Browse Articles

Liquid flows induced in a rotating drum with different fill ratios

Abstract In the present study, we experimentally investigate the liquid flow induced in a rotating drum (cylindrical tank with a short aspect ratio) aligned horizontally, focusing on the variation in the time-averaged and fluctuating flow structures with different fill ratios. For each fill ratio, controlled by varying the water height, we measure the velocity fields at different cross-sectional planes with particle image velocimetry while varying the rotational speed of the drum. Compared to the condition of a fill ratio of 1.0, in which the liquid inside the drum rotates forming a large-scale (solid-body rotation) organized flow structure, a substantial asymmetric flow structure shows up in partially-filled conditions driven by the imbalance between (i) the momentum diffusion along the radial direction and the centrifugal acceleration, and (ii) the downward (gravitational) flux of the induced flow. In addition to the mean flow structure, we examine the fluctuating velocity fields together with the dynamics of the free surface, and we also briefly discuss the difference between the liquid flow and granular (particle) flow in a partially-filled drum. We think that the present results provide valuable insights on the partially-filled liquid drum toward various engineering applications.

Retraction Note: Thermal cooling efficacy of a solar water pump using Oldroyd-B (aluminum alloy-titanium alloy/engine oil) hybrid nanofluid by applying new version for the model of Buongiorno

Assessment of mechanical properties and durability of compressed mud bricks stabilized with stone dust, wheat straw, and cement

The interaction of <i>Serratia</i> bacteria and harmonine in harlequin ladybird confers an interspecies competitive edge

The harlequin ladybird, Harmonia axyridis , is a predatory beetle used globally to control pests such as aphids and scale insects. Originating from East Asia, this species has become highly invasive since its introduction in the late 19th century to Europe and North America, posing a threat to local biodiversity. Intraguild predation is hypothesized to drive the success of this invasive species, but the underlying mechanisms remain unknown. In this study, a feeding assay revealed that while harlequin ladybirds survive feeding on seven-spotted ladybird eggs, the reverse is not true. However, seven-spotted ladybirds that had fed on harlequin ladybird eggs were able to survive the feeding assay when treated with penicillin. Microbiome sequencing and whole genome analysis of harlequin ladybird eggs revealed a newly discovered pathogenic bacterium strain named Serratia harmoniae. The median lethal concentration (LC50) of S. harmoniae was found to be 2.1 × 10 5 times higher in the harlequin ladybird compared to the seven-spotted ladybird. The high tolerance observed in harlequin ladybirds was attributed to harmonine, specifically produced in the fat body of this species. Silencing three key genes in the harmonine biosynthesis pathway— Spidey , Sca2 , and Desat— reduced the production of the compound, leading to increased S. harmoniae levels and higher mortality. Treating RNAi-altered individuals with penicillin reversed this effect, successfully reducing S. harmoniae presence and increasing insect survival. Taken together, these findings demonstrate that S. harmoniae , a newly identified pathogenic bacterium carried by harlequin ladybirds, interacts with harmonine to confer an interspecies competitive advantage over native ladybird species in nonnative regions.

Dynamic treeline and cryosphere response to pronounced mid-Holocene climatic variability in the US Rocky Mountains

Climate-driven changes in high-elevation forest distribution and reductions in snow and ice cover have major implications for ecosystems and global water security. In the Greater Yellowstone Ecosystem of the Rocky Mountains (United States), recent melting of a high-elevation (3,091 m asl) ice patch exposed a mature stand of whitebark pine ( Pinus albicaulis ) trees, located ~180 m in elevation above modern treeline, that date to the mid-Holocene (c. 5,950 to 5,440 cal y BP). Here, we used this subfossil wood record to develop tree-ring-based temperature estimates for the upper-elevation climate conditions that resulted in ancient forest establishment and growth and the subsequent regional ice-patch growth and downslope shift of treeline. Results suggest that mid-Holocene forest establishment and growth occurred under warm-season (May-Oct) mean temperatures of 6.2 °C (±0.2 °C), until a multicentury cooling anomaly suppressed temperatures below 5.8 °C, resulting in stand mortality by c. 5,440 y BP. Transient climate model simulations indicate that regional cooling was driven by changes in summer insolation and Northern Hemisphere volcanism. The initial cooling event was followed centuries later (c. 5,100 y BP) by sustained Icelandic volcanic eruptions that forced a centennial-scale 1.0 °C summer cooling anomaly and led to rapid ice-patch growth and preservation of the trees. With recent warming (c. 2000–2020 CE), warm-season temperatures now equal and will soon exceed those of the mid-Holocene period of high treeline. It is likely that perennial ice cover will again disappear from the region, and treeline may expand upslope so long as plant-available moisture and disturbance are not limiting.

Effect of the PakCat program on nutrition status, dietary pattern and nutrition knowledge and skills of Pakistani women living in Catalonia evaluated by a mixed-method randomized control trial (RCT)

Background Pakistani women are among the most affected groups by obesity and heart failure in Catalonia. Due to cultural and linguistic barriers, their participation in standard health promotion programs is limited. To address this issue, we implemented a culturally and linguistically appropriate food education program called the PakCat Program. Methods The study employed a community-based participatory research (CBPR) design, utilizing a two-arm, cluster-assignment, non-blinded mixed-method randomized control trial (RCT) implemented in Badalona and Santa Coloma de Gramenet, two neighboring municipalities with a substantial Pakistani population. Participants were randomly assigned to the control group (n = 67) and the intervention group (n = 70). The intervention group received ten weekly culturally and linguistically appropriate food education sessions over ten weeks, while the control group attended three general sessions. The main outcome measures included nutritional status, nutrition knowledge and skills, dietary patterns, and satisfaction with the intervention, which were assessed pre-and post-intervention combining quantitative methods based on a survey and qualitative approaches consisting of conducting focus group discussions (FGDs). Results The quantitative analysis conducted through a two-factor analysis of variance (ANOVA) for repeated measures indicated a significant improvement in the study variables across the entire sample (p &lt; 0.001 within group), with the intervention group experiencing greater improvements in nutrition knowledge and skills and dietary pattern (p &lt;0.001 for interaction and between groups). These findings were corroborated by thematically analyzed qualitative data confirming a more pronounced improvement in the study outcomes of the intervention group. Furthermore, both groups reported a high level of satisfaction with the intervention. Conclusions The PakCat Program effectively improved the nutrition knowledge, skills, and dietary patterns of immigrant women of Pakistani origin residing in Catalonia. However, future research involving a larger sample size and combining the behavioral and clinical parameters is needed to enhance the generalizability of the results.

DCFE-YOLO: A novel fabric defect detection method

Accurate detection of fabric defects is crucial for quality control in the textile industry. However, the task of fabric defect detection remains highly challenging due to the complex textures and diverse defect patterns. To address the issues of inaccurate localization and false positives caused by complex textures and varying defect sizes, this paper proposes an improved YOLOv8-based fabric defect detection method. First, Dynamic Snake Convolution is introduced into the backbone network to enhance sensitivity to elongated and subtle defects, improving the extraction of edge and texture details. Second, a Channel Priority Convolutional Attention mechanism is incorporated after the Spatial Pyramid Pooling layer to enable more precise defect localization by leveraging multi-scale structures and channel priors. Finally, the feature fusion network integrates Partial Convolution and Efficient Multi-scale Attention, optimizing the fusion of information across different feature levels and spatial scales, which enhances the richness and accuracy of feature representations while reducing computational complexity. Experimental results demonstrate a significant improvement in detection performance. Specifically, mAP@0.5 increased by 2.9%, precision improved by 3.5%, and mAP@0.5:0.95 rose by 2.3%, highlighting the model’s superior capability in detecting complex defects. The project is available at https://github.com/lilian998/fabric.

Classification and spatial characteristics of different development stages in China: Evidence from the contribution rate of production factors

This paper aims to reveal the changing characteristics of the contribution rates of different production factors in China since the reform and opening up from two dimensions: stage and space. The study used national data from 1978 to 2021 and provincial data from 2000 to 2020, combined with methods such as C-D production function and spatial econometrics for analysis. Research has found that: (1) In terms of stage characteristics, during the structural adjustment stage (1978–1998), economic growth mainly relies on capital and labor input, and the contribution rate of land factors gradually decreases. During the high-speed development stage (1998–2012), the contribution rate of technological factors gradually increased, while the contribution rate of land factors remained relatively stable. In the stage of high-quality development (2012 present), the contribution rate of technological factors continued to rise and become the dominant factor, while the contribution rate of land factors has decreased to a lower level. (2) Regarding spatial characteristics, the spatial econometric model reveals significant spatial agglomeration characteristics of capital and labor, and land factors positively affect local and neighboring economic growth. From 2000 to 2020, the contribution rate of capital factors in various provinces showed a difference of "low in the east and high in the west," which decreased year by year. The contribution rates of labor and land factors have declined to low levels in all provinces; The contribution rate of technological elements has significantly increased, with a higher contribution rate in the southeast region; High-quality development progress in each province can be identified based on the contribution rates of different production factors. The research findings help to understand the impact of varying production factors on economic development at a temporal and spatial scale and provide a scientific basis for achieving a high-quality development pattern of rational allocation of factors and regional coordinated development.

Concomitant formation of protocells and prebiotic compounds under a plausible early Earth atmosphere

Revealing the origin of life and unambiguously detecting fossil remains of the earliest organisms are closely related aspects of the same scientific research. The synthesis of prebiotic molecular building blocks of life and the first compartmentalization into protocells have been considered two events apart in time, space, or both. We conducted lightning experiments in borosilicate reactors filled with a mixture of gases mimicking plausible geochemical conditions of early Earth. In addition to the variety of prebiotic organic molecules synthesized in these experiments, we investigated the micrometer-thick silica-induced organic film that covers the walls of the reactors and floats at the water–gas interface. We found that the film is formed by aggregation of HCN-polymer nanoclusters whenever water is present, either in the liquid or vapor phase. The organic film morphs into micrometer-scale biomorphic vesicular structures hanging from the organic film into the water. We also show that these structures are hollow and may act as microreactors facilitating chemical pathways toward increasing complexity. We propose that these organic biomorphs form through a bubble-driven mechanism and interfacial precipitation of HCN-polymers. The concomitant synthesis of biomorphic poly-HCN protocells and prebiotic molecules under plausible geochemical conditions of early Earth-like planets and moons and opens a different geochemical scenario for the emergence of life. Our results suggest that the coexistence of molecular building blocks of life and submicron biomorphic structures in the oldest rocks on Earth or any other celestial body does not necessarily mean evidence of life.

A prospective observational study on persistent postoperative pediatric pain, 4P: The study protocol

Background Access to adequate pain treatment is a fundamental right, yet international data suggest that a considerable number of children experience acute and persistent pain. Little is known about the occurrence of both acute and persistent pain in children. The incidence of persistent postoperative pain in children is an unexplored area but international studies suggest that many children experience long-term pain after surgery, with a major impact on daily life. In 4P, Persistent Postoperative Pediatric Pain, we want to estimate the incidence of acute and persistent postoperative pediatric pain. The European Society for Paediatric Anaesthesiology has developed guidelines for perioperative pain management. We aim to examine how well these guidelines are followed and whether adherence to guidelines influences the pain experienced after surgery. Method 4P is a prospective observational study of children aged 1–17, planned for surgery in southern Sweden 2023–2024. After agreement from all caregivers, data concerning preoperative pain, pre-emptive analgesia, perioperative management and postoperative pain will be collected. Via an electronic management software, pain will be evaluated at home (or in hospital) at 24h, 3, 6 and 12 months after surgery. We will include 1000 patients. Discussion 4P will prospectively follow a large number of children after general pediatric surgeries and evaluate the occurrence of postoperative pain, both acute (APOP) and persistent (PPOP). The study will assess pain treatment regimens and identify risk factors associated with the development of acute and persistent pediatric postoperative pain. Trial registration Prospectively posted at ClinicalTrials.gov, identifier NCT06035042.

Asynchronous effects of heat stress on growth rates of massive corals and damselfish in the Red Sea

Climate change is imposing multiple stressors on marine life, leading to a restructuring of ecological communities as species exhibit differential sensitivities to these stressors. With the ocean warming and wind patterns shifting, processes that drive thermal variations in coastal regions, such as marine heatwaves and upwelling events, can change in frequency, timing, duration, and severity. These changes in environmental parameters can physiologically impact organisms residing in these habitats. Here, we investigate the synchrony of coral and reef fish responses to environmental disturbance in the Red Sea, including an unprecedented combination of heat stress and upwelling that led to mass coral bleaching in 2015. We developed cross-dated growth chronologies from otoliths of 156 individuals of two planktivorous damselfish species, Pomacentrus sulfureus and Amblyglyphidodon flavilatus, and from skeletal cores of 48 Porites spp. coral colonies. During and immediately after the 2015 upwelling and bleaching event, damselfishes exhibited a positive growth anomaly but corals displayed reduced growth. Yet, after 2015–2016, these patterns were reversed with damselfishes showing a decline in growth and corals rebounding to pre-disturbance growth rates. Our results reveal an asynchronous response between corals and reef fish, with corals succumbing to the direct effects of heat stress, and then quickly recovering when the heat stress subsided—at least, for those corals that survived the bleaching event. Conversely, damselfish growth temporarily benefited from the events of 2015, potentially due to the increased metabolic demand from increased temperature and increased food supply from the upwelling event, before declining over four years, possibly related to indirect effects associated with habitat degradation following coral mortality. Overall, our study highlights the increasingly complex, often asynchronous, ecological ramifications of climate extremes on the diverse species assemblages of coral reefs.

The importance of organisational culture for health system resilience: A qualitative analysis of factors that supported health care workers in Germany during the COVID-19 pandemic

Health system resilience is defined as the ability of a system to prepare, manage, and learn from shocks. This study investigates the resilience of the German health system by analysing the system-related factors that supported health care workers, a key building block of the system, during the COVID-19 pandemic. We thematically analysed data from 18 semi-structured interviews with key informants from management, policy and academia, 17 in-depth interviews with health care workers, and 10 focus group discussions with health care workers. We identified six categories of factors which supported health care workers during the pandemic: (1) appreciation and encouragement; (2) team support and communication; (3) collaboration across professions and institutions; (4) informational, material and technical support; (5) leadership and participation; and (6) creativity and innovation. The analysis highlights the importance of systemic and organisational factors for maintaining health system resilience. The need to improvise and develop pragmatic solutions to deal with COVID-related challenges offered ample opportunities for participation, self-determination, innovation, and alternative work processes. Learning from adaptations made during the pandemic and implementing sustainable organisational and systemic changes to increase participation, conducive organisational cultures, and non-hierarchical working styles hold promising potential for health system transformation and health system strengthening.

A scoping review of interventions on middle school students’ attitudes towards science

The aim of the study was to review the scientific literature on educational interventions to promote positive attitudes towards science in middle school students. Due to the decline in positive attitudes towards science observed in this critical age group of students and the implementation of training programmes aimed at changing this situation, we sought to identify components of training proposals that have received attention from researchers. This paper presents a scoping review of 37 papers published in English and Spanish over the last 10 years. The review aims to describe the research outputs and analyse the effectiveness and characteristics of program interventions, drawing from various databases. The results show the need to examine the operational definition of the constructs used in the programmes, to focus attention on the influence of intrinsic variables on middle school students’ attitudes towards science, such as racial group or self-efficacy, and to conduct follow-up evaluations to assess the permanence of attitudes. While acknowledging limitations related to construct clarity or language restrictions in the search process the findings suggest that middle school students’ attitudes towards science remain an open area of research, as there is no consensus on the characteristics of effective programmes.

Research on the ordering strategy problem in supply chain with profit allocation under two-level price-fluctuation sales

This paper investigates optimal ordering strategies in supply chains under two-level price fluctuations and initial profit allocation. By utilizing Copula functions to model the complex relationship between fluctuating prices and uncertain demand, the study develops both continuous and discrete decision models for practical applications. A discrete algorithm is proposed to approximate the optimal solution, with its convergence rigorously proven. Numerical experiments demonstrate that profit allocation ratios significantly impact optimal order quantities and overall supply chain profit. Price fluctuations, particularly at the discount level, present critical challenges, necessitating flexible and adaptive ordering strategies. The study also investigates the influence of different Copula relationships on optimal ordering decisions, revealing how varying market conditions—from moderate price sensitivity to high volatility—affect optimal order quantities. By examining ordering strategies in the context of profit allocation contracts, this research offers a new perspective on how supply chain members can collaboratively navigate uncertain markets. The findings provide actionable insights for managers to mitigate risks, improve coordination, and seize new opportunities. Extending traditional models to incorporate price fluctuations and profit allocation, this study makes theoretical and practical contributions to supply chain management, offering robust strategies to strengthen supply chain resilience.

Illustration image style transfer method design based on improved cyclic consistent adversarial network

To improve the expressiveness and realism of illustration images, the experiment innovatively combines the attention mechanism with the cycle consistency adversarial network and proposes an efficient style transfer method for illustration images. The model comprehensively utilizes the image restoration and style transfer capabilities of the attention mechanism and the cycle consistency adversarial network, and introduces an improved attention module, which can adaptively highlight the key visual elements in the illustration, thereby maintaining artistic integrity during the style transfer process. Through a series of quantitative and qualitative experiments, high-quality style transfer is achieved, especially while retaining the original features of the illustration. The results show that when running on the Monet2photo dataset, when the system iterates to 72 times, the loss function value of the research method approaches the target value of 0.00. On the Horse2zebra dataset, as the sample size increases, the research method has the smallest FID value, and the value approaches 40.00 infinitely. With the change of peak signal-to-noise ratio, the accuracy of the research algorithm has been greater than 95.00%. Practical application found that the color of the image obtained by the research method is more gorgeous and the line features are more obvious. The above results all show that the research method has achieved more satisfactory results in the task of style transfer of illustration images, especially in terms of the accuracy of style transfer and the retention of image details.

Identifying depression subtypes and investigating their consistency and transitions in a 1-year cohort analysis

Major depressive disorder (MDD) is defined by an array of symptoms that make it challenging to understand the condition at a population level. Subtyping offers a way to unpick this phenotypic diversity for improved disorder characterisation. We aimed to identify depression subtypes longitudinally using the Inventory of Depressive Symptomatology: Self-Report (IDS-SR). A secondary analysis of a two-year cohort study called Remote Assessment of Disease and Relapse in Major Depressive Disorder (RADAR-MDD), which collected data every three months from patients with a history of recurrent MDD in the United Kingdom, the Netherlands, and Spain (N = 619). We used latent class and latent transition analysis to identify subtypes at baseline, determined their consistency at 6- and 12-month follow-ups, and examined transitions over time. We identified a 4-class solution: (1) severe with appetite decrease, (2) severe with appetite increase, (3) moderate severity and (4) low severity. These same classes were identified at 6- and 12-month follow-ups, and participants tended to remain in the same class over time. We found no statistically significant differences between the two severe subtypes regarding baseline clinical and sociodemographic characteristics. Our findings emphasize severity differences over symptom types, suggesting that current subtyping methods provide insights akin to existing severity measures. When examining transitions, participants were most likely to remain in their respective classes over 1-year, indicating chronicity rather than oscillations in depression severity. Future work recommendations are made.

Integrating intuitionistic fuzzy and MCDM methods for sustainable energy management in smart factories

Improving energy efficiency is crucial for smart factories that want to meet sustainability goals and operational excellence. This study introduces a novel decision-making framework to optimize energy efficiency in smart manufacturing environments, integrating Intuitionistic Fuzzy Sets (IFS) with Multi-Criteria Decision-Making (MCDM) techniques. The proposed approach addresses key challenges, including reducing carbon footprints, managing operating costs, and adhering to stringent environmental standards. Eight essential criteria are identified, such as the use of renewable energy, the efficiency of production, and the health and safety of workers, to evaluate energy performance. Using the entropy method for criterion weighting and the CRADIS technique for alternative ranking, we prioritize a range of energy-efficient solutions. The novelty of our approach lies in its comprehensive assessment of complex real-world energy management scenarios within smart factories, offering a robust and adaptable decision-support tool. Our empirical results, validated through sensitivity analysis, show that alternative 5 delivers the most significant improvement in energy efficiency. This study provides valuable information for industry practitioners seeking to transition to more sustainable production methods and supports the broader sustainability agenda.

Saffron’s protective role against atherosclerosis-induced cataract progression in New Zealand white rabbits with phytochemical analysis of saffron’s extract

Cataracts are significant causes of blindness, closely linked to prolonged hypercholesterolemia. While saffron has the potential for eye health, its effects on lens lesions remain understudied. This study aimed to investigate the effect of saffron on the lens changes in atherosclerotic-induced New Zealand white rabbits (NZWR). Thirty-five NZWRs were subjected to four to eight weeks of high-cholesterol diet to induce atherosclerosis, resulting in cataractous lens changes. The rabbits were categorised randomly into three groups: normal diet group, pre-treated group and treated group. The pre-treated group was divided into early atherosclerosis(HC4) and established atherosclerosis (HC8). The saffron-treated group was fed with the HCD diet followed by saffron treatment of 50mg/kg/day (TG450, TG840) and 100mg/kg/day (TG4100, TG8100) of saffron ethanolic extract (SEE) respectively. The normal diet group was given a normal diet over the 8 weeks. After completing the 16-week experimental protocol, the NZWR were euthanized, and their lenses were extracted for histopathological evaluation. The pre-treated group exhibited cataractous lens changes of grade 2, characterized by increased homogenisation, swollen lens fibers, and intracellular vacuolisation. Interestingly, these cataract changes showed a positive trend from grade 2 to grade 1 post-treatment with SEE. In the saffron-treated group, vacuoles and pinkish homogenised areas were reduced. Additionally, a uniform layer of anterior epithelium and decreased non-swollen lens fibers indicated significant cataract lesion improvement. The normal diet group displayed minimal to zero cataractous changes (Grade 0). HPLC analysis demonstrated the presence of crocin, crocetin, and picocrocin in the saffron ethanolic extract, with peak absorptions at 440nm (12.817min), 440nm (1.620min), and 254nm (6.553min) respectively. The phytochemical screening of saffron ethanolic extract was conducted and showed the presence of phytochemical compounds including saponins, flavonoids, tannins, and steroids. The positive effects on lenses in the TG groups could be due to crocin and crocetin, bioactive components of saffron, and its phytochemical compounds. This study highlights saffron’s potential in managing cataract-induced conditions, emphasizing the importance of further research for its full therapeutic potential in cataract management.

Anti-inflammatory effects of moxifloxacin and levofloxacin on cadmium-activated human astrocytes: Inhibition of proinflammatory cytokine release, TLR4/STAT3, and ERK/NF-κB signaling pathway

Cadmium is a non-essential element and neurotoxin that causes neuroinflammation, which leads to neurodegenerative diseases and brain cancer. To date, there are no specific or effective therapeutic agents to control inflammation and alleviate cadmium-induced progressive destruction of brain cells. Fluoroquinolones (FQs), widely used antimicrobials with effective blood-brain barrier penetration, show promise in being repurposed as anti-inflammatory drugs. Therefore, we aimed to test the efficacy of repurposed FQs for the treatment of cadmium-induced inflammation using cultures of U-87 MG human astrocytes and primary human astrocytes. Both FQs abrogated cadmium-induced interleukin (IL)-6 and IL-8 release from human astrocytes in a concentration and time-dependent manner, although levofloxacin had a stronger inhibitory effect than moxifloxacin. The downregulation of inflammatory cytokine release occurred with a concomitant reduction in cadmium-induced elevations in p65 nuclear factor-κB (NF-κB) and extracellular signal-regulated kinases (ERKs) 1/2 phosphorylation. Additionally, levofloxacin treatment significantly alleviated cadmium-induced activation of phosphorylated NF-κB translocation and toll-like receptor (TLR)-4/signal transducer and activator of transcription (STAT) 3 signaling. Transcriptome analysis revealed that modulation of inflammation-related pathways was the most enriched after FQ treatment. Our data suggest that FQs, particularly levofloxacin, attenuate the inflammatory process mediated by cadmium in human astrocytes. These effects may be mediated, at least in part, by inhibition of immune pathways regulated by TLR4, STAT3, ERK MAPK, and NF-κB.

Boreal forests are heading for an open state

The boreal forest biome is warming four times faster than the global average. Changes so far are moderate, but time lags in responses may transiently maintain forest states which are no longer supported by current environmental conditions. Here, we explore whether tree cover dynamics hint at the state to which the biome may be shifting. Our results suggest that global boreal tree cover is heading for a unimodal state of open forest (30 to 50%), contrasting starkly to the bimodal distribution of dense forests (&gt;60%) and sparse woodlands (5 to 15%) found today. A future open forest in a warmer world would likely increase the risk of forest fires, leading to potentially substantial releases of stored carbon.