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This paper describes an acoustic method for inducing rotating vortex flows in microchannels. An ultrasonic crystal is used to create an acoustic standing wave field in the channel and thus induce a Rayleigh flow transverse to the laminar flow in the channel. Mixing in microchannels is strictly diffusion-limited because of the laminar flow, a transverse flow will greatly enhance mixing of the react
Gas exchange in fruits, in particular oxygen transport in apples, was studied non-intrusively using wavelength modulation diode laser absorption spectroscopy at about 761 run, applied to the strongly scattering intact fruit structure. The applicability of the technique was demonstrated by studies of the influence of the skin to regulate the internal oxygen balance and of cling film in modifying it
Early age at menarche is a risk factor for breast cancer. A previous study reported a significant positive association between the CYP3A4*1B variant allele and early puberty. We investigated whether polymorphisms of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes predict the age at onset of menarche. Five hundred eighty-three nulliparous women between ages 17 and 35, of various ethnic backgrounds, com
A widely used estimate claims that one per thousand individuals is deaf, but few recent studies exist on the actual prevalence. The aim of this study was to investigate the prevalence of deaf people, defined as deaf individuals who use sign language as their main mode of communication, in the county of Scania, Sweden. To achieve high validity, data were collected from a large variety of sources in
AIMS: To study the pharmacological and mechanical properties of newly developed detrusor muscle after subtotal cystectomy, to explore if the regenerated detrusor has characteristics similar to the normal bladder base, from which it regenerated, or to the normal bladder body which it replaces. METHODS: Partial cystectomy was performed in female rats. Fifteen weeks later, detrusor strips were cut fr
Exposure of the skin to certain phenols or catechols such as 4-tert-butylphenol (TBP) and 4-tert-butylcatechol (TBC) may cause leukoderma. These substances are used in the polymer industry and numerous cases have been reported. Several theories of the mechanism for chemical leukoderma have been suggested. In the present study, TBP and TBC are shown to be oxidised by tyrosinase. The oxidation of TB
Objective: We examined pituitary tumor volumes in patients treated with pegvisomant for 18 months or longer and in whom the tumors were monitored for at least 3 years. We present details on 9 of 304 patients in clinical trials with pegvisomant who experienced tumor growth within the first year of treatment. Method: Magnetic reonance images prior to start of pegvisomant and at last follow-up were e
The aim of this article is to introduce an integrative and more comprehensive approach to understanding and measuring perceived housing in old age. First, four conceptual domains of subjective housing were introduced, based on the assumption that each of the domains brings a unique perspective to the understanding of perceived housing: housing satisfaction, usability in the home, meaning of home a
Objective: to illuminate the experiences of women who have given birth at home. Methods: a descriptive design with a qualitative approach based on interviews with 12 women. The text was analysed using a phenomenological-hermeneutic method. Findings: giving birth at home meant preserved authority and autonomy whereby the women themselves ruled the situation. The women's experiences of giving birth
The lifetimes of three short-lived levels belonging to the 4f(9) 6p configuration and of two long-lived levels of the 4f(9) 5d configuration of Dy iii have been measured for the first time using time-resolved laser-induced fluorescence techniques. They are in good agreement with theoretical values calculated within the framework of a pseudo-relativistic configuration interaction approximation. Usi
In this study a plate-fin type Compact Heat Exchanger (CHE) is considered for optimization. The optimization method uses a Genetic Algorithm (GA) to search, combine and optimize structure sizes of the CHE. The minimum total volume or/and total annual cost of the CHE are taken as objective functions in the GA, respectively. The geometries of the fins are fixed while three shape parameters are varie
The admission control mechanism is an important part of many communication systems. In this paper we investigate load control mechanisms for server systems, that is systems that may be modelled as queueing systems. We show how control theory can be used when designing controllers for a G/G/1-system. We design a PI-controller for the system and compare the steady-state and transient behavior of thi
Every tripotent e of a generalized Jordan triple system J of order I uniquely defines a decomposition into the direct sum of l(2) + 2l components. This decomposition generalizes the known Peirce decomposition of a Jordan triple system and of a generalized Jordan triple system of second order, and is the first step in determining the structure of a generalized Jordan triple system in terms of the t
The stability of a colloidal solution consisting of a mixture of charged spherical aggregates and polyampholytes is investigated by means of Monte Carlo simulations. The double-layer repulsion between the charged macroions is reduced upon addition of neutral polyampholyte and for sufficiently highly charged colloids it is converted into a net attractive interaction. Attractive interactions can als
Female moths generally use pheromones to attract males. Normally, all females in a population produce a specific chemical blend with only a limited variance, and the local males are highly attracted to this blend. To better understand the direct and indirect selective forces acting on this communication system, where, unusually, it is the reproductively limited sex that signals for matings, a popu
We examine the dynamics of two bright solitary waves with a negative nonlinear term. The observed repulsion between two solitary waves-when these are in an antisymmetric combination-is attributed to conservation laws. Slight breaking of parity, in combination with weak relaxation of energy, leads the two solitary waves to merge. The effective repulsion between solitary waves requires certain nearl
Developmental instability and fluctuating asymmetry (FA) describe the inability of organisms to correct for random accidents under development and has become a major but controversial topic in evolutionary biology. Theoretical models predict that the level of FA should increase as a result of inbreeding, but empirical results are ambiguous. Moreover, the relationship between fitness and FA is stil
