Impact Behavior and Residual Strength of PEEK/CF-Laminated Composites with Various Stacking Sequences.

Carbon fiber-reinforced composites are popular due to their high strength and light weight; thus, the structures demonstrate high performance and specific strength. However, these composites are susceptible to impact damage. The objective of this research was to study the behavior of carbon fiber-reinforced laminates based on a polyetheretherketone (PEEK) matrix with six stacking sequences under static and impact loading. Four-point bending, short-beam bending, drop weight impact, and compression after impact tests were carried out. The results were complemented with digital shearography to estimate the damaged areas. Finite element modeling served to assess the failure mechanisms, such as fiber and matrix failure, in different layers due to tension of compression. Three behavior pattern of layups under drop-weight impact were found: (i)-energy redistribution due to mostly linear behavior (like a trampoline) and thus lower kinetic energy absorption for damage initiation, (ii)-moderate absorption of energy with initiation and propagation of concentrated damage with depressed redistribution of energy in the material, (iii)-moderate energy absorption with good redistribution due to initiation of small, dispersed damage. The results can be used to predict the mechanical behavior of composites with different stacking sequences in materials for proper structural design.

Consumption of Fruits, Vegetables, and Nuts Can Be Increased When Multitasking with Screen Devices.

Past research shows that people overconsume energy-dense, nutrient-poor (EDNP) foods when they are not paying attention to environmental cues that encourage consumption. Very little is known about the mindless consumption of nutritious foods (herein referred to as preferred foods). Using dual-processing, limited capacity, and mood management models and theories, this study explored whether people misreport the selection of preferred and EDNP foods under differing levels of distraction created by screen media device use. Participants freely grazed on EDNP and preferred snacks while either watching TV (one screen) or multitasking with two or three screens (TV, iPod, laptop computer). Participants under-reported the number of preferred foods they selected for consumption in the three-screen multitasking conditions more than in one- and two-screen conditions. They under-reported the selection of preferred snacks more than EDNP snacks in the three-screen conditions. The under-reporting of snack selection was greater in one three-screen condition (TV+texting+online shopping) (which was evaluated as highly arousing and pleasant), than in the other three-screen condition (TV+texting+online reading) (which was rated as highly arousing but less pleasant). Compared to participants with weaker health beliefs, those with stronger beliefs about healthy lifestyle said they were more rational in selecting preferred snacks. Findings show that people sometimes eat greater amounts of preferred foods than they realize, when they are multitasking with screen devices. By surrounding oneself with snack-size fruits, vegetables, and nuts in multitasking situations, mindless eating could be a powerful nudge to facilitate greater consumption of preferred foods to combat health concerns.

Thiophene-2-carboxamide derivatives of anthraquinone: A new potent antitumor chemotype.

The anthraquinone scaffold has long been known as a source of efficacious antitumor drugs. In particular, the various chemical modifications of the side chains in this scaffold have yielded the compounds potent for the wild type tumor cells, their counterparts with molecular determinants of altered drug response, as well as in vivo settings. Further exploring the chemotype of anticancer heteroarene-fused anthraquinones, we herein demonstrate that derivative of anthra[2,3-b]thiophene-2-carboxamide, (compound 8) is highly potent against a panel of human tumor cell lines and their drug resistant variants. Treatment with submicromolar or low micromolar concentrations of 8 for only 30 min was sufficient to trigger lethal damage of K562 chronic myelogenous leukemia cells. Compound 8 (2.5 µM, 3-6 h) induced an apoptotic cell death as determined by concomitant activation of caspases 3 and 9, cleavage of poly(ADP-ribose) polymerase, increase of Annexin V/propidium iodide double stained cells, DNA fragmentation (subG1 fraction) and a decrease of mitochondrial membrane potential. Neither a significant interaction with double stranded DNA nor strong inhibition of the DNA dependent enzyme topoisomerase 1 by 8 were detectable in cell free systems. Laser scanning confocal microscopy revealed that some amount of 8 was detectable in mitochondria as early as 5 min after the addition to the cells; exposure for 1 h caused significant morphological changes and clustering of mitochondria. The bioisosteric analog 2 in which the thiophene ring was replaced with furan was less active although the patterns of cytotoxicity of both derivatives were similar. These results point at the specific role of the sulfur atom in the antitumor properties of carboxamide derivatives of heteroarene-fused anthraquinone.

Smartphone Users' Persuasion Knowledge in the Context of Consumer mHealth Apps: Qualitative Study.

BACKGROUND: Persuasion knowledge, commonly referred to as advertising literacy, is a cognitive dimension that embraces recognition of advertising, its source and audience, and understanding of advertisers' persuasive and selling intents as well as tactics. There is little understanding of users' awareness of organizations that develop or sponsor mobile health (mHealth) apps, especially in light of personal data privacy. Persuasion knowledge or recognition of a supporting organization's presence, characteristics, competencies, intents, and persuasion tactics are crucial to investigate because app users have the right to know about entities that support apps and make informed decisions about app usage. The abundance of free consumer mHealth apps, especially those in the area of fitness, often makes it difficult for users to identify apps' dual purposes, which may be related to not only helping the public manage health but also promoting the supporting organization itself and collecting users' information for further consumer targeting by third parties. OBJECTIVE: This study aims to investigate smartphone users' awareness of mHealth apps' affiliations with 3 different types of supporting organizations (commercial, government, and nonprofit); differences in users' persuasion knowledge and mHealth app quality and credibility evaluations related to each of the 3 organization types; and users' coping mechanisms for dealing with personal information management within consumer mHealth apps. METHODS: In-depth semistructured interviews were conducted with 25 smartphone users from a local community in midwestern United States. Interviews were thematically analyzed using inductive and deductive approaches. RESULTS: Participants indicated that their awareness of and interest in mHealth app-supporting organizations were secondary to the app's health management functions. After being probed, participants showed a high level of persuasion knowledge regarding the types of app-supporting organizations and their promotional intents. They thought that commercial companies sponsored mHealth apps mostly as entertainment tools, whereas noncommercial entities sponsored mHealth apps for users' education. They assigned self-promotional motives to commercial organizations; however, they associated commercial mHealth apps with good quality and functioning. Noncommercial entities were perceived as more credible. Participants were concerned about losing control over personal information within mHealth apps supported by different organizations. They used alternative digital identities to protect themselves from privacy invasion and advertising spam. They were willing to trade some personal information for high-quality commercial mHealth apps. There was a sense of fatalism in discussing privacy risks linked to mHealth app usage, and some participants did not perceive the risks to be serious. CONCLUSIONS: The discussion of and recommendations for the safe and ethical use of mHealth apps associated with organizations' promotional strategies and personal data protection are provided to ensure users' awareness of and enhanced control over digitalized personal information flows. The theoretical implications are discussed in the context of the Persuasion Knowledge Model and dual-processing theories.

Habit Formation in Wearable Activity Tracker Use Among Older Adults: Qualitative Study.

BACKGROUND: Wearable activity trackers are popular devices used to motivate behavior change. Wearable activity trackers are especially beneficial for encouraging light physical activity such as walking, which is an ideal behavior for older adults or individuals who cannot be physically active at moderate and vigorous levels. A common problem is that people do not continue to use these wearable devices, with initial behavioral change gains eroding as people disengage. Limited research is available regarding the continued use of wearable activity trackers. The habit formation literature may provide insights into the long-term use of wearables and other health informatics devices. OBJECTIVE: This study aims to uncover the mechanism underlying the long-term continued use of wearable devices among older adults through the theoretical lens of habit formation. METHODS: In-depth interviews were conducted with 20 participants who were aged 65 years or older and had used wearable activity trackers for more than 6 months to understand their experiences and the strategies they employed to support continued use. RESULTS: Thematic analysis of data revealed 8 themes related to habit formation, including aspects in initiation and goal setting, use of contextual cues, action planning, and coping planning. Long-term users tended to have meaningful initiation of wearable activity trackers. They usually started with a small behavioral change goal and gradually increased it. They used consistent time and locational cues to make the use of wearable activity trackers routine. Long-term users also used creative contextual cues and reminders to facilitate action planning, engaged in coping planning to deal with anticipated problems, and had a positive mindset and inventive strategies for managing unfulfillment and lapses. CONCLUSIONS: The results of this qualitative study of long-term users of wearable activity trackers suggest specific ways to enhance long-term habit formation among older adults. These best practices by long-term users can inform the future design of technology-based behavior interventions.

Factors Associated with Older Adults' Long-Term Use of Wearable Activity Trackers.

Background: Wearable activity trackers (WATs) have the potential to improve older adults' health; yet, many adopters of WATs are not able to use them on a long-term basis. Methods: A survey was conducted with an online panel of adults 65 and older (N = 214) to explore factors associated with long-term use of WATs, including initial adoption motivations, usage patterns, as well as differences in sociodemographic factors, health status, and activity levels. Results: Results from the logistic regression analysis indicated that being a long-term WAT user was significantly associated with using a wider variety of WAT functions, wearing WAT every day, being female, exercising more frequently, having higher education, not engaging in step count competition, and not having chronic conditions. Conclusions: Understanding long-term use of WATs among older adults is important given that this technology is prone to be abandoned quickly after initial adoption and such abandonment negates its potential in supporting long-term health behavior change. Findings of this study will inform innovative WAT designs that afford long-term use and offer helpful strategies for future interventions using WATs among older adults.

Contrary to Myth, Older Adults Multitask With Media and Technologies, But Studying Their Multitasking Behaviors Can Be Challenging.

BACKGROUND AND OBJECTIVES: The study's objective was to explore older adults' (aged 65 or older) descriptions of behavior related to multitasking with traditional and newer media/information and communication technologies (ICTs) and perceived benefits of such behavior, along with older adults' preference for research methods used to study their multitasking behaviors. Employing common media-use measures that heavily rely on self-reporting in populations of older adults is challenging, especially given that patterns of media/ICT use are becoming increasingly complex. Cumulatively, people spend more time using media than they are aware of because of the tendency to use some forms of media simultaneously. As cognitive ability deteriorates with age, self-reported recollection of complex patterns of media/ICT use, such as multitasking, among older adults increases the threat to data accuracy.Research Design and Methods: Twenty-eight community-dwelling older adults in a Midwestern U.S. state participated in in-depth interviews (average length was 40 minutes) to discuss their use of traditional and newer media/technologies in combination with other activities and outline methods researchers should use to study such behaviors. RESULTS: Participants reported they engaged in multitasking behaviors similar to those of younger generations, with the difference in the higher extent of using traditional media and ICTs. They talked about multitasking with radio and television for "background noise" as being a rewarding experience. They perceived the effects of multitasking to be detrimental to attention and performance and attributed this media-use habit to individual psychological and demographic differences. They preferred ethnographic observation and keeping a paper-and-pencil diary as research methods to study multitasking among their peers. Data-logging methods were less popular because they raised privacy concerns among interviewees. DISCUSSION AND IMPLICATIONS: Different types of traditional and newer media and technologies could be used differently in situations that require older adults to focus, relax, or be efficient. The findings suggest that future researchers strive for a compromise between data access and data accuracy when they select a research method to study media use among older adults.

The Use of Wearable Activity Trackers Among Older Adults: Focus Group Study of Tracker Perceptions, Motivators, and Barriers in the Maintenance Stage of Behavior Change.

BACKGROUND: Wearable activity trackers offer the opportunity to increase physical activity through continuous monitoring. Viewing tracker use as a beneficial health behavior, we explored the factors that facilitate and hinder long-term activity tracker use, applying the transtheoretical model of behavior change with the focus on the maintenance stage and relapse. OBJECTIVE: The aim of this study was to investigate older adults' perceptions and uses of activity trackers at different points of use: from nonuse and short-term use to long-term use and abandoned use to determine the factors to maintain tracker use and prevent users from discontinuing tracker usage. METHODS: Data for the research come from 10 focus groups. Of them, 4 focus groups included participants who had never used activity trackers (n=17). These focus groups included an activity tracker trial. The other 6 focus groups (without the activity tracker trial) were conducted with short-term (n=9), long-term (n=11), and former tracker users (n=11; 2 focus groups per user type). RESULTS: The results revealed that older adults in different tracker use stages liked and wished for different tracker features, with long-term users (users in the maintenance stage) being the most diverse and sophisticated users of the technology. Long-term users had developed a habit of tracker use whereas other participants made an effort to employ various encouragement strategies to ensure behavior maintenance. Social support through collaboration was the primary motivator for long-term users to maintain activity tracker use. Short-term and former users focused on competition, and nonusers engaged in vicarious tracker use experiences. Former users, or those who relapsed by abandoning their trackers, indicated that activity tracker use was fueled by curiosity in quantifying daily physical activity rather than the desire to increase physical activity. Long-term users saw a greater range of pros in activity tracker use whereas others focused on the cons of this behavior. CONCLUSIONS: The results suggest that activity trackers may be an effective technology to encourage physical activity among older adults, especially those who have never tried it. However, initial positive response to tracker use does not guarantee tracker use maintenance. Maintenance depends on recognizing the long-term benefits of tracker use, social support, and internal motivation. Nonadoption and relapse may occur because of technology's limitations and gaining awareness of one's physical activity without changing the physical activity level itself.

A Pilot Study Examining the Effects of Educational Setting and Stress on Multitasking Among Medical Students.

This study examines multitasking with media and technology among medical students across four learning contexts (lecture, lab, team-based learning, and homework) and whether stress moderates the relationship between multitasking and academic performance. The proliferation of technology simultaneously used for learning, entertainment, and socialization facilitates multitasking in learning environments. There is comparatively little research on multitasking behavior among medical students. Data were collected using a survey distributed online to four cohorts of an allopathic medical school to examine the relationship of multitasking and academic performance using both descriptive and correlational analyses of multitasking behavior in each of the four learning contexts. A moderation analysis was used to investigate the role of stress in this relationship. Lower multitasking was reported as learning contexts became more active (e.g., lecture versus lab). Some respondents, however, appeared resilient to the changing environment, maintaining high levels of multitasking. In the low multitasking environment of lab, respondents with high levels of stress, who multitasked heavily, reported better academic performance. Approaches to multitasking must account for learning environments and the individual propensities of students. Additionally, some forms of multitasking may not be counterproductive to learning, but the boundaries between productive and counterproductive multitasking are difficult to distinguish.

Reading About the Flu Online: How Health-Protective Behavioral Intentions Are Influenced by Media Multitasking, Polychronicity, and Strength of Health-Related Arguments.

As health organizations increasingly use the Internet to communicate medical information and advice (Shortliffe et al., 2000; World Health Organization, 2013), studying factors that affect health information processing and health-protective behaviors becomes extremely important. The present research applied the elaboration likelihood model of persuasion to explore the effects of media multitasking, polychronicity (preference for multitasking), and strength of health-related arguments on health-protective behavioral intentions. Participants read an online article about influenza that included strong and weak suggestions to engage in flu-preventive behaviors. In one condition, participants read the article and checked Facebook; in another condition, they were exposed only to the article. Participants expressed greater health-protective behavioral intentions in the media multitasking condition than in the control condition. Strong arguments were found to elicit more positive behavioral intentions than weak arguments. Moderate and high polychronics showed greater behavioral intentions than low polychronics when they read the article in the multitasking condition. The difference in intentions to follow strong and weak arguments decreased for moderate and high polychronics. The results of the present study suggest that health communication practitioners should account for not only media use situations in which individuals typically read about health online but also individual differences in information processing, which puts more emphasis on the strength of health-protective suggestions when targeting light multitaskers.

Effects of distracting ads and cognitive control on the processing of online news stories with stereotype-related information.

An experiment (N=123) examined how individuals cognitively process online news stories depicting African-American characters with stereotype-consistent and -inconsistent attributes and whether distracting online ads interfere with story processing. Two cognitive control functions, updating and inhibition, were predicted to moderate the effects of distracting ads. Recall of characters' attributes and overall characters' description were included in the study as dependent measures. Findings indicated that distracting online ads hinder recall of information about and descriptions of story characters. Inhibition and updating affect dependent measures and moderate the effects of distracting online ads on characters' descriptions.

Exploring the motivations of Facebook use in Taiwan.

The current study explored the motivations of online social network use among a sample of the general population in Taiwan (N=4,346). It investigated how seven different motivations to use Facebook predicted the intensity of Facebook use and content-generation behaviors on Facebook. Results showed that the motivation to use Facebook for posting and viewing status updates was the strongest predictor of Facebook intensity, while the motivation to view and share photographs was the strongest predictor of content-generation behavior on the site. Results are discussed in terms of expanding motivations to use Facebook to the study of social networking sites and other new and social media.