Negative social media sentiment from state and local officials could be bad for local government finances

Social media sentiment has become a powerful force across most aspects of society, and state and local government is no exception. In new research, Justin Marlowe tracks the social media output of state and local finance officials from 2014 to 2020, finding that their sentiment became more negative following the onset of the COVID-19 pandemic. He writes that these negative sentiments could lead to real consequences for local government finances

Tuberculosis diagnostics and biomarkers: needs, challenges, recent advances, and opportunities

Tuberculosis is unique among the major infectious diseases in that it lacks accurate rapid point-of-care diagnostic tests. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely fashion, allowing continued Mycobacterium tuberculosis transmission within communities. Currently recommended gold-standard diagnostic tests for tuberculosis are laboratory based, and multiple investigations may be necessary over a period of weeks or months before a diagnosis is made. Several new diagnostic tests have recently become available for detecting active tuberculosis disease, screening for latent M. tuberculosis infection, and identifying drug-resistant strains of M. tuberculosis. However, progress toward a robust point-of-care test has been limited, and novel biomarker discovery remains challenging. In the absence of effective prevention strategies, high rates of early case detection and subsequent cure are required for global tuberculosis control. Early case detection is dependent on test accuracy, accessibility, cost, and complexity, but also depends on the political will and funder investment to deliver optimal, sustainable care to those worst affected by the tuberculosis and human immunodeficiency virus epidemics. This review highlights unanswered questions, challenges, recent advances, unresolved operational and technical issues, needs, and opportunities related to tuberculosis diagnostics

Rapid and Accurate Detection of Mycobacterium tuberculosis in Sputum Samples by Cepheid Xpert MTB/RIF Assay-A Clinical Validation Study

Background: A crucial impediment to global tuberculosis control is the lack of an accurate, rapid diagnostic test for detection of patients with active TB. A new, rapid diagnostic method, (Cepheid) Xpert MTB/RIF Assay, is an automated sample preparation and real-time PCR instrument, which was shown to have good potential as an alternative to current reference standard sputum microscopy and culture.Methods: We performed a clinical validation study on diagnostic accuracy of the Xpert MTB/RIF Assay in a TB and HIV endemic setting. Sputum samples from 292 consecutively enrolled adults from Mbeya, Tanzania, with suspected TB were subject to analysis by the Xpert MTB/RIF Assay. The diagnostic performance of Xpert MTB/RIF Assay was compared to standard sputum smear microscopy and culture. Confirmed Mycobacterium tuberculosis in a positive culture was used as a reference standard for TB diagnosis.Results: Xpert MTB/RIF Assay achieved 88.4% (95% CI = 78.4% to 94.9%) sensitivity among patients with a positive culture and 99% (95% CI = 94.7% to 100.0%) specificity in patients who had no TB. HIV status did not affect test performance in 172 HIV-infected patients (58.9% of all participants). Seven additional cases (9.1% of 77) were detected by Xpert MTB/RIF Assay among the group of patients with clinical TB who were culture negative. Within 45 sputum samples which grew non-tuberculous mycobacteria the assay's specificity was 97.8% (95% CI = 88.2% to 99.9%).Conclusions: The Xpert MTB/RIF Assay is a highly sensitive, specific and rapid method for diagnosing TB which has potential to complement the current reference standard of TB diagnostics and increase its overall sensitivity. Its usefulness in detecting sputum smear and culture negative patients needs further study. Further evaluation in high burden TB and HIV areas under programmatic health care settings to ascertain applicability, cost-effectiveness, robustness and local acceptance are required

Mechanical Properties of Plant Underground Storage Organs and Implications for Dietary Models of Early Hominins

The diet of early human ancestors has received renewed theoretical interest since the discovery of elevated d13C values in the enamel of Australopithecus africanus and Paranthropus robustus. As a result, the hominin diet is hypothesized to have included C4 grass or the tissues of animals which themselves consumed C4 grass. On mechanical grounds, such a diet is incompatible with the dental morphology and dental microwear of early hominins. Most inferences, particularly for Paranthropus, favor a diet of hard or mechanically resistant foods. This discrepancy has invigorated the longstanding hypothesis that hominins consumed plant underground storage organs (USOs). Plant USOs are attractive candidate foods because many bulbous grasses and cormous sedges use C4 photosynthesis. Yet mechanical data for USOs—or any putative hominin food—are scarcely known. To fill this empirical void we measured the mechanical properties of USOs from 98 plant species from across sub-Saharan Africa. We found that rhizomes were the most resistant to deformation and fracture, followed by tubers, corms, and bulbs. An important result of this study is that corms exhibited low toughness values (mean = 265.0 J m-2) and relatively high Young’s modulus values (mean = 4.9 MPa). This combination of properties fits many descriptions of the hominin diet as consisting of hard-brittle objects. When compared to corms, bulbs are tougher (mean = 325.0 J m-2) and less stiff (mean = 2.5 MPa). Again, this combination of traits resembles dietary inferences, especially for Australopithecus, which is predicted to have consumed soft-tough foods. Lastly, we observed the roasting behavior of Hadza hunter-gatherers and measured the effects of roasting on the toughness on undomesticated tubers. Our results support assumptions that roasting lessens the work of mastication, and, by inference, the cost of digestion. Together these findings provide the first mechanical basis for discussing the adaptive advantages of roasting tubers and the plausibility of USOs in the diet of early hominins

Characterization and Consequences of Atomic-Scale Catalyst Structure on Performance for Hydrodeoxygenation of Lignin Model Compounds

A variety of technical, economic, and societal factors require a global shift in the consumption of goods and the production of energy towards routes that are broadly more sustainable. A shift toward the use of biomass as a feedstock for carbon-based chemicals is one promising component of such a future shift, spurred on recently by rapid electrification of transportation and energy sectors. Lignin, a component of biomass that is currently underutilized as waste generated during cellulose production, represents a promising, drop-in replacement for current carbon feedstocks such as petroleum for the production of aromatic monomers such as benzene, toluene, and xylene (BTX). This route of lignin-to-chemicals would, in principle, provide a net-zero carbon emissions source of these high-value chemicals currently produced on the scale of hundreds of millions of tons annually across the globe. However, one of the primary technical challenges preventing the adoption of such a process is the removal of oxygen from lignin-derived monomers through catalytic hydrodeoxygenation (HDO). Oxygenated lignin monomers provide a range of reactive functionalities that are activated by the catalysts typically explored to date, namely supported transition metal nanoparticles. Thus, high selectivity of catalyst activation towards solely C-O bonds is essential to avoid off-target product formation. Recently, a class of catalysts involving noble metal-reducible metal oxide interactions has been identified as promising for the HDO of lignin-derived compounds. Despite initial reports of high selectivity for C-O bond cleavage over other competing reactions such as aromatic ring hydrogenation, there remains a lack of fundamental understanding of the active site, hampered primarily by vast uncertainty regarding the mechanism of deoxygenation, the structure of the catalysts under reaction conditions, and the subsequent structure-activity relationships. While it is generally known that the reduced oxide decorates the metal nanoparticle surfaces, it is unclear whether or not the oxide participates directly in catalysis either as the active site itself, a modifier to the base metal reactivity, or solely as a spectator or inhibitor. Because of this uncertainty, a number of plausible mechanisms have been proposed, including direct deoxygenation, acid-catalyzed dehydration, and Mars-van Krevelen-type deoxygenation, among others. This work contained within this dissertation seeks to clarify the role of the reducible metal oxide as it pertains to HDO catalysis, specifically, but also to expound upon the understanding of metal-oxide interactions more broadly, especially concerning the so-called strong metal-support interaction (SMSI). The development of a model catalyst system with high tunability which facilitates a number of different characterization techniques to probe catalyst structure and develop structure-activity relationship is critical to this goal. Through this developed catalyst framework, this dissertation explores the effects on HDO catalysis of nanoparticle size (Chapter 2), the metal oxide surface density (Chapter 3), metal oxide identity (Chapter 4), and support identity (Chapter 5).Through a combination of in situ and ex-situ characterization techniques (DRIFTS, TEM, chemisorption) and measured reactivity of diverse model compounds for lignin, the role of MOx promotion of Pt in HDO is clarified. MOx decoration on the surfaces of metal sites serves primarily as a site-blocker, selectively inhibiting the undesired aromatic hydrogenation by limiting the number of metal ensembles large enough to facilitate planar aromatic adsorption through the preferential decoration of these ensembles. However, the oxide-metal interface formed during catalysis also plays a lesser role in facilitating deoxygenation through the conversion of metastable surface intermediates. The results suggest that both modified and unmodified Pt catalysts transit through a shared mechanism in the HDO of phenolics, with tautomerization of the phenolic functionality being an essential characteristic to facilitate deoxygenation under the conditions studied

Hofferbert in Transit: A Dynamic Stages Model of the Urban Policy Process

This article presents a reformulation and empirical test of Hofferbert's (1974) "stages" heuristic, a model that fell largely out of favor due to criticisms that it does not effectively account for (1) feedback loops, or the possibility that policymakers learn from past experiences, and (2) the importance of intergovernmental relations. We update this model and apply it in the context of urban transit policymaking, using revenue flows to and from the government as an indicator of both recursive behavior and intergovernmental influence. The results suggest that these modifications reestablish the explanatory power of the stages model. Copyright 2006 by The Policy Studies Organization.