ClassCut for Unsupervised Class Segmentation

Abstract. We propose a novel method for unsupervised class segmentation on a set of images. It alternates between segmenting object instances and learning a class model. The method is based on a segmentation energy defined over all images at the same time, which can be optimized efficiently by techniques used before in interactive segmentation. Over iterations, our method progressively learns a class model by integrating observations over all images. In addition to appearance, this model captures the location and shape of the class with respect to an automatically determined coordinate frame common across images. This frame allows us to build stronger shape and location models, similar to those used in object class detection. Our method is inspired by interactive segmentation methods [1], but it is fully automatic and learns models characteristic for the object class rather than specific to one particular object/image. We experimentally demonstrate on the Caltech4, Caltech101, and Weizmann horses datasets that our method (a) transfers class knowledge across images and this improves results compared to segmenting every image independently; (b) outperforms Grabcut [1] for the task of unsupervised segmentation; (c) offers competitive performance compared to the state-of-the-art in unsupervised segmentation and in particular it outperforms the topic model [2].

Comparación de la cinética de la infección de ovas de trucha arcoíris (Oncorhynchus mykiss) con dos cepas de Piscirickettsia salmonis detectada mediante dot-blot#

En un estudio previo, se comprobó mediante microscopía de barrido, que la cepa LF-89 se adhiere a la pared de la ovamediante prolongaciones de su membrana externa, estructuras que han sido denominadas "Complejo de AdhesiónPiscirickettsial" o CAP, lo que facilitaría la posterior penetración de la bacteria al interior de la ova. Sin embargo,existen otras cepas aisladas, como la SLGO-95, que es más virulenta y resistente a antibióticos que la LF-89 y que no seha estudiado la posibilidad de unión a ovas. Por lo anterior, en el presente trabajo se comparó la cinética de infección deovas de trucha arcoíris, entre ambas cepas, utilizando como metodología la técnica de dot-blot. El método de "dot-blot"se realizó mediante la retención de proteínas en una membrana de polivinildifluoruro (PVDF), incubación conanticuerpos oligoclonales anti-P. salmonis y posteriormente con un segundo anticuerpo anti inmunoglobulina G deratón conjugado con peroxidasa. La reacción antígeno-anticuerpo se evidenció mediante un sustratoquimioluminiscente, utilizando una película autorradiográfica. La evaluación de la reacción se realizó mediantedensitometría utilizando un "software" computacional. Para estandarizar el método se realizaron diluciones seriadas dela suspensión de P. salmonis, desde 0,02 a 56 μg de proteína total. Para aumentar la sensibilidad se centrifugaron lasmuestras a 11.000 x g por 60 min. Además, se probaron diferentes concentraciones de anticuerpo primario, 1:1000,1:5000 y 1:10.000 y muestras de ovas y bacteria fueron sometidas a desnaturalización por ebullición. Se utilizaron ovasde reproductores libres de infecciones virales, Renibacterium salmoninarum y P. salmonis. Las ovas fueron incubadas(en duplicado) con 500 μL de una suspensión de P. salmonis, ya sea con la cepa LF-89 o SLGO-95 por 1,3, 10 y 60min. Luego, cada ova fue congelada a -70°C hasta ser procesada para la técnica de "dot blot". La muestra nocentrifugada de P. salmonis fue detectada como positiva sólo hasta 0,4 μg de proteína total. Cuando fue centrifugada a11.000 g por 1 h, la bacteria fue detectada hasta la última dilución estudiada (0,02 μg). Por otra parte, no hubo grandesdiferencias en la positividad obtenida mediante las tres diluciones de anticuerpos primarios. De acuerdo, al"background" obtenido y nitidez, se consideró como una mejor dilución de trabajo 1:5000. Cuando se realizó la cinéticade infección con la cepa LF-89, los resultados indicaron la aparición de señal positiva desde 1 min de exposición de lasovas a la bacteria. La reacción positiva se mantuvo hasta los 60 min. Con respecto a la cepa SLGO-95, los resultadosfueron similares, sin embargo, la cepa SLGO-95 demostró un mayor número de píxeles, lo que indica que esta cepa seune a la ova en mayor cantidad. Los resultados apoyan los estudios anteriores que indican que P. salmonis es capaz deinfectar verticalmente las ovas y que esta podría ser una de las formas de transmisión del agente en condiciones decultivo. Además, se comprueba que el grado de infección depende del tipo de cepa actuante.  

A Materials Screening Test of Corrosion Monitoring in LiNO3 Containing Molten Salts as a Thermal Energy Storage Material for CSP Plants

Concentrated solar power (CSP) plants, in the context of thermal energy storage (TES) upgrades, need to provide a timely and effective response to the corrosion process that occurs due to the effect of high temperatures, where one of the main challenges is to control its effect, and thus the costs related to the materials used. Electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) were applied in this study as a corrosion monitoring technique. The electrochemical tests were carried out on the materials AISI304, AISI430, and HR-224 immersed in a mixture of ternary salt composed of 57 wt.% KNO3 + 13 wt.% NaNO3 + 30 wt.% LiNO3 at 550 °C during 100 h of exposure and subsequently compared with solar salt. The test was also carried out on the VM12 alloy in the ternary salt with lithium content at 100 and 1000 h of exposure at 550 °C. The corrosion tests show that the materials conform to a model of protective layer in which the same results were contrasted with the chemical corrosion mechanism of nitrate mixture. According to the results obtained in this research, electrochemical techniques could be an interesting option to control corrosion in CSP plants and reduce operational risks during operation.The authors would like to acknowledge the financial support provided by CONICYT/FONDAP 15110019 “Solar Energy Research Center” SERC-Chile and FONDEQUIP EQM170111

Learning Behavioural Context

The original publication is available at www.springerlink.co

Comparison of carbon and water fluxes and the drivers of ecosystem water use efficiency in a temperate rainforest and a peatland in southern South America

The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For 8 years (2015–2022), we measured carbon dioxide net ecosystem exchange (NEE) and evapotranspiration (ET) using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. NEE was partitioned into gross primary productivity (GPP) and ecosystem respiration (Reco), while ET was partitioned into evaporation (E) and transpiration (T) and used to estimate different expressions of ecosystem WUE. We then used the correlation between detrended time series and structural equation modelling to identify the main environmental drivers of WUE, GPP, ET, E and T. The results showed that the forest was a consistent carbon sink (−486 ± 23 g C m−2 yr−1), while the peatland was, on average, a small source (33 ± 21 g C m−2 yr−1). WUE is low in both ecosystems and likely explained by the high annual precipitation in this region (∼ 2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable, accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation and higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e. mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e. anisohydric tree species in the forest). The observed increase in potential ET in the last 2 decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant.</p

Parasitación Pulmonar por Pseudallescheria Boydii

Se comunica tres casos de parasitación pulmonar por Pseudallescheria boyii en su fase anamorfa (Sc. apiospermum) en pacientes con daño estructural previo, dos de ellos por tuberculosis.En dos pacientes se aisló el hongo en expectoración; el suero de uno de ellos presentó varias bandas de precipitación en la DDA, CIE e IEF con el antígeno metabólico preparado con su propia cepa. Los sueros de los otros pacientes no reaccionaron.En el tercer paciente se observó el hongo al examen directo del trozo de pulmón obtenido en la lobectomía.Los tres pacientes presentaron hemoptisis a repetición, la que provocó la muerte en el primer caso y lobectomía de urgencia en el tercero.Se destaca el hecho que son los primeros casos de micosis pulmonar por Ps. boydii comunicados en nuestro país

Draft genome sequence of chloride-tolerant Leptospirillum ferriphilum Sp-Cl from industrial bioleaching operations in northern Chile

Indexación: Web of Science; PubMedLeptospirillum ferriphilum Sp-Cl is a Gram negative, thermotolerant, curved, rod- shaped bacterium, isolated from an industrial bioleaching operation in northern Chile, where chalcocite is the major copper mineral and copper hydroxychloride atacamite is present in variable proportions in the ore. This strain has unique features as compared to the other members of the species, namely resistance to elevated concentrations of chloride, sulfate and metals. Basic microbiological features and genomic properties of this biotechnologically relevant strain are described in this work. The 2,475,669 bp draft genome is arranged into 74 scaffolds of 74 contigs. A total of 48 RNA genes and 2,834 protein coding genes were predicted from its annotation; 55 % of these were assigned a putative function. Release of the genome sequence of this strain will provide further understanding of the mechanisms used by acidophilic bacteria to endure high osmotic stress and high chloride levels and of the role of chloride-tolerant iron-oxidizers in industrial bioleaching operations.https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0142-

Forest hydrology in Chile: Past, present, and future

This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56 ° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a unique natural laboratory. Many local communities, endangered freshwater ecosystems, and downstream economic activities in Chile rely on water flows from forested catchments. This review aims to (i) provide a comprehensive overview of Chilean forest hydrology, to (ii) review prior research in forest hydrology in Chile, and to (iii) identify knowledge gaps and provide a vision for future research on forest hydrology in Chile. We reviewed the relation between native forests, commercial plantations, and other land uses on water yield and water quality from the plot to the catchment scale. Much of the global understanding of forests and their relationship with the water cycle is in line with the findings of the studies reviewed here. Streamflow from forested catchments increases after timber harvesting, native forests appear to use less water than plantations, and streams draining native forest yield less sediment than streams draining plantations or grassland/shrublands. We identified 20 key knowledge gaps such as forest groundwater systems, soil–plant-atmosphere interactions, native forest hydrology, and the effect of forest management and restoration on hydrology. Also, we found a paucity of research in the northern geographic areas and forest types (35-36 ° S); most forest hydrology studies in Chile (56 %) have been conducted in the southern area (Los Rios Region around 39-40 ° S). There is limited knowledge of the geology and soils in many forested areas and how surface and groundwater are affected by changes in land cover. There is an opportunity to advance our understanding using process-based investigations linking field studies and modeling. Through the establishment of a forest hydrology science “society” to coordinate efforts, regional and national-scale land use planning might be supported. Our review ends with a vision to advance a cross-scale collaborative effort to use new nation-wide catchment-scale networks Long-term Ecosystem Research (LTER) sites, to promote common and complementary techniques in these studies, and to conduct transdisciplinary research to advance sound and integrated planning of forest lands in Chile

Cycles of Police Reform in Latin America.

yesOver the last quarter century post-conflict and post-authoritarian transitions in Latin America have been accompanied by a surge in social violence, acquisitive crime, and insecurity. These phenomena have been driven by an expanding international narcotics trade, by the long-term effects of civil war and counter-insurgency (resulting in, inter alia, an increased availability of small arms and a pervasive grammar of violence), and by structural stresses on society (unemployment, hyper-inflation, widening income inequality). Local police forces proved to be generally ineffective in preventing, resolving, or detecting such crime and forms of “new violence”3 due to corruption, frequent complicity in criminal networks, poor training and low pay, and the routine use of excessive force without due sanction. Why, then, have governments been slow to prioritize police reform and why have reform efforts borne largely “limited or nonexistent” long-term results? This chapter highlights a number of lessons suggested by various efforts to reform the police in Latin America over the period 1995-2010 . It focuses on two clusters of countries in Latin America. One is Brazil and the Southern Cone countries (Chile, Argentina, and Uruguay), which made the transition to democracy from prolonged military authoritarian rule in the mid- to late 1980s. The other is Central America and the Andean region (principally El Salvador, Guatemala, Honduras, Peru, and Colombia), which emerged/have been emerging from armed conflict since the mid- 1990s. The chapter examines first the long history of international involvement in police and security sector reform in order to identify long-run tropes and path dependencies. It then focuses on a number of recurring themes: cycles of de- and re-militarization of the policing function; the “security gap” and “democratization dilemmas” involved in structural reforms; the opportunities offered by decentralization for more community-oriented police; and police capacity to resist reform and undermine accountability mechanisms