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Three-dimensional effects of sidewalls on the low-frequency unsteadiness of the shock-wave/boundary-layer interaction (SBLI) are of academic and practical importance but not yet well understood. Considerable attention has been paid to the viscous effect of sidewalls, whereas the potential inviscid confinement effect of sidewalls has received little attention. The present work provides experimental evidence of multiscale spanwise travelling waves crossing the separation front under the confinement of sidewalls. Global pressure measurements were made for a sidewall-confined 24$^\circ$ compression ramp interaction in Mach-2.83 flow using fast-responding pressure-sensitive paint. The unsteady pressure in a statistically two-dimensional intermittent region suggests that in addition to the canonical streamwise oscillation, the separation front exhibits significant low-frequency, multiscale spanwise distortion. Modal analysis further reveals that multiscale spanwise unsteadiness has higher intensity and frequency than the streamwise oscillation. Such strong spanwise unsteadiness calls attention to the low-frequency unsteadiness in previous sidewall-confined SBLI experiments and encourages further study on the mechanism of the confinement effect.
This study investigates the impact of molecular thermal fluctuations on compressible decaying isotropic turbulence using the unified stochastic particle (USP) method, encompassing both two-dimensional (2-D) and three-dimensional (3-D) scenarios. The findings reveal that the turbulent spectra of velocity and thermodynamic variables follow the wavenumber (k) scaling law of ${k}^{(d-1)}$ for different spatial dimensions $d$ within the high wavenumber range, indicating the impact of thermal fluctuations on small-scale turbulent statistics. With the application of Helmholtz decomposition, it is found that the thermal fluctuation spectra of solenoidal and compressible velocity components (${\boldsymbol {u}}_{s}$ and ${\boldsymbol {u}}_{c}$) follow an energy ratio of 1 : 1 for 2-D cases, while the ratio changes to 2 : 1 for 3-D cases. Comparisons between 3-D turbulent spectra obtained through USP simulations and direct numerical simulations of the Navier–Stokes equations demonstrate that thermal fluctuations dominate the spectra at length scales comparable to the Kolmogorov length scale. Additionally, the effect of thermal fluctuations on the spectrum of ${\boldsymbol {u}}_{c}$ is significantly influenced by variations in the turbulent Mach number. We further study the impact of thermal fluctuations on the predictability of turbulence. With initial differences caused by thermal fluctuations, different flow realizations display significant disparities in velocity and thermodynamic fields at larger scales after a certain period of time, which can be characterized by ‘inverse error cascades’. Moreover, the results suggest a strong correlation between the predictabilities of thermodynamic fields and the predictability of ${\boldsymbol {u}}_{c}$.
Spatial autoregressive (SAR) and related models offer flexible yet parsimonious ways to model spatial and network interactions. SAR specifications typically rely on a particular parametric functional form and an exogenous choice of the so-called spatial weight matrix with only limited guidance from theory in making these specifications. Also, the choice of a SAR model over other alternatives, such as spatial Durbin (SD) or spatial lagged X (SLX) models, is often arbitrary, raising issues of potential specification error. To address such issues, this paper develops a new specification test within the SAR framework that can detect general forms of misspecification including that of the spatial weight matrix, the functional form and the model itself. The test is robust to the presence of heteroskedasticity of unknown form in the disturbances and the approach relates to the conditional moment test framework of Bierens ([1982, Journal of Econometrics 20, 105–134], [1990, Econometrica 58, 1443–1458]). The Bierens test is shown to be inconsistent in general against spatial alternatives and the new test introduces modifications to achieve test consistency in the spatial setting. A central element is the infinite-dimensional endogeneity induced by spatial linkages. This complexity is addressed by introducing a new component to the omnibus test that captures the effects of potential spatial matrix misspecification. With this modification, the approach leads to a simple pivotal test procedure with standard critical values that is the first test in the literature to have power against misspecifications in the spatial linkages. We derive the asymptotic distribution of the test under the null hypothesis of correct SAR specification and prove consistency. A Monte Carlo study is conducted to study its finite sample performance. An empirical illustration on the performance of the test in modeling tax competition in Finland is included.
This commentary discusses opportunities for advancing the field of developmental psychopathology through the integration of data science and neuroscience approaches. We first review elements of our research program investigating how early life adversity shapes neurodevelopment and may convey risk for psychopathology. We then illustrate three ways that data science techniques (e.g., machine learning) can support developmental psychopathology research, such as by distinguishing between common and diverse developmental outcomes after stress exposure. Finally, we discuss logistical and conceptual refinements that may aid the field moving forward. Throughout the piece, we underscore the profound impact of Dr Dante Cicchetti, reflecting on how his work influenced our own, and gave rise to the field of developmental psychopathology.
We evaluated sampling and detection methods for fungal contamination on healthcare surface materials, comparing the efficacy of foam sponges, flocked swabs, and Replicate Organism Detection And Counting (RODAC) plates alongside culture-based quantification and quantitative polymerase chain reaction (qPCR). Findings indicate that sponge sampling and qPCR detection performed best, suggesting a foundation for future studies aiming to surveillance practices for fungi.
We are the first to study how the resources freed up when a child, child-in-law, or grandchild moves out of a household are reallocated, taking into account the age of the leaver. Using the 2011 and 2013 waves of the China Health and Retirement Longitudinal Study, we document that, on average, the remaining household members save part of the resources freed up by the leaver and consume another part. Differentiating the leavers by age, we find that after the departure of a member of the younger generation aged 0–24, the remaining household members save the resources freed up by the leaver. However, if the leaver is above 24, they spend the freed-up resources. Our results are robust to the use of different specifications, estimation methods, and consumption aggregates. Finally, we observe that remittances directed toward non-resident offspring do not increase after the departure of a member of the younger generation.
Cancer patients are among the most vulnerable populations during and after a disaster. We evaluated the impact of treatment interruption on the survival of women with gynecologic cancer in Puerto Rico following Hurricanes Irma and María.
Methods:
A retrospective cohort study among a clinic-based sample of women with gynecological cancer diagnosed between January 2016 and September 2017 (n = 112) was done. Women were followed from their diagnosis until December 2019, to assess vital status. Kaplan-Meier survival curves and Cox proportional hazards models were performed.
Results:
Mean age was 56 (± 12.3) years; corpus uteri (58.9%) was the most common gynecologic cancer. Predominant treatments were surgery (91.1%) and chemotherapy (44.6%). Overall, 75.9% were receiving treatment before the hurricanes, 16.1% experienced treatment interruptions, and 8.9% died during the follow-up period. Factors associated with treatment interruption in bivariate analysis included younger age (≤55 years), having regional/distant disease, and receiving > 1 cancer treatment (P < 0.05). Crude analysis revealed an increased risk of death among women with treatment interruption (HR: 3.88, 95% CI: 1.09-13.77), persisting after adjusting for age and cancer stage (HR: 2.49, 95% CI: 0.69-9.01).
Conclusions:
Findings underscore the detrimental impact of treatment interruption on cancer survival in the aftermath of hurricanes, emphasizing the need for emergency response plans for this vulnerable population.
Academic conferences are important institutions for promoting new research and facilitating conversations about the field. As a venue for knowledge exchange, professional development, and networking, conferences ideally promote positive environments that make scholars from underrepresented groups feel welcome. Yet, negative experiences at conferences are well documented. Codes of conduct have been promoted as tools to reduce harassment and discrimination. This article examines the prevalence and content of codes at US-based political science conferences and workshops. More specifically, we analyze whether and how codes address issues of sexual misconduct and identity-based discrimination. We find that 19% of 177 surveyed conferences have a code of conduct. Conferences that are older and larger are more likely to have codes, as are conferences that are run by organizations with permanent staff and relevant committees. We argue that effective conference codes must contain definitions, reporting channels, and enforcement procedures. Many of the analyzed codes did not explicitly define prohibited behaviors, specify mechanisms to report code violations, or describe consequences for misconduct.
“Multidimensional” accounts of autonomy offer multiple, rather than unitary, dimensions along which to measure autonomy. Such accounts are significant developments in the literature and help generate nuanced, degree-based frameworks. However, transnational feminists—those theorizing feminism in light of (post)colonialism and global neoliberalism—may raise concerns about multidimensional accounts for women in the Global South. For instance, there may be worries about the generalized focus and implicit individualism that still lurks. Sympathetic to both non-unitary autonomy and transnational feminist projects, I argue that multidimensional accounts can be salvaged from such critiques with two amendments. First, they can adopt what I label a “critical” relational framing, and second, they can include intersectional identities. Using commercial surrogates in India as an example, I show how these amendments to multidimensional theories might better serve these women of color, and indeed all persons.
The American craft beer industry’s creation narrative is rooted in countercultural food politics. Popular stories describe how plucky brewers pioneered complex and hoppy beers that revolutionized a bland American beer industry dominated by industrial lagers. Hops are now the most celebrated ingredient in the craft beer industry and serve as visual representations of the artisanal and revolutionary values of small brewers that contrasts with the industrial and bland products of the nation’s massive lager brewers. The history of hops and brewing presented here, however, demonstrates the connections between big and small brewers and the environmental impacts of craft brewers’ hoppy beers otherwise obscured by their preferred dichotomous narrative. Craft beer grew in tandem with the modern hop industry and became enmeshed with big business and industrial agricultural practices to access their signature commodity, hops. By integrating environmental and business history, this article explores how brewers, scientists, farmers, and nonhumans influenced each other to create the modern craft brewing industry. This approach demonstrates the often-obscured connections between big and small firms by examining the environments, organisms, and supply chains they depend upon.
The Industrial Removal Office funded 39,000 Jewish households to leave enclave neighborhoods in New York City from 1900 to 1922. Compared to neighbors with the same baseline occupation, program participants earned 4 percent more ten years after relocation. These gains persisted to the next generation. Benefits increased with more years spent outside of an enclave. Participants were more likely to speak English, and married spouses with less Jewish names. More Jewishly-identified men (as measured by own names) were more likely to return to the city. We contextualize these results with new national evidence on Jewish economic and cultural assimilation.
The ability of streamwise-travelling waves of spanwise velocity to reduce the turbulent skin-friction drag is assessed in the compressible regime. Direct numerical simulations are carried out to compare drag reduction in subsonic, transonic and supersonic channel flows. Compressibility improves the benefits of the travelling waves, in a way that depends on the control parameters: drag reduction becomes larger than the incompressible one for small frequencies and wavenumbers. However, the improvement depends on the specific procedure employed for comparison. When the Mach number is varied and, at the same time, wall friction is changed by the control, the bulk temperature in the flow can either evolve freely in time until the aerodynamic heating balances the heat flux at the walls, or be constrained such that a fixed percentage of kinetic energy is transformed into thermal energy. Physical arguments suggest that, in the present context, the latter approach should be preferred. This provides a test condition in which the wall-normal temperature profile more realistically mimics that in an external flow, and also leads to a much better scaling of the results, over both the Mach number and the control parameters. Under this comparison, drag reduction is only marginally improved by compressibility.
Understanding characteristics of healthcare personnel (HCP) with SARS-CoV-2 infection supports the development and prioritization of interventions to protect this important workforce. We report detailed characteristics of HCP who tested positive for SARS-CoV-2 from April 20, 2020 through December 31, 2021.
Methods:
CDC collaborated with Emerging Infections Program sites in 10 states to interview HCP with SARS-CoV-2 infection (case-HCP) about their demographics, underlying medical conditions, healthcare roles, exposures, personal protective equipment (PPE) use, and COVID-19 vaccination status. We grouped case-HCP by healthcare role. To describe residential social vulnerability, we merged geocoded HCP residential addresses with CDC/ATSDR Social Vulnerability Index (SVI) values at the census tract level. We defined highest and lowest SVI quartiles as high and low social vulnerability, respectively.
Results:
Our analysis included 7,531 case-HCP. Most case-HCP with roles as certified nursing assistant (CNA) (444, 61.3%), medical assistant (252, 65.3%), or home healthcare worker (HHW) (225, 59.5%) reported their race and ethnicity as either non-Hispanic Black or Hispanic. More than one third of HHWs (166, 45.2%), CNAs (283, 41.7%), and medical assistants (138, 37.9%) reported a residential address in the high social vulnerability category. The proportion of case-HCP who reported using recommended PPE at all times when caring for patients with COVID-19 was lowest among HHWs compared with other roles.
Conclusions:
To mitigate SARS-CoV-2 infection risk in healthcare settings, infection prevention, and control interventions should be specific to HCP roles and educational backgrounds. Additional interventions are needed to address high social vulnerability among HHWs, CNAs, and medical assistants.
Understanding the movement ecology of threatened species is fundamental to improving management and conservation actions for their protection, mainly during the pre-adult stage and particularly when a species is subject to population reinforcement or reintroduction projects. An example is the case of the Cinereous Vulture Aegypius monachus on the Iberian Peninsula, an endangered species that has been reintroduced in different regions during the last two decades. Here, we explore differences between the spatial ecology of reintroduced pre-adult Cinereous Vultures, according to age-class, sex, and season (breeding and non-breeding). We used GPS-tag data from 51 pre-adult individuals reintroduced into Catalonia (north-east Spain) to describe their use of space, i.e. home-range size, core area, and minimum convex polygon (MCP) and movement patterns, i.e. cumulative distance, maximum displacement, maximum daily dispersal, and maximum annual dispersal. Our study showed significant variation in the use of space and movement patterns among pre-adult birds and the influences of age, sex, and season. Age was the most influential factor, determining range areas and movement patterns. Similar to other vulture species, home range and core areas increase with age, with subadult vultures exhibiting larger ranges than young first year, juveniles, and immature birds, but the MCP measures were larger for juveniles. Movement patterns were also influenced by age-class, with juveniles making longer movements, followed by immatures and subadults (with similar values), and shorter movements for birds during their first year of life. Overall, males made shorter movements and explored smaller foraging areas than females. Season had an important effect on movement patterns, and the daily and dispersal movements were longer during the breeding period (February–August). Our findings fill a knowledge gap regarding the dispersal behaviours of Cinereous Vultures, information that will enable the improvement of management and conservation decisions.