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Abstract Objective Despite Canada being an important energy producer, not all Canadians can access or afford adequate levels of energy services at home to meet their needs, maintain healthy indoor temperatures, and live a decent life—a situation known as energy poverty. Depending on the measure, 6–19% of Canadian households face energy poverty. Health risks associated with energy poverty are documented in countries with milder climates. This study explores, for the first time in the Canadian context, the association between energy poverty and health. Methods Cross-sectional data are from the 2018 Canadian Housing Survey. Analyses are conducted on a sample weighted to represent 14 million Canadian households. The associations between expenditure-based and self-reported measures of energy poverty and self-rated general and mental health were assessed using logistic regression models, adjusted for potential confounding variables. Results The odds of rating one’s general (OR: 1.48; 95%CI: 1.29, 1.70) and mental (OR: 1.21; 1.04, 1.41) health as poor are significantly higher for Canadian adults in households with a high share of energy expenditure to income. The likelihood of poor general and mental health was significantly higher for those dissatisfied with the energy efficiency of their dwelling, and with their ability to maintain a comfortable temperature both in the winter and in the summer. Conclusion Exposure to energy poverty is associated with significantly increased likelihood of poor general and mental health. Given the high proportion of Canadian households facing energy poverty, with demonstrated implications for population health, tackling energy poverty is essential for an equitable energy transition and for climate resilience. more...

The COVID-19 pandemic led to lockdown measures where congregational faith-based activities were prohibited. With time, the collateral impacts of confinement emerged as priorities, and impositions had to be balanced with the collaboration of the population. In this process, faith-based organizations played a key role in encouraging their congregations to adhere to lockdown measures while fostering their mental wellbeing and resilience. This paper describes the process of establishing a collaborative negotiation among the Montreal Regional Public Health Unit, the police, and the Muslim and Jewish communities, examining the role of mediation in this context. Despite some obstacles, such as communication difficulties and decision-making limitations, the collaborative approach seems to buffer the escalation of intercommunity tension and to promote communities’ commitment to physical distancing measures and should be considered in times of pandemic for a more inclusive public health approach. more...

This essay is part of a special issue entitled “Looking Backward, Looking Forward: HSNS at 50,” edited by Erika Lorraine Milam.

Ultrathin membranes with subnanometer pores enabling molecular size-selective separation were generated on surfaces via electron-induced cross-linking of self-assembled monolayers (SAMs). The evolution of p-terphenylthiol (TPT) SAMs on Au(111) surfaces into cross-linked monolayers was observed with a scanning tunneling microscope. As the irradiation dose was increased, the cross-linked regions continued to grow and a large number of subnanometer voids appeared. Their equivalent diameter is 0.5 ± 0.2 nm and the areal density is ≈1.7 × 1017 m−2. Supported by classical molecular dynamics simulations, we propose that these voids may correspond to free volumes inside a cross-linked monolayer. more...

Attributing individual deaths to extreme heat events (EHE) in Canada and elsewhere is important for understanding the risk factors, protective interventions, and burden of mortality associated with climate change. However, there is currently no single mechanism for identifying individual deaths due to EHE and different agencies have taken different approaches, including (1) vital statistics coding based on medical certificates of death, (2) probabilistic methods, and (3) enhanced surveillance. The 2018 EHE in Montréal provides an excellent case study to compare EHE deaths identified by these different approaches. There were 353 deaths recorded in the vital statistics data over an 8-day period, of which 102 were potentially attributed to the EHE by at least one approach and 251 were not attributed by any approach. Only nine of the 102 deaths were attributed to the EHE by all three approaches, 23 were attributed by two approaches, and 70 were attributed by only one approach. Given that there were approximately 50 excess deaths during the EHE, it remains unclear exactly which of the total 353 deaths should be attributed to the extreme temperatures. These results highlight the need for a more systematic and cooperative approach to EHE mortality in Canada, which will continue to increase as the climate changes.RéSUMé: L’attribution des décès individuels aux épisodes de chaleur accablante (ECA) au Canada et ailleurs est importante pour comprendre les facteurs de risque, les interventions de protection et le fardeau de la mortalité associés aux changements climatiques. Cependant, il n’existe actuellement aucun mécanisme unique pour identifier les décès individuels dus à l’ECA et différentes agences ont adopté différentes approches, notamment (1) le codage des statistiques de l’état civil basé sur les certificats médicaux de décès, (2) des méthodes probabilistes et (3) une surveillance renforcée. L’ECA 2018 à Montréal fournit une excellente étude de cas pour comparer les décès ECA identifiés par ces différentes approches. Il y a eu 353 décès enregistrés dans les données des statistiques de l’état civil sur une période de 8 jours, dont 102 ont été potentiellement attribués à l’ECA par au moins une approche et 251 n’ont été attribués par aucune approche. Seuls neuf des 102 décès ont été attribués à l’ECA par les trois approches, 23 ont été attribués par deux approches et 70 ont été attribués par une seule approche. Étant donné qu’il y a eu environ 50 décès supplémentaires pendant l’ECA, on ne sait pas exactement lequel des 353 décès au total doit être attribué aux températures extrêmes. Ces résultats soulignent la nécessité d’une approche plus systématique et coopérative de la mortalité ECA au Canada, qui continuera d’augmenter à mesure que le climat change. more...

Field effect transistors (FETs) based on 2D materials are of great interest for applications in ultrathin electronic and sensing devices. Here we demonstrate the possibility to add optical switchability to graphene FETs (GFET) by functionalizing the graphene channel with optically switchable azobenzene molecules. The azobenzene molecules were incorporated to the GFET channel by building a van der Waals heterostructure with a carbon nanomembrane (CNM), which is used as a molecular interposer to attach the azobenzene molecules. Under exposure with 365 nm and 455 nm light, azobenzene molecules transition between cis and trans molecular conformations, respectively, resulting in a switching of the molecular dipole moment. Thus, the effective electric field acting on the GFET channel is tuned by optical stimulation and the carrier density is modulated., Optically switchable graphene FET: Via van der Waals assembly of an approximately 1 nm thick azobenzene functionalized molecular nanosheets with single layer graphene, optically responsive field‐effect transistors are demonstrated. The electrical carrier density of these devices can be modulated using optical stimuli, 365 nm and 455 nm light. more...

David Kaiser traces the roots of government support for science, in the first of a series of essays on how the past 150 years have shaped the research system, marking Nature’s 150th anniversary. David Kaiser traces the roots of government support for science, in the first of a series of essays on how the past 150 years have shaped the research system, marking Nature’s 150th anniversary. more...

Massive scalar fields provide excellent dark matter candidates, whose dynamics are often explored analytically and numerically using nonrelativistic Schr\"{o}dinger-Poisson (SP) equations in a cosmological context. In this paper, starting from the nonlinear and fully relativistic Klein-Gordon-Einstein (KGE) equations in an expanding universe, we provide a systematic framework for deriving the SP equations, as well as relativistic corrections to them, by integrating out `fast modes' and including nonlinear metric and matter contributions. We provide explicit equations for the leading-order relativistic corrections, which provide insight into deviations from the SP equations as the system approaches the relativistic regime. Upon including the leading-order corrections, our equations are applicable beyond the domain of validity of the SP system, and are simpler to use than the full KGE case in some contexts. As a concrete application, we calculate the mass-radius relationship of solitons in scalar dark matter and accurately capture the deviations of this relationship from the SP system towards the KGE one., Comment: 20 pages, 5 figures, plus appendices more...

It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. While the abundance of light elements indicates that the Universe was radiation dominated during Big Bang Nucleosynthesis (BBN), there is scant evidence that the Universe was radiation dominated prior to BBN. It is therefore possible that the cosmological history was more complicated, with deviations from the standard radiation domination during the earliest epochs. Indeed, several interesting proposals regarding various topics such as the generation of dark matter, matter-antimatter asymmetry, gravitational waves, primordial black holes, or microhalos during a nonstandard expansion phase have been recently made. In this paper, we review various possible causes and consequences of deviations from radiation domination in the early Universe - taking place either before or after BBN - and the constraints on them, as they have been discussed in the literature during the recent years., 67 pages, 18 figures. v2: Discussion and references added. Accepted for publication in The Open Journal of Astrophysics more...

Managing the outbreak of COVID-19 in India constitutes an unprecedented health emergency in one of the largest and most diverse nations in the world. On May 4, 2020, India started the process of releasing its population from a national lockdown during which extreme social distancing was implemented. We describe and simulate an adaptive control approach to exit this situation, while maintaining the epidemic under control. Adaptive control is a flexible counter-cyclical policy approach, whereby different areas release from lockdown in potentially different gradual ways, dependent on the local progression of the dis- ease. Because of these features, adaptive control requires the ability to decrease or increase social distancing in response to observed and projected dynamics of the disease outbreak. We show via simulation of a stochastic Susceptible-Infected-Recovered (SIR) model and of a synthetic intervention (SI) model that adaptive control performs at least as well as immediate and full release from lockdown starting May 4 and as full release from lockdown after a month (i.e., after May 31). The key insight is that adaptive response provides the option to increase or decrease socioeconomic activity depending on how it affects disease progression and this freedom allows it to do at least as well as most other policy alternatives. We also discuss the central challenge to any nuanced release policy, including adaptive control, specifically learning how specific policies translate into changes in contact rates and thus COVID-19's reproductive rate in real time. more...

Inverter voltage control techniques, including Volt-Watt and Volt-VAR, have been developed to support higher penetration integration of photovoltaic (PV) generation. These techniques typically focus on voltage regulation as measured at the point of common coupling (PCC). Implementing voltage control with distributed inverters within a low voltage network is challenging due to voltage rise between the PCC and the electrical connection point (ECP). This paper proposes a voltage correction and control method for distributed PV microinverters in a low voltage network by utilizing readily available data measurements, i.e., voltage and power at the ECP of inverters. It is shown that this method could reduce unnecessary PV microinverter tripping and power curtailment while supporting voltage control schemes at the PCC. Test results are provided from simulation-only scenarios and a power-hardware-in-the-loop test platform. more...

This paper examines how various private patrons intervened to support research in gravitational physics from the late 1940s through the early 1960s. Our analysis centers primarily on two wealthy and eccentric businessmen, Roger Babson and Agnew Bahnson, and their efforts to galvanize the study of gravitation. Not only did these patrons provide generous funding at a time when the subject of gravitation received few other institutional sources of support; they also helped to knit together a research community. Moreover, we trace the evolution of their patronage efforts, as scientists and patrons revised their arrangements to address what came to seem weak or ineffective features of the original efforts. These unusual philanthropic efforts played an outsized role in spurring what has been called the renaissance of general relativity during the middle decades of the twentieth century. more...

In 1945 leaders of the American Institute of Physics conceived a bold experiment: a magazine that would help unify an increasingly balkanized discipline.

QUANTUM LEGACIES: Dispatches from an Uncertain World by David Kaiser (with a Foreword by Alan Lightman). Chicago, IL: University of Chicago Press, 2020. 360 pages, 47 halftones. Hardcover; $26.00. ISBN: 9780226698052. *The stories of real humans involved in the discovery of secrets of the quantum realm are highlighted by David Kaiser's book Quantum Legacies: Dispatches from an Uncertain World. Kaiser is both an accomplished theoretical physicist and a historian of science, holding a dual professorship at MIT. The book is a collection of his essays written for a popular audience knit into a theme of how discovery of quantum ideas has taken place in a changing world by intriguing personalities. *Scientific discovery never takes place in a vacuum, but rather is guided and spurred on by the very pressures experienced by its human discoverers, including personal family tragedies such as the suicide of Paul Dirac's brother and societal upheavals such as the Nazi takeover in Germany leading to World War II. Kaiser describes his own journey and how it was affected by the politics and pressures of the Cold War. Indeed, as a particle physicist who also grew up during the Cold War, I could relate to many of the dynamics described by Kaiser. He notes that funding for the Superconducting Super Collider project in the 1990s was canceled partly because the Cold War ended, and the US funding for "world prestige" projects was cut, in favor of more "world collaborative" projects, such as the International Space Station. Given that my own career trajectory was influenced by this decision, reading this book certainly caused some personal reflections. *The book is divided into four sections: Quanta, Calculating, Matter, and Cosmos. The essays in Quanta include the early years of quantum mechanics, highlighting the lives of Paul Dirac, the Briton who discovered the equation describing electrons; Erwin Schrödinger, the Austrian who used a half-dead, half-alive cat in a box to describe the bizarre idea of quantum mechanical superposition; and Bruno Pontecorvo, the Italian who applied Schrödinger's idea to the ghostly neutrino particle to predict its spontaneously changing identity. The interesting personal lives of these men and the historical context in which their scientific pursuits took place provide a dramatic reading. Indeed, the probabilistic aspects of the quantum mechanics they studied reflected the uncertainty of the world they lived in. The final essay in Quanta describes an experiment that Kaiser personally participated in, proving that entangled photons obey the probabilistic predictions of quantum mechanics, and not deterministic laws proposed by Isaac Newton (1600s) through Albert Einstein (twenieth century). Enriching the story, Kaiser connects quasars from the remote edges of our visible universe to the Roque de los Muchachos Observatory on the Canary island of La Palma to show that the world of physics involves interesting physical settings. *Calculating is an interesting collection of essays on how national defense priorities from the end of World War II through the Cold War drove university physics enrollments, the development of atomic bombs and computers, and even the personal lives of the contributing physicists. For example, David Bohm, whose textbook Quantum Theory took great pains to explain its conceptual and philosophical foundations, was forced to flee the US to Brazil during the Communist purges. No updated editions of his textbook were published, a rather unusual history for an initially very popular textbook. Nearly all other textbooks on quantum mechanics emphasized its calculational properties, relegating subtle conceptual points to lie outside the domain of physics. Kaiser finds this rather unfortunate, since these very points are where several key questions in quantum theory remain unanswered. And this is what draws students to physics. Kaiser ends this discussion with an essay on Fritjof Capra's The Tao of Physics, a bestselling popular book on physics and Eastern philosophy, showing that the mystical elements of quantum theory are precisely what many people find so fascinating about it. *Matter is a collection of stories on the discovery of elementary particles with a focus on the Higgs particle. The Standard Model of elementary particles grew out of Murray Gell-Mann's idea from symmetry arguments that fundamental particles lie inside the neutrons and protons of the atomic nucleus. He gave them the name quarks. The quark model quickly became very successful at predicting the existence of other quark bound states. However, the theoretical model worked only if the quarks and all other particles in nature were massless. This quandary could be resolved, claimed several physicists including the Scotsman Peter Higgs, if there existed a field permeating all of space which caused particles to become massive. Higgs also predicted that this field would have its own associated particle. Since the Standard Model successfully met every other test, the search for the Higgs particle became the driving force behind new experimental designs, including the Superconducting Super Collider project that was ultimately canceled in 1993. However, the Large Hadron Collider at CERN (the European Organization for Nuclear Research), located in Geneva, would be the project that successfully found the Higgs particle in 2012. Kaiser uses this as a bridge to his final set of essays on the cosmos, since the Higgs field itself leads naturally to an idea that explains the weakness of gravity compared to other fundamental forces, and how one might understand the earliest moments of the cosmos. *Cosmos is an appropriate final set of essays for Kaiser's book, since the quantum ideas prove to have profound implications for the entire history of the universe. This is also the most colorful set of essays from Kaiser, since he includes discussions on the search for extraterrestrial life, gravitation and black holes, the big bang theory, and even creation and evolution. The chapter, "The Other Evolution Wars," is particularly interesting in its descriptions of the interactions between science and religious faith. While Kaiser points out that some cosmologists, beginning with the Belgian priest Georges Lemaître, found a satisfying fit between their growing scientific view of an evolving cosmos and their theology, the situation soon and unfortunately changed to an acrimonious one with the advent of the modern creation science movement. Kaiser discusses the resurgent biblical literalism that denies an older cosmos and the big bang theory, and then briefly mentions "intelligent design." Unfortunately, Kaiser seems to lump the critics together rather haphazardly. Concerning his internet perusal of critiques from creationist web sites, he writes: "I found plenty of sites eager to sell the recent anti-big-bang books, along with DVDs such as The Privileged Planet, proffering ‘evidence' of supernatural intelligent design" (pp. 248-49). *This statement implies that Kaiser assumes that the authors of The Privileged Planet are anti-big-bang adherents, which they are not. The issues of purpose, design, and intentionality are certainly at stake. It is noteworthy to me that the book by Peter Ward and Donald Brownlee (Rare Earth), and that by Guillermo Gonzales & Jay Richards (The Privileged Planet), are very similar in thrust, emphasizing aspects of planet Earth that appear rather unique in the cosmos, but because they diverge on the question of purpose, design, and intentionality, one is considered mainstream science (Rare Earth) and the other, creationist literature (The Privileged Planet). Although I personally do not promote apparent design in nature as an argument for supernatural design, I am saddened by all the harsh critiques, whether it is leveled against those who hold that science is in support of faith or whether it is leveled against good science in order to protect doctrinal positions. There do not need to be combative relationships between scientists and Christians, but scientists such as Kaiser are very much aware that they exist. *Cosmos includes a chapter on the amazing developments in modern cosmology. Since I did a book review of Roger Penrose's Fashion, Faith, and Fantasy in the New Physics of the Universe [PSCF 69, no. 3 (2017): 187-89], I was happy to see a discussion of his Conformal Cyclical Cosmology (CCC). Theoretical physicists respect the contributions of Roger Penrose, given his and Stephen Hawking's contributions to our understanding of space-time from general relativity. But the elegant ideas offered by Penrose in his CCC appear to not withstand the exacting toll of precision data in modern cosmology, and we await further ideas that will. *The book wraps up with some recent noteworthy events: the discovery of gravitational waves in 2015 and the death of Stephen Hawking in 2018. While the former heralded a new age in modern multimessenger astronomy, the latter has brought us to the end of an era in which one of the most brilliant minds took on the challenge of understanding the universe, overcoming incredible odds and challenges. Again, the experience of personal struggles of one person did not prevent great accomplishments in scientific thought, and, in fact, may have contributed to it. Quantum Legacies ends with a positive note. Overall, despite the sometimes-awkward collection of essays, the book is an enriching read. *Reviewed by Steven Ball, Professor of Physics, LeTourneau University, Longview, TX 75607 more...

To estimate the cost and return on investment (ROI) of an intervention targeting work-family conflict (WFC) in the extended care industry.Costs to deliver the intervention during a group-randomized controlled trial were estimated, and data on organizational costs-presenteeism, health care costs, voluntary termination, and sick time-were collected from interviews and administrative data. Generalized linear models were used to estimate the intervention's impact on organizational costs. Combined, these results produced ROI estimates. A cluster-robust confidence interval (CI) was estimated around the ROI estimate.The per-participant cost of the intervention was $767. The ROI was -1.54 (95% CI: -4.31 to 2.18). The intervention was associated with a $668 reduction in health care costs (P 0.05).This paper builds upon and expands prior ROI estimation methods to a new setting. more...

Sustainable land use needs a manageable nexus of knowledge from planning practice, policy makers, the private economy, and civic society, as well as from scientific research. This is mutually dependent on the communicative and collaborative turn in spatial planning as well as by transdisciplinary research approaches. This paper offers an approach how to organise knowledge management and co-production of knowledge in the context of complex land use decisions. Therefore, a prototype of an internet-based knowledge platform is introduced based on a theoretical reflection of concepts for integrated information and knowledge management, as well as on practical experiences derived from a German case study. We conclude that sustainable land use requires Planning Support Systems (PSS) that combine transdisciplinary perspectives in order to co-produce robust knowledge. This also implies a transdisciplinary design of PSS. Challenges of implementation are discussed and further research is specified. more...

Plastics and microplastics increasingly gain importance due to their perils and wide distribution in the marine environment. Microfibers account for the largest percentage of anthropogenic-induced microparticles, which inter alia, consist of plastic, and are found in deep-sea sediments. However, the sinking of fibers from the surface through the water column to the seafloor is still poorly understood. The present study investigates microfibers extracted from sediment trap samples, which were deployed in the North Atlantic Subtropical Gyre (NASG). The average result of eleven analyzed samples showed 913 microfibers per gram of collected particle flux material, with a predominant fiber length shorter than 1 mm (75.6%) and a distribution maximum between 0.2 and 0.4 mm. Further, the average number of microfibers found in this study was used to derive microfiber fluxes for the NASG based on the deployment time of the sediment trap. Extrapolating the computed flux of 94 microfibers m−2 day−1 to the entire NASG area would correspond to a total microfiber mass flux of 9800 t a−1 or 73 × 1013 microfibers a−1 of sinking microfibers through the water column. These findings offer an extended application of sediment traps to monitor microfiber fluxes, which reveals the opportunity to investigate the mechanism driving sinking of microfibers and microplastics into the deep open ocean. more...

Physical review / D 102(4), 043528 (1-24) (2020). doi:10.1103/PhysRevD.102.043528, We have conducted extensive lattice simulations to study the postinflation dynamics of multifield models involving nonminimal couplings. We explore the parameter dependence of preheating in these models and describe the various time scales that control such nonlinear processes as energy transfer, rescattering, and the approach to radiation domination and thermalization. In the limit of large nonminimal couplings (ξI∼100), we find that efficient transfer of energy from the inflaton condensate to radiative degrees of freedom, emergence of a radiation-dominated equation of state, and the onset of thermalization each consistently occur within Nreh≲3 e-folds after the end of inflation, largely independent of the values of the other couplings in the models. The exception is the case of negative ellipticity, in which there is a misalignment between the dominant direction in field space along which the system evolves and the larger of the nonminimal couplings ξI. In those cases, the field-space-driven parametric resonance is effectively shut off. More generally, the competition between the scalar fields’ potential and the field-space manifold structure can yield interesting phenomena such as two-stage resonances. Across many regions of parameter space, we find efficient re-scattering between the distinct fields, leading to a partial memory loss of the shape of the initial fluctuation spectrum. Despite the explosive particle production, which can lead to a quick depletion of the background energy density, the nonlinear processes do not induce any superhorizon correlations after the end of inflation in these models, which keeps predictions for cosmic microwave background observables unaffected by the late-time amplification of isocurvature fluctuations. Hence the excellent agreement between primordial observables and recent observations is preserved for this class of models, even when we consider postinflation dynamics., Published by Inst.302363, Melville, NY more...

A massive, nonrelativistic scalar field in an expanding spacetime is usually approximated by a pressureless perfect fluid, which leads to the standard conclusion that such a field can play the role of cold dark matter. In this paper, we systematically study these approximations, incorporating subleading corrections. We provide two equivalent effective descriptions of the system, each of which offers its own advantages and insights: (i) A nonrelativistic effective field theory (EFT) with which we show that the relativistic corrections induce an effective self-interaction for the nonrelativistic field. As a byproduct, our EFT also allows one to construct the exact solution, including oscillatory behavior, which is often difficult to achieve from the exact equations. (ii) An effective (imperfect) fluid description, with which we demonstrate that, for a perturbed Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe: (a) The pressure is small but nonzero (and positive), even for a free theory with no tree-level self-interactions. (b) The sound speed of small fluctuations is also nonzero (and positive), reproducing already known leading-order results, correcting a subdominant term, and identifying a new contribution that had been omitted in previous analyses. (c) The fluctuations experience a negative effective bulk viscosity. The positive sound speed and the negative bulk viscosity act in favor of and against the growth of overdensities, respectively. The net effect may be considered a smoking gun for ultra-light dark matter., Comment: 28 pages, 5 figures, plus appendices more...

We analyze the onset of inflation for a simple single-field model when the system begins with significant inhomogeneities on length scales shorter than the initial Hubble radius. We incorporate certain nonlinear interactions among the coupled degrees of freedom by using the nonperturbative Hartree approximation. Consistent with recent, more computationally intensive numerical-relativity studies, we find inflation to be robust for large-field models, even when the system begins with significant structure on sub-Hubble scales. We consider the space of initial conditions $(\ensuremath{\varphi}({t}_{0}),\stackrel{\ifmmode \dot{}\else \textperiodcentered \fi{}}{\ensuremath{\varphi}}({t}_{0}))$, where $\ensuremath{\varphi}$ is the vacuum expectation value of the quantized field that drives inflation. Although some regions of $(\ensuremath{\varphi}({t}_{0}),\stackrel{\ifmmode \dot{}\else \textperiodcentered \fi{}}{\ensuremath{\varphi}}({t}_{0}))$ that would have yielded sufficient inflation in the absence of inhomogeneities fail to do so when backreaction from inhomogeneities is incorporated, an equal volume of such regions succeeds in producing sufficient inflation which did not do so in the absence of inhomogeneities. For large-field models, in other words, the total volume of the space of initial conditions $(\ensuremath{\varphi}({t}_{0}),\stackrel{\ifmmode \dot{}\else \textperiodcentered \fi{}}{\ensuremath{\varphi}}({t}_{0}))$ that yields sufficient inflation is conserved when we incorporate nonlinear backreaction from inhomogeneities, compared to the case in which inhomogeneities are neglected. more...

We study the post-inflation dynamics of multifield models involving nonminimal couplings using lattice simulations to capture significant nonlinear effects like backreaction and rescattering. We measure the effective equation of state and typical time-scales for the onset of thermalization, which could affect the usual mapping between predictions for primordial perturbation spectra and measurements of anisotropies in the cosmic microwave background radiation. For large values of the nonminimal coupling constants, we find efficient particle production that gives rise to nearly instantaneous preheating. Moreover, the strong single-field attractor behavior that was previously identified persists until the end of preheating, thereby suppressing typical signatures of multifield models. We therefore find that predictions for primordial observables in this class of models retain a close match to the latest observations., Comment: 6 pages, 7 figures. References added and minor edits made to match version to be published in Physical Review Letters more...

Quantum key distribution (QKD) involving polarized photons could be vulnerable to a jamming (or denial-of-service) attack, in which a third party applies an external magnetic field to rotate the plane of polarization of photons headed toward one of the two intended recipients. Sufficiently large Faraday rotation of one of the polarized beams would prevent Alice and Bob from establishing a secure quantum channel. We investigate requirements to induce such rotation both for free-space transmission and for transmission via optical fiber, and find reasonable ranges of parameters in which a jamming attack could be successful against fiber-based QKD, even for systems that implement automated recalibration for polarization-frame alignment. The jamming attack could be applied selectively and indefinitely by an adversary without revealing her presence, and could be further combined with various eavesdropping attacks to yield unauthorized information., 8 pages, 1 figure. References added and further discussion included of how the jamming attack could be combined with various eavesdropping attacks more...

Purpose: To estimate the effects of a workplace initiative to reduce work–family conflict on employee performance. Design: A group-randomized multisite controlled experimental study with longitudinal follow-up. Setting: An information technology firm. Participants: Employees randomized to the intervention (n = 348) and control condition (n = 345). Intervention: An intervention, “Start. Transform. Achieve. Results.” to enhance employees’ control over their work time, to increase supervisors’ support for this change, and to increase employees’ and supervisors’ focus on results. Methods: We estimated the effect of the intervention on 9 self-reported employee performance measures using a difference-in-differences approach with generalized linear mixed models. Performance measures included actual and expected hours worked, absenteeism, and presenteeism. Results: This study found little evidence that an intervention targeting work–family conflict affected employee performance. The only significant effect of the intervention was an approximately 1-hour reduction in expected work hours. After Bonferroni correction, the intervention effect is marginally insignificant at 6 months and marginally significant at 12 and 18 months. Conclusion: The intervention reduced expected working time by 1 hour per week; effects on most other employee self-reported performance measures were statistically insignificant. When coupled with the other positive wellness and firm outcomes, this intervention may be useful for improving employee perceptions of increased access to personal time or personal wellness without sacrificing performance. The null effects on performance provide countervailing evidence to recent negative press on work–family and flex work initiatives. more...

Aims To examine how institutional constraints, comprising federal actions and states’ substance abuse policy environments, influence states’ decisions to activate Medicaid reimbursement codes for screening and brief intervention for risky substance use in the United States. Methods A discrete-time duration model was used to estimate the effect of institutional constraints on the likelihood of activating the Medicaid reimbursement codes. Primary constraints included federal Screening, Brief Intervention and Referral to Treatment (SBIRT) grant funding, substance abuse priority, economic climate, political climate and interstate diffusion. Study data came from publicly available secondary data sources. Results Federal SBIRT grant funding did not affect significantly the likelihood of activation (P = 0.628). A $1 increase in per-capita block grant funding was associated with a 10-percentage point reduction in the likelihood of activation (P = 0.003) and a $1 increase in per-capita state substance use disorder expenditures was associated with a 2-percentage point increase in the likelihood of activation (P = 0.004). States with enacted parity laws (P = 0.016) and a Democratic-controlled state government were also more likely to activate the codes. Conclusion In the United States, the determinants of state activation of Medicaid Screening, Brief Intervention and Referral to Treatment (SBIRT) reimbursement codes are complex, and include more than financial considerations. Federal block grant funding is a strong disincentive to activating the SBIRT reimbursement codes, while more direct federal SBIRT grant funding has no detectable effects. more...

Sediment cores from the central Beibu Gulf and its northern coastal mangroves were analyzed for polycyclic aromatic hydrocarbons (PAH), the organo-chlorine pesticides dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), and polychlorinated biphenyls (PCB), to reconstruct the organic pollution history of developing south-west China. Reflecting regional development, in the gulf ∑PAH (38-74 ng g(-1)) decreased towards the surface after peak concentrations near 10 cm, while ∑DDT (ND - 0.5 ng g(-1)) increased due to fresh inputs, and HCB (ND - 0.04 ng g(-1)) occurred only in surface sediments. Profiles in mangrove sediments showed a continuing local scale increase in ∑PAH (29-438 ng g(-1)) as well as ∑DDT (0.2-41.0 ng g(-1)) and HCB (0.01-1.01 ng g(-1)) pollution, despite some variability. No trend was evident for ∑PCB (ND - 0.22 ng g(-1)), which was not detected in the central gulf. Calculated loads estimate that 2816 ng cm(-2) PAHs and 7 ng cm(-2) DDTs are stored in depositional areas of the Beibu Gulf. Mangrove sediments, threatened by land-use-change, contain 1400-4600 ng cm(-2) PAHs and 34-39 ng cm(-2) DDTs. more...

SETTING: Montréal. INTERVENTION: The lack of common knowledge about what public health does is a hindrance to its recognition and capacity to act. Montréal’s regional public health department set an explicit goal to clarify and better communicate its specific contributions when it developed its 2016–2021 action plan. This article briefly describes the efforts made to classify public health practice, introduces a typology of public health interventions and discusses its application and benefits. OUTCOMES: The typology that was developed defines 29 types of interventions grouped into four categories: direct action targeting the population; advocacy (persuading partners to take action); support (helping partners take action); collaboration (taking action with partners). The analysis of Montreal’s most recent action plan, completely drafted in terms of the typology, provides an insightful characterization of public health practice. Globally, four out of five interventions target partners (indirect), with more than half falling within the support category. Other indirect interventions are divided almost equally between advocacy and collaboration. Following a rigorous planning process and enforcing the use of the typology also had a significant structuring effect on the organization and its teams and enabled greater synergy with partners from other sectors. IMPLICATIONS: Very few people are familiar with everything public health does, sometimes not even the responsible political decision-makers. This situation poses a threat to the survival of its prevention mission. The typology of public health interventions is an innovative tool that can be used to better inform the public and decision-makers. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.17269/s41997-019-00268-3) contains supplementary material, which is available to authorized users. more...

Bell's inequality was originally derived under the assumption that experimenters are free to select detector settings independently of any local "hidden variables" that might affect the outcomes of measurements on entangled particles. This assumption has come to be known as "measurement independence" (also referred to as "freedom of choice" or "settings independence"). For a two-setting, two-outcome Bell test, we derive modified Bell inequalities that relax measurement independence, for either or both observers, while remaining locally causal. We describe the loss of measurement independence for each observer using the parameters $M_1$ and $M_2$, as defined by Hall in 2010, and also by a more complete description that adds two new parameters, which we call $\hat{M}_1$ and $\hat{M}_2$, deriving a modified Bell inequality for each description. These "relaxed" inequalities subsume those considered in previous work as special cases, and quantify how much the assumption of measurement independence needs to be relaxed in order for a locally causal model to produce a given violation of the standard Bell-Clauser-Horne-Shimony-Holt (Bell-CHSH) inequality. We show that both relaxed Bell inequalities are tight bounds on the CHSH parameter by constructing locally causal models that saturate them. For any given Bell inequality violation, the new two-parameter and four-parameter models each require significantly less mutual information between the hidden variables and measurement settings than previous models. We conjecture that the new models, with optimal parameters, require the minimum possible mutual information for a given Bell violation. We further argue that, contrary to various claims in the literature, relaxing freedom of choice need not imply superdeterminism., 26pp, 7 figures. Minor edits to match published version more...

In this Letter, we present a cosmic Bell experiment with polarization-entangled photons, in which measurement settings were determined based on real-time measurements of the wavelength of photons from high-redshift quasars, whose light was emitted billions of years ago, the experiment simultaneously ensures locality. Assuming fair sampling for all detected photons and that the wavelength of the quasar photons had not been selectively altered or previewed between emission and detection, we observe statistically significant violation of Bell's inequality by $9.3$ standard deviations, corresponding to an estimated $p$ value of $\lesssim 7.4 \times 10^{-21}$. This experiment pushes back to at least $\sim 7.8$ Gyr ago the most recent time by which any local-realist influences could have exploited the "freedom-of-choice" loophole to engineer the observed Bell violation, excluding any such mechanism from $96\%$ of the space-time volume of the past light cone of our experiment, extending from the big bang to today., 9 pages, 4 figures, plus Supplemental Material (16 pages, 8 figures). Matches version to be published in Physical Review Letters more...

We analyze the flow into inflation for generic "single-clock" systems, by combining an effective field theory approach with a dynamical-systems analysis. In this approach, we construct an expansion for the potential-like term in the effective action as a function of time, rather than specifying a particular functional dependence on a scalar field. We may then identify fixed points in the effective phase space for such systems, order-by-order, as various constraints are placed on the $M$th time derivative of the potential-like function. For relatively simple systems, we find significant probability for the background spacetime to flow into an inflationary state, and for inflation to persist for at least 60 efolds. Moreover, for systems that are compatible with single-scalar-field realizations, we find a single, universal functional form for the effective potential, $V (\phi)$, which is similar to the well-studied potential for power-law inflation. We discuss the compatibility of such dynamical systems with observational constraints., Comment: 32 pages, 12 figures. Minor edits to match published version more...

OBJECTIVES: Since 2004, the Montreal heat response plan (MHRP) has been developed and implemented on the Island of Montreal to reduce heat-related health effects in the general population. In this paper, we aimed to assess the barriers and facilitators to implementation of the MHRP and evaluate the awareness of key elements of the plan by healthcare professionals and individuals from vulnerable populations. METHODS: Data were gathered from monitoring reports and a questionnaire administered to managers of healthcare institutions and healthcare workers in Montreal-area health and social services institutions. Individual interviews and focus groups with healthcare workers and with individuals with schizophrenia or suffering from drug or alcohol dependencies were performed. Data were categorized according to predefined subthemes. Coding matrices were then used to determine the most frequently occurring elements in the subthemes. RESULTS: Our results indicate that actions are progressively implemented each year in the healthcare network. Intensification of surveillance for signs of heat-related illness is the most frequently reported measure. Identification and prioritization of clientele and homecare patients are identified as a challenge, as is ensuring the availability of sufficient personnel during a heat wave. Analysis of practice and awareness in healthcare professionals reveals that preventive measures are known and applied by the personnel. Individuals from vulnerable population groups were not uniformly aware of preventive measures, and consequently, variability was observed in their application. CONCLUSION: The framework proposed in this study revealed valuable information that can be useful to improve plans aimed at reducing heat-related health effects in the population. more...

In this paper we develop a formalism for studying the nonrelativistic limit of relativistic field theories in a systematic way. By introducing a simple, nonlocal field redefinition, we transform a given relativistic theory, describing a real, self-interacting scalar field, into an equivalent theory, describing a complex scalar field that encodes at each time both the original field and its conjugate momentum. Our low-energy effective theory incorporates relativistic corrections to the kinetic energy as well as the backreaction of fast-oscillating terms on the behavior of the dominant, slowly varying component of the field. Possible applications of our new approach include axion dark matter, though the methods developed here should be applicable to the low-energy limits of other field theories as well., 31pp. References added, and 3 appendices added, showing (a) how to implement the field redefinition as a canonical transformation, (b) how to develop the effective field theory using a local field redefinition, and (c) how to use a further field redefinition to compare our results with those of Mukaida, Takimoto, and Yamada more...