Conceptual Bridge (conceptual + bridge)

Distribution by Scientific Domains


Selected Abstracts


Patterns and causes of species richness: a general simulation model for macroecology

ECOLOGY LETTERS, Issue 9 2009
Nicholas J. Gotelli
Abstract Understanding the causes of spatial variation in species richness is a major research focus of biogeography and macroecology. Gridded environmental data and species richness maps have been used in increasingly sophisticated curve-fitting analyses, but these methods have not brought us much closer to a mechanistic understanding of the patterns. During the past two decades, macroecologists have successfully addressed technical problems posed by spatial autocorrelation, intercorrelation of predictor variables and non-linearity. However, curve-fitting approaches are problematic because most theoretical models in macroecology do not make quantitative predictions, and they do not incorporate interactions among multiple forces. As an alternative, we propose a mechanistic modelling approach. We describe computer simulation models of the stochastic origin, spread, and extinction of species' geographical ranges in an environmentally heterogeneous, gridded domain and describe progress to date regarding their implementation. The output from such a general simulation model (GSM) would, at a minimum, consist of the simulated distribution of species ranges on a map, yielding the predicted number of species in each grid cell of the domain. In contrast to curve-fitting analysis, simulation modelling explicitly incorporates the processes believed to be affecting the geographical ranges of species and generates a number of quantitative predictions that can be compared to empirical patterns. We describe three of the ,control knobs' for a GSM that specify simple rules for dispersal, evolutionary origins and environmental gradients. Binary combinations of different knob settings correspond to eight distinct simulation models, five of which are already represented in the literature of macroecology. The output from such a GSM will include the predicted species richness per grid cell, the range size frequency distribution, the simulated phylogeny and simulated geographical ranges of the component species, all of which can be compared to empirical patterns. Challenges to the development of the GSM include the measurement of goodness of fit (GOF) between observed data and model predictions, as well as the estimation, optimization and interpretation of the model parameters. The simulation approach offers new insights into the origin and maintenance of species richness patterns, and may provide a common framework for investigating the effects of contemporary climate, evolutionary history and geometric constraints on global biodiversity gradients. With further development, the GSM has the potential to provide a conceptual bridge between macroecology and historical biogeography. [source]


Are Humanitarian Military Interventions Obligatory?

JOURNAL OF APPLIED PHILOSOPHY, Issue 2 2008
JOVANA DAVIDOVIC
abstract I argue here that certain species of war, namely humanitarian military interventions (HMIs), can be obligatory within particular contexts. Specifically, I look at the notion of HMIs through the lens of just war theory and argue that when a minimal account of jus ad bellum implies that an intervention is permissible, it also implies that it is obligatory. I begin by clarifying the jus ad bellum conditions (such as just cause, right intentions, etc.) under which an intervention is permissible. I then turn to the claim that permissibility necessitates obligation, by first showing that whenever an intervention is permissible, it is also minimally decent. Second, I show that minimally decent actions are morally obligatory by arguing that the notion of minimal decency is a conceptual bridge between negative and positive duties. Third, I argue that performing minimally decent actions is necessary for a state to be just. Ultimately, my conclusion arises from the following observation: if a humanitarian crisis is bad enough for one to hold that it is permissible to breach sovereignty of a nation, then it is bad enough to hold that there is an obligation to intervene. [source]


The essential role of social theory in qualitative public health research

AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 5 2007
Karen Willis
Abstract Objective: To define the role of social theory and examine how research studies using qualitative methods can use social theory to generalise their results beyond the setting of the study or to other social groups. Approach: The assumptions underlying public health research using qualitative methods derive from a range of social theories that include conflict theory, structural functionalism, symbolic interactionism, the sociology of knowledge and feminism. Depending on the research problem, these and other social theories provide conceptual tools and models for constructing a suitable research framework, and for collecting and analysing data. In combination with the substantive health literature, the theoretical literature provides the conceptual bridge that links the conclusions of the study to other social groups and settings. Conclusion: While descriptive studies using qualitative research methods can generate important insights into social experience, the use of social theory in the construction and conduct of research enables researchers to extrapolate their findings to settings and groups broader than the ones in which the research was conducted. [source]


Phylogeography: retrospect and prospect

JOURNAL OF BIOGEOGRAPHY, Issue 1 2009
John C. Avise
Abstract Phylogeography has grown explosively in the two decades since the word was coined and the discipline was outlined in 1987. Here I summarize the many achievements and novel perspectives that phylogeography has brought to population genetics, phylogenetic biology and biogeography. I also address future directions for the field. From the introduction of mitochondrial DNA assays in the late 1970s, to the key distinction between gene trees and species phylogenies, to the ongoing era of multi-locus coalescent theory, phylogeographic perspectives have consistently challenged conventional genetic and evolutionary paradigms, and they have forged empirical and conceptual bridges between the formerly separate disciplines of population genetics (microevolutionary analysis) and phylogenetic biology (in macroevolution). [source]


What is conceptual research in psychoanalysis?,

THE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS, Issue 5 2006
Research Subcommittee for Conceptual Research of the International Psychoanalytical Association
The development of psychoanalysis as a science and clinical practice has always relied heavily on various forms of conceptual research. Thus, conceptual research has clarifi ed, formulated and reformulated psychoanalytic concepts permitting to better shape the fi ndings emerging in the clinical setting. By enhancing clarity and explicitness in concept usage it has facilitated the integration of existing psychoanalytic thinking as well as the development of new ways of looking at clinical and extraclinical data. Moreover, it has offered conceptual bridges to neighbouring disciplines particularly interested in psychoanalysis, e.g. philosophy, sociology, aesthetics, history of art and literature, and more recently cognitive science/neuroscience. In the present phase of psychoanalytic pluralism, of worldwide scientifi c communication among psychoanalysts irrespective of language differences and furthermore of an intensifying dialogue with other disciplines, the relevance of conceptual research is steadily increasing. Yet, it still often seems insuffi ciently clear how conceptual research can be differentiated from clinical and empirical research in psychoanalysis. Therefore, the Subcommittee for Conceptual Research of the IPA presents some of its considerations on the similarities and the differences between various forms of clinical and extraclinical research, their specifi c aims, quality criteria and thus their specifi c chances as well as their specifi c limitations in this paper. Examples taken from six issues of the International Journal of Psychoanalysis in 2002-3 serve as illustrations for seven different subtypes of conceptual research. [source]