Search Results (22)

Meat quality characteristics are important economic traits of ducks. To identify the molecular bases of these traits, we performed an integrated multi-omics analysis (metabolomics, transcriptomics, and miRNAomics) that compared the breast muscle of 300-day-old Liancheng white duck (LD), which is a lean-type breed prized for its soup flavor, and traditional meat duck Cherry Valley duck (CD), which is a fast-growing fat-type breed used for roasting. The results show that LD had higher levels of amino and bile acids, while CD had higher levels of carbohydrates. Integration analysis revealed key breed-specific molecular signatures. In LD, upregulation of the amino acid transporters SLC7A6 and SLC6A9 related to amino acid transport was consistent with elevated intramuscular amino acids. For carbohydrate metabolism, SOCS3—a well-established negative regulator of glucose uptake in mammalian skeletal muscle—was significantly upregulated in LD, consistent with their lower intramuscular carbohydrate levels. SLC6A9 and SOCS3 were predicted to be negatively regulated by oan-miR-1386. In LD, upregulation of the bile acid biosynthesis gene CH25H paralleled the higher bile acid content, suggesting complex, tissue-specific regulation of these pathways. This integrated analysis provides a resource for candidate genes, miRNAs, and metabolic pathways underlying breed-specific meat quality traits in ducks. The findings generate testable hypotheses for future functional studies and offer potential molecular targets for breeding strategies aimed at improving poultry meat quality. Full article

We present new high-dispersion optical spectra of the planetary nebula NGC 2371 obtained with the Manchester Echelle Spectrometer at the OAN-SPM 2.1 m telescope, complemented with 3D morpho-kinematic modelling using ShapeX. The data reveal that the present-day morphology of NGC 2371 is the outcome of multiple episodic mass-loss events rather than a single outflow. Our best-fitting model simultaneously reproduces the direct images and the Position–Velocity (PV) diagrams, and consists of a barrel-shaped shell with younger polar caps, extended bipolar lobes, and a pair of misaligned low-excitation [N ii] knots interpreted as jet-like ejections. The derived kinematical ages of the main structures, spanning ≃1600 to ≃4400 yr, indicate successive episodes of mass loss with different geometries and timescales. The nearly perpendicular bipolar lobes, the absence of a pronounced waist, and the surface distortions of the large-scale structures cannot be explained solely by standard axisymmetric wind interactions. Instead, our results point to a combination of shaping agents, including a late thermal pulse (born-again scenario) possibly related to the H-deficient [WR]-type nature of the central star, binary-driven interactions, and episodic jet activity. NGC 2371 thus provides a particularly instructive case where multiple shaping agents may operate, and where some of the relevant physical processes remain only marginally explored in current models of PN formation and evolution. Full article

Set in the vocational education and training sector in England, this article draws attention to how top-down, centre–periphery approaches to curriculum design and development in vocational education fail for at least three reasons. First, they misconstrue the nature of knowledge. Second, they lead to perfunctory and fragmented approaches to curriculum design, coupled with mechanistic measures of quality and achievement, which often require little more than “one-off” and superficially assessed demonstrations of performance. Finally, they underplay the role and importance of the teacher as researcher and artist in putting the cultural resources of society to work in creative curriculum design and pedagogy. Teacher artistry is pivotal in animating and heightening the vitality of vocational curricula. It is through this artistry that teachers make theories, ideas and concepts in vocational subjects and disciplines accessible and meaningful to all learners in coherent ways in the contexts of their learning and their lives. The consequences of the epistemic faux pas underpinning centre-to-periphery models of curriculum design and development are highlighted in this article in vocational tutors’ accounts of experiences of problems and issues in curriculum design, development and assessment encountered in their practice. Participants in the research teach in a variety of vocational education settings, including Apprenticeships and Higher-Level Technical Education; English Language at General Certificate of Secondary Education (GCSE) level; Health and Social Care; Information and Communications Technology; Construction (Plumbing); Digital Production, Design and Development and High-Tech Precision Engineering. Data are analysed and reported through systematic, thematic analysis This article draws upon qualitative data derived from a study funded by the Education and Training Foundation (ETF) in England over a two-year period from 2021 to 2023. The research population consists of a group of eight practitioner–researchers working in three colleges of Further Education (FE) and one Industry Training Centre (ITC) in England. All of the teachers of vocational education reported here volunteered to participate in the study. Research methods include semi-structured interviews, analysis of critical incidents and case studies produced by practitioner–researchers from across the FE and Skills sector in England. Full article

With the growing global deployment of Fiber-to-the-Home (FTTH) networks driven by the demand for ensuring high-capacity broadband services, mobile network operators (MNOs) face challenges of excessive energy consumption (EC) of wired optical access networks (OANs). This paper presents a comprehensive review of methods aimed at improving the energy efficiency (EE) of wired access passive optical networks (PONs) and active optical networks (AONs). The most important energy management and power-saving methods for Optical Line Terminals (OLTs) and Optical Network Units (ONUs), as key OAN components, are overviewed in the paper. Special attention in the paper is further given to analyzing the impact of a constant increase in the number of subscribers and average data rate per subscriber on global instantaneous power and annual energy consumption trends of FTTH Gigabit PONs (GPONs) and FTTH point-to-point (P-t-P) networks. The analysis combines the real ONU/OLT device-level power profiles and the number of installed OLT and ONU devices with data traffic and subscriber growth projections for the period 2025–2035. A comparative EE analysis is performed for different MNO FTTH OAN architectures and technologies, point-of-presence (PoP) subscriber capacities, and GPON-to-P-t-P subscriber distribution ratios. The findings indicate that different FTTH PON and AON architectures, FTTH technologies, and PON-to-AON subscriber distributions can yield significantly different EE gains in the future. This review paper can serve as a decision-making guide for MNOs in balancing performance and sustainability goals, and as a reference for researchers, engineers, and policymakers engaged in designing next-generation wired optical access networks with minimized environmental impact. Full article

Organic afterglow nanoparticles (OANs) represent a unique class of optical materials capable of sustaining luminescence after excitation cessation. Owing to their exceptional design flexibility, tunable optical properties, and favorable biosafety profiles, OAN-based afterglow imaging has emerged as an advanced modality in tumor diagnosis and therapy. These nanostructures demonstrate significant potential in guiding precision surgical interventions and real-time monitoring of tumor treatment, including photodynamic therapy, photothermal therapy, and immunotherapy. This review systematically analyzes and discusses the luminescence mechanisms of OANs under various excitation sources, with particular emphasis on recent developments in tumor detection and treatment. Additionally, we also discuss the current challenges and future perspectives of using these nanoparticles in this field. Full article

To achieve commercial scalability, fiber-based quantum key distribution (QKD) systems must be integrated into existing optical communication infrastructures, rather than deployed exclusively on dedicated dark fibers. Integrating QKD into optical access networks (OANs) would be particularly advantageous, as these networks provide direct connectivity to end users for whom security is critical. Such integration can address the inherent security vulnerabilities in current OANs, which are primarily based on time-division multiplexing passive optical networks (TDM-PONs). However, integrating QKD into PONs poses significant challenges due to Raman noise and other detrimental effects induced by PON signals, which intensify as the launched power of PONs increases to support higher transmission speeds. In this study, we review recent advancements in both QKD and access network technologies, evaluate the technical feasibility of QKD-OAN integration, and propose cost-effective strategies to facilitate the widespread deployment of QKD in future access networks. Full article

The relentless consumption of fossil fuels and soaring CO₂ emissions have plunged the world into an energy and environmental crisis. As society grapples with these challenges, the demand for clean, renewable, and sustainable energy solutions has never been more urgent. However, even though many efforts have been made in this field, there is still room for improvement concerning efficiency, material stability, and catalytic enhancement regarding kinetics and selectivity of photoelectrochemical (PEC) processes. Herein, we provide the experimental proof for the enhancement of the photocurrent efficiency by the critical focus on semiconductor–electrolyte interface (SEI) properties. By tailoring electrolyte composition, researchers can unlock significant improvements in catalytic efficiency and stability, paving the way for advanced PEC technologies. In this study, we investigate the influence of electrolyte composition on SEI properties and its impact on PEC performance. By employing electrolytes enriched with carbonates, borates, sulphates, and alkali cations, we demonstrate their profound role in optimising photoelectrochemical CO₂ reduction reaction (CO₂RR) efficiency. Central to this work is Cu₂O—an affordable, highly promising photocatalyst. While its potential is undeniable, Cu₂O’s inherent instability and diverse reduction products, ranging from CH₃OH to CO, HCOOH, CH₃COOH, and CH₃CH₂OH, have hindered its widespread adoption in PEC CO₂ reduction (CO₂RR). Our approach leverages a straightforward yet powerful electrodeposition method, enabling a deeper exploration of SEI dynamics during photocatalysis. Key parameters, such as carbonate concentration, local pH, alkali cation presence, anionic geometry, CO₂ solubility, and electrolyte conductivity, are systematically investigated. The findings reveal the formation of a unique “rigid layer” at the photocatalyst surface, driven by specific cation–anion interactions. This rigid layer plays a pivotal role in boosting PEC performance, offering a new perspective on optimising, among other PEC processes, CO₂RR catalytic efficiency. This profound study bridges a critical knowledge gap, shedding light on the dual influence of cations and anions on SEI properties and PEC CO₂RR. By unravelling these intricate interactions, we provide a roadmap for designing next-generation PEC systems. These insights pave the way for sustainable energy advancements, inspiring innovative strategies to tackle one of the most pressing challenges of our time. Full article

Proto- and young planetary nebulae comprise dense circumstellar envelopes made of molecular gas and dust, some of which hide compact ionized cores that host stellar systems with hot objects, and show high-velocity bipolar outflows launched from inside their cores by means of still unknown mechanisms. We present high-angular-resolution Atacama Large Millimeter/submillimeter Array (ALMA) observations (HPBW ≃ 30–50 mas) of CRL 618 at 1.35 mm covering the H30$\alpha$ recombination line as well as ≃150 molecular lines. The ionized core is resolved, showing a size of ≃0${.}^{″}8\times 0{.}^{″}5$ and is elongated along the east–west direction. This region exhibits a remarkable incomplete ring-like structure with two bright spots to the north and south that are separated by ≃$0_{.}^{″}2$ and shows deprojected velocity gradients ranging from 0.2 to 0.6 km ${\mathrm{s}}^{-1}$${\mathrm{au}}^{-1}$. The 1 mm wavelength continuum emission is mostly produced by free–free emission with a small contribution from dust with an average spectral index of 0.28 ($S_{\nu }\propto {\nu }^{\alpha }$). The ionized core can roughly be modeled as a tilted hollow cylinder with a denser, incomplete equatorial band lacking its back side. Molecular emission traces the neutral component of the same structures enclosing the ionized matter. Full article

Infrared dark clouds (IRDCs) are fruitful objects to study the fragmentation of interstellar filaments and initial conditions and early stages of high-mass ($M>8$ M_⊙) star formation. We used the Yebes 40 m and Institut de Radioastronomie Millimétrique (IRAM) 30 m radio telescopes to carry out the first single-pointing spectral line observations towards the IRDC G1.75-0.08, which is a filamentary Central Molecular Zone (CMZ) cloud. Our aim is to reach an improved understanding of the gas kinematics and dynamical state of the cloud and its two clumps that we call clumps A and B. We also aim to determine the fractional abundances of the molecules detected at 3 mm towards G1.75-0.08. We detected HNCO$(J_{K_a,K_c}=4_{0,4}-3_{0,3})$, HCN$(J=1-0)$, and HCO⁺$(J=1-0)$ towards both clumps. The N₂H⁺$(J=1-0)$ line was detected only in clump B, while N₂D⁺$(J=1-0)$ was not detected at all. The HCN and HNCO spectra exhibit two velocity components. The abundances of the detected species are comparable to those in other IRDCs. An upper limit to the [N₂D⁺]/[N₂H⁺] deuterium fraction of <0.05 derived towards clump B is consistent with values observed in many high-mass clumps. The line mass analysis suggests that the G1.75-0.08 filament is subcritical by a factor of $11\pm 6$, and the clumps were found to be gravitationally unbound (${\alpha }_{\mathrm{vir}}>2$). Our finding that G1.75-0.08 is strongly subcritical is atypical compared to the general population of Galactic filamentary clouds. The cloud’s location in the CMZ might affect the cloud kinematics similar to what has been found for the Brick IRDC, and the cloud’s dynamical state might also be the result of the turbulent motions or shear and tidal forces in the CMZ. Because the target clumps are dark at 70 $\mathsf{\mu }$m and massive (several ${10}^3$ M_⊙), they can be considered candidates for being high-mass starless clumps but not prestellar because they are not gravitationally bound. Full article

Rising organic charge in northern freshwaters is attributed to increasing levels of dissolved natural organic matter (DNOM) and changes in water chemistry. Organic charge concentration may be determined through charge balance calculations (Org.⁻) or modelled (OAN⁻) using the Oliver and Hruška conceptual models, which are based on the density of weak acid functional sites (SD) present in DNOM. The charge density (CD) is governed by SD as well as protonation and complexation reactions on the functional groups. These models use SD as a key parameter to empirically fit the model to Org.⁻. Utilizing extensive water chemistry datasets, this study shows that spatial and temporal differences in SD and CD are influenced by variations in the humic-to-fulvic ratio of DNOM, organic aluminum (Al) complexation, and the mole fraction of CD to SD, which is governed by acidity. The median SD values obtained for 44 long-term monitored acid-sensitive lakes were 11.1 and 13.9 µEq/mg C for the Oliver and Hruška models, respectively. Over 34 years of monitoring, the CD increased by 70%, likely due to rising pH and declining Al complexation with DNOM. Present-day median SD values for the Oliver and Hruška models in 16 low-order streams are 13.8 and 15.8 µEq/mg C, respectively, and 10.8 and 12.5 µEq/mg C, respectively, in 10 high-order rivers. Full article

This study analyzes the residual demand curves of 42 countries under five scenarios with varying variable renewable energy (VRE) levels to observe how replacing coal with VRE can alter the demand curve. Using 2018 demand data, the residual demand was calculated and analyzed by subtracting the VRE supply curve from the demand curve. The operational requirements for low-carbon load-following sources amid high VRE penetration are examined. Key findings indicate that substantial peak residual demand persists even with 70% energy from VREs, emphasizing the need for significant load-following resources. Transitioning to a 70% VRE scenario could reduce CO₂ emissions by approximately 16.799 billion tons, advancing towards carbon neutrality. However, this benefit depends on maintaining grid stability, highlighting the importance of adequate load-following plants to manage VRE intermittency. Countries like Malaysia, South Korea, Tunisia, the UK, Japan, Indonesia, Thailand, and Libya face higher load-following demands due to specific renewable energy contexts. This study reveals varying renewable energy environments across countries, suggesting that a universal strategy for carbon neutrality and replacing coal may not be feasible. Each nation must develop its own approach to emission reduction, considering its unique conditions. This research emphasizes the urgent need for developing cost-effective, flexible, low-carbon load-following sources to enhance decarbonization potential globally. Full article

Polyphenols have a variety of phenolic hydroxyl and carbonyl functionalities that enable them to scavenge many oxidants, thereby preserving the human redox balance and preventing a number of oxidative stress-related chronic degenerative diseases. In our ongoing investigation of polyphenol-rich plants in search of novel molecules, we resumed the investigation of Lawsonia inermis L. (Lythraceae) or henna, a popular ancient plant with aesthetic and therapeutic benefits. The leaves’ 70% aq acetone extract was fractionated on a Diaion HP-20 column with different ratios of H₂O/an organic solvent. Multistep gel chromatographic fractionation and HPLC purification of the Diaion 75% aq MeOH and MeOH fractions led to a new compound (1) along with tannin-related metabolites, benzoic acid (2), benzyl 6′-O-galloyl-β-D-glucopyranoside (3), and ellagic acid (4), which are first isolated from henna. Repeating the procedures on the Diaion 50% aq MeOH eluate led to the first-time isolation of two O-glucosidic ellagitannins, heterophylliin A (5), and gemin D (6), in addition to four known C-glycosidic ellagitannins, lythracin D (7), pedunculagin (8), flosin B (9), and lagerstroemin (10). The compound structures were determined through intensive spectroscopic investigations, including HRESIMS, 1D (¹H and ¹³C) and 2D (¹H–¹H COSY, HSQC, HMBC, and NOESY) NMR, UV, [α]_D, and CD experiments. The new structure of 1 was determined to be a megastigmane glucoside gallate; its biosynthesis from gallic acid and a β-ionone, a degradative product of the common metabolite β-carotin, was highlighted. Cytotoxicity investigations of the abundant ellagitannins revealed that lythracin D2 (7) and pedunculagin (8) are obviously more cytotoxic (tumor specificity = 2.3 and 2.8, respectively) toward oral squamous cell carcinoma cell lines (HSC-2, HSC-4, and Ca9-22) than normal human oral cells (HGF, HPC, and HPLF). In summary, Lawsonia inermis is a rich source of anti-oral cancer ellagitannins. Also, the several discovered polyphenolics highlighted here emphasize the numerous biological benefits of henna and encourage further clinical studies to profit from their antioxidant properties against oxidative stress-related disorders. Full article

In this study, nitrogen-doped carbon nanotube/Ag nanocomposites (denoted as N-C/Ag) have been synthesized in a urea solution using a hydrothermal method. The carbon nanotubes, AgNO₃ solution, urea and poly-dopamine (PDA) served as carbon, silver, nitrogen and carbon sources, respectively. The results show that the diameter of the carbon tubes was about 30 nm, and the Ag nanoparticles, with a diameter of ca. 10 nm, dispersed on the carbon tube surface. The Ag particle size decreased with a lower degree of crystallinity at a high temperature in the presence of urea. The friction and wear behavior of the oil acid (OA) modified N-C/Ag (OAN-C/Ag) as an additive in liquid paraffin (LP) were studied using a four-ball friction and wear tester. The results have shown that the coefficients of friction (COFs) and wear scar diameters (WSDs) of steel balls lubricated with LP-OAN-C/Ag decreased by 27.3% and 25.3%, respectively, relative to pure LP. Tribofilms containing Ag, carbon and nitride were formed on the worn steel ball surfaces. Details, the carbon, Fe₂O₃, azides and nitride, Ag and alloy and other compounds on the wear scars may improve tribological properties. The synergistic effect of carbon, Ag and urea plays a critical role during sliding. Full article

Automatic modulation classification (AMC) is an important method for monitoring and identifying any underwater communication interference. Since the underwater acoustic communication scenario is full of multi-path fading and ocean ambient noise (OAN), coupled with the application of modern communication technology, which is usually susceptible to environmental influences, automatic modulation classification (AMC) becomes particularly difficult when it comes to an underwater scenario. Motivated by the deep complex networks (DCN), which have an innate ability to process complex data, we explore DCN for AMC of underwater acoustic communication signals. To integrate the signal processing method with deep learning and overcome the influences of underwater acoustic channels, we propose two complex physical signal processing layers based on DCN. The proposed layers include a deep complex matched filter (DCMF) and deep complex channel equalizer (DCCE), which are designed to remove noise and reduce the influence of multi-path fading for the received signals, respectively. Hierarchical DCN is constructed using the proposed method to achieve better performance of AMC. The influence of the real-world underwater acoustic communication scenario is taken into account; two underwater acoustic multi-path fading channels are conducted using the real-world ocean observation dataset, white Gaussian noise, and real-world OAN are used as the additive noise, respectively. Contrastive experiments show that the AMC based on DCN can achieve better performance than the traditional deep neural network based on real value (the average accuracy of the DCN is 5.3% higher than real-valued DNN). The proposed method based on DCN can effectively reduce the influence of underwater acoustic channels and improve the AMC performance in different underwater acoustic channels. The performance of the proposed method was verified on the real-world dataset. In the underwater acoustic channels, the proposed method outperforms a series of advanced AMC method. Full article

We present an overview of the results obtained from the study of the resolved distribution of molecular gas around eight young ($\lesssim {10}^6\mathrm{yr}$), peaked-spectrum radio galaxies. Tracing the distribution and kinematics of the gas around these radio sources allows us to trace the interplay between the jets and the surrounding medium. For three of these sources, we present new CO(1-0) observations, obtained with the Northern Extended Millimeter Array (NOEMA) with arcsecond resolution. In two of these targets, we also detected CN lines, both in emission and absorption. Combining the new observations with already published data, we discuss the main results obtained. Although we found that a large fraction of the cold molecular gas was distributed in disc-like rotating structures, in the vast majority of the sources, high turbulence and deviations from purely quiescent gas (including outflows) were observed in the region co-spatial with the radio continuum emission. This suggests the presence of an interaction between radio plasma and cold molecular gas. In particular, we found that newly born and young radio jets, even those with low power i.e., P_jet < 10⁴⁵ erg s⁻¹), are able to drive massive outflows of cold, molecular gas. The outflows are, however, limited to the sub-kpc regions and likely short lived. On larger scales (a few kpc), we observed cases where the molecular gas appears to avoid the radio lobes and, instead, wraps around them. The results suggest the presence of an evolutionary sequence, which is consistent with previous simulations, where the type of impact of the radio plasma changes as the jet expands, going from a direct jet-cloud interaction able to drive gas outflows on sub-kpc scales to a more gentle pushing aside of the gas, increasing its turbulence and likely limiting its cooling on kpc scales. This effect can be mediated by the cocoon of shocked gas inflated by the jet–cloud interactions. Building larger samples of young and evolved radio sources for observation at a similar depth and spatial resolution to test this scenario is now needed and may be possible thanks to more data becoming available in the growing public archives. Full article