Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Life Sciences

Drivers Of Rickettsial Pathogen Transmission And Spillover In Local Tick Populations In Southeastern Virginia, Alexandra Cumbie Dec 2020

Drivers Of Rickettsial Pathogen Transmission And Spillover In Local Tick Populations In Southeastern Virginia, Alexandra Cumbie

Biomedical Sciences Theses & Dissertations

Cases of spotted fever group rickettsiosis are becoming more prevalent in the United States. In Virginia, there are three human-biting ticks which are largely responsible for the spread of rickettsial pathogens and the increase in disease cases. These species include Dermacentor variabilis, Amblyomma americanum, and Amblyomma maculatum; all of which are vectors of rickettsial agents to vertebrate hosts. These species are sympatric as adults and have the potential to share large and small mammal hosts. Their interactions on and off host and their associated rickettsiae were the focus of this dissertation work. Amblyomma americanum is the vector …


Exosomes In Transmission And Blocking Of Arthropod-Borne Flaviviral Infection And Pathogenesis, Wenshuo Zhou Apr 2020

Exosomes In Transmission And Blocking Of Arthropod-Borne Flaviviral Infection And Pathogenesis, Wenshuo Zhou

Biomedical Sciences Theses & Dissertations

Vector-borne diseases (VBDs) are human illnesses that are transmitted by vectors such as ticks, mosquitoes, and fleas. These arthropods transmit infectious pathogens such as viruses, protozoa, and bacteria, to humans during their blood-feeding. According to the estimation of the WHO, billions of people are affected by VBDs worldwide, and about 700,000 deaths are reported annually. Currently, very few reliable VBDs control approaches and vaccines available to treat various VBDs. Additionally, approaches to control arthropod’ proliferation and migration are difficult to develop. Furthermore, molecular determinants and mechanisms for the transmission are poorly understood. This work describes two studies identifying the novel …


Olfactory Behavioral Responses Of Mosquito Vectors To Select Attractants And Floral Scents As Related To Circadian Rhythms And Photoperiod Regimes, Bernadette A. Ferraro Apr 2020

Olfactory Behavioral Responses Of Mosquito Vectors To Select Attractants And Floral Scents As Related To Circadian Rhythms And Photoperiod Regimes, Bernadette A. Ferraro

Biomedical Sciences Theses & Dissertations

This dissertation discusses mosquito behavioral activities involving circadian rhythms defined as insect sensitivity to select of chemical volatiles that vary throughout the 24-hour day. Circannual rhythms occur over seasons varying in photoperiod, defined as the seasonal cycle of light and darkness. These cycles can be endogenously controlled by circadian clocks. The impetus for this research was initiated when reading about the neglected temporal dimension in the context of insect chemical ecology, including insect olfaction. It was proposed that sensitivity to odors does not change in general, but specific sensitivities could vary according to time of day. Chemical scents emitted by …