Mapping and Zircon Geochronology of the Lyon Inlet Boundary Zone, Nunavut; a Crustal Scale Break in the Churchill Province

An important aspect of geology is the understanding of processes that created and modified continents and their resources. Knowledge of the age of formation and metamorphism of crystalline crust is thus important, and has been pursued in a recently discovered crustal-scale boundary on the southern Melville Peninsula (Nunavut, Canada) through field mapping, U-Pb zircon geochronology and electron beam analysis. This \u3e250km-long crustal feature is termed here the Lyon Inlet Boundary Zone (LIBZ). Three samples from a 15 by 20 km map area reveal a complex Archean history with the dominant granitoid unit crystallizing at 2770±38 Ma and metamorphosed at 2670±36 Ma. All samples exhibit a range of Paleoproterozoic metamorphic zircon growth events ranging from 1842±14 Ma to 1802±10 Ma. The youngest event is a minimum age for amphibolite facies metamorphism, and presumably deformation, in the LIBZ, temporally linking it to the terminal stages of Trans-Hudsonian mountain-building in arctic Canada

EVOLVING ENTITLEMENTS: INTERVENING TO PREVENT A COLLECTIVE HARM

When market transactions generate negative externalities, the injured party may initiate court action to prevent harm or to obtain compensation. The political response, in some cases, has been to broaden the set of agents who can intervene through the court, often by admitting entirely new categories of potential intervenors. We employ an experimental market setting to investigate the effect of an increase in the number of potential intervenors (introduced as admitting an additional class of persons having the necessary standing in law). The results suggest that there will be a substantial increase in the number of actual interventions. The increase means that social resources expended on interventions will increase and there may be a consequent reduction in trading activity in the affected markets.Public Economics,

VALUING THE PROTECTION OF MINIMUM INSTREAM FLOWS IN NEW MEXICO

Currently, New Mexico law does not provide any legal avenue of protecting instream flows. A change in the status quo requires that a prima facie case be made— establishing sufficient evidence of the public benefits from maintaining instream flows to warrant consideration, or standing, in future water policy deliberations. Using the contingent valuation (CV) method, we investigate the nonmarket benefits of protecting minimum instream flows in New Mexico. Results from a dichotomous choice CV telephone survey show significant nonmarket values for protecting instream flows that are sensitive to a change in scope and insensitive to a group-size reminder.Resource /Energy Economics and Policy,

A Feasibility Study Evaluating the use of Circulating Tumour DNA in Genetic tests, as a Proxy for Brain Cancer Biopsy Samples

Circulating tumour DNA (ctDNA) in the plasma represents an exciting analyte for the diagnosis and monitoring of disease in cancer patients. In a number of solid cancers types it has been shown to have clinical utility in diagnostic and molecular profiling, tracking of therapeutic response, monitoring of resistance and tumour heterogeneity and detection of post-surgical residual disease. Such clinical utility would also be of huge value in brain cancer, providing clinical information for patients where it is not currently available and/or providing an option for less invasive biopsy-dependent testing. However, its use in glioma brain cancer patients is thought to represent a particular challenge due to the reduced permeability of the blood brain barrier. Aim: This pilot study sought to investigate the practical aspects and clinical utility of using ctDNA in glioma testing in a diagnostic National Health Service laboratory; whether this analyte could be used as a proxy for the diagnostic and therapeutic decision tests performed as standard on FFPE brain biopsy samples. Additionally, the potential clinical utility of standalone metrics of cell free DNA (cfDNA) concentration was explored. Methods: Peripheral blood samples were collected from a cohort of 39 high grade glioma patients comprised of anaplastic oligodendroglioma, anaplastic astrocytoma and glioblastoma tumour sub-types. cfDNA was extracted using a magnetic bead-based protocol and its quality and quantity assessed by chip-based automated electrophoresis. Where the originating cancers harboured the appropriate biomarkers, samples were run though the Laboratory assays for Isocitrate dehydrogenase gene variant analysis, MGMT promoter methylation status and 1p/19q co-deletion testing. Results: The extraction protocol delivered cfDNA of high purity with a mean of 91% ± 5.5%, within the plasma nucleic acid fraction. For all of the tests performed, results reflected the germline DNA profile rather than the new somatic changes of the tumour. The cfDNA analysis did not pick up the tumour biomarkers seen in the paired tumour biopsy sample. However, in all cases the yield of cfDNA was too low to meet the DNA threshold concentration for the established limit of detection for assays. It was thus not possible to fully explore whether very low levels of circulating tumour DNA could be picked up as a component of the cfDNA. In a second part of the study, cfDNA concentrations for the glioblastoma cohort were assessed in the context of their clinical outcomes data. Within the limitations of the testing strategy, the data showed an interesting correlate, where high cfDNA concentration was independently associated with inferior outcome in terms of overall survival. Conclusions: In spite of the considerable advantages of looking for glioma biomarkers within the cfDNA fraction of plasma, this was currently not possible in our routine diagnostic environment. However, high cfDNA concentration in the glioblastoma sub-cohort showed a correlation with inferior outcome in terms of overall survival. Given the simplicity of obtaining this quantifiable metric, there are grounds for further investigations as to its utility; not only with survival outcomes, but also for correlation with the clinical assessment of tumour burden, blood brain barrier integrity and disease pseudoprogression

The times are they a-changing? Evolving attitudes in Australian exercise science students’ attitudes towards sports concussion

The issue of concussion in sport continues to be discussed widely in the community as current and retired players reveal personal experiences, and concerns, about the long-term sequelae of their concussive injuries. This is the first study to examine evolving attitudes and beliefs towards concussion in sport by comparing data in an Australian exercise science student cohort between 2015 and 2020. Using a repeated cross-sectional design 1,013 participants (2020 cohort: n = 751; 21.6 ± 7.1 years; 2015 cohort: n = 312; 22.0 ± 5.2 years) responded to statements about concussion: personal attitudes; the media’s portrayal; elite athletes who continue to play concussed; if participants would continue to play on concussed; and on completing rehabilitation for concussion. Comparisons revealed statistically significant differences between cohorts across the majority of statements. Specifically, more progressive attitudes were found regarding the media presentation (glorification) of concussed athletes (decreased agreement of 14.7%, p < 0.001), admiration of concussed athletes who continued to play (decreased agreement of 10.5%, p < 0.001), and rehabilitation (increased agreement of 13%, p < 0.001). However, participants still presented attitudes of wishing to continue to train or play if they had a concussion for fear of letting team-mates down, or if the injury was not noticeable. While positive attitudes are evolving, more work is required, particularly as attitudes towards concussion still appear to be situation dependent

Development and validation of a VISA tendinopathy questionnaire for greater trochanteric pain syndrome, the VISA-G

BACKGROUND Greater trochanteric pain syndrome (GTPS) is common, resulting in significant pain and disability. There is no condition specific outcome score to evaluate the degree of severity of disability associated with GTPS in patients with this condition. OBJECTIVE To develop a reliable and valid outcome measurement capable of evaluating the severity of disability associated with GTPS. METHODS A phenomenological framework using in-depth semi structured interviews of patients and medical experts, and focus groups of physiotherapists was used in the item generation. Item and format clarification was undertaken via piloting. Multivariate analysis provided the basis for item reduction. The resultant VISA-G was tested for reliability with the inter class co-efficient (ICC), internal consistency (Cronbach's Alpha), and construct validity (correlation co-efficient) on 52 naïve participants with GTPS and 31 asymptomatic participants. RESULTS The resultant outcome measurement tool is consistent in style with existing tendinopathy outcome measurement tools, namely the suite of VISA scores. The VISA-G was found to be have a test-retest reliability of ICC2,1 (95% CI) of 0.827 (0.638-0.923). Internal consistency was high with a Cronbach's Alpha of 0.809. Construct validity was demonstrated: the VISA-G measures different constructs than tools previously used in assessing GTPS, the Harris Hip Score and the Oswestry Disability Index (Spearman Rho:0.020 and 0.0205 respectively). The VISA-G did not demonstrate any floor or ceiling effect in symptomatic participants. CONCLUSION The VISA-G is a reliable and valid score for measuring the severity of disability associated GTPS.The study was funded through the Australian National University, Monash University and LaTrobe University. Prof Cook was supported by the Australian Centre for Research into Sports Injury and its Prevention, which is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee (IOC). Prof Cook is a NHMRC practitioner fellow (ID 1058493)

Benefit-Cost Analysis of FEMA Hazard Mitigation Grants

Mitigation ameliorates the impact of natural hazards on communities by reducing loss of life and injury, property and environmental damage, and social and economic disruption. The potential to reduce these losses brings many benefits, but every mitigation activity has a cost that must be considered in our world of limited resources. In principle benefit-cost analysis (BCA) can be used to assess a mitigation activity’s expected net benefits (discounted future benefits less discounted costs), but in practice this often proves difficult. This paper reports on a study that refined BCA methodologies and applied them to a national statistical sample of FEMA mitigation activities over a ten-year period for earthquake, flood, and wind hazards. The results indicate that the overall benefit-cost ratio for FEMA mitigation grants is about 4 to 1, though the ratio varies according to hazard and mitigation type.