2D-3D registration of CT vertebra volume to fluoroscopy projection: A calibration model assessment (doi:10.1155/2010/806094)

This study extends a previous research concerning intervertebral motion registration by means of 2D dynamic fluoroscopy to obtain a more comprehensive 3D description of vertebral kinematics. The problem of estimating the 3D rigid pose of a CT volume of a vertebra from its 2D X-ray fluoroscopy projection is addressed. 2D-3D registration is obtained maximising a measure of similarity between Digitally Reconstructed Radiographs (obtained from the CT volume) and real fluoroscopic projection. X-ray energy correction was performed. To assess the method a calibration model was realised a sheep dry vertebra was rigidly fixed to a frame of reference including metallic markers. Accurate measurement of 3D orientation was obtained via single-camera calibration of the markers and held as true 3D vertebra position; then, vertebra 3D pose was estimated and results compared. Error analysis revealed accuracy of the order of 0.1 degree for the rotation angles of about 1?mm for displacements parallel to the fluoroscopic plane, and of order of 10?mm for the orthogonal displacement.<br/

Nasal pathologies in patients with obstructive sleep apnoea

Nasal obstruction is a frequent condition in patients with obstructive sleep apnoea (OSA). Nasal obstruction leads to mouth breathing, which is thought to destabilise the upper airway to aggravate the condition. Three conditions could be considered as the cause of the nasal breathing obstruction: anatomical conditions of the nose (septum deviation, hypertrophy of the inferior turbinates), chronic rhinosinusitis (CRS) and chronic nasal inflammation caused by allergic rhinitis or non-allergic cellular rhinitis. In this prospective study, we present an evaluation of all these possible rhino-sinusal aspects in OSA patients to correlate different nasal pathologies with nasal obstruction. Fifty patients with a diagnosis of OSA were enrolled in the study. In 70% of OSA patients, nasal obstruction was confirmed by clinical evaluation and rhinomanometry testing. Normal rhino-sinus aspects were present in only 20% of OSAS patients, whereas one or more pathological rhino-sinus conditions were present in the remaining 80%. The percentage of OSA patients with a diagnosis of allergic rhinitis and non-allergic rhinitis was 18% and 26% respectively. Non-allergic rhinitis with neutrophils (NARNE) was the most frequent type of cellular rhinitis diagnosed in OSA patients (20% of cases). The results of the present study support and extend the observation that rhinitis is present in OSA patients. Mucosal inflammation caused by these conditions could be the cause of upper airway patency impairment inducing nasal mucosa swellin

Real-time price discovery in stock, bond and foreign exchange markets

We characterize the response of U.S., German and British stock, bond and foreign exchange markets to real-time U.S. macroeconomic news. Our analysis is based on a unique data set of high-frequency futures returns for each of the markets. We find that news surprises produce conditional mean jumps; hence high-frequency stock, bond and exchange rate dynamics are linked to fundamentals. The details of the linkages are particularly intriguing as regards equity markets. We show that equity markets react differently to the same news depending on the state of the economy, with bad news having a positive impact during expansions and the traditionally-expected negative impact during recessions. We rationalize this by temporal variation in the competing "cash flow" and "discount rate" effects for equity valuation. This finding helps explain the time-varying correlation between stock and bond returns, and the relatively small equity market news effect when averaged across expansions and recessions. Lastly, relying on the pronounced heteroskedasticity in the high-frequency data, we document important contemporaneous linkages across all markets and countries over-and-above the direct news announcement effects. JEL Klassifikation: F3, F4, G1, C

Eustachian tube dysfunction in children with adenoid hypertrophy: the role of adenoidectomy for improving ear ventilation

Introduction: To our knowledge, few papers have addressed preoperative evaluation of the impact of adenoid hypertrophy (AH) on the pathogenesis of eustachian tube dysfunction (ETD) in children with otitis media with effusion (OME). Aim: The aim of this study was 2-fold: first, to evaluate ETD using tubomanometry and Eustachian Tube Score 7 (ETS-7), in a group of children having AH; second, to assess the clinical impact of adenoidectomy on the ETD of these patients. Methods: Fifty patients, aged 4 to 15 years, underwent adenoidectomy based on various parameters: size of the adenoids causing canal obstruction (grades 1-4), the presence of OME, and recurrent episodes of rhinosinusitis. The function of the eustachian tube was evaluated using ETS-7 before and after surgical treatment. The patients were followed up for 6 months. Results: Forty children presented ETD. Of these, 36 had a grade 4 AH. The preoperative mean value for ETS-7 was 6.62. The mean postoperative ETS-7 score showed a value of 9.60 with a statistical difference compared to the preoperative value (P =.0015). Conclusions: Adenoid hypertrophy has a high impact on the frequency of ETD. In the patients observed in the present study, the ETS-7 score appeared to be a valid tool for assessing ETD both preoperatively and postoperatively. Adenoidectomy seemed to be effective in improving ETD as well as middle ear ventilation

Global approaches and local strategies for phase unwrapping

Phase unwrapping, i.e. the retrieval of absolute phases from wrapped, noisy measures, is a tough problem because of the presence of rotational inconsistencies (residues), randomly generated by noise and undersampling on the principal phase gradient field. These inconsistencies prevent the recovery of the absolute phase field by direct integration of the wrapped gradients. In this paper we examine the relative merit of known global approaches and then we present evidence that our approach based on “stochastic annealing” can recover the true phase field also in noisy areas with severe undersampling, where other methods fail. Then, some experiments with local approaches are presented. A fast neural filter has been trained to eliminate close residue couples by joining them in a way which takes into account the local phase information. Performances are about 60–70% of the residues. Finally, other experiments have been aimed at designing an automated method for the determination of weight matrices to use in conjunction with local phase unwrapping algorithms. The method, tested with the minimum cost flow algorithm, gives good performances over both simulated and real data

The IASI Water Deficit Index to Monitor Vegetation Stress and Early Drying in Summer Heatwaves: An Application to Southern Italy

The boreal hemisphere has been experiencing increasing extreme hot and dry conditions over the past few decades, consistent with anthropogenic climate change. The continental extension of this phenomenon calls for tools and techniques capable of monitoring the global to regional scales. In this context, satellite data can satisfy the need for global coverage. The main objective we have addressed in the present paper is the capability of infrared satellite observations to monitor the vegetation stress due to increasing drought and heatwaves in summer. We have designed and implemented a new water deficit index (wdi) that exploits satellite observations in the infrared to retrieve humidity, air temperature, and surface temperature simultaneously. These three parameters are combined to provide the water deficit index. The index has been developed based on the Infrared Atmospheric Sounder Interferometer or IASI, which covers the infrared spectral range 645 to 2760 cm−1 with a sampling of 0.25 cm−1. The index has been used to study the 2017 heatwave, which hit continental Europe from May to October. In particular, we have examined southern Italy, where Mediterranean forests suffer from climate change. We have computed the index’s time series and show that it can be used to indicate the atmospheric background conditions associated with meteorological drought. We have also found a good agreement with soil moisture, which suggests that the persistence of an anomalously high water deficit index was an essential driver of the rapid development and evolution of the exceptionally severe 2017 droughts

Proteinuria in focal segmental glomerulosclerosis: role of circulating factors and therapeutic approach.

The clinical course of primary Focal Segmental Glomerulosclerosis (FSGS) is frequently complicated by nephrotic range proteinuria and progression to renal failure. The high recurrence rate of the disease in transplanted kidney suggests the hypothesis that such patients have a circulating factor that alters glomerular capillary permeability. In recent years some authors found that serum from patients with FSGS increases glomerular permeability to albumin and partially identified the permeability factor (PF) as a protein of 30-50 Kd m.w. The removal of this protein by means of Plasma Exchange (PE) or plasma Immunoadsorption by Protein A (IA) decreased proteinuria. In this report we provide preliminary data about the prevalence of PF and the therapeutic effect of its removal by IA, in 3 pts with recurrence in the transplanted kidney, and 4 with FSGS of the native kidneys. They were resistant to corticosteroids (CS) and immunosuppressive (IS) therapy. 10 IA sessions were performed in 4 weeks: if a remission was achieved IA was gradually tapered. The level of PF in the serum was measured by an in vitro assay to determine the glomerular permeability to albumin. The FSGS was histologically proven in all cases and the degree of evolution was evaluated. PF levels, serum creatinine, daily proteinuria and serum albumin were monitored. The 3 patients with recurrent FSGS had a normalization of the PF levels; 2 had a clinical remission. In FSGS of native kidneys PF was elevated in 3/4 cases; 1 had a clinical remission; 2 with extensive sclerohyalinosis and 1 without PF levels did not improve. Our results confirm that most patients with FSGS have high PF serum levels and suggest that its removal can be beneficial

High-frequency information content in end-user foreign exchange order flows

This article considers the impact of foreign exchange (FX) order flows on contemporaneous and future stock market returns using a new database of customer order flows in the euro-dollar exchange rate market as seen by a leading European bank. We do not find clear contemporaneous relationships between FX order flows and stock market changes at high frequencies, but FX flows do appear to have significant power to forecast stock index returns over 1–30 min horizons, after controlling for lagged exchange rate and stock market returns. The effects of order flows from financial customers on future stock market changes are negative, while the effects of corporate orders are positive. The latter results are consistent with the premise that corporate order flows contain dispersed, passively acquired information about fundamentals. Thus, purchases of the dollar by corporate customers represent good news about the state of the US economy. Importantly, though, there also appears to be extra information in corporate flows which is directly relevant to equity prices over and above the impact derived from stock prices reacting to (predicted) exchange rate changes. Our findings suggest that financial customer flows only affect stock prices through their impact on the value of the dollar