Abstract
Nitrogen (N) footprints are one method to quantify consumer driven reactive nitrogen (Nr) emissions. Canada is a highly urbanized yet economically natural resource-dependent country, ...providing an illustrative case study to examine attribution of Nr emissions to per capita consumption, either domestically or abroad. Yet, considered only at the national scale, N footprints may obscure absolute and relative contributions of local drivers to Nr emissions. We apply a top-down N footprint approach drawing from national N budgets, emissions inventories, and agricultural statistics to estimate sub-national (provincial) drivers of Nr emissions across Canada. We calculate per capita provincial Nr footprints from four primary sectors in 2018: (a) crop production, (b) animal production, (c) wastewater treatment, and (d) fossil fuel burning. We estimate that Canada’s total N footprint is 995.7 Gg Nr yr
−1
, which equates to an average per capita footprint nationally of 27.1 kg Nr capita
−1
yr
−1
. The largest national contributions come from a few key (sub)sectors, including transport, beef consumption, and wastewater treatment. Provincial per capita N footprints vary widely, with the largest (Saskatchewan 50.3 kg Nr cap
−1
yr
−1
) more than double the smallest (Ontario 22.0 kg Nr cap
−1
yr
−1
). Most variation across provinces is due to the fossil fuels sector, including emissions from energy generation and the oil and gas industry. We therefore compare our top-down approach for the fossil fuels sector with bottom-up N footprints and territorial emissions methodologies. Per capita N emissions vary considerably across these approaches. For example, Alberta’s per-capita fossil fuel Nr emissions are 45.9, 23.0, and 6.3 kg Nr cap
−1
yr
−1
using territorial, top-down and bottom-up footprint approaches, respectively. This analysis demonstrates the challenges of attributing Nr emission for export-oriented economies. Our study provides novel insights on sub-national drivers of Nr emissions, emphasizing the need to consider how heterogeneous geographic contexts contribute to national N footprints.
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•Cellular and psychological stress elevate nuclear REST in stress-responsive neurons.•REST epigenetically determines target gene expression following stress.•REST protects neurons ...from oxidative stress and hyperexcitability.•REST inhibits premature neural stem cell depletion and amyloid-β1-42 pathology.•Modulation of REST activity is a promising strategy to promote stress resilience.
The transcriptional repressor REST (Repressor Element-1 Silencing Transcription factor) is a key modulator of the neuronal epigenome and targets genes involved in neuronal differentiation, axonal growth, vesicular transport, ion channel conductance and synaptic plasticity. Whilst its gene expression-modifying properties have been examined extensively in neuronal development, REST’s response towards stress-induced neuronal insults has only recently been explored. Overall, REST appears to be an ideal candidate to fine-tune neuronal gene expression following different forms of cellular, neuropathological, psychological and physical stressors. Upregulation of REST is reportedly protective against premature neural stem cell depletion, neuronal hyperexcitability, oxidative stress, neuroendocrine system dysfunction and neuropathology. In contrast, neuronal REST activation has also been linked to neuronal dysfunction and neurodegeneration. Here, we highlight key findings and discrepancies surrounding our current understanding of REST’s function in neuronal adaptation to stress and explore its potential role in neuronal stress resilience in the young and ageing brain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The unexpected victories of Donald Trump in the United States 2016 Presidential campaign and of the Leave campaign in the British referendum on membership in the European Union have important ...similarities in terms of campaign strategy, rhetoric and social bases of support. They are exemplars of a wave of right-wing populism that has swept across advanced democracies. The triumph of Brexit also raises questions about the future relationship between the United Kingdom and United States. While it is too early to be certain about either the impact of Brexit or the future direction of the Trump Administration, and despite ties between the Trump Administration and British politicians who campaigned for or subsequently supported Brexit, the United Kingdom could become much less useful as a diplomatic and economic partner to the United States after leaving the European Union.
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DOBA, IZUM, KILJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Neurons and glial cells of the central nervous system (CNS) release extracellular vesicles (EVs) to the interstitial fluid of the brain and spinal cord parenchyma. EVs contain proteins, nucleic acids ...and lipids that can be taken up by, and modulate the behaviour of, neighbouring recipient cells. The functions of EVs have been extensively studied in the context of neurodegenerative diseases. However, mechanisms involved in EV‐mediated neuron–glial communication under physiological conditions or healthy ageing remain unclear. A better understanding of the myriad roles of EVs in CNS homeostasis is essential for the development of novel therapeutics to alleviate and reverse neurological disturbances of ageing. Proteomic studies are beginning to reveal cell type‐specific EV cargo signatures that may one day allow us to target specific neuronal or glial cell populations in the treatment of debilitating neurological disorders. This review aims to synthesise the current literature regarding EV‐mediated cell–cell communication in the brain, predominantly under physiological conditions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
How might academic practices contribute to the exciting proliferation of economic experiments occurring worldwide in the current moment? In this paper we describe the work of a nascent research ...community of economic geographers and other scholars who are making the choice to bring marginalized, hidden and alternative economic activities to light in order to make them more real and more credible as objects of policy and activism. The diverse economies research program is, we argue, a performative ontological project that builds upon and draws forth a different kind of academic practice and subjectivity. Using contemporary examples, we illustrate the thinking practices of ontological reframing, re-reading for difference and cultivating creativity and we sketch out some of the productive lines of inquiry that emerge from an experimental, performative and ethical orientation to the world. The paper is accompanied by an electronic bibliography of diverse economies research with over 200 entries.
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CEKLJ, DOBA, IZUM, KILJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The step‐change in gravimetric energy density needed for electrochemical energy storage devices to power unmanned autonomous vehicles, electric vehicles, and enable low‐cost clean grid storage is ...unlikely to be provided by conventional lithium ion batteries. Lithium–sulfur batteries comprising lightweight elements provide a promising alternative, but the associated polysulfide shuttle in typical ether‐based electrolytes generates loss in capacity and low coulombic efficiency. The first new electrolyte based on a unique combination of a relatively hydrophobic sulfonamide solvent and a low ion‐pairing salt, which inhibits the polysulfide shuttle, is presented. This system behaves as a sparingly solvating electrolyte at slightly elevated temperatures, where it sustains reversible capacities as high as 1200–1500 mAh g−1 over a wide range of current density (2C–C/5, respectively) when paired with a lithium metal anode, with a coulombic efficiency of >99.7 % in the absence of LiNO3 additive.
The detrimental polysulfide shuttle associated with Li‐S batteries is alleviated (without the addition of LiNO3) through the combined use of a non‐polar sulfonamide solvent and low‐ion‐pairing salt as the electrolyte. This combination transforms to a sparingly solvating electrolyte at 50 °C and sustains close to theoretical capacity at rates of C/5 with a coulombic efficiency of 99.7 %.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To determine which strength training exercises selectively activate the biceps femoris long head (BF
) muscle.
We recruited 24 recreationally active men for this two-part observational study
Part 1: ...We explored the amplitudes and the ratios of lateral (BF) to medial hamstring (MH) normalised electromyography (nEMG) during the concentric and eccentric phases of 10 common strength training exercises. Part 2: We used functional MRI (fMRI) to determine the spatial patterns of hamstring activation during two exercises which (1) most selectively and (2) least selectively activated the BF in part 1.
Eccentrically, the largest BF/MH nEMG ratio occurred in the 45° hip-extension exercise; the lowest was in the Nordic hamstring (Nordic) and bent-knee bridge exercises. Concentrically, the highest BF/MH nEMG ratio occurred during the lunge and 45° hip extension; the lowest was during the leg curl and bent-knee bridge. fMRI revealed a greater BF
to semitendinosus activation ratio in the 45° hip extension than the Nordic (p<0.001). The T2 increase after hip extension for BF
, semitendinosus and semimembranosus muscles was greater than that for BF
(p<0.001). During the Nordic, the T2 increase was greater for the semitendinosus than for the other hamstring muscles (p≤0.002).
We highlight the heterogeneity of hamstring activation patterns in different tasks. Hip-extension exercise selectively activates the long hamstrings, and the Nordic exercise preferentially recruits the semitendinosus. These findings have implications for strategies to prevent hamstring injury as well as potentially for clinicians targeting specific hamstring components for treatment (mechanotherapy).
The ability to intercept uncooperative targets is key to many diverse flight behaviors, from courtship to predation. Previous research has looked for simple geometric rules describing the attack ...trajectories of animals, but the underlying feedback laws have remained obscure. Here, we use GPS loggers and onboard video cameras to study peregrine falcons, Falco peregrinus, attacking stationary targets, maneuvering targets, and live prey. We show that the terminal attack trajectories of peregrines are not described by any simple geometric rule as previously claimed, and instead use system identification techniques to fit a phenomenological model of the dynamical system generating the observed trajectories. We find that these trajectories are best—and exceedingly well—modeled by the proportional navigation (PN) guidance law used by most guided missiles. Under this guidance law, turning is commanded at a rate proportional to the angular rate of the line-of-sight between the attacker and its target, with a constant of proportionality (i.e., feedback gain) called the navigation constant (N). Whereas most guided missiles use navigation constants falling on the interval 3 ≤ N ≤ 5, peregrine attack trajectories are best fitted by lower navigation constants (median N < 3). This lower feedback gain is appropriate at the lower flight speed of a biological system, given its presumably higher error and longer delay. This same guidance law could find use in small visually guided drones designed to remove other drones from protected airspace.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Phenylallenes undergo fluorinative rearrangement upon the action of (difluoroiodo)toluene in the presence of 20 mol % BF3⋅OEt2 to yield α‐difluoromethyl styrenes. This unprecedented reaction was ...entirely chemoselective for the internal allene π bond, and showed remarkable regioselectivity during the fluorination event. Substituted phenylallenes, phenylallenes possessing both phenyl‐ and α‐allenyl substituents, and diphenylallenes were investigated, and good functional‐group compatibility was observed throughout. The ease with which allenes can be prepared on a large scale, and the operational simplicity of this reaction allowed us to rapidly access fluorine‐containing building blocks that have not been accessed by conventional deoxyfluorination strategies.
A real gem: Reacting substituted phenylallenes with TolIF2 enables the regio‐ and chemoselective synthesis of α‐difluoromethyl styrenes. Fluorination of the internal olefin is interrupted by a 1,2‐phenyl shift, thus leading to geminal instead of vicinal difluorides.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Environmental occurrence and biomonitoring data for per- and polyfluoroalkyl substances (PFAS) demonstrate that humans are exposed to mixtures of PFAS. This article presents a new and ...systematic analysis of available PFAS toxicity study data using a tiered mixtures risk assessment framework consistent with United States and international mixtures guidance. The lines of evidence presented herein include a critique of whole mixture toxicity studies and analysis of dose-response models based on data from subchronic oral toxicity studies in rats. Based on available data to-date, concentration addition and relative potency factor methods are found to be inappropriate due to differences among sensitive effects and target organ potencies and noncongruent dose-response curves for the same effect endpoints from studies using the same species and protocols. Perfluorooctanoic acid and perfluorooctane sulfonic acid lack a single mode of action or molecular initiating event and our evaluation herein shows they also have noncongruent dose-response curves. Dose-response curves for long-chain perfluoroalkyl sulfonic acids (PFSAs) also significantly differ in shapes of the curves from short-chain PFSAs and perfluoroalkyl carboxylic acids evaluated, and additional differences are apparent when curves are evaluated based on internal or administered dose. Following well-established guidance, the hazard index method applied to perfluoroalkyl carboxylic acids and PFSAs grouped separately is the most appropriate approach for conducting a screening level risk assessment for nonpolymeric PFAS mixtures, given the current state-of-the science. A clear presentation of assumptions, uncertainties, and data gaps is needed before dose-additivity methods, including hazard index , are used to support risk management decisions. Adverse outcome pathway(s) and mode(s) of action information for perfluorooctanoic acid and perfluorooctane sulfonic acid and for other nonpolymer PFAS are key data gaps precluding more robust mixtures methods. These findings can guide the prioritization of future studies on single chemical and whole mixture toxicity studies.
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