Basis Of Adaptive Changes Research Articles

ПРИМЕНЕНИЕ ПРОГРАММИРУЕМЫХ ЛОГИЧЕСКИХ ИНТЕГРАЛЬНЫХ СХЕМ В СИСТЕМАХ МНОГОКАНАЛЬНОЙ ЦИФРОВОЙ ОБРАБОТКИ СИГНАЛОВ СПУТНИКОВОЙ НАВИГАЦИИ

The study analyzes multichannel digital satellite navigation signal processing systems for unmanned aerial vehicles. To advance interference insusceptibility of navigation equipment on the basis of adaptive change in settings, it is advisable to apply a field programmable gate arrays in order to implement variations of algorithms of signal processing without reconfiguring the equipment’s structure in changes in radioelectronic settings. A navigation complex with the function of interference insusceptibility is developed based on the field programmable gate arrays. It may simultaneously receive signals from such satellite navigation systems as GLONASS, GPS, QZSS, BeiDou, Galileo, and NavIC via four independently tuned channels and their digital processing using adaptive filtering algorithms. Patterns in spatial selectivity of signals are studied, as are the possibilities for navigation equipment adaptability in interference settings using programs for electrodynamic modeling of adaptive antenna arrays ‒ SolidWorks, Altium Designer, and Quartus.

Heart transcriptome of the bank vole (Myodes glareolus): towards understanding the evolutionary variation in metabolic rate

BackgroundUnderstanding the genetic basis of adaptive changes has been a major goal of evolutionary biology. In complex organisms without sequenced genomes, de novo transcriptome assembly using a longer read sequencing technology followed by expression profiling using short reads is likely to provide comprehensive identification of adaptive variation at the expression level and sequence polymorphisms in coding regions. We performed sequencing and de novo assembly of the bank vole heart transcriptome in lines selected for high metabolism and unselected controls.ResultsA single 454 Titanium run produced over million reads, which were assembled into 63,581 contigs. Searches against the SwissProt protein database and the ENSEMBL collection of mouse transcripts detected similarity to 11,181 and 14,051 genes, respectively. As judged by the representation of genes from the heart-related Gene Ontology categories and UniGenes detected in the mouse heart, our detection of the genes expressed in the heart was nearly complete (> 95% and almost 90% respectively). On average, 38.7% of the transcript length was covered by our sequences, with notably higher (45.0%) coverage of coding regions than of untranslated regions (24.5% of 5' and 32.7% of 3'UTRs). Lower sequence conservation between mouse and bank vole in untranslated regions was found to be partially responsible for poorer UTR representation. Our data might suggest a widespread transcription from noncoding genomic regions, a finding not reported in previous studies regarding transcriptomes in non-model organisms. We also identified over 19 thousand putative single nucleotide polymorphisms (SNPs). A much higher fraction of the SNPs than expected by chance exhibited variant frequency differences between selection regimes.ConclusionLonger reads and higher sequence yield per run provided by the 454 Titanium technology in comparison to earlier generations of pyrosequencing proved beneficial for the quality of assembly. An almost full representation of genes known to be expressed in the mouse heart was identified. Usage of the extensive genomic resources available for the house mouse, a moderately (20-40 mln years) divergent relative of the voles, enabled a comprehensive assessment of the transcript completeness. Transcript sequences generated in the present study allowed the identification of candidate SNPs associated with divergence of selection lines and constitute a valuable permanent resource forming a foundation for RNAseq experiments aiming at detection of adaptive changes both at the level of gene expression and sequence variants, that would facilitate studies of the genetic basis of evolutionary divergence.

Genetic adaptation to captivity in species conservation programs

As wild environments are often inhospitable, many species have to be captive-bred to save them from extinction. In captivity, species adapt genetically to the captive environment and these genetic adaptations are overwhelmingly deleterious when populations are returned to wild environments. I review empirical evidence on (i) the genetic basis of adaptive changes in captivity, (ii) factors affecting the extent of genetic adaptation to captivity, and (iii) means for minimizing its deleterious impacts. Genetic adaptation to captivity is primarily due to rare alleles that in the wild were deleterious and partially recessive. The extent of adaptation to captivity depends upon selection intensity, genetic diversity, effective population size and number of generation in captivity, as predicted by quantitative genetic theory. Minimizing generations in captivity provides a highly effective means for minimizing genetic adaptation to captivity, but is not a practical option for most animal species. Population fragmentation and crossing replicate captive populations provide practical means for minimizing the deleterious effects of genetic adaptation to captivity upon populations reintroduced into the wild. Surprisingly, equalization of family sizes reduces the rate of genetic adaptation, but not the deleterious impacts upon reintroduced populations. Genetic adaptation to captivity is expected to have major effects on reintroduction success for species that have spent many generations in captivity. This issue deserves a much higher priority than it is currently receiving.

Adaptation in Macaque MT Reduces Perceived Speed and Improves Speed Discrimination

The visual system adapts to its environment. Some adaptive changes are detrimental-perception is no longer veridical. Others are beneficial-the ability to discriminate two stimuli improves. The latter may reflect the visual system's ability to zoom-in on the currently relevant properties of the environment. We studied the neural basis of adaptive changes in the middle temporal area (MT) of macaque monkey visual cortex. Our data show that brief adaptation to a moving stimulus reduces the magnitude of neural responses and reduces the width of speed tuning curves. Comparable with what has recently been reported in the direction domain, the response reduction was largest when the test speed was different from the adaptation speed. Using an ideal observer analysis, we show that these response changes in MT are consistent with a reduction in perceived speed as well as an improvement in speed discrimination. This supports the view that adaptive response changes in MT are not just a consequence of neural fatigue, but an active process that enhances the discrimination of speed.

Cystometrical and in Vitro Evaluation of Urinary Bladder Function in Rats with Streptozotocin-Induced Diabetes

Micturition pattern and cystometric characteristics were determined in control rats, and in rats with streptozotocin-induced diabetes (six weeks duration). The diabetic rats had an increased frequency of micturition, an increased micturition volume, and an increased 24 hr. urinary output. The cystometry showed that the diabetic bladders had an increased compliance and a higher threshold volume for initiating a micturition reflex. No spontaneous rhythmic contractions were seen during the filling phase, and no residual urine could be detected. While micturition pressure increased, the micturition time was virtually unaltered. In vitro a right-ward shift for passive and active length-tension relations was noted. The observed changes in cystometric characteristics and length-tension relations might probably be explained on the basis of adaptive changes to the increased diuresis involving both sensory and motor control of the urinary bladder