Czech White-Nose Syndrome Team together with international collaborators discovered mechanisms of tolerance that protect Palearctic bats from white-nose syndrome (WNS), the disease that caused mass die-off in North America. The discovery raises hope for a better future of bats in North American ecosystems. White-nose syndrome (WNS) is caused by a generalist pathogen Pseudogymnoascus destructans with the worst possible characteristics of an infectious fungal agent. The generalist nature of the WNS fungus means that it can infect any bat hibernating in a contaminated cave or mine and, moreover, it may remain viable and virulent, waiting for its hosts until the next hibernation period. Harmless to humans, the WNS fungus kills hibernating North American bats in winter. However, loss of voracious insectivorous bats from agricultural ecosystems may result in economic costs required for increased pest control. Without mass die-offs of bats harbouring the WNS agent in Europe, the response to disease is an enigma. To study the survival crossroads, the Czech WNS Team focused on the relationship between pathogen quantity and disease under natural conditions. High disease prevalence together with high fungal loads in absence of bat population declines in Eurasia indicates disease tolerance mechanisms, where hosts limit harm inflicted by the pathogen but do not hinder its growth. The tolerance mechanisms revealed by the Czech WNS Team is a function of bat adaptation to the presence of the pathogen. and Natália Martínková.
The Evolutionary Argument (EA) plays the central role in the realism- antirealism dispute. Proponents of this argument maintain that evolutionary theory pro- vides a convincing evidence for the reliability of our cognitive capacities. The evolutio- nary function of these capacities is to inform us about the character of our environment; and, as evidenced by the survival of our species, we can surmise that our cognitive capac- ities tend to provide a true, rather than false, picture of the world (cf., e.g., Quine, Kornblith, Munz). However, opponents of this view argue that evolutionary processes are not exclusively adaptive or optimal; indeed, some processes may not be adaptive at all (cf., e.g., Putnam, van Fraassen, Stich, and Bradie). Some of these critics, e.g., Thomson, believe that evolutionary theory demonstrates that our knowledge is not true, and that our cognitive capacities are not only fallible but completely unreliable. They produce only one of the many possible pictures of the world. I criticize this type of argument by means of a non-adaptationist interpretation of evolutionary theory (Wuketits), and I am seeking an evolutionary way out., Evoluční argument (EA) hraje ústřední roli v realisticko-antirealismickém sporu. Zastánci tohoto argumentu tvrdí, že evoluční teorie poskytuje přesvědčivý důkaz spolehlivosti našich kognitivních schopností. Důležitou funkcí těchto kapacit je informovat nás o charakteru našeho prostředí; a, jak dokazuje přežití našeho druhu, můžeme se domnívat, že naše kognitivní kapacity mají sklon poskytovat pravdivý, spíše než falešný obraz světa (srov. např. Quine, Kornblith, Munz). Nicméně, oponenti tohoto pohledu argumentují, že evoluční procesy nejsou výhradně adaptivní nebo optimální; některé procesy nemusí být vůbec adaptivní (srov. např. Putnam, van Fraassen, Stich a Bradie). Někteří z těchto kritiků, např. Thomson, věří, že evoluční teorie dokazuje, že naše znalosti nejsou pravdivé a že naše kognitivní schopnosti nejsou jen omylné, ale zcela nespolehlivé. Vyrábí pouze jeden z mnoha možných obrazů světa. Tento druh argumentů kritizuji prostřednictvím neadaptistické interpretace evoluční teorie (Wuketits) a hledám evoluční cestu ven., and Vladimír Havlík
Příspěvek pojednává o využití výpočetní techniky ve fyzikálních vědách, speciálně o aplikaci evolučních algoritmů v problematice deterministického chaosu. V obou ukázkových studiích jsou použity jak klasické evoluční algoritmy, tak algoritmy moderní. Veškeré údaje byly získány mnohonásobně opakovanými simulacemi, jejichž výsledky jasně poukazují na robustnost a životaschopnost použitých metod. Získaná řešení a postupy k nim vedoucí uvedené v článku jsou diskutovány pouze na úrovni informativního charakteru; pro nastudování plného popisu jsou na konci příspěvku uvedeny potřebné odkazy., Ivan Zelinka, Roman Šenkeřík, Zuzana Oplatková., and Obsahuje seznam literatury
Changes in photosynthetic attributes related to genetic improvement of cotton yield were studied in seven Chinese cotton cultivars widely grown in Xinjiang during the past 30 years. Our results showed that a chlorophyll (Chl) content and net photosynthetic rate (PN) of the 1980s cultivar was the highest among all after 60 days from planting (DAP). However, after 75 DAP, the Chl content, PN, and actual photochemical efficiency of PSII of the old cultivars declined gradually, whereas those of the new cultivars remained relatively high. Compared to the old cultivars, leaves of the new cultivars endured a longer period and their senescence was slower, shoot and boll dry mass was higher, but the root to shoot ratio was lower. The lint yield of the 2000s cultivars was 14.7 and 21.4% higher than that of 1990s and 1980s cultivars, respectively. The high yield of the new cultivars was attributed to a greater number of bolls per unit of area with high lint percentage. We suggested that the improved photosynthetic capacity and the increased ability to deliver photosynthates to reproductive sites during the peak boll-setting stage to boll-opening stage were the key physiological basis in the evolution process of cotton cultivars from 1980s to 2000s for the cotton yield improvement within a short growing period., H. H. Luo, H. L. Zhang, Y. L. Zhang, W. F. Zhang., and Obsahuje bibliografii
Kinetic equations for the distribution function of dust particles in mass and element spaces are formulated. Erosive as well as catastrophic collisions are taken into account. Sputtering is also included and radiative effects are considered. Initial conditions are derived from the Interplanetary Flux Model for mass distribution, and fan or cosine models for spatial density.
We prove L2-maximal regularity of the linear non-autonomous evolutionary Cauchy problem \dot u(t) + A(t)u(t) = f(t){\text{ for a}}{\text{.e}}{\text{. }}t \in \left[ {0,T} \right],{\text{ }}u(0) = {u_0}, where the operator A(t) arises from a time depending sesquilinear form a(t, ·, ·) on a Hilbert space H with constant domain V. We prove the maximal regularity in H when these forms are time Lipschitz continuous. We proceed by approximating the problem using the frozen coefficient method developed by El-Mennaoui, Keyantuo, Laasri (2011), El-Mennaoui, Laasri (2013), and Laasri (2012). As a consequence, we obtain an invariance criterion for convex and closed sets of H., Ahmed Sani, Hafida Laasri., and Obsahuje seznam literatury
A meteoroid stream generally considered to be an elliptical ring of relatively small thickness. Such shape is attributable to meteoroid streams in an early stage of their evolution. Differences in planetary perturbations influencing the meteoroid particles ejected from the parent body from various points in its orbit at different velocities and time can result in a significant thickening
of the stream. Our studies on the evolution of the short-period meteoroid streams have shown that these streams can produce several couples of showers active indifferent seasons of the year.
Realistic N-body simulations of open clusters are discussed and compared with main observed cluster features. Most of the models have 1000 bodies with initial masses following a power law mass function of slope α = -2.75. Instantaneous mass loss from stellar evolution; a smooth linearized galactic tidal field and transient shocks by encounters with extended interstellar clouds of different mass-spectrum, density and space concentration are included. Close approaches between particles are treated by a two-body regularization technique that allows to follow binary evolution in detail. Good agreement is found between the distribution of lifetime for galactic clusters and the life of the models. It is found that the combined action of evolutionary mass loss and binaries (for 1000 star clusters with a realistic mass function) is enough to arrest the core collapse. Tidal heating shapes the halo of the cluster and produces a distinctive density and velocity distribution. Encounters with standard clouds do not alter the life-time of the clusters; while giant molecular clouds produce a catastrophic disruption. Mass segregation and preferential escape of light stars can account for the depletion of low luminosity stars in the better observed central region of clusters. Work on the primordial stages of evolution of clusters during star formation is reviewed, and linked to work on
N-body clusters.