Browse Articles
Discover research articles across all indexed journals
Demand structure prediction and adaptation path of rural teachers in western China under population change
The construction of a rural teaching workforce is a key factor in promoting educational equity and the development of high-quality education. We employ the Leslie model and the age-specific grade progression rate method to estimate a population forecasting model. Using data from the seventh national census and regional statistical yearbooks and accounting for educational centralization and population trends, we forecast rural preschool, primary, and junior high teacher demand in 12 western Chinese provinces (2024–2040) on the basis of school-age population changes. The results show that (1) population changes have led to a decline in the allocation of rural education resources in western China; (2) the decrease in the school-age population has led to a continuous contraction of the teacher team structure, with a more pronounced decline in the preschool education stage; for example, rural student numbers in Gansu are projected to decline by 35% between 2024 and 2040, contributing to a 28% drop in primary teacher demand under constant policy conditions; and (3) the decline in teacher demand at all educational stages has exacerbated the imbalance in the allocation of educational resources. To address shrinking school-age populations and rural teacher imbalances, we recommend adjusting staffing standards on the basis of demographic forecasts, strengthening cross-stage professional development with clear pathways and incentives, and modernizing training through blended mentoring and data-driven coaching to ensure sustainable education quality.
Eco-friendly spectrofluorimetric and HPLC-fluorescence methods for simultaneous determination of melatonin and zolpidem in pharmaceuticals
Abstract Two eco-friendly, facile, rapid, and highly sensitive analytical methodologies were developed for the concurrent estimation of melatonin and zolpidem tartrate in raw materials and dosage forms. The first approach is a green first derivative synchronous spectrofluorimetric method (Method I), utilizing a wavelength interval (Δλ) of 60 nm and capturing derivative signals at 265.0 nm and 339.0 nm for melatonin and zolpidem, respectively. Method I exhibited excellent linearity over the ranges of 8.0–70.0 ng/mL for melatonin and 10.0–80.0 ng/mL for zolpidem, with detection limits of 1.62 ng/mL and 1.19 ng/mL. The second method (Method II) involves high-performance liquid chromatography coupled with fluorescence detection (HPLC-FD), employing a C18 column and a mobile phase of methanol:0.05% triethylamine (70:30, v/v, pH 5.5) at a flow rate of 1.0 mL/min. Fluorescence detection was performed at 383 nm following excitation at 243 nm. This method achieved linearity within 150.0–1500.0 ng/mL for melatonin and 50.0–700.0 ng/mL for zolpidem, with detection limits of 18.87 ng/mL and 8.86 ng/mL, respectively. Both methods were rigorously validated in accordance with ICH Q2(R1) guidelines, demonstrating high accuracy, precision, and robustness in analyzing commercial dosage forms. Greenness and sustainability were quantitatively assessed using the AGREE and eco-scale metrices, while method applicability and performance were evaluated using the Blue Applicability Grade Index (BAGI), affirming both techniques as efficient and environmentally sustainable tools for routine quality control.
Multidimensional analysis of register variation in English translations of Shijing
This study employs Multidimensional Analysis (MDA) to compare the register of Arthur Waley’s and Ezra Pound’s translations of Shijing, and further explores the factors contributing to their differences. The key findings are as follows: (1) Waley’s translation corresponds to the “involved persuasion” register, characterized by high interactivity and extensive informational elaboration. In contrast, Pound’s translation aligns with the “general narrative exposition” register, emphasizing informativeness and narrativity; (2) The interactivity in Waley’s translation is primarily driven using analytic negation, first-person pronouns, and modal verbs, while the elaboration is attributed to the frequent use of demonstrative pronouns. In contrast, Pound’s translation exhibits strong informativeness due to the frequent use of nouns and prepositional phrases, while its narrativity is shaped by synthetic negation and public verbs; (3) Waley’s approach prioritizes an accurate reflection of ancient Chinese society and the preservation of cultural heterogeneity. In contrast, Pound’s translation focuses on didacticism, emotional energy, and precision. The differences in the translators’ ideologies and poetic philosophies are identified as the primary factors accounting for the register variations in their translations.
Novel assembly of a head–trunk interface in the sister group of jawed vertebrates
Highly precise optical detection of mass destruction nerve agents based on photonic crystal fibers
Abstract Nerve agents such as Sarin, Soman, and Tabun are among the most lethal chemical warfare agents, classified as mass destruction agents due to their extreme toxicity and rapid disruption of the nervous system. These highly volatile and easily dispersible compounds can be deployed in warfare or acts of terrorism, causing fatal respiratory failure, seizures, and irreversible nerve damage even at minimal exposure. The urgency of detecting these agents with high precision is critical for global security and counterterrorism efforts. To address this challenge, a highly sensitive photonic crystal fiber (PCF) sensor with an elliptical cladding and circular core (E-PCF) is designed for the rapid and accurate detection of nerve agents in the terahertz (THz) spectrum. The sensor employs circular air holes in the vestibule region to enhance light-matter interaction, optimizing detection through key performance metrics such as relative sensitivity, effective material loss, and confinement loss. Using two materials, such as silica glass and Zeonex as background materials, the proposed sensor demonstrates exceptional sensitivity and minimal loss. Numerical analysis within the 1.6–3.6 THz range reveals outstanding performance for Sarin (99.6% relative sensitivity, 3 × 10⁻13 dB/m confinement loss), Soman (98.8% relative sensitivity, 1.1 × 10⁻¹² dB/m loss), and Tabun (98% relative sensitivity, 7.6 × 10⁻11 dB/m loss). With its exceptional optical properties, silica glass ensures highly reliable detection, making the proposed sensor a powerful tool for counterterrorism efforts, environmental monitoring, industrial hazard detection, and military defense. This innovative PCF-based sensing technology marks a major breakthrough in chemical warfare agent detection, providing a fast, precise, and efficient solution for identifying highly toxic substances that pose severe threats to public safety and national security.
Elevating image segmentation with multilevel two-dimensional quantum representation
In the rapidly advancing field of image analysis and processing, accurately segmenting images into meaningful regions remains a critical challenge. Drawing from recent advancements in quantum computing and information theory, our research introduces an innovative approach to image segmentation. This work presents a novel multilevel segmentation method that utilizes a two-dimensional quantum image representation, offering a more sophisticated and efficient technique for image thresholding. In this framework, the image’s 2D histogram is treated as a quantum system, with quantum Rényi entropy used to quantify the information contained within the image. To enhance segmentation quality, we first improve the contrast of the images by applying a new contrast enhancement algorithm before performing the segmentation. The resulting entropy-based fitness function is then optimized using Differential Evolution (DE) and Particle Swarm Optimization (PSO) algorithms to determine the optimal thresholding values. A comprehensive comparative analysis is conducted between the proposed quantum method and traditional classical approaches, evaluated on a set of benchmark images using nine metrics, including the Wilcoxon test for statistical significance. Experimental results demonstrate the effectiveness of the PSO optimizer, the superiority of the two-dimensional quantum image representation.
Correction: Harnessing quantum entanglement and heat current of a non-equilibrium spin system at high temperatures
Randomized controlled trial on improving pesticide label interpretation among farmers in Akkar Governorate, Lebanon: The impact of a whatsapp-delivered educational video
Background Pesticide misuse poses significant health and environmental risks, particularly in low- and middle-income countries. In Lebanon, improper pesticide handling and a lack of understanding of pesticide labels among farmers are major concerns. This study evaluated the effectiveness of a WhatsApp-delivered educational video compared to traditional in-person educational sessions in improving farmers’ pesticide safety knowledge, label interpretation, and handling practices. Design This study employed a parallel-group, three-arm randomized controlled trial (RCT) with three groups: a traditional educational session group, a WhatsApp-delivered educational video group, and a control group receiving no intervention. Setting/participants The study was conducted in the coastal villages of Akkar Governorate, northern Lebanon, from June to August 2024. One hundred thirty- three agricultural farmers were recruited through systematic sampling from a list of registered farmers, based on their pesticide use and access to WhatsApp. Interventions Participants were randomly assigned to one of three groups: the control group received no intervention; the traditional education group participated in an in-person training session focused on pesticide safety, health risks, and label interpretation; the digital video group received a 4-minute educational video via WhatsApp, covering the same topics as the traditional session. Main outcome measures Primary outcomes included the ability to interpret Food and Agriculture Organization of the United Nations (FAO) pictograms, knowledge of pesticide health risks, and understanding the environmental impacts of pesticide misuse. Secondary outcomes assessed the use of personal protective equipment (PPE) and changes in pesticide handling practices. Results The video-based group showed the most significant improvement in pesticide handling, knowledge, and awareness of health and environmental risks, outperforming the traditional education group. The control group showed minimal changes. The video-based intervention was especially effective in enhancing the interpretation of pesticide labels, including complex pictograms and color codes. Conclusion The results demonstrate that WhatsApp-delivered video interventions are superior in improving pesticide safety knowledge and practices compared to traditional methods. This cost-effective, scalable approach provides a viable solution for disseminating agricultural safety education, particularly in resource-limited areas. The study highlights the potential of digital learning tools to reach a wide audience with fewer resources, contributing to safer pesticide use and reducing health and environmental risks. Trial registration International Standard Randomised Controlled Trial Number ISRCTN12809193
Correction: JNK2-MMP-9 axis facilitates the progression of intracranial aneurysms
Effects of different irrigation methods on the spatial and temporal distribution of soil temperature
Drip irrigation delivers water uniformly and precisely to the root zone, thereby influencing the soil hydrothermal regime of the soil. While this characteristic makes drip irrigation a promising water-saving technique, there are limited long-term comparative studies on drip irrigation and flood irrigation, which cannot comprehensively and systematically elucidate the impact of water-saving irrigation on soil temperature in Northwest China. We conducted a five-year field experiment from 2017 to 2021, focusing on the comprehensive impact of two irrigation methods (drip irrigation and flood irrigation) on soil temperature at different depths and at different positions (dripper source, root zone, inter-row buffer) during the maize growth periods. The results revealed that soil temperature and meteorological temperature had an extremely significant correlation (p < 0.001), and that the soil surface layer was more susceptible to air temperature influences and was positively correlated with atmospheric temperature. Compared to flood irrigation, drip irrigation increased soil temperature by 1.4%, while soil temperature exhibited a significant negative correlation with soil depth. Specifically, at 0 cm depth, the soil temperature varied most significantly, ranging from 19.79°C to 28.38°C, while at 90 cm, it was 19.98°C – 21°C. Compared to other positions, root zone soil temperature increased by 0.5% to 2.25%. Therefore, drip irrigation not only enhances soil temperature but also optimizes hydrothermal conditions for crop roots. The contribution of this study lies in its integration of multi – year, multi – depth, and multi – positional monitoring under field conditions, which fills a major gap in understanding how irrigation systems influence soil thermal regimes in dry locations. This study provides an actionable theoretical framework for optimizing water use efficiency and crop productivity in water-scarce agroecosystems, while also laying a solid scientific foundation for the development of sustainable management models for agricultural water resources in arid regions.
Trophic dynamics and metabolic pathways in host parasite interactions revealed by nitrogen isotope analysis of amino acids in multiple tissues
Abstract Trophic interactions are crucial for understanding food web complexity and energy flow in ecosystems. Including parasites in these analyses can alter dynamics and challenge ecological assumptions. Compound-specific isotope analysis offers greater precision than bulk stable isotope analysis by analyzing individual amino acids, providing deeper insights into nutrient exchange and metabolism in host-parasite systems. In this study, we conducted a 120-day controlled feeding experiment to investigate parasite metabolic pathways, host-parasite trophic dynamics, and trophic fractionation between infected and uninfected sticklebacks. Nitrogen isotope composition (δ 15 N) was measured in host Gasterosteus aculeatus liver and muscle tissues, and its ‘cestode’ parasite ( Schistocephalus solidus ). Parasite serine δ 15 N values were higher by 4.4 ± 2.4‰ compared to host liver, indicating a strong metabolic link. Lower proline concentrations and increased alanine δ 15 N values (5‰) indicate support of parasite growth through conversion to hydroxyproline and increased gluconeogenesis. The trophic position difference between parasite and host tissues was < 0.5, suggesting direct assimilation of host-derived products. Infected host tissues exhibited ~ 5‰ increase in glycine δ 15 N over time compared to control tissues, likely reflecting the host’s increased metabolic demand for immune support during infection. This study highlights the complex metabolic interactions in host-parasite systems.
Disintegration behavior and improvement mechanism of guar gum modified red clay in dry and wet cycle
As an improved agent, GG (Guar Gum) has been widely used in engineering reinforcement in recent years. To assess the potential of engineering applications in red clay areas, the study examined the disintegration behavior of red clay and the improvement effects of both pure and modified red clay containing 0.05%, 0.1%, 0.15%, 0.2%, and 0.25% GG under dry and wet cycle conditions. By quantifying the macroscopic mechanisms of GG’s impact on red clay and elucidating the microscopic mechanisms of GG’s improvement effects, the potential for engineering applications in red clay areas was confirmed. The experimental research results show that: (1) With an increase in GG dosage, the disintegration of red clay first decreases and then stabilizes, with the optimal improvement effect achieved at a GG dosage of 0.225%. (2) When the number of dry and wet cycles increases, the disintegration rate of GG-improved red clay increases less than that of unmodified soil. (3) Both macroscopic and microscopic improvement mechanisms show that GG can effectively improve the strength and stability of red clay by enhancing soil particles, improving particle grading, filling gaps, and forming GG kaolinite cementing bonds. In summary, GG has demonstrated great potential as an improved agent in engineering applications in areas with red clay. The research results enhance the understanding of the anti-disintegration behavior of red clay and provide a theoretical basis for improving soil engineering performance in areas with red clay.
Breastfeeding on ART and a closer look at drug transfer to HIV-exposed uninfected infants
Abstract Adherence to antiretroviral therapy (ART) and maintaining an undetectable maternal HIV viral load effectively prevent intrauterine and perinatal HIV transmission 1, 2. However, concerns remain regarding the safety of breastfeeding in infants exposed to maternal ART. This retrospective study analyzed eight breastfed HIV-exposed uninfected (HEU) infants who were followed from January 2015 to July 2022. Maternal ART regimens included abacavir/lamivudine (n = 2), tenofovir alafenamide/emtricitabine (n = 1) or tenofovirdisoproxil/emtricitabine (n = 5) in combinations with rilpivirine (n = 3) (RPV), dolutegravir (n = 2) (DTG), raltegravir (n = 1), darunavir/ritonavir (n = 1), or nevirapine (n = 1). Infants and mothers underwent sequential HIV-PCR testing, complete blood count, and ART drug monitoring in breast milk, infant serum, and maternal serum when available. The relative infant dose (RID) was calculated to assess drug exposure. Hematological parameters were compared with those of 62 HEU formula-fed infants from the same institution. No HIV transmission occurred. ART serum levels in breastfed infants varied significantly, with RPV and DTG levels above the adult target range in two cases. Notably, one infant had RPV levels exceeding the target RID by 633%, leading to cessation of breastfeeding. At four months, mean absolute neutrophil counts were lower in breastfed infants (1,130/µl) compared to formula-fed infants (2,000/µl), with the lowest individual absolute neutrophil counts in the formula-fed group. Despite ART levels above the adult target range in 3 infants, there was no consistent pattern between neutropenia and elevated ART levels. Our findings highlight the substantial variability in infant ART exposure during breastfeeding. Given this variability and the potential for drug accumulation in individual cases, maternal therapeutic drug monitoring should be considered to identify elevated levels early on. In such situations, infant monitoring tailored to the individual may also be warranted.
Prevalence and associated factors of occupational injuries among garment and textile workers: Evidence from the Bangladesh Labour Force Survey 2016–17
Annually, numerous workers face job loss, injuries, and fatalities due to various occupational injuries (OIs). However, less is known regarding the burden of OIs and their associated factors in the textile and garment industries in Bangladesh. This study aimed to determine the prevalence of OI and the individual and job-related factors associated with OI among textile and garment workers in Bangladesh. We analyzed cross-sectional data of 13,738 workers collected during 2016–2017 from the nationally representative Bangladesh Labor Force Survey. We employed multiple Firth logistic regression models to explore the different levels of associated factors of OI. The overall prevalence of OI was 1.8%, with a higher prevalence in the textile industry (3.8%) compared to the garment industry (1.2%). Within the textile industry, jute manufacturing exhibited the highest prevalence (12.3%), while in the garment sector, the embroidery and wearing industries had the highest prevalence (1.8%). Adjusted models revealed that, in the textile industry, migrant workers had higher odds of OI (Adjusted Odds Ratio, AOR = 1.65; p = 0.017) compared to non-migrant workers. In the garment industry, male workers (AOR = 1.95; p = 0.002) and those working over 48 hours per week (AOR = 1.70; p = 0.063) were at greater risk of OI. A hazardous work environment significantly increased the odds of OI in both industries (textile: AOR = 13.06; p < 0.001; and garment: AOR = 3.13; p < 0.001). Additionally, garment workers without adequate protective equipment or cloth while working had a higher likelihood of OI (AOR = 1.90; p = 0.006). Regionally, workers in the Barisal division had higher odds of OI in the textile industry. Although the overall prevalence of OI was low, the disproportionate burden among certain subgroups, especially in jute manufacturing and the manufacture of spooling and thread, highlights critical areas for intervention. Improving workplace safety through the provision of protective equipment and a safer working environment is essential to mitigating OI in the textile and garment industries of Bangladesh.
Two-billion-year transitional oxygenation of the Earth’s surface
Anti-inflammatory and cytotoxic assessment of flavonoids isolated from Viola odorata flowers with computer-guided docking study
Abstract The therapeutic potential of plant-derived polyphenols has garnered significant attention due to their roles in modulating inflammation and cancer progression. Viola odorata (V. odorata), traditionally used in herbal medicine, is known for its bioactive constituents, yet comprehensive profiling of its floral phytochemicals—particularly phenolic acids, flavonoids, and anthocyanins—remains limited. This study was pharmacologically designed to investigate the detailed phytochemical composition of V. odorata flowers and evaluate their anti-inflammatory and anticancer activities, aiming to identify novel natural agents for therapeutic development. Methanolic extracts of V. odorata flowers were analyzed for total phenolics, flavonoids, and anthocyanins using spectrophotometric methods. HPLC and UPLC/ESI–MS techniques were employed to identify and quantify individual compounds. Structural elucidation of isolated flavonoids was performed using advanced spectroscopic techniques. The anti-inflammatory and cytotoxic effects of the extract and isolated flavonoids were assessed in vitro using hepatocellular carcinoma (HepG2), human colonic epithelial (Caco-2), and colorectal carcinoma (HTC-116) cell lines. Molecular dynamics simulations were conducted to explore the interactions underlying the observed bioactivities. The methanolic extract contained 81.34 ± 0.17 mg GAE/g of total phenolics, 69.45 ± 0.24 mg CE/g of flavonoids, and 92.43 mg cyanidin-3-glucoside/100 g of anthocyanins. HPLC analysis revealed twelve phenolic acids and ten flavonoids, with gentisic acid (391.37 μg/g), apigenin-7-glucoside (417.22 μg/g), catechin (372.56 μg/g), and rutin (262.73 μg/g) being predominant. UPLC/ESI–MS identified 8 phenolic acids and derivatives, 3 flavonols, 4 flavones, 14 flavonoid glycosides, and 5 anthocyanins derived from cyanidin, delphinidin, and petunidin. Three flavonoids—5,7-dihydroxy-3,6-dimethoxyflavone, luteolin 7-O-glucoside, and kaempferol 3-O-rutinoside—were isolated and structurally characterized. The extract and isolated compounds exhibited dose-dependent cytotoxicity and anti-inflammatory effects across all tested cell lines. Molecular dynamics studies supported the observed inhibitory mechanisms. This study highlights the rich polyphenolic profile of V. odorata flowers and their promising anti-inflammatory and anticancer properties. The correlation between phytochemical composition and pharmacological activity underscores the therapeutic potential of V. odorata as a source of bioactive compounds for drug development.
What motivates people with type 2 diabetes to maintain lifestyle changes and what challenges do they experience? A qualitative evidence synthesis
Background People with type 2 diabetes often find recommended lifestyle changes difficult to achieve and can find it particularly difficult to maintain these changes. It is therefore useful to explore their views and experiences about what influences them when attempting to achieve these goals. Objectives To identify, appraise and synthesise qualitative studies that explore what motivates people with type 2 diabetes to maintain lifestyle changes over time and the challenges they experience. Methods We included qualitative studies and mixed methods studies with a qualitative component, in any language, of adults who had type 2 diabetes and who had maintained lifestyle changes for a minimum of twelve months. We searched MEDLINE, CINAHL, PsycINFO and EMBASE from inception to 4th November 2024. We extracted data using a pre-designed form and assessed methodological limitations using predefined criteria. We used a thematic synthesis approach to analyse the data. We assessed our confidence in the review findings using the GRADE‐CERQual approach. Finally, we used our findings to develop a model using the locus of control theory and to develop implications for practice. Results We included twelve studies from Europe, USA, Canada, South-Africa, Australia and New Zealand. Participants described several factors that motivated them to maintain lifestyle changes, including getting support from others, seeing results from their lifestyle changes, walking as an activity, being physically active with others, fearing the consequences of type 2 diabetes, and taking control. Factors that they viewed as challenging included mental, physical, practical, and social challenges around exercise, and lack of follow-up from healthcare professionals. Conclusions Our review identified several factors that may influence maintenance of lifestyle changes in type 2 diabetes. Based on these findings, we have developed a series of questions to help people with type 2 diabetes and their healthcare providers think about how best to maintain lifestyle choices over time.
High gain quad-port circularly polarized aperture-coupled MIMO antenna
Abstract This paper presents the design and implementation of a quad-port aperture-coupled circularly polarized (CP) multiple-input multiple-output (MIMO) antenna, specifically fitted for X-band applications. The proposed antenna features an innovative design that uses a 90° power divider to excite two orthogonal modes. This is achieved through an aperture Line that is coupled to a patch via two unique, orthogonal dog-bone slots. A key element of the design is a parasitic patch, which incorporates a 9× 9 array of square pixel cells. This array is strategically included to simultaneously boost the antenna’s gain and improve its axial ratio (AR) bandwidth. The problem of achieving high-performance CP MIMO in the X-band is addressed by the clever use of orthogonal mode excitation and the parasitic patch with its array. By carefully coupling the orthogonal modes, the antenna achieves circular polarization, which is critical for reducing multipath interference. The parasitic patch’s role is to act as a director, enhancing the overall radiation characteristics without significantly increasing the antenna’s size or complexity. This method allows for a compact design while maintaining high performance. The experimental and simulation results showed strong agreement. The antenna achieved an impressive impedance bandwidth (IBW) of 9.8–13 GHz (28%) and a 3-dB axial ratio bandwidth (ARBW) of 10.7–12.27 GHz (13.67%). Measured port isolations are below − 20 dB, with a gain of 7–8 dBic across the frequency band. The antenna’s MIMO performance was excellent, as evidenced by a diversity gain (DG) of at least 9.99 dB, an envelope correlation coefficient (ECC) of 0.002 or less, and channel capacity loss (CCL) ≤ 0.2 bit/s/Hz, demonstrating its outstanding diversity capabilities. These results confirm the antenna’s suitability for advanced X-band wireless technologies that require high data rates and robust connectivity.
A possible volcanic origin for the Greenland ice core Pt anomaly near the Bølling-Allerød/Younger Dryas boundary
The Younger Dryas Event (YDE) is the most recent and most well-understood millennial-scale cooling event. A deglacial meltwater pulse is the traditionally accepted trigger for the event, but both a bolide impact and volcanism are recently advanced alternative explanations. A high Pt/Ir and Pt/Al geochemical anomaly within the Greenland Ice Sheet Project (GISP2) ice core, broadly coinciding with the YDE initiation, provides a possible geochemical clue to the events leading up to the YDE. Previous research has suggested that the impact of an unknown type of high Pt/low Ir iron meteorite may have produced this Pt spike, but the timing is also very close to a large sulphur spike within the North Greenland Ice Core Project (NGRIP) ice core and the timing of the Laacher See volcano eruption (which occurred at approximately 13 ka), suggesting a possible volcanic origin. Here, we evaluate both suggestions by i) presenting new geochemical data from the Laacher See Tephra (LST) and ii) confirming the Pt spike timing relative to the YDE onset on the GICC05 timescale. Our geochemical results, and specifically iridium and platinum data, strongly suggest that the Laacher See eruption (LSE) was most likely not the source of the Greenland Pt spike. Additionally, we corroborate recent work showing a chronological offset of several decades between the Pt spike and the North Greenland Ice Core Project (NGRIP) sulphur spike, the initiation of the YDE at 12,870 ± 30 yr BP (years before present, where present is defined as 1950 CE), and the nearest published age estimate for the LSE (12,880 ± 40 yr BP – though we note that more recent age determinations potentially push this date back by ~130 years). Based on modern data showing that Pt spikes in ice cores and sediment can arise from volcanic eruptions, we suggest that the GISP2 Pt anomaly may represent fractionated volcanic material from another, unknown volcanic eruption. Volcanic gas condensates from submarine volcanic complexes, and in particular Niuatahi-Motutahi (Tonga rear arc), have a Platinum Group Element (PGE) geochemistry most resembling the Pt spike, and we therefore suggest that the Pt spike represents highly fractionated material from an Icelandic subglacial or submarine fissure eruption. The 14-year-long duration of the Pt spike is also more consistent with a fissure eruption than an instantaneous event.