382 research outputs found

    On the origin of the Boson peak in globular proteins

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    We study the Boson Peak phenomenology experimentally observed in globular proteins by means of elastic network models. These models are suitable for an analytic treatment in the framework of Euclidean Random Matrix theory, whose predictions can be numerically tested on real proteins structures. We find that the emergence of the Boson Peak is strictly related to an intrinsic mechanical instability of the protein, in close similarity to what is thought to happen in glasses. The biological implications of this conclusion are also discussed by focusing on a representative case study.Comment: Proceedings of the X International Workshop on Disordered Systems, Molveno (2006

    Effect of different defoliants and application times on the yield and quality components of cotton in semi-arid conditions

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    This study was conducted to determine the effect of different defoliants (Dropp ultra® (DU): thidiazuron+diuron and Roundup (RU): glyphosate) and application times [60, 75 and 90 days after flowering (DAF)] on cotton. The research was carried out at the Harran University, Faculty of Agriculture Research and Application Center in 2001 and 2002 using cotton variety cv. Stoneville-453. Experiments were arranged as split plot design with three replications. Defoliations were at the main plots and application times at the subplots. Experimental plots were consisted of six rows, 10 m in length, interrow was 0.70 m and intra-row spacing was 0.20 m. The results of the study indicated that the application of DU defoliant at 60 days after flowering reduced seed cotton yield, number of bolls, boll weight and lint index. With this, seed cotton yield, number of bolls, boll weight and lint index increased with delayed defoliation time in both years. Also, there were no statistically significant differences between the treatments in terms of ginning outturn, fiber length, fiber strength and fiber fineness. It was also found that the application of 2000 cc ha-1 RU was not enough as a dose to affect leaf defoliation and other investigated components

    Mapping of QTLs for leaf area and the association with winter hardiness in fall-sown lentil

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    Variations in plant architecture are often associated with the ability of plants to survive cold stress during winter. In studies of winter hardiness in lentil, it appeared that small leaf area was associated with improved winter survival. Based on this observation, the inheritance of leaf area and the relationship with winter hardiness using an F6 - derived recombinant inbred line (RIL) population from the cross of WA8649090 x Precoz was investigated. The WA8649090 parent was winter hardy and had small leaves, while the Precoz parent was non-winter hardy and had large leaves. The 106 RILs and the parents were planted in a field in a randomized complete block design with three replications. Leaf area(cm2) of leaves from the fourth node was measured using a flatbed scanner and WinRHIZO software. Average leaf area for WA8649090 was 0.46 cm2, while leaf area for Precoz was 0.89 cm2. Average leaf area of the RILs was 0.63 cm2, and the frequency distribution was continuous, indicating the effects of more than one gene. Quantitative trait locus (QTL) analysis using a 130-point linkage map revealed one major QTL on linkage group 6 which explained 20.45% of the phenotypic variation for leaf area. The location of QTL for leaf area mapped the same region where one of the QTL for winter hardiness was mapped and significant association (r2 = 0.750, P< 0.01) was found between leaf area and winter hardiness. These results indicated an association between winter hardiness and leaf area that provides information applicable to lentil breeding.Keywords: Leaf area, lentil, recombinant inbred line (RIL), QTL mapping, winter hardines

    Diurnal gradual heat stress affects antioxidant enzymes, proline accumulation and some physiological components in cotton (Gossypium hirsutum L.)

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    Even though high temperatures significantly reduce both vegetative growth and yield in cotton, very little is known about the effects of heat stress on cotton antioxidant system. Thus, the effects of gradual heat stress on cotton growth in controlled conditions were investigated in the present study. At squaring stage, cotton plants were subjected to two different temperatures, 38 and 45°C to determine the influence of heat stress on the plants. The results of the present study showed that heat stress did not significantly altered the levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in the leaves, whereas there was a remarkable decline in proline quantity of the leaves of plants subjected to 45°C heat stress. As for the amount of total chlorophyll content, a slight increase at plants treated with 38°C temperature was observed. Furthermore, the activities of some enzymes such as superoxide dismutase (SOD), which were associated with heat stress response in other plants was also investigated. For example, there was decline in the activitity of SOD in the plants exposed to high temperatures. On the contrary, catalase (CAT) activity increased at 45°C; peroxidase (POX) activity increased at 38°C and ascorbate peroxidase (APX) activity increased at 38 and 45°C. The results from this study suggest a potential role for CAT, POX and APX in the reduction of elevated levels of H2O2 in cotton plants grown under heat stress condition. To sum up, it could be concluded that, diurnal gradual heat stress caused a low oxidative injury in cotton

    Effect of a Fatty Acid Additive on the Kinetic Friction and Stiction of Confined Liquid Lubricants

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    Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.The paper presents part of the research productions that accompanied the construction of bodies inserted in a Psychosocial Care Center for Alcohol and Other Drugs (CAPS-AD) of a city in the northern region of Brasil, focusing more sharply on masculinities arrangements. Special attention is given to the tension between normalized bodies and attempts at resistance and (re) exist. The argument is in the field of public health, particularly mental health, and rooted in gender and sexuality studies. The data production methodology made use of observations recorded in a diary, itinerant follow-up of a collective of research, interviews, focus groups where, among other things, was discussed diary topics, conversation circles and workshops. The attempt was to produce a way of collective narrating strategy, combining up experience and body (un)learn well as ways of producing health care and doing research

    Estimation of some stand parameters using digital aerial photographs for conservation and service oriented forests

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    Forest inventory, which is the first step of forest management planning, is the most difficult stage that requires much time and a lot of efforts. To reduce fieldworks that are considered time consuming and expensive methods of ground measurements, remote sensing data are widely used. Aerial photographs have been an integral part of forest inventory data in Turkey since 1963. Panchromatic and RGBI (Red, Green, Blue, Infrared) aerial photographs acquired by digital aerial cameras proved to be very important in forest inventory. They have maintained their importance for forest management planning process. The aim of this study is to construct a fast and practical inventory model that requires least fieldwork for forest management planning process. Pixel values and vegetation indices (NDVI, DVI, IPVI, RVI and PCA), obtained from remote sensing data, and stand parameters (stand volume, volume increment and number of trees) have been compared statistically. Black pine Pinus nigra J. F. Arnold plantations located in the south-east region of Turkey, Çelikhan Forest Planning Unit, was chosen as a research area. 0.5 meter spacing and 8 bit radiometric resolution Ultracam-X Digital Aerial Photos were used as remote sensing data. According to statistical analysis, IPVI and Green Band values provided the highest evaluation coefficient compared to the models developed for the estimation of stand parameters. Adjusted R square of stand volume, volume increment and the number of tree in the models were found to yield 0.74, 0.73 and 0.50 respectively. It was concluded that stand characteristics estimated by statistical models can be used for forest areas managed for conservation and service purposes

    Testing promising genes for pre-selection for drought tolerance in potato

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    30th International Horticultural Congress (IHC) / 2nd International Symposium on Root and Tuber Crops - Value Added Crops for the Next Generation -- AUG 12-16, 2018 -- Istanbul, TURKEYPotato (Solanum tuberosum L.) is sensitive to drought mainly due to its fibrous root system. With the global climate change, the yield loss in potato cultivation caused by drought is expected to reach 30% over the following years. A breeding approach to increase the tolerance of potato to drought stress requires a long time, quite laborious and expensive, mainly due to limitations in a controlled drought treatment in the field conditions, high heterozygosity nature of the plant and genotype x environment (GxE) interaction. A pre-selection in the laboratory for the promising drought tolerant lines is a requirement to disentangle these obstacles. However, the complexity and multigenic nature of the drought stress response mechanism restrains the identification of molecular markers to be used in pre-selection purposes. Here, we used a novel approach and investigated the possibility of using the gene expression under controlled conditions for pre-selection of drought tolerant potato cultivars. For this purpose, we analyzed next generation sequencing results of 'Unica' (tolerant) and 'Russet Burbank' (sensitive) potato cultivars to 23 days of drought treatment and selected genes with contrasting expression levels under stress/control conditions. Control expression levels of five promising genes [plastidial pyruvate kinase 4 (XM_006360110.1), cryptochrome-2 (XM_006354425.1), cytosolic L-ascorbate peroxidase 1 (XM_006366063.1), early responsive to dehydration 15 (HG975443.1) and GAST1 (XM_006338257.1)] were tested by RT-PCR approach in a different set of potato genotypes with defined drought tolerance index evaluated in an independent field drought experiment to test their efficiency in pre-selection of drought tolerance potential. Although the results indicated the potential of plastidial pyruvate kinase 4 for detecting tolerant potato genotypes, it appears that the differentiation of tolerance and sensitivity potential by a simple RT-PCR approach still requires investigation of a large set of genes together.Int Soc Hort SciScientific and Technological Research Council of Turkey (TUBITAK) [214O600]This project study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) with project number 214O600
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