Article explores the ‘membrane pacemaker’ hypothesis which proposes a biochemical explanation for among-species variation in resting metabolism, based on the positive correlation between membrane docosahexaenoic acid (DHA) and metabolic rate. The authors tested this hypothesis using a novel model, altricial red-winged blackbird nestlings, predicting that the proportion of DHA in muscle and liver membranes should increase with the increasing metabolic rate of the nestling as it develops endothermy. In support of the membrane pacemaker hypothesis, DHA proportions increased in membranes from pectoralis muscle, muscle mitochondria and liver during post-hatch development. By contrast, elevated dietary DHA had no effect on resting metabolic rate, despite causing significant changes to membrane lipid composition.

This article uses the self-organized temporal criticality (SOTC) model to identify the timing of crucial events as a new mechanism with which to generate criticality, thereby establishing a way for the internal dynamics of the decision making process to suppresss the sensitivity of social opinion to either zealot or independent minorities.

This article reports on the origin, evolution, and diversification of the iron-sulfur (2Fe-2S) binding motif CDGSH.

Rate coefficients, k, for the gas-phase reaction of the OH radical with (E)CF3CHCHCF3 ((E)-1,1,1,4,4,4-hexafluoro-2-butene, HFO-1336mzz(E)) were measured over a range of temperatures (211−374 K) and bath gas pressures (20−300 Torr; He, N2) using a pulsed laser photolysis−laser-induced fluorescence (PLP−LIF) technique. k1(T) was independent of pressure over this range of conditions with k1(296 K) = (1.31 ± 0.15) × 10−13 cm3 molecule−1 s−1 and k1(T) = (6.94 ± 0.80) × 10−13exp[−(496 ± 10)/T] cm 3 molecule−1 s−1, where the uncertainties are 2σ, and the pre-exponential term includes estimated systematic error. Rate coefficients for the OD reaction were also determined over a range of temperatures (262−374 K) at 100 Torr (He). The OD rate coefficients were ∼15% greater than the OH values and showed similar temperature dependent behavior with k2(T) = (7.52 ± 0.44) × 10−13exp[−(476 ± 20)/T] and k2(296 K) = (1.53 ± 0.15) × 10−13 cm3 molecule−1 s−1. The rate coefficients for reaction 1 were also measured using a relative rate technique between 296 and 375 K with k1(296 K) measured to be (1.22 ± 0.1) × 10−13 cm3 molecule−1 s−1, in agreement with the PLP−LIF results. In addition, the 296 K rate coefficient for the O3 +( E)CF3CHCHCF3 reaction …

This article proposes a social model of spontaneous self-organization generating criticality and resilience, called Self-Organized Temporal Criticality (SOTC).

Article describes a study which examines the conduction system in crocodiles (Alligator mississippiensis), the only ectothermic vertebrates with a full ventricular septum.