Bio-inspired band-gap tunable elastic optical multilayer fibers.

The concentrically-layered photonic structure found in the tropical fruit Margaritaria nobilis serves as inspiration for photonic fibers with mechanically tunable band-gap. The fibers show the spectral filtering capabilities of a planar Bragg stack while the microscopic curvature decreases the strong directional chromaticity associated with flat multilayers. Elongation of the elastic fibers results in a shift of the reflection of over 200 nm.Financial support from the US Air Force Offi ce of Scientifi c Research Multidisciplinary University Research Initiative under award numbers FA9550-09-1-0669-DOD35CAP, FA9550-10-1-0020 and the UK Engineering and Physical Sciences Research Council EP/G060649/1 is gratefully acknowledged. M.Ko. acknowledges the fi nancial support from the Alexander von Humboldt Foundation in form of a Feodor Lynen postdoctoral research fellowship. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network (NNIN), which is supported by the National Science Foundation under NSF award no. ECS-0335765. CNS is part of Harvard University

Tearing down walls: opening the border between hospital and ambulatory care for quality improvement in Germany

The hospital benchmarking system in Germany was originally introduced to detect unintended consequences of reimbursement based on diagnosis-related groups. The new nationwide SQG programme aims to provide information on quality and outcomes of health care provided in hospital, ambulatory specialist and primary care settings, including the healthcare delivery across different sectors. In 2010 the topics for indicator development were cataract surgery, cervical conization, colectoral cancer and percutaneous coronary interventions or coronary angiography. A systematic stepwise modified RAND/UCLA procedure is applied to develop quality indicators in each of these domains. A general framework for data collection is implemented. Benchmarking results are fed back to providers on a regular basis

Structural colour from helicoidal cell-wall architecture in fruits of Margaritaria nobilis

The bright and intense blue-green coloration of the fruits of Margaritaria nobilis (Phyllanthaceae) was investigated using polarization-resolved spectroscopy and transmission electron microscopy. Optical measurements of freshly collected fruits revealed a strong circularly polarized reflection of the fruit that originates from a cellulose helicoidal cell wall structure in the pericarp cells. Hyperspectral microscopy was used to capture the iridescent effect at the single-cell level.This work was supported by the Leverhulme Trust (F/09- 741/G) and a BBSRC David Phillips fellowship (BB/K014617/1). P.V. acknowledges support from the US Air Force Office of Scientific Research under award number FA9550-10-1-0020. U.S. acknowledges support from the Adolphe Merkle foundation and the Swiss National Science Foundation through the National Centre of Competence in Research Bio-Inspired Materials

AER Building Blocks for Multi-Layer Multi-Chip Neuromorphic Vision Systems

A 5-layer neuromorphic vision processor whose components communicate spike events asychronously using the address-eventrepresentation (AER) is demonstrated. The system includes a retina chip, two convolution chips, a 2D winner-take-all chip, a delay line chip, a learning classifier chip, and a set of PCBs for computer interfacing and address space remappings. The components use a mixture of analog and digital computation and will learn to classify trajectories of a moving object. A complete experimental setup and measurements results are shown.Unión Europea IST-2001-34124 (CAVIAR)Ministerio de Ciencia y Tecnología TIC-2003-08164-C0

Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

International audienceAs part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia ? Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign, we studied the emission of carbon monoxide (CO), carbon dioxide (CO2), and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN) relative to CO (ERCN/CO) fell in the range 14?32 cm-3 ppb-1 for most of the time, in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependant on the fire condition (combustion efficiency). Variability in the ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2), which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, indicating that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF) for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC) fraction of emissions that are not sampled by the aircraft. The correction, previously unpublished for tropical deforestation fires, suggested an EF about one and a half to twice as large for these species. Vertical transport of biomass-burning plumes from the boundary layer (BL) to the cloud detrainment layer (CDL) and the free troposphere (FT) was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non-precipitating clouds. The detrained aerosol particles released in the CDL and FT were larger due to coagulation and secondary growth, and therefore more efficient at scattering radiation and nucleating cloud droplets than the fresh particles. This process may have significant atmospheric implications on a regional and larger scale

[Pd(2‐pymo)₂]n/Al₂O₃ as MOF Single Site Catalyst for the Selective Hydrogenation of Acetylene

Despite the great potential of metal-organic frameworks (MOFs) in catalysis, industrial applications are still scarce. This is mainly due to a lack of performance when changing from idealized lab conditions towards realistic conditions of the actual application. In this work, we demonstrate the applicability and outstanding catalytic performance of an alumina-supported [Pd(2-pymo)₂]n MOF catalyst in the selective hydrogenation of acetylene to ethylene under industrial front-end conditions. It shows a competitive performance to an industrial benchmark catalyst and even exceeds it in terms of ethane selectivity due to the combination of well-defined isolated Pd active sites and synergies due to MOF-support-interactions. The high stability was proven for up to 60 h time-on-stream and supported by XPS and XRD structural analysis

RNA-MATE: a recursive mapping strategy for high-throughput RNA-sequencing data

Summary: Mapping of next-generation sequencing data derived from RNA samples (RNAseq) presents different genome mapping challenges than data derived from DNA. For example, tags that cross exon-junction boundaries will often not map to a reference genome, and the strand specificity of the data needs to be retained. Here we present RNA-MATE, a computational pipeline based on a recursive mapping strategy for placing strand specific RNAseq data onto a reference genome. Maximizing the mappable tags can provide significant savings in the cost of sequencing experiments. This pipeline provides an automatic and integrated way to align color-space sequencing data, collate this information and generate files for examining gene-expression data in a genomic context

Tunable anisotropy in inverse opals and emerging optical properties

Using self-assembly, nanoscale materials can be fabricated from the bottom up. Opals and inverse opals are examples of self-assembled nanomaterials made from crystallizing colloidal particles. As self-assembly requires a high level of control, it is challenging to use building blocks with anisotropic geometry to form complex opals, which limits the realizable structures. Typically, spherical colloids are employed as building blocks, leading to symmetric, isotropic superstructures. However, a significantly richer palette of directionally dependent properties are expected if less symmetric, anisotropic structures can be created, especially originating from the assembly of regular, spherical particles. Here we show a simple method to introduce anisotropy into inverse opals by subjecting them to a post-assembly thermal treatment that results in directional shrinkage of the silica matrix caused by condensation of partially hydrated sol-gel silica structures. In this way, we can tailor the shape of the pores, and the anisotropy of the final inverse opal preserves the order and uniformity of the self-assembled structure, while completely avoiding the need to synthesize complex oval-shaped particles and crystallize them into such target geometries. Detailed X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy studies clearly identify increasing degrees of sol-gel condensation in confinement as a mechanism for the structure change. A computer simulation of structure changes resulting from the condensation-induced shrinkage further confirmed this mechanism. As an example of property changes induced by the introduction of anisotropy, we characterized the optical spectra of the anisotropic inverse opals and found that the optical properties can be controlled in a precise way using calcination temperature

An airborne regional carbon balance for central amazonia

We obtained regional estimates of surface CO2 exchange rates using atmospheric boundary layer budgeting techniques above tropical forest near Manaus, Brazil. Comparisons were made with simultaneous measurements from two eddy covariance towers below. Although there was good agreement for daytime measurements, large differences emerged for integrating periods dominated by the night-time fluxes. These results suggest that a systematic underestimation of night time respiratory effluxes may be responsible for the high Amazonian carbon sink suggested by several previous eddy covariance studies. Large CO2 fluxes from riverine sources or high respiratory losses from recently disturbed forests do not need to be invoked in order to balance the carbon budget of the Amazon. Our results do not, however, discount some contribution of these processes to the overall Amazon carbon budget