A topological mechanism of discretization for the electric charge

We present a topological mechanism of discretization, which gives for the fundamental electric charge a value equal to the square root of the Planck constant times the velocity of light, which is about 3.3 times the electron charge. Its basis is the following recently proved property of the standard linear classical Maxwell equations: they can be obtained by change of variables from an underlying topological theory, using two complex scalar fields, the level curves of which coincide with the magnetic and the electric lines, respectively.Comment: 10 pages, LaTeX fil

High-temperature oxidation evaluation usingcrystal microbalance

High-temperature oxidising environments are frequently encountered but the limited number of in situ techniques that can be implemented has hindered the monitoring possibilities and a better comprehension of the oxidation phenomenon. In this paper, the high-temperature oxidation behaviours of three alloys (AISI 316L, AISI 310 and HAYNES\uae HR-120\uae) were studied by using crystal microbalances. Two types of crystal were tested: quartz or gallium orthophosphate crystals. First the behaviour of thin sputtered deposited alloys on quartz slides was studied at 400 and 700\ub0C under air oxidising conditions and compared to bulk samples. Kinetics measurements were performed on the three alloy films deposited on the resonators at 400 or 700\ub0C: it was possible to measure very small mass variations associated with thin oxide formation between 5 and 180 nm of thickness. The crystal microbalance technique gives promising perspectives in understanding the high-temperature corrosion and scaling mechanisms and also for in situ monitoring

Unexpected distribution of the fluoroquinolone-resistance gene qnrB in Escherichia coli isolates from different human and poultry origins in Ecuador

Fluoroquinolone resistance can be conferred through chromosomal mutations or by the acquisition of plasmids carrying genes such as the quinolone resistance gene (qnr). In this study, 3,309 strains of commensal Escherichia coli were isolated in Ecuador from: (i) humans and chickens in a rural northern coastal area (n = 2368, 71.5%) and (ii) chickens from an industrial poultry operation (n = 827, 25%). In addition, 114 fluoroquinolone-resistant strains from patients with urinary tract infections who were treated at three urban hospitals in Quito, Ecuador were analyzed. All of the isolates were subjected to antibiotic susceptibility screening. Fluoroquinolone-resistant isolates (FRIs) were then screened for the presence of qnrB genes. A significantly higher phenotypic resistance to fluoroquinolones was determined in E. coli strains from chickens in both the rural area (22%) and the industrial operation (10%) than in strains isolated from humans in the rural communities (3%). However, the rates of qnrB genes in E. coli isolates from healthy humans in the rural communities (11 of 35 isolates, 31%) was higher than in chickens from either the industrial operations (3 of 81 isolates, 6%) or the rural communities (7 of 251 isolates, 2.8%). The occurrence of qnrB genes in human FRIs obtained from urban hospitals was low (1 of 114 isolates, 0.9%). These results suggested that the qnrB gene is more widely distributed in rural settings, where antibiotic usage is low, than in urban hospitals and industrial poultry operations. The role of qnrB in clinical resistance to fluoroquinolones is thus far unknown. [Int Microbiol 2015; 18(2):85-90]Keywords: Escherichia coli · gene qnrB · quinolone resistance · urban hospitals · industral poultry operation

Observations of field and cluster RR Lyræ with Spitzer. Towards high precision distances with Population II stellar tracers

Indexación: Scopus.We present our project to calibrate the RR Lyræ period-luminosity-metallicity relation using a sample of Galactic calibrators in the halo and globular clusters.https://www.epj-conferences.org/articles/epjconf/pdf/2017/21/epjconf_puls2017_07004.pd

High magnetic anisotropy of Fe+ ions in KTaO3 and SrCl2

The zero-field splitting constant, D, and the gyromagnetic tensor of the off-center system KTaO3:Fe+ and SrCl2:Fe+ have been explored by means of calculations based on the density-functional theory at the C4v local equilibrium geometry. The calculated D values for KTaO3:Fe+ (9?cm?1) and SrCl2:Fe+ (53 cm?1) are found to be much higher than typical figures measured for insulating compounds containing common 3d Kramers ions with a spin S>1/2 in the ground state. This result together with the calculated g? and g? values concur with available experimental information. The high magnetic anisotropy derived for Fe+ in KTaO3 and SrCl2 is shown to be strongly related to the existence of a 4E excited state lying only at about 3000 and 600?cm?1, respectively, above the ground state. Implications of present findings in the search of new molecular magnets with high values of the magnetic anisotropy are discussed in some detail.The support by the Spanish Ministerio de Ciencia y Tecnología under Projects No. FIS2006-02261 and No. FIS2009-07083 is acknowledged.The support by the Spanish Ministerio de Ciencia y Tecnología under Projects No. FIS2006-02261 and No. FIS2009-07083 is acknowledged

The Role of Mobile Genetic Elements in the Spread of Antimicrobial-Resistant Escherichia coli from Chickens to Humans in Small-Scale Production Poultry Operations in Rural Ecuador

© The Author(s) 2018. Small-scale production poultry operations are increasingly common worldwide. To investigate how these operations influence antimicrobial resistance and mobile genetic elements (MGEs), Escherichia coli isolates were sampled from small-scale production birds (raised in confined spaces with antibiotics in feed), household birds (no movement constraints; fed on scraps), and humans associated with these birds in rural Ecuador (2010-2012). Isolates were screened for genes associated with MGEs as well as phenotypic resistance to 12 antibiotics. Isolates from small-scale production birds had significantly elevated odds of resistance to 7 antibiotics and presence of MGE genes compared with household birds (adjusted odds ratio (OR) range = 2.2-87.9). Isolates from humans associated with small-scale production birds had elevated odds of carrying an integron (adjusted OR = 2.0; 95% confidence interval (CI): 1.06, 3.83) compared with humans associated with household birds, as well as resistance to sulfisoxazole (adjusted OR = 1.9; 95% CI: 1.01, 3.60) and trimethoprim/sulfamethoxazole (adjusted OR = 2.1; 95% CI: 1.13, 3.95). Stratifying by the presence of MGEs revealed antibiotic groups that are explained by biological links to MGEs; in particular, resistance to sulfisoxazole, trimethoprim/sulfamethoxazole, or tetracycline was highest among birds and humans when MGE exposures were present. Small-scale production poultry operations might select for isolates carrying MGEs, contributing to elevated levels of resistance in this setting

Humoral and cellular immunity to SARS-COV-2 after vaccination with mRNA vaccines in PLWH with discordant immune response. Influence of the vaccine administered

Background: Data on SARS-CoV-2 mRNA vaccine immunogenicity in people living with human immunodeficiency virus (PLWH) and discordant immune response (DIR) are currently limited. Therefore, we compare the immunogenicity of these vaccines in DIR and immunological responders (IR). Methods: A prospective cohort that enrolled 89 participants. Finally, 22 IR and 24 DIR were analyzed before vaccination (T), one (T) and six months (T) after receiving BNT162b2 or mRNA-1273 vaccine. Additionally, 10 IR and 16 DIR were evaluated after a third dose (T). Anti-S-RBD IgG, neutralizing antibodies (nAb), neutralization activity, and specific memory B cells were quantified. Furthermore, specific CD4 and CD8 responses were determined by intracellular cytokine staining and polyfunctionality indexes (Pindex). Results: At T, all participants developed anti-S-RBD. 100% IR developed nAb compared to 83.3% DIR. Spike-specific B cells were detected in all IR and 21/24 DIR. Memory CD4 T cells responded in 5/9 IR and 7/9 DIR, mainly based on the expression of IFN-γ and TNF-α, with a higher Pindex in DIR. Memory CD8 T cells responded in only four participants in each group. At T, anti-S-RBD and nAb titers were higher in DIR than in IR. In both groups, there was an increase in specific B memory cells, higher in DIR. Six IR and five DIR maintained a specific memory CD4 response. Memory CD8 response was preserved in IR but was lost in DIR. In a multivariate linear regression analysis, receiving mRNA-1273 instead of BNT162b2 played a prominent role in the results. Conclusions: Our data suggest that PLWH with DIR can mount an immune response similar to those with higher CD4, provided they receive the mRNA-1273 vaccine instead of others less immunogenic.In collaboration with the Gilead Biomedical Research Grants Program GLD21_00096. In addition, this work was supported by Instituto de Salud Carlos III, co-financed by the European Regional Development Fund “a way to make Europe” through the Program Miguel Servet to AG-V (CP19/00159), PFIS contract to AS-A (FI21/ 00165) and EM-M (FI19/00304) and programa Rio Hortega to MM-T (CM21/00115). Consejerı́a de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucı́a, grant P20_00906

Historical and current evolution of the coastline on the beach of Somo (Cantabria), by using aerial photogrammetry and terrestrial laser scanning

Los trabajos topográficos llevados a cabo en la playa de Somo en el periodo 1988-1993 muestran ligeros cambios en la línea de costa. Para constatar estos cambios se ha estudiado el periodo 2001-2010 mediante fotogrametría, y desde el año 2011 se realizan dos mediciones anuales con láser escáner terrestre (TLS). Para este estudio, se ha seleccionado una porción de 400 metros en la playa de Somo, por coincidir con las mediciones del periodo 1988-1993. La aplicación de instrumentación geomática (GPS, estación total, TLS) y fotogrametría aérea ha permitido establecer dos grupos de periodos con comportamientos netamente diferentes. Un grupo donde no hay casi retroceso de la línea de costa arenosa: 1988-1993, 2001-2013, y otro grupo de retroceso acentuado: 1994-2000 y 2014. Este último año coincidieron temporales de grandes olas (mayores a 5 m) y mareas vivas que provocaron retrocesos de mayor rango en la línea de costa

Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388