The effects of students' profile, communication, and discourse in an Advanced Placement statistics classroom

This study sought to describe the communicative aspect that should be part of any secondary mathematics classroom and, more specifically, the statistics classroom. Focusing on the observation of students allowed for a detailed account of the learning of students, i. e., what they said and wrote, how they used the materials provided by the teacher, what supports promoted understanding, and what difficulties to learning arose during the lesson. The research questions guiding the study were: (i) In what way is attention to students’ statistical thinking evident in lesson planning? (ii) To what extent does discourse in the classroom enable students to communicate effectively in the AP Statistics course? (iii) To what extent does communication, such as expressing organized and precise ideas, and analyzing and evaluating the statistical ideas of others, change over time? (iv) To what extent do students’ profiles influence success in the advanced placement statistics course? Garfield’s (2002, section 3, Table 1) general model of statistical reasoning provided a framework on which to base a characterization of students’ statistical reasoning. As has been found in earlier studies about teaching statistics (Garfield & Ben- Zvi, in press, Sherin, 2002), this teacher encountered challenges in establishing patterns of discourse to encourage effective student communication in the classroom. It was also found that student profiles were contributing factors in students’ success in the statistics course

Plataforma digital de ordenación de prácticas para la ETUZ

Realización de un prototipo de herramienta informática por lo que se ha necesitado previamente analizar las percepciones de los alumnos de la Escuela Universitaria de Turismo de Zaragoza<br /

Suppression of osteoarthritis via molecular engineering of an aggrecan mimetic

Osteoarthritis (OA) progresses via a feed-forward cycle in which inflammation leads to the up-regulation of catabolic enzymes that cleave the extracellular matrix (ECM) components. Fragments of ECM molecules hyaluronic acid and collagen type II further stimulate inflammation. The degradation of aggrecan is a critical early event in OA due to aggrecan’s ability to protect other ECM components from degradation and support the compressive strength of cartilage. Characterized herein is an aggrecan mimic’s (mAGC) ability to replace the functions of native aggrecan and halt the progression of OA. We examine mAGC in both ex vivo cartilage tissue models and in vivo animal models. Aggrecan-depleted cartilage plugs had only ~30% of the compressive strength of intact plug. mAGC was able to diffuse into the cartilage tissue and restore the compressive strength to 90% of the intact healthy cartilage. Depletion of aggrecan also resulted in an increase in catabolic gene expression by chondrocytes that was further amplified with additional inflammatory stimuli. Treatment with mAGC resulted in chondrocyte gene expression of catabolic enzymes at the same lower levels as healthy intact cartilage, both with and without inflammatory stimulation over 21 days. Intact cartilage plugs exposed to osteoarthritic synovial fluid resulted in high degradation of ECM components as measured by release into the culture media over an 8-day period. A single pretreatment with mAGC decreased this degradation to levels similar to those in healthy cultured controls. Further, inflammation and catabolic enzymatic gene expression was lowered in treated plugs to near healthy levels, even in the presence of the inflammatory and enzyme-rich synovial fluid. The data indicates that by providing robust protection against degradation and restoring the mechanical environment, the pro-inflammatory signals that cause upregulation of the degrading enzymes are decreased. In an aggressive rat model, mAGC was able to keep catabolic enzyme levels closer to healthy levels, preserve the proteoglycan content of cartilage tissue, and decrease bone loss when compared with untreated controls. In a nontraumatic guinea pig model, mACG suppressed the progression of OA. This study provides the ground-work for development of an intra-articular therapy that reduces fragmentation of key extracellular matrix components and restores the mechanical environment of the cartilage tissue, resulting in decrease in inflammation and catabolic enzyme production. The therapy has the potential to promote a healthy environment for future tissue regeneration

The use of Biopolymers for Tissue Engineering

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage damage and loss in the joints that affects approximately 27 million adults in the US. Tissue that is damaged by OA is a major health concern since cartilage tissue has a limited ability to self-repair due to the lack of vasculature in cartilage and low cell content. Tissue engineering efforts aim towards the development of cartilage repair strategies that mimic articular cartilage and are able to halt the progression of the disease as well as restore cartilage to its normal function. This study harnesses the biological activity of collagen type II, present in articular cartilage, and the superior mechanical properties of collagen type I by characterizing gels made of collagen type I and II blends (1:0, 3:1, 1:1, 1:3, and 0:1). The collagen blend hydrogels were able to incorporate both types of collagen and retain chondroitin sulfate (CS) and hyaluronic acid (HA). Cryoscanning electron microscopy images showed that the 3:1 ratio of collagen type I to type II gels had a lower void space percentage (36.4%) than the 1:1 gels (46.5%) and the complex modulus was larger for the 3:1 gels (G*=5.0 Pa) compared to the 1:1 gels (G*=1.2 Pa). The 3:1 blend consistently formed gels with superior mechanical properties compared to the other blends and has the potential to be implemented as a scaffold for articular cartilage engineering. Following the work done to characterize the collagen scaffolds, we studied whether an aggrecan mimic, CS-GAHb, composed of CS and HA binding peptides, GAH, and not its separate components, is able to prevent glycosaminoglycan (GAG) and collagen release when incorporated into chondrocyte-embedded collagen gels. Bovine chondrocytes were cultured and embedded in collagen type I scaffolds with CS, GAH, CS and GAH, or CS-GAHb molecules. Gels composed of 3:1 collagen type I and II with CS or CS-GAHb were also studied. The results obtained showed CS-GAHb is able to decrease GAG and collagen release and increase GAG retention in the gels. CSGAHb also stimulated cytokine production during the initial days of scaffold culture. However, the addition of CS-GAHb into the chondrocyte embedded collagen scaffolds did not affect ECM protein expression in the gels. The incorporation of collagen type II into the collagen type I scaffolds did not significantly affect GAG and cytokine production and ECM protein synthesis, but did increase collagen release. The results suggest the complex interaction between CS-GAHb, the chondrocytes, and the gel matrix make these scaffolds promising constructs for articular cartilage repair. Finally, we used Dunkin Hartley guinea pigs, a commonly used animal model of osteoarthritis, to determine if high frequency ultrasound can ensure intra-articular injections of the aggrecan mimic are accurately positioned in the knee joint. A highresolution small animal ultrasound system with a 40 MHz transducer was used for image-guided injections. We assessed our ability to visualize important anatomical landmarks, the needle, and anatomical changes due to the injection. From the ultrasound images, we were able to visualize clearly the movement of anatomical landmarks in 75% of the injections. The majority of these showed separation of the fat pad (67.1%), suggesting the injections were correctly delivered in the joint space. The results demonstrate this image-guided technique can be used to visualize the location of an intra-articular injection in the joints of guinea pigs and we are able to effectively inject the aggrecan mimic into knee joints

Evaluating the Effect of Hearing Status on Gait and Balance in Individuals With and Without Access to Auditory Cues

Background: It has recently been demonstrated that the importance of the auditory system’s contribution to the perception of posture and mobility increases in cases where input from other systems, such as vestibular peripheral, somatosensory, and visual, is reduced or compromised There is a growing interest in how auditory cues serve as an additional input that aids in postural stability, gait and balance, and self-motion perception. Recent evidence from other investigators reveals that auditory information may be used to improve all of these, but the process is poorly understood and requires further research. However, it would appear that preliminary information from these studies makes a strong case for clinicians to consider the importance of audition when developing treatment plans for people with hearing loss that may also be experiencing ongoing vestibular involvement. This research project aims to determine the effect of hearing status on static stability while standing and dynamic movement by measuring postural sway, gait speed, and step length using multiple wireless gait sensors. Methods: Individuals were fitted with an array of Opal sensors and were asked to complete five randomly ordered tasks (aka “conditions”). Each condition began with a measure of postural sway as a baseline. Vision was denied in all but one condition. Postural sway was measured by having participants stand upright with their feet at shoulder width, lined up at the starting mark with hands on their hips for 30 seconds. Participants then would complete another postural sway measure that immediately preceded the dynamic gait task where participants would walk down the track and return to the start position. For each “sway into walk” condition visual cues and auditory input were manipulated. Results: Mean values for postural sway and gait/lower limb support were compared to normative data from other studies using the same gait sensor technology. Mean values for postural sway were compared across conditions and revealed a statistically significant difference for the hearing-impaired participants when performing the first vision denied condition as compared to the normal hearing participants. The data did not demonstrate a statistical significance across the sway trials. Our data did not show any statistically significant changes between hearing-impaired and normal hearing participants during any of the trial conditions when analyzing gait parameters. A statistically significant change for gait speed and stride length was observed between our two baseline conditions. Mean values from our data collection were consistent with previously established reference intervals

Broadening the Western Music Theory Canon

Western Classical Music Theory of the Common Practice Period (~1650-1900) is centered around the repertoire of male composers that have been celebrated throughout the annals of Music Theory. The works of prominent male composers of the eighteenth and nineteenth centuries including W.A. Mozart (1756-1791), J.S. Bach (1685-1750), L. Beethoven (1770-1827), F. Schubert (1797-1828), and G. Verdi (1813-1901), would directly influence instruction and study of the stylistic periods. This fixation on such a small number of composers would serve as an instructional canon of examples of key concepts within undergraduate music theory spanning from the classical period to modern times, leaving little space to consider repertoire of women and BIPOC composers. Our research serves to broaden the Music Theory canon by identifying compositions from underrepresented groups of composers to expand repertoire used in undergraduate Music Theory and Aural Skills curriculum. This research explores a wide range of readily available music repertoire composed by women and BIPOC composers within the KSU library and online music databases such as The International Music Score Library Project (IMSLP). These resources have given an opportunity to explore and assess a wider range of compositions that align with undergraduate Aural Skills and Music Theory, giving the opportunity to advocate, foster, and promote a broadened spectrum of music theory repertoire. By including works from the composers identified in this research, students will be given the opportunity to broaden their exposure to a wider range of important and exciting music, thus expanding their repertoire for performance and personal enjoyment. Through sharing this rich diversity of repertoire, this research serves to expose music students and audiences alike to a fuller and more diverse range of composers within the Common Practice Period to help classical music shed its perceived image as an “elite” art form