Researching in ancient engineering physical and chemical analysis in hidraulic roman mortars

Around ten years ago investigation of technical and material construction in Ancient Roma has advanced in favour to obtain positive results. This process has been directed to obtaining some dates based in chemical composition, also action and reaction of materials against meteorological assaults or post depositional displacements. Plenty of these dates should be interpreted as a result of deterioration and damage in concrete material made in one landscape with some kind of meteorological characteristics. Concrete mixture like calcium and gypsum mortars should be analysed in laboratory test programs, and not only with descriptions based in reference books of Strabo, Pliny the Elder or Vitruvius. Roman manufacture was determined by weather condition, landscape, natural resources and of course, economic situation of the owner. In any case we must research the work in every facts of construction. On the one hand, thanks to chemical techniques like X-ray diffraction and Optical microscopy, we could know the granular disposition of mixture. On the other hand if we develop physical and mechanical techniques like compressive strength, capillary absorption on contact or water behaviour, we could know the reactions in binder and aggregates against weather effects. However we must be capable of interpret these results. Last year many analyses developed in archaeological sites in Spain has contributed to obtain different point of view, so has provide new dates to manage one method to continue the investigation of roman mortars. If we developed chemical and physical analysis in roman mortars at the same time, and we are capable to interpret the construction and the resources used, we achieve to understand the process of construction, the date and also the way of restoration in future.

The late Miocene macroflora of the La Cerdaña Basin, Eastern Pirenees, Spain. Towards a Synthesis

The fossil plant-bearing beds of the Tortonian (late Miocene) intramontane basin of La Cerdanya (Eastern Pyrenees, Catalonia, Spain) have been investigated for more than a century, and 165 species from 12 outcrops have been described in previous publications. The sediments with rich plant fossil assemblages, which correspond to lacustrine diatomitic deposits, contain large numbers of plant remains, mainly leaf compressions and impressions. These assemblages are well preserved, a consequence of the rapid accumulation of plant remains in the sediments of the basin's ancient lake, and the often close proximity of its shores to wetland and upland vegetation. This paper provides a comprehensive taxonomic and nomenclatural review of the historic and new collections of late Miocene macroflora for the La Cerdanya Basin. Examination of the newer materials allowed emendments to be made to the diagnoses ofAbies saportana, Acer pyrenakum,Alnus occidentalis, Quercus hispanka and Tilia vidali provided by REROLLE for the basin at the end of the 19th century. In addition, 24 species of vascular plants are identified for the basin for the first time, including one horsetail, three conifers, 19 arboreal or bushy dicotyledonous angiosperms, and one monocotyledonous angiosperm. Indeed, this is the first time that Cedrela helkonia (UNGER) KNOBLOCH, Decodon sp„ Hedera cf multinervis KOLAKOVSKII, Mahonia cf pseudosimplex KVACEK & WALTHER, Smilax cf. aspera L. vm.fossilis and Ulmus cf. plurinervia UNGER have been recorded anywhere in the Iberian Peninsula. The La Cerdanya Basin plant assemblages of the late Miocene mainly consisted of conifers and deciduous broadleaved taxa of Arctotertiary origin; evergreen Palaeotropical elements were less well represented. This flora is similar to those recorded at coeval sites in northern Greece, northern Italy and central and eastern France. Within the Iberian Peninsula, the late Miocene macroflora reported for the nearby Seu d'Urgell Basin is the most similar.

Mechanical properties of adobe bricks in ancient constructions

A study of the mechanical properties of adobe bricks collected from houses and land dividing walls in Aveiro district, Portugal, representative of existing traditional constructions, was conducted. Cylindrical adobe specimens were subjected to simple compression and splitting tests. From these tests it was possible to evaluate the strength capacity, stiffness and deformation evolution for increasing loading. Correlations between the evaluated properties were determined, and the results obtained for houses and land dividing walls were compared. This study contributes for the characterization of adobes traditionally used in Aveiro district, and provides reference values that can be considered in rehabilitation processes

Adobe's Mechanical Characterization in Ancient Constructions: The Case of Aveiro's Region

Adobe is commonly found in Aveiro's ancient constructions. Preservation and rehabilitation of those constructions, some of them with architectural and historical interest, has been forgotten for many years. As a result, in Aveiro region, the majority of existing constructions in adobe is structurally weak, and, in several cases, they are in the threshold of ruin. Rehabilitation and/or strengthening urge. Despite some efforts has been made, a great difficulty for technicians working on the rehabilitation of these constructions relies on the lack of knowledge on adobe's mechanical behaviour. In fact, in order to properly describe the structural behaviour of those constructions, there is a need to investigate the mechanical behaviour of adobe. Hence, this paper is based on a study intended to characterise the behaviour of adobe brick units. Specimens were prepared from selected representative constructions of the Aveiro region. The prepared specimens were tested in order to evaluate their mechanical behaviour in compression and tension

Detection of 400-year-old Yersinia pestis DNA in human dental pulp: An approach to the diagnosis of ancient septicemia

Ancient septicemic plague epidemics were reported to have killed millions of people for 2 millenniums. However, confident diagnosis of ancient septicemia solely on the basis of historical clinical observations is not possible. The lack of suitable infected material has prevented direct demonstration of ancient septicemia; thus, the history of most infections such as plague remains hypothetical. The durability of dental pulp, together with its natural sterility, makes it a suitable material on which to base such research. We hypothesized that it would be a lasting refuge for Yersinia pestis, the plague agent. DNA extracts were made from the dental pulp of 12 unerupted teeth extracted from skeletons excavated from 16th and 18th century French graves of persons thought to have died of plague (“plague teeth”) and from 7 ancient negative control teeth. PCRs incorporating ancient DNA extracts and primers specific for the human β-globin gene demonstrated the absence of inhibitors in these preparations. The incorporation of primers specific for Y. pestis rpoB (the RNA polymerase β-subunit-encoding gene) and the recognized virulence-associated pla (the plasminogen activator-encoding gene) repeatedly yielded products that had a nucleotide sequence indistinguishable from that of modern day isolates of the bacterium. The specific pla sequence was obtained from 6 of 12 plague skeleton teeth but 0 of 7 negative controls (P < 0.034, Fisher exact test). A nucleic acid-based confirmation of ancient plague was achieved for historically identified victims, and we have confirmed the presence of the disease at the end of 16th century in France. Dental pulp is an attractive target in the quest to determine the etiology of septicemic illnesses detected in ancient corpses. Molecular techniques could be applied to this material to resolve historical outbreaks.

Histone underacetylation is an ancient component of mammalian X chromosome inactivation

Underacetylation of histone H4 is thought to be involved in the molecular mechanism of mammalian X chromosome inactivation, which is an important model system for large-scale genetic control in eukaryotes. However, it has not been established whether histone underacetylation plays a critical role in the multistep inactivation pathway. Here we demonstrate differential histone H4 acetylation between the X chromosomes of a female marsupial, Macropus eugenii. Histone underacetylation is the only molecular aspect of X inactivation known to be shared by marsupial and eutherian mammals. Its strong evolutionary conservation implies that, unlike DNA methylation, histone underacetylation was a feature of dosage compensation in a common mammalian ancestor, and is therefore likely to play a central role in X chromosome inactivation in all mammals.

Nationalism in the Troubled Triangle. Cyprus, Greece and Turkey

Peer reviewed

An ancient family of human endogenous retroviruses encodes a functional homolog of the HIV-1 Rev protein

The human endogenous retrovirus K (HERV-K) family of endogenous retroviruses consists of ≈50 proviral copies per haploid human genome. Herein, the HERV-Ks are shown to encode a sequence-specific nuclear RNA export factor, termed K-Rev, that is functionally analogous to the HIV-1 Rev protein. Like HIV-1 Rev, K-Rev binds to both the Crm1 nuclear export factor and to a cis-acting viral RNA target to activate nuclear export of unspliced RNAs. Surprisingly, this HERV-K RNA sequence, which is encoded within the HERV-K long terminal repeat, is also recognized by HIV-1 Rev. These data provide surprising evidence for an evolutionary link between HIV-1 and a group of endogenous retroviruses that first entered the human genome ≈30 million years ago.

Carbonic anhydrase is an ancient enzyme widespread in prokaryotes

Carbonic anhydrases catalyze the reversible hydration of CO2 and are ubiquitous in highly evolved eukaryotes. The recent identification of a third class of carbonic anhydrase (γ class) in a methanoarchaeon and our present finding that the β class also extends into thermophilic species from the Archaea domain led us to initiate a systematic search for these enzymes in metabolically and phylogenetically diverse prokaryotes. Here we show that carbonic anhydrase is widespread in the Archaea and Bacteria domains, and is an ancient enzyme. The occurrence in chemolithoautotrophic species occupying deep branches of the universal phylogenetic tree suggests a role for this enzyme in the proposed autotrophic origin of life. The presence of the β and γ classes in metabolically diverse species spanning the Archaea and Bacteria domains demonstrates that carbonic anhydrases have a far more extensive and fundamental role in prokaryotic biology than previously recognized.

Ancient mtDNA sequences in the human nuclear genome: A potential source of errors in identifying pathogenic mutations

Nuclear-localized mtDNA pseudogenes might explain a recent report describing a heteroplasmic mtDNA molecule containing five linked missense mutations dispersed over the contiguous mtDNA CO1 and CO2 genes in Alzheimer’s disease (AD) patients. To test this hypothesis, we have used the PCR primers utilized in the original report to amplify CO1 and CO2 sequences from two independent ρ° (mtDNA-less) cell lines. CO1 and CO2 sequences amplified from both of the ρ° cells, demonstrating that these sequences are also present in the human nuclear DNA. The nuclear pseudogene CO1 and CO2 sequences were then tested for each of the five “AD” missense mutations by restriction endonuclease site variant assays. All five mutations were found in the nuclear CO1 and CO2 PCR products from ρ° cells, but none were found in the PCR products obtained from cells with normal mtDNA. Moreover, when the overlapping nuclear CO1 and CO2 PCR products were cloned and sequenced, all five missense mutations were found, as well as a linked synonymous mutation. Unlike the findings in the original report, an additional 32 base substitutions were found, including two in adjacent tRNAs and a two base pair deletion in the CO2 gene. Phylogenetic analysis of the nuclear CO1 and CO2 sequences revealed that they diverged from modern human mtDNAs early in hominid evolution about 770,000 years before present. These data would be consistent with the interpretation that the missense mutations proposed to cause AD may be the product of ancient mtDNA variants preserved as nuclear pseudogenes.

Intron positions correlate with module boundaries in ancient proteins

We analyze the three-dimensional structure of proteins by a computer program that finds regions of sequence that contain module boundaries, defining a module as a segment of polypeptide chain bounded in space by a specific given distance. The program defines a set of “linker regions” that have the property that if an intron were to be placed into each linker region, the protein would be dissected into a set of modules all less than the specified diameter. We test a set of 32 proteins, all of ancient origin, and a corresponding set of 570 intron positions, to ask if there is a statistically significant excess of intron positions within the linker regions. For 28-Å modules, a standard size used historically, we find such an excess, with P < 0.003. This correlation is neither due to a compositional or sequence bias in the linker regions nor to a surface bias in intron positions. Furthermore, a subset of 20 introns, which can be putatively identified as old, lies even more explicitly within the linker regions, with P < 0.0003. Thus, there is a strong correlation between intron positions and three-dimensional structural elements of ancient proteins as expected by the introns-early approach. We then study a range of module diameters and show that, as the diameter varies, significant peaks of correlation appear for module diameters centered at 21.7, 27.6, and 32.9 Å. These preferred module diameters roughly correspond to predicted exon sizes of 15, 22, and 30 residues. Thus, there are significant correlations between introns, modules, and a quantized pattern of the lengths of polypeptide chains, which is the prediction of the “Exon Theory of Genes.”

Fish and mammals in the economy of an ancient Peruvian kingdom

Fish and mammal bones from the coastal site of Cerro Azul, Peru shed light on economic specialization just before the Inca conquest of A.D. 1470. The site devoted itself to procuring anchovies and sardines in quantity for shipment to agricultural communities. These small fish were dried, stored, and eventually transported inland via caravans of pack llamas. Cerro Azul itself did not raise llamas but obtained charqui (or dried meat) as well as occasional whole adult animals from the caravans. Guinea pigs were locally raised. Some 20 species of larger fish were caught by using nets; the more prestigious varieties of these show up mainly in residential compounds occupied by elite families.

Isoprenoid biosynthesis: The evolution of two ancient and distinct pathways across genomes

Isopentenyl diphosphate (IPP) is the central intermediate in the biosynthesis of isoprenoids, the most ancient and diverse class of natural products. Two distinct routes of IPP biosynthesis occur in nature: the mevalonate pathway and the recently discovered deoxyxylulose 5-phosphate (DXP) pathway. The evolutionary history of the enzymes involved in both routes and the phylogenetic distribution of their genes across genomes suggest that the mevalonate pathway is germane to archaebacteria, that the DXP pathway is germane to eubacteria, and that eukaryotes have inherited their genes for IPP biosynthesis from prokaryotes. The occurrence of genes specific to the DXP pathway is restricted to plastid-bearing eukaryotes, indicating that these genes were acquired from the cyanobacterial ancestor of plastids. However, the individual phylogenies of these genes, with only one exception, do not provide evidence for a specific affinity between the plant genes and their cyanobacterial homologues. The results suggest that lateral gene transfer between eubacteria subsequent to the origin of plastids has played a major role in the evolution of this pathway.