The global biogeography of tree leaf form and habit.

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records.

The call-bell in residential care homes: Experiences of residents and staff.

Background/objectives: Call-bells are often taken-for-granted systems to heighten safety. In joint discussions among residential care home (RCH) residents, their family members, and staff, issues related to call-bell use in everyday life and work were repeatedly raised. In this article, we explore these experience-based perspectives, addressing several key questions important for call-bell use and communication.

Multiple drivers of large-scale lichen decline in boreal forest canopies.

Thin, hair-like lichens (Alectoria, Bryoria, Usnea) form conspicuous epiphyte communities across the boreal biome. These poikilohydric organisms provide important ecosystem functions and are useful indicators of global change. We analyse how environmental drivers influence changes in occurrence and length of these lichens on Norway spruce (Picea abies) over 10 years in managed forests in Sweden using data from >6000 trees.

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels.

Plant functional traits have globally consistent effects on competition.

Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological functions, but how these effects scale up to influence competition, a key driver of community assembly in terrestrial vegetation, has remained unclear. Here we use growth data from more than 3 million trees in over 140,000 plots across the world to show how three key functional traits--wood density, specific leaf area and maximum height--consistently influence competitive interactions. Fast maximum growth of a species was correlated negatively with its wood density in all biomes, and positively with its specific leaf area in most biomes.

Higher levels of multiple ecosystem services are found in forests with more tree species.

Forests are of major importance to human society, contributing several crucial ecosystem services. Biodiversity is suggested to positively influence multiple services but evidence from natural systems at scales relevant to management is scarce. Here, across a scale of 400,000 km(2), we report that tree species richness in production forests shows positive to positively hump-shaped relationships with multiple ecosystem services.

Construction of a DOPC/PSM/cholesterol phase diagram based on the fluorescence properties of trans-parinaric acid.

Cell membranes have a nonhomogenous lateral organization. Most information about such nonhomogenous mixing has been obtained from model membrane studies where defined lipid mixtures have been characterized. Various experimental approaches have been used to determine binary and ternary phase diagrams for systems under equilibrium conditions.

Sterol affinity for bilayer membranes is affected by their ceramide content and the ceramide chain length.

It is known that ceramides can influence the lateral organization in biological membranes. In particular ceramides have been shown to alter the composition of cholesterol and sphingolipid enriched nanoscopic domains, by displacing cholesterol, and forming gel phase domains with sphingomyelin. Here we have investigated how the bilayer content of ceramides and their chain length influence sterol partitioning into the membranes.

Characterization of membrane properties of inositol phosphorylceramide.

Inositol phosphorylceramides (IPCs) are a class of anionic sphingolipids with a single inositol-phosphate head group coupled to ceramide. IPCs and more complex glycosylated IPCs have been identified in fungi, plants and protozoa but not in mammals. IPCs have also been identified in detergent resistant membranes in several organisms.

Ceramide acyl chain length markedly influences miscibility with palmitoyl sphingomyelin in bilayer membranes.

Ceramides are precursors of major sphingolipids and can be important cellular effectors. The biological effects of ceramides have been suggested to stem from their biophysical effects on membrane structure affecting the lateral and transbilayer organization of other membrane components. In this study we investigated the effect of acyl chain composition in ceramides (C4-C24:1) on their miscibility with N-palmitoyl-sphingomyelin (PSM) using differential scanning calorimetry.

Differential ability of cholesterol-enriched and gel phase domains to resist benzyl alcohol-induced fluidization in multilamellar lipid vesicles.

Benzyl alcohol (BA) has a well-known fluidizing effect on both artificial and cellular membranes. BA is also likely to modulate the activities of certain membrane proteins by decreasing the membrane order. This phenomenon is presumably related to the ability of BA to interrupt interactions between membrane proteins and the surrounding lipids by fluidizing the lipid bilayer.

Thermotropic behavior and lateral distribution of very long chain sphingolipids.

Sphingolipids containing very long acyl chains are abundant in certain specialized tissues and minor components of plasma membranes in most mammalian cells. There are cellular processes in which these sphingolipids are required, and the function seems to be mediated through sphingolipid-rich membrane domains. This study was conducted to explore how very long acyl chains of sphingolipids influence their lateral distribution in membranes.

How the molecular features of glycosphingolipids affect domain formation in fluid membranes.

Glycosphingolipids, sphingomyelin and cholesterol are often all found in the detergent resistant fraction of biological membranes and are therefore recognized as raft components, but they do not necessarily co-localize in the same lateral domains. From cell biological studies it is evident that different sphingolipid species can be found in different lateral regions within the same cellular membrane. Biophysical studies have shown that their tendency to co-localize with each other and with other membrane components is largely governed by structural features of all lipids present.

The three-dimensional structures of two toxins from snake venom throw light on the anticoagulant and neurotoxic sites of phospholipase A2.

The three-dimensional structures of the class II anticoagulant phospholipase A2 (PLA2) toxin RVV-VD from the venom of Russell's viper, Vipera russelli russelli, and the class I neurotoxic PLA2 Notechis II-5 from the, Australian tiger snake, Notechis scutatus scutatus, were determined to 2.2 A and 3.0 A resolution, respectively.

Changes to biological activity following acetylation of dendrotoxin I from Dendroaspis polylepis (black mamba).

The potassium channel blocker dendrotoxin I was acetylated with acetic anhydride. Mono-acetyl derivatives of all seven lysine residues (N-terminus blocked) and a di-derivative were isolated by chromatography on the cation-exchanger Bio-Rex 70 and reversed-phase high-performance liquid chromatography. The derivative acetyl-Lys 29 and the di-derivative of Tyr 24 and Lys 28 had more than 1000 times lower affinity than the native toxin as determined by inhibition of the 125I-dendrotoxin binding to synaptosomal membranes from rat brain.

Crystallographic investigation of the dependence of calcium and phosphate ions for notexin.

The crystal structure of the neurotoxic phospholipase A2, notexin, revealed three binding sites for sulphate ions which were suggested to be phosphate binding sites of importance for the activity of the toxin. The present investigation shows that the sulphate ion bound to the major binding site alters the structure of residues 60-75. In the absence of sulphate and phosphate, the structure of this loop has a conformation which partly resembles the non-neurotoxic PLA2s.

A Collagen-Binding S-Layer Protein in Lactobacillus crispatus.

Two S-layer-expressing strains, Lactobacillus crispatus JCM 5810 and Lactobacillus acidophilus JCM 1132, were assessed for adherence to proteins of the mammalian extracellular matrix. L. crispatus JCM 5810 adhered efficiently to immobilized type IV and I collagens, laminin, and, with a lower affinity, to type V collagen and fibronectin.

Bacterial proteins binding to the mammalian extracellular matrix.

Pathogenic bacteria frequently express surface proteins with affinity for components of the mammalian extracellular matrix, i.e. collagens, laminin, fibronectin or proteoglycans.

P fimbriae of uropathogenic Escherichia coli as multifunctional adherence organelles.

P fimbriae are the major single virulence factor of uropathogenic Escherichia coli strains. Recent analyses have shown that P fimbriae possess two distinct binding specificities mediated by different fimbrial subunits. P fimbriae bind to Gal alpha (1-4)Gal-containing globoseries of glycolipids of epithelial cells; this binding is mediated by the lectin-like minor protein G of the filament.