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Mechanisms Of Protective Humoral Immunity And Pathogenesis In Alphavirus Infection, Natasha Monir Kafai

Arts & Sciences Graduate Student Theses and Dissertations

Alphaviruses are enveloped, mosquito-transmitted, positive-sense RNA viruses of the Togaviridae family classified into Old and New World groups based on endemic regions and human disease characteristics. Old World alphaviruses, including chikungunya virus preferentially cause arthritogenic disease, whereas New World viruses like Venezuelan equine encephalitis virus (VEEV), Eastern equine encephalitis virus (EEEV), and Western equine encephalitis virus (WEEV) can cause neurological disease. Since the 1920s, VEEV has been responsible for major periodic outbreaks affecting hundreds of thousands of humans and equines in South and Central America. Expansion of mosquito vectors raises concern for possible VEEV reemergence. In addition, VEEV is a …

Mitochondrial Network Expansion And Loss During Oligodendrocyte Life And Death, Xhoela Bame

Dartmouth College Ph.D Dissertations

Oligodendrocytes are the myelinating cells of the central nervous system, known for modulating signal transmission, refining neural circuits, and providing metabolic support to axons. Oligodendrocytes are generated throughout life from oligodendrocyte precursor cells (OPCs) and are damaged or lost in demyelinating and neurodegenerative diseases and age-related pathologies. Thus, understanding the cellular checkpoints that occur during the generation and degeneration of oligodendrocytes is crucial for maintaining their population in health and recovering it in disease and aging.

Using high-resolution optical imaging, I have discovered a dynamic redistribution and subcellular partitioning of mitochondria during oligodendrogenesis. Mitochondria transiently expanded towards the differentiating OPC …

Novel Combination Therapies For Estrogen Receptor-Positive Breast Cancer Driven By Rational Molecular Mechanisms, Anneka Lila Johnson

Dartmouth College Ph.D Dissertations

Breast cancer (BC) is the most common non-keratinocyte cancer diagnosed in women in the United States with approximately 300,000 new cases diagnosed each year. Despite a myriad of treatment options, BC remains the second-most deadly cancer. Estrogen receptor-positive (ER+) BC comprises 60-70% of BC diagnoses and is treated with endocrine therapies that limit ER signaling. Despite endocrine therapy options, ~1/3 of patients experience recurrence within 10-20 years of diagnosis. Novel therapeutic strategies are required to limit BC recurrence-related morbidity and mortality.

Radiotherapy is used as an adjuvant treatment for ER+ BC patients prior to the use of endocrine therapy. Radiation …

Proteogenomic Analysis To Inform Causal Gene Prioritization For Human Disease, Daniel Western

Arts & Sciences Graduate Student Theses and Dissertations

Genome-wide association studies (GWAS) have been key in expanding our understanding of the genetic contributions to common diseases. However, these genetic associations frequently fail to clarify causal disease mechanisms, as they often fall in non-coding regions and are difficult to interpret. One solution is to perform a GWAS for the levels of a cellular trait, known as quantitative trait locus (QTL) mapping. Through methods such as colocalization, Mendelian Randomization, and transcriptome/proteome-wide association studies, the QTL variants can be compared to disease GWAS, identifying shared variation between cellular and disease traits. We can then prioritize cellular traits as potential causative, targetable …

Protocol For A Randomized Controlled Trial To Determine If Biomarkers Predict Response To A Pediatric Chronic Pain Symptom Management Program, Rona L Levy, Tasha B Murphy, Margaret M Heitkemper, Miranda A L Van Tilburg, Ann R Mcmeans, Jocelyn Chang, Cynthia Boutte, Katherine Lamparyk, Bruno P Chumpitazi, Robert J Shulman

Children’s Nutrition Research Center Staff Publications

Background/Objectives: Disorders of gut-brain interaction (DGBI), characterized by chronic abdominal pain and significant disability, affect 15-20% of children and adults and continue into adulthood in ~60% of cases. Costs for adults reach USD 30 billion per year, yet effective management strategies are elusive. Studies support using cognitive behavioral therapy (CBT), but abdominal pain only improves in ~40% of patients. Dietary management (low FODMAP diet; LFD) has also shown promise but it is effective in only a similar percentage of patients. Studies suggest that biologic factors (biomarkers) contribute to CBT response. Similarly, gut microbiome composition appears to influence abdominal pain …

Birds Of A Feather: An Integrated Outdoor-Based Bird Study P-3 Curriculum Guide, Erin A. Buzza

Masters Theses/Capstone Projects

In a post-pandemic world that places technology at the at the forefront, educators are searching for ways to help students connect with the natural world. This project aids teachers in tackling this challenge by using the study of birds as a motivation to engage students with the outdoors and local wildlife. To demonstrate how ornithology topics can be used as an integrated thematic unit, research regarding components of ecological literacy is presented. They include nature-based learning, outdoor learning, environmental education, and wildlife education. In addition to these pedagogies, the benefits of incorporating interdisciplinary learning within the classroom are also provided …

Genomic Structure Among Populations Of A Regionally Rare Perennial Plant Indicates The Need For Reevaluation Of Management Units, Cheyenne Moore, Angela J. Mcdonnell, Scott Schuette, Christopher T. Martine

Faculty Journal Articles

Conservation of rare species often relies on the delineation of management units and genomic tools can now be applied for this purpose. However, this is not as common on a local scale, where populations are often small and fragmented, despite the utility of informing conservation and management practice at the regional level. We use a genotyping by sequencing (GBS) approach to assess the perennial riparian plant species Baptisia australis (Fabaceae) in Pennsylvania, where the taxon is at the edge of its natural distribution and considered threatened. In this system, we investigate whether sampled subpopulations exhibit genetic structure. We find that …

Evaluation Of Phenotypic Antimicrobial Resistance From Bacterial Pathogen Isolates In Bison, Aleena M. Kallan

Honors Capstones

Bison, the American buffalo, are increasingly utilized for food consumption due to their high protein content. Shiga toxin-producing Escherichia coli (STEC) is an important food-borne pathogen that leads to severe clinical infections and becomes antimicrobial-resistant (AMR). Specifically, fluoroquinolone antibiotics can complicate human treatment when infected with resistant STEC. This study aims to determine the presence of STEC in bison reservoirs and their antimicrobial resistance. Fecal samples (n=320) from bison herds were collected, followed by specific culture-based isolation for STEC. Polymerase chain reaction (PCR) was employed for pathogen confirmation, with 25.6% prevalence. PCR targeting gene, gyrA (resistant to fluoroquinolone), was tested …

Rapid Identification Of Ambystoma Mexicanum Genotype Using Pcr Techniques, Elizabeth C. Dean

Undergraduate Honors Thesis Projects

Ambystoma mexicanum is an aquatic salamander species, commonly known as the axolotl, native to Mexico that is widely researched all over the world. In the wild, these salamanders have brown/black colored skin due to the presence of melanophores and xanthophores with shiny spots due to iridophores. In captivity, however, there are multiple different color morphs (phenotypes) of axolotls including leucistic, melanistic, and copper. Melanoid axolotls have black skin made by mostly melanophores, little xanthophores, and no iridophores. Melanistic genotypes such as melanoid and wild type color morphs are thought to be controlled by a single gene called Leukocyte Tyrosine Kinase …

Endemism Shapes Viral Ecology And Evolution In Globally Distributed Hydrothermal Vent Ecosystems, Marguerite V. Langwig, Faith Koester, Cody Martin, Zhichao Zhou, Samantha B. Joye, Anna-Louise Reysenbach, Karthik Anantharaman

Biology Faculty Publications and Presentations

Viruses are ubiquitous in deep-sea hydrothermal vents, where they influence microbial communities and biogeochemistry. Yet, viral ecology and evolution remain understudied in these environments. Here, we identify 49,962 viruses from 52 globally distributed hydrothermal vent samples (10 plume, 40 deposit, and 2 diffuse flow metagenomes), and reconstruct 5708 viral metagenome-assembled genomes, the majority of which were bacteriophages. Hydrothermal viruses were largely endemic, however, some viruses were shared between geographically separated vents, predominantly between the Lau Basin and Brothers Volcano in the Pacific Ocean. Geographically distant viruses shared proteins related to core functions such as structural proteins, and rarely, proteins of …

Prognostic Value Of Serum And Bronchoalveolar Lavage Fluid Galactomannan Levels In Invasive Aspergillosis: An 8-Year Experience At A Tertiary Cancer Center, Saliba Wehbe, Anne-Marie Chaftari, Ray Hachem, Hiba Dagher, Andrea Haddad, Ann Philip, Ying Jiang, Ramia Zakhour, Peter Bakht, Jishna Shrestha, Peter Lamie, Robin Sherchan, Jennifer Makhoul, Patrick Chaftari, Issam I Raad

Faculty, Staff and Student Publications

Background: Invasive aspergillosis (IA) is a life-threatening fungal infection that primarily affects immunocompromised individuals and has high morbidity and mortality rates, necessitating timely diagnosis and treatment. This study aimed to evaluate the prognostic utility of serum and bronchoalveolar lavage (BAL) fluid galactomannan levels, as well as galactomannan kinetics, in patients with IA.

Methods: We retrospectively reviewed the medical records of patients who were diagnosed with proven or probable IA from March 2016 to April 2024 at a tertiary cancer center. The collected data included patient characteristics, baseline and peak galactomannan levels in serum and BAL fluid, galactomannan trends, and …

Changes In Elephantgrass Plant Components With Maturity: 1. Percentage Dry Yield, P Mislevy, F G. Martin, M B. Adjei

IGC Proceedings (1977-2023)

Elephantgrass (Pennisetum purpureum Schum.) biomass can be a source of energy for tropical regions of the world because of its high dry matter production (Mislevy et al., 1986 ; Prine et al., 1987). Research has shown the production of energy (meth­ane) from biomass can be best understood through systems analysis methodology that integrates the availability of land, climate, production inputs, plant quality, etc. To assess avail­able technology and identify information gaps Biomass to Methane (Biomet) models have been developed to determine the impacts of basic growth processes in response to the crops environment (Mishoe et al., 1987). Biomass growth …

Teneurs En Constituants Parietaux Et En Matieres Azotees Des Ligneuz Fourragers D'Afrique Occidentale, A R. Kone, D Richard, H Guerin

IGC Proceedings (1977-2023)

Dans !es pays intertropicaux d'Afrique, l'elevage est surtout extensif et l'alimentation du betail est essentiellement basee sur le paturage nature! ou la strate ligneuse (arbres, arbustes) fournit des fourrages verts pendant la periode seche de l'annee, periode pendant laquelle le tapis herbace est sous forme de paille sur pied. Les ligneux sont done tres importants dans l'alimentation des ruminants domestiques et ii est necessaire d'en connaitre la composition chimique comme dans le cas des fourrages herbaces.

Evaluation Of Tree Legumes Species At Different Agroclimatic Zones Of Indonesia, Mas'ud Panjaitan, R Jessop, W W. Stur

IGC Proceedings (1977-2023)

The population of Indonesia is over 145 million and more than 56 % of them earn their living from agriculture (Bi. Stat. Ind., 1983). A major problem in the development of improved animal production has been the shortage of feed and the generally low nutritive value of tropical forages which limit livestock pro­duction in Indonesia (Asian Agriculture Survey, 1969). The production of feed of adequate quality for ruminants is an important consideration particularly for small holders. In many situations, nitrogen fixing legume trees can be used as a high protein feed supplement which improves the utilization of grasses and crop …

Valeur Nutritive D'Un Parcours Mixte A Acacia Cyanophylla, Atriplex Nummularia Et Medicago Arborea, Y Saadani, C Kayouli

IGC Proceedings (1977-2023)

II existe tres peu de donnees concernant la valeur nutritive des arbustes fourragers ; les rares etudes realisees en Tunisie ont porte surtout sur leur productivite, la charge animale et sur leur appetence (Hamrouni et Sarson, 1975; Ben Boubaker, 1985). L'objectif de ce travail est d'etudier la valeur nutritive des feuilles et brindilles d' Acacia cyanophylla, d' A triplex nummula­ria et de Medicago arborea ainsi que leur contribution dans la ration de caprins et d'ovins.

Utilization Of Native Mediterranean Fodder Trees By Dairy Goats, M Meuret

IGC Proceedings (1977-2023)

Few data are available on utilization of fodder trees and shrubs by lactating goats. In most cases, predictions of animal performances on the basis of recommendations obtained from standard reference trials, do not correspond with production results achieved on the farm. Using measurements in digesti­bility cages and on rangelands (chromic oxide marker), we recorded intake, apparent digestibility of diets and perform­ances of goats well used to rangelands and browsing fresh oak foliage (Quercus ilex and Quercus pubescens).

Phenols As Defensive Compounds In Birch (Betula Spp.) Metabolism Of Platyphylloside In Goats, Rabbits And Hares, R T. Palo, G Iason, P G. Knutsonn

IGC Proceedings (1977-2023)

Herbivores of the boreal forest like moose (Alces alces), hares (Lepus spp.) and birds (Tetranoidae) use birch as a major feed source. The tree is of medium preference to the animals and is low in available nutrients for most of the year. Apart from a high amount of lignified cell walls it also contains con­siderable amounts oflow molecular phenolic substances (Palo, 1984). A herbivore feeding on birch could thus be excepted to ingest large amounts of phenols. These are in general enough fat soluble to enter animal cells expected to ingest large amounts of …

Forage Production And Nutritive Value Of Leucanea Leucoephala In Southern Puerto Rico, L E. Tergas, R Milton Martinez, A V. Mendez Cruz

IGC Proceedings (1977-2023)

Leucaena leucocephala (L.) is a perennial schrub native to Mexico, Central America and the Caribbean, considered by investigators as a valuable forage legume because of its capacity for high production of digestible forage with a high protein content and tolerance to drought in semiarid regions with annual rainfall less than 1,000 mm (Skerman, 1977). The soil fertility of the semiarid region in southern Puerto Rico is adequate, but rainfall distribution is limiting for forage production and nutritive value. There is a demand for a suit­able and inexpensive source of high quality forage to improve the diet of the grazing cattle …

Effect Of Chemical Composition Of Roughages On Their Degradation Characteristics In The Rumen And Their Relationship With The < In Vitro > Organic Matter Digestibility, S Lopez, Dolores Carro, J S. Gonzales, Conchita Carpintero

IGC Proceedings (1977-2023)

The microbial fermentation of feeds in the reticulo-rumen allows ruminants the utilization of feeds with amounts of cell wall components, i.e. roughages. This rumen fermentation can be affected by the feed chemical composition and numerous techniques have been developed for its determination (Van Soest, 1982). The objective of the present work is to investigate the effect of the chemical composition of forages preserved under differ­ent methods on their degradation characteristics in the rumen determined by the « in sacco » method and to study the rela­tionships between the « in vitro» organic matter digestibility (IVOMD) and the rumen degradability.

Rumen Degradation Of Various Grass Species At Different Stages Of Growth, L J. Halliday

IGC Proceedings (1977-2023)

The species and cultivars sown depends on the farming sys­tem practiced. These developing swards are however, always invaded by native species including Agrostis, Paa and Festuca spp. which are generally referred to as 'weed' grasses. While the merits of Lolium spp. are well documented (Minson et al. 1960; Norton, 1982) information on the weed grasses is limited (Hag­gar, 1976). The potential for milk and meat production is dependent on the supply of utilizable nutrients to the animal's tissues which in turn is largely governed by the ability of rumen microbes to degrade plant cell walls. Although the degradability of dry …

Apparent Digestibility, Dynamics Of Rumen Fermentation And Sites Of Digestion Of Hays Of Leucaena Leucocephala (Lam) De Wit Cv. Peru, N M. Rodreiguez, I Borges

IGC Proceedings (1977-2023)

Protein deficiency, among others, is a common problem for livestock production in tropical regions. The use oflegumes has been suggested as a solution and Leucaena leucocephala has shown a great potential due to its capacity of nitrogen (N) fix­ation and dry matter (DM) production (NAS, 1984). However, very little is known about its nutritive value regarding its protein-energy balance and the process of digestion. The present work aimed the evaluation of the nutritive value of hays of Leucaena leucocephala cut at two stages of growth, through trials of apparent digestibility, dynamics of rumen fer­mentation and partition of digestion.

In Situ Degradation Of Cell Wall Neutral Sugars Of Normal And Brown Midrib Sorghum X Sudangrass Hybrids, K J. Moore, J O. Fritz, E H. Jaster

IGC Proceedings (1977-2023)

The nutritive value of forage for ruminants is limited by the digestibility of the complex polysaccharides cellulose and hemicellulose by rumen microbes. In grasses, the polysacchar­ide fraction of the cell wall is composed largely of polymers of neutral sugars and to a lesser extent uronic acids. Cellulose is a high molecular weight linear polymer of B-1 ➔ 4) linked D­gluco-pyranose units. Hemicellulose is a complex mixture of linear and branched-chain heteropolymers containing xylose, arabmose, mannose, galactose, glucose, and uronic acids (Van Soest, 1982). Lignification of the cell wall is a primary factor limiting the digestion of cell wall polysaccharides. Close …

Feed Evaluation Using Mobile Dacron Bags And Influences Of The Diet Composition, H Anzola, F N. Owens

IGC Proceedings (1977-2023)

The Mobile Nylon Bag (MNB) technique has been used successfully in protein nutrition studies with swine (Sauer et al., 1983) to determine amino acid availability from protein in specific feedstuffs. Canadian researchers also have tested this technique to predict site of digestion in ruminants (Kirkpatrick and Kennelly, 1987). Differences in small intestinal digestion may explain why animal responses differ to dietary protein sources which have similar ruminal escape values (Owens, 1986). The MNB holds promise to appraise the intestinal avail­ability of undegraded dietary protein though further develop­mel).t and testing are needed. The objective of this experiment was to examine the …

Prediction Of Digestibility And Protein From Growing Degree-Days For Crested And Western Wheatgrass, A` B. Franck, J F. Karn

IGC Proceedings (1977-2023)

Morphological development of crops, including cool-season forage grasses, is mainly a function of air temperature. Mor­phological development of plants has been predicted from ther­mal units expressed as growing degree-days (GDD) (Franck, 1985 ; Wang, 1960). The use of thermal units also provides a predictive measure for managing forages based on growth stages rather than dates. However, forage digestibility ��nd crude protein (CP) content generally decrease as morphological development and time increase (Kamstra, 1973 ; Kilcher and Troelsen, 1973). The relationship between thermal units and forage digestibility and CP has not been defined for crested and western wheatgrasses. The primary purpose …

Forage Quality Of Coast Cross 1 Bermudagrass On Intestinal Digestion Of Dietary Amino Acids, G Coto, Hanna Meier, Patrica Malgarez

IGC Proceedings (1977-2023)

The aim of this work was to study the digestibility of dietary amino acids found in the fibrous material, considering the qual­ity of the forage offered as the sole feeding source.

Sites Of Digestion Of Nitrogen Of Hays Made With The Tropical Legume Neonotonia Wightii, R R. Vera, E A. Pizarro, A Toscano, N M. Rodriguez

IGC Proceedings (1977-2023)

Tropical pasture species are of well-known lower quality than temperate species and there is evidence that some tropical legumes may contain antiquality factors that reduce further their nutritive value. Nonetheless, the nutritive value of Neonotonia wightii is generally moderate to high (Pizarro et al., 1983 ; Ribeiro et al., 1980), although there is little information on the factors that affect its quality, and none on the rate and sites of digestion within the gastrointestinal tract of ruminants. The aim of the work reported here was to examine the effect of age on the chemical composition, apparent digestibility and sites of …

Kinetic Study Of The Rumen Microbial Degradation Of Lucerne And Italian Ryegrass Observed By Scanning Electron Microscopy, E Grenet, J Jamot

IGC Proceedings (1977-2023)

For the same digestibility cell wall contents of legumes and grasses differ ; their histological structure is not the same and this may account for the differences in rumen degradation. We studied by scanning electron microscopy (SEM) the histologi­cal structure of these plants with regard to stages of maturity, and their kinetic degradation in the rumen.

Fermentation Characteristics Of Temperate Forage Stems Digested In Vitro, D R. Buxton

IGC Proceedings (1977-2023)

Digestion of herbage by ruminants is limited primarily by concentration of neutral-detergent fiber (NDF) in herbage and degradability of this cell-wall material. Because mature stems usually contain more NDF than immature stems or leaves the proportion of stems approaching maturity is normally' the dominant morphological factor that determines digestibility of herbage (Buxton and Hornstein, 1986). On the basis of digesti­bility, NDF can be divided into two fractions: potentially digestible NDF (PDNDF) and indigestible NDF (IDNDF; Mertens and Ely, 1982), which is not digested regardless of length of fermentation. Digestion of NDF can be characterized by a two-stage process involving a …

Nitrogen And Organic Matter Disappearance In The Digestive Tract Of Sheep Grazing Three Winter Foggages, W A. Van Niekerk, H H. Meissner, E B. Spreeth, I S. Conradie

IGC Proceedings (1977-2023)

Animal production in the tropics and subtropics is limited by poor intake. This results because of high cell wall content and poor digestibility of tropical forages (Minson & McLeod, 1970). During the dormant (winter) season these negative effects were exaggerated. Also, N declines resulting in a further reduction in intake. The questions addressed here were whether winter foggage of improved subtropical pastures could be ben­eficial and secondly, how three species adapted to the drier areas of South Africa, compare in this regard.

Nutritive Value Of Perennial Ryegrass Swards Grazed By Sheep In Autumn In The Uk, J A. Milne, H Dove, A M. Sibbald

IGC Proceedings (1977-2023)

A knowledge of the nutrient supply from grazed herbage for ewes in the autumn in N. Europe is required to predict the consequences for their subsequent reproductive performance. Herbage intake has been found to be positively related to sward height over this period at low sward heights but there is no information over a wider range of heights, on the amounts of non-ammonia nitrogen (NAN) available for absorption in the small intestine nor on the digestion of organic matter in the rumen. Experiments on frozen or artificially dried herbage harvested in the autumn have given variable results for the amounts …