bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost-effectiveness of interpersonal psychotherapy for elderly primary care patients with major depression
Authors: Bosmans Judith E. , van Schaik Digna J. F. , Heymans Martijn W. , van Marwijk Harm W. J. , van Hout Hein P. J. , de Bruijne Martine C.
Published: October 2007

Objectives:Major depression is common in elderly patients. Interpersonal psychotherapy (IPT) is a potentially effective treatment for depressed elderly patients. The objective of this study was to evaluate the cost-effectiveness of IPT delivered by mental health workers in primary care practices, for depressed patients 55 years of age and older identified by screening, in comparison with care as usual (CAU).

Methods:We conducted a full economic evaluation alongside a randomized controlled trial comparing IPT with CAU. Outcome measures were depressive symptoms, presence of major depression, and quality of life. Resource use was measured from a societal perspective over a 12-month period by cost diaries. Multiple imputation and bootstrapping were used to analyze the data.

Results:At 6 and 12 months, the differences in clinical outcomes between IPT and CAU were small and nonsignificant. Total costs at 12 months were €5,753 in the IPT group and €4,984 in the CAU group (mean difference, €769; 95 percent confidence interval, −2,459 – 3,433). Cost-effectiveness planes indicated that there was much uncertainty around the cost-effectiveness ratios.

Conclusions:Based on these results, provision of IPT in primary care to elderly depressed patients was not cost-effective in comparison to CAU. Future research should focus on improvement of patient selection and treatments that have more robust effects in the acute and maintenance phase of treatment.
Future relevance of genetic testing: A systematic horizon scanning analysis
Authors: Storz Philipp , Kolpatzik Kai , Perleth Matthias , Klein Silvia , Häussler Bertram
Published: October 2007

Objectives: The aim of this study was to identify research and development on genetic testing to find out if research addresses important disease areas, how far it is from potential clinical use, and what consequences might arise for the prioritization of health technology assessment (HTA) activities. Also a horizon scanning methodology developed in Germany is demonstrated.

Methods: A systematic search on genetic testing was conducted in an innovation database (ZIM database). Based on a daily monitoring of literature and Internet sources, reports from 2003 up to 2005 were classified related to the type of innovation, the addressed disease categories, and the developmental phase of the technology. More detailed analyses for the most frequently addressed groups of diseases were conducted.

Results: From 239 relevant reports, 41 percent referred to neoplasms; 10 percent to diseases of the cardiovascular system; 9 percent to diseases of the nervous system; 7 percent to mental and behavioral disorders; and 5 percent to endocrine, nutritional, and metabolic diseases. A total of 69 percent of research is situated in basic preclinical research, 22 percent in clinical/experimental research, and 6 percent are genetic tests being used. Diagnostic applications were most frequently reported (28 percent), followed by therapeutic prediction (22 percent), preventive prediction (18 percent), pharmacogenetics (16 percent), and screening (16 percent).

Conclusions: Widespread diseases are frequently addressed in research. HTA on genetic testing might focus on innovations addressing neoplastic diseases (in particular breast, colon, and prostate cancers) and pharmacogenetic applications for therapeutic prediction. The horizon scanning approach seems useful in the early steps of HTA processes to identify emerging new technologies that might have significant impact on future health care.
Consensus statement on healthy mothers–healthy babies: How to prevent low birth weight
Authors: Chair Conference Panel , Chair Conference Expert
Published: October 2007

All of the panelists who participated in this conference and contributed to the writing of this statement were identified as having no financial or scientific conflict of interest, and all signed forms attesting to this fact. Unlike the expert speakers who present scientific data at the conference, the individuals invited to participate on the consensus panel are reviewed prior to selection to ensure they are not proponents of an advocacy position with regard to the topic.
Coverage with evidence development: A very good beginning, but much to be done. Commentary to Hutton et al.
Authors: Tunis Sean R. , Chalkidou Kalipso
Published: October 2007

The study by Hutton, Trueman, and Henshall provides a thoughtful and helpful set of observations about the potential benefits of linking reimbursement to requirements for further clinical research (coverage with evidence development—CED), as well as the likely challenges and obstacles to implementation. In this commentary, we will expand upon several of the key points made in their study and offer some additional suggestions for moving this policy discussion forward
Priority setting for health technology assessments: A systematic review of current practical approaches
Authors: Noorani Hussein Z. , Husereau Donald R. , Boudreau Rhonda , Skidmore Becky
Published: October 2007

The email address provided for Hussein Z. Noorani in the “Contact Information” section of the above article is incorrect. The correct email address is husseinn@cadth.ca.
Health technology assessment agencies: An international overview of organizational aspects
Authors: Martelli Francesco , Torre Giuseppe La , Ghionno Elena Di , Staniscia Tommaso , Neroni Massimo , Cicchetti Americo , Bremen Konrade Von , Ricciardi Walter ,   NI-HTA Collaborative Group
Published: October 2007

Objectives:The aim of the study is to make an international comparison of Health Technology Assessment (HTA) Agencies, to show their similarities and differences.

Methods:An e-mail questionnaire was sent to thirty HTA agencies internationally. Questions related to the structure of the agency, the relationship with health-related institutions, the prescriptiveness of the decisions taken, the main core and the modalities to spread the assessment, and the type of funding.

Results:Twenty-four HTA Agencies answered the questionnaire: 25 percent in America, 4.2 percent in Australia, and 70.8 percent in Europe. Fifty-four percent of HTA Agencies are governmental institutions (83.3 percent have central government funding), while 62.5 percent have relationships with health-related governmental institutions. Of the agencies, 87 percent reported that their decisions are not prescriptive, while for 20.8 percent and 8.3 percent of them stated that this was the case totally or partially, respectively, especially for the governmental and American Agencies. Seventeen agencies (70.8 percent) declared their work on multiannual programs (77 percent of the governmental HTA Agencies and 100 percent of the American ones). The assessments mainly addressed diagnostic procedures (85.7 percent) and pharmaceuticals (25 percent). The most common way to disseminate results is by means of paper report (91.7 percent), followed by the Internet (16.7 percent), and seminars to expert audiences (12.5 percent).

Conclusions:The comparative analysis of HTA Agencies showed that governmental and American Agencies have a profound impact on the prescriptiveness of their assessment, and this could be linked to the fact that these types of Agencies work on multiannual programs. European and American HTA Agencies have many similarities in terms of type of assessment, funding, and dissemination of results.
Coverage with Evidence Development: An examination of conceptual and policy issues
Authors: Hutton John , Trueman Paul , Henshall Christopher
Published: October 2007

The application of conditionality to coverage decisions for healthcare technologies is increasing. Coverage with Evidence Development (CED) represents a specific approach to coverage for promising technologies for which the evidence remains uncertain. CED demands that additional evidence is generated to address the sources of uncertainty and secure ongoing coverage. This study explores the conceptual and policy issues relating to CED and discusses issues involved in operationalizing CED in practice, including presenting criteria for which technologies may be most suitable for CED. This study is intended to further the debate on the use of CED as well as highlight areas that warrant further research.
Screening for fetal abnormalities: From a health technology assessment report to a national statute
Authors: Autti-Rämö Ilona , Mäkelä Marjukka
Published: October 2007

Objectives: Previously in Finland, each municipality selected which methods to use in screening for fetal abnormalities. This resulted in practice variation and inequity. The national health technology assessment (HTA) office Finohta compared the methods and time frames available when screening for chromosomal and structural abnormalities. The assessment identified a need to discuss several value-laden questions before policy decisions could be taken.

Methods: The National Screening Committee (NSC) at the Ministry of Health and Social Affairs (MOH) formulated a statement based on the HTA report to inform policy makers. This article describes the steps in the policy process.

Results: The national screening committee organized an open forum to discuss the ethically relevant aspects of fetal screening, and a lengthy public discussion highlighted the viewpoints of various stakeholders. Based on the assessment, public discussion, and several committee meetings that heard further experts, the NSC formulated a conclusion based on equity of access. This also offered options for families unwilling to terminate a pregnancy due to fetal abnormality. The MOH sent the conclusion to a comment round, and the proposal was accepted with minor adjustments. The Ministry decided to unify the regulation of all public screening programs by one statute. The policy process lasted three years, and the methods to screen for fetal abnormalities will be unified after a further 3 years.

Conclusions: The assessment of screening programs for fetal abnormalities reached beyond its original mandate. The process of examining values behind screening resulted in a program that respects the differing objectives and ethical values of pregnant families, and to national legislation on screening programs.
Impact of new medical technologies on health expenditures in Israel 2000–07
Authors: Rabinovich Mordechai , Wood Francis , Shemer Joshua
Published: October 2007

Objectives: The aim of this study was to estimate the impact of new medical technologies on public healthcare expenditures in Israel over the period 2000–07.

Methods: For each year, government estimates for the costs of new technologies recommended as high-priority for public funding were summarized. The ratio of projected costs of these technologies to total public healthcare expenditures was calculated and compared with actual governmental budget allocations for new technologies.

Results: Funding all new high-priority medical technologies would have increased healthcare expenditures by 2.1 percent per year. Government allocations for new technologies raised expenditures by 1.0 percent per year.

Conclusions: New medical technologies significantly increase healthcare expenditures in Israel. Budgetary constraints have reduced their actual impact by 52 percent. This study indicates the need for an annual addition of 2 percent to public healthcare budget for funding new high-priority technologies.
Introduction of emerging medical devices on the market: A new procedure in Belgium
Authors: Vinck Imgard , Neyt Mattias , Thiry Nancy , Louagie Marleen , Ramaekers Dirk
Published: October 2007

When new medical technologies enter the market, there is often uncertainty about the added value for the patient and for society, hampering well-considered decision making about reimbursement. Current Belgian legislation already offered opportunities for the managed uptake of possibly innovative emerging implants. However, it has also some shortcomings such as the lack of a clear research design, rendering the scientific evaluation of clinical effectiveness, cost-effectiveness, and patient or organizational issues more difficult. Against this background, a new procedure was elaborated by the Belgian health insurance institute and the Belgian Health Care Knowledge Centre.
A revised typology of opaque generalisations
Authors: Baković Eric
Published: October 2007

This paper is about opaque interactions between phonological processes in the two senses defined by Kiparsky (1971, 1973) and discussed in much recent work on the topic, most notably McCarthy (1999) :underapplicationopacity, whereby a process appears to have failed to apply in expected contexts on the surface, andoverapplicationopacity, whereby a process appears to have applied in unexpected contexts on the surface. Specifically, I demonstrate that there are three distinct types of overapplication opacity in addition to the only case discussed and properly categorised as such in the literature, counterbleeding. The analysis of each type of opacity in terms of rule-based serialism and in terms of Optimality Theory is discussed, emphasising the strengths and weaknesses of the two frameworks in each case.
The relationship between the perception of non-native phonotactics and loanword adaptation
Authors: Davidson Lisa
Published: October 2007

This study examines how phonetic details produced by non-bilingual borrowers (‘disseminators’) are categorised when new words are transmitted to the monolinguals of the borrowing language community (‘recipients’). The stimuli are based on research showing that the schwa inserted by English speakers into non-native clusters (e.g. /zgɑmo/→[zəgɑmo]) differs acoustically from lexical schwa (e.g. [zəgɑmo]). In Experiment 1, listeners transcribed Cluster (CC), Lexical (CəC) and Transitional (CəC) stimuli produced by an English speaker. Transcriptions of CəC stimuli were split between CC and CVC, and participants wrote CəC with a vowel less often than they did CəC. Experiment 2 demonstrated that listeners had difficulty discriminating between CəC and both CC and CəC. These findings suggest that CəC is acoustically intermediate between clusters and schwas; thus recipients may assign CəC token to either of the phonotactic categories CC or CəC. The ramifications of these findings for loanwords and the acquisition of phonological contrast are discussed.
Syllabification patterns in Arabic dialects: long segments and mora sharing
Authors: Watson Janet C. E.
Published: October 2007

In Classical Arabic and many modern Arabic dialects, syllables ending in VVC or in the left leg of a geminate have a special status. An examination of Kiparsky's (2003) semisyllable account of syllabification types and related phenomena in Arabic against a wider set of data shows that while this account explains much syllable-related variation, certain phenomena cannot be captured, and several dialects appear to exhibit conflicting syllable-related phenomena. Phenomena not readily covered by the semisyllable account commonly involve long segments – long vowels or geminate consonants. In this paper, I propose for relevant dialects a mora-sharing solution that recognises the special status of syllables incorporating long segments. Such a mora-sharing solution is not new, but has been proposed for the analysis of syllables containing long segments in a number of languages, including Arabic (Broselow 1992, Broselowet al.1995), Malayalam, Hindi (Broselowet al.1997) and Bantu languages (Maddieson 1993, Hubbard 1995).
The variable development of English word-final stops by Brazilian Portuguese speakers: A stochastic optimality theoretic account
Authors: Cardoso Walcir
Published: October 2007

One of the core problems in second language acquisition theory is how to describe and explain the highly variable (yet rule-governed) speech of second language learners. Is such variation simply random and most likely due to the first language's interference, or is it governed (at least in part) by general rules that reflect language universals? Within a multidisciplinary approach to the analysis of variability in second language acquisition, this article addresses these questions in the context of a cross-sectional study involving the acquisition of word-final stops by Brazilian Portuguese speakers learning English in a classroom environment. The study follows a sociolinguistic approach for data collection and the analysis is couched within a stochastic version of Optimality Theory.
The Impact of Recording on Listening
Authors: CLARKE ERIC F.
Published: October 2007

The development of recording is arguably the most significant change to have affected music in the twentieth century. Never before have people had access to so much music and in so many different ways and with so many different patterns of use. This paper examines some of the effects of recording on listening, starting with a brief outline of an ecological theory of listening and focusing on three specific characteristics of recordings: the interpenetration of music and the wider environment; recordings as medium and as object; and the relationship between social and solitary listening practices. Recording has attracted both utopian and dystopian commentaries on its effects on musical culture, and the paper concludes by considering both the opportunities and the drawbacks of recordings as a means of access to music.
Zwangsstörungen
Authors: Freyberger Harald J. , Hohagen Fritz
Published: October 2007

Zusammenfassung: In der wissenschaftlichen Literatur werden Zwangsstörungen heute als eine heterogene Gruppe von Erkrankungen aufgefasst. Die derzeit vielversprechendsten Versuche der Subtypisierung beziehen sich auf klinische Merkmale im weitesten Sinne und Symptomkonfigurationen. Werden die vorliegenden epidemiologischen, neurobiologischen und Therapiestudien zusammengefasst, so können die Zwangsstörungen im Sinne eines Spektrums sich zum Teil überlappender Syndrome verstanden werden.
Epidemiologie, Familiarität und Genetik der Zwangsstörung
Authors: Grabe Hans Jörgen , Janowitz Deborah , Freyberger Harald J.
Published: October 2007

Zusammenfassung: Zahlreiche epidemiologische Studien der letzten Jahre haben weltweit eine Lebenszeitprävalenz der Zwangsstörung von 1-3 % ermittelt. Es findet sich in der Allgemeinbevölkerung eine leicht erhöhte Erkrankungsrate bei Frauen. Aktuelle kontrollierte Familienstudien zeigen eindeutig eine familiäre Transmission der Zwangsstörung auf. Diese Befunde deuten, zusammen mit einigen allerdings methodisch schwächeren Zwillingsstudien, auf eine genetische Erkrankungsdisposition hin. Zahlreiche genetische Assoziationsstudien sind bislang bei der Zwangsstörung mit zumeist inkonsistenten Befunden durchgeführt worden. Gerade Kandidatengene des serotonergen und dopaminergen Systems zeigten keine konsistenten Assoziationen. In methodisch optimierten aktuellen Studien zeigten sich viel versprechende Assoziationen zu Polymorphismen des Glutamat-Transportergens (SLC1A1) und des OLIG2-Gens (Oligodendrocyte lineage transcription factor 2). Methodische Implikationen für zukünftige genetische Untersuchungen bei der als ätiopathogenetisch heterogen imponierenden Zwangsstörung werden diskutiert.
Themenschwerpunkt
Authors: Kordon Andreas , Zurowski Bartosz , Hohagen Fritz
Published: October 2007

Zusammenfassung: Die Zwangsstörung ist eine heterogene Erkrankung. Die klinische Heterogenität und unterschiedliche Ansprechbarkeit auf Therapie mit Unterschieden in neurobiologisch zu definierenden Subtypen in Verbindung zu bringen, stellt eine der wichtigsten Entwicklungen bei der Erforschung der Zwangserkrankung in den letzten zwei Jahrzehnten dar. Es wird ein Überblick über pathophysiologische Modelle gegeben, die versuchen, die unterschiedlichen Subtypen widerzuspiegeln. Schließlich stellen wir ein heuristisches Model der Zwangsstörung vor, welches auf phänomenologischen Charakteristika, Befunden der Bildgebung und neuroanatomischen Erwägungen beruht.
Die Wirksamkeit verhaltenstherapeutischer Behandlungsverfahren bei Zwangsstörungen
Authors: Kathmann Norbert
Published: October 2007

Zusammenfassung: Die kognitiv-verhaltenstherapeutische Behandlung (KVT) der Zwangsstörung kann aufgrund neuerer randomisierter kontrollierter Studien als hoch wirksam angesehen werden. Effektstärken liegen etwa im Bereich von 1.0 bis 1.5. Auch bei Kindern und Jugendlichen ist eine ähnliche Wirksamkeit vorhanden. Es treten nahezu keine Placeboeffekte auf. Die Hälfte der behandelten Patienten kann mit klinisch signifikanter Besserung rechnen. Es verbleiben viele Patienten, die nicht profitieren und ein verbessertes Therapieangebot brauchen. Die Kombination von Psychopharmaka und KVT erhöht die Therapiewirksamkeit bei schwer depressiven Patienten mit Zwangsstörung. Verhaltenstherapie senkt die Rückfallgefahr, die ansonsten nach Absetzen der antiobsessiven Medikation gegeben ist. Ansonsten wurden bisher keine additiven Effekte belegt. Ökonomische und niederschwellige Varianten der Therapie, wie Gruppen, internet-, telefon-, oder videobasierte Interventionen werden erst in jüngster Zeit untersucht. Dabei zeigten sich bisher positive Ergebnisse. Geringer Therapieerfolg wird prädiziert durch mangelnde Compliance, hohe Krankheitsschwere, schwere komorbide Depression, komorbide schizotype Persönlichkeitsstörung, sowie ausgeprägte Sammelsymptome. Neben der Verbesserung der Therapietechniken muss eine höhere Verfügbarkeit adäquater Therapieangebote das Ziel weiterer Bemühungen sein.
Validierung des SPS-J an einer kinder- und jugendpsychiatrischen Inanspruchnahmepopulation
Authors: Goldbeck Lutz , Besier Tanja , Petermann Franz , Karpinski Norbert , Hampel Petra
Published: October 2007

Zusammenfassung: Das Screening psychischer Störungen im Jugendalter (SPS-J) dient der orientierenden Diagnostik psychischer Störungen auf der Verhaltens- und emotionalen Ebene bei Jugendlichen. Die psychometrischen Eigenschaften des SPS-J wurden an 286 psychiatrisch auffälligen Patienten (Alter: M = 14.0 Jahre, SD = 2.0 Jahre; 44 % weiblich) untersucht. Die interne Konsistenz der Gesamtskala (α = .89) und der vier Subskalen war zufrieden stellend. Die Faktorenstruktur der angloamerikanischen Originalversion konnte weitgehend repliziert werden. Die Validierung am Elternurteil in der Child Behavior Checklist (r = .34) zeigte die erwartete moderate Übereinstimmung. Verglichen mit der deutschen Normstichprobe wies die klinische Stichprobe nur geringfügig erhöhte Mittelwerte in den Skalen des SPS-J auf, so dass die Sensitivität des Fragebogens mit 0.31 unzureichend war. Die varianzanalytischen Ergebnisse mit drei Diagnosegruppen (internalisierende, externalisierende und kombinierte Störungen) stützen die diskriminative Validität des SPS-J. Der SPS-J erweist sich als ein Instrument mit zufrieden stellenden Skalenkonsistenzen und mit hinreichender faktorieller, konvergenter und diskriminativer Validität.
Trends und Anwendungsgebiete der Klinischen Kinderpsychologie
Authors: Petermann Franz , Hamid Leila
Published: October 2007

Zusammenfassung: Die noch junge Disziplin der Klinischen Kinderpsychologie zeigt in verschiedenen Anwendungsgebieten erhebliche Fortschritte auf. Im Detail werden ausgeführt: Entwicklungs- und Intelligenzdiagnostik, Betreuung chronisch kranker Kinder und Jugendlicher, Essstörungen und Adipositas, ADHS, Lernstörungen, familienorientierte Diagnostik und Therapie sowie Qualitätssicherung in der psychotherapeutischen Versorgung. Einige Konzepte (z. B. ADHS) besitzen eine immer größere Bedeutung in der Psychiatrie und Klinischen Psychologie des Erwachsenenalters. Die entwicklungsorientierte Denkweise kann als zukunftsweisend für die Psychotherapie und Psychiatrie angesehen werden.
A parametric ray tracing study of superluminous auroral kilometric radiation wave modes
Authors: Xiao Fuliang , Chen Lunjin , Zheng Huinan , Wang Shui
Published: October 2007

We present a ray tracing study on the propagation characteristic of the superluminous wave modes (R–X, L–O) that are generated as auroral kilometric radiation (AKR) in the Earth's magnetosphere by using a cavity plasma density model and a global core plasma density model. Numerical calculations have been performed for the two modes which originate at three altitudes, r = 1.0, 1.5, and 2 RE in the source cavity along a 70° night field line. We show that the propagation characteristic of the R–X and the L–O modes is found to be essentially controlled by the source cavity position and the plasmapause position, in particular because the reflection occurs at the sharp density edges of the two positions. During high geomagnetic activity (e.g., Kp = 6, where Kp is the geomagnetic activity index), the plasmapause position moves inward, closer to the Earth, the R–X and L–O modes can propagate downward and even through the equatorial plane in the radiation belts under appropriate conditions, since no reflection occurs. However, during low geomagnetic activity (e.g., Kp = 2), both modes basically propagate at higher latitudes because of the reflection in the vicinity of the plasmapause and the source cavity. Furthermore, as the wave frequency or the originated altitude is higher, the reflection becomes weaker, and correspondingly the AKR observational latitude is lower. The wave damping along the ray path is found to be substantially small, primarily because high resonant energies will occur, while specifically Landau damping will not for the electrons in gyroresonance with superluminous waves. The results above provide a new insight into the propagation characteristic of R–X and L–O modes and predict that the two modes may be physically present in the radiation belts of the Earth particularly during strong geomagnetic activities. This needs to be further supplemented by observational analysis.
A probabilistic damage model of stress‐induced permeability anisotropy during cataclastic flow
Authors: Zhu Wenlu , Montési Laurent G. J. , Wong Teng‐fong
Published: October 2007

A fundamental understanding of the effect of stress on permeability evolution is important for many fault mechanics and reservoir engineering problems. Recent laboratory measurements demonstrate that in the cataclastic flow regime, the stress‐induced anisotropic reduction of permeability in porous rocks can be separated into 3 different stages. In the elastic regime (stage I), permeability and porosity reduction are solely controlled by the effective mean stress, with negligible permeability anisotropy. Stage II starts at the onset of shear‐enhanced compaction, when a critical yield stress is attained. In stage II, the deviatoric stress exerts primary control over permeability and porosity evolution. The increase in deviatoric stress results in drastic permeability and porosity reduction and considerable permeability anisotropy. The transition from stage II to stage III takes place progressively during the development of pervasive cataclastic flow. In stage III, permeability and porosity reduction becomes gradual again, and permeability anisotropy diminishes. Microstructural observations on deformed samples using laser confocal microscopy reveal that stress‐induced microcracking and pore collapse are the primary forms of damage during cataclastic flow. A probabilistic damage model is formulated to characterize the effects of stress on permeability and its anisotropy. In our model, the effects of both effective mean stress and differential stress on permeability evolution are calculated. By introducing stress sensitivity coefficients, we propose a first‐order description of the dependence of permeability evolution on different loading paths. Built upon the micromechanisms of deformation in porous rocks, this unified model provides new insight into the coupling of stress and permeability.
Seasonal heat budgets of the Red and Black seas
Authors: Matsoukas C. , Banks A. C. , Pavlakis K. G. , Hatzianastassiou N. , Stackhouse P. W. , Vardavas I.
Published: October 2007

In this study we calculate the monthly heat budget of the Red and Black Seas and its components: the net solar and net terrestrial fluxes, the sensible and latent heat fluxes, and the monthly heat content change. A radiation transfer model is employed for the estimation of the net solar and terrestrial energy fluxes, instead of commonly used parameterizations. The agreement with radiation fluxes measured at surface stations is within 10 W m−2. The Red Sea net solar flux estimate is lower than past studies, while the Black Sea heat budget components are comparable to some past results. The monthly heat content of both seas is estimated from water temperature and salinity profiles and is found to dominate the seasonal energy exchange between the water and the atmosphere, as for the Mediterranean Sea. The latent heat flux is calculated using two methodologies: the bulk aerodynamic and the energy balance method. Our annual results for the Red and Black seas show solar heating of 238 and 139 W m−2, respectively. The evaporation rates are 2120 and 960 mm yr−1, respectively. The annual aerosol direct forcing on the net solar flux is −10 W m−2 and −3 W m−2.
Telescoping, multimodel approaches to evaluate extreme convective weather under future climates
Authors: Trapp Robert J. , Halvorson Brooke A. , Diffenbaugh Noah S.
Published: October 2007

Understanding of the possible response of severe convective precipitating storms to elevated greenhouse gas concentrations remains elusive. To address this problem, telescoping, multimodel approaches are proposed, which allow representation of a broad range of processes that could regulate convective storm behavior. In the global‐cloud approach (G‐C), the NCEP‐NCAR Reanalysis Project (NNRP) global data set provides initial and boundary conditions for short‐term integrations of a mesoscale model and nested convective‐cloud‐permitting domain. In the global‐regional‐cloud approach (G‐R‐C), the NNRP data set provides initial and boundary conditions for long‐term integrations of a regional climate model, which in turn forces short‐term integrations of a mesoscale model and nested convective‐cloud‐permitting domain. Upon applying these approaches to historical extreme convective storm events, it was found that the global‐scale data could be dynamically downscaled to produce realistic convective‐scale solutions. In particular, tornado proxies computed from the model‐simulated winds were shown to compare well in relative numbers to those of tornado observations on many of the days considered. This supports the telescoping modeling concept as a viable means to address effects of elevated greenhouse gas concentrations on convective‐scale phenomena. In an evaluation of the two approaches, it was also found that simulations of the historical events by the G‐C were superior to those by the G‐R‐C. Sensitivity of the convective‐scale processes to details in the downscaled synoptic‐scale flow, and to the placement of the mesoscale model domain within the regional climate model, reduced the effectiveness of the G‐R‐C.
On Radlow's quarter‐plane diffraction solution
Authors: Albani Matteo
Published: October 2007

In this paper, we demonstrate that Radlow's solution to diffraction by the soft quarter plane is incorrect. We derive an explicit expression for the Wiener‐Hopf factorizing function and verify that a nonvanishing term, which was not accounted for by Radlow, arises from a correct evaluation of the field on the quarter plane. Consequently, the field function proposed by Radlow does not satisfy the boundary conditions, and therefore it is not the correct solution to diffraction by a quarter plane.
Exact radiation of a dipole in the presence of a circular aperture in a ground plane backed by a spheroidal cavity and covered with an isorefractive diaphragm
Authors: Valentino M. , Erricolo D.
Published: October 2007

An oblate semispheroidal cavity with metallic walls flush‐mounted under a metallic ground plane is coupled to the half‐space above the ground plane through an aperture that corresponds to the interfocal disk of the oblate spheroidal system. A diaphragm is located across the aperture. The diaphragm material, the material filling the cavity, and the half‐space are isorefractive to each other. A new exact solution is obtained for the radiation of an electric or a magnetic dipole located on the symmetry axis of the structure and axially oriented. The exact solution is expressed in terms of series containing oblate spheroidal functions. These series are evaluated to provide a benchmark solution for a primary source located either inside the cavity below the diaphragm or outside the cavity in the unbounded medium.
Equilibrium entrainment of fine sediment over a coarse immobile bed
Authors: Grams Paul E. , Wilcock Peter R.
Published: October 2007

The transported load in most fluvial systems, including gravel‐bedded rivers, includes fine‐grained sediment. Models for suspended sediment transport have focused on sand‐covered beds, rendering incomplete the theoretical and empirical framework for predicting fine sediment transport and routing. We conducted laboratory experiments involving sand transport over large immobile grains. The experiments were scaled such that immobile particles were much larger than the mobile sediment, but less than 10% of flow depth, and that bed shear stresses, scaled by the size of the mobile sediment, were indicative of transport in suspension. The experiments were conducted in equilibrium transport and included measurements of near‐bed sediment concentration and interstitial sand storage for a range of flow and transport rates. Partial filling of grain interstices occurred over a narrow range of flow and transport rates, indicating a sharp threshold between no interstitial sand storage and a sand‐covered bed. Less sand coverage on the bed resulted in higher near‐bed sand concentrations per unit area of sand than runs with greater sand coverage. As sand bed elevation decreased relative to the coarse grains, turbulent wakes shed by the large grains appeared to enhance grain entrainment more than the corresponding decrease in bed area covered by sand resulted in decreased entrainment. Elevated concentrations were maintained until the bed was depleted of fine sediment. These results are formalized in a proposed sand elevation correction function that scales the entrainment rate for a bed partially covered by sand to the entrainment rate that would be predicted for a sand‐covered bed.
Correspondence of the Gardner and van Genuchten–Mualem relative permeability function parameters
Authors: Ghezzehei Teamrat A. , Kneafsey Timothy J. , Su Grace W.
Published: October 2007

The Gardner and van Genuchten–Mualem models of relative permeability are widely used in analytical and numerical solutions to flow problems, respectively. Comparison of analytical and numerical solutions therefore requires defining some correspondence between the Gardner and van Genuchten–Mualem models. In this paper, we introduce generalized conversion formulae that reconcile these two models in the midrange of saturation. In general, we find that the Gardner parameter αG is related to the van Genuchten parameters αvG and n as αG ≈ 1.3αvGn. The performance of the proposed conversion formulae is poor when n is much smaller than 2.
Possible impacts of anthropogenic aerosols on water resources of the Jordan River and the Sea of Galilee
Authors: Givati Amir , Rosenfeld Daniel
Published: October 2007

Insights are provided to the hitherto unexplained decreasing trends in the available water for consumption from the Sea of Galilee and in the outflow of the main springs of the Jordan River with respect to the nearby rainfall. The loss of available water of about 110 million m3 yr−1 (about 6.5% of the national water consumption in Israel) is shown to be caused by a decreasing trend in the factor of precipitation enhancement by uplifting on topographic barriers. Previous studies, reviewed here, show that the most probable cause of this decreasing trend is an increasing trend in the concentrations of submicron air pollution particles during the last half century. These particles slow down the conversion of cloud drops into raindrops and snow flakes, thus decreasing precipitation from short‐lived clouds such as form in moist air that crosses topographic barriers. This decreasing trend was partially mitigated by cloud seeding for rain enhancement, but apparently, the air pollution dominated and caused a net loss of orographic precipitation. A large portion of the water resources in this semiarid part of the world results from orographic precipitation. Therefore this is an issue with major economic and societal implications, not only to the study area but to many other densely populated parts of the world where the livelihood of the inhabitants depends on water resulting from orographic precipitation, which might be compromised by the air pollution produced by the very people who depend on that water.
Numerical simulations of single‐pass hydrothermal convection at mid‐ocean ridges: Effects of the extrusive layer and temperature‐dependent permeability
Authors: Lowell Robert P. , Gosnell Sawyer , Yang Yang
Published: October 2007

We develop numerical models of hydrothermal convection at oceanic spreading centers to understand the interplay between deeply circulating high‐temperature hydrothermal fluid and cooler seawater circulating in basalts of the upper crust. We assume the deep circulation follows an idealized single‐pass geometry and consider the effects of the thickness h and permeability of the extrusive layer kext both on the shallow circulation and on the temperature and heat output of the high‐temperature discharge. We also attempt to model the effect of mineral precipitation on mixing in the shallow crust by emplacing a low‐permeability vertical barrier in the extrusives to separate the high‐temperature discharge from the circulation in the extrusives. Finally, we investigate the effects of temperature‐dependent permeability on the mixing scenarios. The results show that maximum discharge temperature Tv is impacted more by the ratio kext/kd, where kd is the permeability of the deep discharge channel, than by h. Generally, high‐temperature discharge (Tv > 250°C) occurs provided kd > kext. In this case, the presence of a low‐permeability barrier further enhances Tv. Low‐temperature discharge (Tv < 150°C) can occur provided kext > 10kd. For systems such as the Galapagos Spreading Center, where vent temperatures are ∼20°C, kext/kd > 104, and the extrusive layer is likely to be thick. The results also suggest that sites of diffuse flow will occur either between high‐temperature vents along the ridge axis or off axis. The chemical composition of the fluid at these distal sites would be seawater, perhaps modified by low‐temperature water‐rock reactions. In contrast, the diffuse flow fluids near high‐temperature vents are mixture of seawater with high‐temperature hydrothermal fluid. Finally, the results show that the 150°C isotherm, which lies nearly horizontally at some distance from the discharge channel, may be within the extrusive layer, near the extrusive‐dike interface, or within the low‐permeability dike layer. This result supports the idea that the seismically defined layer 2A‐2B boundary within the oceanic crust may represent a mineral precipitation front rather than a lithologic boundary.
Mantle plumes: Dynamic models and seismic images
Authors: Boschi L. , Becker T. W. , Steinberger B.
Published: October 2007

Different theories on the origin of hot spots have been debated for a long time by many authors from different fields, and global‐scale seismic tomography is probably the most effective tool at our disposal to substantiate, modify, or abandon the mantle‐plume hypothesis. We attempt to identify coherent, approximately vertical slow/hot anomalies in recently published maps of P and S velocity heterogeneity throughout the mantle, combining the following independent quantitative approaches: (1) development and application of a “plume‐detection” algorithm, which allows us to identify a variety of vertically coherent features, with similar properties, in all considered tomographic models, and (2) quantification of the similarity between patterns of various tomographic versus dynamic plume‐conduit models. Experiment 2 is complicated by the inherent dependence of plume conduit tilt on mantle flow and by the dependence of the latter on the lateral structure of the Earth's mantle, which can only be extrapolated from seismic tomography itself: it is inherently difficult to disentangle the role of upwellings in “attracting” plumes versus plumes being defined as relatively slow, and thus located in regions of upwellings. Our results favor the idea that only a small subset of known hot spots have a lower‐mantle origin. Most of those that do can be associated geographically with a few well‐defined slow/hot regions of very large scale in the lowermost mantle. We find evidence for both secondary plumes originating from the mentioned slow/hot regions and deep plumes whose conduits remain narrow all the way to the lowermost mantle. To best agree with tomographic results, modeled plume conduits must take into account the effects of advection and the associated displacement of plume sources at the base of the mantle.
Channel network extraction from high resolution topography using wavelets
Authors: Lashermes Bruno , Foufoula‐Georgiou Efi , Dietrich William E.
Published: October 2007

The availability of high resolution topography from LIDAR offers new opportunities for objectively extracting the channels directly from a DEM using local topographic information, instead of inferring them indirectly based on global criteria, such as area or area‐slope threshold relationships. Here we introduce the use of wavelet filtering to delineate threshold curvatures for defining valleys and threshold slope‐direction‐change for defining probable channeled portions of the valleys. This approach exploits the topographic signatures uniquely found in high resolution topography, and reveals the fuzzy topographic transition in which local weakly convergent areas lie at the transition between hillslopes and valleys.
Shear wave splitting across the Ailao Shan‐Red River fault zone, SW China
Authors: Huang Zhouchuan , Wang Liangshu , Xu Mingjie , Liu Jianhua , Mi Ning , Liu Shaowen
Published: October 2007

A broad band seismic array was set up across the Ailao Shan‐Red River (ASRR) fault zone, SW China. The shear wave splitting parameters on SKS and SKKS phases are calculated using the method of Silver and Chan (1991) and indicate the polarization direction of 105 ± 6° and the delay time of 1.68 ± 0.44 s beneath the ASRR fault zone. Combined with previous studies, the average polarization direction is 110 ± 19° and the delay time is 1.58 ± 0.44 s to the SW side of the fault, while the values are 83 ± 30° and 1.29 ± 0.29 s to the NE side. This result implies that the upper mantle anisotropy to two sides of the ASRR fault zone are different. Compared with the SE polarization direction observed in the P‐S phase and the N‐to‐S surface movement in GPS data, our results suggest decoupling of the crust and upper mantle beneath the study region.
Particle‐in‐cell simulation study of the impact of ion cyclotron waves on auroral kilometric radiation
Authors: Bessho N. , Menietti J. D.
Published: October 2007

We will present results of 2 1/2‐dimensional particle‐in‐cell simulations where the impact of ion cyclotron waves on auroral kilometric radiation (AKR) has been studied. A horseshoe electron distribution function in a strong magnetic field is unstable to modes with frequencies slightly below the electron cyclotron frequency and can generate AKR. In the presence of an electron beam superimposed on the horseshoe distribution, the system is unstable to ion cyclotron waves with phase velocity parallel to the magnetic field equal to the electron beam velocity. Ion cyclotron waves are often observed near the source region of AKR and have been predicted to have an influence on AKR. We have found that the parallel electric field in the ion cyclotron wave modulates the energy density of the electrons at the ion cyclotron frequency. Forced oscillation of the parallel electric field with the ion cyclotron frequency has been added in the simulations to see the influence on AKR. The growth rate of AKR decreases significantly when the ion cyclotron wave has the parallel phase velocity in the same direction as the electron beam. We have found that the intensity of the AKR as well as the electron energy density is also modulated by the ion cyclotron wave. We will discuss how the modulation of the electron energy affects the growth of AKR and how this modulation may generate negative frequency drifting fine structure of AKR.
On the equatorward motion and fading of proton aurora during substorm growth phase
Authors: Liu W. W. , Donovan E. F. , Liang Jun , Voronkov Igor , Spanswick Emma , Jayachandran P. T. , Jackel Brian , Meurant Mathieu
Published: October 2007

Using 50 high‐quality events from the Canadian Auroral Network for the OPEN Program Unified Study (CANOPUS) Gillam Meridian Scanning Photometer over 10 a (1989–1998), we show that proton aurora in the substorm growth phase exhibits a systematic tendency to fade. The average pattern of fading consists of a period of relatively stable proton aurora brightness and then a period of 15–20 min before onset during which the brightness decreases by an average of 15%. We interpret the observed proton aurora brightness variation in terms of the magnetic field stretching in the near‐Earth magnetosphere; in particular, the fading is interpreted as a result of the central plasma sheet magnetic field lines having stretched to such a degree that the loss cone closing effect dominates precipitation due to nonadiabatic proton motions.
Production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl in the Earth's atmosphere by solar and galactic cosmic rays
Authors: Webber W. R. , Higbie P. R. , McCracken K. G.
Published: October 2007

In a follow‐up study to the earlier work of Webber and Higbie (2003) on 10Be production in the Earth's atmosphere by cosmic rays, we have calculated the atmospheric production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl using the FLUKA Monte Carlo code. This new calculation of atmospheric yields of these isotopes is based on 107 vertically incident protons at each of 24 logarithmically spaced energies from 10 MeV to 10 GeV, 102 times the number used in the earlier calculation, along with the latest cross sections. This permits a study of the production due to solar cosmic rays as well as galactic cosmic rays at lower energies where isotope production is a very sensitive function of energy. Solar cosmic ray spectra are reevaluated for all of the major events occurring since 1956. In terms of yearly production of 10Be, only the February 1956 solar event makes a major contribution. For 36Cl these yearly SCR production contributions are 2–5 times larger depending on the solar cosmic ray energy spectra. We have determined the yearly production of 10Be, 36Cl, and other cosmogenic isotopes above 65° geomagnetic latitude for the time period 1940–2006 covering six solar 11‐year (a) cycles. The average peak‐to‐peak 11‐a amplitude of this yearly production is 1.77. The effects of latitudinal mixing alter these direct polar production values considerably, giving an average peak‐to‐peak 11‐a amplitude of 1.48 for the global average production.