arXiv subjects

Anupama Sharma

Publications and source records attributed to Anupama Sharma.

5 recordsLinked to original sources

arXiv2026

Nonlinear Feedbacks Between Host Behavior and Vector Adaptation in a Multi-Host Vector-Borne Disease Model

Insecticide-treated nets (ITN) are an effective and low-cost intervention for controlling vector-borne disease (VBD), however, their use depends on individual decisions based on perceived cost and risk of infection. This study investigates a nonlinear multi-host model for the transmission of VBD with endogenous strategic control. We assume that hosts' adoption of ITN emerges from the payoff-based decision-making, creating a nonlinear coupling with disease prevalence. We model vector preference as a function of ITN coverage to probe the complex interplay among individual choices, disease prevalence, and its control in a multi-host setting. The qualitative behavior of the system is characterized by the thresholds $R_0$ and $R_c$, which determine the existence and local stability of the disease-free and endemic equilibria. The system exhibits rich dynamical behavior; hence, we provide a bifurcation analysis identifying the conditions for saddle-node and Hopf bifurcations. Our results demonstrate that the interaction between the perceived cost of ITN and the infection risk can induce critical transitions, including regime shift from stable endemic states to sustained periodic oscillations. Furthermore, we identify a counterintuitive effect whereby complete ITN adoption by the primary host can increase the overall prevalence in the secondary host due to adaptive shifts of vector feeding behavior.

q-bio.PE↗

arXiv2026

Host diversity and adaptive vector feeding preferences shape disease burden in vector-borne diseases

Vector-borne diseases often involve multiple host species that differ in their ability to sustain transmission. At the same time, vector feeding preferences can change in response to host availability and disease-control interventions, potentially altering disease dynamics in unexpected ways. We develop a two-host vector-borne disease model that links host diversity, adaptive vector feeding preferences, and disease transmission. We demonstrate that the effect of host diversity on disease transmission is mediated by vector feeding behavior and cannot be inferred from host abundance alone. In particular, we identify a critical threshold, $R_{0c}$, that determines whether shifts in vector preference amplify or suppress disease burden in a focal host. This threshold marks a qualitative transition in system behavior and provides a basis for predicting epidemiological responses to changes in host composition and vector behavior. Using adaptive dynamics, we further show that vector populations may evolve toward either specialist or opportunistic feeding strategies depending on host encounter rates and trade-off strength. Finally, we demonstrate that host-targeted interventions can induce adaptive changes in vector feeding behavior that reduce prevalence in the protected host while potentially increasing overall infection burden. Our results highlight how evolutionary responses of vector population can generate unexpected epidemiological outcomes and should be considered when designing disease-control strategies.

q-bio.PE↗

arXiv2026

Co-spreading dynamics of smoking behavior and awareness on social contact networks

Smoking behavior and awareness co-spread through social interactions, giving rise to coupled contagion processes on social contact networks. In addition to initiation and cessation, awareness of the harmful effects of smoking plays an important role in shaping individual behavior and population-level outcomes. In this work, we develop a mathematical model to study the coupled dynamics of smoking behavior, quitting, and awareness in a population. A deterministic framework based on ordinary differential equations is first formulated to capture the interplay between social influence and awareness-driven behavioral change. Analysis of the model reveals the existence of smoking-free and smoking-endemic steady states, and identifies conditions under which awareness can reduce or suppress the persistence of smoking. Since social interactions are often localized rather than well mixed, the mean-field description is then extended to a network-based model that incorporates structured contact patterns. Numerical simulations performed on empirical social networks indicate that contact heterogeneity and localized awareness spreading can influence the effectiveness of interventions. Our findings underscore the importance of population structure when devising awareness-based intervention strategies for smoking cessation.

physics.soc-ph↗

arXiv2025

Towards Evaluating Robustness of Prompt Adherence in Text to Image Models

The advancements in the domain of LLMs in recent years have surprised many, showcasing their remarkable capabilities and diverse applications. Their potential applications in various real-world scenarios have led to significant research on their reliability and effectiveness. On the other hand, multimodal LLMs and Text-to-Image models have only recently gained prominence, especially when compared to text-only LLMs. Their reliability remains constrained due to insufficient research on assessing their performance and robustness. This paper aims to establish a comprehensive evaluation framework for Text-to-Image models, concentrating particularly on their adherence to prompts. We created a novel dataset that aimed to assess the robustness of these models in generating images that conform to the specified factors of variation in the input text prompts. Our evaluation studies present findings on three variants of Stable Diffusion models: Stable Diffusion 3 Medium, Stable Diffusion 3.5 Large, and Stable Diffusion 3.5 Large Turbo, and two variants of Janus models: Janus Pro 1B and Janus Pro 7B. We introduce a pipeline that leverages text descriptions generated by the gpt-4o model for our ground-truth images, which are then used to generate artificial images by passing these descriptions to the Text-to-Image models. We then pass these generated images again through gpt-4o using the same system prompt and compare the variation between the two descriptions. Our results reveal that these models struggle to create simple binary images with only two factors of variation: a simple geometric shape and its location. We also show, using pre-trained VAEs on our dataset, that they fail to generate images that follow our input dataset distribution.

cs.CV↗

arXiv2017

Epidemic prevalence information on social networks mediates emergent collective outcomes in voluntary vaccine schemes

The success of a vaccination program is crucially dependent on its adoption by a critical fraction of the population, as the resulting herd immunity prevents future outbreaks of an epidemic. However, the effectiveness of a campaign can engender its own undoing if individuals choose to not get vaccinated in the belief that they are protected by herd immunity. Although this may appear to be an optimal decision, based on a rational appraisal of cost and benefits to the individual, it exposes the population to subsequent outbreaks. We investigate if voluntary vaccination can emerge in a an integrated model of an epidemic spreading on a social network of rational agents that make informed decisions whether to be vaccinated. The information available to each agent includes the prevalence of the disease in their local network neighborhood and/or globally in the population, as well as the fraction of their neighbors that are protected against the disease. Crucially, the payoffs governing the decision of agents evolve with disease prevalence, resulting in the co-evolution of vaccine uptake behavior with the spread of the contagion. The collective behavior of the agents responding to local prevalence can lead to a significant reduction in the final epidemic size, particularly for less contagious diseases having low basic reproduction number $R_0$. Near the epidemic threshold ($R_0\approx1$) the use of local prevalence information can result in a dichotomous response in final vaccine coverage. The implications of our results suggest the nature of information used by individuals is a critical factor determining the success of public health intervention schemes that involve mass vaccination.

physics.soc-ph↗