, M. boops, M. bordonii, M. dali, M. daxiangling, M. femoridens, M. hajeki, M. hartmanni, M. hengduan, M. imitator, M. kabaki, M. korolevi, M. lapidarius, M. muli, M. palaung, M. similis, M. tenuis, M. transitans, M. truncatulus, M. usitatus, and M. wudu spp. nov. Additional records are provided for some poorly known species. The identification key to the species of Macrotomoderus from China, the Japanese Archipelago, and Taiwan is herewith significantly supplemented and updated. Biogeographical peculiarities and altitudinal gradient of Macrotomoderus distribution in continental China are briefly discussed.Copyright (c) 2022 Dmitry Telnov. This is an open access article distributed under the terms of the Creative Commons Attribution License, (https://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNHM Repositor
Ecology drives patterns of spectral transmission in the ocular lenses of frogs and salamanders
No full text1. The spectral characteristics of vertebrate ocular lenses affect the image of the world that is projected onto the retina, and thus help shape diverse visual capabilities. Here, we tested whether amphibian lens transmission is driven by adaptation to diurnal activity (bright light) and/or scansorial habits (complex visual environments).
2. Spectral transmission through the lenses of 79 species of frogs and six species of salamanders was measured, and data for 29 additional frog species compiled from published literature. Phylogenetic comparative methods were used to test ecological explanations of variation in lens transmission and to test for selection across traits.
3.Lenses of diurnal (day-active) and scansorial (climbing) frogs transmitted significantly less shortwave light than those of non-diurnal or non-scansorial amphibians, and evolutionary modelling suggested that these differences have resulted from differential selection.
4. The presence of shortwave-transparent lenses was common among the sampled amphibians, which implies that many are sensitive to shortwave light to some degree even in the absence of visual pigments maximally sensitive in the UV. This suggests that shortwave light, including UV, could play an important role in amphibian behaviour and ecology.
5
5. Shortwave-absorbing lens pigments likely provide higher visual acuity to diurnally active frogs of multiple ecologies and to nocturnally active scansorial frogs. This new mechanistic understanding of amphibian visual systems suggests that shortwave-filtering lenses are adaptive not only in daylight conditions but also in those scotopic conditions where high acuity is advantageous.The attached document is the author(’s’) final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it.NHM Repositor
Idalatry
Get PDFCopyright © 2009, The Palaeontological Association. The attached file is the published version of the article.NHM Repositor
A new, remarkable Chlorophila Semenov, 1891 (Coleoptera: Tenebrionidae: Lagriinae) from China
Get PDFChlorophila Semenov, 1891 is a small genus of emerald-green Lagriinae Latreille, 1825: Tenebrionidae Latreille, 1802 restricted to the mountain systems of China, the Himalayas, and northern Indochina. In the present paper a remarkable new species, Chlorophila gemma sp. nov. from mainland China, is described and illustrated.Copyright © 2021, The Author. The attached file is the published version of the article.NHM Repositor
Detecting ecological thresholds for biodiversity in tropical forests: Knowledge gaps and future directions
No full textNHM Repositor
Global population and conservation status of the Great Black-backed Gull Larus marinus
Get PDFThe Great Black-backed Gull Larus marinus is a generalist species that inhabits temperate and arctic coasts of the north Atlantic Ocean. In recent years, there has been growing concern about population declines at local and regional scales; however, there has been no attempt to robustly assess Great Black-backed Gull population trends across its global range. We obtained the most recent population counts across the species’ range and analysed population trends at a global, continental, and national scale over the most recent three-generation period (1985–2021) following IUCN Red List criteria. We found that, globally, the species has declined by 43%–48% over this period (1.2–1.3% per annum, respectively), from an estimated 291,000 breeding pairs to 152,000–165,000 breeding pairs under two different scenarios. North American populations declined more steeply than European ones (68% and 28%, respectively). We recommend that Great Black-backed Gull should be uplisted from ‘Least Concern’ to ‘Vulnerable’ on the IUCN Red List of Threatened Species under criterion A2 (an estimated reduction in population size >30% over three generations).Copyright ©TheAuthor(s), 2022. Published by Cambridge University Press on behalf of BirdLife International. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http:// creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited. The attached file is the published version of the article.NHM Repositor