Search results

In this paper we analyze the effects of body shadowing in multiple-input-multiple-output (MIMO) channels used for personal area networks (PANs). We give physical reasoning to why PANs may experience two different types of shadowing, and to support our argument, we present results from a measurement campaign for three different PAN channels with human influence. The campaign is performed using diff

The inverse scattering problem on the half-axis for long range potentials is studied. It is shown that the solution of the inverse problem contains arbitrary real parameters iven if no bound states are present. Connections with the inverse problem on the whole axis are discussed.

Extraction and chromatographic separation of fat-soluble vitamins is a challenging task, due to the sensitivity of these compounds towards light, oxygen, heat and pH. In light of this, supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) are attractive techniques as they function at considerably milder conditions than conventional solvent-based analytical techniques. M

Från den 1 januari 2004 gäller en ny lag om etikprövning av forskning som avser människor. De viktigaste förändringarna från 2004 blir att en central och sex regionala nämnder för etikprövning inrättas som fristående myndigheter. Lagen har aktualiserats genom Sveriges undertecknande av Europarådets konvention om mänskliga rättigheter och biomedicin. Den omfattar forskning på levande personer, men

The addition of a carbon nutrient feed to a fed-batch cultivation is often not enough to obtain satisfactory growth and/or production. In some cases, an additional feed with for example supplementary amino acids or complex media is required. This work presents the development of feeding strategies where more than one feed is required and the knowledge of the growth requirements is low. Simulations

A new implantable electrocatalytic glucose sensor for subcutaneous glucose monitoring has been fabricated by immobilizing glucose oxidase on a chemically modified carbon fiber. The sensor was inserted subcutaneously on a male spraguely rat without any incision after dipping the microsensor in the rat's serum for 3 days. The so called "stained" microsensor, operated in the amperometric mode with an

X-linked lymphoproliferative disease (XLP) is a rare and severe immune deficiency, characterized by abnormal immune responses to the Epstein-Barr virus. Recently, the gene responsible for XLP, SH2D1A, has been identified and shown to code for a small cytoplasmic protein with an SH2 domain that interacts with SLAM and 2B4, two receptorial molecules involved in signal transduction in T and NK cells,

Biosensors, combining a selective biological recognition element and a sensitive transducer, are versatile analytical tools applied more and more in different fields, such as medicine, food quality and safety control, and environment pollution monitoring. They are expected to play an increasingly important role in the improvement of life quality. In this context, the present work covers recent app

Data erasure is considered an essential requirement for a practical optical time-domain memory, and it requires that the laser used have very good frequency stability. Such a laser is developed for this work, and data erasure is demonstrated with a sample of YSiO5:Eu3+ for write/rewrite pulse sequences of up to a duration of 100 μs. This is two orders of magnitude longer than had been achieved pre

During the last 5 years the potential for applications of semiconductor nanowires has grown rapidly via the development of methods for catalytically induced nanowire growth using the, so-called vapor-liquid-solid (VLS) growth mode. The VLS method offers a high degree of control of parameters such as position, diameter, length and composition, including the realization of atomically abrupt heterost

Horizontal gene transfer (HGT) is a sensational topic largely because its exploitation to date has been primarily journalistic. Properly packaged it captures the attention of a sensitized lay public and peps up circulation. HGT provides technical challenges for academic scientists as well as market analysts. For fans of science fiction as well as for environmental pessimists, HGT is the stuff of d

The development of underwater profiles and sand losses from the dune respectively the beach by various water level and wave conditions has been studied worldwide in large wave flumes since 1955. Virtually all major results collected over the last decades are documented and described in this paper. Moreover, to this overview results from the MAST III-SAFE experiments, carried out in the Grosser Wel

The reversibly photochromic pigment, phycochrome c, was extracted from the blue-green alga Nostoc muscorum strain A. Action spectra were determined for in vitro conversions of the pigment from the short wavelength to the long wavelength form and vice versa. The action peak for the absorbance decrease at 650 nm is at 630 nm. During this decrease there is only a slight increase of the absorbance in

Att förebygga ohälsa som följd av arbetsrelaterad stress är en utmaning även för läkarkåren. Stress kan utlösa flera allvarliga sjukdomar, bl a metabola rubbningar, sömnstörningar och CNS-dysfunktion.