Discontinuity Concept Research Articles

Agent-based simulation model of micro-mobility trips in heterogeneous and perceived unsafe road environments

Safety concerns expressed by micro-mobility users seem to practically constrain the use and flexibility of these new modes. This paper introduces a new, parametric agent-based modeling approach for simulating micro-mobility, using MATSim as a platform. Perceived safety is introduced as a factor, which affects travel behavior of micro-mobility modes in a car-dominated, heterogeneous, and perceived unsafe road network. To meet the research objectives, different scenarios are simulated, using the city of Athens, Greece as a test bed, to examine the model performance and applicability. A universal scoring function based on travel time, cost, and safety, is proposed. This study also discusses the concept of unsafe discontinuities. Simulation results show that an unsafe road segment of 500 m long is sufficient to induce evident behavioral variations and hinder the practical use of e-bikes and e-scooters in the base scenario. The establishment of a cycle-friendly road network leads to significant changes in the chosen routes and decreases the average trip distance for micro-mobility users. In this case, the simulation process is guided by perceived safety, primarily focusing on formulating safer paths for micro-mobility mode users. Nevertheless, the routing behavior of car users is not modified due to the spatial uniformity of safety perceptions in a car-dominated road environment.

Continuity and Discontinuity in Cultural Conditioning Ruth Benedict

In our culture, the human growth cycle is a constant, from vulnerable infants to adults. Ruth Benedict underscores the physiological contrast between the two, as well as the roles that change over time. While these facts of nature underlie discussions of humans, the anthropologist's role is to analyze the interaction between "nature" and human behavior, and how culture influences it. In this context, Benedict highlights the concepts of continuity and discontinuity, describing variations in child training in different cultures and differences in roles between children and adults. She points out that although physiological differences exist, the process of transitioning from child to adult varies significantly between societies. In her paper, Benedict analyzes three contracts that are prominent in culture, namely non-responsive responsible status, compliance dominance, and limited sexual roles. This research helps to understand how culture plays an important role in the formation of the human life cycle, highlighting the continuities and discontinuities that exist across different cultures.

Extended N-centered ensemble density functional theory of double electronic excitations.

A recent work (arXiv:2401.04685) has merged N-centered ensembles of neutral and charged electronic ground states with ensembles of neutral ground and excited states, thus providing a general and in-principle exact (so-called extended N-centered) ensemble density functional theory of neutral and charged electronic excitations. This formalism made it possible to revisit the concept of density-functional derivative discontinuity, in the particular case of single excitations from the highest occupied Kohn-Sham (KS) molecular orbital, without invoking the usual "asymptotic behavior of the density" argument. In this work, we address a broader class of excitations, with a particular focus on double excitations. An exact implementation of the theory is presented for the two-electron Hubbard dimer model. A thorough comparison of the true physical ground- and excited-state electronic structures with that of the fictitious ensemble density-functional KS system is also presented. Depending on the choice of the density-functional ensemble as well as the asymmetry of the dimer and the correlation strength, an inversion of states can be observed. In some other cases, the strong mixture of KS states within the true physical system makes the assignment "single excitation" or "double excitation" irrelevant.

Longitudinal changes on ecological diversity of Neotropical fish along a 1700 km river gradient show declines induced by dams

In naturally flowing waters, communities are expected to increase their taxonomic and functional diversity as well as increase the complexity of food web architecture along the longitudinal gradient from headwaters to mouth. However, these theories do not necessarily apply to dammed rivers. We analysed fish communities at 12 locations along the 1700 km stretch of the transnational Uruguay River. We determined species richness, beta-diversity and its components (turnover and nestedness), trophic diversity, and isotopic niches at community level, with particular focus on areas upstream and downstream of the four existing dams. We estimated trophic diversity metrics based on diet analysis, and isotopic niche breadth based on Bayesian isotopic niche models. We detected consistent longitudinal changes, supporting predictions from the River Continuum Concept. However, taxonomic richness, trophic diversity, and isotopic niche decreased abruptly immediately downstream of dams, and the component contributing the most to beta diversity was turnover, with the highest values occurring mainly after the cascade of dams in the upper Uruguay River, fitting expectations from the Serial Discontinuity Concept. The dam-free stretches of the Uruguay River allowed the recovery of ecological diversity as fish richness and trophic and isotopic niche increased. The negative impacts of dams should urgently be considered in the Neotropics, where many large dams are projected.

Phytoplankton species composition as bioindicator in the largest fragmented channel of the Pearl River, China.

To test the serial discontinuity concept (SDC) predictions in a regulated river ecosystem, environmental parameters and phytoplankton community structure were determined in a subtropical river (China) which was regulated by 11 cascade dams. Our results showed that total phosphorus (TP) and silicate during the wet period in several dams supported the SDC predictions. Variations of phytoplankton species composition in several cascade dams, such as Datengxia (DTX) and Changzhou (CZ), also supported the SDC predictions. Moreover, the stations near the dams showed the maximum or minimum values of total species numbers in each cascade segment. Predictive model indicated that the types of phytoplankton decreased in the middle reaches, conforming to SDC predictions. In the whole system of cascading dams, an increase in silicate concentration and phytoplankton communities in the downstream was also consistent with SDC predictions. Therefore, these findings aligned with the SDC predictions in the aspects of both single dam and whole cascade dam system to some extent. In future research, our aim is to further investigate the effects of cascade damming on additional phytoplankton-related indices in this aquatic ecosystem. We hope to gather more comprehensive data to fully validate the SDC predictions.

The concept of discontinuity in project marketing research: emergence, dissipation and glimpses of the future

PurposeThis study aims to focus on a specific project marketing concept, i.e. “discontinuity,” and analyzes how this concept emerged in project marketing, becoming its key scholarly embodiment, how it became decoupled from the increasingly service-intensive project business practice and what the relevance of discontinuity is for project marketers moving forward.Design/methodology/approachThis study is built on a systematic literature review of 31 years (1993–2023) of publishing data from major marketing and management journals.FindingsThis study provides three findings. First, the author reveals the risks related to marketing scholars and practitioners losing sight of each other as business practices evolve much faster than scholarly research can keep up. Second, the author highlights the role of interdisciplinary collaboration in advancing conceptual innovations. Finally, the research elucidates the need for broader metatheoretical reflection to keep this research tradition on an upward trajectory.Research limitations/implicationsThe aim of this study is not to criticize project marketing, as many strands of business-to-business (B2B) marketing face the same challenge, but to elucidate a need for conceptual innovations, collaboration with practitioners and other disciplines and broader metatheoretical reflection to keep this research tradition on an upward trajectory.Originality/valueThis study makes several contributions to the project marketing research tradition. First, it reviews the emergence and dissipation of the concept of discontinuity, drawing on semantical, etymological and epistemological insights. It also reflects on recent disruptions in the marketplace and envisions future research trajectories for this elusive concept. In addition, the author develops a conceptual framework that combines project types with exchange elements in project and service businesses. This conceptual framework helps elucidate what part of the exchange is continuing and what is discontinuing in the resulting business relationships. Furthermore, the research contributes to B2B marketing more broadly by highlighting the fleeting correspondence between theory and the real world. It underscores the need for constant updates to maintain relevance.

Continuity and discontinuity in evolutionary processes with emphasis on plants

The present work is aimed to review the concepts of continuity and discontinuity in the reproductive processes and their impact on the evolutionary outcome, emphasizing on the plant model. Let be stated that evolutionary changes need to pass down generation after generation through the cellular reproductive mechanisms, and these mechanisms can account for changes from single nucleotide to genome-wide mutations. Patterns of continuity and discontinuity in sexual and asexual species pose notorious differences as the involvement of the cellular genetic material from single or different individuals, the changes in the ploidy level, or the independence between nuclear and plastid genomes. One relevant aspect of the plant model is the open system for pollen donation, which can be driven from every male flower to every female flower in the neighborhood, as well as the facilitated seed dispersal patterns, that may break or restore the contact between populations. Three significative processes are distinguishable, syngenesis, anagenesis, and cladogenesis. The syngenesis refers to the reproduction between individuals, either if they pertain to the same species, from different populations or even from different species. The anagenesis refers to the pursuit of all the possible rearrangements of genes and alleles pooled in a population of individuals, and the cladogenesis represents the absence of reproduction that leads to differentiation. Recent developments on the genomic analysis of single cells, single chromosomes and fragments of homologous chromosomes could bring new insights into the processes of the evolution, in generational time and in a broad spectrum of spatial/geographic extents.

A Geostatistical Framework Predicting Zooplankton Abundance in a Large River: Management Implications towards Potamoplankton Sustainability.

The zooplankton community is a widely used bioindicator for the biological assessment of riverine aquatic ecosystems. Phyto-zooplankton interaction and spatially varying river environment parameters perceivably govern their spatial distribution in a large river. This invites the challenge of predicting zooplankton abundance along the river channel. The present article has proposed a geostatistical framework to predict zooplankton abundance along the river course while decoupling phyto-zooplankton relationship from spatial dependency. The strength of secondary data on the river Narmada-a large tropical river in India-has been utilised to accomplish the goal. The nonlinear logistic regression kriging has been found to be the most effective framework. The phyto-zooplankton relationship captured 66% of zooplankton variability, having moderate (37%) residual spatial dependence. The results have shown longitudinally fluctuating spatial variability, which supports the river serial discontinuity concept. The proposed framework has generated smooth zooplankton abundance and sustainability predictive maps that have allowed detection of the change point locations of zooplankton abundance. The map has precisely identified the most productive zone of zooplankton sustainability. The study also has appraised obtaining approximate data in the areas where sampling is infeasible, which will be helpful for location-specific management strategies on a lower spatial scale.

Phytoplankton species richness as an ecological indicator in a subtropical, human‐regulated, fragmented river

AbstractSince the serial discontinuity concept (SDC) of rivers is proposed, few studies have tested it in a highly fragmented river ecosystem. In this study, environmental factors, phytoplankton species richness, and SDC predictions were demonstrated along the 13 cascade dams in a subtropical river (China). Our results indicated that among environmental factors, water temperature and transparency have seasonal differences, and river width has spatial differences; total species richness (TSR) increases from upstream to downstream, and distance is the reason for its variation. In addition, TSR also has spatial variations in each cascade dam, with the maximum or minimum value of each cascade section often occurring near the dam. A predictive model was constructed and revealed that seasonal differences in species richness were more significant than spatial differences, which were mainly observed during wet periods. Taken together, these results suggest that the construction of cascading dams enhances spatial differences in phytoplankton species richness, especially during periods of abundant water. In addition, environmental parameters such as water temperature, pH, and DO and TSR all support SDC predictions. In the future, we will continue to investigate this aquatic ecosystem to study more phytoplankton‐related indices affected by the cascade damming, and hope to fully validate the SDC predictions.

O dyskontynuacji prac parlamentu raz jeszcze

Once again about the discontinuation of the work of the parliament The author analyses the historical foundations of the concept of discontinuity in the work of the parliament. It presents the development of this principle in the European legal culture and activities in the initial period of forming the parliament in Poland. He indicates various ways of justifying the existence of the present-day principle of discontinuation in a democratic state ruled by law. In particular, it refers to the concept of general principles of law. It also analyses the jurisprudence of the Polish Constitutional Tribunal. Recognizes the principle of discontinuation of the work of the parliament as a permanent element of the state system. However, he points to the problems of integrating it into the system of norms of the Constitution of 1997.

Rethinking biodiversity patterns and processes in stream ecosystems

AbstractA major goal of community ecology is understanding the processes responsible for generating biodiversity patterns along spatial and environmental gradients. In stream ecosystems, system‐specific conceptual frameworks have dominated research describing biodiversity change along longitudinal gradients of river networks. However, support for these conceptual frameworks has been mixed, mainly applicable to specific stream ecosystems and biomes, and these frameworks have placed less emphasis on general mechanisms driving biodiversity patterns. Rethinking biodiversity patterns and processes in stream ecosystems with a focus on the overarching mechanisms common across ecosystems will provide a more holistic understanding of why biodiversity patterns vary along river networks. In this study, we apply the theory of ecological communities (TEC) conceptual framework to stream ecosystems to focus explicitly on the core ecological processes structuring communities: dispersal, speciation, niche selection, and ecological drift. Using a unique case study from high‐elevation networks of connected lakes and streams, we sampled stream invertebrate communities in the Sierra Nevada, California, USA to test established stream ecology frameworks and compared them with the TEC framework. Local diversity increased and β‐diversity decreased moving downstream from the headwaters, consistent with the river continuum concept and the small but mighty framework of mountain stream biodiversity. Local diversity was also structured by distance below upstream lakes, where diversity increased with distance below upstream lakes, in support of the serial discontinuity concept. Despite some support for the biodiversity patterns predicted from the stream ecology frameworks, no single framework was fully supported, suggesting “context dependence.” By framing our results under the TEC, we found that species diversity was structured by niche selection, where local diversity was highest in environmentally favorable sites. Local diversity was also highest in sites with small community sizes, countering the predicted effects of ecological drift. Moreover, higher β‐diversity in the headwaters was influenced by dispersal and niche selection, where environmentally harsh and spatially isolated sites exhibit higher community variation. Taken together our results suggest that combining system‐specific ecological frameworks with the TEC provides a powerful approach for inferring the mechanisms driving biodiversity patterns and provides a path toward generalization of biodiversity research across ecosystems.

The waterscape continuum concept: Rethinking boundaries in ecosystems

AbstractContinuity and discontinuity are fundamental concepts of ecosystem science. In reality, both continuities and discontinuities can exist; lentic and lotic systems can expand and contract as can soil/rock moisture and groundwater systems. Surface water, soil moisture, rock moisture, and groundwater, represent hydrological domains that are interconnected. Under a state of expansion each domain may be characterized by spatial continuity; for instance, a river may be entirely flow connected. However, under a state of contraction, discontinuities may appear, and the river may become fragmented. The rate of expansion and contraction in each domain, that is land‐, lentic‐, and lotic‐scapes, is a function of topography, geology, climate, and biota. In an effort to reconcile older, and sometimes incongruous, concepts of continuity and discontinuity we present a view of water‐connected ecosystems, such as riverscapes and catchments that are nested upon and within the uppermost layer of Earth. This layer is the key interface between the lithosphere, atmosphere, hydrosphere, and biosphere, and is known as the critical zone (CZ). We present the waterscape continuum and define it as the spatially and temporally dynamic water upon and within the CZ. To guide ecosystem research (across the land‐, lentic‐, and lotic‐scapes), we introduce the waterscape continuum template (WCT). We propose the waterscape continuum and the WCT can enhance our understanding of ecosystem processes and mechanisms.This article is categorized under: Science of Water > Hydrological Processes Water and Life > Nature of Freshwater Ecosystems

Conceptualising Discontinuity: Pavel Florenskii’s Preryvnost’ as a Universal Paradigm of Knowledge

Discontinuity (preryvnost’ / прерывность) is a pivotal concept in Pavel Florenskii’s philosophy and theory of knowledge. He utilises it in many fields and subjects: mathematics, physics, semiotics, aesthetics, theology, and literature. Florenskii’s universe is a “discontinuous double” in which an earthly and natural state of things is opposed to an upper-world that is ruled by different geometrical laws and is knowable only by abstraction. In between there is always a threshold (a symbol, an “icon”) that connects the two. The general intent of this article is, on the one hand, to give an indication of the main directions of the concept of discontinuity within Florenskii’s works and, on the other hand, to highlight its relevance for a “philosophy of culture” and for a “philosophy of the symbolic forms”, but also – as Florenskii puts it – for a specific understanding of the “Russian mind”. The article also devotes a section to the literary aspects of Florenskii’s concept of discontinuity (less explored by Florenskii scholarship and perhaps by the author himself), which involve among other things a reading of Shakespeare’s Hamlet and an original and ambitious attempt of interpreting physical space in Dante’s Divine Comedy.

Restoring morphodynamics downstream from Alpine dams: Development of a geomorphological version of the serial discontinuity concept

There is well-established evidence that dams disconnect upstream to downstream sediment flux in rivers and that this may have negative impact on downstream ecosystems. For this reason, the development of environmental flows now includes sediment supply and transport whether through reconnecting upstream supplied sediment to a river downstream of a dam, eco-morphogenic flows to rework the stream bed, or artificial sediment supply. However, especially in Alpine systems, there may be unregulated tributaries that are able to deliver gravel and coarser sediment naturally to compensate for the effects of dam-related sediment disconnection. To represent these effects we propose a geomorphic form of the serial discontinuity concept and apply it to two hydropower dam-impacted Alpine streams in the Swiss Pennine Alps. Conceptually, the relative position of a dam influences the degree of coarse sediment disconnection as well as the rate of coarse sediment recovery, especially as many Alpine valleys have strong down-valley gradients in tributary sediment delivery. In both case-studies, there was rapid recovery in likely coarse sediment delivery downstream of the dams. By following geomorphic response of the rivers to eco-morphogenic flow trials, proposed as a solution to perceived dam-driven coarse-sediment disconnection, we confirmed that both rivers are likely to have more than sufficient natural coarse sediment supply and unregulated floods. Natural coarse sediment supply is rarely considered in the management of Alpine streams impacted by hydropower but it needs to be evaluated through a geomorphological assessment, considering both the geomorphic context of the river reaches downstream of the dam and the geomorphic attributes of the basin in which the dam is found.

3D Numerical Prediction of Thermal Weakening of Granite under Tension

This paper deals with numerical prediction of temperature (weakening) effects on the tensile strength of granitic rock. A 3D numerical approach based on the embedded discontinuity finite elements is developed for this purpose. The governing thermo-mechanical initial/boundary value problem is solved with an explicit (in time) staggered method while using extreme mass scaling to increase the critical time step. Rock fracture is represented by the embedded discontinuity concept implemented here with the linear (4-node) tetrahedral elements. The rock is modelled as a linear elastic (up to fracture by the Rankine criterion) heterogeneous material consisting of Quartz, Feldspar and Biotite minerals. Due to its strong and anomalous temperature dependence upon approaching the α-β transition at the Curie point (~573 °C), only Quartz in the numerical rock depends on temperature in the present approach. In the numerical testing, the sample is first volumetrically heated to a target temperature. Then, the uniaxial tension test is performed on the cooled down sample. The simulations demonstrate the validity of the proposed approach as the experimental deterioration, by thermally induced cracking, of the rock tensile strength is predicted with a good accuracy.

Relationship between Nanomechanical Responses of Interfacial Intermetallic Compound Layers and Impact Reliability of Solder Joints

This study aims to evaluate solder joint reliability under high speed impact tests using nanoindentation properties of intermetallic compounds (IMCs) at the joint interface. Sn–Ag based solder joints with different kinds of interfacial IMCs were obtained through the design of solder alloy/substrate material combinations. Nanoindentation was applied to investigate the mechanical properties of IMCs, including hardness, Young’s modulus, work hardening exponent, yield strength, and plastic ability. Experimental results suggest that nanoindentation responses of IMCs at joint interface definitely dominates joint impact performance. The greater the plastic ability the interfacial IMC exhibits, the superior impact energy the solder joints possess. The concept of mechanical and geometrical discontinuities was also proposed to explain brittle fracture of the solder joints with bi-layer interfacial IMCs subject to impact load.

Linking life history strategies and historical baseline information shows effects of altered flow regimes and impoundments on freshwater mussel assemblages

Abstract Human impacts on aquatic ecosystems are causing shifts in the composition and distribution of species, leading to subsequent changes in community structure. However, these changes may not be fully realised because of inadequate baseline information. In Texas, such baseline information is generally lacking for cryptic aquatic species such as unionid mussels, which will be likely to impede identification of impacted populations, potential causal factors, and the setting or achieving of management goals. The Navasota River, located in central Texas, is an exception, having been comprehensively surveyed more than 40 years ago, prior to large‐scale impoundment of this system. Hierarchical cluster analysis, nonmetric multidimensional scaling, and fuzzy set ordination were performed to compare assemblage structure from the 1975 survey to that of a recent survey in 2016 at similar sampling locations. Comparing sites based on the presence–absence of mussel species, we found no significant differences between the number of taxa and species present; however, we did find significant filtering of mussel life history strategies. Specifically, prior to impoundment, we found that mussel assemblages were filtered based on longitudinal patterns in life history strategy from taxa that are adapted to disturbed habitats to those favoured in more stable habitats with low environmental variation. However, following large‐scale impoundment after 1975, we saw a shift in the hydrologic regime towards consistent, homogenised flows and a shift in assemblage structure towards equilibrium species. This shift appears to represent a discontinuity, wherein river impoundment alters physical parameters of the hydrologic regime and these changes in turn modify biotic patterns and processes. Our results provide another example of how large dams can restructure mussel assemblages, highlight the importance of incorporating reference or baseline conditions wherever possible when evaluating the conservation status of aquatic biota, and provide further evidence for the use of life history theory and the serial discontinuity concept in predicting the consequences of flow alteration and river impoundment.

A Comparative Analysis of Women’s Political Rights, 1981–2004: The Role of Legal Traditions

ABSTRACT In this article, we focus on the legal system to explain cross-national and temporal variance in women’s political rights. Compared to alternative legal systems, we find that common law is correlated with less political rights for women. The concepts of political discontinuity and legal memory are central to our theoretical framework. Political discontinuity occurs in times of deep political disruptions; for instance, during revolutionary periods. Whereas typically revolutions did not readily yield lasting improvements in women’s political rights, individual and systemic forms of legal memory meant that later progress toward political equality was facilitated. It is hard to overestimate the influence of legal systems on women’s rights around the world. Using available data for 148 countries from 1981 to 2004, we found that legal systems’ effect is robust to inclusion of more recent periods of upheaval, various model specifications and functional forms, disparate datasets, and different outcome variables.

Evaluating spatiotemporal variation in water chemistry of the upper Colorado River using longitudinal profiling

AbstractStream water chemistry is traditionally measured as variation over time at fixed sites, with sparse sites providing a crude understanding of spatial heterogeneity. An alternative Lagrangian reference frame measures changes with respect to both space and time as water travels through a network. Here, we collected sensor‐based measurements of water chemistry at high spatial resolution along nearly 500 km of the Upper Colorado River. Our objective was to understand sources of spatiotemporal heterogeneity across different solutes and determine whether longitudinal change manifests as smooth gradients as suggested by the River Continuum Concept (RCC) or as abrupt changes as suggested by the Serial Discontinuity Concept (SDC). Our results demonstrate that Lagrangian sampling integrates spatiotemporal variation, and profiles reflect processes that vary in both space and time and over different scales. Over each day of sampling, water temperature (T) and dissolved oxygen (DO) varied strongly in response to diel solar cycles, with most of the variation driven by sampling time rather than sampling location. Equilibration of T and DO with the atmosphere limited small scale spatial heterogeneity, with variation at the entire profile scale driven by regional climate gradients. As such, T and DO profiles more closely approximated the smooth gradients of the RCC (though including temporal sampling artefacts). Conversely, variation in specific conductance and nitrate (NO3‐N) was largely driven by spatial patterns of lateral inflows such as tributaries and groundwater. This resulted in discrete shifts in the profiles at or downstream of discontinuities, appearing as the profiles expected with the SDC. The concatenation of spatiotemporal variation that produces observed Lagrangian profiles presents interpretive challenges but also augments our understanding of where, how, and critically why water chemistry changes in time and space as it moves through river networks.

Effect of splat-interface discontinuity on effective thermal conductivity of plasma sprayed thermal barrier coating

The thermal barrier coating obtained by atmospheric plasma spraying (APS TBCs) has a distinct lamellar microstructure, in which the splats discontinuous interfaces running parallel to the metal/ceramic interface contribute largely to the reduction in the effective thermal conductivity of APS TBCs. The dependency of such contribution on the topological structure of the interface discontinuity is investigated in the present work. Firstly, the concept of discontinuity of splats interfaces was defined to quantify the splats discontinuous interfaces revealed by microscopic observations. Then, the microstructure model with a random distribution of discontinuous interfaces was established by utilizing the finite element simulation method to investigate the effect of interlayer discontinuity on thermal conductivity of the APS TBCs. Finally, an optimal topological structure of the interface discontinuity was found to be responsible for the lowest effective thermal conductivity of the APS TBCs and typical parametrical tendencies demonstrated.