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We propose a cluster-based control strategy for feedback control of post-stall separated flows over an airfoil. The present approach partitions the flow trajectories (force measurements) into clusters, which correspond to characteristic coarse-grained phases in a low-dimensional feature space. A feedback control law (using blowing/suction actuation) is then sought for each cluster state through iterative evaluation and downhill simplex search to minimize power consumption in aerodynamic flight. The optimized control laws re-route the flow trajectories to the aerodynamically favourable regions in the feature space in a model-free manner. Utilizing a limited number of sensor measurements for both clustering and optimization, these feedback laws were determined in only
iterations. The objective of the present work is not necessarily to suppress flow separation but to minimize the desired cost function to achieve enhanced aerodynamic performance. The present approach is applied to the control of two- and three-dimensional separated flows over a NACA 0012 airfoil in large-eddy simulations at an angle of attack of
, Reynolds number
and free-stream Mach number
. The optimized control laws avoid the intermittent occurrence of long-period shedding associated with high-drag clusters, thus lowering the mean drag. The present work aims to address some of the challenges associated with feedback control design for turbulent separated flows at moderate Reynolds number.
We present the first general metric for attractor overlap (MAO) facilitating an unsupervised comparison of flow data sets. The starting point is two or more attractors, i.e. ensembles of states representing different operating conditions. The proposed metric generalizes the standard Hilbert-space distance between two snapshot-to-snapshot ensembles of two attractors. A reduced-order analysis for big data and many attractors is enabled by coarse graining the snapshots into representative clusters with corresponding centroids and population probabilities. For a large number of attractors, MAO is augmented by proximity maps for the snapshots, the centroids and the attractors, giving scientifically interpretable visual access to the closeness of the states. The coherent structures belonging to the overlap and disjoint states between these attractors are distilled by a few representative centroids. We employ MAO for two quite different actuated flow configurations: a two-dimensional wake with vortices in a narrow frequency range and three-dimensional wall turbulence with a broadband spectrum. In the first application, seven control laws are applied to the fluidic pinball, i.e. the two-dimensional flow around three circular cylinders whose centres form an equilateral triangle pointing in the upstream direction. These seven operating conditions comprise unforced shedding, boat tailing, base bleed, high- and low-frequency forcing as well as two opposing Magnus effects. In the second example, MAO is applied to three-dimensional simulation data from an open-loop drag reduction study of a turbulent boundary layer. The actuation mechanisms of 38 spanwise travelling transversal surface waves are investigated. MAO compares and classifies these actuated flows in agreement with physical intuition. For instance, the first feature coordinate of the attractor proximity map correlates with drag for the fluidic pinball and for the turbulent boundary layer. MAO has a large spectrum of potential applications ranging from a quantitative comparison between numerical simulations and experimental particle-image velocimetry data to the analysis of simulations representing a myriad of different operating conditions.
The Boko Haram insurgency has brought turmoil and instability to Nigeria, generating a large number of internally displaced people and adding to the country's 17.5 million orphans and vulnerable children. Recently, steps have been taken to improve the mental healthcare infrastructure in Nigeria, including revamping national policies and initiating training of primary care providers in mental healthcare. In order for these efforts to succeed, they require means for community-based detection and linkage to care. A major gap preventing such efforts is the shortage of culturally appropriate, valid screening tools for identifying emotional and behavioral disorders among adolescents. In particular, studies have not conducted simultaneous validation of screening tools in multiple languages, to support screening and detection efforts in linguistically diverse populations. We aim to culturally adapt screening tools for emotional and behavioral disorders for use among adolescents in Nigeria, in order to facilitate future validation studies.
We used a rigorous mixed-method process to culturally adapt the Depression Self Rating Scale, Child PTSD Symptom Scale, and Disruptive Behavior Disorders Rating Scale. We employed expert translations, focus group discussions (N = 24), and piloting with cognitive interviewing (N = 24) to achieve semantic, content, technical, and criterion equivalence of screening tool items.
We identified and adapted items that were conceptually difficult for adolescents to understand, conceptually non-equivalent across languages, considered unacceptable to discuss, or stigmatizing. Findings regarding problematic items largely align with existing literature regarding cross-cultural adaptation.
Culturally adapting screening tools represents a vital first step toward improving community case detection.
Perceived discrimination (PD) is reliably and strongly associated with partisan identity (PID) among US immigrant minorities such as Latinos and Asian Americans. Yet whether PD causes PID remains unclear, since it is possible that partisanship influences perceptions of discrimination or that other factors drive the observed association. Here, we assess the causal influence of group-level PD on PID using five experiments with Latino and Asian American adults. These experiments varied in important ways: they took place inside and outside the lab, occurred prior to and during Donald Trump’s presidential campaign, and tested different manifestations of PD and partisan attitudes (total n = 2,528). These efforts point to a simple but unexpected conclusion: our experiments and operationalizations do not support the claim that group-targeted PD directly causes PID. These results have important implications for understanding partisanship among immigrants and their co-ethnics and the political incorporation of Latinos and Asian Americans.
Psychiatric diagnostic manuals recognise the importance of local expressions of distress in culturally diverse settings [i.e. idioms/cultural concepts of distress (CCDs)], yet there is a lack of consensus on how these should be incorporated into mental health related research.
To perform a narrative synthesis and critical review of research exploring how idioms/CCDs have been integrated into assessment measures and interventions.
A systematic review was conducted in accordance with PRISMA guidelines. An adapted version of the COSMIN checklist was used to assess the quality of the linguistic translation of the idioms/CCDs.
Twenty-nine papers were included in the final review. Primary qualitative research was the most common method of gathering information about idioms/CCDs. The majority of studies described integrating idioms/CCDs into assessment measures as opposed to interventions. Some studies used information relating to idioms/CCDs to develop novel assessment measures, while others adapted pre-existing assessment measures. The measures generated moderate to high levels of validity. Information relating to the linguistic translation conducted in the completion of the studies tended to be inadequately reported.
Integrating information about idioms/CCDs into assessment measures can enhance the validity of these assessments. Allocating greater research attention to idioms/CCDs can also promote more equitable exchanges of knowledge about mental health and wellbeing between the Global North and the Global South.
Localized network processes are central to the study of political science, whether in the formation of political coalitions and voting blocs, balancing and bandwagoning, policy learning, imitation, diffusion, tipping-point dynamics, or cascade effects. These types of processes are not easily modeled using traditional network approaches, which focus on global rather than local structures within networks. We show that localized network processes, in which network edges form in response to the formation of other edges, are best modeled by shifting from the traditional theoretical framework of nodes-as-actors to what we term a nodes-as-actions framework, which allows for zeroing in on relationships among network connections. We show that the proposed theoretical framework is statistically compatible with a local structure graph model (LSGM). We demonstrate the properties of LSGMs using a Monte Carlo experiment and explore action–reaction processes in two empirical applications: formation of alliances among countries and legislative cosponsorships in the US Senate.
Premenstrual dysphoric disorder (PMDD) is a new Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 diagnosis characterized by the cyclical emergence of emotional and physical symptoms in the luteal phase of the menstrual cycle, with symptom remission in the follicular phase. Converging evidence highlights the possibility of distinct subtypes of PMDD with unique pathophysiologies, but temporal subgroups have yet to be explored in a systematic way.
In the current work, we use group-based trajectory modeling to identify unique trajectory subgroups of core emotional and total PMDD symptoms across the perimenstrual frame (days −14 to +9, where day 0 is menstrual onset) in a sample of 74 individuals prospectively diagnosed with DSM-5 PMDD.
For the total daily symptom score, the best-fitting model was comprised of three groups: a group demonstrating moderate symptoms only in the premenstrual week (65%), a group demonstrating severe symptoms across the full 2 weeks of the luteal phase (17.5%), and a group demonstrating severe symptoms in the premenstrual week that were slow to resolve in the follicular phase (17.5%).
These trajectory groups are discussed in the context of the latest work on the pathophysiology of PMDD. Experimental work is needed to test for the presence of possible pathophysiologic differences in trajectory groups, and whether unique treatment approaches are needed.
Bipolar disorder I (BD-I) is defined by episodes of mania, depression and euthymic states. These episodes are among other symptoms characterized by altered reward processing and negative symptoms (NS), in particular apathy. However, the neural correlates of these deficits are not well understood.
We first assessed the severity of NS in 25 euthymic BD-I patients compared with 25 healthy controls (HC) and 27 patients with schizophrenia (SZ). Then, we investigated ventral (VS) and dorsal striatal (DS) activation during reward anticipation in a Monetary Incentive Delayed Task and its association with NS.
In BD-I patients NS were clearly present and the severity of apathy was comparable to SZ patients. Apathy scores in the BD-I group but not in the SZ group correlated with sub-syndromal depression scores. At the neural level, we found significant VS and DS activation in BD-I patients and no group differences with HC or SZ patients. In contrast to patients with SZ, apathy did not correlate with striatal activation during reward anticipation. Explorative whole-brain analyses revealed reduced extra-striatal activation in BD-I patients compared with HC and an association between reduced activation of the inferior frontal gyrus and apathy.
This study found that in BD-I patients apathy is present to an extent comparable to SZ, but is more strongly related to sub-syndromal depressive symptoms. The findings support the view of different pathophysiological mechanisms underlying apathy in the two disorders and suggest that extra-striatal dysfunction may contribute to impaired reward processing and apathy in BD-I.
New therapeutic strategies have been established in chronic wound healing procedures, such as the use of platelet-rich plasma (PRP). There is currently still uncertainty about the effectiveness, cost-effectiveness and real safety of PRP in promoting chronic wound healing and what specific types of chronic wounds can benefit most from its use.
We conducted a systematic review of available scientific literature on the effectiveness, safety and cost-effectiveness of PRP compared to placebo, standard care or alternative topical therapies for the treatment of chronic wounds in adults. Overall effect size was estimated through a meta-analysis. A cost-effectiveness analysis was conducted using a Markov model which simulates the costs and health outcomes of individuals for a 5-year horizon, from the perspective of the Spanish National Health Service (NHS) for the PRP versus standard treatment in patients with diabetic foot ulcers. The effectiveness measure was quality-adjusted life years (QALYs). We ran extensive sensitivity analyses, including a probabilistic sensitivity analysis.
Sixteen RCTs and four observational studies were included for the effectiveness and safety meta-analysis. The primary outcome was the proportion of chronic wounds completely healed: 143 patients out of 334 (42.8 percent) were cured in the standard treatment arm and 251 patients out of 375 (66.9 percent) in the PRP arm, relative risk (RR) 1.68 (95% CI: 1.22–2.31). It was unclear whether there was a difference in the risk of infection (RR 0.53, 95% CI: 0.10–2.71) or adverse events (RR 1.05, 95% CI: 0.29–3.88) between PRP and standard care. Three studies were considered for the cost-effectiveness analysis. In the base case analysis, PRP led to higher QALYs and healthcare costs with an estimated incremental cost-effectiveness ratio (ICER) of EUR 41,767 (USD 48,323)/QALY.
PRP treatment is more expensive and more effective than standard treatment. The estimated ICER is above the acceptability threshold in Spain.
This article investigates the involvement of the penal state in the lives of criminalized people as a controlling force that takes multiple forms. We offer the concept of modalities of penal control and identify three such modalities in addition to expressive punishment: interventionist penal control is accomplished in extralegal ways; covert penal control is hidden from public view; and negligent penal control is characterized by the absence of action by state actors. This article illustrates empirical cases of each modality, using data from three distinct projects based in Chicago, southern Wisconsin, and nationwide. The data include observations of post-prison groups and homes, interviews with criminalized people and nongovernmental organizational (NGO) staff, statutes, and regulations. This expanded understanding of penal state involvement extends beyond the understanding that characterizes discussions of mass incarceration and highlights the need for comprehensive reform.
This article reviews social psychological theory and empirical research on perceiving and reporting discrimination. The article begins with an examination of factors that affect whether individuals perceive themselves as targets of discrimination. We then turn toward addressing whether individuals who perceive discrimination are willing to report their perceptions, as well as the interpersonal consequences they might face for so doing. Throughout this article, we examine how endorsement of the meritocratic worldview shapes these discrimination-related processes. Finally, we conclude by noting the potential for important theoretical, empirical, and applied advances on discrimination scholarship that can arise from interdisciplinary collaboration among legal scholars and social scientists.
In their focal article, Reynolds, McCauley, Tsacoumis, and the Jeanneret Symposium Participants (2018) stress the importance of context in leadership assessment. For instance, they argue that senior executives work in a different context compared to lower-level managers and that this should be taken into account. A simple example is that the competency of strategic thinking is critical for executive performance but much less so, if at all, for front-line supervisors. The claim that context matters in leadership and in the assessment of leaders is easy to grasp but difficult to apply in practice.
No one seems yet to have appreciated that what is the earliest Latin verse of the New World is also its earliest extant verse by any visitor from the Old World. Furthermore, no one has paid any attention to the very poems themselves.
The poet was Alessandro Geraldini (ca. 1455-1524), Italian humanist, diplomat, and churchman. A native of Umbria, Geraldini went to school in Italy, but later left for Spain with his older brother, Antonio, the two bringing with them, like their famous contemporaries Peter Martyr and Marineus Siculus, the influence of the new learning of the Renaissance. At the age of twenty-one, Alessandro served under Ferdinand and Isabella as the Castilians defeated the Portuguese at Toro. He became cupbearer to Isabella, and traveled with Antonio, when the latter was secretary to John II of Aragon, on visits to Francis II, Duke of Brittany, and to Edward IV of England.