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981.
Leo Kivijarv Ph.D. 《Publishing Research Quarterly》2002,18(2):12-22
Conclusion Convergence is a very exciting model and one that holds, unforeseen opportunities. However in the current economic environment,
the investment community is hesitant to recommend that communications companies devote many resources in that area. The convergence
mode must prove that it can generate revenue and profits. Yet, it is limited to an advertising-supported model—a part of the
communications industry that has struggled during the past, year due to the recession. The increased advertising revenue that
would be generated by the convergence model is tainted—most likely taking advertising share away from the traditional media
segments that are supporting the model. Tied to the convergence model is a high dependency on the Internet. Internet advertising
is not local. In addition, financial data clearly illustrates that the Internet has caused profit margins to decrease substantially,
something that the traditional media company supporting the convergence model can not allow to happen. Finally, FCC deregulation
with regards to television station cap restrictions, cable system operators owning broadcasters in the same market, and cross
ownership of newspapers and television stations in the same market, will most likely have a negative impact on the convergence
model.
If a communications company should decide to go forward with convergence, there are five rules that should be followed:
The essay is based on a presentation made by Dr. Kivijarv at convergece: The Tour, a four-day conference sponsored by The American Press Institute. The purpose of the conference is to analyze the various
issues that communications companies should consider before attempting to build multimedia news operations that consolidate
newspaper, television, wired cable, and/or Internet divisions in a specific market. Dr. Kivijarv's presentation occurred on
the final day of the conference and spoke to the investment community's financial concerns. Veronis Suhler Stevenson publishes,
two of the leading annual reports on the communications industry—the Communications Industry Forecast and the Communications Industry Report. A majority of the data used in the presentation and this essay come from those reports and Dr. Kivijarv, as the Director
of Research & Publications at Veronis Suhler Stevenson, serves as the editor of the two reports. 相似文献
1. | Use personnel and technology efficiently |
2. | Extend brand awareness of pre-existing communications products |
3. | Offer cross-media advertising packages |
4. | Return users to traditional media outlets |
5. | BE PROFITABLE QUICKLY!39. |
982.
Fatigue represents a reduction in the capability of muscle to generate force. The aim of the present study was to establish the effects of exercise that simulates the work rate of competitive soccer players on the strength of the knee extensors and knee flexors. Thirteen amateur soccer players (age 23.3+/-3.9 years, height 1.78+/-0.05 m, body mass 74.8+/-3.6 kg; mean+/-s) were tested during the 2000-2001 soccer season. Muscle strength of the quadriceps and hamstrings was measured on an isokinetic dynamometer. A 90 min soccer-specific intermittent exercise protocol, incorporating a 15 min half-time intermission, was developed to provide fatiguing exercise corresponding in work rate to a game of soccer. The exercise protocol, performed on a programmable motorized treadmill, consisted of the different intensities observed during soccer match-play (e.g. walking, jogging, running, sprinting). Muscle strength was assessed before exercise, at half-time and immediately after exercise. A repeated-measures analysis of variance showed significant reductions (P < 0.001) in peak torque for both the quadriceps and hamstrings at all angular velocities (concentric: 1.05, 2.09, 5.23 rad x s(-1); eccentric: 2.09 rad x s(-1)). The peak torque of the knee extensors (KE) and knee flexors (KF) was greater before exercise [KE: 232+/-37, 182+/-34, 129+/-27, 219+/-41 N x m at 1.05, 2.09 and 5.23 rad x s(-1) (concentric) and 2.09 rad x s(-1) (eccentric), respectively; KF: 126+/-20, 112+/-19, 101+/-16, 137+/-23 N x m] than at half-time (KE: 209+/-45, 177+/-35, 125+/-36, 214+/-43 N x m; KF: 114+/-31, 102+/-20, 92+/-15, 125+/-25 N x m) and greater at half-time than after exercise (KE: 196+/-43, 167+/-35, 118+/-24, 204+/-43 N x m; KF: 104+/-25, 95+/-21, 87+/-13, 114+/-27 N x m). For the hamstrings:quadriceps ratio, significant changes were found (P < 0.05) for both legs, the ratio being greater before than after exercise. For fast:slow speed and left:right ratios, no significant changes were found. We conclude that there is a progressive reduction in muscle strength that applies across a range of functional characteristics during exercise that mimics the work rate in soccer. 相似文献
983.
Grant SJ Oommen G McColl G Taylor J Watkins L Friel N Watt I McLean D 《Journal of sports sciences》2003,21(12):1009-1015
Different methods of ball carrying can be used when a player runs with the ball in rugby union. We examined how three methods of ball carrying influenced sprinting speed: using both hands, under the left arm and under the right arm. These methods were compared with running without the ball. Our aim was to determine which method of ball carrying optimizes sprinting speed. Altogether, 48 rugby union players (age 21 +/- 2 years, height 1.83 +/- 0.1 m, body mass 85.3 +/- 12 kg, body fat 14 +/- 5%; mean +/- s) were recruited. The players performed twelve 30-m sprints in total (each player performed three trials under each of three methods of carrying the ball and sprinting without the ball). The design of the study was a form of Latin rectangle, balanced across the trial order for each of the methods and for pairwise combinations of the methods in blocks of four per trial. Each sprint consisted of a 10-m rolling start, followed by a 20-m timed section using electronic timing gates. Compared with sprinting 20 m without the ball (2.58 +/- 0.16 s), using both hands (2.62 +/- 0.16 s) led to a significantly slower time (P < 0.05). Sprinting 20 m with the ball under the left arm (2.61 +/- 0.15 s) or under the right arm (2.60 +/- 0.17 s) was significantly quicker than when using 'both hands' (P < 0.05), and both these methods were significantly slower than when running without the ball (P < 0.05). Accordingly, running with the ball in both hands led to the greatest decrement in sprinting performance, although carrying the ball under one arm also reduced the players' sprinting ability. Our results indicate that to gain a speed advantage players should carry the ball under one arm. 相似文献
984.
Three studies are reported of children and youth aged 11-19 years (n = 3478) examining the nature of beliefs about athletic ability. Drawing on related research in academic, moral and stereotyping domains, development of a psychometric instrument assessing athletic ability beliefs is detailed. Support was found for a multidimensional hierarchical structure that is invariant across age and gender. Confirmatory factor analysis revealed a structure comprising two higher-order factors of entity and incremental beliefs underpinned by beliefs that athletic ability is stable and a gift (entity), and is open to improvement and can be developed through learning (incremental). Incremental beliefs, indirectly through a task goal orientation, and entity beliefs directly, predicted self-reported amotivation towards physical education and sport. On the other hand, enjoyment of physical activity in youth was predicted directly by task orientation and incremental beliefs. Predictions concerning the moderating role of perceived competence were not supported. Our findings highlight the importance of ability beliefs and goals in understanding the determinants of physical activity in children and youth. 相似文献
985.
Simulated tennis matchplay in a controlled environment 总被引:2,自引:2,他引:0
The aim of this study was to develop an exercise protocol to simulate tennis matchplay on a 'category 2' surface. Match analyses were used to form the basis for the design of the protocol. The protocol involved playing against a tennis ball serving machine. Part A of the protocol comprised 92 min 46 s of simulated tennis matchplay; Part B consisted of continuous hitting to the point of 'volitional fatigue' or when the required hitting frequency for two consecutive ball feeds could no longer be maintained. Ten elite tennis players (5 males, 5 females) volunteered to participate in the study, which was performed on an indoor tennis court (Matchplay, En-Tout-Cas). Their age, body mass and estimated maximal oxygen uptake were as follows: males, 21.7 +/- 1.0 years, 73.6 +/- 2.6 kg and 58.0 +/- 1.7 ml x kg(-1) x min(-1), respectively; females, 21.9 +/- 1.3 years, 62.3 +/- 2.0 kg and 42.2 +/- 0.7 ml x kg x min(-1), respectively (mean +/- sx). Heart rate, change in body mass and time to volitional fatigue were monitored. The heart rate responses of the participants to the simulated matchplay (range: 140-157 beats x min(-1), 73-81% peak heart rate) were consistent with the results of previous studies, for 'actual' matchplay. This protocol was successful in simulating similar physiological responses in Part A to 'actual' matchplay on a 'category 2' surface, in a controlled environment; it was also a sensitive evaluation tool of skilled performance in Part B. The current protocol may be used as a baseline protocol for studying the influence of, for example, training and dietary intervention on performance. 相似文献
986.
In human movement and sports science, manipulations of perception and action are common and often comprise the control of events, such as opening or closing liquid crystal goggles. Most of these events are externally controlled, independent of the actions of the participants. Less common, although sometimes desirable, are event manipulations that are dependent on the unconstrained movements of participants. As an example, we describe a method we used previously to manipulate vision of basketball jump shooters on the basis of on-line registration of their own movements. The shooters wore liquid crystal goggles that opened or shut as a function of specific kinematic features of these movements. The novel aspect of this method is that the criteria for detecting movement patterns and performing the appropriate manipulations are adjustable to the specific sport context and the complexity and variations of the unconstrained movements. The method was implemented as a finite state machine: a computer system that can be used for pattern recognition. We discuss this method, how it works and the potential it has for studying perceptual-motor skills in sport. Furthermore, the results of the basketball experiment are briefly summarized and complemented with new analyses. 相似文献
987.
The coronal and sagittal plane leg movements of 24 experienced male cyclists were assessed using video analysis while cycling on a Kingcycle windload simulator. The cyclists were grouped into those with a history of injury and an asymptomatic group on the basis of self-reported injury status. The ages, cycling experience, competition distances and competition speeds of the two groups were compared using Student's t-test. No significant differences (P < 0.05) were found for any of these variables. The maximum and minimum shank adduction, shank adduction velocities, knee flexion and ankle dorsiflexion values were also compared using Student's t-test. Significant differences were found at the point of maximum adduction (1.9 degrees; P = 0.019) and minimum dorsiflexion (4.9 degrees; P = 0.014). These differences indicated more dorsiflexion and greater abduction on the part of the symptomatic cyclists, supporting previous research that found that cyclists with a history of injury differ from those without a history of injury in the coronal plane leg movement patterns they adopt. Also, the most extreme medial position of the knee relative to the ankle occurred during knee extension. This supports the potential injury mechanism proposed by Francis (1986), which had previously only been examined using coronal plane kinematics. 相似文献
988.
Mechanisms of attentional cueing during observational learning to facilitate motor skill acquisition
We examined the effectiveness of different cueing conditions during observational learning of a soccer accuracy pass. Sixty participants (30 males, 30 females) were randomly assigned and stratified by sex into one of six groups: discovery learning, verbal instruction, video model with visual cues, video model with verbal cues, video model with visual and verbal cues, and video model only. Each participant completed eight blocks of 10 trials each, with trial blocks 1 and 2 representing the practice phase (no manipulation), trial blocks 3, 4, 5 and 6 the acquisition phase (manipulation administered) and trial blocks 7 and 8 the retention phase (24 h after acquisition, with no manipulation). Absolute error, variable error and kicking form were recorded. The results indicated that those who used video modelling with visual and verbal cues collectively displayed less error and more appropriate form across acquisition and retention trial blocks compared with other groups. Our findings suggest that verbal information in addition to visual cues enhances perceptual representation and retention of modelled activities to improve task reproduction capabilities. Future research directions are proposed with implications for both direct and indirect perception accounts of skill acquisition through observed behaviours. 相似文献
989.
The aims of this study were to compare the aerobic energy cost of four 'on-snow' skating techniques in cross-country skiing and to examine the relationships between performance and aerobic energy cost. Twelve male skiers from recreational to national standard performed four level skating trials of 6 min duration in random order, each at the same submaximal velocity but with a different skating technique: (1) 'offset' (V1), using a double asymmetrical and asynchronous pole plant as weight is transferred to one ski; (2) 'two-skate' (V2A), where the pole plant is symmetrical; (3) 'one-skate' (V2), where there is a pole plant as weight is transferred to each ski; and (4) 'conventional', without poles. Oxygen uptake (VO2), pulmonary ventilation, the respiratory exchange ratio and heart rate were measured using a K4(b2) portable gas analyser. The aerobic energy cost (VO2/mean speed) and heart rate were higher (P < 0.05) in the one-skate than in the offset condition. This may be explained by the greater and more efficient use of the upper body and the lower variation in centre of gravity velocity in the offset condition. The aerobic energy cost was 5-9% higher (P < 0.01) in the conventional than in the other techniques, probably because of the shorter duration of propulsive forces within a cycle in the conventional skating condition. Moreover, in ski skating, the mechanical efficiency (propulsive forces/total forces) was shown to be higher in the upper than in the lower limbs. The correlation coefficient between performance and aerobic energy cost was significant in the two-skate (r = 0.68, P = 0.02), one-skate (r = 0.72, P = 0.01) and conventional (r = 0.62, P = 0.04) conditions, but not in the offset condition (r = 0.50, P = 0.10). Our results stress the importance of the upper body component in cross-country skiing and that the aerobic energy cost discriminates between skiers of different standards. 相似文献
990.
Dannecker EA Hausenblas HA Connaughton DP Lovins TR 《Research quarterly for exercise and sport》2003,74(3):236-247
The purpose of this study was to examine evidence for the validity of a stages of change measure of the Transtheoretical Model for exercise behavior. Participants were 152 university students (53.3% women, 71.6% Caucasian, M age = 19.18 years) who completed processes of change, self-efficacy, decisional balance, stages of change, and exercise behavior questionnaires as well as a maximal treadmill test. Participants in the action and maintenance stages had the highest strenuous (PC/C/P < A/M) and moderate (PC/C < A/M) self-reported exercise behavior. Those in the maintenance stage had the highest estimated aerobic fitness (PC/P < MA). The differences between the early stages (PC, C, and P) and the later stages (A and M) as described by the first function were primarily due to the behavioral process of change. The differences between the extreme stages (PC and M) and the middle stages (C, P, and A) were due to the experiential processes of change and the pros of decisional balance. The hypothesized patterns of stage differences were partially supported. Failure to obtain full support may have been due to methodological issues or inherent difficulties in detecting evidence for the validity of stages of change measures. 相似文献