122 research outputs found

    Comparison of corneal thickness measurement with the Pentacam, the PARK1 and an ultrasonic pachymeter

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    Purpose: The aim was to determine the agreement between PARK1 pachymetric readings and measurements made with the Pentacam and ultrasonic pachymetry. Methods: In this prospective study, we enrolled refractive surgery patients free of other ocular conditions and performed Pentacam and PARK1 acquisitions followed by ultrasonic pachymetry. We recorded pachymetric readings on the centre, apex and thinnest point with the Pentacam, corneal thickness values of the apex and minimum readings from the PARK1, and the central corneal thickness with the ultrasonic system. Data were compared using t-tests, and the Pearson correlations and 95 limits of agreement (LoA) of all pairs were determined. Results: The mean age of the 47 participants was 32 ± 10.4years and data from their right eyes were used. Overall, ultrasonic measurements were significantly higher than all readings from the PARK1 and the Pentacam. The smallest difference was between the PARK-apex and Pentacam-apex readings (0.2 ± 11μm); the 95 LoA of this pair gave a width of 43.7μm (-21.7 to 22.0μm). The smallest width pertained to the Pentacam-centre and ultrasound-centre paired readings; the width was 32.5μm (-21.8 to 11.8μm), while the mean difference was -5.54 ± 8μm. Conclusion: The PARK1 measurements of the apical corneal thickness can be a substitute for central corneal pachymetry with an ultrasonic device, provided that the range of agreement is taken into consideration in the interpretation of the results. Similar studies on populations with different corneal conditions such as keratoconus are needed. © 2011 Optometrists Association Australia

    SHAPS-C: the Snaith-Hamilton pleasure scale modified for clinician administration

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    Anhedonia, a diminished or lack of ability to experience and anticipate pleasure represents a core psychiatric symptom in depression. Current clinician assessment of anhedonia is generally limited to one or two all-purpose questions and most well-known psychometric scales of anhedonia are relatively long, self-administered, typically not state sensitive, and are unsuitable for use in clinical settings. A user-friendly tool for a more in-depth clinician assessment of hedonic capacity is needed. The present study assessed the validity and reliability of a clinician administered version of the Snaith-Hamilton Pleasure Scale, the SHAPS-C, in 34 depressed subjects. We compared total and specific item scores on the SHAPS-C, SHAPS (self-report version), Montgomery-Åsberg Depression Rating Scale (MADRS), and the Inventory of Depressive Symptomatology-Self Rating version (IDS-SR). We also examined construct, content, concurrent, convergent, and discriminant validity, internal consistency, and split-half reliability of the SHAPS-C. The SHAPS-C was found to be valid and reliable. The SHAPS and the SHAPS-C were positively correlated with one another, with levels of depression severity, as measured by the MADRS, and the IDS-SR total scores, and with specific items of the MADRS and IDS-SR sensitive to measuring hedonic capacity. Our investigation indicates that the SHAPS-C is a user friendly, reliable, and valid tool for clinician assessment of hedonic capacity in depressed bipolar and unipolar patients

    Evaluating functional brain organization in individuals and identifying contributions to network overlap

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    Individual differences in the spatial organization of resting-state networks have received increased attention in recent years. Measures of individual-specific spatial organization of brain networks and overlapping network organization have been linked to important behavioral and clinical traits and are therefore potential biomarker targets for personalized psychiatry approaches. To better understand individual-specific spatial brain organization, this paper addressed three key goals. First, we determined whether it is possible to reliably estimate weighted (non-binarized) resting-state network maps using data from only a single individual, while also maintaining maximum spatial correspondence across individuals. Second, we determined the degree of spatial overlap between distinct networks, using test-retest and twin data. Third, we systematically tested multiple hypotheses (spatial mixing, temporal switching, and coupling) as candidate explanations for why networks overlap spatially. To estimate weighted network organization, we adopt the Probabilistic Functional Modes (PROFUMO) algorithm, which implements a Bayesian framework with hemodynamic and connectivity priors to supplement optimization for spatial sparsity/independence. Our findings showed that replicable individual-specific estimates of weighted resting-state networks can be derived using high-quality fMRI data within individual subjects. Network organization estimates using only data from each individual subject closely resembled group-informed network estimates (which was not explicitly modeled in our individual-specific analyses), suggesting that cross-subject correspondence was largely maintained. Furthermore, our results confirmed the presence of spatial overlap in network organization, which was replicable across sessions within individuals and in monozygotic twin pairs. Intriguingly, our findings provide evidence that overlap between 2-network pairs is indicative of coupling. These results suggest that regions of network overlap concurrently process information from both contributing networks, potentially pointing to the role of overlapping network organization in the integration of information across multiple brain systems

    The distribution of ocular biometry in Iranian school children

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    Purpose: To determine the distribution of axial length (AL), vitreous chamber depth (VCD), anterior chamber depth (ACD), lens thickness (LT), lens power (LP), radius of curvature (CR), and white-to-white corneal diameter (WTW) in the 14-20 year age range. Methods: In a cross-sectional study, sampling was done from Aligoodarz high schools using multistage simple cluster sampling. For all students, visual acuity and non-cycloplegic refraction tests were performed. Biometric components were measured using Allegro Biograph (WaveLight AG, Erlangen, Germany). Results: In this report, data from 434 cases was used in the analysis; of these 222 (51.2) were females. Mean and 95 confidence intervals of AL, VCD, ACD, LT, LP, CR, and WTW in the studied sample were 23.4 mm (23.32 to 23.48), 16.82 mm (16.74 to 16.9), 3.14 mm (3.12 to 3.16), 3.44 mm (3.42 to 3.46), 22.65 diopter (22.47 to 22.83), 7.74 mm (7.72 to 7.76), and 12.26 mm (12.22 to 12.3), respectively. In the multiple regression model, AL, VCD, ACD, CR, and WTW was significantly higher in boys while mean LT and LP were significantly higher in girls. The distributions of AL, ACD, LT, and CR were significantly different from normal. The distributions of AL, LT, and CR were leptokurtic, unlike ACD which had a platykurtic distribution pattern. Conclusion: In this report, we describe the normal ranges of ocular biometric components in a sample population of 14-20 year old Iranians. ACD in this study was shorter and WTW was larger than previous studies and other components were in the midrange. More studies throughout Iran are needed to verify a shorter ACD and larger WTW. All components of ocular biometry showed significant inter-gender differences. © 2014 by the Iranian Society of Ophthalmology

    ALONE: A Dataset for Toxic Behavior among Adolescents on Twitter

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    The convenience of social media has also enabled its misuse, potentially resulting in toxic behavior. Nearly 66% of internet users have observed online harassment, and 41% claim personal experience, with 18% facing severe forms of online harassment. This toxic communication has a significant impact on the well-being of young individuals, affecting mental health and, in some cases, resulting in suicide. These communications exhibit complex linguistic and contextual characteristics, making recognition of such narratives challenging. In this paper, we provide a multimodal dataset of toxic social media interactions between confirmed high school students, called ALONE (AdoLescents ON twittEr), along with descriptive explanation. Each instance of interaction includes tweets, images, emoji and related metadata. Our observations show that individual tweets do not provide sufficient evidence for toxic behavior, and meaningful use of context in interactions can enable highlighting or exonerating tweets with purported toxicity.Comment: Accepted: Social Informatics 202

    Investigating charge-up and fragmentation dynamics of oxygen molecules after interaction with strong X-ray free-electron laser pulses

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    During the last decade, X-ray free-electron lasers (XFELs) have enabled the study of light–matter interaction under extreme conditions. Atoms which are subject to XFEL radiation are charged by a complex interplay of (several subsequent) photoionization events and electronic decay processes within a few femtoseconds. The interaction with molecules is even more intriguing, since intricate nuclear dynamics occur as the molecules start to dissociate during the charge-up process. Here, we demonstrate that by analyzing photoelectron angular emission distributions and kinetic energy release of charge states of ionic molecular fragments, we can obtain a detailed understanding of the charge-up and fragmentation dynamics. Our novel approach allows for gathering such information without the need of complex ab initio modeling. As an example, we provide a detailed view on the processes happening on a femtosecond time scale in oxygen molecules exposed to intense XFEL pulses

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly
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