47 research outputs found
Optimal Bicycle Routes with Few Signal Stops
With the increasing popularity of cycling as a mode of transportation, there is a growing need for efficient routing algorithms that consider the specific requirements of cyclists. This paper studies the optimization of bicycle routes while minimizing the number of stops at traffic signals. In particular, we consider three different types of stopping strategies and three types of routes, namely paths, trails, and walks. We present hardness results as well as a pseudo-polynomial algorithm for the problem of computing an optimal route with respect to a pre-defined stop bound
Few recurring types of microdomains define smallest units of soilfunctioning
Soil aggregation is a key factor for a number of important biogeochemical processes (e.g. soil organic matter stabilization and nutrient and pollutant sorption) in soils. Although there is a large number of studies on the factors controlling such soil processes, it is still challenging to study these processes in-situ. However, it can be assumedthat the spatial arrangement of organic and mineral soil constituents in soil aggregates, and thus the aggregate structure determine the processes happening at the aggregate scale. Using nanoscale secondary ion mass spectroscopy and a novel digital image processing approach, we extensively analyzed the spatial distribution of ions characteristic for mineral and organic soil components on the micrometer-scale in an intact soil aggregate. We were surprised that 40 spatially independent measurements could be statistically clustered in just two complimentary types of micrometer-sized domains. Each domain is characterized by a micro-architecture built of a definitemineral assemblage with various organic matter forms and a specific pore system. Each of these microdomainsfulfil different functions in soil. Our results demonstrate that the manifold mineral and organic soil components arrange in a limited number of micro-architectures because of self-organization and feedback mechanisms. Thesemicrodomains are the smallest units in soil that fulfill specific functionalities
Genetic Survey of Psilocybe Natural Products
Psilocybe magic mushrooms are best known for their main natural product, psilocybin, and its dephosphorylated congener, the psychedelic metabolite psilocin. Beyond tryptamines, the secondary metabolome of these fungi is poorly understood. The genomes of five species ( P. azurescens , P. cubensis , P.â
cyanescens , P. mexicana , and P. serbica ) were browsed to understand more profoundly common and speciesâspecific metabolic capacities. The genomic analyses revealed a much greater and yet unexplored metabolic diversity than evident from parallel chemical analyses. P. cyanescens and P. mexicana were identified as aeruginascin producers. Lumichrome and verpacamide A were also detected as Psilocybe metabolites. The observations concerning the potential secondary metabolome of this fungal genus support pharmacological and toxicological efforts to find a rational basis for yet elusive phenomena, such as paralytic effects, attributed to consumption of some magic mushrooms
Atrial fibrillation is frequent but does not affect risk stratification in pulmonary embolism
Background:
Although prior studies indicate a high prevalence of atrial fibrillation (AF) in patients with pulmonary embolism (PE), the exact prevalence and prognostic impact are unknown.
Methods:
We aimed to investigate the prevalence, risk factors and prognostic impact of AF on risk stratification, in-hospital adverse outcomes and mortality in 528 consecutive PE patients enrolled in a single-centre registry between 09/2008 and 09/2017.
Results:
Overall, 52 patients (9.8%) had known AF and 57 (10.8%) presented with AF on admission; of those, 34 (59.6%) were newly diagnosed with AF. Compared to patients with no AF, overt hyperthyroidism was associated with newly diagnosed AF (OR 7.89 [2.99â20.86]), whilst cardiovascular risk comorbidities were more frequently observed in patients with known AF. Patients with AF on admission had more comorbidities, presented more frequently with tachycardia and elevated cardiac biomarkers and were hence stratified to higher risk classes. However, AF on admission had no impact on in-hospital adverse outcome (8.3%) and in-hospital mortality (4.5%). In multivariate logistic regression analyses corrected for AF on admission, NT-proBNP and troponin elevation as well as higher risk classes in risk assessment models remained independent predictors of an in-hospital adverse outcome.
Conclusion:
Atrial fibrillation is a frequent finding in PE, affecting more than 10% of patients. However, AF was not associated with a higher risk of in-hospital adverse outcomes and did not affect the prognostic performance of risk assessment strategies. Thus, our data support the use of risk stratification tools for patients with acute PE irrespective of the heart rhythm on admission
Defining Criteria for Guiding Cancer Patients to Find a Reputable Complementary Medicine Provider: Results of a Literature Review and a Consensus Procedure
Purpose: Even in cases of positive evidence for complementary medicine (CM) therapies, it is still difficult for cancer patients to identify reputable providers. The aim of this study was to develop and evaluate a criteria list to provide guidance to cancer patients seeking a reputable CM provider.
Methods: The design combined a literature review, an expert consensus procedure (n=15) and an assessment from three stakeholder perspectives (patients (n=18), CM providers (n=26) and oncology physicians (n=20)).
Results: A total of 30 existing CM criteria were extracted from the literature, and 12 more were added by the experts. The main challenge was to define criteria that could easily be applied by the patients. A final comprehensive list of 8 criteria guiding cancer patients to find a reputable CM provider was developed.
Conclusion: Health professionals and cancer information services might find the criteria list helpful when aiming to strengthen patients' awareness of quality-related factors associated with CM providers. The criteria developed might be helpful when standards are established for quality assurance in CM in oncology
Publisher Correction: Carbon dioxide sink in the Arctic Ocean from cross-shelf transport of dense Barents Sea water
In the version of this article initially published, author Cora Hörstmann was wrongly listed with a second affiliation with the Department of EcoscienceâApplied Marine Ecology and Modelling, Aarhus University rather than the Mediterranean Institute of Oceanography (MIO), Marseille, France. Furthermore, references 83â97, now found in the Supplementary Tables caption, were wrongly cited in the Data Availability section. The errors have been corrected in the HTML and PDF versions of the article
A vast icefish breeding colony discovered in the Antarctic
A breeding colony of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) of globally unprecedented
extent has been discovered in the southern Weddell Sea, Antarctica. The colony was estimated to cover
at least ïżœ240 km2 of the eastern flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests
per square meter, representing an estimated total of ïżœ60 million active nests and associated fish biomass of
>60,000 tonnes. The majority of nests were each occupied by 1 adult fish guarding 1,735 eggs (±433 SD). Bot-
tom water temperatures measured across the nesting colony were up to 2ïżœC warmer than the surrounding
bottom waters, indicating a spatial correlation between the modified Warm Deep Water (mWDW) upflow
onto the Weddell Shelf and the active nesting area. Historical and concurrently collected seal movement
data indicate that this concentrated fish biomass may be utilized by predators such as Weddell seals (Lep-
tonychotes weddellii, Lesson 1826). Numerous degraded fish carcasses within and near the nesting colony
suggest that, in death as well as life, these fish provide input for local food webs and influence local biogeo-
chemical processing. To our knowledge, the area surveyed harbors the most spatially expansive continuous
fish breeding colony discovered to date globally at any depth, as well as an exceptionally high Antarctic sea-
floor biomass. This discovery provides support for the establishment of a regional marine protected area in
the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources
(CCAMLR) umbrella
Characterization and reactivity of soot from fast pyrolysis of lignocellulosic compounds and monolignols
peer-reviewedThis study presents the effect of lignocellulosic compounds and monolignols on the yield, nanostructure and reactivity of soot generated at 1250âŻ
°
C in a drop tube furnace. The structure of soot was characterized by electron microscopy techniques, Raman spectroscopy and electron spin resonance spectroscopy. The CO2 reactivity of soot was investigated by thermogravimetric analysis. Soot from cellulose was more reactive than soot produced from extractives, lignin and monolignols. Soot reactivity was correlated with the separation distances between adjacent graphene layers, as measured using transmission electron microscopy. Particle size, free radical concentration, differences in a degree of curvature and multi-core structures influenced the soot reactivity less than the interlayer separation distances. Soot yield was correlated with the lignin content of the feedstock. The selection of the extraction solvent had a strong influence on the soot reactivity. The Soxhlet extraction of softwood and wheat straw lignin soot using methanol decreased the soot reactivity, whereas acetone extraction had only a modest effect
Offenlegung von CO2-Emissionen und Klimastrategien der CDAX-Unternehmen: Eine statistische Analyse erklÀrender Faktoren am Beispiel der CDP-Klimaberichterstattung
Im Rahmen des Beitrags untersuchen wir mithilfe des Regressionsansatzes, welchen Einfluss fĂŒr die gröĂten börsennotierten Unternehmen Deutschlands eine Auswahl unternehmensspezifischer Faktoren (UnternehmensgröĂe, ProfitabilitĂ€t, Sektorenzugehörigkeit, Beteiligungsstruktur, Status der Beantwortung, Vorjahresteilnahme) bei der Beantwortung folgender Fragestellungen besitzt: i) Wovon hĂ€ngt die Teilnahme an der freiwilligen Klimaberichterstattung an CDP ab? ii) Wovon hĂ€ngt die QualitĂ€t der freiwilligen Klimaberichterstattung an CDP ab? Der theoretische Teil der Untersuchung fokussiert die Befriedigung von InformationsbedĂŒrfnissen aller Anspruchsgruppen eines Unternehmens als Hauptmotiv fĂŒr die freiwillige Bereitstellung klimarelevanter Daten und Strategien. Im Zuge dessen wird erlĂ€utert, wie auf dieser Grundlage eine Vertragsbeziehung zwischen einem Unternehmen und seinen Anspruchsgruppen effizient gestaltet werden kann. Dabei wird die freiwillige Offenlegung klimarelevanter Daten und Strategien beispielhaft als die unternehmerische Teilnahme an der CDP-Klimaberichterstattung analysiert. Die empirischen Auswertungen im Anschluss an die Vorstellung der Datenbasis sowie die statistische HypothesenprĂŒfung zeigen insbesondere, dass die GröĂe eines Unternehmens und seine Beteiligungsstruktur einen signifikanten Einfluss auf die hier zentralen Fragestellungen haben