Chatham House welcomes 2022 interns News release jon.wallace 11 May 2022

Internships provide learning opportunities about shaping policy, influencing debate and creating real change.

Chatham House is excited to welcome the second cohort to the Molchanov Sustainability Internship Programme.

Introduced in January 2021, the programme has been made possible following the gift of Pavel Molchanov, to support the next generation of leaders in sustainability.

The internships grant invaluable, practical learning opportunities about shaping policy, influencing debate and creating real change towards a sustainable future.

Alis Martin, Internships and Outreach Manager at Chatham House, said:

‘We are delighted to welcome the second cohort to the Molchanov Sustainability Internship Programme. This cohort brings a diversity of new and invaluable perspectives and ideas to the work of our programmes.

‘Over the course of 12 weeks, interns will be working alongside internationally respected experts in Chatham House programmes, exploring issues of sustainability through the lenses of climate change, the circular economy, conflict prevention, emerging technology, global health, governance, human rights, security policy, sustainable cities and sustainable finance.

‘Fostering sustainable and equitable growth and engaging the next generation of policy leaders is central to Chatham House’s vision. We are committed to providing the best experience and opportunities to our interns who share an interest in pursuing a career in the field of sustainability.

‘It is crucial that we incorporate the views and knowledge of those who will be affected most in the future and I very much look forward to seeing the innovative and impactful ideas that will undoubtedly result from their work.’

Mr Molchanov said:

‘Recent headlines around the world underscore the importance of taking the broadest possible perspective on sustainability. Energy supply concerns, rising food prices, and continued pandemic pressure are all interconnected with climate issues. I look forward to hearing about the work in which this year’s internship participants engage.’

Jerome Puri, intern, Middle East and North Africa Programme, said:

‘I applied for this internship to gain a holistic insight into the coordination of a policy institute and to understand how Chatham House promotes international cooperation and accountable governance around the world.  Chatham House offers an unparalleled opportunity to contribute to projects on frontier issues facing the MENA region and develop a diverse range of skills ranging from project management and communications to policy-oriented research skills.’

Obioma Egemonye, intern, Africa Programme, said:

‘I was particularly interested in joining the Africa Programme at Chatham House after learning an immeasurable amount from their work on the Social Norms and Accountable Governance (SNAG) research for my undergraduate dissertation. I am most looking forward to attending the variety of events held by Chatham House and the Africa programme specifically.’

Valdone Sniukaite, intern, Europe Programme, said:

‘I am excited to be joining the Europe Programme team and getting exposure to the inner workings of a policy and research think tank. I’m mostly looking forward to building my organizational skill set by working on the Belvedere Forum and using the opportunity of being around experts in the field of international affairs to broaden my knowledge.’

Lucile de Laforcade, intern, Queen Elizabeth II Academy for Leadership in International Affairs, said:

‘As part of the Academy, I am able to work at the crossroads of research, leadership, international affairs and personal development. This makes the Academy a place of constant challenge to find innovative, sustainable solutions, and emulate new ideas. As an aspiring academic, this is particularly empowering! I am hoping to gain new skills, further develop independent thinking, and cultivate my own research interests in the vibrant environment of a leading policy institute.’

Katie McCann, intern, Communications and Publishing, said:

‘I’m really interested in youth engagement in international politics so I’m very excited to be working on the Common Futures Conversations platform which brings young people across Europe and Africa into the debate on the pressing global issues of our time. I hope my time at Chatham House will expose me to people of different backgrounds and beliefs which will encourage me to engage even more critically with international affairs.’

Rachael Mullally, intern, International Law Programme, said:

‘What I admire most about the International Law Programme here is its position as a dependable yet experimental source on global governance debates. I am especially excited to get working on the Human Rights Pathways Project, focusing on tangible ideas as to how the human rights framework can evolve to meet power shifts between states and non-state actors.’

Elia Duran-Smith, intern, International Security Programme, said:

‘I was particularly drawn to this internship because of the thematic focuses of the programme around nuclear security and emerging technologies in the sector, which are fundamental to understanding the future of the global security environment. I am looking forward to learning more about these topics while developing and expanding my research and writing skills, as well as gaining an understanding of project management and how Chatham House engages with stakeholders on policy.’

Rory Selvey, intern, Sustainability Accelerator, said:

‘For me, speeding up the transition towards a fairer, low-carbon society is one of most important global challenges. I’m really excited to be an intern at the Sustainability Accelerator, collaborating with different teams and exploring innovation solutions to this challenge. Chatham House will help me develop vital knowledge and skills, acting as a fantastic springboard for a potential career in sustainable finance, macroeconomics, or international development.’

Bruna Miguel, intern, Environment and Society Programme, said:

‘Being an intern in the Environment and Society Programme will give me the opportunity to further investigate how these issues relate and how we can achieve true sustainability. I look forward to learning from the experts in the area that I will meet (and hopefully find a dissertation topic!).’

Ritvij Singh, intern, Global Health Programme, said:

‘My view of healthcare delivery is from the frontlines as a medical doctor. I applied to this internship to widen my perspective and get an insight into the institutions that will help facilitate universal health. I will use this experience to pursue a career in global health.’

For more information about the internships, please contact Alis Martin.

Daniel A. Goldston, Apoorva Panidapu and Jordan Schettler
Math. Comp. 93 (), 2943-2958.
Abstract, references and article information

Stromal interaction molecule 1 (STIM1) plays a pivotal role in store-operated Ca2+ entry (SOCE), an essential mechanism in cellular calcium signaling and in maintaining cellular calcium balance. Because O-GlcNAcylation plays pivotal roles in various cellular function, we examined the effect of fluctuation in STIM1 O-GlcNAcylation on SOCE activity. We found that both increase and decrease in STIM1 O-GlcNAcylation impaired SOCE activity. To determine the molecular basis, we established STIM1-knockout HEK293 (STIM1-KO-HEK) cells using the CRISPR/Cas9 system and transfected STIM1 WT (STIM1-KO-WT-HEK), S621A (STIM1-KO-S621A-HEK), or T626A (STIM1-KO-T626A-HEK) cells. Using these cells, we examined the possible O-GlcNAcylation sites of STIM1 to determine whether the sites were O-GlcNAcylated. Co-immunoprecipitation analysis revealed that Ser621 and Thr626 were O-GlcNAcylated and that Thr626 was O-GlcNAcylated in the steady state but Ser621 was not. The SOCE activity in STIM1-KO-S621A-HEK and STIM1-KO-T626A-HEK cells was lower than that in STIM1-KO-WT-HEK cells because of reduced phosphorylation at Ser621. Treatment with the O-GlcNAcase inhibitor Thiamet G or O-GlcNAc transferase (OGT) transfection, which increases O-GlcNAcylation, reduced SOCE activity, whereas treatment with the OGT inhibitor ST045849 or siOGT transfection, which decreases O-GlcNAcylation, also reduced SOCE activity. Decrease in SOCE activity due to increase and decrease in O-GlcNAcylation was attributable to reduced phosphorylation at Ser621. These data suggest that both decrease in O-GlcNAcylation at Thr626 and increase in O-GlcNAcylation at Ser621 in STIM1 lead to impairment of SOCE activity through decrease in Ser621 phosphorylation. Targeting STIM1 O-GlcNAcylation could provide a promising treatment option for the related diseases, such as neurodegenerative diseases.

Abnormal changes of neuronal Tau protein, such as phosphorylation and aggregation, are considered hallmarks of cognitive deficits in Alzheimer's disease. Abnormal phosphorylation is thought to precede aggregation and therefore to promote aggregation, but the nature and extent of phosphorylation remain ill-defined. Tau contains ∼85 potential phosphorylation sites, which can be phosphorylated by various kinases because the unfolded structure of Tau makes them accessible. However, methodological limitations (e.g. in MS of phosphopeptides, or antibodies against phosphoepitopes) led to conflicting results regarding the extent of Tau phosphorylation in cells. Here we present results from a new approach based on native MS of intact Tau expressed in eukaryotic cells (Sf9). The extent of phosphorylation is heterogeneous, up to ∼20 phosphates per molecule distributed over 51 sites. The medium phosphorylated fraction Pm showed overall occupancies of ∼8 Pi (± 5) with a bell-shaped distribution; the highly phosphorylated fraction Ph had 14 Pi (± 6). The distribution of sites was highly asymmetric (with 71% of all P-sites in the C-terminal half of Tau). All sites were on Ser or Thr residues, but none were on Tyr. Other known posttranslational modifications were near or below our detection limit (e.g. acetylation, ubiquitination). These findings suggest that normal cellular Tau shows a remarkably high extent of phosphorylation, whereas other modifications are nearly absent. This implies that abnormal phosphorylations at certain sites may not affect the extent of phosphorylation significantly and do not represent hyperphosphorylation. By implication, the pathological aggregation of Tau is not likely a consequence of high phosphorylation.

Simone Kurz
Dec 29, 2020; 0:RA120.002266v1-mcp.RA120.002266
Research

Peter Lasch
Dec 1, 2020; 19:2125-2138
Technological Innovation and Resources

Julia Knöckel
Dec 22, 2020; 0:RA120.002432v1-mcp.RA120.002432
Research

Jianhua Wang
Nov 4, 2020; 0:RA120.002375v1-mcp.RA120.002375
Research

Martin Prescher
Dec 1, 2020; 61:1605-1616
Research Articles

Chiara Pavanello
Dec 1, 2020; 61:1784-1788
Patient-Oriented and Epidemiological Research

Junhwan Kim
Dec 1, 2020; 61:1707-1719
Research Articles

Thibaut Bourgeois
Dec 11, 2020; 0:jlr.RA120000737v1-jlr.RA120000737
Research Articles

Tommaso Laurenzi
Dec 2, 2020; 0:jlr.RA120000843v1-jlr.RA120000843
Research Articles

In SAS Customer Intelligence Studio, you might notice that the user interface becomes unresponsive, as shown below: imgalt="SAS Customer Intelligence Studio UI becomes unresponsive" src="{fusion_66537

In SAS Customer Intelligence Studio, you can choose to create a new calculated variable in the Edit Value dialog box when you populate a treatment custom detail. Following creation of the new calculated

This manuscript has been withdrawn by the Author.

Lecithin:cholesterol-acyl-transferase (LCAT) plays a major role in cholesterol metabolism as it is the only extracellular enzyme able to esterify cholesterol. LCAT activity is required for lipoprotein remodelling and, most specifically, for the growth and maturation of HDLs. In fact, genetic alterations affecting LCAT func- tionality may cause a severe reduction in plasma levels of HDL-cholesterol with important clinical consequences. Although several hypotheses were formulated, the exact molecular recognition mechanism between LCAT and HDLs is still unknown. We employed a combination of structural bioinformatics procedures to deepen the insights into the HDL-LCAT interplay that promotes LCAT activation and cholesterol esterification. We have generated a data-driven model of reconstituted HDL (rHDL) and studied the dynamics of an assembled rHDL::LCAT supramolecular complex, pinpointing the conformational changes originating from the interaction between LCAT and apolipoprotein A-I (apoA-I) that are necessary for LCAT activation. Specifically, we propose a mechanism in which the anchoring of LCAT lid to apoA-I helices allows the formation of a hydrophobic hood that expands LCAT active site and shields it from the solvent, allowing the enzyme to process large hydrophobic substrates.

Recent studies have highlighted an important role for lysophosphatidylcholine acyltransferase 3 (LPCAT3) in controlling the PUFA composition of cell membranes in the liver and intestine. In these organs, LPCAT3 critically supports cell membrane-associated processes such as lipid absorption or lipoprotein secretion. However, the role of LPCAT3 in macrophages remains controversial. Here, we investigated LPCAT3’s role in macrophages both in vitro and in vivo in mice with atherosclerosis and obesity. To accomplish this, we used the LysMCre strategy to develop a mouse model with conditional Lpcat3 deficiency in myeloid cells (Lpcat3KOMac). We observed that partial Lpcat3 deficiency (approx. 75% reduction) in macrophages alters the PUFA composition of all phospholipid (PL) subclasses, including phosphatidylinositols and phosphatidylserines. A reduced incorporation of C20 PUFAs (mainly arachidonic acid [AA]) into PLs was associated with a redistribution of these FAs toward other cellular lipids such as cholesteryl esters. Lpcat3 deficiency had no obvious impact on macrophage inflammatory response or endoplasmic reticulum (ER) stress; however, Lpcat3KOMac macrophages exhibited a reduction in cholesterol efflux in vitro. In vivo, myeloid Lpcat3 deficiency did not affect atherosclerosis development in LDL receptor deficient mouse (Ldlr-/-) mice. Lpcat3KOMac mice on a high-fat diet displayed a mild increase in hepatic steatosis associated with alterations in several liver metabolic pathways and in liver eicosanoid composition. We conclude that alterations in AA metabolism along with myeloid Lpcat3 deficiency may secondarily affect AA homeostasis in the whole liver, leading to metabolic disorders and triglyceride accumulation.

The acyltransferase LCAT mediates FA esterification of plasma cholesterol. In vitro studies have shown that LCAT also FA-esterifies several oxysterols, but in vivo evidence is lacking. Here, we measured both free and FA-esterified forms of sterols in 206 healthy volunteers and 8 individuals with genetic LCAT deficiency, including familial LCAT deficiency (FLD) and fish-eye disease (FED). In the healthy volunteers, the mean values of the ester-to-total molar ratios of the following sterols varied: 4β-hydroxycholesterol (4βHC), 0.38; 5,6α-epoxycholesterol (5,6αEC), 0.46; 5,6β-epoxycholesterol (5,6βEC), 0.51; cholesterol, 0.70; cholestane-3β,5α,6β-triol (CT), 0.70; 7-ketocholesterol (7KC), 0.75; 24S-hydroxycholesterol (24SHC), 0.80; 25-hydroxycholesterol (25HC), 0.81; 27-hydroxycholesterol (27HC), 0.86; and 7α-hydroxycholesterol (7αHC), 0.89. In the individuals with LCAT deficiency, the plasma levels of the FA-esterified forms of cholesterol, 5,6αEC, 5,6βEC, CT, 7αHC, 7KC, 24SHC, 25HC, and 27HC, were significantly lower than those in the healthy volunteers. The individuals with FLD had significantly lower FA-esterified forms of 7αHC, 24SHC, and 27HC than those with FED. It is of note that, even in the three FLD individuals with negligible plasma cholesteryl ester, substantial amounts of the FA-esterified forms of 4βHC, 5,6αEC, 7αHC, 7KC, and 27HC were present. We conclude that LCAT has a major role in the FA esterification of many plasma oxysterols but contributes little to the FA esterification of 4βHC. Substantial FA esterification of 4βHC, 5,6αEC, 7αHC, 7KC, and 27HC is independent of LCAT.

Sphingolipids have become established participants in the pathogenesis of obesity and its associated maladies. Sphingosine kinase 1 (SPHK1), which generates S1P, has been shown to increase in liver and adipose of obese humans and mice and to regulate inflammation in hepatocytes and adipose tissue, insulin resistance, and systemic inflammation in mouse models of obesity. Previous studies by us and others have demonstrated that global sphingosine kinase 1 KO mice are protected from diet-induced obesity, insulin resistance, systemic inflammation, and NAFLD, suggesting that SPHK1 may mediate pathological outcomes of obesity. As adipose tissue dysfunction has gained recognition as a central instigator of obesity-induced metabolic disease, we hypothesized that SPHK1 intrinsic to adipocytes may contribute to HFD-induced metabolic pathology. To test this, we depleted Sphk1 from adipocytes in mice (SK1^fatKO) and placed them on a HFD. In contrast to our initial hypothesis, SK1^fatKO mice displayed greater weight gain on HFD and exacerbated impairment in glucose clearance. Pro-inflammatory cytokines and neutrophil content of adipose tissue were similar, as were levels of circulating leptin and adiponectin. However, SPHK1-null adipocytes were hypertrophied and had lower basal lipolytic activity. Interestingly, hepatocyte triacylglycerol accumulation and expression of pro-inflammatory cytokines and collagen 1a1 were exacerbated in SK1^fatKO mice on a HFD, implicating a specific role for adipocyte SPHK1 in adipocyte function and inter-organ cross-talk that maintains overall metabolic homeostasis in obesity. Thus, SPHK1 serves a previously unidentified essential homeostatic role in adipocytes that protects from obesity-associated pathology. These findings may have implications for pharmacological targeting of the SPHK1/S1P signaling axis.

Familial LCAT deficiency (FLD) is a rare genetic disorder of HDL metabolism, caused by loss-of-function mutations in the LCAT gene and characterized by a variety of symptoms including corneal opacities and kidney failure. Renal disease represents the leading cause of morbidity and mortality in FLD cases. However, the prognosis is not known and the rate of deterioration of kidney function is variable and unpredictable from patient to patient. In this article, we present data from a follow-up of the large Italian cohort of FLD patients, who have been followed for an average of 12 years. We show that renal failure occurs at the median age of 46 years, with a median time to a second recurrence of 10 years. Additionally, we identify high plasma unesterified cholesterol level as a predicting factor for rapid deterioration of kidney function. In conclusion, this study highlights the severe consequences of FLD, underlines the need of correct early diagnosis and referral of patients to specialized centers, and highlights the urgency for effective treatments to prevent or slow renal disease in patients with LCAT deficiency.

Phospholipids, including ether phospholipids, are composed of numerous isomeric and isobaric species that have the same backbone and acyl chains. This structural resemblance results in similar fragmentation patterns by collision-induced dissociation of phospholipids regardless of class, yielding complicated MS/MS spectra when isobaric species are analyzed together. Furthermore, the presence of isobaric species can lead to misassignment of species when made solely based on their molecular weights. In this study, we used normal-phase HPLC for ESI-MS/MS analysis of phospholipids from bovine heart mitochondria. Class separation by HPLC eliminates chances for misidentification of isobaric species from different classes of phospholipids. Chromatography yields simple MS/MS spectra without interference from isobaric species, allowing clear identification of peaks corresponding to fragmented ions containing monoacylglycerol backbone derived from losing one acyl chain. Using these fragmented ions, we characterized individual and isomeric species in each class of mitochondrial phospholipids, including unusual species, such as PS, containing an ether linkage and species containing odd-numbered acyl chains in cardiolipin, PS, PI, and PG. We also characterized monolysocardiolipin and dilysocardiolipin, the least abundant but nevertheless important mitochondrial phospholipids. The results clearly show the power of HPLC-MS/MS for identification and characterization of phospholipids, including minor species.

ABCB4/MDR3 is located in the canalicular membrane of hepatocytes and translocates PC-lipids from the cytoplasmic to the extracellular leaflet. ABCB4 is an ATP-dependent transporter that reduces the harsh detergent effect of the bile salts by counteracting self-digestion. To do so, ABCB4 provides PC lipids for extraction into bile. PC lipids account for 40% of the entire pool of lipids in the canalicular membrane with an unknown distribution over both leaflets. Extracted PC lipids end up in so-called mixed micelles. Mixed micelles are composed of phospholipids, bile salts, and cholesterol. Ninety to ninety-five percent of the phospholipids are members of the PC family, but only a subset of mainly 16.0-18:1 PC and 16:0-18:2 PC variants are present. To elucidate whether ABCB4 is the key discriminator in this enrichment of specific PC lipids, we used in vitro studies to identify crucial determinants in substrate selection. We demonstrate that PC-lipid moieties alone are insufficient for stimulating ABCB4 ATPase activity, and that at least two acyl chains and the backbone itself are required for a productive interaction. The nature of the fatty acids, like length or saturation has a quantitative impact on the ATPase activity. Our data demonstrate a two-step enrichment and protective function of ABCB4 to mitigate the harsh detergent effect of the bile salts, because ABCB4 can translocate more than just the PC-lipid variants found in bile.

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.

Over the past decade, modern methods of MS (MS) have emerged that allow reliable, fast and cost-effective identification of pathogenic microorganisms. Although MALDI-TOF MS has already revolutionized the way microorganisms are identified, recent years have witnessed also substantial progress in the development of liquid chromatography (LC)-MS based proteomics for microbiological applications. For example, LC-tandem MS (LC-MS²) has been proposed for microbial characterization by means of multiple discriminative peptides that enable identification at the species, or sometimes at the strain level. However, such investigations can be laborious and time-consuming, especially if the experimental LC-MS² data are tested against sequence databases covering a broad panel of different microbiological taxa. In this proof of concept study, we present an alternative bottom-up proteomics method for microbial identification. The proposed approach involves efficient extraction of proteins from cultivated microbial cells, digestion by trypsin and LC–MS measurements. Peptide masses are then extracted from MS¹ data and systematically tested against an in silico library of all possible peptide mass data compiled in-house. The library has been computed from the UniProt Knowledgebase covering Swiss-Prot and TrEMBL databases and comprises more than 12,000 strain-specific in silico profiles, each containing tens of thousands of peptide mass entries. Identification analysis involves computation of score values derived from correlation coefficients between experimental and strain-specific in silico peptide mass profiles and compilation of score ranking lists. The taxonomic positions of the microbial samples are then determined by using the best-matching database entries. The suggested method is computationally efficient – less than 2 mins per sample - and has been successfully tested by a test set of 39 LC-MS¹ peak lists obtained from 19 different microbial pathogens. The proposed method is rapid, simple and automatable and we foresee wide application potential for future microbiological applications.

Complex protein glycosylation occurs through biosynthetic steps in the secretory pathway that create macro- and microheterogeneity of structure and function.  Required for all life forms, glycosylation diversifies and adapts protein interactions with binding partners that underpin interactions at cell surfaces and pericellular and extracellular environments. Because these biological effects arise from heterogeneity of structure and function, it is necessary to measure their changes as part of the quest to understand nature.  Quite often, however, the assumption behind proteomics that post-translational modifications are discrete additions that can be modeled using the genome as a template does not apply to protein glycosylation.  Rather, it is necessary to quantify the glycosylation distribution at each glycosite and to aggregate this information into a population of mature glycoproteins that exist in a given biological system.  To date, mass spectrometric methods for assigning singly glycosylated peptides are well-established.  But it is necessary to quantify glycosylation heterogeneity accurately in order to gauge the alterations that occur during biological processes.  The task is to quantify the glycosylated peptide forms as accurately as possible and then apply appropriate bioinformatics algorithms to the calculation of micro- and macro-similarities.  In this review, we summarize current approaches for protein quantification as they apply to this glycoprotein similarity problem.

Malaria elimination is still pending on the development of novel tools that rely on a deep understanding of parasite biology. Proteins of all living cells undergo a myriad number of posttranslational modifications (PTMs) that are critical to multifarious life processes. An extensive proteome-wide dissection revealed a fine PTM map of most proteins in both Plasmodium falciparum, the causative agent of severe malaria, and the infected red blood cells. More than two-thirds of proteins of the parasite and its host cell underwent extensive and dynamic modification throughout the erythrocytic developmental stage. PTMs critically modulate the virulence factors involved in the host-parasite interaction and pathogenesis. Furthermore, P. falciparum stabilized the supporting proteins of erythrocyte origin by selective de-modification. Collectively, our multiple omic analyses, apart from having furthered a deep understanding of the systems biology of P. falciparum and malaria pathogenesis, provide a valuable resource for mining new antimalarial targets.

Sporozoites are a motile form of malaria-causing Plasmodium falciparum parasites that migrate from the site of transmission in the dermis through the bloodstream to invade hepatocytes. Sporozoites interact with many cells within the host, but the molecular identity of these interactions and their role in the pathology of malaria is poorly understood. Parasite proteins that are secreted and embedded within membranes are known to be important for these interactions, but our understanding of how they interact with each other to form functional complexes is largely unknown. Here, we compile a library of recombinant proteins representing the repertoire of cell surface and secreted proteins from the P. falciparum sporozoite and use an assay designed to detect extracellular interactions to systematically identify complexes. We identify three protein complexes including an interaction between two components of the p24 complex that is involved in the trafficking of glycosylphosphatidylinositol (GPI)-anchored proteins through the secretory pathway. Plasmodium parasites lacking either gene are strongly inhibited in the establishment of liver stage infections. These findings reveal an important role for the p24 complex in malaria pathogenesis and show that the library of recombinant proteins represents a valuable resource to investigate P. falciparum sporozoite biology.

High performance liquid chromatography has been employed for decades to enhance detection sensitivity and quantification of complex analytes within biological mixtures. Among these analytes, glycans released from glycoproteins and glycolipids have been characterized as underivatized or fluorescently tagged derivatives by HPLC coupled to various detection methods. These approaches have proven extremely useful for profiling the structural diversity of glycoprotein and glycolipid glycosylation but require the availability of glycan standards and secondary orthogonal degradation strategies to validate structural assignments. A robust method for HPLC separation of glycans as their permethylated derivatives, coupled with in-line MSn fragmentation to assign structural features independent of standards, would significantly enhance the depth of knowledge obtainable from biological samples. Here, we report an optimized workflow for LC-MS analysis of permethylated glycans that includes sample preparation, mobile phase optimization, and MSn method development to resolve structural isomers on-the-fly. We report baseline separation and MSn fragmentation of isomeric N- and O-glycan structures, aided by supplementing mobile phases with Li+, which simplifies adduct heterogeneity and facilitates cross-ring fragmentation to obtain valuable monosaccharide linkage information. Our workflow has been adapted from standard proteomics-based workflows and, therefore, provides opportunities for laboratories with expertise in proteomics to acquire glycomic data with minimal deviation from existing buffer systems, chromatography media, and instrument configurations. Furthermore, our workflow does not require a mass spectrometer with high-resolution/accurate mass capabilities. The rapidly evolving appreciation of the biological significance of glycans for human health and disease requires the implementation of high-throughput methods to identify and quantify glycans harvested from sample sets of sufficient size to achieve appropriately powered statistical significance. The LC-MSn approach we report generates glycan isomeric separations, robust structural characterization, and is amenable to auto-sampling with associated throughput enhancements.

Afonso Dhlakama’s Death Changes the Calculation for Peace Prospects in Mozambique Expert comment sysadmin 4 May 2018

If politicians continue to act in good faith, the death of the opposition leader may be a significant opportunity to finally draw a line under Mozambique’s long war.

The unexpected death of opposition and ex-rebel leader Afonso Dhlakama on 3 May is a game changer for Mozambique’s politics and an almost-completed peace process. The 65-year old Dhlakama, who died of a heart attack, had led Renamo for 38 years and had totally dominated his party. Dhlakama regularly boasted that he was Mozambique’s ‘father of democracy’, despite not allowing competition within his own party, and he leaves a legacy of more than 30 years of struggle, through both armed action and peaceful politics.

A long war

Originally Renamo had been a tool for the white minority regimes of Rhodesia and apartheid South Africa to challenge the socialist Frelimo political party that took power in Mozambique in 1975. But under Dhlakama’s command, by the late 1980s Renamo had become increasingly independent and rooted in Mozambique. After Renamo’s long war with Frelimo ground to a hurting stalemate, a transition led to Mozambique’s first multiparty elections in 1994, and the creation of a new joint army. A ‘pay and scatter’ programme successfully dispersed and reintegrated many thousands of ex-combatants.

But early post-election gains did not translate to lasting peace. Disarmament was a time-limited, technical process, and devoted declining resources and attention to clusters of ex-combatants that failed to disperse. In addition, Dhlakama was allowed to maintain an armed militia under the guise of a presidential guard.

Mounting economic inequality, notably in opposition strongholds such as central Mozambique, saw Renamo made political gains and Dhlakama nearly won the 1999 presidential elections. (Some believe he did.) The result focused Frelimo’s attention on the threat that Renamo posed and, ultimately, a strategy of pursuing total Frelimo domination across the country, culminating in a crushing Frelimo victory at the 2009 elections.

This humiliated and marginalized former Renamo rebels, resulting in Dhlakama ordering their return to targeted armed violence in 2013. Frelimo’s new leader, President Filipe Nyusi, took power in 2015 and sought direct dialogue with Dhlakama. Five rounds of internationally mediated peace talks took place from July to December. Finally, in late December 2016, Dhlakama announced a unilateral truce, which was extended twice and subsequently made indefinite.

New peace talks also started and, in August 2017 and February 2018, President Nyusi and Dhlakama showed the courage to meet in person, near Renamo’s base in central Mozambique, to build up mutual trust and discuss the details of the emerging peace deal – including the demobilization or integration into government security forces for Renamo’s now mostly middle-aged gunmen.

Dhlakama the ‘Big Man’

Dhlakama’s sudden death has fundamentally changed the negotiation dynamics. He never allowed for any serious succession planning, and ensured all key decisions were his and his alone. Renamo had already decided that he would be its presidential candidate for the 2019 national elections.

His party is significantly weakened by his death and unlikely able to fully recover – but needs to try and reach consensus quickly on a successor, as it will also compete in municipal elections in October and was expecting significant gains. There will be a number of contenders to succeed him including from the parliamentary wing, led by his niece Ivone Soares, its secretary general, Manuel Bissopo, and a few others.

But Renamo’s key leverage for now remains some 1,000 middle-aged gunmen in central Mozambique who have been stoically loyal to Dhlakama since the 1980s and who have little respect for the younger generation of professional politicians based in Maputo. Some may be bought off by government offers, others integrated into localised organized crime groups and others into internal Renamo sectarianism. The risk of fragmentation is real.

Renamo’s weakness could also embolden Frelimo hardliners to seek a return to unilateral domination of Mozambique’s political landscape, and to undermine the peace process. That would be a serious tactical mistake by Frelimo, as a lasting deal is close and the death of Dhlakama could actually assist in making this settlement lasting. Dhlakama was quixotic and prone to changing his mind, often influenced by the last person he spoke to – his death potentially introduces greater predictability in negotiations and in any post-deal implementation.

President Nyusi is clearly aware of this as he hailed on state television TVM that Dhlakama was ‘a citizen who has always worked for Mozambique’ and said he was distraught at the news of his death. He stated, ‘I hope that we as Mozambicans can continue to do everything so things do not go down.’ He also addressed Renamo’s support base by saying that ‘[Dhlakama] did everything so that there would be peace. The last time he spoke to me, he said he was not going to miss out anything in peace negotiations.’

Renamo’s gunmen are fatigued and want to retire with dignity but are vulnerable to manipulation and political miscalculation by Mozambican’s positioning politicians. International partners and investors can engage, by emphasizing that sustainable peace is the only pathway to poverty reduction and inclusive economic development.

This includes assisting development and reconciliation projects in areas impacted by the renewed conflict since 2013. Long-term investment for development in Renamo’s key constituencies could help avoid fragmentation at a critical time – faith groups and NGOs may also have a key role to play.

If Mozambique’s politicians continue to act in good faith, the death of Dhlakama may constitute a significant opportunity to finally draw a line under Mozambique’s long war.

Nov. 2, 2023 — Researchers from the Argonne Leadership Computing Facility (ALCF), the University of St. Thomas, and the University of Illinois Chicago (UIC) won first place and “best workflow” […]

The post ALCF Team Wins 1st Place and Best Workflow at 2023 IEEE SciVis Contest appeared first on HPCwire.

In his 2000 bestseller "The Tipping Point," Malcolm Gladwell told the story of why crime fell in New York City in the 1990s. Now, 25 years later, he's back with a confession and a mea culpa: "I was wrong," he says. He shares how his analysis contributed to the rise of the infamous "stop and frisk" policing policy in New York City — and shows why journalists should avoid the trap of imagining a story is ever really over. (Followed by a Q&A with TED's Monique Ruff-Bell)

The precise regulation of Ca²⁺ signals plays a crucial role in the physiological functions of neurons. Here, we investigated the rapid effect of glucocorticoids on Ca²⁺ signals in cultured hippocampal neurons from both female and male rats. In cultured hippocampal neurons, glucocorticoids inhibited the spontaneous somatic Ca²⁺ spikes generated by Kv2.1-organized Ca²⁺ microdomains. Furthermore, glucocorticoids rapidly reduced the cell surface expressions of Kv2.1 and Ca_V1.2 channels in hippocampal neurons. In HEK293 cells transfected with Kv2.1 alone, glucocorticoids significantly reduced the surface expression of Kv2.1 with little effect on K⁺ currents. In HEK293 cells transfected with Ca_V1.2 alone, glucocorticoids inhibited Ca_V1.2 currents but had no effect on the cell surface expression of Ca_V1.2. Notably, in the presence of wild-type Kv2.1, glucocorticoids caused a decrease in the surface expression of Ca_V1.2 channels in HEK293 cells. However, this effect was not observed in the presence of nonclustering Kv2.1S586A mutant channels. Live-cell imaging showed that glucocorticoids rapidly decreased Kv2.1 clusters on the plasma membrane. Correspondingly, Western blot results indicated a significant increase in the cytoplasmic level of Kv2.1, suggesting the endocytosis of Kv2.1 clusters. Glucocorticoids rapidly decreased the intracellular cAMP concentration and the phosphorylation level of PKA in hippocampal neurons. The PKA inhibitor H89 mimicked the effect of glucocorticoids on Kv2.1, while the PKA agonist forskolin abrogated the effect. In conclusion, glucocorticoids rapidly suppress Ca_V1.2-mediated Ca²⁺ signals in hippocampal neurons by promoting the endocytosis of Kv2.1 channel clusters through reducing PKA activity.

Rome, 2 December 2014 – The Ministers of Agriculture of the European Union and of other Mediterranean countries welcomed FAO’s transformational changes implemented in the last two years, and underlined [...]

FAO was the international guest of honour at the 2017 Salon Goûts et Terroirs, a Swiss cultural and gastronomic exhibition that took place from 29 November - 3 December.

A remote camera captures the first-ever video of an erupting underwater volcano

A massive lava stream from Kilauea Volcano flows into the ocean from a lava tube at the Kamokuna ocean entry on the southeast side of the Big Island at sunrise. Credit Elyse Butler

Have you ever wondered why Yellowstone is full of hot springs, bubbling mudpots and geysers like Old Faithful? In this one-minute video, Ask Smithsonian host Eric Schulze explains the supervolcano that lies beneath this national park and answers the life-or-death question: Will it erupt in a fiery inferno anytime soon?

Unexplored iron-rich magma could help power current and future technologies

"Fascinating, Captain"

People using the library in the Arts and Culture Centre in St. John's are being forced to use alternate entrances due to an unsafe staircase in front of the building.

Genetically encoded calcium indicators (GECIs) allow for the noninvasive evaluation of neuronal activity in vivo, and imaging GECIs in Drosophila has become commonplace for understanding neural functions and connectivity in this system. GECIs can also be used as read-outs for studying sleep in this model organism. Here, we describe a methodology for tracking the activity of neurons in the fly brain using a two-photon (2p) microscopy system. This method can be adapted to perform functional studies of neural activity in Drosophila under both spontaneous and evoked conditions, as well as during spontaneous or induced sleep. We first describe a tethering and surgical procedure that allows survival under the microscopy conditions required for long-term recordings. We then outline the steps and reagents required for optogenetic activation of sleep-promoting neurons while simultaneously recording neural activity from the fly brain. We also describe the procedure for recording from two different locations—namely, the top of the head (e.g., to record mushroom body calyx activity) or the back of the head (e.g., to record central complex activity). We also provide different strategies for recording from GECIs confined to the cell body versus the entire neuron. Finally, we describe the steps required for analyzing the multidimensional data that can be acquired. In all, this protocol shows how to perform calcium imaging experiments in tethered flies, with a focus on acquiring spontaneous and induced sleep data.

The insect eggshell is a multifunctional structure with several important roles, including generating an entry point for sperm via the micropyle before oviposition, serving as an oviposition substrate attachment surface, and functioning as a protective layer during embryo development. Eggshell proteins play major roles in eggshell tanning and hardening following oviposition and provide molecular cues that define dorsal–ventral axis formation. Precise eggshell formation during ovarian follicle maturation is critical for normal embryo development and the synthesis of a defective eggshell often gives rise to inviable embryos. Therefore, simple and accurate methods for identifying eggshell proteins will facilitate our understanding of the molecular pathways regulating eggshell formation and the mechanisms underlying normal embryo development. This protocol describes how to isolate and enrich eggshells from mature oocytes of Aedes aegypti mosquitoes and how to extract their eggshell proteins for liquid chromatography with tandem mass spectrometry (LC–MS/MS) proteomic analysis. Although this methodology was developed for studying mosquito eggshells, it may be applicable to eggs from a variety of insects. Mosquitoes are ideal model organisms for this study as their ovarian follicle development and eggshell formation are meticulously regulated by blood feeding and their follicles develop synchronously throughout oogenesis in a time-dependent manner.