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2013

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Full-Text Articles in Life Sciences

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino Jan 2013

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino

UNF Graduate Theses and Dissertations

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its …


Nutrient Availability Affects Flowering Rate But Has Limited Influence On Morphology Of The Hooded Pitcher Plant, Sarracenia Minor., Justin M. Lemmons Jan 2013

Nutrient Availability Affects Flowering Rate But Has Limited Influence On Morphology Of The Hooded Pitcher Plant, Sarracenia Minor., Justin M. Lemmons

UNF Graduate Theses and Dissertations

Carnivorous plants perform as both producers and consumers. Botanical carnivory has evolved in sunny, moist, nutrient-poor environments, and the primary nutrient supplied by prey is proposed to be nitrogen. There is a trade-off between carnivorous and photosynthetic structures which corresponds to degree of carnivory expression and available nutrients. This study was conducted on the hooded pitcher plant, Sarracenia minor, which is a facultative wetland plant and Florida-threatened species. Sarracenia minor is considered a specialist myrmecophage and ants characterize the majority of attracted and captured prey. Ants not only provide nutritional benefit, but also protection against herbivory. A natural population …


Knockdown Of Vitellogenin By Rnai Increases Survivorship But Exhibits Similar Physiological Responses To Ovariectomy In Grasshoppers, Alicia G. Linquist Jan 2013

Knockdown Of Vitellogenin By Rnai Increases Survivorship But Exhibits Similar Physiological Responses To Ovariectomy In Grasshoppers, Alicia G. Linquist

UNF Graduate Theses and Dissertations

Reduced reproduction has been shown to increase lifespan in many animals, yet the mechanisms behind this trade-off are mostly unknown. A previous study has shown that in the lubber grasshopper, Romalea microptera, ovariectomized (OVX) individuals have a 30% increase in lifespan relative to controls (Sham). In a separate study, an increase in fat body mass and a halting of ovarian growth were seen upon reduction of vitellogenin transcript via RNAi (VgRNAi). These data suggest that VgRNAi increases lifespan through the trade-off between reproduction and longevity and animals with combined ovariectomy and VgRNAi, might show additive physiological responses. In this …


Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey Jan 2013

Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey

UNF Graduate Theses and Dissertations

Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning …


A Survey Of The Taxonomy Of The Cyanobacteria From Northeast Florida, Descriptions Of Novel Taxa, And An Investigation Into The Factors Which Influence The Epibenthic Cyanobacterial Community, Holly Stephanie Stocks Jan 2013

A Survey Of The Taxonomy Of The Cyanobacteria From Northeast Florida, Descriptions Of Novel Taxa, And An Investigation Into The Factors Which Influence The Epibenthic Cyanobacterial Community, Holly Stephanie Stocks

UNF Graduate Theses and Dissertations

Cyanobacteria are important components of the aquatic system, valued for their oxygen production, nitrogen fixation, and as the base of many aquatic food webs. This study investigated several aspects of cyanobacteria such as the diversity and response to nutrient enrichments. A survey of Northeast Florida was conducted between the years of 2010 and 2012; a total of 145 taxa were identified in freshwater habitats, such as springs, lakes, rivers, and retention ponds. While surveying the St. Johns River in Jacksonville, Florida, a novel Stigonematalean taxon was isolated and cultured. Subsequent morphological and genetic analyses indicate that this taxon is related …


Enzyme Activity In Wheat Breeding Lines Derived From Matings Of Low Polyphenol Oxidase Parents, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger Jan 2013

Enzyme Activity In Wheat Breeding Lines Derived From Matings Of Low Polyphenol Oxidase Parents, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Polyphenol oxidase (PPO) in grain plays a major role in time-dependent discoloration of wheat (Triticum aestivum L.) products, especially fresh noodles. Breeding wheat cultivars with low or nil PPO activity can reduce undesirable product darkening. The low PPO line PI 117635 was crossed to two low PPO wheats, IDO580 and ‘IDO377s’, to determine whether matings between wheats with low levels of grain PPO would result in complementation, such that lines with still lower or nil PPO would be generated. Progeny in a population derived from PI 117635/ IDO580 displayed no variation in PPO activity. In the F3:4 populations …


Arbuscular Mycorrhizal Fungi Differ In Their Ability To Regulate The Expression Of Phosphate Transporters In Maize (Zea Mays L.), Hui Tian, Rhae A. Drijber, Xiaolin Li, Daniel N. Miller, Brian J. Wienhold Jan 2013

Arbuscular Mycorrhizal Fungi Differ In Their Ability To Regulate The Expression Of Phosphate Transporters In Maize (Zea Mays L.), Hui Tian, Rhae A. Drijber, Xiaolin Li, Daniel N. Miller, Brian J. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Previous studies have found that some phosphate (Pi) starvation inducible transporter genes are downregulated and arbuscular mycorrhizal (AM) inducible Pi transporter genes are upregulated in maize roots associated with the fungus Glomus intraradices. However, little is known about the functional diversity of different AM fungal species in influencing the expression of Pi transporters in maize roots. Here, we studied the expression of two Pi transporter genes ZEAma:Pht1;3 (Pi starvation inducible) and ZEAma:Pht1;6 (AM inducible) in maize root colonized by different AM fungal inoculants. Non-mycorrhizal maize, maize colonized by Glomus deserticola (CA113), Glomus intraradices (IA506), Glomus mosseae (CA201), Gigaspora gigantea …


Genetic Dissection Of Yield And Its Component Traits Using High-Density Composite Map Of Wheat Chromosome 3a: Bridging Gaps Between Qtls And Underlying Genes, Sachin Rustgi, Mustafa N. Shafqat, Neeraj Kumar, P. Stephen Baenziger, M. Liakat Ali, Ismail M. Dweikat, B. Todd Campbell, Kulvinder Singh Gill Jan 2013

Genetic Dissection Of Yield And Its Component Traits Using High-Density Composite Map Of Wheat Chromosome 3a: Bridging Gaps Between Qtls And Underlying Genes, Sachin Rustgi, Mustafa N. Shafqat, Neeraj Kumar, P. Stephen Baenziger, M. Liakat Ali, Ismail M. Dweikat, B. Todd Campbell, Kulvinder Singh Gill

Department of Agronomy and Horticulture: Faculty Publications

Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed and were localized to narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366), total biomass (wPt2740-Xcfa2076), kernels/spike (KPS) (Xwmc664-Xbarc67), and Pseudocercosporella induced lodging ( …


The Essentials Of Economic Sustainability By John Ikerd [Book Review], Charles A. Francis Jan 2013

The Essentials Of Economic Sustainability By John Ikerd [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Essentials of Economic Sustainability is the latest challenging statement on innovative economic philosophy from an alternative opinion leader John Ikerd, retired agricultural economist from University of Missouri, Columbia (Columbia, Missouri, United States). His perspective is that accelerating changes surrounding us require more than small adaptations, but rather a thoughtful reconsideration of basic principles about how the world works and our role in this dynamic reality. Ikerd paraphrases the challenge of the 1988 Brundtland Report of the United Nations that we must design strategies ‘to meet the economic needs of the present without diminishing economic opportunities for the future’ (page 1). …


Estimating Crop Yield Potential At Regional To National Scales, Justin Van Wart, Kurt Christian Kersebaum, Shaobing Peng, Maribeth Milner, Kenneth Cassman Jan 2013

Estimating Crop Yield Potential At Regional To National Scales, Justin Van Wart, Kurt Christian Kersebaum, Shaobing Peng, Maribeth Milner, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

World population will increase 35% by 2050, which may require doubling crop yields on existing farm land to minimize expansion of agriculture into remaining rainforests, wetlands, and grasslands. Whether this is possible depends on closing the gap between yield potential (Yp, yield without pest, disease, nutrient or water stresses, or Yw under water-limited rainfed conditions) and current average farm yields in both developed and developing countries. Quantifying the yield gap is therefore essential to inform policies and prioritize research to achieve food security without environmental degradation. Previous attempts to estimate Yp and Yw at a global level have been too …


Soybean Seed Amino Acid Content Qtl Detected Using The Universal Soy Linkage Panel 1.0 With 1,536 Snps, Benjamin D. Fallen, Catherine N. Hatcher, Fred L. Allen, Dean A. Kopsell, Arnold M. Saxton, Pengyin Chen, Stella K. Kantartzi, P. B. Cregan, D. L. Hyten, Vincent R. Pantalone Jan 2013

Soybean Seed Amino Acid Content Qtl Detected Using The Universal Soy Linkage Panel 1.0 With 1,536 Snps, Benjamin D. Fallen, Catherine N. Hatcher, Fred L. Allen, Dean A. Kopsell, Arnold M. Saxton, Pengyin Chen, Stella K. Kantartzi, P. B. Cregan, D. L. Hyten, Vincent R. Pantalone

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is the primary source of meal used in animal feed in the U.S. However, few studies have been conducted to evaluate genomic regions controlling amino acid composition is soybean. Designing soybean seed compositions that will benefit animal production is essential. The objective of this study was to identify genomic regions controlling essential and non-essential amino acid composition in soybean seed proteins. To achieve this objective, 282 F5:9 recombinant inbred lines (RILs) developed from a cross of Essex × Williams 82 were used. Ground soybean seed samples were analyzed for amino acids and statistically …


Resource Allocation For Maximizing Prediction Accuracy And Genetic Gain Of Genomic Selection In Plant Breeding: A Simulation Experiment, Aaron Lorenz Jan 2013

Resource Allocation For Maximizing Prediction Accuracy And Genetic Gain Of Genomic Selection In Plant Breeding: A Simulation Experiment, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

Allocating resources between population size and replication affects both genetic gain through phenotypic selection and quantitative trait loci detection power and effect estimation accuracy for marker-assisted selection (MAS). It is well known that because alleles are replicated across individuals in quantitative trait loci mapping and MAS, more resources should be allocated to increasing population size compared with phenotypic selection. Genomic selection is a form of MAS using all marker information simultaneously to predict individual genetic values for complex traits and has widely been found superior to MAS. No studies have explicitly investigated how resource allocation decisions affect success of genomic …


The Clubroot Pathogen (Plasmodiophora Brassicae) Influences Auxin Signaling To Regulate Auxin Homeostasis In Arabidopsis, Linda Jahn, Stefanie Mucha, Sabine Bergmann, Cornelia Horn, Paul E. Staswick, Bianka Steffens, Johannes Siemens, Jutta Ludwig-Müller Jan 2013

The Clubroot Pathogen (Plasmodiophora Brassicae) Influences Auxin Signaling To Regulate Auxin Homeostasis In Arabidopsis, Linda Jahn, Stefanie Mucha, Sabine Bergmann, Cornelia Horn, Paul E. Staswick, Bianka Steffens, Johannes Siemens, Jutta Ludwig-Müller

Department of Agronomy and Horticulture: Faculty Publications

The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1) in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA) and transcription …


Unleashing The Potential Of The Root Hair Cell As A Single Plant Cell Type Model In Root Systems Biology, Zhenzhen Qiao, Marc Libault Jan 2013

Unleashing The Potential Of The Root Hair Cell As A Single Plant Cell Type Model In Root Systems Biology, Zhenzhen Qiao, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Plant root is an organ composed of multiple cell types with different functions.This multicellular complexity limits our understanding of root biology because -omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e., uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes), the root hair cell is an attractive …


The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy Oden, James R. Brandle Jan 2013

The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy Oden, James R. Brandle

Biology Publications

There are many opportunities for biodiversity conservation in organic farm systems. Successful and sustainable conservation efforts in organic systems, however, need to measure appropriate outcomes. In particular, data are needed on the breeding success of associated wildlife species. We measured nesting success of the American Robin (Turdus migratorius) in woodlands embedded within eight organic farms in eastern Nebraska. We modeled daily nest survival rate to identify land use and land cover patterns that optimize conservation of birds in organic farm systems. The percentage of a crop in the fields adjacent to linear woodlands best predicted daily survival rate. …


Revisiting The Fundamentals In The Design And Control Of Nanoparticulate Colloids In The Frame Of Soft Chemistry, Vuk Uskoković Jan 2013

Revisiting The Fundamentals In The Design And Control Of Nanoparticulate Colloids In The Frame Of Soft Chemistry, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents thoughts on some of the fundamental features of conceptual models applied in the design of fine particles in the frames of colloid and soft chemistry. A special emphasis is placed on the limitations of these models, an acknowledgment of which is vital in improving their intricacy and effectiveness in predicting the outcomes of the corresponding experimental settings. Thermodynamics of self-assembly phenomena illustrated on the examples of protein assembly and micellization is analyzed in relation to the previously elaborated thesis that each self-assembly in reality presents a co-assembly, since it implies a mutual reorganization of the assembling system …


Aberrant Proliferation In Cxcr7+ Endothelial Cells Via Degradation Of The Retinoblastoma Protein, Jennifer Totonchy, Jessica M. Osborn, Sara Botto, Lisa Clepper, Ashlee V. Moses Jan 2013

Aberrant Proliferation In Cxcr7+ Endothelial Cells Via Degradation Of The Retinoblastoma Protein, Jennifer Totonchy, Jessica M. Osborn, Sara Botto, Lisa Clepper, Ashlee V. Moses

Pharmacy Faculty Articles and Research

Angiogenesis is a critical factor in the growth and dissemination of solid tumors. Indeed, tumor vasculature is abnormal and contributes to the development and spread of malignancies by creating a hostile microenvironment. The alternative SDF-1/CXCL12 receptor, CXCR7, is frequently and specifically expressed in tumor-associated vessels. In this study, we examine the role of endothelium-expressed CXCR7 in tumor vascular dysfunction by specifically examining the contribution of CXCR7 to endothelial cell (EC) proliferation. We demonstrate that CXCR7 expression is sufficient to drive post-confluent growth in EC cultures. Further, we provide a novel mechanism for CXCR7-mediated proliferation via proteasomal degradation of the tumor …


Orientocreadium Batrachoides Tubangui, 1931 (Orientocreadiidae): The Only Trematode Parasite Of Clarias Gariepinus (Burchell, 1822) (Clariidae) From The Asi River (Southern Turkey), Tayha Tepe, Mehmet Cemal Oğuz, Mark C. Belk, Remzi Özgen Jan 2013

Orientocreadium Batrachoides Tubangui, 1931 (Orientocreadiidae): The Only Trematode Parasite Of Clarias Gariepinus (Burchell, 1822) (Clariidae) From The Asi River (Southern Turkey), Tayha Tepe, Mehmet Cemal Oğuz, Mark C. Belk, Remzi Özgen

Faculty Publications

Objective: Some information is available about the parasite fauna and incidence for Clarias gariepinus in Turkey, but digenean parasites have received little attention. The purpose of the study is to contribute to the parasite fauna of Turkey.

Methods: From 2007 to 2008, a total 63 Clarias gariepinus that were caught in the Asi River were purchased from the fish market in Hatay and brought on ice to the Parasitology Research Laboratory at Atatürk University. The fish were dissected. The obtained parasites were fixed with AFA, dyed with Mayer’s Carmalum, and mounted with Canada Balsam.

Results: Forty-eight fish were infected with …


2013 Weed Science Research Report – Blue Section, Ndsu Weed Science, Dept. Of Plant Sciences Jan 2013

2013 Weed Science Research Report – Blue Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2013. It includes work on corn and soybean crops and the management of several weeds in North Dakota.


2013 Weed Science Research Report – Gold Section, Ndsu Weed Science, Dept. Of Plant Sciences Jan 2013

2013 Weed Science Research Report – Gold Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2013. It includes work on sugarbeet and the management of several weeds in North Dakota.


2013 Weed Science Research Report – Green Section, Ndsu Weed Science, Dept. Of Plant Sciences Jan 2013

2013 Weed Science Research Report – Green Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2013. It includes work on small grains and the management of several weeds in North Dakota.


2013 Weed Science Research Report – Tan Section, Ndsu Weed Science, Dept. Of Plant Sciences Jan 2013

2013 Weed Science Research Report – Tan Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2013. It includes work on adjuvants and water quality and the management of several weeds in North Dakota.


2013 Weed Science Research Report – Yellow Section, Ndsu Weed Science, Dept. Of Plant Sciences Jan 2013

2013 Weed Science Research Report – Yellow Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2013. It includes work on several minor crops and the management of several weeds in North Dakota.


Solid-Phase Organic Matter Reduction Regulates Anaerobic Decomposition In Bog Soil, Jason K. Keller, Kimberly K. Takagi Jan 2013

Solid-Phase Organic Matter Reduction Regulates Anaerobic Decomposition In Bog Soil, Jason K. Keller, Kimberly K. Takagi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store globally significant amounts of carbon and are important sources of the greenhouse gas methane (CH4) to the atmosphere. However, for reasons which are not well understood, many peatland soils produce smaller amounts of CH4 than theoretically predicted, and carbon dioxide (CO2) produced during anaerobic decomposition in peatland soils cannot be accounted for by commonly measured microbial processes. Here we show that the reduction of solid-phase organic matter (i.e., humic substances) suppresses CH4 production in a bog soil and can be responsible for 33–61% of the total carbon mineralization in this soil. These results demonstrate that the reduction of …


Leaf Traits Within Communities: Context May Affect The Mapping Of Traits To Function, Jennifer L. Funk, William K. Cornwell Jan 2013

Leaf Traits Within Communities: Context May Affect The Mapping Of Traits To Function, Jennifer L. Funk, William K. Cornwell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The leaf economics spectrum (LES) has revolutionized the way many ecologists think about quantifying plant ecological trade-offs. In particular, the LES has connected a clear functional trade-off (long-lived leaves with slow carbon capture vs. short-lived leaves with fast carbon capture) to a handful of easily measured leaf traits. Building on this work, community ecologists are now able to quickly assess species carbon-capture strategies, which may have implications for community-level patterns such as competition or succession. However, there are a number of steps in this logic that require careful examination, and a potential danger arises when interpreting leaf-trait variation among species …


The Importance Of Female Choice: Evolutionary Perspectives On Constraints, Expressions, And Variations, David Frederick, Tania A. Reynolds, Maryanne L. Fisher Jan 2013

The Importance Of Female Choice: Evolutionary Perspectives On Constraints, Expressions, And Variations, David Frederick, Tania A. Reynolds, Maryanne L. Fisher

Psychology Faculty Books and Book Chapters

This chapter introduces the reader to some of the influential perspectives on female mate choice in human evolutionary biology, including parental investment theory. We then present two key theories in evolutionary psychology that have been applied to understand variations in women’s mating preferences and choices: sexual strategies theory and strategic pluralism theory. Although the importance of female choice has gained widespread acceptance in the biological sciences, the influence that female choice has on mating systems can be limited by many factors, such as control over mating decisions by parents and men’s control over women’s sexuality. Despite these constraints on female …


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 Jan 2013

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 …


Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Anita Dille, Frank Forcella, John Lindquist, Christy Sprague Jan 2013

Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Anita Dille, Frank Forcella, John Lindquist, Christy Sprague

Department of Agronomy and Horticulture: Faculty Publications

Robust predictions of weed seedling emergence from the soil seedbank are needed to aid weed management. A common seed accession (Illinois) of giant ragweed was buried in replicate experimental gardens over 18 site years in Illinois, Michigan, Kansas, Nebraska, Ohio, and South Dakota to examine the importance of site and climate variability by year on seedling emergence. In a nonlinear mixed-effects modeling approach, we used a flexible sigmoidal function (Weibull) to model giant ragweed cumulative seedling emergence in relation to hydrothermal time accumulated in each site-year. An iterative search method across a range of base temperature (Tb) …


Cancer Quasispecies And Stem-Like Adaptive Aneuploidy, Domenico Napoletani, M. Signore, Daniele C. Struppa Jan 2013

Cancer Quasispecies And Stem-Like Adaptive Aneuploidy, Domenico Napoletani, M. Signore, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we develop a theoretical frame to understand self-regulation of aneuploidy rate in cancer and stem cells. This is accomplished building upon quasispecies theory, by leaving its formal mathematical structure intact, but by drastically changing the meaning of its objects. In particular, we propose a novel definition of chromosomal master sequence, as a sequence of physically distinct whole or fragmented chromosomes, whose length is taken to be the sum of the copy numbers of each whole or fragmented chromosome. This fundamental change in the functional objects of quasispecies theory allows us to show that previously measured aneuploidy rates …


Phylogeography Of Notropis Nubilus (Ozark Minnow), Jason F. Dugan Jan 2013

Phylogeography Of Notropis Nubilus (Ozark Minnow), Jason F. Dugan

Dissertations and Theses @ UNI

Periodic glacial cycles beginning 2.6 million years ago to 10,000 years ago forced the repeated contraction, fragmentation, and expansion of the North American biota. In the upper Mississippi River basin three very different areas characterize the topography left by glaciations and still and influence the flora and fauna: Driftless Area, Paleozoic Plateau, and Iowan Surface. The Paleozoic Plateau is located in the northern part of the upper Mississippi River basin, and it is a unique geographical region situated in an area that straddles northeast Iowa, southeastern Minnesota, southwest Wisconsin, and northwest Illinois. This region was bypassed by the last glacial …