855 resultados para repeated measures
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In this thesis, we evaluate consumer purchase behaviour from the perspective of heuristic decision making. Heuristic decision processes are quick and easy mental shortcuts, adopted by individuals to reduce the amount of time spent in decision making. In particular, we examine those heuristics which are caused by framing – prospect theory and mental accounting, and examine these within price related decision scenarios. The impact of price framing on consumer behaviour has been studied under the broad umbrella of reference price, which suggests that decision makers use reference points as standards of comparison when making a purchase decision. We investigate four reference points - a retailer's past prices, a competitor's current prices, a competitor's past prices, and consumers' expectation of immediate future price changes, to further our understanding of the impact of price framing on mental accounting, and in turn, contribute to the growing body of reference price literature in Marketing research. We carry out experiments in which levels of price frame and monetary outcomes are manipulated in repeated measures analysis of variance (ANOVA). Our results show that where these reference points are clearly specified in decision problems, price framing significantly affects consumers' perceptions of monetary gains derived through discounts, and leads to reversals in consumer preferences. We also found that monetary losses were not sensitive to price frame manipulations.
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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.
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En la actualidad se han evaluado numerosas intervenciones preventivas de drogodependencias en el medio escolar. Sin embargo, en España son pocos los estudios que analizan la influencia precisa de cada uno de los componentes específicos a los programas con el fin de determinar cuáles se consideran cruciales para el cambio de conducta de consumo. El objetivo del presente estudio fue evaluar los efectos de una nueva versión del programa de prevención del consumo de drogas Saluda en la que se prescinde del componente fomento del ocio saludable y las tareas para casa. Esta versión reducida fue dirigida a una muestra de 106 escolares (44.6 % chicos) entre 14 y 17 años (M = 15.20; DT = 0.92) de un centro de Educación Secundaria. Se trata de un estudio exploratorio de tipo cuasi experimental y un diseño pre-post de un único grupo. Se realizó diferencia de proporciones mediante la prueba Z y diferencia de medias mediante la prueba T para muestras relacionadas. Los resultados muestran una reducción en el porcentaje de episodios de embriaguez, así como un efecto de mejora significativa sobre las variables protectoras del consumo. Se discuten estos hallazgos y se realizan propuestas para la mejora de futuras intervenciones.
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The purpose of the present study was to investigate percentage body fat (%BF) differences in three Spanish dance disciplines and to compare skinfold and bioelectrical impedance predictions of body fat percentage in the same sample. Seventy-six female dancers, divided into three groups, Classical (n=23), Spanish (n=29) and Flamenco (n=24), were measured using skinfold measurements at four sites: triceps, subscapular, biceps and iliac crest, and whole body multi-frequency bioelectrical impedance (BIA). The skin-fold measures were used to predict body fat percentage via Durnin and Womersley's and Segal, Sun and Yannakoulia equations by BIA. Differences in percent fat mass between groups (Classical, Spanish and Flamenco) were tested by using repeated measures analysis (ANOVA). Also, Pearson's product-moment correlations were performed on the body fat percentage values obtained using both methods. In addition, Bland-Altman plots were used to assess agreement, between anthropometric and BIA methods. Repeated measures analysis of variance did not found differences in %BF between modalities (p<0.05). Fat percentage correlations ranged from r= 0.57 to r=0.97 (all, p<0.001). Bland-Altman analysis revealed differences between BIA Yannakoulia as a reference method with BIA Segal (-0.35 ± 2.32%, 95%CI: -0.89to 0.18, p=0.38), with BIA Sun (-0.73 ± 2.3%, 95%CI: -1.27 to -0.20, p=0.014) and Durnin-Womersley (-2.65 ± 2,48%, 95%CI: -3.22 to -2.07, p<0.0001). It was concluded that body fat percentage estimates by BIA compared with skinfold method were systematically different in young adult female ballet dancers, having a tendency to produce underestimations as %BF increased with Segal and Durnin-Womersley equations compared to Yannakoulia, concluding that these methods are not interchangeable.
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This Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permission.
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Aim: To evaluate, in vitro, the effect of brushing with a Ricinus communis -based experimental toothpaste on color stability and surface roughness of artificial teeth. Methods: Ninety artificial teeth (maxillary central incisors) in different shades, light and dark (NatusDent Triple Pressing, Dentbras) were used. Initial color (Spectrophotometer Easyshade, VITA) and surface roughness (Rugosimeter Surfcorder SE 1700, Kosakalab) readouts were performed. After baseline measurements, samples were assigned to 10 groups (n=9) according to the artificial tooth shade and type of toothpaste used during the mechanical brushing test (Pepsodent, MAVTEC): Sorriso Dentes Brancos – SDB, Colgate Luminous White - CLW (Colgate-Palmolive), Close up White Now - CWN (Unilever), Trihydral - THL (Perland Pharmacos) and Ricinus communis - RCE (Experimental). After 29,200 cycles of brushing, corresponding to 2 years of brushing by a healthy individual, new color and roughness readouts of the specimens were performed. Data (before and after the tests) were statistically analyzed (2-way repeated measures ANOVA, Tukey, p<0.05). Results: RCE toothpaste produced the greatest color stability for dark tooth shade and the second best color stability for light tooth shade. For surface roughness alteration, there was no difference (p>0.05) for any tested toothpaste regardless of tooth shade. Conclusions: The experimental Ricinus communis toothpaste did not cause color and surface roughness alteration in the artificial teeth, and it may be considered a suitable option for denture cleaning.
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The color stability of resin cements is essential for aesthetic restorations. Aim: To evaluate the influence of shade and aging time on the color stability of two light-cured and two dual-cured resin cements. Methods: The CIE-Lab color parameters (n=6) were measured immediately after sample preparation and at 7, 30 and 90 days of aging in distilled water. The color difference (ΔE) was calculated and then analyzed by three-way ANOVA for repeated measures and Tukey’s HSD test (α=0.05). Results: ΔE was higher for transparent resin colors, followed by dark and light colors. The mean values of ΔE were lower for both light-cured resin cements compared to the dual-cured cements. As the aging time increased, ΔE values increased. Conclusions: The light-cured resin cements showed greater color stability. The lighter shades of luting were more likely to display a greater color change.
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Aim: To investigate the relation between uncooperative behavior and salivary cortisol level in children who underwent preventive dental care. Methods: The sample was composed by 10 children of both sexes aged 40 to 52 months, presenting uncooperative behavior during dental preventive treatments. The saliva collection was performed using a cotton wheel and an Eppendorf tube (Sarstedt Salivete®) in 3 different moments: a) at home, on a day without dental treatment and at the same time on the day of the sessions treatment; b) 30 min after the end of the session, when there was manifestation of uncooperative behavior; c) 30 min after the end of the session, when there was a cooperative behavior of the child. A sample of saliva was centrifuged for 5 minutes at 2400 rpm, 1 of mL of saliva was pipetted in an Eppendorf tube and stored in a freezer at -20 ° C. For the determination of the levels of salivary cortisol was used an Active® kit for cortisol enzyme immunoassay (EIA) DSL-10-67100, composed of specific rabbit antibody anti-cortisol. Data were analyzed statistically for the uncooperative behavior issued in the beginning and at the end of sessions, using the paired t test (p<0.05) and for cortisol levels in saliva samples at home, after the beginning and at the end of sessions, using repeated-measures ANOVA and Tukey’s test (p<0.05). Results: During expression of uncooperative behavior in preventive dental care sessions the salivary cortisol level was significantly higher (0.65 ± 0.25 μg/dL) compared with expression of collaborative behavior (0.24 ± 0.10 μg/dL). Conclusions: It is possible to conclude that, even under preventive intervention, the stress must be controlled in order to reduce dental anxiety and fear.
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Tese (doutorado)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Programa de Pós-Graduação em Administração, 2016.
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Determinar la influencia de las espículas peneanas en los cobayos machos sobre el comportamiento sexual, fertilidad y valores espermáticos, fue el objetivo principal de este proyecto de investigación, para ello se incluyeron 10 cobayos machos de cinco meses de edad, peso promedio 988,3±11,40 g y 40 hembras de cuatro meses de edad, peso promedio 815,3±11,80 g, bajo las mismas condiciones de alimentación y mantenimiento. Cinco machos seleccionados al azar fueron extirpados quirúrgicamente las espículas peneanas. Un cobayo entero y un intervenido fueron mantenidos, como reemplazo en el caso de muerte de una unidad experimental y se los excluyó del procedimiento inicial. Se realizaron tres ensayos: en el primero se dividieron en dos tratamientos T1= 4 cobayos machos con espículas peneanas + 20 hembras en jaulas separadas, T2= 4 cobayos machos extirpados las espículas peneanas + 20 hembras en jaulas separadas. Se analizó durante ocho días consecutivos el comportamiento sexual por observación directa de los cobayos en cada jaula. Para el segundo ensayo los mismos tratamientos T1 y T2, permanecieron por treinta días en empadre, para evaluación de la fertilidad. Finalmente en el último ensayo se analizaron parámetros espermáticos, por medio de la extirpación quirúrgica de los testículos y disección del epidídimo de los cobayos en estudio, para este ensayo se incluyeron los cobayos de reemplazo. El diseño experimental que se utilizó en la investigación fue un diseño completamente al azar, las pruebas de significación fueron, T de Student, prueba de Shapiro Wilk, para el análisis de homogeneidad de varianza se utilizó la técnica de Levene y se realizó el análisis de medias repetidas, todo esto con el programa SPSS para Windows versión 22®. Los parámetros de comportamiento sexual, olfateos, mordiscos y montas fueron similares (P>0,05), el número promedio de acicalamientos fue mayor en el grupo de machos enteros en relación al grupo sin espículas (P<0,05). El grupo de hembras que fueron copuladas por cobayos enteros quedaron preñadas un 65% más en comparación con las hembras que fueron cubiertas por los machos extirpados las espículas (P<0,01). No se encontraron diferencias significativas en los análisis de parámetros seminales de los machos en estudio. Por lo tanto se concluye que la remoción de las espículas peneanas influye en la fertilidad, pero no en el comportamiento sexual y los valores espermáticos
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Objective: determine the effect on the disability index of adult patients with benign paroxysmal positional vertigo (BPPV) using vestibular rehabilitation therapy (VRT) and human movement. Subjects: six subjects with an average age of 49.5 ± 14.22 years who have been diagnosed with benign paroxysmal positional vertigo by an otolaryngologist. Instruments: the Dizziness Handicap Inventory and a questionnaire to determine impact on the quality of life of patients with this pathology (Ceballos and Vargas, 2004). Procedure: subjects underwent vestibular therapy for four weeks together with habituation and balance exercises in a semi-supervised manner. Two measurements were performed, one before and one after the vestibular therapy and researchers determined if there was any improvement in the physical, functional, and emotional dimensions. Statistical analysis: descriptive statistics and Student’s t-test of repeated measures were applied to analyze results obtained. Results: significant statistical differences were found in the physical dimension between the pre-test (19.33 ± 4.67 points) and post-test (13 ± 7.24 points) (t = 2.65; p < 0.05). In contrast, no significant statistical differences were found in the functional (t = 2.44; p>0.05), emotional (t = 2.37; p>0.05) or general dimensions (t = 2.55; p>0.05). Conclusion: vestibular therapy with a semi-supervised human movement program improved the index of disability due to vertigo (physical dimension) in BPPV subjects.
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The major aim of this study was to test the hypothesis that the introduction of the Nile tilapia (Oreochromis niloticus) and the enrichment with nutrients (N and P) interact synergistically to change the structure of plankton communities, increase phytoplankton biomass and decrease water transparency of a semi-arid tropical reservoir. One field experiment was performed during five weeks in twenty enclosures (8m3) to where four treatments were randomly allocated: with tilapia addition (T), with nutrients addition (NP), with tilapia and nutrients addition (T+NP) and a control treatment with no tilapia or nutrients addition (C). A two-way repeated measures ANOVA was done to test for time (t), tilapia (T) and nutrient (NP) effects and their interaction on water transparency, total phosphorus, total nitrogen, phytoplankton and zooplankton. The results show that there was no effect of nutrient addition on these variables but significant fish effects on the biomass of total zooplankton, nauplii, rotifers, cladocerans and calanoid copepods, on the biovolume of Bacillariophyta, Zygnemaphyceae and large algae (GALD ≥ 50 μm) and on Secchi depth. In addition, we found significant interaction effects between tilapia and nutrients on Secchi depth and rotifers. Overall, tilapia decreased the biomass of most zooplankton taxa and large algae (diatoms) and decreased the water transparency while nutrient enrichment increased the biomass of zooplankton (rotifers) but only in the absence of tilapia. In conclusion, the influence of fish on the reservoir plankton community and water transparency was greater than that of nutrient loading. This finding suggests that biomanipulation should be a greater priority in the restoration of eutrophic reservoirs in tropical semi-arid regions
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Lake sturgeon (Acipenser fulvescens) were historically abundant in the Huron-Erie Corridor (HEC), a 160 km river/channel network composed of the St. Clair River, Lake St. Clair, and the Detroit River that connects Lake Huron to Lake Erie. In the HEC, most natural lake sturgeon spawning substrates have been eliminated or degraded as a result of channelization and dredging. To address significant habitat loss in HEC, multi-agency restoration efforts are underway to restore spawning substrate by constructing artificial spawning reefs. The main objective of this study was to conduct post-construction monitoring of lake sturgeon egg deposition and larval emergence near two of these artificial reef projects; Fighting Island Reef in the Detroit River, and Middle Channel Spawning Reef in the lower St. Clair River. We also investigated seasonal and nightly timing of larval emergence, growth, and vertical distribution in the water column at these sites, and an additional site in the St. Clair River where lake sturgeon are known to spawn on a bed of ~100 year old coal clinkers. From 2010-12, we collected viable eggs and larvae at all three sites indicating that these artificial reefs are creating conditions suitable for egg deposition, fertilization, incubation, and larval emergence. The construction methods and materials, and physical site conditions present in HEC artificial reef projects can be used to inform future spawning habitat restoration or enhancement efforts. The results from this study have also identified the likelihood of additional uncharacterized natural spawning sites in the St. Clair River. In addition to the field study, we conducted a laboratory experiment involving actual substrate materials that have been used in artificial reef construction in this system. Although coal clinkers are chemically inert, some trace elements can be reincorporated with the clinker material during the combustion process. Since lake sturgeon eggs and larvae are developing in close proximity to this material, it is important to measure the concentration of potentially toxic trace elements. This study focused on arsenic, which occurs naturally in coal and can be toxic to fishes. Total arsenic concentration was measured in samples taken from four substrate treatments submerged in distilled water; limestone cobble, rinsed limestone cobble, coal clinker, and rinsed coal clinker. Samples were taken at three time intervals: 24 hours, 11 days, and 21 days. ICP-MS analysis showed that concentrations of total arsenic were below the EPA drinking water standard (10 ppb) for all samples. However, at the 24 hour sampling interval, a two way repeated measures ANOVA with a Holm-Sidak post hoc analysis (α= 0.05) showed that the mean arsenic concentration was significantly higher in the coal clinker substrate treatment then in the rinsed coal clinker treatment (p=0.006), the limestone cobble treatment (p
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The population of English Language Learners (ELLs) globally has been increasing substantially every year. In the United States alone, adult ELLs are the fastest growing portion of learners in adult education programs (Yang, 2005). There is a significant need to improve the teaching of English to ELLs in the United States and other English-speaking dominant countries. However, for many ELLs, speaking, especially to Native English Speakers (NESs), causes considerable language anxiety, which in turn plays a vital role in hindering their language development and academic progress (Pichette, 2009; Woodrow, 2006). Task-based Language Teaching (TBLT), such as simulation activities, has long been viewed as an effective approach for second-language development. The current advances in technology and rapid emergence of Multi-User Virtual Environments (MUVEs) have provided an opportunity for educators to consider conducting simulations online for ELLs to practice speaking English to NESs. Yet to date, empirical research on the effects of MUVEs on ELLs’ language development and speaking is limited (Garcia-Ruiz, Edwards, & Aquino-Santos, 2007). This study used a true experimental treatment control group repeated measures design to compare the perceived speaking anxiety levels (as measured by an anxiety scale administered per simulation activity) of 11 ELLs (5 in the control group, 6 in the experimental group) when speaking to Native English Speakers (NESs) during 10 simulation activities. Simulations in the control group were done face-to-face, while those in the experimental group were done in the MUVE of Second Life. The results of the repeated measures ANOVA revealed after the Huynh-Feldt epsilon correction, demonstrated for both groups a significant decrease in anxiety levels over time from the first simulation to the tenth and final simulation. When comparing the two groups, the results revealed a statistically significant difference, with the experimental group demonstrating a greater anxiety reduction. These results suggests that language instructors should consider including face-to-face and MUVE simulations with ELLs paired with NESs as part of their language instruction. Future investigations should investigate the use of other multi-user virtual environments and/or measure other dimensions of the ELL/NES interactions.
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Despite the well-known benefits of physical activity, in 2012, only 37.5% of older adults aged 60 years or older met recommended aerobic physical activity levels and 16.1% met muscle-strengthening guidelines. Effective exercise programs can help combat the problem of inactivity but 50% of those who start participating in an exercise program drop out within first few weeks, preventing them from gaining any health benefits. Since fall 2008, the Healthy Aging Regional Collaborative of South Florida has offered EnhanceFitness (EF), an evidence-based physical activity program to older adults. This dissertation compared EF effectiveness at 4-, 8-, and 12-months and examined the factors that were associated with program completion. A paired sample t-test identified changes at 4-months and repeated measures design was used to identify changes from baseline to 4-, 8-, and 12- months. Logistic regression was used to identify correlates associated with completion.^ Between October 1, 2008 and December 31, 2012, 4,531 older adults (>=60 years) attended one or more EF sessions. Participants showed significant improvement in the number of chair stands performed in 30-seconds with mean change of 1.7, 1.6, and 2.0 respectively at 4-,8-,and 12- months (p<0.001). Results suggest Black, non-Haitian men were less likely to complete the program when compared to white, non-Hispanic men (OR=0.41, p=0.02). Men who self-reported having at least one risk factor were more likely to complete the program (OR=1.81, p= 0.03). In addition, women who lived in Miami-Dade County (OR=2.13, p<0.001) and were 80 years or older (OR=1.46, p<0.05) were more likely to complete the program. When compared with non-Hispanic whites, Black women were less likely to complete the program (OR=0.613, p<0.01). Women who did not report depression were 1.6 times more likely to complete the program (OR=1.62, p<0.05). Absence of risk factors for chronic conditions increased completion rates among women (OR=1.63, p<0.01).^ Effectiveness results revealed that all participants significantly improved on all outcome measures. However, improvement is more than double for those who completed recommended sessions (p<0.01). Study findings reaffirm the successful translation of EF in community-based settings. Our findings suggest that participants should attend the minimum recommended sessions to attain greater health benefits.^