Student outcomes from diverse undergraduate research experiences - findings from a multi-disciplinary study

Undergraduate research experiences (UREs) provide students with opportunities to engage in high impact experiential learning. UREs have been especially prevalent in the sciences, but there are now extensive banks of case studies demonstrating the use of UREs as an educationally enriching activity in nearly all disciplines. This study investigated the diversity of UREs available across a wide range of disciplines at a large Australian research-intensive university and examined the perceived benefits. Through group interviews with 68 academics, we gathered detailed information about 81 URE activities, across 28 Schools within the institution (representing 77.8% of Schools), ranging from archaeology to political science, from biology to social work and from law to journalism. The most common URE model observed was that of activities embedded in courses. Across disciplines the most common feature was the requirement for students to engage with the research literature in their field. A smaller number of models incorporated features which allowed students to engage in other high impact learning activities such as community-based activities and internships. Although we identified a large ‘set’ of perceived student outcomes across the varied URE models the generic graduate attributes attained by students through these UREs appeared to be independent of the discipline itself. In most cases, the UREs were available to all students rather than an elite or specialist cohort. This leads us to believe that across a range of disciplinary contexts, there are many ways to use UREs to achieve high levels of engagement of large cohorts of students

Screening of winery and olive mill wastes for lignocellulolytic enzyme production from Aspergillus species by solid-state fermentation

Wastes from olive oil and wine industries (as exhausted grape marc, vineshoot trimmings, two-phase olive mill waste, vinasses, and olive mill wastewater) were evaluated for lignocellulolytic enzyme production (as endocellulases, endoxylanases, and feruloyl esterases) by solid-state fermentation (SSF) with Aspergillus niger, Aspergillus ibericus, and Aspergillus uvarum. To study the effect of different solid medium composition and time in enzyme production, a PlackettBurman experimental design was used. Variables that had a higher positive effect in lignocellulolytic enzyme production were urea, time, and exhausted grape marc. The maximum values of enzymatic activity per unit of substrate dry mass were found with A. niger for feruloyl esterase. Enzymatic extracts from SSF with A. niger achieved maximum feruloyl esterase activity (89.53 U/g) and endoxylanase activity (3.06 U/g) and with A. uvarum for endocellulase activity (6.77 U/g). The enzyme cocktails obtained in the SSF extracts may have applications in biorefinery industries.Jose Manuel Salgado is grateful for the postdoctoral fellowship (EX-2010-0402) of the Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, Portugal

A set of vertically integrated inquiry-based practical curricula that develop scientific thinking skills for large cohorts of undergraduate students

Science graduates require critical thinking skills to deal with the complex problems they will face in their 21st century workplaces. Inquiry-based curricula can provide students with the opportunities to develop such critical thinking skills; however, evidence suggests that an inappropriate level of autonomy provided to underprepared students may not only be daunting to students but also detrimental to their learning. After a major review of the Bachelor of Science, we developed, implemented, and evaluated a series of three vertically integrated courses with inquiry-style laboratory practicals for early-stage undergraduate students in biomedical science. These practical curricula were designed so that students would work with increasing autonomy and ownership of their research projects to develop increasingly advanced scientific thinking and communication skills. Students undertaking the first iteration of these three vertically integrated courses reported learning gains in course content as well as skills in scientific writing, hypothesis construction, experimental design, data analysis, and interpreting results. Students also demonstrated increasing skills in both hypothesis formulation and communication of findings as a result of participating in the inquiry-based curricula and completing the associated practical assessment tasks. Here, we report the specific aspects of the curricula that students reported as having the greatest impact on their learning and the particular elements of hypothesis formulation and communication of findings that were more challenging for students to master. These findings provide important implications for science educators concerned with designing curricula to promote scientific thinking and communication skills alongside content acquisition

Student understanding of the critical features of an hypothesis: variation across epistemic and heuristic dimensions

The higher education sector is now focussed on the task of creating graduates who are able to deal with the novel, complex, unstructured problems they will encounter in the 21st century workforce (Brew, 2010). Within science, the central role of hypothetico-deductive reasoning in ‘thinking like a scientist’ is well established (Dunbar and Fugelsang, 2005), and in bioscience education, understanding ‘testable hypotheses’ has become a threshold concept (Taylor and Meyer, 2010) and a key driver of curriculum transformation (Elliot et al., 2010). From a large database of responses provided by undergraduate biology students to the question “What is a hypothesis?” Taylor et al. (2011) developed a forty seven item psychometric instrument capturing variation in student understanding of this threshold concept. A version of this instrument has now been trialled with eight hundred undergraduate science students enrolled in a first year, second semester biology course. Exploratory factor analysis of their responses has revealed five factors which vary along dimensions of epistemic maturity and understanding of disciplinary heuristics. These factors are interpreted as representing the initial 'critical features' of the threshold concept as it 'comes into view'. Specifically, students were found to conceptualise hypotheses most simplistically as based on facts, or hold more advanced conceptions about the predictive utility of hypotheses (indicating an awareness of hypothetico-predictive reasoning) and to hypotheses as testable statements (indicating an awareness of hypothetico-deductive reasoning) used in the development of new scientific knowledge. Further, student conceptions varied on the role of observations, experiments and controlling variables in judging the validity of hypotheses. This snapshot characterises the conceptions about hypothesis held by early stage undergraduate science students, providing insights into the ways students are beginning to understand the heuristics used to judge the evidence that builds scientific knowledge in their discipline, as they embark on the journey toward thinking like a scientist

Fabrication and modeling of high-efficiency front junction n-type silicon solar cells with tunnel oxide passivating back contact

This paper reports on in-depth understanding, modeling, and fabrication of 23.8% efficient 4 cm2 n-type Float Zone (FZ) silicon cells with a selective boron emitter and photolithography contact on front and tunnel oxide passivating contact on the back. Tunnel oxide passivating contact composed of a very thin chemically grown silicon oxide (∼15 Å) capped with plasma-enhanced chemical vapor deposition (PECVD) grown 20 nm n+ poly Si gave excellent surface passivation and carrier selectivity with very low saturation current density (∼5 fA/cm2). A high-quality boron selective emitter was formed using ion implantation and solid source diffusion to minimize metal recombination and emitter saturation current density. Process optimization resulted in a cell Voc of 712 mV, Jsc of 41.2 mA/cm2, and FF of 0.811. A simple methodology is used to model these cells which replaces tunnel oxide passivating contact region by electron and hole recombination velocities extracted from measured saturation current density of tunnel oxide passivating contact region and analysis. Using this approach and two-dimensional device modeling gave an excellent match between the measured and simulated cell parameters and efficiency, supporting excellent passivation and carrier selectivity of these contacts. Extended simulations showed that 26% cell efficiency can be achieved with this cell structure by further optimization of wafer quality, emitter profile, and contact design