Antiferromagnetic spin chain behavior and a transition to 3D magnetic order in Cu(D,L-alanine)2: Roles of H-bonds

We study the spin chain behavior, a transition to 3D magnetic order and the magnitudes of the exchange interactions for the metal-amino acid complex Cu(D,L-alanine)2.H2O, a model compound to investigate exchange couplings supported by chemical paths characteristic of biomolecules. Thermal and magnetic data were obtained as a function of temperature (T) and magnetic field (B0). The magnetic contribution to the specific heat, measured between 0.48 and 30 K, displays above 1.8 K a 1D spin-chain behavior that can be fitted with an intrachain antiferromagnetic (AFM) exchange coupling constant 2J0 = (-2.12 $\pm$ 0.08) cm$^{-1}$, between neighbor coppers at 4.49 {\AA} along chains connected by non-covalent and H-bonds. We also observe a narrow specific heat peak at 0.89 K indicating a phase transition to a 3D magnetically ordered phase. Magnetization curves at fixed T = 2, 4 and 7 K with B0 between 0 and 9 T, and at T between 2 and 300 K with several fixed values of B0 were globally fitted by an intrachain AFM exchange coupling constant 2J0 = (-2.27 $\pm$ 0.02) cm$^{-1}$ and g = 2.091 $\pm$ 0.005. Interchain interactions J1 between coppers in neighbor chains connected through long chemical paths with total length of 9.51 {\AA} are estimated within the range 0.1 < |2J1| < 0.4 cm$^{-1}$, covering the predictions of various approximations. We analyze the magnitudes of 2J0 and 2J1 in terms of the structure of the corresponding chemical paths. The main contribution in supporting the intrachain interaction is assigned to H-bonds while the interchain interactions are supported by paths containing H-bonds and carboxylate bridges, with the role of the H-bonds being predominant. We compare the obtained intrachain coupling with studies of compounds showing similar behavior and discuss the validity of the approximations allowing to calculate the interchain interactions.Comment: 10 pages, 4 figure

El impacto del terrorismo en el discurso político en España: un análisis de contenido de los discursos de los presidentes de Gobierno en los debates parlamentarios

This research note aims to analyze the determinants of terrorism saliency in elites' political discourse by means of a content analysis of the Spanish Presidents' speeches at the investiture sessions and the debates on the general political situation of Spain in the Spanish Parliament. Thus, it is shown the quantitative weight terrorism has had in these speeches. Apart from describing the weight of this issue, the article points out a series of hypotheses regarding changes of the saliency in these speeches and it also tries to check them provisionally. The text first states that ceasefires declared by terrorist gangs have some influence, raising the importance politicians give to this phenomenon. Second, especially relevant attacks also make terrorism grow its presence in political speeches. Third, formal agreements to exclude terrorism from party competition (such as the Ajuria-Enea Pact) have the opposite influence, for they reduce the saliency of this issue. Finally, public opinion matters: The more people consider terrorism as a problem, the more Spanish Presidents talk about it. The note tries to fill a gap in research, because the quantitative analysis of political elites' discourse about terrorism has been largely neglected. Methodologically, it combines content analysis of political texts, survey data and contextual data regarding ETA's terrorist attacks and ceasefires

Disposiciones generales reguladoras de los tributos en la Ley General Tributaria

El estudio se centra en el estudio del artículo 7 de la nueva Ley General Tributaria en las fuentes normativas, en la jerarquización de las fuentes y en las fuentes tributarias de las comunidades autónomas y de los municipios

Las figuras de economía social en la Constitución Española de 1978

The Spanish Constitution in article 129.2 establishes a mandate (and thus an imperative order) to the state powers to promote the figures and mechanisms of the social economy. This support is juxtaposed to the constitutional rules defining the Spanish economic and bs system The roots of the aforesaid support are in the Social Status established by the Constitution and in the right of all citizens to take part in economic life. However, article 129.2 of the Constitution is heterogeneous in content, making demarcation necessary. Although the rule only explicitly mentions co-operatives, work associations reunite the necessary and sufficient conditions (company organisation, voluntary access, worker decision making power within the company, the guarantee of permanent worker power) to be included in the constitutional promotion mandate. Lastly, there are two aspects of aid to social economy companies which do not allow discussion. Firstly it must facilitate subsidies for spreading and training those interested in matters relating to this type of association. Secondly, joint tax responsibility must be suppressed if a social economy company follows a capitalist company in an operative business.Constitution, promotion, social economy, social status, co-operatives, work associations, means of production.

Nutrición infantil en el Perú: un análisis empírico basado en la Encuesta Nacional de Niveles de Vida, 1994

El presente estudio pretende evaluar la relación del estado nutricional de un niño con el grado de educación de su madre. El impacto positivo de esta variable parecería evidente. La madre más educada podría recibir un mayor salario, lo cual elevaría el ingreso familiar. Además, la educación materna, en sí, permitiría un mejor aprovechamiento del potencial nutritivo de los alimentos y otros insumos de la nutrición. Sin embargo, la observación de que el cuidado de la madre constituye también uno de esos insumos sugiere la existencia de un efecto contrario. El mayor salario asociado a una mejor y, por tanto, sería más costoso para la familia que la madre se dedicase al cuidado de los niños. El presente estudio distingue cada efecto y evalúa su significancia en el caso peruano

Hacia un nuevo derecho tributario

Se describe la evolución del sistema tributario clásico, como derecho recaudatorio, hacia un nuevo derecho basado en los principios tributarios de la capacidad económica y de la generalidad tributaria, así como la aplicación de otros principios constitucionales generales: la reserva de ley, la seguridad jurídica y la tutela judicial efectiva. El autor propone, además, la necesidad de introducir un sistema más equitativo y asistencial por parte de la administración tributaria. Finalmente, sugiere el planteamiento de un nuevo Derecho tributario, donde la colaboración sea la idea clave del nuevo sistema en sustitución de la tradicional sujeción al poder tributario, así como la necesidad de alcanzar una justicia tributaria más rápida y certera

Analysis of critical moments in the league ACB 2007-08

The aim of this paper was to identify the variables that determine winning or losing in the critical moments of the basketball games. A total of forty one critical moments were analyzed, corresponding to 30 games of the regular season from the Spanish Professional League (ACB, season 2007-2008). Games were selected according to the definition of critical moments (described in the available literature), which corresponded to overtime and the last 5 minutes of games with score differences equal or below to six points. The results revealed better values in the winners in defensive rebounds and successful free-throws

Validación preliminar del inventario de hipersexualidad en jóvenes

II Jornades d’Investigació per a l’estudiantat de la Facultat de Ciències de la SalutIntroducción: La hipersexualidad es un cuadro clínico que resulta de la combinación de un deseo sexual desmedido y una incapacidad patológica para su control. Se esti- ma que podría afectar en torno al 6 % de la población, si bien la cifra varía dependien- do del instrumento empleado para su identificación. Esta varianza se debe, entre otras razones, al uso de instrumentos no validados en los contextos concretos donde se emplean. Con el objetivo de paliar esta limitación, en este trabajo se presentan los resultados psicométricos preliminares de la adaptación al castellano del inventario de hipersexualidad (de ahora en adelante, ih). Método: Para ello, 600 jóvenes (300 chi- cos y 300 chicas) de entre 18 y 27 años completaron una versión traducida y adaptada del ih junto con otros instrumentos de evaluación de compulsividad sexual. Resulta- dos: A través de afe se encontró que el ih comprendía 3 factores que explicaban el 55,5 % de la varianza del cuestionario. Esta estructura factorial se confirmó a través de afc (x2 = 239,4; g.l. = 145; x2 /g.l. = 1,65; rmsea = ,03 [90%ic = ,02 - ,04]). La fia- bilidad de la puntuación total y las subescalas osciló entre ,79 y ,91. Así mismo, las correlaciones con escalas afines resultaron positivas y significativas (r entre ,47 y ,71). Conclusión: Estos resultados justifican su empleo en la evaluación de la hipersexua- lidad en jóvenes españoles y su superioridad sobre otros instrumentos utilizados tra- dicionalmente en la evaluación clínica de esta patología.Introduction: Hypersexual disorder is a clinical diagnosis characterized by an exces- sive sexual desire together with a pathological inability to control it. It is estimated that this clinical diagnosis could be affecting about 6 % of the total population, although this figure varies depending on the instrument employed for its diagnosis. One of the most important problems when doing an accurate estimation of its prevalence is related to the use of non-validated assessment instruments. In order to solve this limitation, the preliminary results of the Spanish translation of the Hypersexuality Inventory (ih) are presented in this paper. Method: For this purpose, 600 young people (300 boys and 300 girls) between 18 and 27 years old completed a translated and adapted version of the ih together with other instruments to assess sexual compulsivity. Results: Through a factor analysis, we found that the ih was composed by 3 subscales that explained 55.5% of the variance. This factorial structure was then confirmed through confirmatory factor analyses (x2 = 239.4; g.l. = 145; x2 /g.l. = 1.65; rmsea = .03 [90%CI = .02 - .04]). Reliability for the total score and subscales ranged between .79 and .91. Moreover, correlations between the ih and related measures were positive and significant (r be- tween .74 and .71). Conclusion: These results support its employment in the assess- ment of hipersexuality among Spanish young people and its superiority to other tradi- tional measures to assess this clinical diagnosis