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

Life Sciences Commons

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

Articles 1 - 11 of 11

Full-Text Articles in Life Sciences

Comparison Of Guekensia Demissa Populations Along A Nitrogen Loading Gradient In Narragansett Bay, Ri, Janis Hall Aug 2013

Comparison Of Guekensia Demissa Populations Along A Nitrogen Loading Gradient In Narragansett Bay, Ri, Janis Hall

Master's Theses, Dissertations, Graduate Research and Major Papers Overview

Anthropogenic eutrophication of coastal estuaries impacts these vital ecosystems by increasing primary production, hypoxic conditions, pathogen concentration, and greenhouse gas emissions, all of which are leading to the degradation of shorelines, disease transmission, and hypoxia-related fish kills. Narragansett Bay is a prominent feature of Rhode Island, making up over 500 km of coastline and acting as a watershed for over 2,000 square meters of land in both Massachusetts and Rhode Island. This estuary is important to both the economy of the state of Rhode Island and its fringing ecosystems are necessary for a healthy shoreline. The beaches of Narragansett ...


Dueling Scientists And Dueling Historians: Controversy Over The External History Of Germ Theory, Glenn Jones May 2013

Dueling Scientists And Dueling Historians: Controversy Over The External History Of Germ Theory, Glenn Jones

Honors Projects and Presentations: Undergraduate

Louis Pasteur and Félix Pouchet, two scientists studying the fermentation of organic media, engaged in debate concerning spontaneous generation before the French Académie des sciences in 1864. This instance of clashing paradigms is thought to be one of the most important moments in the historical development and establishment of the germ theory of disease. But was this confrontation an example of truth prevailing through purely scientific discourse, or were other external factors at play in determining the course of the debate? A review of the literature reveals a controversy about this controversy, where historians of science disagree concerning the extent ...


Investigating The Leaf Cuticle Of The Moss Physcomitrella Patens, Eric John Ricci May 2013

Investigating The Leaf Cuticle Of The Moss Physcomitrella Patens, Eric John Ricci

Master's Theses, Dissertations, Graduate Research and Major Papers Overview

To minimize water loss, the aerial parts of vascular land plants are covered with a hydrophobic layer called a cuticle. The cuticle typically consists of two major components: cutin and waxes. In contrast to vascular plants, research reports indicate that some primitive nonvascular plants, such as mosses, lack a cuticle. This study attempts to reconcile contradictory literature reports about the presence of a waxy cuticle on the leaves of the moss Physcomitrella patens.

Histochemical staining was utilized to investigate the presence of a cuticle on Physcomitrella leaves. Experiments employing dyes that stain hydrophobic substances were generally consistent with the presence ...


The Varied Roles Of Induced Plant Responses In Species Interactions, Justine B. Roths May 2013

The Varied Roles Of Induced Plant Responses In Species Interactions, Justine B. Roths

All Theses & Dissertations

In this review, I will discuss indirect species interactions that occur as a result of herbivore-induced trait changes in plants. Species interactions are at the very core of the field of ecology. In particular, plant–insect herbivore interactions are of central importance as these two groups together consist of over 75% of the macroscopic diversity on earth. Historically, research has focused on pair-wise direct interactions however, more recently, the importance of indirect interactions has been widely acknowledged. Indeed, indirect interactions may be as strong and as common as direct interactions. Indirect interactions have been actively investigated in plant–insect systems ...


Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye Jan 2013

Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye

Open Access Theses

Giant ragweed (Ambrosia trifida L.) is a competitive annual plant found in disturbed landscapes and is the most troublesome weed in Indiana and the US Corn Belt. It is one of the most common and problematic weeds in corn and soybean production. The introduction of herbicide glyphosate, N-(phosphonomethyl) glycine in early 1970's provided farmers with a better and low-cost tool to control weeds. The use of glyphosate drastically increased after the development of glyphosate resistant agronomic crops in 1996 and was use as a post-emergence selective herbicide. This led to overreliance and repeated use of glyphosate for weed ...


Likely Successors Of Ash Species In Response To The Emerald Ash Borer In Ohio Forests, Brian Michael Good Jan 2013

Likely Successors Of Ash Species In Response To The Emerald Ash Borer In Ohio Forests, Brian Michael Good

Browse all Theses and Dissertations

Invasive species have the capability to alter landscapes and change the composition of a forest in a very short time. The recent invasive pest, Agrilus planipennis, emerald ash borer, was unintentionally introduced to the United States via ship route to Michigan. The pest attacks and kills all five native ash species in Ohio. This study focused on an area in west central Ohio not yet affected by the borer. Ash centered plots were used to record all species and sizes (diameter at breast height) within a 5m radius of a central ash tree. Plots ranged in topography and all five ...


Flying Speed In Drosophila Melanogaster Selected For Fast Flight, Jess Wheeler Jan 2013

Flying Speed In Drosophila Melanogaster Selected For Fast Flight, Jess Wheeler

All Theses & Dissertations

The aim of this study was to quantify the increase in flying speed in two replicate lines of Drosophila melanogaster (AA1 and AA2), after approximately 520 generations of selection for fast flight in a wind tunnel.


Regulation Of Antigenic Variation In Trypanosoma Brucei, Imaan A. Benmerzouga Jan 2013

Regulation Of Antigenic Variation In Trypanosoma Brucei, Imaan A. Benmerzouga

ETD Archive

Trypanosoma brucei is a protozoan parasite that causes sleeping sickness in humans and nagana in cattle. When inside the mammalian host, T. brucei cells stay in extracellular spaces and regularly switch their surface antigen, Variant Surface Glycoprotein (VSG), to escape the host's immune responses. To ensure the effectiveness of VSG switching, T. brucei expresses a single type of VSG at any time exclusively from one of 20 identical VSG expression sites located next to the telomere. Monoallelic expression of VSG and VSG switching are important for T. brucei's pathogenesis. Our major goal is to understand the mechanisms of ...


Bioinformatic Analysis And In Vitro Expression Of Malaria Parasite Translocon And Ribonuclease Binding-Like Rhoptry Genes, Moses Z. Timta Jan 2013

Bioinformatic Analysis And In Vitro Expression Of Malaria Parasite Translocon And Ribonuclease Binding-Like Rhoptry Genes, Moses Z. Timta

ETD Archive

Malaria caused by the parasite Plasmodium, still remains a significant public health problem worldwide, due to lack of a vaccine and emerging drug and insecticide resistance, among malaria parasites and mosquito vectors, respectively. Rhoptry proteins of Plasmodium enable merozoite invasion of host erythrocytes. However, only a few of these proteins have been characterized. Thirty-six P. yoelii merozoite rhoptry proteins were identified as putative rhoptry proteins by proteome analysis. Some of these proteins have been characterized while others still remain an intense area of active research. Molecular characterization and understanding of these novel proteins may assist in vaccine development, design of ...


Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang Jan 2013

Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang

Scripps Senior Theses

Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding ...


Phylogeography Of The Malagasy Ant Species Odontomachus Coquereli, Jason Jackson Jan 2013

Phylogeography Of The Malagasy Ant Species Odontomachus Coquereli, Jason Jackson

Electronic Theses and Dissertations

Madagascar is an extremely diverse and geographically complex area boasting levels of endemism that blatantly raise questions about their origins. There is evidence that these endemics arose via insitu diversification during Madagascar's ~88 million year isolation, even though it was essentially in the middle of Gondwana with ample opportunity to acquire inhabitants. Madagascar's high levels of diversity and endemism make it an ideal location to study speciation, especially considering the evidence that such high levels speciation occurred in Madagascar itself. Several hypotheses have been formulated to relate the complex geography to genetic divergence, and thereby speciation. I explore ...