The Reserve of Biosphere of Camargue French National Nature Reserve of Camargue (NNRC) is a protected area frequently exposed to natural and anthropogenic environmental alterations. To evaluate ...potential contamination of fish with lipophilic chemicals—organochlorines (OCs) and polycyclic aromatic hydrocarbons (PAHs)—a biological monitoring survey was carried out. Metabolic reserve levels were evaluated to select appropriate biological indicators able to be significant biomarkers. In addition, the incorporation of xenobiotic molecules in the lipid compartments was investigated. The contents of glycogen, total lipids, proteins and lipidic phosphorus were analyzed in liver and skeletal muscles of three teleostean: the European eel (
Anguilla anguilla); the crucian carp (
Carassius auratus); and the catfish (
Ictalurus
melas). The atmospheric origin of the PAH detected in any season in the biomass and the OCs compounds contamination by derive from agricultural treatments are established. In contradiction with some laboratory acute intoxication studies, we observe a positive correlation between tissue concentrations of contaminants and the muscular glycogen amount, a sensitive energy reserve marker. Moreover, it seems likely that the incorporation of these xenobiotics is located preferentially in the membrane structures.
The transport of glycine, alanine, methionine and alpha amino-isobutyric acid (AIB) was studied on brush border membrane vesicles of
Boops salpa, a marine fish. This transport was Na
+-, Cl
−- and ...pH-dependent. In the presence of NaCl, the uptake decreased as the pH increased from 5.5 to 8.5. With Na
2SO
4, the transport of the four amino acids was strongly reduced and the pH optimum was 7–8. In the presence of NaCl, amino acid transport was described by high and low affinity kinetics. The
K
t of the high-affinity component was comparable for glycine, alanine and methionine (0.1 mM), and was significantly enhanced for AIB (0.6 mM). The
J
max of the low affinity component was significantly lower for methionine and AIB than for glycine and alanine. Lowering the sodium concentration from 80 to 20 mM significantly increased
K
t and
J
max of the high-affinity component of glycine transport. Moreover, the kinetics of AIB transport under 100 mM Na
+ were similar to glycine kinetics under 40 mM Na
+ and the two amino acids competed for the same carrier(s). These results suggest that chloride ions are essential in neutral amino acid transport in
Boops, that multiple saturable components are involved in this process, and that sodium plays an important role in the differences between the transport kinetics of amino acids.
Over the past 6 Ma, the ways in which our hominin ancestors (all of our ancient relatives since the last common ancestor with chimpanzees) went about their daily activities has drastically evolved. ...Their activities were mostly devoted to finding food and shelter, making and using tools for these tasks, and avoiding attack by predators, probably living in small mobile groups. Hominin diets changed from consisting largely of fruits, leaves, and other plant parts, with insects and meat when possible —similar to the diet of modern great apes— to one dominated by cooked domesticated grains and large quantities of meat today. Hominin social behavior, stone-tool-making developments, and landscape use evolved —not necessarily in lock step— towards the mobile, cooperative, symbolic, and projectile-wielding hunter-foragers from which agriculture and complex civilization later sprang. We can try to track this evolution via: the fossil and artifactual evidence for increases in hominin dietary breadth (the inclusion of a more diverse range of plant and animal foods); strontium and other isotopic evidence of individuals moving across more disparate landscapes; and lithic evidence for the selection of stone raw material resources in increasingly complex and specific ways and their movement across longer distances. Mobility patterns evolved from a probable chimpanzee-like loosely structured fission-fusion pattern within circumscribed territories, through stages of increasing territory size and movement organization as foraging (including both gathering and hunting) and technological behavioral complexity increased throughout the Plio-Pleistocene. The earliest evidence of each of these developments is found in Africa, even after hominins were also living in Eurasia. These transitions were longer and more gradual and multifaceted than previously thought. Clearly, more survey and excavation of fossiliferous and artifact-bearing deposits in Africa would do much to address these deficiencies in our knowledge of the evolution of nomadism in our early ancestors.
Inizan Marie-Louise, Roche Hélène. Hommages Jacques Tixier(1925-2018). In: Bulletin de la Société préhistorique française, tome 116, n°1, 2019. pp. 163-167.
Nadung'a 4 is one of the single carcass pachyderm sites recorded in East Africa during the Early Middle Pleistocene. The site has yielded an abundant lithic assemblage in close association with the ...partial carcass of an elephant. Conjoined pedological, geoarchaeological, spatial, technological and taphonomical analyses have been carried out to address the relationship between hominids and elephant. The resulting data are consistent with a non-fortuitous association between both categories of remains. The lithic artefacts do not match a classical Acheulean tool-kit, as would be expected for the time period ascribed to the site. The implications of the these features are discussed.
