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Author Arrechea, J.; Delhom, A.; Jimenez-Cano, A. url  doi
openurl 
  Title Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity Type Journal Article
  Year 2021 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C  
  Volume (down) 45 Issue 1 Pages 013107 - 8pp  
  Keywords alternative theories of gravity; singularities; Einstein-Gauss-Bonnet  
  Abstract We attempt to clarify several aspects concerning the recently presented four-dimensional Einstein-Gauss-Bonnet gravity. We argue that the limiting procedure outlined in [Phys. Rev. Lett. 124, 081301 (2020)] generally involves ill-defined terms in the four dimensional field equations. Potential ways to circumvent this issue are discussed, alongside remarks regarding specific solutions of the theory. We prove that, although linear perturbations are well behaved around maximally symmetric backgrounds, the equations for second-order perturbations are ill-defined even around a Minkowskian background. Additionally, we perform a detailed analysis of the spherically symmetric solutions and find that the central curvature singularity can be reached within a finite proper time.  
  Address [Arrechea, Julio] CSIC, Inst Astrofis Andalucia, Granada, Spain, Email: arrechea@iaa.es;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1674-1137 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000606026400001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4676  
Permanent link to this record
 

 
Author Albiol, A.; Corbi, A.; Albiol, F. doi  openurl
  Title Automatic intensity windowing of mammographic images based on a perceptual metric Type Journal Article
  Year 2017 Publication Medical Physics Abbreviated Journal Med. Phys.  
  Volume (down) 44 Issue 4 Pages 1369-1378  
  Keywords contrast stretching; Gabor filtering; human visual system; mammogram; mutual information; window level/width  
  Abstract Purpose: Initial auto-adjustment of the window level WL and width WW applied to mammographic images. The proposed intensity windowing (IW) method is based on the maximization of the mutual information (MI) between a perceptual decomposition of the original 12-bit sources and their screen displayed 8-bit version. Besides zoom, color inversion and panning operations, IW is the most commonly performed task in daily screening and has a direct impact on diagnosis and the time involved in the process. Methods: The authors present a human visual system and perception-based algorithm named GRAIL (Gabor-relying adjustment of image levels). GRAIL initially measures a mammogram's quality based on the MI between the original instance and its Gabor-filtered derivations. From this point on, the algorithm performs an automatic intensity windowing process that outputs the WL/WW that best displays each mammogram for screening. GRAIL starts with the default, high contrast, wide dynamic range 12-bit data, and then maximizes the graphical information presented in ordinary 8-bit displays. Tests have been carried out with several mammogram databases. They comprise correlations and an ANOVA analysis with the manual IW levels established by a group of radiologists. A complete MATLAB implementation of GRAIL is available at . Results: Auto-leveled images show superior quality both perceptually and objectively compared to their full intensity range and compared to the application of other common methods like global contrast stretching (GCS). The correlations between the human determined intensity values and the ones estimated by our method surpass that of GCS. The ANOVA analysis with the upper intensity thresholds also reveals a similar outcome. GRAIL has also proven to specially perform better with images that contain micro-calcifications and/or foreign X-ray-opaque elements and with healthy BI-RADS A-type mammograms. It can also speed up the initial screening time by a mean of 4.5 s per image. Conclusions: A novel methodology is introduced that enables a quality-driven balancing of the WL/WW of mammographic images. This correction seeks the representation that maximizes the amount of graphical information contained in each image. The presented technique can contribute to the diagnosis and the overall efficiency of the breast screening session by suggesting, at the beginning, an optimal and customized windowing setting for each mammogram.  
  Address [Albiol, Alberto] Univ Politecn Valencia, iTeam Res Inst, Valencia, Spain, Email: alberto.corbi@ific.uv.es  
  Corporate Author Thesis  
  Publisher Wiley Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-2405 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000400572700016 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 3122  
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Author Rubio, B.; Gelletly, W.; Algora, A.; Nacher, E.; Tain, J.L. doi  openurl
  Title Beta decay studies with total absorption spectroscopy and the Lucrecia spectrometer at ISOLDE Type Journal Article
  Year 2017 Publication Journal of Physics G Abbreviated Journal J. Phys. G  
  Volume (down) 44 Issue 8 Pages 084004 - 25pp  
  Keywords beta decay; strength functions; total absorption gamma spectroscopy; nuclear shapes  
  Abstract Here we present the experimental activities carried out at ISOLDE with the total absorption spectrometer Lucrecia, a large 4 pi scintillator detector designed to absorb a full gamma cascade following beta decay. This spectrometer is designed to measure beta-feeding to excited states without the systematic error called Pandemonium. The set up allows the measurement of decays of very short half life. Experimental results from several campaigns, that focus on the determination of the shapes of beta-decaying nuclei by measuring their beta decay strength distributions as a function of excitation energy in the daughter nucleus, are presented.  
  Address [Rubio, B.; Gelletly, W.; Algora, A.; Tain, J. L.] Univ Valencia, CSIC, IFIC, E-46980 Paterna, Spain, Email: berta.rubio@ific.uv.es  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0954-3899 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404730700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3192  
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Author Ma, Y.Z.; Vijande, J.; Ballester, F.; Tedgren, A.C.; Granero, D.; Haworth, A.; Mourtada, F.; Fonseca, G.P.; Zourari, K.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; Sloboda, R.S.; Smith, R.; Chamberland, M.J.P.; Thomson, R.M.; Verhaegen, F.; Beaulieu, L. doi  openurl
  Title A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate Ir-192 brachytherapy Type Journal Article
  Year 2017 Publication Medical Physics Abbreviated Journal Med. Phys.  
  Volume (down) 44 Issue 11 Pages 5961-5976  
  Keywords Ir-192; HDR brachytherapy; model based dose calculation; Monte Carlo methods; shielded applicator; TG-186  
  Abstract PurposeA joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and comparisons with model-based dose calculation algorithms (MBDCAs). Its main goal is to facilitate a smooth transition from the AAPM Task Group No. 43 (TG-43) dose calculation formalism, widely being used in clinical practice for brachytherapy, to the one proposed by Task Group No. 186 (TG-186) for MBDCAs. To do so, in this work a hypothetical, generic high-dose rate (HDR) Ir-192 shielded applicator has been designed and benchmarked. MethodsA generic HDR Ir-192 shielded applicator was designed based on three commercially available gynecological applicators as well as a virtual cubic water phantom that can be imported into any DICOM-RT compatible treatment planning system (TPS). The absorbed dose distribution around the applicator with the TG-186 Ir-192 source located at one dwell position at its center was computed using two commercial TPSs incorporating MBDCAs (Oncentra((R)) Brachy with Advanced Collapsed-cone Engine, ACE, and BrachyVision ACUROS) and state-of-the-art Monte Carlo (MC) codes, including ALGEBRA, BrachyDose, egs_brachy, Geant4, MCNP6, and Penelope2008. TPS-based volumetric dose distributions for the previously reported source centered in water and source displaced test cases, and the new source centered in applicator test case, were analyzed here using the MCNP6 dose distribution as a reference. Volumetric dose comparisons of TPS results against results for the other MC codes were also performed. Distributions of local and global dose difference ratios are reported. ResultsThe local dose differences among MC codes are comparable to the statistical uncertainties of the reference datasets for the source centered in water and source displaced test cases and for the clinically relevant part of the unshielded volume in the source centered in applicator case. Larger local differences appear in the shielded volume or at large distances. Considering clinically relevant regions, global dose differences are smaller than the local ones. The most disadvantageous case for the MBDCAs is the one including the shielded applicator. In this case, ACUROS agrees with MC within [-4.2%, +4.2%] for the majority of voxels (95%) while presenting dose differences within [-0.12%, +0.12%] of the dose at a clinically relevant reference point. For ACE, 95% of the total volume presents differences with respect to MC in the range [-1.7%, +0.4%] of the dose at the reference point. ConclusionsThe combination of the generic source and generic shielded applicator, together with the previously developed test cases and reference datasets (available in the Brachytherapy Source Registry), lay a solid foundation in supporting uniform commissioning procedures and direct comparisons among treatment planning systems for HDR Ir-192 brachytherapy.  
  Address [Ma, Yunzhi; Beaulieu, Luc] CHU Quebec, Dept Radio Oncol & Axe Oncol, Ctr Rech, Quebec City, PQ G1R 2J6, Canada, Email: yunzhi.Ma@crchuq.ulaval.ca  
  Corporate Author Thesis  
  Publisher Wiley Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-2405 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000414970800039 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3370  
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Author Cui, Z.F.; Zhang, J.L.; Binosi, D.; De Soto, F.; Mezrag, C.; Papavassiliou, J.; Roberts, C.D.; Rodriguez-Quintero, J.; Segovia, J.; Zafeiropoulos, S. url  doi
openurl 
  Title Effective charge from lattice QCD Type Journal Article
  Year 2020 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C  
  Volume (down) 44 Issue 8 Pages 083102 - 10pp  
  Keywords running coupling; quantum chromodynamics; Dyson-Schwinger equations; lattice field theory; emergence of mass; confinement  
  Abstract Using lattice configurations for quantum chromodynamics (QCD) generated with three domain-wall fermions at a physical pion mass, we obtain a parameter-free prediction of QCD 's renormalisation-group-invariant process-independent effective charge, (alpha) over cap (k(2)). Owing to the dynamical breaking of scale invariance, evident in the emergence of a gluon mass-scale, m(0) = 0.43(1) GeV, this coupling saturates at infrared momenta: (alpha) over cap/pi = 0.97(4). Amongst other things: (alpha) over cap (k(2)) is almost identical to the process-dependent (PD) effective charge defined via the Bjorken sum rule; and also that PD charge which, employed in the one-loop evolution equations, delivers agreement between pion parton distribution functions computed at the hadronic scale and experiment. The diversity of unifying roles played by (alpha) over cap (k(2)) suggests that it is a strong candidate for that object which represents the interaction strength in QCD at any given momentum scale; and its properties support a conclusion that QCD is a mathematically well-defined quantum field theory in four dimensions.  
  Address [Cui, Z-F; Roberts, C. D.] Nanjing Univ, Sch Phys, Nanjing 210093, Peoples R China, Email: cdroberts@nju.edu.cn;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1674-1137 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000557419600001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4495  
Permanent link to this record
 

 
Author Panotopoulos, G. url  doi
openurl 
  Title A dynamical dark energy model with a given luminosity distance Type Journal Article
  Year 2011 Publication General Relativity and Gravitation Abbreviated Journal Gen. Relativ. Gravit.  
  Volume (down) 43 Issue 11 Pages 3191-3199  
  Keywords Dark energy; Observational cosmology; Particle-theory  
  Abstract It is assumed that the current cosmic acceleration is driven by a scalar field, the Lagrangian of which is a function of the kinetic term only, and that the luminosity distance is a given function of the red-shift. Upon comparison with baryon acoustic oscillations and cosmic microwave background data the parameters of the models are determined, and then the time evolution of the scalar field is determined by the dynamics using the cosmological equations. We find that the solution is very different than the corresponding solution when the non-relativistic matter is ignored, and that the universe enters the acceleration era at larger red-shift compared to the standard I > CDM model.  
  Address [Panotopoulos, G] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Spain, Email: Grigoris.Panotopoulos@uv.es  
  Corporate Author Thesis  
  Publisher Springer/Plenum Publishers Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-7701 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000295982800015 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 782  
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Author Candela-Juan, C.; Niatsetski, Y.; van der Laarse, R.; Granero, D.; Ballester, F.; Perez-Calatayud, J.; Vijande, J. doi  openurl
  Title Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions Type Journal Article
  Year 2016 Publication Medical Physics Abbreviated Journal Med. Phys.  
  Volume (down) 43 Issue 4 Pages 1639-1648  
  Keywords skin applicator; Valencia applicator; HDR brachytherapy; dosimetry; Monte Carlo  
  Abstract Purpose: The aims of this study were (i) to design a new high-dose-rate (HDR) brachytherapy applicator for treating surface lesions with planning target volumes larger than 3 cm in diameter and up to 5 cm in size, using the microSelectron-HDR or Flexitron afterloader (Elekta Brachytherapy) with a Ir-192 source; (ii) to calculate by means of the Monte Carlo (MC) method the dose distribution for the new applicator when it is placed against a water phantom; and (iii) to validate experimentally the dose distributions in water. Methods: The PENELOPE2008 MC code was used to optimize dwell positions and dwell times. Next, the dose distribution in a water phantom and the leakage dose distribution around the applicator were calculated. Finally, MC data were validated experimentally for a 192Ir mHDR-v2 source by measuring (i) dose distributions with radiochromic EBT3 films (ISP); (ii) percentage depth-dose (PDD) curve with the parallel-plate ionization chamber Advanced Markus (PTW); and (iii) absolute dose rate with EBT3 films and the PinPoint T31016 (PTW) ionization chamber. Results: The new applicator is made of tungsten alloy (Densimet) and consists of a set of interchangeable collimators. Three catheters are used to allocate the source at prefixed dwell positions with preset weights to produce a homogenous dose distribution at the typical prescription depth of 3 mm in water. The same plan is used for all available collimators. PDD, absolute dose rate per unit of air kerma strength, and off-axis profiles in a cylindrical water phantom are reported. These data can be used for treatment planning. Leakage around the applicator was also scored. The dose distributions, PDD, and absolute dose rate calculated agree within experimental uncertainties with the doses measured: differences of MC data with chamber measurements are up to 0.8% and with radiochromic films are up to 3.5%. Conclusions: The new applicator and the dosimetric data provided here will be a valuable tool in clinical practice, making treatment of large skin lesions simpler, faster, and safer. Also the dose to surrounding healthy tissues is minimal.  
  Address [Candela-Juan, C.; Perez-Calatayud, J.] La Fe Univ & Polytech Hosp, Dept Radiat Oncol, Valencia 46026, Spain, Email: ccanjuan@gmail.com  
  Corporate Author Thesis  
  Publisher Amer Assoc Physicists Medicine Amer Inst Physics Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-2405 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000373711000007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2620  
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Author Granero, D.; Candela-Juan, C.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Jacob, D.; Mourtada, F. doi  openurl
  Title Technical Note: Dosimetry of Leipzig and Valencia applicators without the plastic cap Type Journal Article
  Year 2016 Publication Medical Physics Abbreviated Journal Med. Phys.  
  Volume (down) 43 Issue 5 Pages 2087 - 4pp  
  Keywords Leipzig applicators; Valencia applicators; skin brachytherapy; Monte Carlo; dosimetry  
  Abstract Purpose: High dose rate (HDR) brachytherapy for treatment of small skin lesions using the Leipzig and Valencia applicators is a widely used technique. These applicators are equipped with an attachable plastic cap to be placed during fraction delivery to ensure electronic equilibrium and to prevent secondary electrons from reaching the skin surface. The purpose of this study is to report on the dosimetric impact of the cap being absent during HDR fraction delivery, which has not been explored previously in the literature. Methods: GEANT4 Monte Carlo simulations (version 10.0) have been performed for the Leipzig and Valencia applicators with and without the plastic cap. In order to validate the Monte Carlo simulations, experimental measurements using radiochromic films have been done. Results: Dose absorbed within 1 mm of the skin surface increases by a factor of 1500% for the Leipzig applicators and of 180% for the Valencia applicators. Deeper than 1 mm, the overdosage flattens up to a 10% increase. Conclusions: Differences of treating with or without the plastic cap are significant. Users must check always that the plastic cap is in place before any treatment in order to avoid overdosage of the skin. Prior to skin HDR fraction delivery, the timeout checklist should include verification of the cap placement. (C) 2016 American Association of Physicists in Medicine.  
  Address [Granero, D.] Hosp Gen Univ, Dept Radiat Phys, ERESA, Valencia 46014, Spain, Email: dgranero@eresa.com  
  Corporate Author Thesis  
  Publisher Amer Assoc Physicists Medicine Amer Inst Physics Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-2405 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000378924200010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2753  
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Author Ayala, C.; Gonzalez, P.; Vento, V. url  doi
openurl 
  Title Heavy quark potential from QCD-related effective coupling Type Journal Article
  Year 2016 Publication Journal of Physics G Abbreviated Journal J. Phys. G  
  Volume (down) 43 Issue 12 Pages 125002 - 12pp  
  Keywords general properties of QCD; potential models; other non-perturbative calculations; heavy quarkonia  
  Abstract We implement our past investigations of quark-antiquark interaction through a non-perturbative running coupling defined in terms of a gluon mass function, similar to that used in some Schwinger-Dyson approaches. This coupling leads to a quark-antiquark potential, which satisfies not only asymptotic freedom but also describes linear confinement correctly. From this potential, we calculate the bottomonium and charmonium spectra below the first open flavor meson-meson thresholds and show that for a small range of values of the free parameter determining the gluon mass function an excellent agreement with data is attained.  
  Address [Gonzalez, Pedro] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: Pedro.Gonzalez@uv.es  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0954-3899 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000388219700001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2870  
Permanent link to this record
 

 
Author Wang, Y.F.; Yao, D.L.; Zheng, H.Q. url  doi
openurl 
  Title New insights on low energy pi N scattering amplitudes: comprehensive analyses at O (p(3)) level Type Journal Article
  Year 2019 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C  
  Volume (down) 43 Issue 6 Pages 064110 - 22pp  
  Keywords dispersion relations; pion-nucleon scattering; chiral perturbation theory  
  Abstract A production representation of partial-wave S matrix is utilized to construct low-energy elastic pion-nucleon scattering amplitudes from cuts and poles on complex Riemann sheets. Among them, the contribution of left-hand cuts is estimated using the O (p(3)) results obtained in covariant baryon chiral perturbation theory within the extendedon-nass-shell scheme. By fitting to data on partial-wave phase shifts, it is indicated that the existences of hidden poles in S-11 and P-11 channels, as conjectured in our previous paper [Eur. Phys. J. C, 78(7): 543 (2018)], are firmly established. Specifically, the pole mass of the S-11 hidden resonance is determined to be (895 +/- 81)-(164 +/- 23)i MeV, whereas, the virtual pole in the P-11 channel locates at (966 +/- 18) MeV. It is found that analyses at the O (p(3)) level improves significantly the fit quality, comparing with the previous O (p(2)) one. Quantitative studies with cautious physical discussions are also conducted for the other S- and P-wave channels.  
  Address [Wang, Yu-Fei; Zheng, Han-Qing] Peking Univ, Dept Phys, Beijing 100871, Peoples R China, Email: yaodeliang@pku.edu.cn  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1674-1137 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000468501700013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4020  
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