Cloud-fraction-dependent bias in satellite liquid water path retrievals of shallow, non-precipitating marine clouds

This study compares Wentz microwave liquid water path retrievals with MODIS and MISR optical estimates in shallow, non-precipitating marine clouds. In overcast conditions, the microwave and optical estimates are comparable; however, as cloud fraction decreases microwave retrievals strongly and increasingly overestimate optical ones. This positive microwave bias cannot be explained neither by the elimination of negative values in the operational Wentz dataset, nor by the somewhat reduced sensitivity of MODIS cloud detection to small clouds

Profiles of Ocean surface Heating (POSH): A New Model of Upper Ocean Diurnal Warming

Shipboard radiometric measurements of diurnal warming at the ocean surface and profiles through the diurnal thermocline were utilized to assess the temporal and vertical variability and to develop a new physics-based model of near-surface warming. The measurements and modeled diurnal warming were compared, with the goal of comprehensively evaluating differences between the data and model results. On the basis of these results, the diurnal model was refined while attempting to maintain agreement with the measurements. Simplified bulk models commonly do not provide information on the vertical structure within the warm layer, but this new model predicts the vertical temperature profile within the diurnal thermocline using an empirically derived function dependent on wind speed. The vertical profile of temperature provides both a straightforward methodology for modeling differences due to diurnal warming between measurements made at different depths (e.g., in situ measurements at various depths and measurements of the surface temperatures by satellite radiometers) and information on upper ocean thermal structure. Additionally, the model estimates of diurnal warming at the ocean surface are important for air-sea heat and gas flux calculations, blending satellite sea surface temperature fields, and air-sea interaction studies. Copyright 2009 by the American Geophysical Union

Evaluation of laser induced sarcomere microdamage: Role of damage extent and location in cardiomyocytes

Whereas it is evident that a well aligned and regular sarcomeric structure in cardiomyocytes is vital for heart function, considerably less is known about the contribution of individual elements to the mechanics of the entire cell. For instance, it is unclear whether altered Z-disc elements are the reason or the outcome of related cardiomyopathies. Therefore, it is crucial to gain more insight into this cellular organization. This study utilizes femtosecond laserbased nanosurgery to better understand sarcomeres and their repair upon damage. We investigated the influence of the extent and the location of the Z-disc damage. A single, three, five or ten Z-disc ablations were performed in neonatal rat cardiomyocytes. We employed image-based analysis using a self-written software together with different already published algorithms. We observed that cardiomyocyte survival associated with the damage extent, but not with the cell area or the total number of Z-discs per cell. The cell survival is independent of the damage position and can be compensated. However, the sarcomere alignment/orientation is changing over time after ablation. The contraction time is also independent of the extent of damage for the tested parameters. Additionally, we observed shortening rates between 6-7% of the initial sarcomere length in laser treated cardiomyocytes. This rate is an important indicator for force generation in myocytes. In conclusion, femtosecond laser-based nanosurgery together with image-based sarcomere tracking is a powerful tool to better understand the Z-disc complex and its force propagation function and role in cellular mechanisms. Copyright

Bedeutung von NOD2 Polymorphismen bei Patienten mit Leberzirrhose und Aszites

In der vorgelegten Arbeit wurden 150 Patienten mit Leberzirrhose und Aszites untersucht und bezüglich ihres NOD2 Status genotypisiert. Es erfolgte die Genotypisierung hinsichtlich der bekannten Polymorphismen SNP 8, 12, und 13 im CARD 15-Gen (NOD2). Die Patienten wurden außerdem diagnostisch Aszites punktiert und es wurden weitere laborchemische Parameter, wie der Eiweißgehalt des Aszites, die Anzahl neutrophiler Granulozyten im Aszites und im Serum die Leukozytenzahl, CRP, Bilirubin und LDH erfasst. Die genannten NOD2 Polymorphismen sind als Risikoallele für das Auftreten eines Morbus Crohn beschrieben und das NOD2-Protein ist dabei ein zytoplasmatischer Sensor für Muramyl Dipeptid (MDP) einem Bestandteil der bakteriellen Zellwand. Bei Patienten mit Leberzirrhose und Aszites kommt es zu einer Translokaiton von Bakterien aus dem Darmlumen in die mesenterialen Lymphknoten und schließlich in den Aszites, wodurch eine Spontan Bakterielle Peritonitis (SBP) entstehen kann. Die in dieser Arbeit untersuchte Hypothese war, dass Patienten mit einem der genannten Polymorphismen eine gestörte Darmbarriere haben und es gehäuft zum Auftreten einer SBP kommt. Es konnte darüber hinaus gezeigt werden, dass Patienten mit einem der Polymorphismen eine deutlich kürze Überlebenzeit haben

Saildrone: Adaptively Sampling the Marine Environment

From 11 April to 11 June 2018 a new type of ocean observing platform, the Saildrone surface vehicle, collected data on a round-trip, 60-day cruise from San Francisco Bay, down the U.S. and Mexican coast to Guadalupe Island. The cruise track was selected to optimize the science team’s validation and science objectives. The validation objectives include establishing the accuracy of these new measurements. The scientific objectives include validation of satellite-derived fluxes, sea surface temperatures, and wind vectors and studies of upwelling dynamics, river plumes, air–sea interactions including frontal regions, and diurnal warming regions. On this deployment, the Saildrone carried 16 atmospheric and oceanographic sensors. Future planned cruises (with open data policies) are focused on improving our understanding of air–sea fluxes in the Arctic Ocean and around North Brazil Current rings

Mimicking acute airway tissue damage using femtosecond laser nanosurgery in airway organoids

Airway organoids derived from adult murine epithelial cells represent a complex 3D in vitro system mimicking the airway epithelial tissue’s native cell composition and physiological properties. In combination with a precise damage induction via femtosecond laser-based nanosurgery, this model might allow for the examination of intra- and intercellular dynamics in the course of repair processes with a high spatio-temporal resolution, which can hardly be reached using in vivo approaches. For characterization of the organoids’ response to single or multiple-cell ablation, we first analyzed overall organoid survival and found that airway organoids were capable of efficiently repairing damage induced by femtosecond laser-based ablation of a single to ten cells within 24 h. An EdU staining assay further revealed a steady proliferative potential of airway organoid cells. Especially in the case of ablation of five cells, proliferation was enhanced within the first 4 h upon damage induction, whereas ablation of ten cells was followed by a slight decrease in proliferation within this time frame. Analyzing individual trajectories of single cells within airway organoids, we found an increased migratory behavior in cells within close proximity to the ablation site following the ablation of ten, but not five cells. Bulk RNA sequencing and subsequent enrichment analysis revealed the differential expression of sets of genes involved in the regulation of epithelial repair, distinct signaling pathway activities such as Notch signaling, as well as cell migration after laser-based ablation. Together, our findings demonstrate that organoid repair upon ablation of ten cells involves key processes by which native airway epithelial wound healing is regulated. This marks the herein presented in vitro damage model suitable to study repair processes following localized airway injury, thereby posing a novel approach to gain insights into the mechanisms driving epithelial repair on a single-cell level

Climatological diurnal variability in sea surface temperature characterized from drifting buoy data

Drifting buoy sea-surface temperature (SST) records have been used to characterize the diurnal variability of ocean tem- perature at a depth of order 20 cm. We use measurements covering the period 1986–2012 from the International Com- prehensive Ocean-Atmosphere Data Set (ICOADS) version 2.5, which is a collection of marine surface observations that includes individual SST records from drifting buoys. Appropriately transformed, this dataset is well suited for estimation of the diurnal cycle, since many drifting buoys have high temporal coverage (many reports per day), and are globally distributed. For each drifter for each day, we compute the local-time daily SST variation relative to the local-time daily mean SST. Climatological estimates of subdaily SST variability are found by averaging across various strata of the data: in 10° latitudinal bands as well as globally; and stratified with respect to season, wind speed and cloud cover. A parame- terization of the diurnal variability is fitted as a function of the variables used to stratify the data, and the coefficients for this fit are also provided with the data. Results are consistent with expectations based on the previous work: the diurnal temperature cycle peaks in early afternoon (circa 2 pm local time); there is an increase in amplitude and a decrease in seasonality towards the equator. Generally, the ocean at this depth cools on windy days and warms on calm days, so that a component of subdaily variability is the SST tendency on slower timescales. By not ‘closing’ the diurnal cycle when stratified by environmental conditions, this dataset differs from previously published diurnal-cycle parameter- izations. This thorough characterization of the SST diurnal cycle will assist in interpreting SST observations made at different local times of day for climatological purposes, and in testing and constraining models of the diurnal-cycle and air-sea interaction at high temporal resolution