bluuebunny/crossref_metadata_2025 huggingface dataset:
The politics of memory. Resistance as a collective myth in post-war France, Belgium and the
Netherlands, 1945–1965
Authors: LAGROU PIETER
Published: December 2003

France, Belgium and the Netherlands faced the same fundamental challenge in 1945. In spite of differences in institutional setting, chronology or demography, their experience of Nazi occupation had been traumatizing and humiliating. Their national reconstruction required a self-confident image of the recent past. Nonetheless, the contours of the policies of memory pursued in the three countries diverged in a striking measure. In the Netherlands, post-war governments deliberately constructed a forced national consensus around the myth of a unanimous resistance, at the expense of veterans’ movements and all forms of associative memory. However, the latter dominated the commemorations in France and Belgium, continuing a post-1918 tradition. The conflicts between different categories of war veterans and victims and between different political families characterized the conflicting memories in these two countries. Rather than a monolithic resistance myth, different memories of Nazi persecution were rivals for public attention. In France, neither de Gaulle nor the Communist party succeeded in monopolizing the heroic legacy of the resistance. In Belgium, the Royal question, the left–right divide and subsequently the regional tensions between French and Dutch speakers, estranged part of opinion from the memory of the resistance and even ended up favouring, in some quarters, the rehabilitation of collaboration with the Nazi occupier.
Fatigue and Attention Following Traumatic Brain Injury
Authors: Ponsford Jennie , Ziino Carlo
Published: December 2003

Abstract: Numerous outcome studies have indicated that fatigue is one of the most universal and persistent problems reported following traumatic brain injury (TBI). The present study will examine fatigue following TBI, as reported subjectively, its relationship with demographic and injury-related factors, depression and anxiety, as well as its relationship with measures of attention and mental speed. In a group of 28 TBI participants and 28 controls, TBI participants reported significantly greater fatigue on the Fatigue Severity Scale. Fatigue was greater in those who were older, more educated and a longer time post-injury. Depression was also associated with high fatigue, but not in all cases. The relationship of subjective fatigue with mental speed and attention will be the next focus of this study.
The effectiveness of a coping-focused prevention approach: A two-year longitudinal study
Authors: Bodenmann Guy , Perrez Meinrad , Cina Annette , Widmer Kathrin
Published: December 2003

This article focuses upon a new preventive approach designed to improve personal stress management skills. The Coping Enhancement Training (CET) is derived from the Couples Coping Enhancement Training (CCET) and encompasses both an individual and a dyadic aspect. In this study, only the individual element is described. The training is based upon the transactional stress concepts of Lazarus and his coworkers and the further development of this approach by Perrez and Reicherts (1992). Personal coping skills are practiced over a six-hour period by means of theoretical, diagnostic and practical work. This article presents the rationale and content of the program, as well as data concerning the effectiveness of this approach after a period of two years. The data shows that subjects participating in the program displayed better individual coping skills (e.g. active problem-solving and positive self-verbalization) after the training and that they relied upon dysfunctional coping strategies (e.g. rumination and blaming strategies) less often even after two years.
Regulation of emotion and psychological symptoms in people with spinal cord injury
Authors: Znoj Hans J. , Lude Peter
Published: December 2003

This cross-sectional study examined the contribution of regulation of emotion on depression, symptoms of traumatic and general distress, perceived disability, and somatic symptoms following spinal cord injury. Depressed and non-depressed participants (N = 264, mean age = 46 years) differed in their use of adaptive and maladaptive ways of regulating emotions. In addition to somatic symptoms and symptoms of traumatic stress, maladaptive emotional regulation (avoidance and distortion of awareness) accounted for 8% of the total variance of depression. It is concluded that adaptive and maladaptive ways of regulating emotions are important factors in dealing with negative feelings. Regulation of emotion appears to influence perceived disability mainly via depression. Limitations of the study and implications for rehabilitation are discussed.
Störungskonzepte für psychische Probleme bei Jugendlichen
Authors: Schmidt A. , Schneiders M. , Döpfner M. , Lehmkuhl G.
Published: December 2003

Zusammenfassung: Fragestellung: Der erste Fragebogen zu Störungskonzepten bei psychischen Problemen bei Jugendlichen (SPPJ) wurde auf Grundlage der Attributionstheorie (Health Locus of Control) entwickelt und an 54 psychisch erkrankten, überwiegend stationären Jugendlichen validiert. Methode: Konsistenzanalyse, Korrelation mit dem Test zu Kontrollüberzeugungen bei Krankheit und Gesundheit (KKG-Test), Interkorrelation der Skalen, Korrelation mit den Frankfurter Selbstkonzeptskalen, der Therapiekooperation und -prognose. Ergebnisse: Der SPPJ unterscheidet zwischen Ursachenattributionen und Kontrollüberzeugungen und zeigt sich als reliables Messinstrument, das mit der Aussage allgemeiner Messinstrumente (KKG-Test) befriedigende Korrelationen eingeht. Entgegen den Erwartungen zeigt sich keine signifikant positive Korrelation zwischen internaler Kontrollüberzeugung und Kooperation und Prognose. Eine external-personenbezogene Ursachenzuschreibung wirkt sich negativ auf die Kooperation, eine external-personenbezogene Kontrollüberzeugung positiv auf die Kooperation aus. Schlussfolgerungen: In der Untersuchung von Störungskonzepten stellt das Selbsturteil Jugendlicher in Bezug auf psychische Probleme eine eigene Entität dar. Jugendliche, die weniger dazu neigen, andere Menschen als Ursache für ihr Problem anzusehen und die anderen Personen Behandlungskompetenz zuschreiben, besitzen wahrscheinlich die höhere Interventionsakzeptanz. Weitere Forschung auf diesem Gebiet ist notwendig. Auf der Grundlage der Attributionstheorie muss hierbei auch dem erheblichen Unterschied zwischen Ursachen- und Behandlungsüberzeugungen stärker Rechnung getragen werden.
Rett-Syndrom: Individuelle Variabilität in Entwicklungs- und Verhaltensmerkmalen und psychosoziale Belastung
Authors: Sarimski Klaus
Published: December 2003

Zusammenfassung: Fragestellung: Das Rett-Syndrom ist eine schwere neurologische Entwicklungsstörung in Folge einer genetischen Mutation auf dem langen Arm des X-Chromosoms (Xq28), die u.a. mit dem Verlust zielgerichteten Handgebrauchs, sprachlicher Fähigkeiten und mit spezifischen Verhaltensmerkmalen einhergeht. Methode: Aus einer Elternbefragung an 83 Mädchen werden Daten zu vorsprachlichen Fähigkeiten (Pre-Verbal Communication Schedule), zu Besonderheiten des Verhaltens und emotionalen Ausdrucks (Rett Syndrome Behavior Questionnaire) und zur psychosozialen Belastung der Mütter (Handicap-related Problems for Parents Inventory) mitgeteilt. Ergebnisse: Die individuelle Variabilität in den Entwicklungs- und Verhaltensmerkmalen ist beträchtlich und vom Alter der Mädchen unabhängig. Die mütterliche Belastung variiert mit dem Grad an Stimmungsschwankungen, ängstlichen Reaktionen und nächtlichen Auffälligkeiten der Töchter. Schlussfolgerung: Für die Diagnostik und Beratung der betroffenen Familien werden diskutiert.
Schlafstörungen bei hyperkinetischen Kindern - Zusammenhänge zu Arousalstörungen, differentialdiagnostische Abgrenzungen und Komorbiditäten
Authors: Frölich J. , Lehmkuhl G. , Wiater A.
Published: December 2003

Zusammenfassung: Fragestellung: Schlafstörungen stellen ein häufiges Begleitphänomen bei hyperkinetischen Störungen und Aufmerksamkeitsdefizit-Hyperaktivitätsstörungen (ADHS) dar. Zugleich besteht allerdings weitgehende Unklarheit darüber, wie häufig sie begleitend auftreten, ob sie gegenüber anderen psychopathologischen Störungsbildern spezifische Charakteristika aufweisen und ob sie in einem pathogenetischen Zusammenhang zu der Entwicklung der Kernsymptome der ADHS stehen. Methoden: Des Weiteren liegen nur wenige überschneidende Befunde zu internistischen und neurologischen Krankheitsbildern wie dem Schlafapnoesyndrom und den Restless-Legs Syndrom vor, die in der Differentialdiagnostik der ADHS zu berücksichtigen sind. Resultate: Zusammenfassend ist die aktuelle Befundlage vielfältig, aber nicht zusammenhängend. In unserer Übersichtsarbeit werden die vorliegenden Forschungsergebnisse detailliert dargelegt. Schlussfolgerung: Abschließend werden Perspektiven für Fragestellungen zukünftiger empirischer Arbeiten formuliert, nämlich vor allem 1. die Bedeutung eines möglichen pathogentischen Einflusses von Schlafstörungen bei der ADHS aufzuklären und 2. differentialdiagnostisch bedeutsame Zusammenhänge zu schlafbezogenen Atmungsstörungen (SBAS) zu untersuchen.
Propagation of climatic events on ocean stratification, marine biology, and CO2: Case studies over the 1979–1999 period
Authors: Le Quéré Corinne , Aumont Olivier , Monfray Patrick , Orr James
Published: December 2003

We investigate the propagation of climatic events on ocean stratification, marine biology, and CO2 using a large‐scale ocean general circulation model coupled to a simple biogeochemical model of plankton dynamics and the carbon cycle. The model was forced with satellite and reanalysis fields during 1979–1999. We focus on three climatic events: (1) the North Atlantic Oscillation, (2) El Niño events, and (3) the Antarctic Circumpolar Wave. Such climatic events caused variability in ocean stratification, approximated by the mixing depth (MD), from ±20 m in the subtropics to ±100 s of meters at high latitudes. In the subtropics, deepening of the MD resupplied nutrient‐impoverished surface waters and increased marine biomass by 20–100%. In contrast, at high latitudes, shoaling of the MD lengthened the growing season (i.e., the length of time that light is available for plankton growth) and increased marine biomass by 10–20%. Variability in marine biology reached global peak‐to‐peak values of ±0.01 mg m−3 for surface chl a, ±3.4 Pg C yr−1 for primary production, and ±0.3 Pg C yr−1 for export production and its contribution to CO2 fluxes. Our model results suggest that changes in ocean stratification driven by short‐term climatic events could be used to understand and quantify the feedbacks from marine biology to CO2 and climate.
Seasonal and ENSO variability in global ocean phytoplankton chlorophyll derived from 4 years of SeaWiFS measurements
Authors: Yoder James A. , Kennelly Maureen A.
Published: December 2003

The 4‐year, calibrated SeaWiFS data set provides a means to determine seasonal and other sources of phytoplankton variability on global scales, which is an important component of the total variability associated with ocean biological and biogeochemical processes. We used empirical orthogonal function (EOF) analysis on a 4‐year time series of global SeaWiFS chlorophyll a measurements to quantify the major seasonal (as well as the late El Niño and La Niña phase of the 1997–1998 ENSO) signals in phytoplankton biomass between 50°S and 50°N, and then a second analysis to quantify summer patterns at higher latitudes. Our results help place regional satellite chlorophyll variability within a global perspective. Among the effects we resolved are a 6‐month phase shift in maximum chlorophyll a concentrations between subtropical (winter peaks) and subpolar (spring‐summer peaks) waters, greater seasonal range at high latitudes in the Atlantic compared to the Pacific, an interesting phasing between spring and fall biomass peaks at high latitudes in both hemispheres, and the effects of the 1998 portion of the 1997–1998 ENSO cycle in the tropics. Our EOF results show that dominant seasonal and ENSO effects are captured in the first six of a possible 184 modes, which explain 67% of the total temporal variability associated with the global mean phytoplankton chlorophyll pattern in our smoothed data set. The results also show that the time (seasonal)/space (zonal) patterns between the ocean basins and between the hemispheres are similar, albeit with some key differences. Finally, the dominant global patterns are consistent with the results of ocean models of seasonal dynamics based on seasonal changes to the heating and cooling (stratification/destratification) cycles of the upper ocean.
Constraints on the 232Th/238U ratio (κ) of the continental crust
Authors: Paul D. , White W. M. , Turcotte D. L.
Published: December 2003

This study examines constraints on the 232Th/238U ratio of the continental crust (κC) imposed by heat flow, Th‐U systematics and Pb isotope ratios. The 232Th/238U ratio of the depleted upper mantle (κUM) as sampled by mid‐ocean ridge basalt is well‐constrained to be 2.5 ± 0.1. The 232Th/238U ratio of the lower mantle (κLM) can be constrained as follows. Oceanic island basalts (OIB) have average κ of 3.78. If OIB are derived from mantle plumes and if plumes are representative of the lower mantle, then κLM ≤ 3.78. Alternatively, if the lower mantle is “primitive”, then κLM is similar to the chondritic 232Th/238U ratio of κS = 4 ± 0.2. Mass balance calculations assuming κUM = 2.5, and κLM ≤ 4 with heat production constraints suggest that κC is in the range 5–6. Further support for κC substantially greater than 4 comes from the Pb isotopic composition of the continental crust. We estimate the 208Pb/204Pb of the lower continental crust to be 37.36 to 37.84 and the 208Pb*/206Pb* ratio of the total continental crust to be 1.046 to 1.059, which corresponds to a time‐integrated 232Th/238U ratio (κC(Pb)) of 4.25 − 4.30. A four‐reservoir (upper and lower continental crust, depleted upper mantle, and primitive lower mantle) forward transport model of Pb isotope evolution that reproduces the difference in κUM and κUM(Pb) values in the depleted mantle suggests that to achieve a κC(Pb) of 4.25, the present 232Th/238U ratio in the crust (κC) must be ≈5. Thus several lines of evidence converge on a value κC of around 5 or slightly higher.
Further refinements to models for the bulk‐skin sea surface temperature difference
Authors: Castro S. L. , Wick G. A. , Emery W. J.
Published: December 2003

The bulk‐skin sea surface temperature difference, ΔT, has an important impact on both satellite remote sensing and air‐sea interaction studies. Extensive in situ data from diverse environmental conditions are used to explore the dependence of ΔT on environmental conditions and to evaluate and refine models for ΔT during nighttime. Data from 10 different cruises covering large ranges of latitudes and seasons in both the Atlantic and Pacific Oceans were accumulated and processed consistently. Comparison of the measured ΔT values with the environmental parameters generally confirmed an observed tendency for ΔT to approach a near‐constant value as the wind speed increases but also demonstrated a dependence of the residual variability on the net heat flux. To adequately predict ΔT, it is necessary to use a model that incorporates a dependence on all these parameters. Existing models for ΔT are all shown to be unable to fully reproduce the observed variability under all conditions. To improve the ability to predict ΔT, a new surface renewal‐type model was developed incorporating four additional physical processes. New expressions are proposed for renewal timescales, accounting for microscale and large‐scale wave breaking, the effects of capillary waves, and a saturated shear regime. To incorporate the simultaneous effects of multiple physical processes within the sampling region and period, the modeled ΔT is computed as a weighted combination of the contributions of the relevant regimes. An initial specification of the weights, derived from the observed ΔT values and environmental parameters, demonstrates that a suitable combination of the timescales can reproduce the majority of the observed variability in ΔT. A second, objective determination of the weights, using conjugate gradient minimization, produces slightly poorer results but demonstrates that the model can be used in a prognostic manner to significantly improve upon the existing predictions of ΔT.
Linking horizontal and vertical transports of biomass fire emissions to the Tropical Atlantic Ozone Paradox during the Northern Hemisphere winter season: 1999
Authors: Jenkins Gregory S. , Ryu Jung‐Hee , Thompson Anne M. , Witte Jacquelyn C.
Published: December 2003

The horizontal and vertical transport of biomass fire emissions in West Africa for January 1999, are examined using all available data including wind, fire, aerosol, precipitation, lightning and outgoing longwave radiation. Ozonesonde data from the Aerosols99 Trans‐Atlantic cruise are also included with rain and wind analyses. The results here support earlier studies that ozone and ozone precursors associated with biomass burning are confined to the lower troposphere primarily due to the lack of deep convection over land areas. Ozone and its precursors are horizontally transported equatorward or toward the west by winds in the 1000–700 hPa layers. However, rising adiabatic motions associated with the diurnal evolution of the West African planetary boundary layer can transport ozone and its precursors vertically into the free troposphere above the marine boundary layer. Moreover, lightning from South America, Central Africa and mesoscale convective systems in the Gulf of Guinea can lead to elevated ozone mixing ratios in the middle and upper troposphere of the tropical south Atlantic. The results presented here shed light of the proposed ozone paradox during Northern Hemisphere winter.
A model for studies of tropospheric ozone and nonmethane hydrocarbons: Model evaluation of ozone‐related species
Authors: von Kuhlmann Rolf , Lawrence Mark G. , Crutzen Paul J. , Rasch Philip J.
Published: December 2003

A global three‐dimensional model for studies of the tropospheric chemistry of HOx, ozone, and their precursors is thoroughly evaluated with available observations of 15 species from surface stations and/or aircraft campaigns. The effect of grid‐resolution was studied by comparing the measurements to model runs at a high (∼1.9° × 1.9°) and a reduced resolution. This study is a follow‐up to a previous paper where the model was described and results for ozone were discussed. A statistical analysis of the complete comparison of each species is also presented in order to serve as a quantitative baseline for future evaluations. The seasonality and magnitude of the CO abundance is well simulated except for an overestimate of up to 20 nmol/mol in southern low latitudes. The tropospheric mean methane lifetime is calculated to be 8.7 and 9.1 years for the high‐ and low‐resolution run, respectively, in agreement with recent estimates. Industrial emissions of alkanes from North America appear to be too low in the current data set. Indications for a biogenic source of propane were found by comparing with measurements over the Amazon rain forest. Alkene emissions from oceans are underestimated in the model indicating that they are higher than previous studies suggested. Nitrogen species are mostly reproduced within a factor of 2 or better, but a general bias to underestimate HNO3 and to overpredict peroxyacetyl nitrate (PAN), especially in remote regions could also be found. NO was well simulated in the lower and mid troposphere, but significantly understimated in the upper troposphere. A sensitivity run shows that studies are needed to better constrain the rate constants for the thermal equilibrium of PAN. Acetone is often underestimated indicating that additional wide‐spread sources, likely oceanic, are present. The comparison with other oxygenated species (acetaldehyde, methanol, formic and acetic acid) indicates severe gaps in our understanding of the present budgets of these species. In particular the underestimate of acetaldehyde implies large missing sources (order 100 Tg/yr) of this compound.
Global modeling of the fate of nitrogen from point and nonpoint sources in soils, groundwater, and surface water
Authors: Van Drecht G. , Bouwman A. F. , Knoop J. M. , Beusen A. H. W. , Meinardi C. R.
Published: December 2003

We present a global model that describes the fate of nitrogen (N) from point and nonpoint sources in the hydrological system up to the river mouths at the 0.5° by 0.5° spatial and annual temporal resolution. Estimates for point sources are based on population densities, per capita human N emissions, and data on sanitation coverage and wastewater treatment. For nonpoint sources, we use spatial information on land use, climate, hydrology, geology, and soils, combined with data on N inputs (fertilizers and animal manure, biological N fixation, and atmospheric deposition), and outputs (N removal in harvested agricultural products, ammonia emissions). Denitrification in the root zone and nitrate leaching to groundwater are calculated with a model that combines the effect of temperature, crop type, soil properties, and hydrological conditions. The nitrate concentration of the outflow for shallow and deep groundwater layers is based on historical inputs of fertilizer N and the effects of residence time and denitrification. In‐stream N retention is based on a global estimate of 30% of the N discharged to surface water. Calculated and reported total N concentrations of discharge near the river outlet agree fairly well. However, our model systematically overestimates total N concentrations for river basins with mean annual temperature >0°C.
Decadal accumulation of anthropogenic CO2 in the Southern Ocean: A comparison of CFC‐age derived estimates to multiple‐linear regression estimates
Authors: Matear R. J. , McNeil B. I.
Published: December 2003

The decadal accumulation of anthropogenic CO2 from 1968 to 1996 was estimated from CFC‐ages along three WOCE sections (SR3, P14, P15) in the Southern Ocean. We explore the validity of the method in the Southern Ocean by directly comparing the CFC‐age derived estimates to values obtained using a multiparametric linear regression method over the same period. The agreement in anthropogenic CO2 accumulation between the two independent methods was very good (less than ±8%) for waters younger than 30 years. We found waters older than 30 years to significantly overestimate the decadal accumulation when using the CFC‐age method. This is mainly due to significant mixing biases when using CFCs to infer ages for these older waters [Sonnerup, 2001]. The CFC‐age method assumes a steady state circulation. CFC‐11 variations on interannual timescales have been found to be relatively large [Doney et al., 1998]. To test the biases from interannual variations, we compare CFC data on the SR3 section for two different years (1991 and 1994). Although we found large differences in the estimated CFC‐11 ages (∼8 years) from the two cruises, these differences had little impact on the decadal accumulation of anthropogenic CO2 estimated by the CFC‐age method. We found the CFC‐age method to be insensitive to interannual variations or non‐ideal “age” biases [Sonnerup, 2001; Haine and Hall, 2002] because of the similar atmospheric histories of CFC‐11 and CO2 from about 1965 to 1993. Our study validates the use of transient tracer ages to infer decadal anthropogenic CO2 accumulations in the Southern Ocean during the 1970s, 1980s, and 1990s. The application of other transient tracers to determine ages will be needed to improve the estimates of anthropogenic CO2 accumulation and uptake by the Southern Ocean for both now and into the future.
Morphology and segmentation of the western Galápagos Spreading Center, 90.5°–98°W: Plume‐ridge interaction at an intermediate spreading ridge
Authors: Sinton John , Detrick Robert , Canales J. Pablo , Ito Garrett , Behn Mark
Published: December 2003

Complete multibeam bathymetric coverage of the western Galápagos Spreading Center (GSC) between 90.5°W and 98°W reveals the fine‐scale morphology, segmentation and influence of the Galápagos hot spot on this intermediate spreading ridge. The western GSC comprises three morphologically defined provinces: A Western Province, located farthest from the Galápagos hot spot west of 95°30′W, is characterized by an axial deep, rift valley morphology with individual, overlapping, E‐W striking segments separated by non‐transform offsets; A Middle Province, between the propagating rift tips at 93°15′W and 95°30′W, with transitional axial morphology strikes ∼276°; An Eastern Province, closest to the Galápagos hot spot between the ∼90°50′W Galápagos Transform and 93°15′W, with an axial high morphology generally less than 1800 m deep, strikes ∼280°. At a finer scale, the axial region consists of 32 individual segments defined on the basis of smaller, mainly <2 km, offsets. These offsets mainly step left in the Western and Middle Provinces, and right in the Eastern Province. Glass compositions indicate that the GSC is segmented magmatically into 8 broad regions, with Mg # generally decreasing to the west within each region. Striking differences in bathymetric and lava fractionation patterns between the propagating rifts with tips at 93°15′W and 95°30′W reflect lower overall magma supply and larger offset distance at the latter. The structure of the Eastern Province is complicated by the intersection of a series of volcanic lineaments that appear to radiate away from a point located on the northern edge of the Galápagos platform, close to the southern limit of the Galápagos Fracture Zone. Where these lineaments intersect the GSC, the ridge axis is displaced to the south through a series of overlapping spreading centers (OSCs); abandoned OSC limbs lie even farther south. We propose that southward displacement of the axis is promoted during intermittent times of increased plume activity, when lithospheric zones of weakness become volcanically active. Following cessation of the increased plume activity, the axis straightens by decapitating southernmost OSC limbs during short‐lived propagation events. This process contributes to the number of right stepping offsets in the Eastern Province.
Tropospheric methane retrieved from ground‐based near‐IR solar absorption spectra
Authors: Washenfelder R. A. , Wennberg P. O. , Toon G. C.
Published: December 2003

High‐resolution near‐infrared solar absorption spectra recorded between 1977 and 1995 at the Kitt Peak National Solar Observatory are analyzed to retrieve column abundances of methane (CH4), hydrogen fluoride (HF), and oxygen (O2). Employing a stratospheric “slope equilibrium” relationship between CH4 and HF, the varying contribution of stratospheric CH4 to the total column is inferred. Variations in the CH4 column due to changes in surface pressure are determined from the O2 column abundances. By this technique, CH4 tropospheric volume mixing ratios are determined with a precision of ∼0.5%. These display behavior similar to Mauna Loa in situ surface measurements, with a seasonal peak‐to‐peak amplitude of approximately 30 ppbv and a nearly linear increase between 1977 and 1983 of 18.0 ± 0.8 ppbv yr−1, slowing significantly after 1990.
Contribution to the seismotectonics of Eastern Turkey from moderate and small size events
Authors: Örgülü Gonca , Aktar Mustafa , Türkelli Niyazi , Sandvol Eric , Barazangi Muawia
Published: December 2003

Source properties of small‐to‐moderate magnitude events in eastern Turkey were studied using high quality waveform data produced by the Eastern Turkey Seismic Experiment (ETSE). A data set of fault plane solutions was obtained for 134 earthquakes using the regional moment tensor inversion technique for 34 events with magnitude 3.7 and above, and first motion analysis for 115 earthquakes with magnitude 3.0 and higher (for 15 events both techniques were used). Most of the events studied had strike slip mechanisms in agreement with nearby local fault structures. Reverse mechanisms were more scarce and were restricted to certain areas, such as in the eastern Anatolian plateau and southwest of the Karliova junction along the Arabian plate boundary. Our results indicate a difference in the deformational style east and west of the Karliova junction which results in internal deformation in the east and westward extrusion of the Anatolian plate with no or very little internal deformation in the west. Our results also suggest that in eastern Turkey, most of the collision is taken up by strike slip faults of varying types and sizes, suggesting that the northward convergence of Arabia is being accommodated by escape tectonics. Compressive features, such as thrust faulting, which were obviously the primary faulting during the earliest stages of continental collision, are still active but are of lesser importance.
Planetary‐scale inertio gravity waves in the Mesosphere
Authors: Mayr H. G. , Mengel J. G. , Talaat E. R. , Porter H. S. , Chan K. L.
Published: December 2003

In the polar region of the upper mesosphere, horizontal wind oscillations have been observed with periods around 10 hours. Waves with such periods are generated in our Numerical Spectral Model (NSM), and they are identified as planetary‐scale inertio gravity waves (IGW). These waves have periods between 9 and 11 hours and appear above 70 km in the zonal mean (m = 0), as well as in m = 1 to 4 propagating eastward and westward. They grow in magnitude to altitudes near 100 km and have vertical wavelengths of about 25 km. The m = 1 westward IGWs have the largest amplitudes, up to 30 m/s at the poles. The IGWs occur intermittently but reveal systematic seasonal variations. Their amplitudes generally are largest in late winter and spring. Numerical experiments show that the waves also appear without tidal excitation. Like the planetary waves in the model, the IGWs are produced by instabilities that arise in the mean zonal circulation.
Prodigious sulfur dioxide emissions from Nyamuragira volcano, D.R. Congo
Authors: Carn S. A. , Bluth G. J. S.
Published: December 2003

Nyamuragira (Virunga chain, D.R. Congo) is among Africa's most active volcanoes, but direct observations of its eruptions are rare. From 1978–2002 the Total Ozone Mapping Spectrometer (TOMS) instruments measured SO2 emissions during each of Nyamuragira's 13 most recent eruptions. Due to continuous co‐eruptive SO2 degassing, estimating the total atmospheric SO2 loading resulting from eruptions of Nyamuragira is not straightforward. Using TOMS SO2 plume cross‐sections and model wind profiles we derive eruptive SO2 fluxes and SO2 loss rates for emissions on 19 October 1998 and 6 February 2001, giving peak SO2 fluxes of 0.21 and 0.74 Tg day−1 respectively and loss rates of ∼10−6–10−5 s−1. Based on current data, time‐averaged SO2 emission rates at Nyamuragira are comparable to persistent emitters (Etna, Kilauea), but eruptive fluxes at Nyamuragira are much higher. Considering the alkaline composition of Virunga lavas, eruptive CO2 fluxes could be seven times the SO2 flux.
Solar‐radiation‐maintained glacier recession on Kilimanjaro drawn from combined ice‐radiation geometry modeling
Authors: Mölg Thomas , Hardy Douglas R. , Kaser Georg
Published: December 2003

In the context of investigating modern glacier recession on Kilimanjaro, which began around 1880, this study addresses the glacier regime of the vertical ice walls that typically form the margins of Kilimanjaro's summit glaciers. These walls have suffered a continuous lateral retreat during the twentieth century. To evaluate the role of solar radiation in maintaining glacier recession on Kilimanjaro, a radiation model is applied to an idealized representation of the 1880‐ice cap. The combined process‐based model calculates the spatial extent and geometry of the ice cap for various points in time after 1880. Support for input data and fundamental assumptions are provided by an automatic weather station that has operated on the summit's Northern Icefield since February 2000. Even in a simple climatic scenario only forced with an annual cycle of clouds, the basic evolution in spatial distribution of ice bodies on the summit is modeled well. The Northern and Southern Icefields form in characteristic east‐west orientation, which verifies the basic idea behind the model. Forcing the model with further climate‐related phenomena improves the results. It then additionally reproduces the Eastern Icefield, the third big ice entity on the summit. This study qualitatively demonstrates that solar radiation is the main climatic parameter maintaining modern glacier recession on Kilimanjaro summit, but also suggests that retreat on the inner ice cap margin might have been supported by a secondary energy source. The need for additional field measurements is emphasized in order to better understand the complex processes of glacier‐climate interaction on Kilimanjaro.
Tropical Pacific sea‐surface temperatures and preceding sea level pressure anomalies in the subtropical North Pacific
Authors: Anderson Bruce T.
Published: December 2003

The correspondence of sea‐surface temperature (SST) anomalies to changes in antecedent large‐scale sea level pressure anomalies is investigated using reanalysis data. By statistically examining linearly coupled precursor sea level pressure fields and subsequent SST fields for different lag periods, it is possible to isolate a precursor mode of sea level pressure (SLP) variability in the central subtropical North Pacific that precedes variations in the January–March El Niño/Southern Oscillation (ENSO) by approximately 12–15 months. A sea level pressure index, which captures the important characteristics of this precursor mode of variability, is developed and evaluated. It is shown that both analyzed and observed versions of the index are significantly correlated with the January–March ENSO one year later. The SLP index is then used to examine the evolution of the surface circulation and temperature structures leading up to mature ENSO events. Initially, the January–March subtropical North Pacific SLP anomalies are associated with changes in the intensity of the subtropical trade wind regime over the North Pacific, as well as with SST anomalies over the eastern equatorial Pacific and subtropical central Pacific. In agreement with the correlation statistics associated with the SLP and lagged NINO3.4 indices, both the sea level pressure field and the SST field subsequently develop ENSO‐like structures over the course of the following year. Significant discussion of these results and pertinent areas of future research are provided within the broader context of the ENSO system.
Coherent and incoherent components in near‐nadir radar scattering: Applications to radar sounding of Mars
Authors: Campbell Bruce A. , Shepard Michael K.
Published: December 2003

We examine the relative importance of coherent and incoherent echo components in near‐nadir radar scattering from self‐affine surfaces. The coherent component, important only for observations at small incidence angles (nadir‐looking sounders and altimeters), is a function of both surface roughness and scattering area. Models for the incoherent component require a minimum scattering area for validity; for smaller regions, the radar echo is overestimated. We propose a simple criterion for the horizontal scale that defines this shift in applicable scattering model and show the range of roughness parameters for which MARSIS, SHARAD, and possibly JIMO radar sounder measurements may be modeled using the two approaches.
A radiation belt‐ring current forecasting model
Authors: Zheng Yihua , Fok Mei‐Ching , Khazanov George V.
Published: December 2003

A radiation belt‐ring current (RB‐RC) forecasting model is presented. This model solves the convection‐diffusion equation of plasma distribution in the 10 keV to a few MeV range. There are four major auxiliary components to the RB‐RC model: a global magnetic field model, an electric field model, a plasma sheet model (plasma source), and a radial diffusion model. All four components are driven by solar wind and interplanetary magnetic field conditions. In this paper, a brief description of the model and input parameters is given. This model has been used to simulate several geomagnetic storms. In particular, the effects of the inductive electric field on the evolution of the radiation belt electron fluxes are investigated in detail via a case study of the 12 August 2000 storm. It is found that, in general, the inductive electric field arising from the time‐varying magnetic field can enhance the flux level around geosynchronous orbit during the recovery phase of the storms. The model is validated through comparing the simulation results with the Los Alamos National Laboratory satellite measurements. Further refinement and improvement of the model is also discussed.
Extensive reading online: an overview and evaluation
Authors: Sun Y.C.
Published: December 2003

Abstract This study reports on the design and implementation of a reading program — Extensive Reading Online (ERO) — that aims to offer an online reading platform featuring specific needs for EFL learners in Taiwan. The system includes both teacher and student interfaces. Several reading aids are integrated into the system, such as concordancer help, stage‐by‐stage reading strategy training, and text annotation functions. ERO was integrated into a college level reading class. Results show that students held a positive attitude toward the reading system. Some recommendations for future improvement are also discussed.
Contextual issues in the construction of computer‐based learning programs
Authors: Leung A. C.K.
Published: December 2003

Abstract  Based on the constructive learning theories, particularly constructivism, four contextual issues are identified and discussed in this paper regarding the construction of effective computer‐based learning programs, namely topic selection, authenticity, complexity, and multiple perspectives. These four issues are considered essential for effective learning in terms of learners' participation, reasoning and knowledge construction. After a thorough review and discussion of these issues, a generic conceptual model is built, which shows both the interrelationships among the four issues and the measurement variables of each issue. It is expected that the four contextual issues and the generic model can provide invaluable insights toward research in computer‐based learning, training and many other related fields, and address the needs of practitioners to develop better computer‐based learning programs. Recommendation for further research is also suggested in the end.
An exploratory study of adolescent's perceptions of the Web
Authors: Dinet J. , Marquet P. , Nissen E.
Published: December 2003

Abstract The purpose of this exploratory study was to investigate the influence of two individual characteristics (Web experience and academic focus) of adolescents on the Web perception, using off‐line questionnaires (a Lickert response scale) constituted on the basis of a series of interviews. Questions concerned: perceptions about the nature of information found in the Web; ‘strategies’ of access to the interesting Internet sites and the reliability of different information resources (libraries, television, Web, etc.). Results lead to the assumption that adolescents with high Web experience became more critical, less confident and less enthusiastic than adolescents with low Web experience and that, in some dimensions, perceptions of literature students are different to those of science students. Even if some interesting results were obtained, further research is needed to explore users' perceptions related to individuals' characteristics and to determine the generalisability of the influences identified in this exploratory study.
The Internet for educating individuals with social impairments
Authors: Bishop J.
Published: December 2003

Abstract Social impairments materialise in a number of forms, from developmental disabilities such as autistic spectrum disorder, to psychiatric conditions such as social phobia. The individuals diagnosed with these problems find it difficult to deal with social situations through either the inability to perform in these situations or the fear of not being able to do so. The study investigated the social and practical implications of using Mobile Internet technology to deliver information relating to a social situation in real‐time to participants with Autistic Spectrum Disorders (n = 10) and General Social Phobia (n = 3) diagnosed using DSM‐IV. The participants used the agent on their mobile phone to convert phrases they found offensive or confusing into more concise and understandable definitions. Analysing their attitudes revealed that the technology enables socially impaired individuals to learn the meaning of emotions and understand more about how they communicate with their peers. However, the study concludes that governmental organisations, education providers and society as a whole need to adopt a cohesive approach to communication to ensure socially impaired individuals are fully included in society
Choosing the Best Volatility Models: The Model Confidence Set Approach*
Authors: Hansen Peter Reinhard , Lunde Asger , Nason James M.
Published: December 2003

This paper applies the model confidence set (MCS) procedure of Hansen, Lunde and Nason (2003) to a set of volatility models. An MCS is analogous to the confidence interval of a parameter in the sense that it contains the best forecasting model with a certain probability. The key to the MCS is that it acknowledges the limitations of the information in the data. The empirical exercise is based on 55 volatility models and the MCS includes about a third of these when evaluated by mean square error, whereas the MCS contains only a VGARCH model when mean absolute deviation criterion is used. We conduct a simulation study which shows that the MCS captures the superior models across a range of significance levels. When we benchmark the MCS relative to a Bonferroni bound, the latter delivers inferior performance.
Searching for the Causal Structure of a Vector Autoregression*
Authors: Demiralp Selva , Hoover Kevin D.
Published: December 2003

We provide an accessible introduction to graph‐theoretic methods for causal analysis. Building on the work of Swanson and Granger (Journal of the American Statistical Association, Vol. 92, pp. 357–367, 1997), and generalizing to a larger class of models, we show how to apply graph‐theoretic methods to selecting the causal order for a structural vector autoregression (SVAR). We evaluate the PC (causal search) algorithm in a Monte Carlo study. The PC algorithm uses tests of conditional independence to select among the possible causal orders – or at least to reduce the admissible causal orders to a narrow equivalence class. Our findings suggest that graph‐theoretic methods may prove to be a useful tool in the analysis of SVARs.
An Introduction to Best Empirical Models when the Parameter Space is Infinite Dimensional*
Authors: Ploberger Werner , Phillips Peter C. B.
Published: December 2003

Ploberger and Phillips (Econometrica, Vol. 71, pp. 627–673, 2003) proved a result that provides a bound on how close a fitted empirical model can get to the true model when the model is represented by a parameterized probability measure on a finite dimensional parameter space. The present note extends that result to cases where the parameter space is infinite dimensional. The results have implications for model choice in infinite dimensional problems and highlight some of the difficulties, including technical difficulties, presented by models of infinite dimension. Some implications for forecasting are considered and some applications are given, including the empirically relevant case of vector autoregression (VAR) models of infinite order.
Selecting a Nonlinear Time Series Model using Weighted Tests of Equal Forecast Accuracy*
Authors: van Dijk Dick , Franses Philip Hans
Published: December 2003

Nonlinear time series models have become fashionable tools to describe and forecast a variety of economic time series. A closer look at reported empirical studies, however, reveals that these models apparently fit well in‐sample, but rarely show a substantial improvement in out‐of‐sample forecasts, at least over linear models. One of the many possible reasons for this finding is the use of inappropriate model selection criteria and forecast evaluation criteria. In this paper we therefore propose a novel criterion, which we believe does more justice to the very nature of nonlinear models. Simulations show that this criterion outperforms those criteria currently in use, in the sense that the true nonlinear model is more often found to perform better in out‐of‐sample forecasting than a benchmark linear model. An empirical illustration for US GDP emphasizes its relevance.
Consistent Model Selection by an AutomaticGetsApproach*
Authors: Campos Julia , Hendry David F. , Krolzig Hans‐Martin
Published: December 2003

We establish the consistency of the selection procedures embodied inPcGets, and compare their performance with other model selection criteria in linear regressions. The significance levels embedded in thePcGetsLiberal and Conservative algorithms coincide in very large samples with those implicit in the Hannan–Quinn (HQ) and Schwarz information criteria (SIC), respectively. Thus, bothPcGetsrules are consistent under the same conditions as HQ and SIC. However,PcGetshas a rather different finite‐sample behaviour. Pre‐selecting to remove many of the candidate variables is confirmed as enhancing the performance of SIC.
Bayesian Model Selection with an Uninformative Prior*
Authors: Strachan Rodney W. , van Dijk Herman K.
Published: December 2003

Bayesian model selection with posterior probabilities and no subjective prior information is generally not possible because of the Bayes factors being ill‐defined. Using careful consideration of the parameter of interest in cointegration analysis and a re‐specification of the triangular model of Phillips (Econometrica, Vol. 59, pp. 283–306, 1991), this paper presents an approach that allows for Bayesian comparison of models of cointegration with ‘ignorance’ priors. Using the concept of Stiefel and Grassman manifolds, diffuse priors are specified on the dimension and direction of the cointegrating space. The approach is illustrated using a simple term structure of the interest rates model.
A Flexible Tool for Model Building: the Relevant Transformation of the Inputs Network Approach (RETINA)*
Authors: Perez‐Amaral Teodosio , Gallo Giampiero M. , White Halbert
Published: December 2003

A new method, called Relevant Transformation of the Inputs Network Approach is proposed as a tool for model building. It is designed around flexibility (with nonlinear transformations of the predictors of interest), selective search within the range of possible models, out‐of‐sample forecasting ability and computational simplicity. In tests on simulated data, it shows both a high rate of successful retrieval of the data generating process, which increases with the sample size and a good performance relative to other alternative procedures. A telephone service demand model is built to show how the procedure applies on real data.