Sphingolipid subtypes differentially control proinsulin processing and systemic glucose homeostasis.

Impaired proinsulin-to-insulin processing in pancreatic β-cells is a key defective step in both type 1 diabetes and type 2 diabetes (T2D) (refs. 1,2), but the mechanisms involved remain to be defined. Altered metabolism of sphingolipids (SLs) has been linked to development of obesity, type 1 diabetes and T2D (refs. 3–8); nonetheless, the role of specific SL species in β-cell function and demise is unclear. Here we define the lipid signature of T2D-associated β-cell failure, including an imbalance of specific very-long-chain SLs and long-chain SLs. β-cell-specific ablation of CerS2, the enzyme necessary for generation of very-long-chain SLs, selectively reduces insulin content, impairs insulin secretion and disturbs systemic glucose tolerance in multiple complementary models. In contrast, ablation of long-chain-SL-synthesizing enzymes has no effect on insulin content. By quantitatively defining the SL–protein interactome, we reveal that CerS2 ablation affects SL binding to several endoplasmic reticulum–Golgi transport proteins, including Tmed2, which we define as an endogenous regulator of the essential proinsulin processing enzyme Pcsk1. Our study uncovers roles for specific SL subtypes and SL-binding proteins in β-cell function and T2D-associated β-cell failure

The structure and reproduction of the virgin forest - a review of Eustace Jones 1945

Jones (1945) was a milestone paper exploring the natural forest concept with examples from the temperate and boreal ecosystems. It has become a classic because of its use of field observation of regeneration, succession and structure to assess theories about disturbance and the dynamic properties of natural forests. His main aim was to review some of the features of the structure and reproduction of the north temperate virgin forests, and this article presents, discusses and evaluates the main features of this legendary paper. Jones had international experience of both the ecological and silvicultural research communities and combined long-term field observations with theory to develop a realistic assessment of natural forest properties that formed the basis for current understanding. He demonstrated that natural disturbance regimes could generate a variety of structures and that a stable, ‘‘climax’’ forest concept was often not supported by field data. He also showed that even-aged components are common in these forest ecosystems and that the recruitment of tree species proceeds irregularly even in undisturbed stands. His work has influenced subsequent development of related subjects such as disturbance theory, gap-phase dynamics and long-term vegetation changes and has left a legacy with practical relevance for nature conservation and silviculture

As Apocynaceae s. str. da região de Bauru, São Paulo, Brasil The Apocynaceae s. str. of the Bauru region, São Paulo State, Brazil

Este trabalho consistiu no levantamento das Apocynaceae na Região de Bauru, centro-oeste do estado de São Paulo, em diferentes tipos de vegetação. Foram encontradas 25 espécies, distribuídas em 15 gêneros, representadas nesta ordem: Forsteronia G. Mey., cinco espécies; Aspidosperma Mart., quatro espécies; Mandevilla Lindl., três espécies; Prestonia R. Br., duas espécies, e Condylocarpon Desf., Hancornia Gomez, Himatanthus Willd. ex Roem. et Schult., Macrosiphonia Müll.Arg., Mesechites Müll.Arg., Odontadenia Benth., Peltastes Woodson, Rhodocalyx Müll.Arg., Secondatia A. DC., Tabernaemontana L. e Temnadenia Miers, uma espécie cada. São apresentadas chaves de identificação, descrições e ilustrações das espécies, além de dados de distribuição geográfica, floração e frutificação.<br>The present study describes a survey of the Apocynaceae in different types of vegetation, in the region of Bauru, in the Center-West of São Paulo State. Of the 25 species encountered, distributed into 15 genera, representation ranges as follows: Forsteronia G. Mey, five species; Aspidosperma Mart., four species; Mandevilla Lindl., three species; Prestonia R. Br., two species; and Condylocarpon Desf., Hancornia Gomez, Himatanthus Willd. ex Roem. et Schult., Macrosiphonia Müll. Arg., Mesechites Müll. Arg., Odontadenia Benth, Peltastes Woodson, Rhodocalyx Müll Arg., Secondatia A. DC., Tabernaemontana L. and Temnadenia Miers, one species each. In addition to both distribution data, and flowering and fruiting times, identifications keys, descriptions and illustrations of the species are presented