Coming to grips with reality: Real grasps, but not pantomimed grasps, resist a simultaneous tilt illusion.

Investigations of grasping real, 3D objects subjected to illusory effects from a pictorial background often choose in-flight grasp aperture as the primary variable to test the hypothesis that the visuomotor system resists the illusion. Here we test an equally important feature of grasps that has received less attention: in-flight grasp orientation. The current study tested a variant of the simultaneous tilt illusion using a mirror-apparatus to manipulate the availability of haptic feedback. Participants performed grasps with haptic feedback (real grasps) and without it (pantomime grasps), reaching for the reflection of a real, 3D bar atop a background grating that induced a 1.1° bias in the perceived orientation of the bar in a separate sample of participants. Analysis of the hand's in-flight grasp orientation at early, late, and end stages of the reach showed that at no point were the real grasps biased by the illusion. In contrast, pantomimed grasps were affected by the illusion at the late and end stages of the reach. At each stage, the effect on the real grasps was significantly weaker than the effect of the illusion as measured by the mean point of subjective equality (PSE) in a two-alternative forced-choice task. In contrast, the effect on the pantomime grasps was statistically indistinguishable from the mean PSE at all three stages of the reach. These findings reinforce the idea that in-flight grasp orientation, like grasp aperture to pictorial illusions of target size, is refractory to pictorial backgrounds that bias perceived orientation.

A Fusion Algorithm for Saccade Eye Movement Enhancement With EOG and Lumped-Element Models.

Electrooculography (EOG) can be used to measure eye movements while the eyelids are open or closed and to assist in the diagnosis of certain eye diseases. However, challenges in biosignal acquisition and processing lead to limited accuracy, limited resolution (both temporal and spatial), as well as difficulties in reducing noise and detecting artifacts. Methods such as finite impulse response, wavelet transforms, and averaging filters have been used to denoise and enhance EOG measurements. However, these filters are not specifically designed to detect saccades, and so key features (e.g., saccade amplitude) can be over-filtered and distorted as a consequence of the filtering process. Here we present a model-based fusion technique to enhance saccade features within noisy and raw EOG signals. Specifically, we focus on Westheimer (WH) and linear reciprocal (LR) eye models with a Kalman filter. EOG signals were measured using OpenBCI's Cyton Board (at 250 Hz), and these measurements were compared with a state-of-the-art EyeLink 1000 (EL; 250 Hz) eye tracker. On average, the LR model-based KF produced a 47% improvement of measurement accuracy over the bandpass filters. Thus, we conclude that our LR model-based KF outperforms standard bandpass filtering techniques in reducing noise, eliminating artifacts, and restoring missing features of saccade signatures present within EOG signals.

Input From Practice: Reshaping Dental Education for Integrated Patient Care.

Among the primary challenges in advancing the practice of integrated primary dental and medical health care is the appropriate educational and clinical preparation of a dental workforce that can function and flourish within integrated care environments. Most dental schools teach to traditional concepts and standards of dental care delivery which may be inconsistent with those of integrated care and could deter the entry and retention of graduates in contemporary, non-traditional practice models. To better understand how the dental school curriculum should be modified to accommodate integrative care models, a number of patient care organizations actively engaged in dental-medical integration were site visited to gain insight into the readiness of newer graduates, with emphasis on the US DMD/DDS graduate, to function in integrated practice. Leaders, practicing clinicians and staff were interviewed and common observations and themes were documented. This manuscript will focus on those educational components that integrated care organizations identify as absent or inadequate in current dentist education which must be addressed to meet the unique expectations and requirements of integrated patient care. These changes appear pivotal in the preparation of a dental clinician workforce that is respectful and receptive to new practice concepts, adaptative to new practice models, and competent in new care delivery systems.

Evaluation of an Experiential and Self-Learning Approach to Teaching Evidence-Based Decision Making to Dental Students.

The aim of this study was to evaluate the impact on predoctoral dental students of an experiential and self-learning pedagogical approach to evidence-based decision making. Dental students at one U.S. dental school in 2014 and 2015 participated in an evidence-based decision making course that consisted of minimal lecturing, learning through assigned readings and open-book online quizzes, and individual assignments to reach an evidence-based decision on a clinically relevant question. Before and after the course, each cohort completed a validated survey assessing students' knowledge, attitudes, access of evidence, and confidence related to evidence-based practice. In 2014, of 43 students enrolled in the course, all 43 (100%) completed the pre-course survey, and 33 (77%) completed the post-course survey. In 2015, of 35 students enrolled in the course, all 35 (100%) completed the pre-course survey, and 34 (97%) completed the post-course survey. Of those, the identifier codes for 23 students in 2014 and 25 students in 2015 matched for the pre-course and post-course surveys, allowing direct comparisons. Both cohorts of students showed a significant increase in knowledge regarding critical appraisal of the literature from the pre-course survey results to after the course (p<0.001). Students' reported frequency of accessing evidence from various sources also significantly increased from before to after the course for both cohorts (p<0.01). Students' confidence in evaluating various aspects of a published research report also increased significantly from before to after the course for both cohorts (p<0.001). However, no consistent change was found in students' attitudes about evidence-based practice. In this study, an experiential and self-learning approach to teaching evidence-based decision making in the classroom appeared to be successful in improving students' knowledge, use of evidence, and confidence in critical appraisal skills, though it did not have a consistent impact on their attitudes about evidence-based practice.

Effects of blood-flow restriction on biomarkers of myogenesis in response to resistance exercise.

We investigated the acute myogenic response to resistance exercise with and without blood-flow restriction (BFR). Six men and women (age, 22 ± 1 years) performed unilateral knee extensions at 40% of 1-repetition maximum with or without (CNTRL) BFR applied via pressure cuff inflated to 220 mm Hg. Muscle biopsies were collected at 4 h and 24 h postexercise. Addition of BFR increased myoD and c-Met messenger RNA expression relative to CNTRL. Expression of hepatocyte growth factor protein was significantly higher following CNTRL.

Active muscle regeneration following eccentric contraction-induced injury is similar between healthy young and older adults.

Repair of skeletal muscle after injury is a key aspect of maintaining proper musculoskeletal function. Studies have suggested that regenerative processes, including myogenesis and angiogenesis, are impaired during advanced age, but evidence from humans is limited. This study aimed to compare active muscle regeneration between healthy young and older adults. We evaluated changes in clinical, biochemical, and immunohistochemical indices of muscle regeneration at precisely 2 (T2) and 7 (T3) days following acute muscle injury. Men and women, aged 18-30 and ≥70 years, matched for gender and body mass index, performed 150 unilateral, eccentric contractions of the plantar flexors at 110% of one repetition maximum. Data were analyzed using analysis of covariance, adjusted for gender, habitual physical activity, and baseline level of the outcome. A total of 30 young (n = 15; 22.5 ± 3.7 yr) and older (n = 15; 75.8 ± 5.0 yr) adults completed the study. Following muscle injury, force production declined 16% and 14% in young and older adults, respectively, by T2 and in each group, returned to 93% of baseline strength by T3. Despite modest differences in the pattern of response, postinjury changes in intramuscular concentrations of myogenic growth factors and number of myonuclear (4',6-diamidino-2-phenylindole+ and paired box 7+) cells were largely similar between groups. Likewise, postinjury changes in serum and intramuscular indices of inflammation (e.g., TNF-α and monocyte chemoattractant protein-1) and angiogenesis (e.g., VEGF and kinase insert domain receptor) did not differ significantly between groups. These findings suggest that declines in physical activity and increased co-morbidity may contribute to age-related impairments in active muscle regeneration rather than aging per se.

Blood flow restriction enhances post-resistance exercise angiogenic gene expression.

PURPOSE: The objective of this study is to evaluate the effects of blood flow restriction (BFR) on muscle oxygenation during low-intensity resistance exercise as well as postexercise expression of molecules related to physiological angiogenesis. METHODS: Using a randomized cross-over design, six apparently healthy young adults (22 ± 1 yr) performed 120 unilateral knee extensions at 40% of 1 repetition maximum with and without BFR (CNTRL). Near-infrared spectroscopy was used to measure oxygenation of the vastus lateralis during exercise. Serum and muscle expression of Post-Resistance vascular endothelial growth factor (VEGF) were determined preexercise, 4 h postexercise, and 24 h postexercise. Transcript (mRNA) expression of VEGF and other angiogenic genes was also determined. RESULTS: BFR increased muscle hemoglobin (Hb) concentrations during exercise (14.4 ± 1.6 vs. 0.9 ± 1.6, P = 0.002), driven largely by an increase in deoxygenated Hb (11.0 ± 2.5 vs. 0.5 ± 1.1, P = 0.030). BFR also increased (P < 0.05) transcript expression of VEGF, VEGF-R2, hypoxia-inducible factor 1 alpha, inducible nitric oxide synthase (NOS), and neuronal NOS. The most dramatic change in response to BFR was an increase in VEGF mRNA at 4 h postexercise (4.1 ± 0.6 vs. 0.6 ± 0.2-fold change, P = 0.028). Compared with control, transcript expression of endothelial NOS, serum VEGF, or muscle protein expression of VEGF was not altered in response to BFR (P > 0.05). CONCLUSION: Acute BFR increases postexercise expression of mRNA related to skeletal muscle angiogenesis, plausibly in response to changes in muscle Hb concentrations.

Revisiting the National Board Dental Examination.

The National Board Dental Examination (NBDE) assists state boards of dentistry in determining the qualifications of dentists for initial licensure. This article explains the purpose and rationale for the policies and procedures that guide the NBDE. These examinations have been used for a number of purposes well beyond the assessment of the knowledge and abilities for entry-level dental practice. The article explores the uses and misuses of the National Boards and the relationship between dental licensure examinations and dental curricula. For National Board examinations to remain current and relevant, they must be consistent with standards and best practices for high-stakes testing, and they must focus on competencies and critical thinking skills essential for future practice. The National Board examinations have the potential to stimulate and support curricular reform through collaborative efforts of educators and practitioners who support the test development and standard-setting processes of the examinations.

Realigning the National Board Dental Examination with contemporary dental education and practice.

Although the National Board Dental Examination (NBDE) was developed for the purpose of supporting the dental licensure process, it can have significant influence on dental school curricula. Efforts to revise and enhance dental curricula, of necessity, must engage stakeholder communities and promote an assessment process that is both valid and relevant to contemporary dental practice. The NBDE uses a systematic and objective process for test development that involves content experts from dental education and practice. This process could be enhanced by reconsidering the types of individuals who should participate in test construction, reconfiguring the groups involved in the process, augmenting training and development of test constructors, and updating the principles and documents that define the competencies and foundational knowledge required for contemporary dental practice. In addition, there is a need for ongoing research and development to explore new testing strategies that stress understanding and the ability to apply information in a problem-solving context. Finally, examinations could be enhanced with a broader array of high-quality supporting case materials through a more structured collaborative arrangement between dental schools and the National Board testing program.

Comparison of 2 clinical techniques for treatment of gingival recession.

BACKGROUND: In early case studies, use of a collagen barrier as a guided tissue regeneration (GTR) material has shown particular promise in procedures aimed at root coverage. The similarities between collagen membrane and subepithelial connective tissue graft (SCTG) have made collagen membrane an attractive and a possible alternative material for root coverage. The purpose of this randomized clinical trial was to compare these 2 techniques, SCTG versus a GTR-based procedure (GTRC), for root coverage/recession treatment. METHODS: Sixteen patients with bilateral Miller's Class I or II (gingival recession > or = 3.0 mm) recession defects were treated either with SCTG or GTRC using a newly designed collagen membrane. Clinical parameters monitored included recession depth (RD), clinical attachment level (CAL), probing depth (PD), width of keratinized gingiva (KG), attached gingiva (AG), and recession width (RW), each measured at the mid-buccal area to the nearest 0.5 mm. Measurements were taken at baseline and 6 months. A standard mucogingival surgical procedure was performed. Data were reported as means +/- SD and were analyzed using the paired t test for univariate analysis and restricted/residual maximal likelihood (REML)-based mixed effect model for multivariate analysis. RESULTS: No statistically significant differences were observed in RD, CAL, KG, and AG between test and control groups at either time period. However, SCTG showed significantly more residual PD and more RW gain when compared to GTRC at 6 months. Both treatments resulted in a statistically significant (P < 0.05) reduction of recession defects (2.5 mm and 2.8 mm), gain of CAL (2.8 mm and 2.3 mm), reduction of RW (1.9 mm and 2.7 mm), and increase of KG (0.7 mm and 1.1 mm) and AG (0.7 mm and 0.5 mm) for GTRC and SCTG, respectively, when comparing 6-month data to baseline. Mean root coverage of 73% (collagen membrane) and 84% (subepithelial connective tissue graft) was achieved. CONCLUSIONS: The 2 techniques are clinically comparable. Use of a modified collagen membrane to attain root coverage may alleviate the need for donor site procurement of connective tissue.

Immortalized cementoblasts and periodontal ligament cells in culture.

Cementum, a mineralized tissue lining the surface of the tooth root, is required for formation of a functional periodontal ligament attachment during development. Additionally, during regeneration of tissues after disease, cementum is thought to play a critical role in the reparative process. Research efforts aimed toward understanding mechanisms involved in periodontal development and regeneration, and in particular the formation of root cementum, have been hampered by an inability to isolate and culture cells involved in cementum production, i.e., cementoblasts. Using classical techniques for osteoblast isolation, immortalized, heterogeneous cementoblast/periodontal ligament cell (CM/PDL) populations were established from cells lining the tooth root surface of: 1) CD-1 mice, where cells were immortalized using SV40, or 2) H-2KbtsA58 "immorto" mice, where cells containing an immortalizing transgene were removed and cultured. CM/PDL populations were derived from tissues adherent to developing tooth root surfaces, while tissues adherent to the surrounding alveolar bone were specifically excluded from the population. Immortalized CM/PDL cells were characterized to ensure their phenotype reflected that previously demonstrated in situ and in primary, nonimmortalized cultures. Proteins/mRNAs associated with bone/cementum and known to be expressed by root lining cementoblasts, but not by PDL cells, in situ, e.g., bone sialoprotein, osteopontin, and osteocalcin, were expressed by cells within the immortalized populations. Furthermore, CM/PDL cells, in vitro, attached to bone sialoprotein in an arginine-glycineaspartic acid (RGD)-dependent manner, promoted mineral nodule formation and exhibited a PTH/PTHrP-mediated cAMP response. These immortalized heterogeneous populations, containing both CM and PDL cells, provide a unique opportunity to study cells involved in cementogenesis and to enhance our knowledge of the mechanisms controlling development, maintenance, and regeneration of periodontal tissues.