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The 16 - 22 amino-acid fragment of the beta-amyloid peptide associated with the Alzheimer's disease, Abeta, is capable of forming amyloid fibrils. Here we study the aggregation mechanism of Abeta(16-22) peptides by unbiased thermodynamic simulations at the atomic level for systems of one, three, and six Abeta(16-22) peptides. We find that the isolated Abeta(16-22) peptide is mainly a random coil i
A feedback neural network approach to communication routing problems is developed, with emphasis on Multiple Shortest Path problems, with several requests for transmissions between distinct start- and endnodes. The basic ingredients are a set of Potts neurons for each request,with interactions designed to minimize path lengths and to prevent overloading of network arcs. The topological nature of
Fitting a model to a time-dependent ensemble average is a process repeated frequently throughout biophysics. A selected ensemble-averaged observable (⟨y(t)⟩) for a given system can be predicted through the use of an estimated ensemble average, where the estimated ensemble average is created via simulated or experimental data sets. Fitting a model to this estimated ensemble average allows for estim
Previously, Berg and Purcell found an expression for the diffusion current of particles into a set of receptors in their paper Physics of Chemoreception. These receptors were assumed to be uniformly distributed on a spherical cell's surface and the receptors where idealized as circular patches. For their model, the particles' diffusion constant was the same for all points outside of the ce
Swedish legislation does not contain an explicit regulation regarding legal guardians’ liability to pay indemnity when children cause damage. The legal guardian has a supervision duty to observe, if violating this intentionally or by either negligence or willfulness the legal guardian risks liability for damages according to public liability. In 2010, the legislature chose to clarify the responsi
When did the Viking Age actually begin? Wood, turf, stone and daub – how did people live, and how were families organised? Power struggle, curiosity or greed? What were the incentives for Scandinavian expansion? What impact did the Scandinavians have on the Anglo-Saxon and Frankish kingdoms? These are some of the questions we will ask throughout the course, and you'll develop important skills in iWhen did the Viking Age actually begin? Wood, turf, stone and daub – how did people live, and how were families organised? Power struggle, curiosity or greed? What were the incentives for Scandinavian expansion? What impact did the Scandinavians have on the Anglo-Saxon and Frankish kingdoms? These are some of the questions we will ask throughout the course, and you'll develop important skills in i
A bone scan is a common method for monitoring bone metastases in patients with advanced prostate cancer. The Bone Scan Index (BSI) measures the tumor burden on the skeleton, expressed as a percentage of the total skeletal mass. Previous studies have shown that BSI is associated with survival of prostate cancer patients. The objective in this study was to investigate to what extent regional BSI mea
Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We present
We study how close-in systems such as those detected by Kepler are affected by the dynamics of bodies in the outer system. We consider two scenarios: outer systems of giant planets potentially unstable to planet-planet scattering and wide binaries that may be capable of driving Kozai or other secular variations of outer planets' eccentricities. Dynamical excitation of planets in the outer system r
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very hig
Planet–planet collisions are a common outcome of instability in systems of transiting planets close to the star, as well as occurring during in-situ formation of such planets from embryos. Previous N-body studies of instability amongst transiting planets have assumed that collisions result in perfect merging. Here, we explore the effects of implementing a more realistic collision prescription on t
Context. Streaming instability is a key mechanism in planet formation, clustering pebbles into planetesimals with the help of self-gravity. It is triggered at a particular disk location where the local volume density of solids exceeds that of the gas. After their formation, planetesimals can grow into protoplanets by feeding from other planetesimals in the birth ring as well as by accreting inward
The four major satellites of Jupiter, known as the Galilean moons, and Saturn's most massive satellite, Titan, are believed to have formed in a predominantly gaseous circum-planetary disk during the last stages of formation of their parent planet. Pebbles from the protoplanetary disk are blocked from flowing into the circumplanetary disk by the positive pressure gradient at the outer edge of the p
Context. The extensive stellar spectroscopic datasets that are available for studies in Galactic Archeaology thanks to, for example, the Gaia-ESO Survey, now benefit from having a significant number of targets that overlap with asteroseismology projects such as Kepler, K2, and CoRoT. Combining the measurements from spectroscopy and asteroseismology allows us to attain greater accuracy with regard
Context. In the era of large spectroscopic surveys, massive databases of high-quality spectra coupled with the products of the Gaia satellite provide tools to outline a new picture of our Galaxy. In this framework, an important piece of information is provided by our ability to infer stellar ages, and consequently to sketch a Galactic timeline. Aims. We aim to provide empirical relations between s
Abstract The majority of airborne particles in residences, when expressed as number concentrations, are generated by the residents themselves, through combustion/thermal related activities. These particles have a considerably smaller diameter than 2.5 μm and, due to the combination of their small size, chemical composition (e.g. soot) and intermittently very high concentrations, should be regard
BACKGROUND: The objective of this study was firstly to develop and evaluate an automated method for the detection of new lesions and changes in bone scan index (BSI) in serial bone scans and secondly to evaluate the prognostic value of the method in a group of patients receiving chemotherapy.METHODS: The automated method for detection of new lesions was evaluated in a group of 266 patients using t
The purpose of this report is to evaluate the safety of life during evacuation from the icebreaker Sankt Erik in Stockholm in the event of fire onboard. Sankt Erik was decommissioned in 1977 and operates since 1980 as a museum under the Swedish Maritime Museum in Stockholm, moored at Galärvarvet. Being a museum no major alterations to the structure are allowed. Furthermore, the majority of the mat
