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Minimization of the chromatic dispersion over a broad wavelength range in a single-mode optical fiber

The effective refractive index as a function of vacuum wavelength is approximated by Lagrange interpolation polynomials. The rms value of the chromatic dispersion is then calculated analytically. It is demonstrated that use of fourth-degree polynomials is far more efficient than the use of second-degree polynomials. The rms value of the chromatic dispersion over the wavelength range (1.25 mum, 1.6

Temporal Aspects of High-Intensity Laser-Matter Interactions

Popular Abstract in Swedish Utvecklingen av laserpulser med extremt hög intensitet har försett forskare med ett verktyg som gör det möjligt att studera vad som händer då dessa pulser växelverkar med olika slags materia. Då växelverkan sker med en gas kan till exempel ultrakorta pulser från ultraviolett till röntgenområdet genereras som övertoner till laserpulsen. Dessa övertoner kan göras kortare The availability of short-pulse, high-intensity lasers has opened doors to new areas in atomic and plasma physics. The short pulses (a few femtoseconds), that are available today, enable unprecedented temporal measurements, while the high peak power accessible (several terawatts) allows physicists to study the interaction between light and relativistic plasmas. The aim of this work was twofold: i)

Partial resistance to malonate-induced striatal cell death in transgenic mouse models of Huntington's disease is dependent on age and CAG repeat length

Transgenic Huntington's disease (HD) mice, expressing exon 1 of the HD gene with an expanded CAG repeat, are totally resistant to striatal lesion induced by excessive NMDA receptor activation. We now show that striatal lesions induced by the mitochondrial toxin malonate are reduced by 70-80% in transgenic HD mice compared with wild-type littermate controls. This occurred in 6- and 12-week-old HD m

ACTH lowers serum lipids in steroid-treated hyperlipemic patients with kidney disease

The mechanisms behind secondary hyperlipidemia in patients with various chronic inflammatory diseases are not known in detail. We have recently demonstrated that ACTH exerts strong hypolipidemic effects in healthy volunteers. To test the clinical relevance of this finding, we administrated ACTH during three weeks to nine hyperlipidemic steroid-treated patients with kidney disease. Before administr

Europeanisation, Territoriality and Political Time

In European governance, elements from different administrative and political cultures coalesce into one more complex framework. To capture some of the complexity, two central dimensions are addressed: territoriality and political time, understood as horizon, resource, and process. When investigating European governance the question of the institutional organization is important, since it relates t

The Swedish ankle arthroplasty register - An analysis of 531 arthroplasties between 1993 and 2005

Background Whether or not ankles can be replaced with reasonable safety has been the subject of debate. We present the results of a nationwide series of total ankle arthroplasties. Patients and methods All Swedish hospitals that implant or have implanted modern three-component ankle prostheses reported demographic data and date of index and revision surgery to a central register. After the data ha

Gamma-ray bursts and X-ray melting of material to form chondrules and planets

Chondrules are millimeter sized objects of spherical to irregular shape that constitute the major component of chondritic meteorites that originate in the region between Mars and Jupiter and which fall to Earth. They appear to have solidified rapidly from molten or partially molten drops. The heat source that melted the chondrules remains uncertain. The intense radiation from a gamma-ray burst (GR

Soil carbon sequestration in degraded semiarid agro-ecosystems - Perils and Potentials

The Kyoto Protocol opens new possibilities for using the biosphere as a carbon sink. Using agro-ecosystems as carbon sinks may be the most appropriate practice from both environmental and socioeconomic points of view. Degraded agro-ecosystems in Africa might benefit significantly from the improved land management that would be part of a carbon sequestration program. There are vast areas of these a

Upper Ordovician graptolites and biostratigraphy of the Rostanga 1 core, Scania, S. Sweden

drilling at Rostanga in 1997, referred to as Rostanga 1, penetrated a significant portion of the Upper Ordovician-Lower Silurian succession in this classical Lower Palaeozoic outcrop area in W-central Scania. In descending order the Upper Ordovician of the core embraces the following units (stratigraphic thickness in parenthesis): Lindegard Mudstone (27.8 m), Fjacka Shale (13.6 m), Mossen Formatio

Inhibition of dendropoiesis by tumor derived and purified prostate specific antigen

Purpose: Prostate specific antigen (PSA) is a serine protease produced by the prostate gland at high concentrations. Serum PSA may be significantly elevated in prostate cancer and benign prostatic diseases. It has recently become evident that, in addition to being a tissue and/or serum marker, PSA may also have biological effects. Despite the voluminous literature on this biomarker in the diagnosi

Arbetsmiljö vid termisk ogräsbekämpning

Rapporten behandlar arbetsmiljön vid termisk ogräsbekämpning. Metoden innebär att ogräset hettas upp med hjälp av gaslågor. Både stora fordonsburna och mindre handdrivna används. Det som från arbetsmiljösynpunkt är speciellt med metoden är de risker som är förknippade med gasolanvändningen. De allvarligaste problemen med de aggregat som studerats har varit heta och oskyddade plåtar, heta avgaser o

Solid-state single photon sources: light collection strategies

We examine the problem of efficiently collecting the photons produced by solid-state single photon sources. The extent of the problem is first established with the aid of simple physical concepts. Several approaches to improving the collection efficiency are then examined and are broadly categorized into two types. First are those based on cavity quantum dynamics, in which the pathways by which th

Passive sustained turning of the head induces asymmetric gain of the vestibulo-ocular reflex in healthy subjects

In order to test the hypothesis of an interaction between neck proprioception and the vestibulo-ocular reflex (VOR), we rotated 16 healthy subjects both facing forward and with their heads passively turned 70 degrees to either side. We found that gain tended to be lower when the subjects were rotated with their heads turned opposite to the direction of rotation compared to when they were rotated i

Partitioning of beta-mannanase and alpha-galactosidase from Aspergillus niger in Ucon/Reppal aqueous two-phase systems and using temperature-induced phase separation

Enzyme partitioning and recovery with a new aqueous two-phase system based on commercially available hydroxypropyl starch Reppal PES 200 and the thermo-separating polymer Ucon 50-HB-5100 was studied. Ucon is an ethylene oxide-propylene oxide random copolymer. A culture supernatant of Aspergillus niger containing extracellular beta-mannanase and alpha-galactosidase was partitioned in two steps. The