593 research outputs found

    Physiognomic and physiologic changes in mountain grasslands in response to environmental and anthropogenic factors

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    Mountain grasslands provide valuable ecosystem services for sustainable development and human wellbeing. These habitats have suffered important changes related with their physiognomic (biomass) and physiologic (greenness) properties. Some of these changes received significant attention i.e. woody encroachment, while others, like the changes in biomass and greenness of those grasslands that have not experienced woody encroachment are almost unknown. We calculated physiognomic and physiologic properties for dense grasslands not affected by woody encroachment through the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Infrared Index (NDII) from Landsat-5 Thematic Mapper. Imagery taken in the late-1980s and late-2000s in the Spanish Pyrenees were analyzed with multi-temporal vectors to detect increases or decreases of biomass and greenness. To understand the source of these changes, we modeled them with anthropogenic (land use, i.e. grazing, ski resorts, and related infrastructures) and environmental factors (topographic, lithologic and climatic). Anthropogenic factors were most strongly correlated with decrease in the biomass and greenness, showing degradation patterns of the grasslands at localized patches. Nonetheless, environmental factors were most strongly correlated with positive changes in both indices, detecting a continuous pattern in the increase in biomass and greenness. In areas that had high livestock stocking rates, grasslands biomass and greenness decrease, while in areas that had low stocking rates, biomass and greenness increases. Grasslands at low elevation showing decrease in biomass and greenness were either on gentle slopes and largely affected by human activities, or on steep slopes locally affected by ski resorts. In areas that have been disturbed by anthropogenic factors, the increase of rain in early summer trigger erosion processes, enhancing the negative effect of anthropic pressure on grassland greenness and biomass. In contrast, grasslands at high elevations, on steep slopes, and those that had north or west aspects and that had an acidic lithology, with less continentality, and that received more rain, had the most increase in biomass and greenness. Those results suggest that changes in mountain grasslands, apart from woody encroachment, are deeply altering their physiology and physiognomy, pointing out direct relationships with current management practices and climate trends.This research was funded by the following research projects; Ref.:125/2010 MMAMRM (Spanish Ministry of Agriculture and Environment), CGL2011-27259 (Spanish Ministry of Economy and Competitiveness and Innovation) co-financed by the FEDER, and FW7 ENV.2009.2.1.3.2-LEDDRA (European Community). CGB was supported by the AXA Research Fund (PDOC_2011_W2) and Killam Postdoctoral Fellowship (University of Alberta (2012-2013)). F. Fillat and R. García provided interesting comments and supporting climatic information.Peer reviewe

    The Lhcb protein and xanthophyll composition of the light harvesting antenna controls the ΔpH-dependency of non-photochemical quenching in Arabidopsis thaliana

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    AbstractNonphotochemical quenching (NPQ) is the photoprotective dissipation of energy in photosynthetic membranes. The hypothesis that the ΔpH-dependent component of NPQ (qE) component of non-photochemical quenching is controlled allosterically by the xanthophyll cycle has been tested using Arabidopsis mutants with different xanthophyll content and composition of Lhcb proteins. The titration curves of qE against ΔpH were different in chloroplasts containing zeaxanthin or violaxanthin, proving their roles as allosteric activator and inhibitor, respectively. The curves differed in mutants deficient in lutein and specific Lhcb proteins. The results show that qE is determined by xanthophyll occupancy and the structural interactions within the antenna that govern allostericity

    Relativistic and Newtonian kappa spacetimes

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    The deformations of the Galilei algebra and their associated noncommutative Newtonian spacetimes are investigated. This is done by analyzing the possible nonrelativistic limits of an eleven generator (pseudo)extended \kap-Poincar\'e algebra P~κ\tilde{\cal P}_\kappa and their implications for the existence of a first order differential calculus. The additional one-form needed to achieve a consistent calculus on \kap-Minkowski space is shown to be related to the additional central generator entering in the P~κ\tilde{\cal P}_\kappa Hopf algebra. In the process, deformations of the extended Galilei and Galilei algebras are introduced which have, respectively, a cocycle and a bicrossproduct structure.Comment: Slightly shortened version with small changes to adapt the paper to JMP styl

    On the bicrossproduct structures for the Uλ(isoω2...ωN(N)){\cal U}_\lambda(iso_{\omega_2... \omega_N}(N)) family of algebras

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    It is shown that the family of deformed algebras Uλ(isoω2...ωN(N)){\cal U}_\lambda(iso_{\omega_2... \omega_N}(N)) has a different bicrossproduct structure for each ωa=0\omega_a=0 in analogy to the undeformed case.Comment: Latex2e file. 14 page

    METADOCK 2: a high-throughput parallel metaheuristic scheme for molecular docking

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    [EN] Motivation Molecular docking methods are extensively used to predict the interaction between protein-ligand systems in terms of structure and binding affinity, through the optimization of a physics-based scoring function. However, the computational requirements of these simulations grow exponentially with: (i) the global optimization procedure, (ii) the number and degrees of freedom of molecular conformations generated and (iii) the mathematical complexity of the scoring function. Results In this work, we introduce a novel molecular docking method named METADOCK 2, which incorporates several novel features, such as (i) a ligand-dependent blind docking approach that exhaustively scans the whole protein surface to detect novel allosteric sites, (ii) an optimization method to enable the use of a wide branch of metaheuristics and (iii) a heterogeneous implementation based on multicore CPUs and multiple graphics processing units. Two representative scoring functions implemented in METADOCK 2 are extensively evaluated in terms of computational performance and accuracy using several benchmarks (such as the well-known DUD) against AutoDock 4.2 and AutoDock Vina. Results place METADOCK 2 as an efficient and accurate docking methodology able to deal with complex systems where computational demands are staggering and which outperforms both AutoDock Vina and AutoDock 4.This work was partially supported by the Fundación Séneca del Centro de Coordinación de la Investigación de la Región de Murcia [Projects 20813/PI/ 18, 20988/PI/18, 20524/PDC/18] and by the Spanish Ministry of Science, Innovation and Universities [TIN2016-78799-P (AEI/FEDER, UE), CTQ2017-87974-R]. The authors thankfully acknowledge the computer resources at CTE-POWER and the technical support provided by Barcelona Supercomputing Center - Centro Nacional de Supercomputación [RES-BCV2018-3-0008].Imbernón, B.; Serrano, A.; Bueno-Crespo, A.; Abellán, JL.; Pérez-Sánchez, H.; Cecilia-Canales, JM. (2020). METADOCK 2: a high-throughput parallel metaheuristic scheme for molecular docking. Bioinformatics. 1-6. https://doi.org/10.1093/bioinformatics/btz958S16Bianchi, L., Dorigo, M., Gambardella, L. M., & Gutjahr, W. J. (2008). A survey on metaheuristics for stochastic combinatorial optimization. Natural Computing, 8(2), 239-287. doi:10.1007/s11047-008-9098-4Cecilia, J. M., Llanes, A., Abellán, J. L., Gómez-Luna, J., Chang, L.-W., & Hwu, W.-M. W. (2018). High-throughput Ant Colony Optimization on graphics processing units. Journal of Parallel and Distributed Computing, 113, 261-274. doi:10.1016/j.jpdc.2017.12.002Desiraju, G., & Steiner, T. (2001). 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LEADS-PEP: A Benchmark Data Set for Assessment of Peptide Docking Performance. Journal of Chemical Information and Modeling, 56(1), 188-200. doi:10.1021/acs.jcim.5b00234Llanes, A., Muñoz, A., Bueno-Crespo, A., García-Valverde, T., Sánchez, A., Arcas-Túnez, F., … M. Cecilia, J. (2016). Soft Computing Techniques for the Protein Folding Problem on High Performance Computing Architectures. Current Drug Targets, 17(14), 1626-1648. doi:10.2174/1389450117666160201114028McIntosh-Smith, S., Price, J., Sessions, R. B., & Ibarra, A. A. (2014). High performance in silico virtual drug screening on many-core processors. The International Journal of High Performance Computing Applications, 29(2), 119-134. doi:10.1177/1094342014528252Mehler, E. L., & Solmajer, T. (1991). Electrostatic effects in proteins: comparison of dielectric and charge models. «Protein Engineering, Design and Selection», 4(8), 903-910. doi:10.1093/protein/4.8.903Morris, G. M., Goodsell, D. S., Halliday, R. S., Huey, R., Hart, W. 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Science, 347(6225), 995-998. doi:10.1126/science.1258758Sánchez-Linares, I., Pérez-Sánchez, H., Cecilia, J. M., & García, J. M. (2012). High-Throughput parallel blind Virtual Screening using BINDSURF. BMC Bioinformatics, 13(S14). doi:10.1186/1471-2105-13-s14-s13Sliwoski, G., Kothiwale, S., Meiler, J., & Lowe, E. W. (2013). Computational Methods in Drug Discovery. Pharmacological Reviews, 66(1), 334-395. doi:10.1124/pr.112.007336Sörensen, K. (2013). Metaheuristics-the metaphor exposed. International Transactions in Operational Research, 22(1), 3-18. doi:10.1111/itor.12001Yuan, S., Chan, J. F.-W., den-Haan, H., Chik, K. K.-H., Zhang, A. J., Chan, C. C.-S., … Yuen, K.-Y. (2017). Structure-based discovery of clinically approved drugs as Zika virus NS2B-NS3 protease inhibitors that potently inhibit Zika virus infection in vitro and in vivo. Antiviral Research, 145, 33-43. doi:10.1016/j.antiviral.2017.07.00

    Exercise variables and pain threshold reporting for strength training protocols in people with haemophilia: a systematic review of clinical trials

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    Introduction: Although strength exercise is often prescribed for people with haemophilia (PWH), it remains unknown how exercise variables and pain thresholds are used to prescribe strength training in PWH. Aim: To analyse how strength exercise variables and pain thresholds have been used to prescribe strength training in PWH. Methods: A systematic search was conducted in PubMed, Embase, Web of Science, CENTRAL and CINAHL databases from inception to 7 September 2022. Studies whose intervention included strengthening training in adults with haemophilia were included. Two independent reviewers were involved in study selection, data extraction and risk of bias assessment. Results: Eighteen studies were included. The least reported variables among the studies were: prophylactic factor coverage (11.1%), pain threshold/tolerability (5.6%), intensity (50%), total or partial range of motion (27.8%), time under tension (27.8%), attentional focus modality (0%), therapist experience in haemophilia (33.3%) and adherence assessment (50%). In contrast, weekly frequency (94.4%), duration (weeks) (100%), number of sets/repetitions (88.9%), repetitions to failure/not to failure (77.8%), types of contraction (77.8%), rest duration (55.6%), progression (55.6%), supervision (77.8%), exercise equipment (72.2%) and adverse event record (77.8%) had a higher percentage of reported (>50% of studies). Conclusion: Future research on strength training for PWH should improve information on pain threshold and other important variables such as prophylactic factor coverage, intensity, range of motion, time under tension, attentional focus modality, therapist experience in haemophilia and adherence assessment. This could improve clinical practice and comparison of different protocols

    Effects of a massage protocol in tensiomyographic and myotonometric proprieties

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    Background: Pre-competition massage is usually used to improve athletic performance and reduce risk of injury. Despite its usual use, the effects of pre-competition massage on neuromuscular function have barely been studied. The aim of this study is to evaluate the effects of the pre-competition massage over the gastrocnemius neuromuscular function. Method: The study is a quasi-experimental clinical trial thirty healthy athletes were enrolled in the study. Subjects received an intervention in one leg (experimental), consisting of a massage, and no intervention in the opposite leg (control). From all values of neuromuscular function, the following were analyzed: contraction time (Tc) and maximal displacement (Dm) by tensiomyography, and stiffness and tone by myotonometry. Results: Main effects of pre-competition massage on neuromuscular function include a significant (p < 0.05) increase in Tc and Dm variables, as well as a reduction in stiffness and tone. Conclusion: Data shows an increase in Tc and maximal radial displacement (Dm) variables, as well as a reduction in stiffness and tone. More quality studies are needed to draw clear conclusions about the effects of pre-competition massage. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Effect of diacutaneous fibrolysis on the muscular properties of gastrocnemius muscle

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    Diacutaneous fibrolysis is a noninvasive technique that has been shown to be effective in the treatment of musculoskeletal disorders such as shoulder pain, lateral epicondylalgia, patellofemoral pain syndrome and carpal tunnel syndrome. However, while diacutaneous fibrolysis is applied to soft tissue, its effects on muscular properties are unknown. The purpose of the present study was to evaluate the effects of diacutaneous fibrolysis on muscle properties as measured by tensiomyography and myotonometry in asymptomatic subjects. An analytical descriptive study was performed. A single session of diacutaneous fibrolysis on the gastrocnemius muscle was applied to one limb (treated limb group) and the other limb was the control (control limb group). Subjects were assessed with tensiomyography and myotonometry before treatment (T0), after treatment (T1) and 30 minutes later (T2). The primary outcomes were tensiomyography and myotonometry variables. The treated limb group showed a statistically significant increase (p<0.05) in tensiomyography parameters. A decrease in rigidity and increase in relaxation was also observed on myotonometry at T1, with some of the effects being maintained at T2. Rigidity and relaxation at T1 were statistically significant between groups (p<0.05). A single session of diacutaneous fibrolysis to the gastrocnemius muscle of asymptomatic subjects produced immediate changes in muscle properties. These changes were maintained 30 minutes after the application of the technique

    Generalized Jacobi structures

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    Jacobi brackets (a generalization of standard Poisson brackets in which Leibniz's rule is replaced by a weaker condition) are extended to brackets involving an arbitrary (even) number of functions. This new structure includes, as a particular case, the recently introduced generalized Poisson structures. The linear case on simple group manifolds is also studied and non-trivial examples (different from those coming from generalized Poisson structures) of this new construction are found by using the cohomology ring of the given group.Comment: Latex2e file. 11 pages. To appear in J. Phys.

    Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location

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    The European hake (Merluccius merluccius) is a highly valuable and intensely fished species in which a long-term alive stock has been established in captivity for aquaculture purposes. Due to their huge economic importance, genetic studies on hakes were mostly focused on phylogenetic and phylogeographic aspects; however chromosome numbers are still not described for any of the fifteen species in the genus Merluccius. In this work we report a chromosome number of 2n = 42 and a karyotype composed of three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. Telomeric sequences appear exclusively at both ends of every single chromosome. Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4. While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19. The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals. Therefore, the use of these probes allows the unequivocal identification of at least 7 of the chromosome pairs that compose the karyotype of Merluccius merluccius thus opening the way to integrate molecular genetics and cytological data on the study of the genome of this important species.Versión del editor4,411
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