France and Japan in space : niche market players, with evolving assets and roles

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1991.Includes bibliographical references (leaves 131-137).by Damon R. Wells.M.S

Understanding the Role of Theory on Instrument Development: An Examination of Strengths and Weaknesses of Discriminant Validity Analysis Techniques

Numerous researchers have called attention to many important issues in instrument development throughout the relatively short history of the information systems (IS) academic research discipline (e.g., Petter, Straub, & Rai 2007; Straub, Boudreau, & Gefen 2004; Straub 1989). With the accumulation of knowledge related to the process of instrument development, it has now become necessary to take a closer look at specific aspects of this process. This paper focuses on construct validity, specifically discriminant validity, and examines some popular methods of supporting this type of validity when using cross-sectional data. We examine strengths and weaknesses of these analysis techniques with a focus on the role of theory and informed interpretation. We highlight the applicability of these techniques by analyzing a sample dataset where we theorize two constructs to be highly correlated. With this paper, we provide both researchers and reviewers a greater understanding of the highlighted discriminant validity analysis techniques

Diagnosing and Managing Online Business-to-Consumer (B2C) Relationships: Toward an eCommerce B2C Relationship Stage Theory

The emergence of eCommerce has provided organizations with an unprecedented opportunity to take advantage of business-to-consumer (B2C) interactions. Generally speaking, relationships move through various stages, when a customer chooses to establish a relationship with a person or an organization. Likewise, when a customer forms an ongoing relationship with an online organization, it progresses through similar stages. Yet, the IT-mediated nature of B2C eCommerce interactions causes the manifestation of these stages to be different from offline B2C interactions. As such, this paper proposes a theoretical framework for examining stages of online B2C relationships, based on Stage Theory. The proposed eCommerce B2C Relationship Stage Theory (eB2C-RST) highlights three stages of eCommerce B2C relationships from the customer’s perspective: Attraction, Build-Up, and Continuance. This theoretical framework provides a foundation for both research and practice in the areas of interface design and online B2C customer relationship management

Prophylactic anticoagulation to prevent venous thromboembolism in traumatic intracranial hemorrhage: a decision analysis

Abstract Introduction Patients with intracranial hemorrhage due to traumatic brain injury are at high risk of developing venous thromboembolism including deep vein thrombosis (DVT) and pulmonary embolism (PE). Thus, there is a trade-off between the risks of progression of intracranial hemorrhage (ICH) versus reduction of DVT/PE with the use of prophylactic anticoagulation. Using decision analysis modeling techniques, we developed a model for examining this trade-off for trauma patients with documented ICH. Methods The decision node involved the choice to administer or to withhold low molecular weight heparin (LMWH) anticoagulation prophylaxis at 24 hours. Advantages of withholding therapy were decreased risk of ICH progression (death, disabling neurologic deficit, non-disabling neurologic deficit), and decreased risk of systemic bleeding complications (death, massive bleed). The associated disadvantage was greater risk of developing DVT/PE or death. Probabilities for each outcome were derived from natural history studies and randomized controlled trials when available. Utilities were obtained from accepted databases and previous studies. Results The expected value associated with withholding anticoagulation prophylaxis was similar (0.90) to that associated with the LMWH strategy (0.89). Only two threshold values were encountered in one-way sensitivity analyses. If the effectiveness of LMWH at preventing DVT exceeded 80% (range from literature 33% to 82%) our model favoured this therapy. Similarly, our model favoured use of LMWH if this therapy increased the risk of ICH progression by no more than 5% above the baseline risk. Conclusions Our model showed no clear advantage to providing or withholding anticoagulant prophylaxis for DVT/PE prevention at 24 hours after traumatic brain injury associated with ICH. Therefore randomized controlled trials are justifiable and needed to guide clinicians

Rapid Monitoring of Bacteria and Fungi aboard the International Space Station (ISS)

Microorganisms within spacecraft have traditionally been monitored with culture-based techniques. These techniques involve growth of environmental samples (cabin water, air or surfaces) on agar-type media for several days, followed by visualization of resulting colonies or return of samples to Earth for ground-based analysis. Data obtained over the past 4 decades have enhanced our understanding of the microbial ecology within space stations. However, the approach has been limited by the following factors: i) Many microorganisms (estimated > 95%) in the environment cannot grow on conventional growth media; ii) Significant time lags (3-5 days for incubation and up to several months to return samples to ground); iii) Condensation in contact slides hinders colony counting by crew; and iv) Growth of potentially harmful microorganisms, which must then be disposed of safely. This report describes the operation of a new culture-independent technique onboard the ISS for rapid analysis (within minutes) of endotoxin and beta-1, 3-glucan, found in the cell walls of gramnegative bacteria and fungi, respectively. The technique involves analysis of environmental samples with the Limulus Amebocyte Lysate (LAL) assay in a handheld device, known as the Lab-On-a-Chip Application Development Portable Test System (LOCAD-PTS). LOCADPTS was launched to the ISS in December 2006, and here we present data obtained from Mach 2007 until the present day. These data include a comparative study between LOCADPTS analysis and existing culture-based methods; and an exploratory survey of surface endotoxin and beta-1, 3-glucan throughout the ISS. While a general correlation between LOCAD-PTS and traditional culture-based methods should not be expected, we will suggest new requirements for microbial monitoring based upon culture-independent parameters measured by LOCAD-PTS

Next Generation LOCAD-PTS Cartridge Development

Future astrobiology exploration missions will require rapid, point-of-use techniques for surface science experiments and contamination monitoring. The Lab-On-a-Chip Application Development (LOCAD) team is developing operational instruments that advance spaceflight technologies to molecular-based methods. Currently, LOCAD-Portable Test System (PTS) is quantifying levels of the bacterial molecule endotoxin onboard the Internatioal Space Station. Future research and development will focus on more sensitive molecular techniques that expand the number of compounds detected to include beta-glucan from fungal cell walls

Technology and the dis-placing of learning in educational futures

Common visions of online education entail radically re-configuring the experience of learning: a technological displacement from the spatial order of classrooms into the more diffuse arena of digital networks. One assumption seems to be that the very spatial order of classrooms creates an undesirably rigid sense of place for schooling, one that is depressingly impervious to change; and that the attendant solution is to escape the realm of the ‘physical’ altogether – into an online realm more supportive of collaboration and free of face-the-front conventions. In the present paper we seek to challenge this oppositional view. We consider several ways in which digital technology can restructure the traditional spaces of educational practice, and identify design dynamics that may be neglected in the wake of ‘virtualisation’. Discussion first highlights two theoretical perspectives that will inform many such designs: namely, situativity and sociality in learning. Three examples are then provided of how digital technology can intersect with learning space design to create novel interpersonal frameworks for learning and to destabilise conventional senses of ‘place’ in those settings. The examples concern, respectively, the organisation of collaborative, expository, and community-based social structures for learning. Those examples represent an illustrative counterpoint to models of online schooling and illustrate a potentially productive synergy between the opportunities afforded by digital technologies, the desires of those who wish to dis-place learning online, and a well-established interest in learning space design

SNAPSHOT USA 2019 : a coordinated national camera trap survey of the United States

This article is protected by copyright. All rights reserved.With the accelerating pace of global change, it is imperative that we obtain rapid inventories of the status and distribution of wildlife for ecological inferences and conservation planning. To address this challenge, we launched the SNAPSHOT USA project, a collaborative survey of terrestrial wildlife populations using camera traps across the United States. For our first annual survey, we compiled data across all 50 states during a 14-week period (17 August - 24 November of 2019). We sampled wildlife at 1509 camera trap sites from 110 camera trap arrays covering 12 different ecoregions across four development zones. This effort resulted in 166,036 unique detections of 83 species of mammals and 17 species of birds. All images were processed through the Smithsonian's eMammal camera trap data repository and included an expert review phase to ensure taxonomic accuracy of data, resulting in each picture being reviewed at least twice. The results represent a timely and standardized camera trap survey of the USA. All of the 2019 survey data are made available herein. We are currently repeating surveys in fall 2020, opening up the opportunity to other institutions and cooperators to expand coverage of all the urban-wild gradients and ecophysiographic regions of the country. Future data will be available as the database is updated at eMammal.si.edu/snapshot-usa, as well as future data paper submissions. These data will be useful for local and macroecological research including the examination of community assembly, effects of environmental and anthropogenic landscape variables, effects of fragmentation and extinction debt dynamics, as well as species-specific population dynamics and conservation action plans. There are no copyright restrictions; please cite this paper when using the data for publication.Publisher PDFPeer reviewe