Characterization and causes of the building stone decay at the Artemis temple, Brauron, E. Attica, Greece

Στην περιοχή της Βραβρώνας ή Βραώνας στην Α. Αττική σε μικρή απόσταση από τον ομώνυμο κόλπο, δίπλα στις όχθες του Ερασινού ποταμού υπάρχει ο ναός της Αρτέμιδας του 415 π.Χ. Οι δομικοί λίθοι που χρησιμοποιήθηκαν για την κατασκευή του ναού είναι ψαμμίτες και προέρχονται από Νεογενείς ιζηματογενείς αποθέσεις. Ιχνη από τα αρχαία λατομεία σε απόσταση 500μ. από τον ναό είναι ακόμη ορατά. Τα ερείπια του ναού είχαν μείνει θαμένα στην λάσπη του δέλτα του Ερασινού που σχημάτιζε σύστημα ελών και /αμνόθάλασσας, για δεκάδες αιώνων. Κατά τις εργασίες την αναστήλωσης, εκτός από τους θαμένους λίθους χρησιμοποιήθηκε και νέο υλικό από τους σχηματισμούς των αρχαίων λατομείων. Τα αναστηλωμένα τμήματα εμφανίζουν έντονα σημάδια διάβρωσης. Ο σκοπός αυτής της εργασίας είναι η μελέτη των μορφών και των αιτίων της διάβρωσης. Οι διαβρωσιγενείς μορφές οφείλονται σε ενδογενείς και περιβαλλοντολογικούς παράγοντες. Οι κυριότεροι ενδογενείς παράγοντες είναι α) το υψηλό πορώδες, και η κατανομή των πόρων, β) το ασβεστιτικό συνδετικό υλικό του λίθου γ) η ορυκτολογική σύσταση και κυρίως η παρουσία διασταλτών αργιλικών ορυκτών. Οι κυριότεροι περιβαλλοντολογικοί παράγοντες διάβρωσης που συντελούν στην ανακρυστάλλωση του ασβεστίτη και στη κρυστάλλωση αλάτων, είναι α) η παραμονή των δομικών λίθων ενταφιασμένων σε υφάλμυρο περιβάλλον, για αιώνες, β) τα συχνά πλημμυρικά επεισόδια και η πιθανή μόλυνση του ποταμού Ερασινού, γ) η επίδραση της όξινης βροχής και των θαλάσσιων ανέμων και δ) η βιοδιάβρωση. Τα συμπεράσματα αυτής της μελέτης μπορεί να έχουν εφαρμογή και σε άλλα ιστορικά μνημεία σε αντίστοιχα περιβάλλοντα.At Brauron (Vraona or Vravrona) area, E. Attica, near the Brauron bay, by the Erasinos river there is an ancient monument of 415 B.C., dedicated to Artemis. The building material used for the construction of the monument is sandstone originated from Neogene sedimentary deposits. The ancient quarries are located 500m away from the monument and traces of quarring are still visible. Monument ruins had been buried under the mud load curried by Erasinos river for many centuries. During the restoration works of the Temple of Artemis besides the stone found in situ, new material provided by the same formation was as well, used. The restored monument stones display intensive deterioration. The purpose of this paper is to study of the decay forms and investigate the decay causes of the building stone in the monument. The decay forms result from intrinsic (endogenic) and environmental factors. The main endogenic factors of decay of the sandstone used as building material, are: a) the high porosity, and the pore size distribution, b) the calcite cement of the stone c) the mineralogical composition, especially the presence of swelling clay minerals. The main environmental factors of decay that result to the calcite and salt crystallization are a) the burial of the ancient building stones, in the brackish water-mud, for centuries b) the frequent floods and possible pollution of the nearby Erasinos river c) the acid rain and aerosol attack d) the bioteterioration. The conclusions of this case study may have application on other monuments of historical interest, in similar environmen

Once-yearly zoledronic acid in the prevention of osteoporotic bone fractures in postmenopausal women

Zoledronic acid is a nitrogen-containing, third-generation bisphosphonate that has recently been approved for the treatment of postmenopausal osteoporosis as an annual intravenous infusion. Zoledronic acid is an antiresorptive agent which has a high affinity for mineralized bone and especially for sites of high bone turnover. Zoledronic acid is excreted by the kidney without further metabolism. Zoledronic acid administered as a 5 mg intravenous infusion annually increases bone mineral density in the lumbar spine and femoral neck by 6.7% and 5.1% respectively and reduces the incidence of new vertebral and hip fractures by 70% and 41% respectively in postmenopausal women with osteoporosis. Most common side effects are post-dose fever, flu-like symptoms, myalgia, arthralgia, and headache which usually occur in the first 3 days after infusion and are self-limited. Rare adverse effects include renal dysfunction, hypocalcemia, atrial fibrillation, and osteonecrosis of the jaw

Incidence of Insomnia in OSA patients and its correlations with parameters of polysomnography

Background/Aims: Prevalence of insomnia in obstructive sleep apnoea (OSA) patients has been estimated in many studies and has been found to be a frequent symptom (38% in a recent review 1).Our study aims to estimate the incidence of insomnia in Greek patients presenting to a public hospital sleep clinic, and correlate it with the severity of OSA and parameters of polysomnography (PSG). Methods: 100 patients who visited the sleep unit of the General Hospital ‘Evangelismos’ completed the Athens Insomnia Scale (AIS) and underwent a polysomnographic study. 56% were men, with mean age 54,7±12,5 years and BMI 31,5±6,2. Results: 70% of patients had insomnia. Insomnia (AIS≥6) and OSA (AHI≥5) were coexistent in 71,4 %. There was no correlation between insomnia and severity of OSA. A strong positive correlation was found/evident between difficulty in initiating sleep and number of hypopneas (r: 0,20 p:0,049), diminished functioning during the day and leg movements (r:0,21 p:0,050) and between daytime sleepiness and wake after sleep onset (WASO) (r:0,2 p:0,038). A negative correlation was found between overnight awakenings and sleep efficiency (r: -0,23 p: 0,021). Also, negative correlation was found between early morning awakening and minimum SpO2 (r=0.27, p=0,021), and between insufficient duration of sleep (r:-0,22 p: 0,021) and minimum SpO2. Conclusions: We found a high incidence of insomnia in patients with OSA, which does not correlate with severity of OSA. Contrary to many other studies, insomnia was not more common in women. More studies are required to clarify the significance of the positive correlation between insomnia and number of hypopneas and minimum SpO2

PETROLOGICAL CHARACTERS OF THE EARLY CRETACEOUS BOEOTHIAN FLYSCH, (CENTRAL GREECE)

This paper is aimed to study the petrographic characters of the Boeothian Flysch, an Early Cretaceous turbidite deposit which marks the boundary between the External/Internal Hellenides in central-southern Greece, in order to define a preliminary palaeogeographic reconstruction of the Pindos segment of the Alpine Tethys. The Boeothian Flysch is mainly made up by basal conglomerates and arenaceous-pelitic lithofacies, locally interlayered with Calpionellid micrite limestones. This formation is here supposed to belong to the Early Cretaceous flysch family, which marks the contact between the internal and external areas along all the western and central European Alpine Chains for more than 7,000 km, from the Gibraltar Arc to the Balkans via the Calabria-Peloritani Arc. Provenance of these flysch is commonly connected to internal areas, mainly made up by Hercynian crystalline basements and, locally, by ophiolitic complexes. The petrographic data obtained from representative sandstones of the Boeothian Flysch suggest a provenance from internal sources, formed by a Jurassic carbonate platform, metamorphic basements and by ophiolitic complexes, which can be identified with the Pelagonian Terranes (Auct.). An Early Cretaceous uplift and rejuvenation processes, probably related to the late Cretaceous tectogenesis, widely recorded in almost all the central-western Alpine Tethis, affected these internal domains with consequent production of abundant detrital supply in the innermost sector of the Pindos Ocean, whose external margin was bounded by the Parnassos microcontinent

As-Soon-As-Possible Top-k Query Processing in P2P Systems

International audienceTop-k query processing techniques provide two main advantages for unstructured peer-to-peer (P2P) systems. First they avoid overwhelming users with too many results. Second they reduce significantly network resources consumption. However, existing approaches suffer from long waiting times. This is because top-k results are returned only when all queried peers have finished processing the query. As a result, query response time is dominated by the slowest queried peer. In this paper, we address this users' waiting time problem. For this, we revisit top-k query processing in P2P systems by introducing two novel notions in addition to response time: the stabilization time and the cumulative quality gap. Using these notions, we formally define the as-soonas-possible (ASAP) top-k processing problem. Then, we propose a family of algorithms called ASAP to deal with this problem. We validate our solution through implementation and extensive experimentation. The results show that ASAP significantly outperforms baseline algorithms by returning final top-k result to users in much better times

Understanding children’s constructions of meanings about other children: implications for inclusiveeducation

This paper explores the factors that influence the way children construct meanings about other children, and especially those who seem to experience marginalisation, within school contexts. The research involved an ethnographic study in a primary school in Cyprus over a period of 5 months. Qualitative methods were used, particularly participant observations and interviews with children. Interpretation of the data suggests that children's perceptions about other children, and especially those who come to experience marginalisation, are influenced by the following factors: other children and the interactions between them; adults’ way of behaving in the school; the existing structures within the school; and the cultures of the school and the wider educational context. Even though the most powerful factor was viewed to be the adults’ influence, it was rather the interweaving between different factors that seemed to lead to the creation of particular meanings for other children. In the end, it is argued that children's voices should be seen as an essential element within the process of developing inclusive practices.<br/

PIMMS43 is required for malaria parasite immune evasion and sporogonic development in the mosquito vector.

After being ingested by a female Anopheles mosquito during a bloodmeal on an infected host, and before they can reach the mosquito salivary glands to be transmitted to a new host, Plasmodium parasites must establish an infection of the mosquito midgut in the form of oocysts. To achieve this, they must first survive a series of robust innate immune responses that take place prior to, during, and immediately after ookinete traversal of the midgut epithelium. Understanding how parasites may evade these responses could highlight new ways to block malaria transmission. We show that an ookinete and sporozoite surface protein designated as PIMMS43 (Plasmodium Infection of the Mosquito Midgut Screen 43) is required for parasite evasion of the Anopheles coluzzii complement-like response. Disruption of PIMMS43 in the rodent malaria parasite Plasmodium berghei triggers robust complement activation and ookinete elimination upon mosquito midgut traversal. Silencing components of the complement-like system through RNAi largely restores ookinete-to-oocyst transition but oocysts remain small in size and produce a very small number of sporozoites that additionally are not infectious, indicating that PIMMS43 is also essential for sporogonic development in the oocyst. Antibodies that bind PIMMS43 interfere with parasite immune evasion when ingested with the infectious blood meal and significantly reduce the prevalence and intensity of infection. PIMMS43 genetic structure across African Plasmodium falciparum populations indicates allelic adaptation to sympatric vector populations. These data add to our understanding of mosquito-parasite interactions and identify PIMMS43 as a target of malaria transmission blocking

Microbial adaptation to venom is common in snakes and spiders

Animal venoms are considered sterile sources of antimicrobial compounds with strong membrane disrupting activity against multi-drug resistant bacteria. However, bite wound infections are common in developing nations. Investigating the oral and venom microbiome of five snake and two spider species, we evidence viable microorganisms potentially unique to venom for black-necked spitting cobras (Naja nigricollis). Among these are two novel sequence types of Enterococcus faecalis misidentified by commonly used clinical biochemistry procedures as Staphylococcus; the genome sequence data of venom-specific isolates feature an additional 45 genes, at least 11 of which improve membrane integrity. Our findings challenge the dogma of venom sterility and indicate an increased primary infection risk in the clinical management of venomous animal bite wounds