4,033 research outputs found

    Lacrimal Gland Involvement in Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome

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    PURPOSE: To describe the involvement of the lacrimal gland (LG) in blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). DESIGN: Observational, cross-sectional study. PARTICIPANTS: Twenty-one patients with BPES (10 female, 11 male) aged on average 15 years (range, 2-39 years), from 3 Brazilian medical centers and 1 Portuguese medical center. METHODS: Patients had their ocular surface evaluated with slit-lamp biomicroscopy, and tear production quantified with the Schirmer test I. The LG volumes were measured on computed tomography (CT) scans in the BPES sample and in a group of age-matched subjects imaged for nonorbital diseases. Sixteen patients were screened for mutations in the FOXL2 gene. MAIN OUTCOME MEASURES: Lacrimal meniscus height, Schirmer test I, presence of superficial punctate keratopathy (SPK), LG volume, and molecular analysis of the FOXL2 gene. RESULTS: Absence of LG was detected bilaterally in 9 patients (42.8%) and unilaterally in 2 patients (9.5%). When considering only patients with measurable LG, the median volume was 0.22 cm3 in the right eye (range, 0.06-0.36 cm3) and 0.24 cm3 in the left eye (range, 0.08-0.34 cm3). These values were significantly lower than those for the age-matched controls (median = 0.54 right eye and 0.53 left eye; P < 0.05). There was a significant association between deficiency of tear production and LG volume reduction and agenesis. Molecular analysis of the FOXL2 gene revealed the presence of 8 distinct mutations, 4 of them novel ones. A significant reduction of LG size or agenesis was associated with mutations affecting protein size (due to underlying changes in the stop codon location) or the DNA-binding forkhead domain (Fisher exact test, P = 0.021). In 3 probands, the underlying genetic defect was not found. CONCLUSIONS: This is the first study reporting LG volumes in BPES, describing a significant number of patients with LG agenesis. The association between alacrima and BPES is not incidental, and a thorough evaluation of tear production is recommended especially if ptosis surgery is planned.info:eu-repo/semantics/acceptedVersio

    Predicting Volleyball Serve-Reception

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    Serve and serve-reception performance have predicted success in volleyball. Given the impact of serve-reception on the game, we aimed at understanding what it is in the serve and receiver’s actions that determines the selection of the type of pass used in serve-reception and its efficacy. Four high-level players received jump-float serves from four servers in two reception zones – zone 1 and 5. The ball and the receiver’s head were tracked with two video cameras, allowing 3D world-coordinates reconstruction. Logistic-regression models were used to predict the type of pass used (overhand or underhand) and serve-reception efficacy (error, out, or effective) from variables related with the serve kinematics and related with the receiver’s on-court positioning and movement. Receivers’ initial position was different when in zone 1 and 5. This influenced the serve-related variables as well as the type of pass used. Strong predictors of using an underhand rather than overhand pass were higher ball contact of the server, reception in zone 1, receiver’s initial position more to the back of the court and backward receiver movement. Receiver’s larger longitudinal displacements and an initial position more to the back of the court had a strong relationship with the decreasing of the serve-reception efficacy. Receivers’ positioning and movement were the factors with the largest impact on the type of pass used and the efficacy of the reception. Reception zone affected the variance in the ball’s kinematics (with the exception of the ball’s lateral displacement), as well as in the receivers’ positioning (distances from the net and from the target). Also the reception zone was associated with the type of pass used by the receiver but not with reception efficacy. Given volleyball’s rotation rule, the receiver needs to master receiving in the different reception zones; he/she needs to adapt to the diverse constraints of each zone to maintain performance efficacy. Thus, being able to flexibly vary positioning and passing, given local (zone) constraints, can yield an advantage in high-level volleyball serve-reception. Further research needs to consider other serve modes (e.g., power-jump serve) and a full-court context of performance to support the present study’s findings

    Double excitation transitions in Mn2+ -doped alkali halides

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    4 págs.; 4 figs.It is shown in this work that the room-temperature excitation spectra of as-grown crystals of LiF, NaF, NaCl, KCl, and KBr doped with Mn2+ reveal the existence of double excitation peaks. These peaks are related to the formation of precipitated phases containing Mn2+ in the alkali halide lattice. In the case of LiF:Mn2+ the position of the [A14(G), E4(G)] and T14(G) peaks suggests an anomalously small Mn2+- F- distance for the precipitated phase. © 1983 The American Physical Society.Financial support by the Comision Asesora para la Investigacion Cientifica y Tecnica, is gratefully acknowledged.Peer Reviewe
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