The gas vesicles, buoyancy and vertical distribution of cyanobacteria in the Baltic Sea

The mean pressures required to collapse gas vesicles in turgid cells of cyanobacteria from the Baltic Sea were 0·91 MPa (9·1 bar) in Aphanizomenon flos-aquae, 0·83 MPa in Nodularia sp. collected from the main deep basins and 0·34 MPa in Nodularia from shallower coastal regions. The gas vesicles were strong enough to withstand the depth of winter mixing, down to the permanent halocline (60 m in the Bornholm Sea, 90 m in the Eastern Gotland Sea) or to the sea bottom (30 m or less in the shallow Arkona Sea and Mecklenburg Bight). The cyanobacteria had low cell turgor pressures, within the range 0·08–0·18 MPa. The colonies were highly buoyant: the Aphanizomenon colonies floated up at a mean velocity of 22 m per day and the Nodularia colonies at 36 m per day. The colonies remained floating when up to half of the gas vesicles had been collapsed. In summer the cyanobacteria were mostly restricted to the water above the thermocline and in calm conditions their concentration increased towards the top of the water column. A series of colony concentration profiles indicated that, following a deep mixing event, the population of colonies moved upward with a net velocity of 22 m per day, similar to the colony floating velocity. This demonstrated that the buoyancy provided by gas vesicles would give a selective advantage to populations of cyanobacteria by enabling them to float into the higher irradiance of the near-surface water

Contextual Positive Psychology: Policy Recommendations for Implementing Positive Psychology into Schools

There has been a rapid growth in positive psychology, a research and intervention approach that focuses on promoting optimal functioning and well-being. Positive psychology interventions are now making their way into classrooms all over the world. However, positive psychology has been criticized for being decontextualized and coercive, and for putting an excessive emphasis on positive states, whilst failing to adequately consider negative experiences. Given this, how should policy be used to regulate and evaluate these interventions? We review evidence that suggests these criticisms may be valid, but only for those interventions that focus almost exclusively on changing the content of people’s inner experience (e.g., make it more positive) and personality (improving character strength), and overemphasize the idea that inner experience causes action. We describe a contextualized form of positive psychology that not only deals with the criticisms, but also has clear policy implications for how to best implement and evaluate positive education programs so that they do not do more harm than good

Supporting strong families and capable communities through cross-national research

Background Mental and behavioral ill-health are growing global problems and while there are promising evidence-based approaches aimed at reducing their impact, availability of services varies greatly, not only across nations, but also between urban, regional, and remote locations. Rural areas face accessibility and acceptability challenges related to mental health services that are similar to barriers experienced in developing countries. Initiatives to address mental health challenges in under-served rural areas can inform global mental health strategies. Methods Using a public health approach, we illustrate how innovations in rural communities build community capacity and capability in areas that are currently, and are likely to remain, under-served by specialist mental health services. We provide examples of initiatives and key principles of action from three locations in Nebraska, United States of American and New South Wales, Australia to highlight similarities of context and practice. Results While each of the initiatives was developed independently, there are striking similarities across them. Similarities in initiatives include: a) recognition that solutions developed in urban settings are not necessarily the most effective in under- served rural areas, b) engagement of community members is needed to ensure acceptance of initiatives in target communities, c) each initiative involved community members acting on their own behalf with an emphasis on prevention and early intervention, and d) research is a key aspect that informs practice and has local relevance. Commonalities of contexts and environments may have played an important role in the similarities. Conclusions Linking initiatives within and between countries can expand local, national, and global reach and impacts. If we are to meet lofty global goals related to health and wellbeing, cross-national collaborations are needed to share resources, expand expertise, and stimulate ideas necessary to develop and enhance local and global initiatives. High-income country partnerships addressing mental health in under-served areas, such as rural communities, can play a vital role in contributing to global mental health solutions