A comparison of new measurements of total monoterpene flux with improved measurements of speciated monoterpene flux

International audienceMany monoterpenes have been identified in forest emissions using gas chromatography (GC). Until now, it has been impossible to determine whether all monoterpenes are appropriately measured using GC techniques. We used a proton transfer reaction mass spectrometer (PTR-MS) coupled with the eddy covariance (EC) technique to measure mixing ratios and fluxes of total monoterpenes above a ponderosa pine plantation. We compared PTR-MS-EC results with simultaneous measurements of eight speciated monoterpenes, ?-pinene, ?-pinene, 3-carene, d-limonene, ?-phellandrene, ?-terpinene, camphene, and terpinolene, made with an automated, in situ gas chromatograph with flame ionization detectors (GC-FID), coupled to a relaxed eddy accumulation system (REA). Monoterpene mixing ratios and fluxes measured by PTR-MS averaged 30±2.3% and 31±9.2% larger than by GC-FID, with larger mixing ratio discrepancies between the two techniques at night than during the day. Two unidentified peaks that correlated with ?-pinene were resolved in the chromatograms and completely accounted for the daytime difference and reduced the nighttime mixing ratio difference to 20±2.9%. Measurements of total monoterpenes by PTR-MS-EC indicated that GC-FID-REA measured the common, longer-lived monoterpenes well, but that additional terpenes were emitted from the ecosystem that represented an important contribution to the total mixing ratio above the forest at night

Cooperative subwavelength molecular quantum emitter arrays

Dipole-coupled subwavelength quantum emitter arrays respond cooperatively to external light fields as they may host collective delocalized excitations (a form of excitons) with super- or subradiant character. Deeply subwavelength separations typically occur in molecular ensembles, where in addition to photon-electron interactions, electron-vibron couplings and vibrational relaxation processes play an important role. We provide analytical and numerical results on the modification of super- and subradiance in molecular rings of dipoles including excitations of the vibrational degrees of freedom. While vibrations are typically considered detrimental to coherent dynamics, we show that molecular dimers or rings can be operated as platforms for the preparation of long-lived dark superposition states aided by vibrational relaxation. In closed ring configurations, we extend previous predictions for the generation of coherent light from ideal quantum emitters to molecular emitters, quantifying the role of vibronic coupling onto the output intensity and coherence

Characterizing Scales of Genetic Recombination and Antibiotic Resistance in Pathogenic Bacteria Using Topological Data Analysis

Pathogenic bacteria present a large disease burden on human health. Control of these pathogens is hampered by rampant lateral gene transfer, whereby pathogenic strains may acquire genes conferring resistance to common antibiotics. Here we introduce tools from topological data analysis to characterize the frequency and scale of lateral gene transfer in bacteria, focusing on a set of pathogens of significant public health relevance. As a case study, we examine the spread of antibiotic resistance in Staphylococcus aureus. Finally, we consider the possible role of the human microbiome as a reservoir for antibiotic resistance genes.Comment: 12 pages, 6 figures. To appear in AMT 2014 Special Session on Advanced Methods of Interactive Data Mining for Personalized Medicin

Use of a fluorescent bile acid to enhance visualization of the biliary tract and bile leaks during laparoscopic surgery in rabbits

Background: We set out to determine whether intravenously administered cholylglycylaminofluorescein (CGF), a fluorescent bile acid, would enhance the visualization of the biliary tract and bile leaks in rabbits undergoing laparoscopic cholecystectomy (LC). Methods: CGF was infused at doses of 1, 5, and 10 mg/kg b.w. Biliary recovery was determined spectrophotometrically (six rabbits). For LC (seven rabbits), a blue (fluorescein) filter was attached to the light source, and a fluorescein-emission filter was attached to the charge coupled device (CCD) camera. The biliary tract and bile leak (made by incising the gallbladder) was observed under standard and fluorescent illumination. Results: Apple-green fluorescence appeared in 2 min and persisted for 30-60 min, enhancing visualization of bile duct anatomy as well as the bile leak. Biliary recovery of CGF at 90 min was high (86-96% of the infused dose). Conclusion: In rabbits, CGF is secreted quantitatively in bile, induces biliary fluorescence, and enhances visualization of the bile ducts and bile leaks when viewed with appropriate filter

Interaction Design of Augmented Education Environments - Augmented and Mixed Reality for performance and training support of Aviation / Automotive Technicians.

"Augmented reality (AR),Mixed Reality (MR) and their mix and combination with other disruptive technologies offer an enormous potential for supporting instructors and trainees in modern education and working environments such as of aircraft maintenance technicians or automotive service technicians. In this paper we investigate and show some examples on how the performance and training of such instructors and trainees can be actively supported. Furthermore we will discuss the new challenges for training designers. The augmentation of the physical world with interactive, context-aware information (e.g. 2D and 3D content) provides multifaceted possibilities, on various ubiquitous and pervasive computing environments. While there is still the broad opinion that these concepts are just situated in the world of science fiction (SciFi) and SciFi movies, we will relate these techniques to existing technologies and prototypes in research. Terms like outernet, print + or 2.0, augmented goggles, wearable technology are not just remaining pure buzzwords anymore. We will demonstrate how different prototypes applying low cost rapid prototyping methods can be applied as powerful performance assistance and training support instruments, whereby discussing the requirements and user-needs analysis phases as well as human–computer interaction and interaction design issues, user modelling, usability engineering, prototyping and evaluation issues. Different scenarios are possible and provide the basis to generate storyboards. One of the key factors is hereby to analyse typical tasks and activities of users and utilize familiar user interaction paradigms for accessing information, such as using a book or assisting the work with task sheets. For example by augmenting the material that is printed in the book with additional graphical 3D interactive information which can be viewed and manipulated by the instructor and/or trainee, one can provide a link between traditional learning and technology-enhanced learning. Basing on theoretical and empirical research it is possible then to design via first moodboards and scribbles relevant prototypes. A qualitative and quantitative analysis can be used to define a basic design process for such new environments and settings. Moreover, MR and AR along with Mobile Tagging (MT) combined with Pervasive Computing provide the possibility to realize a Physical World Connection (PWC) between Reality and Virtuality. In the field of aviation and automotive industry, this offers manifold possibilities for maintenance and service personnel to get access to assistive technologies in a very intuitive way to enhance their operation, work, training, and knowledge. Assistance for the large variety of job tasks can be provided to a certain extent by offering augmentation of the different senses like vision and audition, providing a media-rich interface. Although the roots of Mixed Reality and Augmented Reality are based on prototype applications in the aircraft industry in the early 1990s, the impact of these emerging technologies on special target groups has not yet been investigated and validated by many research groups. With a specific focus on these user communities, applications are considerably more influenced by both usefulness and usability of technology. Consequently, it is argued that key issues in developing such applications are the tracking methodology, the display technology, interaction (devices and framework) and most of all ensuring good usability. In this paper, a concrete example in a aviation and automotive environment will be presented as a case study for investigating and validating these key issues. Preliminary results of semi-structured interviews and observations in real training and work settings indicate a lack of information concerning existence of such technologies and environments, but show big interest and potential for such educational and workplace innovations, while concrete visions or user requirements for future augmented education environments remain open and are subject of our further research steps

Observations of oxidation products above a forest imply biogenic emissions of very reactive compounds

International audienceVertical gradients of mixing ratios of volatile organic compounds have been measured in a Ponderosa pine forest in Central California (38.90° N, 120.63° W, 1315m). These measurements reveal large quantities of previously unreported oxidation products of short lived biogenic precursors. The emission of biogenic precursors must be in the range of 13-66µmol m-2h-1 to produce the observed oxidation products. That is 6-30 times the emissions of total monoterpenes observed above the forest canopy on a molar basis. These reactive precursors constitute a large fraction of biogenic emissions at this site, and are not included in current emission inventories. When oxidized by ozone they should efficiently produce secondary aerosol and hydroxyl radicals

On the challenges and opportunities in visualization for machine learning and knowledge extraction: A research agenda

We describe a selection of challenges at the intersection of machine learning and data visualization and outline a subjective research agenda based on professional and personal experience. The unprecedented increase in the amount, variety and the value of data has been significantly transforming the way that scientific research is carried out and businesses operate. Within data science, which has emerged as a practice to enable this data-intensive innovation by gathering together and advancing the knowledge from fields such as statistics, machine learning, knowledge extraction, data management, and visualization, visualization plays a unique and maybe the ultimate role as an approach to facilitate the human and computer cooperation, and to particularly enable the analysis of diverse and heterogeneous data using complex computational methods where algorithmic results are challenging to interpret and operationalize. Whilst algorithm development is surely at the center of the whole pipeline in disciplines such as Machine Learning and Knowledge Discovery, it is visualization which ultimately makes the results accessible to the end user. Visualization thus can be seen as a mapping from arbitrarily high-dimensional abstract spaces to the lower dimensions and plays a central and critical role in interacting with machine learning algorithms, and particularly in interactive machine learning (iML) with including the human-in-the-loop. The central goal of the CD-MAKE VIS workshop is to spark discussions at this intersection of visualization, machine learning and knowledge discovery and bring together experts from these disciplines. This paper discusses a perspective on the challenges and opportunities in this integration of these discipline and presents a number of directions and strategies for further research

Observations of oxidation products above a forest imply biogenic emissions of very reactive compounds

International audienceMeasurements of volatile organic compounds in a pine forest (Central California, 38.90° N, 120.63° W, 1315 m) reveal large quantities of previously unreported oxidation products of short lived biogenic precursors. The emission of biogenic precursors must be in the range of 13?66 µmol m?2 h?1 to produce the observed oxidation products. That is 6?30 times the emissions of total monoterpenes observed above the forest canopy on a molar basis. These reactive precursors constitute the largest fraction of biogenic emissions at this site, and are not included in current emission inventories. When oxidized by ozone they should efficiently produce secondary aerosol and hydroxyl radicals