Aerosol remote sensing from ground-based polarized sky-radiance under cloudy conditions

Für ein besseres Verständnis der Wechselwirkungsprozesse zwischen Aerosolen und Wolken ist es nötig diese in der Umgebung von Wolken zu untersuchen. Polarisationsaufgelöste Messungen haben sich als adäquate Erweiterung klassischer, multispektraler Photometrie bewährt, da sie zusätzliche Information über die Teilen enthalten. In dieser Arbeit wurde ein neuer Algorithmus entwickelt, um mikrophysikalische und optische Aerosoleigenschaften aus bodengebundenen, polarisations- und wellenlängenaufgelösten Messungen der Himmelshelligkeit abzuleiten. Dieser beinhaltet eine Technik zum detektieren und entfernen bewölkter Messpunkte, wodurch die Methode bei teilweiser Bewölkung anwendbar ist. Es wurden numerische Studien mit synthetischen Beobachtungen durchgeführt, die mit 3D Monte-Carlo Strahlungstransportrechnungen erzeugt wurden und unterschiedliche Wolkensituation enthalten, wie Straßen aus Quaderwolken oder realistischere Wolkenfelder aus Large-Eddy-Simulationen (LES). Diese werden zunächst verwendet, um Veränderungen der gemessenen polarisationsaufgelösten Strahldichte zu bestimmen, die durch von Wolken induzierte 3D-Stahlungseffekte entstehen. Die unpolarisierte Strahldichte wird in unmittelbarer Nähe zu Wolken bei 550 nm um bis zu 55% erhöht. In der selben Situation wird die polarisierte Strahldichte verringert, jedoch nur um ungefähr 25%. Als nächstes wurde der Einfluss dieser veränderten Messungen auf die aus ihnen abgeleiteten Aerosoleigenschaften untersucht. In den meisten Fällen konnten Effektivradius und optische Dicke zuverlässig bestimmt werden, sogar wenn ein großer Teil (bis zu 70%) des Himmels mit Wolken bedeckt war. Die optische Dicke des Aerosol wird in der Regel leicht überschätzt, jedoch um nicht mehr als 0,03 oder 10%. Der abgeleitete Effektivradius der Feinpartikel stimmt auf 0,04 µm genau, unabhängig vom Grad der Bewölkung. Für den Effektivradius der Grobpartikel wird der Fehler hin zu größeren Teilchen höher. Der Realteil des Brechungsindex wird in den meisten Fällen überschätzt. Im zweiten Teil wurde der Algorithmus auf Messungen des multispektralen Sonnenphotometers SSARA angewendet. Dieses wurde bereits mit Polarisationsfiltern ausgestattet, um bei 501,5 nm die polarisierte Strahldichte messen zu können. Während der A-LIFE Messkampagne, die im April 2017 in Zypern stattfand, sammelte SSARA an 22 Tagen Messdaten. Hier werden drei Fallstudien gezeigt: Die erste veranschaulicht das Verhalten des Algorithmus bei teilweiser Bewölkung. Im zweiten Fall herrschte aufgrund einer Saharastaubschicht eine hohe Aerosolbelastung bei ansonsten klarem Himmel. Der dritte Fall beschreibt das Aufziehen von Feinpartikel-Aerosolen aus Waldbrandgebieten. Während der Vorbereitung des Instruments wurde zudem eine neuartige radiometrische und polarimetrische Kalibriermethode entwickelt, die es erlaubt gleichzeitig die Güte und die Winkel der Polarisationsfilter mit hoher Genauigkeit zu bestimmen (entsprechend auf 0,002 und unter 0,1°). Des weiteren wurde eine neue Methode für die Kalibrierung unserer altazimuthalen Montierung verwendet, die eine Korrektur der Positionierung des Messkopfs auf unter 32 arcmin ermöglicht. Dies ist momentan durch die Genauigkeit des verwendeten Sonnensuchers beschränkt. Diese beiden Kalibriermethoden sind auch auf andere Sonnenphotometer anwendbar, wie zum Beispiel die Cimel CE318-DP Instrumente, die in AERONET verwendet werden.To study aerosol-cloud interactions, observations in the vicinity of clouds are necessary. Polarimetry has proven to be a useful enhancement to classical multispectral photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. In this thesis, a new retrieval algorithm for the retrieval of microphysical and optical aerosol properties from ground-based polarized and multispectral sky radiance measurements was developed. It includes a cloud screening mechanism that makes the method applicable to partly cloudy situations. Numerical studies have been conduced with synthetic observations generated using 3D Monte-Carlo radiative transfer simulations of different cloud situations, including cuboid cloud streets and more realistic Large-Eddy simulation (LES) generated cloud fields. These are used to first determine the 3D radiative cloud effects observable in the measured polarized radiances as a function of cloud distance. Total radiance is increased by up to 55% on average close to clouds at 550 nm, while linear polarized radiance is reduced, but only by about 25% in the same case. The influence of these altered measurements on the aerosol properties retrieved from them was investigated next. For most cases, effective radius and optical depth of the aerosol can be retrieved well, even if a significant portion (up to 70%) of the sky is covered by clouds. The aerosol optical depth is typically slightly overestimated (not more than 0.03 or 10%). The retrieval of fine mode particle effective radius is accurate to within 0.04 µm regardless of the cloud contamination. For the retrieved coarse mode effective radius the error becomes larger towards bigger particles. A positive bias in the retrieved index of refraction has been observed in most cases. In a second step, the retrieval was applied to measurements made with the SSARA multispectral sun and sky photometer, which has previously been equipped with polarizer filters to measure polarized radiance at 501.5 nm. During the A-LIFE field campaign in Cyprus in April 2017, SSARA collected 22 days of data. Here, three case studies are presented: The first demonstrates the performance of the retrieval under partially cloudy conditions. In the second case, a high aerosol load due to a Saharan dust layer was present during otherwise perfect clear sky conditions. Fine mode dominated Biomass burning aerosol was observed in the third case. During the preparation of the instrument, a novel radiometric and polarimetric calibration method has been developed, which simultaneously determines the linear polarizers' diattenuation and relative orientation with high accuracy (0.002 and below 0.1°, respectively). Furthermore, a new calibration method for the alt-azimuthal mount capable of correcting the instrument's pointing to within 32 arcmin was implemented. So far, this is limited by the accuracy of the sun-tracker. Both these methods are applicable to other sun and sky radiometers, such as Cimel CE318-DP instruments used in AERONET

Aerosol remote sensing from ground-based polarized sky-radiance under cloudy conditions

Für ein besseres Verständnis der Wechselwirkungsprozesse zwischen Aerosolen und Wolken ist es nötig diese in der Umgebung von Wolken zu untersuchen. Polarisationsaufgelöste Messungen haben sich als adäquate Erweiterung klassischer, multispektraler Photometrie bewährt, da sie zusätzliche Information über die Teilen enthalten. In dieser Arbeit wurde ein neuer Algorithmus entwickelt, um mikrophysikalische und optische Aerosoleigenschaften aus bodengebundenen, polarisations- und wellenlängenaufgelösten Messungen der Himmelshelligkeit abzuleiten. Dieser beinhaltet eine Technik zum detektieren und entfernen bewölkter Messpunkte, wodurch die Methode bei teilweiser Bewölkung anwendbar ist. Es wurden numerische Studien mit synthetischen Beobachtungen durchgeführt, die mit 3D Monte-Carlo Strahlungstransportrechnungen erzeugt wurden und unterschiedliche Wolkensituation enthalten, wie Straßen aus Quaderwolken oder realistischere Wolkenfelder aus Large-Eddy-Simulationen (LES). Diese werden zunächst verwendet, um Veränderungen der gemessenen polarisationsaufgelösten Strahldichte zu bestimmen, die durch von Wolken induzierte 3D-Stahlungseffekte entstehen. Die unpolarisierte Strahldichte wird in unmittelbarer Nähe zu Wolken bei 550 nm um bis zu 55% erhöht. In der selben Situation wird die polarisierte Strahldichte verringert, jedoch nur um ungefähr 25%. Als nächstes wurde der Einfluss dieser veränderten Messungen auf die aus ihnen abgeleiteten Aerosoleigenschaften untersucht. In den meisten Fällen konnten Effektivradius und optische Dicke zuverlässig bestimmt werden, sogar wenn ein großer Teil (bis zu 70%) des Himmels mit Wolken bedeckt war. Die optische Dicke des Aerosol wird in der Regel leicht überschätzt, jedoch um nicht mehr als 0,03 oder 10%. Der abgeleitete Effektivradius der Feinpartikel stimmt auf 0,04 µm genau, unabhängig vom Grad der Bewölkung. Für den Effektivradius der Grobpartikel wird der Fehler hin zu größeren Teilchen höher. Der Realteil des Brechungsindex wird in den meisten Fällen überschätzt. Im zweiten Teil wurde der Algorithmus auf Messungen des multispektralen Sonnenphotometers SSARA angewendet. Dieses wurde bereits mit Polarisationsfiltern ausgestattet, um bei 501,5 nm die polarisierte Strahldichte messen zu können. Während der A-LIFE Messkampagne, die im April 2017 in Zypern stattfand, sammelte SSARA an 22 Tagen Messdaten. Hier werden drei Fallstudien gezeigt: Die erste veranschaulicht das Verhalten des Algorithmus bei teilweiser Bewölkung. Im zweiten Fall herrschte aufgrund einer Saharastaubschicht eine hohe Aerosolbelastung bei ansonsten klarem Himmel. Der dritte Fall beschreibt das Aufziehen von Feinpartikel-Aerosolen aus Waldbrandgebieten. Während der Vorbereitung des Instruments wurde zudem eine neuartige radiometrische und polarimetrische Kalibriermethode entwickelt, die es erlaubt gleichzeitig die Güte und die Winkel der Polarisationsfilter mit hoher Genauigkeit zu bestimmen (entsprechend auf 0,002 und unter 0,1°). Des weiteren wurde eine neue Methode für die Kalibrierung unserer altazimuthalen Montierung verwendet, die eine Korrektur der Positionierung des Messkopfs auf unter 32 arcmin ermöglicht. Dies ist momentan durch die Genauigkeit des verwendeten Sonnensuchers beschränkt. Diese beiden Kalibriermethoden sind auch auf andere Sonnenphotometer anwendbar, wie zum Beispiel die Cimel CE318-DP Instrumente, die in AERONET verwendet werden.To study aerosol-cloud interactions, observations in the vicinity of clouds are necessary. Polarimetry has proven to be a useful enhancement to classical multispectral photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. In this thesis, a new retrieval algorithm for the retrieval of microphysical and optical aerosol properties from ground-based polarized and multispectral sky radiance measurements was developed. It includes a cloud screening mechanism that makes the method applicable to partly cloudy situations. Numerical studies have been conduced with synthetic observations generated using 3D Monte-Carlo radiative transfer simulations of different cloud situations, including cuboid cloud streets and more realistic Large-Eddy simulation (LES) generated cloud fields. These are used to first determine the 3D radiative cloud effects observable in the measured polarized radiances as a function of cloud distance. Total radiance is increased by up to 55% on average close to clouds at 550 nm, while linear polarized radiance is reduced, but only by about 25% in the same case. The influence of these altered measurements on the aerosol properties retrieved from them was investigated next. For most cases, effective radius and optical depth of the aerosol can be retrieved well, even if a significant portion (up to 70%) of the sky is covered by clouds. The aerosol optical depth is typically slightly overestimated (not more than 0.03 or 10%). The retrieval of fine mode particle effective radius is accurate to within 0.04 µm regardless of the cloud contamination. For the retrieved coarse mode effective radius the error becomes larger towards bigger particles. A positive bias in the retrieved index of refraction has been observed in most cases. In a second step, the retrieval was applied to measurements made with the SSARA multispectral sun and sky photometer, which has previously been equipped with polarizer filters to measure polarized radiance at 501.5 nm. During the A-LIFE field campaign in Cyprus in April 2017, SSARA collected 22 days of data. Here, three case studies are presented: The first demonstrates the performance of the retrieval under partially cloudy conditions. In the second case, a high aerosol load due to a Saharan dust layer was present during otherwise perfect clear sky conditions. Fine mode dominated Biomass burning aerosol was observed in the third case. During the preparation of the instrument, a novel radiometric and polarimetric calibration method has been developed, which simultaneously determines the linear polarizers' diattenuation and relative orientation with high accuracy (0.002 and below 0.1°, respectively). Furthermore, a new calibration method for the alt-azimuthal mount capable of correcting the instrument's pointing to within 32 arcmin was implemented. So far, this is limited by the accuracy of the sun-tracker. Both these methods are applicable to other sun and sky radiometers, such as Cimel CE318-DP instruments used in AERONET

Food Control by Government Laboratories: Innovation, Flexibility, and No Restrictions by Reglementation

Part of the work carried out by the government laboratories is devoted to permanent control of some critical foods and involves well-established and standardized methods. Another part, however, particularly the detection of frauds or poor manufacturing practices, presupposes advanced analytical techniques and flexible politics: an agile sense for hot subjects must be combined with good contacts providing the important information and innovative method development to find ways to obtain the evidence required. As shown for examples, ever new methods and approaches are needed, because the fraud and the negligent worker rapidly adjust to the methods applied for the control – in the end, the analysis may even protect a well arranged fraud. The swindler needs certainty about what the government chemists analyze and what methods they apply, and is, therefore, interested in paralyzing the work of the control, e.g. by requiring that only methods approved by time-consuming procedures are accepted by the court. The control must try to surprise and to create commotion, keeping everyone alert

Susceptibility testing of Atopobium vaginae for dequalinium chloride

<p>Abstract</p> <p>Background</p> <p><it>Atopobium vaginae </it>and <it>Gardnerella vaginalis </it>are major markers for bacterial vaginosis. We aimed to determine the MIC and MBC range of the broad-spectrum anti-infective and antiseptic dequalinium chloride for 28 strains, belonging to 4 species of the genus <it>Atopobium, i.e. A. vaginae, A. minutum, A. rimae </it>and <it>A. parvulum</it>.</p> <p>Methods</p> <p>The MIC was determined with a broth microdilution assay.</p> <p>Results</p> <p>The MIC and MBC for <it>Atopobium </it>spp. for dequalinium chloride ranged between < 0.0625 and 2 μg/ml.</p> <p>Conclusions</p> <p>This study demonstrated that dequalinium chloride inhibits and kills clinical isolates of <it>A. vaginae </it>at concentrations similar to those of clindamycin and lower than those of metronidazole.</p

Automatic Calculation of Cervical Spine Parameters Using Deep Learning: Development and Validation on an External Dataset

STUDY DESIGN Retrospective data analysis. OBJECTIVES This study aims to develop a deep learning model for the automatic calculation of some important spine parameters from lateral cervical radiographs. METHODS We collected two datasets from two different institutions. The first dataset of 1498 images was used to train and optimize the model to find the best hyperparameters while the second dataset of 79 images was used as an external validation set to evaluate the robustness and generalizability of our model. The performance of the model was assessed by calculating the median absolute errors between the model prediction and the ground truth for the following parameters: T1 slope, C7 slope, C2-C7 angle, C2-C6 angle, Sagittal Vertical Axis (SVA), C0-C2, Redlund-Johnell distance (RJD), the cranial tilting (CT) and the craniocervical angle (CCA). RESULTS Regarding the angles, we found median errors of 1.66° (SD 2.46°), 1.56° (1.95°), 2.46° (SD 2.55), 1.85° (SD 3.93°), 1.25° (SD 1.83°), .29° (SD .31°) and .67° (SD .77°) for T1 slope, C7 slope, C2-C7, C2-C6, C0-C2, CT, and CCA respectively. As concerns the distances, we found median errors of .55 mm (SD .47 mm) and .47 mm (.62 mm) for SVA and RJD respectively. CONCLUSIONS In this work, we developed a model that was able to accurately predict cervical spine parameters from lateral cervical radiographs. In particular, the performances on the external validation set demonstrate the robustness and the high degree of generalizability of our model on images acquired in a different institution

Combining metagenomics with metaproteomics and stable isotope probing reveals metabolic pathways used by a naturally occurring marine methylotroph

A variety of culture-independent techniques have been developed that can be used in conjunction with culture-dependent physiological and metabolic studies of key microbial organisms, in order to better understand how the activity of natural populations influences and regulates all major biogeochemical cycles. In this study, we combined DNA-stable isotope probing with metagenomics and metaproteomics to characterize an as yet uncultivated marine methylotroph that actively incorporated carbon from 13C-labeled methanol into biomass. By metagenomic sequencing of the heavy DNA, we retrieved virtually the whole genome of this bacterium and determined its metabolic potential. Through protein-stable isotope probing, the RuMP cycle was established as the main carbon assimilation pathway, and the classical methanol dehydrogenase-encoding gene mxaF, as well as three out of four identified xoxF homologues were found to be expressed. This proof-of-concept study is the first in which theculture-independent techniques of DNA- and protein-stable isotope probing have been used to characterize the metabolism of a naturally-ocurring Methylophaga-like bacterium in the marine environment (i.e. M. thiooxydans L4) and thus provides a powerful approach to access the genome and proteome of uncultivated microbes involved in key processes in the environment

Rationale and design of The Delphi Trial – I(RCT)(2): international randomized clinical trial of rheumatoid craniocervical treatment, an intervention-prognostic trial comparing 'early' surgery with conservative treatment [ISRCTN65076841]

BACKGROUND: Rheumatoid arthritis is a chronic inflammatory disease, which affects 1% of the population. Hands and feet are most commonly involved followed by the cervical spine. The spinal column consists of vertebrae stabilized by an intricate network of ligaments. Especially in the upper cervical spine, rheumatoid arthritis can cause degeneration of these ligaments, causing laxity, instability and subluxation of the vertebral bodies. Subsequent compression of the spinal cord and medulla oblongata can cause severe neurological deficits and even sudden death. Once neurological deficits occur, progression is inevitable although the rapidity of progression is highly variable. The first signs and symptoms are pain at the back of the head caused by compression of the major occipital nerve, followed by loss of strength of arms and legs. The severity of the subluxation can be observed with radiological investigations (MRI, CT) with a high sensitivity. The authors have sent a Delphi Questionnaire about the current treatment strategies of craniocervical involvement by rheumatoid arthritis to an international forum of expert rheumatologists and surgeons. The timing of surgery in patients with radiographic instability without evidence of neurological deficit is an area of considerable controversy. If signs and symptoms of myelopathy are present there is little chance of recovery to normal levels after surgery. DESIGN: In this international multicenter randomized clinical trial, early surgical atlantoaxial fixation in patients with rheumatoid arthritis and radiological abnormalities without neurological deficits will be compared with prolonged conservative treatment. The main research question is whether early surgery can prevent radiological and neurological progression. A cost-effectivity analysis will be performed. 250 patients are needed to answer the research question. DISCUSSION: Early surgery could prevent serious neurological deficits, but may have peri-operative morbidity and loss of rotation of the head and neck. The objective of this study is to identify the best timing of surgery for patients at risk for the development of neurological signs and symptoms

Patient preferences in the medical product lifecycle

Taking into consideration the patient voice has not only become increasingly important for the companies that develop new medical products, but also for the authorities that assess, regulate and decide which medical products are effective, safe, well tolerated and cost-effective. Patient preference studies can complement patient narratives and qualitative insights in a quantitative manner and provide understanding of the trade-offs patients are willing to make. However, what is currently missing is a shared understanding among key stakeholders (industry, regulatory authorities, health technology assessment bodies, reimbursement agencies, clinicians and patient organisations) about when and how to consider patient preferences in the medical product lifecycle. This commentary captures important opinions on patient preferences and the medical product lifecycle that were discussed in the rare opportunity to gather key opinion leaders from a wide range of perspectives that was offered by the symposium on “Patient preferences in the medical product lifecycle” held in Basel, Switzerland in July 2019. The symposium was jointly organised by the International Academy of Health Preference Research (IAHPR) and the Innovative Medicine Initiative research project ‘Patient Preferences in Benefit and Risk Assessments during the Treatment Life Cycle’ (PREFER)

The North Atlantic Waveguide and Downstream Impact Experiment

The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) explored the impact of diabatic processes on disturbances of the jet stream and their influence on downstream high-impact weather through the deployment of four research aircraft, each with a sophisticated set of remote sensing and in situ instruments, and coordinated with a suite of ground-based measurements. A total of 49 research flights were performed, including, for the first time, coordinated flights of the four aircraft: the German High Altitude and Long Range Research Aircraft (HALO), the Deutsches Zentrum für Luft- und Raumfahrt (DLR) Dassault Falcon 20, the French Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) Falcon 20, and the British Facility for Airborne Atmospheric Measurements (FAAM) BAe 146. The observation period from 17 September to 22 October 2016 with frequently occurring extratropical and tropical cyclones was ideal for investigating midlatitude weather over the North Atlantic. NAWDEX featured three sequences of upstream triggers of waveguide disturbances, as well as their dynamic interaction with the jet stream, subsequent development, and eventual downstream weather impact on Europe. Examples are presented to highlight the wealth of phenomena that were sampled, the comprehensive coverage, and the multifaceted nature of the measurements. This unique dataset forms the basis for future case studies and detailed evaluations of weather and climate predictions to improve our understanding of diabatic influences on Rossby waves and the downstream impacts of weather systems affecting Europe

Determination of steady-state mRNA levels of individual chlorophyll a/b binding protein genes of the tomato cab gene family

The steady-state levels of mRNA produced by 14 genes encoding members of the tomtato chlorophyll a/b binding protein family were quantified. All genes were found to be expressed in leaf tissue, but the mRNAs accumulated to significantly different levels. The transcripts of cab 1A, cab 1B, cab 3A and cab 3B, encoding the Type I LHC proteins of photosystem II, are abundant, while low levels were measured for mRNAs encoding the Type II LHC II and the LHC I proteins. Sequences from the 5′ upstream regions (−400 to translational start) of some cab genes were determined in this study, and a total of 16 tomato cab gene promoters for which sequences are now available were analyzed. Significant sequence conservation was found for those genes which are tandemly linked on the chromosome. However, the level of sequence conservation is different for the different cab subfamilies, e.g. 85% similarity between cab 1A and cab 1D vs. 45% sequence similarity between cab 3A and cab 3C upstream sequences. Characteristic GATA repeats with a conserved spacing were found in 5′ upstream sequences of cab 1AD, cab 3 A-C, cab 11 and cab 12. The consensus sequence CCTTATCAT, which is believed to mediate light responsiveness, was found at different locations in the upstream sequences of cab 6B, cab 7, cab 8, cab 9, cab 10A, cab 10B and cab 11. In 11 out of 15 genes the transcription initiation site was found to center on the triplet TCA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47581/1/438_2004_Article_BF00280298.pd