45,906 research outputs found
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Fluorescence Resonance Energy Transfer Techniques to Study Ligand-Mediated Interactions of PPARs with Coregulators
No full textThe capacity to induce the association of peroxisome proliferator-activated receptors (PPARs) with different transcriptional coregulators is determined by the peculiar 3D-structure that the receptors adopt when bound with a specific ligand. The fluorescence resonance energy transfer assay is a technique widely used to evaluate coregulator recruitment to nuclear receptors induced by ligands. With this assay it is possible to quantitatively determine the interaction and the affinity of coregulators with PPARs when these receptors are complexed with ligands. Here, we describe the use of this technique to assess the preferential interaction and the affinity of PPARγ with coregulators as a function of the chemical structure of the bound ligan
Improving nitrogen use efficiency in melon by grafting
No full textIdentification of rootstocks capable of improving the nitrogen use efficiency
(NUE) of the scion could reduce N fertilization and nitrate leaching; however, screening
different graft combinations under field conditions can be costly and time-consuming. This
study evaluated a rapid and economicalmethodology for screening of melon rootstocks for
NUE. Two experiments were designed. In the first, melon plants (Cucumis melo L. cv.
Proteo) either ungrafted or grafted onto four commercial rootstocks: ‘Dinero’ and ‘Jador’
(Cucumis melo L.), ‘P360’, and ‘PS1313’ (Cucurbita maxima Duchesne · Cucurbita
moschata Duchesne) grown in hydroponics were compared in terms of shoot dry biomass,
leaf area, root-to-shoot ratio, SPAD index, shoot N uptake, and nitrate reductase (NR)
activity at the early developmental stage in response to nitrate availability (0.5, 2.5, 5, 10, or
15mM of NO3
–). The second experiment was aimed to confirmwhether the use of a selected
rootstock with high NUE (‘P360’) could improve crop performance and NUE of grafted
melon plants under field conditions. In the first experiment, carried out under greenhouse
conditions, melon plants grafted onto ‘Dinero’, ‘Jador’, and ‘P360’ rootstocks needed 5.7,
5.2, and 6.1 mM of NO3
–, respectively, to reach half-maximum shoot dry weight, whereas
plants grafted onto ‘PS1313’ rootstock and the control treatment (ungrafted plants)
needed 9.1 and 13.1 mM of NO3
–, respectively. Total leaf area, SPAD index, and shoot N
uptake increased linearly and quadratically in response to an increase of the N
concentration in the nutrient solution. At 2.5 mM of NO3
–, melon plants grafted onto both
C. melo and Cucurbita maxima · Cucurbita moschata rootstocks had the highest NR
activity, whereas no significant difference was observed at 10 mM of NO3
–. In the second
experiment, carried out under open field conditions, increasing the N fertilization rates
from 0 to 120 kgha–1 increased the total and marketable yields of melon plants, whereas
the NUE decreased. When averaged over N levels, the marketable yield, NUE, and N
uptake efficiency were higher by 9%, 11.8%, and 16.3%, respectively, in ‘Proteo’ grafted
onto ‘P360’ than in ungrafted ‘Proteo’ plants
Estimation of leaf number of eggplant using thermal time model
No full textA two-year investigation was carried out during 2006 (on three cultivars) and 2007 (on one cultivar) under open-field conditions, respectively, to test whether a model based on the thermal time approach could be developed to estimate the leaf number of eggplant (Solanum melongena L.) across cultivars. Thermal time (°Cd) was calculated using a base temperature of 11°C and a ceiling temperature of 32°C. Leaves that were beginning to unfold with a width of 2 cm or greater were counted every 3 to 4 days. A relationship between the leaf number and the thermal time was established in the calibration experiment (2006) on three cultivars, and data from another cultivar in 2007 growing season was used for model validation. Results indicated that a single equation could be used to predict leaf number of all cultivars in response to thermal time. The response of the leaf numbers to thermal time was curvilinear, with a lag over the first 450°Cd. After 450°Cd, the increase in the leaf number per plant was linearly related to the thermal time. These results would be useful in developing a model of leaf area development and eventually a crop growth model for eggplant
Site-Directed Mutagenesis to Study the Role of Specific Amino Acids in the Ligand Binding Domain of PPARs
No full textThe role of certain amino acids in the interactions of ligands with their cognate nuclear receptors is usually achieved by the resolution of the crystal structure of the receptor complexed with the ligand. As a complementary functional approach, site-directed mutagenesis, a technique broadly used in molecular biology, allows the assessment of the role of a specific amino acid in determining the interaction with a specific ligand. This method makes it possible to evaluate several mutations of a key amino acid for ligand binding and to determine the relationship between protein structure and ligand interaction. Here, we describe an application of this technique to evaluate different point mutations on the transcriptional activity of peroxisome proliferator-activated receptor γ (PPARγ) in the absence or presence of chemically different ligand
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
Synergistic biostimulatory action: Designing the next generation of plant biostimulants for sustainable agriculture
No full textOver the past 10 years, interest in plant biostimulants (PBs) has been on the rise compelled by the growing interest of scientists, extension specialists, private industry, and growers in integrating these products in the array of environmentally friendly tools that secure improved crop performance and yield stability. Based on the new EU regulation PBs are defined through claimed agronomic effects, such as improvement of nutrient use efficiency, tolerance to abiotic stressors and crop quality. This definition entails diverse organic and inorganic substances and/or microorganisms such as humic acids, protein hydrolysates, seaweed extracts, mycorrhizal fungi, and N-fixing bacteria. The current mini-review provides an overview of the direct (stimulatory on C and N metabolism) and indirect (enhancing nutrient uptake and modulating root morphology) mechanisms by which microbial and non-microbial PBs improve nutrient efficiency, plant performance, and physiological status, resilience to environmental stressors and stimulate plant microbiomes. The scientific advances underlying synergistic and additive effects of microbial and non-microbial PBs are compiled and discussed for the first time. The review identifies several perspectives for future research between the scientific community and private industry to design and develop a second generation of PBs products (biostimulant 2.0) with specific biostimulatory action to render agriculture more sustainable and resilient
The importance of chain conformational mobility during 5-exo-cyclizations of C-, N- and O-centred radicals
No full textThe author thanks the EPSRC (grant EP/I003479/1) and EaStCHEM for funding.The reaction coordinates of an archetypical set of 5-exo cyclizations of C-, N- and O-centred radicals were investigated by computational methods. G4 theory, and DFT with the um062x functional, were able to rationalise counterintuitive factors such as the 'normal' order of rate constants being: N-centredPeer reviewe
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Radio Link Quality Estimation in Wireless Sensor Networks: a Survey
No full textRadio link quality estimation in Wireless Sensor Networks (WSNs) has a fundamental impact on the network
performance and also affects the design of higher-layer protocols. Therefore, for about a decade, it has been attracting a
vast array of research works. Reported works on link quality estimation are typically based on different assumptions,
consider different scenarios, and provide radically different (and sometimes contradictory) results. This article provides
a comprehensive survey on related literature, covering the characteristics of low-power links, the fundamental concepts
of link quality estimation in WSNs, a taxonomy of existing link quality estimators, and their performance analysis. To
the best of our knowledge, this is the first survey tackling in detail link quality estimation in WSNs. We believe our
efforts will serve as a reference to orient researchers and system designers in this area
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