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A three-dimensional robust nonlinear cooperative guidance law is proposed to address the challenge of multiple missiles intercepting manoeuvering targets under stringent input constraints and thruster failure. The finite-time convergence theory is used to design a distributed nonlinear sliding mode guidance law, ensuring that the system converges in finite time, with the upper limit of convergence time related to the initial state. A nonlinear sliding surface is adopted to mitigate actuator saturation issues. Then, considering thruster failure, a robust cooperative guidance law is further introduced, ensuring mission completion through the reconstruction of the guidance law. The closed-loop system is proven to be stable using Lyapunov theory, and the influence of hyperparameters on the cooperative guidance law is analysed. Additionally, the results of numerical simulations and hardware-in-the-loop experiments demonstrate the effectiveness and robustness of the proposed algorithm in dealing with stringent input saturation and various disturbances.
This study presents observations of coherent modes (CMs) in a spherical tokamak using a microwave interferometer near the midplane. The CMs within the 30–60 kHz frequency range were observed during electron cyclotron resonance heating only, and the frequency of the CMs increased proportionally with the square root of the electron temperature near $R = 0.7m$. Generally, these modes displayed bursting and chirping signatures with strong density rise and fall. Their appearance indicated an increase in the intensity of hard x rays, suggesting a deterioration in energetic electron confinement. Furthermore, the effect of CMs on the intensity of energetic electron-driven whistler waves was observed. They decreased when CMs were present and gradually increased with the decrease in CM intensity. The CMs may influence the intensity of whistler waves by affecting the energetic electron confinement.
Adolescents with depression have distinct affective reactions to daily events, but current research is controversial. The emotional context insensitivity theory suggests blunted reactivity in depression, whereas the hypotheses of negative potentiation and mood brightening effect suggest otherwise. While nonlinear associations between depression severity and affective reactivity have been observed, studies with a separate subclinical group remain rare. Subthreshold depression (SD), defined by two to four symptoms lasting for two weeks or more, provides a dimensional view to the underpinnings of affective reactivity. In this study, we compared positive affect (PA) and negative affect (NA) reactivity to positive and negative daily events (uplifts and stress) among adolescents with Major Depressive Disorder (MDD), SD and healthy controls (HC) using experience sampling methods (ESM).
Objectives
We hypothesized a stepped difference in affective reactivity along the depression spectrum: the MDD group will have the strongest reactivity of PA and NA to uplifts and stress, followed by SD and HC.
Methods
Three groups (MDD, SD, and HC) of adolescents were recruited from an epidemiologic sample entitled ‘Hong Kong Child and Adolescent Psychiatric Epidemiologic Survey: Age 6 to 17’. Group status was determined by the Diagnostic Interview Schedule for Children Version 5. They completed an experience sampling diary on smartphone for 14 consecutive days, with 5-10 entries per day. Momentary levels of PA (happy, relaxed, contented), NA (irritated, low, nervous), uplifts and stress experienced before the entry were measured on a 1-7 Likert scale.
Results
The sample consisted of 19 adolescents with MDD, 30 with SD, and 59 HC. The M:F ratio was 17:19. The age range was 12-18 with a mean of 14.8. The overall ESM completion rate was 46%. The MDD group had the highest levels of stress and NA, and the lowest levels of uplifts and PA, followed by the SD and HC groups respectively (p<0.01). Across groups, levels of PA were positively associated with uplifts and negatively associated with stress, whereas levels of NA were positively associated with stress and negatively associated with uplifts. The Group x Uplift interaction effect on PA was significant, with greater PA reactivity in SD (p<0.01) and MDD (p=0.07) when compared with HC. The Group x Uplift interaction effect on NA was significant, with greater NA reactivity in SD than HC (p<0.01). The Group x Stress interaction effect on PA was significant, with greater PA reactivity in SD than HC (p<0.01) and MDD (p<0.01). The Group x Stress interaction effect with NA is non-significant.
Conclusions
Contrary to our hypothesis, adolescents with SD experienced strongest PA and NA reactivity in uplifts and PA reactivity in stress. It provides evidence towards a nonlinear relationship between severity of depression and affective reactivity.
The occurrence of depression in adolescence, a critical period of brain development, linked with neuroanatomical and cognitive abnormalities. Neuroimaging studies have identified hippocampal abnormalities in those of adolescent patients. However, few studies have investigated the atypically developmental trends in hippocampal subfields in adolescents with depression and their relationships with cognitive dysfunctions.
Objectives
To explore the structural abnormalities of hippocampal subfields in patients with youth depression and examine how these abnormalities associated with cognitive deficits.
Methods
We included a sample of 79 first-episode depressive patients (17 males, age = 15.54±1.83) and 71 healthy controls (23 males, age = 16.18±2.85). The severity of these adolescent patients was assessed by depression scale, suicidal risk and self-harm behavior. Nine cognitive tasks were used to evaluate memory, cognitive control and attention abilities for all participants. Bilateral hippocampus were segmented into 12 subfields with T1 and T2 weighted images using Freesurfer v6.0. A mixed analysis of variance was performed to assess the differences in subfields volumes between all patients and controls, and between patients with mild and severe depression. Finally, LASSO regression was conducted to explore the associations between hippocampal subfields and cognitive abnormalities in patients.
Results
We found significant subfields atrophy in the CA1, CA2/3, CA4, dentate gyrus, hippocampal fissure, hippocampal tail and molecular layer subfields in patients. For those patients with severe depression, hippocampal subfields showed greater extensive atrophy than those in mild, particularly in CA1-4 subfields extending towards the subiculum. These results were similar across various severity assessments. Regression indicated that hippocampal subfields abnormalities had the strongest associations with memory dysfunction, and relatively week associations with cognitive control and attention. Notably, CA4 and dentate gyrus had the highest weights in the regression model.
Conclusions
As depressive severity increases, hippocampal subfield atrophy tends to spread from CA regions to surrounding areas, and primarily affects memory function in patients with youth depression. These results suggest hippocampus might be markers in progression of adolescent depression, offering new directions for early clinical intervention.
Ultrafast optical probing is a widely used method of underdense plasma diagnostic. In relativistic plasma, the motion blur limits spatial resolution in the direction of motion. For many high-power lasers the initial pulse duration of 30–50 fs results in a 10–15 μm motion blur, which can be reduced by probe pulse post-compression. Here we used the compression after compressor approach [Phys.-Usp. 62, 1096 (2019); JINST 17 P07035 (2022)], where spectral broadening is performed in thin optical plates and is followed by reflections from negative-dispersion mirrors. Our initially low-intensity probe beam was down-collimated for a more efficient spectral broadening and higher probe-to-self-emission intensity ratio. The setup is compact, fits in a vacuum chamber and can be implemented within a short experimental time slot. We proved that the compressed pulse retained the high quality necessary for plasma probing.
This study presents novel findings on stochastic electron heating via a random electron cyclotron wave (ECW) in a spherical tokamak. Hard x ray measurements demonstrate the time evolution of hard x ray counts at different energy bands, consistent with predictions from the stochastic heating model. The ECW heating rate shows a positive correlation with applied power, confirming the effectiveness of stochastic heating. Remarkably, the ECW-driven plasma current remains insensitive to ECW incidence angle, consistent with model predictions. The observed stochastic heating of electrons offers potential for exploring innovative non-inductive current drive modes in spherical tokamaks. This research contributes to the understanding of plasma behaviour and motivates the development of new models for non-inductive current drive in fusion devices.
The unstart phenomenon of supersonic inlets caused by backpressure is dangerous for aircraft during flights because it severely reduces the air mass flow rate through the engine. We used unsteady numerical simulations to evaluate the unstart and restart characteristics of a two-dimensional supersonic inlet during rapid backpressure changes. The effects of the depressurisation time and depressurisation value on the inlet flow characteristics and restart features are discussed. The results show that the depressurisation time affects the restart procedure when the back pressure drops from the inlet unstart value to the normal working state value. When the depressurisation time decreases, it becomes easier for the inlet to restart. However, the inlet cannot restart if the depressurisation time is too long. When the depressurisation time and value were large enough, a short buzz period occurred before the inlet restarted. Both the time and value of depressurisation affected the restart characteristics.
This study aimed to compare the pre- and post-operative vestibular and equilibrium functions of patients with cholesteatoma-induced labyrinthine fistulas who underwent different management methods.
Methods
Data from 49 patients with cholesteatoma-induced labyrinthine fistulas who underwent one of three surgical procedures were retrospectively analysed. The three management options were fistula repair, obliteration and canal occlusion.
Results
Patients underwent fistula repair (n = 8), canal occlusion (n = 18) or obliteration procedures (n = 23). Patients in the fistula repair and canal occlusion groups suffered from post-operative vertigo and imbalance, which persisted for longer than in those in the obliteration group. Despite receiving different management strategies, all patients achieved complete recovery of equilibrium functions through persistent efforts in rehabilitation exercises.
Conclusion
Complete removal of the cholesteatoma matrix overlying the fistula is reliable for preventing iatrogenic hearing deterioration due to unremitting labyrinthitis. Thus, among the three fistula treatments, obliteration is the optimal method for preserving post-operative vestibular functions.
Unmanned aerial vehicle (UAV) swarm coverage is one of the key technologies for multi-UAV cooperation, which plays an important role in collaborative investigation, detection, rescue and other applications. Aiming at the coverage optimisation problem of UAV in the target area, a collaborative visual coverage control method under positioning uncertainty is presented. First, the visual perception area with imprecise localisation, UAV model and sensor model are created based on the given task environment. Second, a regional division algorithm for the target task area is designed based on the principle of Guaranteed Voronoi (GV) diagram. Then a visual area coverage planning algorithm is designed, in which the task area is allocated to the UAV according to the corresponding weight coefficient of each area, and the input control law is adjusted by the expected state information of the UAV, so that the optimal coverage quality target value and the maximum coverage of the target area can be achieved. Finally, three task scenarios for regional division and coverage planning are simulated respectively, the results show that the proposed area coverage planning algorithm can realise the optimal regional distribution and can obtain more than 90% coverage in different scenarios.
The spatio-temporal variation of leaf chlorophyll content is an important crop phenotypic trait that is of great significance for evaluating crop productivity. This study used a soil-plant analysis development (SPAD) chlorophyll meter for non-destructive monitoring of leaf chlorophyll dynamics to characterize the patterns of spatio-temporal variation in the nutritional status of maize (Zea mays L.) leaves under three nitrogen treatments in two cultivars. The results showed that nitrogen levels could affect the maximum leaf SPAD reading (SPADmax) and the duration of high SPAD reading. A rational model was used to measure the changes in SPAD readings over time in single leaves. This model was suitable for predicting the dynamics of the nutrient status for each leaf position under different nitrogen treatments, and model parameter values were position dependent. SPADmax at each leaf decreased with the reduction of nitrogen supply. Leaves at different positions in both cultivars responded differently to higher nitrogen rates. Lower leaves (8th–10th positions) were more sensitive than the other leaves in response to nitrogen. Monitoring the SPAD reading dynamic of lower leaves could accurately characterize and assess the nitrogen supply in plants. The lower leaves in nitrogen-deficient plants had a shorter duration of high SPAD readings compared to nitrogen-sufficient plants; this physiological mechanism should be studied further. In summary, the spatio-temporal variation of plant nitrogen status in maize was analysed to determine critical leaf positions for potentially assisting in the identification of appropriate agronomic management practices, such as the adjustment of nitrogen rates in late fertilization.
The epidemic of tuberculosis has posed a serious burden in Qinghai province, it is necessary to clarify the epidemiological characteristics and spatial-temporal distribution of TB for future prevention and control measures. We used descriptive epidemiological methods and spatial statistical analysis including spatial correlation and spatial-temporal analysis in this study. Furthermore, we applied an exponential smoothing model for TB epidemiological trend forecasting. Of 43 859 TB cases, the sex ratio was 1.27:1 (M:F), and the average annual TB registered incidence was 70.00/100 000 of 2009–2019. More cases were reported in March and April, and the worst TB stricken regions were the prefectures of Golog and Yushu. High TB registered incidences were seen in males, farmers and herdsmen, Tibetans, or elderly people. 7132 cases were intractable, which were recurrent, drug resistant, or co-infected with other infections. Three likely cases clusters with significant high risk were found by spatial-temporal scan on data of 2009–2019. The exponential smoothing winters' additive model was selected as the best-fitting model to forecast monthly TB cases in the future. This research indicated that TB in Qinghai is still a serious threaten to the local residents' health. Multi-departmental collaboration and funds special for TB treatments and control are still needed, and the exponential smoothing model is promising which could be applied for forecasting of TB epidemic trend in this high-altitude province.
The wake of an Ahmed body may be divided into high- and low-drag regimes where the rear slant angle (φ) is in the ranges of 12.5°–30° and larger than 30°, respectively. This work aims to gain a relatively thorough understanding of unsteady predominant coherent structures around an Ahmed body of φ = 35° in the low-drag regime. Extensive hot-wire, wall pressure, flow visualization and particle image velocimetry measurements have been conducted at Reynolds number $Re \in [0.3,2.7] \times {10^5}$, based on the square root of the model's frontal area. A total of five distinct Strouhal numbers have been identified in the wake. One of them, Stw ≈ 0.30, is captured behind the vertical base, which is associated with the structures that emanate from the upper recirculation bubble and pinch off from the lower bubble, respectively. It is found that Stw scales with a characteristic length αS, which reflects physically the bubble size, and the Strouhal number $St_w^ + $ based on αS is a constant 0.20, irrespective of the value of φ. A corner vortex rolling upstream is observed near the lower end of the slanted surface, whose formation mechanism and dynamical role are discussed. The Reynolds-number effect on the flow is also documented. Based on the present and previously reported data, a conceptual flow structure model is proposed for a low-drag Ahmed body, including both steady and unsteady coherent structures around the body.
Late-life depression has substantial impacts on individuals, families and society. Knowledge gaps remain in estimating the economic impacts associated with late-life depression by symptom severity, which has implications for resource prioritisation and research design (such as in modelling). This study examined the incremental health and social care expenditure of depressive symptoms by severity.
Methods
We analysed data collected from 2707 older adults aged 60 years and over in Hong Kong. The Patient Health Questionnaire-9 (PHQ-9) and the Client Service Receipt Inventory were used, respectively, to measure depressive symptoms and service utilisation as a basis for calculating care expenditure. Two-part models were used to estimate the incremental expenditure associated with symptom severity over 1 year.
Results
The average PHQ-9 score was 6.3 (standard deviation, s.d. = 4.0). The percentages of respondents with mild, moderate and moderately severe symptoms and non-depressed were 51.8%, 13.5%, 3.7% and 31.0%, respectively. Overall, the moderately severe group generated the largest average incremental expenditure (US$5886; 95% CI 1126–10 647 or a 272% increase), followed by the mild group (US$3849; 95% CI 2520–5177 or a 176% increase) and the moderate group (US$1843; 95% CI 854–2831, or 85% increase). Non-psychiatric healthcare was the main cost component in a mild symptom group, after controlling for other chronic conditions and covariates. The average incremental association between PHQ-9 score and overall care expenditure peaked at PHQ-9 score of 4 (US$691; 95% CI 444–939), then gradually fell to negative between scores of 12 (US$ - 35; 95% CI - 530 to 460) and 19 (US$ -171; 95% CI - 417 to 76) and soared to positive and rebounded at the score of 23 (US$601; 95% CI -1652 to 2854).
Conclusions
The association between depressive symptoms and care expenditure is stronger among older adults with mild and moderately severe symptoms. Older adults with the same symptom severity have different care utilisation and expenditure patterns. Non-psychiatric healthcare is the major cost element. These findings inform ways to optimise policy efforts to improve the financial sustainability of health and long-term care systems, including the involvement of primary care physicians and other geriatric healthcare providers in preventing and treating depression among older adults and related budgeting and accounting issues across services.
This study was a retrospective multicentre cohort study of patients with coronavirus disease 2019 (COVID-19) diagnosed at 24 hospitals in Jiangsu province, China as of 15 March 2020. The primary outcome was the occurrence of acute respiratory failure during hospital stay. Of 625 patients, 56 (9%) had respiratory failure. Some selected demographic, epidemiologic, clinical and laboratory features as well as radiologic features at admission and treatment during hospitalisation were significantly different in patients with and without respiratory failure. The multivariate logistic analysis indicated that age (in years) (odds ratio [OR], 1.07; 95% confidence interval [CI]: 1.03–1.10; P = 0.0002), respiratory rate (breaths/minute) (OR, 1.23; 95% CI: 1.08–1.40; P = 0.0020), lymphocyte count (109/l) (OR, 0.18; 95% CI: 0.05–0.69; P = 0.0157) and pulmonary opacity score (per 5%) (OR, 1.38; 95% CI: 1.19–1.61; P < 0.0001) at admission were associated with the occurrence of respiratory failure. Older age, increased respiratory rate, decreased lymphocyte count and greater pulmonary opacity score at admission were independent risk factors of respiratory failure in patients with COVID-19. Patients having these risk factors need to be intensively managed during hospitalisation.
Families facing end-stage nonmalignant chronic diseases (NMCDs) are presented with similar symptom burdens and need for psycho-social–spiritual support as their counterparts with advanced cancers. However, NMCD patients tend to face more variable disease trajectories, and thus may require different anticipatory supports, delivered in familiar environments. The Life Rainbow Programme (LRP) provides holistic, transdisciplinary, community-based end-of-life care for patients with NMCDs and their caregivers. This paper reports on the 3-month outcomes using a single-group, pre–post comparison.
Method
Patients with end-stage NMCDs were screened for eligibility by a medical team before being referred to the LRP. Patients were assessed at baseline (T0), 1 month (T1), and 3 months (T2) using the Integrated Palliative Outcome Scale (IPOS). Their hospital use in the previous month was also measured by presentations at accident and emergency services, admissions to intensive care units, and number of hospital bed-days. Caregivers were assessed at T0 and T2 using the Chinese version of the Modified Caregiver Strain Index, and self-reported health, psychological, spiritual, and overall well-being. Over-time changes in outcomes for patients, and caregivers, were tested using paired-sample t-tests, Wilcoxon-signed rank tests, and chi-square tests.
Results
Seventy-four patients and 36 caregivers participated in this research study. Patients reported significant improvements in all IPOS domains at both 1 and 3 months [ranging from Cohen's d = 0.495 (nausea) to 1.793 (depression and information needs fulfilled)]. Average hospital bed-days in the previous month fell from 3.50 to 1.68, comparing baseline and 1 month (p < 0.05). At 3 months, caregiver strain was significantly reduced (r = 0.332), while spiritual well-being was enhanced (r = 0.333).
Significance
After receiving 3 month's LRP services, patients with end-stage NMCDs and their caregivers experienced significant improvements in the quality of life and well-being, and their hospital bed-days were reduced.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
The pandemic of coronavirus disease 2019 (COVID-19) has posed serious challenges. It is vitally important to further clarify the epidemiological characteristics of the COVID-19 outbreak for future study and prevention and control measures. Epidemiological characteristics and spatial−temporal analysis were performed based on COVID-19 cases from 21 January 2020 to 1 March 2020 in Shandong Province, and close contacts were traced to construct transmission chains. A total of 758 laboratory-confirmed cases were reported in Shandong. The sex ratio was 1.27: 1 (M: F) and the median age was 42 (interquartile range: 32–55). The high-risk clusters were identified in the central, eastern and southern regions of Shandong from 25 January 2020 to 10 February 2020. We rebuilt 54 transmission chains involving 209 cases, of which 52.2% were family clusters, and three widespread infection chains were elaborated, occurring in Jining, Zaozhuang and Liaocheng, respectively. The geographical and temporal disparity may alert public health agencies to implement specific measures in regions with different risk, and should attach importance on how to avoid household and community transmission.