bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal convection in faulted extensional sedimentary basins: theoretical results from finite‐element modeling
Authors: Simms M. A. , Garven G.
Published: April 2004

Thermal convection has the potential to be a significant and widespread mechanism of fluid flow, mass transport, and heat transport in rift and other extensional basins. Based on numerical simulation results, large‐scale convection can occur on the scale of the basin thickness, depending on the Rayleigh number for the basin. Our analysis indicates that for syn‐rift and early post‐rift settings with a basin thickness of 5 km, thermal convection can occur for basal heat flows ranging from 80 to 150 mW m−2, when the vertical hydraulic conductivity is on the order of 1.5 m year−1 and lower. The convection cells have characteristic wavelengths and flow patterns depending on the thermal and hydraulic boundary conditions. Steeply dipping extensional faults can provide pathways for vertical fluid flow across large thicknesses of basin sediments and can modify the dynamics of thermal convection. The presence of faults perturbs the thermal convective flow pattern and can constrain the size and locations of convection cells. Depending on the spacing of the faults and the hydraulic properties of the faults and basin sediments, the convection cells can be spatially organized to align with adjacent faults. A fault‐bounded cell occurs when one convection cell is constrained to occupy a fault block so that the up‐flow zone converges into one fault zone and the down‐flow zone is centred on the adjacent fault. A fault‐bounded cell pair occurs when two convection cells occupy a fault block with the up‐flow zone located between the faults and the down‐flow zones centred on the adjacent faults or with the reverse pattern of flow. Fault‐bounded cells and cell pairs can be referred to collectively as fault‐bounded convective flow. The flow paths in fault‐bounded convective flow can be lengthened significantly with respect to those of convection cells unperturbed by the presence of faults. The cell pattern and sense of circulation depend on the fault spacing, sediment and fault permeabilities, lithologic heterogeneity, and the basal heat flow. The presence of fault zones also extends the range of conditions for which thermal convection can occur to basin settings with Rayleigh numbers below the critical value for large‐scale convection to occur in a basin without faults.

The widespread potential for the occurrence of thermal convection suggests that it may play a role in controlling geological processes in rift basins including the acquisition and deposition of metals by basin fluids, the distribution of diagenetic processes, the temperature field and heat flow, petroleum generation and migration, and the geochemical evolution of basin fluids. Fault‐bounded cells and cell pairs can focus mass and heat transport from longer flow paths into fault zones, and their discharge zones are a particularly favourable setting for the formation of sediment‐hosted ore deposits near the sea floor.
Hydrothermal control on organic matter alteration and illite precipitation, Mt Isa Basin, Australia
Authors: Uysal I. T. , Glikson M. , Golding S. D. , Southgate P. N.
Published: April 2004

Abundant illite precipitation in Proterozoic rocks from Northern Lawn Hill Platform, Mt Isa Basin, Australia, occurred in organic matter‐rich black shales rather than in sandstones, siltstones and organic matter‐poor shales. Sandstones and siltstones acted as impermeable rocks, as early diagenetic quartz and carbonate minerals reduced the porosity–permeability. Scanning and transmission electron microscopy (SEM and TEM) studies indicate a relation between creation of microporosity–permeability and organic matter alteration, suitable for subsequent mineral precipitation. K–Ar data indicate that organic matter alteration and the subsequent illite precipitation within the organic matter occurred during the regional hydrothermal event at 1172 ± 50 (2σ) Ma. Hot circulating fluids are considered to be responsible for organic matter alteration, migration and removal of volatile hydrocarbon, and consequently porosity–permeability creation. Those rocks lacking sufficient porosity–permeability, such as sandstones, siltstones and organic matter poor shales, may not have been affected by fluid movement. In hydrothermal systems, shales and mudstones may not be impermeable as usually assumed because of hydrocarbons being rapidly removed by fluid, even with relatively low total organic carbon.
Salinity structure of the central North Slope foreland basin, Alaska, USA: implications for pathways of past and present topographically driven regional fluid flow
Authors: Hanor J. S. , Nunn J. A. , Lee Y.
Published: April 2004

Previous studies of the areal variation in heat flow in the National Petroleum Reserve Alaska (NPRA) support the existence of an active topographically driven regional fluid flow regime in this central part of the North Slope foreland basin. Drilling records and wireline logs for over 30 wells drilled in the NPRA provide additional field information, which can be used to further constrain interpretation of the pattern of regional flow of basinal waters within the NPRA. Hydraulic heads estimated from drilling mud weights show that ground water flow occurs generally from south to north, but with divergence to the north‐east and north‐west away from the central part of the NPRA towards coastal areas of elevated shallow heat flow. Salinities calculated from SP logs range from less than 1 g L−1, to marine values of 35 g L−1, to hypersaline values of over 150 g L−1. The entire upper sedimentary section to a depth of 2 km or more in the eastern part of the NPRA has been preferentially flushed with meteoric water through an area corresponding to the sandiest portion of the Nanushuk group. Deeper areas of low salinity occur within the Sadlerochit and Lisburne sections. The pattern of regional flow in the east is complicated, however, by the presence of a large mass of hypersaline water at depth. It is not known whether these brines are being displaced laterally and upward towards the discharge end of the basin or whether fresher waters are simply riding up over the top. Deep, hypersaline waters also occur in fault slices in the Brooks Range and have survived meteoric flushing. The brines were probably formed at the time of deposition of the Lisburne carbonates. The fluid flow regime to the west is different. Low‐salinity waters may be flowing northward underneath this section through the Ellesmerian section and discharging upward nearer the coast. However, sparse well log control severely limits what can be deduced about the details of flow paths in the central and western parts of the NPRA.
Metamorphic and basin fluids in quartz–carbonate–sulphide veins in the SW Scottish Highlands: a stable isotope and fluid inclusion study
Authors: Anderson R. , Graham C. M. , Boyce A. J. , Fallick A. E.
Published: April 2004

Metalliferous (Fe–Cu–Pb–Zn) quartz–carbonate–sulphide veins cut greenschist to epidote–amphibolite facies metamorphic rocks of the Dalradian, SW Scottish Highlands, with NE–SW to NW–SE trends, approximately parallel or perpendicular to regional structures. Early quartz was followed by pyrite, chalcopyrite, sphalerite, galena, barite, late dolomite–ankerite and clays. Both quartz–sulphide and carbonate vein mineralisation is associated with brecciation, indicating rapid release of fluid overpressure and hydraulic fracturing.

Two distinct mineralising fluids were identified from fluid inclusion and stable isotope studies. High temperature (>350°C) quartz‐precipitating fluids were moderately saline (4.0–12.7 wt.% NaCl equivalent) with low (approximately 0.05). Quartz δ18O (+11.7 to +16.5‰) and sulphide δ34S (−13.6 to −1.1‰) indicate isotopic equilibrium with host metasediments (rock buffering) and a local metasedimentary source of sulphur. Later, low‐temperature (TH = 120–200°C) fluids, probably associated with secondary carbonate, barite and clay formation, were also moderately saline (3.8–9.1 wt.% NaCl equivalent), but were strongly enriched in 18O relative to host Dalradian lithologies, as indicated by secondary dolomite–ankerite (δ18O = +17.0 to +29.0‰, δ13C = −1.0 to −3.0‰). Compositions of carbonate–forming fluids were externally buffered.

The veins record the fluid–rock interaction history of metamorphic host rocks during cooling, uplift and later extension. Early vein quartz precipitated under retrograde greenschist facies conditions from fluids probably derived by syn‐metamorphic dehydration of deeper, higher‐grade rocks during uplift and cooling of the Caledonian metamorphic complex. Veins are similar to those of mesothermal veins in younger Phanerozoic metamorphic belts, but are rare in the Scottish Dalradian. Early quartz veins were reactivated by deep penetration of low‐temperature basin fluids that precipitated carbonate and clays in veins and adjacent Dalradian metasediments throughout the SW Highlands, probably in the Permo‐Carboniferous. This event is consistent with paragenetically ambiguous barite with δ34S characteristic of late Palaeozoic basinal brines.
Emanuel Miller lecture: Confusions and controversies about Asperger syndrome
Authors: Frith Uta
Published: March 2004

Background: Hans Asperger drew attention to individuals who show the core symptoms of autism in the presence of high verbal intelligence.

Methods: A review of the literature explores current issues concerning the diagnosis and nature of Asperger syndrome.

Results: The behavioural and neurophysiological evidence to date suggests that Asperger syndrome is a variant of autism typically occurring in high‐functioning individuals, and not a separate disorder. One of the problems of diagnosis is that the typical impairment of social communication may be difficult to identify in early childhood, and can be camouflaged in adulthood by compensatory learning. The range and nature of the social impairments in Asperger syndrome are still in need of investigation, but appear to be less severe than in autism. Experimental evidence suggests that individuals with Asperger syndrome may lack an intuitive theory of mind (mentalising), but may be able to acquire an explicit theory of mind. Brain imaging studies pinpoint a network that links medial prefrontal and temporal cortex as the neural substrate of intuitive mentalising. This network shows reduced activation and poor connectivity in Asperger syndrome. While some individuals with Asperger syndrome have written eloquently about their lives, their ability to talk about their own emotions appears to be impaired (alexithymia). This impairment may be linked to depression and anxiety, which is common in adulthood. Little is as yet known about the often considerable cognitive strengths in Asperger syndrome, or about the difficulties observed in higher‐level executive skills.

Conclusions: Studies are needed that define the developmental course of the disorder and the nature of the strengths and weaknesses in both social and non‐social domains. This requires more sensitive assessment instruments than are currently available. Questions about the prevalence of Asperger syndrome, about associated and secondary features, and about optimal education and management, urgently call for such studies.
Emotion recognition/understanding ability in hearing or vision‐impaired children: do sounds, sights, or words make the difference?
Authors: Dyck Murray J. , Farrugia Charles , Shochet Ian M. , Holmes‐Brown Martez
Published: March 2004

Background:  This study was designed to assess whether children with a sensory disability have consistent delays in acquiring emotion recognition and emotion understanding abilities.

Method:  Younger (6–11 years) and older (12–18 years) hearing‐impaired children (HI; n = 49), vision‐impaired children (VI; n = 42), and children with no sensory impairment (NSI; n = 72) were assessed with the Emotion Recognition Scales (ERS), which include two tests of the ability to recognize vocal expressions of emotion, two tests of the ability to recognize facial expressions of emotion, and three tests of emotion understanding.

Results:  Results indicate that when compared with age‐peers, HI children and adolescents have significant delays or deficits on all ERS, but VI children and adolescents are delayed only on emotion recognition tasks. When compared with children group‐matched for verbal ability (Wechsler verbal scales), the achievement of HI children on ERS equals or exceeds that of controls; VI children underachieve on an emotion recognition task and overachieve on an emotion vocabulary task compared to verbal ability matched peers.

Conclusions:  We conclude that VI children have a specific emotion recognition deficit, but among HI children, performance on emotion recognition and emotion understanding tasks reflects delayed acquisition of a broad range of language‐mediated abilities.
A questionnaire for screening a broad range of DSM‐defined anxiety disorder symptoms in clinically referred children and adolescents
Authors: Muris Peter , Dreessen Laura , Bögels Susan , Weckx Miryam , van Melick Marion
Published: March 2004

Objective:  To examine the reliability and validity of the 66‐item Screen for Child Anxiety Related Emotional Disorders‐Revised (SCARED‐R), a questionnaire for measuring a broad range of DSM‐defined anxiety disorder symptoms, in a sample of clinically referred youths.

Method:  The SCARED‐R was administered to children/adolescents and their parents during the standard intake assessment. SCARED‐R scores were compared against Child Behavior Checklist (CBCL) scores, DSM‐IV axis I classifications, and global assessment of functioning (GAF) ratings.

Results:  In this sample of clinically referred youths, the SCARED‐R was reliable in terms of internal consistency and showed reasonable child–parent agreement. Furthermore, SCARED‐R scores correlated significantly with CBCL internalising but not with externalising. Within the group of children with anxiety disorders, SCARED‐R scores were also negatively associated with children's daily functioning as rated on the GAF scale. Finally, SCARED‐R scores had satisfactory discriminant validity (both between anxiety disorders and other problems and within anxiety disorders), and appeared to have reasonable value for predicting specific anxiety disorders.

Conclusion:  The SCARED‐R is a valuable addition to the arsenal of questionnaires that are used for the assessment of anxiety in youths.
Social and emotional adjustment of siblings of children with autism
Authors: Pilowsky Tammy , Yirmiya Nurit , Doppelt Osnat , Gross‐Tsur Varda , Shalev Ruth S.
Published: March 2004

Background:  Social and emotional adjustment of siblings of children with autism was examined, to explore their risk or resilience to effects of genetic liability and environmental factors involved in having a sibling with autism.

Method:  Social‐emotional adjustment, behavior problems, socialization skills, and siblings’ relationships were compared among 30 siblings of children with autism, 28 siblings of children with mental retardation of unknown genetic etiology (MR), and 30 siblings of children with developmental language disorders (DLD). Groups were matched by probands’ gender, siblings’ chronological age, gender, IQ, and birth order, and by family size, ethnicity, and parental income, employment, and stress level.

Results:  Four siblings of children with autism, three siblings of children with MR, and seven siblings of children with DLD received DSM‐IV diagnoses. Nevertheless, most of the siblings were well adjusted.

Conclusions:  The adjustment of siblings of children with autism is in sharp contrast to the severe social and emotional disabilities characteristic of autism, and is noteworthy considering the stress involved in having a sibling with autism.
Serpentinites of the Zermatt‐Saas ophiolite complex and their texture evolution
Authors: Li X.‐P. , Rahn M. , Bucher K.
Published: April 2004

The Zermatt‐Saas serpentinite complex is an integral member of the Penninic ophiolites of the Central Alps and represents the mantle part of the oceanic lithosphere of the Tethys. Metamorphic textures of the serpentinite preserve the complex mineralogical evolution from primary abyssal peridotite through ocean‐floor hydration, subduction‐related high‐pressure overprint, meso‐Alpine greenschist facies metamorphism, and late‐stage hydrothermal alteration. The early ocean floor hydration of the spinel harzburgites is still visible in relic pseudomorphic bastite and locally preserved mesh textures. The primary serpentine minerals were completely replaced by antigorite. The stable assemblage in subduction‐related mylonitic serpentinites is antigorite–olivine–magnetite ± diopside. The mid‐Tertiary greenschist facies overprint is characterized by minor antigorite recrystallization. Textural and mineral composition data of this study prove that the hydrated mineral assemblages remained stable during high‐pressure metamorphism of up to 2.5 GPa and 650 °C. The Zermatt‐Saas serpentinites thus provide a well documented example for the lack of dehydration of a mantle fragment during subduction to 75 km depth.
Zoned (Cretaceous and Cenozoic) garnet and the timing of high grade metamorphism, Southern Alps, New Zealand
Authors: Vry J. K. , Baker J. , Maas R. , Little T. A. , Grapes R. , Dixon M.
Published: April 2004

New (garnet Sm–Nd and Lu–Hf) and existing (Rb–Sr, 40Ar/39Ar, U–Pb and Sm–Nd) ages and data on deformational fabrics and mineral compositions show for the first time that the garnet growth and ductile deformation in the Alpine Schist belt and Southern Alps orogen, New Zealand are diachronous and partly Cenozoic in age. The dominant metamorphic isograds in the Alpine Schist formed during crustal thickening at a previously unsuspected time, at c. 86 Ma, immediately prior to the opening of the Tasman Sea at c. 84–82 Ma. Obvious changes in the textures and compositional zoning patterns of garnet are not always reliable indicators of polymetamorphism, and fabric elements can be highly diachronous.

A detailed timing history for the growth of a single garnet is recorded by a Sm–Nd garnet–whole rock age of 97.8 ± 8.1 Ma for the inmost garnet core (zone 1), Lu–Hf ages of 86.2 ± 0.2 Ma and 86.3 ± 0.2 Ma for overgrowth zones 2 and 3, a step‐leach Sm–Nd age of 12 ± 37 Ma for zone 4, and growth of the garnet rim (zone 5) over the Alpine Fault mylonite foliation during the modern phase of oblique collision that began at c. 5–6 Ma.

Plate convergence along the New Zealand portion of the Gondwana margin continued after c. 105 Ma, almost certainly culminating in the oblique collision of a large oceanic plateau (Hikurangi Plateau). The metamorphism of the Alpine Schist at c. 86 Ma is evidence of that hit. The mid‐ to late‐Cretaceous extension that is widespread elsewhere in the New Zealand region is attributed to upper plate extension and slab roll‐back. The effects of the collision with the Hikurangi Plateau may have contributed to the changing plate motions in the region leading up to the opening of the Tasman Sea at c. 82 Ma.
Microboudin structures of piemontite along the Sambagawa metamorphic belt, Japan: implications for lateral variation of differential stress during regional metamorphism
Authors: Masuda T. , Shibutani T. , Ochiai T. , Akagi S. , Yamaguchi H. , Kugimiya Y. , Kimura N. , Miyake T.
Published: April 2004

Evidence is presented of a lateral variation in differential stress during metamorphism along a regional metamorphic belt on the basis of the proportion of microboudinaged piemontite grains (p) in a quartz matrix in metacherts. It is proposed that p is a practical indicator of relative differential stress. Analysis of 123 metacherts from the 800 km long Sambagawa metamorphic belt, Japan, reveals that p‐values range from < 0.01 to 0.7 in this region. Most samples from Wakayama in the mid‐belt area have p‐values of 0.4–0.6, whereas those from western Shikoku have p‐values of < 0.1. This difference cannot be explained by variations in metamorphic temperature, and is instead attributed to a regional, lateral variation in differential stress during metamorphism.
Vertical extrusion and middle crustal spreading of omphacite granulite: a model of syn‐convergent exhumation (Bohemian Massif, Czech Republic)
Authors: Štípská P. , Schulmann K. , Kröner A.
Published: April 2004

The exhumation of eclogite facies granulites (Omp–Plg–Grt–Qtz–Rt) in the Rychleby Mts, eastern Czech Republic, was a localised process initiated by buckling of crustal layers in a thickened orogenic root. Folding and post‐buckle flattening was followed by the main stage of exhumation that is characterized by vertical ductile extrusion. This process is documented by structural data, and the vertical ascent of rocks from a depth ofc.70 toc.35 km is documented by metamorphic petrology. SHRIMP206Pb/238U and207Pb/206Pb evaporation zircon ages of 342 ± 5 and 341.4 ± 0.7 Ma date peak metamorphic conditions. The next stage of exhumation was associated with sideways flat thrusting associated with lateral viscous spreading of granulites and surrounding rocks over indenting adjacent continental crust at a depth ofc.35–30 km. This stage was associated with syntectonic intrusion of a granodiorite sill at 345–339 Ma, emplaced at a crustal depth ofc.25 km. The time required for cooling of the sill as well as for heating of the country rocks brackets this event to a maximum of 250 000 years. Therefore, similar ages of crystallization for the granodiorite magma and the peak of eclogite facies metamorphism of the granulite suggest a very short period of exhumation, limited by the analytical errors of the dating methods. Our calculations suggest that the initial exhumation rate during vertical extrusion was 3–15 mm yr−1, followed by an exhumation rate of 24–40 mm yr−1during further uplift along a magma‐lubricated shear zone. The extrusion stage of exhumation was associated with a high cooling rate, which decreased during the stage of lateral spreading.
Late Miocene movement within the Himalayan Main Central Thrust shear zone, Sikkim, north‐east India
Authors: Catlos E. J. , Dubey C. S. , Harrison T. M. , Edwards M. A.
Published: April 2004

In the Sikkim region of north‐east India, the Main Central Thrust (MCT) juxtaposes high‐grade gneisses of the Greater Himalayan Crystallines over lower‐grade slates, phyllites and schists of the Lesser Himalaya Formation. Inverted metamorphism characterizes rocks that immediately underlie the thrust, and the large‐scale South Tibet Detachment System (STDS) bounds the northern side of the Greater Himalayan Crystallines.In situTh–Pb monazite ages indicate that the MCT shear zone in the Sikkim region was active atc.22, 14–15 and 12–10 Ma, whereas zircon and monazite ages from a slightly deformed horizon of a High Himalayan leucogranite within the STDS suggest normal slip activity atc.17 and 14–15 Ma. Although average monazite ages decrease towards structurally lower levels of the MCT shear zone, individual results do not follow a progressive younging pattern. Lesser Himalaya sample KBP1062A records monazite crystallization from 11.5 ± 0.2 to 12.2 ± 0.1 Ma and peak conditions of 610 ± 25 °C and 7.5 ± 0.5 kbar, whereas, in the MCT shear zone rock CHG14103, monazite crystallized from 13.8 ± 0.5 to 11.9 ± 0.3 Ma at lower grade conditions of 525 ± 25 °C and 6 ± 1 kbar. TheP–T–tresults indicate that the shear zone experienced a complicated slip history, and have implications for the understanding of mid‐crustal extrusion and the role of out‐of‐sequence thrusts in convergent plate tectonic settings.
Origin and evolution of the Escambray Massif (Central Cuba): an example of HP/LT rocks exhumed during intraoceanic subduction
Authors: Schneider J. , Bosch D. , Monié P. , Guillot S. , García‐Casco A. , Lardeaux J. M. , Torres‐Roldán R. Luís , Trujillo G. Millán
Published: April 2004

High‐pressure (HP) metabasites from the Sancti Spiritus dome (Escambray massif, Central Cuba) have been studied in order to better understand the origin and evolution of the Northern Caribbean boundary plate during the Cretaceous, in a global subduction context. Geochemical and petrological studies of these eclogites reveal two groups with contrasting origins and pre‐subduction metamorphic histories. Eclogites collected from exotic blocks within serpentinite (mélange zone) originated from a N‐MORB type protolith, do not record pre‐eclogitic metamorphic history. Conversely eclogites intercalated in Jurassic metasedimentary rocks (non‐mélange zone) have a calc‐alkaline arc‐like origin and yield evidence for a pre‐subduction metamorphic event in the amphibolite facies. However, all the studied Escambray eclogites underwent the same eclogitic peak (around 600 °C at 16 kbar), and followed a cold thermal gradient during their exhumation (estimated at around 13.5 °C km−1), which can suggest that this exhumation was coeval with subduction. Concordant geochronological data (Rb/Sr and Ar/Ar) support that the main exhumation of HP/LT rocks from the Sancti Spiritus dome occurred at 70 Ma by top to SW thrusting. The retrograde trajectory of these rocks suggests that the north‐east subduction of the Farallon plate continued after 70 Ma. The set‐off to the exhumation can be correlated with the beginning of the collision between the Bahamas platform and the Cretaceous island arc that induced a change of the subduction kinematics. The contrasting origin and ante‐subduction history of the analysed samples imply that the Escambray massif consists of different geological units that evolved in different environments before their amalgamation during exhumation to form the present unit III of the massif.
Social Perceptions of Students with Learning Disabilities Who Differ in Social Status
Authors: Meadan Hedda , Halle James W.
Published: April 2004

As a group, students with learning disabilities (LD) have social difficulties. One possible explanation for these difficulties is the unique way they process social information. Although students with LD may differ from their nondisabled peers in their social cognition, investigators have suggested the presence of subgroups within the population of students with LD who may differ in their social competence and, thereby, shed light on the source of the difficulties. The present exploratory study examined how two subgroups of students with LD in inclusive settings, students with high and low social status, perceive social situations. Using a sociometric technique, three students with LD receiving high social‐status ratings and three students with LD receiving low social‐status ratings were identified. A qualitative approach was used to gather and evaluate data from the participants and their teachers. Results suggested differences between the two subgroups in their (1) sensitivity to cues in the environment, (2) interpretation of social situations in relation to their own experiences, and (3) levels of self‐control. Implications of these findings for practice and future research are discussed.
Is Inclusion an Illusion? An Examination of National and State Trends Toward the Education of Students with Learning Disabilities in General Education Classrooms
Authors: McLeskey James , Hoppey David , Williamson Pamela , Rentz Tarcha
Published: April 2004

The inclusion of students with learning disabilities (LD) remains one of the more controversial issues in special education. Although research evidence seems to reveal that students with LD should spend most of the school day in the general education classroom, little data are available regarding the extent to which states are moving toward educating these students in less restrictive settings. This investigation was conducted to examine national and state data related to changes that occurred during the 1990s in educating students with LD in less restrictive settings. The results revealed that little change occurred across the United States as a whole, and that only 15 states moved toward educating students with LD in less restrictive settings during this time. The findings of this investigation further revealed that much of the apparent movement toward educating students with LD in general education classrooms is largely an illusion, explained primarily by the increasing identification rate for students with LD. The implications of these findings for future research and practice are discussed.
Assessing the impact of oral health on the life quality of children: implications for research and practice
Authors: McGrath Colman , Broder Hillary , Wilson‐Genderson Maureen
Published: April 2004

Abstract –

Traditionally, child oral health has been assessed using clinical parameters of disease and deformity. However, there is a growing interest in the psychosocial impact of oral health among children. This commentary outlines the value and need for assessing child oral health‐related quality of life (COHQoL). COHQoL has implications for oral health needs assessment (at an individual and population level) and for evaluating outcomes from specific treatments, initiatives and dental services overall. In addition, it could prove to be a useful adjunct tool for evidence‐based dentistry research and practice. Theoretical and practical considerations in assessing the complex psychosocial construct of oral health among children are discussed: the use of general versus oral health‐specific measures, the development of tools for children, the use of generic versus condition‐specific measures, and the measurement of ‘positive’ oral health. Recommendations for research and practice are presented.
Faculty development for problem‐based learning
Authors: Farmer Elizabeth A.
Published: April 2004

Changing to a problem‐based learning (PBL) curriculum represents a substantial challenge because many faculty members are unfamiliar with the process. Faculty development is a crucial component of successful curriculum change to PBL. This paper describes a logical process for designing and implementing a comprehensive faculty development programme at three main stages of change: curriculum transition, curriculum implementation and curriculum advancement. The components of each stage are discussed with reference to the literature and practice. Future advances in faculty development include harnessing the potential of complex adaptive systems theory in understanding and facilitating the change process, and incorporating the results of research, which illuminates the relationships of the PBL tutorial process to student achievement. There is a continuing need for rigorous outcome‐based research and programme evaluation to define the best components and strategies for faculty development.
Reflective practice in the teaching of conservative dentistry to undergraduate dental students – perceptions derived from a pilot study using personal development diaries
Authors: Robinson P. B. , Davies B. R.
Published: April 2004

The aim of this study was to explore final‐year student perceptions to the use of personal development diaries (PDDs) and to compare the findings with an established system of competitive continuous assessment, using open display of score ratings displayed on a clinic notice board. Focus groups in conjunction with personal development diaries (PDDs) were used to investigate the teaching of conservative dentistry to senior dental undergraduates. Thirty per cent of the statements made reference to the positive aspects of PDDs, while a small percentage (6%) was negative. Nineteen per cent of the comments derived from the focus groups showed that the undergraduates disliked the open display of their marks on the conservation clinic notice board. This compared with only 2% who claimed that they enjoyed the competitive method. A further 22% of the comments related to the fact that open display of marks was stressful, whereas 3% were unaffected. Eighteen per cent of the responses indicated that clinical conservative dentistry was a stressful experience.
Evaluation of the Malmö‐Model‐Former Graduates' Perception
Authors: Nilner* M , Rohlin* M.
Published: April 2004

The aim was to evaluate graduates' perception with a problem‐based curriculum in dental education.

We surveyed past graduates from the first five courses (graduated between 1994‐1999) regarding their perception with the curriculum in Malmö. The survey included demographic data, questions targeted on their under‐graduate education, questions on their professional practice and present support for competence development education. The graduates were asked to answer short questions and mark on a VAS ranging from ‘not at all’ (0) to ‘quite well’ (10). We used reply envelopes with real first‐class stamps. Until now there were 110 responses (70% response rate).

The great majority (92%) considered the education to prepare them well (above 6 on the VAS) for their profession. Over 90% rated their education higher than 6 on the VAS. The short answers on strengths and weaknesses of the education are presently being analysed. It was obvious that the level of professional satisfaction was high (90% of the answers being 6–10). Their answers on whether they could influence their present working situation were very spread, from not at all to quite well. The extent to which they can influence their own as well as their team's competence development was on the other hand rather high.

Based on the results of this evaluation and of two other evaluations, which will also be elucidated, we conclude that the Malmö‐model meets the needs of the dental professional well.
External Examiners and Immediate Post Qualification Clinical Dental Training in Europe
Authors: Moody G. H.
Published: April 2004

Background:  A conversation at the ADEE Conference in Bern, 2001, revealed an apparent diversity in the use and role of External Examiners in dental undergraduate examinations in ADEE‐associated schools. There also appeared to be considerable variation in the amount of post‐graduate supervised clinical training.

Aims:  (i) To elicit information on the use of External Examiners in dental undergraduate examinations. (ii) To acquire information about immediate post‐qualifying supervised clinical experience and training.

Method:  Questionnaire to the 205 Dental Schools listed in the ADEE Directory in 35 European countries.

Results:  Eighty‐two (40%) completed questionnaires were returned.

Of these 82 schools, 43 (52.4%) did not use External Examiners. The remaining 39 (47.6%) used an External Examiner at least once during the under‐graduate course. All 39 used an External Examiner in ‘Finals’, 34 in all clinical examinations and 30 in pre‐clinical examinations.

Thirty out of 39 allowed external examiners to scrutinize papers before the examination.

Although 31/39 were asked to advise on problems during examinations, only 26/39 were consulted about the fate of ‘failed’ candidates and 23/39 asked to adjudicate in such instances.

Following qualification, graduates from 38/82 schools experienced some form of supervised further clinical training ranging from 3 months to 2 years. The majority (21/38) were trained for 1 year and 13 for 2 years.

However, 30/82 (36.5%) schools produced graduates who qualified without any external assessment and without the benefit of any post‐qualifying supervised training.

Conclusions:  Although the questionnaire response rate is low, it is clear that there are disparities in practice with regard to the use of external examiners and post‐graduate training, which need to be evaluated if dental undergraduate standards in Europe are to converge.
Towards a Competency‐Based Curriculum in Turkey: Students' Reflection
Authors: Ozer F. , Karakaya S. , Altinoz C.
Published: April 2004

Dental education has undergone major change over the years in Turkey. Only lately has emphasis been placed on development of a competency‐based program in the curriculum. Educational methods are still traditional with mainly lecture‐based teaching. A curriculum revision is a continuous process with ongoing evaluation. As an influence of DentEd visit to the Faculty, greater emphasis was given on staff–student interaction in learning activities. The purpose of the present study was to obtain student views of some component of the current curriculum of the faculty in Konya/Turkey. A questionnaire was handed out to the final‐year students. The questionnaire was completed by 91.8% of the students and had five sections: (i) Personal information (age, sex); (ii) Information about parents education; (iii) Information about the decision to study dentistry; (iv) Information about the dental curriculum; and (v) Information about the teachers and clinical instructors. Our results indicated that almost half of the students (51.1%) chose the dental education by their own desire. But 64.4% of students did not want to suggest dental education to others. The majority of students (88.7%) felt themselves well experienced or competent except oral surgery, orthodontics and endodontics. But their basic complain was about the education in dental emergencies and internal medicine. 42.2% of students were not satisfied by the educational methods of their teachers. The rating was even higher in clinical instructors (51.1%). More than one‐half of the class (55.6%) informed that they had big difficulties in practical trainings. Most of the students (94.6%) complained about not having any spare time for their hobbies. We can conclude that the school should have a major impact on quality assurance and development, which is based on internal processes of evaluation and review.
Topics of Special Interest in an Emergency Medicine Course for Dental Practice Teams
Authors: Weber S. , Müller M. , Koch T.
Published: April 2004

Considering increasing life expectancy and population comorbitity, not only dentists but also nursing staff should gain knowledge and skills in treatment of patients in acute life‐threatening situations. In cooperation with the State Dental Council, a 1‐day course in the management of medical emergencies based on the ERC ALS guidelines was held for primary care dental practice teams.

Following a short lecture series (2 hours), a systematic skills‐training session (6 hours) was performed in small groups, addressing the following subjects: BLS, airway management and ventilation, intravenous techniques, manual and automated external defibrillation, ALS and resuscitation routine in a typical dental practice setting. For all skills‐training sessions, life‐like manikins and models were utilized and the emergency scenarios were simulated by the use of a universal patient simulator (SimMan®, MPL/Laerdal).

At the end of the course, an evaluation questionnaire was completed by all candidates to find out in which emergency situations the dental practice teams now felt well trained or incompetent.

In the first course with 32 participants, 13 were dentists and 19 were dental nurses. In the evaluation results, 53% of both, dentists and nurses, stated to be competent in cardiac arrest situations. 95% of the nurses, but only 69% of the dentists, thought that an automated external defibrillator should be available in the dental practice. 26% of the dentists felt unable to treat patients with anaphylactic reactions adequately, whereas 37% of the nurses felt incompetent in respiratory emergencies.
Class II restorations in primary teeth: 7‐year study on three resin‐modified glass ionomer cements and a compomer
Authors: Qvist V. , Laurberg L. , Poulsen A. , Teglers P. T.
Published: March 2004

The aim of this randomized study was to compare the longevity and cariostatic effects of 1565 class II restorations in primary teeth placed by 15 clinicians in the Danish Public Dental Health Service in 971 children, aged 3.6–14.9 yr. The restorations were performed using three resin‐modified glass ionomer cements and one compomer (polyacid‐modified composite resin) with and without their respective cavity conditioners. The restorations were in contact with 1023 unrestored proximal surfaces in 853 primary and 170 permanent teeth. The study was terminated after 7 yr with 1% of the restorations in function, 7% patient dropouts, 18% failed restorations, and operative treatment on 24% of the adjacent surfaces. Multivariate survival analyses showed that the restorative material and cavity conditioning influenced the survival of restorations but not the progression of caries on adjacent surfaces. The 50% survival times were estimated to exceed 5 yr for the restorations and 4.5 yr for the adjacent unfilled surfaces in all treatment groups. It was concluded that resin‐modified glass ionomer cement and compomer are both appropriate materials for class II restorations in primary teeth. The differences in longevity and cariostatic effects among the four materials used with and without conditioner were less than the intra‐individual differences between clinicians.
Model of the viscoelastic behaviour of skin in vivo and study of anisotropy
Authors: Khatyr Fouad , Imberdis Claude , Vescovo Paul , Varchon Daniel , Lagarde Jean‐Michel
Published: April 2004

Background: The single‐axis extension test is relatively little used to study the mechanical properties of human skin in vivo. A campaign of tests was carried out with an original, modern machine developed in our laboratory. It can perform extension or compression tests using servo‐controlled position or force in different directions. The load can either be of the extension or monotonous compression type, creep or relaxation. The results obtained were used to develop a viscoelastic model. The elastic modulus calculated helps us to determine the main directions of anisotropy on the forearm.

Methods: We use a new in vivo single‐axis extension machine (patent no. FR03/09220 application in progress). With it, we can carry out monotonous, creep and relaxation tests on the forearm. An associated finite elements model enables conversion to the intrinsic parameters of the skin under stress and strain from external stress applied in force and displacement. From the tests, we can propose a viscoelastic model and the identification of his parameters. We carried out tests in four directions with respect to the axis of the forearm of 63 people of different ages.

The present report is limited to a brief presentation of the experimental set‐up used, and a more complete presentation of the viscoelastic model and how it is defined and also the work on the anisotropy in the elastic domain.

Results: The viscoelastic model proposed has only four intrinsic parameters: elasticity parameters Ee and Eve and viscosity parameters ɛve and A. Skin being considered as orthotropic, we were able to determine the average main direction of 63 people, which is of 5.33±5.78 around the longitudinal axis of the arm. An average modulus E1 (ave)=6.57E5 (Pa) can be found in the direction close to the axis of the arm and E2 (ave)=1.30E5 (Pa) in the perpendicular direction and a G12=1.32E5 (Pa) shear modulus.

Conclusions: The parameters obtained with the viscoelastic model are independent of the type of load, the same coefficients enable a correct representation in creep and relaxation tests. The main directions vary from one person to another, Young's modulus in these directions could be an indicator for dermatologists and cosmeticians.
Use of an intraluminal guide wire in linear microdialysis probes: effect on recovery?
Authors: Klimowicz Adam , Bielecka‐Grzela Stanislawa , Groth Lotte , Benfeldt Eva
Published: April 2004

Background/purpose: For microdialysis studies in the skin, laboratory‐made linear probes are often used. Probes can be assembled with or without a stainless‐steel guide wire in the lumen of the dialysis fibre. From a theoretical viewpoint, this will alter the performance of the probe. The aim of this study was to compare the in vitro microdialysis recovery using probes with and without an internal guide wire, employing two different model drugs and a range of perfusate flow rates.

Methods: In vitro microdialysis recovery experiments were performed with and without internal guide wires at perfusion flow rates from 1 to 15 μL/min, using either salicylic acid or metronidazole as test compounds at 5 mg/L. Phosphate buffer (pH 7.4) was used as perfusate. Dialysates were analysed by a validated HPLC assay with spectrophotometric detection.

Results: For both test compounds, the mean microdialysis recovery did not differ significantly between microdialysis probes with and without an internal guide wire at lower flow rates. At very high flow rates (10–15 μL/min), a significant difference in recovery could be seen for probes with internal guide wires when compared with probes without.

Conclusion: The use of a stabilizing internal guide wire in linear microdialysis probes did not influence the in vitro recovery of microdialysis at volumetric flow rates below 10 μL/min. These are the flow rates most frequently used for in vivo microdialysis studies in the skin.
Mid‐infrared in vivo depth‐profiling of topical chemicals on skin
Authors: Notingher Ioan , Imhof Robert E.
Published: April 2004

Background/purpose: Thermal emission decay–Fourier transform infrared (TED–FTIR) spectroscopy is a non‐contact and non‐destructive analytical technique and was used in this study to detect the presence of external chemicals on human skin in vivo. The detection was possible due to the ability of the TED–FTIR technique to acquire the mid‐infrared spectrum of the outmost layers (less than 10 μm) of Stratum Corneum (SC) and the ability to identify the absorption bands of the chemical.

Methods: As an illustration of such measurements, propylene glycol (PG) was applied on human stratum corneum and depth‐resolved TED–FTIR spectra of the SC were measured to quantify the concentration of PG in deeper layers of SC.

Results: The mid‐infrared spectrum of the surface 0.7 μm layer of skin had 50% contribution from SC and 50% from PG. At 3 h after application, the contribution of PG at the surface decreased to 7% as PG molecules diffused deeper into the skin and were lost at the surface. At a depth of 6 μm, the maximum concentration was 20% after 25 min after PG application.

Conclusions: This work shows the feasibility of the TED–FTIR technique to detect the presence of chemicals on human SC in vivo and without contact, and for a wide range of other applications, such as detection of toxic chemicals used as warfare (vesicant agents like sulphur mustard and organophosphate nerve agents), pesticides, and other toxins on fruit and vegetable skins, water, or even other contaminated surfaces.
Functional Properties ofBorrelia burgdorferi recA
Authors: Liveris Dionysios , Mulay Vishwaroop , Schwartz Ira
Published: April 2004

Functions of theBorrelia burgdorferiRecA protein were investigated inEscherichia coli recAnull mutants. Complementation withB. burgdorferi recAincreased survival ofE. coli recAmutants by 3 orders of magnitude at a UV dose of 2,000 μJ/cm2. The viability at this UV dose was about 10% that provided by the homologousrecAgene. Expression ofB. burgdorferi recAresulted in survival ofE. coliat levels of mitomycin C that were lethal to noncomplemented hosts.B. burgdorferiRecA was as effective asE. coliRecA in mediating homologous recombination inE. coli. Furthermore,E. coliλ phage lysogens complemented withB. burgdorferi recAproduced phage even in the absence of UV irradiation. The level of phage induction was 55-fold higher than the level in cells complemented with the homologousrecAgene, suggesting thatB. burgdorferiRecA may possess an enhanced coprotease activity. This study indicates thatB. burgdorferiRecA mediates the same functions inE. colias the homologousE. coliprotein mediates. However, the rapid loss of viability and the absence of induction inrecAexpression after UV irradiation inB. burgdorferisuggest thatrecAis not involved in the repair of UV-induced damage inB. burgdorferi. The primary role of RecA inB. burgdorferiis likely to be a role in some aspect of recombination.