Sequential MRI of growing scoliotic spines reveals individual level deformities that are clinically masked by the cobb angle

INTRODUCTION. Clinically, the Cobb angle method measures the overall scoliotic curve in the coronal plane but does not measure individual vertebra and disc wedging. The contributions of the vertebrae and discs in the growing scoliotic spine were measured to investigate coronal plane deformity progression with growth. METHODS. A 0.49mm isotropic 3D MRI technique was developed to investigate the level-by-level changes that occur in the growing spine of a group of Adolescent Idiopathic Scoliosis (AIS) patients, who received two to four sequential scans (spaced 3-12 months apart). The coronal plane wedge angles of each vertebra and disc in the major curve were measured to capture any changes that occurred during their adolescent growth phase. RESULTS. Seventeen patients had at least two scans. Mean patient age was 12.9 years (SD 1.5 years). Sixteen were classified as right-sided major thoracic Lenke Type 1 (one left sided). Mean standing Cobb angle at initial presentation was 31° (SD 12°). Six received two scans, nine three scans and two four scans, with 65% showing a Cobb angle progression of 5° or more between scans. Overall, there was no clear pattern of deformity progression of individual vertebrae and discs, nor between patients who progressed and those who didn’t. There were measurable changes in the wedging of the vertebrae and discs in all patients. In sequential scans, change in direction of wedging was also seen. In several patients there was reverse wedging in the discs that counteracted increased wedging of the vertebrae such that no change in overall Cobb angle was seen. CONCLUSION. Sequential MRI data showed complex patterns of deformity progression. Changes to the wedging of individual vertebrae and discs may occur in patients who have no increase in Cobb angle measure; the Cobb method alone may be insufficient to capture the complex mechanisms of deformity progression.

Three-dimensional corner reflector of arbitrary apex angle

A method of analysing a 3-dimensional corner reflector antenna of arbitrary apex angle is given. Expressions have been obtained for the far field of the 3-dimensional corner reflector fed by a dipole. The radiation resistance and the directive gain of the antenna have been calculated. The method described is applicable even when the feed dipole is arbitrarily oriented. It is found that the radiation along a prescribed direction can be circularly polarised (right or left) by suitably orienting the feed dipole.

Three-dimensional corner reflector of arbitrary apex angle

A method of analysing a 3-dimensional corner reflector antenna of arbitrary apex angle is given. Expressions have been obtained for the far field of the 3-dimensional corner reflector fed by a dipole. The radiation resistance and the directive gain of the antenna have been calculated. The method described is applicable even when the feed dipole is arbitrarily oriented. It is found that the radiation along a prescribed direction can be circularly polarised (right or left) by suitably orienting the feed dipole.

Evanescent-wave coupled right angled buried waveguide: Applications in carbon nanotube mode-locking

We present an evanescent-field device based on a right-angled waveguide. This consists of orthogonal waveguides, with their points of intersection lying along an angled facet of the chip. Light guided along one waveguide is incident at the angled dielectric-air facet at an angle exceeding the critical angle, so that the totally internally reflected light is coupled into the second waveguide. By depositing a nanotube film on the angled surface, the chip is then used to mode-lock an Erbium doped fiber ring laser with a repetition rate of 26 MHz, and pulse duration of 800 fs. © 2013 AIP Publishing LLC.

Corneal biomechanical properties in primary open angle glaucoma and normal tension glaucoma

PURPOSE: To determine and compare the corneal biomechanical properties between eyes with primary open angle glaucoma (POAG) and eyes with normal tension glaucoma (NTG). PATIENTS AND METHODS: Prospective cross-sectional study. Consecutive eligible POAG and NTG patients attending the Glaucoma Clinic had assessment of their corneal biomechanical properties-corneal hysteresis (CH) and corneal resistance factor (CRF)-using the Ocular Response Analyzer by an observer masked to the diagnosis. Exclusion criteria included previous intraocular surgery, corneal pathology, inflammatory connective tissue disease, and refraction of 5-dimensional or over. If both eyes were eligible, then the right eye was used for analysis. The main outcome measures were corneal hysteresis and CRF measurements. Data analysis was performed using the t test and general linear model. RESULTS: Eighty-one patients (80 whites) were analyzed. Forty had NTG, whereas 41 had POAG. Thirty-five were females. There was a statistically significant difference in mean CH (NTG 9.6±1.3 mm Hg; POAG 9.0±1.4 mm Hg; P=0.01), but not in mean CRF (NTG 9.9±1.4; POAG 10.8±1.7; P=0.06). The highest recorded Goldmann applanation intraocular pressure (IOP) was statistically significantly associated with lower CH (P=0.01) and higher CRF (P=0.02). CONCLUSIONS: There was a small but statistically significant difference in the mean CH between POAG and NTG (CH was higher in NTG). The highest recorded Goldmann applanation IOP was also statistically significantly correlated with lower CH and higher CRF, suggesting that alterations to the corneal biomechanical properties may occur as a result of chronic raised IOP in POAG. © 2008 by Lippincott Williams & Wilkins.

Determinants and two-year change in anterior chamber angle width in a Chinese population

Objective: To study the population distribution and longitudinal changes in anterior chamber angle width and its determinants among Chinese adults. Design: Prospective cohort, population-based study. Participants: Persons aged 35 years or more residing in Guangzhou, China, who had not previously undergone incisional or laser eye surgery. Methods: In December 2008 and December 2010, all subjects underwent automated keratometry, and a random 50% sample had anterior segment optical coherence tomography with measurement of angle-opening distance at 500 μm (AOD500), angle recess area (ARA), iris thickness at 750 μm (IT750), iris curvature, pupil diameter, corneal thickness, anterior chamber width (ACW), lens vault (LV), and lens thickness (LT) and measurement of axial length (AL) and anterior chamber depth (ACD) by partial coherence laser interferometry. Main Outcome Measures: Baseline and 2-year change in AOD500 and ARA in the right eye. Results: A total of 745 subjects were present for full biometric testing in both 2008 and 2010 (mean age at baseline, 52.2 years; standard deviation [SD], 11.5 years; 53.7% were female). Test completion rates in 2010 varied from 77.3% (AOD500: 576/745) to 100% (AL). Mean AOD500 decreased from 0.25 mm (SD, 0.13 mm) in 2008 to 0.21 mm (SD, 13 mm) in 2010 (difference, -0.04; 95% confidence interval [CI], -0.05 to -0.03). The ARA decreased from 21.5±3.73 10^-2 mm² to 21.0±3.64 10 ^-2 mm² (difference, -0.46; 95% CI, -0.52 to -0.41). The decrease in both was most pronounced among younger subjects and those with baseline AOD500 in the widest quartile at baseline. The following baseline variables were significantly associated with a greater 2-year decrease in both AOD500 and ARA: deeper ACD, steeper iris curvature, smaller LV, greater ARA, and greater AOD500. By using simple regression models, we could explain 52% to 58% and 93% of variation in baseline AOD500 and ARA, respectively, but only 27% and 16% of variation in 2-year change in AOD500 and ARA, respectively. Conclusions: Younger persons and those with the least crowded anterior chambers at baseline have the largest 2-year decreases in AOD500 and ARA. The ability to predict change in angle width based on demographic and biometric factors is relatively poor, which may have implications for screening. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology.

Le devoir syndical de représentation sous l'angle de la Charte des droits et libertés de la personne: le cas des clauses" orphelin"

En raison des présentes transformations du marché du travail, le mouvement syndical est à la recherche d’un nouvel équilibre. Dans ce contexte plutôt changeant, réorganisations et flexibilité se négocient en échange d’une protection accrue pour ceux qui demeurent en emploi. Si d’une part, ceci mène à une prolifération de nouvelles formes d’emploi atypiques et de disparités de traitement, d’autre part la constitutionnalisation du droit du travail change le rapport quant à l’universalisme syndical. Nous nous sommes alors interrogée sur les impacts que cela peut avoir sur le devoir syndical de représentation. Prenant cela en considération, nous avons voulu au cours de notre recherche faire la lumière tant sur certains impacts de la négociation de clauses de disparité de traitement dans les milieux de travail syndiqués que sur les défis contemporains du droit du travail et de l’emploi. Cette thèse propre au champ d’études que sont les relations industrielles se distingue des autres recherches dans le même domaine en se concentrant sur l’effet empirique de la mise en œuvre d’une norme, par l’étude de deux cas suggestifs. Plus précisément, notre thèse avait comme principal objectif de répondre à la question suivante : Quels sont les effets sur l’acteur (action) syndical du recours à la norme d’égalité, à la suite la négociation de clauses « orphelin »? Pour y parvenir, nous avons dû reconstituer comment les acteurs syndicaux s’étaient approprié l’espace ouvert par la constitutionnalisation du droit du travail. Nous avons utilisé une méthode qualitative, impliquant une revue de la littérature sociohistorique, théorique et juridique, une analyse de la jurisprudence existant à ce sujet et l’étude de deux cas portant sur la négociation d’une clause « orphelin » le tout représentant soixante entrevues semi-dirigées dans plusieurs casernes et palais de justice. Les connaissances acquises permettent au plan empirique une meilleure compréhension des interactions possibles entre acteurs, institutions et stratégies lors de la mise en œuvre de la norme d’égalité ainsi que des déterminants de l’action (ou de l’inaction) syndicale. Sur le plan pratique, nous espérons que notre thèse puisse guider toute personne ou tout groupe de personnes désirant mettre en œuvre des mesures égalitaires, tant pour éviter certains écueils reliés à ces actions ou réactions suscitées par la mise en œuvre du droit à l’égalité, que pour mesurer l’efficacité des actions entreprises. De surcroît, sur le plan théorique, nous croyons que de mettre à l’épreuve un modèle théorique recoupant stratégies et institutions permettra d’aborder les problèmes à la fois au niveau de l’acteur et au niveau structurel. Les résultats obtenus aident à comprendre en quoi et comment peut se construire l’action syndicale dans certains (2) cas de mise en œuvre de la norme d’égalité. Le choix de différentes stratégies ne peut pas être dissocié des différents contextes économiques, sociaux et juridiques, ni des capacités stratégiques des différents acteurs en cause. Les principales contraintes identifiées ont pu être imputées tant aux structures de l’association syndicale qu’aux différents univers normatifs mobilisés. Les sources de tensions vécues dans les milieux à l’étude ont été rattachées notamment aux perceptions d’injustice et à la méconnaissance des différentes normes juridiques. En conséquence, il faut conclure que pour les associations syndicales (sans se restreindre à celles à l’étude), la question d’iniquité pourrait avoir de graves conséquences et non seulement sur le devoir de représentation. Nous avons spécialement souligné la fragilisation de leurs assises, dans leurs deux pôles d’actions : d’acteur économique (faille dans la capacité d’action traditionnelle) et d’acteur politique (climat hostile au syndicalisme). Nous souhaitons que l’acteur syndical puisse mobiliser, à la lumière des résultats de notre recherche, des arguments concourant à repenser l’action syndicale, que nous croyons être plus pertinente que jamais. Nous croyons également que les différents acteurs du monde du travail pourraient s’approprier certaines de nos recommandations afin de favoriser une citoyenneté au travail plus inclusive.

Hemodynamic evaluation of the right portal vein in healthy dogs of different body weights

Background: Doppler ultrasonography is an important tool for evaluating hepatic portal hemodynamics. However, no study in dogs of different body weights, in the range encountered in routine clinical veterinary practice, has been reported. It can be difficult to obtain an ideal insonation angle when evaluating the main portal vein, so evaluation of the right portal vein branch has been described in humans as an alternative. The aim of this study was to analyze, through Doppler ultrasonography, the hemodynamics in the right portal vein branch in dogs of different body weights.Methods: Thirty normal dogs were divided in three groups by weight, in order to establish normal values for mean velocity, flow volume and portal congestion index of the right portal vein branch by means of Doppler ultrasonography.Results: In all dogs ideal insonation angles were obtained for the right portal vein branch. The average velocity was similar in the three groups, but the portal congestion index and the flow volume differed, showing that the weight of the dog can influence these values.Conclusion: Doppler ultrasonography for the evaluation of flow in the right branch of the portal vein could be a viable alternative, or complement, to examining the main vessel segment. This is especially so in those animals in which an ideal insonation angle for examination of the main portal vein is hard to obtain. In addition, the weight of the dog must be considered for the correct evaluation of the portal system hemodynamics, particularly for portal blood flow and the congestion index.

Search for right-handed W bosons in top quark decay

We present a measurement of the fraction f(+) of right-handed W bosons produced in top quark decays, based on a candidate sample of t (t) over bar events in the lepton+jets decay mode. These data correspond to an integrated luminosity of 230 pb(-1), collected by the D0 detector at the Fermilab Tevatron p (p) over bar Collider at root s=1.96 TeV. We use a constrained fit to reconstruct the kinematics of the t (t) over bar and decay products, which allows for the measurement of the leptonic decay angle theta(*) for each event. By comparing the cos theta(*) distribution from the data with those for the expected background and signal for various values of f(+), we find f(+)=0.00 +/- 0.13(stat)+/- 0.07(syst). This measurement is consistent with the standard model prediction of f(+)=3.6 x 10(-4).

Avaliação das dimensões e relacionamentos dos arcos dentários no tratamento da má-oclusão classe II, divisão 1 de Angle com aparelho bionator de Balters

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da movimentação dentária fisiológica durante o tratamento da Classe I de Angle após a extração de pré-molares

Pós-graduação em Odontologia - FOA

Left-right asymmetries in polarized e-mu scattering

We consider, in the electroweak standard model context, several left-right asymmetries in μe elastic scattering at fixed target and collider experiments. For the former case, we show that the muon mass effects are important in a wide energy range. We also show that these asymmetries are sensitive to the electroweak mixing angle θW. The effect of an extra Z' neutral vector boson appearing in a 3-3-1 model is also considered. The capabilities of these asymmetries in the search of this extra Z' are addressed.

Combined pre- and subtemporal transtentorial approach for epidermoid cysts of the cerebellopontine angle

Objective Epidermoid cysts of the cerebellopontine angle (CPA) can be a surgical challenge for the pediatric neurosurgeon. Ideally, total removal must be achieved; however, occasional adhesions of these tumors to vital neurovascular structures and extension far beyond the midline may preclude their total removal. The aims of this article are to present an alternative surgical approach to these lesions and to provide the rationale for this technique. Material and methods A 16-year-old boy was admitted to our pediatric neurosurgery department with a 1-year history of nonspecific headaches. His neurological examination showed right-sided dysmetria and gait ataxia. Magnetic resonance scans showed a space-occupying lesion on the right CPA with low intensity on T-1-weighted images and high intensity on T-2-weighted images. Results Craniotomy for tumor excision via pre- and subtemporal transtentorial approach was performed disclosing a 3.5 x 3 x 2.8-cm(3) well-encapsulated tumor, which was confirmed to be an epidermoid cyst. The postoperative course was uneventful. Conclusions A combined pre- and subtemporal approach utilizes a wide opening of the tentorium and the option of supratentorial retraction of the cerebellum to provide an excellent angle of approach to CPA lesions involving the anterolateral aspect of the brain stem in children.

AVALIAÇÃO DA PROPORÇÃO DENTAL DE BOLTON EM INDIVÍDUOS COM OCLUSÃO NORMAL NATURAL E MALOCLUSÕES DE CLASSE I E CLASSE II DIVISÃO 1 DE ANGLE.

Introdução: A análise de Bolton, análise que quantifica o tamanho dentário, é uma referência importante para profissionais que buscam finalizações ortodônticas adequadas. Objetivo: O objetivo deste trabalho é verificar se há discrepância entre os indivíduos com oclusão normal natural e maloclusões de Classe I e de Classe II divisão 1 de Angle pertencentes a amostra selecionada, em relação aos valores encontrados por Bolton, bem como verificar também se há dimorfismo sexual. Metodologia: 3 grupos contendo 35 pares e modelos em gesso cada, separados pelo tipo de oclusão, pertencentes ao acervo do programa de pós-graduação em Ortodontia da Universidade Metodista de São Paulo foram medidos com paquímetro digital em sua maior distância mésiodistal desde 1º molar direito a 1º molar esquerdo, dos arcos superiores e inferiores, com dentição permanente. Os valores foram tabulados e a proporção de Bolton foi aplicada. Resultados: Respectivamente para os grupos 1, 2 e 3, a proporção total encontrada foi de 90,36 (DP±1,70), 91,17 (DP±2,58) e 90,76 (DP±2,45), e a proporção anterior foi de 77,73 (DP±2,39), 78,01 (DP±2,66) e 77,30 (DP±2,65). Conclusão: não houve dimorfismo sexual nem diferença estatisticamente significante comparando os valores aos sugeridos por Bolton.

Abnormal systemic and ocular vascular response to temperature provocation in primary open-angle glaucoma patients:a case for autonomic failure?

PURPOSE. To assess systemic and ocular vascular reactivity in response to warm and cold provocation in untreated patients with primary open-angle glaucoma and normal control subjects. METHODS. Twenty-four patients with primary open-angle glaucoma and 22 normal control subjects were subjected to a modified cold pressor test involving immersion of the right hand in 40°C warm water followed by 4°C cold water exposure, and finger and ocular blood flow were assessed by means of peripheral laser Doppler flowmetry and retinal flowmetry, respectively. Finger and body temperature as well as intraocular pressure, systemic blood pressure, systemic pulse pressure, heart rate, and ocular perfusion pressure were also monitored. RESULTS. The patients with glaucoma demonstrated an increase in diastolic blood pressure (P = 0.023), heart rate (P = 0.010), and mean ocular perfusion pressure (P = 0.039) during immersion of the tested hand in 40°C water. During cold provocation, the patients demonstrated a significant decrease in finger (P = 0.0003) and ocular blood flow (the parameter velocity measured at the temporal neuroretinal rim area; P = 0.021). Normal subjects did not demonstrate any blood flow or finger temperature changes during immersion of the tested hand in 40°C water (P > 0.05); however, they exhibited increases in systolic blood pressure (P = 0.034) and pulse pressure (P = 0.0009) and a decrease in finger blood flow (P = 0.0001) during cold provocation. In normal subjects, the ocular blood flow was unchanged during high- and low-temperature challenge. CONCLUSIONS. Cold provocation elicits a different blood pressure, and ocular blood flow response in patients with primary open-angle glaucoma compared with control subjects. These findings suggest a systemic autonomic failure and ocular vascular dysregulation in POAG patients.