Using data from a 30-day diary study with 239 adults (81 young, 81 middle-aged, and 77 older adults) this study examined whether a specific ratio between positive and negative affect distinguished individuals with different mental health status and especially flourishing from nonflourishing individuals. In addition, the study addressed whether there were age differences in the positivity ratio when daily affect data were used, and whether the proposed critical positivity ratio of 2.9 discriminated equally well between individuals with different mental health status across the adult lifespan. Findings showed that the ratio of positive to negative affect differed across adulthood such that age was associated with an increasing preponderance of positive to negative affect. The positivity ratio was also associated with mental health status in the hypothesized direction; higher positivity ratios were associated with better mental health. Finally, although the data supported the notion of a positivity ratio of 2.9 as a "critical value" in young adulthood, this value did not equally well discriminate the mental health status of middle-aged and older adults. Keywordsadulthood; positive and negative affect; positivity ratio; mental health Researchers have long suggested that the balance of positive to negative affect is critically relevant to well-being and adjustment (Bradburn, 1969;Kahneman, 1999). Recently, Larsen and Prizmic (2008) argued that the balance of positive to negative affect (hereafter referred to as the positivity ratio) is a key factor in subjective well-being and in defining whether a person flourishes. Larsen and Prizmic discussed work by several authors (e.g., Fredrickson & Losada, 2005;Gottman, 1994;Schwartz, 1997;Schwartz et al., 2002) which suggests that to maintain an optimal level of emotional well-being and positive mental health, individuals need to experience approximately three times more positive than negative affect. Given this background, the present study addressed three questions. First, is there evidence that a specific positivity ratio distinguishes individuals with different mental health status and especially flourishing from non-flourishing individuals? Second, are there age differences in the positivity ratio when daily affect data are used? Third, does the proposed critical positivity ratio of 2.9 discriminate individuals with different mental health status equally well across the adult lifespan? The Critical Ratio of Positive to Negative AffectThe argument that the ratio of positive to negative affect distinguishes well-functioning individuals from others has been well articulated by Fredrickson and Losada (2005). Drawing on a variety of research, Fredrickson and Losada demonstrated that a positivity ratio of about 3:1 could distinguish between high-and low-performing work teams. Testing the generalizability of their model, these authors also examined the positivity ratios and mental health status of college students, using Keyes' (2002, 20005) definition of flourishin...

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Objectives: Recent studies have shown that brief periods of mechanical ventilation (MV) in animals and humans can lead to ventilator induced diaphragmatic dysfunction (VIDD), which includes muscle atrophy, reduced force development and impaired mitochondrial function. Animal work has shown that short periods of increased diaphragm activity during MV support can attenuate VIDD, but corresponding human data are lacking. The purpose of this study was to examine the effect of intermittent diaphragm contractions during cardiothoracic surgery, including controlled MV, on mitochondrial respiration in the human diaphragm. Method: In five patients (age 65.6 ± 6.3 yrs) undergoing cardiothoracic surgery, one phrenic nerve was stimulated hourly (30 pulses per minute, 1.5 msec duration, 17.0 ± 4.4 mA) during the surgery. Subjects received 3.4 ± 0.6 stimulation bouts during surgery. Thirty minutes following the last stimulation bout, samples of diaphragm muscle were obtained from the antero-lateral costal regions of the stimulated and inactive hemidiaphragms. Mitochondrial respiration was measured in permeabilized muscle fibers with high-resolution respirometry. Results: State III mitochondrial respiration rates (pmol O2/sec/mg wet weight) were 15.05 ± 3.92 and 11.42 ± 2.66 for the stimulated and unstimulated samples respectively, p < 0.05. State IV mitochondrial respiration rates were 3.59 ± 1.25 and 2.11 ± 0.97 in the stimulated samples and controls samples, respectively, p < 0.05. Conclusion: These are the first data examining the effect of intermittent contractions on mitochondrial respiration rates in the human diaphragm following surgery/MV. Our results indicate that very brief periods (duty cycle ~1.7%) of activity can improve mitochondrial function in the human diaphragm following surgery/MV.

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The present study assessed use of food as a coping mechanism and cognitive distortions regarding food and weight in relation to extent of bulimic symptomatology. Subjects were 19 women who fulfilled an operationalized defination of the DSM‐III diagnostic criteria for bulimia (bulimics), 35 women who fulfilled an operationalized definition of an absence of bulimic symptomology (symptom‐free), and 41 women who fulfilled some but not all bulimic criteria (bulimic‐like). The symptom‐free, bulimic‐like, and bulimic groups each differed from one another in a linear fashion from low to high on measures of use of food as a coping mechanism, five of eight types of cognitive distortions regarding food and weight (dichotomous thinking, worry, exaggeration, superstitious thinking, and personalization), drive for thinness, and lack of interoceptive awareness. The bulimic and bulimic‐like groups evidenced greater perfectionism, defeatism, regret, and body dissatisfaction than the symptom‐free group. Variation in the extent of use of food and cognitive distortions accounted for 70% of explained variance in the severity of DSM‐III bulimic symptomatology. These results suggest that behavioral, affective, and cognitive indices of bulimia fall along parallel continua of symptomatic severity. The results also support the relevance of preventative and therapeutic programs with multidimensional foci.