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This paper examines the aeroelastic stability of uniform flexible wings imperfectly supported at one end and free at the other. Real-world aircraft wings inevitably exhibit imperfections, including non-ideal end supports. This work is motivated by the critical need to fundamentally understand how end-support imperfections influence the aeroelastic behaviour of fixed wings. The equations of motion are obtained via the extended Hamilton’s principle. The bending-torsional dynamics of the wing is approximated using the Euler-Bernoulli beam theory. The aerodynamic lift and pitching moment are modelled using the unsteady aerodynamics for the arbitrary motion of thin aerofoils in the time domain, extended by the strip flow theory. The imperfect support is modelled via rotational springs (with linear stiffness) for both bending and torsional degrees of freedom. The Galerkin method is used for the spatial discretisation. The stability analysis is performed by solving the resulting eigenvalue problem, and the numerical results are presented in Argand diagrams. The numerical results presented in this study are novel and offer great insights. It is demonstrated that support imperfections can substantially influence the critical flow velocity for both flutter and divergence, as well as alter the sequence of instabilities and the unstable mode. The extent of these effects directly depends on the magnitude of the imperfections. Interestingly–and counterintuitively–in certain cases, a reduction in the flutter speed is observed as the imperfections decrease.
Long-duration and time-resolved particle image velocimetry measurements were conducted in rough-wall open channel flows (OCFs), with the friction Reynolds number ranging from 642 to 2034. The primary objective is to investigate the impacts of various turbulent motions at different scales on the mean wall-shear stress ($\langle \tau _w \rangle$). To achieve this aim, a physical decomposition of $\langle \tau _w \rangle$ was initially performed utilizing the double-averaged methodology proposed by Nikora et al. (2019 J. Fluid Mech. 872, 626–664). This method enabled the breakdown of $\langle \tau _w \rangle$ into three distinct constituents: viscous, turbulent and dispersive stress segments. The findings underscore the substantial roles that turbulent and dispersive stresses play, accounting for over 75 % and 9 % of $\langle \tau _w \rangle$, respectively. Subsequently, a scale decomposition was further applied to analyse the contributions of coherent motions at different scales to $\langle \tau _w \rangle$. Adopting typical cutoff streamwise wavelengths ($\lambda _x = 3h$ and $10h$), the contribution of large-scale motions (LSMs) and very large-scale motions (VLSMs) to the overall wall-shear stress was quantified. It was revealed that turbulent motions with $\lambda _x \gt 3h$ and $\lambda _x \gt 10h$ contribute more than 40 % and 18 % of $\langle \tau _w \rangle$, respectively. The scale decomposition of the wall-shear stress and the contribution from LSMs and VLSMs exhibit evident dependencies on the Reynolds number. The contribution of LSMs and VLSMs to $\langle \tau _w \rangle$ is lower in rough OCFs compared with those of smooth counterparts. Secondary currents induced by the rough wall are hypothesised to be responsible for the reduced strength of LSMs and VLSMs and decreases in their contribution to $\langle \tau _w \rangle$.
Major depressive disorder (MDD) and insulin resistance-related conditions are major contributors to global disability. Their co-occurrence complicates clinical outcomes, increasing mortality and symptom severity.
Aims
In this study, we investigated the association of insulin resistance-related conditions and related polygenic scores (PGSs) with MDD clinical profile and treatment outcomes, using primary care records from UK Biobank.
Method
We identified MDD cases and insulin resistance-related conditions, as well as measures of depression treatment outcomes (e.g. resistance) from the records. Clinical-demographic variables were derived from self-reports, and insulin resistance-related PGSs were calculated using PRS-CS. Univariable analyses were conducted to compare sociodemographic and clinical variables of MDD cases with (IR+) and without (IR−) lifetime insulin resistance-related conditions. Multiple regressions were performed to identify factors, including insulin resistance-related PGSs, potentially associated with treatment outcomes, adjusting for confounders.
Results
Among 30 919 MDD cases, 51.95% were IR+. These had more antidepressant prescriptions and classes utilisation and longer treatment duration than patients without insulin resistance-related conditions (P < 0.001). IR+ participants showed distinctive depressive profiles, characterised by concentration issues, loneliness and inadequacy feelings, which varied according to the timing of MDD diagnosis relative to insulin resistance-related conditions. After adjusting for confounders, insulin resistance-related conditions (i.e. cardiovascular diseases, hypertension, non-alcoholic fatty liver disease, obesity/overweight, prediabetes and type 2 diabetes mellitus) were associated with antidepressant non-response/resistance and longer treatment duration, particularly when MDD preceded insulin resistance-related conditions. No significant PGS associations were found with antidepressant treatment outcomes.
Conclusions
Our findings support an integrated treatment approach, prioritising both psychiatric and metabolic health, and public health strategies aimed at early intervention and prevention of insulin resistance in MDD.
The important role of the saccule is the sensing of gravity. In other words, gravity always stimulates the macula of the saccule.
Objectives
The aim of this study was to clarify whether nystagmus and dizziness occur by intentional changes upon stimulation to the saccules.
Methods
The subjects were eight healthy humans. Experiment 1: Subjects were asked to maintain a supine position to check for nystagmus and dizziness. Experiment 2: Subjects were asked to tilt their heads 45º to the left in the supine position to check for nystagmus and dizziness. Experiment 3: Subjects were asked to maintain a left-ear-down 90º position to check for nystagmus and dizziness.
Results
In all the experiments, no one revealed nystagmus and no one complained of dizziness.
Conclusion
Neither nystagmus nor dizziness occurs by intentional changes in the stimulation to the saccules.
Competing and complementary risk (CCR) problems are often modelled using a class of distributions of the maximum, or minimum, of a random number of independent and identically distributed random variables, called the CCR class of distributions. While CCR distributions generally do not have an easy-to-calculate density or probability mass function, two special cases, namely the Poisson–exponential and exponential–geometric distributions, can easily be calculated. Hence, it is of interest to approximate CCR distributions with these simpler distributions. In this paper, we develop Stein’s method for the CCR class of distributions to provide a general comparison method for bounding the distance between two CCR distributions, and we contrast this approach with bounds obtained using a Lindeberg argument. We detail the comparisons for Poisson–exponential, and exponential–geometric distributions.
Interfacility patient transfers contribute to the regional spread of multidrug-resistant organisms (MDROs). We evaluated whether transfer patterns of inpatients with similar characteristics to carbapenem-resistant Enterobacterales (CRE) case-patients (CRE surrogates) better reflect hospital-level CRE burden than traditionally used populations.
Design:
We determined the risk factors for subsequent hospital admission using demographic and clinical information from Tennessee Department of Health tracked CRE case-patients from July 2015 to September 2019. Risk factors were used to identify CRE surrogates among inpatients in the 2018 Tennessee Hospital Discharge Data System (HDDS). Transfer networks of CRE surrogates, Medicare/TennCare beneficiaries, and all-inpatients with ≤365 days of intervening community stays were compared with the transfer networks of CRE case-patients in 2019. The associations between hospital-level CRE prevalence and hospitals’ incoming transfer volumes from each network were assessed using negative binomial regression models.
Results:
Eight risk factors for subsequent hospital admission were identified from 2,518 CRE case-patients, which were used to match CRE case-patients with HDDS inpatients, resulting in 10,069 surrogate patients. CRE surrogate network showed more structural similarities with the CRE case-patient network than with the all-inpatient and Medicare/TennCare networks. A 33% increase in hospitals’ CRE prevalence in 2019 was associated with each doubling of incoming transfer of CRE surrogates in 2018 (adjusted Risk Ratio [aRR] 1.33, 95%CI: 1.1, 1.59), higher than all-inpatient (aRR 1.27, 95% CI: 1.08, 1.51) and Medicare/TennCare networks (aRR 1.21, 95% CI: 1.02, 1.44).
Conclusions:
Surrogate transfer patterns were associated with hospital-level CRE prevalence, highlighting their value in MDRO containment and prevention.
In Ghana, the institution of chieftaincy, a traditional political governance system, is saddled with a number of conflicts which have far-reaching implications for food security in affected communities. This study examined how the infamous Bimbilla chieftaincy conflicts in the Northern Region of Ghana undermined the food security situation in the context of hunger, famine and sudden rise in food prices. A total of 383 respondents were randomly and purposely selected in a convergent mixed-methods study design. Questionnaires, interviews and focus group discussions were the main primary data collection methods. The study revealed that the chieftaincy conflicts significantly impacted hunger (β = –0.152, t = –2.807, p = 0.005) and famine (β = 0.188, t = 3.443, p = 0.001). A sudden increase in food prices (β = 0.006, t = 0.113, p = 0.910) stood as the only food security factor which was not affected substantially by the chieftaincy conflicts.
Trajectory optimization is a critical research area in robotics and automation, especially in manufacturing industries where mechanical systems are often required to minimize the execution time or the consumed energy. In this context, the most common mechanical systems are those with a single degree of freedom because of their simplicity and ease of control. In this paper, we present an approach for the online optimization of minimum-time and minimum-energy trajectories for a robotic system with one degree of freedom. Point-to-point motions of the considered linear axis are planned online, without idle times, by leveraging a verified dynamic model of the robotic system, which also includes an accurate identification of friction parameters. Both minimum-time and minimum-energy trajectories are considered, and the performance of the online optimization using a selected open-source optimization tool is verified in different dynamic conditions of the system. The results of extensive experiments on a belt-driven robotic axis demonstrate the feasibility and the energy-saving capabilities of the proposed approach, as well as the flexibility of the online trajectory optimization in different scenarios, while meeting the kinematics and dynamics limits of the system and guaranteeing low computational time.
Cognitive therapy for post-traumatic stress disorder (PTSD) is recommended in a range of national and international guidelines. This clinical guidance paper specifically focuses on cognitive therapy for PTSD (CT-PTSD) where racism has been part of the index trauma event(s). It aims to support CBT therapists to maintain fidelity to the CT-PTSD model but also ensure that racism is integrated into the formulation and interventions in ways that are sensitive and validating. It explores barriers to this occurring ranging from societal factors (e.g. ongoing racism, discouragement from discussing racism), to therapist factors (e.g. lack of understanding of racism, lack of own understanding of racialised identity, anxiety, lack of knowledge, skills and confidence) and patient factors (e.g. shame, fear of therapist response). The paper aims to provide guidance on how these can be addressed alongside case illustrations and practical considerations for therapists and supervisors.
Key learning aims
(1) To understand how Ehlers and Clark’s (2000) cognitive model and related treatment of PTSD can be applied when racism is part of the traumatic event.
(2) To provide guidance, tips and examples on how to identify key personal meanings around the trauma index event involving racism.
(3) The article will encourage therapists to reflect on their own identity and experiences (or lack of) around racism, considering how this might hinder or facilitate the appropriate inclusion of racist experience within CT-PTSD.
(4) To provide suggestions on how to ensure that supervision of CT-PTSD supports the consideration and addressing of relevant experiences of racism and supports therapists where patient experiences may overlap with their own experience of racism.
Efficient local trajectory optimization of the coordinated manipulator is a bottleneck task in the narrow feeding scenario. To optimize the trajectory locally and generate collision-free trajectories with local support performance, the analytical reinforcement method is proposed. Firstly, multiple coordinated machines operating in the narrow space are transformed into decentralized dynamic constraints for the target manipulator. Combined with the circle envelope method in the dynamic constraint, the collision-free gradient optimization function determines the support region of the local optimal trajectory. Based on the forward kinematics and inverse kinematics method, the collision-prone pose of the target manipulator outside the support region is analytically optimized. And chi-square distribution further ensures the smooth interpolation of the variable-period trajectory outside the fixed-period support region. For the emergency collision avoidance of the coordinated manipulator in the flexible stamping line, the analytical reinforcement method is successfully verified by generating the collision-free and smooth trajectory. It provides an optimization direction for rapidly improving the work efficiency of multi-machine coordination in the narrow feeding scenario.
Accumulating evidence shows that an increasing number of children and young people (CYP) are reporting mental health problems.
Aims
To investigate emotional disorders (anxiety or depression) among CYP in England between 2004 and 2017, and to identify which disorders and demographic groups have experienced the greatest increase.
Method
Repeated cross-sectional, face-to-face study using data from the Mental Health of Children and Young People surveys conducted in 2004 and 2017, allowing use of nationally representative probability samples of CYP aged 5–16 years in England. A total of 13 561 CYP were included across both survey waves (6898 in 2004 and 6663 in 2017). We assessed the prevalence of any emotional, anxiety and depressive disorder assessed using the Development and Well-Being Assessment and classified according to ICD-10 criteria.
Results
The prevalence of emotional disorders increased from 3.9% in 2004 to 6.0% in 2017, a relative increase of 63% (relative ratio 1.63, 95% CI 1.38, 1.91). This was largely driven by anxiety disorders, which increased from 3.5 to 5.4% (relative ratio 1.63, 95% CI 1.37, 1.93). The largest relative changes were for panic disorder, separation anxiety, social phobia and post-traumatic stress disorder. Changes were similar for different genders and socioeconomic groups, but differed by ethnicity: the most pronounced increase was among White CYP (relative ratio 1.88, 95% CI 1.59, 2.24), compared with no clear change for Black and minority ethnic CYP (relative ratio 0.85, 95% CI 0.52, 1.39). Comorbid psychiatric conditions were present in over a third of CYP with emotional disorders, with the most common being conduct disorder.
Conclusions
Between 2004 and 2017, the increase in emotional disorders among CYP in England was largely driven by anxiety disorders. Socioeconomic inequalities did not narrow. Disaggregating by ethnicity, change was evident only in White CYP, suggesting differential trends in either risk exposure, resilience or reporting by ethnicity.
A linear stability model based on a phase-field method is established to study the formation of ripples on the ice surface. The pattern on horizontal ice surfaces, e.g. glaciers and frozen lakes, is found to be originating from a gravity-driven instability by studying ice–water–air flows with a range of water and ice thicknesses. Contrary to gravity, surface tension and viscosity act to suppress the instability. The results demonstrate that a larger value of either water thickness or ice thickness corresponds to a longer dominant wavelength of the pattern, and a favourable wavelength of 90 mm is predicted, in agreement with observations from nature. Furthermore, the profiles of the most unstable perturbations are found to be with two peaks at the ice–water and water–air interfaces whose ratio decreases exponentially with the water thickness and wavenumber.
The objective is to determine if a practical face-to-face emergency disaster incident response training program delivered in the clinical setting will improve self-reported confidence and assessed knowledge of emergency department (ED) nurses to respond to disasters.
Methods
A single site prospective pre-test and post-test randomized controlled trial was adopted for this study. The intervention was a practical face-to-face training program, while the control group completed the required annual mandatory hospital online training.
Results
There was a large difference in post-test median self-reported confidence between groups. There was also a large difference in the proportion of subjects who reached satisfactory levels of self-reported confidence post-test. Regarding assessed knowledge, there was a moderate difference in post-test median knowledge between groups. There was also a moderate difference in the proportion who reached satisfactory levels of knowledge post-test.
Conclusions
This study has shown that ED nurses who undertake a practical face-to-face disaster preparedness education program in the clinical setting, are better prepared to respond to emergency disaster incidents. Organizations should consider the use of a practical structured face-to-face emergency disaster incident response education program to complement and enhance any online emergency and disaster training.
In this work, a systematic study is carried out concerning the dynamic behaviour of finite-size spheroidal particles in non-isothermal shear flows between parallel plates. The simulations rely on a hybrid method combining the lattice Boltzmann method with a finite-difference solver. Fluid–particle and heat–particle interactions are accounted for by using the immersed boundary method. The effect of particle Reynolds number ($\textit{Re}_p=1{-}90$), Grashof number (${Gr}=0{-}200$), initial position and initial orientation of the particle are thoroughly examined. For the isothermal prolate particle, we observed that above a certain Reynolds number, the particle undergoes a pitchfork bifurcation; at an even higher Reynolds number, it returns to the centre position. In contrast, the hot particle behaves differently, with no pitchfork bifurcation. Instead, the Reynolds and Grashof numbers can induce oscillatory tumbling or log-rolling motions in either the lower or upper half of the channel. Heat transfer also plays an important role: at low Grashof numbers, the particle settles near the lower wall, while increasing the Grashof number shifts it towards the upper side. Moreover, the presence of thermal convection increases the rotational speed of the particle. Surprisingly, beyond the first critical Reynolds number, the equilibrium position of the thermal particle shifts closer to the centreline compared with that of a neutrally buoyant isothermal particle. Moreover, higher Grashof numbers can cause the particle to transition from tumbling to log-rolling or even a no-rotation mode. The initial orientation has a stronger influence at low Grashof numbers, while the initial position shows no strong effect in non-isothermal cases.