Home About us Contact
|
Home About us Contact | ||
|
|
||
Main Strategies (main + strategy)
Selected AbstractsEvolutionary ecology of insect adaptation to Bt cropsEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 5-6 2010Yves Carričre Abstract Transgenic crops producing Bacillus thuringiensis (Bt) toxins are used worldwide to control major pests of corn and cotton. Development of strategies to delay the evolution of pest resistance to Bt crops requires an understanding of factors affecting responses to natural selection, which include variation in survival on Bt crops, heritability of resistance, and fitness advantages associated with resistance mutations. The two main strategies adopted for delaying resistance are the refuge and pyramid strategies. Both can reduce heritability of resistance, but pyramids can also delay resistance by reducing genetic variation for resistance. Seasonal declines in the concentration of Bt toxins in transgenic cultivars, however, can increase the heritability of resistance. The fitness advantages associated with resistance mutations can be reduced by agronomic practices, including increasing refuge size, manipulating refuges to increase fitness costs, and manipulating Bt cultivars to reduce fitness of resistant individuals. Manipulating costs and fitness of resistant individuals on transgenic insecticidal crops may be especially important for thwarting evolution of resistance in haplodiploid and parthenogenetic pests. Field-evolved resistance to Bt crops in only five pests during the last 14 years suggests that the refuge strategy has successfully delayed resistance, but the accumulation of resistant pests could accelerate. [source] Approaches to career success: An exploration of surreptitious career-success strategiesHUMAN RESOURCE MANAGEMENT, Issue 1 2006Lloyd C. Harris Theorists have forwarded a vast range of career-success determinants, including sociodemographic, social capital, personality, and other behavioral factors. We suggest that existing studies have overconcentrated on the overt behavioral determinants of career success to the detriment of the covert, clandestine, and concealed. Our analysis of two detailed qualitative case studies involving 112 indepth interviews with executives, managers, supervisors, and front-line staff in a large financial services organization and a medium-sized fashionable restaurant group uncovered five main strategies of surreptitious career success. These strategies are obligation creation and exploitation, personal-status enhancement, information acquisition and control, similarity exploitation, and proactive vertical alignment. Our findings indicate that just over 79% of those interviewed (88 of 112) referred to, at some point in their careers, premeditated strategies to enhance their careers that they concealed from coworkers. Consequently, we argue that surreptitious actions are central to employee career-focused activities and fundamental to a more complete understanding of the complexities of career-oriented employee behavior. © 2006 Wiley Periodicals, Inc. [source] Defining and optimizing algorithms for neighbouring particle identification in SPH fluid simulationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2008G. Viccione Abstract Lagrangian particle methods such as smoothed particle hydrodynamics (SPH) are very demanding in terms of computing time for large domains. Since the numerical integration of the governing equations is only carried out for each particle on a restricted number of neighbouring ones located inside a cut-off radius rc, a substantial part of the computational burden depends on the actual search procedure; it is therefore vital that efficient methods are adopted for such a search. The cut-off radius is indeed much lower than the typical domain's size; hence, the number of neighbouring particles is only a little fraction of the total number. Straightforward determination of which particles are inside the interaction range requires the computation of all pair-wise distances, a procedure whose computational time would be unpractical or totally impossible for large problems. Two main strategies have been developed in the past in order to reduce the unnecessary computation of distances: the first based on dynamically storing each particle's neighbourhood list (Verlet list) and the second based on a framework of fixed cells. The paper presents the results of a numerical sensitivity study on the efficiency of the two procedures as a function of such parameters as the Verlet size and the cell dimensions. An insight is given into the relative computational burden; a discussion of the relative merits of the different approaches is also given and some suggestions are provided on the computational and data structure of the neighbourhood search part of SPH codes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Changes in UK tax-effective giving: implications for donor fundraising strategiesINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 1 2000Gareth G. Morgan Strategies for fundraising from committed donors in the UK have long placed considerable emphasis on tax-efficient giving, in particular the use of deeds of covenant and gift aid which enables charities to recover tax paid by the donor and thus increase the value of a donor's gift. However, recent developments and proposed developments in UK legislation and Inland Revenue procedures are about to make radical changes to this regime. Although in general the changes are beneficial to charities, the precise implications will, in many cases, require a significant change in fundraising strategies to make effective use of the new giving environment. This paper seeks to analyse the nature of those changes and the consequence for fundraising strategies. In relation to three main strategies some approaches to further research are proposed, which a charity may wish to apply in order to assess whether and to what extent new approaches to committed donor fundraising are required. A preliminary version of this paper was presented at the Institute of Charity Fundraising Managers Convention (Academic Stream) in July 1999, but it has been substantially changed to take account of further government announcements made in November, 1999. Copyright © 2000 Henry Stewart Publications [source] How to overcome (and exploit) tumor hypoxia for targeted gene therapyJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2003Olga Greco Tumor hypoxia has long been recognized as a critical issue in oncology. Resistance of hypoxic areas has been shown to affect treatment outcome after radiation, chemotherapy, and surgery in a number of tumor sites. Two main strategies to overcome tumor hypoxia are to increase the delivery of oxygen (or oxygen-mimetic drugs), and exploiting this unique environmental condition of solid tumors for targeted therapy. The first strategy includes hyperbaric oxygen breathing, the administration of carbogen and nicotinamide, and the delivery of chemical radiosensitizers. In contrast, bioreductive drugs and hypoxia-targeted suicide gene therapy aim at activating cytotoxic agents at the tumor site, while sparing normal tissue from damage. The cellular machinery responds to hypoxia by activating the expression of genes involved in angiogenesis, anaerobic metabolism, vascular permeability, and inflammation. In most cases, transcription is initiated by the binding of the transcription factor hypoxia-inducible factor (HIF) to hypoxia responsive elements (HREs). Hypoxia-targeting for gene therapy has been achieved by utilizing promoters containing HREs, to induce selective and efficient transgene activation at the tumor site. Hypoxia-targeted delivery and prodrug activation may add additional levels of selectivity to the treatment. In this article, the latest developments of cancer gene therapy of the hypoxic environment are discussed, with particular attention to combined protocols with ionizing radiation. Ultimately, it is proposed that by adopting specific transgene activation and molecular amplification systems, resistant hypoxic tumor tissues may be effectively targeted with gene therapy. J. Cell. Physiol. 197: 312,325, 2003© 2003 Wiley-Liss, Inc. [source] Repartnering and (Re)employment: Strategies to Cope With the Economic Consequences of Partnership DissolutionJOURNAL OF MARRIAGE AND FAMILY, Issue 5 2009Mieke Jansen The economic consequences of a partnership dissolution have been described consistently in the research literature. For women all studies indicate severe financial losses, whereas men do not experience income decreases to the same extent. This article focuses on the 2 main strategies to cope with the economic consequences of a separation: repartnering and (re)employment. Using the European Community Household Panel Study we analyzed a sample of 66,292 individuals observed in a relationship of whom 4,925 subsequently separated and assessed the (relative) effect of both strategies in a cross-national longitudinal perspective. Where men do not benefit financially from cohabiting with a new partner, repartnering proves to outweigh the benefits of reentering the labor force or increasing the working hours for most women. This especially applies to mothers. [source] Therapeutic management of recurrent hepatitis C after liver transplantationLIVER INTERNATIONAL, Issue 3 2007Rosāngela Teixeira Abstract Recurrent hepatitis C ranges from minimal damage to cirrhosis developing in a few months or years in a substantial proportion of transplant recipients. Different virus, host and donor factors are involved in the pathogenesis of recurrence, but many are poorly understood. Therapeutic strategies can be utilized in the pre-, peri- or posttransplantation setting. Antiviral therapy using interferon and ribavirin and modifying immunosuppression are the main strategies to prevent progression disease. The efficacy of interferon and ribavirin is limited and side effects, reduction/withdrawal are frequent. Current sustained virological response rates are approximately 28%. An optimal immunosupppression regimen has not been established. The choice of calcineurin inhibitors has not clearly been shown to affect histological hepatitis C virus (HCV) but higher cumulative exposure to corticosteroids to treat acute rejection is associated with more severe recurrence. The manner in which the doses of immunosuppression are modified has more influence on HCV recurrence than the use of a specific drug per se. Debate about the influence of immunosuppressive regimens on HCV recurrence is ongoing. Potential antifibrotic therapy and new agents targeting HCV infection and replication are emerging and are anticipated to be added to our armentarium in battling recurrent HCV post-LT. [source] Polyoxometalate/polymer hybrid materials: fabrication and propertiesPOLYMER INTERNATIONAL, Issue 11 2009Wei Qi Abstract In this article we provide an overview of the fabrication and properties of polyoxometalate/polymer hybrid materials. Physical blending, electrostatic adsorption, covalent bonding and supramolecular modification are the main strategies to incorporate polyoxometalates into organic or inorganic (taking silica as an example) polymer matrices. The polyoxometalate/polymer hybrid materials obtained concurrently possess the unique optical, electrical or catalytic properties of polyoxometalates and the favorable processability and stability of polymer matrices. Polyoxometalate/polymer hybrid materials may have potential applications in optics, electronics, biology, medicine and catalysis. Copyright © 2009 Society of Chemical Industry [source] Pathogenesis of catheter-related infections: lessons for new designsCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2002A. Pascual In the last decade, two main strategies have been employed in the prevention of catheter-related infections: the creation of anti-adhesive biomaterials using physicochemical methods, and the incorporation of antimicrobial or antiseptic agents into current polymer biomaterials. There has been limited success with the first approach. Intravascular catheters and cuffs with an antimicrobial coating have been developed in recent years. Nevertheless, preventive strategies should avoid the use of therapeutic antibiotics. Exposure to antimicrobial agents could favor the development of resistance or the expression of genes responsible for biofilm formation. The use of these catheters should be restricted to situations where the rate of infection is high despite adherence to other strategies that do not incorporate antimicrobial agents. Better knowledge of the pathogenesis of catheter-related infections will facilitate the design of new devices that avoid the use of antimicrobial agents and decrease the risk of associated bloodstream infections. This could include the use of ,biospecific polymers' coated with anti-adhesive molecules or the use of agents which might block the expression of genes controlling biofilm formation for the most prevalent pathogens. [source] Advancing Entertainment Education: Using The Rosie O'Donnell Show to Recognize Implementation Strategies for Saturated MarketsCOMMUNICATION THEORY, Issue 2 2009Deborah L. Larson Entertainment-education (E-E) has been widely and successfully implemented in developing countries around the world, but it is much harder to utilize in media-saturated countries. However, talk shows can be a niche market for E-E campaigns. As evidence, The Rosie O'Donnell Show has made a significant contribution to the television industry and to entertainment-education research by redefining how advocacy, education, and entertainment can work through a variety talk show format. An extemporaneous talk show can implement E-E campaigns through four main strategies to target its viewers: (1) Variability, or using a variety of forms to provide campaign information, (2) using multimediated synergistic avenues and online connections, (3) creating audience proactivity by using a small group elements to promote self and collective efficacy, and host appeal to bridge the local to national gap, and (4) the host's use of instinctive intentionality in aggregating campaign messages. As executive producer and host of her show, Rosie O'Donnell affected awareness, disseminated educational information, and encouraged proactive behavior with social, political, and philanthropic agendas through repetitive, positive, and proactive entertainment-education messages. [source] Cognitive enhancement as a pharmacotherapy target for stimulant addictionADDICTION, Issue 1 2010Mehmet Sofuoglu ABSTRACT Background No medications have been proven to be effective for cocaine and methamphetamine addiction. Attenuation of drug reward has been the main strategy for medications development, but this approach has not led to effective treatments. Thus, there is a need to identify novel treatment targets in addition to the brain reward system. Aim To propose a novel treatment strategy for stimulant addiction that will focus on medications enhancing cognitive function and attenuating drug reward. Methods Pre-clinical and clinical literature on potential use of cognitive enhancers for stimulant addiction pharmacotherapy was reviewed. Results and conclusions Cocaine and methamphetamine users show significant cognitive impairments, especially in attention, working memory and response inhibition functions. The cognitive impairments seem to be predictive of poor treatment retention and outcome. Medications targeting acetylcholine and norepinephrine are particularly well suited for enhancing cognitive function in stimulant users. Many cholinergic and noradrenergic medications are on the market and have a good safety profile and low abuse potential. These include galantamine, donepezil and rivastigmine (cholinesterase inhibitors), varenicline (partial nicotine agonist), guanfacine (alpha2 -adrenergic agonist) and atomoxetine (norepinephrine transporter inhibitor). Future clinical studies designed optimally to measure cognitive function as well as drug use behavior would be needed to test the efficacy of these cognitive enhancers for stimulant addiction. [source] Breast cancer survival in England, Norway and Sweden: a population-based comparison,INTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Henrik Mųller Abstract Several international studies have found that survival from breast cancer is lower in the United Kingdom than in some other European countries. We have compared breast cancer survival between the national populations of England, Norway and Sweden, with a view to identifying subsets of patients with particularly good or adverse survival outcomes. We extracted cases of breast cancer in women diagnosed 1996,2004 from the national cancer registries of the 3 countries. The study comprised 303,657 English cases, 24,919 Norwegian cases and 57,512 cases from Sweden. Follow-up was in 2001,2004. The main outcome measures were 5-year cumulative relative survival and excess death rates, stratified by age and period of follow-up. In comparison with Norway and Sweden, the excess mortality in England was particularly pronounced in the first month and in the first year after diagnosis, and generally more marked in the oldest age groups. Compared with Norwegian patients, 81% of the excess deaths in the English patients occurred in the first 2 years after diagnosis. Our findings emphasise the importance of awareness of symptoms and early detection as the main strategy to improve breast cancer survival in the United Kingdom. [source] | ||||||||||||||||