1,262 research outputs found
Uncertainty in ellipse fitting using a flatbed scanner: development and experimental verification
In the field of dimensional metrology, the use of optical measuring machines requires the handling of a large number of measurement points, or scanning points, taken from the image of the measurand. The presence of correlation between these measurement points has a significant influence on the uncertainty of the result. The aim of this work is the development of an estimation procedure for the uncertainty of measurement in a geometrically elliptical shape, taking into account the correlation between the scanning points. These points are obtained from an image produced using a commercial flat bed scanner. The characteristic parameters of the ellipse (coordinates of the center, semi-axes and the angle of the semi-major axis with regard to the horizontal) are determined using a least squares fit and orthogonal distance regression. The uncertainty is estimated using the information from the auto-correlation function of the residuals and is propagated through the fitting algorithm according to the rules described in Evaluation of Measurement Data—Supplement 2 to the ‘Guide to the Expression of Uncertainty in Measurement’—Extension to any number of output quantities. By introducing the concept of cut-off length, it can be observed how it is possible to take into account the presence of the correlation in the estimation of uncertainty in a very simple way while avoiding underestimation
Regional analysis of climate variability at three time scales and its effect on rainfed maize production in the Upper Lerma River Basin, Mexico
Rainy season use to be from May to September and actually is from June to September. Rainy season use to be from May to September and actually is from June to September. In the region, the most determinant factor for maize crop losses is the water deficit.This study explored climate variability in the Upper Lerma River Basin, State of Mexico, Mexico, at three timescales: annual (1960–2010), monthly (1980–2010) and seasonal (1980–2010). The effects of monthly and seasonal (2003–2010) variability on rainfed maize crops were also evaluated. The variables of rainfall, maximum temperature, minimum temperature and number of hailstorms were interpolated to generate monthly spatial-temporal series. Over a period of 51 years, the climate of the region shows an accumulative annual increase of 131 mm in rainfall and an increase of 0.8 and 0.74 °C in maximum and minimum temperature, respectively. In conclusion, significant changes in the climate variables were found at the three analyzed timescales. Seasonal climate changes were found to coincide with the most vulnerable stage or flowering period of maize; particularly, a shift in the rainfall pattern generates a water deficit that impacts production yield. Hailstorms have increased in frequency, yet their phase shift results in a lesser impact to maize during its most critical stage of development.This study was financed by the Basic Science research project, SEP-CONACYT “Mesoamerican Corn and Scenarios for Local development (El maíz473 mesoamericano y sus escenarios de desarrollo local), No. 130947. The authors also wish to thank the two anonymous reviewers and their comments for improving and restructuring the manuscript in order to highlight the results of this research
Cognitive versus emotional modulation within a Stroop paradigm in patients with schizophrenia
Background: Schizophrenia is a complex disorder involving deficits in both cognitive and emotional processes. Specifically, a marked deficit in cognitive control has been found, which seems to increase when dealing with emotional information.
Aims: With the aim of exploring the possible common links behind cognitive and emotional deficits, two versions of the emotional Stroop task were administered.
Method: In the cognitive-emotional task, participants had to name the ink colour (while ignoring the meaning) of emotional words. In contrast, the emotional-emotional task consisted of emotional words superimposed on emotional faces, and the participants had to indicate the emotional valence of the faces. Fifty-eight participants (29 in-patients diagnosed with schizophrenia and 29 controls) took part in the study.
Results: Patients and controls showed similar response times in the cognitive-emotional task; however, patients were significantly slower than controls in the emotional-emotional task. This result supports the idea that patients show a more pronounced impairment in conflict modulation with emotional content. Besides, no significant correlations between the tasks and positive or negative symptoms were found. This would indicate that deficits are relatively independent of the clinical status of patients. However, a significant correlation between the emotional-emotional task and cognitive symptoms was found.
Conclusions: These findings suggest a restricted capacity of patients with schizophrenia to deal with the attentional demands arising from emotional stimuli.Spanish Ministerio de Ciencia, Innovación y Universidades (PSI2018-098876-B-100Instituto de Salud Carlos III (PI16/00359)Instituto de Salud Carlos III (PI19/00766)5.165 JCR (2021) Q2, 56/155 Psychiatry1.214 SJR (2021) Q1, 106/556 Psychiatry and Mental HealthNo data IDR 2021UE
A power-line communication system governed by loop resonance for photovoltaic plant monitoring
Within this paper, a PLC system that takes advantage of the loop resonance of an entire
DC-PV string configured as a circular signal path is developed and implemented. Low cost
and extremely simple transceivers intended to be installed within each PV module of a string
have been designed and successfully tested. In addition, an anti-saturation coil has been conceived
to avoid saturation of the core when the entire DC current of the string flows through it.
Bi-directional half-duplex communication was successfully executed with up to a 1 MHz carrier
frequency (150 kbps bitrate), using a simple ASK modulation scheme. The transmission and reception
performance are presented, along with the overall system cost in comparison to the previous literature.The Universidad dee Valladolid with the predoctoral contracts of 2020 co-funded by Santander Bank.https://www.mdpi.com/journal/sensorsam2023Electrical, Electronic and Computer Engineerin
The OTELO survey: A case study of [O III] lambda 4959,5007 emitters at z=0.83
Context. The OSIRIS Tunable Filter Emission Line Object (OTELO) survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution.
Aims. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys.
Methods. The selection and analysis procedures of ELS candidates obtained using tunable filter pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF ([O III]), including the main selection biases and uncertainties, are presented.
Results. From 541 preliminary emission-line source candidates selected around z = 0.8, a total of 184 sources were confirmed as [O III] emitters. Consistent with simulations, the minimum detectable line flux and equivalent width in this ELS sample are ∼5 × 10−19 erg s−1 cm2 and ∼6 Å, respectively. We are able to constrain the faint-end slope (α = −1.03 ± 0.08) of the observed LF ([O III]) at a mean redshift of z = 0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84%) of the morphologically classified [O III] ELSs are disc-like sources, and 87% of this sample is comprised of galaxies with stellar masses of M⋆ < 1010 M⊙
Grupo español de cirugía torácica asistida por videoimagen: método, auditoría y resultados iniciales de una cohorte nacional prospectiva de pacientes tratados con resecciones anatómicas del pulmón
Introduction: our study sought to know the current implementation of video-assisted thoracoscopic surgery (VATS) for anatomical lung resections in Spain. We present our initial results and describe the auditing systems developed by the Spanish VATS Group (GEVATS). Methods: we conducted a prospective multicentre cohort study that included patients receiving anatomical lung resections between 12/20/2016 and 03/20/2018. The main quality controls consisted of determining the recruitment rate of each centre and the accuracy of the perioperative data collected based on six key variables. The implications of a low recruitment rate were analysed for '90-day mortality' and 'Grade IIIb-V complications'. Results: the series was composed of 3533 cases (1917 VATS; 54.3%) across 33 departments. The centres' median recruitment rate was 99% (25-75th:76-100%), with an overall recruitment rate of 83% and a data accuracy of 98%. We were unable to demonstrate a significant association between the recruitment rate and the risk of morbidity/mortality, but a trend was found in the unadjusted analysis for those centres with recruitment rates lower than 80% (centres with 95-100% rates as reference): grade IIIb-V OR=0.61 (p=0.081), 90-day mortality OR=0.46 (p=0.051). Conclusions: more than half of the anatomical lung resections in Spain are performed via VATS. According to our results, the centre's recruitment rate and its potential implications due to selection bias, should deserve further attention by the main voluntary multicentre studies of our speciality. The high representativeness as well as the reliability of the GEVATS data constitute a fundamental point of departure for this nationwide cohort
Validation Study Of Genetic Biomarkers Of Response To Tnf Inhibitors In Rheumatoid Arthritis
Genetic biomarkers are sought to personalize treatment of patients with rheumatoid arthritis (RA), given their variable response to TNF inhibitors (TNFi). However, no genetic biomaker is yet sufficiently validated. Here, we report a validation study of 18 previously reported genetic biomarkers, including 11 from GWAS of response to TNFi. The validation was attempted in 581 patients with RA that had not been treated with biologic antirheumatic drugs previously. Their response to TNFi was evaluated at 3, 6 and 12 months in two ways: change in the DAS28 measure of disease activity, and according to the EULAR criteria for response to antirheumatic drugs. Association of these parameters with the genotypes, obtained by PCR amplification followed by single-base extension, was tested with regression analysis. These analyses were adjusted for baseline DAS28, sex, and the specific TNFi. However, none of the proposed biomarkers was validated, as none showed association with response to TNFi in our study, even at the time of assessment and with the outcome that showed the most significant result in previous studies. These negative results are notable because this was the first independent validation study for 12 of the biomarkers, and because they indicate that prudence is needed in the interpretation of the proposed biomarkers of response to TNFi even when they are supported by very low p values. The results also emphasize the requirement of independent replication for validation, and the need to search protocols that could increase reproducibility of the biomarkers of response to TNFi
Mercury exposure and risk of cardiovascular disease: a nested casecontrol study in the PREDIMED (PREvention with MEDiterranean Diet) study
Background: Substantial evidence suggests that consuming 1–2 servings of fish per week, particularly oily fish
(e.g., salmon, herring, sardines) is beneficial for cardiovascular health due to its high n-3 polyunsaturated fatty acid
content. However, there is some concern that the mercury content in fish may increase cardiovascular disease risk,
but this relationship remains unclear.
Methods: The PREDIMED trial included 7477 participants who were at high risk for cardiovascular disease at
baseline. In this study, we evaluated associations between mercury exposure, fish consumption and cardiovascular
disease. We randomly selected 147 of the 288 cases diagnosed with cardiovascular disease during follow-up and
matched them on age and sex to 267 controls. Instrumental neutron activation analysis was used to assess toenail
mercury concentration. In-person interviews, medical record reviews and validated questionnaires were used to
assess fish consumption and other covariates. Information was collected at baseline and updated yearly during
follow-up. We used conditional logistic regression to evaluate associations in the total nested case-control study,
and unconditional logistic regression for population subsets.
Results: Mean (±SD) toenail mercury concentrations (μg per gram) did not significantly differ between cases
(0.63 (±0.53)) and controls (0.67 (±0.49)). Mercury concentration was not associated with cardiovascular disease in
any analysis, and neither was fish consumption or n-3 fatty acids. The fully-adjusted relative risks for the highest
versus lowest quartile of mercury concentration were 0.71 (95% Confidence Interval [CI], 0.34, 1.14; ptrend = 0.37)
for the nested case-control study, 0.74 (95% CI, 0.32, 1.76; ptrend = 0.43) within the Mediterranean diet intervention
group, and 0.50 (95% CI, 0.13, 1.96; ptrend = 0.41) within the control arm of the trial. Associations remained null
when mercury was jointly assessed with fish consumption at baseline and during follow-up. Results were similar
in different sensitivity analyses.Conclusions: We found no evidence that mercury exposure from regular fish consumption increases cardiovascular
disease risk in a population of Spanish adults with high cardiovascular disease risk and high fish consumption. This
implies that the mercury content in fish does not detract from the already established cardiovascular benefits of fish
consumption
Incidence and clearance of anal high-risk human papillomavirus in HIV-positive men who have sex with men: Estimates and risk factors
Background: To estimate incidence and clearance of high-risk human papillomavirus (HR-HPV), and their risk factors, in men who have sex with men (MSM) recently infected by HIV in Spain; 2007-2013. Methods: Multicenter cohort. HR-HPV infection was determined and genotyped with linear array. Two-state Markov models and Poisson regression were used. Results: We analysed 1570 HR-HPV measurements of 612 MSM over 13 608 person-months (p-m) of follow-up. Median (mean) number of measurements was 2 (2.6), median time interval between measurements was 1.1 years (interquartile range: 0.89-1.4). Incidence ranged from 9.0 [95% confidence interval (CI) 6.8-11.8] per 1000 p-m for HPV59 to 15.9 (11.7-21.8) per 1000 p-m for HPV51. HPV16 and HPV18 had slightly above average incidence: 11.9/1000 p-m and 12.8/1000 p-m. HPV16 showed the lowest clearance for both 'prevalent positive' (15.7/1000 p-m; 95% CI 12.0-20.5) and 'incident positive' infections (22.1/1000 p-m; 95% CI 11.8-41.1). More sexual partners increased HR-HPV incidence, although it was not statistically significant. Age had a strong effect on clearance (P-value < 0.001) due to the elevated rate in MSM under age 25; the effect of HIV-RNA viral load was more gradual, with clearance rate decreasing at higher HIV-RNA viral load (P-value 0.008). Conclusion: No large variation in incidence by HR-HPV type was seen. The most common incident types were HPV51, HPV52, HPV31, HPV18 and HPV16. No major variation in clearance by type was observed, with the exception of HPV16 which had the highest persistence and potentially, the strongest oncogenic capacity. Those aged below 25 or with low HIV-RNA- viral load had the highest clearanceThis work was supported by grants from the Fondo de Investigacio´n Sanitaria [PI06/0372, PS09/2181], Red de Investigacio´n en SIDA (RIS) [RD06/006/0026 and RD12/0017/0018 to C.G.] and CIBERESP [group 54A-CB06/02/1009
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