Evolution of the Great Tehuelche Paleolake in the Torres del Paine National Park of Chilean Patagonia during the Last Glacial Maximum and Holocene

Indexación: Web of Science; ScieloRESUMEN. Una serie de morrenas glaciares se distribuyen desde el margen oriental de la cuenca de drenaje Torres del Paine a cerca del actual margen de los Campos de Hielo Patagónico, junto con una serie de terrazas lacustres regional continuos relacionados con las fluctuaciones glaciales. La geomorfología, apoyada por la evidencia de sedimentos del lago, indica la existencia de un único paleolago proglacial en esta zona, aquí denominado el Gran Tehuelche paleolago. Este concepto ayuda a aclarar la cronología de eventos glaciales y conduce a una mejor comprensión de la evolución del sistema hidrológico de la zona de Torres del Paine. Avances glaciales referidos anteriormente como ocurrieron A, B y C durante el Último Máximo Glacial y alimentados con la Gran Tehuelche paleolago con agua de deshielo, que le permite alcanzar su máxima extensión. El descubrimiento de trombolitos en Laguna Amarga sugiere que el drenaje de la paleolago hacia el fiordo de Última Esperanza tuvo lugar en 7113 Cal. años AP, después de la fusión de una barrera de hielo que existía durante el avance glacial antes. Esto dio lugar al desarrollo de un sistema hidrológico fluvio-lacustre complejo que persiste hasta nuestros días. Palabras clave: Patagonia, último máximo glacial, Younger Dryas, trombolitos. RESUMEN. Un grupo de morrenas glaciales estan Distribuidas desde el margen Este de la cuenca de drenaje de Torres del Paine Hacia el margen real de los Campos de Hielo Patagónicos. Las morrenas se observan en conjunto con las Naciones Unidas Grupo de terrazas Lacustres Regionales, las Cuales estan vinculadas y una las fluctuaciones glaciales. La geomorfología y Evidencias de sedimentos Lacustres indicano la existence De unico ONU lago proglacial, referido En Este Estudio de Como Gran Paleolago Tehuelche. Este Concepto ayuda a clarificar la cronología de los eventos glaciales y permite Una mejor Comprensión de la Evolución del Sistema hidrológico del sector de Torres del Paine. Los eventos glaciales, previamente Referidos Como Avance A, B y C, ocurrieron Durante el Último Máximo Glacial y alimentaron con Aguas de fusión al Gran Paleolago Tehuelche, permitiéndole Alcanzar su alcalde extensión. El Descubrimiento de trombolitos en Laguna Amarga sugiere Que El desagüe del paleolago Ocurrió Hace 7.113 Cal. Por años AP el Seno de Última Esperanza, producto de la fusión De Una barrera glaciar existente Durante los Avances glaciales Anteriores. LUEGO del drenaje sí Desarrollo en Un complejo Sistema hidrológico Que Persiste Hasta el presente. Palabras clave: Patagonia, Último Máximo Glacial, Dryas Temprano, Trombolitos.http://ref.scielo.org/wgc2q

The Human Nose as a Chemical Sensor in the Perception of Coffee Aroma: Individual Variability

The flavor of foods and beverages is generally composed of a mixture of volatile compounds, however not all the molecules that form an aroma are sensorially relevant. The odor-active compounds present in a mixture are different for each subject, both in quantitative and qualitative terms. This means that the ability of the human nose to act as a chemical sensor varies among individuals. In this study, we used the headspace of roasted coffee beans as a complex olfactory stimulus and, by means of the coupled Gas Chromatography-Olfactometry (GC-O) technique, the single components of coffee flavor were separated. Each subject, previously classified for his/her olfactory status (normosmic, hyposmic or anosmic) by means of the Sniffin' Sticks battery (composed of Threshold, Discrimination and Identification subtests), had to identify and evaluate each smelled molecule. The results show that the individual ability to detect individual compounds during the GC-O experiments and the odor intensity reported during the sniffing of pen #10 (the pen of the identification test) containing coffee aroma were related to TDI olfactory status (based on the score obtained from the sum composed of Threshold, Discrimination and Identification scores). We also found that the number of total molecules and of molecules smelling of coffee is linearly related to the TDI olfactory score. Finally, the odor intensity reported when sniffing pen #10 containing coffee aroma is positively correlated with the number of molecules detected and the average intensity reported. In conclusion, our findings show that the human perception of both individual compounds and complex odors is strongly conditioned by the olfactory function of subjects

Virtual Reality to Simulate Visual Tasks for Robotic Systems

Virtual reality (VR) can be used as a tool to analyze the interactions between the visual system of a robotic agent and the environment, with the aim of designing the algorithms to solve the visual tasks necessary to properly behave into the 3D world. The novelty of our approach lies in the use of the VR as a tool to simulate the behavior of vision systems. The visual system of a robot (e.g., an autonomous vehicle, an active vision system, or a driving assistance system) and its interplay with the environment can be modeled through the geometrical relationships between the virtual stereo cameras and the virtual 3D world. Differently from conventional applications, where VR is used for the perceptual rendering of the visual information to a human observer, in the proposed approach, a virtual world is rendered to simulate the actual projections on the cameras of a robotic system. In this way, machine vision algorithms can be quantitatively validated by using the ground truth data provided by the knowledge of both the structure of the environment and the vision system

The annual rate of independent events - A key interpretation for traditional extreme value distributions of wind velocity

The extreme value theory has been object of engineering studies for more than a century. The analysis of extreme winds plays a key role for complex civil structures and a driving role in different stages of wind turbines lifetime. Most of extremes probability models depend on the annual rate of independent events (ARIE) which has been traditionally considered a constant value. The authors have embraced a recent belief considering the ARIE as a function of the wind velocity. Even though a certain agreement has been achieved across the researches, some issues are still pending. In this regard, the paper shows that the annual, seasonal and daily fluctuations embedded in time series of the mean wind speeds, constrain its probability distribution and time correlation to be physically consistent. Besides, a new physical interpretation of the ARIE is presented, expressing how the independence across wind observations increases with the wind speed, up to the point that all yearly observations are independent if larger than a suitable speed value. Such a tendency is not revealed if the annual, seasonal and daily fluctuations are excluded by the analysis, leading to a deceitful shape of the ARIE. Finally, the paper shows how the velocity-dependent ARIE model is consistent with the conventional asymptotic extreme value theory, if a sufficiently large left-censorship applies to the dataset. The study of the ARIE presented in this paper is based on long-term Monte Carlo simulation of the mean wind speed

Design strategies for direct multi-scale and multi-orientation feature extraction in the log-polar domain

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Avaliação de genótipos de Avena sativa L. quanto a produção de forragem na região da Campanha/RS.

CONGREGA 2012

Effectiveness of the spot-on combination of moxidectin and imidacloprid (Advocate®) in the treatment of ocular thelaziosis by Thelazia callipaeda in naturally infected cats

Background: The present study evaluated the therapeutic effectiveness of moxidectin 1.0% (w/v) and imidacloprid 10% (w/v) (Advocate® spot-on solution for cats, Bayer Animal Health) against natural infections with the eyeworm Thelazia callipaeda in cats. This study was conducted as a GCP, negative-controlled, blinded and randomised field study in privately owned cats living in an area in southern Italy where T. callipaeda is enzootic. Methods: The study was carried out in 30 cats (19 females and 11 males, aged from 8 months to 5 years, weighing 1.2-5.2 kg) of different breeds, naturally infected by T. callipaeda. At study inclusion (Day 0), animals were physically examined and the infection level was assessed by examination of both eyes for clinical score and live adult T. callipaeda count. Each cat was weighed and randomly assigned to one of the treatment groups (G1: Advocate, G2: untreated control). Clinical assessments and T. callipaeda adult counts were performed on Day 14. At the study completion visit on Day 28, clinical assessments and counts of T. callipaeda adults and larvae were performed. All cats were daily observed by their owners and general health conditions were recorded during the entire period of the study. Results: The primary effectiveness variable was the percentage of animals in G1 group (Advocate) showing a complete elimination (parasitological cure) of adult eye worms at Day 14 and Day 28. The effectiveness of the treatment in the G1 group was 93.3 and 100% at Day 14 and Day 28, respectively, when compared to group G2. Total worm count reduction from both eyes for Advocate was 96.3% on Day 14 and 100% on Day 28. Clinical data were confirmed by the examination of conjunctival pouch flushing. An overall reduction in the number of cats with lacrimation and conjunctivitis was observed following treatment despite the fact that in a few cats treated with Advocate clinical signs persisted due to the chronic nature of the disease. Conclusions: Based on the results of the present trial, a single dose of Advocate was found to be safe and highly effective in the treatment of natural T. callipaeda infection in cats

Near-optimal combination of disparity across a log-polar scaled visual field

The human visual system is foveated: we can see fine spatial details in central vision, whereas resolution is poor in our peripheral visual field, and this loss of resolution follows an approximately logarithmic decrease. Additionally, our brain organizes visual input in polar coordinates. Therefore, the image projection occurring between retina and primary visual cortex can be mathematically described by the log-polar transform. Here, we test and model how this space-variant visual processing affects how we process binocular disparity, a key component of human depth perception. We observe that the fovea preferentially processes disparities at fine spatial scales, whereas the visual periphery is tuned for coarse spatial scales, in line with the naturally occurring distributions of depths and disparities in the real-world. We further show that the visual system integrates disparity information across the visual field, in a near-optimal fashion. We develop a foveated, log-polar model that mimics the processing of depth information in primary visual cortex and that can process disparity directly in the cortical domain representation. This model takes real images as input and recreates the observed topography of human disparity sensitivity. Our findings support the notion that our foveated, binocular visual system has been moulded by the statistics of our visual environment

Ulva as potential stimulant and attractant for a valuable sea urchin species: a chemosensory study

The green seaweed Ulva is close to becoming popular due to its suitability as potential feedstock production and for food items. However, there is a general lack of studies on the aversion or acceptability of this alga by marine organisms, particularly on its role as a chemoattractant and/or phagostimulant activity. Here we tested the effect of Ulva compressa and other biochemicals as potential chemostimulating compounds for a valuable sea urchin species, Paracentrotus lividus, selected as model species for our tests. Sea urchins’ chemical sensitivity was estimated by analysing movements of spines, pedicellariae, tube feet, and individual locomotion using an innovative bioassay. Our results showed that all forms of Ulva (fresh, defrosted, and fragmented) resulted in an effective stimulus, evoking in sea urchins strong responses with robust activation of spines and tube feet, where the defrosted one was the most stimulating. Among the amino acids tested, glycine, alanine, and glutamine produced a significant response, highlighting for the latter a concentration–response relationship. Sea urchins responded to glucose, not to fructose and sucrose. Spirulina resulted as the most effective stimulus, acting in a dose-dependent manner. Major results indicate the role of Ulva as a chemostimulant and strongly attractant for such herbivore species. From an applied point of view, the presence of potential Ulva’s feed-related compounds, acting as chemoattractants (to reduce food searching time) and/or feeding stimulants (to stimulate ingestion), would improve the several applications of Ulva in the formulation of the feeds for sustainable aquacultur

Why phosphoproteomics is still a challenge

Despite continuous improvements phosphoproteomics still faces challenges that are often neglected, e.g. partially poor recovery of phosphopeptide enrichment, assessment of phosphorylation stoichiometry, label-free quantification, poor behavior during chromatography, and general limitations of peptide-centric proteomics. Here we critically discuss current limitations that need consideration in both qualitative and quantitative studies