La utilització de fangs de depuradora en un conreu de ray-grass

Peer Reviewe

Mitochondrial DNA genetic relationships at the ancient Neolithic site of Tell Halula

The extent of racemization of aspartic acid (Asp) -expressed as D/L ratio- has been used as a marker of biomolecular degradation in ancient remains. However, Asp racemization rate is highly variable, and depends on biochemical and geochemical factors. In this paper we aim to determine to which extent the fraction analyzed and the kind of sample used may influence the D/L Asp ratios. Other factors, such as burial site and sample preservation conditions, are also considered. D/L Asp ratios were obtained in 38 ancient human samples from 30 different individuals in which Real Time PCR quantification and amplification of short mtDNA fragments had been previously achieved. Four samples were taken from bones, 16 from whole teeth and 18 from dentine. In 7 cases whole tooth and dentine fractions from the same individual were analyzed. The samples belonged to 8 archaeological sites from Pre-pottery Neolithic B (PPNB), Cardial Neolithic and Chalcolithic time periods. Results show significant differences between the D/L Asp ratios obtained in dentine and whole tooth fractions from the same tooth and individual, as well as among dentine samples from the same archaeological site and among samples of the same age from different, though nearby, archaeological sites. Ancient DNA (aDNA) could be characterized in the majority of the samples, independently from their racemization values, which suggests that other factors, apart from the sample preservation stage, are more significantly affecting the racemization rate. A generalized use of the Asp racemization ratio as a threshold value for ancient DNA preservation needs to be questioned until further methodological standardization is considered

Neonatal Mortality, Young Calf Slaughter and Milk Production during the Early Neolithic of North Western Mediterranean

TheNorth-WesternMediterraneanwitnessed a rapid expansion of farmers and their livestock during the EarlyNeolithic period. Depending on the region, cattle played a more or less important role in these communities; however how these animalswere exploited for theirmilk is not clear. Herewe investigate calfmortality to determine indirectly whether cattle dairying was practised by Early Neolithic stock herders. Age-at-death (AtD) frequencies for calves from two sites: Trasano (Italy, Impressa culture: 7–6th millennium BC) and La Draga (Spain, Cardial culture: 6th millennium BC) were estimated from dental eruption and development stages, and measurements of un-fused post-cranial material. Adult age classes are well represented in the dental AtD frequencies and were interpreted as the result of the slaughter of prime beef and retired lactating females. For calves aged less than 12 months, there was no statistical difference in the AtD frequencies based on dental and post-cranial material indicating that the data is a good representation of the mortality patterns of calves, either natural or deliberate. At both sites there was a strong mortality peak at 3–6months in all AtD profiles. At La Draga, this peak was clearly differentiated from a peak at 0–1month, which can be interpreted neonatal mortality possible a consequence of the birthing season coinciding with the end of winter during more humid climatic conditions that at present. The deliberate slaughter peak around 3–6months is discussed, and we propose that stock herders controlled the mortality of infant classes, possibly in response to variable external environment pressures while maintaining animal productivity

Holocene snail shell isotopic record of millennial-scale hydrological conditions in western Mediterranean: data from Bauma del Serrat del Pont (NE Iberian Peninsula)

Land snail shells are a common component in Mediterranean Holocene archaeological deposits, providing the opportunity to explore their potential as source of information concerning human behaviour and palaeoclimatic conditions. Many well-preserved shells of the caenogastropod Pomatias elegans were recovered along the Holocene succession of Baumadel Serrat del Pont (BSP), in the Iberian Peninsula. Their oxygen (d18Os) and carbon (d13Cs) isotopic compositions were analysed and compared with that of modern shells of the samespecies collected intwo distinct areasnear the archaeological site.Modernshells fromSiteA(shady) and B (sunny) show distinctly different oxygen isotopic ratios possibly due to the effect of microenvironmental conditions (e.g. temperature and relative humidity). Carbon isotopes, by contrast, reveal similar values. Isotope mass balance suggests a prevalent contribution of vegetation (w70%), integrated with foreign carbonates (w30%) to d13Cs of modern snails. Earlyelate Holocene shells (w9e2.5 cal ka BP) have lower d18Os compared with modern counterparts, which is consistent with prevailing wetter conditions compared with present day. The d13Cs reveals distinct hydrological regimes, wet and dry conditions, from early to late Holocene respectively. In general, shell isotopic records from western and central Mediterranean regions suggest wetter conditions during the middle Holocene, with a possible reduction in humidity from w4 cal ka BP. The d18Os indicates a possible latitudinal difference in hydrological balance between Mediterranean and Atlantic Europe as inferred by previous studies of regional palaeoclimatic records. Carbon isotopes, by contrast, do not provide a clear climatic picture, probably due to the effect of distinct vegetation structure and composition. Comparisons with other environmental archives reinforce the concept of regional shell oxygen isotopic response to millennial-scale changes in hydrological condition over the western and central Mediterranean during the late Quaternary

¿Com aprofitar per a l'agricultura els fangs residuals derivats de la contaminació?

Una possible font d'obtenció d'adobs. Un exemple de rendibilització de residu