Lists of species underpin many fields of human endeavour, but there are currently no universally accepted principles for deciding which biological species should be accepted when there are alternative taxonomic treatments (and, by extension, which scientific names should be applied to those species). As improvements in information technology make it easier to communicate, access, and aggregate biodiversity information, there is a need for a framework that helps taxonomists and the users of taxonomy decide which taxa and names should be used (...) by society whilst continuing to encourage taxonomic research that leads to new species discoveries, new knowledge of species relationships, and the refinement of existing species concepts. Here, we present 10 principles that can underpin such a governance framework, namely (i) the species list must be based on science and free from nontaxonomic considerations and interference, (ii) governance of the species list must aim for community support and use, (iii) all decisions about list composition must be transparent, (iv) the governance of validated lists of species is separate from the governance of the names of taxa, (v) governance of lists of accepted species must not constrain academic freedom, (vi) the set of criteria considered sufficient to recognise species boundaries may appropriately vary between different taxonomic groups but should be consistent when possible, (vii) a global list must balance conflicting needs for currency and stability by having archived versions, (viii) contributors need appropriate recognition, (ix) list content should be traceable, and (x) a global listing process needs both to encompass global diversity and to accommodate local knowledge of that diversity. We conclude by outlining issues that must be resolved if such a system of taxonomic list governance and a unified list of accepted scientific names generated are to be universally adopted. (shrink)

Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin‐converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems (RAS), which also regulate diverse aspects of whole‐body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3‐55C (rather than (...) T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P < 0·01) whilst increasing ACE expression within a physiological range (<1·8‐fold at 48 h; P < 0·01). Our findings suggest novel hypotheses. Firstly, cellular feedback regulation may occur between UCPs and ACE. Secondly, cellular UCP regulation of sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role. (shrink)

At extreme altitude (>5,000 – 5,500 m), sustained hypoxia threatens human function and survival, and is associated with marked involuntary weight loss (cachexia). This seems to be a coordinated response: appetite and protein synthesis are suppressed, and muscle catabolism promoted. We hypothesise that, rather than simply being pathophysiological dysregulation, this cachexia is protective. Ketone bodies, synthesised during relative starvation, protect tissues such as the brain from reduced oxygen availability by mechanisms including the reduced generation of reactive oxygen species, improved mitochondrial (...) efficiency and activation of the ATP‐sensitive potassium (KATP) channel. Amino acids released from skeletal muscle also protect cells from hypoxia, and may interact synergistically with ketones to offer added protection. We thus propose that weight loss in hypoxia is an adaptive response: the amino acids and ketone bodies made available act not only as metabolic substrates, but as metabolic modulators, protecting cells from the hypoxic challenge.Also watch the Video Abstract. (shrink)

Nous considérons la structure dans son rapport au temps : sous ce rapport, la structure est normative, et l’avenir aide à constituer le présent et le passé. Des exemples sont empruntés à l’embryologie et à la géologie. On explique pourquoi il est difficile de concevoir une structure cosmique spatio-temporelle, et comment le développement récent de la physique nous y aide ; dans cette physique, la notion de structure cosmique a un rôle éminent. Il en résulte que seules sont viables les (...) combinaisons qui sont dans La ligne historique de la nature. (shrink)