We analyze numerically a new ratchet system: a liquid drop is sitting on a heterogeneous ratchet-structured solid plate. The coated plate is subject to a lateral harmonic oscillation. The systematic investigation performed in the frame of a phase field model shows the possibility of realizing a long-distance net-driven motion for isolated domains of the forcing parameters.
View Article and Find Full Text PDFWe study epidemic spreading in complex networks by a multiple random walker approach. Each walker performs an independent simple Markovian random walk on a complex undirected (ergodic) random graph where we focus on the Barabási-Albert (BA), Erdös-Rényi (ER), and Watts-Strogatz (WS) types. Both walkers and nodes can be either susceptible (S) or infected and infectious (I), representing their state of health.
View Article and Find Full Text PDFWe study an epidemic model for a constant population by taking into account four compartments of the individuals characterizing their states of health. Each individual is in one of the following compartments: susceptible S; incubated, i.e.
View Article and Find Full Text PDFAims: Studies assessing transfemoral transcatheter aortic valve implantation (TF-TAVI) showed lower rates of in-hospital mortality at high-volume hospitals and minimum caseloads were recommended to assure quality standards.
Methods And Results: All patients in the German mandatory quality assurance registry with elective or urgent TF-TAVI procedures in 2018 and 2019 at 81 and 82 hospitals, respectively, were analysed. Observed in-hospital mortality was adjusted to expected mortality by the German AKL-KATH score (O/E) as well as by the EuroScore II (O/E2).
We introduce a compartment model with memory for the dynamics of epidemic spreading in a constant population of individuals. Each individual is in one of the states S=susceptible, I=infected, or R=recovered (SIR model). In state R an individual is assumed to stay immune within a finite-time interval.
View Article and Find Full Text PDFWe analyze the dynamics of a population of independent random walkers on a graph and develop a simple model of epidemic spreading. We assume that each walker visits independently the nodes of a finite ergodic graph in a discrete-time Markovian walk governed by his specific transition matrix. With this assumption, we first derive an upper bound for the reproduction numbers.
View Article and Find Full Text PDFThe linear evolution of the incompressible Rayleigh-Taylor instability for the interface between an elastic-plastic slab medium and a lighter semi-infinite ideal fluid beneath the slab is developed for the case in which slab is attached to a rigid wall at the top surface. The theory yields the maps for the stability in the space determined by the initial perturbation amplitude and wavelength, as well as for the transition boundary from the elastic to the plastic regimes for arbitrary thicknesses of the slab and density contrasts between the media. In particular, an approximate but very accurate scaling law is found for the minimum initial perturbation amplitude required for instability and for the corresponding perturbation wavelength at which it occurs.
View Article and Find Full Text PDFBackground: Tick-borne encephalitis (TBE) is the most important tick-borne viral disease in Eurasia and causes disease in humans and in a number of animals, among them dogs and horses. There is still no good correlation between tick numbers, weather conditions and human cases. There is the hypothesis that co-feeding due to simultaneous occurrence of larvae and nymphs may be a factor for the increased transmission of the virus in nature and for human disease.
View Article and Find Full Text PDFBackground: Tick-borne encephalitis virus (TBEV) is considered to be the medically most important arthropod-borne virus in Europe. The symptoms of an infection range from subclinical to mild flu-like disease to lethal encephalitis. The exact determinants of disease severity are not known; however, the virulence of the strain as well as the immune status of the host are thought to be important factors for the outcome of the infection.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
June 2020
Introducing an extension of a recently derived dimension-reduced model for an infinitely deep inviscid and irrotational layer, a two-layer system is examined in the present paper. A second thin viscous layer is added on top of the original one-layer system. The set-up is a combination of a long-wave approximation (upper layer) and a deep-water approximation (lower layer).
View Article and Find Full Text PDFTicks are important parasites from economic and public health points of view because of their ability to reduce farm animals' productivity and transmit zoonotic diseases. We conducted this cross-sectional study between January and March 2016 and between March and April 2017 to identify tick species in West Darfur, Al-Jazeera, and the River Nile states in the Sudan and to investigate whether these ticks carry Rickettsia spp. and Crimean-Congo hemorrhagic fever (CCHF) virus.
View Article and Find Full Text PDFAn evidence for Crimean-Congo hemorrhagic fever virus (CCHFV) was found in Hyalomma impeltatum ticks collected from sheep in North Kordofan in the Sudan. Based on sequencing of the partial segment S, the detected virus belongs to lineage I with closest similarity to CCHFV strains from Senegal. So far, this lineage is unknown in the Sudan.
View Article and Find Full Text PDFTick-borne encephalitis (TBE) is the most important tick-borne arboviral disease in Europe. Presently, the main endemic regions in Germany are located in the southern half of the country. Although recently, sporadic human TBE cases were reported outside of these known endemic regions.
View Article and Find Full Text PDFBackground: Hyalomma marginatum and Hyalomma rufipes are two-host tick species, which are mainly distributed in southern Europe, Africa and middle-eastern Asia. They are well-known vectors of Crimean Congo hemorrhagic fever (CCHF) virus and other viruses as well as Rickettsia aeschlimannii. In recent years, these tick species have been found sporadically in Germany, but they do not belong to the autochthonous tick fauna in Germany.
View Article and Find Full Text PDFBackground: Tick-borne encephalitis (TBE) virus is transmitted to humans and animals through tick bites and is thought to circulate in very strictly defined natural environments called natural foci. The most common tick serving as a vector for the TBE virus in central Europe is Ixodes ricinus; it is rarely found in other tick species and in Dermacentor reticulatus it has, so far, only been reported in Poland.
Methods: Between autumn 2016 and spring 2018 ticks were collected by the flagging method in a new TBE focus in the district of northern Saxony, Germany, outside the known risk areas as defined by the national Robert Koch Institute.
The Danish island of Bornholm in the Baltic Sea has been known as a tick-borne encephalitis (TBE) natural focus for more than 60 years. TBE in humans is diagnosed on a regular basis either in inhabitants or tourists of the island. Other areas in Denmark have been suggested as possible risk areas of TBE.
View Article and Find Full Text PDFWe investigate numerically the role of the correlation length in drop behavior on noisy surfaces. To this aim, a phase field tool has been used. Theoretical results are confirmed by experiments of distilled water drops sitting on stainless steel and silicon surfaces textured by laser-induced periodic self-organized structures: an increase of the noise amplitude results in an amplification of the original behavior (i.
View Article and Find Full Text PDFObjective: Tick-borne encephalitis (TBE) caused by the tick-borne encephalitis virus (TBEV) is the most important tick-borne arboviral disease in Europe and Asia. The Upper Rhine Valley is thought to be the very western border of TBEV distribution in Europe. The aim of our study was to identify natural foci and isolate TBEV from ticks, to determine the prevalence of TBEV in local tick populations and to study the phylogenetic relatedness of circulating TBEV strains in this region.
View Article and Find Full Text PDFIn May 2016, two cases of tick-borne encephalitis (TBE) were confirmed by serology (positive IgM and IgG antibodies against TBE virus (TBEV) in serum), with a possible link to raw milk and cheese from a goat farm in a region in Baden-Württemberg, Germany not previously known as TBE-endemic. The outbreak investigation identified 32 consumers of goat dairy products (29 consumers, one farm employee, two owners) of whom none had IgM antibodies against TBEV 3-8 weeks after consumption. Of the 27 notified TBE cases in the State, none reported consumption of raw goat milk or cheese from the suspected farm.
View Article and Find Full Text PDFAims: Randomised trials comparing transcatheter aortic valve replacement (TAVR) with surgical aortic valve replacement (SAVR) have included mainly elderly patients >80 years. The authors investigated comparative in-hospital outcomes of younger patients <75 years undergoing transfemoral (TF) TAVR or isolated SAVR.
Methods And Results: A total of 6,972 patients aged 65-74 years undergoing TF-TAVR or SAVR between 2013 and 2014 were identified from the observational German Quality Assurance Registry on Aortic Valve Replacement (AQUA), which comprises all TAVR and SAVR procedures performed in Germany.
In 2015, 0.02% nymphs displayed anomalies (ectromely) out of the 6744 collected ticks as part of a tick-borne encephalitis program in Germany. In 2016, questing Ixodes ricinus (n = 14,527) and Ixodes inopinatus (n = 75) ticks were collected by flagging as part of a tick-borne encephalitis program in Germany, Slovakia and Denmark.
View Article and Find Full Text PDFAims: Previous studies have shown lower rates of in-hospital complications and mortality for patients undergoing surgical aortic valve replacement (sAVR) in high-volume compared with lower-volume hospitals. It was the aim of our study to analyse whether there is a similar volume-outcome relationship for transcatheter aortic valve implantation (TAVI), which is increasingly used in clinical practice.
Methods And Results: We analysed all patients with non-emergent transfemoral (TF) TAVI procedures performed in 2014 in 87 German hospitals.
Aims: Recent randomized trials have documented the superiority of TAVR-particularly via transfemoral access-over SAVR in patients with severe aortic stenosis considered to have a high or intermediate operative risk of death. We sought to assess in-hospital outcomes of patients with severe aortic stenosis and a low risk of operative mortality undergoing routine surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).
Methods And Results: We performed a propensity-score matched comparison of all patients undergoing first-time treatment by SAVR or transfemoral TAVR (TF-TAVR) in 2014 in Germany who had a logistic EuroSCORE (logES) ≤ 10%, considered to reflect low surgical risk.
We report here the complete genome sequence (GenBank accession no. KX268728) of tick-borne encephalitis strain HB171/11, isolated from an Ixodes ricinus tick from a natural focus where human neurological disease is rare. The strain shows unique characteristics in neuroinvasiveness and neurovirulence.
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