Construction and validation of a questionnaire to assess student satisfaction with mathematics learning materials

Sixth Edition Technological Ecosystems for Enhancing MulticulturalityMathematics is an essential branch for the scientific development and its study is mandatory in most university degrees. However, currently the level of academic performance and motivation of students to learn this science is not the desired one. The students can use different learning tools inside and outside the math classroom, enhancing the quality of the learning materials that are designed essentially to facilitate the learning of mathematics. The present research project aims to determine the validity and reliability of a measurement instrument that allows theassessment of the satisfaction of the students with the availablelearning materials. To fulfill the objectives of this research, the method of survey was used. A study with a quantitative approach was developed, which led to the design and validation of a questionnaire by a group of 7 experts. The validation closed after applying a pilot study with 728 students. It concluded positively, obtaining nine factors that coincide with the revision of the literature: technological quality, quality of content, visual quality, didactic significance, adequacy of content, relationship between theory and practice, involvement, contribution to learning, relevance and interaction between educational actors. The results of this questionnaire provide to the international scientific community with relevant information for the design, selection, and use of study materials in the classrooms, which will contribute to raising the levels of student engagement, and their academic performance in mathematics, secondaril

Microelectrode study of pore size, ion size, and solvent effects on the charge/discharge behavior of microporous carbons for electrical double-layer capacitors

The capacitive behavior of TiC-derived carbon powders in two different electrolytes, NEt4BF4 in acetonitrile AN and NEt4BF4 in propylene carbonate PC, was studied using the cavity microelectrode CME technique. Comparisons of the cyclic voltammograms recorded at 10–1000 mV/s enabled correlation between adsorbed ion sizes and pore sizes, which is important for understanding the electrochemical capacitive behavior of carbon electrodes for electrical double-layer capacitor applications. The CME technique also allows a fast selection of carbon electrodes with matching pore sizes different sizes are needed for the negative and positive electrodes for the respective electrolyte system. Comparison of electrochemical capacitive behavior of the same salt, NEt4BF4, in different solvents, PC and AN, has shown that different pore sizes are required for different solvents, because only partial desolvation of ions occurs during the double-layer charging. Squeezing partially solvated ions into subnanometer pores, which are close to the desolvated ion size, may lead to distortion of the shape of cyclic voltammograms

Colapso traqueal

El presente trabajo ha sido realizado con una revisión de 14 perros afectados con distintos grados de colapso traqueal, diagnosticados con radiografías. También se hace un estudio diferencial de otros estados patológicos que podrían confundirse.This work has been make with a revision of 14 affected dogs wíth differents degrees of tracheal collapse, diagnosed with X-ray. Also on makes a different study about others pathologicals states that can be motive of confusion

Predicting divorce in parents: the relationship between coparenting and divorce proneness

The longitudinal association between couples’ coparental disagreement and coparental support and wives’ and husbands’ individual divorce proneness was examined in a sample of 416 families. Both dimensions of coparenting were completed when the couples’ children were in sixth grade (wave 1, W1). Divorce proneness, conceptualized as the consideration or taking of steps towards divorce (Moore & Buehler, 2011; Whitton, Stanly, Markman, & Johnson, 2013), was measured both when children were in sixth and ninth grade (wave 4, W4). The present study also examined how W1 spousal negative marital communication moderated the association between W1 coparental disagreement and support with changes in wives’ and husbands’ W4 divorce proneness. Controlling for initial levels of divorce proneness and couples’ education, the present study examined three hypotheses. The first hypothesis postulated that W1 coparental disagreement and W1 coparental support each uniquely predicted changes in both wives’ and husbands’ perceptions of divorce proneness three years later (at wave 4, W4). Hypothesis 1 also predicted that W1 coparental disagreement was associated with increases in both wives’ and husbands’ W4 divorce proneness, whereas W1 coparental support was associated with decreases in both wives’ and husbands’ W4 divorce proneness. The second hypothesis postulated that W1 husbands’ negative marital communication moderated the associations between both W1 coparental disagreement and W1 coparental support with changes in W4 wives’ divorce proneness. Hypothesis 2 also predicted that W1 husbands’ negative marital communication exacerbated the unique association between W1 coparental disagreement and increases in W4 wives’ divorce proneness, whereas W1 husbands’ negative marital communication mitigated the unique association between W1 coparental support and decreases in W4 wives’ divorce proneness. The third hypothesis postulated that W1 wives’ negative marital communication moderated the associations between both W1 coparental disagreement and W1 coparental support with changes in W4 husbands’ divorce proneness. Hypothesis 3 also predicted that W1 wives’ negative marital communication exacerbated the unique association between W1 coparental disagreement and increases in W4 husbands’ divorce proneness, whereas W1 wives’ negative marital communication mitigated the unique association between W1 coparental support and decreases in W4 husbands’ divorce proneness. The study found evidence of a main effect for W1 coparental disagreement on increases in husbands’ W4 divorce proneness. W1 wives’ negative marital communication was also found to significantly moderate the association between coparental disagreement and increases in W4 husbands’ divorce proneness

On uniqueness for time harmonic anisotropic Maxwell's equations with piecewise regular coefficients

We are interested in the uniqueness of solutions to Maxwell's equations when the magnetic permeability $\mu$ and the permittivity $\varepsilon$ are symmetric positive definite matrix-valued functions in $\mathbb{R}^{3}$. We show that a unique continuation result for globally $W^{1,\infty}$ coefficients in a smooth, bounded domain, allows one to prove that the solution is unique in the case of coefficients which are piecewise $W^{1,\infty}$ with respect to a suitable countable collection of sub-domains with $C^{0}$ boundaries. Such suitable collections include any bounded finite collection. The proof relies on a general argument, not specific to Maxwell's equations. This result is then extended to the case when within these sub-domains the permeability and permittivity are only $L^\infty$ in sets of small measure.Comment: 9 pages, 4 figure

Stable Determination of the Electromagnetic Coefficients by Boundary Measurements

The goal of this paper is to prove a stable determination of the coefficients for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary measurements

Serum levels and removal by haemodialysis and haemodiafiltration of tryptophan-derived uremic toxins in ESKD patients

Tryptophan is an essential dietary amino acid that originates uremic toxins that contribute to end-stage kidney disease (ESKD) patient outcomes. We evaluated serum levels and removal during haemodialysis and haemodiafiltration of tryptophan and tryptophan-derived uremic toxins, indoxyl sulfate (IS) and indole acetic acid (IAA), in ESKD patients in different dialysis treatment settings. This prospective multicentre study in four European dialysis centres enrolled 78 patients with ESKD. Blood and spent dialysate samples obtained during dialysis were analysed with high-performance liquid chromatography to assess uremic solutes, their reduction ratio (RR) and total removed solute (TRS). Mean free serum tryptophan and IS concentrations increased, and concentration of IAA decreased over pre-dialysis levels (67%, 49%, -0.8%, respectively) during the first hour of dialysis. While mean serum total urea, IS and IAA concentrations decreased during dialysis (-72%, -39%, -43%, respectively), serum tryptophan levels increased, resulting in negative RR (-8%) towards the end of the dialysis session (p < 0.001), despite remarkable Trp losses in dialysate. RR and TRS values based on serum (total, free) and dialysate solute concentrations were lower for conventional low-flux dialysis (p < 0.001). High-efficiency haemodiafiltration resulted in 80% higher Trp losses than conventional low-flux dialysis, despite similar neutral Trp RR values. In conclusion, serum Trp concentrations and RR behave differently from uremic solutes IS, IAA and urea and Trp RR did not reflect dialysis Trp losses. Conventional low-flux dialysis may not adequately clear Trp-related uremic toxins while high efficiency haemodiafiltration increased Trp losses

ProBiS: a web server for detection of structurally similar protein binding sites

A web server, ProBiS, freely available at http://probis.cmm.ki.si, is presented. This provides access to the program ProBiS (Protein Binding Sites), which detects protein binding sites based on local structural alignments. Detailed instructions and user guidelines for use of ProBiS are available at the server under ‘HELP’ and selected examples are provided under ‘EXAMPLES’

Aproximações entre a ditadura e a democracia

This essay has as objective to rethink the existent relationship between the dictatorship and the democracy through the perspective of some elements of the classic and contemporary political thought. It intends to meet interfaces between both concepts of dictatorship and democracy that can contribute to the governability of current political reality.Key words: democracy, dictatorship, political thought.Este artigo tem como objetivo repensar a relação existente entre a ditadura e a democracia, sob a perspectiva de alguns elementos do pensamento político clássico e contemporâneo. Pretende-se encontrar interfaces entre ambos os conceitos que possam contribuir para a governabilidade da realidade política atual.Palavras-chave: democracia, ditadura, pensamento político