bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo Influence of Residual Moisture on Microtensile Bond Strengths of One‐Bottle Adhesives
Authors: PERDIGÃO JORGE , GERALDELI SAULO , CARMO ANDRÉ R.P. , DUTRA HÉLIO R.
Published: June 2007

Purpose: This study evaluated the microtensile bond strengths of three dentin adhesives applied on clinically moist dentin or on dentin that was dried with air for 5 seconds. The null hypothesis to test was that the level of residual moisture does not influence bond strengths when restorations are placed in vivo.

Materials and Methods: Twenty‐four premolars scheduled to be extracted for orthodontic reasons from patients between the ages of 15 and 23 years were restored with one of the following adhesive systems followed by a mini hybrid composite resin: Excite (Ivoclar/Vivadent), an ethanol‐based dentin adhesive; Prime & Bond NT (Dentsply/Caulk), an acetone‐based dentin adhesive; and Single Bond (3M ESPE), an ethanol and water‐based dentin adhesive. After extraction, the specimens were sectioned with a slow‐speed diamond saw in two perpendicular directions to obtain sticks with a cross‐section of 0.7 ± 0.2 mm2. The specimens were attached to a Geraldeli device and fractured using a universal testing machine at a crosshead speed of 1 mm per minute.

Results: For each dentin adhesive, there were no statistical differences between means for dry dentin versus moist dentin. Single Bond and Prime & Bond NT ranked in the same statistical subset regardless of the moisture condition of the substrate. Both Excite, dry, and Excite, moist, resulted in statistically lower bond strengths than Single Bond, moist, but similar to those of Single Bond, dry, Prime & Bond NT, moist, and Prime & Bond NT, dry.

CLINICAL SIGNIFICANCE

In this study, the level of residual moisture did not influence microtensile bond strengths. Clinically, the degree of moisture left on the dentin surface upon rinsing off the etching gel may not be as relevant as previously reported in laboratory studies.
Shear Bond Strength of Bis‐acryl Composite Provisional Material Repaired with Flowable Composite
Authors: HAGGE MARK S. , LINDEMUTH JAMES S. , JONES AMMON G.
Published: June 2007

Background: Time and expense are considerable when refabrication of a bis‐acryl composite provisional prosthesis is required, so an effective method of repair is desirable. Attempts at self‐repair have been ineffective, and no reports of repair specific to bis‐acryl composites were found in the literature.

Purpose: To investigate the strength of a bis‐acryl composite repair using flowable composite after two surface treatments and three storage conditions.

Materials and Methods: Thirty specimens of bis‐acryl composite were made and divided into six groups. Half of the specimens received air abrasion only, and half received air abrasion followed by application of an intermediate bonding resin. A flowable composite was then applied to all specimens. Following three different storage conditions, the flowable composite was debonded using a universal testing machine in tensile mode.

Results: All specimens failed cohesively within the bis‐acryl composite rather than at the repair interface. Surface treatment with air abrasion alone resulted in significantly higher shear bond strength values than when air abrasion and intermediate bonding resin were combined. Bond strength values were significantly higher in thermocycled specimens than in air‐dried specimens.

Conclusions: Use of air abrasion followed by application of flowable composite proved to be a successful technique for bis‐acryl composite repair.
Effects of Four Prophylaxis Pastes on Surface Roughness of a Composite, a Hybrid Ionomer, and a Compomer Restorative Material
Authors: WARREN DONNA P. , COLESCOTT TARA DEBNER , HENSON HAROLD A. , POWERS JOHN M.
Published: June 2007

Purpose: This study was undertaken to compare the effects of three prophylaxis pastes (Nupro with coarse, medium, or fine pumice) with a new paste (Clinpro with perlite) on the surface roughness of a resin composite (Dyract AP), a hybrid ionomer (Fuji II LC), and a compomer (TPH Spectrum).

Materials and Methods: Twenty disks (2 mm thick ± 10 mm in diameter) of each material were prepared in split molds and stored for 24 hours at 37°C in a 100% relative humidity humidistat. Baseline Mylar surface roughness values were determined. A single operator polished each specimen for 10 seconds with each paste. Five tracings of each specimen of surface roughness (Ra, μm) were made using a surface profilometer. Means and standard deviations were calculated, and analyzed by two‐way analysis of variance (three restorative materials and four prophylaxis pastes as factors) and compared using Tukey‐Kramer intervals calculated at the 0.05 level of significance.

Results: Analysis of variance showed significant differences among restorative materials (after polishing) and prophylaxis polishing agents. Tukey‐Kramer intervals for comparisons were 0.04 and 0.05 μm, respectively. All polishing agents produced significant increased roughness compared with baseline, yielding the following results (X + SD, μm) for the three restorative materials (Fuji II LC, TPH Spectrum, Dyract AP): perlite, 0.16 ± 0.07, 0.28 ± 0.26, 0.79 ± 0.64; course pumice, 0.36 ± 0.17, 0.48 ± 0.25, 0.88 ± 0.46; medium pumice, 0.26 ± 0.10, 0.35 ± 0.30, 0.46 ± 0.21; and fine pumice, 0.16 ± 0.06, 0.34 ± 0.30, 0.42 ± 0.24). Fine pumice and perlite produced the least roughness on the hybrid ionomer, medium and fine pumice on the resin composite, and perlite on the compomer.

CLINICAL SIGNIFICANCE

Since prophylaxis pastes have the potential to increase the surface roughness of resin composite, hybrid ionomer, and compomer restorative materials, routine polishing during prophylaxis should be avoided.
Safety Issues When Using a 16% Carbamide Peroxide Whitening Solution
Authors: LEONARD RALPH H. , GARLAND GLENN K. , EAGLE JAMES C. , CAIMAN DANIEL J.
Published: June 2007

Background: The scientific literature is lacking on the occurrence of side effects and other safety issues when using carbamide peroxide whitening solutions of concentrations greater than 10%. This double‐blind nightguard vital bleaching study compares safety issues when using 16% carbamide peroxide against a placebo or 10% carbamide peroxide (Nite White Classic by Discus Dental Inc.). Evaluated were changes in gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosal index, tooth vitality, and the patients' perceptions of tooth sensitivity and gingival irritation.

Materials and Methods: Twenty female dental hygiene students participated in the study. Each participant wore a maxillary treatment tray for 1 week without any solution and then for 8 to 10 hours per night for 14 nights, filling each quadrant with placebo, 10% carbamide peroxide, or 16% carbamide peroxide, using a split tray design.

Results: With respect to gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosa index, tooth vitality, and tooth sensitivity, there were no statistically significant differences between the 16% carbamide peroxide solution and the other two solutions (p > .05). Quadrants receiving the 16% carbamide peroxide solution experienced more gingival irritation than quadrants receiving placebo or 10% carbamide peroxide solution (p > .05).

Conclusions: When evaluating the above‐mentioned safety issues, except for gingival irritation, there were no statistically significant differences between a 16% carbamide peroxide solution and 10% carbamide peroxide solution or a placebo when used as described here.

CLINICAL SIGNIFICANCE

Among the 20 participants whose data were analyzed, it was found that a 16% carbamide peroxide whitening solution (Nite White Classic), when used as described in this study, can be effective in nightguard vital bleaching with no statistical differences in gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosa changes, tooth vitality, or tooth sensitivity, compared with a 10% whitening solution (Nite White Classic). More gingival irritation was experienced with 16% carbamide peroxide. Additionally, 20% of the participants in this study self‐reported sensitivity when wearing their treatment tray without any solution, and 36% of the participants reported sensitivity to the placebo solution.
Dynesthetic and Dentogenic Concept Revisited
Authors: JAMESON WILLIAM S.
Published: June 2007

The dynesthetic and dentogenic concept, when applied, provides a more natural, harmonious prosthesis, which not only is desired by patients, but also is a quality of care they deserve. Outstanding esthetics can be achieved by simple guidelines, using tooth molds specifically sculpted for males and females, arranging prosthetic teeth to correspond with personality and age and sculpting the matrix (visible denture base) with more natural contours. There is no reason for edentulous individuals to be provided with care of any less quality than that available with other procedures, such as crowns, bridges, veneers, or implant restorations. Providing this upscale product can be rewarding and satisfying to patient and operator alike. This concept produces superior results no matter what posterior occlusal scheme is employed but, in the opinion of the author, works best when used in conjunction with a noninterceptive linear occlusion approach (not to be confused with lingualized occlusion), which precludes anterior contact.

CLINICAL SIGNIFICANCE:

Dentogenics provides an approach to esthetics in prosthodontics that enables the dentist to create a restoration in harmony with the patient's objective personality. This concept considers gender, I age, and personality to restore the patient's dignity and unique individuality that has been missing in far too many prostheses.
Polymerization Efficiency of LED Curing Lights
Authors: LEONARD DANIEL L. , CHARLTON DAVID G. , ROBERTS HOWARD W. , COHEN MARK E.
Published: June 2007

ABSTRACT: Purpose: The purpose of this study was to compare the curing efficiency of three commercially available light‐emitting diode (LED)‐based curing lights with that of a quartz tungsten halogen (QTH) curing light by means of hardness testing. In addition, the power density (intensity) and spectral emission of each LED light was compared with the QTH curing light in both the 380‐to 520‐nm and the 450‐ to 500‐nm spectral ranges.

Materials and Methods: A polytetrafluoroethylene mold 2 mm high and 8 mm in diameter was used to prepare five depth‐of‐cure test specimens for each combination of exposure duration, composite type (Silux Plus [microfill], Z‐100 [hybrid]), and curing light (ZAP Dual Curing™ Light, LumaCure™, VersaLux™, Optilux 401™). After 24 hours, Knoop hardness measurements were made for each side of the specimen, means were calculated, and a bottom/top Knoop hardness (B/T KH) percentage was determined. A value of at least 80% was used to indicate satisfactory polymerization. A linear regression of B/T KH percentage versus exposure duration was performed, and the resulting equation was used to predict the exposure duration required to produce a B/T KH percentage of 80% for the test conditions. The power densities (power/unit area) of the LED curing lights and the QTH curing light (Optilux 401™) were measured 1 mm from the target using a laboratory‐grade, laser power meter in both the full visible light spectrum range (380–780 nm) and the spectral range (between 450 and 500 nm), using a combination of long‐ and short‐wave edge filters.

Results: The emission spectra of the LED lights more closely mirrored the absorption spectrum of the commonly used photoinitiator camphorquinone. Specifically, 95% of the emission spectrum of the VersaLux, 87% of the LumaCure, 84% of the ZAP LED, and 78% of the ZAP combination LED and QTH fell between 450 and 500 nm. In contrast, only 56% of the emission spectrum of the Optilux 401™ halogen lamp fell within this range. However, the power density between 450 and 500 nm was at least four times greater for the halogen lamp than for the purely LED lights. As I a result, the LED‐based curing lights required from 39 to 61 seconds to cure a 2‐mm thick hybrid I resin composite and between 83 and 131 seconds to adequately cure a microfill resin composite. By I comparison, the QTH light required only 21 and 42 seconds to cure the hybrid and microfill resin I composites, respectively.
POSTERIOR RESIN‐BASED COMPOSITE RESTORATIONS: A SECOND OPINION
Authors: Croll Theodore P. , Cavanaugh Richard R. , Pedley R Denison
Published: June 2007

“The direction of the decay may be superficial or deep, as the extent of caries varies not only in different teeth but in die different tissues of an individual tooth. The structure of the enamel and dentine differs very much in density, and this fact largely accounts for the slowness, or rapidity of caries; the tissue with the greatest amount of organic material is more rapidly disorganised, so that it is not uncommon to find, in preparing a cavity for filling, that a comparatively small hole in the enamel leads down to a large unexpected, or at all events previously unknown, excavation in the dentine. In some cases the decay is so rapid that the first intimation is the collapse of a large portion of the crown, when the dentine below may be found to be a caseous mass…”
An intermediate step in the evolution of ATPases − the F1F0‐ATPase from Acetobacterium woodii contains F‐type and V‐type rotor subunits and is capable of ATP synthesis
Authors: Fritz Michael , Müller Volker
Published: June 2007

Previous preparations of the Na+ F1F0‐ATP synthase solubilized by Triton X‐100 lacked some of the membrane‐embedded motor subunits [Reidlinger J & Müller V (1994) Eur J Biochem233, 275–283]. To improve the subunit recovery, we revised our purification protocol. The ATP synthase was solubilized with dodecylmaltoside and further purified to apparent homogeneity by chromatographic techniques. The preparation contained, along with the F1 subunits, the entire membrane‐embedded motor with the stator subunits a and b, and the heterooligomeric c ring, which contained the V1V0‐like subunit c1 and the F1F0‐like subunits c2 and c3. After incorporation into liposomes, ATP synthesis could be driven by an electrochemical sodium ion potential or a potassium ion diffusion potential, but not by a sodium ion potential. This is the first demonstration that an ATPase with a V0–F0 hybrid motor is capable of ATP synthesis.
A vertebrate slow skeletal muscle actin isoform
Authors: Mudalige Wasana A. K. A. , Jackman Donna M. , Waddleton Deena M. , Heeley David H.
Published: June 2007

Salmonids utilize a unique, class II isoactin in slow skeletal muscle. This actin contains 12 replacements when compared with those from salmonid fast skeletal muscle, salmonid cardiac muscle and rabbit skeletal muscle. Substitutions are confined to subdomains 1 and 3, and most occur after residue 100. Depending on the pairing, the ‘fast’, ‘cardiac’ and rabbit actins share four, or fewer, substitutions. The two salmonid skeletal actins differ nonconservatively at six positions, residues 103, 155, 278, 281, 310 and 360, the latter involving a change in charge. The heterogeneity has altered the biochemical properties of the molecule. Slow skeletal muscle actin can be distinguished on the basis of mass, hydroxylamine cleavage and electrophoretic mobility at alkaline pH in the presence of 8 m urea. Further, compared with its counterpart in fast muscle, slow muscle actin displays lower activation of myosin in the presence of regulatory proteins, and weakened affinity for nucleotide. It is also less resistant to urea‐ and heat‐induced denaturation. The midpoints of the change in far‐UV ellipticity of G‐actin versus temperature are ∼ 45 °C (‘slow’ actin) and ∼ 56 °C (‘fast’ actin). Similar melting temperatures are observed when thermal unfolding is monitored in the aromatic region, and is suggestive of differential stability within subdomain 1. The changes in nucleotide affinity and stability correlate with substitutions at the nucleotide binding cleft (residue 155), and in the C‐terminal region, two parts of actin which are allosterically coupled. Actin is concluded to be a source of skeletal muscle plasticity.
Why patients attend emergency departments for conditions potentially appropriate for primary care: Reasons given by patients and clinicians differ
Authors: Masso Malcolm , Bezzina Andrew J , Siminski Peter , Middleton Rebekkah , Eagar Kathy
Published: June 2007

Objectives:  To compare reasons identified by clinical staff for potential primary care attendances to the ED with those previously identified by patients.

Methods:  Survey of staff and primary care patients in five ED in New South Wales, Australia using questionnaire based on reasons identified in published studies.

Results:  Clinicians in the survey identify a broader spectrum of reasons for potential primary care cases presenting to the ED than the patients themselves report. Doctors reported on average 4.1 very important reasons and nurses 4.8 compared with patients 2.4 very important reasons. The main reasons identified by both doctors and nurses were similar and quite different to those identified by patients. Clinicians were more likely to emphasize cost and access issues rather than acuity and complexity issues. There was no difference within the clinician group between doctors and nurses nor by varying levels of experience. Furthermore doctors with significant experience in both primary care and emergency medicine did not differ from the overall clinicians' pattern.

Conclusions:  These data confirm that clinician perspectives on reasons for potential primary care patients' use of ED differ quite markedly from the perspectives of patients themselves. Those differences do not necessarily represent a punitive or blaming philosophy but will stem from the very different paradigms from which the two protagonists approach the interactions, reflecting the standard tension in a provider – consumer relationship. If policy is to be developed to improve system use and access, it must take both perspectives into account with respect to redesign, expectations and education.
Treatment of extradural haemorrhage in Queensland: Interhospital transfer, preoperative delay and clinical outcome
Authors: Deverill Jo , Aitken Leanne M
Published: June 2007

Objectives:  To measure preoperative delays and clinical outcomes of patients with extradural haemorrhage, comparing patients presenting to hospitals with no neurosurgical facilities, with those presenting directly to neurosurgical centres.

Methods:  Retrospective case study with data collected from 10 centres. Patients were identified with a search of the Queensland Trauma Registry database. A total of 315 charts were reviewed, of patients presenting or referred to Queensland's public hospitals between 2002 and 2004 inclusive.

Results:  A total of 261 patients were included in the study. One hundred and fifty‐nine patients presented to hospitals with no neurosurgical facilities; 102 presented directly to neurosurgical centres. Forty‐six patients underwent interhospital transfer (IHT) before decompressive craniotomy; their median time interval from presentation to operation was 8 h 5 min. This delay was significantly greater than that for 25 patients admitted directly to neurosurgical centres (median 4 h 19 min; P = 0.0006). After excluding patients who had sustained hypoxic or hypotensive insults or serious extracranial injuries, all deaths (five) occurred in patients undergoing IHT before craniotomy.

Conclusions:  IHT of patients with extradural haemorrhage causes significant preoperative delay.
Evidence for a large fraction of Compton-thick quasars at high redshift
Authors: Martínez-Sansigre Alejo , Rawlings Steve , Bonfield David G. , Mateos Silvia , Simpson Chris , Watson Mike , Almaini Omar , Foucaud Sébastien , Sekiguchi Kazuhiro , Ueda Yoshihiro
Published: June 2007

Using mid-infrared and radio selection criteria, we pre-select a sample of candidate high-redshift type 2 quasars in the Subaru XMM–Newton Deep Field (SXDF). To filter out starburst contaminants, we use a Bayesian method to fit the spectral energy distributions (SEDs) between 24-μm and the B-band, obtain photometric redshifts, and identify the best candidates for high-z type 2 quasars. This leaves us with 12 zphot≥ 1.7 type 2 quasar candidates in an area ∼0.8 deg2, of which only two have secure X-ray detections. The two detected sources have estimated column densities NH∼ 2 & 3 × 1027 m−2, i.e. heavily obscured but Compton-thin quasars. Given the large bolometric luminosities and redshifts of the undetected objects, the lack of X-ray detections suggests extreme absorbing columns NH≳ 1028 m−2 are typical. We have found evidence for a population of ‘Compton-thick’ high-redshift type 2 quasars, at least comparable to, and probably larger than, the type 1 quasar population, although spectroscopic confirmation of their active galactic nuclei nature is important.
Variation of the Amati relation with cosmological redshift: a selection effect or an evolution effect?
Authors: Li Li-Xin
Published: June 2007

Because of the limit in the number of gamma-ray bursts (GRBs) with available redshifts and spectra, all current investigations on the correlation among GRB variables use burst samples with redshifts that span a very large range. Evolution and selection effects have thus been ignored, which might have an important influence on the results. In this Letter, we divide the 48 long-duration GRBs studied by Amati into four groups with redshift from low to high, each group containing 12 GRBs. Then we fit each group with the Amati relation log Eiso=a+b log Epeak, and check whether the parameters a and b evolve with the GRB redshift. We find that a and b vary with the mean redshift of the GRBs in each group systematically and significantly. Monte Carlo simulations show that there is only a ∼4 per cent chance that the variation is caused by the selection effect arising from the fluence limit. Hence our results may indicate that GRBs evolve strongly with cosmological redshift.
EFFECTS OF BITE SIZE ON THE SENSORY PROPERTIES OF VANILLA CUSTARD DESSERTS
Authors: PRINZ JON F. , DE WIJK RENE A.
Published: June 2007

A trained panel of 19 subjects were asked to rate a number of sensory attributes of commercially available vanilla custard desserts. Stimuli were placed in plastic cups and were sampled using 11‐mm‐diameter straws. In total, 304 samples were weighed before and after sampling and the volume ingested was calculated. The subjects were categorized into two groups on the basis of the mean volume ingested per sample (< and >10.6 mL). There were significant differences in the ratings between the two groups for temperature, creamy, astringent, melting and airy mouthfeels and rough and fatty after‐feel. We suggest that in sensory testing, it is important to either control or measure bite size to reduce intersubject variability. Manufacturers and caterers may also be able to modify the perception of their products by providing cues to the appropriate bite size by controlling the size of the spoon or container provided.
CONSUMER ACCEPTABILITY AND SHELF LIFE OF “FLOR DE INVIERNO” PEARS (Pyrus communis L.) UNDER DIFFERENT STORAGE CONDITIONS
Authors: SALVADOR ANA , VARELA PAULA , FISZMAN SUSANA M.
Published: June 2007

Two groups of “Flor de Invierno” pears (Pyrus communis L.), one recently harvested and another stored in a refrigerated controlled atmosphere for 7 months, were studied after storage at 20C in a normal atmosphere. Survival analysis was used to estimate sensory shelf life, which was 29 and 15 days for a 50% rejection probability, or 13 and 7 days for a 25% rejection probability for recently harvested and stored pears, respectively. A consumer panel evaluated the overall acceptability of the pears on a 9‐point hedonic scale. Recently harvested pears obtained higher acceptability scores throughout the 20C storage time. Instrumental firmness measurements were performed with a texture analyzer through a compression test. The results obtained showed that prolonged storage in a controlled atmosphere causes changes in the fruit that lead to lower firmness, lower acceptance scores and, consequently, a shorter sensory shelf life.

PRACTICAL APPLICATIONS

The use of survival analysis to study the shelf life of foods is quite a novel technique in which the key concept is to focus the shelf life estimation on consumer rejection. In this study, survival analysis was applied to pears, but can be applied to other fruits or foods. This approach is useful to know the adequate storage time of food without detrimental sensory quality changes that would conduct to the consumer rejection. Normally, loss in sensory quality appears before microbiological spoilage in many food, so this methodology could be used to predict sensory shelf life.
RELATING CONSUMER EVALUATION OF APPLE FRESHNESS TO SENSORY AND PHYSICO‐CHEMICAL MEASUREMENTS
Authors: PÉNEAU S. , BROCKHOFF P.B. , HOEHN E. , ESCHER F. , NUESSLI J.
Published: June 2007

The objective of the present investigation was to elucidate sensory attributes that influence consumer perception of apple freshness. A total of 4,758 consumers rated the freshness of six apple cultivars stored at different conditions. The apples were further characterized by consumer and panel sensory analyses as well as by physico‐chemical analyses. The contribution of these characteristics to freshness was tested with principal component regression. Texture properties were shown to be of main importance for freshness, and flavor attributes of less importance. It is hypothesized that the evaluation of freshness might be a measurement of apple aging through the evaluation of its texture. Consumers of different age and levels of apple consumption did not vary in their perception of freshness. However, differences by gender were observed. Attributes shown to influence freshness were in agreement when measured by consumer, panel and physico‐chemical analyses.

PRACTICAL APPLICATIONS

Freshness is an important characteristic of fruits and vegetables. A better understanding of what freshness means to consumers helps in the provision of high‐quality products perceived as fresh. A key finding of this study, which concentrates basically on the sensory aspects of freshness, is that freshness in case of apples is mainly related to high textural quality. Providing consumers with apples that meet their expectations of a fresh product might increase consumption.
Academic Performance of Young Children in Immigrant Families: The Significance of Race, Ethnicity, and National Origins
Authors: Glick Jennifer E. , Hohmann-Marriott Bryndl
Published: June 2007

Children of immigrants come from diverse backgrounds and enter school with different family migration experiences and resources. This paper addresses two basic questions: (1) to what extent does generation status exert an independent effect on early school performance net of race/panethnicity, language proficiency, and the family resources available to children as they enter formal schooling? and (2) to what extent do these broad conceptualizations of children in immigrant families mask variation by national origins? We take advantage of longitudinal data on a kindergarten cohort from the Early Childhood Longitudinal Study to examine children from diverse backgrounds. Considerable variation in academic performance persists across racial/panethnic groups as well as by country-of-origin background and linguistic ability even when adjusting for family background, resources, and previous academic performance. We find some intriguing evidence of early “segmentation” among children from various groups, suggesting some convergence within race and ethnicity for some children. However, this conclusion should not be overstated, because the results also point to the great diversity by national origins that are masked by reliance on racial/panethnic groupings.
An evaluation of the effectiveness of an educational and experiential intervention on nursing students’ attitudes towards older people
Authors: Ryan Assumpta , Melby Vidar , Mitchell Liz
Published: June 2007

Objectives.  This paper reports the results of a study that aimed to evaluate the effectiveness of an educational and experiential intervention on nursing students’ attitudes towards older people.

Background.  With repeated exposure to very sick older people in hospitals or nursing homes, nursing students are at risk of adopting stereotypical views about this section of the population as frail and dependent.

Design.  A pre‐ and post‐test design was used to conduct the study.

Methods.  Using Kogan's Attitudes Towards Old People Scale, the attitudes of nursing students were tested at the beginning of a degree programme in Adult Nursing (n = 130) and one year later (n = 94) following a series of visits to a well‐older person in the community.

Results.  Nursing students reported positive attitudes towards older people and these were retained throughout the first year of their nurse training. No statistically significant differences were found associated with any of the five independent variables in either pre‐ or postintervention students.

Conclusions.  The attitudes of nursing students towards older people remained positive. While it is possible that the experiential and educational interventions utilized in this study may have contributed to the retention of positive attitudes, further research is required to test this hypothesis.

Relevance to clinical practice.  Nurses have a major role to play in responding to the health and social care needs of older people and their families. The cultivation of positive attitudes is a key factor in enabling practising nurses to respond to this challenge.
Prevalence of falls with minor and major injuries and their associated factors among older adults in long‐term care facilities
Authors: Voyer Philippe , Verreault René , Mengue Pamphile , Azizah Ginette
Published: June 2007

Aims and objectives.  The objectives of this study were to determine the prevalence of falls with minor and major injuries and identify their risk factors.

Background.  Falls among residents of long‐term care facilities (LTCF) constitute a significant health issue.

Design.  This is a secondary analysis of a cross‐sectional study carried out among older people (n = 2332).

Methods.  This is a descriptive study focusing on the secondary analysis of a cross‐sectional study carried out with a group of older people (n = 2332) in 28 LTCF in Quebec City, Canada. Research assistants collected original data for each resident from two sources: structured simultaneous interviews with two nurses per unit from each of the homes and a review of the residents’ medical files.

Results.  7.2% of subjects had a fall leading to minor injuries and 10.1% a fall leading to major injuries. Risk factors associated with fall‐related minor injury are young age, male gender and cognitive impairment. Factors associated with fall‐related major injury were functional autonomy and length of stay. In further statistical analysis, controlling for functional autonomy, disruptive behaviours and neuroleptic use were found associated with fall‐related major injury.

Conclusions.  This study demonstrates that the factors associated with fall‐related minor injury are different from those associated with fall‐related major injury.

Relevance to clinical practice.  This study suggests that nurses working with LTCF residents who are concerned about the prevention of fall‐related major injury, may contribute to a reduction in such falls through optimal management of behavioural problems and neuroleptic use.
Has China Crowded out Foreign Direct Investment from Its Developing East Asian Neighbors?
Authors: Liu Ligang , Chow Kevin , Li Unias
Published: June 2007

This paper applies a gravity model to investigate the determinants of foreign direct investment (FDI) in East Asia. Economic fundamentals, such as market size, per capita income and country risk indicators, economic and cultural ties, exchange rate volatilities and information asymmetry are found to be important determinants for FDI. Globally, the inward FDI among high‐income OECD economies declined significantly on average over the period of 1990‐2003, whereas the inward FDI of the high‐income OECD economies in emerging market economies gained substantially. In the East Asian region, the ASEAN‐4 (Indonesia, Malaysia, the Philippines and Thailand) received above‐average inward FDI from the high‐income OECD economies after controlling for their economic fundamentals. By contrast, China's FDI from the high‐income OECD economies is below average relative to its economic fundamentals. Therefore, it is difficult to establish that China has crowded out FDI from its developing ASEAN neighbors.
Does China's Huge External Surplus Imply an Undervalued Renminbi?
Authors: Makin Anthony J.
Published: June 2007

A pegged exchange rate regime has been pivotal to China's export‐led development strategy. However, its huge trade surpluses and massive build up of international reserves have been matched by large deficits for major trading partners, creating acute policy concerns abroad, especially in the USA. This paper provides a straightforward conceptual framework for interpreting the effect of China's exchange rate policy on its own trade balance and that of trading partners in the context of discrepant economic growth rates. It shows how pegging the exchange rate when output is outstripping expenditure induces China's trade surpluses and counterpart deficits for its trading partners. An important corollary is that given its strictly regulated capital account, China's persistently large surpluses imply a significantly undervalued renminbi, which should gradually become more flexible.
Detection and Molecular Characterization of Calf Diarrhoea Bovine Coronaviruses Circulating in South Korea during 2004–2005
Authors: Park S. J. , Lim G. K. , Park S. I. , Kim H. H. , Koh H. B. , Cho K. O.
Published: June 2007

Although the widespread occurrence of calf diarrhoea (CD) bovine coronavirus (BCoV) infections have been reported in most cattle producing countries, only the genetic differences in the BCoVs from American and Canadian isolates and/or strains have been identified and compared. Hence, it is unclear if the BCoVs circulating in the other countries have distinct genetic characteristics. The aim of this study was to determine the prevalence and genetic diversity of CD BCoVs based on the deduced amino acid (aa) sequences of the spike (S) and haemagglutinin/esterase (HE) proteins in South Korea. RT‐PCR and nested PCR using the primer pairs specific to the nucleocapsid gene, BCoVs detected the BCoVs in 56 (15.6%) of 359 diarrhoeic faecal samples. Phylogenetic analysis of the entire S gene indicated that 10 Korean CD BCoV strains clustered with other Korean BCoV strains with different clinical forms but were different from the American and Canadian BCoV strains. Moreover, the phylogenetic data of the aa sequences of the HE gene revealed all the Korean CD strains to be distinct from the other Korean BCoV strains with different clinical forms. These results suggest that the Korean BCoVs cause endemic infections in diarrhoeic calves in Jeonnam province and have taken a different evolutionary pathway from the BCoVs in other countries. Moreover, the different BCoV strains are circulating in the different clinical forms in South Korea. These results also suggest that vaccines against the BCoVs can be developed with each Korean BCoV in different clinical forms.
A Dynamic Sensing-and-Modeling Approach to Three-Dimensional Point- and Area-Sensor Integration
Authors: Huang Yunbao , Qian Xiaoping
Published: June 2007

The recent advancement of 3D non-contact laser scanners enables fast measurement of parts by generating a huge amount of coordinate data for a large surface area in a short time. In contrast, traditional tactile probes in the coordinate measurement machines can generate more accurate coordinate data points at a much slower pace. Therefore, the combination of laser scanners and touch probes can potentially lead to more accurate, faster, and denser measurements. In this paper, we develop a dynamic sensing-and-modeling approach for integrating a tactile point sensor and an area laser scanner to improve the measurement speed and quality. A part is first laser scanned to capture its overall shape. It is then probed via a tactile sensor where the probing positions are dynamically determined to reduce the measurement uncertainty based on a novel next-best-point formulation. Technically, we use the Kalman filter to fuse laser-scanned point cloud and tactile points and to incrementally update the surface model based on the dynamically probed points. We solve the next-best-point problem by transforming the B-spline surface’s uncertainty distribution into a higher dimensional uncertainty surface so that the convex hull property of the B-spline surface can be utilized to dramatically reduce the search speed and to guarantee the optimality of the resulting point. Three examples in this paper demonstrate that the dynamic sensing-and-modeling effectively integrates the area laser scanner and the point touch probe and leads to a significant amount of measurement time saving (at least several times faster in all three cases). This dynamic approach’s further benefits include reducing surface uncertainty due to the maximum uncertainty control through the next-best-point sensing and improving surface accuracy in surface reconstruction through the use of Kalman filter to account various sensor noise.
Finite Element Simulation of Magnesium Extrusion to Manufacture a Cross-Shaped Profile
Authors: Liu Gang , Zhou Jie , Duszczyk Jurek
Published: June 2007

At present, a fundamental knowledge of the thermal and mechanical interactions occurring during the extrusion of magnesium is lacking. This acts as a serious technological barrier to the cost-effective manufacturing of lightweight magnesium alloy profiles. In the present research, a three-dimensional finite element (FE) simulation of extrusion to produce a magnesium alloy profile with a cross shape was carried out as an efficient means to gain this understanding. It revealed the redistribution of temperatures in the billet throughout the process from the transient state to the steady state, the formation of the deformation zone and dead metal zone, and varying fields of effective stress, effective strain, effective strain rate, and temperature close to the die orifice. The predicted extrudate temperature and extrusion pressure were compared with experimental measurements. The key to controlling the extrudate temperature and extrusion process was found to lie in the capabilities of predicting the temperature evolution during transient extrusion, as affected by extrusion conditions. The relationship between ram speed and the extrudate temperature increase from the initial billet temperature was established and experimentally validated.
Virtual Clay: An Enhanced Marching Cubes Algorithm for In-Process Geometry Modeling
Authors: Chiou John C. J.
Published: June 2007

This paper presents an enhanced marching cubes algorithm to construct an iso-boundary for in-process geometric modeling for material removal processes. The author first analyzes the tool motion and the geometric properties in material removal processes. The result shows that the in-process geometry is the complement of the tool swept volume from the raw material. The in-process geometry can be determined by continuously updating itself from the swept volume of the tool. This study uses a three-dimensional G-buffer to update the intersection information between the tool swept volume and the in-process geometry. Rather than traditionally searching for all intersection points ranging in a cube, the developed algorithm uses certain specific intersection points that are selected based on the removal geometry properties to construct the iso-boundary. It avoids the unfavorable ambiguities and holes on constructed boundaries. In addition, the developed algorithm is able to handle multiple intersection points in a cubical edge. This study also discusses material removal volume and tool collision issues. The computer implementation shows that the developed method is superior to the traditional ones in material removal applications.
Experimental Model of Temperature-Driven Nanofluid
Authors: Nnanna A. G. Agwu
Published: June 2007

This paper presents a systematic experimental method of studying the heat transfer behavior of buoyancy-driven nanofluids. The presence of nanoparticles in buoyancy-driven flows affects the thermophysical properties of the fluid and consequently alters the rate of heat transfer. The focus of this paper is to estimate the range of volume fractions that results in maximum thermal enhancement and the impact of volume fraction on Nusselt number. The test cell for the nanofluid is a two-dimensional rectangular enclosure with differentially heated vertical walls and adiabatic horizontal walls filled with 27 nm Al2O3–H2O nanofluid. Simulations were performed to measure the transient and steady-state thermal response of nanofluid to imposed isothermal condition. The volume fraction is varied between 0% and 8%. It is observed that the trend of the temporal and spatial evolution of temperature profile for the nanofluid mimics that of the carrier fluid. Hence, the behaviors of both fluids are similar. Results shows that for small volume fraction, 0.2⩽ϕ⩽2% the presence of the nanoparticles does not impede the free convective heat transfer, rather it augments the rate of heat transfer. However, for large volume fraction ϕ>2%, the convective heat transfer coefficient declines due to reduction in the Rayleigh number caused by increase in kinematic viscosity. Also, an empirical correlation for Nuϕ as a function of ϕ and Ra has been developed, and it is observed that the nanoparticle enhances heat transfer rate even at a small volume fraction.
Thermal Diffusivity Estimation in a Picosecond Photoreflectance Experiment
Authors: Battaglia Jean-Luc , Kusiak Andrzej , Batsale Jean-Christophe
Published: June 2007

The aim of this work is to provide an analytical expression for the thermal diffusivity of a material in the configuration of the picosecond photoreflectance experiment. It is shown that the thermal diffusivity can be estimated from the absorption depth of the pump beam together with the probe beam as well as the time when the two asymptotic behaviors of the impulse response cross. Thereby, it is not required to measure absolute values of incident heat flux and average temperature on the aiming area.
Numerical Investigation of the Thermally Developing Flow in a Curved Elliptic Duct With Internal Fins
Authors: Papadopoulos P. K. , Hatzikonstantinou P. M.
Published: June 2007

The hydrodynamically fully developed and thermally developing flow inside a curved elliptic duct with internal longitudinal fins is studied numerically. The duct is subjected to the uniform temperature boundary condition on its wall and fins. The local and mean Nusselt numbers are examined for various values of the Dean and Prandtl numbers, the cross-sectional aspect ratio, and the fin height. The characteristics of the optimum duct, which achieves enhanced heat transfer rates combined with low friction losses, are determined in terms of the aspect ratio and the fin height.
Listeria monocytogenesSurface Proteins: from Genome Predictions to Function
Authors: Bierne Hélène , Cossart Pascale
Published: June 2007

The genome of the human food-borne pathogenListeria monocytogenesis predicted to encode a high number of surface proteins. This abundance likely reflects the ability of this bacterium to survive in diverse environments, including soil, food, and the human host. This review focuses on the various mechanisms by which listerial proteins are attached at the bacterial surface and their many functions, including peptidoglycan metabolism, protein processing, adhesion to host cells, and invasion of host tissues. Extensivein silicoanalysis of the domains or motifs present in these mosaic proteins reveals that diverse structural features allow the surface proteome to interact with diverse bacterial or host components. This diversity offers new clues about the molecular bases ofListeriapathogenesis.
Sponge-Associated Microorganisms: Evolution, Ecology, and Biotechnological Potential
Authors: Taylor Michael W. , Radax Regina , Steger Doris , Wagner Michael
Published: June 2007

Marine sponges often contain diverse and abundant microbial communities, including bacteria, archaea, microalgae, and fungi. In some cases, these microbial associates comprise as much as 40% of the sponge volume and can contribute significantly to host metabolism (e.g., via photosynthesis or nitrogen fixation). We review in detail the diversity of microbes associated with sponges, including extensive 16S rRNA-based phylogenetic analyses which support the previously suggested existence of a sponge-specific microbiota. These analyses provide a suitable vantage point from which to consider the potential evolutionary and ecological ramifications of these widespread, sponge-specific microorganisms. Subsequently, we examine the ecology of sponge-microbe associations, including the establishment and maintenance of these sometimes intimate partnerships, the varied nature of the interactions (ranging from mutualism to host-pathogen relationships), and the broad-scale patterns of symbiont distribution. The ecological and evolutionary importance of sponge-microbe associations is mirrored by their enormous biotechnological potential: marine sponges are among the animal kingdom's most prolific producers of bioactive metabolites, and in at least some cases, the compounds are of microbial rather than sponge origin. We review the status of this important field, outlining the various approaches (e.g., cultivation, cell separation, and metagenomics) which have been employed to access the chemical wealth of sponge-microbe associations.
ALFVEN MODES DRIVEN NONLINEARLY BY METRIC PERTURBATIONS IN ANISOTROPIC MAGNETIZED COSMOLOGIES
Authors: KUIROUKIDIS APOSTOLOS , KLEIDIS KOSTAS , PAPADOPOULOS DEMETRIOS B.
Published: June 2007

We consider anisotropic magnetized cosmologies filled with conductive plasma fluid and study the implications of metric perturbations that propagate parallel to the ambient magnetic field. It is known that in the first-order (linear) approximation with respect to the amplitude of the perturbations no electric field and density perturbations arise. However when we consider the nonlinear coupling of the metric perturbations with their temporal derivatives, certain classes of solutions can induce steeply increasing in time, electric field perturbations. This is verified both numerically and analytically. The source of these perturbations can be either high-frequency quantum vacuum fluctuations, driven by the cosmological pump field, in the early stages of the evolution of the Universe, or astrophysical processes, or a nonlinear isotropization process, of an initially anisotropic cosmological space–time.
IONIC BINDING IN A SUSY BACKGROUND
Authors: CLAVELLI L. , LOVORN T.
Published: June 2007

From string theory and the observation of a positive vacuum energy in our universe it seems inevitable that there will eventually be a phase transition to an exactly supersymmetric (susy) universe. In this phase there will be an effective weakening of the Pauli principle due to Fermi–Bose degeneracy. As a consequence molecular binding will be significantly affected. We make some general comments on susy molecules and perform a variational principle estimate of ionic binding energies.