Role of metal ions in the formation of amyloid deposits (in patients with Alzheimer's disease)

Cilj ovog rada je dati uvid u dosadašnja saznanja o interakcijama metalnih iona s amiloidogenim peptidom (Abeta-peptid), karakterističnim za Alzheimerovu bolest te o njihovom utjecaju na stvaranje amiloidnih nakupina. Najprije će ukratko biti riječ o patološkim obilježjima Alzheimerove bolesti koje uključuju nastajanje Abeta-peptida i poremećenu homeostazu metalnih iona. Detaljnije će biti razmotrena primarna i sekundarna struktura A-peptida i njegovih agregiranih nakupina, a zatim struktura kompleksa bakrovih(II) i cinkovih iona s Abeta-peptidom. Između ostalog, raspravit će se i neka važna svojstva kao što su stabilnost spomenutih kompleksa i afinitiet vezanja metalnih iona. Opisani su mogući mehanizmi agregacije Abeta-peptida bez i s metalnim ionima. U tom dijelu bit će prikazani rezultati i zaključci istraživanja vezanih za metalo-specifični utjecaj na agregaciju Abeta-peptida, stvaranje amiloidnih nakupina u odnosu na amorfne te utjecaj na termodinamiku i kinetiku agregacije Abeta-peptida

Nonlinear optimization in Hilbert space using Sobolev gradients with applications

The problem of finding roots or solutions of a nonlinear partial differential equation may be formulated as the problem of minimizing a sum of squared residuals. One then defines an evolution equation so that in the asymptotic limit a minimizer, and often a solution of the PDE, is obtained. The corresponding discretized nonlinear least squares problem is an often met problem in the field of numerical optimization, and thus there exist a wide variety of methods for solving such problems. We review here Newton's method from nonlinear optimization both in a discrete and continuous setting and present results of a similar nature for the Levernberg-Marquardt method. We apply these results to the Ginzburg-Landau model of superconductivity

Pengaruh Profitabilitas dan Struktur Modal terhadap Nilai Perusahaan dengan Good Corporate Governance sebagai Variabel Moderasi pada Jakarta Islamic Index

The purpose of this research was to analyze the effect of Profitability and Capital Structure on Firm Value and examine the effect of Good Corporate Governance in moderating the relationship between Profitability and Capital Structure with Firm Value in Jakarta Islamic Index. This research is a quantitative research using secondary data. The population of this research are 30 companies that llisted on Jakarta Islamic Index for a periode of 5 years, namely 2017-2021. The sampling technique used purposive sampling and found 11 companies that met the criteria as research samples. The data analysis technique used Multiple Regression Analysis and Moderated Regression Analysis (MRA). Data processing in this research using SPSS 25.0. The result of this research indicate that Profitability and Capital Structure simultaneously have a significant effect on Firm Value (PBV), then Profitability as measured by Return on Equity (ROE) partially has a significant positive effect on Firm Value (PBV), while Capital Structure as measured by Debt to Equity Ratio (DER) has a significant negative effect on Firm Value (PBV), meanwhile Good Corporate Governance as moderating variable proxied by the number of Directors is able to moderate the relationship between Profitability and Firm Value (PBV) in a positive direction, however, Good Corporate Governance can’t moderate the relationship between Capital Structure and Firm Value (PBV). Keywoard: Firm Value, Profitability, Capital Structure, Good Corporate Governance, Jakarta Islamic Index

Weak Lensing of the CMB by Large-Scale Structure

Several recent papers have studied lensing of the CMB by large-scale structures, which probes the projected matter distribution from $z=10^3$ to $z\simeq 0$. This interest is motivated in part by upcoming high resolution, high sensitivity CMB experiments, such as APEX/SZ, ACT, SPT or Planck, which should be sensitive to lensing. In this paper we examine the reconstruction of the large-scale dark matter distribution from lensed CMB temperature anisotropies. We go beyond previous work in using numerical simulations to include higher order, non-Gaussian effects and study how well the quadratic estimator of \cite{Hu01a} is able to recover the input field. We also study contamination by kinetic Sunyaev-Zel'dovich signals, which is spectrally indistinguishable from lensed CMB anisotropies. We finish by estimating the sensitivity of the previously cited experiments.Comment: 26 pages, 13 figures, replaced to match the minor revisions of the accepted versio

Determining the spectroscopic mass ratio in interacting binaries: Application to X-Ray Nova Sco 1994

We present a model for determining the mass ratio in interacting binaries by directly fitting the observed spectrum with synthetic spectra. We make direct use of NextGen model atmospheres intensities which are the most comprehensive and detailed models available for cool stars. We fully take into account the varying temperature and gravity across the secondary star's photosphere, by incorporating the synthetic spectra into the secondary star's Roche geometry. As a result, we determine the exact rotationally broadened spectrum of the secondary star and so eliminate the need for a limb-darkening law, and the uncertainties associated with it. As an example we determine the mass ratio for the well studied soft X-ray transient Nova Sco 1994. In order to obtain a more accurate determination of the mass ratio, which does not depend on assumptions about the rotation profile and limb-darkening coefficients, we use our model to compute the exact rotationally broadened model spectrum, which we compare directly with the observed intermediate resolution spectrum of Nova Sco 1994. We determine the mass ratio of Nova Sco 1994 to be 0.419+/-0.028 (90 percent confidence), which is the most accurate determination of the binary mass ratio in an X-ray binary. This result combined with the binary mass function and inclination angle gives a refined black hole mass of 5.99+\-0.42 Mo (90 percent confidence). We also perform simulations which show that, for an F-type secondary star, the standard rotation profile with zero and continuum value for the line limb-darkening coefficient gives a value for q that brackets the value found using the full geometrical treatment.Comment: 11 pages including 5 figures, accepted by MNRA

Estimating Continental and Terrestrial Precipitation Averages from Raingauge Networks

© 1994 by the Royal Meteorological Society. Available from the publisher's website at http://dx.doi.org/10.1002/joc.3370140405Influences of varying rain-gauge networks on continental and terrestrial precipitation averages (derived from data observed on those networks) are evaluated. Unsystematically and systematically designed station networks are considered, the latter being represented by the NCAR World Monthly Surface Station Climatology, which contains hand-picked but time-varying networks that date back to the 1800s. Biases arising from spatially uneven and temporally variable precipitation-observing networks can be significant. For all the continents, except South America, sparse rain-gauge networks produce overestimates of continental mean precipitation. Mean precipitation for South America, in contrast, is underestimated substantially by low densities of observing stations. Sampling errors tend to be large in areas of high precipitation and in regions with strong spatial precipitation gradients (e.g. in the Sahel). These patterns occur whether the station network has been selected systematically (as in the NCAR network) or unsystematically. Systematic sampling of mean precipitation (at the NCAR station locations), however, suggests that many yearly NCAR station networks are adequate for estimating continental average precipitation. As early as 1890, NCAR networks for Australia resolve continental average precipitation accurately. Not until 1960, however, do NCAR networks for South America begin to resolve continental mean precipitation adequately. Regional and continental NCAR network errors also tend to cancel one another, often giving accurate yearly estimates of terrestrial mean precipitation

TESELA: a new Virtual Observatory tool to determine blank fields for astronomical observations

The observation of blank fields, regions of the sky devoid of stars down to a given threshold magnitude, constitutes one of the typical important calibration procedures required for the proper reduction of astronomical data obtained in imaging mode. This work describes a method, based on the use of the Delaunay triangulation on the surface of a sphere, that allows the easy generation of blank fields catalogues. In addition to that, a new tool named TESELA, accessible through the WEB, has been created to facilitate the user to retrieve, and visualise using the VO-tool Aladin, the blank fields available near a given position in the sky.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society. 11 pages, 10 figures. Related Web tool accessible at http://sdc.cab.inta-csic.es/tesel