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Methodological Pitfalls (methodological + pitfall)
Selected AbstractsImpacts of land use change on South-east Asian forest butterflies: a reviewJOURNAL OF APPLIED ECOLOGY, Issue 4 2007LIAN PIN KOH Summary 1South-east Asia has the highest relative rate of habitat loss and degradation in the humid tropics. The responses of less ,charismatic' groups, including butterflies, to habitat disturbance remain relatively poorly understood. Many South-east Asian butterflies are endemic to the region and face global extinction if current levels of deforestation were to continue. 2Here, I highlight South-east Asia as a region urgently in need of butterfly conservation research and review empirical studies of the responses of South-east Asian butterflies to land use change. Additionally, I discuss some methodological pitfalls for such studies. Furthermore, I argue for the importance of identifying the ecological correlates of sensitivity of butterfly species to forest modification and the potential biological mechanisms underlying their responses to land use change. 3There has been no consensus among previous studies on the effects of land use change on butterfly communities in South-east Asia. Of the 20 studies I reviewed, seven reported higher species richness/diversity in undisturbed (or the least disturbed) forest than in disturbed habitats, nine reported the opposite trend, three reported no difference and one reported a strong influence of seasonality on the impacts of logging. 4Some of these studies may contain inherent methodological biases resulting from the failure to control for sampling effects, the lack of consideration for the spatial scale of analysis and incomplete sampling of the vertical strata in tropical rainforests. 5Synthesis and applications. Empirical studies of the effects of land use change on tropical forest insects are sorely lacking from South-east Asia. Butterflies are an ideal taxonomic group for such investigations. Future studies should be designed carefully to avoid the methodological pitfalls highlighted here. Determining the ecological correlates of sensitivity of butterflies to forest modification is important for the pre-emptive identification of species of conservation concern and for generating testable hypotheses on the differential responses of species to forest modification. Experimental studies are needed to determine the mechanisms underlying the responses of species to land use change in order to develop effective strategies for the conservation of butterflies in human disturbed landscapes. [source] Statistical methods in spatial geneticsMOLECULAR ECOLOGY, Issue 23 2009GILLES GUILLOT Abstract The joint analysis of spatial and genetic data is rapidly becoming the norm in population genetics. More and more studies explicitly describe and quantify the spatial organization of genetic variation and try to relate it to underlying ecological processes. As it has become increasingly difficult to keep abreast with the latest methodological developments, we review the statistical toolbox available to analyse population genetic data in a spatially explicit framework. We mostly focus on statistical concepts but also discuss practical aspects of the analytical methods, highlighting not only the potential of various approaches but also methodological pitfalls. [source] Exploiting a Rare Communication Shift to Document the Persuasive Power of the News MediaAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 2 2009Jonathan McDonald Ladd Using panel data and matching techniques, we exploit a rare change in communication flows,the endorsement switch to the Labour Party by several prominent British newspapers before the 1997 United Kingdom general election,to study the persuasive power of the news media. These unusual endorsement switches provide an opportunity to test for news media persuasion while avoiding methodological pitfalls that have plagued previous studies. By comparing readers of newspapers that switched endorsements to similar individuals who did not read these newspapers, we estimate that these papers persuaded a considerable share of their readers to vote for Labour. Depending on the statistical approach, the point estimates vary from about 10% to as high as 25% of readers. These findings provide rare evidence that the news media exert a powerful influence on mass political behavior. [source] A new bipolar spectrum concept: a brief reviewBIPOLAR DISORDERS, Issue 2002Jules Angst Angst J, Gamma A. A new bipolar spectrum concept: a brief review. Bipolar Disord 2002: 4(Suppl. 1): 11,14. © Blackwell Munksgaard, 2002 Research on the broad bipolar spectrum is dependent on the definition of hypomania. We recently proposed a new, softer syndromal definition with clinical validity. This broadens the diagnosis of bipolar II (BP-II) disorder at the expense of major depressive disorder (MDD). There is evidence for a third group of suspected BP-II manifesting major depression plus hypomanic symptoms. The two bipolar-II groups together are as prevalent as MDD. A new concept of minor bipolar disorder embracing dysthymia, minor and recurrent brief depression with hypomanic syndromes and symptoms is discussed. Some methodological pitfalls of research on drug-induced hypomania as an element of the bipolar spectrum are also summarized. [source] | ||||||||||