Path Integration Changes as a Cognitive Marker for Vascular Cognitive Impairment?—A Pilot Study

Path integration spatial navigation processes are emerging as promising cognitive markers for prodromal and clinical Alzheimer’s disease (AD). However, such path integration changes have been less explored in Vascular Cognitive Impairment (VCI), despite neurovascular change being a major contributing factor to dementia and potentially AD. In particular, the sensitivity and specificity of path integration impairments in VCI compared to AD is unclear. In the current pilot study, we explore path integration performance in early-stage AD and VCI patient groups and hypothesize that: (i) medial parietal mediated egocentric processes will be more affected in VCI; and (ii) medial temporal mediated allocentric processes will be more affected in AD. This cross-sectional study included early-stage VCI patients (n = 9), AD patients (n = 10) and healthy age-matched controls (n = 20). All participants underwent extensive neuropsychological testing, as well as spatial navigation testing. The spatial navigation tests included the virtual reality “Supermarket” task assessing egocentric (body-based) and allocentric (map-based) navigation as well as the “Clock Orientation” test assessing egocentric and path integration processes. Results showed that egocentric integration processes are only impaired in VCI, potentially distinguishing it from AD. However, in contrast to our prediction, allocentric integration was not more impaired in AD compared to VCI. These preliminary findings suggest limited specificity of allocentric integration deficits between VCI and AD. By contrast, egocentric path integration deficits emerge as more specific to VCI, potentially allowing for more specific diagnostic and treatment outcome measures for vascular impairment in dementia

Legitimizing Elections Through the Regulation of Campaign Financing: A Comparative Constitutional Analysis and Hope for South Africa

Actual or apparent corruption can seriously undermine any democratic system. This Article examines two approaches to tackling this problem in South Africa. The libertarian approach, used in the United States, embodies a strong presumption against regulation of campaign financing on the basis that it is a violation of the constitutional rights to free speech and association. The weak regulations that result from this system do little to stem the influence of a powerful few on the outcomes of national elections. A better approach for South Africa is the egalitarian model, used in both the United Kingdom and Canada. This model focuses on leveling the playing field for participants. Under this model, rights are subject to greater regulation so long as the government can provide sufficient justification. South Africa’s current system, by requiring proportional national funding of political parties, but leaving private financing largely unregulated, has resulted in a virtual one-party state in which private funding dominates. To solve these problems, South Africa should embrace the egalitarian model by implementing spending caps and increasing transparency

Expert elicitation, professional judgement, and current exposure assessment practices in the field of occupational hygiene

Occupational hygienists work across a diverse range of industrial environments. In the course of their work, hygienists will need to assess and control worker exposure levels by deploying methods based on the science of risk management, exposure assessment and industrial safety. Hygienists will regularly make decisions relating to worker exposure based on professional judgement, usually in the absence of quantitative data and in the presence of high uncertainty. These factors have the potential to lead to heterogeneity between practitioners, bias, error, and practice variation in the form of departure from established guidelines or protocols. The primary aim of this PhD research project was to examine experience and current practices with respect to exposure assessment processes and judgement amongst occupational hygienists

Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface

Proceedings of the Workshop on Change of Representation and Problem Reformulation

The proceedings of the third Workshop on Change of representation and Problem Reformulation is presented. In contrast to the first two workshops, this workshop was focused on analytic or knowledge-based approaches, as opposed to statistical or empirical approaches called 'constructive induction'. The organizing committee believes that there is a potential for combining analytic and inductive approaches at a future date. However, it became apparent at the previous two workshops that the communities pursuing these different approaches are currently interested in largely non-overlapping issues. The constructive induction community has been holding its own workshops, principally in conjunction with the machine learning conference. While this workshop is more focused on analytic approaches, the organizing committee has made an effort to include more application domains. We have greatly expanded from the origins in the machine learning community. Participants in this workshop come from the full spectrum of AI application domains including planning, qualitative physics, software engineering, knowledge representation, and machine learning

Symmetry as Bias: Rediscovering Special Relativity

This paper describes a rational reconstruction of Einstein's discovery of special relativity, validated through an implementation: the Erlanger program. Einstein's discovery of special relativity revolutionized both the content of physics and the research strategy used by theoretical physicists. This research strategy entails a mutual bootstrapping process between a hypothesis space for biases, defined through different postulated symmetries of the universe, and a hypothesis space for physical theories. The invariance principle mutually constrains these two spaces. The invariance principle enables detecting when an evolving physical theory becomes inconsistent with its bias, and also when the biases for theories describing different phenomena are inconsistent. Structural properties of the invariance principle facilitate generating a new bias when an inconsistency is detected. After a new bias is generated. this principle facilitates reformulating the old, inconsistent theory by treating the latter as a limiting approximation. The structural properties of the invariance principle can be suitably generalized to other types of biases to enable primal-dual learning

Voter Turnout in Democratizing Southeast Asia: A Comparative Analysis of Electoral Participation in Five Countries

We consider alternative explanations for variation in voter turnout rates across the five countries in Southeast Asia that the Polity IV database suggests are most “democratic.” Research on voter turnout in Western states has typically drawn connections between institutional, demographic, political, and economic variables and turnout levels. In this essay, we test each group of predictors and attempt to begin the process of isolating the factors that are most relevant to electoral participation in Southeast Asia. The research finds that many traditional explanations for voter turnout are inadequate. Yet, high quality formal democracy, combined with poor economic conditions, can reasonably predict voter turnout in the countries studied. In the end, the research qualifies our results in an attempt to prompt a more thorough discussion and understanding of democratization in the region

The expansion of thymopoiesis in neonatal mice is dependent on expression of high mobility group a 2 protein (Hmga2).

Cell number in the mouse thymus increases steadily during the first two weeks after birth. It then plateaus and begins to decline by seven weeks after birth. The factors governing these dramatic changes in cell production are not well understood. The data herein correlate levels of High mobility group A 2 protein (Hmga2) expression with these temporal changes in thymopoiesis. Hmga2 is expressed at high levels in murine fetal and neonatal early T cell progenitors (ETP), which are the most immature intrathymic precursors, and becomes almost undetectable in these progenitors after 5 weeks of age. Hmga2 expression is critical for the initial, exponential expansion of thymopoiesis, as Hmga2 deficient mice have a deficit of ETPs within days after birth, and total thymocyte number is repressed compared to wild type littermates. Finally, our data raise the possibility that similar events occur in humans, because Hmga2 expression is high in human fetal thymic progenitors and falls in these cells during early infancy

Fouling assemblages associated with estuarine artificial reefs in new South Wales, Australia

Estudos prévios que examinaram a dinâmica de sucessão em recifes artificiais foram focalizados nas comunidades de peixes, e sempre ignoraram o papel exercido pelos organismos incrustantes sobre a estruturação das comunidades associadas aos recifes artificiais. O presente estudo tem por objetivo registrar o desenvolvimento das assembléias epibióticas em três sistemas de recifes artificiais estuarinos com desenho específico (Reef Ball®) localizados em Macquarie Lake, Botany Bay e Bacia de St Georges em New South Wales, Australia. O recrutamento nos recifes artificiais foi relativamente rápido e a maioria dos táxons identificados durante o período dos dois anos de estudo já pode ser observada no primeiro ano. Os recifes de Macquarie Lake e da Bacia de St Georges foram caracterizados por baixa diversidade, sendo registrado o número máximo de seis táxons; em contraste, nos recifes de Botany Bay foram observados dezesseis taxa. Os resultados indicaram que não houve diferença significativa na porcentagem de cobertura dos grupos taxonômicos, tanto na Bacia de St Georges quanto em Macquarie Lake. Por sua vez, as porcentagens de cobertura das espécies nos recifes de Botany Bay mostraram diferenças significativas dentro do complexo recifal. A análise da estrutura das assembléias, quando se considera a idade do recife, indicou a ocorrência de padrões discretos entre os estuários, havendo em geral uma redução da porcentagem de cobertura das algas filamentosas formadoras de tufos (AFT) com o aumento da idade recifal. As diferenças nas condições ambientais e físicas (turbidez, fluxo de água, ação das ondas e proximidade do recife natural) existentes entre estuários e recifes artificiais, podem ter contribuído para as variações observadas nas assembléias incrustantes em Botany Bay.Previous studies examining the dynamics of succession on artificial reefs have predominantly focussed on fish communities and largely ignored the role of fouling assemblages in explaining the patterns of community structure associated with artificial reefs. The objective of this study was to record the development of epibiotic assemblages on three "design specific" (Reef Ball®) estuarine artificial reefs systems located in Lake Macquarie, Botany Bay and St Georges Basin in New South Wales, Australia. Recruitment to the artificial reefs was relatively rapid with the majority of taxa identified over the two-year study period observed within the first year post-deployment. The artificial reefs in Lake Macquarie and St Georges Basin were characterised by low diversity with four and nine taxa recorded respectively in contrast to the sixteen taxa observed on the Botany Bay reefs. Results indicated no significant differences in percentage cover of taxa among reefs in either St Georges Basin or Lake Macquarie. In contrast, comparisons between individual Botany Bay reefs identified significant differences in the percentage cover of species between artificial reefs. Analysis of assemblage structure with reef age indicated discrete patterns among estuaries with an overall reduction in the percentage cover of filamentous turfing algae (FTA) identified for all reef systems with an increase in reef age. Variations in environmental and physical conditions (turbidity, water flow, wave action and proximity to naturally occurring reef) may have contributed to the observed differences in fouling assemblages between estuaries and between artificial reefs within Botany Bay

Generation and Exploitation of Aggregation Abstractions for Scheduling and Resource Allocation

Our research is investigating abstraction of computational theories for scheduling and resource allocation. These theories are represented in a variant of first order predicate calculus, parameterized multisorted logic, that facilitates specification of large problems. A particular problem is conceptually stated as a set of ground sentences that are consistent with a quantified theory. We are mainly investigating the automated generation of aggregation abstractions and approximations in which detailed resource allocation constraints are replaced by constraints between aggregate demand and capacity. We are also investigating the interaction of aggregation abstractions with the more thoroughly investigated abstractions of weakening operator preconditions. The purpose of the theories for aggregated demand/capacity is threefold: first, to answer queries about aggregate properties, such as gross feasibility; second, to reduce computational costs by using the solution of aggregate problems to guide the solution of detailed problems; and third, to facilitate reformulating theories to approximate problems for which there are efficient problem solving methods. We also describe novel methods for exploiting aggregation abstractions