783 research outputs found

    ESSAYS ON CORPORATE INVESTMENT

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    This dissertation is comprised of three essays on corporate investment. The first essay, titled "What If the Firm Does Not Diversify? A Self-Selection Free Bayesian Approach", takes a comprehensive look at the diversification discount. By employing a switching regression model with the Bayesian data augmentation methodology, I compare the actual post-acquisition firm value of diversifying acquirers to the counter-factual alternative which is a non-diversifying acquisition. I find that there is a considerable amount of acquirers that could improve their value by diversifying acquisitions more than what they would improve by non-diversifying acquisitions. When there are negative shocks to the acquirers' primary industries, when these industries are concentrated and the firms are not dominant players in the industries, diversifying acquisitions add values to the firms. The firm-by-firm analysis shows that on average, no diversification discount exists. The next two essays study U.S. manufacturing firms' outsourcing activity, using a unique dataset of purchase obligations from firm 10-Ks. The second essay is titled "Outsourcing and Firm Financial Structure", and the third essay is titled "Firm Risk Taking versus CEO Diversification: Evidence from Outsourcing Firms". In the second essay, I explore the outsourcing decision and its implications on firm investment and capital structure. I first examine what kinds of firms use external contracts to provide a product or service as a major input to their production. I find that relatively young or large firms with a large number of patents are more likely to use external purchase contracts. Within high-technology industries, firms with purchase contracts tend to have higher R&D investment, while in low- technology industries, firms with purchase contracts are more likely to enter new markets. Outsourcing activity has important risk and capital structure implications, as firms that outsource have significantly less leverage. These results are consistent with outsourcing being used by firms to improve their flexibility. Faced with this increased firm flexibility and fewer fixed assets to pledge as collateral, outsourcing firms finance their operations proportionally more with equity. In the third essay, I examine CEO compensation in outsourcing firms. I find that the intensity of outsourcing can significantly explain the variations in CEO compensation; the more the firms do outsourcing, the more they pay to their CEOs. Outsourcing firms promote managerial risk-taking by using proportionally more equity-based compensation. However, they also need to compensate additionally their CEOs for the higher risk exposure to the firms' increased total risks. I show that outsourcing firms determine their compensation level and structure based on this optimal trade-off

    Acceptance and commitment therapy processes and their association with distress in cancer: a systematic review and meta-analysis

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    Around 42% of individuals with cancer experience distress. Acceptance and Commitment Therapy (ACT) can reduce distress, but effects are small, and mechanisms unclear. This review aimed to identify associations between ACT processes and distress in cancer. Search terms included cancer, ACT processes, self-compassion, and distress. Six online databases and grey literature were searched to March 2022. Of 6555 papers screened, 108 studies were included with a total of 17195 participants. Five meta-analyses of seventy-seven studies were conducted. Random effects meta-analyses of correlations revealed higher scores on flexible processes (acceptance, present moment awareness, self-compassion) were associated with lower distress (rpooled = -0.24, -0.39, -0.48, respectively); whilst higher scores on inflexible processes (experiential avoidance, cognitive fusion) were associated with higher distress (rpooled = 0.58, 0.57, respectively). Meta-analyses displayed moderate-to-high heterogeneity with most studies assessed as low risk of bias. Meta-regressions revealed no significant moderators (stage, time since diagnosis, gender and age). This review provides a theoretically aligned evidence base for associations between ACT processes and distress in cancer, supporting elements of ACT theory and providing targeted directions for intervention development. Due to limited evidence, future research should focus on the under-investigated processes (self-as-context, values, committed action) and conducting mediation analysis of ACT processes on distress in cancer in controlled trials

    Predicting Responses of Geo-ecological Carbonate Reef Systems to Climate Change: A Conceptual Model and Review

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    Coral reefs provide critical ecological and geomorphic (e.g. sediment production for reef-fronted shoreline maintenance) services, which interact in complex and dynamic ways. These services are under threat from climate change, requiring dynamic modelling approaches that predict how reef systems will respond to different future climate scenarios. Carbonate budgets, which estimate net reef calcium carbonate production, provide a comprehensive ‘snap-shot’ assessment of reef accretionary potential and reef stability. These budgets, however, were not intended to account for the full suite of processes that maintain coral reef services or to provide predictive capacity on longer timescales (decadal to centennial). To respond to the dual challenges of enhancing carbonate budget assessments and advancing their predictive capacity, we applied a novel model elicitation and review method to create a qualitative geo-ecological carbonate reef system model that links geomorphic, ecological and physical processes. Our approach conceptualizes relationships between net carbonate production, sediment transport and landform stability, and rates knowledge confidence to reveal major knowledge gaps and critical future research pathways. The model provides a blueprint for future coral reef research that aims to quantify net carbonate production and sediment dynamics, improving our capacity to predict responses of reefs and reef-fronted shorelines to future climate change

    Spinolaminar line test as a screening tool for C1 stenosis.

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    Study Design Retrospective cohort. Objective To clarify the sensitivity of C3–C2 spinolaminar line test as a screening tool for the stenosis of C1 space available for the cord (SAC). Methods Spine clinic records from April 2005 to August 2011 were reviewed. The C1 SAC was measured on lateral radiographs, and the relative positions between a C1 posterior arch and the C3–C2 spinolaminar line were examined and considered positive when the C1 ring lay ventral to the line. Computed tomography (CT) scans and magnetic resonance imaging (MRI) were utilized to measure precise diameters of C1 and C2 SAC and to check the existence of spinal cord compression. Results Four hundred eighty-seven patients were included in this study. There were 246 men and 241 women, with an average age of 53 years (range: 18 to 86). The mean SAC at C1 on radiographs was 21.2 mm (range: 13.5 to 28.2). Twenty-one patients (4.3%) were positive for the spinolaminar line test; all of these patients had C1 SAC of 19.4 mm or less. Eight patients (1.6%) had C1 SAC smaller than C2 on CT examination; all of these patients had a positive spinolaminar test, with high sensitivity (100%) and specificity (97%). MRI analysis revealed that two of the eight patients with a smaller C1 SAC had spinal cord compression at the C1 level. Conclusion Although spinal cord compression at the level of atlas without instability is a rare condition, the spinolaminar line can be used as a screening of C1 stenosis.OAIID:oai:osos.snu.ac.kr:snu2016-01/102/0000004226/3ADJUST_YN:NEMP_ID:A079510DEPT_CD:801FILENAME:2016_spinolaminar line test as a screening tool for c1 stenosis.pdfDEPT_NM:ì˜í•™êłŒCONFIRM:

    Predicting Responses of Geo-ecological Carbonate Reef Systems to Climate Change: A Conceptual Model and Review

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    [Chapter Abstract] 230Coral reefs provide critical ecological and geomorphic (e.g. sediment production for reef-fronted shoreline maintenance) services, which interact in complex and dynamic ways. These services are under threat from climate change, requiring dynamic modelling approaches that predict how reef systems will respond to different future climate scenarios. Carbonate budgets, which estimate net reef calcium carbonate production, provide a comprehensive ‘snap-shot’ assessment of reef accretionary potential and reef stability. These budgets, however, were not intended to account for the full suite of processes that maintain coral reef services or to provide predictive capacity on longer timescales (decadal to centennial). To respond to the dual challenges of enhancing carbonate budget assessments and advancing their predictive capacity, we applied a novel model elicitation and review method to create a qualitative geo-ecological carbonate reef system model that links geomorphic, ecological and physical processes. Our approach conceptualizes relationships between net carbonate production, sediment transport and landform stability, and rates knowledge confidence to reveal major knowledge gaps and critical future research pathways. The model provides a blueprint for future coral reef research that aims to quantify net carbonate production and sediment dynamics, improving our capacity to predict responses of reefs and reef-fronted shorelines to future climate change.https://nsuworks.nova.edu/occ_facbooks/1116/thumbnail.jp

    How Well Does Societal Mobility Restriction Help Control the COVID-19 Pandemic? Evidence from Real-Time Evaluation

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    One of the most widely implemented policy response to the novel coronavirus (SARS-CoV-2) pandemic has been the imposition of restrictions on mobility (1). These restrictions have included both incentives, encouraging working from home, supported by a wide range of online activities such as meetings, lessons, and shopping, and sanctions, such as stay at home orders, restrictions on travel, and closure of shops, offices, and public transport (2-5). The measures constitute a major component of efforts to control the COVID-19 pandemic. Compared to previous epidemic responses, they are unprecedented in both scale and scope (6). The rationale underpinning these public health measures is that restricting normal activities decreases the number, duration, and proximity of interpersonal contacts and thus the potential for viral transmission. Transmission simulations using complex mathematical modelling have built on past experience such as the 1918 influenza epidemic (7), as well as assumptions about the contemporary scale and nature of contact in populations (8). However, the initial models were not always founded on empirical evidence from behavioral scientists on the feasibility or sustainability of mass social and behavior change in contemporary society. While reductions in interpersonal contact and increases in physical distancing are known to decrease respiratory infection spread (9), the paucity of recent examples of large-scale restrictions on mobility has limited the scope for research on their impact on transmission. Where restrictions have been imposed, as with Ebola, they have involved diseases with a different mode of transmission. Nonetheless, the rapidity of progression of this pandemic has forced many governments into trialing various approaches to containment with limited evidence of effectiveness (10). More conventional public health prevention measures (such as quarantine of contacts, isolation of infected individuals and contact tracing) and control measures in health systems (such as patient flow segregation, negative pressure ventilation, and use of personal protective equipment) (11-14), have been applied widely to control the epidemic in many countries as part of a portfolio of policy responses. However, mobility restriction as a new large-scale mass behavioral and social prescription has incurred considerable costs (15, 16). Estimates suggest global GDP growth has fallen by as much as 10% (17), at least in part due to mobility restriction policies. Although views differ, not least because of the lack of information of what would happen if the disease was unchecked and the emerging evidence of persisting disability in survivors, some have argued that this is greater than would be accounted for by the economic impact of direct illness and deaths from COVID-19 (18, 19). To inform decisions on large scale restrictions of mobility, there is an urgent need to assess their effectiveness in limiting pandemic spread. To this end, we examined the association of mobility with COVID-19 incidence in Organization of Economic Cooperation and Development (OECD) countries and equivalent economies such as Singapore and Taiwan

    Azetidines Kill Multidrug-Resistant <i>Mycobacterium tuberculosis</i> without Detectable Resistance by Blocking Mycolate Assembly

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    Tuberculosis (TB) is the leading cause of global morbidity and mortality resulting from infectious disease, with over 10.6 million new cases and 1.4 million deaths in 2021. This global emergency is exacerbated by the emergence of multidrug-resistant MDR-TB and extensively drug-resistant XDR-TB; therefore, new drugs and new drug targets are urgently required. From a whole cell phenotypic screen, a series of azetidines derivatives termed BGAz, which elicit potent bactericidal activity with MIC99 values &lt;10 ÎŒM against drug-sensitive Mycobacterium tuberculosis and MDR-TB, were identified. These compounds demonstrate no detectable drug resistance. The mode of action and target deconvolution studies suggest that these compounds inhibit mycobacterial growth by interfering with cell envelope biogenesis, specifically late-stage mycolic acid biosynthesis. Transcriptomic analysis demonstrates that the BGAz compounds tested display a mode of action distinct from the existing mycobacterial cell wall inhibitors. In addition, the compounds tested exhibit toxicological and PK/PD profiles that pave the way for their development as antitubercular chemotherapies. </p
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