Multipartite viruses are a unique class of viruses that divide their genome into multiple segments, each packaged into a separate viral particle. Unlike traditional viruses, which encapsulate their entire genome within a single particle, multipartite viruses require all genome segments to infect the same host cell for successful replication. This study investigates the infection dynamics of multipartite viruses through mathematical modeling, with a focus on bipartite and tripartite viruses. By comparing their behavior to single-particle viruses, we analyze the factors influencing viral persistence and spread. Our results indicate that the higher number of particles in a virus, the harder it is to maintain an infection. While multipartite infections exhibit shorter durations of infections compared to single-particle infections, their ability to persist suggests a potential benefit. These findings can help develop an understanding into the adaptive mechanisms of multipartite viruses and contribute to a broader understanding of viral evolution and host-virus interactions.

Micro- and nanoscale metal oxides are used in a variety of applications. ZnO and Ga2O3 semiconductors are two metal oxides that have a wide bandgap and find themselves used in today’s electronics, gas sensors, and photodetectors. These two materials are also used in a wide range of temperatures, which means that the chemical bond lengths, vibrational states, defect states, and band-gaps all should be variable. In our experiments, we investigate the T-dependencies of positions, intensities, and widths of Raman peaks/bands for micro- and nanoscale ZnO and Ga2O3. In our studies, in addition to the temperature-dependent Raman spectroscopy we employ scanning electron microscopy (morphology of particles), energy dispersive X-ray spectroscopy (stochiometry) and temperature-dependent photoluminescence spectroscopy (electronic structure).

Human Immunodeficiency Virus (HIV) can exist as syncytia-forming or non-syncytia-forming strains, each utilizing different mechanisms of infection. Understanding the competition between these strains is crucial, as syncytia formation has been linked to increased disease progression and immune system decline. This study develops a mathematical model to analyze their competition, incorporating parameters such as fusion rate, syncytia lifespan, and viral production. Stability analysis and simulations will determine conditions under which one strain dominates or both coexist. By varying key parameters, we aim to understand how syncytia formation influences viral dynamics and infection persistence, providing insights into HIV pathogenesis and potential treatment strategies.

Graphene quantum dots (GQDs) have gained attention in the bioimaging community due to their biocompatibility and enhanced imaging depth in the near infra-red (NIR). Developing and optimizing a facile synthesis method of biocompatible NIR fluorescent GQDs from a variety of precursors remains, therefore, a critical task. Herein, we synthesized various GQD structures capable of fluorescing in the NIR via facile bottom-up pyrolysis of precursor materials (ascorbic acid, chitosan, citric acid, dextran, glucose, glucosamine hydrochloride, hyaluronic acid, l-glutamic acid, polyethylene glycol (PEG), sodium cholate, or sodium citrate). All synthesized GQD structures exhibit remarkable biocompatibility at concentrations of up to 1 mg/mL evaluated by an MTT assay which makes them suitable for a variety of therapeutic applications. All 11 GQD structures are successfully tracked by their NIR fluorescence in vitro bioimaging while exhibiting effective cellular internalization maximized at 12 hours in HEK293 cell line. This work provides a unique comprehensive study exploring a scalable and cost-effective process to synthesize NIR-emissive highly biocompatible GQDs from 11 precursor materials, while theoretically describing their optical properties. Due to their exceptional biocompatibility and photostable NIR emission, GQD structures developed here are expected to become prominent candidates for future clinical fluorescence imaging applications.

Frustrative nonreward (FNR), an adverse reaction brought on by unexpected reward reductions or omissions, can be induced by a downshift in the quantity or quality of the reward. The consummatory successive negative contrast (cSNC) task is a well-known paradigm for studying FNR. cSNC involves monitoring the behavioral reaction to a lower reward (downshift) after exposure to a larger or better incentive. It supports the idea that an acceptable but less preferred reward will be rejected in a situation that is associated with a better and more desirable reward. The intensity of FNR depends, among other things, on the strength of the expectation of the large reward. We assumed that overtraining would enhance reward expectancy such that a reward downshift would lead to a stronger cSNC effect than that observed under regular training conditions. This would support the hypothesis that behavior (licking for sucrose) was guided by reward expectancies—an action. But overtraining often leads to habitual behavior that depends on eliciting stimuli, rather than reward expectancies. A failure to show the cSNC effect after overtraining would be consistent with the hypothesis that behavior had become automatic—a habit. Our experiment was designed to test whether overtraining in the cSNC task would result in behavior becoming either an action or a habit. In the experiment, 47 rats were exposed to different concentrations of sucrose, 32%, 16%, or 4%, and 2 training periods, overtraining for 30 sessions and regular training for 10 sessions. Animals exposed to 32% and 16% sucrose were randomly assigned to two groups depending on the amount of training they received before the downshift, either 30 (overtraining) or 10 sessions (regular training). These animals were given access to 4% sucrose after their designated training period. An unshifted control group received only access to 4% sucrose throughout training. The data obtained after 10 vs. 30 sessions of training were compared to the unshifted controls. The results showed that overtraining enhanced the cSNC effect relative to regular training, suggesting that licking was an action guided by the expectation of the current reward, rather than a habit. These results suggest that FNR induced by reward downshifts overcomes the development of a habit even after prolonged training.