Biology and behaviour of the neotropical ant-mimicking spider Aphantochilus rogersi (Araneae: Aphantochilidae): nesting, maternal care and ontogeny of ant-hunting techniques

Aphantochilus rogersi is an ant-mimicking spider that preys exclusively on cephalotine ants. The spiders oviposit in close proximity to nests of the model ant Zacryptocerus pusillus, and emergent spiderlings tend to remain in the vicinity of natal egg sacs. Females of A. rogersi actively defend their egg sacs against approaching workers of Z. pusillus, but the latter may sometimes destroy the eggs. Feeding specialization on these ants is confirmed by more than 300 observations of young and adult A. rogersi carrying ant corpses in the held. Although A. rogersi possesses several behavioural traits which may reduce the risk of being injured by ants during subjugation, field and laboratory observations showed that social defence by Z. pusillus may cause mutilation to the spiders. Tests in captivity revealed an ontogenetic change in the prey-capture techniques employed by A. rogersi. Early-instar spiderlings can apparently only seize the ant's petiole tightly if they are able to approach the ant from the front. As the ant is paralysed, the spiderling positions itself vertically in relation to the substratum. Larger spiders, on the other hand, attack ants most frequently from behind, and seem better equipped to seize the ant's petiole firmly with their larger chelicerae. Owing to their greater strength, late-instar spiders are able to Lift the struggling ant aloft. The selection of a suitable oviposition site, the mother's ability to defend herself and the eggs from nearby ants, and the capacity to capture and subdue ants safely from emergence to maturity, are regarded as crucial traits inherent in the mimetic and feeding specialization by A. rogersi.

Synthesis and characterization of solid molybdenum(VI) complexes with glycolic, mandelic and tartaric acids. Photochemistry behaviour of the glycolate molybdenum complex

The complexes (NH4)(2)[ MoO2( C2H2O3)(2)]center dot H2O, (NH4)(2)[MoO2(C8H6O3)(2)] and (NH4)(2) [MoO3(C4H4O6)]center dot H2O were prepared by reaction of MoO3 with glycolic, mandelic and tartaric acids, respectively. The complexes were characterized by elemental and thermal analysis, IR spectroscopy and X- ray diffraction. Crystals of the glycolate and tartarate complexes are orthorhombic and the mandelate complex is monoclinic. Elemental and thermal analysis data showed that the glycolate and tartarate complexes are monohydrated. Hydration water is not present in the structure of the mandelate complex. IR spectra showed COO- is involved in coordination as well as the oxygen atom of the deprotonated hydroxyl group of the alpha-carbon. The glycolate molybdenum complexes with general formula M-2[MoO2(C2H2O3)(2)]center dot nH(2)O, where M is an alkali metal and n=1 or 1/2, were also prepared and characterized. Aqueous solutions of the glycolate complex become blue and mandelate and tartarate complexes change to yellow or brown when exposed to UV- radiation.

Thermistor behaviour and electric conduction analysis of Ni-doped niobate ferroelectric: the role of multiple beta parameters

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An assessment of the economic impact of climate change on the Agriculture, Energy and Health sectors in Trinidad and Tobago

This report analyses the agriculture, energy, and health sectors in Trinidad and Tobago to assess the potential economic impacts of climate change on the sectors. The fundamental aim of this report is to assist with the development of strategies to deal with the potential impact of climate change on Trinidad and Tobago. It also has the potential to provide essential input for identifying and preparing policies and strategies to help advance the Caribbean subregion closer to solving problems associated with climate change and attaining individual and regional sustainable development goals. Some of the key anticipated impacts of climate change for the Caribbean include elevated air and sea-surface temperatures, sea-level rise, possible changes in extreme events and a reduction in freshwater resources. The economic impact of climate change on the three sectors was estimated for the A2 and B2 IPCC scenarios until 2050. An exploration of various adaptation strategies was also undertaken for each sector using standard evaluation techniques. The study of the impact of climate change on the agriculture sector focused on root crops, green vegetables and fisheries. For these sectors combined, the cumulative loss under the A2 scenario is calculated as approximately B$2.24 and approximately B$1.72 under the B2 scenario by 2050. This is equivalent to 1.37% and 1.05% of the 2008 GDP under the A2 and B2 scenarios, respectively. Given the potential for significant damage to the agriculture sector a large number of potential adaptation measures were considered. Out of these a short-list of 10 potential options were selected by applying 10 evaluation criteria. All of the adaptation strategies showed positive benefits. The analysis indicate that the options with the highest net benefits are: (1) Building on-farm water storage, (2) Mainstreaming climate change issues into agricultural management and (3) Using drip irrigation. Other attractive options include water harvesting. The policy decisions by governments should include these assessments, the omitted intangible benefits, as well as the provision of other social goals such as employment. The analysis of the energy sector has shown that the economic impact of climate change during 2011-2050 is similar under the A2 (US$142.88 million) and B2 (US$134.83 million) scenarios with A2 scenario having a slightly higher cost (0.737% of 2009 GDP) than the B2 scenario (0.695% of 2009 GDP) for the period. On the supply side, analyses indicate that Trinidad and Tobago’s energy sector will be susceptible to the climate change policies of major energy-importing countries (the United States of America and China), and especially to their renewable energy strategies. Implementation of foreign oil substitution policy by the United States of America will result in a decline in Trinidad and Tobago’s Liquefied Natural Gas (LNG) export (equivalent to 2.2% reduction in 2009 GDP) unless an alternative market is secured for the lost United States of America market. China, with its rapid economic growth and the highest population in the world, offers a potential replacement market for Trinidad and Tobago’s LNG export. In this context the A2 scenario will offer the best option for Trinidad and Tobago’s energy sector. The cost-benefit analysis undertaken on selected adaptation strategies reveal that the benefit-cost ratio of replacing electric water heaters with solar water heaters is the most cost-effective. It was also found that the introduction of Compact Fluorescent Light (CFL) and Variable Refrigerant Volume (VRV) air conditioners surpasses the projected cost of increased electricity consumption due to climate change, and provides an economic rationale for the adoption of these adaptation options even in a situation of increased electricity consumption occasioned by climate change. Finally, the conversion of motor fleets to Compressed Natural Gas (CNG) is a cost-effective adaptation option for the transport sector, although it has a high initial cost of implementation and the highest per capita among the four adaptation options evaluated. To investigate the effect of climate change on the health sector dengue fever, leptospirosis, food borne illnesses, and gastroenteritis were examined. The total number of new dengue cases for the period 2008 to 2050 was 204,786 for BAU, 153,725 for A2 and 131,890 for the B2 scenario. With regard to the results for leptospirosis, A2 and B2 seem to be following a similar path with total number of new cases in the A2 scenario being 9,727 and 9,218 cases under the B2 scenario. Although incidence levels in the BAU scenario coincided with those of A2 and B2 prior to 2020, they are somewhat lower post 2020. A similar picture emerges for the scenarios as they relate to food-borne illnesses and to gastroenteritis. Specifically for food-borne illnesses, the BAU scenario recorded 27,537 cases, the A2 recorded 28,568 cases and the B2 recorded 28,679 cases. The focus on the selected sources of morbidity in the health sector has highlighted the fact that the vulnerability of the country’s health sector to climate change does not depend solely on exogenously derived impacts, but also on the behaviour and practices among the population. It is clear that the vulnerability which became evident in the analysis of the impacts on dengue fever, leptospirosis and food-borne illnesses is not restricted solely to climate or other external factors. The most important adaptation strategy being recommended targets lifestyle, behaviour and attitude changes. The population needs to be encouraged to alter their behaviours and practices so as to minimise their exposure to harmful outcomes as it relates to the incidence of these diseases.

An assessment of the economic impact of climate change on the water sector in the Turks and Caicos Islands

The best description of water resources for Grand Turk was offered by Pérez Monteagudo (2000) who suggested that rain water was insufficient to ensure a regular water supply although water catchment was being practised and water catchment possibilities had been analysed. Limestone islands, mostly flat and low lying, have few possibilities for large scale surface storage, and groundwater lenses exist in very delicate equilibrium with saline seawater, and are highly likely to collapse due to sea level rise, improper extraction, drought, tidal waves or other extreme event. A study on the impact of climate change on water resources in the Turks and Caicos Islands is a challenging task, due to the fact that the territory of the Islands covers different environmental resources and conditions, and accurate data are lacking. The present report is based on collected data wherever possible, including grey data from several sources such as the Intergovernmental Panel on Climate Change (IPCC) and Cuban meteorological service data sets. Other data were also used, including the author’s own estimates and modelling results. Although challenging, this was perhaps the best approach towards analysing the situation. Furthermore, IPCC A2 and B2 scenarios were used in the present study in an effort to reduce uncertainty. The main conclusion from the scenario approach is that the trend observed in precipitation during the period 1961 - 1990 is decreasing. Similar behaviour was observed in the Caribbean region. This trend is associated with meteorological causes, particularly with the influence of the North Atlantic Anticyclone. The annual decrease in precipitation is estimated to be between 30-40% with uncertain impacts on marine resources. After an assessment of fresh water resources in Turks and Caicos Islands, the next step was to estimate residential water demand based on a high fertility rate scenario for the Islands (one selected from four scenarios and compared to countries having similar characteristics). The selected scenario presents higher projections on consumption growth, enabling better preparation for growing water demand. Water demand by tourists (stopover and excursionists, mainly cruise passengers) was also obtained, based on international daily consumption estimates. Tourism demand forecasts for Turks and Caicos Islands encompass the forty years between 2011 and 2050 and were obtained by means of an Artificial Neural Networks approach. for the A2 and B2 scenarios, resulting in the relation BAU>B2>A2 in terms of tourist arrivals and water demand levels from tourism. Adaptation options and policies were analysed. Resolving the issue of the best technology to be used for Turks and Caicos Islands is not directly related to climate change. Total estimated water storage capacity is about 1, 270, 800 m3/ year with 80% capacity load for three plants. However, almost 11 desalination plants have been detected on Turks and Caicos Islands. Without more data, it is not possible to estimate long term investment to match possible water demand and more complex adaptation options. One climate change adaptation option would be the construction of elevated (30 metres or higher) storm resistant water reservoirs. The unit cost of the storage capacity is the sum of capital costs and operational and maintenance costs. Electricity costs to pump water are optional as water should, and could, be stored for several months. The costs arising for water storage are in the range of US$ 0.22 cents/m3 without electricity costs. Pérez Monteagudo (2000) estimated water prices at around US$ 2.64/m3 in stand points, US$ 7.92 /m3 for government offices, and US$ 13.2 /m3for cistern truck vehicles. These data need to be updated. As Turks and Caicos Islands continues to depend on tourism and Reverse Osmosis (RO) for obtaining fresh water, an unavoidable condition to maintaining and increasing gross domestic product(GDP) and population welfare, dependence on fossil fuels and vulnerability to increasingly volatile prices will constitute an important restriction. In this sense, mitigation supposes a synergy with adaptation. Energy demand and emissions of carbon dioxide (CO2) were also estimated using an emissions factor of 2. 6 tCO2/ tonne of oil equivalent (toe). Assuming a population of 33,000 inhabitants, primary energy demand was estimated for Turks and Caicos Islands at 110,000 toe with electricity demand of around 110 GWh. The business as usual (BAU), as well as the mitigation scenarios were estimated. The BAU scenario suggests that energy use should be supported by imported fossil fuels with important improvements in energy efficiency. The mitigation scenario explores the use of photovoltaic and concentrating solar power, and wind energy. As this is a preliminary study, the local potential and locations need to be identified to provide more relevant estimates. Macroeconomic assumptions are the same for both scenarios. By 2050, Turks and Caicos Islands could demand 60 m toe less than for the BAU scenario.

The time course of aggressive behaviour in juvenile matrinxa Brycon amazonicus fed with dietary L-tryptophan supplementation

This study evaluated the influence of dietary L-tryptophan (TRP) supplementation on the time course of aggressive behaviour and on neuroendocrine and hormonal indicators in juvenile matrinxA Brycon amazonicus. Supplementation with TRP promoted a change in the fight pattern at the beginning of an interaction with an intruder, resulting in decreased aggressive behaviours during the first 20min. The decrease in aggression did not persist throughout the interaction but increased at 3 and 6h after the beginning of the fight. Monoamine levels in the hypothalamus were not influenced by TRP before or after the fight; however, the hypothalamic serotonin (5-HT) concentration and the 5-hydroxyindole-3-acetic acid (5HIAA):5-HT ratio were significantly correlated with the reduction in aggressive behaviour at the beginning of the fight. Cortisol was not altered by TRP before the fight. After the fight cortisol increased to higher levels in B. amazonicus fed with supplementary TRP. These results indicate that TRP supplementation alters the aggressive behaviour of B. amazonicus and that this effect is limited to the beginning of the fight, suggesting a transient effect of TRP on aggressive behaviour. This is the first study reporting the effects of TRP supplementation on the time course of aggressive interaction in fishes. (C) 2013 The Fisheries Society of the British Isles

Electrochemical behaviour of copper electrode in concentrated sulfuric acid solutions

The electrochemical behaviour of copper in 6.0 mol 1-1 sulfuric acid at 30°C, was studied by means of the potentiodynamic method. At low potential sweep rates, v < 200 m V s-1, the data reveal that the anodic process is basically constituted of copper dissolution and a film formation which inhibits further metal oxidation and which may undergo further dissolution. For higher potential sweep rates, a modification in the passivation region of the voltammogram is observed. It can be ascribed to a change in the passivation mechanism which possibly involves different surface species. The kineticrelationships derived from the potentiodynamic I/E curves obtained at low v suggest a film formation via a dissolution/precipitation mechanism. © 1993.

Animal performance, feeding behaviour and carcass traits of feedlot cattle diet fed with agro-industrial by-product as fat source

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural changes and dynamic behaviour of vanadium oxide-based catalysts for gas-phase selective oxidations

Selective oxidation is one of the simplest functionalization methods and essentially all monomers used in manufacturing artificial fibers and plastics are obtained by catalytic oxidation processes. Formally, oxidation is considered as an increase in the oxidation number of the carbon atoms, then reactions such as dehydrogenation, ammoxidation, cyclization or chlorination are all oxidation reactions. In this field, most of processes for the synthesis of important chemicals used vanadium oxide-based catalysts. These catalytic systems are used either in the form of multicomponent mixed oxides and oxysalts, e.g., in the oxidation of n-butane (V/P/O) and of benzene (supported V/Mo/O) to maleic anhydride, or in the form of supported metal oxide, e.g., in the manufacture of phthalic anhydride by o-xylene oxidation, of sulphuric acid by oxidation of SO2, in the reduction of NOx with ammonia and in the ammoxidation of alkyl aromatics. In addition, supported vanadia catalysts have also been investigated for the oxidative dehydrogenation of alkanes to olefins , oxidation of pentane to maleic anhydride and the selective oxidation of methanol to formaldehyde or methyl formate [1]. During my PhD I focused my work on two gas phase selective oxidation reactions. The work was done at the Department of Industrial Chemistry and Materials (University of Bologna) in collaboration with Polynt SpA. Polynt is a leader company in the development, production and marketing of catalysts for gas-phase oxidation. In particular, I studied the catalytic system for n-butane oxidation to maleic anhydride (fluid bed technology) and for o-xylene oxidation to phthalic anhydride. Both reactions are catalyzed by systems based on vanadium, but catalysts are completely different. Part A is dedicated to the study of V/P/O catalyst for n-butane selective oxidation, while in the Part B the results of an investigation on TiO2-supported V2O5, catalyst for o-xylene oxidation are showed. In Part A, a general introduction about the importance of maleic anhydride, its uses, the industrial processes and the catalytic system are reported. The reaction is the only industrial direct oxidation of paraffins to a chemical intermediate. It is produced by n-butane oxidation either using fixed bed and fluid bed technology; in both cases the catalyst is the vanadyl pyrophosphate (VPP). Notwithstanding the good performances, the yield value didn’t exceed 60% and the system is continuously studied to improve activity and selectivity. The main open problem is the understanding of the real active phase working under reaction conditions. Several articles deal with the role of different crystalline and/or amorphous vanadium/phosphorous (VPO) compounds. In all cases, bulk VPP is assumed to constitute the core of the active phase, while two different hypotheses have been formulated concerning the catalytic surface. In one case the development of surface amorphous layers that play a direct role in the reaction is described, in the second case specific planes of crystalline VPP are assumed to contribute to the reaction pattern, and the redox process occurs reversibly between VPP and VOPO4. Both hypotheses are supported also by in-situ characterization techniques, but the experiments were performed with different catalysts and probably under slightly different working conditions. Due to complexity of the system, these differences could be the cause of the contradictions present in literature. Supposing that a key role could be played by P/V ratio, I prepared, characterized and tested two samples with different P/V ratio. Transformation occurring on catalytic surfaces under different conditions of temperature and gas-phase composition were studied by means of in-situ Raman spectroscopy, trying to investigate the changes that VPP undergoes during reaction. The goal is to understand which kind of compound constituting the catalyst surface is the most active and selective for butane oxidation reaction, and also which features the catalyst should possess to ensure the development of this surface (e.g. catalyst composition). On the basis of results from this study, it could be possible to project a new catalyst more active and selective with respect to the present ones. In fact, the second topic investigated is the possibility to reproduce the surface active layer of VPP onto a support. In general, supportation is a way to improve mechanical features of the catalysts and to overcome problems such as possible development of local hot spot temperatures, which could cause a decrease of selectivity at high conversion, and high costs of catalyst. In literature it is possible to find different works dealing with the development of supported catalysts, but in general intrinsic characteristics of VPP are worsened due to the chemical interaction between active phase and support. Moreover all these works deal with the supportation of VPP; on the contrary, my work is an attempt to build-up a V/P/O active layer on the surface of a zirconia support by thermal treatment of a precursor obtained by impregnation of a V5+ salt and of H3PO4. In-situ Raman analysis during the thermal treatment, as well as reactivity tests are used to investigate the parameters that may influence the generation of the active phase. Part B is devoted to the study of o-xylene oxidation of phthalic anhydride; industrially, the reaction is carried out in gas-phase using as catalysts a supported system formed by V2O5 on TiO2. The V/Ti/O system is quite complex; different vanadium species could be present on the titania surface, as a function of the vanadium content and of the titania surface area: (i) V species which is chemically bound to the support via oxo bridges (isolated V in octahedral or tetrahedral coordination, depending on the hydration degree), (ii) a polymeric species spread over titania, and (iii) bulk vanadium oxide, either amorphous or crystalline. The different species could have different catalytic properties therefore changing the relative amount of V species can be a way to optimize the catalytic performances of the system. For this reason, samples containing increasing amount of vanadium were prepared and tested in the oxidation of o-xylene, with the aim of find a correlations between V/Ti/O catalytic activity and the amount of the different vanadium species. The second part deals with the role of a gas-phase promoter. Catalytic surface can change under working conditions; the high temperatures and a different gas-phase composition could have an effect also on the formation of different V species. Furthermore, in the industrial practice, the vanadium oxide-based catalysts need the addition of gas-phase promoters in the feed stream, that although do not have a direct role in the reaction stoichiometry, when present leads to considerable improvement of catalytic performance. Starting point of my investigation is the possibility that steam, a component always present in oxidation reactions environment, could cause changes in the nature of catalytic surface under reaction conditions. For this reason, the dynamic phenomena occurring at the surface of a 7wt% V2O5 on TiO2 catalyst in the presence of steam is investigated by means of Raman spectroscopy. Moreover a correlation between the amount of the different vanadium species and catalytic performances have been searched. Finally, the role of dopants has been studied. The industrial V/Ti/O system contains several dopants; the nature and the relative amount of promoters may vary depending on catalyst supplier and on the technology employed for the process, either a single-bed or a multi-layer catalytic fixed-bed. Promoters have a quite remarkable effect on both activity and selectivity to phthalic anhydride. Their role is crucial, and the proper control of the relative amount of each component is fundamental for the process performance. Furthermore, it can not be excluded that the same promoter may play different role depending on reaction conditions (T, composition of gas phase..). The reaction network of phthalic anhydride formation is very complex and includes several parallel and consecutive reactions; for this reason a proper understanding of the role of each dopant cannot be separated from the analysis of the reaction scheme. One of the most important promoters at industrial level, which is always present in the catalytic formulations is Cs. It is known that Cs plays an important role on selectivity to phthalic anhydride, but the reasons of this phenomenon are not really clear. Therefore the effect of Cs on the reaction scheme has been investigated at two different temperature with the aim of evidencing in which step of the reaction network this promoter plays its role.

Influence of habitat and climate change on European bird communities

Die Fragmentierung von Waldgebieten, der Verlust geeigneter Habitate, die Invasion exotischer Arten und globale Klimaveränderung haben auf Artengemeinschaften erhebliche Auswirkungen. Vögel dienen in vielen Fällen als Indikatorarten für Umweltveränderungen und, besonders, für Veränderungen im Zusammenhang mit globaler Erwärmung. In meiner Arbeit habe ich zuerst einen Literaturüberblick über die Auswirkungen globaler Klimaveränderung auf die Verbreitungsgebiete, den Artenreichtum und die Zusammensetzung von Vogelgemeinschaften dargestellt. Zahlreiche Untersuchungen zeigen, daß die Grenzen der Verbreitungsgebiete der meisten Vogelarten mit klimatischen Faktoren korrelieren. Verschiebungen der Verbreitungsgebiete in nördliche Richtung oder in höhere Regionen im Gebirge konnten bereits für viele temperate Vogelarten beobachtet werden. Weiterhin wurde ein zunehmender Artenreichtum besonders in nördlichen Breiten und in höheren Lagen für viele temperate Vogelgemeinschaften vorhergesagt. In trockenen Gebieten ist dagegen mit einer Abnahme des Artenreichtums zu rechnen. Im zweiten Teil meiner Arbeit habe ich untersucht, ob beobachtete Veränderungen in der Zusammensetzung europäischer Vogelgemeinschaften tatsächlich durch aktuelle Klimaveränderungen beeinflußt werden. Das Zugverhalten der Arten war dabei ein Schwerpunkt der Untersuchung, weil zu erwarten war, daß Vogelarten mit verschiedenem Zugverhalten unterschiedlich auf Klimaveränderungen reagieren. Ich habe ein Regressionsmodell genutzt, welches die räumliche Beziehung zwischen dem Anteil von Langstreckenziehern, Kurzstreckenziehern und Standvögeln in europäischen Vogelgemeinschaften und verschiedenen Klimavariablen beschreibt. Für 21 Gebiete in Europa habe ich Daten über beobachtete Veränderungen in der Struktur der Vogelgemeinschaften und isochrone Klimaveränderungen zusammengetragen. Mit Hilfe dieser Klimaveränderungen und dem räumlichen Regressionsmodell konnte ich berechnen, welche Veränderungen in den Vogelgemeinschaften aufgrund der veränderten Klimabedingungen zu erwarten wären und sie mit beobachteten Veränderungen vergleichen. Beobachtete und berechnete Veränderungen korrelierten signifikant miteinander. Die beobachteten Veränderungen konnten nicht durch räumliche Autokorrelationseffekte oder durch alternative Faktoren, wie z.B. Veränderungen in der Landnutzung, erklärt werden. Im dritten Teil der Arbeit untersuchte ich für eine mitteleuropäische Vogelgemeinschaft welchen Einfluß Habitatveränderungen, die Invasion exotischer Arten und die Klimaveränderung auf Veränderungen der Häufigkeit und Verbreitungsgröße der 159 Vogelarten am Bodensee zwischen 1980-1981 und 2000-2002 hatten. Dabei konnte gezeigt werden, daß Veränderungen in der regionalen Abundanz sowohl durch Habitatveränderungen als auch durch Klimavänderungen hervorgerufen wurden. Exotische Arten schienen in dieser Zeit keinen bedeutenden Einfluß zu haben. Besonders bei Agrarlandarten, Arten mit nördlicheren Verbreitungsgebieten und bei Langstreckenziehern konnten signifikante Abnahmen in der Abundanz beobachtet werden. Vor allem die anhaltenden negativen Bestandsveränderungen bei Langstreckenziehern und die in den letzten zehn Jahren aufgetretenen Abnahmen nördlicher verbreiteter Vogelarten deuten darauf hin, daß die Klimaveränderung aktuell als der größte Einfluß für Vögel in Europa angesehen werden muß. Insgesamt zeigen die Ergebnisse dieser Arbeit, daß sich der anhaltende Druck auf die Umwelt in erster Linie durch Habitat- und Klimaveränderungen manifestiert.

Human bone: the tissue characteristics determining its mechanical behaviour

The present thesis illustrates the research carried out during the PhD studies in Bioengineering. The research was aimed to characterise the human bone tissue, with particular regard to the differences between cortical and trabecular bone. The bone tissue characteristics that affect its mechanical properties were verified or identified, using an experimental approach, to corroborate or refute hypotheses based on the state of the art in bone tissue biomechanics. The studies presented in the present PhD thesis were designed to investigate aspects of bone tissue biomechanics, which were in need of a more in-depth examination since the data found in the literature was contradictory or scarce. In particular, the work was focalised on the characterisation of the basic structure of the bone tissue (groups of lamellae), its composition, its spatial organisation (trabecular bone microarchitecture) and their influence on the mechanical properties. In conclusion, the present thesis integrates eight different studies on the characterisation of bone tissue. A more in-depth examination of some of the aspects of bone tissue biomechanics where the data found in the literature was contradictory or scarce was performed. Bone tissue was investigated at several scales, from its composition up to its spatial organization, to determine which parameters influence the mechanical behaviour of the tissue. It was found that although the composition and real density of bone tissue are similar, the differences in structure at different levels cause differences between the two types of bone tissue (cortical and trabecular) in mechanical properties. However, the apparent density can still be considered a good predictor of the mechanical properties of both cortical and trabecular bone. Finally, it was found that the bone tissue characteristics might change when a pathology is present, as demonstrated for OA.

Effects of 2013 Cap reform on land market: regionalized farm payments and changes in farmers’ intended behaviour

The CAP reform process has been a central issue for agricultural economics research in recent years, and is gaining further attention in view of the post-2013 perspectives (Viaggi et al., 2010; Bartolini et al., 2011). Today the CAP is in the middle of a new reform process. Through the debate generated by the official proposals, published in October 2011 (COM(2011)625/3), the European Union (EU) engaged in a revision of the CAP ended on 26 June 2013 when a political agreement has been reached (IP/13/613, MEMO-13-621 and IP/13/864). In particular, in Italy the switch of the payment regime from historical to regional bases will take place. The underlying assumption is that the shift to regionalized payments changes the remuneration of inputs and has an impact on farmers’ allocation of fixed resources. In this context, farmers are expected to adjust their plans to the new policy environment as the regionalization of support is meant to create a change in incentives faced by farmers. The objective of this thesis is to provide an ex-ante analysis of the potential impact of the introduction of regionalized payments, within the post-2013 CAP reform, on the land market. Regionalized payments seem to produce differentiated effects and contribute to a general (slight) increase of land exchanges. The individual reaction to the new payments introduction would be different depending on location and specialization. These effects seem to be also strongly influenced by the difference in historical payments endowment and value, i.e. by the previous historical system of distribution of payments.

Influence of nest site on the behaviour of laying hens

Low rates of nest acceptance by laying hens are a major problem in commercial poultry farming operations with aviary systems, leading to costly manual collection and cleaning of mislaid eggs. To gain knowledge about factors affecting nest use, laying hens' preferences for different nest locations were tested. Nests are normally installed at one of two sites: against a wall of the hen house or integrated into one tier of the aviary rack The preferences of laying hens for different nest sites have never been examined under commercial conditions. The aim of this study is to investigate whether behavioural differences can be detected between the different nest sites. The study consists of two consecutive trials involving 5027 Lohmann Selected Leghorn hens (LSL) and 601 layer hybrids selected for extensive housing conditions (EXT). The hens were randomly assigned to eight compartments per trial in groups of 355-360 LSL or 300 EXT in a laying hen house. Four compartments were equipped with a Volito Voletage (R) aviary system (VV), and four were equipped with a Rihs Bolegell (R) aviary system (RB), both of which contained either integrated or wall-placed nests when the experiments started. A strongly balanced crossover design with four periods was used. At 36, 44 and 52 weeks of age, the nest site in four out of the eight compartments was switched. Before each change, the fronts of half of the nests were videotaped during the light period, and the behaviour throughout the main laying period was analysed. Furthermore, the numbers of nest eggs and mislaid eggs in each compartment were recorded every day. No differences in the number of mislaid eggs between the two nest sites could be detected, except at the age of 20/21 weeks when hens in VV aviaries mislaid more eggs when nests were integrated (P = 0.0012). More hens stood simultaneously in front of the integrated nests than in front of wall-placed nests (P = 0.015). Activity of the laying hens increased (P = 0.0073), and stationary behavioural patterns declined (P = 0.0093), when the nests were placed by the wall. Hens inspected integrated nests for a longer duration than wall-placed nests, but wall-placed nests were visited more frequently. In addition to the nest site, the width of the platform in front of the nest influenced laying hen behaviour. Compared with narrower platforms, balance movements decreased on wider ones. Additionally, the platform design had to be taken into account as well, given that hens could not stand or walk as securely on wooden slats as on a grid floor. (C) 2011 Elsevier B.V. All rights reserved.

The effect of seasonal temperature variation on behaviour and metabolism in the freshwater mussel (Unio tumidus)

Temperature plays a critical role in determining the biology of ectotherms. Many animals have evolved mechanisms that allow them to compensate biological rates, i.e. adjust biological rates to overcome thermodynamic effects. For low energy-organisms, such as bivalves, the costs of thermal compensation may be greater than the benefits, and thus prohibitive. To examine this, two experiments were designed to explore thermal compensation in Unio tumidus. Experiment 1 examined seasonal changes in behaviour in U. tumidus throughout a year. Temperature had a clear effect on burrowing rate with no evidence of compensation. Valve closure duration and frequency were also strongly affected by seasonal temperature change, but there was slight evidence of partial compensation. Experiment 2 examined oxygen consumption during burrowing, immediately following valve opening and at rest in summer (24 °C), autumn (14 °C), winter (4 °C), and spring (14 °C) acclimatized U. tumidus. Again, there was little evidence of burrowing rate compensation, but some evidence of partial compensation of valve closure duration and frequency. None of the oxygen compensation rates showed any evidence of thermal compensation. Thus, in general, there was only very limited evidence of thermal compensation of behaviour and no evidence of thermal compensation of oxygen compensation rates. Based upon this evidence, we argue that there is no evolutionary pressure for these bivalves to compensate these biological rates. Any pressure may be to maintain or even lower oxygen consumption as their only defence against predation is to close their valves and wait. An increase in oxygen consumption will be detrimental in this regard so the cost of thermal compensation may outweigh the benefits.

The behaviour of incompatible elements during hydrous melting of metasomatized peridotite at 4–6 GPa and 1000 °C–1200 °C

Trace element behavior during hydrous melting of a metasomatized garnet–peridotite was examined at pressures of 4–6 GPa and temperatures of 1000 °C–1200 °C, conditions appropriate for fluid penetrating the mantle wedge atop the subducting slab. Experiments were performed in a rocking multi-anvil apparatus using a diamond-trap setup. The compositions of the fluid and melt phases were measured using the cryogenic LA-ICP-MS technique. The water-saturated solidus of the K-lherzolite composition is located between 900 °C and 1000 °C at 4 GPa and between 1000 °C and 1100 °C at 5 and 6 GPa. The partition coefficients between fluid or melt and clinopyroxene reveal an asymmetric MREE trough with a minimum at Dy. The clinopyroxene in equilibrium with aqueous fluids is characterized by DUfluid–cpx > DThfluid–cpx while DUmelt–cpx tends to be similar to DThmelt–cpx. The partition coefficients between fluid or melt and garnet reveal very strong light to heavy REE fractionation, DLa/DLu from 95 (hydrous melt) to 1600 (aqueous fluid). The LILE are highly incompatible with partition coefficients > 50. The behavior of HFSE are decoupled, with DZr,Hf close to 1 while DNb,Ta > 10. Garnet is characterized by DUmelt/fluid–garnet < DThmelt/fluid–garnet. A comparison of our experimental partitioning results for trivalent cations as well as the results from the literature and the calculations carried out using the lattice strain model adapted to the presence of water in the bulk system indicates that H2O in the fluid or melt phase has a prominent effect on trace element partitioning. Garnet in mantle rocks in equilibrium with an aqueous fluid is characterized by significantly higher Do(3 +) for REE in the X site of the garnet compared with the partitioning values of the optimal cation in garnet in equilibrium with hydrous melts. Our data show for the first time that the change in the nature of the mobile phase (fluid vs. melt) does affect the affinities of trace elements into the garnet crystal at conditions below the second critical endpoint of the system. The same also applies for clinopyroxene, although this is less clear. Consequently, our new data allow for refinements in predictive modeling of element transfer from the slab to the mantle wedge and of possible compositions of metasomatized mantle that sources OIB magmatism.