149 research outputs found

    Influence of match status on corner kick in elite soccer

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    El propósito del estudio es analizar como la variable situacional resultado parcial puede afectar al comportamiento táctico-estratégico en los saques de esquina en fútbol. Se han estudiado 902 saques de esquina realizados en 95 partidos correspondientes a la UEFA Euro 2012, y Fase Final de la FIFA World Cup 2010. Para identificar las interacciones se utilizó el método de crecimiento Chi-square automatic interaction detector (CHAID), que nos ha permitido identificar tres modelos: con el resultado de empate en los últimos minutos de juego, el equipo atacante incorpora al remate entre 2 a 5 jugadores y el equipo rival sitúa 1 ó 2 jugadores bajo palos. Ganando en los últimos minutos del encuentro, el equipo sitúa también entre 2 a 5 jugadores en ataque y el rival no defiende bajo palos. Perdiendo en los últimos minutos del encuentro, el equipo atacante incorpora a 6 o más jugadores al ataqueThe aim of this study was to examine the effects of the situational variable match status on corner kicks performance indicators in 95 matches played during the final stages of the 2012 UEFA European Championships and the 2010 FIFA World Cup. Video recordings of the matches were analyzed and coded post-event using notational analysis. Multiple interactions between the performance indicators and match status were analyzed using the Chi-squared automatic interaction detection (CHAID) decision-tree method. The results show that when a corner kick is taken during the last 30 minutes of the match, teams that are losing place 6 or more attackers in the shooting area, while teams that are drawing place 2-5 attackers in this area. In the same situation, teams that are drawing place 1-2 defenders at the goalposts while winning teams place non

    Time-modulated arrays with Haar wavelets

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    Time-modulated arrays (TMAs) can effectively perform beamsteering over the first positive harmonic pattern by applying progressively delayed versions of stair-step approximations of a sine waveform to the antenna excitations. In this letter, we consider synthesizing such stair-step sine approximations by means of Haar wavelets. Haar functions constitute a complete orthonormal set of rectangular waveforms, which have the ability to represent a given function with a high degree of accuracy using few constituent terms. Hence, when they are applied to the TMA synthesis, employing single-pole double-throw switches, such a feature leads to an excellent rejection level of the undesired harmonics as well as a bandwidth greater than that supported by conventional TMAs with on-off switches.Comment: 5 pages, 4 figures, Published in IEEE Antennas and Wireless Propagation Letter

    Time-modulated multibeam phased arrays with periodic Nyquist pulses

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    We present a single sideband time-modulated multibeam phased array governed by periodic Nyquist pulsed signals. A Nyquist pulse is a physically realizable approach to the ideal sinc function. Hence, its low-pass spectrum suits particularly well for time-modulated arrays (TMAs) to perform harmonic beam steering. Contrarily to switched TMAs and standard solutions based on variable phase shifters, the performance and complexity of the proposed time modulation scheme is rather robust when increasing the number of multibeams.Comment: 4 pages, 4 figures, Published in IEEE Antennas and Wireless Propagation Letter

    Nutritional status and physical condition in active vs. sedentary elderly people

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    El objetivo del estudio fue conocer la relación entre el estado nutricional, la adherencia a la dieta mediterránea y el nivel de condición física de personas mayores. Participaron 168 personas mayores de 65 años (grupo control=84 personas activas y grupo experimental=84 personas sedentarias). La adherencia a la dieta mediterránea fue medida con el cuestionario MEDIS-FFQ, el nivel de práctica de actividad física mediante una pregunta creada a tal efecto, y las diferentes pruebas físicas con los instrumentos específicos. Los resultados revelaron que el 63.1% manifestó baja adherencia a la dieta mediterránea y el 34.5% alta, teniendo los sujetos sedentarios mayor adherencia que los activos (p≤0.05; 46.4% vs. 22.6%). Los sujetos activos tienen mejor condición física que los sedentarios (p≤0.001). Por tanto, la mayor parte de las personas mayores deben incrementar su adherencia a la dieta mediterránea y la práctica de actividad física como mecanismo de mejora de su saludThe objective of the study was to know the relationship between nutritional status, adherence to the Mediterranean diet and the level of physical displacement of older people. 168 people older than 65 years participated (control group = 84 active people and experimental group = 84 sedentary people). Adherence to the Mediterranean diet was measured with the MEDIS-FFQ questionnaire, the level of physical activity practice through a question created for that purpose, and the different physical tests with the specific instruments. The results revealed that 63.1% showed low adherence to the Mediterranean diet and 34.5% high, according to the sedentary subject’s greater adherence than the active ones (p≤0.05, 46.4% versus 22.6%). Active subjects have better physical income than sedentary people (p≤0.001). Therefore, most elderly people want to increase their adherence to the Mediterranean diet and the practice of physical activity as a mechanism to reduce their healt

    Hydroxylammonium derivatives for selective active-site lysine modification in the anti-virulence bacterial target DHQ1 enzyme

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    Targeted irreversible inhibitors bearing electrophiles that become activated towards covalent bond formation upon binding to a specific protein/enzyme is an emerging area in drug discovery. Targeting lysine residues is challenging due to the intrinsically low reactivity of the amino group at physiological pH. Herein we report the first example of a hydroxylammonium derivative that causes a specific covalent modification of an active-site and a sterically inaccessible lysine residue of an enzyme. The described ligands, compounds 1–3, were rationally designed to be activated towards covalent bond formation upon binding to the type I dehydroquinase (DHQ1) enzyme for the development of new anti-virulence agents to combat the widespread resistance to antibiotics. Evidence in atomic detail for the covalent modifications caused by the ligands to the catalytic Lys170 by the formation of a stable secondary amine is provided by the resolution at 1.08–1.25 Å of the crystal structures of DHQ1 from Salmonella typhi enzyme adducts. In addition, the first crystal structure of the addition intermediate adduct at 1.4 Å of a Schiff base formation reaction by using an analog of the natural substrate, compound 4, is also reported. Molecular dynamics simulation studies on non-covalent enzyme/ligand complexes and a two-dimensional QM/MM umbrella sampling simulation study suggested that a direct displacement by Lys170 with the release of NH2OH would be feasible. These studies might open up new opportunities for the development of novel lysine-targeted irreversible inhibitors bearing a methylhydroxylammonium moiety as a latent electrophile.Financial support from the Spanish Ministry of Economy and Competiveness (SAF2016-75638-R), the Xunta de Galicia [Centro singular de investigación de Galicia accreditation 2016-2019 (ED431G/09) and ED431B 2018/04] and theEuropean Union (European Regional Development Fund –ERDF) is gratefully acknowledged. MM and EL thank the Spanish Ministry of Education, Culture and Sport and the Xunta de Galicia for their respective FPU and postdoctoral fellowshipsS

    Insights into substrate binding and catalysis in bacterial type I dehydroquinase

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    Structural, biochemical and computational studies to study substrate binding and the role of the conserved residues of the DHQ1 (type I dehydroquinase) enzyme active site are reported in the present paper. The crystal structure of DHQ1 from Salmonella typhi in complex with (2R)-2-methyl-3-dehydroquinic acid, a substrate analogue, was solved at 1.5 Å. The present study reveals a previously unknown key role for conserved Glu, Phe and Met and Gln, Pro and Ala residues, with the latter three being located in the flexible substrate-covering loop. Glu was shown to be responsible for the folding of this loop and for the dramatic reduction of its flexibility, which triggers active site closure. Glu46 was found to be key in bringing the substrate close to the lysine/histidine catalytic pocket to initiate catalysis. The present study could be useful in the rational design of inhibitors of this challenging and recognized target for the development of novel herbicides and antimicrobial agentsThis work was supported by the Spanish Ministry of Science and Innovation (grant number SAF2010-15076) and via FPU fellowships to M.M. and A.P., the Xunta de Galicia (grant number GRC2013/041) and via postdoctoral fellowships to E.L. and J.M.O., and by the European Regional Development Fund (ERDF)S

    Activity of the β-Lactamase inhibitor LN-1-255 against carbapenem-hydrolyzing class D β-lactamases from Acinetobacter baumannii

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    The number of infections caused by Gram-negative pathogens carrying carbapenemases is increasing, and the group of carbapenem-hydrolyzing class D β-lactamases (CHDLs) is especially problematic. Several clinically important CHDLs have been identified in A. baumannii, including OXA-23, OXA-24/40, OXA-58, OXA-143, OXA-235, and the chromosomally encoded OXA-51. The selection and dissemination of carbapenem-resistant A. baumannii strains constitutes a serious global threat. Carbapenems have been successfully utilized as last resort antibiotics for the treatment of multi-drug-resistant A. baumannii infections. However, the spread of OXA carbapenemases is compromising the continued use of these antimicrobials. In response to this clinical issue, it is necessary and urgent to design and develop new specific inhibitors with efficacy against these enzymes. The aim of this work is to characterize the inhibitory activity of LN-1-255 (a 6-alkylidene-2-substituted penicillin sulfone) and compare it to that of two established inhibitors (avibactam and tazobactam) against the most relevant enzymes of each group of class D carbapenemases in A. baumannii. The β-lactamase inhibitor LN-1-255 demonstrated excellent microbiological synergy and inhibition kinetics parameters against all tested CHDLs, and a significantly higher activity than tazobactam and avibactam. A combination of carbapenems and LN-1-255 was effective against A. baumannii class D carbapenemases. Docking assays confirmed the affinity of LN-1-255 for the active site of these enzymes. LN-1-255 represents a potential new β-lactamase inhibitor, which may have a significant role in eradicating infections caused by A. baumannii isolates carrying CHDLsThis work was supported by the Spanish National Plans for Scientific Research, Development and Technological Innovation 2008-2011 and 2013-2016 and funded by the ISCIII- General Subdirection of Assessment and Promotion of the Research-European Regional Development Fund (ERDF) “A way of making Europe”: PI12/00552 to G.B. and PI14/00059 to M.P. and A.B. Also, this study was supported in part by funds from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health (USA) under award numbers R01AI063517 and R01AI100560, by funds and/or facilities provided by the Cleveland Department of Veterans Affairs, the Veterans Affairs Merit Review Program Award 1I01BX001974 and the Geriatric Research Education and Clinical Center VISN 10 to R.A.B., and by the Spanish Ministry of Economy and Competiveness (SAF2013-42899-R), Xunta de Galicia (GRC2013-041) and the European Regional Development Fund (ERDF) to C.GB. J.V. was financially supported by the Sara Borrell Programme ISCIII-FEDER (CD13/00373). J.V.H. and A.B. were financially supported by the Miguel Servet Programme ISCIII-FEDER (CP13/00226)S

    Irreversible covalent modification of type I dehydroquinase with a stable Schiff base

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    The irreversible inhibition of type I dehydroquinase (DHQ1), the third enzyme of the shikimic acid pathway, is investigated by structural, biochemical and computational studies. Two epoxides, which are mimetics of the natural substrate, were designed as irreversible inhibitors of the DHQ1 enzyme and to study the binding requirements of the linkage to the enzyme. The epoxide with the S configuration caused the covalent modification of the protein whereas no reaction was obtained with its epimer. The first crystal structure of DHQ1 from Salmonella typhi covalently modified by the S epoxide, which is reported at 1.4 Å, revealed that the modified ligand is surprisingly covalently attached to the essential Lys170 by the formation of a stable Schiff base. The experimental and molecular dynamics simulation studies reported here highlight the huge importance of the conformation of the C3 carbon of the ligand for covalent linkage to this type of aldolase I enzyme, revealed the key role played by the essential His143 as a Lewis acid in this process and show the need for a neatly closed active site for catalysisFinancial support from the Spanish Ministry of Science and Innovation (SAF2013-42899-R), Xunta de Galicia (GRC2013-041) and the European Regional Development Fund (ERDF) is gratefully acknowledged. LT, AP and MM thank the Spanish Ministry of Education for their respective FPU fellowships. EL and JMO thank and the Xunta de Galicia for their respective postdoctoral fellowshipsS
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