The concept of strong and weak virtual reality

We approach the virtual reality phenomenon by studying its relationship to set theory, and we investigate the case where this is done using the wellfoundedness property of sets. Our hypothesis is that non-wellfounded sets (hypersets) give rise to a different quality of virtual reality than do familiar wellfounded sets. We initially provide an alternative approach to virtual reality based on Sommerhoff's idea of first and second order self-awareness; both categories of self-awareness are considered as necessary conditions for consciousness in terms of higher cognitive functions. We then introduce a representation of first and second order self-awareness through sets, and assume that these sets, which we call events, originally form a collection of wellfounded sets. Strong virtual reality characterizes virtual reality environments which have the limited capacity to create only events associated with wellfounded sets. In contrast, the more general concept of weak virtual reality characterizes collections of virtual reality mediated events altogether forming an entirety larger than any collection of wellfounded sets. By giving reference to Aczel's hyperset theory we indicate that this definition is not empty, because hypersets encompass wellfounded sets already. Moreover, we argue that weak virtual reality could be realized in human history through continued progress in computer technology. Finally, we reformulate our characterization into a more general framework, and use Baltag's Structural Theory of Sets (STS) to show that within this general hyperset theory Sommerhoff's first and second order self-awareness as well as both concepts of virtual reality admit a consistent mathematical representation.Comment: 17 pages; several edits in v

When information does not suffice: young people living with HIV and communication about ART adherence in the clinic.

Despite mounting evidence recommending disclosure of human immunodeficiency virus (HIV) status to young people with perinatally acquired HIV as a central motivating factor for adherence to antiretroviral therapy, many young people continue to experience disclosure as a partial event, rather than a process. Drawing from two longitudinal, interview-based qualitative studies with young people living with HIV (aged 10-24) in five different countries in low and high income settings, we present data regarding disclosure and information about HIV in the clinic. The article highlights the limits of discussions framing disclosure and patient literacy, and young people's reluctance to voice their adherence difficulties in the context of their relationships with clinical care teams. We suggest that a clinician-initiated, explicit acknowledgment of the social and practical hurdles of daily adherence for young people would aid a more transparent conversation and encourage young people to disclose missed doses and other problems they may be facing with their treatment. This may help to reduce health harms and poor adherence in the longer-term

'This is what is going to help me': Developing a co-designed and theoretically informed harm reduction intervention for mobile youth in South Africa and Uganda

Young migrants in sub-Saharan Africa are particularly vulnerable to HIV-acquisition. Despite this, they are consistently under-served by services, with low uptake and engagement. We adopted a community-based participatory research approach to conduct longitudinal qualitative research among 78 young migrants in South Africa and Uganda. Using repeat in-depth interviews and participatory workshops we sought to identify their specific support needs, and to collaboratively design an intervention appropriate for delivery in their local contexts. Applying a protection-risk conceptual framework, we developed a harm reduction intervention which aims to foster protective factors, and thereby nurture resilience, for youth ‘on the move’ within high-risk settings. Specifically, by establishing peer supporter networks, offering a ‘drop-in’ resource centre, and by identifying local adult champions to enable a supportive local environment. Creating this supportive edifice, through an accessible and cohesive peer support network underpinned by effective training, supervision and remuneration, was considered pivotal to nurture solidarity and potentially resilience. This practical example offers insights into how researchers may facilitate the co-design of acceptable, sustainable interventions

Editorial: Understandings and conceptualizations of hope and how it influences engagement with sexual and reproductive health (SRH) services among adolescents in LMICs

This is the final version. Available on open access from Frontiers Media via the DOI in this rrecordAfrica Health Research InstituteWellcome TrustNational Institute for Health and Care Research (NIHR)UKR

Surfactants: their role in preventing the precipitation of proteins by tannins in insect guts

Much more tannic acid or pin oak tannin is required to precipitate the abundant leaf protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), from Manduca sexta gut fluid adjusted to pH 6.5 than is required to precipitate this protein from an aqueous buffer at the same pH. This finding demonstrates that some characteristic of M. sexta gut fluid, in addition to its basicity, counteracts the potential of tannins to precipitate ingested proteins. Gut fluid of M. sexta has a surface tension of 36–39 dynes/cm, indicating the presence of surfactants. Lysolecithin and linoleoylglycine, surfactants known to be present in insect gut fluids, also interfere with the precipitation of RuBPC by tannins at pH 6.5. It is concluded that detergency is a widespread property of insect gut fluids that counteracts the potential of tannins to precipitate die ary proteins, and it is argued that there is no longer any justification for continuing to refer to tannins as digestibility-reducing-substances. Finding that there has been no formidable barrier to the evolution of mechanisms that counter a generalized antidigestive action by tannins is difficult to reconcile with the idea that reduced digestibility is an evolved anti-herbivore adaptation of apparent plants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47751/1/442_2004_Article_BF00379632.pd

Detection of keyboard vibrations and effects on perceived piano quality

Two experiments were conducted on an upright and a grand piano, both either producing string vibrations or conversely being silent after the initial keypress, while pianists were listening to the feedback from a synthesizer through insulating headphones. In a quality experiment, participants unaware of the silent mode were asked to play freely and then rate the instrument according to a set of attributes and general preference. Participants preferred the vibrating over the silent setup, and preference ratings were associated to auditory attributes of richness and naturalness in the low and middle ranges. Another experiment on the same setup measured the detection of vibrations at the keyboard, while pianists played notes and chords of varying dynamics and duration. Sensitivity to string vibrations was highest in the lowest register and gradually decreased up to note D5. After the percussive transient, the tactile stimuli exhibited spectral peaks of acceleration whose perceptibility was demonstrated by tests conducted in active touch conditions. The two experiments confirm that piano performers perceive vibratory cues of strings mediated by spectral and spatial summations occurring in the Pacinian system in their fingertips, and suggest that such cues play a role in the evaluation of quality of the musical instrument

The Tri-Trophic Interactions Hypothesis: Interactive Effects of Host Plant Quality, Diet Breadth and Natural Enemies on Herbivores

Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI) hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists) should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality) host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia) quality and predators between a specialist (Uroleucon macolai) and a generalist (Aphis gossypii) aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores

Implementation of Medication Event Reminder Monitors among patients diagnosed with drug susceptible tuberculosis in rural Viet Nam: A qualitative study.

BACKGROUND: Despite the criticality of adherence to tuberculosis treatment, there is paucity of rigorous experimental research exploring the efficacy of interventions to promote adherence and a greater lack of inquiry addressing the integral role of adherence behaviour. The aim of this formative study was to examine the way in which the Wisepill evriMED Medication Event Reminder Monitor (MERM) was used among outpatients with drug susceptible pulmonary tuberculosis. METHODS: In depth interviews were conducted with 20 outpatients receiving treatment from two public healthcare facilities in Thanh Hoa, a rural province in northern Viet Nam. Patients had been enrolled in a randomized controlled trial evaluating the effect of using the MERM device upon adherence for between 1-3 months. The control group used the device without an alert, while the intervention group used the device with a daily alert and scheduled dosing history review. FINDINGS: All 20 patients interviewed were supportive of using the MERM device. Those able to be at home at the time that their treatment was due (50%) used the device as intended. Patients who worked all reported separating the time when the box was opened from the time at which they ingested their medication. Patients expressed fidelity to the prescribed medication taking time and concerns regarding the portability of the device. Limitations of the study surround the inclusion of a small sample population that did not experience factors that further compromise adherence. CONCLUSIONS: Data recorded by the box did not always accurately reflect usage patterns. The alert in the intervention arm was able to support adherence only in patients who did not work while completing their treatment. MERM implementation can be improved by better aligning prescriber instructions with patients' daily routines, and increasing the use of adherence data to guide adherence support practices. Healthcare staff need to be aware of potential barriers to optimal use of MERM devices. A rigorous qualitative approach to formative assessment is essential to inform the scale up of new digital technologies

Frequency of HIV-1 Viral Load Monitoring of Patients Initially Successfully Treated with Combination Antiretroviral Therapy

BACKGROUND: Although considered an essential tool for monitoring the effect of combination antiretroviral treatment (CART), HIV-1 RNA (viral load, VL) testing is greatly influenced by cost and availability of resources. ----- OBJECTIVES: To examine whether HIV infected patients who were initially successfully treated with CART have less frequent monitoring of VL over time and whether CART failure and other HIV-disease and sociodemographic characteristics are associated with less frequent VL testing. ----- METHODS: The study included patients who started CART in the period 1999-2004, were older than 18 years, CART naive, had two consecutive viral load measurements of <400 copies/ml after 5 months of treatment and had continuous CART during the first 15 months. The time between two consecutive visits (days) was the outcome and associated factors were assessed using linear mixed models. ----- RESULTS: We analyzed a total of 128 patients with 1683 visits through December 2009. CART failure was observed in 31 (24%) patients. When adjusted for the follow-up time, the mean interval between two consecutive VL tests taken in patients before CART failure (155.2 days) was almost identical to the interval taken in patients who did not fail CART (155.3 days). On multivariable analysis, we found that the adjusted estimated time between visits was 150.9 days before 2003 and 177.6 in 2008/2009. A longer time between visits was observed in seafarers compared to non-seafarers; the mean difference was 30.7 days (95% CI, 14.0 to 47.4; p<0.001); and in individuals who lived more than 160 kilometers from the HIV treatment center (mean difference, 16 days, p=0.010). ----- CONCLUSIONS: Less frequent monitoring of VL became common in recent years and was not associated with failure. We identified seafarers as a population with special needs for CART monitoring and delivery

Implementation of Medication Event Reminder Monitors among patients diagnosed with drug susceptible tuberculosis in rural Viet Nam: A qualitative study.

BACKGROUND: Despite the criticality of adherence to tuberculosis treatment, there is paucity of rigorous experimental research exploring the efficacy of interventions to promote adherence and a greater lack of inquiry addressing the integral role of adherence behaviour. The aim of this formative study was to examine the way in which the Wisepill evriMED Medication Event Reminder Monitor (MERM) was used among outpatients with drug susceptible pulmonary tuberculosis. METHODS: In depth interviews were conducted with 20 outpatients receiving treatment from two public healthcare facilities in Thanh Hoa, a rural province in northern Viet Nam. Patients had been enrolled in a randomized controlled trial evaluating the effect of using the MERM device upon adherence for between 1-3 months. The control group used the device without an alert, while the intervention group used the device with a daily alert and scheduled dosing history review. FINDINGS: All 20 patients interviewed were supportive of using the MERM device. Those able to be at home at the time that their treatment was due (50%) used the device as intended. Patients who worked all reported separating the time when the box was opened from the time at which they ingested their medication. Patients expressed fidelity to the prescribed medication taking time and concerns regarding the portability of the device. Limitations of the study surround the inclusion of a small sample population that did not experience factors that further compromise adherence. CONCLUSIONS: Data recorded by the box did not always accurately reflect usage patterns. The alert in the intervention arm was able to support adherence only in patients who did not work while completing their treatment. MERM implementation can be improved by better aligning prescriber instructions with patients' daily routines, and increasing the use of adherence data to guide adherence support practices. Healthcare staff need to be aware of potential barriers to optimal use of MERM devices. A rigorous qualitative approach to formative assessment is essential to inform the scale up of new digital technologies