1,704 research outputs found
Dr. Kevin Kuswa - Faculty Author Interview
No full textDr. Kevin Kuswa, Director of Debate in the department of Rhetoric and Communication Studies, discusses “Blowback the Enemy T/here: Errors, Terrors, and the Rhetorical Agenda of WMDs”, a chapter in the recently published book, Entertaining Fear: Rhetoric and the Political Economy of Social Control. Dr. Kuswa has been teaching a class on terrorism and security since 2002, focusing on perhaps the most important social dynamic of our time, the rhetoric of fear. Kuswa’s chapter focuses on understanding the “logics and discourses through the trope of ‘blow-back,\u27” a phrase describing the ways a state’s aggressive military action can circle back to confront the state itself
Establishing the developmental function of the rhamnogalacturonan II component of pectin
No full textThe primary plant cell wall consists of a complex set of polysaccharides including pectin, cellulose and hemicelluloses that are critical for normal plant development. There are three major forms of pectin, rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II) and homogalacturonan (HGA). Of these, the pectic polysaccharide RG-II, is the least abundant but the most complex. Despite this, RG-II is highly conserved among vascular plants, suggesting animportant function which is dependent upon structure. RG-II consists of four structurally welldefined side chains attached to a backbone of 1,4-linked galacturonic acid (GalA) residues and exists predominately as a dimer in plant cell walls. RG-II function has yet to be identified; however, mutations affecting RG-II structure have severe growth and development defects. 3-deoxy-D-manno-2-octulosonic acid (Kdo) is a rarely found sugar and is a component of the RGII side chain C. Kdo biosynthesis has been well characterised and a number of Kdo synthesis genes identified in Arabidopsis. Traditional gene knockout approaches to study the effect of disrupting Kdo biosynthesis have been limited by the apparent lethality of these mutants. Alternative approaches using partial knockout, inducible gene silencing and chemical approaches have being employed with the primary aim of specifically altering the structure of RG-II to determine the developmental function of RG-II. By combination of a GAL4/VP16 expression system and ALCR/alcA ethanol-switch to achieve temporal and spatial control of transgene expression, it has been possible to generate a genetic tool kit consisting of a series of Arabidopsis lines in which it should be possible to disrupt Kdo biosynthesis in specific tissues at strictly defined developmental stages. As a proof of concept the J0951/iKdsB line, in which expression of an AtKdsB antisense sequence is restricted to the epidermis and root cap in the presence of ethanol, is shown to be almost completely devoid of root hairs when grown under induced conditions. This result is suggestive of a role for RG-II in tip growth processes and is consistent with the phenotypes of null mutants in which a failure in pollen tube elongation results in gametophyte lethality. In silico and in vitro approaches are used to investigate the potential application of an inhibitor of AtKdsB, 2?-deoxy Kdo, as a tool for the disruption of CMP-Kdo synthesis in plants. Using homology modelling the Arabidopsis and E. coli enzymes are shown to have a near identical active site conformation. Using recombinantly expressed AtKdsB in enzyme kinetic and inhibition studies the substrate analogue 2?-deoxy-Kdo was shown to be a potent in vitro inhibitor of AtKdsB with a Ki of 1.26 ± 0.15 ??, consistent with measures of the Kd made by isothermal titration calorimetry (ITC) analysis. The 2?-deoxy-Kdo was subsequently applied in vivo and results in a severe inhibition of cell elongation of Arabidopsis root cells that can be partially rescued by either Kdo or boron. It is likely that 2?-deoxy-Kdo application disrupts CMP-Kdo biosynthesis with consequences for RG-II structure and dimer formation
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
Continuous metadata flows for distributed multimedia
No full textThe practical use of temporal multimedia has increased markedly in recent years as enabling technologies for the distribution and streaming of media have become available. As a part of this trend, hypermedia systems and models have adapted accordingly to incorporate such distributed multimedia for presentation. Structured interpretation of information has long been a fundamental feature of both open hypermedia systems and knowledge systems. Metadata, in its many forms, has become the cornerstone for providing this structured knowledge above and beyond basic data and information. This thesis presents the rationale and requirements for continuous metadata, which supports the metadata accompanying distributed multimedia throughout the lifecycle of streamed media, from generation, through distribution, to presentation. Throughout this process it is the temporal and continuous nature of the metadata which is paramount. A conceptual framework for continuous metadata is proposed to encapsulate these principles and ideas. Continuous metadata and the associated framework enable the development, in particular, of real-time, collaborative, semantically enriched distributed multimedia applications. Experience building one such system using continuous metadata is evaluated within the framework. An ontology is developed for the system to enable the collation, distribution, and presentation of structure aiding navigation of multimedia, and it is shown how continuous metadata utilising the ontology can be distributed using multicas
Understanding Regional Growth Dynamics in JAPAN: Panel Cointegration Approach Utilizing The PANIC Method
No full textThis study aims at understanding regional growth dynamics in Japan using nonstationary panel data. Since the panel unit root test does not adequately produce a detailed picture of the development of Japanese prefectures, we follow a panel cointegration approach using the PANIC method. We find that there is one common source of growth to which prefectures attach different long-run weights and that the per capita real income of follower-prefectures will catch up to that of leader-prefectures. Using the concept of relative convergence, we find that although the poor stay poor, the relative income gap will narrow substantially in the future.β-convergence, Common trends, Panel unit root test, PANIC method, Relative convergence, Japan
FIGURE 11. Live Siren sphagnicola specimens. A in Unraveling Siren (Caudata: Sirenidae) systematics and description of a small seepage specialist
No full textFIGURE 11. Live Siren sphagnicola specimens. A Holotype specimen from Okaloosa Co., Florida (UF Herp 185209). B Dorsal view of an adult found in shallow water where specimens were buried in the sandy bottom. C Dorsolateral view of an adult found in a deeper creek with deep muck deposits where specimens were found by digging through sphagnum root masses and fluid muck. D Juvenile from a shallow, sand-bottomed creek. E Adult hypertrophic male with a partially regenerated tail.Published as part of Fedler, Matthew T., Enge, Kevin M. & Moler, Paul E., 2023, Unraveling Siren (Caudata: Sirenidae) systematics and description of a small seepage specialist, pp. 351-378 in Zootaxa 5258 (4) on page 372, DOI: 10.11646/zootaxa.5258.4.1, http://zenodo.org/record/778432
The evolution of root-zone moisture capacities after deforestation:A step towards hydrological predictions under change?
No full textThe core component of many hydrological systems, the moisture storage capacity available to vegetation, is impossible to observe directly at the catchment scale and is typically treated as a calibration parameter or obtained from a priori available soil characteristics combined with estimates of rooting depth. Often this parameter is considered to remain constant in time. Using long-term data (30-40 years) from three experimental catchments that underwent significant land cover change, we tested the hypotheses that: (1) the root-zone storage capacity significantly changes after deforestation, (2) changes in the root-zone storage capacity can to a large extent explain post-treatment changes to the hydrological regimes and that (3) a time-dynamic formulation of the root-zone storage can improve the performance of a hydrological model.A recently introduced method to estimate catchment-scale root-zone storage capacities based on climate data (i.e. observed rainfall and an estimate of transpiration) was used to reproduce the temporal evolution of root-zone storage capacity under change. Briefly, the maximum deficit that arises from the difference between cumulative daily precipitation and transpiration can be considered as a proxy for root-zone storage capacity. This value was compared to the value obtained from four different conceptual hydrological models that were calibrated for consecutive 2-year windows. It was found that water-balance-derived root-zone storage capacities were similar to the values obtained from calibration of the hydrological models. A sharp decline in root-zone storage capacity was observed after deforestation, followed by a gradual recovery, for two of the three catchments. Trend analysis suggested hydrological recovery periods between 5 and 13 years after deforestation. In a proof-of-concept analysis, one of the hydrological models was adapted to allow dynamically changing root-zone storage capacities, following the observed changes due to deforestation. Although the overall performance of the modified model did not considerably change, in 51% of all the evaluated hydrological signatures, considering all three catchments, improvements were observed when adding a time-variant representation of the root-zone storage to the model. In summary, it is shown that root-zone moisture storage capacities can be highly affected by deforestation and climatic influences and that a simple method exclusively based on climate data can not only provide robust, catchment-scale estimates of this critical parameter, but also reflect its time-dynamic behaviour after deforestation.</p
Local government chief executives’ everyday hauntings : towards a theory of organizational ghosts
No full textThis paper develops a theory of organizational ghosts, a concept that describes the haunted and burdensome aspects of organizational life and in particular of leadership action. The concept of organizational ghosts is not offered as yet another metaphor, a lens through which to analyse particular organizations. Rather, I offer my discussion of ghosts as a theoretical concept that explains how inheritances of the past haunt the relations and struggles of the present. I tell a ghostly tale of the everyday leadership and learning practices of UK local government chief executives, and provide an exploration of organizational ghosts as a contribution to the growing interest in the action in the shadows, atmospheres, margins and boundaries of organizations. Drawing upon an ethnographic study of UK local councils, and embracing the multiplicity and heterogeneity of organizational ghosts, the paper considers the theoretical, political and ethical stakes involved in taking ghosts seriously. Its contribution is to show how ghosts are insinuated in organizations and to highlight leaders as figures who are both willing agents and uneasy hosts of hauntings, and to point to the mediating role of leaders in handling confrontations between the past, the present and the future.Peer reviewe
Gold, fiat money and price stability
No full textThe classical gold standard has long been associated with long-run price stability. But short-run price variability led critics of the gold standard to propose reforms that look much like modern versions of price-path targeting. This paper uses a dynamic stochastic general equilibrium model to examine price dynamics under alternative policy regimes. In the model, an inflation target provides more short-run price stability than does the gold standard and, although it introduces a unit root into the price level, it leads to as much long-term price stability as does the gold standard for horizons shorter than 30 years. Relative to these regimes, Fisher's compensated dollar reduces price level and inflation uncertainty by an order of magnitude at all horizons.> The classical gold standard has long been associated with long-run price stability. But short-run price variability led critics of the gold standard to propose reforms that look much like modern versions of price-path targeting. This paper uses a dynamic stochastic general equilibrium model to examine price dynamics under alternative policy regimes. In the model, an inflation target provides more short-run price stability than does the gold standard and, although it introduces a unit root into the price level, it leads to as much long-term price stability as does the gold standard for horizons shorter than 30 years. Relative to these regimes, Fisher's compensated dollar reduces price level and inflation uncertainty by an order of magnitude at all horizons.Inflation (Finance) ; Monetary policy ; Gold standard
The Yield of Ten-Year T-Bonds: Stumbling Towards a 'Good' Forecast
No full textDue to their status as "the" benchmark yield for the world's largest government bond market and its importance for US monetary policy, the interest in a "good" forecast of the constant maturity yield of the 10-year U.S. Treasury bond ("T-bond yields") is immense. This paper assesses three univariate time series models for forecasting the yield of T-bonds: It shows that a simple SETAR model proves to be superior to the random walk and an ARMA model. However, dividing the sample of bond yields, dating from 1962 to 2005, into a training sample and a test sample reveals the forecast to be biased. A new bias-corrected version is developed and forecasts for March 2005 to February 2006 are presented. In addition to point estimates forecast limits are also given. --T-bond,times series,10-year yield,TAR model,bias-correction,non-linear time series
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