883 research outputs found

    Improving predictive power of physically based rainfall-induced shallow landslide models: a probabilistic approach

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    Distributed models to forecast the spatial and temporal occurrence of rainfall-induced shallow landslides are based on deterministic laws. These models extend spatially the static stability models adopted in geotechnical engineering, and adopt an infinite-slope geometry to balance the resisting and the driving forces acting on the sliding mass. An infiltration model is used to determine how rainfall changes pore-water conditions, modulating the local stability/instability conditions. A problem with the operation of the existing models lays in the difficulty in obtaining accurate values for the several variables that describe the material properties of the slopes. The problem is particularly severe when the models are applied over large areas, for which sufficient information on the geotechnical and hydrological conditions of the slopes is not generally available. To help solve the problem, we propose a probabilistic Monte Carlo approach to the distributed modeling of rainfall-induced shallow landslides. For the purpose, we have modified the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Analysis (TRIGRS) code. The new code (TRIGRS-P) adopts a probabilistic approach to compute, on a cell-by-cell basis, transient pore-pressure changes and related changes in the factor of safety due to rainfall infiltration. Infiltration is modeled using analytical solutions of partial differential equations describing one-dimensional vertical flow in isotropic, homogeneous materials. Both saturated and unsaturated soil conditions can be considered. TRIGRS-P copes with the natural variability inherent to the mechanical and hydrological properties of the slope materials by allowing values of the TRIGRS model input parameters to be sampled randomly from a given probability distribution. [..]Comment: 25 pages, 14 figures, 9 tables. Revised version; accepted for publication in Geoscientific Model Development on 13 February 201

    TAS2R38 is a novel modifer gene in patients with cystic fbrosis

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    The clinical manifestation of cystic fbrosis (CF) is heterogeneous also in patients with the same cystic fbrosis transmembrane regulator (CFTR) genotype and in afected sibling pairs. Other genes, inherited independently of CFTR, may modulate the clinical manifestation and complications of patients with CF, including the severity of chronic sinonasal disease and the occurrence of chronic Pseudomonas aeruginosa colonization. The T2R38 gene encodes a taste receptor and recently its functionality was related to the occurrence of sinonasal diseases and upper respiratory infections. We assessed the T2R38 genotype in 210 patients with CF and in 95 controls, relating the genotype to the severity of sinonasal disease and to the occurrence of P. aeruginosa pulmonary colonization. The frequency of the PAV allele i.e., the allele associated with the high functionality of the T2R38 protein, was signifcantly lower in i) CF patients with nasal polyposis requiring surgery, especially in patients who developed the complication before 14 years of age; and ii) in CF patients with chronic pulmonary colonization by P. aeruginosa, especially in patients who were colonized before 14 years of age, than in control subjects. These data suggest a role for T2R38 as a novel modifer gene of sinonasal disease severity and of pulmonary P. aeruginosa colonization in patients with CF

    Arothron: an R package for virtual anthropology to build endocast and to perform digital reconstruction

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    Arothron is an R package [1] containing brand new tools for geometric morphometric analysis. The package comes with examples pertaining to the field of virtual anthropology, yet it is addressed to the entire audience of geometric morphometricians. The functions embedded in the package allow aligning disarticulated parts belonging to a single specimen (i.e. broken skull fragments), to build internal cavities such as endocasts, and to reproduce and analyse the shapes of three-dimensional objects. Arothron functions import and export landmark coordinates and 3D paths into ’landmarkAscii’ and ’am’ format files. The Digital Tool for Alignment (DTA) is a landmark-based methodology which allows aligning two or more portions of a 3D mesh (i.e. a disarticulated model, DM) by using a reference sample or model (RM) for comparison. To run DTA, a set of anatomical landmarks is defined on two separated portions of the DM. Each point of the landmark sets is moved to the nearest vertex of the triangles. This way, each landmark is identified by a number corresponding to a row of the vertex matrix of the mesh and its position is tracked on the 3D models moved in the Cartesian coordinate system.The second step is the alignment via Generalized Procrustes Analysis (GPA) of each part of the DM on each RM of the comparative sample, where the same landmark configuration as with the DM has been previously defined. The items of the reference sample are previously scaled to the mean of the single scale factors calculated for each half of the DM, separately, and symmetrized via reflection and relabelling, thereby producing a perfectly symmetrical, bilateral, and scaled landmark configurations (to avoid alignment error as introduced by asymmetry). The last step consists in the quantification of the morphological (Euclidean) distances between each part of the DM and the corresponding landmark configurations on each item in the RM set. Computer-Aided Laser Scanner Emulator (CA-LSE) and Automatic Segmentation Tool for 3D objects (AST-3D) are two new tools designed for the reconstruction of virtual cavities and external shapes [2]. CA-LSE provides the reconstruction of the external portions of a 3D mesh by simulating the action of a laser scanner. AST-3D performs the digital reconstruction of anatomical cavities as endocasts. Both tools use the definition of points of views that can be placed externally to the object (CA-LSE) or inside the object (AST-3D). By applying these tools is possible in few minutes to build virtual cavities as endocast, maxillary sinuses and trabecular bone. In the Arothron R package, we supplied three examples of reconstructing: the dental pulp cavity within a deciduous Neanderthal tooth, the network of blood vessels within a human malleus bone, and an endocast of a human skull.The tools could be used in virtual anthropology application.The digital alignment tool is efficient in find ideal alignments of broken pieces. It could be applied as the first step in virtual reconstruction on human fossil specimens that often consist of a disarticulated fragments such as BOU-VP12/130 (Australopithecus garhi), AL-442 (Australopithecus afarensis), OH5 (Paranthropus boisei), ATD6-15 and ATD6-69 (Homo antecessor), Amud 1 (Homo neanderthalensis), Le Moustier 1 (Homo neanderthalensis). The easily and quickly use of the Arothron R package to build virtual cavities may provide a new means largely applicable in virtual Anthropology. References:[1] Profico A., Veneziano A., Melchionna M., Piras P. & Raia P., 2018. Arothron: Geometric Morphometrics Analyses. R package version 1.0.1, developer version available at https://github/Arothron DOI:10.5281/zenodo.1218712.[2] Profico A., Schlager S., Valoriani V., Buzi C., Melchionna M., Veneziano A., Raia P., MoggifiCecchi J. & Manzi G., 2018. Reproducing the internal and external anatomy of fossil bones: Two new automatic digital tools. American Journal of Physical Anthropology

    Essaouria, Morocco : redevelopment through the introduction of a university

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1996.Includes bibliographical references (leaves 66-67).This thesis addresses the urban redevelopment of Essaouira, Morocco as it relates to its economy, urban tissue and cultural identity. As architects we herald the importance of context; a loaded term which describes an environment, built and natural, habits of people and local traditions, all attributes which play a vital role in the development of a design strategy. Interestingly when context becomes culturally unfamiliar architects struggle to characterize the attributes which define that specific context. In selecting Essaouira one of my goals is to develop a methodology towards understanding a context. This thesis attempts to reveal the past, present and future attributes which define Essaouira after which provide a synthesis for the redevelopment of Essaouira through the introduction of a university. The thesis commences with an analytical study of Essaouira, including historical development, development policy, migration patterns, building typologies, land use, pedestrian and vehicular movement and present conditions. It is safe to say that in my two visits to Essaouira I have walked down every street both in the old and new sections of the city and have begun to establish an intuitive sense of the city. While the analytic and synthetic aspects may appear quite independent from one another, in fact the thesis developed through a meandering back and forth between the two, providing questions, then answers and questions once more.by Joseph M. Raia.M.S

    Successful isolation of viable adipose-derived stem cells from human adipose tissue subject to long-term cryopreservation: positive implications for adult stem cell-based therapeutics in patients of advanced age.

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    We examined cell isolation, viability, and growth in adipose-derived stem cells harvested from whole adipose tissue subject to different cryopreservation lengths (2-1159 days) from patients of varying ages (26-62 years). Subcutaneous abdominal adipose tissue was excised during abdominoplasties and was cryopreserved. The viability and number of adipose-derived stem cells isolated were measured after initial isolation and after 9, 18, and 28 days of growth. Data were analyzed with respect to cryopreservation duration and patient age. Significantly more viable cells were initially isolated from tissue cryopreserved2 years, irrespective of patient age. However, this difference did not persist with continued growth and there were no significant differences in cell viability or growth at subsequent time points with respect to cryopreservation duration or patient age. Mesenchymal stem cell markers were maintained in all cohorts tested throughout the duration of the study. Consequently, longer cryopreservation negatively impacts initial live adipose-derived stem cell isolation; however, this effect is neutralized with continued cell growth. Patient age does not significantly impact stem cell isolation, viability, or growth. Cryopreservation of adipose tissue is an effective long-term banking method for isolation of adipose-derived stem cells in patients of varying ages

    Whole-body composition features by computed tomography in ovarian cancer: pilot data on survival correlations

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    Background: The primary objective of this study was to assess the associations of computed tomography (CT)-based whole-body composition values with overall survival (OS) and progression-free survival (PFS) in epithelial ovarian cancer (EOC) patients. The secondary objective was the association of body composition with chemotherapy-related toxicity. Methods: Thirty-four patients (median age 64.9 years; interquartile range 55.4–75.4) with EOC and thorax and abdomen CT scans were included. Clinical data recorded: age; weight; height; stage; chemotherapy-related toxicity; and date of last contact, progression and death. Automatic extraction of body composition values was performed by dedicated software. Sarcopenia was defined according to predefined cutoffs. Statistical analysis included univariate tests to investigate associations of sarcopenia and body composition with chemotoxicity. Association of body composition parameters and OS/PFS was evaluated by log-rank test and Cox proportional hazard model. Multivariate models were adjusted for FIGO stage and/or age at diagnosis. Results: We found significant associations of skeletal muscle volume with OS (p = 0.04) and PFS (p = 0.04); intramuscular fat volume with PFS (p = 0.03); and visceral adipose tissue, epicardial and paracardial fat with PFS (p = 0.04, 0.01 and 0.02, respectively). We found no significant associations between body composition parameters and chemotherapy-related toxicity. Conclusions: In this exploratory study, we found significant associations of whole-body composition parameters with OS and PFS. These results open a window to the possibility to perform body composition profiling without approximate estimations

    Body composition as a predictor of chemotherapy-related toxicity in ovarian cancer patients: a systematic review

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    Objectives:The main objective of this systematic review was to examine the literature evaluating association of image-based body composition with chemotherapy-related toxicity in ovarian cancer patients. A secondary objective was to evaluate the different definitions of sarcopenia across studies. Methods:This systematic review was conducted according to the PRISMA-DTA statement and the protocol was registered on Prospero. A comprehensive literature search of 3 electronic databases was performed by two authors. For each eligible article, information was collected concerning the clinical setting; basic study data; population characteristics; technical aspects; body composition features; chemotherapy drugs administered; association of body composition values and toxicities. The overall quality of the included studies was critically evaluated. Results:After the initial retrieval of 812 articles, the systematic review included 6 articles (5/6 studies were retrospective; one was prospective). The number of patients ranged between 69 and 239; mean/median age ranged between 55 and 65 years; the percentage of sarcopenic patients ranged between 25% and 54%. The cut-off values to define sarcopenia and the vertebral levels for evaluation of body composition were different. Five studies included chemotherapy based on carboplatin and paclitaxel, 1 included chemotherapy based on pegylated liposomal doxorubicin. Among the studies including carboplatin and paclitaxel, 3/5 demonstrated an association with toxicity, whereas 2/5 did not. Altogether, 4/6 papers demonstrated an association between the body composition values and the development of chemotherapy-related toxicities. Conclusions:There is a wide variability of results about the association of body composition and chemotherapy-related toxicity in ovarian cancer patients. Therefore further studies, possibly including a comprehensive assessment of body compartments and where the definition of body composition cut-offs is constant, are warranted to better understand this association
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