Competition For Resources Research Articles

Impact of Tree Geometry on the Growth and Yield Performance of Black Gram (Vigna mungo L.) under Kadam (Neolamarckia cadamba Roxb.) based Agroforestry System

Agroforestry is an environmentally conscious and comprehensive method of land management that entails cultivating agricultural crops, forest trees, and animals in conjunction on the same parcel of land through the implementation of suitable management strategies. The present study entitled “Impact of tree geometry on the growth and yield performance of Black Gram (Vigna mungo L.) under Kadam (Neolamarckia cadamba Roxb.) based Agroforestry System” was conducted during the Kharif season of 2022-23 within an already established 2-year-old plantation situated at Forestry research farm, RLBCAU, Jhansi. The study encompasses three different spacings, i.e., S1- 5 m x 5 m, S2- 5 m x 4 m and S3- 5 m x 3m. A randomized block design having four treatments each replicated five times was laid out, Outcomes of research revealed that sole cropping of black gram exhibited higher plant height (77.44 cm), leaf and branch numbers (6.38 and 5.32, respectively), dry matter accumulation (17.05 g/plant for above-ground and 2.12 g/plant for below-ground), leaf area (2183.06 cm2), root nodules (11.54), shorter phenological duration viz., 50% flowering, 50% pod setting and maturity (40.11 days, 54.49 days, and 70.84 days, respectively). It also demonstrated significantly higher yield attributes such as number of pods and seeds per pod (27.28), number of seeds per pod (5.82), test weight (36.73 g), grain yield (0.79 t ha-1), straw yield (1.78 t ha-1), biological yield (2.57 t ha-1), harvest index (30.63 %), and grain-to-straw ratio (0.44) compared to the intercropped. Among all the agroforestry treatments Neolamarckia cadamba at 5 m × 5 m with Vigna mungo, found to perform better than closer spacing (i.e., 5 m x 4 m and 5 m x 3 m) spatial arrangements. The study encountered challenges in achieving an optimal balance between tree-crop interactions and resource competition, which are critical factors in agroforestry systems. Nevertheless, it provides significant contributions by offering insights into the optimization of tree geometry, enhancing both yield performance and the sustainability of such integrated systems.

Exploring evolutionary psychology perspectives on Sex differences in aggression

This research aims to extend the understanding of sex differences in aggression by applying the lens of Life History Theory to evaluate the effects of age, muscle, occupation, and other variables on aggression tactics. The study involves a resource competition game with 200 participants of both sexes, who can use direct or indirect aggression strategies. A post-game survey will assess the relationship between these variables and the differences in aggression levels. The authors predict that even when taking into account other factors affecting aggression, men will prefer direct aggression, and women will prefer indirect aggression. In conclusion, this work is intended to expand current knowledge of sex differences in aggression and contribute to the field of evolutionary psychology.

School-level competition for US high school extracurricular resources

ABSTRACT In the United States, families know that extracurricular activities serve as a qualitative distinction in postsecondary admissions and merit-based aid awards, leading to competition in their participation and leadership positions. Despite the extensive literature supporting extracurricular activities, there is an incomplete picture of how school characteristics influence high school students’ participation and holding of leadership positions within extracurricular activities. Using the US Education Longitudinal Study of 2002, our study explores how the school characteristics of socioeconomic status, test scores, class size, school urbanicity, and school control shape twelfth-grade participation and holding leadership positions in ten school-sponsored extracurricular areas. From our results, we offer recommendations on how schools can create equitable participation levels and discuss the ever-expanding role of extracurricular activities in defining merit.

Dragonfly: A Master of Migration

Insect migration is vital for ecosystems, with trillions of individuals redistributing biomass and nutrients annually. Dragonflies, particularly Pantala flavescens are notable migratory insects capable of traveling over 6,000 kilometres across generations. Their migrations are influenced by resource availability, breeding needs, environmental conditions, and competition avoidance. This behaviour includes both seasonal movements and sporadic flights triggered by temperature and wind cues. Despite their well-known life cycle from aquatic nymphs to aerial adults, many aspects of their migration remain under-researched. Dragonflies exhibit diverse flight mechanisms, employing four distinct modes: counter-stroking for hovering, phased-stroking for cruising synchronized stroking for acceleration, and gliding for energy conservation. Migratory species show specific wing adaptations for improved endurance, such as elongated forewings and larger hindwings, along with sensory enhancements like enlarged thoracic setae. Specialized flight muscles allow for independent wing control, essential for complex movements. Additionally, physiological adaptations like fat accumulation and rapid development support their migratory behaviour. Recent studies also highlight nocturnal migrations, revealing unique flight patterns and adaptations. Together, these traits underscore the evolutionary success of dragonflies in diverse ecosystems.

Stable isotope ratios indicate trophic niche overlap in three sympatric delphinid species in the Eastern Ionian Sea

AbstractStudying the sympatric ecology of closely related marine top predator species is of interest both from an ecological and conservation standpoint, because it provides insights into ecosystem functioning, how such species avoid competitive exclusion, and how human stressors may impact these patterns. In this study, we examine the isotopic niche of three sympatric dolphin species that inhabit the eastern Ionian Sea: the common dolphin (Delphinus delphis), the striped dolphin (Stenella coeruleoalba), and the common bottlenose dolphin (Tursiops truncatus). We used carbon, nitrogen, and sulfur isotope ratios to construct three‐dimensional isotope niches and calculate niche sizes and their overlaps among the three species to study interspecific competition for resources. Common dolphin niche overlapped with that of the striped dolphin by 77%, suggesting potential resource competition between these two species. The niche overlap between striped/common dolphins and bottlenose dolphins was much lower (47%). Large differences in isotopic ratios were found between the bottlenose dolphins of the Ionian Sea and those of a largely isolated population in the adjacent semienclosed Gulf of Ambracia, further corroborating the previously documented isolation between the two populations.

Human–wildlife interactions on the tidal flats of the Bijagós Archipelago: does shellfishing affect migratory shorebirds?

The Bijagós Archipelago in West Africa is home to an ethnic group with a rich cultural heritage that is tightly linked to nature. The Bijagós people have a shared cultural identity, but management of natural resources varies between islands due to island‐specific context with regards to socio‐political organization and strength of cultural heritage. Across the archipelago, bivalves harvested manually from the mudflats are an important part of the Bijagós people's diet, economy, and culture. Migratory shorebirds share the use of these mudflats during their non‐breeding season, consuming macrobenthos such as crustaceans and bivalves, including those harvested by local people. At the end of their stay in the Bijagós, just before taking off for their migratory flight, it is particularly important that shorebirds have access to undisturbed feeding areas with suitable food resources. In this study we start by exploring shellfishing patterns across different management regimes (via questionnaires to local shellfishers), then assess seasonal variation in the direct impact of shellfishing on shorebirds (through competition for resources and space), and finally quantify the indirect impact of sediment disturbance due to shellfishing upon shorebird prey availability with an experimental approach. Results indicate that bivalve resources are better managed in areas with formal protection, while traditional management based on cultural beliefs results in poorer stock conditions. Interestingly, the high density of shellfishers in mid‐winter (14.4 ind. km−2) decreased markedly towards shorebirds' fuelling period, when they benefit the most from reduced disturbance on the mudflats. Regardless of the season, no direct competition for resources was detected due to differences in targeted sizes. Indirect impacts caused by sediment disturbance during shellfishing were also mostly absent, causing only a small reduction on shorebirds prey density but with no effect on the available biomass.

Gastrointestinal morphology is an effective functional dietary proxy that predicts small mammal community structure.

The availability and quality of food resources can alter the intensity of competition and predation pressure within communities. Understanding species capacity to respond to global change-driven shifts in resource distribution is therefore crucial for biodiversity conservation. Small mammal communities are often structured by competition for food resources, but understanding and monitoring these processes are currently hindered by lack of functional dietary trait information in these hard-to-sample systems. In this study, we collected a comprehensive suite of gastrointestinal (GI) measurements from 26 small mammal species (including some never reported), compared them with more traditional craniodental traits in predicting dietary guild, and used them in a novel way to understand how diet structures 22 small mammal communities across the Appalachian Mountains of eastern North America. As predicted, we found GI traits to be effective dietary trait proxies; they were equally or more accurate than craniodental proportions in predicting the dietary guild of individual species. Furthermore, at the community level, we found that both the mean and functional dispersion of GI length were positively correlated with latitude and measures of temperature seasonality. Our results indicate that small mammal communities in more seasonal environments are filtered to include species with longer GI tracts (on average) as well as those that can partition food resources more finely, as expected based on the lower productivity of these regions. Conversely, communities in less seasonal environments display functional redundancy from the addition of species with short to intermediate GI lengths. Proportions of the GI tract represent novel dietary traits that can illuminate community assembly processes across regional environmental gradients and in the face of changing timing and availability of resources.

Allelopathic Interactions Between the Green-Tide-Forming Ulva prolifera and the Golden-Tide-Forming Sargassum horneri Under Controlled Laboratory Conditions

Harmful algal blooms (HABs) represent a significant global marine ecological disaster. In the Yellow Sea, green and golden tides often occur simultaneously or sequentially, suggesting that interspecific competition involves not only spatial and resource competition but also allelopathy. This study investigated the allelopathic interactions between Ulva prolifera and Sargassum horneri using physiological and biochemical parameters, including relative growth rate (RGR), cell ultrastructure, chlorophyll fluorescence, enzyme activity, and metabolomics analysis. The results showed that S. horneri filtrate significantly inhibited U. prolifera growth, while U. prolifera filtrate had no significant effect on S. horneri. Both algal filtrates caused cellular damage and affected photosynthesis, enzyme activities, and metabolism. However, their allelopathic responses differed: U. prolifera may rely on internal compensatory mechanisms, while S. horneri may depend on defense strategies. These findings provide insights into the dynamics of green and golden tides and support the scientific control of HABs through allelopathy.

Request Deadline Split and Interference‐Aware Request Migration in Edge Cloud

ABSTRACTEdge computing extends computing resources from the data center to the edge of the network to better handle latency‐sensitive tasks. However, with the rise of the Internet of Things, edge devices with limited processing capabilities face difficulties in executing requests with fluctuating request peaks. In order to meet the deadline constraints of latency‐sensitive tasks, a feasible solution is to offload some latency‐sensitive tasks to other nearby edge devices. This article studies the problem of request migration in edge computing systems and minimizes the request deadline violation rate based on actual online arrival patterns, performance interference phenomena, and deadline constraints. Since a request contains multiple services and request migration will lead to changes in server resource competition pressure, we split the problem into three sub‐problems, dividing the request deadline to determine the maximum response time of the service, determining the performance of the service under different resource pressures and the request migration strategies. To this end, we propose two deadline splitting methods, a performance interference model under multi‐resource pressure, and two heuristic request migration strategies. Since this article considers online edge scenarios, the number and type of requests are black boxes. We conduct simulation experiments and find that our method has only one‐third the number of request violations of other methods.

How root-grafted trees form networks: Modeling network dynamics with pyNET

Natural root grafting is a widespread phenomenon in woody plants. While previous studies have focused on the effects of reduced growth and resource exchange at the individual level, we lack an understanding of the collective behavior of groups of grafted trees and the networks they form. Here, we present pyNET, a mechanistic agent-based model designed to explore the emergence of root graft networks. We performed simulation experiments with different scenarios involving water scarcity and different cost-benefit dynamics. Costs denote the resources required to form root grafts, while benefits denote the water redistributed among trees. Our model successfully replicates observed patterns linking structural variables to network characteristics. Specifically, we were able to reproduce observed characteristics such as grafting frequency and mean group size. In particular, we find that while the network structure is naturally strongly influenced by the size of the root system, the time and resources allocated to grafting are also critical factors. pyNET serves as a valuable tool for exploring the formation of root grafting networks under diverse environmental conditions and understanding their impact on resource competition. Our study supports theory development on the subject and hopefully stimulates further empirical studies.

Competitive interactions shape brain dynamics and computation across species.

Adaptive cognition relies on cooperation across anatomically distributed brain circuits. However, specialised neural systems are also in constant competition for limited processing resources. How does the brain's network architecture enable it to balance these cooperative and competitive tendencies? Here we use computational whole-brain modelling to examine the dynamical and computational relevance of cooperative and competitive interactions in the mammalian connectome. Across human, macaque, and mouse we show that the architecture of the models that most faithfully reproduce brain activity, consistently combines modular cooperative interactions with diffuse, long-range competitive interactions. The model with competitive interactions consistently outperforms the cooperative-only model, with excellent fit to both spatial and dynamical properties of the living brain, which were not explicitly optimised but rather emerge spontaneously. Competitive interactions in the effective connectivity produce greater levels of synergistic information and local-global hierarchy, and lead to superior computational capacity when used for neuromorphic computing. Altogether, this work provides a mechanistic link between network architecture, dynamical properties, and computation in the mammalian brain.

The Reverse Ecology-Based Approach to Design a Bacterial Consortium as Soybean Bioinoculant.

Bioinoculants traditionally rely on selecting efficient microbes from the soil with potential growth-enhancing traits for plants. However, such approaches often neglect microbe-microbe and microbe-plant interactions. In this study, we applied a reverse ecology framework to design and assess a bacterial consortium tailored for soybeans. Our analysis identified Paenibacillus polymyxa, Methylobacterium brachiatum, and Enterobacter sp. as key strains for their synergistic potential in promoting soybean growth. Computational analyses revealed that these selected strains exhibited low competitiveness and metabolic compatibility. Specifically, their complementary metabolic profiles suggested minimal competition for resources and potential for mutualistic interactions. In vitro experiments further supported these findings, demonstrating that the consortium maintained stable growth without inhibitory effects among strains. In addition, greenhouse validation experiments confirmed the efficacy of the microbial consortium in enhancing soybean growth such as root and shoot development and biomass production. Overall, this study underscores the potential of reverse ecology in optimizing microbial consortia design for bioinoculant applications.

The impacts of climate change on violent conflict risk: a review of causal pathways

Abstract The potential impacts of climate change on violent conflict are high on the agenda of scholars and policy makers. This article reviews existing literature to clarify the relationship between climate change and conflict risk, focusing on the roles of temperature and precipitation. While some debate remains, substantial evidence shows that climate change increases conflict risk under specific conditions. We examine four key pathways through which climate affects conflict: (i) economic shocks, (ii), agricultural decline, (iii) natural resources competition, and (iv) migration. Key gaps include limited long-term data, insufficient integrated studies, and the inadequate understanding of causal mechanisms, necessitating transdisciplinary research that addresses social vulnerability and underlying pathways

Enhancing workflow efficiency with a modified Firefly Algorithm for hybrid cloud edge environments

Efficient scheduling of scientific workflows in hybrid cloud-edge environments is crucial for optimizing resource utilization and minimizing completion time. In this study, we evaluate various scheduling algorithms, emphasizing the Modified Firefly Optimization Algorithm (ModFOA) and comparing it with established methods such as Ant Colony Optimization (ACO), Genetic Algorithm (GA), and Particle Swarm Optimization (PSO). We investigate key performance metrics, including makespan, resource utilization, and energy consumption, across both cloud and edge configurations. Scientific workflows often involve complex tasks with dependencies, which can challenge traditional scheduling algorithms. While existing methods show promise, they may not fully address the unique demands of hybrid cloud-edge environments, potentially leading to suboptimal outcomes. Our proposed ModFOA integrates cloud and edge computing resources, offering an effective solution for scheduling workflows in these hybrid environments. Through comparative analysis, ModFOA demonstrates improved performance in reducing makespan and completion times, while maintaining competitive resource utilization and energy efficiency. This study highlights the importance of incorporating cloud-edge integration in scheduling algorithms and showcases ModFOA’s potential to enhance workflow efficiency and resource management across hybrid environments. Future research should focus on refining ModFOA’s parameters and validating its effectiveness in practical hybrid cloud-edge scenarios.

A bottom-up nationwide analysis of sectoral land use reveals spatial heterogeneity across the United States

The high degree of urbanization and economic development in the United States has intensified competition for land resources, leading to land use conflicts and environmental challenges. Addressing these issues first requires an exploration of high-resolution, sector-specific land use patterns. However, existing land classification studies rarely provide spatially explicit data on urban land use across all sectors at a national level. This study aims to fill this gap by analyzing land use areas across various economic sectors in the United States, particularly focusing on urban impervious surfaces. Using a bottom-up approach, we created a full-sector land use inventory, integrating Points of Interest (POI) data, road networks, building characteristics, and geographic information processing techniques. Our primary innovation lies in the development of a spatially explicit database that details sector-specific land use areas nationwide. On this robust foundation, we further explored the heterogeneity of sectoral land use eco-efficiency (SLUEE) among different sectors and states, providing supplementary insights into spatial disparities in urban land use. Our findings reveal significant spatial heterogeneity, with service sectors dominating land use and exhibiting higher SLUEE compared to goods-producing industries. Key sectors such as Professional, Scientific, and Technical Services (441064.58 ha), and Administrative and Support Services (420148.34 ha) are prominent across states according to land use area, reflecting the country's service-oriented economy. Additionally, regional disparities in SLUEE are evident, with jurisdictions like Washington D.C., New York, and California demonstrating more efficient land use. Compared with traditional land use evaluations, our model effectively offers higher spatial resolution, down to the census block level, to sectoral land use evaluation. Building on this robust database, our SLUEE analysis has uncovered notable heterogeneity between sectors and states, offering new insights into cross-sectoral and inter-state land use dynamics that can inform and promote sustainable urban planning.

Effect of Tree Density on Yield and Fruit Quality of the Grafted Hazelnut Cultivar 'Tonda Francescana®'.

Optimizing planting density is crucial for balancing resource competition, light penetration, and tree productivity in orchard systems. This study investigateed the impact of planting density on the yield and fruit quality of the hazelnut cultivar 'Tonda Francescana®' grafted onto Corylus colurna L. rootstocks. The research aimed to assess how different planting densities influenced light penetration, canopy volume, yield, and the nutritional profile of hazelnuts during their sixth growing season. Three planting densities were tested: 625, 1250, and 2500 trees per hectare (low, medium, and high density, respectively). The results show that medium-density planting provided the best balance between light availability, canopy development, and yield efficiency. The synthesis of monounsaturated fatty acids (MUFA) and α-tocopherol (vitamin E) was more prominent in the medium-density system (80.2% and 10.3%, respectively), suggesting a favorable metabolic response to moderate competition for resources. In contrast, high-density planting yielded the most per hectare (2898 kg/ha) but exhibited lower individual tree productivity (1.16 kg). Low-density planting had the highest light penetration (53%) but lower overall yield (822 kg/ha) and quality, with greater starch accumulation in the fruit. In general, medium-density planting optimized both yield and kernel quality, with potential implications for orchard management and breeding strategies to enhance hazelnut production and nutritional value.

Who Benefits from Mass Incarceration? A Stratification Economics Approach to the “Collateral Consequences” of Punishment

A rich empirical literature documents the consequences of mass incarceration for the wealth, health, and safety of Black Americans. Yet it often frames such consequences as a regrettable artifact of racially disproportionate criminal legal system contact, rather than situating the impetus and functioning of the criminal legal system in the wider context of White political and economic domination. Revisiting a quarter century of mass incarceration research through a stratification economics lens, we highlight how mass incarceration shapes Black–White competition for education, employment, and financial resources and contributes to Black–White disparities in well-being. Highlighting persistent research gaps, we propose a research agenda to better understand how mass incarceration contributes to systematic White advantage. To address mass incarceration's consequences and transform the conditions of White political and economic domination under which it arose, we call for legislative and judicial intervention to remedy White hyper-enfranchisement and reparations to eliminate the Black–White wealth gap.

We prefer nighttime, they prefer daytime: Biological rhythm variability in cave‐dwelling whip spiders (Amblypygi: Charontidae) in the Neotropics

AbstractThe lack of understanding regarding how endogenous and behavioral factors affect the biological rhythms of amblypygid arachnids in cave environments underscores a gap in chronobiologic knowledge for this group. This study investigates the influence of specialization on subterranean habitats and the presence of biological rhythms on the locomotor activity patterns of the troglobitic and troglophilic species of the genus Charinus. Specimens collected from carbonate caves in Brazil were subjected to experimental treatments of constant light (LL), constant darkness (DD), and light–dark cycles (LD). The results revealed variations in the distribution of main periods among species, without a uniform pattern. Although some specimens showed greater variability in activity patterns in the DD and LL treatments, no significant differences were observed between troglobites and troglophiles. The lack of a clear distinction in rhythms between the two groups suggests the dynamic nature of circadian rhythms in these populations, where individual variations in activity patterns indicate this behavioral diversity. Additionally, intraspecific competition for food resources, probably intensified by the oligotrophic conditions of the cave environments, may play an important role in shaping these patterns and differences in activity phases. The presence of infradian rhythms and weak circadian rhythms in some individuals underscores the importance of considering non‐photic zeitgebers for a deeper understanding of these rhythms in cave organisms.

Analysis of the resource base and competition of business tourism in Moscow

This paper analyzes the resource base in the context of the competitiveness of business tourism in Moscow. It considers the key elements that form the infrastructure of business tourism, such as the hotel sector, transport accessibility, service level and the presence of business centers. Particular attention is paid to a comparative analysis with other large cities, which helps to identify the strengths and weaknesses of Moscow’s offer. It also considers factors influencing the development of business tourism, including macroeconomic conditions, trends in event organization and digitalization of services. The importance of cooperation between government and the private sector to create an attractive environment for international business clients is emphasized. In conclusion, recommendations are formulated for optimizing the city’s resource base to increase competitiveness and improve the image of Moscow as one of the leading destinations for business tourism.

Meta-Analysis Reveals Behavioral Plasticity, Not Agonistic Behavior, Facilitates Invasion of Brown Anoles (Anolis sagrei) and Replacement of Green Anoles (Anolis carolinensis)

In a meta-analysis, we examined the behavioral portfolio of invasive brown anoles (Anolis sagrei) and native green anoles (Anolis carolinensis) in urban and non-urban environments. We hypothesized that invasive anoles would display more agonistic and bold signals (head bobbing, dewlap extensions, and pushups) than their native-range counterparts and their native competitors. We found that in urban settings, anoles of both species signaled more with dewlap extensions than with head bobs. Brown anoles displayed significantly more in non-urban habitats and their native range compared to urban habitats and invasive ranges. The outcome of our analysis suggests that brown anoles have plastic behavioral portfolios, whereas green anoles have relatively balanced preferences for head bobbing, irrespective of the habitat in which the populations were collected. We attribute the success of the brown anole invasion to the flexible strategy in the face of higher mate competition, higher predation risks, and less resource competition in both urban and invasive ranges. Lastly, we observed publication biases. More studies were conducted with urban and invasive brown anoles and specifically in manipulative mesocosm experimental settings—transplanting populations from native field settings. We show this altered the display rates across all studied signals.