Past Controversies Research Articles

Roadmap to mercury free dentistry: Toxic past to a healthier future

Ever since its introduction, mercury has been widely used in dental practice because of its durability, ease of handling and placement, low cost, lower technical sensitivity compared to other restorative materials, antibacterial effect, etc. When esthetics are not an issue, it can be used in people of all ages, in stressed areas and with poor oral hygiene. However, concerns have been raised that amalgam causes mercury toxicity. At present, there is much controversy about the safety of dental amalgam and it has been shown to pose an occupational risk to patients, dentists, and their assistants. This review has attempted to summarize the past controversies and the current status of this restorative material in routine dental practice. It also discusses various alternatives to its use in terms of safety and esthetics.

Widespread support for a global species list with a formal governance system.

Taxonomic data are a scientific common. Unlike nomenclature, which has strong governance institutions, there are currently no generally accepted governance institutions for the compilation of taxonomic data into an accepted global list. This gap results in challenges for conservation, ecological research, policymaking, international trade, and other areas of scientific and societal importance. Consensus on a global list and its management requires effective governance and standards, including agreed mechanisms for choosing among competing taxonomies and partial lists. However, governance frameworks are currently lacking, and a call for governance in 2017 generated critical responses. Any governance system to which compliance is voluntary requires a high level of legitimacy and credibility among those by and for whom it is created. Legitimacy and credibility, in turn, require adequate and credible consultation. Here, we report on the results of a global survey of taxonomists, scientists from other disciplines, and users of taxonomy designed to assess views and test ideas for a new system of taxonomic list governance. We found a surprisingly high degree of agreement on the need for a global list of accepted species and their names, and consistent views on what such a list should provide to users and how it should be governed. The survey suggests that consensus on a mechanism to create, manage, and govern a single widely accepted list of all the world's species is achievable. This finding was unexpected given past controversies about the merits of list governance.

Decoding anxiety-impulsivity subtypes in preadolescent internalising disorders: findings from the Adolescent Brain Cognitive Development study.

Internalising disorders are highly prevalent emotional dysregulations during preadolescence but clinical decision-making is hampered by high heterogeneity. During this period impulsivity represents a major risk factor for psychopathological trajectories and may act on this heterogeneity given the controversial anxiety-impulsivity relationships. However, how impulsivity contributes to the heterogeneous symptomatology, neurobiology, neurocognition and clinical trajectories in preadolescent internalising disorders remains unclear. The aim was to determine impulsivity-dependent subtypes in preadolescent internalising disorders that demonstrate distinct anxiety-impulsivity relationships, neurobiological, genetic, cognitive and clinical trajectory signatures. We applied a data-driven strategy to determine impulsivity-related subtypes in 2430 preadolescents with internalising disorders from the Adolescent Brain Cognitive Development study. Cross-sectional and longitudinal analyses were employed to examine subtype-specific signatures of the anxiety-impulsivity relationship, brain morphology, cognition and clinical trajectory from age 10 to 12 years. We identified two distinct subtypes of patients who internalise with comparably high anxiety yet distinguishable levels of impulsivity, i.e. enhanced (subtype 1) or decreased (subtype 2) compared with control participants. The two subtypes exhibited opposing anxiety-impulsivity relationships: higher anxiety at baseline was associated with higher lack of perseverance in subtype 1 but lower sensation seeking in subtype 2 at baseline/follow-up. Subtype 1 demonstrated thicker prefrontal and temporal cortices, and genes enriched in immune-related diseases and glutamatergic and GABAergic neurons. Subtype 1 exhibited cognitive deficits and a detrimental trajectory characterised by increasing emotional/behavioural dysregulations and suicide risks during follow-up. Our results indicate impulsivity-dependent subtypes in preadolescent internalising disorders and unify past controversies about the anxiety-impulsivity interaction. Clinically, individuals with a high-impulsivity subtype exhibit a detrimental trajectory, thus early interventions are warranted.

Fifty Years of Human Rights Enforcement in Legal and Political Systems in Bangladesh: Past Controversies and Future Challenges.

This paper provides a synopsis of the human rights enforcement in Bangladesh, which marks its 50years in 2021 since its independence. After a theoretical background on how human rights are perceived as legal and political instruments, it critically discusses human rights provisions and explores the legal and institutional frameworks on human rights enforcement in Bangladesh-(re)construed in 50years (1971-2021). Finally, it divulges the controversies in human rights enforcement and a roadmap to address them by making some suggestions: multiple legislative, administrative, and judicial reforms are required to tackle human rights abuses to ensure punishment for the abusers and restitution for the victims. The paper concludes with the notion that the positive will of the relevant stakeholders (legislature, executive, and judiciary) is the key to upholding and protecting the human rights of Bangladeshi citizens. The significance of this paper lies in exploring the complexities associated with the laws and insular national politics, which often debars the enforcement of human rights and crucially compromises Bangladesh's ability to empower its citizens.

Ethics governance development: The case of the Menlo Report.

The 2012 Menlo Report was an effort in which a group of computer scientists, US government funders, and lawyers produced ethics guidelines for research in information and communications technology (ICT). Here we study Menlo as a case of what we call ethics governance in the making, finding that this process examines past controversies and enrols existing networks to connect the everyday practice of ethics with ethics as a form of governance. To create the Menlo Report, authors and funders relied on bricolage work with existing, available resources, which significantly shaped both the report's contents and impacts. Report authors were motivated by both forward- and backward-looking goals: enabling new data-sharing as well as addressing past controversies and their implications for the field's body of research. Authors also grappled with uncertainty about which ethical frameworks were appropriate and made the decision to classify much network data as human subjects data. Finally, the Menlo Report authors attempted to enrol multiple existing networks in governance through appeals to local research communities as well as taking steps towards federal rulemaking. The Menlo Report serves as a case study in how to study ethics governance in the making: with attention to resources, adaptation, and bricolage, and with a focus on both the uncertainties the process tries to repair, as well as the new uncertainties the process uncovers, which will become the site of future ethics work.

The Real Cost to Remain Competitive: BYU Confronts Racist Past

College sports is a multi-billion-dollar business, and universities are looking for ways to remain competitive, including recruiting and retaining athletes from historically underrepresented groups to predominantly white institutions (PWI), many of which have a documented history of excluding non-white students, including blacks, indigenous peoples, and other people of color (often referred to as BIPOC). This article will examine the legacy of the racist teachings, past controversies, and compromises of the Church of Jesus Christ of Latter-day Saints (LDS, Mormons) along with persistent struggles to shake off its 130-year-old racist past in efforts for its flagship school, Brigham Young University, to stay competitive in the lucrative Big 12 Athletic Conference. Deeply ingrained in the LDS culture is a politic of religious conservatism. Politics has often been intertwined with organized religion with much influence, and the LDS faith is no different. The cumulation of these interlocking systems generates thoughts, attitudes, and feelings that foster a racial climate at Brigham Young University where black students have reported feeling unsafe and unsupported. While this is a well-documented problem at predominately white institutions (PWIs) across the country, BYU is in many ways unique, given the discriminatory overt policies and practices employed for generations. We contend that the LDS Church’s history of racial marginalization and exclusion of black people made its way into the sports consciousness of the church’s flagship school and is not likely to change anytime soon. Understanding religion in the tradition of Charles Long as an orientation and utilizing Derrick Bell’s notion of racial realism are critical to our analyses. The confluence of politics, religion, race, and sport cannot be easily untangled.

Les vertiges cervicaux ont une réalité mais ce ne sont pas de vrais vertiges

Past controversies about the contribution of cervical spine to vertigo mainly resulted from confusion between vertigo and dizziness, and dogmatic belief that spine could not contribute to such conditions. In fact, whereas cervical disorders cannot induce vertigo with nystagmus (which are only explained by ENT or neurological disorders) they can conversely contribute to induce dizziness, through two main mechanisms: (1) impingement of vertebral artery during extremes or brisk cervical rotations (bow-hunter syndrome), especially in patients with loops of vertebral artery or arcuate foramen (ossification of atlo-occiptal ligament on the posterior aspect of axis, making an osseous arch around the vertebral artery). Marked sagittal C1-C2 instability can also reduce flow in vertebral arteries; (2) various abnormal proprioceptive inputs from cervical discs, uncus, zygapophyseal joints, muscles and ligaments or fascias, like the occipito-cervical membrane, can also foster dizziness. Patients with dizziness of putative cervical origin must first be examined by an ENT physician, and neurologist could also be asked to check for alternative explanations before classifying the dizziness as arising partly from the cervical spine and related structures. This possibility should not be denied, moreover as some spine surgery can induce a marked improvement of those dizziness in properly selected patients.

Voyager still breaking barriers decades after launch

As Voyagers 1 and 2 continue their epic journeys through interstellar space, they're resolving past controversies and even helping to spark a new one: the true shape of the heliosphere. Launched more than four decades ago, the two Voyager spacecraft keep expanding our horizons. Having flown past the giant planets in the late 1970s and 1980s, Voyagers 1 and 2 are now well beyond all their planetary targets, with Voyager 1 more than five times farther out than Neptune and Voyager 2 not far behind. “Every day is a new record for Voyager,” says the spacecraft’s project manager, Suzanne Dodd at the Jet Propulsion Laboratory near Los Angeles, CA. New data from the fabled Voyager spacecraft have fed a controversy over the geometry and activity of the heliosphere. Image credit: NASA/JPL-Caltech. “I never in my wildest dreams thought that I would still be working on Voyager fifty years after we wrote the proposal,” says Voyager researcher Stamatios “Tom” Krimigis of Johns Hopkins University in Laurel, MD. During the past decade, both spacecraft reached a new realm, entering the interstellar medium: the tenuous material that fills the vast space between the stars. There, the spacecraft continue to make new discoveries. The interstellar magnetic field has surprised researchers with both its strength and its direction, and the new data have even fed a controversy over the geometry and activity of the heliosphere—the Sun’s magnetic domain. Is the heliosphere the shape of a comet, as has long been assumed, or is it instead more spherical? And does it expand and contract when sunspots wax and wane, or is it more stable? The spacecraft have offered up some tantalizing clues. Voyager 2 left Earth in 1977, followed by Voyager 1. They weren’t the first spacecraft to reach the nearest of the giant planets—that honor …

Restorative and Transformative Justice Responses to Sexual Violence

Background: #MeToo movement raised the profiles of restorative justice (RJ) and transformative justice (TJ) in the United States (US) as approaches to repairing harm resulting from sexual violence that center survivors’ needs and emphasize meaningful accountability for persons responsible for harm. This focus on RJ and TJ as viable approaches to sexual violence represents a departure from carceral interventions, which has dominated the US public discourse for decades. Given the shift, mapping the current state of knowledge is critical for practice, policy and research. This scoping review aims to map the available literature to provide an overview of RJ and TJ as responses to sexual violence.
 Methods/Design: The proposed scoping review will be conducted in accordance with the Joana Briggs Institute methodology for scoping reviews (Peters, Godfrey-Smith, & Mcinerney, 2017). The concept of interest is the use of RJ and TJ as responses to sexual violence. This scoping review will include both peer-reviewed and grey literature. We will employ a standardized extraction form and represent the data using a descriptive summary, charts and tables that align with the stated objectives.
 Discussion: Since the #MeToo movement emerged in 2017, public interest in RJ and TJ as meaningful responses to sexual violence has grown. This comprehensive scoping review will systematically organize the literature in order to understand the current landscape of evidence related to these approaches. Given the transformative potential of these interventions, past controversies, and current public interest in the approaches, understanding the current state of knowledge is critical for practice, policy and research.

Negative emissions and the long history of carbon removal

AbstractRecent IPCC assessments highlight a key role for large‐scale carbon removal in meeting the objectives of the Paris Agreement. This focus on removal, also referred to as negative emissions, is suggestive of novel opportunities, risks, and challenges in addressing climate change, but tends to build on the narrow techno‐economic framings that characterize integrated assessment modeling. While the discussion on negative emissions bears important parallels to a wider and older literature on carbon sequestration and carbon sinks, this earlier scholarship—particularly from the critical social sciences—is seldom engaged with by the negative emissions research community. In this article, we survey this “long history” of carbon removal and seek to draw out lessons for ongoing research and the emerging public debate on negative emissions. We argue that research and policy on negative emissions should proceed not just from projections of the future, but also from an acknowledgement of past controversies, successes and failures. In particular, our review calls attention to the irreducibly political character of carbon removal imaginaries and accounting practices and urges acknowledgement of past experiences with the implementation of (small‐scale) carbon sequestration projects. Our review in this way highlights the importance of seeing continuity in the carbon removal discussion and calls for more engagement with existing social science scholarship on the subject. Acknowledging continuity and embracing an interdisciplinary research agenda on carbon removal are important aspects in making climate change mitigation research more responsible, and a precondition to avoid repeating past mistakes and failures.This article is categorized under: The Carbon Economy and Climate Mitigation > Benefits of Mitigation

The Culture Wars of Climate Change

Of late, there has been a growth in cultural expression about climate change – with the rise of climate fiction (‘cli-fi’); art and photography responding to changes in nature; musical anthems about climate change; plays and dramas about climate change; and environmental documentaries, and climate cinema. Drawing comparisons to past controversies over cultural funding, this paper considers the cultural wars over climate change. This article considers a number of cultural fields. Margaret Atwood made an important creative and critical contribution to the debate over climate change. The work examines Ian McEwan's novel, Solar, a tragi-comedy about authorship, invention, intellectual property, and climate science. After writing a history of Merchants of Doubt, Naomi Oreskes and Erik Conway have experimented with fiction – as well as history. This article focuses upon artistic works about climate change. It analyses James Balog’s work with the Extreme Ice Survey, which involved photography of glaciers under retreat in a warming world. The work was turned into a documentary called Chasing Ice. It also considers the artistic project of 350.org 'to transform the human rights and environmental issues connected to climate change into powerful art that gets people to stop, think and act.' The paper examines musical storytelling in respect of climate change. The paper explores dramatic works about climate change including Steve Waters' The Contingency Plan, Stephen Emmott's Ten Billion, and Andrew Bovell's When the Rain Stops Falling and Hannie Rayson’s Extinction. The paper also examines the role of documentary film-making. It also considers the cinematographic film, Beasts of the Southern Wild. Such a survey will enable a consideration of the larger question of whether creative art about climate change matters; and whether it is deserving of public funding.

Structure and ion transport of lithium-rich Li1+xAlxTi2−x(PO4)3 with 0.3

New solid state electrolytes are becoming increasingly sought after in the drive to replace flammable liquid electrolytes. To this end, several Li conducting solids have been identified as promising candidates including Li stuffed garnets and more recently Li-rich materials such as Li1+xAlxTi2−x(PO4)3 with 0.3<x <0.5. However, the structure/property relationships of LATP are incredibly sensitive to synthesis conditions and therefore challenging to optimise. In this joint computational and experimental investigation, we examine the structural sensitivities by modelling the site occupancies at varying temperature, which clarifies previously reported discrepancies of the crystal structures. Furthermore, we investigate the Li ion transport properties which have not reported computationally before. We confirm from our simulations that the migration pathway only involves the M1(6b) and M2(18e) site, in excellent agreement with the neutron diffraction data, clarifying all past controversies regarding the Li ion occupancies in LATP. Interestingly, we calculate low migration barriers (0.3 eV) in line with experimental findings but also show evidence of Li ion trapping on Al doping in LATP (where x = 0.4), possibly explaining the experimental observation that the Li ion conductivity does not improve above x = 0.3, due to a stronger repulsion between Li+–>Ti4+ compared to Li+–>Al3+. Furthermore, our calculated ionic conductivities are in excellent agreement with experimental values, highlighting the robustness of our computational models.

White Matter fMRI Activation Cannot Be Treated as a Nuisance Regressor: Overcoming a Historical Blind Spot

Despite past controversies, increasing evidence has led to acceptance that white matter activity is detectable using functional magnetic resonance imaging (fMRI). In spite of this, advanced analytic methods continue to be published that reinforce a historic bias against white matter activation by using it as a nuisance regressor. It is important that contemporary analyses overcome this blind spot in whole brain functional imaging, both to ensure that newly developed noise regression techniques are accurate, and to ensure that white matter, a vital and understudied part of the brain, is not ignored in functional neuroimaging studies.

Revisiting the Growth Mechanism of Hierarchical Semiconductor Nanostructures: The Role of Secondary Nucleation in Branch Formation.

Although there have been advances in synthesizing hierarchical semiconductor materials, few studies have investigated the fundamental nucleation mechanisms to explain the origins of such complex structures. Resolving these nucleation and growth pathways is technically challenging but critical for developing predictive synthetic capabilities for the synthesis and application of new materials. In this Letter, we use state-of-the-art in situ liquid phase scanning electron microscopy (SEM) and high-resolution transmission electron microscopy in a combination with classical density functional theory (cDFT) to study the nucleation of highly branched wurtzite ZnO nanostructures via a facile, room-temperature aqueous synthesis route. Using a range of precursor concentrations, we systematically vary the hierarchical organizationof these nanostructures. In situ liquid phase SEM demonstrates that all branches form through secondary nucleation and grow by classical processes. Neither random aggregation nor oriented attachment is observed. cDFT results imply that the morphological evolution with increasing [Zn2+] arises from an interplay between a rising thermodynamic driving force, which promotes branch number and variability of orientation, and increasing barriers to interfacial transport due to ion correlation forces that alter the anisotropic kinetics of growth. These findings provide a quantitative picture of branching that sets to rest past controversies and advances efforts to decipher growth mechanisms of hierarchical structures in real solution environments.

Now that They’re Out: Experiences of College Athletics Teams with Openly LGBTQ Players

ABSTRACT In recent years, more college athletes have publicly identified as lesbian, gay, bisexual, transgender, and/or queer (LGBTQ). Our study seeks to move past media celebrations and controversies of “coming out” and examine actual experiences of LGBTQ athletes and their teammates. A survey of 259 LGBTQ athletes and teammates of LGBTQ athletes was conducted. We examined concerns about being or playing with LGBTQ athletes, sources of homophobic language, experiences and observations of discrimination, and perceived impact of being or playing with an LGBTQ athlete. Findings indicate that many fears associated with college athletes coming out are likely overstated. All participants reported low levels of concern, homophobia, and negative impact of being or playing with an LGBTQ teammate. However, there were some differences between LGBTQ and non-LGBTQ athletes with non-LGBTQ athletes reporting fewer concerns, but also hearing less homophobic language than their LGBTQ counterparts. programs.

Kawasaki disease in 2019—past controversies, present insights and future directions: a narrative review

Kawasaki disease (KD) is a condition that is of interest to many pediatricians. Notwithstanding possible complications to coronary arteries, there is much that is yet unknown, including the controversies which surround this vasculitis. Making a timely and accurate diagnosis is essential for appropriate treatment, and incomplete KD adds a dimension to this complexity. While there are guidelines available for diagnosis, including clinical and echocardiographic findings, there is no definitive laboratory test, given the still unclear etiology. The best treatment option for recalcitrant disease is also debatable, as are the factors for those at high risk for coronary dilation. Although scoring systems are now available to risk stratify, these have variable success. It is envisaged that with the further development of novel biomarkers and genotyping, timely identification of those at risk will be a possibility. This article discusses evolution of our knowledge in KD over 5 decades, and reviews the advances which have been made.

Conditioned inhibition: Historical critiques and controversies in the light of recent advances.

Conditioned inhibition is a Pavlovian learning phenomenon in which a stimulus that predicts the absence of an otherwise expected outcome comes to control an organism's responding. Such responding usually manifests as a tendency that opposes that of a stimulus that predicts the outcome, also known as a conditioned excitor. Some learning theorists have expressed concerns about the validity and usefulness of conditioned inhibition as a concept; claims that may have negatively affected the reputation of this research area. This article offers a contemporary review of critiques of and controversies over conditioned inhibition and of arguments advanced in its defense. Some of these disputes have been reported in previous reviews, but here we have sought to compile the most representative among them. We also propose new arguments that answer some of those critiques. We then address the most prominent theoretical accounts of conditioned inhibition, identifying commonalities and differences among some of them. Finally, we review recent studies of conditioned inhibition. Some of the new findings contribute to rejecting early critiques of conditioned inhibition and others further elucidate the nature of this phenomenon. A new set of studies suggests that a deficit in conditioned inhibition characterizes some psychiatric conditions, illustrating its translational importance. We believe that new generations of researchers will benefit from being aware of past controversies and how they may have shaped the current conception of conditioned inhibition. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Identification of a unique Ca2+-binding site in rat acid-sensing ion channel 3

Acid-sensing ion channels (ASICs) evolved to sense changes in extracellular acidity with the divalent cation calcium (Ca2+) as an allosteric modulator and channel blocker. The channel-blocking activity is most apparent in ASIC3, as removing Ca2+ results in channel opening, with the site’s location remaining unresolved. Here we show that a ring of rat ASIC3 (rASIC3) glutamates (Glu435), located above the channel gate, modulates proton sensitivity and contributes to the formation of the elusive Ca2+ block site. Mutation of this residue to glycine, the equivalent residue in chicken ASIC1, diminished the rASIC3 Ca2+ block effect. Atomistic molecular dynamic simulations corroborate the involvement of this acidic residue in forming a high-affinity Ca2+ site atop the channel pore. Furthermore, the reported observations provide clarity for past controversies regarding ASIC channel gating. Our findings enhance understanding of ASIC gating mechanisms and provide structural and energetic insights into this unique calcium-binding site.

Distinct progression pattern of susceptibility MRI in the substantia nigra of Parkinson's patients.

Susceptibility MRI may capture Parkinson's disease-related pathology. This study delineated longitudinal changes in different substantia nigra regions. Seventy-two PD patients and 62 controls were studied at both baseline and after 18 months with MRI. R2* and quantitative susceptibility mapping values from the substantia nigra pars compacta and substantia nigra pars reticulata were calculated. Mixed-effects models compared controls with PD or PD subgroups having different disease durations: early (<1 year), middle (<5 years, middle-stage PD), and late (>5 years, late-stage PD). Pearson's correlation assessed associations between imaging and clinical measures. At baseline, R2* and quantitative susceptibility mapping were higher in both the substantia nigra pars compacta and substantia nigra pars reticulata in all PD patients (group effect, P ≤ 0.003). Longitudinally, the substantia nigra pars compacta R2* showed a faster increase in PD compared with controls (time × group, P = 0.002), whereas quantitative susceptibility mapping did not (P = 0.668). The substantia nigra pars reticulata R2* and quantitative susceptibility mapping did not differ between PD and controls (time × group, P ≥ 0.084), although both decreased longitudinally (time effect, P ≤ 0.004). Baseline substantia nigra pars compacta R2* was higher in all PD subgroups (group, P ≤ 0.006), but showed a significantly faster increase only in later-stage PD (time × group, P < 0.0001) that correlated with changes in nonmotor symptoms (r = 0.746, P = 0.002). Baseline substantia nigra pars reticulata quantitative susceptibility mapping was higher in middle-stage PD and later-stage PD (group, P ≤ 0.002), but showed a longitudinal decrease (time × group, P = 0.004) only in later-stage PD that correlated with changes in motor signs (r = 0.837, P < 0.001). Susceptibility MRI revealed distinct patterns of PD progression in the substantia nigra pars compacta and substantia nigra pars reticulata. The different patterns are particularly clear in later-stage patients. These findings may resolve past controversies and have implications in the pathophysiological processes during PD progression. © 2018 International Parkinson and Movement Disorder Society.

Surface currents associated with external kink modes in tokamak plasmas during a major disruption

The surface current on the plasma-vacuum interface during a disruption event involving kink instability can play an important role in driving current into the vacuum vessel. However, there have been disagreements over the nature or even the sign of the surface current in recent theoretical calculations based on idealized step-function background plasma profiles. We revisit such calculations by replacing step-function profiles with more realistic profiles characterized by strong but finite gradient along the radial direction. It is shown that the resulting surface current is no longer a delta-function current density, but a finite and smooth current density profile with internal structure, concentrated within the region with strong plasma pressure gradient. Moreover, this current density profile has peaks of both signs, unlike the delta-function case with a sign opposite to, or the same as the plasma current. We show analytically and numerically that such current density can be separated into two parts, with one of them, called the convective current density, describing the transport of the background plasma density by the displacement, and the other part that remains, called the residual current density. It is argued that consideration of both types of current density is important and can resolve past controversies.