163,399 research outputs found
Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players
No full textCastagna, C, Lorenzo, F, Krustrup, P, Fernandes-da-Silva, J, Po ́ voas, SCA, Bernardini, A, and D’Ottavio, S. Reliability charac- teristics and applicability of a repeated sprint ability test in male young soccer players. J Strength Cond Res XX(X): 000–000, 2017—The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test consider- ing 5 line sprints of 30 m interspersed with 30 seconds of active recovery in nonelite, outfield, young, male soccer players. Twenty- six (age, 14.9 6 1.2 years; height, 1.72 6 0.12 cm; body mass, 62.2 6 5.1 kg) players were tested 48 hours and 7 days apart for 5 3 30-m performance over 5 trials (T1–T5). Short-term (T1–T2) and long-term (T1–T3–T4–T5) reliabilities were assessed with intraclass correlation coefficient (ICC) and with typical error for measurement (TEM). Short- and long-term reliability ICCs and TEMs for total sprint time and best sprint performance were nearly perfect and satisfactory, respectively. Usefulness (as smallest worthwhile change and TEM ratio) resulted acceptable (i.e., = 1) and good (i.e., .1) for total sprint time and best sprint perfor- mance, respectively. The present study revealed that the 5 3 30-m sprint test is a reliable field test in short and long terms when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decre- ments variables showed large variability across trials
A donor-acceptor Stenhouse adduct active in neuronal GABAARs and photoswitchable in water
No full text(PO 8) Donor-acceptor Stenhouse adducts are a rapidly emerging class of photochromic compounds whose conformation can be efficiently switched using visible and nearinfrared light. Over the last year, the switching mechanism of DASA has been extensively studied. However, the use of these compounds in water has been hampered by a spontaneous and irreversible conversion to a non photoactive form. The difficulty of using DASAs in water is even more disappointing since they are native red absorbing photoswitching, quality that is widely appreciated in the field of photopharmacology. This field combines a pharmacological approach with the use of light to enable spatio-temporal control of biological processes and drug action. To date, photopharmacology has been extensively used to manipulate biological activity at the cellular level by targeting ion channels, G protein-coupled receptors, enzymes and protein–protein interactions [1,2]. In order to reduce phototoxicity of light used in photopharmacology, low-energy light (i.e. red light) should be used (less scattering in tissue and deeper penetration in the body) and red-absorbing photodrugs need to be designed. To this end, here, we present the molecular design of a novel γ-aminobutyric acid type A receptors (GABAARs) ligand derivative based on the DASA scaffold that displays photochromic properties with red light and is active in neuronal GABAARs [3].
References
1. Eli, S.; Castagna, R.; Mapelli, M.; Parisini, E. Front. Mol. Biosci. 2022, 9, 841777.
2. Castagna, R.; Kolarski, D.; Cuttoli, R. D.-d.; Maleeva, G. J. Mol. Neurosci. 2022, 72, 1433.
3. Castagna, R.; Maleeva, G.; Pirovano, D.; Matera, C.; Gorostiza, P. chemRxiv 2022. doi:10.26434/ chemrxiv-2022-0ps7
Chloride interaction in the SLC6 amino acid cotransporter KAAT1
No full textThe SLC6 family of solute transporters groups eukaryotic, Cl--dependent proteins as the serotonin transporter SERT (1) and the GABA transporter GAT1 (2) and prokaryotic, Cl--independent proteins, as the family model LeuT (3, 4). The main role of the anion in the transport cycle appears to be related to the neutralization of the positive charges of sodium ions transported with the substrate. KAAT1 is a lepidopteran SLC6 amino acid cotransporter, activated by Na+ and K+, but characterized by a weak chloride dependence (5, 6). In recent years, taking advantage of the special features of KAAT1, we have investigated the structural/functional relationships within the SLC6 family. By site-directed mutagenesis and functional expression in Xenopus laevis oocytes, we have identified residues involved in Na+ and K+ interaction and in amino acid translocation (7,8,9). The aim of this study has been the identification of the molecular determinants of chloride interaction of KAAT1 to obtain insights in the transport mechanism of SLC6 members. Comparison of KAAT1 sequence with SERT, GAT1 and LeuT has revealed some differences in residues forming the putative anion binding site but, among theme, only T339 seemed to be relevant for chloride dependence: T339S and T339E mutant transport activity became indeed almost completely Cl--dependent. The mutation of a further residue (T67), conserved only in KAAT1 and in the other weakly Cl--dependent transporter of the family CAATCH1, affected KAAT1 activity: T67Y mutant was fully chloride independent whereas T67S and T67A showed an enhancement in chloride dependence. In order to confirm the role of T67, we built the reciprocal mutant of KAAT1 T67Y in GAT1 transporter: Y60T, interestingly, showed a reduced chloride dependence compared to the wt. These data suggest that T67 and T339 influence KAAT1 interaction with chloride.
1. Forrest L.R. et al., Proc Natl Acad Sci U S A. 2007; 104:12761-6.
2. Zomot E. et al., Nature. 2007 Oct 11; 449: 726-30.
3. Yamashita A. et al., Nature. 2005; 437: 215-23
4. Ben-Yona A. et al., J Biol Chem. 2011; 286: 2826-33
5. Castagna M. et al., Proc Natl Acad Sci U S A.; 95: 5395-400
6. Bettè S. et al., Channels (Austin). 2008; 2: 358-62
7. Mari et al., Cell. Mol. Life Sci. 2004, 61: 243-56.
8. Miszner et al., J. Physiol. 2007, 58: 1899-1913.
9. Castagna et al., Am. J. Physiol. Cell. Physiol. 2007, 293: C1286-C129
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Ecological and Construct Validity of a Repeated Sprint Test in Male Youth Soccer Players
No full textFernandes-Da-Silva, J, Castagna, C, Teixeira, AS, Carminatti, LJ, Francini, L, Póvoas, SCA, and Antonacci Guglielmo, LG. Ecological and construct validity of a repeated sprint test in male youth soccer players. J Strength Cond Res XX(X): 000-000, 2019-This study aimed to examine the relationship between a repeated sprint ability (RSA) test (5 bouts of 30-m sprints interspersed by 30 seconds of recovery) and match-related physical performance in male youth soccer players. Although 60 outfield players were evaluated, only data from players who participated in the full matches (n = 39) were retained (8 central defenders, 7 external defenders, 8 central midfielders, 8 external midfielders, and 8 forwards). To verify the ecological validity of this RSA protocol, the association between the best (RSAbest) and mean (RSAmean) sprint time in the 5 × 30-m and physical match performance during friendly youth soccer games was examined. Physical match demands were assessed using global positioning system technology (10 Hz) considering distance covered in selected arbitrary speed categories. The absolute speed thresholds were the same for all the players. Players were categorized into 2 groups based on the 5 × 30-m performance: RSAmean times below (i.e., faster) and above (i.e., slower) the median value. Players with faster RSAmean times covered significantly more distance sprinting during friendly matches (606 ± 204 m, +47.0%; t = 4.953; effect size = 1.88, 1.24; 2.52, p ≤ 0.001) compared to their slower counterparts (322 ± 145 m). A large negative correlation (r = -0.63, -0.77; -0.44, p ≤ 0.001) was found between RSAbest time (4.59 ± 0.27 seconds) and match sprint distance (457 ± 229 m). Likewise, RSAmean time (4.76 ± 0.25 seconds) was also largely associated (r = -0.60, -0.75; -0.39; p ≤ 0.001) with in-game sprinting performance. The results of this study provided evidence to support the construct and ecological validity of the 5 × 30-m protocol in male youth soccer players. Furthermore, differences in 5 × 30-m performance explained the amount of sprinting activity performed during the match
Online Handbook of Argumentation for AI: Volume 1
No full textEditors: Federico Castagna, Francesca Mosca, Jack Mumford, Stefan Sarkadi and Andreas Xydis.This volume contains revised versions of the papers selected for the first volume of the Online Handbook of Argumentation for AI (OHAAI). Previously, formal theories of argument and argument interaction have been proposed and studied, and this has led to the more recent study of computational models of argument. Argumentation, as a field within artificial intelligence (AI), is highly relevant for researchers interested in symbolic representations of knowledge and defeasible reasoning. The purpose of this handbook is to provide an open access and curated anthology for the argumentation research community. OHAAI is designed to serve as a research hub to keep track of the latest and upcoming PhD-driven research on the theory and application of argumentation in all areas related to AI
Online Handbook of Argumentation for AI: Volume 3
No full textEditors: Federico Castagna, Francesca Mosca, Jack Mumford, Stefan Sarkadi and Andreas Xydis.This volume contains revised versions of the papers selected for the third volume of the Online Handbook of Argumentation for AI (OHAAI). Previously, formal theories of argument and argument interaction have been proposed and studied, and this has led to the more recent study of computational models of argument. Argumentation, as a field within artificial intelligence (AI), is highly relevant for researchers interested in symbolic representations of knowledge and defeasible reasoning. The purpose of this handbook is to provide an open access and curated anthology for the argumentation research community. OHAAI is designed to serve as a research hub to keep track of the latest and upcoming PhD-driven research on the theory and application of argumentation in all areas related to AI
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
A theory of contracts for web services
No full text<p>Contracts are behavioural descriptions of Web services. We devise a theory of contracts that formalises the compatibility of a client to a service, and the safe replacement of a service with another service. The use of contracts statically ensures the successful completion of every possible interaction between compatible clients and services.</p>
<p>The technical device that underlies the theory is the definition of filters, which are explicit coercions that prevent some possible behaviours of services and, in doing so, they make services compatible with different usage scenarios. We show that filters can be seen as proofs of a sound and complete subcontracting deduction system which simultaneously refines and extends Hennessy's classical axiomatisation of the must testing preorder. The relation is decidable and the decision algorithm is obtained via a cut-elimination process that proves the coherence of subcontracting as a logical system.</p>
<p>Despite the richness of the technical development, the resulting approach is based on simple ideas and basic intuitions. Remarkably, its application is mostly independent of the language used to program the services or the clients. We also outline the possible practical impact of such a work and the perspectives of future research it opens.</p>
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