50 research outputs found

    A Lagrangian trajectory view on transport and mixing processes between the eye, eyewall, and environment using a high resolution simulation of Hurricane Bonnie (1998)

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    The transport and mixing characteristics of a large sample of air parcels within a mature and vertically sheared hurricane vortex is examined. Data from a high-resolution (2 km grid spacing) numerical simulation of "real-case" Hurricane Bonnie (1998) is used to calculate Lagrangian trajectories of air parcels in various subdomains of the hurricane (namely, the eye, eyewall, and near-environment) to study the degree of interaction (transport and mixing) between these subdomains. It is found that 1) there is transport and mixing from the low-level eye to the eyewall that carries high- Be air which can enhance the efficiency of the hurricane heat engine; 2) a portion of the low-level inflow of the hurricane bypasses the eyewall to enter the eye, that both replaces the mass of the low-level eye and lingers for a sufficient time (order 1 hour) to acquire enhanced entropy characteristics through interaction with the ocean beneath the eye; 3) air in the mid- to upper-level eye is exchanged with the eyewall such that more than half the air of the eye is exchanged in five hours in this case of a sheared hurricane; and 4) that one-fifth of the mass in the eyewall at a height of 5 km has an origin in the mid- to upper-level environment where thet(sub e) is much less than in the eyewall, which ventilates the ensemble average eyewall theta(sub e) by about 1 K. Implications of these findings to the problem of hurricane intensity forecasting are discussed

    Cerebral cortex maldevelopment in syndromic craniosynostosis

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    AIM: To assess the relationship of surface area of the cerebral cortex to intracranial volume (ICV) in syndromic craniosynostosis. METHOD: Records of 140 patients (64 males, 76 females; mean age 8y 6mo [SD 5y 6mo], range 1y 2mo–24y 2mo) with syndromic craniosynostosis were reviewed to include clinical and imaging data. Two hundred and three total magnetic resonance imaging (MRI) scans were evaluated in this study (148 patients with fibroblast growth factor receptor [FGFR], 19 patients with TWIST1, and 36 controls). MRIs were processed via FreeSurfer pipeline to determine total ICV and cortical surface area (CSA). Scaling coefficients were calculated from log‐transformed data via mixed regression to account for multiple measurements, sex, syndrome, and age. Educational outcomes were reported by syndrome. RESULTS: Mean ICV was greater in patients with FGFR (1519cm(3), SD 269cm(3), p=0.016) than in patients with TWIST1 (1304cm(3), SD 145cm(3)) or controls (1405cm(3), SD 158cm(3)). CSA was related to ICV by a scaling law with an exponent of 0.68 (95% confidence interval [CI] 0.61–0.76) in patients with FGFR compared to 0.81 (95% CI 0.50–1.12) in patients with TWIST1 and 0.77 (95% CI 0.61–0.93) in controls. Lobar analysis revealed reduced scaling in the parietal (0.50, 95% CI 0.42–0.59) and occipital (0.67, 95% CI 0.54–0.80) lobes of patients with FGFR compared with controls. Modified learning environments were needed more often in patients with FGFR. INTERPRETATION: Despite adequate ICV in FGFR‐mediated craniosynostosis, CSA development is reduced, indicating maldevelopment, particularly in parietal and occipital lobes. Modified education is also more common in patients with FGFR

    Intracranial hypertension and cortical thickness in syndromic craniosynostosis

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    Aim: To evaluate the impact of risk factors for intracranial hypertension (ICH) on cerebral cortex thickness in syndromic craniosynostosis. Method: ICH risk factors including papilloedema, hydrocephalus, obstructive sleep apnea (OSA), cerebellar tonsillar position, occipitofrontal circumference (OFC) curve deflection, age, and sex were collected from the records of patients with syndromic craniosynostosis (Apert, Crouzon, Pfeiffer, Muenke, Saethre-Chotzen syndromes) and imaging. Magnetic resonance images were analysed and exported for statistical analysis. A linear mixed model was developed to determine correlations with cerebral cortex thickness changes. Results: In total, 171 scans from 107 patients (83 males, 88 females, mean age 8y 10mo, range 1y 1mo–34y, SD 5y 9mo) were evaluated. Mean cortical thickness in this cohort was 2.78mm (SD 0.17). Previous findings of papilloedema (p=0.036) and of hydrocephalus (p=0.007) were independently associated with cortical thinning. Cortical thickness did not vary significantly by sex (p=0.534), syndrome (p=0.896), OSA (p=0.464), OFC (p=0.375), or tonsillar position (p=0.682). Interpretation: Detection of papilloedema or hydrocephalus in syndromic craniosynostosis is associated with significant changes in cortical thickness, supporting the need for preventative rather than reactive treatment strategies

    Transoral Submucosal Resection of the Inferior Turbinate A Novel Approach to Functional Rhinoplasty

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    Background: In the presence of turbinate dysfunction, an inferior turbinectomy for persistent hypertrophy of bone and/or mucosa may be performed. We sought to explore anatomic feasibility of a transoral turbinectomy. Methods: After transoral inferior turbinectomy in 12 cadavers, average distances from the external nasal valve to inferior turbinate and from pyriform aperture to inferior turbinate were compared. Average "area of access" was calculated. Preoperative and postoperative nasal length, tip projection, and alar-base width were also compared. Results: Average distance from external nasal valve to inferior turbinate was 32.4 mm. Average distance from aperture to inferior turbinate was 2.4 mm (P < 0.0001). Average "areas of access" to nasal vault through the external nasal valve and mouth were 183.9 mm(2) and 243.6 mm(2) (P = 0.07), respectively. Conclusions: The transoral approach provides a larger "area of access" to the turbinate, a statistically significant reduction of distance to target, no postoperative changes in nasal soft tissue, and easier instrumentation

    Malignant peripheral nerve sheath tumors. A clinicopathologic study of 28 cases.

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    BACKGROUND: In order to improve management, the files and tissue sections of 28 cases of malignant peripheral nerve sheath tumors (MPNST) diagnosed at the University of Virginia Health Sciences Center between 1960 and 1990 were reviewed. METHODS: Clinical data tabulated included age, sex, race, the presence or absence of von Recklinghausen neurofibromatosis type 1 (NF-1), tumor size, tumor location, type of treatment, and status of surgical margins. Pathologic study included assessment of mitotic rate, divergent differentiation, cellular atypia, necrosis, and vascular reaction. RESULTS: The median disease-free survival time was 11 months, and the median overall survival time was 44 months. Overall survival and disease-free survival were significantly influenced by patient age, tumor location, tumor size, extent of surgery, and quality of margins. Patients with a family history of neurofibromatosis also had better disease-free survival. None of the other clinical variables correlated with survival. CONCLUSIONS: The authors recommended that patients with NF-1 be followed closely for MPNST development. For most cases, treatment should include aggressive surgery with wide surgical margins combined with adjuvant radiation therapy. Chemotherapy may have a role for treatment failures

    Preferences of Transgender and Gender-Nonconforming Persons in Gender-Confirming Surgical Care

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    INTRODUCTION: Increased awareness for transgender and gender-nonconforming individuals may lead to increased demand for surgical interventions in gender-confirming care. However, limited literature exists regarding transgender and gender-nonconforming preferences and experiences with medical or surgical care. The authors aim to characterize the medical and surgical care sought by this population, as well as their surgical preferences, motivations, and barriers to care. METHODS: An online questionnaire about opinions and personal experiences with medical and surgical care during gender transition was publicized via regional online social networking forums in Connecticut and surrounding areas catering to transgender communities. RESULTS: Responses were received from 313 participants. Participants were 97% male gender at birth and 92% white with an average (SD) age of 51.6 (13.5) years. Fifty-nine percent identified as male-to-female transgender and 20% as gender nonconforming. Respondents were aware of their gender identity at a mean (SD) age of 9.6 (9.0) years, but did not begin transitioning until a mean (SD) age of 38.9 (20.8) years, with gender-nonconforming respondents choosing to transition at a significantly younger age as compared with transgender respondents (29.8 vs 41.4 years; P = 0.0061, unpaired t test). Only 42% of all respondents, with a significantly greater number of transgender as opposed to gender-nonconforming individuals, had previously met with a physician to discuss transitioning (49% vs 21%, P = 0.002, χ test). Eight percent of the study population had undergone gender confirmation surgery (GCS), 52% were interested in GCS, and 40% were not interested in GCS. Primary motivation for GCS included discomfort in one\u27s current body (28%), and barriers to GCS included cost (40%) and reactions of family (40%), partners (32%), and friends (25%). CONCLUSIONS: Transgender and gender-nonconforming individuals lack medical support for gender transition, with fewer than half of survey respondents reporting a prior meeting with a physician to discuss transitioning. The reported perspectives offer important insight into transgender preferences that should act as the basis of future efforts to improve the efficacy of gender-confirming care
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