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Full-Text Articles in Life Sciences

The Role Of The Circadian Clock In The Intestinal Epithelium During Health, Regeneration, And Tumourigenesis, Kyle Stokes Dec 2021

The Role Of The Circadian Clock In The Intestinal Epithelium During Health, Regeneration, And Tumourigenesis, Kyle Stokes

Electronic Theses and Dissertations

The Earth’s axial rotation subjects its surface to constant periods of light and dark, this is known as photoperiod. Many organisms have adapted their physiology in accordance with this environmental constant by generating 24h rhythms in their physiological functions; these are known as circadian rhythms. Circadian rhythms are controlled by an endogenous time-keeping mechanism known as the circadian clock. Over 40% of the genome in mice and over 80% of the genome in primates has been shown to have 24h rhythms in transcription. The disruption of circadian rhythms through shiftwork, jetlag, or exposure to light at night is associated with …


A Network-Based Approach For Computational Drug Repurposing On Cancer Data, Ann Reba, Thomas Alexander Oct 2021

A Network-Based Approach For Computational Drug Repurposing On Cancer Data, Ann Reba, Thomas Alexander

Electronic Theses and Dissertations

In this thesis, we are interested in finding the best drugs that can be repurposed for the disease and able to find the adverse effects such drugs that are FDA-Approved. Developing an effective drug can be a time-consuming and expensive crucible method. Network-based machine learning methods are used for predicting a given drug for A that can be used for B. It aims at finding new indications for already existing drugs and therefore increases the available therapeutic choices at a fraction of the cost of new drug development. The perturbation gene expression data corresponding to the MCF7 cell line was …


The Role Of The Nkr-P1b:Clr-B Inhibitory Axis In Nk Cell-Mediated Tumour Immunosurveillance, Abd El Aziz Hendy Oct 2021

The Role Of The Nkr-P1b:Clr-B Inhibitory Axis In Nk Cell-Mediated Tumour Immunosurveillance, Abd El Aziz Hendy

Electronic Theses and Dissertations

Natural killer (NK) cells are lymphocytes of the innate immune system which do not require prior priming to target infected or altered-self cells, such as tumour cells. The basic functions of NK cells include cytotoxicity and cytokine production. These cells possess numerous activating and inhibitory receptors which regulate their function based on a signalling balance. In mice, NK cells possess NKR-P1B inhibitory receptors which recognize the C-type lectin-related protein-b (Clr-b) ligand. This ligand is present on healthy self cells and may be used by cancer cells to evade NK cell effector functions. The disruption of the NKR-P1B:Clr-b axis has been …


An Integrated Approach To Understanding Anthonomus Eugenii Cano (Coleoptera: Curculionidae): An Exotic Pest Of Greenhouse And Field Pepper Crops, Diana Catalina Fernandez Oct 2021

An Integrated Approach To Understanding Anthonomus Eugenii Cano (Coleoptera: Curculionidae): An Exotic Pest Of Greenhouse And Field Pepper Crops, Diana Catalina Fernandez

Electronic Theses and Dissertations

Anthonomus eugenii, the pepper weevil is an important pest of cultivated pepper plants (Capsicum spp.). The weevil is originally from Mexico, but it is present in Central America, the Caribbean, and southern United States. Additionally, it was present and eradicated in the Netherlands, Italy, and western Canada in British Columbia. However, sporadic outbreaks occur during the pepper growing season in southern Ontario, which has prompted further investigation of its biology and management. My dissertation investigates the genetics, physiology and ecology of the pepper weevil and its implications for prevention, management, and potential establishment in southern Ontario. I investigated …


Does It Take A Community To Save A Species? Examining The Use Of Community Interactions To Restore Unionid Species At Risk, Roland Adriaan Eveleens Oct 2021

Does It Take A Community To Save A Species? Examining The Use Of Community Interactions To Restore Unionid Species At Risk, Roland Adriaan Eveleens

Electronic Theses and Dissertations

The conservation and restoration of freshwater ecosystems are complex. Knowledge from community ecology, conservation biology, and restoration ecology was integrated to interrogate the role of species interactions involving freshwater mussels (order Unionida) as keystone species. Freshwater mussels require host fish and provide ecosystem functions for other species throughout aquatic and riparian ecosystems, yet conservation efforts remain focused on focal mussel species or host fish associations. My thesis explored species co-occurrences within mussel and benthic macroinvertebrate community assemblages, and systematically reviewed the published literature to assess the breadth and reported effectiveness of mussel restoration. Community analyses confirmed species co-occurrences across environmental …


Parasites And Sexual Selection In A Sexually Dichromatic Toad, Nicole Erin Shangi Oct 2021

Parasites And Sexual Selection In A Sexually Dichromatic Toad, Nicole Erin Shangi

Electronic Theses and Dissertations

Parasitism is among the most common and successful life history strategies on Earth, leading to constant coevolution between parasites and hosts. Parasites continuously pressure hosts to evolve more effective parasite resistance, fueling interest in the relationships between expression of sexually selected host ornamentation and parasite resistance. By studying parasite-mediated sexual selection we gain unique insights into the evolution of animal traits. In this thesis, I attempt to further our understanding of a sexually dichromatic neotropical anuran by studying its parasites in the context of sexual selection. Firstly, in the General Introduction (Chapter 1), I reviewed important background information key to …


The Effects Of Probiotic Therapy On Stress Coping Styles Of Triploid Juvenile Farmed Chinook Salmon, Oncorhynchus Tshawytscha, Brendyn M. St. Louis Oct 2021

The Effects Of Probiotic Therapy On Stress Coping Styles Of Triploid Juvenile Farmed Chinook Salmon, Oncorhynchus Tshawytscha, Brendyn M. St. Louis

Electronic Theses and Dissertations

Triploid salmon – fish with three sets of chromosomes – are regularly used in aquaculture as they are functionally sterile and therefore avoid the decline in flesh quality associated with sexual maturation. However, triploid fish exhibit many immune, behavioural, and physiological drawbacks which reduce their condition and survival in aquaculture environments. My research examines the effects of probiotic treatment to promote behavioural and stress-related (termed ‘coping styles’) traits more suited for aquaculture environments in triploid fish with the ultimate goal of increasing fish yield. In this study, Chinook salmon (Oncorhynchus tshawytscha) crosses were developed in a 3x3 and 3x2 design, …


The Function And Evolution Of Wood-Warbler Flight Calls (Parulidae), Zach G. Gayk Oct 2021

The Function And Evolution Of Wood-Warbler Flight Calls (Parulidae), Zach G. Gayk

Electronic Theses and Dissertations

Animals produce vocalizations to communicate with territorial rivals, to communicate with potential mates, to alert others of predators, or to stay in contact with other animals. To date, little research has focused on the vocalizations that animals use to communicate during migration. Many birds produce flight calls, which are short calls given by migratory birds on the wing. The function of flight calls is poorly understood but they are thought to help migrants maintain contact with other individuals during movements between breeding grounds and wintering grounds. Across four data chapters in my dissertation, I investigated the function and evolution of …


The Effects Of Acid Rain Mitigation Efforts On The Behaviour-Dependent Movement Of Migrating Atlantic Salmon (Salmo Salar, L.) Smolts, Omar Salem Taboun Aug 2021

The Effects Of Acid Rain Mitigation Efforts On The Behaviour-Dependent Movement Of Migrating Atlantic Salmon (Salmo Salar, L.) Smolts, Omar Salem Taboun

Electronic Theses and Dissertations

Acidification has led to changes in the chemistry of fresh waters and has impacted the survival of Atlantic Salmon (Salmo salar), an endangered anadromous fish species. Liming, which has been implemented to restore freshwater ecosystems, has been demonstrated to restore a suitable pH for Atlantic Salmon, however, it remained unknown to what extent liming can restore the underlying behavioural traits and migration behaviour of smolts. We captured 116 smolts from two freshwater river treatments in Nova Scotia, Canada: acidified Little River (n=17) and lime-treated West River (n=99). We performed stream-side behavioural assays and discerned five behavioural metrics: (1) …


Examining The Links Between Environmental Variation, Foraging Behaviour And Foraging Success In An Arctic Seabird, Alyssa Eby Jul 2021

Examining The Links Between Environmental Variation, Foraging Behaviour And Foraging Success In An Arctic Seabird, Alyssa Eby

Electronic Theses and Dissertations

Arctic regions are experiencing increasing variability in inter-annual sea ice dynamics ultimately impacting marine Arctic ecosystems. Arctic-breeding seabirds, such as thick-billed murres (Uria lomvia) are thus likely to be negatively impacted by fluctuating environmental conditions through its influence on prey availability. Additional extrinsic factors (colony size and chick demand) and intrinsic factors (sex) are also likely to impact foraging behaviour and success of murres in combination with environmental conditions. First, we tested the effect of colony size on colony sensitivity to environmental change at two low Arctic colonies of varying sizes, Coats Island, Nunavut and Digges Island, Nunavut …