Western Pacific Research Articles

Changing epidemic of tuberculosis amidst the COVID-19 pandemic in the Western Pacific Region: analysis of tuberculosis case notifications and treatment outcomes from 2015 to 2022

Coronavirus disease-2019 (COVID-19) pandemic has deeply impacted tuberculosis (TB) services globally. This study aims to assess the COVID-19 pandemic's impact on TB diagnosis and care and explore associated factors in the Western Pacific Region. We analysed TB case notifications and treatment outcomes for the Region and 14 selected countries and areas from 2015 to 2022. We further explored differences in reported cases from predicted cases by the UHC service coverage index and Human Development Index (HDI), and the relationship between the Stringency Index and TB case notifications during the pandemic. TB case notifications declined in 2020 (21%) and 2021 (23%) compared to predicted cases and partly recovered in 2022 (18%). The shortfalls in 2020 and 2021 were more prominent in priority countries with high TB burden, where the decrease in clinically diagnosed pulmonary cases and paediatric cases was particularly pronounced. In priority countries, TB case notifications have a positive relationship with UHC service coverage index and HDI in 2021 and an inverse relationship with Stringency Index during the pandemic. In contrast, treatment outcomes have not changed significantly due to the pandemic across countries in the Region. The COVID-19 pandemic has adversely impacted TB diagnosis and care in the Western Pacific Region, especially TB case detection. Stringent government policies against the pandemic, coupled with weak health systems and suboptimal socio-economic development, may have brought a more profound and prolonged impact in priority countries. The Korea Disease Control and Prevention Agency and the Japan Ministry of Health, Labour and Welfare.

Warm Arctic–Cold Eurasia (WACE) Trend: Inference from Large Ensemble Model Simulations

Abstract Concurrent with global warming, the Eurasian continent has experienced frequent cold winters in recent decades. Although still debatable, such Eurasian winter cooling, which was particularly pronounced in the late twentieth century, has been attributed to internal climate variability, the process of which remains elusive. By examining multimodel large ensemble simulations, this study explores the potential sources of internal climate variability responsible for the Eurasian winter cooling trend over 1987–2006. Model simulations show a large ensemble spread in the Eurasian winter temperature trend with an ensemble mean close to zero. A comparison of the ensemble members shows that a circulation pattern favorable for the Eurasian cooling is characterized by the anticyclonic and cyclonic enhancements of sea level pressure (SLP) trend in the subarctic and Aleutian regions, respectively. This dipolar SLP trend is closely related to the deep Arctic warming, the change in midlatitude snow cover, and the enhancement of atmospheric convection over the tropical western Pacific. This result suggests that the Eurasian winter cooling is likely associated not only to the changes in mid- to high-latitude conditions but also to the changes in tropical convection. The possible mechanism of the tropically induced Aleutian low deepening is also discussed.

Global, regional and national trends and impacts of natural floods, 1990-2022.

To assess global, regional and national trends in the impact of floods from 1990 to 2022 and determine factors influencing flood-related deaths. We used data on flood disasters from the International Disaster Database for 1990-2022 from 168 countries. We calculated the annual percentage change to estimate trends in the rates of people affected and killed by floods by study period, World Health Organization (WHO) region, country income level and flood type. We used multivariable logistic regression analysis to assess the factors associated with death from floods. From 1990 to 2022, 4713 floods were recorded in 168 countries, which affected > 3.2 billion people, caused 218 353 deaths and were responsible for more than 1.3 trillion United States dollars of economic losses. The WHO Western Pacific Region had the most people affected by floods (> 2.0 billion), accounting for 63.19% (2 024 599 380/3 203 944 965) of all affected populations. The South-East Asia Region had the most deaths (71 713, 32.84%). The African and Eastern Mediterranean Regions had the highest number of people affected and killed by floods per 100 000 population in 2022. The odds of floods causing more than 50 deaths were significantly higher in low-income countries (adjusted odds ratio: 14.34; 95% confidence interval: 7.46 to 30.04) compared with high-income countries. Numbers of people affected and mortality due to floods declined over time. Despite the decreases in populations affected and deaths, floods still have a serious impact on people and economies globally, particularly in lower-income countries. Action is needed to improve disaster risk management and flood mitigation.

The global prevalence and associated risk factors of Eimeria infection in domestic chickens: A systematic review and meta-analysis.

Eimeria is a protozoan parasite that affects poultry, particularly chickens, causing a disease known as coccidiosis. This disease imposes substantial significant economic challenges to the poultry sector. The current study aimed to estimate the global prevalence and associated risk factors of Eimeria in domestic chickens. Multiple databases (Scopus, PubMed, ProQuest, Web of Science and Google Scholar) were searched for articles published until June 2023. The pooled prevalence was estimated using a random-effects model with a 95% confidence interval. The statistical analysis was conducted using meta packages in R version (3.6.1). In total, 41 articles fulfilled the eligibility criteria. The global pooled prevalence was 44.3% (36.9%-51.8%) with Eimeria tenella (38.7%, 30.1%-47.7%) as the most prevalent species. The highest pooled prevalence was related to the Western Pacific Region (80.5%, 72.6%-87.3%) and urban areas (44.4%, 36.5%-52.6%). Moreover, areas with humid subtropical climates represent the highest overall prevalence (75.8%, 46.6%-95.9%). The necessity for robust and innovative strategies for preventing and managing this disease cannot be overstated. Addressing Eimeria impact is crucial not only for safeguarding poultry health but also for sustaining the economic viability of the poultry industry.

In‐situ U‐Pb dating of calcite slickenfibre constraints on Cenozoic multiple‐phase faulting along the eastern segment of Chengkou Fault, Dabashan Fold‐and‐Thrust Belt

AbstractThe Dabashan Fold‐and‐Thrust Belt is an important natural laboratory for exploring the Meso‐Cenozoic intracontinental orogenic evolution in China. Due to the severe lack of post‐Early Cretaceous strata, little attention has been paid to Cenozoic tectonic in the Dabashan. This study presents structural analysis, in‐situ U‐Pb dating of calcite in conjunction with petrographic and stable isotopic analyses along the eastern segment of the Chengkou Fault in the Dabashan. Structural analysis coupled with U‐Pb dating of syn‐kinematic calcite slickenfibres suggests two discrete S‐N compressional strike‐slip deformation events associated with localized E‐W extension along the eastern segment of the Chengkou Fault have occurred at the Early Eocene (~57–50 Ma) and Late Oligocene‐Early Miocene (~23–17 Ma), respectively. We tentatively related the Cenozoic deformation events in the study area to the clockwise rotation of the Sichuan Basin, resulting from the combined far‐field stress effects between the India, Eurasia and western Pacific plates.

Potential impacts of reduced winter Kara Sea ice on the dipole pattern of cold surge frequency over the tropical western Pacific

The impact of Arctic Sea ice melting on weather and climate extremes in the Northern Hemisphere has garnered widespread attention. Existing research has convincingly demonstrated the importance of this impact in mid-high latitudes, while its influence in areas beyond remains controversial. This study reveals the indirect influence of Kara Sea ice reduction on cold surge (CS) over the tropical western Pacific (TWP), with the East Asian jet stream serving as the connecting link. The leading mode of CSs over the TWP exhibits a zonal dipole characteristic, which is associated with cyclonic anomaly over the Philippine Sea. The enhanced cyclonic anomaly is caused by strengthened and northward-moved subtropical East Asian jet stream and weakened polar jet stream, which can lead to more CSs over the South China Sea and fewer CSs over the Philippine Sea. Such variations in the jet stream are contributed by the facilitated atmospheric blockings west of the Ural Mountains, which suppressed the circumpolar westerly winds and increased meridional temperature gradient in Northeast Asia. The connection between atmospheric blockings and Kara Sea ice can be confirmed through local vertical energy exchange. Simulations of the atmospheric response to the forcing of decreased Kara Sea ice support the proposed connection. Although there is no statistically significant correlation between tropical CSs and Kara Sea ice, this study highlights the potential impacts of Arctic climate change signal on weather and climate extremes over tropical regions.

Uniformly elevated future heat stress in China driven by spatially heterogeneous water vapor changes

The wet bulb temperature (Tw) has gained considerable attention as a crucial indicator of heat-related health risks. Here we report south-to-north spatially heterogeneous trends of Tw in China over 1979-2018. We find that actual water vapor pressure (Ea) changes play a dominant role in determining the different trend of Tw in southern and northern China, which is attributed to the faster warming of high-latitude regions of East Asia as a response to climate change. This warming effect regulates large-scale atmospheric features and leads to extended impacts of the South Asia high (SAH) and the western Pacific subtropical high (WPSH) over southern China and to suppressed moisture transport. Attribution analysis using climate model simulations confirms these findings. We further find that the entire eastern China, that accommodates 94% of the country’s population, is likely to experience widespread and uniform elevated thermal stress the end of this century. Our findings highlight the necessity for development of adaptation measures in eastern China to avoid adverse impacts of heat stress, suggesting similar implications for other regions as well.

Changes in diazotrophic community structure associated with Kuroshio succession in the northern South China Sea

Abstract. Kuroshio intrusion (KI) is a key process that transports water from the western Pacific Ocean to the northern South China Sea (nSCS), where KI-induced surface water mixing often causes variations in microbial assemblages. Yet, how interannual KIs affect the biogeography of diazotrophs and associated environmental factors remains poorly characterized. Here, by quantifying the degree of KIs in 2 consecutive years, coupled with monitoring the diversity and distribution of nitrogenase-encoding nifH phylotypes with quantitative PCR and high-throughput sequencing, we show that changes in the diazotrophic community structure in the nSCS are highly correlated with KI-induced variations in a range of physicochemical parameters. Specifically, the filamentous cyanobacteria in the genus Trichodesmium were more abundant at stations strongly affected by KI and thereby with a deeper mixed layer and higher surface salinity and temperature; the unicellular N2-fixing cyanobacteria in group B (UCYN-B) were more abundant at stations least affected by KI and correlated with nutrient availability, whereas UCYN-C and the γ-proteobacteria were prevalent at stations moderately affected by KI. The neutral community model further demonstrated that dominant diazotrophic subcommunities were significantly affected by environmental factors in 2017 when KI was stronger compared to 2018 when KI retreated. Our analyses provide insightful evidence for the role of KI in shaping the diazotrophic community structure primarily as a stochastic process, implying a potential region-scale redistribution of diazotrophs and nitrogen budget, given that KIs are projected to intensify in a future warming ocean.

The genus Adontorhina (Bivalvia: Thyasiridae) from the northern Pacific Ocean: Description of two new species, an expanded description of Adontorhina cyclia S. S. Berry, 1947, and remarks on other species

We describe two new deep-sea species of bivalves of the genus Adontorhina that were found at a depth of 788–2532 m off the Kuril Islands and the southeastern coast of the Kamchatka Peninsula (Adontorhina inflata sp. nov.), as well as at a depth of 3210–3432 m in the Sea of Okhotsk and on the oceanic slope of the Kuril Islands (Adontorhina diaphana sp. nov.). Herein, we provide an expanded description of the amphi-Pacific Adontorhina cyclia, which is supplemented with new data on shell morphology, body anatomy, and distribution, based on the analysis of samples collected by 12 expeditions between 1949 and 2015 in various regions of the northwestern Pacific from the coast of Japan to the Bering Sea. The main feature distinguishing the new species from all other Adontorhina species is a unique sculpture of the prodissoconch consisting of thin folds and wrinkles of varying length, shape, and number. In addition, A. inflata sp. nov. differs from other Adontorhina species by having an obliquely ovate, strongly inflated shell with a poorly defined escutcheon and indistinct auricle; and A. diaphana sp. nov. is distinguished by having a subcircular shell with a long and strongly prominent auricle. A thorough study of the prodissoconch morphology of A. cyclia from the western and eastern Pacific, as well as Adontorhina sphaericosa and Adontorhina zelayi, showed that the sculpture of the prodissoconch in all species studied is unique and can be used as an important additional character for the identification and differentiation of Adontorhina species.

Classification of sound speed fields in the Western Pacific Ocean based on tensor decomposition

The three-dimensional (3-D) sound speed structure of the ocean is a fundamental environmental element in studying underwater sound propagation modeling and forecasting. The accurate classification of the sound speed fields (SSFs) provides a comprehensive understanding and analysis of the sound propagation pattern. To take advantage of the 3-D structure of the ocean SSFs, this paper presents a quick method based on tensor decomposition for classifying the ocean 3-D SSFs. Utilizing the WOA18 dataset, High Order Iterative Orthogonal (HOOI) decomposition of the 3-D SSFs is executed so as to accurately extract the characteristic information of the SSFs. The Fuzzy C-Means clustering (FCM) method is applied to classify the feature tensors, partitioning of regional categories in different seasons and revealing the typical SSFs structures. By combining the BELLHOP model with analysis of the characteristics of the first convergence zone of each category, it is concluded that there are six categories of SSFs in the Western Pacific Ocean. The SSFs across all categories are primarily latitudinally distributed, featuring distinct sound channel axes and surface sound speed variations.

Long-Term and Seasonal Changes in Emission Sources of Atmospheric Particulate-Bound Pyrene and 1-Nitropyrene in Four Selected Cities in the Western Pacific

Abstract: Estimating the source contribution to polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in the atmosphere is necessary for developing effective disease control and pollution control measures. The NPAH-PAH combination method (NP method) was used to elucidate the contributions of vehicles and coal/biomass combustion to seasonal and long-term urban atmospheric particulate matter (PM)-bound Pyr and 1-NP concentrations in Kanazawa, Kitakyushu, Shenyang and Shanghai in the Western Pacific region from 1997 to 2021. Among the four cities, Kanazawa demonstrated the lowest Pyr concentration. The contribution of vehicles to Pyr before and after 2010 was 35% and 5%, respectively. The 1-NP concentration was reduced by a factor of more than 1/10. These changes can be attributed to the emission control from vehicles. Kitakyushu revealed the second-lowest Pyr and the lowest 1-NP concentrations. Coal combustion was found to be the main contributor to Pyr, while its contribution to 1-NP increased from 9% to 19%. The large contribution of coal combustion is attributed to iron manufacturers. Shenyang demonstrated the highest atmospheric Pyr concentration with its largest seasonal change. Vehicles are the largest contributors to 1-NP. However, coal combustion, including winter coal heating, contributed 97% or more to Pyr and more than 14% to 1-NP. Shanghai revealed the second-highest Pyr and 1-NP concentrations, but the former was substantially lower than that in Shenyang. Coal combustion was the major contributor, but the contribution of vehicles to Pyr was larger before 2010, which was similar to Kanazawa.

Asymmetric El Niño–Southern Oscillation and tropical cyclone relationships in the Philippines during October–December

AbstractThis study demonstrates asymmetric relationships between El Niño–Southern Oscillation (ENSO) and tropical cyclones (TCs) affecting the Philippines during October–December. In El Niño or La Niña years, the number of TCs impacting the Philippines may increase or decrease. These variations result in four ENSO–TC variability types all of which exhibit strong sea surface temperature (SST) anomalies across the equatorial eastern Pacific. The major difference between the active and inactive types in terms of El Niño or La Niña years is related to the magnitude of SST anomalies in the tropical western Pacific (TWP) over the 120°–150°E region. During El Niño years, moderate cold SST anomalies in this TWP region cause an anomalous divergent centre around the 120°–130°E zone to evoke an anomalous cyclone east of the Philippines. In the western North Pacific (WNP), this anomalous cyclone causes more TCs to form and move toward the Philippines, resulting in active TC activity. For the inactive TC type during El Niño years, very weak cold SST anomalies in the aforementioned TWP region correspond with a northeastward‐extended anomalous divergent centre over the 120°–140°E, 10°S–20°N zone and an anomalous anticyclone across the Philippines and its eastern side. Decreases in the formation of the WNP TC and movement toward the Philippines lead to inactive TC activity. The large‐scale anomalies and regulating processes are mainly opposite between the active TC type during El Niño years and the inactive TC type during La Niña years. These two types are influenced by interdecadal variability of the Pacific decadal oscillation. Opposite anomalies and regulating processes also occur between the inactive TC type during El Niño years and the active TC type during La Niña years. The former type is jointly modulated by the positive Indian Ocean Dipole mode and central‐Pacific El Niño.

Late Oligocene–Miocene evolution of deep-water circulation in the abyssal South China Sea: Insights from Nd isotopes of fossil fish teeth

Abstract A long-term neodymium isotope (εNd) record of fossil fish teeth was investigated to constrain the evolution of deep-water circulation in the abyssal South China Sea (SCS) during the late Oligocene–Miocene (27–10 Ma). Fish teeth samples were collected from the oceanic red beds at International Ocean Discovery Program Expedition 367 Site U1499 (water depth 3758 m). Seawater εNd values (from –7.1 to –4.8, average –6.1) prior to 15 Ma indicate that water masses in the abyssal SCS resulted from the mixing of more radiogenic Upper Circumpolar Deep Water (UCDW, average –4.5) and less radiogenic Lower Circumpolar Deep Water (LCDW, average –6.4). The general decrease in εNd values was attributed to an increasing influence of the unradiogenic LCDW at the studied site, consistent with the subsidence and the associated deepening of the SCS plain. After 15 Ma, seawater εNd dropped significantly to a range of –8.9 to –6.1 (average –7.5), indicating a slowdown in the hydrological connection between the deep-water masses in the SCS and the western Pacific Ocean. We argue that the formation of the Luzon Strait due to the uplift of the Luzon arc in the late Miocene led to the shallowing and narrowing of the SCS-Pacific channels. Consequently, penetration of LCDW was reduced and water masses in the abyssal SCS would have been less ventilated and strongly influenced by lithogenic input from the unradiogenic sediments of large Asian rivers draining the peri-Himalayan region.

A review of the varunid crab genus Parapyxidognathus Ward, 1941 (Decapoda: Brachyura: Varunidae), with descriptions of two new species

Abstract Species of Parapyxidognathus Ward, 1941 are distributed across tropical Indo-West Pacific to temperate downstream rivers and in estuaries. The genus previously included only one species, Parapyxidognathus deianira (De Man, 1888). We examined specimens from Parapyxidognathus and its closely related genus, Pyxidognathus A. Milne-Edwards, 1879 from the eastern Indian Ocean and western Pacific, focusing on their morphological characters. The results also support the reclassification of Pyxidognathus fluviatilis Alcock, 1900 into Parapyxidognathus, as well as the establishment of two new species from the western Pacific, Pa. tshiansuesp. nov. and Pa. ongiasp. nov. The identity of the species is supported by evidence from mitochondrial 16S rDNA and cytochrome oxidase subunit 1 (COI) genes. There are now four species in Parapyxidognathus distinguishable by the characters of the anterolateral teeth of the carapace, the pleon, and the first gonopods of the male, and the female vulvae.

Centres of Development and Patterns of Distribution of the Family Melastomataceae in Indo-Malesia

1.The Melastomataceae is a homogeneous family of about 220 genera and 5300 species and is generally confined to the tropical and subtropical regions, avoiding arid conditions and attaining prolific developments in the rain forests between the tropic of cancer and the tropic of capricorn. More than one half of the World's melastomataceous genera (about 120) and two-thirds of the total number of species (about 3353) are confined to the New World. The melastomataceous flora of Indo-Malesia consists of 64 genera and about 1300 species. In the Old World the incidence of melastomataceous species for Indo-Malesia and Africa is in the ratio of 2:1.2.The present distribution of Melastomataceae in both the New World and the Old World is discussed on the basis of Wegener's hypothesis of "Continental Drift". Instead of considering the island of Madagascar as the centre of origin of the family in a restricted way, it is considered that "Gondwanaland" was ideally suited for the melastomataceous flora and those blocks that moved away after the breaking up of this huge continental mass in the Late Cretaceous, each carried their own share of melastomataceous species which, after gradual establishment in new situations during a long span of time and space, proliferated into several new taxa by an intensive process of evolution.3.The Deccan Peninsula + Ceylon block in drifting over the Indian Ocean must have carried the original Gondwanaland stock and gene-pool of the Melastomataceae which later-when this block was fused with Laurasia and the Tethys Sea had disappeared-became the centre of development of the family in continental Asia. Then Melastomataceae could further develop on the southern part of Laurasia and from there migrate eastward to the Malesian islands, the Western Pacific and northern Australia.This implies the conclusion that, though Australia also formed part of the ancient Gondwanaland, this cannot have carried part of the ancient Gondwanaland Melastomataceae when Australia drifted apart.4.An attempt has been made to assess the centres of distribution of Indo-Malesian Melastomataceae and from this study the following four centres of development are proposed : (i) The Deccan-Ceylon centre, (ii) The Himalayan-Yunnan centre, (iii) The Sunda centre and (iv) The Philippine-Papuan centre.5.The Island of Borneo is unique in having the largest number of genera-42 out of the Indo-Malesian total of 64 genera-and the largest number of species i.e. 257. Perhaps, it is due to the part played by the mountain of Kinabalu in enriching the floristic composition of Borneo. It is generally considered by phytogeographers that Kinabalu is a great sanctuary of flora, past and present, and a nursery of endemic elements.

Simulating drifting fish aggregating device trajectories to identify potential interactions with endangered sea turtles.

Purse-seine fishers using drifting fish aggregating devices (dFADs), mainly built with bamboo, plastic buoys, and plastic netting, to aggregate and catch tropical tuna, deploy 46,000-65,000 dFADs per year in the Pacific Ocean. Some of the major concerns associated with this widespread fishing device are potential entanglement of sea turtles and other marine fauna in dFAD netting; marine debris and pollution; and potential ecological damage via stranding on coral reefs, beaches, and other essential habitats for marine fauna. To assess and quantify the potential connectivity (number of dFADs deployed in an area and arriving in another area) between dFAD deployment areas and important oceanic or coastal habitat of critically endangered leatherback (Dermochelys coriacea) and hawksbill (Eretmochelys imbricata) sea turtles in the Pacific Ocean, we conducted passive-drift Lagrangian experiments with simulated dFAD drift profiles and compared them with known important sea turtle areas. Up to 60% of dFADs from equatorial areas were arriving in essential sea turtle habitats. Connectivity was less when only areas where dFADs are currently deployed were used. Our simulations identified potential regions of dFAD interactions with migration and feeding habitats of the east Pacific leatherback turtle in the tropical southeastern Pacific Ocean; coastal habitats of leatherback and hawksbill in the western Pacific (e.g., archipelagic zones of Indonesia, Papua New Guinea, and Solomon Islands); and foraging habitat of leatherback in a large equatorial area south of Hawaii. Additional research is needed to estimate entanglements of sea turtles with dFADs at sea and to quantify the likely changes in connectivity and distribution of dFADs under new management measures, such as use of alternative nonentangling dFAD designs that biodegrade, or changes in deployment strategies, such as shifting locations.

A high-resolution seismic velocity model for East Asia using full-waveform tomography: Constraints on India-Asia collisional tectonics

East Asia's complex tectonic history makes it a unique place for plate-tectonic studies. While the crust and mantle structures beneath this region have been extensively investigated by receiver function and many different kinds of tomography studies, discrepancies among seismic velocity models have complicated our understanding of East Asia's tectonic evolution. Here, we use full-waveform adjoint tomography to study the seismic P- and S-wave velocity structures of the crust and mantle beneath East Asia. We use a large waveform dataset from 141 earthquakes recorded by 4640 broadband seismic stations. Our inversion optimizes the normalized correlation coefficient between synthetic and observed seismograms within individual time windows of different seismic phases, from P arrivals to the slowest surface waves. This approach allows us to fit regional multipathed waveforms and provides very well-resolved seismic P- and S-wave velocity structures from the crust to depths of about 800 km. Furthermore, we are able to obtain this resolution over most of East Asia allowing us to compare the amplitude and shapes of anomalies across the entire region. The observed structures in our new full-waveform tomography model (FWEA23) correlate well with tectonic units, revealing sharp contrasts across tectonic boundaries. Our model reveals narrow and strong linear fast anomalies associated with subduction zones in the western Pacific and Southeast Asia. Compared to these oceanic slabs, we observe different and more complicated mantle structures beneath the India-Asia continental collision zone. While our model spans a wide region in East Asia, we focus our interpretations on the seismic velocity anomalies beneath Tibet and surrounding regions, as our model provides significant implications for India-Asia continental collision tectonics. Our analysis suggests that cratonic Indian lithosphere collided with Eurasian plate around 25–20 Ma, subsequently underthrusting beneath Tibet horizontally with little deformation. This resulted in thickening, destabilization, and delamination of the rheologically weaker and less buoyant mantle lithosphere beneath north-central Tibet. Moreover, our model reveals isolated lithospheric fragments within the mantle transition zone and lower mantle beneath southern Tibet and northern India, suggesting that non-cratonic Greater India continental lithosphere has broken off and sunk into the deeper mantle. The lack of continuity among these lithospheric fragments suggests a convective destabilization process, distinct from typical oceanic plate subduction. Our results emphasize the important role of rheological properties of continental lithospheres in shaping the dynamics of continental collision.

Application of multiplatform remote sensing data over East Asia Ocean: aerosol characteristics and aerosol types.

It is important to explore the characteristics and rules of atmospheric aerosol in the East Asian Sea for monitoring and evaluating atmospheric environmental quality. Based on Aerosol Robot Network (AERONET), Visible Infrared Imaging Radiometer (VIIRS), and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data, the temporal and spatial variation characteristics and differences of aerosol parameters and types in the East Asian Sea were studied by using figure classification method (FIGCM), aerosol optical depth (AOD)440-Angstrom exponent (AE)440-870 method (AA1M), and AOD550-AE490-670 method (AA2M). The results show that the seasonal variation trend of aerosol characteristics and types is obvious in East Asia Sea. AOD, volume concentration (Cv), and aerosol effective radius (reff) in the Bohai-Yellow Sea and the Sea of Japan in autumn are lower than those in other seasons, and the occurrence frequency of ocean-type aerosols is high. Different from the Bohai-Yellow Sea and Sea of Japan, human activities in winter, summer, and autumn seriously affect the air quality in the East China Sea and South China Sea. Especially at the Taipei CWB site, from aerosol parameters and high biomass burning/urban industrial (BB/UI) aerosol, human activity is an important factor for high pollution at the Taipei CWB site. Aerosol types of AA1M, FIGCM, AA2M, and CALIPSO were compared at Anmyon and Yonsei University sites in the Bohai-Yellow Sea in March 2020. The results show that aerosol types based on threshold classification methods generally have higher mixed aerosol results, and the marine (MA) results of AA1M, FIGCM, and AA2M are close to the clean marine aerosol results of CALIPSO. Comparing the results of AA 2M and CALIPSO on a spatial scale, it is found that the clean marine aerosol proportion identified by CALIPSO (0.38, 0.48, 0.82) is consistent with the MA proportion identified by AA 2M (0.43, 0.46, 0.97) in the East China Sea, South China Sea, and Western Pacific Ocean.

'Microcosm of the Pacific': Colonial encounters at the Central Medical School in Fiji.

While larger British colonies in Africa and Asia generally had their own medical services, the British took a different approach in the South Pacific by working with other colonial administrations. Together, colonial administrations of the South Pacific operated a centralised medical service based on the existing system of Native Medical Practitioners in Fiji. The cornerstone of this system was the Central Medical School, established in 1928. Various actors converged on the school despite its apparent isolation from global centres of power. It was run by the colonial government of Fiji, staffed by British-trained tutors, attended by students from twelve colonies, funded and supervised by the Rockefeller Foundation, and jointly managed by the colonial administrations of Britain, Australia, New Zealand, France and the United States. At the time of its establishment, it was seen as an experiment in international cooperation, to the point that the High Commissioner for the Western Pacific called it a 'microcosm of the Pacific'. Why did the British establish an intercolonial medical school in Oceania, so far from the imperial metropole? How did the medical curriculum at the Central Medical School standardise to meet the imperial norm? And in what ways did colonial encounters occur at the Central Medical School? This article provides answers to these questions by comparing archival documents acquired from five countries. In doing so, this article will pay special attention to the ways in which this medical training institution enabled enduring intercolonial encounters in the Pacific Islands.

Bringing light into deep-sea biodiversity: a systematic revision and molecular phylogeny of the genus Scaphander Montfort, 1810 (Gastropoda: Cephalaspidea), with a focus on the Indo-Pacific

Abstract Scaphander is a genus of mostly deep-sea, soft-bottom gastropods distributed nearly worldwide. Its taxonomic history is complex, with 32 species currently accepted, most based on shells only. In this work, we revise the diversity and systematics of Scaphander, with a focus on the Indo-Pacific region, using a detailed morphological study and molecular phylogenetics. Conchological and anatomical characters, such as digestive and male reproductive systems were compared, and original descriptions and type material were investigated. Additionally, molecular species delimitation methods were used, such as Assemble Species by Automatic Partitioning (ASAP) based on the gene cytochrome c oxidase subunit I, and the multispecies coalescent method Species Tree And Classification Estimation, Yarely (STACEY) based on a dataset of five gene markers. Thirty-three Scaphander species were recognized worldwide, 10 still based only on shells. Five species are here described as new to science, namely Scaphander amygdalus sp. nov., Scaphander cornus sp. nov., Scaphander obnubilus sp. nov., Scaphander semicallus sp. nov. and Scaphander solomonensis sp. nov. The most diverse region is the Western Pacific (17 species), followed by the Atlantic (12 species) and the Indian Ocean (7 species).