Criminal Code reform of HIV non-disclosure is urgently needed: Social science perspectives on the harms of HIV criminalization in Canada.

The criminalization of HIV non-disclosure represents a significant issue of concern among people living with HIV, those working across the HIV sector, public health practitioners, and health and human rights advocates around the world. Recently, the government of Canada began a review of the criminal law regarding HIV non-disclosure and invited feedback from the public about potential reforms to the Criminal Code. In light of this public consultation, this commentary examines social science research from Canadian scholars that documents the intersecting damaging effects of HIV criminalization. Canadian social scientists and other researchers have shown that HIV criminalization is applied in uneven and discriminatory ways, impedes HIV prevention efforts, perpetuates HIV stigma, and has a damaging impact on the daily lives of people living with HIV. We argue that there is an urgent need for reforms that will significantly restrict how the criminal law is applied to HIV non-disclosure.

RéSUMé: La criminalisation de la non-divulgation du VIH est une question très préoccupante pour les personnes vivant avec le VIH, celles qui travaillent dans le secteur du VIH, les praticiens et praticiennes de la santé publique et les porte-parole de la santé et des droits de la personne du monde entier. Récemment, le gouvernement du Canada a amorcé un examen du droit criminel portant sur la non-divulgation du VIH et a invité le public à commenter d'éventuelles réformes du Code criminel. À la lumière de cette consultation publique, notre commentaire porte sur les études en sciences sociales menées au Canada qui font état des effets croisés préjudiciables de la criminalisation du VIH. Des spécialistes des sciences sociales et d'autres chercheuses et chercheurs canadiens ont montré que la criminalisation du VIH est appliquée de façon inégale et discriminatoire, qu'elle nuit aux efforts de prévention du VIH, qu'elle perpétue la stigmatisation liée au VIH et qu'elle a des effets dommageables sur la vie quotidienne des personnes vivant avec le VIH. Nous soutenons qu'il existe un besoin urgent de réformes pour restreindre de façon appréciable l'application du droit criminel à la non-divulgation du VIH.

Using machine learning to retrospectively predict self-reported gambling problems in Quebec.

BACKGROUND AND AIMS: Participating in online gambling is associated with an increased risk for experiencing gambling-related harms, driving calls for more effective, personalized harm prevention initiatives. Such initiatives depend on the development of models capable of detecting at-risk online gamblers. We aimed to determine whether machine learning algorithms can use site data to detect retrospectively at-risk online gamblers indicated by the Problem Gambling Severity Index (PGSI). DESIGN: Exploratory comparison of six prominent supervised machine learning methods (decision trees, random forests, K-nearest neighbours, logistic regressions, artificial neural networks and support vector machines) to predict problem gambling risk levels reported on the PGSI. SETTING: Lotoquebec.com (formerly espacejeux.com), an online gambling platform operated by Loto-Québec (a provincial Crown Corporation) in Quebec, Canada. PARTICIPANTS: N = 9145 adults (18+) who completed the survey measure and placed at least one bet using real money on the site. MEASUREMENTS: Participants completed the PGSI, a self-report questionnaire with validated cut-offs denoting a moderate-to-high-risk (PGSI 5+) or high-risk (PGSI 8+) for experiencing past-year gambling-related problems. Participants agreed to release additional data about the preceding 12 months from their user accounts. Predictor variables (144) were derived from users' transactions, apparent betting behaviours, listed demographics and use of responsible gambling tools on the platform. FINDINGS: Our best classification models (random forests) for the PGSI 5+ and 8+ outcome variables accounted for 84.33% (95% CI = 82.24-86.41) and 82.52% (95% CI = 79.96-85.08) of the total area under their receiver operating characteristic curves, respectively. The most important factors in these models included the frequency and variability of participants' betting behaviour and repeat engagement on the site. CONCLUSIONS: Machine learning algorithms appear to be able to classify at-risk online gamblers using data generated from their use of online gambling platforms. They may enable personalized harm prevention initiatives, but are constrained by trade-offs between their sensitivity and precision.

Diamond formation kinetics in shock-compressed C─H─O samples recorded by small-angle x-ray scattering and x-ray diffraction.

Extreme conditions inside ice giants such as Uranus and Neptune can result in peculiar chemistry and structural transitions, e.g., the precipitation of diamonds or superionic water, as so far experimentally observed only for pure C─H and H2O systems, respectively. Here, we investigate a stoichiometric mixture of C and H2O by shock-compressing polyethylene terephthalate (PET) plastics and performing in situ x-ray probing. We observe diamond formation at pressures between 72 ± 7 and 125 ± 13 GPa at temperatures ranging from ~3500 to ~6000 K. Combining x-ray diffraction and small-angle x-ray scattering, we access the kinetics of this exotic reaction. The observed demixing of C and H2O suggests that diamond precipitation inside the ice giants is enhanced by oxygen, which can lead to isolated water and thus the formation of superionic structures relevant to the planets' magnetic fields. Moreover, our measurements indicate a way of producing nanodiamonds by simple laser-driven shock compression of cheap PET plastics.

Electronic transport coefficients from density functional theory across the plasma plane.

We investigate the thermopower and Lorenz number of hydrogen with Kohn-Sham density functional theory (DFT) across the plasma plane toward the near-classical limit, i.e., weakly degenerate and weakly coupled states. Our results are in concordance with certain limiting values for the Lorentz plasma, a model system which only considers electron-ion scattering. Thereby, we clearly show that the widely used method of calculating transport properties via the Kubo-Greenwood (KG) formalism does not capture electron-electron scattering processes. Our discussion also addresses the inadequateness of assuming a Drude-like frequency behavior for the conductivity of nondegenerate plasmas by revisiting the relaxation time approximation within kinetic theory.

Ionization and transport in partially ionized multicomponent plasmas: Application to atmospheres of hot Jupiters.

We study ionization and transport processes in partially ionized multicomponent plasmas. The plasma composition is calculated via a system of coupled mass-action laws. The electronic transport properties are determined by the electron-ion and electron-neutral transport cross sections. The influence of electron-electron scattering is considered via a correction factor to the electron-ion contribution. Based on these data, the electrical and thermal conductivities as well as the Lorenz number are calculated. For the thermal conductivity, we consider also the contributions of the translational motion of neutral particles and of the dissociation, ionization, and recombination reactions. We apply our approach to a partially ionized plasma composed of hydrogen, helium, and a small fraction of metals (Li, Na, Ca, Fe, K, Rb, and Cs) as typical for atmospheres of hot Jupiters. We present results for the plasma composition and the transport properties as a function of density and temperature and then along typical P-T profiles for the outer part of the hot Jupiter HD 209458b. The electrical conductivity profile allows revising the Ohmic heating power related to the fierce winds in the planet's atmosphere. We show that the higher temperatures suggested by recent interior models could boost the conductivity and thus the Ohmic heating power to values large enough to explain the observed inflation of HD 209458b.

Gibbs-ensemble Monte Carlo simulation of H2-H2O mixtures.

The miscibility gap in hydrogen-water mixtures is investigated by conducting Gibbs-ensemble Monte Carlo simulations with analytical two-body interaction potentials between the molecular species. We calculate several demixing curves at pressures below 150 kbar and temperatures of 1000 K ≤T≤ 2000 K. Despite the approximations introduced by the two-body interaction potentials, our results predict a large miscibility gap in hydrogen-water mixtures at similar conditions as found in experiments. Our findings are in contrast to those from ab initio simulations and provide a renewed indication that hydrogen-water immiscibility regions may have a significant impact on the structure and evolution of ice giant planets like Uranus and Neptune.

Gibbs-ensemble Monte Carlo simulation of H_{2}-He mixtures.

We explore the performance of the Gibbs-ensemble Monte Carlo simulation technique by calculating the miscibility gap of H_{2}-He mixtures with analytical exponential-six potentials. We calculate several demixing curves for pressures up to 500 kbar and for temperatures up to 1800K and predict a H_{2}-He miscibility diagram for the solar He abundance for temperatures up to 1500K and determine the demixing region. Our results are in good agreement with ab initio simulations in the nondissociated region of the phase diagram. However, the particle number necessary to converge the Gibbs-ensemble Monte Carlo method is yet too large to offer a feasible combination with ab initio electronic structure calculation techniques, which would be necessary at conditions where dissociation or ionization occurs.

Paramagnetic-to-Diamagnetic Transition in Dense Liquid Iron and Its Influence on Electronic Transport Properties.

The electrical σ and thermal conductivity λ of liquid iron are calculated with spin-polarized density-functional-theory-based simulations over a significant pressure and temperature range using the Kubo-Greenwood formalism. We show that a paramagnetic state is stable in the liquid up to high temperatures at ambient pressure and that the discrepancy between experimental results and spin-degenerate simulations for σ and λ of more than 30% are reduced to within 10% with lower values resulting from the spin-polarized simulations. Along the 3700 K isotherm, we explore the persistence of magnetic fluctuations toward high densities, and beyond 20-50 GPa the liquid becomes diamagnetic, which suggests the existence of a continuous paramagnetic-to-diamagnetic transition. This transition exerts a significant influence on the physical properties of liquid iron, especially on σ and λ, and is potentially of high relevance for dynamo processes in Mercury and Mars.

The HIV self-testing debate: where do we stand?

BACKGROUND: Emphasis on HIV testing as a gateway to prevention, treatment and care has grown tremendously over the past decade. In turn, this emphasis on testing has created a demand for new policies, programs, and technologies that can potentially increase access to and uptake of HIV testing. HIV self-testing (HST) technologies have gained important momentum following the approval of the over-the-counter self-tests in the United States, the UK, and France. While the renewed interest in HST has given rise to a number of high quality reviews of empirical studies conducted on this topic, we have yet to find an article that captures the extent of the debate on HST. MAPPING THE DEBATE: A critical review of the literature on HST was conducted and organized into three categories based on the focus of the article: 1) Empirical research, 2) Arguments, and 3) Context. We focused exclusively on the second category which included ethical analyses, policy analyses, editorials, opinion pieces, commentaries, letters to the editor and so forth. 10 lines of argument on HST were identified in the literature: 1) Individual - Public Health, 2) Strengths - Limits, 3) Benefits - Harms, 4) Screening - Testing, 5) Target - Market, 6) Health Care - Industry, 7) Regulation - Restriction, 8) Resource-Rich Settings - Resource-Limited Settings, 9) Ethical - Unethical, and 10) Exceptionalism - Normalization. Each line of argument is presented and discussed in the paper. CONCLUSION: We conclude by providing examples of critical questions that should be raised in order to take the debate to another level and generate new ways of thinking about HST.

Free energy model for solid high-pressure phases of carbon.

Analytic free energy models for three solid high-pressure phases--diamond, body centered cubic phase with eight atoms in the unit cell (BC8), and simple cubic (SC)--are developed using density functional theory. We explicitly include anharmonic effects by performing molecular dynamics simulations and investigate their density and temperature dependence in detail. Anharmonicity in the nuclear motion shifts the phase transitions significantly compared to the harmonic approximation. Furthermore, we apply a thermodynamically constrained correction that brings the equation of state in accordance with diamond anvil cell experiments. The performance of our thermodynamic functions is validated against Hugoniot experiments.

Ab initio calculation of thermodynamic potentials and entropies for superionic water.

We construct thermodynamic potentials for two superionic phases of water [with body-centered cubic (bcc) and face-centered cubic (fcc) oxygen lattice] using a combination of density functional theory (DFT) and molecular dynamics simulations (MD). For this purpose, a generic expression for the free energy of warm dense matter is developed and parametrized with equation of state data from the DFT-MD simulations. A second central aspect is the accurate determination of the entropy, which is done using an approximate two-phase method based on the frequency spectra of the nuclear motion. The boundary between the bcc superionic phase and the ices VII and X calculated with thermodynamic potentials from DFT-MD is consistent with that directly derived from the simulations. Differences in the physical properties of the bcc and fcc superionic phases and their impact on interior modeling of water-rich giant planets are discussed.

Equation of state and phase diagram of ammonia at high pressures from ab initio simulations.

We present an equation of state as well as a phase diagram of ammonia at high pressures and high temperatures derived from ab initio molecular dynamics simulations. The predicted phases of ammonia are characterized by analyzing diffusion coefficients and structural properties. Both the phase diagram and the subsequently computed Hugoniot curves are compared to experimental results. Furthermore, we discuss two methods that allow us to take into account nuclear quantum effects, which are of considerable importance in molecular fluids. Our data cover pressures up to 330 GPa and a temperature range from 500 K to 10,000 K. This regime is of great interest for interior models of the giant planets Uranus and Neptune, which contain, besides water and methane, significant amounts of ammonia.

Do canadian researchers and the lay public prioritize biomedical research outcomes equally? A choice experiment.

PURPOSE: To quantify and compare the preferences of researchers and laypeople in Canada regarding the outcomes of basic biomedical research. METHOD: In autumn 2010, the authors conducted a cross-sectional, national survey of basic biomedical researchers funded by Canada's national health research agency and a representative sample of Canadian citizens to assess preferences for research outcomes across five attributes using a discrete choice experiment. Attributes included advancing scientific knowledge (assessed by published papers); building research capacity (assessed by trainees); informing decisions in the health products industry (assessed by patents); targeting economic, health, or scientific priorities; and cost. The authors reduced a fractional factorial design (18 pairwise choices plus an opt-out option) to three blocks of six. They also computed part worth utilities, differences in predicted probabilities, and willingness-to-pay values using nested logit models. RESULTS: Of 3,260 potential researchers, 1,749 (53.65% response rate) completed the questionnaire, along with 1,002 citizens. Researchers and citizens prioritized high-quality scientific outcomes (papers, trainees) over other attributes. Both groups disvalued research targeted at economic priorities relative to health priorities. Researchers granted a premium to proposals targeting scientific priorities. CONCLUSIONS: Citizens and researchers fundamentally prioritized the same outcomes for basic biomedical research. Notably, they prioritized traditional scientific outcomes and disvalued the pursuit of economic returns. These findings have implications for how academic medicine assigns incentives and value to basic health research and how biomedical researchers and the public may jointly contribute to setting the future research agenda.

Public health intelligence and the detection of potential pandemics.

This article considers contemporary developments in public health intelligence (PHI), especially their focus on health events of pandemic potential. It argues that the sociological study of PHI can yield important insights for the sociology of pandemics. PHI aims to detect health events as (or even before) they unfold. Whilst its apparatuses envelope traditional public health activities, such as epidemiological surveillance, they increasingly extend to non-traditional public health activities such as data-mining in electronically mediated social networks. With a focus on non-traditional PHI activities, the article first situates the study of PHI in relation to the sociology of public health. It then discusses the conceptualisation and actualisation of pandemics, reflecting on how public health professionals and organisations must equip themselves with diverse allies in order to realise the claims they make about pandemic phenomena. Finally, using the analytic tools of actor-network theory, sites for future empirical research that can contribute to the sociology of pandemics are suggested.

Leveraging the "living laboratory": on the emergence of the entrepreneurial hospital.

For years, scholars have debated the "commercial ethos" in higher education, and the rise of the entrepreneurial university. But what of the "entrepreneurial hospital"? Largely unnoticed by scholars, this unique organisational form differs from the entrepreneurial university in some significant ways, not least in its capacity to use its innovations, and to count patients-and even patient populations-amongst its human capital. Accordingly, this article provides an initial conceptualisation of the entrepreneurial hospital, along with an exploration of its larger implications. Using twenty-six semi-structured interviews with key-informants (2008-2009), who work in two networked organisations within a single academic health science system in a Canadian province, our analysis identifies distinctive characteristics of an entrepreneurial hospital. Informed by grounded theory, especially situational analysis, we derive from our data an illustration of potentially incommensurate understandings of the entrepreneurial hospital's resources. On one hand, our study participants view patients and patient populations as a resource for research, linking its value to the contribution it can make to improved, more cost-effective care. On the other hand, some also see commercial potential in this resource. In both cases, exploitation is accompanied by perceived obligations to make proper use of patient populations, and to "give back" to the public-at-large, including through the entrepreneurial search for new ways of mobilising the resources of publicly-funded health care. Thus, a key task of the entrepreneurial hospital is to invent and mediate new uses for its care infrastructure and the unique resource constituted by patient populations. By drawing together care and research in new ways, the entrepreneurial hospital promises increased capacity for biomedical innovation. Yet, as it invents and mediates new uses for patient populations and health care infrastructure, the entrepreneurial hospital stands to significantly redefine both systems of care and the bonds of social solidarity.

Dynamical screening and ionic conductivity in water from ab initio simulations.

We present a method to calculate ionic conductivities of complex fluids from ab initio simulations. This is achieved by combining density functional theory molecular dynamics simulations with polarization theory. Conductivities are then obtained via a Green-Kubo formula using time-dependent effective charges of electronically screened ions. The method is applied to two different phases of warm dense water. We observe large fluctuations in the effective charges; protons can transport effective charges greater than +e for ultrashort time scales. Furthermore, we compare our results with a simpler model of ionic conductivity in water that is based on diffusion coefficients. Our approach can be directly applied to study ionic conductivities of electronically insulating materials of arbitrary composition, e.g., complex molecular mixtures under such extreme conditions that occur deep inside giant planets.