3,704 research outputs found

    Why Tie A Product Consumers Do Not Use?

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    This paper provides a new explanation for tying that is not based on any of the standard explanations -- efficiency, price discrimination, and exclusion. Our analysis shows how a monopolist sometimes has an incentive to tie a complementary good to its monopolized good in order to transfer profits from a rival producer of the complementary product to the monopolist. This occurs even when consumers -- who have the option to use the monopolist's complementary good -- do not use it. The tie is profitable because it alters the subsequent pricing game between the monopolist and the rival in a manner favorable to the monopolist. We show that this form of tying is socially inefficient, but interestingly can arise only when the tie is socially efficient in the absence of the rival producer. We relate this inefficient form of tying to several actual examples and explore its antitrust implications.

    Book Review

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    Reviewing Philip J. Hermann, Better Settlements Through Leverage, Acqueduct Books, 196

    What Makes a Great Science Experience? A Program Planning Checklist for Educators

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    The Science & Technology Program Work Team at Cornell University wanted to know what constitutes a fun, exciting, and successful science-based learning experience for young people. In 2002, 4-H Educators and youth were engaged in the Concept System process that generated 144 unique ideas. These ideas were distilled into 15 clusters, all of which linked to three principal elements of program design: Content, Context, and Delivery. Those results were translated into a checklist for planning science programs, available at . In 2005 and 2006, the team recommended adapting it to other interactive learning experiences and for program evaluation

    Nanosecond optical imaging spectroscopy of an electrothermal radiofrequency plasma thruster plume

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    Nanosecond optical imaging spectroscopy is employed to investigate the spatio-temporal dynamics of the plasma plume expanding from a 4.2 mm-diameter, 20 mm-long cylindrical capacitively coupled electrothermal radiofrequency (rf) driven thruster using 10 W of power at 12.50 MHz and an argon pressure of 1.5 Torr. On-axis, the plume exhibits four distinct peaks of optical emission intensity within the rf period. The plume has a spherical shape with a transient radial extension (during half of the rf cycle) at the thruster exit plane due to an rf current to ground when the grounded electrode acts as an anode

    Formation of spatially periodic fronts of high-energy electrons in a radio-frequency driven surface microdischarge

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    The generation of spatially periodic fronts of high-energy electrons (>13.48 eV) has been investigated in a radio-frequency surface microdischarge in atmospheric-pressure argon. Optical emission spectroscopy is used to study the Ar I 2p1−1s2 transition surrounding a filamentary microdischarge, both spatially and with respect to the phase of the applied voltage. The formation of excitation fronts, which remain at a constant propagation distance throughout the RF cycle and for the duration of the pulse, may be explained by a localized increase in the electric field at the tip of surface-charge layers that are deposited during the extension phase

    Wave-Measuring Performance Characteristics of Spoondrift Spotter

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    Spoondrift Spotter represents a state-of-the-art wave measurement buoy developed by Spoondrift (www.spoondrift.co) and supported by funding from the Advanced Research Projects Agency – Energy (ARPA-E). A low-cost buoy platform like Spotter enables a range of new applications. For instance, coherent arrays of Spotters can support adaptive tuning of marine and hydrokinetic energy devices. In general, the availability of high-fidelity wave measurements can help support wave assessments for a variety of commercial, military, operational, academic, and recreational users

    Smartphone Ownership and Interest in Mobile Health Technologies for Self-care Among Patients With Chronic Heart Failure: Cross-sectional Survey Study

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    BACKGROUND: Heart failure (HF) is a highly prevalent chronic condition that places a substantial burden on patients, families, and health care systems worldwide. Recent advances in mobile health (mHealth) technologies offer great opportunities for supporting many aspects of HF self-care. There is a need to better understand patients\u27 adoption of and interest in using mHealth for self-monitoring and management of HF symptoms. OBJECTIVE: The purpose of this study is to assess smartphone ownership and patient attitudes toward using mHealth technologies for HF self-care in a predominantly minority population in an urban clinical setting. METHODS: We conducted a cross-sectional survey of adult outpatients (aged \u3e /=18 years) at an academic outpatient HF clinic in the Midwest. The survey comprised 34 questions assessing patient demographics, ownership of smartphones and other mHealth devices, frequently used smartphone features, use of mHealth apps, and interest in using mHealth technologies for vital sign and HF symptom self-monitoring and management. RESULTS: A total of 144 patients were approached, of which 100 (69.4%) participated in the study (63/100, 63% women). The participants had a mean age of 61.3 (SD 12.25) years and were predominantly Black or African American (61/100, 61%) and Hispanic or Latino (18/100, 18%). Almost all participants (93/100, 93%) owned a cell phone. The share of patients who owned a smartphone was 68% (68/100). Racial and ethnic minorities that identified as Black or African American or Hispanic or Latino reported higher smartphone ownership rates compared with White patients with HF (45/61, 74% Black or African American and 11/18, 61% Hispanic or Latino vs 9/17, 53% White). There was a moderate and statistically significant association between smartphone ownership and age (Cramer V [PhiC]=0.35; P \u3c .001), education (PhiC=0.29; P=.001), and employment status (PhiC=0.3; P=.01). The most common smartphone features used by the participants were SMS text messaging (51/68, 75%), internet browsing (43/68, 63%), and mobile apps (41/68, 60%). The use of mHealth apps and wearable activity trackers (eg, Fitbits) for self-monitoring of HF-related parameters was low (15/68, 22% and 15/100, 15%, respectively). The most popular HF-related self-care measures participants would like to monitor using mHealth technologies were physical activity (46/68, 68%), blood pressure (44/68, 65%), and medication use (40/68, 59%). CONCLUSIONS: Most patients with HF have smartphones and are interested in using commercial mHealth apps and connected health devices to self-monitor their condition. Thus, there is a great opportunity to capitalize on the high smartphone ownership among racial and ethnic minority patients to increase reach and enhance HF self-management through mHealth interventions

    Upwelling couples chemical and biological dynamics across the littoral and pelagic zones of Lake Tanganyika, East Africa

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    We studied the effects of upwelling on nutrient and phytoplankton dynamics in the pelagic and littoral zones of Lake Tanganyika near Kigoma, Tanzania. During the dry season of 2004, a rise in the thermocline and sudden drop in surface water temperatures indicated a substantial upwelling event. Increases in concentrations of nitrate, soluble reactive phosphorus, and silica in the surface waters occurred simultaneously after the temperature drop. Within days, chlorophyll a concentrations increased and remained elevated, while inorganic nutrient concentrations returned to preupwelling levels and organic nutrient concentrations peaked. We observed parallel temporal patterns of water temperature, nutrient concentrations, and phytoplankton chlorophyll in both the pelagic and the littoral zones, demonstrating that upwelling strongly affects the nearshore ecosystem as well as the pelagic zone. Concurrent records from 12 littoral sites indicated spatial variation in the timing, magnitude, and biological response to upwelling. There was no discernable latitudinal pattern in the timing of upwelling, suggesting that mixing did not result from a progressive wave. Our monitoring, as well as other multiyear studies, suggests that dry-season upwelling occurs during most years in northern Lake Tanganyika. The observed sensitivity of littoral nutrients and phytoplankton to upwelling suggests that reductions in upwelling due to global climate change could strongly affect the dynamics of the spectacular nearshore ecosystem of Lake Tanganyika, as has been proposed for the pelagic zone
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