Large Device Size Research Articles

A Review of Integrated Photonic Devices Using Sb2Se3

AbstractThe silicon photonic technology is a highly promising option for photonic integrated circuits and has attracted intensive interests, particularly since it can utilize complementary metal‐oxide‐semiconductor processing techniques and facilities, thereby realizing high‐density photonic integrations with low‐cost. Unfortunately, the thermo‐optic and the carrier dispersion effects, which are the typical means of tuning silicon photonics devices, bring the drawbacks of high power consumption and large device size due to the relatively weak effect with a small refractive index change and being volatile. For overcoming these drawbacks, phase‐change materials are introduced into silicon photonic devices, where VO2 and Ge2Sb2Te5 are the most commonly used ones. However, the key disadvantage of large loss resulting from them limits further improving the performances of integrated photonic devices. Therefore, Sb2Se3 has seen increasing interests recently in the design of silicon photonic integrated devices, benefiting from the advantages of having extremely low loss over the C‐band and being non‐volatile. In this paper, the trending recent studies about integrated optical devices are systematically reviewed using Sb2Se3, which are classified according to the device function.

Experimental investigation on the thermal performance of a large-size aluminum vapor chamber for multi-point heat sources

Abstract With the development of electronic information technology, the integration and power of electronic equipment continue to increase. As an efficient heat transfer element, vapor chambers are widely used in the field of heat dissipation of electronic devices. However, greater challenges have been posed in terms of higher heat dissipation capacity, larger size, and lighter weight. Therefore, a large-scale aluminum vapor chamber with a size of 340 mm×295 mm ×7.5 mm is designed for the heat dissipation of multi-point array heat sources. Multiple parallel porous ribs are sintered to form capillary wicking channels and vapor diffusion paths, which efficiently transfer the heat from the middle of the vapor chamber to the cold plate on the two sides. The transient working characteristics and heat dissipation performance under different working conditions are experimentally investigated. The results show that there is obvious temperature instability, which can be suppressed by the tilt of the vapor chamber and the increase of the heating power. Under the tilt condition, the temperature rises in the vertical direction due to the influence of gravity, while the inclination angle has basically no effect. The vapor chamber can work stably at the total heating power of 2100 W with the smallest thermal resistance 0.03 °C/W. The single-point heat flux can reach 7.3W/cm2 for the 128 heat sources. Compared to a traditional vapor chamber, the proposed aluminum vapor chamber provides a thermal management solution for large-size electronic devices with multiple heat sources.

Transjugular Transcatheter Tricuspid Valve Replacement: Early Compassionate Use Outcomes

BackgroundData on procedural and early outcomes after transjugular transcatheter tricuspid valve replacement (TTVR) are limited. ObjectivesThis study sought to evaluate first-in-man procedural and clinical outcomes after transjugular TTVR with a special focus on patients who received large device sizes in whom TTVR outcomes have been questioned. MethodsThe retrospective registry included patients who underwent TTVR using the LuX-Valve Plus system (Jenscare Biotechnology Co Ltd) for symptomatic tricuspid regurgitation (TR) from January 2022 until February 2024 at 15 international centers in a compassionate use setting. The endpoints were procedural TR reduction, in-hospital death, adverse events, and 1-month survival. We further stratified results according to the size of the implanted device (<55 vs ≥55 mm). ResultsThe registry included a total of 76 patients at a median age of 78 years (Q1-Q3: 72-83 years, 47.4% women). TR was reduced to ≤2+ and ≤1+ in 94.7% and 90.8% of patients (75.0% of patients received TTVR devices ≥55 mm) with well-sustained results at 1-month follow-up (TR ≤2+ in 95.0% and ≤1+ 86.8%). Residual TR was paravalvular in all cases. In-hospital death occurred in 4 patients (5.3%). Four patients (5.3%) underwent cardiac surgery during index hospitalization. Major in-hospital bleeding events occurred in 5 patients (6.6%). New in-hospital pacemaker implantation was required in 3.9% of patients in the overall cohort (5.7% in “pacemaker-naive” individuals). No cases of valve thrombosis, stroke, myocardial infarction, or pulmonary embolism were observed. At 1-month follow-up, survival was 94.4%, and NYHA functional class significantly improved. One further patient received a pacemaker, 1 further bleeding event occurred, and 2 patients underwent reintervention or surgery within the first 30 days after TTVR. No differences in procedural outcomes or adverse events were observed after stratification for valve size. ConclusionsTransjugular TTVR appears to be a safe and effective treatment option for patients with severe TR with comparable outcomes in very large tricuspid anatomies.

Coated boron layers by boronization and a real-time boron coating using an impurity powder dropper in the LHD

In the Large Helical Device (LHD), diborane (B2H6) is used as a standard boron source for boronization, which is assisted by helium glow discharges. In 2019, a new Impurity Powder Dropper (IPD) system was installed and is under evaluation as a real-time wall conditioning technique. In the LHD, which is a large-sized heliotron device, an additional helium (He) glow discharge cleaning (GDC) after boronization was operated for a reduction in hydrogen recycling from the coated boron layers. This operational time of 3 h was determined by spectroscopic data during glow discharges. A flat hydrogen profile is obtained on the top surface of the coated boron on the specimen exposed to boronization. The results suggest a reduction in hydrogen at the top surface by He-GDC. Trapped oxygen in coated boron was obtained by boronization, and the coated boron, which has boron-oxide, on the first wall by B-IPD was also shown. Considering the difference in coating areas between B2H6 boronization and B-IPD operation, it would be most effective to use the IPD and B2H6 boronization coating together for optimized wall conditioning.

An electro-optic half subtractor from a silicon-based hybrid surface plasmon polariton waveguide

Abstract In order to solve the problems of low transmission rate and large device size of electro-optical modulator, an electro-optic half subtractor based on silicon-based hybrid surface plasmon polariton waveguide is proposed in this study. The proposed device utilizes three units metal-oxide-semiconductor capacitor structure to achieve the half subtractor logic function of electro-optic control, improving the transmission rate of the electro-optic half subtractor while also reducing the device size using surface plasmon polariton technology, with a size of only 32 μm × 4.3 μm. At the same time, the use of hybrid silicon waveguides reduces the sharp Ohmic attenuation caused by surface plasmon polaritons and reduces optical insertion losses (ILs). The simulation results show that when the electro-optic half subtractor operates at the wavelength of 1,550 nm, the IL difference is 1.0 dB in each state, the transmission rate of the device is 0.75 Tbit/s, and the energy consumption is 12.69 fj/bit.

The role of size and inertia on the hydrodynamics of a self-reacting heave single point absorber wave energy converter

We propose a detailed numerical study of a self-reacting floating point absorber, resembling the Ocean Power Technologies device PB3 PowerBuoy, for a possible installation in the Adriatic Sea. A simplified model of the mentioned device, composed of a floater sliding along a reacting body, which supports the floater, is studied, reproducing and analysing the most complex nonlinear phenomena, such as the wave overtopping and the out-of-water motion of the floater. Three different sizes of the device have been simulated, each with three different masses of the floater, deriving the time evolution of the wave in the surrounding of the floater, its frequency dispersion and energy content, the generated exciting force, the wave overtopping over the floater, and the out-of-water motion of the floater. The results highlight that the linear response is favoured by small floater density and optimal floater thickness. Additionally, large-sized devices are characterized by linear, but dissipative, response, while the response of medium-sized devices is only apparently linear.

Incidence and temporal evolution of delayed peridevice leak after left atrial appendage closure

BackgroundPeridevice leak (PDL) after left atrial appendage closure (LAAC) portends adverse outcomes. ObjectiveThe purpose of this study was to assess the incidence, predictors, clinical implications, and temporal evolution of PDL after LAAC. MethodsThis single-center retrospective study included all patients who underwent LAAC with Watchman FLX and had no PDL detected at the time of implantation. The primary end point was the incidence of new PDL at initial imaging. The composite secondary end point included continued oral anticoagulation after initial imaging, device-related thrombus, stroke or transient ischemic attack, major bleeding, and need for PDL closure at longest follow-up. Temporal evolution of PDL was assessed in patients with available surveillance imaging. ResultsOf the 355 patients who completed imaging at 47 days (interquartile range [IQR] 44–50 days), 139 (39%) had new PDL with a mean leak size of 3.2 ± 1.4 mm (median 3.0 mm; IQR 2.0–4.0 mm; range 1.0–9.0 mm). Multiple deployment attempts and larger device size were positive predictors of PDL, while increased contrast volume administration was a negative predictor of PDL. The composite secondary end point occurred in 42 (30%) patients with PDL and 33 (15%) patients without PDL (P < .001). Of the 139 patients with PDL, 43 (31%) had surveillance imaging where the leak size regressed from 3.7 ± 1.8 mm at 46 days (IQR 44–51 days) to 1.7 ± 2.0 mm at 189 days (IQR 158–285 days) (P < .001). The leak size regressed in 33 (77%), remained stable in 4 (9%), and progressed in 6 (14%) cases. ConclusionDespite design improvements, LAAC with Watchman FLX demonstrates a significant incidence of PDL with meaningful clinical implications. Regardless of initial size, most leaks regressed over time.

Rational Design of a Surface Acoustic Wave Device for Wearable Body Temperature Monitoring.

Continuous monitoring of vital signs based on advanced sensing technologies has attracted extensive attention due to the ravages of COVID-19. A maintenance-free and low-cost passive wireless sensing system based on surface acoustic wave (SAW) device can be used to continuously monitor temperature. However, the current SAW-based passive sensing system is mostly designed at a low frequency around 433 MHz, which leads to the relatively large size of SAW devices and antenna, hindering their application in wearable devices. In this paper, SAW devices with a resonant frequency distributed in the 870 MHz to 960 MHz range are rationally designed and fabricated. Based on the finite-element method (FEM) and coupling-of-modes (COM) model, the device parameters, including interdigital transducer (IDT) pairs, aperture size, and reflector pairs, are systematically optimized, and the theoretical and experimental results show high consistency. Finally, SAW temperature sensors with a quality factor greater than 2200 are obtained for real-time temperature monitoring ranging from 20 to 50 °C. Benefitting from the higher operating frequency, the size of the sensing system can be reduced for human body temperature monitoring, showing its potential to be used as a wearable monitoring device in the future.

Optical bistability and flip-flop function in feedback Fano laser.

Optical bistability has the potential to emulate the capabilities of electrical flip-flops, offering plenty of applications in optical signal processing. Conventional optical bistable devices operate by altering the susceptibility of a nonlinear medium. This method, however, often results in drawbacks such as large device size, high energy consumption, or long switching times. This work proposes an optical bistable device incorporating strong optical feedback into a Fano laser. This leads to multiple stable states and introduces a region of bistability between the inherent Fano mode and a feedback-induced Fabry-Perot mode. Unlike conventional bistable devices, the Fano system exploits strong field localization in a nanocavity to control the properties of one of the laser mirrors. This configuration means that switching states can be achieved by modulating the mirror's loss rather than changing the susceptibility of the active medium. Importantly, modulation can be implemented locally on a nanocavity, bypassing the need to adjust the entire laser system. This leads to fast flip-flop actions with low energy consumption. The feedback Fano laser can be embodied in a compact microscopic structure, thus providing a promising approach towards integrated all-optical computation and on-chip signal processing.

Monolayer Chiral Metasurface for Generation of Arbitrary Cylindrical Vector Beams

The cylindrical vector beam (CVB) has been widely studied and applied in recent years. However, many CVB generation methods suffer from complex systems, and large-size devices are required. Here, we propose a monolayer chiral metasurface composed of spin-sensitive unit cells which can generate different holograms for left- and right-circular polarization based on the combined modulation of geometric phase and detour phase. With a linearly polarized incident beam, the metasurface can generate CVBs with controllable polarization angles and orders, and even more complex vector beams. This work provides a new idea for the design of miniaturized optical devices for generating arbitrary vector beams.

Cardiac troponin I release after transcatheter closure of atrial septal defects is associated with supraventricular arrhythmias on early follow-up.

Atrial septal defects (ASD) are prevalent congenital heart anomalies found in the adult population. Percutaneous ASD closure has become a routine clinical practice. Elevation of postprocedural transient cardiac biomarkers and exacerbation of supraventricular arrhythmias have been reported in the subject literature. To explore the relationship between cardiac troponin I (cTnI) elevation and supraventricular ectopy (SVE) following percutaneous closure of secundum atrial septal defect (ASD) in adult patients. 600 consecutive patients who underwent successful transcatheter ASD secundum closure were analyzed. Serum levels of cTnI were measured before and within 72 h of device implantation. 24-hour Holter monitoring was performed before the procedure, at 1 month, and at 6 months of follow-up. SVE burden increased 1 month after the procedure (median 1021.00; min.-max. 11.00-29 862.00) compared to baseline values (median 146.00; min.-max. 0-1865.00; p < 0.01). 61.7% of patients demonstrated a cTnI rise exceeding 50% of the upper reference limit within 24 h of the procedure. A statistically significant positive correlation between SVE burden 1 month after the procedure and periprocedural cTnI increase (p < 0.05, r = 0.41) was observed, while cTnI levels significantly correlated with procedure and fluoroscopy time (p < 0.001), device size (p < 0.001) and maximal ASD diameter (p < 0.001). A significant increase of cTnI is noted frequently after transcatheter ASD closure and seems to predict exacerbation in SVE burden on short-term follow up. The independent risk factors of cTnI rise are prolonged procedure duration and larger device sizes.

Dependence of the uniformity of feed mixing in the feed mixing device of the granulation line on the number of paddle shaft revolutions and mixing time

Today, 87 percent of the number of cattle, as well as 90 percent of the number of sheep and goats in Uzbekistan are cared for by farmers. 85-90 percent of the number of livestock in our Republic belongs to peasant farms, and the preparation of feed for the livestock kept in these peasant farms should be implemented using best practices and modern technologies in developed countries, increasing the competitiveness and economic efficiency of the livestock sector is important. Based on the aforementioned information, a small-sized granulation line and a feed mixing device were created that are comparable to large-sized devices in terms of work quality and meet small livestock and poultry farms in terms of size, productivity, and energy consumption. The homogeneity of the feed mixing ratio in relation to the device’s paddle shaft rotation count and mixing duration was investigated through experimentation. The results of the trials showed that when the feed mixer paddle rotor was turning at a speed of 50 revolutions per minute and the mixing period was set for five minutes, the optimal mixing quality of ground wheat grain, ground maize grain, ground rice, and wheat bran for the manufacturing of granular feed was reached.

Biomedical application of terahertz imaging technology: a narrative review.

Terahertz (THz) imaging has wide applications in biomedical research due to its properties, such as non-ionizing, non-invasive and distinctive spectral fingerprints. Over the past 6 years, the application of THz imaging in tumor tissue has made encouraging progress. However, due to the strong absorption of THz by water, the large size, high cost, and low sensitivity of THz devices, it is still difficult to be widely used in clinical practice. This paper provides ideas for researchers and promotes the development of THz imaging in clinical research. The literature search was conducted in the Web of Science and PubMed databases using the keywords "Terahertz imaging", "Breast", "Brain", "Skin" and "Cancer". A total of 94 English language articles from 1 January, 2017 to 30 December, 2022 were reviewed. In this review, we briefly introduced the recent advances in THz near-field imaging, single-pixel imaging and real-time imaging, the applications of THz imaging for detecting breast, brain and skin tissues in the last 6 years were reviewed, and the advantages and existing challenges were identified. It is necessary to combine machine learning and metamaterials to develop real-time THz devices with small size, low cost and high sensitivity that can be widely used in clinical practice. More powerful THz detectors can be developed by combining graphene, designing structures and other methods to improve the sensitivity of the devices and obtain more accurate information. Establishing a THz database is one of the important methods to improve the repeatability and accuracy of imaging results. THz technology is an effective method for tumor imaging. We believe that with the joint efforts of researchers and clinicians, accurate, real-time, and safe THz imaging will be widely applied in clinical practice in the future.

Design and frequency control study of small-sized magnetorheological finishing device applied in optical manufacturing

With the continuous development of various advanced optical systems, there is an increasing demand for optical components with small apertures (generally ranging from a few millimeters to tens of millimeters in diameter), steep slopes, or even specific relief structures on their surfaces (such as continuous phase elements). These optical components all require high surface quality and shape accuracy. However, existing magnetorheological finishing (MRF) devices have larger dimensions, and the obtained removal function size is relatively larger than the size of small-diameter optical components, making it difficult to achieve high surface shape accuracy after processing. To achieve high-precision machining of small-aperture optical components and obtain higher frequency control capabilities, this study first designed and optimized a small-size MRF device with a 13 mm polishing wheel. Based on theoretical and finite element simulation analyses, the magnetic pole structure of the small-size MRF device was designed. The orthogonal experimental method was used to optimize the key parameters of the magnetic pole according to the magnetic field design requirements, and the device was constructed. Its performance and stability were experimentally analyzed, and the results showed that the peak magnetic field intensity in the polishing area of the device was about 230mT, which met the polishing requirements, and both its long-term and short-term processing stabilities met the design requirements. In addition, different sizes of removal functions were analyzed for frequency control ability, and theoretical and spectral analyses of the removal function indicated that the small-size removal function had better low-frequency error correction ability, while for mid-frequency band and mid-frequency ripple error, the opposite was true. The experimental results showed that when the optical component was shaped by 20 %, the low-frequency convergence capability of the 100 mm polishing device was only 18.72 %, much lower than that of the 13 mm polishing device, which was 52.51 %.Moreover, the mid-frequency ripple spectrum amplitude for the 13 mm polishing device was more than 15 times higher than that for the 100 mm polishing device when removing 50 nm material, and the mid-frequency root mean square (RMS) increased significantly, deteriorating the surface mid-frequency error of the optical component. Therefore, when performing magnetorheological polishing on an optical component surface, a process of using large-size MRF devices for roughing combined with small-size MRF devices for finishing can ensure machining efficiency while controlling low-frequency and mid-frequency errors well. This study provides theoretical support for the magnetic pole design of MRF devices and broadens the frequency spectrum correction ability and application range of MRF processes, which has great application value.

Incidence of Atrial Fibrillation or Arrhythmias After Patent Foramen Ovale Closure

BackgroundPatients with a patent foramen ovale (PFO) who undergo percutaneous PFO closure are at a greater risk of developing atrial fibrillation (AF) compared with patients whose PFOs are managed medically. Postclosure AF appears to be well tolerated if treated but may increase the risk for stroke. Postclosure AF is reported to occur in 3.7% to 7.4% of patients; however, incidence across devices remains uncertain. This study aims to evaluate the frequency of postclosure AF, atrial flutter, and arrhythmias in 6 PFO closure devices. MethodsFour hundred forty-five patients underwent percutaneous PFO closure with appropriate follow-up between 2001 and 2021. The procedure was performed using Abbott Amplatzer PFO, Amplatzer ASD, Amplatzer Cribriform, NMT CardioSEAL, Gore Helex, or Gore Cardioform devices. Incidence of AF, atrial flutter, and arrhythmias were assessed by electrocardiogram within 6 months from closure. Multivariate logistic regression evaluated potential predictors of postclosure AF or atrial flutter. ResultsPostclosure AF or atrial flutter occurred in 30 patients (6.7%) within 6 months, and its incidence was significantly different across devices. Gore Cardioform had the greatest frequency of postclosure AF or atrial flutter events (16.8%) compared with other devices. The Gore Cardioform device, larger device sizes, and male sex were associated with greater risk of postclosure AF or atrial flutter. ConclusionsPostclosure AF or atrial flutter was more likely to occur in the Gore Cardioform device, in males, and in patients who underwent PFO closure with larger devices. Although it is more effective for complete closure, the Gore Cardioform device was shown to be an independent predictor of postclosure AF or atrial flutter.

Impact of age and body mass index (BMI) on the short-term prognosis of Impella in patients with cardiogenic shock

Abstract Introduction The percutaneous transcatheter left ventricular assist device, Impella, has been recently introduced in Japan for patients with drug refractory acute heart failure including cardiogenic shock (CGS). Despite its potential benefits, Impella is associated with certain limitations, including a large device size and an increased risk of complications such as bleeding, hemolysis, and renal failure. These factors may present challenges for the use of Impella in elderly patients and those with smaller body size. For elderly patients with various comorbidities, the clinical impact of invasive hemodynamic support with impella remains unclear. Objective To assess the impact of age and body mass index (BMI) on the survival of patients with CGS treated with Impella. Methods We retrospectively reviewed 133 consecutive patients, who received Impella for cardiogenic shock, including cardiac arrest, between September 2018 and January 2023 at our institute. Patients were divided into two distinct age groups: younger group (&amp;lt;75 years of age; n=59) and elderly group (≥75 years; n=74). We assessed rate of successful Impella weaning and the 30-day survival. Multivariate cox regression analysis was used to identify risk factors for 30-day all-cause mortality. Results Baseline patient characteristics demonstrated a mean age of 70 ±13 years with 71% male ratio. Acute coronary syndrome was diagnosed in 72% of patients, while 63% received concomitant venoarterial extracorporeal membrane oxygenation (VA-ECMO), called ECPELLA, and 41% underwent extracorporeal cardiopulmonary resuscitation (E-CPR). The elderly group exhibited a lower BMI and higher rates of comorbidities, such as hypertension and chronic kidney disease. Notably, the incidence of cardiac arrest, E-CPR, and concomitant use of VA-ECMO were significantly lower in the elderly group compared with the younger group. There were no significant differences in Impella weaning, support duration, and length of hospital stay among two groups. Kaplan-Meier analysis revealed that the 30-day survival was also similar between two groups. Univariable Cox regression analysis revealed that BMI was significantly associated with 30-day mortality along with E-CPR and the combined use of VA-ECMO. Multivariable Cox regression analysis including the age, male, BMI, E-CPR, and combined use of VA-ECMO showed that the predictive values of independent determinants for 30-day mortality were age (hazard ratio [HR] 1.05, 95% confidence interval [CI], 1.02-1.07, P&amp;lt;0.0001), BMI (HR 1.14, 95%CI, 1.06-1.21, P=0.0001), and VA-ECMO (HR 4.27, 95% CI, 1.92-9.50, P=0.0004). Conclusion Results suggest that age and BMI were significantly associated with increased 30-day mortality risk, indicating a counterintuitive relationship between BMI and mortality in this population.OutcomesMultivariate Cox Regression

First-ever satellite tracking of Black Terns (Chlidonias niger): Insights into home range and habitat selection.

Understanding animal movement across the annual cycle is critical for developing appropriate conservation plans, but the large size and high cost of tracking devices can limit the spatial and temporal resolution at which movement data can be collected, especially for small avian species. Furthermore, for species with low breeding site fidelity, the ability to obtain tracking data from small, archival tags is hindered by low recapture rates. We deployed satellite tracking devices on four adult Black Terns (Chlidonias niger), a declining waterbird with low site fidelity, to examine space use and selection of resources within individual breeding home ranges. We also provide a preliminary assessment of habitat use during fall stopover. We found that home ranges were extensive (mean 283.7 km2) and distances travelled from the nest substantially larger (up to 35 km) than previously thought (~2.5 km). Terns showed selection for wetlands and open water on the breeding grounds, but also showed selection for developed areas. This may reflect humans selecting similar landscape features for recreation and development as terns, and suggests that terns can tolerate the light degree of development (e.g. cottages, boat launches, etc.) within our study area. Despite a small sample size, this is the first study to track individual Black Terns at a high resolution with implications for conservation and wetland management practices relevant to the spatial scales at which habitat is used by the species.

Intelligent Computation Offloading and Resource Allocation in IIoT With End-Edge-Cloud Computing Using NSGA-III

The Industrial Internet of things (IIoT), which consists of massive IoT devices and wireless access points in industrial infrastructures to acquire intelligent services, has been considered as a vital physical information platform for implementing Industry 4.0. Further, mobile edge computing (MEC) has brought an opportunity to accelerate the development of IIoT. However, the existing MEC methods may not be directly used for IIoT scenarios due to the large size of IIoT devices and the characteristics of the applications, as well as the limited and heterogeneous resources of edge servers. In view of this, the computation offloading and resource allocation are formulated as a multi-objective optimization problem, and an end-edge-cloud collaborative intelligent optimization method is devised in this paper. Comprehensive experiments and evaluations are carried out to prove the effectiveness and efficiency of our proposed method with regard to the energy consumption and time consumption of IIoT devices, as well as resource utilization and load balancing of edge servers.

Mate-guarding success depends on male investment in a butterfly.

Males of many insects, including butterflies, produce mate-guarding devices, such as mating plugs, to prolong guarding and prevent future female matings in the male's absence. In a few butterflies, large external mate-guarding devices, that is, sphragides, occur. Gór et al. (Behaviour, 160, 2023 and 515-557) found conspicuously large size and morphological variation of mate-guarding devices within a single population of the potentially polyandrous Clouded Apollo (Parnassius mnemosyne, L.) butterfly. They termed the externally visible male-produced devices as Copulatory opening APpendices (CAP) consisting of small devices, termed small CAPs and the much larger shield (i.e. sphragis). Our aim was to reveal CAP replacement dynamics within females during their lifetime and to understand how male investment into small CAPs or shields was (i) related to CAP persistence on the female, that is securing paternity, (ii) associated with female quality, measured as size and (iii) with actual adult sex ratio. We investigated a univoltine Clouded Apollo population to estimate CAP replacement risks, using multistate survival models, in an extensive observational study through 6 years based on mark-recapture. Shields were the most frequent mate-guarding devices and were more persistent than small CAPs, often lasting for life, excluding future matings. Thus, most females bearing a shield were deprived of postcopulatory female choice, and the genetic variance in their offspring could be reduced compared to those bearing small CAPs, thus mating more often. The ratio of shields to all CAPs gradually decreased towards the end of the flight period. Males were more prone to produce a shield when mating females with wider thoraces and when the ratio of males (i.e. competition) was higher in the population. To our best knowledge, this is the first quantitative study to investigate potential factors on which male investment in mate-guarding devices may depend, and how the variation in these devices impacts CAP persistence on females.

Human Action Recognition Based on Skeleton Information and Multi-Feature Fusion

Action assessment and feedback can effectively assist fitness practitioners in improving exercise benefits. In this paper, we address key challenges in human action recognition and assessment by proposing innovative methods that enhance performance while reducing computational complexity. Firstly, we present Oct-MobileNet, a lightweight backbone network, to overcome the limitations of the traditional OpenPose algorithm’s VGG19 network, which exhibits a large parameter size and high device requirements. Oct-MobileNet employs octave convolution and attention mechanisms to improve the extraction of high-frequency features from the human body contour, resulting in enhanced accuracy with reduced model computational burden. Furthermore, we introduce a novel approach for action recognition that combines skeleton-based information and multiple feature fusion. By extracting spatial geometric and temporal characteristics from actions, we employ a sliding window algorithm to integrate these features. Experimental results show the effectiveness of our approach, demonstrating its ability to accurately recognize and classify various human actions. Additionally, we address the evaluation of traditional fitness exercises, specifically focusing on the BaDunJin movements. We propose a multimodal information-based assessment method that combines pose detection and keypoint analysis. Label sequences are obtained through a pose detector and each frame’s keypoint coordinates are represented as pose vectors. Leveraging multimodal information, including label sequences and pose vectors, we explore action similarity and perform quantitative evaluations to help exercisers assess the quality of their exercise performance.