Do Nitrogen and Phosphorus Influence Channel Catfish Growth in a Great Plains River?

Evaluating abiotic environmental factors that influence growth of sportfish is key to understanding population dynamics and making appropriate management decisions. This is especially true in river systems where primary and secondary productivity can vary across temporal and spatial scales. In this study, we assessed fish responses to ambient nutrient levels (total nitrogen and total phosphorus) using growth rates determined from age-1 Channel Catfish, Ictalurus punctatus, in Platte River, Nebraska. Water quality and growth data were collected from sites across the central and lower Platte River from 2007 to 2013. We analyzed Platte River water quality data to find yearly average levels of total nitrogen and phosphorus in the system. Results show a significant difference in growth rates and nutrients levels across Platte River segments, however nutrient levels did not help explain the differences in growth. For example, the mean growth rate across years was not significant between central and lower river segments (p-value = 0.202), but the mean total nitrogen and total phosphorus levels were significantly greater in the lower river segment across all years (p = 0.004 for nitrogen and p = 2.028-6 for phosphorus). While this study lacks evidence for a clear correlation between nutrient levels and Channel Catfish growth future investigations could help clarify the short-term and long-term impacts of eutrophication of rivers such as the Platte River that run through agricultural and urban landscpaes

Rare Dark American Kestrel – Melanistic or Sooty?

On April 13 in Seward County, we noticed a dark bird flying relatively low over fields east of Seward near 224th and Bluff Rd. Initially, because of its size, dark coloration and pointed wingtips, we were unsure of its identification and followed the bird to get better looks and identify it. We were able to observe and photograph the bird perched (Figure 1). We also observed the bird hovering and diving to the ground multiple times in search of prey. After better looks, based on size, wing shape, hooked beak, claws, and behavior (repeated hovering over field), we concluded the bird was an American Kestrel (Falco sparverius). Joel and Camden returned later in the day and were able to relocate the bird. Camden got photos of the kestrel in flight showing additional details (Figure 2). We believe the observed bird was a female based on barring in the tail. As can be seen in the photos, the head and body patterns normally seen in American Kestrels are absent. Barring can be seen in both the underwings and the tail (Figures 1 and 2) while light-colored feathers are visible in the vent and belly. Both the cere and feet are yellow/orange normally seen in kestrels. Initially, we thought the bird was a melanistic American Kestrel. There is widespread misunderstanding about the causes of dark coloration in birds (Davis 2007; van Grouw 2017), so we shared the photos with people who had studied dark coloration in birds. Some believed the bird was melanistic and others believed it was soot-covered. We will discuss both below

Effects of pro-inflamatory cytokines on polarized rat parotid Par-C10 monolayers [abstract]

Abstract only availableSjögren's syndrome (SS), an autoimmune disorder, is distinguished by inflammation and salivary gland cell death, leading to xerostomia (dry mouth). The G protein-coupled P2Y2 receptor (P2Y2R) is up-regulated in response to damage or stress in salivary epithelium. Pro-inflammatory cytokines associated with SS can be produced by infiltrating lymphocytes or salivary epithelium. Correlations have been found between lymphocytic infiltration and increased production of pro-inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-Éø (TNFα) and interferon-γ (IFNγ) and decreased function of exocrine glands in SS. Recent data has shown that P2Y2R activation enhances the activity of metalloproteases that release TNFα. OBJECTIVES: To study the effects of cytokines on polarized salivary epithelium. METHODS: Polarized rat parotid (Par-C10) monolayers were used to perform these studies. Cytokines released by UTP-induced P2Y2R activation were identified by ELISA. To evaluate the role of cytokines associated with SS on epithelial integrity, epithelial resistance was determined and correlated with the expression and distribution of tight junction (TJ) proteins by immunofluorescence and Western analysis, respectively. RESULTS: Activation of P2Y2Rs in Par-C10 monolayers induced the release of TNFα. The cytokines TNFα and IFNγ, but not IL-6 or IL1β, decreased the resistance of Par-C10 cells. However, the expression/distribution of the TJ protein ZO-1 was unaffected. CONCLUSIONS: The data support a hypothesis that P2Y2R expression and activation in salivary gland cells contribute to epithelial dysfunction in SS by generating pro-inflammatory cytokines that regulate ion transport and epithelial integrity in salivary glands. Future studies will determine the role of cytokines on the expression and distribution of other TJ molecules including occludin, claudins and junctional adhesion molecules. These studies may lead to better therapeutic strategies for minimizing autoimmune-associated dysfunction of salivary gland that contributes to xerostomia in SS patient.Life Sciences Undergraduate Research Opportunity Progra

Up-regulation of the P2Y2 receptor by cytokines in neuronal cells

Abstract only availableAlzheimer's Disease (AD) is characterized by inflammation and neurodegeneration in the brain due to the presence of extracellular amyloid beta (A β) plaques and neurofibrillary tangles. Microglial and astrocyte cells associated with these plaques and tangles have been shown to release cytokines in AD patients, which have a proinflammatory effect on the brain. The P2Y2 receptor (P2Y2R) is a receptor protein that is up-regulated in response to damage or stress in a variety of tissues, including blood vessels and salivary gland epithelium. Recently our laboratory has shown that activation of the P2Y2R enhances α -secretase-dependent amyloid precursor protein (APP) processing. APP is proteolytically processed by β - and γ -secretases to release neurodegenerative A β. Alternatively, APP can be cleaved within the A β domain by α -secretase releasing the non-amyloidogenic product, sAPP α, which has been shown to have neuroprotective properties. Primary neurons have low P2Y2R expression, however, it has been demonstrated that cytokines up-regulate P2Y2R in smooth muscle cells. Therefore, this study will explore if cytokines up-regulate P2Y2R expression in primary rat neurons and in SH-SY5Y human neuroblastoma cells. Primary rat neurons and SH-SY5Y human neuroblastoma cells were plated on glass cover slips 24 or 48 hours with individual treatment, or a combination of, human interleukin-1 β (IL1- β), tumor necrosis factor α (TNF α), and interferon γ (IF γ). P2Y2R activity was measured by increases in intracellular calcium concentration ([Ca2+]i ) in response to the P2Y2R agonist UTP. Results support the hypothesis that P2Y2R is up-regulated by cytokines in neuronal cells. Furthermore, real-time PCR results indicate a two-fold increase in P2Y2R mRNA after cytokine treatment. Therefore, activation of the up-regulated P2Y2R in stressed neurons generates a neuroprotective (sAPP α) rather than neurodegenerative (A β) peptide. These results could have a substantial impact on the understanding and treatment of neurological disorders such as AD.Life Sciences Undergraduate Research Opportunity Progra

Conquering APA Style: Advice From APA Style Experts

Learning and teaching APA style is often a challenge because of the detailed rules for the writing style. Resources that provide accurate information about APA style that are easy for learners to consume can be useful tools for students and instructors. The goal of this article is to provide information to help writers become more competent and comfortable with APA style. The first section of this article contains lists of common APA style mistakes that are made when papers are submitted for publication. Editors look for very specific APA formatting and style, and this section will cover these issues. Moreover, the second section includes a list of APA style rules frequently encountered by an APA style tutor. The third section has information to help students navigate writing assignments in a research methods class. The fourth section addresses additional APA style rules that many writers do not know about. Finally, this information can serve as a guide for writers to use when writing APA style papers

Phosphorylation of EGFR, ERK 1/2 and downstream transcription factors after P2Y2 receptor activation in a human submandibular gland cell line

Abstract only availableP2 nucleotide receptors mediate a variety of biological responses and are activated by the extracellular nucleotides adenosine triphosphate (ATP), adenosine diphosphate (ADP), uridine triphosphate (UTP), uridine diphosphate (UDP). The P2Y2 nucleotide receptor is a seven transmembrane spanning domain receptor activated by the nucleotides ATP and UTP, and is up-regulated in a variety of tissues in response to injury or stress. For example, the P2Y2 receptors are not normally expressed in salivary glands, but upon disruption of tissue homeostasis, the P2Y2 receptors are up-regulated. Sjogren's disease is an autoimmune disorder that affects salivary and lacrimal glands resulting in a decreased ability to produce saliva and tears. Previous work by our lab has shown that the P2Y2 receptor is up-regulated in submandibular glands of a Sjogren's syndrome mouse model, suggesting that it may be up-regulated in human Sjogren's syndrome. The goal of this project is to analyze the function of P2Y2 receptors in salivary gland tissues. HSG cells, which endogenously express P2Y2 receptors and are derived from a human submandibular gland tumor, were utilized as a cell model to analyze downstream signaling pathways in response to UTP. Our results show that UTP, the P2Y2 receptor selective agonist, causes phosphorylation of the epidermal growth factor receptor (EGFR), extracellular regulated kinases (ERK 1/2) and the downstream transcription factors p90RSK, and ELK, suggesting that P2Y2 receptors may play a role in gene transcription in salivary gland tissues.NSF-REU Biology & Biochemistr

P2Y2 nucleotide receptors mediate inflammatory responses in mouse salivary gland cells

Abstract only availableSjögren's syndrome (SS) is a chronic inflammatory autoimmune disease characterized by destruction of salivary and lacrimal glands leading to xerostomia (dry mouth) and xerophthalmia (dry eyes). Although the mechanisms involved have not been adequately elucidated, the diminished function of exocrine glands in SS is often associated with lymphocytic infiltration of the tissue. Aberrant expression of specific adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) is also observed in salivary gland with SS, which enable salivary epithelium to interact directly with infiltrating lymphocytes. P2Y2 nucleotide receptor (P2Y2R) is G protein-couple receptor that is activated by extracellular ATP and UTP. P2Y2R expression and activity is up-regulated in response to damage or stress in a variety of tissues, including submandibular glands (SMGs), where it mediates a complex set of cellular responses to injury of disease. Additionally, P2Y2R activation up-regulates VCAM-1 expression in dispersed rat SMG cell culture and human submandibular gland (HSG) cells. Our objective is to investigate weather P2Y2R up-regulation correlates with increased expression of adhesion molecules in SMGs from a mouse model for SS (C57BL/6.NOD-Aec1Aec2) as compared with normal mouse strain (C57BL/6). P2Y2R expression was measured by RT-PCR and adhesion molecules expression was determined by Western blot analysis. Salivary flow was preformed by cannulation of individual glands. We could see that P2Y2R expression and ICAM-1 expression were both up-regulated in the SMGs from a mouse model for SS as compared with normal mouse strain. And salivary flow was decreased in salivary glands from a mouse model for SS. These results suggest that P2Y2R mediate inflammatory responses related to secretory dysfunction in the mouse model for SS. Our ultimate goal would be to translate all this information to the human salivary gland in order to understand SS and to develop new therapies for salivary dysfunction in SS.Gyeongsang National Universit

The Crystal Structure of Rb4SbIIISbvBr12

The crystal structure of rubidium hexabromoantimonate has been determined from three dimensional X-ray data. Eight molecules per unit cell crystallize in the tetragonal space group I41/amd (D4h19) with a = 10.70 and c = 21.69 Å. The structure was refined by full matrix least squares with all atoms anisotropic to a discrepancy index, R = 0.102 for 401 independent reflections collected by peak height counter methods. The structure is almost isomorphic with that of (NH4)4SbIIISbvBr12. Both the SbIIIBr6-3 and the SbvBr6-1 ions are distorted from Oh symmetry and possess D2d symmetry. These distortions indicate considerable interaction between the SbvBr6-1, SbIIIBr6-3, and the Rb+ ions

Fundamentals of Polymer Crystallization in Laser Powder Bed Fusion for New Material Screening

Although laser powder bed fusion (PBF/LB) was one of the first industrially viable additive manufacturing (AM) methods for end-use part production, polyamides remain grossly dominant at both the commercial- and research scale. The research community continues to develop and refine “rapid screening” methods for evaluating the suitability of new polymers for PBF/LB. The so-called “SLS Process Window,” which is the difference between melting and crystallization temperature measured at 10 K min-1 as originally outlined in the patent literature, is perhaps the most often reported screening method. Although perhaps appropriate as part of a larger study, the simplistic guidelines put forth by the “SLS Process Window” are not sufficiently scientifically rigorous to understand how crystallization kinetics affects successful 3D printing. The common understanding of the SLS Process Window omits details from published theories of polymer crystallization. as evidenced by published assumptions and methods in PBF/LB process modeling papers. The authors explain polymer crystallization in the PBF/LB context and propose replacing the “process window” with crystallization halftime and physical gelation for new material screening. These measurements better represent behavior critical for ensuring a lengthy coexistence of solid powder and molten polymer affecting warp-free parts.Mechanical Engineerin