Technology adoption and innovation: The establishment of airmail and aviation innovation in the United States, 1918–1935

RESEARCH SUMMARY: This article explores how technology adoption can shape innovative activity. We study this issue within the historical context of the introduction and expansion of airmail across the United States between 1918 and 1935 using archival material and a novel dataset of early 20th century patents. A joint qualitative and quantitative investigation indicates that local individual and corporate actors applied diverse pools of knowledge and intensified their work with aviation innovations following airmail entry into their county. Moreover, we find evidence that the co‐location of aircraft manufacturing and airmail operations was associated with more corporate innovations that facilitated economies of scale and corresponded to increased technological diversification of firms' aviation patent portfolios. Ultimately, this paper deepens our understanding of the antecedents, consequences, and organizational processes that underpin innovation. MANAGERIAL SUMMARY: This research investigates how aviation innovation in the United States was influenced by the postal service's early 20th century introduction and expansion of airmail routes. Our results indicate that counties with an airmail route experienced increased aviation‐related patenting by individual and corporate inventors relative to similar counties that did not receive an airmail route. Moreover, we find that corporate inventors working in airmail counties that also contained aircraft manufacturers were particularly active in technological areas that enhanced aircraft economies of scale and patented in a wider range of aviation‐related domains. An implication of this work for managers and policymakers is that early access to nascent technology can be a driver of local innovation and that spillovers can benefit diverse economic actors working in close proximity

Relationship of university research to industry and innovation

Thesis: Ph. D., Massachusetts Institute of Technology, Sloan School of Management, 2015.Cataloged from PDF version of thesis.Includes bibliographical references.This dissertation examines how the rate and direction of scientific science is endogenous to the institutional, technological and economic environment. The first essay investigates how local industrial R&D impacts the rate and direction of academic research by measuring the geographically localized spillover effect from industry R&D headquarters to nearby universities, which I call "reverse knowledge spillovers". To address the endogeneity concerns due to selection of industry location, this study exploits the exogenous entry into plant biotechnology R&D by pre-existing agribusiness incumbents in non-biotechnology clusters. I find that after the industry incumbents' entry into plant biotechnology R&D, collocated universities with the institutional capacity for industry boundary-spanning experienced a significant productivity increase in industry-relevant fields of science. As a further investigation into the phenomenon of "reverse knowledge spillovers", the second essay examines the individual antecedents that incentivize university scientists to engage in industry-relevant research. I argue that young and less prominent scientists have a stronger incentive to exploit new opportunities provided by the local industry due to the lack of alternatives and less opportunity cost. Finally, the third essay provides a theoretical overview of the endogeneity of science. The purpose of this essay is to deepen our understanding of Science as an economic institution, and to draw out some of the crucial pathways by which the structure, conduct and performance of the scientific research enterprise is endogenous to the institutional environment, technology and economic objectives.by Eunhee Sohn.Ph. D

Does the pressure to fill journal quotas bias evaluation?: Evidence from publication delays and rejection rates.

Although the peer review system of academic journals is seen as fundamental to scientific achievement, a major threat to the validity of the system is a potential evaluation bias resulting from constraints at the journal level. In this study, we examine how the time pressure to maintain a fixed periodical quota for journal publication can influence a journal editor's decision to accept or reject a paper at any given point in time. We find that an increase in publication backlog, proxied as the average delay between paper acceptance and print publication, is correlated with an increase in the subsequent rejection rates of new submissions. Our findings suggest that time pressures inherent in the peer review system may be a source of potential evaluator bias, calling for a need to reconsider the current quota system

Technological Catching-up and Latecomer Strategy: A Case Study of the Asian Shipbuilding Industry

This paper investigates the role of imitation and innovation in technological catching-up. On the one hand, excessive innovation and no imitation can never provide latecomers with absorptive capacity to embark on catching-up along the existing technological trajectory. On the other hand, excessive imitation and no innovation can debilitate the ability of latecomer firms to leapfrog incumbents by creating a new trajectory and further reducing the technological gap. Thus, we argue that successful technological catching-up in the long term can hardly be achieved without a fine balance between imitation and innovation at the early stage of catching-up. We also propose that occurrence of technological uncertainty at the later stage of catching-up allows latecomers with such balance to realize radical technological leapfrogging. By conducting a case study on the shipbuilding industry in the 20th century, we find supporting evidence that validates our argument

Perfusion Computed Tomography Evaluation of Cerebral Hemodynamic Impairment in Patients With Unilateral Chronic Steno-Occlusive Disease: A Comparison With the Acetazolamide Challenge (99m)Tc-Hexamethylpropyleneamine Oxime Single-Photon Emission Computed Tomography

Purpose: The purpose of this study was to determine which pefusion computed tomography (PCT) parameter is the most valid predictor of cerebral vascular reserve (CVR) as determined by (99m)Tc-hexamethylpropylencamine oxime single-photon emission computed tomography (SPECT). Methods: Single-photon emission computed tomography with acetazolamide challenge and PCT were used in 23 patients with unilateral steno-occlusive vascular disease. After coregistration of the PCT and SPECT images, we assessed the relationship between the PCT parameters and SPECT findings and the predictive values of the PCT parameters for decreased CVR. Results: All PCT parameters of cerebral blood flow, cerebral blood volume, and mean transit time (MTT) were significantly correlated with SPECT regional cerebral blood flow ratios (P < 0.01). The MTT values more strongly correlated with acetazolamide effect than with cerebral blood volume or cerebral blood flow (P < 0.001). The MTT difference (values in the pathological hemisphere minus the values in the contralateral hemisphere) was a threshold of 1.5 seconds, with a sensitivity of 88% and a specificity of 70% for predicting decreased CVR. Conclusion: Mean transit time is the most predictive parameter for assessing decreased CVR in patients with unilateral steno-occlusive vascular disease.Chen A, 2006, AM J NEURORADIOL, V27, P1876Wintermark M, 2006, STROKE, V37, P979, DOI 10.1161/01.STR.0000209238.61459.39Yata K, 2006, STROKE, V37, P534, DOI 10.1161/01.STR.0000199085.40000.cfWintermark M, 2006, AM J NEURORADIOL, V27, P26Miyazawa N, 2005, CLIN NEUROL NEUROSUR, V108, P11, DOI 10.1016/j.clineuro.2004.12.024Eskey CJ, 2005, NEUROIMAG CLIN N AM, V15, P367, DOI 10.1016/j.nic.2005.05.002Ito H, 2005, ANN NUCL MED, V19, P65ESKEY CJ, 2005, NEUROIMAG CLIN N AM, V15, pR11Kealey SM, 2004, RADIOLOGY, V231, P587, DOI 10.1148/radiol.2312030489Lee HY, 2004, J NUCL MED, V45, P202Kudo K, 2003, AM J NEURORADIOL, V24, P419Wintermark M, 2002, STROKE, V33, P2025Derdeyn CP, 2002, BRAIN, V125, P595Eastwood JD, 2002, AM J NEURORADIOL, V23, P285Eastwood JD, 2002, RADIOLOGY, V222, P227Kuroda S, 2001, STROKE, V32, P2110Roberts HC, 2001, AM J NEURORADIOL, V22, P1077Wintermark M, 2001, EUR RADIOL, V11, P1220Schumann P, 1998, BRAIN, V121, P1369ASENBAUM S, 1995, NEURORADIOLOGY, V37, P13KNOP J, 1992, STROKE, V23, P1733YAMASHITA T, 1991, NEURORADIOLOGY, V33, P217GEMMELL HG, 1990, J NUCL MED, V31, P1595HEISS WD, 1990, J CEREBR BLOOD F MET, V10, P687SETTE G, 1989, BRAIN, V112, P931POWERS WJ, 1987, ANN INTERN MED, V106, P27GIBBS JM, 1984, LANCET, V1, P182AXEL L, 1983, INVEST RADIOL, V18, P94

Muslinoma and muslin-induced foreign body inflammatory reactions after surgical clipping and wrapping for intracranial aneurysms: imaging findings and clinical features Clinical article

Object. Reinforcement of aneurysms with additional wrapping is an alternative procedure if the aneurysm cannot be completely clipped. Wrapping with muslin (cotton gauze) rarely incites foreign body inflammatory reactions. In this study, the authors describe the clinical and radiological features of muslinomas or muslin-induced foreign body reactions that can develop after treatment of intracranial aneurysms. Methods. Over a 3-year period, 5 patients with muslinomas underwent treatment at the authors` institution. All patients underwent aneursym clipping and wrapping, and were subsequently readmitted with acute or subacute neurological symptoms. Clinical and imaging features on diffusion weighted MR images and cerebral angiography images were retrospectively reviewed. The patients` clinical course and follow-up imaging studies were also evaluated. Results. In all 5 cases, muslinomas were seen as rim-enhancing inflammatory masses around the clipped aneurysms with perilesional edema visible on MR images at the time of clinical deterioration. The MR images also demonstrated adhesive arachnoiditis with a sterile intracranial abscess in 3 patients, optic neuropathy in 2, parent artery narrowing in 2, and a resultant acute ischemic infarction in 1 patient. Follow-up imaging revealed resolution of both the perilesional edema and adhesive arachnoiditis but no significant changes in the muslinomas. All patients underwent conservative management and fully recovered, but during the follow-up period, 2 patients experienced clinical and radiological relapses. Conclusions. When a patient with a history of wrapping of an aneurysm presents with acute neurological symptoms and an enhancing intracranial mass in the region of the surgical site on MR imaging, a muslin-induced foreign body inflammatory reaction should be considered in the differential diagnosis, and careful clinical and radiological follow-up is advised.Yasuda H, 2005, NEUROPATHOLOGY, V25, P66Goldsberry DH, 2004, J NEURO-OPHTHALMOL, V24, P42Berger C, 2003, EUR J NEUROL, V10, P153Brochert A, 2003, NEURORADIOLOGY, V45, P82, DOI 10.1007/s00234-002-0896-6Bhatti MT, 2000, AM J NEURORADIOL, V21, P346Brady KM, 1999, SURG NEUROL, V51, P566Kirollos RW, 1997, ACTA NEUROCHIR, V139, P411KURITA H, 1995, NEUROSURGERY, V36, P1225PRABHU SS, 1994, BRIT J NEUROSURG, V8, P471FELSBERG GJ, 1993, J COMPUT ASSIST TOMO, V17, P485BEDERSON JB, 1992, J NEUROSURG, V77, P478ONOUE H, 1992, NEUROSURG REV, V15, P307MCFADZEAN RM, 1991, J NEUROSURG, V75, P393MORIOKA M, 1991, NEUROL MED CHIR TOKY, V31, P135SADASIVAN B, 1990, SURG NEUROL, V34, P3HAISA T, 1990, J NEUROSURG, V72, P292CHAMBI I, 1990, J NEUROSURG, V72, P163REPKA MX, 1984, J CLIN NEURO-OPHTHAL, V4, P147CARNEY PG, 1983, J CLIN NEURO-OPHTHAL, V3, P91HORI S, 1979, J NEUROSURG, V50, P433TAYLOR JC, 1977, J NEUROSURG, V47, P828SACHS E, 1972, ACTA NEUROCHIR, V26, P121