214 research outputs found
Two Classes of Cooperative Games Related to One-Object Auction Situations
AMS classifications; 91A12; 90B05;market games;ring games;one-object auction situations;big boss games;peer group games
Two Classes of Cooperative Games Related to One-Object Auction Situations
AMS classifications; 91A12; 90B05;
Iron metabolism and lymphocyte characterisation during Covid-19 infection in ICU patients: An observational cohort study
Background: Iron metabolism and immune response to SARS-CoV-2 have not been described yet in intensive care patients, although they are likely involved in Covid-19 pathogenesis. Methods: We performed an observational study during the peak of pandemic in our intensive care unit, dosing D-dimer, C-reactive protein, troponin T, lactate dehydrogenase, ferritin, serum iron, transferrin, transferrin saturation, transferrin soluble receptor, lymphocyte count and NK, CD3, CD4, CD8 and B subgroups of 31 patients during the first 2 weeks of their ICU stay. Correlation with mortality and severity at the time of admission was tested with the Spearman coefficient and Mann-Whitney test. Trends over time were tested with the Kruskal-Wallis analysis. Results: Lymphopenia is severe and constant, with a nadir on day 2 of ICU stay (median 0.555 109/L; interquartile range (IQR) 0.450 109/L); all lymphocytic subgroups are dramatically reduced in critically ill patients, while CD4/CD8 ratio remains normal. Neither ferritin nor lymphocyte count follows significant trends in ICU patients. Transferrin saturation is extremely reduced at ICU admission (median 9%; IQR 7%), then significantly increases at days 3 to 6 (median 33%, IQR 26.5%, p value 0.026). The same trend is observed with serum iron levels (median 25.5 ÎŒg/L, IQR 69 ÎŒg/L at admission; median 73 ÎŒg/L, IQR 56 ÎŒg/L on days 3 to 6) without reaching statistical significance. Hyperferritinemia is constant during intensive care stay: however, its dosage might be helpful in individuating patients developing haemophagocytic lymphohistiocytosis. D-dimer is elevated and progressively increases from admission (median 1319 ÎŒg/L; IQR 1285 ÎŒg/L) to days 3 to 6 (median 6820 ÎŒg/L; IQR 6619 ÎŒg/L), despite not reaching significant results. We describe trends of all the abovementioned parameters during ICU stay. Conclusions: The description of iron metabolism and lymphocyte count in Covid-19 patients admitted to the intensive care unit provided with this paper might allow a wider understanding of SARS-CoV-2 pathophysiology
Low-Loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths
We experimentally demonstrate a low-loss multilayered metamaterial exhibiting a double-negative refractive index in the visible spectral range. To this end, we exploit a second-order magnetic resonance of the so-called fishnet structure. The low-loss nature of the employed magnetic resonance, together with the effect of the interacting adjacent layers, results in a figure of merit as high as 3.34. A wide spectral range of negative index is achieved, covering the wavelength region between 620 and 806 nm with only two different designs. © 2011 American Physical Society.Financial support by the Spanish MICINN (Contracts No. CSD2008-00066 and No. TEC2008-06871-C02) and by the Valencian government (Contract No. PROMETEO-2010-087) is acknowledged. C.G.-M. acknowledges financial support from Grant FPU of MICINN. W.D. and A.Z. acknowledge financial support from EPSRC (U.K.).GarcĂa Meca, C.; Hurtado Montañés, J.; MartĂ Sendra, J.; MartĂnez Abietar, AJ.; Dickson, W.; Zayats, AV. (2011). Low-Loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths. Physical Review Letters. 106(6). https://doi.org/10.1103/PhysRevLett.106.067402S1066Veselago, V. G. (1968). THE ELECTRODYNAMICS OF SUBSTANCES WITH SIMULTANEOUSLY NEGATIVE VALUES OF AND ÎŒ. Soviet Physics Uspekhi, 10(4), 509-514. doi:10.1070/pu1968v010n04abeh003699Shelby, R. A. (2001). Experimental Verification of a Negative Index of Refraction. Science, 292(5514), 77-79. doi:10.1126/science.1058847Pendry, J. B. (2000). Negative Refraction Makes a Perfect Lens. Physical Review Letters, 85(18), 3966-3969. doi:10.1103/physrevlett.85.3966Tsakmakidis, K. L., Boardman, A. D., & Hess, O. (2007). âTrapped rainbowâ storage of light in metamaterials. Nature, 450(7168), 397-401. doi:10.1038/nature06285Soukoulis, C. M., Linden, S., & Wegener, M. (2007). PHYSICS: Negative Refractive Index at Optical Wavelengths. Science, 315(5808), 47-49. doi:10.1126/science.1136481Depine, R. A., & Lakhtakia, A. (2004). A new condition to identify isotropic dielectric-magnetic materials displaying negative phase velocity. Microwave and Optical Technology Letters, 41(4), 315-316. doi:10.1002/mop.20127Dolling, G., Wegener, M., Soukoulis, C. M., & Linden, S. (2006). Negative-index metamaterial at 780 nm wavelength. Optics Letters, 32(1), 53. doi:10.1364/ol.32.000053Chettiar, U. K., Kildishev, A. V., Yuan, H.-K., Cai, W., Xiao, S., Drachev, V. P., & Shalaev, V. M. (2007). Dual-band negative index metamaterial: double negative at 813 nm and single negative at 772 nm. Optics Letters, 32(12), 1671. doi:10.1364/ol.32.001671Xiao, S., Chettiar, U. K., Kildishev, A. V., Drachev, V. P., & Shalaev, V. M. (2009). Yellow-light negative-index metamaterials. Optics Letters, 34(22), 3478. doi:10.1364/ol.34.003478Mary, A., Rodrigo, S. G., Garcia-Vidal, F. J., & Martin-Moreno, L. (2008). Theory of Negative-Refractive-Index Response of Double-Fishnet Structures. Physical Review Letters, 101(10). doi:10.1103/physrevlett.101.103902GarcĂa-Meca, C., Ortuño, R., RodrĂguez-Fortuño, F. J., MartĂ, J., & MartĂnez, A. (2009). Negative refractive index metamaterials aided by extraordinary optical transmission. Optics Express, 17(8), 6026. doi:10.1364/oe.17.006026Ortuño, R., GarcĂa-Meca, C., RodrĂguez-Fortuño, F. J., MartĂ, J., & MartĂnez, A. (2009). Role of surface plasmon polaritons on optical transmission through double layer metallic hole arrays. Physical Review B, 79(7). doi:10.1103/physrevb.79.075425Zayats, A. V., Smolyaninov, I. I., & Maradudin, A. A. (2005). Nano-optics of surface plasmon polaritons. Physics Reports, 408(3-4), 131-314. doi:10.1016/j.physrep.2004.11.001Dickson, W., Wurtz, G. A., Evans, P. R., Pollard, R. J., & Zayats, A. V. (2008). Electronically Controlled Surface Plasmon Dispersion and Optical Transmission through Metallic Hole Arrays Using Liquid Crystal. Nano Letters, 8(1), 281-286. doi:10.1021/nl072613gMinovich, A., Neshev, D. N., Powell, D. A., Shadrivov, I. V., Lapine, M., McKerracher, I., ⊠Kivshar, Y. S. (2010). Tilted response of fishnet metamaterials at near-infrared optical wavelengths. Physical Review B, 81(11). doi:10.1103/physrevb.81.115109GarcĂa-Meca, C., Ortuño, R., RodrĂguez-Fortuño, F. J., MartĂ, J., & MartĂnez, A. (2009). Double-negative polarization-independent fishnet metamaterial in the visible spectrum. Optics Letters, 34(10), 1603. doi:10.1364/ol.34.001603Zhou, J., Koschny, T., & Soukoulis, C. M. (2008). An efficient way to reduce losses of left-handed metamaterials. Optics Express, 16(15), 11147. doi:10.1364/oe.16.011147Zhang, S., Fan, W., Panoiu, N. C., Malloy, K. J., Osgood, R. M., & Brueck, S. R. (2006). Optical negative-index bulk metamaterials consisting of 2D perforated metal-dielectric stacks. Optics Express, 14(15), 6778. doi:10.1364/oe.14.006778Valentine, J., Zhang, S., Zentgraf, T., Ulin-Avila, E., Genov, D. A., Bartal, G., & Zhang, X. (2008). Three-dimensional optical metamaterial with a negative refractive index. Nature, 455(7211), 376-379. doi:10.1038/nature07247Drachev, V. P., Chettiar, U. K., Kildishev, A. V., Yuan, H.-K., Cai, W., & Shalaev, V. M. (2008). The Ag dielectric function in plasmonic metamaterials. Optics Express, 16(2), 1186. doi:10.1364/oe.16.001186Kriegler, C. E., Rill, M. S., Linden, S., & Wegener, M. (2010). Bianisotropic Photonic Metamaterials. IEEE Journal of Selected Topics in Quantum Electronics, 16(2), 367-375. doi:10.1109/jstqe.2009.2020809Rockstuhl, C., Paul, T., Lederer, F., Pertsch, T., Zentgraf, T., Meyrath, T. P., & Giessen, H. (2008). Transition from thin-film to bulk properties of metamaterials. Physical Review B, 77(3). doi:10.1103/physrevb.77.035126Xiao, S., Drachev, V. P., Kildishev, A. V., Ni, X., Chettiar, U. K., Yuan, H.-K., & Shalaev, V. M. (2010). Loss-free and active optical negative-index metamaterials. Nature, 466(7307), 735-738. doi:10.1038/nature0927
Detecting new physics contributions to the D0-D0bar mixing through their effects on B decays
New physics effects may yield a detectable mass difference in the D0-D0bar
system, Delta m_D. Here we show that this has an important impact on some B -->
D decays. The effect involves a new source of CP violation, which arises from
the interference between the phases in the B --> D decays and those in the
D0-D0bar system. This interference is naturally large. New physics may well
manifest itself through Delta m_D contributions to these B decays.Comment: 10 pages, Revtex, no figures. To appear in PR
Impact of Neuromyelitis Optica Spectrum Disorder on Quality of Life from the Patients' Perspective : An Observational Cross-Sectional Study
Altres ajuts: Medical Department of Roche Farma, Spain (ML41397).Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is associated with a reduced health-related quality of life (HRQoL). The purpose of this study was to describe the impact of NMOSD on HRQoL from the patients' perspective and its relationship with other disease factors. Methods: An observational, cross-sectional study was conducted at 13 neuroimmunology clinics in Spain. Patients with NMOSD diagnosis (2015 Wingerchuk criteria) were included. The 29-item Multiple Sclerosis Impact Scale (MSIS-29) was used to assess the HRQoL. Different questionnaires were used to measure symptom severity, stigma, mood disorders, pain, fatigue, and difficulties in the workplace. Factors that impact HRQoL were identified by Spearman's correlation and multivariate linear regression analysis. Results: Seventy-one patients were included (mean age 47.4 ± 14.9 years, 80.3% female, mean time since disease onset 9.9 ± 8.1 years). The median Expanded Disability Status Scale score was 3.0 (1.5-4.5). The mean (± SD) physical and psychological MSIS-29 sub-scores were 41.9 ± 16.8 and 20.9 ± 8.3, respectively. Fatigue and body pain were the most prevalent symptoms. Depressive symptoms were found in 44.3% (n = 31) of patients. The physical MSIS-29 dimension showed the highest correlation with symptom severity (Ï = 0.85584, p < 0.0001), whereas the highest correlations for psychological MSIS-29 dimension were pain, MSIS-29 physical dimension, and depression (Ï = 0.76487, 0.72779, 0.71380; p < 0.0001, respectively). Pain was a predictor of both dimensions of MSIS-29. Conclusion: Fatigue, pain, and depressive symptoms are frequent problems among patients with NMOSD, impacting on their quality of life. Assessment of patient-oriented outcomes may be useful to achieve a holistic approach, allowing early specific interventions
Conformal mechanics inspired by extremal black holes in d=4
A canonical transformation which relates the model of a massive relativistic
particle moving near the horizon of an extremal black hole in four dimensions
and the conventional conformal mechanics is constructed in two different ways.
The first approach makes use of the action-angle variables in the angular
sector. The second scheme relies upon integrability of the system in the sense
of Liouville.Comment: V2: presentation improved, new material and references added; the
version to appear in JHE
Past Achievements and Future Challenges in 3D Photonic Metamaterials
Photonic metamaterials are man-made structures composed of tailored micro- or
nanostructured metallo-dielectric sub-wavelength building blocks that are
densely packed into an effective material. This deceptively simple, yet
powerful, truly revolutionary concept allows for achieving novel, unusual, and
sometimes even unheard-of optical properties, such as magnetism at optical
frequencies, negative refractive indices, large positive refractive indices,
zero reflection via impedance matching, perfect absorption, giant circular
dichroism, or enhanced nonlinear optical properties. Possible applications of
metamaterials comprise ultrahigh-resolution imaging systems, compact
polarization optics, and cloaking devices. This review describes the
experimental progress recently made fabricating three-dimensional metamaterial
structures and discusses some remaining future challenges
Baseline Inflammatory Status Reveals Dichotomic Immune Mechanisms Involved In Primary-Progressive Multiple Sclerosis Pathology
To ascertain the role of inflammation in the response to ocrelizumab in primary-progressive multiple sclerosis (PPMS).Multicenter prospective study including 69 patients with PPMS who initiated ocrelizumab treatment, classified according to baseline presence [Gd+, n=16] or absence [Gd-, n=53] of gadolinium-enhancing lesions in brain MRI. Ten Gd+ (62.5%) and 41 Gd- patients (77.4%) showed non-evidence of disease activity (NEDA) defined as no disability progression or new MRI lesions after 1 year of treatment. Blood immune cell subsets were characterized by flow cytometry, serum immunoglobulins by nephelometry, and serum neurofilament light-chains (sNfL) by SIMOA. Statistical analyses were corrected with the Bonferroni formula.More than 60% of patients reached NEDA after a year of treatment, regardless of their baseline characteristics. In Gd+ patients, it associated with a low repopulation rate of inflammatory B cells accompanied by a reduction of sNfL values 6 months after their first ocrelizumab dose. Patients in Gd- group also had low B cell numbers and sNfL values 6 months after initiating treatment, independent of their treatment response. In these patients, NEDA status was associated with a tolerogenic remodeling of the T and innate immune cell compartments, and with a clear increase of serum IgA levels.Baseline inflammation influences which immunological pathways predominate in patients with PPMS. Inflammatory B cells played a pivotal role in the Gd+ group and inflammatory T and innate immune cells in Gd- patients. B cell depletion can modulate both mechanisms.Copyright © 2022 FernĂĄndez-Velasco, Monreal, Kuhle, Meca-Lallana, Meca-Lallana, Izquierdo, Oreja-Guevara, GascĂłn-GimĂ©nez, Sainz de la Maza, Walo-Delgado, Lapuente-Suanzes, Maceski, RodrĂguez-MartĂn, RoldĂĄn, Villarrubia, Saiz, Blanco, Diaz-PĂ©rez, Valero-LĂłpez, Diaz-Diaz, Aladro, Brieva, Ăñiguez, GonzĂĄlez-SuĂĄrez, RodrĂguez de Antonio, GarcĂa-DomĂnguez, Sabin, Llufriu, Masjuan, Costa-Frossard and Villar
Emergence of qualia from brain activity or from an interaction of proto-consciousness with the brain: which one is the weirder? Available evidence and a research agenda
This contribution to the science of consciousness aims at comparing how two different theories can
explain the emergence of different qualia experiences, meta-awareness, meta-cognition, the placebo
effect, out-of-body experiences, cognitive therapy and meditation-induced brain changes, etc.
The first theory postulates that qualia experiences derive from specific neural patterns, the second
one, that qualia experiences derive from the interaction of a proto-consciousness with the brain\u2019s
neural activity. From this comparison it will be possible to judge which one seems to better explain
the different qualia experiences and to offer a more promising research agenda
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