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SCN8A variants cause a spectrum of epilepsy phenotypes ranging from self‐limited infantile epilepsy (SeLIE) to developmental and epileptic encephalopathy. SeLIE is an infantile onset focal epilepsy, occurring in developmentally normal infants, which often resolves by 3 years. Our aim was to ascertain when epilepsy resolves in SCN8A‐SeLIE. We identified unpublished individuals with SCN8A‐SeLIE and performed detailed phenotyping. Literature was searched for published SCN8A‐SeLIE cases. Nine unpublished individuals from four families were identified (age at study = 3.5–66 years). Six had their last seizure after 3 years (range = 4–21 years); although drug‐responsive and despite multiple weaning attempts (1–5), five of six remain on antiseizure medications (carbamazepine, n = 3; lamotrigine, n = 2). We identified 29 published individuals with SCN8A‐SeLIE who had data on seizure progression. Of the 22 individuals aged at least 10 years, reported here or in the literature, nine of 22 (41%) had seizure offset prior to 3 years, five of 22 (23%) had seizure offset between 3 and 10 years, and eight of 22 (36%) had seizures after 10 years. Our data highlight that more than half of individuals with SCN8A‐SeLIE continue to have seizures into late childhood. In contrast to SeLIE due to other etiologies, many individuals have a more persistent, albeit drug‐responsive, form of epilepsy. [ABSTRACT FROM AUTHOR]

South Georgia is a heavily glaciated sub‐Antarctic island in the Southern Ocean. Cumberland Bay is the largest fjord on the island, split into two arms, each with a large marine‐terminating glacier at the head. Although these glaciers have shown markedly different retreat rates over the past century, the underlying drivers of such differential retreat are not yet understood. This study uses observations and a new high‐resolution oceanographic model to characterize oceanographic variability in Cumberland Bay and to explore its influence on glacier retreat. While observations indicate a strong seasonal cycle in temperature and salinity, they reveal no clear hydrographic differences that could explain the differential glacier retreat. Model simulations suggest the subglacial outflow plume dynamics and fjord circulation are sensitive to the bathymetry adjacent to the glacier, though this does not provide persuasive reasoning for the asymmetric glacier retreat. The addition of a postulated shallow inner sill in one fjord arm, however, significantly changes the water properties in the resultant inner basin by blocking the intrusion of colder, higher salinity waters at depth. This increase in temperature could significantly increase submarine melting, which is proposed as a possible contribution to the different rates of glacier retreat observed in the two fjord arms. This study represents the first detailed description of the oceanographic variability of a sub‐Antarctic island fjord, highlighting the sensitivity of fjord oceanography to bathymetry. Notably, in fjords systems where temperature decreases with depth, the presence of a shallow sill has the potential to accelerate glacier retreat. Plain Language Summary: Cumberland Bay, a fjord on the sub‐Antarctic island of South Georgia, is split into two arms, each with a large marine‐terminating glacier. One of these glaciers is retreating much faster than the other, possibly due to differences in oceanography between the arms. Here, we investigate how the oceanography in Cumberland Bay varies seasonally and with the seabed depth by using oceanographic data and numerical ocean simulations. We find that the properties of buoyant plumes, which arise from meltwater entering the ocean from beneath the glacier, are sensitive to the seabed depth near the glaciers, resulting in strong differences in ocean flow between the fjord arms. Assuming higher ocean temperatures increase glacier melting, we find that the presence of a near‐glacier shallow sill likely increases melting by blocking deeper, colder waters and trapping warmer surface waters close to the glacier. As a shallow sill is likely to be present near the rapidly retreating glacier only, this result offers a persuasive explanation for the observed glacier retreat. Understanding the variability in oceanography and glacier retreat is important as they directly impact the marine ecosystem at South Georgia by influencing the availability of nutrients for primary production and food availability for higher predators. Key Points: Observational data and a new high‐resolution model are combined to describe oceanographic variability in Cumberland Bay, South GeorgiaWe show that the properties of buoyancy‐driven outflow plumes are sensitive to bathymetry and drive spatial differences between fjord armsWe highlight that the presence of a postulated inner sill may be a key factor in the observed rapid glacier retreat [ABSTRACT FROM AUTHOR]

We use United Kingdom Earth System Model simulations from the Coupled Model Intercomparison Project 6 to analyze the Ross Gyre (RG) dynamics during the historical 1850–2014 period and under two contrasting future climate‐change scenarios. The modeled RG is relatively stable, with an extent and strength that agree with observations. The projections exhibit an eastward gyre expansion into the Amundsen‐Bellingshausen Seas that starts during the 2040s. The associated cyclonic ocean circulation enhances the onshore transport of warm Circumpolar Deep Water into the inner regional shelf, a regime change that increases the local subsurface shelf temperatures by up to 1.2°C and is independent of future forcing scenario. The RG expansion is generated by a regional ocean surface stress curl intensification associated with anthropogenic sea ice loss. If realised in reality, such a warming would strongly influence the future stability of the West Antarctic Ice Sheet. Plain Language Summary: We use a climate model to analyze ocean changes around West Antarctica. Our results reveal a human‐driven ocean warming that increases the continental shelf temperature in the Amundsen‐Bellingshausen Seas by more than 1°C in only ∼30 years. This rapid warming is caused by the expansion of the Ross Gyre (RG), a large oceanic circulation in the region. The West Antarctic Ice Sheet is losing mass, causing sea‐level rise, with the most rapid ice losses occurring in the Amundsen‐Bellingshausen Seas. Our results suggest that an expansion of the RG could provide a mechanism whereby melt rates increase far beyond the current range. This could have an important influence on the sea‐level rise caused by this region, with global impacts. Key Points: The UK Earth System Model produces a fairly realistic depiction of ocean conditions in West AntarcticaFuture projections suggest a rapid warming of the Amundsen Sea induced by a Ross Gyre (RG) expansion that is independent of forcing scenarioThe RG expansion is primarily caused by a surface stress curl intensification induced by anthropogenic trends in Antarctic sea ice [ABSTRACT FROM AUTHOR]

Aberrant joint loading contributes to the development of posttraumatic knee osteoarthritis (PTOA) following anterior cruciate ligament reconstruction (ACLR); yet little is known about the association between joint loading due to daily walking and cartilage health post‐ACLR. Accelerometer‐based measures of daily steps and cadence (i.e., rate of steps/min) provide information regarding daily walking in a real‐world setting. The purpose of this study was to determine the association between changes in serum cartilage oligomeric matrix protein (COMP; %∆COMP), a mechanosensitive biomarker that is associated with osteoarthritis progression, following a standardized walking protocol and daily walking in individuals with ACLR and uninjured controls. Daily walking was assessed over 7 days using an accelerometer worn on the right hip in 31 individuals with ACLR and 21 controls and quantified as mean steps/day and time spent in ≥100 steps/min. Serum COMP was measured before and following a 3000‐step walking protocol at a preferred speed. %∆COMP was calculated as a change in COMP relative to the prewalking value. Linear regressions were used to examine associations between daily walking and %∆COMP after adjusting for preferred speed. Fewer daily steps (ΔR2 = 0.18, p = 0.02) and fewer minutes spent in ≥100 steps/min (ΔR2 = 0.16, p = 0.03) were associated with greater %∆COMP following walking in individuals with ACLR; no statistically significant associations existed in controls (daily steps: ΔR2 = 0.03, p = 0.47; time ≥100 steps/min: ΔR2 < 0.01, p = 0.81). Clinical significance: Individuals with ACLR who engage in less daily walking undergo greater %ΔCOMP, which may represent greater cartilage degradation or turnover in response to walking. [ABSTRACT FROM AUTHOR]

While there is now strong evidence that many factors can shape dispersal, the mechanisms influencing connectivity patterns are species‐specific and remain largely unknown for many species with a high dispersal potential. The rock lobsters Jasus tristani and Jasus paulensis have a long pelagic larval duration (up to 20 months) and inhabit seamounts and islands in the southern Atlantic and Indian Oceans, respectively. We used a multidisciplinary approach to assess the genetic relationships between J. tristani and J. paulensis, investigate historic and contemporary gene flow, and inform fisheries management. Using 17,256 neutral single nucleotide polymorphisms we found low but significant genetic differentiation. We show that patterns of connectivity changed over time in accordance with climatic fluctuations. Historic migration estimates showed stronger connectivity from the Indian to the Atlantic Ocean (influenced by the Agulhas Leakage). In contrast, the individual‐based model coupled with contemporary migration estimates inferred from genetic data showed stronger inter‐ocean connectivity in the opposite direction from the Atlantic to the Indian Ocean driven by the Subtropical Front. We suggest that the J. tristani and J. paulensis historical distribution might have extended further north (when water temperatures were lower) resulting in larval dispersal between the ocean basis being more influenced by the Agulhas Leakage than the Subtropical Front. As water temperatures in the region increase in accordance with anthropogenic climate change, a southern shift in the distribution range of J. tristani and J. paulensis could further reduce larval transport from the Indian to the Atlantic Ocean, adding complexity to fisheries management. [ABSTRACT FROM AUTHOR]

Abstract: In the marine environment, understanding the biophysical mechanisms that drive variability in larval dispersal and population connectivity is essential for estimating the potential impacts of climate change on the resilience and genetic structure of populations. Species whose populations are small, isolated and discontinuous in distribution will differ fundamentally in their response and resilience to environmental stress, compared with species that are broadly distributed, abundant and frequently exchange conspecifics. Here, we use an individual‐based modelling approach, combined with a population genetics projection model, to consider the impacts of a warming climate on the population connectivity of two contrasting Antarctic fish species, Notothenia rossii and Champsocephalus gunnari. Focussing on the Scotia Sea region, sea surface temperatures are predicted to increase significantly by the end of the 21st century, resulting in reduced planktonic duration and increased egg and larval mortality. With shorter planktonic durations, the results of our study predict reduced dispersal of both species across the Scotia Sea, from Antarctic Peninsula sites to islands in the north and east, and increased dispersal among neighbouring sites, such as around the Antarctic Peninsula. Increased mortality modified the magnitude of population connectivity but had little effect on the overall patterns. Whilst the predicted changes in connectivity had little impact on the projected regional population genetic structure of N. rossii, which remained broadly genetically homogeneous within distances of ~1,500 km, the genetic isolation of C. gunnari populations in the northern Scotia Sea was predicted to increase with rising sea temperatures. Our study highlights the potential for increased isolation of island populations in a warming world, with implications for the resilience of populations and their ability to adapt to ongoing environmental change, a matter of high relevance to fisheries and ecosystem‐level management. [ABSTRACT FROM AUTHOR]

Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a 'seascape genetics' approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C. gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N. rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts. [ABSTRACT FROM AUTHOR]

This study seeks to quantify the influence of South Georgia's orography on regional surface winds. A typical case study characterized by large-scale westerly winds is analysed using a high-resolution setup (3.3 km) of the Weather Research and Forecasting (WRF) regional model. The simulation produces significant fine-scale spatial variability which is in agreement with satellite-derived winds. The model simulation indicates that these orography-driven wind disturbances are responsible for strong wind stress curl and enhanced heat flux over the shelf waters surrounding South Georgia. Such surface forcing is entirely absent from the reanalysis, highlighting the need to use high-resolution forcing in regional ocean model simulations. [ABSTRACT FROM AUTHOR]