bluuebunny/crossref_metadata_2025 huggingface dataset:
Grapevine Branch Recognition and Pruning Point Localization Technology Based on Image Processing
Authors: Chen Zhangnan , Wang Yaxiong , Tong Siyuan , Chen Chongchong , Kang Feng
Published: April 2024

The identification of branches and bud points is the key to intelligent pruning of dormant grapevine branches and precise positioning of the pruning point on the branch is an important prerequisite for robotic arm pruning. This study takes Cabernet Sauvignon wine grapes as the experimental object and proposes a depth image-based pruning point localization algorithm based on pruning rules. In order to solve the problem of bud recognition in complex backgrounds, this study adopts a detection method that combines semantic segmentation and target detection. Firstly, the semantic segmentation algorithm PSP-net is used to separate the branches and the main stem from the background and the separated image undergoes two kinds of processing: one is to skeletonize it using the Zhang–Suen thinning algorithm and the other is to identify the buds and obtain the center coordinates of the buds using the target-detection method YOLOv5; finally, combining with the depth information of the depth image, we use the coordinates of the buds to determine the location of the pruning point located on the skeleton image. The results show that PSP-net has better results in segmentation performance with mIoU reaching 83.73%. YOLOv5 performs better in target detection with mAP reaching 81.06% and F1 reaching 0.80. The accuracy of this method in determining the location of pruning points reaches 82.35%. It can provide a method for fruit tree pruning robots to determine the location of pruning points.
Microbiomes of Primary Soils and Mining Heaps of Polymetallic Ore Quarries
Authors: Dorogaya Ekaterina , Abakumov Evgeny , Zverev Aleksei , Novikova Evgenia , Garshin Mikhail , Minnegaliev Aleksandr , Suleymanov Ruslan
Published: April 2024

This research evaluates the development of microbiomes in primary soils, forming in various mining dumps in the arid terrain in the Republic of Bashkortostan, Russia. A metagenomic analysis of the communities was performed by sequencing extended gene sequences. The evaluation of the agro-chemical properties was in accordance with conventional pedology methods. Inverse voltammetry was used to measure the heavy metals (lead, cadmium, mercury, zinc, copper, and nickel) and arsenic content. In all the samples studied, Actinobacteria and Proteobacteria phylas dominated, and, in smaller numbers, Acidobacteria and Bacteroidetes were present. In the natural samples, the proportion of Actinobacteria was higher, and the proportions of Proteobacteria and Bacteroidetes were lower than in the samples from anthropogenically disrupted soils. Verrucomicrobia bacteria and Thaumarchaeota archaea were not found in the forming soils of the Kulyurtau and Tubinsky quarries, although in all other samples, there was a significant content of representatives of these types. Soil formation was observed at the Kulyurtau and Tubinsky mines, with a self-restoration period of more than 30 years. The microbial communities of the forming soils were similar in species richness to the background soils, and the alpha diversity showed a high level of dispersion, although the beta diversity had a different clustering, but the absence of Verrucomicrobia and Thaumarchaeota phyla in the samples from both sites indicates the underdevelopment of new soils compared with the natural background. Agrochemical indicators showed a dependence on the type of growing vegetation and the degree of anthropogenic load, and the correlation with the microbial composition of soils was traced poorly.
Aiding Automated Shuttles with Their Driving Tasks as an On-Board Operator: A Case Study on Different Automated Driving Systems in Three Living Labs
Authors: Schrank Andreas , Kettwich Carmen , Oehl Michael
Published: April 2024

Highly automated shuttle vehicles (SAE Level 4) have the potential to enhance public transport services by decreasing the demand for drivers, enabling more frequent and flexible ride options. However, at least in a transitionary phase, safety operators that supervise and support the shuttles with their driving tasks may be required on board the vehicle from a technical or legal point of view. A crucial component for executing supervisory and intervening tasks is the human–machine interface between an automated vehicle and its on-board operator. This research presents in-depth case studies from three heterogenous living laboratories in Germany that deployed highly automated shuttle vehicles with on-board operators on public roads. The living labs differed significantly regarding the on-board operators’ tasks and the design of the human–machine interfaces. Originally considered a provisional solution until the vehicle automation is fully capable of running without human support, these interfaces were, in general, not designed in a user-centered way. However, since technological progress has been slower than expected, on-board operator interfaces are likely to persist in the mid-term at least. Hence, this research aims to assess the aptitude of interfaces that are in practical use for the on-board operators’ tasks, in order to determine the user-centered design of future interfaces. Completing questionnaires and undergoing comprehensive, semi-structured interviews, nine on-board operators evaluated their human–machine interfaces in light of the respective tasks they complete regarding user variables such as work context, acceptance, system transparency, and trust. The results were highly diverse across laboratories and underlined that the concrete system setup, encompassing task and interface design, has a considerable impact on these variables. Ergonomics, physical demand, and system transparency were identified as the most significant deficits. These findings and derived recommendations may inform the design of on-board operator workspaces, and bear implications for remote operation workstations as well.
The Application of the Bidiagonal Factorization of Totally Positive Matrices in Numerical Linear Algebra
Authors: Martínez José-Javier
Published: April 2024

The approach to solving linear systems with structured matrices by means of the bidiagonal factorization of the inverse of the coefficient matrix is first considered in this review article, the starting point being the classical Björck–Pereyra algorithms for Vandermonde systems, published in 1970 and carefully analyzed by Higham in 1987. The work of Higham briefly considered the role of total positivity in obtaining accurate results, which led to the generalization of this approach to totally positive Cauchy, Cauchy–Vandermonde and generalized Vandermonde matrices. Then, the solution of other linear algebra problems (eigenvalue and singular value computation, least squares problems) is addressed, a fundamental tool being the bidiagonal decomposition of the corresponding matrices. This bidiagonal decomposition is related to the theory of Neville elimination, although for achieving high relative accuracy the algorithm of Neville elimination is not used. Numerical experiments showing the good behavior of these algorithms when compared with algorithms that ignore the matrix structure are also included.
Controlling Algorithm of Reconfigurable Battery for State of Charge Balancing Using Amortized Q-Learning
Authors: Karnehm Dominic , Bliemetsrieder Wolfgang , Pohlmann Sebastian , Neve Antje
Published: April 2024

In the context of the electrification of the mobility sector, smart algorithms have to be developed to control battery packs. Smart and reconfigurable batteries are a promising alternative to conventional battery packs and offer new possibilities for operation and condition monitoring. This work proposes a reinforcement learning (RL) algorithm to balance the State of Charge (SoC) of reconfigurable batteries based on the topologies half-bridge and battery modular multilevel management (BM3). As an RL algorithm, Amortized Q-learning (AQL) is implemented, which enables the control of enormous numbers of possible configurations of the reconfigurable battery as well as the combination of classical controlling approaches and machine learning methods. This enhances the safety mechanisms during control. As a neural network of the AQL, a Feedforward Neuronal Network (FNN) is implemented consisting of three hidden layers. The experimental evaluation using a 12-cell hybrid cascaded multilevel converter illustrates the applicability of the method to balance the SoC and maintain the balanced state during discharge. The evaluation shows a 20.3% slower balancing process compared to a conventional approach. Nevertheless, AQL shows great potential for multiobjective optimizations and can be applied as an RL algorithm for control in power electronics.
Primary Stability of Implants Inserted into Polyurethane Blocks: Micro-CT and Analysis In Vitro
Authors: Dura Haddad Chadi , Andreatti Ludovica , Zelezetsky Igor , Porrelli Davide , Turco Gianluca , Bevilacqua Lorenzo , Maglione Michele
Published: April 2024

The approach employed for the site preparation of the dental implant is a variable factor that affects the implant’s primary stability and its ability to integrate with the surrounding bone. The main objective of this in vitro study is to evaluate the influence of different techniques used to prepare the implant site on the primary stability of the implant in two different densities of artificial bone. Materials and Methods: A total of 150 implant sites were prepared in rigid polyurethane blocks to simulate two distinct bone densities of 15 pounds per cubic foot (PCF) and 30 PCF, with a 1-mm-thick simulated cortex. The implant sites were equally distributed among piezoelectric surgery (PES), traditional drills (TD), and black ruby magnetic mallet inserts (MM). Two methods have been employed to evaluate the implant’s primary stability, Osstell and micro-tomography. Results: In the present study, we observed significant variations in the implant stability quotient (ISQ) values. More precisely, our findings indicate that the ISQ values were generally higher for 30 PCF compared to 15 PCF. In terms of the preparation technique, PES exhibited the greatest ISQ values, followed by MM, and finally TD. These findings corresponded for both bone densities of 30 PCF (PES 75.6 ± 1.73, MM 69.8 ± 1.91, and TD 65.8 ± 1.91) and 15 PCF (PES 72.3 ± 1.63, MM 62.4 ± 1.77, and TD 60.6 ± 1.81). By utilizing Micro-CT scans, we were able to determine the ratio of the implant occupation to the preparation site. Furthermore, we could calculate the maximum distance between the implant and the wall of the preparation site. The findings demonstrated that PES had a higher ratio of implant to preparation site occupation, followed by TD, and then the MM, at a bone density of 30 PCF (PES 96 ± 1.95, TD 94 ± 1.88, and MM 90.3 ± 2.11). Nevertheless, there were no statistically significant differences in the occupation ratio among these three approaches in the bone density of 15 PCF (PES 89.6 ± 1.22, TD 90 ± 1.31, and MM 88.4 ± 1.17). Regarding the maximum gap between the implant and the site preparation, the smallest gaps were seen when TD were used, followed by MM, and finally by PES, either in a bone density 15 PCF (PES 318 ± 21, TD 238 ± 17, and MM 301 ± 20 μm) or in a bone density 30 PCF (PES 299 ± 20, TD 221 ± 16, and MM 281 ± 19 μm). A statistical analysis using ANOVA revealed these differences to be significant, with p-values of < 0.05. Conclusion: The outcomes of this study indicate that employing the PES technique and osteo-densification with MM during implant insertion may enhance the primary stability and increase the possibility of early implant loading.
Photorefraction Simulates Well the Plasticity of Neural Synaptic Connections
Authors: Bile Alessandro , Tari Hamed , Pepino Riccardo , Nabizada Arif , Fazio Eugenio
Published: April 2024

In recent years, the need for systems capable of achieving the dynamic learning and information storage efficiency of the biological brain has led to the emergence of neuromorphic research. In particular, neuromorphic optics was born with the idea of reproducing the functional and structural properties of the biological brain. In this context, solitonic neuromorphic research has demonstrated the ability to reproduce dynamic and plastic structures capable of learning and storing through conformational changes in the network. In this paper, we demonstrate that solitonic neural networks are capable of mimicking the functional behaviour of biological neural tissue, in terms of synaptic formation procedures and dynamic reinforcement.
Clinical Outcomes and Return-to-Sport Rates following Fragment Fixation Using Hydroxyapatite/Poly-L-Lactate Acid Threaded Pins for Knee Osteochondritis Dissecans: A Case Series
Authors: Shimizu Taichi , Murata Yoichi , Nakashima Hirotaka , Nishimura Haruki , Suzuki Hitoshi , Kawasaki Makoto , Tsukamoto Manabu , Sakai Akinori , Uchida Soshi
Published: April 2024

Osteochondritis dissecans (OCD) of the knee is an uncommon injury in young active patients. There is currently a lack of knowledge regarding clinical outcomes and return-to-sport rates after fragment fixation surgery using hydroxy appetite poly-L-lactic acid (HA/PLLA) threaded pins for knee OCD among athletes. Our purpose was to investigate the clinical outcomes and return-to-sport rates following osteochondral fragment fixation using HA/PLLA pins for the treatment of knee OCD lesions among athletes. A total of 45 patients were retrospectively reviewed. In total, 31 patients were excluded, and 14 patients were included. Pre- and postoperative patient-reported outcome scores (PROSs), including the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Scale (KOOS), were compared. In addition, patients were categorized into four groups according to postoperative sports status: higher, same, lower than preinjury, or unable to return to sports. The mean age was 14.4 years (SD 1.67). All patients were male. All PROSs significantly improved at 6, 12, and 24 months postsurgery compared to presurgery. 50% of the patients returned to sports at the same or higher level after surgery. Fragment fixation using HA/PLLA pins leads to favorable clinical outcome scores and high return-to-sport rates in the treatment of athletes with knee OCD.
Postural Change of the Annual Cicada (Tibicen linnei) Helps Facilitate Backward Flight
Authors: Bode-Oke Ayodeji T. , Menzer Alec , Dong Haibo
Published: April 2024

Cicadas are heavy fliers well known for their life cycles and sound production; however, their flight capabilities have not been extensively investigated. Here, we show for the first time that cicadas appropriate backward flight for additional maneuverability. We studied this flight mode using computational fluid dynamics (CFD) simulations based on three-dimensional reconstructions of high-speed videos captured in a laboratory. Backward flight was characterized by steep body angles, high angles of attack, and high wing upstroke velocities. Wing motion occurred in an inclined stroke plane that was fixed relative to the body. Likewise, the directions of the half-stroke-averaged aerodynamic forces relative to the body (local frame) were constrained in a narrow range (<20°). Despite the drastic difference of approximately 90° in body posture between backward and forward flight in the global frame, the aerodynamic forces in both flight scenarios were maintained in a similar direction relative to the body. The forces relative to the body were also oriented in a similar direction when observed during climbs and turns, although the body orientation and motions were different. Hence, the steep posture appropriated during backward flight was primarily utilized for reorienting both the stroke plane and aerodynamic force in the global frame. A consequence of this reorientation was the reversal of aerodynamic functions of the half strokes in backward flight when compared to forward flight. The downstroke generated propulsive forces, while the upstroke generated vertical forces. For weight support, the upstroke, which typically generates lesser forces in forward flight, is aerodynamically active in backward flight. A leading-edge vortex (LEV) was observed on the forewings during both half strokes. The LEV’s effect, together with the high upstroke velocity, increased the upstroke’s force contribution from 10% of the net forces in forward flight to 50% in backward flight. The findings presented in this study have relevance to the design of micro-aerial vehicles (MAVs), as backward flight is an important characteristic for MAV maneuverability or for taking off from vertical surfaces.
A Matter of Margins in Oral Cancer—How Close Is Enough?
Authors: Szewczyk Mateusz , Pazdrowski Jakub , Pieńkowski Piotr , Wojtera Bartosz , Więckowska Barbara , Golusiński Paweł , Golusiński Wojciech
Published: April 2024

In patients with oral cancer, the risk factors for local, regional, and distant recurrence according to margin status have not been well established. We aimed to determine the risk factors for recurrence by margin status and to identify a margin cut-off point for improved survival in patients with close margins. We retrospectively reviewed adult patients treated at our centre from 2009 to 2021 for primary oral cancer. Margins were classified as positive (<1 mm), close (1 to 4.9 mm), or clear (>5 mm). Univariate and multivariate analyses were performed. A total of 326 patients (210 men) were included. The mean age was 59.1 years. Margin status was close (n = 168, 51.5%), clear (n = 83, 25.4%), or positive (n = 75, 23.0%). In the univariate analysis, positive surgical margins (HR = 7.53) had the greatest impact on distant failure. Positive surgical margins—without nodal involvement—had the greatest impact on the risk of distant failure. In the close margin group, the optimal cut-off for disease-free survival (AUC = 0.58) and overall survival (AUC = 0.63) was a deep margin > 3 mm, with survival outcomes that were comparable to the clear margin group. These finding suggest that margins < 5 mm may be sufficient in certain well-defined cases. Prospective studies are warranted to confirm these findings.
Evaluation of Helium Ion Radiotherapy in Combination with Gemcitabine in Pancreatic Cancer In Vitro
Authors: Cepni Bahar , Tessonnier Thomas , Dokic Ivana , Brons Stephan , Tawk Bouchra , Mairani Andrea , Abdollahi Amir , Debus Jürgen , Herfarth Klaus , Liermann Jakob
Published: April 2024

Background: Pancreatic cancer is one of the most aggressive and lethal cancers. New treatment strategies are highly warranted. Particle radiotherapy could offer a way to overcome the radioresistant nature of pancreatic cancer because of its biological and physical characteristics. Within particles, helium ions represent an attractive therapy option to achieve the highest possible conformity while at the same time protecting the surrounding normal tissue. The aim of this study was to evaluate the cytotoxic efficacy of helium ion irradiation in pancreatic cancer in vitro. Methods: Human pancreatic cancer cell lines AsPC-1, BxPC-3 and Panc-1 were irradiated with photons and helium ions at various doses and treated with gemcitabine. Photon irradiation was performed with a biological cabin X-ray irradiator, and helium ion irradiation was performed with a spread-out Bragg peak using the raster scanning technique at the Heidelberg Ion Beam Therapy Center (HIT). The cytotoxic effect on pancreatic cancer cells was measured with clonogenic survival. The survival curves were compared to the predicted curves that were calculated via the modified microdosimetric kinetic model (mMKM). Results: The experimental relative biological effectiveness (RBE) of helium ion irradiation ranged from 1.0 to 1.7. The predicted survival curves obtained via mMKM calculations matched the experimental survival curves. Mainly additive cytotoxic effects were observed for the cell lines AsPC-1, BxPC-3 and Panc-1. Conclusion: Our results demonstrate the cytotoxic efficacy of helium ion radiotherapy in pancreatic cancer in vitro as well as the capability of mMKM calculation and its value for biological plan optimization in helium ion therapy for pancreatic cancer. A combined treatment of helium irradiation and chemotherapy with gemcitabine leads to mainly additive cytotoxic effects in pancreatic cancer cell lines. The data generated in this study may serve as the radiobiological basis for future experimental and clinical works using helium ion radiotherapy in pancreatic cancer treatment.
Retrospective Long-Term Evaluation of Conventional Transarterial Chemoembolization for Hepatocellular Carcinoma over 20 Years
Authors: Vogl Thomas J. , Adwan Hamzah , Wolff Leonard , Lahrsow Maximilian , Gruber-Rouh Tatjana , Nour-Eldin Nour-Eldin Abdelrehim , Trojan Jörg , Bechstein Wolf-Otto , Naguib Nagy N. N.
Published: April 2024

The aim of this study was to retrospectively evaluate the effects of conventional transarterial chemoembolization (cTACE) for the treatment of hepatocellular carcinoma over 20 years regarding overall survival (OS) and prognostic factors for OS. During the period from 1996 to 2016, 836 patients with HCC were treated with cTACE. Data evaluation was performed on the basis of pre- and postinterventional MRI and CT scans. Survival analysis was performed by Kaplan–Meier estimator; prognostic factors were determined by the use of Cox regression analysis. Overall, 4084 (mean 4.89 TACE sessions/patient) procedures were assessed. Median OS was 700 days (99% CI, 632.8–767.2). Depending on the indication, patients treated with a neoadjuvant intention showed the best OS (1229 days, 99% CI 983.8–1474.2) followed by curative intention (787 days, 99% CI 696.3–877.7), and then palliative intention (360 days, 99% CI 328.4–391.6). Portal vein thrombosis (HR 2.19, CI 1.63–2.96, and p < 0.01) and Child–Pugh class B or worse (HR 1.44, CI 1.11–1.86, and p < 0.001) were significantly associated with shorter OS. Patients with HCC benefit from TACE after careful patient selection. Portal vein thrombosis and Child–Pugh class B or worse are significantly unfavorable prognostic factors for patients’ survival.
Reactivation of Varicella-Zoster Virus in Patients with Lung Cancer Receiving Immune Checkpoint Inhibitors: Retrospective Nationwide Population-Based Cohort Study from South Korea
Authors: Jung Jiyun , Park Seong-Yeon , Park Jae-Yoon , Kim Dalyong , Lee Kyoungmin , Choi Sungim
Published: April 2024

Background: This study aimed to determine the association between immune checkpoint inhibitors (ICIs) and the risk of herpes zoster (HZ) incidence in patients with lung cancer. Method: We obtained national claims data of 51,021 patients from South Korea with lung cancer between August 2017 and December 2021. The study population was classified into ICI and non-ICI groups based on the prescription of ICIs at least once during the study period. To estimate the effects of ICIs treatment compared with those without ICIs treatment on HZ incidence, we used the Cox proportional hazards model adjusted for sex, age, comorbidities, and concomitant use of immunosuppressive drugs. Stratified analyses based on sex, age, and comorbidities were conducted to identify corresponding risk factors. Results: Of the 51,021 study participants, 897 (1.8%) were prescribed ICIs and 2262 (4.4%) were diagnosed with HZ. Approximately 75.6% of the patients receiving ICIs were male, and the prevalence of diabetes, cardiovascular disease, and chronic lung disease in the ICI group was significantly lower than that in the non-ICIs group. The Kaplan–Meier plot showed that the probability of incidence of HZ in the ICIs group was lower than that in the non-ICIs group. Additionally, treatment with ICIs was associated with a 31% lower incidence of developing HZ when compared to that seen without ICIs treatment (95% confidence interval [CI], 0.48–1.00). This association was stronger in females (hazard ratio [HR], 0.42; 95% CI, 0.19–0.94) and those less than 68 years of age (HR, 0.58; 95% CI, 0.34–0.99). Conclusions: In these real-world data from an Asian population with lung cancer, ICIs treatment might be associated with a reduced risk of HZ compared to that without ICIs treatment.
Heat Shock Proteins, a Double-Edged Sword: Significance in Cancer Progression, Chemotherapy Resistance and Novel Therapeutic Perspectives
Authors: Kunachowicz Dominika , Król-Kulikowska Magdalena , Raczycka Wiktoria , Sleziak Jakub , Błażejewska Marta , Kulbacka Julita
Published: April 2024

Heat shock proteins (Hsps) are involved in one of the adaptive mechanisms protecting cells against environmental and metabolic stress. Moreover, the large role of these proteins in the carcinogenesis process, as well as in chemoresistance, was noticed. This review aims to draw attention to the possibilities of using Hsps in developing new cancer therapy methods, as well as to indicate directions for future research on this topic. In order to discuss this matter, a thorough review of the latest scientific literature was carried out, taking into account the importance of selected proteins from the Hsp family, including Hsp27, Hsp40, Hsp60, Hsp70, Hsp90 and Hsp110. One of the more characteristic features of all Hsps is that they play a multifaceted role in cancer progression, which makes them an obvious target for modern anticancer therapy. Some researchers emphasize the importance of directly inhibiting the action of these proteins. In turn, others point to their possible use in the design of cancer vaccines, which would work by inducing an immune response in various types of cancer. Due to these possibilities, it is believed that the use of Hsps may contribute to the progress of oncoimmunology, and thus help in the development of modern anticancer therapies, which would be characterized by higher effectiveness and lower toxicity to the patients.
Formulation and Characterization of Non-Toxic, Antimicrobial, and Alcohol-Free Hand Sanitizer Nanoemulgel Based on Lemon Peel Extract
Authors: Ibrahim Faten Mohamed , Shalaby Eman Samy , El-Liethy Mohamed Azab , Abd-Elmaksoud Sherif , Mohammed Reda Sayed , Shalaby Said I. , Rodrigues Cristina V. , Pintado Manuela , Habbasha El Sayed El
Published: April 2024

Recently, hand sanitization has gained attention for preventing disease transmission. Many on-the-market convenient dermal sanitizers contain alcohol, which can be detrimental to the skin. Therefore, three nanoemulgel formulations (LN-F1, LN-F2, LN-F3) incorporating lemon peel extract (LE), and with various increasing concentrations of xanthan gum as a gelling agent and stabilizer, were developed and characterized as a novel alternative. All formulations showed non-Newtonian shear-thinning flow behavior, particle size values below 200 nm, and increasing zeta potential with higher xanthan gum concentrations. All nanoemulgel formulations exhibited greater in vitro phenolic compound release than free LE. LN-F2 (1.0% LE, 20.0% mineral oil, 20.0% Span 80, 4.0% Cremophor RH 40, 4.0% PEG 400, 0.5% xanthan gum, 50.5% dH2O) was selected as the optimal formulation due to improved characteristics. LE and LN-F2 potential cytotoxicity was assessed on MA-104, showing no significant cellular morphological alterations up to 10 mg/mL for both samples. LN-F2 showed in vitro antimicrobial activity against E. coli, S. Typhimurium, P. aeruginosa, S. aureus, L. monocytogenes, and C. albicans, as well as antiviral activity against phiX 174, but no effect against rotavirus (SA-11). In vivo, LN-F2 presented a removal capacity of 83% to 100% for bacteria and 89% to 100% for fungi. These findings suggest that the formulated nanoemulgel holds potential as a safe and effective antiseptic, providing a viable alternative to commercial alcohol-based formulations.
The Occurrence of the American Burying Beetle (Nicrophorus americanus) and Associated Silphid Beetle Community in South Dakota: Implications for Managed Relocation
Authors: Hoback William Wyatt , Snethen Daniel G. , Reed Melissa , Cavallaro Michael C.
Published: April 2024

The American burying beetle, Nicrophorus americanus Olivier (Coleoptera: Siliphidae), is a federally threatened species in the United States, occurring in less than 10% of its historic range. The continued monitoring of extant populations found in South Dakota, the northernmost edge of its confirmed range, is imperative to future conservation efforts, especially with the predicted loss of the species in southern regions because of climate change. Proposed strategies to preserve the species include the reintroduction or translocation of individuals from habitats that have become unsuitable. Beyond adequate habitat and carrion resource requirements, community-level silphid interactions may challenge these efforts because of competition. From 2018 to 2020, we used 80 carrion-baited pitfall traps per year to conduct two 5-day surveys in June and August. A total of 25,923 Silphidae belonging to 15 species were collected in 1200 trap nights. Cumulatively, 1150 N. americanus were captured and marked with 263 recaptures. Like past findings, N. americanus was concentrated in western Tripp County with limited occurrence in Gregory and Todd Counties, suggesting no expansion of their known range in the past decade. Generalized linear mixed-effects models indicated N. americanus abundance was significantly predicted by the co-occurrence of the carrion beetles Oieceoptoma inaequale F. and Oiceoptoma noveboracense Forster, whereas pitfall trap catches dominated by the burying beetle Nicrophorus marginatus F. had predictively less N. americanus. Collectively, these data provide insights into the existing, northernmost N. americanus population dynamics and silphid beetle communities. Concurrent with monitoring extant populations, the characterization of silphid communities that co-occur with N. americanus may provide much-needed information for managed relocation opportunities.
Resilience of Aboveground Biomass of Secondary Forests Following the Abandonment of Gold Mining Activity in the Southeastern Peruvian Amazon
Authors: Garate-Quispe Jorge , Herrera-Machaca Marx , Pareja Auquipata Victor , Alarcón Aguirre Gabriel , Baez Quispe Sufer , Carpio-Vargas Edgar Eloy
Published: April 2024

Amazon rainforests are critical for providing a wide range of ecosystem services. In the Southeastern Peruvian Amazon; however, goldmining activities are causing severe soil degradation and forest loss. We analyzed aboveground biomass (AGB), forest structure, and species diversity recovery during secondary succession in 179 forest plots. Our study provides the first field-based quantification of AGB recovery following the abandonment by two types of goldmining (heavy machinery and suction pumping) in Madre de Dios (Peru). We found that successional secondary forests in areas subjected to suction pumping were more resilient than those in areas subjected to heavy machinery. After 20 years, mean AGB in suction pumping mining areas had reached 56% of reference forest AGB, while in areas of heavy machinery mining it was only 18%. Mining type, stand age, and distance from the forest edge had a significant effect on AGB. The influence of the distance from the forest edge on AGB varies according to mining type because the effects of species diversity on AGB are mediated by the distance from the forest edge. Our results clearly showed the dynamics of AGB recovery across a secondary succession after goldmining, and the contrasting responses of AGB between the two mining types. Our study disentangles the importance of key factors in forest recovery after mining and improves understanding of the resilience of biomass accumulation in these highly degraded ecosystems.
Development of a Three-Finger Adaptive Robotic Gripper to Assist Activities of Daily Living
Authors: Rahman Md Mahbubur , Shahria Md Tanzil , Sunny Md Samiul Haque , Khan Md Mahafuzur Rahaman , Islam Emroze , Swapnil Asif Al Zubayer , Bedolla-Martínez David , Rahman Mohammad H
Published: April 2024

A significant number of individuals in the United States use assistive devices to enhance their mobility, and a considerable portion of those who depend on such aids require assistance from another individual in performing daily living activities. The introduction of robotic grippers has emerged as a transformative intervention, significantly contributing to the cultivation of independence. However, there are few grippers in the fields, which help with mimicking human hand-like movements (mostly grasping and pinching, with adoptive force control) to grasp and carry objects. Additionally, the data are not available even on how many Activities of Daily Living (ADL) objects they can handle. The goal of the research is to offer a new three-fingered gripper for daily living assistance, which can both grasp and pinch with adaptive force, enabling the capabilities of handling wide-ranging ADL objects with a minimal footprint. It is designed to handle 90 selective essential ADL objects of different shapes (cylindrical, irregular, rectangular, and round), sizes, weights, and textures (smooth, rough, bumpy, and rubbery). The gripper boasts a meticulously engineered yet simple design, facilitating seamless manufacturing through 3D printing technology without compromising its operational efficacy. The gripper extends its functionality beyond conventional grasping, featuring the capability to pinch (such as holding a credit card) and securely hold lightweight objects. Moreover, the gripper is adaptable to grasping various objects with different shapes and weights with controlled forces. In evaluation, the developed gripper went through rigorous load tests and usability tests. The results demonstrated that the users picked and placed 75 objects out of 90 daily objects. The gripper held and manipulated objects with dimensions from 25 mm to 80 mm and up to 2.9 kg. For heavy-weight objects (like books) where the centroid is far apart from the grasping areas, it is difficult to hold them due to high torque. However, objects’ textures have no significant effect on grasping performance. Users perceived the simplicity of the gripper. Further investigation is required to assess the utility and longevity of grippers. This study contributes to developing assistive robots designed to enhance object manipulation, thereby improving individuals’ independence and overall quality of life.
Artemisia Frigida Distribution Mapping in Grassland with Unmanned Aerial Vehicle Imagery and Deep Learning
Authors: Wang Yongcai , Wan Huawei , Hu Zhuowei , Gao Jixi , Sun Chenxi , Yang Bin
Published: April 2024

Artemisia frigida, as an important indicator species of grassland degradation, holds significant guidance significance for understanding grassland degradation status and conducting grassland restoration. Therefore, conducting rapid surveys and monitoring it is crucial. In this study, to address the issue of insufficient identification accuracy due to the large density and small size of Artemisia frigida in UAV images, we improved the YOLOv7 object detection algorithm to enhance the performance of the YOLOv7 model in Artemisia frigida detection. We applied the improved model to the detection of Artemisia frigida across the entire experimental area, achieving spatial mapping of Artemisia frigida distribution. The results indicate: In comparison across different models, the improved YOLOv7 + Biformer + wise-iou model exhibited the most notable enhancement in precision metrics compared to the original YOLOv7, showing a 6% increase. The mean average precision at intersection over union (IoU) threshold of 0.5 (mAP@.5) also increased by 3%. In terms of inference speed, it ranked second among the four models, only trailing behind YOLOv7 + biformer. The YOLOv7 + biformer + wise-iou model achieved an overall detection precision of 96% and a recall of 94% across 10 plots. The model demonstrated superior overall detection performance. The enhanced YOLOv7 exhibited superior performance in Artemisia frigida detection, meeting the need for rapid mapping of Artemisia frigida distribution based on UAV images. This improvement is expected to contribute to enhancing the efficiency of UAV-based surveys and monitoring of grassland degradation. These findings emphasize the effectiveness of the improved YOLOv7 + Biformer + wise-iou model in enhancing precision metrics, overall detection performance, and its applicability to efficiently map the distribution of Artemisia frigida in UAV imagery for grassland degradation surveys and monitoring.
Analysis of Coverage and Capacity for UAV-Aided Networks with Directional mmWave Communications
Authors: Wei Xingchen , Peng Laixian , Xu Renhui , Li Aijing , Yu Xingyue , Wang Hai
Published: April 2024

Millimeter wave (mmWave) unmanned aerial vehicle (UAV)-aided networks have enormous application potential due to their large bandwidth and ultra-high speed, being regarded as an effective technology for improving the reliability of military and civilian fields. However, due to their complex electromagnetic spectrum environment and the sensitivity of mmWaves to blocking effects, its performance analysis faces certain difficulties. This article investigates the coverage and network capacity of mmWave UAV-aided networks under significant blocking effects and complex electromagnetic environments; for this purpose, we equipped each UAV with mmWave antennas featuring adjustable beamwidth and direction. A Matérn hard-core point process (MHCPP) with repulsion constraints was also employed to reflect the minimum distance constraints to isolate the mutual interference between UAVs. Then, using a stochastic geometric analysis, we derived the coverage and capacity characteristics and further obtained a closed-form expression for the network coverage probability. Finally, the simulation results showed that the network throughput could reach 86% when the density of UAVs was half of that of ground base stations (GBSs) in the city center, validating the efficiency and accuracy of our theoretical derivations.
Teaching Bilingually: Unlocking the Academic and Cognitive Potential—Teachers’ Insights
Authors: Creed Emma , Filippi Roberto , Holliman Andrew
Published: April 2024

Recent quantitative research on bilingual education suggests beneficial academic outcomes for pupils regardless of socio-economic status (SES). Bilingual education in England, a relatively novel phenomenon, may be better understood from teachers’ perspectives; however, there is a paucity of qualitative research in this area. To fill the gap, the present study explores the unique perspective of a sample of bilingual schoolteachers regarding the children who attend bilingual schools and the effects of bilingual education on children’s academic and non-academic development. Semi-structured interviews were conducted with six bilingual schoolteachers, and thematic analysis was adopted to interpret their experiences in greater depth. A thematic analysis revealed four superordinate themes: Academic and Socio-Cultural Effects, Privilege in Bilingual Education, Bilingual Education Takes Time, and Special Educational Needs. These results highlight academic, socio-cultural, and linguistic benefits with important implications for promoting equity in bilingual education. Further research should focus on schools with a higher proportion of students from lower socio-economic status backgrounds.
Robust Direct Power Control of Three-Phase PWM Rectifier with Mismatched Disturbances
Authors: Hou Bo , Qi Jiayan , Li Huan
Published: April 2024

To effectively eliminate the impacts of both matched and mismatched power disturbances in a three-phase PWM rectifier, this paper proposes a robust direct power control (RDPC) method with a single-loop control structure. Firstly, a nonlinear power model of the three-phase PWM rectifier is established. Then, using the exact feedback linearization method, a linearized power model including matched and mismatched power disturbances is derived and achieves the decoupling of active and reactive power. Secondly, to regulate the DC bus voltage, a sliding-mode controller (SMC) combined with a nonlinear disturbance observer (NDO) is proposed. The proposed SMC combined with an NDO (SMC + NDO) method features a single-loop control structure, which enables a faster response and simpler structure compared to the dual-loop DPC method. By incorporating estimated mismatched power disturbance into the sliding-mode surface, it overcomes the SMC’s defect in incompletely suppressing mismatched disturbances and enables the simultaneous regulation of voltage and active power. Additionally, it effectively reduces sliding-mode chattering. To regulate reactive power, a sliding-mode controller based on the exponential convergence law is designed to suppress matched reactive power disturbances. Finally, the simulation and experimental comparative results demonstrate that the proposed controller exhibits stronger robustness against matched and mismatched power disturbances, as well as a better performance under the constant power load (CPL).
Comprehensive Investigation of Promising Techniques to Enhance the Voltage Sharing among SiC MOSFET Strings, Supported by Experimental and Simulation Validations
Authors: Zhao Weichuan , Ghafoor Sohrab , Lagerweij Gijs Willem , Rietveld Gert , Vaessen Peter , Niasar Mohamad Ghaffarian
Published: April 2024

This paper comprehensively reviews several techniques that address the static and dynamic voltage balancing of series-connected MOSFETs. The effectiveness of these techniques was validated through simulations and experiments. Dynamic voltage-balancing techniques include gate signal delay adjustment methods, passive snubbers, passive clamping circuits, and hybrid solutions. Based on the experimental results, the advantages and disadvantages of each technique are investigated. Combining the gate-balancing core method with an RC snubber, which has proven both technically and commercially attractive, provides a robust solution. If the components are sorted and binned, voltage-balancing techniques may not be necessary, further enhancing the commercial viability of series-connected MOSFETs. An investigation of gate driver topologies yields one crucial conclusion: magnetically isolated gate drivers offer a simple and cost-effective solution for high-frequency (HF) applications (2.5–50 kHz) above 8 kV with an increased number of series devices. Below 8 kV, it is advantageous to move the isolation barrier from the gate drive IC to an optocoupler and isolated supply, allowing for a simple design with commercially available components.
AST-DF: A New Webshell Detection Method Based on Abstract Syntax Tree and Deep Forest
Authors: Dong Chengfeng , Li Daofeng
Published: April 2024

Webshell is a kind of web-language-based website backdoor, which is usually used by attackers to control web servers. Due to its dangerous nature, how to detect Webshell effectively has become a hot research topic in current Web security research. With the rapid development of Webshell evasion technology, the existing Webshell detection methods have the problem of insufficient ability to detect unknown Webshells. In order to solve the above problems and achieve effective Webshell detection, this study proposes a Webshell detection method based on the abstract syntax tree (AST) and deep forest (DF) model called AST-DF. AST-DF first extracts the abstract syntax tree from the PHP code; then, the abstract syntax tree sequence is feature extracted and vectorized using N-gram and TF-IDF. Finally, the vectors are imported into the deep forest model for classification to determine whether the PHP code to be detected is a Webshell or not. The experimental results show that AST-DF achieves remarkable effects in the task of detecting PHP-type Webshells, with a 99.61% accuracy rate, and the values of precision, recall, and F1 score are more than 99%.
Model Predictive Control for Trajectory Planning Considering Constraints on Vertical Load Variation
Authors: Zhang Hongtao , Yao Jialing , Tian Songmei
Published: April 2024

To address the issue of centrifugal force affecting the vertical load during the stability and trajectory planning of autonomous vehicles during high-speed cornering and obstacle avoidance, a model predictive control of trajectory planning and tracking is proposed that considers the roll factor using only a two-degrees-of-freedom vehicle dynamics model. Firstly, a trajectory planning controller is designed. As a predictive model, a dual-track two-degrees-of-freedom vehicle dynamics model is established. This model describes the relationship between tire lateral forces and vertical loads using a quadratic nonlinear tire model. To reflect the actual dynamic state of the vehicle, the controller incorporates a nonlinear constraint that considers vertical load variations. The nonlinear optimization problem is transformed into a simplified quadratic programming problem by using the Jacobian matrix method to linearize the constraints. By fitting a fourth-degree polynomial curve to the discrete points calculated by the replanning algorithm, an optimal collision-free trajectory is obtained. Secondly, an MPC trajectory tracking controller is designed to control the vehicle in real time along the optimal trajectory from the planning, incorporating control quantity constraints, control increment constraints, and lateral angle constraints to maintain the vehicle’s motion state. We transform the trajectory tracking control problem into a quadratic programming problem, solving for the optimal control sequence for the autonomous vehicle to track the trajectory, achieving an optimized solution and rolling time domain control. Finally, the effectiveness of the vehicle’s obstacle avoidance planning and tracking under high-speed double-lane-change maneuver conditions is validated using the Simulink simulation platform. The results indicate that the designed planning and tracking controllers effectively improve the obstacle avoidance planning and tracking control for high-speed autonomous vehicles.
A 2.25 ppm/°C High-Order Temperature-Segmented Compensation Bandgap Reference
Authors: Jia Shichao , Ye Tianchun , Xiao Shimao
Published: April 2024

This paper presents a bandgap reference (BGR) with high-order temperature-segmented compensation. The compensation signal is generated using the voltage difference between two bipolar junction transistor (BJT) emitter bases, each of which individually loads a proportional-to-absolute temperature (PTAT) current and a zero-to-absolute temperature (ZTAT) current. The proposed BGR achieves a low-temperature coefficient (TC) over a wide temperature range. Simulations using the 0.18 μm Bipolar-CMOS-DMOS process show a typical TC of 2.25 ppm/°C from −40 °C to 125 °C. With an active area of 0.07986 mm2, it consumes 36 μW power under an operating voltage of 1 V. The integrated output noise from 0.1 Hz to 10 Hz is 81.1 μV.
Automatic Classification of All-Sky Nighttime Cloud Images Based on Machine Learning
Authors: Zhong Xin , Du Fujia , Hu Yi , Hou Xu , Zhu Zonghong , Zheng Xiaogang , Huang Kang , Ren Zhimin , Hou Yonghui
Published: April 2024

Cloud-induced atmospheric extinction and occlusion significantly affect the effectiveness and quality of telescope observations. Real-time cloud-cover distribution and long-term statistical data are essential for astronomical siting and telescope operations. Visual inspection is currently the primary approach for analyzing cloud distribution at ground-based astronomical sites. However, the main disadvantages of manual observation methods are human subjectivity, heavy workloads, and poor real-time performance. Therefore, a real-time automatic cloud image classification method is desperately needed. This paper presents a novel cloud identification method named the PSO+XGBoost model, which combines eXtreme Gradient Boosting (XGBoost) with particle-swarm optimization (PSO). The entire cloud image is divided into 37 sub-regions to identify the distribution of the clouds more precisely. Nineteen features, including the sky background, star density, lighting conditions, and subregion grayscale values, are extracted. The experimental results have shown that the overall classification accuracy is 96.91%, and our model can outperform several state-of-the-art baseline methods. Our approach achieves high accuracy in comparison with the manual observation methods. Moreover, this method meets telescope real-time scheduling requirements.