The Effects of Applied Grip Force, Frequency and Duration on Ratings of Perceived Exertion

This study investigates the interactions of various combinations of frequency and duration that result in the same duty cycle at a given applied grip force (measured in % maximum voluntary contraction (MVC)) to determine their relative effect on perceived exertion. Eight female subjects (median age 20.5 years) performed 27 randomized trials containing combinations of dynamic grips, performing each combination twice. Each session contained three 25 minute trials, with a minimum of 12 minutes of rest between trials. The design used a 3x3x3 factorial protocol: i) 3 grip forces (10%, 25%, 40%) ii) 3 duty cycles (25%, 50%, 75%) iii) 3 durations (1, 4, 7 seconds). Subjects were asked to rate their level of perceived exertion every 2.5 minutes, throughout the entire 25 minute trial (or until it became too difficult to continue) using the Borg CR-10 scale (Borg, 1998). Although force seems to have the strongest effect on increased Borg CR-10 ratings (of all the tested factors), it was only significant as a main effect in a model that tested %MVC * Duty Cycle. The interaction of factors was statistically significant (p ≤ 0.01) for both models tested: i) % MVC * Duty Cycle ii) % MVC * Frequency * Duration. The model which separated frequency and duration was a slightly better fit, based on a likelihood ratio test. However, from a practical standpoint, it appears that for the tested parameters, duty cycle alone is a sufficient measure of exertion. This study also found that combinations combining high force and high duty cycle were the most difficult for subjects. Combinations of lower force and modest duty cycles (containing modest frequencies) were the easiest for subjects to sustain. Future studies should look at a broader range of durations and higher forces to further define acceptable (i.e., sustainable, safe) repetitive dynamic grip combinations

Searching from the heart: The interplay between emotions and customization in online health information seeking

The prospect of a threat to one's health or an opportunity for improved health can spark emotional reactions--the fear of an illness or the hope of a healthier life. People are increasingly turning to the Internet to search for information related to such health issues. However, the dizzying amount of online health information--some of it of dubious quality--makes the task of finding trustworthy and relevant health information difficult. One way to address this dilemma is to utilize technology's ability to provide users with customized content based on their unique desires and preferences. Grounded in the literatures on emotions, health information seeking, and customization, one approach to improving the efficiency and effectiveness of the health information seeking process would be to craft customized search engine results based on the user's situational emotion state. Further customizing of health search results based on dispositional aspects of the user's identity--in addition to the situational emotion--is a conceptually promising approach to improving the health information seeking process. This dissertation examined the relationship between types of emotional experiences and health information seeking as well as the interplay of emotion states and customization in the health information seeking process. The results revealed that discrete emotions have an important impact on multiple steps in the health information seeking process, from search query generation to post-search cognitions, attitudes, and behaviors. Additionally, the results indicate that customizing health-related search results based on situational factors may not be as effective as customizing search results based on dispositional aspects of a user's identity. Theoretical, methodological, and public health implications are discussed and directions for future research in this domain are offered.Doctor of Philosoph

Genetics and nutrition impacts on herd productivity in the Northern Australian beef cattle production cycle

Genetics and nutrition drive herd productivity due to significant impacts on all components of the beef cattle production cycle. In northern Australia, the beef production system is largely extensive and relies heavily on tropical cattle grazing low quality, phosphorus-deficient pastures with seasonal variations in nutritive value. The existing feedlots are predominantly grain-based; providing high-energy rations, faster turn-off and finishing of backgrounded cattle to meet market specifications. This review focusses on the beef cattle production cycle components of maternal nutrition, foetal development, bull fertility, post-natal to weaning, backgrounding, feedlotting, rumen microbes and carcass quality as influenced by genetics and nutrition. This student-driven review identified the following knowledge gaps in the published literature on northern Australian beef cattle production cycle: 1. Long-term benefits and effects of maternal supplementation to alter foetal enzymes on the performance and productivity of beef cattle; 2. Exogenous fibrolytic enzymes to increase nutrient availability from the cell wall and better utilisation of fibrous and phosphorus deficient pasture feedbase during backgrounding; 3. Supplementation with novel encapsulated calcium butyrate and probiotics to stimulate the early devel- opment of rumen papillae and enhance early weaning of calves; 4. The use of single nucleotide polymorphisms as genetic markers for the early selection of tropical beef cattle for carcass and meat eating quality traits prior to feedlotting; The review concludes by recommending future research in whole genome sequencing to target specific genes associated with meat quality characteristics in order to explore the development of breeds with superior genes more suited to the North Australian beef industry. Further research into diverse nutritional strategies of phosphorus supplementation and fortifying tropically adapted grasses with protein-rich legumes and forages for backgrounding and supplementing lot-fed beef cattle with omega-3 oil of plant origin will ensure sustainable production of beef with a healthy composition, tenderness, taste and eating quality

Development and Validation of the Comprehensive Indoor Tanning Expectations Scale

IMPORTANCE: Strong links between indoor tanning behavior and skin cancer have been demonstrated across several studies. Understanding the complex belief systems that underlie indoor tanning in young women is a crucial first step in developing interventions to deter this behavior. OBJECTIVES: To develop and validate a comprehensive, multidimensional, theory-based outcome expectations measure to advance an understanding of the sets of beliefs that underlie indoor tanning behavior among young women. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study comprising a web-based survey of 11 sororities at a large university in the southeastern United States. Study participants (n = 706) were aged 18 to 25 years; 45.3% had tanned indoors in their lifetime and 30.3% in the past year. MAIN OUTCOMES AND MEASURES: Intention to tan indoors, frequency of indoor tanning behavior in the past year, and indoor tanner type (nontanner, former tanner, or current tanner). RESULTS: A comprehensive scale assessing indoor tanning outcome expectations was developed. In total, 6 positive outcome expectations factors and 5 negative outcome expectations factors were identified. These subscales were reliable (coefficient α range, 0.86-0.95) and were significantly (mostly at P < .001) correlated with a set of established measures, including appearance motivation, indoor tanning attitudes and norms, and intention to tan indoors. Examination of subscales across the 3 indoor tanning groups also revealed significant (P < .001) differences on all 11 subscales. Current tanners had the most positive and least negative perceptions about indoor tanning, while nontanners had the most negative and least positive perceptions. Former tanners tended to fall in between these 2 groups. The 2 subscales with the largest differences across the groups were mood enhancement (positive outcome expectation) and psychological/physical discomfort (negative outcome expectation). Multiple linear regression analyses demonstrated several outcome expectations subscales to be significantly associated with intention to tan indoors and frequency of indoor tanning behavior. CONCLUSIONS AND RELEVANCE: Results suggest that the Comprehensive Indoor Tanning Expectations (CITE) Scale provides a reliable and valid assessment of the complex sets of beliefs that underlie indoor tanning, including positive (motivational) and negative (deterrent) beliefs. This new scale may further advance research on indoor tanning beliefs and can guide health communications to prevent and deter indoor tanning behavior

Prevalence of pulmonary hypertension in the general population : the Rotterdam study

Background: Pulmonary hypertension is characterized by increased pulmonary artery pressure and carries an increased mortality. Population-based studies into pulmonary hypertension are scarce and little is known about its prevalence in the general population. We aimed to describe the distribution of echocardiographically-assessed pulmonary artery systolic pressure (ePASP) in the general population, to estimate the prevalence of pulmonary hypertension, and to identify associated factors. Methods: Participants (n = 3381, mean age 76.4 years, 59% women) from the Rotterdam Study, a population-based cohort, underwent echocardiography. Echocardiographic pulmonary hypertension was defined as ePASP>40 mmHg. Results: Mean ePASP was 26.3 mmHg (SD 7.0). Prevalence of echocardiographic pulmonary hypertension was 2.6% (95%CI: 2.0; 3.2). Prevalence was higher in older participants compared to younger ones (8.3% in those over 85 years versus 0.8% in those between 65 and 70), and in those with underlying disorders versus those without (5.9% in subjects with COPD versus 2.3%; 9.2% in those with left ventricular systolic dysfunction versus 2.3%; 23.1% in stages 3 or 4 left ventricular diastolic dysfunction versus 1.9% in normal or stage 1). Factors independently associated with higher ePASP were older age, higher BMI, left ventricular diastolic dysfunction, COPD and systemic hypertension. Conclusion: In this large population-based study, we show that pulmonary hypertension as measured by echocardiography has a low prevalence in the overall general population in the Netherlands, but estimates may be higher in specific subgroups, especially in those with underlying diseases. Increased pulmonary arterial pressure is likely to gain importance in the near future due to population aging and the accompanying prevalences of underlying disorders

Prevalence of pulmonary hypertension in the general population

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A Novel Agonist of the TRIF Pathway Induces a Cellular State Refractory to Replication of Zika, Chikungunya, and Dengue Viruses.

The ongoing concurrent outbreaks of Zika, Chikungunya, and dengue viruses in Latin America and the Caribbean highlight the need for development of broad-spectrum antiviral treatments. The type I interferon (IFN) system has evolved in vertebrates to generate tissue responses that actively block replication of multiple known and potentially zoonotic viruses. As such, its control and activation through pharmacological agents may represent a novel therapeutic strategy for simultaneously impairing growth of multiple virus types and rendering host populations resistant to virus spread. In light of this strategy\u27s potential, we undertook a screen to identify novel interferon-activating small molecules. Here, we describe 1-(2-fluorophenyl)-2-(5-isopropyl-1,3,4-thiadiazol-2-yl)-1,2-dihydrochromeno[2,3

Orbit size and estimated eye size in dinosaurs and other archosaurs and their implications for the evolution of visual capabilities

Vision is one of the most important senses for animals, allowing them to interact with their environment and with further implications for evolutionary histories. However, relevant soft tissues, such as the eye and associated structures, are not preserved in fossil vertebrates, limiting our knowledge of their visual capabilities. Here, we quantified absolute and relative orbit size for 400 species of dinosaurs and other extinct archosaurs using linear measurements of the preserved skeletal elements as a proxy for visual capabilities. Our results demonstrate that the orbit makes up on average 20% of skull size with a strong and consistent correlation across all sampled groups. This trend is largely independent of temporal distribution, species richness, and phylogeny. In fact, relative orbit size is narrowly constrained and did not surpass 45% of skull size, suggesting physiological and functional controls. Estimated eye size was found to be absolutely larger in herbivores, whereas carnivores tended to have smaller eyes absolutely and compared with skull size. Relatively large eyes only occurred in small-bodied species and vice versa. However, eye size alone was not sufficient to discriminate between different activity patterns or to characterize visual capabilities in detail.</p

Childhood/Adolescent Smoking and Adult Smoking and Cessation: The International Childhood Cardiovascular Cohort (i3C) Consortium

BACKGROUND: Despite declining US adolescent smoking prevalence from 40% among 12th graders in 1995 to around 10% in 2018, adolescent smoking is still a significant problem. Using the International Childhood Cardiovascular Cohort (i3C) Consortium, which includes 7 international cohorts recruited in childhood and followed into adulthood, the present study was designed to confirm the important relation between adolescent smoking and daily adult smoking and present new data on adult smoking into the forties and comparison of smoking in the United States, Finland, and Australia. METHODS AND RESULTS: Childhood smoking experience during ages 6 to 19 in the 1970s and 1980s was classifiable in 6687 i3C participants who also provided smoking status in their twenties and forties through 2011-2018. Prevalence of daily smoking in their twenties was directly related to degree of smoking during adolescence and inversely related to the age at which that smoking experience occurred (P trend, < 0.001). Similar patterns were observed for prediction of smoking during age forties. Among the 2465 smokers in their twenties, cessation by their forties was generally inverse to degree of smoking in ages 6 to 19 (P trend, <0.001). Prevalence of smoking during adolescence and adulthood was similar among US, Finnish, and Australian participants. CONCLUSIONS: These long--term follow--up data show that smoking intensity increased throughout adolescence. Prevalence of adult smoking and cessation by the forties were both correlated with levels of childhood smoking intensity. These data lend support to preventive strategies designed to reduce, delay, or eliminate any youth access to cigarettes