A potential role for rare species in ecosystem dynamics.

The ecological importance of common species for many ecosystem processes and functions is unquestionably due to their high abundance. Yet, the importance of rare species is much less understood. Here we take a theoretical approach, exposing dynamical models of ecological networks to small perturbations, to explore the dynamical importance of rare and common species.

Carnitine acetyltransferase: A new player in skeletal muscle insulin resistance?

Carnitine acetyltransferase (CRAT) deficiency has previously been shown to result in muscle insulin resistance due to accumulation of long-chain acylcarnitines. However, differences in the acylcarnitine profile and/or changes in gene expression and protein abundance of CRAT in myotubes obtained from obese patients with type 2 diabetes mellitus (T2DM) and glucose-tolerant obese and lean controls remain unclear. The objective of the study was to examine whether myotubes from obese patients with T2DM express differences in gene expression and protein abundance of CRAT and in acylcarnitine species pre-cultured under glucose and insulin concentrations similar to those observed in healthy individuals in the over-night fasted, resting state.

The heterozygous N291S mutation in the lipoprotein lipase gene impairs whole-body insulin sensitivity and affects a distinct set of plasma metabolites in humans.

Background: Mutations in the lipoprotein lipase gene causing decreased lipoprotein lipase activity are associated with surrogate markers of insulin resistance and the metabolic syndrome in humans.

Objective: We investigated the hypothesis that a heterozygous lipoprotein lipase mutation (N291S) induces whole-body insulin resistance and alterations in the plasma metabolome.

Methods: In 6 carriers of a heterozygous lipoprotein lipase mutation (N291S) and 11 age-matched and weight-matched healthy controls, we examined insulin sensitivity and substrate metabolism by euglycemic-hyperinsulinemic clamps combined with indirect calorimetry.

Contact heat evoked potentials: normal values and use in small-fiber neuropathy.

Introduction: Contact heat evoked potentials (CHEPs) may be an objective, non-invasive diagnostic tool in small-fiber neuropathy (SFN). This study establishes normal CHEP values and examines their applicability in SFN patients.

Methods: Standardized CHEPs were administered at the wrist and ankle.

Sense of coherence in first-time parents: a longitudinal study.

Background: Antonovsky's idea of sense of coherence (SOC) is related to wellbeing and is of importance for individuals in public health care. SOC in parents with healthy children has not previously been studied. The objectives of this study were (1) to describe the SOC of first-time parents during the first 8 years of their child's life, (2) to describe gender differences in regards to SOC, and (3) to describe covariates with SOC in the parents' life situations.

Species-rich ecosystems are vulnerable to cascading extinctions in an increasingly variable world.

Global warming leads to increased intensity and frequency of weather extremes. Such increased environmental variability might in turn result in increased variation in the demographic rates of interacting species with potentially important consequences for the dynamics of food webs. Using a theoretical approach, we here explore the response of food webs to a highly variable environment.