bluuebunny/crossref_metadata_2025 huggingface dataset:
Exosomes: the next frontier in vaccine development and delivery
Authors: Tan Dan , Li Guangyao , Fu Wenyan , Lei Changhai
Published: June 2024

Exosomes are small disk-shaped extracellular vesicles (EVs) that are naturally released into the environment by different types of cells. Exosomes range from 30-150 nm in size and contain complex RNA and proteins. They are widely found in body fluids such as blood, saliva, urine and breast milk and participate in cell communication by functioning as cell messengers. Almost all cell types can transmit information and exchange substances through the production and release of exosomes to regulate proliferation, differentiation, apoptosis, the immune response, inflammation, and other biological functions. Because exosomes exist widely in various body fluids, they are easy to obtain and detect and have the potential for use in disease diagnosis and prognosis detection. Exosomes can be genetically fused with targeted proteins, enhancing their biocompatibility and immunogenicity. Therefore, exosomes are the preferred vector tools for vaccines. In this review, we describe the characteristics of exosomes and discuss their unique and ambiguous functions in the immune microenvironment after infection. In this regard, we explored the ability of exosomes to carry immunogenic virus antigens and to establish adaptive immune responses. Exosomes can provide an interesting platform for antigen presentation and since vaccines are a powerful method for the prevention of infectious diseases, we further review the advantages and disadvantages of the use of exosomes in vaccine preparation. Overall, exosomes are emerging as a promising avenue for vaccine development.
Identification of specific reference gene for normalization of RT-qPCR data in rhythmic gene expression studies of the effect of developmental hormone antagonist in postembryonic development in Bombyx mori
Authors: Dalai Minurani , Jagota Anita
Published: June 2024

Bombyx mori is a lepidopteran holometabolous insect with distinct developmental stages: egg, larvae, pupae, and adult. The lepidopteran insect undergoes major modifications in the central nervous system (CNS) so as to adapt to the lifestyle of these distinct stages with specific habitats and functions from voraciously feeding larval stages to flying reproductive adults via dormant pupal stages. Such transitions are linked to transcriptional, epigenetic, and translational complexities. Therefore, studying rhythmic gene expression in CNS of various developmental stages and the effects of antagonists on developmental hormones requires a very stable reference gene (RG). To facilitate rhythmic gene expression studies using reverse transcription quantitative polymerase chain reaction (RT-qPCR) in B. mori and the effect of developmental hormone juvenile hormone (JH) and 20-hydroxy ecdysone hormone (20 HE), antagonists Precocene 1 and testosterone, respectively, were used. Eight candidate RGs, namely, Translational initiation factor 3 subunit 4 (TI3S4), Translational initiation factor 3 subunit 5 (TI3S5), Ribosomal protein subunit 7 (RPs7), TATA-binding protein association factor (TAF13), Translational initiation factor 4 A (TI4A), Ribosomal protein (RPL32), Elongation factor 1 (EF1), and Arginine kinase (AK), were assessed in the CNS of B. mori. The postembryonic developmental (PED) stages used were the fifth late larval instar, early pupa, mid pupa, late pupa, and adult. The assessments were done at four different time points, Zeitgeber time (ZT) 0, 6, 12, and 18, to find stability towards 24-h rhythmic expression. RefFinder, geNorm, and Ct value analysis were performed. RefFinder and geNORM studies suggested stability order as TI3S4 > TI3S5 > RPs7, but Ct value evaluation showed stability order as TI3S5 > TI3S4 > RPs7. We therefore demonstrated that TI3S4, TI3S5, and RPs7 can be used as RG in various PED stages in CNS of B. mori (Strain: CB-hybrid, PM×CSR2) towards studies with effects of JH and 20 HE antagonists.
Efficacy of lumbar and abdominal muscle rehabilitation training on degree of osteoporosis, pain and anxiety in elderly patients with osteoporotic vertebral compression fracture after PKP and compliance analysis
Authors: Xu Yaqin , Li Dong , Zhang Qian , Tong Lulu
Published: June 2024

Purpose

To explore the rehabilitation effect and compliance of lumbar and abdominal muscle rehabilitation training in patients with osteoporotic vertebral compression fracture (OVCF) after percutaneous balloon vertebroplasty (PKP).

Methods

A total 177 elderly patients with OVCF were divided into rehabilitation group (n = 104) and control group (n = 73) according to whether they received psoas and abdominal muscle rehabilitation training for 3 months after PKP. The differences of general data, orthopaedic rehabilitation, prognosis and bone metabolism were compared between the two groups. All the patients were divided into compliance group (68 cases) and non-compliance group (36 cases) according to compliance. Orthopaedic rehabilitation indicators, prognostic indicators of PKP, and bone metabolism-related parameters were collected for analysis of Chi-square test and Logistic regression. ROC curve was used to analyze the predictive value of bone metabolism related indicators in the compliance of lumbar and abdominal muscle rehabilitation training.

Results

There was no significant difference in the general data between the rehabilitation training group and the control group (Allp > 0.05). Compared with the control group, the Berg balance scale score was significantly increased, while the Visual Analogue Scale (VAS) score, Oswestry Disability Index (ODI) score and the proportion of new fractures were significantly decreased in the rehabilitation training group (Allp < 0.05). Compared with the control group, the bone mineral density (BMD) T value, osteocalcin (OCN) and 25-hydroxyvitamin D (25 (OH) D) levels were significantly increased and the levels of type I N-propeptide (P1NP) and β-isomerized C-terminal telopeptides (β-CTX) were significantly decreased in the rehabilitation training group compared with the control group (Allp < 0.05). Chi-square test and Logistic regression analysis showed that age > 75 years, severe anxiety, severe pain and postoperative complications were significantly associated with the compliance of psoas and abdominal muscle rehabilitation training in patients with OVCF after PKP. ROC curve analysis showed that BMD T value, OCN, P1NP, β-CTX, or 25-OH-D levels predicted the AUC of rehabilitation training compliance in patients with OVCF after PKP were 0.821, 0.835, 0.736, 0.715, and 0.748, respectively.

Conclusion

Rehabilitation training of lumbar and abdominal muscles can significantly improve the efficacy of PKP, reduce the degree of osteoporosis and improve the prognosis of patients with OVCF. Age, anxiety, pain and postoperative complications were independent risk factors affecting the compliance of psoas and abdominal rehabilitation training in patients with OVCF after PKP.
Re-telling the story of aminoglycoside ototoxicity: tales from sub-Saharan Africa
Authors: Adeyemo Adebolajo A. , Adedokun Babatunde , Adeolu Josephine , Akinyemi Joshua O. , Omotade Olayemi O. , Oluwatosin Odunayo M.
Published: June 2024

Background

Aminoglycosides, such as Streptomycin, are cheap, potent antibiotics widely used Sub-Saharan Africa. However, aminoglycosides are the commonest cause of ototoxicity. The limited prospective epidemiological studies on aminoglycoside ototoxicity from Sub-Saharan Africa motivated this study to provide epidemiological information on Streptomycin-induced ototoxicity, identify risk factors and predictors of ototoxicity.

Method

A longitudinal study of 153 adults receiving Streptomycin-based anti-tuberculous drugs was done. All participants underwent extended frequency audiometry and had normal hearing thresholds at baseline. Hearing thresholds were assessed weekly for 2 months, then monthly for the subsequent 6 months. Ototoxicity was determined using the ASHA criteria. Descriptive statistics were used to analyze socio-demographic variables. Ototoxicity incidence rate was calculated, and Kaplan–Meier estimate used to determine cumulative probability of ototoxicity. Chi-square test was done to determine parameters associated with ototoxicity and Cox regression models were used to choose the predictors of ototoxicity.

Results

Age of participants was 41.43 ± 12.66 years, with a male-to-female ratio of 1:0.6. Ototoxicity was found in 34.6% of the participants, giving an incidence of 17.26 per 1,000-person-week. The mean onset time to ototoxicity was 28.0 ± 0.47 weeks. By 28th week, risk of developing ototoxicity for respondents below 40 years of age was 0.29, and for those above 40 years was 0.77. At the end of the follow-up period, the overall probability of developing ototoxicity in the study population was 0.74. A significant difference in onset of ototoxicity was found between the age groups: the longest onset was seen in <40 years, followed by 40–49 years, and shortest onset in ≥50 years. Hazard of ototoxicity was significantly higher in participants aged ≥50 years compared to participants aged ≤40 years (HR = 3.76, 95% CI = 1.84–7.65). The probability of ototoxicity at 40 g, 60 g and 80 g cumulative dose of Streptomycin was 0.08, 0.43 and 2.34, respectively. Age and cumulative dose were significant predictors of ototoxicity.

Conclusion

The mean onset time to Streptomycin-induced ototoxicity was 28 weeks after commencement of therapy. Age and cumulative dose can reliably predict the onset of Streptomycin-induced ototoxicity. Medium to long term monitoring of hearing is advised for patients on aminoglycoside therapy.
Unveiling a potential threat to forest ecosystems: molecular diagnosis of Alliaria petiolata, a newly introduced alien plant in Korea
Authors: Choi Tae-Young , Son Dong Chan , Oh Ami , Lee Soo-Rang
Published: July 2024

Identifying stages of a species invasion in a new habitat (i.e., colonization, establishment, and landscape spread) and their primary determinants in biological invasion warrants attention, as it provides vital insights for preventing non-native species from becoming pervasive invaders. However, delineating invasion stages and their associated factors can pose significant challenges due to the ambiguous distinctions between these stages. Alliaria petiolata, one of the most noxious weeds in woodland habitats, has recently been introduced to Korea and observed in a few distant locations. Although the plant’s spread has been relatively slow thus far, rapid spread is highly likely in the future, given the high invasive potential reported elsewhere. We indirectly diagnose the current status of A. petiolata invasion in Korea through the assessment of genetic diversity and phylogenetic inferences using genome-wide molecular markers and cytological data. We analyzed 86 individual samples collected from two native and six introduced populations, employing 1,172 SNPs. Our analysis estimated within- and among-population genetic diversity and included two clustering analyses. Furthermore, we investigated potential gene flow and reticulation events among the sampled populations. Our data unraveled that Korean garlic mustard exhibits a hexaploid ploidy level with two distinct chromosome numbers, 2n = 36 and 42. The extent of genetic diversity measured in Korean populations was comparable to that of native populations. Using genome-wide SNP data, we identified three distinct clusters with minor gene flow, while failing to detect indications of reticulation among Korean populations. Based on the multifaceted analyses, our study provides valuable insights into the colonization process and stressed the importance of closely monitoring A. petiolata populations in Korea.
Genetic trends in the Kenya Highland Maize Breeding Program between 1999 and 2020
Authors: Ligeyo Dickson O. , Saina Edward , Awalla Bornface J. , Sneller Clay , Chivasa Walter , Musundire Lennin , Makumbi Dan , Mulanya Mable , Milic Dragan , Mutiga Samuel , Lagat Abraham , Das Biswanath , Prasanna Boddupali M.
Published: July 2024

Optimization of a breeding program requires assessing and quantifying empirical genetic trends made through past efforts relative to the current breeding strategies, germplasm, technologies, and policy. To establish the genetic trends in the Kenyan Highland Maize Breeding Program (KHMP), a two-decade (1999–2020) historical dataset from the Preliminary Variety Trials (PVT) and Advanced Variety Trials (AVT) was analyzed. A mixed model analysis was used to compute the genetic gains for traits based on the best linear unbiased estimates in the PVT and AVT evaluation stages. A positive significant genetic gain estimate for grain yield of 88 kg ha−1 year−1 (1.94% year−1) and 26 kg ha−1 year−1 (0.42% year−1) was recorded for PVT and AVT, respectively. Root lodging, an important agronomic trait in the Kenya highlands, had a desired genetic gain of −2.65% year−1 for AVT. Results showed improvement in resistance to Turcicum Leaf Blight (TLB) with −1.19% and −0.27% year−1 for the PVT and AVT, respectively. Similarly, a significant genetic trend of −0.81% was noted for resistance to Gray Leaf Spot (GLS) in AVT. These findings highlight the good progress made by KHMP in developing adapted maize hybrids for Kenya’s highland agroecology. Nevertheless, the study identified significant opportunities for the KHMP to make even greater genetic gains for key traits with introgression of favorable alleles for various traits, implementing a continuous improvement plan including marker-assisted forward breeding, sparse testing, and genomic selection, and doubled haploid technology for line development.
The dynamic strategy shifting task: Optimisation of an operant task for assessing cognitive flexibility in rats
Authors: Flintoff Jonathan Martin , Alexander Suzy , Kesby James Paul , Burne Thomas Henry
Published: June 2024

Introduction

Although schizophrenia is associated with a broad range of symptoms including hallucinations, delusions, and reduced motivation, measures of cognitive dysfunction, including cognitive flexibility and executive function, are the strongest predictors of functional outcomes. Antipsychotic medications are useful for reducing psychotic symptoms, but they are ineffective at improving cognitive deficits. Despite extensive investment by industry, the transition from preclinical to clinical trials has not been successful for developing precognitive medications for individuals with schizophrenia. Here, we describe the optimisation of a novel dynamic strategy shifting task (DSST) using standard operant chambers to investigate the optimal stimuli required to limit the extensive training times required in previous tasks.

Methods

We determined that optimal learning by male and female Sprague Dawley rats for the flexibility task incorporated dynamic strategy shifts between spatial rules, such as following a visual cue or responding at one location, and non-spatial rules, such as responding to a central visual or auditory cue. A minimum of 6 correct consecutive responses were required to make a within-session change in the behavioural strategies. As a proof of concept, we trained and tested 84 Sprague Dawley rats on the DSST, and then assessed their cognitive flexibility using a within-subject design after an acute dose of ketamine (0, 3, 10 mg/kg). Rats made fewer premature and more perseverant responses to initiate a trial following ketamine. The effects of ketamine on trials to criterion was dependent on the rule.

Results

Ketamine induced a significant improvement on the reversal of a non-spatial visual discrimination rule. There was no significant effect of ketamine on the spatial visual or response discrimination rules.

Discussion

The DSST is a novel assay for studying distinct forms of cognitive flexibility and offers a rapid and adaptable means of assessing the ability to shift between increasingly challenging rule conditions. The DSST has potential utility in advancing our understanding of cognitive processes and the underlying neurobiological mechanisms related to flexibility in neuropsychiatric and neurological conditions where executive dysfunctions occur.>
Branching out: mobilizing community assets to support the mental health and wellbeing of children in primary schools
Authors: Dadswell Anna , Bungay Hilary , Acton Faye , Walshe Nicola
Published: June 2024

Introduction

Mobilizing existing creative, cultural and community assets is seen as a crucial pathway to improving public health. Schools have been identified as key institutional community assets and arts-in-nature practice has been shown to promote children’s mental health. The ‘Branching Out’ research investigated how an established arts-in-nature practice called ‘Artscaping’ could be scaled up through the mobilization of community assets including school staff and local volunteers to reach more children in primary schools.

Methods

The Branching Out model was piloted in six primary schools across Cambridgeshire with ‘Community Artscapers’ delivering 1.5-h Artscaping sessions with children outdoors for 8 weeks. Interviews were conducted with 11 Community Artscapers (six school staff and five volunteers) and four school leaders reflecting on their experiences of the Branching Out model and the data was subject to a reflexive thematic analysis.

Results

The findings presented here discuss themes relating to mobilizing community assets, including framing the opportunity, recruiting and sustaining volunteers, training and supporting Community Artscapers, and tensions in roles and responsibilities. They also cover impacts for the children, including mental health provision, freedom in creativity and being outside, personal development, emotional impacts, and social connection, as well as impacts for the Community Artscapers, including making a difference, emotional wellbeing, personal and professional development, and connection and community.

Discussion

These findings are considered in terms of their alignment with public health policy drivers and the potential for the Branching Out model to become replicable and self-sustaining across schools to promote children’s mental health as a public health intervention.
Nonlinear and threshold effects of built environment on older adults’ walking duration: do age and retirement status matter?
Authors: Wu Jiani , Li Chaoyang , Zhu Li , Liu Xiaofei , Peng Bozhezi , Wang Tao , Yuan Shengqiang , Zhang Yi
Published: June 2024

Introduction

Walking plays a crucial role in promoting physical activity among older adults. Understanding how the built environment influences older adults’ walking behavior is vital for promoting physical activity and healthy aging. Among voluminous literature investigating the environmental correlates of walking behaviors of older adults, few have focused on walking duration across different age groups and life stages, let alone examined the potential nonlinearities and thresholds of the built environment.

Methods

This study employs travel diary from Zhongshan, China and the gradient boosting decision trees (GBDT) approach to disentangle the age and retirement status differences in the nonlinear and threshold effects of the built environment on older adults’ walking duration.

Results

The results showed built environment attributes collectively contribute 57.37% for predicting older adults’ walking duration, with a higher predicting power for the old-old (70+ years) or the retired. The most influencing built environment attribute for the young-old (60–70 years) is bus stop density, whereas the relative importance of population density, bus stop density, and accessibility to green space or commercial facilities is close for the old-old. The retired tend to walk longer in denser-populated neighborhoods with better bus service, but the non-retired are more active in walking in mixed-developed environments with accessible commercial facilities. The thresholds of bus stop density to encourage walking among the young-old is 7.8 counts/km2, comparing to 6 counts/km2 among the old-old. Regarding the green space accessibility, the effective range for the non-retired (4 to 30%) is smaller than that of the retired (12 to 45%).

Discussion

Overall, the findings provide nuanced and diverse interventions for creating walking-friendly neighborhoods to promote walking across different sub-groups of older adults.
Cognitive abilities, insurance decisions, and labor supply behavior: evidence from rural China
Authors: Yang Ziyue
Published: June 2024

Introduction

How cognitive abilities affect financial and economic decision is an important issue that has attracted the attention of economics.

Method

This paper uses the China Family Panel Studies (CFPS) 2010, 2014, and 2018 survey data to empirically test the impact of cognitive skills on the insurance participation decisions in rural China.

Results and discussion

The results show that higher word ability is correlated to higher social health insurance participation and both word and math ability leads to higher social pension participation. Mechanism analysis reveals that individuals with higher cognitive skills are more likely to be affected by peers in insurance decision, and higher cognitive skills increase personal income that enables them to enroll in the social insurance. Further investigation of labor supply behavior suggests that while cognitive skills positively affect non-agricultural labor participation, cognitive skills amplify the negative effect of social security on labor supply.
Phylogeography of the giant honey bees based on mitochondrial gene sequences
Authors: Bhatta Chet P. , Zajonz Sarah C. , Smith Deborah R.
Published: June 2024

Our goal was to resolve phylogenetic relationships among Apis laboriosa, and the Apis dorsata subspecies A. d. dorsata, A. d. binghami, and A. d. breviligula, the last two of which have been proposed as full species by several authors. We carried out a phylogenetic analysis of the giant honey bees using mitochondrial cox1 and cox2 gene sequences analyzed with maximum likelihood methods. We obtained strong support for four clades within A. dorsata in the broad sense: the three subspecies or species mentioned above, and a fourth lineage from south India. However, our analysis did not resolve the phylogenetic relationships among the four lineages. The presence of two genetically distinguishable groups of “A. dorsata” in India parallels the presence there of two cavity-nesting honey bees, A. cerana cerana and A. c. indica (the black hill bees and yellow plains bees, respectively). This suggests that past climatic or geological events may have temporarily isolated Indian populations from populations of the Asian mainland, leading to divergence and possibly speciation of Indian giant and cavity-nesting bees, followed by recolonization of India by eastern Asian forms. Recognition of these distinct lineages is important for conservation planning, so that their individual distributions, ecologies, and migration patterns can be considered, and so that the genetic diversity they represent can be maintained.
Wonder-Full Hearts: Awe Turns Children into Caring Champions
Authors: Stamkou Eftychia , Keltner Dacher
Published: July 2024

Have you ever exclaimed “Wow!” when looking at the stars, fireworks, or rainbows? This is the magical feeling of awe. Awe makes us feel small in a big world full of mysteries. Awe makes us focus on things other than just ourselves. Could awe make children more caring and helpful to other people? We tested this idea in two experiments. We showed children movie clips that made them feel awe, happiness, or nothing special. We found that children who felt awe became more helpful and caring. They counted more food items for a food drive for refugees and were also more likely to give away their chocolate treats or museum tickets to refugees. They even had a special change in their heart rates and breathing patterns. This bodily change made them feel more relaxed and connected to others. Awe is an amazing force because it makes kids kinder!
Border villages and the suffering of Kolberi: focus on Kolbers mothers’ narratives of their children’s Kolberi experience
Authors: Daneshmehr Hossein , Khaleghpanah Kamal , Sobhani Parviz , Rostami Susan
Published: June 2024

Introduction

The present research investigates the activity of Kolberi in the border villages of western and northwestern Iran, specifically in the Kurdish area of Nosud in Kermanshah province. Kolberi, a form of labor in these regions, subjects individuals to severe risks, including painful death or lifelong physical injuries, bringing considerable suffering and hardships to the Kolbers and their families. This study explores the narratives of Kolbers’ mothers regarding their children’s Kolberi experiences through Pierre Bourdieu’s theoretical framework of social suffering.

Methods

This qualitative study employs interpretive phenomenology to examine the lived experiences of mothers in the Nosud border area. Twenty-two Kolbers’ mothers were selected using purposive sampling. Data collection was conducted through semi-structured interviews and participant observation, continuing until theoretical saturation was achieved.

Results

Content analysis of the interviews revealed eight basic themes: (1) occurrence and aggravation of physical and mental complications, (2) reproduction of poverty and misery, (3) marginalization of the field of education in border areas, (4) emergence of structural determinism alongside environmental determinism, (5) weakening of the social status of Kolbers, (6) Kolber and bare life, (7) structural dehumanization of Kolber’s position, and (8) unique experiences of mothers regarding Kolberi.

Discussion

The findings highlight the unique and often neglected experiences of mothers related to Kolberi, emphasizing the economic struggles in Iran’s border areas. These experiences unveil hidden aspects of Kolberi, suggesting potential avenues for further research and contributing to the revitalization of activism among Kolbers’ mothers in border regions. The study underscores the importance of addressing the socio-economic conditions that perpetuate Kolberi and its associated sufferings.
Menstrual cycle tracking in professional volleyball athletes
Authors: Roffler Andrea , Fleddermann Marie-Therese , de Haan Hanna , Krüger Karsten , Zentgraf Karen
Published: June 2024

Introduction

The menstrual cycle may affect well-being and physical performance of elite female athletes by interfering with the function of multiple physiological systems. The aim of this study was to characterize the symptoms of the menstrual cycle and their frequency in elite female volleyball players.

Methods

Twenty professional female volleyball players were instructed to track their menstrual symptoms over the course of the first German national league season using the FitrWoman® tracking app. The app recorded the cycle length, duration, and intensity of the period as well as the occurrence and frequency of frequent cycle symptoms. The reported symptoms were then categorized into four categories (frequently, sometimes, rare, never) in order to create an individual Menstrual Symptom index (MSi) for each athlete.

Results

The most frequently occurring symptoms among all players without hormonal contraception (non-HC; n = 15) were “stomach cramps” (n = 15), “sleep disturbances” (n = 11), and “tiredness” (n = 11). The average number of symptoms counted per cycle was 11.8 (±17.7) and the average calculated MSi within the team was 12.9 (±10.7) points for non-HC users. The HC players (n = 4) also regularly experienced symptoms such as “sleep disturbances” or “tendered breasts”. The most common symptoms “stomach cramps” and “disturbed sleep” occurred more frequently during menstruation, while symptoms such as “bloating”, “cravings” or “tendered breasts” did also peak before menstruation.

Discussion

Menstrual cycle symptoms can be highly individual within a professional sports team. The calculation of the MSi seems to be a simple and accessible method to describe and overview the intensity and prevalence of symptoms in top female athletes in sports games.
The role of branched-chain amino acids and their downstream metabolites in mediating insulin resistance
Authors: Abdualkader Abdualrahman Mohammed , Karwi Qutuba G. , Lopaschuk Gary D. , Al Batran Rami
Published: June 2024

Elevated levels of circulating branched-chain amino acids (BCAAs) and their associated metabolites have been strongly linked to insulin resistance and type 2 diabetes. Despite extensive research, the precise mechanisms linking increased BCAA levels with these conditions remain elusive. In this review, we highlight the key organs involved in maintaining BCAA homeostasis and discuss how obesity and insulin resistance disrupt the intricate interplay among these organs, thus affecting BCAA balance. Additionally, we outline recent research shedding light on the impact of tissue-specific or systemic modulation of BCAA metabolism on circulating BCAA levels, their metabolites, and insulin sensitivity, while also identifying specific knowledge gaps and areas requiring further investigation. Finally, we summarize the effects of BCAA supplementation or restriction on obesity and insulin sensitivity.
Deglobalisation and Decoupling Tendencies in the Visegrád Countries in the Wake of the Polycrisis
Authors: Ginter Tamás , Tischler Patrik
Published: June 2024

After a number of shocks (including the Covid-19 pandemic and the war in Ukraine, in particular), global trade has undergone a transformation that is characterised by deglobalisation and decoupling tendencies. In this paper, we use descriptive statistics to analyse the short-term effects of exogenous shocks on international trade in the Visegrád countries. We find that between 2019 and 2022, deglobalisation tendencies were not persistent in the region. The trade-to-GDP ratio has exceeded the prepandemic levels (thus, the region is more globalised than in 2019), despite shortterm declines induced by the various shocks. While the region trades mainly with politically-economically aligned partners, the proportion of international trade with non-Western partners has also grown over the past four years. Trade with Russia has declined significantly since the outbreak of the war in Ukraine, but decoupling from China has not started. However, certain country differences apply.
Fixed-Time Adaptive Neural Network-Based Trajectory Tracking Control for Workspace Manipulators
Authors: Chen Xiaofei , Zhao Han , Zhen Shengchao , Liu Xiaoxiao , Zhang Jinsi
Published: July 2024

This paper proposes a novel neural network-based control algorithm with fixed-time performance constraints for manipulator systems in workspaces. The algorithm efficiently controls the manipulator’s trajectory tracking by tuning a preset performance function, thereby optimizing both speed and accuracy within a fixed timeframe. Initially, a tangent-type error transformation, applied through homogeneous embryonic transformation, ensures rapid convergence of tracking errors to a specific region. Subsequently, integrating a predetermined control strategy into the fixed-time stability framework ensures the system’s state reaches a defined boundary within a finite period. Lastly, neural networks are employed to approximate dynamic parameters and adjust the controller, achieving optimal parameter approximation and significantly enhancing trajectory tracking robustness. Simulation analyses and comparisons confirm the controller’s effectiveness and superiority in enhancing both the transient and steady-state performance of the control system.
Fault Detection of Multi-Wheeled Robot Consensus Based on EKF
Authors: Jouili Afrah , Boussaid Boumedyen , Zouinkhi Ahmed , Abdelkrim M. N.
Published: July 2024

Synchronizing a network of robots in consensus is an important task for cooperative work. Detecting faults in a network of robots in consensus is a much more important task. In considering a formation of Wheeled Mobile Robots (WMRs) in a master–slave architecture modeled by graph theory, the main objective of this study was to detect and isolate a fault that appears on a robot of this formation in order to remove it from the formation and continue the execution of the assigned task. In this context, we exploit the extended Kalman filter (EKF) to estimate the state of each robot, generate a residual, and deduce whether a fault exists. The implementation of this technique was proven using a Matlab simulator.
Trajectory Approximation of a Low-Performance E-Sail with Fixed Orientation
Authors: Quarta Alessandro A. , Mengali Giovanni
Published: July 2024

The Electric Solar Wind Sail (E-sail) is a propellantless propulsion system that converts solar wind dynamic pressure into a deep-space thrust through a grid of long conducting tethers. The first flight test, needed to experience the true potential of the E-sail concept, is likely to be carried out using a single spinning cable deployed from a small satellite, such as a CubeSat. This specific configuration poses severe limitations to both the performance and the maneuverability of the spacecraft used to analyze the actual in situ thruster capabilities. In fact, the direction of the spin axis in a single-tether configuration can be considered fixed in an inertial reference frame, so that the classic sail pitch angle is no longer a control variable during the interplanetary flight. This paper aims to determine the polar form of the propelled trajectory and the characteristics of the osculating orbit of a spacecraft propelled by a low-performance spinning E-sail with an inertially fixed axis of rotation. Assuming that the spacecraft starts the trajectory from a parking orbit that coincides with the Earth’s heliocentric orbit and that its spin axis belongs to the plane of the ecliptic, a procedure is illustrated to solve the problem accurately with a set of simple analytical relations.
A Time Series Prediction-Based Method for Rotating Machinery Detection and Severity Assessment
Authors: Zhang Weirui , Sun Zeru , Lv Dongxu , Zuo Yanfei , Wang Haihui , Zhang Rui
Published: July 2024

Monitoring the condition of rotating machinery is critical in aerospace applications like aircraft engines and helicopter rotors. Faults in these components can lead to catastrophic outcomes, making early detection essential. This paper proposes a novel approach using vibration signals and time series prediction methods for fault detection in rotating aerospace machinery. By extracting relevant features from vibration signals and using prediction models, fault severity can be effectively quantified. Our experimental results show that the proposed method has potential in early fault detection and is applicable to various types of bearing faults and the different statuses of these faults under complex running conditions, achieving very good generalization ability.
Lessons Learned in Designing a Proposed Ultraviolet Sterilization System for Space
Authors: Hughes David W. , Cataldo Giuseppe , Pellerano Fernando A. , Hardwick Terra C. , Micalizzi Frankie , Chambers Victor J. , Bean Brian R. , Braley Berton J. , Cook William B. , Day Ratna , Emmett Thomas J. , Hovis Clark D. , Ioana Stefan , Johnstone Dillon E. , Kaur Amandeep , Morgenstern Wendy M. , Nicolaeff Nicholas M. , Ong Lawrence , Seals Len , Schnurr Richard G. , Seide Laurie L. , Shaw George B. , Smith Kevin A. , Ta Oscar , Thomes William J. , Yum Honam
Published: July 2024

This paper presents a number of lessons learned while designing a proposed sterilization system for Mars Sample Return. This sterilization system is needed to inactivate any potentially hazardous Mars material on the exterior surface of the vessel containing sealed sample tubes filled with Mars rock cores, regolith and atmosphere. These returned samples would provide information on the geologic history of Mars, the evolution of its climate and the potential for ancient life. Mars Sample Return is categorized at Planetary Protection Category V Restricted Earth Return, so it is required to protect the Earth–Moon system from the biological impact of returning samples from Mars to Earth. This article reviews lessons learned in the development of a particular engineering implementation to support the protection of the Earth–Moon biosphere: the use of in situ ultraviolet LED illumination. The details of the biological efficacy of this approach or the policy-related impacts are outside of the scope of this manuscript. The lessons learned presented here include establishing design requirements for the system, the selection of a light source, optical design options, contamination control and approaches to thermal and power management.
Data-Driven-Method-Based Guidance Law for Impact Time and Angle Constraints
Authors: Cao Wenjie , Huang Jia , Chang Sijiang
Published: July 2024

To increase the hit efficiency and lethality of a flight vehicle, it is necessary to consider the vehicle’s guidance law concerning both impact time and angle constraints. In this study, a novel and straightforward impact time and angle control guidance law that is independent of time-to-go and small angle approximations is proposed with two stages using a data-driven method and proportional navigation guidance. First, a proportional navigation guidance-based impact angle control guidance law is designed for the second stage. Second, from various initial conditions on the impact angle control guidance simulation with various initial conditions, the input and output datasets are obtained to build a mapping network. Using the neural network technique, a mapping network model that can output the ideal flight path angle in flight is constructed for impact time control in the first stage. The proposed impact time and angle control guidance law reduces to the proportional navigation guidance law when the flight path angle error converges to zero. The simulation results show that the proposed guidance law delivers excellent performance under various conditions (including cooperative attack) and features better acceleration performance and less control energy than does the comparative impact time and angle control guidance law. The results of this research are expected to supplement those exploring various paradigms to solve the impact time and angle control guidance problem, as concluded in the current literature.
Data Envelopment Analysis (DEA) to Estimate Technical and Scale Efficiencies of Smallholder Pineapple Farmers in Ghana
Authors: Boakye Kwaku , Lee Yu-Feng , Annor Festus F. , Dadzie Samuel K. N. , Salifu Iddrisu
Published: July 2024

This study focuses on evaluating the technical and scale efficiencies of smallholder pineapple farmers in Ghana’s Central Region. We surveyed 320 participants selected using random sampling and applied an input-oriented Data Envelopment Analysis (DEA) method to gauge their technical, pure, and scale efficiencies. Our findings indicate that the mean technical efficiency among these farmers is 0.505, with individual scores ranging from 0.079 to 1.000. Notably, 90.82% of the farmers are operating below maximum efficiency levels, suggesting a potential input reduction of up to 49.5% while maintaining current production levels. Relaxing the assumption of constant returns under Variable Returns to Scale (VRS) conditions reveals a notable improvement in technical efficiency, with 10.82% more farmers achieving optimal efficiency levels. Furthermore, our analysis highlights scale inefficiencies, with 67.26% of farmers operating below optimal scale levels. By increasing production by 22.8%, these scale-inefficient farmers could enhance their efficiency and productivity within existing technological frameworks. These findings underscore the importance of collaborative efforts among policymakers, practitioners, and stakeholders within the agricultural value chain to implement interventions such as improving access to technology and innovation for smallholder farmers and making necessary investments in farmer education and training programs to enhance both technical and scale efficiencies in Ghana’s pineapple sector. Such initiatives can drive sustainable growth, improve farmers’ livelihoods, and bolster the sector’s overall competitiveness.
Biodiversity and Vegetation Succession in Vineyards, Moravia (Czech Republic)
Authors: Hurajová Erika , Martínez Barroso Petra , Děkanovský Igor , Lumbantobing Yentriani Rumeta , Jiroušek Martin , Mugutdinov Amir , Havel Ladislav , Winkler Jan
Published: July 2024

Maintaining biodiversity in agricultural landscapes is a major challenge for environmental protection in Europe. Vineyards rely heavily on agrotechnical interventions such as herbicide use and tillage for weed control, which affect biodiversity and can lead to soil erosion and resistant weed populations. The fragmentation of agricultural landscapes affects biodiversity by altering community composition and often reducing plant population sizes and genetic diversity. However, it can also increase the abundance of certain species and enhance population resilience to environmental change. Vineyards can support high levels of biodiversity and provide ecosystem services due to their semi-natural habitat structure. This research evaluates vegetation biodiversity using phytosociological relevés in different vineyards. Our results show that species richness and biodiversity are significantly influenced by vineyard age and management type. This study highlights differences in the representation of plant functional groups, with perennial taxa in grassy inter-row contributing to anti-erosion functions and serving as food sources for pollinators. The root zone around vine trunks shows an increase in invasive species with vineyard age, posing a risk to the agroecosystem. Vineyards predominantly follow a ruderal ecological strategy, using nutrients and light efficiently, while tolerating management disturbances. Understanding these dynamics is critical for developing sustainable vineyard management practices that support biodiversity and ecological resilience, counteract the homogenization of agricultural landscapes, and promote the coexistence of viticulture and species-rich ecosystems.
A Novel Two-Stage Approach for Automatic Extraction and Multi-View Generation of Litchis
Authors: Li Yuanhong , Wang Jing , Liang Ming , Song Haoyu , Liao Jianhong , Lan Yubin
Published: July 2024

Obtaining consistent multi-view images of litchis is crucial for various litchi-related studies, such as data augmentation and 3D reconstruction. This paper proposes a two-stage model that integrates the Mask2Former semantic segmentation network with the Wonder3D multi-view generation network. This integration aims to accurately segment and extract litchis from complex backgrounds and generate consistent multi-view images of previously unseen litchis. In the first stage, the Mask2Former model is utilized to predict litchi masks, enabling the extraction of litchis from complex backgrounds. To further enhance the accuracy of litchi branch extraction, we propose a novel method that combines the predicted masks with morphological operations and the HSV color space. This approach ensures accurate extraction of litchi branches even when the semantic segmentation model’s prediction accuracy is not high. In the second stage, the segmented and extracted litchi images are passed as input into the Wonder3D network to generate multi-view of the litchis. After comparing different semantic segmentation and multi-view synthesis networks, the Mask2Former and Wonder3D networks demonstrated the best performance. The Mask2Former network achieved a mean Intersection over Union (mIoU) of 79.79% and a mean pixel accuracy (mPA) of 85.82%. The Wonder3D network achieved a peak signal-to-noise ratio (PSNR) of 18.89 dB, a structural similarity index (SSIM) of 0.8199, and a learned perceptual image patch similarity (LPIPS) of 0.114. Combining the Mask2Former model with the Wonder3D network resulted in an increase in PSNR and SSIM scores by 0.21 dB and 0.0121, respectively, and a decrease in LPIPS by 0.064 compared to using the Wonder3D model alone. Therefore, the proposed two-stage model effectively achieves automatic extraction and multi-view generation of litchis with high accuracy.
The Integration of Mechanical Energy Absorbers into Rollover Protective Structures to Improve the Safety of Agricultural Tractors in the Event of Rollover
Authors: Alfaro-Lopez José R. , Perez-Ezcurdia Amaya , Latorre-Biel Juan-Ignacio , Arana-Navarro Ignacio , Benito-Amurrio Marta , Villanueva-Roldán Pedro
Published: July 2024

The combination of safety belts and rollover protective structures (ROPSs) is key in improving the safety of agricultural tractors in the event of rollover. However, we also have the opportunity to enhance the security provided by each ROPS; one such example is the combination of this safety device with adequate mechanical energy absorbers (MEAs). Inexpensive disc-shaped MEAs can be included in the anchoring points of a ROPS onto the chassis of a tractor. Three configurations of ROPS combined with MEAs were tested during the application of loads that simulated the effects of side rollover in the vehicle. The tested configurations included a blank MEA as a reference case alongside a single MEA and a stack assembly containing both elements. The results of the tests show that both the deformation of the ROPS itself and the strain energy are larger in the case of blank MEAs; thus, there is also a risk that the clearance zone will be infringed upon and that the protective structure will collapse. We can conclude that the implementation of an appropriate MEA in ROPS reduces the deformation of the ROPS itself and its strain energy in cases of vehicle rollover; hence, the safety provided by such protection systems may be improved at a low cost.
Nutritional Value Evaluation of Corn Silage from Different Mesoregions of Southern Brazil
Authors: Neumann Mikael , Baldissera Ellen , Alessi Ienke Livia , Martins de Souza André , Piemontez de Oliveira Paulo Eduardo , Harry Bumbieris Junior Valter
Published: July 2024

Corn silage is widely used in livestock farming; however, its quality is easily altered, and one of the factors that has a high influence in this regard is the region of production. The objective was to evaluate the chemical–bromatological composition of 498 samples of corn silage from mesoregions in Southern Brazil during the 2022/2023 summer harvest. The following were studied in relation to our objective: nutritional composition, dry matter, mineral matter, ether extract, starch, crude protein, neutral detergent fiber, acid detergent fiber, acid detergent lignin, total digestible nutrients, total carbohydrates, and fractions of carbohydrates. The silages from Central South-PR had higher levels of starch and ether extract (30.68% ± 6.24% and 3.41% ± 0.92%, respectively), whereas in West-SC, the silages had higher levels in the A + B1 fraction of carbohydrates (49.59% ± 6.34%). Silages in North-PR had higher concentrations of neutral detergent fiber and acid detergent fiber (49.86% ± 5.92% and 29.70% ± 4.38%, respectively), while in Northwest-RS and West-PR, silages had higher levels of the B2 carbohydrate fractions (46.25% ± 1.98% and 44.55% ± 3.84%, respectively). The nutritional composition differences presented were due to the variables of each mesoregion, interfering in the scenario of formulating diets and animal nutrition.