294 research outputs found
Trends in MODIS and AERONET derived aerosol optical thickness over Northern Europe
Long-term Aqua and Terra MODIS (MODerate resolution Imaging Spectroradiometer) Collections 5.1 and 6.1 (c051 and c061, respectively) aerosol data have been combined with AERONET (AERosol RObotic NETwork) ground-based sun photometer observations to examine trends in aerosol optical thickness (AOT, at 550 nm) over Northern Europe for the months April to September. For the 1927 and 1559 daily coincident measurements that were obtained for c051 and c061, respectively, MODIS AOT varied by 86 and 90%, respectively, within the predicted uncertainty of one standard deviation of the retrieval over land (ΔAOT = ±0.05 ± 0.15·AOT). For the coastal AERONET site Gustav Dalen Tower (GDT), Sweden, larger deviations were found for MODIS c051 and c061 (79% and 75%, respectively, within predicted uncertainty). The Baltic Sea provides substantially better statistical representation of AOT than the surrounding land areas and therefore favours the investigations of trends in AOT over the region. Negative trends of 1.5% and 1.2% per year in AOT, based on daily averaging, were found for the southwestern Baltic Sea from MODIS c051 and c061, respectively. This is in line with a decrease of 1.2% per year in AOT at the AERONET station Hamburg. For the western Gotland Basin area, Sweden, negative trends of 1.5%, 1.1% and 1.6% per year in AOT have been found for MODIS c051, MODIS c061 and AERONET GDT, respectively. The strongest trend of –1.8% per year in AOT was found for AERONET Belsk, Poland, which can be compared to –1.5% per day obtained from MODIS c051 over central Poland. The trends in MODIS and AERONET AOT are nearly all statistically significant at the 95% confidence level. The strongest aerosol sources are suggested to be located southwest, south and southeast of the investigation area, although the highest prevalence of pollution events is associated with air mass transport from southwest.Peer reviewe
Spaceborne observations of low surface aerosol concentrations in the Stockholm region
© 2016 M. Tesche et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License, allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license.This article investigates the feasibility of using spaceborne observations of aerosol optical thickness (AOT) derived with the Moderate Resolution Imaging Spectroradiometer (MODIS) for monitoring of fine particulate matter (PM2.5) in an environment of low aerosol loading. Previous studies of the AOT-to-PM2.5 relationship benefit from the large range of observed values. The Stockholm region features a comprehensive network of ground-based monitoring stations that generally show PM2.5 values <20 µg m−3. MODIS AOT at 555 nm is usually <0.20 and in good agreement with ground-based sun photometer observations in this region. We use MODIS Collection 5 AOT data with a horizontal resolution of 10 km×10 km and ground-based in-situ PM2.5 observations to derive an AOT-to-PM2.5 relationship that can be used to estimate fields of PM2.5. This has been carried out with respect to the months from April to September of the period 2000–2013. Relative average absolute deviations of 33–55 % (mean of 45 %) are obtained between MODIS-retrieved and ground-based PM2.5. The root mean square error is 0.2159 µg m−3 between retrieved and measured PM2.5. From spaceborne lidar observations, it is found that elevated aerosol layers are generally sparse in the Stockholm region. This favours remote sensing of PM2.5 from space. The deviations found between measured and retrieved PM2.5 are mainly attributed to infrequent situations of inhomogeneous aerosol layering for which column-integrated observations cannot be connected to surface conditions. Using MODIS Collection 6 data with a resolution of 3 km×3 km in a case study actually gives far fewer results than the coarser Collection 5 product. This is explained by the complex geography of the Stockholm region with a coastline and an abundance of lakes, which seems to induce biases in the retrieval of AOT at higher spatial resolution.Peer reviewedFinal Published versio
Immobilization of Shewanella oneidensis MR-1 in diffusive gradients in thin films for determining metal bioavailability
Assessing metal bioavailability in soil is important in modelling the effects of metal toxicity on the surrounding ecosystem. Current methods based on diffusive gradient thin films (DGTs) and Gel-Integrated Microelectrode are limited in their availability and sensitivity. To address this, S. oneidensis, an anaerobic iron reducing bacterium, was incorporated into a thin layer of agarose to replace the polyacrylamide gel that is normally present in DGT to form biologically mobilizing DGT (BMDGT). Viability analysis revealed that 16-35% of the cells remained viable within the BMDGTs depending on the culturing conditions over a 20 h period with/without metals. Deployment of BMDGTs in standardized metal solutions showed significant differences to cell free BMDGTs when cells grown in Luria Broth (LB) were incorporated into BMDGTs and deployed under anaerobic conditions. Deployment of these BMDGTs in hematite revealed no significant differences between BMDGTs and BMDGTs containing heat killed cells. Whether heat killed cells retain the ability to affect bioavailability is uncertain. This is the first study to investigate how a microorganism that was incorporated into a DGT device such as the metal reducing bacteria, S. oneidensis, may affect the mobility of metals
Identification and Biosynthesis of Novel Male Specific Esters in the Wings of the Tropical Butterfly, Bicyclus martius sanaos
Representatives of the highly speciose tropical butterfly genus Bicyclus (Lepidoptera: Nymphalidae) are characterized by morphological differences in the male androconia, a set of scales and hair pencils located on the surface of the wings. These androconia are assumed to be associated with the release of courtship pheromones. In the present study, we report the identification and biosynthetic pathways of several novel esters from the wings of male B. martius sanaos. We found that the volatile compounds in this male butterfly were similar to female-produced moth sex pheromones. Components associated with the male wing androconial areas were identified as ethyl, isobutyl and 2-phenylethyl hexadecanoates and (11Z)-11-hexadecenoates, among which the latter are novel natural products. By topical application of deuterium-labelled fatty acid and amino acid precursors, we found these pheromone candidates to be produced in patches located on the forewings of the males. Deuterium labels from hexadecanoic acid were incorporated into (11Z)-11-hexadecenoic acid, providing experimental evidence of a Δ11-desaturase being active in butterflies. This unusual desaturase was found previously to be involved in the biosynthesis of female-produced sex pheromones of moths. In the male butterflies, both hexadecanoic acid and (11Z)-11-hexadecenoic acid were then enzymatically esterified to form the ethyl, isobutyl and 2-phenylethyl esters, incorporating ethanol, isobutanol, and 2-phenylethanol, derived from the corresponding amino acids L-alanine, L-valine, and L-phenylalanine
When is it biological control? A framework of definitions, mechanisms, and classifications
Biological control, or biocontrol, is the exploitation of living agents (incl. viruses) to combat pestilential organisms (incl. pathogens, pests, and weeds) for diverse purposes to provide human benefits. Thus, during the last century the practices and concepts involved have evolved in separate streams associated with distinct scientific and taxonomic disciplines. In parallel developments, there have been increasing references to biological control in industrial contexts and legislation, resulting in conceptual and terminological disintegration. The aim of this paper is to provide a global conceptual and terminological platform that facilitates future development of the field. We review use of previously suggested terms in key fields (e.g., phytopathology, entomology, and weed science), eliminate redundant terminology, identify three principles that should underpin the concept, and then present a new framework for biological control, rooted in seminal publications. The three principles establish that (1) only living agents can mediate biological control, (2) biological control always targets a pest, directly or indirectly, and (3) all biocontrol methods can be classified in four main categories depending on whether resident agents are utilized, with or without targeted human intervention (conservation biological control and natural biological control, respectively) or agents are added for permanent or temporary establishment (classical biological control and augmentative biological control, respectively). Correct identification of what is, and is not, biological control can help efforts to understand and optimize biological pest control for human and environmental benefits. The new conceptual framework may contribute to more uniform and appropriate regulatory approaches to biological control, and more efficient authorization and application of biocontrol products
Fugler i Norge 2003 – Rapport fras Norsk faunakomité for fugl (NFKF)
THE NORWEGIAN BIRD REPORT 2003 - a report on locally uncommon and scarce birds in Norway in 2003, by the Norwegian Bird Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. All counties contributed to the report for 2003, although the Svalbard archipelago and Jan Mayen as well as Finnmark, Troms, Sogn & Fjordane and Vest-Agder counties did not publish own county reports. We believe this report reflects fairly well observations from Norway in 2003. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Bird Records Committee (NFKF) has published annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was the best in NFKFs history, while the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be low. One breeding pair of Pink-footed Goose Anser brachyrhynchus at Grindøya, Troms county was the first breeding attempt on the Norwegian mainland (excepting an attempt by a hybrid pair). Bar-headed Goose Anser indicus was seen in exceptionally good numbers. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2003 was the best year to date for this species. One breeding record of Smew Mergellus albellus from Vikna, Nord-Trøndelag county was the first breeding record in Norway outside Finnmark. The occurrence of Common Quail Coturnix coturnix and Corncrake Crex crex was the second best, while the occurrence of Spotted Crake Porzana porzana was the third best in NFKFs history. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2003 was the best year ever. The occurrence of Avocets Recurvirostra avosetta and Black-tailed Godwits Limosa limosa was the best ever in NFKFs history, while the occurrence of migrating Broad-billed Sandpiper Limicola falcinellus was poor with only one individual during the autumn migration period. Migrating Pomarine Skuas Stercorarius pomarinus and Long-tailed Skuas Stercorarius longicaudus were seen in good numbers and the occurrence of Glaucous Gulls Larus hyperboreus was the best in NFKFs history. Also the occurrence of Little Gulls Larus minutus was very good, givingc the second best year ever. Turtle Doves Streptopelia turtur had a very good year during both spring and autumn, giving the best year in NFKFs history. The number of Hoopoes Upupa epops was the third best since 1991. The occurrences of Wood Larks Lullula arborea and Richard’s Pipits Anthus richardi was the third best, while the occurrence of Red-throated Pipits Anthus cervinus was very low. The number of Pied Wagtails Motacilla alba yarrellii, singing Grasshopper Warblers Locustella naevia, Yellow-browed Warblers Phylloscopus inornatus and Red-breasted Flycatchers Ficedula parva was the highest ever recorded, while Marsh Warbler Acrocephalus palustris, Barred Warblers Sylvia nisoria and Great Grey Shrikes Lanius excubitor experienced second best numbers since 1991. The number of Golden Oriole Oriolus oriolus was the lowest ever recorded in NFKFs history. Two-barred Crossbills Loxia leucoptera continued to occur in good numbers after the autumn 2002 influx, but very few individuals remained after the summer. The Hawfinch Coccothraustes coccothraustes still show a marked increase in the north of its distribution range, especially in the Trøndelag counties. The Ortolan Bunting Emberiza hortulana continued to occur in low numbers while the occurrence of Little Buntings Emberiza pusilla was the second best in NFKFs history
The ERA2 facility: towards application of a fiber-based astronomical spectrograph for imaging spectroscopy in life sciences
Astronomical instrumentation is most of the time faced with challenging
requirements in terms of sensitivity, stability, complexity, etc., and
therefore leads to high performance developments that at first sight appear to
be suitable only for the specific design application at the telescope. However,
their usefulness in other disciplines and for other applications is not
excluded. The ERA2 facility is a lab demonstrator, based on a high-performance
astronomical spectrograph, which is intended to explore the innovation
potential of fiber-coupled multi-channel spectroscopy for spatially resolved
spectroscopy in life science, material sciences, and other areas of research.Comment: 10 pages, 9 figures, SPIE Conference "Astronomical Telescopes and
Instrumentation" 2012, Amsterda
The symple choice algorythm for estimating of parametersof network protetion prioroties in analitical hierarchic process
Humans depend on services provided by ecosystems, and how services are affected by climate change is increasingly studied. Few studies, however, address changes likely to affect services from seminatural ecosystems. We analyzed ecosystem goods and services in natural and seminatural systems, specifically how they are expected to change as a result of projected climate change during the 21st century. We selected terrestrial and freshwater systems in northernmost Europe, where climate is anticipated to change more than the global average, and identified likely changes in ecosystem services and their societal consequences. We did this by assembling experts from ecology, social science, and cultural geography in workshops, and we also performed a literature review. Results show that most ecosystem services are affected by multiple factors, often acting in opposite directions. Out of 14 services considered, 8 are expected to increase or remain relatively unchanged in supply, and 6 are expected to decrease. Although we do not predict collapse or disappearance of any of the investigated services, the effects of climate change in conjunction with potential economical and societal changes may exceed the adaptive capacity of societies. This may result in societal reorganization and changes in ways that ecosystems are used. Significant uncertainties and knowledge gaps in the forecast make specific conclusions about societal responses to safeguard human well-being questionable. Adapting to changes in ecosystem services will therefore require consideration of uncertainties and complexities in both social and ecological responses. The scenarios presented here provide a framework for future studies exploring such issues
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