Hydrogen as a Source of Flux Noise in SQUIDs

Superconducting qubits are hampered by flux noise produced by surface spins from a variety of microscopic sources. Recent experiments indicated that hydrogen (H) atoms may be one of those sources. Using density functional theory calculations, we report that H atoms either embedded in, or adsorbed on, an a-Al2O3(0001) surface have sizeable spin moments ranging from 0.81 to 0.87 uB with energy barriers for spin reorientation as low as ~10 mK. Furthermore, H adatoms on the surface attract gas molecules such as O2, producing new spin sources. We propose coating the surface with graphene to eliminate H-induced surface spins and to protect the surface from other adsorbates.Comment: 12 pages, 4 figure

Accounting Standards Harmonization and Financial Statement Comparability: Evidence From Transnational Information Transfer

This paper investigates whether accounting standards harmonization enhances the comparability of financial information across countries. I hypothesize that a firm yet to announce earnings reacts more strongly to the earnings announcement of a foreign firm when both report under the same rather than different accounting standards. My analysis of abnormal price reactions for a global sample of firms supports the prediction. Next, in an attempt to control for the underlying economic comparability and the effects of changes in reporting quality, I use a difference-in-differences design around the mandatory introduction of International Financial Reporting Standards. I find that mandatory adopters experience a significant increase in market reactions to the release of earnings by voluntary adopters compared to the period preceding mandatory adoption. This increase is not observed for nonadopters. Taken together, the results show that accounting standards harmonization facilitates transnational information transfer and suggest financial statement comparability as a direct mechanism

Experience and experiments in integrating ecology and environmental policy in an undergraduate curriculum

In 1986 the School of Natural Resources (SNR) embarked on a project to define and implement an undergraduate core curriculum that integrates natural and social science in the context of natural resource education. Currently this curriculum includes seven courses (21 credits) taken over five semesters beginning in the student\u27s first semester and ending in their last year. At the outset, the students take two separate introductory courses, one introducing them to concepts in natural science and the other introducing them to natural resources from a social and cultural perspective. This paper describes the next phase of their curricular experience, a set of three courses taken concurrently. The overall goals of the courses are to introduce and integrate theories and approaches to analysis in ecology and social science as applied to environmental issues. This paper describes our use of the concept of integration in the context of natural resource education and three models for incorporating it into this portion of the SNR Core Curriculum. Our working definition of integration involves three levels: (1) process-logistics integration, and (3) framework integration. The first is related to the process of establishing and delivering the courses including management of instructor, student, and teaching assistant roles across the disciplines. The second is related to bringing together ecological and social science knowledge to provide different views of a single natural resource case or issue. The third is related to recognizing and using conceptual frameworks shared across ecological and social science

Exogenous Credit Rating Changes and the Provision of Voluntary Disclosure

We provide evidence suggesting that corporate credit rating changes have an effect on firms’ voluntary disclosure behavior that is independent of the information they convey about firm fundamentals. Our analyses exploit two separate quasi-experimental settings that generate either exogenous credit rating downgrades or credit rating upgrades that allow us to isolate the effect of the credit rating label from changes in firms’ credit quality. We find evidence of a negative relation between the direction of the credit rating change and the provision of voluntary disclosure in both settings—firms respond to exogenous downgrades by increasing voluntary disclosure and to exogenous upgrades by decreasing voluntary disclosure. Overall, our analyses indicate that credit rating agencies as information intermediaries influence firms’ provision of voluntary disclosure

Dividend Payouts and Information Shocks

This paper examines changes in firms’ dividend payouts following an exogenous shock to the information environment. Traditional signaling, agency, and voluntary disclosure models predict that the more is commonly known about a firm and its competitors in the marketplace, the less private information managers will have to reveal themselves via costly signals or cash disbursements. To test these predictions, we analyze the dividend payment behavior for a global sample of firms around the mandatory adoption of IFRS and around the initial enforcement of new insider trading laws. Both events have the potential to improve the general information environment in the economy. We find that following the two events firms are less likely to pay (or increase) cash dividends, but more likely to cut (or stop) such payments. The changes in dividend policy occur around the time of the informational shock and only in countries and for firms subject to the regulatory change. In further analyses we find that the information content of dividends, measured as three-day absolute announcement returns, is lower after the informational events. The findings underscore that firms’ payout policies, among other things, depend on the extent of information about all firms in the economy

BCL-W has a fundamental role in B cell survival and lymphomagenesis.

Compromised apoptotic signaling is a prerequisite for tumorigenesis. The design of effective therapies for cancer treatment depends on a comprehensive understanding of the mechanisms that govern cell survival. The antiapoptotic proteins of the BCL-2 family are key regulators of cell survival and are frequently overexpressed in malignancies, leading to increased cancer cell survival. Unlike BCL-2 and BCL-XL, the closest antiapoptotic relative BCL-W is required for spermatogenesis, but was considered dispensable for all other cell types. Here, however, we have exposed a critical role for BCL-W in B cell survival and lymphomagenesis. Loss of Bcl-w conferred sensitivity to growth factor deprivation-induced B cell apoptosis. Moreover, Bcl-w loss profoundly delayed MYC-mediated B cell lymphoma development due to increased MYC-induced B cell apoptosis. We also determined that MYC regulates BCL-W expression through its transcriptional regulation of specific miR. BCL-W expression was highly selected for in patient samples of Burkitt lymphoma (BL), with 88.5% expressing BCL-W. BCL-W knockdown in BL cell lines induced apoptosis, and its overexpression conferred resistance to BCL-2 family-targeting BH3 mimetics. Additionally, BCL-W was overexpressed in diffuse large B cell lymphoma and correlated with decreased patient survival. Collectively, our results reveal that BCL-W profoundly contributes to B cell lymphoma, and its expression could serve as a biomarker for diagnosis and aid in the development of better targeted therapies

Interaction of the oncoprotein transcription factor MYC with its chromatin cofactor WDR5 is essential for tumor maintenance.

The oncoprotein transcription factor MYC is overexpressed in the majority of cancers. Key to its oncogenic activity is the ability of MYC to regulate gene expression patterns that drive and maintain the malignant state. MYC is also considered a validated anticancer target, but efforts to pharmacologically inhibit MYC have failed. The dependence of MYC on cofactors creates opportunities for therapeutic intervention, but for any cofactor this requires structural understanding of how the cofactor interacts with MYC, knowledge of the role it plays in MYC function, and demonstration that disrupting the cofactor interaction will cause existing cancers to regress. One cofactor for which structural information is available is WDR5, which interacts with MYC to facilitate its recruitment to chromatin. To explore whether disruption of the MYC-WDR5 interaction could potentially become a viable anticancer strategy, we developed a Burkitt\u27s lymphoma system that allows replacement of wild-type MYC for mutants that are defective for WDR5 binding or all known nuclear MYC functions. Using this system, we show that WDR5 recruits MYC to chromatin to control the expression of genes linked to biomass accumulation. We further show that disrupting the MYC-WDR5 interaction within the context of an existing cancer promotes rapid and comprehensive tumor regression in vivo. These observations connect WDR5 to a core tumorigenic function of MYC and establish that, if a therapeutic window can be established, MYC-WDR5 inhibitors could be developed as anticancer agents

Effects of Atmospheric Gases on Li Metal Cyclability and Solid-Electrolyte Interphase Formation.

For Li-air batteries, dissolved gas can cross over from the air electrode to the Li metal anode and affect the solid-electrolyte interphase (SEI) formation, a phenomenon that has not been fully characterized. In this work, the impact of atmospheric gases on the SEI properties is studied using electrochemical methods and ex situ characterization techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The presence of O2 significantly improved the lithium cyclability; less lithium is consumed to form the SEI or is lost because of electrical disconnects. However, the SEI resistivity and plating overpotentials increased. Lithium cycled in an "air-like" mixed O2/N2 environment also demonstrated improved cycling efficiency, suggesting that dissolved O2 participates in electrolyte reduction, forming a homogeneous SEI, even at low concentrations. The impact of gas environments on Li metal plating and SEI formation represents an additional parameter in designing future Li-metal batteries

Universal endogenous gene controls for bisulphite conversion in analysis of plant DNA methylation

Accurate analysis of DNA methylation by bisulphite sequencing depends on the complete conversion of all cytosines into uracil. Until now there has been no standard or universal gene identified as an endogenous control to monitor the conversion frequency in plants. Here, we report the development of PCR based assays for one nuclear gene IND (INDEHISCENT) and two mitochondrial genes, NAD (NICOTINAMIDE ADENINE DINUCLEOTIDE) and ATP1 (ATPase SUBUNIT 1). We demonstrated their efficacy as bisulphite conversion controls in Brassica and other plant taxa. The target regions amplified by four primer pairs were found to be consistently free from DNA methylation. Primer pairs for IND.a and NAD were effective within Brassica species, whereas two primer pairs for ATP1 provided reliable controls across a representative range of dicot and monocot angiosperm species. These primer sets may therefore be adopted as controls in plant methylation analysis for a wide range of studies