Multivector Field Formulation of Hamiltonian Field Theories: Equations and Symmetries

We state the intrinsic form of the Hamiltonian equations of first-order Classical Field theories in three equivalent geometrical ways: using multivector fields, jet fields and connections. Thus, these equations are given in a form similar to that in which the Hamiltonian equations of mechanics are usually given. Then, using multivector fields, we study several aspects of these equations, such as the existence and non-uniqueness of solutions, and the integrability problem. In particular, these problems are analyzed for the case of Hamiltonian systems defined in a submanifold of the multimomentum bundle. Furthermore, the existence of first integrals of these Hamiltonian equations is considered, and the relation between {\sl Cartan-Noether symmetries} and {\sl general symmetries} of the system is discussed. Noether's theorem is also stated in this context, both the ``classical'' version and its generalization to include higher-order Cartan-Noether symmetries. Finally, the equivalence between the Lagrangian and Hamiltonian formalisms is also discussed.Comment: Some minor mistakes are corrected. Bibliography is updated. To be published in J. Phys. A: Mathematical and Genera

Volcano Popocatepetl, Mexico: ULF geomagnetic anomalies observed at Tlamacas station during March?July, 2005

International audienceIn this paper the first results of ULF (Ultra Low Frequency) geomagnetic anomalies observed at Tlamacas station (Long. 261.37, Lat. 19.07) located at 4 km near the volcano Popocatepetl (active volcano, Long. 261.37, Lat. 19.02) for the period March?July, 2005 and their analysis are presented. The geomagnetic data were collected with a 3-axial fluxgate magnetometer designed at UCLA (University of California, Los Angeles, 1 Hz sampling rate frequency, GPS). Our analysis reveals some anomalies which are suspected to be generated by local volcanic origin: the EM background in the vicinity of the volcano is significantly noisier than in other reference stations; the sporadic strong noise-like geomagnetic activity observed in the H-component; locally generated geomagnetic pulsations (without preferred polarization) are detected only at Tlamacas station

An All Sky Transmission Monitor: ASTMON

We present here the All Sky Transmission MONitor (ASTMON), designed to perform a continuous monitoring of the surface brightness of the complete night-sky in several bands. The data acquired are used to derive, in addition, a subsequent map of the multiband atmospheric extinction at any location in the sky, and a map of the cloud coverage. The instrument has been manufactured to afford extreme weather conditions, and remain operative. Designed to be fully robotic, it is ideal to be installed outdoors, as a permanent monitoring station. The preliminary results based on two of the currently operative units (at Do\~nana National Park - Huelva- and at the Calar Alto Observatory - Almer\'ia -, in Spain), are presented here. The parameters derived using ASTMON are in good agreement with previously reported ones, what illustrates the validity of the design and the accuracy of the manufacturing. The information provided by this instrument will be presented in forthcoming articles, once we have accumulated a statistically amount of data.Comment: 12 Figures, Accepted for publishing in PAS

Geomagnetic anomalies observed at volcano Popocatepetl, Mexico

International audienceResults of the ULF geomagnetic monitoring of the volcano Popocatepetl (Mexico) and their analysis are summarized and presented for the period 2003?2006. Our analysis reveals some anomalies which are considered to be of local volcanic origin: the EM background in the vicinity of the volcano was found to be significantly noisier than at other reference stations; sporadic strong noise-like geomagnetic activity was observed in the H-component; some geomagnetic pulsations were observed only at the Tlamacas station (located at 4 km near the volcano). The results are discussed in terms of a physical mechanism involving the presence of a second magmatic chamber within the volcano and, finally, further perspective directions to study volcanic geodynamical processes besides the traditional ones are given

Scaf1 promotes respiratory supercomplexes and metabolic efficiency in zebrafish

The oxidative phosphorylation (OXPHOS) system is a dynamic system in which the respiratory complexes coexist with superassembled quaternary structures called supercomplexes (SCs). The physiological role of SCs is still disputed. Here, we used zebrafish to study the relevance of respiratory SCs. We combined immunodetection analysis and deep data-independent proteomics to characterize these structures and found similar SCs to those described in mice, as well as novel SCs including III2 + IV2, I + IV, and I + III2 + IV2. To study the physiological role of SCs, we generated two null allele zebrafish lines for supercomplex assembly factor 1 (scaf1). scaf1 / fish displayed altered OXPHOS activity due to the disrupted interaction of complexes III and IV. scaf1 / fish were smaller in size and showed abnormal fat deposition and decreased female fertility. These physiological phenotypes were rescued by doubling the food supply, which correlated with improved bioenergetics and alterations in the metabolic gene expression program. These results reveal that SC assembly by Scaf1 modulates OXPHOS efficiency and allows the optimization of metabolic resources.Microscopy Imaging Center of the University of BernSpanish Ministry of Economy and Competitiveness, MINECO SAF2015-65633-RSpanish Ministry of Economy and Competitiveness, MINECO SAF2015-65633-RHuman Frontier Science Program RGP0016/2018European Research Council (ERC) 337703SNF 31003A-159721Swiss National Science Foundation (SNSF) 320030_170062MINECO BIO2015-67580-PCarlos III Institute of Health-Fondo de Investigacion Sanitaria) PRB3 IPT17/0019Fundacion La Marato TV3La Caixa Foundation HR17-00247Ministry of Economy, Industry and Competitiveness (MEIC)Pro-CNIC FoundationSevero Ochoa Center of Excellence (MEIC award) SEV-2015-050

c-axis penetration depth in Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} single crystals measured by ac-susceptibility and cavity perturbation technique

The $c$-axis penetration depth $\Delta\lambda_c$ in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (BSCCO) single crystals as a function of temperature has been determined using two techniques, namely, measurements of the ac-susceptibility at a frequency of 100 kHz and the surface impedance at 9.4 GHz. Both techniques yield an almost linear function $\Delta\lambda_c(T)\propto T$ in the temperature range T<0.5 T_c. Electrodynamic analysis of the impedance anisotropy has allowed us to estimate $\lambda_c(0)\approx 50 \mu$m in BSCCO crystals overdoped with oxygen ($T_c\approx 84$ K) and $\lambda_c(0)\approx 150 \mu$m at the optimal doping level ($T_c\approx 90$ K).Comment: 5 pages, 4 figure

The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars

Context. The CARMENES spectrograph is surveying ~300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims. Using spectroscopic observations, we determine the orbital and physical properties of nine new double-line spectroscopic binary systems by analysing their radial velocity curves. Methods. We use two-dimensional cross-correlation techniques to derive the radial velocities of the targets, which are then employed to determine the orbital properties. Photometric data from the literature are also analysed to search for possible eclipses and to measure stellar variability, which can yield rotation periods. Results. Out of the 342 stars selected for the CARMENES survey, 9 have been found to be double-line spectroscopic binaries, with periods ranging from 1.13 to ~8000 days and orbits with eccentricities up to 0.54. We provide empirical orbital properties and minimum masses for the sample of spectroscopic binaries. Absolute masses are also estimated from mass-luminosity calibrations, ranging between ~0.1 and ~0.6 Msol . Conclusions. These new binary systems increase the number of double-line M dwarf binary systems with known orbital parameters by 15%, and they have lower mass ratios on average.Comment: Accepted for publication in A&A. 17 pages, 4 figure

Registro de cáncer, Unidad de Oncología, Hospital Universitario Ramón González Valencia, Bucaramanga, Colombia (1996 - 1999)

ResumenLos tumores malignos est&aacute;n entre las primeras causas de mortalidad en Colombia. Se busca establecer la frecuencia, distribuci&oacute;n por g&eacute;nero y edad, histolog&iacute;a y estadio cl&iacute;nico de las neoplasias malignas valoradas en la Unidad de Oncolog&iacute;a de la ESE&ndash;HURGV durante 1996&lsquo;. Se incluyeron sujetos con edad mayor a 11 a&ntilde;os&nbsp; con diagn&oacute;stico histopatol&oacute;gico confirmado.&nbsp; pe registraron2.011 casos de c&aacute;ncer, siendo m&aacute;s frecuente en mujeres (63,5%). Un 81,8% proced&iacute;an de Santander, donde Bucaramanga aport&oacute; 515 casos (31,3%). Los diez c&aacute;nceres m&aacute;s frecuentes fueron c&eacute;rvix (17,0%), piel (14,4%), mama femenina (12,2%), est&oacute;mago (8,2%), v&iacute;as respiratorias (4,4%), pr&oacute;stata (2,7%), tiroides (2,4%), ovario y anexos (2,3%), recto (2,3%) y es&oacute;fago (2,0%). Los tiposhistol&oacute;gicos m&aacute;s frecuentes fueron: para c&eacute;rvix, el de c&eacute;lulas escamosas (85,2%); para piel, el carcinoma basocelular (67,0%); para mama femenina, el canalicular infiltrante (78,M%); para est&oacute;mago, el adenocarcinoma tipo intestinal (32,1%); para v&iacute;as respiratorias, el adenocarcinoma (21,3%); para pr&oacute;stata, el adenocarcinoma (76,4%); para tiroides, el carcinoma papilar (43,0%); para ovarioy anexos, el cistadenocarcinoma seroso papilar (10,6%); para recto, el adenocarcinoma (57,4%); y para es&oacute;fago, el carcinoma de c&eacute;lulas escamosas queratinizante (24,4%). Las cuatro primeras patolog&iacute;as entidades prevenibles; la presencia de estadios avanzados deja ver fallas en&nbsp; las campa&ntilde;as preventivas y obliga a las Escuelas de Medicina regionales a fortalecer la educaci&oacute;n parala promoci&oacute;n y prevenci&oacute;n en c&aacute;ncer.[Mantilla A, Vesga BE, Insuasty JS. Registro de c&aacute;ncer, Unidad de Oncolog&iacute;a, Hospital Universitario Ram&oacute;n Gonz&aacute;lez Valencia, Bucaramanga, Colombia (1996 - 1999). MedUNAB 2006; 9:14-19]Palabras clave: Registro institucional de c&aacute;ncer, c&aacute;ncer del cuellouterino, c&aacute;ncer de piel, c&aacute;ncer de mama