bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Contributions to Patient Safety Knowledge by the Agency for Healthcare Research and Quality‐Funded Patient Safety Projects
Authors: Sorbero Melony E.S. , Ricci Karen A. , Lovejoy Susan , Haviland Amelia M. , Smith Linda , Bradley Lily A. , Hiatt Liisa , Farley Donna O.
Published: December 2008

Objective. To characterize the activities of projects funded in Agency for Healthcare Research and Quality (AHRQ)'s patient safety portfolio and assess their aggregate potential to contribute to knowledge development.

Data Sources. Information abstracted from proposals for projects funded in AHRQ's patient safety portfolio, information on safety practices from the AHRQ Evidence Report on Patient Safety Practices, and products produced by the projects.

Study Design. This represented one part of the process evaluation conducted as part of a longitudinal evaluation based on the Context–Input–Process–Product model.

Principal Findings. The 234 projects funded through AHRQ's patient safety portfolio examined a wide variety of patient safety issues and extended their work beyond the hospital setting to less studied parts of the health care system. Many of the projects implemented and tested practices for which the patient safety evidence report identified a need for additional evidence. The funded projects also generated a substantial body of new patient safety knowledge through a growing number of journal articles and other products.

Conclusions. The projects funded in AHRQ's patient safety portfolio have the potential to make substantial contributions to the knowledge base on patient safety. The full value of this new knowledge remains to be confirmed through the synthesis of results.
Evaluation of the AHRQ Patient Safety Initiative: Synthesis of Findings
Authors: Farley Donna O. , Damberg Cheryl L.
Published: December 2008

Objective. To present overall findings from the 4‐year evaluation of the national patient safety initiative operated by the Agency for Healthcare Research and Quality (AHRQ).

Data Sources. Interviews with AHRQ staff, grantees, and other patient safety stakeholders; published materials; and internal AHRQ documents.

Study Design. The evaluation was structured to address a system framework of five components involved in improving safety. The initiative's contributions to improving each system component were assessed qualitatively, comparing results from three separate analyses—AHRQ's achievement of its patient safety goals, our own assessment of the initiative's activities, and independent stakeholder ratings of AHRQ's contributions.

Findings and Conclusions. AHRQ has faced a daunting challenge for improving patient safety, given the complex problems of the U.S. health care system and the limited resources AHRQ has had to address them. The patient safety initiative achieved strongest progress for its contributions to knowledge of patient safety epidemiology and effective practices, where AHRQ has considerable experience, and to strengthening infrastructure to support adoption of safe practices. Progress was slower in establishing a national monitoring capability and dissemination of safe practices for adoption. AHRQ needs to expand efforts to apply new knowledge for stimulating use of safe practices in the field.
TRUTH AND WHAT IS SAID*
Authors: Zardini Elia
Published: December 2008

A notion oftruthas applicable to events of assertoric use (utterances) of a sentence token is arguably presupposed and required by our evaluative practices of the use of language. The truth of an utterance seems clearly to depend on what the utterancesays. This fundamental dependence seems in turn to be captured by the schema that, if an utteranceusays thatP, thenuis true iffP. Such a schema may thus be thought to constitute a suitable basis for an adequate theory of utterance truth, so much so that it seems straightforwardly to avoid the problems arising fromcontext dependenceand thesemantic paradoxeswhich notoriously beset theories of utterance truth based on a simpledisquotationalschema. The paper argues that appearances are deceptive in both cases. On the one hand, the schema cannot allow for plausible if not uncontroversialnon‐indexicalforms of context dependence, arising from the possibility that what an utterance says can be the case or not relative to different situations and that the truth of an utteranceuof a sentence ϕ arguably depends on the truth of ϕ at the situation “associated” withu. On the other hand, aquantified utterance‐truthvariation on the liar paradox shows that the schema entails some consequence ϕ and at the same time the untruth of any utterance of ϕ; moreover, a resilientquantified propositionalvariation on the contingent liar paradox is offered, which only relies on resources usually employed by theories of utterance truth based on the schema.
Genesis of metapelitic migmatites in the Adirondack Mountains, New York
Authors: LANCASTER P. J. , FU B. , PAGE F. Z. , KITA N. T. , BICKFORD M. E. , HILL B. M. , McLELLAND J. M. , VALLEY J. W.
Published: December 2008

Oxygen isotope ratios and rare earth element (REE) concentrations provide independent tests of competing models of injection v. anatexis for the origin of migmatites from amphibolite and granulite facies metasedimentary rocks of the Adirondack Mountains, New York. Values of δ18O and REE profiles were measured by ion microprobe in garnet–zircon pairs from 10 sample localities. Prior U–Pb SIMS dating of zircon grains indicates that inherited cores (1.7–1.2 Ga) are surrounded by overgrowths crystallized during the Grenville orogenic cycle (∼1.2–1.0 Ga). Cathodoluminescence imaging records three populations of zircon: (i) featureless rounded ‘whole grains’ (interpreted as metamorphic or anatectic), and rhythmically zoned (igneous) cores truncated by rims that are either (ii) discordant rhythmically zoned (igneous) or (iii) unzoned (metamorphic or anatectic). These textural interpretations are supported by geochronology and oxygen isotope analysis. In both the amphibolite facies NW Adirondacks and the granulite facies SE Adirondacks, δ18O(Zrc) values in overgrowths and whole zircon are highly variable for metamorphic zircon (6.1–13.4‰; n = 95, 10 μm spot). In contrast, garnet is typically unzoned and δ18O(Grt) values are constant at each locality, differing only between leucosomes and corresponding melanosomes. None of the analysed metamorphic zircon–garnet pairs attained oxygen isotope equilibrium, indicating that zircon rims and garnet are not coeval. Furthermore, REE profiles from zircon rims indicate zircon growth in all regions was prior to significant garnet growth. Thus, petrological estimates from garnet equilibria (e.g. P–T) cannot be associated uncritically with ages determined from zircon. The unusually high δ18O values (>10‰) in zircon overgrowths from leucocratic layers are distinctly different from associated metaigneous rocks (δ18O(Zrc) < 10‰) indicating that these leucosomes are not injected magmas derived from known igneous rocks. Surrounding melanosomes have similarly high δ18O(Zrc) values, suggesting that leucosomes are related to surrounding melanosomes, and that these migmatites formed by anatexis of high δ18O metasedimentary rocks.
Influence of Electrically Stimulated Ankle Plantar Flexors on the SwingingLeg
Authors: Bajd T. , Kralj A. , Karcˇnik T. , S˘avrin R. , Benko H. , Obreza P.
Published: December 2008

The influence of functional electricallystimulated ankle plantar flexors on the swinging lower extremitywas studied in incomplete spinal cord injured persons.Stimulation sequences with different time and frequencyparameters were delivered to ankle plantar flexors andknee extensors and to the peroneal nerve. The results ofkinematic assessment showed that stimulated calf musclesprovide noticeable forward and upward propulsion to theswinging leg.
Lumbar Root Stimulation for Restoring Leg Function: Results in Paraplegia
Authors: Rushton D.N. , Donaldson N. de N. , Barr F.M.D. , Harper V.J. , Perkins T.A. , Taylor P.N. , Tromans A.M.
Published: December 2008

We have implanted an intradural array of 12tripolar electrodes on the anterior roots L2–S2, left andright, at cauda equina level, in a33‐year‐old woman with acomplete T9 cord lesion of 3 years' duration. They aredriven by an implantedmultiplexed stimulator systemusing radio frequency (RF) power and controlsignals. All channels generate movements, in patterns that might be predicted from the known anatomyof the cauda equina. In particular, stimulation of L2 and L3 gives hipadduction; L3, L4, and L5gives quadriceps femoris movements; L5, S1, and S2 gives hamstrings movement;and S1 and S2 give plantar flexion. Stimulation of L5 gives mixed movements atthe ankle. Surprisingly, stimulation of the L2 roots has not given strong hip flexion.Responses have been stable. Some thresholds have varied, probably as a resultof tissue encapsulation.The moment generated within each degree of freedom of the legs has beenmeasured for each root, using a specially designed multimoment measurementapparatus. For several roots, amovement of lower threshold may be accompanied by a second movement of higherelectrical threshold, suggesting that different muscles may have fiberpopulations that differ intheir diameter or their location in the root. The use of stimulus forms thatenable selective anodal block may, in the future, enable separation of twodistinct movements from a single motor root.
Stability and Energy Criteria in Healthy and Paraplegic Subject Gait
Authors: Karčnik T. , Kralj A.
Published: December 2008

The functional electrical stimulation (FES) assisted gait of paraplegicpatients is inferior to that of healthy subjects. The difference can beobserved in terms of speed, upright balance, biomechanical energy consumption, andgeneration of propulsion forces in the direction of walking. The biomechanicalstructure of paraplegicsubjects is the same as that of normal ones; however, the mode of walkingdiffers significantly because of the reduced number of activated muscles andprimitive control. Thehealthy subject is utilizing a 2‐point dynamically stable gait. The paraplegicpatient is using 4‐channel FES and utilizing a 4‐point statically stablegait. We believe thatthe FES gait can be improved if converted into a semidynamically or dynamicallystable gait. The gait is considered statically stable if the center of gravity(COG) projection onthe ground (PCOG) is inside the supporting area. For a quadruped, this is onlypossible if it is utilizing a creeping crawl gait. In this paper, therelationship between PCOG andthe supporting area are discussed as a criterion for dynamic stabilityassessment. Results are shown for 3 different modes of 2‐point and 4‐pointgaits.
Functional Electrical Stimulation in Paraplegic Spastic Patients
Authors: Kern Helmut
Published: December 2008

We are reporting on the clinical and physiological effects of 8 months offunctional electrical stimulation (FES) of the quadriceps femoris muscle on 10paraplegic patients. Each patient had muscle biopsies, computed tomography (CT)muscle diameter measurements, and knee extension strength testing both beforeand after 8 months of FES training. Skin perfusion was documented throughinfrared telethermography and xenon clearance; muscle perfusion was recordedthrough thallium scintigraphy. After 8 months of FES training, the baselineskin perfusion showed an 86% increase; muscle perfusion was augmentedby 87%. Muscle fiber diameters showed an average increase of 59%after 8 months of FES training. Muscles in patients with spastic paresis showedan increase in aerobic and anaerobic muscle enzymes up to the normal range ofhealthy humans. The increment in muscle area, as visible on CT scans of thequadriceps femoris muscle, was 30%. Using FES, we were able to improvemetabolism and to induce positive trophic changes in our patients' lowerextremities. In spastic paraplegics, rising and walking achieved through FESare much better training than FES ergometer training. Larger muscle masses areactivated, and the heart rate is increased; therefore, the impact oncardiovascular fitness and metabolism is much greater. This effectivelyaddresses and prevents the problems that result from inactivity in paraplegicpatients.
Wireless Control of Functional Electrical Stimulation Systems
Authors: Matjačić Z. , Munih M. , Bajd T. , Kralj A. , Benko H. , Obreza P.
Published: December 2008

With the assistance of crutches and functional electrical stimulation (FES),we are able to restore standing and simple gait in some spinal cord injured(SCI) patients. In present rehabilitative systems, the patient divides the gait cycleinto stance and swing phases via pushbuttons mounted on the handles of thecrutches, which arehard‐wired to the functional electrical stimulator. The surface‐mounttechnology based telemetry system, which makes use of the radiofrequency mediumat 40 MHz, was developed toprovide wireless control of the FES system. Signals from crutch pushbuttonswere coded and transferred from the transmitter to the receiver. The receiverwas firmly attached to the patient's waist and was connected to thestimulator.
Improvement of Microcirculatory Blood Flow underEpidural Spinal Cord Stimulation in Patients withNonreconstructible Peripheral Arterial Occlusive Disease
Authors: Claeys Luc Georges Y.
Published: December 2008

Epidural spinal cord stimulation (ESCS) hasbeen suggested as a method to improve microcirculatoryblood flow and to reduce the amputation rate in vascularpatients. We studied the effects of ESCS onmicrocirculatory blood flow in 237 patients with nonreconstructibleperipheral arterial occlusive disease. Clinical status wasclassified as Fontaine Stage 3 (ischemic rest pain) in 169patients and as Fontaine Stage 4 (ulcers/gangrene) in 68patients. After a mean follow‐up period of 31.2 months,major pain relief (>75%) was noticed in patients whoretained their limbs. Sixty‐four patients underwent majoramputation despite ESCS. Clinical improvement wasconfirmed by the increase in transcutaneous oxygen(TcPo2).
Selective Detrusor Activation by Electrical Stimulation of the Human SacralNerve Roots
Authors: Rijkhoff N.J.M. , Hendrikx L.B.P.M. , Van Kerrebroeck P.E.V. , Debruyne F.M.J. , Wijkstra H.
Published: December 2008

The purpose of this study was to investigate the feasibility of selectivedetrusor activation without activation of the urethral sphincter by sacral rootstimulation in patients. The sacral roots were stimulated using a tripolarelectrode. An anodal block was used to prevent the urethral sphincter fromcontraction. Using squarecurrent pulses (700 μs, 6–7 mA), no increase in intraurethral pressurewas measured, while a normal increase in intravesical pressure occurred. Theminimum pulse duration toobtain a complete block was 550 μs. The study shows that anodal blocking ofaction potentials is possible in humans and can result in selective detrusoractivation when used in sacral root stimulation.
Natural Versus Artificial Sensors Applied in Peroneal Nerve Stimulation
Authors: Upshaw Barry J. , Sinkjær Thomas
Published: December 2008

We have attempted to quantify the performanceof natural versus artificial sensors when used in aclosed‐loop functional electrical stimulation system. Peronealnerve stimulation was applied during gait to a multiplesclerosis subject with a drop foot. Stimulation was appliedonly during the swing phase to provide artificially induceddorsiflexion of the foot. Detection of the onset of thestance phase was accomplished using a standard heelcontact switch mounted inside the subject's shoe (the artificialsensor) and using processed nerve signals derived from animplanted nerve‐cuff electrode (the natural sensor). Adetection percentage of at least 85% was achieved using theafferent nerve signal information only. When muscleactivity (also recorded in the cuff) and additionalinformation about the gait cycle were incorporated, functionaldetection ratios approaching 100% were achieved.
Effect of Adaptive Pulse Train Duration on Latissimus Dorsi Blood Flow
Authors: Gealow Kendra , Solien Eric , Bianco Richard , Grandjean Pierre
Published: December 2008

Blood flow, intramuscular pressure, and stroke work of the trainedlatissimus dorsi muscle (LD) were measured during electrical stimulation atcontraction ratesbetween 20 and 160/min using pulse trains of 2 to 6 pulses in length. Epimysialelectrodes and intramuscular pressure sensors were implanted in the LD of 5dogs. The muscleremained in situ. After 12 weeks of a progressive training protocol, LD bloodflow (BF) was measured using an ultrasonic flow probe and work (SW) wasdetermined from the measuredforce and shortening. For pulse trains of 2 or 3 pulses, BF increased with rate,and SW was maintained at all rates. For 4 pulses, BF and SW decreased when thecontraction rateexceeded 120/min. SW decreased above 100/min and 80/min for 5 and 6 pulses,respectively. An upper rate limit dependent upon the pulse train durationexists above which BF and SWdecline. Exceeding these upper rate limits should be avoided incardiomyoplasty. Excessive stimulation rates could be detrimental to the muscleby creating a metabolicinsufficiency or ischemia. The cardiac assistance benefit is compromised as SWdeclines during high contraction rates of long pulse train duration.
Lumbar Root Stimulation for Restoring Leg Function: Stimulator and Measurement of Muscle Actions
Authors: Donaldson N. de N. , Perkins T.A. , Worley A.C.M.
Published: December 2008

We are studying the feasibility of restoring lower limb functions toparaplegics by stimulating their lumbar anterior roots (L2‐S2). The potentialadvantages ofplacing electrodes at the roots, at the cauda equina, were set out by Rushton(1), and our results so far are in a companion paper by Rushton et al. In thispaper, we describebriefly the stimulator system and a special apparatus we call the multimomentchair. The stimulator is a development from an earlier design of an implantableperipheral nervestimulator (2) and has features that make it easier to use. The multimomentchair enables us to gather simultaneously isometric joint moments from 14 axesof the legs duringstimulation while the body is fixed in a posture between sitting and fullextension. Such rapid data collection is essential to discover the effects ofmultiple‐root stimulation and its functional possibilities.
An Analysis of the Effect of a Vent Hole on Excess Cement Expressed at the Crown–Abutment Margin for Cement‐Retained Implant Crowns
Authors: Patel Dipan , Invest James C.F. , Tredwin Christopher J. , Setchell Derrick J. , Moles David R.
Published: December 2008

Purpose: The labial margins of anterior implant‐retained crowns are often positioned subgingivally for a superior esthetic appearance. One of the consequences of subgingival margins is the increased risk of leaving excess cement behind following cementation. This can lead to potential problems, including peri‐implant inflammation, soft tissue swelling, soreness, bleeding or suppuration on probing, and bone loss. The purpose of this laboratory study was to investigate the effect of placement, location, and diameter of a vent hole on the amount of cement being expressed at the margin of an anterior implant abutment‐retained crown.

Materials and Methods: Three implant crown copings were fabricated to fit on the same custom abutment. Three vent diameters (0.75, 1.25, and 1.65 mm) and three locations on the palatal surface of the coping (cervico‐palatally, mid‐palatally, inciso‐palatally) were chosen for vent hole placement. For each test, the coping was cemented onto the abutment under standardized conditions. A preweighed thin coating of cement was applied to the fit surface of the coping. The amount of cement expressed at the margin and vent hole was measured by weight and calculated as a proportion of the amount of cement placed in the coping before seating. The procedure was completed 15 times for each variable. The results were statistically analyzed using univariate ANOVA with post hoc Bonferroni‐adjusted independent samples t‐tests.

Results: The presence of a vent hole influenced the proportion of cement expressed at the coping margin (p < 0.05). The location of a vent hole influenced the proportion of cement expressed at the coping margin (p < 0.05), with the exception of the mid‐palatal and inciso‐palatal positioning where there was no significant difference (p= 0.61) between groups. The diameter of the vent hole did not significantly influence the proportion of cement expressed at the coping margin (p= 0.096).

Conclusions: When using anterior cement‐retained implant crowns, the use of a 0.75‐mm mid‐palatal or inciso‐palatal vent hole to minimize the amount of cement expressed at the margin during cementation should be considered.
Impact of Interproximal Groove Placement and Remaining Coronal Tooth Structure on the Fracture Resistance of Endodontically Treated Maxillary Anterior Teeth
Authors: Cho Hyunki , Michalakis Konstantinos X. , Kim Yeongjeong , Hirayama Hiroshi
Published: December 2008

Purpose: This in vitro study investigated the effect of grooves, remaining tooth structure, and their combination on tooth fracture resistance of endodontically treated anterior teeth with cast dowel and cores.

Materials and Methods: Sixty extracted maxillary anterior teeth of similar dimensions were endodontically treated and then randomly divided into three groups of 20 teeth each. The teeth in the first group were cut horizontally at the widest part of their anatomical crowns. Three hundred and sixty degree 1 and 2 mm axial walls for ferrule effect were provided for the teeth in the second and the third groups, respectively. Cast dowel and cores were fabricated for all teeth. Each group was then subdivided in two groups: one with no grooves and another with mesial and distal grooves. Hence, six groups were created as follows: (1) teeth with no remaining coronal tooth structure and no grooves (group A‐control); (2) teeth with no remaining coronal tooth structure, with mesial and distal grooves (group B); (3) teeth with 1 mm remaining coronal tooth structure, with no grooves (group C); (4) teeth with 1 mm remaining coronal tooth structure, with mesial and distal grooves (group D); (5) teeth with 2 mm remaining coronal tooth structure and no grooves (group E); and (6) teeth with 2 mm remaining coronal tooth structure, with mesial and distal grooves (group F). Complete cast crowns were then fabricated for all teeth. A universal testing machine applied controlled loads to the teeth at a crosshead speed of 2.54 mm/min at an angle of 130° to the long axes of the teeth until failure occurred. The loads were applied 2 mm lower than the incisal edges of the specimens. Descriptive statistics, one‐way ANOVA (α= 0.05) and Tukey's honestly significant difference (HSD) tests were used to determine the effect of failure loads among the tested groups (α= 0.05).

Results: The mean failure loads were (N): group A (control), 151.21 ± 38.18; group B, 221.53 ± 107.03; group C, 295.35 ± 81.92; group D, 270.20 ± 76.01; group E, 491.70 ± 180.36; group F, 432.67 ± 193.83. Group E presented the highest failure load and group A (control) the lowest.

Conclusion: The inclusion of interproximal grooves on the cast dowel and cores of endodontically treated anterior teeth with 1–2 mm of remaining coronal tooth structure does not significantly lower the failure threshold.
An Alternative Section Method for Casting and Posterior Laser Welding of Metallic Frameworks for an Implant‐Supported Prosthesis
Authors: De Aguiar Júnior Fábio Afrânio , Tiossi Rodrigo , Rodrigues Renata Cristina Silveira , De Gloria Chiarello Mattos Maria , Ribeiro Ricardo Faria
Published: December 2008

Purpose: The aim of this study was to compare the accuracy of fit of three types of implant‐supported frameworks cast in Ni‐Cr alloy: specifically, a framework cast as one piece compared to frameworks cast separately in sections to the transverse or the diagonal axis, and later laser welded.

Materials and Methods: Three sets of similar implant‐supported frameworks were constructed. The first group of six 3‐unit implant‐supported frameworks were cast as one piece, the second group of six were sectioned in the transverse axis of the pontic region prior to casting, and the last group of six were sectioned in the diagonal axis of the pontic region prior to casting. The sectioned frameworks were positioned in the matrix (10 N·cm torque) and laser welded. To evaluate passive fit, readings were made with an optical microscope with both screws tightened and with only one‐screw tightened. Data were submitted to ANOVA and Tukey–Kramer's test (p < 0.05).

Results: When both screws were tightened, no differences were found between the three groups (p > 0.05). In the single‐screw‐tightened test, with readings made opposite to the tightened side, the group cast as one piece (57.02 ± 33.48 μm) was significantly different (p < 0.05) from the group sectioned diagonally (18.92 ± 4.75 μm) but no different (p > 0.05) from the group transversally sectioned (31.42 ± 20.68 μm). On the tightened side, no significant differences were found between the groups (p > 0.05).

Conclusions: Results of this study showed that casting diagonally sectioned frameworks lowers misfit levels of prosthetic implant‐supported frameworks and also improves the levels of passivity to the same frameworks when compared to structures cast as one piece.
A General Method for Describing Sources of Variance in Clinical Trials, Especially Operator Variance, in Order to Improve Transfer of Research Knowledge to Practice
Authors: Chambers David W. , Leknius Casimir , Reid Laura
Published: December 2008

Purpose: The purpose of this study was to demonstrate how the skill level of the operator and the clinical challenge provided by the patient affect the outcomes of clinical research in ways that may have hidden influences on the applicability of that research to practice. Rigorous research designs that control or eliminate operator or patient factors as sources of variance achieve improved statistical significance for study hypotheses. These procedures, however, mask sources of variance that influence the applicability of the conclusions. There are summary data that can be added to reports of clinical trials to permit potential users of the findings to identify the most important sources of variation and to predict the likely outcomes of adopting products and procedures reported in the literature.

Materials and Methods: Provisional crowns were constructed in a laboratory setting in a fully crossed, random‐factor model with two levels of material (Treatment), two skill levels of students (Operator), and restorations of two levels of difficulty (Patient). The levels of the Treatment, Operator, and Patient factors used in the study were chosen to ensure that the findings from the study could be transferred to practice settings in a predictable fashion. The provisional crowns were scored independently by two raters using the criteria for technique courses in the school where the research was conducted.

Results: The Operator variable accounted for 38% of the variance, followed by Treatment‐by‐Operator interaction (17%), Treatment (17%), and other factors and their combinations in smaller amounts. Regression equations were calculated for each Treatment material that can be used to predict outcomes in various potential transfer applications. It was found that classical analyses for differences between materials (the Treatment variable) would yield inconsistent results under various sampling systems within the parameters of the study.

Conclusions: Operator and Treatment‐by‐Operator interactions appear to be significant and previously underrecognized sources of variance. It is suggested that variance estimates of factors thought to significantly influence the transfer of research findings to practice contexts and evidence of representative sampling across practice contexts be regularly included in reports of clinical trials.
The Effect of Engaging the Screw Access Channel of an Implant Abutment with a Cement‐Retained Restoration
Authors: Naik Supritha , Tredwin Christopher J. , Nesbit Michael , Setchell Derrick J. , Moles David R.
Published: December 2008

Purpose: Factors affecting the retention of fixed prostheses to natural abutments are well understood. In contrast, little is known concerning the factors influencing the retention of fixed prostheses cemented to implant abutments. The purpose of this study was to investigate the effect that extending a casting into the screw access channel of an implant abutment has on the retention when cemented using Temp Bond.

Materials and Methods: Replace Select Straight abutments received set modifications (buccal wall removal at 15°, 22°, and 30°) using a milling machine; controls were unmodified. Two castings were fabricated for each of the modified abutments, one with and one without an extension into the screw access channel. Following cementation with Temp Bond under standardized conditions, the castings were removed from the abutments using an Instron machine, and the peak removal force was recorded.

Results: Extending the casting into the screw access channel significantly (p < 0.001) increased the peak load of removal. Significant differences (p < 0.05) were found between no modification and 30° modification, 15° and 30° modification, and 22° and 30° modification in the groups when the casting extended into the abutment. In the group where the casting did not extend into the abutment, all groups were significantly different (p < 0.001) with the exception of 22° and 30° modification.

Conclusions: The increased load required to remove a casting that extends into the screw access channel of an implant abutment may compensate for loss in retention, which occurs through unfavorable modification of the abutment.
Color Stability Comparison of Silicone Facial Prostheses Following Disinfection
Authors: Goiato Marcelo Coelho , Pesqueira Aldiéris Alves , Santos Daniela Micheline dos , Zavanelli Adriana Cristina , Ribeiro Paula do Prado
Published: December 2008

Purpose: The purpose of this study was to evaluate the color stability of two silicones for use in facial prostheses, under the influence of chemical disinfection and storage time.

Materials and Methods: Twenty‐eight specimens were obtained half made from Silastic MDX 4‐4210 silicone and the other half from Silastic 732 RTV silicone. The specimens were divided into four groups: Silastic 732 RTV and MDX 4‐4210 with disinfection three times a week with Efferdent and Sliastic 732 RTV and MDX 4‐4210 disinfected with neutral soap. Color stability was analyzed by spectrophotometry, immediately and 2 months after making the specimens. After obtaining the results, ANOVA and Tukey test with 1% reliability were used for statistical analysis.

Results: Statistical differences between mean color values were observed. Disinfection with Efferdent did not statistically influence the mean color values.

Conclusion: The factors of storage time and disinfection statistically influenced color stability; disinfection acts as a bleaching agent in silicone materials.
Conceptualizing Corporate Entrepreneurship Strategy
Authors: Ireland R. Duane , Covin Jeffrey G. , Kuratko Donald F.
Published: December 2008

Our knowledge of corporate entrepreneurship (CE) continues to expand. However, this knowledge remains quite fragmented and non–cumulative. Herein, we conceptualize CE strategy as a useful focal point for integrating and synthesizing key elements within CE's intellectual domain. The components of our CE strategy model include (1) the antecedents of CE strategy (i.e., individual entrepreneurial cognitions of the organization's members and external environmental conditions that invite entrepreneurial activity), (2) the elements of CE strategy (i.e., top management's entrepreneurial strategic vision for the firm, organizational architectures that encourage entrepreneurial processes and behavior, and the generic forms of entrepreneurial process that are reflected in entrepreneurial behavior), and (3) the outcomes of CE strategy (i.e., organizational outcomes resulting from entrepreneurial actions, including the development of competitive capability and strategic repositioning). We discuss how our model contributes to the CE literature, distinguish our model from prior models, and identify challenges future CE research should address.
Performance Configurations over Time: Implications for Growth– and Profit–Oriented Strategies
Authors: Steffens Paul , Davidsson Per , Fitzsimmons Jason
Published: December 2008

Strategic entrepreneurship can be described as simultaneous opportunity seeking and advantage seeking. Younger firms are generally more flexible and therefore enjoy “discovery advantages,” whereas established firms tend to be resource rich and more experienced and consequently enjoy “exploitation advantages.” The resulting evolution of the two important performance dimensions, “growth” and “profitability,” by firm age is not well understood. In this article we integrate several theoretical arguments concerning profit–growth relationships to develop a dynamic model of firm development, which suggests different development pathways for young firms. This leads to several unidirectional, competing hypotheses that we examine by studying the profitability–growth configurations of approximately 3,500 small firms and how these configurations evolve over time. We find that for both young and old firms a focus on achieving above–average profitability and then striving for growth is a more likely path toward achieving sustained above–average performance than is first pursuing strong growth in the hope of building profitability later. In line with our hypothesis we find that younger firms are over represented as “Stars” (high on both growth and profitability) and underrepresented as “Poor” (low on both growth and profitability). However, young firms in the “Star” category are also less likely than their older counterparts to maintain that position. Furthermore, our results indicate that young firms are overrepresented not only among “Stars,” but also among growth–orientated firms, regardless of the level of profitability. The findings strongly caution against the blind pursuit of growth for young firms, in favor of a thoughtful analysis of how both growth and profitability might be developed by firms. The results also question whether simultaneous high performance in terms of growth and profitability among young firms usually reflects a successful entrepreneurial strategy. The results can also be interpreted as luck on the part of a subgroup of young firms who indiscriminately pursue growth opportunities with varying profit prospects, and in many cases, the high growth–profit performance will be short lived.
The Effectiveness of Alliances and Acquisitions: The Role of Resource Combination Activities
Authors: Wiklund Johan , Shepherd Dean A.
Published: December 2008

Resource complementarity increases the potential value of alliances and acquisitions, but the extent to which the value potential of an alliance or an acquisition becomes realized depends on the ability of the firm to discover and conduct productive resource combinations. Using a sample of 319 small firms, we separate domestic from international alliances and acquisitions and show that alliances and acquisitions bring limited benefits to firms unless deliberate effort is devoted to resource combination. These findings help resolve conflicts in the resource–based literature concerning the benefits of alliances and acquisitions.
Advancing Strategic Entrepreneurship Research: The Role of Complexity Science in Shifting the Paradigm
Authors: Schindehutte Minet , Morris Michael H.
Published: December 2008

Five areas are identified wherein more development might enhance the current model of strategic entrepreneurship (SE): exploration–exploitation, opportunity, newness, micro–macro interaction, and dynamics. Complexity science is presented as an alternative theoretical lens for addressing these issues, and enhancing the potential of SE in a world characterized by fluctuations, irreversibility, nonlinearity, and instabilities. Using this lens, a rearticulation of SE is proposed that centers on the notion of an opportunity space and a paradigm built around forms, flows, and functions. SE's domain consists of a complex set of phenomena that cannot be neatly bundled according to disciplinary boundaries.
Strategic Entrepreneurship at Universities: Academic Entrepreneurs’ Assessment of Policy Programs
Authors: Patzelt Holger , Shepherd Dean A.
Published: December 2008

In this article we draw on goal–setting theory to analyze how and why entrepreneurs perceive the usefulness of policy programs aimed at facilitating the development of academic ventures. Using a conjoint study and data on 3,136 assessments nested within 98 academic entrepreneurs, we find that access to finance offered by a policy program is central and enhances the entrepreneurs’ perceived benefits of other policy measures such as providing access to nonfinancial resources (networks, business knowledge) and reducing administrative burdens, but diminishes the perceived benefits of offering tax incentives for new ventures. Our results extend the literature on academic entrepreneurship and entrepreneurs’ assessments of government policy measures. For policy makers, our study suggests that the simultaneous launch of policy measures may be perceived by academic entrepreneurs as particularly beneficial for fostering the development of their young ventures.
Renal Artery Fibromuscular Dysplasia Is a Cause of Refractory Hypertension in the Elderly
Authors: Aqel Raed , AlJaroudi Wael W. , Hage Fadi G. , Nanda Navin C.
Published: December 2008

Fibromuscular dysplasia (FMD) is predominantly a disease of younger women, but it can occur and cause refractory hypertension in the elderly. We present here classic angiographic and intravascular ultrasound images of FMD in a 70‐year‐old woman with refractory hypertension. Renal artery FMD should be included in the differential diagnosis of refractory hypertension even in older patients since recognizing and treating this condition will add favorably to the outcome of these patients.
Fetal Age Estimation Using Orbital Measurements: 3D CT‐Scan Study Including the Effects of Trisomy 21
Authors: Pommier Stephan , Adalian Pascal , Gaudart Jean , Panuel Michel , Piercecchi‐Marti Marie‐Dominique , Leonetti Georges
Published: December 2008

Abstract:  This study evaluates a new method of fetal age estimation based on orbital measurement and including the potential trisomy 21 of the fetus. Six orbital and one facial CT‐scan measurements were taken on 71 fetuses ranging from 14 to 41 weeks of gestational age. Forty‐eight fetuses were “normal” and 23 fetuses presented the Down syndrome (trisomy 21). The anatomy/imagery correspondence was evaluated comparing our results to those obtained by direct bone measurements on the same fetuses and revealed no significant differences between the two kinds of measurements. Moreover, a multiple linear stepwise regression was realized to estimate fetal age and showed that the “trisomy 21 parameter” is not conserved in the final determination model. Therefore, we conclude that the good radio‐anatomical correspondence offers an interesting alternative to direct bone measurement (necessitating dissections) and allows a reliable fetal age determination, whatever is the trisomy 21 condition of the fetus.
Estimating Projectile Perpendicular Impact Velocity on Metal Sheet Targets from the Shape of the Target Hole
Authors: Tsach Tsadok , Landau Eliezer , Shor Yaron , Volkov Nikolai , Chaikovsky Alan
Published: December 2008

Abstract:  The correlation between bullet hole shapes in metal and projectile impact velocity was examined. A series of shots were fired from an M‐16A1 assault rifle of 5.56 mm caliber toward a 1‐mm thick metal target. All shots were fired at a perpendicular angle to the metal sheets, and the velocity was measured just before the projectile hit the target. Velocities ranged between 400 and 900 m/sec. From the replica of the shooting hole, a perpendicular plane was created, showing the symmetrical properties of the hole. The best mathematical equation describing the shape of the entrance hole was the exponential function in the form:
image

The empirical equation of the hole defined using the regression method is:
image

This equation describes the general shape of shooting holes created by velocities ranging from 440 to 750 m/sec. From this equation, one can estimate the bullet velocity when it hits the target.
The Application of Remote Sensing for Detecting Mass Graves: An Experimental Animal Case Study from Costa Rica*
Authors: Kalacska Margaret E. , Bell Lynne S. , Arturo Sanchez‐Azofeifa G. , Caelli Terry
Published: December 2008

Abstract: Detection of mass graves utilizing the hyperspectral information in airborne or satellite imagery is an untested application of remote sensing technology. We examined thein situspectral reflectance of an experimental animal mass grave in a tropical moist forest environment and compared it to an identically constructed false grave which was refilled with soil, but contained no cattle carcasses over the course of a 16‐month period. The separability of thein situreflectance spectra was examined with a combination of feature selection and five different nonparametric pattern classifiers. We also scaled up the analysis to examine the spectral signature of the same experimental mass grave from an air‐borne hyperspectral image collected 1 month following burial. Our results indicate that at both scales (in situand airborne), the experimental grave had a spectral signature that was distinct and therefore detectable from the false grave. In addition, we observed that vegetation regeneration was severely inhibited over the mass grave containing cattle carcasses for up to a period of 16 months. This experimental study has demonstrated the real utility of airborne hyperspectral imagery for the detection of a relatively small mass grave (5 m2) within a specific climatic zone. Other climatic zones will require similar actualistic modeling studies, but it is clear that the applications of this technology provide the international community with both an early detection tool and a tool for ongoing monitoring.
Fatal Accident Cause and Conclusion
Authors: Tsach Tsadok , Cohen Aviva , Finegold George
Published: December 2008

Abstract:  The Toolmarks Laboratory prepared a report concerning a traffic accident involving the death of a road workman. The driver of the vehicle that hit the workman claimed that the wheels had failed to respond when turning left at a roundabout. A traffic investigator photographed the rack and pinion assembly of the steering system, which was subsequently removed and brought to the Toolmarks Laboratory. The rack and pinion assembly of the steering system was rebuilt, and examination showed that the system functioned properly. Specifically, the front wheels responded correctly to the steering input. Laboratory photographs of the steering system were taken in two different positions, from the same angles as the investigator’s photographs at the scene of the accident. It was clear that the steering system had not been assembled properly in the garage.
MMPs/TIMPs and inflammatory signalling de‐regulation in human incisional hernia tissues
Authors: Guillen‐Marti Jordi , Diaz Ramon , Quiles Maria T. , Lopez‐Cano Manuel , Vilallonga Ramon , Huguet Pere , Ramon‐y‐Cajal Santiago , Sanchez‐Niubo Albert , Reventós Jaume , Armengol Manel , Arbos Maria A.
Published: December 2008

Background: Incisional hernia is a common and important complication of laparotomies. Epidemiological studies allude to an underlying biological cause, at least in a subset of population. Interest has mainly focused on abnormal collagen metabolism. However, the role played by other determinants of extracellular matrix (ECM) composition is unknown. To date, there are few laboratory studies investigating the importance of biological factors contributing to incisional hernia development. We performed a descriptive tissue‐based analysis to elucidate the possible relevance of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in association with local cytokine induction in human incisional hernia tissues. The expression profiles of MMPs, TIMPs and pro‐inflammatory cytokine signalling were investigated in aponeurosis and skeletal muscle specimens taken intraoperatively from incisional hernia (n= 10) and control (n= 10) patients. Semiquantitative RT‐PCR, zymography and immunoblotting analyses were done. Incisional hernia samples displayed alterations in the microstructure and loss of ECM, as assessed by histological analyses. Moreover, incisional hernia tissues showed increased MMP/TIMP ratios and de‐regulated inflammatory signalling (tumor necrosis factor [TNFA] and interleukin [IL]‐6 tended to increase, whereas aponeurosis TNFA receptors decreased). The changes were tissue‐specific and were detectable at the mRNA and/or protein level. Statistical analyses showed several associations between individual MMPs, TIMPs, interstitial collagens and inflammatory markers. The increment of MMPs in the absence of a counterbalance by TIMPs, together with an ongoing de‐regulated inflammatory signalling, may contribute in inducing a functional defect of the ECM network by post‐translational mechanisms, which may trigger abdominal wall tissue loss and eventual rupture. The notable TIMP3 protein down‐regulation in incisional hernia fascia may be of pathophysiological significance. We conclude that this study may help to pinpoint novel hypotheses of pathogenesis that can lead to a better understanding of the disease and ultimately to improvement in current therapeutic approaches.
Splenic natural killer cell activity in two models of experimental neurodegenerative diseases
Authors: Al‐Falahi Yassin , Sand Kristin L. , Knudsen Eirunn , Damaj Bassam B. , Rolin Johannes , Maghazachi Azzam A.
Published: December 2008

Natural killer (NK) cells are antitumour/anti‐viral effectors and play important roles in shaping the immune system, but their role in neurodegenerative diseases is not clear. Here, we investigated the fate of these cells in two neurodegenerative diseases. In the first model, the activity of NK cells was examined in mice with experimental autoimmune encephalomyelitis (EAE) treated with glatiramer acetate (GA or Copaxone), a drug used to treat EAE in animals and multiple sclerosis in human. The second disease model is twitcher (Galctwi/Galctwi) mice, which represents an authentic model of human Krabbe’s disease. Administration of GA ameliorated EAE in SJL mice corroborated with isolating NK cells that expressed higher killing than cells isolated from vehicle‐dosed animals against immature or mature dendritic cells (DCs). However, this drug showed no effect on the numbers of NK cells or the expression of CD69 molecule. On the other hand, NK cells either disappeared from the spleens or were present in low numbers in the white pulp areas of Galctwi/Galctwi mice, which have increased D‐galactosyl‐β1–1′‐sphingosine (GalSph) levels. Analysis by confocal microscopy shows that NK cells found in the spleens of Galctwi/Galctwi mice were apoptotic. Incubating NK cells in vitro with GalSph induced the apoptosis in these cells, confirming the results of twitcher mice. Our results provide the first evidence showing that amelioration of EAE in mice is corroborated with NK cell lysis of antigen‐presenting DCs, whereas NK cell distribution into the spleen is altered in a devastating lipid disorder corroborated with induction of their apoptosis.