Population Biology Commons^™

Optimal Control Strategies For Infectious Diseases: A Numerical Simulation Approach, M. Abu Salek, Jannatun Nayeem, Romana Yesmin, M. Haider Ali Biswas, M. Humayun Kabir

Mathematical Modelling and Numerical Simulation with Applications

Various infectious diseases, such as Tuberculosis and Hepatitis B virus (HBV), caused by Mycobacterium bacteria and hepatitis B virus, respectively, pose serious threats worldwide. This paper examines the spread of these diseases using a mathematical model that incorporates control measures, including vaccination and awareness programs. We use a system of differential equations with control variables and apply Pontryagin's principle to determine optimal control strategies. The stability of the Disease Free Equilibrium (DFE) has been analysed and demonstrated to be both locally and globally asymptotically stable when the basic reproduction number remains below unity, thereby ensuring disease elimination. Furthermore, the Endemic …

Dynamical Analysis And Optimal Control Of The Mpox Transmission Model With Stratified Susceptibility, Tuhfatul Janan, Fatmawati Fatmawati, Cicik Alfiniyah, Santi Martini, Dipo Aldila, Agus Hasan

Mathematical Modelling and Numerical Simulation with Applications

This study develops a mathematical model of Mpox transmission that combines stratified susceptibility (low-risk and high-risk groups) with vaccinated and asymptomatically infected compartments. The analysis of the model begins with examining the well-posedness, boundedness, and nonnegativity conditions for the solutions. The local stabilities of the equilibria are examined through the Jacobian matrix and phase plane analysis, while the global stabilities are provided through Lyapunov functions. The estimated parameters are verified using epidemiological data on Mpox cases in the United States, with an MAPE of 2.20% and R_0 > 1, indicating that Mpox remains endemic. Sensitivity analysis indicates that the contact rate …

Optimal Control And Bifurcation Analysis Of A Predator–Prey Model With Self-Limiting Growth And Predator Disease, Dipo Aldila, Muhammad Akmal Fasya, Bevina D. Handari, Chidozie Williams Chukwu, Olumuyiwa James Peter

Mathematical Modelling and Numerical Simulation with Applications

We propose and analyze an eco-epidemiological predator–prey model that incorporates self-limitation and disease transmission within the predator population. The model is formulated as a system of ordinary differential equations describing logistic prey growth under the interspecific interaction with the predator. On the other hand, the predator population is divided into susceptible and infected classes, whose growth is constrained by prey availability. Three biologically relevant equilibria are identified: predator extinction, disease-free coexistence, and coexistence with endemic disease. The existence and stability of these equilibria are determined by key ecological and epidemiological thresholds, including the basic reproduction number. Using numerical continuation methods, …

Louisiana Species Of The Genus Xestia Hübner And The Genus Agnorisma Lafontaine, Vernon Antoine Brou Jr., Charlotte Dozar Brou

The Taxonomic Report of the International Lepidoptera Survey

We address three species of the genus Xestia Hübner recorded for the state of Louisiana: Xestia dilucida (Morrison), Xestia elimata (Guenée) and Xestia c-nigrum (Linnaeus), and we also address new state capture records for Agnorisma badinodis (Grote) and Agnorisma bollii in Louisiana.

Three Butterfly Genera Across The Central Texas Suture Zone, Qian Cong, Jing Zhang, Jinhui Shen, Leina Song, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

Genome-scale analyses of butterfly specimens across the Central Texas Suture Zone revealed that several taxa currently treated as subspecies exhibit genomic differentiation similar to that observed between species. Further investigation and genomic sequencing of additional specimens from across the ranges of these taxa support this conclusion and result in the following changes to nomenclature and taxonomy. Two new subspecies of Nymphalidae Rafinesque, 1815 are described: Asterocampa louisa monterra Grishin, ssp. n. (type locality in Mexico: Nuevo León) and Asterocampa clyton plana Grishin, ssp. n. (type locality in USA: Texas, Denton Co.). The following taxa are recognized as species, not subspecies: …

(Si16-21) Dynamical Study Of A Hassell-Varley Model With Nonlinear Harvesting And Fear Effect In Prey, Aditya Bhattacharya, Anindita Bhattacharyya

Applications and Applied Mathematics: An International Journal (AAM)

In this article, a one predator-one prey model incorporating Richards’ type growth in prey population, Hassell-Varley type functional response and Michaelis-Menten type prey harvesting is proposed and analyzed. Richards’ type growth with fear factor is incorporated in the proposed model to generalize the reduction effect of predator-induced fear on the rate of growth of the prey population. Positivity and boundedness of the system’s solutions are first established to ensure biological feasibility of the model. Existence and stability conditions of various types of equilibrium points associated with the model such as trivial equilibrium, axial (predator–free) equilibrium and coexistence equilibrium are obtained …

Trophic Structure And Mercury Bioaccumulation In Walleye And Yellow Perch In The Upper And Lower Red Lake Basins, Marissa Pribyl

Biology Graduate Theses

Mercury is a persistent global contaminant that biomagnifies through aquatic food webs, with dietary and environmental factors serving as the primary drivers of accumulation in fishes. Trophic structure and methylmercury dynamics in Walleye (ogaa; Sander vitreus) and Yellow Perch (asaawens; Perca flavescens) were investigated in the Upper and Lower Red Lake basins in Red Lake, Minnesota, during 2024-2025. Diets of Walleye and Yellow Perch were assessed through stomach dissections, and tissue samples from both species were analyzed for total mercury concentrations. Additional analyses included shiners (gigoozens; Notropis spp., Hudsonius spp.) along with a variety of freshwater fish and …

Observations Of Puddling Butterflies In Maryland, Usa, Aydin Örstan

The Taxonomic Report of the International Lepidoptera Survey

Six butterfly species in four families were observed puddling on damp soil, scat and carrion in various locations in Montgomery County, Maryland and on small islands in the Potomac River. Four species preferred damp soil to nearby mud, but the reason for this behavior is unknown. The presence of butterflies on small islands in the Potomac River is documented for the first time.

A Taxonomic Overview Of The Apodemia Mormo Complex From A Genomic Perspective, Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

Genomic analysis of the Apodemia mormo group (Riodinidae Grote, 1895 (1827)) specimens across the range from southwestern Canada through much of the western USA and northwestern Mexico, complemented by phenotypic examination and photographs of live individuals to inspect eye color, partitions the complex into eight species, one of which is proposed as new: Apodemia (Apodemia) apache Grishin, sp. n. (type locality in USA: Arizona, Apache Co.), and three elevated from subspecies of A. mejicanus: Apodemia (Apodemia) maxima (Weeks, 1891), stat. rest., Apodemia (Apodemia) deserti W. Barnes & McDunnough, 1918, stat. nov., and Apodemia ( …

Vultures, Bryan M. Kluever, Lee A. Humberg, Scott C. Barras

Wildlife Damage Management Technical Series

Fact sheet about vultures including information about human--wildlife conflicts, the vulture roost, affects on livestock, structures, human health and safety, identification of damage, management methods, legal considerations, and economics. Also included is an overview of the species.

Reproductive Biology Of Hybopsis Amblops, The Bigeye Chub, In The Flint River Of Alabama, Crissy L. Tarver, Bruce W. Stallsmith

Southeastern Fishes Council Proceedings

The purpose of this study was to establish a reproductive schedule and examine reproductive traits that shape fecundity of the Bigeye Chub, Hybopsis amblops Leuciscidae in the Flint River system of north Alabama. Traits associated with reproduction, growth, and maturation were assessed. Specimens were collected and examined monthly from August, 2013 until July, 2014. This Bigeye Chub population primarily spawns in April and May as indicated by gonadosomatic index (GSI), ovarian condition and clutch size. Mean GSI values began to rise in February, peaking in April and May at over 13% for females and 1.6% for males. There was a …

Decoupling Of Reproduction And Lifespan Trade-Off In Caenorhabditis Elegans Through Microbial Programming, Nora M. Villafuerte

LSU Master's Theses

The microbiome is increasingly recognized as a major regulator of host physiology. Using the Caenorhabditis elegans model, we investigated how natural commensal bacteria modulate host reproduction and lifespan through internal egg hatching, a phenotype in which retained embryos hatch within the maternal body. Screening strains from the CeMbio collection identified four focal strains Ochrobactrum BH3, Lelliottia JUb66, Pantoea BIGb0393, and Enterobacter CEent1 that significantly increased internal egg hatching during the late reproductive period. This contrasts with pathogenic bacteria, which induce early-onset internal egg hatching. Across the focal strains, worms exhibited reduced total brood size but an expanded reproductive window relative …

Assessing Localized Recovery And Synchrony Of An Endangered Wetland Species., Aiyana Reissman

Theses

The state and federally endangered light-footed Ridgway’s rail (LFRR; Rallus obsoletus levipes) is central to regional conservation, yet the drivers of its population fluctuations remain poorly understood. The fragmented nature of coastal wetlands in Southern California is threatening the existence of endemic species like the LFRR. Tidal inundation, severe storms, and overpredation threaten the survival of LFRR. This study addresses population fluctuations by analyzing the spatial and temporal drivers of LFRR populations to inform effective, site-specific management.

To do this, a 45-year (1980–2024) LFRR census data set across 16 wetlands throughout its range in California was synthesized. A multi-faceted …

Phylogeography, Fungal Host Specificity, And Fitness In The Corallorhiza Maculata Species Complex, Hana Thixton-Nolan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mycoheterotrophic plants exploit fungi for most or all nutritional needs, providing a compelling system to address the evolutionary consequences of genome reduction, population-level variation, and germination requirements. I am using the widespread Corallorhiza maculata species complex to address questions of genomic variation, fungal host specificity, morphological variation, and germination requirements across the broad geographic range from Mexico to northern North America. This complex contains C. bulbosa, C. macrantha, and C. mertensiana, the latter with three varieties (maculata, occidentalis, and mexicana). These taxa vary in flowering time, floral morphology, and fungal associations. However, the degree …

Relationship Between Ratio Of Hybrid Sunfish To Their Parent Species And Latitude, Maxwell Kattner

Journal of Earth and Life Science

Hybrid sunfish of the Lepomis genus make up a generally small but notable portion of the population of sunfish in Minnesota lakes. Hybrid sunfish play a significant role in freshwater ecosystems across the United States. They are both morphologically and behaviorally distinct in some ways and similar in other ways to their parent species, causing them to both fill and compete with their parent species for niches occupied by multiple Lepomis species. Despite this, the ratio of hybrid sunfish to their parent species has never been properly explored. This study observed if the ratio of hybrid sunfish to their parent …

A Review Of Mockingbird Song, Jacqueline Milander

Student Theses

The northern mockingbird (Mimus polyglottos) is known for its large repertoire and highly versatile song patterns.  It is a frequent mimic that is thought to continue learning sounds from its environment for the duration of its life.  Utilizing available song studies, this is a comprehensive review of northern mockingbird song, including learning, mimicry, repertoires, song dependence on seasonal cyclicity, and song function, particularly interspecific territoriality. While much discussion has surrounded the idea that northern mockingbirds engage in interspecific territoriality and that vocal mimicry functions in intersexual selection, this review provides new insight into the possibility that latitudinal differences among populations …

Genomic Signatures Of Decline And Recovery In An Endangered Bat, Myotis Grisescens, Marxe Altman-Orbach

Graduate Theses/Dissertations

Tremendous population declines may result in the loss of genetic diversity, which can, in turn, lead to reduced adaptive potential, overexpression of deleterious phenotypes, and further population declines. In this way, genetic drift from a severe demographic decline may ultimately lead to an extinction vortex. However, populations that avoid the loss of genetic diversity may remain viable, despite demographic crashes. Therefore, understanding genetic diversity is vital for assessing the conservation status of species that have undergone declines, and can even reflect the effectiveness of management actions. I investigated signatures of genetic bottlenecks in the gray bat (Myotis grisescens), …

Exploring Factors Mediating White-Nose Syndrome In Little Brown Bats, Carly R. Trujillo

Graduate Theses/Dissertations

The little brown bat (Myotis lucifugus) has experienced drastic population declines across North America due to the recent disease white-nose syndrome (WNS). Previous studies have identified putatively adaptive alleles (PAAs) that may give individuals a greater likelihood of survival. However, there could be geographic-specific adaptation, creating different adaptive landscapes. Additionally, there may be energetic trade-offs between disease survival and reproductive output, and it is not clear what the long-term survival outcomes for the species may be as a result. Long-term evolutionary outcomes are unclear because this species has a lifespan exceeding the arrival of WNS and is difficult …

Impacts Of Native And Nonnative Plant Species On Avian Community Diversity, Matty John Mackay, Steven Van Dang, Brandon Lee Corn

SPARK Symposium Presentations

Avian communities play an essential role in maintaining a healthy ecosystem dynamic by regulating insect populations, assisting in plant pollination, and seed dispersal. These contribute to the overall health of natural ecosystems and mitigate ecological disruptions that would arise in their absence. However, the introduction of non-native invasive plant species can interrupt the balance avian communities bring to ecosystems by reducing availability of food sources, altering habitat structures, increasing competition among individuals, and disrupting ecological relationships through rapid invasion of ecological spaces. Point count observations of birds at Shelby Bottoms Park, Nashville, Tennessee in areas dominated by non-native privet and …

Hidden In The Mist: Three New Species Of Salamanders Of The Genus Pseudoeurycea (Amphibia: Plethodontidae) From Oaxaca, Mexico, Eduardo A. Aguilar-Herrera, Salomón Sanabria-Urbán, Dulce L. Flores-Martínez, José David Gómez-Tapia, Misael Seba-Chacha, Leopoldo D. Vázquez-Reyes, Francisco A. Rivera-Ortíz, Patricia Ramírez-Bastida, Bruno Cortés-Ortiz, R. Alejandro Calzada-Arciniega, Etienne U. Avila-Ortega, Dónovan I. Víquez-Vega, Omar Hernández-Ordoñez, Christopher Blair, Víctor H. Jiménez-Arcos

Publications and Research

We describe three new species of lungless salamanders (Plethodontidae) in the genus Pseudoeurycea from Cerro Rabon, located on the eastern slopes of the Sierra Mazateca, Oaxaca, Mexico. This mid-elevation mountain, largely surrounded by warmer lowlands, remains relatively understudied. We present molecular and morphological evidence distinguishing the three new species from their congeners. According to our phylogenetic analysis, one of the new species belongs to the P. leprosa group, while the other two are members of the P. juarezi group. Notably, one of the new species represents the fourth worm salamander known from west of the Isthmus of Tehuantepec, and another …