Short-term Variation in Measurements of Atmospheric Ice-Nucleating Particle Concentrations

Primary ice formation in clouds is initiated by a minor subset of the total atmospheric aerosol population called ice-nucleating particles (INPs), that originate from various source regions around the globe. Tropospheric clouds containing ice crystals are a key player for facilitating life on Earth by providing fresh water originating from liquid and solid precipitation and by balancing the radiation budget with their optical properties. The number concentration of atmospheric INPs and the related number of ice crystals is highly variable and strongly depends on the aerosol type and properties. Due to changes in the ambient conditions or physical or chemical processes in the atmosphere on a time scale of minutes to a few hours, the INP concentration may vary on a similar time scale. Especially the potential short-term variation is still not well investigated and underrepresented in models, but may be addressed with automated INP measurements with a high time resolution at well controlled conditions. A major subject of the here presented thesis is to quantify the short-term variation of atmospheric INP concentrations and search for possible causes for this variation by correlating the INP measurements with other variables like the aerosol number and surface area concentration and meteorological variables. The atmospheric INP measurements were performed with the newly developed cloud expansion chamber PINE (Portable Ice Nucleation Experiment), which is a mobile INP instrument optimized for automated and continuous INP measurements with a time resolution of about 6 min. In this work, PINE was operated at temperatures in the mixed-phase cloud regime between -15 °C and -30 °C. For an extension of the covered temperature range of the INP measurements to temperatures up to about -5 °C, INSEKT (Ice Nucleation Spectrometer of the Karlsruhe Institute of Technology) analysis were performed. INSEKT is a well established method and was also used to validate the PINE measurements, but has the drawback of a poor time resolution of several hours or days. Because PINE is a newly developed instrument, intercomparison and validation experiments with other INP instruments were performed at the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud simulation chamber. Intercomparsion experiments with 12 different INP instruments were carried out using 5 aerosol samples with different freezing properties in the mixed-phase cloud regime. Ambient INP concentrations are highly variable, so the study in this work included for the first time an intercomparison for a wide range of INP concentrations using the same aerosol sample. Independent of the probed INP concentration, the offset between different instruments was up to 4 orders of magnitude, similar to instrument offsets reported in Hiranuma et al. (2015) and DeMott et al. (2018). The reasons for these offsets remain unclear, but may be related to different ice formation modes or pathways the different instruments are sensitive for. Ambient INP measurements at three rural locations and one mountain site were conducted continuously over a time period between 8 weeks and 5 months. Three of the campaigns included INP monitoring with PINE with a time resolution of about 6 min, and for all campaigns INSEKT INP measurements were performed with a time resolution between 4 h and 3 days. Generally, the INP concentration at all sampling sites varied between about 0.1 L^-1 and 300 L^-1 at a temperature of about -23 °C. The observed variation in the INP concentration measured with PINE in two rural environments showed enhanced positive correlations with the ambient air temperature, global radiation and planetary boundary layer height, and negative correlations with the humidity in time periods of a diurnal variation. In time periods without a diurnal variation of the INP concentration, no clear correlation with the analyzed variables was found. From this, one may conclude that the short-term variation of the INP concentration is caused by local effects, like farming activities or biological particles, which were not quantified by the measured parameters. Based on the measurements in the rural locations, a new parameterization was developed for calculating the INP concentration in models. The improved parameterization represents up to 30% more data points within a factor of 10 from the 1:1 line than previous parameterizations applied on the data set. Some existing parameterizations relate the predicted INP concentration to the number concentration of particles with a diameter larger than 0:5 μm. Also the INAS (Ice Nucleation Active Site) density approach implies that larger aerosol particles are more likely to induce ice formation. However, the impact of the size of an aerosol particle on its ice-nucleation activity is not yet well investigated. Laboratory experiments from this work with size-selected dust aerosol depicted that in some cases the freezing probability per particle surface area is independent of the size while in other cases smaller aerosol particles showed a higher freezing activity per surface area. This variable agreement was found to be potentially related to heat sensitive particles like organics or microbes, which may be more frequent at smaller particle sizes. Moreover, when conducting size-selective INP measurements in a rural environment it was observed that within a time period of about 36 h the freezing ability of the ambient aerosol changed from a size independent freezing to a higher freezing ability of larger aerosol particles. This change in the freezing ability was connected to a change in the air mass origin, which may have caused a change in the size-dependent aerosol composition. Therefore, future size-selective INP measurements at a high time resolution should be combined with size-resolved aerosol composition analysis at a similar time resolution. Inspired by the reliable and precise operation of PINE, the new stationary and small cloud expansion chamber AIDAm (AIDAmini) was developed. AIDAm is located in the cold room of the AIDA facility and samples aerosol from the AIDA chamber for e.g. measuring steady changes in the ice nucleation properties of aerosol particles which may undergo chemical aging or other modifications during long-term aerosol simulation experiments. The validation of AIDAm showed a good agreement of AIDAm, AIDA and INSEKT measurements for selected operation conditions. It was also proofed that AIDAm is able to distinguish between homogeneous freezing of aqueous aerosol particles at temperatures lower than -35 °C and the heterogeneous ice formation in the presence of INPs at the same temperature. With this new instrument, the temporal evolution of the ice nucleation ability of different aerosol samples during an hour-long coating procedure at conditions of the upper troposphere was investigated. Thereby, a 20 nm thick coating layer of sulfuric acid or secondary organic aerosol was established over 5 h, which fully suppressed or clearly shifted the ice activity of the pristine aerosol, respectively. This thesis shows the high value of automated and continuous INP measurements with a high time resolution both in the laboratory and the field and quantifies changing ice nucleation properties of aerosol particles, which may be connected to variations of environmental or meteorological processes occurring on a range of time scales from minutes to days

Greenwashing in Islamic Finance? An Analysis of Islamic Private Banks\u27 Non-Financial Reports and a Proposal for an Islamic Finance Reporting Initiative Standard

Since the beginning of the financial crisis in 2008, Islamic finance has been subject to a number of intriguing debates. While evidence suggests that Islamic private banks got through the imponderabilities of the financial crisis more easily than conventional banks, Islamic finance has been criticized by some as incapable of performing the functions of modern banking. Moreover, there has been a debate among academics as well as among practitioners whether Islamic finance indeed represents a new faith-based form of banking or whether it represents just a conventional way of banking that is based on the use of religious terminology. Against this background, we examine to what extend the disclosed information of Islamic private banks meet the constitutive criteria of the Islamic normative foundations. Based on literature of Islamic thought we derived a coding scheme with 21 items and selected a sample of 18 Islamic private banks. We analyzed the content of the selected banks’ annual reports and benchmarked the disclosure performance against Islam-based requirements. The results show that, concerning the disclosed content, few banks fully adhere to the normative standards of Islamic thought on economics as described in theoretical books on Islamic finance. Addressing this gap between theory and practice, we discuss the possibility of what we suggest to call ‘greenwashing in Islamic finance’ as an ethical challenge. Elaborating on this, we discuss the prospect of introducing more transparent disclosure standards such as an Islamic Finance Reporting Initiative inspired by the key performance indicators system of the Global Reporting Initiative (GRI) for non-financial reporting

Greenwashing in Islamic Finance? An Analysis of Islamic Private Banks\u27 Non-Financial Reports and a Proposal for an Islamic Finance Reporting Initiative Standard

Since the beginning of the financial crisis in 2008, Islamic finance has been subject to a number of intriguing debates. While evidence suggests that Islamic private banks got through the imponderabilities of the financial crisis more easily than conventional banks, Islamic finance has been criticized by some as incapable of performing the functions of modern banking. Moreover, there has been a debate among academics as well as among practitioners whether Islamic finance indeed represents a new faith-based form of banking or whether it represents just a conventional way of banking that is based on the use of religious terminology. Against this background, we examine to what extend the disclosed information of Islamic private banks meet the constitutive criteria of the Islamic normative foundations. Based on literature of Islamic thought we derived a coding scheme with 21 items and selected a sample of 18 Islamic private banks. We analyzed the content of the selected banks’ annual reports and benchmarked the disclosure performance against Islam-based requirements. The results show that, concerning the disclosed content, few banks fully adhere to the normative standards of Islamic thought on economics as described in theoretical books on Islamic finance. Addressing this gap between theory and practice, we discuss the possibility of what we suggest to call ‘greenwashing in Islamic finance’ as an ethical challenge. Elaborating on this, we discuss the prospect of introducing more transparent disclosure standards such as an Islamic Finance Reporting Initiative inspired by the key performance indicators system of the Global Reporting Initiative (GRI) for non-financial reporting

Herstellung und Modifikation bispezifischer Antikörper gegen humanes Immunglobulin E

Vor mehr als 50 Jahren, im Februar 1968, wurde der Name der fünften und letzten humanen Antikörperklasse IgE offiziell festgelegt, nachdem mehrere Wissenschaftler zuvor beobachteten, dass diese Antikörperklasse die Sensitivität gegenüber Allergenen übertragen [63]. Hatte IgE in der Vergangenheit eine Funktion als erste Verteidigungslinie gegen fremde Pathogene wie Parasiten, so tritt es in der heutigen Zeit häufiger im Zusammenhang mit allergischen Erkrankungen auf. Der Fokus der aktuell angewandten Behandlung von Allergien liegt hauptsächlich auf der Milderung der Symptome. Neue Therapieansätze, wie die beschriebene Entwicklung bispezifischer Antikörper gegen IgE-determinierte B-Zellen, wecken jedoch die Hoffnung auf eine dauerhafte Heilung. Das bispezifische BiTE®-Antikörperfomat, kurz für „Bispecific T-cell Engager“, bewirkt aufgrund seiner ersten Spezifität für CD3 auf T-Zellen und seiner zweiten Spezifität für das Zielantigen auf den zu eliminierenden Zellen die polyklonale Rekrutierung körpereigener T-Zellen und die gezielte Eliminierung der Zielzelle. Die Ergebnisse dieser Arbeit charakterisieren zwei bispezifische Antikörper gegen verschiedene Epitope des humanen Immunglobulin E, die spezifisch membranständiges IgE (mIgE) erkennen und rezeptorgebundenes, lösliches IgE auf Mastzellen und Eosinophilen unberührt lassen. Membranständiges Immunglobulin E wird von Gedächtnis IgE+ B-Zellen, deren Vorläufern und, in sehr geringem Maß, von IgE-Plasmazellen auf der Zelloberfläche präsentiert. Diese verschiedenen Differenzierungsstadien von IgE+ B-Zellen sind für die Produktion und Aufrechterhaltung einer IgE-Immunantwort gegen Allergene verantwortlich und stellen das Ziel der hier betrachteten BiTE®-vermittelten Immuntherapie dar. Durch die Wahl dieser IgE-Epitope kann eine unkontrollierte Auschüttung von Histamin durch degranulierende Effektorzellen umgangen werden und eine sichere therapeutische Anwendung der IgE-BiTE®-Antikörper möglich werden. Während eines der gepaarten scFv-Fragmente, aus VH und VL der beiden BiTE®-Antikörper, die CD3ε-Kette des humanen T-Zellrezeptorkomplexes erkennt, so ist der jeweilige andere Arm des human IgE-spezifischen BiTE®-Moleküls für die Erkennung des IgE-Epitops verantwortlich. Die Bindung des IgE-CH3-BiTE®-Antikörper-Konstrukts von mIgE auf IgE+ B Zellen wird durch die Spezifität von einem der scFv-Fragmente für eine Region der CH3-Domäne des humanen IgE realisiert, die bei rezeptorgebundenem IgE nicht zugänglich ist. Die Entwicklung des IgE-CH3-BiTE®-Antikörper-Konstrukts führt, beginnend bei der Humanisierung eines bekannten murinen BiTE®-Moleküls, über die Selektion des BiTE®-Kandidaten anhand biochemischer und Charakteristika der Bioaktivität, zu einem in vitro und in vivo zytotoxischen BiTE®-Antikörper. Eigenschaften, wie die Kreuzreaktivität des Moleküls gegenüber Immunglobulin E und CD3 des Makaken, machen den IgE-CH3-BiTE®-Antikörper zudem zu einem wichtigen Instrument der Forschung. Unabhängig von der auf diesem Weg möglichen Evaluierung des Zielantigens und der Ermittlung der Verträglichkeit des therapeutischen BiTE®-Kandidaten an Makaken, kann der Einsatz des Moleküls neue Erkenntnisse zur Entwicklung der Immunglobulin E-Immunantwort und der Differenzierung mIgE+ B-Zellen liefern. Das zweite BiTE®-Molekül, das IgE-CεmX-BiTE®-Antikörper-Konstrukt, verwendet eine Besonderheit des membranständigen Immunglobulin E des Menschen und der Altweltaffen als Zielstruktur. Die Struktur des humanen mIgE unterscheidet sich von der anderer Spezies durch ein 52 Aminosäuren langes Segment, CεmX, zwischen der CH4-und der ε-Migis-Domäne. Basierend auf den Forschungsergebnissen von Brightbill und Kollegen wurde ein CεmX-spezifischer BiTE®-Antikörper entwickelt, der den Eigenschaften des IgE-CH3-BiTE®-Antikörper-Konstrukts ähnelt. Die bereits humanisierte DNS-Sequenz, die zytotoxische Wirksamkeit und die gute Ausbeute des Moleküls nach der Expression in Säugetierzellen, legen, zusammen mit der Exklusivität des CεmX-Segments auf mIgE+ B-Zellen, nahe, dass dieses Konstrukt zu einem Therapeutikum weiterentwickelt werden könnte. Die Ergebnisse dieser Arbeit stellen zwei Kandidaten zur therapeutischen Anwendung bei allergischen Erkrankungen vor. Basierend auf der erfolgreichen Anwendung des bispezifischen Antikörpers Blincyto® versprechen diese ebenfalls B-Zell-spezifischen BiTE®-Antikörper einen neuen immuntherapeutischen Ansatz für atopische Patienten

Untersuchungen zur Korrelation von individuellen Risikofaktoren mit den klinischen, radiologischen und histologischen Parametern sowie mit Entzündungsmediatoren in der Synovialflüssigkeit von Gelenken mit Arthrose

Die Arthrose gehört zu den epidemiologisch bedeutendsten chronischen Gelenkerkrankungen weltweit. Ursprünglich galt sie als einfache Verschleißerkrankung. Neuere Studien zeigen, dass auch geringgradige Entzündungsprozesse im Gelenk eine Schlüsselrolle spielen. Bis heute existiert keine spezifische Therapie, daher sind Untersuchungen zum Einfluss von Risikofaktoren auf die Entzündungsprozesse und die klinischen Beschwerden um neue Therapien zu entwickeln von großem Interesse. In dieser Arbeit konnte gezeigt werden, dass es Korrelationen zwischen Risikofaktoren mit metabolischem Einfluss und den klinischen Beschwerden bei Arthrose sowie den Entzündungsprozessen im Gelenk gibt. Besonders deutlich war dies bei Patienten mit Diabetes mellitus. Darüber hinaus konnte diese Arbeit einen Zusammenhang zwischen den klinischen Beschwerden, insbesondere den Gelenkschmerzen bei Arthrose, und den Entzündungsprozessen im Gelenk nachweisen. Dagegen gab es keine Korrelationen zwischen den klinischen Beschwerden und der K&L-Klassifikation. Die Studie bestätigt, dass sowohl das zunehmende Alter als auch eine Achsfehlstellung als mechanischer Risikofaktor zu stärkeren strukturellen Veränderungen am Knochen und zu einem höheren Grad der Arthrose nach der K&L- Klassifikation führt. Die Ergebnisse der Arbeit zeigen die Bedeutung von individuellen Risikofaktoren für die Gelenkschmerzen und Beschwerden von Patienten mit Arthrose sowie für die histologischen Veränderungen des Synovialgewebes und Entzündungsmediatoren in der Synovialflüssigkeit und liefern so grundlegende Erkenntnisse für die Entwicklung von spezifischen Behandlungsstrategien

Untersuchungen zur Gefäßfunktion der humanen A. mammaria interna nach Kaltlagerung in Kombination mit antimikrobieller Dekontamination

Ziel dieser Arbeit war die Verbesserung der Qualität und Vitalität von Gefäßtransplantaten bei Kaltlagerung. Optimiert wurden antimikrobiell wirksame Gefäßprotektionslösungen unter der Berücksichtigung der strengen Auflagen des Arzneimittelgesetzes (AMG). Für die umfangreichen Untersuchungen sind gesetzliche Mindestzeiten von bis zu einer Woche festgelegt. Für die antimikrobielle Dekontamination der Grafts wird ein Zeitraum zwischen 20 und 48 Stunden angegeben. In dieser Studie wurde die bereits sehr erfolgreich getestete Protektionslösung TiProtec® für Kaltlagerungsbedingungen genutzt. Zur Evaluierung der Gefäßfunktionen wurde die humane A. mammaria interna verwendet. Bei den Funktionsmessungen wurden die Wandspannungsentwicklung durch die rezeptorabhängige und rezeptorunabhängige Konstriktion sowie die endothelabhängige und die endothelunabhängige Vasodilatation evaluiert. Getestet wurden kurze Lagerungszeiten von 2 bis 48 Stunden sowie lange Lagerungszeiten von 96 Stunden bis zu einer Woche. Des Weiteren wurde überprüft, ob die Lagerung der Arteriensegmente für 48 Stunden in einer speziellen Lagerungslösung mit anschließender Umlagerung für weitere fünf Tage in TiProtec® eine Verbesserung der Funktionalität bewirkte. Untersucht wurden vier antimikrobielle Dekontaminationslösungen. Neben der Vergleichsgruppe mit TiProtec®-Lösung ohne Zusatz, wurden als Zusätze die Antibiotikamixtur 1 (Gentamicin, Clindamycin, Flucloxacillin, Metronidazol, Fluconazol und Itraconazol), Antibiotikamixtur 2 ( Gentamicin, Clindamycin, Metronidazol und Fluconazol) und das Antiseptikum Taurolidin in den Konzentrationen 0,5% und 0,002% verwendet

Longitudinal Effects of the Family Support Program Chancenreich on Parental Involvement and the Language Skills of Preschool Children

When they enter primary school children already vary significantly in their language skills, depending at least in part on their family’s social background. In particular, the home learning environment plays a significant role in children’s development. For that reason, early intervention programs have been developed to obviate learning difficulties and to promote health, children’s development, and educational equality. The family support program Chancenreich aims to encourage the interaction and relationship between parents and children through two different course formats. The present study examines the longitudinal effects of attending the Chancenreich program and different course formats on (a) parents attending further educational services for children after completing the program, (b) children’s vocabulary and level of grammar development at the age of 5 and (c) the children’s vocabulary development between the ages of 3 and 5. Furthermore, we examine the relationship between family characteristics and the attendance rates of different course formats of the Chancenreich program at the first and second point of measurement. The study follows a longitudinal design with two points of measurements (T1: Mage = 41 months, T2: Mage = 68 months), and a sample size of 121 parents and their children at T2 in the intervention group and 41 parents and their children in the comparison group. Findings indicate that attendance of the Chancenreich program’s courses is related to child and family characteristics and to later patterns of course participation after completing the program. Further, both children’s level of vocabulary skills (PPVT) at the age of 5 and their development between the ages of 3 and 5 benefit from the parental participation in parenting skills training at the age of 3. Implications and future research on the effectiveness of family support programs are discussed

On the role of allergen-specific IgG subclasses for blocking human basophil activation.

Successful treatment of IgE mediated allergies by allergen-specific immunotherapy (AIT) usually correlates with the induction of allergen-specific IgG4. However, it is not clear whether IgG4 prevents the allergic reaction more efficiently than other IgG subclasses. Here we aimed to compare allergen-specific monoclonal IgG1 and IgG4 antibodies in their capacity to inhibit type I allergic reactions by engaging FcγRIIb. We found that IgG1, which is the dominant subclass induced by viruses, binds with a similar affinity to the FcγRIIb as IgG4 and is comparable at blocking human basophil activation from allergic patients; both by neutralizing the allergen as well as engaging the inhibitory receptor FcγRIIb. Hence, the IgG subclass plays a limited role for the protective efficacy of AIT even if IgG4 is considered the best correlate of protection, most likely simply because it is the dominant subclass induced by classical AITs

Quality of early learning environments : measures, validation, and effects on child development

Individual differences and disparities in educationally relevant competencies and skills evolve from the very beginning of a child’s life. This chapter focuses on early learning environments as an important basis for acquiring those competencies and skills that depend and impact on education. Drawing on the Newborn Cohort Study of the German National Educational Panel Study (NEPS-SC1) and additional validation studies, we address and empirically evaluate different quality measures of parenting behaviour and extrafamilial childcare along with their effects on early child outcomes. Results highlight the importance of considering differentiated measures of early learning environments such as indicators of cognitive-verbal stimulation or parental responsive emotional support from the very beginning, because these relate differentially to various domains of early child development. Furthermore, although different facets of interaction quality are associated with socio-economic family characteristics (SES), they relate to each other only moderately. In addition, we report on the validity and effects of quality measures of early external childcare in the NEPS-SC1 and discuss the emergence of individual differences and SES-related disparities in early child development