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Articles 1 - 14 of 14

Full-Text Articles in Life Sciences

Molecular And Morphological Variation Among Populations Of Pediomelum Tenuiflorum (Pursh) A.N. Egan (Fabaceae) In Nebraska, Usa, Chauncey L. Kellar Jr., Roxi Kellar Jul 2019

Molecular And Morphological Variation Among Populations Of Pediomelum Tenuiflorum (Pursh) A.N. Egan (Fabaceae) In Nebraska, Usa, Chauncey L. Kellar Jr., Roxi Kellar

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Individuals of Pediomelum tenuiflorum, “wild alfalfa”, from disjunct populations in Nebraska vary extensively in their overall gestalt. Those in the western and central part of the state have a very slender growth habit, with thin stems and few, small flowers; whereas, those in the southeast have a very robust growth habit with heavy-looking stems and many tightly clustered flowers. For nearly 200 years, taxonomists have alternated between splitting P. tenuiflorum into two species, with the many-flowered morphotype named P. floribundum, and lumping all the morphological variants into one species as they are now. In this study, we investigated morphological and ...


Beef Production Systems In The Nebraska Sandhills, Mckay Erickson Jun 2019

Beef Production Systems In The Nebraska Sandhills, Mckay Erickson

Theses and Dissertations in Animal Science

Four studies were conducted to determine the effectiveness of improving production systems of beef cattle in the Sandhills region of Nebraska. These studies were to determine impacts of modified estrus synchronization protocols, genomic testing heifer calves for longevity, and evaluation of 2 differing calving systems (March or May) for improving biological outcome and improved production. Experiment 1 utilized 180 yearling heifers to determine the effectiveness of a second dose of prostaglandin F(PGF) with those females not expressing estrus after an initial 14 d MGA-PG estrus synchronization protocol. The treatment of PGF did increase estrus expression, but did not ...


Addressing The Challenges Facing Wheat Production: Nebraska And International Breeding Efforts, Sarah Blecha May 2019

Addressing The Challenges Facing Wheat Production: Nebraska And International Breeding Efforts, Sarah Blecha

Doctoral Documents from Doctor of Plant Health Program

Bread wheat, Triticum aestivum L., provides 20 percent of the global daily calorie intake. It is the third most important food crop, after rice and corn. Biotic challenges significantly reduce wheat yield; chemical control can be a solution but can be cost prohibitive for subsistence farmers. For many farmers, genetic resistance to biotic stresses can be the most cost effective solution.

The International Center for Agricultural Research in the Dry Areas (ICARDA) and the Nebraska Small Grains Breeding Program have been addressing these wheat production challenges. ICARDA is part of an international research consortium to increase wheat yield and tolerance ...


Genome-Wide Association Studies In Maize And Sorghum, Preston Hurst Apr 2019

Genome-Wide Association Studies In Maize And Sorghum, Preston Hurst

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Genome-wide association studies are used to identify genetic variants associated with a particular phenotype. GWAS has been used in a variety of taxa, from humans, to fish to plants . The present analysis is focused on two species important to the human species: maize and sorghum. A GWAS in maize was carried out on the modification of the Ga1-s allele. The Ga1 locus has long been studied as being involved in a unilateral crossing barrier . However, it has long been suspected that the locus is modified by background genetic factors . GWAS was used to observe candidates for this modification. A series ...


Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn Apr 2019

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

Dissertations and Theses in Biological Sciences

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By ...


A Human Papillomavirus-Independent Cervical Cancer Animal Model Reveals Unconventional Mechanisms Of Cervical Carcinogenesis, Chunbo He, Xiangmin Lv, Cong Huang, Peter C. Angeletti, Guohua Hua, Jixin Dong, Jin Zhou, Zhengfeng Wang, Bowen Ma, Xingcheng Chen, Paul F. Lambert, Bo R. Rueda, John S. Davis, Cheng Wang Mar 2019

A Human Papillomavirus-Independent Cervical Cancer Animal Model Reveals Unconventional Mechanisms Of Cervical Carcinogenesis, Chunbo He, Xiangmin Lv, Cong Huang, Peter C. Angeletti, Guohua Hua, Jixin Dong, Jin Zhou, Zhengfeng Wang, Bowen Ma, Xingcheng Chen, Paul F. Lambert, Bo R. Rueda, John S. Davis, Cheng Wang

Virology Papers

HPV infections are common in healthy women and only rarely cause cervical cancer, suggesting that individual genetic susceptibility may play a critical role in the establishment of persistent HPV infection and the development of cervical cancer. Here, we provide convincing in vitro and in vivo evidence showing that differential expression and activation of YAP1 oncogene determine individual susceptibility to HPV infection and cervical carcinogenesis. We found that hyperactivation of YAP1 in mouse cervical epithelium was sufficient to induce invasive cervical cancer. Cervical epithelial cell-specific HPV16 E6/E7 and YAP1 double-knockin mouse model demonstrated that high-risk HPV synergized with hyperactivated YAP1 ...


Investigating The Role Of Free Radicals In Huntington's Disease Using Drosophila Melanogaster, Jennifer Libov Mar 2019

Investigating The Role Of Free Radicals In Huntington's Disease Using Drosophila Melanogaster, Jennifer Libov

Honors Theses, University of Nebraska-Lincoln

During normal cell metabolism, reactive oxygen species (ROS) are produced as a byproduct of oxidative phosphorylation. ROS are utilized in the cell as a signaling molecule and can be maintained at healthy levels by cellular antioxidants. However, when the cell experiences oxidative stress due to environmental or genetic conditions, levels of ROS can exceed healthy levels and inhibit necessary life functions by damaging biomolecules and cellular structures. This loss of function can lead to physiological decline and neurodegeneration, such as in diseases like Alzheimer’s, amyotrophic lateral sclerosis (ALS), and, potentially, Huntington’s disease. The following experiments use the model ...


Global Responses Of Resistant And Susceptible Sorghum (Sorghum Bicolor) To Sugarcane Aphid (Melanaphis Sacchari), Hannah M. Tetreault, Sajjan Grover, Erin Scully, Tammy Gries, Nathan A. Palmer, Gautam Sarath, Joe Louis, Scott E. Sattler Feb 2019

Global Responses Of Resistant And Susceptible Sorghum (Sorghum Bicolor) To Sugarcane Aphid (Melanaphis Sacchari), Hannah M. Tetreault, Sajjan Grover, Erin Scully, Tammy Gries, Nathan A. Palmer, Gautam Sarath, Joe Louis, Scott E. Sattler

Faculty Publications: Department of Entomology

The sugarcane aphid (Melanaphis sacchari) has emerged as a significant pest for sorghum. The use of sugarcane aphid-resistant sorghum germplasm with integrated pest management strategies appears to be an excellent solution to this problem. In this study, a resistant line (RTx2783) and a susceptible line (A/BCK60) were used to characterize the differences in plant responses to the sugarcane aphid through a series of experiments, which examined global sorghum gene expression, aphid feeding behavior and inheritance of aphid resistance. The global transcriptomic responses to sugarcane aphids in resistant and susceptible plants were identified using RNA-seq and compared to the expression ...


Metabolomics Profile And Targeted Lipidomics In Multiple Tissues Associated With Feed Efficiency In Beef Steers, Virginia M. Artegoitia, Andrew P. Foote, Ronald M. Lewis, Harvey C. Freetly Jan 2019

Metabolomics Profile And Targeted Lipidomics In Multiple Tissues Associated With Feed Efficiency In Beef Steers, Virginia M. Artegoitia, Andrew P. Foote, Ronald M. Lewis, Harvey C. Freetly

Faculty Papers and Publications in Animal Science

A study of multiple tissues was conducted to identify potential metabolic differences in cattle differing in feed efficiency. Individual feed intake and body weight was measured on 144 steers during 105 days on a high-concentrate ration. Steers were selected according to differences in average daily gain (ADG) with those with the greatest ADG (n = 8; 1.96 ± 0.02 kg/day) and least ADG (n = 8; 1.57 ± 0.02 kg/day), whose dry matter intake was within 0.32 SD of the mean intake (10.10 ± 0.05 kg/day). Duodenum, liver, adipose, and longissimus-dorsi were collected at slaughter ...


Persistent Viral Reservoirs In Lymphoid Tissues In Siv-Infected Rhesus Macaques Of Chinese-Origin On Suppressive Antiretroviral Therapy, Summer Siddiqui, Stefanie Perez, Yong Gao, Lara Doyle-Meyers, Brian T. Foley, Qingsheng Li, Binhua Ling Jan 2019

Persistent Viral Reservoirs In Lymphoid Tissues In Siv-Infected Rhesus Macaques Of Chinese-Origin On Suppressive Antiretroviral Therapy, Summer Siddiqui, Stefanie Perez, Yong Gao, Lara Doyle-Meyers, Brian T. Foley, Qingsheng Li, Binhua Ling

Virology Papers

Understanding HIV latent reservoirs in tissues is essential for the development of new strategies targeting these sites for eradication. Here, we assessed the size of latent reservoirs and the source of residual viruses in multiple lymphoid tissues of SIV-infected and fully suppressed rhesus macaques of Chinese-origin (cRMs). Eight cRMs were infected with SIVmac251 and treated with tenofovir and emtricitabine daily for 24 weeks initiated 4 weeks post-infection. Four of the eight animals reached sustained full viral suppression with undetectable viremia. The levels of cell-associated SIV DNA varied in peripheral blood mononuclear cells (PBMCs) and multiple lymphoid tissues, but with higher ...


Relationship Between The Cervical Microbiome, Hiv Status, And Precancerous Lesions, Cameron Klein, Daniela Gonzalez, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, Nirosh Aluthge, Samodha Fernando, John T. West, Charles Wood, Peter C. Angeletti Jan 2019

Relationship Between The Cervical Microbiome, Hiv Status, And Precancerous Lesions, Cameron Klein, Daniela Gonzalez, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, Nirosh Aluthge, Samodha Fernando, John T. West, Charles Wood, Peter C. Angeletti

Virology Papers

Nearly all cervical cancers are causally associated with human papillomavirus (HPV). The burden of HPV-associated dysplasias in sub-Saharan Africa is influenced by HIV. To investigate the role of the bacterial microbiome in cervical dysplasia, cytobrush samples were collected directly from cervical lesions of 144 Tanzanian women. The V4 hypervariable region of the 16S rRNA gene was amplified and deep sequenced. Alpha diversity metrics (Chao1, PD whole tree, and operational taxonomic unit [OTU] estimates) displayed significantly higher bacterial richness in HIV-positive patients (P = 0.01) than in HIV-negative patients. In HIV-positive patients, there was higher bacterial richness in patients with high-grade ...


Near-Atomic Structure Of A Giant Virus, Qianglin Fang, Dongjie Zhu, Irina Agarkova, Jagat Adhikari, Thomas Klose, Yue Liu, Zhenguo Chen, Yingyuan Sun, Michael L. Gross, James L. Van Etten, Xinzheng Zhang, Michael G. Rossmann Jan 2019

Near-Atomic Structure Of A Giant Virus, Qianglin Fang, Dongjie Zhu, Irina Agarkova, Jagat Adhikari, Thomas Klose, Yue Liu, Zhenguo Chen, Yingyuan Sun, Michael L. Gross, James L. Van Etten, Xinzheng Zhang, Michael G. Rossmann

Virology Papers

Although the nucleocytoplasmic large DNA viruses (NCLDVs) are one of the largest group of viruses that infect many eukaryotic hosts, the near-atomic resolution structures of these viruses have remained unknown. Here we describe a 3.5 Å resolution icosahedrally averaged capsid structure of Paramecium bursaria chlorella virus 1 (PBCV-1). This structure consists of 5040 copies of the major capsid protein, 60 copies of the penton protein and 1800 minor capsid proteins of which there are 13 different types. The minor capsid proteins form a hexagonal network below the outer capsid shell, stabilizing the capsid by binding neighboring capsomers together. The ...


A Poxvirus Pseudokinase Represses Viral Dna Replication Via A Pathway Antagonized By Its Paralog Kinase, Annabel T. Olson, Zhigang Wang, Amber B. Rico, Matthew S. Wiebe Jan 2019

A Poxvirus Pseudokinase Represses Viral Dna Replication Via A Pathway Antagonized By Its Paralog Kinase, Annabel T. Olson, Zhigang Wang, Amber B. Rico, Matthew S. Wiebe

Virology Papers

Poxviruses employ sophisticated, but incompletely understood, signaling pathways that engage cellular defense mechanisms and simultaneously ensure viral factors are modulated properly. For example, the vaccinia B1 protein kinase plays a vital role in inactivating the cellular antiviral factor BAF, and likely orchestrates other pathways as well. In this study, we utilized experimental evolution of a B1 deletion virus to perform an unbiased search for suppressor mutations and identify novel pathways involving B1. After several passages of the ΔB1 virus we observed a robust increase in viral titer of the adapted virus. Interestingly, our characterization of the adapted viruses reveals that ...


Longitudinal Study Of Humoral Immunity To Bovine Coronavirus, Virus Shedding, And Treatment For Bovine Respiratory Disease In Pre-Weaned Beef Calves, Aspen M. Workman, Larry A. Kuehn, Tara G. Mcdaneld, Michael L. Clawson, John Dustin Loy Jan 2019

Longitudinal Study Of Humoral Immunity To Bovine Coronavirus, Virus Shedding, And Treatment For Bovine Respiratory Disease In Pre-Weaned Beef Calves, Aspen M. Workman, Larry A. Kuehn, Tara G. Mcdaneld, Michael L. Clawson, John Dustin Loy

Faculty Papers and Publications in Animal Science

Background: Bovine coronavirus (BCV) is associated with respiratory infections in cattle of all ages; however, a temporal study to evaluate the effect of BCV immunity on virus shedding and bovine respiratory disease (BRD) incidence in pre-weaned beef calves has not been reported. Thus, we report here a prospective study in three herds of crossbred beef calves (n = 817) with endemic BCV. Serial blood samples for measurement of serum anti-BCV antibody titers and nasal swabs for detection of BCV and other common viral and bacterial BRD pathogens were collected from all calves or subsets of calves at predetermined times from birth ...