Miracle-dz/UniFAR-FTUs huggingface dataset:
Information Technology , Workplace Organization , and the Demand for Skilled Labor : Firm-level Evidence

We investigate the hypothesis that the combination of three related innovations, 1) information technology (IT), 2) complementary workplace reorganization, and 3) new products and services, constitute a significant skill-biased technical change affecting labor demand in the United States. Using detailed firm-level data, we find evidence of complementarities among all three of these innovations in factor demand and productivity regressions. In addition, firms that adopt one or more of these innovations tend to use more skilled labor. The effects of IT on labor demand are greater when IT is combined with the particular organizational investments we identify, highlighting the importance of IT-enabled organizational change. Timothy F. Bresnahan Erik Brynjolfsson Lorin M. Hitt Stanford University M.I. T. University of Pennsylvania Department of Economics 6072 Sloan School of Management Wharton School Landau Building, Serra Street 50 Memorial Drive, E53-313 1318 Steinberg Hall-Dietrich Hall Stanford, CA 94305-6072 Cambridge, MA 02142-1347 Philadelphia, PA 19104 timothy.bresnahan@stanford.edu erikb@mit.edu lhitt@wharton.upenn. edu
Amendment history : Corrigendum ( September 2015 ) Biomarkers on patient T cells diagnose active tuberculosis and monitor treatment response

BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection.
Health-hazard evaluation report HETA 91-152-2140, U. S. Department of the Interior, National Park Service, Southern California

In response to a request from the National Park Service, an evaluation was made of the health effects of forest fire smoke exposure among wild land fire fighters from the National Park Service and Forest Service (SIC-0851) in Southern California. A survey was performed to determine whether these workers incurred cross season changes in lung function and respiratory symptoms during the 1990 fire season. An estimated 80,000 wild land fire fighters fight approximately 70,000 forest fires that burn 2 million acres of forested land each year. In June of 1990 spirometry was performed and a questionnaire administered to 105 preseason participants to establish a preseason baseline. Post season data were collected during September of the same year on 78 of these individuals. Overall the mean cross season changes for lung function for the 78 participants were -0.5% in 1 second forced expiratory volume (FVC1), 0.2% in forced vital capacity (FVC), -2.3% in the mean forced expiratory flow during the middle half of the FVC (FEF25-75), and -0.5% in the ratio of FEV1 to FVC. Dose related decreases in FEF25-75 and FEV1/FVC were observed with higher exposures. No significant increase in the prevalence of respiratory symptoms was noted cross seasonally andmore » those which did occur were not associated with exposure. The authors conclude that there was limited evidence that forest fire fighting results in cross season changes in lung function. They recommend that a respiratory surveillance program be performed to examine the long term effects of forest fire fighting on lung function. « less
Finance and Economics Discussion Series Divisions of Research & Statistics and Monetary Affairs Federal Reserve Board , Washington ,

This paper provides an extensive analysis of the predictive ability of financial volatility measures for economic activity. We construct monthly measures of stock and bond market volatility from daily returns and model volatility as composed of a long-run component that is common across all series, and a set of idiosyncratic short-run components. Based on powerful in-sample predictive ability tests, we find that the stock volatility measures and the common factor significantly improve short-term forecasts of conventional financial indicators. A real-time out of sample assessment yields a similar conclusion under the assumption of noisy revisions in macroeconomic data. In a non-linear extension of the dynamic factor model for volatility series, we identify three regimes that describe the joint volatility dynamics: low, intermediate and high-volatility. We also find that the non-linear model performs remarkably well in tracking the Great Recession of 2007-2009 in realtime.
Zircon chronochemistry of high heat-producing granites in Queensland and Europe

High heat-producing granites (HHPGs) are reservoir rocks for enhanced geothermal systems (EGS), yet the origins of their anomalous chemistry remain poorly understood. To gain a better understanding of the characteristic distribution of elemental depletions and enrichments (focussing on U, Th & K) within granite suites of different heritage and tectonic setting, and the processes that lead to these enrichments, we are undertaking a systematic accessory-mineral chronochemical study of two suites of S- and I-type granites in northern Queensland, as well as two archetypal HHPGs in Cornwall, England (S-type) and Soultz-sous- Forets, France (I-type). Novel zircon LA-ICP-MS chronochemical methods will later be underpinned by a systematic petrographic, scanning electron microscope (SEM), and electron microprobe (EPMA) study of all the REE-Y-Th-U-rich accessory minerals to fully characterise how the composition, textural distributions and associations change with rock chemistry between and among the suites. Preliminary results indicate that zircons with inherited ages do not have anomalously high U (>1000 ppm) & Th (>400 ppm) values (Ahrens, 1965). Instead, enrichment in these HPE is seen in zircons dated to around the time of magmatic emplacement. These results indicate that enrichment arose primarily through fractional crystallisation of the granitic magmas. Our results support the suggestion that a source pre-enriched in the HPEs does not appear to be fundamental for the formation of all HHPGs. Instead fractional crystallisation processes, and the accessory minerals formed in magmas of differing initial compositions, are the key controls on the levels of enrichment observed (e.g. Champion & Chappell, 1992; Chappell & Hine, 2006). One implication is that the most fractionated granites may not be the most enriched in the HPEs and therefore prospective to future EGS development.
A New Weibull Class of Distributions: Theory, Characterizations and Applications

We propose a new class of continuous models called the Weibull Generalized G family with two extra positive shape parameters, which extends several well-known models. We obtain some of its mathematical properties including ordinary and incomplete moments, generating function, order statistics, probability weighted moments, entropies, residual, and reversed residual life functions. Characterizations based on a ratio of two truncated moments, in terms of hazard function and based on certain functions of the random variable are presented. We estimate the model parameters by the maximum likelihood method. We assess the performance of the maximum likelihood estimators in terms of biases and mean squared errors by means of two simulation studies. The usefulness of the proposed models is illustrated via three real data sets.
Homological algebra of Stanley-Reisner rings and modules

Homological algebra of Stanley–Reisner rings and modules Connor Sawaske Chair of the Supervisory Committee: Professor Isabella Novik Department of Mathematics Associated to each simplicial complex ∆ and each field k is the Stanley–Reisner ring k[∆]. The answers to a multitude of questions related to simplicial complexes have historically been found through a thorough examination of the algebraic structure of k[∆]. There is a rich pre-existing body of literature equating combinatorial and topological statements about the structure of a simplicial complex with statements about k[∆]; this dissertation expands upon the dictionary translating such statements by examining algebraic structures derived from k[∆]. In particular, we mainly focus on the local cohomology modules H i m(k[∆]) and the Ext modules Ext (k,k[∆]). Roughly speaking, a simplicial complex is called Buchsbaum if its geometric realization is similar to a manifold. In Chapter 2, we study the homological structure of k[∆] and some of its quotients by linear forms when ∆ fails to be Buchsbaum in a way that may be considered “minimal. ” We obtain a large family of rings with interesting combinations of the (ring-theoretic) properties of Buchsbaumness and quasi-Buchsbaumness, while developing a geometric interpretation of their presence. In Chapter 3, we turn our attention to complexes that exhibit some degree of symmetry via group actions. Here it is shown that the induced action on H i m(k[∆]) can be described in a similar manner to the one induced on the simplicial cohomology modules of ∆ and some of its subcomplexes. Some applications to the study of face numbers are provided. If the definition of a simplicial complex is slightly relaxed, then one arrives at the notion of a simplicial poset. Chapter 4 is devoted to the study of these objects and their associated face rings. We provide extensions of well-known results describing the structure of the Ext and local cohomology modules of simplicial complexes to this larger class and further examine the Buchsbaum property. In Chapter 5, we study the class of balanced triangulations of manifolds and obtain lower bounds on entries in the h-vector phrased in terms of topological invariants. This proves a conjecture of Klee and Novik.
Relapse Prevention: Overview of Research Findings in the Treatment of Problem Drinking, Smoking, Obesity and Depression

The aim of this paper is to provide an overview of developments in the area of relapse prevention for selected psychological disorders: problem drinking; smoking; obesity; and depression. Relapse prevention methods, including booster sessions, have been associated with mixed outcomes, although there are some encouraging findings, particularly in the treatment of obesity and alcohol problems. A number of recommendations are made for research and/or clinical practice. In the treatment of alcohol problems it is recommended that more attention be paid to reducing co-existent marital problems and mood disorders. In obesity, there is a need for evaluations of intensive, long-term therapist contact with the severely obese, particularly those with serious medical problems. Studies of the complete relapse prevention approach advocated by Marlatt and Gordon (1985) are needed in the evaluation of smoking cessation programmes. It is concluded that maintenance of gains in smoking, obesity and problem drinking comes at a considerable cost in time and therapist contact. To date, there has been little application of relapse prevention methods to depression, and further empirical work is needed to identify the determinants of relapse and the efficacy of specific maintenance-enhancement strategies. Consistent themes in the prediction of relapse are identified, including low social support, ongoing interpersonal difficulties, and low self-efficacy.
Growth and yield of lentil (Lens culinaris L.) as affected by boron and molybdenum application in lateritic soil.

Field experiments were conducted during winter seasons of 2004-05 and 2005-06 at the RRSS, Sekahmpur, BCKV, to study the effect of B and Mo to the growth, and yield of lentil grown on inherently poor lateritic soil. The lentil (cv. B77) was raised with application of B and Mo either separately or in mixture through foliage or to soil along with NPK fertilizers. The leaf area index, above ground dry matter and crop growth rate increased with the application of B and Mo. Soil application of B coupled with foliar application of Mo enhanced the yield attributing characters and yield of the lentil crop. The study indicated that growing of lentil in lateritic soils depleted the nutrients particularly micronutrients which resulted in loss of yield and could be recovered, if the relevant micronutrients are supplemented through appropriate application methods and dosage.
A Technique for Evaluating the Uncertainties in Path Loss Predictions Caused by Sparsely Sampled Terrain Data

Abstract : Radio propagation models provide an estimate of the power loss in a communication link caused by the surface of the ground, atmospheric refraction, foliage, and other environmental factors. Many of the models rely on digital topographic databases to provide information about the terrain, and generally the databases are sparsely sampled relative to the electromagnetic wavelengths used for communication systems. This work primarily develops a technique to evaluate the effects of that sparsity on the uncertainty of propagation models. That is accomplished by accurately solving the electromagnetic fields over many randomly rough surfaces which pass through the sparse topographic data points, many possible communication links, all of which fit the underlying data, are represented. The power variation caused by the different surface realizations is that due to the sparse sampling. Additionally, to verify that this solution technique is a good model, experimental propagation measurements were taken, and compared to the computations.
The View From the Top: Academic Emergency Department Chairs’ Perspectives on Education Scholarship

Education scholarship continues to grow within emergency medicine (EM) and in academic medicine in general. Despite a growing interest, would‐be education scholars often struggle to find adequate mentorship, research training, funding, and protected time to produce rigorous scholarship. The ways in which individual academic EM departments can support this mission remains an area in need of description.
The modelisation of constrained damping layer treatments using the finite element method: spatial model and viscoelastic behaviour

Surface and integrated damping treatments with viscoelastic layers play an important position among the passive damping treatments for light and flexible structures under vibration. Application simplicity, low cost, reduced structural modification and reduced additional mass, along with an inherent high efficiency, are the main reasons of it successful usage. However, the design process of these treatments is not simple and requires a reliable tool for adequate designing and analysis. The finite element method can be used for this purpose. However some considerations and special care are necessary to the spatial modelisation of the treatment and with the viscoelastic material properties characterisation. In this work, a finite element commercial software (MSC/Nastran) was used to simulate the constrained and the integrated viscoelastic treatments applied on aluminium plates. The spatial modeling of the treatment is developed using a layered scheme of plate/brick conventional finite elements. The dynamic properties of the viscoelastic material are taken into account in the numerical simulation using the complex modulus approach. The numerical results are correlated with experimental data obtained in four treated specimens by direct comparison of the frequency response functions and by using some FRF-based correlation indicators.
Phyllotaxis

The precise arrangement of plant organs, also called phyllotaxis, has fascinated scientists from multiple disciplines. Whereas early work focused on morphological observations of phyllotaxis, recent findings have started to reveal the mechanisms behind this process, showing how molecular regulation and biochemical gradients interact with physical components to generate such precise patterns of growth. Here, I review new insights into the regulation of phyllotactic patterning and provide an overview of the various factors that can drive these robust growth patterns.
Recombinant Protein-Based Enzyme-Linked Immunosorbent Assay and Immunochromatographic Tests for Detection of Immunoglobulin G Antibodies to Severe Acute Respiratory Syndrome (SARS) Coronavirus in SARS Patients

ABSTRACT An enzyme-linked immunosorbent assay (ELISA) and a rapid immunochromatographic test for detection of immunoglobulin G (IgG) antibodies in severe acute respiratory syndrome (SARS) patients were developed by utilizing the well-characterized recombinant proteins Gst-N and Gst-U274. The ELISA detected IgG antibodies to SARS-CoV in all 74 convalescent-phase samples from SARS patients while weakly cross-reacting to only 1 of the 210 control sera from healthy donors. This finding thus led to a kit sensitivity, specificity, and accuracy of 100, 99.5, and 99.6%, respectively. The test thus provided a positive predictive value (PPV) of 98.7% and a negative predictive value (NPV) of 100%. In addition, the ELISA gave a positive delta of 5.4 and a negative delta of 3.6, indicating an excellent differentiation between positives and negatives. The same recombinant proteins were also applied to a newly developed platform for the development of a 15-min rapid test. The resulting rapid test has an excellent agreement of 99.6%, with a kappa value of 1.00, with the ELISA. Again, this rapid test was able to detect 100% of the samples tested (n = 42) while maintaining a specificity of 99.0% (n = 210). The PPV and NPV for the rapid test thus reached 95.3 and 100%, respectively.
Environment and Foreign Direct Investment: Policy Implications for Developing Countries

There is a two-way relationship between foreign direct investment (FDI) and environment that may have negative or positive effects on welfare. However, FDIenvironment relationship is controversial and needs further investigation. To this end, the present research work uses a dynamic panel model to assess the effect of FDI inflows on pollution emissions in developing countries. Three equations are examined empirically. This is to assess the effect of FDI inflows in developing countries on carbon dioxide, energy use and biochemical oxygen demand (BOD) emissions level. A fixed effect panel data model with heterogonous slopes is used to account for differences within countries. The model is estimated using the error correction approach. In addition, the direction of the relationship between FDI flows and environment is studied using Granger causality test. The empirical results do not settle the FDI-environment debate and suggest focusing the analysis on individual county basis. Conclusions and policy implications for developing countries are also given. Policy implications highlight the importance of using effective policies to reduce pollution emissions and to regulate FDI-environment relationship.
The Supply-Side Determinants of Loan Contract Strictness

Using a novel measure of contract strictness based on the ex-ante probability of a covenant violation, I investigate how lender-specific shocks impact the strictness of the loan contract that a borrower receives. Exploiting between-bank variation in recent portfolio performance, I find evidence that banks write tighter contracts than their peers after suffering payment defaults to their own loan portfolios, even when defaulting borrowers are in different industries and geographic regions than the current borrower. The effects of recent defaults persist after controlling for bank capitalization, although compression in bank equity is also strongly associated with tighter contracts. The evidence is most consistent with lenders using their default experience to make inference about their screening ability and adjusting contracts accordingly. Finally, contract tightening is most pronounced for borrowers who are dependent on a relatively small circle of lenders, with a one standard deviation increase in lender defaults implying covenant tightening nearly equivalent to that of a two-notch downgrade in the borrower's own credit rating.
The Economic Impact of Merger Control Legislation

We investigate the impact of legislative reforms in merger control legislation in nineteen industrial countries between 1987 and 2004. We find that strengthening merger control decreases the stock prices of non-financial firms, while increasing those of banks. Cross sectional regressions show that the discretion embedded in the supervisory control of bank mergers is a major determinant of the positive bank stock returns. One explanation is that merger control introduces “checks and balances” that mitigates the potential abuse and wasteful enforcement of supervisory control in the banking sector.
The Information Content of Option-Implied Volatility for Credit Default Swap Valuation

Credit default swaps (CDS) are similar to out-of-the-money put options in that both offer a low cost and effective protection against downside risk. This study investigates whether put option-implied volatility is an important determinant of CDS spreads. Using a large sample of firms with both CDS and options data, we find that individual firms' put option-implied volatility dominates historical volatility in explaining the time-series variation in CDS spreads. To understand this result, we show that implied volatility is a more efficient forecast for future realized volatility than historical volatility. More importantly, the volatility risk premium embedded in option prices covaries with the CDS spread. These findings complement existing empirical evidence based on market-level data.
Panel LM Unit Root Tests with Trend Shifts

This paper proposes a new Lagrange multiplier (LM) based unit root test for panel data allowing for heterogeneous structural breaks in both the intercept and slope of each cross-section unit in the panel. We note that panel unit root tests allowing for breaks in the slope will critically depend on the nuisance parameters indicating the size and location of breaks. Any panel tests that ignore this dependency on the nuisance parameter will be subject to serious size distortions. To address this problem, our test employs a method that renders the asymptotic distribution of the panel tests invariant to nuisance parameters. We derive the asymptotic properties of our test and also examine its finite-sample properties. In addition, our test easily can be modified to correct for the presence of cross-correlations in the innovations of the panel. We illustrate this by applying the cross-sectionally augmented ADF (CADF) procedure of Pesaran (2007) to our test statistic.
Idiosyncratic shocks and the role of nonconvexities in plant and aggregate investment dynamics

We solve equilibrium models of lumpy investment wherein establishments face persistent shocks to common and plant-specific productivity. Nonconvex adjustment costs lead plants to pursue generalized (S,s) decision rules with respect to capital; as a result, their individual investments are lumpy. In partial equilibrium, this yields substantial skewness and kurtosis in aggregate investment, though, with differences in plant-level productivity, these nonlinearities are far less pronounced. Moreover, nonconvex costs, like quadratic adjustment costs, greatly increase the persistence of aggregate investment rates, yielding a better match with the data. In general equilibrium, aggregate nonlinearities disappear, and investment rates are very persistent, regardless of capital adjustment costs. While the aggregate implications of lumpy investment change substantially in equilibrium, the inclusion of fixed costs or idiosyncratic shocks yields an average distribution of plant investment rates that, in contrast, is largely unaffected by market-clearing movements in real wages and interest rates. Nonetheless, we find that to understand the dynamics of plant-level investment requires general equilibrium analysis. JEL Codes: E22, E32.