Área de actividad, movimiento y organización social de Heteromys gaumeri Allen y Chapman, 1897 (Rodentia: Heteromyidae) en una Selva Mediana Subcaducifolia de Yucatán, México

The purpouse of this study was to examinate the dynamics of Home Range (HR) and the social behaviour of Heteromy sgaumeri in the  semidesiduos tropical forest of the south of Yucatan. We used the mark-and-release technique during four nights per month, from January 2000 to December 2001. Thirty four percent (n=174) of the total population was resident being 49% males and 51% females. The females had longer residence than the males (p<0.05). For both sexes home range (HR) and maximum distance moved (MDM) (p<0.05) were higher for adults than for yuongs, seasonality did not affect them (p>0.05). Reproductive females were territorial and had lower HR and MDM than no reproductive females (p<0.05). Males and females had similar HR (p>0.05), males did not show territoriality. The total overlapping of HR was low for both sexes and both reproductive conditions. In the rain season reproductive males had a higher overlapping percentage than that of reproductive females (p<0.05). The results suggest that H. gaumeri is a social species with a promiscuous mate system.Se documentó la dinámica del Area de Actividad (AA) y el comportamiento social de Heteromys gaumeri en una selva mediana  subcaducifolia al sur de Yucatán. Se usó el método de captura-recaptura durante cuatro noches por mes de enero de 2000 a diciembre de 2001.  El 34% (n=174) de la población total fue residente, 49% fueron machos y 51% hembras. Las hembras presentaron mayor permanencia que los machos (p<0.05). En ambos sexos las AA y las distancias máximas  recorridas (DMR) de los adultos fueron mayores que las de los  inmaduros (p<0.05) y la estacionalidad no las afectó. Las hembras  reproductivas (gestantes y postlactantes) presentaron menores AA y  DMR que las no reproductivas (p<0.05), mostrando un comportamiento territorial. La sobreposición de las AA fue baja para ambos sexos y  estados reproductivos. En lluvias los machos adultos tuvieron una  mayor sobreposición que las hembras (p<0.05). Los resultados  obtenidos sugieren que H. gaumeri es una especie social, con un  sistema de parejas promiscuo.&nbsp

Propiedades puzolánicas de desechos de la industria azucarera (primera parte)

Non altered straw and sugar cane bagasse ash (CPC, CBC) collected directly from the boilers in the sugar industry and from non-controlled burning in the open fields turned up to be a reasonably good pozzolana, which can be utilized for the manufacture of lime-pozzolana binders. This paper presents a detailed survey of this material with the aim to use it as raw material in the manufacture of binders.Las cenizas de bagazo y paja de caña de azúcar (CPC, CBC), obtenidas en forma inalterada directamente de las calderas de la fábrica de azúcar, y de la quema incontrolada en el campo, representan una interesante fuente de puzolana reactiva, con potencialidad de ser usada en la preparación de aglomerantes del tipo cal/puzolana. El trabajo que se presenta realizó una evaluación integral de estas puzolanas, con el interés de utilizarlas como materia prima en la producción de aglomerantes

Propiedades puzolánicas de desechos de la industria azucarera (segunda parte)

Results of studies conducted in lime pozzolana pastes are introduced in this paper. The pozzolana was sourced from Sugar Cane Baggasse Ash (CBC) and Sugar Cane Straw Ash (CPC). The hydration of this binder was carefully monitored by means of instrumental techniques with the aim of describing the kinetics of the reaction.Se presentan los resultados de estudios realizados en pastas fabricadas con un aglomerante del tipo calpuzolana, utilizando cenizas de paja de caña (CPC) y cenizas de bagazo de caña (CBC) como puzolanas. Se muestran los estudios que caracterizan la reacción de hidratación desarrollada en este tipo de aglomerante. La evaluación realizada, utilizando diferentes técnicas instrumentales, permitieron estudiar y comprender la cinética de la reacción

Altermagnetic lifting of Kramers spin degeneracy

Lifted Kramers spin-degeneracy has been among the central topics of condensed-matter physics since the dawn of the band theory of solids. It underpins established practical applications as well as current frontier research, ranging from magnetic-memory technology to topological quantum matter. Traditionally, lifted Kramers spin-degeneracy has been considered to originate from two possible internal symmetry-breaking mechanisms. The first one refers to time-reversal symmetry breaking by magnetization of ferromagnets, and tends to be strong due to the non-relativistic exchange-coupling origin. The second mechanism applies to crystals with broken inversion symmetry, and tends to be comparatively weaker as it originates from the relativistic spin-orbit coupling. A recent theory work based on spin-symmetry classification has identified an unconventional magnetic phase, dubbed altermagnetic, that allows for lifting the Kramers spin degeneracy without net magnetization and inversion-symmetry breaking. Here we provide the confirmation using photoemission spectroscopy and ab initio calculations. We identify two distinct unconventional mechanisms of lifted Kramers spin degeneracy generated by the altermagnetic phase of centrosymmetric MnTe with vanishing net magnetization. Our observation of the altermagnetic lifting of the Kramers spin degeneracy can have broad consequences in magnetism. It motivates exploration and exploitation of the unconventional nature of this magnetic phase in an extended family of materials, ranging from insulators and semiconductors to metals and superconductors, that have been either identified recently or perceived for many decades as conventional antiferromagnets

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector