Systems Biology Commons^™

Effect Of Nitrogen Addition On The Comparative Productivity Of Corn And Velvetleaf (Abutilon Theophrasti), Darren C. Barker, Stevan Z. Knezevic, Alex R. Martin, Daniel T. Walters, John L. Lindquist

John L. Lindquist

Weeds that respond more to nitrogen fertilizer than crops may be more competitive under high nitrogen (N) conditions. Therefore, understanding the effects of nitrogen on crop and weed growth and competition is critical. Field experiments were conducted at two locations in 1999 and 2000 to determine the influence of varying levels of N addition on corn and velvetleaf height, leaf area, biomass accumulation, and yield. Nitrogen addition increased corn and velvetleaf height by a maximum of 15 and 68%, respectively. N addition increased corn and velvetleaf maximum leaf area index (LAI) by up to 51 and 90%. Corn and velvetleaf …

Understanding Corn Yield Potential In Different Environments, Achim R. Dobermann, Timothy J. Arkebauer, Kenneth G. Cassman, Rhae A. Drijber, John L. Lindquist, James E. Specht, Daniel T. Walters, Haishun Yang, Daniel N. Miller, Darren L. Binder, Gregory J. Teichmeier, Richard B. Ferguson, Charles S. Wortmann

John L. Lindquist

The UNL research program on Ecological intensification of irrigated maize-based cropping systems aims to (i) improve understanding of the yield potential of corn and soybean and how it is affected by management, (ii) develop a scientific basis for evaluating yield potential at different locations, (iii) develop practical technologies for managing intensive cropping systems at 70-80% of the yield potential, and (iv) conduct integrated assessment of productivity, profitability, input use efficiency, soil carbon sequestration, energy and carbon budgets, and trace gas emissions. Results of this work have been reported earlier (Arkebauer et al., 2001; Dobermann et al., 2002). In this paper …

Influence Of Soybean Row Width And Velvetleaf Emergence Time On Velvetleaf (Abutilon Theophrasti), Shawn M. Hock, Stevan Z. Knezevic, Alex R. Martin, John L. Lindquist

John L. Lindquist

Row spacing and the relative time of velvetleaf emergence affects the time of soybean canopy closure relative to velvetleaf, influencing the growth and development of velvetleaf. Field studies were conducted in northeastern Nebraska in 2002 and 2003 to describe velvetleaf growth as influenced by soybean presence or absence (velvetleaf grown with soybean or in monoculture), soybean row spacing (19 and 76 cm), and relative time of velvetleaf emergence. Velvetleaf seed production, leaf area (LA), and total dry matter (TDM) were greater in 76-cm- than in 19-cm-wide soybean rows. LA, TDM, and seed production of velvetleaf were reduced with later emergence …

Corn–Velvetleaf (Abutilon Theophrasti ) Interference Is Affected By Sublethal Doses Of Postemergence Herbicides, Brescia R. M. Terra, Alexander R. Martin, John L. Lindquist

John L. Lindquist

Injury to weeds from sublethal doses of POST herbicides may reduce the effect of weed interference on crop yield. Information on how herbicide dose influences weed mortality, growth, and seed production is needed to assess the potential benefit of applying reduced herbicide doses. Field experiments were conducted at Mead, NE, in 2001 and 2002 to quantify velvetleaf mortality, growth, and corn–velvetleaf interference in response to varying doses of three POST herbicides. Untreated velvetleaf at six densities (0, 1, 3, 6, 12, and 20 plants m-1 corn row) was grown in mixture with corn to establish a baseline corn–velvetleaf interference relationship. …

Glyphosate Efficacy On Velvetleaf Varies With Application Time Of Day, Aaron L. Waltz, Alex R. Martin, Fred W. Roeth, John L. Lindquist

John L. Lindquist

Field and growth chamber experiments determined the efficacy of temporal glyphosate applications on velvetleaf. Glyphosate was applied post-emergence to velvetleaf periodically before and during light and after dark. In 1999, glyphosate at 840 g ae/ha applied before sunrise and after midday provided 54 and 100% velvetleaf control, respectively. In 2000, glyphosate at 840 g/ha applied before sunrise, midday, and after sunset provided 69, 100, and 37% velvetleaf control, respectively. In the growth chamber, glyphosate at 840 g/ha applied before or after light reduced velvetleaf biomass 15 to 20% or 32 to 47%, respectively, and reduced velvetleaf height 24% or 45 …

Factors Affecting The Realized Niche Of Common Sunflower (Helianthus Annuus) In Ridge-Tillage Corn, Michael G. Burton, David A. Mortensen, David B. Marx, John L. Lindquist

John L. Lindquist

Because soil characteristics and weed densities vary within agricultural landscapes, determining which subfield areas are most favorable to weed species may aid in their management. Field and greenhouse studies were conducted to determine whether subfield environments characterized by higher soil organic carbon (SOC), or ridge vs. furrow microsites, affect common sunflower seed germination after winter burial, seedling emergence, or the control afforded by a preemergence herbicide in a ridge-tillage corn production system. Among seeds buried in situ during winter months and germinated in the laboratory, no differences in common sunflower seed germination or mortality were detected between high-SOC (1.8% mean) …

Predicting Biomass Partitioning To Root Versus Shoot In Corn And Velvetleaf (Abutilon Theophrasti), Kimberly D. Bonifas, John L. Lindquist

John L. Lindquist

Knowledge of how plants will partition their new biomass will aid in understanding competition between crops and weeds. This study determined if the amount of biomass partitioned to the root versus the shoot can be predicted from tissue carbon [C] and nitrogen [N] concentrations and the daily gain in C (G_C) and N (G_N) for each unit shoot and root biomass, respectively. Pots measuring 28 cm diameter and 60 cm deep were embedded in the ground, and each contained one plant of either corn or velvetleaf. Each plant received one of three nitrogen treatments: 0, 1, …

An Improved Measure Of Angular Dispersion In Plant Neighborhoods, Klaus J. Puettmann, Dan Rhode, Bruce D. Maxwell, John L. Lindquist

John L. Lindquist

Spatial distribution is an important factor determining the intensity and outcome of plant competition. The commonly used measure of angular distributions of plants around a target plant (1 - r) is shown to be limited to unimodal distributions. We present a new index which is based on the variance of the differences between the azimuth of neighboring plants. The new index is an improvement as it characterizes the angular dispersion in both unimodal and multimodal distributions.

Nitrogen Supply Affects Root:Shoot Ratio In Corn And Velvetleaf (Abutilon Theophrasti), Kimberly D. Bonifas, Daniel T. Walters, Kenneth G. Cassman, John L. Lindquist

John L. Lindquist

Competitive outcome between crops and weeds is affected by partitioning of new biomass to above- and below-ground plant organs in response to nutrient supply. This study determined the fraction of biomass partitioned to roots vs. shoots in corn and velvetleaf in response to nitrogen (N) supply. Pots measuring 28 cm in diam and 60 cm deep were embedded in the ground and each contained one plant of either corn or velvetleaf. Each plant received one of three N treatments: 0, 1, or 3 g N applied as ammonium nitrate in 2001, and 0, 2, or 6 g N in 2002. …

Simulation Study Of The Competitive Ability Of Erect, Semi-Erect, And Prostrate Cowpea (Vigna Unguiculata) Genotypes, G. Wang, M. E. Mcgiffen Jr., John L. Lindquist, J. D. Ehlers, I. Sartorato

John L. Lindquist

Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics, and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterized, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower …

Changes In Nitrogen Use Efficiency And Soil Quality After Five Years Of Managing For High Yield Corn And Soybean, Timothy J. Arkebauer, Achim R. Dobermann, Kenneth G. Cassman, Rhae A. Drijber, J. Lindquist, James E. Specht, Daniel T. Walters, Haishun Yang

John L. Lindquist

Average corn grain yields in the USA have increased linearly at a rate of 1.7 bu/acre over the past 35 years with a national yield average of 140 bu/acre. Corn yield contest winners and simulation models, however, indicate there is ~100 bu/a in exploitable corn yield gap. Four years (1999-2002) of plant development, grain yield and nutrient uptake were compared in intensive irrigated maize systems representing (a) recommended best management practices for a yield goal of 200 bu/acre (M1) and (b) intensive management aiming at a yield goal of 300 bu/acre (M2). For each management level, three levels of plant …

Comparative Nitrogen Uptake And Distribution In Corn And Velvetleaf (Abutilon Theophrasti), John L. Lindquist, Darren C. Barker, Stevan Z. Knezevic, Alexander R. Martin, Daniel T. Walters

John L. Lindquist

Weeds compete with crops for light, soil water, and nutrients. Nitrogen (N) is the primary limiting soil nutrient. Forecasting the effects of N on growth, development, and interplant competition requires accurate prediction of N uptake and distribution within plants. Field studies were conducted in 1999 and 2000 to determine the effects of variable N addition on monoculture corn and velvetleaf N uptake, the relationship between plant N concentration ([N]) and total biomass, the fraction of N partitioned to leaves, and predicted N uptake and leaf N content. Cumulative N uptake of both species was generally greater in 2000 than in …

Deletion Of Galectin-3 Exacerbates Microglial Activation And Accelerates Disease Progression And Demise In A Sod1 G93a Mouse Model Of Amyotrophic Lateral Sclerosis, Bruce J. Lerman, Eric P. Hoffman, Margaret L. Sutherland, Khaled Bouri, Daniel K. Hsu, Jeffrey D. Rothstein, Susan M. Knoblach

Genomics and Precision Medicine Faculty Publications

Galectins are pleiotropic carbohydrate-binding lectins involved in inflammation, growth/differentiation, and tissue remodeling. The functional role of galectins in amyotrophic lateral sclerosis (ALS) is unknown. Expression studies revealed increases in galectin-1 mRNA and protein in spinal cords from SOD1 ^G93A mice, and in galectin-3 and -9 mRNAs and proteins in spinal cords of both SOD1^G93A mice and sporadic ALS patients. As the increase in galectin-3 appeared in early presymptomatic stages and increased progressively through to end stage of disease in the mouse, it was selected for additional study, where it was found to be mainly expressed by microglia. Galectin-3 antagonists …

The Breathing Of The Bays, Jamie Vaudrey, Margaret (Peg) A. Van_Patten (Editor)

Wrack Lines

Bays in Long Island Sound and beyond have natural rhythms like breathing. Stress can impact the health of these natural ecosystems. While Long Island Sound has been examined for the extent of hypoxia in the summer, small embayments have not been examined carefully. In this article, two researchers investigate the oxygen, or lack of, in small bays of Long Island Sound.

Systems Biology Approaches To Probe Gene Regulation In Bacteria, Diogo F. Troggian Veiga

Dissertations & Theses (Open Access)

Mechanisms that allow pathogens to colonize the host are not the product of isolated genes, but instead emerge from the concerted operation of regulatory networks. Therefore, identifying components and the systemic behavior of networks is necessary to a better understanding of gene regulation and pathogenesis. To this end, I have developed systems biology approaches to study transcriptional and post-transcriptional gene regulation in bacteria, with an emphasis in the human pathogen Mycobacterium tuberculosis (Mtb).

First, I developed a network response method to identify parts of the Mtb global transcriptional regulatory network utilized by the pathogen to counteract phagosomal stresses …

The Crayfish (Decapoda: Cambaridae) Subgenus Hiaticambarus: Undescribed Diversity And Life History Characteristics Of Selected Members, Danny Jones

All Dissertations

A taxonomic study of the crayfish species Cambarus (Hiaticambarus) longirostris was conducted. Multivariate and univariate statistical analyses of morphometric data and examination of morphological characters revealed the existence of four undescribed species from populations previously considered to belong to C. longirostris; these were located on the southern extents of the range of C. longirostris. Three of these new species were morphologically similar to the group of species containing C. coosawattae, C. chasmodactylus, C. elkensis, C. longirostris, C. longulus, and C. manningi, while one was morphologically similar to the C. fasciatus, C. …

Platelets Induce Apoptosis During Sepsis In A Contact-Dependent Manner That Is Inhibited By Gpiib/Iiia Blockade, Matthew Sharron, Claire E. Hoptay, Andrew A. Wiles, Lindsay M. Garvin, Mayya Geha, Angela S. Benton, Kanneboyina Nagaraju, Robert J. Freishtat

Genomics and Precision Medicine Faculty Publications

Purpose

End-organ apoptosis is well-described in progressive sepsis and Multiple Organ Dysfunction Syndrome (MODS), especially where platelets accumulate (e.g. spleen and lung). We previously reported an acute sepsis-induced cytotoxic platelet phenotype expressing serine protease granzyme B. We now aim to define the site(s) of and mechanism(s) by which platelet granzyme B induces end-organ apoptosis in sepsis.

Methods

End-organ apoptosis in murine sepsis (i.e. polymicrobial peritonitis) was analyzed by immunohistochemistry. Platelet cytotoxicity was measured by flow cytometry following 90 minute ex vivo co-incubation with healthy murine splenocytes. Sepsis progression was measured via validated preclinical murine sepsis score.

Measurements and Main Results …

List Of Thylakoid Zinc-Finger Proteins In Arabidopsis, Yan Lu

Yan Lu

No abstract provided.

Conditional Over-Expression Of Pitx1 Causes Skeletal Muscle Dystrophy In Mice, Sachchida Nand Pandey, Jennifer Cabotage, Rongye Shi, Manjusha Dixit, Margaret L. Sutherland, Jian Liu, Stephanie Muger, Scott Q. Harper, Kanneboyina Nagaraju, Yi-Wen Chen

Genomics and Precision Medicine Faculty Publications

Paired-like homeodomain transcription factor 1 (PITX1) was specifically up-regulated in patients with facioscapulohumeral muscular dystrophy (FSHD) by comparing the genome-wide mRNA expression profiles of 12 neuromuscular disorders. In addition, it is the only known direct transcriptional target of the double homeobox protein 4 (DUX4) of which aberrant expression has been shown to be the cause of FSHD. To test the hypothesis that up-regulation of PITX1 contributes to the skeletal muscle atrophy seen in patients with FSHD, we generated a tet-repressible muscle-specific Pitx1 transgenic mouse model in which expression of PITX1 in skeletal muscle can be controlled by oral administration of …

Il-6 Signaling Blockade Increases Inflammation But Does Not Affect Muscle Function In The Mdx Mouse, Mathew A. Kostek, Kanneboyina Nagaraju, Emidio E. Pistilli, Arpana Sali, San-Huei Lai, Brad Gordon, Yi-Wen Chen

Genomics and Precision Medicine Faculty Publications

No abstract provided.