Differential gene expression represents a fundamental cause and manifestation of phenotypic plasticity. Adaptive phenotypic plasticity in gene expression as a trait evolves when alleles that mediate gene regulation serve to increase organismal fitness by improving the alignment of variation in gene expression with variation in circumstances. Among the diverse circumstances that a gene encounters are distinct cell types, developmental stages and sexes, as well as an organism's extrinsic ecological environments. Consequently, adaptive phenotypic plasticity provides a common framework to consider diverse evolutionary problems by considering the shared implications of alleles that produce context-dependent gene expression. From this perspective, adaptive plasticity represents an evolutionary resolution to conflicts of interest that arise from any negatively pleiotropic effects of expression of a gene across ontogeny, among tissues, between the sexes, or across extrinsic environments. This view highlights shared properties within the general relation of fitness, trait expression and context that may nonetheless differ substantively in the grain of selection within and among generations to influence the likelihood of adaptive plasticity as an evolutionary response. Research programmes that historically have focused on these separate issues may use the insights from one another by recognizing their shared dependence on context-dependent gene regulatory evolution. The molecular answer to this challenge is, of course, conditional regulation of gene expression in the control of trait development  3]. Dif. Dif3]. Phenotypic plasticity describes the ability of a single genotype to produce multiple context-dependent phenotypes ,7–9. WheResearch on adaptive plasticity most frequently is associated with phenotypic differences among organisms that arise in response to distinct cues of the external environment ,14. This. 2a). Classic examples include heterophyllic leaf shape of plants in aquatic and terrestrial growth, defensive spine production in Daphnia, and anhydrobiotic responses of tardigrades [When an organism's developmental trajectory responds to distinct environmental circumstances to alter a subsequent phenotype in a manner that enhances fitness in the corresponding environments, then the development of the trait demonstrates adaptive plasticity ,21 figua. Classidigrades –24. In tdigrades ,25. Adapdigrades ; in suchHox genes [b). Second, similarly, a gene's expression at different stages of development may impose opposing effects on proper developmental growth [c). In species with haploid ‘gametophytic’ gene expression, haploid and diploid phases of the life cycle also may present ontogenetic environments with distinctive selective pressures [This view of environment-dependent trait development also applies to other developmental conflicts. First, expression of a given gene in one cell type may increase that tissue's functionality, whereas the same gene's expression in another cell type may depress that other tissue's functionality (e.g. ectopic expression of ox genes ). Such al growth ,29. Tempressures –32. In td). Again, adaptive plasticity in gene expression will provide an evolutionary resolution [Finally, we can consider the sexual context within the body of an individual as an environment to which the development of a shared trait gets exposed ,33,34. Efigure 3solution ,37,39,40These links between tissue-specificity, heterochrony and sex-biased expression that all serve as developmental manifestations of adaptive plasticity may seem self-evident. Nonetheless, they correspond to an underappreciated shared basis to the negatively pleiotropic conflicts inherent to the context-dependence of trait states and gene expression. The measurement of gene expression provides a transferable data type among these domains, with analysis of gene regulation providing a unifying mechanism for exploring diverse aspects of plasticity of traits and the resolution of evolutionary conflicts. By highlighting these connections, lessons learned independently from each of the subfields of ecological adaptive plasticity, sexual conflict and evo-devo may prove mutually informative.. 3x-axis in a reaction norm plot) is viewed as representing distinct environments, then distinct genotypic effects would be interpreted as a genotype-by-environment (G × E) interaction and could represent the basis to local adaptation by specialist genotypes . Countervailing selection pressures in distinct contexts provides one evolutionary means of maintaining genetic variation within a species.In addition to examining individuals that express a fixed allele of a given gene, we can consider genetic variation in the form of alternative alleles with distinct patterns of expression in distinct contexts ,41. Thatb,c). The possibility of such negative pleiotropy over ontogeny motivates the antagonistic pleiotropy model of ageing and senescence [figure 3d). In these circumstances, we may expect the maintenance of functional genetic variation with a suboptimal trait mean in the population that balances the trade-offs of expression and fitness in these distinct contexts [We can also consider reaction norms and tolerance curves with respect to other circumstances in which a trait develops, beyond extrinsic environments . When thfigure 3nescence ,42. Whencontexts ,40,43–45We may then contrast these circumstances with predictions for what would happen should a new allele arise that permits differential expression in the different contexts. Such a new allele with context-dependent expression would ameliorate conflictual G × E interactions by permitting plasticity that enables higher fitness and function of a single genotype regardless of context. It would confer adaptive plasticity of gene expression and trait development, with evolution leading to trait states closer to the fitness optima defined by expression in different tissues, stages, sexes or extrinsic environments . ConsequDo alleles exist that confer gene expression plasticity? Gene expression, like most traits, often shows extensive heritable variation within populations ,47. MoreIt also is important to consider the form of variation in the environment or expression context. The categorical nature of distinct tissues and the sexes naturally lends them to a discrete-state view of differential gene expression as captured with reaction norm analysis ,57. Adap. 4To help link the principle of adaptive plasticity to gene expression plasticity in a mechanistic way, it is instructive to consider explicitly how mutation can create alleles that affect gene regulation to alter expression plasticity. Mechanistic studies provide ample specific examples of gene regulatory evolution that alters the context-dependence of gene expression over ontogeny, among tissues, between the sexes, and across extrinsic environments ,66. To fa). For example, inducing constitutive hyperexpression of the sulfatase eud-1 in Pristionchus nematodes leads to canalized production of one type of mouth form whereas eliminating expression of eud-1 leads to canalized production of an alternative mouth form [cis-acting local alterations near to the coding sequence that influence, e.g. nucleosome occupancy, or from trans-acting distant alterations that influence, e.g. motif binding strength [One type of regulatory mutation could modulate the overall level of expression, increasing or decreasing it in all cells in a non-plastic way a. For exuth form . The kinstrength ,69. SuchCaenorhabditis elegans nematodes as genetically variable trans-acting gene regulators that showed temperature-dependent effects [cis-acting mutation, however, is perhaps the most obvious kind of such a change  would tend to exert fewest additional pleiotropic effects [cis-acting splice modifiers of coding sequence to produce context-dependent alternative splice forms of proteins, trans-acting mutations that operate by regulating upstream transcription factors, or small RNA pathways and mutations that influence post-transcriptional regulation in context-dependent ways [Another type of regulatory mutation could modulate the specificity of expression, increasing or decreasing it in just a subset of cells, stages, sex, or extrinsic environmental conditions. Such a mutation would create an allele with plasticity of expression. For example, 182 ‘expression plasticity quantitative trait loci’ were detected in  effects . A cis-a effects –72. Noneent ways .C. elegans [Different expression contexts may be prone to regulating expression through different pathways. For example, transcriptional regulation predominates for spermatogenesis genes whereas post-transcriptional regulation predominates for other germline genes in  elegans . Similar elegans –76. In t elegans ; analogo elegans . Even co elegans , could mEpigenetic modifications can provide a proximate mechanism for plastic gene expression in ways that yield context-dependent effects ,78,79. Pcis-acting changes tend to accumulate in Arabidopsis to magnify pre-existing plasticity of expression [What remains unresolved, however, is whether any of these molecular mechanisms represent paths of least resistance for the evolution of adaptive plasticity of gene expression as a resolution to evolutionary conflicts over negative pleiotropy in different contexts ,82. For pression . Emerginpression ,85. In apression . These i. 5We would generally expect the population genetic invasion of an ‘adaptive plasticity allele’ . Such anf(x), approaches 1 in the formulation of [f(x) → 1). An allele's expression in a sexual context has a more intermediate grain of selection than do tissues and stages, experiencing sex-specific selection only half of the time in a population with an even sex ratio (i.e. f(x) = 0.5 for autosomal loci, with sex linkage or duplication changing this value), and may encounter some extrinsic environments even more rarely (i.e. coarse-grained with f(x) → 0). Genes expressed late in adulthood also might be considered to have a coarser grain of selection than genes expressed early in life, owing to the diminishing reproductive value of individuals after reproductive maturity.The evolution of adaptive plasticity arises more readily when environments get sampled in a ‘fine-grained’ way. The grain of selection is ‘fine-grained’ when organisms experience different environmental contexts reliably within each generation, in contrast to ‘coarse-grained’ sampling of environmental contexts over the timespan of different generations –92. The ation of : f(x) → The probability of fixation of a new mutation that confers adaptively plastic gene expression is directly proportional to the grain of selection . ConsequAny given regulatory mutation that is capable of conferring adaptive plasticity in gene expression need not fully resolve pleiotropic conflicts. It may simply represent one substitutional step towards that resolution on an adaptive walk . Subsequcis-regulatory architecture or more complex interactions among trans-acting factors that would provide a larger mutational target for deleterious mutations. In practice, however, these potential costs of such additional regulatory complexity may be negligible in most organisms [What limitations to plasticity evolution are there, given that nature shows a preponderance of genes that show differential plastic expression across developmental space , time (ontogenetic stage) and sex? Evolutionary theory nonetheless points to a variety of potential constraints on the evolution of adaptive plasticity . One linrganisms ,98.trans-acting variants [cis-acting variants, reflecting the long-term introduction of mutations that get filtered by selection.A potential short-term constraint on the evolution of plasticity in gene expression as mediated by CRE polymorphisms is owing to CREs tending to be very short sequences. Consequently, any given CRE represents a small mutational target with low opportunity to generate new alleles with plasticity in expression . This prvariants ,100. TheC. elegans nematodes), as molecular mediators of pleiotropy. It is less clear how important this hypothetical cost might prove to be in the context of gene expression plasticity among tissues, life stages and the sexes, but perhaps could be informed by theory on robustness and genetic network architecture [A possible indirect cost of regulatory complexity is a greater potential for catastrophic error, a form of developmental instability ,97. Suchitecture ,101,102.Experimental evolution within stable extrinsic environments has provided one framework for quantifying costs of plasticity –107. CosEven with minimal costs arising from regulatory evolution to confer adaptive plasticity in gene expression, the fitness benefits to further increases in plasticity will face diminishing returns. Another way of phrasing this idea is that the efficacy of selection on plasticity trades off with the extent of context-specific expression of a gene ,110. ThaWhen considered from the perspective of extrinsic environmental heterogeneity, the evolution of adaptive phenotypic plasticity resolves conflicting selection pressures as a means of tolerance . ConsequFor example, selection is less effective on genes with plastic sex-limited expression owing to the coarser grain of selection, which contributes to molecular evolutionary signatures of rapid evolution in genes with sex-biased expression –116. IntIn this discussion of allelic effects, I have neglected evolutionary conflicts that involve the influence of expression in one context affecting fitness experienced elsewhere. Inter-locus sexual antagonism provides perhaps the most familiar case, in which (plastic) sex-limited expression of an allele can lead to reduced fitness of the other sex as a result of inter-sexual interactions ,125–127.. 6The evolution of specialization through the advantages to division of labour offers an alternative lens to view of the evolutionary benefits to differential expression. If the functional capacity of a cell type gives disproportionate fitness gains by virtue of the economies of scale from specialization, then we ought to expect the evolutionary outcome of tissue differentiation and organ specialization ,130. SucThe appropriateness of applying a division of labour lens to the sexes, however, depends on the sexual system. In outcrossing anisogamous species with a single hermaphrodite sex, all individuals share the genome in its entirety with no sex-limited regions . Similarly, the two sexes in haplodiploid organisms share the genome in its entirety . Special. 7Gene expression offers a common currency for understanding diverse problems of evolutionary conflict over negative pleiotropies. The regulatory evolution that affects gene expression as a trait helps to make clear the connections of alleles with negatively pleiotropic fitness effects in distinct contexts, and their evolutionary resolution through adaptive plasticity of gene expression. In particular, adaptive phenotypic plasticity in the form of gene regulatory evolution highlights commonalities among different kinds of evolutionary conflict involving antagonistic fitness effects of gene expression in different sexes, tissues, ontogenetic stages and extrinsic environments. The grain of selection is key to framing the most likely evolutionary response of alleles that confer adaptive plasticity of expression in these various contexts, and future work will be valuable that helps elucidate the potential costs of expression plasticity and whether particular gene regulatory mechanisms are predisposed to resolving some types of negative pleiotropies more than others. By recognizing the shared dependence of distinct research programmes on context-dependent gene regulatory evolution, and measurements of gene expression as a unifying data type, researchers from diverse fields may use the independently derived insights from one another.


Objective: Most methods to detect copy number variation (CNV) have high false positive rates, especially for small CNVs and in real-life samples from clinical studies. In this study, we explored a novel scatterplot-based method to detect CNVs in microarray samples.Methods: Illumina SNP microarray data from 13,254 individuals were analyzed with scatterplots and by PennCNV. The data were analyzed without the prior exclusion of low-quality samples. For CNV scatterplot visualization, the median signal intensity of all SNPs located within a CNV region was plotted against the median signal intensity of the flanking genomic region. Since CNV causes loss or gain of signal intensities, carriers of different CNV alleles pop up in clusters. Moreover, SNPs within a deletion are not heterozygous, whereas heterozygous SNPs within a duplication show typical 1:2 signal distribution between the alleles. Scatterplot-based CNV calls were compared with standard results of PennCNV analysis. All discordant calls as well as a random selection of 100 concordant calls were individually analyzed by visual inspection after noise-reduction.Results: An algorithm for the automated scatterplot visualization of CNVs was developed and used to analyze six known CNV regions. Use of scatterplots and PennCNV yielded 1019 concordant and 108 discordant CNV calls. All concordant calls were evaluated as true CNV-findings. Among the 108 discordant calls, 7 were false positive findings by the scatterplot method, 80 were PennCNV false positives, and 21 were true CNVs detected by the scatterplot method, but missed by PennCNV .Conclusion: CNV visualization by scatterplots allows for a reliable and rapid detection of CNVs in large studies. This novel method may thus be used both to confirm the results of genome-wide CNV detection software and to identify known CNVs in hitherto untyped samples. Copy number variation (CNV) is defined as the genomic presence of a given DNA sequence element >50 bp in copy number different from a reference genome. CNVs are a common type of structural variation in eukaryotic genomes, and single nucleotide polymorphism (SNP) microarray technology enables high-throughput, genome-wide detection of CNVs in many species, including humans. However, due to high noise-to-signal ratios, inter-sample variability and technical differences between microarray platforms, reliable detection of CNVs remains challenging . Most cuIllumina 2.5 M SNP data from 13,245 individuals from the Health and Retirement study , genotypx-axis) against that of the 5′- or 3′-flanking regions (y-axis). Information about the B-allele frequencies (BAF) of SNPs located within the target region was used for further CNV characterization. Three different metrics were calculated to this end for each sample, namely, 1) the total number of homozygous SNPs (defined as BAF<0.01 or BAF>0.99), 2) the total number of di-allelic heterozygous SNPs (defined as 0.47<BAF<0.53), and 3) the total number of tri-allelic heterozygous SNPs (defined as 0.3<BAF<0.36 or 0.63<BAF<0.69). Finally, the difference Δ between the median SNP signal intensity within the target and each flanking region was calculated for each CNV region and sample. Supplementary file 1 and 2 give a more detailed explanation of the scatterplot tool as well as an instruction for use and some more examples of application. A python code for the scatterplot-based calculations, a datafile for the CNV regions analyzed in this study, and an instruction for use are available at https://github.com/thelevinsonlab/CaNVAS_CNV.Six genomic regions with 10 genic CNVs were chosen for visualization with scatterplots . The CNVSeparate satellite clusters that comprised samples of increased or decreased signal intensity were interpreted as harboring duplication or deletion alleles. We did not use predefined cut-off levels to discriminate between carriers of a normal (Copy Number = 2) CNV region and those with a deletion or a duplication. Instead, the scatterplot script produced clearly separated clusters for each analyzed CNV region. Subsequently, individuals were genotyped for this specific CNV region on the basis of the observed pattern of clustering. For further validation of an identified satellite cluster, Δ was plotted against the number of either di-allelic or tri-allelic heterozygous SNPs.Scatterplot-based findings made in the six selected CNV regions were compared to PennCNV calls. A PennCNV call was considered ‘positive’ for a given CNV if it overlapped the target region of the CNV by at least 50%, but was no larger than twice that region. For the validation of both PennCNV and scatterplot-based findings, the microarray data were analyzed with the ‘noise-free-cnv’ software. A CNV call was considered a true positive finding when was validated by visual inspection as described .Sample-wise quality control of the SNP-microarray data was performed with three different metrics: 1) the total number of PennCNV calls per sample, 2) the variance of all autosomal LRR values per sample, and 3) the percentage of successfully genotyped SNPs  per sample. Samples were ranked according to each quality metric and labelled better  PennCNV calls, lower variance, or higher call rate) than x% of all analyzed samples.Six CNV regions were analyzed with two different CNV calling methods in 13,254 high-density SNP microarray datasets . All regAnalysis with PennCNV software yielded 1099 CNV calls whilst scatterplot visualization suggested the presence of 1047 CNVs in all regions combined . Of the Visual inspection of the 108 discordant calls and of 100 randomly selected concordant calls revealed that all concordant calls were most likely true CNVs. Of the 108 discordant calls, 80 were PennCNV false positives and 7 were scatterplot false positives . The remOverall, 1040 true CNVs comprising 267 duplication and 773 deletion B-alleles were recorded in the six regions studied . Figure Since quality control (QC) filtering and the exclusion of low-quality samples is common practice prior to PennCNV analysis, we assessed the performance of PennCNV and the novel scatterplot-based method after QC filtering steps of varying stringency . The ratThe present study has two key findings: 1) Visualization of CNV regions by signal intensity scatterplots allows a rapid validation of PennCNV calls, even in large study populations, and 2) compared to PennCNV, scatterplot-based CNV calling has lower false positive and negative rates, even without the prior exclusion of low-quality samples from further analysis. In the large dataset analyzed here, PennCNV yielded about 10% false positive and negative findings combined whilst the error rate of scatterplots was around 1%. Our study also revealed that the exclusion of low-quality samples results in a significant reduction of the error rate mostly for PennCNV, and less so for the scatterplot-based approach. Overall, it may thus be concluded that the use of scatterplots not only allows rapid and reliable validation of PennCNV calls, but also enables the extension of CNV analyses to low-quality cases which would otherwise be excluded. Finally, scatterplots may help to identify some PennCNV findings in discovery samples as false positives, and may identify additional true CNVs that went undetected by PennCNV.The above notwithstanding, our study also has some limitations. Only a small number of known CNV regions were covered. The performance of the scatterplot analysis across different SNP-microarray platforms and in cases with clonal mosaicism was only illustrated in a supplementary file and not analyzed in depth. CNV-regions close to the centromeres or telomeres may be subject to very strong genomic waves and may therefore be enriched for false-positive PennCNV deletions. None of the CNV-regions analyzed in this study was located in subtelomeric or pericentric regions. We nevertheless observed heterogeneity across the analyzed CNV regions with the majority of the false-positive PennCNV findings occurring in a single region. Since this clearly gives our current work the character of a pilot study, we are planning a follow-up study to analyze a larger set of syndromic CNVs  in samplpost hoc evaluation did not allow estimation of the underlying sensitivity and specificity values of the two approaches.Visual inspection of discordant CNV calls, both with or without prior reduction of systemic noise, allowed us to distinguish between true and false positive findings. The final set of confirmed true CNVs was then used as a ‘gold standard’ for the comparative evaluation of the false positive and negative rates of PennCNV and of our scatterplot-based method of CNV detection. Since CNVs that were not recognized by either tool were not considered, this It is important to underline some fundamental differences between tools that were developed for the genome-wide detection of any potential CNV (like PennCNV) and the current scatterplot method that is a tool for the analysis of CNV in a specific, predefined genomic region. Whereas PennCNV allows the identification of an infinite number of different CNVs, the scatterplot tool discriminates between a very limited number of copy number states within a single genomic locus. As a consequence, there is an innumerable set of potential false PennCNV findings, whereas the number of potential false scatterplot findings is small. Another important difference between both strategies is that scatterplots of very large study populations show particularly clear clusters, whereas PennCNV analysis of very large study population becomes extremely laborious. Whereas the PennCNV tool was developed for the genome-wide analysis of single individuals one after another, the scatterplot tool was developed for the genotyping of a single CNV-locus simultaneously in a large study population.CNV calling with the aid of scatterplots has several advantages. Similar to SNP genotyping , visualiab initio by other, automated detection algorithms, or may be used for the targeted analysis of known pathogenically relevant CNV regions in large study populations.In conclusion, our study demonstrates that the use of scatterplots represents an efficient tool for both CNV visualization and validation. The method could be incorporated into existing analysis pipelines to evaluate CNVs called


We also show that applying spatial prioritization is key to maximizing the achievable potentials of abandoned cropland and demonstrate other possible approaches to further increase these potentials. Our findings offer timely insights into the potentials of abandoned cropland and can inform sustainable land management to buttress food security and climate goals.Despite the looming land scarcity for agriculture, cropland abandonment is widespread globally. Abandoned cropland can be reused to support food security and climate change mitigation. Here, we investigate the potentials and trade-offs of using global abandoned cropland for recultivation and restoring forests by natural regrowth, with spatially-explicit modelling and scenario analysis. We identify 101 Mha of abandoned cropland between 1992 and 2020, with a capability of concurrently delivering 29 to 363 Peta-calories yr This work demonstrates how global abandoned cropland is an untapped land resource. If recultivated and reforested strategically, it can provide substantial carbon sequestration and food production potential to support our shared climate and food security goals. Despite overall progress on yield improvements and functioning of agriculture value chains for the last decades3, by 2021, around 702 to 828 million people, or 9.8% of the world population, were still undernourished4. Although agricultural intensification has the potential to reduce the pressure of expanding cropland, the ongoing population growth and increasing per capita food consumption suggest future cropland expansion is inevitable. Recent projections with the Shared Socioeconomic Pathways (SSPs) scenario framework estimated a total cropland expansion of 25 to 226 Mha over the next three decades, from the most to the least sustainable scenarios6. Future expansion of cropland would put areas with high environmental values and biodiversity-rich frontiers at risk10.Global cropland expansion has been going hand-in-hand with rapid population growth and food demand increase during the last 300 years11. Land management measures that reduce emissions from the food sector are a vital part of international efforts to mitigate climate change. Along with other nature-based climate solutions , these measures represent a large proportion of mitigation actions to keep the global average temperature increase below 2 °C and have been integrated into many countries’ National Determined Contributions (NDCs) under the Paris Agreement13. However, deploying these climate change mitigation measures at scale to limit global warming below 2°C would require large swaths of land , thereby putting these measures into conflict with future cropland expansion14.At the same time, the food sector has been contributing significantly to climate change, accounting for about one-third of total anthropogenic GHG emissions17. Estimates from satellite imagery show that along with 217 Mha of gross cropland expansion, extensive gross cropland abandonment (79 Mha) took place globally from 2003 to 20191. Cropland abandonment is predicted to continue in abandonment hotspots, such as Europe, Russia, Central and East Asia, and the Americas18. While cropland abandonment gives rise to threats to food security, recent studies and land management projects  highlighted the feasibility of abandoned cropland to be cultivated again for supplying food production (recultivation) or to be restored to natural habitats via natural growth (reforestation) for enhancing carbon sequestration24.While the looming land scarcity for agriculture and the intensifying conflicts in land-use demand, cropland abandonment is widespread globally as a result of land degradation, institutional and socioeconomic changes, disasters, armed conflict, and urbanization25. Assessments of trade-offs and synergies across different purposes of using abandoned cropland are also generally lacking. In most cases, assessment is based on a sole purpose in mind 27. Alternative purposes are insufficiently considered, even though the area of interest is more suitable to serve other purposes28. At the same time, it has been recently reported that abandonment can be ephemeral, swinging between different land-use purposes, e.g., between producing food and sequestering carbon29. Thus, this underscores the importance of understanding the potential and trade-offs between different purposes of using abandoned cropland and calls for a better land-use management strategy for abandoned cropland. In addition, given the spatial variability in crop yield and carbon sequestration rates across the globe, spatially prioritized land management strategies are essential in helping various stakeholders seek the most beneficial and optimum solutions26. Understanding the benefit of applying spatially prioritized strategies is essential to best achieve the potential of abandoned cropland and craft win-win synergies.It remains unclear regarding how recultivating and reforesting global abandoned cropland can support food production and climate change mitigation, respectively, and how they are pertinent to achieve food security and climate goalsHere, we assess the potential and trade-offs of using abandoned cropland for food production and climate change mitigation based on geospatial modelling, machine learning, and scenario simulation approaches. We aim to address three research questions: (1) how much global abandoned cropland is suitable for recultivation and reforestation via natural regrowth, respectively, and what is the resulting potential for food production and climate change mitigation? (2) how to balance the trade-offs between these two purposes? (3) how to maximize their synergies, as well as the achievable potentials? Collectively, our analysis offers timely insights into the untapped potential of abandoned cropland that can inform land-use decision-making processes and support policymakers in meeting ambitious food security and climate goals from land-use sectors.-1 (see Methods). The extent of abandoned cropland corresponds to 7.0% and 6.4% of active cropland areas in 1992 and 2020, respectively. This finding confirms cropland abandonment is prevailing in Asia (33 Mha), Europe (22 Mha), and Africa (19 Mha), particularly in Russia (12.4 Mha), China (8.7 Mha) and Brazil (8.4 Ma)  of cropland was abandoned between 1992 and 2020—equivalent to an average cropland abandonment rate of 3.6 Mha yrMa) Fig. .Fig. 1Gl30, we report the overall accuracy (83%), user’s accuracy (95%), producer’s accuracy (77%), and F1 score (0.85) of our abandoned cropland map from 1992 to 2020, which are within the range of mapping accuracies of previous studies32 (see Methods). Besides, a qualitative comparison against the other 42 studies with different abandonment identification approaches, input datasets, and study periods shows that the spatial pattern of our identified cropland abandonment is well consistent with previous studies, such as the abandonment due to socioeconomic and institutional changes (collapse of former Soviet Union)33, regional conflicts 34, biophysical constraints 36, and shifts in land-use policy (Thailand)37 , with a potential to feed 292 to 476 million people per year based on different diets and calorie intake conditions . If all suitable abandoned cropland is naturally reforested, it could sequester an amount of carbon by 1,080 MtCO2 yr-1, thus making it an important but missed opportunity to accelerate efforts to mitigate climate change  – to assess the integrated benefit under each scenario. Among all scenarios, the “maximizing combined potential” scenario allocates abandoned cropland pixels to the optimal purpose by considering the comparative advantage of each pixel based on its cropland productivity and carbon sequestration rates. This scenario yields the highest combined potential 143%), concurrently achieving 79% of maximum food production potential and 72% of maximum climate change mitigation potential  only target recultivating or reforesting a certain amount of suitable areas rather than all of them, thus making knowing where to prioritize and the benefits of prioritization imperative.The remarkable difference in the simulated outcomes across space and scenarios underscores the necessity for applying spatially prioritized land management strategies to make full use of the potential in abandoned cropland. It is also very pertinent to land management because, due to limited resources, most real-world efforts .We assessed the impact of applying a spatially prioritized allocation strategy on the resulting potential of abandoned cropland by comparing outcomes simulated with and without spatial prioritization  across different percentages of abandoned cropland that are used. We find spatial prioritization can increase food production and climate change mitigation potential by up to 59% and 43% . Our further analysis indicates that recultivation or reforestation of abandoned cropland spatially prioritized in the following regions could yield the best food production and climate change mitigation outcomes: Central and Eastern Europe, East and Southeast Asia, Central Africa, and South America with Russia, Brazil, and China standing out as top 3 countries 46. However, these hurdles could be at least partially overcome in the future. First, improving the water supply from a rain-fed to an irrigated condition will increase achievable food production potential by 62%. Second, if cropland yields in areas with identified yield gaps are improved to attainable yields by agricultural intensification and high-level agricultural inputs , we then predict a 40% increase in food production potential . Future climate change would bring a marginal benefit to crop yields and a 3-12% increase in food production potential, depending on various climate forcing and water supply conditions . The accumulated aboveground biomass carbon via natural regeneration is reported to take more than 60-80 years to recover to 90% of the old-growth forest level49. At the same time, abandoned croplands that experience natural regeneration may face intense threats of being recultivated unless policy interventions are implemented18. If we actively reforest abandoned cropland  outside global protected areas defined by IUCN and UNEP, our nonspatial estimate predicts an increase of 53 ± 18% (mean + std) on the achievable climate change mitigation potential, with a potential to free up 17 Mha abandoned cropland for recultivation and generate 45 Pcal yr-1 food production potential (+153%) 12.When modeling climate change mitigation, we based our estimate of the carbon sequestration rates on natural forest regeneration on avoiding adverse impacts on local biodiversity50. Recultivating abandoned cropland would help to offset the geographical displacement of cropland expansion and the subsequent environmental impacts, such as deforestation51 and wetland loss52. Abandoned croplands that area available for reforestation (83 Mha) and recultivation (61 Mha) also show substantial potential to offset future land-use demand, e.g., up to 372 Mha of new cropland expansion and 145-250 Mha of net forest growth (SSPs-26 scenarios by 2050), and ease the intensifying land-use competition6.Our study shows that abandoned cropland can be a promising avenue for unlocking additional land resources in a world where land scarcity remains a major hindrance to sustainable development. If recultivated and/or reforested strategically, abandoned cropland can make a considerable contribution to meeting food security and climate goals. In addition, reforesting abandoned cropland via natural regrowth could bring an array of co-benefits, such as enhancing biodiversity conservation, water filtration, air filtration, and soil quality39, grassland restoration53, and rewilding54. For example, bioenergy crops have been expected to play an important role in reaching the 2°C climate goal, with a projected sharp increase of 1.0 to 3.0 Gt dry matter per year from 2020 to 2050 (SSP2-2.6 scenario)55. Delays in bioenergy crop deployment would even threaten food security as global warming causes feedback loops with associated decreasing crop yields56. Thus, abandoned cropland can complement such rising demand for bioenergy crops. However, there is also debate on bioenergy crops due to their low land-use efficiency, which might exacerbate land competition and lead to displaced cropland expansion and carbon emission57. Further scrutiny into these alternative uses of abandoned cropland is needed for the best use of abandoned cropland.In addition to recultivation and reforestation, abandoned cropland can be used for other purposes, such as growing bioenergy crops58. Besides, the ongoing shift towards more meat-intensive diets may limit the potential of abandoned cropland for food production59, as livestock-based production requires significantly more land than cereal-based production to generate the same amount of calories14. In our study, we assumed that all selected crops were consumed directly by humans rather than as animal feed. However, a recent study predicts that 34% of crop production in China will be used for feeding livestock51. At last, securing the permanence of food production potential and climate change mitigation potential needs policies and incentives across sectors. Without these efforts, recultivation and reforestation would become ephemeral activities and would consequently reduce the achievable potential of abandoned cropland18.It should be noted that various factors may hamper endeavors to access and utilize abandoned cropland, thus reducing its potential. For example, armed conflicts or regional economic rivalries can have significant impacts on international trade openness, labor availability, market access, and agricultural productivity, which consequently reduce the suitability of abandoned cropland for recultivation and reforestation and/or its potential60. Additional information, such as spatial and demographic data about food insecurity, can guide actions directing limited food production to do the greatest good61. Similarly, although the climate change potential obtained from abandoned cropland can offer an important pathway for meeting emissions reduction targets that countries have committed in their NDCs under the Paris Agreement62, globally collaborative efforts are required to build and scale up a trustworthy carbon market. This is essential to ensure the carbon offset obtained from reforesting abandoned cropland can be coordinated across sectors and countries.While these is a considerable amount of food production and climate change potential achievable from abandoned cropland, further efforts are needed to transform these potentials into grounded benefits. For example, in addition to the increased food provision by recultivating abandoned cropland, it is imperative to improve the accessibility, affordability and effective utilization of food products so that the global food deficit can be addressed63, the UN Decade on Ecosystem Restoration64, SDG 1565, Initiative 20-by-20 of COP 2066, and China’s green for grain project67.Understanding the trade-offs and spatial priorities in using abandoned cropland is crucial for making land management decisions. Our study demonstrates the plausible outcomes across various trade-off options of abandoned cropland and approaches to maximize the synergies. We also offer broad spatial guidance on where decision-makers should prioritize their land management efforts. These insights are essential to support global and regional initiatives aimed at sustainable land stewardship, such as the Bonn Challenge69. Even so, these limitations do not undermine the utility of our global-scale findings but rather recognize the importance of across-scale information. Global-scale findings can provide a broader context for local decisions on abandoned cropland management and are essential in such an increasingly interconnected world with globalized decision-making70. We emphasize the necessity of incorporating context-specific information at the local scale with our global scale findings to ensure that knowledge on an optimized and synergetic use of abandoned cropland can be transferred into grounded actions that can also benefit local communities. Context-specific information at the local scale includes but is not limited to local land-use policy, land tenure, local land-use policies, culture, cost, and labor availability71. Taking local land-use policy, for instance, if the abandoned cropland is already assigned for oil palm plantation with a concession from local government—commonly steered land-use conversion in pantropical areas—recultivation and reforestation would no longer be allowed. Our further calculation shows that, in this case, about 0.66 Mha of abandoned cropland in our study would become unavailable for both purposes , which can lead to net biophysical warming77.Nevertheless, our global-scale findings have a few limitations. Harnessing and reaching a globally optimized utilization of abandoned cropland will require overcoming the hurdles in global coordination and policy differences. Besides, global maps have been receiving rising critics and debates, particularly on the mismatch in the scale that maps are generated  and land-use management policies are implemented Our study demonstrates that unlocking the potential of abandoned cropland offers substantial benefits for food production and climate change mitigation, while synergies of these benefits open up new opportunities for meeting the Paris Agreement’s climate goals, SDG 2 (zero hunger), and SDG 15 (restoring degraded land and increasing afforestation). Our simulated outcomes and trade-off analysis can be translated into valuable insights for policymakers and land-use planners to guide global and regional initiatives. Our analysis also highlights key levers for maximizing the potential benefits of abandoned cropland, including employing spatial prioritization strategies and ensuring a globally coherent effort.We analyzed the potential and trade-offs between recultivation and reforestation of using global abandoned cropland to support food production and climate change mitigation in the 30-year period from 2020 to 2050, with the help of multi-source geospatial datasets, machine learning model, and geospatial and scenario simulation approaches. The following sections describe the datasets and methods used in this study.79. This dataset has been widely used for characterizing long-term changes in the Earth’s surface, including identifying land cover transitions, analyzing cropland dynamics and mapping cropland abandonment82. Following the correspondence IPCC land categorization and the ESA-CCI land cover classification system, there are six land cover classes in ESA-CCI maps representing different cropland types79. These cropland classes exhibit global user’s and producer’s accuracies of 81% and 92% (median), with an overall accuracy of 83%. The classification accuracies of cropland classes are among the highest of all classes in the ESA-CCI product.We utilized the ESA-CCI product to identify and map global abandoned cropland. ESA-CCI is a land cover map dataset at a 300-m resolution (10 arc-second) and on a yearly basis from 1992 to 202083. Three additional operations were implemented to further refine abandoned cropland mapping: (1) a five-year moving window temporal filter was applied to annual cropland maps. If one pixel has a different land cover class, two years before and after will be assigned to the same land cover class. ESA-CCI has already implemented a consistency rule that each change has to be confirmed over more than two successive years in the classification time series. Our temporal filter can further remove unlikely land-cover changes and to improve temporal consistency in cropland maps84, particularly from 1992 to 1999, which has been reported with a low reliability79. It helps to eliminate single-year misclassification in our subsequent abandoned cropland maps and recultivation maps. (2) only historically stable cropland was considered (a pixel was cropland during 1992-1997); (3) cropland converted to settlement and wetland, and abandoned cropland once recultivated (abandoned cropland converted back to cropland for at least one year) were excluded. In this way, we could avoid overestimating pixels under short-term fallow as abandoned cropland and exclude ephemerally abandoned cropland, e.g., recultivated after a few years’ abandonment18, thereby presenting a relatively reliable estimate of abandoned cropland extent. It should be further noted that we focused on abandoned cropland exclusively because abandoned pasture is challenging to discern from satellite images against natural grassland18.We used a relatively conservative strategy to identify abandoned cropland with the annual cropland maps aggregated from all six cropland classes of ESA-CCI. FAO’s definition of abandoned cropland was adopted - cropland that has not been used for at least five years; that is, a pixel was first cropland and then converted to non-cropland classes for at least five consecutive years (excluding built-up areas)86. The coarse resolution of ESA-CCI may limit its utility of monitoring cropland abandonment in the regions where agricultural fields are small, such as Africa87. Future endeavors to map global cropland abandonment with datasets in higher spatial resolutions  could help to address these limitations88. Here, we used a sampling-based approach to assess the accuracy of our identified abandoned cropland map and to derive error-adjust area estimate. We followed ref. 89 to determine the validation sample size and adopted the disproportionate stratified sampling strategy to validate our abandoned cropland map. This strategy is designed and suitable for assessing the classification accuracy of small classes, such as abandoned cropland89. For abandoned cropland and nonabandoned cropland classes, we randomly selected 828-pixel samples for each class  derived from Google Earth Engine also aided validation sample collection87. If neither VHS historical imagery nor cloud-free Landsat image is available for a selected sample, this sample would be discarded and a new sample of the same class would be selected. In the case of mixed pixels, we followed the class definition – cropland coverage>50% – based on “Correspondence between the IPCC land categories for change detection and ESA-CCI classes”79. To account for possible sampling bias, we reported the overall accuracy, producer’s accuracy, user’s accuracy, and F1 score of our abandoned cropland map at the global scale and continental scale . We acknowledge that removing highly mixed samples and the ones in cloud-frequent regions may have inflated our accuracy estimate, such as in Africa where fields are very small , and errors propagated and aggregated from misclassified pixels in each year91. We estimated the suitability and potential of each purpose separately.We considered the two most viable purposes of using abandoned cropland—recultivation for food production and reforestation via natural regrowth for climate change mitigation. Their feasibilities have been confirmed by studies and practices in local and regional cases47, market accessibility31, travel time to settlement92, population density31, adjacent cropland density93, distance to stable cropland26, abandoned cropland density26, INFORM Risk Index of natural and human-induced disasters94, and annual economic loss due to natural hazards95  was trained using normalized driving factors and historically recultivated pixels96, and then optimized by factors adjustments and model parameter tuning97. We used the fine-tuned MaxEnt model to estimate the abandoned cropland prone to recultivation . The recultivatable abandoned cropland was determined by a recultivatability larger than 0.2, while pixels with recultivatability values lower than 0.2 were considered as not likely to be suitable for recultivation due to substantial biophysical, agricultural and socioeconomic barriers. At last, protected areas, jointly defined by UNEP and IUCN, were masked out to avoid adverse ecological impact98. Model performance and sensitivity analyses are presented in Supplementary Text We used a machine learning-based approach to estimate the suitability of abandoned cropland for recultivation, trained using driving factors of recultivation and abandoned cropland pixels that were historically recultivated. The potential drivers of recultivation covered biophysical and socioeconomic aspects, including integrated agroecological suitability99 and data availability in the Global Agro-Ecological Zoning database (GAEZ v4), a modelling framework co-produced by FAO and IIASA47. The GAEZ has been one of the most widely used datasets for providing global-scale estimates of crop-related information, including harvest areas and crop yields101. GAEZ model and its outputs have been validated by (1) comparisons against other modeling outputs103, (2) comparisons against statistical records104, and (3) comparisons against crop yields map estimated by bottom-up approaches , such as GYGA dataset106 , crop yields, and crop allocations, as well as estimations reflecting the impacts of future climate change  to dry-weight-based calorie yield , using conversion factors in GAEZ document47 and FAO food balance sheets108. We also converted integrated food productivity from harvest-level to consumer-level by deducting food waste and loss during production, supply chain and consumption. We adopted the food loss percentage from FAO’s food loss index109 and set a uniform food waste percentage of 17% according to the latest UNEP report110  is calculated by Eq.  map43. The aboveground carbon sequestration rate map is based on 257 historical studies and 13,112 georeferenced measurements and an ensembled machine learning model. The belowground carbon sequestration rate is estimated post hoc using the IPCC default root-to-shoot ratio112. The spatial variation of carbon sequestration rates across different climate zones, land-use types, forest types, and other factors are better presented, which is essential for identifying high carbon sequestration rate areas for prioritized actions. Aboveground and belowground biomass carbon was considered, but not soil organic carbon. It was because the soil carbon accumulation rates after natural regrowth were found negligible or negative, even contrasting across studies113. Unlike changes in aboveground and belowground biomass carbon, soil carbon change during forest natural regrowth is understudied and short of measurements. While this carbon sequestration rate map is one of the best available data, there are factors that the mapping failed to account for, such as differences in forest stages and local water supply conditions. We thereby present the uncertainty of the carbon sequestration map and its impact on our climate change mitigation estimation using the corresponding error rate layer  , shrub (10%) and bareland (11%). For areas under natural regeneration, the accumulated biomass carbon was directly estimated by the map of Cook-Patton, et al.43. For abandoned cropland that was currently grass, shrub and bareland, the accumulated biomass carbon was estimated by the carbon stock map from Spawn, et al.114. The breakdowns of net climate change mitigation potential are presented in Supplementary Text 2e t-1 during prefarm, on-farm, and postfarm stages115. However, we did not include life cycle emission of recultivation in our analysis mainly because of the lack of spatially explicit life cycle emission data for all 15 crops considered in our study.Second, we estimated the emission from clearing the historically accumulated aboveground biomass carbon when preparing the abandoned cropland for recultivation. We assumed that all the accumulated aboveground biomass carbon would be immediately oxidized and lead to one-time emissionIn this way, we obtained maps of suitable abandoned cropland for recultivation and reforestation. We further categorized them into four suitability types, including areas only suitable for either recultivation or reforestation, areas suitable for both, and areas suitable for neither purpose Fig. . We alsoBased on the modeled suitability and potential, we simulated scenarios to evaluate trade-offs between recultivation and reforestation. These simulated scenarios present the outcomes of different options in utilizing abandoned cropland. Each simulation was determined by the amount of abandoned cropland to be used in total and for either purpose, the locations of abandoned cropland to be allocated for each purpose, and the way of allocation . For simulations applying a spatially prioritized land allocation strategy, pixels with higher integrated cropland productivities or carbon sequestration rates were allocated first. It should be further noted that each 300-m abandoned cropland pixel was only allocated for a single purpose, either recultivation or reforestation. This scenario analysis serves to contrast different options in using abandoned cropland and determine how synergies of food production and climate change mitigation could be maximized. A detailed explanation of the simulation processes is presented in Supplementary Text -1; A) and climate change mitigation potential ; (2) the achieved combined potential in percentage (A + B), which serves as a hypothetical indicator to demonstrate the integrated outcome of recultivation and reforestation of each scenario.To assist comparison of the simulated outcomes across scenarios, we calculated the following metrics in addition to food production potential and climate change mitigation potential: (1) the percentage of achieved potential relevant to the maximum achievable food production potential . The future climate forcing was the ensemble mean of five climate models GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM, and NorESM1-M, obtained from the bias-corrected Intersectoral Impact Model Intercomparison Project (ISI-MIP)118. For reforestation, we considered the potential improvement in climate change mitigation potential if we actively reforest suitable abandoned cropland instead of via natural regrowth (see Supplementary Text Our estimates of the food production potential and climate change mitigation potential are conservative. There are a few possible approaches to improve the achievable potentials and free up land for other use. We considered the following possible approaches and quantitatively assessed their benefits in improving the achievable potential of abandoned croplands. For recultivation, we considered the impacts of improvements in water supply conditions from rain-fed to irrigated, crop yields from actual yields to attainable yields for areas with identified yield gaps (Supplementary Figs. Further information on research design is available in the Supplementary InformationPeer Review FileDescription of Additional Supplementary FilesSupplementary Data 1- 4Reporting SummarySource Data


Inclined walking is a challenging task that requires active neuromuscular control to maintain stability. However, the adaptive strategies that preserve stability during inclined walking are not well understood. Investigating the effects of self-paced inclined treadmill walking on gait stability characteristics and the activation patterns of key lower limb muscles can provide insights into these strategies.The aim of this study was to investigate the effects of self-paced inclined treadmill walking on gait stability characteristics and the activation of key lower limb muscles.Twenty-eight able-bodied individuals  walked on an augmented instrumented treadmill for 3 minutes at 3 inclination angles  at their preferred walking speed. Changes in gait characteristics  across inclination angles were assessed using a repeated measures ANOVA and the Friedman test.P<.001). Changes were observed in spatial-temporal parameters, joint angles, and muscle activations depending on the treadmill inclination. Specifically, stability and walking speed decreased significantly during uphill walking, indicating that it was the most challenging walking condition. Uphill walking also led to a decrease in spatial parameters by at least 13.53% and a 5.26% to 10.96% increase in temporal parameters. Furthermore, joint kinematics and peak activation of several muscles, including the hamstrings , gastrocnemius , and vastii muscles  increased significantly during uphill walking. In contrast, downhill walking resulted in bilateral reductions in spatial-temporal gait parameters, with knee flexion increasing and hip flexion and ankle dorsiflexion decreasing. The peak activation of antagonist muscles, such as the quadriceps, tibialis anterior, and tibialis posterior, significantly increased during downhill walking .The study revealed that inclined treadmill walking has a significant impact on gait characteristics (Our findings demonstrate that able-bodied individuals adopt specific walking patterns during inclined treadmill walking to maintain a comfortable and safe walking performance. The results suggest that inclined treadmill walking has the potential to serve as a functional assessment and rehabilitation tool for gait stability by targeting muscle training. Future research should investigate the effects of inclined treadmill walking on individuals with gait impairments and the potential benefits of targeted muscle training. A better understanding of the adaptive strategies used during inclined walking may lead to the development of more effective rehabilitation interventions for individuals with lower limb injuries. Inclined walking is a challenging daily mobility activity that requires complex adaptation to maintain gait stability compared with level walking -3. EvideOther biomechanical literature has shown the impact of inclined walking on gait performance, including changes in postural adaptations , kineticFortunately, technological advancements in instrumented treadmills can be advantageous in overcoming many limitations in previous literature. These cutting-edge treadmills are laboratory based, designed with split belts, and equipped with 2 embedded force plates . They diTherefore, this study aimed to investigate the effects of inclination angle during self-paced treadmill walking on gait characteristics  and on the peak activations of key lower limb muscles. In this study, we sought to use the novelty of the gait real-time analysis interactive lab (GRAIL) system to collect rich, highly accurate, and reliable gait data in real time during a self-paced inclined treadmill walking within a VR environment. We estimated gait stability by calculating the GSR, and we employed the HBM model to obtain a more comprehensive understanding of the walking patterns and muscular adaptations in healthy individuals during self-paced inclined treadmill walking. This study would yield valuable knowledge on gait stability and adaptive strategies during walking at different inclinations.A within-subject repeated-measures study design was used.Twenty-eight able-bodied adults  participated voluntarily in this study, which took place at the Cardiff University School of Healthcare Sciences. Participants were recruited from Cardiff University and local communities. Interested individuals who did not have any medical, musculoskeletal, neurological, cardiovascular, or vestibular impairments that may affect their gait were invited to sign a written informed consent prior to participation. The protocol of this study was approved by the Cardiff University School of Healthcare Sciences Research Ethics Committee.3D kinetics, joint kinematics, and spatiotemporal parameters were collected bilaterally using the GRAIL  system at Cardiff University. The GRAIL system comprises an instrumented dual-belt treadmill with 2 embedded force platforms, a VR system projected onto a 180° screen, and a 10-camera motion tracking system . The speed of the 2 belts was set to the self-paced mode for each participant, as described by Sloot et al . AdditioAll participants attended a single session at our movement analysis laboratory. Twenty-five reflective markers were placed on the participant’s body according to the HBM (Motek) lower limb marker set . The calEach participant completed a 3-minute self-paced walking trial under each of the 3 walking conditions in random order. The 3 trials were performed consecutively with at least 2 minutes of rest in between to allow for recovery. Participants were not given any instructions during walking trials, and talking was not permitted in the laboratory to avoid any distractions that might affect their walking performance.F/Fmax) were calculated based on moment arms, joint moments, skeletal pose, and polynomial equations for 11 muscles around the knee joint bilaterally [This study used the HBM model that is embedded in D-Flow software  to estimate all gait parameters, including muscle force, stride length, and joint angles. Estimated muscle activation levels  was used to perform all statistical analysis.The analysis aimed to compare gait characteristics and muscle activation levels across the 3 walking conditions. Therefore, a repeated-measures ANOVA and the Friedman test were used to explore the effect of inclines on lower limb muscle activity and gait parameters after testing the normality of the data by the Shapiro-Wilk test. The level of statistical significance was set at This study involved human participants; informed consent was obtained from all participants in the study and all procedures were approved by the Cardiff University School of Healthcare Sciences Research Ethics Committee. Informed consent was obtained from all participants, and the original consent allows for secondary analysis of the research data without additional consent. Participants’ privacy and confidentiality were strictly protected by anonymizing and coding the collected data to prevent identification. No compensation was offered for participation in the study, as participants were recruited on a voluntary basis.During uphill walking, all spatial-temporal gait parameters changed significantly compared to level walking. Inverse relationships were noted between parameters, such as a significant increase in GSR by 15.58% during uphill walking and a significant reduction in walking speed by 23.14%. Additionally, spatial parameters decreased significantly by at least 13.53% during uphill walking compared to level walking, while temporal parameters significantly increased by 5.26%-10.96%.During downhill walking, almost all spatial-temporal gait parameters showed bilateral reductions compared to level walking, except for GSR values, which increased by 3.46%. The mean walking speed during downhill walking did not show a significant change relative to the mean speed during level walking .P<.001). However, mean max hip abduction, hip rotation, and knee flexion were significantly reduced during uphill walking compared to level walking . During downhill walking, the mean max knee flexion significantly increased from about 62° during level walking to about 68° during downhill walking (P<.001), while mean hip flexion and ankle dorsiflexion were significantly reduced (P<.001). The results did not show significant differences in joint angle kinematics between both sides across walking conditions . Interestingly, however, the rectus femoris (RF) was the only quadriceps muscle that showed significantly less activation bilaterally during uphill walking compared to level walking (P<.001), while both tibialis anterior (TA) and tibialis posterior (TP) muscles showed a significant decrease in activation bilaterally during uphill walking (P<.001).During uphill walking, most muscles showed a significant increase in peak activation, including the hamstrings , quadriceps, and gastrocnemius , with RF showing the highest peak activation among all muscles. The hamstrings, gastrocnemius, and soleus muscles were significantly less activated during downhill walking compared to level walking. Notably, the peak activation of TP was significantly higher (P<.001) on the right side than the left side .During downhill walking, the quadriceps, TA, and TP muscles showed a significant increase in mean activation in both lower limbs  more than those of the quadriceps  and the plantar flexors . These muscular adaptations would support the pronounced role of the hamstrings in absorbing power from the trunk and producing forward momentum in both legs to propel the body up the inclined surface , so it hOur findings suggest that inclined treadmill walking can be a valuable tool for assessing gait stability and has potential to be incorporated into clinical assessments, particularly for patients at risk of falling during inclined walking, neuromuscular training, and fall prevention programs in rehabilitation. However, our results should be interpreted cautiously, since we only studied the effects of self-paced inclined treadmill walking in young, able-bodied participants and did not measure hip and ankle muscles, which limits the generalizability of our findings. To overcome this limitation, future research should recruit individuals with impaired gait stability, such as older adults or those recovering from an injury or illness, and measure other muscle groups. Additionally, determining the minimal clinically important difference in gait stability ratio or other parameters to prevent falls could be a promising avenue for future studies. Our study provides a baseline for future research investigating the effects of different types of inclined walking on gait stability in diverse populations.This study provides evidence that inclined treadmill walking is a challenging activity that requires adaptive neuromuscular control strategies to preserve stability. Results showed that the inclination angle of the treadmill significantly affected overall gait characteristics, reflecting changes in gait parameters and muscle activations. Of all walking conditions, uphill walking had the greatest impact on gait stability and walking speed reduction. Our findings suggest that inclined treadmill walking may serve as a functional assessment tool or rehabilitation intervention to improve gait stability and strengthen specific muscle groups. Further research is needed to investigate the effects of inclined treadmill walking on other patient populations and to identify the potential benefits of targeted muscle training.


These tools are vulnerable to bias, and do not objectively assess functional morbidity associated with sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND).3 Objective measures, such as goniometry and tape arm measurements, rely on the operator’s skills and may be problematic owing to inter-observer variation.4 A recent systematic review emphasized the need for quantitative and validated outcome measures, as well as the lack of standardization in the measurement of upper limb morbidity.1Breast and axillary surgery can impair arm movement, restrict physical function and limit quality of life.5 An objective, longitudinal measurement of PA during the post-operative period would provide more information to the patient and surgeon about the upper limb and total activity levels associated with their surgery. WAMs could reduce measurement and operator variability while monitoring post-operative upper limb activity levels in a non-invasive and unbiased manner. WAMs objectively demonstrate return of PA to pre-operative baseline and differentiate recovery across different surgical treatments. This study investigated the use of WAMs to compare physical recovery between ALND and SLNB.6 Based on the analysis of 56 patients , the findings demonstrated that ALND resulted in a significantly lower PA level in week 2. In addition, physical restrictions following SLNB persisted for 2 weeks following surgery. This is an important finding because it suggests that even de-escalated axillary procedures are associated with prolonged morbidity.We previously validated the use of wearable activity monitors (WAMs) in the peri-operative period to objectively quantify physical activity (PA) levels following breast surgery.7 WAMs have the potential to improve patient satisfaction, cost efficiency, and functional outcomes, if they are utilized appropriately.In the future, WAMs could be implemented routinely to map long-term physical recovery following breast and axillary surgery. WAMs might be used in conjunction with structured exercise regimens to enable healthcare providers to track patients’ levels of activity and offer tailored, real-time feedback depending on PA levels. WAMs can deliver behavioral signals or motivational messages to patients that encourage them to perform the prescribed exercises. As evidence begins to strengthen the relationship between PA and survivorship after breast surgery, these strategies are pertinent.


Fangcang shelter hospitals have played an important role in the battle against the COVID-19 epidemic in China. Patients’ verbal and physical attacks on medical workforce are prone to occur in such hospitals. This study explored the impacts of patient mistreatment on healthcare workers’ role behaviors .We examined the influence of patient mistreatment on service performance and patient-oriented organizational citizenship behavior, as well as the mediating effect of emotional exhaustion and the moderating effect of displaced aggression by patients, using hierarchical linear regression and conditional process analysis.Patient mistreatment was positively associated with emotional exhaustion among healthcare workers, while emotional exhaustion was negatively associated with service performance and patient-oriented organizational citizenship behavior. Mediation analysis revealed that emotional exhaustion mediated the association between patient mistreatment and both types of role behaviors. Moderated mediation analysis found that the mediation effect was weaker when the displaced aggression by patients was high.The findings clarified the relationship among patient mistreatment, emotional exhaustion, service performance, and patient-oriented organizational citizenship behavior. Additional assistance should be provided to healthcare workers dealing with patient mistreatment. Displaced aggression by patients attenuates the positive effects of patient mistreatment on the emotional exhaustion of healthcare workers. Our findings reveal the mechanism and boundary conditions of patient mistreatment affecting healthcare workers' service performance and patient-oriented organizational citizenship behavior. Workplace violence against healthcare workers has been on the rise since the COVID-19 pandemic , 3. In 2Previous studies have elaborated on the negative impact of customer mistreatment on employees, and it is important to explore the boundary conditions behind it. For example, accountability and supervisor support can weaken the impact of customer mistreatment on employees' negative emotions , 11. At Therefore, we aimed to study the impacts of patient mistreatment on the service performance and patient-oriented OCB of healthcare workers and explore the mechanisms and boundary conditions behind this relationship. This study attempted to answer the following questions: Is patient mistreatment related to service performance and patient-oriented OCB through emotional exhaustion? Can healthcare professionals perceive DAP as a protective resource to reduce emotional exhaustion?Customer mistreatment refers to unfair and low-quality interpersonal treatment of service personnel by customers during the service process, including cruel hostility, insult, and other acts of intensity less than physical violence . Walker H1: Patient mistreatment is positively associated with emotional exhaustion of healthcare workers.According to conservation of resource theory, stress results from circumstances involving threatened or actual loss of valued resources, and individuals are motivated to defend, conserve, and acquire the resources they value . Being jIn a service environment characterized by uncertainty and interdependence, employees need to go beyond the narrow scope of work to serve customers . The disH2a: Emotional exhaustion is negatively related to service performance.H2b: Emotional exhaustion is negatively related to patient-oriented OCB.Combining H1 and H2, this study proposes the following hypotheses regarding the mediating effects of emotional exhaustion:H3a: Emotional exhaustion mediates the association between patient mistreatment and service performance.H3b: Emotional exhaustion mediates the association between patient mistreatment and patient-oriented OCB.Resources are a set of important factors that can help individuals achieve their goals or meet their psychological needs . Faced wDodge et al. (1987) considered reactive aggression as an individual's defensive response to anger when confronted with frustration . DAP is H4: DAP moderates the relationship between patient mistreatment and emotional exhaustion such that the relationship is weaker when DAP is high versus low.Based on the analysis above, we attempted to incorporate displaced aggression as a boundary condition to explore ways to mitigate the negative effects of patient mistreatment. According to self-verification theory, individuals in the process of self-concept formation will continuously receive, integrate, interpret, and modify external information, thereby affecting their self-concept , 44. SelH5a: DAP moderates the indirect effect of patient mistreatment on service performance through emotional exhaustion such that the indirect effect is weaker when DAP is high versus low.H5b: DAP moderates the indirect effect of patient mistreatment on patient-oriented OCB through emotional exhaustion such that the indirect effect is weaker when DAP is high versus low.Combining H3a, H3b and H4, we propose a moderated mediation model of DAP. If the mediation hypotheses H3a, H3b and the first-stage moderation hypothesis H4 hold, it is reasonable to expect indirect effects of patient mistreatment on role behaviors through emotional exhaustion would also vary according to the different levels of DAP. Therefore, we put forward the following hypotheses:We summarize our theoretical model in Fig. https://www.wjx.cn/), with the link delivered to qualified participants with the help of medical team leaders and nursing team leaders in Fangcang Shelter Hospital in December 2022. To prevent unnecessary administrative coercion, each questionnaire was anonymized, and each IP address could only be submitted once. The sample consisted of medical and nursing staff from the Yinglong, Yutong, Yuelai, and Nanping shelter hospitals. In total, 639 questionnaires were distributed. After excluding invalid questionnaires that failed to pass the attention check, 493 valid responses were obtained. The demographic characteristics of the participants are presented in Table The online survey was administered through a questionnaire website  developed by Shao et al. (2014) . ParticiEmotional exhaustion was measured by a 6-item scale  developed by Aryee et al. (2008) . Sample Service performance was measured by a 5-item scale  developed by Bettencourt et al. (1997) . Sample Patient-oriented organizational citizenship behavior was also measured by a 5-item scale  developed by Bettencourt et al. (1997) . Sample Displaced aggression by patients was measured by a 5-item scale  developed by Denson et al. (2006) . and we Gender, age, working years, education, technical title, working weeks in shelter hospitals and daily working hours were used as covariates.Statistical analyses were conducted using SPSS 26.0 and Mplus 8.3, and descriptive statistics were computed for all variables. Considering common method variance (CMV hereafter) that might bias our findings, we introduced a variable that is completely unrelated to this study in theory as a marker variable , namely,As shown in Table We used the Harman single-factor test to assess CMV. Specifically, the results of exploratory factor analyses showed that the first principal component explained 29.47% of the variance. This value was significantly less than the 50% benchmark, suggesting no serious problems with the CMV. This study tests CMV by controlling for software self-efficacy to compare the difference between the bias correlation coefficient and its zero-order correlation coefficient . As is sr = 0.416, p < 0.001). Emotional exhaustion was negatively correlated with service performance  and patient-oriented OCB .Table p < 0.001), and emotional exhaustion was negatively associated with both service performance  and patient-oriented OCB . Thus, H1 and H2 are supported.We used hierarchical regression method to test the main effects . As showReferring to the mediation analysis steps proposed by Zhao et al. (2010) , Table 5p < 0.05).Hierarchical linear regression analysis was performed to test the moderating effect of DAP. Table Figure We further tested the moderating mediation effect on the indirect path using conditional process analysis. As shown in Table Finally, to overcome the limitation that moderated mediation can only be tested for discrete moderator values  , we usedThis study was among the first to reveal the relationship between patient mistreatment and healthcare workers’ role behaviors in the context of the Fangcang shelter hospital. The positive emotions and attitudes of healthcare workers are conducive to their work performance , 66. ExiUsing the conservation of resources theory and self-verification theory, this study demonstrated that patient mistreatment led to exhaustion of the mental resources of healthcare workers, which in turn reduced their service performance and patient-oriented OCB. This process was moderated by healthcare workers' perceived DAP. The effect of patient mistreatment on the emotional exhaustion of healthcare workers was greater, and the indirect effect of mistreatment on the two types of role behaviors via emotional exhaustion was stronger when DAP was low versus high. This study identified the pathway and boundary condition by which patient mistreatment influences service performance and patient-oriented OCB, and verified all the hypotheses of the study.Our study is consistent with previous work showing that patient mistreatment has a negative impact on emotional exhaustion in healthcare workers , 73. EmpThe present study innovatively considered a moderating variable, namely, displaced aggression by patients. Previous research on DAP has primarily focused on antecedents and outcome variables. DAP was used in this study to illustrate the boundary condition behind the link between patient mistreatment and healthcare workers’ role behaviors, emphasizing the importance of preserving their self-efficacy after perceiving DAP. It allows healthcare workers to attribute mistreatment to patient-directed blame, such as patients’ anger, depression and other negative emotions, which results in indiscriminate attacks against the staff, rather than to their own failure to meet medical service goals. From the perspective of empathy, it also explains how patient mistreatment influences service performance and patient-oriented OCB via emotional exhaustion and how this relationship changes with displaced aggression.This study has several limitations. First, self-reports were used to measure the key constructs. Studies have shown good validity of the self-report measures used in this study . HoweverIn summary, the COVID-19 has caused public panic and psychological stress. Anxiety and depressive symptoms are common psychological reactions during epidemics . PatientAlthough healthcare workers in shelter hospitals have a higher capacity of empathy, they are at 3–4 times higher risk of being infected with the virus than others because of their long-term exposure to the infected population . Lai et


Adnexal torsion due to hyperstimulation is one of the well-recognized serious complications of assisted reproductive techniques like in vitro fertilization (IVF). We report a case of a 35-year-old primigravida who presented to the emergency department with complaints of acute severe left iliac fossa pain and nausea. Further history revealed that the patient had previously undergone one cycle of ovulation induction and was diagnosed with ovarian hyperstimulation syndrome (OHSS). After prompt management, she reportedly underwent a cycle of IVF successfully. Her gestational age was five weeks and one day on presentation. A transabdominal ultrasound revealed bilateral enlarged ovaries with adequate blood supply and a single intrauterine gestational sac with a yolk sac.The patient was admitted as a case of recurrent OHSS for conservative management. Despite the initial improvement of symptoms with parenteral analgesia, an emergency laparoscopic surgery was done later due to worsening symptoms. Intraoperative findings were consistent with the suspected diagnosis of adnexal torsion which was managed accordingly. Postoperatively, the patient recovered without complications and was discharged two days later with a plan for outpatient follow-up. Adnexal torsion associated with ovarian hyperstimulation syndrome (OHSS) is an uncommon, potentially life-threatening condition with a prevalence of 0.02% in pregnancy . The exaA 35-year-old primigravida was treated with one cycle of in vitro fertilization (IVF) for primary infertility of one and a half years. She reportedly received ovarian stimulation therapy with gonadotropins followed by oocyte cryopreservation five months ago. She was subsequently diagnosed with bilateral ovarian enlargement due to hyperstimulation which was managed with a high-protein diet and cabergoline. She reportedly recovered completely as evidenced by an ultrasound scan done before embryo transfer.Her last menstrual period was seven weeks and one day prior to the presentation. A frozen embryo transfer was done on day 29 of her last menstrual cycle. Her pregnancy was confirmed with serum beta-human chorionic gonadotropin (hCG) levels two weeks later. She received three doses of hCG in the same cycle and continued aspirin, estrogen, and progesterone.The patient was on a transatlantic trip when she developed severe acute spasmodic abdominal pain in the left iliac fossa and nausea at the transit airport. She was transferred to a women’s specialty hospital after the administration of parenteral analgesia.Physical examination revealed a vitally stable, mildly dehydrated female in distress due to pain. Her body mass index (BMI) was 16.8 kg/m². Her abdomen was soft and lax with severe localized tenderness, guarding, and a palpable smooth globular mass measuring 8 cm in the left iliac fossa which was dull on percussion. Examination of all other systems was unremarkable. Lab investigations revealed serum beta-hCG levels consistent with her gestational age, elevated white blood cell (WBC) count, and low potassium levels. All biochemical tests obtained on admission are summarized in Table A transabdominal ultrasound showed bilateral enlarged multicystic ovaries measuring 10×5 cm on the right and 9×4.6 cm on the left Figures , 1B withThe patient was admitted as a case of moderate recurrent OHSS for analgesia, IV fluids, and potassium infusion, and she was kept nil per os (NPO) with regular monitoring of vital signs. Over the next few hours, her symptoms worsened despite an initial improvement with conservative management. A repeat physical examination showed the abdominal mass larger than before, measuring about 10 cm in diameter and extending to the level of the umbilicus. An emergency laparoscopic surgery was done, and the suspected diagnosis of left-sided adnexal torsion was confirmed intraoperatively Figure . The ovaThe patient recovered well postoperatively with major relief of symptoms. She was discharged two days later with a follow-up appointment in the early pregnancy assessment unit (EPAU) for further management.Ovarian hyperstimulation syndrome (OHSS) is a condition characterized by an exaggerated stimulation of the ovaries following ovulation induction during assisted reproductive technologies and rarely due to mutation of the follicle-stimulating hormone receptors . The incThe exact pathophysiology of OHSS is not widely understood but is hypothesized to be related to hCG-mediated hypersensitivity of the ovaries . This caThere are multiple, well-established risk factors for the development of OHSS, which are classified as primary and secondary. Age less than 33 years, a low BMI, high antral follicle count (AFC), anti-mullerian hormone levels, and a previous history of OHSS or polycystic ovarian syndrome (PCOS) are some of the main primary risk factors. Factors associated with ovarian response to hormonal therapy including the number of ovarian follicles on the day of hCG administration, a high absolute level or rate of serum estradiol increase, elevated inhibin-B, and vascular endothelial growth factor (VEGF) are the most reported secondary risk factors .OHSS is a clinical diagnosis with key findings of recent ovarian stimulation therapy followed by ovulation or hCG administration, symptoms of abdominal bloating, pain and nausea, decreased urine output, and a palpable abdominal mass. Pregnant women presenting with the same require an urgent transvaginal ultrasound (TVUS) scan or transabdominal scan (TAS), the imaging modality of choice in suspected cases of adnexal torsion . A unilaMost cases of OHSS are self-limiting and require only supportive treatment with outpatient follow-up. Conservative treatment with analgesia and antiemetics, fluid and electrolyte replacement, and inpatient monitoring may be required in moderate-to-severe cases of OHSS as it can lead to life-threatening complications requiring surgical management as in this case. In high-risk cases, preventive measures such as cabergoline, prophylactic albumin or high-protein diet, metformin, low-dose aspirin, and relcovaptan among other strategies can be adopted to reduce the incidence of OHSS . This paEarly surgical intervention is necessary to prevent patient morbidity including permanent ovarian damage and fetal loss associated with torsion . Direct Despite adequate treatment, the recurrence of torsion in pregnancy can be up to 19.5%, out of whom 73% conceived through assisted reproductive technologies. Seven out of 41 pregnant women had a recurrence of torsion in the same pregnancy [A history of ovulation induction therapy followed by IVF treatment, low BMI, and a previous history of OHSS were risk factors for the development of OHSS in the case presented above. Measures including prompt assessment of predisposing factors, serial ultrasound scans during ovulation induction and hormonal therapy in assisted reproductive techniques, and prophylactic cyst aspiration in confirmed cases of OHSS might reduce the prevalence of torsion and related complications. Further studies and extensive research are required to analyze the effectiveness of these management options.


Sustained chronic inflammation of the large intestine leads to tissue damage and repair, which is associated with an increased incidence of colitis-associated colorectal cancer (CAC). The genetic makeup of CAC is somewhat similar to sporadic colorectal carcinoma (sCRC), but there are differences in the sequence and timing of alterations in the carcinogenesis process. Several models have been developed to explain the development of CAC, particularly the “field cancerization” model, which proposes that chronic inflammation accelerates mutagenesis and selects for the clonal expansion of phenotypically normal, pro-tumorigenic cells. In contrast, the “Big Bang” model posits that tumorigenic clones with multiple driver gene mutations emerge spontaneously. The details of CAC tumorigenesis—and how they differ from sCRC—are not yet fully understood. In this Review, we discuss recent genetic, epigenetic, and environmental findings related to CAC pathogenesis in the past five years, with a focus on unbiased, high-resolution genetic profiling of non-dysplastic field cancerization in the context of inflammatory bowel disease (IBD). The primary driver of colorectal carcinogenesis in IBD is chronic inflammation. The two main types of IBD, Crohn’s disease and ulcerative colitis, typically begin in young adulthood and persist throughout life . EpidemiThe chronically inflamed colon can develop anatomic abnormalities such as inflammatory polyps , strictures, and eventually shortening of the colon. Although such changes have historically been considered risk factors for developing CRC, more recent analyses indicate that they may not independently predict CAC beyond the chronic inflammation that gave rise to them in the first place. One of the strongest risk factors for CAC is primary sclerosing cholangitis (PSC), a chronic inflammatory condition of the bile ducts that is found in up to 10% of patients with IBD. Individuals with IBD and concomitant PSC have a 5-9-fold increased risk of CAC compared to IBD patients without PSC . IronicaIn recent decades, the incidence of CAC has been gradually declining . This coA potential cancer chemopreventive effect of medications used to treat IBD has demonstrated mixed results . The strfield cancerization effect of chronic inflammation on large swaths of epithelial cells leads to high rates of synchronous and metachronous dysplasia. Recovery from colitis involves the development of physiologic serrated or hyperplastic mucosal epithelium, so finding serrated epithelial changes in chronic colitis may be an innocent reflection of the healing process. More research is needed to better define the potential carcinogenic role of serrated lesions in colitis especially since they are often endoscopically invisible and detected as incidental findings on random biopsy , 41TP53,ly 11.1% , 13% . Mo. Mo96]. Fusobacterium species in IBD over healthy colon, a trend which persists into both primary CRC and distant metastases [Fusobacterium species were conserved within CRC patient-derived xenograft (PDX) models, and treatment with metronidazole decreased both Fusobacterium load and PDX growth but failed to reduce xenograft growth of sterile CRC cell cultures, suggesting that on-target effect of antibiotics may slightly curtail CRC growth [In addition, metagenomic studies also identify increased tastases , 93, 97.C growth .Innate lymphoid cells (ILCs) are tissue-resident innate lymphocytes present at the intestinal mucosal barrier that regulate host-microbe interactions. Group 3 ILCs (ILC3s), which respond to microbiota in the intestines via the release of IL-17 and IL-22, were recently found using single-cell RNA-sequencing to be profoundly different in patients with colitis and CAC, with decreased population, as well as altered cellular plasticity and T cell interactions compared to controls . This isSpecifically, the authors found that ILC3 and T-cell interaction depends on major histocompatibility complex II (MHC-II) for microbiota-dependent immunity. This interaction was found to be critical for tumor growth, as deletion of MHC-II on ILC3s specifically significantly increased adenoma size and load in an AOM/DSS-induced model of CAC compared to WT mice . FurtherUC also exhibits expansion of a stromal compartment with pro-inflammatory and lymphoid signatures rarely detected in healthy colon. The cells responsible for these signatures secrete LIGHT protein and interleukin 6 (IL-6) upstream of STAT3 to modulate the immune response and format tertiary lymphoid structures in the setting of chronic inflammation . This stOur understanding of how chronic inflammation and its consequent molecular mechanisms underlying CAC tumorigenesis continues to advance. Recent high-resolution crypt-sequencing studies allowed more sophisticated observation of genetic and cell population changes in the cancerized field. Furthermore, burgeoning transcriptional and epigenetic analyses between CAC and sCRC suggest a greater divergence than once expected. It is hoped that advances in genetic, epigenetic, immunologic, and microbiological molecular mechanisms can be leveraged to identify novel target pathways for the prevention and management of CAC.Several broad, outstanding questions regarding field cancerization remain. A substantial minority of UC patients develop CAC after less than eight years following diagnosis and, conversely, the vast majority of UC patients never develop cancer, a disparity that needs to be framed in the context of both genetics and environment.Clinical epidemiologic data suggests not all inflammation appears to confer the same risk for CAC. Why does colonic inflammation result in increased cancer risk but isolated proctitis does not; is this simply a reflection of the reduced area of mucosa at risk? Why does the presence of primary sclerosing cholangitis (PSC) in someone with IBD colitis confer some of the highest risk of CAC even if colitis is minimal, whereas isolated PSC confers no additional risk? A more granular profiling of immune cell populations and inflammatory cytokines may be needed to explain these subtype paradoxes of the CAC spectrum.Perhaps most significantly, recent studies suggest shifting selective pressures that erase clones selected for during non-dysplastic colitis over the course of CAC tumorigenesis. Why do UC field cancerization mutations in the IL-17/NF-κB pathway “disappear” upon CAC formation, as opposed to mutations in other normal tissue epithelia upon aging, where they persist into their respective cancers? Do these pathways represent a previously unrecognized tumor suppressor function or are they simply outcompeted? Mechanistic experiments will provide further insight into this observation, which continues to be shaped by the continuingly increasing granularity in terms of temporality and histological context (non-dysplastic versus dysplastic versus neoplastic) in which transcriptomic, genomic, epigenomic, and metagenomic characterizations are being performed.Lastly, greater efforts should be directed towards the generation of a mouse model that more faithfully recapitulates CAC. The AOM/DSS model, while fast, simple, and cost-effective, results in genetic heterogeneity as it is a chemical model. Lesions are also polypoid and may not reflect the pathology of human disease, which are flat lesions. Genetically engineered mouse models of p53 loss in colon may be a cleaner approach, in the setting of genetically (CD4-dnTGFβRII) or chemically (DSS) induced inflammation may result in a more authentic model and should be investigated. A faithful genetically engineered mouse model (GEMM) for CAC will permit high-resolution single-cell profiling of genetic, transcriptomic, and epigenomic events for cells throughout the sequential spectrum of timing and histopathology.