OpenLB User Guide: Associated with Release 1.6 of the Code

OpenLB is an object-oriented implementation of LBM. It is the first implementation of a generic platform for LBM programming, which is shared with the open source community (GPLv2). Since the first release in 2007, the code has been continuously improved and extended which is documented by thirteen releases as well as the corresponding release notes which are available on the OpenLB website (https://www.openlb.net). The OpenLB code is written in C++ and is used by application programmers as well as developers, with the ability to implement custom models OpenLB supports complex data structures that allow simulations in complex geometries and parallel execution using MPI, OpenMP and CUDA on high-performance computers. The source code uses the concepts of interfaces and templates, so that efficient, direct and intuitive implementations of the LBM become possible. The efficiency and scalability has been checked and proved by code reviews. This user manual and a source code documentation by DoxyGen are available on the OpenLB project website

Land-Use Changes at Nest Sites of the Little Owl (Athene noctua) in the South-Moravian Region of the Czech Republic

The Little Owl is currently endangered bird species of agricultural lowland areas in Central Europe. Nesting sites of the Little Owl are often old trees as well as buildings and quarries with suitable nesting cavities. The Little Owl has severely declined in a major part of Europe during the past decades. Information on habitat requirements of the Little Owl and data related to land-use changes at nest sites (covering both the breeding and foraging habitats) are needed for conservation programmes aimed at this bird species. Land-use changes in farmland rank among frequently discussed negative factors causing the population decline of the Little Owl. The aim of this study is to analyse land-use changes at nest sites of the Little Owl in the South-Moravian region (Czech Republic) between the years 1976/1977 and 2014. In both studied periods (1976/1977 and 2014), the most important land-use type within 500 m from the nest sites of the Little Owl was arable land (66.94 % – 62.25 %), followed by built-up areas (19.97 % –22.41 %), while the other land-use types made up less than 5 %. The proportion of the particular land-use type did not change significantly between the years 1976/1977 and 2014. The most important change in comparison with the period 1976/1977 was the decrease in the area of arable land by 4.69 % and that of orchards and gardens by 1.99 %, while the surface of built-up areas increased slightly by 2.45 % and that of meadows and pastures by 1.5 %. The analysis shows that at the known nest sites of the Little Owl in the South-Moravian region (Czech Republic), there were no significant changes in the proportion of the particular land-use types within 500 m from the nests between the years 1976/1977 and 2014. Based on these results, we can conclude that in comparison with the availability of nest sites, which seems to be the important limiting factor for the occurrence and population density of the Little Owl, land-use changes in study area were not very important factor influencing decline of the Little Owl

Plant Development under Simulated Microgravity Conditions

Bioregenerative Life Support Systems will represent one of the future needs in context of long-term manned space missions. The demand for nutrition, recycling of carbon dioxide, production of oxygen and other chemical compounds and also the psychological well-being of humans can be fulfilled with plant based life support systems in an improved way. However, there are some fundamental differences between plant cultivation on Earth and in space, mainly due to the lack of gravity and increased radiation. Therefore, it is aimed to modify plants by breeding or genetic engineering to obtain germination, growth rates and reproduction under space conditions as optimal as possible. The first step to such an approach is to study the effects of gravity on plant development with hypergravity and simulated microgravity experiments on earth. Cell walls, functioning as an exoskeleton of a plant cell, provide the stability and shape of different cell types needed to form tissues and organs in presence of gravitational force. In order to understand early processes in alteration of cell wall composition in microgravity, 2D-clinorotated Arabidopsis thaliana roots were investigated in an immunohistochemical and electron microscopical approach. The parameters of simulation were chosen for the plant system due to results obtained by a comparative approach, testing the effect of fast clinorotation versus real random mode operation on a random positioning machine with respect to the displacement of statoliths. Based on these results, the 2D-clinostat was selected to provide a qualitative good simulation. Pectins, important cell wall matrix polysaccharides, were immunhistochemically visualized, revealing a relative lower abundance of pectins in 3 h clinorotated samples compared with the 1 g control samples. Interestingly, short term exposure to microgravity reduces pectins without impact on cell wall thickness as revealed by electron microscopy