Precision Determination of the Top Quark Mass

The CDF and D0 collaborations have updated their measurements of the mass of the top quark using proton-antiproton collisions at sqrt{s}=1.96TeV produced at the Tevatron. The uncertainties in each of the of top-antitop decay channels have been reduced. The new Tevatron average for the mass of the top quark based on about 1/fb of data per experiment is 170.9+-1.8GeV/c^2.Comment: 14 pages, 4 figures; LaTeX2e, 8 .eps files, uses LaThuileFPSpro.sty (included). To appear in the proceedings of the 21st Rencontres des Physique de la Vallee d'Aoste, La Thuile, March 4-10, 200

Crop intensification, land use, and on-farm energy-use efficiency during the worldwide spread of the green revolution

We analyzed crop production, physical inputs, and land use at the country level to assess technological changes behind the threefold increase in global crop production from 1961 to 2014. We translated machinery, fuel, and fertilizer to embedded energy units that, when summed up, provided a measure of agricultural intensification (human subsidy per hectare) for crops in the 58 countries responsible for 95% of global production. Worldwide,there was a 137% increase in input use per hectare, reaching 13 EJ, or 2.6% of the world´s primary energy supply, versus only a 10% increase in land use. Intensification was marked in Asia and Latin America, where input-use levels reached those that North America and Europe had in the earlier years of the period; the increase was more accentuated, irrespective of continent, for the 12 countries with mostly irrigated production. Half of the countries (28/58), mainly developed ones, had an average subsidy >5 GJ/ha/y (with fertilizers accounting for 27% in 1961 and 45% in 2014), with most of them (23/28) using about the same area or less than in 1961 (net land sparing of 31 Mha). Most of the remaining countries (24/30 with inputs <5 GJ/ha/y), mainly developing ones, increased their cropped area (net land extensification of 135 Mha). Overall, energy-use efficiency (cropoutput/inputs) followed a U-shaped trajectory starting at about 3 and finishing close to 4. The prospects of a more sustainable intensification are discussed, and the inadequacy of the land-sparing model expectation of protecting wilderness via intensified agriculture is highlighted.Fil: PELLEGRINI, PEDRO. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: FERNANDEZ, Roberto J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Performance of the CDF Calorimeter Simulation in Tevatron Run II

The CDF experiment is successfully collecting data from ppbar collisions at the Tevatron in Run II. As the data samples are getting larger, systematic uncertainties due to the measurement of the jet energy scale assessed using the calorimeter simulation have become increasingly important. In many years of operation, the collaboration has gained experience with GFLASH, a fast parametrization of electromagnetic and hadronic showers used for the calorimeter simulation. We present the performance of the calorimeter simulation and report on recent improvements based on a refined in situ tuning technique. The central calorimeter response is reproduced with a precision of 1-2%.Comment: 8 pages, 4 figures; LaTeX2e, 10 .eps files, uses aipproc.cls, aipxfm.sty and aip-6s.clo (included). Contribution to the Proceedings of the 12th International Conference on Calorimetry in High Energy Physics (CALOR06), June 5-9, 2006, Chicago (IL), USA. To be published by American Institute of Physics (AIP

Multidimensional quantum cosmic models: New solutions and gravitational waves

This paper contains a discussion on the quantum cosmic models, starting with the interpretation that all of the accelerating effects in the current universe are originated from the existence of a nonzero entropy of entanglement. In such a realm, we obtain new cosmic solutions for any arbitrary number of spatial dimensions, studying the stability of these solutions, so as the emergence of gravitational waves in the realm of the most general models.Comment: 7 pages, 1 Figure, LaTe

Resolution of SU(2) monopole singularities by oxidation

We show how "colored" SU(2) BPS monopoles (that is: SU(2) monopoles satisfying the Bogomol'nyi equation whose Higgs field and magnetic charge vanish at infinity and which are singular at the origin) can be obtained from the BPST instanton by a singular dimensional reduction, explaining the origin of the singularity and implying that the singularity can be cured by the oxidation of the solution. We study the oxidation of other monopole solutions in this scheme.Comment: 13 pages, LaTeX file, no figure

Quantum phase transitions of atom-molecule Bose mixtures in a double-well potential

The ground state and spectral properties of Bose gases in double-well potentials are studied in two different scenarios: i) an interacting atomic Bose gas, and ii) a mixture of an atomic gas interacting with diatomic molecules. A ground state second-order quantum phase transition (QPT) is observed in both scenarios. For large attractive values of the atom-atom interaction, the ground-state is degenerate. For repulsive and small attractive interaction, the ground-state is not degenerate and is well approximated by a boson coherent state. Both systems depict an excited state quantum phase transition (ESQPT). For the mixed atom-molecule system the critical point of the ESQPT displays a discontinuity in the first derivative of the density of states.Comment: 25 pages, 18 figures. RevTex 4.1 (version to appear in Phys. Rev. E

Routing Protocol Performance Evaluation for Mobile Ad-hoc Networks

Currently, MANETs are a very active area of research, due to their great potential to provide networking capabilities when it is not feasible to have a fixed infrastructure in place, or to provide a complement to the existing infrastructure. Routing in this kind of network is much more challenging than in conventional networks, due to its mobile nature and limited power and hardware resources. The most practical way to conduct routing studies of MANETs is by means of simulators such as GloMoSim. GloMoSim was utilized in this research to investigate various performance statistics and draw comparisons among different MANET routing protocols, namely AODV, LAR (augmenting DSR), FSR (also known as Fisheye), WRP, and Bellman-Ford (algorithm). The network application used was FTP, and the network traffic was generated with tcplib [Danzig91]. The performance statistics investigated were application bytes received, normalized application bytes received, routing control packets transmitted, and application byte delivery ratio. The scenarios tested consisted of an airborne application at a high (26.8 m/s) and a low speed (2.7 m/s) on a 2000 m x 2000 m domain for nodal values of 36, 49, 64, 81, and 100 nodes, and radio transmit power levels of 7.005, 8.589, and 10.527 dBm. Nodes were paired up in fixed client-server couples involving 10% and 25% of the nodes being V111 clients and the same quantity being servers. AODV and LAR showed a significant margin of performance advantage over the remaining protocols in the scenarios tested

Correlation between IL1β expression level and morphological parameters proves the usefulness of morphology measures to predict the degree of activation of microglial cells

It is well known that microglial cells undergo an important change in morphology upon activation, so that form and function are intimately related. Upon activation, microglia cell body enlarges, its ramifications shortens and become thicker. In parallel, a variety of cytokines and inflammatory mediators such as IL1β are released. However the activation process is not all-or-nothing. Rather, cells in subtle activation states or in a deactivation process can occur, so intermediate not obvious phenotypes may appear. Thus, we aimed to correlate the expression level of a well-defined marker of activation, IL1β, with different morphological parameters. To do so, we used an intracerebroventricular injection of neuraminidase to produce an acute inflammation in rats. Brain sections were double-stained with IBA1 to have an image of the whole cell and its ramifications, and with IL1β to assess the level of activation. Images were captured from septofimbria (close to the injection site) and from the hypothalamus. A ratio of IL1β-positive pixels to IBA1-positive pixels was used to estimate the level of IL1β expression for each cell. Single microglial cell images were processed with ImageJ software to obtain outlined and filled shapes, which were used to obtain (by means of FracLac plug in) the following morphological parameters: fractal dimension, lacunarity, area, density and perimeter. All parameters showed a significant correlation with the level of expression of IL1β. This occurred in cells sampled from the two brain areas studied. Density, lacunarity and perimeter resulted as the best predictor parameters of activation, that is, those with a better correlation with the level of expression of IL1β. Area, an extensively used parameter to assess microglial activation, presented the least significant correlation. Thus, objectively measured morphological parameters correlate with the level of expression of IL1β, and could therefore be used as predictors of the activation level of microglial cells.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Data acquisition system for volcano monitoring with real-time transmission, low cost and low power consumption

Postprint (published version