1,631 research outputs found
Public Perceptions of Genetically Modified Foods: Americans Know Not What They Eat
No full textBiotechnology stands to be a defining technology in the future of food and agriculture. Proponents argue that science and industry are poised to bring consumers a wide variety of products that have potential for meeting basic food needs, as well as delivering a wide-range of health, environmental and economic benefits. Opponents counter that the potential exists for unintended consequences, ranging from ecological disruption to adverse human health implications, and that these risks are not fully understood. Fundamental questions exist, however, regarding the general public’s position on food products derived with the use of biotechnology. To address these questions, the Food Policy Institute addressed consumers using computer assisted telephone interviews (CATI) system, a public phone survey of a sample selection of 1203 U.S. residents was administered between March and April 2001. The questionnaire was developed to address perceived gaps in the current literature on American consumer awareness, acceptance, and perceptions of food biotechnology and to serve as the basis for a set of longitudinal studies that will be able to track public opinion over time.Food Policy Institute Publication Number RR-0302-001
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Review of \u3ci\u3eI\u27ll Be Here in the Morning: The Songwriting Legacy of Townes Van Zandt\u3c/i\u3e by Brian T. Atkinson
No full textTexas\u27s Townes Van Zandtwas a musician\u27s musician whose fame grew after his 1996 death. Brian T. Atkinson, contributor to the Austin AmericanStatesman, Texas Music, Lone Star, American Songwriter, and No Depression, has woven together a collection of interviews from Van Zandt\u27s contemporaries and friends, as well as his musical heirs-singer-songwriters who grew up too late to have known the troubled author of Pancho and Lefty, Tecumseh Valley, and Lungs but who admired his dark, poetic lyrics
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
Programmed Death-1 Culls Peripheral Accumulation of High-Affinity Autoreactive CD4 T Cells to Protect against Autoimmunity
No full textSummarySelf-reactive CD4 T cells are incompletely deleted during thymic development, and their peripheral seeding highlights the need for additional safeguards to avert autoimmunity. Here, we show an essential role for the coinhibitory molecule programmed death-1 (PD-1) in silencing the activation of high-affinity autoreactive CD4 T cells. Each wave of self-reactive CD4 T cells that escapes thymic deletion autonomously upregulates PD-1 to maintain self-tolerance. By tracking the progeny derived from individual autoreactive CD4 T cell clones, we demonstrate that self-reactive cells with the greatest autoimmune threat and highest self-antigen affinity express the most PD-1. Reciprocally, PD-1 deprivation unleashes high-affinity self-reactive CD4 T cells in target tissues to exacerbate neuronal inflammation and autoimmune diabetes. Reliance on PD-1 to actively maintain self-tolerance may explain why exploiting this pathway by cancerous cells and invasive microbes efficiently subverts protective immunity, and why autoimmune side effects can develop after PD-1-neutralizing checkpoint therapies
Supernova shrapnel: nearby supernovae and dust transport in the ISM
No full textThe last 2 decades have seen the proposal, detection, and confirmation of live ^60Fe radioisotopes from an extra-solar source on Earth, showing an event outside the Solar System directly delivered material to the Earth since its formation. This work examines the possible sources for the ^60Fe and models the passage of the material from its source through the Solar System to the ocean floor. We consider the production and deposition on Earth of isotopes with half-lives in the range 10^5 to 10^8 years that might provide signatures of nearby stellar explosions, extending previous analyses of Core-Collapse Supernovae (CCSNe) to include Electron-Capture Supernovae (ECSNe), Super-Asymptotic Giant Branch (SAGBs) stars, Thermonuclear/Type Ia Supernovae (TNSNe), and Kilonovae/Neutron Star Mergers (KNe). We revisit previous estimates of the ^60Fe and ^26Al signatures, and extend these estimates to include ^244Pu and ^53Mn. We show that (i) the ^60Fe yield rules out the TNSN and KN interpretations, (ii) the ^60Fe signals highly constrain a SAGB interpretation but do not completely them rule out, (iii) are consistent with a CCSN origin, and (iv) are highly compatible with an ECSN interpretation.
We also examine various influences on the path of interstellar dust carrying ^60Fe from a SN through the Heliosphere, with the aim of estimating the final global distribution on the ocean floor. We study the influences of magnetic fields, angle of arrival, wind and ocean cycling of SN material on the concentrations at different locations. We find that the passage of SN material through the mesosphere/lower thermosphere (MLT) is the greatest influence on the final global distribution, with ocean cycling causing lesser alteration as the SN material sinks to the ocean floor. SN distance estimates in previous works that assumed a uniform distribution are a good approximation. Including the effects on surface distributions, we estimate a distance of 46^(+10)_(-6) pc for an ECSN progenitor. We note that the SN dust retains directional information to within 1^(circ) through its arrival in the inner Solar System, so that SN debris deposition on inert bodies such as the Moon will be anisotropic, and thus could in principle be used to infer directional information.
Lastly, we examine the various influences on the path of dust within a SN remnant (SNR) to determine when/if the dust decouples from the plasma, how much it is sputtered, and where within the ejecta the dust is located. We find that the inclusion of Rayleigh-Taylor (R-T) instabilities are important in studying dust survival as R-T instabilities influence the location of the SN's reverse shock. We also find the presence of a magnetic field within the shocked ISM material will limit the passage of SN dust grains reflecting them or trapping within the heart of the SNR.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-08-01The student, Brian Fry, accepted the attached license on 2016-07-04 at 15:08.The student, Brian Fry, submitted this Dissertation for approval on 2016-07-04 at 15:23.This Dissertation was approved for publication on 2016-07-08 at 16:47.DSpace SAF Submission Ingestion Package generated from Vireo submission #9750 on 2016-11-10 at 12:24:50Made available in DSpace on 2016-11-10T18:39:16Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-07-08Embargo set by: Seth Robbins for item 95449
Lift date: 2018-11-10T18:39:22Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 95449
Lift date: 2018-11-10T18:43:22Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 95449 on 2018-11-11T10:15:45Z
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
Give growth and macroeconomic stability in Russia a chance - harden budgets by eliminating nonpayments
No full textThe authors analyze the links between Russia's disappointing growth performance in the second half of the 1990s, its costly and unsuccessful stabilization, the macroeconomic meltdown of 1998, and the spectacular rise of non-payments. Non-payments flourished in an environment of fundamental inconsistency between a macroeconomic policy geared at sharp disinflation, and a microeconomic policy of bailing enterprises out through soft budget constraints. Heavy untargeted implicit subsidies flowing through the non-payments system (amounting to 10 percent of GDP annually) have stifled growth, contributed to the August 1998 meltdown, through their impact on public debt, and have made at best a questionable contribution to equity. Dismantling this system must be a top priority, along with promoting enterprise restructuring and growth (by hardening budget constraints) and medium-term macroeconomic stability (by reducing the size of subsidies). Getting the government out of the non-payments system means settling all appropriately controlled budgetary expenditures on time, and in cash, and eschewing spending arrears, thereby setting an example for enterprises, and laying the groundwork for eliminating tax offsets at all levels of government, and insisting on cash tax payments. To stop energy-related subsidies, would require not only that the government pay its own energy bills on time, and in cash, but also that the energy monopolies be empowered to disconnect non-paying clients. This will enable the government to insist that the energy monopolies in turn pay their own taxes in full, and on time.Banks&Banking Reform,Public Sector Economics&Finance,Economic Theory&Research,Payment Systems&Infrastructure,Environmental Economics&Policies,Banks&Banking Reform,Environmental Economics&Policies,Municipal Financial Management,Public Sector Economics&Finance,Economic Theory&Research
Subject-specific identification of three dimensional foot shape deviations using statistical shape analysis
No full textAbstract: The high prevalence of foot pain, and its relation to foot shape, indicates the need for an expert system to identify foot shape abnormalities. Yet, to date, no such expert system exists that examines the full 3D foot shape and produces an intuitive explanation of why a foot is abnormal. In this work, we present the first such expert system that satisfies those goals. The system is based on the concept of model-based outlier detection: a statistical shape model (SSM) is generated from 186 3D optical foot scans of healthy feet. This model acts as a knowledge base which is then parameterized by one's demographic characteristics (e.g., age, weight, height, shoe size) through a multivariate regression. This regression introduces model flexibility as it allows the model to be fine tuned to a specific individual. This fine tuned model is then used as a baseline to which the individual's 3D foot scan can be compared using standard statistical tests (e.g. t-tests). These statistical tests are performed at each vertex along the foot surface to identify the degree and location of shape outliers. Our expert system was validated on foot scans from patients with hallux valgus and abnormal foot arches. As expected, our results varied per patient, confirming that feet with the same clinical classification still show high shape variability. Additionally, the foot shape abnormalities identified by our system not only agreed with the expected location and severity of the tested foot deformities, but our analysis of the full 3D foot shape was able to completely characterize the extent of those abnormalities for the first time. These results show that the combination of statistical shape modelling, multivariate regression, and statistical testing is powerful enough to perform outlier detection for 3D foot shapes. The resulting insights provided by this system could prove useful in both shoe design and clinical diagnosis. (C) 2020 Elsevier Ltd. All rights reserved
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