On the Number of Bins in Equilibria for Signaling Games

We investigate the equilibrium behavior for the decentralized quadratic cheap talk problem in which an encoder and a decoder, viewed as two decision makers, have misaligned objective functions. In prior work, we have shown that the number of bins under any equilibrium has to be at most countable, generalizing a classical result due to Crawford and Sobel who considered sources with density supported on $[0,1]$. In this paper, we refine this result in the context of exponential and Gaussian sources. For exponential sources, a relation between the upper bound on the number of bins and the misalignment in the objective functions is derived, the equilibrium costs are compared, and it is shown that there also exist equilibria with infinitely many bins under certain parametric assumptions. For Gaussian sources, it is shown that there exist equilibria with infinitely many bins.Comment: 25 pages, single colum

Sharing the spirit? Sociospatial polarization and expressed enthusiasm for the Olympic Games

This article seeks to contribute to the literature that assesses the local outcomes of hosting hallmark events by examining the expressed levels of enthusiasm for the year 2000 Olympic Games within Sydney. We report on the results of a telephone survey of 658 Sydney residents conducted in February 1998 designed to measure enthusiasm for the 2000 Olympic Games. As of February 1998, it appeared that enthusiasm for the 2000 Olympics remained strong in Sydney, thereby providing support to the views of those who regard hallmark events as a psychological mechanism to assist residents to feel a sense of pride in their city and nation. However, higher levels of enthusiasm were recorded in the lower socioeconomic status suburbs of Western Sydney than in the higher status suburbs of the North Shore. These differences were not statistically differentiated by economic indicators (income, occupation, and education levels) but were significant by association with social variables such as country of birth, age, and marital and family status. Several implications of these results are considered within the literature debating the outcome of hosting hallmark events

Optimality of entropic uncertainty relations

The entropic uncertainty relation proven by Maassen and Uffink for arbitrary pairs of two observables is known to be non-optimal. Here, we call an uncertainty relation optimal, if the lower bound can be attained for any value of either of the corresponding uncertainties. In this work we establish optimal uncertainty relations by characterising the optimal lower bound in scenarios similar to the Maassen-Uffink type. We disprove a conjecture by Englert et al. and generalise various previous results. However, we are still far from a complete understanding and, based on numerical investigation and analytical results in small dimension, we present a number of conjectures.Comment: 24 pages, 10 figure

Factors Associated with the Emergence of K65R in Patients with HIV-1 Infection Treated with Combination Antiretroviral Therapy Containing Tenofovir

Background. The human immunodeficiency virus type 1 reverse-transcriptase mutation K65R is a single-point mutation that has become more frequent after increased use of tenofovir disoproxil fumarate (TDF). We aimed to identify predictors for the emergence of K65R, using clinical data and genotypic resistance tests from the Swiss HIV Cohort Study. Methods. A total of 222 patients with genotypic resistance tests performed while receiving treatment with TDF-containing regimens were stratified by detectability of K65R (K65R group, 42 patients; undetected K65R group, 180 patients). Patient characteristics at start of that treatment were analyzed. Results. In an adjusted logistic regression, TDF treatment with nonnucleoside reverse-transcriptase inhibitors and/or didanosine was associated with the emergence of K65R, whereas the presence of any of the thymidine analogue mutations D67N, K70R, T215F, or K219E/Q was protective. The previously undescribed mutational pattern K65R/G190S/Y181C was observed in 6 of 21 patients treated with efavirenz and TDF. Salvage therapy after TDF treatment was started for 36 patients with K65R and for 118 patients from the wild-type group. Proportions of patients attaining human immunodeficiency virus type 1 loads <50 copies/mL after 24 weeks of continuous treatment were similar for the K65R group (44.1%; 95% confidence interval, 27.2%-62.1%) and the wild-type group (51.9%; 95% confidence interval, 42.0%-61.6%). Conclusions. In settings where thymidine analogue mutations are less likely to be present, such as at start of first-line therapy or after extended treatment interruptions, combinations of TDF with other K65R-inducing components or with efavirenz or nevirapine may carry an enhanced risk of the emergence of K65R. The finding of a distinct mutational pattern selected by treatment with TDF and efavirenz suggests a potential fitness interaction between K65R and nonnucleoside reverse-transcriptase inhibitor-induced mutation

Long-Term Trends of HIV Type 1 Drug Resistance Prevalence among Antiretroviral Treatment-Experienced Patients in Switzerland

Background. Accurate quantification of the prevalence of human immunodeficiency virus type 1 (HIV-1) drug resistance in patients who are receiving antiretroviral therapy (ART) is difficult, and results from previous studies vary. We attempted to assess the prevalence and dynamics of resistance in a highly representative patient cohort from Switzerland. Methods. On the basis of genotypic resistance test results and clinical data, we grouped patients according to their risk of harboring resistant viruses. Estimates of resistance prevalence were calculated on the basis of either the proportion of individuals with a virologic failure or confirmed drug resistance (lower estimate) or the frequency-weighted average of risk group-specific probabilities for the presence of drug resistance mutations (upper estimate). Results. Lower and upper estimates of drug resistance prevalence in 8064 ART-exposed patients were 50% and 57% in 1999 and 37% and 45% in 2007, respectively. This decrease was driven by 2 mechanisms: loss to follow-up or death of high-risk patients exposed to mono- or dual-nucleoside reverse-transcriptase inhibitor therapy (lower estimates range from 72% to 75%) and continued enrollment of low-risk patients who were taking combination ART containing boosted protease inhibitors or nonnucleoside reverse-transcriptase inhibitors as first-line therapy (lower estimates range from 7% to 12%). A subset of 4184 participants (52%) had ⩾1 study visit per year during 2002-2007. In this subset, lower and upper estimates increased from 45% to 49% and from 52% to 55%, respectively. Yearly increases in prevalence were becoming smaller in later years. Conclusions. Contrary to earlier predictions, in situations of free access to drugs, close monitoring, and rapid introduction of new potent therapies, the emergence of drug-resistant viruses can be minimized at the population level. Moreover, this study demonstrates the necessity of interpreting time trends in the context of evolving cohort population

Bayesian network analysis reveals the interplay of intracranial aneurysm rupture risk factors

Clinical decision making regarding the treatment of unruptured intracranial aneurysms (IA) benefits from a better understanding of the interplay of IA rupture risk factors. Probabilistic graphical models can capture and graphically display potentially causal relationships in a mechanistic model. In this study, Bayesian networks (BN) were used to estimate IA rupture risk factors influences. From 1248 IA patient records, a retrospective, single-cohort, patient-level data set with 9 phenotypic rupture risk factors (n=790 complete entries) was extracted. Prior knowledge together with score-based structure learning algorithms estimated rupture risk factor interactions. Two approaches, discrete and mixed-data additive BN, were implemented and compared. The corresponding graphs were learned using non-parametric bootstrapping and Markov chain Monte Carlo, respectively. The BN models were compared to standard descriptive and regression analysis methods. Correlation and regression analyses showed significant associations between IA rupture status and patient’s sex, familial history of IA, age at IA diagnosis, IA location, IA size and IA multiplicity. BN models confirmed the findings from standard analysis methods. More precisely, they directly associated IA rupture with familial history of IA, IA size and IA location in a discrete framework. Additive model formulation, enabling mixed-data, found that IA rupture was directly influenced by patient age at diagnosis besides additional mutual influences of the risk factors. This study establishes a data-driven methodology for mechanistic disease modelling of IA rupture and shows the potential to direct clinical decision-making in IA treatment, allowing personalised prediction

A Randomized Trial of Simplified Maintenance Therapy with Abacavir, Lamivudine, and Zidovudine in Human Immunodeficiency Virus Infection

This randomized study evaluated the efficacy and tolerability of continued treatment with protease inhibitor plus nucleoside-analogue combination regimens (n = 79) or a change to the simplified regimen of abacavir-lamivudine-zidovudine (n = 84) in patients with suppressed human immunodeficiency virus type 1 (HIV-1) RNA for ⩾6 months who did not have the reverse transcriptase 215 mutation. After a median follow-up of 84 weeks, virologic failure was 6% in the continuation and 15% in the simplified group (P = .081). Previous zidovudine monotherapy or dual therapy and archived reverse transcriptase resistance mutations in HIV-1 DNA at baseline were significant predictors of failure. Study treatment was discontinued because of adverse events in 20% of the continuation and 7% of the simplified group (P = .021). Simplification to abacavir-lamivudine-zidovudine significantly decreased nonfasting cholesterol and triglyceride levels; however, this switch strategy carries a risk of virologic failure when treatment history or resistance testing suggest the presence of archived resistance mutations to the simplified regime

Brief Report: Switching From TDF to TAF in HIV/HBV-Coinfected Individuals With Renal Dysfunction-A Prospective Cohort Study.

Whereas tenofovir disoproxil fumarate (TDF) can lead to renal adverse events, tenofovir alafenamide (TAF) has a more favorable renal safety profile. However, the impact of replacing TDF with TAF on renal function and liver parameters among HIV/hepatitis B virus (HBV)-coinfected individuals with renal dysfunction remains unclear. We included all participants from the Swiss HIV Cohort Study with an HIV/HBV coinfection who switched from TDF to TAF and had an estimated glomerular filtration rate (eGFR) &lt;90 mL/min/1.73 m and a suppressed HIV viral load (&lt;200 cp/mL). We assessed changes in eGFR, urine protein-to-creatinine ratio, and alanine aminotransferase (ALT) after 1 year using mixed-effect models with interrupted time series. Among 106 participants (15.1% women, median age 53 years), eGFR was 60-89 mL/min/1.73 m in 84 (79.2%) and &lt;60 mL/min/1.73 m in 22 (20.8%) individuals at the time of switch. One year after the switch from TDF to TAF, individuals with an eGFR between 60 and 89 mL/min/1.73 m experienced increases in eGFR of 3.2 mL/min/1.73 m (95% confidence interval [CI] 1.2 to 5.2), whereas those with an eGFR &lt;60 mL/min/1.73 m experienced improvements of 6.2 mL/min/1.73 m (95% CI 2.4 to 10.0). Urine protein-to-creatinine ratio decreased overall (-6.3 mg/mmol, 95% CI -10.0 to -2.7), and ALT levels declined in patients with elevated baseline levels (-11.8 IU/L, 95% CI -17.3 to -6.4) 1 year after replacing TDF with TAF. Switching from TDF to TAF among HIV/HBV-coinfected individuals with renal impairment led to improvements in eGFR, a decline in proteinuria, and to ALT normalization in those with elevated ALT levels

Molecular Epidemiology Reveals Long-Term Changes in HIV Type 1 Subtype B Transmission in Switzerland

Background. Sequence data from resistance testing offer unique opportunities to characterize the structure of human immunodeficiency virus (HIV) infection epidemics. Methods. We analyzed a representative set of HIV type 1 (HIV-1) subtype B pol sequences from 5700 patients enrolled in the Swiss HIV Cohort Study. We pooled these sequences with the same number of sequences from foreign epidemics, inferred a phylogeny, and identified Swiss transmission clusters as clades having a minimal size of 10 and containing ⩾80% Swiss sequences. Results. More than one-half of Swiss patients were included within 60 transmission clusters. Most transmission clusters were significantly dominated by specific transmission routes, which were used to identify the following patient groups: men having sex with men (MSM) (38 transmission clusters; average cluster size, 29 patients) or patients acquiring HIV through heterosexual contact (HETs) and injection drug users (IDUs) (12 transmission clusters; average cluster size, 144 patients). Interestingly, there were no transmission clusters dominated by sequences from HETs only. Although 44% of all HETs who were infected between 1983 and 1986 clustered with injection drug users, this percentage decreased to 18% for 2003-2006 (P < .001), indicating a diminishing role of injection drug users in transmission among HETs over time. Conclusions. Our analysis suggests (1) the absence of a self-sustaining epidemic of HIV-1 subtype B in HETs in Switzerland and (2) a temporally decreasing clustering of HIV infections in HETs and IDU

Active involvement of nursing staff in reporting and grading complication-intervention events-Protocol and results of the CAMUS Pilot Nurse Delphi Study.

Objectives The aim of this study is to gain experienced nursing perspective on current and future complication reporting and grading in Urology, establish the CAMUS CCI and quality control the use of the Clavien-Dindo Classification (CDC) in nursing staff. Subjects and Methods The 12-part REDCap-based Delphi survey was developed in conjunction with expert nurse, urologist and methodologist input. Certified local and international inpatient and outpatient nurses specialised in urology, perioperative nurses and urology-specific advanced practice nurses/nurse practitioners will be included. A minimum sample size of 250 participants is targeted. The survey assesses participant demographics, nursing experience and opinion on complication reporting and the proposed CAMUS reporting recommendations; grading of intervention events using the existing CDC and the proposed CAMUS Classification; and rating various clinical scenarios. Consensus will be defined as ≥75% agreement. If consensus is not reached, subsequent Delphi rounds will be performed under Steering Committee guidance. Results Twenty participants completed the pilot survey. Median survey completion time was 58 min (IQR 40-67). The survey revealed that 85% of nursing participants believe nurses should be involved in future complication reporting and grading but currently have poor confidence and inadequate relevant background education. Overall, 100% of participants recognise the universal demand for reporting consensus and 75% hold a preference towards the CAMUS System. Limitations include variability in nursing experience, complexity of supplemental grades and survey duration. Conclusion The integration of experienced nursing opinion and participation in complication reporting and grading systems in a modern and evolving hospital infrastructure may facilitate the assimilation of otherwise overlooked safety data. Incorporation of focused teaching into routine nursing education will be essential to ensure quality control and stimulate awareness of complication-related burden. This, in turn, has the potential to improve patient counselling and quality of care