Sökresultat

Filtyp

Din sökning på "*" gav 336377 sökträffar

On the complexity of some cryptographic problems based on the general decoding problem

A new probabilistic algorithm for decoding one received word from a set of many given received words, into a codeword such that the Hamming distance between the received word and the codeword is at most t, is proposed. The new algorithm is applicable to several cryptographic problems, such as the Stern identification scheme, the McEliece public-key cryptosystem, and in correlation attacks on strea

The enigma of increased non-cancer mortality after weight loss in healthy men who are overweight or obese.

Objective. To study effects on non-cancer mortality of observational weight loss in middle-aged men stratified for body mass index (BMI), taking a wide range of possible confounders into account. Design. Prospective, population based study. Setting. Male population of Malmö, Sweden. Participants. In all 5722 men were screened twice with a mean time interval of 6 years in Malmö, southern Sweden.

The Influence of SO2 and H2SO4 Impregnation of Willow Prior to Steam Pretreatment

In this investigation steam pretreatment of willow with the addition of SO2 or H2SO4 was studied, the aim being to recover both the cellulose and the hemicellulose fr actions. The willow was steamed (1 bar saturated steam) prior to impregnation with 0-3% H2SO4 or 1% SO2 (w/w substrate). The pretreatment experiments were performed at temperatures in the range 160-230 degrees C for 10 min. The highe

Dyskinesias following neural transplantation in Parkinson's disease.

Severe dyskinesias during the 'off' phases (periods of increased Parkinson's disease (PD) disability) have been observed following intrastriatal transplantation of human embryonic mesencephalic tissue. Here we retrospectively analyzed 14 patients who were followed for up to 11 years after grafting, and found that dyskinesias (abnormal involuntary movements and postures) increased during postoperat

Measurement of lung density by x-ray computed tomography. Relation to lung mechanics in workers exposed to asbestos cement

We measured lung density by means of x-ray computed tomography and lung mechanics in 33 workers exposed to asbestos cement and in 39 normal subjects. The exposed group showed evidence of lung fibrosis with reduced static lung volumes and lung compliance, although only three subjects had signs of interstitial fibrosis at standard chest radiography. Lung density was significantly increased in the ex

Volume rendering compared with maximum intensity projection for magnetic resonance angiography measurements of the abdominal aorta

Purpose: To compare the volume rendering technique (VRT) with maximum intensity projection (MIP) for aortic diameter measurements in MR angiography (MRA) data sets. Material and Methods: Existing contrast-enhanced 3-dimensional MRA and digital subtraction angiography (DSA) data sets from 20 patients were analyzed. In each MRA data set, two aortic diameters were measured using MIP and VRT. Agreemen

A novel diffusible substance can overcome the apparent AbrB repression of the Bacillus subtilis fatR promoter

In this work we present evidence for a novel diffusible extracellular factor that modulates gene expression in Bacillus subtilis. The factor was found when studying the regulation of the fatR-cyp102A3 operon. In a Spo0A(-) mutant expression of the fatR-cyp102A3 operon was almost abolished. The fatR-cyp102A3 expression defect of a Spo0A(-) mutant could be overcome either by a mutation in the abrB g

Development of antioxidant enzymes in rat brain and in reaggregation culture of fetal brain cells

The development of antioxidant enzymes in rat brain and reaggregation cultures of fetal brain cells was studied from embryonic day 15 to postnatal day 45. Both in vivo and in culture, the copper-zinc superoxide dismutase activity first increased and then decreased with age, whereas the manganese superoxide dismutase activity increased throughout the period. Catalase showed a maximum activity at da

Fluorescence study on the size and shape of sodium dodecyl sulphate-aluminium salt micelles

The application of time-resolved fluorescence methods to study the aggregation behavior in aqueous solution of anionic surfactant sodium dodecyl sulphate (SDS) in presence of trivalent counterions (Al3+) was investigated. Addition of small amounts of aluminum salt to dilute micellar solutions (< 10 wt.% SDS) resulted in isotropic fluid solutions, but for a molar ratio [SDS]/[Al(NO3)(3)] lower than

Comparison of glutathione peroxidase activity, and of total and soluble selenium content in two muscles from chicken, turkey, duck, ostrich and lamb

Glutathione peroxidase activity (GSHPx), total and soluble selenium in two muscles from five species were compared (chicken, duck, turkey, ostrich and lamb). The highest GSHPx activity, found in duck muscles (4.8 U/g; 3.0 U/g), was significantly higher than that in lamb (1.8 U/g; 1.4 U/g), turkey (1.2 U/g; 0.6 U/g), chicken (1.0 U/g; 0.7 U/g), and ostrich muscles (0.9 U/g; 0.8 U/g). GSHPx activiti

Limits of ultra-high-precision optical astrometry

Aims. To investigate the astrometric effects of stellar surface structures as a practical limitation to ultra-high-precision astrometry (e.g. in the context of exoplanet searches) and to quantify the expected effects in different regions of the HR-diagram. Methods. Stellar surface structures (spots, plages, granulation, non-radial oscillations) are likely to produce fluctuations in the integrated

Kuf, forskare och nazist

A short text on Herman Wirth, an esoteric nazi, with the focus on his period in Sweden 1948-53 (which builds on my own research)

Design of Wireless Communication Systems -- Issues on Synchronization, Channel Estimation and Multi-Carrier Systems

This thesis deals with certain aspects in the design of wireless communications systems. It is focused on problems related to the mobile or wireless channel: synchronization, channel estimation and design of wireless orthogonal frequency division multiplex (OFDM) systems. There is a short introduction to the field of wireless systems and a deeper review of pervious work and the state of the art in