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Discover the principles of wireless power transfer for unmanned aerial vehicles, from theoretical modelling to practical applications. This essential guide provides a complete technical perspective and hands-on experience. It combines in-depth theoretical models, such as T-models and M-models, with practical system design, including wireless charging system construction. It presents systematic solutions to real-world challenges in UAV wireless charging, such as mutual inductance disturbances and lightweight units. Providing the resources to tackle complex industry problems this book covers the latest technological insights including advanced control methods, such as PT-symmetric WPT system control schemes and charging range extension techniques. Ideal for professional engineers, designers, and researchers, it provides the tools needed to innovate in UAV technology and power systems. Whether you're developing new systems or optimizing existing ones, this comprehensive resource delivers the insights and techniques to drive progress in wireless power transfer for unmanned aircraft.
Extant studies on cross-border venture capital (VC) investment predominantly focus on how country-level formal institutions impact the flow of VCs across borders, but the potential role of country-level sentiments in this process has received less attention. Drawing upon the trust literature, we explore how home country political sentiment affects cross-border VC investment. Using data on Chinese VCs’ cross-border investments from 2000 to 2021, we find that home country political sentiment positively affects the amount of cross-border VC investment. Government VC (GVC) and connected VC (through sentiment transmission) positively, while investor managerial team education and investor host country experience (through sentiment suppression) negatively, moderate the influence of home country political sentiment.
The heating effect of electromagnetic waves in ion cyclotron range of frequencies (ICRFs) in magnetic confinement fusion device is different in different plasma conditions. In order to evaluate the ICRF heating effect in different plasma conditions, we conducted a series of experiments and corresponding TRANSP simulations on the EAST tokamak. Both simulation and experimental results show that the effect of ICRF heating is poor at low core electron density. The decrease in electron density changes the left-handed electric field near the resonant layer, resulting in a significant decrease in the power absorbed by the hydrogen fundamental resonance. However, quite a few experiments must be performed in plasma conditions with low electron density. It is necessary to study how to make ICRF heating best in low electron density plasma. Through a series of simulation scans of the parallel refractive index (n//) of the ICRF antenna, it is concluded that the change of the ICRF antenna n// will lead to the change of the left-handed electric field, which will change the fundamental absorption of ICRF power by the hydrogen minority ions. Fully considering the coupling of ion cyclotron wave at the tokamak boundary and the absorption in the plasma core, optimizing the ICRF antenna structure and selecting appropriate parameters such as parallel refractive index, minority ion concentration, resonance layer position, plasma current and core electron temperature can ensure better heating effect in the ICRF heating experiments in the future EAST upgrade. These results have important implications for the enhancement of the auxiliary heating effect of EAST and other tokamaks.
A Chebyshev-distributed 1 × 8 beamforming network with improved phase flatness is presented, where four beams with constant beam pointing and low sidelobe levels (SLL) can be generated. It consists of two arbitrary-amplitude 4 × 4 Blass-like matrices and one 1 × 8 switch control circuit. The newly introduced 4 × 4 Blass-like matrices can obtain arbitrary amplitude and phase differences by adjusting the transmission coefficient and phase of each unit. Besides, four output phase differences can be generated by controlling the 1 × 8 switch control circuit. An example is implemented for validation and phase compensation method is adopted for minimizing the phase difference error within the operated bandwidth to maintain constant beam pointing. Measurements show that the prototype exhibits output amplitude ratios of 0.143:0.341: 0.71:1:1:0.71:0.341:0.143, which fits the Chebyshev distribution. Under the criterion of |S11| < −10 dB, an overlapped fractional bandwidth of 24.1% is obtained. In addition, from 5.5 to 6.1 GHz (10.3%), the maximum amplitude and phase difference errors are 1.5 dB and 15°, respectively. Finally, the proposed network is connected to a 1 × 8 array. Within 10.3% bandwidth, the SLLs of less than −20 dB are realized without beam-pointing deviation.
Major depressive disorder (MDD) and psychostimulant use disorder (PUD) are common, disabling psychopathologies that pose a major public health burden. They share a common behavioral phenotype: deficits in inhibitory control (IC). However, whether this is underpinned by shared neurobiology remains unclear. In this meta-analytic study, we aimed to define and compare brain functional alterations during IC tasks in MDD and PUD.
Methods
We conducted a systematic literature search on IC task-based functional magnetic resonance imaging studies in MDD and PUD (cocaine or methamphetamine use disorder) in PubMed, Web of Science, and Scopus. We performed a quantitative meta-analysis using seed-based d mapping to define common and distinct neurofunctional abnormalities.
Results
We identified 14 studies comparing IC-related brain activation in a total of 340 MDD patients with 303 healthy controls (HCs), and 11 studies comparing 258 PUD patients with 273 HCs. MDD showed disorder-differentiating hypoactivation during IC tasks in the median cingulate/paracingulate gyri relative to PUD and HC, whereas PUD showed disorder-differentiating hypoactivation relative to MDD and HC in the bilateral inferior parietal lobule. In conjunction analysis, hypoactivation in the right inferior/middle frontal gyrus was common to both MDD and PUD.
Conclusions
The transdiagnostic neurofunctional alterations in prefrontal cognitive control regions may underlie IC deficits shared by MDD and PUD, whereas disorder-differentiating activation abnormalities in midcingulate and parietal regions may account for their distinct features associated with disturbed goal-directed behavior.
Using three waves (2011–15) of CHARLS data, we analyze the short-term effects of widowhood on cognitive function among older Chinese. Fixed-effect models show that widowhood has significant adverse effects on cognition for rural elders but not for urban ones. Furthermore, compared to rural men, rural women exhibit greater declines in cognition, especially in fluid cognition. We explore the possible mechanism from the neighborhood perspective. The results show that community sports and entertainment facilities and public services can effectively mitigate the negative impact of widowhood on cognitive function for rural widows. Sports and entertainment facilities can mainly enhance word recall ability, especially delayed word recall. Public services such as elderly health centers focusing on the healthcare function for the elderly can also improve the word recall ability of rural widows. On the other hand, family-based elderly care centers mainly increase the cognition ability of mental intactness.
Cryphodera guangdongensis n. sp. was collected from the soil and roots of Schima superba in Guangdong province, China. The new species is characterised by having a nearly spherical female, with dimensions of length × width = 532.3 (423.8–675.3) × 295.6 (160.0–381.2) μm, stylet length of 35.7 (31.1–42.1) μm, protruding vulval lips, a vulval slit measuring 54.2 (47.4–58.9) μm, an area between the vulva and anus that is flat to concave, and a vulva–anus distance 49.3 (41.1–57.6) μm. The male features two lip annules, a stylet length of 31.7 (27.4–34.8) μm and basal knobs that are slightly projecting anteriorly, while lateral field is areolated with three incisures and spicules length of 27.1 (23.7–31.0) μm. The second stage juvenile is characterised by a body length of 506.1 (441.8–564.4) μm long, two to three lip annules, a stylet length 31.2 (29.7–33.2) μm which is well developed, basal knobs projecting anteriorly, a lateral field that is areolate with three incisures, and a narrow rounded tail measuring 63.2 (54.2–71.3) μm long, with a hyaline region of 35.6 (27.4–56.6) μm long that is longer than the stylet. Based on morphology and morphometrics, the new species is closely related to C. sinensis and C. japonicum within the genus Cryphodera. The phylogenetic trees constructed based on the ITS-rRNA, 28S-rRNA D2–D3 region, and the partial COI gene sequences indicate that the new species clusters with other Cryphodera species but maintains in a separated subgroup. A key to the species of the genus Cryphodera is also provided in this study.
The incorporation of trace metals into land snail shells may record the ambient environmental conditions, yet this potential remains largely unexplored. In this study, we analyzed modern snail shells (Cathaica sp.) collected from 16 sites across the Chinese Loess Plateau to investigate their trace metal compositions. Our results show that both the Sr/Ca and Ba/Ca ratios exhibit minimal intra-shell variability and small inter-shell variability at individual sites. A significant positive correlation is observed between the shell Sr/Ca and Ba/Ca ratios across the plateau, with higher values being recorded in the northwestern sites where less monsoonal rainfall is received. We propose that shell Sr/Ca and Ba/Ca ratios, which record the composition of soil solution, may be controlled by the Rayleigh distillation in response to prior calcite precipitation. Higher rainfall amounts may lead to a lower degree of Rayleigh distillation and thus lower shell Sr/Ca and Ba/Ca ratios. This is supported by the distinct negative correlation between summer precipitation and shell Sr/Ca and Ba/Ca ratios, enabling us to reconstruct summer precipitation amounts using the Sr/Ca and Ba/Ca ratios of Cathaica sp. shells. The potential application of these novel proxies may also be promising for other terrestrial mollusks living in the loess deposits globally.
Methamphetamine (METH) dependence is a globally significant public health concern with no efficacious treatment. Trait impulsivity is associated with the initiation, maintenance, and recurrence of substance abuse. However, the presence of these associations in METH addiction, as well as the underlying neurobiological mechanisms, remains incompletely understood.
Methods
We scanned 110 individuals with METH use disorder (MUDs) and 55 matched healthy controls (HCs) using T1-weighted imaging and assessed their drug use characteristics and trait impulsivity. Surface-based morphometry and graph theoretical analysis were used to investigate group differences in brain morphometry and network attributes. Partial correlations were conducted to investigate the relationships between brain morphometric changes, drug use parameters, and trait impulsivity. Mediation analyses examined how trait impulsivity and drug craving influenced the link between brain morphometric change and MUD severity in patients.
Results
MUDs exhibited thinner thickness in the left fusiform gyrus and right pars opercularis, as well as diminished small-world properties in their structural covariance networks (SCNs) compared to HCs. Furthermore, reduced cortical thickness in the right pars opercularis was linked to motor impulsivity (MI) and MUD severity, and the association between the right pars opercularis thickness and MUD severity was significantly mediated by both MI and cue-induced craving.
Conclusions
These findings suggest that MUDs exhibit distinct brain structural abnormalities in both the cortical thickness and SCNs and highlight the critical role of impulse control in METH addiction. This insight may offer a potential neurobiological target for developing therapeutic interventions to treat addiction and prevent relapse.
The interaction of helminth infections with type 2 diabetes (T2D) has been a major area of research in the past few years. This paper, therefore, focuses on the systematic review of the effects of helminthic infections on metabolism and immune regulation related to T2D, with mechanisms through which both direct and indirect effects are mediated. Specifically, the possible therapeutic role of helminths in T2D management, probably mediated through the modulation of host metabolic pathways and immune responses, is of special interest. This paper discusses the current possibilities for translating helminth therapy from basic laboratory research to clinical application, as well as existing and future challenges. Although preliminary studies suggest the potential for helminth therapy for T2D patients, their safety and efficacy still need to be confirmed by larger-scale clinical studies.
A novel entomopathogenic nematode (EPN) species, Steinernema tarimense n. sp., was isolated from soil samples collected in a Populus euphratica forest located in Yuli County within the Tarim Basin of Xinjiang, China. Integrated morphological and molecular analyses consistently place S. tarimense n. sp. within the ‘kushidai-clade’. The infective juvenile (IJ) of new species is characterized by a body length of 674–1010 μm, excretory pore located 53–80 μm from anterior end, nerve ring positioned 85–131 μm from anterior end, pharynx base situated 111–162 μm from anterior end, a tail length of 41–56 μm, and the ratios D% = 42.0–66.6, E% = 116.2–184.4, and H% = 25.5–45.1. The first-generation male of the new species is characterized by a curved spicule length of 61–89 μm, gubernaculum length of 41–58 μm, and ratios D% = 36.8–66.2, SW% = 117.0–206.1, and GS% = 54.8–82.0. Additionally, the tail of first-generation female is conoid with a minute mucron. Phylogenetic analyses of ITS, 28S, and mt12S sequences demonstrated that the three isolates of S. tarimense n. sp. are conspecific and form a sister clade to members of the ‘kushidai-clade’ including S. akhursti, S. anantnagense, S. kushidai, and S. populi. Notably, the IJs of the new species exhibited faster development at 25°C compared to other Steinernema species. This represents the first described of an indigenous EPN species from Xinjiang, suggesting its potential as a novel biocontrol agent against local pests.
In this paper, we propose a novel online informative path planner for 3-D modeling of unknown structures using micro aerial vehicles. Different from the explore-then-exploit strategy, our planner can cope with exploration and coverage simultaneously and thus obtain complete and high-quality 3-D models. We first devise a set of evaluation metrics considering the perception constraints of the sensor for efficiently evaluating the coverage quality of the reconstructed surfaces. Then, the coverage quality is utilized to guide the subsequent informative path planning. Specifically, our hierarchical planner consists of two planning stages – a local coverage stage for inspecting surfaces with low coverage quality and a global exploration stage for transiting the robot to unexplored regions at the global scale. The local coverage stage computes the coverage path that takes into account both the exploration and coverage objectives based on the estimated coverage quality and frontiers, and the global exploration stage maintains a sparse roadmap in the explored space to achieve fast global exploration. We conduct both simulated and real-world experiments to validate the proposed method. The results show that our planner outperforms the state-of-the-art algorithms and especially decreases the reconstruction error (at least 12.5% lower on average).
The high comorbidity of major depressive disorder (MDD), anxiety disorders (ANX), and post-traumatic stress disorder (PTSD) complicates the study of their structural neural correlates, particularly in white matter (WM) alterations. Using fractional anisotropy (FA), this meta-analysis aimed to identify both unique and shared WM characteristics for these disorders by comparing them with healthy controls (HC). The aggregated sample size across studies includes 3,661 individuals diagnosed with MDD, ANX, or PTSD and 3,140 HC participants. The whole-brain analysis revealed significant FA reductions in the corpus callosum (CC) across MDD, ANX, and PTSD, suggesting a common neurostructural alteration underlying these disorders. Further pairwise comparisons highlighted disorder-specific differences: MDD patients showed reduced FA in the middle cerebellar peduncles and bilateral superior longitudinal fasciculus II relative to ANX patients and decreased FA in the CC extending to the left anterior thalamic projections (ATPs) when compared with PTSD. In contrast, PTSD patients exhibited reduced FA in the right ATPs compared to HC. No significant FA differences were observed between ANX and PTSD or between ANX and HC. These findings provide evidence for both shared and unique WM alterations in MDD, ANX, and PTSD, reflecting the neural underpinnings of the clinical characteristics that distinguish these disorders.
Previous studies have reported comorbidities of autoimmune thyroid disorders (AITD), including Hashimoto’s disease (HT) and Graves’ disease (GD), and celiac disease (CeD), as well as the possible beneficial effects of a gluten-free diet (GFD) on AITD. Nonetheless, it remains uncertain whether there is a genetic causal relationship between AITD and CeD, while the beneficial effects on a GFD are controversial. This study aim to explore the causal relationship between CeD and AITD, particularly with HT, and to determine whether a GFD is beneficial for AITD. We performed a two-sample Mendelian Randomization (MR) analysis on data from the largest meta-analysis summary statistics of AITD, CeD and GFD. Genetic instrumental variables were established by pinpointing single nucleotide polymorphisms (SNPs) that relate to corresponding factors. In assessing sensitivity and heterogeneity, we conducted examinations of MR Egger, weighted median, simple mode, weighted mode, and MR Egger intercept tests. HT was found to play a pathogenic role in increasing the risk of CeD (ORIVW = 1.544 [95%CI 1.153-2.068], p = 0.00355), and our Mendelian randomization study does not support genetic liability related to CeD with GD (Graves’ disease) and GFD with AITD. This study supports the positive correlation between HT risk and CeD risk, while GFD has no protective effect on AITD and may exert its effect through other mechanisms. These findings provide valuable insights into potential targets for disease intervention and treatment at the genetic level.
Non-spherical bubble collapses near solid boundaries, generating water hammer pressures and shock waves, were recognized as key mechanisms for cavitation erosion. However, there is no agreement on local erosion patterns, and cavitation erosion damage lacks quantitative analysis. In our experiments, five distinct local erosion patterns were identified on aluminium sample surfaces, resulting from the collapse of laser-induced cavitation bubbles at moderate stand-off distances of $0.4\leqslant \gamma \leqslant 2.2$, namely bipolar, monopolar, annular, solar-halo and central. Among them, the bipolar and monopolar patterns exhibit the most severe cavitation erosion when the toroidal bubbles undergo asymmetrical collapse along the circumferential direction during the second cycle. Shadowgraphy visualization revealed that asymmetrical collapse caused shockwave focusing through head-on collision and oblique superposition of wavefronts. This led to the variations in toroidal bubble radii and the positions of maximum erosion depth not matching at certain stand-off distances. Both initial plasma asymmetry and bubble–wall stand-off distance were critical in determining circumferential asymmetrical collapse behaviours. At large initial aspect ratios, the elliptical jet tips form during the contraction process, resulting in the toroidal bubble collapsing from regions with smaller curvature radii, ultimately converging to the colliding point along the circumferential direction. Our three-dimensional simulations using OpenFOAM successfully reproduce the key features of circumferentially asymmetrical bubble collapse. This study provides new insights into the non-spherical near-wall bubble collapse dynamics and provides a foundation for developing predictive models for cavitation erosion.
Existing evidence on the association between combined lifestyle and depressive symptoms is limited to the general population and is lacking in individuals with subthreshold depression, a high-risk group for depressive disorders. Furthermore, it remains unclear whether an overall healthy lifestyle can mitigate the association between childhood trauma (CT) and depressive symptoms, even in the general population. We aimed to explore the associations of combined lifestyle, and its interaction with CT, with depressive symptoms and their subtypes (i.e. cognitive-affective and somatic symptoms) among adults with subthreshold depression.
Methods
This dynamic cohort was initiated in Shenzhen, China in 2019, including adults aged 18–65 years with the Patient Health Questionnaire-9 (PHQ-9) score of ≥ 5 but not diagnosed with depressive disorders at baseline. CT (present or absent) was assessed with the Childhood Trauma Questionnaire-Short Form. Combined lifestyle, including no current drinking, no current smoking, regular physical exercise, optimal sleep duration and no obesity, was categorized into 0–2, 3 and 4–5 healthy lifestyles. Depressive symptoms were assessed using the PHQ-9 during follow-up. This cohort was followed every 6 months, and as of March 2023, had been followed for 3.5 years.
Findings
This study included 2298 participants (mean [SD] age, 40.3 [11.1] years; 37.7% male). After fully adjusting for confounders, compared with 0–2 healthy lifestyles, 3 (β coefficient, −0.619 [95% CI, −0.943, −0.294]) and 4–5 (β coefficient, −0.986 [95% CI, −1.302, −0.671]) healthy lifestyles were associated with milder depressive symptoms during follow-up. There exists a significant synergistic interaction between a healthy lifestyle and the absence of CT. The CT-stratified analysis showed that compared with 0–2 healthy lifestyles, 3 healthy lifestyles were associated with milder depressive symptoms in participants with CT, but not in those without CT, and 4–5 healthy lifestyles were associated with milder depressive symptoms in both participants with and without CT, with a stronger association in those with CT. The lifestyle-stratified analysis showed that CT was associated with more severe depressive symptoms in participants with 0–2 healthy lifestyles, but not in those with 3 or 4–5 healthy lifestyles. Cognitive-affective and somatic symptoms showed similar results.
Conclusions
In this 3.5-year longitudinal study of adults with subthreshold depression, an overall healthy lifestyle was associated with subsequent milder depressive symptoms and their subtypes, with a stronger association in adults with CT than those without CT. Moreover, an overall healthy lifestyle mitigated the association of CT with depressive symptoms and their subtypes.
This study explores whether DNA methylation (DNAm) mediates the association between lean body mass (LBM) and cognition, as well as whether LBM mediates the association between DNAm and cognition. Based on the data of 59 monozygotic twin pairs, mediation analyses were performed using causal inference test method and mediation analyses. Average causal mediation effect (ACME), average direct effect (ADE), and total effect (TE) were calculated. Among the CpGs associated with LBM, five located within PDGFRB and RP11 genes (ACME: −0.0972−0.0463, |ACME/ADE|: 10.44%−18.30%) negatively mediated the association between LBM and cognition, while one in the PAX2 gene (ACME: 0.3510, |ACME/TE|: 11.84%) positively mediated the association. Besides, the methylation risk score (MRS) of RP11 gene (ACME: −0.0517, |ACME/ADE|: 10.64%) and MRS of all CpGs (ACME: −0.0511, |ACME/ADE|: 10.53%) negatively mediated the association of LBM with cognition. For another, LBM negatively mediated the association between the DNAm level of one CpG within UBXN6 and cognition (ACME: −0.0732, |ACME/TE|: 20.78%), while positively mediated the association between the DNAm level of four CpGs within FOXI2 and cognition (ACME: 0.2812−0.4496, |ACME/TE|: 18.15%−27.29%). It was found the DNAm in PDGFRB, RP11 and PAX2 partially mediates the association between LBM and cognition, and the association between DNAm in UBXN6 and FOXI2 with cognition is also partially mediated by LBM.
This study investigated the factors influencing the mental health of rural doctors in Hebei Province, to provide a basis for improving the mental health of rural doctors and enhancing the level of primary health care.
Background:
The aim of this study was to understand the mental health of rural doctors in Hebei Province, identify the factors that influence it, and propose ways to improve their psychological status and the level of medical service of rural doctors.
Methods:
Rural doctors from 11 cities in Hebei Province were randomly selected, and their basic characteristics and mental health status were surveyed via a structured questionnaire and the Symptom Checklist-90 (SCL-90). The differences between the SCL-90 scores of rural doctors in Hebei Province and the Chinese population norm, as well as the proportion of doctors with mental health problems, were compared. Logistic regression was used to analyse the factors that affect the mental health of rural doctors.
Results:
A total of 2593 valid questionnaires were received. The results of the study revealed several findings: the younger the rural doctors, the greater the incidence of mental health problems (OR = 0.792); female rural doctors were more likely to experience mental health issues than their male counterparts (OR = 0.789); rural doctors with disabilities and chronic diseases faced a significantly greater risk of mental health problems compared to healthy rural doctors (OR = 2.268); rural doctors with longer working hours have a greater incidence of mental health problems; and rural doctors with higher education backgrounds have a higher prevalence of somatization (OR = 1.203).
Conclusion:
Rural doctors who are younger, male, have been in medical service longer, have a chronic illness or disability, and have a high degree of education are at greater risk of developing mental health problems. Attention should be given to the mental health of the rural doctor population to improve primary health care services.