Aluminum-Tolerant Pisolithus Ectomycorrhizas Confer Increased Growth, Mineral Nutrition, and Metal Tolerance to Eucalyptus in Acidic Mine Spoil

Ectomycorrhizal fungi (ECM) may increase the tolerance of their host plants to Al toxicity by immobilizing Al in fungal tissues and/or improving plant mineral nutrition. Although these benefits have been demonstrated in in vitro (pure culture) or shortterm nutrient solution (hydroponic) experiments, fewer studies have examined these benefits in the field. This study examined the growth, mineral nutrition, and Al levels in two Eucalyptus species inoculated with three Pisolithus ecotypes that varied in Al tolerance (in vitro) and grown in mine spoil in the greenhouse and field. All three ecotypes of Pisolithus improved Eucalyptus growth and increased host plant tolerance to Al in comparison to noninoculated plants. However, large variations in plant growth and mineral nutrition were detected among the Pisolithus-inoculated plants; these differences were largely explained by the functional properties of the Pisolithus inoculum. Seedlings inoculated with the most Al-tolerant Pisolithus inoculum showed significantly higher levels of N, P, Ca, Mg, and K and lower levels of Al than seedlings inoculated with Al-sensitive ecotypes of Pisolithus. These findings indicate an agreement between the fungal tolerance to Al in vitro and performance in symbiosis, indicating that both ECM-mediated mineral nutrient acquisition and Al accumulation are important in increasing the host plant Al tolerance

Interactions of arbuscular mycorrhizal fungi, critical loads of nitrogen deposition, and shifts from native to invasive species in a southern California shrubland

Anthropogenic nitrogen (N) deposition and invasive species are causing declines in global biodiversity, and both factors impact the diversity and functioning of arbuscular mycorrhizal (AM) fungi. Shifts in arbuscular mycorrhizal fungal (AMF) communities can generate feedback to native plants and affect their success, as was observed in California’s coastal sage scrub, which is a Mediterranean-type shrubland threatened by invasive grasses. As vegetation-type conversion from native shrubland to exotic annual grassland increased along a gradient of increasing N deposition, the richness of native plant species and of spore morphotypes decreased. Rapid declines in all plant and fungal values occurred at the critical load (CL) of 10–11 kg N·ha−1·year−1, indicating that AM fungi respond to the same environmental signals as the plants, and can be used to assess CL. Shrub root colonization also decreased along the N gradient, but colonization of the invasive grass was dominated by a fine AMF endophyte that was unresponsive to elevated N. A greenhouse experiment to assess AMF functioning showed that the native shrub Artemisia californica Less. had a negative growth response to an inoculum from high-N but not low-N soils, whereas the invasive grass Bromus rubens L. had a positive response to both inocula. Differential functioning of AM fungi under N deposition may in part explain vegetation-type conversion and the decline of this native shrubland

Arbuscular mycorrhizal fungi as mediators of ecosystem responses to nitrogen deposition: A trait-based predictive framework

Anthropogenic nitrogen (N) deposition is exposing plants and their arbuscular mycorrhizal fungi (AMFs) to elevated N availability, often leading to shifts in communities of AMF. However, physiological trade-offs among AMF taxa in their response to N enrichment vs the ability to acquire other soil nutrients could have negative effects on plant and ecosystem productivity. It follows that information on the functional traits of AMF taxa can be used to generate predictions of their potential role in mediating ecosystem responses to N enrichment. Arbuscular mycorrhizal fungi taxa that produce extensive networks of external hyphae should forage for N and phosphorus (P) more effectively, but these services incur greater carbon (C) costs to the plant. If N enrichment ameliorates plant nutrient limitation, then plants may reduce C available for AMF, which in turn could eliminate AMF taxa with large extensive external hyphae from the soil community. As a result, the remaining AMF taxa may confer less P benefit to their host plants. Using a synthesis of data from the literature, we found that the ability of a taxon to persist in the face of increasing soil N availability was particularly high in isolates from the genus Glomus, but especially low among the Gigasporaceae. Across AMF genera, our data support the prediction that AMF with a tolerance for high soil N may confer a lower P benefit to their host plant. Relationships between high N tolerance and production of external hyphae were mixed. Synthesis. If the relationship between N tolerance and plant P benefit is widespread, then shifts in arbuscular mycorrhizal fungi communities associated with N deposition could have negative consequences for the ability of plants to acquire P and possibly other nutrients via a mycorrhizal pathway. Based on this relationship, we predict that arbuscular mycorrhizal fungi responses could constrain net primary productivity in P-limited ecosystems exposed to N enrichment. This prediction could be tested in future empirical and modelling studies

Deliberate clinical inertia: Using meta-cognition to improve decision-making

Deliberate clinical inertia is the art of doing nothing as a positive response. To be able to apply this concept, individual clinicians need to specifically focus on their clinical decision-making. The skill of solving problems and making optimal clinical decisions requires more attention in medical training and should play a more prominent part of the medical curriculum. This paper provides suggestions on how this may be achieved. Strategies to mitigate common biases are outlined, with an emphasis on reversing a 'more is better' culture towards more temperate, critical thinking. To incorporate such an approach in medical curricula and in clinical practice, institutional endorsement and support is required

Perceptions of Australasian emergency department staff of the impact of alcohol-related presentations

Objectives: To survey emergency department (ED) clinical staff about their perceptions of alcohol-related presentations. Design, setting and participants: A mixed methods online survey of ED clinicians in Australia and New Zealand, conducted from 30 May to 7 July 2014. Main outcome measures: The frequency of aggression from alcoholaffected patients or their carers experienced by ED staff; the perceived impact of alcohol-related presentations on ED function, waiting times, other patients and staff. Results: In total, 2002 ED clinical staff completed the survey, including 904 ED nurses (45.2%) and 1016 ED doctors (50.7%). Alcohol-related verbal aggression from patients had been experienced in the past 12 months by 97.9% of respondents, and physical aggression by 92.2%. ED nurses were the group most likely to have felt unsafe because of the behaviour of these patients (92% reported such feelings). Alcohol-related presentations were perceived to negatively or very negatively affect waiting times (noted by 85.5% of respondents), other patients in the waiting room (94.4%), and the care of other patients (88.3%). Alcohol-affected patients were perceived to have a negative or very negative impact on staff workload (94.2%), wellbeing (74.1%) and job satisfaction (80.9%). Conclusions: Verbal and physical aggression by alcohol-affected patients is commonly experienced by ED clinical staff. This has a negative impact on the care of other patients, as well as on staff wellbeing. Managers of health services must ensure a safe environment for staff and patients. More importantly, a comprehensive public health approach to changing the prevailing culture that tolerates alcohol-induced unacceptable behaviour is required

Mycorrhizal community dynamics following nitrogen fertilization: A cross-site test in five grasslands. Ecol. Monogr

Abstract. Arbuscular mycorrhizal fungi (AMF) are considered both ecologically and physiologically important to many plant communities. As a result, any alteration in AMF community structure following soil nitrogen (N) enrichment may impact plant community function and contribute to widespread changes in grassland productivity. We evaluated the responses of AMF communities to N fertilization (!100 kg NÁha ) in five perennial grasslands within the Long-Term Ecological Research network to generate a broader understanding of the drivers contributing to AMF species richness and diversity with increasing soil N fertility, and subsequent effects to host-plant communities. AMF spore and hyphal community data at three mesic sites (Cedar Creek, Kellogg Biological Station, Konza Prairie) and two semiarid sites (Sevilleta, Shortgrass Steppe) were collected over two consecutive years and used to test four hypotheses about AMF responses to N fertilization. Under ambient soil N, plant annual net primary productivity and soil phosphorus (P) were strongly related to climatic differences in AMF communities (semiarid vs. mesic). Following N fertilization, the drivers of AMF community structure were soil N availability, N:P supply ratio, and host-plant photosynthetic strategy (C 3 vs. C 4 ) but not climate. In P-rich soils (low N:P), N fertilization reduced AMF productivity, species richness, and diversity and intensified AMF community convergence due to the loss of rare AMF species and the increased abundance of Glomus species. In P-limited soils (high N:P), AMF productivity, species richness, and diversity increased with N fertilization; the most responsive AMF taxa were Acaulospora, Scutellospora, and Gigaspora. Soil N or N:P 3 host-plant (C 3 , C 4 ) interactions further modified these responses: AMF hyphae (primarily Gigasporaceae) associated with C 3 plants increased in abundance with N fertilization, whereas C 4 plants hosted nitrophilous Glomus species. Such responses were independent of the duration or quantity of N fertilization, or the time since cessation of N fertilization. This synthesis provides a new understanding of AMF community patterns and processes, and it identifies three key drivers (soil N, N:P, host plant) of AMF community structure that may be tested in other communities

Using the Cardiff model to reduce late‐night alcohol‐related presentations in regional Australia

Introduction: The Cardiff model is a data sharing approach that aims to reduce the volume of intoxicated patients in emergency departments (EDs). This approach has not been tested in a rural setting. Objective: This study assessed whether this approach would reduce the number of alcohol‐associated presentations during high‐alcohol hours (HAH) in a regional ED. Design: From July 2017, people over the age of 18 attending the ED were asked by the triage nurse (1) whether they had consumed alcohol in the past 12 h, (2) their typical alcohol consumption level, (3) the location where most alcohol was purchased and (4) the location of the last drink. From April 2018, quarterly letters were sent to the top five venues reported within the ED. Deidentified, aggregated data were shared with local police, licensing authorities and local government, identifying the top five venues reported in the ED and providing a summary of alcohol‐related attendances to the ED. Interrupted time series analyses were used to estimate the influence of the intervention on monthly injury and alcohol‐related ED presentations. Findings: ITS models found that there was a significant gradual decrease in the monthly rate of injury attendances during HAH (Coefficient = −0.004, p = 0.044). No other significant results were found. Discussion: Our study found that sharing last drinks data collected in the ED with a local violence prevention committee was associated with a small, but significant reduction in the rate of injury presentations compared with all ED presentations. Conclusion: This intervention continues to have promise for reducing alcohol‐related harm

Study protocol for a randomised controlled trial of invasive versus conservative management of primary spontaneous pneumothorax

INTRODUCTION: Current management of primary spontaneous pneumothorax (PSP) is variable, with little evidence from randomised controlled trials to guide treatment. Guidelines emphasise intervention in many patients, which involves chest drain insertion, hospital admission and occasionally surgery. However, there is evidence that conservative management may be effective and safe, and it may also reduce the risk of recurrence. Significant questions remain regarding the optimal initial approach to the management of PSP

Nitrogen enrichment alters mycorrhizal allocation at five mesic to semiarid grasslands.

Abstract. Arbuscular mycorrhizal (AM) fungi are integral components of grasslands because most plants are associated with interconnected networks of AM hyphae. Mycorrhizae generally facilitate plant uptake of nutrients from the soil. However, mycorrhizal associations are known to vary in their mutualistic function, and there is currently no metric that links AM functioning with fungal colonization of roots. Mycorrhizal structures differ in their physiological and ecological functioning, so changes in AM allocation to intraradical (inside roots) and extraradical (in soil) structures may signal shifts in mycorrhizal function. We hypothesize that the functional equilibrium model applies to AM fungi and that fertilization should reduce allocation to arbuscules, coils, and extraradical hyphae, the fungal structures that are directly involved in nutrient acquisition and transfer to plants. This study compared AM responses to experimental N enrichment at five grasslands distributed across North America. Samples were collected from replicated N-enriched (and some P-enriched) and control plots throughout the growing season for three years. Intraradical AM structures were measured in over 1400 root samples, extraradical hyphal density was measured in over 590 soil samples, and spore biovolume was analyzed in over 400 soil samples. There were significant site ϫ N interactions for spore biovolume, extraradical hyphae, intraradical hyphae, and vesicles. Nitrogen enrichment strongly decreased AM structures at Cedar Creek, the site with the lowest soil N:P, and it increased AM structures at Konza Prairie, the site with the highest soil N:P. As predicted by the functional equilibrium model, in soils with sufficient P, relative allocation to arbuscules, coils, and extraradical hyphae was generally reduced by N enrichment. Allocation to spores and hyphae was most sensitive to fertilization. At the mesic sites, this response was associated with a shift in the relative abundance of Gigasporaceae within AM fungal communities. This study demonstrates that N enrichment impacts mycorrhizal allocation across a wide range of grassland ecosystems. Such changes are important because they suggest an alteration in mycorrhizal functioning that, in turn, may impact plant community composition and ecosystem function