672 research outputs found

    Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

    Get PDF
    Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG

    Radiation Doses of Common Dental Radiographic Examinations: A Review

    Get PDF
    Čak i male doze zračenja mogu biti biološki štetne zbog stohastičkih učinaka, kao što je, na primjer, nastanak karcinoma koji može potaknuti primljena količina radijacije. Efektivne doze radijacije variraju između 4 i16 μSv kod ortopanskih snimki, pa od 33 do 150 μSv kada se pojedinačno snima svaki zub u usnoj šupljini, naravno ovisno o primijenjenoj tehnici. Efektivne doze primljene kod CT-a s cone-beamom znatno su različite, a ovise o opremi koja se koristi, no općenito su veće nego kod ortopanskih snimki, a manje nego kod multidetektorskih CT-a. Načini na koje se smanjuje doza tijekom stomatoloških rendgenskih pretraga jesu ponajprije kriteriji je li uopće potrebna rtg snimka, zatim primjena receptora koji brzo reagiraju i bolja izoštrenost suženoga snopa, posebice kod djece.Even low doses of radiation have the potential to cause biologic harm by way of stochastic effects, those, like carcinogenesis, whose probability of occurrence is dependent on radiation dose. Effective radiation doses range from 4-16 μSv for panoramic radiographs to 33-150 μSv for a full-mouth intraoral series, depending on exact technique used. Effective doses from cone-beam CT vary significantly, depending on the specifi c equipment used, but in general are much higher than for panoramic radiographs but less than for multidetector CT. Methods to reduce the dose from dental x-ray examinations include the use of selection criteria to determine whether a radiograph is needed, the use of fast image receptors, and increased beam collimation, particularly for children

    Validation of a specific selection criterion for dental periapical radiography

    Full text link
    It has been recommended that the prescription of dental radiographic examinations be based on a series of selection criteria. This study evaluated the usefulness of the presence of a large or deep restoration as an indicator for the need for a radiographic examination. Patients in need of routine examinations were questioned regarding pain in restored teeth. The radiographs of 2269 restored teeth in 209 patients were evaluated for depth of restoration and presence or absence of periapical pathosis. Another 1306 nonrestored teeth in 100 patients were evaluated similarly. There was an association between pain and periapical pathosis and between depth of restoration and periapical pathosis (p < 0.001 in each case). Radiographic yield for positive apical findings was low in restored teeth, especially when the restoration was shallow. The radiographic yield may be increased if other factors such as pain or integrity of the restoration are used to help make the decision regarding the need for radiographs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30914/1/0000583.pd

    Effect of Ridge Morphology on Guided Bone Regeneration Outcome: Conventional Tomographic Study

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141560/1/jper1231.pd

    Book Reviews

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66290/1/j.1752-7325.1985.tb01140.x.pd

    Intervention and Outcomes of Children in Different Types of Listening and Spoken Language Programs

    Get PDF
    This study explores the impact of the type and dosage of listening and spoken language (LSL) services on speech and language outcomes in children with cochlear implants or hearing aids in two LSL programs. Identical demographic variables were collected across the two programs for use in the statistical analyses. Speech and language outcomes were examined at ages 3 and 5 using standardized test measures. At age 3, significant differences in LSL outcomes existed between programs for children using cochlear implants but not for children using binaural hearing aids. However, at age five, outcomes were similar between the different LSL programs for children with hearing aids and cochlear implants. Total hours of LSL services do not serve as a predictor of LSL outcomes at five years of age. However, early identification of hearing loss, early amplification, and early enrollment in a LSL program were highly influential factors affecting LSL outcomes at three and five years of age. Non-verbal IQ and maternal education levels also influence LSL outcomes. Children with earlier access to hearing technology and LSL intervention may need fewer hours of LSL services to achieve age-appropriate LSL outcomes. Overall, both of these LSL programs supported age-appropriate speech and language outcomes by age 5

    Use of traditional knowledge by the United States Bureau of Ocean Energy Management to support resource management

    Get PDF
    Professionals who collect and use traditional knowledge to support resource management decisions often are preoccupied with concerns over how and if traditional knowledge should be integrated with science. To move beyond the integration dilemma, we treat traditional knowledge and science as distinct and complementary knowledge systems. We focus on applying traditional knowledge within the decision-making process. We present succinct examples of how the Bureau of Ocean Energy Management has used traditional knowledge in decision making in the North Slope Borough, Alaska: 1) using traditional knowledge in designing, planning, and conducting scientific research; 2) applying information from both knowledge systems at the earliest opportunity in the process; 3) using traditional knowledge in environmental impacts assessment; 4) consulting with indigenous leaders at key decision points; and 5) applying traditional knowledge at a programmatic decision level. Clearly articulating, early in the process, how best to use traditional knowledge and science can allow for more complete and inclusive use of available and pertinent information

    Reliability and validity of the AGREE instrument used by physical therapists in assessment of clinical practice guidelines

    Get PDF
    BACKGROUND: The AGREE instrument has been validated for evaluating Clinical Practice Guidelines (CPG) pertaining to medical care. This study evaluated the reliability and validity of physical therapists using the AGREE to assess quality of CPGs relevant to physical therapy practice. METHODS: A total of 69 physical therapists participated and were classified as generalists, specialist or researchers. Pairs of appraisers within each category evaluated independently, a set of 6 CPG selected at random from a pool of 55 CPGs. RESULTS: Reliability between pairs of appraisers indicated low to high reliability depending on the domain and number of appraisers (0.17–0.81 for single appraiser; 0.30–0.96 when score averaged across a pair of appraisers). The highest reliability was achieved for Rigour of Development, which exceeded ICC> 0.79, if scores from pairs of appraisers were pooled. Adding more than 3 appraisers did not consistently improve reliability. Appraiser type did not determine reliability scores. End-users, including study participants and a separate sample of 102 physical therapy students, found the AGREE useful to guide critical appraisal. The construct validity of the AGREE was supported in that expected differences on Rigour of Development domains were observed between expert panels versus those with no/uncertain expertise (differences of 10–21% p = 0.09–0.001). Factor analysis with varimax rotation, produced a 4-factor solution that was similar, although not in exact agreement with the AGREE Domains. Validity was also supported by the correlation observed (Kendall-tao = 0.69) between Overall Assessment and the Rigour of Development domain. CONCLUSION: These findings suggest that the AGREE instrument is reliable and valid when used by physiotherapists to assess the quality of CPG pertaining to physical therapy health services

    The First New Zealanders? An Alternative Interpretation of Stable Isotope Data from Wairau Bar, New Zealand.

    Get PDF
    PLOS ONE Volume 8 includes an article “The First New Zealanders: Patterns of Diet and Mobility Revealed through Isotope Analysis”. The paper proposes that burial groups within the settlement phase site of Wairau Bar differ in terms of dietary stable isotopes and 87Sr/86Sr. The authors argue this difference is probably due to one group being a founding population while the other burials are later. Here we review the work of Kinaston et al. and present an alternative analysis and interpretation of the isotopic data. Treating the isotope data independently from cultural and biological factors we find that sex best explains dietary variation. Our reassessment of 87Sr/86Sr confirms the authors original finding of high mobility of early New Zealanders but suggests a larger range of individuals should be considered ‘non-local’ on current evidence
    corecore