1,032 research outputs found

    Dimensionality Reduction in images for Appearance-based camera Localization

    Get PDF
    Appearance-based Localization (AL) focuses on estimating the pose of a camera from the information encoded in an image, treated holistically. However, the high-dimensionality of images makes this estimation intractable and some techniques of Dimensionality Reduction (DR) must be applied. The resulting reduced image representation, though, must keep underlying information about the structure of the scene to be able to infer the camera pose. This work explores the problem of DR in the context of AL, and evaluates four popular methods in two simple cases on a synthetic environment: two linear (PCA and MDS) and two non-linear, also known as Manifold Learning methods (LLE and Isomap). The evaluation is carried out in terms of their capability to generate lower-dimensional embeddings that maintain underlying information that is isometric to the camera poses.Plan propio UMA, HOUNDBOT (P20 01302), funding by Andalusian Regional Government, and ARPEGGIO (PID2020-117057GB-I00), funded by Spain National Research Agency. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Millimeter-Wave Line Ratios and Sub-beam Volume Density Distributions

    Full text link
    We explore the use of mm-wave emission line ratios to trace molecular gas density when observations integrate over a wide range of volume densities within a single telescope beam. For observations targeting external galaxies, this case is unavoidable. Using a framework similar to that of Krumholz and Thompson (2007), we model emission for a set of common extragalactic lines from lognormal and power law density distributions. We consider the median density of gas producing emission and the ability to predict density variations from observed line ratios. We emphasize line ratio variations, because these do not require knowing the absolute abundance of our tracers. Patterns of line ratio variations have the prospect to illuminate the high-end shape of the density distribution, and to capture changes in the dense gas fraction and median volume density. Our results with and without a high density power law tail differ appreciably; we highlight better knowledge of the PDF shape as an important area. We also show the implications of sub-beam density distributions for isotopologue studies targeting dense gas tracers. Differential excitation often implies a significant correction to the naive case. We provide tabulated versions of many of our results, which can be used to interpret changes in mm-wave line ratios in terms of changes in the underlying density distributions.Comment: 24 pages, 16 figure, Accepted for publication in the Astrophysical Journal, two online tables temporarily available at http://www.astronomy.ohio-state.edu/~leroy.42/densegas_table2.txt and http://www.astronomy.ohio-state.edu/~leroy.42/densegas_table3.tx

    Use of sponge-assisted endoluminal vacuum therapy for the treatment of colorectal anastomotic leaks: expert panel consensus

    Get PDF
    Colorectal anastomotic leaks; Endoluminal vacuum therapyFugas anastomóticas colorrectales; Terapia de vacío endoluminalFuites anastomòtiques colorectals; Teràpia de buit endoluminalBackground Anastomotic leaks represent one of the most significant complications of colorectal surgery and are the primary cause of postoperative mortality and morbidity. Sponge-assisted endoluminal vacuum therapy (EVT) has emerged as a minimally invasive technique for the management of anastomotic leaks; however, there are questions regarding patient selection due to the heterogeneous nature of anastomotic leaks and the application of sponge-assisted EVT by surgeons. Method Seven colorectal surgical experts participated in a modified nominal group technique to establish consensus regarding key questions that arose from existing gaps in scientific evidence and the variability in clinical practice. After a bibliographic search to identify the available evidence and sequential meetings with participants, a series of recommendations and statements were formulated and agreed upon. Results Thirty-seven recommendations and statements on the optimal use of sponge-assisted EVT were elaborated on and unanimously agreed upon by the group of experts. The statements and recommendations answer 10 key questions about the indications, benefits, and definition of the success rate of sponge-assisted EVT for the management of anastomotic leaks. Conclusion Although further research is needed to resolve clinical and technical issues associated with sponge-assisted EVT, the recommendations and statements produced from this project summarize critical aspects to consider when using sponge-assisted EVT and to assist those involved in the management of patients with colorectal anastomotic leaks.This project was supported by B. Braun Surgical SAU

    COVID-19 e o olho: quanto sabemos realmente? Uma revisão das melhores evidências

    Get PDF
    To identify and classify available information regarding COVID-19 and eye care according to the level of evidence, within four main topics of interest: evidence of the virus in tears and the ocular surface, infection via the conjunctival route, ocular manifestations, and best practice recommendations. A structured review was conducted in PubMed, ScienceDirect, LILACS, SciELO, the Cochrane Library and Google Scholar on COVID-19 and ophthalmology. The Oxford Centre for Evidence Based Medicine 2011 Levels of Evidence worksheet was used for quality assessments. 1018 items were identified in the search; 26 records were included in the qualitative synthesis, which encompassed 6 literature reviews, 10 case series or cross-sectional studies, 4 case reports, and 6 intervention descriptions. Seventeen out of 26 records (65%) were categorized as level 5 within the Oxford CBME methodology grading system, the rest were level 4. The evidence generated on COVID-19 and ophthalmology to date is limited, although this is understandable given the circumstances. Both the possible presence of viral particles in tears and conjunctiva, and the potential for conjunctival transmission remain controversial. Ocular manifestations are not frequent and could resemble viral infection of the ocular surface. Most recommendations are based on the strategies implemented by Asian countries during previous coronavirus outbreaks. There is a need for substantive studies evaluating these strategies in the setting of SARS-CoV-2. In the meantime, plans for applying these measures must be implemented with caution, taking into account the context of each individual country, and undergo regular evaluation.Identificar e classificar as informações disponíveis sobre o COVID-19 e o tratamento oftalmológico de acordo com o nível de evidência, dentro de quatro tópicos principais de interesse: evidência do vírus nas lágrimas e na superfície ocular, infecção pela via conjuntival, manifestações oculares e recomendações de melhores práticas. Foi realizada uma revisão estruturada no PubMed, ScienceDirect, LILACS, SciELO, Biblioteca Cochrane e Google Scholar no COVID-19 e oftalmologia. A planilha de Níveis de Evidência 2011 do Oxford Centre for Evidence Based Medicine 2011 foi usada para avaliações de qualidade. Mil e dezoito itens foram identificados na busca; Foram incluídos 26 registros na síntese qualitativa, que incluiu 6 revisões de literatura, 10 séries de casos ou estudos transversais, 4 relatos de casos e 6 descrições de intervenções. Dezessete dos 26 registros (65%) foram classificados como nível 5 no sistema de classificação da metodologia Oxford CBME, o restante foi no nível 4. As evidências geradas no COVID-19 e na oftalmologia até o momento são limitadas, embora isso seja compreensível dadas as circunstâncias. Tanto a possível presença de partículas virais em lágrimas e conjuntiva quanto o potencial de transmissão conjuntival permanecem controversos. As manifestações oculares não são frequentes e podem se assemelhar a infecção viral da superfície ocular. A maioria das recomendações baseia-se nas estratégias implementadas pelos países asiáticos durante surtos anteriores de coronavírus. Há necessidade de estudos aprofundados avaliando essas estratégias no cenário da SARS-CoV-2. Enquanto isso, os planos para a aplicação dessas medidas devem ser implementados com cautela, levando em consideração o contexto de cada país e submetidos a auditorias periódicas

    From the North-Iberian Margin to the Alboran Basin: A lithosphere geo-transect across the Iberian Plate

    Get PDF
    A ~ 1000-km-long lithospheric transect running from the North-Iberian Margin to the Alboran Basin (W-Mediterranean) is investigated. The main goal is to image the changes in the crustal and upper mantle structure occurring in: i) the North-Iberian margin, whose deformation in Alpine times gave rise to the uplift of the Cantabrian Mountains related to Iberia-Eurasia incipient subduction; ii) the Spanish Meseta, characterized by the presence of Cenozoic basins on top of a Variscan basement with weak Alpine deformation in the Central System, and localized Neogene-Quaternary deep volcanism; and iii) the Betic-Alboran system related to Africa-Iberia collision and the roll-back of the Ligurian-Tethyan domain. The modeling approach, combines potential fields, elevation, thermal, seismic, and petrological data under a self-consistent scheme. The crustal structure is mainly constrained by seismic data whereas the upper mantle is constrained by tomographic models. The results highlight the lateral variations in the topography of the lithosphere-asthenosphere boundary (LAB), suggesting a strong lithospheric mantle strain below the Cantabrian and Betic mountain belts. The LAB depth ranges from 180 km beneath the Cantabrian Mountains to 135-110. km beneath Iberia Meseta deepening again to values of 160. km beneath the Betic Cordillera. The Central System, with a mean elevation of 1300. m, has a negligible signature on the LAB depth. We have considered four lithospheric mantle compositions: a predominantly average Phanerozoic in the continental mainland, two more fertile compositions in the Alboran Sea and in the Calatrava Volcanic Province, and a hydrated uppermost mantle in the North-Iberian Margin. These compositional differences allowed us to reproduce the main trends of the geophysical observables as well as the inferred P- and S-wave seismic velocities from tomography models and seismic experiments available in the study transect. The high mean topography of Iberia can be partly consistent with a low-velocity/high-temperature/low-density layer in the sublithospheric mantle.The presented work has been supported by Topo-Iberia Consolider-IngenioCSD2006-0004, GASAM/TopoMed (CGL2008-03474-E/BTE/07-TOPO-EUROPE-FP-006), TECLA (CGL2011-26670) funded by the Spanish Government, and PYRTEC-IP2 (SV-PA-10-03, funded by the Government of Asturias/ESF TOPO-EUROPE Programme) projects. AC benefitted from a JAE-PreCP grant from CSIC. JCA acknowledges the support from ARC GrantDP120102372.Peer Reviewe

    Clinical impact of the ERBP Working Group 2010 Recommendations for the anemia management in chronic kidney disease not on dialysis: ACERCA study.

    Get PDF
    BACKGROUND AND OBJECTIVE: The Anemia Working Group of ERBP in 2010 recommended a target hemoglobin (Hb) level in the range of 11-12 g/dL, without intentionally exceeding 13 g/dL during the treatment with erythropoiesis stimulating agents (ESAs). This study evaluated if there was a clinical impact of this statement in the anemia management of chronic kidney disease (CKD) patients treated with ESAs not on dialysis in routine clinical practice in Spain. METHODS: This was an observational and cross-sectional study carried out in CKD patients not on dialysis in Spain who initiated ESA treatment (naïve), or were shifted from a previous ESA to another ESAs (converted) since January 2011. RESULTS: Of 441 patients evaluated, 67.6% were naïve and 32.4% were converted. At the study visit, 42.5% of naïve patients achieved the Hb target of 11-12 g/dL, with a mean Hb of 11.3±1.3 g/dL (vs 10.1±0.9 g/dL at the start of ESA therapy). Only 35.3% of converted patients maintained Hb levels within the recommended target at the study visit. Yet, 8.2% of naïve patients and 7.9% of those converted had Hb levels >13 g/dL. Hb levels were similar across subgroups of patients, regardless of the presence of significant comorbidities. CONCLUSIONS: Anemia management in CKD patients treated with ESAs by Spanish nephrologists seems to be aimed at preventing Hb levels <11 g/dL, while <50% of patients were within the narrow recommended Hb target range. This, together with the lack of individualization in Hb targets according to patients' comorbidities show that there is still room for improvement in renal anemia management in the clinical setting

    Quantitative detection of iodine in the stratosphere

    Get PDF
    Oceanic emissions of iodine destroy ozone, modify oxidative capacity, and can form new particles in the troposphere. However, the impact of iodine in the stratosphere is highly uncertain due to the lack of previous quantitative measurements. Here, we report quantitative measurements of iodine monoxide radicals and particulate iodine (Iy,part) from aircraft in the stratosphere. These measurements support that 0.77 ± 0.10 parts per trillion by volume (pptv) total inorganic iodine (Iy) is injected to the stratosphere. These high Iy amounts are indicative of active iodine recycling on ice in the upper troposphere (UT), support the upper end of recent Iy estimates (0 to 0.8 pptv) by the World Meteorological Organization, and are incompatible with zero stratospheric iodine injection. Gasphase iodine (Iy,gas) in the UT (0.67 ± 0.09 pptv) converts to Iy,part sharply near the tropopause. In the stratosphere, IO radicals remain detectable (0.06 ± 0.03 pptv), indicating persistent Iy,part recycling back to Iy,gas as a result of active multiphase chemistry. At the observed levels, iodine is responsible for 32% of the halogen-induced ozone loss (bromine 40%, chlorine 28%), due primarily to previously unconsidered heterogeneous chemistry. Anthropogenic (pollution) ozone has increased iodine emissions since preindustrial times (ca. factor of 3 since 1950) and could be partly responsible for the continued decrease of ozone in the lower stratosphere. Increasing iodine emissions have implications for ozone radiative forcing and possibly new particle formation near the tropopause.Fil: Koenig, Theodore K.. State University of Colorado at Boulder; Estados UnidosFil: Baidar, Sunil. State University of Colorado at Boulder; Estados UnidosFil: Campuzano Jost, Pedro. State University of Colorado at Boulder; Estados UnidosFil: Cuevas, Carlos Alberto. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Dix, Barbara. State University of Colorado at Boulder; Estados UnidosFil: Fernandez, Rafael Pedro. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Guo, Hongyu. State University of Colorado at Boulder; Estados UnidosFil: Hall, Samuel R.. National Center for Atmospheric Research; Estados UnidosFil: Kinnison, Douglas. National Center for Atmospheric Research; Estados UnidosFil: Nault, Benjamin A.. State University of Colorado at Boulder; Estados UnidosFil: Ullmann, Kirk. National Center for Atmospheric Research; Estados UnidosFil: Jimenez, Jose L.. State University of Colorado at Boulder; Estados UnidosFil: Saiz López, Alfonso. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Volkamer, Rainer. State University of Colorado at Boulder; Estados Unido

    The Contribution of Halos with Different Mass Ratios to the Overall Growth of Cluster-Sized Halos

    Get PDF
    We provide a new observational test for a key prediction of the \Lambda CDM cosmological model: the contributions of mergers with different halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this test by dynamically analyzing seven galaxy clusters, spanning the redshift range 0.13<zc<0.450.13 < z_c < 0.45 and caustic mass range 0.41.50.4-1.5 1015h0.73110^{15} h_{0.73}^{-1} M_{\odot}, with an average of 293 spectroscopically-confirmed bound galaxies to each cluster. The large radial coverage (a few virial radii), which covers the whole infall region, with a high number of spectroscopically identified galaxies enables this new study. For each cluster, we identify bound galaxies. Out of these galaxies, we identify infalling and accreted halos and estimate their masses and their dynamical states. Using the estimated masses, we derive the contribution of different mass ratios to cluster-sized halo growth. For mass ratios between ~0.2 and ~0.7, we find a ~1 σ\sigma agreement with \Lambda CDM expectations based on the Millennium simulations I and II. At low mass ratios, 0.2\lesssim 0.2, our derived contribution is underestimated since the detection efficiency decreases at low masses, 2×1014\sim 2 \times 10^{14} h0.731h_{0.73}^{-1} M_{\odot}. At large mass ratios, 0.7\gtrsim 0.7, we do not detect halos probably because our sample, which was chosen to be quite X-ray relaxed, is biased against large mass ratios. Therefore, at large mass ratios, the derived contribution is also underestimated.Comment: 25 pages, 16 figures, 6 tables, 2 machine readable tables, accepted for publication in ApJ, updated acknowledgements and data table format modifications mad
    corecore