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Palaeoecological Analysis Of The Decline In Stromatolite Abundance During The Ordovician Period, Noran Mhm El-Sherif

Browse all Theses and Dissertations

A stromatolite is a laminated benthic microbial deposit. Its uniqueness arises from being present since the Precambrian to the present. Stromatolites recorded a peak time during the Mesoproterozoic, subsequently they witnessed abrupt rises and falls in abundance with the steepest decline in the Ordovician period, from which it never recovered from. There is no consensus yet regarding the reasons behind the decline of stromatolites. Thus the decline of these microbial deposits remains an enigma. Additionally, a literature gap exists regarding the reasons that specifically led to the Ordovician decline. Accordingly, the focus of this literature-based MSc. thesis is to find …

Bacillus Thuringiensis: Transgenic Crops, Julie A. Peterson, John J. Obrycki, James D. Harwood

Department of Entomology: Faculty Publications

Bacillus thuringiensis (Bt) crops, genetically modified to express insecticidal toxins that target key pests of corn, cotton, rice, potato, and other crops, have been rapidly adopted and have become dominant fixtures in agroecosystems throughout the world. Due to the constitutive nature of Bt toxin expression, insecticidal proteins may be found in nearly all plant tissues, presenting multiple sources for Bt toxins to enter the environment, thus creating complex direct and indirect pathways for non-target organisms to be exposed to insecticidal proteins. The environmental impacts of Bt crops have been widely debated, although both benefits and risks do exist. Benefits of …

Food Webs And Food Sovereignty: Research Agenda For Sustainability, Charles A. Francis, Michelle Miller, Molly Anderson, Nancy Creamer, Michelle Wander, Jacob Park, Thomas Green, Brent Mccown

Department of Agronomy and Horticulture: Faculty Publications

Future food production will be constrained by the scarcity of fossil fuel and fresh water as well as increasing intensity and unpredictability of weather events and climate changes. The assurance of food security and equity for many consumers is complicated by concentration of ownership of land and other production resources, as well as a global corporate food systems model that is driven by profit at the expense of people and the environment. To assess potential alternatives to the contemporary global food chain, well focused research is needed on local food production and food webs where small- and midscale family farms …

Clean Up Our Home: Ellen Swallow Richards' Human Ecology And Emerging Environmental Ideologies, 1890-1915, Raeann Lillian Swanson

Honors Program Theses

In the late 1880s, after years of study and hard work, Ellen Richards began publishing her ideas on the home and the natural and urban environment. She called for the knowledge of basic scientific principles to be available to everyone. She believed that ignorance was holding back the public from altering their environment to make life healthier, happier, and safer. Over one hundred years later, Malcolm Gladwell wrote the book The Tipping Point. In his book, Gladwell explores the Broken Windows Theory that social scientists claimed they developed in the 1980s. The Broken Windows Theory states that there is a …

Putting Local Knowledge And Context To Work For Gunnison Sage-Grouse Conservation, Corrine Noel Knapp, James Cochran, F. Stuart Chapin Iii, Gary Kofinas, Nathan Sayre

Human–Wildlife Interactions

Successful conservation requires adequate understanding of focal species and ecology, practices that may assist species survival, and a community of people willing and able to conserve the species. For many species at risk, we operate with imperfect knowledge in complex conservation contexts. In this case study involving the Gunnison sage-grouse (Centrocercus minimus), we interviewed 26 community-defined local experts, including both those with and without related academic degrees, to assess the utility of local knowledge for understanding and informing conservation opportunities.This project suggests several benefits of integrating local knowledge that apply specifically to rare and endemic populations, including the …

Response Of A Small Population Of Greater Sage-Grouse To Tree Removal: Implications Of Limiting Factors, S. Nicole Frey, Rachel Curtis, Kevin Heaton

Human–Wildlife Interactions

In Utah, greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) range has been reduced to 50% of what is considered historical availability due to habitat degradation and loss. In an effort to improve sage-grouse habitat in southern Utah, the U.S. Bureau of Land Management (BLM) conducted a tree-removal treatment in 2005. We conducted a study to determine if (a) the tree-removal treatment was effective at creating new sage-grouse habitat, and (b) if characteristics of used habitat were similar to those reported in previous literature. The treatment resulted in increased abundance of grasses and forbs. Additionally, shrub percentage cover and height …

Factors Influencing Survival And Productivity Of Pronghorn In A Semiarid Grass-Woodland In East-Central New Mexico, Louis C. Bender, Jon C. Boren, Heather Halbritter, Shad Cox

Human–Wildlife Interactions

Pronghorns (Antilocapra americana) are an important source of revenue and recreation for property managers throughout New Mexico, but have been declining in number. We documented body condition, survival, production of fawns, and trends in population size of pronghorns on the Corona Range and Livestock Research Center (CRLRC), a working research ranch and wildlife enterprise located in east-central New Mexico, from 2006 through 2011. Accrual of all indices of condition and size of both adult female and adult male pronghorns was positively associated with precipitation during June to July, August to September, and annually. Annual survival rates of females …

Evaluation And Monitoring Of Ash (Fraxinus Spp.) Tolerant To Long-Term Emerald Ash Borer (Agrilus Planipennis [Coleoptera: Buprestidae]) Exposure, Kathryn G. Hietala

Dissertations, Master's Theses and Master's Reports - Open

Invasive insects that successfully establish in introduced areas can significantly alter natural communities. These pests require specific establishment criteria (e.g. host suitability) that, when known, can help quantify potential damage to infested areas. Emerald ash borer (Agrilus planipennis [Coleoptera: Buprestidae]) is an invasive phloem-feeding pest which is responsible for the death of millions of ash trees (Fraxinus spp. L.). Over 200 surviving ash trees were previously identified in the Huron-Clinton Metroparks located in southeast Michigan. Trees were assessed over a four year period and a hierarchical cluster analysis was performed on dieback, vigor, and presence of signs and …

Computational Prediction Of The Sporulation Network In Clostridium Thermocellum, Changyi Jiang

Dissertations, Master's Theses and Master's Reports - Open

Sporulation is a process in which some bacteria divide asymmetrically to form tough protective endospores, which help them to survive in a hazardous environment for a quite long time. The factors which can trigger this process are diverse. Heat, radiation, chemicals and lacking of nutrition can all lead to the formation of endospores. This phenomenon will lead to low productivity during industrial production. However, the sporulation mechanism in a spore-forming bacterium, Clostridium theromcellum, is still unclear. Therefore, if a regulation network of sporulation can be built, we may figure out ways to inhibit this process. In this study, a …

Cancer Risk Analysis By Fuzzy Logic Approach And Performance Status Of The Model, Atinç Yilmaz, Kürşat Ayan

Turkish Journal of Electrical Engineering and Computer Sciences

Cancer is the leading life-threatening disease for people in today's world. Although cancer formation is different for each type of cancer, it has been determined by studies and research that stress also triggers cancer types. Early precaution is very important for people who have not fallen ill yet with a disease like cancer that has a high mortality rate and expensive treatment. With this study, we expound that the possibility of developing such disease may be decreased and people could take measures against it. For the 3 cancer types selected as pilot work by introducing a fuzzy logic model, the …

Heavy Metal Pollution In The Paso Del Norte Region:Historical Reconstruction And Source Interpretation, Eugenia G. Shekhter

Open Access Theses & Dissertations

A unique and complex situation of heavy metal pollution arose in the El Paso del Norte region, one of the largest and oldest metropolitan areas on the US-Mexican border. This region with its complex topography is home to more than 2.2 million people sharing the same environment. Although many studies have been conducted in the region to identify the sources of environmental contamination, the cumulative history of heavy metal pollution is still incomplete. In order to identify the patterns of heavy metal dispersion and to test the hypothesis that the American Smelting and Refining Company (ASARCO) was a considerable contributor …

Lead And Associated Heavy Metal Distribution In Ciudad Juarez, Mexico, Samia Elfituri Grimida

Open Access Theses & Dissertations

Concern over the extent and sources of heavy metals exposure has arisen worldwide since their significant effects have been discovered in the environment. There is general agreement that research is needed to examine the residual lead and its association to heavy metals contamination in soil and quantify the health hazards. This research was directed to quantify and document the geographic distribution of lead and associated heavy metals concentration in Ciudad Juarez, Mexico. Lead, cadmium, chromium, zinc, and copper were selected to analysis. The soil samples used in this research were collected during a previous Encountors Binational Community Lead Study (RO1ES …

Impact Of Cerium Oxide Nanoparticles On Cilantro (Coriandrum Sativum), Maria Isabel Morales

Open Access Theses & Dissertations

Studies have shown that plants exposed to ENPs suffer different types of stress. Other studies have revealed that plants can take up and accumulate CeO2 NPs without modification. Thus, these NPs could enter the food chain through edible plants, posing a threat for human health. Cilantro (Coriandrum sativum) is a worldwide culinary and medicinal plant consumed either as a fresh herb or a spice. In this research, cilantro plants were germinated and cultivated for 30 days in organic soil treated with CeO2 NPs at concentrations varying from 0 to 500 mg kg!1. Subsequently, plant organs were analyzed by using spectroscopic …

Insects As Indicators Of Environmental Stress, De Anna Estella Beasley

Theses and Dissertations

In the face of climate change-related events and anthropogenic disturbances, understanding the impacts of these events on species richness, abundance and distribution is important for us to mitigate biodiversity loss and better predict consequences for the environment and for human life. Insects are excellent models for understanding the consequences of environmental stress due to the sensitivity of their development and behavior. The overall focus of my dissertation research is the investigation of fluctuating asymmetry and oviposition behavior as indicators of environmental stress. My research includes a meta-analysis of published literature, and empirical research that was part of a collaborative initiative …

Characterization Of The Role Of Fro6 In Metal Homeostasis In Arabidopsis Thaliana, Margo Ellen Maynes

Theses and Dissertations

Iron deficiency is the most common human nutritional disorder in the world today, affecting approximately 2 billon people worldwide, almost a third of the world's population. For most of the world's population, plant foods serve as the major source of dietary iron. One approach that may contribute towards the solution of iron deficiency is the development of crop plants that contain higher levels of bioavailable iron. This project focuses on FRO6, a ferric chelate reductase in Arabidopsis thaliana that is thought to reduce apoplastic iron for transport across the plasma membrane in leaf cells. We hypothesize therefore that FRO6 controls …

Front Matter

The Synapse: Intercollegiate science magazine

No abstract provided.

Issue 3

The Synapse: Intercollegiate science magazine

No abstract provided.

Eat Strong: Diet And Nutrition, Helen Rich

The Synapse: Intercollegiate science magazine

No abstract provided.

Sriracha And The Science Of Pain, Weelic Chong

The Synapse: Intercollegiate science magazine

No abstract provided.

Dark Matter, Rachel Budker

The Synapse: Intercollegiate science magazine

No abstract provided.

Chiropracty: Medicine Or Mysticism?, Connor Mccleskey

The Synapse: Intercollegiate science magazine

No abstract provided.

Initiation And Continuation Of Randomized Trials After The Publication Of A Trial Stopped Early For Benefit Asking The Same Study Question: Stopit-3 Study Design, Gabriela J. Prutsky, Juan Domecq, Patricia J. Erwin, Matthias Briel, Victor M. Montori, Elie A. Akl, Joerg J. Meerpohl, Dirk Bassler, Stefan Schandelmaier, Stephen D. Walter, Qi Zhou, Pablo Coello, Lorenzo Moja, Martin Walter, Kristian Thorlund, Paul Glasziou, Regina Kunz, Ignacio Ferreira-Gonzalez, Jason Busse, Xin Sun, Annette Kristiansen, Benjamin Kasenda, Osama Qasim-Agha, Gennaro Pagano, Hector Pardo-Hernandez, Gerard Urrutia, Mohammad Murad, Gordon Guyatt

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Randomized control trials (RCTs) stopped early for benefit (truncated RCTs) are increasingly common and, on average, overestimate the relative magnitude of benefit by approximately 30%. Investigators stop trials early when they consider it is no longer ethical to enroll patients in a control group. The goal of this systematic review is to determine how investigators of ongoing or planned RCTs respond to the publication of a truncated RCT addressing a similar question.

Methods/design

We will conduct systematic reviews to update the searches of 210 truncated RCTs to identify similar trials ongoing at the time of publication, or started …

Meat-Wise Eating Habits, J. Haycock, K. Anderson, Roslynn Brain

Environment and Society Faculty Publications

Whether from a cow, pig, bird, fish, or other domestic or game animal, meat is universally enjoyed as part of the cultural culinary experience. It is also an excellent source of protein, which is important for a healthy body. Many people who eat meat, however, are not aware of the impact their consumption has on the environment. This guide provides a set of quick facts and action tools to make wiser choices concerning meat consumption.

Osmb Ais Funds Final Report: Task 1 Boat Ramp Monitoring For New Zealand Mud Snails, Valance Brenneis, Samuel Cimino, Angela L. Strecker

Center for Lakes and Reservoirs Publications and Presentations

The New Zealand mud snail (Potamopyrgus antipodarum; NZMS) is an invasive species found in a variety of ecosystems in Oregon, including brackish estuaries, heavily used recreational rivers, and highly trafficked coastal freshwater lakes. NZMS are an invasive species of concern because once established, they may out-compete native invertebrate grazers, such as native insect larvae that provide important food resources for fish, and NZMS themselves provide little nutritional value. Monitoring for the presence and population density of NZMS was performed at boat ramps located along several water bodies in 2006 – 2007. These water bodies were then re-sampled during the summer …

Application Of Glycyrrhiza Glabra Root As A Novel Adsorbent In The Removal Of Toluene Vapors: Equilibrium, Kinetic, And Thermodynamic Study, Fazel Mohammadi-Moghadam, Mohammad Mehdi Amin,, Mehdi Khiadani, Fariborz Momenbeik, Heshmatollah Nourmoradi, Mohammad Sadegh Hatamipour

Research outputs 2013

The aim of this paper is to investigate the removal of toluene from gaseous solution through Glycyrrhiza glabra root (GGR) as a waste material. The batch adsorption experiments were conducted at various conditions including contact time, adsorbate concentration, humidity, and temperature. The adsorption capacity was increased by raising the sorbent humidity up to 50 percent. The adsorption of toluene was also increased over contact time by 12 h when the sorbent was saturated. The pseudo-second-order kinetic model and Freundlich model fitted the adsorption data better than other kinetic and isotherm models, respectively. The Dubinin-Radushkevich (D-R) isotherm also showed that the …

Weather Patterns Associated With Green Turtle Hypothermic Stunning Events In St. Joseph Bay And Mosquito Lagoon, Florida, Kelsey Roberts

USF Tampa Graduate Theses and Dissertations

January of 2010 brought record-breaking cold temperatures to Florida. Such freeze events can upset vulnerable populations of marine life and other species that rely on stable water temperatures. Sea turtles are one group of species that are particularly susceptible to abrupt drops in water temperature. When water temperatures drop below 10°C, a mass hypothermic stunning, or cold-stunning, event for sea turtles can be expected, with many debilitated turtles washing onshore with a very limited time window to be rehabilitated (Foley et al. 2007). The species of sea turtle that appears to cold-stun with the most frequency is the green turtle, …

Terpenoids, Essential Oil Composition, Fatty Acid Profile, And Biological Activities Of Anatolian Salvia Fruticosa Mill., Gülaçti Topçu, Mehmet Öztürk, Tuba Kuşman, Ayşe Asli Barla Demi̇rkoz, Ufuk Kolak, Ayhan Ulubelen

Turkish Journal of Chemistry

The hexane and dichloromethane extracts, obtained by re-extraction of the methanol extract of Salvia fruticosa Mill., afforded 7 diterpenoids (carnosol, carnosic acid, carnosic acid 12-methyl ether, rosmadial, isorosmanol, ferruginol, and manool), 4 triterpenoids (\alpha -amyryltetracosanoate, oleanolic acid, ursolic acid, and erythrodiol), a steroid (3-acetylsitosterol), and a flavone (salvigenin). The galls (apples) of the collected plant were separately extracted with hexane to afford fatty acids composed mainly of oleic acid (29\%), palmitoleic acid (29\%), and stearic acid (23.20\%), which exhibited high anticholinesterase activity, particularly against BChE. The essential oil, obtained from the aerial parts of the plant, exhibited high AChE inhibitory …

Do Non-Response Follow-Ups Improve Or Reduce Data Quality?: A Review Of The Existing Literature, Kristen Olson

Department of Sociology: Faculty Publications

The paper systematically reviews existing literature on the relationship between the level of effort to recruit a sampled person and the measurement quality of survey data. Hypotheses proposed for this relationship are reviewed. Empirical findings for the relationship between level of effort as measured by paradata (the number of follow-up attempts, refusal conversion and time in the field) and question-specific item non-response rates, aggregate measures of item non-response rates, response accuracy and various measurement errors on attitudinal questions are examined through a qualitative review.

Determination Of Copper Speciation, Bioavailability And Toxicity In Saltwater Environments, Tara N. Tait

Theses and Dissertations (Comprehensive)

The speciation of copper plays a strong role in determining bioavailability and toxicity upon copper exposure in marine environments. Specifically, natural organic matter (NOM) can complex with copper, influencing speciation and decreasing bioavailability. The aim of this research was to determine accurate copper speciation values using literature and new techniques and applying the techniques that reflect the most accurate speciation values to investigate the influence of NOM quantity and quality on copper speciation and toxicity. The results from this study will have implications on the development of a marine Biotic Ligand Model (BLM). Free copper was measured using a flow-through …

Phosphorus Cycling In The Sargasso Sea: Investigation Using The Oxygen Isotopic Composition Of Phosphate, Enzyme-Labeled Fluorescence, And Turnover Times, Karen Mclaughlin, Jill A. Sohm, Gregory A. Cutter, Michael W. Lomas, Adina Paytan

OES Faculty Publications

Dissolved inorganic phosphorus (DIP) concentrations in surface water of vast areas of the ocean are extremely low (<10 nM) and phosphorus (P) availability could limit primary productivity in these regions. We explore the use of oxygen isotopic signature of dissolved phosphate (δ¹⁸O_PO4) to investigate biogeochemical cycling of P in the Sargasso Sea, Atlantic Ocean. Additional techniques for studying P dynamics including ³³P-based DIP turnover time estimates and percent of cells expressing alkaline phosphatase (AP) activity as measured by enzyme-labeling fluorescence are also used. In surface waters, δ¹⁸O_PO4 values were lower than equilibrium by 3–6%, indicative of dissolved organic phosphorous (DOP) remineralization by extracellular enzymes. An isotope mass balance model using a variety of possible combinations of …