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A quantitative classification of the geography of non-native flora in the United States
No full textAim: Non-native plants have the potential to harm ecosystems. Harm is classically related to their distribution and abundance, but this geographical information is often unknown. Here, we assess geographical commonness as a potential indicator of invasive status for non-native flora in the United States. Geographical commonness could inform invasion risk assessments across species and ecoregions.
Location Conterminous United States
Time period Through 2022
Major taxa studied Plants
Methods: We compiled and standardized occurrence and abundance data from 14 spatial datasets and used this information to categorize non-native species as uncommon or common based on three dimensions of commonness: area of occupancy, habitat breadth, and local abundance. To assess consistency in existing categorizations, we compared commonness to invasive status in the United States. We identified species with higher-than-expected abundance relative to their occupancy, habitat breadth, or residence time. We calculated non-native plant richness within United States ecoregions and estimated unreported species based on rarefaction/extrapolation curves.
Results: This comprehensive database identified 1874 non-native plant species recorded in 4,844,963 locations. Of these, 1221 species were locally abundant (>10% cover) in 797,759 unique locations. 1101 non-native species (59%) achieved at least one dimension of commonness, including 565 species that achieved all three. Species with longer residence times tended to meet more dimensions of commonness. We identified 132 species with higher-than-expected abundance. Ecoregions in the central United States have the largest estimated numbers of unreported, abundant non-native plants.
Main conclusions: A high proportion of non-native species have become common in the United States. However, existing categorizations of invasive species are not always consistent with species’ abundance and distribution, even after considering residence time. Considering geographical commonness and higher-than-expected abundance revealed in this new dataset could support more consistent and proactive identification of invasive plants and lead to more efficient management practices
Evaluate the stability of synthesized allicin and its reactivity with endogenous compounds in garlic
No full textThe study aimed to prepare allicin in large quantities and evaluate the effects of different conditions and endogenous substances (polyphenols and free amino acids) in garlic on its stability. The optimized synthesis conditions of allicin (DADS:HAc = 2:9, H2O2:DADS = 2:1.6, reacted for 6.5 h) were established based on response surface design. Allicin with 92.57% purity was obtained by high-speed counter-current chromatography. The results of allicin degradation experiment indicated that the degradation rate of allicin accelerated with the increases of initial concentration and temperature, the degradation process of allicin was good fit with two first-order kinetics (R2 > 0.97). The stability of allicin was higher in pH 2–5.8 than in pH 8–9. Apigenin, myricetin, and quercetin combined with peroxidase enhanced the stability of allicin. Cysteine, arginine, and histidine could react with allicin. These findings provide insights for optimizing for allicin storage and food processing applications
Abca4, mutated in Stargardt disease, is required for structural integrity of cone outer segments
No full textStargardt disease (STGD), the leading cause of inherited childhood blindness, is primarily caused by mutations in the ABCA4 gene; yet, the underlying mechanisms of photoreceptor degeneration remain elusive, partly due to limitations in existing animal disease models. To expand our understanding, we mutated the human ABCA4 paralogues abca4a and abca4b in zebrafish, which has a cone-rich retina. Our study unveiled striking dysmorphology and elongation of cone outer segments (COS) in abca4a;abca4b double mutants, alongside reduced phagocytosis by the retinal pigmented epithelium (RPE). We report that zebrafish Abca4 protein forms a distinctive stripe along the length of COS, suggesting a potential structural role. We further show that, in wild-type zebrafish, outer segments of cone cells constitutively present externalized phosphatidylserine, an apoptotic ‘eat-me’ signal, and that this pattern is disrupted in abca4a;abca4b double mutants, potentially contributing to reduced RPE phagocytic activity. More broadly, constitutive presentation of the ‘eat-me’ signal by COS − if conserved in humans – might have important implications for other retinal degenerative diseases, including age-related macular degeneration. Our zebrafish model provides novel insights into cone dysfunction and presents a promising platform for unraveling the mechanisms of STGD pathogenesis and advancing therapeutic interventions
Generics and Quantified Generalizations: Asymmetry Effects and Strategic Communicators
Get PDFGeneric statements (‘Tigers have stripes’) are pervasive and developmentally early-emerging modes of generalization with a distinctive linguistic profile. Previous experimental work suggests that generics display a unique asymmetry between the prevalence levels required to accept them and the prevalence levels typically implied by their use. This asymmetry effect is thought to have serious social consequences: if speakers use socially problematic generics based on prevalence levels that are systematically lower than what is typically inferred by their recipients, then using generics will likely exacerbate social stereotypes and biases. This paper presents evidence against the popular hypothesis that this asymmetry effect is unique to generics. Correcting for various shortcomings of previous studies, we found a generalized asymmetry effect across generics and various kinds of explicitly quantified statements (‘most’, ‘some’, ‘typically’, ‘usually’). In addition, to better understand the conditions under which generalized asymmetry effects may exacerbate biases, we examine whether speakers choose generalizing sentences based simply on their acceptance conditions, or are systematically sensitive to the implications likely drawn by their typical recipients. In support of the latter view, we found that, in neutral or cooperative scenarios, speakers reliably choose generalizing sentences whose implied prevalence levels closely match the actual ones. In non-cooperative scenarios, many speakers exploit asymmetry effects to further their own goals by choosing generalizing sentences that are strictly true but likely to mislead their recipients. These results refine our understanding of the source of asymmetry effects and the conditions under which they may introduce biased beliefs into social networks
Kill Two Birds with One Stone: How to Enhance Animal Welfare and Tourist Experience Simultaneously in Wildlife Tourism – An Exploratory Case Study Based on Chengdu Research Base of Giant Panda Breeding
No full textWildlife tourism faces a tension between animal welfare and tourist experience. This study, based on the Chengdu Research Base of Giant Panda Breeding, uses a longitudinal single-case study approach to explore how wildlife tourism attractions can simultaneously enhance animal welfare and tourist experience through management transformation. The findings are as follows: (1) The contradiction between animal welfare and tourist experience is primarily manifested in “embodied obstacles”; (2) Synergistic enhancement arises from resolving these obstacles through “scene transformation-conceptual transformation-practical transformation,” guided by the logic of “environmental enhancement-value bonding-interest embedding”; (3) Wildlife tourism should integrate animal welfare and tourist experience by embedding ecological protection and tourism development values to ensure sustainability and enhance both ethical and experiential dimensions. This study contributes to the ethical understanding of wildlife tourism experiences, expands embodied experience theory, and provides insights for optimizing experience design and promoting the sustainable development of wildlife tourism
Bridging the gender gap in leisure travel: A feminist netnography
No full textThis study investigates the persistent gendered labor inequities in leisure travel, with a particular emphasis on heterosexual family vacations. Drawing upon feminist theory and prior scholarship on leisure inequality, it interrogates how patriarchal structures perpetuate constraints on women’s access to leisure, especially for mothers disproportionately burdened with childcare and domestic responsibilities. Employing a feminist netnographic methodology, the research analyzes online communities centered on parenting, gender, and travel to explore the division of labor in planning, executing, and recuperating from family travel. Preliminary findings suggest that women in these contexts frequently encounter inequitable labor distributions during vacations, mirroring broader domestic inequalities and impeding their ability to experience leisure as a space for recovery and well-being. However, the study also identifies potential mitigative strategies, such as shared travel with other mothers, which may alleviate some constraints. These findings underscore the urgency of addressing structural barriers to women’s leisure, with implications for advancing gender equity and enhancing well-being within family and societal contexts
Sustainable cuisine: Determinants for utilizing local food in rural tourism
No full textAs one of the world's largest and most rapidly growing industries, the travel industry is committed to enhancing sustainability in the context of travel. The usage of regional products in rural destinations has the potential to make a substantial contribution to this objective, not only from an ecological standpoint but also from an economic and social perspective. This qualitative study analyses hotels in Northern Italy and focuses on the factors influencing decision-makers' perceptions for utilizing regional food in hotel kitchens. The preliminary findings of this study indicate that social aspects are a primary determinant in the decision to obtain regional food products. This is evidenced by the tendency of decision-makers to support their friends, family members and individuals with whom they have a personal connection. However, complex supply chains, limited food availability, and seasonal variations bring pragmatic choices of the decision makers in hotels. For this reason, hotels consistently demonstrate a preference for wholesalers over regional food producers. Theoretical contributions as well as implications for practice are derived to increase the utilization of local food in rural tourism on a long run
The Art and Science of the Visual: Optimizing AI-Generated Images for Destination Marketing
No full textThe rapid advancement of generative artificial intelligence (GAI) is transforming tourism by enabling the creation of high-quality visual content for destination marketing. While text-based GAI applications are well-studied, the potential of visual-based GAI remains underexplored. This research examines how Destination Marketing Organizations (DMOs) can leverage AI-generated images to enhance destination appeal, using a multi-method approach that combines experiments, deep learning, and big data analysis. Grounded in information processing fluency theory and the destination imagery model, the study reveals that AI-generated visuals are particularly effective for promoting unfamiliar destinations compared to familiar ones. Furthermore, the findings uncover an inverted U-shaped relationship between the consistency of tourists' organic destination image and the perceived attractiveness of AI-generated visuals. These insights provide DMOs with a data-driven framework to optimize the use of AI-generated imagery, enhance marketing effectiveness, and craft compelling visuals that inspire travel interest
Analysis of parametric nonlinear eigenvalue problems: parametric holomorphy and uncertainty quantification
No full textThe study of parametric partial differential equations (parametric PDEs) has significant practical importance. Given the significance of eigenvalue problems in quantum mechanics, investigating parametric eigenvalue problems is particularly important. Despite their importance, theoretical analyses for parametric nonlinear eigenvalue problems remain insufficiently explored. This thesis, particularly motivated from the application of deep operator networks(DeepONet), focuses on a critical aspect of parametric nonlinear eigenvalue problems: the holomorphic dependence of the ground eigenpair on parameters. This holomorphic dependence provides theoretical justification for employing DeepONet to efficiently solve parametric PDEs avoiding the curse of dimensionality. This thesis is organized into five chapters. The first chapter provided the introduction and the motivations of this research. The second chapter provides a novel framework for establishing parametric holomorphy in the PDE setting which is desired the DeepONet application. Using results from Chapter 2, the third chapter demonstrates the parametric holomorphy of the ground eigenpair for linear eigenvalue problems. The fourth chapter investigates parametric holomorphy in nonlinear eigenvalue problems. Lastly, Chapter 5 discusses applications to quasi-Monte Carlo methods.Partial support from NSF under award DMS-2107934.Doctor of Philosophy (Ph.D.
A Systematic Literature Review on Gamification for Cultural Heritage Dissemination, Valorization and Sustainable Tourism Practices.
No full textCultural heritage destinations face growing challenges from mass tourism, often undermining both heritage sites and visitor experience. Gamification has emerged as an innovative strategy in tourism and heritage sectors, employing immersive technologies to engage audiences and enhance the dissemination of cultural heritage. This systematic literature review investigates the role of gamification in promoting sustainable tourism practices in European cultural destinations. While existing research highlights gamification’s potential to engage users, limited attention has been paid to its long-term impact on attitudes and behaviors related to cultural heritage. This study synthesizes existing literature to explore whether gamified experiences foster stronger connections between tourists and destinations, encouraging cultural awareness, responsible tourism, and repeat visitation. By analyzing trends, best practices, and gaps in gamification applications, the review aims to assess their influence on attitudinal and behavioral change. Findings will provide valuable insights to guide future research and inform practical applications in cultural heritage tourism