1,918 research outputs found
Developing an Effective Internal Affairs Policy of the Hillsboro Police Department
Discusses the need for a police department to have a written policy and procedure for complaints
Co-parenting: Using āIā messages
The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Measurements of resistance and reactance in fish with the use of bioelectrical impedance analysis: sources of error
New technologies can be riddled with unforeseen sources of
error, jeopardizing the validity and application of their advancement. Bioelectrical impedance analysis (BIA) is a new technology in fisheries research that is capable of estimating proximate composition, condition, and energy content in fish quickly, cheaply, and (after calibration) without the need to sacrifice fish. Before BIA can be widely accepted in fisheries science, it is necessary to identify sources of error and determine a means to minimize potential errors with this analysis. We conducted
controlled laboratory experiments to identify sources of errors within BIA measurements. We concluded that electrode needle location, procedure deviations, user experience,
time after death, and temperature can affect resistance and reactance measurements. Sensitivity analyses showed that errors in predictive estimates of composition can be large
(>50%) when these errors are experienced. Adherence to a strict protocol can help avoid these sources of error
and provide BIA estimates that are both accurate and precise in a field or laboratory setting
Recommended from our members
Artificial Light Increases Local Predator Abundance, Predation Rates, and Herbivory.
Human activity is rapidly increasing the radiance and geographic extent of artificial light at night (ALAN) leading to alterations in the development, behavior, and physiological state of many organisms. A limited number of community-scale studies investigating the effects of ALAN have allowed for spatial aggregation through positive phototaxis, the commonly observed phenomenon of arthropod movement toward light. We performed an open field study (without restricted arthropod access) to determine the effects of ALAN on local arthropod community composition, plant traits, and local herbivory and predation rates. We found strong positive phototaxis in 10 orders of arthropods, with increased (159% higher) overall arthropod abundance under ALAN compared to unlit controls. The arthropod community under ALAN was more diverse and contained a higher proportion of predaceous arthropods (15% vs 8%). Predation of immobilized flies occurred 3.6 times faster under ALAN; this effect was not observed during the day. Contrary to expectations, we also observed a 6% increase in herbivory under ALAN. Our results highlight the importance of open experimental field studies in determining community-level effects of ALAN
Mimesis stories: composing new nature music for the shakuhachi
Nature is a widespread theme in much new music for the shakuhachi (Japanese bamboo flute). This article explores the significance of such music within the contemporary shakuhachi scene, as the instrument travels internationally and so becomes rooted in landscapes outside Japan, taking on the voices of new creatures and natural phenomena. The article tells the stories of five compositions and one arrangement by non-Japanese composers, first to credit composersā varied and personal responses to this common concern and, second, to discern broad, culturally syncretic traditions of nature mimesis and other, more abstract, ideas about the naturalness of sounds and creative processes (which I call musical naturalism). Setting these personal stories and longer histories side by side reveals that composition creates composers (as much as the other way around). Thus it hints at much broader terrain: the refashioning of human nature at the confluence between cosmopolitan cultural circulations and contemporary encounters with the more-than-human world
The Effects of Gas on Morphological Transformation in Mergers: Implications for Bulge and Disk Demographics
Transformation of disks into spheroids via mergers is a well-accepted element
of galaxy formation models. However, recent simulations have shown that bulge
formation is suppressed in increasingly gas-rich mergers. We investigate the
global implications of these results in a cosmological framework, using
independent approaches: empirical halo-occupation models (where galaxies are
populated in halos according to observations) and semi-analytic models. In
both, ignoring the effects of gas in mergers leads to the over-production of
spheroids: low and intermediate-mass galaxies are predicted to be
bulge-dominated (B/T~0.5 at <10^10 M_sun), with almost no bulgeless systems),
even if they have avoided major mergers. Including the different physical
behavior of gas in mergers immediately leads to a dramatic change: bulge
formation is suppressed in low-mass galaxies, observed to be gas-rich (giving
B/T~0.1 at <10^10 M_sun, with a number of bulgeless galaxies in good agreement
with observations). Simulations and analytic models which neglect the
similarity-breaking behavior of gas have difficulty reproducing the strong
observed morphology-mass relation. However, the observed dependence of gas
fractions on mass, combined with suppression of bulge formation in gas-rich
mergers, naturally leads to the observed trends. Discrepancies between
observations and models that ignore the role of gas increase with redshift; in
models that treat gas properly, galaxies are predicted to be less
bulge-dominated at high redshifts, in agreement with the observations. We
discuss implications for the global bulge mass density and future observational
tests.Comment: 14 pages, 11 figures, accepted to MNRAS (matched published version).
A routine to return the galaxy merger rates discussed here is available at
http://www.cfa.harvard.edu/~phopkins/Site/mergercalc.htm
The effects of gas on morphological transformation in mergers: implications for bulge and disc demographics
Transformation of discs into spheroids via mergers is a well-accepted element of galaxy formation models. However, recent simulations have shown that the bulge formation is suppressed in increasingly gas-rich mergers. We investigate the global implications of these results in a cosmological framework, using independent approaches: empirical halo-occupation models (where galaxies are populated in haloes according to observations) and semi-analytic models. In both, ignoring the effects of gas in mergers leads to the overproduction of spheroids: low- and intermediate-mass galaxies are predicted to be bulge-dominated (B/Tā¼ 0.5 at <10Ā¹ā° M_ā, with almost no ābulgelessā systems), even if they have avoided major mergers. Including the different physical behaviour of gas in mergers immediately leads to a dramatic change: bulge formation is suppressed in low-mass galaxies, observed to be gas-rich (giving B/Tā¼ 0.1 at <10Ā¹ā° M_ā, with a number of bulgeless galaxies in good agreement with observations). Simulations and analytic models which neglect the similarity-breaking behaviour of gas have difficulty reproducing the strong observed morphologyāmass relation. However, the observed dependence of gas fractions on mass, combined with suppression of bulge formation in gas-rich mergers, naturally leads to the observed trends. Discrepancies between observations and models that ignore the role of gas increase with redshift; in models that treat gas properly, galaxies are predicted to be less bulge-dominated at high redshifts, in agreement with the observations. We discuss implications for the global bulge mass density and future observational tests
- ā¦