128 research outputs found
Equitable Pre-College Engineering Education: Teaching with Racism in Mind
Engineering educators must consider how the cultural backgrounds of students coincide (or diverge) with the epistemological and ontological formation of an engineer. Hence, this work is presented as an exhortation to engineering educators, particularly in a pre-college context, to critically evaluate how race-conscious pedagogies can be exerted in this field. In this autoethnographic study, I convey my attempt to teach engineering with explicit consideration of the sociopolitical context of the Black male youth I taught. As a Black male, I have an insider perspective into the realities that must be navigated to succeed in a racialized society, where Black males are a demographic that has been mercilessly underserved and over-criminalized in the educational system. I discovered three themes that describe my approach to actualizing culturally relevant pedagogy in pre-college engineering education, which are (i) exhibiting political clarity in curriculum design and implementation, (ii) using students’ lived experiences as authentic contexts for teaching engineering, and (iii) building relationships with students, their families, and community so that we know the students we are teaching
Call for Papers: A Special Issue of the Journal of Pre-College Engineering Education Research on ‘‘Provocations’’
This special issue on Provocations aims to propel scholarly discourse in pre-college engineering education with thought-provoking papers. Without provocation we risk haphazardly designing research studies, courses, and curricula that can hinder transformation or veneer what is critical. We expect the special issue will foster an epistemological dissonance while insisting the field of pre-college engineering education redefine its purpose, assumptions, and values
Fostering Higher Academic Performance in African American Youth Through Enhanced Self-Efficacy: The Importance of Integrated Racial-Ethnic Identity
Although the dimensions that constitute racial-ethnic identity (REI) interrelate to affect psychosocial and academic outcomes, few studies have explored the nature (e.g., directionality) of these interrelations in understanding a strong and healthy REI among African American youth in relation to psychosocial and academic outcomes. In the current study, we applied path analysis to investigate the potential mediation effects of private regard in translating the effects of racial centrality and public regard to affect African American youth’s academic performance through self-efficacy. Using a nationally representative sample of African American youth, findings suggest that racial centrality and public regard correlate to affect private regard, controlling for neighborhood safety and sociodemographic backgrounds. Private regard in turn, associated with self-efficacy to affect academic performance measured by GPA. These results indicate the need to investigate the potential mediation effects among REI dimensions to understand the nuanced pathways REI dimensions configure to form a strong and healthy REI to affect psychosocial and academic outcomes among African American youth
Enhancing Engineering Identity Among Boys of Color
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 students’ 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
A proposed mechanism for nitrogen acquisition by grass seedlings through oxidation of symbiotic bacteria
In this paper we propose and provide evidence for a mechanism, oxidative nitrogen scavenging (ONS), whereby seedlings of some grass species may extract nitrogen from symbiotic diazotrophic bacteria through oxidation by plant-secreted reactive oxygen species (ROS). Experiments on this proposed mechanism employ tall fescue (Festuca arundinaceae) seedlings to elucidate features of the oxidative mechanism. We employed 15N2 gas assimilation experiments to demonstrate nitrogen fixation, direct microscopic visualization of bacteria on seedling surfaces to visualize the bacterial oxidation process, reactive oxygen probes to test for the presence of H2O2 and cultural experiments to assess conditions under which H2O2 is secreted by seedlings. We also made surveys of the seedlings of several grass species to assess the distribution of the phenomenon of microbial oxidation in the Poaceae. Key elements of the proposed mechanism for nitrogen acquisition in seedlings include: 1) diazotrophic bacteria are vectored on or within seeds; 2) at seed germination bacteria colonize seedling roots and shoots; 3) seedling tissues secrete ROS onto bacteria; 4) bacterial cell walls, membranes, nucleic acids, proteins and other biological molecules are oxidized; 5) nitrates and/or smaller fragments of organic nitrogen-containing molecules resulting from oxidation may be absorbed by seedling tissues and larger peptide fragments may be further processed by secreted or cell wall plant proteases until they are small enough for transport into cells. Hydrogen peroxide secretion from seedling roots and bacterial oxidation was observed in several species in subfamily Pooideae where seeds possessed adherent paleas and lemmas, but was not seen in grasses that lacked this feature or long-cultivated crop species
Horse-Related Injuries: Causes, Preventability, and Where Educational Efforts Should be Focused
A high percentage of equestrians will experience accidents, with different degrees of severity, throughout their riding careers. Horse-related injuries have the highest likelihood of requiring hospitalization based on individuals visiting US emergency departments. Studies have shown that the majority of injured riders said they could have prevented the accident and the injury was due to rider/handler error. Therefore, equestrians reported their injuries, and a panel of experts analyzed these reports to better understand the causes, how to prevent, and where to invest educational resources to generate a reduction in horse-related accidents. The majority of riders reported intermediate riding skills, most accidents occurred in the arena, and most were preventable. The most severe accidents occurred when the weather played a major role, as opposed to the least severe accidents when riders were in the horse’s space. Avoidable accidents included when tack broke, as opposed to unavoidable accidents such as horses slipped or fell. Educational Impact Index was calculated with combined results of the cause of injury, avoidability, and severity. Other humans, horse spooked, and tack/equipment problems were the main causes of accidents with the highest educational impact index, and authors believe that educational efforts should be focused on these categories
Viral Adaptation to an Antiviral Protein Enhances the Fitness Level to Above That of the Uninhibited Wild Type
Viruses often evolve resistance to antiviral agents. While resistant strains are able to replicate in the presence of the agent, they generally exhibit lower fitness than the wild-type strain in the absence of the inhibitor. In some cases, resistant strains become dependent on the antiviral agent. However, the agent rarely, if ever, elevates dependent strain fitness above the uninhibited wild-type level. This would require an adaptive mechanism to convert the antiviral agent into a beneficial growth factor. Using an inhibitory scaffolding protein that specifically blocks X174 capsid assembly, we demonstrate that such mechanisms are possible. To obtain the quintuple-mutant resistant strain, the wild-type virus was propagated for approximately 150 viral life cycles in the presence of increasing concentrations of the inhibitory protein. The expression of the inhibitory protein elevated the strain's fitness significantly above the uninhibited wild-type level. Thus, selecting for resistance coselected for dependency, which was characterized and found to operate on the level of capsid nucleation. To the best of our knowledge, this is the first report of a virus evolving a mechanism to productively utilize an antiviral agent to stimulate its fitness above the uninhibited wild-type level. The results of this study may be predictive of the types of resistant phenotypes that could be selected by antiviral agents that specifically target capsid assembly. While viruses often acquire resistance to antiviral agents, resistance mutants generally exhibit lower fitness than the wildtype strain in the absence of the inhibitor Due to its rapid replication, bacteriophage X174 has become an attractive model system for evolutionary studies The inhibitory proteins most likely remove assembly intermediates by lowering the thermodynamic barriers that normally prevent off-pathway reactions (4, 5). Both off-pathway reactions and proper assembly involve D-D protein interactions across what will become the twofold axes of symmetry in the virion (8, 9). In the procapsid crystal structure, ␣-helix 3 of the D 2 , D 3 , and D 4 subunits mediates these interactions. Mutants resistant to the dominant lethal proteins were isolated in one-step genetic selections, and mutations mapped to either the coat or internal scaffolding proteins. These mutations may indirectly reinstate the avidity of the D protein electrostatic bonding partners required for productive morphogenesis (4, 5). However, the resistance phenotype is weak. To isolate a more robust phenotype, wild-type X174 was continually cultured through exponential phase cells expressing an inhibitory D protein. Results from this analysis indicate that the selection for resistance coselected for a level of dependence. The inhibitory protein stimulates resistant strain fitness significantly above the uninhibited wild-type level and appears to be required for efficient capsid nucleation. These results suggest that the virus evolved a mechanism to convert this potent antiviral agent into a beneficial factor and may be predictive of the types of resistant phenotypes that could be selected by antiviral agents that specifically target capsid assembly
Downregulation of a UDP-Arabinomutase Gene in Switchgrass (Panicum virgatum L.) Results in Increased Cell Wall Lignin While Reducing Arabinose-Glycans
Background: Switchgrass (Panicum virgatum L.) is a C4 perennial prairie grass and a dedicated feedstock for lignocellulosic biofuels. Saccharification and biofuel yields are inhibited by the plant cell wall’s natural recalcitrance against enzymatic degradation. Plant hemicellulose polysaccharides such as arabinoxylans structurally support and cross-link other cell wall polymers. Grasses predominately have Type II cell walls that are abundant in arabinoxylan, which comprise nearly 25% of aboveground biomass. A primary component of arabinoxylan synthesis is uridine diphosphate (UDP) linked to arabinofuranose (Araf). A family of UDP-arabinopyranose mutase (UAM)/reversible glycosylated polypeptides catalyze the interconversion between UDP-arabinopyranose (UDP-Arap) and UDP-Araf.
Results: The expression of a switchgrass arabinoxylan biosynthesis pathway gene, PvUAM1, was decreased via RNAi to investigate its role in cell wall recalcitrance in the feedstock. PvUAM1 encodes a switchgrass homolog of UDP-arabinose mutase, which converts UDP-Arap to UDP-Araf. Southern blot analysis revealed each transgenic line contained between one to at least seven T-DNA insertions, resulting in some cases, a 95% reduction of native PvUAM1 transcript in stem internodes. Transgenic plants had increased pigmentation in vascular tissues at nodes, but were otherwise similar in morphology to the non-transgenic control. Cell wall-associated arabinose was decreased in leaves and stems by over 50%, but there was an increase in cellulose. In addition, there was a commensurate change in arabinose side chain extension. Cell wall lignin composition was altered with a concurrent increase in lignin content and transcript abundance of lignin biosynthetic genes in mature tillers. Enzymatic saccharification efficiency was unchanged in the transgenic plants relative to the control.
Conclusion: Plants with attenuated PvUAM1 transcript had increased cellulose and lignin in cell walls. A decrease in cell wall-associated arabinose was expected, which was likely caused by fewer Araf residues in the arabinoxylan. The decrease in arabinoxylan may cause a compensation response to maintain cell wall integrity by increasing cellulose and lignin biosynthesis. In cases in which increased lignin is desired, e.g., feedstocks for carbon fiber production, downregulated UAM1 coupled with altered expression of other arabinoxylan biosynthesis genes might result in even higher production of lignin in biomass
From St. Petersburg to Krushchev\u27s Boot
Program for the first annual RISD Cabaret held in Memorial Hall. Design and layout by Justin Kerr.https://digitalcommons.risd.edu/liberalarts_cabaret_programs/1000/thumbnail.jp
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