45,711 research outputs found
Increased duplex stabilization in porphyrin-LNA zipper arrays with structure dependent exciton coupling
Data files containing the melting curves of modified DNA, and fitting procedures to extract thermodynamic data.
This dataset was used in:
Singleton DG, Hussain R, Siligardi G, Kumar P, Hrdlicka PJ, Berova N and Stulz E (2015) Increased duplex stabilization in porphyrin-LNA zipper arrays with structure dependent exciton coupling. Organic & Biomolecular Chemistry, DOI: 10.1039/C5OB01681A </span
Porphyrin substituted DNA: building blocks for novel nanostructures
Porphyrin-modified DNA duplexes have been studied in detail for the last 10 years. It is well known that G-rich DNA sequences of the type (GGGX)4 can form stable intramolecular quadruplex structures containing stacks of G quartets in the presence of monovalent cations such as potassium. The synthesis of novel G-quadruplex forming DNA sequences based on the human telomeric repeat (GGGTTA)x where porphyrins are covalently attached to thymidine is presented. It is shown that the porphyrin modification offers a large degree of stabilisation to the G-quadruplex. Structural studies have revealed that the porphyrin modification does not bias the formation of a single G quadruplex. However, one exception was observed for a G quadruplex with two porphyrin modifications. Further insight into the interactions between the porphyrin and the G-quadruplex were achieved by molecular dynamic simulations. The synthesis of novel porphyrin-modified locked nucleic acids (LNA) is presented. It was hoped that the LNA modification would provide stability to the porphyrin-modified DNA duplex as porphyrin modifications have previously been found to destabilise duplex DNA. The structure and stability of the DNA was assessed in detail using circular dichroism spectroscopy. Finally, a new method of synthesising porphyrin-modified DNA using polymerases to incorporate porphyrin triphosphates into oligonucleotides is presented. The synthesis of novel porphyrin triphosphates is described. A variety of polymerases were assessed on whether they could incorporate these triphosphates into oligonucleotides. Multiple incorporations of these porphyrin-modified triphosphates showed that they were a good substrate for certain polymerases and with further development this method could be a viable route to synthesis of porphyrin-modified DNA
Implementation Of Various Types Of Fuzzy Controls On A Mobile Robot Using Sonar Sensors [QA9.64. N438 2008 f rb].
Dalam penyelidikan ini, sebuah robot bergerak telah digunakan untuk mengimplementasikan kawalan fuzzy jenis ‘Non-Singleton Type-2’ untuk kawalan pergerakan pengemudian dan tepian dinding dengan bantuan penderia sonar.
In this work, non-singleton type-2 fuzzy control has been implemented on a mobile robot for steering and sidewall movement control with the aid of ultrasonic sensors to compare its performances with the singleton type-2 and type-1 fuzzy control
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Biology and management of rodent communities in complex agroecosystems – lowlands
Acyclicity and singleton cores in matching markets
This paper analyzes the role of acyclicity in singleton cores. We show that the absence of simultaneous cycles is a sufficient condition for the existence of singleton cores. Furthermore, acyclicity in the preferences of either side of the market is a minimal condition that guarantees the existence of singleton cores. If firms or workers preferences are acyclical, unique stable matching is obtained through a procedure that resembles a serial dictatorship. Thus, acyclicity generalizes the notion of common preferences. It follows that if the firms or workers preferences are acyclical, unique stable matching is strongly efficient for the other side of the marketStable matching, Acyclicity, Singleton cores
Can social behaviour influence food preference of wild mice, Mus domesticus, in confined field population?
The impact of predator-induced stress on the snowshoe hare cycle
The sublethal effects of high predation risk on both prey behavior and physiology may have long-term consequences for prey population dynamics. We tested the hypothesis that snowshoe hares during the population decline are chronically stressed because of high predation risk whereas those during the population low are not, and that this has negative effects on both their physiology and demography. Snowshoe hares exhibit 10- yr population cycles; during declines, virtually every hare that dies is killed by a predator. We assessed the physiological responsiveness of the stress axis and of energy mobilization by subjecting hares during the population decline and low to a hormonal-challenge protocol. We monitored the population demography through live-trapping and assessed reproduction through a maternal-cage technique. During the 1990s’ decline in the Yukon, Canada, hares were chronically stressed—as indicated by higher levels of free cortisol, reduced maximum corticosteroid-binding capacity, reduced testosterone response, reduced index of body condition, reduced leucocyte counts, increased overwinter body-mass loss, and increased glucose mobilization, relative to hares during the population low. This evidence is consistent with the explanation that predation risk, not high hare density or poor nutritional condition, accounted for the chronic stress and for the marked deterioration of reproduction during the decline. Reproduction and indices of stress physiology did not improve until predation risk declined. These findings may also account for the lag in recovery of hare reproduction after predator densities have declined and thus may implicate the long-term consequences of predation risk on prey populations beyond the immediate effects of predators on prey behavior and physiology
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Biology and management of rodent communities in complex agroecosystems – rice terraces
Impact of periconceptional nutrition on maternal and fetal leptin and fetal adiposity in singleton and twin pregnancies
It has been proposed that maternal nutrient restriction may alter the functional development of the adipocyte and the synthesis and secretion of the adipocyte-derived hormone, leptin, before birth. We have investigated the effects of restricted periconceptional undernutrition and/or restricted gestational nutrition on fetal plasma leptin concentrations and fetal adiposity in late gestation. There was no effect of either restricted periconceptional or gestational nutrition on maternal or fetal plasma leptin concentrations in singleton or twin pregnancies during late gestation. In ewes carrying twins, but not singletons, maternal plasma leptin concentrations in late gestation were directly related to the change in ewe weight that occurred during the 60 days before mating [maternal leptin = 0.9 (change in ewe weight) + 7.8; r = 0.6, P < 0.05]. In twin, but not singleton, pregnancies, there was also a significant relationship between maternal and fetal leptin concentrations (maternal leptin = 0.5 fetal leptin + 4.2, r = 0.63, P < 0.005). The relative mass of perirenal fat was also significantly increased in twin fetal sheep in the control-restricted group (6.0 +/- 0.5) compared with the other nutritional groups (control-control: 4.1 +/- 0.4; restricted-restricted: 4.4 +/- 0.4; restricted-control: 4.3 +/- 0.3). In conclusion, the impact of maternal undernutrition on maternal plasma leptin concentrations during late gestation is dependent on fetal number. Furthermore, we have found that there is an increased fetal adiposity in the twins of ewes that experienced restricted nutrition throughout gestation, and this may be important in the programming of postnatal adiposity
The dialogue between the author and the hero in the “Notes” of G. R. Derzhavin
В центре внимания автора статьи «Записки» Г. Р. Державина, представляющие по своей сути его автобиографию. Труд этот был создан на закате жизни, он включает все важнейшие события жизни Г. Р. Державина, поэта и государственного деятеля. Рассказ ведется от третьего лица, что придает особую атмосферу повествованию, выстраивается своеобразный диалог между автором и героем, все это и является предметом исследования автора статьи.The focus of the author of the article “Notes” G. R. Derzhavin, representing in essence his autobiography. This work was created at the end of his life; it includes all the most important events in the life of G. R. Derzhavin, poet and statesman. The story is told in a third person, which gives a special atmosphere to the story, a certain dialogue emerges between the author and the hero, all this is the subject of the author's research
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