Diatoms on earth,comets, europa and in interstellar space     

Hoover  Richard B.  Hoyle  Fred  Wickramasinghe  N. C.  Hoover  Miriam J.  Al-Mufti  S. 《Earth, Moon, and Planets》1986,35(1):19-45

There exists a close correspondence between the measured infrared properties of diatoms and the infrared spectrum of interstellar dust as observed in the Trapezium nebula and toward the galactic center source GC-IRS 7. Diatoms and bacteria also exhibit an absorbance peak near 2200 », which is found to agree with the observed ultraviolet absorbance properties of interstellar grains. We review the observational data and consider the known properties of diatoms and bacteria. It is suggested that these characteristics are consistent with the concept of a cosmic microbiological system in which these or similar microorganisms might exist on comets, Europa and in interstellar space.  相似文献   

A Plan to Push Limits? Investigating the ecologically sustainable development dimensions of Melbourne's Central Region sustainable water strategy     

Fiona Miller  Annie Bolitho  Natalie Jamieson  Charlotte Catmur  Anna Hurlimann  Kathryn Bowen 《The Australian geographer》2014,45(1):19-35

Drawing upon theory from the field of urban political ecology, we analyse a major strategic water plan for Melbourne, Australia—the Sustainable water strategy for the Central Region, published in 2006. We assess the extent to which the strategy identified and addressed ecological sustainability in terms of: cultural frames; ecological context; social equity; and engagement processes. We identify that the strategy's framing of water was largely separate from its social and ecological context. This framing resulted in the importance of issues such as environmental flows, social equity and cultural values being diminished, thus avoiding the inevitable confrontation with environmental limits needed to ensure long-term ecological sustainability. Our analysis shows that the discursive dominance of economics limited the response to persuasive scientific arguments for greater ecological consideration in the strategy. Our findings suggest that broadening engagement with the diverse ways in which water is valued is likely to contribute to more equitable and ecologically sustainable water futures.  相似文献   

<Superscript>10</Superscript>Be, <Superscript>18</Superscript>O and radiogenic isotopic constraints on the origin of adakitic signatures: a case study from Solander and Little Solander Islands,New Zealand     

Fiona?V.?FoleyEmail author  Simon?Turner  Tracy?Rushmer  John?T.?Caulfield  Nathan?R.?Daczko  Paul?Bierman  Matthew?Robertson  Craig?D.?Barrie  Adrian?J.?Boyce 《Contributions to Mineralogy and Petrology》2014,168(3):1048

Subduction-related Quaternary volcanic rocks from Solander and Little Solander Islands, south of mainland New Zealand, are porphyritic trachyandesites and andesites (58.20–62.19 wt% SiO₂) with phenocrysts of amphibole, plagioclase and biotite. The Solander and Little Solander rocks are incompatible element enriched (e.g. Sr ~931–2,270 ppm, Ba ~619–798 ppm, Th ~8.7–21.4 ppm and La ~24.3–97.2 ppm) with MORB-like Sr and Nd isotopic signatures. Isotopically similar quench-textured enclaves reflect mixing with intermediate (basaltic-andesite) magmas. The Solander rocks have geochemical affinities with adakites (e.g. high Sr/Y and low Y), whose origin is often attributed to partial melting of subducted oceanic crust. Solander sits on isotopically distinct continental crust, thus excluding partial melting of the lower crust in the genesis of the magmas. Furthermore, the incompatible element enrichments of the Solander rocks are inconsistent with partial melting of newly underplated mafic lower crust; reproduction of their major element compositions would require unrealistically high degrees of partial melting. A similar argument precludes partial melting of the subducting oceanic crust and the inability to match the observed trace element patterns in the presence of residual garnet or plagioclase. Alternatively, an enriched end member of depleted MORB mantle source is inferred from Sr, Nd and Pb isotopic compositions, trace element enrichments and εHf ? 0 CHUR in detrital zircons, sourced from the volcanics. ¹⁰Be and Sr, Nd and Pb isotopic systematics are inconsistent with significant sediment involvement in the source region. The trace element enrichments and MORB-like Sr and Nd isotopic characteristics of the Solander rocks require a strong fractionation mechanism to impart the high incompatible element concentrations and subduction-related (e.g. high LILE/HFSE) geochemical signatures of the Solander magmas. Trace element modelling shows that this can be achieved by very low degrees of melting of a peridotitic source enriched by the addition of a slab-derived melt. Subsequent open-system fractionation, involving a key role for mafic magma recharge, resulted in the evolved andesitic adakites.  相似文献   

Mycological evidence of coprophagy from the feces of an Alaskan Late Glacial mammoth     

Bas van Geel  R. Dale Guthrie  Jens G. Altmann  Peter Broekens  Ian D. Bull  Fiona L. Gill  Boris Jansen  Aline M. Nieman  Barbara Gravendeel 《Quaternary Science Reviews》2011,30(17-18):2289-2303

Dung from a mammoth was preserved under frozen conditions in Alaska. The mammoth lived during the early part of the Late Glacial interstadial (ca 12,300 BP). Microfossils, macroremains and ancient DNA from the dung were studied and the chemical composition was determined to reconstruct both the paleoenvironment and paleobiology of this mammoth. Pollen spectra are dominated by Poaceae, Artemisia and other light-demanding taxa, indicating an open, treeless landscape (‘mammoth steppe’). Fruits and seeds support this conclusion. The dung consists mainly of cyperaceous stems and leaves, with a minor component of vegetative remains of Poaceae. Analyses of fragments of the plastid rbcL gene and trnL intron and nrITS1 region, amplified from DNA extracted from the dung, supplemented the microscopic identifications. Many fruit bodies with ascospores of the coprophilous fungus Podospora conica were found inside the dung ball, indicating that the mammoth had eaten dung. The absence of bile acids points to mammoth dung. This is the second time that evidence for coprophagy of mammoths has been derived from the presence of fruit bodies of coprophilous fungi in frozen dung. Coprophagy might well have been a common habit of mammoths. Therefore, we strongly recommend that particular attention should be given to fungal remains in future fossil dung studies.  相似文献   

A Bacterial ‘Fingerprint’ in a Leonid Meteor Train     

N.C. Wickramasinghe  F. Hoyle 《Astrophysics and Space Science》2001,277(4):625-628

A recently observed broad 3.4 μm spectral ‘fingerprint’ in a persistent Leonid meteor train at a height of 83km is likely to be due to emission of surrounding mesospheric bacteria heated by the passage of an incandescent fireball. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Influence of environmental and prey variables on low tide shorebird habitat use within the Robbins Passage wetlands,Northwest Tasmania   总被引：1，自引：0，他引：1  

Fiona L. Spruzen  Alastair M.M. RichardsonEric J. Woehler 《Estuarine, Coastal and Shelf Science》2008

Shorebirds feed primarily on tidal flats, and their distribution over these flats is influenced by their prey and abiotic factors. These factors act by influencing the distribution and abundance of the prey, or the shorebirds ability to exploit it. The aims of this study were to investigate the low tide foraging distribution of shorebirds at four sites within the Robbins Passage wetlands, and the environmental and invertebrate factors that may influence their distribution. The greatest densities and number of shorebirds were found at Shipwreck Point and East Inlet. The shorebirds within-site distribution was also non-random, with the shorebirds present in greatest densities at the water's edge and low intertidal stratum, although this varied among species. Generally, on a small spatial scale, invertebrate diversity was positively correlated, and seagrass leaf mass was negatively correlated, with shorebird feeding density. On a large spatial scale, invertebrate biomass and seagrass root mass were positively correlated with shorebird feeding density. Invertebrate biomass and seagrass root mass explained 71% of the variance in total shorebird feeding density on the tidal flats. The variation in shorebird feeding density and diversity was therefore partly explained by invertebrate diversity and biomass, as well as the environmental factors seagrass roots and leaf mass and tidal flat area, although the strength of these relationships was influenced by the two different spatial scales of the study. The strength of the relationships between shorebird feeding density and the invertebrate and environmental variables was stronger on a large spatial scale. The presence of seagrass may have influenced shorebird-feeding density by affecting the invertebrate abundance and composition or the shorebirds ability to detect and capture their prey. The area of the tidal flat had opposing effects on the shorebird species. These results can be used to assist in the development of management plans for the Robbins Passage wetlands and the conservation of important shorebird areas.  相似文献   

Absorption properties of astronomical iron whiskers: an accurate cryogenic model     

N. C. Wickramasinghe  F. Hoyle 《Astrophysics and Space Science》1994,213(1):143-154

We combine the cryogenically measured value of the DC conductivity of iron with the Drude theory of electrical conduction of metals to determine a complex dielectric function relevant under interstellar and intergalactic conditions. We use this dielectric function to calculate the mass absorption coefficient of randomly oriented iron whiskers with radii 0.01 µm and of various lengths. Some astrophysical and cosmological implications are explored.  相似文献   

Statistical decadal predictions for sea surface temperatures: a benchmark for dynamical GCM predictions   总被引：1，自引：1，他引：0  

Chun Kit Ho  Ed Hawkins  Len Shaffrey  Fiona M. Underwood 《Climate Dynamics》2013,41(3-4):917-935

Accurate decadal climate predictions could be used to inform adaptation actions to a changing climate. The skill of such predictions from initialised dynamical global climate models (GCMs) may be assessed by comparing with predictions from statistical models which are based solely on historical observations. This paper presents two benchmark statistical models for predicting both the radiatively forced trend and internal variability of annual mean sea surface temperatures (SSTs) on a decadal timescale based on the gridded observation data set HadISST. For both statistical models, the trend related to radiative forcing is modelled using a linear regression of SST time series at each grid box on the time series of equivalent global mean atmospheric CO₂ concentration. The residual internal variability is then modelled by (1) a first-order autoregressive model (AR1) and (2) a constructed analogue model (CA). From the verification of 46 retrospective forecasts with start years from 1960 to 2005, the correlation coefficient for anomaly forecasts using trend with AR1 is greater than 0.7 over parts of extra-tropical North Atlantic, the Indian Ocean and western Pacific. This is primarily related to the prediction of the forced trend. More importantly, both CA and AR1 give skillful predictions of the internal variability of SSTs in the subpolar gyre region over the far North Atlantic for lead time of 2–5 years, with correlation coefficients greater than 0.5. For the subpolar gyre and parts of the South Atlantic, CA is superior to AR1 for lead time of 6–9 years. These statistical forecasts are also compared with ensemble mean retrospective forecasts by DePreSys, an initialised GCM. DePreSys is found to outperform the statistical models over large parts of North Atlantic for lead times of 2–5 years and 6–9 years, however trend with AR1 is generally superior to DePreSys in the North Atlantic Current region, while trend with CA is superior to DePreSys in parts of South Atlantic for lead time of 6–9 years. These findings encourage further development of benchmark statistical decadal prediction models, and methods to combine different predictions.  相似文献   

Assessing the institutional capacity to adapt to climate change: a case study in the Cambodian health and water sectors     

Va Dany  Kathryn J. Bowen  Fiona Miller 《Climate Policy》2013,13(3):388-409

Institutional capacity is an important element for climate change adaptation (CCA) and the development of such capacity is a great challenge in a Least Developed Country like Cambodia where resources are limited. An important first step to increasing capacity is via an understanding of the level of existing capacity; future priorities can then be subsequently identified. This study aimed to assess the capacity of organizations to implement climate change activities in Cambodia in order to provide such a basis for building capacity. Four elements of capacity were investigated in this research: (1) financial resources, (2) cooperation and coordination of stakeholders, (3) availability and quality of information on vulnerability and adaptation to climate change, and (4) the level of understanding of climate change vulnerability and adaptation. The data were collected through semistructured interviews with a wide range of government and non-government informants across a number of sectors. Results of the study showed that informants perceived capacity for CCA to be very constrained, especially in terms of financial resources and cooperation, and addressing these factors was ranked as the highest climate change capacity priority. Institutional capacity constraints were considered to relate more generally to weak governance of CCA. In light of our research findings, the absence of local higher education institutions in CCA activities should be addressed. The support of such institutions would provide an important mechanism to progress both capacity development as well as partnerships and coordination between different types of organizations and relevant sectors.

Policy relevance

Capacity for CCA within Cambodian health and water sectors was perceived to be very constrained across a range of interdependent factors. Increasing funding was ranked as the highest priority for building capacity for CCA; however, governance factors such as ‘improved cooperation’ were also ranked highly. Improving stakeholders' awareness of the availability of adaptation funds and resources, and their responsiveness to funding criteria, is an important implication of our research, as is improving the mobilization of local resources and the private sector. To address the issue of weak cooperation among stakeholders, improving the coordination function of the National Climate Change Committee (NCCC) regarding stakeholder engagement and capacity building is crucial. Ensuring that CCA activities are based on sound information and knowledge from across different disciplines and, importantly, include the perspectives of vulnerable people themselves, ultimately underpins and supports the realization of the above priorities.  相似文献   

Eruptions of comet Hale-Bopp at 6.5 AU     

N. C. Wickramasinghe  F. Hoyle  D. LLoyd 《Astrophysics and Space Science》1996,240(1):161-165

The prodigious output of dust and CO observed in comet Hale-Bopp at a heliocentric distance of 6.5 AU is strongly suggestive of high-pressure release of material from liquified subsurface domains rather than thermal evaporation from a sunlit patch of frozen CO.  相似文献