Does the osteon morphology depend on the body mass? A scaling study on macroscopic and histomorphometric differences between cow ( Bos taurus ) and sheep ( Ovis aries )

AbstractThe structure and geometry of bone depend on many biological and environmental factors. These factors affect the bone tissue's microstructure differently, and their interaction has not yet been fully elucidated. Our research investigated the effect of body mass on the macro- and microstructure of the compact bone. Therefore we analyzed the humerus and femur bones from females of 11 cows and 11 sheep at the age of 4–10 years. Both species have very similar dietary and locomotion patterns, but their body size and weight are very different. Within macroscopical analyzes of bones were observed ascending order of robustness index and bone diaphysis index. In both animals, plexiform and irregular Haversian bone tissues were identified in humerus and femur. Conversely, the dense Haversian tissue present only in cow above all in the femur. The most considerable interspecific osteonal difference between sheep and cow was in the osteon density, whose average value is 37% higher in the cow. The osteons of sheep humerus are almost circular, and osteons of cow femur are more elliptical. Within both species, the femoral osteons are elliptical than those of humerus. Despite the cow weighing more than 10 times the sheep, the measurements of osteons and Haversian canals, are very similar (the values of the ratio cow/sheep for these types are comprised from 1.04 to 1.86). Our findings indicate that the body mass does not affect the size of bone microstructure, probably more sensitive to other factors as a lifestyle and locomotor ability

Sperm whales in the Neolithic Mediterranean: a tooth from the sanctuary of Monte d'Accoddi (Sardinia, Italy)

The exceptional find of the tooth of a sperm whale (Physeter macrocephalus) at Monte d'Accoddi adds to the documentation on the possible presence, and exploitation by humans, of cetaceans in the prehistoric Mediterranean. The dating (3638–3378 BC) appears to make it the oldest cetacean find in Sardinia

Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an accelerated laboratory stress test procedure. Liquid chromatographic separation of the three possible isomers on a C18 stationary phase was used for identification of 4-HBA in all samples. Finally, this degradation product could be assigned to a monomer of the tested membrane. In conjunction with gel permeation chromatography (GPC) analysis a degradation mechanism for 4-HBA could be proposed.Eine der Hauptursachen für den Abbau von Polymer-Elektrolyt-Membranen (PEM) während des Betriebes in Brennstoffzellen ist die Bildung von Hydroxyl-Radikalen. Die Radikale greifen das Polymer an, was zu Kettenspaltung und folglich zur Zersetzung der Membran führt. Die vorliegende Arbeit untersucht Zersetzungsprodukte von sulfonierten aromatischen Kohlenwasserstoff-Membranen auf Basis einer Produktwasseranalytik. Abbauprodukte des untersuchten Membran-Typs sowie deren Nutzung für diagnostische Zwecke über eine Produktwasseranalytik wurden bisher noch nicht untersucht. Diese Arbeit zeigt das Potential der Festphasenextraktion und der Flüssig-keitschromatographie Tandem-Massenspektrometrie (SPE-LC-MS/MS) zur Anreicherung, Trennung, Charakterisierung, Identifizierung und Quantifizierung von Membranabbauprodukten im Produktwasser von Brennstoffzellen. Zu diesem Zweck wurden mehrere polare aromatische Kohlenwasserstoffe mit verschiedenen funktionellen Gruppen als Modellverbindungen für die Entwicklung zuverlässiger Anreicherungs-, Trennungs- und Nachweismethoden verwendet. Die Untersuchungen dieser Arbeit haben gezeigt, dass Mixed-Mode-Materialien mit schwachen Anionenaustauscher- und Umkehrphaseneigenschaften zur reproduzierbaren Aufkonzentrierung von Molekülen und Ionen aus dem Produktwasser geeignet sind. Die chromatografische Trennung für verschiedene polare aromatische Kohlenwasserstoffe konnte mittels Phasen optimierter Flüssigkeitschromatographie unter erstmaliger Anwendung eines Lösungsmittel-gradienten als auch auf einer C18-Phase erreicht werden. Die empfindliche und selektive Detektion von Degradationsprodukten im Produktwasser mittels Tandem-Massenspektrometrie konnte erfolgreich anhand von Modellsubstanzen demonstriert werden. Mit der Hybrid-Massenspektrometrie (Q Trap) konnte die Hydroxy-benzoesäure (HBA) im Produktwasser identifiziert und bestätigt werden. Weiterführende Untersuchungen haben gezeigt, dass HBA durch den Abbau der Polymer-Elektrolyt-Membran in einem oxidativem Stresstest mit Hydroxylradikalen gebildet wird. Durch eine flüssigchromatografische Trennung von drei möglichen Strukturisomeren der HBA auf einer C18-Phase konnte die 4-HBA in allen Proben identiziert werden. Die 4-HBA konnte weiterhin einem Monomer der getesteten Membran zugeordnet werden. In Verbindung mit der Gelpermeationschromatografie (GPC) Analyse konnte ein Degradationsmechanismus für die Bildung von 4-HBA vorgeschlagen werden

An Adaptive Behaviour-Based Strategy for SARs interacting with Older Adults with MCI during a Serious Game Scenario

The monotonous nature of repetitive cognitive training may cause losing interest in it and dropping out by older adults. This study introduces an adaptive technique that enables a Socially Assistive Robot (SAR) to select the most appropriate actions to maintain the engagement level of older adults while they play the serious game in cognitive training. The goal is to develop an adaptation strategy for changing the robot's behaviour that uses reinforcement learning to encourage the user to remain engaged. A reinforcement learning algorithm was implemented to determine the most effective adaptation strategy for the robot's actions, encompassing verbal and nonverbal interactions. The simulation results demonstrate that the learning algorithm achieved convergence and offers promising evidence to validate the strategy's effectiveness

The EU sovereign debt crisis: potential effects on EU banking systems and policy options

This paper aims at investigating some of the critical issues highlighted by the sovereign debt crisis in European Union Member States. The goal is twofold: 1) Quantify, via a development of the SYMBOL model here firstly presented, the impact in terms of higher risk for the EU banking systems of haircuts of sovereign debts of some EU MS, which have been particularly touched by the sovereign crisis; 2) evaluate and compare the policy options which have been adopted to address the issue. In particular the analysis compares the measures within the Basel III Accord, which increases the quality and quantity of capital that banks should set aside to cover from unexpected losses, with the agreement on bank recapitalisation and funding reached by the European Council in October 2011, which responded to the urgent consequences of the sovereign bonds crisis in the EU. The analysis is performed on 65 of the large EU banking groups identified by the European Banking Authority, via a futher development of the SYMBOL model that allows estimating the banks PD without Monte Carlo simulations. Results show that the haircuts on sovereign debts of EU MS in crisis would heavily worsen the stability of their banking systems but could also sometimes affect financial stability of other EU countries. We also show that the creation of a temporary capital buffer in the form of a capital target, necessitated by the exceptional circumstances prevailing in some EU MS, represent a step forward to Basel III rules.JRC.G.1-Scientific Support to Financial Analysi

FLOW INHOMOGENEITIES IN A REALISTIC AERONAUTICAL GAS-TURBINE COMBUSTOR: FORMATION, EVOLUTION AND INDIRECT NOISE

Indirect noise generated by the acceleration of combustion inhomogeneities is an important aspect in the design of aeroengines because of its impact on the overall noise emitted by an aircraft and the possible contribution to combustion instabilities. In this study, a realistic rich-quench-lean combustor is numerically investigated, with the objective of quantitatively analyzing the formation and evolution of flow inhomogeneities and determine the level of indirect combustion noise in the nozzle guide vane (NGV). Both entropy and compositional noise are calculated in this work. A high-fidelity numerical simulation of the combustion chamber, based on the Large-Eddy Simulation (LES) approach with the Conditional Moment Closure (CMC) combustion model, is performed. The contribution of the different air streams to the formation of flow inhomogeneity is identified and separated through seven dedicated passive scalars. This pins down the individual contributions of the air streams to combustion inhomogeneity at the combustor’s exit. LES-CMC results are then used to determine the acoustic sources to feed an NGV aeroacoustic model, which outputs the noise generated by entropy and compositional inhomogeneities. Results show that non-negligible fluctuations of temperature and composition reach the combustor’s exit. Combustion inhomogeneities originate both from finite-rate chemistry effects and incomplete mixing. In particular, the role of mixing with dilution and liner air flows on the level of com-bustion inhomogeneities at the combustor’s exit is highlighted. The species that most contribute to indirect noise are identified and the transfer functions of a realistic NGV are computed. The noise level indicates that indirect noise generated by temperature fluctuations is larger that the indirect noise generated by compositional inhomogeneities, although the latter is not negligible and is expected to become louder in supersonic nozzles. It is also shown that relatively small fluctuations of the local flame structure can lead to significant variations of the nozzle transfer function, whose gain increases with the Mach number. This highlights the necessity of an on-line solution of the local flame structure, which is performed in this paper by CMC, for an accurate prediction of the level of compositional noise. This study opens new possibilities for the identification, separation and calculation of the sources of indirect combustion noise in realistic aeronautical gas turbines

La capanna 17 del villaggio protostorico di Bruncu ‘e S’Omu – Villa Verde (OR)

The hut 17 is placed in the late Bronze Age settlement of “Bruncu ‘e S’Omu” - Villa Verde (OR), in central western Sardin-ia. Archaeological investigations were carried out by the University of Cagliari since 2013: we mainly dealt with the north-ern area of the village, consisting of a unitary set of circular or sub-quadrangular huts, located around a central space, in which the hut 17 holds an overlooking position. The aim of this work is to trace, throughout the result of the excavations, in particular the analysis of the ceramic context, the intended purpose of the “hut” 17 and its chronology

Financial Activities Taxes and Banks' Systemic Risk

The recent financial crisis has highlighted the risks posed by individual banks to the entire banking system. Next to the issue of determining individual contributions to systemic risk, the question of additional taxes on the financial sector has been debated. This paper uses SYMBOL, a micro-simulation model of the banking system, to estimate these individual contributions and compares them to the potential individual tax liabilities of banks under the assumption of a Financial Activity Tax.JRC.G.1-Scientific Support to Financial Analysi

Study of animal remains dug out during the excavations of a Nuragic village in Sardinia

This paper presents the results of the zooarchaeological analysis of the faunal materials brought to light during the excavations set up in the Nuragic village surrounding the Santu Antine Nuraghe, near Torralba (Sassari), Sardinia. Precisely, the remains come from the structure of the village named by archaeologists hut 12. They are 779 specimens out of thousands animal remains from the whole archaeological site. The majority of the rests belong to sheep (Ovis aries) or goats (Capra hircus), cattle (Bos taurus), pigs (Sus scrofa) and deers (Cervus elaphus). Such material may provide suggestions about the productive use of animals in the village and point out the importance of the economical management of animals in the Nuragic society. Indeed, many remains show signs with human origin, which testify that the hut may have been a workplace where bone fragments were processed to obtain different kind of tools

The effect of age, anatomical site and bone structure on osteogenesis in New Zealand White rabbit

Among animal models, rabbits are widely used in medical research, as they fill the gap between smaller models, commonly employed in basic science, and larger ones, which are better suited for preclinical trials. Given their rapid growth, rabbits provide a valuable system for the evaluation of bone implants for tissue regeneration. By means of a histomorphometric analysis, here we quantified the mineral apposition rates (MARs) in osteonic, periosteum and endosteum osteogenic fronts, of skeletal elements within femur, tibia, radius, ulna, frontal and parietal bones in New Zealand White rabbits aged 6, 7 and 8 months. Our hypothesis is that the MAR varies according to the skeletal maturity of the animal, and also within the skeletal elements and the osteogenic fronts considered. In the present study we show that the MAR in both femur and tibia is significantly higher than in ulna and radius. We also demonstrate that the MAR in parietal bones is significantly higher compared to the MAR of both frontal and forelimb bones. Contrary to what was expected, the MARs of all the skeletal elements considered were not decreased following full skeletal maturity. Finally, the MAR of the osteonic-osteogenic front is the lowest in all of the skeletal elements considered. In conclusion, these results provide new important insights for the evaluation of bone implants, casting a light on the role of both age and osteogenic fronts on the bone MAR, and providing valuable information on the physiological bone turnover in New Zealand White rabbits