10,249 research outputs found
Dataset for: Artificial light at night (ALAN) affects the downstream movement behaviour of the critically endangered European eel, Anguilla anguilla
No full textThis dataset supports the publication: Vowles, A.S. & Kemp, P.S. (2021). Artificial light at night (ALAN) affects the downstream movement behaviour of the critically endangered European eel, Anguilla anguilla. Environmental Pollution</span
Letter. Late cretaceous seasonal ocean variability from the arctic
No full textThe modern Arctic Ocean is regarded as barometer of global change and amplifier of global warming1 and therefore records of past Arctic change are of a premium for palaeoclimate reconstruction. Little is known of the state of the Arctic Ocean in the greenhouse period of the late Cretaceous, yet records from such times may yield important clues to its future behaviour given current global warming trends. Here we present the first seasonally resolved sedimentary record from the Cretaceous from the Alpha Ridge of the Arctic Ocean. This “paleo-sediment trap” provides new insights into the workings of the Cretaceous marine biological carbon pump. Seasonal primary production was dominated by diatom algae but was not related to upwelling as previously hypothesised. Rather, production occurred within a stratified water column, involving specially adapted species in blooms resembling those of the modern North Pacific Subtropical Gyre, or those indicated for the Mediterranean sapropels. With increased CO2 levels and warming currently driving increased stratification in the global ocean, this style of production that is adapted to stratification may become more widespread. Our evidence for seasonal diatom production and flux testify to an ice-free summer, but thin accumulations of terrigenous sediment within the diatom ooze are consistent with the presence of intermittent sea ice in the winter, supporting a wide body of evidence for low temperatures in the Late Cretaceous Arctic Ocean, rather than recent suggestions of a 15 °C mean annual temperature at this time
"You're all very quiet this morning" [John Howard enters the Party room where Alexander Downer, Peter Costello, Peter Reith, David Kemp and Amanda Vanstone are reading newspapers about the resignation of New Zealand Prime Minister Jim Bolger] [picture] /
No full textTitle devised by cataloguer.; Inscriptions: "June 2000; Howard popularity down"--in ink on verso.; Published in 1997? (the year of Jim Bolger's resignation).; Published in the Sydney Morning Herald.; Part of the Moir collection of cartoons and drawings.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-vn3535654; Donated through the Australian Government's Cultural Gifts Program by Alan Moir, 2005
Tropical ocean-atmosphere controls on inter-annual climate variability in the Cretaceous Arctic
No full textThe first annually resolved sedimentary record from the Cretaceous is used to develop time series of inter-annual and decadal scale climate variability from the Arctic Ocean. Analysis of records spanning 1000 years reveals strong periodicities in the quasi-biennial oscillation and El Niño – Southern Oscillation (ENSO) band as well as a 14 year period, which all closely match periodicities typical of modern high latitude climate variability. This supports the view that an Arctic Ocean free of permanent sea ice would be driven by similar forcing to the present state, implicating tropical ocean atmosphere interaction and demonstrating that stratosphere- troposphere coupling likely played a prominent role in the transmission of Cretaceous equatorial climate forcing to polar latitudes as has recently been established for the modern earth system. On the other hand, the prominent ENSO periodicities in our records argue against the hypothesized link between past warm climates and “permanent El Niño” states
Artificial light at night (ALAN) affects the downstream movement behaviour of the critically endangered European eel, <i>Anguilla anguilla</i>
No full textArtificial light at night (ALAN) is considered one of the most pervasive forms of environmental pollution. It is an emerging threat to freshwater biodiversity and can influence ecologically important behaviours of fish. The European eel (Anguilla anguilla) is a critically endangered catadromous species that migrates downstream to the ocean to spawn in the Sargasso Sea. Given the pervasive nature of ALAN, many eel will navigate through artificially lit routes during their seaward migration, and although considered negatively phototactic, their response has yet to be quantified. We investigated the response of downstream moving European eel to simulated ALAN using a Light Emitting Diode unit in an experimental flume. We presented two routes of passage under: (1) a dark control (both channels unlit), (2) low ALAN (treatment channel lit to ca. 5 lx), or (3) high ALAN (treatment channel lit to ca. 20 lx). Eel were: (i) more likely to reject an illuminated route when exposed to high levels of ALAN; (ii) less likely to select the illuminated channel when given a choice; and (iii) passed downstream more rapidly when the illuminated route was selected. This study quantified the response of the critically endangered European eel to ALAN under an experimental setting, providing the foundations for future field based research to validate these findings, and offering insight on the ecological impacts of this major environmental pollutant and driver of global change
Evidence for abrupt climate changes in annually laminated marine sediments
No full textAnnually laminated sediments from marine or lacustrine settings represent valuable high-resolution archives of climate change that record variation due to changing precipitation and run-off from land or variation in biological productivity and flux in the water column. Because of their annual resolution such sediments may capture abrupt changes of interannual to decadal scales rivaling corals and ice cores in resolution. Laminated sediments often occur intermittently in the sediment column, and the onset and cessation of laminae commonly record the abrupt crossing of thresholds related to climate change, for example, in the degree of oxygenation of bottom waters. Such records from marginal basins and continental margins have been pivotal in demonstrating that abrupt changes hitherto documented only in high-latitude ice cores are synchronous with climatic change at low latitudes. These insights into global teleconnections have improved our understanding of the mechanisms of rapid climate change. In deep-sea settings, the discovery of the episodic occurrence of laminated diatom-rich sediments in the Equatorial Pacific and Southern Ocean provides evidence for massive climate-related biogeochemical excursions tied to abrupt changes in the input, distribution and availability of nutrients in the oceans
Electrophysiological and pharmacological studies of the rat substantia nigra
No full textThis study is an investigation at the single neurone level of the pharmacology and afferent connections of the rat substantia nigra. In urethane, anaesthetised rats multibarrel glass micropipettes were used to record extracellular single unit activity and for the iontophoretic application of drugs. Concentric bipolar electrodes were used for the electrical stimulation of substantia nigra afferents. Iontophoretic application of substance P strongly excited substantia nigra neurones supporting its role as the excitatory transmitter in the striatonigral pathway. Leucine-enkephalin and D-serine2-methionineenkephalin were powerful depressants. f of nigral neurone activity while methionine-enkephalin was, less potent. Morphine had only excitatory effects in the substantia nigra. These results are explained in terns of different 'opiate' receptors. Bradykinin, neurotensin and angiotensin were all without effect when iontophoretically applied to sub stantia nigra neurones. Dopamine and noradrenaline had both excitatory and inhibitory effects on nigral neurones but the lack of correlation between their effects on the same cells suggests an action at separate receptors. 5-hydroxytryptamine also excited and inhibited substantia nigra neurones, the predominant effect being excitatory. Acetylcholine strongly excited a large percentage of substantia nigra neurones, though some were inhibited. Evidence from other cholinergic agonists and antagonists suggests that the excitations are both muscarinic and nicotinic while the inhibitions were muscarinic. The levels of amino acids within the substantia nigra were measured and those present in large amounts were iontophoretically applied to substantia nigra neurones. While baclofen inhibits nigral neurones it is unlikely to be by an action on GAGA receptors as its effects are not antagonised by picrotoxin. Evidence from electrical stimulation of the nucleus accumbens suggests that this nucleus can influence substantia nigra activity in a number of ways and that its direct effect is mainly through an inhibitory, possibly GABAergic, projection.</p
Good Education in a Fragile World: The Value of a Collaborative and Contextualised Approach to Sustainability in Higher Education
No full textThis edited collection aims to provoke discussion around the most important question for contemporary higher education – what kind of education (in terms of purpose, pedagogy and policy) is needed to restore the health and wellbeing of the planet and ourselves now and for generations to come? The book contains contributions from colleagues at a single UK University, internationally recognised for its approach to sustainability education.
Introducing a conceptual framework called the ‘Paradox Model’, the book explores the tensions that underpin the challenge of developing sustainability in higher education in the 21st century. It asks probing questions about the purpose of higher education in the 21st century given growing concerns in relation to planetary safety and justice and calls for a rethinking of educational purpose. It draws upon the theory and practice of education and explores how these can develop an understanding of sustainability pedagogies in practice. Finally, it delivers thought-provoking discussion on what constitutes a ‘good’ higher education that meets the needs of a world in crisis. Drawing on a planetary health lens, the book concludes with a ‘manifesto’ that brings together the key insights from the contributing authors.
This will be an engaging volume for academics and educators from a wide range of disciplines in higher educational settings interested in translating sustainability theory into educational practice.https://www.routledge.com/Good-Education-in-a-Fragile-World-The-Value-of-a-Collaborative-and-Contextualised/Bainbridge-Kemp/p/book/9781032260976#inpressinpres
Records of seasonal flux in Holocene laminated sediments, Gulf of California
No full textHolocene laminated sediments from Guaymas Basin (Gulf of California, Mexico) have, in the past, been described as annual couplets of sedimentation. Couplets comprise an alternation of diatom- and terrigenous-rich sediment reflecting winter and summer flux to the sediment respectively. New data from backscattered electron imagery (BSEI) show that a three-component pattern of sedimentation is preserved, comprising (1) a lithogenic lamina consisting of clays, silt and minor diatomaceous material, deposited during the summer and autumn wet season; (2) a mixed flora diatomaceous lamina deposited during the early winter collapse of the thermocline and onset of water column mixing; and (3) a near-monospecific flora lamina of Chaetoceros resting spores or, more rarely, Skeletonema costatum, representing deposition from, or at the end of, the spring coastal upwelling bloom. Recent sediment trap biogenic and terrigenous flux data also show three to four major flux events per year. Direct comparisons are possible between BSEI records and recent sediment trap flux data to facilitate high-resolution palaeoceanaographic and palaeoclimatic reconstructions throughout the Holocene
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