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Eastern Part (eastern + part)
Selected AbstractsMartin Stutzmann: Editor, Teacher, Scientist and FriendPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2005Manuel Cardona On 2 January 1995 Martin Stutzmann became Editor-in-Chief of physica status solidi, replacing Professor E. Gutsche, who had led the journal through the stormy period involving the fall of the Iron Curtain, the unification of Germany and the change in its Eastern part, where physica status solidi was based, from "socialism as found in the real world" (a German concept) to real world capitalism. In 1995 it was thought that the process had been completed (we should have known better!) and after the retirement of Prof. Gutsche the new owners of physica status solidi (Wiley-VCH) decided that a change in scientific management was desirable to adapt to the new socio-political facts and to insure the scientific continuity of the journal. Martin had moved in 1993 from my department at the Max-Planck-Institute to Munich where he soon displayed a tremendous amount of science man- agement ability during the build-up of the Walter Schottky Institute. The search for a successor as Edi- tor-in-Chief was not easy: the job was not very glamorous after the upheavals which had taken place in the editorial world following the political changes. Somebody in the Editorial Boards must have suggested Martin Stutzmann. I am sure that there was opposition: one usually looks for a well-established person ready to leave his direct involvement in science and take up a new endeavor of a more administrative nature. Nevertheless, the powers that be soon realized that Martin was an excellent, if somewhat unconventional candidate who had enough energy to remain a topnotch scientist and to lead the journal in the difficult times ahead: he was offered the job. In the negotiations that followed, he insisted in getting the administrative structures that would allow him to improve the battered quality of the journal and to continue his scientific productivity. Today we are happy to see that he succeeded in both endeavors. The journal has since grown in size and considerably improved its quality. Martin Stutzmann's scientific output has continued and today he can be found listed among the 400 most cited physicists worldwide. According to the Institute of Scientific Information (ISI) he has published nearly 400 articles in source journals; they have been cited over 4600 times. His scientific visibility has been partly responsible for the success of the journal under his leadership. When he took over in 1995 the Impact Factors of physica status solidi (a) and (b) were about 0.5. Now they oscillate around 1.0. The journals occupy places 30 (a) and 29 (b) among the 57 condensed matter publications listed in the ISI. Six years ago these places were 34 (a) and 30 (b). The journal is even better placed with respect to the so-called cited half-life which is 8.2 years for pss (a) (place 16 among 57) and 6.7 years for pss (b) (place 20 among 57). Martin, of course, has contributed with his original publications to the success of the journal, having published 36 articles in pss(a) and 32 in pss(b). I would like to some of the editorial decisions implemented under Martin's leadership. They have been largely responsible for the quantitative improvements just described. Martin introduced international standards of peer review, usually involving two anonymous referees: The increase of the rejection rate from ca. 20% to 60% followed. He discontinued the Short Notes, which had become nearly irrelevant, and replaced them, in 1997 by Rapid Research Notes (today Rapid Research Letters) with especially strict reviewing rules and a rather attractive layout. Martin's participation in many international conferences and their organization gave him a handle to acquire the publication of conference proceedings. Organizing committees usually prefer publication in international journals rather than special books because of their guaranteed future availability in libraries and the partaking in the reviewing procedure. The journal became increasingly popular along these lines, a fact which moved Martin to launch in 2002 part (c) of the journal, devoted mainly, but not exclusively, to conference articles. Martin also introduced the publication of Feature Articles, topical issues, and the instrument of the Editor's Choice to highlight articles deemed to be especially interesting. He appointed Regional Editors (6 at this point) which represent the journal in important geographic regions. He also brought the journal online, a must these days. The upheavals that followed the collapse of most of the communist world, the rapid development of science in many emerging nations and the enhanced competitiveness, even in the developed countries, have not ebbed out. Some of them are particular damaging to the reputation of science in a world increasingly skeptical of its values. I am thinking of scientific misconduct and outright fraud, in the form of plagiarism and data fabrication. physica status solidi was also afflicted by this plague: after all, it happened in the best of families. Two of the most notorious offenders of the past decade, J. H. Schön and Y. Park, also visited physica status solidi. In two courageous editorials Martin Stutzmann and Stefan Hildebrandt (Managing Editor of the journal) rapidly exposed these cases of misconduct together with other cases in which there was also good reason to suspect misconduct. Some of the articles involved were rapidly retracted by the authors, others were not. It is reassuring to say that none of them had any impact worth mentioning (1,3 citations, mostly by the authors themselves or in the editorials just mentioned). Only few journal editors dared to convey to the readers a warning that some work of those authors may be faulty even if no air-tight proof was available. However, Martin and Stefan did. We wish that Martin will remain at the helm at least another decade, before he switches to research on the liquid state as practiced in Southern France. [source] Concise Total Synthesis of the Thiazolyl Peptide Antibiotic GE2270,ACHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2008Oscar Delgado Dr. Abstract The potent antibiotic thiazolylpeptide GE2270,A was synthesized starting from N - tert -butyloxycarbonyl protected valine in a longest linear sequence of 20 steps and with an overall yield of 4.8,%. Key strategy was the assembly of the 2,3,6-trisubstituted pyridine core by consecutive cross-coupling reactions starting from 2,6-dibromo-3-iodopyridine. The complete Southern fragment was installed by Negishi cross-coupling of 3-zincated 2,6-dibromopyridine at the terminal 2-iodothiazole of a trithiazole (87,%). The substituent at C-6 representing the Northern part of the molecule was introduced in form of the truncated tert -butyl 2-bromothiazole-4-carboxylate after metalation to a zinc reagent by another Negishi cross-coupling (48,%). Decisive step of the whole sequence was the macrocyclization to a 29-membered macrolactam, which was conducted as an intramolecular Stille cross-coupling occurring at C-2 of the pyridine core and providing the desired product in 75,% yield. The required stannane was obtained by amide bond formation (87,%) between a complex dithiazole fragment representing the Eastern part of GE2270,A and a 3,6-disubstituted 2-bromopyridine. Final steps included attachment of a serine-proline amide dipeptide to the Northern part of the molecule (65,%), formation of the oxazoline ring and silyl ether deprotection (55,% overall). [source] Soil organic carbon stocks in China and changes from 1980s to 2000sGLOBAL CHANGE BIOLOGY, Issue 9 2007ZUBIN XIE Abstract The estimation of the size and changes of soil organic carbon (SOC) stocks is of great importance for decision makers to adopt proper measures to protect soils and to develop strategies for mitigation of greenhouse gases. In this paper, soil data from the Second State Soil Survey of China (SSSSC) conducted in the early 1980s and data published in the last 5 years were used to estimate the size of SOC stocks over the whole profile and their changes in China in last 20 years. Soils were identified as paddy, upland, forest, grassland or waste-land soils and an improved soil bulk density estimation method was used to estimate missing bulk density data. In the early 1980s, total SOC stocks were estimated at 89.61 Pg (1 Pg=103 Tg=1015 g) in China's 870.94 Mha terrestrial areas covered by 2473 soil series. In the paddy, upland, forest and grassland soils the respective total SOC stocks were 2.91 Pg on 29.87 Mha, 10.07 Pg on 125.89 Mha, 34.23 Pg on 249.32 Mha and 37.71 Pg on 278.51 Mha, respectively. The SOC density of the surface layer ranged from 3.5 Mg ha,1 in Gray Desery grassland soils to 252.6 Mg ha,1 in Mountain Meadow forest soils. The average area-weighted total SOC density in paddy soils (97.6 Mg ha,1) was higher than that in upland soils (80 Mg ha,1). Soils under forest (137.3 Mg ha,1) had a similar average area-weighted total SOC density as those under grassland (135.4 Mg ha,1). The annual estimated SOC accumulation rates in farmland and forest soils in the last 20 years were 23.61 and 11.72 Tg, respectively, leading to increases of 0.472 and 0.234 Pg SOC in farmland and forest areas, respectively. In contrast, SOC under grassland declined by 3.56 Pg due to the grassland degradation over this period. The resulting estimated net SOC loss in China's soils over the last 20 years was 2.86 Pg. The documented SOC accumulation in farmland and forest soils could thus not compensate for the loss of SOC in grassland soils in the last 20 years. There were, however, large regional differences: Soils in China's South and Eastern parts acted mainly as C sinks, increasing their average topsoil SOC by 132 and 145 Tg, respectively. In contrast, in the Northwest, Northeast, Inner Mongolia and Tibet significant losses of 1.38, 0.21, 0.49 and 1.01 Pg of SOC, respectively, were estimated over the last 20 years. These results highlight the importance to take measures to protect grassland and to improve management practices to increase C sequestration in farmland and forest soils. [source] European AIDS Clinical Society (EACS) guidelines for the clinical management and treatment of HIV-infected adultsHIV MEDICINE, Issue 2 2008N Clumeck A working group of the European AIDS Clinical Society (EACS) have developed these guidelines for European clinicians to help them in the treatment of adults with HIV infection. This third version of the guidelines includes, as new topics, the assessment of patients at initial and subsequent clinic visits as well as post-exposure prophylaxis. A revision of the 2005 guidelines based on current data includes changes in the sections on primary HIV infection, when to initiate therapy, which drug combinations are preferred as initial combination regimens for antiretroviral-naïve patients, how to manage virological failure and the treatment of HIV during pregnancy. In Europe, there is a wide range of clinical practices in antiretroviral therapy depending on various factors such as drug registration, national policies, local availability, reimbursement and access to treatment. These can vary greatly from one country to another, especially in Central and Eastern parts of Europe. These guidelines are intended to help clinicians achieve the best care for their patients. In some countries, particularly where the quality of and access to care are not optimal, these guidelines should help AIDS societies and physicians or patient group organizations to negotiate with their national health authorities with a view to implementing what should be the standard of care for HIV-infected patients all over Europe. [source] The problems of sustainable water use in the Mediterranean and research requirements for agricultureANNALS OF APPLIED BIOLOGY, Issue 3 2004J LARAUS Summary This study addresses the sustainable use of water resources in the Mediterranean basin, particularly in the Southern and Eastern parts of the region, and the many problems generated by water scarcity and misuse. Water economy in the region is beset by two specific problems: high irrigation needs and changes in consumer demands (especially after population shifts from rural to urban areas and because of increasing tourism and industrialisation). The challenges presented by the water crisis are even greater because of growing populations and estimated future climatic changes in the region. The integrated management of limited water resources in the Southern and Eastern parts of the Mediterranean involves several areas of research. Those most directly related with agriculture concern improving water (and nutrient) use in agriculture through the management and breeding of irrigated and rain-fed crops. However, these fields of research address only one face of a multi-factorial equation that affects water sustainability in the region. Thus, other research fields include the design of comprehensive water policies and integrated planning, and technologies for advanced water treatment and re-use. Moreover, local problems and socio-economic aspects must be considered when addressing research issues. [source] Glechoma hederacea (Lamiaceae) in North America: invasion history and current distribution,FEDDES REPERTORIUM, Issue 1-2 2004M. Scholler Glechoma hederacea L. (Ground-ivy, Lamiaceae), a perennial mat-forming herb, is native to the temperate regions of Eurasia and was introduced elsewhere (South East Asia, New Zealand and North America). Based on data obtained from herbaria, literature, online and other data bases and field studies, we documented the invasion history and current distribution of this plant in North America. At present, the plant is recorded from all but two continental states of the USA and all southern provinces of Canada. There are two main ranges: the larger one covers mainly the eastern part of the U.S.A. and a smaller one stretches along the West Coast. While published records of Glechoma hederacea date from 1814, the oldest specimen is from 1829. During the 19th century the species spread westwards at a rate of approximately 30 km/year. The spread and present range of G. hederacea can only be explained by climatic factors (degree of oceanicity) and considering human activity. Especially long distance propagation of vegetative parts of the plants and the change of the environment that accompanies human settlements may have had a major influence on these processes. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Glechoma hederacea L. (Lamiaceae) in Nordamerika: Invasionsgeschichte und derzeitige Verbreitung Glechoma hederacea (Gewöhnlicher Gundermann; Lamiaceae), eine im temperaten Eurasien beheimatete ausdauernde krautige Pflanze konnte sich als Neophyt in Südostasien, Neuseeland und Nordamerika etablieren. Basierend auf Daten aus der Literatur und Datenbanken, Belegdaten aus Herbarien und Felduntersuchungen werden die Ausbreitungsgeschichte der Art in Nordamerika und ihr gegenwärtiges Areal dokumentiert. Gegenwärtig ist die Art aus allen kanadischen Provinzen und mit Ausnahme von zwei Bundesstaaten auch von allen kontinentalen Bundesstaaten der USA dokumentiert. Es gibt zwei Hauptareale: ein großes, welches einen Großteil der östlichen USA einnimmt und ein kleineres an der Westküste. Der älteste Nachweis von 1814 von Glechoma hederacea stammt aus der Literatur, der älteste Beleg von 1829. Im Laufe des 19. Jahrhunderts breitete sich die Art mit einer Geschwindigkeit von etwa 30 km/Jahr nach Westen aus. Ausbreitungsgeschwindigkeit und das gegenwärtige Areal können nur mit Hilfe klimatischer (Ozeanität) und anthropogener Faktoren erklärt werden. Der Mensch trägt vor allem zur Verbreitung vegetativer Pflanzenteile bei und schafft in Siedlungen günstige Wachstumsbedingungen. [source] Present status, and social and economic significance of inland fisheries in GermanyFISHERIES MANAGEMENT & ECOLOGY, Issue 4-5 2001H. Wedekind The Federal Republic of Germany is situated in the central part of Europe and covers an area of 358 000 km2. The climate is maritime in the north and continental in the south with precipitation varying between 600 and 2000 mm year,1. Lakes and farm ponds are common in the north-eastern part of the country and in the alpine and pre-alpine regions to the south. A great number of small natural and artificial water bodies exist all over the country. There are about 800 000 ha of inland waters. The population of 82 million people are concentrated around a number of large conurbations. Over the last 150 years, intense use of the water resources by industry led to pollution and a severe decrease in river and lake fisheries. Only 587 inland fishing enterprises still existed in the early 1990s. Catches from commercial fisheries are decreasing with a total of 3469 t being caught in 1998. The Lake Constance fishery, which landed about 840 t in 1998, is an exception to the general trend. Strong competition for the aquatic resource is affecting commercial fisheries, whilst recreational fisheries have gained increasing importance over the last decades. Recent studies provided basic information on anglers' habits, social structure and economic significance as well as their effects on the waters. Aquaculture mainly produces rainbow trout, Oncoryhnchus mykiss (Walbaum) 20 000 t and carps (12 000 t) e.g. Cyprinus carpio L. Despite pressures from industry and conservation movements, regional support for fisheries and their development has intensified, leading to improved water quality. There are even attempts to re-establish abandoned fisheries. Co-operation with conservationists provides an opportunity for the future survival and development of fisheries. The fisheries and aquaculture sectors changed drastically after the reunification of Germany. The collapse of the infrastructure in the eastern part of Germany led to a decline in production and to a special investigation on recent developments of this sector. [source] An experimental and modeling study of Na-rich hydrothermal alterationGEOFLUIDS (ELECTRONIC), Issue 4 2005J. HARA Abstract Sodic alteration assemblages including clinoptilolite, mordenite, analcime and Na-montmorillonite were locally observed in sediments in the eastern part of the Hachimantai geothermal region, northeast Japan. This study investigated the mechanisms of sodic enrichment in the sediments during alteration. Kinetic results for water/rock interaction experiments are reported here. Batch-type experiments were conducted at 150,250°C under saturated vapor pressure. Pyroclastic rocks dissolved incongruently in these experiments, and the solubility and dissolution rates among elements varied as follows: the apparent steady-state concentrations of major elements are Si > Na , K > Ca > Al and the order of the dissolution rates is Si > Al > Na , K > Ca. Na had the highest steady-state concentration and fastest dissolution rate of the alkali and alkali earth metal ions. Based on surface analysis of plagioclase, dissolution was effected via a reaction layer of Na-montmorillonite on the mineral surface. Additionally, a reaction model constructed based on the experimentally observed reaction mechanism quantitatively explains the dissolution behavior. These results show that Na-montmorillonite can be precipitated by pyroclastic rock/meteoric water interactions without seawater involvement: the Na is derived from the host rocks. [source] The bright spot in the West Carpathian upper mantle: a trace of the Tertiary plate collision,and a caveat for a seismologistGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2010Piotr SUMMARY The 2-D full waveform modelling of the mantle arrivals from the CELEBRATION 2000 profiles crossing the Carpathian orogen suggests two possible tectonic models for the collision of ALCAPA (Alpine-Carpathian-Pannonian) and the European Plate in the West Carpathians in southern Poland and Slovakia. Due to an oblique (NE-SW) convergence of plates, the character of the collision may change along the zone of contact of the plates: in the western part of the area an earlier collision might have caused substantial crustal shortening and formation of a crocodile-type structure, with the delaminated lower crust of ,100 km length acting as a north-dipping reflecting discontinuity in the uppermost mantle. In the eastern part, a less advanced collision only involved the verticalization of the subducted slab remnant after a slab break-off. The lower crustal remnant of ,10 km size in the uppermost mantle acts as a pseudo-diffractor generating observable mantle arrivals. Due to the similarity of synthetic data generated by both models, the question of the non-uniqueness of seismic data interpretation, that may lead to disparate tectonic inferences, is also discussed. [source] Mechanical deformation model of the western United States instantaneous strain-rate fieldGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2006Fred F. Pollitz SUMMARY We present a relationship between the long-term fault slip rates and instantaneous velocities as measured by Global Positioning System (GPS) or other geodetic measurements over a short time span. The main elements are the secularly increasing forces imposed by the bounding Pacific and Juan de Fuca (JdF) plates on the North American plate, viscoelastic relaxation following selected large earthquakes occurring on faults that are locked during their respective interseismic periods, and steady slip along creeping portions of faults in the context of a thin-plate system. In detail, the physical model allows separate treatments of faults with known geometry and slip history, faults with incomplete characterization (i.e. fault geometry but not necessarily slip history is available), creeping faults, and dislocation sources distributed between the faults. We model the western United States strain-rate field, derived from 746 GPS velocity vectors, in order to test the importance of the relaxation from historic events and characterize the tectonic forces imposed by the bounding Pacific and JdF plates. Relaxation following major earthquakes (M, 8.0) strongly shapes the present strain-rate field over most of the plate boundary zone. Equally important are lateral shear transmitted across the Pacific,North America plate boundary along ,1000 km of the continental shelf, downdip forces distributed along the Cascadia subduction interface, and distributed slip in the lower lithosphere. Post-earthquake relaxation and tectonic forcing, combined with distributed deep slip, constructively interfere near the western margin of the plate boundary zone, producing locally large strain accumulation along the San Andreas fault (SAF) system. However, they destructively interfere further into the plate interior, resulting in smaller and more variable strain accumulation patterns in the eastern part of the plate boundary zone. Much of the right-lateral strain accumulation along the SAF system is systematically underpredicted by models which account only for relaxation from known large earthquakes. This strongly suggests that in addition to viscoelastic-cycle effects, steady deep slip in the lower lithosphere is needed to explain the observed strain-rate field. [source] Regional teleseismic tomography of the western Lachlan Orogen and the Newer Volcanic Province, southeast AustraliaGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2002Frank M. Graeber Summary From 1998 May to September a portable array of 40 short-period digital seismograph stations was operated in western Victoria, southeast Australia, across the western end of the mid-Paleozoic Lachlan Foldbelt and the Newer Volcanic Province. Consisting of four parallel, almost W,E-oriented receiver lines, the array covered an area of about 270 × 150 km2. The major aim of the LF98 (Lachlan Foldbelt survey 1998) project is to map lateral variations in P -wave speeds (Vp) in the crust and upper mantle using teleseismic arrival time tomography, primarily in order to investigate whether the major surface structural zones are associated with seismic velocity signatures at depth. Little a priori information from seismic profiling is available. We invert 4067 relative arrival time residuals for a minimum structure Vp model in the upper few hundred km using non-linear iteration and 3-D ray tracing. The most prominent negative anomaly (,3.8 per cent) in Vp is found at a depth of about 45 km underneath the eastern part of the Newer Volcanic Province. It correlates spatially with the highest density of Pliocene and Pleistocene eruption centres northwest of Melbourne, and is therefore interpreted as a hotspot-related high-temperature anomaly causing reduced mantle velocities. The related coherent volume of significantly lower than average velocities extends down to depths greater than 100 km in the east, and extends west underneath the Newer Volcanic Province. A strong velocity contrast, with average velocities ,2 per cent greater in the west, is found down to about 100 km across the Moyston Fault Zone, which forms the major structural boundary between the early-Paleozoic Delamerian Orogen in the west and the Lachlan Orogen in the east. This result suggests that the Moyston Fault Zone should be seen as a major lithospheric boundary. In the south this boundary is also expressed by a distinct discontinuity in Sr-isotopic ratios of xenoliths (the so-called Mortlake discontinuity) and a change in the geochemistry of plutons of similar age. However, if the east to west velocity contrast originally existed in this southern zone, it is now overprinted by the thermally reduced mantle velocities beneath the Newer Volcanic Province. [source] Regional GPS data confirm high strain accumulation prior to the 2000 June 4 Mw= 7.8 earthquake at southeast SumatraGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2001G. W. Michel Summary Site velocities derived from repeated measurements in a regional GPS network in Southeast Asia help to constrain the motion of tectonic blocks as well as slip rates along major faults in the area. Using 3-D forward dislocation modelling, the influence of seismic elastic loading and unloading on the measured site motions are approximated. Results suggest that the northwestern Sunda arc is fully coupled seismogenically, whereas its eastern part along Java shows localized deformation. Higher horizontal velocity gradients than expected from the modelling of a fully coupled plate interface west of Manila in the Philippines suggest that deformation may be localized there. Assuming that geodetically derived convergence represents long-term rates, accumulated geodetic moments are compared to those derived using seismic data from 1977 to 2000 (Harvard CMT catalogue). If areas displaying localized deformation are dominated by creep processes, the largest difference between accumulated and seismically released deformation is located where the 2000 June 4 Mw = 7.8 Sumatra earthquake occurred. [source] Spatial analysis of instream nitrogen loads and factors controlling nitrogen delivery to streams in the southeastern United States using spatially referenced regression on watershed attributes (SPARROW) and regional classification frameworks,HYDROLOGICAL PROCESSES, Issue 16 2009Anne B. Hoos Abstract Understanding how nitrogen transport across the landscape varies with landscape characteristics is important for developing sound nitrogen management policies. We used a spatially referenced regression analysis (SPARROW) to examine landscape characteristics influencing delivery of nitrogen from sources in a watershed to stream channels. Modelled landscape delivery ratio varies widely (by a factor of 4) among watersheds in the southeastern United States,higher in the western part (Tennessee, Alabama, and Mississippi) than in the eastern part, and the average value for the region is lower compared to other parts of the nation. When we model landscape delivery ratio as a continuous function of local-scale landscape characteristics, we estimate a spatial pattern that varies as a function of soil and climate characteristics but exhibits spatial structure in residuals (observed load minus predicted load). The spatial pattern of modelled landscape delivery ratio and the spatial pattern of residuals coincide spatially with Level III ecoregions and also with hydrologic landscape regions. Subsequent incorporation into the model of these frameworks as regional scale variables improves estimation of landscape delivery ratio, evidenced by reduced spatial bias in residuals, and suggests that cross-scale processes affect nitrogen attenuation on the landscape. The model-fitted coefficient values are logically consistent with the hypothesis that broad-scale classifications of hydrologic response help to explain differential rates of nitrogen attenuation, controlling for local-scale landscape characteristics. Negative model coefficients for hydrologic landscape regions where the primary flow path is shallow ground water suggest that a lower fraction of nitrogen mass will be delivered to streams; this relation is reversed for regions where the primary flow path is overland flow. Published in 2009 by John Wiley & Sons, Ltd. [source] Dispersal and migration of juvenile African Black Oystercatchers Haematopus moquiniIBIS, Issue 3 2003Philip A. R. Hockey African Black Oystercatchers Haematopus moquini are sedentary as adults. However, colour-ringing of more than 700 juveniles has revealed complex post-fledging movements that vary geographically. Young from the western part of the breeding range either remain within 150 km of their natal site or migrate 1500,2000 km to one of five discrete nursery areas on the Namib Desert coast of central and northern Namibia, and southern Angola. These nurseries all lie north of the species' breeding range. We calculate that 36,46% of all juveniles born in South Africa migrate to nurseries. Birds return to their natal sites from nurseries at 2,3 years old, but never migrate again. Juveniles from the eastern part of the range undertake ,diffusion dispersal', regularly up to 1000 km, but these journeys mostly end within the breeding range, where there are no nurseries. Very few eastern birds reach nurseries. There is no evidence that movements of western birds are density-dependent responses to hatching date, but long-distance migrants are significantly heavier as chicks than are short-distance dispersers. We hypothesize that a genetic basis exists to these movements, possibly triggered by body condition, that could account not only for the highly dichotomous behaviour of western birds, but also for the intermediate behaviour of eastern birds. [source] Consensus between GCM climate change projections with empirical downscaling: precipitation downscaling over South AfricaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2006B. C. Hewitson Abstract This paper discusses issues that surround the development of empirical downscaling techniques as context for presenting a new approach based on self-organizing maps (SOMs). The technique is applied to the downscaling of daily precipitation over South Africa. SOMs are used to characterize the state of the atmosphere on a localized domain surrounding each target location on the basis of NCEP 6-hourly reanalysis data from 1979 to 2002, and using surface and 700-hPa u and v wind vectors, specific and relative humidities, and surface temperature. Each unique atmospheric state is associated with an observed precipitation probability density function (PDF). Future climate states are derived from three global climate models (GCMs): HadAM3, ECHAM4.5, CSIRO Mk2. In each case, the GCM data are mapped to the NCEP SOMs for each target location and a precipitation value is drawn at random from the associated precipitation PDF. The downscaling approach combines the advantages of a direct transfer function and a stochastic weather generator, and provides an indication of the strength of the regional versus stochastic forcing, as well as a measure of stationarity in the atmosphere,precipitation relationship. The methodology is applied to South Africa. The downscaling reveals a similarity in the projected climate change between the models. Each GCM projects similar changes in atmospheric state and they converge on a downscaled solution that points to increased summer rainfall in the interior and the eastern part of the country, and a decrease in winter rainfall in the Western Cape. The actual GCM precipitation projections from the three models show large areas of intermodel disagreement, suggesting that the model differences may be due to their precipitation parameterization schemes, rather than to basic disagreements in their projections of the changing atmospheric state over South Africa. Copyright © 2006 Royal Meteorological Society. [source] Visitor and non-visitor images of Central and Eastern Europe: a qualitative analysisINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 1 2008Howard L. Hughes Abstract This study examines the image of Central and Eastern Europe (CEE) as a holiday destination. The countries are linked by having had communist governments and being inaccessible to tourists from outside the communist bloc. Currently, they seek new tourist markets and this study examines the views of a number of UK residents about destination image of CEE. The study examines, through semi-structured interviews, images held by people who have and who have not visited CEE. The data is analysed qualitatively. Few significant differences were found between views of visitors and non-visitors; most views were positive and associated favourably with ,culture'. Negative images were usually associated with the eastern part of the area especially ex-Yugoslavia. Copyright © 2007 John Wiley & Sons, Ltd. [source] Zircon U,Pb ages and tectonic implications of ,Early Paleozoic' granitoids at Yanbian, Jilin Province, northeast ChinaISLAND ARC, Issue 4 2004Yanbin Zhang Abstract The Yanbian area is located in the eastern part of the Central Asian Orogenic Belt (CAOB) of China and is characterized by widespread Phanerozoic granitic intrusions. It was previously thought that the Yanbian granitoids were mainly emplaced in the Early Paleozoic (so-called ,Caledonian' granitoids), extending east,west along the northern margin of the North China craton. However, few of them have been precisely dated; therefore, five typical ,Caledonian' granitic intrusions (the Huangniling, Dakai, Mengshan, Gaoling and Bailiping batholiths) were selected for U,Pb zircon isotopic study. New-age data show that emplacement of these granitoids extended from the Late Paleozoic to Late Mesozoic (285,116 Ma). This indicates that no ,Caledonian' granitic belt exists along the northern margin of the North China craton. The granitoids can be subdivided into four episodes based on our new data: Early Permian (285 ± 9 Ma), Early Triassic (249,245 Ma), Jurassic (192,168 Ma) and Cretaceous (119,116 Ma). The 285 ± 9 Ma tonalite was most likely related to subduction of the Paleo-Asian Oceanic Plate beneath the North China craton, followed by Triassic (249,245 Ma) syn-collisional monzogranites, representing the collision of the CAOB orogenic collage with the North China craton and final closure of the Paleo-Asian Ocean. The Jurassic granitoids resulted from subduction of the Paleo-Pacific plate and subsequent collision of the Jiamusi,Khanka Massif with the existing continent, assembled in the Triassic. The Early Cretaceous granitoids formed in an extensional setting along the eastern Asian continental margin. [source] Winter selection of landscapes by woodland caribou: behavioural response to geographical gradients in habitat attributesJOURNAL OF APPLIED ECOLOGY, Issue 5 2008Daniel Fortin Summary 1Understanding animal,habitat relationships is central to the development of strategies for wildlife management and conservation. The availability of habitat attributes often changes along latitudinal and longitudinal axes, and animals may respond to those changes by adjusting their selection. We evaluated whether landscape selection by forest-dwelling woodland caribou Rangifer tarandus caribou varied along geographical gradients in habitat attributes. 2Centroids (n = 422) of track networks made by caribou in winter were recorded during aerial surveys conducted over 161 920 km2 of boreal forest in Québec, Canada. Autologistic models were estimated by comparing the characteristics of landscapes (201 km2) centred on each centroid to an equal number of randomly located landscapes, with an autocovariate controlling for the non-independence among caribou locations. 3The availability of habitat attributes varied along longitudinal and latitudinal gradients, and caribou altered their landscape selection with respect to those gradients. 4Information Theory provided substantial support for only one model. The model revealed that the probability of occurrence of caribou increased with the abundance of conifer forests over most of the study region, but this positive response gradually became negative towards the southern portion of the region. The association between caribou and lichens changed from being negative west of the study region to being positive in the eastern part. Availability of landscapes dominated by lichen decreased from west to east. Finally, caribou generally displayed an aversion to areas with high road density, a negative association that became positive in the southern part of the study region. 5Synthesis and applications. Under current legislation in Canada, the critical habitat of woodland caribou must be defined, and then protected. Our autoregressive models can help to identify landscapes to prioritize conservation efforts. The probability of occurrence of caribou was related to different landscape characteristics across their range, which implies that the typical habitat of woodland caribou differs spatially. Such behavioural plasticity could be problematic for defining critical habitat, but we showed that spatial variation in landscape selection was organized along geographical gradients. Our study illustrates how geographical trends in habitat selection can guide management and conservation decisions. [source] Genetic structure of Hypochaeris uniflora (Asteraceae) suggests vicariance in the Carpathians and rapid post-glacial colonization of the Alps from an eastern Alpine refugiumJOURNAL OF BIOGEOGRAPHY, Issue 12 2007Patrik Mráz Abstract Aim, The range of the subalpine species Hypochaeris uniflora covers the Alps, Carpathians and Sudetes Mountains. Whilst the genetic structure and post-glacial history of many high-mountain plant taxa of the Alps is relatively well documented, the Carpathian populations have often been neglected in phylogeographical studies. The aim of the present study is to compare the genetic variation of the species in two major European mountain systems , the Alps and the Carpathians. Location, Alps and Carpathians. Methods, The genetic variation of 77 populations, each consisting of three plants, was studied using amplified fragment length polymorphism (AFLP). Results, Neighbour joining and principal coordinate analyses revealed three well-supported phylogeographical groups of populations corresponding to three disjunct geographical regions , the Alps and the western and south-eastern Carpathians. Moreover, two further clusters could be distinguished within the latter mountain range, one consisting of populations from the eastern Carpathians and the second consisting of populations from the southern Carpathians. Populations from the Apuseni Mountains had an intermediate position between the eastern and southern Carpathians. The genetic clustering of populations into four groups was also supported by an analysis of molecular variance, which showed that most genetic variation (almost 46%) was found among these four groups. By far the highest within-population variation was found in the eastern Carpathians, followed by populations from the southern and western Carpathians. Generally, the populations from the Alps were considerably less variable and displayed substantially fewer region-diagnostic markers than those from the south-eastern Carpathians. Although no clear geographical structure was found within the Alps, based on neighbour joining or principal coordinate analyses, some trends were obvious: populations from the easternmost part were genetically more variable and, together with those from the south-western part, exhibited a higher proportion of rare AFLP fragments than populations in other areas. Moreover, the total number of AFLP fragments per population, the percentage of polymorphic loci and the proportion of rare AFLP fragments significantly decreased from east to west. Main conclusions, Deep infraspecific phylogeographical gaps between the populations from the Alps and the western and south-eastern Carpathians suggest the survival of H. uniflora in three separate refugia during the last glaciation. Our AFLP data provide molecular evidence for a long-term geographical disjunction between the eastern and western Carpathians, previously suggested from the floristic composition at the end of 19th century. It is likely that Alpine populations survived the Last Glacial in the eastern part of the Alps, from where they rapidly colonized the rest of the Alps after the ice sheet retreated. Multiple founder effects may explain a gradual loss of genetic variation during westward colonization of the Alps. [source] Zeolites in fissures of granites and gneisses of the Central AlpsJOURNAL OF METAMORPHIC GEOLOGY, Issue 8 2010T. WEISENBERGER Abstract Six different Ca-zeolite minerals are widespread in various assemblages in late fissures and fractures in granites and gneisses of the Swiss Alps. The zeolites formed as a result of water,rock interaction at relatively low temperatures (<250 °C) in the continental upper crust. The zeolites typically overgrow earlier minerals of the fissure assemblages, but zeolites also occur as monomineralic fissure fillings. They represent the youngest fissure minerals formed during uplift and exhumation of the Alpine orogen. A systematic study of zeolite samples showed that the majority of finds originate from three regions particularity rich in zeolite-bearing fissures: (i) in the central and eastern part of the Aar- and Gotthard Massifs; (2) Gibelsbach/Fiesch, in a fissure breccia located at the boundary of Aar Massif and Permian sedimentary rocks; and (3) in Penninic gneisses of the Simano nappe at Arvigo (Val Calanca). Rail and road tunnel construction across the Aar- and Gotthard Massif provided excellent data on zeolite frequency in Alpine fissures. It was found that 32% (Gotthard NEAT rail base tunnel, Amsteg section) and 18% (Gotthard road tunnel) of all studied fissures are filled with zeolites. The number of different zeolites is limited to six species: laumontite, stilbite and scolecite are abundant and common, whereas heulandite, chabazite and epistilbite occur occasionally. Calcium is the dominant extra-framework cation, with minor K and Na. Heulandite and chabazite contain Sr up to 29 and 10 mol.% extra-framework cations respectively. Na and K contents in zeolites tend to increase during growth as a result of changes in fluid composition and/or temperature. The K enrichment of stilbite found in surface outcrops compared to subsurface samples may indicate late stage cation exchange with surface water. Texture data, relative age sequences derived from fissure assemblages and equilibrium calculations show that the Ca-dominated zeolites precipitated from fluid with decreasing temperature in the order (old to young = hot to cold): scolecite, laumontite, heulandite, chabazite and stilbite. The necessary components for zeolite formation are derived from dissolving primary granite and gneiss minerals. The nature of these minerals depends, among other factors, on the metamorphic history of the host rock. Zeolites in the Aar Massif derived from the dissolution of epidote, secondary calcite and albite that were originally formed during Alpine greenschist metamorphism from primary granite and gneiss assemblages. Zeolite fissures occur in areas of H2O-dominated fluids. This is consistent with equilibrium calculations that predict a low CO2 tolerance of zeolite assemblages, particularly at low temperature. [source] Origin of migmatites by deformation-enhanced melt infiltration of orthogneiss: a new model based on quantitative microstructural analysisJOURNAL OF METAMORPHIC GEOLOGY, Issue 1 2008P. HASALOVÁ Abstract A detailed field study reveals a gradual transition from high-grade solid-state banded orthogneiss via stromatic migmatite and schlieren migmatite to irregular, foliation-parallel bodies of nebulitic migmatite within the eastern part of the Gföhl Unit (Moldanubian domain, Bohemian Massif). The orthogneiss to nebulitic migmatite sequence is characterized by progressive destruction of well-equilibrated banded microstructure by crystallization of new interstitial phases (Kfs, Pl and Qtz) along feldspar boundaries and by resorption of relict feldspar and biotite. The grain size of all felsic phases decreases continuously, whereas the population density of new phases increases. The new phases preferentially nucleate along high-energy like,like boundaries causing the development of a regular distribution of individual phases. This evolutionary trend is accompanied by a decrease in grain shape preferred orientation of all felsic phases. To explain these data, a new petrogenetic model is proposed for the origin of felsic migmatites by melt infiltration from an external source into banded orthogneiss during deformation. In this model, infiltrating melt passes pervasively along grain boundaries through the whole-rock volume and changes completely its macro- and microscopic appearance. It is suggested that the individual migmatite types represent different degrees of equilibration between the host rock and migrating melt during exhumation. The melt topology mimicked by feldspar in banded orthogneiss forms elongate pockets oriented at a high angle to the compositional banding, indicating that the melt distribution was controlled by the deformation of the solid framework. The microstructure exhibits features compatible with a combination of dislocation creep and grain boundary sliding deformation mechanisms. The migmatite microstructures developed by granular flow accompanied by melt-enhanced diffusion and/or melt flow. However, an AMS study and quartz microfabrics suggest that the amount of melt present did not exceed a critical threshold during the deformation to allow free movements of grains. [source] RESERVOIR POTENTIAL OF A LACUSTRINE MIXED CARBONATE / SILICICLASTIC GAS RESERVOIR: THE LOWER TRIASSIC ROGENSTEIN IN THE NETHERLANDSJOURNAL OF PETROLEUM GEOLOGY, Issue 1 2008D. Palermo The Lower Triassic Rogenstein Member of the Buntsandstein Formation produces gas at the De Wijk and Wanneperveen fields, NE Netherlands and consists mainly of claystones with intercalated oolitic limestone beds. The excellent reservoir properties of the oolites (,= 20-30%; k = 5-4000 mD) are predominantly controlled by depositional facies. Oolitic limestones are interpreted as the storm and wave deposits of a shallow, desert lake located in the Central European Buntsandstein Basin. The vertical sequence of lithofacies in the Rogenstein Member indicates cyclic changes of relative lake level. The reservoir rock is vertically arranged in a three-fold hierarchy of cycles, recognised both in cores and wireline logs. These cycles are a key to understanding the distribution of reservoir facies, and are used as the basis for a high-resolution sequence stratigraphic correlation of the reservoir units. Slight regional-scale thickness variations of the Rogenstein Member (in the order of tens of metres) are interpreted as the effects of differential subsidence associated with the inherited Palaeozoic structural framework. The depositional basin can be subdivided into subtle palaeo-highs and -lows which controlled facies distribution during Rogenstein deposition. Oolitic limestones show their greatest lateral extent and thickest development in the Middle Rogenstein during large-scale maximum flooding. Potential reservoir rocks (decimetre to metres thick) are present in the NE Netherlands, in particular in the Lauwerszee Trough and the Lower Saxony Basin, where abundant gas shows of 200 - 4000 ppm CH4 have been recorded. Preserved primary porosity is interpreted to be a result of rapid burial in subtle depositional palaeo-lows in this area. The thickest, amalgamated oolite intervals (tens of metres thick) occur in the eastern part of the Central Netherlands Basin. Because of poor reservoir properties, other areas appear to be less promising in terms of Rogenstein exploration potential. [source] TIMING AND MODES OF DEFORMATION IN THE WESTERN SICILIAN THRUST SYSTEM, SOUTHERN ITALYJOURNAL OF PETROLEUM GEOLOGY, Issue 2 2001L. Tortorici Imbricate units in the western Sicilian fold-and-thrust belt originated on the southern continental margin of Neotethys, and were deformed during the Neogene-Recent in response to convergence between the African and European Plates. Neogene-Pleistocene synorogenic sediments, deposited in flexural foredeeps and satellite piggy-back basins, contain a record of the belt's evolution. Progressive migration of the thrust front southwards into the foreland has been documented, beginning in the Tortonian and continuing to the present-day particularly in western parts of the belt. In the eastern part, activity on Quaternary strike-slip fault zones has produced asymmetric flower structures and other interference structures. In this paper, we present two regional sections across the western Sicilian foreland-thrust belt system. These structural cross-sections extend down as far as the top of the Hercynian basement and integrate our field observations with previously-acquired well log, magnetic and seismic data. We show that complex interactions between the foreland-migrating thrust belt, which developed between the Late Miocene and the Pleistocene, and Pleistocene strike-slip faults led to the development of structural traps which constitute potential targets for hydrocarbon exploration. [source] Post-impact structural crater modification due to sediment loading: An overlooked processMETEORITICS & PLANETARY SCIENCE, Issue 11 2007Filippos Tsikalas The analysis demonstrates that the geometry and the structural and stratigraphic relations of post-impact strata provide information about the amplitude, the spatial distribution, and the mode of post-impact deformation. Reconstruction of the original morphology and structure for the Mjølnir, Chicxulub, and Bosumtwi craters demonstrates the long-term subsidence and differential compaction that takes place between the crater and the outside platform region, and laterally within the crater structure. At Mjølnir, the central high developed as a prominent feature during post-impact burial, the height of the peak ring was enhanced, and the cumulative throw on the rim faults was increased. The original Chicxulub crater exhibited considerably less prominent peak-ring and inner-ring/crater-rim features than the present crater. The original relief of the peak ring was on the order of 420,570 m (currently 535,575 m); the relief on the inner ring/crater rim was 300,450 m (currently ,700 m). The original Bosumtwi crater exhibited a central uplift/high whose structural relief increased during burial (current height 101,110 m, in contrast to the original height of 85,110 m), whereas the surrounding western part of the annular trough was subdued more that the eastern part, exhibiting original depths of 43,68 m (currently 46 m) and 49,55 m (currently 50 m), respectively. Furthermore, a quantitative model for the porosity change caused by the Chesapeake Bay impact was developed utilizing the modeled density distribution. The model shows that, compared with the surrounding platform, the porosity increased immediately after impact up to 8.5% in the collapsed and brecciated crater center (currently +6% due to post-impact compaction). In contrast, porosity decreased by 2,3% (currently ,3 to ,4.5% due to post-impact compaction) in the peak-ring region. The lateral variations in porosity at Chesapeake Bay crater are compatible with similar porosity variations at Mjølnir crater, and are considered to be responsible for the moderate Chesapeake Bay gravity signature (annular low of ,8 mGal instead of ,15 mGal). The analysis shows that the reconstructions and the long-term alterations due to post-impact burial are closely related to the impact-disturbed target-rock volume and a brecciated region of laterally varying thickness and depth-varying physical properties. The study further shows that several crater morphological and structural parameters are prone to post-impact burial modification and are either exaggerated or subdued during post-impact burial. Preliminary correction factors are established based on the integrated reconstruction and post-impact deformation analysis. The crater morphological and structural parameters, corrected from post-impact loading and modification effects, can be used to better constrain cratering scaling law estimates and impact-related consequences. [source] Mitochondrial phylogeography of the moor frog, Rana arvalisMOLECULAR ECOLOGY, Issue 6 2004W. Babik Abstract The moor frog Rana arvalis is a lowland species with a broad Eurasiatic distribution, from arctic tundra through forest to the steppe zone. Its present-day range suggests that glacial refugia of this frog were located outside southern European peninsulas. We studied the species-wide phylogeographical pattern using sequence variation in a 682 base pairs fragment of mtDNA cytochrome b gene; 223 individuals from 73 localities were analysed. Two main clades, A and B, differing by c. 3.6% sequence divergence were detected. The A clade is further subdivided into two subclades, AI and AII differing by 1.0%. All three lineages are present in the Carpathian Basin (CB), whereas the rest of the species range, including huge expanses of Eurasian lowlands, are inhabited solely by the AI lineage. We infer that AII and B lineages survived several glacial cycles in the CB but did not expand, at least in the present interglacial, to the north. The geographical distribution and genealogical relationships between haplotypes from the AI lineage indicate that this group had two glacial refugia, one located in the eastern part of the CB and the other probably in southern Russia. Populations from both refugia contributed to the colonization of the western part of the range, whereas the eastern part was colonized from the eastern refugium only. The effective population size as evidenced by ,ML is an order of magnitude higher in the AI lineage than in the AII and B lineages. Demographic expansion was detected in all three lineages. [source] Degradation of permafrost in the Xing'anling Mountains, northeastern ChinaPERMAFROST AND PERIGLACIAL PROCESSES, Issue 3 2007Huijun Jin Abstract Permafrost in the Da and Xiao Xing'anling Mountains in northeastern China is warm, thin and sensitive to climatic warming. In the 1970s, the southern limit of permafrost (SLP) was empirically correlated to the ,1 to 0°C isotherms of mean annual air temperature (MAAT) in the western part of the Da Xing'anling Mountains, to about 0°C in the northern part of the Songnen Plain, and to 0 to +1°C in the eastern part of the Xiao Xing'anling Mountains. Climate warming and deforestation have led to permafrost degradation as shown by deepening of the active layer, thinning permafrost, rising ground temperatures, expanding taliks and the disappearance of permafrost patches. The present position of the SLP was estimated using the ,1.0 to +1.0°C MAAT isotherms for 1991,2000. Compared to the SLP in the 1970s, areas of sporadic discontinuous and isolated patchy permafrost have decreased by 90,000,100,000,km2, or 35,37% of their total areal extent (260,000,270,000,km2) in the 1970s. Recent field observations along the Hei'he to Bei'an Highway, the proposed Mo'he to Daqing Crude Oil Pipeline route and the Hai'lar to Daqing Highway confirm these changes. Continuing northward shifting of the SLP is likely to occur during the next 40,50 years under a warming of 1.0,1.5 °C, reducing the permafrost areal extent to an estimated 35% of that in the 1970s and 1980s. Copyright © 2007 John Wiley & Sons, Ltd. [source] Down syndrome livebirth rate in the eastern part of Switzerland between 1980 and 1996 stays constant in spite of growing numbers of prenatally diagnosed and subsequently terminated casesPRENATAL DIAGNOSIS, Issue 9 2002Michael Mutter No abstract is available for this article. [source] Estimates of population size of white-chinned petrels and grey petrels at Kerguelen Islands and sensitivity to fisheriesANIMAL CONSERVATION, Issue 3 2009C. Barbraud Abstract White-chinned petrels Procellaria aequinoctialis and grey petrels Procellaria cinerea are among the most frequently killed seabird species by accidental bycatch, and both species have received strong conservation concern. Data on population size are required to evaluate the impact of bycatch and to establish management plans. We estimated the population size of both species at Kerguelen, Southern Indian Ocean, from 2004 to 2006 by explicitly taking into account detection probability of burrows using distance sampling and burrow occupancy. A total of 31 line-transects were distributed across the eastern part of Kerguelen, representing a total length of 566 km. Detectability was low (from 0.19 to 0.54 for white-chinned petrels, 0.58 for grey petrels). Burrow densities varied from 1.37±0.67 to 25.77±5.23 burrows ha,1 for white-chinned petrels and was 2.78±0.79 burrows ha,1 for grey petrels. For white-chinned petrels, these densities were extrapolated to the entire surface area of vegetation and there were 234 000 (186 000,297 000) active burrows on Kerguelen. For grey petrels, the number of active burrows for the eastern part of Kerguelen was 3400 (1900,5600). Based on these estimates, the potential biological removal method suggests that the additional mortality on birds caused by the fisheries operating around Kerguelen can be considered a serious threat for the species at least at the regional scale of the Southern Indian Ocean, especially for grey petrels. [source] Male-mediated introgression of Bos indicus genes into Argentine and Bolivian Creole cattle breedsANIMAL GENETICS, Issue 5 2000G Giovambattista The geographic distribution and frequency of Bos taurus and Bos indicus Y chromosome haplotypes amongst Argentine and Bolivian Creole cattle breeds were studied, using cytogenetic and molecular genetic techniques. A complete correspondence between Y chromosome morphology and the haplotype of the Y-linked microsatellite marker INRA 124 was found in all males examined. The taurine and indicine haplotypes were detected in 85·7 and 14·3% of the males studied, respectively, although these frequencies varied amongst the different breeds examined. The geographic distribution of this polymorphism suggests a pattern of zebu introgression in South America. The highest frequencies of the Zebu Y-chromosome are found in Brazilian populations (43,90%), in the eastern part of the continent, while it is absent in the southermost breeds from Uruguay and Argentina. Bolivan breeds, at the centre of the continent, exhibit intermediate values (17,41%). This east/west and north/south gradient of male Zebu introgression could be explained by historical events and environmental factors. [source] GPR microwave tomography for diagnostic analysis of archaeological sites: the case of a highway construction in Pontecagnano (Southern Italy)ARCHAEOLOGICAL PROSPECTION, Issue 3 2009R. Castaldo Abstract Interpretation of ground-penetrating radar (GPR) data usually involves data processing similar to that used for seismic data analysis, including also migration techniques. Alternatively, in the past few years, microwave tomographic approaches exploiting more accurate models of the electromagnetic scattering have gained interest, owing to their capability of providing accurate results and stable images. Within this framework, this paper deals with the application of a microwave tomography approach, based on the Born Approximation and working in the frequency domain. The case study is a survey performed during the realization of the third lane of the most important highway in southern Italy (the Salerno-Reggio Calabria, near Pontecagnano, Italy). It is shown that such an inversion approach produces well-focused images, from which buried structures can be more easily identified by comparison to traditional radar images. Moreover, the visualization of the reconstruction results is further enhanced through a three-dimensional volumetric rendering of the surveyed region, simply achieved by staggering the reconstructed GPR two-dimensional profiles. By means of this rendering it is possible to follow the spatial continuity of the buried structures in the subsurface thus obtaining a very effective geometrical characterization. The results are very useful in our case where, due to important civil engineering works, a fast diagnosis of the archaeological situation was needed. The quality of our GPR data modelling was confirmed by a test excavation, where a corner of a building and the eastern part of another house, with its courtyard, were found at the depth and horizontal position suggested by our interpretation. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||