50 research outputs found

    Effects of polylinker uATGs on the function of grass HKT1 transporters expressed in yeast cells

    Full text link
    HvHKT1 mediates K+ or Na+ uniport in yeast cells if the expression promoter is joined directly to the HvHKT1 cDNA, and Na+-K+ symport if a 59-nt polylinker is inserted. Our results show that three ATG triplets in the polylinker decreased the synthesis of the transporter and that the lower amount of transporter caused the functional change. With the rice HKT1 cDNA, the 59-nt polylinker changed the mode of Na+ uptake from K+-insensitive to K+-inhibitable. These two modes of Na+ uptake also occurred in rice plant

    Impact of cardiovascular risk factors on the clinical presentation and survival of pulmonary embolism without identifiable risk factor

    Get PDF
    Background: The nature of pulmonary embolism (PE) without identifiable risk factor (IRF) remains unclear. The objective of this study is to investigate the potential relationship between cardiovascular risk factors (CVRFs) and PE without IRF (unprovoked) and assess their role as markers of disease severity and prognosis. Methods: A case-control study was performed of patients with PE admitted to our hospital [2010-2019]. Subjects with PE without IRF were included in the cohort of cases, whereas patients with PE with IRF were allocated to the control group. Variables of interest included age, active smoking, obesity, and diagnosis of arterial hypertension, dyslipidemia or diabetes mellitus. Results: A total of 1,166 patients were included in the study, of whom 64.2% had PE without IRF. The risk for PE without IRF increased with age [odds ratio (OR): 2.68; 95% confidence interval (CI): 1.95-3.68], arterial hypertension (OR: 1.63; 95% CI: 1.27-2.07), and dyslipidemia (OR: 1.63; 95% CI: 1.24-2.15). The risk for PE without IRF was higher as the number of CVRF increased, being 3.99 (95% CI: 2.02-7.90) for subjects with >/=3 CVRF. The percentage of high-risk unprovoked PE increased significantly as the number of CVRF rose [0.6% for no CVRF; 23.8% for a CRF, P/=3, P<0.001 (OR: 14.1; 95% CI: 4.06-49.4)]. No significant differences were observed in 1-month survival between cases and controls, whereas differences in 24-month survival reached significance. Conclusions: A relationship was observed between CVRF and PE without IRF, as the risk for unprovoked PE increased with the number of CVRF. In addition, the number of CVRF was associated with PE without IRF severity, but not with prognosis

    Responses of five Mediterranean halophytes to seasonal changes in environmental conditions

    Full text link
    In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots)were able to avoid accumulation of toxic ions, maintaining relatively high K+/Na+ ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na+, Cl2, K+ and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However except for P. crassifolia proline may play a role in stress tolerance based on its osmoprotectant functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanismsThis work was funded by a grant to O.V. from the Spanish Ministry of Science and Innovation (Project CGL2008-00438/BOS), with contribution from the European Regional Development Fund.Gil Ortiz, R.; Bautista Carrascosa, I.; Boscaiu Neagu, MT.; Lidón Cerezuela, AL.; Wankhade, SD.; Sánchez Rodríguez, H.; Llinares Palacios, JV.... (2014). Responses of five Mediterranean halophytes to seasonal changes in environmental conditions. AoB PLANTS. 6:1-18. https://doi.org/10.1093/aobpla/plu049S1186Adrian-Romero, M., Wilson, S. J., Blunden, G., Yang, M.-H., Carabot-Cuervo, A., & Bashir, A. K. (1998). Betaines in coastal plants. Biochemical Systematics and Ecology, 26(5), 535-543. doi:10.1016/s0305-1978(98)00013-1Aebi, H. (1984). [13] Catalase in vitro. Oxygen Radicals in Biological Systems, 121-126. doi:10.1016/s0076-6879(84)05016-3Aghaleh, M., Niknam, V., Ebrahimzadeh, H., & Razavi, K. (2009). Salt stress effects on growth, pigments, proteins and lipid peroxidation in Salicornia persica and S. europaea. Biologia Plantarum, 53(2), 243-248. doi:10.1007/s10535-009-0046-7Aghaleh, M., Niknam, V., Ebrahimzadeh, H., & Razavi, K. (2010). Effect of salt stress on physiological and antioxidative responses in two species of Salicornia (S. persica and S. europaea). Acta Physiologiae Plantarum, 33(4), 1261-1270. doi:10.1007/s11738-010-0656-xAlbert, A., Yenush, L., Gil-Mascarell, M. ., Rodriguez, P. ., Patel, S., Martı́nez-Ripoll, M., … Serrano, R. (2000). X-ray structure of yeast hal2p, a major target of lithium and sodium toxicity, and identification of framework interactions determining cation sensitivity. Journal of Molecular Biology, 295(4), 927-938. doi:10.1006/jmbi.1999.3408Albert, R., & Popp, M. (1977). Chemical composition of halophytes from the Neusiedler Lake region in Austria. Oecologia, 27(2), 157-170. doi:10.1007/bf00345820Apel, K., & Hirt, H. (2004). REACTIVE OXYGEN SPECIES: Metabolism, Oxidative Stress, and Signal Transduction. Annual Review of Plant Biology, 55(1), 373-399. doi:10.1146/annurev.arplant.55.031903.141701Ashraf, M. (2009). Biotechnological approach of improving plant salt tolerance using antioxidants as markers. Biotechnology Advances, 27(1), 84-93. doi:10.1016/j.biotechadv.2008.09.003Ashraf, M., & Foolad, M. R. (2007). Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environmental and Experimental Botany, 59(2), 206-216. doi:10.1016/j.envexpbot.2005.12.006Bartels, D., & Sunkar, R. (2005). Drought and Salt Tolerance in Plants. Critical Reviews in Plant Sciences, 24(1), 23-58. doi:10.1080/07352680590910410Bates, L. S., Waldren, R. P., & Teare, I. D. (1973). Rapid determination of free proline for water-stress studies. Plant and Soil, 39(1), 205-207. doi:10.1007/bf00018060Bazihizina, N., Barrett-Lennard, E. G., & Colmer, T. D. (2012). Plant growth and physiology under heterogeneous salinity. Plant and Soil, 354(1-2), 1-19. doi:10.1007/s11104-012-1193-8Amor, N. B., Jimenez, A., Megdiche, W., Lundqvist, M., Sevilla, F., & Abdelly, C. (2006). Response of antioxidant systems to NaCl stress in the halophyte Cakile maritima. Physiologia Plantarum, 126(3), 446-457. doi:10.1111/j.1399-3054.2006.00620.xHamed, K. B., Ellouzi, H., Talbi, O. Z., Hessini, K., Slama, I., Ghnaya, T., … Abdelly, C. (2013). Physiological response of halophytes to multiple stresses. Functional Plant Biology, 40(9), 883. doi:10.1071/fp13074Beyer, W. F., & Fridovich, I. (1987). Assaying for superoxide dismutase activity: Some large consequences of minor changes in conditions. Analytical Biochemistry, 161(2), 559-566. doi:10.1016/0003-2697(87)90489-1Boscaiu, M., Ballesteros, G., Naranjo, M. A., Vicente, O., & Boira, H. (2011). Responses to salt stress in Juncus acutus and J. maritimus during seed germination and vegetative plant growth. Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 145(4), 770-777. doi:10.1080/11263504.2011.628446Boscaiu, M., Lull, C., Llinares, J., Vicente, O., & Boira, H. (2012). Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species. Journal of Plant Ecology, 6(2), 177-186. doi:10.1093/jpe/rts017Boyer, J. S. (1982). Plant Productivity and Environment. Science, 218(4571), 443-448. doi:10.1126/science.218.4571.443Bradford, M. M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry, 72(1-2), 248-254. doi:10.1016/0003-2697(76)90527-3Bressan, R. A., Hasegawa, P. M., & Pardo, J. M. (1998). Plants use calcium to resolve salt stress. Trends in Plant Science, 3(11), 411-412. doi:10.1016/s1360-1385(98)01331-4Cavalieri, A. J. (1983). Proline and glycinebetaine accumulation by Spartina alterniflora Loisel. in response to NaCl and nitrogen in a controlled environment. Oecologia, 57(1-2), 20-24. doi:10.1007/bf00379556Chen, T. H. H., & Murata, N. (2008). Glycinebetaine: an effective protectant against abiotic stress in plants. Trends in Plant Science, 13(9), 499-505. doi:10.1016/j.tplants.2008.06.007Connell, J. P., & Mullet, J. E. (1986). Pea Chloroplast Glutathione Reductase: Purification and Characterization. Plant Physiology, 82(2), 351-356. doi:10.1104/pp.82.2.351Del Rio, D., Stewart, A. J., & Pellegrini, N. (2005). A review of recent studies on malondialdehyde as toxic molecule and biological marker of oxidative stress. Nutrition, Metabolism and Cardiovascular Diseases, 15(4), 316-328. doi:10.1016/j.numecd.2005.05.003Demiral, T., & Türkan, I. (2004). Does exogenous glycinebetaine affect antioxidative system of rice seedlings under NaCl treatment? Journal of Plant Physiology, 161(10), 1089-1100. doi:10.1016/j.jplph.2004.03.009Doddema, H., Saad Eddin, R., & Mahasneh, A. (1986). Effects of seasonal changes of soil salinity and soil nitrogen on the N-metabolism of the halophyteArthrocnemum fruticosum (L.) Moq. Plant and Soil, 92(2), 279-293. doi:10.1007/bf02372641FEDOROFF, N. (2006). Redox Regulatory Mechanisms in Cellular Stress Responses. Annals of Botany, 98(2), 289-300. doi:10.1093/aob/mcl128Flowers, T. J., & Colmer, T. D. (2008). Salinity tolerance in halophytes*. New Phytologist, 179(4), 945-963. doi:10.1111/j.1469-8137.2008.02531.xFlowers, T. J., Troke, P. F., & Yeo, A. R. (1977). The Mechanism of Salt Tolerance in Halophytes. Annual Review of Plant Physiology, 28(1), 89-121. doi:10.1146/annurev.pp.28.060177.000513Flowers, T. J., Galal, H. K., & Bromham, L. (2010). Evolution of halophytes: multiple origins of salt tolerance in land plants. Functional Plant Biology, 37(7), 604. doi:10.1071/fp09269Gagneul, D., Aïnouche, A., Duhazé, C., Lugan, R., Larher, F. R., & Bouchereau, A. (2007). A Reassessment of the Function of the So-Called Compatible Solutes in the Halophytic Plumbaginaceae Limonium latifolium. Plant Physiology, 144(3), 1598-1611. doi:10.1104/pp.107.099820Gil, R., Boscaiu, M., Lull, C., Bautista, I., Lidón, A., & Vicente, O. (2013). Are soluble carbohydrates ecologically relevant for salt tolerance in halophytes? Functional Plant Biology, 40(9), 805. doi:10.1071/fp12359Glenn, E. (1999). Salt Tolerance and Crop Potential of Halophytes. Critical Reviews in Plant Sciences, 18(2), 227-255. doi:10.1016/s0735-2689(99)00388-3Grieve, C. M., & Grattan, S. R. (1983). Rapid assay for determination of water soluble quaternary ammonium compounds. Plant and Soil, 70(2), 303-307. doi:10.1007/bf02374789Halliwell, B. (2006). Reactive Species and Antioxidants. Redox Biology Is a Fundamental Theme of Aerobic Life. Plant Physiology, 141(2), 312-322. doi:10.1104/pp.106.077073HAUSER, F., & HORIE, T. (2010). A conserved primary salt tolerance mechanism mediated by HKT transporters: a mechanism for sodium exclusion and maintenance of high K+/Na+ratio in leaves during salinity stress. Plant, Cell & Environment, 33(4), 552-565. doi:10.1111/j.1365-3040.2009.02056.xHodges, D. M., DeLong, J. M., Forney, C. F., & Prange, R. K. (1999). Improving the thiobarbituric acid-reactive-substances assay for estimating lipid peroxidation in plant tissues containing anthocyanin and other interfering compounds. Planta, 207(4), 604-611. doi:10.1007/s004250050524Horie, T., Hauser, F., & Schroeder, J. I. (2009). HKT transporter-mediated salinity resistance mechanisms in Arabidopsis and monocot crop plants. Trends in Plant Science, 14(12), 660-668. doi:10.1016/j.tplants.2009.08.009Katschnig, D., Broekman, R., & Rozema, J. (2013). Salt tolerance in the halophyte Salicornia dolichostachya Moss: Growth, morphology and physiology. Environmental and Experimental Botany, 92, 32-42. doi:10.1016/j.envexpbot.2012.04.002Ajmal Khan, M., Ungar, I. A., & Showalter, A. M. (2000). The effect of salinity on the growth, water status, and ion content of a leaf succulent perennial halophyte, Suaeda fruticosa (L.) Forssk. Journal of Arid Environments, 45(1), 73-84. doi:10.1006/jare.1999.0617Koiwa, H., Bressan, R. A., & Hasegawa, P. M. (2006). Identification of plant stress-responsive determinants in arabidopsis by large-scale forward genetic screens. Journal of Experimental Botany, 57(5), 1119-1128. doi:10.1093/jxb/erj093Krasensky, J., & Jonak, C. (2012). Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks. Journal of Experimental Botany, 63(4), 1593-1608. doi:10.1093/jxb/err460Kronzucker, H. J., & Britto, D. T. (2010). Sodium transport in plants: a critical review. New Phytologist, 189(1), 54-81. doi:10.1111/j.1469-8137.2010.03540.xLi, G., Wan, S., Zhou, J., Yang, Z., & Qin, P. (2010). Leaf chlorophyll fluorescence, hyperspectral reflectance, pigments content, malondialdehyde and proline accumulation responses of castor bean (Ricinus communis L.) seedlings to salt stress levels. Industrial Crops and Products, 31(1), 13-19. doi:10.1016/j.indcrop.2009.07.015Li, Y. (2008). Kinetics of the antioxidant response to salinity in the halophyte Limonium bicolour. Plant, Soil and Environment, 54(No. 11), 493-497. doi:10.17221/434-pseMiller, G., Shulaev, V., & Mittler, R. (2008). Reactive oxygen signaling and abiotic stress. Physiologia Plantarum, 133(3), 481-489. doi:10.1111/j.1399-3054.2008.01090.xMILLER, G., SUZUKI, N., CIFTCI-YILMAZ, S., & MITTLER, R. (2010). Reactive oxygen species homeostasis and signalling during drought and salinity stresses. Plant, Cell & Environment, 33(4), 453-467. doi:10.1111/j.1365-3040.2009.02041.xMoghaieb, R. (2004). Effect of salinity on osmotic adjustment, glycinebetaine accumulation and the betaine aldehyde dehydrogenase gene expression in two halophytic plants, Salicornia europaea and Suaeda maritima. Plant Science, 166(5), 1345-1349. doi:10.1016/j.plantsci.2004.01.016Mouri, C., Benhassaini, H., Bendimered, F. Z., & Belkhodja, M. (2012). Variation saisonnière de la teneur en proline et en sucres solubles chez l’oyat (Ammophila arenaria(L.) Link) provenant du milieu naturel de la côte ouest de l’Algérie. Acta Botanica Gallica, 159(1), 127-135. doi:10.1080/12538078.2012.673822Munns, R., & Termaat, A. (1986). Whole-Plant Responses to Salinity. Functional Plant Biology, 13(1), 143. doi:10.1071/pp9860143Munns, R., & Tester, M. (2008). Mechanisms of Salinity Tolerance. Annual Review of Plant Biology, 59(1), 651-681. doi:10.1146/annurev.arplant.59.032607.092911Murakeözy, É. P., Smirnoff, N., Nagy, Z., & Tuba, Z. (2002). Seasonal accumulation pattern of pinitol and other carbohydrates in Limonium gmelini subsp. hungarica. Journal of Plant Physiology, 159(5), 485-490. doi:10.1078/0176-1617-00617Murakeözy, É. P., Nagy, Z., Duhazé, C., Bouchereau, A., & Tuba, Z. (2003). Seasonal changes in the levels of compatible osmolytes in three halophytic species of inland saline vegetation in Hungary. Journal of Plant Physiology, 160(4), 395-401. doi:10.1078/0176-1617-00790Nawaz, K., & Ashraf, M. (2010). Exogenous Application of Glycinebetaine Modulates Activities of Antioxidants in Maize Plants Subjected to Salt Stress. Journal of Agronomy and Crop Science, 196(1), 28-37. doi:10.1111/j.1439-037x.2009.00385.xNiu, X., Bressan, R. A., Hasegawa, P. M., & Pardo, J. M. (1995). Ion Homeostasis in NaCl Stress Environments. Plant Physiology, 109(3), 735-742. doi:10.1104/pp.109.3.735Ozgur, R., Uzilday, B., Sekmen, A. H., & Turkan, I. (2013). Reactive oxygen species regulation and antioxidant defence in halophytes. Functional Plant Biology, 40(9), 832. doi:10.1071/fp12389Parida, A. K., Das, A. B., & Mohanty, P. (2004). Defense potentials to NaCl in a mangrove, Bruguiera parviflora: Differential changes of isoforms of some antioxidative enzymes. Journal of Plant Physiology, 161(5), 531-542. doi:10.1078/0176-1617-01084Popp, M., & Polania, J. (1989). Compatible solutes in different organs of mangrove trees. Annales des Sciences Forestières, 46(Supplement), 842s-844s. doi:10.1051/forest:198905art0185Redondo-Gómez, S., Wharmby, C., Castillo, J. M., Mateos-Naranjo, E., Luque, C. J., de Cires, A., … Enrique Figueroa, M. (2006). Growth and photosynthetic responses to salinity in an extreme halophyte, Sarcocornia fruticosa. Physiologia Plantarum, 128(1), 116-124. doi:10.1111/j.1399-3054.2006.00719.xRENGEL, Z. (1992). The role of calcium in salt toxicity. Plant, Cell and Environment, 15(6), 625-632. doi:10.1111/j.1365-3040.1992.tb01004.xRodríguez-Navarro, A., & Rubio, F. (2006). High-affinity potassium and sodium transport systems in plants. Journal of Experimental Botany, 57(5), 1149-1160. doi:10.1093/jxb/erj068Hediye Sekmen, A., Türkan, İ., & Takio, S. (2007). Differential responses of antioxidative enzymes and lipid peroxidation to salt stress in salt-tolerant Plantago maritima and salt-sensitive Plantago media. Physiologia Plantarum, 131(3), 399-411. doi:10.1111/j.1399-3054.2007.00970.xSHORT, D. (1999). Salt Tolerance in the HalophyteHalosarcia pergranulatasubsp.pergranulata. Annals of Botany, 83(3), 207-213. doi:10.1006/anbo.1998.0812Szabados, L., & Savouré, A. (2010). Proline: a multifunctional amino acid. Trends in Plant Science, 15(2), 89-97. doi:10.1016/j.tplants.2009.11.009Tipirdamaz, R., Gagneul, D., Duhazé, C., Aïnouche, A., Monnier, C., Özkum, D., & Larher, F. (2006). Clustering of halophytes from an inland salt marsh in Turkey according to their ability to accumulate sodium and nitrogenous osmolytes. Environmental and Experimental Botany, 57(1-2), 139-153. doi:10.1016/j.envexpbot.2005.05.007Türkan, I., & Demiral, T. (2009). Recent developments in understanding salinity tolerance. Environmental and Experimental Botany, 67(1), 2-9. doi:10.1016/j.envexpbot.2009.05.008Vicente, O., Boscaiu, M., Naranjo, M. Á., Estrelles, E., Bellés, J. M., & Soriano, P. (2004). Responses to salt stress in the halophyte Plantago crassifolia (Plantaginaceae). Journal of Arid Environments, 58(4), 463-481. doi:10.1016/j.jaridenv.2003.12.003Walker, D. J., Romero, P., de Hoyos, A., & Correal, E. (2008). Seasonal changes in cold tolerance, water relations and accumulation of cations and compatible solutes in Atriplex halimus L. Environmental and Experimental Botany, 64(3), 217-224. doi:10.1016/j.envexpbot.2008.05.012Watson, E. B., & Byrne, R. (2009). Abundance and diversity of tidal marsh plants along the salinity gradient of the San Francisco Estuary: implications for global change ecology. Plant Ecology, 205(1), 113-128. doi:10.1007/s11258-009-9602-7Weimberg, R. (1987). Solute adjustments in leaves of two species of wheat at two different stages of growth in response to salinity. Physiologia Plantarum, 70(3), 381-388. doi:10.1111/j.1399-3054.1987.tb02832.xZhishen, J., Mengcheng, T., & Jianming, W. (1999). The determination of flavonoid contents in mulberry and their scavenging effects on superoxide radicals. Food Chemistry, 64(4), 555-559. doi:10.1016/s0308-8146(98)00102-2Zhu, J.-K. (2000). Genetic Analysis of Plant Salt Tolerance Using Arabidopsis: Fig. 1. Plant Physiology, 124(3), 941-948. doi:10.1104/pp.124.3.941Zhu, J.-K. (2001). Plant salt tolerance. Trends in Plant Science, 6(2), 66-71. doi:10.1016/s1360-1385(00)01838-0Zhu, J.-K. (2002). SALT ANDDROUGHTSTRESSSIGNALTRANSDUCTION INPLANTS. Annual Review of Plant Biology, 53(1), 247-273. doi:10.1146/annurev.arplant.53.091401.14332

    Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

    Get PDF
    Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

    Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector

    Get PDF
    Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. A measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and pp collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of 208 mu b(-1) and 38 mu b(-1), respectively, and pp data with a sampled integrated luminosity of 1.17 pb(-1) were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in pp collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval vertical bar eta vertical bar &lt; 2. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The bottom muon results are the most precise measurement of b quark nuclear modification at low transverse momentum where reconstruction of B hadrons is challenging. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays

    A search for an unexpected asymmetry in the production of e+μ− and e−μ+ pairs in proton-proton collisions recorded by the ATLAS detector at root s = 13 TeV

    Get PDF
    This search, a type not previously performed at ATLAS, uses a comparison of the production cross sections for e(+)mu(-) and e(-)mu(+) pairs to constrain physics processes beyond the Standard Model. It uses 139 fb(-1) of proton-proton collision data recorded at root s = 13 TeV at the LHC. Targeting sources of new physics which prefer final states containing e(+)mu(-) and e(-)mu(+), the search contains two broad signal regions which are used to provide model-independent constraints on the ratio of cross sections at the 2% level. The search also has two special selections targeting supersymmetric models and leptoquark signatures. Observations using one of these selections are able to exclude, at 95% confidence level, singly produced smuons with masses up to 640 GeV in a model in which the only other light sparticle is a neutralino when the R-parity-violating coupling lambda(23)(1)' is close to unity. Observations using the other selection exclude scalar leptoquarks with masses below 1880 GeV when g(1R)(eu) = g(1R)(mu c) = 1, at 95% confidence level. The limit on the coupling reduces to g(1R)(eu) = g(1R)(mu c) = 0.46 for a mass of 1420 GeV

    Parque educativo y de oficios rio Combeima. Un aporte a la cultura en la ciudad de Ibagu? en la comuna 12 barrio el Combeima para el a?o 2017

    No full text
    135 p. Recurso Electr?nicoEl objeto de este trabajo de grado es el dise?o del parque educativo y de oficios a la ribera del rio Combeima en la comuna 12 de la ciudad de Ibagu?. Consiste entonces en un proceso anal?tico y de estudios, respaldado por datos e informes escritos y orales con el fin de suplir las necesidades del sector, entendiendo la escala del proceso y los lineamientos a seguir. Para el desarrollo de dicho proyecto se estructura la f?rmula de cultura es igual a la combinaci?n de Deporte, Educaci?n y Formaci?n. A ra?z de dicha f?rmula se plantea entonces la divisi?n del proyecto en tres tramos. Tramo 1: En el primer tramo se formula la zona educativa, conformada principalmente por una biblioteca y una guarder?a, consta con m?ltiples espacios complementarios que se aprovechan a trav?s de senderos, zonas verdes espacios deportivos para j?venes y zonas de descanso, esta zona surge de la interpretaci?n de la basta poblaci?n infantil que presenta el sector, brindando espacios de calidad y que fomenten las primeras nociones de cultura en la juventud, promoviendo un futuro con esperanza para los habitantes. Tramo 2: Constituye la zona deportiva del parque, es el espacio articulador entre los infantes y los mayores, dedicado a promover los espacios saludables y deportivos. Tramo 3: En este tramo se presentan espacios para las personas adultas, en los cuales se brindan talleres de formaci?n en oficios varios. Palabras claves: Ribera, Rio, Combeima, Deporte, Educaci?n, Formaci?n, Cultura.Consists of an analytical process and studies of different written and oral data and reports, all this in order to identify the necessities of the sector, the scale of the project and the following steps and activities to develop. For the development of such project was structured the formula: Culture as the combination of Sports, Education and Training. Because of this formula, the project was divided into three sections: Section 1: In the first section is formulated the educational area, mainly consisting of a library and a kindergarten, it has several complementary spaces implemented in trails, green areas, sports spaces for young people and rest areas. The reason of this section is the large child population in the area, and the idea of provide quality environment that will give them a notion of culture and hope. Section 2: It is the sports area of the park and it is the space between the child and young people. Mainly focus to promote a healthy and sporting space. Section 3: This space is for the adult?s population, which provide workshops of different areas. Keyword: Riverside, river, Combeima, sport, education, training, culture
    corecore