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Plant-soil feedback (PSF) describes the process whereby plant species modify the soil environment, which subsequently impacts the growth of the same or another plant species. Our aim was to explore PSF by two maize varieties (a landrace and a hybrid variety) and three arbuscular mycorrhizal fungi (AMF) species (Funneliformis mosseae, Claroideoglomus etunicatum, Gigaspora margarita, and the mixture). We carried out a pot experiment with a conditioning and a feedback phase to determine PSF with different species of AMF and with a non-mycorrhizal control. Sterilized soil was conditioned separately by each variety, with or without AMF; in the feedback phase, each soil community was used to grow each in its "home" soil and in the "away" soil. Plant performance was assessed as shoot biomass, phosphorus (P) concentration and P content, and fungal performance was assessed as mycorrhizal colonization and hyphal length density. Both maize varieties were differentially influenced by AMF in the conditioning phase. In the feedback phase, PSF was generally negative for non-mycorrhizal plants or when plants were colonized by G. margarita, whereas PSF was positive in the other three AMF treatments. When plants were grown on home soil, hyphal length density was larger than on away soil. We conclude that different maize varieties can strengthen positive plant-soil feedback for themselves through beneficial mutualists for themselves, but not across the maize varieties.

Objective: BeweegKuur (Exercise Therapy) is a Dutch lifestyle programme in which participants are referred by a general practitioner (GP) to a lifestyle advisor. To support participants, regional and local alliances are established. The present study explored the successes and challenges associated with collaboration processes in local BeweegKuur alliances. Design: A qualitative explorative study. Setting: The Netherlands Institute for Sports and Physical Activity (NISB) initiated the Building BeweegKuur Alliances project to support local alliances. The BeweegKuur intervention is implemented by over 30 regional and about 150 local alliances throughout the Netherlands. Method: 12 in-depth interviews were held with coordinators of the alliances, and four focus groups were held with regional and local alliance partners. Results: Collaboration within the alliances is perceived as successful in integrating prevention and care. Challenges include the participation of sectors such as the local municipality and the sports sector, and the transition of BeweegKuur participants to local sports facilities. Conclusion: This study identifies three general conditions for successful coordinated action: (a) flexible protocols and management that allow for contextual adaptations; (b) making successes and challenges visible using facilitating methods and tools; and (c) time and funding to overcome differences of culture between different sectors, and to build trust.

AbstractAlthough canopy height has long been a focus of interest in ecology, it has remained difficult to study at large spatial scales. Recently, satellite‐borne LiDAR equipment produced the first systematic high resolution maps of vegetation height worldwide. Here we show that this new resource reveals three marked modes in tropical canopy height ~40, ~12, and ~2 m corresponding to forest, savanna, and treeless landscapes. The distribution of these modes is consistent with the often hypothesized forest‐savanna bistability and suggests that both states can be stable in areas with a mean annual precipitation between ~1,500 and ~2,000 mm. Although the canopy height states correspond largely to the much discussed tree cover states, there are differences, too. For instance, there are places with savanna‐like sparse tree cover that have a forest‐like high canopy, suggesting that rather than true savanna, those are thinned relicts of forest. This illustrates how complementary sets of remotely sensed indicators may provide increasingly sophisticated ways to study ecological phenomena at a global scale.

Small but numerically dominant species such as the cyanobacteria Prochlorococcus play a pivotal role in major nutrient cycles. To understand how Prochlorococcus populations affect nutrient flows, we present and analyze two alternative population models. These models − one including over-shading effects and one not − are based on Dynamic Energy Budget (DEB) theory to describe how growth may be affected by the availability of CO2 and/or inorganic nutrients and by changes in light conditions. In these models individuals have reserves for C, N, and P from which fluxes for maintenance and growth are mobilized. Time series data from laboratory studies of growth under three different nutrient concentrations are used to calibrate the models. The model with carbon, nitrogen and phosphate as limiting factors can reasonably describe the growth in the low N and low P media experiments, while the model with over-shading gives a proper description of the growth under all tested experimental conditions. Modeled C:N:P ratios are within range of reported in scientific literature ones and similar to measured ratios. The results suggest that (1) reserves play a critical role for cyanobacteria to thrive under the often oligotrophic conditions in which they live, and (2) over-shading has a considerable effect as co-limiting factor on the growth of cyanobacteria. We argue that an individual DEB-based model in which multiple nutrient limitations are presented can be used to successfully describe cyanobacterium growth patterns in batch cultures.

Policymakers at global level recognise that household biomass use in developing countries has significant health consequences. However, it is unclear how local-level health professionals perceive and respond to such health effects. This paper which is derived from the findings of a larger study on perceptions and responses to the harmful health effects of carrying heavy firewood loads and to smoke from cooking fires is based on a study conducted in South Africa among managers of health programmes and community nurses of Qaukeni and Mhlontlo municipalities in rural Eastern Cape. Interviews and participant observations were conducted in 2009 using ethnographic grounded theory approaches. In addition to a 10-month period of ethnographic fieldwork, ten programme managers and nurses in two villages were interviewed about health patterns in the villages that they serve, their perceptions of, and responses to the health effects of carrying heavy firewood loads, and inhalation of smoke from wood and dung cooking fires, their professional qualifications and experience, their own household energy use; and observations made as they served clinic clients. Results show that these programme managers and nurses perceive the health effects of carrying heavy loads of firewood and of cooking smoke as minor. Sometimes, nurses give women symptomatic relief for musculoskeletal pain resulting from carrying heavy loads. We posit that their perceptions are derived from customary neglect of work-related health and non-communicable diseases, cultural interpretations of womanhood, limited access to relevant information, and limited interactions between health and energy sector professionals. We conclude that culturally and gender-sensitive awareness programmes are needed for local-level health professionals to effectively address health effects of biomass collection and use. This paper provides new insights into overlooked differences between globally-driven initiatives to address health effects of biomass use and local perceptions.

AbstractBackground: Chlorhexidine (CHX) 0.2% solution is still “the leading oral antiseptic” for controlling gingivitis. Side effects, however, limit the acceptability to users and the long‐term employment of a 0.2% CHX antiseptic in preventive dentistry. This stimulated the development of new formulations. The aim of the present study was to assess the effect on plaque inhibition and taste perception of two commercially available mouthrinses (0.12% CHX non‐alcohol base with 0.05% cetyl pyridinium chloride (Cpc) versus 0.2% CHX alcohol base).Methods: The study was designed as a single‐blind, randomized two group parallel experiment, to compare two different commercially available mouthrinses, during a 3‐day plaque accumulation model. Forty healthy volunteers were enrolled in the study and received a thorough dental prophylaxis at the beginning of the test period. Over a 72‐h experimental non‐brushing period, during which subjects abstained from all forms of mechanical oral hygiene, one group (test) used a 15 ml alcohol free 0.12% CHX (=18 mg) mouthrinse on a Cpc base (Perioaid®, CHX⊕Cpc), twice daily for 30 s. The other group (control) used a 10 ml 0.2% CHX (=20 mg) mouthrinse on an 11.8% ethanol alcohol base (Corsodyl®, CHX⊕Alc), twice daily for 60 s. After 72 h of plaque formation, the amount of plaque was evaluated. By the use of visual analogue scale, the subjects were asked for their appreciation of the taste of the mouthrinse they had used.Results: The mean plaque index for the CHX⊕Cpc group was 0.97 and for the CHX⊕Alc group 0.78. After 72 h of non‐brushing, there was no significant difference in plaque accumulation between the two groups. The answers to the questions (taste perception and after‐taste) showed a statistically significant difference between the two groups. The mean visual analogue scale (VAS) scores for taste appreciation on a scale from very bad to very good taste (0–10) were 5.92 for the CHX⊕Cpc group and 4.10 for the CHX⊕Alc group (p=0.02). The mean visual analogue scale (VAS) scores for the after‐taste on a scale from very short to very long (0–10) were 7.24 for the CHX⊕Cpc group and 5.38 for the CHX⊕Alc group.Conclusions: Within the limitations of the present study design, it can be concluded that rinsing with a 0.12% CHX mouthrinse on a non‐alcohol base with 0.05% Cpc (Perio‐Aid®) is not significantly different from rinsing with a 0.2% CHX mouthrinse on an alcohol base (Corsodyl®). It appears that the subjects appreciated the taste of the non‐alcohol CHX solution better but the after‐taste of the rinse remained longer in the mouth.

In medial tibial stress syndrome (MTSS) bone marrow and periosteal edema of the tibia on the magnetic resonance imaging (MRI) is frequently reported. The relationship between these MRI findings and recovery has not been previously studied. This prospective study describes MRI findings of 52 athletes with MTSS. Baseline characteristics were recorded and recovery was related to these parameters and MRI findings to examine for prognostic factors. Results showed that 43.5% of the symptomatic legs showed bone marrow or periosteal edema. Absence of periosteal and bone marrow edema on MRI was associated with longer recovery (P = 0.033 and P = 0.013). A clinical scoring system for sports activity (SARS score) was significantly higher in the presence of bone marrow edema (P = 0.027). When clinical scoring systems (SARS score and the Lower Extremity Functional Scale) were combined in a model, time to recovery could be predicted substantially (explaining 54% of variance, P = 0.006). In conclusion, in athletes with MTSS, bone marrow or periosteal edema is seen on MRI in 43,5% of the symptomatic legs. Furthermore, periosteal and bone marrow edema on MRI and clinical scoring systems are prognostic factors. Future studies should focus on MRI findings in symptomatic MTSS and compare these with a matched control group.