170 research outputs found
W42 - a scalable spatial database system for holding Digital Elevation Models
The design of a scalable system for holding spatial data in general and digital elevation models (DEMs) in specific has to account for the characteristics of data from various application fields. The data can be heterogeneous in coverage, as well as in resolution, information content and quality. A database aiming at the representation of world-wide DEMs has to consider these differences in the design of the system with respect to the structure and the algorithms. The database system W42, which is presented in the work at hand, is a scalable spatial database system capable of holding, extracting, mosaicking, and fusing spatial data represented in raster- as well as in vector-format. Design aspects for this task can be specified as holding spatial data in unique data structures and providing unique access functions to the data. These are subject of this work as well as first experiences gained from the implementation of part of the extensions made for the TanDEM-X mission
Klimaschutz in der Landwirtschaft - Emissionsminderung in der Praxis
Die nationalen Minderungsziele der Bundesregierung fĂźr Treibhausgase sind nur durch eine drastische Reduzierung der Emissionen in allen Bereichen zu realisieren. Das Heft soll Landwirte dabei unterstĂźtzen, einen Beitrag zur langfristig anvisierten Halbierung der Treibhausgasemissionen Deutschlands zu leisten. Landwirtschaftliche Produktionsverfahren bieten zahlreiche Ansatzpunkte fĂźr eine wirkungsvolle Treibhausgasminderung. Vor allem die Verbesserung der Stickstoffausnutzung sollte hier im Fokus stehen. Weitere MaĂnahmenfelder, fĂźr die im Heft EinzelmaĂnahmen dargestellt werden, sind Ertrags- bzw. Leistungssicherung und Verlustminimierung, der Erhalt und Aufbau von Humus sowie die Verringerung des Energieaufwands. Zusätzlich zur Minderung der Treibhausgasemissionen ergeben sich in vielen Fällen positive Effekte fĂźr andere Umweltziele und SchutzgĂźter, wie Biodiversität, Luftreinhaltung und Gewässerschutz, oder fĂźr das Tierwohl. Einige MaĂnahmen ermĂśglichen eine Kosteneinsparung, z.B. durch eine Verringerung des MineraldĂźngereinsatzes, sodass sich Klimaschutz auch unter wirtschaftlichen Gesichtspunkten fĂźr den Einzelbetrieb auszahlen kann
Eisosome ultrastructure and evolution in fungi, microalgae, and lichens
Eisosomes are among the few remaining eukaryotic cellular differentations that lack a defined function(s). These trough-shaped invaginations of the plasma membrane have largely been studied in Saccharomyces cerevisiae, in which their associated proteins, including two BAR domain proteins, have been identified, and homologues have been found throughout the fungal radiation. Using quick-freeze deep-etch electron microscopy to generate high-resolution replicas of membrane fracture faces without the use of chemical fixation, we report that eisosomes are also present in a subset of red and green microalgae as well as in the cysts of the ciliate Euplotes. Eisosome assembly is closely correlated with both the presence and the nature of cell walls. Microalgal eisosomes vary extensively in topology and internal organization. Unlike fungi, their convex fracture faces can carry lineage-specific arrays of intramembranous particles, and their concave fracture faces usually display fine striations, also seen in fungi, that are pitched at lineage-specific angles and, in some cases, adopt a broad-banded patterning. The conserved genes that encode fungal eisosome-associated proteins are not found in sequenced algal genomes, but we identified genes encoding two algal lineage-specific families of predicted BAR domain proteins, called Green-BAR and Red-BAR, that are candidate eisosome organizers. We propose a model for eisosome formation wherein (i) positively charged recognition patches first establish contact with target membrane regions and (ii) a (partial) unwinding of the coiled-coil conformation of the BAR domains then allows interactions between the hydrophobic faces of their amphipathic helices and the lipid phase of the inner membrane leaflet, generating the striated patterns
Colony organization in the green alga Botryococcus braunii (Race B) is specified by a complex extracellular matrix
Botryococcus braunii is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of B. braunii cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous β-1, 4- and/or β-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form âdrapesâ between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM
On the way to the "best childrens´s university": The supply and demand relationship under the principle of partcipation. Opportunities and challenges raised by the children´s university
I know the childrenâs university is the best university in the world,â says Elisabeth, who is 9 years old and an attendee at the childrenâs university in Vienna. This charming compliment paid to the childrenâs university organizers raises an opportunity for further critical inquiries. The statement puts ârealâ universities on a par with childrenâs universities and therefore contains the implicit question of the status of childrenâs universities in the educational landscape: as a hybrid of formal and non-formal education. The specialist conference âOn the way to the âbest Childrenâs Universityâ: The Supply and Demand Relationship under the Principle of Participation. Opportunities and Challengesâ, took place from 8 to 10 May at the University of Cologne, addressed this intermediate position in all its facets. Further topics were possibilities for getting children involved as equal partners, and an international comparison of childrenâs university models. The conference was funded by the Ford Foundation and supported by KĂślnAlumni â Freunde und FĂśrderer der Universität e.V. It was organized in partnership with the international childrenâs university network EUCUNET along with the multinational EU project âSiSCatalyst. Children as change agents for science and societyâ
Increased plasma zonulin in patients with sepsis
Introduction: Zonulin is a eukaryotic protein structurally similar to Vibrio choleraeâs zonula occludens toxin. It plays an important role in the opening of small intestine tight junctions. The loss of gut wall integrity during sepsis might be pivotal and has been described in various experimental as well as human studies. Increased levels of zonulin could be demonstrated in diseases associated with increased intestinal inflammation, such as celiac disease and type 1 diabetes. We therefore investigated the role of plasma levels of zonulin in patients with sepsis as a non-invasive marker of gut wall integrity.
Materials and methods: Plasma level of zonulin was measured in 25 patients with sepsis, severe sepsis or septic shock according to ACCP/SCCM criteria at the first day of diagnosed sepsis. 18 non-septic post-surgical ICU-patients and 20 healthy volunteers served as control. Plasma levels were determined by using commercially available ELISA kit. Data are given as median and interquartile range (IQR).
Results: Significantly higher plasma concentration of zonulin were found in the sepsis group: 6.61 ng/mL (IQR 3.51-9.46), as compared to the to the post-surgical control group: 3.40 ng/mL (IQR 2.14-5.70) (P = 0.025), as well as to the healthy group: 3.55 ng/mL (IQR 3.14-4.14) (P = 0.008).
Conclusion: We were able demonstrate elevated levels of plasma zonulin, a potential marker of intestinal permeability in septic patients. Increased zonulin may serve as an additional mechanism for the observed increased intestinal permeability during sepsis and SIRS
Antibiotic prophylaxis in transurethral resection of bladder tumours: study protocol for a systematic review and meta-analysis
The necessity of antibiotic prophylaxis for postoperative urinary tract infections (UTIs) after transurethral resection of bladder tumours is controversial. This potentially leads to the overuse of antibiotic prophylaxis and rising antimicrobial resistance rates. The objective of this systematic review and meta-analysis is to compare the impact of different antimicrobial prophylaxis schemes versus placebo on the prevention of postoperative UTI and asymptomatic bacteriuria.; We designed and registered a study protocol for a systematic review and meta-analysis of randomized controlled trials and non-randomized (e.g. cohort, case-control) studies examining any form of antibiotic prophylaxis in patients with transurethral resection of bladder tumours. Literature searches will be conducted in several electronic databases (from inception onwards), including MEDLINE (Ovid), EMBASE (Ovid), and the Cochrane Central Register of Controlled Trials (CENTRAL). Grey literature will be identified through searching conference abstracts. The primary outcome will be postoperative urinary tract infections. The secondary outcome will be asymptomatic bacteriuria. Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The study methodological quality (or bias) will be appraised using appropriate tools (e.g. Risk of Bias 2.0 tool and Newcastle-Ottawa Scale). If feasible, we will conduct random-effects meta-analysis of outcome data. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. study design, publication year, the setting of the study, and antibiotics regimen). We will also search, identify, and discuss potential risk factors for urinary tract infections following transurethral resection of bladder tumours. This may serve as basis for a scoping review.; In times of rising antimicrobial resistance rates, sound evidence on the necessity of antibiotic prophylaxis is essential for implementation into guideline recommendations and for decision-making in clinical practice
Shaping the Global High-Resolution TanDEM-X Digital Elevation Model
The global digital elevation model (DEM) produced by the TanDEM-X (TerraSAR-X add-on for digital elevation measurements) mission is an interferometric elevation model with unprecedented quality, accuracy, and coverage. It represents an unedited surface model as artifacts inherent to the interferometric synthetic aperture radar acquisition and processing technique are still present. The most prominent artifacts in the DEM are water bodies appearing with a rough surface due to low coherence. Additionally, outliers, voids, and larger data gaps may be present in this dataset. Therefore,DEM editing is crucial for many applicationsincluding hydrology or orthorectification of remote sensing data. Depending on the field of application, different techniques of quality enhancement are required. This article provides a comprehensive description of a semi-automatic framework specially developed for generating an edited version of the TanDEM-X dataset by shaping the high-resolution 12 m DEM with focus on water areas, outlier handling, and void filling. The default configuration parameters of the workflow can thereby be adapted interactively for challenging areas where appropriate. A quality assessment of the resulting edited DEM was done by statistical measures, visual methods, as well as by an artifact evaluation
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