Observational Research on NCDs in HIV-Positive Populations: Conceptual and Methodological Considerations

: Noncommunicable diseases (NCDs) account for a growing burden of morbidity and mortality among people living with HIV in low- and middle-income countries (LMICs). HIV infection and antiretroviral therapy interact with NCD risk factors in complex ways, and research into this "web of causation" has so far been largely based on data from high-income countries. However, improving the understanding, treatment, and prevention of NCDs in LMICs requires region-specific evidence. Priority research areas include: (1) defining the burden of NCDs among people living with HIV, (2) understanding the impact of modifiable risk factors, (3) evaluating effective and efficient care strategies at individual and health systems levels, and (4) evaluating cost-effective prevention strategies. Meeting these needs will require observational data, both to inform the design of randomized trials and to replace trials that would be unethical or infeasible. Focusing on Sub-Saharan Africa, we discuss data resources currently available to inform this effort and consider key limitations and methodological challenges. Existing data resources often lack population-based samples; HIV-negative, HIV-positive, and antiretroviral therapy-naive comparison groups; and measurements of key NCD risk factors and outcomes. Other challenges include loss to follow-up, competing risk of death, incomplete outcome ascertainment and measurement of factors affecting clinical decision making, and the need to control for (time-dependent) confounding. We review these challenges and discuss strategies for overcoming them through augmented data collection and appropriate analysis. We conclude with recommendations to improve the quality of data and analyses available to inform the response to HIV and NCD comorbidity in LMICs.

A Conceptual Model to Combine Creativity Techniques with Fuzzy Cognitive Maps for Enhanced Knowledge Management

This chapter introduces a conceptual model to combine creativity techniques with fuzzy cognitive maps (FCMs) and aims to support knowledge management methods by improving expert knowledge acquisition and aggregation. The aim of the conceptual model is to represent acquired knowledge in a manner that is as computer-understandable as possible with the intention of developing automated reasoning in the future as part of intelligent information systems. The formal represented knowledge thus may provide businesses with intelligent information integration. To this end, we introduce and evaluate various creativity techniques with a list of attributes to define the most suitable to combine with FCMs. This proposed combination enables enhanced knowledge management through the acquisition and representation of expert knowledge with FCMs. Our evaluation indicates that the creativity technique known as mind mapping is the most suitable technique in our set. Finally, a scenario from stakeholder management demonstrates the combination of mind mapping with FCMs as an integrated system.

Shared Rule in Federal Political Systems: Conceptual Lessons from Subnational Switzerland

This article reconceptualizes shared rule and uses novel data to measure it, thus addressing two shortcomings of federal literature. First, while most studies focus on self-rule, one question that is largely neglected is how lower-level governments can influence politics at a higher level in the absence of “second” chambers. The answer is through shared rule. A second shortcoming is that even when addressing this question, scholars concentrate on constitutional-administrative aspects of vertical intergovernmentalism, neglecting more informal, “political” dynamics. Comparing the twenty-six Swiss cantons allows drawing two lessons for federal studies: That shared rule is multifaceted and complex, and that to study informal territorial actors as well as direct political processes is indispensable to understand how power is actually distributed in federal political systems.

Career adaptivity, adaptability, and adapting: A conceptual and empirical investigation

The literature on career adaptation is vast and based on a range of different measurement approaches. The present paper aims to explore how different operationalizations of career adaptability in terms of concern, control, curiosity, and confidence are related from a conceptual and empirical standpoint. Based on a cross-sectional analysis with 1260 German university students, we established that the adaptability resources of concern, control, curiosity, and confidence are significantly related to, but empirically distinct from, measures representing adapting in terms of career planning, career decision-making difficulties, career exploration, and occupational self-efficacy. In a follow-up survey six months later, we found that the career adaptability dimensions partially mediated the effects of adaptivity (i.e., core self-evaluations and proactivity) on planning, decision-making difficulties, exploration, and self-efficacy. Interestingly, in both analyses, there was no clear match between adaptability resources and theoretically corresponding aspects of career adapting in terms of behaviors, beliefs, and barriers. The results suggest that psychological career resources in terms of concern, control, curiosity, and confidence partially mediate the effects of more context-general, trait-like adaptivity on different career-specific behavioral forms of adapting.

A conceptual model of compensation/decompensation in lumbar segmental instability

Lumbar spinal instability (LSI) is a common spinal disorder and can be associated with substantial disability. The concept of defining clinically relevant classifications of disease or 'target condition' is used in diagnostic research. Applying this concept to LSI we hypothesize that a set of clinical and radiological criteria can be developed to identify patients with this target condition who are at high risk of 'irreversible' decompensated LSI for whom surgery becomes the treatment of choice. In LSI, structural deterioration of the lumbar disc initiates a degenerative cascade of segmental instability. Over time, radiographic signs become visible: traction spurs, facet joint degeneration, misalignment, stenosis, olisthesis and de novo scoliosis. Ligaments, joint capsules, local and distant musculature are the functional elements of the lumbar motion segment. Influenced by non-functional factors, these functional elements allow a compensation of degeneration of the motion segment. Compensation may happen on each step of the degenerative cascade but cannot reverse it. However, compensation of LSI may lead to an alleviation or resolution of clinical symptoms. In return, the target condition of decompensation of LSI may cause the new occurrence of symptoms and pain. Functional compensation and decompensation are subject to numerous factors that can change which makes estimation of an individual's long-term prognosis difficult. Compensation and decompensation may influence radiographic signs of degeneration, e.g. the degree of misalignment and segmental angulation caused by LSI is influenced by the tonus of the local musculature. This conceptual model of compensation/decompensation may help solve the debate on functional and psychosocial factors that influence low back pain and to establish a new definition of non-specific low back pain. Individual differences of identical structural disorders could be explained by compensated or decompensated LSI leading to changes in clinical symptoms and pain. Future spine surgery will have to carefully define and measure functional aspects of LSI, e.g. to identify a point of no return where multidisciplinary interventions do not allow a re-compensation and surgery becomes the treatment of choice.

Conceptual design and simulation of a water Cherenkov muon veto for the XENON1T experiment

XENON is a dark matter direct detection project, consisting of a time projection chamber (TPC) filled with liquid xenon as detection medium. The construction of the next generation detector, XENON1T, is presently taking place at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It aims at a sensitivity to spin-independent cross sections of 2 10-47 c 2 for WIMP masses around 50 GeV2, which requires a background reduction by two orders of magnitude compared to XENON100, the current generation detector. An active system that is able to tag muons and muon-induced backgrounds is critical for this goal. A water Cherenkov detector of ~ 10 m height and diameter has been therefore developed, equipped with 8 inch photomultipliers and cladded by a reflective foil. We present the design and optimization study for this detector, which has been carried out with a series of Monte Carlo simulations. The muon veto will reach very high detection efficiencies for muons (>99.5%) and showers of secondary particles from muon interactions in the rock (>70%). Similar efficiencies will be obtained for XENONnT, the upgrade of XENON1T, which will later improve the WIMP sensitivity by another order of magnitude. With the Cherenkov water shield studied here, the background from muon-induced neutrons in XENON1T is negligible.