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In this article, we give explicit bounds on the Wasserstein and Kolmogorov distances between random variables lying in the first chaos of the Poisson space and the standard normal distribution, using the results of Last et al. (Prob. Theory Relat. Fields165, 2016). Relying on the theory developed by Saulis and Statulevicius in Limit Theorems for Large Deviations (Kluwer, 1991) and on a fine control of the cumulants of the first chaoses, we also derive moderate deviation principles, Bernstein-type concentration inequalities, and normal approximation bounds with Cramér correction terms for the same variables. The aforementioned results are then applied to Poisson shot noise processes and, in particular, to the generalized compound Hawkes point processes (a class of stochastic models, introduced in this paper, which generalizes classical Hawkes processes). This extends the recent results of Hillairet et al. (ALEA19, 2022) and Khabou et al. (J. Theoret. Prob.37, 2024) regarding the normal approximation and those of Zhu (Statist. Prob. Lett.83, 2013) for moderate deviations.
Expert drivers possess the ability to execute high sideslip angle maneuvers, commonly known as drifting, during racing to navigate sharp corners and execute rapid turns. However, existing model-based controllers encounter challenges in handling the highly nonlinear dynamics associated with drifting along general paths. While reinforcement learning-based methods alleviate the reliance on explicit vehicle models, training a policy directly for autonomous drifting remains difficult due to multiple objectives. In this paper, we propose a control framework for autonomous drifting in the general case, based on curriculum reinforcement learning. The framework empowers the vehicle to follow paths with varying curvature at high speeds, while executing drifting maneuvers during sharp corners. Specifically, we consider the vehicle’s dynamics to decompose the overall task and employ curriculum learning to break down the training process into three stages of increasing complexity. Additionally, to enhance the generalization ability of the learned policies, we introduce randomization into sensor observation noise, actuator action noise, and physical parameters. The proposed framework is validated using the CARLA simulator, encompassing various vehicle types and parameters. Experimental results demonstrate the effectiveness and efficiency of our framework in achieving autonomous drifting along general paths. The code is available at https://github.com/BIT-KaiYu/drifting.
Advances in surgical and perioperative care have reduced the need for prolonged mechanical ventilation in children following cardiac surgery.
Aim of the study:
To evaluate the feasibility and assess the clinical outcomes of an early extubation strategy in the operating room for children undergoing congenital heart surgery, including neonates (age < 28 days).
Methods:
This is a retrospective analysis including congenital open-heart surgery cases. We excluded patients who remained open chest postoperatively or patients with severe hemodynamic instability and high inotropic support from the study. Study variables include age, gender, weight, preoperative cardiac diagnosis, preoperative diagnosis of genetic or chromosomal abnormalities, prematurity, preoperative mechanical ventilation (invasive or non-invasive), cardiopulmonary bypass time, circulatory arrest time, postoperative use of inotropes, duration of mechanical ventilation, postoperative respiratory complication, sepsis, bleeding or other complications, paediatric cardiac ICU stay, total hospital stay, incidence of failed extubation, and operative or postoperative mortality.
Results:
This study included 163 patients who underwent congenital open cardiac surgery, out of these studied patients, 118 (72.4%) were extubated in the operating room. In total, 19.6% of studied patients had Down syndrome. Other genetic or chromosomal disorders were present among 8.6% of studied patients. There was a statistically significant difference between operating room extubation group and non-operating room extubation group regarding Risk Adjustment for Congenital Heart Surgery Score classification, postoperative paediatric ICU duration, postoperative hospital length of stay, vasoactive-inotrope score, duration of inotrope, open chest, and mortality.
Conclusion:
Extubation in the operating room after congenital open-heart surgery was successful in most of our patients, even following complex procedures.
Direct numerical simulation is performed for flow separation over a bump in a turbulent channel. Comparisons are made between a smooth bump and one where the lee side is covered with replicas of shark denticles – dermal scales that consist of a slender base (the neck) and a wide top (the crown). As flow over the bump is under an adverse pressure gradient (APG), a reverse pore flow is formed in the porous cavity region underneath the crowns of the denticle array. Remarkable thrust is generated by the reverse pore flow as denticle necks accelerate the fluid passing between them in the upstream direction. Several geometrical features of shark denticles, including some that had not previously been considered hydrodynamically functional, are identified to form the two-layer denticle structure that enables and sustains the reverse pore flow and thrust generation. The reverse pore flow is activated by the APG before massive flow detachment. The results indicate a proactive, on-demand drag reduction mechanism that leverages and transforms the APG into a favourable outcome.
Evidence abounds on the salience of attachment to early development and beyond. In 2018, Adshead distilled the relevance of 20 years of attachment theory to psychiatric practice.2 We argue research funders must move one step further: develop the evidence around perinatal attachment-informed interventions.
We explore the application of the reference map technique, originally developed for Eulerian simulation of solid mechanics, in Lagrangian kinematics of turbulent flows. Unlike traditional methods based on explicit particle tracking, the reference map facilitates the calculation of flow maps and gradients without the need for particles. This is achieved through an Eulerian update of the reference map, which records the take-off positions of fluid particles. This approach is found to be mathematically equivalent to the work of Leung (J. Comput. Phys., vol. 230, issue 9, 2011, pp. 3500–3524), who computed the flow map of simple two-dimensional flows using an Eulerian approach. We discuss important modifications necessary for its first application to complex three-dimensional turbulent flows, including the conservative, low-dissipation update of the flow map and the treatment of periodic boundary conditions. We first demonstrate the accuracy of finite-time Lyapunov exponent (FTLE) calculations based on the reference map against the standard particle-based approach in a two-dimensional Taylor–Green vortex. Then we apply it to turbulent channel flow at $Re_\tau =180$, where Lagrangian coherent structures identified as ridges of the backward-time FTLE are found to bound vortical regions of flow, consistent with Eulerian coherent structures from the $Q$-criterion. The reference map also proves suitable for material surface tracking despite not explicitly tracking particles. This capability can provide valuable insights into the Lagrangian landscape of turbulent momentum transport, complementing Eulerian velocity field analysis. The evolution of initially wall-normal material surfaces in the viscous sublayer, buffer layer and log layer sheds light on the Reynolds stress-generating events from a Lagrangian perspective.
Viruses present an amazing genetic variability. An ensemble of infecting viruses, also called a viral quasispecies, is a cloud of mutants centered around a specific genotype. The simplest model of evolution, whose equilibrium state is described by the quasispecies equation, is the Moran–Kingman model. For the sharp-peak landscape, we perform several exact computations and derive several exact formulas. We also obtain an exact formula for the quasispecies distribution, involving a series and the mean fitness. A very simple formula for the mean Hamming distance is derived, which is exact and does not require a specific asymptotic expansion (such as sending the length of the macromolecules to $\infty$ or the mutation probability to 0). With the help of these formulas, we present an original proof for the well-known phenomenon of the error threshold. We recover the limiting quasispecies distribution in the long-chain regime. We try also to extend these formulas to a general fitness landscape. We obtain an equation involving the covariance of the fitness and the Hamming class number in the quasispecies distribution. Going beyond the sharp-peak landscape, we consider fitness landscapes having finitely many peaks and a plateau-type landscape. Finally, within this framework, we prove rigorously the possible occurrence of the survival of the flattest, a phenomenon which was previously discovered by Wilke et al. (Nature 412, 2001) and which has been investigated in several works (see e.g. Codoñer et al. (PLOS Pathogens2, 2006), Franklin et al. (Artificial Life25, 2019), Sardanyés et al. (J. Theoret. Biol.250, 2008), and Tejero et al. (BMC Evolutionary Biol.11, 2011)).
Increasing transboundary crises necessitate the development of crisis management capabilities that transcend boundaries. In such situations, inter-governmental and cross-functional collaboration has become a common practice to address the complexities of governance challenges. This study employs Social Network Analysis to examine the structure, function, and evolution of policy collaboration networks in China in response to COVID-19 and SARS. Since the SARS outbreak, China has embraced a collaborative governance approach, considering the transboundary nature of COVID-19. This approach has led to the involvement of numerous specialized organizations engaged in economic and social development, contributing to the establishment of a larger and more loosely connected collaboration network. While the health department bears the primary responsibility for coordinating public health emergency management, diverse organizations with social governance and economic management functions have also emerged as key actors, providing crucial anti-epidemic information, knowledge, and resources to address this significant cross-border crisis.
Understanding why animals choose one food over another is one of the key questions underlying the fields of behaviour ecology. This study aims to test if ladybird beetle, Propylea dissecta Mulsant (Coleoptera: Coccinellidae) can forage selectively for nutrients in order to redress specific nutritional imbalances to maximise their fitness. We hypothesised that the presence of more food choices leads to bad decisions in terms of their food selection which ultimately negatively affects the mating and reproductive parameters of P. dissecta. To test this, we first manipulated the predator's nutritional status by rearing them in five separate dietary groups from first instar larvae to newly emerged adult stage. Thereafter, we tested their food choice between five different foods, i.e. Aphis craccivora Koch, Aphis nerii Boyer de Fonsclombe, conspecific eggs, heterospecific eggs and mixed pollen grains, equidistantly placed in a Petri dish. Based on the food choice of the newly emerged adults, they were reared on the chosen diet for 10 days. Thereafter, adults were paired with their opposite sex (collected from stock culture reared on A. craccivora) and mating and reproductive parameters were recorded. Our results suggested that the variety of food did not affect the food choice of ladybird beetle, P. dissecta. They tend to choose their natural diet, i.e. aphid in each dietary regime. We found that previous dietary regime, i.e. larval dietary regime, significantly influences the mating and reproductive parameters of both the male and female except for the time to commence mating by the male. Food choices of adult beetles were found to significantly influence the time to commence mating, average fecundity and per cent egg viability in males and only mating duration in females. Our findings suggest that P. dissecta consistently made optimal decisions when facing various food choices. They consistently preferred their natural and preferred food choice over others, indicating a strong food selection behaviour.
The literature on representation has shown that those who reflect the characteristics, traits, and/or experiences of a group (descriptive representation) are more likely to represent that group’s interests (substantive representation). In this paper, we argue that questions about representation should be considered with regard to generational identity. Drawing upon research that shows the importance of the Millennial Generation identity for understanding Millennials’ attitudes and policy preferences, we look at whether this identity matters for the legislative representation of group interests by examining bill sponsorship activity in 31 state legislatures. Our results tentatively support the expectation that the Millennial generation identity conditions the sponsorship of Millennial interest bills. Millennial legislators are more likely than non-Millennial legislators to sponsor bills that disproportionately impact their group members. This result is observed among both Democrat and Republican legislators, but at different magnitudes and for different issue priorities. These findings suggest that the Millennial generation identity is a meaningful determinant of legislative behavior, even when examined alongside partisanship.
Leader exemplification involves implicit and explicit claims of high moral values made by a leader. We employed a 2 × 3 experimental design with samples of 265 students in Study 1 and 142 working adults in Study 2 to examine the effects of leader exemplification (exemplification versus no exemplification) and ethical conduct (self-serving, self-sacrificial, and self-other focus) on perceived leader authenticity, trust in leader, and organizational advocacy. In Study 1, we found that exemplification produced elevated levels of perceived authenticity, trust, and advocacy in the form of employment and investment recommendations. We also showed that leader ethical conduct moderated this effect, as ratings were highest following a leader’s self-sacrificial conduct, lowest for self-serving conduct, and moderate for conduct reflecting self-other concerns. In Study 2, we replicated these findings for perceived authenticity and trust, but not organizational advocacy, which yielded mixed results. The leadership implications and future research directions are discussed.
One-bit coding metasurfaces combine two basic unit cells with out-of-phase responses. Their potential in achieving diffuse scattering has already been demonstrated. These metasurfaces can subsequently be applied to radar-signature control. This paper presents a theoretical analysis linking the scattered field to the autocorrelation of the code that encodes the metasurface. This analysis leads to a focus on Minimum Peak Sidelobes codes with autocorrelation characteristics similar to the unit impulse. Advances in other research areas have greatly enhanced the search for these kind of codes, making them directly usable for coding diffuse scattering metasurfaces. This approach is compared with existing codes, specifically examining how it performs against the optimal code found through exhaustive search in small-scale scenarios. Then, it is shown that this coding strategy facilitates the design of metasurfaces with any and large electrical sizes, achieving results comparable to those obtained through optimization-based approaches, at a significantly reduced computational workload.
Biber, Szmrecsanyi, Reppen & Larsson (2023) argue for a more liberal inclusion of genitive variants, evoking Labov's principle of accountability (Labov 1969: 737–8, fn. 20, 1972), which calls for the inclusion of all variants that are functionally equivalent and allow variation. They suggest that the term ‘genitive’ should be defined grammatically, as a restrictive modifier to the head noun, rather than semantically in terms of a possessive relation, thus redefining the linguistic variable for English genitive variation. In particular, they include noun modifiers as a third genitive variant (with s-genitives and of-genitives). In this reply I argue that the authors proceed from a notion of ‘genitive’ that is too broad, including variants that are not functionally equivalent and contexts that are not variable, thus actually violating the principle of accountability.
Although ethics is increasingly integrated in the curriculum of U.S. medical schools, it remains not well integrated with system issues, and social and structural contexts of illness. Moreover, ethical analysis is not often taught as a clinical skill. To address these issues, an outcomes driven course in Social Sciences, Humanities, Ethics and Professionalism (SHEP) was created. Within the course, a web-based concept mapping device, SHEP Case Analysis Tool (SCAT), was created which schematizes the structure and flow of clinical cases from diagnosis to treatment options, to shared decision making to outcome, and includes key stakeholders, influences, and structural features of the health system. In the course, each student analyzes a case in which they were directly involved using SCAT and presents their analysis to faculty and peers. This exercise 1) reinforces knowledge-based portions of the course pedagogy, 2) supports meta-cognition and critical thinking through concept mapping, 3) applies multidimensional analysis to identify ethical, social, and system issues that impact patient-care. 4) develops problem solving skills, 5) counters the hidden curriculum/support professional identity formation, and 6) develops skills in reflective discourse. This paper outlines the development and use of this concept mapping case analysis tool in an undergraduate medical education curriculum.
This article describes an innovative program to provide safe, evidence-based psychiatric care at the Baltimore Convention Center Field Hospital (BCCFH), set up for COVID-19 patients, to alleviate overextended hospitals.
Methods
This article describes the staffing and workflows utilized at the BCCFH including universal suicide risk assessment and co-management of high acuity patients by an NP-led psychiatry service.
Results
The Columbia-Suicide Screening Rating Scale (C-SSRS) proved feasible as a suicide screening tool. Using the SAFE-T protocol, interdisciplinary teams cared for moderate and low risk patients. The NP psychiatry service evaluated over 70 patients, effecting medication changes in more than half and identified and transferred several decompensating patients for higher-level psychiatric care. Group therapy attendees demonstrated high participation. There were no assaults, self-harm incidents, or suicides.
Conclusions
The BCCFH psychiatry/mental health program, a potential model for other field hospitals, promotes evidence-based, integrated care. Emphasizing safety, including suicide risk, is crucial within alternate care sites during disasters. The engagement of dually-certified (psychiatric and medical) nurse practitioners boosts safety and provides expertise with advanced medication management and psychotherapeutic interventions. Similar future sites should be ready to handle chronically ill psychiatric patients, detect high-risk or deteriorating ones, and develop therapeutic programs for patient stabilization and support.
This paper explores the intense bond formed between two Qing women, Li Ti and Huang Xunying, as well as their double suicide. The sheer survival of the rich personal and family narratives (in both poetry and prose) surrounding their relationship and suicides represents a startling discovery. By actively resisting the restrictions imposed by the patriarchal family and social order and explicitly defining an unbreakable union marked by moral commitment to and spiritual connection with each other, Li Ti and Huang embody the concept of queerness in today’s usage. The two women’s double suicide, furthermore, posed an extreme form of social protest and an individual quest for freedom. Despite being historically conditioned and ideologically mediated, the excavated primary sources, such as Li Ti’s own poems, challenge not only the norms of their time and place, but also our scholarly consensus about women’s lives in China’s past.
Household income and caregiver mental health are important drivers of children’s health and development. The COVID-19 pandemic created huge economic and mental health disruptions. This study examines financial hardship and its relationship with caregiver and child mental health using Australia’s only representative data spanning three years of the pandemic. Analysis of the repeated, cross-sectional National Child Health Poll included 12,408 caregivers and 20,339 children over six waves (June 2020–April 2023). Caregivers reported their income (dichotomised into low versus not) and deprivation (missing one or more of eight essential items, versus not) and mental health for themselves (Kessler-6, poor versus not) and each child (Self-Rated Mental Health, poor/fair versus good/very good/excellent). Binary logistic models were fitted to predict marginal probabilities of mental health measures by low income and deprivation, over time. Results show that while low income decreased from 41% to 34% over the study period, deprivation increased from 30% to 35%. Poor mental health peaked with stay-at-home orders in 2021 before recovering. Caregivers experiencing low income or deprivation had higher rates of poor mental health throughout the study and slower recovery compared to those without financial hardship. Children in families experiencing financial hardship had slightly higher proportions of poor/fair mental health in 2021–2022, but they were mostly equivalent in June 2020 and April 2023 (range 6–8%). Addressing financial hardship may offer an avenue for improving caregiver mental health. This has implications for post-pandemic recovery and addressing contemporary issues of increasing cost of living and limited mental health supports and services.