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1.
Sci Rep ; 14(1): 20458, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39227424

RESUMEN

Sea level rise (SLR) poses a significant threat to coastal regions worldwide, particularly affecting over 60 million people living below 10 m above sea level along the African coast. This study analyzes the spatio-temporal trends of sea level anomaly (SLA) and its components (thermosteric, halosteric and ocean mass) in the Eastern Tropical Atlantic Ocean (ETAO) from 1993 to 2022. The SLA trend for the ETAO, derived from satellite altimetry, is 3.52 ± 0.47 mm/year, similar to the global average of 3.56 ± 0.67 mm/year. Of the three upwelling regions, the Gulf of Guinea (GoG) shows the highest regional trend of 3.42 ± 0.12 mm/year. Using the ARMORD3D dataset, a positive thermosteric sea level trend of 0.88 ± 0.04 mm/year is observed, particularly in the equatorial and southern Atlantic regions. The steric component drives the interannual SLA variability, while the ocean mass component dominates the long-term trends, as confirmed by the GRACE and GRACE-FO missions for 2002-2022. For those two decades, the total SLR from altimetry amounts to 3.80 ± 0.8 mm/year, whilst the steric component is reduced to only 0.19 ± 0.05 mm/year, leaving a residual increase in the ETAO of 3.69 ± 0.5 mm/year. The independent mass change from GRACE amounts to 2.78 ± 0.6 mm/year for this region, which just closes the sea level budget within present uncertainty levels. Spatial analysis of the steric components indicates a warming along the equatorial African coast including the GoG and a freshening near Angola. Strong correlations with regional climate factors, particularly the Tropical South Atlantic Index, highlight the influence of persistent climate modes. These findings underscore the urgent need for mitigation and adaptation strategies to SLR in the ETAO, especially for densely populated coastal communities.

2.
Sci Total Environ ; 952: 175897, 2024 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-39222811

RESUMEN

Due to the lack of relatively long-term, high-resolution terrestrial records in tropical southern China, there is limited published research on terrestrial vegetation changes and their responses to regional and/or global climate forcings since the last glacial period. In this study, a 170-cm-long peat core (covering the interval from ~44.1 to 9.3 cal kyr BP) recovered from the Xialu peatland in Leizhou Peninsula, South China, was analyzed for organic carbon isotope (δ13Corg), along with total organic carbon, total nitrogen, and bulk dry density, to investigate past vegetation and hydroclimatic changes. Our results showed that C4 plants dominated the study region during Marine Isotope Stage (MIS) 2 (29-14 cal kyr BP), indicating generally cooler and drier conditions during MIS 2 relative to late MIS 3 (~ 44.1-29 cal kyr BP) and early MIS 1 (14-9.3 cal kyr BP). In particular, the driest conditions occurred during the Last Glacial Maximum (~ 25-19 cal kyr BP) when sea level was at its lowest. In addition, several millennial-scale climatic events associated with the expansion of C4 plants were clearly identified. Our record is sensitive to a variety of glacial-interglacial forcings, including regional processes and global forcing, among which the inundation history of Beibu Gulf due to sea-level change during the late Quaternary, which has been neglected in previous studies, may have played an important role in modulating paleo-hydroclimatic changes in tropical southern China.

3.
Sci Total Environ ; 952: 175962, 2024 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-39233084

RESUMEN

Tidal dynamics are a well-known driver of mangrove distribution, with most predictive measures using some form of tidal parameter (tidal plane or hydroperiod) to define mangrove extent. However, these methods often fail to consider the causative reason why mangroves thrive or perish at a specific elevation or how mangrove survivability thresholds can differ across a species' lifecycle. The lack of understanding of the drivers influencing mangrove establishment has resulted in poor success rates for mangrove restoration and creation projects worldwide. A novel mangrove lifecycle model that uses a multi-forcing threshold approach is proposed to simulate Avicennia marina viability across establishment and development phases. The lifecycle model includes critical threshold stages for reproduction, seed dispersal, seedling establishment and development, and mature tree survival. The model was validated at 37 sites in eastern Australia to predict mangrove extent across various estuary types and tidal dynamic conditions. The model accurately calculated the upper (RMSE = 0.0676, R2 = 0.8932) and lower (RMSE = 0.0899, R2 = 0.7417) mangrove surface elevations, providing physiological reasoning for establishment and development. Based on the various conditions tested, the model results highlight the highly dynamic spatial and temporal conditions where Avicennia forests thrive. It was found that stressors influencing mangrove establishment were the primary factor for mangrove extent across all sites. However, estuarine typology is important in forcing threshold limits and establishment opportunities. Estuaries with limited tidal decay (from the oceanic forcing) provide more opportunities for mangroves to establish than estuaries with significant tidal attenuation. Regardless of estuary typology, all sites tested had substantial spatial variability through time. Results from the lifecycle model suggest that mature Avicennia forests establish and thrive under a wide range of hydrologic conditions. This resilience suggests that mature mangroves may be able to withstand increases in climatic and hydrologic pressures via biophysical adaptations, although the upper thresholds and acceptable rates of change are difficult to predict. Overall, this study highlights the value of a new causal method for estimating mangrove extent across various lifecycle stages, locations, and time periods.


Asunto(s)
Avicennia , Humedales , Avicennia/fisiología , Monitoreo del Ambiente/métodos , Australia
4.
Ecol Evol ; 14(9): e70238, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39290665

RESUMEN

Oysters are ecosystem engineering species building reef-like biogenic structures in temperate shallow water environments, serving as biodiversity hotspots. Recently, also their ecosystem services such as fish nursery, pollutants sink and self-sustaining coastal protection mechanisms came into a research focus. In light of accelerated sea level rise and increasing environmental dynamics, a determination of vertical growth rates of these biosedimentary structures is paramount in assessing their resilience. This study embarked on a comprehensive survey of seasonal vertical reef growth rates using terrestrial laser scanning and related population dynamics of two intertidal reefs built by the non-native oyster Magallana gigas in the Wadden Sea. We quantified median reef growth at 19.8 mm yr-1 for the Kaiserbalje reef and 17.5 mm yr-1 for the Nordland reef. Additionally, we tested the hypothesis that the seasonal variations in reef growth rates correspond to the local population dynamics, mainly the parameters of shell length and abundance which mirror delayed effects from previous spawning events. Shell growth rates were 0.03-0.06 mm d-1 in winter and 0.10-0.16 mm d-1 in summer, mean oyster abundance from autumn 2019 to spring 2022 was 627 ± 43 ind. m-2 and 338 ± 87 ind. m-2 at the Kaiserbalje and Nordland reefs respectively. Minor reef growth in the topmost reef area reflects an emerging equilibrium of the vertical reef position to actual sea level. Our findings are in accordance with growth of natural Crassostrea virginica reefs on the US East Coast, indicating potential resilience to actual and predicted sea level rise scenarios. Moreover, understanding local hydro-morphodynamic feedback linked to sea level rise will be vital in predicting the three-dimensional stability of these biosedimentary structures and habitats.

5.
Sci Total Environ ; 951: 175523, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-39147058

RESUMEN

This study addresses the urgent need to understand the impacts of climate change on coastal ecosystems by demonstrating how to use the SWAT+ model to assess the effects of sea level rise (SLR) on agricultural nitrate export in a coastal watershed. Our framework for incorporating SLR in the SWAT+ model includes: (1) reclassifying current land uses to water for areas with elevations below 0.3 m based on SLR projections for mid-century; (2) creating new SLR-influenced land uses, SLR-influenced crop database, and hydrological response units for areas with elevations below 2.4 m; and (3) adjusting SWAT+ parameters for the SLR-influenced areas to simulate the effects of saltwater intrusion on processes such as plant yield and denitrification. We demonstrate this approach in the Tar-Pamlico River basin, a coastal watershed in eastern North Carolina, USA. We calibrated the model for monthly nitrate load at Washington, NC, achieving a Nash-Sutcliffe Efficiency (NSE) of 0.61. Our findings show that SLR substantially alters nitrate delivery to the estuary, with increased nitrate loads observed in all seasons. Higher load increases were noted in winter and spring due to elevated flows, while higher percentage increases occurred in summer and fall, attributed to reduced plant uptake and disrupted nitrogen cycle transformations. Overall, we observed an increase in mean annual nitrate loads from 155,000 kg NO3-N under baseline conditions to 157,000 kg NO3-N under SLR scenarios, confirmed by a statistically significant paired t-test (p = 2.16 × 10-10). This pioneering framework sets the stage for more sophisticated and accurate modeling of SLR impacts in diverse hydrological scenarios, offering a vital tool for hydrological modelers.

6.
Mar Pollut Bull ; 207: 116889, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39216257

RESUMEN

Saltwater problems in the Nandu River have gradually intensified in recent years. The effect of runoff variability (RV) on saltwater intrusion has not yet been fully revealed. Long-term trends in runoff and sea level (SL) were analyzed using the Mann-Kendall test and Theil-Sen estimation, and salinity exceedance rates (Ps) were calculated based on MIKE 11 and daily runoff distributions. As RV increased, Ps decreased the most at 16.0 km (6.7 %) and increased the most at 23.2 km (5.3 %). SL increased by 0.4 m and Ps increased the most at 20.5 km (11.7 %). Constant Ps is projected to move downstream by the 2060s and 210 s, with maximum increases in Ps of 6.2 % and 10.1 %, respectively. The ratio of changes in Ps due to changes in RV and SL is about 0.85. Constant Ps sections can be used to assess the risk of saline intrusion in some of the world's estuaries.


Asunto(s)
Monitoreo del Ambiente , Ríos , Salinidad , Ríos/química , China , Monitoreo del Ambiente/métodos , Movimientos del Agua , Estuarios , Agua de Mar/química
7.
Environ Monit Assess ; 196(9): 822, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39158731

RESUMEN

Nowadays, within the built environment, railway infrastructures play a key role to sustain national policies oriented toward promoting sustainable mobility. For this reason, national institutions and infrastructure managers need to increase their awareness in relation to the current and future climate risks on their representative systems. Among climate change impacts, preventing the effects of sea-level rise (SLR) on coastal railway infrastructures is a priority. The first step in the climate change adaptation policy cycle is the development of an ad hoc climate risk assessment. In this view, this research develops a vulnerability and a risk assessment metric to identify the hotspots within a national coastal railway due to the SLR impacts. The proposed methodology required different steps to quantify the SLR projections and the vulnerability characteristics of the assets, in terms of sensitivity and adaptive capacity. The investigated case study is the coastal railway infrastructure in Italy, thanks to an initial approach of co-design participative processes with the national Infrastructure Manager: Rete Ferroviaria Italiana (RFI). The results of this application, although not included in the paper due to confidential reasons imposed by the infrastructure manager - led to a clear identification of the areas and the coastal railway sections which are exposed to high levels of risks and of the places which require priority actions for urgent adaptation in a view of climate proof infrastructures.


Asunto(s)
Cambio Climático , Monitoreo del Ambiente , Vías Férreas , Elevación del Nivel del Mar , Italia , Medición de Riesgo/métodos , Monitoreo del Ambiente/métodos
8.
Proc Natl Acad Sci U S A ; 121(32): e2310077121, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39074269

RESUMEN

Climate change is an existential threat to the environmental and socioeconomic sustainability of the coastal zone and impacts will be complex and widespread. Evidence from California and across the United States shows that climate change is impacting coastal communities and challenging managers with a plethora of stressors already present. Widespread action could be taken that would sustain California's coastal ecosystems and communities. In this perspective, we highlight the main threat to coastal sustainability: the compound effects of episodic events amplified with ongoing climate change, which will present unprecedented challenges to the state. We present two key challenges for California's sustainability in the coastal zone: 1) accelerating sea-level rise combined with storm impacts, and 2) continued warming of the oceans and marine heatwaves. Cascading effects from these types of compounding events will occur within the context of an already stressed system that has experienced extensive alterations due to intensive development, resource extraction and harvesting, spatial containment, and other human use pressures. There are critical components that could be used to address these immediate concerns, including comanagement strategies that include diverse groups and organizations, strategic planning integrated across large areas, rapid implementation of solutions, and a cohesive and policy relevant research agenda for the California coast. Much of this has been started in the state, but the scale could be increased, and timelines accelerated. The ideas and information presented here are intended to help expand discussions to sharpen the focus on how to encourage sustainability of California's iconic coastal region.

9.
J Environ Manage ; 365: 121589, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38963969

RESUMEN

Subsurface dams have been recognized as one of the most effective measures for preventing saltwater intrusion. However, it may result in large amounts of residual saltwater being trapped upstream of the dam and take years to decades to remove, which may limit the utilization of fresh groundwater in coastal areas. In this study, field-scale numerical simulations were used to investigate the mechanisms of residual saltwater removal from a typical stratified aquifer, where an intermediate low-permeability layer (LPL) exists between two high-permeability layers, under the effect of seasonal sea level fluctuations. The study quantifies and compares the time of residual saltwater removal (Tre) for constant sea level (CSL) and seasonally varying sea level (FSL) scenarios. The modelling results indicate that, in most cases, seasonal fluctuations in sea level facilitate the dilution of residual saltwater and thus accelerate residual saltwater removal compared to a static sea level scenario. However, accounting for seasonal sea level variations may increase the required critical dam height (the minimum dam height required to achieve complete residual saltwater removal). Sensitivity analyses show that Tre decreases with increasing height of subsurface dam (Hd) under CSL or weaker sea level fluctuation scenarios; however, when the magnitude of sea level fluctuation is large, Tre changes non-monotonically with Hd. Tre decreases with increasing distance between subsurface dam and ocean for both CSL and FSL scenarios. We also found that stratification model had a significant effect on Tre. The increase in LPL thickness for both CSL and FSL scenarios leads to a decrease in Tre and critical dam height. Tre generally shows a non-monotonically decreasing trend as LPL elevation increases. These quantitative analyses provide valuable insights into the design of subsurface dams in complex situations.


Asunto(s)
Agua Subterránea , Estaciones del Año , Agua Subterránea/química
10.
Sci Rep ; 14(1): 14536, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38977717

RESUMEN

Accelerated warming since the 1950s has caused dramatic change to ice shelves and outlet glaciers on the Antarctic Peninsula. Long observational records of ice loss in Antarctica are rare but essential to accurately inform mass balance estimates of glaciers. Here, we use aerial images from 1968 to reveal glacier configurations in the Larsen B region. We use structure-from-motion photogrammetry to construct high-resolution (3.2 m at best) elevation models covering up to 91% of Jorum, Crane, Mapple, Melville and Flask Glaciers. The historical elevation models provide glacier geometries decades before the Larsen B Ice Shelf collapse in 2002, allowing the determination of pre-collapse and post-collapse elevation differences. Results confirm that these five tributary glaciers of the former Larsen B Ice Shelf were relatively stable between 1968 and 2001. However, the net surface elevation differences over grounded ice between 1968 and 2021 equate to 35.3 ± 1.2 Gt of ice loss related to dynamic changes after the ice shelf removal. Archived imagery is an underutilised resource in Antarctica and was crucial here to observe glacier geometry in high-resolution decades before significant changes to ice dynamics.

11.
Heliyon ; 10(12): e33120, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-39021941

RESUMEN

This research investigates the impact of sea level rise (SLR) on the Indus Delta, a vital ecosystem increasingly vulnerable to climate change repercussions. The objective of this study is to comprehensively assess the flooded areas under various shared socioeconomic pathway (SSP) scenarios based on the Intergovernmental Panel on Climate Change's (IPCC) 6th Assessment Report. The study employs a GIS-based bathtub model, utilizing historical (1995-2014) and IPCC-projected (2020-2150) tide gauge data from Karachi, Kandla, and Okha stations to identify potential inundated areas threatened by coastal flooding. Additionally, it analyzes LANDSAT-derived multispectral images to identify coastal erosion hotspots and changes in the landscape. A supervised random forest classifier is used to classify major landforms and understand alterations in land cover. Furthermore, neural network-based cellular automata simulations are applied to predict future land cover for 2050, 2100, and 2150 at risk of inundation. The results indicate that under different SSP scenarios, the estimated inundated land area varies from 307.36 km2 (5 % confidence on SSP1-1.9) to 7150.8 km2 (95 % confidence on SSP5-8.5). By 2150, the region will lose over 550 km2 of agricultural land and 535 km2 of mangroves (mean SLR projection). This work emphasizes identifying sensitive land cover for SLR-induced coastal flooding. It might fuel future policy and modeling endeavors to reduce SLR uncertainty and build effective coastal inundation mitigation methods.

12.
Artículo en Inglés | MEDLINE | ID: mdl-38963788

RESUMEN

Purpose: Demodex infestation is a risk factor for several ocular surface diseases. However, the prevalence of ocular Demodex infection in the ultra-high altitude population is not clear. This study aimed to compare the prevalence and factors associated with Demodex in populations residing in ultra-high altitude region and sea level areas. Methods: Consecutive patients who visited Shigatse People's Hospital (> 4,000 m) and Shanghai Tongren Hospital (sea level) for eye complaints between January 2023 and January 2024 were included. Subjects were divided into ultra-high altitude and sea level groups. All subjects underwent eyelash epilation for ocular Demodex identification and counting. Demographic and lifestyle information was also collected. Results: A total of 517 subjects were eligible, including 255 subjects in the ultra-high-altitude group and 262 subjects in the sea level group. In the overall analysis, the prevalence of ocular Demodex infection was significantly different between the ultra-high-altitude and sea level groups (15.7% vs. 33.2%, P < 0.001). Multiple logistic regression showed that age, time spent outdoors, and makeup were associated with ocular Demodex infection in both groups. In addition, in the ultra-high-altitude group, people who wear sun hats outdoors were more likely to be infected with Demodex. Conclusion: The infection rate of ocular Demodex in the residents of ultra-high altitude area was significantly lower than that in the residents of sea level area, which may be related to lower ambient temperature, lower humidity, and higher solar radiation. Additionally, age, time spent outdoors, and makeup may be associated with ocular Demodex infection.

13.
Health Psychol Rev ; : 1-19, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083637

RESUMEN

This systematic review assesses the relationship between climate induced coastal hazards and psychological well-being of communities in the Asia-Pacific region. The review synthesises findings from 13 peer-reviewed articles published between 2007 and 2020, encompassing data from seven countries: Bangladesh, India, Indonesia, Philippines, Solomon Islands, Tuvalu, and Vietnam. Results reveals a robust negative association between exposure to coastal hazards and psychological outcomes, notably stress, depression, anxiety, and distress. Most of the studies (77%) corroborate negative impacts of coastal hazards on psychological health. Additionally, 69% of the reviewed articles suggest a correlation between coastal hazards and negative outcomes for community livelihoods and essential resources. The review highlights increased psychological vulnerability among marginalised subpopulations, such as economically disadvantaged communities, a trend supported by 92% of the examined articles. The findings indicates that factors such as environmental vulnerability, resource availability, community traits, and coping methods are important in determining whether a community can effectively handle coastal hazards or face increased psychological health risks. This research aligns with international health frameworks, including the World Health Organization's Health Emergency and Disaster Risk Management guidelines. However, a notable research gap emerges - the absence of studies that specifically explore psychological responses of communities to ongoing climate-related coastal hazards, such as sea-level rise. These findings emphasise an urgent need for targeted research to guide comprehensive, multidisciplinary policy interventions aimed at mitigating the psychological and socio-economic repercussions of climate-related coastal hazards.

14.
Sci Rep ; 14(1): 15881, 2024 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-38987576

RESUMEN

Populations consuming saline drinking water are at greater risk of high blood pressure and potentially other adverse health outcomes. We modelled data and used available datasets to identify countries of higher vulnerability to future saltwater intrusion associated with climate change in 2050 under Representative Concentration Pathways (RCP)4.5 and RCP8.5. We developed three vulnerability criteria to capture geographies with: (1) any coastal areas with projected inland saltwater intrusion of ≥ 1 km inland, (2) > 50% of the population in coastal secondary administrative areas with reliance on groundwater for drinking water, and 3) high national average sodium urinary excretion (i.e., > 3 g/day). We identified 41 nations across all continents (except Antarctica) with ≥ 1 km of inland saltwater intrusion by 2050. Seven low- and middle-income countries of higher vulnerability were all concentrated in South/Southeast Asia. Based on these initial findings, future research should study geological nuances at the local level in higher-risk areas and co-produce with local communities contextually appropriate solutions to secure equitable access to clean drinking water.


Asunto(s)
Cambio Climático , Agua Potable , Humanos , Agua Potable/análisis , Agua Subterránea/análisis , Abastecimiento de Agua , Hipertensión/epidemiología
15.
Mar Pollut Bull ; 205: 116551, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38878413

RESUMEN

The Caspian Sea, the world's largest enclosed water body, experiences significant transformations in its physico-chemical properties and a decline in bioresources due to extensive anthropogenic activities. These activities include the discharge of diverse pollutants and bio-physical alterations such as over-fishing, hunting, and physical alterations to rivers. While acute manifestations such as a fall in the Caspian water levels and wetland desiccation are more overt, the pervasive impact of human activities contributes to a likely irreversible decline in environmental quality that we aim to spotlight in this discussion in order to facilitate its restoration.


Asunto(s)
Monitoreo del Ambiente , Océanos y Mares , Conservación de los Recursos Naturales , Humedales
16.
Sci Total Environ ; 945: 173861, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38871323

RESUMEN

Coastal wetlands are key players in mitigating global climate change by sequestering soil organic matter. Soil organic matter consists of less stable particulate organic matter (POM) and more stable mineral-associated organic matter (MAOM). The distribution and drivers of MAOM and POM in coastal wetlands have received little attention, despite the processes and mechanisms differ from that in the upland soils. We explored the distribution of POM and MAOM, their contributions to SOM, and the controlling factors along a salinity gradient in an estuarine wetland. In the estuarine wetland, POM C and N were influenced by soil depth and vegetation type, whereas MAOM C and N were influenced only by vegetation type. In the estuarine wetland, SOM was predominantly in the form of MAOM (> 70 %) and increased with salinity (70 %-76 %), leading to long-term C sequestration. Both POM and MAOM increased with SOM, and the increase rate of POM was higher than that of MAOM. Aboveground plant biomass decreased with increasing salinity, resulted in a decrease in POM C (46 %-81 %) and N (52 %-82 %) pools. As the mineral amount and activity, and microbial biomass decreased, the MAOM C (2.5 %-64 %) and N pool (8.6 %-59 %) decreased with salinity. When evaluating POM, the most influential factors were microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Key parameters, including MBC, DOC, soil salinity, soil water content, aboveground plant biomass, mineral content and activity, and bulk density, were identified as influencing factors for both MAOM abundance. Soil water content not only directly controlled MAOM, but together with salinity also indirectly regulated POM and MAOM by controlling microbial biomass and aboveground plant biomass. Our findings have important implications for improving the accumulation and increased stability of soil organic matter in coastal wetlands, considering the global sea level rise and increased frequency of inundation.

17.
FEBS J ; 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38923815

RESUMEN

Antifreeze proteins (AFPs) are found in a variety of marine cold-water fishes where they prevent freezing by binding to nascent ice crystals. Their diversity (types I, II, III and antifreeze glycoproteins), as well as their scattered taxonomic distribution hint at their complex evolutionary history. In particular, type I AFPs appear to have arisen in response to the Late Cenozoic Ice Age that began ~ 34 million years ago via convergence in four different groups of fish that diverged from lineages lacking this AFP. The progenitor of the alanine-rich α-helical type I AFPs of sculpins has now been identified as lunapark, an integral membrane protein of the endoplasmic reticulum. Following gene duplication and loss of all but three of the 15 exons, the final exon, which encoded a glutamate- and glutamine-rich segment, was converted to an alanine-rich sequence by a combination of frameshifting and mutation. Subsequent gene duplications produced numerous isoforms falling into four distinct groups. The origin of the flounder type I AFP is quite different. Here, a small segment from the original antiviral protein gene was amplified and the rest of the coding sequence was lost, while the gene structure was largely retained. The independent origins of type I AFPs with up to 83% sequence identity in flounder and sculpin demonstrate strong convergent selection at the level of protein sequence for alanine-rich single alpha helices that bind to ice. Recent acquisition of these AFPs has allowed sculpins to occupy icy seawater niches with reduced competition and predation from other teleost species.

18.
Oxf J Leg Stud ; 44(2): 201-230, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38855121

RESUMEN

Small Island Developing States (SIDS) are uniquely threatened by rising sea levels. Not only does the retreat of their coastlines place them in danger of losing maritime territory; the concurrent possibility of their landmasses becoming either uninhabitable or completely submerged also threatens their very existence. According to one understanding of the law that governs the continuity and extinction of states, political communities that permanently lose 'effectiveness'-typically understood as sufficient governmental control of a relatively determinate territory with a permanent population-must lose their statehood as well. In this article, I provide three reconstructions of effectiveness, each of which rests upon a different normative rationale. My contention is that, regardless of which reconstruction one adopts, the continuity of submerged SIDS is eminently supportable, notwithstanding the arguments frequently made in favour of their formal extinction.

19.
Sci Rep ; 14(1): 14337, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38906913

RESUMEN

Global climate change in recent years has resulted in significant changes in sea levels at both global and local scales. Various oceanic and climatic factors play direct and indirect roles in influencing sea level changes, such as temperature, ocean heat, and Greenhouse gases (GHG) emissions. This study examined time series analysis models, specifically Autoregressive Moving Average (ARIMA) and Facebook's prophet, in forecasting the Global Mean Sea Level (GMSL). Additionally, Vector Autoregressive (VAR) model was utilized to investigate the influence of selected oceanic and climatic factors contributing to sea level rise, including ocean heat, air temperature, and GHG emissions. Moreover, the models were applied to regional sea level data from the Arabian Gulf, which experienced higher fluctuations compared to GMSL. Results showed the capability of autoregressive models in long-term forecasting, while the Prophet model excelled in capturing trends and patterns in the time series over extended periods of time.

20.
Sci Total Environ ; 947: 174289, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-38944311

RESUMEN

Coastal regions face climate-induced threats that have likely increased over the past four decades. In this work, we quantify the future climate impacts on hydroclimatic extremes in the risk-prone, 15-m-above-sea-level Eastern Shore of Virginia (ESVA) region, utilizing the Sixth International Coupled Model Intercomparison Project (CMIP6) Assessment Report 6 (AR6) and General Circulation Models (GCMs). We incorporate historical data on demographics and disasters, land use land cover (LULC), Landsat imagery, and sea level rise (SLR) to better understand and highlight the correlation between hydroclimatic extremes and societal components in this region. The hydrological model Soil and Water Assessment Tool (SWAT), Standardized Precipitation Index (SPI), Normalized Difference Water Index (NDWI), and Interquartile Range (IQR) method have been used to evaluate the intensity and frequency of projected climate extremes, in which SLR projections under different greenhouse gas emission pathways are temporally and spatially quantified. Our findings include (1) a trend towards wetter conditions is found with an increase in the number of flood events and up to an 8.9 % rise in the severity of flood peaks compared to the 2003-2020 period; (2) current coastal high-risk regions, identified using historical data of natural disasters, demographics, and LULC, are projected to be more susceptible to future climate impacts; and (3) low-lying coastal towns and regions are identified as currently vulnerable to coastal and SLR-induced flooding and are projected to become even more susceptible by 2100. This is the first effort that provides a valuable scientific basis for anticipated shifts in future climate patterns, essential for natural hazard prevention in ESVA. It highlights the need for authorities and decision-makers to plan and implement adaptive strategies and sustainable policies for the ESVA region and other coastal areas across the United States.

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