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Tyrosinase-mediated formation of a reactive quinone from the depigmenting agents, 4-tert-butylphenol and 4-tert-butylcatechol

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

Follow-up of pituitary tumor volume in patients with acromegaly treated with pegvisomant in clinical trials

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

Homeward bound: Introducing a four-domain model of perceived housing in very old age

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

A qualitative study of women's experiences of home birth in Sweden.

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

Experimental and theoretical studies of DyIII: radiative lifetimes and oscillator strengths of astrophysical interest

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

Optimization of Compact Heat Exchangers by a Genetic Algorithm

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

Control theoretic modelling and design of admission control mechanisms for server systems

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

The Peirce decomposition for generalized Jordan triple systems of finite order

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

Modulation of colloidal forces with polyampholytes

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

Direct and indirect selection in moth pheromone evolution: population genetical simulations of asymmetric sexual interactions

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

Bright solitary waves in a Bose-Einstein condensate and their interactions

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

The effect of inbreeding on fluctuating asymmetry in Scabiosa canescens (Dipsacaceae)

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

A simple method for reconstructing a high-quality NDVI time-series data set based on the Savitzky-Golay filter

Although the Normalized Difference Vegetation Index (NDVI) time-series data, derived from NOAA/AVFIRR, SPOT/VEGETATION, TERRA or AQUA/MODIS, has been successfully used in research regarding global environmental change, residual noise in the NDVI time-series data, even after applying strict pre-processing, impedes further analysis and risks generating erroneous results. Based on the assumptions tha

BCR/ABL-negative chronic myeloid leukemia with ETV6/ABL fusion

A BCR/ABL-negative chronic myeloid leukemia (CML) with t(12;14) (p12;q11-13) as the sole chromosomal abnormality was investigated by fluorescence in situ hybridization (FISH), which disclosed a cryptic insertion of ETV6 (previously called TEL), located at 12p12, into ABL at chromosome band 9q34. ETV6/ABL fusion was confirmed by RT-PCR, revealing that the first five exons of ETV6 were fused in fram

Doppler-shift approximations of encountered wave statistics

In this paper the joint density of waveheight and half-wavelength is considered for waves observed at a fixed time point and encountering waves that are overtaking a ship from behind. The densities for these two cases are related by a Doppler shift, expressed in terms of the relative velocity of the waves and the ship. Based on this observation, an approximation of the encountered density is propo

Polyethylene wear and synovitis in total hip arthroplasty: a sonographic study of 48 hips

Forty-six patients (48 hips), operated on with cemented total hip arthroplasty (THA) because of arthrosis, were examined radiographically and sonographically at 10-year follow-up. Polyethylene wear of acetabular cups was measured on conventional non-weight-bearing pelvic radiographs, and the volume of polyethylene debris was calculated. Radiographic signs of loosening were identified. The capsular

Characteristics and origin of lowermost stratospheric aerosol at northern midlatitudes under volcanically quiescent conditions based on CARIBIC observations

Characteristics and origin of the aerosol in the lowermost stratosphere at northern midlatitudes were studied using measurements from a passenger aircraft ( Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container, or CARIBIC). Aerosol samples were collected during 60 intercontinental flights during 1999 - 2002 and analyzed for elemental composition with particle