Search Results (4,688)

The Pacific Alliance has established itself as one of the most dynamic regional economic integration initiatives, standing out for its pragmatic and consensual approach to trade, capital and people liberalisation. However, between 2020 and 2025, the bloc faced both opportunities and challenges arising from the international situation, including global tensions, internal political crises and the need for technological adaptation. Against this backdrop, this study aims to conduct a systematic review of the scientific literature published between 2020 and 2025 on the Pacific Alliance, identifying the predominant theoretical approaches and the main findings on the integration process. This systematic review followed the PRISMA methodology, which contributed fundamentally to this research by providing a structured, transparent and rigorous framework for a deeper and more informed understanding of the integration process. The results show that, despite some progress, structural limitations persist, such as asymmetries between countries, institutional obstacles and superficial integration in economic and social aspects, as well as fragmentation in academic production and little incorporation of geopolitical perspectives. This study contributes to a critical understanding of the current state and future challenges of the Pacific Alliance, offering inputs for the formulation of public policies and future research in the field of Latin American integration. Full article

For arid and semi-arid regions like Xinjiang, analyzing the spatiotemporal patterns of September precipitation and their atmospheric circulation teleconnections is crucial for ecosystem preservation. This research examined how the August Asian–Pacific Oscillation (APO) influenced the September precipitation patterns in northern Xinjiang. The results show that the thermal anomalies resulting from the August APO exhibited persistence into September, triggering atmospheric circulation anomalies that ultimately affected the precipitation patterns in northern Xinjiang, with a notable negative correlation. The positive (negative) August APO phase corresponded to reduced (increased) mid-tropospheric geopotential heights over Asia and the Arabian Sea, significantly enhancing anomalous cyclonic (anticyclonic) circulation patterns in these regions. These circulation patterns induced anomalous northerlies (southerlies) over northern Xinjiang and the region from eastern Iran to the Persian Gulf, thereby reducing (increasing) the moisture transport from the Arabian Sea. Furthermore, the anomalous divergence (convergence) of cold/warm air masses and subsidence (ascent) motions exacerbated (enhanced) these effects, ultimately suppressing (enhancing) the September precipitation in northern Xinjiang. Full article

The spatial and seasonal characteristics of submesoscales in the Northwest Pacific Subtropical Ocean are thoroughly investigated here using a submesoscale-permitting model within a localized multiscale energetics framework, in which three scale windows termed background, mesoscale, and submesoscale are decomposed. It is found that submesoscale energetics are highly geographically inhomogeneous. In the Luzon Strait, baroclinic and barotropic instabilities are the primary mechanisms for generating submesoscale available potential energy (APE) and kinetic energy (KE), and they exhibit no significant seasonal variations. Although buoyancy conversion experiences pronounced seasonal cycles and serves as the main sink of submesoscale APE in winter and spring, its contribution to submesoscale KE is negligible. The major sinks of submesoscale KE are advection, horizontal pressure work, and dissipation. In the Western Boundary Current transition and Subtropical Countercurrent (STCC) interior open ocean zone, submesoscales undergo significant seasonality, with large magnitudes in winter and spring. In spring and winter, baroclinic instability dominates the generation of submesoscale APE via forward cascades, while KE is mainly energized by buoyancy conversion and dissipated by the residual term. Meanwhile, in summer and autumn, submesoscales are considerably weak. Additionally, submesoscale energetics in the Western Boundary Current transition zone are slightly greater than those in the STCC interior open ocean zone, which is attributed to the strengthened straining of the Western Boundary Current and mesoscale eddies. Full article

Digital twins represent a transformative innovation for battery energy storage systems (BESS), offering real-time virtual replicas of physical batteries that enable accurate monitoring, predictive analytics, and advanced control strategies. These capabilities promise to significantly enhance system efficiency, reliability, and lifespan. Yet, despite the clear technical potential, large-scale deployment of digital twin-enabled battery systems faces critical governance barriers. This study identifies three major challenges: fragmented standards and lack of interoperability, weak or misaligned market incentives, and insufficient cybersecurity safeguards for interconnected systems. The central contribution of this research is the development of a comprehensive governance framework that aligns these three pillars—standards, market and regulatory incentives, and cybersecurity—into an integrated model. Findings indicate that harmonized standards reduce integration costs and build trust across vendors and operators, while supportive regulatory and market mechanisms can explicitly reward the benefits of digital twins, including improved reliability, extended battery life, and enhanced participation in energy markets. For example, simulation-based evidence suggests that digital twin-guided thermal and operational strategies can extend usable battery capacity by up to five percent, providing both technical and economic benefits. At the same time, embedding robust cybersecurity practices ensures that the adoption of digital twins does not introduce vulnerabilities that could threaten grid stability. Beyond identifying governance gaps, this study proposes an actionable implementation roadmap categorized into short-, medium-, and long-term strategies rather than fixed calendar dates, ensuring adaptability across different jurisdictions. Short-term actions include establishing terminology standards and piloting incentive programs. Medium-term measures involve mandating interoperability protocols and embedding digital twin requirements in market rules, and long-term strategies focus on achieving global harmonization and universal plug-and-play interoperability. International examples from Europe, North America, and Asia–Pacific illustrate how coordinated governance can accelerate adoption while safeguarding energy infrastructure. By combining technical analysis with policy and governance insights, this study advances both the scholarly and practical understanding of digital twin deployment in BESSs. The findings provide policymakers, regulators, industry leaders, and system operators with a clear framework to close governance gaps, maximize the value of digital twins, and enable more secure, reliable, and sustainable integration of energy storage into future power systems. Full article

The Haiyang-2B (HY-2B) satellite, launched on 25 October 2018, carries both active and passive microwave sensors, including a scanning microwave Radiometer (SMR), to deliver high-precision, all-weather global observations. Sea surface temperature (SST) is among its key products. We evaluated the HY-2B SMR Level-4A (L4A) SST (25 km resolution) over the North Pacific (0–60°N, 120°E–100°W) for the period 1 October 2023 to 31 March 2025 using the extended triple collocation (ETC) and dual-pairing methods. These comparisons were made against the Remote Sensing System (RSS) microwave and infrared (MWIR) fused SST product and the National Oceanic and Atmospheric Administration (NOAA) in situ SST Quality Monitor (iQuam) observations. Relative to iQuam, HY-2B SST has a mean bias of –0.002 °C and a root mean square error (RMSE) of 0.279 °C. Compared to the MWIR product, the mean bias is 0.009 °C with an RMSE of 0.270 °C, indicating high accuracy. ETC yields an equivalent standard deviation (ESD) of 0.163 °C for HY-2B, compared to 0.157 °C for iQuam and 0.196 °C for MWIR. Platform-specific ESDs are lowest for drifters (0.124 °C) and tropical moored buoys (0.088 °C) and highest for ship and coastal moored buoys (both 0.238 °C). Both the HY-2B and MWIR products exhibit increasing ESD and RMSE toward higher latitudes, primarily driven by stronger winds, higher columnar water vapor, and elevated cloud liquid water. Overall, HY-2B SST performs reliably under most conditions, but incurs larger errors under extreme environments. This analysis provides a robust basis for its application and future refinement. Full article

Stream temperatures are expected to increase with warming air temperatures, yet the extent and aquatic health impacts vary significantly across heterogeneous landscapes. This study was conducted in a 3360-ha multi-land-use watershed in the Pacific Northwest region of the USA to assess and compare the driving factors for stream temperature heating, cooling, and cool-water refugia along a 12-km mainstem stream longitudinal profile. Study objectives were to (1) determine yearlong stream temperature variability along the entire stream longitudinal profile, and (2) assess stream-environment relationships influencing stream temperature dynamics across forest, agriculture, and urban landscapes within the watershed. Stream and riparian air temperatures, solar radiation, shade, and related stream-riparian characteristics were measured over six years at 21 stations to determine changes, along the longitudinal profile, of thermal sensitivity, maximum and minimum stream temperatures, and correlation between solar radiation and temperature increases, and potential causal factors associated with these changes. Solar radiation was a primary heating factor for an exposed agricultural land use reach with 57% effective shade, while southern stream aspects and incoming tributary conditions were primary factors for forested reaches with greater than 84% effective shade. Potential primary cooling factors were streambank height, groundwater inflows, and hyporheic exchange in an urban reach with moderate effective shade (79%) and forest riparian width (16 m). Combining watershed-scale analysis with on-site stream-environmental data collection helps assess primary temperature heating factors, such as solar radiation and shade, and potential cooling factors, such as groundwater and cool tributary inflows, as conditions change along the longitudinal profile. Full article

The Pacific saury (Cololabis saira), widely distributed in the North Pacific Ocean, is a significant pelagic fishery species in China and has been designated as a priority management species by the North Pacific Fisheries Commission (NPFC). This study examined the trace element characteristics of Pacific saury otoliths and the migration patterns of this species. Based on samples collected from the high seas of the Northwest Pacific Ocean, we estimated their daily age, measured the trace element contents of the otoliths at various life history stages, and analyzed the Sr/Ca, Ba/Ca, Mg/Ca, and Na/Ca values in the otoliths and their relationship with sea surface temperature (SST) changes. The main findings were as follows: (1) Cluster analysis showed significant differences (p < 0.05) in the Sr/Ca, Ba/Ca, Mg/Ca, and Na/Ca values in the core regions of otoliths among the clusters. (2) An analysis of the elemental characteristics across life history stages showed significant differences (p < 0.05) in the Sr/Ca values prior to the juvenile stage (31~90 d) and following the young stage (91~180 d). Significant variations (p < 0.05) in the Ba/Ca values during the juvenile and immature stages imply vertical migration behavior. Additionally, the Mg/Ca and Na/Ca values in adult stages showed significant differences (p < 0.05) to those in early life history stages. (3) GAM fitting and cross-correlation function tests demonstrated a statistically significant (p < 0.05) nonlinear lagged relationship between the otolith Sr/Ca values and SST. Full article

Pharomachrus mocinno breeds in the cloud forests of the El Triunfo Biosphere Reserve, and migrates annually for six months to elevations of 900–1600 m. On the Gulf slope, temperate forests were identified as habitats for migration, but the forests on the Pacific slope have not been similarly described. In this study we described the emergent properties and phenological behavior of the plant communities of five sites identified as migration habitats, in order to test if the number of fruit-bearing species is related to the migration period. At each site, 10,000 m² was sampled, for which PBH (perimeter at breast height) and the height of shrubs and trees were annotated, including the number of palms and ferns included. We identified 25 orders, 41 families, 71 genera, and 94 species; 86.6% of these species produce fleshy fruits or fruits with modified structures that are eaten by Quetzals. During the migration period, 25–43% of these species have fruits. Eight woody species included 49% of the total individuals, which produce Quetzals’ feeding resources. The sites differed in vertical structure, composition and diversity levels. The rarefaction curve indicated that the upper site (1600 m) required more sampling. We identified three plant communities that were distributed either in montane rain forest or in the temperate forest. Since nearly 84% of the plant species are listed in the IUCN (International Union for Conservation of Nature), these forests have an intrinsic importance. The number of fruit-bearing species did not differ between migration and breeding seasons (X² (1, N = 76) 0.57; p = 0.32. Lauraceae did not stand out for the number of fruit-bearing species in any of the migration sites. Full article

Background/Objectives: Sex determination and differentiation exhibit remarkable molecular diversity across taxa, driven by genetic, epigenetic, and environmental factors. Invertebrates with sequential hermaphroditism, such as the Pacific oyster (Magallana gigas), represent a poorly understood system despite their role as keystone species and contribution to a substantial aquaculture industry. Methods: To identify sex-related molecular markers during gametogenesis, we repeatedly sampled hemolymph from artificially conditioned oysters over two months, and sex phenotypes were assigned at the end of the experiment by biopsy. Results: RNA-sequencing analysis of five males and five females revealed subtle yet consistent sex-specific transcriptional signatures in hemolymph. We show that gametogenesis proceeds asynchronously among oysters, even within the same sex individuals. Complex physiological trade-offs were discovered between sexes during gonad maturation; in early stages of sexual maturation, females prioritized cell division, whereas males suppressed it. Females exhibited higher expression of solute carrier family (SLC) genes, suggesting enhanced nutrient exchange during oogenesis. Temporal dynamics highlighted differential expression of genes regulating cross-membrane ion gradients (e.g., transient receptor potential channels) and signal transduction (e.g., signal transducer and activator of transcription), previously linked to environmental sex determination (ESD) in some reptilian species. Conclusions: Together, these findings underscore that gametogenesis in Pacific oysters is complex and dynamic, and that molecular pathways of ESD may be partially conserved between invertebrate and vertebrate species. Full article

Improving tropical cyclone (TC) track forecasts is critical for enhancing disaster prevention and mitigation efforts. This study evaluates the effectiveness of the spectral nudging (SN) technique in simulating TC tracks with diverse path patterns over the Western North Pacific using the Weather Research and Forecasting (WRF) model. The results show that the SN technique is remarkably effective in improving tropical cyclone track forecasts for all types of regular track patterns, except for irregular tracks. Specifically, spectral nudging reduced simulated mean track position errors by approximately 60%, 67%, and 77% on average for curving, northwestward-, and westward-moving tracks, respectively. Better simulations of large-scale flow dynamics contributed to these improvements, particularly in scenarios where the subtropical high underwent rapid changes in its circulation patterns. For irregular tracks, applying the SN technique showed mixed results, ranging from 75% error reduction to 20% error increase. This implies that the effectiveness of spectral nudging on the simulation of irregular tracks is case dependent. Since the effectiveness of spectral nudging depends on the scales (spectrum) of the underlying processes creating the irregularities of the tracks, when such irregularities were caused by local and regional-scale factors, spectral nudging became ineffective. Full article

The reasons why patients cannot proceed with HCT, including cases where no suitable donor is identified, remain poorly described. We reviewed all referrals for allogeneic HCT to our programme between 1 January 2019 and 31 December 2023. Of 880 patients referred for allogeneic HCT, 494 (61.8%) proceeded to transplant (mean 52 ± 14.8 years, 61.5% male) using HLA-matched unrelated (64.2%) or related (19.4%) donors and HLA-mismatched (13%) or haploidentical (3%) donors. Of patients that did not proceed with HCT (386, 38.2%), disease-related causes (54.2%), patient preference (15.8%), and significant patient comorbidity (11.4%) were the most common reasons. Eleven patients (2.9% of transplants that did not proceed; 1.3% of all referrals) lacked a suitable donor and had HLA phenotypes most associated with Caucasian (six patients, 55%), First Nations, Inuit or Metis (two patients, 18%), Black African, Caribbean or African American (one patient, 9%), Asian or Pacific Islander (9%), or unknown ethnicity (one patient, 9%). Very few patients were unable to proceed with transplant due to lack of a suitable donor; however, those cases are overrepresented by non-Caucasian ethnicity relative to the population. Full article

The market for digital assets, and more specifically cryptocurrencies, is growing, although their adoption in small island countries remains absent. This paper explores the potential benefits of integrating cryptocurrencies into portfolios alongside stocks, with a focus on Fiji’s stock market. This is the first study on a small market like Fiji, which emphasizes the role of cryptocurrencies in portfolio management. We analyze the outcomes (returns and risks) of combining cryptocurrencies with stocks using 12 different techniques. We use monthly stock returns data of 18 companies listed on the South Pacific Stock Exchange from Aug-2019 to Jun-2025 (71 months) and nine cryptocurrencies from Sept-2019 to Jun-2025 (70 months). Our main analysis shows that only one cryptocurrency, albeit with a small exposure, consistently appears in the stock-cryptocurrency portfolios in the 12 methods. Using the return-to-risk ratio across methods as a guide, we find that the stocks-cryptocurrencies portfolio based on EQW, MinVar, MaxSharpe, MinSemVar, MaxDiv, MaxDeCorr, MaxRMD, and MaxASR offers better outcomes than the stock-only portfolios. Using high returns as a guide, we find that six out of 12 methods (EQW, MaxSharpe, MaxSort, MaxCEQ, MaxOmega, and MaxUDVol) support the stocks-cryptocurrencies portfolios. Portfolios satisfying both conditions (high return-risk ratio and high return) are supported by the EQW and MaxSharpe portfolios. The consistency of assets in both stock and stock−cryptocurrency portfolios is further confirmed by 24-month out-of-sample forecasts and Monte Carlo simulations, although the latter supports small exposures in two out of the nine cryptocurrencies. Based on the results, we conclude that a small exposure to certain cryptocurrencies can strengthen diversification and improve potential returns. Full article

The giant moray eel (GME; Gymnothorax javanicus) is an important marine species that plays a key ecological role in reef systems and is a valued food source for indigenous communities. However, it is well-known that GMEs pose a food safety risk due to their ability to accumulate high levels of ciguatoxins (CTXs), the toxins known to cause ciguatera poisoning. This study assessed the age, CTX levels, elemental composition, and nutritional profile of seven GME specimens collected from Muri Lagoon, Rarotonga (Cook Islands), representing the most detailed compositional investigation on this species. Age was determined for the three largest specimens, with the oldest being 39 years old. All specimens contained ciguatoxins, with Type I (CTX4A derivatives), Type II (CTX3C derivatives), algal-ciguatoxins, and biotransformed metabolites being detected. There was a higher CTX content in the liver samples compared to flesh samples, with the longest–heaviest specimen containing the highest levels. The CTX1B level observed in flesh samples of all seven eel specimens exceeded the recommended safe guidance level proposed by the USFDA. A similar ciguatoxin profile was observed across flesh sections, with the belly flap or top loin containing the highest levels of CTXs in most specimens. No bioactive metabolites produced by co-occurring harmful microalgae, including regulated shellfish toxins, were detected. Elemental analysis determined the presence of 21 elements, including arsenic, low levels of mercury, and the volcanic elements rubidium and strontium. Nutritionally, the GMEs were shown to be a lean protein source; however, due to the ubiquitous bioaccumulation of CTXs, they pose a food safety risk to consumers. Full article

Drought is a complex and impactful natural hazard, with sometimes catastrophic impacts on small or subsistence agriculture and water security. In Pacific Island countries, there lacks an agreed approach for monitoring agricultural drought hazard with satellite-derived remote sensing data. This study addresses this gap through a framework for agricultural drought monitoring in the Pacific using freely available space-based observations. Applying World Meteorological Organization’s (WMO) recommendations and a set of objective selection criteria, three remotely sensed drought indicators were chosen and combined using fuzzy logic to form a composite drought hazard index: the Standardised Precipitation Index, Soil Water Index, and Normalised Difference Vegetation Index. Each indicator represents a subsequential flow-on effect of drought on agriculture. The index classes geographic areas as low, medium, high, or very high levels of drought hazard. To test the drought hazard index, two case studies for drought in the western Pacific, Papua New Guinea (PNG), and Vanuatu, are assessed for the 2015–2016 El Niño-related drought. Findings showed that at the height of the drought in October 2015, 58% of PNG and 72% of Vanuatu showed very high drought hazard, compared to 6% and 40%, respectively, at the beginning of the drought. The hazard levels calculated were consistent with conditions observed and events that were reported during the emergency drought period. Application of this framework to operational drought monitoring will promote adaptive capacity and improve resilience to future droughts for Pacific communities. Full article

Ammonia is a common toxic pollutant in aquaculture environments that poses significant threats to the health, growth, and survival of aquatic organisms. This study investigates the physiological and molecular responses of triploid Crassostrea gigas to ammonia exposure, focusing on the activation and regulation of oxidative stress and immune-related pathways. By integrating histological observations, biochemical assays, and transcriptomic analysis, we systematically revealed the oxidative stress and immune regulatory mechanisms in the hepatopancreas of triploid C. gigas under ammonia exposure. Results showed significant tissue damage in the hepatopancreas, disrupted activities of key antioxidant enzymes including SOD, CAT, and GSH-Px, along with elevated MDA levels, indicating oxidative damage to cellular membrane lipids. Transcriptomic data further indicated significant activation of the glutathione metabolism pathway, with antioxidant genes such as GPX5 and GPX7 displaying a dynamic pattern of initial upregulation followed by downregulation, suggesting their critical roles in modulating oxidative stress responses and maintaining cellular homeostasis. Immunologically, ammonia exposure significantly activated lysosomal and phagosomal pathways, as well as multiple signaling cascades including FOXO, mTOR, and PI3K-Akt. Several key immune regulatory genes exhibited dynamic expression changes, reflecting coordinated regulation of apoptosis, autophagy, and energy metabolism to maintain immune defense and cellular homeostasis. Notably, dynamic expression of the GADD45 gene family in the FOXO signaling pathway underscores the important role of triploid C. gigas in mounting stress responses and adaptive immune regulation under ammonia toxicity. This study provides in-depth molecular insights into the integrated response mechanisms of triploid oysters to ammonia exposure, offering a molecular foundation for understanding bivalve adaptation to ammonia and revealing novel perspectives on molluscan ammonia tolerance. Full article