Exemplar based metric learning for robust visual localization

This paper presents an exemplar based metric learning framework dedicated to robust visual localization in com-plex scenes, e.g. street images. The proposed framework learns off-line a specific (local) metric for each image of the database, so that the distance between a database image and a query image representing the same scene is smaller than the distance between the current image and other images of the database. To achieve this goal, we generate geometric and photometric transformations as proxies for query im-ages. From the generated constraints, the learning problem is cast as a convex optimization problem over the cone of positive semi-definite matrices, which is efficiently solved using a projected gradient descent scheme. Successful ex-periments, conducted using a freely available geo-referenced image database, reveal that the proposed method significantly improves results over the metric in the input space, while being as efficient at test time. In addition, we show that the model learns discriminating features for the localization task, and is able to gain invariance to meaningful transformations. Index Terms — content-based image retrieval, supervised metric learning, visual localization, place recognition 1. CONTEXT The problem tackled in this paper is visual localization at a street level [1] [2] [3]. Visual localization methods differ from each other by the type of features extracted online (2D only [2] and/or 3D [4]), the matching method (dedicated or not to large scale [5] [6]), and the a priori information used (geo-referenced database image [2], 3D model [3], 2D road-map [7], mobile cell phone information [6],...). Our typical scenario is the precise localization of a vehicle whose ap-proximate localization is known. Our problem is cast to an image retrieval (IR) problem using only 2D features extracted from acquired images and 2D geo-referenced database im-age (Fig. 1). Exploiting only image content is challenging because, even if query and database images depict the same scene, camera-view points, illumination and colorimetry are different, the scene itself may have changed over time an

Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

Abstract. In this paper we combine SO2 and ash plume dispersion modelling with satellite and surface remote sensing observations to study the regional influence of a relatively weak volcanic eruption from Mount Etna on the optical and micro-physical properties of Mediterranean aerosols. We analyse the Mount Etna eruption episode of 25–27 October 2013. The evolution of the plume along the trajectory is investigated by means of the FLEXible PARTicle Lagrangian dispersion (FLEXPART) model. The satellite data set includes true colour images, retrieved values of volcanic SO2 and ash, estimates of SO2 and ash emission rates derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations and estimates of cloud top pressure from SEVIRI (Spinning Enhanced Visible and InfraRed Imager). Surface remote sensing measurements of aerosol and SO2 made at the ENEA Station for Climate Observations (35.52° N, 12.63° E; 50 m a.s.l.) on the island of Lampedusa are used in the analysis. The combination of these different data sets suggests that SO2 and ash, despite the initial injection at about 7.0 km altitude, reached altitudes around 10–12 km and influenced the column average aerosol particle size distribution at a distance of more than 350 km downwind. This study indicates that even a relatively weak volcanic eruption may produce an observable effect on the aerosol properties at the regional scale. The impact of secondary sulfate particles on the aerosol size distribution at Lampedusa is discussed and estimates of the clear-sky direct aerosol radiative forcing are derived. Daily shortwave radiative forcing efficiencies, i.e. radiative forcing per unit AOD (aerosol optical depth), are calculated with the LibRadtran model. They are estimated between −39 and −48 W m−2 AOD−1 at the top of the atmosphere and between −66 and −49 W m−2 AOD−1 at the surface, with the variability in the estimates mainly depending on the aerosol single scattering albedo. These results suggest that sulfate particles played a large role in the transported plume composition and radiative forcing, while the contribution by ash particles was small in the volcanic plume arriving at Lampedusa during this event

Estrategia para el control de brucelosis bovina en tambos familiares del periurbano oeste del área metropolitana de Buenos Aires

En las cercanías de las grandes ciudades, parte de los sistemas pecuarios se desarrollan en un marco de crianza Agroecológicos (AE). La producción de alimentos por parte de los agricultores familiares del periurbano es significativa y presenta puntos críticos que ponen en riesgo la inocuidad; y a su vez existen herramientas técnicas, saberes locales e instituciones estatales que pueden organizarse para resolver dicha problemática. A partir del plan piloto para el control y erradicación de brucelosis y tuberculosis en el Municipio de Marcos Paz, se pretendió establecer una metodología para la determinación de Brucelosis “no invasiva” que permitiera ofrecer un diagnóstico poblacional rápido, brindar alternativas para el control y la erradicación de la enfermedad y poner en valor a la producción lechera familiar. Se llevó a cabo entre julio y diciembre de 2014; por productores, investigadores y extensionistas del INTA. El 92 % de los tambos analizados fue negativo a Brucelosis.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Calidad de leche en tambos familiares del periurbano oeste del área metropolitana de Buenos Aires

Cerca de las grandes ciudades, parte de los sistemas pecuarios se desarrollan en un marco de crianza Agroecológicos (AE), fortaleciendo al sector de la pequeña agricultura, generando alimentos de elevado valor, con trazabilidad. Para conocer las características del producto y generar valor agregado, es necesario determinar calidad composicional, sanitaria y ausencia de residuos de antibióticos, que influyen en la industrialización de la leche. El objetivo fue caracterizar la calidad de leche analizando leche de tanque de 26 productores de Marcos Paz, La Matanza y Gral. Rodríguez. Se llevó a cabo entre junio y diciembre de 2014; por productores, investigadores y extensionistas del INTA. Los resultados demostraron una baja incidencia de mastitis clínicas, ausencia de residuos de antibióticos aunque una elevada flora saprófita. Este tipo de experiencias resultan útiles para detectar dificultades en el proceso de producción de leche, y poner en valor los productos obtenidos en explotaciones lecheras con manejo AE.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Estrategia para el control de brucelosis bovina en tambos familiares del periurbano oeste del área metropolitana de Buenos Aires

En las cercanías de las grandes ciudades, parte de los sistemas pecuarios se desarrollan en un marco de crianza Agroecológicos (AE). La producción de alimentos por parte de los agricultores familiares del periurbano es significativa y presenta puntos críticos que ponen en riesgo la inocuidad; y a su vez existen herramientas técnicas, saberes locales e instituciones estatales que pueden organizarse para resolver dicha problemática. A partir del plan piloto para el control y erradicación de brucelosis y tuberculosis en el Municipio de Marcos Paz, se pretendió establecer una metodología para la determinación de Brucelosis “no invasiva” que permitiera ofrecer un diagnóstico poblacional rápido, brindar alternativas para el control y la erradicación de la enfermedad y poner en valor a la producción lechera familiar. Se llevó a cabo entre julio y diciembre de 2014; por productores, investigadores y extensionistas del INTA. El 92 % de los tambos analizados fue negativo a Brucelosis.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Estrategia para el control de brucelosis bovina en tambos familiares del periurbano oeste del área metropolitana de Buenos Aires

En las cercanías de las grandes ciudades, parte de los sistemas pecuarios se desarrollan en un marco de crianza Agroecológicos (AE). La producción de alimentos por parte de los agricultores familiares del periurbano es significativa y presenta puntos críticos que ponen en riesgo la inocuidad; y a su vez existen herramientas técnicas, saberes locales e instituciones estatales que pueden organizarse para resolver dicha problemática. A partir del plan piloto para el control y erradicación de brucelosis y tuberculosis en el Municipio de Marcos Paz, se pretendió establecer una metodología para la determinación de Brucelosis “no invasiva” que permitiera ofrecer un diagnóstico poblacional rápido, brindar alternativas para el control y la erradicación de la enfermedad y poner en valor a la producción lechera familiar. Se llevó a cabo entre julio y diciembre de 2014; por productores, investigadores y extensionistas del INTA. El 92 % de los tambos analizados fue negativo a Brucelosis.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Calidad de leche en tambos familiares del periurbano oeste del área metropolitana de Buenos Aires

Cerca de las grandes ciudades, parte de los sistemas pecuarios se desarrollan en un marco de crianza Agroecológicos (AE), fortaleciendo al sector de la pequeña agricultura, generando alimentos de elevado valor, con trazabilidad. Para conocer las características del producto y generar valor agregado, es necesario determinar calidad composicional, sanitaria y ausencia de residuos de antibióticos, que influyen en la industrialización de la leche. El objetivo fue caracterizar la calidad de leche analizando leche de tanque de 26 productores de Marcos Paz, La Matanza y Gral. Rodríguez. Se llevó a cabo entre junio y diciembre de 2014; por productores, investigadores y extensionistas del INTA. Los resultados demostraron una baja incidencia de mastitis clínicas, ausencia de residuos de antibióticos aunque una elevada flora saprófita. Este tipo de experiencias resultan útiles para detectar dificultades en el proceso de producción de leche, y poner en valor los productos obtenidos en explotaciones lecheras con manejo AE.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Clinical Characteristics Associated with Bacterial Bloodstream Coinfection in COVID-19

INTRODUCTION: Inappropriate antibiotic use in COVID-19 is often due to treatment of presumed bacterial coinfection. Predictive factors to distinguish COVID-19 from COVID-19 with bacterial coinfection or bloodstream infection are limited. METHODS: We conducted a retrospective cohort study of 595 COVID-19 patients admitted between March 8, 2020, and April 4, 2020, to describe factors associated with a bacterial bloodstream coinfection (BSI). The primary outcome was any characteristic associated with BSI in COVID-19, with secondary outcomes including 30-day mortality and days of antibiotic therapy (DOT) by antibiotic consumption (DOT/1000 patient-days). Variables of interest were compared between true BSI (n = 25) and all other COVID-19 cases (n = 570). A secondary comparison was performed between positive blood cultures with true BSI (n = 25) and contaminants (n = 33) on antibiotic use. RESULTS: Fever (\u3e 38 °C) (as a COVID-19 symptom) was not different between true BSI (n = 25) and all other COVID-19 patients (n = 570) (p = 0.93), although it was different as a reason for emergency department (ED) admission (p = 0.01). Neurological symptoms (ED reason or COVID-19 symptom) were significantly higher in the true BSI group (p \u3c 0.01, p \u3c 0.01) and were independently associated with true BSI (ED reason: OR = 3.27, p \u3c 0.01; COVID-19 symptom: OR = 2.69, p = 0.03) on multivariate logistic regression. High (15-19.9 × 10(9)/L) white blood cell (WBC) count at admission was also higher in the true BSI group (p \u3c 0.01) and was independently associated with true BSI (OR = 2.56, p = 0.06) though was not statistically significant. Thirty-day mortality was higher among true BSI (p \u3c 0.01). Antibiotic consumption (DOT/1000 patient-days) between true BSI and contaminants was not different (p = 0.34). True bloodstream coinfection was 4.2% (25/595) over the 28-day period. CONCLUSION: True BSI in COVID-19 was associated with neurological symptoms and nonsignificant higher WBC, and led to overall higher 30-day mortality and worse patient outcomes

In vitro inhibition of porcine cytochrome P450 by 17β -estradiol and 17α-estradiol

Sexually mature pigs are known to possess high concentrations of testicular steroids, which have been shown to change the activities of cytochrome P450 in vitro. The aim of the present study was to evaluate the regulation of CYP1A and CYP2E1 activity by the steroids dihydrotestosterone (DHT), 3β-androstenol, 17β-estradiol and 17α-estradiol. Catalytic activities of 7-ethoxyresorufin O-deethylase (EROD) and 7-methoxyresorufin O-demethylase (MROD) were used as markers of CYP1A activities, while p-nitrophenol hydroxylase (PNPH) was used as a marker of CYP2E1 activities. Of the steroids tested, only 17β-estradiol and 17α-estradiol inhibited EROD and MROD activities. This inhibition was observed when a steroid concentration of 100 µM was used, while lower concentrations showed no inhibitory effect. PNPH activities were inhibited only by 100 µM of 17β-estradiol. The significance of these results in vivo is unknown because inhibition was only found when concentrations of estrogens higher than physiological levels were used. Nevertheless, the results provided further evidence on the important role of estrogens in regulation of porcine cytochrome P450 activities