xi

Axially symmetric solutions of the Allen-Cahn equation with finite Morse index

Changfeng Gui, Kelei Wang and Jucheng Wei
Trans. Amer. Math. Soc. 373 (2020), 3649-3668.
Abstract, references and article information




xi

Equidistribution on homogeneous spaces and the distribution of approximates in Diophantine approximation

Mahbub Alam and Anish Ghosh
Trans. Amer. Math. Soc. 373 (2020), 3357-3374.
Abstract, references and article information





xi

Nonlinear ????-term approximation of harmonic functions from shifts of the Newtonian kernel

Kamen G. Ivanov and Pencho Petrushev
Trans. Amer. Math. Soc. 373 (2020), 3117-3176.
Abstract, references and article information




xi

On the computational complexity of algebraic numbers: the Hartmanis–Stearns problem revisited

Boris Adamczewski, Julien Cassaigne and Marion Le Gonidec
Trans. Amer. Math. Soc. 373 (2020), 3085-3115.
Abstract, references and article information




xi

On the dimension of subspaces of continuous functions attaining their maximum finitely many times

L. Bernal-González, H. J. Cabana-Méndez, G. A. Muñoz-Fernández and J. B. Seoane-Sepúlveda
Trans. Amer. Math. Soc. 373 (2020), 3063-3083.
Abstract, references and article information




xi

Approximation of solutions of the wave equation driven by a stochastic measure

V. M. Radchenko and N. O. Stefans’ka
Theor. Probability and Math. Statist. 99 (2020), 229-238.
Abstract, references and article information




xi

Calculation of the convexity adjustment to the forward rate in the Vasicek model for the forward in-arrears contracts on LIBOR rate

N. O. Malykh and I. S. Postevoy
Theor. Probability and Math. Statist. 99 (2020), 189-198.
Abstract, references and article information




xi

Asymptotic distribution of the maximum likelihood estimator in the fractional Vašíček model

S. S. Lohvinenko and K. V. Ralchenko
Theor. Probability and Math. Statist. 99 (2020), 149-168.
Abstract, references and article information




xi

Modified Euler scheme for the weak approximation of stochastic differential equations driven by the Wiener process

S. V. Bodnarchuk and O. M. Kulyk
Theor. Probability and Math. Statist. 99 (2020), 53-65.
Abstract, references and article information





xi

Classical solution of a PDE system stemming from auxin transport model for leaf venation

Bin Li and Jieqiong Shen
Proc. Amer. Math. Soc. 148 (2020), 2565-2578.
Abstract, references and article information




xi

A topology on the set of isomorphism classes of maximal Cohen–Macaulay modules

Naoya Hiramatsu and Ryo Takahashi
Proc. Amer. Math. Soc. 148 (2020), 2359-2369.
Abstract, references and article information




xi

Metric Spaces, Convexity and Nonpositive Curvature: Second Edition

Athanase Papadopoulos, Universite de Strasbourg - A publication of the European Mathematical Society, 2013, 320 pp., Softcover, ISBN-13: 978-3-03719-132-3, List: US$58, All AMS Members: US$46.40, EMSILMTP/6.R

This book is about metric spaces of nonpositive curvature in the sense of Busemann, that is, metric spaces whose distance function satisfies a...




xi

Filtering out toxic chromium from water

(Ecole Polytechnique Fédérale de Lausanne) EPFL chemists have developed sponges to capture various target substances, like gold, mercury and lead, dissolved in solution. The sponges are actually porous crystals called metal organic frameworks, and now one exists for capturing toxic hexavalent chromium from water.




xi

Evolution, expression, and substrate specificities of aldehyde oxidase enzymes in eukaryotes [Enzymology]

Aldehyde oxidases (AOXs) are a small group of enzymes belonging to the larger family of molybdo-flavoenzymes, along with the well-characterized xanthine oxidoreductase. The two major types of reactions that are catalyzed by AOXs are the hydroxylation of heterocycles and the oxidation of aldehydes to their corresponding carboxylic acids. Different animal species have different complements of AOX genes. The two extremes are represented in humans and rodents; whereas the human genome contains a single active gene (AOX1), those of rodents, such as mice, are endowed with four genes (Aox1-4), clustering on the same chromosome, each encoding a functionally distinct AOX enzyme. It still remains enigmatic why some species have numerous AOX enzymes, whereas others harbor only one functional enzyme. At present, little is known about the physiological relevance of AOX enzymes in humans and their additional forms in other mammals. These enzymes are expressed in the liver and play an important role in the metabolisms of drugs and other xenobiotics. In this review, we discuss the expression, tissue-specific roles, and substrate specificities of the different mammalian AOX enzymes and highlight insights into their physiological roles.




xi

A peroxisome deficiency-induced reductive cytosol state up-regulates the brain-derived neurotrophic factor pathway [Metabolism]

The peroxisome is a subcellular organelle that functions in essential metabolic pathways, including biosynthesis of plasmalogens, fatty acid β-oxidation of very-long-chain fatty acids, and degradation of hydrogen peroxide. Peroxisome biogenesis disorders (PBDs) manifest as severe dysfunction in multiple organs, including the central nervous system (CNS), but the pathogenic mechanisms in PBDs are largely unknown. Because CNS integrity is coordinately established and maintained by neural cell interactions, we here investigated whether cell-cell communication is impaired and responsible for the neurological defects associated with PBDs. Results from a noncontact co-culture system consisting of primary hippocampal neurons with glial cells revealed that a peroxisome-deficient astrocytic cell line secretes increased levels of brain-derived neurotrophic factor (BDNF), resulting in axonal branching of the neurons. Of note, the BDNF expression in astrocytes was not affected by defects in plasmalogen biosynthesis and peroxisomal fatty acid β-oxidation in the astrocytes. Instead, we found that cytosolic reductive states caused by a mislocalized catalase in the peroxisome-deficient cells induce the elevation in BDNF secretion. Our results suggest that peroxisome deficiency dysregulates neuronal axogenesis by causing a cytosolic reductive state in astrocytes. We conclude that astrocytic peroxisomes regulate BDNF expression and thereby support neuronal integrity and function.




xi

12-LOX catalyzes the oxidation of 2-arachidonoyl-lysolipids in platelets generating eicosanoid-lysolipids that are attenuated by iPLA2{gamma} knockout [Signal Transduction]

The canonical pathway of eicosanoid production in most mammalian cells is initiated by phospholipase A2-mediated release of arachidonic acid, followed by its enzymatic oxidation resulting in a vast array of eicosanoid products. However, recent work has demonstrated that the major phospholipase in mitochondria, iPLA2γ (patatin-like phospholipase domain containing 8 (PNPLA8)), possesses sn-1 specificity, with polyunsaturated fatty acids at the sn-2 position generating polyunsaturated sn-2-acyl lysophospholipids. Through strategic chemical derivatization, chiral chromatographic separation, and multistage tandem MS, here we first demonstrate that human platelet-type 12-lipoxygenase (12-LOX) can directly catalyze the regioselective and stereospecific oxidation of 2-arachidonoyl-lysophosphatidylcholine (2-AA-LPC) and 2-arachidonoyl-lysophosphatidylethanolamine (2-AA-LPE). Next, we identified these two eicosanoid-lysophospholipids in murine myocardium and in isolated platelets. Moreover, we observed robust increases in 2-AA-LPC, 2-AA-LPE, and their downstream 12-LOX oxidation products, 12(S)-HETE-LPC and 12(S)-HETE-LPE, in calcium ionophore (A23187)-stimulated murine platelets. Mechanistically, genetic ablation of iPLA2γ markedly decreased the calcium-stimulated production of 2-AA-LPC, 2-AA-LPE, and 12-HETE-lysophospholipids in mouse platelets. Importantly, a potent and selective 12-LOX inhibitor, ML355, significantly inhibited the production of 12-HETE-LPC and 12-HETE-LPE in activated platelets. Furthermore, we found that aging is accompanied by significant changes in 12-HETE-LPC in murine serum that were also markedly attenuated by iPLA2γ genetic ablation. Collectively, these results identify previously unknown iPLA2γ-initiated signaling pathways mediated by direct 12-LOX oxidation of 2-AA-LPC and 2-AA-LPE. This oxidation generates previously unrecognized eicosanoid-lysophospholipids that may serve as biomarkers for age-related diseases and could potentially be used as targets in therapeutic interventions.




xi

X-ray structures of catalytic intermediates of cytochrome c oxidase provide insights into its O2 activation and unidirectional proton-pump mechanisms [Molecular Biophysics]

Cytochrome c oxidase (CcO) reduces O2 to water, coupled with a proton-pumping process. The structure of the O2-reduction site of CcO contains two reducing equivalents, Fea32+ and CuB1+, and suggests that a peroxide-bound state (Fea33+–O−–O−–CuB2+) rather than an O2-bound state (Fea32+–O2) is the initial catalytic intermediate. Unexpectedly, however, resonance Raman spectroscopy results have shown that the initial intermediate is Fea32+–O2, whereas Fea33+–O−–O−–CuB2+ is undetectable. Based on X-ray structures of static noncatalytic CcO forms and mutation analyses for bovine CcO, a proton-pumping mechanism has been proposed. It involves a proton-conducting pathway (the H-pathway) comprising a tandem hydrogen-bond network and a water channel located between the N- and P-side surfaces. However, a system for unidirectional proton-transport has not been experimentally identified. Here, an essentially identical X-ray structure for the two catalytic intermediates (P and F) of bovine CcO was determined at 1.8 Å resolution. A 1.70 Å Fe–O distance of the ferryl center could best be described as Fea34+ = O2−, not as Fea34+–OH−. The distance suggests an ∼800-cm−1 Raman stretching band. We found an interstitial water molecule that could trigger a rapid proton-coupled electron transfer from tyrosine-OH to the slowly forming Fea33+–O−–O−–CuB2+ state, preventing its detection, consistent with the unexpected Raman results. The H-pathway structures of both intermediates indicated that during proton-pumping from the hydrogen-bond network to the P-side, a transmembrane helix closes the water channel connecting the N-side with the hydrogen-bond network, facilitating unidirectional proton-pumping during the P-to-F transition.




xi

Reduction of protein phosphatase 2A (PP2A) complexity reveals cellular functions and dephosphorylation motifs of the PP2A/B'{delta} holoenzyme [Enzymology]

Protein phosphatase 2A (PP2A) is a large enzyme family responsible for most cellular Ser/Thr dephosphorylation events. PP2A substrate specificity, localization, and regulation by second messengers rely on more than a dozen regulatory subunits (including B/R2, B'/R5, and B″/R3), which form the PP2A heterotrimeric holoenzyme by associating with a dimer comprising scaffolding (A) and catalytic (C) subunits. Because of partial redundancy and high endogenous expression of PP2A holoenzymes, traditional approaches of overexpressing, knocking down, or knocking out PP2A regulatory subunits have yielded only limited insights into their biological roles and substrates. To this end, here we sought to reduce the complexity of cellular PP2A holoenzymes. We used tetracycline-inducible expression of pairs of scaffolding and regulatory subunits with complementary charge-reversal substitutions in their interaction interfaces. For each of the three regulatory subunit families, we engineered A/B charge–swap variants that could bind to one another, but not to endogenous A and B subunits. Because endogenous Aα was targeted by a co-induced shRNA, endogenous B subunits were rapidly degraded, resulting in expression of predominantly a single PP2A heterotrimer composed of the A/B charge–swap pair and the endogenous catalytic subunit. Using B'δ/PPP2R5D, we show that PP2A complexity reduction, but not PP2A overexpression, reveals a role of this holoenzyme in suppression of extracellular signal–regulated kinase signaling and protein kinase A substrate dephosphorylation. When combined with global phosphoproteomics, the PP2A/B'δ reduction approach identified consensus dephosphorylation motifs in its substrates and suggested that residues surrounding the phosphorylation site play roles in PP2A substrate specificity.




xi

Cancer survivors' experiences with financial toxicity

(Wiley) A recent Psycho-Oncology analysis of published studies found that few cancer survivors received financial information support from healthcare facilities during their initial treatment, even though cancer-related financial toxicity has multiple impacts on survivors' health and quality of life.




xi

Cool Met Stuff, composition of air, main gases, climate change, global warming, carbon dioxide concentration, fraction, atmosphere

Do you know which main gases are contained in the composition of air? Under climate change and global warming, carbon dioxide ...




xi

Safely relaxing social distancing comes down to numbers

(Queensland University of Technology) Your house number could be the key to the safe relaxation of COVID-19-related restrictions if governments follow a new exit strategy proposal published today in the British Medical Journal. Co-authored by QUT statistician Professor Adrian Barnett, the paper proposes the use of an 'odds-and-evens' approach to allowing people to head back to work and enjoy other activities after weeks of lockdown.




xi

Gravitational waves could prove the existence of the quark-gluon plasma

(Goethe University Frankfurt) According to modern particle physics, matter produced when neutron stars merge is so dense that it could exist in a state of dissolved elementary particles. This state of matter, called quark-gluon plasma, might produce a specific signature in gravitational waves. Physicists at Goethe University Frankfurt and the Frankfurt Institute for Advanced Studies have now calculated this process using supercomputers.




xi

New study examines which galaxies are best for intelligent life

(University of Arkansas) Giant elliptical galaxies are not as likely as disk-shaped galaxies, such as our own Milky Way, to be cradles of technological civilizations, according to a recent paper by a University of Arkansas astrophysicist.




xi

Study: could dark matter be hiding in existing data?

(DOE/Lawrence Berkeley National Laboratory) A new study, led by researchers at Berkeley Lab and UC Berkeley, suggests new paths for catching the signals of dark matter particles that have their energy absorbed by atomic nuclei.




xi

African skeletons from early colonial Mexico tell the story of first-generation slaves

(Max Planck Institute for the Science of Human History) Three 16th-century skeletons from a mass burial in Mexico City highlight the role of the transatlantic slave trade in introducing and disseminating new pathogens to the Americas. Researchers from the Max Planck Institute for the Science of Human History and Escuela Nacional de Antropología e Historia in Mexico analyzed skeletal features, genetic data and isotopes to explore the life history of three enslaved Africans and explore the wide-ranging impacts of massive forced migration.




xi

Mats made from nanofibers linked to a red wine chemical could help prevent oxidation

(Texas A&M University) Spoiling foods, souring wine and worsening wounds have a common culprit -- a process called oxidation. Although the ill effects of these chemical reactions can be curtailed by antioxidants, creating a sturdy platform capable of providing prolonged antioxidant activity is an ongoing challenge.




xi

FSU researchers study Gulf of Mexico in international collaboration

(Florida State University) Florida State University and partner universities investigated current baseline conditions in the southern Gulf to create a series of maps and guides that detail the distribution of carbon, nitrogen and the carbon-14 isotope.




xi

12-LOX catalyzes the oxidation of 2-arachidonoyl-lysolipids in platelets generating eicosanoid-lysolipids that are attenuated by iPLA2{gamma} knockout [Signal Transduction]

The canonical pathway of eicosanoid production in most mammalian cells is initiated by phospholipase A2-mediated release of arachidonic acid, followed by its enzymatic oxidation resulting in a vast array of eicosanoid products. However, recent work has demonstrated that the major phospholipase in mitochondria, iPLA2γ (patatin-like phospholipase domain containing 8 (PNPLA8)), possesses sn-1 specificity, with polyunsaturated fatty acids at the sn-2 position generating polyunsaturated sn-2-acyl lysophospholipids. Through strategic chemical derivatization, chiral chromatographic separation, and multistage tandem MS, here we first demonstrate that human platelet-type 12-lipoxygenase (12-LOX) can directly catalyze the regioselective and stereospecific oxidation of 2-arachidonoyl-lysophosphatidylcholine (2-AA-LPC) and 2-arachidonoyl-lysophosphatidylethanolamine (2-AA-LPE). Next, we identified these two eicosanoid-lysophospholipids in murine myocardium and in isolated platelets. Moreover, we observed robust increases in 2-AA-LPC, 2-AA-LPE, and their downstream 12-LOX oxidation products, 12(S)-HETE-LPC and 12(S)-HETE-LPE, in calcium ionophore (A23187)-stimulated murine platelets. Mechanistically, genetic ablation of iPLA2γ markedly decreased the calcium-stimulated production of 2-AA-LPC, 2-AA-LPE, and 12-HETE-lysophospholipids in mouse platelets. Importantly, a potent and selective 12-LOX inhibitor, ML355, significantly inhibited the production of 12-HETE-LPC and 12-HETE-LPE in activated platelets. Furthermore, we found that aging is accompanied by significant changes in 12-HETE-LPC in murine serum that were also markedly attenuated by iPLA2γ genetic ablation. Collectively, these results identify previously unknown iPLA2γ-initiated signaling pathways mediated by direct 12-LOX oxidation of 2-AA-LPC and 2-AA-LPE. This oxidation generates previously unrecognized eicosanoid-lysophospholipids that may serve as biomarkers for age-related diseases and could potentially be used as targets in therapeutic interventions.




xi

Arginine in C9ORF72 Dipolypeptides Mediates Promiscuous Proteome Binding and Multiple Modes of Toxicity

Mona Radwan
Apr 1, 2020; 19:640-654
Research




xi

Characterization of signaling pathways associated with pancreatic {beta}-cell adaptive flexibility in compensation of obesity-linked diabetes in db/db mice

Taewook Kang
Apr 7, 2020; 0:RA119.001882v1-mcp.RA119.001882
Research




xi

Proximity Dependent Biotinylation: Key Enzymes and Adaptation to Proteomics Approaches

Payman Samavarchi-Tehrani
May 1, 2020; 19:757-773
Review




xi

PARP-1-targeted Auger emitters display high-LET cytotoxic properties in vitro but show limited therapeutic utility in solid tumor models of human neuroblastoma

The currently available therapeutic radiopharmaceutical for high-risk neuroblastoma, 131I-MIBG, is ineffective at targeting micrometastases due to the low linear energy transfer (LET) properties of high-energy beta particles. In contrast, Auger radiation has high-LET properties with nanometer ranges in tissue, efficiently causing DNA damage when emitted in close proximity to DNA. The aim of this study was to evaluate the cytotoxicity of targeted Auger therapy in pre-clinical models of high-risk neuroblastoma. Methods: Using a radiolabeled poly(ADP-ribose) polymerase (PARP) inhibitor, 125I-KX1, we delivered an Auger emitter iodine-125 to PARP-1: a chromatin-binding enzyme overexpressed in neuroblastoma. In vitro cytotoxicity of 125I-KX1 was assessed in nineteen neuroblastoma cell lines, followed by in-depth pharmacological analysis in a sensitive and resistant pair of cell lines. Immunofluorescence microscopy was used to characterize 125I-KX1-induced DNA damage. Finally, in vitro/in vivo microdosimetry was modeled from experimentally derived pharmacological variables. Results: 125I-KX1 was highly cytotoxic in vitro across a panel of neuroblastoma cell lines, directly causing double strand DNA breaks. Based on subcellular dosimetry, 125I-KX1 was approximately twice as effective compared to 131I-KX1, whereas cytoplasmic 125I-MIBG demonstrated low biological effectiveness. Despite the ability to deliver focused radiation dose to the cell nuclei, 125I-KX1 remained less effective than its alpha-emitting analog 211At-MM4, and required significantly higher activity for equivalent in vivo efficacy based on tumor microdosimetry. Conclusion: Chromatin-targeted Auger therapy is lethal to high-risk neuroblastoma cells with potential use in micrometastatic disease. This study provides the first evidence for cellular lethality from a PARP-1 targeted Auger emitter, calling for further investigation into targeted Auger therapy.




xi

Combined Visual and Semi-quantitative Evaluation Improves Outcome Prediction by Early Mid-treatment 18F-fluoro-deoxi-glucose Positron Emission Tomography in Diffuse Large B-cell Lymphoma.

The purpose of this study was to assess the predictive and prognostic value of interim FDG PET (iPET) in evaluating early response to immuno-chemotherapy after two cycles (PET-2) in diffuse large B-cell lymphoma (DLBCL) by applying two different methods of interpretation: the Deauville visual five-point scale (5-PS) and a change in standardised uptake value by semi-quantitative evaluation. Methods: 145 patients with newly diagnosed DLBCL underwent pre-treatment PET (PET-0) and PET-2 assessment. PET-2 was classified according to both the visual 5-PS and percentage SUV changes (SUV). Receiver operating characteristic (ROC) analysis was performed to compare the accuracy of the two methods for predicting progression-free survival (PFS). Survival estimates, based on each method separately and combined, were calculated for iPET-positive (iPET+) and iPET-negative (iPET–) groups and compared. Results: Both with visual and SUV-based evaluations significant differences were found between the PFS of iPET– and iPET+ patient groups (p<0.001). Visually the best negative (NPV) and positive predictive value (PPV) occurred when iPET was defined as positive if Deauville score 4-5 (89% and 59%, respectively). Using the 66% SUV cut-off value, reported previously, NPV and PPV were 80 and 76%, respectively. SUV at 48.9% cut-off point, reported for the first time here, produced 100% specificity along with the highest sensitivity (24%). Visual and semi-quantitative SUV<48.9% assessment of each PET-2 gave the same PET-2 classification (positive or negative) in 70% (102/145) of all patients. This combined classification delivered NPV and PPV of 89% and 100% respectively, and all iPET+ patients failed to achieve or remain in remission. Conclusion: In this large consistently treated and assessed series of DLBCL, iPET had good prognostic value interpreted either visually or semi-quantitatively. We determined that the most effective SUV cut-off was at 48.9%, and that when combined with visual 5-PS assessment, a positive PET-2 was highly predictive of treatment failure.




xi

177Lu-lilotomab satetraxetan has the potential to counteract resistance to rituximab in non-Hodgkins lymphoma

Background: Patients with NHL who are treated with rituximab may develop resistant disease, often associated with changes in expression of CD20. The next generation β-particle emitting radioimmunoconjugate 177Lu-lilotomab-satetraxetan (Betalutin®) was shown to up-regulate CD20 expression in different rituximab-sensitive NHL cell lines and to act synergistically with rituximab in a rituximab-sensitive NHL animal model. We hypothesized that 177Lu-lilotomab-satetraxetan may be used to reverse rituximab-resistance in NHL. Methods: The rituximab-resistant Raji2R and the parental Raji cell lines were used. CD20 expression was measured by flow cytometry. ADCC was measured by a bioluminescence reporter assay. The efficacies of combined treatments with 177Lu-lilotomab-satetraxetan (150MBq/kg or 350MBq/kg) and rituximab (4x10mg/kg) were compared with those of single agents or saline in a Raji2R-xenograft model. Cox-regression and the Bliss independence model were used to assess synergism. Results: Rituximab-binding in Raji2R cells was 36±5% of that in the rituximab-sensitive Raji cells. 177Lu-lilotomab-satetraxetan treatment of Raji2R cells increased the binding to 53±3% of the parental cell line. Rituximab ADCC-induction in Raji2R cells was 20±2% of that induced in Raji cells, while treatment with 177Lu-lilotomab-satetraxetan increased the ADCC-induction to 30±3% of the Raji cells, representing a 50% increase (p<0.05). The combination of rituximab with 350MBq/kg 177Lu-lilotomab-satetraxetan synergistically suppressed Raji2R tumor growth in athymic Foxn1nu mice. Conclusion: 177Lu-lilotomab-satetraxetan has the potential to reverse rituximab-resistance; it increases binding and ADCC-activity in-vitro and can synergistically improve anti-tumor efficacy in-vivo.




xi

Arginine in C9ORF72 Dipolypeptides Mediates Promiscuous Proteome Binding and Multiple Modes of Toxicity [Research]

C9ORF72-associated Motor Neuron Disease patients feature abnormal expression of 5 dipeptide repeat (DPR) polymers. Here we used quantitative proteomics in a mouse neuronal-like cell line (Neuro2a) to demonstrate that the Arg residues in the most toxic DPRS, PR and GR, leads to a promiscuous binding to the proteome compared with a relative sparse binding of the more inert AP and GA. Notable targets included ribosomal proteins, translation initiation factors and translation elongation factors. PR and GR comprising more than 10 repeats appeared to robustly stall on ribosomes during translation suggesting Arg-rich peptide domains can electrostatically jam the ribosome exit tunnel during synthesis. Poly-GR also recruited arginine methylases, induced hypomethylation of endogenous proteins, and induced a profound destabilization of the actin cytoskeleton. Our findings point to arginine in GR and PR polymers as multivalent toxins to translation as well as arginine methylation that may explain the dysfunction of biological processes including ribosome biogenesis, mRNA splicing and cytoskeleton assembly.




xi

Decreased Immunoglobulin G Core Fucosylation, A Player in Antibody-dependent Cell-mediated Cytotoxicity, is Associated with Autoimmune Thyroid Diseases [Research]

Autoimmune thyroid diseases (AITD) are the most common group of autoimmune diseases, associated with lymphocyte infiltration and the production of thyroid autoantibodies, like thyroid peroxidase antibodies (TPOAb), in the thyroid gland. Immunoglobulins and cell-surface receptors are glycoproteins with distinctive glycosylation patterns that play a structural role in maintaining and modulating their functions. We investigated associations of total circulating IgG and peripheral blood mononuclear cells glycosylation with AITD and the influence of genetic background in a case-control study with several independent cohorts and over 3,000 individuals in total. The study revealed an inverse association of IgG core fucosylation with TPOAb and AITD, as well as decreased peripheral blood mononuclear cells antennary α1,2 fucosylation in AITD, but no shared genetic variance between AITD and glycosylation. These data suggest that the decreased level of IgG core fucosylation is a risk factor for AITD that promotes antibody-dependent cell-mediated cytotoxicity previously associated with TPOAb levels.




xi

Proximity Dependent Biotinylation: Key Enzymes and Adaptation to Proteomics Approaches [Reviews]

The study of protein subcellular distribution, their assembly into complexes and the set of proteins with which they interact with is essential to our understanding of fundamental biological processes. Complementary to traditional assays, proximity-dependent biotinylation (PDB) approaches coupled with mass spectrometry (such as BioID or APEX) have emerged as powerful techniques to study proximal protein interactions and the subcellular proteome in the context of living cells and organisms. Since their introduction in 2012, PDB approaches have been used in an increasing number of studies and the enzymes themselves have been subjected to intensive optimization. How these enzymes have been optimized and considerations for their use in proteomics experiments are important questions. Here, we review the structural diversity and mechanisms of the two main classes of PDB enzymes: the biotin protein ligases (BioID) and the peroxidases (APEX). We describe the engineering of these enzymes for PDB and review emerging applications, including the development of PDB for coincidence detection (split-PDB). Lastly, we briefly review enzyme selection and experimental design guidelines and reflect on the labeling chemistries and their implication for data interpretation.




xi

A peroxisome deficiency-induced reductive cytosol state up-regulates the brain-derived neurotrophic factor pathway [Metabolism]

The peroxisome is a subcellular organelle that functions in essential metabolic pathways, including biosynthesis of plasmalogens, fatty acid β-oxidation of very-long-chain fatty acids, and degradation of hydrogen peroxide. Peroxisome biogenesis disorders (PBDs) manifest as severe dysfunction in multiple organs, including the central nervous system (CNS), but the pathogenic mechanisms in PBDs are largely unknown. Because CNS integrity is coordinately established and maintained by neural cell interactions, we here investigated whether cell-cell communication is impaired and responsible for the neurological defects associated with PBDs. Results from a noncontact co-culture system consisting of primary hippocampal neurons with glial cells revealed that a peroxisome-deficient astrocytic cell line secretes increased levels of brain-derived neurotrophic factor (BDNF), resulting in axonal branching of the neurons. Of note, the BDNF expression in astrocytes was not affected by defects in plasmalogen biosynthesis and peroxisomal fatty acid β-oxidation in the astrocytes. Instead, we found that cytosolic reductive states caused by a mislocalized catalase in the peroxisome-deficient cells induce the elevation in BDNF secretion. Our results suggest that peroxisome deficiency dysregulates neuronal axogenesis by causing a cytosolic reductive state in astrocytes. We conclude that astrocytic peroxisomes regulate BDNF expression and thereby support neuronal integrity and function.




xi

Inhibition of the polyamine synthesis enzyme ornithine decarboxylase sensitizes triple-negative breast cancer cells to cytotoxic chemotherapy [Molecular Bases of Disease]

Treatment of patients with triple-negative breast cancer (TNBC) is limited by a lack of effective molecular therapies targeting this disease. Recent studies have identified metabolic alterations in cancer cells that can be targeted to improve responses to standard-of-care chemotherapy regimens. Using MDA-MB-468 and SUM-159PT TNBC cells, along with LC-MS/MS and HPLC metabolomics profiling, we found here that exposure of TNBC cells to the cytotoxic chemotherapy drugs cisplatin and doxorubicin alter arginine and polyamine metabolites. This alteration was because of a reduction in the levels and activity of a rate-limiting polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). Using gene silencing and inhibitor treatments, we determined that the reduction in ODC was mediated by its negative regulator antizyme, targeting ODC to the proteasome for degradation. Treatment with the ODC inhibitor difluoromethylornithine (DFMO) sensitized TNBC cells to chemotherapy, but this was not observed in receptor-positive breast cancer cells. Moreover, TNBC cell lines had greater sensitivity to single-agent DFMO, and ODC levels were elevated in TNBC patient samples. The alterations in polyamine metabolism in response to chemotherapy, as well as DFMO-induced preferential sensitization of TNBC cells to chemotherapy, reported here suggest that ODC may be a targetable metabolic vulnerability in TNBC.




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Uber and the ATO's $3.8 million taxi fare

Tax Office could turn to rideshare service to curb $3.8 million taxi fare




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Brexit: What Now for UK Trade Policy? (Part 2)

Research Event

1 October 2019 - 12:30pm to 1:30pm

Chatham House | 10 St James's Square | London | SW1Y 4LE

Event participants

Professor Jagjit S. Chadha, Director, NIESR
Dr Kamala Dawar, Senior Lecturer in Law, University of Sussex; Fellow, UKTPO
Dr Michael Gasiorek, Senior Lecturer in Economics, University of Sussex; Director, Interanalysis; Fellow, UKTPO
Chair: Professor Jim Rollo, Deputy Director, UKTPO; Associate Fellow, Chatham House

In the five months since the last extension of the Brexit deadline, the questions about the UK’s trading relationship with the EU remain as open as before, as do those about what sort of relationship it should seek with other partners.

The world has not stood still, however, and so the UKTPO is convening another panel to consider constructive ways of moving forward. The panel will discuss potential trajectories for UK trade policy, followed by a question and answer session.

The UK Trade Policy Observatory (UKTPO) is a partnership between Chatham House and the University of Sussex which provides independent expert comment on, and analysis of, trade policy proposals for the UK as well as training for British policymakers through tailored training packages.




xi

Could Brexit Open Up a New Market for Latin American Agriculture?

8 October 2019

Dr Christopher Sabatini

Senior Research Fellow for Latin America, US and the Americas Programme

Anar Bata

Coordinator, US and the Americas Programme
The demand will be there, but a range of barriers are likely to limit growth in agricultural trade links between the UK and Latin America.

2019-10-08-Brazil.jpg

An area of forest-pasture integration prepared to receive dairy cattle for feeding in Ipameri, Brazil. Photo: Getty Images.

Currently 73% of all UK agricultural imports come from the EU. That heavy dependence sparked a report by the British parliament expressing concern about the UK’s food security in the immediate aftermath of Brexit.

Meanwhile, Latin America’s agricultural powerhouses Brazil and Argentina only accounted for a total of 1.6% of the UK’s agricultural market across eight sectors in 2018. A growing relationship would seem to be an obvious fit post-Brexit – but a number of structural issues stand in the way.

There is certainly scope for increasing Latin American agricultural exports to the UK given current trade patterns. Two of the main agricultural imports that the UK buys from the EU are meat products, representing 82% of UK imports in that category, and dairy products and eggs; 98% of UK’s dairy- and egg-related external supply came from the EU. In both these areas, Brazil and Argentina could have comparative advantages, including lower prices.

But any improvement in agricultural trade links will depend on two factors: 1) how the UK leaves the EU: whether it crashes out, negotiates an easy exit or leaves at all; and 2) whether Latin American agricultural producers can improve their environmental practices and can meet the production standards established by the EU and likely maintained by a post-Brexit Britain.

Some of the key issues that will affect this are:

Tariff structures

On the UK side, there is pressure by domestic agricultural producers to raise UK tariffs to allow them to expand their local market share. Yet, despite the pressures from local farmers, the UK has laid out two scenarios.

In one case, the UK government has stated that in the event of a no-deal Brexit, tariffs will be lowered to 0%, but there is no firm commitment and this would likely be temporary. It is also unlikely that those would apply to all agricultural products. In the case of beef imports (of which Argentina and Brazil are major exporters), the UK has proposed that ‘no deal’ would bring a reduction on tariffs on a range of beef products of roughly half.

Meanwhile, tariffs on EU imports could go up. Even if the UK establishes 0% tariffs on EU products, it’s possible that the EU will not reciprocate, instead choosing to revert to the World Trade Organization’s most-favoured-nation tariffs. To take one example of what that would mean, under existing most-favoured-nation tariffs on beef, the tariffs range from €6.80 per 100 kilograms of full bovine carcasses or half carcasses all the way up to €161.10 for 160 kilograms of prepared or preserved meat, including sausages.

Free trade agreements between the EU and Latin American countries

The EU has free trade agreements with the Central American bloc of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama; Mexico; Chile; and the Andean countries of Colombia, Ecuador, and Peru. In all those cases, the UK has expressed its desire to maintain its liberal trade framework with those countries.

Even if the UK leaves without a deal and tariffs do increase on EU agricultural exports, though, these Western Hemisphere economies are unlikely to see a large boost in their food exports to the UK. Chile and other large fruit producers are already locked into the Chinese market. And the real agricultural powerhouses, Argentina and Brazil, are now part of the EU trade agreement with Mercosur.

Since that agreement is not yet in force, the UK and Mercosur would need to negotiate a separate agreement. Such an agreement may be easier to ratify than the EU agreement since there is only one partner (the UK) for such a deal, but the likely change in government in Argentina after the 27 October elections may make it difficult to secure a deal on the Mercosur side.

Some EU trade agreements also include arrangements for tariff rate quotas. An EU quota with Argentina, for example, allows more than 280,000 tonnes of lamb to be imported to the EU duty free from Argentina, among other countries. It is unclear whether these quotas will be maintained or even expanded by the UK post-Brexit.  

Phytosanitary standards and rules governing the treatment of animals

Non-tariff barriers concerning production practices could play a key role. The large UK consumer organization Which? raised the concern before parliament that in the scramble to replace EU food imports, the UK could diverge from EU standards on animal cloning, the use of growth hormones and hygiene in poultry production. Pressure to maintain those standards would likely exclude many products from South America.

Beyond the regulatory barriers, there is also the possibility that UK consumers may reject agricultural products produced in less sustainable and humane conditions, or in countries (such as Brazil) that are seen by the public as abusing the environment.

In short, an increase in Latin American agricultural exports to the UK market may not happen as easily or as quickly as some hope after Brexit. In fact, it may not happen at all. But if Latin American countries – Argentina and Brazil in particular – want to capture this potential new market, the first step both should be to improve their environmental profile and standards at both the government and producer level.




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Brexit identities and British public opinion on China

6 November 2019 , Volume 95, Number 6

Wilfred M. Chow, Enze Han and Xiaojun Li

Many studies have explored the importance of public opinion in British foreign policy decision-making, especially when it comes to the UK's relations with the United States and the European Union. Despite its importance, there is a dearth of research on public opinion about British foreign policy towards other major players in the international system, such as emerging powers like China. We have addressed this knowledge gap by conducting a public opinion survey in the UK after the Brexit referendum. Our research findings indicate that the British public at large finds China's rise disconcerting, but is also pragmatic in its understanding of how the ensuing bilateral relations should be managed. More importantly, our results show that views on China are clearly split between the two opposing Brexit identities. Those who subscribe strongly to the Leave identity, measured by their aversion to the EU and antipathy towards immigration, are also more likely to hold negative perceptions of Chinese global leadership and be more suspicious of China as a military threat. In contrast, those who espouse a Remain identity—that is, believe that Britain would be better served within the EU and with more immigrants—are more likely to prefer closer engagement with China and to have a more positive outlook overall on China's place within the global community.




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Circulating oxidized LDL increased in patients with acute myocardial infarction is accompanied by heavily modified HDL.

Naoko Sawada
Apr 14, 2020; 0:jlr.RA119000312v1-jlr.RA119000312
Research Articles




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Episode 23 - The Internet of Top Tech Topics (IoTTT) Brexit, Pokemon Go & Tesla

For the second week running hosting duties are taken by Henry Burrell, who is joined by Techworld.com editor Charlotte Jee to discuss the impact of Brexit on the UK's startups. Producer Chris then jumps in to discuss the Pokemon Go launch in the UK and a debate breaks out over whether it is for adults (13:00) Finally, online editor at Computerworld UK Scott Carey brings the latest news around driverless cars, from Tesla's recent struggles and how it may affect the industry in general (25:00)  


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Episode 30 - The Internet of Unlimited Play-Doh (IoUPD): Amazon Dash, Apple tax and headphone sexism

This week Ashleigh Allsopp is simultaneously fascinated and worried by the UK launch of Amazon's Dash buttons, and discusses the many wonderful and not-so-wonderful things they enable you to buy on a drunken whim. Then David Price takes his turn to shine a spotlight on Apple's mysterious tax affairs (12:20) and tries to explain why the Irish government doesn't want to be given 13 billion euros. Finally a surprisingly riled-up Neil Bennett explains why women wearing headphones are not fair game for dimwitted pick-up artists (25:00), and ponders the social conventions surrounding the place of technology in each of our lives.  


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Episode 52 - The Internet of Nostalgia (IoN) Nokia 3310, drone taxis and Apple on the telly

Matt Egan takes us where no other pod has dared gone before (September 2000) and asks Digital Arts Editor Neil Bennett if anyone cares that Nokia is rereleasing the famous 3310. Is it cool to rock one now? Then Techworld Audience Development Editor Christina Mercer lets us know that the future is already here with self driving drone taxis. Would you hitch a lift round Dubai on a massive quadcopter? Finally Deputy Editor at Macworld David Price ruminates on Apple's forecast foray into the world of snackable media content - will it challenge Netflix or try to buy it?  


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Episode 69 - The Internet of internal memos (IoIM) Google sexism row and iPhone 8 leaks

Join Miriam Harris, David Price and Henry Burrell as they dissect the weird internal memo row at Google. Was a male engineer genuinely trying to help Google and make a point about the company being too Left, or is he just an arsehole? Then we describe the iPhone 8 dummy we received this week (take a look at it here: https://www.youtube.com/watch?v=PRNIwh61j_E ) and the revelations that came from the Homepod firmware leak. We also debate the usefulness of an LTE Apple Watch and try to make puns work. Magic.  


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