1,178 research outputs found
Random and exhaustive generation of permutations and cycles
In 1986 S. Sattolo introduced a simple algorithm for uniform random
generation of cyclic permutations on a fixed number of symbols. This algorithm
is very similar to the standard method for generating a random permutation, but
is less well known.
We consider both methods in a unified way, and discuss their relation with
exhaustive generation methods. We analyse several random variables associated
with the algorithms and find their grand probability generating functions,
which gives easy access to moments and limit laws.Comment: 9 page
Mlh2 is an accessory factor for DNA mismatch repair in Saccharomyces cerevisiae.
In Saccharomyces cerevisiae, the essential mismatch repair (MMR) endonuclease Mlh1-Pms1 forms foci promoted by Msh2-Msh6 or Msh2-Msh3 in response to mispaired bases. Here we analyzed the Mlh1-Mlh2 complex, whose role in MMR has been unclear. Mlh1-Mlh2 formed foci that often colocalized with and had a longer lifetime than Mlh1-Pms1 foci. Mlh1-Mlh2 foci were similar to Mlh1-Pms1 foci: they required mispair recognition by Msh2-Msh6, increased in response to increased mispairs or downstream defects in MMR, and formed after induction of DNA damage by phleomycin but not double-stranded breaks by I-SceI. Mlh1-Mlh2 could be recruited to mispair-containing DNA in vitro by either Msh2-Msh6 or Msh2-Msh3. Deletion of MLH2 caused a synergistic increase in mutation rate in combination with deletion of MSH6 or reduced expression of Pms1. Phylogenetic analysis demonstrated that the S. cerevisiae Mlh2 protein and the mammalian PMS1 protein are homologs. These results support a hypothesis that Mlh1-Mlh2 is a non-essential accessory factor that acts to enhance the activity of Mlh1-Pms1
ΠΠ»ΠΈΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΠΈ ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² ΠΊΠ»ΠΈΠΌΠ°ΡΠ° Π² ΡΠ°ΠΉΠΎΠ½Π°Ρ Π²Π΅ΡΠ½ΠΎΠΉ ΠΌΠ΅ΡΠ·Π»ΠΎΡΡ Π½Π° ΡΠ΅ΡΡΠΈΡΠΎΡΠΈΠΈ ΡΠ΅Π²Π΅ΡΠ° ΠΠ°ΠΏΠ°Π΄Π½ΠΎΠΉ Π‘ΠΈΠ±ΠΈΡΠΈ
ΠΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ ΡΠ°Π±ΠΎΡΡ ΡΠ²ΡΠ·Π°Π½Π° Ρ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎΡΡΡΡ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ ΠΊΠ»ΠΈΠΌΠ°ΡΠ°, Π²Π»ΠΈΡΡΡΠΈΡ
Π½Π° ΠΌΠ½ΠΎΠ³ΠΎΠ»Π΅ΡΠ½ΡΡ ΠΌΠ΅ΡΠ·Π»ΠΎΡΡ, Π² ΡΠ²ΡΠ·ΠΈ Ρ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΡΠΌ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ Π²ΡΠ±ΡΠΎΡΠΎΠ² ΠΏΠ°ΡΠ½ΠΈΠΊΠΎΠ²ΡΡ
Π³Π°Π·ΠΎΠ² ΠΈ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ Π°Π²Π°ΡΠΈΠΉΠ½ΠΎΡΡΠΈ Π½Π° ΠΎΠ±ΡΠ΅ΠΊΡΠ°Ρ
ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΠΉ, Π² ΡΠΎΠΌ ΡΠΈΡΠ»Π΅ ΠΈ Π½Π΅ΡΡΠ΅Π³Π°Π·ΠΎΠ²ΠΎΠΉ, ΠΈΠ½ΡΡΠ°ΡΡΡΡΠΊΡΡΡΡ ΠΏΡΠΈ ΡΠ°ΡΠ½ΠΈΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠ»Π΅ΡΠ½Π΅ΠΌΠ΅ΡΠ·Π»ΡΡ
ΠΏΠΎΡΠΎΠ΄. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ: ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ ΠΊΠ»ΠΈΠΌΠ°ΡΠ°, Π½Π΅ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²Π΅Π½Π½ΠΎ Π²Π»ΠΈΡΡΡΠΈΡ
Π½Π° ΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΏΠΎΡΠ²ΠΎΠ³ΡΡΠ½ΡΠΎΠ² Π² ΡΠ°ΠΉΠΎΠ½Π°Ρ
ΡΠ°ΡΠΏΡΠΎΡΡΡΠ°Π½Π΅Π½ΠΈΡ ΠΌΠ½ΠΎΠ³ΠΎΠ»Π΅ΡΠ½Π΅ΠΉ ΠΌΠ΅ΡΠ·Π»ΠΎΡΡ ΡΠ΅Π²Π΅ΡΠ° ΠΠ°ΠΏΠ°Π΄Π½ΠΎΠΉ Π‘ΠΈΠ±ΠΈΡΠΈ. ΠΠ΅ΡΠΎΠ΄Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ. ΠΠ½Π°Π»ΠΈΠ· ΠΌΠ½ΠΎΠ³ΠΎΠ»Π΅ΡΠ½ΠΈΡ
ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ ΠΌΠ΅ΡΠ΅ΠΎΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
Π΄Π°Π½Π½ΡΡ
Π²ΠΊΠ»ΡΡΠ°Π» Π² ΡΠ΅Π±Ρ ΠΏΡΠΎΠ²Π΅ΡΠΊΡ Π½ΡΠ»Π΅Π²ΡΡ
Π³ΠΈΠΏΠΎΡΠ΅Π· ΠΎ ΡΠ»ΡΡΠ°ΠΉΠ½ΠΎΡΡΠΈ ΠΈ ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΠΎΡΡΠΈ ΡΡΠ΄ΠΎΠ² Π½Π°Π±Π»ΡΠ΄Π΅Π½ΠΈΠΉ ΠΈ Π½Π°Π»ΠΈΡΠΈΡ ΡΡΠ΅Π½Π΄Π°. ΠΡΠΎΠ²Π΅ΡΠΊΠ° Π½Π° ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΠΎΡΡΡ ΠΎΡΡΡΠ΅ΡΡΠ²Π»ΡΠ»Π°ΡΡ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΡΠ΅ΡΡΠ° ΠΠ±Π±Π΅, Π½Π° ΡΠ»ΡΡΠ°ΠΉΠ½ΠΎΡΡΡ - ΠΊΡΠΈΡΠ΅ΡΠΈΠ΅ΠΌ ΠΠΈΡΠΌΠ΅Π½Π°, Π½Π° Π½Π°Π»ΠΈΡΠΈΠ΅ ΡΡΠ΅Π½Π΄Π° ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΠ»Π°ΡΡ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΊΡΠΈΡΠ΅ΡΠΈΡ ΠΈΠ½Π²Π΅ΡΡΠΈΠΉ. ΠΡΠ²ΠΎΠ΄ ΠΎ Π½Π΅ΡΠ»ΡΡΠ°ΠΉΠ½ΠΎΠΌ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΠΈΠ»ΠΈ Π½Π°ΡΡΡΠ΅Π½ΠΈΠΈ ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΠΎΡΡΠΈ ΡΡΠ΄ΠΎΠ² ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΎΠ²Π°Π» ΡΡΠ»ΠΎΠ²ΠΈΡ, ΠΊΠΎΠ³Π΄Π° ΡΠ°ΡΡΠ΅ΡΠ½Π°Ρ ΡΡΠ°ΡΠΈΡΡΠΈΠΊΠ° ΠΏΡΠ΅Π²ΡΡΠ°Π»Π° ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠ΅Π΅ ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠΈ ΡΡΠΎΠ²Π½Π΅ Π·Π½Π°ΡΠΈΠΌΠΎΡΡΠΈ 0,05. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΠΊΠ»ΠΈΠΌΠ°ΡΠ° ΡΠ΅Π²Π΅ΡΠ° ΠΠ°ΠΏΠ°Π΄Π½ΠΎΠΉ Π‘ΠΈΠ±ΠΈΡΠΈ ΠΈ Π΅Π³ΠΎ ΠΈΠ·ΠΌΠ΅Π½ΡΠΈΠ²ΠΎΡΡΡ Π² ΠΏΠΎΡΠ»Π΅Π΄Π½ΠΈΠ΅ Π³ΠΎΠ΄Ρ. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Ρ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π²ΠΎΠ·Π΄ΡΡ
Π° ΠΈ ΠΏΠΎΡΠ²ΠΎΠ³ΡΡΠ½ΡΠΎΠ² Π½Π° Π³Π»ΡΠ±ΠΈΠ½Π°Ρ
160 ΠΈ 320 ΡΠΌ, ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΡ ΠΏΡΡΠΌΠΎΠΉ ΡΠΎΠ»Π½Π΅ΡΠ½ΠΎΠΉ ΡΠ°Π΄ΠΈΠ°ΡΠΈΠΈ, ΡΡΠΌΠΌΡ Π°ΡΠΌΠΎΡΡΠ΅ΡΠ½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² ΠΈ Π²ΡΡΠΎΡΡ ΡΠ½Π΅ΠΆΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠΊΡΠΎΠ²Π° Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΈΠ½ΡΡΡΡΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΡ
Π΄Π°Π½Π½ΡΡ
Π·Π° ΠΏΠΎΡΠ»Π΅Π΄Π½ΠΈΠ΅ 35 Π»Π΅Ρ. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ ΡΠΎΡ
ΡΠ°Π½Π΅Π½ΠΈΠ΅ ΡΠ΅ΠΌΠΏΠΎΠ² ΡΠΎΡΡΠ° ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π²ΠΎΠ·Π΄ΡΡ
Π° Π² ΡΠ΅ΠΏΠ»ΠΎΠ΅ Π²ΡΠ΅ΠΌΡ Π³ΠΎΠ΄Π°, ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ ΠΏΠΎΡΠ²ΠΎΠ³ΡΡΠ½ΡΠΎΠ² Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ Π²ΡΠ΅Π³ΠΎ Π³ΠΎΠ΄Π°, Π²ΡΡΠ²Π»Π΅Π½ Π·ΠΎΠ½Π°Π»ΡΠ½ΡΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΡΠΌΠΌΡ Π°ΡΠΌΠΎΡΡΠ΅ΡΠ½ΡΡ
ΠΎΡΠ°Π΄ΠΊΠΎΠ² ΠΈ ΡΠ½Π΅ΠΆΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠΊΡΠΎΠ²Π°. ΠΠΈΠΊΡΠΎΠΊΠ»ΠΈΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ ΠΌΠ΅ΡΠ΅ΠΎΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
Π²Π΅Π»ΠΈΡΠΈΠ½ ΠΌΠΎΠ³ΡΡ ΠΈΡΠΊΠ°ΠΆΠ°ΡΡ ΡΠ΅Π°Π»ΡΠ½ΡΡ ΠΊΠ°ΡΡΠΈΠ½Ρ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΊΠ»ΠΈΠΌΠ°ΡΠ°.The relevance of the research is related to the necessity to assess climate changes affecting the permafrost due to the possible growth of greenhouse gas emissions and increase of accident rate in industrial, oil and gas infrastructure at permafrost thawing. The aim of the research is to estimate the current changes in climate characteristics, which affect directly the thermal state of soils in permafrost areas in the north of Western Siberia. Methods. Analysis of long-term changes of meteorological data consisted of tests of null hypothesis of randomness and homogeneity of observation series and trend presence. The homogeneity test was carried out using the Abbe test, the test of randomness was carried out by Pitman criterion, the trend presence was checked using the criterion of inversions. The conclusion on nonrandom change or violation of the homogeneity of rows corresponded to the condition, when the modulus of the estimated statistics exceeded the corresponding critical value at significance level of 0,05. Results. The paper considers the climatic features in the north of Western Siberia and its variability in recent years. The analysis of temperature changes of air and soil at depths of 160 and 320 cm, the amount of precipitation and snow cover based on the instrumental data for the last 35 years has shown that air temperature continues rising in the warmer months, soil temperature increases throughout the year. The authors have revealed zonal character of changes in the amount of precipitation and snow cover. Microclimatic changes in characteristic of meteorological values can distort the real picture of climate change
Suspension-adapted Chinese hamster ovary-derived cells expressing green fluorescent protein as a screening tool for biomaterials
Synthetic biomaterials play an important role in regenerative medicine. To be effective they must support cell attachment and proliferation in addition to being non-toxic and non-immunogenic. We used a suspension-adapted Chinese hamster ovary-derived cell line expressing green fluorescent protein (GFP) to assess cell attachment and growth on synthetic biomaterials by direct measurement of GFP-specific fluorescence. To simplify operations, all cell cultivation steps were performed in orbitally-shaken, disposable containers. Comparative studies between this GFP assay and previously established cell quantification assays demonstrated that this novel approach is suitable for rapid screening of a large number of samples. Furthermore the utility of our assay system was confirmed by evaluation of cell growth on three polyvinylidene fluoride polymer scaffolds that differed in pore diameter and drawing conditions. The data presented here prove the general utility of GFP-expressing cell lines and orbital shaking technology for the screening of biomaterials for tissue engineering application
Synthesis of RuO 2 nanowires from Ru thin films by atmospheric pressure micro-post-discharge
International audienceOxidation by a micro-post-discharge at atmospheric pressure of thin films of ruthenium deposited on fused silica by pressure-modulated magnetron sputtering is studied. Single-crystalline RuO 2 nanowires are obtained for the first time with a diffusion process over large areas. Nanowires grow typically at temperatures below 550-600 K, provided the level of stress is high enough to fragment grains in sub-grains with sizes between 30 and 50 nm. Because of the alternation of dense and porous layers forming the coating, inward diffusion of vacancies leads to no patent Kirkendall's effect, pores being distributed over the whole coating thickness and not mainly at the interface with the substrate. The centre of the treatment being heated at temperatures higher than 900 K, gaseous RuO 4 is formed, leading to an evaporated area. At its edge, a ring of microcrystals is formed, likely by a CVD mechanism
How Flies Are Flirting on the Fly
Background Flies have some of the most elaborate visual systems in the Insecta, often featuring large, sexually dimorphic eyes with specialized βbright zonesβ that may have a functional role during mate-seeking behavior. The fast visual system of flies is considered to be an adaptation in support of their advanced flight abilities. Here, we show that the immense processing speed of the fliesβ photoreceptors plays a crucial role in mate recognition.
Results Video-recording wing movements of abdomen-mounted common green bottle flies, Lucilia sericata, under direct light at 15,000 frames per second revealed that wing movements produce a single, reflected light flash per wing beat. Such light flashes were not evident when we video-recorded wing movements under diffuse light. Males of L. sericata are strongly attracted to wing flash frequencies of 178 Hz, which are characteristic of free-flying young females (prospective mates), significantly more than to 212, 235, or 266 Hz, characteristic of young males, old females, and old males, respectively. In the absence of phenotypic traits of female flies, and when given a choice between light emitting diodes that emitted either constant light or light pulsed at a frequency of 110, 178, 250, or 290 Hz, males show a strong preference for the 178-Hz pulsed light, which most closely approximates the wing beat frequency of prospective mates.
Conclusions We describe a previously unrecognized visual mate recognition system in L. sericata. The system depends upon the sex- and age-specific frequencies of light flashes reflecting off moving wings, and the ability of male flies to distinguish between the frequency of light flashes produced by rival males and prospective mates. Our findings imply that insect photoreceptors with fast processing speed may not only support agile flight with advanced maneuverability but may also play a supreme role in mate recognition. The low mating propensity of L. sericata males on cloudy days, when light flashes from the wings of flying females are absent, seems to indicate that these flies synchronize sexual communication with environmental conditions that optimize the conspicuousness of their communication signals, as predicted by sensory drive theory
Interaction of (3-Aminopropyl)triethoxysilane with Pulsed Ar-O 2 Afterglow: Application to Nanoparticles Synthesis
International audienceThe interaction of (3-Aminopropyl)triethoxysilane (APTES) with pulsed late Ar-O 2 afterglow is characterized by the synthesis of OH, CO and CO 2 in the gas phase as main by-products. Other minor species like CH, CN and C 2 H are also produced. We suggest that OH radicals are produced in a first step by dehydrogenation of APTES after interaction with oxygen atoms. In a second step, the molecule is oxidized by any O 2 state, to form peroxides that transform into by-products, break thus the precursor CC bonds. If oxidation is limited, i.e. a low duty cycle, fragmentation of the precursor is limited and produced nanoparticles keep the backbone structure of the precursor, but contain amide groups produced from the amine groups initially available in APTES. At high duty cycle, silicon-containing fragments contain some carbon and react together and produce nanoparticles with a non-silica-like structure
Multimodal and Multifunctional Signaling? β Web Reduction Courtship Behavior in a North American Population of the False Black Widow Spider
Males of widow spiders courting on the web of females engage in web-reduction behavior which entails excising a section of the web, bundling it up, and wrapping it with their silk. Males of the false black widow spider, Steatoda grossa, in European populations also produce stridulatory courtship sound which has not yet been studied in their invaded North American range. Working with a North American population of S. grossa, we tested the hypotheses that (1) web reduction by males renders webs less attractive to rival males; (2) deposition of silk by courting males has an inter-sexual (male-female) signal function that enhances their likelihood of copulation; and (3) stridulatory sound is a courtship signal of males. Testing anemotactic attraction of males in Y-tube olfactometer experiments revealed that reduced webs (indicative of a mated female) and intact webs (indicative of a virgin female) were equally attractive to males. Recording courtship behavior of males with either functional (silk-releasing) spinnerets or spinnerets experimentally occluded on the web of virgin females showed that males with functional spinnerets were more likely to copulate with the female they courted. Although males possess the stridulatory apparatus to produce courtship sound, they did not stridulate when courting or copulating on the web of females. Our data support the conclusion that web-reduction behavior of S. grossa males in their invaded North American range has no long-range effect on mate seeking males. Instead, web-reduction behavior has an inter-sexual signaling function that seems to be linked to functional spinnerets of the courting male. The signal produced by a male likely entails a volatile silk-borne pheromone, but may also embody a gauge of his endurance (the amount of time he engages in web reduction causing web vibrations)
Divergence in Dialogue
Copyright: 2014 Healey et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This work was supported by the Economic and Social Research Council (ESRC; http://www.esrc.ac.uk/) through the DynDial project (Dynamics of Conversational Dialogue, RES-062-23-0962) and the Engineering and Physical Sciences Research Council (EPSRC; http://www.epsrc.ac.uk/) through the RISER
project (Robust Incremental Semantic Resources for Dialogue, EP/J010383/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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