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pH-dependent pyridoxine transport by SLC19A2 and SLC19A3: Implications for absorption in acidic microclimates [Metabolism]

SLC19A2 and SLC19A3, also known as thiamine transporters (THTR) 1 and 2, respectively, transport the positively charged thiamine (vitamin B1) into cells to enable its efficient utilization. SLC19A2 and SLC19A3 are also known to transport structurally unrelated cationic drugs, such as metformin, but whether this charge selectivity extends to other molecules, such as pyridoxine (vitamin B6), is unknown. We tested this possibility using Madin-Darby canine kidney II (MDCKII) cells and human embryonic kidney 293 (HEK293) cells for transfection experiments, and also using Caco-2 cells as human intestinal epithelial model cells. The stable expression of SLC19A2 and SLC19A3 in MDCKII cells (as well as their transient expression in HEK293 cells) led to a significant induction in pyridoxine uptake at pH 5.5 compared with control cells. The induced uptake was pH-dependent, favoring acidic conditions over neutral to basic conditions, and protonophore-sensitive. It was saturable as a function of pyridoxine concentration, with an apparent Km of 37.8 and 18.5 μm, for SLC19A2 and SLC19A3, respectively, and inhibited by the pyridoxine analogs pyridoxal and pyridoxamine as well as thiamine. We also found that silencing the endogenous SLC19A3, but not SLC19A2, of Caco-2 cells with gene-specific siRNAs lead to a significant reduction in carrier-mediated pyridoxine uptake. These results show that SLC19A2 and SLC19A3 are capable of recognizing/transporting pyridoxine, favoring acidic conditions for operation, and suggest a possible role for these transporters in pyridoxine transport mainly in tissues with an acidic environment like the small intestine, which has an acidic surface microclimate.




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{alpha}-Synuclein facilitates endocytosis by elevating the steady-state levels of phosphatidylinositol 4,5-bisphosphate [Membrane Biology]

α-Synuclein (α-Syn) is a protein implicated in the pathogenesis of Parkinson's disease (PD). It is an intrinsically disordered protein that binds acidic phospholipids. Growing evidence supports a role for α-Syn in membrane trafficking, including, mechanisms of endocytosis and exocytosis, although the exact role of α-Syn in these mechanisms is currently unclear. Here we investigate the associations of α-Syn with the acidic phosphoinositides (PIPs), phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2). Our results show that α-Syn colocalizes with PIP2 and the phosphorylated active form of the clathrin adaptor protein 2 (AP2) at clathrin-coated pits. Using endocytosis of transferrin as an indicator for clathrin-mediated endocytosis (CME), we find that α-Syn involvement in endocytosis is specifically mediated through PI(4,5)P2 levels on the plasma membrane. In accord with their effects on PI(4,5)P2 levels, the PD associated A30P, E46K, and A53T mutations in α-Syn further enhance CME in neuronal and nonneuronal cells. However, lysine to glutamic acid substitutions at the KTKEGV repeat domain of α-Syn, which interfere with phospholipid binding, are ineffective in enhancing CME. We further show that the rate of synaptic vesicle (SV) endocytosis is differentially affected by the α-Syn mutations and associates with their effects on PI(4,5)P2 levels, however, with the exception of the A30P mutation. This study provides evidence for a critical involvement of PIPs in α-Syn–mediated membrane trafficking.




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The Insulin Receptor Adaptor IRS2 is an APC/C Substrate That Promotes Cell Cycle Protein Expression and a Robust Spindle Assembly Checkpoint [Research]

Insulin receptor substrate 2 (IRS2) is an essential adaptor that mediates signaling downstream of the insulin receptor and other receptor tyrosine kinases. Transduction through IRS2-dependent pathways is important for coordinating metabolic homeostasis, and dysregulation of IRS2 causes systemic insulin signaling defects. Despite the importance of maintaining proper IRS2 abundance, little is known about what factors mediate its protein stability. We conducted an unbiased proteomic screen to uncover novel substrates of the Anaphase Promoting Complex/Cyclosome (APC/C), a ubiquitin ligase that controls the abundance of key cell cycle regulators. We found that IRS2 levels are regulated by APC/C activity and that IRS2 is a direct APC/C target in G1. Consistent with the APC/C's role in degrading cell cycle regulators, quantitative proteomic analysis of IRS2-null cells revealed a deficiency in proteins involved in cell cycle progression. We further show that cells lacking IRS2 display a weakened spindle assembly checkpoint in cells treated with microtubule inhibitors. Together, these findings reveal a new pathway for IRS2 turnover and indicate that IRS2 is a component of the cell cycle control system in addition to acting as an essential metabolic regulator.




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High-dimensional Cytometry (ExCYT) and Mass Spectrometry of Myeloid Infiltrate in Clinically Localized Clear Cell Renal Cell Carcinoma Identifies Novel Potential Myeloid Targets for Immunotherapy [Research]

Renal Cell Carcinoma (RCC) is one of the most commonly diagnosed cancers worldwide with research efforts dramatically improving understanding of the biology of the disease. To investigate the role of the immune system in treatment-naïve clear cell Renal Cell Carcinoma (ccRCC), we interrogated the immune infiltrate in patient-matched ccRCC tumor samples, benign normal adjacent tissue (NAT) and peripheral blood mononuclear cells (PBMCs isolated from whole blood, focusing our attention on the myeloid cell infiltrate. Using flow cytometric, MS, and ExCYT analysis, we discovered unique myeloid populations in PBMCs across patient samples. Furthermore, normal adjacent tissues and ccRCC tissues contained numerous myeloid populations with a unique signature for both tissues. Enrichment of the immune cell (CD45+) fraction and subsequent gene expression analysis revealed a number of myeloid-related genes that were differentially expressed. These data provide evidence, for the first time, of an immunosuppressive and pro-tumorigenic role of myeloid cells in early, clinically localized ccRCC. The identification of a number of immune proteins for therapeutic targeting provides a rationale for investigation into the potential efficacy of earlier intervention with single-agent or combination immunotherapy for ccRCC.




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Novel Proteomic Profiling of Epididymal Extracellular Vesicles in the Domestic Cat Reveals Proteins Related to Sequential Sperm Maturation with Differences Observed between Normospermic and Teratospermic Individuals [Research]

Extracellular vesicles (EVs) secreted by the epididymal epithelium transfer to spermatozoa key proteins that are essential in promoting motility and subsequent fertilization success. Using the domestic cat model, the objectives were to (1) characterize and compare protein content of EVs between segments of the epididymis, and (2) compare EV protein compositions between normo- and teratospermic individuals (producing >60% of abnormal spermatozoa). Epididymal EVs from adult cats were isolated and assessed via liquid chromatography tandem MS. Both male types shared 3008 proteins in total, with 98 and 20 EV proteins unique to normospermic and teratospermic males, respectively. Expression levels of several proteins changed between epididymal segments in both male types. Several proteins in both groups were related to sperm motility (e.g. hexokinase 1, adenylate kinase isoenzyme) and zona pellucida or oolemma binding (e.g. disintegrin and metalloproteinase domain proteins, zona binding proteins 1 and 2). Interestingly, seven cauda-derived EV proteins trended downward in teratospermic compared with normospermic males, which may relate to poor sperm quality. Collective results revealed, for the first time, EV proteins related to sequential sperm maturation with differences observed between normospermic and teratospermic individuals.




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Stoichiometry of Nucleotide Binding to Proteasome AAA+ ATPase Hexamer Established by Native Mass Spectrometry [Research]

AAA+ ATPases constitute a large family of proteins that are involved in a plethora of cellular processes including DNA disassembly, protein degradation and protein complex disassembly. They typically form a hexametric ring-shaped structure with six subunits in a (pseudo) 6-fold symmetry. In a subset of AAA+ ATPases that facilitate protein unfolding and degradation, six subunits cooperate to translocate protein substrates through a central pore in the ring. The number and type of nucleotides in an AAA+ ATPase hexamer is inherently linked to the mechanism that underlies cooperation among subunits and couples ATP hydrolysis with substrate translocation. We conducted a native MS study of a monodispersed form of PAN, an archaeal proteasome AAA+ ATPase, to determine the number of nucleotides bound to each hexamer of the WT protein. We utilized ADP and its analogs (TNP-ADP and mant-ADP), and a nonhydrolyzable ATP analog (AMP-PNP) to study nucleotide site occupancy within the PAN hexamer in ADP- and ATP-binding states, respectively. Throughout all experiments we used a Walker A mutant (PANK217A) that is impaired in nucleotide binding as an internal standard to mitigate the effects of residual solvation on mass measurement accuracy and to serve as a reference protein to control for nonspecific nucleotide binding. This approach led to the unambiguous finding that a WT PAN hexamer carried – from expression host – six tightly bound ADP molecules that could be exchanged for ADP and ATP analogs. Although the Walker A mutant did not bind ADP analogs, it did bind AMP-PNP, albeit at multiple stoichiometries. We observed variable levels of hexamer dissociation and an appearance of multimeric species with the over-charged molecular ion distributions across repeated experiments. We posit that these phenomena originated during ESI process at the final stages of ESI droplet evolution.




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Detection of multiple autoantibodies in patients with ankylosing spondylitis using nucleic acid programmable protein arrays [11. Microarrays/Combinatorics/Display Technology]

Ankylosing Spondylitis (AS) is a common, inflammatory rheumatic disease, which primarily affects the axial skeleton and is associated with sacroiliitis, uveitis and enthesitis. Unlike other autoimmune rheumatic diseases, such as rheumatoid arthritis or systemic lupus erythematosus, autoantibodies have not yet been reported to be a feature of AS. We therefore wished to determine if plasma from patients with AS contained autoantibodies and if so, characterize and quantify this response in comparison to patients with Rheumatoid Arthritis (RA) and healthy controls. Two high-density nucleic acid programmable protein arrays expressing a total of 3498 proteins were screened with plasma from 25 patients with AS, 17 with RA and 25 healthy controls. Autoantigens identified were subjected to Ingenuity Pathway Analysis in order to determine patterns of signalling cascades or tissue origin. 44% of patients with Ankylosing Spondylitis demonstrated a broad autoantibody response, as compared to 33% of patients with RA and only 8% of healthy controls. Individuals with AS demonstrated autoantibody responses to shared autoantigens, and 60% of autoantigens identified in the AS cohort were restricted to that group. The AS patients autoantibody responses were targeted towards connective, skeletal and muscular tissue, unlike those of RA patients or healthy controls. Thus, patients with AS show evidence of systemic humoral autoimmunity and multispecific autoantibody production. Nucleic Acid Programmable Protein Arrays constitute a powerful tool to study autoimmune diseases.




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Integrated glycoproteomics identifies a role of N-glycosylation and galectin-1 on myogenesis and muscle development [Research]

Many cell surface and secreted proteins are modified by the covalent addition of glycans that play an important role in the development of multicellular organisms. These glycan modifications enable communication between cells and the extracellular matrix via interactions with specific glycan-binding lectins and the regulation of receptor-mediated signaling. Aberrant protein glycosylation has been associated with the development of several muscular diseases suggesting essential glycan- and lectin-mediated functions in myogenesis and muscle development but our molecular understanding of the precise glycans, catalytic enzymes and lectins involved remain only partially understood. Here, we quantified dynamic remodeling of the membrane-associated proteome during a time-course of myogenesis in cell culture. We observed wide-spread changes in the abundance of several important lectins and enzymes facilitating glycan biosynthesis. Glycomics-based quantification of released N-linked glycans confirmed remodeling of the glycome consistent with the regulation of glycosyltransferases and glycosidases responsible for their formation including a previously unknown di-galactose-to-sialic acid switch supporting a functional role of these glycoepitopes in myogenesis. Furthermore, dynamic quantitative glycoproteomic analysis with multiplexed stable isotope labelling and analysis of enriched glycopeptides with multiple fragmentation approaches identified glycoproteins modified by these regulated glycans including several integrins and growth factor receptors. Myogenesis was also associated with the regulation of several lectins most notably the up-regulation of galectin-1 (LGALS1). CRISPR/Cas9-mediated deletion of Lgals1 inhibited differentiation and myotube formation suggesting an early functional role of galectin-1 in the myogenic program. Importantly, similar changes in N-glycosylation and the up-regulation of galectin-1 during postnatal skeletal muscle development were observed in mice. Treatment of new-born mice with recombinant adeno-associated viruses to overexpress galectin-1 in the musculature resulted in enhanced muscle mass. Our data form a valuable resource to further understand the glycobiology of myogenesis and will aid the development of intervention strategies to promote healthy muscle development or regeneration.




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CIITA-transduced glioblastoma cells uncover a rich repertoire of clinically relevant tumor-associated HLA-II antigens [Research]

CD4+ T cell responses are crucial for inducing and maintaining effective anti-cancer immunity, and the identification of human leukocyte antigen class II (HLA-II) cancer-specific epitopes is key to the development of potent cancer immunotherapies. In many tumor types, and especially in glioblastoma (GBM), HLA-II complexes are hardly ever naturally expressed. Hence, little is known about immunogenic HLA-II epitopes in GBM. With stable expression of the class II major histocompatibility complex transactivator (CIITA) coupled to a detailed and sensitive mass spectrometry based immunopeptidomics analysis, we here uncovered a remarkable breadth of the HLA-ligandome in HROG02, HROG17 and RA GBM cell lines. The effect of CIITA expression on the induction of the HLA-II presentation machinery was striking in each of the three cell lines, and it was significantly higher compared to interferon gamma (IFN) treatment. In total, we identified 16,123 unique HLA-I peptides and 32,690 unique HLA-II peptides. In order to genuinely define the identified peptides as true HLA ligands, we carefully characterized their association with the different HLA allotypes. In addition, we identified 138 and 279 HLA-I and HLA-II ligands, respectively, most of which are novel in GBM, derived from known GBM-associated tumor-antigens that have been used as source proteins for a variety of GBM vaccines. Our data further indicate that CIITA-expressing GBM cells acquired an antigen presenting cell-like phenotype as we found that they directly present external proteins as HLA-II ligands. Not only that CIITA-expressing GBM cells are attractive models for antigen discovery endeavors, but also such engineered cells have great therapeutic potential through massive presentation of a diverse antigenic repertoire.




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On the robustness of graph-based clustering to random network alterations [Research]

Biological functions emerge from complex and dynamic networks of protein-protein interactions. Because these protein-protein interaction networks, or interactomes, represent pairwise connections within a hierarchically organized system, it is often useful to identify higher-order associations embedded within them, such as multi-member protein complexes. Graph-based clustering techniques are widely used to accomplish this goal, and dozens of field-specific and general clustering algorithms exist. However, interactomes can be prone to errors, especially when inferred from high-throughput biochemical assays. Therefore, robustness to network-level noise is an important criterion for any clustering algorithm that aims to generate robust, reproducible clusters. Here, we tested the robustness of a range of graph-based clustering algorithms in the presence of noise, including algorithms common across domains and those specific to protein networks. Strikingly, we found that all of the clustering algorithms tested here markedly amplified noise within the underlying protein interaction network. Randomly rewiring only 1% of network edges yielded more than a 50% change in clustering results, indicating that clustering markedly amplified network-level noise. Moreover, we found the impact of network noise on individual clusters was not uniform: some clusters were consistently robust to injected noise while others were not. To assist in assessing this, we developed the clust.perturb R package and Shiny web application to measure the reproducibility of clusters by randomly perturbing the network. We show that clust.perturb results are predictive of real-world cluster stability: poorly reproducible clusters as identified by clust.perturb are significantly less likely to be reclustered across experiments. We conclude that graph-based clustering amplifies noise in protein interaction networks, but quantifying the robustness of a cluster to network noise can separate stable protein complexes from spurious associations.




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A proteomic approach to understand the clinical significance of acute myeloid leukemia-derived extracellular vesicles reflecting essential characteristics of leukemia [Research]

Extracellular vesicle (EV) proteins from acute myeloid leukemia (AML) cell lines were analyzed using mass spectrometry. The analyses identified 2450 proteins, including 461 differentially expressed proteins (290 upregulated and 171 downregulated). CD53 and CD47 were upregulated and were selected as candidate biomarkers. The association between survival of patients with AML and the expression levels of CD53 and CD47 at diagnosis was analyzed using mRNA expression data from The Cancer Genome Atlas database. Patients with higher expression levels showed significantly inferior survival than those with lower expression levels. Enzyme-linked immunosorbent assay results of the expression levels of CD53 and CD47 from EVs in the bone marrow of patients with AML at diagnosis and at the time of complete remission with induction chemotherapy revealed that patients with downregulated CD53 and CD47 expression appeared to relapse less frequently. Network model analysis of EV proteins revealed several upregulated kinases, including LYN, CSNK2A1, SYK, CSK, and PTK2B. The potential cytotoxicity of several clinically applicable drugs that inhibit these kinases was tested in AML cell lines. The drugs lowered the viability of AML cells. The collective data suggest that AML-derived EVs could reflect essential leukemia biology.




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Ethical principles, opportunities and constraints in clinical proteomics [Research]

Recent advances in MS-based proteomics have vastly increased the quality and scope of biological information that can be derived from human samples. These advances have rendered current workflows increasingly applicable in biomedical and clinical contexts. As proteomics is poised to take an important role in the clinic, associated ethical responsibilities increase in tandem with the impact on the health, privacy, and well-being of individuals. Here we conducted and report a systematic literature review of ethical issues in clinical proteomics. We add our perspectives from a background of bioethics, the results of our accompanying paper extracting individual-sensitive results from patient samples, and the literature addressing similar issues in genomics. The spectrum of potential issues ranges from patient re-identification to incidental findings of clinical significance. The latter can be divided into actionable and unactionable findings. Some of these have the potential to be employed in discriminatory or privacy-infringing ways. However, incidental findings may also have great positive potential. A plasma proteome profile, for instance, could inform on the general health or disease status of an individual regardless of the narrow diagnostic question that prompted it. We suggest that early discussion of ethical issues in clinical proteomics is important to ensure that eventual regulations reflect the considered judgment of the community as well as to anticipate opportunities and problems that may arise as the technology matures further.




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Nuclear Disarmament and the Protection of Cultural Heritage

Nuclear Disarmament and the Protection of Cultural Heritage Research paper sysadmin 6 October 2017

States possessing nuclear weapons should be called upon to consider and publish the risks posed to cultural heritage, and their mitigation strategies, in their nuclear-weapons doctrines and policies.

A woman walks on the roof of the Great Mosque of Djenné, a World Heritage Site, after praying. Photo: United Nations.

Summary

  • Renewed risk assessments for nuclear weapons and policies are taking place around the world in light of nuclear modernization and the changing geostrategic environment that is making the use of nuclear weapons more likely. As such the humanitarian impacts of nuclear weapons and tests have received increased attention. However, the effect on cultural heritage has so far been neglected.
  • The potential for armed conflict to destroy cultural heritage has been recognized in international law since 1954. There is significant evidence on the impact of nuclear weapons on cultural heritage including the consequences of their use in Hiroshima and Nagasaki and the effect of nuclear-testing programmes in places of cultural significance since 1945. States that possess nuclear weapons have increased liabilities and responsibilities to protect cultural heritage and cultural rights. The need to protect cultural heritage should strengthen the case for reducing and eliminating nuclear weapons.
  • Failure to take into account the protection of heritage in the development of nuclear weapons policies – including disarmament, non-proliferation and arms-control negotiations – significantly undermines states’ existing commitments to protecting heritage threatened by conflict.
  • Risk assessments of the impact of nuclear weapons on cultural heritage and important cultural artefacts – and methods of preventing such catastrophic damage – should be part of protecting cultural heritage in every country and the subject of informed public debate. A new body of knowledge on the full range of nuclear weapons impacts would introduce a fresh perspective to inform decision-makers, international organizations and the public in thinking about nuclear weapons policies and practices.
  • Risk and resilience frameworks, which provide sets of solutions for risk assessments, would allow assessments of nuclear weapons threats to heritage and highlight vulnerabilities that need to be addressed. Such frameworks would provide a basis for policymakers to identify the world’s cultural heritage most at risk and help develop mitigation strategies to ensure that it is protected. In particular, states possessing nuclear weapons should be called upon to consider and publish the risks posed to cultural heritage, and their mitigation strategies, in their nuclear weapons doctrines and policies, as a contribution to transparency and confidence-building, and as a responsibility to the world’s shared heritage. International organizations, such as the UN Educational, Scientific, and Cultural Organization (UNESCO), have a role to play in bridging security perspectives with protecting cultural heritage.




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The Role of Sub-state and Non-state Actors in International Climate Processes: Civil Society

The Role of Sub-state and Non-state Actors in International Climate Processes: Civil Society Research paper sysadmin 27 November 2018

Given today’s challenging geopolitical conditions and the evolving nature of the international climate regime since Paris, civil society must now once again recalibrate its strategies to ensure continued and increasing relevance.

Photo by The Climate Reality Project, ‘People’s Climate March Protest’, via Unsplash, 2017.

This is one of four background papers feeding into a synthesis paper entitled The Role of Sub-state and Non-state Actors in International Climate Processes.

Summary

  • Following the failure of the 15th Conference of the Parties (COP 15) in Copenhagen in 2009, there was a step change in the sophistication and unity of civil society engagement on climate policy. This ensured that, subsequently, civil society was more effective in exercising multiple channels of influence around the negotiations for the Paris Agreement in 2015.
  • Civil society proved to be particularly effective at harnessing the twin narratives of climate science and economics, and at leveraging an emerging multi-level governance architecture, to create political space for climate leadership.
  • Given today’s challenging geopolitical conditions and the evolving nature of the international climate regime since Paris, civil society must now once again recalibrate its strategies to ensure continued and increasing relevance.
  • In particular, the shift to a more ‘nationally grounded’ implementation regime focusing on individual states’ climate commitments will require civil society to become more effective at influencing domestic politics. At the same time, civil society will need to continue to seek strategic synergies at the international level.
  • Civil society has a central role to play in ensuring that the first key test of the Paris ‘ratchet’ mechanism – revising countries’ pledged climate actions, or Nationally Determined Contributions (NDCs), by 2020 – is robust, science-informed and strongly rooted in domestic politics.




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The Role of Sub-state and Non-state Actors in International Climate Processes: Corporate Sector

The Role of Sub-state and Non-state Actors in International Climate Processes: Corporate Sector Research paper sysadmin 27 November 2018

Given the challenging political contexts since 2015, the corporate sector will have a key role to play in persuading national governments how technologies and expertise have moved on since the pledges were made.

Photo by Priscilla Du Preez, ‘Climate Reality’ via Unsplash, 2017.

This is one of four background papers feeding into a synthesis paper entitled The Role of Sub-state and Non-state Actors in International Climate Processes.

Summary

  • The corporate sector has traditionally engaged governments at national rather than international level in lobbying for action related to climate change. Where it has engaged at an international level, this has often been to restrain regulation and ambition, such as in air transport. Over time, many businesses have increasingly understood that there is more commercial opportunity in a strong, consistent approach to tackling climate mitigation and adaptation, and an increasing number are willing to speak up on the issue. The Paris Climate Conference in 2015 demonstrated this positive engagement.
  • Businesses are more powerful when engaging directly with national governments on detailed policies – by demonstrating what is possible and indirectly influencing national governments’ international pledges. Traditional trade/industry sector associations and groups have tended to suffer from the ‘lowest common denominator’ effect of their least progressive members. Progressive business groups coalescing around climate ambition can help to counter this.
  • Unlike at the Copenhagen climate talks in 2009, the business community provided a positive, supportive backdrop to the 2015 Paris talks, mindful of the public relations opportunities in taking a progressive stance and of the benefits of targets that reflected the science. The carbon market was a particular focus for corporates, which succeeded in getting emissions trading options and market mechanisms included in Article 6 of the Paris Agreement.
  • Given the challenging political contexts since 2015, the corporate sector will have a key role to play in persuading national governments how technologies and expertise have moved on since the pledges were made. With increasing awareness of resource scarcity, businesses are pursuing ever more creative solutions.
  • Wide recognition that the avoidance of future emissions is increasingly dependent on developing and emerging economies means that business voices from these countries will potentially be more influential in the next few years.




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The Role of Sub-state and Non-state Actors in International Climate Processes

The Role of Sub-state and Non-state Actors in International Climate Processes Research paper sysadmin 27 November 2018

In the current international political environment of rising populism, the role of sub- and non-state actors may become more important than ever.

Photo by UNclimatechange, ‘Bonn Climate Change Conference - October 2014’ via Flickr, 2014.

Summary

  • Climate action from sub-state and non-state actors such as subnational governments, cities, corporations and NGOs has very significant potential to enhance national efforts to curb CO2 emissions, close the so-called ‘emissions gap’ – between current commitments and the action necessary to meet climate targets – and help move the world on to a ‘1.5°C pathway’ that would limit global warming to 1.5°C above pre-industrial levels by 2100.
  • In addition to their own climate action, sub-state/non-state actors can contribute to climate governance by developing new policies and business models to support emissions cuts and build resilience. Knowledge exchange and capacity-building have a role to play in helping these innovations to spread internationally.
  • Politically, measures implemented by sub-state/non-state actors can help national governments to implement existing targets faster and more effectively, while helping to build political support for more ambitious climate action.
  • The post-Paris climate regime of the United Nations Framework Convention on Climate Change (UNFCCC) reflects the growing importance of sub- and non-state actors, and has featured the creation of institutional structures to engage and coordinate them.
  • In the current international political environment of rising populism, the role of sub- and non-state actors may become more important than ever. However, more questions about the robustness of sub- and non-state action are also likely to be raised.
  • With the 2020 deadline approaching for countries to submit details of enhanced Nationally Determined Contributions (NDCs), long-term climate strategies and other means of raising policy ambition, the next two years are set to provide significant opportunity for sub- and non-state action. Many governments are already developing ways to engage with sub- and non-state actors to identify opportunities to strengthen action by 2020.
  • Key questions in this respect include (a) whether sub- and non-state actors can mobilize across sectors; and (b) whether action can be extended beyond the ‘usual suspects’ to include contributions from less familiar sources, such as business sectors with limited opportunities for climate action or corporations in the Global South.




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The Role of Sub-state and Non-state Actors in International Climate Processes: Financial Institutions

The Role of Sub-state and Non-state Actors in International Climate Processes: Financial Institutions Research paper sysadmin 20 December 2018

The trillions of dollars needed to secure the sustainable, climate-compatible pathway outlined in the 2015 Paris Agreement have focused attention on private finance and investment.

Photo by João Barbosa, ‘The need to keep growing’, 2018.

This is one of four background papers feeding into a synthesis paper entitled The Role of Sub-state and Non-state Actors in International Climate Processes.

Summary

  • The trillions of dollars needed to secure the sustainable, climate-compatible pathway outlined in the 2015 Paris Agreement have focused attention on private finance and investment, and on the role of the financial sector as a potentially powerful non-state actor in the international climate debate.
  • Leading individual financial institutions reacted to the Paris Agreement by framing it in terms of what it would mean for markets – i.e. risks and opportunities – and by underlining the importance of national implementation of climate change commitments.
  • Key recent developments signal that the financial sector actively supports Paris-compatible government action on climate change, as well as company-level action to understand the physical and ‘transition’ risks and opportunities associated with climate change and policy responses. Financial sector engagement is taking place through well-organized and well-supported international initiatives and platforms. A critical part of this process entails robust activity by financial institutions to embed climate change and broader sustainability factors into strategies and operations.
  • At country level, attention to implementation of Nationally Determined Contributions (NDCs) and associated sector-level policy development has been largely separate from the broader ‘sustainable finance’ dynamic. National-level action has not benefited from the same level of organized financial sector involvement evident in international action. One of the reasons for this is that, with some notable exceptions, international financial initiatives lack the capacity and resources to participate in the granular detail of national policy processes. Policymakers in turn often lack the internal capacity to consult or engage with the financial sector domestically.
  • This paper includes some thoughts on further international and national climate actions. Ensuring that messages from successful international financial sector initiatives are heard in regional and non-climate forums offers one avenue for building a stronger foundation for greater climate ambition. Building the resource base for stronger national climate policy engagement, as a counter-voice to incumbent interests and to ensure that the quality of policy is ‘investment grade’, is another. This will be critical to the delivery of policy outcomes. Other key elements include the need to pool knowledge across relevant parts of the finance sector, build alliances, and shift action towards joint problem-solving with policymakers. A ‘Talanoa 2.020’-type initiative offers one potentially promising approach to advancing dialogue in this respect.




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The Role of Sub-state and Non-state Actors in International Climate Processes: Subnational Governments

The Role of Sub-state and Non-state Actors in International Climate Processes: Subnational Governments Research paper sysadmin 23 January 2019

This paper looks at the role of subnational governments in influencing global climate ambition, and makes recommendations for how these actors can increase their influence in the future.

Photo by Annie Spratt, ‘High in the SuperTrees’ via Unsplash, 2017

Summary

  • ‘Subnational governments’ – including municipal, regional and provincial authorities – lack the formal status of negotiating parties to the United Nations Framework Convention on Climate Change (UNFCCC). But they have a vital role to play in informing and helping to shape international climate action, as they are often the key delivery partners for on-the-ground policies.
  • Subnational governments are often closer to climate problems than the UNFCCC parties themselves, and have experience, expertise and peer influence that can support the development of progressive policies and increased ambition.
  • Many subnational governments have joined or formed various groupings to share information and experience, and to increase their collective profile and voice. Notable initiatives and collaborations include the Under2 Coalition, ICLEI, C40 and the Global Covenant of Mayors for Climate & Energy.
  • Subnational governments are highly diverse. In some cases, politically high-profile administrations – the US state of California being a notable example – have exploited their visibility and policy successes to engage in wider climate debates. Equally, however, subnational agendas can encounter resistance from national governments anxious to ensure the primacy of their negotiating positions in the UNFCCC system.
  • One of the advantages that subnational governments enjoy, subject to resources, is their ability to join with peer groups to take a fresh approach to mitigation or adaptation policies. Groups of cities or subnational regions can, through collaborative organizations, explore new approaches that might be less attractive within a national context.
  • To maintain and build on their current achievements and influence, subnational governments need, among other things, to: improve the credibility of their experience through evaluation of the success of their climate policies; use membership of appropriate international groups to share experience and boost their leverage; continue to create collaborative relationships with progressive businesses to increase influence at a national level; build on cross-regional relationships in climate adaptation and resilience; and work with other subnational actors to build momentum ahead of the first post-Paris revision of climate commitments in 2020.




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War Time: Temporality and the Decline of Western Military Power

War Time: Temporality and the Decline of Western Military Power Book dora.popova 22 February 2021

In War Time the Western way of war, its pace and timing, are discussed and analysed by experts who question the West’s ability to maintain its military superiority given the political and strategic failures of interventions in Iraq and Afghanistan.

In War Time, war studies experts examine the trajectory of Western military power. They discuss conflicting perceptions of time anchored within Western political and military institutions, and the Western attachment to fast-paced warfare at the expense of longer-term political solutions.

Divided into three sections, the book covers ‘civic militarism’ and the trajectory of Western power, Western perceptions of time and the international normative order, and military operations and temporality. War Time explains why the West has been overwhelmingly powerful on the battlefield and yet strategically and politically weak as exemplified by the return of the Taliban and the hasty evacuation of troops and personnel from Afghanistan.

The book identifies policies that decision-makers must adopt to stave off the decline of Western military dominance.

This book is part of the Insights series.

 

Watch the event

A special event was held in March 2021 to mark the launch of the book. View the event here.

Praise for War Time

War Time is a provocative consideration of the many aspects of modern military power in politics and international affairs. Though the nature of war doesn’t change, this book is particularly relevant given the changing character of modern war as we see in the Caucasus, Ukraine, the Sahel, and the Indo-Pacific region. Essential reading for political leaders, diplomats, and strategic thinkers.

Lt. Gen. (Ret.) Ben Hodges, Pershing Chair in Strategic Studies, Center for European Policy Analysis; Commander, United States Army Europe, 2014–2017

About the editors

Sten Rynning is professor of war studies at the University of Southern Denmark.

Olivier Schmitt is professor with special responsibilities at the Center for War Studies, University of Southern Denmark, and currently director of research and studies at the French Institute for Higher National Defence Studies.

Amelie Theussen is assistant professor at the Center for War Studies, University of 
Southern Denmark.

Purchase




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Mycobacteria excise DNA damage in 12- or 13-nucleotide-long oligomers by prokaryotic-type dual incisions and performs transcription-coupled repair [Genomics and Proteomics]

In nucleotide excision repair, bulky DNA lesions such as UV-induced cyclobutane pyrimidine dimers are removed from the genome by concerted dual incisions bracketing the lesion, followed by gap filling and ligation. So far, two dual-incision patterns have been discovered: the prokaryotic type, which removes the damage in 11–13-nucleotide-long oligomers, and the eukaryotic type, which removes the damage in 24–32-nucleotide-long oligomers. However, a recent study reported that the UvrC protein of Mycobacterium tuberculosis removes damage in a manner analogous to yeast and humans in a 25-mer oligonucleotide arising from incisions at 15 nt from the 3´ end and 9 nt from the 5´ end flanking the damage. To test this model, we used the in vivo excision assay and the excision repair sequencing genome-wide repair mapping method developed in our laboratory to determine the repair pattern and genome-wide repair map of Mycobacterium smegmatis. We find that M. smegmatis, which possesses homologs of the Escherichia coli uvrA, uvrB, and uvrC genes, removes cyclobutane pyrimidine dimers from the genome in a manner identical to the prokaryotic pattern by incising 7 nt 5´ and 3 or 4 nt 3´ to the photoproduct, and performs transcription-coupled repair in a manner similar to E. coli.




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Kinetic investigation of the polymerase and exonuclease activities of human DNA polymerase ϵ holoenzyme [DNA and Chromosomes]

In eukaryotic DNA replication, DNA polymerase ε (Polε) is responsible for leading strand synthesis, whereas DNA polymerases α and δ synthesize the lagging strand. The human Polε (hPolε) holoenzyme is comprised of the catalytic p261 subunit and the noncatalytic p59, p17, and p12 small subunits. So far, the contribution of the noncatalytic subunits to hPolε function is not well understood. Using pre-steady-state kinetic methods, we established a minimal kinetic mechanism for DNA polymerization and editing catalyzed by the hPolε holoenzyme. Compared with the 140-kDa N-terminal catalytic fragment of p261 (p261N), which we kinetically characterized in our earlier studies, the presence of the p261 C-terminal domain (p261C) and the three small subunits increased the DNA binding affinity and the base substitution fidelity. Although the small subunits enhanced correct nucleotide incorporation efficiency, there was a wide range of rate constants when incorporating a correct nucleotide over a single-base mismatch. Surprisingly, the 3'→5' exonuclease activity of the hPolε holoenzyme was significantly slower than that of p261N when editing both matched and mismatched DNA substrates. This suggests that the presence of p261C and the three small subunits regulates the 3'→5' exonuclease activity of the hPolε holoenzyme. Together, the 3'→5' exonuclease activity and the variable mismatch extension activity modulate the overall fidelity of the hPolε holoenzyme by up to 3 orders of magnitude. Thus, the presence of p261C and the three noncatalytic subunits optimizes the dual enzymatic activities of the catalytic p261 subunit and makes the hPolε holoenzyme an efficient and faithful replicative DNA polymerase.




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Reasons for optimism for each MLB club

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.




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Reasons for optimism for each MLB club

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.




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UK confirms first case of clade Ib mpox




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UK reports two further cases of clade Ib mpox




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Higher Education in South Africa: Demands for Inclusion and the Challenges of Reform

Higher Education in South Africa: Demands for Inclusion and the Challenges of Reform 17 October 2018 — 5:00PM TO 6:00PM Anonymous (not verified) 18 September 2018 Chatham House, London

South Africa’s higher education system has come to represent public controversy and intense contestation around the social justice debates that affect the whole of society. The #RhodesMustFall campaign at the University of Cape Town encapsulated national students’ concerns about institutional racism and the slow pace of transformation at all of the country’s universities. The #FeesMustFall movement that emanated from the University of Witwatersrand garnered national support for providing access for poor black students to affordable and high quality education.
South Africa’s universities and government are faced with the challenge of ensuring that all of the country’s citizens have equitable and inclusive access to higher education in a way that protects the institutions as safe spaces for debate, maintains international competitiveness and represents an efficient use of limited available resources.
At this meeting, Professor Adam Habib will reflect on the successes and failures of social protests in South Africa and the challenges they pose for advancing social justice.




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Mine Action in Angola: Clearing the Legacies of Conflict to Harness the Potential of Peace

Mine Action in Angola: Clearing the Legacies of Conflict to Harness the Potential of Peace Other resource sysadmin 14 June 2019

This publication draws on and updates the briefing note published following a meeting of the All- Party Parliamentary Group (APPG) on Angola on 26 April 2017. It also incorporates insights from a Chatham House Africa Programme conference session on the legacies of the Angolan Civil War, held on 23 March 2018; and draws on the Africa Programme’s research into conservation-driven development models in Southern Africa.

A mine clearance specialist in Angola preparing equipment used to look for unexploded ordnance, May 2012. Photo: Eye Ubiquitous/Contributor/Getty Images.

Almost two decades after the end of its civil war, Angola remains one of the most heavily landmine-contaminated countries in the world. The Angolan government has committed to clearing its landmines by 2025, and there is constructive collaboration between the government and mine clearing agencies in this endeavour, but the target will be achievable only if a decline in funding from international donors is reversed. International funding for mine clearance in Angola fell by more than 80 per cent between 2005 and 2017, and this sharp drop in external support has compounded the impact on domestic funding for national clearance efforts as a result of the downturn in prices for Angola’s main export commodities.

The national mine action agency, the Comissão Nacional Intersectorial de Desminagem e Assistência Humanitária (CNIDAH), is supported by the Mines Advisory Group (MAG), Norwegian People’s Aid (NPA) and the HALO Trust. By 2017, 15 years after the end of the civil war, these organizations had collectively helped clear 56 per cent of known landmine-contaminated land. State-led demining has focused principally on clearing areas designated for infrastructure projects. Now, it is critical that humanitarian demining in largely agricultural and conservation areas is prioritized to bring to an end the daily threat to Angola’s rural poor – as well as to the country’s livestock and wildlife – of injury or death as a result of landmine accidents.

Angola has some of the world’s most important remaining wilderness, including the tributary system for the unique Okavango Delta, and the country has the potential to host one of the most diverse wildlife populations on the continent. However, the presence of landmines and other remnants of the civil war render large areas of the country unsafe both for wildlife and for the local people, whose ability to derive a sustainable livelihood from their natural environment is fundamental to its protection.

Wildlife and tourism provide important economic opportunities for diversification beyond an oil-dominated economy. Critically, Angola’s economic diversification and development objectives can only be achieved if the landmines that prohibit access to land for agriculture, mining, tourism and wildlife are cleared.

There are economic opportunities for released land in the most heavily mined provinces of Cuando Cubango and Moxico. Already, some new funding for mine action in Angola, if upscaled or matched by international donors, could be transformative for its people, and for the conservation of the region’s vital biodiversity.




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Zimbabwe Futures 2030: A Vision for Inclusive Long-Term Economic Recovery

Zimbabwe Futures 2030: A Vision for Inclusive Long-Term Economic Recovery 10 October 2019 — 10:00AM TO 12:15PM Anonymous (not verified) 5 September 2019 Harare, Zimbabwe

In its Vision 2030, the government of Zimbabwe committed itself to facilitating an open market and stable economy through strategies such as the Transitional Stabilization Programme (TSP) and new industrialization policy. The private sector is pivotal to these objectives and creating an environment conducive to inclusive and job-creating economic growth. Economic growth can only be achieved with a conducive policy environment and government support to underpin markets with provision of public goods, entrepreneurial incentives and protect contract enforcement and dispute resolution mechanisms.

This event will launch a new Chatham House Africa Programme publication on Zimbabwe’s Vision 2030. The paper is the culmination of an inclusive research process that has drawn on senior private sector expertise, civil society, academics, technocratic elements of government and other experts to develop policy recommendations that will support inclusive economic growth in Zimbabwe.

This event is held in partnership with the Zimbabwe Business Club and Konrad Adenauer Stiftung (KAS). It is supported by KAS and the Dulverton Trust.




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Inclusion, agency and influence: The role of women in Zimbabwe’s economy

Inclusion, agency and influence: The role of women in Zimbabwe’s economy 8 July 2021 — 3:00PM TO 4:30PM Anonymous (not verified) 2 July 2021 Online

Speakers discuss the changing role of women in Zimbabwe’s economic structures and the priorities for promoting greater economic inclusion, agency and influence of women.

Zimbabwe’s National Development Strategy of 2021-2025 highlights the importance of gender sensitivity in policymaking and of women’s economic participation in attaining the government’s Vision 2030.

However, women have been among the worst affected groups by the devastating effects that COVID-19 has had on Zimbabwe’s already floundering economy, which has exacerbated the challenges they face in economic life, such as access to credit, financial services and social security.

Leveraging existing structures such as women’s groups, micro-finance facilities, education and training, and national gender mechanisms, as well as supporting wider financial and digital inclusion in Zimbabwe, is central for the country’s sustained economic recovery.

This event also focuses on the differing impacts of COVID-19 on women’s economic activities across various sectors, as well as along rural-urban and formal-informal economy lines.

Read a meeting summary

This webinar is part of a series of events in partnership with the Konrad Adenauer Stiftung on Zimbabwe’s economic recovery and reform.

This event will also be broadcast live on the Africa Programme Facebook page.




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Endovascular treatment for acute ischaemic stroke in routine clinical practice: prospective, observational cohort study (MR CLEAN Registry)




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Stroke: Take test for genetic variant to ensure clopidogrel works for prevention, says NICE




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NICE recommends hybrid closed loop systems for poorly controlled type 1 diabetes




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Type 1 diabetes: Randox removes adverts after claims that it was using fear to sell genetic test




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Covid-19: Progression to clinical type 1 diabetes accelerated after infection, study suggests




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Patient related outcome measures (PROMs) in long term conditions—is it time to bring them into routine clinical practice?




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The road to COP27: In conversation with US Special Presidential Envoy for Climate John Kerry

The road to COP27: In conversation with US Special Presidential Envoy for Climate John Kerry 27 October 2022 — 3:00PM TO 4:00PM Anonymous (not verified) 20 October 2022 Chatham House and Online

What will progress on climate change look like at COP27?

With global attention zeroing in on COP27, policymakers and world leaders will meet in Egypt to take the next step in the fight against the climate crisis. The planet is on course to warm well beyond 1.5°C and climate hazards are increasing our exposure to climate risk. Violent and unpredictable weather events increasingly leave devastation among communities, particularly in vulnerable countries.

At the same time, the ripple effects of the conflict in Ukraine will have wide-ranging economic, social and geopolitical consequences for years to come. Whilst some finance is being made available, more is needed to properly address the damage caused by climate change and fund the transition to net zero worldwide. These challenges have become more acute as the world grapples with a growing energy crisis, the war in Ukraine and a troubling economic outlook.

Joined by US Special Presidential Envoy for Climate John Kerry, the following questions are considered:

  • Is ‘1.5 degrees’ still on track?

  • How can countries better collaborate to move to net zero faster?

  • How can we achieve progress on adaptation, climate finance, and loss and damage?

As with all members events, questions from the audience drive the conversation.

Read the transcript. 




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A new nuclear order

A new nuclear order 7 February 2023 — 6:00PM TO 7:00PM Anonymous (not verified) 26 January 2023 Chatham House and Online

In conversation with Rafael Mariano Grossi.

For more than half a century, the global nuclear non-proliferation framework has supported international security and facilitated the expansion of the many peaceful applications of nuclear science and technology. 

What is happening today in Ukraine, Iran and North Korea, not only challenges the way we deal with the existential threat of nuclear weapons, but also the impact it could have on addressing another existential threat – climate change.

Russia’s invasion of Ukraine is the biggest test to global resolve both in avoiding nuclear conflict and in ensuring the safety of one of the biggest nuclear power programmes in Europe.

Rafael Mariano Grossi of the International Atomic Energy Agency discusses key questions on global nuclear cooperation including:

  • The impact of the war in Ukraine and issues with Iran and North Korea on countries’ risk assessment with regards to nuclear non-proliferation.

  • What the IAEA’s on-the-ground presence and the director general’s missions to Ukraine, particularly the Zaporizhzhia Nuclear Power Plant, tells us about what is necessary – now and in the long term – to ensure the safety and security of nuclear material under all circumstances.

  • The role of ensuring nuclear energy can play its vital part in mitigating climate change now and in the future.

As with all member events, questions from the audience drive the conversation.

Read the transcript.




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Africa and Europe: Climate security for the future

Africa and Europe: Climate security for the future 20 April 2023 TO 21 April 2023 — 7:30AM TO 12:00PM Anonymous (not verified) 31 March 2023 Slovenia and Online

The 12th Africa Day International Conference hosted in Slovenia offers a platform for interregional exchange and policy cooperation between African and European countries on climate security.

The 12th Africa Day International Conference offers a platform for inter-regional exchange and cooperation to further contribute to progress on climate security.

The 12th Africa Day International Conference is hosted by the Ministry of Foreign and European Affairs of the Republic of Slovenia, in collaboration with the European Commission and the Chatham House Africa Programme. This high-level annual event seeks to improve policy outcomes for citizens in Europe and Africa on the basis of mutual understanding and cooperation between the two regions, while strengthening bilateral relations between Slovenia and African countries.

Climate change poses one of the most serious threats to global security. No individual country or region can face it alone; strong regional and international partnerships are crucial. Analysing risk and taking action can help towards achieving a number of SDGs and a more secure and sustainable future. Addressing climate security is essential for the well-being and future stability of nations and societies around the world, and for the global community as a whole.

This conference will offer a platform for interregional exchange and cooperation on the topic of climate security policy. It will bring together decision-makers and experts from Europe, Africa and across the globe to identify the key challenges and policy priorities in addressing climate security.

The conference will be broadcast live on the Slovenian Ministry of Foreign Affairs webpage, and on the Africa Programme Facebook page.




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[68Ga]Ga-PSMA-11 PET/CT-Positive Hepatic Inflammatory Pseudotumor: Possible PSMA-Avid Pitfall in Nuclear Imaging




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Design, Synthesis, and Preclinical Evaluation of a High-Affinity 18F-Labeled Radioligand for Myocardial Growth Hormone Secretagogue Receptor Before and After Myocardial Infarction

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post–myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics. We designed a high-affinity GHSR ligand labeled with 18F for imaging by PET and characterized its in vivo properties in a canine model of MI. Methods: We rationally designed and radiolabeled with 18F a quinazolinone derivative ([18F]LCE470) with subnanomolar binding affinity to GHSR. We determined the sensitivity and in vivo and ex vivo specificity of [18F]LCE470 in a canine model of surgically induced MI using PET/MRI, which allowed for anatomic localization of tracer uptake and simultaneous determination of global cardiac function. Uptake of [18F]LCE470 was determined by time–activity curve and SUV analysis in 3 regions of the left ventricle—area of infarct, territory served by the left circumflex coronary artery, and remote myocardium—over a period of 1.5 y. Changes in cardiac perfusion were tracked by [13N]NH3 PET. Results: The receptor binding affinity of LCE470 was measured at 0.33 nM, the highest known receptor binding affinity for a radiolabeled GHSR ligand. In vivo blocking studies in healthy hounds and ex vivo blocking studies in myocardial tissue showed the specificity of [18F]LCE470, and sensitivity was demonstrated by a positive correlation between tracer uptake and GHSR abundance. Post-MI changes in [18F]LCE470 uptake occurred independently of perfusion tracer distributions and changes in global cardiac function. We found that the regional distribution of [18F]LCE470 within the left ventricle diverged significantly within 1 d after MI and remained that way throughout the 1.5-y duration of the study. Conclusion: [18F]LCE470 is a high-affinity PET tracer that can detect changes in the regional distribution of myocardial GHSR after MI. In vivo PET molecular imaging of the global dynamics of GHSR may lead to improved GHSR-based therapeutics in the treatment of post-MI remodeling.




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The Emission of Internal Conversion Electrons Rather Than Auger Electrons Increased the Nucleus-Absorbed Dose for 161Tb Compared with 177Lu with a Higher Dose Response for [161Tb]Tb-DOTA-LM3 Than for [161Tb]Tb-DOTATATE

Preclinical data have shown that 161Tb-labeled peptides targeting the somatostatin receptor are therapeutically more effective for peptide receptor radionuclide therapy than are their 177Lu-labeled counterparts. To further substantiate this enhanced therapeutic effect, we performed cellular dosimetry to quantify the absorbed dose to the cell nucleus and compared dose–response curves to evaluate differences in relative biological effectiveness in vitro. Methods: CA20948 cell survival was assessed after treatment with [161Tb]Tb- and [177Lu]Lu-DOTATATE (agonist) and with [161Tb]Tb- and [177Lu]Lu-DOTA-LM3 (antagonist) via a clonogenic assay. Cell binding, internalization, and dissociation assays were performed up to 7 d to acquire time-integrated activity coefficients. Separate S values for each type of particle emission (Auger/internal conversion [IC] electrons and β particles) were computed via Monte Carlo simulations, while considering spheric cells. Once the absorbed dose to the cell nucleus was calculated, survival curves were fitted to the appropriate linear or linear-quadratic model and corresponding relative biological effectiveness was evaluated. Results: Although the radiopeptide uptake was independent of the radionuclide, [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 delivered a 3.6 and 3.8 times higher dose to the nucleus, respectively, than their 177Lu-labeled counterparts on saturated receptor binding. This increased nucleus-absorbed dose was mainly due to the additional emission of IC and not Auger electrons by 161Tb. When activity concentrations were considered, both [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 showed a lower survival fraction than did labeling with 177Lu. When the absorbed dose to the nucleus was considered, no significant difference could be observed between the dose–response curves for [161Tb]Tb- and [177Lu]Lu-DOTATATE. [161Tb]Tb-DOTA-LM3 showed a linear-quadratic dose response, whereas [161Tb]Tb-DOTATATE showed only a linear dose response within the observed dose range, suggesting additional cell membrane damage by Auger electrons. Conclusion: The IC, rather than Auger, electrons emitted by 161Tb resulted in a higher absorbed dose to the cell nucleus and lower clonogenic survival for [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 than for the 177Lu-labeled analogs. In contrast, [161Tb]Tb-DOTATATE showed no higher dose response than [177Lu]Lu-DOTATATE, whereas for [161Tb]Tb-DOTA-LM3 an additional quadratic response was observed. Because of this quadratic response, potentially caused by cell membrane damage, [161Tb]Tb-DOTA-LM3 is a more effective radiopeptide than [161Tb]Tb-DOTATATE for labeling with 161Tb.




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Preclinical Evaluation of 177Lu-OncoFAP-23, a Multivalent FAP-Targeted Radiopharmaceutical Therapeutic for Solid Tumors

Fibroblast activation protein (FAP) is abundantly expressed in the stroma of most human solid tumors. Clinical-stage radiolabeled FAP ligands are increasingly used as tools for the detection of various cancer lesions. To unleash the full therapeutic potential of FAP-targeting agents, ligands need to remain at the tumor site for several days after administration. We recently described the discovery of OncoFAP, a high-affinity small organic ligand of FAP with a rapid accumulation in tumors and low uptake in healthy tissues in cancer patients. Trimerization of OncoFAP provided a derivative (named TriOncoFAP, or OncoFAP-23) with improved FAP affinity. In this work, we evaluated the tissue biodistribution profile and the therapeutic performance of OncoFAP-23 in tumor-bearing mice. Methods: OncoFAP-23 was radiolabeled with the theranostic radionuclide 177Lu. Preclinical experiments were conducted on mice bearing SK-RC-52.hFAP (BALB/c nude mice) or CT-26.hFAP (BALB/c mice) tumors. 177Lu-OncoFAP and 177Lu-FAP-2286 were included in the biodistribution study as controls. Toxicologic evaluation was performed on Wistar rats and CD1 mice by injecting high doses of OncoFAP-23 or its cold-labeled counterpart, respectively. Results: 177Lu-OncoFAP-23 emerged for its best-in-class biodistribution profile, high and prolonged tumor uptake (i.e., ~16 percentage injected dose/g at 96 h), and low accumulation in healthy organs, which correlates well with its potent single-agent anticancer activity at low levels of administered radioactivity. Combination treatment with the tumor-targeted interleukin 2 (L19-IL2, a clinical-stage immunocytokine) further expands the therapeutic window of 177Lu-OncoFAP-23 by potentiating its in vivo antitumor activity. Proteomics studies revealed a potent tumor-directed immune response on treatment with the combination. OncoFAP-23 and natLu-OncoFAP-23 exhibited a favorable toxicologic profile, without showing any side effects or signs of toxicity. Conclusion: OncoFAP-23 presents enhanced tumor uptake and tumor retention and low accumulation in healthy organs, findings that correspond to a strongly improved in vivo antitumor efficacy. The data presented in this work support the clinical development of 177Lu-OncoFAP-23 for the treatment of FAP-positive solid tumors.




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Clinical Factors That Influence Repeat 68Ga-PSMA-11 PET/CT Scan Positivity in Patients with Recurrent Prostate Cancer Under Observation After a Negative 68Ga-PSMA-11 PET/CT Scan: A Single-Center Retrospective Study

This analysis aimed to identify clinical factors associated with positivity on repeat 68Ga-PSMA-11 PET/CT after a negative scan in patients with recurrent prostate cancer (PCa) under observation. Methods: This single-center, retrospective analysis included patients who underwent at least 2 68Ga-PSMA-11 PET/CT scans (PET1 and PET2) at UCLA between October 2016 and June 2021 for recurrent PCa with negative PET1 and no PCa-related treatments between the 2 scans. Using Prostate Cancer Molecular Imaging Standardized Evaluation criteria to define negative and positive scans, the final cohort was divided into PET2-negative (PET2-Neg) and PET2-positive (PET2-Pos). The same PET1 was used twice in the more than 2 PET cases with inclusion criteria fulfilled. Patient characteristics and clinical parameters were compared between the 2 cohorts using Mann–Whitney U test and Fisher exact test. Areas under the curve (AUCs) of the receiver operating characteristic and the Youden index were computed to determine the discrimination ability of statistically significant factors and specific cut points that maximized sensitivity and specificity, respectively. Results: The final analysis included 83 sets of 2 PET/CT scans from 70 patients. Thirty-nine of 83 (47%) sets were PET2-Neg, and 44 of 83 (53%) sets were PET2-Pos. Prostate-specific antigen (PSA) increased from PET1 to PET2 for all 83 (100%) sets of scans. Median PSA at PET1 was 0.4 ng/mL (interquartile range, 0.2–1.0) and at PET2 was 1.6 ng/mL (interquartile range, 0.9–3.8). We found higher serum PSA at PET2 (median, 1.8 vs. 1.1 ng/mL; P = 0.015), absolute PSA difference (median, 1.4 vs. 0.7 ng/mL; P = 0.006), percentage of PSA change (median, +270.4% vs. +150.0%: P = 0.031), and median PSA velocity (0.044 vs. 0.017 ng/mL/wk, P = 0.002) and shorter PSA doubling time (DT; median, 5.1 vs. 8.3 mo; P = 0.006) in the PET2-Pos cohort than in the PET2-Neg cohort. Receiver operating characteristic curves showed cutoffs for PSA at PET2 of 4.80 ng/mL (sensitivity, 34%; specificity, 92%; AUC, 0.66), absolute PSA difference of 0.95 ng/mL (sensitivity, 62%; specificity, 71%; AUC, 0.68), percentage of PSA change of a positive 289.50% (sensitivity, 48%; specificity, 82%; AUC, 0.64), PSA velocity of 0.033 ng/mL/wk (sensitivity, 57%; specificity, 80%; AUC, 0.70), and PSA DT of 7.91 mo (sensitivity, 71%; specificity, 62%; AUC, 0.67). Conclusion: Patients with recurrent PCa under observation after a negative 68Ga-PSMA-11 PET/CT scan with markedly elevated serum PSA levels and shorter PSA DT are more likely to have positive findings on repeat 68Ga-PSMA-11 PET/CT.




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Nuclear Imaging of Bispecific Antibodies on the Rise

Bispecific antibodies (bsAbs) are engineered to target 2 different epitopes simultaneously. About 75% of the 16 clinically approved bsAbs have entered the clinic internationally since 2022. Hence, research on biomedical imaging of various radiolabeled bsAb scaffolds may serve to improve patient selection for bsAb therapy. Here, we provide a comprehensive overview of recent advances in radiolabeled bsAbs for imaging via PET or SPECT. We compare direct targeting and pretargeting approaches in preclinical and clinical studies in oncologic research. Furthermore, we show preclinical applications of imaging bsAbs in neurodegenerative diseases. Finally, we offer perspectives on the future directions of imaging bsAbs based on their challenges and opportunities.




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U.S., South Korea agree to greater cooperation on civil nuclear energy

Earlier this month, the United States and the Republic of Korea reached an agreement on greater cooperation on civil nuclear energy projects, the U.S. Department of Energy said this week.




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Supreme Court questions risk disclosure arguments in Facebook case

The Supreme Court appeared skeptical that companies should be required to include past events in their risk disclosure statements during oral arguments for Facebook Inc. vs. Amalgamated Bank on Wednesday.




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Starmer, Macron reaffirm 'ironclad' support for Ukraine amid uncertainty around Trump

French President Emmanuel Macron was joined in Paris on Monday by British Prime Minister Keir Starmer for Armistice Day commemorations after a meeting at which both leaders reaffirmed "unwavering" support for Ukraine.




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At least 56 people, including 20 children, killed in Israeli airstrikes in Lebanon and Gaza

Dozens of people were killed in Israeli military strikes on northern Lebanon and the Gaza strip, including as many as 20 children, authorities said.




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PNNL-Microsoft Collaborate on Cloud Computing for Chemistry, More to Come

RICHLAND, Wash.—Some computing challenges are so big that it’s necessary to go all in. That’s the approach a diverse team of scientists and computing experts led by the Department of Energy’s […]

The post PNNL-Microsoft Collaborate on Cloud Computing for Chemistry, More to Come appeared first on HPCwire.



  • Features
  • Pacific Northwest National Laboratory

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Google Cloud and Oracle Veteran Amit Zavery to Spearhead Product and Engineering at ServiceNow

SANTA CLARA, Calif., Oct. 25, 2024 — ServiceNow has announced that enterprise software industry veteran Amit Zavery will join the company as president, chief product officer (CPO), and chief operating officer […]

The post Google Cloud and Oracle Veteran Amit Zavery to Spearhead Product and Engineering at ServiceNow appeared first on HPCwire.