Phenomenological study of the electronic transport coefficients of graphene

Using a semi-classical approach and input from experiments on the conductivity of graphene, we determine the electronic density dependence of the electronic transport coefficients -- conductivity, thermal conductivity and thermopower -- of doped graphene. Also the electronic density dependence of the optical conductivity is obtained. Finally we show that the classical Hall effect (low field) in graphene has the same form as for the independent electron case, characterized by a parabolic dispersion, as long as the relaxation time is proportional to the momentum.Comment: 4 pages, 1 figur

Portuguese consensus document statement in diagnostic and management of atypical hemolytic uremic syndrome

Among thrombotic microangiopathies (TMA), the hemolytic uremic syndrome associated with dysregulation of the alternative complement pathway (aHUS) is one of the most challenging diseases a nephrologist can face. By the end of the XXth century, the complement’s role was unraveled with the discovery that mutations in the factor H coding gene were responsible for aHUS. But it was the acknowledgment that pharmacological C5-9 blockage provided a cure for aHUS that fostered the interest of the nephrology community in the genetics, pathophysiology and therapeutics of, not only of aHUS, but TMA in general. The molecular genetics of aHUS is technically demanding and, as such, in Portugal (alike many other European countries) a single laboratory emerged as a national reference center. The fact that all samples are evaluated in a single center provides a unique opportunity for data collection and a forum for discussion for all those interested in the field: immunologists, molecular geneticists, pathologists and nephrologists. The current consensus document emerged from such a discussion forum and was sponsored by the Portuguese Society of Nephrology. The goal is more to portray the Portuguese picture regarding the diagnostic approach and therapeutic options than to extensively review the state of the art of the subject. The accompanying documents that are published as supplementary data are in line with that goal. They range from the informed consent and clinical form to be sent together with the biological samples for genetic testing, to the appendix regarding the actual sampling and storing conditions. The document is also intended to set an example for future documents and independente discussion forums on other kidney diseases for which emerging diagnostic and/or therapeutic strategies are reaching clinical practice.info:eu-repo/semantics/publishedVersio

Electron waves in chemically substituted graphene

We present exact analytical and numerical results for the electronic spectra and the Friedel oscillations around a substitutional impurity atom in a graphene lattice. A chemical dopant in graphene introduces changes in the on-site potential as well as in the hopping amplitude. We employ a T-matrix formalism and find that disorder in the hopping introduces additional interference terms around the impurity that can be understood in terms of bound, semi-bound, and unbound processes for the Dirac electrons. These interference effects can be detected by scanning tunneling microscopy.Comment: 4 pages, 7 figure

Tópico de submissão do trabalho: 15 melhoramento genético avaliação preliminar do potencial germinativo de linhagens e híbridos de mamoeiro (Carica Papaya L.) em telado.

A espécie Carica papaya L. é, dentre todas as espécies de mamoeiro, a mais cultivada no mundo, apresentando como provável centro de origem o Noroeste da América do Sul, a vertente oriental dos Andes, ou, mais precisamente, a Bacia Amazônica Superior com máxima diversidade genética (Sanches & Dantas, 1999). O Brasil é a nação que apresenta a maior produção de mamão, 1.440.000 t, cultivado em todos os estados da federação. A região Nordeste concentra a maior área de plantio, cerca de 30 mil hectares (Nakamae, 2003). Em Pernambuco a produção é pouco expressiva, correspondendo a 10.097 t obtidas em 578 hectares, equivalente ao rendimento médio anual de 17,74 t / ha (Agrianual, 2006).pdf 147

Ecological adaptation of wild peach palm, its in situ conservation and deforestation-mediated extinction in Southern Brazilian Amazonia.

The Arc of Fire across southern Amazonia seasonally attracts worldwide attention as forests are cut and burned for agricultural expansion. These forests contain numerous wild relatives of native South American crops, such as peach palm

Cultivares e híbridos de repolho para produção orgânica no verão do Distrito Federal.

Este trabalho teve como objetivo avaliar o desempenho agronômico de algumas cultivares e hibridos de repolho em sistema orgânico nas condições de verão do Distrito Federal.Trabalho apresentado no 4 Seminário de Agroecologia do Distrito Federal e Entorno, Brasília, DF