Partition Functions of Pure Spinors

We compute partition functions describing multiplicities and charges of massless and first massive string states of pure-spinor superstrings in 3,4,6,10 dimensions. At the massless level we find a spin-one gauge multiplet of minimal supersymmetry in d dimensions. At the first massive string level we find a massive spin-two multiplet. The result is confirmed by a direct analysis of the BRST cohomology at ghost number one. The central charges of the pure spinor systems are derived in a manifestly SO(d) covariant way confirming that the resulting string theories are critical. A critical string model with N=(2,0) supersymmetry in d=2 is also described.Comment: LaTex, 30 p

Todo lo que siempre deseó saber sobre la "cultura de prevención" y no se atrevió a preguntar

La Ley de Prevención de Riesgos Laborales plantea el fomento de una auténtica cultura preventiva. Pero esa "cultura de prevención" debería quedar inmersa en la Cultura, pues no existe una cultura específica, en este caso, que condicione la protección de la vida, la necesidad de evitar accidentes y enfermedades. Ahora bien, al transmitir la cultura, los mensajes emitidos deben estar en armonía con la interpretación que el colectivo haga de ellos, cosa que no siempre ocurre. Por tanto, no es que carezcamos de una cultura de prevención, lo que ocurre es que nuestra cultura de prevención no concuerda con la protección de la vida, con el valor "protección de la vida ", y lo verdaderamente malo del tema es que la cultura maleducada de prevención está siendo reproducida en niños y niñas, por lo que es necesario no perder la confianza en que un valor puede ser adquirido y puede pasar, con el tiempo, a proporcionar las actitudes que deseamos. ____________________________________________ The Law on Risk Prevention in the Workplace seeks to promote an authentic prevention culture. However, this "prevention culture" has to remain a part of the Culture, as there is no specific culture, in this case, that conditions human life protection and the necessity to avoid accidents and diseases. On transmitting this culture, the emitted messages must be in harmony with their interpretation. This does not always occur. Therefore, we do not lack a prevention culture. Our prevention culture is just not in accordance with the value "human life protection". This becomes really repercussive when the badly educated prevention culture is passed on to the children. Consequently, it is important not to lose faith in the possibility of acquiring this value and perhaps in the future we will see the attitudes we desire

Momentos clave en el aprendizaje de isometrías

El objetivo de este estudio es identificar ejemplos de momentos clave en el aprendizaje de isometrías de alumnos de 3o de ESO. Mostramos tres ejemplos de momentos clave y los analizamos para obtener nuevas características que ayuden a refinar la propia noción en construcción de momento clave

Geometría y tecnología

Intentaremos ilustrar algunas investigaciones sobre el papel de la tecnología en la educación geométrica, que han ido apareciendo en distintos medios de difusión profesional, con la finalidad de que los resultados de dichas investigaciones puedan convencer al profesorado que los adopte en sus clases y mejore el aprendizaje de su alumnado

Assessing measurement invariance in questionnaires within latent trait models using item response theory

Using questionnaires or inventories. researchers often perform mean comparisons between different populations (e.g .• males vs. females) in order to draw inferences about actual differences in the constructs being measured. However, such comparisons are not meaningful unless the assessments obtained in each of the populations are conmesurable or invariant across populations. Most researchers simply assume that measuremnt invariance holds. However, the extent to which this assumption is a reasonable one for specific measures and specific populations should be tested empirically. Using item response theory, the present study shows how gender measurement invariance can be determined when. as is most common, a psychological construct is assessed by means of a questionnaire or inventory composed of categorical items. To illustrate our method, the Positive Problem Orientation scale of the Social Problem-Solving Inventory-Revised (D' Zurilla. Nezu & Maydeu-Olivares, 1996) was assessed and found to be reasonably gender invariant. whereas the Negative Problem Orientation scale was not

All night analysis of time interval between snores in subjects with sleep apnea hypopnea syndrome

Sleep apnea–hypopnea syndrome (SAHS) is a serious sleep disorder, and snoring is one of its earliest and most consistent symptoms. We propose a new methodology for identifying two distinct types of snores: the so-called non-regular and regular snores. Respiratory sound signals from 34 subjects with different ranges of Apnea-Hypopnea Index (AHI = 3.7–109.9 h−1) were acquired. A total number of 74,439 snores were examined. The time interval between regular snores in short segments of the all night recordings was analyzed. Severe SAHS subjects show a shorter time interval between regular snores (p = 0.0036, AHI cp: 30 h−1) and less dispersion on the time interval features during all sleep. Conversely, lower intra-segment variability (p = 0.006, AHI cp: 30 h−1) is seen for less severe SAHS subjects. Features derived from the analysis of time interval between regular snores achieved classification accuracies of 88.2 % (with 90 % sensitivity, 75 % specificity) and 94.1 % (with 94.4 % sensitivity, 93.8 % specificity) for AHI cut-points of severity of 5 and 30 h−1, respectively. The features proved to be reliable predictors of the subjects’ SAHS severity. Our proposed method, the analysis of time interval between snores, provides promising results and puts forward a valuable aid for the early screening of subjects suspected of having SAHS