33 research outputs found

    A note on communicating environmental change for non-market valuation

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    Communicating change in environmental condition is a critical component of non-market valuation studies. However, the underlying assumptions and implications associated with alternative ways of expressing change in environmental condition for surveys are rarely discussed in the literature. Our review found no cases where alternative formulations were both discussed and tested. In this note we report on our multi-disciplinary analysis of how best to express such change. We interrogate the meaning of, and inferences from, four formulations for quantitative expressions, or metrics, of environmental indicators that are used in the field of ecology and we then evaluate their usefulness in non-market valuation. The assumptions and limitations of each formulation are discussed using seven hypothetical cases of change in environmental condition. We show that formulations for expressing change can be grouped based on two inherent philosophies potentially held by people when they consider their preferences for environmental changes: ‘more is better philosophy’ and ‘restoration philosophy’. We contend that, without careful consideration of which philosophy people may apply, it is possible to inadvertently bias respondent choices when a particular formulation is used in a valuation study. If this happens, resulting value estimates will be a poor reflection of what researchers seek. An alternative approach that does not presuppose a philosophy but instead helps reveal a respondent’s philosophy, is proposed

    Experiences of caregivers of children with inherited metabolic diseases: a qualitative study

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    Background: We sought to understand the experiences of parents/caregivers of children with inherited metabolic diseases (IMD) in order to inform strategies for supporting patients and their families. We investigated their experiences regarding the management of disease, its impact on child and family life, and interactions with the health care system. Methods: From four Canadian centres, we conducted semi-structured telephone interviews with parents/caregivers of children with an IMD who were born between 2006 and 2015 and who were participating in a larger cohort study. Participants were selected with the aim of achieving a diverse sample with respect to treatment centre, IMD, and age of the child. Interviews emphasized the impacts of the disease and its treatment on the child and family and explicitly queried perceptions of interactions with the health care system. We identified emergent themes from the interview data. Results: We completed interviews with 21 parents/caregivers. The 21 children were aged \u3c1 to 7 years old with IMD that included amino acid disorders, urea cycle disorders, fatty acid oxidation disorders, and organic acid disorders or \u27other\u27 IMD. Most parents reported that they and their families had adapted well to their child\u27s diagnosis. Parents used proactive coping strategies to integrate complex disease management protocols into routine family life. An important source of stress was concern about the social challenges faced by their children. Participants reported positive interactions with their most involved health care providers within the metabolic clinic. However, they reported challenges associated with the health care system outside of disease-specific metabolic care, when encountering systems and providers unfamiliar with the child\u27s disease. Conclusions: The successful use of proactive coping strategies among parents of children with IMD in this study suggests the potential value of promoting positive coping and is an important direction for future study. Parents\u27 social concerns for their children were important stressors that warrant consideration by health care providers positioned to support families. Our results with respect to experiences with care highlight the important role of specialized metabolic clinics and point to a need for better coordination of the care that takes place outside the disease-specific management of IMD

    Health Care for Mitochondrial Disorders in Canada: A Survey of Physicians

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    Background: An improved understanding of diagnostic and treatment practices for patients with rare primary mitochondrial disorders can support benchmarking against guidelines and establish priorities for evaluative research. We aimed to describe physician care for patients with mitochondrial diseases in Canada, including variation in care. Methods: We conducted a cross-sectional survey of Canadian physicians involved in the diagnosis and/or ongoing care of patients with mitochondrial diseases. We used snowball sampling to identify potentially eligible participants, who were contacted by mail up to five times and invited to complete a questionnaire by mail or internet. The questionnaire addressed: personal experience in providing care for mitochondrial disorders; diagnostic and treatment practices; challenges in accessing tests or treatments; and views regarding research priorities. Results: We received 58 survey responses (52% response rate). Most respondents (83%) reported spending 20% or less of their clinical practice time caring for patients with mitochondrial disorders. We identified important variation in diagnostic care, although assessments frequently reported as diagnostically helpful (e.g., brain magnetic resonance imaging, MRI/MR spectroscopy) were also recommended in published guidelines. Approximately half (49%) of participants would recommend mitochondrial cocktails for all or most patients, but we identified variation in responses regarding specific vitamins and cofactors. A majority of physicians recommended studies on the development of effective therapies as the top research priority. Conclusions: While Canadian physicians\u27 views about diagnostic care and disease management are aligned with published recommendations, important variations in care reflect persistent areas of uncertainty and a need for empirical evidence to support and update standard protocols

    De Novo Truncating Mutations in WASF1 Cause Intellectual Disability with Seizures.

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    Next-generation sequencing has been invaluable in the elucidation of the genetic etiology of many subtypes of intellectual disability in recent years. Here, using exome sequencing and whole-genome sequencing, we identified three de novo truncating mutations in WAS protein family member 1 (WASF1) in five unrelated individuals with moderate to profound intellectual disability with autistic features and seizures. WASF1, also known as WAVE1, is part of the WAVE complex and acts as a mediator between Rac-GTPase and actin to induce actin polymerization. The three mutations connected by Matchmaker Exchange were c.1516C>T (p.Arg506Ter), which occurs in three unrelated individuals, c.1558C>T (p.Gln520Ter), and c.1482delinsGCCAGG (p.Ile494MetfsTer23). All three variants are predicted to partially or fully disrupt the C-terminal actin-binding WCA domain. Functional studies using fibroblast cells from two affected individuals with the c.1516C>T mutation showed a truncated WASF1 and a defect in actin remodeling. This study provides evidence that de novo heterozygous mutations in WASF1 cause a rare form of intellectual disability

    Bi-allelic loss-of-function variants in BCAS3 cause a syndromic neurodevelopmental disorder.

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    BCAS3 microtubule-associated cell migration factor (BCAS3) is a large, highly conserved cytoskeletal protein previously proposed to be critical in angiogenesis and implicated in human embryogenesis and tumorigenesis. Here, we established BCAS3 loss-of-function variants as causative for a neurodevelopmental disorder. We report 15 individuals from eight unrelated families with germline bi-allelic loss-of-function variants in BCAS3. All probands share a global developmental delay accompanied by pyramidal tract involvement, microcephaly, short stature, strabismus, dysmorphic facial features, and seizures. The human phenotype is less severe compared with the Bcas3 knockout mouse model and cannot be explained by angiogenic defects alone. Consistent with being loss-of-function alleles, we observed absence of BCAS3 in probands' primary fibroblasts. By comparing the transcriptomic and proteomic data based on probands' fibroblasts with those of the knockout mouse model, we identified similar dysregulated pathways resulting from over-representation analysis, while the dysregulation of some proposed key interactors could not be confirmed. Together with the results from a tissue-specific Drosophila loss-of-function model, we demonstrate a vital role for BCAS3 in neural tissue development

    Testing temporal stability of recreation values

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    Temporal stability of non-market values help to demonstrate the validity of value estimates and the reliability of benefit transfers, however evidence of value stability over time is limited. A literature review focused on meta-analysis studies shows that it is standard practice to adjust values for CPI changes between temporal periods, but that in about half of cases additional value increases over time were identified as significant. One implication is that benefit transfer may not be reliable in those cases. In this study temporal stability of recreation values for the Coorong in Australia has been assessed by travel cost model (TCM) and contingent valuation (CVM) experiments repeated seven years apart. The case study results identified temporal transfer errors were larger with the TCM (62%) than with the CVM (19%). Testing showed that the TCM models and values were significantly different over the seven year period, but the CVM models and values were not, even though the same recreation good was involved. These mixed results indicate that stated preference values may be less sensitive to temporal effects than revealed preference values. © 2019 Elsevier B.V

    Testing for convergent validity between travel cost and contingent valuation estimates of recreation values in the Coorong, Australia

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    A number of studies valuing recreation have shown that the travel cost method (TCM) generates higher estimates of value than the contingent valuation method (CVM), even though the latter is commonly associated with potential problems of hypothetical and strategic bias. In this study both methods have been used to estimate the recreational values associated with the Coorong on the Murray River in south-eastern Australia. Values per adult visitor per recreation day are estimated with the TCM at 212andwiththeCVMat212 and with the CVM at 115. A number of methodological and framing issues to explain these value differences are tested. In summary, while no single methodological or framing issue could be identified that would reconcile the difference between TCM and CVM values, it appears likely that there may be a combination of factors that drive the systematic variations in consumer surplus values. The evidence in this study suggests that the most important of these are likely to be the different decision points underpinning data collection, and the consideration of substitute sites, strategic responses, and the treatment of uncertain responses within the CVM

    Valuing recreation in the Coorong, Australia, with travel cost and contingent behaviour models

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    The study reported in this article is focused on estimating recreational values associated with the Coorong in South Australia. Count data models extended with contingent behaviour (CB) questions have been used to assess recreation values as well as sensitivity to changed access conditions. A recreation value of 111peradultvisitorperdayhasbeenestimated,whichcanbeextrapolatedtoaconsumersurplusofapproximately111 per adult visitor per day has been estimated, which can be extrapolated to a consumer surplus of approximately 30.5 million per annum at the site. Random coefficient negative binomial models have been applied to the CB data, with results indicating that a marginal value of at least $17.20 per person per trip is attached to each 1 per cent change in access

    A note on communicating environmental change for non-market valuation

    No full text
    Communicating change in environmental condition is a critical component of non-market valuation studies. However, the underlying assumptions and implications associated with alternative ways of expressing change in environmental condition for surveys are rarely discussed in the literature. Our review found no cases where alternative formulations were both discussed and tested. In this note we report on our multi-disciplinary analysis of how best to express such change. We interrogate the meaning of, and inferences from, four formulations for quantitative expressions, or metrics, of environmental indicators that are used in the field of ecology and we then evaluate their usefulness in non-market valuation. The assumptions and limitations of each formulation are discussed using seven hypothetical cases of change in environmental condition. We show that formulations for expressing change can be grouped based on two inherent philosophies potentially held by people when they consider their preferences for environmental changes: ‘more is better philosophy’ and ‘restoration philosophy’. We contend that, without careful consideration of which philosophy people may apply, it is possible to inadvertently bias respondent choices when a particular formulation is used in a valuation study. If this happens, resulting value estimates will be a poor reflection of what researchers seek. An alternative approach that does not presuppose a philosophy but instead helps reveal a respondent’s philosophy, is proposed.This work was supported by the Murray-Darling Basin Futures Collaborative Research Networ

    Incidence of medium-chain acyl-CoA dehydrogenase deficiency in Canada using the Canadian Paediatric Surveillance Program: Role of newborn screening

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    BACKGROUND: The incidence of medium-chain acyl-CoA dehydrogenase deficiency (MCADD) was estimated using the Canadian Paediatric Surveillance Program (CPSP) in Canada over a three-year period. Data regarding mutations associated with MCADD cases were collected wherever available. METHODS: Data were collected over a 36-month period using a monthly mailed questionnaire distributed through the CPSP to more than 2500 Canadian paediatricians, medical geneticists and paediatric pathologists. RESULTS AND CONCLUSIONS: During the three years of MCADD surveillance, 46 confirmed cases out of a total of 71 reported cases were found - an average of approximately 15 cases per year. This rate is lower than the initial estimate of approximately 30 cases per year of MCADD in Canada, based on the reported incidence of MCADD in the literature of approximately one in 10,000 to one in 20,000. All cases ascertained by newborn screening were asymptomatic. There were two deaths, both in jurisdictions without newborn screening for MCADD. The data support population-based newborn screening for MCADD. ©2012 Pulsus Group Inc. All rights reserved
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