ASU Scholarship Showcase

Membrane proteins are key players in biological systems, mediating signalling events and the specific transport of e.g. ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX) for the structure determination of membrane protein-ligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data reveal the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.

Objective: To estimate the absolute wealth of households using data from demographic and health surveys.

Methods: We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures.

Findings: The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723-6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R-2=0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes.

Conclusion: Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality.

A catalytic site typically consists of one or more atoms of a catalyst surface that arrange into a configuration offering a specific electronic structure for adsorbing or dissociating reactant molecules. The catalytic activity of adjacent bimetallic sites of metallic nanoparticles has been studied previously. An isolated bimetallic site supported on a non-metallic surface could exhibit a distinctly different catalytic performance owing to the cationic state of the singly dispersed bimetallic site and the minimized choices of binding configurations of a reactant molecule compared with continuously packed bimetallic sites. Here we report that isolated Rh1Co3 bimetallic sites exhibit a distinctly different catalytic performance in reduction of nitric oxide with carbon monoxide at low temperature, resulting from strong adsorption of two nitric oxide molecules and a nitrous oxide intermediate on Rh1Co3 sites and following a low-barrier pathway dissociation to dinitrogen and an oxygen atom. This observation suggests a method to develop catalysts with high selectivity.

The Career Decision Ambiguity Tolerance Scale (CDAT) measures individual evaluations of and responses to ambiguity encountered in career decision making. It was developed and initially validated through two studies of college students. An exploratory and confirmatory factor analysis consistently showed a three-factor structure for career decision ambiguity tolerance, consisting of preference, tolerance, and aversion. In addition to support for construct validity and subscale reliabilities, the findings also support the scale's incremental validity in predicting career indecision, career decision-making self-efficacy, and career adaptability over and beyond general ambiguity tolerance. The theoretical meaning and practical application of the CDAT were discussed along with its limitations and suggestions for future research.

A reciprocal influence model of the working alliance and the therapeutic outcome was examined in a sample of clients (n = 638) seen by novice therapists. Past researchers have found a relation between the working alliance and symptom improvement and this relation has been interpreted as the alliance leading to such symptom change. The current study was an examination of whether the alliance does indeed lead to symptom change, or whether symptom change leads to subsequent alliance change, or whether each is related to the other in a reciprocal way over time. By modeling the longitudinal development of the working alliance and the symptomatic severity over the individual therapy course, we found support for the reciprocal model being superior to the unidirectional models. The ideas of relationship as strategy and relationship as outcome along with the reciprocal pattern revealed in the findings were discussed with respect to the theoretical and clinical implications. We also discussed the limitations of the study and provided suggestions for future research.

In this welcome anthology, Tina Frühauf publishes solo organ music by Jewish composers from the early 19th through the mid-20th centuries, making known to organists and scholars a fascinating repertoire that was largely obscured by the Holocaust. Frühauf has established herself as an expert on the subject with her monograph, The Organ and Its Music in German-Jewish Culture. In her preface to the musical edition, she explains that the anthology complements her book, since it includes scores of some of the music she has previously analyzed. She made her selections to ‘trace the history and major stylistic developments of organ music in the German-speaking Jewish communities of central Europe, parts of eastern Europe, and finally in the United States and Israel, where many composers emigrated to escape from Nazi persecution’ (vii). This music reveals a rich culture of Jewish organ playing that was virtually extinguished by the devastation of World War II.

In this work, a selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF₂ spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the fabricated solar absorber is characterized to be higher than 0.9 in the UV, visible and, near infrared (IR) regime, while the mid-IR emittance is around 0.2. The high broadband absorption in the solar spectrum is realized by the excitation of surface plasmon and magnetic polariton resonances, while the low mid-IR emittance is due to the highly reflective nature of the metallic components. Further directional and polarized reflectance measurements show wide-angle and polarization-insensitive high absorption within solar spectrum. Temperature-dependent spectroscopic characterization indicates that the optical properties barely change at elevated temperatures up to 350 °C. The solar-to-heat conversion efficiency with the fabricated metamaterial solar absorber is predicted to be 78% at 100 °C without optical concentration or 80% at 400 °C with 25 suns. The performance could be further improved with better fabrication processes and geometric optimization during metamaterial design. The strong spectral selectivity, favorable diffuse-like behavior, and good thermal stability make the metamaterial selective absorber promising for significantly enhancing solar thermal energy harvesting in various systems at mid to high temperatures.

Political liberals are significantly more supportive than conservatives of walkable, mixed-use neighborhoods, transit-oriented development, and other aspects of the “compact city,” not just in their views about government policy toward metropolitan development but also in their consumption preferences regarding neighborhoods. I argue that social psychologists’ theory of moral intuitionism helps account for these differences. In this view, liberals and conservatives emphasize different sets of affective, emotion-laden moral impulses—such as those involving fairness, purity, or ingroup loyalty—predisposing them toward particular reactions to compact development. Political ideologies also are associated with different personality traits that are relevant to opinions on the built environment. To explore the intuitionist hypothesis, I review qualitative accounts that suggest an association between certain moral worldviews and attitudes toward development patterns. I then conduct multivariate analysis of a public opinion survey that contained questions relevant to moral foundations and to views on compact development.

Many important electricity policy initiatives would directly affect the operation of electric power networks. This paper develops a method for estimating short-run zonal supply curves in transmission-constrained electricity markets that can be implemented quickly by policy analysts with training in statistical methods and with publicly available data. Our model enables analysis of distributional impacts of policies affecting operation of electric power grid. The method uses fuel prices and zonal electric loads to determine piecewise supply curves, identifying zonal electricity price and marginal fuel. We illustrate our methodology by estimating zonal impacts of Pennsylvania's Act 129, an energy efficiency and conservation policy. For most utilities in Pennsylvania, Act 129 would reduce the influence of natural gas on electricity price formation and increase the influence of coal. The total resulted savings would be around 267 million dollars, 82 percent of which would be enjoyed by the customers in Pennsylvania. We also analyze the impacts of imposing a $35/ton tax on carbon dioxide emissions. Our results show that the policy would increase the average prices in PJM by 47–89 percent under different fuel price scenarios in the short run, and would lead to short-run interfuel substitution between natural gas and coal.

This article assesses Southeast Asian views of the US “rebalance,” examining reactions to US military deployments, military assistance to partners, and support for Southeast Asian diplomacy on South China Sea conflicts. Although not ostensibly designed to contain China, the rebalance provides Southeast Asia with hedging options against more assertive PRC actions in the South China Sea.