Thermal hadron production in high energy collisions

It is shown that hadron abundances in high energy e+e-, pp and p{\bar p} collisions, calculated by assuming that particles originate in hadron gas fireballs at thermal and partial chemical equilibrium, are in very good agreement with the data. The freeze-out temperature of the hadron gas fireballs turns out to be nearly constant over a large center of mass energy range and not dependent on the initial colliding system. The only deviation from chemical equilibrium resides in the incomplete strangeness phase space saturation. Preliminary results of an analysis of hadron abundances in S+S and S+Ag heavy ion collisions are presented.Comment: 10 pages, 1 .eps figure, talk given at the Strangeness and Quark Matter 97 conferenc

Neutrinos from supernovae: experimental status and perspectives

I discuss the state of the art in the search for neutrinos from galactic stellar collapses and the future perspectives of this field. The implications for the neutrino physics of a high statistics supernova neutrino burst detection by the network of detectors operating around the world are also reviewed.Comment: 19 pages, 12 figures. Extended version of talk given at IInd International Workshop on Matter, Anti-Matter and Dark Matter, Trento (Italy), 29-30 October 2001. A reduced version will appear in Int. J. of Mod. Phys.

Positioning systems in Minkowski space-time: from emission to inertial coordinates

The coordinate transformation between emission coordinates and inertial coordinates in Minkowski space-time is obtained for arbitrary configurations of the emitters. It appears that a positioning system always generates two different coordinate domains, namely, the front and the back emission coordinate domains. For both domains, the corresponding covariant expression of the transformation is explicitly given in terms of the emitter world-lines. This task requires the notion of orientation of an emitter configuration. The orientation is shown to be computable from the emission coordinates for the users of a `central' region of the front emission coordinate domain. Other space-time regions associated with the emission coordinates are also outlined.Comment: 20 pages; 1 figur

Response of strawberry plants to the application of brassinosteroid under field conditions = Respuesta de plantas de frutilla a la aplicación de brasinoesteroides bajo condiciones de campo

Brassinosteroids are steroidal compounds which are required to plant growth and development and they are, also, implied in plant response to abiotic stress. Recently, important advances in the knowledge of brassinosteroids metabolism and signalling were made, both in model plants and in economically important crops. The aim of this study was to evaluate the agronomic response of strawberry plants to the application of Brassinosteroid as a biotechnological alternative for increased strawberry fruit yield at field conditions. Plants of strawberry cv. ‘Florida Festival’, were used in two annual production cycle (2014-2015) in Tucumán, Argentina. Brassinosteroid treatments increased strawberry fruit yield between 9% and 34%, mainly of marketable type fruits. No statistical difference in non- marketable fruit yield among treatments was observed.Los brasinoesteroides son compuestos esteroidales que se requieren para el crecimiento y desarrollo normal de las plantas, pero que además están implicados en la respuesta de las plantas a estrés abióticos. Recientemente fueron realizados importantes avances en el conocimiento del metabolismo y señalización de los brasinoesteroides, tanto en plantas modelos como en cultivos de importancia económica. El objetivo de este estudio fue evaluar la respuesta agronómica de plantas de frutilla a la aplicación de brasinoesteroides como una alternativa biotecnológica para aumentar el rendimiento de la fruta bajo condiciones de campo. Fueron utilizadas plantas de frutilla cv. ‘Florida Festival’, en dos ciclos anuales de producción (2014-2015) en la provincia de Tucumán, Argentina. Los tratamientos con brasinoesteroides aumentaron el rendimiento de la fruta entre 9 % y 34 %, principalmente de tipo comercial. No se observó diferencias estadísticas en frutos descarte (no comerciales) entre tratamientos.EEA FamailláFil: Salazar, Sergio Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Coll, Y. Universidad La Habana. Facultad de Química. Centro de Estudios de Productos Naturales; CubaFil: Viejobueno, Josefina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Coll, F. Universidad La Habana. Facultad de Química. Centro de Estudios de Productos Naturales; Cub

MGS accelerometer data analysis with the LMD GCM

Mars Global Surveyor aerobreaking phases, required to achieve its mapping orbit, have yielded vertical profiles of thermospheric densities, scale heights and temperatures covering a broad range of local times, seasons and spatial coordinates [Keating et al. 1998, 2001]. Phase I covered local times from 11 to 16 h (assuming 24 "martian hours” per martian day or sols), with a latitude coverage of approximately 40deg to 60deg N. Seasons observed during this phase were centered around winter solstice and altitudes of periapsis range from 115 to 135 km. The altitudes for Phase II were lower, with a minimum around 100 km and a maximum around 120. Martian spring was the season covered during this phase and the local time was between 15 and 16 h. The latitude covered by Phase II, however, was more extense than that seen during Phase I, with a coverage from 60deg N to basically the South Pole

Towards a global model of the martian atmosphere

In an effort to continuously improve the capabilities of the Martian atmospheric predictions at LMD, the GCM has been extended into thermospheric heights thus creating the first model to self-consistently couple the lower and upper regions of the Martian atmosphere. The behaviour of the Martian thermosphere is strongly influenced by lower atmospheric processes and has complex dynamics. Such a fully coupled model will certainly aid in the preparation of future missions and on the analysis of future high altitude data, as well as serve as a base for the simulation of ionospheric processes, escape, etc

Mineral oil paraffins in jute bags and cocoa butter

Jute bags and cocoa butter (CB) were analysed by gas chromatography (GC-FID/MS) to detect and quantify mineral oil saturated hydrocarbons (MOSH). Extraction clean-up on silica gel SPE (10 g/60 ml) was developed, as a unique sample preparation step for the determination of linear and branched n-alkanes in the range C14 to C31. The size of CB sample (500 mg) was sufficient for the detection of batching oil at levels of 2 mg kg−1, with satisfactory recovery and repeatability. MOSH from batching oil form a hump of unresolved components and the shape reflect balanced molecular-mass distribution between even and odd carbon atoms (from C14 to C22n-alkanes), expressed with the Carbon Preference Index (CPI=∑odd homologs/∑even homologs). Contaminated raw CB extracted from cocoa beans, transported and stored in jute bags during 2000 and 2001, showed MOSH (average 42 mg kg−1). However, only the 7.5% of the samples analysed of deodorized CB from 2007 to 2009 contained MOSH −1. High CPI values (>1.26) were attributed to natural hydrocarbons with a strong predominance of odd-numbered paraffins, situated between C22 and C31n-alkanes (average 31.7±5.37 mg kg−1). The results confirmed that MOSH components below n-C20 were fully eliminated by the deodorization process

Modeling of the general circulation with the LMD-AOPP-IAA GCM: Update on model design and comparison with observations

The LMD-AOPP GCM is developed conjointly by LMD in Paris and AOPP in Oxford, with the collaboration of IAA in Granada for the physical processes specific to the upper atmosphere. The collaboration between the two teams is based on the use of two different dynamical core (gridpoint at LMD, spectral at AOPP), which allow us to estimate the likely uncertainty arising from certain types of modeling errors. Similarly, we use different schemes to compute tracer transport, etc. The work has benefited from support from ESA (since 1995) and CNES (since 2000). Within that context, the GCMs are used to produce a Martian climate 'database' which is used by more than 30 teams around the world for mission design and scientific studies (see Bingham et al., this issue and Lewis et al., 1999). The baseline version of the GCM is described in detail in Forget et al. (1999). Here we describe the recent improvement and design changes since this publication. Compared to this previous version, the new GCM covers a wider range of altitude, from 0 to 120km in the vertical, it uses improved topography and thermal inertia surface maps from Mars Global Surveyor (MGS), and includes a new 'dust scenario' to describe the distribution of airborne dust in the atmosphere

On the degrees of freedom of a semi-Riemannian metric

A semi-Riemannian metric in a n-manifold has n(n-1)/2 degrees of freedom, i.e. as many as the number of components of a differential 2-form. We prove that any semi-Riemannian metric can be obtained as a deformation of a constant curvature metric, this deformation being parametrized by a 2-for

Effect of Anharmonic Libron Interactions on the Single-Libron Spectrum of Solid H\u3csub\u3e2\u3c/sub\u3e and D\u3csub\u3e2\u3c/sub\u3e

The effects of interactions between the elementary excitations (librons) in the orientationally ordered phase of solid H2 and D2 are studied using diagrammatic perturbation theory. This formulation leads naturally to the construction of a renormalized dynamical matrix which includes all anharmonic effects. The cubic anharmonic interactions are by far the dominant ones, and we have calculated the energy shifts of each of the zero-wave-vector libron modes self-consistently to lowest order in the expansion parameter 1/z, where z=12 is the number of nearest neighbors. We find the libron energies (in units of the electrostatic quadrupole-quadrupole coupling constant Γ) to be 11.29 (13.66), 14.07 (17.72), and 19.55 (29.04) with the corresponding harmonic values in parentheses. In contrast to the harmonic theory, these anharmonic results provide a striking fit to the observed Raman spectrum of solid H2 and D2 with reasonable values of Γ, e.g., Γ=0.59 cm−1 for H2 and Γ=0.83 cm−1 for D2. We develop an expression for the Raman intensities in terms of the single-libron spectral weight function. The group-theoretical simplifications in our calculations are discussed in detail in the appendices. The cubic anharmonicity is shown in the accompanying paper to lead to a two-libron spectrum which explains the appearance of extra high-energy lines in the Raman spectrum of solid hydrogen. These effects are shown to be included in the renormalized dynamical matrix in the present approximation. Sum rules for the Raman intensities are derived and are used to check the calculations