483 research outputs found
Nestling Provisioning Of Dickcissels In Native Warm-Season Grass Field Buffers
Grassland birds must have accessible, nutritional prey for nestlings which Conservation Reserve Program practices like CP33âHabitat Buffers for Upland Birds may provide. In 2008â2009, I monitored dickcissel nests in and around CP33 buffers at a farm in north-central Mississippi using video cameras to capture provisioning activities. I simultaneously observed foraging flights and measured distances traveled from nests. Orthopterans were the most commonly chosen prey, and dickcissels brought larger prey items when chicks were older. But, other changes in provisioning were not significantly related to nest age as I hypothesized. Also contrary to my initial hypotheses, provisioning at nests within buffers did not differ from non-buffer nests. CRP grasslands were equivalent to other available habitats. Provisioning rate and biomass decreased when an observer was present, and male feeding increased provisioning rate. Incorporating native warm-season grasses through conservation programs can increase nesting and foraging resources for dickcissels
Beyond the Cartesian Self
I review a number of approaches that attempt to deal with the gap that seems to exist between first-person and third-person accounts of consciousness, and some of the conceptual, epistemological, and methodological issues that surround this distinction. I argue, with reference to Carnap and Schrödinger, that one cannot simply reduce data from the first-person perspective to third-person data, without remainder, especially when the very subject matter of the science includes the first-person perspective
Ground motion selection for simulation-based seismic hazard and structural reliability assessment
This paper examines four methods by which ground motions can be selected for
dynamic seismic response analyses of engineered systems when the underlying
seismic hazard is quantified via ground motion simulation rather than empirical
ground motion prediction equations. Even with simulation-based seismic hazard, a
ground motion selection process is still required in order to extract a small number of
time series from the much larger set developed as part of the hazard calculation. Four
specific methods are presented for ground motion selection from simulation-based
seismic hazard analyses, and pros and cons of each are discussed via a simple and
reproducible illustrative example. One of the four methods (method 1 âdirect
analysisâ) provides a âbenchmarkâ result (i.e. using all simulated ground motions),
enabling the consistency of the other three more efficient selection methods to be
addressed. Method 2 (âstratified samplingâ) is a relatively simple way to achieve a
significant reduction in the number of ground motions required through selecting
subsets of ground motions binned based on an intensity measure, IM. Method 3
(âsimple multiple stripesâ) has the benefit of being consistent with conventional
seismic assessment practice using as-recorded ground motions, but both methods 2
and 3 are strongly dependent on the efficiency of the conditioning IM to predict the
seismic responses of interest. Method 4 (âGCIM-based selectionâ) is consistent with
âadvancedâ selection methods used for as-recorded ground motions, and selects
subsets of ground motions based on multiple IMs, thus overcoming this limitation in
methods 2 and 3
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