A Global Human Settlement Layer from optical high resolution imagery - Concept and first results

A general framework for processing of high and very-high resolution imagery for creating a Global Human Settlement Layer (GHSL) is presented together with a discussion on the results of the first operational test of the production workflow. The test involved the mapping of 24.3 millions of square kilometres of the Earth surface spread over four continents, corresponding to an estimated population of 1.3 billion of people in 2010. The resolution of the input image data ranges from 0.5 to 10 meters, collected by a heterogeneous set of platforms including satellite SPOT (2 and 5), CBERS-2B, RapidEye (2 and 4), WorldView (1 and 2), GeoEye-1, QuickBird-2, Ikonos-2, and airborne sensors. Several imaging modes were tested including panchromatic, multispectral and pan-sharpened images. A new fully automatic image information extraction, generalization and mosaic workflow is presented that is based on multiscale textural and morphological image features extraction. New image feature compression and optimization are introduced, together with new learning and classification techniques allowing for the processing of HR/VHR image data using low-resolution thematic layers as reference. A new systematic approach for quality control and validation allowing global spatial and thematic consistency checking is proposed and applied. The quality of the results are discussed by sensor, by band, by resolution, and eco-regions. Critical points, lessons learned and next steps are highlighted.JRC.G.2-Global security and crisis managemen

Sterol biosensor reveals LAM-family Ltc1-dependent sterol flow to endosomes upon Arp2/3 inhibition.

Sterols are crucial components of biological membranes, which are synthetized in the ER and accumulate in the plasma membrane (PM). Here, by applying a genetically encoded sterol biosensor (D4H), we visualize a sterol flow between PM and endosomes in the fission yeast Schizosaccharomyces pombe. Using time-lapse and correlative light-electron microscopy, we found that inhibition of Arp2/3-dependent F-actin assembly promotes the reversible relocalization of D4H from the PM to internal sterol-rich compartments (STRIC) labeled by synaptobrevin Syb1. Retrograde sterol internalization to STRIC is independent of endocytosis or an intact Golgi, but depends on Ltc1, a LAM/StARkin-family protein localized to ER-PM contact sites. The PM in ltc1Δ cells over-accumulates sterols and upon Arp2/3 inhibition forms extended ER-interacting invaginations, indicating that sterol transfer contributes to PM size homeostasis. Anterograde sterol movement from STRIC is independent of canonical vesicular trafficking but requires Arp2/3, suggesting a novel role for this complex. Thus, transfer routes orthogonal to vesicular trafficking govern the flow of sterols in the cell

Improved Reliability of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control

The objective of stormwater detention basins is to capture stormwater runoff to reduce and delay peak flow and to improve the water quality. These objectives can be improved upon by actively controlling the outflow of the basins rather than traditional passive outflow structures. There are studies demonstrating the performance of the active controls that respond in real-time to basin hydraulics, detention time, and rainfall forecasts. We hypothesize that the performance of these active controls can be improved upon by incorporating real-time water quality data streams into the control algorithm. Furthermore, we hypothesize that performance of these active controls also depends on hydrologic variability, perturbing the highly dynamic rainfall-runoff process. Here, these hypotheses are tested using a numerical modeling framework evaluating the systems-level reliability of passive and active control of stormwater basin outflow using a Monte Carlo method. The numerical modeling is performed in EPA-SWMM urban hydrologic model driven by stochastic rainfall time-series generated from the Modified Bartlett-Lewis Rectangular Pulses Model. Water quality-informed real-time active control algorithms are developed, tested, and demonstrated to result in a clear improvement over the traditional passive (no control) systems and other storage-based active controls for water and suspended sediment capture. Duration curve analysis showed that both water level- and water quality- informed control performance varied for different storm return periods and this variability could partly be attributed to the fraction of time the valve is closed. In addition, control performance was sensitive to rainfall variability, generally decreasing as storms become less frequent and more intense. Therefore, control system performance may depend on seasonal and longer time-scale variability in climate and rainfall-runoff processes. We anticipate this study to be a starting point to incorporate theories of reliability to assess detention basin and conveyance network performance under more complex real-time control algorithms and failure modes

Navigating the roadblocks to spectral color reproduction: data-efficient multi-channel imaging and spectral color management

Commercialization of spectral imaging for color reproduction will require the identification and traversal of roadblocks to its success. Among the drawbacks associated with spectral reproduction is a tremendous increase in data capture bandwidth and processing throughput. Methods are proposed for attenuating these increases with data-efficient methods based on adaptive multi-channel visible-spectrum capture and with low-dimensional approaches to spectral color management. First, concepts of adaptive spectral capture are explored. Current spectral imaging approaches require tens of camera channels although previous research has shown that five to nine channels can be sufficient for scenes limited to pre-characterized spectra. New camera systems are proposed and evaluated that incorporate adaptive features reducing capture demands to a similar few channels with the advantage that a priori information about expected scenes is not needed at the time of system design. Second, proposals are made to address problems arising from the significant increase in dimensionality within the image processing stage of a spectral image workflow. An Interim Connection Space (ICS) is proposed as a reduced dimensionality bottleneck in the processing workflow allowing support of spectral color management. In combination these investigations into data-efficient approaches improve two critical points in the spectral reproduction workflow: capture and processing. The progress reported here should help the color reproduction community appreciate that the route to data-efficient multi-channel visible spectrum imaging is passable and can be considered for many imaging modalities

NOVEL TECHNIQUES FOR IN VIVO CHARACTERIZATION OF SHORT PEPTIDES AND PROTEINS IN MEMBRANE PERMEABILIZATION AND SIGNAL TRANSDUCTION

My scientific interest is focused on the field of cellular electrical activity, ranging from the study of intracellular enzymatic processes to the characterization of new generation of drugs. For this purpose I also used the most powerful techniques of investigation, including patch-clamp technique, fluorescence imaging, and surface plasmon resonance (SPR) spectroscopy. Moreover, to shed light on complex molecular mechanisms, unconventional strategies were employed, requiring sometimes the realization of specific devices not commercially available. In particular my PhD thesis includes two different scientific projects: the biophysical characterization of antimicrobial peptides and the modulation of visual phototransduction in vertebrate cones. In the first project, the patch-clamp technique was employed to study the pore forming properties of synthetic cecropin-melittin hybrid peptide (CM15), alamethicin F50/5 and its synthetic analog [L-Glu(OMe)7,18,19] under strict physiological conditions. These short peptides selectively permeabilize the bacteria plasma membrane leading to their lyses and death: they are therefore a source of antibacterial molecules, and inspiration for novel and more selective drugs. I pursued this study by recording the ion current through the channels formed by these peptides, once inserted in the membrane of photoreceptor rod outer segment membrane (OS) isolated from frog retinae. The peptides were applied to (and removed from) the extracellular OS side in ~50 ms with a computer-controlled microperfusion system, so that the ion channel characteristics (as its selectivity, blockade and gating) and the dynamics of pore formation could be precisely assessed. On the basis of the electrophysiological recordings obtained, it was demonstrated that, different than alamethicins, CM15 produced voltage-independent membrane permeabilisation, repetitive peptide application caused a progressive permeabilisation increase, and no single-channel events were detected at low peptide concentrations. Collectively, these results indicate that CM15 form pores according to a toroidal model. Moreover, in order to understand the divalent-cation dependency of [L-Glu(OMe)7,18,19] binding to the lipid bilayer at the molecular level, the electrophysiological experiments were paralleled with experiments employing SPR spectroscopy. Results indicate the presence of Ca2+ in the external solution increases the probability of formation of smaller and more stable [L-Glu(OMe)7,18,19] pores. The second project of this thesis concerns the investigation of the physiological role of the neuronal calcium sensor zGCAP3 in the photrasduction cascade. This study was pursued through the simulation of an over expression and a knock-down of this protein, by delivering it, or its monoclonal antibody, into zebrafish cone cytosol, while recording their photoresponses with the patch-clamp technique. The intracellular protein delivery was attained via the patch pipette, by ejecting the proteins out of a tube inserted into the pipette lumen. A microperfusion system was employed to apply the desired exogenous molecules with a precise timing. However, the long tapered shape of the pipette shank make it very difficult to perfuse efficiently the cell with this strategy. For this reason a pressure polishing setup was assembled to enlarge the patch pipette shank, through the calibrated combination of heat and air pressure. This allowed to insert quartz or plastic tubes in the pipette lumen very close to its tip. In order to obtain a substantial and specific silencing of the zGCAP3s in zebrafish cones, surface plasmon resonance experiments were performed to allow the selection of a monoclonal antibody with strong affinity for zGCAP3 and low cross interaction with other components of the phototransduction cascade. Results showed that the perfusion with GCAP3 did not altered significantly the light response, while he anti-zGCAP3 incorporation in the cytosol caused the progressive photoresponse fall, followed by the progressive fall of saturating flash response amplitude, probably due to the progressive GC inhibition. The unexpected lack of an effect of zGCAP3 incorporation in the cone cytosol, suggests that the endogenous number of zGCAP3 is saturating, i.e. their number is equal or above the number of their target molecules (guanylate cyclase), therefore any further increase of zGAP3 in the cytosol is uneffective