Hartfiel N, Havenhand J, Khalsa SB, Clarke G, Krayer A. The effectiveness of yoga for the improvement of well-being and resilience to stress in the workplace. Scand J Work Environ Health. 2011;37(1):70-76.Objectives Recent research has indicated concern for the degree of stress and emotional well-being among university staff. This study examined the effectiveness of yoga in enhancing emotional well-being and resilience to stress among university employees.Methods In a randomized controlled trial at a British university, we recruited 48 employees and randomized them into either a yoga or a wait-list control group. The yoga group was offered six weeks of Dru Yoga, comprising one 60-minute class per week. These classes were offered by a certified Dru Yoga instructor at lunchtime from January-March 2008. The wait-list control group received no intervention during this six-week study. Baseline and end-program measurements of self-reported mood and well-being were self-assessed with the Profile of Mood States -Bipolar (POMS-Bi) and the Inventory of Positive Psychological Attitudes (IPPA).Results This six-week yoga intervention resulted in significantly improved POMS-Bi and IPPA scores for the yoga compared to the wait-list control group for seven of eight measures of mood and well-being. In comparison to the wait-list control group at baseline and the end of the program, the yoga group reported marked improvements in feelings of clear-mindedness, composure, elation, energy, and confidence. In addition, the yoga group reported increased life purpose and satisfaction, and feelings of greater self-confidence during stressful situations. ConclusionThese results show that even a short program of yoga is effective for enhancing emotional wellbeing and resilience to stress in the workplace. We suggest that employers should consider offering yoga classes to their employees.Key terms breathing exercise; movement; occupational health; physical activity; positive health; randomized controlled trial; RCT; relaxation. Improving well-being and resilience to stress are key issues facing many organizations (1-2). In the UK alone, 97% of senior human resources professionals believe stress is the biggest threat to the future health of the workforce (3), and estimates suggest 175 million working days are lost each year in the UK due to sickness absence, half of which are stress-related (4). There is also a growing trend toward long-term absences of ≥20 days, due in large part to psychosocial factors such as stress, anxiety, and depression (5).Well-being in the workplace is characterized by employees who perceive themselves to be growing, engaged, and productive and who experience positive emotional states such as pleasure, joy, and energy that help buffer against stress and depression (6-8). Stress has been defined as the inability to cope with a perceived threat to one's mental, physical, emotional, and spiritual well-being (9). Resilience to stress means that employees can respond productively when faced with significant change or pre...

The results indicate that a workplace yoga intervention can reduce perceived stress and back pain and improve psychological well-being. Larger randomized controlled trials are needed to determine the broader efficacy of yoga for improving workplace productivity and reducing sickness absence.

In species where females store sperm from their mates prior to fertilization, sperm competition is particularly probable. Female Sepia apama are polyandrous and have access to sperm from packages (spermatangia) deposited by males onto their buccal area during mating and to sperm stored in internal sperm-storage organs (receptacles) located below the beak. Here, we describe the structure of the sperm stores in the female's buccal area, use microsatellite DNA analyses to determine the genetic diversity of stored sperm and combine these data with offspring genotypes to determine the storage location of paternal sperm. The number of male genotypes represented in the sperm receptacles was significantly lower than that found among the spermatangia. Estimation of the volumes of sperm contained in the receptacles and the spermatangia were statistically comparable; however, paternal sperm were more likely to have come from spermatangia than from the sperm receptacles. These results confirm a genetic polyandrous mating system in this species and suggest that fertilization pattern with respect to the sperm stores used is not random.

Many hypotheses have been put forward to explain the evolution of different larval types in marine invertebrates. These hypotheses have generally ignored the impact which the larval (developmental) type can have on the adult stage of the life cycle. A conceptual model presented here shows how reduction of the pre-metamorphic, or 'egg-to-juvenile' period either increases size at reproduction [by increasing the benthic (post-metamorphic) development period in the case of species with fixed duration Me cycles], or decreases overall generation times (in species with fixed size or age at reproduction, and variable life cycle duration). In either case the net result is an increase in fitness. A simple analytical version of this model is derived and is illustrated with data from 2 species of nudibranch mollusc. The model reveals an 'optimal' egg-to-juvenile period [where the intrinsic rate of increase ( K ) is maximised] for all life-cycle durations modelled. Reduction of the egg-to-juvenile period leads to an increase in r in all cases except when egg-to-juvenile period is very short. At egg-tojuvenile periods typical of species with feeding larvae, increases in r may be considerable (a reduction in egg-to-juvenile period from 100 d to 90 d yields a 4 to 13 % increase in I ) . Available evidence from several taxa indicates that developmental type and egg-to-juvenile period are correlated, such that species with non-feeding larvae tend to have shorter egg-to-juvenile periods. Consequently, the selective pressures to reduce egg-to-juvede period which are Illustrated by this model highlight a previously overlooked pressure for the evolution of non-feeding larvae in marine invertebrates.

‘Multiple drivers’ (also termed ‘multiple stressors’) is the term used to describe the cumulative effects of multiple environmental factors on organisms or ecosystems. Here, we consider ocean acidification as a multiple driver because many inorganic carbon parameters are changing simultaneously, including total dissolved inorganic carbon, CO2, HCO3–, CO32–, H+ and CaCO3 saturation state. With the rapid expansion of ocean acidification research has come a greater understanding of the complexity and intricacies of how these simultaneous changes to the seawater carbonate system are affecting marine life. We start by clarifying key terms used by chemists and biologists to describe the changing seawater inorganic carbon system. Then, using key groups of non-calcifying (fish, seaweeds, diatoms) and calcifying (coralline algae, coccolithophores, corals, molluscs) organisms, we consider how various physiological processes are affected by different components of the carbonate system.