A travel time-based variable grid approach for an activity-based cellular automata model

Urban growth and population growth are used in numerous models to determine their potential impacts on both the natural and the socio-economic systems. Cellular automata (CA) land-use models became popular for urban growth modelling since they predict spatial interactions between different land uses in an explicit and straightforward manner. A common deficiency of land-use models is that they only deal with abstract categories, while in reality, several activities are often hosted at one location (e.g. population, employment, agricultural yield, nature…). Recently, a multiple activity-based variable grid CA model was proposed to represent several urban activities (population and economic activities) within single model cells. The distance-decay influence rules of the model included both short- and long-distance interactions, but all distances between cells were simply Euclidean distances. The geometry of the real transportation system, as well as its interrelations with the evolving activities, were therefore not taken into account. To improve this particular model, we make the influence rules functions of time travelled on the transportation system. Specifically, the new algorithm computes and stores all travel times needed for the variable grid CA. This approach provides fast run times, and it has a higher resolution and more easily modified parameters than the alternative approach of coupling the activity-based CA model to an external transportation model. This paper presents results from one Euclidean scenario and four different transport network scenarios to show the effects on land-use and activity change in an application to Belgium. The approach can add value to urban scenario analysis and the development of transport- and activity-related spatial indicators, and constitutes a general improvement of the activity-based CA model

High-resolution simulations of population-density change with an activity-based cellular automata land-use model

The MOLAND model is a cellular automata (CA) land-use change model that has often been applied to simulate urban growth. A more recent alternative model makes the simulations more multifunctional by also computing different activities (population and employment) for every cell. However, the equation to update population density in time in this activity-based CA model could not deal with high population growth rates in some existing urban centres. Therefore, we experimented with two alternative equations. A semi-automated calibration routine was used to compare errors of the different model versions at a continuous range of resolutions in two study areas: the Greater Dublin Region, Ireland, and Flanders and Brussels, Belgium. The two new population density equations turn out to solve the particular problem of fast changes in high-density neighbourhoods and generally improve regional errors in the Belgian application, but can unfortunately introduce larger errors in low-density areas or in the land-use simulations

Solid state protein monolayers: morphological, conformational, and functional properties

We have studied the morphological, conformational, and electron-transfer (ET) function of the metalloprotein azurin in the solid state, by a combination of physical investigation methods, namely atomic force microscopy, intrinsic fluorescence spectroscopy, and scanning tunneling microscopy. We demonstrate that a “solid state protein film” maintains its nativelike conformation and ET function, even after removal of the aqueous solvent

The effect of pH and ligand exchange on the redox properties of blue copper proteins

Macromolecular Biochemistr

A new type 2 copper cysteinate azurin: Involvement of an engineered exposed cysteine in copper binding trough internal rearrangement

The double mutant H117G/N42C azurin exhibits tetragonal type 2 copper site characteristics with Cys(42) as one of the copper ligands as concluded from spectroscopic evidence (UV-visible, EPR, and resonance Raman). Analysis of the kinetics of copper uptake by the apoprotein by means of stopped flow spectroscopy suggests that the solvent-exposed CyS42 assists in binding the metal ion and carrying it over to the active site where it becomes coordinated by, among others, a second cysteine, Cys(112). A structure is proposed in which the loop from residue 36 to 47 has rearranged to form a tetragonal type 2 copper site with Cys(42) as one of the ligands. The process of copper uptake as observed for the double mutant may be relevant for a better understanding of the way copper chaperones accept and transfer metal ions in the living cell.Macromolecular Biochemistr

Chemical exchange at the tri-nuclear copper centre of small laccase from Streptomyces coelicolor

The trinuclear copper center (TNC) of laccase reduces oxygen to water with very little overpotential. The arrangement of the coppers and ligands in the TNC is known to be from many crystal structures, yet information about possible dynamics of the ligands is absent. Here, we report dynamics at the TNC of small laccase from Streptomyces coelicolor using paramagnetic NMR and electron paramagnetic resonance spectroscopy. Fermi contact-shifted resonances tentatively assigned to histidine Hd1 display a two-state chemical exchange with exchange rates in the order of 100 s1 . In the electron paramagnetic resonance spectra, at least two forms are observed with different gz-values. It is proposed that the exchange processes reflect the rotational motion of histidine imidazole rings that coordinate the coppers in the TNC.Macromolecular BiochemistrySolid state NMR/Biophysical Organic Chemistr

Solid state protein monolayers: morphological, conformational, and functional properties

We have studied the morphological, conformational, and electron-transfer (ET) function of the metalloprotein azurin in the solid state, by a combination of physical investigation methods, namely atomic force microscopy, intrinsic fluorescence spectroscopy, and scanning tunneling microscopy. We demonstrate that a “solid state protein film” maintains its nativelike conformation and ET function, even after removal of the aqueous solvent.Microbial Biotechnolog

Подсистема автономного программно-аппаратного комплекса для индуктивного долгосрочного прогноза осредненных значений метеопараметров

The research of the inductive method of long-term (forestalling to 0,5 year) prognosis of average decade air s temperature on the basis of principle of analogies was executed and it s sufficient was shown. The research of the offered approach was also conducted: in the base of spatial models without principle of analogies; in the polynomial harmonic base; the analysis of middle quality of the inductive prognostic method for cases of the analogue principle usage and without it

Age-Related Toxoplasma gondii Seroprevalence in Dutch Wild Boar Inconsistent with Lifelong Persistence of Antibodies

Toxoplasma gondii is an important zoonotic pathogen that is best known as a cause of abortion or abnormalities in the newborn after primary infection during pregnancy. Our aim was to determine the prevalence of T. gondii in wild boar to investigate the possible role of their meat in human infection and to get an indication of the environmental contamination with T. gondii. The presence of anti-T. gondii antibodies was determined by in-house ELISA in 509 wild boar shot in 2002/2003 and 464 wild boar shot in 2007. Most of the boar originated from the “Roerstreek” (n = 673) or the “Veluwe” (n = 241). A binormal mixture model was fitted to the log-transformed optical density values for wild boar up to 20 months old to estimate the optimal cut-off value (−0.685) and accompanying sensitivity (90.6%) and specificity (93.6%). The overall seroprevalence was estimated at 24.4% (95% CI: 21.1–27.7%). The prevalence did not show variation between sampling years or regions, indicating a stable and homogeneous infection pressure from the environment. The relation between age and seroprevalence was studied in two stages. Firstly, seroprevalence by age group was determined by fitting the binary mixture model to 200 animals per age category. The prevalence showed a steep increase until approximately 10 months of age but stabilized at approximately 35% thereafter. Secondly, we fitted the age-dependent seroprevalence data to several SIR-type models, with seropositives as infected (I) and seronegatives as either susceptible (S) or resistant (R). A model with a recovery rate (SIS) was superior to a model without a recovery rate (SI). This finding is not consistent with the traditional view of lifelong persistence of T. gondii infections. The high seroprevalence suggests that eating undercooked wild boar meat may pose a risk of infection with T. gondii