The time course of stimulus-specific perceptual learning.

Practice on perceptual tasks can lead to long-lasting, stimulus-specific improvements. Rapid stimulus-specific learning, assessed 24 hours after practice, has been found with just 105 practice trials in a face identification task. However, a much longer time course for stimulus-specific learning has been found in other tasks. Here, we examined 1) whether rapid stimulus-specific learning occurs for unfamiliar, non-face stimuli in a texture identification task; 2) the effects of varying practice across a range from just 21 trials up to 840 trials; and 3) if rapid, stimulus-specific learning persists over a 1-week, as well as a 1-day, interval. Observers performed a texture identification task in two sessions separated by one day (Experiment 1) or 1 week (Experiment 2). Observers received varying amounts of practice (21, 63, 105, or 840 training trials) in session 1 and completed 840 trials in session 2. In session 2, one-half of the observers in each group performed the task with the same textures as in session 1, and one-half switched to novel textures (same vs. novel conditions). In both experiments we found that stimulus-specific learning - defined as the difference in response accuracy in the same and novel conditions - increased as a linear function of the log number of session 1 training trials and was statistically significant after approximately 100 training trials. The effects of stimulus novelty did not differ across experiments. These results support the idea that stimulus-specific learning in our task arises gradually and continuously through practice, perhaps concurrently with general learning.

Improving estimation of water soil erosion by introducing lithological formation for environmental remediation.

Soil erosion is a serious and complex environmental problem worldwide, especially in the centre west of Tunisia. Whereas the construction of hill reservoirs is part of the soil and water conservation strategy, many of these have a siltation problem. Dhkekira is one of the smallest watersheds in central Tunisia whose most lithological formation consists of materials that are quite susceptible to water erosion. Due to the lack of low-scale lithological data, digital IR aerial photos with 2 m spatial resolution were considered. A semi-automatic classification of aerial photos, based on the image's textural indices is developed. The lithologic map extracted from aerial photos was used as input for ANSWERS-2000 water erosion model. Results obtained indicate first, with the semi-automatic classification of the mean and standard deviation of the thumbnail histograms that image output could help to give an idea about the existence of some surface lithological formation. The model applied to Dhkekira watershed showed that the spatial difference in water erosion was not caused only by land cover and slope, but also by lithological formation. The percentage of each lithological formation in sediment yield at the Dhkekira hill reservoir was estimated to be 69% sediment yield from Pleistocene and 19.7% from Lutetian-Priabonian.

Risk Stratification of Sentinel Node Metastasis Disease Burden and Phenotype in Stage III Melanoma Patients.

BACKGROUND: Currently, all patients with American Joint Committee on Cancer (AJCC) pT2b-pT4b melanomas and a positive sentinel node biopsy are now considered for adjuvant systemic therapy without consideration of the burden of disease in the metastatic nodes. METHODS: This was a retrospective cohort analysis of 1377 pT1-pT4b melanoma patients treated at an academic cancer center. Standard variables regarding patient, primary tumor, and sentinel node characteristics, in addition to sentinel node metastasis maximum tumor deposit size (MTDS) in millimeters and extracapsular spread (ECS) status, were analyzed for predicting disease-specific survival (DSS). RESULTS: The incidence of SN+ was 17.3% (238/1377) and ECS was 10.5% (25/238). Increasing AJCC N stage was associated with worse DSS. There was no difference in DSS between the IIIB and IIIC groups. Subgroup analyses showed that the optimal MTDS cut-point was 0.7 mm for the pT1b-pT4a SN+ subgroups, but there was no cut-point for the pT4b SN+ subgroup. Patients with MTDS <0.7 mm and no ECS had similar survival outcomes as the N0 patients with the same T stage. Nodal risk categories were developed using the 0.7 mm MTDS cut-point and ECS status. The incidence of low-risk disease, according to the new nodal risk model, was 22.3% (53/238) in the stage III cohort, with 49% (26/53) in the pT2b-pT3a and pT3b-pT4a subgroups and none in the pT4b subgroup. Similar outcomes were observed for overall and distant metastasis-free survival. CONCLUSION: We propose a more granular classification system, based on tumor burden and ECS status in the sentinel node, that identifies low-risk patients in the AJCC IIIB and IIIC subgroups who may otherwise be observed.

Disruption of Positional Encoding at Small Separations in the Amblyopic Periphery.

Purpose: Positional judgments in amblyopia are impaired more at the center of the visual field than in the periphery. However, the effects of visual field position frequently are confounded with stimulus separation. The purpose of this experiment was to parse the effects of stimulus separation and eccentricity on the positional deficit in amblyopia. Methods: Subjects adjusted the positions of stimuli of varying separations on isoeccentric arcs. The task was simultaneous bisection and alignment of broadband, high-contrast, uncrowded targets with reference to central fixation. Ten strabismic amblyopes and five normally sighted controls performed the task dichoptically; a subset of amblyopes performed the task monocularly with the amblyopic eye. Spread (inverse of precision) and bias were measured at multiple visual field locations comprising two to three separation \(\times\) four eccentricity conditions in each visual field quadrant. Results: In normal controls, both spread and bias increased with eccentricity, and spread (but not bias) increased linearly with separation until 7° eccentricity. Strabismic amblyopes showed a different profile: spread and bias were higher at small separations at all eccentricities, such that performance showed a quadratic trend against separation. Thus, at each eccentricity, the difference in performance between groups was largest at the smallest separation. Conclusions: These results are consistent with disruptions in Weber mechanisms of positional encoding in strabismic amblyopia, and indicate that binocular stimulation by proximal targets produces a loss of spatial precision well beyond the fovea.

Can a Patient use an App at Home to Measure Knee Range of Motion? Utilizing a Mobile App, Curovate, to Improve Access and Adherence to Knee Range of Motion Measurements.

Introduction: Knee range of motion is a critical measure of progress after knee injury and knee surgery. However, many patients do not understand the importance of knee range of motion and most do not have a way to self-monitor their knee range of motion at home. The patient being able to measure their own range of motion can provide improved access to this critical health metric, and could improve adherence with their daily knee range of motion exercises. The purpose of this technical report is to determine if a mobile app, Curovate, can provide reliable measures of knee range of motion compared to standard goniometric measurements. Procedures: There were four positions of knee flexion and four positions of knee extension each measured twice with a standard goniometer and four different mobile devices with the app Curovate. The reliability and validity of the Curovate app was tested across mobile devices and operating systems and compare to goniometric knee range of motion measurements. A total of 80 measurements were taken. All testing was completed on a healthy 23-year-old male with no knee pathology. Results: A strong positive correlation, Pearson's r > = 0.9985, for all positions of knee flexion and extension across all four mobile devices as well as each mobile device compared to standard goniometric measurements. Conclusions: This article presents a unique method for patients to measure their knee range of motion using the mobile app Curovate. Overall, the mobile app, Curovate, was found to have a strong positive correlation across four mobile devices with varying operating systems and compared to goniometric measurements. Level of evidence: 4.

A comparison of household food insecurity rates in Newfoundland and Labrador in 2011-2012 and 2017-2018.

OBJECTIVES: The prevalence of household food insecurity in Newfoundland and Labrador (NL) fell sharply between 2007 and 2011, but it appears to have risen since then. Our objective was to compare the prevalence of food insecurity between 2011-2012 and 2017-2018 in relation to population socio-demographic characteristics. METHODS: Our analytic sample comprised all NL households in the Canadian Community Health Survey (CCHS) cycles 2011-2012 and 2017-2018, n = 6800. We stratified the prevalence of household food insecurity for each cycle by socio-demographic characteristics and applied multivariable logistic regression models to determine food insecurity odds in 2017-2018 compared with 2011-2012 after controlling for socio-demographic covariates. Interactions of covariates with survey cycle were tested and models stratified when warranted. RESULTS: The prevalence of food insecurity rose from 12.0% (95% CI 10.5, 13.6) in 2011-2012 to 14.7% (95% CI 13.1, 16.6) in 2017-2018. After adjusting for household socio-demographic variables, the odds of food insecurity was 1.49 (95% CI 1.27, 1.75) in 2017-2018. The prevalence of food insecurity had increased significantly among unattached individuals, renters, households with low educational attainment, and households with income above the Low Income Measure, with concomitant increases in the contribution of these groups to the total provincial prevalence of food insecurity in 2017-2018 compared with that in 2011-2012. CONCLUSION: The odds of food insecurity among NL households increased significantly from 2011-2012 to 2017-2018. Given the serious negative health implications of household food insecurity, the province should draw on the lessons from its earlier success in food insecurity reduction to reverse the current trend.

RéSUMé: OBJECTIFS: La prévalence de l'insécurité alimentaire des ménages à Terre-Neuve-et-Labrador (T.-N.-L.) a connu une forte baisse entre 2007 et 2011, mais depuis, elle semble avoir augmenté. Nous avons cherché à comparer la prévalence de l'insécurité alimentaire entre 2011-2012 et 2017-2018 en lien avec le profil sociodémographique de la population. MéTHODE: Notre échantillon d'analyse comprenait tous les ménages de T.-N.-L. inclus dans les cycles 2011-2012 et 2017-2018 de l'Enquête sur la santé dans les collectivités canadiennes (ESCC), soit n = 6 800. Nous avons stratifié la prévalence de l'insécurité alimentaire des ménages pour chaque cycle selon le profil sociodémographique et appliqué des modèles de régression logistique multivariée pour déterminer la probabilité d'insécurité alimentaire en 2017-2018 comparativement à 2011-2012 compte tenu des covariables sociodémographiques. Nous avons testé les interactions des covariables avec les cycles de l'enquête et stratifié les modèles au besoin. RéSULTATS: La prévalence de l'insécurité alimentaire a augmenté, passant de 12 % (IC de 95 % 10,5, 13,6) en 2011-2012 à 14,7 % (IC de 95 % 13,1, 16,6) en 2017-2018. Après l'apport d'ajustements pour tenir compte des variables sociodémographiques des ménages, la probabilité d'insécurité alimentaire était de 1,49 (IC de 95 % 1,27, 1,75) en 2017-2018. La prévalence de l'insécurité alimentaire avait augmenté de façon significative chez les personnes seules, les locataires, les ménages ayant un faible niveau d'instruction et les ménages ayant un revenu supérieur à la mesure de faible revenu, avec des augmentations concomitantes de l'apport de ces groupes à la prévalence provinciale totale de l'insécurité alimentaire en 2017-2018 par rapport à 2011-2012. CONCLUSION: La probabilité d'insécurité alimentaire des ménages de T.-N.-L. a augmenté de façon significative entre 2011-2012 et 2017-2018. Étant donné les graves conséquences négatives de l'insécurité alimentaire des ménages pour la santé, la province devrait tirer des leçons de son succès antérieur dans la réduction de l'insécurité alimentaire pour inverser la tendance actuelle.

An expert advantage in detecting unfamiliar visual signals in noise.

Diagnostic radiologists are experts in discriminating and classifying medical images for clinically significant anomalies. Does their perceptual expertise confer an advantage in unfamiliar visual tasks? Here, this issue was investigated by comparing the performance of 10 radiologists and 2 groups of novices on the ability to detect novel visual signals: band-limited textures in noise. Observers performed a yes/no detection task in which texture spatial frequency and external noise levels were varied. The task was performed on two consecutive days. Contrast thresholds and response bias were measured. Contrast thresholds of radiologists were superior to the control groups in all stimulus conditions on both days. Performance improved by an equivalent amount for all groups across days. Response bias differed consistently across stimulus conditions and days but not across groups. The difference in thresholds between the radiologists and control groups suggests that experience in diagnostic medical imaging produces perceptual skills that that transfer beyond the trained domain.

Perceptual learning of detection of textures in noise.

We examined whether the effects of practice on visual detection are stimulus specific and whether practice alters response bias. Eighty-four subjects performed yes-no detection of band-limited noise patterns (textures) in two levels of external noise, on two consecutive days. On day 2, one-half of the observers switched to novel textures. Texture contrast was varied on signal-present trials using the method of constant stimuli. The signal was present on 50% of the trials. We measured d', detection thresholds, and two measures of response criterion: a global criterion that was based on sensitivity at all signal levels (Jones et al., 2015) and a local criterion computed at a hit rate of 70% or 80% (Wenger & Rasche, 2006). Performance improved for both groups on day 2, indicating that improvement transferred to novel textures. Increases in d' were associated with a decrease in false alarms across days. The global criterion became less liberal and became more optimal (i.e., less biased) with practice; however, this effect was small and was not statistically significant in all conditions. The local criterion measure also became slightly less liberal with practice in most conditions, becoming more or less optimal depending on the hit rate at which it was computed. Overall, the effects of practice on sensitivity in a visual detection task generalized to novel patterns. In addition, we found that practice had relatively small effects on response criterion, and the precise effects on response bias differed between global and local measures of criterion.

Crown Lengthening surgery: An overview.

The term 'crown lengthening surgery' refers to a variety of techniques which aim to expose a greater amount of tooth structure around a tooth or group of teeth. The decision to treat and which technique to use will depend upon: the underlying aetiology; a thorough history and examination; results of any supporting investigations and a clear understanding of the intended outcome of treatment. This paper aims to provide an overview of crown lengthening surgery and is illustrated with clinical cases.

Factors affecting decision making at reassessment of periodontitis. Part 4: treatment options for residual periodontal pockets.

This paper is the final in a four-part series outlining treatment planning at periodontal reassessment. The first article (part 1) focused on the information that should be gathered at the reassessment appointment. Parts 2 and 3 discussed systemic and local factors that can relate to residual periodontal probing depths. Treatment can involve a range of non-surgical and surgical approaches. A variety of general, practical and local site factors can affect the choice of one option over another in choosing the most predictable treatment option. Decision-making can be challenging and this paper aims to aid this process by discussing the assessment of prognosis, factors that need to be considered in decision-making and treatment options available. A flow chart to summarise this process is presented.

Factors affecting decision making at reassessment of periodontitis. Part 3: interpretation of clinical findings - local factors.

This paper is the third in a four-part series outlining treatment planning at periodontal reassessment. The first article focused on the information that should be gathered at the reassessment appointment. The second article discussed systemic factors that can relate to residual periodontal probing depths. This article outlines local factors that need to be assessed when faced with residual periodontal probing depths. Treatment can involve a range of non-surgical and surgical approaches. A variety of general, practical and local site factors can affect the choice of one option over another in choosing the most predictable treatment option.

Factors affecting decision making at reassessment of periodontitis. Part 2: interpretation of clinical findings - systemic factors.

This paper is the second in a four-part series outlining treatment planning at periodontal reassessment. The first article focussed on the information that should be gathered at the reassessment appointment. Treatment can involve a range of non-surgical and surgical approaches. A variety of general, practical and local site factors can affect the choice of one option over another in choosing the most predictable treatment option. Residual periodontal probing depths can be associated with both systemic and local factors. This article (part 2) outlines systemic factors that need to be assessed when faced with residual periodontal probing depths.

Factors affecting decision making at reassessment of periodontitis. Part 1: history and examination at reassessment.

Periodontal therapy aims to arrest the disease while maintaining function and aesthetics. Reassessment allows an opportunity to assess the periodontal status and need for further treatment. This is distinct from initial assessment in that the patient's response to initial therapy will be apparent and many treatment options other than non-surgical therapy require consideration. This series of papers outlines the processes to undergo at periodontal reassessment in order to assess viable treatment options and decide on a plan. This first article focuses on the information that should be gathered at the reassessment appointment in order to allow a full view of a case to aid decision-making. Subsequent papers in this series discuss the systemic and local factors that can account for residual probing depths, assessment of prognosis and treatment planning. Reassessment should be undertaken in a detailed manner to establish the reasons for any residual periodontal probing depths which will lead to the appropriate treatment option.

Position matching between the visual fields in strabismus.

The misalignment of visual input in strabismus disrupts positional judgments. We measured positional accuracy in the extrafoveal visual field (1°-7° eccentricity) of a large group of strabismic subjects and a normal control group to identify positional distortions associated with the direction of strabismus. Subjects performed a free localization task in which targets were matched in opposite hemifields whilst fixating on a central cross. The constant horizontal error of each response was taken as a measure of accuracy, in addition to radial and angular error. In monocular conditions, all stimuli were viewed by one eye; thus, the error reflected spatial bias. In dichoptic conditions, the targets were seen by separate eyes; thus, the error reflected the perceived stimulus shift produced by ocular misalignment in addition to spatial bias. In both viewing conditions, both groups showed reliable over- and underestimations of visual field position, here termed a compression of response coordinates. The normal group showed compression in the left periphery, regardless of eye of stimulation. The strabismic group showed a visual field-specific compression that was clearly associated with direction of strabismus. The variation in perceived shift of strabismic subjects was largely accounted for by the biases present in monocular viewing, suggesting that binocular correspondence was uniform in the tested region. The asymmetric strabismic compression could not be reproduced in normal subjects through prism viewing, and its presence across viewing conditions suggests a hemifield-specific change in spatial coding induced by long-standing ocular misalignment.

Has the quality of reporting in periodontology changed in 14 years? A systematic review.

BACKGROUND: Quality of reporting randomized controlled trials (RCTs) in periodontology has been poor. Consolidated Standards of Reporting Trials guidelines and an extension for non-pharmacologic trials (CONSORT-NPE), were introduced to aid in improving this. AIMS: The aim of this study was to assess the quality of reporting in periodontology, changes over the last 14 years, and adherence to CONSORT-NPE. METHODS: Randomized controlled trials in humans, published in three periodontal journals, from 2013 to 2015 were included. Search was conducted through Medline, Embase and hand searching. RESULTS: One hundred and seventy-three full-text articles included. Two reviewers screened for reporting quality (κ = 0.69, 95% CI 0.60-0.76). 84% of studies (n = 145) described randomization methods, 74% (n = 128) highlighted examiner blinding and 87% (n = 151) accounted for patients at study conclusion. Patient and caregiver blinding was addressed in 50% (n = 70) and 50% (n = 27) of studies respectively. 64% (n = 110) described adequate allocation concealment. Compared with Montenegro et al. (2002, Journal of Dental Research, 81, 866), improvements seen in describing randomization (2002, 16.5%; 2016, 84%), allocation concealment (2002, 6.5%; 2016, 64%), caregiver masking (2002, 17%; 2016, 50%). CONSORT-NPE; 62% (n = 107) had detailed explanations of all treatments, 88% (n = 152) lacked protocols for adherence of caregivers' to an intervention. Only 17% (n = 29) described caregivers' expertise and case volume. CONCLUSIONS: Substantial improvements have occurred. Attention is required for statistical analysis of patient losses and masking. CONSORT-NPE aspects were poorly reported.

A Tubular Aortopulmonary Window: An Embryological Curiosity.

We describe, in this report, an unusually shaped aortopulmonary communication observed in a six-month-old infant who presented with an associated ventricular septal defect. The defect was tubular, measuring 7 mm in length, and located intrapericardially between the proximal ascending aorta and the pulmonary trunk. It was well defined by transthoracic echocardiogram and was suitable for surgical ligation. We share our dilemma in naming this defect appropriately. We base our explanation on our understanding of normal development of the intrapericardial arterial trunks. There is initially an extensive aortopulmonary foramen. This is closed by apposition of a protrusion from the dorsal wall of the aortic sac, the aortopulmonary septum, with the distal margins of the outflow cushions. The spiral nature of formation of the aortopulmonary septum provides an understanding of the configuration of our tubular aortopulmonary window.

An update on crown lengthening. Part 1: Gingival tissue excess.

This is the first article in a two-part series which aims to provide an overview of the different techniques used to increase clinical crown height. In the first paper, the focus will be on the management of patients who present with gingival tissue excess. The different aetiologies are discussed and illustrated with clinical cases, following which a range of procedures that may be employed in the management of these patients are presented. With an increasingly ageing population, more patients are taking regular medications prescribed from their general medical practitioner, and so having a working knowledge of the specific drugs that may cause gingival enlargement is essential. Clinical Relevance: When patients with gingival tissue excess present in primary or secondary care, a clinician must have a good knowledge of the possible causes of the condition, as well as an idea of how the patient may be managed.