Models of Stochastic, Spatially Varying Stress in the Crust Compatible with Focal-Mechanism Data, and How Stress Inversions Can Be Biased toward the Stress Rate

Evidence suggests that slip in earthquakes and the resultant stress changes are spatially heterogeneous. If crustal stress from past earthquakes is spatially heterogeneous, then earthquake focal mechanisms should also be spatially variable. We describe the statistical attributes of simulated earthquake catalogs, including hypocenters and focal mechanisms, for a spatially 3D, time-varying model of the crustal stress tensor with stochastic spatial variations. It is assumed that temporal variations in stress are spatially smooth and are primarily caused by plate tectonics. Spatial variations in stress are assumed to be the result of past earthquakes and are independent of time for periods between major earthquakes. It is further assumed that heterogeneous stress can be modeled as a stochastic process that is specified by an autocorrelation function. Synthetic catalogs of earthquake hypocenters and their associated focal mechanisms are produced by identifying the locations and times at which the second deviatoric stress invariant exceeds a specified limit. The model produces a seismicity catalog that is spatially biased. The only points in the grid that exceed the failure stress are those where the heterogeneous stress is approximately aligned with the stress rate. This bias results in a focal-mechanism catalog that appears less heterogeneous than the underlying stress orientations. Comparison of synthetic focal-mechanism catalogs with catalogs of real earthquakes suggests that stress in the crust is heterogeneous. Stochastic parameters are estimated which generate distance dependent spatial variations in focal mechanisms similar to those reported by Hardebeck (2006) for southern California

Reply to "Comment on 'Models of Stochastic, Spatially Varying Stress in the Crust Compatible with Focal-Mechanism Data, and How Stress Inversions Can Be Biased toward the Stress Rate' by Deborah Elaine Smith and Thomas H. Heaton" by Jeanne L. Hardebeck

In her comment (Hardebeck, 2015) on our stress heterogeneity article (Smith and Heaton, 2011), Hardebeck suggests a different focal‐mechanism error distribution than what we used in our 2011 article and suggests that this new error distribution will reduce our estimates of stress heterogeneity. In response to this, we have rerun our calculations three ways: (1) with the original mechanism error distribution from Smith and Heaton (2011), (2) with a mechanism error distribution similar to the one presented by Hardebeck (2015), and (3) with a mechanism error distribution derived from repeating earthquake statistics. We find the two new mechanism error models, relative to the original mechanism error distribution, reduce the heterogeneity ratio (HR) estimates by approximately 35%–40% (using Hardebeck’s suggested distribution) and by approximately 8%–10% (using the repeating earthquake based error distribution)

Traditional uses and relative cultural importance of Tetragonula iridipennis (Smith) (Hymenoptera: Apidae: Meliponini) in Nepal

Indigenous and non-indigenous peoples in tropical and subtropical areas of the world use stingless bees for diverse purposes. Literature records indicate that people from different regions in Nepal use Tetragonula iridipennis (Smith), the only stingless bee species that occurs in the country. However, ethnobiological knowledge on this bee remains poorly documented. Herein we report for the first time on the local indigenous nomenclature, traditional knowledge, and management practices among four ethnic communities (Chhetri, Brahmin, Tharu, and Kirat) in Nepal. We also offer a preliminary quantitative analysis of the relative cultural importance of this species among these ethnic groups. We conducted ethnographic research across the Terai and Pahad regions (8 districts and 6 zones) of Nepal and recorded 18 specific uses in food, medicine, crafts, and religious beliefs. Based on the relative importance index, T. iridipennis is most culturally important for the Tharu people, a finding that supports the reliance of this ethnic group on local natural resources in their everyday life. All participant communities largely exploit this bee through extractive management practice of wild populations. We discuss the conservation status and future directions for the sustainable use of this stingless bee in the country

Resolved, Every Librarian a Subject Librarian: Implementing Subject Librarianship Across a Research Library

Many academic research librarians are specialists—catalogers, data curation librarians, electronic resources librarians—and working with students is considered to be a job for public service librarians. The University of Tennessee Libraries is expanding subject librarian responsibility across the Libraries, and research librarians who may have never worked in public services are assuming liaison and collection development roles. Steve Smith, Dean of Libraries, will share his model of learning, research, and collections (LRC) librarianship and explain his rationale for starting the University of Tennessee, Knoxville Libraries down this road. And how is that concept working for us? Hear from a couple of the librarians charged with implementing the vision: a technical services librarian given new LRC subject responsibility and the public service librarian assigned to get that new LRC subject librarian up to speed. We will discuss organizational and implementation challenges and share what we have learned about training and mentoring new subject librarians

Auditor liability and excess cash holdings: Evidence from audit fees of foreign incorporated firms

Auditors of foreign cross-listed firms face liability arising from the nature of the institutional monitoring framework of legal claims that can potentially be brought against the auditor in both the home country and the US. This paper is the first to document the relationship between auditor liability and auditor pricing of excess cash holdings for foreign firms cross-listed in the US. Our findings indicate that auditors demand a fee premium for foreign incorporated clients with greater excess cash holdings, consistent with auditors recognizing the potential for legal exposure to agency conflict arising from foreign listed US traded clients. Furthermore, we examine aspects of foreign capital market protections, such as disclosure requirements, the strength of legal enforcement, and the strength of shareholder rights to better understand auditor perception of the liability they incur due to the agency costs associated with excess cash holdings. We find that there is a significant positive association between audit fees and excess cash holdings for firms where the country of incorporation permits greater liability of auditors in criminal and civil litigation. In addition, auditors assign higher audit fees to firms holding greater excess cash incorporated in countries with greater required accounting disclosure, stronger legal enforcement and stronger shareholder rights

The alpha-synuclein 5'untranslated region targeted translation blockers: anti-alpha synuclein efficacy of cardiac glycosides and Posiphen

Increased brain α-synuclein (SNCA) protein expression resulting from gene duplication and triplication can cause a familial form of Parkinson's disease (PD). Dopaminergic neurons exhibit elevated iron levels that can accelerate toxic SNCA fibril formation. Examinations of human post mortem brain have shown that while mRNA levels for SNCA in PD have been shown to be either unchanged or decreased with respect to healthy controls, higher levels of insoluble protein occurs during PD progression. We show evidence that SNCA can be regulated via the 5'untranslated region (5'UTR) of its transcript, which we modeled to fold into a unique RNA stem loop with a CAGUGN apical loop similar to that encoded in the canonical iron-responsive element (IRE) of L- and H-ferritin mRNAs. The SNCA IRE-like stem loop spans the two exons that encode its 5'UTR, whereas, by contrast, the H-ferritin 5'UTR is encoded by a single first exon. We screened a library of 720 natural products (NPs) for their capacity to inhibit SNCA 5'UTR driven luciferase expression. This screen identified several classes of NPs, including the plant cardiac glycosides, mycophenolic acid (an immunosuppressant and Fe chelator), and, additionally, posiphen was identified to repress SNCA 5'UTR conferred translation. Western blotting confirmed that Posiphen and the cardiac glycoside, strophanthidine, selectively blocked SNCA expression (~1 μM IC(50)) in neural cells. For Posiphen this inhibition was accelerated in the presence of iron, thus providing a known APP-directed lead with potential for use as a SNCA blocker for PD therapy. These are candidate drugs with the potential to limit toxic SNCA expression in the brains of PD patients and animal models in vivo

Links between Anr and Quorum Sensing in Pseudomonas aeruginosa Biofilms

In Pseudomonas aeruginosa, the transcription factor Anr controls the cellular response to low oxygen or anoxia. Anr activity is high in oxygen-limited environments, including biofilms and populations associated with chronic infections, and Anr is necessary for persistence in a model of pulmonary infection. In this study, we characterized the Anr regulon in biofilm-grown cells at 1% oxygen in the laboratory strain PAO1 and in a quorum sensing (QS)-deficient clinical isolate, J215. As expected, transcripts related to denitrification, arginine fermentation, high-affinity cytochrome oxidases, and CupA fimbriae were lower in the Δanr derivatives. In addition, we observed that transcripts associated with quorum sensing regulation, iron acquisition and storage, type VI secretion, and the catabolism of aromatic compounds were also differentially expressed in the Δanr strains. Prior reports have shown that quorum sensing-defective mutants have higher levels of denitrification, and we found that multiple Anr-regulated processes, including denitrification, were strongly inversely proportional to quorum sensing in both transcriptional and protein-based assays. We also found that in LasR-defective strains but not their LasR-intact counterparts, Anr regulated the production of the 4-hydroxy-2-alkylquinolines, which play roles in quorum sensing and interspecies interactions. These data show that Anr was required for the expression of important metabolic pathways in low-oxygen biofilms, and they reveal an expanded and compensatory role for Anr in the regulation of virulence-related genes in quorum sensing mutants, such as those commonly isolated from infections