Search PubMedSearch

SEARCH · Search PubMed

Results for “Southern Ocean”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

9 recordsLinked to original sources

Isolation of arboviruses (Kemerovo group, Sakhalin group) from Ixodes uriae collected at Macquarie Island, Southern ocean.

Eighty-nine pools of ticks (Ixodes [Ceratixodes] uriae White) collected at Macquarie Island (54 degrees 30' S, 159 degrees E) in the Southern Ocean yielded 16 strains of 2 viruses, 1 a "new" member of the Kemerovo group and 1 a "new" member of the Sakhalin group. The names "Nugget" and "Taggert" are proposed for them. Antigenically-related viruses have therefore now been isolated from I. uriae in both subarctic and subantarctic regions.

Animals

Microbial membrane transporters reveal trace metal niche adaptation in distinct water masses of the Southern Ocean.

BACKGROUND: Trace metals are co-factors for enzymes that are essential for microbial metabolism and the cycling of major elements. Membrane transporters allow microbes to sense and react to trace elements in the environment and to balance their uptake and export for the regulation of intracellular metal homeostasis. The acquisition and efflux of trace metals could lead to reciprocal feedbacks between microbes and the surrounding environment. Whether these processes vary among trace metals and across habitats is presently not known. We used membrane transporters into and out of the cell as indicators for the uptake and efflux of trace metals and provide a detailed picture of the distribution of the respective genes in distinct provinces in surface waters and in subsurface water masses across a transect in the Southern Indian Ocean. RESULTS: We observed marked spatial and vertical patterns in normalized gene abundances of transporters of iron (Fe), manganese (Mn), nickel (Ni) and copper (Cu). Changes in gene abundances were specific to the type of transporter and trace metal, and pronounced differences between surface and specific water masses emerged. We found an enrichment in genes related to efflux and homeostasis of Fe, Ni and Cu in two water masses of the deep ocean that are North Atlantic Deep Water (NADW) and Lower Circumpolar Deep Water (LCDW). This pattern was observed on the community level and for metagenome-assembled genomes (MAGs) affiliated with Alteromonadaceae and Burkholderiaceae that were abundant in these two water masses. CONCLUSIONS: The enrichment in trace metal efflux and resistance genes points to microbially mediated processes, exerted by homeostasis, with potential influence on the trace metal speciation and distribution in specific water masses in the deep ocean. The gene repertoire and distinct distribution pattern of the taxa identified as potential key players could reflect an adaptation to these old water masses with trace metals acting as selective driver. Video Abstract.

Membrane Transport Proteins

Temperature and Pressure Shaped the Evolution of Antifreeze Proteins in Polar and Deep Sea Zoarcoid Fishes.

Antifreeze proteins (AFPs) have enabled teleost fishes to repeatedly colonize polar seas. Four AFP types have convergently evolved in several fish lineages. AFPs inhibit ice crystal growth and lower tissue freezing point. In lineages with AFPs, species inhabiting colder environments may possess more AFP copies. Elucidating how differences in AFP copy number evolve is challenging due to the genes' tandem array structure and consequently poor resolution of these repetitive regions. Here, we explore the evolution of type III AFPs (AFP III) in the globally distributed suborder Zoarcoidei, leveraging six new long-read genome assemblies. Zoarcoidei has fewer genomic resources relative to other polar fish clades while it is one of the few groups of fishes adapted to both the Arctic and Southern Oceans. Combining these new assemblies with additional long-read genomes available for Zoarcoidei, we conducted a comprehensive phylogenetic test of AFP III evolution and modeled the effects of thermal habitat and depth on AFP III gene family evolution. We confirm a single origin of AFP III via neofunctionalization of the enzyme sialic acid synthase B. We also show that AFP copy number increased under low temperature but decreased with depth, potentially because pressure lowers freezing point. Associations between the environment and AFP III copy number were driven by duplications of paralogs that were translocated out of the ancestral locus at which AFP III arose. Our results reveal novel environmental effects on AFP evolution and demonstrate the value of high-quality genomic resources for studying how structural genomic variation shapes convergent adaptation.

Animals

Material balance analysis of trichlorofluoromethane and carbon tetrachloride in the atmosphere.

Using the historical worldwide emission and monitoring data on trichlorofluormethane, a transfer constant (0.03 yr-1) was evaluated for the movement of the gas from the troposphere to the stratosphere. The movement between the northern and southern troposphere was estimated from literature data on other gases to be 0.6 yr-1. The flux between the ocean and air was calculated using water solubility and vapor pressure measurements. These transfer constants were then combined in a dynamic material balance model which has the capability of predicting furture trends. The procedure was then applied to a similar set of data for carbon tetrachloride. The agreement between the calculated atmospheric and water concentration for carbon tetrachloride was within 20% of the actual experimental observation thus lending credence to this type of budgetary analysis.

Air Pollutants

Adolescent health across Asia Pacific, 2000-23: a systematic analysis for the Global Burden of Disease Study 2023.

BACKGROUND: The Asia Pacific region is home to more than half of the world's 1·93 billion adolescents (aged 10-24 years). Addressing adolescent health in this region is of global importance, but to date a systematic analysis of key contributors to disease in adolescents has not been done, which is a barrier to responsive action. This systematic analysis of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023 aims to provide a comprehensive assessment of adolescent health across the Asia Pacific region, at both the subregional and national levels, encompassing burden of disease, mortality, and prevalence of adolescent risk factors. METHODS: As part of GBD 2023, we obtained estimates for cause-specific mortality, disability-adjusted life-years (DALYs), and risk factor prevalence by sex for adolescents aged 10-24 years and 5-year age groups (10-14 years, 15-19 years, and 20-24 years) across 44 countries and territories (hereafter referred to collectively as Asia Pacific), grouped by seven UN subregions, from 2000 to 2023. We extracted GBD 2023 population counts and estimates of number and rate (per 100 000 population) for mortality and disease burden (DALYs). Risk prevalence estimates were obtained directly from the Institute for Health Metrics and Evaluation, and binge drinking estimates were sourced from WHO. Estimates are reported with 95% uncertainty intervals (UIs) where possible. UIs were estimated by running 250 draws of the posterior distribution, ordering the draws, and selecting the 2·5th and 97·5th percentiles for each metric. FINDINGS: In 2023, in adolescents across Asia Pacific, there were 637 496 deaths and a total disease burden of 115·8 million DALYs, representing 34·1% of global adolescent deaths and 40·6% of the global adolescent burden of disease. Non-communicable diseases (NCDs; particularly mental disorders) were the leading causes of disease burden and mortality (64·8% of DALYs and 43·9% of deaths). Unintentional and transport injuries were also leading causes of death (14·7% of deaths due to transport injury and 13·3% of deaths due to unintentional injury) and leading causes of disease burden particularly among males in south-eastern Asia. In Melanesia, Micronesia, and some parts of south-eastern Asia (Cambodia, Indonesia, Laos, the Philippines, and Timor-Leste), respiratory infections and tuberculosis remained important contributors. Southern Asia had the largest reduction (1·5% per year) in all-cause DALYs over the study period, and Australia and New Zealand (0·2% per year) had the smallest, with females in Australia and New Zealand showing a slight increase contrary to regional trends. Eastern Asia had the largest reduction (2·8% per year) in all-cause mortality rate and Melanesia (0·8% per year) the smallest. Risk factors generally had between-subregion and within-subregion variation; however, some regional trends stood out, with overweight and obesity increasing in all countries across the region, and binge drinking increasing in more countries than not. In 2023, prevalence of smoking in males exceeded that in females in every country, from 40% difference in Timor-Leste to less than 1% difference in Australia. Anaemia prevalence is decreasing in all countries, but female prevalence was higher and reducing at a slower rate than in males. Bullying prevalence was slightly higher in Polynesia, Micronesia, and Melanesia combined, Australia and New Zealand, and eastern Asia compared with southern and south-eastern Asian subregions. INTERPRETATION: Several patterns were consistent across the region: the dominance of mental disorders and NCDs, the universal rise in overweight and obesity (particularly high in Oceanic countries but increasing rapidly in south and south-eastern Asia), and persistent sex-specific challenges across subregions: unintentional injuries and smoking in males, and anaemia in females. Actions to tackle shared risk factors (while accounting for context-specific local health profiles, workforce deficits, cultural factors, and health system capacity) should not be forgone due to local variation. Future research could focus on subnational variation, intersecting inequalities, and multi-sectoral interventions targeting shared risk factors. Priority actions should include regional investment in adolescent mental health services and obesity prevention, targeted injury reduction strategies for high-risk populations, and sex-specific approaches to smoking cessation and anaemia reduction, delivered through local health systems with the capacity and cultural responsiveness to meet local needs. FUNDING: Gates Foundation and Australian Government.

Humans

Recovering the precolonial population structure of Khoe-San descendant populations.

San populations from Botswana and Namibia retain exceptional linguistic, cultural, and genetic diversity, but few Khoisan-speaking groups remain south of the Kalahari Desert. However, historically, far southern Africa was home to many San and Khoekhoe groups. Popular opinion often implies that such populations do not contribute to the ancestry of contemporary South Africans. Here, we characterize the genetic ancestry of self-identified South African Coloured groups and reconstruct precolonial and colonial population structures from 620 newly sampled individuals. These groups retain the majority of Khoe-San genetic ancestry (>48%), suggesting the persistence of Khoe-San ancestry to the present day. By isolating the Khoe-San ancestry component, we show that it is intermediate between the ≠Khomani San and Nama and distinct from Kalahari Khoe-San populations. We also find that signatures of the Indian Ocean slave trade can be traced to Indonesian islands such as Sulawesi, Java, and Flores, while the South Asian ancestry is regionally nonspecific.

Humans

Bronchial asthma in the southern Maldives.

A whole population survey was performed in Addu Atoll, southern Maldives to establish the prevalence of bronchial asthma. Assessments of atopic eczema, allergic rhinitis, conjunctivitis and intestinal infection were made, and serum specific IgE titres to a number of allergens were measured. Asthma is a common condition in the southern Maldives, and there is no evidence that the IgE produced by intestinal helminths prevents the condition.

Adolescent

Biogeographic Structure and Mitonuclear Discordance Reveal Cryptic Diversity in Pacific Herring (Clupea pallasii).

Forage fishes are biological drivers throughout the Pacific Ocean, from the Arctic to nearly subtropical latitudes. As a critical trophic link, the health and stability of Pacific herring (Clupea pallasii) populations have implications for other marine species, including several targeted by large, productive fisheries. Previous research has indicated marked divergence between Pacific herring in the Bering Sea and the Gulf of Alaska. Seeking to localize this biogeographic break, we generated low-coverage whole genome resequencing data for 120 Pacific herring from seven sites across the northern Gulf of Alaska and the eastern Bering Sea and Aleutian Islands. Single nucleotide polymorphisms across the mitogenome (267) and nuclear genome (~5.6 million) corroborate a biogeographic break in Pacific herring along the Alaska Peninsula and Aleutian Islands, as far west as Unalaska. We identified two distinct populations: one exists along the northern coasts of the Aleutian Islands and in the eastern Bering Sea; the other occupies the southern edge of the Aleutians and the Gulf of Alaska. Two mitochondrial haplogroups co-occurring across the Gulf of Alaska suggest secondary contact between two populations, likely representing glacial refugia. Our results underscore the importance of geological events to contextualize the diversification of forage fish species.

Bering Sea