Bayes Factors Based on Test Statistics

Traditionally, the use of Bayes factors has required the specification of proper prior distributions on model parameters implicit to both null and alternative hypotheses. In this paper, I describe an approach to defining Bayes factors based on modeling test statistics. Because the distributions of test statistics do not depend on unknown model parameters, this approach eliminates the subjectivity normally associated with the definition of Bayes factors. For standard test statistics, including the _2, F, t and z statistics, the values of Bayes factors that result from this approach can be simply expressed in closed form.

VIRTOPSY - the Swiss virtual autopsy approach

The aim of the VIRTOPSY project () is utilizing radiological scanning to push low-tech documentation and autopsy procedures in a world of high-tech medicine in order to improve scientific value, to increase significance and quality in the forensic field. The term VIRTOPSY was created from the terms virtual and autopsy: Virtual is derived from the Latin word 'virtus', which means 'useful, efficient and good'. Autopsy is a combination of the old Greek terms 'autos' (=self) and 'opsomei' (=I will see). Thus autopsy means 'to see with ones own eyes'. Because our goal was to eliminate the subjectivity of "autos", we merged the two terms virtual and autopsy - deleting "autos" - to create VIRTOPSY. Today the project VIRTOPSY combining the research topics under one scientific umbrella, is characterized by a trans-disciplinary research approach that combines Forensic Medicine, Pathology, Radiology, Image Processing, Physics, and Biomechanics to an international scientific network. The paper will give an overview of the Virtopsy change process in forensic medicine.

Computational study of internal and external condensing flows and experimental synthesis to investigate their attainability and stability in ground-based and space-based environments

This doctoral thesis presents the computational work and synthesis with experiments for internal (tube and channel geometries) as well as external (flow of a pure vapor over a horizontal plate) condensing flows. The computational work obtains accurate numerical simulations of the full two dimensional governing equations for steady and unsteady condensing flows in gravity/0g environments. This doctoral work investigates flow features, flow regimes, attainability issues, stability issues, and responses to boundary fluctuations for condensing flows in different flow situations. This research finds new features of unsteady solutions of condensing flows; reveals interesting differences in gravity and shear driven situations; and discovers novel boundary condition sensitivities of shear driven internal condensing flows. Synthesis of computational and experimental results presented here for gravity driven in-tube flows lays framework for the future two-phase component analysis in any thermal system. It is shown for both gravity and shear driven internal condensing flows that steady governing equations have unique solutions for given inlet pressure, given inlet vapor mass flow rate, and fixed cooling method for condensing surface. But unsteady equations of shear driven internal condensing flows can yield different “quasi-steady” solutions based on different specifications of exit pressure (equivalently exit mass flow rate) concurrent to the inlet pressure specification. This thesis presents a novel categorization of internal condensing flows based on their sensitivity to concurrently applied boundary (inlet and exit) conditions. The computational investigations of an external shear driven flow of vapor condensing over a horizontal plate show limits of applicability of the analytical solution. Simulations for this external condensing flow discuss its stability issues and throw light on flow regime transitions because of ever-present bottom wall vibrations. It is identified that laminar to turbulent transition for these flows can get affected by ever present bottom wall vibrations. Detailed investigations of dynamic stability analysis of this shear driven external condensing flow result in the introduction of a new variable, which characterizes the ratio of strength of the underlying stabilizing attractor to that of destabilizing vibrations. Besides development of CFD tools and computational algorithms, direct application of research done for this thesis is in effective prediction and design of two-phase components in thermal systems used in different applications. Some of the important internal condensing flow results about sensitivities to boundary fluctuations are also expected to be applicable to flow boiling phenomenon. Novel flow sensitivities discovered through this research, if employed effectively after system level analysis, will result in the development of better control strategies in ground and space based two-phase thermal systems.

Slope stability analysis of the Pacaya Volcano, Guatemala, using limit equilibrium and finite element method

The Pacaya volcanic complex is part of the Central American volcanic arc, which is associated with the subduction of the Cocos tectonic plate under the Caribbean plate. Located 30 km south of Guatemala City, Pacaya is situated on the southern rim of the Amatitlan Caldera. It is the largest post-caldera volcano, and has been one of Central America’s most active volcanoes over the last 500 years. Between 400 and 2000 years B.P, the Pacaya volcano had experienced a huge collapse, which resulted in the formation of horseshoe-shaped scarp that is still visible. In the recent years, several smaller collapses have been associated with the activity of the volcano (in 1961 and 2010) affecting its northwestern flanks, which are likely to be induced by the local and regional stress changes. The similar orientation of dry and volcanic fissures and the distribution of new vents would likely explain the reactivation of the pre-existing stress configuration responsible for the old-collapse. This paper presents the first stability analysis of the Pacaya volcanic flank. The inputs for the geological and geotechnical models were defined based on the stratigraphical, lithological, structural data, and material properties obtained from field survey and lab tests. According to the mechanical characteristics, three lithotechnical units were defined: Lava, Lava-Breccia and Breccia-Lava. The Hoek and Brown’s failure criterion was applied for each lithotechnical unit and the rock mass friction angle, apparent cohesion, and strength and deformation characteristics were computed in a specified stress range. Further, the stability of the volcano was evaluated by two-dimensional analysis performed by Limit Equilibrium (LEM, ROCSCIENCE) and Finite Element Method (FEM, PHASE 2 7.0). The stability analysis mainly focused on the modern Pacaya volcano built inside the collapse amphitheatre of “Old Pacaya”. The volcanic instability was assessed based on the variability of safety factor using deterministic, sensitivity, and probabilistic analysis considering the gravitational instability and the effects of external forces such as magma pressure and seismicity as potential triggering mechanisms of lateral collapse. The preliminary results from the analysis provide two insights: first, the least stable sector is on the south-western flank of the volcano; second, the lowest safety factor value suggests that the edifice is stable under gravity alone, and the external triggering mechanism can represent a likely destabilizing factor.

A STUDY OF THE IMPACTS OF FREEZE-THAW ON CLIFF RECESSION AT THE CALVERT CLIFFS IN CALVERT COUNTY, MARYLAND

The Calvert Cliffs, which form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, are actively eroding and destabilizing, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have identified that where waves directly interact with the toe of the slope, wave action controls cliff recession; however, where waves do not regularly interact with the slope toe, the past work identified that freeze-thaw controls recession. This study investigated the validity of this second claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the Calvert Cliffs that are not directly affected by waves. While waves do remove failed material from the toe, in these regions freeze-thaw is believed to be the dominant factor driving recession at the Calvert Cliffs. Past recession rates were calculated using historical aerial photographs and were analyzed together with a number of other variables selected to represent the freeze-thaw behavior of the Calvert Cliffs. The investigation studied sixteen independent variables and found that over 65% of recession at these study sites can be represented by the following five variables: (1) cliff face direction, (2 and 3) the percent of total cliff height composed of soil with freeze-thaw susceptibility F4 and F2, (4) the number of freeze-thaw cycles, and (5) the weighted shear strength. Future mitigation techniques at these sites should focus on addressing these variables and might include vegetation or addressing the presence of water along the face of the slope. Unmitigated, the Calvert Cliffs will continue to recede until a stable slope angle is reached and maintained.

Blighted Spaces and the Politics of Everyday Life

While a great deal is known about the demographic and historical trends that shape the built environment of American cities, much less is known about the politics of everyday life among residents who continue to live in postindustrial neighborhoods. This study seeks to compensate for the current gaps in academic research by conducting spatially informed ethnography in a North Philadelphia community. Specifically, the study will explore the issue of urban "blight" from a cultural geography perspective, primarily by looking at the ways in which "blighted" spaces shape everyday life, and everyday life in turn shapes and produces the spatial environment. In response to these concerns, my study poses the questions: What would it mean to focus on the ways in which human agency, imagination, and subjectivity are shaped by "blighted" geographical locations? What would it mean to pay ethnographic attention to how subjects in given historical conditions are shaped by "blighted" spaces, as well as how they respond to these spaces in culturally specific ways? By incorporating critical interdisciplinary approaches, this study offers a new way of looking at the various practices of daily life - including flexible, informal economic activities and post-welfare related "lifestyles" of resistance. Through the lens of spatial ethnography, the study seeks to elucidate the ways in which postindustrial space interacts with culture, poverty and addiction; as well as the ways in which users continue to appropriate postindustrial spaces in culturally meaningful ways under the aegis of the semi-welfare state.

Dutch boundaries

In many schools of architecture the 1970s have been an important watershed for the way in which architecture was taught. For example, recent studies have stressed the importance of Aldo Rossi for the changes in the teaching of architec-ture at the ETH in Zürich that before was based on orthodox modern principles. A similar struggle between an orthodox conception of modernity and its criticism took place at the architectural faculty of Delft, in the Netherlands. Although Delft is an important European school of architecture, the theoretical work produced during this period is not largely known outside the Netherlands. This is perhaps due to the fact that most studies were published in Dutch. With this article, I intend to make the architectural theory developed during this period known to a larger public. The article describes the intellectual journey made by Dutch stu-dents of architecture in the 1970s and 1980s. This was the quest to receive recognition for the intellectual substance of architecture: the insight architecture could be a discourse and a form of knowledge and not only a method of building. Specifically, the work of the architectural theoretician Wim Nijenhuis is highlight-ed. However, as I point out in this article, the results of this journey also had its problematic sides. This becomes clear from the following sentence taken from the dissertation of Wim Nijenhuis: "The search for metaphysical fiction and the tendency towards a technological informed absolute through fully transparent and simultaneous information, should be contested by a fantasy dimension, that does not wish to 'overcome' a given situation and that does not rely on 'creativi-ty' (that would still be historical and humanistic)." Texts like this have a hermet-ic quality that is not easy to comprehend for an architectural public. Even more, there is an important debate looming behind these sentences. As an important outcome of their quest the architectural students in Delft asked themselves: how do we give form to architectural theory once its claim to truth is exposed as an illusion? For Nijenhuis, the discourse about architecture is a mere 'artful game with words': a fiction, besides other forms of fiction like poetry or literature. The question is then if we have not entered the realm of total subjectivity and relativ-ism with this position. From what can the discourse of architecture derive its authority after the death of God?

Individual and structural factors of member commitment in sports clubs

This article analyses the conditions influencing the commitment of members of sports clubs. It focuses not only on individual characteristics of members, but also on the corresponding structural conditions of sports clubs related to the individual decision to quit or continue their membership. The influences of both the individual and context levels on the commitment of members are estimated in different multi-level models. Results of these multi-level analyses indicate that commitment of members is not just an outcome of individual characteristics such as strong commitment to the club, positively perceived communication and cooperation, satisfaction with sports clubsʼ offers, or voluntary engagement. It is also influenced by club-specific structural conditions: commitment is more probable in rural sports clubs, and clubs who explicitly support sociability, whereas success-oriented sporting goals in clubs have a destabilizing effect.

Molecular Determinants Defining the Triggering Range of Prefusion F Complexes of Canine Distemper Virus

The morbillivirus cell entry machinery consists of a fusion (F) protein trimer that refolds to mediate membrane fusion following receptor-induced conformational changes in its binding partner, the tetrameric attachment (H) protein. To identify molecular determinants that control F refolding, we generated F chimeras between measles virus (MeV) and canine distemper virus (CDV). We located a central pocket in the globular head domain of CDV F that regulates the stability of the metastable, prefusion conformational state of the F trimer. Most mutations introduced into this "pocket'" appeared to mediate a destabilizing effect, a phenotype associated with enhanced membrane fusion activity. Strikingly, under specific triggering conditions (i.e., variation of receptor type and H protein origin), some F mutants also exhibited resistance to a potent morbillivirus entry inhibitor, which is known to block F triggering by enhancing the stability of prefusion F trimers. Our data reveal that the molecular nature of the F stimulus and the intrinsic stability of metastable prefusion F both regulate the efficiency of F refolding and escape from small-molecule refolding blockers. IMPORTANCE: With the aim to better characterize the thermodynamic basis of morbillivirus membrane fusion for cell entry and spread, we report here that the activation energy barrier of prefusion F trimers together with the molecular nature of the triggering "stimulus" (attachment protein and receptor types) define a "triggering range," which governs the initiation of the membrane fusion process. A central "pocket" microdomain in the globular F head contributes substantially to the regulation of the conformational stability of the prefusion complexes. The triggering range also defines the mechanism of viral escape from entry inhibitors and describes how the cellular environment can affect membrane fusion efficiency.

Mutations affecting beta-tubulin folding and degradation.

Revertants of a colcemid-resistant Chinese hamster ovary cell line with an altered (D45Y) beta-tubulin have allowed the identification of four cis-acting mutations (L187R, Y398C, a 12-amino acid in-frame deletion, and a C-terminal truncation) that act by destabilizing the mutant tubulin and preventing it from incorporating into microtubules. These unstable beta-tubulins fail to form heterodimers and are predominantly found in association with the chaperonin CCT, suggesting that they cannot undergo productive folding. In agreement with these in vivo observations, we show that the defective beta-tubulins do not stably interact with cofactors involved in the tubulin folding pathway and, hence, fail to exchange with beta-tubulin in purified alphabeta heterodimers. Treatment of cells with MG132 causes an accumulation of the aberrant tubulins, indicating that improperly folded beta-tubulin is degraded by the proteasome. Rapid degradation of the mutant tubulin does not elicit compensatory changes in wild-type tubulin synthesis or assembly. Instead, loss of beta-tubulin from the mutant allele causes a 30-40% decrease in cellular tubulin content with no obvious effect on cell growth or survival.

Der erste Mord. Der Tod des Apsyrtos als Schlüsselmoment für moderne Interpretationen des Medea-Mythos: Jahnn, Pasolini, Wolf, Loher

Murderous Medea – following Euripides’ seminal tragedy countless authors and artists have depicted Medea as child-slaughtering outlaw and avenger. But the Medea myth is much more diverse and holds more depth than this. Medea’s path through her career as princess, magician, wife, mother and avengress opens with another abominable death: that of her brother Apsyrtos. This article focuses on how and why the death of Medea’s brother Apsyrtos has been examined and instrumentalised in modern adaptions of the myth by Hans Henny Jahnn, Pier Paolo Pasolini, Christa Wolf and Dea Loher. Whether guilty as charged but with sensible intentions to gain self-rule and show herself trustworthy or innocent of crime or murder but stricken with guilt and alienation, Medea’s involvement in her brother’s death seems to hold the key to modern interpretations of antiquity’s different strands of the Medea myth and its adaptability to modern concerns of subjectivity and emancipation.

Structure/affinity studies in the bicyclo-DNA series: Synthesis and properties of oligonucleotides containing bcen-T and iso-tricyclo-T nucleosides

We present the synthesis of the two novel nucleosides iso-tc-T and bcen-T, belonging to the bicyclo-/tricyclo-DNA molecular platform. In both modifications the torsion around C6’–C7’ within the carbocyclic ring is planarized by either the presence of a C6’–C7’ double bond or a cyclopropane ring. Structural analysis of these two nucleosides by X-ray analysis reveals a clear preference of torsion angle γ for the gauche orientation with the furanose ring in a near perfect 2’-endo conformation. Both modifications were incorporated into oligodeoxynucleotides and their thermal melting behavior with DNA and RNA as complements was assessed. We found that the iso-tc-T modification was significantly more destabilizing in duplex formation compared to the bcen-T modification. In addition, duplexes with complementary RNA were less stable as compared to duplexes with DNA as complement. A structure/affinity analysis, including the already known bc-T and tc-T modifications, does not lead to a clear correlation of the orientation of torsion angle γ with DNA or RNA affinity. There is, however, some correlation between furanose conformation (N- or S-type) and affinity in the sense that a preference for a 3’-endo like conformation is associated with a preference for RNA as complement. As a general rule it appears that Tm data of single modifications with nucleosides of the bicyclo-/tricyclo-DNA platform within deoxyoligonucleotides are not predictive for the stability of fully modified oligonucleotides.

Rethinking science for sustainable development: Reflexive interaction for a paradigm transformation

If we postulate a need for the transformation of society towards sustainable development, we also need to transform science and overcome the fact/value split that makes it impossible for science to be accountable to society. The orientation of this paradigm transformation in science has been under debate for four decades, generating important theoretical concepts, but they have had limited impact until now. This is due to a contradictory normative science policy framing that science has difficulties dealing with, not least of all because the dominant framing creates a lock-in. We postulate that in addition to introducing transdisciplinarity, science needs to strive for integration of the normative aspect of sustainable development at the meta-level. This requires a strategically managed niche within which scholars and practitioners from many different disciplines can engage in a long-term common learning process, in order to become a “thought collective” (Fleck) capable of initiating the paradigm transformation. Arguing with Piaget that “decentration” is essential to achieve normative orientation and coherence in a learning collective, we introduce a learning approach—Cohn's “Theme-Centred Interaction”—which provides a methodology for explicitly working with the objectivity and subjectivity of statements and positions in a “real-world” context, and for consciously integrating concerns of individuals in their interdependence with the world. This should enable a thought collective to address the epistemological and ethical barriers to science for sustainable development.

Institutions as key drivers of collective action in WUAs [Water User Associations] of Uzbekistan

This paper presents a multifactor approach for performance assessment of Water Users Associations (WUAs) in Uzbekistan in order to identify the drivers for improved and effi cient performance of WUAs. The study was carried out in the Fergana Valley where the WUAs were created along the South Fergana Main Canal during the last 10 years. The farmers and the employees of 20 WUAs were questioned about the WUAs’ activities and the quantitative and qualitative data were obtained. This became a base for the calculation of 36 indicators divided into 6 groups: Water supply, technical conditions, economic conditions, social and cultural conditions, organizational conditions and information conditions. All the indicators assessed with a differentiated point system adjusted for subjectivity of several of them give the total maximal result for the associations of 250 point. The WUAs of the Fergana Valley showed the score between 145 and 219 points, what refl ects a highly diverse level of the WUAs performance in the region. The analysis of the indicators revealed that the key points of the WUA’s success are the organizational and institutional conditions including the participatory factors and awareness of both the farmers and employees about the work of WUA. The research showed that the low performance of the WUAs is always explained by the low technical and economic conditions along with weak organization and information dissemination conditions. It is clear that it is complicated to improve technical and economic conditions immediately because they are cost-based and cost-induced. However, it is possible to improve the organizational conditions and to strengthen the institutional basis via formal and information institutions which will gradually lead to improvement of economic and technical conditions of WUAs. Farmers should be involved into the WUA Governance and into the process of making common decisions and solving common problems together via proper institutions. Their awareness can also be improved by leading additional trainings for increasing farmers’ agronomic and irrigation knowledge, teaching them water saving technologies and acquainting them with the use of water measuring equipment so it can bring reliable water supply, transparent budgeting and adequate as well as equitable water allocation to the water users.