As caraterísticas dos principais tipos de solos do estado de São Paulo

As caraterísticas geológicas, físicas e químicas, de 22 entre os principais tipos de solos do Estado de S. Paulo, são estudadas. A descrição dessas caraterísticas é feita quantitativamente por meio de uma série de 56 diagramas, cuja significação e método de leitura estão explicados. As regiões dos 22 tipos de solos estão descritas quanto à sua localização, caraterísticas geológicas, topográficas, fitogeográficas e pluvio-métricas, além de notas sôbre os tipos de exploração e sôbre o uso racional dos solos. Dos 56 diagramas, os 12 primeiros comparam entre si cerca de quatro dezenas de caraterísticas diversas, físicas e químicas, da parte arável dos 22 tipos principais de solos descritos. Os 44 diagramas seguintes são diagramas volumétricos físicos e químicos completos dos 22 perfis típicos, tomados até a profundidade de 150 cm e divididos nos vários horizontes genéticos do solo.<br>The geological, physical and chemical problems dealing with the characteristics of 22 of the principal types of soils of the State of São Paulo are studied. The description of these characteristics is given quantitatively through a series of 56 diagrams, the adequate signification of which are explained. The regions of the 22 soil types are described in a abridged form as for the extent, location, geological, topographical, phytogeographical and pluviometric characteristics. Some notes referring to the rational utilization of some of these soils are given. Of the 56 diagrams presented, the 12 first mentioned are intended to compare about forty different physical and chemical characteristics of arable soil of the 22 types described. The 44 remaining graphs are physical and chemical volumetric diagrams of the 22 typical profiles, taken at the depth as far as 150 cm and divided in several genetic horizons

Imunopatogênese da psoríase: revisando conceitos Reviewing concepts in the immunopathogenesis of psoriasis

O conhecimento sobre a fisiopatogenia da psoríase possibilitou o desenvolvimento de ferramentas terapêuticas que visam ao bloqueio do seu gatilho imunológico. Paralelamente, citocinas como o TNF têm sido reconhecidas como integrantes da etiopatogenia da psoríase e comorbidades a ela relacionadas. Estudos genéticos e epidemiológicos contribuíram efetivamente para as conclusões a que se tem chegado atualmente sobre esta complexa patologia.<br>Insights into the pathogenesis of psoriasis led to the development of therapeutic tools aimed at blocking its immunological trigger. In parallel, cytokines such as the tumor necrosis factor (TNF) have been recognized as playing a crucial role in the pathogenesis of psoriasis and its associated comorbidities. Genetic and immunological studies have contributed effectively towards establishing the currently held concepts regarding this complex disease

Thymic regulatory T cell niche size is dictated by limiting IL-2 from antigen-bearing dendritic cells and feedback competition

The thymic production of regulatory T cells (Treg cells) requires interleukin 2 (IL-2) and agonist T cell antigen receptor (TCR) ligands and is controlled by competition for a limited developmental niche, but the thymic sources of IL-2 and the factors that limit access to the niche are poorly understood. Here we found that IL-2 produced by antigen-bearing dendritic cells (DCs) had a key role in Treg cell development and that existing Treg cells limited new development of Treg cells by competing for IL-2. Our data suggest that antigen-presenting cells (APCs) that can provide both IL-2 and a TCR ligand constitute the thymic niche and that competition by existing Treg cells for a limited supply of IL-2 provides negative feedback for new production of Treg cells