bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying the Decision to Become a First-Time Home Buyer
Authors: Cooperstein Richard L. 
Published: October 2006

Becoming a first-time homebuyer is quantified in two stages using household data. A renter demand curve is estimated to calculate the consumer surplus gain from moving into housing consumption equilibrium. Probit is used to estimate the probability of becoming a first-time homebuyer. The model suggests that overcoming the transactions cost of buying, and the gain from housing consumption equilibrium are important to the decision. Renting is explained by current housing demand through income and family size. Buying for the first time is explained by factors which reduce transactions costs, such as assets, marital status, and education. Disequilibrium in rental housing consumption is also important. The results further suggest that permanent income is not important to the decision.
An attack of the plant parasite Cuscuta reflexa induces the expression of attAGP, an attachment protein of the host tomato
Authors: Albert Markus , Belastegui‐Macadam Xana , Kaldenhoff Ralf 
Published: October 2006

SummaryDodder or Cuscutaceae are holoparasitic plants subsisting on other dicotyledonous plants. The infection process is initiated by adherence of Cuscuta prehaustoria to the host surface, followed by penetration attempts by hyphae. In the case of a successful infection, these organs connect the parasite's vascular tissue to that of the host. Here we show that contact of Cuscuta reflexa prehaustoria to tomato induces the expression of a new arabinogalactan protein (AGP), attAGP, in the tomato precisely at the site of dodder attack. We show that attAGP is a plasma membrane‐bound cell wall‐localized protein. Using the RNAi technique and attAGP‐targeted virus‐induced gene silencing, we observed a correlation between attAGP expression level and force of attachment of the parasite to host tomatoes. If the expression level of attAGP was reduced, the C. reflexa attachment capability was significantly reduced, too. We conclude that C. reflexa infection induced a signal in the host leading to expression of tomato attAGP, which promotes the parasite's adherence.
Building trust and shared knowledge in communities of e‐learning practice: collaborative leadership in the JISC eLISA and CAMEL lifelong learning projects
Authors: Jameson Jill , Ferrell Gill , Kelly Jacquie , Walker Simon , Ryan Malcolm 
Published: October 2006

AbstractTrust and collective learning are useful features that are enabled by effective collaborative leadership of e‐learning projects across higher and further education (HE/FE) institutions promoting lifelong learning. These features contribute effectively to the development of design for learning in communities of e‐learning practice. For this, reflexivity, good leadership and the capacity to engage in innovation is crucial to team performance. This paper outlines a serendipitously useful combination of innovative models of collaboration emerging from two 2005–06 UK e‐learning pilots: the Joint Information Systems Committee (JISC) e‐Learning Independent Study Award (eLISA) and JISC infoNet Collaborative Approaches to the Management of e‐Learning (CAMEL) projects. The JISC‐funded eLISA Distributed e‐Learning (DeL) project set up a collaborative partnership among teachers to try out LAMS and Moodle using study skills in e‐learning. Simultaneously, the JISC infoNet CAMEL project developed a model of collaborative approaches to e‐learning leadership and management across four UK HE/FE institutions. This paper proposes two new theoretical collaborative team leadership and operational models for e‐learning projects, including indices of trust, reflexivity and shared procedural knowledge, recommending that these models are further developed in future communities of e‐learning practice in institutions promoting lifelong learning.
Compatible measurements of volumetric soil water content using a neutron probe and Diviner 2000 after field calibration
Authors: Burgess P. J. , Reinhard B. R. , Pasturel P. 
Published: October 2006

AbstractField calibrations for a neutron probe and a capacitance sensor (Diviner 2000) for measuring the soil water content of a shrinking–swelling clay soil were substantially different from commonly used default values. Using our field calibrations, the two instruments estimated similar changes in the cumulative water content of a soil profile (0–1 m depth) over one growing season.
Early Loading of Unsplinted Implants Supporting Mandibular Overdentures Using a One‐Stage Operative Procedure with Two Different Implant Systems: A 2‐Year Report
Authors: Tawse‐Smith Andrew , Payne Alan G.T. , Kumara Rohana , Thomson W. Murray 
Published: October 2006

ABSTRACT Background: Step‐wise reduction in loading protocols is necessary to evaluate early loading of implants with mandibular overdentures. Purpose: To compare the success rates of two different dental implant systems following conventional or early loading protocols in patients being rehabilitated with mandibular overdentures. Materials and Methods: Forty‐eight edentulous participants were randomly allocated to two different implant systems: one with a machined titanium implant surface (Sterioss, Nobel Biocare, Yorba Linda, California, USA) and the other with a roughened titanium surface (Southern Implants, Irene, South Africa). For each system, the participants were further divided into control groups, in whom mandibular implant overdentures and their respective matrices were inserted following a standard 12‐week healing period, and test groups, in whom a 6‐week healing period was followed prior to identical loading. Two unsplinted implants to support implant overdentures were placed in the anterior mandible of all participants, using a standardized one‐stage surgical procedure. Mobility tests and marginal bone levels, as well as periimplant parameters, were evaluated at each baseline and 52 and 104 weeks after surgery. Results: There was no statistically significant difference in the success rates of the two systems in either control or test groups. At the 2‐year evaluation, a success rate was found of 87.5% and 70.8.% for the control and test Sterioss groups, respectively, and 83.3% and 100% for the control and test Southern Implants groups were observed. For the Sterioss groups, eight implants were lost at an early stage: seven in the test group and one in the control group. For the Southern Implants control and test groups, no failures were seen at any time interval. There were no significant differences in marginal bone loss, Periotest values, and peri‐implant parameters between implant systems or between any of the control or test groups. Conclusions: Early loading, with step‐wise reductions in loading protocols, of unsplinted machined Sterioss and roughened Southern Implants fixtures with mandibular overdentures is possible for up to 2 years.
Five‐Year Prospective Study of Immediate/Early Loading of Fixed Prostheses in Completely Edentulous Jaws with a Bone Quality‐Based Implant System
Authors: Misch Carl E. , Degidi Marco 
Published: October 2006

ABSTRACT Background: The concept of immediate loading of root‐form implants for fixed restorations has received increasing interest over the last 5 years. Several authors have commented on parameters that may influence results, including implant number, implant length, bone density, and patient habits. The trigger for bone remodeling around an implant may occur from the surgical trauma of insertion or the mechanical environment of strain at the interface. In the classic two‐stage approach, these were divided episodes, separated by 3 to 6 months. Immediate loading compresses this time frame; the two driving mechanisms for bone repair occur concurrently. A scientific approach to the interface development is to match the bone healing response of trauma (woven bone of repair) to the response of mechanical load (reactive woven bone), so the sum of these two entities does not result in fibrous tissue formation and clinical mobility of the implant. Purpose: It is the purpose of this article to review the scientific rationale of these statements and coordinate them to bone physiology and bone biomechanics. Materials and Methods: Findings from previous reports in the literature were reviewed and summarized to form the basis of a prospective study using a bone quality‐based implant system (Biohorizons, Maestro Dental Implants, Birmingham, AL, USA). A transitional prosthesis was delivered either on the day of surgery or within 2 weeks for 30 patients and 31 arches. A total of 244 implants were used to support these restorations, for an average of 7.8 implants per prosthesis. After 4 to 7 months, the final restorations were fabricated. One year after the final restoration was loaded, the implant survival was 100%; the 31 restorations also had a survival of 100% over this time frame. This report presents these implants and restorations over a 1‐ to 5‐year period, with an average follow‐up period of 2.6 years. Results: The bone loss from implant insertion to final prosthesis delivery averaged 0.7 mm. The first‐year bone loss after final prosthesis delivery averaged 0.07 mm. A slight increase in bone height was observed after the first year, but generally no increase was observed over the remaining evaluation period. Conclusions: In the current report, no implant failure occurred, and crestal bone loss values were similar to or less than values reported with the conditional two‐stage approach. This may be related to the number and position of implants, implant design, and/or the surface condition of the implant loading.
Donor Site Morbidity in Two Different Approaches to Anterior Iliac Crest Bone Harvesting
Authors: Cricchio Giovanni , Lundgren Stefan 
Published: October 2006

ABSTRACT Background: Bone grafting is a surgical technique for the reconstruction of the atrophic edentulous maxilla prior to treatment with endosseous implants. The anterior iliac crest is a commonly used donor site. Purpose: The aim of this study was to evaluate the donor site morbidity and complications when harvesting corticocan‐cellous bone from the medial table of the anterior iliac crest and compare this with results when bone was harvested from the lateral and superior table of the anterior iliac crest. In addition, the outcome of the oral rehabilitation was evaluated by means of a quality‐of‐life questionnaire. Material and Methods: The study was composed of 70 consecutively treated patients with a mean age of 56 years. The patients were retrospectively evaluated with regard to postoperative donor site morbidity and complications at the donor site. Results: For the donor site morbidity, 74% of the patients were free of pain within 3 weeks, whereas 26% of the patients had a prolonged period of pain lasting from a few weeks to several months. For 11% of the patients, there was still some pain or discomfort 2 years after the grafting surgery. For gait disturbance the figures were similar:79% had no problems after 3 weeks.For the eight patients who still had some pain after 2 years, which was considered permanent, three also had gait disturbance. There was a total of three major complications (4%), one iliac wing fracture and two neurologic injuries. Conclusion: When harvesting a large amount of unicortical corticocancellous bone blocks from the the superolateral site of the iliac crest with a “peel off’ technique, morbidity and complication rates do not differ significantly compared with those of the traditional anterior medial approach. Oral rehabilitation with maxillary reconstruction with bone grafts from the iliac crest and endosseous implants significantly improved oral function, facial appearance, and recreation/social activities and resulted in an overall improvement in quality of life in formerly edentulous patients.
Short‐Term Bone Response to Titanium Implants Coated with Thin Radiofrequent Magnetron‐Sputtered Hydroxyapatite in Rabbits
Authors: Mohammadi Shams , Esposito Marco , Hall Jan , Emanuelsson Lena , Krozer Anatol , Thomsen Peter 
Published: October 2006

ABSTRACT Background: It has been suggested that calcium phosphate (CaP) coatings initiate faster bone growth around implants. A major concern about the viable use of these coatings has been their biologic performance related to the coating characteristics. Purpose: The purpose of this study was to investigate the early bone response to micron‐ and submicron‐thick hydroxya‐patite (HA) coatings in cortical and trabecular bone. Materials and Methods: CaP coatings were manufactured by magnetron sputtering. Heat treatment was subsequently used to increase the crystallinity of the coatings. Coatings were characterized by x‐ray diffraction, Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP‐OES), and stylus profilometry. Four types of CaP‐coated implants were used (0.1 urn and 2.0 μm amorphous; 0.1 um and 2.0 μn crystalline); uncoated machined commercially pure titanium implants served as controls.Four hundred eighty implants were randomly placed in 60 rabbits. Ten animals were followed up for 1 week, 10 for 3 weeks, and 40 for 6 weeks. The bone response was histomorphometrically evaluated. Results: Coatings with a CaP ratio very close to that of HA were produced. Crystalline coatings significantly improved the early bone‐implant contact whereas the amorphous‐coated implants behaved similarly to uncoated titanium. Conclusions: Crystalline CaP coatings 100 nm thick on titanium implants elicited an improved early bone response compared with that of uncoated titanium implants. No further improvement in the bone response was observed with 2 μm coatings.
A Surgical Stent for the Brånemark Novum® Bone Reduction Procedure
Authors: Barteaux Laurent , Daelemans Philippe , Malevez Chantal 
Published: October 2006

ABSTRACTBackground:The Brånemark Novum® concept (Nobel Biocare AB, Göteborg, Sweden) was introduced to load implants immediately with a definitive fixed prosthesis in the edentulous mandible. This concept is based on the use of prefabricated templates to allow precise placement of three implants and a prefabricated bar structure for the prosthetic procedure. To obtain three‐dimensional stability in these prefabricated templates, surgical bone reduction may be necessary to obtain a stable adaptation between the templates and the recipient bone site.Purpose:The aim of this work was to design a surgical stent for predictable reduction of the residual alveolar crest prior to the implant placement procedures.Materials and Methods:A predetermined alveolar crest platform based essentially on a lateral cephalometric radiographic evaluation was simulated on a cast in order to design a transparent resin surgical guide. The predictability potential of the procedure was then evaluated in 10 patients. The prosthetic outcomes were compared with those of a similar group of 10 patients treated without the presented stent by evaluating two factors, namely, the anterior dimensions of the prostheses and the required posterior adjustments of the upper bar.Results:Correlation analysis of our series suggested a good predictability potential for this procedure (r= 0.9215). The mean anterior prosthetic dimension was 32% lower and was more predictable (narrow range of 8–12 mm vs broad range of 8–21 mm) when the stent was used. Furthermore, since half as many posterior adjustments of the upper bar were required, the laboratory procedure was facilitated.Conclusion:This individualized guide allows appropriate bone reduction for obtaining a predictable surgery and prosthetic stage.
Maxillary Sinus Elevation Surgery: An Overview
Authors: KAUFMAN ELIAZ 
Published: October 2006

ABSTRACTMaxillary sinus elevation surgery was developed to increase the height of bone available for implant placement in the posterior maxilla. The efficacy and predictability of this procedure have been determined in numerous studies. The basic approach to the sinus (Caldwell‐Luc operation) involves an osteotomy performed on the lateral maxillary wall, elevation of the sinus membrane, and placement of bone graft material. The graft materials can be categorized into four groups: autogenous bone, allografts (harvested from human cadavers), alloplasts (synthetic materials), and xenografts (grafts from a nonhuman species). These graft materials can be used alone or in combination with each other. Implant placement can occur at the same surgical procedure (immediate placement) or following a healing period of 6 to 9 months (delayed placement). A more conservative approach to the sinus, the osteotome technique, has been described as well.CLINICAL SIGNIFICANCEThis article provides an overview of the surgical technique, with emphasis on anatomic considerations, preoperative patient evaluation (clinical and radiographic), indications and contraindications to the procedure, and possible risks and complications.
Use of a Reflectance Spectrophotometer in Evaluating Shade Change Resulting from Tooth‐Whitening Products
Authors: STEPHEN J. 
Published: October 2006

ABSTRACTHistorically, shade change assessment associated with vital bleaching treatment regimens has been visually evaluated through the use of shade guide tabs. Innovations in the industry of dentistry have brought forth new technologies capable of measuring such changes via the capture and analysis of reflected wavelengths of light.CLINICAL SIGNIFICANCEThis article introduces the use of a 45/0 reflectance spectrophotometer and identifies the advantages and limitations associated with such a technology in the assessment of shade change owing to vital bleaching.
Bond Strengths of Current Adhesive Systems on Intact and Ground Enamel
Authors: SENAWONGSE PISOL , SATTABANASUK VANTHANA , SHIMADA YASUSHI , OTSUKI MASAYUKI , TAGAMI JUNJI 
Published: October 2006

ABSTRACTPurpose:The goal of this study was to compare the microshear bond strengths of current adhesive systems to intact and ground enamel surfaces.Materials and Methods:Three commercially adhesive materials were examined: a two‐step total‐etching self‐priming system (Single Bond®, 3M ESPE, St. Paul, MN, USA), a two‐step self‐etching system (Clearfil SE Bond®, Kuraray Co. Ltd., Osaka, Japan), and an all‐in‐one system (One‐Up Bond® F, Tokuyama Dental, Tokyo, Japan). The labial surfaces of extracted human incisors were used. For intact enamel surfaces, the teeth were polished with pumice. However, for the ground enamel, 0.5 mm deep, flat enamel surfaces at the midlabial aspect were ground with a no. 600 grit silicon carbide paper. Ground and intact enamel surfaces were bonded with one of three bonding systems and a resin composite and were subjected to a microshear bond test.Results:The two self‐etching systems demonstrated lower bond strengths than did the total‐etching system on intact enamel (One‐Up Bond F, 18.59 MPa; Clearfil SE Bond, 35.71 MPa; Single Bond, 47.20 MPa). No significant difference was found between the total‐etching system and the two‐step self‐etching system on ground enamel (One‐Up Bond F, 28.96 MPa; Clearfil SE Bond, 48.51 MPa; Single Bond, 51.07 MPa). Shear bond strengths on ground enamel were significantly higher than those on intact enamel except for the group that was bonded with the total‐etching system.Conclusions: The two‐step adhesives showed significantly higher bond strengths than did the one‐step adhesive. When applying the total‐etching system, no significant differences in bond strength were demonstrated between bonding to intact and to ground enamel.
An Alternative to Brain Death
Authors: McMahan Jeff 
Published: October 2006

Most contributors to the debate about brain death, including Dr. James Bernat, share certain assumptions. They believe that the concept of death is univocal, that death is a biological phenomenon, that it is necessarily irreversible, that it is paradigmatically something that happens to organisms, that we are human organisms, and therefore that our deaths will be deaths of organisms. These claims are supposed to have moral significance. It is, for example, only when a person dies that it is permissible to extract her organs for transplantation.It is also commonly held that our univocal notion of death is the permanent cessation of integrated functioning in an organism and that the criterion for determining when this has occurred in animals with brains is the death of the brain as a whole – that is, brain death. The reason most commonly given for this is that the brain is the irreplaceable master control of the organism's integration.
Reviews in Medical Ethics: “Open Access,” Legal Publishing, and Online Repositories
Authors: Bluh Pamela 
Published: October 2006

The Open Access Movement maintains that all scientific and scholarly literature should be available to all for free via the Internet. This concept is not new. Some scholars trace its roots as far back as 1963 when “hypertext” was first introduced. Although the Open Access Movement may have originated more than fifty years ago, it has been fueled by more recent events, including the unremitting escalation of journal subscription prices over the last two decades, resulting in massive cancellations of journals by academic libraries; the ubiquitous nature of the Internet and the parallel explosion of electronic resources; and the desire of authors to find a new publishing model which continues to offer the benefits of peer review while providing for more rapid publication and wide-spread distribution than the current labor-intensive, time-consuming model.The Open Access Movement has resulted in a number of online repositories devoted to legal analysis and policy. This column explores the genesis of the movement, its value to researchers and policymakers, and provides an overview of the two principal open access products in the legal arena.
The Seasonal Variability of the Arctic Ocean Ekman Transport and Its Role in the Mixed Layer Heat and Salt Fluxes
Authors: Yang Jiayan 
Published: October 2006

Abstract
The oceanic Ekman transport and pumping are among the most important parameters in studying the ocean general circulation and its variability. Upwelling due to the Ekman transport divergence has been identified as a leading mechanism for the seasonal to interannual variability of the upper-ocean heat content in many parts of the World Ocean, especially along coasts and the equator. Meanwhile, the Ekman pumping is the primary mechanism that drives basin-scale circulations in subtropical and subpolar oceans. In those ice-free oceans, the Ekman transport and pumping rate are calculated using the surface wind stress. In the ice-covered Arctic Ocean, the surface momentum flux comes from both air–water and ice–water stresses. The data required to compute these stresses are now available from satellite and buoy observations. But no basin-scale calculation of the Ekman transport in the Arctic Ocean has been done to date. In this study, a suite of satellite and buoy observations of ice motion, ice concentration, surface wind, etc., will be used to calculate the daily Ekman transport over the whole Arctic Ocean from 1978 to 2003 on a 25-km resolution. The seasonal variability and its relationship to the surface forcing fields will be examined. Meanwhile, the contribution of the Ekman transport to the seasonal fluxes of heat and salt to the Arctic Ocean mixed layer will be discussed. It was found that the greatest seasonal variations of Ekman transports of heat and salt occur in the southern Beaufort Sea in the fall and early winter when a strong anticyclonic wind and ice motion are present. The Ekman pumping velocity in the interior Beaufort Sea reaches as high as 10 cm day−1 in November while coastal upwelling is even stronger. The contributions of the Ekman transport to the heat and salt flux in the mixed layer are also considerable in the region.