This paper discusses alternative measures of assortative matching and relates them to Sewall Wright’s F-statistic. It also explores applications of measures of assortativity to evolutionary dynamics. We generalize Wright’s statistic to allow the possibility that some types match more assortatively than others, and explore the possibility of identifying parameters of this more general model from the observed distribution of matches by the partners’ types.

Surgical expertise does not have a clear definition and is often culturally associated with power, authority, prestige, and case number rather than more objective proxies of excellence. Multiple models of expertise progression have been proposed including the Dreyfus model, however, they all currently require subjective evaluation of skill. Recently, efforts have been made to improve the ways in which surgical excellence is measured and expertise is defined using artificial intelligence, video recordings, and accelerometers. However, these aforementioned methods of assessment are (...) still subjective or indirect proxies of expertise, thus uncovering the neural mechanisms that differentiate expert surgeons from trainees may enhance the objectivity of surgical expertise validation. In fact, some researchers have already suggested that their neural imaging-based expertise classification methods outperform currently used methods of surgical skill certification such as the Fundamentals of Laparoscopic Surgery scores. Such imaging biomarkers would not only help better identify the highest performing surgeons, but could also improve residency programs by providing more objective, evidence-based feedback and developmental milestones for those in training and perhaps act as a marker of surgical potential in medical students. Despite the potential advantages of using neural imaging in the assessment of surgical expertise, this field of research remains in its infancy. This systematic review identifies studies that have applied neuromonitoring in assessing surgical skill across levels of expertise. The goals of this review are to identify the strongest neural indicators of surgical expertise, the limitations of the current literature on this subject, the most sensible future directions for further study. We found substantial evidence that surgical expertise can be delineated by differential activation and connectivity in the prefrontal cortex across multiple task and neuroimaging modalities. Specifically, novices tend to have greater PFC activation than experts under standard conditions in bimanual and decision-making tasks. However, under high temporal demand tasks, experts had increased PFC activation whereas novices had decreased PFC activation. Common limitations uncovered in this review were that task difficulty was often insufficient to delineate between residents and attending. Moreover, attending level involvement was also low in multiple studies which may also have contributed to this issue. Most studies did not analyze the ability of their neuromonitoring findings to accurately classify subjects by level of expertise. Finally, the predominance of fNIRS as the neuromonitoring modality limits our ability to uncover the neural correlates of surgical expertise in non-cortical brain regions. Future studies should first strive to address these limitations. In the longer term, longitudinal within-subjects design over the course of a residency or even a career will also advance the field. Although logistically arduous, such studies would likely be most beneficial in demonstrating effects of increasing surgical expertise on regional brain activation and inter-region connectivity. (shrink)

Multitasking is a critical feature of our daily lives. Using a dual-task paradigm, this experiment explored adults’ abilities to simultaneously engage in everyday motor and cognitive activities, counting while walking, under conditions varying the difficulty of each of these tasks. Motor difficulty was manipulated by having participants walk forward versus backward, and cognitive difficulty was manipulated by having participants count forward versus backward, employing either a serial 2 s or serial 3 s task. All of these manipulations were performed in (...) single-task conditions and dual-task conditions. Both motor performance variables and cognitive variables were assessed in these conditions. Analyses of single-task conditions revealed that both motor and cognitive manipulations predictably influenced performance. Analyses of dual-task performance revealed influences of motor and cognitive factors on both motor and cognitive performance. Most centrally, dual-task costs for motor variables revealed that such costs occurred primarily for temporal or spatiotemporal gait parameters and were driven by cognitive manipulations. Dual-task cost analyses for cognitive measures revealed negative dual-task costs, or dual-task benefits, for cognitive performance. Finally, the effects of dual-task manipulations were correlated for motor and cognitive measures, indicating dual-task performance as a significant individual difference variable. These findings are discussed with reference to theories of attentional allocation, as well as the possible role of auditory–motor entrainment in dual-task conditions. (shrink)

When labeling an infectious disease, officially sanctioned scientific names, e.g., “H1N1 virus,” are recommended over place-specific names, e.g., “Spanish flu.” This is due to concerns from policymakers and the WHO that the latter might lead to unintended stigmatization. However, with little empirical support for such negative consequences, authorities might be focusing on limited resources on an overstated issue. This paper empirically investigates the impact of naming against the current backdrop of the 2019–2020 pandemic. The first hypothesis posited that using place-specific (...) names associated with China leads to greater levels of sinophobia, the negative stigmatization of Chinese individuals. The second hypothesis posited that using a scientific name leads to increased anxiety, risk aversion, beliefs about contagiousness of the virus, and beliefs about mortality rate. Results from two preregistered studies [N = 504; N = 412], conducted across three countries with the first study during the early outbreak and the second study at a later stage of the pandemic, found no evidence of any adverse effects of naming on sinophobia and strong support for the null hypothesis using Bayesian analyses. Moreover, analyses found no impact of naming on anxiety, risk aversion, beliefs about contagiousness of the virus, or beliefs about mortality rate, with mild to strong support for the null hypothesis across outcomes. Exploratory analyses also found no evidence for the effect of naming being moderated by political affiliation. In conclusion, results provide no evidence that virus naming impacted individual’s attitudes toward Chinese individuals or perceptions of the virus, with the majority of analyses finding strong support for the null hypothesis. Therefore, based on the current evidence, it appears that the importance given to naming infectious diseases might be inflated. (shrink)

Creating android and humanoid robots to furnish companionship in the nursing care of older people continues to attract substantial development capital and research. Some people object, though, that machines of this kind furnish human–robot interaction characterized by inauthentic relationships. In particular, robotic and artificial intelligence (AI) technologies have been charged with substituting mindless mimicry of human behaviour for the real presence of conscious caring offered by human nurses. When thus viewed as deceptive, the robots also have prompted corresponding concerns regarding (...) their potential psychological, moral, and spiritual implications for people who will be interacting socially with these machines. The foregoing objections and concerns can be assessed quite differently, depending upon ambient religious beliefs or metaphysical presuppositions. The complaints may be set aside as unnecessary, for example, within religious traditions for which even current robots can be viewed as presenting spiritual aspects. Elsewhere, technological cultures may reject the complaints as expression of outdated superstition, holding that the machines eventually will enjoy a consciousness described entirely in materialist and behaviourist terms. While recognizing such assessments, the authors of this essay propose that the heart of the foregoing objections and concerns may be evaluated, in part, scientifically – albeit with a conclusion recommending fundamental revisions in AI modelling of human mental life. Specifically, considerations now favour introduction of AI models using interactive classical and quantum computation. Without this change, the answer to the essay's title question arguably is ‘no’ – with it, the answer plausibly becomes ‘maybe’. Either outcome holds very interesting implications for nurses. (shrink)

U.S. researchers and scholars often point to two legal factors as significant obstacles to the inclusion of pregnant women in clinical research: the Department of Health and Human Services’ regulatory limitations specific to pregnant women's research participation and the fear of liability for potential harm to children born following a pregnant woman's research participation. This article offers a more nuanced view of the potential legal complexities that can impede research with pregnant women than has previously been reflected in the literature. (...) It reveals new insights into the role of legal professionals throughout the research pathway, from product conception to market, and it highlights a variety of legal factors influencing decision-making that may slow or halt research involving pregnant women. Our conclusion is that closing the evidence gap created by the underrepresentation and exclusion of pregnant women in research will require targeted attention to the role of legal professionals and the legal factors that influence their decisions. (shrink)

We show that the Π 0 2 enumeration degrees are not dense. This answers a question posed by Cooper.

Plasminogen activator inhibitor‐1 (PAI‐1) is a physiological inhibitor of urokinase (uPA), a serine protease known to promote cell migration and invasion. Intuitively, increased levels of PAI‐1 should be beneficial in downregulating uPA activity, particularly in cancer. By contrast, in vivo, increased levels of PAI‐1 are associated with a poor prognosis in breast cancer. This phenomenon is termed the “PAI‐1 paradox”. Many factors are responsible for the upregulation of PAI‐1 in the tumor microenvironment. We hypothesize that there is a breast cancer (...) predisposition to a more aggressive stage when PAI‐1 is upregulated as a consequence of Metabolic Syndrome (MetS). MetS exerts a detrimental effect on the breast tumor microenvironment that supports cancer invasion. People with MetS have an increased risk of coronary heart disease, stroke, peripheral vascular disease and hyperinsulinemia. Recently, MetS has also been identified as a risk factor for breast cancer. We hypothesize the existence of the “PAI‐1 cycle”. Sustained by MetS, adipocytokines alter PAI‐1 expression to promote angiogenesis, tumor‐cell migration and procoagulant microparticle formation from endothelial cells, which generates thrombin and further propagates PAI‐1 synthesis. All of these factors culminate in a chemotherapy‐resistant breast tumor microenvironment. The PAI‐1 cycle may partly explain the PAI‐1 paradox. In this hypothesis paper, we will discuss further how MetS upregulates PAI‐1 and how an increased level of PAI‐1 can be linked to a poor prognosis. BioEssays 29:1029–1038, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Stephanie Morain and Emily Largent’s (2023) target article “Think Pragmatically: Investigators’ Obligations to Patient-Subjects When Research is Embedded in Care” identified a number of important c...

Si l’âge compte dans les rencontres amoureuses, les femmes et les hommes ne le comptent pas de la même manière. C’est ce que montrent les usages des sites de rencontres sur Internet. La manière dont les utilisateurs s’approprient ces services – par la présentation de soi et la description des critères amoureux – révèle les significations différentes qu’accordent les deux sexes à leur âge comme à celui du partenaire. En prenant pour objet ces attitudes sexuées, l’article éclaire la place de (...) l’âge dans la formation des couples mais souligne aussi l’inégalité des femmes et des hommes face à la conjugalité. (shrink)