324139 research outputs found
Sort by
Attention to detail: exploring effects of model resolution and complexity in geospatial electrification modelling
Get PDFIn 2021, 675 million people globally lack access to electricity. Geospatial electrification tools can be used to identify the mix of grid-extension, mini-grids and stand-alone technologies that can supply currently unelectrified areas at the lowest cost. Several such tools have been developed, at different levels of modelling detail and complexity. In this paper, we improve the Open Source Spatial Electrification Tool (OnSSET) to develop a flexible geospatial electrification tool that can still run lighter rapid assessments for a first estimate of the technology split, but now also more detailed analysis with higher spatial and temporal resolution used for grid routing, distribution network design and optimization of hybrid mini-grid generation introduced through new algorithms. We compare the existing light and new more detailed versions of the tool through a case study of the north-western parts of the Democratic Republic of the Congo. We find that the new grid routing algorithm led to more off-grid technologies, and that the detailed design of distribution networks leads to a reduction in stand-alone technologies. The detailed optimization of hybrid mini-grids displays varying effects at different demand levels. Given the increased computational effort that is observed with higher modelling detail, we discuss the implications for scenario design and selection of geospatial electrification tool for future analyses aiming to support the achievement of SDG 7
Unwanted intrusive thoughts of infant-related sexual harm: prevalence and assessment of safety
No full textObjectives: Unwanted, intrusive thoughts (UITs) of intentional infant-related harm are common among birthing parents. Evidence to date has failed to find any association with physical aggression toward the infant. However, the relationship between UITs of infant-related sexual harm and sexual behaviours towards the infant has yet to be assessed. This is the purpose of the current study. Methods: Data were collected via a prospective, province-wide, unselected cohort of N = 763 English-speaking birthing parents, n = 502 of whom provided data for the current analysis. Interview assessments of UITs of infant-related sexual harm were administered at approximately 7-weeks postpartum and 4-months postpartum. Sexual harming behaviours toward the infant were assessed via an anonymized questionnaire at the end of the study. Results: UITs of infant-related sexual harm were reported by 9.2% (n=38; 95% CI [6.6, 12.4]) of participants. We found no evidence of an association between UITs of this nature and sexual behaviour toward one’s infant (Fisher’s exact, p=1.00). Only one participant reported engaging in sexual behaviour toward their infant, and they did not report any UITs of infant-related sexual harm. Conclusions: Study findings add to growing evidence that UITs of infant-related harm are common, and when these thoughts are unwanted and intrusive, they are not associated with an increased risk of actually harming one’s infant. Although findings suggest that this is also true for UITs of infant-related sexual harm and sexual behaviour, due to the small sample employed in this research, replication with a larger sample is needed
A brief, digital, imagery-competing task intervention for stopping intrusive memories in trauma-exposed health-care staff during the COVID-19 pandemic in the UK: a Bayesian adaptive randomised clinical trial
No full textBackground: Psychological trauma, such as witnessing an untimely or gruesome death, commonly provokes intrusive memories that might persist for days to years with adverse effects on individual mental and physical health and functioning. Despite the global prevalence of trauma, scalable evidence-based interventions are absent. Reducing the impact of intrusive memories is crucial for people frequently exposed to trauma, such as health-care workers. This study aimed to determine whether a brief digital imagery-competing task intervention (ICTI) reduced intrusive memory frequency after 4 weeks. Harms were also assessed.
Methods: The GAINS-02 decentralised digital, parallel-group Bayesian adaptive randomised controlled trial tested a brief ICTI against an active control and treatment as usual to determine the effect on reducing intrusive memory frequency. Health-care workers in facilities that admitted patients with COVID-19 during the pandemic, who had experienced one or more traumatic events and reported at least three intrusive memories in the week before screening were randomised 2:2:1 (ICTI to active control to treatment as usual) via block randomisation (web-based). ICTI and active control participants were masked to treatment allocation, and both had one guided session then optional self-use. ICTI involved image-based memory retrieval then Tetris computer gameplay with mental rotation. The active control involved a music-listening task. Study statisticians were masked to ICTI and active control group. The primary outcome was the number of intrusive memories in week 4 (controlling for baseline), which was evaluated on an intention-to-treat basis. Treatment effects for the intervention group versus the comparator groups were assessed using Bayes regression analyses. Harms were assessed through adverse event reporting and interim analyses on primary outcome. People with lived experience were involved from study conception and throughout the research and writing process. The trial was pre-registered at clinicaltrials.gov (NCT05616676) and is completed.
Findings: Between Dec 8, 2022, and Sept 15, 2023, 176 participants were screened and 99 included (ICTI n=40, active control n=39, treatment as usual n=20) with mean age 41·2 years (SD 10·2; range 21–62). Of these 99 participants, 85 (86%) self-identified as women and 89 (90%) as White. Bayesian analyses gave robust evidence that ICTI reduced intrusive memories at week 4: ICTI participants reported fewer intrusive memories (median 0·5 [IQR 0·0–5·0]) compared with the active control (active control 5·0 [3·0–11·5]; Bayes factor [BF]active control>ICTI vs active control=ICTI 114·1; βactive control>ICTI 1·29 [95% CrI 0·64–2·00]) and treatment as usual (median 5·0 [IQR 2·5–8·0]; BFtreatment as usual>ICTI vs treatment as usual=ICTI=15·8; βtreatment as usual>ICTI 1·21 [95% CrI 0·49–1·98]) groups. No harms were detected for ICTI relative to the active control and treatment as usual. The most reported adverse event (n=7) was COVID-19. Two adverse events involved burden of diary recording. Serious adverse events were hospitalisations unrelated to study procedures (n=6).
Interpretation: This study shows that ICTI reduces intrusive memory frequency and post-traumatic stress disorder symptoms among health-care workers exposed to trauma. As a brief, scalable digital intervention, ICTI shows promise for mitigating consequences of trauma on mental health, an important and unmet need for health-care personnel and systems worldwide
Dipole and pairwise models for the motion of bubbles in a Hele-Shaw cell
Get PDFWe consider the motion of an arbitrary number of approximately circular bubbles in a Hele-Shaw cell. Each bubble is assumed to be large enough that it is flattened by the cell walls into a pancake-like shape, but small enough to remain approximately circular in plan view. Numerical solutions of the full Hele-Shaw problem become computationally expensive when there is a large number of bubbles. It is therefore common in the literature when modelling a large number of bubbles to assume that each bubble acts like a dipole. Here, we provide the theoretical basis for this approach through the use of matched asymptotic expansions, in the limit where the bubbles are all far apart. We find that this method qualitatively reproduces the behaviour of the full model at a much reduced computational cost, provided the bubbles remain well separated. We also derive a pairwise interaction model by summing over the contributions due to each possible bubble pair. This improved model has computational complexity comparable to that of the dipole model but remains valid in situations in which two bubbles become close
Analysis of logics with arithmetic
No full textWe present new results on finite satisfiability of logics with counting and arithmetic. One result is a tight bound on the complexity of satisfiability of logics with so-called local Presburger quantifiers, which sum over neighbors of a node in a graph. A second contribution concerns computing a semilinear representation of the cardinalities associated with a formula in two variable logic extended with counting quantifiers. Such a representation allows you to get bounds not only on satisfiability for these logics, but for satisfiability in the presence of additional “global cardinality constraints”: restrictions on cardinalities of unary formulas, expressed using arbitrary decidability logics over arithmetic. In the process, we provide simpler proofs of some key prior results on finite satisfiability and semi-linearity of the spectrum for these logics
Does the shale gas revolution hinder clean energy innovation?
No full textWe analyze the causal impact of the U.S. shale gas revolution on technological innovation in the electricity generation sector. Using a country-level data set of electricity patents from 1978-2018, we find that the U.S. shale gas revolution led to a 1.60 decrease in the ratio of green to fossil-fuel electricity patents and a 0.93 decrease in the ratio of renewable to fossil-fuel electricity patents. In addition, we find a 0.15 increase in the share of fossil-fuel electricity patenting. These results suggest that the U.S. shale boom hinder the development of new and improved technologies that ease the decarbonization of the electricity sector
Tides of transition: vehicle flows, afterlives, and the remaking of mobility in Africa
No full textThe geography of vehicle exports to Africa is shifting from established North–South circuits of second-hand automobiles to emerging East–South exchanges led by China and India. Unsettling longstanding geopolitical hierarchies, the growing influx of used cars and electric two- and three-wheelers from the Global East is reshaping mobility cultures and infrastructures, regimes of value, and livelihood across the continent. However, this influx risks exacerbating existing, or creating new socio-environmental burdens, related to road traffic crashes, toxic end-of-life vehicles and electric vehicle batteries. These issues illuminate the tensions of low-carbon transitions globally, extending both access to affordable green mobility technologies and the associated human-environmental hazards. Africa’s position within these evolving automotive geographies reveals the spatial and moral asymmetries of global mobility transitions
Heterogeneity in macroeconomic expectations: theory, evidence, and implications
No full textThis thesis examines the origins of heterogeneity in macroeconomic expectations, particularly inflation expectations, and its impact on economic behavior and the transmission of monetary policy. Drawing on theory and rich microdata from household, firm and expert surveys across multiple countries, I provide an integrated perspective on expectation formation mechanisms and their implications.I begin by exploring one specific dimension of heterogeneity: the gender gap in inflation expectations. The first chapter argues that differences in forecast confidence, rather than exposure to specific prices, account for why women, on average, report higher inflation expectations than men. I then proceed to investigate the consequences of this gap, demonstrating first how gendered beliefs shape wage bargaining behavior (Chapter 2) and secondly how they influence trust in and responsiveness to central bank communication (Chapter 3).Broadening the scope, the final chapter compares inflation expectations between different types of economic agents: households, firms, social partners, and economists. I find systematic differences in levels, dispersion, and sensitivity to shocks which highlight the limitations of representative-agent assumptions and underscore the need for more inclusive, behaviorally informed approaches to monetary policy design.Taken together, the chapters highlight the importance of expectation heterogeneity not only for understanding inflation dynamics but also for addressing distributional concerns and improving central bank communication
Raman Microspectroscopy for Structural Indication in Ultrafast Laser Writing
No full textFemtosecond laser fabrication enables the creation of a wide range of devices, but its scalability and yield can be limited by the lack of real‐time, in situ monitoring tools. In particular, there is a strong need for metrics that directly correlate with device performance. Raman microspectroscopy provides a non‐destructive route for in situ characterization. Here, we demonstrate its potential to assess the electrical performance of laser‐written graphitic electrodes in diamond. By combining hyperspectral mapping with electrical testing, we show that depletion of the 1332 cm − 1 sp3 Raman line serves as a monotonic and robust predictor of resistance, offering clear advantages over commonly used spectral features. We further introduce hyperspectral unmixing as a label‐free approach to identify relevant spectral signatures in fabrication processes where Raman markers are less defined. Importantly, the methodology we present is not restricted to diamond but can be adapted to other host materials and functionalities, offering a practical path toward specification‐driven fs‐laser microfabrication