Production Patterns Research Articles

Biomass competition connects individual and community scaling patterns.

Both metabolism and growth scale sublinearly with body mass across species. Ecosystems show the same sublinear scaling between production and total biomass, but ecological theory cannot reconcile the existence of these nearly identical scalings at different levels of biological organization. We attempt to solve this paradox using marine phytoplankton, connecting individual and ecosystem scalings across three orders of magnitude in body size and biomass. We find that competitive interactions determined by biomass slow metabolism in a consistent fashion across species of different sizes. These effects dominate over species-specific peculiarities, explaining why community composition does not affect respiration and production patterns. The sublinear scaling of ecosystem production thus emerges from this metabolic density-dependence that operates across species, independently of the equilibrium state or resource regime. Our findings demonstrate the connection between individual and ecosystem scalings, unifying aspects of physiology and ecology to explain why growth patterns are so strikingly similar across scales.

Climate variability links to changes in Rioja wine (Spain).

This study investigates the impact of regional climate changes on the production, quality, chemical composition, and phenological patterns of Rioja wine in Spain from 1993 to 2017. Data from DOCa Rioja and the Marqués de Riscal winery were analyzed in conjunction with meteorological and remote sensing data to provide a comprehensive evaluation. The findings reveal an increase in alcohol content and pH, coupled with a decrease in acidity, correlative to phenological shifts such as earlier grape ripening and reduced leaf canopy. Additionally, a thorough examination of monthly climate anomalies highlights the significance of May in determining harvest outcomes, influenced by the Eastern Atlantic (EA) mode of low-frequency variability. The potential connection between springtime weather conditions and tropical climate variability is also explored.

Sovereign Debt and Climate Change in Argentina – The Catalytic Role of the IMF

Abstract This article studies the interdependence between Argentina’s public over-indebtedness and climate change. It addresses the following questions: What type of productive model does the Argentine public debt profile promote, and what is its impact on climate change? In a debt-servicing scheme marked by fiscal consolidation, which strongly conditions the state budget, what public funds are available to invest in adaptation and mitigation? Finally, what is the role of the IMF in this fiscal-environmental scheme? The article first presents the international commitments of the Argentine State in the face of climate change and the estimated fiscal cost of implementing the necessary adaptation and mitigation measures. It then describes the situation of Argentina’s debt in historical perspective up to the present and explains how the external debt has been determining the productive specialization of the national economy, which seeks to boost the country’s primary export capacity, particularly agribusiness, the fossil fuel sector, and open-pit metalliferous mining. It also analyzes the role of the IMF in Argentina as a catalytic actor in the climate crisis, describing the IMF’s centrality in the national economy, its economic-environmental policy on the production pattern that accelerates climate change, and the incidence of this phenomenon in Argentina.

A quick response, but not too much: Experienced mangabeys (Cercocebus torquatus) lose interest in contact call exchanges that do not respect this "conversational rule".

Several non-human primate species engage in vocal exchanges of contact calls, throughout the day in peaceful contexts. These vocal exchanges have been compared to human conversations because vocalizations are uttered in turn-taking: a temporal pattern where interlocutors minimize silences and avoid overlaps. But observing such a pattern in the spontaneous production of a species, as is the case with red-capped mangabeys (Cercocebus torquatus), is not enough to make it a rule. Another prerequisite is that the pattern is expected by the animal. Here, we conducted a playback experiment using the violation-of-expectation paradigm to test whether captive red-capped mangabeys react differently to usual vs unusual interactive temporal patterns. We played back vocal exchanges with usual minimized response time (0.5 sec), with unusual longer response time (1.5 sec) and with unusual call overlap to 12 adult captive male mangabeys. For each individual, we measured the occurrences and durations of head orientation toward the loudspeaker after the stimuli. The interest of individuals varied according to the vocal exchange temporal pattern in interaction with their age. Indeed, the older (and thus more socially experienced) an individual was, the less interested he became after an unusual vocal exchange, i.e. a vocal exchange with call overlap or with a delayed response time. These findings suggest that experience shapes attention towards more socially relevant situations, and thus that turn-taking can be qualified as a social rule.

Conceptualizing Agrifood Systems for a Healthy, Sustainable, and Just Transformation: A Systematic Scoping Review

Human and planetary health are interconnected through food and agriculture. Food production and consumption patterns continue to drive the global burden of malnutrition, diet-related disease, climate change, and environmental degradation. There is an urgent need to identify pathways for transforming agrifood systems to be increasingly healthy, sustainable, and just, but conceptual frameworks necessary for visualizing these complex relationships are limited. This systematic scoping review identified existing frameworks for analyzing human and environmental outcomes of agrifood systems and evaluated their inclusion of policy and governance. Frameworks have evolved to increasingly consider the food supply chain activities and actors, the drivers that shape them, and the outcomes of these interactions. The findings of the review were used to develop a conceptual framework specific to modern industrialized agrifood systems where policy landscape is an explicit component. The framework is tailored to researchers and policymakers with the intention of providing a foundation for analyzing and communicating agrifood system issues, including identifying facilitators and barriers to effective policy, places to intervene in the system, and windows of opportunity for successful transformation.

Bibliometric Analysis of Spline Regression Model for Trend Mapping and Strategy Development Research Using Vosviewer

Bibliometric analysis is a quantitative method used to measure and analyze scientific literature. This technique involves the collection and analysis of publication data, such as journal articles, books, and conferences, to evaluate and understand patterns of scientific communication, research productivity, author collaboration, journal impact, and trends within a scientific field. Bibliometric analysis has a limitation in that it is challenging to visualize effectively, necessitating the use of software for proper visualization. Therefore, this article discusses bibliometric analysis on spline regression for trend mapping and strategy development using VOSviewer software. The research results show that the visualization of spline regression keywords with VOSviewer can help in understanding patterns of relationships between variables, research trends, and network structures in scientific literature. Based on the analysis results, bibliometric analysis on spline regression can be visualized in trend mapping, which can aid in planning further research strategies, including identifying collaboration opportunities and underexplored research areas.

Numerical simulation of strengthening/deterioration and damage development of cementitious materials under sulfate attack environment

Cementitious materials exposed to sulfate environments often suffer from the combined effects of external sulfate attack and dry wet cycling. In order to predict the long-term performance of cement-based materials in sulfur rich environments, this paper aims to establish a numerical model that can reasonably characterize the degradation process of cementitious materials in sulfate environments. Using this model, we can address durability problems common to cementitious materials in real sulphate environments, such as determining the degree of corrosion, predicting the durability life of materials, and calculating the time to failure. The model consists of three parts: transportation, chemical reactions, and material damage. We establish the degradation model for cement-based materials in sulfate environments by considering ion diffusion, water convection, chemical reactions, accumulation of corrosion products, and the development of material strengthening/degradation. Compared with existing sulfate corrosion models, this model not only considers ettringite, but also takes into account the volume changes of gypsum formation, calcium leaching, and salt crystallization precipitation, which can more reasonably simulate the sulfate corrosion process in real environments. The model can reasonably simulate the distribution pattern of ion concentration, hydration products and corrosion products in the cementitious material, and on this basis calculate the porosity of the cementitious material. In order to make the simulation results more applicable to experimental and non-destructive testing results, the model uses easily obtainable relative dynamic elastic modulus to evaluate the degree of material strengthening/degradation and predict the durability life of the material.

A strategic and social analytics model for sustainable packaging in the cosmetic industry

Every day, we use cosmetic products that are not only focused on beauty but also with everything related to personal care and hygiene. The impact that these products have on sustainability cannot be overlooked. Many cosmetics contain unsustainable ingredients that can cause environmental damage and loss of biodiversity. In addition, fossil-based packaging contributes greatly to environmental pollution and increases waste in the absence of a circular supply chain. This work has a dual objective. The first is to provide a strategic analysis based on a multi-criteria approach to evaluate the most sustainable alternatives to traditional packaging that manufacturers could adopt based on the opinions of experts from different categories of stakeholders. In this study, the multi-criteria approach was employed, as it has been widely recognized in the literature for its effectiveness in evaluating and comparing alternatives across multiple, often conflicting criteria. The second is to provide a social analysis to assess consumers’ views, habits, preferences, and willingness to pay toward sustainable packaging. The results show divergence among experts who prefer refillable packaging while consumers prefer recyclable packaging. In contrast, a convergence in selling price and production costs is verified, highlighting the strategic importance of the economic dimension is for sustainable packaging, and the willingness to pay for sustainable packaging is about twice that of traditional packaging. The implications of this work suggest that circular supply chains covering the entire life cycle of products, based on a pragmatic approach, can drive the convergence of consumption and production patterns toward sustainable development.

Potential Conflict Diagnosis, Simulation Optimization and Coordination of Production-Living-Ecological Space in Gully Areas of the Loess Plateau, China

The gully areas on the Loess Plateau have always been ecologically fragile agricultural areas. These areas often face the common problem of intensified conflicts in production-living-ecological space during economic development, and there is an urgent need for systematic spatial governance. This study innovatively developed a full process technical framework of "identification diagnosis - simulation optimization - coordinated governance" for potential conflicts in the production-living-ecological space, and used Huachi County in the gully area of the Loess Plateau as an example for empirical research. Under this framework, we analyzed the transfer patterns of production, living, and ecological space in the research area; Improved the spatial suitability evaluation index system of "multi-dimensional + multi-objective"; The conflict determination matrix was used to identify the scope, scale, type, and intensity of potential spatial conflicts; We conducted spatial optimization simulations under two scenarios: prioritizing ecological protection and prioritizing social and livelihood development, and designed an overall spatial optimization plan; Propose spatial collaborative governance strategies based on the theory of public space governance. Research shows that this framework has good applicability for the research area and is more direct for guiding subsequent spatial planning and policy practice. The potential conflict between production space and ecological space in Huachi County is the most common, the potential conflict intensity between living space and production space is the largest, and the potential conflict risk between living space and ecological space is rising. To coordinate potential conflicts in space, it is necessary to establish a vertical allocation type of spatial function coordination chain of “goal + collaboration + adjustment”, as well as a horizontal negotiation type of spatial configuration coordination chain of “allocation + cooperation + balance”, forming a “double vertical and double horizontal” spatial coordination framework.

Linguistic, Metalinguistic and Psychiatric Characteristics of Children with Speech Sound Disorder

Abstract: Comparing the linguistic and metalinguistic profiles in common developmental speech and language disorders is important in advancing our understanding of their clinical symptoms, as well as potentially informing the conceptual basis of novel interventions. The purpose of the present review article is summarizing linguistic, metalinguistic and psychiatric characteristics of children with speech sound disorder (SSD). Clinically and theoretically, it is important that we can understand different error pattern uses among children with SSD only and children with co-occurring SSD and language impairment (LI). Identifying differences in error pattern use will help to discovering the underlying causes of the different types of patterns. In comparison with children with SSD, children with co-occurring SSD and LI use certain patterns more frequently that suggest more global linguistic deficits. The early identification of children who are at risk for development of co-occurring SSD and LI as well as later literacy problems needs to distinguish these patterns. Identification of speech error patterns and their underlying cognitive-linguistic processing deficits will contribute to diagnosis of children at risk of co-occurring SSD and LI and reading problems. Mounting studies have reported that children with SSD, with and without language impairment have differences in phonological processing, literacy skills, and speech production patterns. Children with both speech sound and language disorders are likely to have more severe literacy problems than those with isolated speech sound disorders. In addition, this paper focuses on the comorbidity between psychiatric disorders specially attention deficit/hyperactivity disorder (ADHD) symptoms and SSD.

A Bibliometric Analysis of Ten Years on Positive Psychology in Foreign/Second Language Education (2012-2022)

This bibliometric study examines the research trends, productivity, publication, and citation patterns of positive psychology in the field of foreign/second language education by analyzing 137 documents retrieved from the Web of Science (WoS) database between 2012-2022. Data analysis was conducted using various scientometric software, including MS Excel and Biblioshiny. Results reveal that the first publication on this topic appeared in 2012, with a major increase observed in 2021-2022, with the highest number of publications (N = 41) in 2022. The highest number of citations (n = 528) were observed in 2018. China was found to be the most productive country (N = 106), while Japan had the highest citation impact (N = 63). The most cited document received 198 citations. The study also found that the most frequently used word was "emotion" and the trending topic was positive psychology. The most productive university affiliation was found to be Birkbeck University of London in the UK.

Mapping the Frontier: A Bibliometric Analysis of AI in Tertiary Education

This article presents a bibliometric analysis of research on artificial intelligence (AI) applications in higher education over the past decade. Through computer-assisted analysis of 412 documents from the Web of Science core collection, we shed light on publication trends, productivity patterns, and conceptual development. Despite this exponential growth in research output, there remains significant uncertainty about the long-term impact of AI on pedagogical practices, learning outcomes, and the overall structure of higher education systems. The results show an annual production increase of 31.8% in research publications on AI in higher education, signaling scientific recognition of the disruptive potential. The concentration in renowned specialist journals on the topic of technology-supported learning is offset by the distribution of these journals across 206 multidisciplinary sources. With 10 publications, the Chinese University of Hong Kong is the leading contributing institution. China leads in the number of publications on AI in higher education, with 62 articles, followed by the United States with 45 and the United Kingdom with 29. These regional anchors are driving progress in the field. Although there is strong collaboration, the research output remains spread across 1,182 scientists without established leaders, reflecting the diverse and emerging nature of the field. Topic modeling and keyword analysis mean an increasing examination of the connections to education systems, training, labor markets, and learning analyses. This highlights the tensions surrounding data ethics, academic integrity, and the disruption of the workforce as algorithms permeate admissions, advising, and teaching. Our examination of the anatomy of this rapidly growing field provides indispensable perspectives for guiding innovation. As techniques advance from theory to reality, continued empirical research to explore risks and opportunities will be critical to upholding humanistic educational values.

Food systems in protracted crises: examining indigenous food sovereignty amid de-development in Kashmir.

How do protracted crises shape indigenous food systems, and what are their ramifications for food and nutritional security? Building on decolonial and interdisciplinary research approaches, this paper assesses the consequences of militarised violence for Kashmir's food system. We document the impact of settler-colonialism and conflict-induced agrarian changes on delocalisation of diets. The protracted nature of the crises has two key implications for changes in dietary patterns. First, land control over common land dispossesses the local population and hinders food production. Second, disenfranchisement from (agricultural) land has led to increased reliance on markets that are flooded by imported foods as local production declines. The paper argues that the state plays an important role in food system changes by destroying local patterns of food production and consumption. Slow violence and agrarian de-development serve as tools to de-develop the local food system. Indigenous food cultures form part of everyday resistance and resilience that are operationalised as mitigation and adaptation strategies to address food insecurity.

Cyclooxygenase-2/prostaglandin E2 pathway orchestrates the replication of infectious bronchitis virus in chicken tracheal explants

ABSTRACT In this study, we investigated the localized pathogenesis of infectious bronchitis virus (IBV) in chicken tracheal organ cultures (TOCs), focusing on the role of inducible cyclooxygenase (COX-2). Two divergent IBV strains, respiratory Connecticut (Conn) A5968 and nephropathogenic Delmarva (DMV)/1639, were studied at 6, 12, 24, and 48 hours post-infection (hpi). Various treatments including exogenous prostaglandin (PGE)2, a selective COX-2 antagonist (SC-236), and inhibitors of PGE2 receptors and Janus kinase (JAK) were administered. IBV genome load and antigen expression were quantified using real-time quantitative PCR and immunohistochemistry. COX-2, interferon (IFN)-α, IFN-β, interleukin (IL)−1β, IL-6, and inducible nitric oxide synthase (iNOS) expressions were measured, along with PGE2 and COX-2 concentrations. IBV genome load and protein expression peaked at 12 and 24 hpi, respectively. Conn A5968-infected TOCs exhibited continuous COX-2 expression for up to 24 hpi, extended PGE2 production up to 48 hpi, and reduced inflammatory cytokine expression. In contrast, DMV/1639-infected TOCs displayed heightened inflammatory cytokine expression, brief COX-2 expression, and PGE2 production. Treatment with IFN-γ, SC-236, PGE2 receptor inhibitors, or JAK inhibitors reduced IBV infection and lesion scores, whereas exogenous PGE2 or IFN-γ pretreatment with a JAK-2 inhibitor augmented infection. These findings shed light on the innate immune regulation of IBV infection in the trachea, highlighting the involvement of the COX-2/PGE2 pathway. IMPORTANCE Understanding the localized pathogenesis of infectious bronchitis virus (IBV) within the trachea of chickens is crucial for developing effective control strategies against this prevalent poultry pathogen. This study sheds light on the role of inducible cyclooxygenase (COX-2) and prostaglandin (PGE)2 in IBV pathogenesis using chicken tracheal organ culture (TOC) models. The findings reveal distinct patterns of COX-2 expression, PGE2 production, and immune responses associated with different IBV strains, highlighting the complexity of host-virus interactions. Furthermore, the identification of specific inhibitors targeting the COX-2/PGE2 pathway and Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway provides potential therapeutic avenues for mitigating IBV infection in poultry. Overall, this study contributes to our understanding of the innate immune regulation of IBV infection within the trachea, laying the groundwork for the development of targeted interventions to control IBV outbreaks in poultry populations.

Spatiotemporal distribution of sedimentary chloropigments and organic carbon in a shelf sea ecosystem, with a focus on the cold water mass

The Yellow Sea is one of the most thoroughly studied shelf seas in the northwestern Pacific. However, many aspects of the northern Yellow Sea sediments remain poorly understood. Sedimentary chloropigments and total organic carbon (TOC) are crucial components that indicate benthic primary productivity and ecosystem functioning in the marginal sea system. The present study investigated the temporal and spatial variations of sediment chloroplastic pigments (Chl-a and Pha-a) and TOC contents in relation to seasons and the northern Yellow Sea Cold Water Mass (NYSCWM). Decadal trends were also examined using linear regression on time-series data from 12 cruises conducted over a nine-year period (2006–2014). The correlations between sedimentary Chorophy-a (Chl-a), Pheophorbide-a (Pha-a), TOC, and their ratios with other abiotic and biotic factors were analyzed to detect any effects of the NYSCWM on the spatiotemporal distribution of sediment Chl-a, Pha-a, TOC contents, as well as the ecological relevance of their ratios as indicators of food quality (freshness) in the benthic system. The NYSCWM substantially influences the spatial and seasonal distribution of sedimentary Chl-a, Pha-a, and TOC contents. High values of Pha-a, TOC, and the ratios of Pha-a/(Chl-a + Pha-a) and TOC/Chl-a were often observed in the central region of the NYSCWM, where Chl-a showed clear seasonal fluctuations while Pha-a and TOC remained relatively constant. While sedimentary TOC appears to negatively mirror the spatial pattern of primary productivity in the water column, the spatial pattern of sedimentary Chl-a in relation to NYSCWM is less evident. However, the contents of Pha-a and TOC in the central NYSCWM sediments were higher than those at surrounding NYSCWM stations. Surface sediment Pha-a/(Chl-a + Pha-a) ratio was negatively correlated with meiofauna abundance and biomass and positively correlated with nematode/copepod ratio. This finding indicates that the quality of sediment organic matter is important to meiofauna. Conversely, the lower organic degradation rate at the lower bottom temperature of the NYSCWM may explain the observed higher Pha-a and TOC contents in its central area. Time-series data collected over nine years at the NYSCWM stations showed a decreasing trend for Chl-a, while TOC and the ratio of Pha-a/(Chl-a + Pha-a) exhibited increasing tendencies. This trend may imply a reduced quality of food supply to the benthic food web in the shelf sea system, along with degraded ecosystem functioning and service under the impacts of global change and anthropogenic disturbances.

Experimental and molecular dynamics study on combustion characteristics of non-stick coal

To investigate the combustion characteristics of non-stick coal and the formation patterns of main combustion products and radicals, this study initially conducted a TG-DSC experiment of non-stick coal. Subsequently, non-stick coal was characterized and analyzed using XPS and 13C NMR experiments, and a molecular model with the formula C208H199O23N3S was constructed. Subsequently, the ReaxFF MD method was employed to simulate the combustion molecular dynamics of the non-stick coal periodic mixing model under varying oxygen content and temperature conditions. The analysis focused on elucidating the formation patterns of free and primary products during combustion. Experimental findings indicate that the combustion of non-stick coal progresses through stages, including water evaporation and desorption (30–145.65 °C), dynamic equilibrium (145.65–181.76 °C), oxygen weight gain (181.76–263.56 °C), thermal decomposition (263.56–379.14 °C), combustion (379.14–562.04 °C) and burnout (562.04–800 °C). The ignition temperature of non-stick coal was determined to be 379.14 °C. The simulation results indicate that an increase in temperature and oxygen content further enhances the relatively stable peak production of CO2. The peak increase of CO production is weaker than that of CO2. The rise in temperature also promotes the formation of H2O, while the increase in oxygen content initially enhances and subsequently inhibits the peak production of H2O. H radicals, O radicals, and OH radicals are primarily generated through the decomposition reactions of small molecular compounds or other free radicals. Free radical polymerization and the decomposition of small molecular compounds represent the primary pathways for the formation of CO, CO2, and H2O.

Climatic and edaphic controls of root-tip production and mortality in five temperate tree species

Root tips are the main components of absorptive fine roots, but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology. In this study, we explored the temporal patterns of root-tip production and mortality in monoculture plantations of five temperate tree species at a common site in northeastern China, and identified the general environmental controls on such processes. We made monthly in-situ assessments of root tip length (RTL) production and mortality in two hardwood and three coniferous species with a minirhizotron (MR) method during the growing seasons of 2008 and 2009. Air temperature, rainfall, soil temperature and water content at 10 cm depth were determined concurrently. RTL production in all species exhibited consistent peaks in summer (June–August) in two growing seasons. RTL mortality showed substantial interannual and interspecific variability, with peaks in autumn and winter in 2008, but various patterns in 2009. RTL production positively correlated with monthly soil and air temperature across all species, and with monthly rainfall in three coniferous species. However, there was no significant correlation between RTL production and soil water content. By contrast, RTL mortality was weakly related to environmental factors, showing positive correlations with soil temperature in Korean spruce, and with rainfall in Korean pine and Korean spruce. Our findings suggest that the seasonal patterns of RTL production are convergent across the five temperate tree species due to the overlapped distribution of heat and rainfall, which can conduce roots to maximizing the acquisition of nutrient resources in the soil.

Enhancing Burning Rate of Ammonium Nitrate by Ammonia Borane: Mechanism from Reactive Molecular Dynamics Simulation.

The development of ammonium nitrate (AN)/ammonia borane (AB) as a green propellant is crucial for their applicability in different engines. This study investigates the release patterns of small products, particularly nitrogen-containing molecules, during the initial pyrolysis of AN/AB at low and high pressures using ReaxFF MD simulations. Compared with pure AN, the addition of AB gives the hybrid system enhanced reactivity, leading to faster decomposition and higher energy release. The results show that the consumption of AN in the S13 system (AB with a mass ratio of 12.6 %) is accelerated at 1.47 MPa. NO2 and NO are produced through HNO3 and NO3. At 6.89 MPa, AN exhibits the fastest decomposition rate in the S15 system. The high pressure enhances more reactions of NO with free radicals such as NH and accelerates the release of N2. As the percentage content of AB increases to 15.3 %, more H2O while more NO2 is generated. The effect of AB on the generation of radicals such as H2 and H, is analyzed. AB not only promotes the initial pyrolysis of AN but also accelerates the conversion of intermediates.

A behavioural theory of trade

ABSTRACT Inspired by the psychology of creativity, we explore a new cause of trade with a behavioural trade model which predicts several trade patterns supported by new empirical evidence. The model examines the effects of human creative orientation on production, consumption, and trade patterns, thus shedding new light on the gains and losses from trade. It predicts that countries with higher levels of household creative orientation are more inclined to export creative goods. This prediction is supported by empirical evidence using a gravity model with data from the European Social Survey.

Toronto Heritage Italian (r): Maintaining homeland patterns

Contrary to experimental research, comparative variationist approaches find for heritage speakers many cases of maintenance of the homeland grammar. We analyze patterns of rhotic production in spontaneous speech of the heritage Calabrese Italian community of Toronto, Canada, and its homeland counterpart in Calabria, Italy. 1,555 tokens of word-internal, singleton /r/ were collected from the HLVC corpus and analyzed using mixed-effects models. Results show an ongoing pattern of lenition for both homeland and heritage speakers. Heritage speakers further develop this language internal trend, indicating grammar boosting. Homeland social constraints are maintained by heritage speakers. We find no evidence of transfer from English or simplification in the heritage language. Similar patterns of rhotic lenition are found in heritage Tagalog (Umbal & Nagy 2021) and Russian (Nagy 2024), though with different social constraints. Cross-linguistic comparison proves that variation in heritage languages is not necessarily caused by contact, and that change needn’t be related to indexicality.