Natural Scenarios Research Articles

Effects of Perceptual-motor Training on Collision Judgments with Peripheral Prism Expanded Vision.

Peripheral prisms (p-prisms) improve blind-side detection of hazards in hemianopia by shifting the image of the hazard into the intact visual field. Collision judgments can be made accurately after detection by using a gaze shift to fixate the hazard in the prism-free portion of the lens, but this is slow relative to normal peripheral vision. A prior study found that prism adaptation for visual direction did not occur with general wear. We developed a perceptual-motor training regimen that resulted in accurate pointing at p-prism targets after six 1-hour sessions. This study aimed to determine if improvements in pointing accuracy from perceptual-motor training generalized to collision judgments during simulated walking. Participants with hemianopia (n = 13) made collision judgments in virtual reality for a person appearing 0.4 to 13.5° from the walking path. Judgments were measured under fixed gaze, requiring collision judgments via the p-prism image only, and free gaze, representing a more natural scenario. Measurements were made without and with p-prisms immediately after fitting, after a 2-week acclimation, after training, and 3 months later. Controls (n = 13) did one visit without p-prisms. Controls had 100% detection and symmetrically distributed collision judgments for the central 33 and 36% of hazards under fixed gaze and free gaze, respectively. In hemianopia, the seeing side was not different from controls. Blind-side detection was reduced without p-prisms to 40% fixed gaze and 82% free gaze and improved with p-prisms to 99% fixed gaze and 97% free gaze (P < .001). When first worn, fixed-gaze prism side collisions were 63 versus 37% on the seeing side and 41 versus 39% for free gaze (P < .001). There was a small improvement for fixed gaze after the 2-week acclimation (53%, P < .001), but no improvements from training or an additional 3 months of use. P-prisms improved detection, but collision judgments were inaccurate when seen only via the p-prisms and did not improve with perceptual-motor training. Patients should continue to be advised to turn their head and eyes to fixate the hazard after detection.

Multi-Scenario Simulation of Land Use Change and Ecosystem Service Value in the Middle Reaches of Yangtze River Urban Agglomeration

The evolution of regional land use is a complex process under the combined effect of multiple factors, and it is important to understand this evolution process, as well as its characteristics and future trends, through land use change models in order to achieve scientific use of land space and optimize the regional development pattern. In this study, the PLUS model is used to simulate the land use in 2035 for the natural development scenario, the urban expansion scenario and the ecological protection scenario using the middle reaches of Yangtze River urban agglomeration (MRYRUA) as the study area, and then to calculate the ecosystem service values (ESV) and analyze the contribution of each driver to each land type and the spatial autocorrelation of the ESV at the grid scale. The results show that (1) the land use changes in the study area from 2015 to 2020 are mainly: the rapid expansion of construction land with an increase of 200,221 hm2 and an increase in arable land, specifically 85,982 hm2, and a decrease in all other land types. (2) The ESV of the study area was CNY 3,837,282 million and CNY 3,774,162 million from 2015 to 2020, respectively, with an general decreasing trend. (3) Three scenarios are simulated for the study area in 2035, and the ESVs under the natural development scenario, urban expansion scenario and ecological conservation scenario are CNY 3,618,062 million, CNY 3,609,707 million and CNY 3,625,662 million, respectively, which are all lower than those in 2020. (4) The global autocorrelation indices for 2020 and the three scenarios are 0.7126, 0.7104, 0.7144 and 0.7104, respectively, which are significantly positive. The simulation of MRYRUA land use and the comparative analysis of ESV provide some help in the strategic optimization of the spatial distribution pattern of land use in large regional urban agglomerations.

Modulation of the porcine intestinal microbiota in the course of Ascaris suum infection

BackgroundThe porcine roundworm Ascaris suum impairs feed conversion and weight gain, but its effects on intestinal microbiota remain largely unexplored.MethodsModulation of the intestinal microbiota was assessed in pigs that were infected once with 10,000 A. suum eggs and pigs that received a trickle infection (1000 eggs/day over 10 days), compared with a non-infected control group. Six pigs each were sacrificed per group at days 21, 35 and 49 post-infection (p.i.). Faecal samples taken weekly until slaughter and ingesta samples from different intestinal compartments were subjected to next-generation sequencing of the bacterial 16S rRNA gene.ResultsThe results revealed marked differences between the single- and the trickle-infected group. Single infection caused a remarkable but transient decrease in microbial diversity in the caecum, which was not observed in the trickle-infected group. However, an increase in short-chain fatty acid-producing genera in the caecum on day 21 p.i., which shifted to a decrease on day 35 p.i., was common to both groups, possibly related to changes in excretory–secretory products following the parasite’s final moult. Faecal microbial interaction networks were more similar between the single-infected and control group than the trickle-infected group. In addition, a lower degree of similarity over time indicated that A. suum trickle infection prevented microbiota stabilization.ConclusionsThese different patterns may have important implications regarding the comparability of experimental infections with natural scenarios characterized by continuous exposure, and should be confirmed by further studies.Graphical

Land Use Carbon Emission Measurement and Risk Zoning under the Background of the Carbon Peak: A Case Study of Shandong Province, China

Land use and cover change (LUCC) has a non-negligible impact on both carbon emissions and carbon sinks. Based on the analysis of land use dynamics in Shandong Province, this study simulates land use changes in Shandong Province in 2030 under the Natural Development Scenario (NDS) and Sustainable Development Scenario (SDS), classifies the risk level of carbon emissions in Shandong Province using the Land Use Carbon Emission (LUCE) risk indexes, and compares the differences between the risk level regions under NDS and SDS. This study shows that under the influence of LUCC, the carbon emissions in Shandong province increased significantly, from 90.5591 million tons in 2000 to 493.538 million tons in 2020, with urban land being the main source of carbon emissions, which increased from 90.0757 million tons in 2000 to 490.139 million tons in 2020. The main source of the increase in urban land was cropland. The LUCE was positively correlated with urban land area. The LUCE of SDS was 7.2423 million tons less than that of NDS. From 2000 to 2020, the risk areas of LUCE in Shandong province were mainly no-risk and mild-risk areas. The number of moderate-risk areas and high-risk areas of SDS was less than that of NDS. The rational organization of land use is important for Shandong Province to achieve low-carbon development.

Assessing the impacts of ecological governance on carbon storage in an urban coal mining subsidence area

Carbon storage, which is considered one of the important service functions of ecosystems, plays an irreplaceable role in maintaining the regional carbon balance and regulating the climate. Regional carbon storage is closely related to regional land use and land cover (LULC). With the development and expansion of coal resource-based cities, the construction areas of cities have started to overlap with underground coal resources. Coal mining leads to regional LULC changes, such as large-scale surface subsidence and subsidence waterlogging, and LULC has changed and consequently affected carbon storage in urban coal mining subsidence areas. This study analyses the change trend of carbon storage and clarifies the effect of ecological governance being implemented in the urban coal mining subsidence area. First, the LULC change map of the ecological governance scenario was obtained via remote sensing technology. Then, the natural evolution scenario from 2000 to 2021 was simulated using the hybrid cellular automata and Markov chain, also named the CA–Markov model. Finally, combined with the subsidence waterlogging in the urban subsidence area, the InVEST model was used to analyse the spatial–temporal variation characteristics of carbon storage. The analysis results showed that LULC and carbon storage in small-scale urban coal mining subsidence areas changed dramatically between 2000 and 2021 due to coal mining and ecological governance. The subsidence waterlogging area increased by 1033.83 ha, resulting in total carbon storage decreasing by 37,560.21 t. Subsidence waterlogging is the key influencing factor in the decrease in carbon storage. The forest area increased by 1270.83 ha, resulting in a total carbon storage increase of 216,531.04 t. Forest is the crucial increasing factor in carbon storage. The changes in carbon storage in the urban coal mining subsidence area can be classified as follows: obvious improvement area, basically unchanged area, and significantly degraded area. As opposed to the natural evolution scenario, the ecological governance scenario increased the coverage of the “obvious improvement area” by 818.46 ha in the urban coal mining subsidence area. Overall, this study illustrates that ecological governance can effectively improve carbon sequestration and is conducive to the healthy development of coal resource-based cities.

Temporal and Spatial Variation Characteristics of Carbon Storage in the Source Region of the Yellow River Based on InVEST and GeoSoS-FLUS Models and Its Response to Different Future Scenarios

Regional land use change is the main cause of carbon storage changes in ecosystems. Predicting the impact of future land use changes on carbon storage is of great significance for the sustainable development of carbon storage functions. In recent years, under the combined action of natural and human factors, the land use in the source region of the Yellow River has changed significantly, and its carbon storage function has also changed accordingly. This study combined InVEST and GeoSoS-FLUS models to evaluate land use change and its impact on carbon storage in the source region of the Yellow River from 2000 to 2020 and from 2020 to 2040 under different scenarios. The results showed that:① from 2000 to 2020, the carbon storage in the source region of the Yellow River showed an overall upward trend, with a total increase of 11.59×106 t. ② Over the past 20 years, the land use changes in the source region of the Yellow River included mainly the increase in the area of low-coverage grassland, construction land, and wetland and the decrease in the area of high-coverage grassland, medium-coverage grassland, and unused land, as well as the large-scale reduction of unused land and the reduction of grassland. The increase in the area of wetlands was the main reason for the increase in carbon storage. ③ Under the natural change scenario in 2040, the ecosystem carbon storage in the source region of the Yellow River was 871.34×106 t, an increase of 3.92×106 t compared with that in 2020. Under the ecological protection scenario, carbon storage increased significantly, with an increase of 13.53×106 t compared with that in 2020. The results of this study can provide a scientific reference for the decision-making of land use management and the sustainable development of carbon storage function in the source region of the Yellow River.

Increasing temperature extremes in New Zealand and their connection to synoptic circulation features

AbstractExtreme temperature events (ETEs) have evolved alongside the warming climate over most parts of the world. This study provides a statistical quantification of how human influences have changed the frequencies of extreme temperatures in New Zealand, depending on the synoptic weather types. We use the ensembles under pre‐industrial conditions (natural scenarios with no human‐induced changes) and present‐day conditions (anthropogenic scenarios) from the weather@home regional climate model. The ensemble simulations under these two scenarios are used to identify how human influences have impacted the frequency and intensity of extreme temperatures based on their connection to different large‐scale circulation patterns derived using self‐organizing maps (SOMs). Over New Zealand, an average two to three fold rise in frequencies of extremes occurs irrespective of seasons due to anthropogenic influence with a mean temperature increase close to 1°C. For some synoptic situations, the frequency of extremes are especially enhanced; in particular, for low‐pressure centres to the northeast of New Zealand where the frequency of occurrence of daily temperature extremes has increased by a factor of 7 between anthropogenic and natural ensembles for the winter season, though these synoptic patterns rarely occur. For low‐pressure centres to the northwest of New Zealand, we observe high temperatures frequently in both anthropogenic and natural ensembles which we expect is probably associated with warm air advection from the Tropics. The frequency of occurrence of high temperatures in these synoptic patterns has also increased by a factor of 2 between the natural and anthropogenic ensembles. For these synoptic states, the extremes are observed in the North Island and along the east coast of the country with the highest temperature along the Canterbury coast and Northland. The change between the natural and anthropogenic ensembles is largest on the west coast along the Southern Alps for all the synoptic circulation types.

Simulating the Coupling of Rural Settlement Expansion and Population Growth in Deqing, Zhejiang Province, Based on MCCA Modeling

Analyzing the relationship between rural settlements and rural population change under different policy scenarios is key in the sustainable development of China’s urban and rural areas. We proposed a framework that comprised the mixed land use structure simulation (MCCA) model and the human–land coupling development model to assess the spatiotemporal dynamic changes in rural settlements and its’ coupling relationship with the rural population in the economically developed region of Deqing, Zhejiang Province. The results showed that rural settlements and urban land increased by 14.36 and 29.07 km2, respectively, over the last 20 years. The expansion of some rural settlements and urban land occurred at the cost of cropland occupation. Rural settlements showed an expansion trend from 2000 to 2020, increasing from 42.69 km2 in 2000 to 57.05 km2 in 2020. In 2035, under the natural development scenario, the cropland protection scenario, and the rural development scenario, rural settlements are projected to show an expansion trend and Wukang and Leidian are the key regions with rural settlement expansion. The distance to Hangzhou, nighttime light data, distance to rivers, and precipitation are important factors influencing the expansion of rural settlements. The coupling relationship between rural settlements and the rural population developed in a coordinated manner from 2000 to 2020. For 2035, under different scenarios, the coupling relationship between rural settlements and the rural population showed different trends. In the rural development scenario, the highest number of towns with coordinated development between rural settlements and the rural population is in Deqing, predominantly with Type I coupling. Overall, an important recommendation from this study is that the sustainable development of regional land use can be promoted by controlling the occupation of cropland for urban and rural construction, balancing rural settlement expansion and rural population growth, and formulating land use policies that are more suitable for rural development.

A Systemic Approach for Natural Language Scenario Elicitation of Security Requirements

Security analysts rely on scenarios to assess vulnerabilities, project attacks, and decide on security requirements that mitigate the threat. However, eliciting natural language scenarios from stakeholders can be an ad-hoc process and subject to ambiguity and incompleteness. In this article, we examine systematic scenario elicitation by introducing a method based on user stories that uses a simplified process model of iterative scenario refinement. The process consists of three steps: 1) eliciting an interaction statement that describes a critical action performed by a user or system process; 2) eliciting one or more descriptive statements about a technology that enables the interaction; and 3) refinement of the technology into technical variants that correspond to design alternatives. We empirically evaluated our method by implementing our prototype in a user study that collects 30 security scenarios from participants. Based on our analysis, our proposed method is shown effective. Participants had a 100 percent task completion rate with 57 percent of participants achieving complete task-success, and the remaining 43 percent of participants achieving partial task-success. We also show the effect of security domain knowledge, and the benefit of using structure when collecting security requirements in natural language text. Finally, we present lessons learned and future research directions.

The Effects of Land-Use and Climatic Changes on the Hydrological Environment in the Qinling Mountains of Shaanxi Province

Under the dual influence of climate change and land-use change, different protection policies in Qinling Mountains lead to different hydrological responses. On the basis of land-use and climatic changes in the Qinling Mountains of Shaanxi province, we constructed a response model among land use, climate, and runoff in the Qinling Mountains through the Soil and Water Assessment Tool (SWAT) model. The Patch-generating Land Use Simulation (PLUS) model was used to predict and simulate land-use types of the Qinling Mountains in 2025 and 2030. On the basis of the current ecological protection policy in China, two scenarios of land use were set up to find the best method for forestland protection. The results show the following. The SWAT model is applicable to the Weihe River and Hanjiang River basins of the Qinling Mountains, the simulation results were verified, and the Nash coefficient was above 0.6. Under future climate change and land-use patterns, runoff in the Qinling Mountains watershed shows an upward trend, and the runoff in the Hanjiang River basin increased by more than that in the Weihe River basin, with change rates of 47.471 and 33.356 m3/10a, respectively. According to the future trend of the two different scenarios, the increase degree of runoff in the natural scenario of Weihe River basin was 16.567 m3/10a higher than that in the woodland scenario, and the increase degree of runoff in the Hanjiang River basin was 17.692 m3/10a higher than that in the woodland scenario. Therefore, blindly increasing the forestland area in Qinling Mountains cannot achieve a better hydrological effect.

A comparative analysis of the cumulative greenhouse gas emissions and financial viability of residential heating systems located in New York state

AbstractAchieving the stringent climate goals established by New York State will require significant emissions reductions across the agriculture, commercial and residential, electricity, industry and transportation sectors. This study analyzed the residential heating sector and quantified the environmental and financial impacts of four different residential heating pathways for buildings located in New York State. A conventional ultra‐low sulfur diesel pathway served as the baseline scenario against which three low‐carbon alternative pathways were compared: (1) a ‘bioheat’ scenario in which biomass‐based diesel is blended with heating oil; (2) a natural gas scenario; and (3) an electric scenario (air‐source heat pump). The low‐carbon alternative heating pathways incorporate the social cost of carbon as an internalized financial benefit from the conventional ultra‐low sulfur diesel baseline scenario. The bioheat pathway yielded the highest net present value (NPV) at $3 684 513 and the electric (air‐source heat pump) pathway had a NPV of $3 618 229. The electric and bioheat scenarios yielded the lowest and second lowest total cumulative emissions at 28545 Mt CO2e and 51 438 Mt CO2e, respectively. This study also incorporated a comprehensive sensitivity analysis to depict the impact of: NPV discount rates, fuel costs, carbon intensity values, system installation costs and social cost of carbon values. The study provides policymakers, researchers and other interested stakeholders with a comparison of the environmental and financial impacts of diverse residential heating systems. © 2022 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Fusarium Crown Rot Reduces Water Use and Causes Yield Penalties in Wheat under Adequate and above Average Water Availability

The cereal disease Fusarium crown rot (FCR), caused by the fungal pathogen Fusarium pseudograminearum, is a worldwide major constraint to winter cereal production but especially in Australia’s northern grain’s region (NGR) of NSW and Queensland. Conventionally, FCR induced yield penalties are associated with semi-arid water-limited conditions during flowering and grain-filling. In this study, yield penalties associated with FCR infection were found to be significant under both adequate and above average water conditions which has implication for global wheat production in more favorable environments. This research was conducted to understand the impact of FCR on water availability, yield and grain quality in high protein bread and durum wheat varieties in controlled environment and replicated field experiments across three locations in the NGR over a two-year period. Under controlled conditions, FCR infection significantly decreased water use by 7.5% with an associated yield reduction of 9.5% irrespective of water treatment. Above average rainfall was experienced across all field experimental sites in both 2020 and 2021 growing seasons. The field studies demonstrated a decrease in water use of upwards of 23% at some sites and significant yield penalties across all cultivars of up to 18.4% in natural rainfed scenarios to still 13.2% with further supplementary irrigation.

Optimization of the Ecological Network Structure Based on Scenario Simulation and Trade-Offs/Synergies among Ecosystem Services in Nanping

The optimization of the ecological network structure in Nanping can provide a scientific reference for guaranteeing ecological safety in Southeast China. This study estimated ecosystem services in Nanping with the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model based on land-use data from 2020 to 2025 simulated with the CLUE-S model under the natural development scenario and ecological protection scenario and then explored their trade-offs and synergies. The ecological network structure was, thereafter, optimized in terms of the eco-matrix, eco-corridors and nodes based on simulated land use and ecosystem services. The results suggested that the average habitat quality and total soil retention increased, while the average degradation index and total water yield decreased under the ecological protection scenario, indicating that the ecological environment quality tended to be improved. In addition, soil retention had significant synergies with habitat quality and water yield, and habitat quality had significant trade-offs with ecological degradation and water yield on the regional scale under two scenarios, while ecological degradation also showed significant trade-offs with soil retention and water yield. In addition, the results suggested that 11 additional ecological sources could be added, and the number of eco-corridors increased from 15 to 136; a total of 1019 ecological break points were restored, and 1481 stepping stone patches were deployed, which jointly made network circuitry, edge/node ratio and network connectivity reach 0.45, 1.86 and 0.64, respectively, indicating that optimization could effectively improve the structure and connectivity of the ecological network. These findings can provide a theoretical basis for improving the ecological network structure and ecological service functions in Nanping and other regions.

Prediction of the Spatial Pattern of Carbon Emissions Based on Simulation of Land Use Change under Different Scenarios

Land use is an important factor in the change of carbon emissions, and predicting the spatial pattern of carbon emissions under different land use scenarios is of great significance to respond to the “double carbon” target of China. Based on the land use data of Nanjing city, Jiangsu Province, China in 2010, 2015 and 2020, this study used the Conversion of Land Use and its Effects at Small regional extent (CLUE-S) model to simulate the land use change pattern in 2030 under multiple scenarios, and predicted the carbon emissions of each subzone based on the simulation results. It also provides a carbon balance zoning from an economic and ecological point of view and proposes strategies tailored to each district. The results show that: (1) in 2030, under the ecological conservation scenario, ecological land all shows different degrees of increase, while under the cultivated land conservation scenario, construction land only increased by 1.47%. This indicates that the ecological and cultivated land protection perspectives can effectively curb the expansion of construction land. (2) The growth rate of carbon emissions in Nanjing from 2010–2030 decreased from 16.65–3.7%. This indicates that carbon emissions continue to rise, but the trend of growth is slowing down. (3) The spatial carbon emissions in Nanjing show an overall higher level in the north and lower in the center; the large expansion of building land and the concentration of industrial industries are the main reasons for the large increase in carbon emissions. Under the ecological protection scenario, the carbon emissions of Lishui, Pukou and Qixia districts were 11.05 × 104 t, 19.437 × 104 t and 10.211 × 104 t lower than those under the natural growth scenario, mainly because these three districts have more ecological land and the ecological protection effect is more significant. Under the cultivated land conservation scenario, the growth rate of carbon emissions slows down significantly. This indicates that the future structure of carbon emissions in Nanjing will vary significantly, and that ecological protection and arable land conservation play an important role in reducing carbon emissions. This study shows that it is difficult to reduce emissions in a concerted manner. Therefore, for different districts, differentiated land use optimization measures should be developed according to local conditions, and ecological protection and cultivated land protection scenarios should both be taken into account.

Assessing natural global catastrophic risks.

The risk of global catastrophe from natural sources may be significantly larger than previous analyses have found. In the study of global catastrophic risk (GCR), one line of thinking posits that deep human history renders natural GCRs insignificant. Essentially, the fact that natural hazards did not cause human extinction at any previous time makes it unlikely that they would do so now. This paper finds flaws in this argument, refines the theory of natural GCR, analyzes the space of natural GCRs, and presents implications for decision-making and research. The paper analyzes natural climate change, natural pandemics, near-Earth objects (asteroids, comets, and meteors), space weather (coronal mass ejections, solar flares, and solar particle events), stellar explosions (gamma-ray bursts and supernovae), and volcanic eruptions. Almost all natural GCR scenarios involve important interactions between the natural hazard and human civilization. Several natural GCR scenarios may have high ongoing probability. Deep human history provides little information about the resilience of modern global civilization to natural global catastrophes. The natural GCRs should not be dismissed on grounds of deep human history. Work on natural GCRs should account for their important human dimensions. A case can even be made for abandoning the distinction between natural and anthropogenic GCR.

Dynamic characteristics and responses of ecosystem services under land use/land cover change scenarios in the Huangshui River Basin, China

High-intensity human activities have changed land use/land cover (LULC) patterns in the Huangshui River Basin (HRB), which has brought significant challenges to ecosystems sustainable development. Discerning ecosystem service dynamic characteristics and responses under different land use/cover change (LUCC) scenarios are necessary to increase the public willingness to pay for the ecosystem and guide the decision-making process. We examined LULC spatiotemporal dynamics in the HRB from 2000 to 2020 and coupled Markov-chain, multi-objective programming (MOP), and patch-generating land use simulation (PLUS) models to optimize and simulate LULC spatial pattern for five scenarios: natural development scenario (NDs), city expansion scenario (CEs), ecological protection scenario (EPs), economic development scenario (EDs), ecological and economic balance scenario (EEBs). Given regional differences, a spatially modified ecosystem service value (ESV) assessment model was proposed to evaluate ESV. Factors driving ESV spatial stratified heterogeneity were identified using geographic detectors. Ecosystem service value sensitivity in response to LUCC was discriminated against using the elasticity model. The study area was dominated by 56.86–60.40 % grassland and 33.11–36.27 % cropland. Grassland and cropland area decreased by 579.75 km2 and 423.87 km2 over the period 2000–2020, while the other areas such as forestland, water area, construction land, and barren land increased by 289.81 km2, 140.77 km2, 489.10 km2, and 83.96 km2, respectively. Land conversion mainly occurred among grassland, cropland, and construction land. Total ESV was 39,665 million yuan in 2020, an increase of 2.25 % compared to 2000. Total ESV of NDs, EPs, EDs, and EEBs increased by 0.34 %, 1.04 %, 2.01 %, and 7.78 %, respectively compared to 2020, while that of CEs decreased by 0.17 %. ESV sensitivity coefficient response to LUCC was 0.43 during 2010–2020, indicating that LULC conversion of 1 % would result in average changes of 0.43 % in ESV. Ecosystem services response to LUCC was not very marked in the HRB. Elevation was the dominant driver of LULC and ESV stratified spatial heterogeneity in the HRB. The effects of elevation on LUCC and ESV should receive more attention in management. Multi-objective optimization and multi-scenario analysis effectively guided land-use planning and decision-making involved in ecosystem uncertainty, complexity, and interaction. The EPs and EEBs may be more suitable for future HRB development.

Urban land use change simulation and spatial responses of ecosystem service value under multiple scenarios: A case study of Wuhan, China

Simulation of changes in ecosystem service value (ESV) caused by land use change in Wuhan under multiple scenarios is of great significance for ensuring urban ecological security and enhancing regional ecosystem service values. The city of Wuhan was selected as the study area, and the changes in land use and ESV in Wuhan over the past 31 years were analyzed and calculated based on five-phase remote sensing images and statistical yearbooks for 1990, 1998, 2006, 2014 and 2021. On this basis, the CA-Markov model and the multi objective planning (MOP) model were used to simulate the land use change in the study area in 2040 under four scenarios (natural development scenario, cultivated land protection scenario, ecological protection scenario and urban development scenario), and the total ESV was estimated under each scenario. The total value of ecosystem services was estimated under each scenario, and grid tools were applied to visualize the spatial distribution and degree of aggregation of ecosystem services. The results show that: (1) The most obvious feature of land use change in Wuhan from 1990 to 2021 is the sharp reduction in arable land area and the rapid expansion of build-up land area. Over the past 31 years, the arable land area decreased by 78322.4 hm2, and the build-up land area increased by 52559.28 hm2. (2) From 1990 to 2021, Wuhan’s total ESV at the five timepoints (1990, 1998, 2006, 2014, 2021) was 74.554 billion yuan, 71.512 billion yuan, 69.632 billion yuan, 73.433 billion yuan and 68.548 billion yuan, respectively. Overall, there has been a downward trend in volatility. (3) Under the four scenarios, the ESV in 2040 is projected to be 72.777 billion yuan, 70.969 billion yuan, 74.097 billion yuan or 70.620 billion yuan, respectively. Among them, the ecological protection scenario is the optimal simulation choice. (4) The cold and hot spots of ESV show an aggregated distribution over a large area, with the hot spots mainly concentrated in the central and southeastern parts of Wuhan and the cold spots mainly located in the northeastern and northwestern portions of Wuhan. Simulating the future land use change trends in Wuhan and exploring the responses of ecosystem service values under various scenarios are conducive to the construction of a new pattern of urban land space development and protection and can provide a scientific basis and a reference for decision-making for comprehensively promoting the sustainable development of Wuhan and other metropolitan areas in China in the future.

Selection of representative natural hazard scenarios for engineering systems

AbstractRepresentative hazard scenarios are essential for many tasks in risk management, such as preparedness and emergency response planning. However, criteria and methods for systematically selecting such scenarios for natural hazards are lacking. From a risk perspective, such scenarios should be selected considering the losses they incur. Hence, we propose to define a scenario that is representative for a certain degree of loss, for example, the 100‐year loss, as the most likely one among all possible scenarios leading to this loss. Taking basis in a generic model of natural hazards and their impact on engineering systems, we formally introduce the representative scenarios. We then develop algorithms that enable an efficient evaluation of these scenarios. The method and algorithms are demonstrated on a hypothetical example considering a spatially distributed infrastructure system subjected to earthquakes.

Prospects for Heavy Neutral SUSY HIGGS Scalars in the hMSSM and Natural SUSY at LHC Upgrades

We examine production and decay of heavy neutral SUSY Higgs bosons pp→H,A→ττ¯ within the hMSSM and compare against a perhaps more plausible natural supersymmetry scenario dubbed mh125(nat) which allows for a natural explanation for mweak≃mW,Z,h∼100 GeV while maintaining mh≃125 GeV. We evaluate signal against various Standard Model backgrounds from γ,Z→ττ¯, tt¯ and vector boson pair production VV. We combine the transverse mass method for back-to-back (BtB) taus along with the ditau mass peak mττ method for acollinear taus as our signal channels. This technique ultimately gives a boost to the signal significance over the standard technique of using just the BtB signal channel. We evaluate both the 95% CL exclusion and 5σ discovery reach in the mA vs. tanβ plane for present LHC with 139 fb−1, Run 3 with 300 fb−1 and high luminosity LHC (HL-LHC) with 3000 fb−1 of integrated luminosity. For tanβ=10, the exclusion limits range up to mA∼1, 1.1 and 1.4 TeV, respectively. These may be compared to the range of mA values gleaned from a statistical analysis of the string landscape wherein mA can range up to ∼8 TeV.

S400 A Cost Utility Model Supports Changes in Post-Treatment Surveillance Associated With the 2022 American College of Gastroenterology Guidelines

Introduction: Radiofrequency ablation is a safe and effective treatment for neoplastic Barrett’s esophagus (BE), but surveillance after endoscopic eradication has only been studied observationally without any studies of this disease’s natural history. Recent natural history modeling work has allowed qualified estimation of a natural history scenario. We sought to apply our multi-state model of post-ablation natural history to study the cost effectiveness of surveillance after endoscopic eradication of neoplastic BE. Methods: We constructed a microsimulation cost-utility model of endoscopic surveillance after complete eradication of intestinal metaplasia (CEIM) with intervals as recommended by the 2022 American College of Gastroenterology BE guideline. A cohort of participants were modeled after the United States (US) Radiofrequency Ablation cohort in terms of demographics, worst prior histologic grade, and pre-treatment BE segment length. Transition probabilities for the natural history were estimates from published multi-state models. The model was Markov generalized to allow differing rates of progression based on BE characteristics as covariates to the multi-state model and for other-cause mortality to depend on age. There were states for: no recurrence, recurrence with various histologic grades, ablative re-treatment, endoscopic mucosal resection, invasive adenocarcinoma, and death. We considered a willingness-to-pay threshold of 100,000 2017 US dollars ($) per quality-adjusted life year (QALY). Model parameters and their sources are described in the Table. Results: In the base case scenario of the model, surveillance and re-treatment decreased progression to invasive esophageal adenocarcinoma at ten years by 1.2% in LGD and 13.0% in HGD/IMC (Figure). Compared to the natural history scenario, the incremental cost effectiveness ratio for surveillance at ten years was $79,125 for LGD and $10,952 for HGD/IMC. Conclusion: In the base case scenario of this cost-utility model, newly recommended surveillance intervals were highly cost effective for HGD/IMC and approached the margins of cost-effectiveness for LGD in a microsimulation cost-utility model. This supports the new guideline recommendation to decrease the frequency of post-treatment surveillance of HGD/IMC and LGD. While development of the model requires probabilistic sensitivity analysis and calibration, the model has the potential to inform the health economics of clinical processes after CEIM. Table 1. - Microsimulation model parameters in the base case scenario and their sources. Model variable Base case value Reference/details Structural model assumptions Model cycle length 3 months Model time horizon 10 years Model starting year 2017 For other-cause mortality and inflation adjustment Other cause mortality Population 2020 Social Security actuarial cohort life Tables Time for resection 1 cycle Resection for all recurrent HGD or IMC Resection success rate 100% Simplifying assumption Time for ablation 1 cycle Repeated until successful Discounting of costs/utilities 3% Per year Probabilities per cycle from the literature Death from invasive adenocarcinoma 7.63% SEER 5-Year Relative Survival Rates 2012-2018* Complete eradication of intestinal metaplasia after recurrence 57.7% Guthikonda et al., The American Journal of Gastroenterology, 2017 Cancer progression from recurrence 0.1625% Guthikonda et al., The American Journal of Gastroenterology, 2017 Utilities per cycle from the literature Surveillance after CEIM 97% Boger et al., Alimentary Pharmacology and Therapeutics, 2010 Retreatment endoscopy 94% Boger et al., Alimentary Pharmacology and Therapeutics, 2010 Esophageal adenocarcinoma 96% Boger et al., Alimentary Pharmacology and Therapeutics, 2010 Costs per cycle from the literature Surveillance endoscopy $1,019 Inadomi et al., Gastroenterology, 2009† Cost of cancer care $13,532 Inadomi et al., Gastroenterology, 2009† Cost of ablation re-treatment $4,317 Inadomi et al., Gastroenterology, 2009† Assumed half cost of initial treatment Cost of resection re-treatment $934 Filby et al., Journal of Comparative Effectiveness Research, 2017 ** *Assumes cumulative incidence = 1 – e^(-incidence x time).†Assuming 17.7% inflation.**Assumes 133% exchange rate with the British Pound. Figure 1.: Model state occupancy by months after complete eradication of intestinal metaplasia.