Современное состояние фенологии и перспективы ее развития
Problems of phenological observations in Russia
Many environmental stimuli present a quasi-rhythmic structure at different timescales that the brain needs to decompose and integrate. Cortical oscillations have been proposed as instruments of sensory de-multiplexing, i.e., the parallel processing of different frequency streams in sensory signals. Yet their causal role in such a process has never been demonstrated. Here, we used a neural microcircuit model to address whether coupled theta–gamma oscillations, as observed in human auditory cortex, could underpin the multiscale sensory analysis of speech. We show that, in continuous speech, theta oscillations can flexibly track the syllabic rhythm and temporally organize the phoneme-level response of gamma neurons into a code that enables syllable identification. The tracking of slow speech fluctuations by theta oscillations, and its coupling to gamma-spiking activity both appeared as critical features for accurate speech encoding. These results demonstrate that cortical oscillations can be a key instrument of speech de-multiplexing, parsing, and encoding.
Pollen plants are investigated
The situation in phenology is discussed
Problems of phenological observations in Russia
The dynamics of the dates of the onset of phenological events such as the arrival of starlings (Sturnus vulgaris L.), the first cuckoo song (Cuculus canorus), the appearance of the first birch leaves (Betula verrucosa Ehrh.), the bird cherry (Padus racemosa Lam.) and the very early flowering of the rowan (Sorbus aucuparia L.) allows us to conclude that there is an increasing trend in the duration of spring, while the duration of the fall season for the period from 1967 to 2010 is practically unchanged. For the beginning of bird cherry flowering, the offset of the trend to earlier dates is more typical for the forest and forest-steppe territories of the Russian Plain, what suggests the connection between climatic parameters. For the appearance of the first birch leaves, the multi-directional trends of the offset of dates is obvious and revealed no dependence on natural conditions and physiographical position. The advanced arrival of starlings and the start of cuckoo song cannot be used as reliable indicators. No reaction to the unique weather conditions was demonstrated by birds. It is possible that the mechanisms of migration of birds are more likely caused by the presence or absence of prey and endogenous biological rhythms.
The phenological tendencies in Russien plain nature are discussed
The study addresses changes in the phenological characteristics of common birch (silver birch), bird cherry, mountain ash (rowan), and small-leaves lime (linden) in the central part of European Russia (ER) on the basis of multiyear observations of the beginning of the first leaves unfolding phase for birches and the flowering phase for bird cherry, mountain ash, and linden in the period since 1976 and until 2015 (the period of most intense modern warming in Russia). Overall, the current climate change affects the phenology of all these species; however, various species demonstrate spatial and calendar differences in their phenological reactions. Bird cherry and rowan do not demonstrate significant trends in their flowering dates (or weak positive values of the linear trend coefficient) in territories located between 52° and 54° N. To the north and south of that area, the value of the coefficient is negative: up to –1.5 days/10 years for cherry, and up to and 1.0 days/10 years for rowan. However, for linden, the area of positive values extends northwards to 56° N. The discrepancies in the trends of phenological stages and trends of dates of the stable transition of the air temperature across threshold values close to the phenological stages are 2 – 10 for birch, bird cherry and rowan and up to 8–25 times for linden. A similar correlation has been observed between the phenological trends and sums of active temperatures. This demonstrates the work of adaptation homeostatic mechanisms in the plants in response to the climate change.
One of the key advances in genome assembly that has led to a significant improvement in contig lengths has been improved algorithms for utilization of paired reads (mate-pairs). While in most assemblers, mate-pair information is used in a post-processing step, the recently proposed Paired de Bruijn Graph (PDBG) approach incorporates the mate-pair information directly in the assembly graph structure. However, the PDBG approach faces difficulties when the variation in the insert sizes is high. To address this problem, we first transform mate-pairs into edge-pair histograms that allow one to better estimate the distance between edges in the assembly graph that represent regions linked by multiple mate-pairs. Further, we combine the ideas of mate-pair transformation and PDBGs to construct new data structures for genome assembly: pathsets and pathset graphs.
The paper studies a problem of optimal insurer’s choice of a risk-sharing policy in a dynamic risk model, so-called Cramer-Lundberg process, over infinite time interval. Additional constraints are imposed on residual risks of insureds: on mean value or with probability one. An optimal control problem of minimizing a functional of the form of variation coefficient is solved. We show that: in the first case the optimum is achieved at stop loss insurance policies, in the second case the optimal insurance is a combination of stop loss and deductible policies. It is proved that the obtained results can be easily applied to problems with other optimization criteria: maximization of long-run utility and minimization of probability of a deviation from mean trajectory.