If images are undersampled during electronic recording and reproduction, regular patterns in the image may form interference patterns-aliases-with the mosaic of picture elements (pixels). Aliasing distorts visual information and is a serious technical problem. In a variety of animal eyes, images are also undersampled such that aliasing may occur. Nature's measures to reduce aliasing include (i) mo

We present a rate equation model for the TGF-beta pathway in endothelial cells together with novel measurements. This pathway plays a prominent role in inter- and intracellular communication and subversion can lead to cancer, fibrosis vascular disorders, and immune diseases. The model successfully describes the kinetics of experimental data and also correctly predicts the behavior in experiments w

Graptolites are uncommon in the Lower Visby Formation. Specimens derived from conodont residues are predominantly members of the long ranging genus Retiolites, with single specimens recorded of Paraplectograptus and Monograptus priodon. Only one graptolite, a specimen of Cyrtograptus bohemicus, has been recovered from the Upper Visby Formation. This is the only biostratigraphically important speci

Hyperhomocysteinemia is a risk factor for atherosclerosis and venous thrombosis, probably exerting its effects through endothelial function. Homocysteine levels are lowered by folate supplementation, and such treatment improves endothelial function. However, whether folate supplementation decreases vascular risk and improves survival is unknown. The aim of this study was to evaluate endothelial fu

High fat diets and obesity pose serious health problems, such as type II diabetes and cardiovascular disease. Impaired cognitive function is also associated with high fat intake. In this study, we show that just 4 weeks of feeding a diet rich in fat ad libitum decreased hippocampal neurogenesis in male, but not female, rats. There was no obesity, but male rats fed a diet rich in fat exhibited elev

Recent investigations have shown neuropeptide Y (NPY) to be present in the rabbit maxillary sinus, and NPY is known to be released upon sympathetic nerve stimulation. To study, in vivo, the effect on mucociliary activity and blood flow, NPY 1-36 and some of its analogues were injected intra-arterially. The effects of the Y1/Y2 agonist NPY 1-36 was compared with the ones of the Y2 agonist NPY 16-36

Aim: To update the first version of the European core curriculum to reflect many developments in radiotherapy and educational philosophy that have taken place in the interim period. Materials and methods: The first version of the European core curriculum was reviewed by the Steering Group together with current education programmes from the various member states and taking into account the developm

A global existence result for solutions u(t) of the differential equation x" + f(t, x) = p(t), t >= t(0) >= 1, that can be written as u(t) = P(t) + o(l) for all large t, where P"(t) = p(t), is established by means of the Schauder-Tikhonov theorem. It generalizes the recent work of Lipovan [On the asymptotic behaviour of the solutions to a class of second order nonlinear differential equations, Gla

The Black-Scholes formula is a well-known model for pricing and hedging derivative securities. It relies, however, on several highly questionable assumptions. This paper examines whether a neural network (MLP) can be used to find a call option pricing formula better corresponding to market prices and the properties of the underlying asset than the Black-Scholes formula' The neural network method i

An experimental investigation has been carried out to find the pressure difference of the process of steam condensation across the port to channel in plate heat exchangers. In the present study, low corrugation angle (30°) plates have been used for different number of channels, namely, 10 and 80. The process steam entered at 1 bar with a small degree of superheat. Water has been used as the cold f

Fluorescence recovery after photobleaching, FRAP, has been an established technique of quantifying the mobility of molecular species in cells and cell membranes for more than 30 years. However, under non-ideal experimental conditions the current methods of analysis still suffer from occasional problems, for example, when the signal to noise ratio is low, when there are temporal fluctuations in the

In recent years, sleep medicine has evolved into a full-grown discipline, featuring a multidisciplinary approach to diagnosis and treatment of patients with sleep disorders. Sleep medicine cuts across the boundaries of different conventional disciplines and is therefore open to medical and non-medical professionals with different specialty backgrounds. The aim of the current paper is to introduce

It has been shown, by imaging gold (200) planes, that it is possible to achieve better than 0.20-nm structural resolution in cryo-transmission electron microscopy (cryo-TEM). This has been done using commercially available cryo equipment and using a 300-kV field emission gun (FEG) TEM. The images of 15-nm gold particles embedded in amorphous frozen water clearly show the (111) planes (separated by

BACKGROUND: Results from previous studies on the effect of nitrous oxide (N2O) on the cerebral circulation are conflicting. Early reports claim N2O to have no effect whereas recent findings demonstrate a cerebral cortical vasodilatation during N2O inhalation, but the regional cerebral blood flow (CBF) in the subcortical structures is unknown. METHODS: Regional CBF was measured three-dimensionally

Resonant core spectroscopies are applied to a study of the excited electron transfer dynamics on a low-femtosecond time scale in systems of aromatic molecules (isonicotinic acid and bi-isonicotinic acid) adsorbed on a rutile TiO2(110) semiconductor surface. Depending on which adsorbate state is excited, the electron is either localized on the adsorbate in an excitonic effect, or delocalizes rapidl

Stochastic leaky integrate-and-fire (LIF) neuronal models are common theoretical tools for studying properties of real neuronal systems. Experimental data of frequently sampled membrane potential measurements between spikes show that the assumption of constant parameter values is not realistic and that some (random) fluctuations are occurring. In this article, we extend the stochastic LIF model, a

The adsorption of Ga(III) at the water-alpha-FeOOH (goethite) interface has been investigated by means of quantitative adsorption experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy, and surface complexation modeling. Under the conditions studied, pH range 3-11 and surface coverages of 0.9-3.2 mu mol/m(2), Ga(III) was found to adsorb strongly to alpha-FeOOH, and the surface

The group B streptococcus (GBS) is the most important cause of life-threatening bacterial infections in newborn infants. Protective immunity to GBS infection is elicited by several surface proteins, one of which, the beta protein, is known to bind human IgA-Fc. Here, we show that the beta protein also binds human factor H (FH), a negative regulator of complement activation. Absorption experiments

Longitudinal data are presented on a boy between the ages ofthree and eight. At age three he received a diagnosis oflanguage impairment and at age six a diagnosis of high-functioning autism. Results are presented from extensive assessments at four points in time, including interviews with his mother and teachers. The results indicate that the boy s core problem was poor language comprehension, esp