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Search Results: 1 - 10 of 224335 matches for " Wendell C. Johnson "
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Ovine Progressive Pneumonia Virus Is Transmitted More Effectively via Aerosol Nebulization than Oral Administration  [PDF]
Lynn M. Herrmann-Hoesing, Stephen N. White, Liam E. Broughton-Neiswanger, Wendell C. Johnson, Susan M. Noh, David A. Schneider, Hong Li, Naomi S. Taus, James Reynolds, Thomas Truscott, Rohana P. Dassanayake, Donald P. Knowles
Open Journal of Veterinary Medicine (OJVM) , 2012, DOI: 10.4236/ojvm.2012.23019
Abstract: A new method of experimental infection of ovine progressive pneumonia virus (OPPV), aerosol nebulization (Nb), was compared to intravenous (IV) and oral (PO) methods of experimental infection. Seven month old lambs were given 3.5 × 107 TCID50 of Dubois OPPV LMH19 isolate using IV, PO, or Nb methods and were monitored for infection using cELISA and OPPV quantitative (q) PCR for 35 weeks. Four out of four sheep in the IV group, six out of six sheep in the Nb group, but only two out of six sheep in the PO group became infected by OPPV; whereas the uninoculated controls (n = 2) and a sentinel control (n = 1) remained uninfected during the course of the study. The time to a cELISA or OPPV qPCR positive result in the Nb group was quicker and statistically different from the time to a cELISA or OPPV qPCR positive result in the PO group (cELISA P value = 0.0021 and OPPV qPCR P value = 0.0007). When the Nb and IV groups were compared, sheep became cELISA and OPPV qPCR positive at similar times (cELISA P value = 0.6 and OPPV qPCR P value = 0.1). In addition, sheep became OPPV qPCR positive prior to cELISA in both the IV and Nb groups (IV P value = 0.027 and Nb P value = 0.007). Aerosol nebulization is a more natural experimental method of transmitting OPPV and may be valuable for testing potential vaccines or specific host genetics.
Lymphocytes and Macrophages Are Infected by Theileria equi, but T Cells and B Cells Are Not Required to Establish Infection In Vivo
Joshua D. Ramsay, Massaro W. Ueti, Wendell C. Johnson, Glen A. Scoles, Donald P. Knowles, Robert H. Mealey
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0076996
Abstract: Theileria equi has a biphasic life cycle in horses, with a period of intraleukocyte development followed by patent erythrocytic parasitemia that causes acute and sometimes fatal hemolytic disease. Unlike Theileria spp. that infect cattle (Theileria parva and Theileria annulata), the intraleukocyte stage (schizont) of Theileria equi does not cause uncontrolled host cell proliferation or other significant pathology. Nevertheless, schizont-infected leukocytes are of interest because of their potential to alter host cell function and because immune responses directed against this stage could halt infection and prevent disease. Based on cellular morphology, Theileria equi has been reported to infect lymphocytes in vivo and in vitro, but the specific phenotype of schizont-infected cells has yet to be defined. To resolve this knowledge gap in Theileria equi pathogenesis, peripheral blood mononuclear cells were infected in vitro and the phenotype of infected cells determined using flow cytometry and immunofluorescence microscopy. These experiments demonstrated that the host cell range of Theileria equi was broader than initially reported and included B lymphocytes, T lymphocytes and monocyte/macrophages. To determine if B and T lymphocytes were required to establish infection in vivo, horses affected with severe combined immunodeficiency (SCID), which lack functional B and T lymphocytes, were inoculated with Theileria equi sporozoites. SCID horses developed patent erythrocytic parasitemia, indicating that B and T lymphocytes are not necessary to complete the Theileria equi life cycle in vivo. These findings suggest that the factors mediating Theileria equi leukocyte invasion and intracytoplasmic differentiation are common to several leukocyte subsets and are less restricted than for Theileria annulata and Theileria parva. These data will greatly facilitate future investigation into the relationships between Theileria equi leukocyte tropism and pathogenesis, breed susceptibility, and strain virulence.
Differential Expression of Three Members of the Multidomain Adhesion CCp Family in Babesia bigemina, Babesia bovis and Theileria equi
Reginaldo G. Bastos, Carlos E. Suarez, Jacob M. Laughery, Wendell C. Johnson, Massaro W. Ueti, Donald P. Knowles
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067765
Abstract: Members of the CCp protein family have been previously described to be expressed on gametocytes of apicomplexan Plasmodium parasites. Knocking out Plasmodium CCp genes blocks the development of the parasite in the mosquito vector, making the CCp proteins potential targets for the development of a transmission-blocking vaccine. Apicomplexans Babesia bovis and Babesia bigemina are the causative agents of bovine babesiosis, and apicomplexan Theileria equi causes equine piroplasmosis. Bovine babesiosis and equine piroplasmosis are the most economically important parasite diseases that affect worldwide cattle and equine industries, respectively. The recent sequencing of the B. bovis and T. equi genomes has provided the opportunity to identify novel genes involved in parasite biology. Here we characterize three members of the CCp family, named CCp1, CCp2 and CCp3, in B. bigemina, B. bovis and T. equi. Using B. bigemina as an in vitro model, expression of all three CCp genes and proteins was demonstrated in temperature-induced sexual stages. Transcripts for all three CCp genes were found in vivo in blood stages of T. equi, and transcripts for CCp3 were detected in vivo in blood stages of B. bovis. However, no protein expression was detected in T. equi blood stages or B. bovis blood stages or B. bovis tick stages. Collectively, the data demonstrated a differential pattern of expression of three orthologous genes of the multidomain adhesion CCp family by B. bigemina, B. bovis and T. equi. The novel CCp members represent potential targets for innovative approaches to control bovine babesiosis and equine piroplasmosis.
A Divergent Artiodactyl MYADM-like Repeat Is Associated with Erythrocyte Traits and Weight of Lamb Weaned in Domestic Sheep
Michael V. Gonzalez, Michelle R. Mousel, David R. Herndon, Yu Jiang, Brian P. Dalrymple, James O. Reynolds, Wendell C. Johnson, Lynn M. Herrmann-Hoesing, Stephen N. White
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0074700
Abstract: A genome-wide association study (GWAS) was performed to investigate seven red blood cell (RBC) phenotypes in over 500 domestic sheep (Ovis aries) from three breeds (Columbia, Polypay, and Rambouillet). A single nucleotide polymorphism (SNP) showed genome-wide significant association with increased mean corpuscular hemoglobin concentration (MCHC, P = 6.2×10?14) and genome-wide suggestive association with decreased mean corpuscular volume (MCV, P = 2.5×10?6). The ovine HapMap project found the same genomic region and the same peak SNP has been under extreme historical selective pressure, demonstrating the importance of this region for survival, reproduction, and/or artificially selected traits. We observed a large (>50 kb) variant haplotype sequence containing a full-length divergent artiodactyl MYADM-like repeat in strong linkage disequilibrium with the associated SNP. MYADM gene family members play roles in membrane organization and formation in myeloid cells. However, to our knowledge, no member of the MYADM gene family has been identified in development of morphologically variant RBCs. The specific RBC differences may be indicative of alterations in morphology. Additionally, erythrocytes with altered morphological structure often exhibit increased structural fragility, leading to increased RBC turnover and energy expenditure. The divergent artiodactyl MYADM-like repeat was also associated with increased ewe lifetime kilograms of lamb weaned (P = 2×10?4). This suggests selection for normal RBCs might increase lamb weights, although further validation is required before implementation in marker-assisted selection. These results provide clues to explain the strong selection on the artiodactyl MYADM-like repeat locus in sheep, and suggest MYADM family members may be important for RBC morphology in other mammals.
Zinc Fertilization Effects on Seed Cadmium Accumulation in Oilseed and Grain Crops Grown on North Dakota Soils
Rojas-Cifuentes,Gonzalo A; Johnson,Burton L; Berti,Marisol T; Norvell,Wendell A;
Chilean journal of agricultural research , 2012, DOI: 10.4067/S0718-58392012000100019
Abstract: the cd concentration in the seed of crops depends on various soil factors including parent material, texture, ph, soil redox, and salinity. cadmium accumulation also varies among crop species and cultivars within a species. cadmium and zn may have either an antagonistic or a synergistic effect on plant uptake that can be influenced by the soil cd and zn concentrations. the objective was to determine the effect of zn fertilizer additions on the seed cd of nine crops commonly grown in north dakota, usa. studies were conducted at five north dakota locations representing different soil series during 1994 and 1995. in experiment 1, nine crops common in north dakota were grown with and without the addition of 25 kg ha-1 zn fertilizer. among crops evaluated, the greatest seed cd accumulation occurred in flax (linum usitatissimum l.) followed by sunflower (helianthus annuus l.), soybean (glycine max [l.] merr.), and durum wheat (triticum turgidum l. var. durum). in experiment 2, two durum wheats and one flax cultivar were grown under three zn treatments of 0, 5, and 25 kg ha-1. in experiment again flax had the higher seed cd level compared with the two durum varieties. based on the results from both studies, addition of zn fertilizer did not consistently reduce seed cd content, and even when statistically significant, the level of reduction was small and not likely to impact marketability of cd accumulating crops such as flax, sunflower, soybean, and durum.
Zinc Fertilization Effects on Seed Cadmium Accumulation in Oilseed and Grain Crops Grown on North Dakota Soils Efecto de la Fertilización con Zinc en la Acumulación de Cadmio en Semillas Oleaginosas y Cereales producidos en Suelos de Dakota del Norte
Gonzalo A Rojas-Cifuentes,Burton L Johnson,Marisol T Berti,Wendell A Norvell
Chilean Journal of Agricultural Research , 2012,
Abstract: The Cd concentration in the seed of crops depends on various soil factors including parent material, texture, pH, soil redox, and salinity. Cadmium accumulation also varies among crop species and cultivars within a species. Cadmium and Zn may have either an antagonistic or a synergistic effect on plant uptake that can be influenced by the soil Cd and Zn concentrations. The objective was to determine the effect of Zn fertilizer additions on the seed Cd of nine crops commonly grown in North Dakota, USA. Studies were conducted at five North Dakota locations representing different soil series during 1994 and 1995. In Experiment 1, nine crops common in North Dakota were grown with and without the addition of 25 kg ha-1 Zn fertilizer. Among crops evaluated, the greatest seed Cd accumulation occurred in flax (Linum usitatissimum L.) followed by sunflower (Helianthus annuus L.), soybean (Glycine max [L.] Merr.), and durum wheat (Triticum turgidum L. var. durum). In Experiment 2, two durum wheats and one flax cultivar were grown under three Zn treatments of 0, 5, and 25 kg ha-1. In Experiment again flax had the higher seed Cd level compared with the two durum varieties. Based on the results from both studies, addition of Zn fertilizer did not consistently reduce seed Cd content, and even when statistically significant, the level of reduction was small and not likely to impact marketability of Cd accumulating crops such as flax, sunflower, soybean, and durum. La concentración de Cd en semillas depende de varios factores, tanto del suelo como de la planta. Cadmio y Zn pueden tener efectos antagónicos o sinérgicos en la absorción de la planta dependiendo de las concentraciones de Cd y Zn existentes en el suelo. El objetivo de este estudio fue determinar el efecto de la fertilización con Zn en la acumulación de Cd en la semilla de diversos cultivos comúnmente producidos en Dakota del Norte, EE.UU. Dos estudios fueron realizados en cinco localidades en Dakota del Norte que representaban diferentes series de suelo durante 1994 y 1995. Experimento 1, nueve cultivos fueron evaluados con y sin la adición de 25 kg Zn ha-1. Entre los cultivos evaluados, la acumulación más alta de Cd en las semillas ocurrió en lino (Linum usitatissimum L.) seguido por girasol (Helianthus annuus L.), soya (Glycine max [L.] Merr.), y trigo duro (Triticum turgidum L. var. durum). Experimento 2, dos cultivares de trigo duro y un cultivar de lino fueron evaluados bajo tres tratamientos de fertilización, 0, 5, y 25 kg Zn ha-1. En este estudio nuevamente la acumulación de Cd fue más alta en lino.
Predictors of Extubation Success in Patients with Middle Cerebral Artery Acute Ischemic Stroke
Linda C. Wendell,Jonathan Raser,Scott Kasner,Soojin Park
Stroke Research and Treatment , 2011, DOI: 10.4061/2011/248789
Abstract: Introduction. Stroke patients often meet respiratory guidelines for extubation, but uncertainty exists if patients will protect their airway due to impaired mental status. Patients with middle cerebral artery (MCA) acute ischemic stroke (AIS) might have specific predictors of successful extubation. Methods. Retrospective cohort of MCA AIS patients requiring intubation. Results. Thirty-seven MCA AIS patients were extubated successfully and ten failed extubation. Those who successfully extubated had higher extubation composite and eye response Glasgow Coma Scale (GCS) scores compared to those who failed (median 10T (IQR 9T–11T) versus 9.5T (8T–10T), , and 4 (3-4) versus 2.5 (1–3), ). When adjusted for age, admission National Institutes of Health Stroke Scale score and laterality, patients with a GCS score ≥8T trended toward extubating successfully (OR 23.30 (CI 0.94–580.27), ). Conclusions. The GCS score might be important in predicting successful extubation in MCA AIS patients. Further prospective study is warranted to better assess factors predictive of extubation outcome in stroke and other brain-injured patients. 1. Introduction Acute ischemic stroke (AIS) can be complicated by cerebral edema and neurologic deterioration, requiring intubation and mechanical ventilation for respiratory support [1]. Once a stroke patient is mechanically ventilated, respiratory parameters guide the physician in determining when to discontinue mechanical ventilation and airway protection. Current guidelines from a collective task force including the American College of Chest Physicians, the American Association for Respiratory Care, and the American College of Critical Care Medicine recommend that extubation should be considered in patients with sufficient oxygenation, cardiovascular stability, improvement of the primary factor that led to respiratory failure and ventilatory dependence, and the patient’s ability to initiate a breath [2]. Despite best practices, extubation failure occurs in 13–18% of critically ill patients [3–5]. Stroke and other brain-injured patients often meet respiratory guidelines for extubation, but the physician is uncertain if due to impaired mental status, a patient will be unable to protect his or her airway [6]. Weaning parameters (including vital capacity, minute ventilation, maximum inspiratory pressure, and the rapid shallow breathing index) can assist in determining a patient’s ability to ventilate independently but do not predict a patient’s ability to protect his or her airway. Additionally, respiratory weaning parameters within current
Cellular Localization of Gold and Mechanisms of Gold Resistance in Rhodobacter sphaeroides  [PDF]
Hannah Johnson, Ram C. Kafle, Madhusudan Choudhary
Advances in Microbiology (AiM) , 2017, DOI: 10.4236/aim.2017.78047
Abstract: Heavy metal pollution is a worldwide problem with many associated health risks, including bone loss, kidney damage, and several forms of cancer. There is a great need of bioremediation of these toxic metals from the environment, as well as implementing a monitoring system to control the spreading pollution. This study focuses on the bioremediation potential of Rhodobacter sphaeroides in the presence of the toxic gold chloride (AuCl3). Growth characteristics of the bacterial cells exposed to a range of toxic gold concentrations were analyzed through the growth kinetics and the colony forming units under aerobic, photosynthetic, and anaerobic growth conditions. The localization of the gold particles within two cellular fractions, cytoplasm and the plasma membrane, are analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Results of this study demonstrated the photosynthetic growth condition as best suited for the metal tolerance, compared to the aerobic and anaerobic growth conditions. Results also revealed the overall accumulation and localization of gold particles, while not different between the membrane and the cytoplasmic fractions increased at different concentrations of the gold contamination. The results of the localization under photosynthetic growth condition revealed the accumulation reached the highest very quickly, and an overall shift in localization of the gold particles from an equal distribution to an increase within the membrane fraction at the highest concentrations of gold contamination. The localization of the gold particles was validated by Transmission Electron Microscopy (TEM) where the results confirmed the increase in accumulation within the membrane, and photosynthetic membranes, of R. sphaeroides.
Agamben, Hegel, and the State of Exception
Wendell Kisner
Cosmos and History : the Journal of Natural and Social Philosophy , 2007,
Abstract: span style="font-size: 10pt; font-family: Arial"In his account of the state of exception, Agamben repeatedly relies upon what Hegel would have called emWesenslogik/em or #39;transcendental thinking#39;. Because of this reliance, the state of exception appears in Agamben#39;s account as the hidden ground of modern liberal democracies. When conceived as such a ground, it appears to be a condition of possibility that inexorably persists in the modern state. Moreover, within the state of exception all juridical order is suspended, leaving no normative or juridical criteria on the basis of which to decide what the structure of any emergent political order should look like. This means that from the state of exception we can just as easily land in a totalitarian as we can in a liberal democratic or democratic socialist state. Without such criteria - lacking due to the total suspension characterizing the state of exception - Agamben#39;s own alignment with Benjaminian revolutionary messianism over Schmittian authoritarianism is arbitrary, and he leaves us with no basis for making any such decision ourselves. Drawing upon Hegel#39;s dialectic of freedom and his critique of transcendental thought, this paper argues that within the state of exception there is an implicit logic that points the way out of it. Furthermore, it does so in such a way that the state of exception is neither annexed by the structure of a predetermined juridical order along the lines proposed by Schmitt on the one hand nor posited it as a transcendental structure underlying or always preceding modern liberal democracies on the other. This alternative is overlooked by Agamben precisely because of his own insistence upon conceiving of the state of exception in a transcendent way./span
The Category of Life, Mechanistic Reduction, and the Uniqueness of Biology
Wendell Kisner
Cosmos and History : the Journal of Natural and Social Philosophy , 2008,
Abstract: span style="font-size: 10pt; font-family: Arial"The conceptual and ontological determinacies belonging to the category of mechanism, determinacies that began to occupy centre stage within the scientific and philosophical understanding of nature in seventeenth century Europe, continue to tacitly serve as theoretical underpinnings in contemporary conceptualizations of biological life for many scientists as well as philosophers. The conceptual hegemony enjoyed by the category of mechanism since the seventeenth century is even evident in the tacit reliance upon it by some contemporary theorists who otherwise wish to regard themselves as having gone beyond mechanism in their conceptualizations of life. I will argue that such inadvertent reliance is the result of a failure to make these conceptual and ontological determinacies belonging to the category of mechanism explicit through a critical examination of the category of mechanism. In the emScience of Logic/em Hegel carries out precisely such a critical examination and explicit development of the determinacy implicit in mechanism, along with the conceptual and ontological determinacies appropriate to chemistry, teleology and, finally, biological life. Whereas reductive mechanism is commonly criticized by opposing it with an alternate account said to be more ontologically, definitionally, or empirically adequate, Hegel#39;s emScience of Logic/em shows that the category of mechanism considered in itself on its own terms is self-undermining or unsustainable due to its own inherent contradictions. Furthermore, the emLogic/em shows that rendering the implicit determinacy of mechanism explicit necessarily leads to the development of conceptual determinacies that are appropriate to living processes. Because the conceptual development of these latter determinacies results from the inherent unsustainability of mechanism, mechanistic determinacy cannot provide a basis for the conceptualization of life. For this reason, the category of life is rigorously irreducible to that of mechanism. The exegesis provided in this paper of Hegel#39;s account of the category of mechanism and his derivation of the idea of life from that category will provide the justification required for the above claims./span
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