Background: To accurately measure seroprevalance in the population, boththe expected immune response as well as the assay performances have to be well characterised. Here, we describe the collection and initial characterisation of a blood and saliva biobank obtained after the initial peak of the SARS-CoV-2 pandemic in Switzerland.
Methods: Two laboratory ELISA assays measuring IgA & IgG (Euroimmun), and IgM & IgG (Epitope Diagnostics) were used to characterise the biobank collected from 349 re- and convalescent patients from the canton of Basel-Landschaft.
Findings: The antibody response in terms of recognized epitopes is diverse, especially in oligosymptomatic patients, while the average strength of the antibody response of the population does correlate with the severity of the disease at each time point.
Interpretation: The diverse immune response presents a challenge when conducting epidemiological studies as the used assays only detect 90% of the oligosymptomatic cases. This problem cannot be rectified by using more sensitive assays or lower cut-offs as they concomitantly reduce specificity. Funding Funding was obtained from the Amt fur Gesundheit of the canton Basel-Landschaft, Switzerland.
This paper stresses its base contribution on a new SIR-type model for COVID-19 including direct and fomite transmission as well as the effect of distinct household structures. To what extent increasing the physical-distancing-related contact radius and enhancing mass control (public curfew, lockdown, workplace clearance, and school closure) reduce the number of predicted active cases is studied via parameter estimation.
The maximum running speed of legged animals is one evident factor for
evolutionary selection---for predators and prey. Therefore, it has
been studied across the entire size range of animals, from the
smallest mites to the largest elephants, and even beyond to extinct
dinosaurs. A recent analysis of the relation between animal mass
(size) and maximum running speed showed that there seems to be an
optimal range of body masses in which the highest terrestrial running
speeds occur. However, the conclusion drawn from that
analysis---namely, that maximum speed is limited by the fatigue of
white muscle fibres in the acceleration of the body mass to some
theoretically possible maximum speed---was based on coarse reasoning
on metabolic grounds, which neglected important biomechanical factors
and basic muscle-metabolic parameters. Here, we propose a generic
biomechanical model to investigate the allometry of the maximum speed
of legged running. The model incorporates biomechanically important
concepts: the ground reaction force being counteracted by air drag,
the leg with its gearing of both a muscle into a leg length change and
the muscle into the ground reaction force, as well as the
maximum muscle contraction velocity, which includes muscle-tendon
dynamics, and the muscle inertia---with all of them scaling with body
mass. Put together, these concepts' characteristics and their
interactions provide a mechanistic explanation for the allometry of
maximum legged running speed. This accompanies the offering of an
explanation for the empirically found, overall maximum in speed: In
animals bigger than a cheetah or pronghorn, the time that any
leg-extending muscle needs to settle, starting from being isometric
at about midstance, at the concentric contraction speed required for
running at highest speeds becomes too long to be attainable within the
time period of a leg moving from midstance to lift-off. Based on our
biomechanical model we, thus, suggest considering the overall speed
maximum to indicate muscle inertia being functionally significant in
animal locomotion. Furthermore, the model renders possible insights
into biological design principles such as differences in the leg
concept between cats and spiders, and the relevance of multi-leg
(mammals: four, insects: six, spiders: eight) body designs and
emerging gaits. Moreover, we expose a completely new consideration
regarding the muscles' metabolic energy consumption, both during
acceleration to maximum speed and in steady-state locomotion.
An optimal control model of Aedes aegypti population dynamics concerning classification of indoor-outdoor life cycles is taken into account in this paper. A dengue epidemics measure, the basic mosquito offspring, is obtained from the well-known next-generation matrix. The number is used to analyse the stability of the mosquito-free equilibrium. This mosquito-free equilibrium describes a steady-state condition in the mosquito population dynamics where there are no mosquitoes. Comprehensive analysis on the existence and stability of the positive non-trivial equilibrium state is shown as well. Further work deals with designation of the control measures and numerical implementation of the optimal control model using various scenarios. We highlight those measures expressed as the semi-discrete mass profile of the Temephos spraying and the thermal fogging.
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