Ultrarobust calibration of an optical lattice depth based on a phase shift

We report on a new method to calibrate the depth of an optical lattice. It consists in triggering the intrasite dipole mode of the cloud by a sudden phase shift. The corresponding oscillatory motion is directly related to the intraband frequencies on a large range of lattice depths. Remarkably, for a moderate displacement, a single frequency dominates this oscillation for the zeroth and first order interference pattern observed after a sufficiently long time-of-flight. The method is robust against atom-atom interactions and the exact value of the extra external confinement of the initial trapping potential.Comment: 7 pages, 6 figure

Control of a multi-axis platform for metrological purposes using diferential flatness

Positioning and tracking devices with micrometer range and sub-micrometer resolution are becoming of special interest in recent years for an extending range of applications including metrological devices, manipulators and mechanization systems both in research and high precision industries (for example, semiconductors). The control of these systems is not an easy task because of its normally high stiffness and the coupling existing between the different degrees of freedom. The present work proposes a control strategy based on differential flatness for static positioning and dynamic trajectory tracking with a platform of three degrees of freedom. The system uses piezoelectric actuators and is specially conceived for metrological devices, which do not suffer important external loads. The proposed method permits to decouple the design of a closed loop control for each degree of freedom and calculates an open loop command directly from the trajectory definition in the three degrees of freedom. The performance of the controller has been experimentally checked both in positioning and tracking applications

Optical Flow Estimation in the Deep Learning Age

Akin to many subareas of computer vision, the recent advances in deep learning have also significantly influenced the literature on optical flow. Previously, the literature had been dominated by classical energy-based models, which formulate optical flow estimation as an energy minimization problem. However, as the practical benefits of Convolutional Neural Networks (CNNs) over conventional methods have become apparent in numerous areas of computer vision and beyond, they have also seen increased adoption in the context of motion estimation to the point where the current state of the art in terms of accuracy is set by CNN approaches. We first review this transition as well as the developments from early work to the current state of CNNs for optical flow estimation. Alongside, we discuss some of their technical details and compare them to recapitulate which technical contribution led to the most significant accuracy improvements. Then we provide an overview of the various optical flow approaches introduced in the deep learning age, including those based on alternative learning paradigms (e.g., unsupervised and semi-supervised methods) as well as the extension to the multi-frame case, which is able to yield further accuracy improvements.Comment: To appear as a book chapter in Modelling Human Motion, N. Noceti, A. Sciutti and F. Rea, Eds., Springer, 202

A new fluorescent oligonucleotide probe for in-situ identification of Microcystis aeruginosa in freshwater.

contaminated water bodies (freshwater, brackish and marine areas). Among 150 known cyanobacteria genera,>40 species are able to produce toxins, which are natural compounds that differ from both a chemical and toxicological point of view and are responsible for acute and chronic poisoning in animals and humans. Among the main classes of cyanotoxins, microcystins are frequently found in the environment. Fast and accurate methods for unequivocally identifying microcystin-producing cyanobacteria, such as Microcystis aeruginosa in water bodies, are necessary to distinguish them from other non-toxic cyanobacteria and to manage and monitor algal blooms. For this purpose, we designed, developed and validated an oligonucleotide probe for FISH (Fluorescence In Situ Hybridization) analysis to detect Microcystis aeruginosa at the species level even at relatively low concentrations in freshwater. The FISH probe, MicAerD03, was designed using the ARB software with the Silva database within the framework of the MicroCoKit project, also with the intention of adding it to the microarray from the EU project, μAQUA, for freshwater pathogens, which had only genus level probes for Microcystis. We tested various fixative methods to minimize the natural autofluorescence from chlorophyll-a and certain accessory pigments (viz., phycobilins and carotenoids). The FISH probe was tested on pure cultures of Microcystis aeruginosa, and then successfully applied to water samples collected from different sampling points of the Tiber River (Italy), using a laser confocal microscope. Subsequently, the probe was also conjugated at the 5′ end with horse-radish peroxidase (HRP-MicAerD03) to apply the CAtalysed Reported Deposition-FISH (CARD-FISH) for increasing the fluorescence signal of the mono-fluorescently labelled probe and make it possible to detect M. aeruginosa using an epifluorescence microscope. Samples taken within the EU MicroCokit project indicated thatmicroarray signals for Microcystis were coming from single cells and not colonial cells. We confirmed this with the CARD-FISH protocol used here to validate the microarray signals for Microcystis detected at the genus level in MicroCokit. This paper provides a new early warning tool for investigating M. aeruginosa at the species level even at low cell concentrations in surface water, which can be added to the μAqua microarray for all freshwater pathogens to complete the probe hierarchy for Microcystis aeruginosa

Invasive pulmonary aspergillosis in patients with decompensated cirrhosis: case series

BACKGROUND: Opportunistic invasive fungal infections are increasingly frequent in intensive care patients. Their clinical spectrum goes beyond the patients with malignancies, and for example invasive pulmonary aspergillosis has recently been described in critically ill patients without such condition. Liver failure has been suspected to be a risk factor for aspergillosis. CASE PRESENTATION: We describe three cases of adult respiratory distress syndrome with sepsis, shock and multiple organ failure in patients with severe liver failure among whom two had positive Aspergillus antigenemia and one had a positive Aspergillus serology. In all cases bronchoalveolar lavage fluid was positive for Aspergillus fumigatus. Outcome was fatal in all cases despite treatment with voriconazole and agressive symptomatic treatment. CONCLUSION: Invasive aspergillosis should be among rapidly raised hypothesis in cirrhotic patients developing acute respiratory symptoms and alveolar opacities

Smear microscopy and culture conversion rates among smear positive pulmonary tuberculosis patients by HIV status in Dar es Salaam, Tanzania

Tanzania ranks 15th among the world's 22 countries with the largest tuberculosis burden and tuberculosis has continued to be among the major public health problems in the country. Limited data, especially in patients co infected with HIV, are available to predict the duration of time required for a smear positive pulmonary tuberculosis patient to achieve sputum conversion after starting effective treatment. In this study we assessed the sputum smear and culture conversion rates among HIV positive and HIV negative smear positive pulmonary tuberculosis patients in Dar es Salaam The study was a prospective cohort study which lasted for nine months, from April to December 2008 A total of 502 smear positive pulmonary tuberculosis patients were recruited. HIV test results were obtained for 498 patients, of which 33.7% were HIV positive. After two weeks of treatment the conversion rate by standard sputum microscopy was higher in HIV positive(72.8%) than HIV negative(63.3%) patients by univariate analysis(P = 0.046), but not in multivariate analysis. Also after two weeks of treatment the conversion rate by fluorescence microscopy was higher in HIV positive (72.8%) than in HIV negative(63.2%) patients by univariate analysis (P = 0.043) but not in the multivariate analysis. The conversion rates by both methods during the rest of the treatment period (8, 12, and 20 weeks) were not significantly different between HIV positive and HIV negative patients.With regards to culture, the conversion rate during the whole period of the treatment (2, 8, 12 and 20 weeks) were not significantly different between HIV positive and HIV negative patients.\ud Conversion rates of standard smear microscopy, fluorescence microscopy and culture did not differ between HIV positive and HIV negative pulmonary tuberculosis patients

Model-based mechanical and control design of a three-axis platform

In recent times, the interest from scientific and industrial community for the micrometric range has observed an important growth. The advances in microelectronics or the research on microbiology are just two examples of fields requiring technologies capable of assuring accurate displacements in that range. The present work focuses on the mechanical and control design of a micrometer range positioning and tracking platform using mathematical models. In a first phase, these models permit to identify the relationship between the dynamic performance of the structure and the mechanical properties of the elements that compose it. At the very beginning of the design, this information is used for the development of the different parts of the platform. Afterwards, once an initial design is finished and 3D models are available, the design is refined using finite element tools. In parallel to the mechanical design, the knowledge of the system embodied in the mathematical model is profited in the design of a control strategy for tracking and positioning. The proposed control strategy combines a linear controller based on differential flatness with a hysteresis compensator for correcting this nonlinear effect of the piezoelectric actuators. In the present paper, the mathematical derivation of the system model, its application to the design and validation of the platform and the final closed loop experimental evaluation are described