Quantum Interference of Force

We show that a quantum particle subjected to a positive force in one path of a Mach-Zehnder interferometer and a null force in the other path may receive a negative average momentum transfer when it leaves the interferometer by a particular exit. In this scenario, an ensemble of particles may receive an average momentum in the opposite direction of the applied force due to quantum interference, a behavior with no classical analogue. We discuss some experimental schemes that could verify the effect with current technology, with electrons or neutrons in Mach-Zehnder interferometers in free space and with atoms from a Bose-Einstein condensate.Comment: 5 figures. Accepted in Quantum on 2018-12-0

Image forgery detection via forensic similarity graphs

In the article 'Exposing Fake Images with Forensic Similarity Graphs', O. Mayer and M. C. Stamm introduce a novel image forgery detection method. The proposed method is built on a graph-based representation of images, where image patches are represented as the vertices of the graph, and the edge weights are assigned in order to reflect the forensic similarity between the connected patches. In this representation, forged regions form highly connected subgraphs. Therefore, forgery detection and localization can be cast as a cluster analysis problem on the similarity graph. The authors present two graph clustering methods to detect and localize image forgeries. In this paper, we present briefly the method and offer an online executable version allowing everyone to test it on their own suspicious images.Projecto ANR-16-DEFA-0004Proyecto vera.ai (101070093

Escherichia coli EHEC Germany outbreak preliminary functional annotation using BG7 system

We have annotated the European outbreak E. coli EHEC genome sequenced by BGI (6-2-2011) and assembled with MIRA by Nick Loman (6-2-2011 ). Our system BG7, Bacterial Genome annotation of Era7 Bioinformatics, predicts ORFs and annotates them based on fragments of similarity with Uniprot proteins. We have predicted 6327 genes, 6156 encoding proteins y 171 corresponding to ribosomal and tRNA. Based on the preliminary results of our semi-automated method of annotation we have selected some predicted proteins with potential implications in pathogenicity and virulence.
There are 33 predicted genes annotated as toxins and we have found three putative hemolysins: Hemolysin E, a putative hemolysin expression modulating protein and a channel protein, hemolysin III family. We have found 31 predicted genes that could be related to specific antibiotic resistance: beta-lactamic, aminoglycoside, macrolide, polymyxin, tetracycline, fosfomycin and deoxycholate, novobiocin, chloramphenicol, bicyclomycin, norfloxacin and enoxacin and 6-mercaptopurine. This strain is rich in adhesion, secretion systems, pathogenicity and virulence related proteins. It seems to have a restriction-modification system, many proteins involved in Fe transport and utilization (siderophores as aerobactin and enterobactin), lysozyme, one inhibitor of pancreatic serine proteases, proteins involved in anaerobic respiration, antimicrobial peptides, and proteins involved in quorum sensing and biofilm formation that could confer competitive advantage to this strain

Forensic similarity for source camera model comparison

In the article 'Forensic Similarity for Digital Images', O. Mayer and M. C. Stamm introduce the forensic similarity approach, which aims at determining whether two image patches contain the same forensic traces or not. The proposed method is based on a feed-forward neural network which consists of two modules : a feature extraction module using a pair of CNNs in a siamese configuration, and a three-layer neural network that maps the extracted features into a similarity score. In this article, we explore the use of the forensic similarity score for source camera model comparison, as one of the possible applications of such an approach suggested by Mayer and Stamm.Proyecto ANR-DGA (ANR-16-DEFA-0004)Proyecto vera.ai (101070093

Characterization of Laser-Induced Plasmas Of Organic Compounds by spatially- and temporally resolved optical emission spectrometry

The large majority of laser-induced plasmas experiments are performed on metals in air at atmospheric pressure, where recombination mechanisms do not play a significant role, as the primary emission lines of interest are significantly more intense than those derived from recombination with air, particularly those yielding oxides. Due to the large number of electronic transitions commonly attainable on metals, many intense emission lines are recorded and different regions of interest useful for identification and quantification purposes may be assigned. The main difficulties in the interpretation of the molecular emission of species containing C, N, O or H relies on the questions concerning their origin: direct release from native bonds or recombination with ambient constituents. In other words: does the resultant spectrum mimic the structure of a molecule or the molecular information gets lost in the course of the secondary reactions? Considering that the spectrum observed is always a convolution of primary and secondary processes, experiments in vacuum or in controlled atmospheres may help to address such questions. The present work shows detailed experiments where spatially- and temporally-resolved optical emission spectroscopy of laser-produced plasmas on organic compounds has been performed. The experiments cover a pressure range from 1000 mbar to 10-3 mbar that allows a precise observation of the effect of the surrounding atmosphere in the formation of species by recombination.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The extremal Kerr entropy in higher-derivative gravities

We investigate higher derivative corrections to the extremal Kerr black hole in the context of heterotic string theory with $\alpha'$ corrections and of a cubic-curvature extension of general relativity. By analyzing the near-horizon extremal geometry of these black holes, we are able to compute the Iyer-Wald entropy as well as the angular momentum via generalized Komar integrals. In the case of the stringy corrections, we obtain the physically relevant relation $S(J)$ at order $\alpha'^2$. On the other hand, the cubic theories, which are chosen as Einsteinian cubic gravity plus a new odd-parity density with analogous features, possess special integrability properties that enable us to obtain exact results in the higher-derivative couplings. This allows us to find the relation $S(J)$ at arbitrary orders in the couplings and even to study it in a non-perturbative way. We also extend our analysis to the case of the extremal Kerr-(A)dS black hole.Comment: 33 pages+appendices, one figur