Provenance analysis for instagram photos

As a feasible device fingerprint, sensor pattern noise (SPN) has been proven to be effective in the provenance analysis of digital images. However, with the rise of social media, millions of images are being uploaded to and shared through social media sites every day. An image downloaded from social networks may have gone through a series of unknown image manipulations. Consequently, the trustworthiness of SPN has been challenged in the provenance analysis of the images downloaded from social media platforms. In this paper, we intend to investigate the effects of the pre-defined Instagram images filters on the SPN-based image provenance analysis. We identify two groups of filters that affect the SPN in quite different ways, with Group I consisting of the filters that severely attenuate the SPN and Group II consisting of the filters that well preserve the SPN in the images. We further propose a CNN-based classifier to perform filter-oriented image categorization, aiming to exclude the images manipulated by the filters in Group I and thus improve the reliability of the SPN-based provenance analysis. The results on about 20, 000 images and 18 filters are very promising, with an accuracy higher than 96% in differentiating the filters in Group I and Group II

Designing materials for electrochemical carbon dioxide recycling

Electrochemical carbon dioxide recycling provides an attractive approach to synthesizing fuels and chemical feedstocks using renewable energy. On the path to deploying this technology, basic and applied scientific hurdles remain. Integrating catalytic design with mechanistic understanding yields scientific insights and progresses the technology towards industrial relevance. Catalysts must be able to generate valuable carbon-based products with better selectivity, lower overpotentials and improved current densities with extended operation. Here, we describe progress and identify mechanistic questions and performance metrics for catalysts that can enable carbon-neutral renewable energy storage and utilization

BeFaced: A casual game to crowdsource facial expressions in the wild

Creating good quality image databases for affective computing systems is key to most computer vision research, but is unfortunately costly and time-consuming. This paper describes BeFaced, a tile matching casual tablet game that enables massive crowdsourcing of facial expressions to advance facial expression analysis. BeFaced uses state-of-the-art facial expression tracking technology with dynamic difficulty adjustment to keep the player engaged and hence obtain a large and varied face dataset. CHI attendees will be able to experience a novel game interface that uses the iPad's front camera to track and capture facial expressions as the primary player input, and also investigate how the game design in general enables massive crowdsourcing in an extensible manner

A Relational Event Approach to Modeling Behavioral Dynamics

This chapter provides an introduction to the analysis of relational event data (i.e., actions, interactions, or other events involving multiple actors that occur over time) within the R/statnet platform. We begin by reviewing the basics of relational event modeling, with an emphasis on models with piecewise constant hazards. We then discuss estimation for dyadic and more general relational event models using the relevent package, with an emphasis on hands-on applications of the methods and interpretation of results. Statnet is a collection of packages for the R statistical computing system that supports the representation, manipulation, visualization, modeling, simulation, and analysis of relational data. Statnet packages are contributed by a team of volunteer developers, and are made freely available under the GNU Public License. These packages are written for the R statistical computing environment, and can be used with any computing platform that supports R (including Windows, Linux, and Mac).

Elastin is Localised to the Interfascicular Matrix of Energy Storing Tendons and Becomes Increasingly Disorganised With Ageing

Tendon is composed of fascicles bound together by the interfascicular matrix (IFM). Energy storing tendons are more elastic and extensible than positional tendons; behaviour provided by specialisation of the IFM to enable repeated interfascicular sliding and recoil. With ageing, the IFM becomes stiffer and less fatigue resistant, potentially explaining why older tendons become more injury-prone. Recent data indicates enrichment of elastin within the IFM, but this has yet to be quantified. We hypothesised that elastin is more prevalent in energy storing than positional tendons, and is mainly localised to the IFM. Further, we hypothesised that elastin becomes disorganised and fragmented, and decreases in amount with ageing, especially in energy storing tendons. Biochemical analyses and immunohistochemical techniques were used to determine elastin content and organisation, in young and old equine energy storing and positional tendons. Supporting the hypothesis, elastin localises to the IFM of energy storing tendons, reducing in quantity and becoming more disorganised with ageing. These changes may contribute to the increased injury risk in aged energy storing tendons. Full understanding of the processes leading to loss of elastin and its disorganisation with ageing may aid in the development of treatments to prevent age related tendinopathy

Covering Partial Cubes with Zones

A partial cube is a graph having an isometric embedding in a hypercube. Partial cubes are characterized by a natural equivalence relation on the edges, whose classes are called zones. The number of zones determines the minimal dimension of a hypercube in which the graph can be embedded. We consider the problem of covering the vertices of a partial cube with the minimum number of zones. The problem admits several special cases, among which are the problem of covering the cells of a line arrangement with a minimum number of lines, and the problem of finding a minimum-size fibre in a bipartite poset. For several such special cases, we give upper and lower bounds on the minimum size of a covering by zones. We also consider the computational complexity of those problems, and establish some hardness results

Approximately coloring graphs without long induced paths

It is an open problem whether the 3-coloring problem can be solved in polynomial time in the class of graphs that do not contain an induced path on $t$ vertices, for fixed $t$. We propose an algorithm that, given a 3-colorable graph without an induced path on $t$ vertices, computes a coloring with $\max\{5,2\lceil{\frac{t-1}{2}}\rceil-2\}$ many colors. If the input graph is triangle-free, we only need $\max\{4,\lceil{\frac{t-1}{2}}\rceil+1\}$ many colors. The running time of our algorithm is $O((3^{t-2}+t^2)m+n)$ if the input graph has $n$ vertices and $m$ edges

Recherche et Titrage des Hémolysines Anti-A et Anti-B Chez Les Femmes en periode du postpartum immédiat au Centre Hospitalier et Universitaire de Yaoundé

But de l’étudeLes hémolysines apparaissent suite à une immunisation ABO et peuvent causer, à titre élevé, une hémolyse chez le receveur de sang ou chez le nouveau-né. Cette étude avait pour but de déterminer la fréquence et le titre des hémolysines anti-A et anti-B chez les femmes en période du post-partum immédiat ainsi que les facteurs de risque associés au Centre Hospitalier et Universitaire de Yaoundé.Patients et MéthodesUne étude descriptive et transversale a été menée chez les mères et leurs nouveau-nés. Les groupes sanguins ABO ont été déterminés chez tous les participants. Chez les mères, la recherche et titrage des hémolysines a été faite par la technique d’hémolyse en présence ducomplément à 37°C pendant 30 minutes. Les Khi carrés de Pearson et de Mentel-Haenszel ont servis pour des tests statistiques. Une valeur p<0,05 représentait une différence statistiquement significative. RésultatsSur 251 cas, après groupage sanguin ABO, Cinq mères de groupe AB ont été exclues et 246 retenues pour la recherche d’hémolysines. La fréquence de l’incompatibilité foeto-maternelle ABO était de 22,76% et celle des hémolysines était de 26,8%. Les hémolysines anti-A, anti-B et anti-AB ont été retrouvées respectivement dans 15%, 18,7% et 6,9% des cas. Les titres les plus élevés étaient ceux d’hémolysines anti-A. Les facteurs de risque comprenaient le mariage (p=0,01), la multiparité (p=0,02), le groupe sanguin des mères (p=0,02) et l’incompatibilité foeto-maternelle ABO (p<0,001).ConclusionCes résultats suggèrent la nécessité d’introduire la recherche systématique des hémolysines parmi les tests de suivi immunohématologique des femmes enceintes camerounaises.Mots Clés: Hémolysines anti-A et anti-A, Incompatibilité foeto-maternelle ABO, Maladie hémolytique du nouveau-né, Période du post-partum immédiate