Assessing Torque Transfer in Conduction System Pacing: Development and Evaluation of an Ex Vivo Model.

BACKGROUND: Conduction system pacing (CSP) faces challenges in achieving reliable and safe deployments. Complex interactions between tissue and lead tip can result in endocardial entanglement, a drill effect that prevents penetration. No verified ex vivo model exists to quantitatively assess this relationship. OBJECTIVES: The purpose of this study was to quantitatively characterize CSP lead tip to tissue responses for 4 commonly used leads. METHODS: CSP leads (from Medtronic, Biotronik, Boston Scientific, and Abbott) were examined for helix rotation efficiency in ex vivo ovine right ventricular septa. A custom jig was utilized for rotation measurements. Fifteen turns were executed, documenting tissue-interface changes every 90° using high-resolution photography. Response curves (input rotation vs helix rotation) were evaluated using piecewise linear regression, with a focus on output vs input response slopes and torque breakpoint events. RESULTS: We analyzed 3,840 quarter-turn CSP insertions with 4 different lead types. Helix rotations were consistently less than input: Abbott Tendril = 0.21:1, Medtronic 3830 = 0.21:1, Biotronik Solia = 0.47:1, and Boston Scientific Ingevity = 0.56:1. Torque breakpoint events were observed on average 7.22 times per insertion (95% CI: 6.08-8.35; P = NS) across all leads. In 57.8% of insertions (37 of 64), uncontrolled torque breakpoint events occurred, signaling unexpected excess helix rotations. CONCLUSIONS: Using a robust ex vivo model, we revealed a muted helix rotation response compared with input turns on the lead, and frequent torque change events during insertion. This is critical for CSP implanters, emphasizing the potential for unexpected torque breakpoint events, and suggesting the need for novel lead designs or deployment methods to enhance CSP efficiency and safety.

Systematic conservation planning for Antarctic research stations.

The small ice-free areas of Antarctica are essential locations for both biodiversity and scientific research but are subject to considerable and expanding human impacts, resulting primarily from station-based research and support activities, and local tourism. Awareness by operators of the need to conserve natural values in and around station and visitor site footprints exists, but the cumulative nature of impacts often results in reactive rather than proactive management. With human activity spread across many isolated pockets of ice-free ground, the pathway to the greatest reduction of human impacts within this natural reserve is through better management of these areas, which are impacted the most. Using a case study of Australia's Casey Station, we found significant natural values persist within the immediate proximity (<10 m) of long-term station infrastructure, but encroachment by physical disturbance results in ongoing pressures. Active planning to better conserve such values would provide a direct opportunity to enhance protection of Antarctica's environment. Here we introduce an approach to systematic conservation planning, tailored to Antarctic research stations, to help managers improve the conservation of values surrounding their activity locations. Use of this approach provides a potential mechanism to balance the need for scientific access to the continent with international obligations to protect its environment. It may also facilitate the development of subordinate conservation tools, including management plans and natural capital accounting. By proactively minimising and containing their station footprints, national programs can also independently demonstrate their commitment to protecting Antarctica's environment.

A continent-wide detailed geological map dataset of Antarctica.

A dataset to describe exposed bedrock and surficial geology of Antarctica has been constructed by the GeoMAP Action Group of the Scientific Committee on Antarctic Research (SCAR) and GNS Science. Our group captured existing geological map data into a geographic information system (GIS), refined its spatial reliability, harmonised classification, and improved representation of glacial sequences and geomorphology, thereby creating a comprehensive and coherent representation of Antarctic geology. A total of 99,080 polygons were unified for depicting geology at 1:250,000 scale, but locally there are some areas with higher spatial resolution. Geological unit definition is based on a mixed chronostratigraphic- and lithostratigraphic-based classification. Description of rock and moraine polygons employs the international Geoscience Markup Language (GeoSciML) data protocols to provide attribute-rich and queryable information, including bibliographic links to 589 source maps and scientific literature. GeoMAP is the first detailed geological map dataset covering all of Antarctica. It depicts 'known geology' of rock exposures rather than 'interpreted' sub-ice features and is suitable for continent-wide perspectives and cross-discipline interrogation.

The influence of the COVID pandemic on the epidemiology of Achilles tendon ruptures in east Shropshire, United Kingdom.

OBJECTIVES: Management strategies of the COVID pandemic included isolation to prevent transmission. This study aimed to determine if the pandemic of 2020 influenced the epidemiology of Achilles tendon rupture (ATR). METHODS: The demographics of presentations from the local population to Princess Royal Hospital, Shrewsbury & Telford Hospital NHS Trust hospital, Shropshire, United Kingdom, with an ATR were analysed and compared together with the season, month, and year of the injury. RESULTS: From 2009 to 2019, there was no significant change in the incidence of ATR over time with a mean (SD) incidence of 13.3 per 100,000. In 2020, there was a decrease in injuries with an incidence of 8.4 per 100,000, with an increase in 2021 to 22.4 per 100,000. In 2021, there was an increase in injuries from March with numbers maintained until October. The most common activity of ATR was team sport (36.2%), followed by the activities of daily living (28.9%), other physical activities (21.0%), and racket sports (13.9%). In 2020, there was the lowest number of injuries sustained in team and racket sports; however, in 2021, they accounted for over half of injuries. CONCLUSIONS: There were significantly more patients sustaining ATR in 2021, the year after the COVID pandemic and mandatory isolation. This was considered to be related to altered activity and team and racket sports during 2020. LEVELS OF EVIDENCE: IV case series.

Forecasting the future of life in Antarctica.

Antarctic ecosystems are under increasing anthropogenic pressure, but efforts to predict the responses of Antarctic biodiversity to environmental change are hindered by considerable data challenges. Here, we illustrate how novel data capture technologies provide exciting opportunities to sample Antarctic biodiversity at wider spatiotemporal scales. Data integration frameworks, such as point process and hierarchical models, can mitigate weaknesses in individual data sets, improving confidence in their predictions. Increasing process knowledge in models is imperative to achieving improved forecasts of Antarctic biodiversity, which can be attained for data-limited species using hybrid modelling frameworks. Leveraging these state-of-the-art tools will help to overcome many of the data scarcity challenges presented by the remoteness of Antarctica, enabling more robust forecasts both near- and long-term.

Antarctica's wilderness fails to capture continent's biodiversity.

Recent assessments of Earth's dwindling wilderness have emphasized that Antarctica is a crucial wilderness in need of protection1,2. Yet human impacts on the continent are widespread3-5, the extent of its wilderness unquantified2 and the importance thereof for biodiversity conservation unknown. Here we assemble a comprehensive record of human activity (approximately 2.7 million records, spanning 200 years) and use it to quantify the extent of Antarctica's wilderness and its representation of biodiversity. We show that 99.6% of the continent's area can still be considered wilderness, but this area captures few biodiversity features. Pristine areas, free from human interference, cover a much smaller area (less than 32% of Antarctica) and are declining as human activity escalates6. Urgent expansion of Antarctica's network of specially protected areas7 can both reverse this trend and secure the continent's biodiversity8-10.

Estimating impacts of climate change policy on land use: an agent-based modelling approach.

Agriculture is important to New Zealand's economy. Like other primary producers, New Zealand strives to increase agricultural output while maintaining environmental integrity. Utilising modelling to explore the economic, environmental and land use impacts of policy is critical to understand the likely effects on the sector. Key deficiencies within existing land use and land cover change models are the lack of heterogeneity in farmers and their behaviour, the role that social networks play in information transfer, and the abstraction of the global and regional economic aspects within local-scale approaches. To resolve these issues we developed the Agent-based Rural Land Use New Zealand model. The model utilises a partial equilibrium economic model and an agent-based decision-making framework to explore how the cumulative effects of individual farmer's decisions affect farm conversion and the resulting land use at a catchment scale. The model is intended to assist in the development of policy to shape agricultural land use intensification in New Zealand. We illustrate the model, by modelling the impact of a greenhouse gas price on farm-level land use, net revenue, and environmental indicators such as nutrient losses and soil erosion for key enterprises in the Hurunui and Waiau catchments of North Canterbury in New Zealand. Key results from the model show that farm net revenue is estimated to increase over time regardless of the greenhouse gas price. Net greenhouse gas emissions are estimated to decline over time, even under a no GHG price baseline, due to an expansion of forestry on low productivity land. Higher GHG prices provide a greater net reduction of emissions. While social and geographic network effects have minimal impact on net revenue and environmental outputs for the catchment, they do have an effect on the spatial arrangement of land use and in particular the clustering of enterprises.

Modelling the impacts of an invasive species across landscapes: a step-wise approach.

We estimate the extent of ecological impacts of the invasive Asian paper wasp across different landscapes in New Zealand. We used: (i) a baseline distribution layer (modelled via MaxEnt); (ii) Asian paper wasp nest density (from >460 field plots, related to their preferences for specific land cover categories); and (iii) and their foraging intensity (rates of foraging success, and the time available to forage on a seasonal basis). Using geographic information systems this information is combined and modelled across different landscapes in New Zealand in a step-wise selection process. The highest densities of Asian paper wasps were in herbaceous saline vegetation, followed closely by built-up areas, and then scrub and shrubland. Nest densities of 34 per ha, and occupancy rates of 0.27 were recorded for herbaceous saline vegetation habitats. However, the extent of impacts of the Asian paper wasp remains relatively restricted because of narrow climate tolerances and spatial restriction of preferred habitats. A step-wise process based on geographic information systems and species distribution models, in combination with factors such as distribution, density, and predation, create a useful tool that allows the extent of impacts of invasive species to be assessed across large spatial scales. These models will be useful for conservation managers as they provide easy visual interpretation of results, and can help prioritise where direct conservation action or control of the invader are required.