192 research outputs found

    Ocean acidification: summary for policymakers

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    This paper presents a summary of the state of knowledge on ocean acidification.Summary of outcomes:The ocean continues to acidify at an unprecedented rate in Earth’s history. Latest research indicates the rate of change may be faster than at any time in the last 300 million years.As ocean acidity increases, its capacity to absorb CO2 from the atmosphere decreases. This decreases the ocean’s role in moderating climate change. Species-specific impacts of ocean acidification have been seen in laboratory and field studies on organisms from the poles to the tropics. Many organisms show adverse effects, such as reduced ability to form and maintain shells and skeletons, as well as reduced survival, growth, abundance and larval development. Conversely, evidence indicates that some organisms tolerate ocean acidification and that others, such as some seagrasses, may even thrive. Within decades, large parts of the polar oceans will become corrosive to the unprotected shells of calcareous marine organisms. Changes in carbonate chemistry of the tropical ocean may hamper or prevent coral reef growth within decades.The far-reaching effects of ocean acidification are predicted to impact food webs, biodiversity, aquaculture and hence societies. Species differ in their potential to adapt to new environments. Ocean chemistry may be changing too rapidly for many species or populations to adapt through evolution.Multiple stressors – ocean acidification, warming, decreases in oceanic oxygen concentrations (deoxygenation), increasing UV-B irradiance due to stratospheric ozone depletion, overfishing, pollution and eutrophication – and their interactions are creating significant challenges for ocean ecosystems. We do not fully understand the biogeochemical feedbacks to the climate system that may arise from ocean acidification. Predicting how whole ecosystems will change in response to rising CO2 levels remains challenging. While we know enough to expect changes in marine ecosystems and biodiversity within our lifetimes, we are unable to make reliable, quantitative predictions of socio-economic impacts. People who rely on the ocean’s ecosystem services are especially vulnerable and may need to adapt or cope with ocean acidification impacts within decades. Shellfish fisheries and aquaculture in some areas may be able to cope by adjusting their management practices to avoid ocean acidification impacts. Tropical coral reef loss will affect tourism, food security and Katharina Fabricius shoreline protection for many of the world’s poorest people.Authors: Wendy Broadgate, IGBP; Ulf Riebesell, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; Claire Armstrong, University of TromsĂž, Norway; Peter Brewer, Monterey Bay Aquarium Research Institute, USA; Ken Denman, University of Victoria, Canada; Richard Feely, Pacific Marine Environmental Laboratory, NOAA, USA; Kunshan Gao, Xiamen University, China; Jean-Pierre Gattuso, CNRS-UPMC, Laboratoire d’OcĂ©anographie, France; Kirsten Isensee, IOC-UNESCO; Joan Kleypas, National Center for Atmospheric Research (Climate and Global Dynamics), USA; Dan Laffoley, International Union for Conservation of Nature, Switzerland; James Orr, Laboratoire des Sciences du Climat et l’Environnement, France; Hans-Otto Pörtner, Alfred Wegener Institute, Germany; Carlos Eduardo de Rezende, Universidade Estadual do Norte Fluminese, Brazil; Daniela Schmidt, University of Bristol, UK; Ed Urban, SCOR; Anya Waite, University of Western Australia; Luis ValdĂ©s, IOC-UNESCO

    Using fractals and power laws to predict the location of mineral deposits

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    Around the world the mineral exploration industry is interested in getting that small increase in probability measure on the earth's surface of where the next large undiscovered deposit might be found. In particular WMC Resources Ltd has operations world wide looking for just that edge in the detection of very large deposits of, for example, gold. Since the pioneering work of Mandelbrot, geologists have been familiar with the concept of fractals and self similarity over a few orders of magnitude for geological features. This includes the location and size of deposits within a particular mineral province. Fractal dimensions have been computed for such provinces and similarities of these aggregated measures between provinces have been noted. This paper explores the possibility of making use of known information to attempt the inverse process. That is, from lesser dimensional measures of a mineral province, for example, fractal dimension or more generally multi-fractal measures, is it possible to infer, even with small increase in probability, where the unknown (preferably large) deposits might be located

    Integrated approach to palaeoenvironmental reconstruction using GIS

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    Spatial and temporal variability of biogenic isoprene emissions from a temperate estuary

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    [1] Isoprene is important for its atmospheric impacts and the ecophysiological benefits it affords to emitting organisms; however, isoprene emissions from marine systems remain vastly understudied compared to terrestrial systems. This study investigates for the first time drivers of isoprene production in a temperate estuary, and the role this production may play in enabling organisms to tolerate the inherently wide range of environmental conditions. Intertidal sediment cores as well as high and low tide water samples were collected from four sites along the Colne Estuary, UK, every six weeks over a year. Isoprene concentrations in the water were significantly higher at low than high tide, and decreased toward the mouth of the estuary; sediment production showed no spatial variability. Diel isoprene concentration increased with light availability and decreased with tidal height; nighttime production was 79% lower than daytime production. Seasonal isoprene production and water concentrations were highest for the warmest months, with production strongly correlated with light (r2 = 0.800) and temperature (r2 = 0.752). Intertidal microphytobenthic communities were found to be the primary source of isoprene, with tidal action acting as a concentrating factor for isoprene entering the water column. Using these data we estimated an annual production rate for this estuary of 681 ÎŒmol m−2 y−1. This value falls at the upper end of other marine estimates and highlights the potentially significant role of estuaries as isoprene sources. The control of estuarine isoprene production by environmental processes identified here further suggests that such emissions may be altered by future environmental change

    “Genetic and clinical findings in an ethnically diverse retinitis pigmentosa cohort associated with pathogenic variants in EYS”

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    Background and objectives: The EYS gene is an important cause of autosomal recessive retinitis pigmentosa (arRP). The objective of this study is to report on novel pathogenic variants in EYS and the range of associated phenotypes. / Subjects and methods: This retrospective case series at a tertiary referral centre for inherited retinal diseases describes patients with an IRD and at least two variants in the EYS gene. Phenotyping included multimodal retinal imaging; genotyping molecular genetic analysis using targeted next generation sequencing. Sanger sequencing verification and analysis of novel variants using in silico approaches to determine their predicted pathogenicity. / Results: Eight male and four female patients were included. Age at onset ranged from 11 to 62 years with variable symptom presentation; ten patients showed classical features of retinitis pigmentosa, albeit with great variation in disease severity and extent. Two patients had atypical phenotypes: one with localised inferior sector pigmentation and a mild RP phenotype with changes predominantly at the posterior pole. Eighteen variants in EYS were identified, located across the gene: six were novel. Eight variants were missense, two altered splicing, one was a whole exon duplication and the remainder were predicted to result in premature truncation of the protein. / Conclusion: The marked variability in severity and age of onset in most patients in this ethnically diverse cohort adds to growing evidence that that mild phenotypes are associated with EYS variants. Similarly, the two atypical cases add to the growing diversity of EYS disease as do the six novel pathogenic variants described

    A Decision Support Demonstrator for Abiotic Damage to Trees, using a WWW Interface

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    Session 1A and 1B. Presentation slide

    Characterization of CDH3-Related Congenital Hypotrichosis With Juvenile Macular Dystrophy.

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    IMPORTANCE: Congenital hypotrichosis with juvenile macular dystrophy (HJMD) is a rare disorder presenting in childhood and adolescence with central visual disturbance and sparse scalp hair. Reported retinal imaging is lacking, and whether the condition is progressive remains unclear. OBJECTIVE: To investigate a series of patients with HJMD due to biallelic mutations in CDH3 and thereby characterize the disorder. DESIGN, SETTING, AND PARTICIPANTS: Ten patients from 10 families underwent detailed clinical assessment, including serial retinal imaging and electrophysiologic evaluation, at Moorfields Eye Hospital, St James's University Hospital, and Calderdale Royal Infirmary. Patients ranged in age from 3 to 17 years at onset and 5 to 57 years at last assessment. The molecular genetic investigation included bidirectional Sanger sequencing of all exons and intron-exon boundaries of CDH3 and whole-exome sequencing in 2 patients. The study was conducted from June 5, 2013, to January 15, 2016, with final follow-up completed on December 15, 2015. MAIN OUTCOMES AND MEASURES: Results of clinical assessment and molecular genetic testing. RESULTS: All 10 patients (7 male and 3 female) presented with central visual disturbance in childhood and had lifelong sparse scalp hair with normal facial hair. Fundus examination revealed chorioretinal atrophy of the posterior pole contiguous with the disc in all but 1 patient that was associated with marked loss of autofluorescence on fundus autofluorescence imaging. Optical coherence tomography (OCT) demonstrated variable degrees of atrophy of the outer retina, retinal pigment epithelium, and choroid, with outer retinal tubulations frequently observed. One patient had mild disruption of the inner segment ellipsoid band on OCT and additional mild digit abnormalities. Electrophysiologic evaluation in 5 patients demonstrated macular dysfunction with additional mild, generalized retinal dysfunction in 2 patients. Eight patients had more than 1 evaluation; of these, 5 patients showed deterioration of visual acuity over time, 1 patient remained stable, and 2 patients had severe visual loss at presentation that precluded assessment of visual deterioration. The area of atrophy did not progress with time, but retinal thickness decreased on OCT. Electrophysiologic evaluation in 1 patient found deterioration of macular function after 13 years of follow-up, but the mild, generalized photoreceptor dysfunction remained stable. Biallelic mutations were identified in all patients, including 6 novel mutations. CONCLUSIONS AND RELEVANCE: These results suggest that CDH3-related disease is characterized by a childhood-onset, progressive chorioretinal atrophy confined to the posterior pole. The disease is readily distinguished from other juvenile macular dystrophies by the universally thin and sparse scalp hair. Patients may have additional limb abnormalities
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