295 research outputs found
SOCIAL CAPITAL AND HOUSEHOLD INCOME DISTRIBUTIONS: EVIDENCE FROM MICHIGAN AND ILLINOIS
Social capital is a resource increasingly recognized as having important economic and social consequences. Robison and Siles (1999) examined some of these consequences at the U.S. state level and this study extends their efforts. Their 1999 study found important connections between the distributions of social capital and the distributions of household incomes. This study asks if the relationships between social capital and household incomes discovered at the state level are also present at the community level.Consumer/Household Economics, Institutional and Behavioral Economics,
Seasonal Diet Composition of Black Bullhead (Ameiurus melas) in Lake Carl Etling, Oklahoma
Black Bullhead (Ameiurus melas) is the most common of the three species of Ameriurus present in Oklahoma. They range across the state and inhabit any aquatic eco-system. However, little is known about their feeding habits. Food habits of Black Bullheads (95-318 mm total length) collected from June 2015 through May 2016 at Lake Carl Etling revealed a broad range of prey items. The total food volume of the 408 stomachs examined was comprised of sixteen different prey items (5 fish species, 5 crustacean species, 3 species of insects, and 3 plant species). No significant difference was found between seasons. Overall, fish had the highest index of relative importance (IRI; 88.5) with crustaceans having the lowest IRI (2.1), while insects and plants had similar IRI (5.8 and 5.5). Gizzard Shad were found to be the most frequent diet item consumed. Black Bullheads exhibit a mixed feeding strategy with varying degrees of specialization. Fish were most important prey item of Black Bullheads, while bullheads occasionally consumed crustaceans, insects or plants showing a higher between-phenotype component. It appears that Black Bullheads are highly piscivorous in Lake Carl Etling. Due to this finding, consideration of dietoverlap and fish forage availability is critical when fisheries managers are considering management strategies for other top predators or when contemplating the introduction of a new species into an aquatic system containing Black Bullhead
GABA transporter function, oligomerization state, and anchoring: correlates with subcellularly resolved FRET
The mouse γ-aminobutyric acid (GABA) transporter mGAT1 was expressed in neuroblastoma 2a cells. 19 mGAT1 designs incorporating fluorescent proteins were functionally characterized by [^3H]GABA uptake in assays that responded to several experimental variables, including the mutations and pharmacological manipulation of the cytoskeleton. Oligomerization and subsequent trafficking of mGAT1 were studied in several subcellular regions of live cells using localized fluorescence, acceptor photobleach Förster resonance energy transfer (FRET), and pixel-by-pixel analysis of normalized FRET (NFRET) images. Nine constructs were functionally indistinguishable from wild-type mGAT1 and provided information about normal mGAT1 assembly and trafficking. The remainder had compromised [^3H]GABA uptake due to observable oligomerization and/or trafficking deficits; the data help to determine regions of mGAT1 sequence involved in these processes. Acceptor photobleach FRET detected mGAT1 oligomerization, but richer information was obtained from analyzing the distribution of all-pixel NFRET amplitudes. We also analyzed such distributions restricted to cellular subregions. Distributions were fit to either two or three Gaussian components. Two of the components, present for all mGAT1 constructs that oligomerized, may represent dimers and high-order oligomers (probably tetramers), respectively. Only wild-type functioning constructs displayed three components; the additional component apparently had the highest mean NFRET amplitude. Near the cell periphery, wild-type functioning constructs displayed the highest NFRET. In this subregion, the highest NFRET component represented ~30% of all pixels, similar to the percentage of mGAT1 from the acutely recycling pool resident in the plasma membrane in the basal state. Blocking the mGAT1 C terminus postsynaptic density 95/discs large/zona occludens 1 (PDZ)-interacting domain abolished the highest amplitude component from the NFRET distributions. Disrupting the actin cytoskeleton in cells expressing wild-type functioning transporters moved the highest amplitude component from the cell periphery to perinuclear regions. Thus, pixel-by-pixel NFRET analysis resolved three distinct forms of GAT1: dimers, high-order oligomers, and transporters associated via PDZ-mediated interactions with the actin cytoskeleton and/or with the exocyst
Influence of keel impacts and laying hen behavior on keel bone damage.
Keel bone damage, which presents as fractures and/or deviations of the keel, has been detected in laying hens housed in all types of systems. Factors leading to keel bone damage in hens housed with limited vertical space, such as those housed in furnished systems, are not well understood, and are the topic of this study. Ten focal hens from each of 12 furnished cages (4 rooms of 3 cages) were fitted with keel mounted tri-axial accelerometers. Their behavior was video recorded continuously over two 3-wk trials: the first when the hens were between 52 and 60 wk of age, and the second approximately 20 wk later. The integrity of each hen's keel was evaluated at the start and end of each 3-wk trial using digital computed tomography. We identified predominant behaviors associated with acceleration events sustained at the keel (collisions, aggressive interactions and grooming) by pairing accelerometer outputs with video data. For each recorded acceleration event we calculated the acceleration magnitudes as the maximum summed acceleration recorded during the event, and by calculating the area under the acceleration curve. A principle components analysis, which was used as a data reduction technique, resulted in the identification of 4 components that were used in a subsequent regression analysis. A key finding is that the number of collisions a hen has with structures in her environment, and the number of aggressive interactions that a hen is involved, each affect the likelihood that she will develop 1 or more fractures within a 3-wk time span. This relationship between hen behavior and keel fracture formation was independent of the magnitude of acceleration involved in the event. Observed behavior did not have an impact on the formation of keel bone deviations, further supporting reports that the mechanisms underlying the 2 types of keel bone damage are different
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
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Class dynamics of development: a methodological note
This article argues that class relations are constitutive of developmental processes and central to understanding inequality within and between countries. In doing so it illustrates and explains the diversity of the actually existing forms of class relations, and the ways in which they interplay with other social relations such as gender and ethnicity. This is part of a wider project to re- vitalise class analysis in the study of development problems and experiences
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William (Bill) M. Hamner (1939–2024)
William (“Bill”) M. Hamner, a pioneer of ethological studies of avian and aquatic organisms who changed the way we think, particularly about the gelatinous zooplankton that suffuse the world’s oceans, died on 06 June, age 84 (Figure 1). Bill’s innovative approach to investigating pelagic animals married simple observation with unconventional methods in novel situations. This work spanned a half-century, beginning when he boldly moved marine science off the deck of ships, out of undiscriminating trawls that tend to macerate specimens, away from the accessible intertidal zone, and into the blue water of the pelagic realm. Bill’s ethological approach defined much of his life’s work and took him to extreme tropical outposts, the frigid waters of the Antarctic, and the depths of the ocean, always with his life-long collaborator in science and life, Peggy Hamner
A preliminary assessment on use of biochar as a soil additive for reducing the soil-to-plant update of cesium isotopes in radioactively contaminated environments
peer-reviewedA series of Kd tracer batch experiments were conducted to assess the absorptive-desorption properties of Biochar as a potential agent to selectively sequester labile soil Cs or otherwise help reduce the uptake of Cs isotopes into plants. A parallel experiment was conducted for strontium. Fine-grained fractionated Woodlands tree Biochar was found to have a relatively high affinity for Cs ions (Kd > 100) in comparison with untreated coral soil (Kd < 10) collected from the Marshall Islands. The Biochar material also contains an abundance of K (and Mg). These findings support a hypothesis that the addition of Biochar as a soil amendment may provide a simple yet effective method for reducing the soil-to-plant transfer of Cs isotopes in contaminated environments
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