The exposed Mule Creek vent deposits record the structure of a volcanic conduit during a hybrid explosive–effusive eruption

Silicic volcanic eruptions commonly begin with the explosive ejection of pyroclastic material, before transitioning to gentler effusion-dominated activity. Well-exposed dissected silicic systems are scarce and poorly studied, hindering the advances in our understanding of the explosive–effusive transition needed to improve interpretations of volcanic unrest and hazard forecasting. The Mule Creek vent (New Mexico, USA) is a dissected silicic conduit that records the processes controlling conduit formation and evolution, and the role tuffisites (fractures filled with variably welded pyroclasts) play in conduit dynamics. Here, we use decimeter-scale photo-mapping of lithostratigraphic units and thin section analysis to differentiate and interpret three dominant emplacement styles during vent evolution. First, there was repeated deposition and erosion of pyroclastic material at the conduit walls, recorded by erosive surfaces in pyroclastic breccia and agglomerates at the conduit margins. Second, sub-vertical domains of dense melt-dominated magma were emplaced and preserved as glass-dominated vitrophyre and brecciated vitrophyre, with the textural hallmarks of assembly from welding of pyroclasts. Finally, the sub-horizontal fracturing of previously deposited lithologies produced laterally cross-cutting tuffisites. The vent deposits track the widening and then narrowing of the conduit through time and reflect progressive insulation and generally higher temperatures towards the conduit center as pyroclasts accumulate. Welding of pyroclastic fill and the formation of dense vitrophyres towards the conduit center lowers deposit porosity and effective wall permeability. This drives localized gas pressure increases and results in gas-driven fracturing, generating tuffisites, which act as transient outgassing pathways. The structure of the Mule Creek vent records an explosive–effusive transition, constraining the processes controlling conduit evolution and aiding our interpretation of volcanic unrest

Sustainability, systems thinking and professional practice

This article explores the impact of the new sustainability agenda on the occupational and professional needs of those who have taken educational and training programmes in the environmental field either at undergraduate or postgraduate level or through relevant professional institutions' continuing professional development programmes. It also describes a one-day workshop for the professionals on sustainable development, based on systems thinking and practice. The workshop provides a model for developing greater understanding and effective action in professional practice, by using dialogue and interprofessional learning to explore approaches to sustainability in a variety of business and professional contexts. It introduces the principles underpinning the concept of sustainability and provides tools to support the integration of sustainable development into professional practice and organisational change

Automated detection and location of tectonic tremor along the entire Cascadia margin from 2005 to 2011

We have constructed an automated routine to identify prominent bursts of tectonic tremor and locate their source region during time periods of raised amplitude in the tremor passband. This approach characterizes 62 episodes of tectonic tremor between 2005 and 2011, with tremor epicenters forming a narrow band spanning the entire length of the Cascadia Subduction Zone. We find a range of along-strike lengths in individual episodes, but the length appears proportional to both duration and geodetic moment, consistent with proposed scaling laws for slow earthquake phenomena. Examination of individual episodes in detail reveals intriguing updip-downdip migration patterns, including slow updip migration during initiation and repetitive downdip migration between different episodes. The broader catalog of tremor episodes refines the inferences from earlier work that episodic tremor and slip is segmented along-strike and correlated with apparent seismogenic zone segmentation based on the distribution of fore-arc basins and geologic terranes. The overall band of tremor is offset ~50 km from the downdip edge of interseismic coupling along the central and northern parts of the subduction zone. Along the southern part of the subduction zone, it is adjacent to this boundary, suggesting that the locked and transition zones may be more closely linked in southern Cascadia

Nonprofits and business:toward a subfield of nonprofit studies

Although the field of nonprofit studies now encompasses a substantial body of literature on the relationship between governmental and nonprofit organizations, the relationship between the business and nonprofit sectors has been less addressed by specialist nonprofit scholars. This Research Note aims to encourage further studies by nonprofit scholars of the business-nonprofit sector relationship. It looks at descriptive evidence to date, proposes a tentative resource-based framework for understanding how nonprofits and business relate to each other in practice and suggests some initial directions for developing a subfield within nonprofit studies

Following the funding trail: Financing, nurses and teamwork in Australian general practice

Contains fulltext : 97927.pdf (publisher's version ) (Open Access)BACKGROUND: Across the globe the emphasis on roles and responsibilities of primary care teams is under scrutiny. This paper begins with a review of general practice financing in Australia, and how nurses are currently funded. We then examine the influence on funding structures on the role of the nurse. We set out three dilemmas for policy-makers in this area: lack of an evidence base for incentives, possible untoward impacts on interdisciplinary functioning, and the substitution/enhancement debate. METHODS: This three year, multimethod study undertook rapid appraisal of 25 general practices and year-long studies in seven practices where a change was introduced to the role of the nurse. Data collected included interviews with nurses (n = 36), doctors (n = 24), and managers (n = 22), structured observation of the practice nurse (51 hours of observation), and detailed case studies of the change process in the seven year-long studies. RESULTS: Despite specific fee-for-service funding being available, only 6% of nurse activities generated such a fee. Yet the influence of the funding was to focus nurse activity on areas that they perceived were peripheral to their roles within the practice. CONCLUSIONS: Interprofessional relationships and organisational climate in general practices are highly influential in terms of nursing role and the ability of practices to respond to and utilise funding mechanisms. These factors need to be considered, and the development of optimal teamwork supported in the design and implementation of further initiatives that financially support nursing in general practice