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1.
J Hum Evol ; 89: 105-13, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25824673

RESUMO

Carbon and nitrogen stable isotopes in bone collagen can provide valuable information about the diet and habitat of mammal species. However, bone collagen degrades in normal circumstances very rapidly, and isotope analyses are therefore usually restricted to fossil material with a Late Pleistocene or Holocene age. The Middle Pleistocene site of Schöningen, dated to around 300,000 years ago, yielded bones and teeth with an exceptionally good state of collagen preservation. This allowed us to measure reliable biogenic carbon and nitrogen stable isotope ratios for different herbivorous taxa from the families Elephantidae, Rhinocerotidae, Equidae, Cervidae, and Bovidae. The results provide insights regarding the paleoenvironmental setting in which Middle Pleistocene hominins operated. The vegetation consumed by the herbivores from the famous spear horizon originates from open environments. During the climatic Reinsdorf Interglacial optimum, the landscape seems to have been relatively open as well, but certainly included parts that were forested. The results also indicate some niche partitioning; different herbivore species used different plant resources. For instance, the horses seem to have been predominantly browsers, while the straight-tusked elephants were feeding chiefly on grass.


Assuntos
Colágeno/química , Herbivoria , Mamíferos , Paleontologia , Animais , Osso e Ossos , Isótopos de Carbono/análise , Dieta , Alemanha , Isótopos de Nitrogênio/análise
2.
Food Chem ; 448: 139081, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38537551

RESUMO

Port is a famous sort of fortified wine, exclusively produced in the Douro region of Portugal. Among the various types of Port wines, the Tawny types with stated maturation ages of 10 or 20 years are among the higher quality and more expensive ones. Fraudulently producing those with a shorter maturation time than claimed, along with additions or treatments to mask this, would make production of those wines cheaper. Here, we present a method, based on Radiocarbon (14C) age determination of the ethanol and the sugar residue, to verify the maturation time of such Port wines. We successfully verified the method using single harvest year "Vintage" Port wines. We then analyzed a total of twenty 10- and 20-year-old Tawny Port wines, bought at various retail stores in the Netherlands. We found that seven of those had a significantly shorter maturation age than claimed on the label.

3.
Sci Rep ; 13(1): 16415, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-37775595

RESUMO

We report the discovery and analysis of new Mesolithic human remains-dated to ca. 10,200-9000 cal. BP-from Arma di Nasino in Liguria, northwestern Italy, an area rich in Upper Paleolithic and Neolithic attestations, but for which little information on Early Holocene occupation was available. The multi-proxy isotopic profile of the two individuals reveals that-despite the proximity of the site to the Mediterranean seashore and the use of shellfish as decorative elements in burials-the ecology of these foragers was based on the exploitation of high-altitude resources, presumably in the nearby western Alps. This constitutes the first direct evidence in northwestern Italy of a significant ecological shift towards higher altitudes following deglaciation, especially when compared to isotopic data of the Late Pleistocene hunter-gatherers from the nearby site of Arene Candide Cave, who exploited terrestrial resources nearer to the coast and at lower altitudes. While the biochemistry of Nasino's skeletal assemblage revealed new details on Early Holocene lifeways in the area, the osteobiography of one individual offers glimpses into the life experience of a specific female forager, depicting a scenario of early skeletal trauma, developmental disturbances, long-term impairments, and resilience amongst the last European hunter-gatherers.


Assuntos
Restos Mortais , Sepultamento , Humanos , Feminino , Itália
5.
ACS Sustain Chem Eng ; 5(11): 10864-10874, 2017 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-29142789

RESUMO

The one-step ethanolysis approach to upgrade lignin to monomeric aromatics using a CuMgAl mixed oxide catalyst is studied in detail. The influence of reaction temperature (200-420 °C) on the product distribution is investigated. At low temperature (200-250 °C), recondensation is dominant, while char-forming reactions become significant at high reaction temperature (>380 °C). At preferred intermediate temperatures (300-340 °C), char-forming reactions are effectively suppressed by alkylation and Guerbet and esterification reactions. This shifts the reaction toward depolymerization, explaining high monomeric aromatics yield. Carbon-14 dating analysis of the lignin residue revealed that a substantial amount of the carbon in the lignin residue originates from reactions of lignin with ethanol. Recycling tests show that the activity of the regenerated catalyst was strongly decreased due to a loss of basic sites due to hydrolysis of the MgO function and a loss of surface area due to spinel oxide formation of the Cu and Al components. The utility of this one-step approach for upgrading woody biomass was also demonstrated. An important observation is that conversion of the native lignin contained in the lignocellulosic matrix is much easier than the conversion of technical lignin.

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