Innovation and trade policy in a globalized world

How do import tariffs and R&D subsidies help domestic firms compete globally? How do these policies affect aggregate growth and economic welfare? To answer these questions, we build a dynamic general equilibrium growth model where firm innovation endogenously determines the dynamics of technology, market leadership, and trade flows, in a world with two large open economies at different stages of development. Firms’ R&D decisions are driven by (i) the defensive innovation motive, (ii) the expansionary innovation motive, and (iii) technology spillovers. The theoretical investigation illustrates that, statically, globalization (defined as reduced trade barriers) has ambiguous effects on welfare, while, dynamically, intensified globalization boosts domestic innovation through induced international competition. Accounting for transitional dynamics, we use our model for policy evaluation and compute optimal policies over different time horizons. The model suggests that the introduction of the Research and Experimentation Tax Credit in 1981 proves to be an effective policy response to foreign competition, generating substantial welfare gains in the long run. A counterfactual exercise shows that increasing tariffs as an alternative policy response improves domestic welfare only when the policymaker cares about the very short run, and only when introduced unilaterally. Tariffs generate large welfare losses in the medium and long run, or when there is retaliation by the foreign economy. Protectionist measures generate large dynamic losses by distorting the impact of openness on innovation incentives and productivity growth. Finally, our model predicts that a more globalized world entails less government intervention, thanks to innovation-stimulating effects of intensified international competition

Economic Policy in a More Uncertain World

The Aspen Economic Strategy Group's Annual Policy Volume Economic Policy in a More Uncertain World marks the group's 5th anniversary and is released against a backdrop historic economic and strategic uncertainty. The book's seven chapters, each written by leading experts and edited by AESG Director Melissa S. Kearney and Deputy Director Amy Ganz, provide a deep-dive on long-term economic headwinds confronting the country, including demographic changes—declining fertility and population aging—and what a smaller worker to population ratio means in terms of slower economic growth, reduced revenue, and lower productivity growth. Additional chapters on the US immigration system and US innovation policy highlight potential solutions for countering these trends.  Another chapter explores potential adverse impacts on local labor markets from the green energy transition and highlights policies to avoid repeating painful mistakes of the past, including the response to the decline of the coal industry and rise of globalization and automation. A final chapter highlights lessons learned from the unprecedented federal aid to state and local governments during the COVID-19 pandemic

Effect of pozzolanic material on the restrained shrinkage behavior of self-consolidating concrete

Self-consolidating concrete (SCC) has been the subject of various research projects, and its use has been a source of increasing interest in industry. The very early phase of SCC research mainly focused on mechanical and fresh concrete properties. The area of SCC research was then enlarged with the inclusion of shrinkage behavior. This was necessary because SCC as a concrete type was always presumed to exhibit higher levels of free and restrained shrinkage due to its higher cementitious material content. Given that concrete in general has very low tensile strength capacity, especially the deformations caused by restrained shrinkage behavior are among the primary concerns related to SCC. Restrained shrinkage behavior of SCC is investigated in this study, with the emphasis on cracking ages and patterns. The AASHTO-T334 test setup is used to evaluate the cracking potential of the SCC mixes. In addition to the steel ring data collection method of AASHTO-T334, Vibrating Wire Sensor Gages (VWSG) were also implemented to collect concrete strain measurements. Many other laboratory tests such as the compressive strength, splitting tensile strength, modulus of elasticity, and free shrinkage were performed in companion with the restrained shrinkage test. The resistance to restrained shrinkage cracking of the SCC was found to be weak since all the SCC mixes cracked under restrained shrinkage before day 56 after casting. Moreover, except for one SCC mix, the cracking was observed only between day 19 and 31 after casting. Amount of total cementitious material was found to have the greatest effect on the restrained and free shrinkage performance of the SCC mixes. Partial replacement of Portland cement with high percentages of fly ash was found to have the potential to increase the elapsed time until cracking. If silica fume was used as a replacement, the cracking performance was slightly worse whereas the free shrinkage strain increased 10 % at day 56 after casting.M.S.Includes abstractIncludes bibliographical referencesby Ufuk Ate

Pericoronal radiolucency associated with an impacted premolar tooth

The mandibular second premolar is highly variable developmentally. Agenesis, abnormal tooth germ position, distal inclination of the developing tooth, and impaction are among the reported developmental anomalies. Detection of pathologic lesions associated with an impacted tooth usually requires removal of the tooth and the lesion. The purpose of the present report was to describe the radiographic and histopathologic features of a case of pericoronal radiolucency associated with an impacted mandibular premolar tooth

Beating heart versus conventional mitral valve surgery

Objectives: The present study aimed to compare the results of beating heart technique and conventional mitral valve surgery (MVS). Methods: Three hundred and nineteen patients who underwent MVS between April 2005 and December 2006 were enrolled in the study. While 125 patients underwent beating heart MVS (group 1), the conventional approach was used for 194 patients (group 2). Of those patients who underwent beating heart MVS, 75 underwent MVS without cross-clamping the aorta. Coronary sinus retroperfusion was used during surgery in the remaining 50 patients. The right anterolateral thoracotomy was performed in nine out of the 29 patients requiring re-operation, while resternotomy was performed in 20. Results: No significant differences were shown between the groups in the preoperative period in terms of the Parsonnet mortality score, Ontario mortality score, and length of intensive care stay. However, there were significant differences with respect to EuroSCORE risk score, EuroSCORE mortality, and Parsonnet risk score, and length of hospital stay according to Ontario risk scoring. It was established that the patients in group 1 had a shorter length of hospital stay [group 1: six days (range, 4-37 days); group 2: 10 days (range, 4-62 days)]. Group 1 was observed to have shorter time periods when the groups were compared regarding operative time [group 1: 130 min (range, 100-270 min); group 2: 240 min (range, 100-360 min)], cross-clamping (XCL) time [group 1: 27.5 min (range, 3-99 min); group 2: 60.5 min (range, 30-163 min)], and cardiopulmonary bypass time [group 1: 57 min (range, 22-150 min); group 2: 90 min (range, 39-388 min)]. There were also significant differences in favor of group 1 in terms of postoperative need for inotropic support wgroup 1: 26 patients (16%); group 2: 68 patients (35%) x. Although there were no statistically significant differences in the groups in terms of mortality rates according to the Parsonnet scoring system, with the exception of the moderate risk group, it was noted that the mortality rates in the beating heart group were lower. Conclusions: This study concluded that beating heart MVS can be performed successfully, particularly for patients at higher risk which will lead to increased morbidity and mortality in postoperative period. (C) 2011 Published by European Association for Cardio-Thoracic Surgery. All rights reserved

Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly

Evaluation of PCA3 and multiparametric MRI’s: collective benefits before deciding initial prostate biopsy for patients with PSA level between 3-10ng/mL

ABSTRACT Objective To analyze the contribution of multiparametric MRI and PCA3 assay, pre- decision of initial biopsy in PSA level between 3-10 ng/mL patients with normal digital rectal examination(DRE). Materials and Methods PSA level 3-10 ng/mL ,patients, with normal DRE results and no previous prostate biopsy history, were included in this study. Each patient underwent multiparametric MRI one week before biopsy. Urine sample taking for PCA3 examination preceded the biopsy. Systematic and targeted biopsies were conducted. Patients with high PSA levels were seperated into two groups as: high PCA3 scored and low PCA3 scored. Then each group was divided into two sub-groups as: MRI lesion positive and negative. Tumor incidence, positive predictive values(PPV) and negative predictive values(NPV) were calculated. Results 53 patients were included between February 2013 and March 2014.Mean age 61.22 ± 1.06. Mean PSA value 5.13 ± 0.19 ng / mL. Mean PCA3 score 98.01 ± 23.13 and mean prostate size was 48.96 ± 2.67 grams. Fourty nine patients had both PCA3 score and multiparametric MRI. The PCA3’s PPV value was 58.33%. If multiparametric MRI lesions are added to high PCA3 scores , the PPV appears to elevate to 91.66%. NPV of PCA3 was 96%. NPV was 95% when there was no lesion in the multiparametric MRI with low PCA3 scores. Sensitivity was 91.66% , specificity was 95% respectively. Conclusion Adding multimetric MRI can also support biopsy decision for patients with high PCA3 value. When PCA3 value is low, patients can be survailled without any need to take a MRI