Transcytosis in MDCK cells: identification of glycoproteins transported bidirectionally between both plasma membrane domains.

MDCK cells display fluid-phase transcytosis in both directions across the cell. Transcytosis of cell surface molecules was estimated by electron microscopic analysis of streptavidin-gold-labeled frozen sections of biotinylated cells. Within 3 h, approximately 10% of the surface molecules, biotinylated on the starting membrane domain, were detected on the opposite surface domain irrespective of the direction of transcytosis. This suggests that the transcytosis rates for surface molecules are equal in both directions across the cell as shown previously for fluid-phase markers

PCA-RECT: An Energy-efficient Object Detection Approach for Event Cameras

We present the first purely event-based, energy-efficient approach for object detection and categorization using an event camera. Compared to traditional frame-based cameras, choosing event cameras results in high temporal resolution (order of microseconds), low power consumption (few hundred mW) and wide dynamic range (120 dB) as attractive properties. However, event-based object recognition systems are far behind their frame-based counterparts in terms of accuracy. To this end, this paper presents an event-based feature extraction method devised by accumulating local activity across the image frame and then applying principal component analysis (PCA) to the normalized neighborhood region. Subsequently, we propose a backtracking-free k-d tree mechanism for efficient feature matching by taking advantage of the low-dimensionality of the feature representation. Additionally, the proposed k-d tree mechanism allows for feature selection to obtain a lower-dimensional dictionary representation when hardware resources are limited to implement dimensionality reduction. Consequently, the proposed system can be realized on a field-programmable gate array (FPGA) device leading to high performance over resource ratio. The proposed system is tested on real-world event-based datasets for object categorization, showing superior classification performance and relevance to state-of-the-art algorithms. Additionally, we verified the object detection method and real-time FPGA performance in lab settings under non-controlled illumination conditions with limited training data and ground truth annotations.Comment: Accepted in ACCV 2018 Workshops, to appea

Energy sustainability in teaching and outreach initiatives and the contribution to the 2030 Agenda

© 2020, Emerald Publishing Limited. Purpose: Considering the different roles universities can perform to contribute to sustainable development, it is through teaching and outreach that they might be able to connect to the academic and local communities the most. The purpose of this study is to investigate the extent to which energy sustainability is being considered in campus teaching and outreach activities of different higher education institutions worldwide. In this context, this exploratory study was developed. Design/methodology/approach: Through an online survey, a group of 36 universities from all continents was inquired about the level of sustainability in energy aspects of teaching and outreach activities, including curriculum change, training courses for staff and the regularity of outreach projects. Findings: The results allowed global analysis concerning challenges and opportunities of these educational activities. This study also touches upon the interconnection between these practices and the contribution of universities towards the 2030 Agenda, and how universities can expand their activities and contribute practically to society. In terms of practical contributions, this study provides recommendations for higher education institutions to develop further in the area of energy sustainability through teaching and outreach. Originality/value: Energy is a sustainability aspect relatively well covered by actions on campus operations, but there is a paucity of studies connecting this topic to teaching and outreach activities. This study is an approach to not only fill this gap but also reinforce the university role and contribution to the Sustainable Development Goals

Video synthesis from Intensity and Event Frames

Event cameras, neuromorphic devices that naturally respond to brightness changes, have multiple advantages with respect to traditional cameras. However, the difficulty of applying traditional computer vision algorithms on event data limits their usability. Therefore, in this paper we investigate the use of a deep learning-based architecture that combines an initial grayscale frame and a series of event data to estimate the following intensity frames. In particular, a fully-convolutional encoder-decoder network is employed and evaluated for the frame synthesis task on an automotive event-based dataset. Performance obtained with pixel-wise metrics confirms the quality of the images synthesized by the proposed architecture

Low-temperature far-infrared ellipsometry of convergent beam

Development of an ellipsometry to the case of a coherent far infrared irradiation, low temperatures and small samples is described, including a decision of the direct and inverse problems of the convergent beam ellipsometry for an arbitrary wavelength, measurement technique and a compensating orientation of cryostat windows. Experimental results are presented: for a gold film and UBe13 single crystal at room temperature (lambda=119 um), temperature dependencies of the complex dielectric function of SrTiO3 (lambda=119, 84 and 28 um) and of YBa2Cu3O7-delta ceramic (lambda=119 um).Comment: 14 pages, 6 figure

Sustainable development goals: a framework for deploying indicators for higher education institutions

Purpose: This paper aims to analyse the extent to which the sustainable development goals (SDGs) are being considered at higher education institutions (HEIs) and propose and test the possible acceptance of a list of indicators to evaluate the contribution of HEIs to the SDGs. Design/methodology/approach: The methodology consisted of the collection of indicators of sustainable development based on the existing bibliography. Afterwards, a set of indicators related to the SDGs were selected, based on the most frequent SDGs’ expressions found in the selected indicators. A sample of researchers was also asked to indicate to which extent this set of indicators is perceived as relevant. Findings: The results indicated an initial list with 432 indicators, of which 268 were selected for having at least one of the keywords searched for, related to the SDG descriptions and targets. Thus, redundant indicators were excluded and, when necessary, indicators were aggregated, resulting in a final list of 61 indicators. Originality/value: The set of indicators resulted from this analysis was considered appropriate to evaluate the contribution of HEIs towards the SDGs, demonstrating that it might not be necessary to create new indicators for that purpose

Reference values for methacholine reactivity (SAPALDIA study)

BACKGROUND: The distribution of airway responsiveness in a general population of non-smokers without respiratory symptoms has not been established, limiting its use in clinical and epidemiological practice. We derived reference equations depending on individual characteristics (i.e., sex, age, baseline lung function) for relevant percentiles of the methacholine two-point dose-response slope. METHODS: In a reference sample of 1567 adults of the SAPALDIA cross-sectional survey (1991), defined by excluding subjects with respiratory conditions, responsiveness during methacholine challenge was quantified by calculating the two-point dose-response slope (O'Connor). Weighted L1-regression was used to estimate reference equations for the 95(th ), 90(th ), 75(th )and 50(th )percentiles of the two-point slope. RESULTS: Reference equations for the 95(th ), 90(th ), 75(th )and 50(th )percentiles of the two-point slope were estimated using a model of the form a + b* Age + c* FEV(1 )+ d* (FEV(1))(2 ), where FEV(1 )corresponds to the pre-test (or baseline) level of FEV(1). For the central half of the FEV(1 )distribution, we used a quadratic model to describe the dependence of methacholine slope on baseline FEV(1). For the first and last quartiles of FEV(1), a linear relation with FEV(1 )was assumed (i.e., d was set to 0). Sex was not a predictor term in this model. A negative linear association with slope was found for age. We provide an Excel file allowing calculation of the percentile of methacholine slope of a subject after introducing age – pre-test FEV(1 )– and results of methacholine challenge of the subject. CONCLUSION: The present study provides equations for four relevant percentiles of methacholine two-point slope depending on age and baseline FEV(1 )as basic predictors in an adult reference population of non-obstructive and non-atopic persons. These equations may help clinicians and epidemiologists to better characterize individual or population airway responsiveness

Asynchronous, Photometric Feature Tracking using Events and Frames

We present a method that leverages the complementarity of event cameras and standard cameras to track visual features with low-latency. Event cameras are novel sensors that output pixel-level brightness changes, called "events". They offer significant advantages over standard cameras, namely a very high dynamic range, no motion blur, and a latency in the order of microseconds. However, because the same scene pattern can produce different events depending on the motion direction, establishing event correspondences across time is challenging. By contrast, standard cameras provide intensity measurements (frames) that do not depend on motion direction. Our method extracts features on frames and subsequently tracks them asynchronously using events, thereby exploiting the best of both types of data: the frames provide a photometric representation that does not depend on motion direction and the events provide low-latency updates. In contrast to previous works, which are based on heuristics, this is the first principled method that uses raw intensity measurements directly, based on a generative event model within a maximum-likelihood framework. As a result, our method produces feature tracks that are both more accurate (subpixel accuracy) and longer than the state of the art, across a wide variety of scenes.Comment: 22 pages, 15 figures, Video: https://youtu.be/A7UfeUnG6c

Sustainable Development Policies as Indicators and Pre-Conditions for Sustainability Efforts at Universities: fact or fiction?

Purpose - There is a widely held belief that Sustainable Development (SD) policies are essential for universities to successfully engage in matters related to sustainability, and are an indicator of the extent to which they are active in this field. This paper examines the evidence which currently exists to support this assumption. It surveys a sample of universities in Brazil, Germany, Greece, Portugal, South Africa, United Kingdom (UK) and United States of America (USA) to ascertain the extent to which universities that are active in the field of sustainable development have formal policies on sustainable development, and whether such policies are a pre-condition for successful sustainability efforts. Design/methodology/approach –The study involved 35 universities in these seven countries (five universities respectively). A mixed-methods approach has been used, ranging from document analysis, website analysis, questionnaires and interviewing. Findings – Although only 60% of the sampled universities had a policy that specifically addressed SD, this cannot be regarded as an indicator that the remaining 40% are not engaged with substantial actions that address SD. Indeed, all of the universities in the sample, regardless of the existence of a SD formal policy, demonstrated engagement with environmental sustainability policies or procedures in some form or another. This research has been limited by the availability and ability to procure information from the sampled universities. Despite this, it is one of the largest research efforts of this kind ever performed. Originality/value – Our findings provide some valuable insights about the connections between SD policies on the one hand, and the practice of SD in higher education institutions on the other

Semi-Dense 3D Reconstruction with a Stereo Event Camera

Event cameras are bio-inspired sensors that offer several advantages, such as low latency, high-speed and high dynamic range, to tackle challenging scenarios in computer vision. This paper presents a solution to the problem of 3D reconstruction from data captured by a stereo event-camera rig moving in a static scene, such as in the context of stereo Simultaneous Localization and Mapping. The proposed method consists of the optimization of an energy function designed to exploit small-baseline spatio-temporal consistency of events triggered across both stereo image planes. To improve the density of the reconstruction and to reduce the uncertainty of the estimation, a probabilistic depth-fusion strategy is also developed. The resulting method has no special requirements on either the motion of the stereo event-camera rig or on prior knowledge about the scene. Experiments demonstrate our method can deal with both texture-rich scenes as well as sparse scenes, outperforming state-of-the-art stereo methods based on event data image representations.Comment: 19 pages, 8 figures, Video: https://youtu.be/Qrnpj2FD1e