bluuebunny/crossref_metadata_2025 huggingface dataset:
MEASURING THE PERFORMANCE OF A COMMUNIST COMMAND ECONOMY: AN ASSESSMENT OF THE CIA ESTIMATES FOR THE U.S.S.R.
Authors: Maddison Angus
Published: March 2005

There are major methodological and practical problems in comparing the performance of capitalist and communist economies. They have been most carefully analysed for the former Soviet Union, for which there was a huge research input, mainly by the CIA. The CIA effort had considerable merit, particularly in assessing Soviet rates of growth. Unfortunately, it was terminated in 1991, partly because it suffered from unduly harsh criticism, partly because its political relevance waned. However, the CIA archives remain an important source for the study of comparative economic growth. It would be extremely useful if they were opened to scholars, a serious loss if they were destroyed.
THE STOCK OF CONSUMER DURABLES IN THE UNITED KINGDOM: NEW ESTIMATES 1948–95
Authors: Williams Geoffrey
Published: March 2005

A modified version of the perpetual inventory model is applied to new data on consumers' expenditure in the United Kingdom to establish estimates of that part of personal sector wealth represented by the stock of consumer durables. Current and constant price estimates are provided at an aggregate and disaggregate level for the gross and net stock and for the imputed consumption income over the period 1948–95. The accuracy and consistency of the estimates are evaluated in the context of other approaches.
ATKINSON AND BOURGUIGNON'S DOMINANCE CRITERIA: EXTENDED AND APPLIED TO THE MEASUREMENT OF POVERTY IN FRANCE
Authors: Chambaz Christine , Maurin Eric
Published: March 2005

We demonstrate that the criteria put forward by Atkinson and Bourguignon (1987) can be satisfactorily applied to the analysis of poverty even when the demographic composition of society and the definition of poverty change over time. We show that they provide both sufficient and necessary conditions for any robust conclusions concerning the changes in welfare and poverty. We apply these criteria to a set of data tracking annual income distribution movements in France from 1977 to 1994. The Atkinson and Bourguignon criteria posit that recent changes in poverty are a function of macroeconomic fluctuations in activity.
HOW CERTAIN ARE DUTCH HOUSEHOLDS ABOUT FUTURE INCOME? AN EMPIRICAL ANALYSIS
Authors: Das Marcel , Donkers Bas
Published: March 2005

The precautionary saving literature shows that income uncertainty increases savings and wealth. To estimate the magnitude of this effect, we need a measure of income uncertainty. This paper empirically analyzes subjective income uncertainty in The Netherlands. Data come from a large Dutch household survey. We measure income uncertainty by asking questions on expected household income in the next twelve months. First, we describe the data and investigate the relationship between the measure of income uncertainty and a number of household characteristics. Controlling for information on expected income changes, we find strong relationships between labor‐market characteristics and the subjective income uncertainty as reported by the heads of the households. Second, we compare income uncertainty in The Netherlands with income uncertainty in the U.S. and Italy. It becomes evident that perceived income uncertainty is smaller in The Netherlands than it is in the U.S.
INCOME INEQUALITY IN GERMANY DURING THE 1980s AND 1990s
Authors: Biewen Martin
Published: March 2005

The paper estimates a variety of inequality measures for three sub‐samples of the German population using cross‐sectional data on equivalent income from the German Socio‐Economic Panel (GSOEP). The sub‐populations under consideration are residents of West Germany including foreigners for the years 1984 to 1996, residents of East Germany for the years 1990 to 1996 and a comprehensive German population for the years 1990 to 1996. Bootstrap methods are applied to test whether changes in inequality are statistically significant. In order to account for panel attrition and over‐sampling, sample weights are incorporated into the estimation procedure. The empirical results confirm the relative stability of the West German income distribution. While income inequality in West Germany has generally not altered in an economically relevant way over the period 1985 to 1996, inequality in East Germany has increased after reunification. Despite this increase, inequality remains substantially higher in the western part of the country. Convergence of eastern mean income to the western level generally overcompensated the rise in inequality in East Germany, so that the level of inequality in unified Germany is lower in 1996 than in 1990.
Variables Affecting Silicone‐Polymethyl Methacrylate Interfacial Bond Strengths
Authors: Wood William E. , Johnson Dean L. , Duncanson Manville G.
Published: March 2005

Purpose This study investigated the effects of various polymerization methods and of various types of silane coupling agents on the intefacial bond strengths of Molloplast‐B and of two types of heat‐processed polymethyl methacrylate (PMMA).

Materials and Methods Standardized blocks of PMMA were processed and stored in 100% humidity for 14 days. Silicone of equal dimensions was flasked and processed with premixed and fresh‐mixed silane coupling agents interposed. Processing utilized both a typical heated‐water system and a dry‐heat oven. Following recovery, the specimens were peel‐tested at an angle of 180° in an Instron machine.

Results There was no significant difference between the test variables of Lucitone (Dentsply/York Division, York, PA) versus Lucitone 199 (Dentsply/York Division), nor with wet versus dry heat polymerization methods. However, the mean bond strengths for premixed silane improved slightly in a wet polymerization environement. Conversely, fresh‐mixed silane's mean bond strength increased slightly with dry‐heat polymerization.

Conclusions The bond strength between a methyl methacrylate denture base and a silicone soft liner varies only slightly when either Lucitone, Lucitone 199, or polymerization in a wet or dry environement is used. Under the conditions of this study, a fresh‐mixed silane coupling agent produced a distinctly superior bond strength.
The Effect of Selective Die Spacer Placement Techniques on the Seatability of Castings
Authors: Hager Tam S. , Gardner F. Michael , Edge Marion J.
Published: March 2005

It has been reported in the literature that impingement of the casting at the axial‐occlusal line angle of the tooth preparation may be a major cause of incomplete seating following cementation. It has been suggested that an additional coat of spacer applied to these areas on the laboratory die before the fabrication of the casting may alleviate this discrepancy. This study evaluated the effect of three die spacer placement techniques on the seatability of cemented castings. Results showed no statistical difference in seating between castings made with conventional relief and those made with additional relief at the axial‐occlusal line angles. Castings relieved exclusively at the axial‐occlusal line angles exhibited significant post‐cementation marginal openings.
Alternative Barrier Technique
Authors: Bisang Barbara G. , Engelmeier Robert L.
Published: March 2005

This article offers an alternative barrier technique that not only places the barrier in the dental treatment room, but also places it under the direct supervision and control of the dentist. A known hepatitis B carrier was selected for immediate denture treatment to illustrate and test this proposed barrier technique.
A One‐Appointment Mouthstick Appliance
Authors: Duncan J. David , Puckett Aaron D.
Published: March 2005

Quadriplegics rely on mouthstick appliances to perform a variety of tasks to establish more self‐sufficiency. Present techniques to fabricate a quality mouthstick appliance requires professional expertise, time, and laboratory expense. A technique for providing an inexpensive, durable mouthstick appliance in one appointment is described.
First‐Stage Fixed Provisional Restorations for Implant Prosthodontics
Authors: Zinner Ira D. , Panno Francis V. , Pines Mitchell S. , Small Stanley A.
Published: March 2005

Combination metal‐and‐acrylic‐resin fixed provisional prostheses can be used in implant dentistry as an alternative to a removable provisional prosthesis. They may be fabricated in the laboratory and inserted on the day of fixture placement to ensure that the patients may return to their normal lifestyles with minimal discomfort or interruption in function and esthetics. These interim restorations may be used in free‐standing as well as hybrid types of implant supported prostheses. The materials used and techniques of fabrication are described.
Fabrication of a Fixed Partial Denture in the Class II Partial Edentulous Mandible Using the UCLA Abutment: A Clinical Report
Authors: Dominici John T.
Published: March 2005

Several methods are currently available to restore the partially edentulous patient with osseointegrated implants. The UCLA abutment eliminates the unesthetic, traditional transmucosal abutment and can provide esthetic crowns, fixed prostheses, and subgingival porcelain margins without the need for excessive instrumentation and components. A clinical report for the fabrication of a direct, implant‐borne fixed prosthesis using the UCLA abutment is presented.
Gypsum Compatibility of Antimicrobial Alginates After Spray Disinfection
Authors: King Barbara B. , Norling Barry K. , Seals Richard
Published: March 2005

Purpose

This investigation examined the gypsum compatibility of two antimicrobial alginates after spray disinfection. Subjective compatibility evaluations were compared with objective quantitative profilometer readings of gypsum cast surface roughness.

Materials and Methods

COE Hydrophilic Gel Alginate, Jeltrate Plus Antimicrobial Alginate, and their nonantimicrobial counterparts, Coe Alginate and Jeltrate Plus, were used in this study. After spray disinfection with water (control), Alcide LD, Biocide, OMC II, and 0.5% NaOCl, impressions of the American National Standards Institute/American Dental Association (ANSI/ADA) specification no. 18 detail reproduction die and impressions made simultaneously of a smooth glass die were cast in Microstone, Silky‐Rock, and Die‐Keen. Five specimens were made for each alginate/disinfectant/gypsum combination for a total of 300 samples each for both the subjective and objective analyses. For the subjective analysis of gypsum compatibility, the specimens made from the ANSI/ADA specification no. 18 test die were evaluated by using a 1‐to‐4 visual rating system at magnification × 12. For the objective analysis, the arithmetic average surface roughness of each specimen made from the smooth glass die was recorded three times with a 200‐mg skidless stylus instrument.

Results

The results of the ANSI/ADA specification no. 18 testing for gypsum compatibility showed that 11 of 60 possible combinations did not pass the test. All impressions made with nonantimicrobial COE Alginate passed the test regardless of the disinfectant/gypsum combination. The results of the three‐factor analysis of variance for the subjective and objective analyses showed significant interactions between alginates, disinfectants, and stones at the P < .05 level. To further delineate these differences, unpaired t tests (P < .05) within brands for each disinfectant/gypsum combination were performed.

Conclusions

The addition of 1% chlorhexidine diacetate to COE Hydrophilic Gel Alginate has decreased its compatibility with the dental stones and disinfectants tested when compared with its nonantimicrobial counterpart. In terms of gypsum compatibility, the nonantimicrobial COE Alginate was compatible with all disinfectant and gypsum combinations tested. The addition of 1.70% didecyldimethyl ammonium chloride to Jeltrate Plus Antimicrobial Alginate has increased its compatibility with all the dental stones tested. A strong positive correlation (r= 0.7398) was found between visual gypsum compatibility evaluation scores and surface roughness of gypsum casts.
The Prosthodontic Management of Endodontically Treated Teeth: A Literature Review. Part I. Success and Failure Data, Treatment Concepts
Authors: Goodacre Charles J. , Spolnik Kenneth J.
Published: March 2005

Part I of this three‐part literature review discusses the incidence of endodontic treatment required after prosthodontic procedures, whether crowns are needed on endodontically treated teeth, the primary purpose of posts, the causes of post and core failure, root fracture incidence data, and post design considerations. Pertinent questions are addressed based on the past 25 years of dental literature.
An In Vivo Evaluation of Adhesives Used in Extraoral Maxillofacial Prostheses
Authors: Haug Steven P. , Richard Glenn E. , Margiotti Eugene , Winkler Mark M. , Moore Dorsey J.
Published: March 2005

Purpose This investigation introduces percent adherent area and 10‐minute and 8‐hour peelstrength values as an in vivo evaluation of three popular maxillofacial prosthetic adhesives when used with three extraoral prosthetic polymers.

Materials and Methods Specimens of Silastic MDX 4‐4210, Silastic Medical Ahesive A (Dow Corning Corporation, Midland, MI), and Silicone A‐2186 (Factor II, Inc, Lakeside, AZ) were adhered to 25 subjects' arms using Secure Medical Adhesive (Factor II, Inc), Pros‐Aide Adhesive (ADM Tronics Inc, Northvale, NJ), and Hollister Colostomy Adhesive (Hollister Inc, Libertyville, IL). After 10 minutes, the peel strength required to remove the specimens was measured. Additional specimens were then adhered to the subjects and worn for 8 hours. The nonadherent areas of the specimens were then marked, the peel strength was measured again, and then the percent adherent area was calculated.

Results Hollister Colostomy Adhesive showed greater 10‐minute peel‐strength values when used with Silastic Medical Adhesive A. The peel‐strength values of the Hollister Colostomy Adhesive when used with Silastic MDX 4‐4210 increased with time. The greatest percent adherent area was obtained with Silastic MDX 4‐4210 using Pros‐Aide Adhesive, and the lowest was obtained with Pros‐Aide Adhesive using Silicone A‐2186 and Silastic Medical Adhesive A.

Conclusions There was no clearly superior adhesive/prosthetic material combination based on the tests used in this study; however, individual skin variations between patients affect the adhesive properties.
A Retrospective Clinical Study of Resin‐Bonded Cingulum Rest Seats
Authors: Janus Charles E. , Unger John W. , Crabtree Donald G. , McCasland John P.
Published: March 2005

Purpose

The purpose of this study was to evaluate the success of the resin‐bonded cingulum rest seats (RBCRS) supporting removable partial dentures.

Materials and Methods

Twenty‐six patients who had been treated with RBCRSs were recalled and examined.

Results

None of the patients who had RBCRSs placed on their teeth experienced debonding, and none of the teeth showed clinically significant signs of wear to the rest seats.

Conclusions

The use of RBCRSs to support removable partial dentures is a highly successful method of treatment.
Multiple Implants for First Molar Prosthodontics
Authors: Zinner Ira D. , Small Stanley A. , Jansen Curtis E. , Panno Francis V.
Published: March 2005

Problems that can occur when single implants are utilized to restore first molar teeth include the frequent loosening of screws, as well as screws and/or implant breakage. These may result from torquing and rotational movements of the prosthesis during masticatory and parafunctional mandibular movements. When sufficient bone and mesio‐distal restorative space is present, the placement of two implants should be considered.
Esthetics: Patients' Perceptions of Dental Attractiveness
Authors: Dunn William J. , Murchison David F. , Broome James C.
Published: March 2005

Purpose

The importance of dentofacial attractiveness to the psychosocial well‐being of an individual has been well established. Very little information is available regarding dental patient perceptions of a pleasing esthetic image. The purpose of this study was to identify factors distinctive to attractive smiles versus unattractive smiles, as perceived by patients.

Materials and Methods

Standardized format photographs (5 × 7 in, matte finish, at f‐32 and 1:2 magnification) of eight male and eight female smiles, framing only lips and teeth, were viewed by 297 subjects. The smiles exhibited differences in symmetry, tooth shade, number of teeth displayed, and height of maxillary lip line, and included both restored and unrestored teeth. Respondents ranked the photographs in order from most to least appealing appearance. Respondents viewed each series of photographs in a similar lighting and time period. A questionnaire identified the respondent's age, sex, race, education, income, and home town. Twenty‐five demographic groups were established from the information in the questionnaire. Data were analyzed using stepwise discriminant analysis to determine the combination of smile characteristics that best predicted the ranking.

Results

The same female smile was chosen as the most attractive by 24 of the 25 demographic groups. This smile is characterized by natural teeth having light shade, high lip line, a large display of teeth, and radiating symmetry. Two female smiles typified by darker shade and asymmetry were rated by all groups as being least attractive. Two male smiles were judged equal as the most pleasing esthetically. Respondents favored those smiles characterized by light shade, a moderate display of teeth, moderate lip line, and a symmetrical arrangement of teeth. One male smile characterized by darker shade was rated as least attractive.

Conclusions

In all cases, tooth shade was the most important factor, followed in sequence by unrestored natural teeth and number of teeth displayed. No correlation was found to exist between specific demographic groups and smile variables.
The Accuracy of Implant Verification Casts Compared With Casts Produced From A Rigid Transfer Coping Technique
Authors: Carr Alan B. , Master Jiten
Published: March 2005

Purpose Prosthodontic techniques for implant‐supported prostheses continue to evolve in an effort to facilitate treatment and minimize costs. Because research has shown no impression transfer technique to be without error, some clinicians have attempted to control the fit of prosthetic frameworks by reorienting sections of patterns or frameworks intraorally, fabricating a verification cast, and completing the prosthesis to fit such a cast. One manufacturer has attempted to meet both impression‐making and verification‐cast objectives by providing metallic impression copings (MICS) with extensions that allow contact between the copings for rigid fixation with acrylic resin before impression making. The purpose of this study was to determine the accuracy of casts produced from the MICS transfer process compared with casts produced from sectioned frameworks, where both techniques used a low‐polymerization‐shrinkage acrylic resin polymer to rigidly join the sections.

Materials and Methods Using stainless steel measurement spheres as a reference point on each implant analog, the distances between analogs on the experimental casts were compared with the distances measured on the master cast. Seven casts were produced for each group and measured with a machinist's microscope at a 4‐μm level of precision.

Results The results revealed that the MICS transfer exhibited a mean error of 41 μm, which was significantly less than the verification‐cast group mean error of 57 μm (p < .01, Student's t test).

Conclusions Given these results, clinicians can consider the rigid transfer technique as provided in the MICS transfer to be more accurate than the verification technique as outlined in this study.
Finite Element Stress Analysis of IMZ Abutment Designs: Development of a Model
Authors: Holmes David C. , Haganman Chris R. , Aquilino Steven A. , Diaz‐Arnold Ana M. , Stanford Clark M.
Published: March 2005

PurposeThis article describes the development of a model system for use in finite element stress analysis of three different IMZ abutment designs: original threaded Intra‐Mobile Element (IME), Abutment Complete (ABC), and Intra‐Mobile Connector (IMC).

Materials and MethodsA three‐dimensional model simulating a cast gold crown restoration attached to an osseointegrated IMZ implant fixture was generated for each abutment design. Each model was discretized into axisymmetric finite elements representing the crown, the various implant system components, and supporting structures. A convergence test was performed to optimize the mesh. Convergence test mesh refinement for the IME, the IMC, and the ABC abutment models resulted in 818 elements, 2,566 nodes; 738 elements, 2,362 nodes; and 663 elements, 2,051 nodes, respectively. Progressive tightening of the retaining screw (preload) was simulated; the degree of screw tightening necessary to prevent opening of the crown‐abutment interface in extreme loading (500‐N occlusal load at 45°) was determined individually for each system.

ConclusionsModels of three IMZ abutment designs have been refined and the appropriate relative screw preloads determined. This model system is to be used subsequently in stress analysis comparison for the three systems.
Deflection and Stress Distribution in Three Different IMZ Abutment Designs
Authors: Haganman Chris R. , Holmes David C. , Aquilino Steven A. , Diaz‐Arnold Ana M. , Stanford Clark M.
Published: March 2005

Purpose The purpose of this study was to compare the stress distribution in the resin element and the retaining screw for three different IMZ prosthetic systems: 1) original threaded Intra‐Mobile Element (IME); 2) Abutment Complete (ABC); and 3) Intra‐Mobile Connector (IMC). This stress distribution comparison was then related to variations in deflection of the prosthetic superstructure.

Materials and Methods Employing the finite element method, a three‐dimensional model simulating a cast gold restoration attached to an osseointegrated IMZ implant fixture was generated for each system. The representation of the implant fixture, the supporting structures, and the external contours of the crown were identical in the three models, while the configuration of the abutment varied to characterize the individual systems. Each model was discretized into axisymmetric finite elements representing the crown, the various implant system components, and supporting structures. A series of harmonic functions was written to define non‐axisymmetric loads of 100 N and 500 N evenly distributed over the entire occlusal surface of the crown. Each load was applied individually to the models, first in a vertical direction, and then at a 45° angle to the median plane. Predicted deflection and stress distributions were computed and plotted for each loading condition of each model.

Results Deflections measured at the buccal cusp tip ranged from 0.002 mm (100‐N load applied vertically to the ABC model) to 0.802 mm (500‐N load applied at 45° to the IME model). Maximum effective stresses in the retaining screw ranged from 129 MPa (100‐N load applied vertically to the ABC model) to 1,315 MPa (500‐N load applied at 45°C to the IMC model). A correlation was observed between the peak stresses in the screw and the deflection of the superstructure.

Conclusions Deflections and stress concentrations with the IMC were predicted to be in the same range as with the IME, but much greater than with the ABC.
An Effective Technique for Denture Border Evaluation
Authors: Phoenix Rodney D. , DeFreest Charles F.
Published: March 2005

Proper extension and adjustment of denture borders is a critical component in successful removable prosthodontic treatment. Unfortunately, commonly marketed disclosing media may not provide appropriate viscosities for the accurate assessment of denture border extensions. This article provides a technique for the mixing, unit‐dose packaging, and utilization of a disclosing medium that is extremely well‐suited for denture border applications. The technique employs commonly available materials and complies with current “unit‐dose” guidelines.
Immediate Maxillofacial Prosthodontic Rehabilitation After Radical Mid‐Face Tumor Resection
Authors: Cheng Ansgar C. , Morrison David , Wee Alvin G.
Published: March 2005

Mid‐facial surgical defects can adversely affect a patient's esthetics and psychological wellbeing. Fabrication of a definitive mid‐facial prosthesis can be a time‐consuming procedure. It is crucial to minimize the time between the tumor resection and initial prosthetic rehabilitation. This article describes a method for rapid fabrication of a transitional facial prosthesis for mid‐facial defects.
An Alternative to Splinting Multiple Implants: Use of the ITI System
Authors: Solnit Gary S. , Schneider Robert L.
Published: March 2005

The restoration of patients with dental implants presents many challenges. Some of the common concerns and problems are difficulty in achieving a passive‐fitting cast framework and loosening of prosthesis‐retaining screws or abutment screws when using external hex prosthesis connection systems. The ITI system uses a unique connection of the abutment to the prosthesis‐anchoring component. Because of this unique connection, many problems encountered with external hex designs have been greatly reduced or eliminated by the ability to more easily restore individual teeth with individual implants. This article will present the rationale for restoration of a patient with implants using individual implant‐supported restorations.
Retrievable Cemented Implant Restorations
Authors: Chee Winston W.L. , Torbati Arman , Albouy Jean Pierre
Published: March 2005

Prostheses can be attached to implants or implant abutments by screw retention, cementation, or with the use of set‐screws. The indications for non‐screw‐retained restorations are discussed with respect to implant body position and surgical limitations for implant placement. The advantages and disadvantages of each method are outlined. A technique that uses a screw threaded into the implant restoration to displace the cemented restoration is presented. Use of this technique will allow predictable removal of the cemented restorations without damage to the prosthesis or abutment.
Occlusal Rehabilitation Using Implants for Orthodontic Anchorage
Authors: Schneider Galen , Simmons Kirt , Nason Ron , Felton David
Published: March 2005

Osseointegration is defined as a direct interaction of bone to an implant surface. As a result, the implant fixture is immobilized in the bone and lends itself to function as an anchor for orthodontic tooth movements. When properly treatment‐planned, these implants can also be used as prosthodontic abutments for single crowns, or removable or fixed partial dentures. This article describes how implant fixtures were surgically placed within the maxillary and mandibular arches of a partially edentulous patient, and used for orthodontic anchorage to reposition the remaining teeth into a more favorable arch position, creating increased posterior interocclusal space. The fixtures were then restored with fixed partial dentures to rehabilitate the patient into a mutually protected occlusion.
Dental Implant Materials: Commercially Pure Titanium and Titanium Alloys
Authors: McCracken Michael
Published: March 2005

Manufacturers use six different titanium‐based biomaterials to fabricate dental implants. Each of these materials, including four grades of commercially pure titanium and two titanium alloys, has distinct mechanical and physical properties. Clinicians should recognize these differences for optimal treatment planning and patient care.
Molecular cloning and in vitro evaluation of an infectious simian‐human immunodeficiency virus containing env of a primary Chinese HIV‐1 subtype C isolate
Authors: Wu YingYun , Hong KunXue , Chenine Agnès‐Laurence , Whitney James B. , Chen QiMin , Geng YunQi , Ruprecht Ruth M. , Shao YiMing
Published: March 2005

Abstract:  Human immunodeficiency virus (HIV) clade C is the most prevalent subtype and accounts for approximately 50% of all HIV infections worldwide. In China, the prevalent HIV strains are B′/C subtypes, in which the envelope belongs to subtype C. To evaluate potential AIDS vaccines targeting Chinese viral strains in non‐human primate models, we constructed an infectious simian‐human immunodeficiency virus (SHIV) that expresses most of the envelope of a primary HIV strain, which was isolated from a HIV‐positive intravenous drug user from XinJiang province in China. The resulting chimeric SHIV‐XJ02170 was infectious in human, rhesus monkey and cynomolgus monkey peripheral blood mononuclear cells (PBMC) and used CCR5 exclusively as coreceptor.
Results after replantation of avulsed permanent teeth. II. Periodontal healing and the role of physiologic storage and antiresorptive‐regenerative therapy
Authors: Pohl Yango , Filippi Andreas , Kirschner Horst
Published: March 2005

Abstract –  The status of the periodontal ligament (PDL) and of the pulp are decisive for the healing of avulsed and replanted teeth. A tooth rescue box was developed and distributed to offer optimal storage conditions for avulsed teeth. The therapy comprised extraoral endodontic treatment and applications of medicaments to enhance periodontal healing. In this long‐term clinical study the healing results following avulsion and replantation were investigated. Twenty‐eight permanent teeth in 24 patients were evaluated. The extraoral storage media and periods varied considerably. Soon after avulsion six teeth were stored in a cell culture medium (tooth rescue box Dentosafe®) for 1–53 h; the PDL was defined as not compromised. Sixteen teeth were stored in a non‐physiologic situation temporarily, the PDL was considered as compromised. Six teeth were stored in non‐physiologic conditions for longer periods; the condition of the PDL was defined as hopeless. On 14 teeth antiresorptive‐regenerative therapy (ART) with the local application of glucocorticoids and enamel matrix derivative and the systemic administration of doxycyclin was used. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. The mean observation period was 31.2 months (±24.1; 5.1–100.2; median: 23.8). All six teeth rescued physiologically healed with a functional PDL (functional healing, FH) irrespective of the storage period. Of eight teeth with a compromised PDL on which ART was used, three teeth healed with a functional PDL. All other teeth showed replacement resorption, in three teeth additionally infection‐related resorption was recorded. The predominant influence on the healing results was the immediate physiologic rescue of avulsed teeth (chi‐square, P = 0.0001). The use of ART seemed to support FH (chi‐square, P = 0.0547) in teeth with a compromised PDL. No other factors (maturity of roots, crown fractures, gender, age, antibiotics) were related to healing. In a linear regression analysis physiologic storage (P = 0.0013) and ART (P = 0.0421) were related to FH. For a good prognosis avulsed teeth should be stored immediately in a cell‐compatible medium. Therefore the tooth rescue box should be distributed at places with higher risks of accidents, in families with children and in emergency facilities. The use of ART might have potential for enhancing the prognosis of teeth with a PDL that is compromised but not in a hopeless condition. Extraoral endodontic treatment reduces infection‐related complications; this item was discussed in the first part of the publication.
The Broad‐Spectrum Cation Channel Blocker Pinokalant (LOE 908 MS) Reduces Brain Infarct Volume in Rats: A Temperature‐Controlled Histological Study
Authors: Christensen Thomas , Wienrich Marion , Ensinger Helmut A. , Diemer Nils Henrik
Published: March 2005

Abstract: Activation of cation channels conducting Ca2+, Na+ and K+ is involved in the pathogenesis of infarction in experimental focal cerebral ischaemia. Pinokalant (LOE 908 MS) is a novel broad‐spectrum inhibitor of several subtypes of such channels and has previously been shown to improve the metabolic and electrophysiologic status of the ischemic penumbra and to reduce lesion size on magnetic resonance images in the acute phase following middle cerebral artery occlusion in rats. The purpose of the present study was to investigate whether these beneficial effects of pinokalant are translated into permanent neuroprotection in terms of a reduction in infarct size one week after middle cerebral artery occlusion in rats. Halothane‐anaesthetized male Wistar rats subjected to permanent distal middle cerebral artery occlusion were randomly assigned to one of two treatment groups: 1) Control (vehicle intravenous loading dose followed by infusion); 2) Pinokalant (0,5 mg/kg intravenous loading dose followed by infusion of 1.25 mg/kg/hr). Infusions started 30 min. after middle cerebral artery occlusion and were continued for 24 hr. Body temperature and mean arterial blood pressure were monitored by telemetry during this period and the spontaneous temperature after course in control rats established in other experiments was imitated. Seven days later histological brain sections were prepared and the infarct volumes measured. Body temperature did not differ between the groups. Mean arterial blood pressure was slightly higher in the pinokalant group. Pinokalant treatment significantly reduced cortical infarct volume from 33.8±15.8 mm3 to 24.5±13.1 mm3 (control group versus pinokalant group, P=0.017, t‐test). Taking the effective drug plasma concentration established in other experiments into account revealed that in rats with plasma concentrations within the therapeutic interval, infarct volumes were further reduced to 17.9±7.5 mm3 (P<0.005).
SENSORY SHELF‐LIFE ESTIMATION OF ALFAJOR BY SURVIVAL ANALYSIS
Authors: GÁMBARO ADRIANA , GIMÉNEZ ANA , VARELA PAULA , GARITTA LORENA , HOUGH GUILLERMO
Published: March 2005

Survival analysis methodology was used to estimate the shelf life of alfajor (a chocolate‐coated individually wrapped cake) at 20 and 35C by using results obtained from consumers when asked if they would accept or reject samples with different storage times.

Sensory acceptability (measured by consumers), off‐flavor (measured by a trained panel) and moisture content were linearly related to time. These correlations were used to estimate values at the shelf‐life times calculated for 25 and 50% rejection probability.

Survival analysis provided the following shelf‐life estimation: 74 days at 20C and 33 days at 35C for a 25% of rejection, 87 days at 20C and 39 days at 35C for a 50% of rejection.

An alfajor stored at 20C having an acceptability value below 4.9 (1–9 hedonic scale) and off‐flavor intensity above 5.3 (0–10 scale) would be rejected by 25% of the consumers.

Chemical data were not good shelf‐life predictors.
QUANTIFYING FLUID FOOD TEXTURE
Authors: POLLEN N.R. , DAUBERT CHRISTOPHER R. , PRABHASANKAR P. , DRAKE M.A. , GUMPERTZ M.L.
Published: March 2005

Instrumental and sensory methods were studied to quantify specific textural attributes of fluid foods. Of the numerous tests performed, instrumental and sensory analyses each identified appropriate techniques for viscosity and yield stress evaluation. Multivariate analyses showed good correlation between these select methods for instrumental and sensory viscosity (r = 0.90) and yield stress (r = 0.96). Individually, principal component analysis showed differentiation between viscosity and yield stress methods, indicating these properties measured separate textural attributes of fluid foods. Although viscosity and yield stress are not the sole properties comprising fluid food texture, in combination these properties provide a more complete description of fluid food texture.
Virtual Slope Control of a Forward Dynamic Bipedal Walker
Authors: Russell S. , Granata K. P. , Sheth P.
Published: March 2005

Active joint torques are the primary source of power and control in dynamic walking motion. However the amplitude, rate, timing and phasic behavior of the joint torques necessary to achieve a natural and stable performance are difficult to establish. The goal of this study was to demonstrate the feasibility and stable behavior of an actively controlled bipedal walking simulation wherein the natural system dynamics were preserved by an active, nonlinear, state-feedback controller patterned after passive downhill walking. A two degree-of-freedom, forward-dynamic simulation was implemented with active joint torques applied at the hip joints and stance leg ankle. Kinematic trajectories produced by the active walker were similar to passive dynamic walking with active joint torques influenced by prescribed walking velocity. The control resulted in stable steady-state gait patterns, i.e. eigenvalue magnitudes of the stride function were less than one. The controller coefficient analogous to the virtual slope was modified to successfully control average walking velocity. Furture developments are necessary to expand the range of walking velocities.
A Comparison Between Mechano-Electrochemical and Biphasic Swelling Theories for Soft Hydrated Tissues
Authors: Wilson W. , van Donkelaar C. C. , Huyghe J. M.
Published: March 2005

Biological tissues like intervertebral discs and articular cartilage primarily consist of interstitial fluid, collagen fibrils and negatively charged proteoglycans. Due to the fixed charges of the proteoglycans, the total ion concentration inside the tissue is higher than in the surrounding synovial fluid (cation concentration is higher and the anion concentration is lower). This excess of ion particles leads to an osmotic pressure difference, which causes swelling of the tissue. In the last decade several mechano-electrochemical models, which include this mechanism, have been developed. As these models are complex and computationally expensive, it is only possible to analyze geometrically relatively small problems. Furthermore, there is still no commercial finite element tool that includes such a mechano-electrochemical theory. Lanir (Biorheology, 24, pp. 173–187, 1987) hypothesized that electrolyte flux in articular cartilage can be neglected in mechanical studies. Lanir’s hypothesis implies that the swelling behavior of cartilage is only determined by deformation of the solid and by fluid flow. Hence, the response could be described by adding a deformation-dependent pressure term to the standard biphasic equations. Based on this theory we developed a biphasic swelling model. The goal of the study was to test Lanir’s hypothesis for a range of material properties. We compared the deformation behavior predicted by the biphasic swelling model and a full mechano-electrochemical model for confined compression and 1D swelling. It was shown that, depending on the material properties, the biphasic swelling model behaves largely the same as the mechano-electrochemical model, with regard to stresses and strains in the tissue following either mechanical or chemical perturbations. Hence, the biphasic swelling model could be an alternative for the more complex mechano-electrochemical model, in those cases where the ion flux itself is not the subject of the study. We propose thumbrules to estimate the correlation between the two models for specific problems.
Response to ‘‘The conventionality of synchronization’’
Authors: Brehme Robert W.
Published: March 2005

Clocks may be synchronized in an inertial frame absolutely, in the sense that the simultaneity of events has physical significance. Concepts of simultaneity and synchronization are not merely matters of convention. A method is given in which clocks may be synchronized without the use of light signals.
The proton enigma
Authors: Aspden H.
Published: March 2005

It is suggested that the proton and neutron magnetic moments can be calculated by a theory involving a standing wave systems centered on the proton. (AIP)
On force and the inertial frame
Authors: Brehme Robert W.
Published: March 2005

The logical difficulty surrounding the definition of an inertial frame and Newton’s first law of motion can be circumvented by defining the inertial frame in terms of its spatial and temporal properties, as embodied in the special theory of relativity. Whether or not these properties apply can be determined, in principle, by experiment. The mass of a body is measured through a completely inelastic collision with a body whose mass is taken as the standard. Rather than attempt to define force by a means not involving Newton’s second law, we use the second law as the definition.
Hole gratings for optics experiments
Authors: Wiggins T. A.
Published: March 2005

The use of hole gratings, a regular arrangement of round holes in a thin opaque sheet, in an advanced laboratory is discussed. The effects of the hole size, spacing, and arrangement and of the grating aperture are demonstrated. Experiments are suggested which illustrate interference and diffraction effects and spatial filtering.
Random walk and magnetization of spin clusters in spin glasses
Authors: Chowdhury Debashish , Mookerjee Abhijit
Published: March 2005

We illustrate the application of the theory of random walk to spin glasses. We define an N cluster as a set of N spins, where the spins are ‘‘frozen’’ in random directions. We then calculate the probability P(M,N) that an N cluster will have net megnetization M. The method also encompasses quantum spins, a generalization not attempted before. We indicate the possibility of applying the theory of random walk on a random walk to spin glasses.
Stokes vectors, Mueller matrices, and polarized scattered light
Authors: Bickel William S. , Bailey Wilbur M.
Published: March 2005

The complete characterization of scattered light is described in the context of Stokes vectors and Mueller matrices which highly motivates the measuring procedures. The most general form of the scattering matrix coupled with polarizers and quarter wave plates elegantly demonstrates the physical relationship among the matrix elements and polarization measurements.
Efficiency of some heat engines at maximum-power conditions
Authors: De Vos Alexis
Published: March 2005

In the present paper a simple model is presented for a heat engine, where the power output is limited by the rate of heat supply (and/or heat release). The model leads to a variety of results. Some of them are established laws such as the Carnot law, the Curzon–Ahlborn efficiency, and the Castañs efficiency. Other results are new, and are related to phenomena as different as geothermal energy conversion and the Penfield paradox of electric circuits.
Resource letter MP-1: Medical physics
Authors: Hobbie Russell K.
Published: March 2005

This resource letter provides a guide to the literature on the uses of physics for the diagnosis and treatment of disease. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of somewhat more specialized nature; and the letter A indicates rather specialized or advanced material. An asterisk (*) indicates those articles to be included in an accompanying Reprint Book.
Factors affecting performance in introductory physics courses
Authors: Griffith W. T.
Published: March 2005

Tests of formal operational reasoning and mathematics knowledge have been correlated with performance measures in introductory physics courses. A score based on collected homework was also used in our analyses in an attempt to control for the confounding effects of study effort. Course totals were broken down into separate scores for performance on test problems and performance on conceptual questions. A multiple-regression analysis indicates that the test of formal operational reasoning is a stronger predictor of course performance than the mathematics pre-test, particularly for the conceptual portion of the course totals. Possible reasons for failure in some studies to find significant correlations of course performance with measures of formal reasoning are discussed.
Kaluza–Klein unified field theory and apparent four-dimensional space-time
Authors: Chyba Christopher F.
Published: March 2005

In the 1920s Kaluza and Klein achieved an elegant unified theory of gravitation and electromagnetism by assuming that space-time is really 5-dimensional. Their approach has since been extended to even higher dimensions in an effort to provide a geometrical unification of all the fundamental interactions. Any such scheme must answer the obvious objection emphasized by Einstein: Why, then, does space-time appear to be only 4-dimensional? This paper provides a semihistorical introduction to Kaluza–Klein unification on a level accessible to those with a basic knowledge of general relativity and particle physics, and examines the progress made in answering Einstein’s, and related, objections.
A rotary Curie point magnetic engine: A simple demonstration of a Carnot-cycle device
Authors: Toftlund Hans
Published: March 2005

The fact that metallic gadolinium is ferromagnetic with a Curie temperature of 294 K is used in the constuction of an inexpensive and simple thermomagnetic engine, which can be driven by an electric lamp or by sunlight. The apparatus can be used as a simple demonstration of the Carnot principle.
Student understanding of the work-energy and impulse-momentum theorems
Authors: Lawson Ronald A. , McDermott Lillian C.
Published: March 2005

Student understanding of the impulse-momentum and work-energy theorems was assessed by performance on tasks requiring the application of these relationships to the analysis of an actual motion. The participants in the study were undergraduates enrolled in either the honors section of a calculus-based introductory physics course or in the regular algebra-based course. The students were asked to compare the changes in momentum and kinetic energy of two frictionless dry-ice pucks as they moved rectilinearly under the influence of the same constant force. The results of the investigation revealed that most of the students were unable to relate the algebraic formalism learned in class to the simple motion that they observed.
Resource Letter MA-2: Musical acoustics
Authors: Rossing Thomas D.
Published: March 2005

This Resource Letter provides a guide to the literature on musical acoustics. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of a somewhat more specialized nature; and the letter A indicates rather specialized or advanced material. An asterisk (*) indicates articles that are especially useful or interesting; a double asterisk (**) indicates those articles to be included in an accompanying Reprint Book.
Fractal geometry in crumpled paper balls
Authors: Gomes M. A. F.
Published: March 2005

The geometry of crumpled paper balls is examined. The analysis stresses some physical, mathematical, and intuitive aspects of the problem, introducing the concept of fractal dimension which underlies many areas of modern physics.
Student difficulties in connecting graphs and physics: Examples from kinematics
Authors: McDermott Lillian C. , Rosenquist Mark L. , van Zee Emily H.
Published: March 2005

Some common errors exhibited by students in interpreting graphs in physics are illustrated by examples from kinematics. These are taken from the results of a descriptive study extending over a period of several years and involving several hundred university students who were enrolled in a laboratory-based preparatory physics course. Subsequent testing indicated that the graphing errors made by this group of students are not idiosyncratic, but are found in different populations and across different levels of sophistication. This paper examines two categories of difficulty identified in the investigation: difficulty in connecting graphs to physical concepts and difficulty in connecting graphs to the real world. Specific difficulties in each category are discussed in terms of student performance on written problems and laboratory experiments. A few of the instructional strategies that have been designed to address some of these difficulties are described.