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Actual Role (actual + role)
Selected AbstractsPayments for Ecosystem Services in Nicaragua: Do Market-based Approaches Work?DEVELOPMENT AND CHANGE, Issue 3 2010Gert Van Hecken ABSTRACT The concept of Payments for Ecosystem Services (PES) is gaining increasing attention among scholars as well as conservation and development practitioners. The premises of this innovative conservation approach are appealing: private land users, usually poorly motivated to protect nature on their land, will do so if they receive payments from environmental service buyers which cover part of the land users' opportunity costs of developing the land. However, this article warns against an over-enthusiastic adoption of a one-sided market-based PES approach. Based on a field study of the Regional Integrated Silvopastoral Approaches to Ecosystem Management Project (RISEMP), one of the main PES pilot projects in Nicaragua, it suggests that a mixture of economic and non-economic factors motivated farmers to adopt the envisaged silvopastoral practices and that the actual role of PES is mistakenly understood as a simple matter of financial incentives. The authors argue that PES approaches should be understood as a part of a broader process of local institutional transformation rather than as a market-based alternative for allegedly ineffective government and/or community governance. [source] Synergistic impacts of malathion and predatory stress on six species of North American tadpolesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2004Rick A. Relyea Abstract The decline of many amphibian populations is associated with pesticides, but for most pesticides we know little about their toxicity to amphibians. Malathion is a classic example; it is sprayed over aquatic habitats to control mosquitoes that carry malaria and the West Nile virus, yet we know little about its effect on amphibians. I examined the survival of six species of tadpoles (wood frogs, Rana sylvatica; leopard frogs, R. pipiens; green frogs, R. clamitans; bullfrogs, R. catesbeiana; American toads, Bufo americanus; and gray tree frogs, Hyla versicolor) for 16 d in the presence or absence of predatory stress and six concentrations of malathion. Malathion was moderately toxic to all species of tadpoles (median lethal concentration [LC50] values, the concentration estimated to kill 50% of a test population, ranged from 1.25,5.9 mg/L). These values are within the range of values reported for the few amphibians that have been tested (0.2,42 mg/L). In one of the six species, malathion became twice as lethal when combined with predatory stress. Similar synergistic interactions have been found with the insecticide carbaryl, suggesting that the synergy may occur in many carbamate and organophosphate insecticides. While malathion has the potential to kill amphibians and its presence is correlated with habitats containing declining populations, its actual role in amphibian declines is uncertain given the relatively low concentration in aquatic habitats. [source] Adoptive transfer of an anti-MART-127,35 -specific CD8+ T,cell clone leads to immunoselection of human melanoma antigen-loss variants in SCID miceEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2003Francesco Lozupone Abstract The identification of appropriate mouse models could be useful in carefully evaluating the actual role of the in vivo development of antigen-loss variants during antigen-specific vaccine therapy of human tumors. In this study we investigated the level of efficacy of a MART-1/Melan-A-specific CD8+ T,cell clone against its autologous melanoma in a severe combined immunodeficiency (SCID) mouse model, in which the tumor cells expressed in vivo heterogeneous and suboptimal levels of MART-1. The subcutaneous co-injection of the MART-1/Melan-A-reactive T,cell clone A42 with MART-1/Melan-A+ autologous human melanoma cells into SCID mice caused a total inhibition of tumor growth. However, the systemic treatment with A42 clone lymphocytes resulted inonly 50,60% inhibition of tumor growth, although the T,cell clone targeted the tumors and the MART-1+ cells virtually disappeared from the tumors. This study suggests that an immunotherapybased on the expansion of an antigen-specific T,cell clone generated in vitro is highly efficient in abolishing tumor growth when the target antigen is fully expressed, but leads to in vivoimmunoselection of antigen-loss variants in the presence of suboptimal levels of antigen expression. Furthermore, this work shows that human tumors/SCID mouse models may be useful in evaluating thein vivo efficacy of adoptive immunotherapies. [source] Accounting, Modernity and Health Care PolicyFINANCIAL ACCOUNTABILITY & MANAGEMENT, Issue 4 2001Irvine Lapsley The National Health Service of the United Kingdom has been the subject of many reforms since it was established in 1948. This paper examines the process of reform in relation to significant changes to the NHS in recent decades. This reform process places ideas of the modern at the heart of these various initiatives. This paper also examines the intended or actual role of accounting in this modernisation process to examine its significance in the making of health care policy. [source] Recurrent coamplification of cytoskeleton-associated genes EMS1 and SHANK2 with CCND1 in oral squamous cell carcinomaGENES, CHROMOSOMES AND CANCER, Issue 2 2006Kolja Freier Chromosomal band 11q13 is frequently amplified in oral squamous cell carcinoma (OSCC) and assumed to be critically involved in tumor initiation and progression by proto-oncogene activation. Though cyclin D1 (CCND1) is supposed to be the most relevant oncogene, several additional putative candidate genes are inside this chromosomal region, for which their actual role in tumorigenesis still needs to be elucidated. To characterize the 11q13 amplicon in detail, 40 OSCCs were analyzed by comparative genomic hybridization to DNA microarrays (matrix-CGH) containing BAC clones derived from chromosomal band 11q13. This high-resolution approach revealed a consistent amplicon about 1.7 Mb in size including the CCND1 oncogene. Seven BAC clones covering FGF3, EMS1, and SHANK2 were shown to be frequently coamplified inside the CCND1 amplicon. Subsequent analysis of tissue microarrays by FISH revealed amplification frequencies of 36.8% (88/239) for CCND1, 34.3% (60/175) for FGF3, 37.4% (68/182) for EMS1, and 36.3% (61/168) for SHANK2. Finally, quantitative mRNA expression analysis demonstrated consistent overexpression of CCND1 in all tumors and of EMS1 and SHANK2 in a subset of specimens with 11q13 amplification, but no expression of FGF3 in any of the cases. Our study underlines the critical role of CCND1 in OSCC development and additionally points to the functionally related genes EMS1 and SHANK2, both encoding for cytoskeleton-associated proteins, which are frequently coamplified with CCND1 and therefore could cooperatively contribute to OSCC pathogenesis. © 2005 Wiley-Liss, Inc. [source] Threshold Voltage Shifts in Organic Thin-Film Transistors Due to Self-Assembled Monolayers at the Dielectric SurfaceADVANCED FUNCTIONAL MATERIALS, Issue 6 2009Stefan K. Possanner Abstract Recently, it has been shown by several groups that the electrical characteristics of organic thin-film transistors (OTFTs) can be significantly influenced by depositing self-assembled monolayers (SAMs) at the organic semiconductor/dielectric interface. In this work, the effect of such SAMs on the transfer characteristics and especially on the threshold voltage of OTFTs is investigated by means of two-dimensional drift-diffusion simulations. The impact of the SAM is modeled either by a permanent space charge layer that can result from chemical reactions with the active material, or by a dipole layer representing an array of ordered dipolar molecules. It is demonstrated that, in both model cases, the presence of the SAM significantly changes the transfer characteristics. In particular, it gives rise to a modified, effective gate voltage Veff that results in a rigid shift of the threshold voltage, ,Vth, relative to a SAM-free OTFT. The achievable amount of threshold voltage shift, however, strongly depends on the actual role of the SAM. While for the investigated device dimensions, an organic SAM acting as a dipole layer can realistically shift the threshold voltage only by a few volts, the changes in the threshold voltage can be more than an order of magnitude larger when the SAM leads to charges at the interface. Based on the analysis of the different cases, a route to experimentally discriminate between SAM-induced space charges and interface dipoles is proposed. The developed model allows for qualitative description of the behavior of organic transistors containing reactive interfacial layers; when incorporating rechargeable carrier trap states and a carrier density-dependent mobility, even a quantitative agreement between theory and recent experiments can be achieved. [source] Etiopathogenic role of HLA-B27 alleles in ankylosing spondylitisINTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 3 2005Nurullah AKKOC Abstract HLA-B27 is the major genetic susceptibility factor for ankylosing spondylitis (AS). However, its precise role in the pathogenesis of AS still remains unclear, even though its gene has been cloned and sequenced, and its crystallographic structure has been defined. Arthritogenic peptide and molecular mimicry hypotheses propose mechanisms related to an antigen-presenting function of HLA-B27 to be responsible for disease development. However, peculiar aspects of its immunobiology, such as its misfolding and heavy chain dimerization raise the possibility of involvement of pathogenic mechanisms unrelated to its physiological function. Moreover, HLA-B27 is not a single allele, but a family of 31 different alleles, named HLA-B*2701 to HLA-B*2727. Studies worldwide indicate that the relatively common alleles (subtypes) HLA-B*2705, B*2704, and B*2702 are strongly associated with AS, whereas HLA-B*2706 which is prevalent in South-east Asia and HLA-B*2709 which is prevalent on the Italian island of Sardinia, seem to lack such an association. The distinction between the disease-associated subtypes and those that are not associated, may provide clues to the actual role of HLA-B27 in disease pathogenesis. B*2706 differs from B*2704 by only two residues, and B*2709 differs from B*2705 by only one residue. Moreover, both B*2706 and B*2709 bind an endogenous peptide (derived from vasoactive intestinal peptide type 1 receptor) and also an exogenous peptide (latent membrane protein 2 of Epstein-Barr virus) but in two drastically diverse conformations. These recent X-ray diffraction studies of individual peptides in the context of different HLA-B27 alleles broaden our perception of the possible pathogenetic role of this molecule in the development of AS and related spondyloarthopathies. In summary, the pathogenetic role of HLA-B27 in AS seem to be quite heterogenous, and cannot be explained by a single mechanism, and new ideas have been raised based on the aberrant immunobiologic features of HLA-B27. [source] Purification, crystallization and preliminary data analysis of FocB, a transcription factor regulating fimbrial adhesin expression in uropathogenic Escherichia coliACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Ulrika W. Hultdin The transcription factor FocB belongs to a family of regulators encoded by several different fimbriae gene clusters in uropathogenic Escherichia coli. Recent findings suggest that FocB-family proteins may form different protein,protein complexes and that they may exert both positive and negative effects on the transcription of fimbriae genes. However, little is known about the actual role and mode of action when these proteins interact with the fimbriae operons. The 109-amino-acid FocB transcription factor from the foc gene cluster in E. coli strain J96 has been cloned, expressed and purified. The His6 -tagged fusion protein was captured by Ni2+ -affinity chromatography, cleaved with tobacco etch virus protease and purified by gel filtration. The purified protein is oligomeric, most likely in the form of dimers. NMR analysis guided the crystallization attempts by showing that probable conformational exchange or oligomerization is reduced at temperatures above 293,K and that removal of the highly flexible His6 tag is advantageous. The protein was crystallized using the hanging-drop vapour-diffusion method at 295,K. A native data set to 2.0,Å resolution was collected at 100,K using synchrotron radiation. [source] Best practices in board governance: Evidence from South CarolinaNONPROFIT MANAGEMENT & LEADERSHIP, Issue 2 2008Jo An M. Zimmermann In June 2003, a large-scale survey was conducted among South Carolina nonprofit agencies to gather information on a range of board governance issues. Some of the survey questions dealt with how each agency's board contributes to the organization. More than 80 percent of the responding agencies were registered as 501(c)(3), with the largest number of respondents in the human services category. Statistical analysis reveals where actual roles differ from "best practices" as prescribed in the literature. Discussion then focuses on how these trends in governance affect management and operations. In particular, we look at best practice regarding the separation of board and staff duties. [source] Empowering salespeople: Personal, managerial, and organizational perspectivesPSYCHOLOGY & MARKETING, Issue 2 2006Rolph E. Anderson The traditional seven steps of personal selling have remained virtually unchanged since the early 1900s. Meanwhile, the actual roles and duties of salespeople have pushed far into customer relationship management (CRM). Psychologically and professionally, salespeople need greater empowerment for their expanding CRM responsibilities. However, empowerment is a complex process requiring several individual, managerial, and organizational changes for successful implementation. As part of the empowerment process for its salespeople, companies need to provide supporting structures, processes, and incentives for customer-oriented behavior. At the same time, the Internet and other telecommunications advances in the macroenvironment are accelerating empowerment changes in personal selling,mainly on the customer side of the exchange. To effectively and efficiently carry out their growing yet still poorly defined CRM roles, salespeople need to be comprehensively empowered, trained, motivated, and rewarded. Companies that most effectively empower their salespeople should reap substantial rewards in profitability and loyalty from both their salespeople and customers. © 2006 Wiley Periodicals, Inc. [source] | |||||||||||||