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Hurdles
Kinds of Hurdles Selected AbstractsA Consultant's Perspective on the Regulatory Hurdles to Adaptive TrialsBIOMETRICAL JOURNAL, Issue 4 2006Cyrus R. Mehta Abstract This is a discussion of the following two papers appearing in this special issue on adaptive designs: ,A regulatory view on adaptive/flexible clinical trial design' by H. M. James Hung, Robert T. O'Neill, Sue-Jane Wang and John Lawrence and ,Confirmatory clinical trials with an adaptive design' by Armin Koch. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Trade Liberalization and the Fiscal Squeeze: Implications for Public InvestmentDEVELOPMENT AND CHANGE, Issue 3 2003Barsha Khattry This article examines the impact of trade liberalization on the level and structure of government expenditures across countries, with particular emphasis on low income countries. It develops the argument that the policies employed during trade liberalization have resulted in a fiscal squeeze as a result of declining tax revenues and rising interest expenditures. To surmount this fiscal hurdle, expenditures on physical capital, which have negligible political ramifications, have been reduced. Other more politically sensitive expenditures, such as spending on social capital, have been financed by incurring additional debt. However, additional debt has exerted upward pressure on interest payments, further exacerbating the fiscal situation. The statistical analysis carried out to examine the evidence uses panel data for eighty developing and industrialized countries over the period 1970,98 and employs a fixed,effects regression framework to account for country,specific characteristics. The results indicate that trade liberalization has indeed resulted in declining revenues and higher interest expenditures and that these factors have contributed to the observed decline in infrastructure spending. [source] Body size changes in ground beetle assemblages , a reanalysis of Braun et al. (2004)'s dataECOLOGICAL ENTOMOLOGY, Issue 5 2006GÁBOR L. LÖVEI Abstract 1.,Data in Braun et al.'s (2004) recent paper on size trends in ground beetles (Carabidae) are re-analysed, after re-classifying the species according to feeding categories. 2.,When ground beetles are classified as predatory species, mixed feeders or herbivores, and evaluated separately, the size trends indicate group-specific differences. Most of these do not support the efficiency-specialisation hypothesis. 3.,Taxonomic groups rarely fit into one ecological category and ecological analyses should explicitly consider this hurdle. [source] Whip use and race progress are associated with horse falls in hurdle and steeplechase racing in the UKEQUINE VETERINARY JOURNAL, Issue 5 2004G. L. PINCHBECK Summary Reasons for performing study: Falls during racing present a risk of injury to both horse and jockey and a risk of fatality to horses. Objectives: To use video recordings of races to describe the circumstances surrounding horse falls at hurdle and steeplechase fences and to identify and quantify within-race risk factors for horse falls in National Hunt racing in the UK. Methods: A retrospective, matched, nested case-control study using video recordings of races was conducted on 6 UK racecourses. Cases and controls were matched on both race type and jump number at which the fall occurred. Conditional logistic regression analysis was used to examine the univariable and multivariable relationship between predictor variables and the risk of falling. Results: The risk of falling was significantly associated with whip use and race progress. Horses which were being whipped and progressing through the race were at greater than 7 times the risk of falling compared to horses which were not being whipped and which had no change in position or lost position through the field. Conclusions: This study has identified whip use and the position of the horse with respect to others in the field as potential risk factors for horse falls. Potential relevance: If these findings are confirmed by the use of intervention trials (e.g. with whip-free or restricted whip use races), modifications could be introduced which would reduce the frequency of horse falls, leading to improved equine welfare. [source] Group motivational enhancement therapy as an adjunct to inpatient treatment for eating disorders: a preliminary study,EUROPEAN EATING DISORDERS REVIEW, Issue 4 2008Helen Y. Dean Abstract Difficulties in fostering eating disorder (ED) patients' motivations to overcome their illness are widely considered to be a major hurdle in the course of successful treatment. However, no previous study has assessed the use of interventions specifically designed to target poor motivation amongst patients with illnesses that are severe enough to warrant hospitalisation. Objective A brief Motivational Enhancement Therapy (MET) group programme for inpatient ED sufferers was developed and evaluated. Method Forty two consecutive inpatients were sequentially allocated to treatment groups. Twenty three inpatients completed a four session MET group programme in addition to routine hospital care. A control group of 19 participants completed treatment as usual (TAU). Results Despite an absence of significant differences between the MET and the TAU groups on the overall formal outcome measures, there were nevertheless differences between the groups. Specifically, the MET groups appeared to foster longer term motivation and engagement, and to promote treatment continuation. Conclusion The results tentatively suggest that MET could be valuable for the treatment of inpatient eating disorder patients and further research is warranted. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association. [source] CROSSING RELATIONSHIPS AMONG ANCIENT AND EXPERIMENTAL SUNFLOWER HYBRID LINEAGESEVOLUTION, Issue 3 2000Loren H. Rieseberg Abstract., Reproductive barrier formation between newly derived hybrid taxa and their parental species represents a major evolutionary hurdle. Here, I examine the development of a sterility barrier during hybrid speciation by examining the fertility of progeny from all combinations of crosses involving three experimentally synthesized sunflower hybrid lineages, their natural hybrid counterpart, Helianthus anomalus, and their parents, H. annuus and H. petiolaris. Crosses between the parental species and H. anomalus generated almost completely sterile offspring (pollen viability < 5%; seed set < 1%). A fairly strong sterility barrier also has developed between three hybrid lineages and both parental species (pollen viability 11.1,41.6%; seed set 0.84,20.1%). In contrast, the three hybrid lineages are almost fully interfertile (pollen viabilities 83.1,88.6%; seed set 72.1,75.3%), as predicted by molecular mapping studies that indicate they have converged on a similar set of gene combinations and chromosomal rearrangements. A modest decline in compability is observed in crosses between the three hybrid lineages and H. anomalus (pollen viabilities 64.1,70.7%; seed set 37,43%), a result that agrees well with prior data demonstrating significant congruence between the genomes of the natural and experimental hybrid lineages. These observations not only indicate that reproductive isolation can arise as a by-product of fertility selection in hybrid populations, but also testify to the repeatability of this mode of speciation. [source] Low-Distortion Holographic Data Storage Media Using Free-Radical Ring-Opening PolymerizationADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Kyongsik Choi Abstract Holographic data storage, due to its potential to increase capacity beyond one terabyte per disk, is tipped to be one of the next generation optical data storage technologies. Polymer-based systems are leading candidates due to their high dynamic range, high sensitivities, and flexible and easy production, and yet polymerization-shrinkage-induced distortion is a major hurdle for its reliable use. In this paper, a new free radical polymerization holographic recording medium, based on low shrink cyclic allylic sulfides (LS-CASs) ring-opening monomers, is proposed and demonstrated. The percentage of volume shrinkage is measured to be 0.02%, with refractive index (RI) contrast of (1.01,±,0.5),×,10,3. The measured volume shrinkage is, to the authors' best knowledge, the best reported so far in the literature. Other parameters such as sensitivity, dynamic range, and dark reaction properties are also measured, where the values can be optimized with high RI functional groups without sacrificing the low shrinkage. [source] Alternative approaches to obtain optimal bid values in contingent valuation studies and to model protest zeros.HEALTH ECONOMICS, Issue 2 2001Estimating the determinants of individuals' willingness to pay for home care services in day case surgery Abstract The use of day case surgery has increased rapidly as an alternative to inpatient surgery. Little is known, however, about the value of day case surgery to patients. The aim of this paper was to develop a contingent valuation survey to investigate how individuals value the costs of shifting from inpatient to day case surgery based on home care services. Using the willingness to pay (WTP) approach, two kinds of sequential experiments are compared: the maximum likelihood recursion (MLR) method and the C-optimal sequential procedure. The goal of sequential experimentation is to find bid values that provide the maximum possible information about the parameters of the WTP distribution, especially when the sample size is small. The C-optimal sequential procedure is shown to be an improvement, in terms of the statistical precision in small samples, over the MLR method. In addition, the paper presents a double hurdle (DH) approach for modelling the determinants of individuals' WTP. Using data from a contingent valuation survey conducted in 1996 on patients selected from the Day Case Surgery Unit in a hospital in the region of Catalonia, we argue that participation in the market offered and the level of consumption, that is, people's WTP, should be treated as individual choices. The results show that income and sex are related to WTP. Also, in this study, a clear presence of starting-point bias, introduced by the bid offered, was found. It is concluded that the WTP technique is potentially useful in evaluating health care programmes, although it is important to note that the criteria used to find an optimal design (in our model to minimize the asymptotic variance of the estimator used) may be restrictive from an economic point of view. Copyright © 2001 John Wiley & Sons, Ltd. [source] Stretchable, Large-area Organic ElectronicsADVANCED MATERIALS, Issue 20 2010Tsuyoshi Sekitani Abstract Stretchability will significantly expand the application scope of electronics, particularly large-area electronics,displays, sensors, and actuators. If arbitrary surfaces and movable parts could be covered with stretchable electronics, which is impossible with conventional electronics, new classes of applications are expected to emerge. A large hurdle is manufacturing electrical wiring with high conductivity, high stretchability, and large-area compatibility. This Review describes stretchable, large-area electronics based on organic field-effect transistors for applications to sensors and displays. First, novel net-shaped organic transistors are employed to realize stretchable, large-area sensor networks that detect distributions of pressure and temperature simultaneously. The whole system is functional even when it is stretched by 25%. In order to further improve stretchability, printable elastic conductors are developed by dispersing single-walled carbon nanotubes (SWNTs) as dopants uniformly in rubbers. Further, we describe integration of printable elastic conductors with organic transistors to construct a rubber-like stretchable active matrix for large-area sensor and display applications. Finally, we will discuss the future prospects of stretchable, large-area electronics with delineating a picture of the next-generation human/machine interfaces from the aspect of materials science and electronic engineering. [source] Delivery of Nucleic Acids via Disulfide-Based Carrier SystemsADVANCED MATERIALS, Issue 32-33 2009Sonja Bauhuber Abstract Nucleic acids are not only expected to assume a pivotal position as "drugs" in the treatment of genetic and acquired diseases, but could also act as molecular cues to control the microenvironment during tissue regeneration. Despite this promise, the efficient delivery of nucleic acids to their side of action is still the major hurdle. One among many prerequisites for a successful carrier system for nucleic acids is high stability in the extracellular environment, accompanied by an efficient release of the cargo in the intracellular compartment. A promising strategy to create such an interactive delivery system is to exploit the redox gradient between the extra- and intracellular compartments. In this review, emphasis is placed on the biological rationale for the synthesis of redox sensitive, disulfide-based carrier systems, as well as the extra- and intracellular processing of macromolecules containing disulfide bonds. Moreover, the basic synthetic approaches for introducing disulfide bonds into carrier molecules, together with examples that demonstrate the benefit of disulfides at the individual stages of nucleic acid delivery, will be presented. [source] Multiscale Galerkin method using interpolation wavelets for two-dimensional elliptic problems in general domainsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2004Gang-Won Jang Abstract One major hurdle in developing an efficient wavelet-based numerical method is the difficulty in the treatment of general boundaries bounding two- or three-dimensional domains. The objective of this investigation is to develop an adaptive multiscale wavelet-based numerical method which can handle general boundary conditions along curved boundaries. The multiscale analysis is achieved in a multi-resolution setting by employing hat interpolation wavelets in the frame of a fictitious domain method. No penalty term or the Lagrange multiplier need to be used in the present formulation. The validity of the proposed method and the effectiveness of the multiscale adaptive scheme are demonstrated by numerical examples dealing with the Dirichlet and Neumann boundary-value problems in quadrilateral and quarter circular domains. Copyright © 2003 John Wiley & Sons, Ltd. [source] Nominal debt and inflation stabilizationINTERNATIONAL JOURNAL OF ECONOMIC THEORY, Issue 4 2009Shigeto Kitano E63; F41 The "fiscal theory of currency crises" (Daniel 2001; Corsetti and Ma,kowiak 2005, 2006) claims that with long-term nominal debt, a government can delay the timing of an inevitable currency crisis that results from a fiscal shock. The present paper shows that, in contrast, long-term nominal debt might have destabilizing effects when a government introduces an inflation stabilization policy. It is shown that a stabilization policy that is successful in the absence of long-term nominal debt can cause a crisis when long-term nominal debt exists. The model implies that a government with a large stock of long-term nominal debt must overcome a high fiscal hurdle for a successful stabilization policy. This difficulty is avoidable if long-term debt is indexed to inflation. [source] A paradigm for the treatment of prostate cancer bone metastases based on an understanding of tumor cell,microenvironment interactionsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2005Robert D. Loberg Abstract The pliability of cancer cells to mutate into several different phenotypes in an attempt to find one that will survive and colonize at the metastatic site is a tremendous "hurdle" to overcome in designing novel cancer therapeutics. New targets of therapy are essential if we are to effectively overcome the evasiveness of cancer. The interaction between the tumor cell and the surrounding microenvironment creates a vicious cycle that perpetuates disease survival and progression. The future of cancer therapy resides in the ability to focus on the recruited and exploited relationships of the cancer cell with the host environment. These therapies target cancer cell growth early and interrupt the vicious cycle that is created by the tumor cells interacting with bone components by inhibiting osteoclasts, osteoblasts, stromal cells, and endothelial cells. They alter the bone microenvironment, creating a hostile "soil" that prevents the "seed" from developing into bone metastases and represent a potential new platform for the development of prostate cancer therapeutics. © 2005 Wiley-Liss, Inc. [source] Prediction of the relaxation behavior of amorphous pharmaceutical compounds.JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2003Abstract Variability in the time to crystallization is a major technical and economic hurdle in using amorphous solids in dosage forms. It is hypothesized that amorphous solids "age", and that the older they are, the more relaxed they are and the higher the probability of crystallization. At present, there is no method that allows the "effective age" of an amorphous raw material to be assessed relative to its unrelaxed initial condition. A method has been developed that may satisfy this unmet need and provide a first step in subsequent investigation of the crystallization "event". This method consists of using master curves to enable the determination of the effective age (,aging') of an amorphous compound given normal excursions in storage conditions. The present study shows that master curves can be prepared for different storage conditions and subsequently be used to predict the relaxation or aging behavior of amorphous compounds with expected variations in storage conditions. Given the constraint that the system remain within the area enclosed by the equilibrium supercooled liquid line and the glass on the enthalpy,temperature diagram, experimental results using indomethacin and salicin as model compounds show that master curves can be used to predict aging behavior under nonisothermal conditions, with temperature excursions as large as 10°C. The nonisothermal relaxation behavior can be modeled by combining the Kohlrausch,Williams,Watts (KWW) stretched exponential function, the relaxation function, and a shift factor. In addition, a model was developed that extends the range of applicability to time/temperature regions in which partial crystallization occurs. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:1464,1472, 2003 [source] Functionalizing the interior of dendrimers: Synthetic challenges and applicationsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2003Stefan Hecht Abstract Chemists' fascination with dendrimers mainly originates from their unique architecture and its exploitation for the design of well-defined functional macromolecules. Depending on the nature of the synthesis, functionalization is traditionally introduced at the core, the periphery, or both. However, the specific incorporation of functional groups at the interior layers, i.e., generations, represents a considerable synthetic hurdle that must be overcome for the full potential of dendrimers to be realized. This review covers recent advances in this emerging frontier of dendrimer science with a particular focus on covalent modifications. Monomer design, syntheses, and properties of various dendritic backbone types are discussed. Internal functionalization dramatically increases the degree of complexity that can be implemented into a dendrimer macromolecule and, therefore, promises to lead to smart materials for future applications in bio- and nanotechnologies. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1047,1058, 2003 [source] Taxes and the Efficiency-Rent Extraction Trade-offJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 5 2006ANIL ARYA This paper presents an adverse selection model in which progressive taxation enhances productive efficiency by encouraging a principal (buyer) to be less aggressive in contracting with an agent (seller). Wary of padded cost budgets, the buyer employs a hurdle-rate procurement policy. With a low cost hurdle, the buyer keeps greater profits when transactions are undertaken but trade occurs less often. While the hurdle is unaffected by a flat tax, a progressive tax tilts the buyer's preference: the buyer's benefit from a lower hurdle becomes less pronounced, since the marginal increase in his profits is muted in after-tax terms. The result is increased trade and the possibility of Pareto improvements. [source] Pesticide residues in food,acute dietary exposure,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2004Denis Hamilton Abstract Consumer risk assessment is a crucial step in the regulatory approval of pesticide use on food crops. Recently, an additional hurdle has been added to the formal consumer risk assessment process with the introduction of short-term intake or exposure assessment and a comparable short-term toxicity reference, the acute reference dose. Exposure to residues during one meal or over one day is important for short-term or acute intake. Exposure in the short term can be substantially higher than average because the consumption of a food on a single occasion can be very large compared with typical long-term or mean consumption and the food may have a much larger residue than average. Furthermore, the residue level in a single unit of a fruit or vegetable may be higher by a factor (defined as the variability factor, which we have shown to be typically ×3 for the 97.5th percentile unit) than the average residue in the lot. Available marketplace data and supervised residue trial data are examined in an investigation of the variability of residues in units of fruit and vegetables. A method is described for estimating the 97.5th percentile value from sets of unit residue data. Variability appears to be generally independent of the pesticide, the crop, crop unit size and the residue level. The deposition of pesticide on the individual unit during application is probably the most significant factor. The diets used in the calculations ideally come from individual and household surveys with enough consumers of each specific food to determine large portion sizes. The diets should distinguish the different forms of a food consumed, eg canned, frozen or fresh, because the residue levels associated with the different forms may be quite different. Dietary intakes may be calculated by a deterministic method or a probabilistic method. In the deterministic method the intake is estimated with the assumptions of large portion consumption of a ,high residue' food (high residue in the sense that the pesticide was used at the highest recommended label rate, the crop was harvested at the smallest interval after treatment and the residue in the edible portion was the highest found in any of the supervised trials in line with these use conditions). The deterministic calculation also includes a variability factor for those foods consumed as units (eg apples, carrots) to allow for the elevated residue in some single units which may not be seen in composited samples. In the probabilistic method the distribution of dietary consumption and the distribution of possible residues are combined in repeated probabilistic calculations to yield a distribution of possible residue intakes. Additional information such as percentage commodity treated and combination of residues from multiple commodities may be incorporated into probabilistic calculations. The IUPAC Advisory Committee on Crop Protection Chemistry has made 11 recommendations relating to acute dietary exposure. Copyright © 2004 Society of Chemical Industry [source] Electric current as a control variable in the electrospinning processPOLYMER ENGINEERING & SCIENCE, Issue 7 2006Ravikant Samatham In the electrospinning process submicron-diameter polymer fibers can be produced when a high potential difference is applied to a polymer drop suspended at the tip of a capillary. The electrospinning process is affected by a wide range of parameters, because of which controlling the properties of the fibers is difficult. This is the major hurdle in the development of practical applications of electrospun fibers along with its low productivity. Here we are proposing to use the electric current in the electrospinning process to control the "quality of the fibers". Electrospinning of a solution of polyacrylonitrile in dimethylformamide (PAN/DMF) was done by applying a programmed variable flow rate at different constant voltages. The electric current in the process was measured in real time. Four types of jet regimes were observed, electric current and the morphology of the fibers corresponding to these regimes were analyzed. A relation between the electric current, type of jet and morphology of the fibers has been established. The mechanical properties of electrospun fiber mats were also measured by a tensile testing method. POLYM. ENG. SCI. 46:954,959, 2006. © 2006 Society of Plastics Engineers [source] The European Union Constitution on Border Checks, Asylum, and ImmigrationPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2004Article first published online: 15 DEC 200 The Treaty Establishing a Constitution for Europe was signed by the heads of government of the 25 European Union member states and three candidate states on 29 October 2004. The Treaty in effect is the proposed constitution, a long and elaborate document comprising 448 Articles (grouped into four Parts, with additional divisions into Titles, Chapters, and Sections, but numbered consecutively throughout) and 29 Protocols,annexes to the Treaty. Five articles and four protocols are concerned with issues of border control, immigration, and asylum policy. The articles are found in the chapter titled Area of Freedom, Security and Justice in Part III of the Treaty (The Policies and Functioning of the Union). These are reproduced below, along with one of the protocols (number 21). (Of the other protocols concerned with migration, one adds to the Treaty the provisions of the Schengen Acquis, the agreement among all EU members except the United Kingdom and Ireland, plus the non-EU states Norway and Iceland, to eliminate border controls at their common frontiers, and requires acceptance of the Acquis by any new member. Two other protocols set out reservations on the part of the UK and Ireland on border control and asylum matters,basically, an "opt-in" stance, allowing their participation in Treaty provisions on a case-by-case basis.) The constitution is highly detailed in scope but often vague in content, merely specifying topics on which policies will be developed or laws enacted. Thus the "common immigration policy" that is signaled in Article III-267 is yet to be shaped, and the Treaty offers few hints of what it may look like. A reluctance on the part of member states to cede sovereignty in the area of immigration is not limited to the British Isles. It is seen also in the retained right of all members to restrict non-EU labor migrants (Article III-267, Para. 5) and to conclude bilateral agreements on border crossing with non-EU states (Protocol 21). It is notable that the Treaty, while stressing that all nationals of member states are citizens of the Union with the right "to move and reside freely" within its territory, does not attempt to harmonize conditions or procedures under which migrants can acquire citizenship: indeed, it says nothing at all on the matter. (A "framework law," mentioned at various points in the text, is a law that prescribes the result to be achieved but leaves to each member state "the choice of form and methods.") Actual adoption of the constitution requires ratification by the governments of all EU members. If this demanding hurdle is passed (requiring parliamentary approval or, in some cases, a referendum), the constitution would come into force on 1 November 2006,or after the final ratification, if later. Under Article IV-443, if the treaty is ratified by four-fifths of members within the two years but is rejected by one or more states, "the matter shall be referred to the European Council",the quarterly summit meeting of heads of government. [source] Increased aggregation propensity of IgG2 subclass over IgG1: Role of conformational changes and covalent character in isolated aggregatesPROTEIN SCIENCE, Issue 9 2010Heather Franey Abstract Aggregation of human therapeutic antibodies represents a significant hurdle to product development. In a test across multiple antibodies, it was observed that IgG1 antibodies aggregated less, on average, than IgG2 antibodies under physiological pH and mildly elevated temperature. This phenomenon was also observed for IgG1 and IgG2 subclasses of anti-streptavidin, which shared 95% sequence identity but varied in interchain disulfide connectivity. To investigate the structural and covalent changes associated with greater aggregation in IgG2 subclasses, soluble aggregates from the two forms of anti-streptavidin were isolated and characterized. Sedimentation velocity analytical ultracentrifugation (SV-AUC) measurements confirmed that the aggregates were present in solution, and revealed that the IgG1 aggregate was composed of a predominant species, whereas the IgG2 aggregate was heterogeneous. Tertiary structural changes accompanied antibody aggregation as evidenced by greater ANS (8-Anilino-1-naphthalene sulfonic acid) binding to the aggregates over monomer, and differences in disulfide character and tryptophan environments between monomer, oligomer and aggregate species, as observed by near-UV circular dichroism (CD). Differences between subclasses were observed in the secondary structural changes that accompanied aggregation, particularly in the intermolecular ,-sheet and turn structures between the monomer and aggregate species. Free thiol determination showed ,2.4-fold lower quantity of free cysteines in the IgG1 subclass, consistent with the 2.4-fold reduction in aggregation of the IgG1 form when compared with IgG2 under these conditions. These observations suggested an important role for disulfide bond formation, as well as secondary and tertiary structural transitions, during antibody aggregation. Such degradations may be minimized using appropriate formulation conditions. [source] TOWARDS GLOBAL SCHOLARSHIP IN PUBLIC AFFAIRSPUBLIC ADMINISTRATION, Issue 3 2010GAYLORD GEORGE CANDLER One can imagine two futures for public administration, public management and public service around the world. A first would be what we see as a continuation of the status quo: with public administration essentially continuing as a series of national discourses, with perhaps a bit of cross-fertilization, but with this characterized by a classic core-periphery model. The preferable model, outlined in this paper, would see the development of an integrated community of scholars of public affairs. At least three hurdles need to be overcome to arrive at this integrated community. A first concerns the tension in the periphery between an epistemic nationalism and epistemic colonialism. The second hurdle to be overcome concerns the central role of the American literature in intellectual discourse in public administration. A third hurdle is more specific to public administration: what Canadian Iain Gow has referred to as public administration's profile, as ,une science empirique par excellence'. [source] The New Racial Calculus: Electoral Institutions and Black Representation in Local LegislaturesAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 1 2010Melissa J. Marschall In this study we revisit the question of black representation on city councils and school boards using a novel substantive and methodological approach and longitudinal data for a sample of over 300 boards and councils. Conceptualizing black representation as a two-stage process, we fit Mullahy's hurdle Poisson models to explain whether and to what extent blacks achieve representation in local legislatures. We find that while the size of the black population and electoral arrangements matter more than ever, especially for overcoming the representational hurdle, the extent to which the black population is concentrated is also strongly associated with black council representation. Further, whereas black resources and opportunities to build "rainbow" coalitions with Latinos or liberal whites are marginally if at all related to black legislative representation, we find that legislative size is an underappreciated mechanism by which to increase representation, particularly in at-large systems, and is perhaps the best predictor of moving towards additional representation. [source] The Role of Intellectual Property in the Global Challenge for ImmunizationTHE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 4 2006Tarcísio Hardman Reis The contemporary scenario of international immunization is focused on the implementation of vaccination programs in developing countries, which demonstrates obvious similarities with the policy "access to medicines" under the Agreement on Trade-Related Aspects of Intellectual Property Rights. However, the debate on immunization involves distinct elements and presents different concerns and obstacles, which will be presented throughout this study. Three introductory remarks need to be made in order to place intellectual property (IP) as a core problem of global immunization. The first is that immunization is a world priority. The second is that the global immunization challenge faces the hurdle of the poverty gap. Finally, IP plays a controversial role in the implementation of immunization programs in less developed countries. [source] Molecular Markers and Targeted Therapy of Skin Rejection in Composite Tissue AllotransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2010T. Hautz Skin rejection remains a major hurdle in reconstructive transplantation. We investigated molecular markers of skin rejection with particular attention to lymphocyte trafficking. Skin biopsies (n = 174) from five human hand transplant recipients were analyzed for rejection, characteristics of the infiltrate and lymphocytic adhesion markers. The cellular infiltrate predominantly comprised CD3+ T cells. CD68, Foxp3 and indoleamine 2, 3-dioxygenase expression and the CD4/CD8 increased with severity of rejection. Lymphocyte adhesion markers were upregulated upon rejection, intercellular adhesion molecule-1 and E-selectin correlated best with severity of rejection. Guided by the findings, a specific E- and P-selectin inhibitor was investigated for its effect on skin rejection in a rat hind limb allotransplant model. While efomycine M (weekly s.c. injection into the graft) alone had no effect, long-term allograft survival was achieved when combined with antithymocyte globulin and tacrolimus (control group without efomycine M rejected at postoperative day [POD] 61 ± 1). Upregulation of lymphocyte trafficking markers correlates with severity of skin rejection and time after transplantation in human hand transplantation. Blocking E- and P-selectin in the skin holds potential to significantly prolong limb allograft survival. [source] Results of Gal-Knockout Porcine Thymokidney XenograftsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2009A. D. Griesemer Clinical transplantation for the treatment of end-stage organ disease is limited by a shortage of donor organs. Successful xenotransplantation could immediately overcome this limitation. The development of homozygous ,1,3-galactosyltransferase knockout (GalT-KO) pigs removed hyperacute rejection as the major immunologic hurdle to xenotransplantation. Nevertheless, GalT-KO organs stimulate robust immunologic responses that are not prevented by immunosuppressive drugs. Murine studies show that recipient thymopoiesis in thymic xenografts induces xenotolerance. We transplanted life-supporting composite thymokidneys (composite thymus and kidneys) prepared in GalT-KO miniature swine to baboons in an attempt to induce tolerance in a preclinical xenotransplant model. Here, we report the results of seven xenogenic thymokidney transplants using a steroid-free immunosuppressive regimen that eliminated whole-body irradiation in all but one recipient. The regimen resulted in average recipient survival of over 50 days. This was associated with donor-specific unresponsiveness in vitro and early baboon thymopoiesis in the porcine thymus tissue of these grafts, suggesting the development of T-cell tolerance. The kidney grafts had no signs of cellular infiltration or deposition of IgG, and no grafts were lost due to rejection. These results show that xenogeneic thymus transplantation can support early primate thymopoiesis, which in turn may induce T-cell tolerance to solid organ xenografts. [source] Burning mouth syndrome and psychological disordersAUSTRALIAN DENTAL JOURNAL, Issue 2 2009LM Abetz Abstract Burning mouth syndrome (BMS) is an oral dysaesthesia that causes chronic orofacial pain in the absence of a detectable organic cause. The aetiology of BMS is complex and multifactorial, and has been associated in the literature with menopause, trigger events and even genetic polymorphisms. Other studies have found evidence for mechanisms such as central and peripheral nervous system changes, with clinical and laboratory investigations supporting a neuropathologic cause. These physiological explanations notwithstanding, there is still much evidence that BMS aetiology has at least some psychological elements. Somatoform pain disorder has been suggested as a mechanism and factors such as personality, stress, anxiety, depression and other psychological, psychosocial and even psychiatric disorders play a demonstrable role in BMS aetiology and symptomatology. In order to treat BMS patients, both physiological and psychological factors must be managed, but patient acceptance of possible components of psychological disease basis is a major hurdle. Clinical signs of patient stress, anxiety or depression are a useful reinforcement of clinical discussions. The current paper proposes a number of clinical signs that may be useful for both clinical assessment and subsequent patient discussions by providing visible supportive evidence of the diagnosis. [source] Efficient phase separation and product recovery in organic-aqueous bioprocessing using supercritical carbon dioxideBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2010Christoph Brandenbusch Abstract Biphasic hydrocarbon functionalizations catalyzed by recombinant microorganisms have been shown to be one of the most promising approaches for replacing common chemical synthesis routes on an industrial scale. However, the formation of stable emulsions complicates downstream processing, especially phase separation. This fact has turned out to be a major hurdle for industrial implementation. To overcome this limitation, we used supercritical carbon dioxide (scCO2) for both phase separation and product purification. The stable emulsion, originating from a stereospecific epoxidation of styrene to (S)-styrene oxide, a reaction catalyzed by recombinant Escherichia coli, could be destabilized efficiently and irreversibly, enabling complete phase separation within minutes. By further use of scCO2 as extraction agent, the product (S)-styrene oxide could be obtained with a purity of 81% (w/w) in one single extraction step. By combining phase separation and product purification using scCO2, the number of necessary workup steps can be reduced to one. This efficient and easy to use technique is generally applicable for the workup of biphasic biocatalytic hydrocarbon functionalizations and enables a cost effective downstream processing even on a large scale. Biotechnol. Bioeng. 2010;107:642,651. © 2010 Wiley Periodicals, Inc. [source] Understanding the properties of aerobic sludge granules as hydrogelsBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2009Thomas Seviour Abstract Aerobic sludge granules are larger, denser microbial aggregates than activated sludge flocs with a smoother and more regular surface, which facilitates greater wastewater treatment intensity. Factors important in their growth are still poorly understood, which is an impediment to the construction and operation of full-scale aerobic sludge granule processes. Data in this article obtained with granules treating an abattoir wastewater provide evidence that aerobic sludge granules are hydrogels. The results also demonstrate a method for characterizing macromolecular associations. The rheological profile of these granules was found to be analogous with that of typical polymer gels. Water uptake or swelling reflects an equilibrium between granule elastic modulus and osmotic pressure, whereby uptake is increased by reducing solute concentration or the elastic modulus. A weakening of the extracellular polymeric substance (EPS) matrix as demonstrated with mechanical spectroscopy was induced by several environmental factors including temperature, pH and ionic strength. Uniform and elastic deformation was observed at low strain. Enzymatic degradation studies indicate that proteins and ,-polysaccharides were the major granule structural materials. The aerobic sludge granules in the current study were therefore protein,polysaccharide composite physical hydrogels. While aerobic sludge granules treating an abattoir wastewater are used as a case study, many of the fundamental principles detailed here are relevant to other granulation processes. The paradigm established in this study can potentially be applied to better understand the formation of aerobic sludge granules and thus overcome a hurdle in the acceptance of aerobic sludge granulation as an alternative to more traditional wastewater treatment processes. Biotechnol. Bioeng. 2009;102: 1483,1493. © 2008 Wiley Periodicals, Inc. [source] Acidosis and Catecholamine Evaluation Following Simulated Law Enforcement "Use of Force" EncountersACADEMIC EMERGENCY MEDICINE, Issue 7 2010Jeffrey D. Ho MD ACADEMIC EMERGENCY MEDICINE 2010; 17:E60,E68 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, Law enforcement authorities are often charged with controlling resisting suspects. These encounters sometimes result in the sudden and unexpected death of the suspect. Drug intoxication, excited delirium syndrome, or excessive uses of force are factors that are often blamed, but sometimes the mechanism of these deaths is not fully understood. It is possible that worsening acidosis or excessive catecholamine release play a part. The objective of this study was to determine the effect on markers of acidosis and catecholamines of various tasks intended to simulate common arrest-related situations. Methods:, Subjects were assigned to one of five task groups: 1) a 150-meter sprint and wall hurdle (simulated flight from arrest); 2) 45 seconds of striking a heavy bag (simulated physical resistance); 3) a 10-second TASER X26 electronic control device exposure; 4) a fleeing and resistance exercise involving a law enforcement dog (K-9); or 5) an oleoresin capsicum (OC) exposure to the face and neck. Baseline serum pH, lactate, potassium, troponin I, catecholamines, and creatine kinase (CK) were evaluated. Serum catecholamines, pH, lactate, and potassium were sampled immediately after the task and every 2 minutes for 10 minutes posttask. Vital signs were repeated immediately after the task. Serum CK and troponin I were evaluated again at 24 hours posttask. Results:, Sixty-six subjects were enrolled; four did not complete their assigned task. One subject lost the intravenous (IV) access after completing the task and did not have data collected, and one subject only received a 5-second TASER device exposure and was excluded from the study, leaving 12 subjects in each task group. The greatest changes in acidosis markers occurred in the sprint and heavy bag groups. Catecholamines increased the most in the heavy bag group and the sprint group and increased to a lesser degree in the TASER, OC, and K-9 groups. Only the sprint group showed an increase in CK at 24 hours. There were no elevations in troponin I in any group, nor any clinically important changes in potassium. Conclusions:, The simulations of physical resistance and fleeing on foot led to the greatest changes in markers of acidosis and catecholamines. These changes may be contributing or causal mechanisms in sudden custodial arrest-related deaths (ARDs). This initial work may have implications in guiding applications of force for law enforcement authorities (LEAs) when apprehending resisting subjects. [source] The Glass Cliff: Evidence that Women are Over-Represented in Precarious Leadership PositionsBRITISH JOURNAL OF MANAGEMENT, Issue 2 2005Michelle K. Ryan There has been much research and conjecture concerning the barriers women face in trying to climb the corporate ladder, with evidence suggesting that they typically confront a ,glass ceiling' while men are more likely to benefit from a ,glass escalator'. But what happens when women do achieve leadership roles? And what sorts of positions are they given? This paper argues that while women are now achieving more high profile positions, they are more likely than men to find themselves on a ,glass cliff', such that their positions are risky or precarious. This hypothesis was investigated in an archival study examining the performance of FTSE 100 companies before and after the appointment of a male or female board member. The study revealed that during a period of overall stock-market decline those companies who appointed women to their boards were more likely to have experienced consistently bad performance in the preceding five months than those who appointed men. These results expose an additional, largely invisible, hurdle that women need to overcome in the workplace. Implications for the evaluation of women leaders are discussed and directions for future research are outlined. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||