454 research outputs found

    The Effectiveness of Lower-Limb Wearable Technology for Improving Activity and Participation in Adult Stroke Survivors: A Systematic Review

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    Background: With advances in technology, the adoption of wearable devices has become a viable adjunct in poststroke rehabilitation. Regaining ambulation is a top priority for an increasing number of stroke survivors. However, despite an increase in research exploring these devices for lower limb rehabilitation, little is known of the effectiveness. Objective: This review aims to assess the effectiveness of lower limb wearable technology for improving activity and participation in adult stroke survivors. Methods: Randomized controlled trials (RCTs) of lower limb wearable technology for poststroke rehabilitation were included. Primary outcome measures were validated measures of activity and participation as defined by the International Classification of Functioning, Disability and Health. Databases searched were MEDLINE, Web of Science (Core collection), CINAHL, and the Cochrane Library. The Cochrane Risk of Bias Tool was used to assess the methodological quality of the RCTs. Results: In the review, we included 11 RCTs with collectively 550 participants at baseline and 474 participants at final follow-up including control groups and participants post stroke. Participants' stroke type and severity varied. Only one study found significant between-group differences for systems functioning and activity. Across the included RCTs, the lowest number of participants was 12 and the highest was 151 with a mean of 49 participants. The lowest number of participants to drop out of an RCT was zero in two of the studies and 19 in one study. Significant between-group differences were found across three of the 11 included trials. Out of the activity and participation measures alone, P values ranged from P=.87 to P≤.001. Conclusions: This review has highlighted a number of reasons for insignificant findings in this area including low sample sizes, appropriateness of the RCT methodology for complex interventions, a lack of appropriate analysis of outcome data, and participant stroke severity

    Tonic excitation or inhibition is set by GABAA conductance in hippocampal interneurons

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    Inhibition is a physiological process that decreases the probability of a neuron generating an action potential. The two main mechanisms that have been proposed for inhibition are hyperpolarization and shunting. Shunting results from increased membrane conductance, and it reduces the neuron-firing probability. Here we show that ambient GABA, the main inhibitory neurotransmitter in the brain, can excite adult hippocampal interneurons. In these cells, the GABAA current reversal potential is depolarizing, making baseline tonic GABAA conductance excitatory. Increasing the tonic conductance enhances shunting-mediated inhibition, which eventually overpowers the excitation. Such a biphasic change in interneuron firing leads to corresponding changes in the GABAA-mediated synaptic signalling. The described phenomenon suggests that the excitatory or inhibitory actions of the current are set not only by the reversal potential, but also by the conductance

    Plasmodium knowlesi thioredoxin peroxidase 1 binds to nucleic acids and has RNA chaperone activity

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    Malaria parasites are under oxidative attack throughout their life cycle in human body and mosquito vector. Therefore, Plasmodium antioxidant defenses are crucial for its survival and being considered as interesting target for antimalarial drug design. Plasmodium knowlesi has emerged recently from its simian host to human in Southeast Asia and has been recognized as the fifth Plasmodium species that can cause human malaria. In this study, we cloned and characterized thioredoxin peroxidase 1 from P. knowlesi (PkTPx-1). PkTPx-1 gene was cloned, and recombinant protein was produced by heterologous overexpression in Escherichia coli. The recombinant protein was used for evaluation of enzymatic activity and polyclonal antibody production. Using the recombinant PkTPx-1 protein, its antioxidant activity was confirmed in a mixed-function oxidation assay where PkTPx-1 prevented nicking of DNA by hydroxyl radicals. PkTPx-1 was able to bind to double-strand DNA and RNA and had RNA chaperone activity in a nucleic acid melting assay indicating new function of PkTPx-1 other than antioxidant activity. Using specific polyclonal antibodies, it was indicated that PkTPx-1 is expressed in the cytoplasm of the parasite. Altogether, these results suggest that PkTPx-1 not only protects the parasite from the adverse effects of reactive oxygen species but also has RNA chaperone activity

    Competitive Tendering In The Netherlands: Central Planning Or Functional Specifications?

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    Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    Photosynthetic responses of sun- and shade-grown barley leaves to high light: is the lower PSII connectivity in shade leaves associated with protection against excess of light?

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    Frequently asked questions about chlorophyll fluorescence, the sequel

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    [EN] Using chlorophyll (Chl) a fluorescence many aspects of the photosynthetic apparatus can be studied, both in vitro and, noninvasively, in vivo. Complementary techniques can help to interpret changes in the Chl a fluorescence kinetics. Kalaji et al. (Photosynth Res 122: 121-158, 2014a) addressed several questions about instruments, methods and applications based on Chl a fluorescence. Here, additionalChl a fluorescence-related topics are discussed again in a question and answer format. Examples are the effect of connectivity on photochemical quenching, the correction of F-V/F-M values for PSI fluorescence, the energy partitioning concept, the interpretation of the complementary area, probing the donor side of PSII, the assignment of bands of 77 K fluorescence emission spectra to fluorescence emitters, the relationship between prompt and delayed fluorescence, potential problems when sampling tree canopies, the use of fluorescence parameters in QTL studies, the use of Chl a fluorescence in biosensor applications and the application of neural network approaches for the analysis of fluorescence measurements. The answers draw on knowledge fromdifferent Chl a fluorescence analysis domains, yielding in several cases new insights.Kalaji, H.; Schansker, G.; Brestic, M.; Bussotti, F.; Calatayud, A.; Ferroni, L.; Goltsev, V.... (2017). Frequently asked questions about chlorophyll fluorescence, the sequel. Photosynthesis Research. 132(1):13-66. https://doi.org/10.1007/s11120-016-0318-yS13661321Adams WW III, Demmig-Adams B (1992) Operation of the xanthophyll cycle in higher plants in response to diurnal changes in incident sunlight. Plant 186:390–398Adams WW III, Demmig-Adams B (2004) Chlorophyll fluorescence as a tool to monitor plant response to the environment. In: Papageorgiou GC, Govindjee (eds) Advances in photosynthesis and respiration series chlorophyll fluorescence: a signature of photosynthesis, vol 19. Springer, Dordrecht, pp 583–604Adams WW III, Demmig-Adams B, Winter K, Schreiber U (1990a) The ratio of variable to maximum chlorophyll fluorescence from photosystem II, measured in leaves at ambient temperature and at 77 K, as an indicator of the photon yield of photosynthesis. Planta 180:166–174Adams WW III, Winter K, Schreiber U, Schramel P (1990b) Photosynthesis and chlorophyll fluorescence characteristics in relationship to changes in pigment and element composition of leaves of Platanus occidentalis L. during autumnal senescence. Plant Physiol 93:1184–1190Alfonso M, Montoya G, Cases R, Rodriguez R, Picorel R (1994) Core antenna complexes, CP43 and CP47, of higher plant photosystem II. Spectral properties, pigment stoichiometry, and amino acid composition. Biochemistry 33:10494–10500Allakhverdiev SI (2011) Recent progress in the studies of structure and function of photosystem II. J Photochem Photobiol B Biol 104:1–8Allakhverdiev SI, Klimov VV, Carpentier R (1994) Variable thermal emission and chlorophyll fluorescence in photosystem II particles. Proc Natl Acad Sci USA 491:281–285Allakhverdiev SI, Los DA, Mohanty P, Nishiyama Y, Murata N (2007) Glycinebetaine alleviates the inhibitory effect of moderate heat stress on the repair of photosystem II during photoinhibition. Biochim Biophys Acta 1767:1363–1371Allen JF (1992) Protein phosphorylation in regulation of photosynthesis. Biochim Biophys Acta 1098:275–335Allen JF, Bennett J, Steinback KE, Arntzen CJ (1981) Chloroplast protein phosphorylation couples platoquinone redox state to distribution of excitation energy between photosystems. Nature 291:21–25Amesz J, van Gorkom HJ (1978) Delayed fluorescence in photosynthesis. Annu Rev Plant Physiol 29:47–66Ananyev GM, Dismukes GC (1996) Assembly of the tetra-Mn site of photosynthetic water oxidation by photoactivation: Mn stoichiometry and detection of a new intermediate. Biochemistry 35:4102–4109Anderson JM, Chow WS, Goodchild DJ (1988) Thylakoid membrane organization in sun/shade acclimation. Aust J Plant Physiol 15:11–26Andrizhiyevskaya EG, Chojnicka A, Bautista JA, Diner BA, van Grondelle R, Dekker JP (2005) Origin of the F685 and F695 fluorescence in photosystem II. Photosynth Res 84:173–180Anithakumari AM, Nataraja KN, Visser RGF, van der Linden G (2012) Genetic dissection of drought tolerance and recovery potential by quantitative trait locus mapping of a diploid potato population. Mol Breed 30:1413–1429Antal TK, Krendeleva TE, Rubin AB (2007) Study of photosystem 2 heterogeneity in the sulfur-deficient green alga Chlamydomonas reinhardtii. Photosynth Res 94:13–22Antal TK, Matorin DN, Ilyash LV, Volgusheva AA, Osipov A, Konyuhow IV, Krendeleva TE, Rubin AB (2009) Probing of photosynthetic reactions in four phytoplanktonic algae with a PEA fluorometer. Photosynth Res 102:67–76Araus JL, Amaro T, Voltas J, Nakkoul H, Nachit MM (1998) Chlorophyll fluorescence as a selection criterion for grain yield in durum wheat under Mediterranean conditions. Field Crops Res 55:209–223Argyroudi-Akoyunoglou J (1984) The 77 K fluorescence spectrum of the Photosystem I pigment-protein complex CPIa. FEBS Lett 171:47–53Arnold WA (1991) Experiments. Photosynth Res 27:73–82Arnold WA, Thompson J (1956) Delayed light production by blue-green algae, red algae and purple bacteria. J Gen Physiol 39:311–318Aro EM, Hundal T, Carlberg I, Andersson B (1990) In vitro studies on light-induced inhibition of PSII and D1-protein degradation at low temperatures. Biochim Biophys Acta 1019:269–275Aro EM, Virgin I, Andersson B (1993) Photoinhibition of photosystem II. Inactivation protein damage and turnover. Biochim Biophys Acta 1143:113–134Arsalane W, Parésys G, Duval JC, Wilhelm C, Conrad R, Büchel C (1993) A new fluorometric device to measure the in vivo chlorophyll a fluorescence yield in microalgae and its use as a herbicide monitor. Eur J Phycol 28:247–252Asada K (1999) The water-water cycle in chloroplasts: scavenging of active oxygens and dissipation of excess photons. Annu Rev Plant Physiol Plant Mol Biol 50:601–639Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plants. Plant Sci 166:3–16Bailey S, Walters RG, Jansson S, Horton P (2001) Acclimation of Arabidopsis thaliana to the light environment: the existence of separate low light and high light responses. Planta 213:794–801Baker NR (2008) Chlorophyll fluorescence: a probe of photosynthesis in vivo. Annu Rev Plant Biol 59:659–668Baker NR, Rosenqvist E (2004) Applications of chlorophyll fluorescence can improve crop production strategies: an examination of future possibilities. J Exp Bot 55:1607–1621Ballottari M, Dall’Osto L, Morosinotto T, Bassi R (2007) Contrasting behavior of higher plant photosystem I and II antenna systems during acclimation. J Biol Chem 282:8947–8958Barbagallo RP, Oxborough K, Pallett KE, Baker NR (2003) Rapid, noninvasive screening for perturbations of metabolism and plant growth using chlorophyll fluorescence imaging. Plant Physiol 132:485–493Barber J, Malkin S, Telfer A (1989) The origin of chlorophyll fluorescence in vivo and its quenching by the photosystem II reaction centre. Philos Trans R Soc Lond B 323:227–239Barra M, Haumann M, Loja P, Krivanek R, Grundmeier A, Dau H (2006) Intermediates in assembly by photoactivation after thermally accelerated disassembly of the manganese complex of photosynthetic water oxidation. Biochemistry 45:14523–14532Baumann HA, Morrison L, Stengel DB (2009) Metal accumulation and toxicity measured by PAM-chlorophyll fluorescence in seven species of marine macroalgae. Ecotoxicol Environ Safe 72:1063–1075Bauwe H, Hagemann M, Fernie A (2010) Photorespiration: players, partners and origin. Trends Plant Sci 15:330–336Beck WF, Brudvig GW (1987) Reactions of hydroxylamine with the electron-donor side of photosystem II. Biochemistry 26:8285–8295Belgio E, Kapitonova E, Chmeliov J, Duffy CDP, Ungerer P, Valkunas L, Ruban AV (2014) Economic photoprotection in photosystem II that retains a complete light-harvesting system with slow energy traps. Nat Commun 5:4433. doi: 10.1038/ncomms5433Bell DH, Hipkins MF (1985) Analysis of fluorescence induction curves from pea chloroplasts: photosystem II reaction centre heterogeneity. Biochim Biophys Acta 807:255–262Bellafiore S, Barneche F, Peltier G, Rochaix J-D (2005) State transitions and light adaptation require chloroplast thylakoid protein kinase STN7. Nature 433:892–895Belyaeva NE, Schmitt F-J, Paschenko VZ, Riznichenko GY, Rubin AB (2015) Modeling of the redox state dynamics in photosystem II of Chlorella pyrenoidosa Chick cells and leaves of spinach and Arabidopsis thaliana from single flash-induced fluorescence quantum yield changes on the 100 ns–10 s time scale. Photosynth Res 125:123–140Bennett J (1977) Phosphorylation of chloroplast membrane polypeptides. Nature 269:344–346Bennett J (1983) Regulation of photosynthesis by reversible phosphorylation of the light-harvesting chlorophyll a/b protein. Biochem J 212:1–13Bennett J, Shaw EK, Michel H (1988) Cytochrome b6f complex is required for phosphorylation of light-harvesting chlorophyll a/b complex II in chloroplast photosynthetic membranes. Eur J Biochem 171:95–100Bennoun P (2002) The present model for chlororespiration. Photosynth Res 73:273–277Bennoun P, Li Y-S (1973) New results on the mode of action of 3,-(3,4-dichlorophenyl)-1,1-dimethylurea in spinach chloroplasts. Biochim Biophys Acta 292:162–168Berden-Zrimec M, Drinovec L, Zrimec A (2011) Delayed fluorescence. In: Suggett DJ, Borowitzka M, Prášil O (eds) Chlorophyll a fluorescence in aquatic sciences: methods and applications, developments in applied phycology, vol 4. Springer, The Netherlands, pp 293–309Berger S, Sinha AK, Roitsch T (2007) Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions. J Exp Bot 58:4019–4026Bernacchi CJ, Leakey ADB, Heady LE, Morgan PB, Dohleman FG, McGrath JM, Gillespie GM, Wittig VE, Rogers A, Long SP, Ort DR (2006) Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions. Plant Cell Environ 29:2077–2090Betterle N, Ballotari M, Zorzan S, de Bianchi S, Cazzaniga S, Dall’Osto L, Morosinotto T, Bassi R (2009) Light-induced dissociation of an antenna hetero-oligomer is needed for non-photochemical quenching induction. J Biol Chem 284:15255–15266Bielczynski LW, Schansker G, Croce R (2016) Effect of light acclimation on the organization of photosystem II super and sub-complexes in Arabidopsis thaliana. Front Plant Sci. doi: 10.3389/fpls.2016.00105Björkman O, Demmig-Adams B (1995) Regulation of photosynthetic light energy capture, conversion, and dissipation in leaves of higher plants. In: Schulze ED, Caldwell MM (eds) Ecophysiology of photosynthesis. Springer, Berlin, pp 17–47Blubaugh DJ, Cheniae GM (1990) Kinetics of photoinhibition in hydroxylamine-extracted photosystem II membranes: relevance to photoactivation and site of electron donation. Biochemistry 29:5109–5118Bock A, Krieger-Liszkay A, Ortiz de Zarate IB, Schönknecht G (2001) Cl—channel inhibitors of the arylaminobenzoate type act as photosystem II herbicides: a functional and structural study. Biochemistry 40:3273–3281Bode S, Quentmeier CC, Liao P-N, Hafi N, Barros T, Wilk L, Bittner F, Walla PJ (2009) On the regulation of photosynthesis by excitonic interactions between carotenoids and chlorophylls. Proc Natl Acad Sci USA 106:12311–12316Boekema EJ, Van Roon H, Van Breemen JFL, Dekker JP (1999) Supramolecular organization of photosystem II and its light-harvesting antenna in partially solubilized photosystem II membranes. Eur J Biochem 266:444–452Bolhar-Nordenkampf HR, Long SP, Baker NR, Öquist G, Schreiber U, Lechner EG (1989) Chlorophyll fluorescence as a probe of the photosynthetic competence of leaves in the field: a review of current Instrumentation. Funct Ecol 3:497–514Bonaventura C, Myers J (1969) Fluorescence and oxygen evolution from Chlorella pyrenoidosa. Biochim Biophys Acta 189:366–383Bonfig KB, Schreiber U, Gabler A, Roitsch T, Berger S (2006) Infection with virulent and avirulent P. syringae strains differentially affects photosynthesis and sink metabolism in Arabidopsis leaves. Planta 225:1–12Bouges-Bocquet B (1980) Kinetic models for the electron donors of photosystem II of photosynthesis. Biochim Biophys Acta 594:85–103Bradbury M, Baker NR (1981) Analysis of the slow phases of the in vivo chlorophyll fluorescence induction curve; changes in the redox state of photosystem II electron acceptors and fluorescence emission from photosystem I and II. Biochim Biophys Acta 635:542–551Brestič M, Živčák M (2013) PSII fluorescence techniques for measurement of drought and high temperature stress signal in crop plants: protocols and applications. In: Das AB, Rout GR (eds) Molecular stress physiology of plants. Springer, New Dehli, pp 87–131Brestič M, Cornic G, Fryer MJ, Baker NR (1995) Does photorespiration protect the photosynthetic apparatus in French bean leaves from photoinhibition during drought stress? Planta 196:450–457Brestič M, Živčák M, Kalaji HM, Allakhverdiev SI, Carpentier R (2012) Photosystem II thermo-stability in situ: environmentally induced acclimation and genotype-specific reactions in Triticum aestivum L. Plant Physiol Biochem 57:93–105Brody SS, Rabinowitch E (1957) Excitation lifetime of photosynthetic pigments in vitro and in vivo. Science 125:555–563Brudvig GW, Casey JL, Sauer K (1983) The effect of temperature on the formation and decay of the multiline EPR signal species associated with photosynthetic oxygen evolution. Biochim Biophys Acta 723:366–371Bukhov NG, Boucher N, Carpentier R (1997) The correlation between the induction kinetics of the photoacoustic signal and chlorophyll fluorescence in barley leaves is governed by changes in the redox state of the photosystem II acceptor side; a study under atmospheric and high CO2 concentrations. Can J Bot 75:1399–1406Bukhov N, Egorova E, Krendeleva T, Rubin A, Wiese C, Heber U (2001) Relaxation of variable chlorophyll fluorescence after illumination of dark-adapted barley leaves as influenced by the redox states of electron carriers. Photosynth Res 70:155–166Buschmann C, Koscányi L (1989) Light-induced heat production correlated with chlorophyll fluorescence and its quenching. Photosynth Res 21:129–136Bussotti F (2004) Assessment of stress conditions in Quercus ilex L. leaves by O-J-I-P chlorophyll a fluorescence analysis. Plant Biosystems 13:101–109Bussotti F, Agati G, Desotgiu R, Matteini P, Tani C (2005) Ozone foliar symptoms in woody plants assessed with ultrastructural and fluorescence analysis. New Phytol 166:941–955Bussotti F, Desotgiu R, Cascio C, Pollastrini M, Gravano E, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Salvatori E, Manes F, Schaub M, Strasser RJ (2011a) Ozone stress in woody plants assessed with chlorophyll a fluorescence. A critical reassessment of existing data. Environ Exp Bot 73:19–30Bussotti F, Pollastrini M, Cascio C, Desotgiu R, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Pellegrini E, Carucci MG, Salvatori E, Fusaro L, Piccotto M, Malaspina P, Manfredi A, Roccotello E, Toscano S, Gottardini E, Cristofori A, Fini A, Weber D, Baldassarre V, Barbanti L, Monti A, Strasser RJ (2011b) Conclusive remarks. Reliability and comparability of chlorophyll fluorescence data from several field teams. Environ Exp Bot 73:116–119Butler WL (1978) Energy distribution in the photochemical apparatus of photosynthesis. Annu Rev Plant Physiol 29:345–378Byrdin M, Rimke I, Schlodder E, Stehlik D, Roelofs TA (2000) Decay kinetics and quantum yields of fluorescence in photosystem I from Synechococcus elongatus with P700 in the reduced and oxidized state: Are the kinetics of excited state decay trap-limited or transfer-limited? Biophys J 79:992–1007Caffarri S, Croce R, Cattivelli L, Bassi R (2004) A look within LHCII: differential analysis of the Lhcb1-3 complexes building the major trimeric antenna complex of higher-plant photosynthesis. Biochemistry 43:9467–9476Calatayud A, Ramirez JW, Iglesias DJ, Barreno E (2002) Effects of ozone on photosynthetic CO2 exchange, chlorophyll a fluorescence and antioxidant systems in lettuce leaves. Physiol Plant 116:308–316Cascio C, Schaub M, Novak K, Desotgiu R, Bussotti F, Strasser RJ (2010) Foliar responses to ozone of Fagus sylvatica L. seedlings grown in shaded and in full sunlight conditions. Environ Exp Bot 68:188–197Cazzaniga S, Dall’Osto L, Kong S-G, Wada M, Bassi R (2013) Interaction between avoidance of photon absorption, excess energy dissipation and zeaxanthin synthesis against photooxidative stress in Arabidopsis. Plant J 76:568–579Ceppi MG, Oukarroum A, Çiçek N, Strasser RJ, Schansker G (2012) The IP amplitude of the fluorescence rise OJIP is sensitive to changes in the photosystem I content of leaves: a study on plants exposed to magnesium and sulfate deficiencies, drought stress and salt stress. Physiol Plant 144:277–288Chaudhary N, Singh S, Agrawal SB, Agrawal M (2013) Assessment of six Indian cultivars of mung bean against ozone by using foliar injury index and changes in carbon assimilation, gas exchange, chlorophyll fluorescence and photosynthetic pigments. Environ Monit Assess 185:7793–7807Chen J, Kell A, Acharya K, Kupitz C, Fromme P, Jankowiak R (2015) Critical assessment of the emission spectra of various photosystem II core complexes. Photosynth Res 124:253–265Cheng L, Fuchigami LH, Breen PJ (2000) Light absorption and partitioning in relation to nitrogen content ‘Fuji’ apple leaves. J Am Soc Hortic Sci 125:581–587Choi CJ, Berges JA, Young EB (2012) Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: variable responses among freshwater microalgae. Water Res 46:2615–2626Chow WS, Aro EM (2005) Photoinactivation and mechanisms of recovery. In: Wydrzynski T, Satoh K (eds) Photosystem II: the light-driven water: plastoquinone oxidoreductase, advances in photosynthesis and respiration, vol 22. Springer, Dordrecht, pp 627–648Chow WS, Fan DY, Oguchi R, Jia H, Losciale P, Youn-Il P, He J, Öquist G, Shen YG, Anderson JM (2012) Quantifying and monitoring functional photosystem II and the stoichiometry of the two photosystems in leaf segments: approaches and approximations. Photosynth Res 113:63–74Christensen MG, Teicher HB, Streibig JC (2003) Linking fluorescence induction curve and biomass in herbicide screening. Pest Manag Sci 59:1303–1310Codrea CM, Aittokallio T, Keränen M, Tyystjärvi E, Nevalainen OS (2003) Feature learning with a genetic algorithm for fluorescence fingerprinting of plant species. Pattern Recognit Lett 24:2663–2673Conjeaud H, Mathis P (1980) The effect of pH on the reduction kinetics of P-680 in tris-treated chloroplasts. Biochim Biophys Acta 590:353–359Conrad R, Büchel C, Wilhelm C, Arsalane W, Berkaloff C, Duval JC (1993) Changes in yield of in-vivo fluorescence of chlorophyll a as a tool for selective herbicide monitoring. J Appl Phycol 5:505–516Cornic G, Massacci A (1996) Leaf photosynthesis under drought stress. In: Baker NR (ed) Photosynthesis and the environment. Kluwer Academic Publisher, Dordrecht, pp 347–366Cornic G, Fresneau C (2002) Photosynthetic carbon reduction and carbon oxidation cycles are the main electron sinks for photosystems II during a mild drought. Ann Bot 89:887–894Correia MJ, Chaves MMC, Pereira JS (1990) Afternoon depression in photosynthesis in grapevine leaves—evidence for a high light stress effect. J Exp Bot 41:417–426Cotrozzi L, Remorini D, Pellegrini E, Landi M, Massai R, Nali C, Guidi L, Lorenzini G (2016) Variations in physiological and biochemical traits of oak seedlings grown under drought and ozone stress. Physiol Plant 157:69–84Croce R, Zucchelli G, Garlaschi FM, Bassi R, Jennings RC (1997) Excited state equilibration in the photosystem I-light-harvesting I complex: P700 is almost isoenergetic with its antenna. Biochemistry 35:8572–8579Cser K, Vass I (2007) Radiative and non-radiative charge recombination pathways in photosystem II studied by thermoluminescence and chlorophyll fluorescence in the cyanobacterium Synechocystis 6308. Biochim Biophys Acta 1767:233–243Czyczyło-Mysza I, Tyrka M, Marcińska Skrzypek E, Karbarz M, Dziurka M, Hura T, Dziurka K, Quarrie SA (2013) Quantitative trait loci for leaf chlorophyll fluorescence parameters, chlorophyll and carotenoid contents in relation to biomass and yield in bread wheat and their chromosome deletion bin assignments. Mol Breed 32:189–210D’Haene SE, Sobotka R, Bučinská L, Dekker JP, Komenda J (2015) Interaction of the PsbH subunit with a chlorophyll bound to histidine 114 of CP47 is responsible for the red 77 K fluorescence of Photosystem II. Biochim Biophys Acta 1847:1327–1334Dang NC, Zazubovich V, Reppert M, Neupane B, Picorel R, Seibert M, Jankowiak R (2008) The CP43 proximal antenna complex of higher plant photosystem II revisited: modeling and hole burning study. J Phys Chem B 112:9921–9933Dau H (1994) Molecular mechanisms and quantitative models of variable Photosystem II fluorescence. Photochem Photobiol 60:1–23Dau H, Sauer K (1992) Electric field effect on the picosecond fluorescence of photosystem II and its relation to the energetics and kinetics of primary charge separation. Biochim Biophys Acta 1102:91–106Dau H, Zaharieva I, Haumann M (2012) Recent developments in research on water oxidation by photosystem II. Curr Opin Chem Biol 16:3–10de Wijn R, van Gorkom HJ (2001) Kinetics of electron transfer from QA to QB in photosystem II. Biochemistry 40:11912–11922de Wijn R, van Gorkom HJ (2002) The rate of charge recombination in photosystem II. Biochim Biophys Acta 1553:302–308Debus RJ (1992) The manganese and calcium ions of photosynthetic oxygen evolution. Biochim Biophys Acta 1102:269–352Degl’Innocenti E, Guidi L, Soldatini GF (2002) Characteriz

    Muon reconstruction and identification efficiency in ATLAS using the full Run 2 pp collision data set at \sqrt{s}=13 TeV

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    This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139 \hbox {fb}^{-1} of pp collision data at \sqrt{s}=13 TeV collected between 2015 and 2018 during Run 2 of the LHC. The increased instantaneous luminosity delivered by the LHC over this period required a reoptimisation of the criteria for the identification of prompt muons. Improved and newly developed algorithms were deployed to preserve high muon identification efficiency with a low misidentification rate and good momentum resolution. The availability of large samples of Z\rightarrow \mu \mu and J/\psi \rightarrow \mu \mu decays, and the minimisation of systematic uncertainties, allows the efficiencies of criteria for muon identification, primary vertex association, and isolation to be measured with an accuracy at the per-mille level in the bulk of the phase space, and up to the percent level in complex kinematic configurations. Excellent performance is achieved over a range of transverse momenta from 3 GeV to several hundred GeV, and across the full muon detector acceptance of |\eta |<2.7

    Measurement of the tt¯tt¯ production cross section in pp collisions at √s=13 TeV with the ATLAS detector

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    A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb−1 is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain b-hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be 26+17−15 fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be 24+7−6 fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0 ± 2.4 fb

    Measurements of Higgs bosons decaying to bottom quarks from vector boson fusion production with the ATLAS experiment at √=13TeV

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    The paper presents a measurement of the Standard Model Higgs Boson decaying to b-quark pairs in the vector boson fusion (VBF) production mode. A sample corresponding to 126 fb−1 of s√=13TeV proton–proton collision data, collected with the ATLAS experiment at the Large Hadron Collider, is analyzed utilizing an adversarial neural network for event classification. The signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model for VBF Higgs production, is measured to be 0.95+0.38−0.36 , corresponding to an observed (expected) significance of 2.6 (2.8) standard deviations from the background only hypothesis. The results are additionally combined with an analysis of Higgs bosons decaying to b-quarks, produced via VBF in association with a photon

    Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

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    This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations
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