286,570 research outputs found
Masses and decay constants of D*(s) and B*(s) mesons with Nf=2+1+1 twisted mass fermions
No full textWe present a lattice calculation of the masses and decay constants of D*(s) and B*(s) mesons using the gauge configurations produced by the European Twisted Mass Collaboration (ETMC) with Nf=2+1+1 dynamical quarks at three values of the lattice spacing a~(0.06-0.09) fm. Pion masses are simulated in the range Mpi=(210-450) MeV, while the strange and charm sea-quark masses are close to their physical values. We compute the ratios of vector to pseudoscalar masses and decay constants for various values of the heavy-quark mass mh in the range 0.7mcphysmh3mcphys. In order to reach the physical b-quark mass, we exploit the heavy quark effective theory prediction that, in the static limit of infinite heavy-quark mass, the considered ratios are equal to one. At the physical point our results are MD*/MD=1.0769(79), MD*sMDs=1.0751(56), fD*/fD=1.078(36), fD*s/fDs=1.087(20), MB*/MB=1.0078(15), MB*s/MBs=1.0083(10), fB*/fB=0.958(22) and fB*s/fBs=0.974(10). Combining them with the experimental values of the pseudoscalar meson masses (used as input to fix the quark masses) and the values of the pseudoscalar decay constants calculated by ETMC, we get MD*=2013(14), MD*s=2116(11), fD*=223.5(8.4), fD*s=268.8(6.6), MB*=5320.5(7.6), MB*s=5411.36(5.3), fB*=185.9(7.2) and fB*s=223.1(5.4) MeV
Masses, decay constants and HQE matrix elements of pseudoscalar and vector heavy-light mesons in LQCD
No full textWe present a precise lattice computation of masses and decay constants of pseudoscalar and vector heavy-light mesons with m l = m u/d, m s and m h in the range (m c, ∼ 3m c). We employ the ETMC gauge configurations with both N f = 2 and N f = 2 + 1 + 1 dynamical quarks and the ETMC ratio method to reach the b-quark mass. In the case of the vector decay constants an unusual quenching effect of the strange quark is observed. Specific masses combinations are then analyzed in terms of the Heavy Quark Expansion (HQE) to extract matrix elements up to dimension-6, including , and and with a good precision. These parameters play a crucial role in the inclusive determination of the V ub and V cb matrix elements
Neutron electric dipole moment on the lattice: a theoretical reappraisal
No full textWe present a strategy for a lattice evaluation of the neutron electric dipole moment induced by the strong CP violating term of the QCD lagrangian. Our strategy is based on the standard definition of the electric dipole moment, involving the charge density operator J(0), in case of three flavors with non-degenerate masses. We present a complete diagrammatic analysis showing how the axial chiral Ward identities can be used to replace the topological charge operator with the flavor-singlet pseudoscalar density P-S. Our final result is characterized only by disconnected diagrams, where the disconnected part can be either the single insertion of P-S or the separate insertions of both P-S and J(0). The applicability of our strategy to the case of lattice formulations that explicitly break chiral symmetry, like the Wilson and Clover actions, is discussed
Electromagnetic Form Factor of the Pion from Twisted-mass Lattice QCD at Nf=2
No full textWe present a lattice calculation of the electromagnetic form factor of the pion obtained using the tree-level Symanzik improved gauge action with two flavors of dynamical twisted Wilson quarks. The simulated pion masses range approximately from 260 to 580 MeV, and the lattice box sizes are chosen in order to guarantee that Mpi*L>~4. Accurate results for the form factor are obtained using all-to-all quark propagators evaluated by a stochastic procedure. The momentum dependence of the pion form factor is investigated up to values of the squared four-momentum transfer Q^2~=0.8 GeV^2 and, thanks to the use of twisted boundary conditions, down to Q^2~=0.05 GeV^2. Volume and discretization effects on the form factor appear to be within the statistical errors. Our results for the pion mass, decay constant and form factor are analyzed using (continuum) chiral perturbation theory at next-to-next-to-leading order. The extrapolated value of the pion charge radius is <r2>_phys=0.456±0.030(stat)±0.024(syst) in nice agreement with the experimental result. The extrapolated values of the pion form factor agree very well with the experimental data up to Q^2~=0.8 GeV^2 within uncertainties which become competitive with the experimental errors for Q^2>~0.3 GeV^2. The relevant low-energy constants appearing in the chiral expansion of the pion form factor are extracted from our lattice data, which come essentially from a single lattice spacing, adding the experimental value of the pion scalar radius in the fitting procedure. Our findings are in nice agreement with the available results of chiral perturbation theory analyses of pi-pi scattering data as well as with other analyses of our collaboration
Monitoring the mitochondrial dynamics in mammalian cells
No full textMitochondria exist in a dynamic state inside mammalian cells. They undergo processes of fusion and fission to adjust their shape according to the different cell needs. Different proteins tightly regulate these dynamics: Opa-1 and Mitofusin-1 and Mitofusin-2 are the main profusion proteins, while Drp1 and its different receptors (Mff, Fis1, MiD49, MiD51) regulate mitochondrial fission. The dynamic nature of the mitochondrial network has become evident and detectable, thanks to recent advances in live imaging video microscopy and to the availability of mitochondria-tagged fluorescent proteins. High-resolution confocal reconstruction of mitochondria over time allows researchers to visualize mitochondria shape changes in living cells, under different experimental conditions. Moreover, in recent years, different techniques in living cells have been developed to study the process of mitochondria fusion in more details. Among them are fluorescence recovery after photobleaching (FRAP) of mitochondria-tagged GFP (mtGFP), use of photoactivatable mtGFP, polyethylene glycol (PEG)-based fusion of mtGFP and mtRFP cells, and Renilla luciferase assay (for population studies). In addition, in combination with imaging, the analysis of the expression levels of the different mitochondria-shaping proteins, along with that of their activation status, represents a powerful tool to investigate potential modulations of the mitochondrial network. Here, we review this aspect and then mention a number of techniques, with particular attention to their relative protocols
The nucleon Drell-Hearn-Gerasimov sum rule within a relativistic constituent quark model
No full textWe investigate the Drell-Hearn-Gerasimov sum rule within a relativistic constituent quark model based on the light-front formalism.The contribution of the nucleon to Delta transition is explicitly evaluated using different forms of the baryon wave functions and adopting a one-body relativistic current which includes Dirac and Pauli form factors for the constituent quark
Trust your back : classification-based care for low back pain in primary care
No full textAbstract
Low back pain (LBP), mostly a non-specific symptom, is a leading cause of years lived with disability: multiple biological, psychological, social and lifestyle factors lead to pain-related disability and use of healthcare. Evidence-based care for LBP comprises active treatments that address biopsychosocial factors and focus on improving functioning, self-management, education, and advice to stay active, also at work. The STarT Back Tool (SBT) and the Örebro Musculoskeletal Pain Screening Questionnaire Short Form (ÖMPSQ-SF) were created to enable easy and systematic identification of predictive psychosocial and symptom-related factors. The patient education booklet was designed to support evidence-based care and reduce inappropriate imaging.
The study aim was to evaluate the concordance of the SBT and ÖMPSQ-SF and the accumulation of psychiatric, psychological, lifestyle, and social risk factors in the high-risk groups of both questionnaires among population with LBP. We also aimed to translate and validate the patient education booklet. We separately assessed the effectiveness of the patient education booklet and the classification-based approach to LBP care in primary care and compared it to that of usual care.
SBT and ÖMPSQ-SF were compared in a population-based study using the Northern Finland Birth Cohort 1966. The preliminary evaluation of the patient education booklet was obtained using web-based questionnaires. A cluster randomised study evaluated the effectiveness of the patient education booklet, and a Benchmarking Controlled Trial evaluated the effectiveness of a classification-based approach to LBP care in primary care.
Individual psychological and social risk factors accumulated among the high-risk groups of the SBT and the ÖMPSQ-SF. The education booklet helped patients understand their pain, encouraged them to be physically active, decreased imaging and the number of LBP-related sick leave days. Although classification-based care did not seem to influence physical functioning in the long term, pain was alleviated more quickly, and the use of healthcare services and number of back-related sick leave days decreased in the intervention group.
A combination of education for healthcare professionals, classification-based care using the SBT, and systematic use of the patient education booklet seems to bring value to LBP care in primary healthcare. Original papers Simula, A. S., Ruokolainen, O., Oura, P., Lausmaa, M., Holopainen, R., Paukkunen, M., Auvinen, J., Linton, S. J., Hill, J. C., & Karppinen, J. (2020). Association of STarT Back Tool and the short form of the Örebro Musculoskeletal Pain Screening Questionnaire with multidimensional risk factors. Scientific Reports, 10(1), 290. https://doi.org/10.1038/s41598-019-57105-3 https://doi.org/10.1038/s41598-019-57105-3 Self-archived version Simula, A. S., Jenkins, H. J., Holopainen, R., Oura, P., Korniloff, K., Häkkinen, A., Takala, E.-P., Hancock, M. J., & Karppinen, J. (2019). Transcultural adaption and preliminary evaluation of “understanding low back pain” patient education booklet. BMC Health Services Research, 19(1), 1010. https://doi.org/10.1186/s12913-019-4854-y https://doi.org/10.1186/s12913-019-4854-y Self-archived version Simula, A. S., Jenkins, H. J., Hancock, M. J., Malmivaara, A., Booth, N., & Karppinen, J. (2021). Patient education booklet to support evidence-based low back pain care in primary care – a cluster randomized controlled trial. BMC Family Practice, 22(1), 178. https://doi.org/10.1186/s12875-021-01529-2 https://doi.org/10.1186/s12875-021-01529-2 Self-archived version Simula, A. S., Malmivaara, A., Booth, N., & Karppinen, J. (2020). A classification-based approach to low back pain in primary care – protocol for a benchmarking controlled trial. BMC Family Practice, 21(1), 61. https://doi.org/10.1186/s12875-020-01135-8 https://doi.org/10.1186/s12875-020-01135-8 Self-archived version Simula, A. S., Malmivaara, A., Booth, N., & Karppinen, J. (2024). Effectiveness of a classification-based approach to low back pain in primary care – a benchmarking controlled trial. Journal of Rehabilitation Medicine, 56, jrm28321. https://doi.org/10.2340/jrm.v56.28321 https://doi.org/10.2340/jrm.v56.28321 Self-archived version Tiivistelmä
Alaselkäkipu on yleisin haittaa aiheuttava vaiva, enimmäkseen epäspesifi oire, jossa monet biologiset, psykologiset, sosiaaliset ja elintapatekijät vaikuttavat kipuun liittyvään haittaan ja terveyspalveluiden käyttöön. Näyttöön perustuva alaselkäkivun hoito on aktiivista ja huomioi biopsykososiaaliset tekijät. Hoidon keskiössä on toimintakyvyn parantaminen, omahoito, ohjaus ja neuvonta sekä ohje pysyä aktiivisena työ mukaan lukien. STarT-selkäkysely (SBT) ja Örebro-kipukysely (ÖMPSQ-SF) on kehitetty auttamaan ennustavien psykososiaalisten ja oireeseen liittyvien tekijöiden tunnistamisessa. Uusi potilasopas on kehitetty tukemaan näyttöön perustuvaa hoitoa ja vähentämään tarpeetonta kuvantamista.
Tavoitteemme oli arvioida SBT ja ÖMPSQ-SF yhdenmukaisuutta sekä psykiatristen, psykologisten, elintapaan liittyvien ja sosiaalisten riskitekijöiden kasautumista molempien kyselyiden korkeaan riskiryhmään alaselkäkipuisessa väestössä. Tavoitteena oli myös kääntää ja validoida uusi potilasopas suomeksi. Lisäksi arvioimme erikseen potilasoppaan vaikuttavuutta ja luokitteluun perustuvan hoitomallin vaikuttavuutta alaselkäkipupotilaiden hoidossa perusterveydenhuollossa.
SBT ja ÖMPSQ-SF vertailtiin väestöaineistossa käyttäen Pohjois-Suomen syntymäkohortti 1966 aineistoa. Alustava arvio potilasoppaasta tehtiin nettikyselyillä. Ryvässatunnaistetussa asetelmassa tutkittiin potilasoppaan vaikuttavuutta ja vertaiskontrolloidussa asetelmassa luokitteluun perustuvan hoitomallin jalkauttamisen vaikuttavuutta alaselkäkivun hoidossa perusterveydenhuollossa.
Yksilölliset psykologiset ja sosiaaliset riskitekijät kasautuivat SBT ja ÖMPSQ-SF korkean riskin ryhmiin. Potilasopas auttoi potilaita ymmärtämään heidän kipuansa, rohkaisi heitä olemaan fyysisesti aktiivisia ja vähensi alaselän kuvantamistutkimuksia sekä sairauslomapäiviä. Vaikka luokitteluun perustuva hoitomalli ei vaikuttanut fyysiseen toimintakykyyn pitkällä aikavälillä, kipuoireet näyttivät paranevan nopeammin, terveyspalvelujen käyttö oli vähäisempää ja selkäkipuun liittyvien sairaslomapäivien määrä oli pienempi interventioryhmässä.
Yhdessä terveydenhuollon ammattilaisten koulutus, luokitteluun perustuva alaselkäkipupotilaiden hoito STarT-selkäkyselyä käyttäen ja systemaattinen potilasoppaan käyttö näytti edistävän alaselkäkipupotilaiden hoitoa perusterveydenhuollossa. Osajulkaisut Simula, A. S., Ruokolainen, O., Oura, P., Lausmaa, M., Holopainen, R., Paukkunen, M., Auvinen, J., Linton, S. J., Hill, J. C., & Karppinen, J. (2020). Association of STarT Back Tool and the short form of the Örebro Musculoskeletal Pain Screening Questionnaire with multidimensional risk factors. Scientific Reports, 10(1), 290. https://doi.org/10.1038/s41598-019-57105-3 https://doi.org/10.1038/s41598-019-57105-3 Rinnakkaistallennettu versio Simula, A. S., Jenkins, H. J., Holopainen, R., Oura, P., Korniloff, K., Häkkinen, A., Takala, E.-P., Hancock, M. J., & Karppinen, J. (2019). Transcultural adaption and preliminary evaluation of “understanding low back pain” patient education booklet. BMC Health Services Research, 19(1), 1010. https://doi.org/10.1186/s12913-019-4854-y https://doi.org/10.1186/s12913-019-4854-y Rinnakkaistallennettu versio Simula, A. S., Jenkins, H. J., Hancock, M. J., Malmivaara, A., Booth, N., & Karppinen, J. (2021). Patient education booklet to support evidence-based low back pain care in primary care – a cluster randomized controlled trial. BMC Family Practice, 22(1), 178. https://doi.org/10.1186/s12875-021-01529-2 https://doi.org/10.1186/s12875-021-01529-2 Rinnakkaistallennettu versio Simula, A. S., Malmivaara, A., Booth, N., & Karppinen, J. (2020). A classification-based approach to low back pain in primary care – protocol for a benchmarking controlled trial. BMC Family Practice, 21(1), 61. https://doi.org/10.1186/s12875-020-01135-8 https://doi.org/10.1186/s12875-020-01135-8 Rinnakkaistallennettu versio Simula, A. S., Malmivaara, A., Booth, N., & Karppinen, J. (2024). Effectiveness of a classification-based approach to low back pain in primary care – a benchmarking controlled trial. Journal of Rehabilitation Medicine, 56, jrm28321. https://doi.org/10.2340/jrm.v56.28321 https://doi.org/10.2340/jrm.v56.28321 Rinnakkaistallennettu versio Academic dissertation to be presented with the assent of the Doctoral Programme Committee of Health and Biosciences of the University of Oulu for public defence in MKS Auditorium (Mikkeli), on 13 December 2024, at 12 noonAbstract
Low back pain (LBP), mostly a non-specific symptom, is a leading cause of years lived with disability: multiple biological, psychological, social and lifestyle factors lead to pain-related disability and use of healthcare. Evidence-based care for LBP comprises active treatments that address biopsychosocial factors and focus on improving functioning, self-management, education, and advice to stay active, also at work. The STarT Back Tool (SBT) and the Örebro Musculoskeletal Pain Screening Questionnaire Short Form (ÖMPSQ-SF) were created to enable easy and systematic identification of predictive psychosocial and symptom-related factors. The patient education booklet was designed to support evidence-based care and reduce inappropriate imaging.
The study aim was to evaluate the concordance of the SBT and ÖMPSQ-SF and the accumulation of psychiatric, psychological, lifestyle, and social risk factors in the high-risk groups of both questionnaires among population with LBP. We also aimed to translate and validate the patient education booklet. We separately assessed the effectiveness of the patient education booklet and the classification-based approach to LBP care in primary care and compared it to that of usual care.
SBT and ÖMPSQ-SF were compared in a population-based study using the Northern Finland Birth Cohort 1966. The preliminary evaluation of the patient education booklet was obtained using web-based questionnaires. A cluster randomised study evaluated the effectiveness of the patient education booklet, and a Benchmarking Controlled Trial evaluated the effectiveness of a classification-based approach to LBP care in primary care.
Individual psychological and social risk factors accumulated among the high-risk groups of the SBT and the ÖMPSQ-SF. The education booklet helped patients understand their pain, encouraged them to be physically active, decreased imaging and the number of LBP-related sick leave days. Although classification-based care did not seem to influence physical functioning in the long term, pain was alleviated more quickly, and the use of healthcare services and number of back-related sick leave days decreased in the intervention group.
A combination of education for healthcare professionals, classification-based care using the SBT, and systematic use of the patient education booklet seems to bring value to LBP care in primary healthcare.Tiivistelmä
Alaselkäkipu on yleisin haittaa aiheuttava vaiva, enimmäkseen epäspesifi oire, jossa monet biologiset, psykologiset, sosiaaliset ja elintapatekijät vaikuttavat kipuun liittyvään haittaan ja terveyspalveluiden käyttöön. Näyttöön perustuva alaselkäkivun hoito on aktiivista ja huomioi biopsykososiaaliset tekijät. Hoidon keskiössä on toimintakyvyn parantaminen, omahoito, ohjaus ja neuvonta sekä ohje pysyä aktiivisena työ mukaan lukien. STarT-selkäkysely (SBT) ja Örebro-kipukysely (ÖMPSQ-SF) on kehitetty auttamaan ennustavien psykososiaalisten ja oireeseen liittyvien tekijöiden tunnistamisessa. Uusi potilasopas on kehitetty tukemaan näyttöön perustuvaa hoitoa ja vähentämään tarpeetonta kuvantamista.
Tavoitteemme oli arvioida SBT ja ÖMPSQ-SF yhdenmukaisuutta sekä psykiatristen, psykologisten, elintapaan liittyvien ja sosiaalisten riskitekijöiden kasautumista molempien kyselyiden korkeaan riskiryhmään alaselkäkipuisessa väestössä. Tavoitteena oli myös kääntää ja validoida uusi potilasopas suomeksi. Lisäksi arvioimme erikseen potilasoppaan vaikuttavuutta ja luokitteluun perustuvan hoitomallin vaikuttavuutta alaselkäkipupotilaiden hoidossa perusterveydenhuollossa.
SBT ja ÖMPSQ-SF vertailtiin väestöaineistossa käyttäen Pohjois-Suomen syntymäkohortti 1966 aineistoa. Alustava arvio potilasoppaasta tehtiin nettikyselyillä. Ryvässatunnaistetussa asetelmassa tutkittiin potilasoppaan vaikuttavuutta ja vertaiskontrolloidussa asetelmassa luokitteluun perustuvan hoitomallin jalkauttamisen vaikuttavuutta alaselkäkivun hoidossa perusterveydenhuollossa.
Yksilölliset psykologiset ja sosiaaliset riskitekijät kasautuivat SBT ja ÖMPSQ-SF korkean riskin ryhmiin. Potilasopas auttoi potilaita ymmärtämään heidän kipuansa, rohkaisi heitä olemaan fyysisesti aktiivisia ja vähensi alaselän kuvantamistutkimuksia sekä sairauslomapäiviä. Vaikka luokitteluun perustuva hoitomalli ei vaikuttanut fyysiseen toimintakykyyn pitkällä aikavälillä, kipuoireet näyttivät paranevan nopeammin, terveyspalvelujen käyttö oli vähäisempää ja selkäkipuun liittyvien sairaslomapäivien määrä oli pienempi interventioryhmässä.
Yhdessä terveydenhuollon ammattilaisten koulutus, luokitteluun perustuva alaselkäkipupotilaiden hoito STarT-selkäkyselyä käyttäen ja systemaattinen potilasoppaan käyttö näytti edistävän alaselkäkipupotilaiden hoitoa perusterveydenhuollossa
Rotated twisted-mass: a convenient regularization scheme for isospin breaking QCD and QED lattice calculations
No full textWe propose a scheme of lattice twisted-mass fermion regularization which is particularly convenient for application to isospin breaking (IB) QCD and QED calculations, based in particular on the so called RM123 approach, in which the IB terms of the action are treated as a perturbation. The main, practical advantage of this scheme is that it allows the calculation of IB effects on some mesonic observables, like e.g. the pi+ - pi0 mass splitting, using lattice correlation functions in which the quark and antiquark fields in the meson are regularized with opposite values of the Wilson parameter r. These correlation functions are found to be affected by much smaller statistical fluctuations, with respect to the analogous functions in which quark and antiquark fields are regularized with the same value of r. Two numerical application of this scheme, that we call "rotated twisted-mass", within pure QCD and QCD+QED respectively, are also provided for illustration
D-meson decay constants and a check of factorization in non-leptonic B-decays
No full textWe compute the vector meson decay constants fD*((s)) from the simulation of twisted mass QeD on the lattice with N-f - 2 dynamical quarks. When combining these values with the pseudoscalar D-(s)-meson decay constants, we were able (1) to show that the heavy quark spin symmetry breaking effects with the charm quark are large. fD*(s)/fD(s) = 1.26(3), and (ii) to check the factorization approximation in a few specific B-meson non-leptonic decay modes. Besides our main results, fD* = 278 +/- 13 +/- 10 MeV, and fD*(s) = 311 +/- 9 MeV, other phenomenologically interesting results of this paper are: fD*(s)/fD* = 1.16 +/- 0.02 +/- 0.06, fD*(s)/fD - 1.46 +/- 0.05 +/- 0.06, and fD(s)/fD* - 0.89 +/- 0.02 +/- 0.03. Finally, we correct the value for B(B-0 -> D+pi(-)) quoted by PUG, and find B(B-0 -> D+pi(-)) = (7.8 +/- 1.1) x 10(-7). Alternatively, by using the ratios discussed in this paper, we obtain B(B-0 -> D+pi(-)) - (8.3 +/- 1.0 +/- 0.8) X 10(-7)
Extracting excited states from lattice QCD: the Roper resonance
No full textAbstractWe present a new method for extracting excited states from a single two-point correlation function calculated on the lattice. Our method simply combines the correlation function evaluated at different time slices so as to “subtract” the leading exponential decay (ground state) and to give access to the first excited state. The method is applied to a quenched lattice study (volume=243×64, β=6.2, a−1=2.55 GeV) of the first excited state of the nucleon using the local interpolating operator O=ɛabc[uaTCγ5db]uc. The results are consistent with the identification of our extracted excited state with the Roper resonance N′(1440). The switching of the level ordering with respect to the negative-parity partner of the nucleon, N*(1535), is not seen at the simulated quark masses and, basing on crude extrapolations, is tentatively expected to occur close to the physical point
- …
