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Challenges Specific (challenge + specific)
Selected AbstractsImpact of the Rapid Rise of Supermarkets on Dairy Products Systems in ArgentinaDEVELOPMENT POLICY REVIEW, Issue 4 2002Graciela E. Gutman The reconfiguration and consolidation of food retailing in Argentina during the 1990s profoundly changed the marketing system for food and agricultural products. The new commercial requirements and ,rules of the game' imposed by supermarkets on their suppliers have caused a substantial restructuring of supply chains , a process in which some suppliers fail. This article describes the changes in the past decade in the Argentine retail sector, and then focuses on the effects of those changes (and related changes in processing) on milk products supply chains. Its conclusions focus on the challenges specific to small farms and firms in the face of this transformation. [source] Communicating with Subjects: Special Challenges for Resuscitation ResearchACADEMIC EMERGENCY MEDICINE, Issue 11 2005Ilene Wilets PhD Abstract In May 2005, Academic Emergency Medicine sponsored a one-day consensus conference held in association with the 2005 Society for Academic Emergency Medicine meeting in New York City. The conference, entitled "Ethical Conduct of Resuscitation Research," addressed a variety of issues regarding the successful conduct of research in acute care settings. A number of important breakout sessions were convened based on challenges specific to resuscitation research. "Communicating with Subjects" was one such session, dedicated toward perfecting the conduct of informed consent for research. The breakout session was attended by 15 insightful emergency medicine investigators, administrators, and ethicists. Issues of research information disclosure, subject comprehension, and the voluntariness of research participation were addressed. Consensus statements were developed and are discussed within this report. [source] THE ECONOMICS OF THE UNCOVERED INTEREST PARITY CONDITION FOR EMERGING MARKETSJOURNAL OF ECONOMIC SURVEYS, Issue 1 2009C. Emre Alper Abstract Financial account liberalizations since the second half of the 1980s paved the way for the burgeoning literature that investigates foreign exchange market efficiency in emerging markets (EMs) via testing for the uncovered interest parity (UIP) condition. This paper is the first to provide a broad and critical survey on this recent literature. Specifically, we attempt to answer the following questions. First, are the EMs different from the developed economies in the context of the UIP condition? Second, to what extent can these differences contribute to the debate on the UIP literature? Third, what are the empirical challenges specific to the EMs in testing for the UIP condition? [source] The burgeoning field of statistical phylogeographyJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2004L. L. Knowles Abstract In the newly emerging field of statistical phylogeography, consideration of the stochastic nature of genetic processes and explicit reference to theoretical expectations under various models has dramatically transformed how historical processes are studied. Rather than being restricted to ad hoc explanations for observed patterns of genetic variation, assessments about the underlying evolutionary processes are now based on statistical tests of various hypotheses, as well as estimates of the parameters specified by the models. A wide range of demographical and biogeographical processes can be accommodated by these new analytical approaches, providing biologically more realistic models. Because of these advances, statistical phylogeography can provide unprecedented insights about a species' history, including decisive information about the factors that shape patterns of genetic variation, species distributions, and speciation. However, to improve our understanding of such processes, a critical examination and appreciation of the inherent difficulties of historical inference and challenges specific to testing phylogeographical hypotheses are essential. As the field of statistical phylogeography continues to take shape many difficulties have been resolved. Nonetheless, careful attention to the complexities of testing historical hypotheses and further theoretical developments are essential to improving the accuracy of our conclusions about a species' history. [source] A review of acoustic playback techniques for studying avian vocal duetsJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2010Sarah B. Douglas ABSTRACT Playback experiments involve the broadcast of natural or synthetic sound stimuli and provide a powerful tool for studying acoustic communication in birds. Playback is a valuable technique for exploring vocal duetting behavior because it allows investigators to test predictions of the various hypotheses for duet function. Here, we adopt a methodological perspective by considering various challenges specific to studying duetting behavior, and highlighting the utility of different playback designs for testing duet function. Single-speaker playback experiments allow investigators to determine how duetting birds react to different stimuli, but do not simulate duets in a spatially realistic manner. Multi-speaker playback experiments are superior to single-speaker designs because duet stimuli are broadcast with spatial realism and unique and additional predictions can be generated for testing duet function. In particular, multi-speaker playback allows investigators to evaluate how birds respond to male versus female duet contributions separately, based on reactions to the different loudspeakers. Interactive playback allows investigators to ask questions about the time- and pattern-specific singing behavior of birds, and to understand how singing strategies correspond to physical behavior during vocal interactions. Although logistically challenging, interactive playback provides a powerful tool for examining specific elements of duets (such as the degree of coordination) and may permit greater insight into their functions from an operational perspective. Interactive playback designs where the investigator simulates half of a duet may be used to describe and investigate the function of pair-specific and population-wide duet codes. Regardless of experimental design, all playback experiments should be based on a sound understanding of the natural duetting behavior of the species of interest, and should aim to produce realistic and carefully controlled duet simulations. Future studies that couple playback techniques with other experimental procedures, such as Acoustic Location System recordings for monitoring the position of birds in dense vegetation or multimodal techniques that combine acoustic with visual stimuli, are expected to provide an even better understanding of these highly complex vocal displays. RESUMEN Los experimentos de reproducción de sonidos grabados involucran el uso de sonido natural o sintético y proveen una herramienta poderosa para el estudio de la comunicación acústica de las aves. La reproducción de sonidos grabados es una técnica valiosa para explorar las duetas vocales porque permite probar las predicciones de varios hipótesis sobre la función de duetas. Aquí, adoptamos una perspectiva metodológica, considerando los varios retos específicos al estudio del comportamiento de duetas y resaltando la utilidad de diferentes diseños de reproducción de sonidos grabados para probar la función de las duetas. Experimentos de reproducción de sonidos grabados hechas con un parlante permiten una determinación de como las aves que realizan duetas reaccionan a diferentes estímulos, pero no simulan las duetas de una manera espacialmente realística. Experimentos de reproducción de sonidos grabados hechas con múltiples parlantes son superiores a diseños con un solo parlante porque transmiten el sonido de una manera espacialmente realística y generan predicciones únicas y adicionales para probar la función de la dueta. En particular, la reproducción de sonidos grabados con múltiples parlantes permite una evaluación de cómo las aves responden a las contribuciones del macho y de la hembra separadamente, basado en sus reacciones a los diferentes parlantes. La reproducción de sonidos grabados interactiva permite hacer preguntas temporalmente especificas y en relación a patrones especificas sobre el comportamiento de canto. También permite entender como las estrategias de canto corresponden al comportamiento físico durante las interacciones vocales. Aunque es un reto logístico, la reproducción de sonidos grabados interactiva provee una herramienta poderosa para examinar elementos específicos de las duetas (como el grado de coordinación) y podría permitir un mayor conocimiento sobre sus funciones de una perspectiva operacional. Los diseños de la reproducción de sonidos grabados interactivas, en la cual el investigador simula la mitad de una dueta, podrían ser usadas para describir e investigar la función de los códigos de dueta específicos a una pareja y a una población. Sin importar el tipo de diseño experimental, todos los experimentos de reproducción de sonidos grabados deberían ser basadas en una buena comprensión del comportamiento natural de las duetas en la especie de interés, y deberían tener la meta de producir simulaciones de duetas realísticas y cuidadosamente controladas. Se espera que los estudios futuros cuales combinan técnicas de la reproducción de sonidos grabados con otros procedimientos experimentales, como grabaciones del Sistema de Ubicación Acústica para monitorear la posición de aves en vegetación densa, o técnicas multimodales que combinan estímulos acústicos con estímulos visuales, provean un mejor entendimiento de estos despliegues vocales altamente complejos. [source] | ||||||||||