1,405 research outputs found
Social Capital and Cultural Participation: Spousal Influences on Attendance at Arts Events
Empirical efforts to study the determinants of participation in the arts have demonstrated that adult attendance at arts events is influenced by adolescent exposure to the arts, educational attainment, and current income. While many have illuminated the impact of family socialization and individual characteristics, they have neglected the ways in which people’s social relationships influence their adult participation in the arts. This paper begins to redress this imbalance by focusing on the role of one crucial relationship—the tie between spouses—in shaping attendance at arts events. The importance of social ties is demonstrated by the finding that spouse’s background has an impact on an individual’s arts participation comparable to one’s own characteristics and that this effect persists even net of one’s spouse’s own attendance. Consistent with theories of a gendered division of cultural labor, men’s attendance is more strongly influenced by spousal characteristics than is women’s attendance.
Stress evaluation and design methodology for products with protective coatings
Call number: LD2668 .T4 ME 1987 T56Master of ScienceMechanical and Nuclear Engineerin
Assessing Alternatives for Directional Detection of a WIMP Halo
The future of direct terrestrial WIMP detection lies on two fronts: new, much
larger low background detectors sensitive to energy deposition, and detectors
with directional sensitivity. The former can large range of WIMP parameter
space using well tested technology while the latter may be necessary if one is
to disentangle particle physics parameters from astrophysical halo parameters.
Because directional detectors will be quite difficult to construct it is
worthwhile exploring in advance generally which experimental features will
yield the greatest benefits at the lowest costs. We examine the sensitivity of
directional detectors with varying angular tracking resolution with and without
the ability to distinguish forward versus backward recoils, and compare these
to the sensitivity of a detector where the track is projected onto a
two-dimensional plane. The latter detector regardless of where it is placed on
the Earth, can be oriented to produce a significantly better discrimination
signal than a 3D detector without this capability, and with sensitivity within
a factor of 2 of a full 3D tracking detector. Required event rates to
distinguish signals from backgrounds for a simple isothermal halo range from
the low teens in the best case to many thousands in the worst.Comment: 4 pages, including 2 figues and 2 tables, submitted to PR
Situational Frequency and Retrieval: The Effect of Revelation on the Judgments for Occurrence of Events.
Only one prior experiment has examined the effect of revelation on situational frequency judgments (Exp. 3, Greene, 1996). In the current study, three experiments examined the effect of revelation on frequency estimation. Experiment 1A and 1B replicated and extended the study done by Greene (1996) by increasing the frequencies of study items from one to eight in both a random (1A) and blocked (1B) design. Experiment 2 examined the relation between the frequency of study items and the degree of distortion of the items revealed at test. A significant effect of revelation was found across frequencies for the three revealed conditions compared to an intact condition. Experiment 3 examined the effect of familiarity within a frequency estimation task. A significant revelation effect was found across frequencies despite the fact that the word that was revealed was different from the word that was being judged for frequency. This series of experiments showed a robust effect of revelation on frequency estimation. The finding that frequency estimation is affected by manipulations that occur only at retrieval poses a problem for a strict automatic explanation for frequency encoding. Theories of frequency estimation involving retrieval are discussed
The cellular response to ocean warming in Emiliania huxleyi
Marine phytoplankton contribute substantially to the global flux of carbon from the atmosphere to the deep ocean. Sea surface temperatures will inevitably increase in line with global climate change, altering the performance of marine phytoplankton. Differing sensitivities of photosynthesis and respiration to temperature, will likely shift the strength of the future oceanic carbon sink. To further clarify the molecular mechanisms driving these alterations in phytoplankton function, shotgun proteomic analysis was carried out on the globally-occurring coccolithophore Emiliania huxleyi exposed to moderate- (23°C) and elevated- (28°C) warming. Compared to the control (17°C), growth of E. huxleyi increased under elevated temperatures, with higher rates recorded under moderate- relative to elevated- warming. Proteomic analysis revealed a significant modification of the E. huxleyi cellular proteome as temperatures increased: at lower temperature, ribosomal proteins and photosynthetic machinery appeared abundant, as rates of protein translation and photosynthetic performance are restricted by low temperatures. As temperatures increased, evidence of heat stress was observed in the photosystem, characterized by a relative down-regulation of the Photosystem II oxygen evolving complex and ATP synthase. Acclimation to elevated warming (28°C) revealed a substantial alteration to carbon metabolism. Here, E. huxleyi made use of the glyoxylate cycle and succinate metabolism to optimize carbon use, maintain growth and maximize ATP production in heat-damaged mitochondria, enabling cultures to maintain growth at levels significantly higher than those recorded in the control (17°C). Based on the metabolic changes observed, we can predict that warming may benefit photosynthetic carbon fixation by E. huxleyi in the sub-optimal to optimal thermal range. Past the thermal optima, increasing rates of respiration and costs of repair will likely constrain growth, causing a possible decline in the contribution of this species to the oceanic carbon sink depending on the evolvability of these temperature thresholds
Shotgun proteomics reveals temperature-dependent regulation of major nutrient metabolism in coastal Synechococcus sp. WH5701
Marine cyanobacteria are major contributors to the oceanic carbon sink and are predicted to increase in numbers in the future warmed ocean. As a result, the influence of marine cyanobacteria on marine biogeochemical cycling will likely be enhanced. Associated with elevations in temperature the ocean will undergo increased stratification, reducing supply of essential nutrients to upper phototrophic layers. It is therefore critical that we resolve the manners by which cyanobacteria respond to variations in temperature, and consequences for major nutrient metabolism which may ultimately direct global biogeochemistry and trophic transfer. In this study we use the coastal Synechococcus sp. WH5701 to examine proteomic alterations in major nutrient (C, N and P) metabolic pathways following exposure to varying temperature. In response to temperature treatments, Synechococcus displayed higher rates of growth and photosynthetic efficiency when temperatures were raised from 17 °C, to 23 °C and 28 °C, associated with a significant ∼30–40 % alteration in the cellular proteome. As temperatures increased, proteomic investment towards photosynthetic machinery appeared up-regulated, whilst abundance of RuBisCO was reduced, associated with an apparent alteration in CCM composition and carbon metabolism. N demand appeared to increase in-line with temperature, associated with alterations in the GS-GOGAT pathway, likely due to increased demand for and efficiency of protein synthesis. In contrast, P demand at the highest temperature appeared reduced as investment in the ribosome declines due to improved translation efficiency, whilst luxury P-storage appeared a feature of growth at low temperature. It appears likely that as seawater temperatures rise under ocean warming, the biochemical composition of cyanobacteria will be altered, increasing cellular C- and N- to P ratios, ultimately impacting upon their contribution to oceanic biogeochemical cycling
Casimir-Polder forces, boundary conditions and fluctuations
We review different aspects of the atom-atom and atom-wall Casimir-Polder
forces. We first discuss the role of a boundary condition on the interatomic
Casimir-Polder potential between two ground-state atoms, and give a physically
transparent interpretation of the results in terms of vacuum fluctuations and
image atomic dipoles. We then discuss the known atom-wall Casimir-Polder force
for ground- and excited-state atoms, using a different method which is also
suited for extension to time-dependent situations. Finally, we consider the
fluctuation of the Casimir-Polder force between a ground-state atom and a
conducting wall, and discuss possible observation of this force fluctuation.Comment: 5 page
Genetic Drift Dominates Genome-Wide Regulatory Evolution Following an Ancient Whole-Genome Duplication in Atlantic Salmon
Whole-genome duplications (WGD) have been considered as springboards that potentiate lineage diversification through increasing functional redundancy. Divergence in gene regulatory elements is a central mechanism for evolutionary diversification, yet the patterns and processes governing regulatory divergence following events that lead to massive functional redundancy, such as WGD, remain largely unknown. We studied the patterns of divergence and strength of natural selection on regulatory elements in the Atlantic salmon (Salmo salar) genome, which has undergone WGD 100–80 Ma. Using ChIPmentation, we first show that H3K27ac, a histone modification typical to enhancers and promoters, is associated with genic regions, tissue-specific transcription factor binding motifs, and with gene transcription levels in immature testes. Divergence in transcription between duplicated genes from WGD (ohnologs) correlated with difference in the number of proximal regulatory elements, but not with promoter elements, suggesting that functional divergence between ohnologs after WGD is mainly driven by enhancers. By comparing H3K27ac regions between duplicated genome blocks, we further show that a longer polyploid state post-WGD has constrained regulatory divergence. Patterns of genetic diversity across natural populations inferred from resequencing indicate that recent evolutionary pressures on H3K27ac regions are dominated by largely neutral evolution. In sum, our results suggest that post-WGD functional redundancy in regulatory elements continues to have an impact on the evolution of the salmon genome, promoting largely neutral evolution of regulatory elements despite their association with transcription levels. These results highlight a case where genome-wide regulatory evolution following an ancient WGD is dominated by genetic drift.Peer reviewe
Modeling the thickness dependence of the magnetic phase transition temperature in thin FeRh films
FeRh and its first-order phase transition can open new routes for magnetic hybrid materials and devices under the assumption that it can be exploited in ultra-thin-film structures. Motivated by experimental measurements showing an unexpected increase in the phase transition temperature with decreasing thickness of FeRh on top of MgO, we develop a computational model to investigate strain effects of FeRh in such magnetic structures. Our theoretical results show that the presence of the MgO interface results in a strain that changes the magnetic configuration which drives the anomalous behavior
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