Electronic structure and properties of AlN

The electronic structure of the wurtzite-type phase of aluminum nitride has been investigated by means of periodic ab initio Hartree-Fock calculations. The binding energy, lattice parameters (a,c), and the internal coordinate (u) have been calculated. All structural parameters are in excellent agreement with the experimental data. The electronic structure and bonding in AlN are analyzed by means of density-of-states projections and electron-density maps. The calculated values of the bulk modulus, its pressure derivative, the optical-phonon frequencies at the center of the Brillouin zone, and the full set of elastic constants are in good agreement with the experimental data.

Electronic structure and properties of AlN

The electronic structure of the wurtzite-type phase of aluminum nitride has been investigated by means of periodic ab initio Hartree-Fock calculations. The binding energy, lattice parameters (a,c), and the internal coordinate (u) have been calculated. All structural parameters are in excellent agreement with the experimental data. The electronic structure and bonding in AlN are analyzed by means of density-of-states projections and electron-density maps. The calculated values of the bulk modulus, its pressure derivative, the optical-phonon frequencies at the center of the Brillouin zone, and the full set of elastic constants are in good agreement with the experimental data.

Reseña de Carmen Alén Garabato / Xosé Afonso Álvarez / Mercedes Brea (dirs.) (2010): Quelle linguistique romane au XXIe siècle?. Paris: L"Harmattan, 294 p.

Con la perspectiva que se va abriendo del nuevo siglo tras el transcurso de su primera década, este volumen colectivo reúne un ramillete de contribuciones de distintos especialistas que muestran aspectos diversos de la lingüística románica, disciplina forjada en el xix y que, camino de dos centurias después, induce a los directores-coordinadores del libro en la página inicial de la Présentation a plantear las expectativas de su enseñanza futura en el marco de la ciencia y de la sociedad que vienen.

Alén Garabato, Carmen / Arnavielle, Teddy / Camps, Christian (dir.) (2009): La romanistique dans tous ses états. Paris: L'Harmattan. (Langue et parole)

En aquest volum es recullen les intervencions fetes en el col·loqui La Romanistique dans tous ses états, que tingué lloc a Béziers del 15 al 17 de maig de 2008. El col·loqui s"articulà al voltant de diverses temàtiques, que anaven des de la historiografia de la lingüística romànica fins a les propostes actuals de gestió lingüística (didàctica, protecció de llengües amenaçades), passant per altres temes; tot això, amb el denominador comú de la intenció de fer un estat de la lingüística romànica en un moment en què, si bé és cultivada en institucions diverses i en un esplet de congressos i altres trobades científiques, perd terreny en l"ensenyament universitari, on la perspectiva global i comparatista s"està abandonant.

Effect of magnesium sulphate and L-tryptophan and genotype on the feed intake, behaviour and meat quality of pigs

Sixty-nine entire male pigs with different halothane genotype (homozygous halothane positive – nn –, n=36; and homozygous halothane negative – NN-, n=33) were fed with a supplementation of magnesium sulphate (Mg) and/or L-tryptophan (Trp) in the diet for 5 days before slaughter. Animals were housed individually and were submitted to stressful ante mortem conditions (mixed in the lorry according to treatments and transported 1 hour on rough roads). Individual feed intake was recorded during the 5-d treatment. At the abattoir, pig behaviour was assessed in the raceway to the stunning system and during the stunning period by exposure to CO2. Muscle pH, colour, water holding capacity, texture and cathepsin activities were determined to assess meat quality. The number of pigs with an individual feed intake lower than 2 kg/d was significantly different among diets (P&0.05; Control: 8.7 %; Mg&Trp: 43.5 %; Trp: 17.4 %) and they were considered to have inadequate supplement intake. During the ante mortem period, 15.2 % of pigs included in the experiment died, and this percentage decreased to 8.7 % in those pigs with a feed intake & 2kg/day, all of them from the stress-sensitive pigs (nn). In general, no differences were observed in the behaviour of pigs along the corridor leading to the stunning system and inside the CO2 stunning system. During the stunning procedure, Trp diet showed shorter periods of muscular excitation than control and Mg&Trp diets. The combination of a stressful ante mortem treatment and Mg&Trp supplementation led to carcasses with high incidence of severe skin lesions. Different meat quality results were found when considering all pigs or considering only those with adequate supplement intake. In this later case, Trp increased pH45 (6.15) vs Control diet (5.96) in the Longissimus thoracis (LT) muscle (P&0.05) and pH at 24h (Trp: 5.59 vs C: 5.47) led to a higher incidence of dark, firm and exudative (DFD) traits in SM muscle (P&0.05). Genotype affected negatively all the meat quality traits. Seventy-five percent of LT and 60.0 % of the SM muscles from nn pigs were classified as pale, soft and exudative (PSE), while none of the NN pigs showed these traits (P&0.0001). No significant differences were found between genotypes on the incidence of DFD meat. Due to the negative effects observed in the Mg&Trp group in feed intake and carcass quality, the utilization of a mixture of magnesium sulphate and tryptophan is not recommended.

Relació entre el risc de patir una lesió de trànsit i les malalties del subjecte conductor, analitzades des de l’àmbit de l’Atenció Primària

INTRODUCCIÓ: Lesions per trànsit (LT), evitables i problema de salut publica. Àmbit d’atenció primària (AP) lloc on investigar i actuar. Possible relació entre malalties cròniques del conductor i LT. MÈTODES: estudi descriptiu, transversal i multicèntric, conductors amb història clínica, Barcelona, 2009. 1900 enquestes personals, mostreig consecutiu. Variables sociodemogràfiques, sobre conducció i salut. RESULTATS: 57,3% homes, 8,5% conductors professionals, 12,5% havia patit una LT, 6% va precisar ajuda mèdica. 51,5% malalts crònics, predominant malalties cardiovasculars i limitacions visuals. CONCLUSIONS: No van trobar relacions significatives entre malalties cròniques i LT. Limitacions:imperfecció dels sistemes de registre, fiabilitat feble de dades autodeclarades, presencia de possibles factors de confusió.

El consum de fàrmacs en la població conductora: un estudi poblacional des de l’Atenció Primària

INTRODUCCIÓ: Lesions per trànsit (LT), evitables i problema de salut pública. Àmbit d’atenció primària (AP), lloc on investigar i actuar. Possible relació medicació crònica del conductor i LT. MÈTODES: estudi descriptiu, transversal i multicèntric, conductors amb història clínica, província Barcelona. 1900 enquestes, mostreig consecutiu. Variables sociodemogràfiques, sobre conducció i salut. RESULTATS: 57,3% homes, 8,5% conductors professionals, 12,5% havia patit una LT, 6% va precisar ajuda mèdica. 45,2% medicació crònica, predominant tractament cardiovascular. CONCLUSIONS: No s’han trobat relacions significatives entre medicació crònica i LT. Limitacions:imperfecció dels sistemes de registre, fiabilitat feble de dades autodeclarades, presència de possibles factors de confusió.

Reduction theorems for operators on the cones of monotone functions

For a quasilinear operator on the semiaxis a reduction theorem is proved on the cones of monotone functions in Lp - Lq setting for 0 < q < ∞, 1<= p < ∞. The case 0 < p < 1 is also studied for operators with additional properties. In particular, we obtain critera for three-weight inequalities for the Hardy-type operators with Oinarov' kernel on monotone functions in the case 0 < q < p <= 1.