Analysis of the difficulty of a mathematics test using a componential model

En este trabajo se delimitan los componentes de dificultad que intervienen en la resolución de los ítems de un test de matemáticas que incluye 66 ítems de operaciones con números enteros positivos y negativos. Se estudia el ajuste al modelo de Rasch y se estiman los parámetros de dificultad de los componentes mediante el modelo LLTM de Fischer. Se retuvieron 8 de los 10 componentes propuestos. Los parámetros de dificultad predichos por el modelo LLTM y los estimados mediante el modelo de Rasch obtuvieron una relación lineal positiva elevada (r=0.8783). Los resultados de este estudio preliminar animan a seguir trabajando en el desarrollo de un sistema de Generación Automática de Items (GAI)The components involved in solving a test of mathematics are defined. The test include 66 items of operations with whole (positive and negative) numbers. The fit to Rasch model is studied and the difficulty parameters of components are estimated, using the Fischer LLTM model. 8 of 10 components were retained. A high linear relation was found between both difficulty parameters (r=0.8783). The results of this prior work are understood as a first promising step in order to design an automatic item generation systemEste trabajo ha sido financiado por los proyectos DGICYT PS94-0040 y DGES PB97-004

Analysis of Some Power Quality Parameters at the Points of Common Coupling of Photovoltaic Plants Based on Data Measured by Inverters

With the increasing implementation of renewable energies, the impact that this type of installation can have on the electricity supply grid is of great importance. In this context, the aim of this work is to analyse how the production and injection of electricity generated by a series of small photovoltaic (PV) installations influence some parameters of the electricity grid in the low-voltage (LV) distribution networks to which they are connected, by analysing the basic data provided by the inverters of these installations. The presence of a slight rise in the grid voltage values in the Point of Common Coupling (PCC) as the production of the PV plants increases has been verified, with maximum slopes between 0.95 and 0.00027 V/kW, but which do not result in voltage values close to the limits set by the regulations. In addition to assessing this impact, the results obtained made it possible to determine the hosting capacity that the networks into which these installations inject their energy would have for this type of installation so as not to have a detrimental effect on the voltage values of the grid. The possible influence of the production of PV installations on the voltage imbalance between phases or on the frequency of the grid has also been analysed in this work. Although the values recorded by the inverters have limitations in their measurements that do not make them valid for assessing events such as the presence of harmonics or flickers, they do allow a first analysis to be made of the influence of PV plant production on some grid parameters, without the need to incorporate additional measurement systems in these renewable installations. However, it is important to be aware of the limitations of the measurements of this equipment and, as far as possible, to choose inverter models that carry out this type of measurement as completely as possible

Derechos Fundamentales, Valores y Multiculturismo

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à lei de Direitos Autorais, não disponibilizamos a obra na íntegra. 342.7 D431fA obra afirma que na época atual vive-se um desenvolvimento de multiculturalismo e uma pluralidade de propostas morais nas sociedades. Explica os direiros humanos, individuais, comunitários, políticos e constituicional europeu. Fala da discriminação racial, religiosa e sexual abordando o aspecto político do imigrante e da proteção à mulher

Efecto del tratamiento preoperatorio con estatinas sobre los resultados de la cirugía coronaria

IntroducciónEl uso de estatinas se asocia a una reducción de accidentes coronarios en prevención primaria y secundaria y después de angioplastia primaria.ObjetivoInvestigar si el empleo de estatinas en pacientes sometidos a cirugía de revascularización coronaria (CRC) se asocia a beneficio clínico.MétodosSe incluyeron 102 pacientes consecutivos con enfermedad coronaria para CRC electiva y aislada. En el momento de la inclusión se registró el tratamiento preoperatorio y las variables clínicas basales. En el seguimiento se registró la aparición de muerte de origen cardíaco e infarto agudo de miocardio (IAM) en los primeros 30 días.ResultadosRecibían estatinas 61 pacientes (60%) frente a 41 (40%) que no las recibían. No se encontraron diferencias significativas entre ambas poblaciones respecto a las características basales. A los 30 días se produjo una muerte cardíaca (1,6%) en el grupo que recibió estatinas, frente a cinco (12,2%) en el grupo que no las recibían (p=0,02), el IAM ocurrió en cuatro (6,6%) frente a 8 (19,5%) (p=0,04) y el resultado compuesto de muerte cardíaca o IAM ocurrió en cinco (8,2%) frente a 10 (24,4%) (p=0,02). En un modelo multivariado, el tratamiento preoperatorio con estatinas se mantuvo como un factor independiente de predicción (p=0,01; odds ratio [OR]: 3,6) de la aparición de muerte de causa cardíaca o IAM durante los primeros 30 días después de la intervención.ConclusiónEl tratamiento previo con estatinas se asocia de forma significativa e independiente a un menor riesgo de IAM o muerte de origen cardíaco en pacientes sometidos a CRC.IntroductionStatin treatment diminishes adverse cardiac events both in primary and secondary prevention and also after percutaneous coronary intervention.ObjectiveTo study if preoperative statin treatment is associated with any clinical advantage after coronary artery surgery.MethodsWe enrolled 102 consecutive patients with coronary artery disease, scheduled for elective coronary artery surgery. Combined procedures were excluded. Preoperative treatment and the clinical baseline characteristics were recorded in all patients at inclusion. Cardiac death and acute myocardial infarction (AMI) were recorded during the first 30 days.ResultsSixty one patients (60%) were on preoperative statin treatment vs. 41 (40%) who were not. There were no differences at baseline level between both groups. There was one cardiac death at 30 days (1.6%) in the statin-treatment group vs. five deaths (12.2%) in the nostatin group (p=0.02). Acute myocardial infarction presented in four (6.6%) vs. eight (19.5%) (p=0.04). The primary combined cardiac endpoint made of cardiac death or AMI occurred in five (8.2%) vs. 10 (24.4%) (p=0.02). In a multivariate model, preoperative statin treatment remained an independent predictor (p=0.01; odds ratio [OR] 3.6) of cardiac death or AMI during the first 30 days after surgery.ConclusionPreoperative statin-treatment was significative and independently associated with less risk of AMI or cardiath death in patients who underwent coronary artery bypass grafting

La percepción de la Unión Europea en la elite parlamentaria española. Una primera aproximación

En este trabajo se ofrece un avance de los resultados de la encuesta a elites políticas españolas realizadaen el marco del proyecto IntUne. Tras una sucinta descripción de los objetivos y organizacióngeneral del proyecto, en la que se presta especial atención a la parte dedicada al estudio de las elitesnacionales europeas, se exponen los detalles relativos a la metodología seguida en la elaboraciónde la encuesta en la que se basa este trabajo. A continuación, en lo que constituye la parte principalde esta nota, se realiza una breve exposición de los resultados preliminares de la encuesta en relacióncon las principales percepciones que los miembros de la cámara baja española tienen sobreEuropa y/o sobre el proceso de integración europeo

La percepción de la Unión Europea en la elite parlamentaria española: una primera aproximación

En este trabajo se ofrece un avance de los resultados de la encuesta a elites políticas españolas realizadaen el marco del proyecto IntUne. Tras una sucinta descripción de los objetivos y organizacióngeneral del proyecto, en la que se presta especial atención a la parte dedicada al estudio de las elitesnacionales europeas, se exponen los detalles relativos a la metodología seguida en la elaboraciónde la encuesta en la que se basa este trabajo. A continuación, en lo que constituye la parte principalde esta nota, se realiza una breve exposición de los resultados preliminares de la encuesta en relacióncon las principales percepciones que los miembros de la cámara baja española tienen sobreEuropa y/o sobre el proceso de integración europeo.Proyecto integrado financiado por la Unión Europea a través del Sexto Programa Marco de Investigación (Prioridad 7: Citizens and governance in a knowledge based society) [contrato nº: CIT3-CT-20005-513421]

Analysis of serum proteome after treatment of osteoporosis with anabolic or antiresorptive drugs

The aim of the study was to explore new markers in serum proteome associated with the response to antiosteoporosis drugs, namely teriparatide and denosumab. We obtained serum samples from 14 patients with osteoporosis, both at baseline and after 6 months of treatment with teriparatide (n = 10) or denosumab (n = 4). Samples were analyzed by nanoliquid chromatography coupled to high-resolution mass spectrometry on a QTOF 5600 (SCIEX) apparatus. The spectrometry data were analyzed with Mascot against the UniProtKB base and then several quality-control filters were applied for the identification of peptides (false discovery rate, FDR q < 0.02) and their quantification (FDR q < 0.05). In the group treated with teriparatide, 28 proteins were identified with significant differences before and after treatment. A pathway analysis by using the Reactome database revealed significant enrichment in the Insulin Like Growth Factor 1 (IGF-I) (FDR q 4 × 10-²) and innate immune system (FDR q 2 × 10-³) pathways. Among patients treated with denosumab, we observed significant differences in the levels of 10 proteins, which were also enriched in the pathways related to the innate immune system (FDR q 3 × 10-²). These results suggest that the innate immune system may be involved in the response to antiosteoporosis drugs.Funding: Supported by grants from FEIOMM (Grant No.17/0025) and ProteoRed-ISCIII. Acknowledgments: Alvaro del Real received support by the postdoctoral grant Augusto Gonzalez de Linares of the University of Cantabria

Memory and strategic processing in first-degree relatives of obsessive compulsive patients

Background: the same executive dysfunctions and alterations in neuroimaging tests (both functional and structural) have been found in obsessive-compulsive patients and their first-degree relatives. These neurobiological findings are considered to be intermediate markers of the disease. The aim of our study was to assess verbal and non-verbal memory in unaffected first-degree relatives, in order to determine whether these neuropsychological functions constitute a new cognitive marker for obsessive-compulsive disorder (OCD). Method: recall and use of organizational strategies in verbal and non-verbal memory tasks were measured in 25 obsessive-compulsive patients, 25 unaffected first-degree relatives and 25 healthy volunteers. Results: first-degree relatives and healthy volunteers did not show differences on most measures of verbal memory. However, during the recall and processing of non-verbal information, deficits were found in first-degree relatives and patients compared with healthy volunteers. Conclusions: the presence of the same deficits in the execution of non-verbal memory tasks in OCD patients and unaffected first-degree relatives suggests the influence of certain genetic and/or familial factors on this cognitive function in OCD and supports the hypothesis that deficits in non-verbal memory tasks could be considered as cognitive markers of the disorder

Heteroleptic Iron(II) Spin-Crossover Complexes Based on a 2,6-Bis(pyrazol-1-yl)pyridine-type Ligand Functionalized with a Carboxylic Acid

Two new heteroleptic complexes [Fe- (1bppCOOH)(3bpp-bph)](ClO4)2·solv (1·solv, solv = various solvents; 1bppCOOH = 2,6-bis(1H-pyrazol-1-yl)- isonicotinic acid; 3bpp-bph = 2,6-bis(5-([1,1′-biphenyl]-4- yl)-1H-pyrazol-3-yl)pyridine) and [Fe(1bppCOOH)- (1bppCOOEt)](ClO4)2 ·0.5Me2CO (2·0.5Me2CO, 1bppCOOEt = ethyl 2,6-bis(1H-pyrazol-1-yl)isonicotinate) were designed and prepared. The heteroleptic compound 1· solv was obtained by the combination of stoichiometric amounts of Fe(ClO4)2, 1bppCOOH, and 3bpp-bph, and it was designed to fine-tune the spin crossover (SCO) properties with respect to the previously reported homoleptic compound [Fe(1bppCOOH)2](ClO4)2. Indeed, the introduction of a new substituted 3bpp ligand induces a weaker ligand field in addition to promoting the formation of π···π and C−H···π intermolecular interactions through the biphenyl groups. For the desolvated counterpart 1, this results in a shift of the SCO curve toward room temperature and the observation of a 13 K hysteresis width. Besides, compound 2·0.5Me2CO, which represents the first example of a heteroleptic complex containing two 1bpp tridentate ligands, stabilizes the LS state at room temperature confirming the same trend observed for the corresponding homoleptic compounds. Interestingly, both 1 and 2·0.5Me2CO heteroleptic complexes exhibit photoswitchable properties when irradiating with a 523 nm laser at 10 K. Preliminary characterization of the deposited complexes on native SiO2 by X-ray absorption measurements suggests oxidation and decomposition of the complexes

Hyperbaric Oxygen Therapy Does Not Have a Negative Impact on Bone Signaling Pathways in Humans

Introduction: Oxygen is emerging as an important factor in the local regulation of bone remodeling. Some preclinical data suggest that hyperoxia may have deleterious effects on bone cells. However, its clinical relevance is unclear. Hence, we studied the effect of hyperbaric oxygen therapy (HBOT) on serum biomarkers reflecting the status of the Wnt and receptor activator of NF-?B ligand (RANKL) pathways, two core pathways for bone homeostasis. Materials and methods: This was a prospective study of 20 patients undergoing HBOT (mean age 58 yrs., range 35?82 yrs.) because of complications of radiotherapy or chronic anal fissure. Patients were subjected to HBOT (100% oxygen; 2.4 atmospheres absolute for 90 min). The average number of HBOT sessions was 20 ± 5 (range 8?31). Serum hypoxia-inducible factor 1-? (HIF1-?), osteoprotegerin (OPG), RANKL, and the Wnt inhibitors sclerostin and dickkopf-1 (DKK1) were measured at baseline and after HBOT by using specific immunoassays. Results: HIF-1? in eight patients with measurable serum levels increased from 0.084 (0.098) ng/mL at baseline to 0.146 (0.130) ng/mL after HBOT (p = 0.028). However, HBOT did not induce any significant changes in the serum levels of OPG, RANKL, sclerostin or DKK1. This was independent of the patients? diagnosis, either neoplasia or benign. Conclusion: Despite the potential concerns about hyperoxia, we found no evidence that HBOT has any detrimental effect on bone homeostasis