Antisaccadic eye movements in middle-aged individuals with a family history of Alzheimer's disease

BackgroundAntisaccade is closely associated with cognitive ability in Alzheimer's disease (AD). However, studies regarding antisaccade in the early stages of AD are scarce. Considering that first-degree family history is a well-established risk factor for AD, we explored the influence of family history on the performance of antisaccade tasks in individuals with normal cognition.MethodsIn total, 44 participants (aged 50–66 years) with a family history of AD (FH+) and 44 age-, gender-, and educational level-matched controls (FH-) were enrolled in our study. After cognitive assessment using the Montreal Cognitive Assessment and Mini-mental State Examination, participants underwent antisaccade trials, and all parameters were recorded using an eye tracker.ResultsWhile the average velocity was relatively lower in FH+ individuals than in FH− individuals (107.9 ± 14.3°/s vs. 132.9 ± 23.7°/s, p < 0.001), FH+ individuals surprisingly showed relatively fewer uninhibited reflexive saccades (44.7 ± 26.0% vs. 56.2 ± 24.7%, p = 0.037) than the control group. They also required a relatively shorter time to detect and correct false saccades (121.6 ± 40.7 ms vs. 143.9 ± 37.0 ms, p = 0.023).ConclusionsThis study showed that family history is associated with alterations in antisaccadic parameters, suggesting that eye tracking can be used to assess oculomotor control and executive function in individuals at risk of developing dementia

Connection between right-to-left shunt and photosensitivity: a community-based cross-sectional study

BackgroundHypersensitivity to light is a common symptom associated with dysfunction of the occipital region. Earlier studies also suggested that clinically significant right-to-left shunt (RLS) could increase occipital cortical excitability associated with the occurrence of migraine. The aim of this study was to investigate the relationship between RLS and photosensitivity.MethodsThis cross-sectional observational study included the residents aged 18–55 years living in the Mianzhu community between November 2021 and October 2022. Photosensitivity was evaluated using the Photosensitivity Assessment Questionnaire along with baseline clinical data through face-to-face interviews. After the interviews, contrast-transthoracic echocardiography (cTTE) was performed to detect RLS. Inverse probability weighting (IPW) was used to reduce selection bias. Photosensitivity score was compared between individuals with and without significant RLS using multivariable linear regression based on IPW.ResultsA total of 829 participants containing 759 healthy controls and 70 migraineurs were finally included in the analysis. Multivariable linear regression analysis showed that migraine (β = 0.422; 95% CI: 0.086–0.759; p = 0.014) and clinically significant RLS (β = 1.115; 95% CI: 0.760–1.470; p < 0.001) were related to higher photosensitivity score. Subgroup analysis revealed that clinically significant RLS had a positive effect on hypersensitivity to light in the healthy population (β = 0.763; 95% CI: 0.332–1.195; p < 0.001) or migraineurs (β = 1.459; 95% CI: 0.271–2.647; p = 0.010). There was also a significant interaction between RLS and migraine for the association with photophobia (pinteraction = 0.009).ConclusionRLS is associated with photosensitivity independently and might exacerbate photophobia in migraineurs. Future studies with RLS closure are needed to validate the findings.Trial registrationThis study was registered at the Chinese Clinical Trial Register, Natural Population Cohort Study of West China Hospital of Sichuan University, ID: ChiCTR1900024623, URL: https://www.chictr.org.cn/showproj.html?proj=40590

Credit Risky Securities Valuation under a Contagion Model with Interacting Intensities

We study a three-firm contagion model with counterparty risk and apply this model to price defaultable bonds and credit default swap (CDS). This model assumes that default intensities are driven by external common factors as well as other defaults in the system. Using the “total hazard” approach, default times can be generated and the joint density function is obtained. We represent the pricing method of defaultable bonds and obtain the closed-form pricing formulas. By the approach of “change of measure,” analytical solutions of CDS swap rate (swap premuim) are derived in the continuous time framework and the discrete time framework, respectively

Relationship between right‐to‐left shunt, hypoxia, and epilepsy

Abstract Objective A right‐to‐left shunt (RLS) can mediate the hypoxic state, and hypoxemia is relevant for the development of drug‐resistant epilepsy (DRE). The objective of this study was to identify the relationship between RLS and DRE and further investigate the contribution of RLS to the oxygenation state in patients with epilepsy (PWEs). Methods We performed a prospective observational clinical study of PWEs who underwent contrast medium transthoracic echocardiography (cTTE) between January 2018 and December 2021 at West China Hospital. The collected data included demographics, clinical features of epilepsy, antiseizure medications (ASMs), RLS identified by cTTE, electroencephalography (EEG), and magnetic resonance imaging (MRI). Arterial blood gas was also assessed in PWEs with or without RLS. The association between DRE and RLS was quantified using multiple logistic regression, and the parameters of oxygen levels were furtherly analyzed in PWEs with or without RLS. Results A total of 604 PWEs who completed cTTE were included in the analysis, of which 265 were diagnosed with RLS. The proportion of RLS was 47.2% in the group of DRE, and the proportion of RLS was 40.3% in the group of non‐DRE. Having RLS was associated with DRE in multivariate logistic regression analysis (adjusted OR = 1.53, P = 0.045). In the analysis of blood gas, the partial oxygen pressure in PWEs with RLS was lower than those without RLS (88.74 mmHg versus 91.84 mmHg, P = 0.044). Significance Right‐to‐left shunt could be an independent risk factor of DRE, and low oxygenation might be a possible reason

Data_Sheet_1_Antisaccadic eye movements in middle-aged individuals with a family history of Alzheimer's disease.docx

BackgroundAntisaccade is closely associated with cognitive ability in Alzheimer's disease (AD). However, studies regarding antisaccade in the early stages of AD are scarce. Considering that first-degree family history is a well-established risk factor for AD, we explored the influence of family history on the performance of antisaccade tasks in individuals with normal cognition.MethodsIn total, 44 participants (aged 50–66 years) with a family history of AD (FH+) and 44 age-, gender-, and educational level-matched controls (FH-) were enrolled in our study. After cognitive assessment using the Montreal Cognitive Assessment and Mini-mental State Examination, participants underwent antisaccade trials, and all parameters were recorded using an eye tracker.ResultsWhile the average velocity was relatively lower in FH+ individuals than in FH− individuals (107.9 ± 14.3°/s vs. 132.9 ± 23.7°/s, p ConclusionsThis study showed that family history is associated with alterations in antisaccadic parameters, suggesting that eye tracking can be used to assess oculomotor control and executive function in individuals at risk of developing dementia.</p

DEFAULT RISK INSURANCE AND INCOMPLETE MARKETS

This paper uses the existence of secondary markets for debt instruments with default risk (e.g. corporate bonds) to define default insurance along the lines of financial economics. It examines whether, in the case of several risk-neutral measures, characteristics of default can be uniquely determined by the prices of contracts involving default-prone securities. Copyright 1995 Blackwell Publishers.