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The Internet has become impossible to ignore in the past two years. Even people who do not own a computer and have no opportunity to "surf the net" could not have missed the news stories about the Internet, many of which speculate about its effects on the ever-increasing number of people who are on line. Why, then, have communications researchers, historically concerned with exploring the effects of mass media, nearly ignored the Internet? With 25 million people estimated to be communicating on the Internet, should communication researchers now consider this network of networks' a mass medium? Until recently, mass communications researchers have overlooked not only the Internet but the entire field of computer-mediated communication, staying instead with the traditional forms of broadcast and print media that fit much more conveniently into models for appropriate research topics and theories of mass communication.However, this paper argues that if mass communications researchers continue to largely disregard the research potential of the Internet, their theories about communication will become less useful. Not only will the discipline be left behind, it will also miss an opportunity to explore and rethink answers to some of the central questions of mass communications research, questions that go to the heart of the model of source-message-receiver with which the field has struggled. This paper proposes a conceptualization of the Internet as a mass medium, based on revised ideas of what constitutes a mass audience and a mediating technology. The computer as a new communication technology opens a space for scholars to rethink assumptions and categories, and perhaps even to find new insights into traditional communication technologies.tion as a whole, in order to place the new medium within the context of other mass media. Mass media researchers have traditionally organized themselves around a specific communications medium. The newspaper, for instance, is a more precisely defined area of interest than printing-pressmediated communi-This paper looks at the Internet, rather than computer-mediated communica-'For a discussion of what the Internet is, see Request for Comment 1492 athttp:// yoyo.cc.monash.edu/au/-mist/Folklore/RFCl462.html. The "network of networks" description is taken from Krol, 1992. Merrill Morris is a doctoral candidate in the School

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Background: Individuals with left ventricular (LV) hypertrophy and elevated cardiac biomarkers in middle age are at increased risk for the development of heart failure with preserved ejection fraction. Prolonged exercise training reverses the LV stiffening associated with healthy but sedentary aging; however, whether it can also normalize LV myocardial stiffness in patients at high risk for heart failure with preserved ejection fraction is unknown. In a prospective, randomized controlled trial, we hypothesized that 1-year prolonged exercise training would reduce LV myocardial stiffness in patients with LV hypertrophy. Methods: Forty-six patients with LV hypertrophy (LV septum >11 mm) and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide [>40 pg/mL] or high-sensitivity troponin T [>0.6 pg/mL]) were randomly assigned to either 1 year of high-intensity exercise training (n=30) or attention control (n=16). Right-heart catheterization and 3-dimensional echocardiography were performed while preload was manipulated using both lower body negative pressure and rapid saline infusion to define the LV end-diastolic pressure-volume relationship. A constant representing LV myocardial stiffness was calculated from the following: P=S×[Exp {a (V–V 0 )}–1], where “P” is transmural pressure (pulmonary capillary wedge pressure – right atrial pressure), “S” is the pressure asymptote of the curve, “V” is the LV end-diastolic volume index, “V 0 ” is equilibrium volume, and “a” is the constant that characterizes LV myocardial stiffness. Results: Thirty-one participants (exercise group [n=20]: 54±6 years, 65% male; and controls (n=11): 51±6 years, 55% male) completed the study. One year of exercise training increased max by 21% (baseline 26.0±5.3 to 1 year later 31.3±5.8 mL·min –1 ·kg –1 , P <0.0001, interaction P =0.0004), whereas there was no significant change in max in controls (baseline 24.6±3.4 to 1 year later 24.2±4.1 mL·min –1 ·kg –1 , P =0.986). LV myocardial stiffness was reduced (right and downward shift in the end-diastolic pressure-volume relationship; LV myocardial stiffness: baseline 0.062±0.020 to 1 year later 0.031±0.009), whereas there was no significant change in controls (baseline 0.061±0.033 to 1 year later 0.066±0.031, interaction P =0.001). Conclusions: In patients with LV hypertrophy and elevated cardiac biomarkers (stage B heart failure with preserved ejection fraction), 1 year of exercise training reduced LV myocardial stiffness. Thus, exercise training may provide protection against the future risk of heart failure with preserved ejection fraction in such patients. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03476785.