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Functional diffusion driven stochastic volatility model
Get PDFWe propose a stochastic volatility model for time series of curves. It is motivated by dynamics of intraday price curves that exhibit both between days dependence and intraday price evolution. The curves are suitably normalized to stationary in a function space and are functional analogs of point-to-point daily returns. The between curves dependence is modeled by a latent autoregression. The within curves behavior is modeled by a diffusion process. We establish the properties of the model and propose several approaches to its estimation. These approaches are justified by asymptotic arguments that involve an interplay between the latent autoregression and the intraday diffusions. The asymptotic framework combines the increasing number of daily curves and the refinement of the discrete grid on which each daily curve is observed. Consistency rates for the estimators of the intraday volatility curves are derived as well as the asymptotic normality of the estimators of the latent autoregression. The estimation approaches are further explored and compared by an application to intraday price curves of over seven thousand U.S. stocks and an informative simulation study
Signalling through managerial tone and analysts’ response
Get PDFThis study investigates the interaction between a tone signaller and receiver through managerial tone on a conference call. Based on a signalling framework, we examine the following research questions: Does the signal (tone) match the latent information it intends to convey? Can a receiver (analyst) interpret the signal correctly and send feedback to confirm (or disconfirm) it? Does the signalling environment impact signalling effectiveness? Using a sample of 3680 transcripts of earnings conference calls from 241 UK firms in the FTSE 350 Index, we find that managerial tone can produce effective signals that match private information from managers. Analysts understand tone signals accurately and send confirmation feedback to managers. They revise their forecasts upward (downward) following more (less) optimistic managerial tones. They consistently confirm and respond to managers with a similar tone. Analysts with superior expertise, experience and ability better understand the tone signal, leading to a larger reduction in forecast error. The information environment can moderate signalling effectiveness. This shows that managerial tone represents a reliable signalling device for transmitting latent information on a firm’s quality and future performance and that receivers can understand this signal correctly. This study highlights the signalling role of managerial tone in managers and analysts’ communication
The Miracle of Morgan’s Creek (1944): three perspectives on Preston Sturges and the Production Code
Get PDFIdentifying weather patterns responsible for renewable energy droughts over India
Get PDFEnergy systems across the globe are evolving to meet climate mitigation targets. This requires rapid reductions in fossil fuel consumption and significant uptake of renewable generation. Renewable energy sources are weather-dependent, causing production to vary at timescales from minutes to decades ahead. A consequence of this variability is that there will be periods of low renewable energy production, here termed renewable energy droughts. This energy security challenge needs to be addressed to ensure grid stability. India is chosen as a study area as it is a region that has both a large proportion of renewable generation and good subseasonal predictability.
In this study, we use synthetic wind and solar photovoltaic production timeseries, previously derived for the Indian energy grid using ERA5 reanalysis from 1979–2022, to identify historical renewable energy droughts. These are defined as periods where wind and solar potential is in the lowest 2.5% compared to climatology. These events commonly occur from November–February, with the longest historical event being nine days long.
We identify the weather regimes that cause the largest renewable energy droughts over India and investigate potential sources of predictability. Existing large-scale daily weather types and impact-based patterns are used to investigate the different weather patterns causing renewable energy droughts. Renewable energy droughts are caused by low seasonal wind speeds in combination with weather patterns bringing high cloud cover. These are mainly weak northeast monsoon and western disturbances.
Sources of potential subseasonal predictability are considered for the largest renewable energy droughts, including the Madden Julian Oscillation and Boreal Summer Intraseasonal Oscillation. Although both have a stronger relationship with high energy potential days, links between phases of these two oscillations and renewable energy drought days are identified. These could help to provide early warnings for challenging security of supply conditions in the future
What makes a task difficult? Pre-service teacher analysis of task difficulty
Get PDFTwo conceptual models of Task Complexity, Cognition Hypothesis (Robinson, 2001, 2007) and Limited Attentional Capacity (Skehan, 1998; 2003; 2018) have been proposed and widely debated in the task-based language teaching (TBLT) literature. However, little empirical evidence exists to suggest either of the models is based on teacher input or being used by teachers for classroom use. Drawing on pre-service teacher analysis of task difficulty, the study aimed to develop an in-depth understanding of task features they consider when evaluating task difficulty. Participants, 127 pre-service teachers at the end of their one-year MA TESOL program in Ontario, Canada, evaluated two sets of sample tasks, ranking them according to their degree of difficulty and identifying the features that contributed to this difficulty. 727 pieces of raw data, extracted from the task difficulty analysis, were categorized. Five main categories of task difficulty were identified, namely 1) linguistic demand, 2) cognitive operational demand, 3) design features, 4) informational demand, and 5) communicative demand. Learner related factors, external to task design, were also suggested as issues related to difficulty. We propose a set of task difficulty features that can be used in replication and validation studies to help with the development of a teacher evidence-based model of task difficulty
Patriarchy and the pandemic: housework allocation among dual-earner couples in India
No full textUnpaid housework done by men and women in dual-earner households goes to the heart of
gender inequality. We explore this issue for urban India during the COVID-19 lockdown when
work from home spiked and housework increased. We examine the extent to which women’s
responsibility for housework and help given by partners changed during lockdown and any
systematic differences in chores done by men and women. We conceptualize and empirically
measure base household-level patriarchy. This helps distill ‘real’ shifts in the gendered division
of housework during the lockdown. Gender norms, access to domestic help, and women’s
income mattered for partners’ willingness to take on additional chores. Although housework
increased for both partners, women did more time-invariant tasks and men more time-variant
tasks. This suggests women had to juggle paid work around domestic responsibilities while
men experienced fewer impinging effects of increases in housework
Development of squamous cell carcinoma at the bite sites several years following suspected cobra (Naja naja) envenomings
Get PDFIntroduction: Snakebite envenoming is a multidimensional issue that causes severe functional and life-challenging consequences among rural communities in tropical countries. Current research and treatments are largely focused on acute envenomation effects and short-term health outcomes. The knowledge of snakebite-induced long-term consequences is highly limited.
Case reports: We report the development of squamous cell carcinoma at the bite site several years later in four patients who are suspected to have been bitten by cobras (Naja naja). Following bites, the victims presented typical symptoms of cobra envenomings including ptosis, altered sensorium and breathing difficulties. However, a difficult-to-heal wound remained a chronic health sequela with frequent desquamation cycles which led to squamous cell carcinoma. Surgery as the primary therapeutic approach was used for all patients to tackle this issue.
Discussion: These cases highlight the significance of squamous cell carcinoma in previously damaged tissue by snakebites as a possible long-term consequence. This emphasises the need for surveillance systems focused on a broad range of snakebite-induced consequences including long-term pathological, psychological, and socioeconomic conditions.
Conclusion: This case collection describes an intriguing pathological complication following cobra bites that requires further research to determine mechanistic and epidemiological insights in the most affected regions by snakebites, specifically India
Targeting cognitive resilience through prebiotics: a focused perspective
Get PDFThis perspective article is a product of the work of an expert group within the Prebiotic Task Force convened by the International Life Sciences Institute Europe (ILSI Europe), a non-profit organization that brings together experts from academia, industry and public service to catalyse nutrition science for public benefit. An expert group was conceived in October 2023 to discuss the evidence base on the use of prebiotics to promote cognitive functioning, with a focus on highlighting knowledge gaps and proposing a list of recommendations to guide this specific area of research forward. To address this, we evaluated existing systematic reviews and meta-analyses of human intervention studies that examine the effects of prebiotics on cognitive functioning. These are predominantly conducted in healthy participants under basal conditions and have, to date, revealed limited effects. In this perspective, we propose that prebiotics should be investigated as agents to promote cognitive resilience by testing their effects on cognitive performance under certain cognition-taxing factors that individuals encounter across their lifespan. These include stress, poor sleep outcomes, sedentary behaviour, and unhealthy dietary patterns, all of which have been shown to be associated with altered microbiome and impact global cognition or specific cognitive domains. In addition, we recommend identifying vulnerable populations that are either sub-clinical or that struggle chronically or periodically with one or more cognition-taxing factors, to better uncover the boundary conditions for prebiotic effectiveness. By broadening the scope of research to include diverse populations and challenging conditions in daily life or experimental settings, we can expand our understanding of the role of prebiotics not only in cognitive health or impairment, but also as potential preventative agents that may promote cognitive resilience during aging and in response to various lifestyle-related challenges
Grazing lambs on a low-input, multispecies pasture for an extended period has no detrimental effect on meat nutritional or sensory quality
Get PDFThere is an increasing interest in low-input, multispecies swards as a sustainable forage for ruminant production, but the impact of grazing these over extended periods of time on meat nutritional quality (fatty acid (FA) profile, trace minerals and oxidisability risk) and sensory properties is unclear. Thirty lambs were grazed for 133 days on either a perennial ryegrass (PRG) or botanically diverse (containing twelve plant species, BD), pasture. The effects on the FA composition of musculus longissimus thoracis (lean and subcutaneous fat), zinc and iron content (lean), glutathione perioxidase (GSH-Px) activity (lean and plasma) and thiobarbituric acid reactive substances (TBARS) content (lean) were determined, and cooked meat was assessed for sensory properties using a trained sensory panel. BD lambs were lighter (P = 0.014) and had a lower weekly live weight gain (P = 0.017) than PRG, which was probably due to the nutritional quality of the pasture. BD pasture increased (P 0.05) on other polyunsaturated FA (PUFA), GSH-Px activity or TBARS content. BD pasture increased (P = 0.038) lean tissue zinc content compared with PRG but did not affect iron (P > 0.05). Pasture type had no impact (P > 0.05) on meat aroma and flavour sensory properties. It was concluded that grazing BD for an extended period did not negatively affect the nutritional and eating quality of lamb meat compared with PRG, and as such is suitable for finishing lambs. In order to benefit economically from including a BD pasture in a lamb finishing system, producers may need to consider an earlier slaughter target weight, depending on live weight gain
A qualitative exploration of change processes relevant to compassion‐focused therapy that occurs when people view both soothing and non‐soothing images
Get PDFObjective Using soothing imagery within psychotherapy may support people to undertake positive visualisation exercises. However, little is known about what processes happen when people view images they find to be soothing or non‐soothing.DesignExploratory qualitative methods were used.MethodResponses from 644 participants who had written about images they found to be soothing or non‐soothing were analysed using thematic analysis.ResultsTwo key themes were developed that related to the importance of the image content (such as it being a natural scene or artificial) and the internal cognitive and psychological processes that it triggered within participants as being key drivers for an image being perceived as soothing or non‐soothing. This included recall of positive autobiographical memories and liking the image content. Conversely, negative autobiographical memories and disliking image content were associated when people viewed images they considered to be non‐soothing.ConclusionsExperiences of feeling soothed when viewing an image appear to be maintained by imagining positive sensory experiences that were associated with the image or linking the image to positive experiences from the participant's autobiographical memory. This has implications for the delivery of therapy using pre‐existing image sets and suggests there is a need to find out what images are most suited for people accessing services