60 research outputs found
Nucleotide diversity maps reveal variation in diversity among wheat genomes and chromosomes
<p>Abstract</p> <p>Background</p> <p>A genome-wide assessment of nucleotide diversity in a polyploid species must minimize the inclusion of homoeologous sequences into diversity estimates and reliably allocate individual haplotypes into their respective genomes. The same requirements complicate the development and deployment of single nucleotide polymorphism (SNP) markers in polyploid species. We report here a strategy that satisfies these requirements and deploy it in the sequencing of genes in cultivated hexaploid wheat (<it>Triticum aestivum</it>, genomes AABBDD) and wild tetraploid wheat (<it>Triticum turgidum </it>ssp. <it>dicoccoides</it>, genomes AABB) from the putative site of wheat domestication in Turkey. Data are used to assess the distribution of diversity among and within wheat genomes and to develop a panel of SNP markers for polyploid wheat.</p> <p>Results</p> <p>Nucleotide diversity was estimated in 2114 wheat genes and was similar between the A and B genomes and reduced in the D genome. Within a genome, diversity was diminished on some chromosomes. Low diversity was always accompanied by an excess of rare alleles. A total of 5,471 SNPs was discovered in 1791 wheat genes. Totals of 1,271, 1,218, and 2,203 SNPs were discovered in 488, 463, and 641 genes of wheat putative diploid ancestors, <it>T. urartu</it>, <it>Aegilops speltoides</it>, and <it>Ae. tauschii</it>, respectively. A public database containing genome-specific primers, SNPs, and other information was constructed. A total of 987 genes with nucleotide diversity estimated in one or more of the wheat genomes was placed on an <it>Ae. tauschii </it>genetic map, and the map was superimposed on wheat deletion-bin maps. The agreement between the maps was assessed.</p> <p>Conclusions</p> <p>In a young polyploid, exemplified by <it>T. aestivum</it>, ancestral species are the primary source of genetic diversity. Low effective recombination due to self-pollination and a genetic mechanism precluding homoeologous chromosome pairing during polyploid meiosis can lead to the loss of diversity from large chromosomal regions. The net effect of these factors in <it>T. aestivum </it>is large variation in diversity among genomes and chromosomes, which impacts the development of SNP markers and their practical utility. Accumulation of new mutations in older polyploid species, such as wild emmer, results in increased diversity and its more uniform distribution across the genome.</p
Preferential Amplification of CD8 Effector-T Cells after Transcutaneous Application of an Inactivated Influenza Vaccine: A Randomized Phase I Trial
Background: Current conventional vaccination approaches do not induce potent CD8 T-cell responses for fighting mostly variable viral diseases such as influenza, avian influenza viruses or HIV. Following our recent study on vaccine penetration by targeting of vaccine to human hair follicular ducts surrounded by Langerhans cells, we tested in the first randomized Phase-Ia trial based on hair follicle penetration (namely transcutaneous route) the induction of virus-specific CD8 T cell responses. Methods and Findings: We chose the inactivated influenza vaccine – a conventional licensed tetanus/influenza (TETAGRIP®) vaccine – to compare the safety and immunogenicity of transcutaneous (TC) versus IM immunization in two randomized controlled, multi-center Phase I trials including 24 healthy-volunteers and 12 HIV-infected patients. Vaccination was performed by application of inactivated influenza vaccine according to a standard protocol allowing the opening of the hair duct for the TC route or needle-injection for the IM route. We demonstrated that the safety of the two routes was similar. We showed the superiority of TC application, but not the IM route, to induce a significant increase in influenza-specific CD8 cytokine-producing cells in healthy-volunteers and in HIV-infected patients. However, these routes did not differ significantly for the induction of influenza-specific CD4 responses, and neutralizing antibodies were induced only by the IM route. The CD8 cell response is thus the major immune response observed after TC vaccination. Conclusions: This Phase Ia clinical trial (Manon05) testing an anti-influenza vaccine demonstrated that vaccines designed for antibody induction by the IM route, generate vaccine-specific CD8 T cells when administered transcutaneously. These results underline the necessity of adapting vaccination strategies to control complex infectious diseases when CD8 cellular responses are crucial. Our work opens up a key area for the development of preventive and therapeutic vaccines for diseases in which CD8 cells play a crucial role
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Analysis of the influence of the variation of basic physical parameters of insulating materials on penetrating heat through the building baffle
Zagadnienia ochrony środowiska od lat koncentrują się na oszczędnościach energii użytkowanej w okresach jesienno-zimowych zużywanej na ogrzewanie budynków. Restrykcyjne wymogi przepisów prawnych wymagają od projektantów, aby przegrody obiektów posiadały odpowiednie parametry izolacyjności termicznej, a stosowane urządzenia grzewcze posiadały wysokie parametry wydajności. Celem tych działań jest z jednej strony zmniejszenie zużycia ilości paliw naturalnych, których zasoby są ograniczone z drugiej zaś zmniejszenie emisji powstałych odpadów spalania wydzielanych do atmosfery. Stosunkowo nowym zagadnieniem, które związane jest ze zmieniającym się klimatem są poszukiwania oszczędności energii użytkowanej na ochronę przed gorącem w okresach letnich. Zmieniający się klimat, wzrost temperatur panujących latem oraz podniesienie standardów życia sprawiły, że stosowanie elektrycznych klimatyzatorów jest zjawiskiem codziennym. W skali globalnej zwiększenie zużycia energii elektrycznej, która jest wciąż produkowana w dużej mierze w elektrociepłowniach finalnie ma identyczny wpływ na środowisko jak efekty ogrzewania. Z powodów powyższych prowadzi się prace badawcze, których celem jest poprawa izolacyjności termicznej przegród przed wysokimi temperaturami w okresach letnich. Celem badań przedstawionych w niniejszym artykule była ocena wpływu zmienności podstawowych parametrów fizycznych materiałów izolacyjnych takich jak gęstość oraz wilgotność na możliwość przepływu ciepła przez przegrodę budowlaną w warunkach symulujących nagrzewanie jej powierzchni w okresie letnim. Do badań wykorzystano stanowisko badawcze zachowania się materiałów budowlanych w wysokich temperaturach. Badaniom poddano materiały budowlane takie jak styropian, wełna mineralna, beton komórkowy oraz ceramikę porowatą. Z wymienionych materiałów wykonano modele laboratoryjne przegród budowlanych. Symulację nagrzewania powierzchni przegrody prowadzono przy pomocy nagrzewnicy technicznej, która nagrzewała jej powierzchnie do temperatury 1000C. Na przeciwległej stronie przegrody obserwowano temperaturę przy pomocy termometru elektronicznego. Parametrem poddawanym ocenie była zmienność temperatury w czasie nagrzewania. Wyniki badań wskazały, jaki wpływ na przepływ ciepła przez przegrodę mają zawilgocenie i gęstość materiałów stosowanych do jej budowy.Environmental issues have been focused on energy savings during the autumn and winter months for heating buildings. Restrictive regulatory requirements require designers to ensure that the building’s baffles have adequate thermal insulation and that the heating appliances used have high performance parameters. On the one hand, the aim of these measures is to reduce the consumption of the amount of natural fuels whose resources are limited and, on the other, to reduce the emission of combustion waste released into the atmosphere. A relatively new issue that is related to changing climate is the search for energy savings for heat protection in summer. The changing climate, rising temperatures in the summer and raising standards of living have made the use of electric air conditioners a daily phenomenon. On a global scale, increased electricity consumption, which is still being produced on a large scale in combined heat and power plants, has the same environmental impact as heating. For these reasons, extensive research is underway to improve the thermal insulation of the partitions against high summer temperatures. The purpose of the research presented in this article was to assess the influence of the variability of basic physical parameters of insulation materials on the possibility of penetrating heat through the building envelope under conditions simulating the heating of its surface in the summer. The research was carried out on the behavior of building materials at high temperatures. Construction materials such as polystyrene, mineral wool, cellular concrete and porous ceramics were tested. These materials were imitated laboratory of building partitions. Simulation of the heating of the partition surface was carried out with the aid of a technical dryer, which heated its surfaces to a temperature of 100ºC. On the opposite side of the barrier, the temperature was measured with an electronic thermometer. The parameter being evaluated is the temperature variation during heating. The results of the tests indicated the physical parameters of the insulating materials, which influence the possibility of penetrating the heat through the septum
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