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A probabilistic model for the 5k+1 problem and related maps

We construct a probabilistic model which “mimics” the behaviour of a certain number-theoretical algorithm. This model involves study of a binary tree with randomly labelled edges, such that the labels have different distributions, depending on their directions. A number of properties of this tree are rigorously studied. As an application, this study could suggest what one could expect in the origi

A remote sensing-based primary production model for grassland biomes

That data from polar orbiting satellites have detected a widespread increase in photosynthetic activity over the last 20 years in the grasslands of the Sahel is justifies investigating its role in the tropical carbon cycle. But this task is undermined because ground data that are generally used to support the use of primary production models elsewhere are lacking. In this paper, we profile a Light

Is there a need for rescreening of patients treated for genital chlamydial infections?

The present communication reviews reasons to perform rescreening of chlamydia-infected persons. It brings up difficulties to differentiate between relapse and reinfection. Studies on follow-up of chlamydia-positive cases after therapy are reviewed. It also highlights reasons for therapeutic failure, like compliance, pharmacological factors, including poor bioavailability, wrong dose regimens, lack

Monolithic Integrated Oscillators - Phase Noise Analysis and Inductor Modeling

This doctoral dissertation studies voltage controlled oscillators (VCOs) that operate at low supply voltages. Due to smaller transistor sizes and lower supply voltage ratings with every new CMOS technology, voltage headroom is diminishing. Therefore, new ways to build VCOs and quadrature VCOs (QVCOs) have been sought to overcome this smaller headroom, while still maintaining the high performance o

The use of implantable cardioverter defibrillators in Iceland: a retrospective population based study

BACKGROUND: Indications for implantable cardioverter defibrillator (ICD) implantation have expanded considerably in recent years, resulting in steadily growing numbers of ICD recipients worldwide. The aim of this study was to review the overall experience with ICDs in Iceland. METHODS: This was a retrospective single centre study set at the University Hospital in Iceland. Data on all ICD implantat

The structure of sitting-atop complexes of metalloporphyrins studied by theoretical methods

The metallation of tetrapyrroles is believed to proceed via a sitting-atop (SAT) complex, in which some of the pyrrole nitrogen atoms are still protonated and the metal ion resides above the ring plane. No crystal structure of such a complex has been presented, but NMR and extended X-ray absorption fine structure (EXAFS) data has been reported for Cu2+ in acetonitrile. We have used density functio

Respiratory symptoms and lung function in 30-year-old individuals with alpha-1-antitrypsin deficiency.

Introduction: Individuals with severe alpha-1-antitrypsin (AAT) deficiency have a well-known risk of developing emphysema but it is not known at which age the first symptoms occur and lung function declines. The aim of this study was to examine the prevalence of smoking, respiratory symptoms and lung function at the age of 30 in AAT-deficient individuals (PiZ and PiSZ) identified by neonatal scree

Multiplication of electronic excitations and prospects for increasing scintillation efficiency in wide-gap crystals

A comparative analysis of the electron-hole (e-h) excitation mechanism of impurity luminescence has been performed for wide-gap oxides (WGO) and alkali halides crystals (AHC). A low quantum yield of scintillation in WGO with respect to that in AHC is connected with the high value of the average energy needed for the creation of an e-h pair in WGO. In AHC and many WGO, the width of a valence band E

Anatomical and physiological foundations of cerebellar information processing

A coordinated movement is easy to recognize, but we know little about how it is achieved. In search of the neural basis of coordination, we present a model of spinocerebellar interactions in which the structure-functional organizing principle is a division of the cerebellum into discrete microcomplexes. Each microcomplex is the recipient of a specific motor error signal-that is, a signal that conv

Preparation and characterisation of aggregating comblike poly(propylene oxide)

Poly(propylene oxide)s with a comblike architecture were prepared by using an ethylene-vinyl alcohol copolymer as a macroinitiator for anionic graft polymerisation of propylene oxide. The densely grafted polymers were subsequently modified by capping the terminal hydroxyl groups with hexadecanoyl chloride to produce aggregating polymers. Dilute solution viscometry showed that the hydroxyl and hexa

The adsorption of iron phthalocyanine on graphite: A scanning tunnelling microscopy study

Different adsorption phases of iron phthalocyanine (FePc) on highly oriented pyrolitic graphite (HOPG) have been characterized by scanning tunnelling microscopy (STM). Evaporation of FePc onto the graphite (000 1) surface, kept at room temperature. results in the formation of three-dimensional molecular islands. After annealing to 400 degrees C different two-dimensional features Lire identified. d

Jejunoileal bypass changes the duodenal cholecystokinin and somatostatin cell density

Background: In obese patients, jejunoileal bypass (JIB) has been used to induce weight reduction. Changes in the neuroendocrine system may be affected by the JIB-operation, because the proximal small intestinal mucosa has a rich supply of endocrine cells and peptidergic nerves. Materials and Methods: In 37 obese patients operated with JIB 1-30 years ago, small intestinal biopsies were taken at the

Self-doubt: Why we are not identical to things of any kind

There are two fundamental aspects of the notion of a self: (i) it is the owner of one's experiences, that to which one's experiences are properly attributed, and (ii) it perceives itself. (ii) is a condition on the self's being capable of attributing experiences to itself or being introspectively aware of its experiences, which constitutes a third, higher-order aspect of the self. I claim that it