Investigating the 2005 Singaporean Dengue Outbreak

Master'sJOINT M.SC. IN INFECTIOUS DISEASES, VACCINOLOGY AND DRUG DISCOVER

Lipidomics of Influenza Virus: Implications of Host Cell Choline-and Sphingolipid Metabolism

Ph.DDOCTOR OF PHILOSOPH

Hot water versus herbicides – Swiss railways renounce herbicide use by 2025

Die Schweizerischen Bundesbahnen (SBB, CFF, FFS) verwendeten bis Anfangs der 1990er Jahre Atrazin, um die Vegetation am Gleis zu kontrollieren. Das Herbizid wurde großflächig und undifferenziert versprüht, was zu erheblicher Belastung von Grund- und Oberflächenwasser mit Herbizidrückständen führte. Mitte der 1990er Jahre war das Atrazin gänzlich von Glyphosat abgelöst worden. Kleine Teams gehen noch heute mit der Rückenspritze die Zugstrecken ab und applizieren das Herbizid mit der Rückenspritze. Auf Grund der aktuell weltweiten Bedenken gegen den Einsatz von Herbiziden und Pflanzenschutzmitteln allgemein haben sich die SBB zum Ziel gesetzt, Alternativen für die Vegetationskontrolle im Gleisbereich zu fördern und zu entwickeln. 2018 wurden erste positive Erfahrungen mit der Applikation von Heißwasser gemacht. Daraufhin bauten die SBB 2019 den Prototypen eines Heißwasserspritzzuges. Im Rangierbahnhof Basel bei Muttenz wurden die Effekte Heißwasserbehandlungen mit denen der Glyphosat Applikation und einer Kontrolle unbehandelt verglichen. Agroscope hat mit Vegetationsaufnahmen das Potential der Heißwasserapplikation aufgezeigt.Swiss railways (SBB, CFF, FFS) used atrazin up until the end of the 1980s along railway tracks for controlling the vegetation. The herbicide was sprayed in large scales and indiscriminate use. Glyphosate replaced atrazine as main herbicide from the early 1990s until today. Small crews walking along tracks apply the herbicide as single plant treatment with knapsack sprayers. Because of increasing discredit of glyphosate in public, Swiss railways decided to search for alternatives to herbicides. A tight goal was defined: within three years, a train running with 40 km/h on track must be able to apply hot water in sufficient quantities for killing the vegetation growing in the ballast and on the sidewalks. In 2018, first attempts were made for applying hot water on a railway tracks out of service. In spring 2019, a prototype of the spray train did its first steps – around 200 km – on open tracks spraying hot water day and night. The technique of the spray train is explained in this paper. Agroscope assessed the effects of hot water treatment compared with glyphosate application and “untreated” on four tracks in the Basel freight yard. The effects on vegetation of four treatments were compared and are presented

Correlative light electron microscopy using small gold nanoparticles as single probes

Correlative light electron microscopy (CLEM) requires the availability of robust probes which are visible both in light and electron microscopy. Here we demonstrate a CLEM approach using small gold nanoparticles as a single probe. Individual gold nanoparticles bound to the epidermal growth factor protein were located with nanometric precision background-free in human cancer cells by light microscopy using resonant four-wave-mixing (FWM), and were correlatively mapped with high accuracy to the corresponding transmission electron microscopy images. We used nanoparticles of 10 nm and 5 nm radius, and show a correlation accuracy below 60 nm over an area larger than 10 um size, without the need for additional fiducial markers. Correlation accuracy was improved to below 40 nm by reducing systematic errors, while the localisation precision is below 10 nm. Polarisation-resolved FWM correlates with nanoparticle shapes, promising for multiplexing by shape recognition in future applications. Owing to the photostability of gold nanoparticles and the applicability of FWM microscopy to living cells, FWM-CLEM opens up a powerful alternative to fluorescence-based methods

A picture worth a thousand words: how career website images influence application intentions

Organizations are motivated to persuade qualified applicants to apply for open positions so they can identify and select higher-quality candidates (Phillips & Gully, 2015). As organizations realize the value of a diverse workforce, they have deployed recruitment strategies to attract underrepresented applicants (Greenberg, 2015). Studies conducted in 2003 and 2006 by Avery and McKay suggested that targeted recruitment advertisements positioning non-White employees as recognized and included in the organization increased non-White job seeker attraction to the organization. It has not yet been examined if this same effect extends to White members of other marginalized groups - specifically White and non-White members of the LGBTQ+ community (Avery & McKay, 2006; Walker et al., 2011). This study will examine the effects that images on a company’s “Careers Page\u27\u27 web page have on the application intentions of applicants of different race/ethnic and LGBTQ+ identities. We will test four hypotheses with this study: Hypothesis One (H1): Images portraying a racially and ethnically diverse workforce will positively affect application intentions of non-White applicants Hypothesis Two (H2): Images portraying a LGBTQ+ symbolism will positively affect application intentions of LGBTQ+ applicants. Hypothesis Three (H3): Images representing one marginalized group will have positive, but slightly smaller effects on the application intentions of other marginalized groups. Hypothesis Four (H4): Application intentions of White applicants will remain unaffected by images portraying a racially and ethnically diverse workforce. These hypotheses will be tested in a 2x2x2 quasi-experiment, where we will measure the application intentions between groups of non-White job applicants and White job applicants. The application intentions of those who identify as LGBTQ+, or not, will also be examined. Study participants will be be presented with one of four different images on a mock web page: an image portraying no racial or ethnic diversity, an image portraying no racial or ethnic diversity with LGBTQ+ symbolism, an image portraying a racially and ethnically diverse workforce, or an image portraying a racially and ethnically diverse workforce with LGBTQ+ symbolism. Participation will be solicited from students completing their undergraduate degree at universities or community colleges. Findings from this study will quantify the effect elements of website images supporting diversity and inclusion have on different applicants’ application intentions. We will be able to better understand if the perception of any marginalized identity in the workforce, whether or not it is the applicant’s identity, increases the perception that one would be welcomed and included there

Aerogel Waveplates

Optical transmission measurements were made on 98% porosity silica aerogel samples under various degrees of uniaxial strain. Uniaxially compressed aerogels exhibit large birefringence, proportional to the amount of compression, up to the 15% strain studied. The birefringence is mostly reversible and reproducible through multiple compression-decompression cycles. Our study demonstrates that uniaxially strained high porosity aerogels can be used as tunable waveplates in a broad spectral range.Comment: 7 pages, 4 figures, submitted to Optics Expres

Health & Demographic Surveillance System Profile: The Taabo Health and Demographic Surveillance System, Côte d'Ivoire

The Taabo Health and Demographic Surveillance System (HDSS) is located in south-central Côte d'Ivoire, approximately 150 km north-west of Abidjan. The Taabo HDSS started surveillance activities in early 2009 and the man-made Lake Taabo is a key eco-epidemiological feature. Since inception, there has been a strong interest in research and integrated control of water-associated diseases such as schistosomiasis and malaria. The Taabo HDSS has generated setting-specific evidence on the impact of targeted interventions against malaria, schistosomiasis and other neglected tropical diseases. The Taabo HDSS consists of a small town, 13 villages and over 100 hamlets. At the end of 2013, a total population of 42 480 inhabitants drawn from 6707 households was under surveillance. Verbal autopsies have been conducted to determine causes of death. Repeated cross-sectional epidemiological surveys on approximately 5-7% of the population and specific, layered-on haematological, parasitological and questionnaire surveys have been conducted. The Taabo HDSS provides a database for surveys, facilitates interdisciplinary research, as well as surveillance, and provides a platform for the evaluation of health interventions. Requests to collaborate and to access data are welcome and should be addressed to the secretariat of the Centre Suisse de Recherches Scientifiques en Côte d'Ivoire: [[email protected]

A Randomized Placebo-Controlled Phase Ia Malaria Vaccine Trial of Two Virosome-Formulated Synthetic Peptides in Healthy Adult Volunteers

BACKGROUND AND OBJECTIVES: Influenza virosomes represent an innovative human-compatible antigen delivery system that has already proven its suitability for subunit vaccine design. The aim of the study was to proof the concept that virosomes can also be used to elicit high titers of antibodies against synthetic peptides. The specific objective was to demonstrate the safety and immunogenicity of two virosome-formulated P. falciparum protein derived synthetic peptide antigens given in two different doses alone or in combination. METHODOLOGY/PRINCIPAL FINDINGS: The design was a single blind, randomized, placebo controlled, dose-escalating study involving 46 healthy Caucasian volunteers aged 18-45 years. Five groups of 8 subjects received virosomal formulations containing 10 microg or 50 microg of AMA 49-CPE, an apical membrane antigen-1 (AMA-1) derived synthetic phospatidylethanolamine (PE)-peptide conjugate or 10 ug or 50 ug of UK39, a circumsporozoite protein (CSP) derived synthetic PE-peptide conjugate or 50 ug of both antigens each. A control group of 6 subjects received unmodified virosomes. Virosomal formulations of the antigens (designated PEV301 and PEV302 for the AMA-1 and the CSP virosomal vaccine, respectively) or unmodified virosomes were injected i. m. on days 0, 60 and 180. In terms of safety, no serious or severe adverse events (AEs) related to the vaccine were observed. 11/46 study participants reported 16 vaccine related local AEs. Of these 16 events, all being pain, 4 occurred after the 1(st), 7 after the 2(nd) and 5 after the 3(rd) vaccination. 6 systemic AEs probably related to the study vaccine were reported after the 1(st) injection, 10 after the 2(nd) and 6 after the 3(rd). Generally, no difference in the distribution of the systemic AEs between either the doses applied (10 respectively 50 microg) or the synthetic antigen vaccines (PEV301 and PEV302) used for immunization was found. In terms of immunogenicity, both PEV301 and PEV302 elicited already after two injections a synthetic peptide-specific antibody response in all volunteers immunized with the appropriate dose. In the case of PEV301 the 50 microg antigen dose was associated with a higher mean antibody titer and seroconversion rate than the 10 microg dose. In contrast, for PEV302 mean titer and seroconversion rate were higher with the lower dose. Combined delivery of PEV301 and PEV302 did not interfere with the development of an antibody response to either of the two antigens. No relevant antibody responses against the two malaria antigens were observed in the control group receiving unmodified virosomes. CONCLUSIONS: The present study demonstrates that three immunizations with the virosomal malaria vaccine components PEV301 or/and PEV302 (containing 10 microg or 50 microg of antigen) are safe and well tolerated. At appropriate antigen doses seroconversion rates of 100% were achieved. Two injections may be sufficient for eliciting an appropriate immune response, at least in individuals with pre-existing anti-malarial immunity. These results justify further development of a final multi-stage virosomal vaccine formulation incorporating additional malaria antigens. TRIAL REGISTRATION: ClinicalTrials.gov NCT00400101