3,614 research outputs found
Computerized adaptive test and decision trees: A unifying approach
In the last few years, several articles have proposed decision trees (DTs) as an alternative to computerized adapted tests (CATs). These works have focused on showing the differences between the two methods with the aim of identifying the advantages of each of them and thus determining when it is preferable to use one method or another. In this article, Tree-CAT, a new technique for building CATs is presented. Unlike the existing work, Tree-CAT exploits the similarities between CATs and DTs. This technique allows the creation of CATs that minimise the mean square error in the estimation of the examinee’s ability level, and controls the item’s exposure rate. The decision tree is sequentially built by means of an innovative algorithmic procedure that selects the items associated with each of the tree branches by solving a linear program. In addition, our work presents further advantages over alternative item selection techniques with exposure control, such as instant item selection or simultaneous administration of the test to an unlimited number of participants. These advantages allow accurate on-line CATs to be implemented even when the item selection method is computationally costly.Numerical experiments were conducted in Uranus, a supercomputer cluster located at Universidad Carlos III de Madrid and jointly funded by EU-FEDER funds and by the Spanish Government via the National Projects No. UNC313-4E-2361, No. ENE2009-12213- C03-03, No. ENE2012-33219, No. ENE2012-31753 and No. ENE2015-68265-P
Silver nanoparticle-cellulose composite for thin-film microextraction of Cd and Pb as dithiocarbamate derivatives followed by inductively-coupled plasma mass spectrometry determination
Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGPreconcentration of Cd and Pb at ultratrace level in waters following filtration through silver nanoparticles-cellulose composites used for thin-film microextraction was performed. The new procedure was based on the formation of pyrrolidine dithiocarbamate (APDC) derivatives, which showed a large affinity toward the AgNPs. For this purpose, cellulose filters modified with AgNPs were prepared in situ upon reduction of silver ions by sodium tetrahydroborate. The effect of several experimental parameters such as the kind of derivatization agent and its concentration, sample pH, desorption conditions and volume of filtered sample was assessed. Cd and Pb were quantitated in the eluates by inductively coupled plasma-mass spectrometry (ICP-MS). Filters were characterized by scanning electron microscopy (SEM) in backscattering electron mode and combined with energy dispersive X-ray spectrometry, showing the presence of Ag and S in the cellulose filter. The repeatability expressed as relative standard deviation (RSD,%) was 1.4% for Cd and 5.8% for Pb. Methodological detection limits were 0.6 and 8.5 ng/L for Cd and Pb, respectively. The method was applied to several environmental waters.Agencia Estatal de Investigación | Ref. RTI2018-093697-B-I0
Resiliencia y estrés académico en estudiantes de una universidad privada de Lima Metropolitana durante el 2022
La presente investigación tiene como objetivo general determinar el tipo de correlación que existe entre resiliencia y estrés académico en estudiantes de una Universidad privada durante el 2022. El presente estudio se realizó bajo un enfoque cuantitativo, de tipo correlacional, diseño no experimental, corte transversal, aplicado en 409 estudiantes universitarios. Se aplicaron los instrumentos de la escala breve de resiliencia Connor-Davidson CD-RISC 10 (2007) validada en el año 2022, y el Inventario Sistémico Cognoscitivista para el estudio de Estrés Académico SISCO SV-21 validada en el año 2018, ambos instrumentos validados en el Perú. Con relación a los resultados de esta investigación, se obtuvo una correlación de tipo inversa y fuerza moderada con un Rho de Spearman, rho = -,410 y una significancia p = .000, indicando que a mayor resiliencia menor estrés académico perciben los estudiantes universitarios. Se tuvo como limitación en la investigación que una parte de la muestra contestó a las escalas sin la presencia de los investigadores, lo que no da la certeza que lo hayan respondido en un momento de concentración o atención a la escala, si no que quizá en otro momento donde se deje fácilmente distraer por estímulos externos.The general objective of this research is to determine the type of correlation between resilience and academic stress in students of a private university in 2022. The present study was conducted under a quantitative, correlational, non-experimental, cross-sectional design, applied to 409 university students. The Connor-Davidson Brief Resilience Scale CD-RISC 10 (2007) validated in 2022, and the Systemic Cognitive Inventory for the Study of Academic Stress SISCO SV-21 validated in 2018, both instruments validated in Peru, were applied. Regarding the results of this research, a correlation of inverse type and moderate strength was obtained with a Spearman's rho, rho = -.410 and a significance p = .000, indicating that the higher the resilience the lower the academic stress perceived by university students. A limitation of the research was that part of the sample answered the scales without the presence of the researchers, which does not give the certainty that they answered in a moment of concentration or attention to the scale, but perhaps in another moment where they were easily distracted by external stimuli
Multi-product biorefinery from Arthrospira platensis biomass as feedstock for bioethanol and lactic acid production
With the aim to reach the maximum recovery of bulk and specialty bioproducts while minimizing waste generation, a multi-product biorefinery for ethanol and lactic acid production from the biomass of cyanobacterium Arthrospira platensis was investigated. Therefore, the residual biomass resulting from different pretreatments consisting of supercritical fluid extraction (SF) and microwave assisted extraction with non-polar (MN) and polar solvents (MP), previously applied on A. platensis to extract bioactive metabolites, was further valorized. In particular, it was used as a substrate for fermentation with Saccharomyces cerevisiae LPB-287 and Lactobacillus acidophilus ATCC 43121 to produce bioethanol (BE) and lactic acid (LA), respectively. The maximum concentrations achieved were 3.02 ± 0.07 g/L of BE by the MN process at 120 rpm 30 °C, and 9.67 ± 0.05 g/L of LA by the SF process at 120 rpm 37 °C. An economic analysis of BE and LA production was carried out to elucidate the impact of fermentation scale, fermenter costs, production titer, fermentation time and cyanobacterial biomass production cost. The results indicated that the critical variables are fermenter scale, equipment cost, and product titer; time process was analyzed but was not critical. As scale increased, costs tended to stabilize, but also more product was generated, which causes production costs per unit of product to sharply decrease. The median value of production cost was US 0.39, for BE and LA, respectively, supporting the concept of cyanobacterium biomass being used for fermentation and subsequent extraction to obtain ethanol and lactic acid as end products from A. platensis
Lesão dermo-hemorrágica em um canino compatível com loxoscelismo. Relato de um caso
Accidents caused by Loxosceles spiders are important in Veterinary Medicine due to the severity of the injury they cause and the possible systemic complications that can lead to the animal’s death. However, there are few epidemiological records. This is why it is necessary to generate basic knowledge to consider loxoscelism as a possible condition, to generate an early diagnosis from clinical data and anamnesis, with the identification of the animal that caused the accident when it is possible. The present study aims to describe the evolution of the lesions probably caused by Loxosceles sp. poisoning in a 6-year-oldfemale canine, 7 kg, Fox Terrier breed, received at the Small Animal School Hospital of Veterinary Sciences Faculty, UNLPam. Lesions were observed on the left ocular conjunctiva, with evident bleeding, left upper lip with swelling and hematoma also with bleeding; edema and bruising of hind limbs in the popliteal and thigh regions. Laboratory studies showed hemolytic anemia and coagulopathy signs. The animal was treated with specific antivenom, fresh whole blood transfusion, corticosteroids, and antibiotics. Based on the clinical data and the evidence of the presence of Loxosceles sp. in the house (ootheca and molts), it is conjectured that this could be a case of dermo-hemolytic loxoscelism, with favorable evolution of the patient one week later, despite the severity of the case.Los accidentes provocados por arañas del género Loxosceles son importantes en Medicina Veterinaria por la gravedad de la lesión que ocasionan y las posibles complicaciones sistémicas que pueden llevar a la muerte del animal. Sin embargo, existen pocos registros epidemiológicos. Por ello surge la necesidad de difundir los conocimientos básicos para pensar en loxoscelismo ante un cuadro compatible, y para realizar un diagnóstico temprano a partir de los datos clínicos y la anamnesis, con la identificación del animal causante del accidente cuando fuese posible. El presente trabajo tiene como objetivo describir la evolución de las lesiones probablemente causadas por envenenamiento de Loxosceles sp. en un canino hembra, raza Fox Terrier, de 6años, 7 kg, atendida en el servicio de Guardia del Hospital Escuela de Animales Pequeños de la Facultad de Ciencias Veterinarias UNLPam. Se observaron lesiones en la conjuntiva ocular izquierda, con sangrado evidente, labio superior del mismo lado con franca edematización y hematoma también con sangrado; edema y hematomas en miembros posteriores en la región poplítea y del muslo. Los resultados de laboratorio evidenciaron signos de anemia hemolítica y coagulopatía. El animal fue tratado con antiveneno específico, transfusión de sangre entera fresca, corticoides y antibióticos. Por los datos clínicos y las evidencias de la presencia de Loxosceles sp. en el domicilio (ootecas y mudas), se conjetura que el envenenamiento canino sería un caso de loxoscelismo dermo-hemolítico, con evolución favorable del paciente al cabo de una semana a pesar de la gravedad del mismo.Os acidentes causados por aranhas do gênero Loxosceles são importantes na Medicina Veterinária pela gravidade das lesões que causam e pelas possíveis complicações sistêmicas que podem levar à morte do animal. No entanto, existem poucos registros epidemiológicos.Por isso, surge a necessidade de disseminar os conhecimentos básicos para pensar em loxoscelismo diante de um quadro compatível e para realizar um diagnóstico precoce com base em dados clínicos e anamnese, com a identificação do animal causador do acidente quando possível. O presente trabalho tem como objetivo descrever a evolução das lesões provavelmente causadas por envenenamento por Loxosceles sp. em um canino fêmea da raça Fox Terrier, 6 anos, 7 kg, atendida no Serviço de Emergência do Hospital Escola de Pequenos Animais da Faculdade de Ciências Veterinárias da UNLPam. As lesões foram observadas na conjuntiva ocular esquerda, com sangramento evidente, lábio superior do mesmo lado com edema acentuado e hematoma também com sangramento; edema e hematomas dos membros posteriores na região poplítea e da coxa. Os resultados laboratoriais mostraram sinais de anemia hemolítica e coagulopatia. O animal foi tratado com antiveneno específico, transfusão de sangue total fresco, corticoides e antibióticos. Pelos dados clínicos e as evidências da presença de Loxosceles sp. no domicílio (ootecas e mudas), conjetura-se que o envenenamento canino seria um caso de loxoscelismo dermo-hemolítico, com evolução favorável do paciente após uma semana, apesar de sua gravidade
The return to nature in the Austrian radical thinking: the case of Gunther Domenig
This paper discusses the inclusion of nature in the utopian vision of the radical movements of the 60s and 70s. In particular, it presents the Austrian radicals as the first and main supporters towards the aforementioned tendency. The introduction of nature in the built environment is a feature of Austrian radicalism since its first generation which includes authors such as Raimund Abraham, Walter Pichler, Hans Hollein and Gunther Domenig. The latter is taken here presented as the main representative of this current on the architectonic scale. Three of his works are described in the text to represent three different declinations of this trend towards biomimicry
Risk of Cognitive Impairment in Patients With Parkinson’s Disease With Visual Hallucinations and Subjective Cognitive Complaints
Cognitive impairment; Parkinson's disease; Visual hallucinationsDeterioro cognitivo; Enfermedad de Parkinson; Alucinaciones visualesDeteriorament cognitiu; Malaltia de Parkinson; Al·lucinacions visualsBackground and Purpose
Visual hallucinations (VH) and subjective cognitive complaints (SCC) are associated with cognitive impairment (CI) in Parkinson’s disease. Our aims were to determine the association between VH and SCC and the risk of CI development in a cohort of patients with Parkinson’s disease and normal cognition (PD-NC).
Methods
Patients with PD-NC (total score of >80 on the Parkinson’s Disease Cognitive Rating Scale [PD-CRS]) recruited from the Spanish COPPADIS cohort from January 2016 to November 2017 were followed up after 2 years. Subjects with a score of ≥1 on domain 5 and item 13 of the Non-Motor Symptoms Scale at baseline (V0) were considered as “with SCC” and “with VH,” respectively. CI at the 2-year follow-up (plus or minus 1 month) (V2) was defined as a PD-CRS total score of <81.
Results
At V0 (n=376, 58.2% males, age 61.14±8.73 years [mean±SD]), the frequencies of VH and SCC were 13.6% and 62.2%, respectively. VH were more frequent in patients with SCC than in those without: 18.8% (44/234) vs 4.9% (7/142), p<0.0001. At V2, 15.2% (57/376) of the patients had developed CI. VH presenting at V0 was associated with a higher risk of CI at V2 (odds ratio [OR]=2.68, 95% confidence interval=1.05–6.83, p=0.0.039) after controlling for the effects of age, disease duration, education, medication, motor and nonmotor status, mood, and PD-CRS total score at V0. Although SCC were not associated with CI at V2, presenting both VH and SCC at V0 increased the probability of having CI at V2 (OR=3.71, 95% confidence interval=1.36–10.17, p=0.011).
Conclusions
VH were associated with the development of SCC and CI at the 2-year follow-up in patients with PD-NC.The resources obtained for the development of this project have been obtained by the Degen Foundation (https://fundaciondegen.org/). A part of the Project is financed with grants from the Spanish Ministry of Economy and Competitiveness [PI16/01575] co-founded by ISCIII (Concesión de subvenciones de Proyectos de Investigación en Salud de la convocatoria 2020 de la Acción Estratégica en Salud 2017-2020 por el proyecto “PROGRESIÓN NO MOTORA E IMPACTO EN LA CALIDAD DE VIDA EN LA ENFERMEDAD DE PARKINSON”)
Data preprocessing workflow for exhaled breath analysis by GC/MS using open sources
© 2020 The Authors. This document is made available under the CC-BY 4.0 license. http://creativecommons.org/licenses/by /4.0/
This document is the Accepted version of a Published Work that appeared in final form in Scientifc Reports. To access the final edited and published work see https://doi.org/10.1038/s41598-020-79014-
Air pollution Analysis with a PFCM Clustering Algorithm Applied in a Real Database of Salamanca (Mexico)
Over the last ten years, Salamanca has been considered among the most polluted cities in México. Nowadays, there is an Automatic Environmental Monitoring Network (AEMN) which measures air pollutants (Sulphur Dioxide (SO2), Particular Matter (PM10), Ozone (O3), etc.), as well as environmental variables (wind speed, wind direction, temperature, and relative humidity), and it takes a sample of the variables every minute. The AEM Network is mainly based on three monitoring stations located at Cruz Roja, DIF, and Nativitas. In this work, we use the PFCM (Possibilistic Fuzzy c Means) clustering algorithm as a mean to get a combined measure, from the three stations, looking to provide a tool for better management of contingencies in the city, such that local or general action can be taken in the city according to the pollution level given by each station and the combined measure. Besides, we also performed an analysis of correlation between pollution and environmental variables. The results show a significative correlation between pollutant concentrations and some environmental variables. So, the combined measure and the correlations can be used for the establishment of general contingency thresholds
Efficacy and Safety of Colchicine in Post-acute Myocardial Infarction Patients : A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Background: Inflammation plays a key role in atherosclerotic plaque destabilization and adverse cardiac remodeling. Recent evidence has shown a promising role of colchicine in patients with coronary artery disease. We evaluated the efficacy and safety of colchicine in post-acute myocardial infarction (MI) patients. Methods: We searched five electronic databases from inception to January 18, 2021, for randomized controlled trials (RCTs) evaluating colchicine in post-acute MI patients. Primary outcomes were cardiovascular mortality and recurrent MI. Secondary outcomes were all-cause mortality, stroke, urgent coronary revascularization, levels of follow-up high-sensitivity C-reactive protein (hs-CRP), and drug-related adverse events. All meta-analyses used inverse-variance random-effects models. Results: Six RCTs involving 6,005 patients were included. Colchicine did not significantly reduce cardiovascular mortality [risk ratio (RR), 0.91; 95% confidence interval (95% CI), 0.52-1.61; p = 0.64], recurrent MI (RR, 0.87; 95% CI, 0.62-1.22; p = 0.28), all-cause mortality (RR, 1.06; 95% CI, 0.61-1.85; p = 0.78), stroke (RR, 0.28; 95% CI, 0.07-1.09; p = 0.05), urgent coronary revascularization (RR, 0.46; 95% CI, 0.02-8.89; p = 0.19), or decreased levels of follow-up hs-CRP (mean difference, −1.95 mg/L; 95% CI, −12.88 to 8.98; p = 0.61) compared to the control group. There was no increase in any adverse events (RR, 0.97; 95% CI, 0.89-1.07; p = 0.34) or gastrointestinal adverse events (RR, 2.49; 95% CI, 0.48-12.99; p = 0.20). Subgroup analyses by colchicine dose (0.5 vs. 1 mg/day), time of follow-up (30 days) showed no changes in the overall findings. Conclusion: In post-acute MI patients, colchicine does not reduce cardiovascular or all-cause mortality, recurrent MI, or other cardiovascular outcomes. Also, colchicine did not increase drug-related adverse event
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