Publications by authors named "R Scott Heller"

1,262 Publications

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Origin and expansion of the world's most widespread pinniped: range-wide population genomics of the harbour seal (Phoca vitulina).

Mol Ecol 2022 Jan 23. Epub 2022 Jan 23.

Section for Evolutionary Genomics, Globe Institute, University of Copenhagen, Denmark.

The harbour seal (Phoca vitulina) is the most widely distributed pinniped, occupying a wide variety of habitats and climatic zones across the Northern Hemisphere. Intriguingly, the harbour seal is also one of the most philopatric seals, raising questions as to how it colonised virtually the whole of the Northern Hemisphere. To shed light on the origin, remarkable range expansion, population structure and genetic diversity of this species, we used genotyping-by-sequencing to analyse ~13,500 biallelic SNPs from 286 individuals sampled from 22 localities across the species' range. Our results point to a Northeast Pacific origin, colonisation of the North Atlantic via the Canadian Arctic, and subsequent stepping-stone range expansions across the North Atlantic from North America to Europe, accompanied by a successive loss of genetic diversity. Our analyses further revealed a deep divergence between modern North Pacific and North Atlantic harbour seals, with finer-scale genetic structure at regional and local scales consistent with strong philopatry. The study provides new insights into the harbour seal's remarkable ability to colonise and adapt to a wide range of habitats. Furthermore, it has implications for current harbour seal subspecies delineations and highlights the need for international and national red lists and management plans to ensure the protection of genetically and demographically isolated populations.
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http://dx.doi.org/10.1111/mec.16365DOI Listing
January 2022

Search for Long-Lived Particles Decaying in the CMS End Cap Muon Detectors in Proton-Proton Collisions at sqrt[s]=13  TeV.

Phys Rev Lett 2021 Dec;127(26):261804

Universiteit Antwerpen, Antwerpen, Belgium.

A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the end cap muon detectors. The search is sensitive to a broad range of LLP decay modes and to masses as low as a few GeV. No excess of events above the SM background is observed. The most stringent limits to date on the branching fraction of the Higgs boson to LLPs subsequently decaying to quarks and τ^{+}τ^{-} are found for proper decay lengths greater than 6, 20, and 40 m, for LLP masses of 7, 15, and 40 GeV, respectively.
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http://dx.doi.org/10.1103/PhysRevLett.127.261804DOI Listing
December 2021

A de novo ACTB gene pathogenic variant in identical twins with phenotypic variation for hydrops and jejunal atresia.

Am J Med Genet A 2021 Dec 31. Epub 2021 Dec 31.

Starship Child Health, Auckland City Hospital, Auckland, New Zealand.

The beta-actin gene (ACTB) encodes a ubiquitous cytoskeletal protein, essential for embryonic development in humans. De novo heterozygous missense variants in the ACTB are implicated in causing Baraitser-Winter cerebrofrontofacial syndrome (BWCFFS; MIM#243310). ACTB pathogenic variants are rarely associated with intestinal malformations. We report on a rare case of monozygotic twins presenting with proximal small bowel atresia and hydrops in one, and apple-peel bowel atresia and laryngeal dysgenesis in the other. The twin with hydrops could not be resuscitated. Intensive and surgical care was provided to the surviving twin. Rapid trio genome sequencing identified a de novo missense variant in ACTB (NM_00101.3:c.1043C>T; p.(Ser348Leu)) that guided the care plan. The identical variant subsequently was identified in the demised twin. To characterize the functional effect, the variant was recreated as a pseudoheterozygote in a haploid wild-type S. cerevisiae strain. There was an obvious growth defect of the yACT1 pseudoheterozygote compared to a yACT1 strain when grown at 22°C but not when grown at 30°C, consistent with the yACT1 S348L variant having a functional defect that is dominant over the wild-type allele. The functional results provide supporting evidence that the Ser348Leu variant is likely to be a pathogenic variant, including being associated with intestinal malformations in BWCFFS, and can demonstrate variable expressivity within monozygotic twins.
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http://dx.doi.org/10.1002/ajmg.a.62631DOI Listing
December 2021

Pursuing More Aggressive Timelines in the Surgical Treatment of Traumatic Spinal Cord Injury (TSCI): A Retrospective Cohort Study with Subgroup Analysis.

J Clin Med 2021 Dec 20;10(24). Epub 2021 Dec 20.

Department of Paraplegiology, BG Trauma Centre Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen, Germany.

Background: The optimal timing of surgical therapy for traumatic spinal cord injury (TSCI) remains unclear. The purpose of this study is to evaluate the impact of "ultra-early" (<4 h) versus "early" (4-24 h) time from injury to surgery in terms of the likelihood of neurologic recovery.

Methods: The effect of surgery on neurological recovery was investigated by comparing the assessed initial and final values of the American Spinal Injury Association (ASIA) Impairment Scale (AIS). A post hoc analysis was performed to gain insight into different subgroup regeneration behaviors concerning neurological injury levels.

Results: Datasets from 69 cases with traumatic spinal cord injury were analyzed. Overall, 19/46 (41.3%) patients of the "ultra-early" cohort saw neurological recovery compared to 5/23 (21.7%) patients from the "early" cohort ( = 0.112). The subgroup analysis revealed differences based on the neurological level of injury (NLI) of a patient. An optimal cutpoint for patients with a cervical lesion was estimated at 234 min. Regarding the prediction of neurological improvement, sensitivity was 90.9% with a specificity of 68.4%, resulting in an AUC (area under the curve) of 84.2%. In thoracically and lumbar injured cases, the estimate was lower, ranging from 284 (thoracic) to 245 min (lumbar) with an AUC of 51.6% and 54.3%.

Conclusions: Treatment within 24 h after TSCI is associated with neurological recovery. Our hypothesis that intervention within 4 h is related to an improvement in the neurological outcome was not confirmed in our collective. In a clinical context, this suggests that after TSCI there is a time frame to get the right patient to the right hospital according to advanced trauma life support (ATLS) guidelines.
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http://dx.doi.org/10.3390/jcm10245977DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8703655PMC
December 2021

Spontaneous resolution of cerebral arteriovenous malformation after liver transplant: illustrative case.

Br J Neurosurg 2021 Dec 21:1-4. Epub 2021 Dec 21.

Department of Neurosurgery and Brain Repair, University of South Florida, Tampa, FL, USA.

Background: Cerebral arteriovenous malformations (AVMs) have historically been considered congenital lesions with treatment options including surgery, radiation therapy, and observation. Spontaneous resolution of cerebral AVMs remains an exceedingly rare event with poorly understood pathophysiology.

Materials And Methods: Herein we report a retrospective case review of a 28-year-old man with alcoholic cirrhosis who presented with a seizure 3 weeks after liver transplantation. Neuroimaging confirmed the presence of a Spetzler-Martin grade 2 AVM in the right frontal lobe. Due to the recent liver transplantation, treatment was deferred at the time of initial diagnosis and the patient was observed for a course of 1 year. Follow-up imaging 1 year later showed resolution of the AVM, confirmed by a catheter angiogram.

Conclusion: Spontaneous resolution of cerebral AVMs is a rare event. Treatment of chronic liver disease resulted in the normalization of angiogenic factors that likely led to AVM resolution. This case provides valuable insight into the vital role of angiogenesis in the natural history of AVMs.
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http://dx.doi.org/10.1080/02688697.2021.2016621DOI Listing
December 2021
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