Magnetostriction of a Superconductor: -Results from the Critical-State Model

In many cases, the critical-state theory can be treated as a suffi ciently accurate approximation for the modelling of the magnetic properties of superconductors. In the present work, the magnetostrictive hysteresis is computed for a quite general case of the modified Kim-Anderson model. The results obtained reproduce many features of the giant magnetostriction (butterfly-shaped curves) reported in the literature for measurements made on single-crystal samples of the high-temperature superconductor $Bi_2Sr_2CaCu_2O_8$. It is shown that addition of a contribution to the magnetostriction in the superconducting state which is of similar origin as in the normal state, offers a broader phenomenological interpretation of the complex magnetostriction hysteresis found in such heavy-fermion compounds as $UPt_3$, $URu_2Si_2$ or $UBe_{13}$.Comment: 9 LaTeX pages, 4 Postscript figures, WWW version available at http://is.dal.ca/~zkoziol/super.htm

Validation of the short version of the dimensional inventory for child development assessment

Objectives: There is a critical need to monitor the development of children around the world, and in Brazil, this need is substantial since there is a paucity of assessment tools. This study aimed to describe the design and provide evidence of reliability and validity for the short version of the Dimensional Inventory for Child Development Assessment (IDADI-short). Methods: A sample of 1,865 biological mothers of children aged 4---72 months (M = 34.8, SD = 20.20) completed the IDADI to assess Cognitive, socio-emotional, Expressive, and Receptive Language and Communication, Fine and Gross Motor, and Adaptive Behavior development. The psychometric properties of a total of 118 subscales of IDADI were obtained and the IDADI-short age-specific scores were correlated with the original inventory, and criteria variables such as neurodevelopment diagnosis, socioeconomic status, and sex. Results: Item Response Theory analysis, Cronbach’s Alpha, and McDonald’s Omega indicated excellent internal consistency and optimal participant discrimination after minor alterations. IDADI-short scores were strongly associated with the original inventory, with high sensibility and specificity precision for developmental delays. Significant associations with relevant criteria variables were also observed. Conclusion: Findings support the use of IDADI-short as a parental measure of young children’s development

Validation of the short version of the dimensional inventory for child development assessment

Objectives: There is a critical need to monitor the development of children around the world, and in Brazil, this need is substantial since there is a paucity of assessment tools. This study aimed to describe the design and provide evidence of reliability and validity for the short version of the Dimensional Inventory for Child Development Assessment (IDADI-short). Methods: A sample of 1,865 biological mothers of children aged 4---72 months (M = 34.8, SD = 20.20) completed the IDADI to assess Cognitive, socio-emotional, Expressive, and Receptive Language and Communication, Fine and Gross Motor, and Adaptive Behavior development. The psychometric properties of a total of 118 subscales of IDADI were obtained and the IDADI-short age-specific scores were correlated with the original inventory, and criteria variables such as neurodevelopment diagnosis, socioeconomic status, and sex. Results: Item Response Theory analysis, Cronbach’s Alpha, and McDonald’s Omega indicated excellent internal consistency and optimal participant discrimination after minor alterations. IDADI-short scores were strongly associated with the original inventory, with high sensibility and specificity precision for developmental delays. Significant associations with relevant criteria variables were also observed. Conclusion: Findings support the use of IDADI-short as a parental measure of young children’s development

Impurity effects in superconducting UPt3

Superconducting UPt3 is characterized by a novel and complex magnetic field‐temperature phase diagram, with two superconducting transitions at Tc1 and Tc2 in zero field. We have studied the effects of Pd and Y impurities on the zero field superconducting properties of UPt3. Resistance measurements show that both dopants increase the residual resistivity and decrease the spin fluctuation temperature in the normal state. Tc1 is depressed by both dopants, but more effectively by Pd. ‖Tc1 − Tc2‖ is essentially unaffected by Y doping, but increases dramatically with Pd doping.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70706/2/JAPIAU-69-8-5487-1.pd

Gut content metabarcoding of specialized feeders is not a replacement for environmental DNA assays of seawater in reef environments

In tropical marine ecosystems, the coral-based diet of benthic-feeding reef fishes provides a window into the composition and health of coral reefs. In this study, for the first time, we compare multi-assay metabarcoding sequences of environmental DNA (eDNA) isolated from seawater and partially digested gut items from an obligate corallivore butterflyfish (Chaetodon lunulatus) resident to coral reef sites in the South China Sea. We specifically tested the proportional and statistical overlap of the different approaches (seawater vs gut content metabarcoding) in characterizing eukaryotic community composition on coral reefs. Based on 18S and ITS2 sequence data, which differed in their taxonomic sensitivity, we found that gut content detections were only partially representative of the eukaryotic communities detected in the seawater based on low levels of taxonomic overlap (3 to 21%) and significant differences between the sampling approaches. Overall, our results indicate that dietary metabarcoding of specialized feeders can be complimentary to, but is no replacement for, more comprehensive environmental DNA assays of reef environments that might include the processing of different substrates (seawater, sediment, plankton) or traditional observational surveys. These molecular assays, in tandem, might be best suited to highly productive but cryptic oceanic environments (kelp forests, seagrass meadows) that contain an abundance of organisms that are often small, epiphytic, symbiotic, or cryptic.</p

Non-adiabatic and time-resolved photoelectron spectroscopy for molecular systems

We quantify the non-adiabatic contributions to the vibronic sidebands of equilibrium and explicitly time-resolved non-equilibrium photoelectron spectra for a vibronic model system of Trans-Polyacetylene. Using exact diagonalization, we directly evaluate the sum-over-states expressions for the linear-response photocurrent. We show that spurious peaks appear in the Born-Oppenheimer approximation for the vibronic spectral function, which are not present in the exact spectral function of the system. The effect can be traced back to the factorized nature of the Born-Oppenheimer initial and final photoemission states and also persists when either only initial, or final states are replaced by correlated vibronic states. Only when correlated initial and final vibronic states are taken into account, the spurious spectral weights of the Born-Oppenheimer approximation are suppressed. In the non-equilibrium case, we illustrate for an initial Franck-Condon excitation and an explicit pump-pulse excitation how the vibronic wavepacket motion of the system can be traced in the time-resolved photoelectron spectra as function of the pump-probe delay

Los contextos sociales e institucionales de una economía monástica: Santa María de Montederramo en el siglo XIII

Editada en la Fundación Empresa PúblicaLa autora se pregunta por las causas de la consolidación y pervivencia de formas institucionales ineficientes desde un punto de vista económico. Se estudia un caso concreto: el monasterio cisterciense de Santa María de Montederramo (Orense) en el siglo XIII para poner en evidencia la existencia de marcos institucionales formales e informales definidores de la acción de unos agentes cuyos intereses se construyeron en el proceso de interacción social, es decir, en contextos socio-culturales determinados y no como fruto de la limitación institucional sobre la naturaleza maximizadora de agentes extemporales. En primer lugar, el artículo presenta las paradojas en los debates clásicos sobre el Císter. Atendiendo a la Regla de la Orden, se acepta que el Císter perseguía varios objetivos: la compactación de las parcelas adquiridas, la tenencia en régimen de propiedad no compartida y la explotación de la tierra con mano de obra propia. A partir del caso elegido se reflexiona sobre la distancia entre los principios teóricos de la Orden y la morfología diversa de los señoríos y sus formas de gestión práctica. Se concluye que los monasterios se convirtieron en aparatos acumuladores de bienes invirtiendo recursos según criterios de reciprocidad, redistribución, identidad y estableciendo redes con las comunidades o con algunos de sus miembros destacados. En este compacto entramado de dinámicas sociales y mentales se fueron configurando sus formas económicas.The author searches into the reasons for the perpetuation in inefficient institutions. The monastery in Sta. María de Montederramo (Orense, Galicia) in the 13th century lets to underline the existence of formal and informal institutions defíning agents' cholees whose interests are building up in the process of social interaction. Moreover those interests emerge within socio-cultural context, rather than as the outcome of the institutional constreints over a given nature as profit maximazers. The article reviews the classical debate about the Cister. Given the Rule of the Order it is argued that Cistercians pursued the organization of coherent territorial estates, exclusive property rights over the land and own labour force. Working on the case-study, the gap between the theoretical principie of the Order and the specif management and contractual agreements about land tenancy are considered. The conclusion puts forward that monasteries were devices of accumulation because they developed practices of reciprocity, redistribution and identity within the peasant communities and through the organization of personal and social networks with some of the outstanding members of the local community. In the tied web of social and cultural dynamics, the economic patterns were hammered out.Publicad