Permafrost thaw induces short-term increase in vegetation productivity in northwestern Canada.

Over the past several decades, various trends in vegetation productivity, from increases to decreases, have been observed throughout Arctic-Boreal ecosystems. While some of this variation can be explained by recent climate warming and increased disturbance, very little is known about the impacts of permafrost thaw on productivity across diverse vegetation communities. Active layer thickness data from 135 permafrost monitoring sites along a 10° latitudinal transect of the Northwest Territories, Canada, paired with a Landsat time series of normalized difference vegetation index from 1984 to 2019, were used to quantify the impacts of changing permafrost conditions on vegetation productivity. We found that active layer thickness contributed to the observed variation in vegetation productivity in recent decades in the northwestern Arctic-Boreal, with the highest rates of greening occurring at sites where the near-surface permafrost recently had thawed. However, the greening associated with permafrost thaw was not sustained after prolonged periods of thaw and appeared to diminish after the thaw front extended outside the plants' rooting zone. Highest rates of greening were found at the mid-transect sites, between 62.4° N and 65.2° N, suggesting that more southernly sites may have already surpassed the period of beneficial permafrost thaw, while more northern sites may have yet to reach a level of thaw that supports enhanced vegetation productivity. These results indicate that the response of vegetation productivity to permafrost thaw is highly dependent on the extent of active layer thickening and that increases in productivity may not continue in the coming decades.

Material Legacies and Environmental Constraints Underlie Fire Resilience of a Dominant Boreal Forest Type.

Resilience of plant communities to disturbance is supported by multiple mechanisms, including ecological legacies affecting propagule availability, species' environmental tolerances, and biotic interactions. Understanding the relative importance of these mechanisms for plant community resilience supports predictions of where and how resilience will be altered with disturbance. We tested mechanisms underlying resilience of forests dominated by black spruce (Picea mariana) to fire disturbance across a heterogeneous forest landscape in the Northwest Territories, Canada. We combined surveys of naturally regenerating seedlings at 219 burned plots with experimental manipulations of ecological legacies via seed addition of four tree species and vertebrate exclosures to limit granivory and herbivory at 30 plots varying in moisture and fire severity. Black spruce recovery was greatest where it dominated pre-fire, at wet sites with deep residual soil organic layers, and fire conditions of low soil or canopy combustion and longer return intervals. Experimental addition of seed indicated all species were seed-limited, emphasizing the importance of propagule legacies. Black spruce and birch (Betula papyrifera) recruitment were enhanced with vertebrate exclusion. Our combination of observational and experimental studies demonstrates black spruce is vulnerable to effects of increased fire activity that erode ecological legacies. Moreover, black spruce relies on wet areas with deep soil organic layers where other species are less competitive. However, other species can colonize these areas if enough seed is available or soil moisture is altered by climate change. Testing mechanisms underlying species' resilience to disturbance aids predictions of where vegetation will transform with effects of climate change. Supplementary Information: The online version contains supplementary material available at 10.1007/s10021-022-00772-7.

Climate-informed forecasts reveal dramatic local habitat shifts and population uncertainty for northern boreal caribou.

Most research on boreal populations of woodland caribou (Rangifer tarandus caribou) has been conducted in areas of high anthropogenic disturbance. However, a large portion of the species' range overlaps relatively pristine areas primarily affected by natural disturbances, such as wildfire. Climate-driven habitat change is a key concern for the conservation of boreal-dependent species, where management decisions have yet to consider knowledge from multiple ecological domains integrated into a cohesive and spatially explicit forecast of species-specific habitat and demography. We used a novel ecological forecasting framework to provide climate-sensitive projections of habitat and demography for five boreal caribou monitoring areas within the Northwest Territories (NWT), Canada, over 90 years. Importantly, we quantify uncertainty around forecasted mean values. Our results suggest habitat suitability may increase in central and southwest regions of the NWT's Taiga Plains ecozone but decrease in southern and northwestern regions driven by conversion of coniferous to deciduous forests. We do not project that boreal caribou population growth rates will change despite forecasted changes to habitat suitability. Our results emphasize the importance of efforts to protect and restore northern boreal caribou habitat despite climate uncertainty while highlighting expected spatial variations that are important considerations for local people who rely on them. An ability to reproduce previous work, and critical thought when incorporating sources of uncertainty, will be important to refine forecasts, derive management decisions, and improve conservation efficacy for northern species at risk.

"I still have issues with pronunciation of words": A mixed methods investigation of the psychosocial and speech effects of Childhood Apraxia of Speech in adults.

PURPOSE: Adolescents with Childhood Apraxia of Speech (CAS) are likely to have persistent speech errors compared to non-CAS peers (Lewis et al., 2018) and may have ongoing psychosocial issues (e.g. Carrigg, Parry, Baker, Shriberg, & Ballard, 2016). Beyond this, little is known about the long-term consequences of CAS in adulthood. This study explored whether adults who were reported to have had CAS as children have ongoing psychosocial or speech impacts. METHOD: A cross-sectional descriptive design, with mixed-method analyses of demographic, psychosocial, and speech data was used. Data were collected via a four-part online survey. Part one consisted of questions about demographic information and participants' self-reported performance in speech, language and literacy. Parts two and three investigated the psychosocial impacts of CAS using the Brief Fear of Negative Evaluation Scale - Revised (BFNE- R) and The State-Trait Anxiety Inventory (STAI). Part four collected single word and connected speech data via an online audio recording, which was then transcribed following the Connected Speech Transcription Protocol (CoST-P). Analyses of speech characteristics reported in CAS was completed using Phon software. RESULT: There were 17 participants in part one, 16 in parts two and three, and six in part four. Participants reported elevated levels of state (p = 0.01) and trait (p = 0.0001) anxiety compared to normative data. Ongoing segmental and suprasegmental speech errors were observed, with a significant difference between percent phonemes correct in single words versus connected speech (p = 0.03). Participants who provided a speech sample had difficulty with correct stress, use of juncture, and had increased intra- and inter-word segregation. Participants with better speech reported less anxiety. CONCLUSION: Psychosocial effects and speech characteristics associated with CAS in childhood appear to persist into adulthood. Confirmation of these results and research to determine treatment and psychosocial support needs past early childhood is warranted.

Confounding adjustment methods for multi-level treatment comparisons under lack of positivity and unknown model specification.

Imbalances in covariates between treatment groups are frequent in observational studies and can lead to biased comparisons. Various adjustment methods can be employed to correct these biases in the context of multi-level treatments (> 2). Analytical challenges, such as positivity violations and incorrect model specification due to unknown functional relationships between covariates and treatment or outcome, may affect their ability to yield unbiased results. Such challenges were expected in a comparison of fire-suppression interventions for preventing fire growth. We identified the overlap weights, augmented overlap weights, bias-corrected matching and targeted maximum likelihood as methods with the best potential to address those challenges. A simple variance estimator for the overlap weight estimators that can naturally be combined with machine learning is proposed. In a simulation study, we investigated the performance of these methods as well as those of simpler alternatives. Adjustment methods that included an outcome modeling component performed better than those that focused on the treatment mechanism in our simulations. Additionally, machine learning implementation was observed to efficiently compensate for the unknown model specification for the former methods, but not the latter. Based on these results, we compared the effectiveness of fire-suppression interventions using the augmented overlap weight estimator.

PERFICT: A Re-imagined foundation for predictive ecology.

Making predictions from ecological models-and comparing them to data-offers a coherent approach to evaluate model quality, regardless of model complexity or modelling paradigm. To date, our ability to use predictions for developing, validating, updating, integrating and applying models across scientific disciplines while influencing management decisions, policies, and the public has been hampered by disparate perspectives on prediction and inadequately integrated approaches. We present an updated foundation for Predictive Ecology based on seven principles applied to ecological modelling: make frequent Predictions, Evaluate models, make models Reusable, Freely accessible and Interoperable, built within Continuous workflows that are routinely Tested (PERFICT). We outline some benefits of working with these principles: accelerating science; linking with data science; and improving science-policy integration.

A new training package (3Cs: Connect, Communicate and Collaborate) for improving family responsive service delivery in early intervention for children with hearing loss: A proof of concept study.

BACKGROUND: An objective of early intervention for children with hearing loss is to enhance family engagement in therapy to maximise a child's speech and language potential. However, requiring a service provider to work collaboratively with a child's family can create problems in developing and underdeveloped countries, where skilled service providers and services for children with hearing loss are lacking and where an expert model of intervention prevails. OBJECTIVES: To determine the preliminary effectiveness of a new training package Connect, Communicate and Collaborate (3Cs), in improving the knowledge and confidence of service providers in the delivery of family responsive services in an early intervention program for children with hearing loss. METHODS: Five learning modules were developed based on service provider experience working with children with hearing loss, and parents of children with hearing loss. Six participants completed the training package comprising five training modules and an introductory session over a 6-week period. Participants' confidence and knowledge in providing family responsive practice was measured pre and post training using visual analogue scales, and participants were also invited to provide their reflections on the program. RESULTS: Pre- and post-training confidence ratings revealed significant improvements in the perceptions of participants in the implementation of responsive family practice across four of five of programme learning modules (p < 0.002). Participant reflection statements indicate they became more considerated in their family responsive practice. Despite positive experiences working with parents, participants stated they had ongoing difficulties guiding families through the decision-making processes of habilitation. The reflection process assisted learning and improved practice by supporting participants to build on their strengths. CONCLUSION: The 3Cs package improved the confidence in and knowledge of delivery of responsive family services for six participants in Kuwait. It also improved the participant's self-evaluation skills. The 3Cs provides professional development that meets the needs of service providers working with children with hearing loss to improve inclusion of families in the therapy process.

Integrating functional connectivity in designing networks of protected areas under climate change: A caribou case-study.

Land-use change and climate change are recognized as two main drivers of the current biodiversity decline. Protected areas help safeguard the landscape from additional anthropogenic disturbances and, when properly designed, can help species cope with climate change impacts. When designed to protect the regional biodiversity rather than to conserve focal species or landscape elements, protected areas need to cover a representative sample of the regional biodiversity and be functionally connected, facilitating individual movements among protected areas in a network to maximize their effectiveness. We developed a methodology to define effective protected areas to implement in a regional network using ecological representativeness and functional connectivity as criteria. We illustrated this methodology in the Gaspésie region of Québec, Canada. We simulated movements for the endangered Atlantic-Gaspésie caribou population (Rangifer tarandus caribou), using an individual-based model, to determine functional connectivity based on this large mammal. We created multiple protected areas network scenarios and evaluated their ecological representativeness and functional connectivity for the current and future conditions. We selected a subset of the most effective network scenarios and extracted the protected areas included in them. There was a tradeoff between ecological representativeness and functional connectivity for the created networks. Only a few protected areas among those available were repeatedly chosen in the most effective networks. Protected areas maximizing both ecological representativeness and functional connectivity represented suitable areas to implement in an effective protected areas network. These areas ensured that a representative sample of the regional biodiversity was covered by the network, as well as maximizing the movement over time between and inside the protected areas for the focal population.

Principles of disability support in rural and remote Australia: Lessons from parents and carers.

This study describes the understanding, experiences and expectations of families living in rural and remote Australia regarding core concepts relating to disability service provision, including person-centred practice (PCP), family-centred practice (FCP), transdisciplinary practice (TDP), choice, control, inclusion, and equity. Thirteen parents or carers, each with a child with an intellectual disability aged between 6 and 16 years, living in rural and remote areas as described by the Australian Standard Geographical Classification - Remoteness Area (ASGC-RA) and Modified Monash Model (MMM) - were recruited through distribution of flyers (hard copies or by email) to clinicians, schools, and advocacy agencies. Semi-structured interviews were conducted with participants either in-person or via telephone between July and October 2015. Data were analysed using thematic analysis. Participants reported that their understanding of many of the disability principles (PCP, FCP, choice, control, inclusion, and equity) was different from providers, and that many providers struggled to understand families, and therefore they did not share meaning of the principles of best practice disability supports. Families did not identify transdisciplinary practice as a core issue or tenet of effective service delivery. Families also reported experiences of missing out on services, feeling a sense of isolation in their communities, struggling to access skilled therapists, and difficulty finding supports and goals that were relevant to their child. The quality of supports that these families accessed was often below the standard that they expected. They did not expect that support standards will change in rural and remote Australia, so many have very low expectations of the National Disability Insurance Scheme (NDIS) in the future. Although more data will need to be collected as the NDIS and its markets mature, these data show that many rural and remote participants and their supporters have a variety of concerns about how they will access quality allied health services through the Scheme.

Parents' views about factors facilitating their involvement in the oral early intervention services provided for their children with hearing loss in Kuwait.

OBJECTIVES: Developed countries (such as the Unites States of America, the United Kingdom, and Australia) provide high-quality services to children with hearing loss and their parents, including universal newborn hearing screening, early fitting of hearing devices and access to high quality early, aural intervention. In contrast, many developing countries lack the resources to provide these services. Research evidence suggests that one way to compensate for delays in identification and rehabilitation for children with hearing loss is to involve the family in the early intervention process. However, evidence is deficient around the facilitation of parental involvement in early intervention for families from developing countries. The aim of this study was to investigate the perception of parents from a developing country who have a child with hearing loss to discover the factors that may influence their involvement in early intervention, identify facilitators/barriers for their involvement, and identify the specific needs of involved parents. METHOD: A qualitative collective case study methodology was used in the form of semi-structured interviews with twenty-one participants. RESULTS: Two global themes emerged. Firstly, factors influencing parental involvement. This included five subthemes: better communication as the key to building rapport and providing support; disappointment with the service; physical and human resources make a difference; consideration of life beyond the habilitation sessions; and my child matters the most. The second global theme-parental needs-included four subthemes: building trust; ensuring generalization; improving child outcomes; and managing needs of parents versus services. All the discussed themes are supported by quotations from the interviews. CONCLUSION: The findings suggest that parents of children with hearing loss in developing countries perceive the services provided for their children to be disjointed and not well coordinated. Based on the parent perceptions a set of guidelines that provide a scaffold for service providers working with children with hearing loss in developing countries is outlined. The guidelines are designed to assist services for children with hearing loss in developing countries improve the delivery of their services and increase family involvement, which in turn; will assist in improving their child and family related outcomes.

Increasing wildfires threaten historic carbon sink of boreal forest soils.

Boreal forest fires emit large amounts of carbon into the atmosphere primarily through the combustion of soil organic matter1-3. During each fire, a portion of this soil beneath the burned layer can escape combustion, leading to a net accumulation of carbon in forests over multiple fire events4. Climate warming and drying has led to more severe and frequent forest fires5-7, which threaten to shift the carbon balance of the boreal ecosystem from net accumulation to net loss1, resulting in a positive climate feedback8. This feedback will occur if organic-soil carbon that escaped burning in previous fires, termed 'legacy carbon', combusts. Here we use soil radiocarbon dating to quantitatively assess legacy carbon loss in the 2014 wildfires in the Northwest Territories of Canada2. We found no evidence for the combustion of legacy carbon in forests that were older than the historic fire-return interval of northwestern boreal forests9. In forests that were in dry landscapes and less than 60 years old at the time of the fire, legacy carbon that had escaped burning in the previous fire cycle was combusted. We estimate that 0.34 million hectares of young forests (<60 years) that burned in the 2014 fires could have experienced legacy carbon combustion. This implies a shift to a domain of carbon cycling in which these forests become a net source-instead of a sink-of carbon to the atmosphere over consecutive fires. As boreal wildfires continue to increase in size, frequency and intensity7, the area of young forests that experience legacy carbon combustion will probably increase and have a key role in shifting the boreal carbon balance.

Compensatory conservation measures for an endangered caribou population under climate change.

Future human land use and climate change may disrupt movement behaviors of terrestrial animals, thereby altering the ability of individuals to move across a landscape. Some of the expected changes result from processes whose effects will be difficult to alter, such as global climate change. We present a novel framework in which we use models to (1) identify the ecological changes from these difficult-to-alter processes, as well as (2) the potential conservation measures that are best able to compensate for these changes. We illustrated this framework with the case of an endangered caribou population in Québec, Canada. We coupled a spatially explicit individual-based movement model with a range of landscape scenarios to assess the impacts of varying degrees of climate change, and the ability of conservation actions to compensate for such impacts on caribou movement behaviors. We found that (1) climate change impacts reduced movement potential, and that (2) the complete restoration of secondary roads inside protected areas was able to fully offset this reduction, suggesting that road restoration would be an effective compensatory conservation action. By evaluating conservation actions via landscape use simulated by an individual-based model, we were able to identify compensatory conservation options for an endangered species facing climate change.

Cross-scale controls on carbon emissions from boreal forest megafires.

Climate warming and drying is associated with increased wildfire disturbance and the emergence of megafires in North American boreal forests. Changes to the fire regime are expected to strongly increase combustion emissions of carbon (C) which could alter regional C balance and positively feedback to climate warming. In order to accurately estimate C emissions and thereby better predict future climate feedbacks, there is a need to understand the major sources of heterogeneity that impact C emissions at different scales. Here, we examined 211 field plots in boreal forests dominated by black spruce (Picea mariana) or jack pine (Pinus banksiana) of the Northwest Territories (NWT), Canada after an unprecedentedly large area burned in 2014. We assessed both aboveground and soil organic layer (SOL) combustion, with the goal of determining the major drivers in total C emissions, as well as to develop a high spatial resolution model to scale emissions in a relatively understudied region of the boreal forest. On average, 3.35 kg C m-2 was combusted and almost 90% of this was from SOL combustion. Our results indicate that black spruce stands located at landscape positions with intermediate drainage contribute the most to C emissions. Indices associated with fire weather and date of burn did not impact emissions, which we attribute to the extreme fire weather over a short period of time. Using these results, we estimated a total of 94.3 Tg C emitted from 2.85 Mha of burned area across the entire 2014 NWT fire complex, which offsets almost 50% of mean annual net ecosystem production in terrestrial ecosystems of Canada. Our study also highlights the need for fine-scale estimates of burned area that represent small water bodies and regionally specific calibrations of combustion that account for spatial heterogeneity in order to accurately model emissions at the continental scale.

Patient education using virtual reality increases knowledge and positive experience for breast cancer patients undergoing radiation therapy.

PURPOSE: Improved access to technology in the radiation therapy (RT) workforce education has resulted in opportunities for innovative patient education methods. This study investigated the impact of a newly developed education tool using the Virtual Environment for Radiotherapy Training (VERT) system on patients' RT knowledge and anxiety. METHOD: Breast cancer patients were recruited into a control group (CG) (n = 18) who underwent the standard pre-RT education package at a targeted cancer therapy centre, followed by a VERT group (VG) (n = 19). VG patients attended a VERT-based education session detailing RT immobilisation, planning and treatment. All patients completed questionnaires at four time points throughout their treatment, with survey sub-sections on RT knowledge, experience and anxiety. RESULTS: For both groups, anxiety levels were highest at time point 1(T1 after initial radiation oncologist consultation) (CG, 41.2; VG, 43.1), with a gradual decrease observed thereafter at time points before simulation, at the beginning of treatment and at the end of treatment (p > 0.05). The VG's RT knowledge scores were statistically significantly higher than those of the CG scores at all time points following VERT education (p < 0.05). CONCLUSION: This study reports the high value of VERT breast cancer-targeted education programs in improving RT knowledge and perhaps decreasing patient anxiety. Continued efforts are required to improve patients' accessibility to VERT in Australia, and to better understand the effect of VERT's unique educational features on patients' emotional and physical needs throughout their RT.

Getting comfortable with "comfort feeding": An exploration of legal and ethical aspects of the Australian speech-language pathologist's role in palliative dysphagia care.

PURPOSE: With an ageing population, speech-language pathologists (SLPs) can expect to encounter legal and ethical challenges associated with palliative and end-of-life care more frequently. An awareness of the medico-legal and ethical framework for palliative dysphagia management will better equip SLPs to work effectively in this area. METHOD: This narrative review examines a range of legislation, legal, ethical and SLP literature that is currently available to orient SLPs to legal and ethical palliative dysphagia management in the Australian context. RESULT: Relevant legal and ethical considerations in palliative and end-of-life care are described. CONCLUSION: SLPs have a role in palliative dysphagia management, however, this can involve unique legal and ethical challenges. The legal position on provision and cessation of nutrition and hydration differs between Australian States and Territories. Decisions by the courts have established a body of relevant case law. This article introduces SLPs to some of the important considerations for legal and ethical palliative care, but is not intended to be directive. SLPs are encouraged to explore their local options for ethical and medico-legal guidance. It is hoped that increasing SLPs awareness of many of the concepts discussed in this article enhances the provision of high-quality patient-centred care.

Survival analysis and classification methods for forest fire size.

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

Cognitive Impairment in Rheumatoid Arthritis: A Systematic Review.

OBJECTIVE: Rheumatoid arthritis (RA) is not commonly associated with central nervous system and brain changes. However, a number of studies have reported high rates of cognitive impairment in adults with RA. The objective of this systematic review was to identify and explore the rates and types of cognitive impairment in RA. METHODS: Multiple databases were searched for articles published between 1994 and 2016, to identify studies that have included: adults with RA; standardized neuropsychological tests; and sufficient information to ascertain the relationship between cognitive impairment and demographic, clinical, and psychological factors. Of 1,980 titles, 75 were retained at the abstract level, 36 at the full-text level, and 15 studies in the final review. These were evaluated using a modified Newcastle-Ottawa Scale, and the findings were synthesized using a narrative approach. RESULTS: Ten of 15 studies compared RA to other clinical groups and/or a control group. Based on summed effect size analyses, individuals with RA significantly underperformed on cognitive function tests compared to the control groups, particularly on verbal function, memory, and attention. Less clear differences were found between RA and other clinical groups. Some demographic (age and education), clinical (disease activity), and psychological (depression) factors were associated with cognitive impairment, but inconsistently so across studies. A number of limitations were identified: small and predominantly female samples, limited cognitive domain inclusion, lack of study details, and management of confounding variables. CONCLUSION: There is evidence of cognitive impairment in adults with RA. Further studies are needed to confirm prevalence rates and examine potential mechanisms.

Breast Cancer Patients' Perceptions of a Virtual Learning Environment for Pretreatment Education.

The process and technicalities of radiation therapy (RT) for cancer treatment can be challenging for patients to understand as RT involves complex procedures, highly specialised equipment, and radiation itself has limited sensory characteristics. Hence, it is imperative that education programs are specifically planned and developed to suit the needs of patients, address radiation as an entity and include salient visual aids. In this context, the Virtual Environment for Radiotherapy Training (VERT) system, primarily created for RT practitioner simulation, may provide unique opportunities for patient education. This article reports on patient feedback of a newly developed breast cancer patient education program, which integrates the VERT system as the focal education tool. The education program content included RT immobilisation, simulation, planning and treatment components, along with an introduction to the VERT system. Nineteen breast cancer patients (n = 19) completed an evaluation questionnaire at the completion of their VERT education program. Open-ended questions were used to detect the least and most useful aspects of the education session. Patient feedback indicated a high regard for the comprehensiveness of the education program, with particular acknowledgement of the three dimensional visual features of the VERT system. It is proposed that VERT's high visual impact should be exploited in tailored patient education programs in order to obtain maximum patient engagement and make significant gains in effective knowledge transfer.

The Impact of Clinical History on the Threshold Estimation of Auditory Brainstem Response Results for Infants.

Purpose: This study assesses the impact of patient clinical history on audiologists' performance when interpreting auditory brainstem response (ABR) results. Method: Fourteen audiologists' accuracy in estimating hearing threshold for 16 infants through interpretation of ABR traces was compared on 2 occasions at least 5 months apart. On the 1st occasion, ABR traces were presented to the audiologists with no clinical information except for the age of the child. On the 2nd occasion, audiologists were given a full clinical history for the ABR cases. Results: The addition of clinical history information had no statistically significant impact on sensitivity, specificity, or accuracy of diagnosis. Although the mean numbers of true-negative and true-positive diagnoses were higher when audiologists were given clinical information, the difference was again not statistically significant. Conclusion: This study suggests that if there are circumstances in which case material is incomplete or unavailable, audiologists have no cause for concern regarding the accuracy of their interpretation of ABR traces. In a clinical manner, this may help audiologists with large caseloads or audiologists who need to provide a diagnosis of hearing loss in a short time by allowing them to focus on conducting ABR without the need for case history information.

Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure.

It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity.