1,470 research outputs found
The future of energy / Brian F. Towler.
No full textIncludes bibliographical references and index.xi, 376 pages:Using the principle that extracting energy from the environment always involves some type of impact on the environment, The Future of Energy discusses...
the sources, technologies, and tradeoffs involved in meeting the world's energy needs. A historical, scientific, and technical background set the stage for discussions on a wide range of energy sources, including conventional fossil fuels like oil, gas, and coal, as well as emerging renewable sources like solar, wind, geothermal, and biofuels. Readers will learn that there are no truly "green" energy sources―all energy usage involves some tradeoffs―and will understand these tradeoffs and other issues involved in using each energy source.Each potential energy source includes discussions of tradeoffs in economics, environmental, and policy implicationsExamples and cases of implementing each technology are included throughout the bookTechnical discussions are supported with equations, graphs, and tablesIncludes discussions of carbon capture and sequestration as emerging technologies to manage carbon dioxide emission
A Relational Theory of Authorship
No full textOver the years we have heard the debate as to whether authorship emanates solely from the individual or from the cultural context in which they inhabit. Writers such as Professors Woodmansee, Jaszi and Cohen have asserted a cultural theory of authorship. On one hand, there is the liberal philosophy of autonomous creativity evidenced in the notion of a "romantic author" (after the period known as romanticism). On the other hand we have more of a communitarian notion – that the author acts in a cultural context and authorship to some extent must be linked back to the social existence within which the author is situated.\ud
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This article argues that for too long we have privileged the notion of the romantic author so much so that it is hard to argue for any other approach to copyright than one that focuses primarily on the author and their assignees such as publishers or associated commercialising agents such as recording companies. Furthermore it suggests that this approach fits awkwardly with the burgeoning networked society fuelled by the Internet to the point where it threatens innovation and the potential for productivity. To this end the article argues that we should more explicitly acknowledge the contribution of culture to authorship and more so the role of each and every individual in assisting and nurturing that authorship, as well as the contribution of users to creativity through consumptive, productive and transformative use of copyright works
Tissue engineering of a tracheal substitute
No full textLectin histochemistry and scanning electron microscopy (SEM) was used to assess the growth and characterise the differentiation of human respiratory epithelial cells (REC) cultured on two biomaterial scaffolds. The first scaffold, based on a hyaluronic acid derivative, was observed to be non-adhesive for REC. This lack of adhesion was found to be unrelated to the presence of the hyaluronic acid binding domain on the surface of isolated REC. The other scaffold, consisting of equine collagen, was observed to encourage REC spreading and adhesion. Positive Ulex Europaeus agglutinin (UEA) lectin staining of this preparation indicated the presence of ciliated REC on the scaffold surface. However, the marked decrease in peanut agglutinin (PNA) positive staining, relative to that of control cultures and native tissue, indicates a dedifferentiation of the secretory cells in monolayer. SEM analysis of REC cultured on the collagen scaffold confirmed the presence of ciliated cells thereby validating the UEA positive staining. The presence of both established and developing cilia was also verified. This indicates that collagen biomaterials are appropriate for the tissue engineering of REC. Furthermore, that UEA and PNA staining is a useful tool in the characterisation of cells cultured on biomaterials, therefore helpful in identifying biomaterials that are suitable for specific tissue engineering purposes.
The culture of REC at an air liquid interface (ALI) was investigated. Both conventional ALI inserts and the Biofleece scaffold were used. The cells grown the on conventional inserts became multilayered and showed some degree of ciliation after the period of ten days. The cells grown on the Biofleece scaffold became necrotic and died due to nutrient deprivation. The use of ALI culture techniques on scaffold materials needs to be adjusted to allow for sufficient nutrient supply to the cells.
The Biofleece scaffold was found to be suitable for the tissue engineering of cartilage in vitro. Constructs with a cartilage-like morphology were generated with the scaffold after two weeks in culture. The tissue-engineered cartilage was found to contain a higher number of cells and less extracellular matrix (ECM) than the native tissue controls. Suction seeding techniques were used to improve the distribution of cells within the scaffold and thereby increase the overall efficiency of cartilage tissue engineering within the scaffold. Alcian blue (AB) and Papanicolau (PN) stains of the tissue engineered cartilage described two distinct regions within the constructs, namely the developed cartilage-like region and the developing region. The latter is thought to be areas in which the cartilage cells are yet to fully remodel the scaffold material and deposit their own “native” ECM. However, the Biofleece scaffold material was observed to loose 40-50% of its initial volume during the tissue engineering process over a period of two weeks. Thus the degradation of the Biofleece scaffold exceeds the rate of maturation of the cartilage tissue within the scaffold. This rapid biodegradation is most likely a result of matrixmetalloproteinase (MMP), in particular collagenase, production by the maturing chondrocytes. This reduction in size means that the Biofleece scaffold is not an appropriate material for the tissue engineering of a trachea. The optimal biomaterial for the tissue engineering of a trachea would degrade at a rate equal too, or slower than, the time taken for the cells within the scaffold to mature into functional tissue.
The co-culture of REC and chondrocytes was achieved through the use of matrigel as a basement membrane replacement (note that direct growth of REC on cartilage tissue has been observed to be difficult). The co-cultured constructs were not stable because the Biofleece scaffold degrades at a high rate in the presence of both cell types. The constructs were observed to shrink to approximately 35-30% of the original dimensions in a period of 3-7 days. The reason for this accelerated degradation is not known but is most likely the result of severe MMP production by the two cell types when in combination.
It was concluded that the characterisation procedures used in this study (histochemical staining, fluorescent staining and scanning electron microscopy) for both REC and chondrocyte tissue engineered constructs are appropriate for this and further studies. The chondrocyte seeding methodologies in particular are a useful tool for tissue engineering. This study succeeds in many ways to investigate the tissue engineering of a tracheal substitute by detailing how REC and chondrocytes can be cultured on biomaterials and assessed for tissue development. However, the study does not deliver such a viable substitute as an end product. The primary reason for this outcome is the rapid degradation of the Biofleece scaffold materialLectin Histochemie und Elektronenmikroskopie wurden benutzt, um das Wachstum von humanen respiratorischen Epithelzellen (RECs), welche auf zwei Biomaterialien kultiviert wurden, festzusetzen und ihren Differenzierungsgrad zu bestimmen. Das erste Trägermaterial, welches auf einem Hyaluronsäurederivat basiert, ließ keine Anheftung der RECs zu. Diese fehlende Anheftung ließ sich jedoch nicht zurückführen auf das Vorhandensein der Hyaluronsäure bindenden Domaine auf der Oberfläche isolierter RECs. Das andere Trägermaterial, aus Pferdekollagen hergestellt, zeigte dagegen eine verstärkte Teilungsaktivität und Anheftung der REC. Die positive Ulex Europaeus Agglutinin (UEA) Lectin Färbung dieser Proben ließ die Anwesenheit von mit Zilien versehenen RECs auf der Trägerstoffoberfläche vermuten. Darüber hinaus weist das im Vergleich zu Kontrollkulturen und nativem Gewebe deutliche Nachlassen der positiven Peanut Agglutinin–Färbereaktion auf eine Dedifferenzierung der sekretorischen Zellen in der Monolayer-Kultur hin. Die rasterelektronenmikroskopische Untersuchung der auf dem Kollagenbiomaterial kultivierten RECs bestätigte das Auftreten von Zellen mit Zilien und damit auch die Aussagekräftigkeit der positiven UEA–Färbung. Dies zeigt somit, dass Biomaterialien aus Kollagen für das Tissue Engineering von RECs geeignet sind und dass sowohl die UEA–als auch die PNA–Färbung geeignete Methoden zur Charakterisierung von Zellen darstellen, die auf Biomaterialien kultiviert wurden. Somit helfen sie bei der Identifizierung von Biomaterialien für bestimmte Einsatzgebiete im Tissue Engineering.
Des weiteren wurde die Kultivierung von RECs auf einem Air liquid interface (ALI) untersucht, wobei sowohl der konventionelle ALI–Einsatz als auch das Biovliesmaterial zum Einsatz kamen. Dabei wuchsen die Zellen auf dem konventionellen Einsatz in Multilayern und zeigten nach einem Zeitraum von 10 Tagen einen bestimmten Anteil an Ziliierung. Die Zellen auf dem Biovlies dagegen wurden nekrotisch und gingen schließlich an Nahrungsmangel ein. Deshalb muss der Einsatz von ALI–Kulturtechniken bei Trägermaterialien dementsprechend modifiziert werden, dass eine ausreichende Versorgung der Zellen mit Nährstoffen gewährleistet ist.
Für das in vitro–Tissue Engineering von Knorpel erwies sich das Biovlies jedoch als geeignet. Mit ihm konnten nach zwei Wochen Kulturzeit Konstrukte mit einer knorpelähnlichen Morphologie erzeugt werden. Dabei zeigte sich, dass der Tissue Engineering–Knorpel eine höhere Zellzahl bei reduzierter extrazellulärer Matrix (ECM) aufwies als vergleichbares natives Kontrollgewebe. Dabei wurden Saugtechniken benutzt, um die Verteilung der Zellen im Trägerstoff zu verbessern. Die Alzian – Blau – Färbung (AB) und Papanicolau – Färbung (PN) zeigten bei dem Tissue Engineering–Knorpel zwei unterschiedliche Regionen innerhalb des Konstrukts, nämlich eine knorpelähnliche bereits entwickelte Region und eine sich entwickelnde Region. Bei letzterer dürfte es sich wohl um Gebiete handeln, in denen Zellen noch im Begriff sind, den Trägerstoff vollends umzubauen und ihre eigene „native“ ECM abzulagern. Nichtsdestoweniger büßte das Biovlies während des Tissue Engineering Prozesses über einen Zeitraum von zwei Wochen annähernd 40-50 % seines anfänglichen Volumens ein. Somit übersteigt das Ausmaß der Degradation des Biovlieses das des Heranreifens von Knorpelgewebe in dem Trägermaterial. Diese schnelle Biodegradation ist am ehesten das Ergebnis der Aktivität von Matrixmetalloproteinasen (MMP), insbesondere der Kollagenase, welche von reifenden Chondrozyten produziert wird. Diese Schrumpfung bedeutet also, dass das Biovlies kein geeignetes Material für das Tissue Engineering der Trachea darstellt. Denn ein optimales Biomaterial für das Tissue Engineering der Trachea sollte sich innerhalb derselben Zeit bzw. über einen längeren Zeitraum hinweg abbauen, als innerhalb desjenigen, den die sich in dem Trägermaterial befindlichen Zellen benötigen, um zu funktionalem Gewebe heranzureifen.
Durch den Einsatz von Matrigel als Ersatz für die Basalmembran konnte eine Kokultur aus RECs und Chondrozyten etabliert werden (wobei anzumerken ist, dass sich direktes Wachstum von RECs auf Knorpelgewebe als problematisch erweist). Die Konstrukte aus Kokulturen waren nicht stabil, da das Biovlies in Anwesenheit beider Zelltypen hochgradig abgebaut wird. Innerhalb von 3–7 Tagen schrumpften die Konstrukte auf ca. 35–50 % ihrer Ausgangsgröße zusammen. Der Grund für diesen beschleunigten Abbau ist unbekannt, jedoch ist am ehesten eine ausgeprägte Produktion von MMP durch die beiden Zellarten anzunehmen, sobald diese in Kombination vorliegen.
Insgesamt lässt sich sagen, dass die Methoden zur Zell- und Gewebecharakterisierung, welche in dieser Studie benutzt wurden (histochemische Färbungen, Fluoreszenzfärbung und Elektronenmikroskopie) sowohl für mit RECs als auch mit Chondrozyten hergestellte Konstrukte für die vorliegende Arbeit als auch zukünftige Studien als geeignet anzusehen sind. Diese Studie hat in vielerlei Hinsicht erfolgreich das Tissue Engineering einer Luftröhre untersuchen können, indem sie im Detail aufzeigt, wie RECs und Chondrozyten auf Biomaterialien kultiviert und für das Tissue Engineering eingesetzt werden können. Trotzdem kann diese Arbeit kein einsetzbares Ersatzmaterial als Endprodukt liefern. Der Hauptgrund für dieses Ergebnis ist in erster Linie in dem schnellen Abbau des Biovlieses als Trägermaterial zu sehen
Creighton University Window Spring 1991
No full textTHE PLATTE: A TREASURE AT RISK / THE FLAT PLATTE: AN IMPERILED TREASURE OF NEBRASKA, PLAINS
Dr. John Schalles, Creighton biologist, and Don Doll, S.J., photographer, take you on a tour of the Platte River system, a three-state treasure of which everyone wants a piece. Page 4.
SHAKESPEARE IN THE PARK / TRY A NIGHT OUT... ON THE LAWN ... WITH SHAKESPEARE
Brian Kokensparger and photographers Don Doll, S.J., Tim Fitzgerald of University of Nebraska at Omaha, and Kent Sievers show you how Shakespeare is done on a midsummer's night as you'll like it. Page 14.
SHE SWINGS FOR THE FENCES / COACH HIGGINS SWINGS FOR THE FENCES FOR CREIGHTON, FAMILY
Mary Higgins has brought the Lady Jay softball team to national prominence. For her, family or Creighton are the same — she goes for the home run all the time. Read about this enthusiastic top Lady Jay. Page 18.
THE BLACKROBE IN LITERATURE / THE JESUITS IN LITERATURE: SALVOS FROM WRITERS' PENS
Author Bob Reilly researches the references to Jesuits in literature that trace back to their beginnings. Sometimes it's not flattering, but it's always intriguing. Page 21.3
The Future of Energy
No full textUsing the principle that extracting energy from the environment always involves some type of impact on the environment, The Future of Energy discusses the sources, technologies, and tradeoffs involved in meeting the worlds energy needs. A historical, scientific, and technical background set the stage for discussions on a wide range of energy sources, including conventional fossil fuels like oil, gas, and coal, as well as emerging renewable sources like solar, wind, geothermal, and biofuels. Readers will learn that there are no truly "green" energy sources-all energy usage involves some tradeoffs-and will understand these tradeoffs and other issues involved in using each energy source. Each potential energy source includes discussions of tradeoffs in economics, environmental, and policy implications Examples and cases of implementing each technology are included throughout the book Technical discussions are supported with equations, graphs, and tables Includes discussions of carbon capture and sequestration as emerging technologies to manage carbon dioxide emission
Thomas Boyd: Lost Author of the Lost Generation
No full textMentored by F. Scott Fitzgerald and Sinclair Lewis and published under the renowned Scribner editor Maxwell Perkins, Thomas Boyd attained only modest success as a novelist and biographer. He is known most widely for his World War I novel Through the Wheat, which critics, praising its realistic depiction of war and battle, compared to The Red Badge of Courage. How does a writer like Boyd, with his prominent literary friends, political ideals, professional aspirations, complicated personal life, and early death, fall so easily into obscurity? In this first full biography of Thomas Boyd, Brian Bruce explores the events of Boyd\u27s life and rescues him from the realm of insignificance.https://ideaexchange.uakron.edu/uapress_publications/1098/thumbnail.jp
Feeding Skills and Physiological Response to Feeding in Infants With Complex Congenital Heart Disease
No full textAbstract
Date Presented 3/30/2017
The objectives of this study were to characterize the feeding skills of infants with complex congenital heart disease and to measure physiological parameters during feeding. Results suggest clinical signs of decreased feeding skill and physiological changes that remain up to 60 min after the feeding.
Primary Author and Speaker: Kelly Tanner
Additional Authors and Speakers: Lauren Justice
Contributing Authors: Tondi Harrison, Maria Anderson, Brian F. Joy</jats:p
Botulinum neurotoxin for head and neck disorders/ [edited by] Andrew Blitzer, Brian E. Benson, Diana N. Kirke
No full textIncludes bibliographical references and index"Senior author Dr. Andrew Blitzer is an internationally renowned pioneer on the use of botulinum neurotoxin for functional disorders, with unparalleled expertise on this topic. Joined by co-editors Brian Benson and Diana Kirke, with multidisciplinary contributors, Botulinum Neurotoxin for Head and Neck Disorders Second Edition fills a gap in the medical literature. The unique textbook focuses on the use of botulinum neurotoxins for functional disorders of the head and neck, though with some aesthetic indications. The second edition reflects the latest advances and understanding of existing and emerging applications for botulinum neurotoxins, including new treatment paradigms, revised pharmacology, and an updated review of the literature in all chapters. Twenty superbly illustrated chapters cover the management of hyperfunctional, pain, and hypersecretory syndromes of the head and neck. Hyperfunctional motor disorders are discussed in chapters focused on blepharospasm, facial dystonia, Meige syndrome, oromandibular dystonia, spasmodic dysphonia (laryngeal dystonia), and cervical dystonia. Specific treatment approaches for pain are addressed in chapters on migraine and chronic daily tension headaches, temporomandibular disorders, and trigeminal neuralgia. The treatment of autonomic nervous system disorders is covered in chapters dedicated to Frey syndrome, facial hyperhydrosis, and sialorrhea"--Pharmacology of Botulinum Neurotoxins / Muna I. Bitar, Nikita Kohli, Maya Samman, and Andrew Blitzer -- Botulinum Neurotoxin for Blepharospasm / Amit Patel, Andrew Blitzer, and Boris L. Bentsianov -- Botulinum Neurotoxin for Facial Dystonia / Scott M. Rickert, Amy P. Wu, and Andrew Blitzer Botulinum -- Neurotoxin for Meige Syndrome / Niv Mor and Andrew Blitzer -- Botulinum Neurotoxin for Oromandibular Dystonia / Daniel Novakovic and Ajay E. Chitkara -- Botulinum Neurotoxin for Spasmodic Dysphonia / Phillip C. Song, Lucian Sulica, and Andrew Blitzer -- Botulinum Neurotoxin for Cervical Dystonia / Tanya K. Meyer, Joel Guss, and Ronda E. Alexander -- Botulinum Neurotoxin for Hemifacial Spasm and Facial Synkinesis / Lesley French Childs, Daniel Novakovic, and Scott R. Gibbs -- Botulinum Neurotoxin for Hyperfunctional Facial Lines / Brian E. Benson, Diana N. Kirke, and Andrew Blitzer -- Botulinum Neurotoxin for Upper and Lower Esophageal Spasm / Nwanmegha Young and Brian E. Benson -- Botulinum Neurotoxin for Palatal Myoclonus / Ajay E. Chitkara, Catherine F. Sinclair, and Daniel Novakovic -- Botulinum Neurotoxin for Temporomandibular Disorders, Masseteric Hypertrophy, and Cosmetic Masseter Reduction / Michael Z. Lerner and Andrew Blitzer -- Botulinum Neurotoxin Therapy in the Laryngopharynx / Craig H. Zalvan, Phillip C. Song, Nwanmegha Young, and Andrew Blitzer -- Botulinum Neurotoxin for Migraine / Rachel Kaye, Jerome Schwartz, Brian E. Benson, and William J. Binder -- Botulinum Neurotoxin for Chronic Tension Headache / Nwanmegha Young and Brian E. Benson -- Botulinum Neurotoxin for Trigeminal Neuralgia / Elizabeth Guardiani, Andrew Blitzer, Lesley French Childs, and Ronda E. Alexander -- Botulinum Neurotoxin for Frey's Syndrome / Rachel Kaye, Andrew Blitzer, and Brian E. Benson -- Botulinum Neurotoxin for Facial Hyperhidrosis / Diana N. Kirke, Daniel Novakovic, and Andrew Blitzer -- Botulinum Neurotoxin for Sialorrhea / Brianna K. Crawley, Scott M. Rickert, Senja Tomovic, and Andrew Blitzer -- Botulinum Neurotoxin for Radiation-Induced Spasm and Pain / Diana N. Kirke, Brian E. Benson, and Tanya K. Meyer1 online resourc
The Total Synthesis of Dragmacidins D and F
No full textThe dragmacidins are an emerging class of bis(indole) natural products isolated from deep-water marine organisms. Although there has been a substantial effort to prepare the simple piperazine dragmacidins, little synthetic work has been done in the area of the pyrazinone-containing family members, dragmacidins D, E, and F. These compounds are particularly interesting due to their complex structures and broad range of biological activity.
A highly convergent strategy to access dragmacidin D has been developed. In this approach, sequential halogen-selective Suzuki couplings were used to assemble the carbon scaffold of the natural product. After executing a highly optimized sequence of final events, the first completed total synthesis of dragmacidin D was achieved.
An enantiodivergent strategy for the total chemical synthesis of both (+)- and (-)-dragmacidin F from a single enantiomer of quinic acid has been developed and successfully implemented. Although unique, the synthetic routes to these antipodes share a number of key features, including novel reductive isomerization reactions, Pd(II)-mediated oxidative carbocyclization reactions, halogen-selective Suzuki couplings, and high-yielding late-stage Neber rearrangements.
The formal total syntheses of dragmacidin B, trans-dragmacidin C, and dihydrohamacanthin A are described. In addition, preliminary studies involving a novel approach for the preparation of dragmacidin E are reported.</p
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