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This study analyzes the intergenerational effects of late child bearing on offspring’s adult longevity in a population in Utah (USA) that does not display evidence of parity-specific birth control – a so-called natural fertility population. Studies have found that for women who experience late menopause and prolonged reproduction, aging is postponed and longevity is increased. This is believed to
Theoretical models and experiments suggest that the transport of suspended particles in microfluidics-based sorting devices can be modeled by a two-dimensional effective advection-diffusion process characterized by constant average velocity, $$\mathbf {W}$$W, and a typically anisotropic dispersion tensor, $$\mathbb {D}$$D, whose principal axes are slanted with respect to the direction of the effec
A survey of techniques to solve ATS + SA + Q = 0 is presented, and nine algorithms are coded and tested on a batch of examples. Which algorithm to be recommended depends mainly on the order of the system.
Inversion of a linear dynamical system is shown to be an operator equivalence to the well-known matrix lemma: (D + CLB)−1 = [D−1 − D−1C(L−1 + BD−1C)−1BD−1]
The linear filtering, prediction and smoothing problems as well as the linear quadratic control problems can very generally be formulated as operator equations using basic linear algebra.The equations are of Fredholm type II, and they are difficult to solve directly.It is shown how the operator can be factorized into two Volterra operators using a matrix Riccati equation. Recursive solution of the
The 1-locus incompatibility system that is usually assumed to be present in the red clover is investigated. The allele fluctuations from one generation to the other are demonstrated. A mathematical state model is deduced for arbitrary numbers of alleles in the population, and its steady-state behaviour and stability are discussed. The eigenvalues of the linearized models as well as simulations sho
The random effects in tracer kinetics and cell cycle kinetics are usually described by the particle residence time. An analytical framework is developed, and the importance of the statistical independence of the residence times is emphasized.
The Grodsky packet storage model describes many features of insulin release, but at present more or less arbitrary simplifications are necessary. The consequences of various simplifications are discussed, especially with regard to identification of parameters thought to be of importance for glucose tolerance. In particular, the insulin release dynamics of the ordinary intravenous glucose tolerance
The overdamped dynamics of particles dragged by a parallel flow in a straight micro-channel in the presence of a transverse acoustophoretic force is investigated. Analytical solutions are presented in the case of plug, shear, or Poiseuille flow velocity profile. Two regimes of particle dynamics are observed, namely an early regime dominated by the local stream-wise velocity and a later regime gove
Deterministic lateral displacement provides a novel and efficient technique for sorting micrometer-sized particles based on particle size. It is grounded on the principle that the paths associated with particles of different diameters, entrained in flow streaming through a periodic lattice of obstacles, are characterized by different deflection angles with respect to the average direction of the c
We investigate the mixing layer thickness, δ(ξ), along the streamwise coordinate ξ of a straight channel fed with alternating streams of segregated solutes. We show the occurence of convection-enhanced mixing regimes downsteram the channel: i) an early-mixing regime, δ(ξ) ∼ξ 1/3 resembling the classical Lèvêque scaling of the thermal boundary layer, ii) an intermediate anomalous regime δ(ξ)∼ξ 3/5,
This article develops the theory of laminar dispersion in finite-length channel flows at high Péclet numbers, completing the classical Taylor-Aris theory which applies for long-term, long-distance properties. It is shown, by means of scaling analysis and invariant reformulation of the moment equations, that solute dispersion in finite length channels is characterized by the occurrence of a new reg
This article develops the theoretical analysis of transport and dispersion phenomena in wide-bore chromatography at values of the Peclet number Pe beyond the upper bound of validity of the Taylor-Aris theory. It is shown that for Poiseuille flows in cylindrical capillaries the average residence time grows logarithmically with the Peclet number, while the variance of the outlet chromatogram scales
This article analyses stationary scalar mixing downstream an open flow Couette device operating in the creeping flow regime. The device consists of two coaxial cylinders of finite length Lz, and radii κR and R (<1), which can rotate independently. At relatively large values of the aspect ratioα = Lz/R 1, and of the Pclet number Pe, the stationary response of the system can be accurately described
