Y-SNPs Do Not Indicate Hybridisation between European Aurochs and Domestic Cattle

Background: Previous genetic studies of modern and ancient mitochondrial DNA have confirmed the Near Eastern origin of early European domestic cattle. However, these studies were not able to test whether hybridisation with male aurochs occurred post-domestication. To address this issue, Götherström and colleagues (2005) investigated the frequencies of two Y-chromosomal haplotypes in extant bulls. They found a significant influence of wild aurochs males on domestic populations thus challenging the common view on early domestication and Neolithic stock-rearing. To test their hypothesis, we applied these Y-markers on Neolithic bone specimens from various European archaeological sites. Methods and Findings: Here, we have analysed the ancient DNA of 59 Neolithic skeletal samples. After initial molecular sexing, two segregating Y-SNPs were identified in 13 bulls. Strikingly, our results do not support the hypothesis that these markers distinguish European aurochs from domesticated cattle. Conclusions: The model of a rapid introduction of domestic cattle into Central Europe without significant crossbreeding with local wild cattle remains unchallenged

The Enigmatic Origin of Bovine mtDNA Haplogroup R: Sporadic Interbreeding or an Independent Event of Bos primigenius Domestication in Italy?

BACKGROUND: When domestic taurine cattle diffused from the Fertile Crescent, local wild aurochsen (Bos primigenius) were still numerous. Moreover, aurochsen and introduced cattle often coexisted for millennia, thus providing potential conditions not only for spontaneous interbreeding, but also for pastoralists to create secondary domestication centers involving local aurochs populations. Recent mitochondrial genomes analyses revealed that not all modern taurine mtDNAs belong to the shallow macro-haplogroup T of Near Eastern origin, as demonstrated by the detection of three branches (P, Q and R) radiating prior to the T node in the bovine phylogeny. These uncommon haplogroups represent excellent tools to evaluate if sporadic interbreeding or even additional events of cattle domestication occurred. METHODOLOGY: The survey of the mitochondrial DNA (mtDNA) control-region variation of 1,747 bovine samples (1,128 new and 619 from previous studies) belonging to 37 European breeds allowed the identification of 16 novel non-T mtDNAs, which after complete genome sequencing were confirmed as members of haplogroups Q and R. These mtDNAs were then integrated in a phylogenetic tree encompassing all available P, Q and R complete mtDNA sequences. CONCLUSIONS: Phylogenetic analyses of 28 mitochondrial genomes belonging to haplogroups P (N = 2), Q (N = 16) and R (N = 10) together with an extensive survey of all previously published mtDNA datasets revealed major similarities between haplogroups Q and T. Therefore, Q most likely represents an additional minor lineage domesticated in the Near East together with the founders of the T subhaplogroups. Whereas, haplogroup R is found, at least for the moment, only in Italy and nowhere else, either in modern or ancient samples, thus supporting an origin from European aurochsen. Haplogroup R could have been acquired through sporadic interbreeding of wild and domestic animals, but our data do not rule out the possibility of a local and secondary event of B. primigenius domestication in Italy

Making a Significant Place: Excavations at the Late Mesolithic Site of Langley’s Lane, Midsomer Norton, Bath and North-East Somerset

Excavations at the site of Langley’s Lane, Bath and North-East Somerset, have revealed an important sequence of Late Mesolithic activity focused around an active tufa spring. The sequence of activity starts off as an aurochs kill and primary butchery site. Culturally appropriate depositional practices occur through the placement of a selection of bone in the wetland of the spring and the digging of pits around the spring margins. The spring at Langley’s Lane continued to be visited and more animal bone and lithic material was placed in the wetland. Finally, visits to the site involved yet more formalized activity in the form of pit digging and the creation of a stone surface. Activities such as these are difficult to locate in the archaeological record and Mesolithic ritual activity rare, making this a site of some significance to studies of Mesolithic NW Europe

De Oeros: het spoor terug

"In De oeros ontrafelt Cis van Vuure het spoor terug naar de oorsprong van de in 1627 uitgestorven oeros. Die kwam oorspronkelijk uit Zuidoost-Azië, zijn leefgebied strekte zich uit van Thailand tot West-Europa. De laatste oeros leefde in het gebied rondom de Centraal-Poolse plaats Jaktorów. Van Vuure speurde naar het spoor van de oeros via historische bronnen als tekeningen, boeken en runenverzen en bezoeken aan runderfokkerijen van onder meer Spaanse vechtstieren. De oeros is niet alleen een historisch interessante zoektocht, omdat Van Vuure in twee conclusies direct aansluit bij de huidige natuurdiscussie. De Heck-runderen die nu in de Nederlandse natuur grazen werden in de jaren 1920 door de gebroeders Heck gefokt naar het toen heersende beeld van de oeros. Volgens Van Vuure klopt daar echter weinig van. Volgens hem leek de oeros meer op een Spaans vechtrund. De stier van de oeros had een schofthoogte van 170 à 180 centimeter, de koe 150. Dat is veel groter dan de Heck-runderen. Volgens Van Vuure leefde de oeros in een landschap met dichte bossen, verschillende soorten moerassen en hoogvenen, vooral in de rivierdalen, kwelders en zeggemoerassen. Van Vuure baseert zich hiervoor onder meer op een runenvers uit de negende eeuw, waarin de os de bijnaam 'moerasloper' krijgt, op overleveringen dat oerossen in Egypte langs de Nijl leefden. Dat opent weer nieuwe perspectieven voor de discussie die ecoloog Frans Vera in 2000 opende over hoe het Nederlandse landschap er in vroeger tijden uit heeft gezien, en naar welk evenbeeld we de huidige natuur moeten vormen." (Recensie door Martin Woestenburg, 2003. http://www.woestenburg.nl/

Investigation of the tensile behavior of treated flax fibre bio-composites at ambient humidity

The high specific strength and stiffness and excellent damping behavior promote the use of flax fibre composites in the construction sector. However, the limited compatibility between raw flax fibres and bio-epoxy resin often leads to composites with mechanical properties well below their theoretical capacities. Moreover, the incomplete understanding of the intrinsic non-linear mechanical behavior of flax fibre composites forces the application of larger safety factors. In this study, three chemical treatments are applied to improve the interphase properties and gain further insight in the longitudinal tensile behavior of flax fibre bio-epoxy composites. Both alkali and APS treatment result in a threefold improvement in the transverse flexural strength to ∼30MPa. Both treatments additionally shift the weakest link to the elementary fibre interphase strength. Analysis of the longitudinal tensile stress-strain curves of UD flax fibre composites results in a tri-linear shape that is preserved after treatment

The potential and pitfalls of de-extinction

‘De-extinction’ is the nascent discipline that aims to one day literally revive now-extinct species from the dead. Although we have yet to see any successful attempts to truly resurrect an extinct species, several technologies are now in place that might one day provide a plausible solution. Thus, the area is receiving increased attention from both scientists and the general public. However, how far does present technology place us from the ultimate goal? We address the state of the art of several prominent de-extinction methods: back-breeding, cloning, synthetic genomics and genome editing, and discuss some of the major outstanding challenges for each. We also discuss some of the wider challenges facing de-extinction, including both what might constitute the definition of success and what might be needed to successfully take a recreated animal and confer on it the ability to establish itself back in the wild

Interfaces in Natural Fibre Composites: Effect of Surface Energy and Physical Adhesion

An integrated physical-chemical-mechanical approach was used to study the effect of adhesion on the mechanical strength of composites reinforced with bamboo and coir fibres, and three thermoplastic matrices (Polypropylene (PP), maleic anhydride grafted polypropylene (MAPP), and polyvinylidene fluoride (PVDF). Surface chemical analysis was conducted by X-ray photoelectron spectroscopy, XPS. Surface physical-chemistry was studied by determining surface energy components of fibres and matrices, by performing contact angle measurements with various known test fluids and employing a 3-component model for surface energy. Work of physical adhesion was calculated. Transverse 3-point bending tests on uni-directional composites were conducted to study interface strength and composite strength was determined by longitudinal flexural tests. Results show that increase in physical adhesion can explain the improved interface and longitudinal strength in bamboo-PVDF and coir-PVDF composites, as compared to the PP composites. For MAPP, no increase in physical adhesion is predicted, but particularly for coir a strong increase in mechanical interface strength and consequently an increase in longitudinal strength was observed, which may be attributed to a chemical adhesion mechanism.status: Published onlin