25 research outputs found
Black Girls Speak STEM: Counterstories of Informal and Formal Learning Experiences
This study presents the interpretations and perceptions of Black girls who participated in I AM STEM â a community-based informal science, technology, engineering, and mathematics (STEM) program. Using narrative inquiry, participants generated detailed accounts of their informal and formal STEM learning experiences. Critical race methodology informed this research to portray the dynamic and complex experiences of girls of color, whose stories have historically been silenced and misrepresented. The data sources for this qualitative study included individual interviews, student reflection journals, samples of student work, and researcher memos, which were triangulated to produce six robust counterstories. Excerpts of the counterstories are presented in this article. The major findings of this research revealed that I AM STEM ignited an interest in STEM learning through field trips and direct engagement in scientific phenomena that allowed the girls to become agentic in continuing their engagement in STEM activities throughout the year. This call to awaken the voices of Black girls to speak casts light on their experiences and challenges as STEM learners ⯠from their perspectives. The findings confirm that when credence and counterspaces are given to Black girls, they are poised to reveal their luster toward STEM learning. This study provided a space for Black girls to reflect on their STEM learning experiences, formulate new understandings, and make connections between the informal and formal learning environments within the context of their everyday lives, thus offering a more holistic approach to STEM learning that occurs across settings and over a lifetime
Treatment of periodontal intrabony defects using autologous periodontal ligament stem cells: a randomized clinical trial
Buckling analysis of planar linear uniform deployable structures consisting of scissor-like element in space under compression
Comparative clinical responses related to the use of various periodontal instrumentation.
AIM: The aim of this study was to evaluate in vivo the effectiveness of scaling and root planing of a power-driven mechanism compared with hand instruments and ultrasonic insert alone with a split-mouth design after 3 and 6 months. METHODS: Healing events after initial periodontal therapy were investigated in 20 patients with moderate-to-severe adult periodontitis. Plaque index (PlI), bleeding on probing (PBI), probing pocket depth (PPD), probing attachment level (PAL) and number of moderate and deep pockets (NMP, NDP) were recorded at baseline and 3 and 6 months after treatment. Oral hygiene instruction was provided for each patient. Randomly assigned quadrants per patient were scaled and root planed with hand instrumentation (curettes, hoes and files), with reciprocating power-driven instruments, with ultrasonic scaler alone and with the combined use of ultrasonic scaler and power-driven inserts. The Friedman test was applied to test the significance of difference between the various methods of root instrumentation. Repeated measures of analysis of variance (manova) were used to analyse the time effect on the different treatments. RESULTS: At the 6-month evaluation, all groups in the scaling and root planing treatment presented with an improvement in the measured clinical parameters, as compared with baseline. No statistical differences (p>0.05) were observed in the assessed periodontal indices among the study sites between the four groups for either treatment. CONCLUSIONS: Under our experimental conditions, this clinical study demonstrates that mechanized root planing with power-driven instruments, as effective as the usual procedures (hand and sonic instruments), represents a satisfactory and alternative means of nonsurgical root therapy