362 research outputs found

    Student Engagement in an Online Engineering Afterschool Program During the COVID-19 Pandemic

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    The COVID-19 pandemic forced much of schooling online and limited studentsā€™ access to informal learning opportunities such as afterschool programs. The purpose of this study was to investigate how fourth- and fifth-grade students engaged in an online engineering program and what factors influenced their engagement. We drew on a four-dimensional model of student engagement to describe how students engaged in the afterschool engineering program and to identify the factors that enhanced or inhibited engagement. Using a case study design, we drew on interviews with six program mentors and ten students and observation data from weekly Zoom sessions throughout the 2020ā€“2021 school year. We found examples of all four dimensions of engagement, but also of disengagement. The program influenced student engagement in multiple ways, including through the program mentorsā€™ social, pedagogical, and managerial roles, studentsā€™ interest in and enjoyment of engineering, the drawbacks and benefits of the online learning environment and Zoomā€™s affordances, and the nature of the programā€™s activities. We connect these factors to the different dimensions of engagement. We conclude with a discussion of how our findings add to research on engineering education in informal online settings and offer implications for practitioners

    Enhancing Engineering Identity Among Boys of Color

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    Black and Brown men continue to be underrepresented in engineering. One explanation for the dearth of Black and Latino men in engineering is that engineering (and STEM) identity often is not inclusive of People of Color. As a result, Black and Brown boys may be less likely to become interested in STEM subjects. The purpose of this study, then, was to investigate how the components of one afterschool engineering program tap into engineering identity formation among fourth- and fifth-grade Black and Brown boys. Leveraging research on the STEM and engineering identity, we argue that the program and its key components play both constructive and protective roles. This study comprises a case study of an afterschool engineering program completing its third year of implementation at three elementary schools. Over four semesters, we recruited approximately 60 students from the three schools and 21 mentors to participate in the study. We collected data via one-on-one interviews, focus groups, and observations. We found that engineering design activities are constructive, offering the young Black and Brown boys opportunities to engage with the work of engineers. The mentors played constructive roles by recognizing the studentsā€™ engineering work. The mentors also played a protective role, buffering against identity interference and cultivating a sense of belonging. We conclude by discussing how the findings contribute to existing research on engineering identity and making recommendations for practice

    Highly Variable Cycle Exhaust Model Test (HVC10)

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    Results from acoustic and flow-field studies using the Highly Variable Cycle Exhaust (HVC) model were presented. The model consisted of a lobed mixer on the core stream, an elliptic nozzle on the fan stream, and an ejector. For baseline comparisons, the fan nozzle was replaced with a round nozzle and the ejector doors were removed from the model. Acoustic studies showed far-field noise levels were higher for the HVC model with the ejector than for the baseline configuration. Results from Particle Image Velocimetry (PIV) studies indicated that large flow separation regions occurred along the ejector doors, thus restricting flow through the ejector. Phased array measurements showed noise sources located near the ejector doors for operating conditions where tones were present in the acoustic spectra

    Australian Public and Smallpox

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    A national survey of 1,001 Australians found that most were concerned about a bioterrorist attack and were ill-informed about smallpox prevention and response. Since general practitioners were commonly identified as the initial point of care, they should become a focus of bioterrorism response planning in Australia

    Cell bank characterization and fermentation optimization for production of recombinant heavy chain C-terminal fragment of botulinum neurotoxin serotype E (rBoNTE(H\u3csub\u3ec\u3c/sub\u3e): Antigen E) by \u3ci\u3ePichia pastoris\u3c/i\u3e

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    A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(Hc)in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(Hc) gene inserted into pHILD4 Escherichia coliā€”P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(Hc) sequence. Expression of rBoNTE(Hc) from the Mut+ HIS4 clone was conļ¬rmed in the shake-ļ¬‚ask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(Hc). Speciļ¬c growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(Hc) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(Hc) per gram wet cell mass as determined by HPLC and Western blot analysis

    Cell bank characterization and fermentation optimization for production of recombinant heavy chain C-terminal fragment of botulinum neurotoxin serotype E (rBoNTE(H\u3csub\u3ec\u3c/sub\u3e): Antigen E) by \u3ci\u3ePichia pastoris\u3c/i\u3e

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    A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(Hc)in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(Hc) gene inserted into pHILD4 Escherichia coliā€”P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(Hc) sequence. Expression of rBoNTE(Hc) from the Mut+ HIS4 clone was conļ¬rmed in the shake-ļ¬‚ask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(Hc). Speciļ¬c growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(Hc) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(Hc) per gram wet cell mass as determined by HPLC and Western blot analysis

    Biallelic Loss-of-Function Variants in BICD1 Are Associated with Peripheral Neuropathy and Hearing Loss

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    Hearing loss and peripheral neuropathy are two clinical entities that are genetically and phenotypically heterogeneous and sometimes co-occurring. Using exome sequencing and targeted segregation analysis, we investigated the genetic etiology of peripheral neuropathy and hearing loss in a large Ashkenazi Jewish family. Moreover, we assessed the production of the candidate protein via western blotting of lysates from fibroblasts from an affected individual and an unaffected control. Pathogenic variants in known disease genes associated with hearing loss and peripheral neuropathy were excluded. A homozygous frameshift variant in the BICD1 gene, c.1683dup (p.(Arg562Thrfs*18)), was identified in the proband and segregated with hearing loss and peripheral neuropathy in the family. The BIDC1 RNA analysis from patient fibroblasts showed a modest reduction in gene transcripts compared to the controls. In contrast, protein could not be detected in fibroblasts from a homozygous c.1683dup individual, whereas BICD1 was detected in an unaffected individual. Our findings indicate that bi-allelic loss-of-function variants in BICD1 are associated with hearing loss and peripheral neuropathy. Definitive evidence that bi-allelic loss-of-function variants in BICD1 cause peripheral neuropathy and hearing loss will require the identification of other families and individuals with similar variants with the same phenotype
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