Possible Effects of Synaptic Imbalances on Oligodendrocyte–Axonic Interactions in Schizophrenia: A Hypothetical Model

A model of glial–neuronal interactions is proposed that could be explanatory for the demyelination identified in brains with schizophrenia. It is based on two hypotheses: (1) that glia–neuron systems are functionally viable and important for normal brain function, and (2) that disruption of this postulated function disturbs the glial categorization function, as shown by formal analysis. According to this model, in schizophrenia receptors on astrocytes in glial–neuronal synaptic units are not functional, loosing their modulatory influence on synaptic neurotransmission. Hence, an unconstrained neurotransmission flux occurs that hyperactivates the axon and floods the cognate receptors of neurotransmitters on oligodendrocytes. The excess of neurotransmitters may have a toxic effect on oligodendrocytes and myelin, causing demyelination. In parallel, an increasing impairment of axons may disconnect neuronal networks. It is formally shown how oligodendrocytes normally categorize axonic information processing via their processes. Demyelination decomposes the oligodendrocyte–axonic system making it incapable to generate categories of information. This incoherence may be responsible for symptoms of disorganization in schizophrenia, such as thought disorder, inappropriate affect and incommunicable motor behavior. In parallel, the loss of oligodendrocytes affects gap junctions in the panglial syncytium, presumably responsible for memory impairment in schizophrenia

Entropy of Generating Series for Nonlinear Input-Output Systems and their Interconnections

This paper has two main objectives. The first is to introduce a notion of entropy that is well suited for the analysis of nonlinear input-output systems that have a Chen-Fliess series representation. The latter is defined in terms of its generating series over a noncommutative alphabet. The idea is to assign an entropy to a generating series as an element of a graded vector space. The second objective is to describe the entropy of generating series originating from interconnected systems of Chen-Fliess series that arise in the context of control theory. It is shown that one set of interconnections can never increase entropy as defined here, while a second set has the potential to do so. The paper concludes with a brief introduction to an entropy ultrametric space and some open questions

A lived experience theory of schism (LETS): Exploring the complex social dynamics powering factionalised conflict in nonprofit organisations

Schism is a widespread phenomenon of social groups which has persisted over centuries. An intense form of factionalised conflict, schism can be distressing for people to experience and challenging for groups to navigate. Schism research has roots in anthropology, organisation studies, and social psychology, and has been studied in societies, religions, social movements, political parties, nonprofit organisations, and other contexts. Despite broad and enduring relevance to social organising, schism research is surprisingly scant. Across disciplines and contexts, findings are disjointed and contradictory. No widely accepted definition or theory of schism was found in the literature. The aim of the current research was to gain insight into the social dynamics powering the incidence, progression, and lived experience of schism. The goal was to increase human agency and control in schism based on emerging theoretical knowledge, and thereby improve experiences and outcomes for people and organisations. A qualitative study of schism in nonprofit organisations in Western Australia was undertaken using an exploratory qualitative research design and a lived experience lens. Participant-centred interviews were conducted, typically of 1 hour, with 41 people who described schisms in 24 organisations. Sampling was initially by convenience then purposive snowball sampling, enabling a range of organisations, roles, and experiences to be represented. Interviews were transcribed to form a rich primary data set. Systematic coding and thematic analysis complemented immersion in individual stories. Data collection, data analysis, and theory development were iterative and interdependent. Emerging themes forced problematisation of prior knowledge. The ongoing process of theory construction employed both inductive and abductive reasoning. A novel conceptualisation of schism emerged from this research project, representing schism as a complex social construction in an open system rather than a linear process in a bounded system, and privileging the human experience over the organisation as the entity of concern. A new definition of schism is proposed which provides a foundation for the lived experience theory of schism (LETS) presented in this thesis. Together, the definition and theory contribute to knowledge of schism in organisations and other social systems, and provide a foundation for future schism research. Findings from this project have implications for nonprofit sector policy and practice, especially in group leadership and governance

Digital Discovery of 100 diverse Quantum Experiments with PyTheus

Photons are the physical system of choice for performing experimental tests of the foundations of quantum mechanics. Furthermore, photonic quantum technology is a main player in the second quantum revolution, promising the development of better sensors, secure communications, and quantum-enhanced computation. These endeavors require generating specific quantum states or efficiently performing quantum tasks. The design of the corresponding optical experiments was historically powered by human creativity but is recently being automated with advanced computer algorithms and artificial intelligence. While several computer-designed experiments have been experimentally realized, this approach has not yet been widely adopted by the broader photonic quantum optics community. The main roadblocks consist of most systems being closed-source, inefficient, or targeted to very specific use-cases that are difficult to generalize. Here, we overcome these problems with a highly-efficient, open-source digital discovery framework PyTheus, which can employ a wide range of experimental devices from modern quantum labs to solve various tasks. This includes the discovery of highly entangled quantum states, quantum measurement schemes, quantum communication protocols, multi-particle quantum gates, as well as the optimization of continuous and discrete properties of quantum experiments or quantum states. PyTheus produces interpretable designs for complex experimental problems which human researchers can often readily conceptualize. PyTheus is an example of a powerful framework that can lead to scientific discoveries -- one of the core goals of artificial intelligence in science. We hope it will help accelerate the development of quantum optics and provide new ideas in quantum hardware and technology

P-T evolotion and High-temperature deformation of Precambrian eclogite, Sveconorwegian orogen

The 1.1-0.9 Ga Sveconorwegian orogen is one of several Grenvillian-aged orogenic belts that mark the amalgamation of supercontinent Rodinia. The highest-pressure rocks in the Sveconorwegian orogen are eclogites in the Eastern Segment (SW Sweden). The eclogites occur in a nappe in the high-grade metamorphic level of the Eastern Segment that represents a window into the deepest part of this Precambrian mountain belt. The aim of this thesis is to reconstruct the metamorphic history of the eclogite-bearing nappe by characterizating the deformation associated with exhumation (Paper I) and by reconstructing the P–T evolution (pressure and temperature; papers II and III).Paper I focuses on the deformation structures in the basal shear zone of the eclogite-bearing nappe. These structures developed during exhumation at high-temperature conditions. Top-to-the-east shear and east-directed flow produced intense folding, interpreted as formed by a combination of simple and pure shear. The interplay of shearing, folding, and melt localization lead to localized shear, high-temperature brittle fracturing, and the formation of high-temperature chevron folds in high-strain zones.Paper II retraces the metamorphic evolution of the eclogite-bearing nappe by thermodynamic modelling (THERMOCALC©) and construction of P–T pseudosections for two different types of eclogite. One of the samples gave information on both the prograde and the retrograde paths, and an estimate of peak metamorphic conditions of 850–900 °C and ~18 kbar. The first stage of the prograde path, representing a medium P/T gradient, is recorded in the core of garnet grains. The second part of the prograde path and the retrograde path are both steep. The chemical growth zoning of garnet is preserved which, together with the shape of the P–T path, reflects short residence time at high temperatures.Paper III reports the results of two independent trace element thermometers, which are based on the Zr-contents in rutile and Ti-contents in quartz. The combination of these two methods confirmed the P–T evolution calculated in Paper II. In particular, Ti-in-quartz thermometry are in agreement with the pseudosection estimates at high temperatures, and the minerals appear unaffected by diffusional resetting. A pseudosection model, showing the changes in modal abundance of different phases along the P–T path, demonstrates that rutile grains in the matrix recrystallized from smaller-sized rutile grains, and that this process was simultaneous with the main dehydration reaction in the rock (continuous breakdown of hornblende and formation of clinopyroxene). This study illustrates that Zr-in-rutile and Ti-in-quartz thermometry cannot only robustly constrain a prograde evolution, but when combined with a pseudosection model can also yield information on recrystallization processes. In fact, the combination of these methods provides an unrivalled tool for petrologic interpretation.The data presented in this thesis testifies to westward tectonic burial of continental crust at ~65 km depth and 890 °C at a late stage of the Sveconorwegian orogenesis. The following foreland-directed tectonic exhumation of the eclogite-bearing nappe was associated with partial melting, ductile flow folding and shearing. The character of both prograde and retrograde P–T paths suggests rapid tectonic burial and exhumation consistent with collision at the end of the Sveconorwegian orogeny

Institutional change in Russian corporate governance: an analysis of corporate disputes

Russia has been lagging behind most of the developed countries and some of the transition economies in terms of the corporate governance infrastructure (Woodruff, 2004). However, the challenge to develop strategic assets, particularly in the form of oil and gas reserves, produced the need to attract foreign capital and expertise. This in turn has led to a mounting pressure to improve fundamental characteristics of corporate governance such as the regulatory environment, enforcement mechanisms, corporate structure and transparency (Preobragenskaya, 2004). Since strategic assets are at the very heart of the still undiversified Russian economy, it is easy to see how corporate governance has become one of the top priorities on the agenda of national reforms (EU-Russia Roundtable on Corporate Governance, 2006). This study attempts to register the perceived change in the institutional context in Russia through analysing reported corporate disputes. Thematic template analysis is applied to the data on corporate conflicts taken from the English language Russian press. The results of the study suggest a positive change in perception about the role of formal institutions with reference to private entities and a negative change in terms of perception in relation to state entities. This conclusion is based on the comparison of corporate disputes and enforcement practices employed by the parties to corporate disputes reported in 1998 and 2006. On an academic level this study addresses a call in the literature to give more consideration to the particularities of the management environment and the fragility of its social systems in Russia (Kuznetsov & Kuznetsova, 2001) as well as complement understanding of Russian corporate governance by concentrating on the in-depth analysis of company behaviour (Iwasaki, 2007)