bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Dynamic Secondary Electron Contrast Effects from Insulators in Low Vacuum SEM
Authors: Thiel B , Tatem E
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
The Effect of Heating on the Surface Charge of Copper Oxide Nanorods
Authors: Gangopadhyay S , Shende R , Hasan S , Ross Jr. LM
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Structure and Function of Icosahedral Pyruvate Dehydrogenase Complexes
Authors: Milne J , Wu X , Borgnia M , Lengyel J , Shi D , Perham R , Subramaniam S
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
EM Specimen Preparation of Nanoparticles Using Ultrasonic Spray Technique
Authors: Lai L-C , Chiou W-A , Tsai S-C , Song Y-L , Chou Y-F , Tsai C-S
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Studies of Bimetallic (Pt, Ru) Catalysts with Aberration-Corrected STEM and Theory
Authors: Borisevich A , Buczko R , Rashkeev S , Wang S , Pantelides S , Pennycook S
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
HAADF Studies of the Si3N4 IGF Interface
Authors: Cockayne D , Winkelman G , Dwyer C , Doblinger M
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Nanostructured Conducting Polymer Coatings for Biomedical Devices
Authors: Martin D , Abidian M , Hendricks J , Richardson-Burns S , Meier M , Kim D , Yang J
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Enhanced High Speed SE Imaging in a VPSEM Using a Frisch Grid
Authors: Phillips MR , Morgan SW
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Center for Nanophase Materials Sciences
Authors: Horton L
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Transcending the One-Ångström Atomic Resolution Barrier in the TEM
Authors: O'Keefe MA , Allard LF , Pennycook SJ , Blom DA
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Low Voltage and Low Vacuum- When worlds Collide
Authors: Thiel B , Tileli V
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Focused Ion Beam as a Nanofabrication Tool for Rapid Prototyping of Nanomagnetic Devices
Authors: Khizroev S , Lavrenov A , Amos N , Chomko R , Litvinov D
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Microscopic Molecular Machines Help Bacteriophages to Package Their Genomes and Infect Their Hosts
Authors: Leiman PG , Fokine A , Chipman PR , Kostyuchenko VA , Kanamaru S , Arisaka F , Mesyanzhinov VV , Rossmann MG
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Chemomechanical Mapping of Biopolymers and Cells
Authors: Vliet KJ Van , Tweedie CA , Thompson MT , Lee SY
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Measurement of k-value in Semiconductor Structures
Authors: Potapov PL , Engelmann H-J , Zschech E
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Fidelity of radially viewed ICP‐OES and magnetic‐sector ICP‐MS measurement of Mg/Ca and Sr/Ca ratios in marine biogenic carbonates: Are they trustworthy together?
Authors: Andreasen Dyke H. , Sosdian Sindia , Perron‐Cashman Suzanne , Lear Caroline H. , deGaridel‐Thoron Thibault , Field Paul , Rosenthal Yair
Published: October 2006

Improving interlaboratory reproducibility (in both precision and accuracy) of Mg/Ca and Sr/Ca determination in marine biogenic carbonates is critical in optimizing their utility as paleothermometers. Coupled with a need for uniform sample cleaning practices, there is a need for more exacting methods and procedures across laboratories using varied instrumentation. Here we employ an intensity ratio/matrix‐effect correction methodology to a suite of solution standards and biogenic carbonates (foraminifera tests and a gastropod shell) to investigate short‐term and long‐term Mg/Ca and Sr/Ca precision and accuracy by different instruments: a magnetic‐sector inductively coupled plasma–mass spectrometer (ICP‐MS) and a radially viewed inductively coupled plasma–optical emission spectrophotometer (ICP‐OES). Over an extended 1.0–24.5 mM Ca concentration range, both instruments have significant Ca matrix effects for Mg/Ca and somewhat less for Sr/Ca. Over our working Ca range (1–8 mM Ca), Mg/Ca matrix effects are significant, requiring correction, and Sr/Ca matrix effects are small to negligible, occasionally requiring correction (linear or logarithmic fit) using a suite of matrix standards for both instruments. The short‐term (intrarun) precision for a suite of solution standards is <0.2% (1σ %RSD) for Mg/Ca and Sr/Ca for both instruments. A long‐term (interrun) precision of <0.9% is demonstrated for Mg/Ca and <0.6% for Sr/Ca on both instruments. The accuracy of measured Mg/Ca and Sr/Ca values for short‐ and long‐term standards is similar on both instruments at better than 1 ± 0.5%, on par with our long‐term precision. An interinstrument comparison of the same measured suite of biogenic carbonates demonstrates that after accounting for matrix effects, data generated on either instrument are essentially interchangeable (within analytical precision) to a high degree of fidelity.
Validation of MODIS aerosol observations over the Netherlands with GLOBE student measurements
Authors: Boersma K. F. , de Vroom J. P.
Published: October 2006

We have established a network of secondary schools in the Netherlands with students routinely measuring aerosol optical thickness (AOT) at two wavelengths with hand‐held Sun photometers. Students have performed more than 400 measurements between January 2002 and October 2005 over more than 12 locations within the Netherlands as a contribution to Global Learning and Observations to Benefit the Environment (GLOBE). We have developed an improved AOT retrieval algorithm that accounts for the effective wavelength of the broad‐band GLOBE detectors and for the spatiotemporal variation of ozone. Results from a theoretical error analysis indicate that GLOBE measurements achieve a precision better than 0.02 AOT for both channels. Comparisons with professional instruments generally give high correlations and low scatter and bias. From these tests, we conclude that student data are scientifically valid and may be used to validate MODIS AOT retrievals over the Netherlands. We find that over land, MODIS AOT is biased by +0.03 (470 nm) and −0.01 AOT (660 nm). Over coastal areas, MODIS overestimates AOT by 0.10 (470 nm) and 0.08 AOT (660 nm). Seasonally averaged MODIS observations over northwestern Europe show relatively highest AOT values over the region of Flanders and the Netherlands, with a seasonal cycle peaking in spring/summer. Our study shows the potential of secondary school‐based networks in addition to existing, professional networks that have much less spatial coverage.
Low temperature magnetic susceptometer based upon a dc superconducting quantum interference device
Authors: Read Dan , Terry Ian , Giblin Sean R.
Published: October 2006

A low temperature magnetic susceptometer was constructed by combining an Oxford Instruments Heliox probe sorption pumped He3 cryostat with a Quantum Design model 5000 dc superconducting quantum interference device sensor, giving an effective temperature range from 300mKto4.2K. The smallest resolvable change in magnetic moment detected by this system was found to be Δ∼1×10−12JT−1 (1×10−9emu).
RAFT-Mediated Emulsion Polymerization of Styrene using a Non-Ionic Surfactant
Authors: Urbani Carl N. , Nguyen Hang N. , Monteiro Michael J.
Published: October 2006

We report the successful RAFT-mediated emulsion polymerization of styrene using a non-ionic surfactant (Brij98), the highly reactive 1-phenylethyl phenyldithioacetate (PEPDTA) RAFT agent, and water-soluble initiator ammonium persulfate (APS). The molar ratio of RAFT agent to APS was identical in all experiments. Most of the monomer was contained within the micelles, analogous to microemulsion or miniemulsion systems but without the need of shear, sonication, cosurfactant, or a hydrophobe. The number-average molecular weight increased with conversion and the polydispersity index was below 1.2. This ideal ‘living’ behavior was only found when molecular weights of 9000 and below were targeted. It was postulated that the rapid transportation of RAFT agent from the monomer swollen micelles to the growing particles was fast on the polymerization timescale, and most if not all the RAFT agent is consumed within the first 10% conversion. In addition, it was postulated that the high nucleation rate from the high rate of exit (of the R radical from the RAFT agent) and high entry rate from water-phase radicals (high APS concentration) reduced the effects of ‘superswelling’ and therefore a similar molar ratio of RAFT agent to monomer was maintained in all growing particles. The high polydispersity indexes found when targeting molecular weights greater than 9000 were postulated to be due to the lower nucleation rate from the lower weight fractions of both APS and RAFT agent. In these cases, ‘superswelling’ played a dominant role leading to a heterogeneous distribution of RAFT to monomer ratios among the particles nucleated at different times.
Housing Policy Reform: A Constructive Critique
Authors: Yates Judith
Published: October 2006

This paper critically evaluates reforms which have been proposed to counter the effects of the growing imbalance between direct and indirect assistance for housing. It proposes a radical restructuring of assistance based on a form of support which enables the shelter and asset components of housing to be separated and assistance to be directed solely towards the former. The policy proposal consists of several essential components: these are a housing cost insurance scheme (providing a housing allowance financed by the taxation of housing income), the provision of shared equity arrangements and the introduction of housing bonds.
Financial Deregulation and Access to Home Ownership in Australia
Authors: Wood Gavin A. , Bushe-Jones Shane
Published: October 2006

Since the deregulation of Australian Housing Finance interest rates in early 1986 the market has determined the rate prospective home buyers must meet for their loans. Deregulation has brought higher interest rates and considerable public discussion concerning the plight of home buyers and these interest rate rises. The paper analyses post-1985 interest rate, house price and incomes data from six capital cities, and computes movements in the deposit gap (the difference between borrowing capacity and house prices). The empirical work demonstrates that, by the fourth quarter of 1988, house price inflation was the major factor contributing to a widening of the deposit gap.
Mismatch in the Housing Market
Authors: Allen Chris , Milne Alistair
Published: October 2006

An economic model is presented of the rise of mortgage arrears and possessions. This indicates that the normal level of possessions is around 30 000 dwellings per year, but that between 1990 and 1996 an additional 300 000 households will exit the owner-occupied housing market. This short-term but substantial outflow from the owner-occupied housing market is producing a mismatch between empty dwellings remaining unsold and growing queues for accommodation from local authorities and housing associations. It is argued that this mismatch is economically inefficient and that it can be addressed through an increase in government expenditure to facilitate the transfer of dwellings out of the owner-occupied housing market.
Natural classification of knots
Authors: Flammini Alessandro , Stasiak Andrzej
Published: October 2006

The principal objective of the knot theory is to provide a simple way of classifying and ordering all the knot types. Here, we propose a natural classification of knots based on their intrinsic position in the knot space that is defined by the set of knots to which a given knot can be converted by individual intersegmental passages. In addition, we characterize various knots using a set of simple quantum numbers that can be determined upon inspection of minimal crossing diagram of a knot. These numbers include: crossing number; average three-dimensional writhe; number of topological domains; and the average relaxation value.
Transcriptional organization, regulation and role of the Porphyromonas gingivalis W83 hmu haemin-uptake locus
Authors: Lewis Janina P. , Plata Konrad , Yu Fan , Rosato Adriana , Anaya Cecilia
Published: October 2006

Porphyromonas gingivalis, an oral bacterium associated with periodontal disease, requires haemin for growth. Although several multigenic clusters encoding haemin-uptake systems are present on the genome ofP. gingivalis, little is known regarding their transcriptional organization and expression. This study identified a 23 kDa iron-regulated haemin-binding protein encoded by a larger than previously reported variant ofhmuY. It was shown that thehmulocus is larger than previously reported and is composed of six genes,hmuYRSTUV, encoding a novel hybrid haemin-uptake system. The locus has an operonic organization and the transcriptional start site is located 292 bp upstream ofhmuY. The data indicate that the regulation of the operon is iron-dependent. Interestingly, differential regulation within the operon was demonstrated, resulting in excess of thehmuYRmessage encoding the outer-membrane proteins when compared to the full-length transcript. In addition, thehmuYtranscript is more prevalent than thehmuRtranscript. Secondary structure analysis of thehmuYRSTUVmRNA predicted the formation of several potential stem–loops in the 5′ ends ofhmuR- andhmuS-specific mRNAs, consistent with the differential regulation observed. Finally, it was demonstrated that haemin binding and uptake are elevated in iron-depleted conditions and are reduced 45 % and 70 %, respectively, in anhmu-deficient strain when compared to the parental strain, indicating that thehmulocus plays a major role in haemin acquisition inP. gingivalis. Since homologues of thehmulocus were also found inBacteroides fragilis,Bacteroides thetaiotaomicronandPrevotella intermedia, these findings may have implications for a better understanding of haemin acquisition in those organisms as well.
Genetic tools for highly pathogenic Francisella tularensis subsp. tularensis
Authors: LoVullo Eric D. , Sherrill Lani A. , Perez Lanyn L. , Pavelka Martin S.
Published: October 2006

This paper is the first detailed description of the development and use of new genetic tools specifically for the safe manipulation of highly pathogenicFrancisella tularensissubsp.tularensis. Most of these tools are also demonstrated to work with otherF. tularensissubspecies. Kanamycin and hygromycin resistance determinants that function as genetic markers inF. tularensissubsp.tularensisstrain Schu and sets of episomal shuttle vectors that are either unstable or stably maintained in the absence of selection were developed. In addition, thehyggene, expressed from theF. tularensis groESLpromoter, was successfully used as a marker for transposon mutagenesis. This work also includes the development ofsacB-based suicide plasmids expressing kanamycin resistance that can be used for electroporation-mediated allelic exchange of unmarked mutations in Schu and theF. tularensislive vaccine strain (LVS). Using these plasmids, the two predictedβ-lactamase genes,blaAandblaB, in Schu and LVS were deleted. Only the ΔblaB1mutants had increased susceptibility to ampicillin, and this phenotype was complemented by a plasmid expressingblaB+. The results suggest that theβ-lactam antibiotic resistance phenotype of Schu and LVS is likely due to only one of the twoβ-lactamase genes present and that ampicillin resistance can be used as an additional selectable marker inβ-lactamase deletion mutants. The collection of tools presented in this report will be helpful for the genetic analyses ofF. tularensissubsp.tularensispathogenesis.
Misconceptions about parsimony analysis of endemicity
Authors: Nihei Silvio Shigueo
Published: October 2006

Parsimony analysis of endemicity (PAE) has been widely criticized in the recent literature based on methodology rather than on theory. Here I argue that most of the criticisms of PAE result from confusion between thedynamicandstaticapproaches of PAE, by both users and critics of the method. Originally, PAE (the dynamic approach) was proposed primarily for historical comparisons of biotic distributions based on geological and stratigraphical information; that is, the stratigraphical record of the biota within two or more horizons was used to evaluate changes (layer by layer) in their distributional patterns. This led to an analysis of the biota throughout space and through time. On the other hand, the static approach excluded the temporal component and based the analysis on a single geological horizon. Most problems exemplified and discussed in the literature refer to the static approach. In addition to this defence of the original PAE, I present some new criticisms regarding the application of PAE using artificially delimited areas (for example areas defined by geopolitical boundaries), which may lead to incorrect interpretations. Recently, several variations of static PAE have appeared: some designed to accommodate ecological data (e.g. parsimony analysis of distributions – PAD); others that incorporate phylogenetic content (e.g. cladistic analysis of distributions and endemism – CADE); and some that have been integrated with other historical methods (e.g. panbiogeography) in order to detect and evaluate hypotheses of biogeographical homologies. Biogeographers, both ecological and historical, should be aware of the problems and limitations of both dynamic and static PAE and evaluate new variations of PAE (PAD, CADE, etc.). Finally, I argue in favour of an independent and pluralist discipline of biogeography that treats biogeography as related to systematics but not dependent on it, as some scholars have assumed.
Seasonal variations in maternal mortality in Maputo, Mozambique: the role of malaria
Authors: Romagosa Cleofé , Ordi Jaume , Saute Francisco , Quintó Llorenç , Machungo Fernanda , Ismail Mamudo R. , Carrilho Carla , Osman Nafissa , Alonso Pedro L. , Menendez Clara
Published: October 2006

Objective  To evaluate the impact of malaria on maternal death through the analysis of the seasonal variations of crude and malaria‐specific maternal mortality rates.

Methods  All maternal deaths and live births occurring at Maputo Central Hospital, located in an urban area, between January 2001 and December 2003, were retrospectively recorded. Clinical diagnoses of the causes of death and period of the year were analysed.

Results  Two hundred and seventy‐eight deaths were recorded. The overall crude maternal mortality rate was 995/100 000 live births. Malaria was the most frequent cause of maternal death, accounting for 23%. Crude and malaria‐specific maternal mortality rates showed a similar pattern of seasonal variation, with peaks at the beginning and the end of the malaria transmission season. The malaria‐specific maternal mortality rate was significantly higher during the rainy seasons (rate ratio 1.919; 95% CI 1.061, 3.470; P = 0.031).

Conclusions  Malaria may contribute to maternal mortality in highly endemic countries in sub‐Saharan Africa, at least in urban areas. Efforts to improve malaria control in pregnancy may have an impact on maternal mortality in sub‐Saharan Africa.
Traditional practices and exposure to bodily fluids in Lusaka, Zambia
Authors: Wojcicki Janet M. , Kankasa Chipepo , Mitchell Charles , Wood Charles
Published: October 2006

Objectives  To ascertain if there are specific sociocultural and behavioural practices associated with the exposure to saliva, semen and vaginal fluids, particularly through child‐rearing practices and the use of traditional medicine in Lusaka, Zambia.

Methods  We conducted 11 focus group discussions with men and women from diverse ethnic and socioeconomic backgrounds (n = 105) in Lusaka, Zambia in March 2004. We also conducted a brief sociodemographic survey of all focus group participants.

Results  Discussions indicated that saliva was used while engaging in home health care practices associated with childcare and the use of traditional medicine. Additionally, semen and vaginal fluids may be used in rituals associated with childcare and health care for children. Our survey indicated that the use of traditional medicine is associated with lower socioeconomic status.

Conclusions  Population‐based studies are needed to evaluate the relationship between traditional behavioural and sociocultural practices, which involve exchange of saliva and other bodily fluids and risk of infectious disease.
Assessing Attachment Security at Age Three: Q‐sort Home Observations and the MacArthur Strange Situation Adaptation
Authors: Posada German
Published: October 2006

The construction of developmentally appropriate and valid assessments is central to the study of attachment relationships beyond infancy. A common procedure has been that of validating new measures for older children against strange situation classifications obtained in infancy. Although reasonable, a key criterion against which to validate new measures should include concurrent secure base behavior in naturalistic settings. The purpose of this study was to investigate whether three‐year‐olds' (N = 45) ability to use their mother as a secure base at home was related to their strange situation classifications when using the MacArthur classification system. Behavior in the strange situation was coded by two experts, and independent observers described secure base behavior at home with the attachment Q‐Set. Results indicated that strange situation classifications were not related to either global q‐set security scores or specific scale scores that reflect the quality of child–mother interactions at home.
Event‐related potentials during mental imagery of animal sounds
Authors: Wu Jianhui , Mai Xiaoqin , Chan Chetwyn C.H. , Zheng Yaqin , Luo Yuejia
Published: October 2006

To investigate the neural correlates of imagined animal sounds, event‐related potentials (ERPs) were recorded while subjects were presented with (1) animal pictures without any imagery instruction (control) or (2) animal pictures with instructions to imagine the corresponding sounds (imagery). The results revealed imagery effects starting with an enhancement of the P2, possibly indexing the top‐down allocation of attention to the imagery task, and continuing into a more positive‐going deflection in the time window of 350–600 ms poststimulus, probably reflecting the formation of auditory imagery. A centro‐parietally distributed late positive complex (LPC) was identified in the difference waveform (imagery minus control) and might reflect two subprocesses of imagery formation: sound retrieval from stored information and representation in working memory.
Comparison of the effectiveness of a nitrification inhibitor, dicyandiamide, in reducing nitrous oxide emissions in four different soils under different climatic and management conditions
Authors: Di H. J. , Cameron K. C. , Sherlock R. R.
Published: October 2006

Nitrous oxide (N2O) is a potent greenhouse gas and, in New Zealand, about one‐third of the total greenhouse gas emissions from the agricultural sector are of N2O, mostly derived from animal excreta in grazed pasture soils. The aim of this study was to determine the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in reducing N2O emissions from animal urine patches in four different soils located in different regions of New Zealand with different soil, climatic and management conditions. The four soils are Templeton fine sandy loam and Lismore stony silt loam in Canterbury in the South Island, Horotiu silt loam in the Waikato region and Taupo pumice sand near Lake Taupo, both in the North Island. Results showed that the application of a fine‐particle suspension nitrification inhibitor, DCD, to grazed pasture soils was very effective in reducing N2O emissions in all four different soils. Total N2O emissions (over 69–137 days) from animal urine patches ranged from 1 to 20.9 kg N2O‐N ha−1 without DCD. These were reduced to 0.31–5.7 kg N2O‐N ha−1 by the use of DCD, representing 61–73% reductions (with an average of 70% reduction). The N2O‐N emission factor from animal urine N, EF3, was reduced from an average of 0.9 to 0.3% by the use of DCD. These results demonstrate the potential of using nitrification inhibitors to mitigate N2O emissions in a wide range of grazed pasture soils under different climatic and management conditions.
Response of soil exchangeable and crop potassium concentrations to variable fertilizer and cropping regimes in long‐term field experiments on different soil types
Authors: Andersson S. , Simonsson M. , Mattsson L. , Edwards A. C. , ÖBorn I.
Published: October 2006

Annual potassium (K) balances have been calculated over a 40‐year period for five field experiments located on varying parent materials (from loamy sand to clay) in south and central Sweden. Each experiment consisted of a number of K fertilizer regimes and was divided into two crop rotations, mixed arable/livestock (I) and arable only (II). Annual calculations were based on data for K inputs through manure and fertilizer, and outputs in crop removal. Plots receiving no K fertilizer showed negative K balances which ranged from 30 to 65 kg ha−1 year−1 in rotation I, compared with 10–26 kg ha−1 year−1 for rotation II. On sandy loam and clay soils, the K yield of nil K plots (rotation I) increased significantly with time during the experimental period indicating increasing release of K from soil minerals, uptake from deeper soil horizons and/or depletion of exchangeable soil K (Kex). Significant depletion of Kex in the topsoil was only found in the loamy sand indicating a K supply from internal sources in the sandy loam and clay soils. On silty clay and clay soils, a grass/clover ley K concentration of ∼2% (dry weight) was maintained during the 40‐year study period on the nil K plots, but on the sandy loam, loam and loamy sand, herbage concentrations were generally less than 2% K.
Psychosocial Interventions for Maltreated and Violence‐Exposed Children
Authors: Cohen Judith A. , Mannarino Anthony P. , Murray Laura K. , Igelman Robyn
Published: October 2006

Child sexual, physical, and emotional abuse as well as child neglect and domestic violence, community violence, and Childhood Traumatic Grief may result in significant and long‐lasting emotional and behavioral difficulties. This article reviews randomized controlled studies that have assessed child mental health outcomes for maltreated and violence‐exposed children. Key points of this review include the following: (1) maltreated and violence‐exposed children typically experience more than one of these types of traumas; (2) effective psychosocial treatments are available to address Posttraumatic Stress Disorder (PTSD), depression, anxiety, and behavioral problems in these children; (3) it is likely that treatments which effectively reduce mental health symptoms in children exposed to one type of child maltreatment or violence exposure will also be effective for other or multiple types; and (4) mental health outcomes are not the only important outcomes to address in future treatment or intervention efforts. These future directions for treatment intervention research are addressed.
Subjective Need for Implant Treatment among Middle‐aged People in Sweden and Denmark
Authors: Kronström Mats , Palmqvist Sigvard , Söderfeldt Björn , Vigild Merete
Published: October 2006

Background: The use of oral implants in prosthodontics has become widespread and regarded as a predictable treatment modality. However, there is a lack of knowledge among the general population about the prevalence and need for implant treatments.

Purpose: This study was undertaken to register and compare the prevalence of dental implants and the subjective need for implant treatment among people in Sweden and Denmark.

Materials and Methods: Random samples taken from the national population registers in Sweden and Denmark comprised 1001 Swedish subjects aged 55 to 79 years and 1175 Danish subjects aged 45 to 69 years. Subjects were requested to fill out questionnaires regarding dental conditions, subjective need for implant treatment, whether they had received treatment with dental implants during the previous 10 years, and so on.

Results: Of the Swedes, 4.8% reported that they had dental implants, compared with 2.5% of the Danes. In the Swedish sample, age was significantly associated with subjective need for implant treatment. In the Danish sample, women showed a significantly higher subjective need for implant treatment than did men.

Conclusions: Compared with the Swedish sample, the subjective need for treatment with dental implants was higher in the Danish sample, although the patient fees were substantially higher in Denmark.
Enhanced Periodontal Response and Esthetics of Implant‐Supported Bridge by the Use of Galvanoforming Technique: Case Report
Authors: Tietmann Christina , Broseler Frank
Published: October 2006

Background: Galvanoforming restorations have been placed over the past 15 years successfully. They offer several advantages over alloy restorations, including enhanced response to the periodontal tissues, biocompatibility, and superior esthetics.

Purpose: The purpose of this report is to show the use of the galvanoforming process in dental implant restorations to transfer the benefits of this technique.

Materials and Methods: Two standard Branemark fixtures were placed submerged in the lower mandible for the restoration of a three‐unit bridge. The impression was taken at fixture level, and two cast individual telescope abutments were inserted. The galvanoforming restoration was seated conventionally without any screw retention.

Results: An implant‐supported galvanoforming bridge is functioning successfully. The use of biocompatible materials does not compromise the stability of the restoration; instead, the effect on the periodontal tissues is excellent, resulting in less plaque accumulation and bleeding on probing. Microgaps were avoided by conventional seating on the individual telescope gold abutments, revealing superior occlusal esthetics.

Conclusions: This case report demonstrates the practicability of the biocompatible galvanoforming procedure for implant‐supported restorations enhancing periodontal response and esthetics.
Clinical Experience of CNC‐Milled Titanium Frameworks Supported by Implants in the Edentulous Jaw: A 3‐Year Interim Report
Authors: Örtorp Anders , Jemt Torsten
Published: October 2006

Background: The use of computer numeric controlled (CNC)‐milled titanium frameworks is a new technique for framework fabrication, and few clinical reports have been made on this treatment modality.

Purpose: The goal of this study was to report the clinical performance of implant‐supported prostheses with CNC‐milled titanium frameworks in the edentulous jaw and to compare the results with prostheses provided with conventional cast frameworks during the first 3 years of function.

Materials and Methods: A consecutive group of 126 edentulous patients were provided by random distribution with 67 prostheses with CNC‐milled titanium frameworks in 23 upper and 44 lower jaws and 62 conventional prostheses with gold‐alloy castings in 31 upper and 31 lower jaws. Radiographic 1‐year data and clinical 3‐year data were collected for both the titanium and control group.

Results: One prosthesis was lost in each group owing to loss of implants, and the overall 3‐year prosthesis cumulative survival rate was 98.2% for both groups. Patients with smoking habits experienced significantly more implant failures than nonsmokers (p =.006). Few problems were observed. No metal fractures were seen in the test group, whereas two frameworks and one abutment screw fractured in the control group. Resin veneer fractures were the most common complication, with a slightly higher incidence observed in the control group.

Conclusions: Computer numeric controlled‐milled titanium frameworks can be used as an alternative to conventional castings in the edentulous jaw, presenting clinical performance similar to that of conventional cast frameworks during the first 3 years of function.
Early Loading of Maxillary Fixed Cross‐Arch Dental Prostheses Supported by Six or Eight Oxidized Titanium Implants: Results after 1 Year of Loading, Case Series
Authors: Olsson Morgan , Urde Göran , Andersen Jan B. , Sennerby Lars
Published: October 2006

Background:

Recent reports have demonstrated that immediate/early loading of dental implants is a clinically feasible concept with results similar to those for two‐stage procedures, at least in good bone qualities. However, documentation of the outcome of immediate/early loading in the totally edentulous maxilla is scarce.

Purpose:

The present investigation was undertaken to evaluate the outcome over 1 year of oxidized titanium implants when loaded with a fixed full‐arch bridge in the maxilla 1 to 9 days after implant placement.

Materials and Methods:

Ten patients with totally edentulous maxillas were treated with 61 oxidized titanium implants, and a provisional fixed bridge was delivered after 1 to 9 days (mean 2.5 d). Nine patients had six implants and one patient had eight implants supporting the bridge. The provisional bridge was replaced with a permanent bridge after 2 to 7 months (mean 4.1 mo) of loading. Resonance frequency analysis (RFA) for implant stability measurements was made at implant placement in eight patients and in conjunction with permanent bridge connection in five patients. The patients were followed up for 1 year with clinical and radiographic examinations.

Results:

Four implants (6.6%) were lost in one patient after 10 weeks of loading owing to an infection. All other implants were clinically stable with a mean marginal bone loss of 1.3 ± 0.6 mm after 1 year of loading. RFA showed a mean primary stability of 60.1 ± 3.6 ISQ (implant stability quotient), which increased to 62.8 ± 1.6 ISQ after, on average, 4 months.

Conclusions:

The results from this limited study on 10 cases indicate that early loading protocols can be applied for cross‐arch dental bridges supported by six to eight implants in the maxilla. However, more clinical trials are needed to establish the long‐term predictability of the treatment.
Tissue Reactions to Abutment Shift: An Experimental Study in Dogs
Authors: Abrahamsson Ingemar , Berglundh Tord , Sekino Satoshi , Lindhe Jan
Published: October 2006

Background: Standard protocols for the clinical use of dental implants often include the placement of healing abutments prior to standard or custom‐made abutments. The tissue response to a single shift from a healing abutment to a permanent abutment has not been studied.

Purpose: The aim of the present experiment was to study tissue reactions that may occur following the removal of a healing abutment and the placement of a permanent abutment.

Materials and Methods: In six beagle dogs, all mandibular premolars were extracted. Three months later three fixtures of the Astra Tech Implants Dental System (Astra Tech AB, Mölndal, Sweden) were installed in each edentulous premolar region. An additional 3 months later, the first abutment connection was performed. In two sites on each side of the mandible, healing abutments were placed; in the remaining site, a Uni‐abutment (Astra Tech AB) was used. The two healing abutments were removed 2 weeks later, and one Uni‐abutment and one prepable abutment were placed. A plaque‐control period was initiated, and 6 months later block biopsies were obtained. The biopsies were prepared for histometric and morphometric examination. Radiographs were obtained at fixture placement, 2 weeks after the first abutment connection, and 6 months later.

Results: The length of the barrier epithelium, the height of the connective tissue attachment, and the level of the marginal bone did not differ between the three abutment groups. The major part of the radiographic bone loss during the experiment took place prior to or immediately after abutment connection; only small bone level alterations occurred during the subsequent 6‐month period.

Conclusions: The shift from a healing abutment to a permanent abutment resulted in the establishment of a transmucosal attachment, the dimension and quality of which did not differ from those of the mucosal barrier formed to a permanent abutment placed during a second‐stage surgery.
Early Functional Loading of Unsplinted Roughened Surface Implants with Mandibular Overdentures 2 Weeks after Surgery
Authors: Payne Alan G.T. , Tawse‐Smith Andrew , Thompson W. Murray , Kumara Rohana
Published: October 2006

Background: Before early functional loading of unsplinted implants with mandibular overdentures can become widespread, more clinical studies are needed to investigate the success of the approach.

Purpose: To evaluate the success rates of two types of roughened titanium surface implants with early 2‐week functional loading of paired mandibular interforaminal implants with overdentures.

Materials and Methods: Random allocation divided 24 strictly selected edentulous participants into two groups, with each group to receive a different implant system (ITI Dental Implant System, Straumann AG, Waldenburg, Switzerland; or Southern Implant System, Southern Implants, Irene, South Africa). Two implants were placed in the anterior mandible of all participants using one‐stage standardized surgical procedures. Previously constructed conventional mandibular dentures (opposing maxillary complete dentures) were temporarily relined and worn by the participants for the first 2 weeks; participants used a soft diet. Two weeks after implant surgery and following some mucosal healing, the mandibular dentures had the tissue conditioner removed and the appropriate matrices included for an unsplinted prosthodontic design.

Results: No implant from either group was lost. Resonance frequency analysis (RFA) indicated higher primary stability at surgery for the Southern group than for the ITI group, with a statistically significant difference between the groups throughout the study period. The drop in RF values between surgery and 6 weeks was significant and was greater for the Southern group. RFA also indicated stabilized osseointegration between 6 to 12 and 12 to 52 weeks, with no participant showing any decrease in those values over time. Participants with type 3 bone showed a significant improvement in RF values between 12 and 52 weeks, eventually matching those of participants with type 2 bone. There were no significant differences in marginal bone loss, periimplant parameters, or prosthodontic maintenance between the groups over the study period.

Conclusions: Using only strict patient selection criteria, 1‐year follow‐up data indicate that early functional loading of ITI and Southern implants with mandibular two‐implant overdentures is possible as early as 2 weeks after implant surgery.
An Image‐Guided System Based on Custom Templates: Case Reports
Authors: Blanchet Eric , Lucchini Jean‐Pierre , Jenny Rene , Fortin Thomas
Published: October 2006

Background:

With the use of computer‐assisted surgery and other modern imaging technologies, the surgeon's procedures have been modified.

Purpose:

The purpose of these case reports is to show the clinical predictability of dental implant placement using an image‐guided system.

Material and Methods:

An acrylic template is made on the patient model. After computed tomographic examination, a treatment plan is established with appropriate software. To fabricate the surgical template, it is necessary to use a dedicated drilling machine. The first osteotomy is achieved through the template with a 2 mm twist drill. The template is then removed, and the osteotomy is completed, followed by implant placement with standard clinical procedures.

Results:

An excellent predictability was observed between the planned implants and those placed in the two maxillary cases presented: a full upper screw‐retained bridge and two single units.

Conclusions:

This new technology improves the treatment outcome and optimizes the surgical procedure.
Fracture Resistance of Endodontically Treated Teeth Restored with Three Different Prefabricated Esthetic Posts
Authors: MACCARI PAULO C. A. , CONCEIÇÃO EWERTON N. , NUNES MAURO F.
Published: October 2006

Purpose: This study was undertaken to evaluate the role of composition of prefabricated esthetic posts in fracture resistance of endodontically treated teeth in vitro.

Materials and Methods: Thirty human, single‐rooted teeth (maxillary central incisors and canines) with similar root dimensions, extracted for therapeutic reasons, were used in this study. The crowns were removed below the cementoenamel junction to obtain a standard root length of 17 mm. The roots were endodontically treated following the conventional manual technique and randomly assigned to three groups (n = 10) according to the post used: Aestheti‐Post, Bisco, Schaumberg, Illinois; FibreKor Post, Jeneric/Pentron, Wallingford, Connecticut; and CosmoPost, Ivoclar Vivadent, Schaan, Liechtenstein. The root canals were rendered patent, and the root preparations were standardized through flaring with the manufacturers' drills included in the respective kits. The posts were cemented with an adhesive system and a resin cement (All‐Bond 2 and C & B, Bisco, respectively), according to the manufacturers' directions. Composite resin (Tetric Ceram, Ivoclar Vivadent) crowns were built up using a preformed polyester matrix, and the specimens were mounted in metallic rings with cold‐cure acrylic resin and kept in saline solution at 4°C for 24 hours. Fracture resistance was then determined using an EMIC DL‐2000 universal testing machine. The crosshead speed was 0.5 mm/min with the 45‐degree compressing load at the middle third of the crown. Data were analyzed using one‐way analysis of variance and Tukey'stest (p<.001).

Results: Mean fracture resistance was as follows: Aestheti‐Post, 83.5 kgf; FibreKor Post, 85.7 kgf; and CosmoPost, 36.5 kgf. The fracture strength of CosmoPost was significantly lower than that of the other posts. Teeth restored with CosmoPost had post fractures, and in three specimens, those were associated with root fractures. Teeth restored with the other two posts presented fractures on the composite crowns.

CLINICAL SIGNIFICANCE

Compared with ceramic posts, carbon‐fiber and glass‐fiber prefabricated esthetic posts provide endodontically treated teeth higher fracture resistance.
Color Measurements as Quality Criteria for Clinical Shade Matching of Porcelain Crowns
Authors: DANCY WM KEVIN , YAMAN PETER , DENNISON JOSEPH B. , O'BRIEN WILLIAM J. , RAZZOOG MICHAEL E.
Published: October 2006

Statement of Problem: The ability of a dentist to select and communicate an acceptable shade match to a dental laboratory may be the most important factor in esthetic restorative dentistry. Purpose: The purpose of this study was to evaluate the use of instrumental color measurement in clinical shade matching of porcelain‐fused‐to‐metal (PFM) and all‐porcelain crowns. The relative effects of clinical and laboratory factors related to shade matching for PFM and all‐porcelain crowns were also evaluated.

Materials and Method: Forty patients treatment planned to receive PFM or all‐porcelain crowns made up the study population/The patients were randomly divided into two groups for shade selection: conventional visual assessment and photocolorimetric analysis. At the preparation appointment, a photograph was taken of the target tooth along with four shade guide tabs selected by the two visual observers. The crown was fabricated by either visual selection or by the lowest E* values determined from the photographs and a spectrophotometer. The same dental laboratory fabricated all 40 restorations. At the cementation appointment, clinical criteria were used to evaluate anatomy/contour, surface texture, and the amount of glaze as it relates to color perception before the restoration was cemented.

Results: The mean E* between the reference tooth before preparation and the crown before cementation in the visual assessment group was 10.49 (± 14.6), whereas the mean E* in the photocolorimetric group was 8.99 (± 5.7). Analysis of data showed that the observers and the colorimetric technique were perfect (E* = 0) 41% of the time and varied (E* = 0.1 or higher) 59% of the time. Data collected further showed no significant difference or correlation between shade selection methods and the evaluated clinical criteria.

Conclusions: These results provide evidence that there is no significant difference in shade selection using the conventional visual assessment by two experienced clinicians or the photocolorimetric technique.

CLINICAL SIGNIFICANCE

The use of photocolorimetric analysis in shade selection can serve as a reliable alternative to conventional visual shade selection. This method is useful for clinicians who have difficulty with shade selection.
Shear Bond Strength of Enamel Treated with Seven Carbamide Peroxide Bleaching Agents
Authors: BASTING ROBERTA TARKAN. , RODRIGUES JOSÉ AUGUSTO , SERRA MÔNICA CAMPOS , PIMENTA LUIZ ANDRÉFREIRE
Published: October 2006

Purpose::

Lower average values of bond strength of adhesive systems to enamel bleached with 10% carbamide peroxide agents have been reported, but the effects of higher concentrations of carbamide peroxide bleaching agents are still unknown. The aim of this in vitro study was to evaluate the shear bond strength of enamel treated with different concentrations of carbamide peroxide to an adhesive system after a postbleaching period of storage in artificial saliva for 15 days.

Materials and Methods:

Seven carbamide peroxide bleaching agents with concentrations varying from 10 to 22% were analyzed. A placebo agent was used as a control group. The agents were applied on the enamel fragments for 8 h/d for 42 days. During the remaining time, the specimens were stored in artificial saliva. After that time, the fragments were stored individually in artificial saliva for 15 days. An adhesive system was used to bond resin‐based composite cylinders on the enamel surface. Shear bond strength tests were performed and the fractured surfaces of the specimens were visually examined with a stereomicroscope at ×30.

Results:

The analysis of variance did not show differences in shear bond strength among the treatment agents. The fractures for all treatment agents were predominantly adhesive.

Conclusion:

After 15 days storage in artificial saliva, different concentrations of carbamide peroxide bleaching agents and a placebo agent had the same enamel shear bond strength values.