40 research outputs found

    3D reconstruction of medical images from slices automatically landmarked with growing neural models

    Get PDF
    In this study, we utilise a novel approach to segment out the ventricular system in a series of high resolution T1-weighted MR images. We present a brain ventricles fast reconstruction method. The method is based on the processing of brain sections and establishing a fixed number of landmarks onto those sections to reconstruct the ventricles 3D surface. Automated landmark extraction is accomplished through the use of the self-organising network, the growing neural gas (GNG), which is able to topographically map the low dimensionality of the network to the high dimensionality of the contour manifold without requiring a priori knowledge of the input space structure. Moreover, our GNG landmark method is tolerant to noise and eliminates outliers. Our method accelerates the classical surface reconstruction and filtering processes. The proposed method offers higher accuracy compared to methods with similar efficiency as Voxel Grid

    Real time motion estimation using a neural architecture implemented on GPUs

    Get PDF
    This work describes a neural network based architecture that represents and estimates object motion in videos. This architecture addresses multiple computer vision tasks such as image segmentation, object representation or characterization, motion analysis and tracking. The use of a neural network architecture allows for the simultaneous estimation of global and local motion and the representation of deformable objects. This architecture also avoids the problem of finding corresponding features while tracking moving objects. Due to the parallel nature of neural networks, the architecture has been implemented on GPUs that allows the system to meet a set of requirements such as: time constraints management, robustness, high processing speed and re-configurability. Experiments are presented that demonstrate the validity of our architecture to solve problems of mobile agents tracking and motion analysis

    The holy grail:Environmental management, competitive advantage and business performance in the Spanish hotel industry

    Get PDF
    © Emerald Group Publishing Limited G959-6119. Purpose - This paper aims to analyse the influence of environmental proactivity on cost and differentiation competitive advantages, and to explore the double relationship between environmental proactivity and business performance. Design/methodology/approach - The population consists of all three- to five-star hotels in Spain. A sample of 350 hotels was classified according to environmental proactivity and performance levels, employing a two-step cluster analysis. Significant differences between groups were examined. Findings - The results show two types of environmental behaviour (reactive and proactive), with proactive hotels developing significantly better on both cost and differentiation competitive advantage and achieving significantly higher performance levels. Hotels which achieve above average business performance levels are significantly more environmentally proactive. Research limitations/implications - The present paper demonstrates that environmental management is related to competitive advantages and business performance. Environmental management systems are more developed in higher category, chain-affiliated and larger hotels. This could be due to having more resources to develop their environmental capability. The environmental proactivity scale employed in this study is presented as a reference measure for hotel managers to benchmark their current practices and implement environmental improvements. Originality/value - First, measuring environmental proactivity using four managerial systems (operative, information, strategic and technical) is innovative and provides a more detailed approach to measuring environmental proactivity. Second, demonstrating a double association between environmental proactivity and performance provides fresh insights into the relationship between these variables

    Evaluating anemometer drift: A statistical approach to correct biases in wind speed measurement

    Get PDF
    Recent studies on observed wind variability have revealed a decline (termed “stilling”) of near-surface wind speed during the last 30–50 years over many mid-latitude terrestrial regions, particularly in the Northern Hemisphere. The well-known impact of cup anemometer drift (i.e., wear on the bearings) on the observed weakening of wind speed has been mentioned as a potential contributor to the declining trend. However, to date, no research has quantified its contribution to stilling based on measurements, which is most likely due to lack of quantification of the ageing effect. In this study, a 3-year field experiment (2014–2016) with 10-minute paired wind speed measurements from one new and one malfunctioned (i.e., old bearings) SEAC SV5 cup anemometer which has been used by the Spanish Meteorological Agency in automatic weather stations since mid-1980s, was developed for assessing for the first time the role of anemometer drift on wind speed measurement. The results showed a statistical significant impact of anemometer drift on wind speed measurements, with the old anemometer measuring lower wind speeds than the new one. Biases show a marked temporal pattern and clear dependency on wind speed, with both weak and strong winds causing significant biases. This pioneering quantification of biases has allowed us to define two regression models that correct up to 37% of the artificial bias in wind speed due to measurement with an old anemometer

    Efficacy of ATR inhibitors as single agents in Ewing sarcoma

    Get PDF
    Ewing sarcomas (ES) are pediatric bone tumors that arise from a driver translocation, most frequently EWS/FLI1. Current ES treatment involves DNA damaging agents, yet the basis for the sensitivity to these therapies remains unknown. Oncogene-induced replication stress (RS) is a known source of endogenous DNA damage in cancer, which is suppressed by ATR and CHK1 kinases. We here show that ES suffer from high endogenous levels of RS, rendering them particularly dependent on the ATR pathway. Accordingly, two independent ATR inhibitors show in vitro toxicity in ES cell lines as well as in vivo efficacy in ES xenografts as single agents. Expression of EWS/FLI1 or EWS/ERG oncogenic translocations sensitizes non-ES cells to ATR inhibitors. Our data shed light onto the sensitivity of ES to genotoxic agents, and identify ATR inhibitors as a potential therapy for Ewing Sarcomas.We would want to thank Enrique de Alava for providing ES lines. Work in O.F. laboratory was supported by Fundación Botín, by Banco Santander through its Santander Universities Global Division and by grants from MINECO (SAF2014-57791-REDC and SAF2014-59498-R), Fundació La Marato de TV3, Howard Hughes Medical Institute and the European Research Council (ERC-617840). The A.N. laboratory was supported by the Intramural Research Program of the NIH, the National Cancer Institute, the Center for Cancer Research, an Ellison Medical Foundation Senior Scholar in Aging, and the Alex Lemonade Stand Foundation Award. J.A. laboratory is supported by Asociación Pablo Ugarte, ASION-La Hucha de Tomás, Fundación La Sonrisa de Alex and Instituto de Salud Carlos III (PI12/00816 and Spanish Cancer Network RTICC RD12/0036/0027). A.L. laboratory was supported by the Danish National Research Foundation (DNRF115), Danish Council for Independent Research (Sapere Aude, DFF-Starting Grant 2014) and Danish Cancer Society (KBVU-2014).S

    Seafood Consumption, Omega-3 Fatty Acids Intake, and Life-Time Prevalence of Depression in the PREDIMED-Plus Trial

    Get PDF
    Background: The aim of this analysis was to ascertain the type of relationship between fish and seafood consumption, omega-3 polyunsaturated fatty acids (ω-3 PUFA) intake, and depression prevalence. Methods: Cross-sectional analyses of the PREDIMED-Plus trial. Fish and seafood consumption and ω-3 PUFA intake were assessed through a validated food-frequency questionnaire. Self-reported life-time medical diagnosis of depression or use of antidepressants was considered as outcome. Depressive symptoms were collected by the Beck Depression Inventory-II. Logistic regression models were used to estimate the association between seafood products and ω-3 PUFA consumption and depression. Multiple linear regression models were fitted to assess the association between fish and long-chain (LC) ω-3 PUFA intake and depressive symptoms. Results: Out of 6587 participants, there were 1367 cases of depression. Total seafood consumption was not associated with depression. The odds ratios (ORs) (95% confidence intervals (CIs)) for the 2nd, 3rd, and 4th quintiles of consumption of fatty fish were 0.77 (0.63–0.94), 0.71 (0.58–0.87), and 0.78 (0.64–0.96), respectively, and p for trend = 0.759. Moderate intake of total LC ω-3 PUFA (approximately 0.5–1 g/day) was significantly associated with a lower prevalence of depression. Conclusion: In our study, moderate fish and LC ω-3 PUFA intake, but not high intake, was associated with lower odds of depression suggesting a U-shaped relationship

    From Tthe “Quincallería” to the late antiquity burial at 6 Selgas Street, Lorca (Murcia)

    No full text
    ©. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published, version of a Published Work that appeared in final form in [Alberca]La excavación del solar de la calle Selgas núm. 6 ha permitido aportar más indicios al devenir histórico del lugar de la ciudad de Lorca. Por un lado, ha corroborado la información que se tenía en los archivos de este lugar, además de dejar a la vista que los vertederos de los alfares almohades del barrio de alfareros llegaban hasta la misma ladera de la medina, al exterior de la muralla. Además, se ha constatado la presencia de enterramientos posiblemente de un momento tardoantiguo que con un estudio antropológico completo podrían acercarnos más a la vida cotidiana de los antiguos pobladores de Eliocroca.The excavation of the lot at 6 Selgas St. has allowed providing more indications of the historical evolution of Lorca city. On the one hand, it has corroborated the information that was located in the Archives of this specific place, in addition to showing that the dumps of the Almohad potteries of the Potters Quarter reached the very slope of the Medina, outside the city wall. Furthermore, the presence of burials, possibly from the Late Roman period, has been confirmed, that with a complete anthropological study could bring us closer to the daily life of some of the ancient inhabitants of Eliocroca

    The Holy Grail: Environmental management, competitive advantage and business performance in the Spanish hotel industry

    No full text
    Purpose - This paper aims to analyse the influence of environmental proactivity on cost and differentiation competitive advantages, and to explore the double relationship between environmental proactivity and business performance. Design/methodology/approach - The population consists of all three- to five-star hotels in Spain. A sample of 350 hotels was classified according to environmental proactivity and performance levels, employing a two-step cluster analysis. Significant differences between groups were examined. Findings - The results show two types of environmental behaviour (reactive and proactive), with proactive hotels developing significantly better on both cost and differentiation competitive advantage and achieving significantly higher performance levels. Hotels which achieve above average business performance levels are significantly more environmentally proactive. Research limitations/implications - The present paper demonstrates that environmental management is related to competitive advantages and business performance. Environmental management systems are more developed in higher category, chain-affiliated and larger hotels. This could be due to having more resources to develop their environmental capability. The environmental proactivity scale employed in this study is presented as a reference measure for hotel managers to benchmark their current practices and implement environmental improvements. Originality/value - First, measuring environmental proactivity using four managerial systems (operative, information, strategic and technical) is innovative and provides a more detailed approach to measuring environmental proactivity. Second, demonstrating a double association between environmental proactivity and performance provides fresh insights into the relationship between these variables

    Hydrological and depositional processes associated with recent glacier recession in Yanamarey catchment, Cordillera Blanca (Peru)

    No full text
    In this study, we investigate changes in the glaciated surface and the formation of lakes in the headwater of the Querococha watershed in Cordillera Blanca (Peru) using 24 Landsat images from 1975 to 2014. Information of glacier retreat was integrated with available climate data, the first survey of recent depositional dynamics in proglacial Yanamarey Lake (4600m a.s.l.), and a relatively short hydrological record (2002-2014) at the outlet of Yanamarey Lake. A statistically significant temperature warming (0.21°C decade-1 for mean annual temperature) has been detected in the region, and it caused a reduction of the glacierized area since 1975 from 3.5 to 1.4km-2. New small lakes formed in the deglaciated areas, increasing the flooded area from1.8ha in 1976 to 2.8ha in 2014. A positive correlation between annual rates of glacier recession and runoff was found. Sediment cores revealed a high sedimentation rate (>1cmyr-1) and two contrasted facies, suggesting a shift toward a reduction of meltwater inputs and higher hydrological variability likely due to an increasing role of precipitation on runoff during the last decades. Despite the age control uncertainties, the main transition likely occurred around 1998-2000, correlating with the end of the phase with maximum warming rates and glacier retreat during the 1980s and 1990s, and the slowing down of expansion of surface lake-covered surface. With this hydrological - paleolimnological approach we have documented the association between recent climate variability and glacier recession and the rapid transfer of hydroclimate signal to depositional and geochemical processes in high elevation Andean environments. This, study also alerts about water quality risks as proglacial lakes act as secondary reservoirs that trap trace and minor elements in high altitude basins
    corecore