The Computer-Vision Symptom Scale (CVSS17): Development and Initial Validation

Purpose.: To develop a questionnaire (in Spanish) to measure computer-related visual and ocular symptoms (CRVOS). Methods.: A pilot questionnaire was created by consulting the literature, clinicians, and video display terminal (VDT) workers. The replies of 636 subjects completing the questionnaire were assessed using the Rasch model and conventional statistics to generate a new scale, designated the Computer-Vision Symptom Scale (CVSS17). Validity and reliability were determined by Rasch fit statistics, principal components analysis (PCA), person separation, differential item functioning (DIF), and item–person targeting. To assess construct validity, the CVSS17 was correlated with a Rasch-based visual discomfort scale (VDS) in 163 VDT workers, this group completed the CVSS17 twice in order to assess test-retest reliability (two-way single-measure intraclass correlation coefficient [ICC] and their 95% confidence intervals, and the coefficient of repeatability [COR]). Results.: The CVSS17 contains 17 items exploring 15 different symptoms. These items showed good reliability and internal consistency (mean square infit and outfit 0.88–1.17, eigenvalue for the first residual PCA component 1.37, person separation 2.85, and no DIF). Pearson's correlation with VDS scores was 0.60 (P < 0.001). Intraclass correlation coefficient for test–retest reliability was 0.849 (95% confidence interval [CI], 0.800–0.887), and COR was 8.14. Conclusions.: The Rasch-based linear-scale CVSS17 emerged as a useful tool to quantify CRVOS in computer workers

Feasibility of recycling CDW as raw material in gypsum composites

On average, Europe generates around 890 million tonnes of Construction and Demolition Waste (CDW) per year and only 50% of this CDW is recycled. This is far from the objectives determined in the European Directive for 2020 and aware of this situation, the European Countries are implementing national policies to prevent the waste that can be avoidable and to promote measures to increase recycling and recovering. In Spain, one of these measures has been the development of a CDW recycling guide for the manufacture of mortar, concrete, brick and lightweight aggregates

Leptospirosis Presenting as Diffuse Alveolar Hemorrhage

Diffuse alveolar hemorrhage (DAH) syndrome has a mortality rate of 30 to 60%. A 15-year-old male patient presented with a seven-day abdominal pain, vomiting, non-dysenteric diarrhea, conjunctival injection, and fever. Chest radiography revealed bilateral interstitial infiltrates predominating in the lower left lobe. The patient’s condition worsened within hours, with the development of massive hemoptysis, acute respiratory distress syndrome (ARDS), arterial hypotension, and hematocrit decline requiring mechanical ventilation. A chest computed tomography (CT) showed ground-glass opacities with consolidation areas in lower lobes, diffuse tree-in-bud opacities, and centrilobular nodules. A bronchoscopy was conducted without endoluminal lesions and bronchoalveolar lavage (BAL) consistent with alveolar hemorrhage. DAH was diagnosed, and the patient received therapy with intravenous methylprednisolone. The outcome of treatment was successful after eight days of mechanical ventilation. Leptospirosis was diagnosed by serology after discharge. The laboratory findings were normal, and a chest CT scan showed the resolution of the infiltrates. Early recognition of severe hemorrhagic pulmonary syndrome, which has a high mortality rate, is crucial. Therefore, leptospirosis should be suspected as a differential diagnosis in every patient with alveolar hemorrhage, ARDS manifestations, and epidemiological factors

Microbiological effects of an antiseptic mouthrinse in irradiated cancer patients

Objective: To assess the microbiological effects of an antiseptic, non-alcohol based mouth-rinse containing chlorhexidine and cetylpyridinium chloride, in patients undergoing radiation therapy for head-and-neck cancer. Study Design: This was a parallel, double-blind, prospective, randomized clinical trial, including patients irradiated as part of the therapy of head-and-neck cancer, aged 18-75, with at least 10 teeth, and willing to sign an informed consent. Cancer patients were randomly assigned to one of the two treatments (test mouth-rinse or a placebo). Three visits were scheduled (baseline, 14 and 28 days). Microbiological findings were evaluated in tongue, mucosa and subgingival samples, by means of culture. Microbiological variables were assessed by means of the Mann-Whitney, Wilcoxon and chi-square tests. Results: 70 patients were screened and 36 were included. The detection of Candida species in mucosa and tongue samples showed significant reductions in the test group. Total bacterial counts decreased in both groups from baseline to the 2-week visit, while minor changes occurred between 2 and 4 weeks (effects on P. gingivalis, P. intermedia, C. rectus, E. corrodens). Conclusions: Within the limitations of the small sample size, this study suggests that the use of the tested mouth-rinse may lead to improvements in microbiological parameters in patients irradiated for head-and-neck cancer. © Medicina Oral S. L

Mucositis in irradiated cancer patients : effects of an antiseptic mouthrinse

Objective: To assess the effects of an antiseptic, non-alcohol based mouth-rinse containing chlorhexidine and cetylpyridinium chloride, in preventing the oral complications associated to radiation therapy in head-and-neck cancer patients. Study design: This was a parallel, double blind, prospective, randomized clinical trial. Cancer patients were randomly assigned to one of the two treatments (test mouth-rinse or a placebo). Three visits were scheduled (baseline, 14 and 28 days). Different outcome variables were evaluated: mucositis, plaque and gingival indices, stimulated saliva and salivary pH. Results: 70 patients were screened and 36 were included. The presence and the degree of mucositis significantly increased in both groups and no significant differences were detected between groups, although the median increase in the placebo group (1.81) at 2 weeks was higher than in the test group (1.20). Conclusions: Within the limitations of the small sample size, this study suggests that the use of the tested mouthrinse may lead to some improvements in clinical parameters in patients irradiated for head-and-neck cancer

Microburst detection with the WRF model: effective resolution and forecasting indices

Microbursts are meteorological phenomena in the lower troposphere which can produce damaging surface winds and pose a severe risk to aircraft flying close to the ground. As these events usually span less than 4 km and 15 min, the spatiotemporal resolution is a challenge for numerical simulations. Although research of microburst using operative mesoscale models is scarce, the Weather Research and Forecasting (WRF) model has been used in the diagnosis of this phenomenon. In this paper, such model is used to simulate several microburst conducive days using two different boundary conditions. The energy spectra of the simulations are computed to evaluate the effective resolution of the model. The results are in line with previous studies and produce no notable differences among the boundary conditions. Nonetheless, the energy spectra show an overenergetic troposphere at microscale resolutions, rendering the effective resolution inadequate for microburst forecasting using the simulated physics variables. Thus, mesoscale indices are analyzed as a prognostic tool. The wind index, the wet microburst severity index and the microburst windspeed potential index do not show high forecasting performances, even though improving the results of climatology. Also, notable differences among the boundary conditions can be seen. The most consistent results are achieved by the wet microburst severity index

A new miocene–pliocene ichnotaxon for vermetid anchoring bioerosion structures

A revision of Renichnus arcuatus Mayoral, 1987, the vermetid attachment etching trace fossil (fixichnia), is presented here with an emended diagnosis. Renichnus arcuatus should be used only for nested reniform depressions arranged in linear series or solitary ones. A new ichnotaxon, Santichnus mayorali ichnogen. et ichnosp. nov., is described to name a bioerosion structure that previous authors included under R. arcuatus. The new trace fossil comes from the Miocene–Pliocene deposits from Fuerteventura and Lanzarote, Canary Islands, and is characterized as a shallow canal, semicircular in cross-section that occurs on the surface of hard substrates. Santichnus mayorali follows a logarithmic spiral path that may depart in its outer whorl in a somewhat straight shaft that becomes recurved back toward the spiral. From an actualistic point of view, this new ichnotaxon is interpreted as the anchorage bioerosion structure of vermetid gastropods. Given the close relationship between the two ichnotaxa (Renichnus and Santichnus) that share vermetid gastropods as their tracemakers, it is proposed that they should be considered as compound trace fossils when they occur interconnected

Symptoms associated with reading from a smartphone in conditions of light and dark

Asthenopia symptoms were investigated in visually-normal subjects without computer-related vision symptoms after prolonged reading from: smartphone versus hardcopy under photopic conditions, and smartphone in conditions of ambient versus dark room illumination. After reading from the smartphone, total symptom scores and nine out of ten questionnaire symptoms were significantly worse than for the hardcopy (“blurred vision while viewing the text, “blurred distance vision after the task”, “difficulty in refocusing from one distance to another”, “irritated or burning eyes”, “dry eyes”, “eyestrain”, “tired eyes”, “sensitivity to bright lights” and “eye discomfort”). Mean total symptom scores and scores for “irritated or burning eyes” and “dry eyes” were significantly higher for the dark versus photopic conditions. In conclusion, prolonged smartphone reading could cause worse asthenopic symptoms than reading from a hardcopy under similar conditions. Symptoms could be even worse when reading from a smartphone in the dark

Five levels of performance and two subscales identified in the computer-vision symptom scale (CVSS17) by Rasch, factor, and discriminant analysis

Purpose: To quantify the levels of performance (symptom severity) of the computer-vision symptom scale (CVSS17), confirm its bifactorial structure as detected in an exploratory factor analysis, and validate its factors as subscales. Methods: By partial credit model (PCM), we estimated CVSS17 measures and the standard error for every possible raw score, and used these data to determine the number of different performance levels in the CVSS17. In addition, through discriminant analysis, we checked that the scale's two main factors could classify subjects according to these determined levels of performance. Finally, a separate Rasch analysis was performed for each CVSS17 factor to assess their measurement properties when used as isolated scales. Results: We identified 5.8 different levels of performance. Discriminant functions obtained from sample data indicated that the scale's main factors correctly classified 98.4% of the cases. The main factors: Internal symptom factor (ISF) and external symptom factor (ESF) showed good measurement properties and can be considered as subscales. Conclusion: CVSS17 scores defined five different levels of performance. In addition, two main factors (ESF and ISF) were identified and these confirmed by discriminant analysis. These subscales served to assess either the visual or the ocular symptoms attributable to computer use

Comparison of the WRF and HARMONIE models ability for mountain wave warnings

Mountain lee waves usually involve aircraft icing and turbulence events. These weather phenomena, in turn, are a threat to aviation safety. For this reason, mountain lee waves are an interesting subject of study for the scientific community. This paper analyses several mountain lee waves events in the south-east of the Guadarrama mountain range, near the Adolfo Suarez Madrid-Barajas airport (Spain), using the Weather Research and Forecasting (WRF) and the HARMONIE-AROME high-resolution numerical models. For this work, simulated brightness temperature from the optimum WRF parametrization schemes and from the HARMONIE are validated using satellite observations to evaluate the performance of the models in reproducing the lenticular clouds associated to mountain lee waves. The brightness temperature probability density shows interesting differences between both models. Following, a mountain wave characterization is performed simulating some atmospheric variables (wind direction, wind speed, atmospheric stability, liquid water content and temperature) in several grid points located in the leeward, windward and over the summit of the mountains. The characterization results are compared for both numerical models and a decision tree is developed for each to forecast and warn the mountain lee waves, lenticular clouds and icing events with a 24 to 48 h lead time. These warnings are validated using several skill scores, revealing similar results for both models.This work was partially supported by research projects: PID2019- 105306RB-I00, CGL2016-78702-C2-1-R and CGL2016-78702-C2-2-R (SAFEFLIGHT project), FEI-EU-17-16 and SPESMART AND SPESVALE (ECMWF Special Projects). J. Díaz-Fernández acknowledges the grant supported from the MINECO-FPI program (BES-2017)