146 research outputs found
A Cheap Ticket to the Dance: Systematic Bias in College Basketball's Ratings Percentage Index
A contest model is constructed to examine the existence of conference bias in college basketball's Ratings Percentage Index (RPI). Though a general RPI bias has been identified in previous literature, this is the first study to address whether the bias is random or systematic in nature. Within the theoretical model, the RPI is shown to be systematically biased against teams in high ability conferences, even when all teams play to expectation and can be transitively compared. Further, the bias can prevent the RPI from producing an ordinal mapping from revealed team ability level to the real number line. Given the longevity of the controversial RPI as the NCAA''s primary measure of team ability, these results may indicate that the NCAA is serving a demand for team heterogeneity in selecting for the NCAA Men''s Basketball Tournament.bias
The dynamics of divorce, income, and female labor force participation in Singapore.
Singapore has experienced rising income and female labor force participation over the years. This growth, however, is also accompanied by increasing divorce rate. This paper utilizes Granger causality tests within a multivariate error correction framework to examine the short-run and long-run causal interactions among divorce, income and female labor force participation in Singapore. The long–run results suggest the presence of tradeoffs between income, female labor participation and the family unit, with the twin objectives of economic expansion and the move to draw more women into the labor market having a negative impact on the institution of marriage.causality, divorce, female labor force participation, income, Singapore
Are we explaining the movement of hotel room rates correctly?
Demand function, inverse demand function or market equilibrium condition has been used to estimate the empirical models that explain the movement of hotel room rates. However, hotels generally face excess supply of rooms. This research paper develops a simple theoretical model to link hotel room rates to excess supply of hotel rooms. The annual data of Singapore from 1991 to 2017 is used to test this framework. Due to small sample size, with only 27 observations, the bounds testing approach to cointegration is applied on the annual data of hotel industry in Singapore because the obtained estimators are super-consistent. It is found that average hotel room rate and average hotel occupancy rate are cointegrated to confirm hotel room rates and excess supply of hotel rooms are inversely correlated. In order to avoid model mis-specification, major crises are captured by dummy variables which are treated as fixed regressors in the bounds testing approach to cointegration. The empirical and theoretical frameworks used in this study suggest that when hotel occupancy rate is used as an independent variable in modelling the determination of hotel room rates, a researcher is adopting excess supply framework developed in this paper. Furthermore, this framework teaches students in tourism a simplified way to explain the movement of hotel room rates, while still reminding students about the complexity of hotel industry
Modified TAROT for cross-selling personal financial products
The Top Application characteristics Remainder Offer characteristics Tree (TAROT) was first introduced in 2007. This is a modified Classification and Regression Trees (CART) used to help decide which question(s) to ask potential applicants to customise an offer of a personal financial product so that it would have a high probability of take up. In this piece of work the authors are presenting, they have further modified the TAROT to cross TAROT, using its properties and modeling steps to deal with the issue of cross-selling. Since the bank already has ready customers, it would be ideal to cross-sell the financial products seeing that one can ask one (or more) further question(s) based on the initial offer to identify and customise another financial product to offer
Business incubators as an economic development strategy : a case study of Oakland's communications technology cluster
Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2000.Includes bibliographical references (leaves 73-77).Business incubators are a rapidly growing trend in economic development. The National Business Incubator Association estimates there are nearly 600 incubators in North America today which each help create over 500 jobs. Through the provision of real estate, physical amenities, and business services, incubators can improve the success rates of small businesses, which in turn translates into jobs, diversification of the local economy, and tax base expansion. The growth of the high technology sector promises to generate quality, well-paying jobs. Therefore, communities are pumping large sums of public dollars to support and sustain high tech business incubators. However, without a full understanding of how incubators impact local communities, it is difficult to justify these public investments. Moreover, without evaluating its strengths and weaknesses, and how the incubator fits within the communities' larger business development strategy, opportunities to further improve this economic development tool in practice may be overlooked. This thesis assesses the impact of the Communications Technology Cluster (CTC) located in Oakland, California. Using business attraction, job creation, business retention, and effects on city image as evaluation measurements, this research shows that CTC has produced mixed results. In the process of evaluating CTC, several larger issues emerge, of which workforce development, business services, and the city's hard and "soft" infrastructure are identified as key impediments to the realization of the city's economic development goals. In light of these findings, this thesis proposes an action strategy for improving the incubator's operations and for considering new ways of thinking about the incubator's role in the overall economic development strategy. The thesis concludes with the argument that the publicly affiliated incubator should be integrated into the community's overall strategy in order to achieve its full impact. This has implications for economic development practitioners. By extracting lessons from the case study of CTC in Oakland, economic development practitioners can begin to consider the existing assets and liabilities of the city, and design an incubator strategy tailored to best meet the needs and objectives of the local community.by Carolyn Ging Lee.M.C.P
Comparison of Magnetic Resonance Imaging and Serum Biomarkers for Detection of Human Pluripotent Stem Cell-Derived Teratomas.
The use of cells derived from pluripotent stem cells (PSCs) for regenerative therapies confers a considerable risk for neoplastic growth and teratoma formation. Preclinical and clinical assessment of such therapies will require suitable monitoring strategies to understand and mitigate these risks. Here we generated human-induced pluripotent stem cells (iPSCs), selected clones that continued to express reprogramming factors after differentiation into cardiomyocytes, and transplanted these cardiomyocytes into immunocompromised rat hearts post-myocardial infarction. We compared magnetic resonance imaging (MRI), cardiac ultrasound, and serum biomarkers for their ability to delineate teratoma formation and growth. MRI enabled the detection of teratomas with a volume >8 mm(3). A combination of three plasma biomarkers (CEA, AFP, and HCG) was able to detect teratomas with a volume >17 mm(3) and with a sensitivity of more than 87%. Based on our findings, a combination of serum biomarkers with MRI screening may offer the highest sensitivity for teratoma detection and tracking
The efficiency of the hotel industry in Singapore
Existing literature related to evaluating the efficiency of the hotel industry, generally, uses different types of radial Data Envelopment Analysis (DEA) to compare the relative efficiency of different hotels in a location. This research note has adopted a different approach by treating years as decision making units (DMUs). This will allow policymakers to evaluate the relative efficiency of a hotel industry as a whole over a specified time period so that the effects of the occurrence of events on the efficiency of hotel industry can be evaluated. This study focuses on the efficiency of hotel industry in Singapore from 1995 to 2010. The analysis is carried out using the non-radial DEA called the Slacks-Based Measure (SBM) to identify the efficient years. Then the efficient DMUs are ranked with the SBM model of super-efficiency
Allogeneic mesenchymal stromal cells overexpressing mutant human Hypoxia-inducible factor 1-α (HIF1-α) in an ovine model of acute myocardial infarction
Background-Bone marrow mesenchymal stromal cells (BMMSCs) are cardioprotective in acute myocardial infarction (AMI) because of release of paracrine angiogenic and prosurvival factors. Hypoxia-inducible factor 1-α (HIF1-α), rapidly degraded during normoxia, is stabilized during ischemia and upregulates various cardioprotective genes. We hypothesized that BMMSCs engineered to overexpress mutant, oxygen-resistant HIF1-α would confer greater cardioprotection than nontransfected BMMSCs in sheep with AMI. Methods and Results-Allogeneic BMMSCs transfected with a minicircle vector encoding mutant HIF1-α (BMMSC-HIF) were injected in the peri-infarct of sheep (n=6) undergoing coronary occlusion. Over 2 months, infarct volume measured by cardiac magnetic resonance (CMR) imaging decreased by 71.7±1.3% (P < 0.001), and left ventricular (LV) percent ejection fraction (%EF) increased near 2-fold (P < 0.001) in the presence of markedly decreased end-systolic volume. Sheep receiving nontransfected BMMSCs (BMMSC; n=6) displayed less infarct size limitation and percent LVEF improvement, whereas in placebo-treated animals (n=6), neither parameters changed over time. HIF1-α-transfected BMMSCs (BMMSC-HIF) induced angio-/arteriogenesis and decreased apoptosis by HIF1-mediated overexpression of erythropoietin, inducible nitrous oxide synthase, vascular endothelial growth factor, and angiopoietin-1. Cell tracking using paramagnetic iron nanoparticles in 12 additional sheep revealed enhanced long-term retention of BMMSC-HIF. Conclusions-Intramyocardial delivery of BMMSC-HIF reduced infarct size and improved LV systolic performance compared to BMMSC, attributed to increased neovascularization and cardioprotective effects induced by HIF1-mediated overexpression of paracrine factors and enhanced retention of injected cells. Given the safety of the minicircle vector and the feasibility of BMMSCs for allogeneic application, this treatment may be potentially useful in the clinic.Fil: Hnatiuk, Anna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Ong, Sang-Ging. Stanford University School of Medicine; Estados UnidosFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Riegler, Johannes. Stanford University School of Medicine; Estados UnidosFil: Lee, Won Hee. Stanford University School of Medicine; Estados UnidosFil: Jen, Cheng Hao. University of London; Reino UnidoFil: De Lorenzi, Andrea. Fundación Favaloro; ArgentinaFil: Giménez, Carlos Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Laguens, Rubén. Universidad Favaloro; ArgentinaFil: Wu, Joseph C.. Stanford University School of Medicine; Estados UnidosFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentin
Experimental demonstration of the relationship between the second- and third-order polarizabilities of conjugated donor-acceptor molecules
The dependence of the second- and third-order polarizabilities ((beta) and (gamma) ) on ground-state polarization was measured for a series of donor-acceptor polyenes using electric field induced second harmonic generation and third harmonic generation, respectively. The changes in ground-state polarization, associated with the donor/acceptor strength or solvent polarity, were probed by x-ray crystallography, 1H-NMR, electronic absorption, and Raman spectroscopies. The observed behavior of (beta) and (gamma) as a function of ground- state polarization agrees well with theoretical predictions. In particular, positive and negative peaks, as well as sign changes, were observed for both (beta) and (gamma) . The dependences for (beta) and (gamma) are consistent with a derivative relationship between them. In addition, the third-order polarizability of a series of molecules possessing zero bond length alternation was found to be negative, in agreement with predictions based on the relationship between the polarizabilities and ground-state geometry
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