Miracle-dz/UniFAR-FTUs huggingface dataset:
Nitrogen emission and deposition budget in West and Central Africa

Atmospheric nitrogen depends on land surface exchanges of nitrogen compounds. In Sub Saharan Africa, deposition and emission fluxes of nitrogen compounds are poorly quantified, and are likely to increase in the near future due to land use change and anthropogenic pressure. This work proposes an estimate of atmospheric N compounds budget in West and Central Africa, along an ecosystem transect, from dry savanna to wet savanna and forest, for years 2000−2007. The budget may be considered as a one point in time budget, to be included in long term studies as one of the first reference point for Sub Saharan Africa. Gaseous dry deposition fluxes are estimated by considering N compounds concentrations measured in the frame of the IDAF network (IGAC/DEBITS/AFrica) at the monthly scale and modeling of deposition velocities at the IDAF sites, taking into account the bi directional exchange of ammonia. Particulate dry deposition fluxes are calculated using the same inferential method. Wet deposition fluxes are calculated from measurements of ammonium and nitrate chemical content in precipitations at the IDAF sites combined with the annual rainfall amount. In terms of emission, biogenic NO emissions are simulated at each IDAF site with a surface model coupled to an emission module elaborated from an artificial neural network equation. Ammonia emissions from volatilization are calculated from literature data on livestock quantity in each country and N content in manure. NOx and NH3 emission from biomass burning and domestic fires are estimated from satellite data and emission factors. The total budget shows that emission sources of nitrogen compounds are in equilibrium with deposition fluxes in dry and wet savannas, with respectively 7.40 (±1.90) deposited and 9.01 (±3.44) kgN ha−1 yr−1 emitted in dry savanna, 8.38 (±2.04) kgN ha−1 yr−1 deposited and 9.60 (±0.69) kgN ha−1 yr−1 emitted in wet savanna. In forested ecosystems, the total budget is dominated by wet plus dry deposition processes (14.75 ± 2.36 kgN ha−1 yr−1), compared to emissions processes (8.54 ± 0.50 kgN ha−1 yr−1).
Essays on the Teachers' Labor Market

The four chapters are organized in chronological order as my research interests have developed. Chapter 1 begins with the motivation of my study in teachers’ labor market. I employ a monopolistic screening model to show that there exist multiple equilibria in the educational system; a pooling equilibrium and a separating equilibrium. The model predicts that the pooling equilibrium is optimal only when the average quality of teacher applicants is high. Using data from the OECD, I examine the relation between teachers’ earnings and teacher quality of the U.S. and Korea. Chapter 2 focuses on teachers and their career dynamics, and the data is at teacher level. Using the Current Population Survey for 2001-2010, I show that public school teachers are paid less compared to other comparable college graduates in non-teaching sectors. By studying the change in earnings after career changes, I find the evidence of positive selection when teachers move into the non-teaching sectors and of negative selection when nonDissertation Advisor: Richard Freeman Eunice Sookyung Han iv teachers move into the teaching sector, which results in the decrease in the average teacher quality. Chapter 3 looks at both teachers and school districts, and I use district-teacher matched dataset, based on the School and Staffing Survey (SASS) for 2007-2008. I employ a multilevel model and a propensity score matching to identify union effects in states with different legal environments for collective bargaining of teachers. I find that collective bargaining is neither necessary nor sufficient for unions to affect teachers’ well-being. I show that meet-and-confer is a popular alternative to collective bargaining and that it is an important mechanism for unions to influence teachers’ non-wage benefits. Chapter 4 concerns school districts, and I use SASS district level data. I reevaluate the role of teachers unions on pay structure and districts’ financial status. In contrasts to previous findings, I find that the variance of teachers’ earnings is higher in more unionized settings. Moreover, I show that the financial status of districts with teachers unions is stronger than that of districts without the unions. I confirm that unionism is associated with less usage of performance pay system.
THE EL NINO SOUTHERN OSCILLATION, VARIABLE FRUIT PRODUCTION, AND FAMINE IN A TROPICAL FOREST

We tested the hypothesis that the El Nino Southern Oscillation influences forest-wide fruit production, which, in turn, limits frugivorous and granivorous mammals on Barro Colorado Island (BCI), Panama. Observations of BCI mammals have been compiled for 49 years. Frugivorous mammals experienced famine between September and January in 1931–1932, 1958–1959, 1970–1971, and 1993–1994. The most recent famine is evident from an 11-yr record of natural deaths of mammals and a 2-yr record of population densities. Famine occurred every time a mild dry season followed an El Nino event in the 49-yr record. This coincidence is statistically improbable, as demonstrated by a randomization test. A 2-yr cycle of high, then low community-level fruit production has been observed twice for BCI when a mild dry season followed an El Nino event. We used 260 litter traps to monitor community- and species-level fruit production from 1 January 1987 through 30 June 1996. Community-level fruit production was greatest during the 199.
Do Firms Use the Deferred Tax Asset Valuation Allowance to Manage Earnings?

This study utilizes a sample comprised of Fortune 500 firms to examine earnings management via changes in the deferred tax asset valuation allowance. The study extends existing research in three ways. First, we document that the earnings effect of a valuation allowance change often cannot be determined from financial statement disclosures. Based on an analysis of sample firms' income tax footnotes, we offer suggestions to improve disclosure policy. Second, prior research uses the net change in the valuation allowance account as a proxy for the earnings effect of valuation allowance changes. We argue that the amount reported in the effective tax rate reconciliation is a better measure of the income statement effect and document certain significant differences between the measures. Third, prior research employs cross‐sectional regression models in an effort to make generalizations about earnings management behavior. In contrast, we use a contextual approach to assess whether observed valuation allowance cha.
Brief report: Reducing inappropriate usage of stress ulcer prophylaxis among internal medicine residents

AbstractBACKGROUND: Many inpatients receive stress ulcer prophylaxis (SUP) inappropriately. This indiscriminate usage increases costs and avoidable side-effects. Practice-based learning and improvement (PBLI) methodology may improve compliance with published guidelines. OBJECTIVE: To investigate the response of internal medicine residents to an educational intervention regarding SUP. DESIGN: A prospective, pre and postintervention cohort study using an educational intervention based on PBLI. PATIENTS: Three groups of consecutively admitted patients (1 group preintervention and 2 groups postintervention) on the medicine ward at a University Hospital. MAIN OUTCOME MEASURE: Rates of inappropriate SUP prescription and discharge with an inappropriate prescription. RESULTS: One month after the intervention, inappropriate prophylaxis was significantly decreased (59% pre, 29% postintervention, P<.002). The rate of discharge with an inappropriate prescription also decreased, but was not significant (25% pre, 14% postintervention, P=.14). In the 6-month postintervention cohort, inappropriate SUP remained lower (59% pre, 33% postintervention, P<.007). The rate of discharge with an inappropriate prescription was also significantly lower (25% pre, 7% postintervention, P<.009). CONCLUSION: Practice-based learning and improvement can improve compliance with published guidelines, and change practice patterns. After the intervention, both inappropriate prophylaxis and inappropriate prescriptions upon discharge were reduced. Importantly, the intervention was sustained, transmitted across academic years to a new class of interns who had not directly experienced the intervention.
Intertemporal production and asset pricing: a duality approach

This paper analyzes a firm's intertemporal optimization problem under uncertainty and presents a new asset pricing model from the vantage point of the production side of the economy using the duality principle. The intertemporal profit-maximization problem is formulated using the familiar cost function, and the production Euler equation that encapsulates the joint behavior of production and asset returns is derived. An asset's risk is measured by its covariance with the stochastic discount factor represented by the ratio of discounted marginal costs. The risk premium is determined by the conditional covariances of asset returns with output growth scaled by the degree of scale economies and with input price changes weighted by the cost share of an input. The proposed model has the standard structure of a multibeta pricing model and suggests four economic risk factors--output growth, the return on human capital, the return on physical capital, and technology shocks--for use in empirical analysis. Copyright 2003, Oxford University Press.
Energy Abundance, Trade and Specialization

Abstract Do countries with large energy endowments have larger energy-intensive sectors? We answer this question empirically using a panel with 14 high-income countries from Europe, America and Asia and 10 broad sectors, from 1970 to 1997. Energy-abundant countries have 7 to 10 percent higher employment and 13 to 17 percent higher net exports per value added in energy-intensive sectors vis-a-vis otherwise comparable countries. Conversely, energy-scarce countries specialize in non-energy-intensive sectors.
Coronary stenting with M-Guard: feasibility and safety porcine trial.

UNLABELLED M-Guard is an ultra-thin polymer mesh sleeve attached to the external stent surface. It is designed to minimize distal embolization during coronary, renal, carotid and vein graft stenting. The polymer net could also serve as a platform for more uniform drug delivery. AIM To evaluate coronary M-Guard stent deliverability and safety (stent thrombosis and restenosis) in comparison to bare-metal stents (BMS) in a porcine model of percutaneous coronary interventions (PCIs). METHODS Under general anesthesia using percutaneous technique, 6 swine received a total of 18 coronary stents: 5 BMS and 13 M-Guard-BMS. Quantitative coronary angiography (QCA) was obtained immediately prior to and post-PCI, and at 30 days post-stenting. At 30 days, all animals were sacrificed and hearts were sent to a core lab for coronary histology and histomorphometry. Primary endpoints were 30-day QCA percent diameter stenosis, late luminal loss and minimal luminal diameter (MLD). Secondary endpoints were procedural success, 30-day mortality and stent thrombosis. Exploratory endpoints were histology and histomorphometric analysis performed at 30 days on M-Guard stented segments. RESULTS All stents were delivered successfully. There were no procedural complications or porcine morbidity or mortality at 30 days. The M-Guard and BMS displayed similar results of MLD, late luminal loss and percent diameter stenosis at 1 month. CONCLUSION When compared to BMS, PCI with M-Guard-BMS is feasible, safe and yields similar inflammatory and restenotic response.
The ‘imagined West’ of young independent travellers from Asia

Abstract Although independent travel has become increasingly popular amongst young Asians in recent years, little research has been done to explore this segment. This study examines how young Asians construct the concept of an ‘imagined West’ from their travel. Data were collected through 31 in-depth interviews with young Asian independent travellers in Australia and Vietnam and informal conversations and observations recorded in field notes. The findings of the study suggest that young Asian independent travellers' imagination of the West encompasses a desire to experience Western cosmopolitanism and a motivation to accumulate cultural capital for personal development. The study contributes to the literature of Asian travel by highlighting the diversity of the ‘imagined West’ in relation to socio-cultural backgrounds of young Asian independent travellers.
Participation in Types of Physical Activities Among US Adults--National Health and Nutrition Examination Survey 1999-2006.

BACKGROUND Information on specific types of physical activities in which US adults participate is important for community and program development to promote physical activity. METHODS Prevalence of participation and average time spent for 33 leisure-time aerobic activities and 10 activity categories were calculated using self-reported data from 22,545 participants aged ≥ 18 years in the National Health and Nutrition Examination Survey 1999-2006. RESULTS Overall, 38% of US adults reported no leisure-time physical activities, and 43% reported 1 or 2 activities in the past 30 days. Walking was the most frequently reported activity for both men (29%) and women (38%). Among walkers, the average time spent walking was 198 minutes/week for men and 152 minutes/week for women. The most reported activities for men after walking were bicycling and yard work, and for women were aerobics and dance. For most activity categories, participation was lower among adults aged ≥ 65 years than among younger adults, and among Mexican Americans and non-Hispanic blacks than among non-Hispanic whites. Participation in most categories increased with increasing educational attainment. CONCLUSIONS Participation in physical activity differs by types of activities and demographic characteristics. Physical activity promotion programs should take these differences into account when developing intervention strategies.
Simulation Framework for a 3-D High-Resolution Imaging Radar at 300 GHz with a Scattering Model Based on Rendering Techniques

We present a simulation framework for a 3-D high-resolution imaging radar at 300 GHz with mechanical scanning. This tool allows us to reproduce the imaging capabilities of the radar in different setups and with different targets. The simulations are based on a ray-tracing approximation combined with a bidirectional reflectance distribution function (BRDF) model for the scattering of rough surfaces. Moreover, we present a novel approach to estimate the scattering parameters of the BRDF model for different types of targets from the combination of the radar data and information obtained from an infrared structure light sensor. This new framework will serve as a baseline for the design of future radar multistatic configurations and to generate synthetic data to train automatic target recognition algorithms.
Monitoring of Thiopurine Metabolites in Patients With Inflammatory Bowel Disease-What Is Actually Measured?

Azathioprine and 6-mercaptopurine are often used in the treatment of patients with inflammatory bowel disease (IBD). They are prodrugs and undergo a complex metabolism to active and inactive metabolites. Thiopurine treatment is monitored in many laboratories by measuring metabolite concentrations in erythrocytes (red blood cells). The metabolites of interest are not measured directly but as hydrolysis products, which can be produced from several metabolites. The aim of this study was to examine which metabolites are actually measured during routine monitoring. Samples from 18 patients treated with a thiopurine were analyzed by a typical routine high-performance liquid chromatography method for therapeutic drug monitoring and by a newly developed specific method measuring thioguanosine monophosphate (TGMP), thioguanosine diphosphate (TGDP), and thioguanosine triphosphate (TGTP), as well as methylthioinosine monophosphate (meTIMP), and the results were compared. 6-Thioguanine nucleotide (TGN) values detected by the routine method were 69% (range 40%-90%) of the sum of TGMP, TGDP, and TGTP measured by the specific method. TGTP and TGDP contributed 85% (range 78%-90%) and 14% (range 10%-21%) of the TGN total, respectively. Thioguanosine was not found in any patient sample. The concentration of meTIMP obtained by the routine method was 548% of the value obtained by the specific method (range 340%-718%). The difference in TGN measurements between the routine and specific methods can be explained by low hydrolysis efficiency in the routine method, although the most likely explanation for the difference in meTIMP values is that not yet identified metabolites are codetermined in the routine high-performance liquid chromatography method. Concentrations reported as TGN during therapeutic drug monitoring of thiopurine metabolites consist of TGDP and TGTP with a minor contribution of the TGMP. Concentrations reported as meTIMP or methyl mercaptopurine consist in part of meTIMP, but other not yet identified metabolites are codetermined.
A Spatial and Temporal Approach to Microevolutionary Forces Affecting Population Biology in the Freshwater Snail Biomphalaria pfeifferi

The limitations of both population demography and genetics highlight the need to combine these approaches when inferring the influence of demographic processes and modes of migration on genetic structure. The aim of this study was to use spatiotemporal genetic and demographic surveys to reveal the microevolutionary forces acting on the metapopulation dynamics of the freshwater snail Biomphalaria pfeifferi. We also analyzed the consequences of population turnover on temporal genetic differentiation, an aspect that has been little explored. Genetic drift was revealed by both the demographic survey, which indicated severe bottlenecks or extinction during the rainy (resp. dry) season in open (resp. closed) habitats, and the genetic approach, which indicated high selfing rates and strong temporal differentiation. Genetic reassignments and temporal differentiation both confirmed the results of the demographic survey, which suggests that migration occurs in closed (resp. open) habitats during the hot and dry (resp. rainy) season, and indicated that source‐sink functioning may be envisaged. A propagule pool mode of colonization was inferred in the open habitats during the rainy season and a migrant pool in the closed habitats during the dry season. Our study also suggests that selection might be inferred from patterns of neutral genetic markers when recombination is limited.
A Note on Strategic Delegation: The Role of Decreasing Returns to Scale

We build a model of optimal design of managerial incentive schemes when the production technology exhibits decreasing returns to scale and firms compete a la Cournot. We borrow Fershtman and Judd (1987) and Krakel (2005) framework. We show how there is a dominant strategy for entrepreneurs to delegate output decisions. Results depend on the degree of diseconomies of scale. We demostrate how for a class of parameters, managers may increase profits through delegation, a result that with constant returns does not hold.
Understanding the domain of counterproductive work behaviour in China

Current conceptualizations of employee job performance in the Western literature include task performance, organizational citizenship behaviour (OCB), and counterproductive work behaviour (CWB). Limited research has investigated the cross-cultural generalizability of these categories or their content. Convergence and divergence theorists present competing perspectives on the cross-cultural applicability of Western management practices. The growing role of China in the world economy makes this culture an important one to consider. The present study contributes to job performance research in two important ways. First, Study 1 investigates whether CWB in China is described by similar or different behaviours as in the Western literature. Second, Study 2 examines the importance that Chinese managers place on task performance, OCB, and CWB. Findings indicate that Chinese managers are similar to North American managers in the content of CWB. Furthermore, Chinese managers value all three groups of behaviours when rating overall performance, placing greater emphasis on task performance and less emphasis on CWB than North American managers. The results suggest that cross-cultural research on job performance needs to take both convergence and divergence perspectives into account.
Recruiting leaders: an analysis of leadership advertisements

Recruiting the right leaders is an important challenge for organisations. How do organisations find these leaders? This article looks at the recruitment of leaders through advertisements. We address to what extent the 'vocabulary of leadership' originating in influential leadership theories is actively used in communication about leadership positions. All job advertisements (4,217) that appeared in a consistent source in the public domain in the UK (Times newspaper) were collected for a period of 15 months. Out of the total number of advertisements, 1,390 were advertisements for leadership positions (chairman, CEO or director). The information in these advertisements was recorded and content analysed. The analyses highlight what terminology organisations use in attracting the desired leaders. In general, 'people oriented' and 'transformational' terms are used far more than terms describing 'task oriented' or 'transactional' qualities. Differences were found between advertisements for CEO and lower level leader (director) positions that seem to reflect the difference in hierarchical level and magnitude of the leadership responsibility of these roles.
Consumer Sentiment and the Stock Market

This paper examines the relationship between movements in consumer sentiment and stock prices. At the aggregate level, the two share a strong contemporaneous relationship: an increase in equity values boosts sentiment. However, I examined the nature of the relationship between the two. Does an increase in stock prices raise aggregate sentiment because people are wealthier or because they use movements in stock prices as an indicator of future economic activity and potential labor income growth? Using individual observations from the Michigan survey I found results more consistent with the view that people use movements in equity prices as a leading indicator. Although the findings do not rule out a traditional wealth effect, they do raise some questions about the causal role of wealth in aggregate spending.
Process Preferences and American Politics: What the People Want Government to Be

We present evidence of the kind of governmental processes Americans would like to see in Washington. People believe they have been excluded from current processes, but they do not want direct democracy. The extent to which individuals believe actual processes are inconsistent with their own process preferences is an important variable in understanding the current public mood. Moreover, individual-level differences in level of dissatisfaction with democratic processes help explain variations in public approval of government and in willingness to comply with the outputs of government. Of course, many political attitudes and behaviors are influenced by fondness for the policies that government produces, but it is also the case that sentiments and actions are affected by the way government produces those policies. Far from being merely a means to a policy end, governmental process is important in its own right.