Reduced knee flexion is a possible cause of increased loading rates in individuals with patellofemoral pain

Stair ascent is an activity that exacerbates symptoms of individuals with patellofemoral pain. The discomfort associated with this activity usually results in gait modification such as reduced knee flexion in an attempt to reduce pain. Although such compensatory strategy is a logical approach to decrease pain, it also reduces the normal active shock absorption increasing loading rates and may lead to deleterious and degenerative changes of the knee joint. Thus, the aims of this study were (i) to investigate whether there is reduced knee flexion in adults with PFP compared to healthy controls; and (ii) to analyze loading rates in these subjects, during stair climbing. Twenty-nine individuals with patellofemoral pain and twenty-five control individuals (18-30years) participated in this study. Each subject underwent three-dimensional kinematic and kinetic analyses during stair climbing on two separate days. Between-groups analyses of variance were performed to identify differences in peak knee flexion and loading rates. Intraclass correlation coefficient was performed to verify the reliability of the variables. On both days, the patellofemoral pain group demonstrated significantly reduced peak knee flexion and increased loading rates. In addition, the two variables obtained high to very high reliability. Reduced knee flexion during stair climbing as a strategy to avoid anterior knee pain does not seem to be healthy for lower limb mechanical distributions. Repeated loading at higher loading rates may be damaging to lower limb joints.

Q-angle static or dynamic measurements, which is the best choice for patellofemoral pain?

The elevated Q-angle seems to be one of the most suggested factors contributing to patellofemoral pain. Females with patellofemoral pain are often evaluated through static clinical tests in clinical practice. However, the adaptations seem to appear more frequently in dynamic conditions. Performing static vs. dynamic evaluations of widely used measures would add to the knowledge in this area. Therefore, the aim of this study was to determine the reliability and discriminatory capability of three Q-angle measurements: a static clinical test, peak dynamic knee valgus during stair ascent and a static measurement using a three-dimensional system. Twenty-nine females with patellofemoral pain and twenty-five pain-free females underwent clinical Q-angle measurement and static and dynamic knee valgus measurements during stair ascent, using a three-dimensional system. All measurements were obtained and comparisons between groups, reliability and discriminatory capability were calculated. Peak dynamic knee valgus was found to be greater in the patellofemoral pain group. On the other hand, no significant effects were found for static knee valgus or clinical Q-angle measurements between groups. The dynamic variable demonstrated the best discriminatory capability. Low values of reliability were found for clinical Q-angle, in contrast to the high values found for the three-dimensional system measurements. Based on our findings, avoiding or correcting dynamic knee valgus during stair ascent may be an important component of rehabilitation programs in females with patellofemoral pain who demonstrate excessive dynamic knee valgus. Q-angle static measurements were not different between groups and presented poor values of discriminatory capability.

Class Notes for Math 918: Cohen Macaulay Modules, Instructor Roger Wiegand

Topics covered are: Cohen Macaulay modules, zero-dimensional rings, one-dimensional rings, hypersurfaces of finite Cohen-Macaulay type, complete and henselian rings, Krull-Remak-Schmidt, Canonical modules and duality, AR sequences and quivers, two-dimensional rings, ascent and descent of finite Cohen Macaulay type, bounded Cohen Macaulay type.

Diabetic patients with and without peripheral neuropathy reveal different hip and ankle biomechanical strategies during stair descent

Background: The progression of diabetes and the challenge of daily tasks may result in changes in biomechanical strategies. Descending stairs is a common task that patients have to deal with, however it still has not been properly studied in this population. Objectives: We describe and compare the net joint moments and kinematics of the lower limbs in diabetic individuals with and without peripheral neuropathy and healthy controls during stair descent. Method: Forty-two adults were assessed: control group (13), diabetic group (14), and neuropathic diabetic group (15). The flexor and extensor net moment peaks and joint angles of the hip, knee, and ankle were described and compared in terms of effect size and ANOVAs (p<0.05). Results: Both diabetic groups presented greater dorsiflexion [large effect size] and a smaller hip extensor moment [large effect size] in the weight acceptance phase. In the propulsion phase, diabetics with and without neuropathy showed a greater hip flexor moment [large effect size] and smaller ankle extension [large effect size]. Conclusion: Diabetic patients, even without neuropathy, revealed poor eccentric control in the weight acceptance phase, and in the propulsion phase, they showed a different hip strategy, where they chose to take the leg off the ground using more flexion torque at the hip instead of using a proper ankle extension function.

Investigação sobre as configurações sociais do subcampo do esporte paralímpico no Brasil: os processos de classificação de atletas

Este trabalho tem por objetivo investigar e delimitar formas de interação e disputas sociais presentes no movimento paralímpico brasileiro, relativos aos processos de classificação de atletas, com base em conceitos de Pierre Bourdieu. A metodologia utilizada fundamentou-se em entrevistas semiestruturadas com quatro atletas (com deficiência física ou visual, praticantes de diversas modalidades: natação, goalball, rugby e basquete em cadeira de rodas) e quatro dirigentes (2 atuantes em funções técnicas e 2 em funções administrativas do Comitê Paralímpico Brasileiro). A análise de dados apoiou-se no método Discurso do Sujeito Coletivo e suas ferramentas metodológicas (expressões-chave; ideias centrais; ancoragens; instrumentos de análise de discurso). Destacam-se como resultados: os protocolos de classificação, assim como a atuação e formação de novos classificadores, são motivo de tensões sociais neste espaço; Os classificadores exercem importante poder simbólico no subcampo; Demais agentes, como treinadores e atletas, têm suas possibilidades de ascensão diminuídas por condições sociais desfavoráveis..

Pulmonary gas exchange and acid-base state at 5,260 m in high-altitude Bolivians and acclimatized lowlanders

[EN] Pulmonary gas exchange and acid-base state were compared in nine Danish lowlanders (L) acclimatized to 5,260 m for 9 wk and seven native Bolivian residents (N) of La Paz (altitude 3,600-4,100 m) brought acutely to this altitude. We evaluated normalcy of arterial pH and assessed pulmonary gas exchange and acid-base balance at rest and during peak exercise when breathing room air and 55% O2. Despite 9 wk at 5,260 m and considerable renal bicarbonate excretion (arterial plasma HCO3- concentration = 15.1 meq/l), resting arterial pH in L was 7.48 +/- 0.007 (significantly greater than 7.40). On the other hand, arterial pH in N was only 7.43 +/- 0.004 (despite arterial O2 saturation of 77%) after ascent from 3,600-4,100 to 5,260 m in 2 h. Maximal power output was similar in the two groups breathing air, whereas on 55% O2 only L showed a significant increase. During exercise in air, arterial PCO2 was 8 Torr lower in L than in N (P < 0.001), yet PO2 was the same such that, at maximal O2 uptake, alveolar-arterial PO2 difference was lower in N (5.3 +/- 1.3 Torr) than in L (10.5 +/- 0.8 Torr), P = 0.004. Calculated O2 diffusing capacity was 40% higher in N than in L and, if referenced to maximal hyperoxic work, capacity was 73% greater in N. Buffering of lactic acid was greater in N, with 20% less increase in base deficit per millimole per liter rise in lactate. These data show in L persistent alkalosis even after 9 wk at 5,260 m. In N, the data show 1) insignificant reduction in exercise capacity when breathing air at 5,260 m compared with breathing 55% O2; 2) very little ventilatory response to acute hypoxemia (judged by arterial pH and arterial PCO2 responses to hyperoxia); 3) during exercise, greater pulmonary diffusing capacity than in L, allowing maintenance of arterial PO2 despite lower ventilation; and 4) better buffering of lactic acid. These results support and extend similar observations concerning adaptation in lung function in these and other high-altitude native groups previously performed at much lower altitudes.

The submarine volcano eruption off El Hierro Island: Effects on the scattering migrant biota and the evolution of the pelagic communities

[EN] The submarine volcano eruption off El Hierro Island (Canary Islands) on 10 October 2011 promoted dramatic perturbation of the water column leading to changes in the distribution of pelagic fauna. To study the response of the scattering biota, we combined acoustic data with hydrographic profiles and concurrent sea surface turbidity indexes from satellite imagery. We also monitored changes in the plankton and nekton communities through the eruptive and post-eruptive phases. Decrease of oxygen, acidification, rising temperature and deposition of chemicals in shallow waters resulted in a reduction of epipelagic stocks and a disruption of diel vertical migration (nocturnal ascent) of mesopelagic organisms. Furthermore, decreased light levels at depth caused by extinction in the volcanic plume resulted in a significant shallowing of the deep acoustic scattering layer. Once the eruption ceased, the distribution and abundances of the pelagic biota returned to baseline levels. There was no evidence of a volcano-induced bloom in the plankton community.

Numerical simulations of magma chamber dynamics at Campi Flegrei, and associated seismicity, deformation and gravity changes

Understanding the complex relationships between quantities measured by volcanic monitoring network and shallow magma processes is a crucial headway for the comprehension of volcanic processes and a more realistic evaluation of the associated hazard. This question is very relevant at Campi Flegrei, a volcanic quiescent caldera immediately north-west of Napoli (Italy). The system activity shows a high fumarole release and periodic ground slow movement (bradyseism) with high seismicity. This activity, with the high people density and the presence of military and industrial buildings, makes Campi Flegrei one of the areas with higher volcanic hazard in the world. In such a context my thesis has been focused on magma dynamics due to the refilling of shallow magma chambers, and on the geophysical signals detectable by seismic, deformative and gravimetric monitoring networks that are associated with this phenomenologies. Indeed, the refilling of magma chambers is a process frequently occurring just before a volcanic eruption; therefore, the faculty of identifying this dynamics by means of recorded signal analysis is important to evaluate the short term volcanic hazard. The space-time evolution of dynamics due to injection of new magma in the magma chamber has been studied performing numerical simulations with, and implementing additional features in, the code GALES (Longo et al., 2006), recently developed and still on the upgrade at the Istituto Nazionale di Geofisica e Vulcanologia in Pisa (Italy). GALES is a finite element code based on a physico-mathematical two dimensional, transient model able to treat fluids as multiphase homogeneous mixtures, compressible to incompressible. The fundamental equations of mass, momentum and energy balance are discretised both in time and space using the Galerkin Least-Squares and discontinuity-capturing stabilisation technique. The physical properties of the mixture are computed as a function of local conditions of magma composition, pressure and temperature.The model features enable to study a broad range of phenomenologies characterizing pre and sin-eruptive magma dynamics in a wide domain from the volcanic crater to deep magma feeding zones. The study of displacement field associated with the simulated fluid dynamics has been carried out with a numerical code developed by the Geophysical group at the University College Dublin (O’Brien and Bean, 2004b), with whom we started a very profitable collaboration. In this code, the seismic wave propagation in heterogeneous media with free surface (e.g. the Earth’s surface) is simulated using a discrete elastic lattice where particle interactions are controlled by the Hooke’s law. This method allows to consider medium heterogeneities and complex topography. The initial and boundary conditions for the simulations have been defined within a coordinate project (INGV-DPC 2004-06 V3_2 “Research on active volcanoes, precursors, scenarios, hazard and risk - Campi Flegrei”), to which this thesis contributes, and many researchers experienced on Campi Flegrei in volcanological, seismic, petrological, geochemical fields, etc. collaborate. Numerical simulations of magma and rock dynamis have been coupled as described in the thesis. The first part of the thesis consists of a parametric study aimed at understanding the eect of the presence in magma of carbon dioxide in magma in the convection dynamics. Indeed, the presence of this volatile was relevant in many Campi Flegrei eruptions, including some eruptions commonly considered as reference for a future activity of this volcano. A set of simulations considering an elliptical magma chamber, compositionally uniform, refilled from below by a magma with volatile content equal or dierent from that of the resident magma has been performed. To do this, a multicomponent non-ideal magma saturation model (Papale et al., 2006) that considers the simultaneous presence of CO2 and H2O, has been implemented in GALES. Results show that the presence of CO2 in the incoming magma increases its buoyancy force promoting convection ad mixing. The simulated dynamics produce pressure transients with frequency and amplitude in the sensitivity range of modern geophysical monitoring networks such as the one installed at Campi Flegrei . In the second part, simulations more related with the Campi Flegrei volcanic system have been performed. The simulated system has been defined on the basis of conditions consistent with the bulk of knowledge of Campi Flegrei and in particular of the Agnano-Monte Spina eruption (4100 B.P.), commonly considered as reference for a future high intensity eruption in this area. The magmatic system has been modelled as a long dyke refilling a small shallow magma chamber; magmas with trachytic and phonolitic composition and variable volatile content of H2O and CO2 have been considered. The simulations have been carried out changing the condition of magma injection, the system configuration (magma chamber geometry, dyke size) and the resident and refilling magma composition and volatile content, in order to study the influence of these factors on the simulated dynamics. Simulation results allow to follow each step of the gas-rich magma ascent in the denser magma, highlighting the details of magma convection and mixing. In particular, the presence of more CO2 in the deep magma results in more ecient and faster dynamics. Through this simulations the variation of the gravimetric field has been determined. Afterward, the space-time distribution of stress resulting from numerical simulations have been used as boundary conditions for the simulations of the displacement field imposed by the magmatic dynamics on rocks. The properties of the simulated domain (rock density, P and S wave velocities) have been based on data from literature on active and passive tomographic experiments, obtained through a collaboration with A. Zollo at the Dept. of Physics of the Federici II Univeristy in Napoli. The elasto-dynamics simulations allow to determine the variations of the space-time distribution of deformation and the seismic signal associated with the studied magmatic dynamics. In particular, results show that these dynamics induce deformations similar to those measured at Campi Flegrei and seismic signals with energies concentrated on the typical frequency bands observed in volcanic areas. The present work shows that an approach based on the solution of equations describing the physics of processes within a magmatic fluid and the surrounding rock system is able to recognise and describe the relationships between geophysical signals detectable on the surface and deep magma dynamics. Therefore, the results suggest that the combined study of geophysical data and informations from numerical simulations can allow in a near future a more ecient evaluation of the short term volcanic hazard.

Metamorfismo ercinico di bassa-pressione: evoluzione tettonico-metamorfica del complesso di mandatoriccio (massiccio della Sila - Calabria)

Low-pressure/high-temperature (LP/HT) metamorphic belts are characterised by rocks that experienced abnormal heat flow in shallow crustal levels (T > 600 °C; P < 4 kbar) resulting in anomalous geothermal gradients (60-150 °C/km). The abnormal amount of heat has been related to crustal underplating of mantle-derived basic magmas or to thermal perturbation linked to intrusion of large volumes of granitoids in the intermediate crust. In particular, in this latter context, magmatic or aqueous fluids are able to transport relevant amounts of heat by advection, thus favouring regional LP/HT metamorphism. However, the thermal perturbation consequent to heat released by cooling magmas is responsible also for contact metamorphic effects. A first problem is that time and space relationships between regional LP/HT metamorphism and contact metamorphism are usually unclear. A second problem is related to the high temperature conditions reached at different crustal levels. These, in some cases, can completely erase the previous metamorphic history. Notwithstanding this problem is very marked in lower crustal levels, petrologic and geochronologic studies usually concentrate in these attractive portions of the crust. However, only in the intermediate/upper-crustal levels of a LP/HT metamorphic belt the tectono-metamorphic events preceding the temperature peak, usually not preserved in the lower crustal portions, can be readily unravelled. The Hercynian Orogen of Western Europe is a well-documented example of a continental collision zone with widespread LP/HT metamorphism, intense crustal anatexis and granite magmatism. Owing to the exposure of a nearly continuous cross-section of the Hercynian continental crust, the Sila massif (northern Calabria) represents a favourable area to understand large-scale relationships between granitoids and LP/HT metamorphic rocks, and to discriminate regional LP/HT metamorphic events from contact metamorphic effects. Granulite-facies rocks of the lower crust and greenschist- to amphibolite-facies rocks of the intermediate-upper crust are separated by granitoids emplaced into the intermediate level during the late stages of the Hercynian orogeny. Up to now, advanced petrologic studies have been focused mostly in understanding P-T evolution of deeper crustal levels and magmatic bodies, whereas the metamorphic history of the shallower crustal levels is poorly constrained. The Hercynian upper crust exposed in Sila has been subdivided in two different metamorphic complexes by previous authors: the low- to very low-grade Bocchigliero complex and the greenschist- to amphibolite-facies Mandatoriccio complex. The latter contains favourable mineral assemblages in order to unravel the tectono-metamorphic evolution of the Hercynian upper crust. The Mandatoriccio complex consists mainly of metapelites, meta-arenites, acid metavolcanites and metabasites with rare intercalations of marbles and orthogneisses. Siliciclastic metasediments show a static porphyroblastic growth mainly of biotite, garnet, andalusite, staurolite and muscovite, whereas cordierite and fibrolite are less common. U-Pb ages and internal features of zircons suggest that the protoliths of the Mandatoriccio complex formed in a sedimentary basin filled by Cambrian to Silurian magmatic products as well as by siliciclastic sediments derived from older igneous and metamorphic rocks. In some localities, metamorphic rocks are injected by numerous aplite/pegmatite veins. Small granite bodies are also present and are always associated to spotted schists with large porphyroblasts. They occur along a NW-SE trending transcurrent cataclastic fault zone, which represents the tectonic contact between the Bocchigliero and the Mandatoriccio complexes. This cataclastic fault zone shows evidence of activity at least from middle-Miocene to Recent, indicating that brittle deformation post-dated the Hercynian orogeny. P-T pseudosections show that micaschists and paragneisses of the Mandatoriccio complex followed a clockwise P-T path characterised by four main prograde phases: thickening, peak-pressure condition, decompression and peak-temperature condition. During the thickening phase, garnet blastesis started up with spessartine-rich syntectonic core developed within micaschists and paragneisses. Coevally (340 ± 9.6 Ma), mafic sills and dykes injected the upper crustal volcaniclastic sedimentary sequence of the Mandatoriccio complex. After reaching the peak-pressure condition (≈4 kbar), the upper crust experienced a period of deformation quiescence marked by the static overgrowths of S2 by Almandine-rich-garnet rims and by porphyroblasts of biotite and staurolite. Probably, this metamorphic phase is related to isotherms relaxation after the thickening episode recorder by the Rb/Sr isotopic system (326 ± 6 Ma isochron age). The post-collisional period was mainly characterised by decompression with increasing temperature. This stage is documented by the andalusite+biotite coronas overgrown on staurolite porphyroblasts and represents a critical point of the metamorphic history, since metamorphic rocks begin to record a significant thermal perturbation. Peak-temperature conditions (≈620 °C) were reached at the end of this stage. They are well constrained by some reaction textures and mineral assemblages observed almost exclusively within paragneisses. The later appearance of fibrolitic sillimanite documents a small excursion of the P-T path across the And-Sil boundary due to the heating. Stephanian U-Pb ages of monazite crystals from the paragneiss, can be related to this heating phase. Similar monazite U-Pb ages from the micaschist combined with the lack of fibrolitic sillimanite suggest that, during the same thermal perturbation, micaschists recorded temperatures slightly lower than those reached by paragneisses. The metamorphic history ended with the crystallisation of cordierite mainly at the expense of andalusite. Consequently, the Ms+Bt+St+And+Sill+Crd mineral assemblage observed in the paragneisses is the result of a polyphasic evolution and is characterised by the metastable persistence of the staurolite in the stability fields of the cordierite. Geologic, geochronologic and petrographic data suggest that the thermal peak recorded by the intermediate/upper crust could be strictly connected with the emplacement of large amounts of granitoid magmas in the middle crust. Probably, the lithospheric extension in the relatively heated crust favoured ascent and emplacement of granitoids and further exhumation of metamorphic rocks. After a comparison among the tectono-metamorphic evolutions of the different Hercynian crustal levels exposed in Sila, it is concluded that the intermediate/upper crustal level offers the possibility to reconstruct a more detailed tectono-metamorphic history. The P-T paths proposed for the lower crustal levels probably underestimate the amount of the decompression. Apart from these considerations, the comparative analysis indicates that P-T paths at various crustal levels in the Sila cross section are well compatible with a unique geologic scenario, characterized by post-collisional extensional tectonics and magmas ascent.

La carriera degli attori italiani di prosa dalla scena allo schermo (1909-1916)

Most actors of the Italian silent cinema in the early 1910s have a theatrical training. Some of them are already asserted or famous actors (like Cesare Dondini, Ermete Novelli, Ermete Zacconi, Giovanni Grasso) who are invited “to pose” for the cinema following their reputation, according to a strategy of an aesthetic and cultural legitimacy launched in 1909 by film d'art of the Pathé Consortium. I think it is the proverbial readiness and strength of the stage Italian actors that create a decisive contribution to the rapid development of the national cinema industry, despite its serious structural deficiencies, from the protoindustrialized phase (1909) to the golden age of divismo (starting in 1913), until the first signs of decadence (1919), and the so-called “fall” of the UCI production and distribution system. This is the main topic of the thesis: an investigation on the Italian stage actors engaged in the film industry (“from stage to screen” as the Italian title says, but in a “post-Vardac” approach) through many different sources: periodicals, memories, personal and business letters, and also contracts, found in several archive funds. A specific chapter is dedicated to the artistic career of Febo Mari (1881-1939), real name Alfredo Rodriguez, witch is a time-sample symptomatic of deep ties established between the growing film publishing and the Italian theatrical production system in the 1910s. The Mari debut in cinema and his ascent toward screen “divo” status coincides with the parable that leads from emergence to decadence of divismo in Italy.

Welfare provision in Sweden and the dominant position of the Sap

There have been almost fifty years since Harry Eckstein' s classic monograph, A Theory of Stable Democracy (Princeton, 1961), where he sketched out the basic tenets of the “congruence theory”, which was to become one of the most important and innovative contributions to understanding democratic rule. His next work, Division and Cohesion in Democracy, (Princeton University Press: 1966) is designed to serve as a plausibility probe for this 'theory' (ftn.) and is a case study of a Northern democratic system, Norway. What is more, this line of his work best exemplifies the contribution Eckstein brought to the methodology of comparative politics through his seminal article, “ “Case Study and Theory in Political Science” ” (in Greenstein and Polsby, eds., Handbook of Political Science, 1975), on the importance of the case study as an approach to empirical theory. This article demonstrates the special utility of “crucial case studies” in testing theory, thereby undermining the accepted wisdom in comparative research that the larger the number of cases the better. Although not along the same lines, but shifting the case study unit of research, I intend to take up here the challenge and build upon an equally unique political system, the Swedish one. Bearing in mind the peculiarities of the Swedish political system, my unit of analysis is going to be further restricted to the Swedish Social Democratic Party, the Svenska Arbetare Partiet. However, my research stays within the methodological framework of the case study theory inasmuch as it focuses on a single political system and party. The Swedish SAP endurance in government office and its electoral success throughout half a century (ftn. As of the 1991 election, there were about 56 years - more than half century - of interrupted social democratic "reign" in Sweden.) are undeniably a performance no other Social Democrat party has yet achieved in democratic conditions. Therefore, it is legitimate to inquire about the exceptionality of this unique political power combination. Which were the different components of this dominance power position, which made possible for SAP's governmental office stamina? I will argue here that it was the end-product of a combination of multifarious factors such as a key position in the party system, strong party leadership and organization, a carefully designed strategy regarding class politics and welfare policy. My research is divided into three main parts, the historical incursion, the 'welfare' part and the 'environment' part. The first part is a historical account of the main political events and issues, which are relevant for my case study. Chapter 2 is devoted to the historical events unfolding in the 1920-1960 period: the Saltsjoebaden Agreement, the series of workers' strikes in the 1920s and SAP's inception. It exposes SAP's ascent to power in the mid 1930s and the party's ensuing strategies for winning and keeping political office, that is its economic program and key economic goals. The following chapter - chapter 3 - explores the next period, i.e. the period from 1960s to 1990s and covers the party's troubled political times, its peak and the beginnings of the decline. The 1960s are relevant for SAP's planning of a long term economic strategy - the Rehn Meidner model, a new way of macroeconomic steering, based on the Keynesian model, but adapted to the new economic realities of welfare capitalist societies. The second and third parts of this study develop several hypotheses related to SAP's 'dominant position' (endurance in politics and in office) and test them afterwards. Mainly, the twin issues of economics and environment are raised and their political relevance for the party analyzed. On one hand, globalization and its spillover effects over the Swedish welfare system are important causal factors in explaining the transformative social-economic challenges the party had to put up with. On the other hand, Europeanization and environmental change influenced to a great deal SAP's foreign policy choices and its domestic electoral strategies. The implications of globalization on the Swedish welfare system will make the subject of two chapters - chapters four and five, respectively, whereupon the Europeanization consequences will be treated at length in the third part of this work - chapters six and seven, respectively. Apparently, at first sight, the link between foreign policy and electoral strategy is difficult to prove and uncanny, in the least. However, in the SAP's case there is a bulk of literature and public opinion statistical data able to show that governmental domestic policy and party politics are in a tight dependence to foreign policy decisions and sovereignty issues. Again, these country characteristics and peculiar causal relationships are outlined in the first chapters and explained in the second and third parts. The sixth chapter explores the presupposed relationship between Europeanization and environmental policy, on one hand, and SAP's environmental policy formulation and simultaneous agenda-setting at the international level, on the other hand. This chapter describes Swedish leadership in environmental policy formulation on two simultaneous fronts and across two different time spans. The last chapter, chapter eight - while trying to develop a conclusion, explores the alternative theories plausible in explaining the outlined hypotheses and points out the reasons why these theories do not fit as valid alternative explanation to my systemic corporatism thesis as the main causal factor determining SAP's 'dominant position'. Among the alternative theories, I would consider Traedgaardh L. and Bo Rothstein's historical exceptionalism thesis and the public opinion thesis, which alone are not able to explain the half century social democratic endurance in government in the Swedish case.

Nature and origin of ultramafic lamprophyres and carbonatites from the borders of the Labrador Sea

Die Ränder des Labrador Meeres wurden während des späten Neoproterozoikums intensiv von karbonatreichen silikatischen Schmelzen durchsetzt. Diese Schmelzen bildeted sich bei Drucken zwischen ca. 4-6 GPa (ca. 120-180 km Tiefe) an der Basis der kontinentalen Mantel-Lithosphäre. Diese Magmengenerierung steht in zeitlichem und räumlichem Zusammenhang mit kontinentalen Extensionsprozessen, welche zu beiden Seiten des sich öffnenden Iapetus-Ozeans auftraten.

Dynamik und Klimatologie von diabatischen Rossby-Wellen

Der Wintersturm Lothar zog am 26. Dezember 1999 über Europa und richtete in Frankreich, in Deutschland, in der Schweiz und in Österreich ungewöhnlich hohe Schäden an. Lothar entstand aus einer diabatischen Rossby Welle (DRW) und erreichte erst wenige Stunden vor dem europäischen Kontinent Orkanstärke. DRWs weisen ein interessantes atmosphärisches Strömungsmuster auf. Sie bestehen aus einer positiven PV-Anomalie in der unteren Troposphäre, die sich in einer Region mit starkem meridionalen Temperaturgradient befindet. Die positive PV-Anomalie löst eine zyklonale Strömung aus, dadurch wird östlich der PV-Anomalie warme Luft aus dem Süden herantransportiert. Während des Aufstieg der warmen Luft finden diabatische Prozesse statt, die zur Bildung einer neuen positiven PV-Anomalie in der unteren Troposphäre (PVA) führen. DRWs entstehen unabhängig von PV-Anomalien an der Tropopause. Falls sie jedoch mit ihnen in Wechselwirkung treten, kann - wie im Falle von Lothar - eine explosive Zyklogenese daraus resultieren. Im ersten Teil wird die Dynamik einer DRW am Beispiel des Wintersturms Lothar untersucht. Es wird insbesondere auf das Potential einer DRW zur explosiven Zyklogenese eingegangen. Im zweiten Teil wird das Aufretreten von DRWs in ECMWF-Vorhersagen untersucht. Es werden Unterschiede zwischen DRWs und anderen PV-Anomalien in der unteren Troposphäre hervorgehoben. Die Dynamik von DRWs wird mit Hilfe eines ECMWF-"Ensemble Prediction System" (EPS) des Wintersturms Lothar untersucht. Die 50 Modellläufe des EPS starten am 24. Dezember 1999 um 12 UTC und reichen bis zum 26. Dezember 1999 um 12 UTC. Nur 16 der 50 Modellläufe sagen einen ähnlich starken Sturm wie Lothar vorher. 10 Modellläufen sagen am 26. Dezember keine Zyklone mehr vorher. Die Ausprägung der baroklinen Zone, in der sich die DRW befindet, ist ausschlaggebend für die Intensität der DRW. Weitere wichtige Parameter sind der Feuchtegehalt der unteren Troposphäre und der latente Wärmefluss über dem Ozean. Diejenigen DRWs, die sich zu am 25. Dezember um 12 UTC näher als 400 km am Tropopausenjet befinden, entwickeln sich zu einer starken Zyklone. Alle anderen lösen sich auf oder bleiben schwache Zyklonen. Es ist schwierig, diabatische Prozesse in Wettervorhersagemodellen abzubilden, dementsprechend treten Schwierigkeiten bei der Vorhersage von PVAs auf. In den operationellen ECMWF-Vorhersagen von Juni 2004 bis Mai 2005 werden mit Hilfe eines Tracking- Algorithmus PVAs im Nordpazifik und Nordatlantik bestimmt und in fünf Kategorien eingeteilt. Die fünf Kategorien unterscheiden sich in ihrer Häufigkeit, ihrer Zugbahn und ihrer Gestalt. Im Nordpazifik entstehen doppelt so viele PVAs wie im Nordatlantik. Durchschnittlich werden im Winter weniger PVAs gefunden als im Sommer. Die Baroklinität und die Geschwindigkeit des Tropopausenjets ist in der Nähe von DRWs besonders hoch. Verglichen mit anderen PVAs weisen DRWs eine ähnliche Verteilung des reduzierten Bodendrucks auf. DRWs können in etwa gleich gut vorhergesagt werden wie andere PVAs.

The bursting behavior of gas slugs: laboratory and analytical insights into Strombolian volcanic eruptions.

The aim of this thesis is to study how explosive behavior and geophysical signals in a volcanic conduit are related to the development of overpressure in slug-driven eruptions. A first suite of laboratory experiments of gas slugs ascending in analogue conduits was performed. Slugs ascended into a range of analogue liquids and conduit diameters to allow proper scaling to the natural volcanoes. The geometrical variation of the slug in response to the explored variables was parameterised. Volume of gas slug and rheology of the liquid phase revealed the key parameters in controlling slug overpressure at bursting. Founded on these results, a theoretical model to calculate burst overpressure for slug-driven eruptions was developed. The dimensionless approach adopted allowed to apply the model to predict bursting pressure of slugs at Stromboli. Comparison of predicted values with measured data from Stromboli volcano showed that the model can explain the entire spectrum of observed eruptive styles at Stromboli – from low-energy puffing, through normal Strombolian eruptions, up to paroxysmal explosions – as manifestations of a single underlying physical process. Finally, another suite of laboratory experiments was performed to observe oscillatory pressure and forces variations generated during the expansion and bursting of gas slugs ascending in a conduit. Two end-member boundary conditions were imposed at the base of the pipe, simulating slug ascent in closed base (zero magma flux) and open base (constant flux) conduit. At the top of the pipe, a range of boundary conditions that are relevant at a volcanic vent were imposed, going from open to plugged vent. The results obtained illustrate that a change in boundary conditions in the conduit concur to affect the dynamic of slug expansion and burst: an upward flux at the base of the conduit attenuates the magnitude of the pressure transients, while a rheological stiffening in the top-most region of conduit changes dramatically the magnitude of the observed pressure transients, favoring a sudden, and more energetic pressure release into the overlying atmosphere. Finally, a discussion on the implication of changing boundary on the oscillatory processes generated at the volcanic scale is also given.

Deciphering petrological signatures of reactive melt stagnation and cooling in the oceanic mantle underneath ultraslow-spreading ridges

The global mid-ocean ridge system creates oceanic crust and lithosphere that covers more than two-thirds of the Earth. Basalts are volumetrically the most important rock type sampled at mid-ocean ridges. For this reason, our present understanding of upper mantle dynamics and the chemical evolution of the earth is strongly influenced by the study of mid-ocean ridge basalts (MORB). However, MORB are aggregates of polybarically generated small melt increments that can undergo a variety of physical and chemical processes during their ascent and consequently affect their derivative geochemical composition. Therefore, MORB do not represent “direct” windows to the underlying upper mantle. Abyssal peridotites, upper mantle rocks recovered from the ocean floor, are the residual complement to MORB melting and provide essential information on melt extraction from the upper mantle. In this study, abyssal peridotites are examined to address these overarching questions posed by previous studies of MORB: How are basaltic melts formed in the mantle, how are they extracted from the mantle and what physical and chemical processes control mantle melting? The number of studies on abyssal peridotites is small compared to those on basalts, in part because seafloor exposures of abyssal peridotites are relatively rare. For this reason, abyssal peridotite characteristics need to be considered in the context of subaerially exposed peridotites associated with ophiolites, orogenic peridotite bodies and basalt-hosted xenoliths. However, orogenic peridotite bodies are mainly associated with passive continental margins, most ophiolites are formed in supra-subduction zone settings, and peridotite xenoliths are often contaminated by their host magma. Therefore, studies of abyssal peridotites are essential to understanding the primary characteristics of the oceanic upper mantle free from the influence of continental rifting, subduction and tectonic emplacement processes. Nevertheless, numerous processes such as melt stagnation and cooling-induced, inter-mineral exchange can affect residual abyssal peridotite compositions after the cessation of melting. The aim of this study is to address these post-melting modifications of abyssal peridotites from a petrological-geochemical perspective. The samples in this study were dredged along the axis of the ultraslow-spreading Gakkel Ridge in the Arctic Ocean within the “Sparsely Magmatic Zone”, a 100 km ridge section where only mantle rocks are exposed. During two expeditions (ARK XVII-2 in 2001 and ARK XX-2 in 2004), exceptionally fresh peridotites were recovered. The boulders and cobbles collected cover a range of mantle rock compositions, with most characterized as plagioclase-free spinel peridotites or plagioclase- spinel peridotites. This thesis investigates melt stagnation and cooling processes in the upper mantle and is divided into two parts. The first part focuses on processes in the stability field of spinel peridotites (>10 kb) such as melt refertilization and cooling related trace element exchange, while the second part investigates processes in the stability field of plagioclase peridotites (< 10 kb) such as reactive melt migration and melt stagnation. The dissertation chapters are organized to follow the theoretical ascent of a mantle parcel upwelling beneath the location where the samples were collected.