Karthika Poornachandran, Elakkiya Venkatachalam, Oh-Min Kwon
et al.
In this work, we develop a disturbance suppression-oriented fuzzy sliding mode secured sampled-data controller for third-order parabolic partial differential equations that ought to cope with nonlinearities, hybrid cyber attacks, and modeled disturbances. This endeavor is mainly driven by formulating an observer model with a T–S fuzzy mode of execution that retrieves the latent state variables of the perceived system. Progressing onward, the disturbance observers are formulated to estimate the modeled disturbances emerging from the exogenous systems. In due course, the information received from the system and disturbance estimators, coupled with the sliding surface, is compiled to fabricate the developed controller. Furthermore, in the realm of security, hybrid cyber attacks are scrutinized through the use of stochastic variables that abide by the Bernoulli distributed white sequence, which combat their unpredictability. Proceeding further in this framework, a set of linear matrix inequality conditions is established that relies on the Lyapunov stability theory. Precisely, the refined looped Lyapunov–Krasovskii functional paradigm, which reflects in the sampling period that is intricately split into non-uniform intervals by leveraging a fractional-order parameter, is deployed. In line with this pursuit, a strictly <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><msub><mo>Φ</mo><mn>1</mn></msub><mo>,</mo><msub><mo>Φ</mo><mn>2</mn></msub><mo>,</mo><msub><mo>Φ</mo><mn>3</mn></msub><mo>)</mo><mo>−</mo><mi>ϱ</mi></mrow></semantics></math></inline-formula> dissipative framework is crafted with the intent to curb norm-bounded disturbances. A simulation-backed numerical example is unveiled in the closing segment to underscore the potency and efficacy of the developed control design technique.
Hiske Joanna Brouwer, Elco Buurma, Esther de Groot
et al.
Introduction: Clinician-teachers are engaged in both clinical practice and education. They positively influence student learning by connecting clinical practice and education. Most research into clinician-teacher’s dual role was performed in the clinical settings where practice and teaching are intertwined. The benefits of clinician-teachers’ dual role in the classroom-setting have been underexplored, whilst a large part of medical education is classroom-based. Using boundary work theory as a lens, this study aimed to illuminate clinician-teachers’ observable boundary spanning behavior integrating the clinical practice and medical education in the classroom. Methods: A qualitative observation study of classroom-teaching within postgraduate general practitioner specialty training at three Dutch medical institutes was conducted. Video recordings and transcripts of classroom teaching were analyzed using a structured observation schedule. Boundary spanning behavior was categorized into: boundary bridging, boundary making and boundary maintenance. Distinctions were made between verbal- and non-verbal behavior. Results: All three categories of boundary spanning behavior were observed. Clinician-teachers demonstrated boundary bridging by integrating their own clinical experiences, by normalizing students’ reported clinical experiences, by encouraging students’ sharing of clinical experiences and by encouraging students to apply theory in practice. Clinician-teachers demonstrated boundary making by accentuating discontinuities between clinical practice and educational information, and boundary maintenance by allowing transient differences to exist between the two settings for didactic reasons. Discussion: This observational study contributes to an understanding of how clinician-teachers use their experience as a clinician in classroom-teaching. These insights may contribute to faculty development fostering boundary-spanning teaching practices.
Background Antiretroviral therapy has transformed human immunodeficiency virus infection intoa chronic condition associated with normal life expectancy. In the United Kingdom, the uptake of antiretroviral therapy is generally high, but a delay in starting antiretroviral therapy and non-adherence compromise the health and well-being of people living with human immunodeficiency virus, increase the risk of transmission of human immunodeficiency virus and increase National Health Service costs. Objectives The overall aim was to improve antiretroviral therapy uptake and adherence by addressing perceptual and practical barriers. The objectives were to (1) identify culturally specific beliefs and other factors influencing uptake of and adherence to antiretroviral therapy that have not emerged in previous research; (2) refine existing methods for assessing perceptual and practical barriers to antiretroviral therapy uptake and adherence; (3) develop an intervention to increase antiretroviral therapy uptakeand adherence; (4) determine intervention feasibility and acceptability; (5) evaluate intervention efficacy;(6) assess the short- and long-term costs and cost-effectiveness of the interventions and (7) prepare for implementation within the National Health Service. Design Objective 1 – in-depth interviews with Black African and Black Caribbean people living with human immunodeficiency virus (n = 52); objective 2 – adaptation of the Beliefs about Medicines Questionnaire; objective 3 – development of the Supporting UPtake and Adherence to antiretroviral therapy service intervention; objective 4 – feasibility study (n = 213) and acceptability/process interviews (n = 24); objective 5 – observational study (n = 484) and randomised controlled trial (n = 143); objective 6 – systematic review, cost-effectiveness analysis (n = 210) and economic modelling; and objective 7 – preparatory implementation work with people living with human immunodeficiency virus and human immunodeficiency virus clinic staff. Setting National Health Service human immunodeficiency virus clinics in England with a high proportion of ethnic minority populations. Participants People living with human immunodeficiency virus. Interventions Adherence support – cognitive–behavioural therapy plus care as usual. Main outcome measures Workstream 1 – adapted Beliefs about Medicines Questionnaire–antiretroviral therapy. Workstream 2 – feasibility study: participant recruitment and withdrawal rates. Workstream 3 – randomised controlled trial – primary outcome: medication event monitoring system adherence. Workstream 4 – incremental cost-effectiveness ratio. Results Workstream 1 – qualitative studies were used to refine the Beliefs about Medicines Questionnaire – antiretroviral therapy and, together with our preparatory research, to inform the cognitive–behavioural therapy-based intervention. Workstream 2 – recruitment to the randomised controlled trial and observational study was deemed feasible. Thematic analysis of exit interviews with recipients of the SUPA intervention demonstrated that the intervention was acceptable and addressed perceptual and practical barriers to antiretroviral therapy. In Workstream 3, we did not meet the recruitment targets and our trial was underpowered for the primary outcome: 143 participants met the inclusion criteria and were randomised (care as usual, n = 72; care as usual plus cognitive–behavioural therapy, n = 71). There was no significant effect of cognitive–behavioural therapy on the primary end point. Of the 112 participants (care as usual, n = 55; cognitive–behavioural therapy, n = 57) for whom sufficient data for primary end-point analysis were available, 17 (15.2%) met the primary end point (> 80% of months with an average monthly adherence of ≥ 90%) [9 (16.4%) in the care-as-usual group and 8 (14.0%) in the cognitive–behavioural therapy group (p = 0.94)]. Secondary end points: median Medication Event Monitoring System adherence at 12 months was 61.9% in the care-as-usual group and 66.5% in the cognitive–behavioural therapy group (p = 0.40), representing a 7.5% uplift in adherence. Participants who were randomised to receive the intervention, based on perceptions of antiretroviral therapy at baseline (low antiretroviral therapy necessity beliefs, and/or high antiretroviral therapy concerns), experienced a greater decrease in antiretroviral therapy concerns [care as usual −0.9 (95% confidence interval −1.4 to −0.5) vs. cognitive–behavioural therapy −0.6 (95% confidence interval −0.8 to −0.3); p = 0.03], treatment intrusiveness [median change in highly active antiretroviral treatment (antiretroviral therapy) Intrusiveness Scale scores: care as usual −0.5 (95% confidence interval −5.6 to 18.0) vs. cognitive–behavioural therapy −5.6 (95% confidence interval −20.4 to 1.2); p = 0.03] and depression scores [median change in depression score: care as usual 0 (95% confidence interval −1.5 to 2.0) vs. cognitive–behavioural therapy −1 (95% confidence interval −3 to 0); p = 0.02] between baseline and 12 months. Workstream 4 – cognitive–behavioural therapy resulted in 0.056 more quality-adjusted life-years than care as usual (95% confidence interval 0.0029 to 0.083). The incremental cost-effectiveness ratio was £11,189 per quality-adjusted life-year. At a threshold of £20,000 per quality-adjusted life-year, there was > 90% likelihood that the intervention would be more cost-effective than care as usual. There was a 13% likelihood that the intervention would produce more quality-adjusted life-years and result in lower health and social care costs than care as usual. A Markov model showed that, over the longer term, cognitive–behavioural therapy results in fewer quality-adjusted life-years and higher costs and, therefore, care as usual would be the more cost-effective option. Limitations Our primary outcome of full Medication Event Monitoring System adherence was problematic, our randomised controlled trial was underpowered and we were unable to demonstrate a significant difference in our primary outcome. Conclusions Patients who received the Supporting UPtake and Adherence to antiretroviral therapy service intervention benefited from a reduction in antiretroviral therapy concerns, a reduction in antiretroviral therapy intrusiveness and reduced depressive symptoms, and from improved quality of life. The intervention was likely to be cost-effective for the National Health Service within 12 months. Future work Given the difficulty in recruiting people at a high risk of non-engagement with human immunodeficiency virus care, future work assessing the effectiveness of adherence interventions may require alternative, non-standard randomised controlled trial designs. Further studies are necessary to recalibrate our understanding of the levels of antiretroviral therapy adherence necessary to achieve viral load suppression. Study registration The trial is registered as ISRCTN35514212 and the study is registered as CRD42019072431. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research Programme (NIHR award ref: RP-PG-0109-10047) and is published in full in Programme Grants for Applied Research; Vol. 13, No. 8. See the NIHR Funding and Awards website for further award information.
Plain language summary Human immunodeficiency virus treatment (known as antiretroviral therapy) is very effective, but some patients do not get the full benefit because they delay treatment or miss doses. This increases the chances of getting ill and the risk of passing human immunodeficiency virus on to others. There are many reasons why people delay treatment or take less than has been prescribed, including beliefs and concerns about treatment and practical difficulties. People from United Kingdom Black African and Caribbean communities often experience difficulties with human immunodeficiency virus treatment, but few studies have focused on this group. We interviewed 52 people from Black African and Caribbean communities about their views and experiences of human immunodeficiency virus and its treatment, and designed questionnaires to measure these. After consulting with people living with human immunodeficiency virus, we developed a new service to help people get the best from human immunodeficiency virus treatment (i.e. Supporting UPtake and Adherence to antiretroviral therapy). The Supporting UPtake and Adherence to antiretroviral therapy service included a video and booklet about human immunodeficiency virus and antiretroviral therapy and up to four meetings or telephone calls with a nurse to address questions and concerns. We compared the Supporting UPtake and Adherence to antiretroviral therapy service with usual National Health Service care to test whether or not patients who received the Supporting UPtake and Adherence to antiretroviral therapy intervention were more likely to take antiretroviral therapy as prescribed by their doctor (known as adherence). We also tested whether or not the Supporting UPtake and Adherence to antiretroviral therapy programme benefited patients by reducing antiretroviral therapy concerns and practical difficulties, and if it improved depression and provided value for money for the National Health Service. It was more difficult than we expected to recruit people to the trial. Because of this, and difficulties in measuring the amount of antiretroviral therapy taken, we did not show that people who received the Supporting UPtake and Adherence to antiretroviral therapy intervention took more antiretroviral therapy over 12 months than those who received normal care. People who received the Supporting UPtake and Adherence to antiretroviral therapy intervention benefited from reduced concerns about antiretroviral therapy and antiretroviral therapy interfered less in their lives. People who received the Supporting UPtake and Adherence to antiretroviral therapy intervention were also less depressed and used fewer extra National Health Service services. The Supporting UPtake and Adherence to antiretroviral therapy service represented value for money in the short term.
Scientific summary Background Antiretroviral therapy (ART) is highly effective and the majority of people living with human immunodeficiency virus (PLWH) in the UK now have an undetectable viral load and a near-normal life expectancy and pose a low risk of onward human immunodeficiency virus (HIV) transmission. However, adherence to ART is necessary to suppress and maintain an undetectable HIV viral load. Substantial numbers of PLWH in the UK are not prescribed ART or have a detectable viral load when prescribed ART. This is a problem because both delays to start ART and non-adherence compromise the health and well-being of PLWH, increase the risk of HIV transmission and increase NHS costs. There is a need for a pragmatic, evidence-based approach to increase uptake and adherence to ART. Interventions to increase adherence across long-term conditions have had limited success, and it is not yet clear which strategies are most effective. To optimise engagement with ART, there is a need to understand why people with HIV may not want to, or be unable to, initiate and take ART. Our preparatory research was conducted across multiple chronic illnesses, including HIV infection, and in different cultural contexts and showed that adherence was consistently related to both perceptions of their treatment [i.e. how patients judged their personal necessity for treatment (necessity beliefs) relative to their concerns about potential adverse effects] and practical difficulties with taking treatment, such as limitations in capability and opportunity. This work influenced the National Institute for Health and Care Excellence (NICE) guidelines for adherence that recommend tailoring adherence support to address the specific perceptual and practical barriers that are salient for the individual. Aim The aim of this programme was to improve engagement with ART (uptake and adherence) by addressing perceptual and practical barriers, providing the evidence base for HIV care and informing the implementation of NHS policy. Figure a shows an overview of the programme and highlights the various components of each workstream (WS). FIGURE aProgramme overview. AC, ancillary study; BMQ, Beliefs about Medicines Questionnaire; CAU, care as usual; CBT, cognitive–behavioural therapy; IPA, interpretative phenomenological analysis; RCT, randomised controlled trial; SUPA, Supporting UPtake and Adherence to ART. Objectives Identify culturally specific beliefs and other factors influencing uptake of and adherence to ART that have not emerged in previous research. Refine our existing methods for eliciting and measuring the salient perceptual and practical factors influencing uptake of and adherence to ART. Develop an intervention (including intervention manuals, materials and therapeutic intervention) to increase uptake of and adherence to ART. Determine the feasibility and acceptability of the intervention. Evaluate the efficacy of the intervention for increasing ART uptake and adherence. Assess the costs and cost-effectiveness of providing the intervention in the short and long term. Prepare for implementation within the NHS. Methods and results Workstream 1: intervention development Workstream 1 addressed objectives 1–3 in three studies from discussions with our patient and public involvement group, clinical advisors and our analysis of gaps in the published literature on adherence to antiretrovirals, it became apparent that people from UK Black African and Caribbean communities often experience difficulties with HIV treatment, but few studies have focused on this group. We therefore paid particular attention to this group in our intervention development studies. Study 1 identified culturally specific beliefs and other factors influencing the uptake of and adherence to ART in Black African and Caribbean communities that have not emerged in previous research. We interviewed 52 men and women from Black African and Caribbean communities in London who had been identified as having previous or current problems adhering to their medication. Two separate analyses were conducted. The first used interpretative phenomenological analysis to understand the lived experiences of taking ART among a group of women from West Africa (n = 10), which was a previously under-represented community in HIV adherence research. The analysis identified issues and challenges that the women experienced with adherence to ART. The following three overarching themes were identified: (1) negative experiences of medication, (2) temporal improvement and (3) spurs to adherence. The second analysis used framework analysis to identify perceptual and practical barriers to adherence (n = 52). This analysis of in-depth interviews with people with demonstrated suboptimal adherence showed that perceptual barriers to ART could be grouped into two overarching themes: doubts about the need for ART and concerns about potential harm and stigma. The findings of our preparative research were discussed with patient representatives and practising clinicians from centres with a large proportion of men who have sex with men (MSM). The consistent view was that our preparative research findings remained relevant for MSM and that further research in this group to inform our measures of perceptual and practical barriers to ART was unnecessary. Study 2 refined existing methods to measure patients’ perceptions of ART. The study 1 findings were used to refine our measures of perceptual and practical barriers to ART uptake and adherence with four items added to the Beliefs about Medicines Questionnaire (BMQ)-ART. Study 3 developed an intervention to address barriers and facilitate ART uptake and adherence. Medical Research Council guidance was applied to develop a cognitive–behavioural therapy (CBT)-based intervention to support uptake and adherence to ART. The intervention, intervention manual and animations were developed by an Intervention Development Group, including experts in adherence, behaviour change theory, CBT, HIV medicine, nursing, pharmacy and HIV patient advocacy. It was informed by our preparatory research and the findings of study 1, incorporating: standardised information about HIV and its treatment, designed to address common, adherence-related misconceptions and concerns and signpost patients to further support to help overcome practical difficulties with taking ART and reduce the degree to which ART interfered with daily living (ART intrusiveness), delivered through an animated video and a booklet personalised discussion with a HIV nurse to introduce the Supporting UPtake and Adherence to ART (SUPA) video and booklet and address barriers to adherence, applying CBT techniques in up to four sessions – the first was face to face, with further sessions in clinic or by telephone follow-up, determined by patient preference. The intervention manual and animation were reviewed by the SUPA management group and members of the target population. User testing and further development of materials were conducted with PLWH, who were recruited through the Africa Advocacy Foundation (AAF). Workstream 2: feasibility and acceptability of the Supporting UPtake and Adherence to antiretroviral therapy (cognitive–behavioural therapy) intervention Study 4 determined the feasibility and acceptability of the SUPA (CBT) intervention. Study 4 included the following two components. Quantitative feasibility study nested within the randomised controlled trial to determine the feasibility of the Supporting UPtake and Adherence to antiretroviral therapy intervention Over an initial period of 14 months, 213 PLWH were recruited to an observational study, of whom 86 were eligible for the randomised controlled trial (RCT) and 46 were successfully randomised [23 to the care as usual (CAU) group and 23 to the CBT group]. Rates of attrition were low: of the 213 patients enrolled in the observational study, only 5 were not reached for follow-up appointments. Of the 46 patients randomised, 2 withdrew. Qualitative feasibility study The qualitative feasibility study was a thematic analysis of qualitative interviews conducted with people randomised to receive the SUPA intervention. This analysis determined the acceptability of the SUPA intervention and explored the process of change. Twenty-four people from the PLWH community in the UK were interviewed about their experiences of taking part in the trial and receiving the SUPA intervention. Participants reported various reasons for enrolling in the trial, including the desire to learn about HIV and its treatment, play an active role in their health care, and give something back to other PLWH. Intervention sessions gave participants the opportunity to discuss their concerns about ART and to receive confidential advice and support. Participants indicated that the intervention materials were relevant and accessible. The findings indicated that the intervention addressed misconceptions about HIV, provided a rationale for taking ART, reduced concerns about ART and provided practical strategies for adherence and emotional support. Workstream 3: randomised controlled trial efficacy of the Supporting UPtake and Adherence to antiretroviral therapy cognitive–behavioural therapy-based intervention to support antiretroviral therapy uptake and adherence The efficacy of the SUPA intervention was examined in a RCT. A two-step consent process was followed. ART-naive PLWH who had received a treatment offer were recruited from eight HIV clinics in England to take part in an observational study. Participants completed the BMQ-ART, and those who had perceptual barriers to ART (doubts about personal need for ART and/or concerns about ART), and were therefore deemed at risk of non-adherence, were invited to take part in the RCT. Those who consented to take part in the RCT were randomised to receive CAU or CBT (Figure b). Those who were not eligible for the RCT or who declined to take part remained in the observational study and completed the BMQ-ART at the 3-, 6- and 12-month follow-ups. FIGURE bThe SUPA study trial design. The primary end point was designed to capture both a delay to initiate treatment and non-adherence, and was developed in discussion with NIHR. In the months prior to ART initiation, adherence was set to 0%. After starting ART, the proportion of days within the month with full adherence was assessed using Medication Event Monitoring System (MEMS®) (AARDEX Group, Seraing, Belgium). Adherence within each patient-month was then classified as being good (≥ 90%) or poor (< 90%), and the prespecified primary outcome was met if individuals achieved good adherence in > 80% of the months during which they were under follow-up. The secondary outcomes were percentage MEMS adherence, self-reported adherence, changes in beliefs about ART, ART intrusiveness and practical difficulties with ART, perceptions of HIV, depression and anxiety, viral load suppression, regimen switches, treatment failure, and disengagement from care. Between March 2014 and July 2017, 1575 patients were assessed for eligibility, of whom 143 were randomised (CAU, n = 72; CBT, n = 71). Recruitment was challenging, and our target of 372 was not reached. The observational study included 484 individuals who were not eligible or chose not to take part in the RCT (RCT-eligible decliners at high non-adherence risk, n = 27; not eligible for RCT at low non-adherence risk, n = 457). Owing to the challenges in using MEMS, the number of participants with sufficient data for primary end-point analysis was 112 (CAU, n = 55; CBT, n = 57). Of those, 17 participants (15.2%) met the primary end point (> 80% of months, with an average monthly adherence of ≥ 90%) [9 (16.4%) in the CAU group and 8 (14.0%) in the CBT group (p = 0.94)]. There was no significant difference in the primary outcome (i.e. MEMS adherence) between the CBT and CAU groups at 12 months. There was a 7% improvement in median percentage adherence by MEMS in the CBT group relative to the CAU group (61.9% CAU and 66.5% CBT; p = 0.40). There was a significant increase in the proportion of people with high adherence (by self-reported Medication Adherence Report Scale) at 3 months’ follow-up (75% CAU and 81% CBT; p = 0.02). Participants randomised to receive CAU plus CBT benefited from a significantly greater reduction in ART concerns, ART intrusiveness and depression between baseline and 12 months than those randomised to receive CAU. There were no significant differences between the randomised groups in ART necessity beliefs (which were high in both groups), anxiety, illness perceptions, viral load, cluster of differentiation 4 (CD4) T-cell count, rates of treatment failure or treatment switches. Workstream 4: economic studies Workstream 4, study 6, addressed objective 6: assessing the costs and cost-effectiveness of the SUPA intervention in the short and long term. It comprised three substudies, as follows. Systematic review of economic evaluations of antiretroviral therapy adherence interventions A systematic literature search identified 20 studies reporting costs or cost-effectiveness of interventions to increase adherence to ART in PLWH. The quality of the economic evaluations was assessed. There was evidence of improved adherence and favourable cost-effectiveness ratios in people receiving adherence interventions compared with the control conditions. However, these effects tended to be short term. Trial-based cost-effectiveness analysis of the Supporting UPtake and Adherence to antiretroviral therapy intervention Use of the intervention and other health and social care services and HIV-specific medications were measured in the RCT (i.e. study 5) and costs were calculated. Quality-adjusted life-years (QALYs) were generated from the EuroQol-5 Dimensions, five-level version (EQ-5D-5L). Costs were compared at baseline and each follow-up time point. QALYs were compared, controlling for baseline EQ-5D-5L tariffs. Cost-effectiveness was assessed by combining incremental costs and incremental QALYs using an incremental cost-effectiveness ratio (ICER). The mean costs among the CBT group were £621 more than for the CAU group. This difference was not statistically significant [95% confidence interval (CI) –£569 to £1462]. CBT resulted in 0.056 more QALYs over the follow-up period than CAU, and this was significant (95% CI 0.0029 to 0.083). The ICER was £9143 per QALY. At a threshold of £20,000 per QALY, there was more than a 90% likelihood that CBT would be more cost-effective than CAU. There was a 19% likelihood that CBT would produce more QALYs and result in lower health and social care costs than CAU. A simulation model of the long-term cost-effectiveness of the intervention A Markov model was used to extrapolate for 15 years, in 12-month cycles beyond the trial period. Health states were defined by CD4 T-cell counts and all-cause mortality. The expected costs for those receiving CBT and CAU in the 15 years after the trial follow-up were less for CBT than for CAU, but CBT also resulted in fewer QALYs. Combining the trial period with the 15-year extrapolation period resulted in CBT having costs that were lower by £470 and 0.47 fewer QALYs. Therefore, in the long term, CAU is cost-effective with an ICER of £1187 per QALY. Workstream 5: preparing for implementation within the National Health Service Workstream 5 was intended to address objective 7: prepare for implementation within the NHS. Owing to the extended time needed for recruitment to the RCT, we were unable to carry out a full implementation WS. We have planned implementation strategies informed by NICE guidance on how to change practice. These involve identifying barriers to implementation by conducting study discussion groups in HIV clinics, discussion of our findings with HIV commissioners and conducting focus groups with PLWH at AAF. Workstream 6 (additional workstream): ancillary studies During the programme, we conceived an additional seven ancillary studies (WS6): patients’ perceptions of standard care ART perceptions and treatment outcomes in HIV-positive patients starting ART to protect their partners (treatment as prevention) compared with clinical need the level ART adherence required to achieve virological suppression in treatment-naive patients a systematic review and meta-analysis examining the content of effective adherence interventions beliefs about ART as predictors of side effects (analysis of historical data) associations between self-reported adherence and electronic monitoring of adherence the effect of the SUPA intervention on rates of engagement with HIV services. These ancillary studies were conceived on the assumption of complete and timely recruitment to the SUPA RCT; however, recruitment was lower and slower than expected for this hard-to-reach study population. Consequently, only six ancillary studies were feasible (1–6). Conclusions The SUPA programme fulfilled its objectives to develop and evaluate a pragmatic, theory-based intervention to support ART uptake and adherence among PLWH at risk of non-adherence by addressing perceptual and practical barriers. Recruitment to the SUPA RCT was slower than anticipated and our trial was underpowered with no effect on the primary outcome measure of adherence over 12 months. However, the SUPA intervention benefited recipients by reducing ART concerns, ART intrusiveness and depression and improving quality of life. It was also cost-effective during the follow-up period. Study registration The trial is registered as ISRCTN35514212 and the study is registered as CRD42019072431. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research Programme (NIHR award ref: RP-PG-0109-10047) and is published in full in Programme Grants for Applied Research; Vol. 13, No. 8. See the NIHR Funding and Awards website for further award information.
Giulio Ruffini, Francesca Castaldo, Jakub Vohryzek
In the Kolmogorov Theory of Consciousness, algorithmic agents utilize inferred compressive models to track coarse-grained data produced by simplified world models, capturing regularities that structure subjective experience and guide action planning. Here, we study the dynamical aspects of this framework by examining how the requirement of tracking natural data drives the structural and dynamical properties of the agent. We first formalize the notion of a <i>generative model</i> using the language of symmetry from group theory, specifically employing Lie pseudogroups to describe the continuous transformations that characterize invariance in natural data. Then, adopting a generic neural network as a proxy for the agent dynamical system and drawing parallels to Noether’s theorem in physics, we demonstrate that data tracking forces the agent to mirror the symmetry properties of the generative world model. This dual constraint on the agent’s constitutive parameters and dynamical repertoire enforces a hierarchical organization consistent with the manifold hypothesis in the neural network. Our findings bridge perspectives from algorithmic information theory (Kolmogorov complexity, compressive modeling), symmetry (group theory), and dynamics (conservation laws, reduced manifolds), offering insights into the neural correlates of agenthood and structured experience in natural systems, as well as the design of artificial intelligence and computational models of the brain.
This research presents an innovative 330-ml beverage packaging solution that merges accessibility, design, and ergonomics for user comfort. The design incorporates shape principles, clear typography, and minimalist colours and symbols, balancing visual appeal and functionality. As demand for attractive options grows, this study investigates consumer preferences through surveys and interviews. It identifies key factors influencing choices, enhancing the design through quality function deployment (QFD) and product design development (PDD) methodologies. This approach integrates shape design, typography, and colour theory to meet aesthetic and functional needs. The packaging features ‘a bear-paw-shaped watermark’ for stability and ergonomic design for comfortable handling. A minimalist label, with fruit-inspired illustrations, modern fonts, and finishes like matte or glossy, enhances visual appeal. The ‘Trendy-Bottle Design Platform’ aids creation with templates, 3D visualisation, and collaboration tools. Key elements like brand details, nutritional facts, allergen information, a recycle sign, and sustainability symbols ensure functionality and alignment with consumer needs. From a customer perspective, trendy bottles should offer ergonomic designs, spill-proof functionality, eco-friendly materials, and affordability. Manufacturing considerations include optimising shelf space, with rectangular bottles saving space despite higher costs, and rounded bottles saving material but increasing shelf costs. Collaboration ensures moulds meet aesthetic and functional needs, improving appeal.
Elena Rovenskaya, Alexey Ivanov, Sarah Hathiari
et al.
Abstract Economic and social interactions are shifting to digital platforms which grow into vast ecosystems where user engagement creates value for members while ecosystem orchestrators harvest massive revenue. The digital ecosystem business model succeeds by adeptly navigating fast-changing environments, including new technologies and volatile demands, through dynamic innovation in a decentralized decision-making setting. This renders digital platform ecosystems complex adaptive systems. Recognizing that natural ecosystems are a prime example of complex adaptive systems, we propose a systematic hierarchical framework for describing and understanding digital ecosystems, rooted in ecology and evolution. Our framework compares digital ecosystems hosted by societies to natural ecosystems embedded in biomes, products to species, and technologies and elements of business strategy to the genetic makeup of a species. As digital platforms face heightened scrutiny about their socio-economic power and societal value, our approach contributes to the development of deeper understanding and sustainable governance of the digital economy.
Information theory, Electronic computers. Computer science
Characterization of entropy functions is of fundamental importance in information theory. By imposing constraints on their Shannon outer bound, i.e., the polymatroidal region, one obtains the faces of the region and entropy functions on them with special structures. In this series of two papers, we characterize entropy functions on the $2$-dimensional faces of the polymatroidal region $Γ_4$. In Part I, we formulated the problem, enumerated all $59$ types of $2$-dimensional faces of $Γ_4$ by a algorithm, and fully characterized entropy functions on $49$ types of them. In this paper, i.e., Part II, we will characterize entropy functions on the remaining $10$ types of faces, among which $8$ types are fully characterized and $2$ types are partially characterized. To characterize these types of faces, we introduce some new combinatorial design structures which are interesting in themselves.
Fransisca Dwi Harjanti, Lusy Tunik M, Roely Ardiansyah
This critical discourse study examines how language is used to marginalize certain groups in news titles published on social media. It focuses on linguistic elements, including words or terms, phrases, and sentences. As qualitative research employing discourse analysis methods, this study analyzes data from news headlines on social media or online media. Social media was chosen due to its widespread popularity as a source of information. Data analysis follows Fairclough’s theory, which includes text description, interpretation, and explanation. The findings reveal that news headlines often use words, phrases, and sentences to marginalize specific societal groups. Marginalized groups include powerful entities such as government officials accused of legal violations and marginalized individuals such as women. The language used in these headlines frequently involves negative connotations or dysphemisms, which emphasize undesirable traits or behaviors. Additionally, question sentences are employed in headlines to further marginalize these groups. This analysis highlights how linguistic choices in news titles reinforce societal biases and marginalize both dominant and disadvantaged groups.
Making computers automatically extract latent scientific knowledge from literature is highly desired for future materials and chemical research in the artificial intelligence era. Herein, the natural language processing (NLP)‐based machine learning technique to build language models and automatically extract hidden information regarding perovskite solar cell (PSC) materials from 29 060 publications is employed. The concept that there are light‐absorbing materials, electron‐transporting materials, and hole‐transporting materials in PSCs is successfully learned by the NLP‐based machine learning model without a time‐consuming human expert training process. The NLP model highlights a hole‐transporting material that receives insufficient attention in the literature, which is then elaborated via density functional theory calculations to provide an atomistic view of the perovskite/hole‐transporting layer heterostructures and their optoelectronic properties. Finally, the above results are confirmed by device experiments. The present study demonstrates the viability of NLP as a universal machine learning tool to extract useful information from existing publications.
Computer engineering. Computer hardware, Control engineering systems. Automatic machinery (General)
In the spreading dynamics of previous fashion trends, adoption researchers have neglected to consider that some individuals may behave differently from popular tendencies, which is called opposite-trend adoption behavior. To explore the dissemination mechanisms of the behavior, we first establish the adoption-against-trend model. Additionally, an edge division theory based on the adoption of opposite trends was proposed to quantitatively analyze this unique dissemination mechanism. This study presents three different degrees of opposite trends, each highlighting unique spreading scenarios. In the case of a strong opposite trend, no spreading occurs. In the case of a weak opposite trend, limited contact will accelerate information spreading, but it will not alter the mode of spreading. Nevertheless, in the case of a moderately opposite trend, the degree of the opposite trend alters the mode of spreading. Meanwhile, a cross-phase transition occurs. The findings of this paper can be applied to various areas, including social media and commercial trades.
This paper introduces a novel information-theoretic perspective on the relationship between prominent group fairness notions in machine learning, namely statistical parity, equalized odds, and predictive parity. It is well known that simultaneous satisfiability of these three fairness notions is usually impossible, motivating practitioners to resort to approximate fairness solutions rather than stringent satisfiability of these definitions. However, a comprehensive analysis of their interrelations, particularly when they are not exactly satisfied, remains largely unexplored. Our main contribution lies in elucidating an exact relationship between these three measures of (un)fairness by leveraging a body of work in information theory called partial information decomposition (PID). In this work, we leverage PID to identify the granular regions where these three measures of (un)fairness overlap and where they disagree with each other leading to potential tradeoffs. We also include numerical simulations to complement our results.
We present a new notion $R_\ell$ of higher-order common information, which quantifies the information that $\ell\geq 2$ arbitrarily distributed random variables have in common. We provide analytical lower bounds on $R_3$ and $R_4$ for jointly Gaussian distributed sources and provide computable lower bounds for $R_\ell$ for any $\ell$ and any sources. We also provide a practical method to estimate the lower bounds on, e.g., real-world time-series data. As an example, we consider EEG data acquired in a setup with competing acoustic stimuli. We demonstrate that $R_3$ has descriptive properties that is not in $R_2$. Moreover, we observe a linear relationship between the amount of common information $R_3$ communicated from the acoustic stimuli and to the brain and the corresponding cortical activity in terms of neural tracking of the envelopes of the stimuli.
Recent progress has shown that the generalization error of the Gibbs algorithm can be exactly characterized using the symmetrized KL information between the learned hypothesis and the entire training dataset. However, evaluating such a characterization is cumbersome, as it involves a high-dimensional information measure. In this paper, we address this issue by considering individual sample information measures within the Gibbs algorithm. Our main contribution lies in establishing the asymptotic equivalence between the sum of symmetrized KL information between the output hypothesis and individual samples and that between the hypothesis and the entire dataset. We prove this by providing explicit expressions for the gap between these measures in the non-asymptotic regime. Additionally, we characterize the asymptotic behavior of various information measures in the context of the Gibbs algorithm, leading to tighter generalization error bounds. An illustrative example is provided to verify our theoretical results, demonstrating our analysis holds in broader settings.
Juan Marcelo Ibujés-Villacís, Antonio Franco-Crespo
A permanent challenge for business organizations is to transform, adapt to the environment and innovate, so knowing the factors that influence the ability to innovate is relevant information. In this sense, the objective of this article is to determine and conceptualize the decisive factors that interact in a systemic way in the management of innovation in the manufacturing industry. The research has a qualitative approach, with a descriptive and transversal scope. In the first place, a review of the literature was carried out that allowed delimiting the management of innovation in the company in three main categories. Second, the categories were characterized, and subcategories and properties were identified, taking the manufacturing companies of Pichincha, Ecuador as the subject of study. This characterization was carried out through a qualitative study that takes the Grounded Theory as a reference, using research techniques: questionnaires, interviews, and documentary research. The results reveal that the relevant factors for the management of innovation in the company can be grouped into three main categories: knowledge management (KM), innovation capabilities (IC) and financial performance (FP). The subcategories that explain KM are policies and strategies, organizational structure, technology, people, incentive systems, organizational culture, and communication. The subcategories that explain IC are research and development capacity, management capacity, resource availability, human talent management, staff skills and technological capacity. The subcategories that explain the FP are sales and costs. This research contributes to the field of innovation management with new information and theory for action and emphasizes the systemic vision of innovation management and the key factors for the development of innovations in the Ecuadorian industrial sector, with the purpose of strengthening the theoretical and empirical advances of innovation management in the company.
Service life of the pavement can be predicted with proper temperature estimation of the pavement structure. Asphalt mixture displays a different modulus upon temperature change due to its viscoelasticity. The purpose of this study is to estimate such a temperature. Methodology in here includes one with the solution of heat conduction theory of the asphalt, and the other one statistical method. Results show that there is not a significant difference between the results made by two different methods. As a result of the model performance, the error range between the observed value and the predicted value is within the range suggested by other studies, so it is judged that the performance of the model is good. However, the prediction accuracy in the month with the highest and lowest temperatures per year was low. It seems that follow-up actions on this part will be necessary in the future. This study is expected to be used in various ways for road management in Hungary, and it is expected to be a basic study for the construction of road meteorological information system.
Akshay Seshadri, Felix Leditzky, Vikesh Siddhu
et al.
The capacity of a channel characterizes the maximum rate at which information can be transmitted through the channel asymptotically faithfully. For a channel with multiple senders and a single receiver, computing its sum capacity is possible in theory, but challenging in practice because of the nonconvex optimization involved. To address this challenge, we investigate three topics in our study. In the first part, we study the sum capacity of a family of multiple access channels (MACs) obtained from nonlocal games. For any MAC in this family, we obtain an upper bound on the sum rate that depends only on the properties of the game when allowing assistance from an arbitrary set of correlations between the senders. This approach can be used to prove separations between sum capacities when the senders are allowed to share different sets of correlations, such as classical, quantum or no-signalling correlations. We also construct a specific nonlocal game to show that the approach of bounding the sum capacity by relaxing the nonconvex optimization can give arbitrarily loose bounds. Owing to this result, in the second part, we study algorithms for non-convex optimization of a class of functions we call Lipschitz-like functions. This class includes entropic quantities, and hence these results may be of independent interest in information theory. Subsequently, in the third part, we show that one can use these techniques to compute the sum capacity of an arbitrary two-sender MACs to a fixed additive precision in quasi-polynomial time. We showcase our method by efficiently computing the sum capacity of a family of two-sender MACs for which one of the input alphabets has size two. Furthermore, we demonstrate with an example that our algorithm may compute the sum capacity to a higher precision than using the convex relaxation.
Common information (CI) is ubiquitous in information theory and related areas such as theoretical computer science and discrete probability. However, because there are multiple notions of CI, a unified understanding of the deep interconnections between them is lacking. This monograph seeks to fill this gap by leveraging a small set of mathematical techniques that are applicable across seemingly disparate problems. In Part I, we review the operational tasks and properties associated with Wyner's and Gács-Körner-Witsenhausen's (GKW's) CI. In PartII, we discuss extensions of the former from the perspective of distributed source simulation. This includes the Rényi CI which forms a bridge between Wyner's CI and the exact CI. Via a surprising equivalence between the Rényi CI of order~$\infty$ and the exact CI, we demonstrate the existence of a joint source in which the exact CI strictly exceeds Wyner's CI. Other closely related topics discussed in Part II include the channel synthesis problem and the connection of Wyner's and exact CI to the nonnegative rank of matrices. In Part III, we examine GKW's CI with a more refined lens via the noise stability or NICD problem in which we quantify the agreement probability of extracted bits from a bivariate source. We then extend this to the $k$-user NICD and $q$-stability problems, and discuss various conjectures in information theory and discrete probability, such as the Courtade-Kumar, Li-Médard and Mossell-O'Donnell conjectures. Finally, we consider hypercontractivity and Brascamp-Lieb inequalities, which further generalize noise stability via replacing the Boolean functions therein by nonnnegative functions. The key ideas behind the proofs in Part III can be presented in a pedagogically coherent manner and unified via information-theoretic and Fourier-analytic methods.
Marcio Roberto de Lima, Silvania Sousa do Nascimento
Abstract In this article we track the effects of incorporating digital games to the initial teachers training in Physics during a course at a Brazilian public university. To this purpose, we used the production of empirical data from field observations and the preparation of reports by students during our Research-Action. We systematized our sources of information using open coding in the ATLAS.ti software and this result was discussed under the contributions of the Actor-Network Theory of Bruno Latour and collaborators. In our analysis, we identified the affectation of the pedagogical meanings of future teachers related to digital games and their incorporation into a proposal for teaching Physics.
This story is inspired by the growing feasibility of Decentralised Autonomous Corporations (DACs), operating by means of distributed blockchain technologies. The story is set in the near future where a decentralised corporation – powered by machine-learning algorithms and fed on an unending stream of data – has entirely penetrated the fabric of society. Ultimately, however, it is the narcissism of humans – their insatiable need to be recognised in some way – that drives the exponential power of the corporation. Some of the themes that emerge from the story are: 1) the production of social media content, 2) the dangers of corporate personhood, 3) the nature of human and non-human agency, 4) the nature of truth in the context of the information age, and 5) the potential impact of fully autonomous technologies.