The acidic peatlands of southern Brazil are ecosystems essential for the maintenance of the Atlantic Forest, one of the 25 hot-spots of biodiversity in the world. In this work, we investigated the composition of prokaryotic communities in four histosols of three acidic peatland regions by constructing small-subunit (SSU) rRNA gene libraries and sequencing. SSU rRNA gene sequence analysis showed the prevalence of Acidobacteria (38.8%) and Proteobacteria (27.4%) of the Bacteria domain and Miscellaneous (58%) and Terrestrial (24%) groups of Crenarchaeota of the Archaea domain. As observed in other ecosystems, archaeal communities showed lower richness than bacterial communities. We also found a limited number of Euryarchaeota and of known methanotrophic bacteria in the clone libraries.

We have studied the magnetic behavior of a 4d transition metal Rh monolayer (ML) on different substrates (Ag, Au, Cu) and orientations. We find the Rh monolayer to be magnetic in the (001) orientation on all the substrates, in the (111) direction for Au and Ag alone (µ ≈ 0.6 µB) for both, in the (110) one we do not find any magnetic activity. We analyze the parameters that have been suggested as general criteria for magnetism in the monolayer-substrate system. In particular, we study several possible geometric parameters and the bandwidth as possible clues to predict the magnetic behavior. A detailed analysis shows that the physics underlying the switching on of magnetism in a Rh-ML on noble metal substrates, is determined by an intraband transfer of d-electronic states (as compared to the Rh surface), from lower and higher energies to the Fermi level. This effect enhances the density of states at that energy, in an important way and shrinks the d-bandwidth. It seems to depend strongly on specificities of the interaction between the ML and the substrate that are hardly taken into account by a single parameter, in a general way. We impose charge neutrality in our calculations but deal explicitly with the changes to be expected if charge transfer would actually occur.

Presentamos el estudio de la actividad magnética de una monocapa de Rh sobre sustratos de (Ag, Au, Cu), en las tres direcciones principales (001), (111) y (110). Comparamos nuestros resultados con trabajos anteriores. Encontramos actividad magnética de la monocapa de Rh sobre Au(111) y Ag(111) (µ ≈ 0.6 µB) en ambos. Encontramos también que sobre Cu, sólo en la dirección (001), la monocapa tiene alguna actividad magnética. Este hecho lo inclina a uno a pensar que la constante de red del sustrato, es la que gobierna la aparición del momento magnético. Sin embargo, sucede que en la dirección (110) no aparece momento magnético ni sobre Ag ni sobre Au. Por esta razón intentamos buscar otro parámetro geométrico como criterio fundamental para la aparición del magnetismo. Ensayamos varios y sólo encontramos correlación con el volumen por átomo en la región de la interface monocapa-sustrato, Ω0. Este parámetro, sin embargo, no parece seguir la tendencia que uno esperaría intuitivamente y, por lo tanto, no debe ser de validez general. Esto, efectivamente, fue lo que comprobamos, estudiando otro tipo de sustratos. Concluimos que la actividad magnética depende de detalles específicos que no pueden caracterizarse sólo por un parámetro geométrico. En nuestros cálculos usamos neutralidad de carga, pero tratamos el problema de lo que ocurriría si hay transferencia de carga.

São apresentados os resultados de estudo multidisciplinar de 15 pacientes com esclerose tuberosa, 8 do sexo masculino e 7 do sexo feminino, com idades entre 19 meses e 23 anos; 11 foram considerados como casos esporádicos e, em 4, não foi possível precisar os antecedentes familiares. Foram observadas as seguintes manifestações cutâneas: adenoma de Pringle em 9 casos; manchas acrômicas em 9 casos; fibroma periungueal em 3 casos. Dos 15 casos 13 apresentaram D.M., deficiência mental, enquanto os outros 2 tinham inteligência limítrofe. Com exceção de 2 pacientes, todos tinham crises epilépticas e os tipos de crises mais frequentemente observados foram as ausências atípicas e as crises tônicas. Espasmos infantis estavam presentes em 3 casos e em apenas um caso o eletrencefalograma apresentou aspecto hipsarrítmico. A tomografia axial computadorizada, realizada em 7 casos, revelou calcificações periventriculares em todos, mesmo naqueles que apresentaram RX simples de crânio normal (4 casos).

Report of a multidisciplinary study of patients affected with tuberous sclerosis, 8 of them males and 7 females, with ages ranging from 19 months to 23 years; 11 of these cases were sporadic, while the remaining 4 cases lacked information regarding family data. The following skin signs were observed: Pringle's adenoma in 9 cases; achromatic spots in 9 cases; periungueal fibroma in 3 cases. One of the patients had a heart tumor. Two patients had borderline intelligence, while the other 13 were mentally retarded of varying degrees. Epileptic seizures were present in 13 patients, atypical absence and tonus crises were frequent. Three of the patients had had infantile spasms in the first year of life as the first neurological symptom of the disease. Computer assisted axial tomography was performed in 7 cases and was positive in all of them, by revealing intracranial calcifications even in 4 cases in which the standard X - ray pictures had been silent about this eventuality.