Constructional Volcanic Edifices on Mercury: Candidates and Hypotheses of Formation

Mercury, a planet with a predominantly volcanic crust, has perplexingly few, if any, constructional volcanic edifices, despite their common occurrence on other solar system bodies with volcanic histories. Using image and topographical data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, we describe two small (< 15 km‐diameter) prominences with shallow summit depressions associated with volcanically flooded impact features. We offer both volcanic and impact‐related interpretations for their formation, and then compare these landforms with volcanic features on Earth and the Moon. Though we cannot definitively conclude that these landforms are volcanic, the paucity of constructional volcanic edifices on Mercury is intriguing in itself. We suggest that this lack is because volcanic eruptions with sufficiently low eruption volumes, rates, and flow lengths, suitable for edifice construction, were highly spatiotemporally restricted during Mercury's geological history. We suggest that volcanic edifices may preferentially occur in association with late‐stage, post‐impact effusive volcanic deposits. The ESA/JAXA BepiColombo mission to Mercury will be able to investigate further our candidate volcanic edifices, search for other, as‐yet unrecognized edifices beneath the detection limits of MESSENGER data, and test our hypothesis that edifice construction is favored by late‐stage, low‐volume effusive eruptions

Valuing the biodiversity gains from protecting native plant communities from bitou bush (Chrysanthemoides monilifera subsp rotundata (DC.) T.Norl.) in New South Wales: application of the defensive expenditure method

Valuation of the gains from protection of biodiversity is difficult because the services that provide the benefits do not normally pass through markets where prices can form. But the services sometimes pass through markets where consumers or producers behave in a market-oriented manner, and so the values implicit in this behaviour can be identified and derived. Estimates of the benefits of biodiversity protection are derived from the costs of protecting native plant communities from a major weed in Australia, by following this approach. In 1999, invasion of coastal areas of New South Wales by bitou bush (Chrysanthemoides monilifera subsp. rotundata (DC.) T. Norl.) was listed as a key process threatening native plants under the NSW Threatened Species Conservation Act 1995. In accordance with the Act, the Department of Environment and Climate Change prepared a Threat Abatement Plan (TAP) to reduce the impacts of bitou bush on biodiversity at each threatened site. The costs of protecting sites vary closely with the number of priority native species and communities at each site. Following standard economic assumptions about market transactions, these costs are interpreted to provide values the benefits of protecting extra species, communities, and sites. Key words: Bitou bush, Chrysanthemoides monilifera, threat abatement plan, valuation of biodiversity, benefit-cost analysis, weed control, defensive-expenditure method.Bitou bush, Chrysanthemoides monilifera, threat abatement plan, valuation of biodiversity, benefit-cost analysis, weed control, defensive-expenditure method, Demand and Price Analysis, Environmental Economics and Policy,

Eradication of Exotic Weeds in Australia: Comparing Effort and Expenditure

Weeds have many adverse impacts on agriculture and the environment and therefore are often targets of eradication attempts. Eradication attempts involve large commitments of labour and financial resources over significant periods of time. Using data from 12 Australian weed eradication attempts the authors compare work hours and expenditure on each attempt for various initial-infestation sizes. Analysis of a limited data set shows: (1) that while the eradication effort increases with the initial area of infestation, the effort applied per hectare actually decreases; (2) that application of a greater work effort was not the reason why completed eradications were successful; and (3) that the larger the initial infestation size, the smaller the amount of resources applied per hectare for eradication.weeds, eradication, work effort, expenditure, infestation size, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Factors influencing decision making in neonatology: inhaled nitric oxide in preterm infants.

ObjectiveWe studied decision making regarding inhaled nitric oxide (iNO) in preterm infants with Pulmonary Hypertension (PH).Study designWe asked members of the AAP-Society of Neonatal-Perinatal Medicine and Division-Chiefs to select from three management options- initiate iNO, engage parents in shared decision making or not consider iNO in an extremely preterm with PH followed by rating of factors influencing their decision.ResultsThree hundred and four respondents (9%) completed the survey; 36.5% chose to initiate iNO, 42% to engage parents, and 21.5% did not consider iNO. Provider's prior experience, safety, and patient-centered care were rated higher by those who initiated or offered iNO; lack of effectiveness and cost considerations by participants who did not chose iNO.ConclusionsMost neonatologists offer or initiate iNO therapy based on their individual experience. The minority who chose not to consider iNO placed higher value on lack of effectiveness and cost. These results demonstrate a tension between evidence and pathophysiology-based-therapy/personal experience

Critical Approach to Reflexivity in Grounded Theory

A problem with the popular desire to legitimate one’s research through the inclusion of reflexivity is its increasingly uncritical adoption and practice, with most researchers failing to define their understandings, specific positions, and approaches. Considering the relative recentness with which reflexivity has been explicitly described in the context of grounded theory, guidance for incorporating it within this research approach is currently in the early stages. In this article, we illustrate a three-stage approach used in a grounded theory study of how parents of children with autism navigate intervention. Within this approach, different understandings of reflexivity are first explored and mapped, a methodologically consistent position that includes the aspects of reflexivity one will address is specified, and reflexivity-related observations are generated and ultimately reported. According to the position specified, we reflexively account for multiple researcher influences, including on methodological decisions, participant interactions and data collection, analysis, writing, and influence of the research on the researcher. We hope this illustrated approach may serve both as a potential model for how researchers can critically design and implement their own context-specific approach to reflexivity, and as a stimulus for further methodological discussion of how to incorporate reflexivity into grounded theory research