An Adaptive Algorithm for Multipath Mitigation in GNSS Positioning with Android Smartphones

We present a solution for improving the robustness of GNSS positioning with Android devices. The proposed method combines an acquisition phase performed in a dedicated Android app (thus working on the edge) and a processing phase, based on a modified version of the open source library RTKLIB, performed on a dedicated server. The processing phase applies an improved version of the RTK library based on an adaptive algorithm for mitigating the multipath effect on satellite radio signals received by smartphone’s antennas. The algorithm is built on top of an extended version of the sigma-epsilon model in which weights associated to observables potentially affected by multipath errors are computed using logged data. In the paper, we will focus our attention on the architecture of the proposed solution and discuss preliminary experimental results obtained with the resulting system

Frontier in three-dimensional cave reconstruction—3D meshing versus textured rendering

Underground caves and their specific structures are important for geomorphological studies. This paper investigates the capabilities of a new modelling approach advanced for true-to-life three-dimensional (3D) reconstruction of cave with full resolution scan relative to 3D meshing. The cave was surveyed using terrestrial laser scanner (TLS) to acquire high resolution scans. The data was processed to generate a 3D-mesh model and textured 3D model using sub-sampled points and full resolution scan respectively. Based on both point and solid surface representation, comparative analysis of the strengths and weaknesses of the two approaches were examined in terms of data processing efficiency, visualization, interactivity and geomorphological feature representation and identification. The result shows that full scan point representation offers advantage for dynamic visualization over the decimated xyz point data because of high density of points and availability of other surface information like point normal, intensity and height which can be visualized in colour scale. For the reconstructed surface, mesh model is better with respect to interactivity and morphometric but 3D rendering shows superiority in visual reality and identification of micro detail of features with high precision. Complementary use of the two will provide better understanding of the cave, its development and processes

Induction chemotherapy followed by concurrent standard radiotherapy and daily low-dose cisplatin in locally advanced non-small-cell lung cancer

Both induction chemotherapy and concurrent low-dose cisplatin have been shown to improve results of thoracic irradiation in the treatment of locally advanced non-small-cell lung cancer (NSCLC). This phase II study was designed to investigate activity and feasibility of a novel chemoradiation regimen consisting of induction chemotherapy followed by standard radiotherapy and concurrent daily low-dose cisplatin. Previously untreated patients with histologically/cytologically proven unresectable stage IIIA/B NSCLC were eligible. Induction chemotherapy consisted of vinblastine 5 mg m−2 intravenously (i.v.) on days 1, 8, 15, 22 and 29, and cisplatin 100 mg m−2 i.v. on days 1 and 22 followed by continuous radiotherapy (60 Gy in 30 fractions) given concurrently with daily cisplatin at a dose of 5 mg m−2 i.v. Thirty-two patients were enrolled. Major toxicity during induction chemotherapy was haematological: grade III–IV leukopenia was observed in 31% and grade II anaemia in 16% of the patients. The most common severe toxicity during concurrent chemoradiation consisted of grade III leukopenia (21% of the patients); grade III oesophagitis occurred in only two patients and pulmonary toxicity in one patient who died of this complication. Eighteen of 32 patients (56%, 95% CI 38–73%) had a major response (11 partial response, seven complete response). With a median follow-up of 38.4 months, the median survival was 12.5 months and the actuarial survival rates at 1, 2 and 3 years were 52%, 26% and 19% respectively. The median event-free survival was 8.3 months with a probability of 40%, 23% and 20% at 1, 2 and 3 years respectively. Induction chemotherapy followed by concurrent daily low-dose cisplatin and thoracic irradiation, in patients with locally advanced NSCLC, is active and feasible with minimal non-haematological toxicity. Long-term survival results are promising and appear to be similar to those of more toxic chemoradiation regimens, warranting further testing of this novel chemoradiation strategy. © 1999 Cancer Research Campaig

High Differentiation among Eight Villages in a Secluded Area of Sardinia Revealed by Genome-Wide High Density SNPs Analysis

To better design association studies for complex traits in isolated populations it's important to understand how history and isolation moulded the genetic features of different communities. Population isolates should not “a priori” be considered homogeneous, even if the communities are not distant and part of a small region. We studied a particular area of Sardinia called Ogliastra, characterized by the presence of several distinct villages that display different history, immigration events and population size. Cultural and geographic isolation characterized the history of these communities. We determined LD parameters in 8 villages and defined population structure through high density SNPs (about 360 K) on 360 unrelated people (45 selected samples from each village). These isolates showed differences in LD values and LD map length. Five of these villages show high LD values probably due to their reduced population size and extreme isolation. High genetic differentiation among villages was detected. Moreover population structure analysis revealed a high correlation between genetic and geographic distances. Our study indicates that history, geography and biodemography have influenced the genetic features of Ogliastra communities producing differences in LD and population structure. All these data demonstrate that we can consider each village an isolate with specific characteristics. We suggest that, in order to optimize the study design of complex traits, a thorough characterization of genetic features is useful to identify the presence of sub-populations and stratification within genetic isolates

Combined antiretroviral therapy reduces hyperimmunoglobulinemia in HIV-1 infected children

Objective: To evaluate the effect of combined antiretroviral therapy on serum immunoglobulin (Ig) levels in HIV-1 perinatally infected children. Methods: Data from 1250 children recorded by the Italian Register for HIV Infection in Children from 1985 to 2002 were analysed. Since Ig levels physiologically vary with age, differences at different age periods were evaluated as differences in z-scores calculated using means and standard deviations of normal population for each age period. Combined antiretroviral therapy has become widespread in Italy since 1996, thus differences in Ig z-scores between the periods 1985-1995 and 1996-2002 were analysed. Data according to type of therapeutic regimen were also analysed. Results: Between the two periods 1985-1995 and 1996-2002, significant (P < 0.0001) decreases in IgG (6.29 ± 4.72 versus 4.44 ± 4.33), IgM (9.25 ± 13.32 versus 5.61 ± 7.93), and IgA (10.25 ± 15.68 versus 6.48 ± 11.56) z-scores, together with a parallel significant (P < 0.0001) increase in CD4 T-lymphocyte percentages, were found. These decreases were confirmed regardless of whether the children were receiving intravenous Ig or not. Ig z-scores were significantly higher in children receiving mono-therapy than in those receiving double-combined therapy (IgC, P < 0.0001; IgM, P = 0.003; IgA, P = 0.031) and in the latter children than in those receiving three or more drugs (P < 0.0001 for all z-scores). Ig z-scores correlated inversely with CD4 T-lymphocyte percentages and, directly, with viral loads. Conclusions: Our data show that in HIV-1 infected children combined antiretroviral therapy leads to reduction of hyperimmunoglobulinemia which parallels restoration of CD4 T-lymphocyte percentage and viral load decrease, which it turn probably reflects improved B-lymphocyte functions. © 2004 Lippincott Williams & Wilkins

DTM e interpolazioni in GRASS: applicazione ad un alveo intrecciato

Il presente lavoro affronta lo studio di una metodologia sperimentale che possa essere applicata al monitoraggio a breve e lungo termine di alvei fluviali. Nell’ambito dell’idraulica fluviale infatti, la capacità di predizione dell’evoluzione nel tempo di un corso d’acqua riveste un ruolo fondamentale nella gestione sostenibile della risorsa che esso rappresenta e nella mitigazione del rischio di piena. Un alveo intrecciato è caratterizzato da un sistema multi-canale che si sviluppa in piane alluvionali dando luogo a continue biforcazioni seguite da successive confluenze, e che subisce rilevanti modifiche al passaggio di piene anche di moderata intensità. Questa forte mobilità rende opportuno un monitoraggio frequente nel tempo per prevenire eventuali problemi a manufatti quali protezioni spondali, ponti e infrastrutture tecnologiche quali tubazioni sommerse. Obiettivo del lavoro è ottimizzare il rilevamento di un tratto di alveo di estensione sufficientemente limitata da richiedere il rilievo a terra, per l’acquisizione dei dati necessari alla ricostruzione del Modello Digitale del Terreno (DTM). Si noti che differenti tecniche di rilevamento quali la fotogrammetria e il laser, oltre ad avere costi non ottimali per rilievi di superfici limitate, hanno l’evidente svantaggio di non restituire informazioni riguardo alle zone sommerse. L’occasione della progettazione di un monitoraggio di un tratto del torrente Borbera (Al) ha portato ad affrontare lo studio delle problematiche legate all’interpolazione, cercando una strategia per ridurre il numero di punti da rilevare in campagna, individuando metodi di interpolazione, strutture di dati e dislocazioni ottimali al fine di riprodurre le forme principali di superfici così complesse. A tal fine sono stati utilizzati un DTM sintetico ed uno reale, rappresentanti un breve tratto di un alveo intrecciato, dai quali sono state estratte diverse distribuzioni di punti per simulare l'acquisizione delle osservazioni in campagna. Si è poi proceduto all’interpolazione per mezzo di tre diversi metodi presenti nel GIS open source GRASS. Dal confronto tra i DTM ottenuti mediante interpolazione e quelli iniziali, sono state individuate indicazioni utili per la produzione di modelli digitali del terreno che bene descrivano la morfologia di un alveo intrecciato con il minor dispendio di energia possibile