137,819 research outputs found
3-D FEM Analysis of SPT Head Dimension on Recording Characteristics
No full textIn this paper, the effect of the width of write head on behavior of flux and magnetization in the case of continuous track media and discrete track media is investigated using 3-D read/write simulation system. The effect of width of read head on the output is also examined.</p
Comparison of early literacy attitudes of Head Start teachers and the frequency of literacy activities in Wisconsin Head Start classrooms
No full textPlan BHead Start began a school readiness focus in 2000 with an emphasis on accountability when the National Head Start Bureau issued an outcomes framework for all Head Start programs. This was followed up by President Bush’s early childhood initiative, Good Start, Grow Smart. This initiative focused on early literacy and national accountability for all Head Start programs. In response to the national early literacy emphasis, the researcher developed a teacher survey to focus on early literacy attitudes, importance of early literacy activities and frequency of early literacy activities in Head Start classrooms. Demographic information was utilized to compare years of experience and educational level of teachers to attitudes and importance of early literacy in Head Start. Data was collected by sending a survey to 200 Head Start teachers in 56 Head Start agencies throughout the state of Wisconsin in February, 2002. One hundred forty six surveys were returned to the researcher, which yields a return rate of 73%. The Head Start teachers in Wisconsin were asked to participate in the study through their Head Start Director. The Head Start Directors asked teachers in their programs to complete the surveys. If the teachers wished to participate in the study, they completed the survey and returned it in a self-addressed stamped envelope. Level of teacher education and years of teaching experience made a difference in early literacy in Head Start classrooms. As educational level increases, attitudes about early literacy tend to also increase. A statistical significant difference was found at the .05 level between teachers with Associate degrees from those with Bachelor and Master level degrees. Along with early literacy attitudes increasing with educational attainment, the researcher also concluded that teachers feel more skilled teaching early literacy activities as their educational level increases. A significant difference at the .01 level was found between teachers with CDA’s, Associate and Bachelor degrees from those with Master’s degrees. As with level of education, a significant difference was found when comparing early literacy attitudes with years of teaching experience. Teachers with 3-5 years experience scored significantly different at the .05 level from those with 6-10 years of experience. Teachers with 6-10 years of experience scored highest in section two of the survey, attitudes about literacy. Teachers with 2 years or less of teaching experience scored the highest in section three of the survey, importance of teaching early literacy skills and teachers with 11 years or more of teaching experience scored highest on section four of the survey, frequency of literacy activities. This study would be beneficial if repeated one year from now, once the Head Start teachers have been trained in the CIRLCE literacy model and have had a chance to implement literacy strategies in the classroom. Comparing current early literacy attitudes, early literacy importance and frequency early literacy activities may be very different one year from now in Head Start classrooms based on continued training and mentoring support within their programs. The information collected though this survey was very useful in delineating necessary literacy training and technical assistance areas for Head Start teachers. Teachers reported spending the least amount of time on helping students to find letters in words and act out events from stories. These activities are two important literacy aspects for young children to experience. The data also showed teachers with 2 years or less teaching experience reported the highest scores in importance of early literacy skills. It is important for training and technical assistance providers to appreciate teacher differences based on years of teaching experience and level of education
Exploring Annotation of Head Gesture Forms in Spontaneous Human Interaction
No full textKousidis S, Malisz Z, Wagner P, Schlangen D. Exploring Annotation of Head Gesture Forms in Spontaneous Human Interaction. In: Proceedings of the Tilburg Gesture Meeting (TiGeR 2013). 2013
Genetics of hereditary head and neck paragangliomas
No full textItem does not contain fulltextBACKGROUND: The purpose of this study was to give an overview on hereditary syndromes associated with head and neck paragangliomas (HNPGs). METHODS: Our methods were the review and discussion of the pertinent literature. RESULTS: About one third of all patients with HNPGs are carriers of germline mutations. Hereditary HNPGs have been described in association with mutations of 10 different genes. Mutations of the genes succinate dehydrogenase subunit D (SDHD), succinate dehydrogenase complex assembly factor 2 gene (SDHAF2), succinate dehydrogenase subunit C (SDHC), and succinate dehydrogenase subunit B (SDHB) are the cause of paraganglioma syndromes (PGLs) 1, 2, 3, and 4. Succinate dehydrogenase subunit A (SDHA), von Hippel-Lindau (VHL), and transmembrane protein 127 (TMEM127) gene mutations also harbor the risk for HNPG development. HNPGs in patients with rearranged during transfection (RET), neurofibromatosis type 1 (NF1), and MYC-associated factor X (MAX) gene mutations have been described very infrequently. CONCLUSION: All patients with HNPGs should be offered a molecular genetic screening. This screening may usually be restricted to mutations of the genes SDHD, SDHB, and SDHC. Certain clinical parameters can help to set up the order in which those genes should be tested. (c) 2013 Wiley Periodicals, Inc. Head Neck 36: 907-916, 2014
Amplifying head movements with head-mounted displays
No full textThe head-mounted display (HMD) is a popular form of virtual display due to its ability to immerse users visually in virtual environments (VEs). Unfortunately, the user's virtual experience is compromised by the narrow field of view (FOV) it affords, which is less than half that of normal human vision. This paper explores a solution to some of the problems caused by the narrow FOV by amplifying the head movement made by the user when wearing an HMD, so that the view direction changes by a greater amount in the virtual world than it does in the real world Tests conducted on the technique show a significant improvement in performance on a visual search task, and questionnaire data indicate that the altered visual parameters that the user receives may be preferable to those in the baseline condition in which amplification of movement was not implemented. The tests also show that the user cannot interact normally with the VE if corresponding body movements are not amplified to the same degree as head movements, which may limit the implementation's versatility. Although not suitable for every application, the technique shows promise, and alterations to aspects of the implementation could extend its use in the future
Author Self-Citation in the Turkish Otorhinolaryngology Literature
No full textObjective:To evaluate the prevalence and other characteristics of author self-citations in six Turkey-originated general otorhinolaryngology (ORL) journals of Turkish ORL literature.Methods:A total of 970 articles published in six Turkey-originated general ORL journals (ENT Updates, Journal of Ear Nose Throat and Head Neck Surgery, KBB-Forum, Praxis of Otorhinolaryngology, The Turkish Journal of Ear Nose and Throat, and Turkish Archives of Otorhinolaryngology) in 2016-2020 were analyzed for author self-citations. The association between author self-citations and journal types, study types, study topics, country of origin, and compatibility with the topic were also evaluated.Results:There were 265 author self-citations (0.273 per article) which corresponded to 1.36% of all citations. There was no significant difference between the journal types, study topics, and origin of the studies in terms of mean self-citation values per study, whereas case reports had significantly lower self-citations than review and original investigations. There were three citations (1.1%) that were irrelevant to the study topic.Conclusion:To the best of our knowledge, this is the first study that investigated the practice of author self-citation in Turkish ORL literature. Author self-citation rate in the Turkish-originated general ORL journals was found remarkably lower than the medical literature, whereas the self-citations were found compatible with the study topic to a very large extent. Members of the scientific community including authors, readers, and journal editors should be cautious regarding the unethical practices of self-citations
Three‐Dimensional Printing and Its Applications in Otorhinolaryngology–Head and Neck Surgery
No full textObjective
Three-dimensional (3D)-printing technology is being employed in a variety of medical and surgical specialties to improve patient care and advance resident physician training. As the costs of implementing 3D printing have declined, the use of this technology has expanded, especially within surgical specialties. This article explores the types of 3D printing available, highlights the benefits and drawbacks of each methodology, provides examples of how 3D printing has been applied within the field of otolaryngology–head and neck surgery, discusses future innovations, and explores the financial impact of these advances.
Data Sources
Articles were identified from PubMed and Ovid MEDLINE.
Review Methods
PubMed and Ovid Medline were queried for English articles published between 2011 and 2016, including a few articles prior to this time as relevant examples. Search terms included 3-dimensional printing, 3D printing, otolaryngology, additive manufacturing, craniofacial, reconstruction, temporal bone, airway, sinus, cost, and anatomic models.
Conclusions
Three-dimensional printing has been used in recent years in otolaryngology for preoperative planning, education, prostheses, grafting, and reconstruction. Emerging technologies include the printing of tissue scaffolds for the auricle and nose, more realistic training models, and personalized implantable medical devices.
Implications for Practice
After the up-front costs of 3D printing are accounted for, its utilization in surgical models, patient-specific implants, and custom instruments can reduce operating room time and thus decrease costs. Educational and training models provide an opportunity to better visualize anomalies, practice surgical technique, predict problems that might arise, and improve quality by reducing mistakes
A hybrid 3-D reconstruction/registration algorithm for correction of head motion in emission tomography
No full textEven with head restraint, small head movements can occur during data acquisition in emission tomography that are sufficiently large to result in detectable artifacts in the final reconstruction. Direct measurement of motion can be cumbersome and difficult to implement, whereas previous attempts to use the measured projection data for correction have been limited to simple translation orthogonal to the projection. A fully three-dimensional (3-D) algorithm is proposed that estimates the patient orientation based on the projection of motion-corrupted data, with incorporation of motion information within subsequent ordered-subset expectation-maximization subiterations. Preliminary studies have been performed using a digital version of the Hoffman brain phantom. Movement was simulated by constructing a mixed set of projections in discrete positions of the phantom. The algorithm determined the phantom orientation that best matched each constructed projection with its corresponding measured projection. In the case of a simulated single movement in 24 of 64 projections, all misaligned projections were correctly identified. Incorporating data at the determined object orientation resulted in a reduction of mean square difference (MSD) between motion-corrected and motion-free reconstructions, compared to the MSD between uncorrected and motion-free reconstructions, by a factor of 1.9
Contact Stress Analysis of the Native Radial Head and Radial Head Implants
No full textA radial head fracture is a common fracture of the elbow joint most frequently caused by a fall on an outstretched arm. When the radial head is comminuted and reconstruction is not viable, radial head replacement is often the preferred option. There are basically two choices for the radial head implants: monoblock and bipolar. However, little research examining the performance of available radial head implants has been conducted. In this study, a finite element model for the intact elbow joint extracted from CT scans of a cadaveric elbow was created. The constructed FE model was validated with cadaveric experiments using Fuji pressure sensitive film. Then, two different implant models were generated by replacing the radial head with monoblock and bipolar implants. Contact stress and area for each model were calculated and compared under various loading conditions in the contact areas between the radial head and the capitellum of the humerus, and between the radial head and the radial notch of the ulna. A significant difference was found in both maximum contact stress and contact area between the native elbow and two types of implants. Contact stress for monoblock was higher than that for bipolar and vice versa for contact area. FE predictions showed the same pattern as measurements from Fuji analysis did although they overestimated the maximum contact stress and underestimated the contact area compared to the Fuji film experimental results
3-D FEM analysis of the effects of SPT head dimensions on recording in discrete and continuous media
No full textDue to the considerable increase of magnetic recording density, the deviation of the head from the centerline of the track becomes a serious problem for the cross-track interference. In this paper, a three-dimensional read/write simulation system was used to investigate the effect of the width of the write head on the behavior of the flux and magnetization for continuous track medium and discrete track medium. It is shown that the magnetization in a neighboring track of the discrete track medium is smaller than that of the continuous track medium. The output of the read head using the discrete track medium is larger than that of the continuous track medium when a suitable read head width is chosen so that the cross talk is negligible.</p
- …
