3,401 research outputs found

    Stability prediction of early orthopedic treatment in Class III malocclusion: morphologic discriminant analysis

    Get PDF
    Background To evaluate morphologic differences between class III malocclusion success and failure treatment subjects in order to identify which variables are more predictive for long-term stability in early orthopedic treatment. In this retrospective study, 31 patients were enrolled from the Department of Orthodontics (Rome Tor Vergata). Inclusion criteria were as follows: white ancestry, class III malocclusion, mixed dentition, cervical stage (CS) 1-2, no pseudo-class III. Pre-treatment radiographic and cast records were collected. Each patient underwent rapid maxillary expansion/facial mask/bite block (RME/FM/BB) orthopedic treatment until correction. At T1 (permanent dentition, CS4), records were recollected. According to treatment stability, relapse group (RG, 19) and success group (SG, 12) were identified. Sagittal and vertical cephalometric and digital cast measurements were performed. Student's t tests were used for statistically significant differences inter and intra groups. For discriminant analysis, relapse or success status was added to each patient's T0 data. Results At T0, RG showed larger upper anterior transversal width (p = 0.0266), while at T1 the upper anterior length was shorter than SG (p = 0.0028). Between T1 and T0, both groups showed larger upper anterior and posterior transversal widths. SG had greater upper anterior (p = 0.0066) and posterior (p = 0.449) sagittal length. RG presented larger lower anterior (p = 0.0012) and posterior (p = 0.0002) transversal widths, while there were no differences in SG lower arch. Discriminant analysis provided two predictive variables with an accuracy of 80.6%: upper anterior length and upper posterior length. Conclusion A shorter and wider maxilla could be a predisposing factor for relapse and failure of the early orthopedic treatment of class III malocclusion patients. The absence of mandibular changes could be predictable for treatment success

    Pollen and nectar sources used by honeybee colonies pollinating sunflower (Helianthus annuus) in the Colorado River Valley, Argentina

    Get PDF
    Pollen traps and beeswax foundations were set in order to study pollen and nectar sources used by honeybee colonies pollinating sunflower (Helianthus annuus L.) for the production of hybrid seed in the lower valley of the Colorado river in southern Argentina. Thirty-seven plant species in bloom were registered in the area surrounding the sunflower field. Most of them were scarcely represented. The honeybee maximum density recorded on the sunflower male-fertile line was 10.00 bees per 100 heads, while on the male-sterile line was 25.33 bees per 100 heads. Seven plant taxa were identified in the pollen loads and 26 in the honey samples. About 84% of the collected pollen came from three taxa: Centaurea solstitialis L., Eucalyptus camaldulensis Dehnh. and Cirsium vulgare (Savi) Airy -Shaw, and only 11% came from H. annuus. The taxa most gathered had high protein values, above 20%. The dominant and secondary pollen types in honey samples were Tamarix gallica L., E. camaldulensis, Brassicaceae and C. solstitialis. The results indicate that honeybees (Apis mellifera L.) foraged pollen and nectar mainly from the flora surrounding the sunflower field.Fuentes de polen y néctar utilizadas por colonias de Apis mellifera que polinizan girasol (Helianthus annuus) en el valle inferior del río Colorado, Argentina. Se colocaron trampas caza-polen y cuadros con cera estampada para estudiar las fuentes de polen y néctar utilizadas por colmenas que polinizan girasol para la producción de semilla híbrida en el valle inferior del río Colorado, Argentina. Treinta y siete especies en floración fueron registradas en cercanías al cultivo de girasol. La mayoría de ellas estuvieron escasamente representadas. La máxima densidad de abejas en la línea androfértil de girasol fue de 10,00 abejas por cada 100 inflorescencias, mientras que en la línea androestéril fue de 25,33 abejas por cada 100 inflorescencias. En las cargas polínicas se identificaron siete taxa, y 26 en las muestras de miel. El 84% en peso del polen recolectado correspondió a tres taxa: Centaurea solstitialis L., Eucalyptus camaldulensis Dehnh. y Cirsium vulgare (Savi) Airy -Shaw y sólo el 11% provino de H. annuus. Los taxa más cosecha-dos tuvieron valores de proteína altos, superiores a 20%. Los tipos polínicos dominantes y secun-darios en las muestras de miel fueron Tamarix gallica L. y E. camaldulensis, Brassicaceae y C. solstitialis. Los resultados indican que las abejas (Apis mellifera L.) recolectaron polen y néctar principalmente de la flora circundante al cultivo de girasol

    Stability prediction of early orthopedic treatment in Class III malocclusion: morphologic discriminant analysis

    Get PDF
    Abstract Background To evaluate morphologic differences between class III malocclusion success and failure treatment subjects in order to identify which variables are more predictive for long-term stability in early orthopedic treatment. In this retrospective study, 31 patients were enrolled from the Department of Orthodontics (Rome Tor Vergata). Inclusion criteria were as follows: white ancestry, class III malocclusion, mixed dentition, cervical stage (CS) 1-2, no pseudo-class III. Pre-treatment radiographic and cast records were collected. Each patient underwent rapid maxillary expansion/facial mask/bite block (RME/FM/BB) orthopedic treatment until correction. At T1 (permanent dentition, CS4), records were recollected. According to treatment stability, relapse group (RG, 19) and success group (SG, 12) were identified. Sagittal and vertical cephalometric and digital cast measurements were performed. Student’s t tests were used for statistically significant differences inter and intra groups. For discriminant analysis, relapse or success status was added to each patient’s T0 data. Results At T0, RG showed larger upper anterior transversal width (p = 0.0266), while at T1 the upper anterior length was shorter than SG (p = 0.0028). Between T1 and T0, both groups showed larger upper anterior and posterior transversal widths. SG had greater upper anterior (p = 0.0066) and posterior (p = 0.449) sagittal length. RG presented larger lower anterior (p = 0.0012) and posterior (p = 0.0002) transversal widths, while there were no differences in SG lower arch. Discriminant analysis provided two predictive variables with an accuracy of 80.6%: upper anterior length and upper posterior length. Conclusion A shorter and wider maxilla could be a predisposing factor for relapse and failure of the early orthopedic treatment of class III malocclusion patients. The absence of mandibular changes could be predictable for treatment success

    Maxillary arch development with Invisalign system: Analysis of expansion dental movements on digital dental casts

    Get PDF
    Objectives: To evaluate tooth movements during maxillary arch expansion with clear aligner treatment.Materials and Methods: The study group included 28 subjects (16 females, 12 males, mean age 31.9 +/- 5.4 years) collected prospectively from January 2018 to May 2019. Inclusion criteria were European ancestry, posterior transverse discrepancy of 3-6 mm, permanent dentition stage, presence of second permanent molars, mild or moderate crowding, and good compliance with aligners. Treatment protocol included nonextraction strategies, application of Invisalign clear aligner system, and no auxiliaries other than Invisalign attachments. Linear and angular measurements were performed before treatment (T1), at the end of treatment (T2), and on final virtual models (T2 ClinCheck). A paired t-test was used to compare T2-T1 and T2-T2 ClinCheck changes. The level of significance was set at 5%.Results: Statistically significant differences were found for all measurements, except for ones at the upper second molars. The greatest increase in maxillary width was detected at the upper first and second premolars: 13.5 mm for the first premolar and 13.8 mm for the second premolar at T2. Comparison of T2-T1 angular outcomes showed statistically significant changes in the inclinations of all teeth except for the second permanent molars. T2-T2 ClinCheck showed significant differences for both linear and angular measurements for maxillary canines, resulting in poor predictability.Conclusions: Maxillary arch development revealed a progressive reduction of the expansion rate and buccal tipping in the anterior, lateral, and posterior regions, with the greatest net increase at the first and second premolars. Clinical attention should be paid to maxillary canine movements, and overcorrection should be planned for them during dentoalveolar expansion

    The OPERA magnetic spectrometer

    Full text link
    The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.Comment: 6 pages, 10 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

    Appraisals of instructional context, control beliefs and academic emotions. A case study with advanced university students

    Get PDF
    [EN] In this paper we set out to provide contributions that reveal more about students who attend to university classrooms, from knowing their perceptions of the instructional context, the possibilities of taking control of their learning processes and the emotions they experience accordingly. We worked with an accidental sample (N=39) composed by all the students which in 2010 attended a course on the final part of the curriculum of a career of education at the Universidad Nacional de Río Cuarto (Argentina). Data were collected through the Motivated Strategies for Learning Questionnaire, the Achievement Emotions Questionnaire and focal semistructured interviews. The results are organized into four sections: a) appraisals attributed by students to instructional context; b) aspects of their control belief of learning; c) academic emotions experienced within the context of learning considered; d) statistically significant correlations between variables motivational and emotional focalized in this study. The final considerations are grouped into three categories: a) relevance of considering appraisals and control beliefs as antecedents of academic emotions; b) addressing the importance of tasks that are appreciated as significant for professional education and c) need to investigate into personal aspects in real contexts of learning.[ES] En este trabajo nos propusimos brindar aportes que permitan conocer más acerca de los estudiantes que habitan las aulas universitarias, a partir de indagar sus percepciones sobre el contexto instructivo, las posibilidades de tomar control en sus procesos de aprendizaje y las emociones que experimentan en consecuencia. Se trabajó con una muestra accidental (N=39) compuesta por el total de alumnos que durante el año 2010 cursó una asignatura ubicada en el tramo final del plan de estudio de una Carrera de Educación de la Universidad Nacional de Río Cuarto (Argentina). Los datos fueron recabados a través del Motivated Strategies for Learning Questionnaire, el Achievement Emotions Questionnaire y entrevistas focales semiestructuradas. Los resultados se organizan en cuatro apartados: a) valoraciones atribuidas por los alumnos al contexto instructivo; b) aspectos relativos a sus creencias de control de los aprendizajes; c) emociones académicas experimentada en el marco del contexto de aprendizaje considerado; d) correlaciones estadísticamente significativas entre variables motivacionales y emocionales focalizadas en este estudio. Las consideraciones finales se agrupan en tres ejes: a) relevancia de considerar las valoraciones y las creencias de control como antecedentes próximos de las emociones; b) importancia de atender al diseño de tareas que sean valoradas como significativas para la formación profesional y c) necesidad de continuar investigando en relación a aspectos personales en contextos reales de aprendizaje.Vaja, AB.; Paoloni, PV. (2016). Valoración del contexto instructivo, creencias de control y emociones académicas. Un estudio con universitarios avanzados. REDU. Revista de Docencia Universitaria. 14(2):225-243. doi:10.4995/redu.2016.5950.SWORD22524314

    Big five, self-regulation, and coping strategies as predictors of achievement emotions in undergraduate students

    Get PDF
    The study focused on the analysis of linear relations between personality, self-regulation, coping strategies and achievement emotions. The main objective was to establish a model of linear, empirical, associative to infer needs and proposals for intervening in emotional health in the dierent profiles of university students. A total of 642 undergraduate students participated in this research. Evidence of associative relations between personality factors, self-regulation and coping strategies was found. The neuroticism factor had a significant negative associative relationship with Self-Regulation both globally and in its factors; especially important was its negative relation to decision making, and coping strategies focused in emotion. The results of Structural Equation Model showed an acceptable model of relationships, in each emotional context. Results and practical implications are discussed
    • …
    corecore