A major difference between the divergence patterns within the lines-1 families in mice and voles

L1 retroposons are represented in mice by subfamilies of interspersed sequences of varied abundance. Previous analyses have indicated that subfamilies are generated by duplicative transposition of a small number of members of the L1 family, the progeny of which then become a major component of the murine L1 population, and are not due to any active processes generating homology within preexisting groups of elements in a particular species. In mice, more than a third of the L1 elements belong to a clade that became active approximately 5 Mya and whose elements are > or = 95% identical. We have collected sequence information from 13 L1 elements isolated from two species of voles (Rodentia: Microtinae: Microtus and Arvicola) and have found that divergence within the vole L1 population is quite different from that in mice, in that there is no abundant subfamily of homologous elements. Individual L1 elements from voles are very divergent from one another and belong to a clade that began a period of elevated duplicative transposition approximately 13 Mya. Sequence analyses of portions of these divergent L1 elements (approximately 250 bp each) gave no evidence for concerted evolution having acted on the vole L1 elements since the split of the two vole lineages approximately 3.5 Mya; that is, the observed interspecific divergence (6.7%-24.7%) is not larger than the intraspecific divergence (7.9%-27.2%), and phylogenetic analyses showed no clustering into Arvicola and Microtus clades.      

Middle Pleistocene ecology and Neanderthal subsistence: Insights from stable isotope analyses in Payre (Ardèche,southeastern France)

The Middle Palaeolithic site of Payre in southeastern France yields abundant archaeological material associated with fossil hominid remains. With its long sequence of Middle Pleistocene deposits, Payre is a key site to study the Middle Palaeolithic chronology of this region. This study is the first to investigate carbon and oxygen isotope contents of Neanderthal tooth enamel bioapatite, together with a wide range of herbivorous and carnivorous species. The aim is to contribute to the understanding of hunting behaviour, resource partitioning, diet and habitat use of animals and Neanderthals through a palaeoecological reconstruction.     

Multifactorial diversity sustains microbial community stability

Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty.     

Immunohistochemical localization of irisin in skin,eye, and thyroid and pineal glands of the crested porcupine (Hystrix cristata)

Irisin was first identified in muscle cells. We detected irisin immunoreactivity in various organs of the crested porcupine (Hystrix cristata). In the epidermis, irisin immunoreactivity was localized mainly in stratum basale, stratum spinosum and stratum granulosum layers; immunoreactivity was not observed in the stratum corneum. In the dermis, irisin was found in the external and internal root sheath, cortex and medulla of hair follicles, and in sebaceous glands. Irisin immunoreactivity was found in the neural retina and skeletal muscle fibers associated with the eye. The pineal and thyroid glands also exhibited irisin immunoreactivity.     

Les assemblages lithiques des niveaux du Paléolithique moyen de l’Abri des Pêcheurs (Ardèche, Sud-Est de la France): Des occupations néandertaliennes récurrentes dans un « fossé »

The Abri des Pêcheurs has yielded an extraordinary sequence with Middle and Upper Palaeolithic levels. Humans came and stayed in a ditch-cave that has been filled in along time. During Middle Palaeolithic occupations, they used first quartz, and this site is the only case in this area. Assemblages show similar technological behaviour along time. Flint is few employed and arrived as flakes from different areas if we consider its geological variety. Functions of the site are not well established. The base of the sequence has yielded sediments with a mixing of ibex, carnivore bones and artefacts. The study of the lithic assemblages brings information on the processing systems used on quartz and flint during occupations which left few evidence and used local stones while flint is available not far from the site. Hypothesis on short and specialized occupations is discussed.     

Leaving the Oil Under the Amazon: Ecuador's Yasuní-ITT Initiative

Oil and gas concessions now cover vast swaths of the western Amazon, including protected areas and indigenous territories. The Yasuní-ITT Initiative, Ecuador's innovative proposal to leave nearly a billion barrels of oil locked beneath Yasuní National Park, is the first major effort to reverse this trend. We provide a concise overview of the initiative, including an in-depth look at its widely lauded goals of protecting biodiversity, respecting indigenous peoples' territory, and combating climate change. We also discuss the proposal's lingering caveats, such as technical questions regarding the generation of financial resources to replace the forgone oil revenue. We conclude that the Yasuní-ITT Initiative is a potentially precedent-setting advance towards avoiding damaging oil and gas development in sensitive areas.