Analysis of residuals in contingency tables: another nail in the coffin of conditional approaches to significance testing.

Omnibus tests of significance in contingency tables use statistics of the chi-square type. When the null is rejected, residual analyses are conducted to identify cells in which observed frequencies differ significantly from expected frequencies. Residual analyses are thus conditioned on a significant omnibus test. Conditional approaches have been shown to substantially alter type I error rates in cases involving t tests conditional on the results of a test of equality of variances, or tests of regression coefficients conditional on the results of tests of heteroscedasticity. We show that residual analyses conditional on a significant omnibus test are also affected by this problem, yielding type I error rates that can be up to 6 times larger than nominal rates, depending on the size of the table and the form of the marginal distributions. We explored several unconditional approaches in search for a method that maintains the nominal type I error rate and found out that a bootstrap correction for multiple testing achieved this goal. The validity of this approach is documented for two-way contingency tables in the contexts of tests of independence, tests of homogeneity, and fitting psychometric functions. Computer code in MATLAB and R to conduct these analyses is provided as Supplementary Material.

Barriers to and facilitators of older adult’s adherence to health recommendations: Towards an EngAging two-way health communication

Non-adherence to health recommendations (e.g. medical prescriptions) presents potential costs for healthcare, which could be prevented or mitigated. This is often attributed to a person’s rational choice, to not adhere. However, this may also be determined by individual and contextual factors implied in the recommendations communication process. In accordance, this chapter focuses specifically on barriers to and facilitators of adherence to recommendations and engagement with the healthcare process, particularly concerning the communication between health professionals and patients. For this, the authors present examples of engagement increment through different degrees of participation, from a one-way/directive towards a two-way/engaging communication process. This focuses specifically on a vulnerable population group with increasing healthcare needs: older adults. Future possibilities for two-way engaging communications are discussed, aimed at promoting increased adherence to health recommendations and people’s self-regulation of their own health.

Odour flux from litter of broiler chickens fed diets differing in protein levels and additives

The effect of dietary crude protein (CP) and additives on odour flux from broiler litter was investigated using 180 day-old Ross 308 male chicks randomly allocated to five dietary treatments with three replications of 12 birds each. A 5×3 factorial arrangement of treatments was employed. Factors were: diet (low CP, high CP, high CP+antibiotic, high CP+probiotic, high CP+saponin) and age (15, 29, 35 days). Low CP (LCP) and high CP (HCP) diets differed in CP levels by 4.5-5%. The low CP diets were supplemented with L-valine, L-isoleucine, L-arginine, L-lysine, D,L-methionine and L-threonine. The antibiotic used was Zn Bacitracin, the probiotic was a blend of three Bacillus subtilis strains and the saponin came from a blend of Yucca and Quillaja. Odorants were measured from litter headspace using a flux hood and selective ion flow tube mass spectrometry (SIFT-MS). Results were log tranformed and analysed by two-way ANOVA with repeated measures using JMP statistical software v.8, and means were separated by Tukey's HSD test at P<0.05.The results showed that LCP group produced lower flux of dimethyl amine, trimethyl amine, H2S, NH3 and phenol in litter compared to HCP group (P<0.05). Similarly, HCP+probiotic group produced lower flux of H2S (P<0.05) and HCP+saponin group produced lower flux of trimethylamine and phenol in litter compared to HCP group (P<0.05). The dietary treatments tended (P=0.065) to have higher flux of methanethiol in HCP group compared to others. There was a diet x age interaction for litter flux of diacetyl, acetoin, 3-methyl-1-butanol, 3-methylbutanal, ethanethiol, propionic acid and hexane (P<0.05). Concentrations of diacetyl, acetoin, propionic acid and hexane in litter were higher from LCP group compared to all other treatments on d 35 (P<0.05) but not on days 15 and 29. Thus, the low CP diet, Bacillus subtilis based probiotic and Yucca/Quillaja based saponin were effective in reducing the emissions of some key odorants from broiler litter.

Investigating problem-based learning in Saudi Arabian mathematics education: a TIMSS-related study

The aim of this study is to investigate the effectiveness of problem-based learning (PBL) on students’ mathematical performance. This includes mathematics achievement and students’ attitudes towards mathematics for third and eighth grade students in Saudi Arabia. Mathematics achievement includes, knowing, applying, and reasoning domains, while students’ attitudes towards mathematics covers, ‘Like learning mathematics’, ‘value mathematics’, and ‘a confidence to learn mathematics’. This study goes deeper to examine the interaction of a PBL teaching strategy, with trained face-to-face and self-directed learning teachers, on students’ performance (mathematics achievement and attitudes towards mathematics). It also examines the interaction between different ability levels of students (high and low levels) with a PBL teaching strategy (with trained face-to-face or self-directed learning teachers) on students’ performance. It draws upon findings and techniques of the TIMSS international benchmarking studies. Mixed methods are used to analyse the quasi-experimental study data. One -way ANOVA, Mixed ANOVA, and paired t-tests models are used to analyse quantitative data, while a semi-structured interview with teachers, and author’s observations are used to enrich understanding of PBL and mathematical performance. The findings show that the PBL teaching strategy significantly improves students’ knowledge application, and is better than the traditional teaching methods among third grade students. This improvement, however, occurred only with the trained face-to-face teacher’s group. Furthermore, there is robust evidence that using a PBL teaching strategy could raise significantly students’ liking of learning mathematics, and confidence to learn mathematics, more than traditional teaching methods among third grade students. Howe ver, there was no evidence that PBL could improve students’ performance (mathematics achievement and attitudes towards mathematics), more than traditional teaching methods, among eighth grade students. In 8th grade, the findings for low achieving students show significant improvement compared to high achieving students, whether PBL is applied or not. However, for 3th grade students, no significant difference in mathematical achievement between high and low achieving students was found. The results were not expected for high achieving students and this is also discussed. The implications of these findings for mathematics education in Saudi Arabia are considered.

Effects of two teaching interventions on nursing students’ acquisition of competence in ECG interpretation

Purpose: Nurse ability to recognise patient arrhythmias could contribute to preventing in-hospital cardiac arrest. Research suggests that nurses and nursing students lack competence in electrocardiogram (ECG) interpretation. The aim of this study was to compare the effects of two training strategies on nursing students’ acquisition of competence in ECG interpretation. Materials and methods: A controlled randomised trial with 98 nursing students. Divided in groups of 12–16, participants were randomly allocated to one of the following 3-h teaching intervention groups: 1) traditional instructor-led (TILG), and 2) flipped classroom (FCG). Participants’ competence in ECG interpretation was measured in terms of knowledge (%), skills (%) and self-efficacy (%) using a specifically designed and previously validated toolkit at pre-test and post-test. Two-way MANOVA explored the interaction effect between ‘teaching group’ and ‘time of assessment’ and its impact on participants’ competence. Within-group differences at pre-test and post-test were explored by carrying out paired t-tests. Between-group differences at pre- and post-test were examined by performing independent t-test analysis. Results: There was a statistically significant interaction effect between ‘teaching group’ and ‘time of assessment’ on participants’ competence in ECG interpretation (F(3,190) = 86.541, p = 0.001; Wilks’ Λ = 0.423). At pre-test, differences in knowledge (TILG = 35.12 ± 12.07; FCG = 35.66 ± 10.66), skills (TILG = 14.05 ± 10.37; FCG = 14.82 ± 14.14), self-efficacy (TILG = 46.22 ± 23.78; FCG = 40.01 ± 21.77) and all other variables were non-significant (p > 0.05). At post-test, knowledge (TILG = 55.12 ± 14.16; FCG = 94.2 ± 7.31), skills (TILG = 36.90 ± 16.45; FCG = 86.43 ± 14.32) and self-efficacy (TILG = 70.78 ± 14.55; FCG = 79.98 ± 10.35) had significantly improved, regardless of the training received (p < 0.05). Nonetheless, participants in the FCG scored significantly higher than participants in the TILG in knowledge, skills and self-efficacy (p < 0.05). Conclusion: Flipping the classroom for teaching ECG interpretation to nursing students may be more effective than using a traditional instructor-led approach in terms of immediate acquisition of competence in terms of knowledge, skills and self-efficacy. Further research on the effects of both teaching strategies on the retention of the competence will be undertaken.

Comparison of multiple intelligences in children from schools with different pedagogical models

The purpose of this research was to apply a test that measures different multiple intelligences in children from two different elementary schools to determine whether there are differences between the Academicist Pedagogical Model (traditional approach) established by the Costa Rican Ministry of Public Education and the Cognitive Pedagogical Model (MPC) (constructivist approach). A total of 29 boys and 20 girls with ages 8 to 12 from two different public schools in Heredia (Laboratorio School and San Isidro School) participated in this study. The instrument used was a Multiple Intelligences Test for school age children (Vega, 2006), which consists of 15 items subdivided in seven categories: linguistic, logical-mathematical, visual, kinaesthetic, musical, interpersonal, and intrapersonal. Descriptive and inferential statistics (Two-Way ANOVA) were used for the analysis of data.  Significant differences were found in linguistic intelligence (F:9.47; p < 0.01) between the MPC school (3.24±1.24 points) and the academicist school (2.31±1.10 points).  Differences were also found between sex (F:5.26; p< 0.05), for girls (3.25±1.02 points) and boys (2.52±1.30 points). In addition, the musical intelligence showed significant statistical differences between sexes (F: 7.97; p < 0.05).  In conclusion, the learning pedagogical models in Costa Rican public schools must be updated based on the new learning trends.

Pelvic-Floor Rehabilitation, Part 2 : Pelvic-Floor Reeducation With Interferential Currents and Exercise in the Treatment of Genuine Stress Incontinence in Postpartum Women : A Cohort Study

Background and Purpose. This descriptive cohort study investigated a physical therapy program of pelvic-floor neuromuscular electrostimulation (NMES) combined with exercises, with the aim of developing a simple, inexpensive, and conservative treatment for postpartum genuine stress incontinence (GSI). Subjects. Eight female subjects with urodynamically established GSI persisting more than 3 months after delivery participated in the study. The subjects ranged in age from 24 to 37 years (X̅=32, SD=4.2). Methods. This was a descriptive multiple-subject cohort study. Each subject received a total of nine treatment sessions during 3 consecutive weeks, consisting of two 15-minute sessions of NMES followed by a 15-minute pelvic-floor muscle exercise program. Patients also practiced daily pelvic-floor exercises during the 3-week treatment period. The treatment intervention was measured using three separate variables. Maximum muscle contractions (pretraining, during training, and posttraining) were measured indirectly as pressure, using perineometry. Urine loss pretraining and posttraining was measured by means of a Pad test. Self-reported frequency of incontinence was recorded daily throughout the period of the study, using a diary. Data were analyzed using a one-way repeated measures analysis of variance (ANOVA), a Wilcoxon signed-ranks test, and a Friedman two-way ANOVA by ranks. Results. The results indicated that maximum pressure generated by pelvic-floor contractions was greater and both the quantity of urine loss and the frequency of incontinence were lower following the implementation of the physical therapy program. Five subjects became continent, and three others improved. A follow-up survey 1 year later confirmed the consistency of these results. Conclusion and Discussion. The results suggest that the proposed physical therapy program may influence postpartum GSI. Further studies are needed to validate this simple, inexpensive, and conservative physical therapy protocol.

Pelvic-Floor Rehabilitation, Part 2 : Pelvic-Floor Reeducation With Interferential Currents and Exercise in the Treatment of Genuine Stress Incontinence in Postpartum Women : A Cohort Study

Background and Purpose. This descriptive cohort study investigated a physical therapy program of pelvic-floor neuromuscular electrostimulation (NMES) combined with exercises, with the aim of developing a simple, inexpensive, and conservative treatment for postpartum genuine stress incontinence (GSI). Subjects. Eight female subjects with urodynamically established GSI persisting more than 3 months after delivery participated in the study. The subjects ranged in age from 24 to 37 years (X̅=32, SD=4.2). Methods. This was a descriptive multiple-subject cohort study. Each subject received a total of nine treatment sessions during 3 consecutive weeks, consisting of two 15-minute sessions of NMES followed by a 15-minute pelvic-floor muscle exercise program. Patients also practiced daily pelvic-floor exercises during the 3-week treatment period. The treatment intervention was measured using three separate variables. Maximum muscle contractions (pretraining, during training, and posttraining) were measured indirectly as pressure, using perineometry. Urine loss pretraining and posttraining was measured by means of a Pad test. Self-reported frequency of incontinence was recorded daily throughout the period of the study, using a diary. Data were analyzed using a one-way repeated measures analysis of variance (ANOVA), a Wilcoxon signed-ranks test, and a Friedman two-way ANOVA by ranks. Results. The results indicated that maximum pressure generated by pelvic-floor contractions was greater and both the quantity of urine loss and the frequency of incontinence were lower following the implementation of the physical therapy program. Five subjects became continent, and three others improved. A follow-up survey 1 year later confirmed the consistency of these results. Conclusion and Discussion. The results suggest that the proposed physical therapy program may influence postpartum GSI. Further studies are needed to validate this simple, inexpensive, and conservative physical therapy protocol.

Dynamics of galaxies in the cluster environment: a resonant origin for the ISP?

The internal dynamics of elliptical galaxies in clusters depends on many factors, including the environment in which the galaxy is located. In addition to the strong encounters with the other galaxies, we can also consider the gravitational interaction with the ubiquitous Cluster Tidal Field (CTF). As recognized in many studies, one possible way in which CTF affects the dynamics of galaxies inside the cluster is related to the fact that they may start oscillating as “rigid bodies” around their equilibrium positions in the field, with the periods of these oscillations curiously similar to those of stellar orbits in the outer parts of galaxies. Resonances between the two motions are hence expected and this phenomenon could significantly contribute to the formation of the Intracluster Stellar Population (ISP), whose presence is abundantly confirmed by observations. In this thesis work, we propose to study the motion of an elliptical galaxy, modelled as a rigid body, in the CTF, especially when its center of mass traces a quasi-circular orbit in the cluster gravitational potential. This case extends and generalizes the previous models and findings, proceeding towards a much more realistic description of galaxy motion. In addition to this, the presence of a further oscillation, namely that of the entire galaxy along its orbit, will possibly increase the probability of having resonances and, consequently, the rate of ISP production nearly to observed values. Thus, after reviewing the dynamics of a rigid body in a generic force field, we will assess some physically relevant studies and report their main results, discussing their implications with respect to our problem. We will conclude our discussion focusing on the more realistic scenario of an elliptical galaxy whose center of mass moves on a quasi-circular orbit in a spherically symmetric potential. The derivation of the fundamental equations of motion will serve as the basis for future modelling and discussions.

The Analgesic Effect Of Dipyrone In Peripheral Tissue Involves Two Different Mechanisms: Neuronal K(atp) Channel Opening And Cb(1) Receptor Activation.

Dipyrone (metamizole) is an analgesic pro-drug used to control moderate pain. It is metabolized in two major bioactive metabolites: 4-methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA). The aim of this study was to investigate the participation of peripheral CB1 and CB2 cannabinoid receptors activation in the anti-hyperalgesic effect of dipyrone, 4-MAA or 4-AA. PGE2 (100ng/50µL/paw) was locally administered in the hindpaw of male Wistar rats, and the mechanical nociceptive threshold was quantified by electronic von Frey test, before and 3h after its injection. Dipyrone, 4-MAA or 4-AA was administered 30min before the von Frey test. The selective CB1 receptor antagonist AM251, CB2 receptor antagonist AM630, cGMP inhibitor ODQ or KATP channel blocker glibenclamide were administered 30min before dipyrone, 4-MAA or 4-AA. The antisense-ODN against CB1 receptor expression was intrathecally administered once a day during four consecutive days. PGE2-induced mechanical hyperalgesia was inhibited by dipyrone, 4-MAA, and 4-AA in a dose-response manner. AM251 or ODN anti-sense against neuronal CB1 receptor, but not AM630, reversed the anti-hyperalgesic effect mediated by 4-AA, but not by dipyrone or 4-MAA. On the other hand, the anti-hyperalgesic effect of dipyrone or 4-MAA was reversed by glibenclamide or ODQ. These results suggest that the activation of neuronal CB1, but not CB2 receptor, in peripheral tissue is involved in the anti-hyperalgesic effect of 4-aminoantipyrine. In addition, 4-methylaminoantipyrine mediates the anti-hyperalgesic effect by cGMP activation and KATP opening.

Influence Of Fluorescent Dye On Physical-mechanical Properties Of Luting Cements For Confocal Microscopy Analysis.

To evaluate the influence of a fluorescent dye (rhodamine B) on the physical and mechanical properties of three different luting cements: a conventional adhesive luting cement (RelyX ARC, 3M/ESPE), a self-adhesive luting cement (RelyX U-200, 3M/ESPE), and a self-etching and self-adhesive luting cement (SeT PP, SDI). The cements were mixed with 0.03 wt% rhodamine B, formed into bar-shaped specimens (n = 10), and light cured using an LED curing unit (Radii, SDI) with a radiant exposure of 32 J/cm(2) . The Knoop hardness (KHN), flexural strength (FS), and Young's modulus (YM) analyses were evaluated after storage for 24 h. Outcomes were subjected to two-way ANOVA and Tukey's test (P = 0.05) for multiple comparisons. No significant differences in FS or YM were observed among the tested groups (P ≥ 0.05); the addition of rhodamine B increased the hardness of the luting cements tested. The addition of a fluorescent agent at 0.03 wt% concentration does not negatively affect the physical-mechanical properties of the luting cement polymerization behavior.