Diffusing wild type and sterile mosquitoes in an optimal control setting

This paper develops an optimal control framework to investigate the introduction of sterile type mosquitoes to reduce the overal moquito population. As is well known, mosquitoes are vectors of disease. For instance the WHO lists, among other diseases, Malaria, Dengue Fever, Rift Valley Fever, Yellow Fever, Chikungunya Fever and Zika. [http://www.who.int/mediacentre/factsheets/fs387/en/ ] The goal is to establish the existence of a solution given an optimal sterilization protocol as well as to develop the corresponding optimal control representation to minimize the infiltrating mosquito population while minimizing fecundity and the number of sterile type mosquitoes introduced into the environment per unit time. This paper incorporates the diffusion of the mosquitoes into the controlled model and presents a number of numerical simulations

Factors of Stress, Burnout, and Frustrations Experienced by Athletic Training Students

Purpose: College students are at a risk for increased levels of stress and burnout, and those enrolled in healthcare degree programs are more likely to experience higher levels due to balancing demanding roles. Our purpose was to assess sources of stress, burnout, and/or frustration in athletic training students (ATSs) of different academic standings. Methods: Data were collected through the use of an original, 33-question questionnaire. An inductive approach was used to analyze the data and multiple analyst triangulation and interpretive member checks were used to secure credibility. Results: 27 male and female ATSs from freshman, sophomore, junior, and senior classes from one institution voluntarily participated within this study. We were able to identify distinct themes of stress and burnout for each class of ATSs. Freshman reported concern for the time demand from the major and a desire to have more hands-on activity involved with their clinical education experiences. The sophomores reported feeling stressed regarding the expectation to retain information and the expectations to perform hands-on duties, as well as their ability to balance academic and clinical responsibilities. Challenging coursework, pressure during clinical experiences, and social conflicts appeared as themes for the junior ATSs. Finally, the seniors stated a fear of not achieving professional proficiency was a source of frustration. Conclusions and Recommendations: Based on our findings, efforts should be made to assist student time management practices, improve communication between preceptors and students, and make expectations of the athletic training program (ATP) faculty and preceptors clear. Such measures could help influence other positive changes within ATPs to improve the learning environment for ATSs

Strength Training: An Inquiry of Females Perceptions

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 10, 2023. While traditionally considered a male-dominated activity, women have increasingly embraced strength training. Although strength training has numerous physical and mental benefits to women, their subjective decision-making about using strength training have not been investigated thoroughly, especially using a unique methodology, Q, that is designed specifically to study subjectivity such as viewpoints and decision-making. There is limited research focused on females’ viewpoints about strength training. Capturing feelings and perceptions females have towards resistance training in an objective manner requires a specialized, mixed method called Q methodology [Q] that was created 90 years ago to scientifically study subjectivity. In Q, participants sort subjective statements about the topic into a grid to offer their internal viewpoints. Statistical analyses group similar sorts and provide empirical evidence to describe divergent viewpoints at a level usually reserved for qualitative studies. In this study, analyses revealed two distinct views: The Equipped Exercisers, who purposefully seek the benefits of exercise, and Road-blockers, who value exercise but implement constraints upon their participation. Understanding these views can facilitate expanding female participation in strength training through interventions

The local electronic structure of alpha-Li3N

New theoretical and experimental investigation of the occupied and unoccupied local electronic density of states (DOS) are reported for alpha-Li3N. Band structure and density functional theory calculations confirm the absence of covalent bonding character. However, real-space full-multiple-scattering (RSFMS) calculations of the occupied local DOS finds less extreme nominal valences than have previously been proposed. Nonresonant inelastic x-ray scattering (NRIXS), RSFMS calculations, and calculations based on the Bethe-Salpeter equation are used to characterize the unoccupied electronic final states local to both the Li and N sites. There is good agreement between experiment and theory. Throughout the Li 1s near-edge region, both experiment and theory find strong similarities in the s- and p-type components of the unoccupied local final density of states projected onto an orbital angular momentum basis (l-DOS). An unexpected, significant correspondence exists between the near-edge spectra for the Li 1s and N 1s initial states. We argue that both spectra are sampling essentially the same final density of states due to the combination of long core-hole lifetimes, long photoelectron lifetimes, and the fact that orbital angular momentum is the same for all relevant initial states. Such considerations may be generically applicable for low atomic number compounds.Comment: 34 pages, 7 figures, 1 tabl

Optimal control measures for a susceptible-carrier-infectious-recovered-susceptible malware propagation model

Purposing to lessen malware propagation, this paper proposes optimal control measures for a susceptible-carrier-infectious-recovered-susceptible (SCIRS) epidemiological model formed by a system of ordinary differential equations. By taking advantage of real-world data related to the number of reported cybercrimes in Japan from 2012 to 2017, an optimal control problem is formulated to minimize the number of infected devices in a cost-effective way. The existence and uniqueness of the results related to the optimality system are proved. Overall, numerical simulations show the usefulness of the proposed control strategies in reducing the spread of malware infections.- Fundação para a Ciência e Tecnologia, Grant/Award Number: UID/MAT/04106/2019 and UID/CEC/00319/201

Optimal fishery with coastal catch

In many spatial resource models, it is assumed that an agent is able to harvest the resource over the complete spatial domain. However, agents frequently only have access to a resource at particular locations at which a moving biomass, such as fish or game, may be caught or hunted. Here, we analyze an infinite time‐horizon optimal control problem with boundary harvesting and (systems of) parabolic partial differential equations as state dynamics. We formally derive the associated canonical system, consisting of a forward–backward diffusion system with boundary controls, and numerically compute the canonical steady states and the optimal time‐dependent paths, and their dependence on parameters. We start with some one‐species fishing models, and then extend the analysis to a predator–prey model of the Lotka–Volterra type. The models are rather generic, and our methods are quite general, and thus should be applicable to large classes of structurally similar bioeconomic problems with boundary controls. Recommedations for Resource Managers Just like ordinary differential equation‐constrained (optimal) control problems and distributed partial differential equation (PDE) constrained control problems, boundary control problems with PDE state dynamics may be formally treated by the Pontryagin's maximum principle or canonical system formalism (state and adjoint PDEs). These problems may have multiple (locally) optimal solutions; a first overview of suitable choices can be obtained by identifying canonical steady states. The computation of canonical paths toward some optimal steady state yields temporal information about the optimal harvesting, possibly including waiting time behavior for the stock to recover from a low‐stock initial state, and nonmonotonic (in time) harvesting efforts. Multispecies fishery models may lead to asymmetric effects; for instance, it may be optimal to capture a predator species to protect the prey, even for high costs and low market values of the predators

Deconvolving Instrumental and Intrinsic Broadening in Excited State X-ray Spectroscopies

Intrinsic and experimental mechanisms frequently lead to broadening of spectral features in excited-state spectroscopies. For example, intrinsic broadening occurs in x-ray absorption spectroscopy (XAS) measurements of heavy elements where the core-hole lifetime is very short. On the other hand, nonresonant x-ray Raman scattering (XRS) and other energy loss measurements are more limited by instrumental resolution. Here, we demonstrate that the Richardson-Lucy (RL) iterative algorithm provides a robust method for deconvolving instrumental and intrinsic resolutions from typical XAS and XRS data. For the K-edge XAS of Ag, we find nearly complete removal of ~9.3 eV FWHM broadening from the combined effects of the short core-hole lifetime and instrumental resolution. We are also able to remove nearly all instrumental broadening in an XRS measurement of diamond, with the resulting improved spectrum comparing favorably with prior soft x-ray XAS measurements. We present a practical methodology for implementing the RL algorithm to these problems, emphasizing the importance of testing for stability of the deconvolution process against noise amplification, perturbations in the initial spectra, and uncertainties in the core-hole lifetime.Comment: 35 pages, 13 figure