Chain Of Events Research Articles

CSF dynamics of orexin and β-amyloid42 levels in narcolepsy and Alzheimer’s disease patients: a controlled study

β-amyloid42 (Aβ42) in Alzheimer’s disease (AD) and orexin in narcolepsy are considered crucial biomarkers for diagnosis and therapeutic targets. Recently, orexin and Aβ cerebral dynamics have been studied in both pathologies, but how they interact with each other remains further to be known. In this study, we investigated the reliability of using the correlation between orexin-A and Aβ42 CSF levels as a candidate marker to explain the chain of events leading to narcolepsy or AD pathology. In order to test the correlation between these biomarkers, patients diagnosed with AD (n = 76), narcolepsy type 1 (NT1, n = 17), narcolepsy type 2 (NT2, n = 23) and healthy subjects (n = 91) were examined. Patients and healthy subjects underwent lumbar puncture between 8:00 and 10:00 am at the Neurology Unit of the University Hospital of Rome “Tor Vergata”. CSF levels of Aβ42, total-tau, phosphorylated-tau, and orexin-A were assessed. The results showed that CSF levels of Aβ42 were significantly lower (p < 0.001) in AD (332.28 ± 237.36 pg/mL) compared to NT1 (569.88 ± 187.00 pg/mL), NT2 (691.00 ± 292.63 pg/mL) and healthy subjects (943.68 ± 198.12 pg/mL). CSF orexin-A levels were statistically different (p < 0.001) between AD (148.01 ± 29.49 pg/mL), NT1 (45.94 ± 13.63 pg/mL), NT2 (104.92 ± 25.55 pg/mL) and healthy subjects (145.18 ± 27.01 pg/mL). Moderate-severe AD patients (mini mental state examination < 21) showed the highest CSF orexin-A levels, whereas NT1 patients showed the lowest CSF orexin-A levels. Correlation between CSF levels of Aβ42 and orexin-A was found only in healthy subjects (r = 0.26; p = 0.01), and not in narcolepsy or AD patients. This lack of correlation in both diseases may be explained by the pathology itself since the correlation between these two biomarkers is evident only in the healthy subjects. This study adds to the present literature by further documenting the interplay between orexinergic neurotransmission and cerebral Aβ dynamics, possibly sustained by sleep.

Analysis of solar plasma parameters during intense geomagnetic storm (SYM/H

We utilize numerous solar plasma and field parameters with geomagnetic indices for the geomagnetic storm in 25 solar cycles. Using Planetary index (Kp) having 3 h data, Dst index hourly data, Symmetric horizontal field (SYM/H) minute resolution data and solar plasma measurements from multiple satellites, examine the chain of significant events that occurred in the year 2023. Statical analysis of geomagnetic provisional activity Sym/H has better results than Kp index during various main phases of geomagnetic activity. The statistical correlation technique is used to examine the relationship between Interplanetary parameters and geomagnetic indices during major geomagnetic storms. This research improves our comprehension of solar–terrestrial interactions and provides valuable insights for enhancing space weather forecasting models.

Integrating Relational Knowledge With Text Sequences for Script Event Prediction.

Script event prediction aims to infer subsequent events given an incomplete script. It requires a deep understanding of events, and can provide support for a variety of tasks. Existing models rarely consider the relational knowledge between events, they regard scripts as sequences or graphs, which cannot capture the relational information between events and the semantic information of script sequences jointly. To address this issue, we propose a new script form, relational event chain, that combines event chains and relational graphs. We also introduce a new model, relational-transformer, to learn embeddings based on this new script form. In particular, we first extract the relationship between events from an event knowledge graph to formalize scripts as relational event chains, then use the relational-transformer to calculate the likelihood of different candidate events, where the model learns event embeddings that encode both semantic and relational knowledge by combining transformers and graph neural networks (GNNs). Experimental results on both one-step inference and multistep inference tasks show that our model can outperform existing baselines, indicating the validity of encoding relational knowledge into event embeddings. The influence of using different model structures and different types of relational knowledge is analyzed as well.

Insights into the Causes and Predictability of the 2022/23 California Flooding

Abstract In late December of 2022 and the first half of January 2023, an unprecedented series of atmospheric rivers (ARs) produced near-record heavy rains and flooding over much of California. Here, we employ the NASA GEOS AGCM run in a “replay” mode, together with more idealized simulations with a stationary wave model, to identify the remote forcing regions, mechanisms, and underlying predictability of this flooding event. In particular, the study addresses the underlying causes of a persistent positive Pacific–North American (PNA)-like circulation pattern that facilitated the development of the ARs. We show that the pattern developed in late December as a result of vorticity forcing in the North Pacific jet exit region. We further provide evidence that this vorticity forcing was the result of a chain of events initiated in mid-December with the development of a Rossby wave (as a result of forcing linked to the MJO) that propagated from the northern Indian Ocean into the North Pacific. As such, both the initiation of the event and the eventual development of the PNA depended critically on internally generated Rossby wave forcings, with the North Pacific jet playing a key role. This, combined with contemporaneous SST (La Niña) forcing that produced a circulation response in the AGCM that was essentially opposite to the positive PNA, underscores the fundamental lack of predictability of the event at seasonal time scales. Forecasts produced with the GEOS-coupled model suggest that useful skill in predicting the PNA and extreme precipitation over California was in fact limited to lead times shorter than about 3 weeks.

Portrayals of translation and interpreting in an early trinidadian novel: a case study of “Warner Arundell: The adventures of a creole”

Commonly held to be the first Trinidadian novel, E. L. Joseph’s Warner Arundell: The Adventures of a Creole was first published in 1838. Presented as a fictional memoir, the book’s wide-ranging plot spans many of the geographical, cultural, and linguistic spaces which characterised the Caribbean during the early nineteenth century. Though language and multilingualism play an important role in the novel and have been discussed in scholarly analyses, this study zooms in on the representation of translation and interpreting in the novel. With the book’s hero a gifted linguist, his skills as a translator and interpreter are often highly relevant to key moments in the work’s intricate chain of events. As such, in the first instance, a brief overview of selected historical and fictional aspects of translation and interpreting in the Caribbean context is given, as well as some remarks on the history of the Caribbean and on the biography of the book’s author. The novel’s three volumes are then analysed, and relevant scenes involving translation and/or interpreting are highlighted and discussed. Lastly, the conclusion offers some general thoughts on the role of literary analyses with regard to the history of translation and interpreting in colonial milieux.

Who has an R&amp;D investment opportunity? Who goes ahead? How much do they invest?

We know a lot about how much firms invest in R&amp;D, but less about the critical first step which is a potential R&amp;D opportunity. We use a large UK survey and detailed case study evidence to establish the chain of events from opportunity to the investment choice. Our results show that 34% of firms had identified an R&amp;D investment opportunity. Realised R&amp;D investment projects were typically between £100,000 and £1/2 m over a 5‐year window. The dominant factors were firm size, industry, equity investment, knowledge and absorptive capacity. The process of R&amp;D management also had an outward, market facing aspect, and an inward, engineering and financial aspect that were often conducted in parallel.

A framework for process risk assessment incorporating prior hazard information in text mining models using chunking

In process industries, complexity of operations and continuous exposure to hazardous substances, equipment and environment necessitates performing fault detection and diagnosis (FDD), and risk assessment via accident/failure modelling. Safety reports contain important information regarding health of process systems, hence FDD and risk assessment by text mining of reports is vital to identify potential faults, reveal insights on their behaviour/interactions, and predict hazard escalation into incidents. Here a novel hybrid framework is proposed where accident theory and hazard information are combined with text mining of incident descriptions to perform FDD and accident modelling. Information about hazards and failure events is used to generate syntactic rules of accident causation which are used to extract text chunks from incident descriptions depicting constituent faults/process safety events. Then an ensemble of unsupervised/semi-supervised models is applied on the chunks to identify hazardous elements and develop chain of events and fault trees showcasing failure propagation. The framework is applied on incident investigation reports of an Indian steel plant and 56 chains of events and corresponding 13 fault trees are identified. A comparison of the results generated by the framework with actual inputs provided by the HSE team of the plant showed accuracy of 85.42 %.

A nationwide longitudinal investigation on the role of prenatal exposure to infectious diseases on the onset of chronic conditions in children and adolescents in Brazil

Background In utero exposure to infections might set the stage for a chain of events leading to a wide spectrum of long-term health outcomes observed in children and adolescents. This proposal aims to investigate whether syphilis, zika, dengue and chikungunya during pregnancy can increase the risk of the offspring developing a non-infectious chronic condition during childhood and adolescence. Objectives 1) Estimate the risk of non-infectious chronic conditions associated to syphilis, zika, dengue and chikungunya during pregnancy and explore if the risk varies by timing during pregnancy when the infection is acquired (first, second or third trimester) and severity (such as severe or mild dengue); 2) Investigate whether in uterus exposure to maternal infection affects the growth pattern of children and adolescents; 3) Examine the extent to which the relationship between maternal infection and non-infectious chronic outcomes are mediated by intrauterine growth restriction and preterm birth. Methods We will compare health outcomes and growth trajectories of children and adolescents born to mothers with and without specific infections during pregnancy using conventional multivariable regression in the whole study population, in a within sibship design, using the subgroup of offspring with at least one sibling who is not exposed to the infection, and negative control outcome. Then we will decompose the direct and mediated effects (by preterm birth and small for gestational age) of maternal infection on chronic disorders. Results and Conclusions The results from this study will advance our understanding of the relationship between infections during pregnancy and chronic disorders, with widespread implications enabling targeting of critical points along the path from in utero exposure to outcomes to avoid or mitigate illness and disability over the life course.

Molecular Approaches Detect Early Signals of Programmed Cell Death in Hippolyte inermis Leach.

The protandric shrimp Hippolyte inermis is the only known marine invertebrate whose sex determination is strongly influenced by the composition of its food. In H. inermis, a sex reversal is triggered by the ingestion of diatoms of the genus Cocconeis associated with leaves of the seagrass Posidonia oceanica. These diatoms contain compounds that promote programmed cell death (PCD) in H. inermis and also in human cancer cells. Transcriptomic analyses suggested that ferroptosis is the primary trigger of the shrimp's sex reversal, leading to the rapid destruction of the androgen gland (AG) followed by a chain of apoptotic events transforming the testes into ovaries. Here, we propose a molecular approach to detect the effects of compounds stimulating the PCD. An RNA extraction method, suitable for young shrimp post-larvae (five days after metamorphosis; PL5 stage), was established. In addition, six genes involved in apoptosis, four involved in ferroptosis, and seven involved in the AG switch were mined from the transcriptome, and their expression levels were followed using real-time qPCR in PL5 fed on Cocconeis spp., compared to PL5 fed on a basic control feed. Our molecular approach, which detected early signals of sex reversal, represents a powerful instrument for investigating physiological progression and patterns of PCD in marine invertebrates. It exemplifies the physiological changes that may start a few days after the settlement of post-larvae and determine the life destiny of an individual.

Scientific opinion on the tolerable upper intake level for iron.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the tolerable upper intake level (UL) for iron. Systematic reviews were conducted to identify evidence regarding high iron intakes and risk of chronic diseases, adverse gastrointestinal effects and adverse effects of iron supplementation in infancy, young childhood and pregnancy. It is established that systemic iron overload leads to organ toxicity, but no UL could be established. The only indicator for which a dose-response could be established was black stools, which reflect the presence of large amounts of unabsorbed iron in the gut. This is a conservative endpoint among the chain of events that may lead to systemic iron overload but is not adverse per se. Based on interventions in which black stools did not occur at supplemental iron intakes of 20-25 mg/day (added to a background intake of 15 mg/day), a safe level of intake for iron of 40 mg/day for adults (including pregnant and lactating women) was established. Using allometric scaling (body weight0.75), this value was scaled down to children and adolescents and safe levels of intakes between 10 mg/day (1-3 years) and 35 mg/day (15-17 years) were derived. For infants 7-11 months of age who have a higher iron requirement than young children, allometric scaling was applied to the supplemental iron intakes (i.e. 25 mg/day) and resulted in a safe level of supplemental iron intake of 5 mg/day. This value was extended to 4-6 month-old infants and refers to iron intakes from fortified foods and food supplements, not from infant and follow-on formulae. The application of the safe level of intake is more limited than a UL because the intake level at which the risk of adverse effects starts to increase is not defined.

Current treatment approaches in the management of the heart failure

Heart failure is a clinical syndrome in which the function of the heart muscle and neurohormonal regulation are impaired, resulting in an inability to meet the metabolic needs of tissues. Many different mechanisms are involved in the pathophysiology of heart failure. Therefore, this disease is defined as a chronic disease in which treatment management is difficult for both the patient and the physician. Therefore, although the main goal is to take the necessary precautions before the disease develops, this may not always be possible. The management of the disease and the treatment options are being provided by finding drugs that are effective against existing mechanisms or against new mechanisms that have been discovered. The main goal of treatment is to stop the chain of events that cause and worsen heart failure based on the physiopathology. For this reason, there are various treatment modalities accepted in current guidelines to manage the current process. The aim of these treatments is to reduce symptoms, improve quality of life, and reduce mortality and morbidity rates. Recently, many important developments in the field of heart failure have started to come one after another. In this article, the mechanisms of action of the current treatment options and their effects on mortality have been mentioned, but rather than the current pharmacologic treatments, promising new treatment options, especially phase 3 and phase 4 trials, have been evaluated.

Organ transformation by environmental disruption of protein integrity and epigenetic memory in Drosophila.

Despite significant progress in understanding epigenetic reprogramming of cells, the mechanistic basis of "organ reprogramming" by (epi-)gene-environment interactions remained largely obscure. Here, we use the ether-induced haltere-to-wing transformations in Drosophila as a model for epigenetic "reprogramming" at the whole organism level. Our findings support a mechanistic chain of events explaining why and how brief embryonic exposure to ether leads to haltere-to-wing transformations manifested at the larval stage and on. We show that ether interferes with protein integrity in the egg, leading to altered deployment of Hsp90 and widespread repression of Trithorax-mediated establishment of active H3K4me3 chromatin marks throughout the genome. Despite this global reduction, Ubx targets and wing development genes preferentially retain higher levels of H3K4me3 that predisposes these genes for later up-regulation in the larval haltere disc, hence the wing-like outcome. Consistent with compromised protein integrity during the exposure, the penetrance of bithorax transformations increases by genetic or chemical reduction of Hsp90 function. Moreover, joint reduction in Hsp90 and trx gene dosage can cause bithorax transformations even without exposure to ether, supporting an underlying epistasis between Hsp90 and trx loss-of-functions. These findings implicate environmental disruption of protein integrity at the onset of histone methylation with altered epigenetic regulation of developmental patterning genes. The emerging picture provides a unique example wherein the alleviation of the Hsp90 "capacitor function" by the environment drives a morphogenetic shift towards an ancestral-like body plan. The morphogenetic impact of chaperone response during a major setup of epigenetic patterns may be a general scheme for organ reprogramming by environmental cues.

Detrimental effects of scene manipulations on temperature-based time since death estimation

In forensic casework, time since death (TSD) estimations may play a crucial role to establish chains of events as well as for alibi assessment in homicide cases. Classical TSD estimation relies on reasonably stable ambient temperatures and a correct documentation of ambient and rectal temperatures. This constancy is in some cases disturbed by post-discovery alterations of the crime scene, e.g. opening a window. In order to develop a better understanding of this alteration-based detrimental impact on TSD estimation as well as to identify feasible recommendations for casework, the present pilot study examined ambient temperature effects of different window opening scenarios regarding various time intervals (5 to 360 min) in a furnished 10 m2 apartment during winter. In this context, in addition to the ambient temperature and thus the cooling rate of the room, re-approximation to initial room temperature, potential influences on a nomogram-based time since death estimation using a fictitious case, and the impact of the measurement height above the ground were investigated. Our data indicate a significant reduction of the mean temperature decrease rate after 15 min regardless of the remaining opening time and a correlation with the size of the respective opening surfaces. Re-approximation to initial room temperatures was observed with up to three times longer than the initial opening time. There was no evidence of a substantial advantage of temperature measurements above the level of the corpse (> 0.1 m). The limitations of the study and its applicability for forensic casework are critically reviewed.

How a project design becomes a macro-actor: laboratory simulations in trials of strength between competing bridge designs, project budgets and sustainability

PurposeThis paper shows how Bruno Latour’s novel work and methodological approach can enrich management and organization studies, accounting and science and technology studies on what it takes to redesign sustainable societal infrastructures. Latour’s notions of trials of strength, macro-actor and design as redesign are used in a case study to describe and analyse how the laboratory becomes decisive in negotiating the bridge design and project budget to the benefit of a more sustainable transport infrastructure.Design/methodology/approachLatour’s notion of the detective-author is used to research and write a longitudinal qualitative case study that reconstructs the project processes and chain of related events by following the actors/actants.FindingsThe case analysis shows how a project design becomes an emerging powerful macro-actor through the mobilization of laboratory simulations and calculations. The role of the project budget changes; from a strong supporting role as input to a decision option in favour of a cheaper stayed bridge to a weak role as an output from a process of redesign supporting a much larger, costlier and more sustainable suspension bridge.Originality/valueWe use Latour’s methodological approach to engage primarily in detailed process descriptions to go beyond the often-pointless call for further theory development and to rather account for what is at work in specific situations. Latour’s notions of redesign as an outcome from trials of strength, we consider a useful approach to further our understanding since it also takes account of the distributed knowledge production that is integral to the actors’ cognitions and recognitions. Relatedly, the specific Latourian notion of redesign opens up new avenues for researching the more or less powerful role accounting devices such as a project budget can play in valuing, supporting and/or undermining the design of sustainable societal infrastructures.

DECAF cross-device characterization of tokamak disruptions indicated by abnormalities in plasma vertical position and current

Abnormal (deviating from the target) variations in the plasma vertical position Z and current Ip (such as vertical displacements, transient Ip ‘spikes’ and quenches) constitute common elements of a disruption, a phenomenon that is to be mitigated, or ultimately avoided in future reactor-relevant tokamaks. While these abnormalities are generally recognized cross-shot and cross-device, details in terms of appearance (or not) and order of these abnormalities in disruption event chains (DEC) are bound to the plasma state at the time of the chain initiation. Detection of these abnormalities is thus indicative not only of the onset of the plasma collapse itself but also of the disruption driving cause that is promoted at a particular plasma state. Here, the occurrence of disruptions, explored via the detection of an Ip quench, and the analysis of DEC constituted by Ip and Z abnormalities is reported for in total seven full device-year pairs of operation of three machines (4, 2 and 1 years of KSTAR, MAST-U and NSTX-U operation, respectively) using the DECAF code expanded tools and capabilities. It is shown that the disruption occurrence depends not only on the details of the plasma state but also on (device-dependent) technical elements of the shot exit scenario. Year-to-year changes in the main disruption causes and a reduction in the disruptivity rate, bound by device and operation upgrades, are reported. Particular trigger instances of DEC (and the full chains when applicable) are shown to occupy different parts of the operation space diagrams, in accordance with prior expectations. Plasma elongation is identified as an important factor influencing details of the chains and its role will be further explored.

Network-based visualisation of frequent sequences.

Frequent sequence pattern mining is an excellent tool to discover patterns in event chains. In complex systems, events from parallel processes are present, often without proper labelling. To identify the groups of events related to the subprocess, frequent sequential pattern mining can be applied. Since most algorithms provide too many frequent sequences that make it difficult to interpret the results, it is necessary to post-process the resulting frequent patterns. The available visualisation techniques do not allow easy access to multiple properties that support a faster and better understanding of the event scenarios. To answer this issue, our work proposes an intuitive and interactive solution to support this task, introducing three novel network-based sequence visualisation methods that can reduce the time of information processing from a cognitive perspective. The proposed visualisation methods offer a more information rich and easily understandable interpretation of sequential pattern mining results compared to the usual text-like outcome of pattern mining algorithms. The first uses the confidence values of the transitions to create a weighted network, while the second enriches the adjacency matrix based on the confidence values with similarities of the transitive nodes. The enriched matrix enables a similarity-based Multidimensional Scaling (MDS) projection of the sequences. The third method uses similarity measurement based on the overlap of the occurrences of the supporting events of the sequences. The applicability of the method is presented in an industrial alarm management problem and in the analysis of clickstreams of a website. The method was fully implemented in Python environment. The results show that the proposed methods are highly applicable for the interactive processing of frequent sequences, supporting the exploration of the inner mechanisms of complex systems.

IL21 inhibits miR-361-5p to promote MAP3K9 and further aggravate the progression of shoulder arthritis.

This research aimed to explore IL-21/miR-361-5p/MAP3K9 expression in shoulder arthritis and identify its regulatory pathways. We established a rat shoulder arthritis model, then quantified IL21 and miR-361-5p in synovial fluid using ELISA and monitored the arthritis development. Additionally, IL21's effect on miR-361-5p levels in cultured human chondrocytes (HC-a) was assessed. Chondrocyte cell cycle status and apoptosis were measured via flow cytometry. Interactions between miR-361-5p and MAP3K9 were confirmed through dual-luciferase reporting and bioinformatic scrutiny. Protein levels of MAP3K9, p-ERK1/2, p-NF-κB, MMP1, and MMP9 were analyzed by Western blots. IL21 levels were elevated, while miR-361-5p was reduced in the synovial fluid from arthritic rats compared to healthy rats. IL21 was shown to suppress miR-361-5p in chondrocytes leading to hindered cell proliferation and increased apoptosis. Western blots indicated that miR-361-5p curbed MAP3K9 expression, reducing MMP activity by attenuating the ERK1/2/NF-κB pathway in chondrocytes. IL21 upregulation and miR-361-5p downregulation characterize shoulder arthritis, resulting in MAP3K9 overexpression. This chain of molecular events boosts MMP expression in chondrocytes and exacerbates the condition's progression.

The Enigma of Norbormide, a Rattus-Selective Toxicant.

Norbormide (NRB) is a Rattus-selective toxicant, which was serendipitously discovered in 1964 and formerly marketed as an eco-friendly rodenticide that was deemed harmless to non-Rattus species. However, due to inconsistent efficacy and the emergence of second-generation anticoagulants, its usage declined, with registration lapsing in 2003. NRBs' lethal action in rats entails irreversible vasoconstriction of peripheral arteries, likely inducing cardiac damage: however, the precise chain of events leading to fatality and the target organs involved remain elusive. This unique contractile effect is exclusive to rat arteries and is induced solely by the endo isomers of NRB, hinting at a specific receptor involvement. Understanding NRB's mechanism of action is crucial for developing species-selective toxicants as alternatives to the broad-spectrum ones currently in use. Recent research efforts have focused on elucidating its cellular mechanisms and sites of action using novel NRB derivatives. The key findings are as follows: NRB selectively opens the rat mitochondrial permeability transition pore, which may be a factor that contributes to its lethal effect; it inhibits rat vascular KATP channels, which potentially controls its Rattus-selective vasoconstricting activity; and it possesses intracellular binding sites in both sensitive and insensitive cells, as revealed by fluorescent derivatives. These studies have led to the development of a prodrug with enhanced pharmacokinetic and toxicological profiles, which is currently undergoing registration as a novel efficacious eco-sustainable Rattus-selective toxicant. The NRB-fluorescent derivatives also show promise as non-toxic probes for intracellular organelle labelling. This review documents in more detail these developments and their implications.

Earth’s geomagnetic environment—progress and gaps in understanding, prediction, and impacts

Understanding of Earth’s geomagnetic environment is critical to mitigating the space weather impacts caused by disruptive geoelectric fields in power lines and other conductors on Earth’s surface. These impacts are the result of a chain of processes driven by the solar wind and linking Earth’s magnetosphere, ionosphere, thermosphere and Earth’s surface. Tremendous progress has been made over the last two decades in understanding the solar wind driving mechanisms, the coupling mechanisms connecting the magnetically controlled regions of near-Earth space, and the impacts of these collective processes on human technologies on Earth’s surface. Studies of solar wind drivers have been focused on understanding the responses of the geomagnetic environment to spatial and temporal variations in the solar wind associated with Coronal Mass Ejections, Corotating Interaction Regions, Interplanetary Shocks, High-Speed Streams, and other interplanetary magnetic field structures. Increasingly sophisticated numerical models are able to simulate the magnetospheric response to the solar wind forcing associated with these structures. Magnetosphere-ionosphere-thermosphere coupling remains a great challenge, although new observations and sophisticated models that can assimilate disparate data sets have improved the ability to specify the electrodynamic properties of the high latitude ionosphere. The temporal and spatial resolution needed to predict the electric fields, conductivities, and currents in the ionosphere is driving the need for further advances. These parameters are intricately tied to auroral phenomena—energy deposition due to Joule heating and precipitating particles, motions of the auroral boundary, and ion outflow. A new view of these auroral processes is emerging that focuses on small-scale structures in the magnetosphere and their ionospheric effects, which may include the rapid variations in current associated with geomagnetically induced currents and the resulting perturbations to geoelectric fields on Earth’s surface. Improvements in model development have paralleled the advancements in understanding, yielding coupled models that better replicate the spatial and temporal scales needed to simulate the interconnected domains. Many realizations of such multi-component systems are under development, each with its own limitations and advantages. Challenges remain in the ability of models to quantify uncertainties introduced by propagation of solar wind parameters, to account for numerical effects in model codes, and to handle the special conditions occurring during extreme events. The impacts to technical systems on the ground are highly sensitive to the local electric properties of Earth’s surface, as well as to the specific technology at risk. Current research is focused on understanding the characteristics of geomagnetic disturbances that are important for geomagnetically induced currents, the development of earth conductivity models, the calculation of geoelectric fields, and the modeling of induced currents in the different affected systems. Assessing and mitigating the risks to technical systems requires quantitative knowledge of the range of values to be expected under all possible geomagnetic and technical conditions. Considering the progress that has been made in studying the chain of events leading to hazardous geomagnetic disturbances, the path forward will require concerted efforts to reveal missing physics, improve modeling capabilities, and deploy new observational assets. New understanding should be targeted to accurately quantify solar wind driving, magnetosphere-ionosphere-thermosphere coupling, and the impacts on specific technologies. The research, modeling, and observations highlighted here provide a framework for constructing a plan by which the international science community can comprehensively address the growing threat to human technologies caused by geomagnetic disturbances.

WCD Ideas: Teleconnections through weather rather than stationary waves

Abstract. Conventionally, teleconnections in the atmosphere are described by correlations between monthly mean fields. These correlations are supposedly caused by stationary Rossby waves. The main hypothesis explored in this idea is that teleconnections are instead established by chains of events on synoptic timescales, that is by weather. Instead I hypothesise that non-stationary Rossby waves play an important role in establishing teleconnections. If these hypotheses are correct, much of the vast literature on this topic misses an essential part of the atmospheric dynamics leading to teleconnections.