Opportunistic ship source level measurements in the Western Canadian Arctica).

Increased ship traffic due to climate change increases underwater noise in the Arctic. Therefore, accurate measurements of underwater radiated noise are necessary to map marine sound and quantify shipping's impact on the Arctic ecosystem. This paper presents a method to calculate opportunistic source levels (SLs) using passive acoustic data collected at six locations in the Western Canadian Arctic from 2018 to 2022.

The Arctic marine soundscape of the Amundsen Gulf, Western Canadian Arctic.

The underwater soundscape, a habitat component for Arctic marine mammals, is shifting. We examined the drivers of the underwater soundscape at three sites in the Amundsen Gulf, Northwest Territories, Canada from 2018 to 2019 and estimated the contribution of abiotic and biotic sources between 20 Hz and 24 kHz. Higher wind speeds and the presence of bearded seal (Erignathus barbatus) vocalizations led to increased SPL (0.

Boat noise impedes vocalizations of wild plainfin midshipman fish.

Marine noise is recognised as a growing threat that can induce maladaptive behavioural changes in many aquatic animals, including fishes. The plainfin midshipman is a soniferous fish with a prolonged breeding period, during which males produce tonal hums that attract females, and grunts and growls during agonistic interactions. In this study, we used acoustic recordings to assess the effects of boat noise on the presence, peak frequencies, and durations of plainfin midshipman calls in the wild.

No accumulation of microplastics detected in western Canadian ringed seals (Pusa hispida).

Ringed seals (Pusa hispida) play a crucial role in Arctic food webs as important pelagic predators and represent an essential component of Inuvialuit culture and food security. Plastic pollution is recognized as a global threat of concern, and Arctic regions may act as sinks for anthropogenic debris. To date, mixed evidence exists concerning the propensity for Canadian Arctic marine mammals to ingest and retain plastic.

Global COVID-19 lockdown highlights humans as both threats and custodians of the environment.

The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence.

Bowhead whales overwinter in the Amundsen Gulf and Eastern Beaufort Sea.

The bowhead whale is the only baleen whale endemic to the Arctic and is well adapted to this environment. Bowheads live near the polar ice edge for much of the year and although sea ice dynamics are not the only driver of their annual migratory movements, it likely plays a key role. Given the intrinsic variability of open water and ice, one might expect bowhead migratory plasticity to be high and linked to this proximate environmental factor.

Underwater sound levels in the Canadian Arctic, 2014-2019.

The Arctic has been a refuge from anthropogenic underwater noise; however, climate change has caused summer sea ice to diminish, allowing for unprecedented access and the potential for increased underwater noise. Baseline underwater sound levels must be quantified to monitor future changes and manage underwater noise in the Arctic. We analyzed 39 passive acoustic datasets collected throughout the Canadian Arctic from 2014 to 2019 using statistical models to examine spatial and temporal trends in daily mean sound pressure levels (SPL) and quantify environmental and anthropogenic drivers of SPL.

The sources and prevalence of anthropogenic noise in Rockfish Conservation Areas with implications for marine reserve planning.

Underwater noise pollution is a recognized threat to marine life. In British Columbia, Canada, Pacific rockfish (Sebastes spp.) were historically overfished, prompting the establishment of Rockfish Conservation Areas (RCAs).

Treatment of neurotrophic keratopathy with minimally invasive corneal neurotisation: long-term clinical outcomes and evidence of corneal reinnervation.

Aim: To report clinical outcomes and evidence of corneal innervation in patients with neurotrophic keratopathy (NK) treated with minimally invasive corneal neurotisation (MICN) using a sural nerve graft and donor sensory nerves from the face.

Methods: Patients undergoing MICN at The Hospital for Sick Children, Toronto, Canada were prospectively recruited. Data on central corneal sensation (CCS, measured with Cochet-Bonnet aesthesiometer), best-corrected visual acuity (BCVA) and corneal epithelial integrity were collected.

Assessing vessel slowdown for reducing auditory masking for marine mammals and fish of the western Canadian Arctic.

Vessel slowdown may be an alternative mitigation option in regions where re-routing shipping corridors to avoid important marine mammal habitat is not possible. We investigated the potential relief in masking in marine mammals and fish from a 10 knot speed reduction of container and cruise ships. The mitigation effect from slower vessels was not equal between ambient sound conditions, species or vessel-type.

A test of the thermal coadaptation hypothesis with ultimate measures of fitness in flour beetles.

Whole-organism performance of ectotherms depends on body temperature, which is tightly linked to environmental temperatures. Individuals attempting to optimize fitness must thus select appropriate temperatures. The thermal coadaptation hypothesis posits that T for traits closely linked to fitness should match temperatures selected by a species (T) and should coevolve with T.

Potential impacts of shipping noise on marine mammals in the western Canadian Arctic.

As the Arctic warms and sea ice decreases, increased shipping will lead to higher ambient noise levels in the Arctic Ocean. Arctic marine mammals are vulnerable to increased noise because they use sound to survive and likely evolved in a relatively quiet soundscape. We model vessel noise propagation in the proposed western Canadian Arctic shipping corridor in order to examine impacts on marine mammals and marine protected areas (MPAs).

Increased subcortical oligodendroglia-like cells in pharmacoresistant focal epilepsy in children correlate with extensive epileptogenic zones.

Objective: Cortical resections in epilepsy surgery tend to involve multiple lobes in children, compared to adults, partly due to underlying pathology. Oligodendroglia-like cells (OLCs) have been observed in surgical specimens from children with pharmacoresistant epilepsy. We hypothesize that OLCs recruit multiple-lobe epileptogenic zones in pediatric pharmacoresistant focal epilepsy.

Validation of the finding of hypertrophy of the clava in infantile neuroaxonal dystrophy/PLA2G6 by biometric analysis.

Introduction: Infantile neuroaxonal dystrophy (INAD), an autosomal recessive neurodegenerative disorder due to PLA2G6 mutation, is classified both as a PLA2G6-associated neurodegeneration (PLAN) disorder and as one of the neurodegeneration with brain iron accumulation (NBIA) disorders. Age of onset and clinical presentation in INAD is variable. Typically described imaging features of cerebellar atrophy, cerebellar cortex bright FLAIR signal, and globus pallidus iron deposition are variable or late findings.

Differential fitness in field and forest explains density-independent habitat selection by gartersnakes.

The ideal free distribution concept predicts that organisms will distribute themselves between habitats in a density-dependent manner so that individuals, on average, achieve the same fitness in each habitat. In ectotherms, environmental temperature has a strong impact on fitness, but temperature is not depletable and thus not density dependent. Can density-dependent habitat selection occur in ectotherms when habitats differ in thermal quality? We used an observational study of habitat selection by small snakes in field and forest, followed by manipulative habitat selection and fitness experiments with common gartersnakes in enclosures in field and forest to test this hypothesis.

Neuromuscular conditions associated with malignant hyperthermia in paediatric patients: A 25-year retrospective study.

Malignant Hyperthermia (MH) is a rare pharmacogenetic syndrome that can be fatal and the risk of MH in non RYR1-related disorders is unknown. We conducted a retrospective study to determine the prevalence of neuromuscular disorders among patients with MH at our centre. Patients who were admitted to the Hospital for Sick Children during the study period of January 1, 1990 to April 1, 2015 with a CK level > 8000 IU/L, or who received dantrolene, or who had a clinical diagnosis of MH were included.

A Novel Mutation in DMD (c.10797+5G>A) Causes Becker Muscular Dystrophy Associated with Intellectual Disability.

Background: Severe intellectual disability has been reported in a subgroup of patients with Duchenne muscular dystrophy but is not typically associated with Becker muscular dystrophy.

Patient: The authors report a 13-year-old boy, with severe intellectual disability (Wechsler Intelligence Scales for Children-IV, Full Scale IQ < 0.1 percentile), attention-deficit hyperactivity disorder, and mild muscle weakness.

A stringent test of the thermal coadaptation hypothesis in flour beetles.

Whole-organism performance depends on body temperature and ectotherms have variable body temperatures. The thermal coadaptation hypothesis posits that thermal reaction norms have coevolved with thermal preference such that organisms attain optimal performance under a narrow range of body temperatures commonly experienced in the wild. Since thermal reaction norms are often similar, researchers interested in the effects of temperature on fitness often use one easily measured thermal reaction norm, such as locomotor performance, and assume it is a good proxy for fitness when testing the thermal coadaptation hypothesis.

High temperature intensifies negative density dependence of fitness in red flour beetles.

Competition for food, space, or other depletable resources has strong impacts on the fitness of organisms and can lead to a pattern known as negative density dependence, where fitness decreases as population density increases. Yet, many resources that have strong impacts on fitness are nondepletable (e.g.

The degree of facial movement following microvascular muscle transfer in pediatric facial reanimation depends on donor motor nerve axonal density.

Background: Free functional muscle transfer to the face is a standard of facial animation. The contralateral facial nerve, via a cross-face nerve graft, provides spontaneous innervation for the transferred muscle, but is not universally available and has additional shortcomings. The motor nerve to the masseter provides an alternative innervation source.

Faecal corticosterone metabolite concentrations are not a good predictor of habitat suitability for common gartersnakes.

Measuring habitat suitability is important in conservation and in wildlife management. Measuring the abundance or presence-absence of a species in various habitats is not sufficient to measure habitat suitability because these metrics can be poor predictors of population success. Therefore, having some measure of population success is essential in assessing habitat suitability, but estimating population success is difficult.

Spinal clear cell meningioma in a 3-year-old: a case report.

Clear cell meningioma (CCM) is an aggressive meningioma variant with a tendency to early recurrence posing a challenge to its treatment. Although spinal meningiomas are uncommon in children, this rare entity has been described as the most common variant of spinal meningiomas in the pediatric age group. We present the case of a 3-year-old with a confirmed lumbar spine CCM and discuss the problems encountered in the management of this disease.

CNS-PNETs with C19MC amplification and/or LIN28 expression comprise a distinct histogenetic diagnostic and therapeutic entity.

Amplification of the C19MC oncogenic miRNA cluster and high LIN28 expression has been linked to a distinctly aggressive group of cerebral CNS-PNETs (group 1 CNS-PNETs) arising in young children. In this study, we sought to evaluate the diagnostic specificity of C19MC and LIN28, and the clinical and biological spectra of C19MC amplified and/or LIN28+ CNS-PNETs. We interrogated 450 pediatric brain tumors using FISH and IHC analyses and demonstrate that C19MC alteration is restricted to a sub-group of CNS-PNETs with high LIN28 expression; however, LIN28 immunopositivity was not exclusive to CNS-PNETs but was also detected in a proportion of other malignant pediatric brain tumors including rhabdoid brain tumors and malignant gliomas.