39 research outputs found
Filter optimization and complexity reduction for video coding using graph-based transforms
The basis functions of lifting transform on graphs are completely
determined by finding a bipartition of the graph and defining the
prediction and update filters to be used. In this work we consider the
design of prediction filters that minimize the quadratic prediction error
and therefore the energy of the detail coefficients, which will give
rise to higher energy compaction. Then, to determine the graph bipartition,
we propose a distributed maximum-cut algorithm that significantly
reduces the computational cost with respect to the centralized
version used in our previous work. The proposed techniques
show improvements in coding performance and computational cost
as compared to our previous work.This work was supported in part by NSF under grant CCF-1018977Publicad
Optimized Update/Prediction Assignment for Lifting Transforms on Graphs
Transformations on graphs can provide compact representations of signals with many applications in denoising, feature extraction or compression. In particular, lifting transforms have the advantage of being critically sampled and invertible by construction, but the efficiency of the transform depends on the choice of a good bipartition of the graph into update (U) and prediction (P) nodes. This is the update/prediction (U=P) assignment problem, which is the focus of this paper. We analyze this problem theoretically and derive an optimal U=P assignment under assumptions about signal model and filters. Furthermore, we prove that the best U=P partition is related to the correlation between nodes on the graph and is not the one that minimizes the number of conflicts (connections between nodes of same label) or maximizes the weight of the cut. We also provide experimental results in randomly generated graph signals and real data from image and video signals that validate our theoretical conclusions, demonstrating improved performance over state of the art solutions for this problem.This work was supported in part by NSF under Grant CCF-1018977 and in part by the Spanish Ministry of Economy and Competitiveness under Grants TEC2014-53390-P, TEC2014-52289-R, TEC2016-81900-REDT/AEI and TEC2017-83838-RPublicad
Directional Transforms for Video Coding Based on Lifting on Graphs
In this work we describe and optimize a general scheme based on lifting transforms on graphs for video coding. A graph is constructed to represent the video signal. Each pixel becomes a node in the graph and links between nodes represent similarity between them. Therefore, spatial neighbors and temporal motion-related pixels can be linked, while nonsimilar pixels (e.g., pixels across an edge) may not be. Then, a lifting-based transform, in which filterin operations are performed using linked nodes, is applied to this graph, leading to a 3-dimensional (spatio-temporal) directional transform which can be viewed as an extension of wavelet transforms for video. The design of the proposed scheme requires four main steps: (i) graph construction, (ii) graph splitting, (iii) filte design, and (iv) extension of the transform to different levels of decomposition. We focus on the optimization of these steps in order to obtain an effective transform for video coding. Furthermore, based on this scheme, we propose a coefficien reordering method and an entropy coder leading to a complete video encoder that achieves better coding performance than a motion compensated temporal filterin wavelet-based encoder and a simple encoder derived from H.264/AVC that makes use of similar tools as our proposed encoder (reference software JM15.1 configu ed to use 1 reference frame, no subpixel motion estimation, 16 × 16 inter and 4 × 4 intra modes).This work was supported in part by NSF under grant CCF-1018977 and by Spanish Ministry of Economy and Competitiveness under grants TEC2014-53390-P and TEC2014-52289-R.Publicad
Thoracic limb salvage by fibular free flap
The treatment of most fractures of the ulna and radius is usually performed by anatomical reduction and internal fixation, when damage is extensive and local soft tissue cannot provide a complete wound coverage, locoregional flaps present a suitable reconstructive benefit. A 35-year-old male patient suffered an exposed diaphysio-metaphyseal fracture with multi-fragmented distal radius. The patient was evaluated during a 10-day period at the National Institute of Rehabilitation, where the osteosynthesis material and a severe infectious process with necrosis were identified. Necrosectomy of the posterior compartment and removal of the osteosynthesis material was performed, a skin defect of approximately 22x16 cm was observed with a bone gap of 6 cm of radius and ulna. a fibula-free flap is placed to correct the skin defect and an external fixative used for bone alignment. The fibular free flap presents an excellent therapeutic alternative in the resolution of bone gaps with extensive skin defect. Whenever a trained microsurgery team is available, current scales of limb injury should be considered but not utilized for therapeutic approach, always trying to shift amputation as the first option, to the very last one of them
Lymphangioleiomyomatosis: Searching for potential biomarkers
Biomarkers; Lymphangioleiomyomatosis; MetalloproteinasesBiomarcadores; Linfangioleiomiomatosis; MetaloproteinasasBiomarcadors; Limfangioleiomiomatosi; MetaloproteinasesBackground: Vascular endothelial growth factor-D (VEGF-D) is the most commonly used biomarker for diagnosing lymphangioleiomyomatosis (LAM). However, lung biopsy is often necessary as well; therefore, defining new biomarkers for LAM is crucial. The aim of this study was to describe the diagnostic accuracy of a variety of biomarkers.
Methods: We assessed 13 analytes in serum related to extracellular matrix remodeling, lymphatic involvement and angiogenesis in a cohort of patients with LAM, comparing them with patients with other cystic lung diseases (OCLD) and healthy women. A scoring method based on the cut-point of each VEGF-D and metalloproteinase-2 (MMP-2) was used to evaluate the diagnostic performance of the marker combination.
Results: A total of 97 subjects were recruited: 59 (61%) LAM patients, 18 (19%) OCLD patients, and 20 (20%) healthy female controls. MMP-2 was the only extracellular matrix remodeling biomarker able to differentiate LAM patients from OCLD and healthy patients. Serum MMP-2 was higher in LAM patients [median 578 (465–832) ng/ml] than in patients with OCLD and healthy controls [medians 360 (314–546) and 427 (365–513) ng/ml, respectively (p < 0.0001)]. The area under ROC curve (AUC) of MMP-2 was 0.785 and that of VEGF-D 0.815 (p = 0.6214). The sensitivity/specificity profiles of each biomarker (54/92% for MMP-2, 59/95% for VEGF-D) yielded a composite score (−6.36 + 0.0059 × VEGF-D + 0.0069 × MMP-2) with higher accuracy than each component alone (AUC 0.88 and sensitivity/specificity 79/87%).
Conclusion: Combining MMP-2 and VEGF-D may increase diagnostic accuracy for LAM.This project was supported by the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR), grant number: PI 638/2018. The funders have no role in study design, data and analysis collection, decision to publish, or preparation of the manuscript
Lymphangioleiomyomatosis biomarkers linked to lung metastatic potential and cell stemness
Lymphangioleiomyomatosis (LAM) is a rare lung-metastasizing neoplasm caused by the proliferation of smooth muscle-like cells that commonly carry loss-of-function mutations in either the tuberous sclerosis complex 1 or 2 (TSC1 or TSC2) genes. While allosteric inhibition of the mechanistic target of rapamycin (mTOR) has shown substantial clinical benefit, complementary therapies are required to improve response and/or to treat specific patients. However, there is a lack of LAM biomarkers that could potentially be used to monitor the disease and to develop other targeted therapies. We hypothesized that the mediators of cancer metastasis to lung, particularly in breast cancer, also play a relevant role in LAM. Analyses across independent breast cancer datasets revealed associations between low TSC1/2 expression, altered mTOR complex 1 (mTORC1) pathway signaling, and metastasis to lung. Subsequently, immunohistochemical analyses of 23 LAM lesions revealed positivity in all cases for the lung metastasis mediators fascin 1 (FSCN1) and inhibitor of DNA binding 1 (ID1). Moreover, assessment of breast cancer stem or luminal progenitor cell biomarkers showed positivity in most LAM tissue for the aldehyde dehydrogenase 1 (ALDH1), integrin-ß3 (ITGB3/CD61), and/or the sex-determining region Y-box 9 (SOX9) proteins. The immunohistochemical analyses also provided evidence of heterogeneity between and within LAM cases. The analysis of Tsc2-deficient cells revealed relative over-expression of FSCN1 and ID1; however, Tsc2-deficient cells did not show higher sensitivity to ID1-based cancer inhibitors. Collectively, the results of this study reveal novel LAM biomarkers linked to breast cancer metastasis to lung and to cell stemness, which in turn might guide the assessment of additional or complementary therapeutic opportunities for LAM
Usos del e‐learning en las Universidades Andaluzas: estado de la situación y análisis de buenas prácticas. (Resumen ejecutivo).
Secretaría General de Universidades, Investigación y Tecnología P07-SE-J.0267
Usos del e-learning en las Universidades Andaluzas: Estado de la situación y análisis de buenas prácticas. (Versión completa)
Secretaría General de Universidades, Investigación y Tecnología P07-SE-J.0267
Anafilaxia en niños y adultos: prevención, diagnóstico y tratamiento
La anafilaxia es una condición que requiere asistencia inmediata para su resolución, se puede presentar en diferentes entornos: consultorio, hospital, escuela, hogar o en algún otro espacio público. La información aquí contenida forma parte de lineamientos conocidos sobre prevención, diagnóstico y tratamiento. Se abordan aspectos epidemiológicos, desencadenantes, factores de
riesgo y cofactores; se explican de una manera didáctica los mecanismos fisiopatológicos que se traducen en fenotipos de presentación. Se enfatiza el diagnóstico clínico con base en criterios ya establecidos, se mencionan clasificaciones para evaluar la gravedad de la reacción, así como el rol de las pruebas clínicas o de laboratorio. Como aspectos de relevancia, se abordan el tratamiento de primera elección con adrenalina, instrucciones sobre autoinyectores y diferentes elementos para el tratamiento complementario y de segunda elección. También se refieren aspectos a considerar al dar de alta a un paciente y medidas de seguimiento, con un énfasis preventivo en la comunidad. Finalmente, se menciona el abordaje en el consultorio de alergia para decidir sobre opciones de inmunomodulación.
ABSTRACT
Anaphylaxis is a condition that requires immediate assistance for its resolution, it can occur in different
settings: office, hospital, school, home or some other public space. The information contained herein
forms part of known guidelines on prevention, diagnosis and treatment. Epidemiological aspects,
triggers, risk factors and co-factors are addressed; physiopathological mechanisms that are translated
into presentation phenotypes are explained in a didactic way. Clinical diagnosis is emphasized based
on established criteria, classifications are mentioned to evaluate the severity of the reaction, as well as
the role of clinical or laboratory tests. As relevant aspects, the first choice treatment with adrenaline,
instructions on auto-injectors and different elements for the complementary and second choice
treatment are dealt with. They also refer to aspects to consider when discharging a patient and followup measures, with a preventive emphasis on the community. Finally, the allergy clinic approach to
deciding on immunomodulation options is mentione
Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)
Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters.
Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs).
Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001).
Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio