A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain

Aranbaltza is an archaeological complex formed by at least three open-air sites. Between 2014 and 2015 a test excavation carried out in Aranbaltza III revealed the presence of a sand and clay sedimentary sequence formed in floodplain environments, within which six sedimentary units have been identified. This sequence was formed between 137±50 ka, and includes several archaeological horizons, attesting to the long-term presence of Neanderthal communities in this area. One of these horizons, corresponding with Unit 4, yielded two wooden tools. One of these tools is a beveled pointed tool that was shaped through a complex operational sequence involving branch shaping, bark peeling, twig removal, shaping, polishing, thermal exposition and chopping. A use-wear analysis of the tool shows it to have traces related with digging soil so it has been interpreted as representing a digging stick. This is the first time such a tool has been identified in a European Late Middle Palaeolithic context; it also represents one of the first well-preserved Middle Palaeolithic wooden tool found in southern Europe. This artefact represents one of the few examples available of wooden tool preservation for the European Palaeolithic, allowing us to further explore the role wooden technologies played in Neanderthal communities

Continuous versus single bolus enteral nutrition: comparison of energy metabolism in humans.

Continuous respiratory exchange measurements were performed on five women and five men for 1 h before and 6 h after the administration of a milkshake (53% carbohydrates, 30% lipid, and 17% protein energy) given either as a single bolus dose or continuously during 3 h using a nasogastric tube. The energy administered corresponded to 2.3 times the postabsorptive resting energy expenditure. Resting energy expenditure, respiratory quotient, plasma glucose, and insulin concentrations increased sooner and steeper, and plasma free fatty acids levels decreased earlier with the meal ingested as a single dose than with continuous administration. The magnitude of nutrient-induced thermogenesis was greater (P less than 0.01) with the single dose (means +/- SE, 10.0 +/- 0.6%) than with the continuous administration (8.1 +/- 0.5%). The overall (6 h) substrate balances were not significantly different between the two modes of administration. It is concluded that the mode of enteral nutrient administration influences the immediate thermogenic response as well as changes in respiratory quotient, glycemia, and insulinemia; however, the overall nutrient balance was not affected by the mode of enteral nutrient administration