Search

Ice formation and growth play a critical role in the initiation of precipitation. However, fundamental knowledge gaps in microphysical processes exist, for example, in the efficiency of diffusional growth of ice crystals, which leads to uncertainties in weather forecasts and climate projections. The CLOUDLAB project aims to bridge this gap by using supercooled stratus clouds as a natural laboratory for glaciogenic cloud seeding experiments. Ice nucleating particles (particles containing mainly silver iodide) are dispersed into these clouds via an Uncrewed Aerial Vehicle (UAV), triggering ice crystal formation and growth. The use of a UAV for seeding in conjunction with the persistent nature of stratus clouds enables repeated seeding experiments under similar and well-constrained initial conditions.So far, 50 seeding experiments with seeding temperatures between -10°C and -3°C were conducted in clouds over the Swiss plateau. The seeding-induced microphysical changes were monitored using in-situ and ground-based remote sensing equipment positioned 3-15 minutes downstream of the seeding location. The seeding plume had an extent of multiple hundreds of metres and was detected by increased reflectivity in the vertically pointing and scanning cloud radars (additional instrumentation was provided by TROPOS in the frame of the accompanying PolarCAP project). Simultaneously, high concentrations of small ice crystals were detected with a holographic imager mounted on a tethered balloon. The findings are contextualized with simulations using the numerical weather model (ICON).&nbsp

Low stratus clouds are a commonly occurring phenomenon over the Swiss Plateau during wintertime and can last up to several days. This almost stable characteristic is exploited in the CLOUDLAB project, which aims to gain a more profound understanding of ice crystal formation and growth by introducing seeding particles into a supercooled liquid cloud, thus initiating glaciation of the cloud. The seeding particles (silver iodide) are injected into the dynamically stable cloud from a drone enabling a highly precise and repetitive experimental setup. By observing the microphysical changes via an extensive observational setup of remote sensing and in-situ instrumentation, the low stratus clouds effectively serve as a natural laboratory for seeding experiments.To further our understanding of the occurring processes, we employ the ICON-NWP model in large-eddy mode with a horizontal resolution of up to 65 m to simulate the conducted experimental conditions. The existing two-moment microphysics scheme is supplemented by a seeding parameterization allowing us to mimic the ice nucleation behavior of the seeding particles. While it remains a challenge for numerical models to adequately represent low stratus, we successfully simulated several seeding experiments. Here, we present first comparisons between model simulations and observational data in the form of case studies and show the potential of ICON-NWP for interpreting our seeding signals., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The formation and growth of ice in clouds are essential for precipitation formation. Despite advances in our understanding of ice phase processes arising from laboratory and modeling studies, a major gap exists in representative in-situ field observations. CLOUDLAB aims to fill this gap by performing targeted glaciogenic cloud seeding experiments (using silver iodide injections) in supercooled, predominantly liquid stratus clouds over the Swiss Plateau to induce ice crystal formation and subsequent growth processes. Downwind of the seeding location, the freshly generated ice crystals are observed using two scanning cloud radars and a tethered balloon system equipped with an optical particle counter and holographic imager. The holographic imager captures phase-resolved information about the number, size, and spatial distributions of hydrometeors with high spatio-temporal resolution (>6 µm, 40 Hz).We present in-situ and remote sensing data observed during a series of cloud seeding experiments. The ice crystal and aerosol number concentrations increased by several orders of magnitudes during the passage of the seeding plume. Simultaneously at the same location, the radar reflectivity increased by 10 to 20 dB compared to the unseeded background cloud. The observed ice crystals formed three to fifteen minutes before the detection and grew to a diameter of around 100-200 µm. We will also assess how the seeding influences the liquid phase (e.g. liquid water content, cloud droplet size) and answer the question: Does the seeding produce fully glaciated patches? This dataset provides unique insights into early-stage ice processes and broadens our understanding of precipitation formation., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Background and Purpose: Nurses may experience moral distress because of workplace constraints. Due to its possible adverse effects, it is advisable to continuously monitor moral distress. In 2010 no suitable instrument existed within the German-speaking context. Hence the purpose of this study was to[for full text, please go to the a.m. URL], 1st International Conference of the German Society of Nursing Science

Background and Purpose: The growing economic pressure in healthcare may lead to a decrease of quality of nursing care and patient safety as well as an increase of the difficulty of recruiting and retaining nurses. Consequently, a monitoring of nursing service context factors and their impact on outcomes[for full text, please go to the a.m. URL], 1st International Conference of the German Society of Nursing Science

Introduction:When caring for cancer patients, finding an appropriate screening instrument to identify and assess increased psychosocial distress is crucial. In 2012, we implemented the Distress Thermometer (DT) at the Comprehensive Cancer Center at the University Hospital Zurich (USZ). Since then, the DT has been routinely used by nurses with all cancer inpatients.ObjectivesTo identify adherence to the screening guideline and the documented benefits of the DT screening.MethodsThis retrospective descriptive study evaluated the distress screening since 2012. Data of all patients treated in the USZ were included. Every inpatient who was screened using the DT at least once during the treatment was labeled as screened. The data was collected from the electronic patient documentation system and analyzed descriptively.ResultsSince 2012, 11 184 patients have been treated. In total, 15 095 screenings were documented and 40.6 % of the patients were screened. Male, married and emergency patients and patients with hematology diseases, brain tumors or head and neck cancer were screened more frequently (p< 0.001). More female, younger, single and emergency patients wished to be transferred to the psychooncology service (p

Hintergrund: Am Universitätsspital Zürich wurde das Projekt ‚Behandlungspfad Brandverletzte’ gestartet. Dies mit dem Ziel, die Prozesse in der Behandlung und Betreuung von Brandverletzten zu analysieren und verbessern und das Selbstmanagement bei den Betroffenen (Brandverletzte[for full text, please go to the a.m. URL], DAV 2011; 29. Jahrestagung der Deutschsprachigen Arbeitsgemeinschaft für Verbrennungsbehandlung

Hintergrund: Im Rahmen des Projektes "Behandlungspfad Brandverletzte" war es den Verantwortlichen ein Anliegen, zu Projektbeginn die Perspektive der Brandverletzten und deren Angehörigen mit einzubeziehen. Folgende Fragen wurden untersucht: Wie erleben Brandverletzte und ihre Angehörigen[for full text, please go to the a.m. URL], DAV 2011; 29. Jahrestagung der Deutschsprachigen Arbeitsgemeinschaft für Verbrennungsbehandlung

Between 1984-1990 80 secondary implantations of an anterior chamber lens in aphakic eyes have been completed. The average follow-up period was 3.1 years, some of the patients checked on during the last 6 years. The most relevant complications to mention being retinal detachment (2), as well as cystoid macular edema (1). These complications appeared in patients in whom a vitrectomy had to be performed simultaneously. Other complications like corneal dystrophy, glaucoma or lens dislocations were not observed. The risk is increased when there is the need to perform a vitrectomy simultaneously. In cases without vitrectomy the risk is slight.

Acanthamoeba keratitis was seen in two contact-lens wearers. In both cases, this finding was verified by microbiological examination of conjunctival swabs and of the lens solution. One patient had perforating keratoplasty. While neither vital amoebae nor cysts could be detected in the host corneal explant, immunohistochemical examination revealed fluorescence-positive fragments which probably correspond to incomplete cycstic walls.