106 research outputs found
Surgical management of penetrating pulmonary injuries
Chest injuries were reported as early as 3000 BC in the Edwin Smith Surgical Papyrus. Ancient Greek chronicles reveal that they had anatomic knowledge of the thoracic structures. Even in the ancient world, most of the therapeutic modalities for chest wounds and traumatic pulmonary injuries were developed during wartime
Shared latent structures between imaging features and biomarkers in early stages of Alzheimer's disease: a predictive study
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Magnetic resonance imaging (MRI) provides high resolution brain morphological information and is used as a biomarker in neurodegenerative diseases. Population studies of brain morphology often seek to identify pathological structural changes related to different diagnostic categories (e.g: controls, mild cognitive impairment or dementia) which normally describe highly heterogeneous groups with a single categorical variable. Instead, multiple biomarkers are used as a proxy for pathology and are more powerful in capturing structural variability. Hence, using the joint modeling of brain morphology and biomarkers, we aim at describing structural changes related to any brain condition by means of few underlying processes. In this regard, we use a multivariate approach based on Projection to Latent Structures in its regression variant (PLSR) to study structural changes related to aging and AD pathology. MRI volumetric and cortical thickness measurements are used for brain morphology and cerebrospinal fluid (CSF) biomarkers (t-tau, p-tau and amyloid-beta) are used as a proxy for AD pathology. By relating both sets of measurements, PLSR finds a low-dimensional latent space describing AD pathological effects on brain structure. The proposed framework allows to separately model aging effects on brain morphology as a confounder variable orthogonal to the pathological effect. The predictive power of the associated latent spaces (i.e. the capacity of predicting biomarker values) is assessed in a cross-validation framework.Peer ReviewedPostprint (author's final draft
Projection to latent spaces disentangles pathological effects on brain morphology in the asymptomatic phase of Alzheimer's disease
Alzheimer's disease (AD) continuum is defined as a cascade of several neuropathological processes that can be measured using biomarkers, such as cerebrospinal fluid (CSF) levels of Aß, p-tau, and t-tau. In parallel, brain anatomy can be characterized through imaging techniques, such as magnetic resonance imaging (MRI). In this work we relate both sets of measurements and seek associations between biomarkers and the brain structure that can be indicative of AD progression. The goal is to uncover underlying multivariate effects of AD pathology on regional brain morphological information. For this purpose, we used the projection to latent structures (PLS) method. Using PLS, we found a low dimensional latent space that best describes the covariance between both sets of measurements on the same subjects. Possible confounder effects (age and sex) on brain morphology are included in the model and regressed out using an orthogonal PLS model. We looked for statistically significant correlations between brain morphology and CSF biomarkers that explain part of the volumetric variance at each region-of-interest (ROI). Furthermore, we used a clustering technique to discover a small set of CSF-related patterns describing the AD continuum. We applied this technique to the study of subjects in the whole AD continuum, from the pre-clinical asymptomatic stages all the way through to the symptomatic groups. Subsequent analyses involved splitting the course of the disease into diagnostic categories: cognitively unimpaired subjects (CU), mild cognitively impaired subjects (MCI), and subjects with dementia (AD-dementia), where all symptoms were due to AD.This work has been partially supported by the project MALEGRA TEC2016-75976-R financed by the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (ERDF). AC was supported by the Spanish Ministerio de Educación, Cultura y Deporte FPU Research Fellowship. JG holds a Ramón y Cajal fellowship (RYC-2013-13054).Peer ReviewedPostprint (published version
Projection to latent spaces disentangles specific cerebral morphometric patterns associated to aging and preclinical AD”,
Peer ReviewedPostprint (published version
Uso de fisioterapia combinada con geles y extractos a base de lignanos de jarilla y capsaicina aplicado en dolor articular
La presente investigación, basándose en las características desinflamatoria
y analgésica de la jarilla y la capsaicina respectivamente, realizará
extractos para aplicarlos sobre la zona del dolor a través de iontoforesis.
La facultad de Farmacia y Bioquímica es la encargada de recolectar las
especies de Larrea divaricata, Larrea nitida y Larrea cuneifolia, con la finalidad
de realizar extracciones de lignanos destinados a la formulación
de geles. También reproducirá la genética del Capsicum chacoense Hun
(denominado vulgarmente “arivivi”) para la formulación de extractos. La
facultad de Kinesiología y Fisioterapia tiene a su cargo la selección de las
unidades de análisis, aplicando un diseño de investigación experimental,
del tipo cuasi experimental, con presencia de grupo control y otro experimental,
al cual se le realizarán las aplicaciones de iontoforesis con dichos
extractos en búsqueda de la remitencia del dolor, en grupos que ya vienen formados de antemano
MRI-based screening of preclinical Alzheimer's disease for prevention clinical trials
The final publication is available at IOS Press through http://dx.doi.org/10.3233/JAD-180299”.The identification of healthy individuals harboring amyloid pathology represents one important challenge for secondary prevention clinical trials in Alzheimer’s disease (AD). Consequently, noninvasive and cost-efficient techniques to detect preclinical AD constitute an unmet need of critical importance. In this manuscript, we apply machine learning to structural MRI (T1 and DTI) of 96 cognitively normal subjects to identify amyloid-positive ones. Models were trained on public ADNI data and validated on an independent local cohort. Used for subject classification in a simulated clinical trial setting, the proposed method is able to save 60% of unnecessary CSF/PET tests and to reduce 47% of the cost of recruitment. This recruitment strategy capitalizes on available MR scans to reduce the overall amount of invasive PET/CSF tests in prevention trials, demonstrating a potential value as a tool for preclinical AD screening. This protocol could foster the development of secondary prevention strategies for AD.Peer ReviewedPostprint (author's final draft
Especies de Pythium asociadas al cultivo de maíz en la Provincia de Buenos Aires : resultados preliminares
Fil: Grijalba, Pablo Enrique. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Fil: Palmucci, Hemilse Elena. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Fil: Pucheta, Juan Alberto. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Fil: Petrone, Estela P. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Fil: Belfiori, Juan. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Pythium spp. causa pudriciones radiculares en el cultivo de maíz en todo el mundo, ocasionando clorosis y marchitamiento de la parte aérea. Entre 2018 y 2020 se efectuaron recorridas en lotes de producción de maíz de la zona norte de la provincia de Buenos Aires, en estadios V1-V3. Se recolectaron muestras de plántulas enfermas y suelo, para aislar e identificar las especies de Pythium asociadas al cultivo de maíz durante su implantación y primeros estadios del cultivo. Para obtener aislamientos a partir de plántulas, muestras de tejidos con síntomas se sembraron en medio de cultivo con el agregado de antibióticos y fungicidas. Para obtener aislamientos a partir de suelos, se utilizó la técnica denominada “trampa”, con granos de maíz. De cada aislamiento se comprobó la patogenicidad in vitro (cajas de Petri) e in vivo (macetas). Durante la campaña 2018/2019 se obtuvieron 25 aislamientos de las localidades de San Antonio de Areco, Pergamino y Fontezuela, mientras que en la campaña 2019/2020 se efectuaron 18 aislamientos de Chacabuco, Chivilcoy y 25 de Mayo. Los aislamientos de la primera campaña fueron identificados como correspondientes a las especies P. ultimum, P. irregulare y P. sylvaticum. Las cepas evaluadas mostraron diferente grado de patogenicidad (in vitro e in vivo), siendo P. irregulare la de mayor grado seguida de P. ultimum.grafs., fot
High-temperature superconducting screens for magnetic field-error cancellation in accelerator magnets
Accelerators magnets must have minimal magnetic field imperfections to reduce particle-beam instabilities. In the case of coils made of high-temperature superconducting (HTS) tapes, the magnetization due to persistent currents adds an undesired field contribution, potentially degrading the magnetic field quality. In this paper we study the use of superconducting screens based on HTS tapes for reducing the magnetic field imperfections in accelerator magnets. The screens exploit the magnetization by persistent currents to cancel out the magnetic field error. The screens are aligned with the main field component, such that only the undesired field components are compensated. The screens are self-regulating, and do not require any externally applied source of energy. Measurements in liquid nitrogen at 77 K show for dipole-field configurations a significant reduction of the magnetic field error up to a factor of four. The residual error is explained via numerical simulations accounting for the geometric defects in the HTS screens, achieving satisfactory agreement with experimental results. Simulations show that if screens are increased in width and thickness, and operated at 4.5 K, field errors may be eliminated almost entirely for the typical excitation cycles of accelerator magnets
Methods in prosody: A Romance language perspective
This book presents a collection of pioneering papers reflecting current methods in prosody research with a focus on Romance languages. The rapid expansion of the field of prosody research in the last decades has given rise to a proliferation of methods that has left little room for the critical assessment of these methods. The aim of this volume is to bridge this gap by embracing original contributions, in which experts in the field assess, reflect, and discuss different methods of data gathering and analysis. The book might thus be of interest to scholars and established researchers as well as to students and young academics who wish to explore the topic of prosody, an expanding and promising area of study
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