Europe between the oceans: Themes and variations: 9000 BC–AD 1000. Barry Cunliffe, 2008, Yale University Press,New Haven and London, 480 pp., ISBN: 978‐0‐300‐11923‐7, $39.95 (hardcover)     

Kathleen A. Nicoll 《Geoarchaeology》2009,24(6):855-856

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The Wave-Front Correction System for the Sunrise Balloon-Borne Solar Observatory     

T. Berkefeld  W. Schmidt  D. Soltau  A. Bell  H. P. Doerr  B. Feger  R. Friedlein  K. Gerber  F. Heidecke  T. Kentischer  O. v.?d. L??he  M. Sigwarth  E. W?lde  P. Barthol  W. Deutsch  A. Gandorfer  D. Germerott  B. Grauf  R. Meller  A. ??lvarez-Herrero  M. Kn?lker  V. Mart??nez Pillet  S. K. Solanki  A. M. Title 《Solar physics》2011,268(1):103-123

This paper describes the wave-front correction system developed for the Sunrise balloon telescope, and it provides information about its in-flight performance. For the correction of low-order aberrations, a Correlating Wave-Front Sensor (CWS) was used. It consisted of a six-element Shack??C?Hartmann wave-front sensor (WFS), a fast tip-tilt mirror for the compensation of image motion, and an active telescope secondary mirror for focus correction. The CWS delivered a stabilized image with a precision of 0.04?arcsec (rms), whenever the coarse pointing was better than ???45?arcsec peak-to-peak. The automatic focus adjustment maintained a focus stability of 0.01?waves in the focal plane of the CWS. During the 5.5?day flight, good image quality and stability were achieved during 33?hours, containing 45?sequences, which lasted between 10 and 45?min.  相似文献   

Behaviour of hatchery‐reared and wild‐caught 4th and 5th stage American lobsters,Homarus americanus     

Kathleen M. Castro  J. Stanley Cobb 《新西兰海洋与淡水研究杂志》2013,47(4):963-972

Behavioural deficiencies in 4th and 5th stage hatchery‐reared lobsters were examined using time budget analysis and predator trials. Hatchery‐reared 4th stage lobsters were found to behave differently than wild‐caught lobsters and differences existed between hatchery‐reared lobsters from different sources. Local hatchery‐reared 4th stage lobsters spent less time on shelter and suffered higher predator rates in laboratory trials than both wild‐caught 4th stage and lobsters reared in a hatchery in Maine. Fifth stage hatchery‐reared lobsters spent significantly more time in shelter than their wild‐caught counterparts. These differences may be attributable to the lack of development of proper predator‐avoidance behaviour and need to be understood and corrected to maximise the effect of enhancement projects.  相似文献   

Probabilistic Approach to Evaluation of Metal(loid) Fate During Stormwater Aquifer Storage and Recovery          下载免费PDF全文

Joanne L. Vanderzalm  Declan W. Page  Karen E. Barry  Kathleen Scheiderich  Dennis Gonzalez  Peter J. Dillon 《洁净——土壤、空气、水》2016,44(12):1672-1684

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THE ROLE OF VEGETATION DYNAMICS IN CHOCTAWHATCHEE SAND PINE INVASION OF LONGLEAF PINE FORESTS     

Deanna H. McCay  Kathleen C. Parker 《自然地理学》2013,34(6):467-482

The expansion of Choctawhatchee sand pine (Pinus clausa) into longleaf pine forests (Pinus palustris) has been widespread on the Florida Panhandle since the early 1900s. This study examines the population-level processes of this sand pine invasion. Expansion of sand pine started by 1920, but rapidly increased in the 1940s. Population establishment and growth in invasive stands has been rapid, with establishment of many sand pine pioneer individuals followed by rapid infilling as these individuals reached reproductive maturity. Both noninvasive and invasive stands had numerous sand pine seedlings and saplings. Sand pine will likely persist in these communities in the near future. Analyses of hemispherical canopy photographs and regeneration patterns illustrate the ability of sand pine to establish under a variety of light conditions. Radial growth analysis of incremental tree cores highlights the importance of episodic wind disturbances in maintaining these sand pine populations. [Key words: sand pine, longleaf pine, Pinus clausa, Florida, pine invasion, Pinus palustris.]  相似文献   

Assessment of drought over the past two millennia using near-shore sediment cores from a Canadian boreal lake     

Heather A. Haig  Melanie V. Kingsbury  Kathleen R. Laird  Peter R. Leavitt  Robyn Laing  Brian F. Cumming 《Journal of Paleolimnology》2013,50(2):175-190

Lack of long-term studies on drought in the boreal region of northwest Ontario limits our ability to assess the vulnerability of this region to climate change. We investigated changes in diatoms, scaled chrysophytes, and sedimentary pigments in two near-shore cores from Gall Lake to infer limnological and water-level changes over the last two millennia. The two coring locations, at modern water depths of 7.5 and 11.5 m, were selected to contrast inferences for past lake level based on distance from the modern water-depth boundary between predominantly benthic and planktonic diatom assemblages in surface sediments (6.0 m). Diatom-inferred depth inferences were more variable in the core from 7.5-m water depth, consistent with the hypothesis that the greatest changes occurred at water depths closest to the benthic:planktonic boundary. Both sites revealed a pronounced drought from ~AD 950 to 1300, synchronous with the medieval climate anomaly (MCA). This finding suggests a northeast expansion of the arid MCA into northwest Ontario, extending the known spatial extent of this megadrought. Scaled chrysophytes and sedimentary pigments suggest a recent increase in thermal stratification. Our findings indicate this region is more susceptible to changes in moisture than was previously suspected based on the instrumental record for the past century.  相似文献   

The effect of global warming on mortality     

Jean Calleja-Agius  Kathleen England  Neville Calleja 《Chemie der Erde / Geochemistry》2012

There is a significant relationship between ambient temperature and mortality. In healthy individuals with no underlying co-morbid conditions, there is an efficient heat regulation system which enables the body to effectively handle thermal stress. However, in vulnerable groups, especially in elderly over the age of 65 years, infants and individuals with co-morbid cardiovascular and/or respiratory conditions, there is a deficiency in thermoregulation. When temperatures exceed a certain limit, being cold winter spells or heat waves, there is an increase in the number of deaths. In particular, it has been shown that at temperatures above 27 °C, the daily mortality rate increases more rapidly per degree rise compared to when it drops below 27 °C.This is especially of relevance with the current emergency of global warming. Besides the direct effect of temperature rises on human health, global warming will have a negative impact on primary producers and livestock, leading to malnutrition, which will in turn lead to a myriad of health related issues. This is further exacerbated by environmental pollution.Public health measures that countries should follow should include not only health-related information strategies aiming to reduce the exposure to heat for vulnerable individuals and the community, but improved urban planning and reduction in energy consumption, among many others. This will reduce the carbon footprint and help avert global warming, thus reducing mortality.  相似文献   

Modeling Alternative Sequences of Events in Dynamic Geographic Domains     

Shane Hubbard  Kathleen Stewart Hornsby 《Transactions in GIS》2011,15(5):557-575

A model that emphasizes possible alternative sequences of events that occur over time is presented in this article. Representing alternative or branching events captures additional semantics unrealized by linear or non‐branching approaches. Two basic elements of branching, divergence and convergence are discussed. From these elements, many complex branching models can be built capturing a perspective of events that will take place in the future or have occurred in the past. This produces likely sequences of events that a user may compare and analyze using spatial or temporal criteria. The branching events model is especially useful for spatiotemporal decision support systems, as decision‐makers are able to identify alternative locations and times of events and, depending on the context, also identify regions of multiple possible events. A branching events viewer application is presented illustrating a case study based on a tornado response.  相似文献   

Retrospective and prospective model simulations of sea level rise impacts on Gulf of Mexico coastal marshes and forests in Waccasassa Bay, Florida   总被引：1，自引：0，他引：1  

Laura Geselbracht  Kathleen Freeman  Eugene Kelly  Doria R. Gordon  Francis E. Putz 《Climatic change》2011,107(1-2):35-57

The State of Florida (USA) is especially threatened by sea level rise due to extensive low elevation coastal habitats (approximately 8,000?km²?<?1?m above sea level) where the majority of the human population resides. We used the Sea Level Affecting Marshes Model (SLAMM) simulation to improve understanding of the magnitude and location of these changes for 58,000?ha of the Waccasassa Bay region of Florida??s central Gulf of Mexico coast. To assess how well SLAMM portrays changes in coastal wetland systems resulting from sea level rise, we conducted a hindcast in which we compared model results to 30?years of field plot data. Overall, the model showed the same pattern of coastal forest loss as observed. Prospective runs of SLAMM using 0.64?m, 1?m and 2?m sea level rise scenarios predict substantial changes over this century in the area covered by coastal wetland systems including net losses of coastal forests (69%, 83%, and 99%, respectively) and inland forests (33%, 50%, and 88%), but net gains of tidal flats (17%, 142%, and 3,837%). One implication of these findings at the site level is that undeveloped, unprotected lands inland from the coastal forest should be protected to accommodate upslope migration of this natural community in response to rising seas. At a broader scale, our results suggest that coastal wetland systems will be unevenly affected across the Gulf of Mexico as sea level rises. Species vulnerable to these anticipated changes will experience a net loss or even elimination.  相似文献   

IFKIS-Hydro: an early warning and information system for floods and debris flows     

Hans Romang  Massimiliano Zappa  Nadine Hilker  Matthias Gerber  François Dufour  Valérie Frede  Dominique Bérod  Matthias Oplatka  Christoph Hegg  Jakob Rhyner 《Natural Hazards》2011,56(2):509-527

IFKIS-Hydro is an information and warning system for hydrological hazards in small- and medium-scale catchments. The system collects data such as weather forecasts, precipitation measurements, water level gauges, discharge simulations and local observations of event-specific phenomena. In addition, IFKIS-Hydro incorporates a web-based information platform, which serves as a central hub for the submission and overview of data. Special emphasis is given to local information. This is accomplished particularly by human observers. In medium-scale catchments, discharge forecast models have an increasing importance in providing valuable information. IFKIS-Hydro was developed in several test regions in Switzerland and the first results of its application are available now. The system is constantly extended to additional regions and may become the standard for warning systems in smaller catchments in Switzerland.  相似文献