An Overview of the Karst Areas in British Columbia, Canada

Karst is a three-dimensional landscape that occurs in soluble bedrock (typically limestone, marble, dolostone, gypsum or halite) and is defined by a solutionally weathered surface, a subsurface drainage system (where conduit-flow dominates), and underground openings and caves. Karst can host unique flora and subsurface fauna, as well as a wide range of other scientific, recreational and cultural values. Karst and potential karst areas underlie approximately 10% of British Columbia (BC), but the distribution and extent of this landscape has yet to be fully explored and delineated. Some of the most extensive and well-developed karst areas occur within the forestedlimestone areas of coastal BC, such as on Vancouver Island and Haida Gwaii, where numerous surface karst features and caves are known. Karst in the interior plateau regions of British Columbia is less well known, being in part covered by thick deposits of glacial materials. Alpine karst regions are most apparent in the Rocky Mountains where there are limestone plateaus, karst drainages and cave systems that have close connections to past and present glacial systems. Mapping of karst is a critical component for any land-use or resource development activity in all regions of British Columbia, as the environmental impacts on karst and its associated values are potentially significant. The regional distribution of karst in BC is not well mapped, with only an office-based reconnaissance karst potential map (1:250,000-scale) and a related database completed in 1999. A renewed effort should now be made to better map karst across British Columbia using digital bedrock mapping data released in 2017, combined with more recent satellite imagery and improved field knowledge.RÉSUMÉLe karst est un paysage tridimensionnel qui se présente dans le substrat rocheux soluble (généralement calcaire, marbre, dolomite, gypse ou halite) et est défini par une surface altérée par dissolution, un système de drainage souterrain (où l’écoulement par conduit domine) et des ouvertures et cavernes souterraines. Le karst peut abriter une flore et une faune souterraine unique, ainsi qu’une grande variété d’autres ressources scientifiques, de loisir et culturelles. Les zones karstiques et potentiellement karstiques constituent environ 10% de la surface de la Colombie-Britannique, mais la répartition et l’étendue de ce paysage n’a pas été complètement explorées et circonscrites. Certaines des zones karstiques les plus étendues et les mieux développées se trouvent dans les calcaires des zones calcaires boisées de la côte de la Colombie-Britannique, telles que l’île de Vancouver et l’archipel de Haida Gwaii, où l’on connaît de nombreuses caractéristiques karstiques de surface et des cavernes. Le karst des régions des plateaux intérieurs de la Colombie-Britannique est moins bien connu, étant en partie recouvert d’épais dépôts de matériaux glaciaires. Les régions karstiques alpines sont plus apparentes dans les montagnes Rocheuses où se trouvent des plateaux calcaires, des bassins de drainage karstiques et des systèmes de cavernes étroitement liés aux systèmes glaciaires passés et contemporains. La cartographie du karst est une constituante essentielle de toute activité d’utilisation du terrain ou de développement des ressources dans toutes les régions de la Colombie-Britannique, car les impacts environnementaux sur le karst et ses bénéfices associés sont potentiellement importants. La distribution régionale et les caractéristiques des karsts en Colombie-Britannique ne sont pas bien cartographiées, avec seulement une carte de reconnaissance du potentiel karstique établie par une étude de bureau (à l’échelle de 1/250 000) et une base de données associée, complétées en 1999. Il faut aujourd’hui améliorer la cartographie de karsts en Colombie-Britannique en utilisant les données numériques de cartographie du substrat rocheux publiées en 2017, combinées avec des images satellite plus récentes et à une meilleure connaissance du terrain

Multi-rotor unmanned aerial vehicles (UVAs) and high-resolution compact digital cameras: a promising new method for monitoring changes to surface karst resources

In the course of doctoral research, the authors required a quick and accurate means of documenting the real-time state of surface karst features at a variety of scales in remote and challenging field conditions. The main difficulty was finding an aerial platform that was 1) consistently effective; 2) versatile; and 3) relatively inexpensive. High resolution vertical images obtained during recreational use of a small multi-rotor unmanned aerial vehicle (UAV) seemed to have the potential to answer this need. Using five case studies, the authors examine the potential of these images for mapping, documenting, and monitoring changes to surface karst resources following forestry-related activities in the coastal temperate rainforest of British Columbia (B.C.). Possible applications, strengths and limitations of this technology are discussed. The authors conclude that mini quadcopter UAVs equipped with high-resolution compact digital cameras are a promising and cost-effective new tool for karst scientists and karst managers

Surface polaritons on left-handed cylinders: A complex angular momentum analysis

We consider the scattering of electromagnetic waves by a left-handed cylinder -- i.e., by a cylinder fabricated from a left-handed material -- in the framework of complex angular momentum techniques. We discuss both the TE and TM theories. We emphasize more particularly the resonant aspects of the problem linked to the existence of surface polaritons. We prove that the long-lived resonant modes can be classified into distinct families, each family being generated by one surface polariton propagating close to the cylinder surface and we physically describe all the surface polaritons by providing, for each one, its dispersion relation and its damping. This can be realized by noting that each surface polariton corresponds to a particular Regge pole of the $S$ matrix of the cylinder. Moreover, for both polarizations, we find that there exists a particular surface polariton which corresponds, in the large-radius limit, to the surface polariton which is supported by the plane interface. There exists also an infinite family of surface polaritons of whispering-gallery type which have no analogs in the plane interface case and which are specific to left-handed materials.Comment: published version. v3: reference list correcte

Relativistic Viscous Fluid Dynamics and Non-Equilibrium Entropy

Fluid dynamics corresponds to the dynamics of a substance in the long wavelength limit. Writing down all terms in a gradient (long wavelength) expansion up to second order for a relativistic system at vanishing charge density, one obtains the most general (causal) equations of motion for a fluid in the presence of shear and bulk viscosity, as well as the structure of the non-equilibrium entropy current. Requiring positivity of the divergence of the non-equilibrium entropy current relates some of its coefficients to those entering the equations of motion. I comment on possible applications of these results for conformal and non-conformal fluids.Comment: 25 pages, no figures; v2: matches published versio

Executive Functions and Prefrontal Cortex: A Matter of Persistence?

Executive function is thought to originates from the dynamics of frontal cortical networks. We examined the dynamic properties of the blood oxygen level dependent time-series measured with functional MRI (fMRI) within the prefrontal cortex (PFC) to test the hypothesis that temporally persistent neural activity underlies performance in three tasks of executive function. A numerical estimate of signal persistence, the Hurst exponent, postulated to represent the coherent firing of cortical networks, was determined and correlated with task performance. Increasing persistence in the lateral PFC was shown to correlate with improved performance during an n-back task. Conversely, we observed a correlation between persistence and increasing commission error – indicating a failure to inhibit a prepotent response – during a Go/No-Go task. We propose that persistence within the PFC reflects dynamic network formation and these findings underline the importance of frequency analysis of fMRI time-series in the study of executive functions

Exploiting macrophage autophagy-lysosomal biogenesis as a therapy for atherosclerosis

Macrophages specialize in removing lipids and debris present in the atherosclerotic plaque. However, plaque progression renders macrophages unable to degrade exogenous atherogenic material and endogenous cargo including dysfunctional proteins and organelles. Here we show that a decline in the autophagy-lysosome system contributes to this as evidenced by a derangement in key autophagy markers in both mouse and human atherosclerotic plaques. By augmenting macrophage TFEB, the master transcriptional regulator of autophagy-lysosomal biogenesis, we can reverse the autophagy dysfunction of plaques, enhance aggrephagy of p62-enriched protein aggregates and blunt macrophage apoptosis and pro-inflammatory IL-1β levels, leading to reduced atherosclerosis. In order to harness this degradative response therapeutically, we also describe a natural sugar called trehalose as an inducer of macrophage autophagy-lysosomal biogenesis and show trehalose's ability to recapitulate the atheroprotective properties of macrophage TFEB overexpression. Our data support this practical method of enhancing the degradative capacity of macrophages as a therapy for atherosclerotic vascular disease

Non-maximally entangled states: production, characterization and utilization

Using a spontaneous-downconversion photon source, we produce true non-maximally entangled states, i.e., without the need for post-selection. The degree and phase of entanglement are readily tunable, and are characterized both by a standard analysis using coincidence minima, and by quantum state tomography of the two-photon state. Using the latter, we experimentally reconstruct the reduced density matrix for the polarization. Finally, we use these states to measure the Hardy fraction, obtaining a result that is $122 \sigma$ from any local-realistic result.Comment: 4 pages, 4 figures. To appear in Phys. Rev. Let

Cumulative impact assessments of multiple host species loss from plant diseases show disproportionate reductions in associated biodiversity

Non-native plant pests and pathogens are increasing exponentially, causing extirpation of foundation species. The impact of large-scale declines in a single host on associated biodiversity is widely documented. However, the impact of multiple host loss on biodiversity and whether these impacts are multiplicative has not been assessed. Ecological theory suggests that systems with greater functional redundancy (alternative hosts) will be more resilient to the loss of sympatric hosts. We test this theory and show its importance in relation to pest/pathogen impact assessments. We assessed the potential impact on biodiversity of the loss of two widely occurring sympatric European tree species, Fraxinus excelsior and Quercus petraea/robur, both of which are currently threatened by a range of pests and pathogens. At the UK scale, the total number of associated species at risk of extirpation from plant diseases affecting these two sympatric hosts is greater than the sum of the associated species at risk from declines in either host alone. F. excelsior hosts 45 obligate species (species only found on that host) and Q. petraea/robur hosts 326. However, a decline in both these trees would impact 512 associated species, across multiple taxon groups, a 38% increase. Assessments at a local scale, 24 mixed F. excelsior–Q. petraea/robur woodlands revealed that these impacts may be even greater due to a lack of functional redundancy. Only 21% of sites were able to provide functional redundancy for F. excelsior and Q. petraea/robur associated species which can use other tree species. In most woodlands, the tree species required to provide functional redundancy were not present, although the site conditions were often suitable for them to grow. Synthesis. Understanding of functional redundancy should be applied to assessments of pests/pathogens impact on biodiversity. In risk assessments, higher impact scores should be given to pests/pathogens affecting hosts occurring with other host plant species already impacted by pests/pathogens. Current pest/pathogen risk assessment approaches that ignore the cumulative, cascading effects shown in this study may allow an insidious, mostly overlooked, driver of biodiversity loss to continue.Biotechnology and Biological Sciences Research Council, Grant/Award Number: BB/N022831/1; Rural and Environment Science and Analytical Services Division.info:eu-repo/semantics/publishedVersio

Cumulative impact assessments of multiple host species loss from plant diseases show disproportionate reductions in associated biodiversity

Funding Information: This work was funded by BBSRC grant Protecting Oak Ecosystems (PuRpOsE): BB/N022831/1 with additional funding from the Scottish Government's Rural and Environment Research and Analysis Directorate 2016–2021 strategic research programme. The authors thank Nick Hodgetts for collating the lists of the bryophyte species associated with ash and oak, Ralph Harmer for conducting some of the site visits and the site owners for allowing us access to the sites. Katharine Preedy provided statistical advice. Steve Albon and Robin Pakeman kindly provided comments to improve earlier drafts.Peer reviewe

Study protocol for a randomised placebo-controlled trial of pramipexole in addition to mood stabilisers for patients with treatment resistant bipolar depression (the PAX-BD study)

Abstract Background Treatment Resistant Bipolar Depression (TRBD) is a major contributor to the burden of disease associated with Bipolar Disorder (BD). Treatment options for people experiencing bipolar depression are limited to three interventions listed by National Institute for Health and Care: lamotrigine, quetiapine and olanzapine, of which the latter two are often not well tolerated. The majority of depressed people with BD are therefore prescribed antidepressants despite limited efficacy. This demonstrates an unmet need for additional interventions. Pramipexole has been shown to improve mood symptoms in animal models of depression, in people with Parkinson’s Disease and two proof of principle trials of pramipexole for people with BD who are currently depressed. Methods The PAX-BD study, funded by the United Kingdom (UK) National Institute for Health Research, aims to extend previous findings by assessing the efficacy, safety and health economic impact of pramipexole in addition to mood stabilisers for patients with TRBD. A randomised, double-blind, placebo controlled design is conducted in a naturalistic UK National Health Service setting. An internal pilot study to examine feasibility and acceptability of the study design is included. Participants with TRBD are screened from National Health Service secondary care services in up to 40 mental health trusts in the UK, with the aim of recruiting approximately 414 participants into a pre-randomisation phase to achieve a target of 290 randomised participants. Primary safety and efficacy measures are at 12 weeks following randomisation, with follow up of participants to 52 weeks. The primary outcome is depressive symptoms as measured by Quick Inventory for Depressive Symptomatology – Self Report. Secondary outcomes include changes in anxiety, manic symptoms, tolerability, acceptability, quality of life and cost-effectiveness. Outcome measures are collected remotely using self-report tools implemented online, and observer-rated assessments conducted via telephone. ANCOVA will be used to examine the difference in rating scale scores between treatment arms, and dependent on compliance in completion of weekly self-report measures. A mixed effects linear regression model may also be used to account for repeated measures. Trial registration ISRCTN72151939. Registered on 28 August 2019, http://www.isrctn.com/ISRCTN72151939 Protocol Version: 04-FEB-2021, Version 9.0