581 research outputs found

    Unsupervised domain adaptation for mobile semantic segmentation based on cycle consistency and feature alignment

    Get PDF
    The supervised training of deep networks for semantic segmentation requires a huge amount of labeled real world data. To solve this issue, a commonly exploited workaround is to use synthetic data for training, but deep networks show a critical performance drop when analyzing data with slightly different statistical properties with respect to the training set. In this work, we propose a novel Unsupervised Domain Adaptation (UDA) strategy to address the domain shift issue between real world and synthetic representations. An adversarial model, based on the cycle consistency framework, performs the mapping between the synthetic and real domain. The data is then fed to a MobileNet-v2 architecture that performs the semantic segmentation task. An additional couple of discriminators, working at the feature level of the MobileNet-v2, allows to better align the features of the two domain distributions and to further improve the performance. Finally, the consistency of the semantic maps is exploited. After an initial supervised training on synthetic data, the whole UDA architecture is trained end-to-end considering all its components at once. Experimental results show how the proposed strategy is able to obtain impressive performance in adapting a segmentation network trained on synthetic data to real world scenarios. The usage of the lightweight MobileNet-v2 architecture allows its deployment on devices with limited computational resources as the ones employed in autonomous vehicles

    Implications of flexible spacer rotational processes on the liquid crystal behavior of 4,5-dihydroisoxazole benzoate dimers

    Get PDF
    The synthesis of some novel non-symmetric liquid crystal dimers, {3-[4-(octyloxyphenyl)]-4,5-dihydroisoxazol-5-yl}alkyl 4-(decyloxy)benzoates (5a–d) and 4-{3-[4-(octyloxyphenyl)]-4,5-dihydroisoxazol-5-yl}alkyl 4-{[6-(octyloxy)naphthalen-2-yl]ethynyl}benzoate (9a–d), are reported. The liquid-crystalline properties, theoretical calculations based on the conformational aspects of the flexible alkyl spacer and X-ray experiments are discussed. The syntheses of the key intermediates, 2-{3-[4-(octyloxy)phenyl]-4,5-dihydroisoxazol-5-yl}alkanol (3a–d), presenting the flexible alkyl spacer were achieved through [3+2] cycloaddition reactions between nitrile oxides, which were generated in situ by oxidation of the respective aromatic oximes, and dipolarophile alkenols (CH2[double bond, length as m-dash]CH(CH2)nOH, n = 1, 2, 3, and 4). The benzoates 5a–d were synthesized through esterification of 3a–d and p-n-decyloxybenzoic acid (4). The esters 9a–d were synthesized through derivatization of isoxazolines 3a–d into 4-{3-[4-(octyloxyphenyl)]-4,5-dihydroisoxazol-5-yl}alkyl 4-bromobenzoate (7a–d) followed by a Sonogashira reaction with 2-ethynyl-6-octyloxynaphthalene (8). 5a and 5b showed a monotropic smectic C phase. 9a/c displayed a enantiotropic nematic (N) mesophase, whereas 9b/d showed a monotropic nematic mesophase. No mesophase was observed for 7a–d. An odd–even effect was observed for 5a–d and 9a–d associated with the crystal to isotropic phase transition and crystal to nematic phase, respectively, as the length of the spacer was increased from 1 to 4 carbon atoms. The transitional properties were higher for odd-numbered members (n = 1 and 3) for all of the series studied. The X-ray data of compounds 5a and 5b are in agreement with polarizing optical microscopy observations with the assignment of an SmC mesophase. Density functional theory calculations using the B3LYP hybrid functional with the level 6-311G(d,p) basis set were performed for molecules 5a–d to correlate the conformation of the flexible spacer and the transitional properties. The conformational analysis showed that the most stable conformation for 5a–d is one where all of the carbon atoms of the flexible spacer are orientated at 180° (antiperiplanar orientation) except for 5a because the spacer is too short. The odd-numbered members have a more bent shape and are less elongated molecules than the even-numbered members. Thus, mesomorphic behavior is dictated by the conformational constraint imposed by the flexible spacer on the mesogenic groups

    Understanding the Impact of Symmetrical Substitution on the Photodynamics of Sinapate Esters Using Gas-Phase Ultrafast Spectroscopy

    Get PDF
    Two model biomimetic systems, ethyl sinapate (ES) and its symmetrical analogue, diethyl 2-(4-hydroxy-3,5-dimethoxybenzylidene)malonate (or diethyl sinapate, DES), are stripped to their core fundamentals through gas-phase spectroscopy to understand the underlying photophysics of photothermal materials. Following photoexcitation to the optically bright S1(ππ*) state, DES is found to repopulate the electronic ground state over three orders of magnitude quicker than its non-symmetrical counterpart, ES. Our XMS-CASPT2 calculations shed light on the experimental results, revealing crucial differences in the potential energy surfaces and conical intersection topography between ES and DES. From this work, a peak conical intersection, seen for DES, shows vital importance for the non-radiative ground state recovery of photothermal materials. This fundamental comparative study highlights the potential impact that symmetrical substitution can have on the photodynamics of sinapate esters, providing a blueprint for future advancement in photothermal technology

    Dietary Fat, Sugar Consumption, and Cardiorespiratory Fitness in Patients With Heart Failure With Preserved Ejection Fraction

    Get PDF
    Heart failure with preserved ejection fraction (HFpEF) is associated with obesity and, indirectly, with unhealthy diet. The role of dietary components in HFpEF is, however, largely unknown. In this study, the authors showed that in obese HFpEF patients, consumption of unsaturated fatty acids (UFA), was associated with better cardiorespiratory fitness, and UFA consumption correlated with better diastolic function and with greater fat-free mass. Similarly, mice fed with a high-fat diet rich in UFA and low in sugars had preserved myocardial function and reduced weight gain. Randomized clinical trials increasing dietary UFA consumption and reducing sugar consumption are warranted to confirm and expand our findings

    Variabilidade das correntes na plataforma interna ao largo de TramandaĂ­, RS durante o verĂŁo de 2014

    Get PDF
    Upwelling and Downwelling events in very shallow water still are poorly understood on brazilian coastal. This work aims to obtain a better understanding of ocean circulation in shallow waters, such as coastal currents and sea level oscillations. An acoustic waves and currents profiler, AWAC, Nortek brand, was anchored at 11 m depth off TramandaĂ­ beach, which was programmed to record a continuous series of waves and currents data, beginning on December 17, 2013 and ending on March 13, 2014 (summer). The results indicated that in the inner shelf the direction of the currents for short periods reverses, sometimes Southward, sometimes Northward. Also, it was observed the maximum velocities of 0.6 and 0.9 m.s-1 on the bottom and on the surface, respectively. In addition, a flow rate of 0.018 m.s-1 to S was calculated based on the average profile of the water column. Furthermore, were found indicative of upwelling and downwelling circulation patterns, from wind and current direction analysis as well, variations in water temperature and also in average sea level.Os fenĂŽmenos da ressurgĂȘncia e subsidĂȘncia costeira em regiĂ”es com pequenas profundidades ainda sĂŁo pouco compreendidos no litoral brasileiro. O presente trabalho visa obter um melhor entendimento das condiçÔes oceanogrĂĄficas em ĂĄguas rasas, tais como as forçantes das correntes costeiras e das oscilaçÔes do nĂ­vel do mar. Um perfilador acĂșstico de ondas e correntes, AWAC, da marca Nortek, foi fundeado a 11 m de profundidade ao largo da praia de TramandaĂ­, programado para registrar uma sĂ©rie contĂ­nua de dados de ondas e correntes, com inĂ­cio em 17 de dezembro de 2013 e tĂ©rmino em 13 de março de 2014 (perĂ­odo do verĂŁo). Os resultados indicaram que a circulação tem inversĂ”es de curto perĂ­odo no sentido das correntes, ora para S, ora para N. TambĂ©m foi possĂ­vel verificar velocidades mĂĄximas de 0,6 e 0,9 m.s-1 no fundo e em superfĂ­cie, respectivamente. Ademais, um fluxo resultante para S, de aproximadamente 0,018 m.s-1 foi calculado com base no perfil mĂ©dio da coluna de ĂĄgua. AlĂ©m disso, foram encontrados indicativos de ressurgĂȘncia e subsidĂȘncia costeira, atravĂ©s das anĂĄlises da direção do vento e das correntes, das variaçÔes na temperatura da ĂĄgua e tambĂ©m do nĂ­vel mĂ©dio do mar

    Headache attributed to aeroplane travel: the first multicentric survey in a paediatric population affected by primary headaches

    Get PDF
    BACKGROUND: This multicentric survey investigates the prevalence and characteristics of Airplane Headache in children affected by primary headaches. METHODS: Patients with symptoms of Airplane Headache were recruited from nine Italian Pediatric Headache Centres. Each patient was handed a structured questionnaire which met the ICHD-III criteria. RESULTS: Among 320 children suffering from primary headaches who had flights during their lifetime, 15 (4.7%) had Airplane Headache, with mean age of 12.4 years. Most of the patients were females (80%). The headache was predominantly bilateral (80%) and localized to the frontal area (60%); it was mainly pulsating, and lasted less than 30 min in all cases. Accompanying symptoms were tearing, photophobia, phonophobia in most of the cases (73.3%). More than 30% of patients used medications to treat the attacks, with good results. CONCLUSION: Our study shows that Airplane Headache is not a rare disorder in children affected by primary headaches and highlights that its features in children are peculiar and differ from those described in adults. In children Airplane Headache prevails in females, is more often bilateral, has frequently accompanying symptoms and occurs at any time during the flight. Further studies are needed to confirm the actual frequency of Airplane Headache in the general pediatric population not selected from specialized Headache Centres, with and without other concomitant headache condition, and to better clarify the clinical characteristics, pathophysiology and potential therapies
    • 

    corecore