9,482 research outputs found
Long-run marketing inferences from scanner data.
Good marketing decisions require managers' understanding of the nature of the market-response function relating performance measures such as sales and market share to variations in the marketing mix (product, price, distribution and communications efforts). Our paper focuses on the dynamic aspect of market-response functions, i.e. how current marketing actions affect current and future market response. While conventional econometrics has been the dominant methodology in empirical market-response analyses, time-series analysis offers unique opportunities for pushing the frontier in dynamic research. This paper examines the contributions an d the future outlook of time-series analysis in market-response modeling. We conclude first, that time series analysis has made a relatively limited overall contribution to the discipline, and investigate reasons why that has been the case. However, major advances in data (transactions-based databases and in modeling technology (long-term time-series modeling) create new opportunities for time-series techniques in marketing, in particular for the study of long-run marketing effectiveness. We discuss four major aspects of long -term time-series modeling, relate them to substantive marketing problems, and describe some early applications. Combining the new data with the new methods, we then present original empirical results on the long-term behavior of brand sales and category sales for four consumer products. We discuss the implications of our findings for future research in market response. Our observations lead us to identify three areas where additional research could enhance the diffusion of the identified time-series concepts in marketing.Data; Marketing;
Contexts for questioning: Two zones of teaching and learning in undergraduate science
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer Science+Business Media B.V. 2012.Higher education institutions are currently undertaking a challenging process in moving from teacher-orientated to student-focused approaches. Studentsâ ability to asking questions is fundamental to developing critical reasoning, and to the process of scientific enquiry itself. Our premise is that questioning competences should become a central focus of current reforms in higher education. This study, part of a broader naturalistic research project, aims at developing a theoretical framework for conceptualizing different contexts for questioning, illustrating the application of the proposed framework (contextual questioning zones) and reflecting about some of the dimensions of teaching and learning, for overcoming some of the challenges that higher education institutions are facing presently. The discussion of two âoppositeâ contexts of enquiry is based on qualitative data, gathered through close collaboration with four teachers of undergraduate biology at a Portuguese university. These teachers were observed during their âdaily activityâ during an academic year. Data was also gathered by interviewing these teachers and 8 selected students, at the end of the year, and used to sustain the argumentation. The paper concludes with some reflections and suggestions to promote authentic enquiry-based learning experiences.Portuguese FundaçaÌo para a CiĂȘncia e a Tecnologi
Recommended from our members
The old questions are the best: striving against invalidity in qualitative research
This chapter enters an old debate on the shape of validation processes in qualitative research. We discuss a reflective research validation framework related to teaching approaches and practices. The majority of investigations in this area draw mainly on indirect observation, semistructured interviews or the application of questionnaires and inventories. To this extent, only âhalf-the-storyâ has been reported. The validation framework here develops a five-part three stage structure, conceptualized as an âiterative-interactive-process,â integrating a set of strategies aimed at the âminimization of invalidity.â The application of the framework is illustrated through a longitudinal study investigating the relationship between classroom questioning practices and teachersâ preferential teaching approaches. Fieldwork in this naturalistic-interpretative research was conducted during four academic years and entailed close collaboration with a group of four university teachers lecturing biology to undergraduates.The authors acknowledge the financial support of Portuguese FundacžaËo para a CieËncia e a Tecnologia (SFRH/BD/44611/2008; PTDC/CPE-CED/ 117516/2010).Portuguese Fundac ̧ a Ì o para a CieË ncia e a Tecnologia (SFRH/BD/44611/2008; PTDC/CPE-CED/ 117516/2010)
Murine infection with bioluminescent Leishmania infantum axenic amastigotes applied to drug discovery
Leishmaniasis is an important vector-borne neglected tropical disease caused by Leishmania parasites. Current anti-Leishmania chemotherapy is unsatisfactory, justifying the continued search for alternative treatment options. Herein, we demonstrate that luciferase-expressing Leishmania infantum axenic amastigotes, unlike promastigotes, are highly infectious to BALB/c mice and thus generate a robust bioluminescent signal in target organs, such as the liver and the spleen, as early as two weeks after infection. Treatment with the reference drugs amphotericin B and miltefosine was effective at reducing parasite burdens. This model allows the assessment of treatment efficacy using whole-mouse bioluminescence imaging without the need to wait several weeks for spleen infections to be detectable by this non-invasive method. In conclusion, we propose the use of this model in an initial approach to evaluate the treatment efficacy of promising chemical entities without having to sacrifice large numbers of animals or to wait several days for a readout.We thank Carla Oliveira from i3S for the support with the statistical analysis. Part of the content of this manuscript has been released as a pre-print in BioRxiv (https://doi.org/10.1101/326355). This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a CiĂȘncia e a Tecnologia/MinistĂ©rio da CiĂȘncia, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-031013 (PTDC/SAU-PAR/31013/2017). This work also received funds from: Norte-01-0145-FEDER-000012 âStructured program on bioengineered therapies for infectious diseases and tissue regenerationâ of Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) and through the Research Unit No. 4293; Individual funding from FCT through SFRH/BD/123734/2016 (to DC), SFRH/BD/121252/2016 (to PC) and CEECIND/02362/2017 (to JT)
Invasion strategies of the white ginger lily Hedychium coronarium J. Konig (Zingiberaceae) under different competitive and environmental conditions
The role of evolutive elastic properties in the performance of a sheet formed spring applied in multimedia car industry
The manufacturing process and the behavior of a sheet formed spring manufactured from an aluminum sheet is described and investigated in this work considering the specifications for the in-service conditions. The sheet formed spring is intended to be applied in car multimedia industry to replace bolted connections. Among others, are investigated the roles of the constitutive parameters and the hypothesis of evolutive elastic properties with the plastic work in the multi-step forming process and in working conditions.This research was sponsored by:a) Portugal Incentive System for Research and Technological Development. Project in co-promotion no 36265/2013 (Project HMIExcel - 2013-2015), andb) FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 - Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio
Mutation (G275E) of the nicotinic acetylcholine receptor α6 subunit is associated with high levels of resistance to spinosyns in Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).
PublishedJournal ArticleThe tomato leafminer, Tuta absoluta, now a major pest of tomato crops worldwide, is primarily controlled using chemical insecticides. Recently, high levels of resistance to the insecticide spinosad have been described in T. absoluta populations in Brazil. Selection of a resistant field-collected strain led to very high levels of resistance to spinosad and cross-resistance to spinetoram, but not to other insecticides that target the nicotinic acetylcholine receptor (nAChR). In this study the mechanisms underlying resistance to spinosad were investigated using toxicological, biochemical and molecular approaches. Inhibition of metabolic enzymes using synergists and biochemical assessment of detoxification enzyme activity provided little evidence of metabolic resistance in the selected strain. Cloning and sequencing of the nAChR α6 subunit from T. absoluta, the spinosad target-site, from susceptible and spinosad-resistant strains were done to investigate the role of a target-site mechanism in resistance. A single nucleotide change was identified in exon 9 of the α6 subunit of the resistant strain, resulting in the replacement of the glycine (G) residue at position 275 observed in susceptible T. absoluta strains with a glutamic acid (E). A high-throughput DNA-based diagnostic assay was developed and used to assess the prevalence of the G275E mutation in 17 field populations collected from different geographical regions of Brazil. The resistant allele was found at low frequency, and in the heterozygous form, in seven of these populations but at much higher frequency and in the homozygous form in a population collected in the Iraquara municipality. The frequency of the mutation was significantly correlated with the mortality of these populations in discriminating dose bioassays. In summary our results provide evidence that the G275E mutation is an important mechanism of resistance to spinosyns in T. absoluta, and may be used as a marker for resistance monitoring in field populations.Thanks to CAPES for the scholarship granted to the first author and to Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico â CNPq for the financial support to the project (Universal 484240/2011-0, H.A.A.S.). The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union Seventh Framework Programme FP7/2007-2013/ under REA grant agreement PIRSES-GA-2012 â 318246. This work was in part funded by a fellowship grant (BB/G023352/1) from the Biotechnology and Biological Sciences Research Council of the UK to Dr. Chris Bass and a PhD studentship award from the BBSRC which funded Madeleine Berger
- âŠ