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Search Results: 1 - 10 of 219337 matches for " C. Bressac "
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The effect of age on sperm stock and egg laying in the parasitoid wasp, Dinarmus basalis
D. Damiens,C. Bressac,C. Chevrier
Journal of Insect Science , 2003,
Abstract: Sperm quantity and quality during storage may be constraints acting on female fecundity and hence fitness. In Hymenoptera, the importance of sperm quality has rarely been considered, despite its central role in reproductive strategies and especially in sex ratio control. In these insects, fertilized eggs develop into females and unfertilized eggs into males. Experiments were conducted on the female wasp, Dinarmus basalis, in the laboratory with and without egg-laying resources (hosts). The first point was to test if sperm age influenced sperm storage by measuring sperm count and viability using a sperm viability test (SYBR-14 : propidium iodide). The second point was the influence of prolonged storage in the female genital tract on the quantity, sex ratio and fitness of offspring produced. Results show that sperm viability in the spermatheca does not change significantly with maternal age, and that the sperm stock is not affected when females are deprived of hosts. Egg-laying is gradually restored after 21 days of host deprivation but remains at a low level after 115 days. The fitness of mated D. basalis females is therefore not constrained by sperm quantity or quality and seems to depend on host availability and female age.
Impacts of dust deposition on dissolved trace metal concentrations (Mn, Al and Fe) during a mesocosm experiment
K. Wuttig, T. Wagener, M. Bressac, A. Dammsh user, P. Streu, C. Guieu,P. L. Croot
Biogeosciences (BG) & Discussions (BGD) , 2013, DOI: 10.5194/bg-10-2583-2013
Abstract: The deposition of atmospheric dust is the primary process supplying trace elements abundant in crustal rocks (e.g. Al, Mn and Fe) to the surface ocean. Upon deposition, the residence time in surface waters for each of these elements differs according to their chemical speciation and biological utilization. Presently, however, the chemical and physical processes occurring after atmospheric deposition are poorly constrained, principally because of the difficulty in following natural dust events in situ. In the present work we examined the temporal changes in the biogeochemistry of crustal metals (in particular Al, Mn and Fe) after an artificial dust deposition event. The experiment was contained inside trace metal clean mesocosms (0–12.5 m depths) deployed in the surface waters of the northwestern Mediterranean, close to the coast of Corsica within the frame of the DUNE project (a DUst experiment in a low Nutrient, low chlorophyll Ecosystem). Two consecutive artificial dust deposition events, each mimicking a wet deposition of 10 g m 2 of dust, were performed during the course of this DUNE-2 experiment. The changes in dissolved manganese (Mn), iron (Fe) and aluminum (Al) concentrations were followed immediately after the seeding with dust and over the following week. The Mn, Fe and Al inventories and loss or dissolution rates were determined. The evolution of the inventories after the two consecutive additions of dust showed distinct behaviors for dissolved Mn, Al and Fe. Even though the mixing conditions differed from one seeding to the other, Mn and Al showed clear increases directly after both seedings due to dissolution processes. Three days after the dust additions, Al concentrations decreased as a consequence of scavenging on sinking particles. Al appeared to be highly affected by the concentrations of biogenic particles, with an order of magnitude difference in its loss rates related to the increase of biomass after the addition of dust. In the case of dissolved Fe, it appears that the first dust addition resulted in a decrease as it was scavenged by sinking dust particles, whereas the second seeding induced dissolution of Fe from the dust particles due to the excess Fe binding ligand concentrations present at that time. This difference, which might be related to a change in Fe binding ligand concentration in the mesocosms, highlights the complex processes that control the solubility of Fe. Based on the inventories at the mesocosm scale, the estimations of the fractional solubility of metals from dust particles in seawater were 1.44 ± 0.19% and 0.91 ± 0.83% for Al and 41 ± 9% and 27 ± 19% for Mn for the first and the second dust addition. These values are in good agreement with laboratory-based estimates. For Fe no fractional solubility was obtained after the first seeding, but 0.12 ± 0.03% was estimated after the second seeding. Overall, the trace metal dataset presented here makes a significant contribution to enhancing our knowledge on th
Impacts of dust deposition on dissolved trace metal concentrations (Mn, Al and Fe) during a mesocosm experiment
K. Wuttig,T. Wagener,M. Bressac,A. Dammsh?user
Biogeosciences Discussions , 2012, DOI: 10.5194/bgd-9-13857-2012
Abstract: The deposition of atmospheric dust is the primary process supplying trace elements abundant in crustal rocks (e.g. Al, Mn and Fe) to the surface ocean. Upon deposition, the residence time in surface waters for each of these elements differs according to their chemical speciation and biological utilization. Presently however their behavior after atmospheric deposition is poorly constrained, principally because of the difficulty in following natural dust events in-situ. In the present work we examined the temporal changes in the biogeochemistry of crustal metals (in particular Al, Mn and Fe) after an artificial dust deposition event. The experiment was contained inside trace metal clean mesocosms (0–12.5 m depths) deployed in the surface waters of the Northwestern Mediterranean, close to the coast of Corsica in the frame of the DUNE project (a DUst experiment in a low Nutrient low chlorophyll Ecosystem). Two consecutive artificial dust deposition events, each mimicking a wet deposition of 10 g m 2 of dust, were performed during the course of this DUNE-2 experiment. The changes in dissolved manganese (dMn), iron (dFe) and aluminium (dAl) concentrations were followed immediately and over the following week and their inventories and loss or dissolution rates were determined. The evolution of the inventories after the two consecutive additions of dust showed distinct behaviors for dMn, dAl and dFe. Even though the mixing conditions differed from one seeding to the other, dMn and dAl showed clear increases directly after both seedings due to dissolution processes. Three days after the dust additions, dAl concentrations decreased as a consequence of scavenging on sinking particles. dAl appeared to be highly affected by the concentrations of biogenic particles, with an order of magnitude difference in its loss rates related to the increase of biomass after the addition of dust. For dFe concentrations, the first dust addition decreased the concentrations through scavenging of the dust particles, whereas the second seeding induced dissolution of Fe from the dust particles. This difference, which might be related to a change in Fe-binding ligand concentration in the mesocosms, highlights the complex processes that control the solubility of Fe. Based on the inventories at the mesocosm scale, the estimations of solubility of metals from dust particles in seawater were 1% for Al and 40% for Mn which were in good agreement with laboratory based estimates. Overall, the trace metal dataset presented here makes a significant contribution to enhancing our knowledge on the
Nuclear Importation of Mariner Transposases among Eukaryotes: Motif Requirements and Homo-Protein Interactions
Marie-Véronique Demattei, Sabah Hedhili, Ludivine Sinzelle, Christophe Bressac, Sophie Casteret, Nathalie Moiré, Jeanne Cambefort, Xavier Thomas, Nicolas Pollet, Pascal Gantet, Yves Bigot
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023693
Abstract: Mariner-like elements (MLEs) are widespread transposable elements in animal genomes. They have been divided into at least five sub-families with differing host ranges. We investigated whether the ability of transposases encoded by Mos1, Himar1 and Mcmar1 to be actively imported into nuclei varies between host belonging to different eukaryotic taxa. Our findings demonstrate that nuclear importation could restrict the host range of some MLEs in certain eukaryotic lineages, depending on their expression level. We then focused on the nuclear localization signal (NLS) in these proteins, and showed that the first 175 N-terminal residues in the three transposases were required for nuclear importation. We found that two components are involved in the nuclear importation of the Mos1 transposase: an SV40 NLS-like motif (position: aa 168 to 174), and a dimerization sub-domain located within the first 80 residues. Sequence analyses revealed that the dimerization moiety is conserved among MLE transposases, but the Himar1 and Mcmar1 transposases do not contain any conserved NLS motif. This suggests that other NLS-like motifs must intervene in these proteins. Finally, we showed that the over-expression of the Mos1 transposase prevents its nuclear importation in HeLa cells, due to the assembly of transposase aggregates in the cytoplasm.
ВПЛИВ Х М ЧНОГО СКЛАДУ НА ТИСК НАСИЧЕНО ПАРИ В МОТОРНИХ Б ОЛОГ ЧНИХ ПАЛИВАХ The influence of chemical composition on the saturated vapor pressure in biological motor fuels Влияние химического состава на давление насыщенного пара в моторных биологических топливах
?.В. Полунк?н,C.О. Зубенко,О.О. Гайдай,А.В. Струнгар
Proceedings of National Aviation University , 2010,
Abstract: Розглянуто вплив випаровуваност альтернативних палив на р шення проблеми холодного пуску двигуна за рахунок використання пропан-бутаново сум ш для п двищення тиску насичено пари. Volatility fuels fraction of the estimated parameters and letkosti. Volatility characterizes the ability to switch fuels in vaporous state. Selecting indicators to assess the volatility depends on the chemical composition of fuel. The main measure letkosti etanolnogo fuel is vapor pressure. The most simple and cost-effective to improve cold start is putting in fuel lehkoletyuchyh components: butane, izopentanu, gas and other petroleum. It was investigated the influence of DEE on alcohol-gasoline blend, the results show that DEE positive impact on increasing vapor pressure to the desired minimum for starting the engine. But because the ether to 19%, then at such high levels can actively formed peroxide compounds, which is undesirable. Very promising is the use of propane-butane gas mixture as lehkoletyuchoyi gaseous component. Butanizovani spirit-petrol mixture can be recommended for use as alternative fuel vehicles after further study of their stability and himmotolohichnyh characteristics. Автомобильные бензины и альтернативные биологические топлива на основе этанола преимущественно предназначены для применения в двигателях внутреннего сгорания. При использовании альтернативного биологического топлива, особенно этанольного, возникает проблема недостаточной испаряемости бензина при низкой температуре, в результате чего в холодное время года двигатель может не запуститься. Пусковые свойства бензина зависят от содержания в них летучих фракций или летучих соединений. Проблему холодного запуска предлагается решать за счет использования пропан-бутановой смеси для повышения давления насыщенного пара. Для перспективного применения газов пропан-бутановой смеси легколетучего газообразного компонента необходимы дальнейшие исследования стабилизации такой композиции.
Strategic trends of development of the Lithuanian aviation in the light of Euro-integration processes Стратегические направления развития авиации литвы в свете евроинтеграции процессов СТРАТЕГ ЧНИЙ НАПРЯМ РОЗВИТКУ АВ АЦ ЛИТВИ У СВ ТЛИ ВРО НТЕГРАЦ ЙНИХ ПРОЦЕС В
Й. Станкунаc
Proceedings of National Aviation University , 2004,
Abstract: The factors having an effect on the system of air transport in the Republic of Lithuania in connection with Lithuania’s membership in the European Union are discussed. The structure of the system of air transport of the country is presented, an analysis of the current situation and a strategic analysis of the development of the system is made, and the measures addressed at the long-range perspective are proposed. Рассмотрены факторы, действующие в системе воздушного транспорта Литовской Республики после вступления в Европейский Союз. Приведена структура системы воздушного транспорта страны и выполнен стратегический анализ развития транспортной системы на долгосрочную перспективу. Розглянуто чинники, що д ють у систем пов тряного транспорту Литовсько Республ ки п сля вступу в вропейський Союз. Подано структуру систем пов тряного транспорту кра ни та виконано стратег чний анал з розвитку транспортно системи на довгострокову перспективу.
LIMIT DISTRIBUTION OF A RANK OF RANDOM SATURATED MATRIX ABOVE A FIELD GF(2) ПРЕДЕЛЬНОЕ РАСПРЕДЕЛЕНИЕ РАНГА СИЛЬНОЗАПОЛНЕННОЙ СЛУЧАЙНОЙ МАТРИЦЫ НАД ПОЛЕМ GF(2) ГРАНИЧНИЙ РОЗПОД Л РАНГУ СИЛЬНОЗАПОВНЕНО ВИПАДКОВО МАТРИЦ В ПОЛ GF(2)
C.В. Поперешняк
Proceedings of National Aviation University , 2012,
Abstract: In this paper a theorem on the asymptotic distribution of rank of random matrices in the field GF (2) of independent random -D lines, the absence in it of unity lines and the assumption that the difference between the number of rows and number of columns of the matrix is a fixed number of random characters, . Получена теорема про асимптотику распределения ранга случайной матрицы над полем GF(2), которая состоит из независимых случайных -мерных строк, при условии отсутствия в ней единичных линий и в предположении, что разница между числом строк и числом столбцов матрицы фиксированное число произвольного знака, . Отримано теорему про асимптотику розпод лу рангу випадково матриц в пол GF(2) з незалежних випадкових -вим рних рядк в за умови в дсутност в н й одиничних л н й та в припущенн , що р зниця м ж числом рядк в та числом стовпц в матриц ф ксоване число дов льного знаку,
TEACHING IN THE CONDITIONS OF INFORMATIVE-EDUCATIONAL SPACE OF DIGITAL SCHOOL НАВЧАННЯ В УМОВАХ НФОРМАЦ ЙНО-ОСВ ТНЬОГО ПРОСТОРУ ЦИФРОВО ШКОЛИ
?.М. Cмирнова-Трибульска
Information Technologies and Learning Tools , 2010,
Abstract: In the article basic descriptions of teaching in the conditions of informative-educational environment of school of a new structure are considered – digital taking into account the personality-oriented paradigm of education; the example of the use of school as a Multicenter is represented, the substantive provisions of the European project of eEurope 2010 are analyzed, touching informatizations of education, in particular schools which it is possible to examine as a model of near future. У статт розглянут основн характеристики навчання в умовах нформац йно-осв тнього простору школи ново формац – цифрово з врахуванням особист сно-ор нтовано парадигми осв ти; поданий приклад використання школи як Мультицентру, проанал зован основн положення вропейського проекту eEurope 2010, що стосуються нформатизац осв ти та зокрема шк л, як можна розглядати як модел недалекого майбутнього.
THE CREATION OF AUTHORITATIVE FILE NAMED THE COLLECTIVE AUTHOR ON THE BASE OF ABIS IRBIS FOR THE ELECTRONIC CATALOGUE OF V. SUKHOMLYNSKY STATE PEDAGOGICAL SCIENCE LIBRARY OF UKRAINE СТВОРЕННЯ АВТОРИТЕТНОГО ФАЙЛУ КОЛЕКТИВНИЙ АВТОР НА БАЗ АБ С РБ С ДЛЯ ЕЛЕКТРОННОГО КАТАЛОГУ ДЕРЖАВНО НАУКОВО-ПЕДАГОГ ЧНО Б БЛ ОТЕКИ УКРА НИ МЕН В. О. СУХОМЛИНСЬКОГО
C. Коваленко,Р. Гаврилюк
Information Technologies and Learning Tools , 2010,
Abstract: У пер од створення електронного каталогу в ДНПБ Укра ни м. В. О. Сухомлинського актуальним питання ведення авторитетного файлу заголовк в колективного автора. Дана стаття присвячена стор виток в авторитетного контролю, технолог створення авторитетного файлу Колективний автор (АФ КА ), а також проблемам, як виникають у ход створення та ведення АФ КА . In the period of creation of electronic catalogue in V. Sukhomlynsky state pedagogical science library of Ukraine the question of conducting of authoritative file of titles of collective author is actual. The given article is devoted to the history of sources of authoritative control, technology of creation of authoritative file Collective author and also to the problems which arise up during the creation and conducting of the file.
AUTOMATION OF DOCUMENTS PROCESSING IN THE INFORMATION SYSTEM OF RESEARCH PLANNING IN NATIONAL ACADEMY OF PEDAGOGICAL SCIENCES OF UKRAINE АВТОМАТИЗАЦ Я ОБРОБКИ ДОКУМЕНТ В В НФОРМАЦ ЙН Й СИСТЕМ ПЛАНУВАННЯ НАУКОВИХ ДОСЛ ДЖЕНЬ В НАЦ ОНАЛЬН Й АКАДЕМ ПЕДАГОГ ЧНИХ НАУК УКРА НИ
C.М. Тукало
Information Technologies and Learning Tools , 2011,
Abstract: The material presented in the article is relevant because of the need of modern information technologies introduction in the document flow in the process of researches planning in NAPS of Ukraine to increase their effectiveness, coordination and organization. The article suggests a method of forming and processing of documents in an integrated environment of Windows SharePoint Services — Microsoft Word, through which the Institute of Information Technologies and Learning Tools of NAPS of Ukraine is designing an information system Research planning in NAPS Ukraine based on the Internet 0109U002139. Матер али, викладен у статт , актуальними у зв’язку з необх дн стю впровадження сучасних нформац йних технолог й у процеси документооб гу стосовно процес в планування наукових досл джень в НАПН Укра ни з метою п двищення ефективност х, координац та орган зац . У статт запропоновано метод формування й обробки документ в в нтегрованому середовищ Windows SharePoint Services — Microsoft Word, на основ якого нститутом нформац йних сиcтем засоб в навчання зд йсню ться проектування нформац йно системи Планування наукових досл джень в НАПН Укра ни на баз мереж нтернет д. р. 0109U002139.
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