1,015 research outputs found
A Tale of Two Paradigms: How Genealogical and Comparative Historical analysis can help reset the intractable debate over the causation of ideological violence
This study responds to the endemic lack of clarity and consensus afflicting
academic and policy discussions on the causes of ideological violence and, by
extension, the appropriate means for preventing/containing it. I trace,
conceptualise, and problematise the long-standing debate between two deeply entrenched oppositional camps or ‘paradigms’ – heuristically dubbed the
‘conservative’ and ‘progressive’ paradigms of ideological violence, respectively –
that propose competing explanations for the causation of ideological violence; the
former considering it a product of irrational individual dysfunction, the latter
viewing it as a rational (if often misguided) response to societal dysfunction.
Further, I show that extant attempts at reconciling/synthesising these paradigms
have, to date, proven problematic. I explore how and why these opposing
paradigms emerged and why debate between them persists. I argue that they are
shaped, perpetuated and marred by multiple extra-academic dynamics and
naturalised assumptions and conclude that clarity and consensus is unlikely
unless we can ‘reset’ the debate, making a conscious decision to ‘step back’ from
our extant paradigms/assumptions and approach the phenomenon with fresh
eyes. I propose and demonstrate two methodological approaches that – used in
conjunction – can contribute towards this end. Firstly, I propose that – and
demonstrate how - Genealogical Analysis can aid in this ‘stepping back’ by
denaturalising our entrenched assumptions on the causes of ideological violence
(i.e., our extant paradigms) by uncovering how and why those assumptions came
to be held and reified. Secondly, I propose and demonstrate Comparative
Historical Analysis’ utility as a tool that can aid in re-approaching the phenomena
with fresh eyes by helping - gradually and collaboratively - to construct a new set
of more methodologically-rigorous assumptions (i.e., a new paradigm) upon
which extant research built upon either extant paradigm can be resituated,
reinterpreted, de-limited, and synthesised, and further research can be premised
Remote sensing of coccolithophore blooms in selected oceanic regions using the PhytoDOAS method applied to hyper-spectral satellite data
In this study temporal variations of coccolithophore blooms are investigated using satellite data. Eight years (from 2003 to 2010) of data of SCIAMACHY, a hyper-spectral satellite sensor on-board ENVISAT, were processed by the PhytoDOAS method to monitor the biomass of coccolithophores in three selected regions. These regions are characterized by frequent occurrence of large coccolithophore blooms. The retrieval results, shown as monthly mean time series, were compared to related satellite products, including the total surface phytoplankton, i.e. total chlorophyll a (from GlobColour merged data) and the particulate inorganic carbon (from MODIS-Aqua). The inter-annual variations of the phytoplankton bloom cycles and their maximum monthly mean values have been compared in the three selected regions to the variations of the geophysical parameters: sea-surface temperature (SST), mixed-layer depth (MLD) and surface wind-speed, which are known to affect phytoplankton dynamics. For each region, the anomalies and linear trends of the monitored parameters over the period of this study have been computed. The patterns of total phytoplankton biomass and specific dynamics of coccolithophore chlorophyll a in the selected regions are discussed in relation to other studies. The PhytoDOAS results are consistent with the two other ocean color products and support the reported dependencies of coccolithophore biomass dynamics on the compared geophysical variables. This suggests that PhytoDOAS is a valid method for retrieving coccolithophore biomass and for monitoring its bloom developments in the global oceans. Future applications of time series studies using the PhytoDOAS data set are proposed, also using the new upcoming generations of hyper-spectral satellite sensors with improved spatial resolution
Electron propagation in crossed magnetic and electric fields
Laser-atom interaction can be an efficient mechanism for the production of
coherent electrons. We analyze the dynamics of monoenergetic electrons in the
presence of uniform, perpendicular magnetic and electric fields. The Green
function technique is used to derive analytic results for the field--induced
quantum mechanical drift motion of i) single electrons and ii) a dilute Fermi
gas of electrons. The method yields the drift current and, at the same time it
allows us to quantitatively establish the broadening of the (magnetic) Landau
levels due to the electric field: Level number k is split into k+1 sublevels
that render the th oscillator eigenstate in energy space. Adjacent Landau
levels will overlap if the electric field exceeds a critical strength. Our
observations are relevant for quantum Hall configurations whenever electric
field effects should be taken into account.Comment: 11 pages, 2 figures, submitte
Four-path interference and uncertainty principle in photodetachment microscopy
We study the quantal motion of electrons emitted by a pointlike monochromatic
isotropic source into parallel uniform electric and magnetic fields. The
two-path interference pattern in the emerging electron wave due to the electric
force is modified by the magnetic lens effect which periodically focuses the
beam into narrow filaments along the symmetry axis. There, four classical paths
interfere. With increasing electron energy, the current distribution changes
from a quantum regime governed by the uncertainty principle, to an intricate
spatial pattern that yields to a semiclassical analysis.Comment: submitted to Europhysics Letter
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